Science.gov

Sample records for absolute soft x-ray

  1. Absolute calibration of a soft X-ray spectrograph for X-ray laser research using white beam.

    PubMed

    Fujikawa, C; Kawachi, T; Ando, K; Yamaguchi, N; Hara, T

    1998-05-01

    Absolute calibration of a soft X-ray spectrograph has been performed using a white beam of synchrotron radiation. The calibrated spectrograph was a flat-field grazing-incidence spectrograph with an X-ray CCD detector for X-ray laser research. Absolute sensitivity of the spectrograph system can be obtained from transmitted spectra using filters made of several different materials, each providing an absorption-edge wavelength standard. The absolute sensitivity determined in this work shows nearly the same behaviour with wavelength as that in another calibration experiment using a laser-produced plasma as an X-ray source.

  2. A new method to calibrate the absolute sensitivity of a soft X-ray streak camera

    NASA Astrophysics Data System (ADS)

    Yu, Jian; Liu, Shenye; Li, Jin; Yang, Zhiwen; Chen, Ming; Guo, Luting; Yao, Li; Xiao, Shali

    2016-12-01

    In this paper, we introduce a new method to calibrate the absolute sensitivity of a soft X-ray streak camera (SXRSC). The calibrations are done in the static mode by using a small laser-produced X-ray source. A calibrated X-ray CCD is used as a secondary standard detector to monitor the X-ray source intensity. In addition, two sets of holographic flat-field grating spectrometers are chosen as the spectral discrimination systems of the SXRSC and the X-ray CCD. The absolute sensitivity of the SXRSC is obtained by comparing the signal counts of the SXRSC to the output counts of the X-ray CCD. Results show that the calibrated spectrum covers the range from 200 eV to 1040 eV. The change of the absolute sensitivity in the vicinity of the K-edge of the carbon can also be clearly seen. The experimental values agree with the calculated values to within 29% error. Compared with previous calibration methods, the proposed method has several advantages: a wide spectral range, high accuracy, and simple data processing. Our calibration results can be used to make quantitative X-ray flux measurements in laser fusion research.

  3. 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

    2014-09-08

    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.

  4. Absolute, soft x-ray calorimetry on the Z facility at Sandia National Laboratories

    SciTech Connect

    Fehl, D.L.; Muron, D.J.; Leeper, R.J.; Chandler, G.A.; Deeney, C.; Spielman, R.B.

    1998-05-01

    Simple and reliable x-ray fluence measurements, in addition to time-resolved diagnostics, are needed to understand the physics of hot Z-pinch plasmas. A commercially available laser calorimeter has been modified for measuring soft x-ray fluence from the Z facility at Sandia National Laboratories. The x-ray absorber of this calorimeter is an aluminum disk, attached to a two-dimensional thermopile and surrounded by an isoperibol shroud. The time-integral and the maximum of the thermopile voltage signal are both proportional to the x-ray energy deposited. Data are collected for 90 seconds, and the instrument has, thus far, been used in the 1--25 mJ range. A wider dynamic measuring range for x-ray fluence (energy/area) can be achieved by varying the area of the defining aperture. The calorimeter is calibrated by an electrical substitution method. Calibrations are performed before and after each x-ray experiment on the Z facility. The calibration of the time-integral of the thermopile voltage vs. energy deposited (or the peak of thermopile voltage vs. energy deposited) is linear with zero offset at the 95% confidence level. The irreproducibility of the calibration is <2%, and the imprecision in the measurement of the incident x-ray energy (inferred from signal noise and the calibration) is estimated to be {approximately}0.9 mJ (95% confidence level). The inaccuracy is estimated at {+-}10%, due to correctable systematic errors (e.g., baseline shifts). Comparisons have been made of the calorimeter to time-resolved x-ray diagnostics, e.g., bolometers and XRD (x-ray diode) arrays, by integrating the flux measured by these instruments over time.

  5. Absolute spectral characterization of silicon barrier diode: Application to soft X-ray fusion diagnostics at Tore Supra

    NASA Astrophysics Data System (ADS)

    Vezinet, D.; Mazon, D.; Malard, P.

    2013-07-01

    This paper presents an experimental protocol for absolute calibration of photo-detectors. Spectral characterization is achieved by a methodology that unlike the usual line emissions-based method, hinges on the Bremsstrahlung radiation of a Soft X-Ray (SXR) tube only. Although the proposed methodology can be applied virtually to any detector, the application presented in this paper is based on Tore Supra's SXR diagnostics, which uses Silicon Surface Barrier Diodes. The spectral response of these n-p junctions had previously been estimated on a purely empirical basis. This time, a series of second-order effects, like the spatial distribution of the source radiated power or multi-channel analyser non linearity, are taken into account to achieve accurate measurements. Consequently, a parameterised physical model is fitted to experimental results and the existence of an unexpected dead layer (at least 5 μm thick) is evidenced. This contribution also echoes a more general on-going effort in favour of long-term quality of passive radiation measurements on Tokamaks.

  6. 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.

  7. 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.

  8. Silicon Absolute X-Ray Detectors

    SciTech Connect

    Seely, John F.; Korde, Raj; Sprunck, Jacob; Medjoubi, Kadda; Hustache, Stephanie

    2010-06-23

    The responsivity of silicon photodiodes having no loss in the entrance window, measured using synchrotron radiation in the 1.75 to 60 keV range, was compared to the responsivity calculated using the silicon thickness measured using near-infrared light. The measured and calculated responsivities agree with an average difference of 1.3%. This enables their use as absolute x-ray detectors.

  9. 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.

  10. Absolute radiant power measurement for the Au M lines of laser-plasma using a calibrated broadband soft X-ray spectrometer with flat-spectral response.

    PubMed

    Troussel, Ph; Villette, B; Emprin, B; Oudot, G; Tassin, V; Bridou, F; Delmotte, F; Krumrey, M

    2014-01-01

    CEA implemented an absolutely calibrated broadband soft X-ray spectrometer called DMX on the Omega laser facility at the Laboratory for Laser Energetics (LLE) in 1999 to measure radiant power and spectral distribution of the radiation of the Au plasma. The DMX spectrometer is composed of 20 channels covering the spectral range from 50 eV to 20 keV. The channels for energies below 1.5 keV combine a mirror and a filter with a coaxial photo-emissive detector. For the channels above 5 keV the photoemissive detector is replaced by a conductive detector. The intermediate energy channels (1.5 keV < photon energy < 5 keV) use only a filter and a coaxial detector. A further improvement of DMX consists in flat-response X-ray channels for a precise absolute measurement of the photon flux in the photon energy range from 0.1 keV to 6 keV. Such channels are equipped with a filter, a Multilayer Mirror (MLM), and a coaxial detector. We present as an example the development of channel for the gold M emission lines in the photon energy range from 2 keV to 4 keV which has been successfully used on the OMEGA laser facility. The results of the radiant power measurements with the new MLM channel and with the usual channel composed of a thin titanium filter and a coaxial detector (without mirror) are compared. All elements of the channel have been calibrated in the laboratory of the Physikalisch-Technische Bundesanstalt, Germany's National Metrology Institute, at the synchrotron radiation facility BESSY II in Berlin using dedicated well established and validated methods.

  11. Absolute radiant power measurement for the Au M lines of laser-plasma using a calibrated broadband soft X-ray spectrometer with flat-spectral response

    SciTech Connect

    Troussel, Ph.; Villette, B.; Oudot, G.; Tassin, V.; Bridou, F.; Delmotte, F.; Krumrey, M.

    2014-01-15

    CEA implemented an absolutely calibrated broadband soft X-ray spectrometer called DMX on the Omega laser facility at the Laboratory for Laser Energetics (LLE) in 1999 to measure radiant power and spectral distribution of the radiation of the Au plasma. The DMX spectrometer is composed of 20 channels covering the spectral range from 50 eV to 20 keV. The channels for energies below 1.5 keV combine a mirror and a filter with a coaxial photo-emissive detector. For the channels above 5 keV the photoemissive detector is replaced by a conductive detector. The intermediate energy channels (1.5 keV < photon energy < 5 keV) use only a filter and a coaxial detector. A further improvement of DMX consists in flat-response X-ray channels for a precise absolute measurement of the photon flux in the photon energy range from 0.1 keV to 6 keV. Such channels are equipped with a filter, a Multilayer Mirror (MLM), and a coaxial detector. We present as an example the development of channel for the gold M emission lines in the photon energy range from 2 keV to 4 keV which has been successfully used on the OMEGA laser facility. The results of the radiant power measurements with the new MLM channel and with the usual channel composed of a thin titanium filter and a coaxial detector (without mirror) are compared. All elements of the channel have been calibrated in the laboratory of the Physikalisch-Technische Bundesanstalt, Germany's National Metrology Institute, at the synchrotron radiation facility BESSY II in Berlin using dedicated well established and validated methods.

  12. Absolute radiant power measurement for the Au M lines of laser-plasma using a calibrated broadband soft X-ray spectrometer with flat-spectral response

    NASA Astrophysics Data System (ADS)

    Troussel, Ph.; Villette, B.; Emprin, B.; Oudot, G.; Tassin, V.; Bridou, F.; Delmotte, F.; Krumrey, M.

    2014-01-01

    CEA implemented an absolutely calibrated broadband soft X-ray spectrometer called DMX on the Omega laser facility at the Laboratory for Laser Energetics (LLE) in 1999 to measure radiant power and spectral distribution of the radiation of the Au plasma. The DMX spectrometer is composed of 20 channels covering the spectral range from 50 eV to 20 keV. The channels for energies below 1.5 keV combine a mirror and a filter with a coaxial photo-emissive detector. For the channels above 5 keV the photoemissive detector is replaced by a conductive detector. The intermediate energy channels (1.5 keV < photon energy < 5 keV) use only a filter and a coaxial detector. A further improvement of DMX consists in flat-response X-ray channels for a precise absolute measurement of the photon flux in the photon energy range from 0.1 keV to 6 keV. Such channels are equipped with a filter, a Multilayer Mirror (MLM), and a coaxial detector. We present as an example the development of channel for the gold M emission lines in the photon energy range from 2 keV to 4 keV which has been successfully used on the OMEGA laser facility. The results of the radiant power measurements with the new MLM channel and with the usual channel composed of a thin titanium filter and a coaxial detector (without mirror) are compared. All elements of the channel have been calibrated in the laboratory of the Physikalisch-Technische Bundesanstalt, Germany's National Metrology Institute, at the synchrotron radiation facility BESSY II in Berlin using dedicated well established and validated methods.

  13. 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.

  14. 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.

  15. ALFT's Soft X-Ray Source Development

    NASA Astrophysics Data System (ADS)

    Panarella, Emilio

    2002-11-01

    ALFT (www.alft.com) was funded by the Federal and Provincial governments of Canada in 1987 to pursue the objective of making soft X-ray sources for microlithography.For 15 years ALFT has successfully pursued this objective. Recently, the company has found that its sources can complement the synchrotron as provider of soft X-rays for applications that range from biotechnology to nanotechnology.A beam from the Canadian Synchrotron (CLS) will deliver 10^13 photons/sec in a collimated output, whereas the weakest of ALFT's sources delivers an average of 10^15 photons/sec, two orders of magnitude higher than the synchrotron, albeit in the 4 pi direction. The most powerful of ALFT's sources delivers pulses carrying an average of 10^16 photons/sec, with peak flux of 10^24 photons/sec, again in the 4 pi.The proprietary technology of ALFT rests not only on the electron bombardment concept of X-ray production but also, by using a special plasma (the Vacuum Spark), on the pinch phenomenon, thus obtaining better efficiency than conventional sources. By discharging a simple condenser in a very low inductance circuit, a metallic plasma is generated in a vacuum vessel between two electrodes, where plasma pinch and micropinch phenomena raise the plasma temperature and density to values that lead to large soft X-ray production.The talk will present an overview of the VSX soft X-ray source development, examining first the physics of the vacuum spark, then the extendibility to higher power outputs, and then to the engineering issues that have been solved leading to the first product, the VSX 400, a machine that delivers 400 mW of soft X-rays, and to the VSX Z10, a prototype machine that delivers 10 W of X-rays.The recent visits to the CLS and follow-up discussions that are leading towards the placement of one VSX 400 machine in Saskatoon will also reported.

  16. 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.

  17. 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.

  18. 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.

  19. Soft X-Ray Laser Development

    DTIC Science & Technology

    1989-10-01

    AND SUBTrI 5 . FUNDING NUMBERS Soft X-ray Laser Development 61102F/2301/A8 L AUTHOR(S) ( Szymon Suckewer 7. PERFORMING ORGANIZATION NAME(S) AND ADORESS...diDr-uinteg~uior Slack 5 . Funding Numbers. To include contract a-d5( fcanTehil and grant numtners; may include programn Reports. element number(s...g~m x 5 mm line-focus on a length-varying cylindrical target. The target lengths used in this experiment were 1, 2.5, and 4.5 mm ( limited by the

  20. Diagnostics for an XUV/soft x-ray laser

    SciTech Connect

    Kauffman, R.L.; Matthews, D.L.; Ceglio, N.; Medecki, H.

    1984-03-03

    We have begun investigating the production of an XUV/soft x-ray laser, using our high-powered glass lasers as drivers. A major diagnostic for lasing is the measure of the absolute power produced in the lasing line. I have developed a spectrograph to time-resolved lasing lines in the energy range from 50 eV to greater than 200 eV. the spectrograph combines a transmission grating and x-ray streak camera to produce a flat field instrument. A cylindrical mirror is used in front of the grating to image the source and act as a collecting optic. The efficiency of the components is calibrated so that absolute intensities can be measured. I will compare the performance of this instrument with reflection grating systems. I will also discuss planned improvements to the system which should increase total throughput, image quality, and resolving power.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Burning DT Plasmas with Ultrafast Soft X-Ray Pulses

    NASA Astrophysics Data System (ADS)

    Hu, S. X.; Goncharov, V. N.; Skupsky, S.

    2012-10-01

    Fast ignition with narrowband, coherent ultrafast soft x-ray pulsesfootnotetextS. X. Hu, V. N. Goncharov, and S. Skupsky, ``Burning Plasmas with Ultrashort Soft-X-Ray Flashing,'' to be published in Physics of Plasmas. has been investigated for cryogenic deuterium--tritium (DT) plasma conditions achieved on the OMEGA Laser System. In contrast to using hard x-rays (hν = 3 to 6 keV) proposed in the original x-ray fast-ignition proposal, we find that soft x-ray sources with hν 500-eV photons can be more suitable for igniting the dense DT plasmas. Two-dimensional radiation--hydrodynamics simulations have identified the breakeven conditions for realizing such a ``hybrid'' ignition scheme (direct-drive compression with soft x-ray heating) with 50-μm-offset targets: an ˜10-ps soft x-ray pulse (hν 500 eV) with a total energy of 500 to 1000 J to be focused into a 10-μm spot size. A variety of x-ray pulse parameters have also been investigated for optimization. It is noted that an order of magnitude increase in neutron yield has been predicted even with x-ray energy as low as ˜50 J. Scaling this idea to a 1-MJ large-scale NIF target, a gain above ˜30 can be reached with the same soft x-ray pulse at 1.65-kJ energy. Even though such energetic x-ray sources do not currently exist, we hope that the proposed ignition scheme may stimulate efforts on generating powerful soft x-ray sources in future. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

  8. 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.

  9. 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.

  10. 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.

  11. Burning plasmas with ultrashort soft-x-ray flashing

    NASA Astrophysics Data System (ADS)

    Hu, S. X.; Goncharov, V. N.; Skupsky, S.

    2012-07-01

    Fast ignition with narrow-band coherent x-ray pulses has been revisited for cryogenic deuterium-tritium (DT) plasma conditions achieved on the OMEGA Laser System. In contrast to using hard-x-rays (hv = 3-6 keV) proposed in the original x-ray fast-ignition proposal, we find that soft-x-ray sources with hv ≈ 500 eV photons can be suitable for igniting the dense DT-plasmas achieved on OMEGA. Two-dimensional radiation-hydrodynamics simulations have identified the break-even conditions for realizing such a "hybrid" ignition scheme (direct-drive compression with soft-x-ray heating) with 50-μm-offset targets: ˜10 ps soft-x-ray pulse (hv ≈ 500 eV) with a total energy of 500-1000 J to be focused into a 10 μm spot-size. A variety of x-ray pulse parameters have also been investigated for optimization. It is noted that an order of magnitude increase in neutron yield has been predicted even with x-ray energy as low as ˜50 J. Scaling this idea to a 1 MJ large-scale target, a gain above ˜30 can be reached with the same soft-x-ray pulse at 1.65 kJ energy. Even though such energetic x-ray sources do not currently exist, we hope that the proposed ignition scheme may stimulate efforts on generating powerful soft-x-ray sources in the near future.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Ionic photofragmentation and photoionization of dimethyl ether in the VUV and soft X-ray regions (8.5 80 eV) absolute oscillator strengths for molecular and dissociative photoionization

    NASA Astrophysics Data System (ADS)

    Feng, Renfei; Cooper, Glyn; Brion, C. E.

    2001-08-01

    The branching ratios for molecular and dissociative photoionization of dimethyl ether (CH 3OCH 3, DME) have been measured in the VUV and soft X-ray regions using dipole (e,e+ion) coincidence spectroscopy (˜1 eV FWHM) at equivalent photon energies from the first ionization threshold up to 80 eV. The absolute partial oscillator strengths (cross-sections) for molecular and dissociative photoionization have been determined from recently published absolute photoabsorption oscillator strength data [R. Feng, G. Cooper, C.E. Brion, Chem. Phys. 260 (2000) 391] together with the photoionization branching ratios and the (multi-dissociative-corrected) photoionization efficiency obtained from time-of-flight mass spectra reported in the present work. No stable multiply charged molecular ion(s) from DME have been found in the present work. However, the fact that the photoionization efficiency has been measured as greater than unity above ˜30 eV indicates the existence of multi-dissociative products from Coulomb explosion of multiply charged ions. Appearance potentials of all ion products from DME are also reported. The presently reported results are compared with the previously published data where possible.

  18. Soft x-ray holographic microscopy

    SciTech Connect

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

    2010-01-25

    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.

  19. Divergence measurements of soft x-ray laser beam

    SciTech Connect

    Suckewer, S.; Skinner, C.H.; Kim, D.; Valeo, E.; Voorhees, D.; Wouters, A.

    1986-07-01

    The divergence of the CVI 182 A lasing line generated in a rapidly recombining, magnetically confined plasma column was measured using soft x-ray spectrometers equipped with multichannel detectors. In addition to measurements of the relative divergence, an absolute divergence of approx.9 mrad at a magnetic field of 20 kG and approx.5 mrad at a magnetic field of 35 or 50 kG was obtained by a direct scan of the 182 A axial radiation. Based on this data a peak 182 A intensity of approx.100 kW is obtained. Calculations of the spatial distribution of gain in the plasma were in very good agreement with the experimental data.

  20. 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.

  1. 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.

  2. 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.

  3. Temperature dependent soft x-ray absorption spectroscopy of liquids.

    PubMed

    Meibohm, Jan; Schreck, Simon; Wernet, Philippe

    2014-10-01

    A novel sample holder is introduced which allows for temperature dependent soft x-ray absorption spectroscopy of liquids in transmission mode. The setup is based on sample cells with x-ray transmissive silicon nitride windows. A cooling circuit allows for temperature regulation of the sample liquid between -10 °C and +50 °C. The setup enables to record soft x-ray absorption spectra of liquids in transmission mode with a temperature resolution of 0.5 K and better. Reliability and reproducibility of the spectra are demonstrated by investigating the characteristic temperature-induced changes in the oxygen K-edge x-ray absorption spectrum of liquid water. These are compared to the corresponding changes in the oxygen K-edge spectra from x-ray Raman scattering.

  4. 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.

  5. Observations of X-ray jets with the Yohkoh Soft X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Shibata, Kazunari; Ishido, Yoshinori; Acton, Loren W.; Strong, Keith T.; Hirayama, Tadashi; Uchida, Yutaka; Mcallister, Alan H.; Matsumoto, Ryoji; Tsuneta, Saku; Shimizu, Toshifumi

    1992-01-01

    The features of the multiple X-ray jets in the solar corona, revealed by the time series of the Yohkoh Soft X-ray Telescope images are described. The typical size of a jet was from 5 x 10 exp 3 to 4 x 10 exp 5 km, the translational velocity was 30-300 km/s, and the corresponding kinetic energy was estimated to be from 10 exp 25 to 10 exp 28 erg. Many of the jets were found to be associated with flares in X-ray bright points, emerging flux regions, or active regions, and they sometimes occurred several times from the same X-ray feature. One of the jets associated with a flaring bright point was identified as being an H-alpha surge.

  6. Soft-x-ray fragmentation studies of molecular ions

    NASA Astrophysics Data System (ADS)

    Wolf, Andreas; Pedersen, Henrik B.; Lammich, Lutz; Jordon-Thaden, Brandon; Altevogt, Simon; Domesle, Christian; Hergenhahn, Uwe; Förstel, Marko; Heber, Oded

    2010-10-01

    Imaging of photofragments from molecular ions after irradiation by soft x-ray photons has been realized at the ion beam infrastructure TIFF set up at the FLASH facility. Photodissociation of the two-electron system HeH+ at 38.7 eV revealed the electronic excitations and the charge-state ratios for the products of this process, reflecting the non-adiabatic dissociation dynamics through multiple avoided crossings among the HeH+ Rydberg potential curves. Dissociative ionization of the protonated water molecules H3O+ and H5O+2 at 90 eV revealed the main fragmentation pathways after the production of valence vacancies in these ionic species, which include a strong three-body channel with a neutral fragment (OH + H+ + H+) in H3O+ photolysis and a significant two-body fragmentation channel (H3O++ H2O+) in H5O+2 photolysis. The measurements yield absolute cross sections and fragment angular distributions. Increased precision and sensitivity of the technique were realized in recent developments, creating a tool for exploring x-ray excited molecular states under highly controlled target conditions challenging detailed theoretical understanding.

  7. 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.

  8. 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.

  9. Soft x-ray transmission grating spectrometer for X-ray Surveyor and smaller missions with high resolving power

    NASA Astrophysics Data System (ADS)

    Heilmann, Ralf K.; Bruccoleri, Alexander; Schattenburg, Mark; Kolodziejczak, jeffery; Gaskin, Jessica; O'Dell, Stephen L.

    2017-01-01

    A number of high priority subjects in astrophysics are addressed by a state-of-the-art soft x-ray grating spectrometer, e.g. the role of Active Galactic Nuclei in galaxy and star formation, characterization of the WHIM and the “missing baryon” problem, characterization of halos around the Milky Way and nearby galaxies, and stellar coronae and surrounding winds and disks. An Explorer-scale, large-area (A > 1,000 cm2), high resolving power (R > 3,000) soft x-ray grating spectrometer is highly feasible based on Critical-Angle Transmission (CAT) grating technology, even for telescopes with angular resolution of 5-10 arcsec. Significantly higher performance could be provided by a CAT grating spectrometer on an X-ray-Surveyor-type mission (A > 4,000 cm2, R > 5,000). CAT gratings combine advantages of blazed reflection gratings (high efficiency, use of higher orders) with those of transmission gratings (low mass, relaxed alignment tolerances and temperature requirements, transparent at higher energies) with minimal mission resource requirements. Blazing is achieved through grazing-incidence reflection off the smooth silicon grating bar sidewalls. Silicon is well matched to the soft x-ray band, and 30% absolute diffraction efficiency has been acheived with clear paths for further improvement. CAT gratings with sidewalls made of high-Z elements allow extension of blazing to higher energies and larger dispersion angles, enabling higher resolving power at shorter wavelengths. X-ray data from CAT gratings coated with a thin layer of platinum using atomic layer deposition demonstrate efficient blazing to higher energies and much larger blaze angles than possible with silicon alone. Measurements of the resolving power of a breadboard CAT grating spectrometer consisting of a Wolter-I slumped-glass focusing optic from GSFC and CAT gratings, taken at the MSFC Stray Light Facility, have demonstrated resolving power > 10,000. Thus currently fabricated CAT gratings are compatible

  10. 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.

  11. Soft X-ray spectrographs for solar observations

    NASA Technical Reports Server (NTRS)

    Bruner, M. E.

    1988-01-01

    Recent advances in soft X-ray spectrometery are reviewed, with emphasis on techniques for studying the windowless region from roughly 1-100 A. Recent technological developments considered include multilayer mirrors, large-format CCD detectors which are sensitive to X-rays, position-sensitive photon counting detectors, new kinds of X-ray films, and optical systems based on gratings with nonuniform ruling spacings. Improvements in the extent and accuracy of the atomic physics data sets on which the analysis of spectroscopic observatons depend are also discussed.

  12. 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.

  13. 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.

  14. Picosecond resolution soft x-ray laser plasma interferometry

    SciTech Connect

    Moon, S; Nilsen, J; Ng, A; Shlyaptsev, V; Dunn, J; Hunter, J; Keenan, R; Marconi, M; Filevich, J; Rocca, J; Smith, R

    2003-12-01

    We describe a soft x-ray laser interferometry technique that allows two-dimensional diagnosis of plasma electron density with picosecond time resolution. It consists of the combination of a robust high throughput amplitude division interferometer and a 14.7 nm transient inversion soft x-ray laser that produces {approx} 5 ps pulses. Due to its picosecond resolution and short wavelength scalability, this technique has potential for extending the high inherent precision of soft x-ray laser interferometry to the study of very dense plasmas of significant fundamental and practical interest, such as those investigated for inertial confined fusion. Results of its use in the diagnostics of dense large scale laser-created plasmas are presented.

  15. 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.

  16. 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

  17. Optical systems for synchrotron radiation: lecture 4. Soft x-ray imaging systems

    SciTech Connect

    Howells, M.R.

    1986-04-01

    The history and present techniques of soft x-ray imaging are reviewed briefly. The physics of x-ray imaging is described, including the temporal and spatial coherence of x-ray sources. Particular technologies described are: contact x-ray microscopy, zone plate imaging, scanned image zone plate microscopy, scanned image reflection microscopy, and soft x-ray holography and diffraction. (LEW)

  18. Fast fluctuations of soft X-rays from active regions

    NASA Technical Reports Server (NTRS)

    Simnett, G. F.; Dennis, B. R.

    1986-01-01

    A selection of short lived small soft X-ray bursts is studied using data from the Hard X-ray Imaging Spectrometer (HXIS), and the results are compared with the data from the Hard X-Ray Burst Spectrometer (HXRBS) with a view to understanding conditions at the onset of flares. Short-lived events provide an opportunity to study the radiation from the primary energy transfer process without confusion from the slowly-varying thermal X-ray emission which characterizes the decay of a large flare. The fast decay of the soft X-rays, only a few tens of seconds, suggests that they occur in the dense chromosphere. The results indicate that the short events may be signatures of several different phenomena, depending on their characteristics. Some events occur in association with reverse-drift type III bursts and simultaneous flaring elsewhere on the Sun, thus suggesting dumping of particles accelerated at a remote site. Some events have hard X-ray bursts and normal type III bursts associated with them, while others have neither. The latter events place strong constraints on the nonthermal electron population present.

  19. [Development of soft X-ray and vacuum ultraviolet spectrum sources].

    PubMed

    Chen, Bo; Ni, Qi-liang; Cao, Jian-lin; Li, Fu-tian; Chen, Xing-dan

    2005-03-01

    The soft X-ray and vacuum ultraviolet sources developed in CIOMP are presented. The wall-stabilized argon arc source with spectrum stability and repeatability of +/-0.3% is applied to the calibration of spectrum intensity distribution of the vacuum ultraviolet instruments as an absolute standard source. The Penning source, duobplasma source and hollow cathode source are able to produce atomic and ionic line spectra as a wavelength standard source, which covers a few nanometers to several tens nanometers with spectrum radiation stability and repeatability of +/-1.0%. In particular, the low debris laser produced plasma source with liquid aerosol spray target recently developed can emit stronger soft X-ray for soft X-ray lithography and metrology, which has a transfer efficiency as high as 0.75%/2pi x sr/2% bandwidth.

  20. Soft X ray properties of the Geminga pulsar

    NASA Astrophysics Data System (ADS)

    Halpern, J. P.; Ruderman, M.

    1993-01-01

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

  1. Soft X-ray techniques to study mesoscale magnetism

    SciTech Connect

    Kortright, Jeffrey B.

    2003-06-26

    Heterogeneity in magnetization (M) is ubiquitous in modern systems. Even in nominally homogeneous materials, domains or pinning centers typically mediate magnetization reversal. Fundamental lengths determining M structure include the domain wall width and the exchange stiffness length, typically in the 4-400 nm range. Chemical heterogeneity (phase separation, polycrystalline microstructure, lithographic or other patterning, etc.) with length scales from nanometers to microns is often introduced to influence magnetic properties. With 1-2 nm wavelengths {lambda}, soft x-rays in principle can resolve structure down to {lambda}/2, and are well suited to study these mesoscopic length scales [1, 2]. This article highlights recent advances in resonant soft x-ray methods to resolve lateral magnetic structure [3], and discusses some of their relative merits and limitations. Only techniques detecting x-ray photons (rather than photo-electrons) are considered [4], since they are compatible with strong applied fields to probe relatively deeply into samples. The magneto-optical (MO) effects discovered by Faraday and Kerr were observed in the x-ray range over a century later, first at ''hard'' wavelengths in diffraction experiments probing interatomic magnetic structure [5]. In the soft x-ray range, magnetic linear [6] and circular [7] dichroism spectroscopies first developed that average over lateral magnetic structure. These large resonant MO effects enable different approaches to study magnetic structure or heterogeneity that can be categorized as microscopy or scattering [1]. Direct images of magnetic structure result from photo-emission electron microscopes [4, 8] and zone-plate microscopes [9, 10]. Scattering techniques extended into the soft x-ray include familiar specular reflection that laterally averages over structure but can provide depth-resolved information, and diffuse scattering and diffraction that provide direct information about lateral magnetic structure

  2. 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.

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

    DOE PAGES

    Turner, Joshua J.; Nelson, Johanna; Huang, Xiaojing; ...

    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.

  4. 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.

  5. 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.

  6. The Solar-A soft X-ray telescope experiment

    NASA Technical Reports Server (NTRS)

    Acton, L.; Bruner, M.; Brown, W.; Lemen, J.; Hirayama, T.

    1988-01-01

    The Japanese Solar-A mission for the study of high energy solar physics is timed to observe the sun during the next activity maximum. This small spacecraft includes a carefully coordinated complement of instruments for flare studies. In particular, the soft X-ray telescope (SXT) will provide X-ray images of flares with higher sensitivity and time resolution than have been available before. This paper describes the scientific capabilities of the SXT and illustrates its application to the study of an impulsive compact flare.

  7. A Feasibility Experiment for a Soft X-Ray Laser

    DTIC Science & Technology

    1976-09-01

    AFWL-TR-76-107 ( )FWL-TR- 76-107 A FEASIBILITY EXPERIMENT FOR A SOFT X-RAY LASER September 1976 Final Report Approved for public release...Introduction 29 The Utah Experiment 29 Other Hard X-ray Laser Considerations 29 V SUMMARY Conclusions 31 A4CEUI@N lV Future Directions 31 IT4 whie... Experimental Chamber 23 4 Sketch of Vacuum Chamber 24 ii AFWL-TR-76-107 SECTION I INTRODUCTION 1. SYNOPSIS The purpose of this report is to present an

  8. 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.

  9. In situ soft X-ray absorption spectroscopy of flames

    NASA Astrophysics Data System (ADS)

    Frank, Jonathan H.; Shavorskiy, Andrey; Bluhm, Hendrik; Coriton, Bruno; Huang, Erxiong; Osborn, David L.

    2014-10-01

    The feasibility of in situ soft X-ray absorption spectroscopy for imaging carbonaceous species in hydrocarbon flames is demonstrated using synchrotron radiation. Soft X-rays are absorbed by core level electrons in all carbon atoms regardless of their molecular structure. Core electron spectroscopy affords distinct advantages over valence spectroscopy, which forms the basis of traditional laser diagnostic techniques for combustion. In core level spectroscopy, the transition linewidths are predominantly determined by the instrument response function and the decay time of the core-hole, which is on the order of a femtosecond. As a result, soft X-ray absorption measurements can be performed in flames with negligible Doppler and collisional broadening. Core level spectroscopy has the further advantage of measuring all carbonaceous species regardless of molecular structure in the far-edge region, whereas near-edge features are molecule specific. Interferences from non-carbon flame species are unstructured and can be subtracted. In the present study, absorption measurements in the carbon K-edge region are demonstrated in low-pressure ( P total = 20-30 Torr) methane jet flames. Two-dimensional imaging of the major carbonaceous species, CH4, CO2, and CO, is accomplished by tuning the synchrotron radiation to the respective carbon K-edge, near-edge X-ray absorption fine structure (NEXAFS) transitions and scanning the burner.

  10. 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.

  11. 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.

  12. Actinide science with soft x-ray synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Shuh, David K.

    2000-07-01

    The primary methods for the experimental investigation of actinide materials in the VUV/soft x-ray region are the complementary photoelectron spectroscopies, near-edge x-ray absorption fine structure (NEXAFS), and x-ray emission spectroscopy (XES) techniques. Resonant photoemission techniques capable of resolving the 5f electron contributions to actinide bonding along with angle-resolving measurements for band structure and surface structure determinations, have clear and immediate applications. Venerable angle-integrating core and valence band photoelectron spectroscopy are valuable for characterization and analytical purposes. Combined with results from NEXAFS measurements, these techniques will provide the information needed to develop improved understandings of the electronic structure of actinide materials and their surface chemistries/physics.

  13. 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

  14. Non-periodic multilayer coatings in EUV, soft x-ray and x-ray range

    NASA Astrophysics Data System (ADS)

    Wang, Zhanshan

    2008-09-01

    Non-periodic multilayer coatings offer engineer great flexibility to achieve tailored spectral performance in EUV, soft X-ray and X-ray region. We have developed a variety of non-periodic multilayer mirrors for use as optical key components for polarization-sensitive studies, Kirkpatrick-Baez microscope, Earth's magnetosphere observation and reflection of sub-femtosecond pulses. To find optimal distribution of layer thicknesses for a given spectral response, several numerical algorithms, such as simplex, simulated annealing, genetic and Levenberg Marquardt, have been explored to solve the reverse optimization problems. The designed non-periodic multilayers were prepared by use of a direct current magnetron sputtering system and characterized by grazing incidence x-ray reflectometry analysis. The synchrotron measurements of these samples were performed at the National Synchrotron Radiation Laboratory, China and at the beamline UE56/1-PGM-1 at BESSY II Berlin, Germany. This paper covers our recent results of design and fabrication of non-periodic multilayer coatings. And the mirror performance and limitations were also briefly reviewed.

  15. Ignitron-driven soft flash x-ray generator

    NASA Astrophysics Data System (ADS)

    Sagae, Michiaki; Sato, Eiichi; Ichimaru, Toshio; Obara, Haruo; Sakamaki, Kimio; Takayama, Kazuyoshi; Tamakawa, Yoshiharu

    1997-12-01

    The fundamental study on a soft flash x-ray generator utilizing an ignitron is described. This generator consists of the following essential components: a high-voltage power supply, a high-voltage pulser having an ignitron, an oil diffusion pump, and a flash x-ray tube. The x-ray tube employs a molybdenum anode rod, a pipe-shaped carbon cathode, a polymethylmeth acrylate tube body, and a polyethylene terephthalate x-ray window. The space between the anode and the cathode electrodes (ac space) can be controlled by rotating the anode rod. The high-voltage condenser in the pulser is charged from 40 to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube by the ignitron through a 2.0 m coaxial cable. Because the maximum anode voltage of the ignitron is 50 kV, a free-air gap switch is employed in order to increase the high-voltage durability. In the present work, the anode electrode is connected to the ground, and the negative high-voltage output is applied to the cathode electrode. The flash x-rays are then produced. The peak cathode voltage and tube current had values of minus 56 kV and 11.5 kA, respectively, with a charging voltage of 60 kV and an ac space of 6.0 mm, and the pulse widths were less than 300 ns.

  16. 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.

  17. 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.

  18. The Effect of X-Ray Absorption Fine Structure in Soft X-ray Astronomical Telescopes

    NASA Astrophysics Data System (ADS)

    Owens, Alan; Denby, Michael; Wells, Alan; Keay, Adam; Graessle, Dale E.; Blake, Richard L.

    1997-02-01

    Recent in-orbit measurements by high resolution soft X-ray telescopes have revealed low-level fine structure in target spectra that cannot be attributed to a celestial source. Ultimately, this can be traced to the ability of the new high spectral resolution silicon detectors to resolve X-ray absorption fine structure (XAFS) produced in the various detection subsystems. Based on measurements taken at the Daresbury Synchrotron Radiation Source (SRS) and the National Synchrotron Light Source (NSLS), we have modeled the full-up response function of the Joint European X-ray Telescope (JET-X), taking into account edge structure generated in the detectors, filters, and mirrors. It is found that unfolding celestial source spectra using a response function in which the detailed edge shapes are calculated from standard absorption cross sections leads to the generation of spectral artifacts at every absorption edge. These in turn produce unacceptably high values of χ2 in model fits for total source fluxes above ~4 × 104 counts. For JET-X, this corresponds to a source strength of ~0.4 millicrab observed for 105 s. Statistically significant ``linelike'' features are introduced into the derived source spectra with amplitudes as great as 10% of the source flux. For JET-X, these features rise above the 3 σ level for integral source exposures above ~5 × 104 source counts. The largest deviations in the residuals arise near 0.5 keV and 2.2 keV and are attributed to XAFS produced in the oxide surface layers of the CCD and the gold reflective surface of the mirrors, respectively. These results are significant for data interpretation tasks with the ASCA, JET-X, XMM, and Advanced X-Ray Astrophysics Facility (AXAF) telescopes.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. [Soft X-ray reflectometer with laser produced plasma source].

    PubMed

    Chen, Bo; Ni, Qi-liang; Cao, Ji-hong

    2005-03-01

    A soft X-ray reflectometor with laser-produced plasma source developed in the authorial lab is presented for the measurements of efficiencies of gratings, transmission of filter and reflectance of multilayer coatings. The reflectometer is composed of a soft X-ray laser-produced plasma source, a grazing incidence monochromator with a constant deviation angle, a vacuum chamber, a sample table, a photo-electronic unit and a computer controlling unit. The working wavelength is from 8 to 30 nm and the maximum sample size is 130 mm long by 120 mm wide by 120 mm high. In order to test the performances of the reflectometer, the reflectivity of multilayer coatings was obtained by using this device. The measured results agree well with the theoretical calculation. The reproducibility of measured reflectance is +/-0.6%.

  4. Solar EUV, XUV and soft X-ray telescope facilities

    NASA Technical Reports Server (NTRS)

    Withbroe, G. L.

    1982-01-01

    Facility class, high resolution instrumentation can enable maximum spatial, spectral and temporal resolutions and provide understanding of the complex physical conditions in the outer solar atmosphere and the mechanisms responsible for these conditions. The scientific rationale for facility class instruments operating in the EUV, XUV, and soft X ray spectral ranges are discussed. Possible configurations for these facilities and priorities for their development are considered.

  5. 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

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

    SciTech Connect

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

    2016-01-28

    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.

  7. 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.

  8. 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.

  9. 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

  10. Soft x-ray measurements from the PDX tokamak

    SciTech Connect

    Silver, E.H.; Bitter, M.; Brau, K.; Eames, D.; Greenberger, A.; Hill, K.W.; Meade, D.M.; Roney, W.; Sauthoff, N.R.; von Goeler, S.

    1982-05-01

    Temporally and spatially-resolved profiles of the PDX soft x-ray spectra have been measured during single tokamak pulses of circular and divertor plasmas with a recently developed pulse height analyzer. This detection system incorporates an array of five vertically displaced sets of lithium-drifted silicon detectors, each consisting of three independent channels optimized for rapid data collection in adjacent energy regions. Simultaneous measurement of x-ray emission integrated along five chords of the plasma cross section can thereby be achieved. Abel inversion of these data yields temporally-resolved radial profiles of the local electron temperature from the slope of the continuum, concentrations of high-Z impurities from the characteristic line intensities, and a measure of Z/sub eff/ from the continuum intensity. The techniques of x-ray pulse height analysis, with illustrations featuring the results from the initial PDX circular plasma experiments are discussed in detail. In addition, comparisons between circular and divertor plasmas on PDX, derived from the x-ray measurements, are also presented.

  11. 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.

  12. Absolute X-ray emission cross section measurements of Fe K transitions

    NASA Astrophysics Data System (ADS)

    Hell, Natalie; Brown, Gregory V.; Beiersdorfer, Peter; Boyce, Kevin R.; Grinberg, Victoria; Kelley, Richard L.; Kilbourne, Caroline; Leutenegger, Maurice A.; Porter, Frederick Scott; Wilms, Jörn

    2016-06-01

    We have measured the absolute X-ray emission cross sections of K-shell transitions in highly charged L- and K-shell Fe ions using the LLNL EBIT-I electron beam ion trap and the NASA GSFC EBIT Calorimeter Spectrometer (ECS). The cross sections are determined by using the ECS to simultaneously record the spectrum of the bound-bound K-shell transitions and the emission from radiative recombination from trapped Fe ions. The measured spectrum is then brought to an absolute scale by normalizing the measured flux in the radiative recombination features to their theoretical cross sections, which are well known. Once the spectrum is brought to an absolute scale, the cross sections of the K-shell transitions are determined. These measurements are made possible by the ECS, which consists of a 32 channel array, with 14 channels optimized for detecting high energy photons (hν > 10 keV) and 18 channels optimized for detecting low energy photons (hν < 10 keV). The ECS has a large collection area, relatively high energy resolution, and a large bandpass; all properties necessary for this measurement technique to be successful. These data will be used to benchmark cross sections in the atomic reference data bases underlying the plasma modeling codes used to analyze astrophysical spectra, especially those measured by the Soft X-ray Spectrometer calorimeter instrument recently launched on the Hitomi X-ray Observatory.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, and supported by NASA grants to LLNL and NASA/GSFC and by ESA under contract No. 4000114313/15/NL/CB.

  13. 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.

  14. White-light spacial frequency multiplication using soft x rays

    NASA Astrophysics Data System (ADS)

    Wei, Max; Gullikson, Eric M.; Underwood, James H.; Gustafson, T. Kenneth; Attwood, David T., Jr.

    1995-09-01

    We have patterned a 0.25-micron period grating in SAL-601 photoresist using soft x-ray white-light spatial frequency multiplication. The configuration is that of a grating interferometer using two transmission gratings having the same period ((Lambda) equals 0.5 micron) and fabricated by electron beam lithography and lift-off. The first transmission grating splits an incoming x-ray beam into two paths and the second grating, operating in higher order, combines the two beams. A standing wave pattern is obtained at the intersection of the two beams and recorded by a photoresist coated substrate. This patterning technique has the advantage of multiplying the spatial frequency of the interferometer gratings by an even integer factor. Furthermore, the recording geometry is insensitive to both the longitudinal and transverse coherence of the illumination. Synchrotron bending magnet radiation from the advanced light source located at the Lawrence Berkeley National Laboratory was used as the source. The grating interferometer geometry has been used in the past to record white-light interference fringes using visible and ultraviolet light sources. We have used a two-grating interferometer to provide an initial demonstration of white-light spatial frequency doubling at soft x-ray wavelengths. By using this technique with shorter period parent gratings, it should be possible to patten gratings with higher resolution than electron beam lithography.

  15. 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).

  16. 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/.

  17. X-ray absorption and soft x-ray fluorescence analysis of KDP optics

    SciTech Connect

    Nelson, A J; van Buuren, T; Miller, E; Land, T A; Bostedt, C; Franco, N; Whitman, P K; Baisden, P A; Terminello, L J; Callcott, T A

    2000-08-09

    Potassium Dihydrogen Phosphate (KDP) is a non-linear optical material used for laser frequency conversion and optical switches. Unfortunately, when KDP crystals are coated with a porous silica anti-reflection coating [1] and then exposed to ambient humidity, they develop dissolution pits [2,3]. Previous investigations [2] have shown that thermal annealing renders KDP optics less susceptible to pitting suggesting that a modification of surface chemistry has occurred. X-ray absorption and fluorescence were used to characterize changes in the composition and structure of KDP optics as a function of process parameters. KDP native crystals were also analyzed to provide a standard basis for interpretation. Surface sensitive total electron yield and bulk sensitive fluorescence yield from the K 2p, P 2p (L{sub 2,3}-edge) and O 1s (K-edge) absorption edges were measured at each process step. Soft X-ray fluorescence was also used to observe changes associated with spectral differences noted in the absorption measurements. Results indicate that annealing at 160 C dehydrates the surface of KDP resulting in a metaphosphate surface composition with K:P:O = 1:1:3.

  18. 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.

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

    SciTech Connect

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

    2016-01-28

    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.

  20. 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.

  1. Soft x-ray spectroscopy of the Vela supernova remnant

    NASA Astrophysics Data System (ADS)

    Zeiger, Benjamin R.

    The CODEX sounding rocket payload was designed and flown to significantly improve spectral resolution of the Vela supernova remnant (SNR) in the soft x-ray (0.1--1.0 keV) bandpass. High spectral resolution (E/Delta E > 40) across its 3.25° x 3.25° field of view would disentangle thermal emission from nonthermal or line emission components to constrain the age when SNRs stop emitting nonthermal x-rays. Relatively recent observations have found significant nonthermal emission from remnants up to several kyr old, but CODEX encountered concurrent problems of higher noise and lower signal than expected, leaving the thermal versus nonthermal question unanswered in the 11 kyr-old Vela SNR. This thesis covers the motivation, design, and post-flight analysis of the CODEX instrument and data from its flight.

  2. Resonant soft X-ray diffraction - in extremis.

    PubMed

    Hatton, P D; Wilkins, S B; Beale, T A W; Johal, T K; Prabhakaran, D; Boothroyd, A T

    2005-07-01

    The use of softer-energy X-rays produced by synchrotron radiation for diffraction is an area of current interest. In this paper, experiments exploiting resonant scattering at the L absorption edges of 3d transition metal elements are reported. Such energies, typically 500-1000 eV, are at the extreme limit of soft X-ray diffraction where absorption effects are so severe that the sample and diffractometer must be placed in a windowless high-vacuum vessel. In addition, the Ewald sphere is so small as to likely contain, at most, only a single Bragg reflection. Advantages of using such radiation for the study of weak diffraction effects such as anomalous scattering, charge ordering, magnetic diffraction and orbital ordering are reported.

  3. 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.

  4. Soft x-ray emission from classical novae in outburst

    SciTech Connect

    Starrfield, S. Arizona State Univ., Tempe, AZ . Dept. of Physics and Astronomy); Truran, J.W. . Dept. of Astronomy); Sparks, W.M. ); Krautter, J. ); MacDonald, J. . Dept. of Physics and Ast

    1989-01-01

    Theoretical modeling of novae in outburst predicts that they should be active emitters of radiation at soft x-ray wavelengths twice during their outburst. The first time occurs very early in the outburst when only a very sensitive all sky survey will be able to detect them. This period lasts only a few hours for the very fastest novae. They again become bright in x-rays late in the outburst when the remnant object becomes very hot and is still luminous. Both simulations and observations show that novae can remain very hot for months to years. It is important to observe them at these late times because a measurement both of the flux and temperature can provide information about the mass of the white dwarf, the turn-off time scale, and the energy budget of the outburst. 8 refs., 2 figs.

  5. Soft X-ray photoemission studies of Hf oxidation

    SciTech Connect

    Suzer, S.; Sayan, S.; Banaszak Holl, M.M.; Garfunkel, E.; Hussain, Z.; Hamdan, N.M.

    2002-02-01

    Soft X-Ray Photoemission Spectroscopy using surface sensitive Synchrotron Radiation has been applied to accurately determine the binding energy shifts and the valence band offset of the HfO2 grown on Hf metal. Charging of oxide films under x-rays (or other irradiation) is circumvented by controlled and sequential in-situ oxidation. Photoemission results show the presence of metallic Hf (from the substrate) with the 4f7/2 binding energy of 14.22 eV, fully oxidized Hf (from HfO2) with the 4f7/2 binding energy of 18.16 eV, and at least one clear suboxide peak. The position of the valence band of HfO2 with respect to the Hf(m) Fermi level is determined as 4.05 eV.

  6. New Developments in Femtosecond Soft X-ray Spectroscopy

    SciTech Connect

    Erko, A.; Firsov, A.; Holldack, K.

    2010-06-23

    Recent instrumentation developments in X-ray spectroscopy for ultra-fast time-resolved measurements with soft X-rays done in HZB Berlin during the last years are described. The significant performance improvements achieved this way are based on Fresnel diffraction from structures being fabricated on a surface of a total externally reflecting mirror. The first type of this spectrometer, an off-axis reflection zone plate, has been implemented at the BESSY Femtoslicing setup and shows on the order of 20 times higher flux in the focal plane compared to the classical grating monochromator beamline. It has proven to serve very precise experiments with a time resolution down to 100 fs on magnetic materials after optical laser pulse excitation.

  7. 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.

  8. 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.

  9. Soft X-ray Charged Piezoelectret for Kinetic Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Lu, J.; Cho, HJ; Suzuki, Y.

    2016-11-01

    Piezoelectret polymer attracts much attention for its high piezoelectric coefficient. Multilayered piezoelectret structures are often charged with corona discharge, but it is difficult to get high surface charge density. To address this issue, a multilayered piezoelectret structure with embedded electrode is proposed, which can be efficiently poled with soft X-ray charging. With the aid of embedded electrodes, the bias voltage is directly applied to each unit cell, rather than divided and distributed to multiple layers. With an early PTFE-based prototype, output power of 0.5 μJ has been obtained for 0.3 mm displacement in 0.2 s.

  10. 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.

  11. 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.

  12. Soft x-ray microscope using Fourier transform holography

    SciTech Connect

    McNulty, I.; Kirz, J.; Jacobsen, C.; Anderson, E.; Howells, M.R.; Rarback, H. . Dept. of Physics; Lawrence Berkeley Lab., CA; Brookhaven National Lab., Upton, NY )

    1989-01-01

    A Fourier transform holographic microscope with an anticipated resolution of better than 100 nm has been built. Extensive testing of the apparatus has begun. Preliminary results include the recording of interference fringes using 3.6 nm x-rays. The microscope employs a charge-coupled device (CCD) detector array of 576 {times} 384 elements. The system is illuminated by soft x-rays from a high brightness undulator. The reference point source is formed by a Fresnel zone plate with a finest outer zone width of 50 nm. Sufficient temporal coherence for hologram formation is obtained by a spherical grating monochromator. The x-ray hologram intensities at the recording plane are to be collected, digitized and reconstructed by computer. Data acquisition is under CAMAC control, while image display and off-line processing takes place on a VAX graphics workstation. Computational models of Fourier transform hologram synthesis, and reconstruction in the presence of noise, have demonstrated the feasibility of numerical methods in two dimensions, and that three-dimensional information is potentially recoverable. 13 refs., 3 figs.

  13. Recent upgrades to MST's soft-x-ray spectroscopy diagnostic

    NASA Astrophysics Data System (ADS)

    Pandya, M. D.; Scherer, A. C.; Clark, J.; Dubois, A. M.; Almagri, A. F.; Chapman, B. E.

    2016-10-01

    In MST RFP plasmas, electron energization during tearing mode reconnection events was recently observed via soft-x-ray (sxr) emission. X-ray measurements from 3-25 keV during these short-lived (< 100 μs) events were achieved with a detector consisting of an avalanche photodiode and a 20 ns Gaussian shaping amplifier (GSA) whose output was digitized at 500 MHz. A radially resolved measurement of x-ray emission from 2-10 keV can also be made with an existing array of six Amptek XR-100CR sxr detectors, each comprised of a Si photodiode, a charge-sensitive preamplifier, a thermoelectric cooler, and a Cremat GSA CR-200-500ns having a pulse FWHM of about 1200 ns. One upgrade to this system entails a CR-200-25ns GSA which will reduce the FWHM to 60 ns. The digitization rate is also increased from 60 MHz to 240 MHz, sufficient to resolve a 60 ns Gaussian pulse. The upgrade will also incorporate improved shielding from IGBT switching noise arising from MST's Bt and Bp programmable power supplies. Housing the detector assembly within Compac-SRF-series enclosures attenuates noise at 20 MHz by 80 dB. Initial measurements will be presented. Work supported by US DOE.

  14. Suborbital Soft X-Ray Spectroscopy with Gaseous Electron Multipliers

    NASA Astrophysics Data System (ADS)

    Rogers, Thomas D.

    This thesis consists of the design, fabrication, and launch of a sounding rocket payload to observe the spectrum of the soft X-ray emission (0.1-1 keV) from the Cygnus Loop supernova remnant. This instrument, designated the Off-plane Grating Rocket for Extended Source Spectroscopy (OGRESS), was launched from White Sands Missile Range on May 2nd, 2015. The X-ray spectrograph incorporated a wire-grid focuser feeding an array of gratings in the extreme off-plane mount which dispersed the spectrum onto Gaseous Electron Multiplier (GEM) detectors. The gain characteristics of OGRESS's GEM detectors were fully characterized with respect to applied voltage and internal gas pressure, allowing operational settings to be optimized. The GEMs were optimized to operate below laboratory atmospheric pressure, allowing lower applied voltages, thus reducing the risk of both electrical arcing and tearing of the thin detector windows. The instrument recorded 388 seconds of data and found highly uniform count distributions over both detector faces, in sharp contrast to the expected thermal line spectrum. This signal is attributed to X-ray fluorescence lines generated inside the spectrograph. The radiation is produced when thermal ionospheric particles are accelerated into the interior walls of the spectrograph by the high voltages of the detector windows. A fluorescence model was found to fit the flight data better than modeled supernova spectra. Post-flight testing and analysis revealed that electrons produce distinct signal on the detectors which can also be successfully modeled as fluorescence emission.

  15. 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.

  16. Proton induced quasi-monochromatic x-ray beams for soft x-ray spectroscopy studies and selective x-ray fluorescence analysis

    SciTech Connect

    Sokaras, D.; Zarkadas, Ch.; Fliegauf, R.; Beckhoff, B.; Karydas, A. G.

    2012-12-15

    We present the analytical features and performance of an x-ray spectroscopy end station of moderate energy resolution operating with proton-induced quasi-monochromatic x-ray beams. The apparatus was designed, installed and operated at the 5.5 MV Tandem VdG Accelerator Laboratory of the Institute of Nuclear Physics, N.C.S.R. 'Demokritos,' Athens. The setup includes a two-level ultrahigh vacuum chamber that hosts in the lower level up to six primary targets in a rotatable holder; there, the irradiation of pure element materials-used as primary targets-with few-MeV high current ({approx}{mu}A) proton beams produces intense quasi-monochromatic x-ray beams of selectable energy. In the chamber's upper level, a six-position rotatable sample holder hosts the targets considered for x-ray spectroscopy studies. The proton-induced x-ray beam, after proper collimation, is guided to the sample position whereas various filters can be also inserted along the beam's path to eliminate the backscattered protons or/and to absorb selectively components of the x-ray beam. The apparatus incorporates an ultrathin window Si(Li) spectrometer (FWHM 136 eV at 5.89 keV) coupled with low-noise electronics capable of efficiently detecting photons down to carbon K{alpha}. Exemplary soft x-ray spectroscopy studies and results of selective x-ray fluorescence analysis are presented.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Soft X-Ray Pulsations in Solar Flares

    NASA Astrophysics Data System (ADS)

    Simões, P. J. A.; Hudson, H. S.; Fletcher, L.

    2015-12-01

    The soft X-ray emissions ( hν>1.5 keV) of solar flares mainly come from the bright coronal loops at the highest temperatures normally achieved in the flare process. Their ubiquity has led to their use as a standard measure of flare occurrence and energy, although the overwhelming bulk of the total flare energy goes elsewhere. Recently Dolla et al. ( Astrophys. J. Lett. 749, L16, 2012) noted quasi-periodic pulsations (QPP) in the soft X-ray signature of the X-class flare SOL2011-02-15, as observed by the standard photometric data from the GOES ( Geostationary Operational Environmental Satellite) spacecraft. In this article we analyse the suitability of the GOES data for this type of analysis and find them to be generally valuable after September, 2010 (GOES-15). We then extend the result of Dolla et al. to a complete list of X-class flares from Cycle 24 and show that most of them (80 %) display QPPs in the impulsive phase. The pulsations show up cleanly in both channels of the GOES data, making use of time-series of irradiance differences (the digital time derivative on the 2-s sampling). We deploy different techniques to characterise the periodicity of GOES pulsations, considering the red-noise properties of the flare signals, finding a range of characteristic time scales of the QPPs for each event, but usually with no strong signature of a single period dominating in the power spectrum. The QPP may also appear on somewhat longer time scales during the later gradual phase, possibly with a greater tendency towards coherence, but the sampling noise in GOES difference data for high irradiance values (X-class flares) makes these more uncertain. We show that there is minimal phase difference between the differenced GOES energy channels, or between them and the hard X-ray variations on short time scales. During the impulsive phase, the footpoints of the newly forming flare loops may also contribute to the observed soft X-ray variations.

  3. 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.

  4. Soft X-Ray Observations of a Complete Sample of X-Ray--selected BL Lacertae Objects: Erratum

    NASA Astrophysics Data System (ADS)

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

    1996-07-01

    In the paper, "Soft X-Ray Observations of a Complete Sample of X-Ray- selected BL Lacertae Objects" by Eric S. Perlman, John T. Stocke, Q. Daniel Wang, and Simon L. Morris (ApJ, 456,451 [1996]), there is an error in Figure 5 (see Section 4.1). The corrected figure is given below. The discussion in the text and the conclusions of the paper are unaffected by this error, which occurred during the publication process. See Journal.

  5. 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.

  6. High repetition rate laser produced soft x-ray source for ultrafast x-ray absorption near edge structure measurements.

    PubMed

    Fourmaux, S; Lecherbourg, L; Harmand, M; Servol, M; Kieffer, J C

    2007-11-01

    Recent progress in high intensity ultrafast laser systems provides the opportunity to produce laser plasma x-ray sources exhibiting broad spectrum and high average x-ray flux that are well adapted to x-ray absorption measurements. In this paper, the development of a laser based x-ray absorption near edge structure (XANES) beamline exhibiting high repetition rate by using the Advanced Laser Light Source (ALLS) facility 100 Hz laser system (100 mJ, 35 fs at 800 nm) is presented. This system is based on a broadband tantalum solid target soft x-ray source and a grazing incidence grating spectrometer in the 1-5 nm wavelength range. To demonstrate the high potential of this laser based XANES technique in condensed matter physics, material science, or biology, measurements realized with several samples are presented: VO2 vanadium L edge, Si3N4 nitrogen K edge, and BPDA/PPD polyimide carbon K edge. The characteristics of this laser based beamline are discussed in terms of brightness, signal to noise ratio, and compared to conventional synchrotron broadband x-ray sources which allow achieving similar measurements. Apart from the very compact size and the relative low cost, the main advantages of such a laser based soft x-ray source are the picosecond pulse duration and the perfect synchronization between this x-ray probe and a laser pulse excitation which open the way to the realization of time resolved x-ray absorption measurements with picosecond range time resolution to study the dynamics of ultrafast processes and phase transition.

  7. 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)

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Design and analysis of soft X-ray imaging microscopes

    NASA Technical Reports Server (NTRS)

    Shealy, David L.; Cheng, Wang; Wu, Jiang; Hoover, Richard B.

    1992-01-01

    The spherical Schwarzschild microscope for soft X-ray applications in microscopy and projection lithography consists of two concentric spherical mirrors configured such that the third-order spherical aberration and coma are zero. Since multilayers are used on the mirror substrates for X-ray applications, it is desirable to have only two reflecting surfaces in a microscope. To reduce microscope aberrations and increase the field of view, generalized mirror surface profiles are here considered. Based on incoherent and sine wave modulation transfer function calculations, the object plane resolution of a microscope has been analyzed as a function of the object height and numerical aperture (NA) of the primary for several spherical Schwarzschild, conic, and aspherical Head reflecting two-mirror microscope configurations. The Head microscope with a NA of 0.4 achieves diffraction limited performance for objects with a diameter of 40 microns. Thus, it seems possible to record images with a feature size less than 100 A with a 40x microscope when using 40 A radiation.

  13. Optical, UV and soft x-ray transmission of optical blocking layer for the x-ray CCD

    NASA Astrophysics Data System (ADS)

    Kawai, K.; Kohmura, T.; Ikeda, S.; Kaneko, K.; watanabe, T.; Tsunemi, H.; Hayashida, K.; Anabuki, N.; Nakajima, H.; Ueda, S.; Tsuru, T. G.; Dotani, T.; Ozaki, M.; Matsuta, K.; Fujinaga, T.; Kitamoto, S.; Murakami, H.; Hiraga, J.; Mori, K.; ASTRO-H SXI Team

    2012-03-01

    We have newly developed the back-illuminated (BI)-CCD which has an Optical Blocking Layer (OBL) directly coating its X-ray illumination surface with Aluminum-Polyimide-Aluminum instead of Optical Blocking Filter (OBF). OBL is composed of a thin polyimide layer sandwiched by two Al layers. Al and Polyimide has a capability to cut visible light and EUV, respectively. To evaluate the performance of OBL that cut off EUV as well as transmit soft X-ray, we measured the EUV and Soft X-ray transmission of both OBL at various energy range between 15-2000 eV by utilizing beam line located at the Photon Factory in High Energy Accelerator Research Organization. We obtained the EUV transmission to be ~3% at 41eV which is as same as expected transmission from the designed thickness of polyimide layer, and found no significant change of the EUV transmission of polyimide found during 9month. We also obtained the Soft X-ray transmission of OBL, and found the X-ray transmission of OBL was consistent with the result expected from the thickness of OBL. We also measured the Optical transmission of OBL between 500-900 nm to evaluate the performance of Al that cut off optical light, and obtained the optical transmission to be less than 4×10-5.

  14. 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.

  15. 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.

  16. The LNLS soft X-ray spectroscopy beamline.

    PubMed

    Tolentino, H; Compagnon-Cailhol, V; Vicentin, F C; Abbate, M

    1998-05-01

    The soft X-ray spectroscopy beamline installed at a bending-magnet source at the LNLS is described. The optics are designed to cover energies from 800 to 4000 eV with good efficiency. The focusing element is a gold-coated toroidal mirror with an angle of incidence of 17 mrad. The UHV double-crystal monochromator has three pairs of crystals, Si (111), InSb (111) and beryl (101;0), that can be selected by a sliding movement. The UHV workstation is equipped with an ion gun, an electron gun, an electron analyser, LEED optics, an open channeltron and a photodiode array. This beamline is intended for photoemission, photoabsorption, reflectivity and dichroism experiments.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

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

    SciTech Connect

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

    2010-06-23

    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.

  2. Soft X-rays from the Cygnus Loop: Interpretation.

    PubMed

    Tucker, W H

    1971-04-23

    Two possible interpretations of the recent soft x-ray observation of the Cygnus Loop are discussed. A synchrotron model requires a magnetic field less than 10(-6) gauss and electron energies in excess of 10(14) electron volts. These electrons must either have been reaccelerated or continuously injected into the source for about 50,000 years. The observations are also consistent with the radiation from a hot plasma having the cosmic abundances of the elements. A likely origin for the hot plasma is a blast wave produced by the explosion of a supernova in the interstellar medium. Fitting such a model to the observations implies a kinetic energy release in the explosion of 6x 10(50) ergs for an assumed distance of 770 parsec.

  3. 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.

  4. 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.

  5. Early Results from the YOHKOH Soft X-ray Telescope

    NASA Astrophysics Data System (ADS)

    Bruner, M. E.; Acton, L. W.; Lemen, J.; Hirayama, T.; Tsuneta, S.

    1992-05-01

    The The Soft X-ray Telescope on the Yohkoh satellite, launched by Japan on August 30, 1992, has proved to be a resounding success. It is providing a wealth of new information and many surprises, both on flares and on the behavior of the solar corona. Performance of the telescope has met or exceed our most optimistic expectations and it appears to be in perfect focus. Unlike the Skylab instruments, the Yohkoh telescope is not limited by a finite supply of film, permitting long sequences of images to be made with relatively high time resolution. Repetition rates for a given exposure / filter combination are typically a few seconds per frame to a few minutes per frame, depending on the selected field size. Movies assembled from long exposure sequences have shown the corona to be even more dynamic than expected. Major re-structuring, involving large fractions of the visible corona, can take place in an hour or two. Smaller regions are even more dynamic, changing almost continuously. Movies, created from long exposure sequences, have demonstrated the fundamental importance of large-scale coronal loops in connecting widely separated regions such that activity in one region quickly affects the physical conditions at remote sites. The images also show that the majority of the loops have nearly constant cross sections along their lengths, rather than one that increases with height. Several X-class flares have been observed; the surprising result is that they do not appear to be very dynamic in soft X-rays. The flare kernels seem to consist of compact loop structures that brighten and then fade without changing size or shape. Bright points are not as prominent as in the Skylab images; a result of using a CCD (a linear detector) rather than film which has a logarithmic response. The other instruments on Yohkoh are producing equally exciting results; it seems clear that the Yohkoh mission will produce many major advances in our knowledge of the flare mechanism.

  6. Rocket Experiment Demonstration of a Soft X-ray Polarimeter

    NASA Astrophysics Data System (ADS)

    Marshall, Herman

    This proposal is the lead proposal. Boston University will submit, via NSPIRES, a Co-I proposal, per instructions for Suborbital proposals for multiple-award. Our scientific goal of the Rocket Experiment Demonstration of a Soft X-ray Polarimeter (REDSoX Polarimeter) is to make the first measurement of the linear X-ray polarization of an extragalactic source in the 0.2-0.8 keV band. The first flight of the REDSoX Polarimeter would target Mk 421, which is commonly modeled as a highly relativistic jet aimed nearly along the line of sight. Such sources are likely to be polarized at a level of 30-60%, so the goal is to obtain a significant detection even if it is as low as 10%. Significant revisions to the models of jets emanating from black holes at the cores of active galaxies would be required if the polarization fraction lower than 10%. 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%. Using replicated foil mirrors from MSFC and gratings made at MIT, we construct a spectrometer that disperses to three laterally graded multilayer mirrors (LGMLs). The lateral grading changes the wavelength of the Bragg peak for 45 degree reflections linearly across the mirror, matching the dispersion of the spectrometer. By dividing the entrance aperture into six equal sectors, pairs of blazed gratings from opposite sectors are oriented to disperse to the same LGML. The position angles for the LGMLs are 120 degrees to each other. CCD detectors then measure the intensities of the dispersed spectra after reflection and polarizing by the LGMLs, giving the three Stokes parameters needed to determine the source polarization. We will rely on components whose performance has been verified in the laboratory or in space. The CCD detectors are based on Chandra and Suzaku heritage. The mirror fabrication team

  7. Energy dispersive X-ray analysis on an absolute scale in scanning transmission electron microscopy.

    PubMed

    Chen, Z; D'Alfonso, A J; Weyland, M; Taplin, D J; Allen, L J; Findlay, S D

    2015-10-01

    We demonstrate absolute scale agreement between the number of X-ray counts in energy dispersive X-ray spectroscopy using an atomic-scale coherent electron probe and first-principles simulations. Scan-averaged spectra were collected across a range of thicknesses with precisely determined and controlled microscope parameters. Ionization cross-sections were calculated using the quantum excitation of phonons model, incorporating dynamical (multiple) electron scattering, which is seen to be important even for very thin specimens.

  8. Layer-by-layer design method for soft-X-ray multilayers

    NASA Technical Reports Server (NTRS)

    Yamamoto, Masaki; Namioka, Takeshi

    1992-01-01

    A new design method effective for a nontransparent system has been developed for soft-X-ray multilayers with the aid of graphic representation of the complex amplitude reflectance in a Gaussian plane. The method provides an effective means of attaining the absolute maximum reflectance on a layer-by-layer basis and also gives clear insight into the evolution of the amplitude reflectance on a multilayer as it builds up. An optical criterion is derived for the selection of a proper pair of materials needed for designing a high-reflectance multilayer. Some examples are given to illustrate the usefulness of this design method.

  9. EUV and Soft X-Ray Emissions From Comets

    NASA Astrophysics Data System (ADS)

    Krasnopolsky, V. A.

    2001-05-01

    We analyzed 8 observations of comets with the Extreme Ultraviolet Explorer (EUVE). A soft X-ray camera in the range of 97-165 eV FWHM with a peak effective area of 28 cm2 and three spectrometers at 80-180, 170-360, and 300-720 Å with peak effective areas of 2.1, 0.5, and 0.8 cm2, respectively, were used for those observations. The detection limit of the X-ray camera corresponds to the X-ray luminosity of 1.9x 1014 Δ 2 erg s-1 for photon energy ɛ > 100 eV. (Δ is the geocentric distance in AU.) Five comets were detected with the X-ray camera: Hyakutake, Borrelly, d'Arrest, pre- and postperihelion Hale-Bopp. Their images reveal a crescent-like structure with peak brightness offsets from the nuclei between the sunward and comet orbital velocity directions. X-ray luminosities and their spatial distributions were determined from the observations. The measured luminosities are in excellent correlation with gas production rates in comets, resulting in the efficiency of (6.4 +/- 0.9)x 10-5 AU3/2 in the range of 97-165 eV. Correlation with dust production rates is poor, and this favor a gas-related excitation process. The peak brightnesses scaled to r2 are constant and equal to 26+/- 9 millirayleighs. This means that comae are optically or collisionally thick near the brightness centers. Of a few suggested excitation mechanisms, only charge exchange between solar wind heavy ions and cometary neutrals agrees with both these facts. The EUVE spectra of comets Hale-Bopp and Hyakutake have been analyzed. Due to the close flyby of Hyakutake at 0.1 AU, its spectra are of exceptionally high quality and exceed the currently published spectra of comets by a factor of 3 in resolving power and by two orders of magnitude in photon statistics. The spectra reveal for the first time the emission lines of multiple charged ions which are brought to the comet by the solar wind and excited in charge exchange with cometary neutral species. The most prominent lines are O4+ 215 Å, C4+ 249

  10. 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.

  11. 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.

  12. The structure of the coronal soft X-ray source associated with the dark filament disappearance of 1991 September 28 using the Yohkoh Soft X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Mcallister, Alan; Uchida, Yutaka; Tsuneta, Saku; Strong, Keith T.; Acton, Loren W.; Hiei, Eijiro; Bruner, Marilyn E.; Watanabe, Takashi; Shibata, Kazunari

    1992-01-01

    The structure of the coronal soft X-ray source associated with the dark filament disappearance on September 28, 1991, observed with the Soft X-ray Telescope, is examined as a possible example of the 'eruption-reconnection' model of filament disappearance. The results suggest, however, that this model may not fit. There is a strong possibility that much of the dark filament mass remains in the heated unwinding axial field.

  13. Rapid, Absolute Calibration of X-ray Filters Employed By Laser-Produced Plasma Diagnostics

    SciTech Connect

    Brown, G V; Beiersdorfer, P; Emig, J; Frankel, M; Gu, M F; Heeter, R F; Magee, E; Thorn, D B; Widmann, K; . Kelley, R L; Kilbourne, C A; Porter, F S

    2008-05-11

    The electron beam ion trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of X-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen X-ray energies. X-rays are detected using the high-resolution EBIT calorimeter spectrometer (ECS), developed for LLNL at the NASA/Goddard Space Flight Center. X-ray filter transmission efficiency is determined by dividing the X-ray counts detected when the filter is in the line of sight by those detected when out of the line of sight. Verification of filter thickness can be completed in only a few hours, and absolute efficiencies can be calibrated in a single day over a broad range from about 0.1 to 15 keV. The EBIT calibration lab has been used to field diagnostics (e.g., the OZSPEC instrument) with fully calibrated X-ray filters at the OMEGA laser. Extensions to use the capability for calibrating filter transmission for the DANTE instrument on the National Ignition Facility are discussed.

  14. Toward the development of a soft x-ray reflection imaging microscope in the Schwarzschild configuration using a soft x-ray laser at 18. 2 nm

    SciTech Connect

    Dicicco, D.; Rosser, R. ); Kim, D.; Suckewer, S. . Plasma Physics Lab.)

    1991-12-01

    We present the recent results obtained from a soft X-ray reflection imaging microscope in the Schwarzschild configuration. The microscope demonstrated a spatial resolution of 0.7 {mu}m with a magnification of 16 at 18.2 nm. The soft X-ray laser at 18.2 nm was used as an X-ray source. Mo/Si multilayers were coated on the Schwarzschild optics and the normal incidence reflectivity at 18.2 nm per surface was measured to be {approximately} 20 %. 18 refs., 6 figs.

  15. 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.

  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. 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.

  18. High-efficiency fast scintillators for 'optical' soft x-ray arrays for laboratory plasma diagnostics

    SciTech Connect

    Delgado-Aparicio, L. F.; Stutman, D.; Tritz, K.; Vero, R.; Finkenthal, M.; Suliman, G.; Kaita, R.; Majeski, R.; Stratton, B.; Roquemore, L.; Tarrio, C

    2007-08-20

    Scintillator-based 'optical' soft x-ray (OSXR) arrays have been investigated as a replacement for the conventional silicon (Si)-based diode arrays used for imaging, tomographic reconstruction, magnetohydrodynamics, transport, and turbulence studies in magnetically confined fusion plasma research. An experimental survey among several scintillator candidates was performed, measuring the relative and absolute conversion efficiencies of soft x rays to visible light. Further investigations took into account glass and fiber-optic faceplates (FOPs) as substrates, and a thin aluminum foil(150 nm) to reflect the visible light emitted by the scintillator back to the optical detector.Columnar (crystal growth) thallium-doped cesium iodide (CsI:Tl) deposited on an FOP, was found to be the best candidate for the previously mentioned plasma diagnostics.Its luminescence decay time of the order of?1-10 {mu}s is thus suitable for the 10 {mu}s time resolution required for the development of scintillator-based SXR plasma diagnostics. A prototype eight channel OSXR array using CsI:Tl was designed, built,and compared to an absolute extreme ultraviolet diode counterpart: its operation on the National Spherical Torus Experiment showed a lower level of induced noise relative to the Si-based diode arrays, especially during neutral beam injection heated plasma discharges. The OSXR concept can also be implemented in less harsh environments for basic spectroscopic laboratory plasma diagnostics.

  19. High-efficiency blazed transmission gratings for high-resolution soft x-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Heilmann, Ralf K.; Bruccoleri, Alexander R.; Schattenburg, Mark L.

    2015-09-01

    High-resolution spectroscopy of astrophysical sources is the key to gaining a quantitative understanding of the history, dynamics, and current conditions of the cosmos. A large-area (> 1,000 cm2), high resolving power (R = λ/Δλ> 3000) soft x-ray grating spectrometer (XGS) that covers the lines of C, N, O, Ne and Fe ions is the ideal tool to address a number of high-priority science questions from the 2010 Decadal Survey, such as the connection between super-massive black holes and large-scale structure via cosmic feedback, the evolution of large- scale structure, the behavior of matter at high densities, and the conditions close to black holes. While no grating missions or instruments are currently approved, an XGS aboard a potential future X-ray Surveyor could easily surpass the above performance metrics. To improve the chances for future soft x-ray grating spectroscopy missions or instruments, grating technology has to progress and advance to higher Technology Readiness Levels (TRLs). To that end we have developed Critical-Angle Transmission (CAT) gratings that combine the advantages of blazed reflection gratings (high efficiency, use of higher diffraction orders) with those of conventional transmission gratings (low mass, relaxed alignment tolerances and temperature requirements, high transparency at higher energies). A CAT grating-based spectrometer can provide performance 1-2 orders of magnitude better than current grating instruments on Chandra and Newton-XMM with minimal resource requirements. At present we have fabricated large-area freestanding CAT gratings with narrow integrated support structures from silicon-on- insulator wafers using advanced lithography and a combination of deep reactive-ion and wet etching. Our latest x-ray test results show record high absolute diffraction efficiencies in blazed orders in excess of 30% with room for improvement.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. A Soft X-Ray/EUV Reflectometer Based on a Laser Produced Plasma Source.

    PubMed

    Gullikson, E M; Underwood, J H; Batson, P C; Nikitin, V

    1992-01-01

    A soft x-ray reflectometer is described which is based on a laser-produced plasma source and is continuously tunable over the range 40 Å < λ < 400 Å. The source is produced by focusing 0.532-μm light from a Q-switched Nd:YAG laser on a solid target. The x-ray wavelength is defined using a high throughput spherical grating monochromator with moderate resolving power (λ/Δλ ≈ 100 to 500). A time-averaged monochromatized flux of more than 109 photons/s in a 1% bandwidth at 100 eV is obtained. Photon "shot noise" limited measurements are obtained by the use of an I0 detector to normalize out the shot-to-shot variations in source intensity. Measurements with submillimeter spot sizes are readily obtainable. Various detectors have been used and the advantages and disadvantages of each are discussed. The higher order contamination of the monochromator output has been analyzed using a second grating for the purpose of making measurement corrections. The reflectometer thus provides the capability for precision absolute measurements of the reflectance of gratings and multilayer mirrors, the transmittance of thin film filters, or other properties of x-ray optical elements.

  5. High-precision laser-assisted absolute determination of x-ray diffraction angles

    SciTech Connect

    Kubicek, K.; Braun, J.; Bruhns, H.; Crespo Lopez-Urrutia, J. R.; Mokler, P. H.; Ullrich, J.

    2012-01-15

    A novel technique for absolute wavelength determination in high-precision crystal x-ray spectroscopy recently introduced has been upgraded reaching unprecedented accuracies. The method combines visible laser beams with the Bond method, where Bragg angles ({theta} and -{theta}) are determined without any x-ray reference lines. Using flat crystals this technique makes absolute x-ray wavelength measurements feasible even at low x-ray fluxes. The upgraded spectrometer has been used in combination with first experiments on the 1s2p {sup 1}P{sub 1}{yields} 1s{sup 2} {sup 1}S{sub 0} w-line in He-like argon. By resolving a minute curvature of the x-ray lines the accuracy reaches there the best ever reported value of 1.5 ppm. The result is sensitive to predicted second-order QED contributions at the level of two-electron screening and two-photon radiative diagrams and will allow for the first time to benchmark predicted binding energies for He-like ions at this level of precision.

  6. 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.

  7. Solar flare hard and soft x ray relationship determined from SMM HXRBS and BCS data

    NASA Technical Reports Server (NTRS)

    Toot, G. David

    1989-01-01

    The exact nature of the solar flare process is still somewhat a mystery. A key element to understanding flares if the relationship between the hard x rays emitted by the most energetic portions of the flare and the soft x rays from other areas and times. This relationship was studied by comparing hard x ray light curved from the Hard X-Ray Burst Spectrometer (HXRBS) with the soft x ray light curve and its derivation from the Bent Crystal Spectrometer (BCS) which is part of the X-Ray Polychrometer (XRP), these instruments being on the Solar Maximum Mission spacecraft (SMM). Data sample was taken from flares observed with the above instruments during 1980, the peak of the previous maximum of solar activity. Flares were chosen based on complete coverage of the event by several instruments. The HXRBS data covers the x ray spectrum from about 25 keV to about 440 keV in 15 spectral channels, while the BCS data used covers a region of the Spectrum around 3 angstroms including emission from the Ca XIX ion. Both sets of data were summed over their spectral ranges and plotted against time at a maximum time resolution of around 3 seconds. The most popular theory of flares holds that a beam of electrons produces the hard x rays by bremsstrahlung while the soft x rays are the thermal response to this energy deposition. The question is whether the rate of change of soft x ray emission might reflect the variability of the electron beam and hence the variability of the hard x rays. To address this, we took the time derivative of the soft x ray light curve and compared it to the hard flares, 12 of them showed very closed agreement between the soft x ray derivative and the hard x ray light curve. The other five did not show this behavior but were similar to each other in general soft x ray behavior. Efforts to determine basic differences between the two kinds of flares continue. In addition the behavior of soft x ray temperature of flares was examined.

  8. 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.

  9. An imaging diode array soft x-ray diagnostic for Z (abstract)

    NASA Astrophysics Data System (ADS)

    Simpson, W. W.; Porter, J. L.; Ruggles, L. E.; Wenger, D. F.

    2001-01-01

    Measurements of the hohlraum wall temperature in Z-pinch driven hohlraum experiments require looking through small (2-4 mm diameter) diagnostic holes that undergo some degree of hole closure. The existing soft x-ray diagnostics on Z measure the total flux exiting this diagnostic hole and are therefore affected by this hole closure. To avoid having to measure the effective diagnostic hole area we have designed and constructed an imaging diode array (IDA) that incorporates pinhole imaging and an array of filtered silicon diodes to measure the absolute x-ray intensity from a spatially resolved region of a target. The instrument uses silicon diodes with subnanosecond time response that are sensitive to soft x rays in the range 100-3000 eV. An image of the target area is projected onto the silicon diodes using pinholes. Between each pinhole and it's respective diode is a soft x-ray filter. The material and thickness of the filter are selected to allow unfolding of spectral information in the 100-3000 eV spectral region. We plan to insert a set of grazing-incidence mirrors between each of the filter/diode pairs in a future version of this instrument to better define the spectral bandpass of each diode channel. Radiation from the target region is monitored by a gated microchannel-plate-intensified image recording device that is located immediately behind the diode array. A small shadow in the recorded image corresponds to the specific area of the target that is imaged onto each silicon diode. We are presently fielding this instrument in experiments on the Z facility located at Sandia National Laboratories in Albuquerque, NM. The instrument is located on the same line-of-sight and measures the same spatial region as a filtered fast-framing x-ray pinhole camera and a transmission grating spectrometer. This article describes the design of the IDA diagnostic and presents the results of measurements obtained in hohlraum experiments conducted on Z.

  10. The prospects for soft x-ray contact microscopy using laser plasmas as an x-ray source

    SciTech Connect

    Stead, A.D.; Page, A.M.; Ford, T.W.

    1995-12-31

    Since its invention, a major concern of those using a microscope has been to improve the resolution without the introduction of artifacts. While light microscopy carries little risk of the introduction of artifacts, because the preparative techniques are often minimal, the resolution is somewhat limited. The advent of the electron microscope offered greatly improved resolution but since biological specimens require extensive preparation, the possibility of causing structural damage to the specimen is also increased. The ideal technique for structural studies of biological specimens would enable hydrated material to be examined without any preparation and with a resolution equal to that of electron microscopy. Soft x-ray microscopy certainly enables living material to be examined and whilst the resolution does not equal that of electron microscopy it exceeds that attainable by light microscopy. This paper briefly reviews the limitations of light and electron microscopy for the biologist and considers the various ways that soft x-rays might be used to image hydrated biological material. Consideration is given to the different sources that have been used for soft x-ray microscopy and the relative merits of laser-plasma sources are discussed.

  11. Soft X-ray probes of ultrafast dynamics for heterogeneous catalysis

    NASA Astrophysics Data System (ADS)

    Beye, M.; Föhlisch, A.

    2013-03-01

    Soft X-ray spectroscopy is one of the best tools to directly address the electronic structure, the driving force of chemical reactions. It enables selective studies on sample surfaces to single out reaction centers in heterogeneous catalytic reactions. With core-hole clock methods, specific dynamics are related to the femtosecond life time of a core-hole. Typically, this method is used with photoemission spectroscopy, but advancements in soft X-ray emission techniques render more specific studies possible. With the advent of bright femtosecond pulsed soft X-ray sources, highly selective pump-probe X-ray emission studies are enabled with temporal resolutions down to tens of femtoseconds. This finally allows to study dynamics in the electronic structure of adsorbed reaction centers on the whole range of relevant time scales - closing the gap between kinetic soft X-ray studies and the atto- to femtosecond core-hole clock techniques.

  12. Soft x-ray detection with diamond photoconductive detectors

    SciTech Connect

    Kania, D.R.; Pan, L.; Kornblum, H.; Bell, P.; Landen, O.N.; Pianetta, P.

    1990-05-04

    Photoconductive detectors fabricated from natural lla diamonds have been used to measure the x-ray power emitted from laser produced plasmas. The detector was operated without any absorbing filters to distort the x-ray power measurement. The 5.5 eV bandgap of the detector material practically eliminates its sensitivity to scattered laser radiation thus permitting filterless operation. The detector response time or carrier life time was 90 ps. Excellent agreement was achieved between a diamond PCD and a multichannel photoemissive diode array in the measurement of radiated x-ray power and energy. 4 figs.

  13. 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.

  14. 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.

  15. Tunable thin film polarizer for the vacuum ultraviolet and soft x-ray spectral regions

    SciTech Connect

    Yang, Minghong; Cobet, Christoph; Esser, Norbert

    2007-03-01

    A low pass polarizer that suppresses higher-order diffraction light from vacuum ultraviolet and soft x-ray monochromators is presented in this paper. This vacuum ultraviolet and soft x-ray polarizer is based on a concept of sandwiched metal-dielectric-metal triple reflection configuration. By appropriate optimization of material and angle of incidence, the proposed Au-SiC-Au polarizer demonstrates the capability of matching to desired cutoff edge of photon energy. Furthermore, the optimized soft x-ray polarizer shows the possibility to tune cutoff photon energy in a broadband spectral region ranging from 80 down to down to 20 eV.

  16. Soft X-Ray Emission from Alexandrite Laser-Matter-Interaction

    DTIC Science & Technology

    1993-07-15

    34AD-A267 905 NRL/MR/6681--93-7359 Soft X-ray Emission from Alexandrite Laser-Matter-Interaction P. G. BURKHALTER Dvnamit s of Solids Branch Condensed...Soft X-ray Emission from Alexandrite Laser-Matter-Interaction 6. AUTHOR(S) P.G. Burkhalter, D.J. Harter*, E.F. Gabl**, P. Bado**, and D.A. Newman*** 7...Proscribed by ANSI Std 230-13 290-102 SOFT X-RAY EMISSION FROM ALEXANDRITE LASER-MATTER-INTERACTION Accesion For NTIS CRA&I DTIC TAB Unannounced 5

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. X-ray Imaging of Mucilaginous Sheath of Phytoplankton in Lake Biwa by Soft X-ray Microscope

    NASA Astrophysics Data System (ADS)

    Takemoto, K.; Ichise, S.; Ohigashi, T.; Namba, H.; Kihara, H.

    2011-09-01

    In Lake Biwa, the chemical oxygen demand (COD) index is increasing in spite of a decrease in the values of the biochemical oxygen demand (BOD) index. Picophytoplankton with a mucilaginous sheath is considered an important source of non-biodegradable organic compounds. In order to elucidate the mechanism, x-ray images of planktons inhabiting Lake Biwa were taken. The laboratory-cultured phytoplanktons with sheaths—Synechoccoucs, Microcystis wesenbergii, and Phormidium tenue—were observed by the soft x-ray microscope (BL12) of the Ritsumeikan University SR Center. Synechoccoucs cells were successfully observed with high contrast, and the mucilaginous sheath around the cell was also observed. However, although P. tenu cells were successfully observed with high contrast, it was impossible to confirm the mucilaginous sheath around the cell.

  2. Quantitative evaluation of radiation damage to polyethylene terephthalate by soft X-rays and high-energy electrons.

    PubMed

    Wang, Jian; Botton, Gianluigi A; West, Marcia M; Hitchcock, Adam P

    2009-02-19

    The chemical changes and absolute rates in radiation damage to polyethylene terephthalate (PET) caused by soft X-rays and energetic electrons have been measured using a scanning transmission X-ray microscope (STXM). Electron beam damage at two different dose rates and a range of doses was performed in an 80 keV transmission electron microscope (TEM). The STXM beam was used to create damage patterns with systematically varied doses of monochromatic soft X-rays on an adjacent piece of the same PET sample. NEXAFS spectroscopy at the C 1s and O 1s edges was used to study the chemistry of the radiation damage and to determine quantitative critical doses for PET damage by both types of radiation. The spectral changes were similar for damage by electrons and X-rays, indicating the radiation chemistry is dominated by secondary processes, not the primary event. The critical dose for chemical changes determined from C 1s spectral features is 4.2(6) x 10(8) Gy and was the same for soft X-rays and electrons within measurement uncertainties. The critical dose for specific damage processes (as defined by changes in several different, bond-specific spectral features) was found to be similar in the C 1s region and was comparable between C 1s and O 1s edges for electron beam damage. There were statistically different critical doses for soft X-ray damage as probed by changes in O 1s spectral features related to carbonyl and ester bonds.

  3. Biological imaging by soft x-ray diffraction microscopy

    DOE PAGES

    Shapiro, D.; Thibault, P.; Beetz, T.; ...

    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

  4. 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.

  5. 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.

  6. Exploring the Hard and Soft X-ray Emission of Magnetic Cataclysmic Variables

    NASA Astrophysics Data System (ADS)

    de Martino, D.; Anzolin, G.; Bonnet-Bidaud, J.-M.; Falanga, M.; Matt, G.; Mouchet, M.; Mukai, K.; Masetti, N.

    2009-05-01

    A non-negligible fraction of galactic hard (>20 keV) X-ray sources were identified as CVs of the magnetic Intermediate Polar type in INTEGRAL, SWIFT and RXTE surveys, that suggests a still hidden but potentially important population of faint hard X-ray sources. Simbol-X has the unique potential to simultaneously characterize their variable and complex soft and hard X-ray emission thus allowing to understand their putative role in galactic populations of X-ray sources.

  7. Soft x-ray source for nanostructure imaging using femtosecond-laser-irradiated clusters

    NASA Astrophysics Data System (ADS)

    Fukuda, Y.; Faenov, A. Ya.; Pikuz, T.; Kando, M.; Kotaki, H.; Daito, I.; Ma, J.; Chen, L. M.; Homma, T.; Kawase, K.; Kameshima, T.; Kawachi, T.; Daido, H.; Kimura, T.; Tajima, T.; Kato, Y.; Bulanov, S. V.

    2008-03-01

    The intense soft x-ray light source using the supersonic expansion of the mixed gas of He and CO2, when irradiated by a femtosecond Ti:sapphire laser pulse, is observed to enhance the radiation of soft x-rays from the CO2 clusters. Using this soft x-ray emissions, nanostructure images of 100-nm-thick Mo foils in a wide field of view (mm2 scale) with high spatial resolution (800nm ) are obtained with high dynamic range LiF crystal detectors. The local inhomogeneities of soft x-ray absorption by the nanometer-thick foils is measured with an accuracy of less than ±3%.

  8. Soft x-ray source for nanostructure imaging using femtosecond-laser-irradiated clusters

    SciTech Connect

    Fukuda, Y.; Kando, M.; Kotaki, H.; Daito, I.; Ma, J.; Chen, L. M.; Homma, T.; Kawase, K.; Kameshima, T.; Kawachi, T.; Daido, H.; Kimura, T.; Tajima, T.; Kato, Y.; Bulanov, S. V.; Faenov, A. Ya.; Pikuz, T.

    2008-03-24

    The intense soft x-ray light source using the supersonic expansion of the mixed gas of He and CO{sub 2}, when irradiated by a femtosecond Ti:sapphire laser pulse, is observed to enhance the radiation of soft x-rays from the CO{sub 2} clusters. Using this soft x-ray emissions, nanostructure images of 100-nm-thick Mo foils in a wide field of view (mm{sup 2} scale) with high spatial resolution (800 nm) are obtained with high dynamic range LiF crystal detectors. The local inhomogeneities of soft x-ray absorption by the nanometer-thick foils is measured with an accuracy of less than {+-}3%.

  9. Coherent soft x-ray generation in the water window with quasi-phase matching.

    PubMed

    Gibson, Emily A; Paul, Ariel; Wagner, Nick; Tobey, Ra'anan; Gaudiosi, David; Backus, Sterling; Christov, Ivan P; Aquila, Andy; Gullikson, Eric M; Attwood, David T; Murnane, Margaret M; Kapteyn, Henry C

    2003-10-03

    We demonstrate enhanced generation of coherent light in the "water window" region of the soft x-ray spectrum at 4.4 nanometers, using quasi-phase-matched frequency conversion of ultrafast laser pulses. By periodically modulating the diameter of a gas-filled hollow waveguide, the phase mismatch normally present between the laser light and the generated soft x-ray light can be partially compensated. This makes it possible to use neon gas as the nonlinear medium to coherently convert light up to the water window, illustrating that techniques of nonlinear optics can be applied effectively in the soft x-ray region of the spectrum. These results advance the prospects for compact coherent soft x-ray sources for applications in biomicroscopy and in chemical spectroscopy.

  10. Laboratory arrangement for soft x-ray zone plate efficiency measurements

    SciTech Connect

    Bertilson, Michael C.; Takman, Per A. C.; Holmberg, Anders; Vogt, Ulrich; Hertz, Hans M.

    2007-02-15

    We demonstrate a laboratory-scale arrangement for rapid and accurate measurements of the absolute and local efficiency of soft x-ray micro zone plates in the water window. This in-house instrument is based on a single-line {lambda}=2.88 nm liquid-jet laser-plasma source. Measurements are performed by a simultaneous comparison of first diffraction-order photon flux with the flux in a calibrated reference signal. This arrangement eliminates existing source emission fluctuations. The performance of the method is demonstrated by the result from measurements of two {approx}55 {mu}m diameter nickel micro zone plates, showing a groove efficiency of 12.9%{+-}1.1% and 11.7%{+-}1.0%. Furthermore, we show that spatially resolved efficiency mapping is an effective tool for a detailed characterization of local zone plate properties. Thus, this laboratory-scale instrument allows rapid feedback to the fabrication process which is important for future improvements.

  11. High throughput measurements of soft x-ray impurity emission using a multilayer mirror telescope

    SciTech Connect

    Stutman, D.; Tritz, K.; Delgado-Aparicio, L.; Finkenthal, M.; Suliman, G.; Roquemore, L.; Kaita, R.; Kugel, H.; Johnson, D.; Tamura, N.; Sato, K.; Sudo, S.; Tarrio, C.

    2006-10-15

    A 4 in. multilayer mirror telescope has been tested on National Spherical Torus Experiment (NSTX) for high throughput measurements of the beam excited soft x-ray impurity emission. The design is aimed at imaging low-k turbulent fluctuations in the plasma core. The test device used curved and planar Mo/Si mirrors to focus with {approx_equal}15% optical transmission and few angstrom bandwidths, the 135 A ring Ly{sub {alpha}} line from injected Li III atoms, or the n=2-4 line from intrinsic C VI ions. As test detectors we used 1 cm{sup 2} absolute extreme ultraviolet diodes, equipped with 400 kHz bandwidth, low noise preamplifiers. With the available view on NSTX the telescope successfully detected small impurity density fluctuations associated with 1/1 modes rotating at midradius, indicating that a high signal to noise ratio and cost effective core turbulence diagnostic is feasible based on this concept.

  12. Silicon photodiode soft x-ray detectors for pulsed power experiments

    SciTech Connect

    Idzorek, G.C.; Bartlett, R.J.

    1997-10-01

    Silicon photodiodes offer a number of advantages over conventional photocathode type soft x-ray detectors in pulsed power experiments. These include a nominally flat response, insensitivity to surface contamination, low voltage biasing requirements, sensitivity to low energy photons, excellent detector to detector response reproducibility, and ability to operate in poor vacuum or gas backfilled experiments. Silicon photodiodes available from International Radiation Detectors (IRD), Torrance, California have been characterized for absolute photon response from 1 eV to 10 keV photon energy, time response, and signal saturation levels. The authors calibration measurements show factor of ten deviations from the silicon photodiode theoretical flat response due to diode sensitivity outside the center `sensitive area`. Detector response reproducibility between diodes appears to be better than 5%. Time response measurements show a 10-90% rise time of about 0.1 nanoseconds and a fall time of about 0.5 nanoseconds.

  13. Enhanced soft X-ray detection efficiencies for imaging microchannel plate detectors

    NASA Astrophysics Data System (ADS)

    Fraser, G. W.; Barstow, M. A.; Whiteley, M. J.; Wells, A.

    1982-12-01

    Although the microchannel plate (MCP) electron multipliers used in X-ray astronomy facilitate X-ray imaging with high spatial resolution, their intrinsic soft X-ray detection efficiencies of 1-10 percent are much lower than the near-unity values available with competing gas proportional counters. A high photoelectric yield material may be deposited on the MCP front surface and channel walls in order to enhance X-ray sensitivity at energies below a few keV. High 0.18-1.5 keV X-ray detection efficiencies are reported for MCPs bearing CsI deposition photocathodes, by which efficiency enhancement factors of up to 15 have been obtained. These results are especially pertinent to the sensitivity of such future X-ray astronomy experiments as the Roentgensatellit (Rosat) Wide Field Camera.

  14. 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.

  15. 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.

  16. The possible effect of solar soft X rays on thermospheric nitric oxide

    NASA Technical Reports Server (NTRS)

    Siskind, D. E.; Barth, C. A.; Cleary, D. D.

    1990-01-01

    A rocket observation of nitric oxide in the lower thermosphere during a time of high solar activity is compared to the results of calculations from a one-dimensional photochemical model. A solar soft X-ray flux of 0.75 erg/sq cm/s is needed to explain the observed NO densities. This result supports the theory that the variation in the low-latitude thermospheric NO is caused by variation in solar soft X-rays.

  17. 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.

  18. The energy spectrum of anomalous X-ray pulsars and soft gamma-ray repeaters

    NASA Astrophysics Data System (ADS)

    Trümper, J. E.; Zezas, A.; Ertan, Ü.; Kylafis, N. D.

    2010-07-01

    Context. Anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) exhibit characteristic X-ray luminosities (both soft and hard) of around 1035 erg s-1 and characteristic power-law, hard X-ray spectra extending to about 200 keV. Two AXPs also exhibit pulsed radio emission. Aims: Assuming that AXPs and SGRs accrete matter from a fallback disk, we attempt to explain both the soft and the hard X-ray emission as the result of the accretion process. We also attempt to explain their radio emission or the lack of it. Methods: We test the hypothesis that the power-law, hard X-ray spectra are produced in the accretion flow mainly by bulk-motion Comptonization of soft photons emitted at the neutron star surface. Fallback disk models invoke surface dipole magnetic fields of 1012 - 1013 G, which is what we assume here. Results: Unlike normal X-ray pulsars, for which the accretion rate is highly super-Eddington, the accretion rate is approximately Eddington in AXPs and SGRs and thus the bulk-motion Comptonization operates efficiently. As an illustrative example we reproduce both the hard and the soft X-ray spectra of AXP 4U 0142+61 well using the XSPEC package compTB. Conclusions: Our model seems to explain both the hard and the soft X-ray spectra of AXPs and SGRs, as well as their radio emission or the lack of it, in a natural way. It might also explain the short bursts observed in these sources. On the other hand, it cannot explain the giant X-ray outbursts observed in SGRs, which may result from the conversion of magnetic energy in local multipole fields.

  19. 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.

  20. [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.

  1. 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.

  2. 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.

  3. Lensless diffractive imaging using tabletop coherent high-harmonic soft-X-ray beams.

    PubMed

    Sandberg, Richard L; Paul, Ariel; Raymondson, Daisy A; Hädrich, 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.

  4. The Soft X-ray Telescope for Solar-A - Design evolution and lessons learned

    NASA Technical Reports Server (NTRS)

    Bruner, Marilyn E.

    1992-01-01

    The Japanese Solar-A satellite mission's Soft X-ray Telescope uses grazing-incidence optics, a CCD detector, and a pair of filter wheels for wavelength selection. A coaxially-mounted visible-light lens furnished sunspot and magnetic plage images, together with aspect information which aids in aligning the soft X-ray images with those from the satellite's Hard X-ray Telescope. Instrument electronics are microprocessor-based, and imbedded in a tightly integrated distributed system. Control software is divided between the instrument microprocessor and the spacecraft control computer.

  5. 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.

  6. 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.

  7. Development of a Time-resolved Soft X-ray Spectrometer for Laser Produced Plasma Experiments

    SciTech Connect

    Cone, K V; Dunn, J; Schneider, M B; Baldis, H A; Brown, G V; Emig, J; James, D L; May, M J; Park, J; Shepherd, R; Widmann, K

    2010-05-12

    A 2400 line/mm variable spaced grating spectrometer (VSG) has been used to measure soft x-ray emission (8-22 {angstrom}) from laser-produced plasma experiments at Lawrence Livermore National Laboratory's Compact Multipulse Terrawatt (COMET) Laser Facility. The spectrometer was coupled to a Kentech x-ray streak camera to study the temporal evolution of soft x-rays emitted from the back of mylar and copper foils irradiated at 10{sup 15} W/cm{sup 2}. The instrument demonstrated a resolving power of {approx} 120 at 19 {angstrom} with a time resolution of 31 ps. The time-resolved copper emission spectrum was consistent with a photodiode monitoring the laser temporal pulse shape and indicated that the soft x-ray emission follows the laser heating of the target. The time and spectral resolution of this diagnostic make it useful for studies of high temperature plasmas.

  8. 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.

  9. Emission Angles for Soft X-Ray Coherent Transition Radiation.

    DTIC Science & Technology

    1987-09-01

    possible sources of error are cited. Acceso ;i For NTIS CRA&I i IC TAB L AW 4i 3 TABLE OF CONTENTS I. INTRODUCTION...addition of radiation from multiple foil stacks and the use of transition radiation as a particle beam detector [Ref. 2:p. 3594). E Use of transition...radiation to measure the energy of * electrons in early studies was restricted by the absorption of the x-rays by multiple dielectric foil stacks. The high 7

  10. 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.

  11. Bond cleavages of adenosine 5'-triphosphate induced by monochromatic soft X-rays

    NASA Astrophysics Data System (ADS)

    Fujii, K.; Narita, A.; Yokoya, A.

    2014-04-01

    To investigate which type of bond is likely to be cleaved by soft X-ray exposure to an adenosine 5'-triphosphate (ATP), we observed spectral changes in X-ray absorption near edge structure (XANES) around nitrogen and oxygen K-edge of an ATP film by soft X-ray irradiation. Experiments were performed at a synchrotron soft X-ray beamline at SPring-8, Japan. The XANES spectra around the nitrogen and oxygen .K-edge slightly varied by exposure to 560 eV soft X-rays. These changes are originated from the cleavage of C-N bonds between a sugar and a nucleobase site and of C-O, P-O or O-H bond of sugar and phosphate site. From the comparison between the change in XANES intensity of σ* peak at nitrogen and that at oxygen K-edges, it is inferred that the C-O, P-O or O-H bond of sugar and phosphate is much efficiently cleaved than the C-N of N-glycoside bond by the exposure of 560 eV soft X-ray to ATP film.

  12. Population inversion and gain measurements for soft x-ray-laser development in a magnetically confined plasma column

    SciTech Connect

    Suckewer, S.; Skinner, C.H.; Voorhees, D.; Milchberg, H.; Keane, C.; Semet, A.

    1983-06-01

    We present population inversion and gain measurements from an experimental investigation of possibilities to obtain high gain and lasing action in the soft x-ray region. Our approach to soft x-ray-laser development is based on rapid plasma cooling after the laser pulse by radiation losses, leading to fast recombination and collisional cascade into upper excited levels of CVI, for example, while the lower excited levels depopulate rapidly by radiative transitions, thus creating population inversions and gain. A approx. = 0.5 kJ CO/sub 2/ laser was focused onto a target of solid carbon or teflon; or CO/sub 2/, O/sub 2/, Ne gas, and the resulting plasma confined in a 50 to 90 kG magnetic field. Spectroscopic diagnostics with absolute intensity calibration were used to measure level populations.

  13. Correlative Analysis of hard and Soft X-rays in Solar Flares using CGRO/BATSE and YOHKOH

    NASA Technical Reports Server (NTRS)

    Zarro, Dominic M.

    1996-01-01

    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 Bragg Crystal Spectrometer (BCS) and Soft X-ray telescope (SXT) on the Japanese Yohkoh spacecraft.

  14. Determination of the absolute chirality of tellurium using resonant diffraction with circularly polarized x-rays.

    PubMed

    Tanaka, Y; Collins, S P; Lovesey, S W; Matsumami, M; Moriwaki, T; Shin, S

    2010-03-31

    Many proteins, sugars and pharmaceuticals crystallize into two forms that are mirror images of each other (enantiomers) like our right and left hands. Tellurium is one enantiomer having a space group pair, P3(1)21 (right-handed screw) and P3(2)21 (left-handed screw). X-ray diffraction with dispersion correction terms has been playing an important role in determining the handedness of enantiomers for a long time. However, this approach is not applicable for an elemental crystal such as tellurium or selenium. We have demonstrated that positive and negative circularly polarized x-rays at the resonant energy of tellurium can be used to absolutely distinguish right from left tellurium. This method is applicable to chiral motifs that occur in biomolecules, liquid crystals, ferroelectrics and antiferroelectrics, multiferroics, etc.

  15. The use of X-ray crystallography to determine absolute configuration.

    PubMed

    Flack, H D; Bernardinelli, G

    2008-05-15

    Essential background on the determination of absolute configuration by way of single-crystal X-ray diffraction (XRD) is presented. The use and limitations of an internal chiral reference are described. The physical model underlying the Flack parameter is explained. Absolute structure and absolute configuration are defined and their similarities and differences are highlighted. The necessary conditions on the Flack parameter for satisfactory absolute-structure determination are detailed. The symmetry and purity conditions for absolute-configuration determination are discussed. The physical basis of resonant scattering is briefly presented and the insights obtained from a complete derivation of a Bijvoet intensity ratio by way of the mean-square Friedel difference are exposed. The requirements on least-squares refinement are emphasized. The topics of right-handed axes, XRD intensity measurement, software, crystal-structure evaluation, errors in crystal structures, and compatibility of data in their relation to absolute-configuration determination are described. Characterization of the compounds and crystals by the physicochemical measurement of optical rotation, CD spectra, and enantioselective chromatography are presented. Some simple and some complex examples of absolute-configuration determination using combined XRD and CD measurements, using XRD and enantioselective chromatography, and in multiply-twinned crystals clarify the technique. The review concludes with comments on absolute-configuration determination from light-atom structures.

  16. 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.

  17. Young Stellar Objects from Soft to Hard X-rays

    NASA Astrophysics Data System (ADS)

    Güdel, Manuel

    2009-05-01

    Magnetically active stars are the sites of efficient particle acceleration and plasma heating, processes that have been studied in detail in the solar corona. Investigation of such processes in young stellar objects is much more challenging due to various absorption processes. There is, however, evidence for violent magnetic energy release in very young stellar objects. The impact on young stellar environments (e.g., circumstellar disk heating and ionization, operation of chemical networks, photoevaporation) may be substantial. Hard X-ray devices like those carried on Simbol-X will establish a basis for detailed studies of these processes.

  18. Soft X-ray bremsstrahlung and fluorescent line production in the atmosphere by low energy electrons

    NASA Technical Reports Server (NTRS)

    Kraushaar, W. L.

    1974-01-01

    The effect of low energy quasi-trapped or precipitating electrons which impact on the counter windows of soft X-ray detectors are discussed. The errors caused by X-rays produced in the residual atmosphere above a rocket-borne detector because of the resemblance to X-rays of cosmic origin are examined. The design and development of counter windows which make it possible to identify the atmospherically produced X-rays are described. Curves are presented to show the following: (1) preliminary low energy electron data from Atmospheric Explorer C, (2) X-ray flux in electron-excited nitrogen and oxygen, (3) typical proportional counter response to low energy cosmic rays, and (4) proportional counter response to X-radiation produced by electrons incident upon a gas of oxygen to nitrogen number of 0.4.

  19. On the Nature of Soft X-Ray Radiation in Comet Hyakutake 1996 B2

    NASA Astrophysics Data System (ADS)

    Krasnopolsky, V. A.

    1996-09-01

    EUVE and ROSAT observations of comet Hyakutake revealed radiation in the soft X-ray with an intensity in the order of 0.03 ph cm(-2) s(-1) at 0.12 a.u. from the comet. We discuss and develop methods to calculate emission of soft X-ray photons in cometary dust and gas by the following processes: (1) scattering and (2) fluorescence of solar X-rays; (3) K- and L-shell ionization by solar-wind protons and (4) electrons; (5) bremsstrahlung of solar-wind electrons; (6) cometary magnetospheric substorms; (7) collisions with interplanetary dust particles; and (8) the presence of very small particles with mass in the order of 10(-19) g in comets. These particles were detected in comet Halley by Utterback and Kissel (Astron. J. 100, 1315, 1990) using the PUMA and PIA dust analyzers from the Vega and Giotto spacecraft. Of all these processes, only very strong substorms and scattering, to a lesser extent, fluorescence and bremsstrahlung by very small particles are capable to produce the measured intensity of soft X-ray. Appearance of strong substorms during each observation event is not probable. Very small particles are a more plausible explanation of the observed soft X-ray emission. However, the mean particle mass of 4.6x 10(-19) g suggested by Utterback and Kissel implies that the total production of these particles exceeds that of gas by a factor of 3.6 (in mass) and is inconsistent with the polarization and color of comet Halley. Both polarization and color require a reduction of the mean mass to (1-2)x 10(-19) g. This reduction strongly affects the visible brightness of the particles, which is proportional to m(2) , with a relatively weak effect on the soft X-ray. Spatial distribution of soft X-ray in comet Hyakutake is consistent with the sunward ejection of dust (Krasnopolsky et al., Astron. Astrophys. 187, 707, 1987). Soft X-ray observations of comets may be a tool for the study and diagnostics of very small particles. According to current models, solar soft X-ray

  20. 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.

  1. The Onset Phase of "Soft" X-Ray Transients

    NASA Astrophysics Data System (ADS)

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

    2006-09-01

    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 J1655-40 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 RXTE project, NRAO, and ROTSE.

  2. Soft X-ray spectromicroscopy of cobalt uptake by cement.

    PubMed

    Dähn, Rainer; Vespa, Marika; Tyliszczak, Tolek; Wieland, Erich; Shuh, David K

    2011-03-01

    Scanning transmission X-ray microscopy was used to investigate the speciation and spatial distribution of Co in a Co(II)-doped cement matrix. The aim of this study was to improve the understanding of the heavy metals immobilization process in cement on the molecular level. The Co-doped cement samples hydrated for 30 days with a Co loading of 5000 mg/kg were prepared under normal atmosphere to simulate conditions used for cement-stabilized waste packages. Co 2p(3/2) absorption edge signals were used to determine the spatial distributions of the metal species in the Co(II)-doped cement. The speciation of Co was determined by collecting near-edge X-ray absorption fine structure spectra. On the basis of the shape of the absorption spectra, it was found that Co(II) is partly oxidized to Co(III). The correlation, respectively the anticorrelation with elements such as Al, Si, and Mn, show that Co(II) is predominantly present as Co-hydroxide-like phase as well as Co-phyllosilicate, whereas Co(III) tends to be incorporated only into a CoOOH-like phase. Thus, this study suggests that thermodynamic calculations of Co(II)-immobilization by cementitious systems should take into consideration not only the solubility of Co(II)-hydroxides but also Co(III) phases.

  3. A novel monochromator for ultrashort soft x-ray pulses

    NASA Astrophysics Data System (ADS)

    Brzhezinskaya, Maria; Firsov, Alexander; Holldack, Karsten; Kachel, Torsten; Mitzner, Rolf; Pontius, Niko; Stamm, Christian; Schmidt, Jan-Simon; Föhlisch, Alexander; Erko, Alexei

    2013-05-01

    Reflection zone plates (RZP), which consist of elliptical zone plates fabricated on a total external reflection mirror surface, can be effectively used to produce a monochromatic x-ray beam and to focus it at photon energies below 1400 eV. However, as RZPs are highly chromatic, they can be designed only for one specific photon energy. We alleviate this problem by using a novel approach: a Reflection Zone Plate Array (RZPA). Here, we report about successful implementation of novel monochromator based on RZPAs for experiments with 100 fs time resolution at the upgraded Femtoslicing facility at BESSY-II. Aiming at minimum losses in x-ray flux up to 2000 resolution, we fabricated and used an RZPA as a single optical element for diffraction and focusing. Nine Fresnel lenses, designed for the energies of 410 eV, 543 eV, 644 eV, 715 eV, 786 eV, 861 eV, 1221 eV and 1333 eV which correspond to the absorption edges of NK, O-K, Mn-L, Fe-L, Co-L, Ni-L, Gd-M and Dy-M, were fabricated on the same substrate with a diameter of 100 mm. At resolution E/ΔE up to 2000 all edges of other elements in that range (400-1400 eV) are covered, too.

  4. Coordinated soft X-ray and H-alpha observation of solar flares

    NASA Technical Reports Server (NTRS)

    Zarro, D. M.; Canfield, R. C.; Metcalf, T. R.; Lemen, J. R.

    1988-01-01

    Soft X-ray, Ca XIX, and H-alpha observations obtained for a set of four solar flares in the impulsive phase are analyzed. A blue asymmetry was observed in the coronal Ca XIX line during the soft-Xray rise phase in all of the events. A red asymmetry was observed simultaneously in chromospheric H-alpha at spatial locations associated with enhanced flare heating. It is shown that the impulsive phase momentum of upflowing soft X-ray plasma equalled that of the downflowing H-alpha plasma to within an order of magnitude. This supports the explosive chromospheric evaporation model of solar flares.

  5. A deep x ray survey in the Lockman hole and the soft x ray log N - log S

    NASA Technical Reports Server (NTRS)

    Hasinger, G.; Burg, R.; Giacconi, R.; Hartner, G.; Schmidt, M.; Truemper, J.; Zamorani, G.

    1992-01-01

    The longest pointed observation (152 ksec) with the Rosat position sensitive proportional counter in the direction of the absolutely lowest neutral hydrogen column density is discussed. 26 shallower fields from the Rosat medium sensivity survey are analyzed. 1176 X-ray sources were detected in at least one Rosat energy band in these fields covering a total solid angle of 9.3 deg; 661 of these sources constitute a statistically complete sample detected in the hard band with 0.5 to 2 keV fluxes greater than 2.5 times 10 to the power of minus 15 erg/sq cm s. The faintest limiting flux of the survey is analyzed. Detailed simulations show that confusion effects and other selection biases are relatively small and can be corrected for in the sample. From an analysis in the Lockman field, a best fit slope of approximately 1.8 is found for the extrapolation of the differential X-ray counts below 2.5 times 10 to the power of minus 15 erg/sq cm s. On the basis of this analysis an upper limit of approximately 25% can be found for a truly diffuse background component in the Rosat hard band.

  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. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Soft x-ray excited optical luminescence from poly(N-vinylcarbazole)

    NASA Astrophysics Data System (ADS)

    Naftel, S. J.; Kim, P.-S. G.; Sham, T. K.; Sammynaiken, R.; Yates, B. W.; Hu, Y.-F.

    2003-05-01

    X-ray excited optical luminescence (XEOL) using tunable soft x rays from a synchrotron light source, together with x-ray absorption fine structure spectroscopy has been used to study the electronic structure and optical properties of thin films of poly(N-vinylcarbazole). It is found that carbon core level excitation enhances the formation of excimers emitting at 380 and 410 nm. A third excimer at 310 nm is also noted. In addition, excitations across the C K edge and the N K edge show noticeably different optical response. These results are interpreted in terms of the site specificity of the XEOL technique.

  12. The soft X-ray telescope for the SOLAR-A mission

    NASA Technical Reports Server (NTRS)

    Tsuneta, S.; Acton, L.; Bruner, M.; Lemen, J.; Brown, W.; Caravalho, R.; Catura, R.; Freeland, S.; Jurcevich, B.; Owens, J.

    1991-01-01

    The Soft X-ray Telescope (SXT) of the SOLAR-A mission is designed to produce X-ray movies of flares with excellent angular and time resolution as well as full-disk X-ray images for general studies. A selection of thin metal filters provide a measure of temperature discrimination and aid in obtaining the wide dynamic range required for solar observing. The co-aligned SXT aspect telescope will yield optical images for aspect reference, white-light flare and sunspot studies, and, possibly, helioseismology. This paper describes the capabilities and characteristics of the SXT for scientific observing.

  13. 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.

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

    DOE PAGES

    Huang, Xiaojing; Miao, Huijie; Nelson, Johanna; ...

    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.

  15. 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.

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

    PubMed Central

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

    2011-01-01

    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. PMID:21547016

  17. Thickness variations along coronal loops observed by the Soft X-ray Telescope on Yohkoh

    NASA Technical Reports Server (NTRS)

    Klimchuk, James A.; Lemen, James R.; Feldman, Uri; Tsuneta, Saku; Uchida, Yutaka

    1992-01-01

    The paper presents preliminary results of an investigation of thickness variations along coronal loops observed with the Yohkoh Soft X-ray Telescope (SXT), using observations from ten loops selected from the SXT data. The quantitative results indicate that coronal X-ray loops do not expand. This contradicts the expectation that, if plasma loops coincide with magnetic loops, many loops must be significantly broader at their tops than at their foot points. Possible interpretations of the obtained results are proposed.

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

    DOE PAGES

    Dakovski, Georgi L.; Heimann, Philip; Holmes, Michael; ...

    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.

  19. 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.

  20. Assessment of surface roughness by use of soft x-ray scattering

    NASA Astrophysics Data System (ADS)

    Meng, Yan-li; Wang, Yong-gang; Chen, Shu-yan; Chen, Bo

    2009-08-01

    A soft x-ray reflectometer with laser produced plasma source has been designed, which can work from wavelength 8nm to 30 nm and has high performance. Using the soft x-ray reflectometer above, the scattering light distribution of silicon and zerodur mirrors which have super-smooth surfaces could be measured at different incidence angle and different wavelength. The measurement when the incidence angle is 2 degree and the wavelength is 11nm has been given in this paper. A surface scattering theory of soft x-ray grazing incidence optics based on linear system theory and an inverse scattering mathematical model is introduced. The vector scattering theory of soft x-ray scattering also is stated in detail. The scattering data are analyzed by both the methods above respectively to give information about the surface profiles. On the other hand, both the two samples are measured by WYKO surface profiler, and the surface roughness of the silicon and zerodur mirror is 1.3 nm and 1.5nm respectively. The calculated results are in quantitative agreement with those measured by WYKO surface profiler, which indicates that soft x-ray scattering is a very useful tool for the evaluation of highly polished surfaces. But there still some difference among the results of different theory and WYKO, and the possible reasons of such difference have been discussed in detail.

  1. 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.

  2. Technological aspects of GEM detector design and assembling for soft x-ray application

    NASA Astrophysics Data System (ADS)

    Kowalska-Strzeciwilk, E.; Chernyshova, M.

    2016-09-01

    Various types of Micro Pattern Gas Detectors (MPGDs) found applications as tracking detectors in high energy particle physics experiments and as well as imaging detectors, especially for soft X-rays. These detectors offer several advantages like high count rate capability, good spatial and energy resolution, low cost and possibility of constructing large area detectors with very small dead area. Construction, like the triple Gas Electron Multiplier (GEM) detector has become a standard detector, which is widely used for different imaging applications. Some examples of such applications are: monitoring the impurity in plasma, imaging system for mapping of some parameters like pigment distributions using X-ray fluorescence technique[1], proton range radiography system for quality assurance in hadron therapy. Measuring of the Soft X-Ray (SXR) radiation of magnetic fusion plasma is a standard way of accessing valuable information, for example, about particle transport and MHD. The paper is focused on the design of GEM based soft Xray radiation detecting system which is under development. It is dedicated to study soft X-ray emission of plasma radiation with focus on tungsten emission lines energy region. The paper presents the designing, construction and assembling of a prototype of two triple-GEM detectors for soft-X ray application on the WEST device.

  3. Ground calibration of the Astro-H (Hitomi) soft x-ray spectrometer

    NASA Astrophysics Data System (ADS)

    Eckart, M. E.; Adams, J. S.; Boyce, K. R.; Brown, G. V.; Chiao, M. P.; Fujimoto, R.; Haas, D.; den Herder, J. W.; Ishisaki, Y.; Kelley, R. L.; Kilbourne, C. A.; Leutenegger, M. A.; McCammon, D.; Mitsuda, K.; Porter, F. S.; Sato, K.; Sawada, M.; Seta, H.; Sneiderman, G. A.; Szymkowiak, A. E.; Takei, Y.; Tashiro, M.; Tsujimoto, M.; de Vries, C. P.; Watanabe, T.; Yamada, S.; Yamasaki, N. Y.

    2016-07-01

    The Astro-H (Hitomi) Soft X-ray Spectrometer (SXS) was a pioneering imaging x-ray spectrometer with 5 eV energy resolution at 6 keV. The instrument used a microcalorimeter array at the focus of a high-throughput soft x-ray telescope to enable high-resolution non-dispersive spectroscopy in the soft x-ray waveband (0:3-12 keV). We present the suite of ground calibration measurements acquired from 2012-2015, including characterization of the detector system, anti-coincidence detector, optical blocking filters, and filter-wheel filters. The calibration of the 36-pixel silicon thermistor microcalorimeter array includes parameterizations of the energy gain scale and line spread function for each event grade over a range of instrument operating conditions, as well as quantum efficiency measurements. The x-ray transmission of the set of five Al/polyimide thin-film optical blocking filters mounted inside the SXS dewar has been modeled based on measurements at synchrotron beamlines, including with high spectral resolution at the C, N, O, and Al K-edges. In addition, we present the x-ray transmission of the dewar gate valve and of the filters mounted on the SXS filter wheel (external to the dewar), including beryllium, polyimide, and neutral density filters.

  4. Progress toward a soft x-ray polarimeter

    NASA Astrophysics Data System (ADS)

    Marshall, Herman L.; Schulz, Norbert S.; Remlinger, Brian; Gentry, Eric S.; Windt, David L.; Gullikson, Eric M.

    2013-09-01

    We are developing instrumentation for a telescope design capable of measuring linear X-ray polarization over a broad-band using conventional spectroscopic optics. Multilayer-coated mirrors are key to this approach, being used as Bragg reflectors at the Brewster angle. By laterally grading the multilayer mirrors and matching to the dispersion of a spectrometer, one may take advantage of high multilayer reflectivities and achieve modulation factors over 50% over the entire 0.2-0.8 keV band. We present progress on laboratory work to demonstrate the capabilities of an existing laterally graded multilayer coated mirror pair. We also present plans for a suborbital rocket experiment designed to detect a polarization level of 12-17% for an active galactic nucleus in the 0.1-1.0 keV band.

  5. 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.

  6. Soft x-ray ionization induced fragmentation of glycine.

    PubMed

    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-Cα bond and the presence of the CNH(2)(+) fragment.

  7. 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.

  8. SOFT CORONAL X-RAYS FROM {beta} PICTORIS

    SciTech Connect

    Guenther, H. M.; Wolk, S. J.; Drake, J. J.; Lisse, C. M.; Robrade, J.; Schmitt, J. H. M. M.

    2012-05-01

    A-type stars are expected to be X-ray dark, yet weak emission has been detected from several objects in this class. We present new Chandra/HRC-I observations of the A5 V star {beta} Pictoris. It is clearly detected with a flux of (9 {+-} 2) Multiplication-Sign 10{sup -4} counts s{sup -1}. In comparison with previous data this constrains the emission mechanism and we find that the most likely explanation is an optically thin, collisionally dominated, thermal emission component with a temperature around 1.1 MK. We interpret this component as a very cool and dim corona, with log L{sub X} /L{sub bol} = -8.2 (0.2-2.0 keV). Thus, it seems that {beta} Pictoris shares more characteristics with cool stars than previously thought.

  9. Quantitative Determination of Absolute Organohalogen Concentrations in Environmental Samples by X-ray Absorption Spectroscopy

    SciTech Connect

    Leri,A.; Hay, M.; Lanzirotti, A.; Rao, W.; Myneni, S.

    2006-01-01

    An in situ procedure for quantifying total organic and inorganic Cl concentrations in environmental samples based on X-ray absorption near-edge structure (XANES) spectroscopy has been developed. Cl 1s XANES spectra reflect contributions from all Cl species present in a sample, providing a definitive measure of total Cl concentration in chemically heterogeneous samples. Spectral features near the Cl K-absorption edge provide detailed information about the bonding state of Cl, whereas the absolute fluorescence intensity of the spectra is directly proportional to total Cl concentration, allowing for simultaneous determination of Cl speciation and concentration in plant, soil, and natural water samples. Absolute Cl concentrations are obtained from Cl 1s XANES spectra using a series of Cl standards in a matrix of uniform bulk density. With the high sensitivity of synchrotron-based X-ray absorption spectroscopy, Cl concentration can be reliably measured down to the 5-10 ppm range in solid and liquid samples. Referencing the characteristic near-edge features of Cl in various model compounds, we can distinguish between inorganic chloride (Cl{sub inorg}) and organochlorine (Cl{sub org}), as well as between aliphatic Cl{sub org} and aromatic Cl{sub org}, with uncertainties in the range of {approx}6%. In addition, total organic and inorganic Br concentrations in sediment samples are quantified using a combination of Br 1s XANES and X-ray fluorescence (XRF) spectroscopy. Br concentration is detected down to {approx}1 ppm by XRF, and Br 1s XANES spectra allow quantification of the Br{sub inorg} and Br{sub org} fractions. These procedures provide nondestructive, element-specific techniques for quantification of Cl and Br concentrations that preclude extensive sample preparation.

  10. Constraining the redshifted 21-cm signal with the unresolved soft X-ray background

    NASA Astrophysics Data System (ADS)

    Fialkov, Anastasia; Cohen, Aviad; Barkana, Rennan; Silk, Joseph

    2017-01-01

    We use the observed unresolved cosmic X-ray background (CXRB) in the 0.5-2 keV band and existing upper limits on the 21-cm power spectrum to constrain the high-redshift population of X-ray sources, focusing on their effect on the thermal history of the Universe and the cosmic 21-cm signal. Because the properties of these sources are poorly constrained, we consider hot gas, X-ray binaries and mini-quasars (i.e. sources with soft or hard X-ray spectra) as possible candidates. We find that (1) the soft-band CXRB sets an upper limit on the X-ray efficiency of sources that existed before the end of reionization, which is one-to-two orders of magnitude higher than typically assumed efficiencies, (2) hard sources are more effective in generating the CXRB than the soft ones, (3) the commonly assumed limit of saturated heating is not valid during the first half of reionization in the case of hard sources, with any allowed value of X-ray efficiency, (4) the maximal allowed X-ray efficiency sets a lower limit on the depth of the absorption trough in the global 21-cm signal and an upper limit on the height of the emission peak, while in the 21-cm power spectrum it sets a minimum amplitude and frequency for the high-redshift peaks, and (5) the existing upper limit on the 21-cm power spectrum sets a lower limit on the X-ray efficiency for each model. When combined with the 21-cm global signal, the CXRB will be useful for breaking degeneracies and helping constrain the nature of high-redshift heating sources.

  11. 3D simulation of the image formation in soft x-ray microscopes.

    PubMed

    Selin, Mårten; Fogelqvist, Emelie; Holmberg, Anders; Guttmann, Peter; Vogt, Ulrich; Hertz, Hans M

    2014-12-15

    In water-window soft x-ray microscopy the studied object is typically larger than the depth of focus and the sample illumination is often partially coherent. This blurs out-of-focus features and may introduce considerable fringing. Understanding the influence of these phenomena on the image formation is therefore important when interpreting experimental data. Here we present a wave-propagation model operating in 3D for simulating the image formation of thick objects in partially coherent soft x-ray microscopes. The model is compared with present simulation methods as well as with experiments. The results show that our model predicts the image formation of transmission soft x-ray microscopes more accurately than previous models.

  12. Wide Field-of-View Soft X-Ray Imaging for Solar Wind-Magnetosphere Interactions

    NASA Technical Reports Server (NTRS)

    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.

    2016-01-01

    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.

  13. 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.

  14. Error analysis of ellipsoidal mirrors for soft X-ray focusing by wave-optical simulation

    NASA Astrophysics Data System (ADS)

    Motoyama, Hiroto; Saito, Takahiro; Mimura, Hidekazu

    2014-02-01

    The ellipsoidal mirror is an ideal soft X-ray focusing optic that enables achromatic and highly efficient focusing to a nanometer spot size; however, a high-quality surface is necessary for ideal focusing. Knowledge of the required figure accuracy is important for fabrication. In this paper, we analyze the effects of figure errors on the focusing performance through wave-optical calculations based on the Fresnel-Kirchhoff diffraction theory, assuming coherent soft X-rays. Figure errors are classified into three types from the viewpoint of manufacturing. The effect of the alignment error is also investigated. The analytical results quantitatively indicate criteria regarding figure accuracy, which are expected to be essential for the development of high-performance ellipsoidal soft X-ray focusing mirrors.

  15. 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.

  16. 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.

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

    NASA Astrophysics Data System (ADS)

    Boissay, R.; Paltani, S.; Ricci, C.

    2015-07-01

    The origin of the soft-excess in many Seyfert 1-1.5s spectra 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 use the fact that these models predict different behaviors in the hard X-rays. Ionized reflection indeed covers a broad energy range, from the soft X-rays to the hard X-rays around a few tens of keV, while Comptonization from a warm plasma drops very quickly above a few keV. 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 PN and MOS 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 and to the photon index of the primary continuum, and show that our results are in contradiction with those obtained from simulations of blurred ionized-reflection models.

  18. A linear motion machine for soft x-ray interferometry

    SciTech Connect

    Duarte, R.; Howells, M.R.; Hussain, Z.; Lauritzen, T.; McGill, R.

    1997-07-01

    A Fourier Transform X-ray Spectrometer has been designed and built for use at the Advanced light source at Lawrence Berkeley National Laboratory. The design requires a total rectilinear motion of 15 mm with a maximum pitch error of the stage below {+-}0.4 {mu}radians, to achieve this the authors chose to build the entire machine as a single monolithic flexure. A hydraulic driver with sliding O-ring seals was developed with the intention to provide motion with a stick-slip position error of less than 0.8 nm at a uniform velocity of 20 {mu}m/sec. The machine is comprised of two pairs of nested linear motion flexures, all explained by means of a theory published earlier by Hathaway. Certain manufacturing errors were successfully corrected by an extra weak-link feature in the monolith frame. The engineering details of all the subsystems of the linear motion machine are described and measured performance reported.

  19. 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.

  20. Soft x-ray resonant magnetic scattering from an imprinted magnetic domain pattern

    SciTech Connect

    Kinane,C.; Suszka, A.; Marrows, C.; Hickey, B.; Arena, D.; Dvorak, J.; Charlton, T.; Langridge, S.

    2006-01-01

    The authors report on the use of a Co/Pt multilayer, which exhibits strong perpendicular magnetic anisotropy, to magnetostatically imprint a domain pattern onto a 50 Angstroms thick Permalloy layer. Element specific soft x-ray magnetic scattering experiments were then performed so as to be sensitive to the magnetic structure of the Permalloy only. Off-specular magnetic satellite peaks, corresponding to a periodic domain stripe width of 270 nm, were observed, confirmed by magnetic force microscopy and micromagnetic modeling. Thus the authors have exploited the element specificity of soft x-ray scattering to discern the purely magnetic correlations in a structurally flat Permalloy film.

  1. 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

  2. Numerical Experiments on Oxygen Plasma Focus: Scaling Laws of Soft X-Ray Yields

    NASA Astrophysics Data System (ADS)

    Akel, M.

    2013-08-01

    Numerical experiments have been investigated on UNU/ICTP PFF low energy plasma focus device with oxygen filling gas. In these numerical experiments, the temperature window of 119-260 eV has been used as a suitable temperature range for generating oxygen soft X-rays. The Lee model was applied to characterize the UNU/ICTP PFF plasma focus. The optimum soft X-ray yield (Ysxr) was found to be 0.75 J, with the corresponding efficiency of about 0.03 % at pressure of 2.36 Torr and the end axial speed was va = 5 cm/μs. The practical optimum combination of p0, z0 and `a' for oxygen Ysxr was found to be 0.69 Torr, 4.8 cm and 2.366 cm respectively, with the outer radius b = 3.2 cm. This combination gives Ysxr ~ 5 J, with the corresponding efficiency of about 0.16 %. Thus we expect to increase the oxygen Ysxr of UNU/ICTP PFF, without changing the capacitor bank, merely by changing the electrode configuration and operating pressure. Scaling laws on oxygen soft X-ray yield, in terms of storage energies E0, peak discharge current Ipeak and focus pinch current Ipinch were found over the range from 1 kJ to 1 MJ. It was found that the oxygen soft X-ray yields scale well with and for the low inductance (L0 = 30 nH) (where yields are in J and currents in kA). While the soft X-ray yield scaling laws in terms of storage energies were found to be as (E0 in kJ and Ysxr in J) with the scaling showing gradual deterioration as E0 rises over the range. The oxygen soft X-ray yield emitted from plasma focus is found to be about 8.7 kJ for storage energy of 1 MJ. The optimum efficiency for soft X-ray yield (1.1 %) is with capacitor bank energy of 120 kJ. This indicates that oxygen plasma focus is a good soft X-ray source when properly designed.

  3. 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

  4. A search for soft X-ray emission from red-giant coronae

    NASA Technical Reports Server (NTRS)

    Margon, B.; Mason, K. O.; Sanford, P. W.

    1974-01-01

    Hills has pointed out that if red-giant coronae are weak sources of soft X-rays, then the problems of the identification of the local component of the soft X-ray background and the observed lack of gas in globular clusters may be simultaneously resolved. Using instrumentation aboard OAO Copernicus, we have searched unsuccessfully for emission in the 10-100 A band from four nearby red giants. In all cases, our upper limits are of the order of the minimum theoretically predicted fluxes.

  5. Explosive Device for Generation of Pulsed Fluxes of Soft X-Ray Radiation

    NASA Astrophysics Data System (ADS)

    Selemir, V. D.; Demidov, V. A.; Ivanovsky, A. V.; Yermolovich, V. F.; Kornilov, V. G.; Chelpanov, V. I.; Kazakov, S. A.; Vlasov, Y. V.; Orlov, A. P.

    2004-11-01

    The concept and realization of the explosive electrophysical device EMIR to generate soft x-ray radiation pulses are described. EMIR is based on the development of VNIIEF technologies in high-power flux compression generators, and on transforming systems based on lines with distributed parameters and current opening switches. Vacuum lines with magnetic insulation or water coaxial lines are considered for transmission of the energy pulses to the load. Transformation of magnetic energy to kinetic energy, thermalization and soft x-ray radiation are performed in a z-pinch with a double liner system.

  6. Experimental demonstration of a soft x-ray self-seeded free-electron laser

    DOE PAGES

    Ratner, D.; Abela, R.; Amann, 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.

  7. 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.

  8. 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

    2015-02-06

    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.

  9. Compact soft x-ray transmission microscopy with sub-50 nm spatial resolution.

    PubMed

    Kim, Kyong Woo; Kwon, Youngman; Nam, Ki-Yong; Lim, Jong-Hyeok; Kim, Kyu-Gyum; Chon, Kwon Su; Kim, Byoung Hoon; Kim, Dong Eon; Kim, JinGon; Ahn, Byoung Nam; Shin, Hyun Joon; Rah, Seungyu; Kim, Ki-Ho; Chae, Jin Seok; Gweon, Dae Gab; Kang, Dong Woo; Kang, Sung Hoon; Min, Jin Young; Choi, Kyu-Sil; Yoon, Seong Eon; Kim, Eun-A; Namba, Yoshiharu; Yoon, Kwon-Ha

    2006-03-21

    In this paper, the development of compact transmission soft x-ray microscopy (XM) with sub-50 nm spatial resolution for biomedical applications is described. The compact transmission soft x-ray microscope operates at lambda = 2.88 nm (430 eV) and is based on a tabletop regenerative x-ray source in combination with a tandem ellipsoidal condenser mirror for sample illumination, an objective micro zone plate and a thinned back-illuminated charge coupled device to record an x-ray image. The new, compact x-ray microscope system requires the fabrication of proper x-ray optical devices in order to obtain high-quality images. For an application-oriented microscope, the alignment procedure is fully automated via computer control through a graphic user interface. In imaging studies using our compact XM system, a gold mesh image was obtained with 45 nm resolution at x580 magnification and 1 min exposure. Images of a biological sample (Coscinodiscus oculoides) were recorded.

  10. Soft X-ray emission in kink-unstable coronal loops

    NASA Astrophysics Data System (ADS)

    Pinto, Rui; Vilmer, Nicole; Brun, Allan Sacha

    Solar flares are associated with intense soft X-ray emission generated by the hot flaring plasma in coronal magnetic loops. We investigate the temporal, spectral and spatial evolution of the properties of the thermal X-ray emission produced in simulated kink-unstable magnetic flux-ropes. The numerical setup used consists of a highly twisted loop embedded in a region of uniform and untwisted background coronal magnetic field. The magnetic flux-rope reconnects with the background flux after the triggering of the kink instability and is then allowed to relax to a lower energy state. Strong ohmic heating leads to strong and quick heating (up to more than 15 MK), to a strong peak of X-ray emission and to the hardening of the thermal X-ray spectrum. The emission pattern is often filamentary and the amount of twist deduced from the X-ray emission alone is considerably lower than the maximum twist in the simulated flux-ropes. The flux-rope plasma becomes strongly multi-thermal during the flaring episode. The emission measure evolves into a bi-modal distribution as a function of temperature during the saturation phase, and later converges to the power-law distribution mathrm{EM}~ T(-4.2) (during the relaxation/cooling) phase. These soft X-ray emission properties are maintained for a large range of coronal magnetic field strength, plasma density and flux-rope twist values.

  11. 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.

  12. 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.

  13. Soft x-ray radiation from laser-produced plasmas: characterization of radiation emission and its use in x-ray lithography.

    PubMed

    Kühne, M; Petzold, H C

    1988-09-15

    Laser pulses of 15 ns and soft x-ray radiation pulses. The plasma generation is described, and the x-ray emission is spectrally and spatially characterized. Using this plasma as an x-ray source, FBM120 resist was exposed through a gold patterned 2-microm silicon mask. Exposing the same resist to a primary standard source (electron storage ring BESSY) the plasma x-ray emission was evaluated resulting in conversion efficiencies (laser into x-ray radiation) of up to 3.4% for 1064 nm and up to 5.0% for 532-nm laser radiation pulses.

  14. 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.

  15. 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.

  16. Versatile soft X-ray-optical cross-correlator for ultrafast applications.

    PubMed

    Schick, Daniel; Eckert, Sebastian; Pontius, Niko; Mitzner, Rolf; Föhlisch, Alexander; Holldack, Karsten; Sorgenfrei, Florian

    2016-09-01

    We present an X-ray-optical cross-correlator for the soft ([Formula: see text]) up to the hard X-ray regime based on a molybdenum-silicon superlattice. The cross-correlation is done by probing intensity and position changes of superlattice Bragg peaks caused by photoexcitation of coherent phonons. This approach is applicable for a wide range of X-ray photon energies as well as for a broad range of excitation wavelengths and requires no external fields or changes of temperature. Moreover, the cross-correlator can be employed on a 10 ps or 100 fs time scale featuring up to 50% total X-ray reflectivity and transient signal changes of more than 20%.

  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.

  18. Prototype high resolution multienergy soft x-ray array for NSTX

    SciTech Connect

    Tritz, K.; Stutman, D.; Finkenthal, M.; Delgado-Aparicio, L.; Kaita, R.; Roquemore, L.

    2010-10-15

    A novel diagnostic design seeks to enhance the capability of multienergy soft x-ray (SXR) detection by using an image intensifier to amplify the signals from a larger set of filtered x-ray profiles. The increased number of profiles and simplified detection system provides a compact diagnostic device for measuring T{sub e} in addition to contributions from density and impurities. A single-energy prototype system has been implemented on NSTX, comprised of a filtered x-ray pinhole camera, which converts the x-rays to visible light using a CsI:Tl phosphor. SXR profiles have been measured in high performance plasmas at frame rates of up to 10 kHz, and comparisons to the toroidally displaced tangential multi-energy SXR have been made.

  19. A sample holder for soft x-ray absorption spectroscopy of liquids in transmission mode.

    PubMed

    Schreck, Simon; Gavrila, Gianina; Weniger, Christian; Wernet, Philippe

    2011-10-01

    A novel sample holder for soft x-ray absorption spectroscopy of liquids in transmission mode based on sample cells with x-ray transparent silicon nitride membranes is introduced. The sample holder allows for a reliable preparation of ultrathin liquid films with an adjustable thickness in the nm-μm range. This enables measurements of high quality x-ray absorption spectra of liquids in transmission mode, as will be shown for the example of liquid H(2)O, aqueous solutions of 3d-transition metal ions and alcohol-water mixtures. The fine structure of the x-ray absorption spectra is not affected by the sample thickness. No effects of the silicon nitride membranes were observed in the spectra. It is shown how an inhomogeneous thickness of the sample affects the spectra and how this can be avoided.

  20. 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.

  1. Versatile soft X-ray-optical cross-correlator for ultrafast applications

    PubMed Central

    Schick, Daniel; Eckert, Sebastian; Pontius, Niko; Mitzner, Rolf; Föhlisch, Alexander; Holldack, Karsten; Sorgenfrei, Florian

    2016-01-01

    We present an X-ray-optical cross-correlator for the soft (>150 eV) up to the hard X-ray regime based on a molybdenum-silicon superlattice. The cross-correlation is done by probing intensity and position changes of superlattice Bragg peaks caused by photoexcitation of coherent phonons. This approach is applicable for a wide range of X-ray photon energies as well as for a broad range of excitation wavelengths and requires no external fields or changes of temperature. Moreover, the cross-correlator can be employed on a 10 ps or 100 fs time scale featuring up to 50% total X-ray reflectivity and transient signal changes of more than 20%. PMID:27795974

  2. Simulation of the fundamental and nonlinear harmonic output from an FEL amplifier with a soft x-ray seed laser

    SciTech Connect

    Biedron, S. G.; Freund, H. P.; Li, Y.; Milton, S. V.

    2000-07-05

    A single-pass, high-gain free-electron laser (FEL) x-ray amplifier was simulated using the 3D, polychromatic simulation code MEDUSA. The seed for the system is a table-top, soft x-ray laser. The simulated fundamental and nonlinear harmonic x-ray output wavelengths are discussed.

  3. Soft x-ray studies of plasma-focus pinch structures in PF-1000U experiments

    NASA Astrophysics Data System (ADS)

    Sadowski, M. J.; Paduch, M.; Skladnik-Sadowska, E.; Surala, W.; Zaloga, D.; Miklaszewski, R.; Zielinska, E.; Tomaszewski, K.

    2015-10-01

    This work reports on recent experiments performed at the modernized PF-1000U plasma-focus facility. In contrast to earlier studies the main attention was focussed on measurements of the soft x-ray emission. Detailed time-integrated x-ray measurements, carried out using filtered pinhole cameras with sensitive x-ray films, are presented and analysed. The fine structure of the collapsing current sheath and dense pinch column is investigated. Observations of ‘plasma filaments’ are discussed and compared with those from the old POSEIDON facility. New results are time-integrated x-ray images of PF-1000U discharges with additional gas puffing, which in many cases show distinct plasma filaments and/or ‘hot spots’ formed inside the dense pinch column. The formation of such ‘hot-spots’ is explained by necking and breaking of the plasma filaments. Results of time-resolved x-ray measurements, performed outside the experimental chamber by means of scintillation probes, and inside with PIN-diodes placed behind pinholes and absorption filters, are also presented Time-resolved measurements, carried out using an old XUV framing-camera and a new soft x-ray four-frame camera (SXRFFC), are also presented and discussed. Correlations of the time-integrated x-ray images (of plasma filaments and hot spots) with time-resolved x-ray signals are discussed. The hypothesis that plasma-current filaments appear in almost all PF-type discharges is supported by pictures of radial erosion tracks on the anode front-plate after many discharges.

  4. 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.

  5. The high-field magnet endstation for X-ray magnetic dichroism experiments at ESRF soft X-ray beamline ID32

    PubMed Central

    Kummer, K.; Fondacaro, A.; Jimenez, E.; Velez-Fort, E.; Amorese, A.; Aspbury, M.; Yakhou-Harris, F.; van der Linden, P.; Brookes, N. B.

    2016-01-01

    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

  6. XMM-Newton observations of the X-ray soft polar QS Telescopii

    NASA Astrophysics Data System (ADS)

    Traulsen, I.; Reinsch, K.; Schwope, A. D.; Burwitz, V.; Dreizler, S.; Schwarz, R.; Walter, F. M.

    2011-05-01

    Context. On the basis of XMM-Newton observations, we investigate the energy balance of selected magnetic cataclysmic variables, which have shown an extreme soft-to-hard X-ray flux ratio in the ROSAT All-Sky Survey. Aims: We intend to establish the X-ray properties of the system components, their flux contributions, and the accretion geometry of the X-ray soft polar QS Tel. In the context of high-resolution X-ray analyses of magnetic cataclysmic variables, this study will contribute to better understanding the accretion processes on magnetic white dwarfs. Methods: During an intermediate high state of accretion of QS Tel, we have obtained 20 ks of XMM-Newton data, corresponding to more than two orbital periods, accompanied by simultaneous optical photometry and phase-resolved spectroscopy. We analyze the multi-wavelength spectra and light curves and compare them to former high- and low-state observations. Results: Soft emission at energies below 2 keV dominates the X-ray light curves. The complex double-peaked maxima are disrupted by a sharp dip in the very soft energy range (0.1-0.5 keV), where the count rate abruptly drops to zero. The EPIC spectra are described by a minimally absorbed black body at 20 eV and two partially absorbed mekal plasma models with temperatures around 0.2 and 3 keV. The black-body-like component arises from one mainly active, soft X-ray bright accretion region nearly facing the mass donor. Parts of the plasma emission might be attributed to the second, virtually inactive pole. High soft-to-hard X-ray flux ratios and hardness ratios demonstrate that the high-energy emission of QS Tel is substantially dominated by its X-ray soft component. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Design and characterization for absolute x-ray spectrometry in the 100-10,000 eV region

    SciTech Connect

    Henke, B.L.

    1986-08-01

    Reviewed here are the design and characterization procedures used in our program for developing absolute x-ray spectrometry in the 100 to 10,000 eV region. Described are the selection and experimental calibration of the x-ray filters, mirror momochromators, crystal/multilayer analyzers, and the photographic (time integrating) and photoelectric (time resolving) position-sensitive detectors. Analytical response functions have been derived that characterize the energy dependence of the mirror and crystal/multilayer reflectivities and of the photographic film and photocathode sensitivities. These response functions permit rapid, small-computer reduction of the experimental spectra to absolute spectra (measured in photons per stearadian from the source for radiative transitions at indicated photon energies). Our x-ray spectrographic systems are being applied to the diagnostics of pulsed, high temperature plasma sources in laser fusion and x-ray laser research. 15 refs., 27 figs.

  13. The use of undulator radiation in VUV and soft x-ray radiometry

    SciTech Connect

    Kincaid, B.M.

    1991-11-01

    A new generation of synchrotron radiation light sources covering the VUV, soft x-ray and hard x-ray and spectral regions is under construction in several countries, designed specifically to use periodic magnetic undulators and low-emittance electron or positron beams to produce high-brightness near-diffraction-limited synchrotron radiation beams. It should be possible to use specially designed undulators and wigglers in the new synchrotron light facilities as tunable narrow band radiometric sources in the VUV and soft x-ray regions. An introduction to the physics of undulator radiation is followed by a discussion of some of the consequences of maximizing source performance, including high beam power, harmonics, optics contamination, and the unusual spectral and angular properties of undulator radiation. The limitations of the presently planned undulators as radiometric sources and the design criteria for a possible radiometry undulator will be discussed.

  14. Comparison of coronal holes observed in soft X-ray and HE I 10830 A spectroheliograms

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Davis, J. M.; Harvey, J. W.

    1983-01-01

    Coronal holes observed in solar soft X-ray images obtained with rocket-borne telescopes during 1974 to 1981 are compared with holes observed on nearly simultaneous 10830 A maps. Hole boundaries are frequently poorly defined, and after 1974 the brightness contrast between the large scale structure and holes appears substantially diminished in both X-rays and 10830 A. Good agreement is found between soft X-rays and 10830 A for large area holes but poor agreement for mid and low latitude small area holes, which are generally of low contrast. These results appear inconsistent with the popular view that the quiet corona is sharply separated into open magnetic field regions consisting of coronal holes and closed field regions consisting of the large scale structure.

  15. 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.

  16. Soft X-ray radiation due to a nanosecond diffuse discharge in atmospheric-pressure air

    NASA Astrophysics Data System (ADS)

    Kostyrya, I. D.; Tarasenko, V. F.

    2010-02-01

    A source of soft X-rays with an effective photon energy of 9 keV and a subnanosecond pulse width is built around a gas diode filled with atmospheric-pressure air and a UAEB-150 generator. A collector placed behind a grounded mesh electrode detects an electron beam and a pulse with positive polarity, the latter being due to an electric field surrounding the mesh. It is shown that the intensity of soft X-rays from the gas-diode-based source depends on the material of a massive potential anode; namely, it grows with an increase in the atomic number of the cathode material. In the case of a tantalum anode, X-ray photons with an effective energy of 9 and 17 keV contribute to the exposure dose.

  17. 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.

  18. Compact high-resolution differential interference contrast soft x-ray microscopy

    SciTech Connect

    Bertilson, Michael C.; Hofsten, Olov von; Lindblom, Magnus; Hertz, Hans M.; Vogt, Ulrich

    2008-02-11

    We demonstrate high-resolution x-ray differential interference contrast (DIC) in a compact soft x-ray microscope. Phase contrast imaging is enabled by the use of a diffractive optical element objective which is matched to the coherence conditions in the microscope setup. The performance of the diffractive optical element objective is evaluated in comparison with a normal zone plate by imaging of a nickel siemens star pattern and linear grating test objects. Images obtained with the DIC optic exhibit typical DIC enhancement in addition to the normal absorption contrast. Contrast transfer functions based on modulation measurements in the obtained images show that the DIC optic gives a significant increase in contrast without reducing the spatial resolution. The phase contrast operation mode now available for our compact soft x-ray microscope will be a useful tool for future studies of samples with low absorption contrast.

  19. Closed source experimental system for soft x-ray spectroscopy of radioactive materials

    SciTech Connect

    Modin, A.; Butorin, S. M.; Vegelius, J.; Olsson, A.; Englund, C.-J.; Andersson, J.; Werme, L.; Nordgren, J.; Kaeaembre, T.; Skarnemark, G.; Burakov, B. E.

    2008-09-15

    An instrumental and experimental setup for soft x-ray spectroscopy meeting the requirements of a closed source for radioactivity is described. The system consists of a vacuum sealed cell containing the sample, mounted on a tubing system to ensure compatibility with most standard manipulators. The soft x rays penetrate a thin x-ray window separating the interior of the cell from the vacuum in the experimental chamber. Our first results for single crystal PuO{sub 2} confirm the feasibility of experiments using the setup. The results are consistent with results of first principles calculations and previously recorded spectra obtained using a standard open source setup. The results show that the closed source experimental system can be used to collect valuable experimental data from radioactive materials.

  20. Soft x-ray response of the x-ray CCD camera directly coated with optical blocking layer

    NASA Astrophysics Data System (ADS)

    Ikeda, S.; Kohmura, T.; Kawai, K.; Kaneko, K.; watanabe, T.; Tsunemi, H.; Hayashida, K.; Anabuki, N.; Nakajima, H.; Ueda, S.; Tsuru, T. G.; Dotani, T.; Ozaki, M.; Matsuta, K.; Fujinaga, T.; Kitamoto, S.; Murakami, H.; Hiraga, J.; Mori, K.; ASTRO-H SXI Team

    2012-03-01

    We have developed the back-illuminated X-ray CCD camera (BI-CCD) to observe Xray in space. The X-ray CCD has a sensitivity not only for in X-ray but also in both Optical and UV light, X-ray CCD has to equip a filter to cut off optical light as well as UV light. The X-ray Imaging Spectrometer (XIS) onboard Suzaku satellite equipped with a thin film (OBF: Optical Blocking Filter) to cut off optical light and UV light. OBF is always in danger tearing by the acousmato or vibration during the launch, and it is difficult to handle on the ground because of its thickness. Instead of OBF, we have newly developed and produced OBL (Optical Blocking Layer), which is directly coating on the X-ray CCD surface.

  1. 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.

  2. 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.

  3. 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.'

  4. Edge multi-energy soft x-ray diagnostic in Experimental Advanced Superconducting Tokamak

    SciTech Connect

    Li, Y. L.; Xu, G. S.; Wan, B. N.; Lan, H.; Liu, Y. L.; Wei, J.; Zhang, W.; Hu, G. H.; Wang, H. Q.; Duan, Y. M.; Zhao, J. L.; Wang, L.; Liu, S. C.; Ye, Y.; Li, J.; Lin, X.; Li, X. L.; Tritz, K.; Zhu, Y. B.

    2015-12-15

    A multi-energy soft x-ray (ME-SXR) diagnostic has been built for electron temperature profile in the edge plasma region in Experimental Advanced Superconducting Tokamak (EAST) after two rounds of campaigns. Originally, five preamplifiers were mounted inside the EAST vacuum vessel chamber attached to five vertically stacked compact diode arrays. A custom mechanical structure was designed to protect the detectors and electronics under constraints of the tangential field of view for plasma edge and the allocation of space. In the next experiment, the mechanical structure was redesigned with a barrel structure to absolutely isolate it from the vacuum vessel. Multiple shielding structures were mounted at the pinhole head to protect the metal foils from lithium coating. The pre-amplifiers were moved to the outside of the vacuum chamber to avoid introducing interference. Twisted copper cooling tube was embedded into the back-shell near the diode to limit the temperature of the preamplifiers and diode arrays during vacuum vessel baking when the temperature reached 150 °C. Electron temperature profiles were reconstructed from ME-SXR measurements using neural networks.

  5. Edge multi-energy soft x-ray diagnostic in Experimental Advanced Superconducting Tokamak

    NASA Astrophysics Data System (ADS)

    Li, Y. L.; Xu, G. S.; Tritz, K.; Zhu, Y. B.; Wan, B. N.; Lan, H.; Liu, Y. L.; Wei, J.; Zhang, W.; Hu, G. H.; Wang, H. Q.; Duan, Y. M.; Zhao, J. L.; Wang, L.; Liu, S. C.; Ye, Y.; Li, J.; Lin, X.; Li, X. L.

    2015-12-01

    A multi-energy soft x-ray (ME-SXR) diagnostic has been built for electron temperature profile in the edge plasma region in Experimental Advanced Superconducting Tokamak (EAST) after two rounds of campaigns. Originally, five preamplifiers were mounted inside the EAST vacuum vessel chamber attached to five vertically stacked compact diode arrays. A custom mechanical structure was designed to protect the detectors and electronics under constraints of the tangential field of view for plasma edge and the allocation of space. In the next experiment, the mechanical structure was redesigned with a barrel structure to absolutely isolate it from the vacuum vessel. Multiple shielding structures were mounted at the pinhole head to protect the metal foils from lithium coating. The pre-amplifiers were moved to the outside of the vacuum chamber to avoid introducing interference. Twisted copper cooling tube was embedded into the back-shell near the diode to limit the temperature of the preamplifiers and diode arrays during vacuum vessel baking when the temperature reached 150 °C. Electron temperature profiles were reconstructed from ME-SXR measurements using neural networks.

  6. Edge multi-energy soft x-ray diagnostic in Experimental Advanced Superconducting Tokamak.

    PubMed

    Li, Y L; Xu, G S; Tritz, K; Zhu, Y B; Wan, B N; Lan, H; Liu, Y L; Wei, J; Zhang, W; Hu, G H; Wang, H Q; Duan, Y M; Zhao, J L; Wang, L; Liu, S C; Ye, Y; Li, J; Lin, X; Li, X L

    2015-12-01

    A multi-energy soft x-ray (ME-SXR) diagnostic has been built for electron temperature profile in the edge plasma region in Experimental Advanced Superconducting Tokamak (EAST) after two rounds of campaigns. Originally, five preamplifiers were mounted inside the EAST vacuum vessel chamber attached to five vertically stacked compact diode arrays. A custom mechanical structure was designed to protect the detectors and electronics under constraints of the tangential field of view for plasma edge and the allocation of space. In the next experiment, the mechanical structure was redesigned with a barrel structure to absolutely isolate it from the vacuum vessel. Multiple shielding structures were mounted at the pinhole head to protect the metal foils from lithium coating. The pre-amplifiers were moved to the outside of the vacuum chamber to avoid introducing interference. Twisted copper cooling tube was embedded into the back-shell near the diode to limit the temperature of the preamplifiers and diode arrays during vacuum vessel baking when the temperature reached 150 °C. Electron temperature profiles were reconstructed from ME-SXR measurements using neural networks.

  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.

  8. A new streaked soft x-ray imager for the National Ignition Facility

    DOE PAGES

    Benstead, J.; Moore, A. S.; Ahmed, M. F.; ...

    2016-05-27

    Here, a new streaked soft x-ray imager has been designed for use on high energy-density (HED) physics experiments at the National Ignition Facility based at the Lawrence Livermore National Laboratory. This streaked imager uses a slit aperture, single shallow angle reflection from a nickel mirror, and soft x-ray filtering to, when coupled to one of the NIF’s x-ray streak cameras, record a 4× magnification, one-dimensional image of an x-ray source with a spatial resolution of less than 90 μm. The energy band pass produced depends upon the filter material used; for the first qualification shots, vanadium and silver-on-titanium filters weremore » used to gate on photon energy ranges of approximately 300–510 eV and 200–400 eV, respectively. A two-channel version of the snout is available for x-ray sources up to 1 mm and a single-channel is available for larger sources up to 3 mm. Both the one and two-channel variants have been qualified on quartz wire and HED physics target shots.« less

  9. A new streaked soft x-ray imager for the National Ignition Facility

    SciTech Connect

    Benstead, J.; Moore, A. S.; Ahmed, M. F.; Morton, J.; Guymer, T. M.; Pardini, T.; Soufli, R.; Hibbard, R. L.; Bailey, C. G.; Bell, P. M.; Hau-Riege, S.; Bedzyk, M.; Shoup, III, M. J.; Reagan, S.; Agliata, T.; Jungquist, R.; Schmidt, D. W.; Kot, L. B.; Garbett, W. J.; Rubbery, M. S.; Skidmore, J. W.; Gullikson, E.; Salmassi, F.

    2016-05-27

    Here, a new streaked soft x-ray imager has been designed for use on high energy-density (HED) physics experiments at the National Ignition Facility based at the Lawrence Livermore National Laboratory. This streaked imager uses a slit aperture, single shallow angle reflection from a nickel mirror, and soft x-ray filtering to, when coupled to one of the NIF’s x-ray streak cameras, record a 4× magnification, one-dimensional image of an x-ray source with a spatial resolution of less than 90 μm. The energy band pass produced depends upon the filter material used; for the first qualification shots, vanadium and silver-on-titanium filters were used to gate on photon energy ranges of approximately 300–510 eV and 200–400 eV, respectively. A two-channel version of the snout is available for x-ray sources up to 1 mm and a single-channel is available for larger sources up to 3 mm. Both the one and two-channel variants have been qualified on quartz wire and HED physics target shots.

  10. A new streaked soft x-ray imager for the National Ignition Facility.

    PubMed

    Benstead, J; Moore, A S; Ahmed, M F; Morton, J; Guymer, T M; Soufli, R; Pardini, T; Hibbard, R L; Bailey, C G; Bell, P M; Hau-Riege, S; Bedzyk, M; Shoup, M J; Reagan, S; Agliata, T; Jungquist, R; Schmidt, D W; Kot, L B; Garbett, W J; Rubery, M S; Skidmore, J W; Gullikson, E; Salmassi, F

    2016-05-01

    A new streaked soft x-ray imager has been designed for use on high energy-density (HED) physics experiments at the National Ignition Facility based at the Lawrence Livermore National Laboratory. This streaked imager uses a slit aperture, single shallow angle reflection from a nickel mirror, and soft x-ray filtering to, when coupled to one of the NIF's x-ray streak cameras, record a 4× magnification, one-dimensional image of an x-ray source with a spatial resolution of less than 90 μm. The energy band pass produced depends upon the filter material used; for the first qualification shots, vanadium and silver-on-titanium filters were used to gate on photon energy ranges of approximately 300-510 eV and 200-400 eV, respectively. A two-channel version of the snout is available for x-ray sources up to 1 mm and a single-channel is available for larger sources up to 3 mm. Both the one and two-channel variants have been qualified on quartz wire and HED physics target shots.

  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.

  12. A Compact Soft X-Ray Microscope using an Electrode-less Z-Pinch Source

    PubMed Central

    Silterra, J; Holber, W

    2009-01-01

    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. PMID:20198115

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

    SciTech Connect

    Ditmire, Todd Raymond

    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:LiSrAlF6 (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 1015 to 1017 W/cm2 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.

  14. 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

  15. Soft X-Ray (1-7 nm) Solar Spectrometer based on novel Nanowriter Electron-Beam Nanofabrication Technology

    NASA Astrophysics Data System (ADS)

    Didkovsky, L. V.; Wieman, S. R.; Chao, W.

    2015-12-01

    A new soft X-ray (SXR) spectrometer combines proven detector technology demonstrated on the SOHO Solar EUV Monitor (SOHO/SEM) and SDO EUV SpectroPhotometer (SDO/EVE/ESP) instruments with novel technology for X-ray optics nanofabrication developed at the Lawrence Berkeley National Laboratory. The new spectrometer will provide solar SXR measurements of absolute irradiance in the 1.0 to 7.0 nm range spectrally resolved into bands narrower than 1 nm - measurements that are not available from existing solar-observing instruments but are important for studying and modeling coronal dynamics and the Sun-Earth's connection, e.g. the Earth's Ionosphere. For the proposed SXR spectrometer we will introduce a transmission grating based on novel Nanowriter Electron-Beam Nanofabrication technology developed at the Center for X-ray Optics (CXRO) at the Lawrence Berkeley National Laboratory. The CXRO technology has been used in the fabrication of X-ray zone plates with feature sizes as small as 25 nm in optical elements with overall sizes on the order of 1 cm. The CXRO technology has significant flexibility in terms of pattern geometry, and is thus capable of producing linear transmission gratings with aperture sizes similar to SEM and ESP but with four times the dispersion. With such dispersion, reasonable spectral resolution (< 1nm) can be obtained using commercial off-the shelf (COTS) X-ray sensitive AXUV type silicon photodiodes from the Optodiode Corp. in an instrument with overall size and mass similar to that of SEM or ESP.

  16. In-flight verification of the calibration and performance of the ASTRO-H (Hitomi) Soft X-Ray Spectrometer

    NASA Astrophysics Data System (ADS)

    Leutenegger, Maurice A.; Audard, Marc; Boyce, Kevin R.; Brown, Gregory V.; Chiao, Meng P.; Eckart, Megan E.; Fujimoto, Ryuichi; Furuzawa, Akihiro; Guainazzi, Matteo; Haas, Daniel; den Herder, Jan-Willem; Hayashi, Takayuki; Iizuka, Ryo; Ishida, Manabu; Ishisaki, Yoshitaka; Kelley, Richard L.; Kikuchi, Naomichi; Kilbourne, Caroline A.; Koyama, Shu; Kurashima, Sho; Maeda, Yoshitomo; Markevitch, Maxim; McCammon, Dan; Mitsuda, Kazuhisa; Mori, Hideyuki; Nakaniwa, Nozomi; Okajima, Takashi; Paltani, Stéphane; Petre, Robert; Porter, F. Scott; Sato, Kosuke; Sato, Toshiki; Sawada, Makoto; Serlemitsos, Peter J.; Seta, Hiromi; Sneiderman, Gary; Soong, Yang; Sugita, Satoshi; Szymkowiak, Andrew E.; Takei, Yoh; Tashiro, Makoto; Tawara, Yuzuru; Tsujimoto, Masahiro; de Vries, Cor P.; Watanabe, Tomomi; Yamada, Shinya; Yamasaki, Noriko

    2016-07-01

    The Soft X-ray Spectrometer (SXS) onboard the Astro-H (Hitomi) orbiting x-ray observatory featured an array of 36 silicon thermistor x-ray calorimeters optimized to perform high spectral resolution x-ray imaging spectroscopy of astrophysical sources in the 0.3-12 keV band. Extensive pre- flight calibration measurements are the basis for our modeling of the pulse-height-energy relation and energy resolution for each pixel and event grade, telescope collecting area, detector efficiency, and pulse arrival time. Because of the early termination of mission operations, we needed to extract the maximum information from observations performed only days into the mission when the onboard calibration sources had not yet been commissioned and the dewar was still coming into thermal equilibrium, so our technique for reconstructing the per-pixel time-dependent pulse-height-energy relation had to be modified. The gain scale was reconstructed using a combination of an absolute energy scale calibration at a single time using a fiducial from an onboard radioactive source, and calibration of a dominant time-dependent gain drift component using a dedicated calibration pixel, as well as a residual time-dependent variation using spectra from the Perseus cluster of galaxies. The energy resolution was also measured using the onboard radioactive sources. It is consistent with instrument-level measurements accounting for the modest increase in noise due to spacecraft systems interference. We use observations of two pulsars to validate our models of the telescope area and detector efficiency, and to derive a more accurate value for the thickness of the gate valve Be window, which had not been opened by the time mission operations ceased. We use observations of the Crab pulsar to refine the pixel-to-pixel timing and validate the absolute timing.

  17. 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.

  18. 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.

  19. Interaction of soft-x-ray thermal radiation with foam-layered targets.

    PubMed

    Batani, D; Desai, T; Löwer, Th; Hall, T A; Nazarov, W; Koenig, M; Benuzzi-Mounaix, A

    2002-06-01

    We have studied the interaction of soft-x-ray thermal radiation with foam-layered metal targets. X-ray radiation was produced by focusing a high-energy laser inside a small size hohlraum. An increment in shock pressure, up to a factor of approximately 4 for 50 mg/cm(3) foam density, was observed with the foam layer as compared to bare metal targets. This follows from the propagation of radiation-driven shock wave in the foam and the impedance mismatch at the foam-payload interface.

  20. 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.

  1. 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.

  2. In situ fine tuning of bendable soft x-ray mirrors using a lateral shearing interferometer

    NASA Astrophysics Data System (ADS)

    Merthe, Daniel J.; Goldberg, Kenneth A.; Yashchuk, Valeriy V.; McKinney, Wayne R.; Celestre, Richard; Mochi, Iacopo; MacDougall, James; Morrison, Gregory Y.; Rekawa, Senajith B.; Anderson, Erik; Smith, Brian V.; Domning, Edward E.; Padmore, Howard

    2013-05-01

    Broadly applicable, in situ at-wavelength metrology methods for x-ray optics are currently under development at the Advanced Light Source. We demonstrate the use of quantitative wavefront feedback from a lateral shearing interferometer for the suppression of aberrations. With the high sensitivity provided by the interferometer we were able to optimally tune the bending couples of a single elliptical mirror (NA=2.7 mrad) in order to focus a beam of soft x-rays (1.24 keV) to a nearly diffraction-limited beam waist size of 156(±10) nm.

  3. Revealing the electronic structure of LiC6 by soft X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Li, X.; Augustsson, A.; Lee, C. M.; Rubensson, J.-E.; Nordgren, J.; Ross, P. N.; Guo, J.-H.

    2017-03-01

    The electronic structure of LiC6 has been investigated by soft X-ray absorption and emission spectroscopies. The results reveal that upon full lithiation of graphite, the Li 2s electrons are transferred into the carbon π* states in a near rigid-band behavior, resulting in the increased density of states near EF and the shift of σ* states to lower energies. In addition, the resonant inelastic X-ray scattering spectra of LiC6 do not show strong dispersive features as that of graphite, indicating that the crystal momentum is not conserved during the scattering process due to the delocalization of electrons in the intermediate state.

  4. Structural mechanics of the solar-A Soft X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Jurcevich, B. K.; Bruner, M. E.; Gowen, K. F.

    1992-01-01

    The Soft X-ray Telescope (SXT) is one of four major instruments that constitute the payload of the NASA-Japanese mission YOHKOH (formerly known as Solar-A), scheduled to be launched in August, 1991. This paper describes the design of the SXT, the key system requirements, and the SXT optical and structural systems. Particular attention is given to the design considerations for stiffness and dimensional stability, temperature compensation, and moisture sensitivyty control. Consideration is also given to the X-ray mirror, the aspect telescope, the entrance filters, the mechanical structure design, the aft support plate and mount, the SXT finite element model, and other subsystems.

  5. Condenser optics, partial coherence, and imaging for soft-x-ray projection lithography.

    PubMed

    Sommargren, G E; Seppala, L G

    1993-12-01

    A condenser system couples the radiation source to an imaging system, controlling the uniformity and partial coherence at the object, which ultimately affects the characteristics of the aerial image. A soft-x-ray projection lithography system based on a ring-field imaging system and a laser-produced plasma x-ray source places considerable constraints on the design of a condenser system. Two designs are proposed, critical illumination and Köhler illumination, each of which requires three mirrors and scanning for covering the entire ring field with the required uniformity and partial coherence. Images based on Hopkins' formulation of partially coherent imaging are simulated.

  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. A search for coronal soft X-ray emission from cool stars with HEAO 1

    NASA Technical Reports Server (NTRS)

    Ayres, T. R.; Garmire, G.; Cordova, F.; Linsky, J. L.

    1979-01-01

    A search of the HEAO 1 A-2 experiment all-sky survey for coronal soft X-ray emission from a sample of active chromosphere G-M stars including six dwarfs, eight giants, four supergiants, and 10 dMe flare stars is summarized. Point sources were detected near the positions of several of the stars considered. However, of these, only the flare stars BY Draconis (dM0e) and AD Leonis (dM3.5e) appear to be likely candidates for the detected X-rays.

  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. 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.

  10. Yields of strand breaks and base lesions induced by soft X-rays in plasmid DNA.

    PubMed

    Yokoya, A; Fujii, K; Ushigome, T; Shikazono, N; Urushibara, A; Watanabe, R

    2006-01-01

    The yields of soft-X-ray-induced DNA damages have been measured by using closed-circular plasmid DNA. Several DNA solutions with three kinds of radical scavenger capacity and also fully hydrated DNA samples were irradiated to compare the contribution by indirect reaction of diffusible water radicals, such as OH*, with those by direct action of secondary electrons. The yields of prompt single- (SSBs) and double-strand breaks (DSBs) decrease with increasing scavenging capacity. The SSB yields for soft X-rays are approximately midway those between gamma-ray and ultrasoft X-ray data previously reported. Heat labile sites are observed only in the low scavenger condition. The yields of the base lesions revealed by post irradiation treatment with base excision repair enzymes showed a similar value for Nth and Fpg protein except in the hydrated sample. These results indicate that the direct effect of soft X-rays induces the damages with different efficiency from those by indirect effect.

  11. 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.

  12. 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.

  13. Conception and realization of a parallel-plate free-air ionization chamber for the absolute dosimetry of an ultrasoft X-ray beam

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    We report the design of a millimeter-sized parallel plate free-air ionization chamber (IC) aimed at determining the absolute air kerma rate of an ultra-soft X-ray beam (E = 1.5 keV). The size of the IC was determined so that the measurement volume satisfies the condition of charged-particle equilibrium. The correction factors necessary to properly measure the absolute kerma using the IC have been established. Particular attention was given to the determination of the effective mean energy for the 1.5 keV photons using the PENELOPE code. Other correction factors were determined by means of computer simulation (COMSOL™and FLUKA). Measurements of air kerma rates under specific operating parameters of the lab-bench X-ray source have been performed at various distances from that source and compared to Monte Carlo calculations. We show that the developed ionization chamber makes it possible to determine accurate photon fluence rates in routine work and will constitute substantial time-savings for future radiobiological experiments based on the use of ultra-soft X-rays.

  14. Conception and realization of a parallel-plate free-air ionization chamber for the absolute dosimetry of an ultrasoft X-ray beam

    SciTech Connect

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

    2014-08-15

    We report the design of a millimeter-sized parallel plate free-air ionization chamber (IC) aimed at determining the absolute air kerma rate of an ultra-soft X-ray beam (E = 1.5 keV). The size of the IC was determined so that the measurement volume satisfies the condition of charged-particle equilibrium. The correction factors necessary to properly measure the absolute kerma using the IC have been established. Particular attention was given to the determination of the effective mean energy for the 1.5 keV photons using the PENELOPE code. Other correction factors were determined by means of computer simulation (COMSOL™and FLUKA). Measurements of air kerma rates under specific operating parameters of the lab-bench X-ray source have been performed at various distances from that source and compared to Monte Carlo calculations. We show that the developed ionization chamber makes it possible to determine accurate photon fluence rates in routine work and will constitute substantial time-savings for future radiobiological experiments based on the use of ultra-soft X-rays.

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

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

  16. Absolute x-ray dosimetry on a synchrotron medical beam line with a graphite calorimeter

    SciTech Connect

    Harty, P. D. Ramanathan, G.; Butler, D. J.; Johnston, P. N.; Lye, J. E.; Hall, C. J.; Stevenson, A. W.

    2014-05-15

    Purpose: The absolute dose rate of the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron was measured with a graphite calorimeter. The calorimetry results were compared to measurements from the existing free-air chamber, to provide a robust determination of the absolute dose in the synchrotron beam and provide confidence in the first implementation of a graphite calorimeter on a synchrotron medical beam line. Methods: The graphite calorimeter has a core which rises in temperature when irradiated by the beam. A collimated x-ray beam from the synchrotron with well-defined edges was used to partially irradiate the core. Two filtration sets were used, one corresponding to an average beam energy of about 80 keV, with dose rate about 50 Gy/s, and the second filtration set corresponding to average beam energy of 90 keV, with dose rate about 20 Gy/s. The temperature rise from this beam was measured by a calibrated thermistor embedded in the core which was then converted to absorbed dose to graphite by multiplying the rise in temperature by the specific heat capacity for graphite and the ratio of cross-sectional areas of the core and beam. Conversion of the measured absorbed dose to graphite to absorbed dose to water was achieved using Monte Carlo calculations with the EGSnrc code. The air kerma measurements from the free-air chamber were converted to absorbed dose to water using the AAPM TG-61 protocol. Results: Absolute measurements of the IMBL dose rate were made using the graphite calorimeter and compared to measurements with the free-air chamber. The measurements were at three different depths in graphite and two different filtrations. The calorimetry measurements at depths in graphite show agreement within 1% with free-air chamber measurements, when converted to absorbed dose to water. The calorimetry at the surface and free-air chamber results show agreement of order 3% when converted to absorbed dose to water. The combined standard uncertainty is 3

  17. 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.

  18. Measurements of absolute M-subshell X-ray production cross sections of Th by electron impact

    NASA Astrophysics Data System (ADS)

    Moy, A.; Merlet, C.; Dugne, O.

    2014-08-01

    Measurements of absolute M-subshell X-ray production cross sections for element Th were made by electron impact for energies ranging from the ionization threshold up to 38 keV. Experimental data were obtained by measuring the X-ray intensity emitted from ultrathin Th films deposited onto self-supporting C backing films. The measurements were conducted with an electron microprobe using high-resolution wavelength dispersive spectrometers. Recorded intensities were converted into absolute X-ray production cross sections by means of atomic data and estimation of the number of primary electrons, target thickness, and detector efficiency. Our experimental X-ray production cross sections, the first to be reported for the M subshells of Th, are compared with X-ray production cross sections calculated with the mean of ionization cross sections obtained from the distorted-wave Born approximation. The Mα X-ray production cross section calculated is in excellent agreement with the measurements, allowing future use for standardless quantification in electron probe microanalysis.

  19. 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).

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

    PubMed

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

    2014-06-10

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

  1. 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 }).

  2. 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

  3. Photospheric soft X-ray emission from hot DA white dwarfs

    NASA Technical Reports Server (NTRS)

    Wesemael, F.; Raymond, J. C.; Kahn, S. M.; Liebert, J.; Steiner, J. E.; Shipman, H. L.

    1984-01-01

    The Einstein Observatory's imaging proportional counter has detected 150-eV soft X-ray radiation from the four hot DA white dwarfs EG 187, Gr 288 and 289, and LB 1663. The observed pulse height spectra suggest that the emission is generated by hot photospheres whose T(eff) lie in the 30,000-60,000 K range. The IUE spacecraft UV spectra and H-beta line profiles for the four stars have been fitted, along with the X-ray fluxes, with a grid of hot, high gravity, homogeneous model atmospheres of mixed H-He composition. In all cases, the data require the presence of some X-ray opacity in the photosphere. Attention is given to the implications of this result in the context of white dwarf surface layer diffusion theories. Also noted are the limits imposed on the hot white dwarf population by the Einstein Medium Sensitivity Survey.

  4. 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.

  5. Construction of focusing soft x-ray beamline BL1A at the UVSOR

    SciTech Connect

    Hiraya, A.; Horigome, T.; Okada, N.; Mizutani, N.; Sakai, K.; Matsudo, O.; Hasumoto, M. ); Fukui, K. ); Watanabe, M. )

    1992-01-01

    A focusing soft x-ray beam line equipped with a focusing premirror and a double crystal monochromator (DXM) has been constructed at BL1A in the UVSOR. An elliptically bent cylindrical mirror was used as the focusing premirror in order to attain both horizontal and vertical focusing at the sample position. Ray tracing shows that the size and shape of the focused spot at sample position with an elliptically bent cylindrical mirror is almost the same as that of an ellipsoidal mirror. Measured spot size of the monochromatic x-ray beam at the sample position was about 2 mm wide and 1 mm high, which is in good agreement with the result of ray tracing. Monochromatic x rays were observed up to 4 keV even after reflection by a platinum coated premirror with grazing angle of 1{degree}.

  6. Supercrystallization of KCl from solution irradiated by soft X-rays

    NASA Astrophysics Data System (ADS)

    Janavičius, A. J.; Rinkūnas, R.; Purlys, R.

    2016-10-01

    The X-rays influence on KCl crystallization in a saturated water solution has been investigated for the aim of comparing it with previously considered NaCl crystallization. The rate of crystallization has been measured in the drying drop in the solution activated by the irradiation. We have measured the influence of the irradiation time of the solution on the rates of KCl crystallization as well as the beginning of the crystallization processes on drying drops. For a longer irradiation time of the solution early crystallization in the drops occurs. A saturated water solution of KCl was irradiated with the diffractometer DRON-3M (Russian device) and this had a great influence on the two-step processes of crystallization. The ionization of the solution by soft X-rays can produce ions, metastable radicals in water, excited crystals' seeds and vacancies in growing crystals by Auger's effect. The X-rays generate a very fast crystallization in the drying drop.

  7. Soft X-ray spectroscopy of transition metal compounds: a theoretical perspective

    NASA Astrophysics Data System (ADS)

    Bokarev, S. I.; Hilal, R.; Aziz, S. G.; Kühn, O.

    2016-12-01

    To date, X-ray spectroscopy has become a routine tool that can reveal highly local and element-specific information on the electronic structure of atoms in complex environments. Here, we report on the development of an efficient and versatile theoretical methodology for the treatment of soft X-ray spectra of transition metal compounds based on the multi-configurational self-consistent field electronic structure theory. A special focus is put on the L-edge photon-in/photon-out and photon-in/electron-out processes, i.e. X-ray absorption, resonant inelastic scattering, partial fluorescence yield, and photoelectron spectroscopy, all treated on the same theoretical footing. The investigated systems range from small prototypical coordination compounds and catalysts to aggregates of biomolecules.

  8. 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.

  9. Time-resolved soft x-ray spectra from laser-produced Cu plasma

    SciTech Connect

    Cone, K V; Dunn, J; Baldis, H A; May, M J; Purvis, M A; Scott, H A; Schneider, M B

    2012-05-02

    The volumetric heating of a thin copper target has been studied with time resolved x-ray spectroscopy. The copper target was heated from a plasma produced using the Lawrence Livermore National Laboratory's Compact Multipulse Terrawatt (COMET) laser. A variable spaced grating spectrometer coupled to an x-ray streak camera measured soft x-ray emission (800-1550 eV) from the back of the copper target to characterize the bulk heating of the target. Radiation hydrodynamic simulations were modeled in 2-dimensions using the HYDRA code. The target conditions calculated by HYDRA were post-processed with the atomic kinetics code CRETIN to generate synthetic emission spectra. A comparison between the experimental and simulated spectra indicates the presence of specific ionization states of copper and the corresponding electron temperatures and ion densities throughout the laser-heated copper target.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. The soft x-ray properties of a complete sample of optically selected quasars. 1: First results

    NASA Technical Reports Server (NTRS)

    Laor, Ari; Fiore, Fabrizio; Elvis, Martin; Wilkes, Belinda J.; Mcdowell, Jonathan C.

    1994-01-01

    We present the results of ROSAT position sensitive proportional counter (PSPC) observations of 10 quasars. These objects are part of our ROSAT program to observe a complete sample of optically selected quasars. This sample includes all 23 quasars from the bright quasar survey with a redshift z less than or = 0.400 and a Galactic H I column density N(sup Gal sub H I) less than 1.9 x 10(exp 20)/sq cm. These selection criteria, combined with the high sensitivity and improved energy resolution of the PSPC, allow us to determine the soft (approximately 0.2-2 keV) X-ray spectra of quasars with about an order of magnitude higher precision compared with earlier soft X-ray observations. The following main results are obtained: Strong correlations are suggested between the soft X-ray spectral slope alpha(sub x) and the following emission line parameters: H beta Full Width at Half Maximum (FWHM), L(sub O III), and the Fe II/H beta flux ratio. These correlations imply the following: (1) The quasar's environment is likely to be optically thin down to approximately 0.2 keV. (2) In most objects alpha(sub x) varies by less than approximately 10% on timescales shorter than a few years. (3) alpha(sub x) might be a useful absolute luminosity indicator in quasars. (4) The Galactic He I and H I column densities are well correlated. Most spectra are well characterized by a simple power law, with no evidence for either significant absorption excess or emission excess at low energies, to within approximately 30%. We find mean value of alpha(sub x) = -1.50 +/- 0.40, which is consistent with other ROSAT observations of quasars. However, this average is significantly steeper than suggested by earlier soft X-ray observations of the Einstein IPC. The 0.3 keV flux in our sample can be predicted to better than a factor of 2 once the 1.69 micrometer(s) flux is given. This implies that the X-ray variability power spectra of quasars flattens out between f approximately 10(exp -5) and f

  17. Absolute x-ray energy calibration over a wide energy range using a diffraction-based iterative method.

    PubMed

    Hong, Xinguo; Chen, Zhiqiang; Duffy, Thomas S

    2012-06-01

    In this paper, we report a method of precise and fast absolute x-ray energy calibration over a wide energy range using an iterative x-ray diffraction based method. Although accurate x-ray energy calibration is indispensable for x-ray energy-sensitive scattering and diffraction experiments, there is still a lack of effective methods to precisely calibrate energy over a wide range, especially when normal transmission monitoring is not an option and complicated micro-focusing optics are fixed in place. It is found that by using an iterative algorithm the x-ray energy is only tied to the relative offset of sample-to-detector distance, which can be readily varied with high precision of the order of 10(-5) -10(-6) spatial resolution using gauge blocks. Even starting with arbitrary initial values of 0.1 Å, 0.3 Å, and 0.4 Å, the iteration process converges to a value within 3.5 eV for 31.122 keV x-rays after three iterations. Different common diffraction standards CeO(2), Au, and Si show an energy deviation of 14 eV. As an application, the proposed method has been applied to determine the energy-sensitive first sharp diffraction peak of network forming GeO(2) glass at high pressure, exhibiting a distinct behavior in the pressure range of 2-4 GPa. Another application presented is pair distribution function measurement using calibrated high-energy x-rays at 82.273 keV. Unlike the traditional x-ray absorption-based calibration method, the proposed approach does not rely on any edges of specific elements, and is applicable to the hard x-ray region where no appropriate absorption edge is available.

  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. 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.

  1. A soft X-ray flare in the Seyfert I galaxy Markarian 335

    NASA Technical Reports Server (NTRS)

    Lee, M. G.; Balick, Bruce; Halpern, J. P.; Heckman, T. M.

    1988-01-01

    Strong, erratic, and primarily soft X-ray flux variations observed in Mrk 335 with the Einstein high-resolution imager (HRI) and monitor proportional counter (MPC) are reported. The variability time scales lie from about 6000 s to the period of observation, 60,000 s. The variability consisted of a decrease followed by an increase at X-ray energies below 2-3 keV. The variability is most pronounced at the softest energies. The X-ray spectrum was harder before the flare than afterward, even after the flare had ended. Averaged over the time of the observations, the MPC data are well-fitted by a power-law spectrum with a spectral index of 1.25 + or - 0.19 with no evidence of absorption by foreground neutral hydrogen at energies above 1.2 keV. If the observed value of the Galactic H I column density is assumed, then the HRI observations require the existence of an additional soft and variable X-ray component.

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

    PubMed

    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

    2015-12-04

    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. 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.

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

    DOE PAGES

    Popmintchev, Dimitar; Hernandez-Garcia, Carlos; Dollar, Franklin; ...

    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

  4. 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.

  5. Report on the workshop on new directions in soft x-ray near-threshold phenomena

    SciTech Connect

    Lindle, D.W.; Perera, R.C.C.

    1988-07-01

    The ''Workshop on New Directions in Soft X-Ray Near-Threshold Phenomena'' was held at the Asilomar Conference Center in Pacific Grove, CA on March 1--4, 1987. It was attended by 59 scientists from 8 countries, representing 27 institutions. Major funding for the meeting was donated by L-Division of the Lawrence Livermore National Laboratory, who hosted and organized two previous workshops on photoabsorption and scattering in the soft x-ray energy range. Additional funding was provided by the User's Group of the Advanced Light Source. The Workshop, as its name suggests, emphasized physical phenomena in atoms, molecules, and solids near inner-shell thresholds. Of particular interest were threshold ionization, post-collisional interaction, resonant photoemission and fluorescence, and multi-electron effects such as shake-up and shake-off. In these areas and others, special consideration was given to presenting recent discoveries and potential ''new directions'' for future work.

  6. 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

  7. High average power, highly brilliant laser-produced plasma source for soft X-ray spectroscopy.

    PubMed

    Mantouvalou, Ioanna; Witte, Katharina; Grötzsch, Daniel; Neitzel, Michael; Günther, Sabrina; Baumann, Jonas; Jung, Robert; Stiel, Holger; Kanngiesser, Birgit; Sandner, Wolfgang

    2015-03-01

    In this work, a novel laser-produced plasma source is presented which delivers pulsed broadband soft X-radiation in the range between 100 and 1200 eV. The source was designed in view of long operating hours, high stability, and cost effectiveness. It relies on a rotating and translating metal target and achieves high stability through an on-line monitoring device using a four quadrant extreme ultraviolet diode in a pinhole camera arrangement. The source can be operated with three different laser pulse durations and various target materials and is equipped with two beamlines for simultaneous experiments. Characterization measurements are presented with special emphasis on the source position and emission stability of the source. As a first application, a near edge X-ray absorption fine structure measurement on a thin polyimide foil shows the potential of the source for soft X-ray spectroscopy.

  8. 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.

  9. Fresnel diffraction correction by phase-considered iteration procedure in soft X-ray projection microscopy

    NASA Astrophysics Data System (ADS)

    Shiina, Tatsuo; Suzuki, Tsuyoshi; Honda, Toshio; Ito, Atsushi; Kinjo, Yasuhito; Yoshimura, Hideyuki; Yada, Keiji; Shinohara, Kunio

    2009-09-01

    In soft X-ray projection microscopy, it is easy to alter the magnification by changing the distance between the pinhole and the specimen, while the image is blurred because the soft X-rays are diffracted through the propagation from specimen to CCD detector. We corrected the blurred image by the iteration procedure of Fresnel to inverse Fresnel transformation taking phase distribution of the specimen into account. The experiments were conducted at the BL-11A of the Photon Factory, KEK, Japan for the specimens such as glass-capillaries, latex-particles, dried mammalian cells and human chromosomes. Many of those blurred images were corrected adequately by the iteration procedure, though some images such as those which have high-contrast or are overlapped by small cells still remain to be improved.

  10. 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.

  11. New soft X-ray beamline BL07LSU at SPring-8

    PubMed Central

    Yamamoto, Susumu; Senba, Yasunori; Tanaka, Takashi; Ohashi, Haruhiko; Hirono, Toko; Kimura, Hiroaki; Fujisawa, Masami; Miyawaki, Jun; Harasawa, Ayumi; Seike, Takamitsu; Takahashi, Sunao; Nariyama, Nobuteru; Matsushita, Tomohiro; Takeuchi, Masao; Ohata, Toru; Furukawa, Yukito; Takeshita, Kunikazu; Goto, Shunji; Harada, Yoshihisa; Shin, Shik; Kitamura, Hideo; Kakizaki, Akito; Oshima, Masaharu; Matsuda, Iwao

    2014-01-01

    A new soft X-ray beamline, BL07LSU, has been constructed at SPring-8 to perform advanced soft X-ray spectroscopy for materials science. The beamline is designed to achieve high energy resolution (E/ΔE> 10000) and high photon flux [>1012 photons s−1 (0.01% bandwidth)−1] in the photon energy range 250–2000 eV with controllable polarization. To realise this state-of-the-art performance, a novel segmented cross undulator was developed and adopted as a light source. The details of the undulator light source and beamline monochromator design are described. The achieved performance of the beamline, such as the photon flux, energy resolution and the state of polarization, is reported. PMID:24562556

  12. 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.

  13. Soft X-ray emissions, meter-wavelength radio bursts, and particle acceleration in solar flares

    NASA Astrophysics Data System (ADS)

    Cane, H. V.; Reames, D. V.

    1988-02-01

    A detailed study of the relationship between metric radio bursts and soft X-ray flares has been made using an extensive data set covering 15 yr. It is found that type IV emission is mainly associated with long-duration 1-8 A events that are known to be well associated with coronal mass ejections. In contrast, type II and type III bursts originate primarily in impulsive soft X-ray events that are not necessarily accompanied by mass ejection. Strong type III bursts, in particular, appear to occur only in association with relatively impulsive flares. It is suggested that coronal shocks responsible for type II bursts are blast waves generated in impulsive energy releases.

  14. Soft X-ray images of the solar corona using normal incidence optics

    NASA Technical Reports Server (NTRS)

    Bruner, M. E.; Haisch, B. M.; Brown, W. A.; Acton, L. W.; Underwood, J. H.

    1988-01-01

    A solar coronal loop system has been photographed in soft X-rays using a normal incidence telescope based on multilayer mirror technology. The telescope consisted of a spherical objective mirror of 4 cm aperture and 1 m focal length, a film cassette, and a focal plane shutter. A metallized thin plastic film filter was used to exclude visible light. The objective mirror was covered with a multilayer coating consisting of alternating layers of tungsten and carbon whose combined thicknesses satisfied the Bragg diffraction condition for 44 A radiation. The image was recorded during a rocket flight on October 25, 1985 and was dominated by emission lines arising from the Si XII spectrum. The rocket also carried a high resolution soft X-ray spectrograph that confirmed the presence of Si XII line radiation in the source. This image represents the first successful use of multilayer technology for astrophysical observations.

  15. High average power, highly brilliant laser-produced plasma source for soft X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Mantouvalou, Ioanna; Witte, Katharina; Grötzsch, Daniel; Neitzel, Michael; Günther, Sabrina; Baumann, Jonas; Jung, Robert; Stiel, Holger; Kanngießer, Birgit; Sandner, Wolfgang

    2015-03-01

    In this work, a novel laser-produced plasma source is presented which delivers pulsed broadband soft X-radiation in the range between 100 and 1200 eV. The source was designed in view of long operating hours, high stability, and cost effectiveness. It relies on a rotating and translating metal target and achieves high stability through an on-line monitoring device using a four quadrant extreme ultraviolet diode in a pinhole camera arrangement. The source can be operated with three different laser pulse durations and various target materials and is equipped with two beamlines for simultaneous experiments. Characterization measurements are presented with special emphasis on the source position and emission stability of the source. As a first application, a near edge X-ray absorption fine structure measurement on a thin polyimide foil shows the potential of the source for soft X-ray spectroscopy.

  16. Soft x-ray measurement of internal tearing mode structure in a reversed-field pinch

    SciTech Connect

    Chartas, G.; Hokin, S.

    1991-09-16

    The structure of internally resonant tearing modes has been studied in the Madison Symmetric Torus reversed-field pinch with a soft x-ray detector system consisting of an imaging array at one toroidal location and several detectors at different toroidal locations. The toroidal mode numbers of m = 1 structures are in the range n = {minus}5, {minus}6, {minus}7. The modes propagate with phase velocity v = 1--6 {times} 10{sup 6} cm/s, larger than the diamagnetic drift velocity v{sub d} {approximately} 5 {times} 10{sup 5} cm/s. Phase locking between modes with different n in manifested as a beating of soft x-ray signals which is found to be strongest near the resonant surfaces of the modes (r/a = 0.1 -- 0.5). 15 refs., 5 figs.

  17. High average power, highly brilliant laser-produced plasma source for soft X-ray spectroscopy

    SciTech Connect

    Mantouvalou, Ioanna; Grötzsch, Daniel; Neitzel, Michael; Günther, Sabrina; Baumann, Jonas; Kanngießer, Birgit; Witte, Katharina; Jung, Robert; Stiel, Holger; Sandner, Wolfgang

    2015-03-15

    In this work, a novel laser-produced plasma source is presented which delivers pulsed broadband soft X-radiation in the range between 100 and 1200 eV. The source was designed in view of long operating hours, high stability, and cost effectiveness. It relies on a rotating and translating metal target and achieves high stability through an on-line monitoring device using a four quadrant extreme ultraviolet diode in a pinhole camera arrangement. The source can be operated with three different laser pulse durations and various target materials and is equipped with two beamlines for simultaneous experiments. Characterization measurements are presented with special emphasis on the source position and emission stability of the source. As a first application, a near edge X-ray absorption fine structure measurement on a thin polyimide foil shows the potential of the source for soft X-ray spectroscopy.

  18. Resolving new ultrastructural features of cytokinetic abscission with soft-X-ray cryo-tomography

    PubMed Central

    Sherman, Shachar; Kirchenbuechler, David; Nachmias, Dikla; Tamir, Adi; Werner, Stephan; Elbaum, Michael; Elia, Natalie

    2016-01-01

    Mammalian cytokinetic abscission is mediated by the ESCRT membrane fission machinery. While much has been clarified on the topology and kinetics of abscission through high-resolution microscopy, key questions regarding the mechanism of abscission remain open. Here we apply cryogenic soft-X-ray tomography to elucidate new ultrastructural details in the intercellular membrane bridge connecting cells undergoing abscission. In particular, we resolve defined ring-like structures inside the midbody dark zone that have been inaccessible to EM, and identify membrane extrusions at the abscission sites. In cells at late stages of abscission we resolve a complex array of helical spirals, extending the structural information obtained by EM. Our results highlight the advantages of soft-X-ray tomography and emphasize the importance of using complementary approaches for characterizing cellular structures. Notably, by providing new structural data from intact cells we present a realistic view on the topology of abscission and suggest new mechanistic models for ESCRT mediated abscission. PMID:27282220

  19. Fast-switching elliptically polarized soft X-ray beamline X13A at NSLS

    NASA Astrophysics Data System (ADS)

    Sánchez-Hanke, C.; Kao, C.-C.; Hulbert, S. L.

    2009-09-01

    The X13A beamline at NSLS is dedicated to the generation and uses of fast-switching elliptically polarized soft X-ray radiation in the energy range from 250 to ~1600 eV. The source for this beamline is an elliptically polarized wiggler (EPW) that delivers linearly elliptically polarized soft X-rays at a switching rate, between right- and left-handed polarization, up to 100 Hz. The optical design is a spherical grating monochromator (SGM) that focuses and diffracts in plane orthogonal to the polarization switching direction. The X13A beamline scientific program is dedicated to spectroscopy and scattering studies of magnetism and magnetic materials. The fast-switching capability of the EPW enables the use of lock-in techniques, thereby greatly enhancing the detection sensitivity for small polarization-dependent signals.

  20. Fast-switching elliptically polarized soft X-ray beam X13A at NSLS

    SciTech Connect

    Sanchez-Hanke, C.; Kao, C.; Hulbert, S.

    2009-07-21

    The X13A beamline at NSLS is dedicated to the generation and uses of fast-switching elliptically polarized soft X-ray radiation in the energy range from 250 to {approx}1600 eV. The source for this beamline is an elliptically polarized wiggler (EPW) that delivers linearly elliptically polarized soft X-rays at a switching rate, between right- and left-handed polarization, up to 100 Hz. The optical design is a spherical grating monochromator (SGM) that focuses and diffracts in plane orthogonal to the polarization switching direction. The X13A beamline scientific program is dedicated to spectroscopy and scattering studies of magnetism and magnetic materials. The fast-switching capability of the EPW enables the use of lock-in techniques, thereby greatly enhancing the detection sensitivity for small polarization-dependent signals.

  1. Soft x-ray spectroscopy undulator beamline at the Advanced Photon Source

    SciTech Connect

    Randall, K.J.; Xu, Z.; Moore, J.F.; Gluskin, E.

    1997-09-01

    Construction of the high-resolution soft x ray spectroscopy undulator beamline, 2ID-C, at the Advanced Photon Source (APS) has been completed. The beamline, one of two soft x ray beamlines at the APS, will cover the photon energy range from 500 to 3,000 eV, with a maximum resolving power between 7,000 and 14,000. The optical design is based on a spherical grating monochromator (SGM) giving both high resolution and high flux throughput. Photon flux is calculated to be approximately 10{sup 12}--10{sup 13} photons per second with a beam size of approximately 1 x 1 mm{sup 2} at the sample.

  2. Imaging performance of a normal incidence soft X-ray telescope

    NASA Astrophysics Data System (ADS)

    Henry, J. P.; Spiller, E.; Weisskopf, M.

    1982-01-01

    Measurements are presented of the imaging performance of a normal incidence spherical soft X-ray mirror at BK-alpha (67.6 A). The reflector was a 124-layer coating consisting of alternating Re-W alloy and C layers with a protective C overcoat 34 A thick deposited on a Zerodur substrate. Measurements made at an angle of 1.5 deg off axis with the prototype of the Einstein Observatory high resolution imager reveal the resolution of the mirror to be about 1 arcsec FWHM, with 50% of the reflected power within the detector field of 512 arcsec contained within a diameter of 5 arcsec. The data demonstrate the practicality and potential good performance of normal-incidence soft X-ray optics, and show that the scattering performances of such devices may be as good or better than the best grazing incidence devices.

  3. Imaging at high spatial resolution: Soft x-ray microscopy to 15nm

    SciTech Connect

    Attwood, D.; Chao, W.; Anderson, E.; Liddle, J.A.; Harteneck, B.; Fischer, P.; Schneider, G.; Le Gros, M.; Larabell, C.

    2006-04-05

    Soft x-ray microscopy has now achieved 15 nm spatial resolution with new zone plates and bending magnet radiation. Combined with elemental sensitivity and flexible sample environment (applied magnetic or electric fields, wet samples, windows, overcoatings) this emerges as a valuable tool for nanoscience and nanotechnology, complimenting common electron and scanning tip microscopies. In this presentation we describe recent advances in spatial resolution, expectations for the near future, and applications to magnetic materials, bio-tomography, etc.

  4. Prototyping a Global Soft X-Ray Imaging Instrument for Heliophysics, Planetary Science, and Astrophysics Science

    NASA Technical Reports Server (NTRS)

    Collier, M. R.; Porter, F. S.; Sibeck, D. G.; Carter, J. A.; Chiao, M. P.; Chornay, D. J.; Cravens, T.; Galeazzi, M.; Keller, J. W.; Koutroumpa, D.; Kuntz, K.; Read, A. M.; Robertson, I. P.; Sembay, S.; Snowden, S.; Thomas, N.

    2012-01-01

    We describe current progress in the development of a prototype wide field-of-view soft X-ray imager that employs Lobstereye optics and targets heliophysics, planetary, and astrophysics science. The prototype will provide proof-of-concept for a future flight instrument capable of imaging the entire dayside magnetosheath from outside the magnetosphere. Such an instrument was proposed for the ESA AXIOM mission.

  5. Prototyping a Global Soft X-ray Imaging Instrument for Heliophysics, Planetary Science, and Astrophysics Science

    NASA Technical Reports Server (NTRS)

    Collier, Michael R.; Porter, F. Scott; Sibeck, David G.; Carter, Jenny A.; Chiao, Meng P.; Chornay, Dennis J.; Cravens, Thomas; Galeazzi, Massimiliano; Keller, John W.; Koutroumpa, Dimitra; Kuntz, Kip; Read, Any M.; Robertson, Ina P.; Sembay, Steve; Snowden, Steven; Thomas, Nick

    2012-01-01

    We describe current progress in the development of a prototype wide field-of-view soft X-ray imager that employs Lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The prototype will provide proof-of-concept for a future flight instrument capable of imaging the entire dayside magnetosheath from outside the magnetosphere. Such an instrument was proposed for the FSA AXIOM mission

  6. Stereo soft x-ray microscopy and elemental mapping of hematite and clay suspensions

    SciTech Connect

    Gleber, S.-C.; Thieme, J.; Chao, W.; Fischer, P.

    2008-09-01

    The spatial arrangements of hematite particles within aqueous soil and clay samples are investigated with soft X-ray microscopy, taking advantage of the elemental contrast at the Fe-L edge around E = 707 eV. In combination with stereo microscopy, information about spatial arrangements are revealed and correlated to electrostatic interactions of the different mixtures. Manipulation of a sample mounted to the microscope is possible and particles added while imaging can be detected.

  7. Development of in situ, at-wavelength metrology for soft x-ray nano-focusing

    SciTech Connect

    Yuan, Sheng Sam; Yashchuk, Valeriy V.; Goldberg, Kenneth A.; Celestre, Richard; McKinney, Wayne R.; Morrison, Gregory Y.; Warwick, Tony; Padmore, Howard A.

    2010-09-19

    At the Advanced Light Source (ALS), we are developing broadly applicable, high-accuracy, in situ, at-wavelength wavefront slope measurement techniques for Kirkpatrick-Baez (KB) mirror nano-focusing. We describe here details of the metrology beamline endstation, the at-wavelength tests, and an original alignment method that have already allowed us to precisely set a bendable KB mirror to achieve a FWHM focused spot size of ~;;120 nm, at 1-nm soft x-ray wavelength.

  8. Line identification and lifetime measurements in the XUV and soft X-ray regions

    NASA Technical Reports Server (NTRS)

    Sellin, I. A.

    1979-01-01

    A summary of the data acquired concerning line identification and lifetime measurements in the xuv and soft X-ray regions for a variety of both resonance transitions and forbidden transitions in ions of astrophysical interest is provided. Particular attention is called to a few papers which appeared in the Astrophysical Journal. These are of special relevance to specific astrophysical data needs. The many experiments completed in areas related to but somewhat outside the confines of the project title are mentioned.

  9. Discovery of Broad Soft X-ray Absorption Lines from the Quasar Wind in PDS 456

    NASA Astrophysics Data System (ADS)

    Reeves, J. N.; Braito, V.; Nardini, E.; Behar, E.; O'Brien, P. T.; Tombesi, F.; Turner, T. J.; Costa, M. T.

    2016-06-01

    High-resolution soft X-ray spectroscopy of the prototype accretion disk wind quasar, PDS 456, is presented. Here, the XMM-Newton reflection grating spectrometer spectra are analyzed from the large 2013-2014 XMM-Newton campaign, consisting of five observations of approximately 100 ks in length. During the last observation (OBS. E), the quasar is at a minimum flux level, and broad absorption line (BAL) profiles are revealed in the soft X-ray band, with typical velocity widths of {σ }{{v}}˜ {{10,000}} km s-1. During a period of higher flux in the third and fourth observations (OBS. C and D, respectively), a very broad absorption trough is also present above 1 keV. From fitting the absorption lines with models of photoionized absorption spectra, the inferred outflow velocities lie in the range ˜ 0.1{--}0.2c. The absorption lines likely originate from He and H-like neon and L-shell iron at these energies. A comparison with earlier archival data of PDS 456 also reveals a similar absorption structure near 1 keV in a 40 ks observation in 2001, and generally the absorption lines appear most apparent when the spectrum is more absorbed overall. The presence of the soft X-ray BALs is also independently confirmed by an analysis of the XMM-Newton EPIC spectra below 2 keV. We suggest that the soft X-ray absorption profiles could be associated with a lower ionization and possibly clumpy phase of the accretion disk wind, where the latter is known to be present in this quasar from its well-studied iron K absorption profile and where the wind velocity reaches a typical value of 0.3c.

  10. Observations of the quiet Sun from the soft x ray telescope on Yohkoh

    NASA Technical Reports Server (NTRS)

    Strong, Keith T.

    1992-01-01

    The Soft X-ray Telescope (SXT) on Yohkoh has obtained many thousands of images suitable for studying the quiet Sun. It will give a new perspective on the types of structures, their frequency of occurrence, and their lifetimes that will provide an invaluable tool for planning SOHO (Solar and Heliospheric Observatory) observations of the solar corona. The range of corona phenomena and the dynamic nature of the quiet Sun are illustrated.

  11. Correlative VIS-fluorescence and soft X-ray cryo-microscopy/tomography of adherent cells

    PubMed Central

    Hagen, Christoph; Guttmann, Peter; Klupp, Barbara; Werner, Stephan; Rehbein, Stefan; Mettenleiter, Thomas C.; Schneider, Gerd; Grünewald, Kay

    2012-01-01

    Soft X-ray cryo-microscopy/tomography of vitreous samples is becoming a valuable tool in structural cell biology. Within the ‘water-window’ wavelength region (2.34–4.37 nm), it provides absorption contrast images with high signal to noise ratio and resolution of a few tens of nanometer. Soft X-rays with wavelengths close to the K-absorption edge of oxygen penetrate biological samples with thicknesses in the micrometer range. Here, we report on the application of a recently established extension of the transmission soft X-ray cryo-microscope (HZB TXM) at the beamline U41-XM of the BESSY II electron storage ring by an in-column epi-fluorescence and reflected light cryo-microscope. We demonstrate the new capability for correlative fluorescence and soft X-ray cryo-microscopy/tomography of this instrument along a typical life science experimental approach – the correlation of a fluorophore-tagged protein (pUL34-GFP of pseudorabies virus, PrV, the nuclear membrane-anchored component of the nuclear egress complex of the Herpesviridae which interacts with viral pUL31) in PrV pUL34-GFP/pUL31 coexpressing mammalian cells, with virus-induced vesicular structures in the nucleus, expanding the nucleoplasmic reticulum. Taken together, our results demonstrate new possibilities to study the role of specific proteins in substructures of adherent cells, especially of the nucleus in toto, accessible to electron microscopy in thinned samples only. PMID:22210307

  12. XTEND: Extending the depth of field in cryo soft X-ray tomography.

    PubMed

    Otón, Joaquín; Pereiro, Eva; Conesa, José J; Chichón, Francisco J; Luque, Daniel; Rodríguez, Javier M; Pérez-Berná, Ana J; Sorzano, Carlos Oscar S; Klukowska, Joanna; Herman, Gabor T; Vargas, Javier; Marabini, Roberto; Carrascosa, José L; Carazo, José M

    2017-04-04

    We have developed a new data collection method and processing framework in full field cryo soft X-ray tomography to computationally extend the depth of field (DOF) of a Fresnel zone plate lens. Structural features of 3D-reconstructed eukaryotic cells that are affected by DOF artifacts in standard reconstruction are now recovered. This approach, based on focal series projections, is easily applicable with closed expressions to select specific data acquisition parameters.

  13. XTEND: Extending the depth of field in cryo soft X-ray tomography

    PubMed Central

    Otón, Joaquín; Pereiro, Eva; Conesa, José J.; Chichón, Francisco J.; Luque, Daniel; Rodríguez, Javier M.; Pérez-Berná, Ana J.; Sorzano, Carlos Oscar S.; Klukowska, Joanna; Herman, Gabor T.; Vargas, Javier; Marabini, Roberto; Carrascosa, José L.; Carazo, José M.

    2017-01-01

    We have developed a new data collection method and processing framework in full field cryo soft X-ray tomography to computationally extend the depth of field (DOF) of a Fresnel zone plate lens. Structural features of 3D-reconstructed eukaryotic cells that are affected by DOF artifacts in standard reconstruction are now recovered. This approach, based on focal series projections, is easily applicable with closed expressions to select specific data acquisition parameters. PMID:28374769

  14. High efficiency multilayer blazed gratings for EUV and soft X-rays: Recent developments

    SciTech Connect

    Voronov, Dmitriy; Ahn, Minseung; Anderson, Erik; Cambie, Rossana; Chang, Chih-Hao; Goray, Leonid; Gullikson, Eric; Heilmann, Ralf; Salmassi, Farhad; Schattenburg, Mark; Warwick, Tony; Yashchuk, Valeriy; Padmore, Howard

    2011-07-26

    Multilayer coated blazed gratings with high groove density are the best candidates for use in high resolution EUV and soft x-ray spectroscopy. Theoretical analysis shows that such a grating can be potentially optimized for high dispersion and spectral resolution in a desired high diffraction order without significant loss of diffraction efficiency. In order to realize this potential, the grating fabrication process should provide a perfect triangular groove profile and an extremely smooth surface of the blazed facets. Here we report on recent progress achieved at the Advanced Light Source (ALS) in fabrication of high quality multilayer coated blazed gratings. The blazed gratings were fabricated using scanning beam interference lithography followed by wet anisotropic etching of silicon. A 200 nm period grating coated with a Mo/Si multilayer composed with 30 bi-layers demonstrated an absolute efficiency of 37.6percent in the 3rd diffraction order at 13.6 nm wavelength. The groove profile of the grating was thoroughly characterized with atomic force microscopy before and after the multilayer deposition. The obtained metrology data were used for simulation of the grating efficiency with the vector electromagnetic PCGrate-6.1 code. The simulations showed that smoothing of the grating profile during the multilayer deposition is the main reason for efficiency losses compared to the theoretical maximum. Investigation of the grating with cross-sectional transmission electron microscopy revealed a complex evolution of the groove profile in the course of the multilayer deposition. Impact of the shadowing and smoothing processes on growth of the multilayer on the surface of the sawtooth substrate is discussed.

  15. Low energy electrons and ultra-soft X-rays irradiation of plasmid DNA. Technical innovations

    NASA Astrophysics Data System (ADS)

    Fromm, Michel; Boulanouar, Omar

    2016-11-01

    In this paper we present in a first part the latest results of our group which are in relation with the study of DNA damages inflicted by low energy electrons (0-20 eV) in ultra-high vacuum as well as in air under atmospheric conditions. A short description of the drop-casting technique we developed to produce thin and nanometre-scaled DNA layers onto graphite sheets is given. We provide the absolute cross-section for loss of supercoiled topology of plasmid DNA complexed with 1,3-diaminopropane (Dap) in the vacuum under 10 eV electron impact and suggest a specific pathway for the dissociation of the transient negative ion formed by resonant capture of such a low energy electron (LEE) by the DNA's phosphate group when complexed to Dap. Well-gauged DNA-Dap layers with various nanometre-scaled thicknesses are used to evaluate the effective attenuation length of secondary photo-LEEs in the energy range (0-20 eV). The values of 11-16 nm for DNA kept under atmospheric conditions are in good agreement with the rare literature data available and which are stemming from computer simulations. In a second part, we describe the method we have developed in order to expose liquid samples of plasmid DNA to ultra-soft X-rays (Al Kα line at 1.5 keV) under hydroxyl radical scavenging conditions. We provide an experimentally determined percentage of indirect effects in aqueous medium kept under standard conditions of 94.7±2.1% indirect effects; in satisfactory agreement with the data published by others (i.e. 97.7%) relative to gamma irradiation of frozen solutions (Tomita et al., 1995).

  16. The GEMpix detector as new soft X-rays diagnostic tool for laser produced plasmas

    NASA Astrophysics Data System (ADS)

    Claps, G.; Pacella, D.; Murtas, F.; Jakubowska, K.; Boutoux, G.; Burgy, F.; Ducret, J. E.; Batani, D.

    2016-10-01

    Laser produced plasmas lend to several interesting applications. The study of X-ray emission from this kind of plasmas is important not only to characterize plasmas itself but also to study the application of these particular plasmas as intense X-ray sources. In particular several emission configurations can be obtained using different kinds of targets and tuning the characteristics of the laser pulse delivered to the target. Typically, laser pulse duration ranges between a few tens of femtoseconds and tens of nanoseconds, with energies from few mJ to tens of kJ. X-ray photon emissions last for times comparable to the laser pulses and during this time a great number of photons can be emitted. The following paper presents a measure of the soft-X-ray emission on the ECLIPSE laser facility realized with a new triple-GEM gas detector (GEMpix). It is a hybrid gas detector with a C-MOS front-end electronics based on Medipix chips. In the present work, different targets have been used in order to test X-rays of different energies. In this paper, in particular, we present results obtained for copper and iron targets. GEMpix is able to realize a 2D imaging of the X-ray emission from plasma with a signal proportional to the energy released in the gas of the detector active volume. Then through a preliminary single photon equalization realized at the NIXT lab (ENEA), also the number of photons reaching the area of the detector has been estimated.

  17. The GEMpix detector as new soft X-rays diagnostic tool for laser produced plasmas.

    PubMed

    Claps, G; Pacella, D; Murtas, F; Jakubowska, K; Boutoux, G; Burgy, F; Ducret, J E; Batani, D

    2016-10-01

    Laser produced plasmas lend to several interesting applications. The study of X-ray emission from this kind of plasmas is important not only to characterize plasmas itself but also to study the application of these particular plasmas as intense X-ray sources. In particular several emission configurations can be obtained using different kinds of targets and tuning the characteristics of the laser pulse delivered to the target. Typically, laser pulse duration ranges between a few tens of femtoseconds and tens of nanoseconds, with energies from few mJ to tens of kJ. X-ray photon emissions last for times comparable to the laser pulses and during this time a great number of photons can be emitted. The following paper presents a measure of the soft-X-ray emission on the ECLIPSE laser facility realized with a new triple-GEM gas detector (GEMpix). It is a hybrid gas detector with a C-MOS front-end electronics based on Medipix chips. In the present work, different targets have been used in order to test X-rays of different energies. In this paper, in particular, we present results obtained for copper and iron targets. GEMpix is able to realize a 2D imaging of the X-ray emission from plasma with a signal proportional to the energy released in the gas of the detector active volume. Then through a preliminary single photon equalization realized at the NIXT lab (ENEA), also the number of photons reaching the area of the detector has been estimated.

  18. Probing symmetry and symmetry breaking in resonant soft-x-ray fluorescence spectra of molecules

    SciTech Connect

    Glans, P.; Gunnelin, K.; Guo, J.

    1997-04-01

    Conventional non-resonant soft X-ray emission brings about information about electronic structure through its symmetry and polarization selectivity, the character of which is governed by simple dipole rules. For centro-symmetric molecules with the emitting atom at the inversion center these rules lead to selective emission through the required parity change. For the more common classes of molecules which have lower symmetry or for systems with degenerate core orbitals (delocalized over identical sites), it is merely the local symmetry selectivity that provides a probe of the local atomic orbital contribution to the molecular orbital. For instance, in X-ray spectra of first row species the intensities essentially map the p-density at each particular atomic site, and, in a molecular orbital picture, the contribution of the local p-type atomic orbitals in the LCAO description of the molecular orbitals. The situation is different for resonant X-ray fluorescence spectra. Here strict parity and symmetry selectivity gives rise to a strong frequency dependence for all molecules with an element of symmetry. In addition to symmetry selectivity the strong frequency dependence of resonant X-ray emission is caused by the interplay between the shape of a narrow X-ray excitation energy function and the lifetime and vibrational broadenings of the resonantly excited core states. This interplay leads to various observable effects, such as linear dispersion, resonance narrowing and emission line (Stokes) doubling. Also from the point of view of polarization selectivity, the resonantly excited X-ray spectra are much more informative than the corresponding non-resonant spectra. Examples are presented for nitrogen, oxygen, and carbon dioxide molecules.

  19. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

    Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1990-01-01

    The annual progress report on Cosmic X Ray Physics is presented. Topics studied include: the soft x ray background, proportional counter and filter calibrations, the new sounding rocket payload: X Ray Calorimeter, and theoretical studies.

  20. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

    Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1991-01-01

    The annual progress report on Cosmic X Ray Physics for the period 1 Jan. to 31 Dec. 1990 is presented. Topics studied include: soft x ray background, new sounding rocket payload: x ray calorimeter, and theoretical studies.

  1. Design of High Resolution Soft X-Ray Microcalorimeters Using Magnetic Penetration Thermometers

    NASA Technical Reports Server (NTRS)

    Busch. Sarah; Balvin, Manuel; Bandler, Simon; Denis, Kevin; Finkbeiner, Fred; Porst, Jan-Patrick; Sadlier, Jack; Smith, Stephen; Stevenson, Thomas

    2012-01-01

    We have designed high-resolution soft x-ray microcalorimeters using magnetic penetration thermometers (MPTs) in an array of pixels covering a total of 2 square centimeters to have a resolving power of 300 at energies around 300 eV. This performance is desirable for studying the soft x-ray background from the warm hot intergalactic medium. MPT devices have small sensor heat capacity and high responsivities, which makes them excellent detector technology for attempting to attain sub-eV resolution. We are investigating the feasibility of pixels with absorbers that are 625 x 625 square micrometers, up to 1 x 1 square millimeters in area and 0.35 micrometer thick and thinner. Our tests have shown that suspended gold absorbers 0.35 micrometers thick (RRR = 6.7) are feasible to fabricate. We modeled the thermal diffusion from such thin gold over the size of a 625 x 625 square micrometer absorber, and conclude that the effect of the thermalization on the resolution of a 300 eV photon is an additional approximately 0.2 eV FWHM of broadening. We discuss the thermal effects of small absorber attachment sterns on solid substrate, as well as considerations for multiplexed readout. We will present the progress we have made towards building and testing this soft x-ray detector.

  2. Multi-spectral solar telescope array IV; The soft x-ray and extreme ultraviolet filters

    SciTech Connect

    Lindblom, J.F.; O'Neal, R.H.; Walker, A.B.C. Jr. ); Powell, F.R. ); Barbee, T.W. Jr. ); Hoover, R.B. ); Powell, S.F. )

    1991-08-01

    The multilayer mirrors used in the normal-incidence optical systems of the Multi-Spectral Solar Telescope Array (MSSTA) are efficient reflectors for soft x-ray/extreme ultraviolet (EUV) radiation at wavelengths that satisfy the Bragg condition, thus allowing a narrow band of the soft x-ray/EUV spectrum to be isolated. However, these same mirrors are also excellent reflectors in the visible, ultraviolet, and far-ultraviolet (FUV) part of the spectrum, where normal incidence reflectivities can exceed 50%. Furthermore, the sun emits far more radiation in the ultraviolet and visible part of the spectrum than it does in the soft x-ray/EUV. For this reason, thin foil filters are employed to eliminate the unwanted longer wavelength solar emission. The MSSTA instrument uses various combinations of thin foil filters composed of aluminum carbon, tellurium, potassium bromide, beryllium, molybdenum, rhodium, and phthalocyanine to achieve the desired radiation rejection characteristics. In this paper, the authors discuss issues concerning the design, manufacture, and predicted performance of MSSTA filters.

  3. Quantitative 3-D imaging of eukaryotic cells using soft X-ray tomography.

    PubMed

    Parkinson, Dilworth Y; McDermott, Gerry; Etkin, Laurence D; Le Gros, Mark A; Larabell, Carolyn A

    2008-06-01

    Imaging has long been one of the principal techniques used in biological and biomedical research. Indeed, the field of cell biology grew out of the first electron microscopy images of organelles in a cell. Since this landmark event, much work has been carried out to image and classify the organelles in eukaryotic cells using electron microscopy. Fluorescently labeled organelles can now be tracked in live cells, and recently, powerful light microscope techniques have pushed the limit of optical resolution to image single molecules. In this paper, we describe the use of soft X-ray tomography, a new tool for quantitative imaging of organelle structure and distribution in whole, fully hydrated eukaryotic Schizosaccharomyces pombe cells. In addition to imaging intact cells, soft X-ray tomography has the advantage of not requiring the use of any staining or fixation protocols--cells are simply transferred from their growth environment to a sample holder and immediately cryofixed. In this way the cells can be imaged in a near native state. Soft X-ray tomography is also capable of imaging relatively large numbers of cells in a short period of time, and is therefore a technique that has the potential to produce information on organelle morphology from statistically significant numbers of cells.

  4. DNA strand breaks induced by soft X-ray pulses from a compact laser plasma source

    NASA Astrophysics Data System (ADS)

    Adjei, Daniel; Wiechec, Anna; Wachulak, Przemyslaw; Ayele, Mesfin Getachew; Lekki, Janusz; Kwiatek, Wojciech M.; Bartnik, Andrzej; Davídková, Marie; Vyšín, Luděk; Juha, Libor; Pina, Ladislav; Fiedorowicz, Henryk

    2016-03-01

    Application of a compact laser plasma source of soft X-rays in radiobiology studies is demonstrated. The source is based on a laser produced plasma as a result of irradiation of a double-stream gas puff target with nanosecond laser pulses from a commercially available Nd:YAG laser. The source allows irradiation of samples with soft X-ray pulses in the "water window" spectral range (wavelength: 2.3-4.4 nm; photon energy: 280-560 eV) in vacuum or a helium atmosphere at very high-dose rates and doses exceeding the kGy level. Single-strand breaks (SSB) and double-strand breaks (DBS) induced in DNA plasmids pBR322 and pUC19 have been measured. The different conformations of the plasmid DNA were separated by agarose gel electrophoresis. An exponential decrease in the supercoiled form with an increase in linear and relaxed forms of the plasmids has been observed as a function of increasing photon fluence. Significant difference between SSB and DSB in case of wet and dry samples was observed that is connected with the production of free radicals in the wet sample by soft X-ray photons and subsequent affecting the plasmid DNA. Therefore, the new source was validated to be useful for radiobiology experiments.

  5. In Situ Soft X-ray Spectroscopy Characterization of Interfacial Phenomena in Energy Materials and Devices

    NASA Astrophysics Data System (ADS)

    Guo, Jinghua; Liu, Yi-Sheng; Kapilashrami, Mukes; Glans, Per-Anders; Bora, Debajeet; Braun, Artur; Velasco Vélez, Juan Jesús; Salmeron, Miquel; ALS/LBNL Team; EMPA, MSD/LBNL Collaboration

    2015-03-01

    Advanced energy technology arises from the understanding in basic science, thus rest in large on in-situ/operando characterization tools for observing the physical and chemical interfacial processes, which has been largely limited in a framework of thermodynamic and kinetic concepts or atomic and nanoscale. In many important energy systems such as energy conversion, energy storage and catalysis, advanced materials and functionality in devices are based on the complexity of material architecture, chemistry and interactions among constituents within. To understand and thus ultimately control the energy conversion and energy storage applications calls for in-situ/operando characterization tools. Soft X-ray spectroscopy offers a number of very unique features. We will present our development of the in-situ/operando soft X-ray spectroscopic tools of catalytic and electrochemical reactions in recent years, and reveal how to overcome the challenge that soft X-rays cannot easily peek into the high-pressure catalytic cells or liquid electrochemical cells. In this presentation a number of examples are given, including the nanocatalysts and the recent experiment performed for studying the hole generation in a specifically designed photoelectrochemical cell under operando conditions. The ALS is supported by the the U.S. Department of Energy.

  6. On the Nature of Soft X-Ray Radiation in Comets

    NASA Astrophysics Data System (ADS)

    Krasnopolsky, Vladimir

    1997-08-01

    EUVE and ROSAT observations of Comet Hyakutake revealed emission of 7 × 1024photons per second in the soft X-ray. We discuss and develop methods to calculate production of soft X-ray photons in cometary dust and gas by the following processes: (1) scattering and (2) fluorescence of solar X-rays; (3) K- and L-shell ionization by solar-wind protons and (4) electrons, and (5) by high-energy cometary ions; (6) bremsstrahlung of solar-wind electrons; (7) cometary magnetospheric substorms; (8) collisions between cometary and interplanetary dust particles; (9) scattering, fluorescence, and bremsstrahlung by very small particles with mass on the order of 10-19g; and (10) charge transfer of the solar-wind heavy ions with cometary molecules suggested by T. E. Cravens (1997,Geophys. Res. Lett.24,105-108). Very small attogram particles were detected in Comet Halley by N. G. Utterback and J. Kissel (1990,Astron. J.100,1315-1322) using the PUMA and PIA dust analyzers from the Vega and Giotto spacecraft. Of all these processes, only scattering by very small particles and charge transfer of the solar-wind heavy ions are capable of producing the measured soft X-ray emission. In the case of very small particles, the mean particle mass of 4.6 × 10-19g suggested by Utterback and Kissel implies that the total production of these particles, which exceeds that of gas by a factor 3.6 (in mass), is inconsistent with the polarization and color of Comet Halley. Both polarization and color require a reduction of the mean mass to (1-2) × 10-19g. This reduction strongly affects the visible brightness of the particles, which is proportional tom2, with a relatively weak effect on the soft X-ray emission. We calculate the charge transfer process using the solar-wind ion densities and velocities in comet from both the model of T. I. Gombosiet al.(1994,J. Geophys. Res.99,21,525-21,539) and the Giotto measurements of α-particles and He+ions in Comet Halley. The calculated emission constitutes 20

  7. Comparison of hard and soft x-ray photoelectron spectra of silicon

    NASA Astrophysics Data System (ADS)

    Offi, F.; Werner, W. S. M.; Sacchi, M.; Torelli, P.; Cautero, M.; Cautero, G.; Fondacaro, A.; Huotari, S.; Monaco, G.; Paolicelli, G.; Smekal, W.; Stefani, G.; Panaccione, G.

    2007-08-01

    A detailed comparison of the surface sensitivity of x-ray photoemission spectroscopy for hard and soft x rays is presented and discussed. Electron scattering parameters and their energy dependence are given for Si and two Si spectra are analyzed: a MgKα (hν=1253.6eV) excited spectrum of the Si2p and 2s lines and a hard x-ray excited spectrum (hν=5925eV) of the Si1s line. The differential inelastic scattering characteristics for Si are extracted from reflection electron energy loss spectra taken at energies of 1500 and 4000eV . Using these scattering characteristics and electron mean free paths from the literature, simulated spectra are compared with experiment. The experimental spectra are deconvoluted to give the true intrinsic line shape corresponding to the theoretical collision statistics when interference effects between intrinsic and extrinsic scattering are neglected. The magnitude of interference effects cannot be assessed by our analysis. Within the (unknown) uncertainty introduced by neglecting interference effects, it is possible to determine the relative intensity of intrinsic and extrinsic excitations. In this way, it is found that in the case of the soft x-ray excited photoelectron spectrum of the shallower electronic shells ( 2p and 2s ), intrinsic plasmon creation is rather weak, and the apparent asymmetric line shape of the spectrum might be interpreted as the fact that electron-hole pair creation dominates the intrinsic loss spectrum, while an alternative explanation in terms of surface core level shifted components is also proposed. For the deeper core electronic shell, probed with hard x rays, the opposite situation is observed: while intrinsic electron-hole pair creation was not observed, a strong contribution of intrinsic plasmon losses of about 30% was seen.

  8. Duplex multiwire proportional x-ray detector for multichord time-resolved soft x-ray and electron temperature measurements on T-10 tokamaka)

    NASA Astrophysics Data System (ADS)

    Sushkov, A. V.; Andreev, V. F.; Kravtsov, D. E.

    2008-10-01

    Compact 64-channel multiwire proportional chamber is successfully used on T-10 and TCV tokamaks as a continuous-current soft x-ray detectors. The duplex multiwire proportional x-ray detector is a new generation of these detectors. It has been designed for simultaneous multichord measurement of plasma soft x-ray emissivity in a two spectral ranges and determination of the electron temperature by the two-absorber method. The detector consists of two identical multiwire proportional chambers filled by 90%Kr+10%CH4 gas mixture at atmospheric pressure. The first multiwire chamber has 64 channels. The second multiwire chamber (installed behind the first one) has 32 channels. Both chambers view the plasma through the one helium-filled slot-hole camera. Thus, the first multiwire chamber serves as an absorber filter for the second one. Such construction of the detector allows us in addition to soft x-ray measurements to provide measurement of the plasma core electron temperature with spatial resolution of about 2cm and a time resolution of less than 50μs. The construction of the detector and experimental results illustrating the potential of the diagnostic are presented.

  9. UV, VUV and soft X-ray photoabsorption of dimethyl ether by dipole (e,e) spectroscopies

    NASA Astrophysics Data System (ADS)

    Feng, Renfei; Cooper, Glyn; Brion, C. E.

    2000-10-01

    Absolute UV and VUV photoabsorption oscillator strengths (cross-sections) for the valence shell discrete and continuum regions of dimethyl ether (CH 3OCH 3, DME) have been measured from 5 to 32 eV using high resolution (HR) (˜0.05 eV f.w.h.m.) dipole (e,e) spectroscopy. A wide-range spectrum, spanning the UV, VUV and soft X-ray regions, from 5 to 200 eV has also been obtained at low resolution (LR) (˜1 eV f.w.h.m.), and this has been used to determine the absolute oscillator strength scale by employing valence shell Thomas-Reiche-Kuhn (i.e., S(0)) sum-rule normalization. The presently reported HR and LR absolute photoabsorption oscillator strengths are compared with previously published data from direct photoabsorption measurements in those limited energy regions where such data are available. Evaluation of the S(-2) sum using the presently reported absolute differential photoabsorption oscillator strength data gives a static dipole polarizability for dimethyl ether in excellent agreement (within 0.5%) with previously reported polarizability values. Other dipole sums S( u), ( u=-1,-3,-4,-5,-6,-8,-10), and logarithmic dipole sums L( u), ( u=-1 to -6), are also determined from the presently reported absolute differential photoabsorption oscillator strength data using dipole sum rules.

  10. Compact scanning soft-x-ray microscope using a laser-produced plasma source and normal-incidence multilayer mirrors.

    PubMed

    Trail, J A; Byer, R L

    1989-06-01

    We have constructed a scanning soft-x-ray microscope that uses a laser-produced plasma as the soft-x-ray source and normal-incidence multilayer-coated mirrors in a Schwarzschild configuration as the focusing optics. The microscope operates at a wavelength of 14 nm, has a spatial resolution of 0.5 microm, and has a soft-x-ray photon flux through the focus of 10(4)-10(5) sec(-1) when operated with only 170 mW of average laser power. The microscope is compact; the complete system, including the laser, fits on a single optical table.

  11. X-ray radiography of multi-Mbar shock waves for absolute equation-of-state studies

    NASA Astrophysics Data System (ADS)

    Hicks, Damien; Hansen, Freddy; Bradley, David; Celliers, Peter; Eggert, Jon; Collins, Gilbert; Boehly, Thomas; Meyerhofer, David

    2004-11-01

    At high energy density conditions the equation of state of materials is not amenable to the traditional theoretical approximations of either plasma or condensed matter physics, placing a high premium on shock wave measurements. We present results from a new side-on radiography technique designed to achieve absolute Hugoniot measurements of multi-Mbar laser-driven shocks. Using a backlit pinhole and keV x-rays, spatial coherence of the x-rays is sufficient to generate both phase and absorption contrast at a shock front, leading to the prospect of direct measurements of shock wave densities in addition to shock and particle velocities.

  12. Absolute L X-ray intensities in the decays of 230Th, 234U, 238Pu and 244Cm

    NASA Astrophysics Data System (ADS)

    Johnston, Peter N.; Burns, Peter A.

    1995-02-01

    The absolute L X-ray emission rates of 230Th, 234U, 238Pu and 244Cm have been measured. The rates were obtained by an alpha-particle gated photon spectrometry technique involving the use of a highly calibrated Ge(HP) detector in coincidence with a SiSB detector. The directional correlation between L X-rays and alpha-particles has been accounted for. The present results are compared with previous experimental values and theoretical estimates. Agreement with theoretical estimates is good, however few of the previous experimental values agree with the present work. Differences with previous work partly seem to lie with the detector calibration.

  13. Depth Probing Soft X-ray Microprobe (DPSXRM) for High Resolution Probing of Earth's Microstructural Samples

    NASA Astrophysics Data System (ADS)

    Dikedi, P. N.

    2015-12-01

    The Cambrian explosion; occurrence of landslides in very dry weather conditions; rockslides; dead, shriveled-up and crumbled leaves possessing fossil records with the semblance of well preserved, flat leaves; abundance of trilobite tracks in lower and higher rock layers; and sailing stones are enigmas demanding demystifications. These enigmas could be elucidated when data on soil structure, texture and strength are provided by some device with submicrometre accuracy; for these and other reasons, the design of a Depth Probing Soft X-ray Microprobe (DPSXRM), is being proposed; it is expected to deliver soft X-rays, at spatial resolution, ϛ≥600nm and to probe at the depth of 0.5m in 17s. The microprobe is portable compared to a synchrotron radiation facility (Diamond Light Source has land size of 43,300m2); spatial resolution,ϛ , of the DPSXRM surpasses those of the X-ray Fluorescence microanalysis (10µm), electron microprobe (1-3µm) and ion microprobe (5->30µm); the DPSXRM has allowance for multiple targets. Vanadium and Manganese membranes are proposed owing to respective 4.952KeV VKα1 and 5.899KeV MnKα1 X-rays emitted, which best suits micro-probing of Earth's microstructural samples. Compound systems like the Kirk-Patrick and Baez and Wolter optics, aspheric mirrors like elliptical and parabolic optics, small apertures and Abbe sine condition are employed to reduce or remove astigmatism, obliquity, comatic and spherical aberrations—leading to good image quality. Results show that 5.899KeV MnKα1 and 4.952KeV VKα1 soft X-rays will travel a distance of 2.75mm to form circular patches of radii 2.2mm and 2.95mm respectively. Zone plate with nth zone radius of 1.5mm must be positioned 1.5mm and 2mm from the electron gun if circular patches must be formed from 4.952KeV VKα1 and 5.899KeV MnKα1 soft X-rays respectively. The focal lengths of 0.25μm≤ƒ≤1.50μm and 0.04μm≤ƒ≤0.2μm covered by 4.952KeV VKα1 and 5.899KeV Mn Kα1 soft X-Rays, will

  14. First peek of ASTRO-H Soft X-ray Telescope (SXT) in-orbit performance

    NASA Astrophysics Data System (ADS)

    Okajima, Takashi; Soong, Yang; Serlemitsos, Peter; Mori, Hideyuki; Olsen, Larry; Robinson, David; Koenecke, Richard; Chang, Bill; Hahne, Devin; Iizuka, Ryo; Ishida, Manabu; Maeda, Yoshitomo; Sato, Toshiki; Kikuchi, Naomichi; Kurashima, Sho; Nakaniwa, Nozomi; Hayashi, Takayuki; Ishibashi, Kazunori; Miyazawa, Takuya; Tachibana, Kenji; Tamura, Keisuke; Furuzawa, Akihiro; Tawara, Yuzuru; Sugita, Satoshi

    2016-07-01

    ASTRO-H (Hitomi) is a Japanese X-ray astrophysics satellite just launched in February, 2016, from Tanegashima, Japan by a JAXA's H-IIA launch vehicle. It has two Soft X-ray Telescopes (SXTs), among other instruments, that were developed by NASA's Goddard Space Flight Center in collaboration with ISAS/JAXA and Nagoya University. One is for an X-ray micro-calorimeter instrument (Soft X-ray Spectrometer, SXS) and the other for an X-ray CCD camera (Soft X-ray Imager, SXI), both covering the X-ray energy band up to 15 keV. The two SXTs were fully characterized at the 30-m X-ray beamline at ISAS/JAXA. The combined SXT+SXS system effective area is about 250 and 300 cm2 at 1 and 6 keV, respectively, although observations were performed with the gate valve at the dewar entrance closed, which blocks most of low energy X-rays and some of high energy ones. The angular resolution for SXS is 1.2 arcmin (Half Power Diameter, HPD). The combined SXT+SXI system effective area is about 370 and 350 cm2 at 1 and 6 keV, respectively. The angular resolution for SXI is 1.3 arcmin (HPD). The both SXTs have a field of view of about 16 arcmin (FWHM of their vignetting functions). The SXT+SXS field of view is limited to 3 x 3 arcmin by the SXS array size. In-flight data available to the SXT team was limited at the time of this conference and a point-like source data is not available for the SXT+SXS. Although due to lack of attitude information we were unable to reconstruct a point spread function of SXT+SXI, according to RXJ1856.5-3754 data, the SXT seems to be working as expected in terms of imaging capability. As for the overall effective area response for both SXT+SXS and SXT+SXI, consistent spectral model fitting parameters with the previous measurements were obtained for Crab and G21.5-0.9 data. On the other hand, their 2-10 keV fluxes differ by about 20% at this point. Calibration work is still under progress. The SXT is the latest version of the aluminum foil X-ray mirror, which is

  15. Calibration of the Soft X-ray Telescopes (SXT) Onboard the ASTRO-H Satellite

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    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 mirrors, of which the energy range is from a few hundred eV to 15 keV. 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 landing 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 m, 229 m, and 305 m 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 m. 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), FM1 or FM2, 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 were carried out, and optical quality of the telescopes has been confirmed. The optical and x-ray calibrations also include

  16. Soft X-ray emission in kink-unstable coronal loops

    NASA Astrophysics Data System (ADS)

    Pinto, R. F.; Vilmer, N.; Brun, A. S.

    2015-04-01

    Context. Solar flares are associated with intense soft X-ray emission generated by the hot flaring plasma in coronal magnetic loops. Kink-unstable twisted flux-ropes provide a source of magnetic energy that can be released impulsively and may account for the heating of the plasma in flares. Aims: We investigate the temporal, spectral, and spatial evolution of the properties of the thermal continuum X-ray emission produced in such kink-unstable magnetic flux-ropes and discuss the results of the simulations with respect to solar flare observations. Methods: We computed the temporal evolution of the thermal X-ray emission in kink-unstable coronal loops based on a series of magnetohydrodynamical numerical simulations. The numerical setup consisted of a highly twisted loop embedded in a region of uniform and untwisted background coronal magnetic field. We let the kink instability develop, computed the evolution of the plasma properties in the loop (density, temperature) without accounting for mass exchange with the chromosphere. We then deduced the X-ray emission properties of the plasma during the whole flaring episode. Results: During the initial (linear) phase of the instability, plasma heating is mostly adiabatic (as a result of compression). Ohmic diffusion takes over as the instability saturates, leading to strong and impulsive heating (up to more than 20 MK), to a quick enhancement of X-ray emission, and to the hardening of the thermal X-ray spectrum. The temperature distribution of the plasma becomes broad, with the emission measure depending strongly on temperature. Significant emission measures arise for plasma at temperatures higher than 9 MK. The magnetic flux-rope then relaxes progressively towards a lower energy state as it reconnects with the background flux. The loop plasma suffers smaller sporadic heating events, but cools down globally by thermal conduction. The total thermal X-ray emission slowly fades away during this phase, and the high

  17. An in situ electrochemical soft X-ray spectromicroscopy investigation of Fe galvanically coupled to Au.

    PubMed

    Gianoncelli, A; Kaulich, B; Kiskinova, M; Prasciolu, M; Urzo, B D; Bozzini, B

    2011-06-01

    In this paper we report a pioneering electrochemical study of the galvanic coupling of Au and Fe in neutral aqueous solutions containing sulphate and fluoride ions, carried out by synchrotron-based in situ soft X-ray imaging and X-ray absorption microspectroscopy. The investigation was performed at the TwinMic X-ray Microscopy station at Elettra synchrotron facility combining X-ray imaging with μ-XAS with sub-micron lateral resolution. Using a purposely developed model thin-layer wet cell the morphology and chemical evolution of Fe electrodes in contact with aqueous solutions containing Na2SO4 and NaF have been investigated. The obtained results shed light on fundamental aspects regarding stability of Fe-based metallic bipolar plates in different electrochemical environments, an important issue for durability of polymer-electrolyte fuel cells. Imaging morphological features typical of the relevant electrochemical processes with chemical contrast, yields details on the spatial distribution and speciation of Fe resulting from corrosion of the Fe electrodes in the working fuel cells.

  18. The Soft X-ray Spectrophotometer SphinX for the CORONAS-Photon Mission

    NASA Astrophysics Data System (ADS)

    Sylwester, Janusz; Kowalinski, Miroslaw; Szymon, Gburek; Bakala, Jaroslaw; Kuzin, Sergey; Kotov, Yury; Farnik, Frantisek; Reale, Fabio

    The purpose, construction details and calibration results of the new design, Polish-led solar X-ray spectrophotometer SphinX will be presented. The instrument constitutes a part of the Russian TESIS X-ray and EUV complex aboard the forthcoming CORONAS-Photon solar mission to be launched later in 2008. SphinX uses Si-PIN detectors for high time resolution (down to 0.01 s) measurements of solar spectra in the energy range between 0.5 keV and 15 keV. The spectral resolution allows separating 256 individual energy channels in this range with particular groups of lines clearly distinguishable. Unprecedented accuracy of the instrument calibration at the XACT (Palermo) and BESSY (Berlin) synchrotron will allow for establishing the solar soft X-ray photometric reference system. The cross-comparison between SphinX and the other instruments presently in orbit like XRT on Hinode, RHESSI and GOES X-ray monitor, will allow for a precise determination of the coronal emission measure and temperature during both very low and very high activity periods. Examples of the detectors' ground calibration results as well as the calculated synthetic spectra will be presented. The operation of the instrument while in orbit will be discussed allowing for suggestions from other groups to be still included in mission planning.

  19. Soft X-ray oscillations during the flare of 7 August 1972

    NASA Technical Reports Server (NTRS)

    Thomas, Roger J.; Neupert, Werner M.; Thompson, William T.

    1986-01-01

    Unique observations from OSO-7 of the intense flare on 7 August 1972 are presented, showing 1.6 second oscillations in it's soft X-ray emission which are long enduring, extremely regular, and initially of large amplitude. For approximately 20 minutes just after flare maximum, the X-ray intensity of an area 20 arc second square near the flare's core was monitored with 160 millisecond time resolution in two channels, 2-8A and 8-16A. Each channel recorded over 700 cycles of the X-ray oscillations, which remained remarkably stable in phase and period throughout the entire observations, but with gradually diminishing amplitude. The observed period does not correspond to any known operational periodicity in either the instrument or the spacecraft and cannot be attributed to aliasing with any other oscillatory component. Channel ratios indicate that both the temperature and electron density of the emitting plasma are enhanced at the peak of each cycle. There is indirect evidence that the X-ray pulsations are occurring only in a relatively small portion of an elongated feature, presumed to be a loop or arcade of loops.

  20. Thin conductive diamond films as beam intensity monitors for soft x-ray beamlines

    NASA Astrophysics Data System (ADS)

    Kummer, K.; Fondacaro, A.; Yakhou-Harris, F.; Sessi, V.; Pobedinskas, P.; Janssens, S. D.; Haenen, K.; Williams, O. A.; Hees, J.; Brookes, N. B.

    2013-03-01

    Quantitative analysis of X-ray absorption and dichroism data requires knowledge of the beamline photon flux during the measurements. We show that thin conductive (B-doped) diamond thin films can be an alternative to the widely used gold meshes for monitoring the beam intensity of soft X-ray beamlines in situ. Limited by the carbon extended x-ray absorption fine structure oscillations, the diamond films become applicable beginning from about 600 eV photon energy, where the important transition metal edges and the rare-earth edges are found. The 100 nm and 250 nm thick free-standing diamond films were grown and tested against standard gold meshes in real-life dichroism experiments performed at beamline ID08 of the European Synchrotron Radiation Facility, Grenoble, France. Quantitative agreement was found between the two experimental data sets. The films feature an extremely high transmission of about 90% and, at the same time, yield a sufficiently strong and clean reference signal. Furthermore, the thin films do not affect the shape of the transmitted beam. X-rays passing mesh-type monitors are subject to diffraction effects, which widen the beam and become particularly disturbing for small beamsizes in the micrometer range.

  1. Thin conductive diamond films as beam intensity monitors for soft x-ray beamlines

    SciTech Connect

    Kummer, K.; Fondacaro, A.; Yakhou-Harris, F.; Sessi, V.; Brookes, N. B.; Pobedinskas, P.; Janssens, S. D.; Haenen, K.; Williams, O. A.; Hees, J.

    2013-03-15

    Quantitative analysis of X-ray absorption and dichroism data requires knowledge of the beamline photon flux during the measurements. We show that thin conductive (B-doped) diamond thin films can be an alternative to the widely used gold meshes for monitoring the beam intensity of soft X-ray beamlines in situ. Limited by the carbon extended x-ray absorption fine structure oscillations, the diamond films become applicable beginning from about 600 eV photon energy, where the important transition metal edges and the rare-earth edges are found. The 100 nm and 250 nm thick free-standing diamond films were grown and tested against standard gold meshes in real-life dichroism experiments performed at beamline ID08 of the European Synchrotron Radiation Facility, Grenoble, France. Quantitative agreement was found between the two experimental data sets. The films feature an extremely high transmission of about 90% and, at the same time, yield a sufficiently strong and clean reference signal. Furthermore, the thin films do not affect the shape of the transmitted beam. X-rays passing mesh-type monitors are subject to diffraction effects, which widen the beam and become particularly disturbing for small beamsizes in the micrometer range.

  2. Development of CCD Cameras for Soft X-ray Imaging at the National Ignition Facility

    SciTech Connect

    Teruya, A. T.; Palmer, N. E.; Schneider, M. B.; Bell, P. M.; Sims, G.; Toerne, K.; Rodenburg, K.; Croft, M.; Haugh, M. J.; Charest, M. R.; Romano, E. D.; Jacoby, K. D.

    2013-09-01

    The Static X-Ray Imager (SXI) is a National Ignition Facility (NIF) diagnostic that uses a CCD camera to record time-integrated X-ray images of target features such as the laser entrance hole of hohlraums. SXI has two dedicated positioners on the NIF target chamber for viewing the target from above and below, and the X-ray energies of interest are 870 eV for the “soft” channel and 3 – 5 keV for the “hard” channels. The original cameras utilize a large format back-illuminated 2048 x 2048 CCD sensor with 24 micron pixels. Since the original sensor is no longer available, an effort was recently undertaken to build replacement cameras with suitable new sensors. Three of the new cameras use a commercially available front-illuminated CCD of similar size to the original, which has adequate sensitivity for the hard X-ray channels but not for the soft. For sensitivity below 1 keV, Lawrence Livermore National Laboratory (LLNL) had additional CCDs back-thinned and converted to back-illumination for use in the other two new cameras. In this paper we describe the characteristics of the new cameras and present performance data (quantum efficiency, flat field, and dynamic range) for the front- and back-illuminated cameras, with comparisons to the original cameras.

  3. The HEAO-1 soft X-ray survey of cataclysmic variable stars

    NASA Technical Reports Server (NTRS)

    Cordova, F. A.; Jensen, K. A.; Nugent, J. J.

    1981-01-01

    A survey of the soft X-ray emission from 206 cataclysmic variable stars, including dwarf novae in optically quiescent states, classical novae, recurrent novae, nova-like objects and polars, is reported. This is an extension of a previous survey of dwarf novae in outbursts by Cordova et al. (1980). The number of surveyed stars that correspond to features greater than 2 sigma is not in excess of the number of chance coincidences expected on the basis of a random sample of positions distributed over the entire sky. While a few cataclysmic variables have been previously identified as X-ray sources, the results of this survey imply that cataclysmic variables as a class must be, at best, low-luminosity X-ray sources with fluxes below the HEAO-1 A2 detector's sensitivity limit of a few times 10 to the -11th erg/sq cm-s in the energy range 0.1-3 keV. The X-ray luminosities of the cataclysmic variables are consistent with predictions from disk accretion models, provided that a wide range of accretion rates apply.

  4. Imaging mammalian cells with soft x rays: The importance of specimen preparation

    SciTech Connect

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

    1997-04-01

    Studies of mammalian cell structure and spatial organization are a very prominent part of modern cell biology. The interest in them as well as their size make them very accommodating subject specimens for imaging with soft x-rays using the XM-1 transmission microscope built and operated by The Center for X-ray Optics on Beam Line 6.1 at the Advanced Light Source. The purpose of these experiments was to determine if the fixative protocols normally used in electron or visible light microscopy were adequate to allow imaging cells, either fibroblasts or neurons, with minimal visible radiation damage due to imaging with soft x-rays at 2.4 nm. Two cell types were selected. Fibroblasts are easily cultured but fragile cells which are commonly used as models for the detailed study of cell physiology. Neurons are complex and sensitive cells which are difficult to prepare and to culture for study in isolation from their connections with surrounding cells. These cell types pose problems in their preparation for any microscopy. To improve the contrast and to prevent postmortem alteration of the chemistry and hence the structure of cells extracted from culture or from living organisms, fixation and staining techniques are employed in electron and visible light microscopy. It has been accepted by biologists for years that these treatments create artifacts and false structure. The authors have begun to develop protocols for specimens of each of these two cell types for soft x-ray microscopy which will preserve them in as near normal state as possible using minimal fixation, and make it possible to image them in either a hydrated or dried state free of secondary addition of stains or other labels.

  5. A Deep X-Ray View of the Bare AGN Ark 120. I. Revealing the Soft X-Ray Line Emission

    NASA Astrophysics Data System (ADS)

    Reeves, J. N.; Porquet, D.; Braito, V.; Nardini, E.; Lobban, A.; Turner, T. J.

    2016-09-01

    The Seyfert 1 galaxy Ark 120 is a prototype example of the so-called class of bare nucleus active galactic nuclei (AGNs), whereby there is no known evidence for the presence of ionized gas along the direct line of sight. Here deep (>400 ks exposure), high-resolution X-ray spectroscopy of Ark 120 is presented from XMM-Newton observations that were carried out in 2014 March, together with simultaneous Chandra/High Energy Transmission Grating exposures. The high-resolution spectra confirmed the lack of intrinsic absorbing gas associated with Ark 120, with the only X-ray absorption present originating from the interstellar medium (ISM) of our own Galaxy, with a possible slight enhancement of the oxygen abundance required with respect to the expected ISM values in the solar neighborhood. However, the presence of several soft X-ray emission lines are revealed for the first time in the XMM-Newton RGS spectrum, associated with the AGN and arising from the He- and H-like ions of N, O, Ne, and Mg. The He-like line profiles of N, O, and Ne appear velocity broadened, with typical FWHMs of ˜5000 km s-1, whereas the H-like profiles are unresolved. From the clean measurement of the He-like triplets, we deduce that the broad lines arise from a gas of density n e ˜ 1011 cm-3, while the photoionization calculations infer that the emitting gas covers at least 10% of 4π steradian. Thus the broad soft X-ray profiles appear coincident with an X-ray component of the optical-UV broad-line region on sub-parsec scales, whereas the narrow profiles originate on larger parsec scales, perhaps coincident with the AGN narrow-line region. The observations show that Ark 120 is not intrinsically bare and substantial X-ray-emitting gas exists out of our direct line of sight toward this AGN.

  6. On the origin of the soft X-ray background. [in cosmological observations

    NASA Technical Reports Server (NTRS)

    Wang, Q. D.; Mccray, Richard

    1993-01-01

    The angular autocorrelation function and spectrum of the soft X-ray background is studied below a discrete source detection limit, using two deep images from the Rosat X-ray satellite. The average spectral shape of pointlike sources, which account for 40 to 60 percent of the background intensity, is determined by using the autocorrelation function. The background spectrum, in the 0.5-0.9 keV band (M band), is decomposed into a pointlike source component characterized by a power law and a diffuse component represented by a two-temperature plasma. These pointlike sources cannot contribute more than 60 percent of the X-ray background intensity in the M band without exceeding the total observed flux in the R7 band. Spectral analysis has shown that the local soft diffuse component, although dominating the background intensity at energies not greater than 0.3 keV, contributes only a small fraction of the M band background intensity. The diffuse component may represent an important constituent of the interstellar or intergalactic medium.

  7. Confocal soft X-ray scanning transmission microscopy: setup, alignment procedure and limitations

    PubMed Central

    Späth, Andreas; Raabe, Jörg; Fink, Rainer H.

    2015-01-01

    Zone-plate-based scanning transmission soft X-ray microspectroscopy (STXM) is a well established technique for high-contrast imaging of sufficiently transparent specimens (e.g. ultrathin biological tissues, polymer materials, archaeometric specimens or magnetic thin films) with spatial resolutions in the regime of 20 nm and high spectroscopic or chemical sensitivity. However, due to the relatively large depth of focus of zone plates, the resolution of STXM along the optical axis so far stays unambiguously behind for thicker X-ray transparent specimens. This challenge can be addressed by the implementation of a second zone plate in the detection pathway of the beam, resulting in a confocal arrangement. Within this paper a first proof-of-principle study for a confocal STXM (cSTXM) and an elaborate alignment procedure in transmission and fluorescence geometry are presented. Based on first confocal soft X-ray micrographs of well known specimens, the advantage and limitation of cSTXM as well as further development potentials for future applications are discussed. PMID:25537596

  8. Long pulse Soft X-ray Emission from Laser Generated Irradiated Gold Foils

    NASA Astrophysics Data System (ADS)

    Davis, Joshua; Frank, Yechiel; Raicher, Erez; Fraenkel, Moshe; Keiter, Paul; Klein, Sallee; Drake, R. P.; Shvarts, Dov

    2016-10-01

    Long pulse soft x-ray sources (SXS) allow for flexibility in high-energy-density experimental designs by providing a means of driving matter to the high temperatures needed, for example to study radiation waves in different materials. SXSs can be made by using lasers to heat a high-Z thin foil, which then acts as a quasi-blackbody emitter. Previous studies of the x-ray emission characteristics of gold foils have focused on laser pulses of 1ns or less. We performed experiments using a 6.0ns laser pulse with energy of 2kJ on the Omega-60 system to generate and characterize multi-ns laser heated Au foils of thicknesses between 0.5-2.0 μm. We measured the 2D spatial profile of the emission with a soft x-ray camera and the time history of the emission with the Dante photodiode array . Effective temperatures for the emission were then calculated using the Dante measurements. Discussion of experimental results and a comparison with 1-D Rad-Hydro NLTE simulations will be presented.

  9. Extended adiabatic blast waves and a model of the soft X-ray background

    NASA Technical Reports Server (NTRS)

    Cox, D. P.; Anderson, P. R.

    1982-01-01

    The suggestion has been made that much of the soft X-ray background observed in X-ray astronomy might arise from being inside a very large supernova blast wave propagating in the hot, low-density component of the interstellar (ISM) medium. An investigation is conducted to study this possibility. An analytic approximation is presented for the nonsimilar time evolution of the dynamic structure of an adiabatic blast wave generated by a point explosion in a homogeneous ambient medium. A scheme is provided for evaluating the electron-temperature distribution for the evolving structure, and a procedure is presented for following the state of a given fluid element through the evolving dynamical and thermal structures. The results of the investigation show that, if the solar system were located within a blast wave, the Wisconsin soft X-ray rocket payload would measure the B and C band count rates that it does measure, provided conditions correspond to the values calculated in the investigation.

  10. The soft X-ray diffuse background observed with the HEAO 1 low-energy detectors

    NASA Technical Reports Server (NTRS)

    Garmire, G. P.; Nousek, J. A.; Apparao, K. M. V.; Burrows, D. N.; Fink, R. L.; Kraft, R. P.

    1992-01-01

    Results of a study of the diffuse soft-X-ray background as observed by the low-energy detectors of the A-2 experiment aboard the HEAO 1 satellite are reported. The observed sky intensities are presented as maps of the diffuse X-ray background sky in several energy bands covering the energy range 0.15-2.8 keV. It is found that the soft X-ray diffuse background (SXDB) between 1.5 and 2.8 keV, assuming a power law form with photon number index 1.4, has a normalization constant of 10.5 +/- 1.0 photons/sq cm s sr keV. Below 1.5 keV the spectrum of the SXDB exceeds the extrapolation of this power law. The low-energy excess for the NEP can be fitted with emission from a two-temperature equilibrium plasma model with the temperatures given by log I1 = 6.16 and log T2 = 6.33. It is found that this model is able to account for the spectrum below 1 keV, but fails to yield the observed Galactic latitude variation.

  11. Imaging soft x-ray spectrometers based on superconducting tunnel junctions

    NASA Astrophysics Data System (ADS)

    Verhoeve, P.; Martin, D. D. E.; Venn, R.

    2010-07-01

    X-ray detectors based on superconducting tunnel junctions (STJs) have demonstrated good energy resolution in the soft X-ray energy range 0.1-6 keV. In particular DROIDS (Distributed Read Out Imaging Devices), consisting of a superconducting absorber strip with superconducting tunnel junctions as read-out devices on either end, could combine this high resolving power with a large sensitive area and good soft X-ray detection efficiency. In this paper we present results on the spectroscopic performance of Al and Ta/Al DROIDs with different absorber materials (Ta, Re) and with variations in absorber configurations: our standard absorber integrated with the read-out structure is compared with absorbers deposited after definition of the read-out structure. The latter allows maximising the detection efficiency through thicker layers and different absorber materials. Also, absorbers which are electrically coupled to the readout structure are compared to insulated absorbers which couple to the readout structure by phonon exchange across a thin dielectric layer. New process routes have been designed for all new configurations. Whilst not all these structures have been fabricated successfully yet, our integrated absorber sofar exhibits the best performance, with 2.45 eV FWHM at 400 eV and 16.6 eV FWHM at 5.9 keV.

  12. Adaptive engineering of coherent soft-x-rays by temporal and spatial laser-pulse shaping

    NASA Astrophysics Data System (ADS)

    Pfeifer, Thomas

    2005-03-01

    We demonstrate qualitative amplitude shaping of the coherent soft x-ray spectrum produced in the process of high-harmonic generation. This is accomplished by applying adaptive femtosecond pulse shaping methods. We performed the basic operations of complete spectral control by 1) selective generation of extended parts of the high-harmonic spectra, 2) tunable single harmonic generation and 3) creation of spectral holes (suppression of harmonics) in the plateau region of the spectrum. Our ability to qualitatively ``engineer'' the coherent spectral properties by application of temporal and spatial laser-pulse-shaping methods has immediate consequences for the developing field of attosecond x-ray science. Control over the spectrum is directly related to the control over the attosecond pulse shape as we will show by comparing experiment with simulation. In addition, even more important is the prospect to extend the field of coherent control into the soft x-ray range. In the future, the proposed technique will allow us to directly manipulate electronic motion on its natural attosecond time scale.

  13. Fast plasma discharge capillary design as a high power throughput soft x-ray emission source

    SciTech Connect

    Wyndham, E. S.; Favre, M.; Valdivia, M. P.; Valenzuela, J. C.; Chuaqui, H.; Bhuyan, H.

    2010-09-15

    We present the experimental details and results from a low energy but high repetition rate compact plasma capillary source for extreme ultraviolet and soft x-ray research and applications. Two lengths of capillary are mounted in two versions of a closely related design. The discharge operates in 1.6 and 3.2 mm inner diameter alumina capillaries of lengths 21 and 36 mm. The use of water both as dielectric and as coolant simplifies the compact low inductance design with nanosecond discharge periods. The stored electrical energy of the discharge is approximately 0.5 J and is provided by directly charging the capacitor plates from an inexpensive insulated-gate bipolar transistor in 1 {mu}s or less. We present characteristic argon spectra from plasma between 30 and 300 A as well as temporally resolved x-ray energy fluence in discrete bands on axis. The spectra also allow the level of ablated wall material to be gauged and associated with useful capillary lifetime according to the chosen configuration and energy storage. The connection between the electron beams associated with the transient hollow cathode mechanism, soft x-ray output, capillary geometry, and capillary lifetime is reported. The role of these e-beams and the plasma as measured on-axis is discussed. The relation of the electron temperature and the ionization stages observed is discussed in the context of some model results of ionization in a non-Maxwellian plasma.

  14. Fast plasma discharge capillary design as a high power throughput soft x-ray emission source.

    PubMed

    Wyndham, E S; Favre, M; Valdivia, M P; Valenzuela, J C; Chuaqui, H; Bhuyan, H

    2010-09-01

    We present the experimental details and results from a low energy but high repetition rate compact plasma capillary source for extreme ultraviolet and soft x-ray research and applications. Two lengths of capillary are mounted in two versions of a closely related design. The discharge operates in 1.6 and 3.2 mm inner diameter alumina capillaries of lengths 21 and 36 mm. The use of water both as dielectric and as coolant simplifies the compact low inductance design with nanosecond discharge periods. The stored electrical energy of the discharge is approximately 0.5 J and is provided by directly charging the capacitor plates from an inexpensive insulated-gate bipolar transistor in 1 μs or less. We present characteristic argon spectra from plasma between 30 and 300 Å as well as temporally resolved x-ray energy fluence in discrete bands on axis. The spectra also allow the level of ablated wall material to be gauged and associated with useful capillary lifetime according to the chosen configuration and energy storage. The connection between the electron beams associated with the transient hollow cathode mechanism, soft x-ray output, capillary geometry, and capillary lifetime is reported. The role of these e-beams and the plasma as measured on-axis is discussed. The relation of the electron temperature and the ionization stages observed is discussed in the context of some model results of ionization in a non-Maxwellian plasma.

  15. Soft X-Ray Emission Analysis Of A Pulsed Capillary Discharge Operated In Nitrogen

    NASA Astrophysics Data System (ADS)

    Valdivia, M. P.; Valenzuela, J. C.; Wyndham, E. S.; Favre, M.; Chuaqui, H.; Bhuyan, H.

    2014-05-01

    We present results from a pulsed capillary ns discharge source, operated in Nitrogen and N/He mixtures, in an alumina capillary 2.1mm long with outer diameter of 6.3mm and inner diameter of 1.6mm. The electrical energy stored is 0.5J with peak current of 6kA. Fast charging from an IGBT based pulsed power circuit allows operation at 35-600 Hz with voltages in the range of 18-24kV. Characteristic time-integrated N/He spectra were recorded and analyzed for values of 20-200 Å, with clear evidence of He-like Nitrogen emission at 28.8Å, which represents a possible source for water window soft x-ray microscopy. Filtered diode measurements reveal the influence of axial electron beams, generated by hollow cathode dynamics, on the x-ray emission in the range of 300-450 eV. We discuss optimal voltage applied and pressure conditions for soft x-ray generation. Time-integrated MCP images of a filtered slit-wire system delivered clear evidence of full wall detachment with ~500μm in radial size for the entire emission range and ~200μm for the emission in the 300-450 eV range.

  16. Soft X-ray emission from electron-beam-heated solar flares

    NASA Technical Reports Server (NTRS)

    Mariska, John T.; Zarro, Dominic M.

    1991-01-01

    Using time-dependent numerical simulations and Solar Maximum Mission observations of a solar flare on 1985 January 23, a study is conducted of the ability of an electron-beam-heating model to reproduce the rise phase of a flare as observed in soft X-ray lines of Ca XIX. The electron beam is parameterized by a peak flux, a low-energy cutoff, and a spectral index, and has a time dependence similar to the observed hard X-ray burst. For a spectral index of 6, only models with a low-energy cutoff of 20 keV reproduce the observed peak emission in the Ca XIX line complex. All models with a low-energy cutoff of 15 keV produce too much emission, while all models with a 25-keV cutoff too little emission. None of the models reproduces the temporal behavior of the soft X-ray emission. The electron-beam-heated component is theorized to only represent a small fraction of the energy released in the impulsive phase of this flare.

  17. High-performance Cr/Sc multilayers for the soft x-ray range

    NASA Astrophysics Data System (ADS)

    Yulin, Sergiy A.; Schaefers, Franz; Feigl, Torsten; Kaiser, Norbert

    2004-01-01

    Results of soft x-ray reflection measurements of Cr/Sc multilayer mirrors close to the Sc absorption edge at 3.11 nm are presented. Improvements in the deposition technology and the adjustment of the multilayer period with an accuracy of better than 0.01 nm to this absorption edge enabled a step forward towards soft x-ray mirrors with an adequate reflectance that allow the realization of normal incidence optical components in the water window. In particular, reflectivity measurements performed at the PTB reflectometer at BESSY II in Berlin revealed a reflectivity of R = 14.8% at an incidence angle of θ = 1.5° and R = 15.0% at θ = 5°. Simulation results show that the interface widths between the Cr and Sc nanolayers are less than 0.4 nm. The annealing effect in short-period Cr/Sc multilayers was studied in the temperature range from 50°C to 500°C by X-ray scattering and transmission electron microscopy. Structural and phase transformations and the corresponding changes of the optical properties are presented and discussed.

  18. A soft x-ray transmission grating imaging-spectrometer for the National Ignition Facility

    SciTech Connect

    Moore, A S; Guymer, T M; Kline, J L; Morton, J; Taccetti, M; Lanier, N E; Bentley, C; Workman, J; Peterson, B; Mussack, K; Cowan, J; Prasad, R; Richardson, M; Burns, S; Kalantar, D H; Benedetti, L R; Bell, P; Bradley, D; Hsing, W; Stevenson, M

    2012-05-01

    A soft x-ray transmission grating spectrometer has been designed for use on high energy-density physics experiments at the National Ignition Facility (NIF); coupled to one of the NIF gated x-ray detectors (GXD) it records sixteen time-gated spectra between 250 and 1000eV with 100ps temporal resolution. The trade-off between spectral and spatial resolution leads to an optimized design for measurement of emission around the peak of a 100-300eV blackbody spectrum. Performance qualification results from the NIF, the Trident Laser Facility and VUV beamline at the National Synchrotron Light Source (NSLS), evidence a <100{micro}m spatial resolution in combination with a source-size limited spectral resolution that is <10eV at photon energies of 300eV.

  19. Identifying anthropogenic uranium compounds using soft X-ray near-edge absorption spectroscopy

    SciTech Connect

    Ward, Jesse D.; Bowden, Mark; Tom Resch, C.; Eiden, Gregory C.; Pemmaraju, C. D.; Prendergast, David; Duffin, Andrew M.

    2017-01-01

    Uranium ores mined for industrial use are typically acid-leached to produce yellowcake and then converted into uranium halides for enrichment and purification. These anthropogenic chemical forms of uranium are distinct from their mineral counterparts. The purpose of this study is to use soft X-ray absorption spectroscopy to characterize several common anthropogenic uranium compounds important to the nuclear fuel cycle. Non-destructive chemical analyses of these compounds is important for process and environmental monitoring and X-ray absorption techniques have several advantages in this regard, including element-specificity, chemical sensitivity, and high spectral resolution. Oxygen K-edge spectra were collected for uranyl nitrate, uranyl fluoride, and uranyl chloride, and fluorine K-edge spectra were collected for uranyl fluoride and uranium tetrafluoride. Interpretation of the data is aided by comparisons to calculated spectra. These compounds have unique spectral signatures that can be used to identify unknown samples.

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

    SciTech Connect

    Xiang, D; Stupakov, G.; /SLAC

    2009-05-26

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

  1. A free-standing thin foil bolometer for measuring soft x-ray fluence.

    PubMed

    Hu, Qingyuan; Ning, Jiamin; Ye, Fan; Meng, Shijian; Xu, Rongkun; Yang, Jianlun; Chu, Yanyun; Qin, Yi; Fu, Yuecheng; Chen, Faxin; Xu, Zeping

    2016-10-01

    A free-standing thin foil bolometer for measuring soft x-ray fluence in z-pinch experiments is developed. For the first time, we present the determination of its sensitivity by different methods. The results showed great consistency for the different methods, which confirms the validity of the sensitivity and provides confidence for its application in z-pinch experiments. It should be highlighted that the sensitivity of a free-standing foil bolometer could be calibrated directly using Joule heating without any corrections that will be necessary for a foil bolometer with substrate because of heat loss. The difference of the waveforms between the free-standing foil bolometer and that with substrate is obvious. It reveals that the heat loss to the substrate should be considered for the latter in despite of the short x-ray pulse when the peak value is used to deduce the total deposited energy. The quantitative influence is analyzed through a detailed simulation.

  2. Electronic structure of cobalt doped CdSe quantum dots using soft X-ray spectroscopy

    SciTech Connect

    Joshua T. Wright; Su, Dong; van Buuren, Tony; Meulenberg, Robert W.

    2014-08-21

    The electronic structure and magnetic properties of cobalt doped CdSe quantum dots (QDs) are studied using electron microscopy, soft X-ray spectroscopy, and magnetometry. Magnetometry measurements suggest these QDs are superparamagnetic, contrary to a spin-glass state observed in the bulk analogue. Moreover, the electron microscopy shows well formed QDs, but with cobalt existing as doped into the QD and as unreacted species not contained in the QD. X-ray absorption measurements at the Co L3-edge suggest that changes in spectra features as a function of particle size can be described considering combination of a cobalt ion in a tetrahedral crystal field and an octahedrally coordinated (impurity) phase. With decreasing particle sizes, the impurity phase increases, suggesting that small QDs can be difficult to dope.

  3. Chemical analysis of impurity boron atoms in diamond using soft X-ray emission spectroscopy.

    PubMed

    Muramatsu, Yasuji; Iihara, Junji; Takebe, Toshihiko; Denlinger, Jonathan D

    2008-07-01

    To analyze the local structure and/or chemical states of boron atoms in boron-doped diamond, which can be synthesized by the microwave plasma-assisted chemical vapor deposition method (CVD-B-diamond) and the temperature gradient method at high pressure and high temperature (HPT-B-diamond), we measured the soft X-ray emission spectra in the CK and BK regions of B-diamonds using synchrotron radiation at the Advanced Light Source (ALS). X-ray spectral analyses using the fingerprint method and molecular orbital calculations confirm that boron atoms in CVD-B-diamond substitute for carbon atoms in the diamond lattice to form covalent B-C bonds, while boron atoms in HPT-B-diamond react with the impurity nitrogen atoms to form hexagonal boron nitride. This suggests that the high purity diamond without nitrogen impurities is necessary to synthesize p-type B-diamond semiconductors.

  4. RASOR: an advanced instrument for soft x-ray reflectivity and diffraction.

    PubMed

    Beale, T A W; Hase, T P A; Iida, T; Endo, K; Steadman, P; Marshall, A R; Dhesi, S S; van der Laan, G; Hatton, P D

    2010-07-01

    We report the design and construction of a novel soft x-ray diffractometer installed at Diamond Light Source. The beamline endstation RASOR is constructed for general users and designed primarily for the study of single crystal diffraction and thin film reflectivity. The instrument is comprised of a limited three circle (theta, 2theta, and chi) diffractometer with an additional removable rotation (phi) stage. It is equipped with a liquid helium cryostat, and post-scatter polarization analysis. Motorized motions are provided for the precise positioning of the sample onto the diffractometer center of rotation, and for positioning the center of rotation onto the x-ray beam. The functions of the instrument have been tested at Diamond Light Source, and initial test measurements are provided, demonstrating the potential of the instrument.

  5. Real world issues for the new soft x-ray synchrotron sources

    SciTech Connect

    Kincaid, B.M.

    1991-05-01

    A new generation of synchrotron radiation light sources covering the VUV, soft x-ray and hard x-ray spectral regions is under construction in several countries. They are designed specifically to use periodic magnetic undulators and low-emittance electron or positron beams to produce high-brightness near-diffraction-limited synchrotron radiation beams. An introduction to the properties of undulator radiation is followed by a discussion of some of the challenges to be faced at the new facilities. Examples of predicted undulator output from the Advanced Light Source, a third generation 1--2 GeV storage ring optimized for undulator use, are used to highlight differences from present synchrotron radiation sources, including high beam power, partial coherence, harmonics, and other unusual spectral and angular properties of undulator radiation. 8 refs., 2 figs.

  6. Development of soft X-ray polarized light beamline on Indus-2 synchrotron radiation source

    SciTech Connect

    Phase, D. M. Gupta, Mukul Potdar, S. Behera, L. Sah, R. Gupta, Ajay

    2014-04-24

    This article describes the development of a soft x-ray beamline on a bending magnet source of Indus-2 storage ring (2.5 GeV) and some preliminary results of x-ray absorption spectroscopy (XAS) measurements using the same. The beamline layout is based on a spherical grating monochromator. The beamline is able to accept synchrotron radiation from the bending magnet port BL-1 of the Indus-2 ring with a wide solid angle. The large horizontal and vertical angular acceptance contributes to high photon flux and selective polarization respectively. The complete beamline is tested for ultrahigh vacuum (UHV) ∼ 10{sup −10} mbar. First absorption spectrum was obtained on HOPG graphite foil. Our performance test indicates that modest resolving power has been achieved with adequate photon flux to carry out various absorption experiments.

  7. X-rays and Doppler imaging: Do soft emission and accretion coincide?

    NASA Astrophysics Data System (ADS)

    Wolter, Uwe

    2010-10-01

    Classical T Tauri stars (CTTS) are young, accreting systems. The accretion causes a variable soft X-ray excess and unusual line ratios in the He-like triplets. Accretion signatures can also be seen in optical Doppler images. However, the true correlation of these different signatures only accessible by simultaneous X-ray and ground-based observations has not been studied to date. We propose an 80 ksec XMM-Newton observation covering two full rotations of the CTTS MN Lup; furthermore, we propose simultaneous VLT/UVES spectral observations to obtain a Doppler image of its surface. With its short rotation period and fast rotation, MN Lup is a truly unique target for these observations.

  8. A Soft X-ray Spectrometer using a Highly Dispersive Multilayer Grating

    SciTech Connect

    Warwick, Tony; Padmore, Howard; Voronov, Dmitriy; Yashchuk, Valeriy

    2010-01-31

    There is a need for higher resolution spectrometers as a tool for inelastic x-ray scattering. Currently, resolving power around R = 10,000 is advertised. Measured RIXS spectra are often limited by this instrumental resolution and higher resolution spectrometers using conventional gratings would be prohibitively large. We are engaged in a development program to build blazed multilayer grating structures for diffracting soft x-rays in high order. This leads to spectrometers with dispersion much higher than is possible using metal coated-gratings. The higher dispersion then provides higher resolution and the multilayer gratings are capable of operating away from grazing incidence as required. A spectrometer design is presented with a total length 3.8m and capable of 10{sup 5} resolving power.

  9. A Soft X-ray Spectrometer using a Highly Dispersive Multilayer Grating

    SciTech Connect

    Warwick, Tony; Padmore, Howard; Voronov, Dmitriy; Yashchuk, Valeriy

    2010-06-23

    There is a need for higher resolution spectrometers as a tool for inelastic x-ray scattering. Currently, resolving power around R = 10,000 is advertised. Measured RIXS spectra are often limited by this instrumental resolution and higher resolution spectrometers using conventional gratings would be prohibitively large. We are engaged in a development program to build blazed multilayer grating structures for diffracting soft x-rays in high order. This leads to spectrometers with dispersion much higher than is possible using metal coated-gratings. The higher dispersion then provides higher resolution and the multilayer gratings are capable of operating away from grazing incidence as required. A spectrometer design is presented with a total length 3.8 m and capable of 10{sup 5} resolving power.

  10. Evaluation of surface figure error profile of ellipsoidal mirror for soft x-ray focusing

    NASA Astrophysics Data System (ADS)

    Takeo, Yoko; Saito, Takahiro; Mimura, Hidekazu

    2015-08-01

    It is possible to achieve soft X-ray nanofocusing with a high efficiency and no chromatic aberration by using an ultraprecise ellipsoidal mirror. Surface figure metrology is key in the improvement of surface figure accuracy. In this study, we propose a ptychographic phase retrieval method using a visible light laser to measure the surface figure error profile of an ellipsoidal mirror. We introduce a simple experimental system for ptychographic phase retrieval and demonstrate the basic performance of the proposed system. Obtainable wavefront information provides both the figure error and the alignment of the ellipsoidal mirror that yield the best focusing. This developed method is required for offline adjustments when an ellipsoidal mirror is installed in the beamline of synchrotron radiation or X-ray free-electron laser light sources.

  11. SMM hard X-ray observations of the soft gamma-ray repeater 1806-20

    NASA Technical Reports Server (NTRS)

    Kouveliotou, C.; Norris, J. P.; Cline, T. L.; Dennis, B. R.; Desai, U. D.; Orwig, L. E.

    1987-01-01

    Six bursts from the soft gamma-ray repeater (SGR) 1806-20 have been recorded with the SMM Hard X-ray Burst Spectrometer during a highly active phase in 1983. Rise and decay times of less than 5 ns have been detected. Time profiles of these events indicate low-level emission prior to and after the main peaks. The results suggest that SGRs are distinguished from classical gamma-ray bursts by repetition, softer nonvarying spectra, short durations, simple temporal profiles, and a tendency for source locations to correlate with Population I objects. SGR characteristics differ from those of type I X-ray bursts, but they appear to have similarities with the type II bursts from the Rapid Burster.

  12. Chemical Analysis of Impurity Boron Atoms in Diamond Using Soft X-ray Emission Spectroscopy

    SciTech Connect

    Muramatsu, Yasuji; Iihara, Junji; Takebe, Toshihiko; Denlinger, Jonathan D.

    2008-03-29

    To analyze the local structure and/or chemical states of boron atoms in boron-doped diamond, which can be synthesized by the microwave plasma-assisted chemical vapor deposition method (CVD-B-diamond) and the temperature gradient method at high pressure and high temperature (HPT-B-diamond), we measured the soft X-ray emission spectra in the CK and BK regions of B-diamonds using synchrotron radiation at the Advanced Light Source (ALS). X-ray spectral analyses using the fingerprint method and molecular orbital calculations confirm that boron atoms in CVD-B-diamond substitute for carbon atoms in the diamond lattice to form covalent B-C bonds, while boron atoms in HPT-B-diamond react with the impurity nitrogen atoms to form hexagonal boron nitride. This suggests that the high purity diamond without nitrogen impurities is necessary to synthesize p-type B-diamond semiconductors.

  13. Electrochemical flowcell for in-situ investigations by soft x-ray absorption and emission spectroscopy

    SciTech Connect

    Schwanke, C.; Lange, K. M.; Golnak, R.; Xiao, J.

    2014-10-15

    A new liquid flow-cell designed for electronic structure investigations at the liquid-solid interface by soft X-ray absorption and emission spectroscopy is presented. A thin membrane serves simultaneously as a substrate for the working electrode and solid state samples as well as for separating the liquid from the surrounding vacuum conditions. In combination with counter and reference electrodes this approach allows in-situ studies of electrochemical deposition processes and catalytic reactions at the liquid-solid interface in combination with potentiostatic measurements. As model system in-situ monitoring of the deposition process of Co metal from a 10 mM CoCl{sub 2} aqueous solution by X-ray absorption and emission spectroscopy is presented.

  14. A soft x-ray transmission grating imaging-spectrometer for the National Ignition Facility

    SciTech Connect

    Moore, A. S.; Guymer, T. M.; Morton, J.; Bentley, C.; Stevenson, M.; Kline, J. L.; Taccetti, M.; Lanier, N. E.; Workman, J.; Peterson, B.; Mussack, K.; Cowan, J.; Prasad, R.; Richardson, M.; Burns, S.; Kalantar, D. H.; Benedetti, L. R.; Bell, P.; Bradley, D.; Hsing, W.

    2012-10-15

    A soft x-ray transmission grating spectrometer has been designed for use on high energy-density physics experiments at the National Ignition Facility (NIF); coupled to one of the NIF gated x-ray detectors it records 16 time-gated spectra between 250 and 1000 eV with 100 ps temporal resolution. The trade-off between spectral and spatial resolution leads to an optimized design for measurement of emission around the peak of a 100-300 eV blackbody spectrum. Performance qualification results from the NIF, the Trident Laser Facility and vacuum ultraviolet beamline at the National Synchrotron Light Source, evidence a <100 {mu}m spatial resolution in combination with a source-size limited spectral resolution that is <10 eV at photon energies of 300 eV.

  15. 'Optical' soft x-ray arrays for fluctuation diagnostics in magnetic fusion energy experiments

    SciTech Connect

    Delgado-Aparicio, L.F.; Stutman, D.; Tritz, K.; Finkenthal, M.; Kaita, R.; Roquemore, L.; Johnson, D.; Majeski, R.

    2004-10-01

    We are developing large pixel count, fast ({>=}100 kHz) and continuously sampling soft x-ray (SXR) array for the diagnosis of magnetohydrodynamics (MHD) and turbulent fluctuations in magnetic fusion energy plasmas. The arrays are based on efficient scintillators, high thoughput multiclad fiber optics, and multichannel light amplification and integration. Compared to conventional x-ray diode arrays, such systems can provide vastly increased spatial coverage, and access to difficult locations with small neutron noise and damage. An eight-channel array has been built using columnar CsI:Tl as an SXR converter and a multianode photomultiplier tube as photoamplifier. The overall system efficiency is measured using laboratory SXR sources, while the time response and signal-to-noise performance have been evaluated by recording MHD activity from the spherical tori (ST) Current Drive Experiment-Upgrade and National Spherical Torus Experiment, both at Princeton Plasma Physics Laboratory.

  16. A soft x-ray transmission grating imaging-spectrometer for the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Moore, A. S.; Guymer, T. M.; Kline, J. L.; Morton, J.; Taccetti, M.; Lanier, N. E.; Bentley, C.; Workman, J.; Peterson, B.; Mussack, K.; Cowan, J.; Prasad, R.; Richardson, M.; Burns, S.; Kalantar, D. H.; Benedetti, L. R.; Bell, P.; Bradley, D.; Hsing, W.; Stevenson, M.

    2012-10-01

    A soft x-ray transmission grating spectrometer has been designed for use on high energy-density physics experiments at the National Ignition Facility (NIF); coupled to one of the NIF gated x-ray detectors it records 16 time-gated spectra between 250 and 1000 eV with 100 ps temporal resolution. The trade-off between spectral and spatial resolution leads to an optimized design for measurement of emission around the peak of a 100-300 eV blackbody spectrum. Performance qualification results from the NIF, the Trident Laser Facility and vacuum ultraviolet beamline at the National Synchrotron Light Source, evidence a <100 μm spatial resolution in combination with a source-size limited spectral resolution that is <10 eV at photon energies of 300 eV.

  17. Electrochemical flowcell for in-situ investigations by soft x-ray absorption and emission spectroscopy.

    PubMed

    Schwanke, C; Golnak, R; Xiao, J; Lange, K M

    2014-10-01

    A new liquid flow-cell designed for electronic structure investigations at the liquid-solid interface by soft X-ray absorption and emission spectroscopy is presented. A thin membrane serves simultaneously as a substrate for the working electrode and solid state samples as well as for separating the liquid from the surrounding vacuum conditions. In combination with counter and reference electrodes this approach allows in-situ studies of electrochemical deposition processes and catalytic reactions at the liquid-solid interface in combination with potentiostatic measurements. As model system in-situ monitoring of the deposition process of Co metal from a 10 mM CoCl2 aqueous solution by X-ray absorption and emission spectroscopy is presented.

  18. Circularly polarized soft x-ray diffraction study of helical magnetism in hexaferrite

    NASA Astrophysics Data System (ADS)

    Mulders, A. M.; Lawrence, S. M.; Princep, A. J.; Staub, U.; Bodenthin, Y.; García-Fernández, M.; Garganourakis, M.; Hester, J.; Macquart, R.; Ling, C. D.

    2010-03-01

    Magnetic spiral structures can exhibit ferroelectric moments as recently demonstrated in various multiferroic materials. In such cases the helicity of the magnetic spiral is directly correlated with the direction of the ferroelectric moment and measurement of the helicity of magnetic structures is of current interest. Soft x-ray resonant diffraction is particularly advantageous because it combines element selectivity with a large magnetic cross-section. We calculate the polarization dependence of the resonant magnetic x-ray cross-section (electric dipole transition) for the basal plane magnetic spiral in hexaferrite Ba0.8Sr1.2Zn2Fe12O22 and deduce its domain population using circular polarized incident radiation. We demonstrate there is a direct correlation between the diffracted radiation and the helicity of the magnetic spiral.

  19. Ultrafast molecular dynamics of dissociative ionization in OCS probed by soft x-ray synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Ramadhan, Ali; Wales, Benji; Karimi, Reza; Gauthier, Isabelle; MacDonald, Michael; Zuin, Lucia; Sanderson, Joe

    2016-11-01

    Soft x-rays (90-173 eV) from the 3rd generation Canadian Light Source have been used in conjunction with a multi coincidence time and position sensitive detection apparatus to observe the dissociative ionization of OCS. By varying the x-ray energy we can compare dynamics from direct and Auger ionization processes, and access ionization channels which result in two or three body breakup, from 2+ to 4+ ionization states. We make several new observations for the 3+ state such as kinetic energy release limited by photon energy, and using Dalitz plots we can see evidence of timescale effects between the direct and Auger ionization process for the first time. Finally, using Dalitz plots for OCS4+ we observe for the first time that breakup involving an O2+ ion can only proceed from out of equilibrium nuclear arrangement for S(2p) Auger ionization.

  20. A free-standing thin foil bolometer for measuring soft x-ray fluence

    NASA Astrophysics Data System (ADS)

    Hu, Qingyuan; Ning, Jiamin; Ye, Fan; Meng, Shijian; Xu, Rongkun; Yang, Jianlun; Chu, Yanyun; Qin, Yi; Fu, Yuecheng; Chen, Faxin; Xu, Zeping

    2016-10-01

    A free-standing thin foil bolometer for measuring soft x-ray fluence in z-pinch experiments is developed. For the first time, we present the determination of its sensitivity by different methods. The results showed great consistency for the different methods, which confirms the validity of the sensitivity and provides confidence for its application in z-pinch experiments. It should be highlighted that the sensitivity of a free-standing foil bolometer could be calibrated directly using Joule heating without any corrections that will be necessary for a foil bolometer with substrate because of heat loss. The difference of the waveforms between the free-standing foil bolometer and that with substrate is obvious. It reveals that the heat loss to the substrate should be considered for the latter in despite of the short x-ray pulse when the peak value is used to deduce the total deposited energy. The quantitative influence is analyzed through a detailed simulation.

  1. Soft x-ray laser spectroscopy on trapped highly charged ions at FLASH.

    PubMed

    Epp, S W; López-Urrutia, J R Crespo; Brenner, G; Mäckel, V; Mokler, P H; Treusch, R; Kuhlmann, M; Yurkov, M V; Feldhaus, J; Schneider, J R; Wellhöfer, M; Martins, M; Wurth, W; Ullrich, J

    2007-05-04

    In a proof-of-principle experiment, we demonstrate high-resolution resonant laser excitation in the soft x-ray region at 48.6 eV of the 2 (2)S(1/2) to 2 (2)P(1/2) transition of Li-like Fe23+ ions trapped in an electron beam ion trap by using ultrabrilliant light from Free Electron Laser in Hamburg (FLASH). High precision spectroscopic studies of highly charged ions at this and upcoming x-ray lasers with an expected accuracy gain up to a factor of a thousand, become possible with our technique, thus potentially yielding fundamental insights, e.g., into basic aspects of QED.

  2. Three-dimensional imaging of human stem cells using soft X-ray tomography

    PubMed Central

    Niclis, J. C.; Murphy, S. V.; Parkinson, D. Y.; Zedan, A.; Sathananthan, A. H.; Cram, D. S.; Heraud, P.

    2015-01-01

    Three-dimensional imaging of human stem cells using transmission soft X-ray tomography (SXT) is presented for the first time. Major organelle types—nuclei, nucleoli, mitochondria, lysosomes and vesicles—were discriminated at approximately 50 nm spatial resolution without the use of contrast agents, on the basis of measured linear X-ray absorption coefficients and comparison of the size and shape of structures to transmission electron microscopy (TEM) images. In addition, SXT was used to visualize the distribution of a cell surface protein using gold-labelled antibody staining. We present the strengths of SXT, which include excellent spatial resolution (intermediate between that of TEM and light microscopy), the lack of the requirement for fixative or contrast agent that might perturb cellular morphology or produce imaging artefacts, and the ability to produce three-dimensional images of cells without microtome sectioning. Possible applications to studying the differentiation of human stem cells are discussed. PMID:26063819

  3. The X-ray soft excess in classical T Tauri stars

    NASA Astrophysics Data System (ADS)

    Güdel, M.; Telleschi, A.

    2007-11-01

    Aims:We study an anomaly in the X-ray flux (or luminosity) ratio between the O vii λλ21.6-22.1 triplet and the O viii Lyα line seen in classical T Tauri stars (CTTS). This ratio is unusually high when compared with ratios for main-sequence and non-accreting T Tauri stars (Telleschi et al. 2007c, A&A, 468, 443). We compare these samples to identify the source of the excess. A sample of recently discovered X-ray stars with a soft component attributed to jet emission is also considered. Methods: We discuss data obtained from the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST) project, complemented by data from the published literature. We also present data from the CTTS RU Lup. Results: All CTTS in the sample show an anomalous O vii/O viii flux ratio when compared with WTTS or MS stars. The anomaly is due to an excess of cool, O vii emitting material rather than a deficiency of hotter plasma. The excess plasma must therefore have temperatures of ⪉2 MK. This soft excess does not correlate with UV excesses of CTTS, but seems to be related to the stellar X-ray luminosity. The spectra of the jet-driving TTS do not fit into this context. Conclusions: The soft excess depends both on the presence of accretion streams in CTTS and on magnetic activity. The gas may be shock-heated near the surface, although it may also be heated in the magnetospheric accretion funnels. The soft component of the jet-driving sources is unlikely to be due to the same process.

  4. Development of a compact laser-produced plasma soft X-ray source for radiobiology experiments

    NASA Astrophysics Data System (ADS)

    Adjei, Daniel; Ayele, Mesfin Getachew; Wachulak, Przemyslaw; Bartnik, Andrzej; Wegrzynski, Łukasz; Fiedorowicz, Henryk; Vyšín, Luděk; Wiechec, Anna; Lekki, Janusz; Kwiatek, Wojciech M.; Pina, Ladislav; Davídková, Marie; Juha, Libor

    2015-12-01

    A desk-top laser-produced plasma (LPP) source of soft X-rays (SXR) has been developed for radiobiology research. The source is based on a double-stream gas puff target, irradiated with the focused beam of a commercial Nd:YAG laser. The source has been optimized to get a maximum photon emission from LPP in the X-ray "water window" spectral wavelength range from 2.3 nm (i.e., an absorption edge of oxygen) to 4.4 nm (i.e., an absorption edge of carbon) (280-540 eV in photon energy units) by using argon gas-puff target and spectral filtering by free-standing thin foils. The present source delivers nanosecond pulses of soft X-rays at a fluence of about 4.2 × 103 photons/μm2/pulse on a sample placed inside the vacuum chamber. In this paper, the source design, radiation output characterization measurements and initial irradiation experiments are described. The source can be useful in addressing observations related to biomolecular, cellular and organisms' sensitivity to pulsed radiation in the "water window", where carbon atoms absorb X-rays more strongly than the oxygen, mostly present in water. The combination of the SXR source and the radiobiology irradiation layout, reported in this article, make possible a systematic investigation of relationships between direct and indirect action of ionizing radiation, an increase of a local dose in carbon-rich compartments of the cell (e.g., lipid membranes), an experimental estimation of a particular role of the Auger effect (in particular in carbon atoms) in the damage to biological systems, and the study of ionization/excitation-density (LET - Linear Energy Transfer) and dose-rate effects in radiobiology.

  5. Modular soft x-ray spectrometer for applications in energy sciences and quantum materials

    NASA Astrophysics Data System (ADS)

    Chuang, Yi-De; Shao, Yu-Cheng; Cruz, Alejandro; Hanzel, Kelly; Brown, Adam; Frano, Alex; Qiao, Ruimin; Smith, Brian; Domning, Edward; Huang, Shih-Wen; Wray, L. Andrew; Lee, Wei-Sheng; Shen, Zhi-Xun; Devereaux, Thomas P.; Chiou, Jaw-Wern; Pong, Way-Faung; Yashchuk, Valeriy V.; Gullikson, Eric; Reininger, Ruben; Yang, Wanli; Guo, Jinghua; Duarte, Robert; Hussain, Zahid

    2017-01-01

    Over the past decade, the advances in grating-based soft X-ray spectrometers have revolutionized the soft X-ray spectroscopies in materials research. However, these novel spectrometers are mostly dedicated designs, which cannot be easily adopted for applications with diverging demands. Here we present a versatile spectrometer design concept based on the Hettrick-Underwood optical scheme that uses modular mechanical components. The spectrometer's optics chamber can be used with gratings operated in either inside or outside orders, and the detector assembly can be reconfigured accordingly. The spectrometer can be designed to have high spectral resolution, exceeding 10 000 resolving power when using small source (˜1 μ m) and detector pixels (˜5 μ m) with high line density gratings (˜3000 lines/mm), or high throughput at moderate resolution. We report two such spectrometers with slightly different design goals and optical parameters in this paper. We show that the spectrometer with high throughput and large energy window is particularly useful for studying the sustainable energy materials. We demonstrate that the extensive resonant inelastic X-ray scattering (RIXS) map of battery cathode material LiNi1/3Co1/3Mn1/3O2 can be produced in few hours using such a spectrometer. Unlike analyzing only a handful of RIXS spectra taken at selected excitation photon energies across the elemental absorption edges to determine various spectral features like the localized dd excitations and non-resonant fluorescence emissions, these features can be easily identified in the RIXS maps. Studying such RIXS maps could reveal novel transition metal redox in battery compounds that are sometimes hard to be unambiguously identified in X-ray absorption and emission spectra. We propose that this modular spectrometer design can serve as the platform for further customization to meet specific scientific demands.

  6. Modular soft x-ray spectrometer for applications in energy sciences and quantum materials.

    PubMed

    Chuang, Yi-De; Shao, Yu-Cheng; Cruz, Alejandro; Hanzel, Kelly; Brown, Adam; Frano, Alex; Qiao, Ruimin; Smith, Brian; Domning, Edward; Huang, Shih-Wen; Wray, L Andrew; Lee, Wei-Sheng; Shen, Zhi-Xun; Devereaux, Thomas P; Chiou, Jaw-Wern; Pong, Way-Faung; Yashchuk, Valeriy V; Gullikson, Eric; Reininger, Ruben; Yang, Wanli; Guo, Jinghua; Duarte, Robert; Hussain, Zahid

    2017-01-01

    Over the past decade, the advances in grating-based soft X-ray spectrometers have revolutionized the soft X-ray spectroscopies in materials research. However, these novel spectrometers are mostly dedicated designs, which cannot be easily adopted for applications with diverging demands. Here we present a versatile spectrometer design concept based on the Hettrick-Underwood optical scheme that uses modular mechanical components. The spectrometer's optics chamber can be used with gratings operated in either inside or outside orders, and the detector assembly can be reconfigured accordingly. The spectrometer can be designed to have high spectral resolution, exceeding 10 000 resolving power when using small source (∼1μm) and detector pixels (∼5μm) with high line density gratings (∼3000 lines/mm), or high throughput at moderate resolution. We report two such spectrometers with slightly different design goals and optical parameters in this paper. We show that the spectrometer with high throughput and large energy window is particularly useful for studying the sustainable energy materials. We demonstrate that the extensive resonant inelastic X-ray scattering (RIXS) map of battery cathode material LiNi1/3Co1/3Mn1/3O2 can be produced in few hours using such a spectrometer. Unlike analyzing only a handful of RIXS spectra taken at selected excitation photon energies across the elemental absorption edges to determine various spectral features like the localized dd excitations and non-resonant fluorescence emissions, these features can be easily identified in the RIXS maps. Studying such RIXS maps could reveal novel transition metal redox in battery compounds that are sometimes hard to be unambiguously identified in X-ray absorption and emission spectra. We propose that this modular spectrometer design can serve as the platform for further customization to meet specific scientific demands.

  7. Influence of structural disorder on soft x-ray optical behavior of NbC thin films

    SciTech Connect

    Singh, Amol E-mail: rrcat.amol@gmail.com; Modi, Mohammed H.; Sinha, A. K.; Lodha, G. S.; Rajput, Parasmani

    2015-05-07

    Structural and chemical properties of compound materials are modified, when thin films are formed from bulk materials. To understand these changes, a study was pursued on niobium carbide (NbC) thin films of different thicknesses deposited on Si (100) substrate using ion beam sputtering technique. Optical response of the film was measured in 4–36 nm wavelength region using Indus-1 reflectivity beamline. A discrepancy in soft x-ray performance of NbC film was observed which could not be explained with Henke's tabulated data (see http://henke.lbl.gov/optical{sub c}onstants/ ). In order to understand this, detailed structural and chemical investigations were carried out using x-ray reflectivity, grazing incidence x-ray diffraction, x-ray absorption near edge structure, extended x-ray absorption fine structure, and x-ray photoelectron spectroscopy techniques. It was found that the presence of unreacted carbon and Nb deficiency due to reduced Nb-Nb coordination are responsible for lower soft x-ray reflectivity performance. NbC is an important material for soft x-ray optical devices, hence the structural disorder need to be controlled to achieve the best performances.

  8. Nondestructive single-shot soft x-ray lithography and contact microscopy using a laser-produced plasma source.

    PubMed

    Rosser, R J; Feder, R; Ng, A; Adams, F; Celliers, P; Speer, R J

    1987-10-01

    A toroidal relay optic has been used to overcome the problem of damage caused by debris that has limited previous attempts at soft x-ray lithography and contact microscopy using laser-produced plasma sources. Not only is the specimen preserved, but it is now possible to have a vacuum retaining soft x-ray transparent Si(3)N(4) window as a permanent part of the apparatus, greatly simplifying specimen handling. The exposure times are ~2 ns.

  9. Soft X-ray imaging of thick carbon-based materials using the normal incidence multilayer optics.

    PubMed

    Artyukov, I A; Feschenko, R M; Vinogradov, A V; Bugayev, Ye A; Devizenko, O Y; Kondratenko, V V; Kasyanov, Yu S; Hatano, T; Yamamoto, M; Saveliev, S V

    2010-10-01

    The high transparency of carbon-containing materials in the spectral region of "carbon window" (lambda approximately 4.5-5nm) introduces new opportunities for various soft X-ray microscopy applications. The development of efficient multilayer coated X-ray optics operating at the wavelengths of about 4.5nm has stimulated a series of our imaging experiments to study thick biological and synthetic objects. Our experimental set-up consisted of a laser plasma X-ray source generated with the 2nd harmonics of Nd-glass laser, scandium-based thin-film filters, Co/C multilayer mirror and X-ray film UF-4. All soft X-ray images were produced with a single nanosecond exposure and demonstrated appropriate absorption contrast and detector-limited spatial resolution. A special attention was paid to the 3D imaging of thick low-density foam materials to be used in design of laser fusion targets.

  10. Soft x-ray blazed transmission grating spectrometer with high resolving power and extended bandpass

    NASA Astrophysics Data System (ADS)

    Heilmann, Ralf K.; Bruccoleri, Alexander Robert; Schattenburg, Mark

    2016-04-01

    A number of high priority questions in astrophysics can be addressed by a state-of-the-art soft x-ray grating spectrometer, such as the role of Active Galactic Nuclei in galaxy and star formation, characterization of the Warm-Hot Intergalactic Medium and the “missing baryon” problem, characterization of halos around the Milky Way and nearby galaxies, as well as stellar coronae and surrounding winds and disks. An Explorer-scale, large-area (> 1,000 cm2), high resolving power (R = λ/Δλ > 3,000) soft x-ray grating spectrometer is highly feasible based on Critical-Angle Transmission (CAT) grating technology. Still significantly higher performance can be provided by a CAT grating spectrometer on an X-ray-Surveyor-type mission. CAT gratings combine the advantages of blazed reflection gratings (high efficiency, use of higher diffraction orders) with those of conventional transmission gratings (low mass, relaxed alignment tolerances and temperature requirements, transparent at higher energies) with minimal mission resource requirements. They are high-efficiency blazed transmission gratings that consist of freestanding, ultra-high aspect-ratio grating bars fabricated from silicon-on-insulator (SOI) wafers using advanced anisotropic dry and wet etch techniques. Blazing is achieved through grazing-incidence reflection off the smooth grating bar sidewalls. The reflection properties of silicon are well matched to the soft x-ray band. Nevertheless, CAT gratings with sidewalls made of higher atomic number elements allow extension of the CAT grating principle to higher energies and larger dispersion angles. We show x-ray data from metal-coated CAT gratings and demonstrate efficient blazing to higher energies and larger blaze angles than possible with silicon alone. We also report on measurements of the resolving power of a breadboard CAT grating spectrometer consisting of a Wolter-I slumped-glass focusing mirror pair from Goddard Space Flight Center and CAT gratings, to be

  11. Electronic Properties of Hydrogen Storage Materials with Photon-in/Photon-out Soft-X-Ray Spectroscopy

    SciTech Connect

    Guo, Jinghua

    2008-09-22

    The applications of resonant soft X-ray emission spectroscopy on a variety of carbon systems have yielded characteristic fingerprints. With high-resolution monochromatized synchrotron radiation excitation, resonant inelastic X-ray scattering has emerged as a new source of information about electronic structure and excitation dynamics. Photon-in/photon-out soft-X-ray spectroscopy is used to study the electronic properties of fundamental materials, nanostructure, and complex hydrides and will offer potential in-depth understanding of chemisorption and/or physisorption mechanisms of hydrogen adsorption/desorption capacity and kinetics.

  12. A Simple Synthesis of Alliin and allo-Alliin: X-ray Diffraction Analysis and Determination of Their Absolute Configurations.

    PubMed

    Hakamata, Wataru; Koyama, Ryosuke; Tanida, Mizuki; Haga, Tomomi; Hirano, Takako; Akao, Makoto; Kumagai, Hitomi; Nishio, Toshiyuki

    2015-12-23

    A simple method for the isolation of the bioactive compound alliin from garlic, as well as a method for the synthesis of diastereomerically pure alliin and allo-alliin on a preparative laboratory scale, was developed. The absolute configuration of the sulfur atom in alliin and allo-alliin was assigned on the basis of enzyme reactivity, optical rotatory dispersion, and circular dichroism analyses. A comparison of the results from these analyses, in combination with an X-ray diffraction study on a protected allo-alliin derivative, revealed S and R configurations of the sulfur atoms in alliin and allo-alliin, respectively. In addition, the same (1)H NMR spectrum was observed for synthetic and natural alliin. The absolute configuration of natural alliin was assigned for the first time on the basis of the NMR spectrum and X-ray coordinates.

  13. Development of a soft x-ray plasma camera with a Fresnel zone plate to image laser produced plasmas

    NASA Astrophysics Data System (ADS)

    Kado, M.; Mori, M.; Nishiuchi, M.; Ishino, M.; Kawachi, T.

    2009-09-01

    A soft x-ray plasma camera operated at 3.35nm in the water window x-ray region is developed and demonstrated imaging gas jet plasmas of several spices produced with a 10TW Ti: sapphire laser. The plasma camera consists of a 300nm thick Ag/Ti/Si3N4 x-ray band pass filter with bandwidth of 1.43nm to cut visible light and also to reduce colour aberration of the Fresnel zone plate, a Fresnel zone plate with diameter of 1mm and outermost zone width of 300nm, and a soft x-ray CCD camera. The magnification of the plasma camera is 10. The soft x-ray plasma camera powered by a Fresnel zone plate is a very powerful tool to observe laser produced plasmas since it is 1000 times brighter and has 5 times higher spatial resolution comparing ordinary x-ray pinhole camera. The soft x-ray images of helium, nitrogen, argon, krypton, and xenon gas jet plasmas are obtained changing gas pressure from 0.01MPa to 1MPa.

  14. Dynamic wetting on soft substrates studied by x-ray imaging

    NASA Astrophysics Data System (ADS)

    Park, Su Ji; Je, Jung Ho

    2014-11-01

    When a droplet sits on a soft surface, the surface tension of the droplet deforms the underlying material, creating a wetting ridge. Wetting ridge formation affects not only static wetting but also dynamic wetting behaviors. However, the underlying mechanisms are still largely unexplored mostly due to limitations in observation. Here, we directly visualize wetting ridges in real-time during spreading of a liquid drop using x-ray microscopy with high spatial and temporal resolutions. We clearly show that ridge-growth dynamics is closely linked to spreading behaviors. Interestingly, we reveal that the bending of a ridge cusp enhances the pinning force. We believe that our results would shed light on understanding of dynamic wetting behaviors on soft solids (e.g. contact angle hysteresis or evaporation) and be potentially important to interpret complex biological processes on or in soft tissues (e.g. cell-substrate interactions).

  15. A SOFT X-RAY REVERBERATION LAG IN THE AGN ESO 113-G010

    SciTech Connect

    Cackett, E. M.; Fabian, A. C.; Kara, E.; Zogbhi, A.; Reynolds, C.; Uttley, P.

    2013-02-10

    Reverberation lags have recently been discovered in a handful of nearby, variable active galactic nuclei (AGNs). Here, we analyze a {approx}100 ks archival XMM-Newton observation of the highly variable AGN, ESO 113-G010, in order to search for lags between hard, 1.5-4.5 keV, and soft, 0.3-0.9 keV, energy X-ray bands. At the lowest frequencies available in the light curve ({approx}< 1.5 Multiplication-Sign 10{sup -4} Hz), we find hard lags where the power-law-dominated hard band lags the soft band (where the reflection fraction is high). However, at higher frequencies in the range (2-3) Multiplication-Sign 10{sup -4} Hz we find a soft lag of -325 {+-} 89 s. The general evolution from hard to soft lags as the frequency increases is similar to other AGNs where soft lags have been detected. We interpret this soft lag as due to reverberation from the accretion disk, with the reflection component responding to variability from the X-ray corona. For a black hole mass of 7 Multiplication-Sign 10{sup 6} M{sub Sun} this corresponds to a light-crossing time of {approx}9 R{sub g} /c; however, dilution effects mean that the intrinsic lag is likely longer than this. Based on recent black hole mass scaling for lag properties, the lag amplitude and frequency are more consistent with a black hole a few times more massive than the best estimates, though flux-dependent effects could easily add scatter this large.

  16. X-ray variability of Cygnus X-1 in its soft state

    NASA Technical Reports Server (NTRS)

    Cui, W.; Zhang, S. N.; Jahoda, K.; Focke, W.; Swank, J.; Heindl, W. A.; Rothschild, R. E.

    1997-01-01

    Observations from the Rossi X-ray Timing Explorer (RXTE) of Cyg X-1 in the soft state and during the soft to hard transition are examined. The results of this analysis confirm previous conclusions that for this source there is a settling period (following the transition from the hard to soft state during which the low energy spectrum varies significantly, while the high energy portion changes little) during which the source reaches nominal soft state brightness. This behavior can be characterized by a soft low energy spectrum and significant low frequency 1/f noise and white noise on the power density spectrum, which becomes softer upon reaching the true soft state. The low frequency 1/f noise is not observed when Cyg X-1 is in the hard state, and therefore appears to be positively correlated with the disk mass accretion rate. The difference in the observed spectral and timing properties between the hard and soft states is qualitatively consistent with a fluctuating corona model.

  17. Surface Roughness of Stainless Steel Bender Mirrors for FocusingSoft X-rays

    SciTech Connect

    Yashchuk, Valeriy V.; Gullikson, Eric M.; Howells, Malcolm R.; Irick, Steve C.; MacDowell, Alastair A.; McKinney, Wayne R.; Salmassi,Farhad; Warwick, Tony; Metz, James P.; Tonnessen, Thomas W.

    2005-10-11

    We have used polished stainless steel as a mirror substrate to provide focusing of soft x-rays in grazing incidence reflection. The substrate is bent to an elliptical shape with large curvature and high stresses in the substrate require a strong elastic material. Conventional material choices of silicon or of glass will not withstand the stress required. The use of steel allows the substrates to be polished and installed flat, using screws in tapped holes. The ultra-high-vacuum bender mechanism is motorized and computer controlled. These mirrors are used to deliver focused beams of soft x-rays onto the surface of a sample for experiments at the Advanced Light Source (ALS). They provide an illumination field that can be as small as the mirror demagnification allows, for localized study, and can be enlarged, under computer control,for survey measurements over areas of the surface up to several millimeters. The critical issue of the quality of the steel surface, polished and coated with gold, which limits the minimum achievable focused spot size is discussed in detail. Comparison is made to a polished, gold coated, electroless nickel surface, which provides a smoother finish. Surface measurements are presented as power spectral densities, as a function of spatial frequency. The surface height distributions measured with an interferometric microscope, and complemented by atomic force microscope measurements, are used to compute power spectral densities and then to evaluate the surface roughness. The effects of roughness in reducing the specular reflectivity are verified by soft x-ray measurements.

  18. Comparison of a CCD and an APS for soft X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Stewart, Graeme; Bates, R.; Blue, A.; Clark, A.; Dhesi, S. S.; Maneuski, D.; Marchal, J.; Steadman, P.; Tartoni, N.; Turchetta, R.

    2011-12-01

    We compare a new CMOS Active Pixel Sensor (APS) to a Princeton Instruments PIXIS-XO: 2048B Charge Coupled Device (CCD) with soft X-rays tested in a synchrotron beam line at the Diamond Light Source (DLS). Despite CCDs being established in the field of scientific imaging, APS are an innovative technology that offers advantages over CCDs. These include faster readout, higher operational temperature, in-pixel electronics for advanced image processing and reduced manufacturing cost. The APS employed was the Vanilla sensor designed by the MI3 collaboration and funded by an RCUK Basic technology grant. This sensor has 520 x 520 square pixels, of size 25 μm on each side. The sensor can operate at a full frame readout of up to 20 Hz. The sensor had been back-thinned, to the epitaxial layer. This was the first time that a back-thinned APS had been demonstrated at a beam line at DLS. In the synchrotron experiment soft X-rays with an energy of approximately 708 eV were used to produce a diffraction pattern from a permalloy sample. The pattern was imaged at a range of integration times with both sensors. The CCD had to be operated at a temperature of -55°C whereas the Vanilla was operated over a temperature range from 20°C to -10°C. We show that the APS detector can operate with frame rates up to two hundred times faster than the CCD, without excessive degradation of image quality. The signal to noise of the APS is shown to be the same as that of the CCD at identical integration times and the response is shown to be linear, with no charge blooming effects. The experiment has allowed a direct comparison of back thinned APS and CCDs in a real soft x-ray synchrotron experiment.

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

    SciTech Connect

    Rosfjord, Kristine Marie

    2004-01-01

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

  20. A liquid flatjet system for solution phase soft-x-ray spectroscopy

    PubMed Central

    Ekimova, Maria; Quevedo, Wilson; Faubel, Manfred; Wernet, Philippe; Nibbering, Erik T. J.

    2015-01-01

    We present a liquid flatjet system for solution phase soft-x-ray spectroscopy. The flatjet set-up utilises the phenomenon of formation of stable liquid sheets upon collision of two identical laminar jets. Colliding the two single water jets, coming out of the nozzles with 50 μm orifices, under an impact angle of 48° leads to double sheet formation, of which the first sheet is 4.6 mm long and 1.0 mm wide. The liquid flatjet operates fully functional under vacuum conditions (<10−3 mbar), allowing soft-x-ray spectroscopy of aqueous solutions in transmission mode. We analyse the liquid water flatjet thickness under atmospheric pressure using interferomeric or mid-infrared transmission measurements and under vacuum conditions by measuring the absorbance of the O K-edge of water in transmission, and comparing our results with previously published data obtained with standing cells with Si3N4 membrane windows. The thickness of the first liquid sheet is found to vary between 1.4–3 μm, depending on the transverse and longitudinal position in the liquid sheet. We observe that the derived thickness is of similar magnitude under 1 bar and under vacuum conditions. A catcher unit facilitates the recycling of the solutions, allowing measurements on small sample volumes (∼10 ml). We demonstrate the applicability of this approach by presenting measurements on the N K-edge of aqueous NH4+. Our results suggest the high potential of using liquid flatjets in steady-state and time-resolved studies in the soft-x-ray regime. PMID:26798824

  1. Temporal Young's interference experiment by attosecond double and triple soft-x-ray pulses

    SciTech Connect

    Ishikawa, Kenichi L.

    2006-08-15

    We study a temporal version of Young's interference experiment by attosecond soft-x-ray pulses. The photoelectron energy spectra by attosecond double pulses exhibit an interference pattern, since we have no information on which pulse has generated the electron. We can re-establish the 'which-way' information and control the interference visibility by changing the electron's momentum with phase-stabilized laser pulses, by an amount depending on the time of ionization. Moreover, if we use a triple pulse, we can realize a situation where the electron passes through a single and a double slit simultaneously to the same direction and is observed by the same detector.

  2. Measurements of laser generated soft X-ray emission from irradiated gold foils

    NASA Astrophysics Data System (ADS)

    Davis, J. S.; Frank, Y.; Raicher, E.; Fraenkel, M.; Keiter, P. A.; Klein, S. R.; Drake, R. P.; Shvarts, D.

    2016-11-01

    Soft x-ray emission from laser irradiated gold foils was measured at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6 ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

  3. Grazing incidence telescopes - A new class for soft X-ray and EUV spectroscopy

    NASA Technical Reports Server (NTRS)

    Hettrick, M. C.; Bowyer, S.

    1984-01-01

    A new class of grazing incidence telescopes is identified, and its advantages for stellar spectroscopy are discussed. In particular, three types of telescope geometry consisting of a primary and a secondary, both at grazing incidence, are proposed. Type I delivers a converging beam having a real focus; type II delivers a diverging beam from a virtual focus, and type III delivers a collimated beam concentrated relative to the primary aperture. The three telescope types are shown to possess unique properties which improve the efficiency and shorten the length of soft X-ray/EUV spectrographs.

  4. Soft-x-ray free-electron-laser interaction with materials

    SciTech Connect

    Hau-Riege, Stefan P.; London, Richard A.; Chapman, Henry N.; Bergh, Magnus

    2007-10-15

    Soft-x-ray free-electron lasers have enabled materials studies in which structural information is obtained faster than the relevant probe-induced damage mechanisms. We present a continuum model to describe the damage process based on hot-dense plasma theory, which includes a description of the energy deposition in the samples, the subsequent dynamics of the sample, and the detector signal. We compared the model predictions with experimental data and mostly found reasonable agreement. In view of future free-electron-laser performance, the model was also used to predict damage dynamics of samples and optical elements at shorter wavelengths and larger photon fluences than currently available.

  5. Coronal Diagnostics with Coordinated Radio and EUV/Soft X-Ray Observations

    NASA Astrophysics Data System (ADS)

    Brosius, Jeffrey W.

    2004-09-01

    A brief review is provided of what has been learned about the solar corona from existing coordinated radio and EUV (or soft X-ray) observations. Topics include: introduction to radio thermal bremsstrahlung and thermal gyroemission; two-dimensional coronal magnetography measurements; measurements of coronal elemental abundances; measurements of physical properties of quasitransverse (QT) layers in the coronal magnetic field; and three-dimensional coronal magnetography measurements (the primary subject of this Chapter). Results from these studies are used to help focus on coronal diagnostics that can be performed with similar coordinated observations involving FASR, as well as to recommend FASR instrument requirements.

  6. EUV/soft x-ray spectra for low B neutron stars

    NASA Technical Reports Server (NTRS)

    Romani, Roger W.; Rajagopal, Mohan; Rogers, Forrest J.; Iglesias, Carlos A.

    1995-01-01

    Recent ROSAT and EUVE detections of spin-powered neutron stars suggest that many emit 'thermal' radiation, peaking in the EUV/soft X-ray band. These data constrain the neutron stars' thermal history, but interpretation requires comparison with model atmosphere computations, since emergent spectra depend strongly on the surface composition and magnetic field. As recent opacity computations show substantial change to absorption cross sections at neutron star photospheric conditions, we report here on new model atmosphere computations employing such data. The results are compared with magnetic atmosphere models and applied to PSR J0437-4715, a low field neutron star.

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

    DOEpatents

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

    2013-06-11

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

  8. Oxidation preventative capping layer for deep-ultra-violet and soft x-ray multilayers

    DOEpatents

    Prisbrey, Shon T.

    2004-07-06

    The invention uses iridium and iridium compounds as a protective capping layer on multilayers having reflectivity in the deep ultra-violet to soft x-ray regime. The iridium compounds can be formed in one of two ways: by direct deposition of the iridium compound from a prepared target or by depositing a thin layer (e.g., 5-50 angstroms) of iridium directly onto an element. The deposition energy of the incoming iridium is sufficient to activate the formation of the desired iridium compound. The compounds of most interest are iridium silicide (IrSi.sub.x) and iridium molybdenide (IrMo.sub.x).

  9. Measurements of laser generated soft X-ray emission from irradiated gold foils

    DOE PAGES

    Davis, J. S.; Frank, Y.; Raicher, E.; ...

    2016-08-22

    We measured soft x-ray emission from laser irradiated gold foils at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

  10. Soft X-ray spectromicroscopy and its application to semiconductor microstructure characterization

    SciTech Connect

    Gozzo, F.; Franck, K.; Howells, M.R.; Hussain, Z.

    1996-05-01

    The universal trend towards device miniaturization has driven the semiconductor industry to develop sophisticated and complex instrumentation for the characterization of microstructures. Many significant problems of relevance to the semiconductor industry cannot be solved with conventional analysis techniques, but can be addressed with soft x-ray spectromicroscopy. An active spectromicroscopy program is being developed at the Advanced Light Source, attracting both the semiconductor industry and the materials science academic community. Examples of spectromicroscopy techniques are presented. An ALS {mu}-XPS spectromicroscopy project is discussed, involving the first microscope completely dedicated and designed for microstructure analysis on patterned silicon wafers.

  11. Design Concept and Performance of the Soft X-ray Beamline HiSOR-BL14

    SciTech Connect

    Sawada, M.; Namatame, H.; Yaji, K.; Nagira, M.; Kimura, A.; Taniguchi, M.

    2007-01-19

    The soft X-ray beamline HiSOR-BL14 has been constructed at Hiroshima Synchrotron Radiation Center, aimed at absorption spectroscopy and photoelectron spectroscopy with linearly and circularly polarized light. The beamline layout is based on a Dragon-type design with a spherical grating monochromator. The beamline is able to accept synchrotron radiation from the bending magnet part of the HiSOR ring with a wide solid angle. The large horizontal angular acceptance and vertical one contribute to high photon flux and controllability of light polarization, respectively. Our performance test indicates that high resolving power has been achieved with sufficient photon flux to carry out spectroscopic experiments.

  12. Development of Computer Tomography System for the Soft X-ray Microscope at Ritsumeikan University

    SciTech Connect

    Ohigashi, T.; Fujii, H.; Usui, K.; Namba, H.; Mizutani, H.; Takemoto, K.; Kihara, H.

    2011-09-09

    A synchrotron-based full-field imaging soft x-ray microscope was tuned appropriately to perform computer tomography. The contrast and focal depth of the optical system were evaluated by using a Fresnel zone plate as a test object of variable spatial frequency. A focal depth of 15 {mu}m was obtained at the spatial frequency of 4.3 {mu}m{sup -1} according to Rayleigh's criterion. As a first trial of three-dimensional observation using this system, the cerebral cortex of the brain of a mouse, trimmed to a columnar shape by focused ion beam milling, was studied using a wavelength of 1.87-nm.

  13. Soft X-ray microscope with nanometer spatial resolution and its applications

    NASA Astrophysics Data System (ADS)

    Wachulak, P. W.; Torrisi, A.; Bartnik, A.; Wegrzynski, L.; Fok, T.; Patron, Z.; Fiedorowicz, H.

    2016-12-01

    A compact size microscope based on nitrogen double stream gas puff target soft X-ray source, which emits radiation in water-window spectral range at the wavelength of λ = 2.88 nm is presented. The microscope employs ellipsoidal grazing incidence condenser mirror for sample illumination and silicon nitride Fresnel zone plate objective for object magnification and imaging. The microscope is capable of capturing water-window images of objects with 60 nm spatial resolution and exposure time as low as a few seconds. Details about the microscopy system as well as some examples of different applications from various fields of science, are presented and discussed.

  14. Flare onsets in hard and soft X-rays. [magnetic energy conversion in sun

    NASA Technical Reports Server (NTRS)

    Machado, Marcos E.; Orwig, Larry E.; Antonucci, Ester

    1986-01-01

    It is shown that the onset of solar flares, within about 2 min or less before the impulsive peaks, is characterized by an increase in high-energy emission at E less than 100 keV, and strong broadening of soft X-ray lines characteristic of the 10-million-K plasma already present at this stage. The observations are interpreted in terms of the early signature of energy release, during a phase preceding the instability that leads to strong particle acceleration.

  15. Self-regulated propagation of intense infrared pulses in elongated soft-x-ray plasma amplifiers

    NASA Astrophysics Data System (ADS)

    Oliva, Eduardo; Depresseux, Adrien; Tissandier, Fabien; Gautier, Julien; Sebban, Stéphane; Maynard, Gilles

    2015-08-01

    Increasing the electron density of collisionally pumped plasma-based soft-x-ray lasers offers promising opportunities to deliver ultrashort pulses. However, strong nonlinear effects, such as overionization-induced refraction and self-focusing, hinder the propagation of the laser beam and thus the generation of elongated volume of lasing ions to be pumped. Using a particle-in-cell code and a ray-tracing model we demonstrate that optically preformed waveguides allow for addressing those issues through a self-regulation regime between self-focusing and overionization processes. As a result, guiding intense pulses over several millimeters leads to the implementation of saturated plasma amplifiers.

  16. Use of graphite epoxy composites in the Solar-A Soft X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Jurcevich, B. K.; Bruner, M. E.

    1990-01-01

    This paper describes the use of composite materials in the Soft X-Ray Telescope (SXT). One of the primary structural members of the telescope is a graphite epoxy metering tube. The metering tube maintains the structural stability of the telescope during launch as well as the focal length through various environmental conditions. The graphite epoxy metering tube is designed to have a negative coefficient of thermal expansion to compensate for the positive expansion of titanium structural supports. The focus is maintained to + or - 0.001 inch by matching the CTE of the composite tube to the remaining structural elements.

  17. A magnetizing system for dichroism measurements in soft x-ray emission excited by synchrotron radiation

    SciTech Connect

    Dallera, C.; Ghiringhelli, G.; Braicovich, L.

    1996-02-01

    We present the design and performance of a magnetic circuit suitable for magnetizing solid samples in the measurements of soft x-ray emission dichroism excited by synchrotron radiation. The system allows a variety of samples to be magnetized and satisfies the rather stringent geometrical constraints due to the need for minimizing the effect of photon self-absorption by the sample. The magnetic circuit is ultrahigh vacuum compatible, can reach about 2800 G, and allows fine adjustment of sample position. {copyright} {ital 1996 American Institute of Physics.}

  18. Two-dimensional Detector for High Resolution Soft X-ray Imaging

    SciTech Connect

    Ejima, Takeo; Ogasawara, Shodo; Hatano, Tadashi; Yanagihara, Mihiro; Yamamoto, Masaki

    2010-06-23

    A new two-dimensional (2D) detector for detecting soft X-ray (SX) images was developed. The detector has a scintillator plate to convert a SX image into a visible (VI) one, and a relay optics to magnify and detect the converted VI image. In advance of the fabrication of the detector, quantum efficiencies of scintillators were investigated. As a result, a Ce:LYSO single crystal on which Zr thin film was deposited was used as an image conversion plate. The spatial resolution of fabricated detector is 3.0 {mu}m, and the wavelength range which the detector has sensitivity is 30-6 nm region.

  19. Resonant inelastic soft x-ray scattering at double core excitations in solid LiCl

    SciTech Connect

    Agaaker, Marcus; Ahuja, Rajeev; Soederstroem, Johan; Rubensson, Jan-Erik; Kaeaembre, Tanel; Glover, Chris; Schmitt, Thorsten; Mattesini, Maurizio

    2006-06-15

    Inelastic soft x-ray scattering in LiCl, resonantly enhanced at states with two Li 1s vacancies, is investigated. States in which both excited electrons are localized during the double core hole lifetime, in which one of the electrons delocalize, as well as triply excited states in which the double core excitation is accompanied by a valence-to-conduction band excitation, contribute to the scattering. The angular momentum symmetry of the involved states and the vibronic coupling during the scattering process are reflected in the angular anisotropy. The effect on the local electronic structure of multiple core holes is theoretically studied by means of supercell band calculations.

  20. Laser heated gas-jet: a soft x-ray source

    SciTech Connect

    Charatis, G.; Slater, D.C.; Mayer, F.J.; Tarvin, J.A.; Busch, G.E.; Sullivan, D.; Musinski, D.; Matthews, D.L.; Koppel, L.

    1981-01-01

    The laser irradiated gas jet developed to study collective scattering processes has proven to be a useful soft x-ray source. It is a reproducible and stationary source with large yield and plasma properties characterized by conventional diagnostic techniques. With a density gradient initially set by orifice size and gas pressure, a short (approx. 100 to 1000 psec) pulse operating at 1.05 ..mu..m (or 0.53 ..mu..m) is focused coaxially upstream into the jet producing a moderate temperature plasma. X-ray pinhole photographs show an axially symmetric radiating plume located at the electron density critical surface. The density gradient is obtained by holographic interferometry using a 0.26 ..mu..m wavelength probe pulse. The scale length of approx. 100 to 200 ..mu..m is measured by 2..omega.. and 3/2..omega.. photography. Electron temperatures are determined by using spatially resolving x-ray crystal spectroscopy to record and analyze line emission from H- and He-like configurations. Electron temperatures from approx. 200 to 700 eV were observed at critical electron densities as high as N/sub cr/ approx. 4 x 10/sup 21/ cm/sup -3/ for gases of hydrogen, nitrogen, neon, argon, and SF/sub 6/.