Advances in X-ray optics: From metrology characterization to wavefront sensing-based optimization of active optics

DOE PAGES

Cocco, Daniele; Idir, Mourad; Morton, Daniel; ...

2018-03-20

Experiments using high brightness X-rays are on the forefront of science due to the vast variety of knowledge they can provide. New Synchrotron Radiation (SR) and Free Electron Laser (FEL) light sources provide unique tools for advanced studies using X-rays. Top-level scientists from around the world are attracted to these beamlines to perform unprecedented experiments. High brightness, low emittance light sources allow beamline scientists the possibility to dream up cutting-edge experimental stations. X-ray optics play a key role in bringing the beam from the source to the experimental stations. This paper explores the recent developments in X-ray optics. It touchesmore » on simulations, diagnostics, metrology and adaptive optics, giving an overview of the role X-ray optics have played in the recent past. It will also touch on future developments for one of the most active field in the X-ray science.« less

Advances in X-ray optics: From metrology characterization to wavefront sensing-based optimization of active optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cocco, Daniele; Idir, Mourad; Morton, Daniel

Experiments using high brightness X-rays are on the forefront of science due to the vast variety of knowledge they can provide. New Synchrotron Radiation (SR) and Free Electron Laser (FEL) light sources provide unique tools for advanced studies using X-rays. Top-level scientists from around the world are attracted to these beamlines to perform unprecedented experiments. High brightness, low emittance light sources allow beamline scientists the possibility to dream up cutting-edge experimental stations. X-ray optics play a key role in bringing the beam from the source to the experimental stations. This paper explores the recent developments in X-ray optics. It touchesmore » on simulations, diagnostics, metrology and adaptive optics, giving an overview of the role X-ray optics have played in the recent past. It will also touch on future developments for one of the most active field in the X-ray science.« less

Development of X-ray CCD camera based X-ray micro-CT system

NASA Astrophysics Data System (ADS)

Sarkar, Partha S.; Ray, N. K.; Pal, Manoj K.; Baribaddala, Ravi; Agrawal, Ashish; Kashyap, Y.; Sinha, A.; Gadkari, S. C.

2017-02-01

Availability of microfocus X-ray sources and high resolution X-ray area detectors has made it possible for high resolution microtomography studies to be performed outside the purview of synchrotron. In this paper, we present the work towards the use of an external shutter on a high resolution microtomography system using X-ray CCD camera as a detector. During micro computed tomography experiments, the X-ray source is continuously ON and owing to the readout mechanism of the CCD detector electronics, the detector registers photons reaching it during the read-out period too. This introduces a shadow like pattern in the image known as smear whose direction is defined by the vertical shift register. To resolve this issue, the developed system has been incorporated with a synchronized shutter just in front of the X-ray source. This is positioned in the X-ray beam path during the image readout period and out of the beam path during the image acquisition period. This technique has resulted in improved data quality and hence the same is reflected in the reconstructed images.

TH-F-209-01: Pitfalls: Reliability and Performance of Diagnostic X-Ray Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behling, R.

Purpose: Performance and reliability of medical X-ray tubes for imaging are crucial from an ethical, clinical and economic perspective. This lecture will deliver insight into the aspects to consider during the decision making process to invest in X-ray imaging equipment. Outdated metric still hampers realistic product comparison. It is time to change this and to comply with latest standards, which consider current technology. Failure modes and ways to avoid down-time of the equipment shall be discussed. In view of the increasing number of interventional procedures and the hazards associated with ionizing radiation, toxic contrast agents, and the combination thereof, themore » aspect of system reliability is of paramount importance. Methods: A comprehensive picture of trends for different modalities (CT, angiography, general radiology) has been drawn and led to the development of novel X-ray tube technology. Results: Recent X-ray tubes feature enhanced reliability and unprecedented performance. Relevant metrics for product comparison still have to be implemented in practice. Conclusion: The speed of scientific and industrial development of new diagnostic and therapeutic X-ray sources remains tremendous. Still, users suffer from gaps between desire and reality in day-to-day diagnostic routine. X-ray sources are still limiting cutting-edge medical procedures. Side-effects of wear and tear, limitations of the clinical work flow, costs, the characteristics of the X-ray spectrum and others topics need to be further addressed. New applications and modalities, like detection-based color-resolved X-ray and phase-contrast / dark-field imaging will impact the course of new developments of X-ray sources. Learning Objectives: Understand the basic requirements on medical diagnostic X-ray sources per modality Learn to select the optimal equipment employing state-of-the-art metric Know causes of failures, depending on the way X-ray sources are operated Understand methods to remediate critical situations Understand the meaning of different warranty models I am employee of Royal Philips; R. Behling, No external funding. I am employee of Royal Philips.« less

TH-F-209-00: Pitfalls: Reliability and Performance of Diagnostic X-Ray Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Purpose: Performance and reliability of medical X-ray tubes for imaging are crucial from an ethical, clinical and economic perspective. This lecture will deliver insight into the aspects to consider during the decision making process to invest in X-ray imaging equipment. Outdated metric still hampers realistic product comparison. It is time to change this and to comply with latest standards, which consider current technology. Failure modes and ways to avoid down-time of the equipment shall be discussed. In view of the increasing number of interventional procedures and the hazards associated with ionizing radiation, toxic contrast agents, and the combination thereof, themore » aspect of system reliability is of paramount importance. Methods: A comprehensive picture of trends for different modalities (CT, angiography, general radiology) has been drawn and led to the development of novel X-ray tube technology. Results: Recent X-ray tubes feature enhanced reliability and unprecedented performance. Relevant metrics for product comparison still have to be implemented in practice. Conclusion: The speed of scientific and industrial development of new diagnostic and therapeutic X-ray sources remains tremendous. Still, users suffer from gaps between desire and reality in day-to-day diagnostic routine. X-ray sources are still limiting cutting-edge medical procedures. Side-effects of wear and tear, limitations of the clinical work flow, costs, the characteristics of the X-ray spectrum and others topics need to be further addressed. New applications and modalities, like detection-based color-resolved X-ray and phase-contrast / dark-field imaging will impact the course of new developments of X-ray sources. Learning Objectives: Understand the basic requirements on medical diagnostic X-ray sources per modality Learn to select the optimal equipment employing state-of-the-art metric Know causes of failures, depending on the way X-ray sources are operated Understand methods to remediate critical situations Understand the meaning of different warranty models I am employee of Royal Philips; R. Behling, No external funding. I am employee of Royal Philips.« less

X-ray source development for EXAFS measurements on the National Ignition Facility.

PubMed

Coppari, F; Thorn, D B; Kemp, G E; Craxton, R S; Garcia, E M; Ping, Y; Eggert, J H; Schneider, M B

2017-08-01

Extended X-ray absorption Fine Structure (EXAFS) measurements require a bright, spectrally smooth, and broad-band x-ray source. In a laser facility, such an x-ray source can be generated by a laser-driven capsule implosion. In order to optimize the x-ray emission, different capsule types and laser irradiations have been tested at the National Ignition Facility (NIF). A crystal spectrometer is used to disperse the x-rays and high efficiency image plate detectors are used to measure the absorption spectra in transmission geometry. EXAFS measurements at the K-edge of iron at ambient conditions have been obtained for the first time on the NIF laser, and the requirements for optimization have been established.

Exposure Dose Reconstruction from EPR Spectra of Tooth Enamel Exposed to the Combined Effect of X-rays and Gamma Radiation

NASA Astrophysics Data System (ADS)

Kirillov, V. A.; Kuchuro, J. I.

2014-09-01

We have used EPR dosimetry on tooth enamel to show that the combined effect of x-rays with effective energy 34 keV and gamma radiation with average energy 1250 keV leads to a significant increase in the reconstructed absorbed dose compared with the applied dose from a gamma source or from an x-ray source or from both sources of electromagnetic radiation. In simulation experiments, we develop an approach to estimating the contribution of diagnostic x-rays to the exposure dose formed in the tooth enamel by the combined effect of x-rays and gamma radiation.

Bright x-ray stainless steel K-shell source development at the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

May, M. J.; Fournier, K. B.; Colvin, J. D.

2015-06-15

High x-ray conversion efficiency (XRCE) K-shell sources are being developed for high energy density experiments for use as backlighters and for the testing of materials exposed to high x-ray fluxes and fluences. Recently, sources with high XRCE in the K-shell x-ray energy range of iron and nickel were investigated at the National Ignition Facility (NIF). The x-ray conversion efficiency in the 5–9 keV spectral range was determined to be 6.8% ± 0.3%. These targets were 4.1 mm diameter, 4 mm tall hollow epoxy tubes having a 50 μm thick wall supporting a tube of 3 to 3.5 μm thick stainless steel. The NIF laser deposited ∼460 kJ ofmore » 3ω light into the target in a 140 TW, 3.3 ns square pulse. The absolute x-ray emission of the source was measured by two calibrated Dante x-ray spectrometers. Time resolved images filtered for the Fe K-shell were recorded to follow the heating of the target. Time integrated high-resolution spectra were recorded in the K-shell range.« less

Bright x-ray stainless steel K-shell source development at the National Ignition Facility

DOE PAGES

May, M. J.; Fournier, K. B.; Colvin, J. D.; ...

2015-06-01

High x-ray conversion efficiency (XRCE) K-shell sources are being developed for high energy density experiments for use as backlighters and for the testing of materials exposed to high x-ray fluxes and fluences. Recently, sources with high XRCE in the K-shell x-ray energy range of iron and nickel were investigated at the National Ignition Facility (NIF). The x-ray conversion efficiency in the 5–9 keV spectral range was determined to be 6.8% ± 0.3%. These targets were 4.1 mm diameter, 4 mm tall hollow epoxy tubes having a 50 μm thick wall supporting a tube of 3 to 3.5 μm thick stainlessmore » steel. The NIF laser deposited ~460 kJ of 3ω light into the target in a 140 TW, 3.3 ns square pulse. The absolute x-ray emission of the source was measured by two calibrated Dante x-ray spectrometers. In conclusion, time resolved images filtered for the Fe K-shell were recorded to follow the heating of the target. Time integrated high-resolution spectra were recorded in the K-shell range« less

Bright x-ray stainless steel K-shell source development at the National Ignition Facility

NASA Astrophysics Data System (ADS)

May, M. J.; Fournier, K. B.; Colvin, J. D.; Barrios, M. A.; Dewald, E. L.; Hohenberger, M.; Moody, J.; Patterson, J. R.; Schneider, M.; Widmann, K.; Regan, S. P.

2015-06-01

High x-ray conversion efficiency (XRCE) K-shell sources are being developed for high energy density experiments for use as backlighters and for the testing of materials exposed to high x-ray fluxes and fluences. Recently, sources with high XRCE in the K-shell x-ray energy range of iron and nickel were investigated at the National Ignition Facility (NIF). The x-ray conversion efficiency in the 5-9 keV spectral range was determined to be 6.8% ± 0.3%. These targets were 4.1 mm diameter, 4 mm tall hollow epoxy tubes having a 50 μm thick wall supporting a tube of 3 to 3.5 μm thick stainless steel. The NIF laser deposited ˜460 kJ of 3ω light into the target in a 140 TW, 3.3 ns square pulse. The absolute x-ray emission of the source was measured by two calibrated Dante x-ray spectrometers. Time resolved images filtered for the Fe K-shell were recorded to follow the heating of the target. Time integrated high-resolution spectra were recorded in the K-shell range.

The Chandra Source Catalog

NASA Astrophysics Data System (ADS)

Evans, Ian N.; Primini, F. A.; Glotfelty, K. J.; Anderson, C. S.; Bonaventura, N. R.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Fabbiano, G.; Galle, E. C.; Gibbs, D. G., II; Grier, J. D.; Hain, R. M.; Hall, D. M.; Harbo, P. N.; He, X.; Houck, J. C.; Karovska, M.; Kashyap, V. L.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Mossman, A. E.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Refsdal, B. L.; Rots, A. H.; Siemiginowska, A.; Sundheim, B. A.; Tibbetts, M. S.; Van Stone, D. W.; Winkelman, S. L.; Zografou, P.

2010-03-01

The Chandra Source Catalog (CSC) is a general purpose virtual X-ray astrophysics facility that provides access to a carefully selected set of generally useful quantities for individual X-ray sources, and is designed to satisfy the needs of a broad-based group of scientists, including those who may be less familiar with astronomical data analysis in the X-ray regime. The first release of the CSC includes information about 94,676 distinct X-ray sources detected in a subset of public ACIS imaging observations from roughly the first eight years of the Chandra mission. This release of the catalog includes point and compact sources with observed spatial extents < 30". The catalog (1) provides access to estimates of the X-ray source properties for detected sources with good scientific fidelity; (2) facilitates analysis of a wide range of statistical properties for classes of X-ray sources; and (3) provides efficient access to calibrated observational data and ancillary data products for individual X-ray sources. The catalog includes real X-ray sources detected with flux estimates that are at least 3 times their estimated 1σ uncertainties in at least one energy band, while maintaining the number of spurious sources at a level of < 1 false source per field for a 100 ks observation. For each detected source, the CSC provides commonly tabulated quantities, including source position, extent, multi-band fluxes, hardness ratios, and variability statistics. In addition, for each X-ray source the CSC includes an extensive set of file-based data products that can be manipulated interactively, including source images, event lists, light curves, and spectra. Support for development of the CSC is provided by the National Aeronautics and Space Administration through the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics and Space Administration under contract NAS 8-03060.

X-Ray Structure determination of the Glycine Cleavage System Protein H of Mycobacterium tuberculosis Using An Inverse Compton Synchrotron X-Ray Source

PubMed Central

Abendroth, Jan; McCormick, Michael S.; Edwards, Thomas E.; Staker, Bart; Loewen, Roderick; Gifford, Martin; Rifkin, Jeff; Mayer, Chad; Guo, Wenjin; Zhang, Yang; Myler, Peter; Kelley, Angela; Analau, Erwin; Hewitt, Stephen Nakazawa; Napuli, Alberto J.; Kuhn, Peter; Ruth, Ronald D.; Stewart, Lance J.

2010-01-01

Structural genomics discovery projects require ready access to both X-ray and NMR instrumentation which support the collection of experimental data needed to solve large numbers of novel protein structures. The most productive X-ray crystal structure determination laboratories make extensive frequent use of tunable synchrotron X-ray light to solve novel structures by anomalous diffraction methods. This requires that frozen cryo-protected crystals be shipped to large government-run synchrotron facilities for data collection. In an effort to eliminate the need to ship crystals for data collection, we have developed the first laboratory-scale synchrotron light source capable of performing many of the state-of-the-art synchrotron applications in X-ray science. This Compact Light Source is a first-in-class device that uses inverse Compton scattering to generate X-rays of sufficient flux, tunable wavelength and beam size to allow high-resolution X-ray diffraction data collection from protein crystals. We report on benchmarking tests of X-ray diffraction data collection with hen egg white lysozyme, and the successful high-resolution X-ray structure determination of the Glycine cleavage system protein H from Mycobacterium tuberculosis using diffraction data collected with the Compact Light Source X-ray beam. PMID:20364333

Diagnostics of underwater electrical wire explosion through a time- and space-resolved hard x-ray source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheftman, D.; Shafer, D.; Efimov, S.

2012-10-15

A time- and space-resolved hard x-ray source was developed as a diagnostic tool for imaging underwater exploding wires. A {approx}4 ns width pulse of hard x-rays with energies of up to 100 keV was obtained from the discharge in a vacuum diode consisting of point-shaped tungsten electrodes. To improve contrast and image quality, an external pulsed magnetic field produced by Helmholtz coils was used. High resolution x-ray images of an underwater exploding wire were obtained using a sensitive x-ray CCD detector, and were compared to optical fast framing images. Future developments and application of this diagnostic technique are discussed.

Diagnostics of underwater electrical wire explosion through a time- and space-resolved hard x-ray source.

PubMed

Sheftman, D; Shafer, D; Efimov, S; Gruzinsky, K; Gleizer, S; Krasik, Ya E

2012-10-01

A time- and space-resolved hard x-ray source was developed as a diagnostic tool for imaging underwater exploding wires. A ~4 ns width pulse of hard x-rays with energies of up to 100 keV was obtained from the discharge in a vacuum diode consisting of point-shaped tungsten electrodes. To improve contrast and image quality, an external pulsed magnetic field produced by Helmholtz coils was used. High resolution x-ray images of an underwater exploding wire were obtained using a sensitive x-ray CCD detector, and were compared to optical fast framing images. Future developments and application of this diagnostic technique are discussed.

Miniaturized, High-Speed, Modulated X-Ray Source

NASA Technical Reports Server (NTRS)

Gendreau, Keith; Arzoumanian, Zaven; Kenyon, Steve; Spartana, Nick

2013-01-01

A low-cost, miniature x-ray source has been developed that can be modulated in intensity from completely off to full intensity on nanosecond timescales. This modulated x-ray source (MXS) has no filaments and is extremely rugged. The energy level of the MXS is adjustable from 0 to more than 100 keV. It can be used as the core of many new devices, providing the first practical, arbitrarily time-variable source of x-rays. The high-speed switching capability and miniature size make possible many new technologies including x-ray-based communication, compact time-resolved x-ray diffraction, novel x-ray fluorescence instruments, and low- and precise-dose medical x-rays. To make x-rays, the usual method is to accelerate electrons into a target material held at a high potential. When the electrons stop in the target, x-rays are produced with a spectrum that is a function of the target material and the energy to which the electrons are accelerated. Most commonly, the electrons come from a hot filament. In the MXS, the electrons start off as optically driven photoelectrons. The modulation of the x-rays is then tied to the modulation of the light that drives the photoelectron source. Much of the recent development has consisted of creating a photoelectrically-driven electron source that is robust, low in cost, and offers high intensity. For robustness, metal photocathodes were adopted, including aluminum and magnesium. Ultraviolet light from 255- to 350-nm LEDs (light emitting diodes) stimulated the photoemissions from these photocathodes with an efficiency that is maximized at the low-wavelength end (255 nm) to a value of roughly 10(exp -4). The MXS units now have much higher brightness, are much smaller, and are made using a number of commercially available components, making them extremely inexpensive. In the latest MXS design, UV efficiency is addressed by using a high-gain electron multiplier. The photocathode is vapor-deposited onto the input cone of a Burle Magnum(TradeMark) multiplier. This system yields an extremely robust photon-driven electron source that can tolerate long, weeks or more, exposure to air with negligible degradation. The package is also small. When combined with the electron target, necessary vacuum fittings, and supporting components (but not including LED electronics or high-voltage sources), the entire modulated x-ray source weighs as little as 158 grams.

Table-top laser-driven ultrashort electron and X-ray source: the CIBER-X source project

NASA Astrophysics Data System (ADS)

Girardeau-Montaut, Jean-Pierre; Kiraly, Bélà; Girardeau-Montaut, Claire; Leboutet, Hubert

2000-09-01

We report on the development of a new laser-driven table-top ultrashort electron and X-ray source, also called the CIBER-X source . X-ray pulses are produced by a three-step process which consists of the photoelectron emission from a thin metallic photocathode illuminated by 16 ps duration laser pulses at 213 nm. The e-gun is a standard Pierce diode electrode type, in which electrons are accelerated by a cw electric field of ˜11 MV/m up to a hole made in the anode. The photoinjector produces a train of 70-80 keV electron pulses of ˜0.5 nC and 20 A peak current at a repetition rate of 10 Hz. The electrons are then transported outside the diode along a path of 20 cm length, and are focused onto a target of thullium by magnetic fields produced by two electromagnetic coils. X-rays are then produced by the impact of electrons on the target. Simulations of geometrical, electromagnetic fields and energetic characteristics of the complete source were performed previously with the assistance of the code PIXEL1 also developed at the laboratory. Finally, experimental electron and X-ray performances of the CIBER-X source as well as its application to very low dose imagery are presented and discussed. source Compacte d' Impulsions Brèves d' Electrons et de Rayons X

The Linac Coherent Light Source: Recent Developments and Future Plans

DOE PAGES

Schoenlein, R. W.; Boutet, S.; Minitti, M. P.; ...

2017-08-18

The development of X-ray free-electron lasers (XFELs) has launched a new era in X-ray science by providing ultrafast coherent X-ray pulses with a peak brightness that is approximately one billion times higher than previous X-ray sources. The Linac Coherent Light Source (LCLS) facility at the SLAC National Accelerator Laboratory, the world’s first hard X-ray FEL, has already demonstrated a tremendous scientific impact across broad areas of science. Here in this paper, a few of the more recent representative highlights from LCLS are presented in the areas of atomic, molecular, and optical science; chemistry; condensed matter physics; matter in extreme conditions;more » and biology. This paper also outlines the near term upgrade (LCLS-II) and motivating science opportunities for ultrafast X-rays in the 0.25–5 keV range at repetition rates up to 1 MHz. Future plans to extend the X-ray energy reach to beyond 13 keV (<1 Å) at high repetition rate (LCLS-II-HE) are envisioned, motivated by compelling new science of structural dynamics at the atomic scale.« less

Compact x-ray source and panel

DOEpatents

Sampayon, Stephen E [Manteca, CA

2008-02-12

A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

Technological Challenges to X-Ray FELs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nuhn, Heinz-Dieter

1999-09-16

There is strong interest in the development of x-ray free electron lasers (x-ray FELs). The interest is driven by the scientific opportunities provided by intense, coherent x-rays. An x-ray FEL has all the characteristics of a fourth-generation source: brightness several orders of magnitude greater than presently achieved in third-generation sources, full transverse coherence, and sub-picosecond long pulses. The SLAC and DESY laboratories have presented detailed design studies for X-Ray FEL user facilities around the 0.1 nm wavelength-regime (LCLS at SLAC, TESLA X-Ray FEL at DESY). Both laboratories are engaged in proof-of-principle experiments are longer wavelengths (TTF FEL Phase I atmore » 71 nm, VISA at 600-800 nm) with results expected in 1999. The technologies needed to achieve the proposed performances are those of bright electron sources, of acceleration systems capable of preserving the brightness of the source, and of undulators capable of meeting the magnetic and mechanical tolerances that are required for operation in the SASE mode. This paper discusses the technological challenges presented by the X-Ray FEL projects.« less

Laser-driven powerful kHz hard x-ray source

NASA Astrophysics Data System (ADS)

Li, Minghua; Huang, Kai; Chen, Liming; Yan, Wenchao; Tao, Mengze; Zhao, Jiarui; Ma, Yong; Li, Yifei; Zhang, Jie

2017-08-01

A powerful hard x-ray source based on laser plasma interaction is developed. By introducing the kHz, 800 nm pulses onto a rotating molybdenum (Mo) disk target, intense Mo Kα x-rays are emitted with suppressed bremsstrahlung background. Results obtained with different laser intensities suggest that the dominant absorption mechanism responsible for the high conversion efficiency is vacuum heating (VH). The high degree of spatial coherence is verified. With the high average flux and a source size comparable to the laser focus spot, absorption contrast imaging and phase contrast imaging are carried out to test the imaging capability of the source. Not only useful for imaging application, this compact x-ray source is also holding great potential for ultrafast x-ray diffraction (XRD) due to the intrinsic merits such as femtosecond pulse duration and natural synchronization with the driving laser pulses.

X-ray source development for EXAFS measurements on the National Ignition Facility

DOE PAGES

Coppari, F.; Thorn, D. B.; Kemp, G. E.; ...

2017-08-28

We present that extended X-ray absorption Fine Structure (EXAFS) measurements require a bright, spectrally smooth, and broad-band x-ray source. In a laser facility, such an x-ray source can be generated by a laser-driven capsule implosion. In order to optimize the x-ray emission, different capsule types and laser irradiations have been tested at the National Ignition Facility (NIF). A crystal spectrometer is used to disperse the x-rays and high efficiency image plate detectors are used to measure the absorption spectra in transmission geometry. Finally, EXAFS measurements at the K-edge of iron at ambient conditions have been obtained for the first timemore » on the NIF laser, and the requirements for optimization have been established.« less

SU-F-E-01: Pitfalls: Reliability and Performance of Diagnostic X-Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behling, R

2016-06-15

Purpose: Performance and reliability of medical X-ray tubes for imaging are crucial from an ethical, clinical and economic perspective. This lecture will deliver insight into the aspects to consider during the decision making process to invest in X-ray imaging equipment. Outdated metric still hampers realistic product comparison. It is time to change this and to comply with latest standards, which consider current technology. Failure modes and ways to avoid down-time of the equipment shall be discussed. In view of the increasing number of interventional procedures and the hazards associated with ionizing radiation, toxic contrast agents, and the combination thereof, themore » aspect of system reliability is of paramount importance. Methods: A comprehensive picture of trends for different modalities (CT, angiography, general radiology) has been drawn and led to the development of novel X-ray tube technology. Results: Recent X-ray tubes feature enhanced reliability and unprecedented performance. Relevant metrics for product comparison still have to be implemented in practice. Conclusion: The speed of scientific and industrial development of new diagnostic and therapeutic X-ray sources remains tremendous. Still, users suffer from gaps between desire and reality in day-to-day diagnostic routine. X-ray sources are still limiting cutting-edge medical procedures. Side-effects of wear and tear, limitations of the clinical work flow, costs, the characteristics of the X-ray spectrum and others topics need to be further addressed. New applications and modalities, like detection-based color-resolved X-ray and phase-contrast / dark-field imaging will impact the course of new developments of X-ray sources. The author is employee of Royal Philips.« less

Flash x-ray radiography of argon jets in ambient air

NASA Astrophysics Data System (ADS)

Geiswiller, J.; Robert, E.; Huré, L.; Cachoncinlle, C.; Viladrosa, R.; Pouvesle, J. M.

1998-09-01

This paper describes the development and application of a soft x-ray flash radiography technique. A very compact soft x-ray flash source has been specially designed for these studies. The table-top x-ray source developed in this work emits strong doses, up to one roentgen at the output window, of x-ray photons, with most of them in the characteristic lines of the anode material (photon energy in the energy range 5-10 keV), in pulse of 20 ns FWHM with an x-ray emission zone smaller than 0957-0233/9/9/024/img1. All these characteristics make this source attractive for the x-ray radiography of high-speed phenomena, down to ten nanoseconds duration and/or for the media presenting weak absorption for the harder x-ray photons emitted by more conventional flash x-ray systems. Argon streams in ambient air were chosen as a typical case to enlighten the potentialities of this method. Single-shot radiographs of such an argon jet through rectangular nozzles were obtained. No attempt of quantitative measurement of local density in the argon stream has yet been performed, only the qualitative structure of the jet has been investigated. Nevertheless, these preliminary results enable us to state that the diagnostics of gaseous or plasma media, even at rather low pressures, can proceed using soft x-ray flash radiography.

First refraction contrast imaging via Laser-Compton Scattering X-ray at KEK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakaue, Kazuyuki; Aoki, Tatsuro; Washio, Masakazu

2012-07-31

Laser-Compton Scattering (LCS) is one of the most feasible techniques for high quality, high brightness, and compact X-ray source. High energy electron beam produced by accelerators scatters off the laser photon at a small spot. As a laser target, we have been developing a pulsedlaser storage cavity for increasing an X-ray flux. The X-ray flux was still inadequate that was 2.1 Multiplication-Sign 10{sup 5}/sec, however, we performed first refraction contrast imaging in order to evaluate the quality of LCS X-ray. Edge enhanced contrast imaging was achieved by changing the distance from sample to detector. The edge enhancement indicates that themore » LCS X-ray has small source size, i.e. high brightness. We believe that the result has demonstrated good feasibility of linac-based high brightness X-ray sources via laser-electron Compton scatterings.« less

Development of an X-Ray Catheter Final Report CRADA No. TC-1265-96

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trebes, J.; Schlossberg, M.

2017-11-01

Toe goal of this CRADA project was to develop a catheter-based x-ray source to provide treatment of restenosis in arteries with a radiation source which can be precisely controlled and turned on and off at will.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mills, Dennis; Padmore, Howard; Lessner, Eliane

Each new generation of synchrotron radiation sources has delivered an increase in average brightness 2 to 3 orders of magnitude over the previous generation. The next evolution toward diffraction-limited storage rings will deliver another 3 orders of magnitude increase. For ultrafast experiments, free electron lasers (FELs) deliver 10 orders of magnitude higher peak brightness than storage rings. Our ability to utilize these ultrabright sources, however, is limited by our ability to focus, monochromate, and manipulate these beams with X-ray optics. X-ray optics technology unfortunately lags behind source technology and limits our ability to maximally utilize even today’s X-ray sources. Withmore » ever more powerful X-ray sources on the horizon, a new generation of X-ray optics must be developed that will allow us to fully utilize these beams of unprecedented brightness. The increasing brightness of X-ray sources will enable a new generation of measurements that could have revolutionary impact across a broad area of science, if optical systems necessary for transporting and analyzing X-rays can be perfected. The high coherent flux will facilitate new science utilizing techniques in imaging, dynamics, and ultrahigh-resolution spectroscopy. For example, zone-plate-based hard X-ray microscopes are presently used to look deeply into materials, but today’s resolution and contrast are restricted by limitations of the current lithography used to manufacture nanodiffractive optics. The large penetration length, combined in principle with very high spatial resolution, is an ideal probe of hierarchically ordered mesoscale materials, if zone-plate focusing systems can be improved. Resonant inelastic X-ray scattering (RIXS) probes a wide range of excitations in materials, from charge-transfer processes to the very soft excitations that cause the collective phenomena in correlated electronic systems. However, although RIXS can probe high-energy excitations, the most exciting and potentially revolutionary science involves soft excitations such as magnons and phonons; in general, these are well below the resolution that can be probed by today’s optical systems. The study of these low-energy excitations will only move forward if advances are made in high-resolution gratings for the soft X-ray energy region, and higher-resolution crystal analyzers for the hard X-ray region. In almost all the forefront areas of X-ray science today, the main limitation is our ability to focus, monochromate, and manipulate X-rays at the level required for these advanced measurements. To address these issues, the U.S. Department of Energy (DOE) Office of Basic Energy Sciences (BES) sponsored a workshop, X-ray Optics for BES Light Source Facilities, which was held March 27–29, 2013, near Washington, D.C. The workshop addressed a wide range of technical and organizational issues. Eleven working groups were formed in advance of the meeting and sought over several months to define the most pressing problems and emerging opportunities and to propose the best routes forward for a focused R&D program to solve these problems. The workshop participants identified eight principal research directions (PRDs), as follows: Development of advanced grating lithography and manufacturing for high-energy resolution techniques such as soft X-ray inelastic scattering. Development of higher-precision mirrors for brightness preservation through the use of advanced metrology in manufacturing, improvements in manufacturing techniques, and in mechanical mounting and cooling. Development of higher-accuracy optical metrology that can be used in manufacturing, verification, and testing of optomechanical systems, as well as at wavelength metrology that can be used for quantification of individual optics and alignment and testing of beamlines. Development of an integrated optical modeling and design framework that is designed and maintained specifically for X-ray optics. Development of nanolithographic techniques for improved spatial resolution and efficiency of zone plates. Development of large, perfect single crystals of materials other than silicon for use as beam splitters, seeding monochromators, and high-resolution analyzers. Development of improved thin-film deposition methods for fabrication of multilayer Laue lenses and high-spectral-resolution multilayer gratings. Development of supports, actuator technologies, algorithms, and controls to provide fully integrated and robust adaptive X-ray optic systems. Development of fabrication processes for refractive lenses in materials other than silicon. The workshop participants also addressed two important nontechnical areas: our relationship with industry and organization of optics within the light source facilities. Optimization of activities within these two areas could have an important effect on the effectiveness and efficiency of our overall endeavor. These are crosscutting managerial issues that we identified as areas that needed further in-depth study, but they need to be coordinated above the individual facilities. Finally, an issue that cuts across many of the optics improvements listed above is routine access to beamlines that ideally are fully dedicated to optics research and/or development. The success of the BES X-ray user facilities in serving a rapidly increasing user community has led to a squeezing of beam time for vital instrumentation activities. Dedicated development beamlines could be shared with other R&D activities, such as detector programs and novel instrument development. In summary, to meet the challenges of providing the highest-quality X-ray beams for users and to fully utilize the high-brightness sources of today and those that are on the horizon, it will be critical to make strategic investments in X-ray optics R&D. This report can provide guidance and direction for effective use of investments in the field of X-ray optics and potential approaches to develop a better-coordinated program of X-ray optics development within the suite of BES synchrotron radiation facilities. Due to the importance and complexity of the field, the need for tight coordination between BES light source facilities and with industry, as well as the rapid evolution of light source capabilities, the workshop participants recommend holding similar workshops at least biannually.« less

Plasma instability control toward high fluence, high energy x-ray continuum source

NASA Astrophysics Data System (ADS)

Poole, Patrick; Kirkwood, Robert; Wilks, Scott; Blue, Brent

2017-10-01

X-ray source development at Omega and NIF seeks to produce powerful radiation with high conversion efficiency for material effects studies in extreme fluence environments. While current K-shell emission sources can achieve tens of kJ on NIF up to 22 keV, the conversion efficiency drops rapidly for higher Z K-alpha energies. Pulsed power devices are efficient generators of MeV bremsstrahlung x-rays but are unable to produce lower energy photons in isolation, and so a capability gap exists for high fluence x-rays in the 30 - 100 keV range. A continuum source under development utilizes instabilities like Stimulated Raman Scattering (SRS) to generate plasma waves that accelerate electrons into high-Z converter walls. Optimizing instabilities using existing knowledge on their elimination will allow sufficiently hot and high yield electron distributions to create a superior bremsstrahlung x-ray source. An Omega experiment has been performed to investigate the optimization of SRS and high energy x-rays using Au hohlraums with parylene inner lining and foam fills, producing 10× greater x-ray yield at 50 keV than conventional direct drive experiments on the facility. Experiment and simulation details on this campaign will be presented. This work was performed under the auspices of the US DoE by LLNL under Contract No. DE-AC52-07NA27344.

Analysis of monochromatic and quasi-monochromatic X-ray sources in imaging and therapy

NASA Astrophysics Data System (ADS)

Westphal, Maximillian; Lim, Sara; Nahar, Sultana; Orban, Christopher; Pradhan, Anil

2017-04-01

We studied biomedical imaging and therapeutic applications of recently developed quasi-monochromatic and monochromatic X-ray sources. Using the Monte Carlo code GEANT4, we found that the quasi-monochromatic 65 keV Gaussian X-ray spectrum created by inverse Compton scattering with relatavistic electron beams were capable of producing better image contrast with less radiation compared to conventional 120 kV broadband CT scans. We also explored possible experimental detection of theoretically predicted K α resonance fluorescence in high-Z elements using the European Synchrotron Research Facility with a tungsten (Z = 74) target. In addition, we studied a newly developed quasi-monochromatic source generated by converting broadband X-rays to monochromatic K α and β X-rays with a zirconium target (Z = 40). We will further study how these K α and K β dominated spectra can be implemented in conjunction with nanoparticles for targeted therapy. Acknowledgement: Ohio Supercomputer Center, Columbus, OH.

Ultrafast X-Ray Coherent Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reis, David

2009-05-01

This main purpose of this grant was to develop the nascent eld of ultrafast x-ray science using accelerator-based sources, and originally developed from an idea that a laser could modulate the di racting properties of a x-ray di racting crystal on a fast enough time scale to switch out in time a shorter slice from the already short x-ray pulses from a synchrotron. The research was carried out primarily at the Advanced Photon Source (APS) sector 7 at Argonne National Laboratory and the Sub-Picosecond Pulse Source (SPPS) at SLAC; in anticipation of the Linac Coherent Light Source (LCLS) x-ray freemore » electron laser that became operational in 2009 at SLAC (all National User Facilities operated by BES). The research centered on the generation, control and measurement of atomic-scale dynamics in atomic, molecular optical and condensed matter systems with temporal and spatial resolution . It helped develop the ultrafast physics, techniques and scienti c case for using the unprecedented characteristics of the LCLS. The project has been very successful with results have been disseminated widely and in top journals, have been well cited in the eld, and have laid the foundation for many experiments being performed on the LCLS, the world's rst hard x-ray free electron laser.« less

Advanced X-Ray Sources Ensure Safe Environments

NASA Technical Reports Server (NTRS)

2008-01-01

Ames Research Center awarded inXitu Inc. (formerly Microwave Power Technology), of Mountain View, California, an SBIR contract to develop a new design of electron optics for forming and focusing electron beams that is applicable to a broad class of vacuum electron devices. This technology offers an inherently rugged and more efficient X-ray source for material analysis; a compact and rugged X-ray source for smaller rovers on future Mars missions; and electron beam sources to reduce undesirable emissions from small, widely distributed pollution sources; and remediation of polluted sites.

Development of grating-based x-ray Talbot interferometry at the advanced photon source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marathe, Shashidhara; Xiao Xianghui; Wojcik, Michael J.

2012-07-31

We report on the ongoing effort to develop hard x-ray Talbot interferometry at the Advanced Photon Source (APS), Argonne National Laboratory, USA. We describe the design of the interferometer and preliminary results obtained at 25 keV using a feather and a phantom sample lithographically fabricated of gold. We mention the future developmental goals and applications of this technique as a metrology tool for x-ray optics and beam wavefront characterization.

Gold nanoparticle contrast agents in advanced X-ray imaging technologies.

PubMed

Ahn, Sungsook; Jung, Sung Yong; Lee, Sang Joon

2013-05-17

Recently, there has been significant progress in the field of soft- and hard-X-ray imaging for a wide range of applications, both technically and scientifically, via developments in sources, optics and imaging methodologies. While one community is pursuing extensive applications of available X-ray tools, others are investigating improvements in techniques, including new optics, higher spatial resolutions and brighter compact sources. For increased image quality and more exquisite investigation on characteristic biological phenomena, contrast agents have been employed extensively in imaging technologies. Heavy metal nanoparticles are excellent absorbers of X-rays and can offer excellent improvements in medical diagnosis and X-ray imaging. In this context, the role of gold (Au) is important for advanced X-ray imaging applications. Au has a long-history in a wide range of medical applications and exhibits characteristic interactions with X-rays. Therefore, Au can offer a particular advantage as a tracer and a contrast enhancer in X-ray imaging technologies by sensing the variation in X-ray attenuation in a given sample volume. This review summarizes basic understanding on X-ray imaging from device set-up to technologies. Then this review covers recent studies in the development of X-ray imaging techniques utilizing gold nanoparticles (AuNPs) and their relevant applications, including two- and three-dimensional biological imaging, dynamical processes in a living system, single cell-based imaging and quantitative analysis of circulatory systems and so on. In addition to conventional medical applications, various novel research areas have been developed and are expected to be further developed through AuNP-based X-ray imaging technologies.

New developments in high pressure x-ray spectroscopy beamline at High Pressure Collaborative Access Team

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, Y. M., E-mail: yxiao@carnegiescience.edu; Chow, P.; Boman, G.

The 16 ID-D (Insertion Device - D station) beamline of the High Pressure Collaborative Access Team at the Advanced Photon Source is dedicated to high pressure research using X-ray spectroscopy techniques typically integrated with diamond anvil cells. The beamline provides X-rays of 4.5-37 keV, and current available techniques include X-ray emission spectroscopy, inelastic X-ray scattering, and nuclear resonant scattering. The recent developments include a canted undulator upgrade, 17-element analyzer array for inelastic X-ray scattering, and an emission spectrometer using a polycapillary half-lens. Recent development projects and future prospects are also discussed.

Mechanical design of thin-film diamond crystal mounting apparatus for coherence preservation hard x-ray optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shu, Deming, E-mail: shu@aps.anl.gov; Shvyd’ko, Yuri V.; Stoupin, Stanislav

2016-07-27

A new thin-film diamond crystal mounting apparatus has been designed at the Advanced Photon Source (APS) for coherence preservation hard x-ray optics with optimized thermal contact and minimized crystal strain. This novel mechanical design can be applied to new development in the field of: x-ray optics cavities for hard x-ray free-electron laser oscillators (XFELOs), self-seeding monochromators for hard x-ray free-electron laser (XFEL) with high average thermal loading, high heat load diamond crystal monochromators and beam-sharing/beam-split-and-delay devices for XFEL facilities and future upgraded high-brightness coherent x-ray source in the MBA lattice configuration at the APS.

Debris-free soft x-ray source with gas-puff target

NASA Astrophysics Data System (ADS)

Ni, Qiliang; Chen, Bo; Gong, Yan; Cao, Jianlin; Lin, Jingquan; Lee, Hongyan

2001-12-01

We have been developing a debris-free laser plasma light source with a gas-puff target system whose nozzle is driven by a piezoelectric crystal membrane. The gas-puff target system can utilize gases such as CO2, O2 or some gas mixture according to different experiments. Therefore, in comparison with soft X-ray source using a metal target, after continuously several-hour laser interaction with gas from the gas-puff target system, no evidences show that the light source can produce debris. The debris-free soft X-ray source is prepared for soft X-ray projection lithography research at State Key Laboratory of Applied Optics. Strong emission from CO2, O2 and Kr plasma is observed.

Luminescence properties after X-ray irradiation for dosimetry

NASA Astrophysics Data System (ADS)

Hong, Duk-Geun; Kim, Myung-Jin

2016-05-01

To investigate the luminescence characteristics after exposure to X-ray radiation, we developed an independent, small X-ray irradiation system comprising a Varian VF-50J mini X-ray generator, a Pb collimator, a delay shutter, and an Al absorber. With this system, the apparent dose rate increased linearly to 0.8 Gy/s against the emission current for a 50 kV anode potential when the shutter was delayed for an initial 4 s and the Al absorber was 300 µm thick. In addition, an approximately 20 mm diameter sample area was irradiated homogeneously with X rays. Based on three-dimensional (3D) thermoluminescence (TL) spectra, the small X-ray irradiator was considered comparable to the conventional 90Sr/90Y beta source even though the TL intensity from beta irradiation was higher than that from X-ray irradiation. The single aliquot regenerative (SAR) growth curve for the small X-ray irradiator was identical to that for the beta source. Therefore, we concluded that the characteristics of the small X-ray irradiator and the conventional 90Sr/90Y beta source were similar and that X ray irradiation had the potential for being suitable for use in luminescence dosimetry.

X-ray astronomical spectroscopy

NASA Technical Reports Server (NTRS)

Holt, Stephen S.

1987-01-01

The contributions of the Goddard group to the history of X-ray astronomy are numerous and varied. One role that the group has continued to play involves the pursuit of techniques for the measurement and interpretation of the X-ray spectra of cosmic sources. The latest development is the selection of the X-ray microcalorimeter for the Advanced X-ray Astrophysics Facility (AXAF) study payload. This technology is likely to revolutionize the study of cosmic X-ray spectra.

Multi-keV X-ray area source intensity at SGII laser facility

NASA Astrophysics Data System (ADS)

Wang, Rui-rong; An, Hong-hai; Xie, Zhi-yong; Wang, Wei

2018-05-01

Experiments for investigating the feasibility of multi-keV backlighters for several different metallic foil targets were performed at the Shenguang II (SGII) laser facility in China. Emission spectra in the energy range of 1.65-7.0 keV were measured with an elliptically bent crystal spectrometer, and the X-ray source size was measured with a pinhole camera. The X-ray intensity near 4.75 keV and the X-ray source size for titanium targets at different laser intensity irradiances were studied. By adjusting the total laser energy at a fixed focal spot size, laser intensity in the range of 1.5-5.0 × 1015 W/cm2, was achieved. The results show that the line emission intensity near 4.75 keV and the X-ray source size are dependent on the laser intensity and increase as the laser intensity increases. However, an observed "peak" in the X-ray intensity near 4.75 keV occurs at an irradiance of 4.0 × 1015 W/cm2. For the employed experimental conditions, it was confirmed that the laser intensity could play a significant role in the development of an efficient multi-keV X-ray source. The experimental results for titanium indicate that the production of a large (˜350 μm in diameter) intense backlighter source of multi-keV X-rays is feasible at the SGII facility.

Quantum theory for 1D X-ray free electron laser

DOE PAGES

Anisimov, Petr Mikhaylovich

2017-09-19

Classical 1D X-ray Free Electron Laser (X-ray FEL) theory has stood the test of time by guiding FEL design and development prior to any full-scale analysis. Future X-ray FELs and inverse-Compton sources, where photon recoil approaches an electron energy spread value, push the classical theory to its limits of applicability. After substantial efforts by the community to find what those limits are, there is no universally agreed upon quantum approach to design and development of future X-ray sources. We offer a new approach to formulate the quantum theory for 1D X-ray FELs that has an obvious connection to the classicalmore » theory, which allows for immediate transfer of knowledge between the two regimes. In conclusion, we exploit this connection in order to draw quantum mechanical conclusions about the quantum nature of electrons and generated radiation in terms of FEL variables.« less

Quantum theory for 1D X-ray free electron laser

NASA Astrophysics Data System (ADS)

Anisimov, Petr M.

2018-06-01

Classical 1D X-ray Free Electron Laser (X-ray FEL) theory has stood the test of time by guiding FEL design and development prior to any full-scale analysis. Future X-ray FELs and inverse-Compton sources, where photon recoil approaches an electron energy spread value, push the classical theory to its limits of applicability. After substantial efforts by the community to find what those limits are, there is no universally agreed upon quantum approach to design and development of future X-ray sources. We offer a new approach to formulate the quantum theory for 1D X-ray FELs that has an obvious connection to the classical theory, which allows for immediate transfer of knowledge between the two regimes. We exploit this connection in order to draw quantum mechanical conclusions about the quantum nature of electrons and generated radiation in terms of FEL variables.

Three-dimensional reconstruction of neutron, gamma-ray, and x-ray sources using spherical harmonic decomposition

NASA Astrophysics Data System (ADS)

Volegov, P. L.; Danly, C. R.; Fittinghoff, D.; Geppert-Kleinrath, V.; Grim, G.; Merrill, F. E.; Wilde, C. H.

2017-11-01

Neutron, gamma-ray, and x-ray imaging are important diagnostic tools at the National Ignition Facility (NIF) for measuring the two-dimensional (2D) size and shape of the neutron producing region, for probing the remaining ablator and measuring the extent of the DT plasmas during the stagnation phase of Inertial Confinement Fusion implosions. Due to the difficulty and expense of building these imagers, at most only a few two-dimensional projections images will be available to reconstruct the three-dimensional (3D) sources. In this paper, we present a technique that has been developed for the 3D reconstruction of neutron, gamma-ray, and x-ray sources from a minimal number of 2D projections using spherical harmonics decomposition. We present the detailed algorithms used for this characterization and the results of reconstructed sources from experimental neutron and x-ray data collected at OMEGA and NIF.

X-ray Imaging and preliminary studies of the X-ray self-emission from an innovative plasma-trap based on the Bernstein waves heating mechanism

NASA Astrophysics Data System (ADS)

Caliri, C.; Romano, F. P.; Mascali, D.; Gammino, S.; Musumarra, A.; Castro, G.; Celona, L.; Neri, L.; Altana, C.

2013-10-01

Electron Cyclotron Resonance Ion Sources (ECRIS) are based on ECR heated plasmas emitting high fluxes of X-rays. Here we illustrate a pilot study of the X-ray emission from a compact plasma-trap in which an off-resonance microwave-plasma interaction has been attempted, highlighting a possible Bernstein-Waves based heating mechanism. EBWs-heating is obtained via the inner plasma EM-to-ES wave conversion and enables to reach densities much larger than the cut-off ones. At LNS-INFN, an innovative diagnostic technique based on the design of a Pinhole Camera (PHC) coupled to a CCD device for X-ray Imaging of the plasma (XRI) has been developed, in order to integrate X-ray traditional diagnostics (XRS). The complementary use of electrostatic probes measurements and X-ray diagnostics enabled us to gain knowledge about the high energy electrons density and temperature and about the spatial structure of the source. The combination of the experimental data with appropriate modeling of the plasma-source allowed to estimate the X-ray emission intensity in different energy domains (ranging from EUV up to Hard X-rays). The use of ECRIS as X-ray source for multidisciplinary applications, is now a concrete perspective due to the intense fluxes produced by the new plasma heating mechanism.

New developments in ALFT's soft x-ray point sources

NASA Astrophysics Data System (ADS)

Cintron, Dario F.; Guo, Xiaoming; Xu, Meisheng; Ye, Rubin; Antoshko, Yuriy; Antoshko, Yuriy; Drew, Steve; Philippe, Albert; Panarella, Emilio

2002-07-01

The new development in ALFT soft X-ray point source VSX-400 consists mainly of an improvement of the nozzle design to reduce the source size, as well as the introduction of a novel trigger system, capable of triggering the discharge hundreds of million of times without failure, and a debris removal system. Continuous operation for 8 hours at 20 kHz allows us to achieve 400 mW of useful soft X-ray radiation around 1 nm wavelength. In another regime of operation with a high energy machine, the VSX-Z, we have been able to achieve consistently 10 J of X-rays per pulse at a repetition rate that can reach 1 Hz with an input electrical energy of approximately 3 kJ and an efficiency in excess of 10-3.

Report on the 18th International Conference on X-ray and Inner-Shell Processes (X99).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gemmell, D. S.; Physics

2000-01-01

The 18th conference of the series served as a forum for discussing fundamental issues in the field of x-ray and inner-shell processes and their application in various disciplines of science and technology. Special emphasis was given to the opportunities offered by modern synchrotron x-ray sources. The program included plenary talks, progress reports and poster presentations relating to new developments in the field of x-ray and inner-shell processes. The range of topics included: X-ray interactions with atoms, molecules, clusters, surfaces and solids; Decay processes for inner-shell vacancies; X-ray absorption and emission spectroscopy - Photoionization processes; Phenomena associated with highly charged ionsmore » and collisions with energetic particles; Electron-spin and -momentum spectroscopy; X-ray scattering and spectroscopy in the study of magnetic systems; Applications in materials science, biology, geosciences, and other disciplines; Elastic and inelastic x-ray scattering processes in atoms and molecules; Threshold phenomena (post-collision interaction, resonant Raman processes, etc.); Nuclear absorption and scattering of x-rays; 'Fourth-generation' x-ray sources; Processes exploiting the polarization and coherence properties of x-ray beams; Developments in experimental techniques (x-ray optics, temporal techniques, detectors); Microscopy, spectromicroscopy, and various imaging techniques; Non-linear processes and x-ray lasers; Ionization and excitation induced by charged particles and by x-rays; and Exotic atoms (including 'hollow' atoms and atoms that contain 'exotic' particles).« less

X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility.

PubMed

Fournier, K B; Brown, C G; Yeoman, M F; Fisher, J H; Seiler, S W; Hinshelwood, D; Compton, S; Holdener, F R; Kemp, G E; Newlander, C D; Gilliam, R P; Froula, N; Lilly, M; Davis, J F; Lerch, Maj A; Blue, B E

2016-11-01

Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the National Ignition Facility's diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built-in calorimeters give in situ measurements of the x-ray environment along the sample lines of sight. The measured accuracy of sample responses as well as planned modifications to the XTRRA cassette is discussed.

High-resolution μCT of a mouse embryo using a compact laser-driven X-ray betatron source.

PubMed

Cole, Jason M; Symes, Daniel R; Lopes, Nelson C; Wood, Jonathan C; Poder, Kristjan; Alatabi, Saleh; Botchway, Stanley W; Foster, Peta S; Gratton, Sarah; Johnson, Sara; Kamperidis, Christos; Kononenko, Olena; De Lazzari, Michael; Palmer, Charlotte A J; Rusby, Dean; Sanderson, Jeremy; Sandholzer, Michael; Sarri, Gianluca; Szoke-Kovacs, Zsombor; Teboul, Lydia; Thompson, James M; Warwick, Jonathan R; Westerberg, Henrik; Hill, Mark A; Norris, Dominic P; Mangles, Stuart P D; Najmudin, Zulfikar

2018-06-19

In the field of X-ray microcomputed tomography (μCT) there is a growing need to reduce acquisition times at high spatial resolution (approximate micrometers) to facilitate in vivo and high-throughput operations. The state of the art represented by synchrotron light sources is not practical for certain applications, and therefore the development of high-brightness laboratory-scale sources is crucial. We present here imaging of a fixed embryonic mouse sample using a compact laser-plasma-based X-ray light source and compare the results to images obtained using a commercial X-ray μCT scanner. The radiation is generated by the betatron motion of electrons inside a dilute and transient plasma, which circumvents the flux limitations imposed by the solid or liquid anodes used in conventional electron-impact X-ray tubes. This X-ray source is pulsed (duration <30 fs), bright (>10 10 photons per pulse), small (diameter <1 μm), and has a critical energy >15 keV. Stable X-ray performance enabled tomographic imaging of equivalent quality to that of the μCT scanner, an important confirmation of the suitability of the laser-driven source for applications. The X-ray flux achievable with this approach scales with the laser repetition rate without compromising the source size, which will allow the recording of high-resolution μCT scans in minutes. Copyright © 2018 the Author(s). Published by PNAS.

Development of high intensity X-ray sources at the National Ignition Facility

NASA Astrophysics Data System (ADS)

May, M. J.; Colvin, J. D.; Kemp, G. E.; Barrios, M. A.; Widmann, K.; Benjamin, R.; Thorn, D.; Poole, P.; Blue, B.

2018-05-01

Laser heated plasmas have provided recently some of the most powerful and energetic nanosecond length laboratory sources of x-ray photons (Ephoton = 1-30 keV). The highest x-ray to laser conversion is currently accessible by using underdense (ne ˜ 0.25 nc) plasmas since optimal laser coupling is obtained in millimeter scale targets. The targets can have conversion efficiencies of up to 10%. Several types of targets can be used to produce underdense plasmas: metal lined cylindrical cavities, gas pipes, and most recently nano-wire foams. Both the experimental and simulation details of these high intensity x-ray sources are discussed.

On the large scale structure of X-ray background sources

NASA Technical Reports Server (NTRS)

Bi, H. G.; Meszaros, A.; Meszaros, P.

1991-01-01

The large scale clustering of the sources responsible for the X-ray background is discussed, under the assumption of a discrete origin. The formalism necessary for calculating the X-ray spatial fluctuations in the most general case where the source density contrast in structures varies with redshift is developed. A comparison of this with observational limits is useful for obtaining information concerning various galaxy formation scenarios. The calculations presented show that a varying density contrast has a small impact on the expected X-ray fluctuations. This strengthens and extends previous conclusions concerning the size and comoving density of large scale structures at redshifts 0.5 between 4.0.

Toward Active X-ray Telescopes II

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Aldroft, Thomas L.; Atkins, Carolyn; Button, Timothy W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peter; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.;

Observation and theory of X-ray mirages

PubMed Central

Magnitskiy, Sergey; Nagorskiy, Nikolay; Faenov, Anatoly; Pikuz, Tatiana; Tanaka, Mamoko; Ishino, Masahiko; Nishikino, Masaharu; Fukuda, Yuji; Kando, Masaki; Kawachi, Tetsuya; Kato, Yoshiaki

2013-01-01

The advent of X-ray lasers allowed the realization of compact coherent soft X-ray sources, thus opening the way to a wide range of applications. Here we report the observation of unexpected concentric rings in the far-field beam profile at the output of a two-stage plasma-based X-ray laser, which can be considered as the first manifestation of a mirage phenomenon in X-rays. We have developed a method of solving the Maxwell–Bloch equations for this problem, and find that the experimentally observed phenomenon is due to the emergence of X-ray mirages in the plasma amplifier, appearing as phase-matched coherent virtual point sources. The obtained results bring a new insight into the physical nature of amplification of X-ray radiation in laser-induced plasma amplifiers and open additional opportunities for X-ray plasma diagnostics and extreme ultraviolet lithography. PMID:23733009

Observation and theory of X-ray mirages.

PubMed

Magnitskiy, Sergey; Nagorskiy, Nikolay; Faenov, Anatoly; Pikuz, Tatiana; Tanaka, Mamoko; Ishino, Masahiko; Nishikino, Masaharu; Fukuda, Yuji; Kando, Masaki; Kawachi, Tetsuya; Kato, Yoshiaki

2013-01-01

The advent of X-ray lasers allowed the realization of compact coherent soft X-ray sources, thus opening the way to a wide range of applications. Here we report the observation of unexpected concentric rings in the far-field beam profile at the output of a two-stage plasma-based X-ray laser, which can be considered as the first manifestation of a mirage phenomenon in X-rays. We have developed a method of solving the Maxwell-Bloch equations for this problem, and find that the experimentally observed phenomenon is due to the emergence of X-ray mirages in the plasma amplifier, appearing as phase-matched coherent virtual point sources. The obtained results bring a new insight into the physical nature of amplification of X-ray radiation in laser-induced plasma amplifiers and open additional opportunities for X-ray plasma diagnostics and extreme ultraviolet lithography.

Optical and X-ray studies of Compact X-ray Binaries in NGC 5904

NASA Astrophysics Data System (ADS)

Bhalotia, Vanshree; Beck-Winchatz, Bernhard

2018-06-01

Due to their high stellar densities, globular cluster systems trigger various dynamical interactions, such as the formation of compact X-ray binaries. Stellar collisional frequencies have been correlated to the number of X-ray sources detected in various clusters and we hope to measure this correlation for NGC 5904. Optical fluxes of sources from archival HST images of NGC 5904 have been measured using a DOLPHOT PSF photometry in the UV, optical and near-infrared. We developed a data analysis pipeline to process the fluxes of tens of thousands of objects using awk, python and DOLPHOT. We plot color magnitude diagrams in different photometric bands in order to identify outliers that could be X-ray binaries, since they do not evolve the same way as singular stars. Aligning previously measured astrometric data for X-ray sources in NGC 5904 from Chandra with archival astrometric data from HST will filter out the outlier objects that are not X-ray producing, and provide a sample of compact binary systems that are responsible for X-ray emission in NGC 5904. Furthermore, previously measured X-ray fluxes of NGC 5904 from Chandra have also been used to measure the X-ray to optical flux ratio and identify the types of compact X-ray binaries responsible for the X-ray emissions in NGC 5904. We gratefully acknowledge the support from the Illinois Space Grant Consortium.

A final report to the Laboratory Directed Research and Development committee on Project 93-ERP-075: ``X-ray laser propagation and coherence: Diagnosing fast-evolving, high-density laser plasmas using X-ray lasers``

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wan, A.S.; Cauble, R.; Da Silva, L.B.

1996-02-01

This report summarizes the major accomplishments of this three-year Laboratory Directed Research and Development (LDRD) Exploratory Research Project (ERP) entitled ``X-ray Laser Propagation and Coherence: Diagnosing Fast-evolving, High-density Laser Plasmas Using X-ray Lasers,`` tracking code 93-ERP-075. The most significant accomplishment of this project is the demonstration of a new laser plasma diagnostic: a soft x-ray Mach-Zehnder interferometer using a neonlike yttrium x-ray laser at 155 {angstrom} as the probe source. Detailed comparisons of absolute two-dimensional electron density profiles obtained from soft x-ray laser interferograms and profiles obtained from radiation hydrodynamics codes, such as LASNEX, will allow us to validate andmore » benchmark complex numerical models used to study the physics of laser-plasma interactions. Thus the development of soft x-ray interferometry technique provides a mechanism to probe the deficiencies of the numerical models and is an important tool for, the high-energy density physics and science-based stockpile stewardship programs. The authors have used the soft x-ray interferometer to study a number of high-density, fast evolving, laser-produced plasmas, such as the dynamics of exploding foils and colliding plasmas. They are pursuing the application of the soft x-ray interferometer to study ICF-relevant plasmas, such as capsules and hohlraums, on the Nova 10-beam facility. They have also studied the development of enhanced-coherence, shorter-pulse-duration, and high-brightness x-ray lasers. The utilization of improved x-ray laser sources can ultimately enable them to obtain three-dimensional holographic images of laser-produced plasmas.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, L. X.; Zhang, X.; Lockard, J. V.

Transient molecular structures along chemical reaction pathways are important for predicting molecular reactivity, understanding reaction mechanisms, as well as controlling reaction pathways. During the past decade, X-ray transient absorption spectroscopy (XTA, or LITR-XAS, laser-initiated X-ray absorption spectroscopy), analogous to the commonly used optical transient absorption spectroscopy, has been developed. XTA uses a laser pulse to trigger a fundamental chemical process, and an X-ray pulse(s) to probe transient structures as a function of the time delay between the pump and probe pulses. Using X-ray pulses with high photon flux from synchrotron sources, transient electronic and molecular structures of metal complexes havemore » been studied in disordered media from homogeneous solutions to heterogeneous solution-solid interfaces. Several examples from the studies at the Advanced Photon Source in Argonne National Laboratory are summarized, including excited-state metalloporphyrins, metal-to-ligand charge transfer (MLCT) states of transition metal complexes, and charge transfer states of metal complexes at the interface with semiconductor nanoparticles. Recent developments of the method are briefly described followed by a future prospective of XTA. It is envisioned that concurrent developments in X-ray free-electron lasers and synchrotron X-ray facilities as well as other table-top laser-driven femtosecond X-ray sources will make many breakthroughs and realise dreams of visualizing molecular movies and snapshots, which ultimately enable chemical reaction pathways to be controlled.« less

X-ray grating interferometer for materials-science imaging at a low-coherent wiggler source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herzen, Julia; Physics Department and Institute for Medical Engineering, Technische Universitaet Muenchen, 85748 Garching; Donath, Tilman

2011-11-15

X-ray phase-contrast radiography and tomography enable to increase contrast for weakly absorbing materials. Recently, x-ray grating interferometers were developed that extend the possibility of phase-contrast imaging from highly brilliant radiation sources like third-generation synchrotron sources to non-coherent conventional x-ray tube sources. Here, we present the first installation of a three grating x-ray interferometer at a low-coherence wiggler source at the beamline W2 (HARWI II) operated by the Helmholtz-Zentrum Geesthacht at the second-generation synchrotron storage ring DORIS (DESY, Hamburg, Germany). Using this type of the wiggler insertion device with a millimeter-sized source allows monochromatic phase-contrast imaging of centimeter sized objects withmore » high photon flux. Thus, biological and materials-science imaging applications can highly profit from this imaging modality. The specially designed grating interferometer currently works in the photon energy range from 22 to 30 keV, and the range will be increased by using adapted x-ray optical gratings. Our results of an energy-dependent visibility measurement in comparison to corresponding simulations demonstrate the performance of the new setup.« less

A search for X-ray polarization in cosmic X-ray sources. [binary X-ray sources and supernovae remnants

NASA Technical Reports Server (NTRS)

Hughes, J. P.; Long, K. S.; Novick, R.

1983-01-01

Fifteen strong X-ray sources were observed by the X-ray polarimeters on board the OSO-8 satellite from 1975 to 1978. The final results of this search for X-ray polarization in cosmic sources are presented in the form of upper limits for the ten sources which are discussed elsewhere. These limits in all cases are consistent with a thermal origin for the X-ray emission.

Spectroscopic analysis of solar and cosmic X-ray spectra. 1: The nature of cosmic X-ray spectra and proposed analytical techniques

NASA Technical Reports Server (NTRS)

Walker, A. B. C., Jr.

1975-01-01

Techniques for the study of the solar corona are reviewed as an introduction to a discussion of modifications required for the study of cosmic sources. Spectroscopic analysis of individual sources and the interstellar medium is considered. The latter was studied via analysis of its effect on the spectra of selected individual sources. The effects of various characteristics of the ISM, including the presence of grains, molecules, and ionization, are first discussed, and the development of ISM models is described. The expected spectral structure of individual cosmic sources is then reviewed with emphasis on supernovae remnants and binary X-ray sources. The observational and analytical requirements imposed by the characteristics of these sources are identified, and prospects for the analysis of abundances and the study of physical parameters within them are assessed. Prospects for the spectroscopic study of other classes of X-ray sources are also discussed.

Diagnostic X-ray sources-present and future

NASA Astrophysics Data System (ADS)

Behling, Rolf; Grüner, Florian

2018-01-01

This paper compares very different physical principles of X-ray production to spur ideation. Since more than 120 years, bremsstrahlung from X-ray tubes has been the workhorse of medical diagnostics. Generated by X-ray segments comprised of X-ray tubes and high-voltage generators in the various medical systems, X-ray photons in the spectral range between about 16 keV and 150 keV deliver information about anatomy and function of human patients and in pre-clinical animal studies. Despite of strides to employ the wave nature of X-rays as phase sensitive means, commercial diagnostic X-ray systems available until the time of writing still rely exclusively on measuring the attenuation and scattering of X-rays by matter. Significant activities in research aim at building highly brilliant short pulse X-ray sources, based on e.g. synchrotron radiation, free electron lasers and/or laser wake-field acceleration of electrons followed by wiggling with magnetic structures or Thomson scattering in bunches of light. While both approaches, non-brilliant and brilliant sources, have different scope of application, we speculate that a combination may expand the efficacy in medical application. At this point, however, severe technical and commercial difficulties hinder closing this gap. This article may inspire further development and spark innovation in this important field.

Development of a High Dynamic Range Pixel Array Detector for Synchrotrons and XFELs

NASA Astrophysics Data System (ADS)

Weiss, Joel Todd

Advances in synchrotron radiation light source technology have opened new lines of inquiry in material science, biology, and everything in between. However, x-ray detector capabilities must advance in concert with light source technology to fully realize experimental possibilities. X-ray free electron lasers (XFELs) place particularly large demands on the capabilities of detectors, and developments towards diffraction-limited storage ring sources also necessitate detectors capable of measuring very high flux [1-3]. The detector described herein builds on the Mixed Mode Pixel Array Detector (MM-PAD) framework, developed previously by our group to perform high dynamic range imaging, and the Adaptive Gain Integrating Pixel Detector (AGIPD) developed for the European XFEL by a collaboration between Deustsches Elektronen-Synchrotron (DESY), the Paul-Scherrer-Institute (PSI), the University of Hamburg, and the University of Bonn, led by Heinz Graafsma [4, 5]. The feasibility of combining adaptive gain with charge removal techniques to increase dynamic range in XFEL experiments is assessed by simulating XFEL scatter with a pulsed infrared laser. The strategy is incorporated into pixel prototypes which are evaluated with direct current injection to simulate very high incident x-ray flux. A fully functional 16x16 pixel hybrid integrating x-ray detector featuring several different pixel architectures based on the prototypes was developed. This dissertation describes its operation and characterization. To extend dynamic range, charge is removed from the integration node of the front-end amplifier without interrupting integration. The number of times this process occurs is recorded by a digital counter in the pixel. The parameter limiting full well is thereby shifted from the size of an integration capacitor to the depth of a digital counter. The result is similar to that achieved by counting pixel array detectors, but the integrators presented here are designed to tolerate a sustained flux >1011 x-rays/pixel/second. In addition, digitization of residual analog signals allows sensitivity for single x-rays or low flux signals. Pixel high flux linearity is evaluated by direct exposure to an unattenuated synchrotron source x-ray beam and flux measurements of more than 1010 9.52 keV x-rays/pixel/s are made. Detector sensitivity to small signals is evaluated and dominant sources of error are identified. These new pixels boast multiple orders of magnitude improvement in maximum sustained flux over the MM-PAD, which is capable of measuring a sustained flux in excess of 108 x-rays/pixel/second while maintaining sensitivity to smaller signals, down to single x-rays.

Improving the Multi-Wavelength Capability of Chandra Large Programs

NASA Astrophysics Data System (ADS)

Pacucci, Fabio

2017-09-01

In order to fully exploit the joint Chandra/JWST/HST ventures to detect faint sources, we urgently need an advanced matching algorithm between optical/NIR and X-ray catalogs/images. This will be of paramount importance in bridging the gap between upcoming optical/NIR facilities (JWST) and later X-ray ones (Athena, Lynx). We propose to develop an advanced and automated tool to improve the identification of Chandra X-ray counterparts detected in deep optical/NIR fields based on T-PHOT, a software widely used in the community. The developed code will include more than 20 years in advancements of X-ray data analysis and will be released to the public. Finally, we will release an updated catalog of X-ray sources in the CANDELS regions: a leap forward in our endeavor of charting the Universe.

X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fournier, K. B., E-mail: fournier2@llnl.gov; Brown, C. G.; Yeoman, M. F.

2016-11-15

Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the National Ignition Facility’s diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built-in calorimeters give in situ measurements of the x-ray environment along the sample lines ofmore » sight. The measured accuracy of sample responses as well as planned modifications to the XTRRA cassette is discussed.« less

X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility

DOE PAGES

Fournier, K. B.; Brown, Jr., C. G.; Yeoman, M. F.; ...

2016-08-10

Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the NIF’s diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built in calorimeters give in situ measurements of the x-ray environment along the sample lines of sight.more » We discuss the measured accuracy of sample responses, as well as planned modifications to the XTRRA cassette.« less

Development of a fluorescent x-ray source for medical imaging

NASA Astrophysics Data System (ADS)

Toyofuku, F.; Tokumori, K.; Nishimura, K.; Saito, T.; Takeda, T.; Itai, Y.; Hyodo, K.; Ando, M.; Endo, M.; Naito, H.; Uyama, C.

1995-02-01

A fluorescent x-ray source for medical imaging, such as K-edge subtraction angiography and monochromatic x-ray CT, has been developed. Using a 6.5 GeV accumulation ring in Tsukuba, fluorescent x rays, which range from about 30 to 70 keV are generated by irradiating several target materials. Measurements have been made of output intensities and energy spectra for different target angles and extraction angles. The intensities of fluorescent x rays at a 30 mA beam current are on the order of 1-3×106 photons/mm2/s at 30 cm from the local spot where the incident beam is collimated to 1 mm2. A phantom which contains three different contrast media (iodine, barium, gadolinium) was used for the K-edge energy subtraction, and element selective CT images were obtained.

Development of a 0.1 μm linewidth fabrication process for x-ray lithography with a laser plasma source

NASA Astrophysics Data System (ADS)

Bobkowski, Romuald; Fedosejevs, Robert; Broughton, James N.

1999-06-01

A process has been developed for the purpose of fabricating 0.1 micron linewidth interdigital electrode patterns based on proximity x-ray lithography using a laser-plasma source. Such patterns are required in the manufacture of surface acoustic wave devices. The x-ray lithography was carried out using emission form a Cu plasma produced by a 15Hz, 248nm KrF excimer laser. A temporally multiplexed 50ps duration seed pulse was used to extract the KrF laser energy producing a train of several 50ps pulses spaced approximately 2ns apart within each output pulse. Each short pulse within the train gave the high focal spot intensity required to achieve high efficiency emission of keV x-rays. The first stage of the overall process involves the fabrication of x-ray mask patterns on 1 micron thick Si3N4 membranes using 3-beam lithography followed by gold electroplating. The second stage involves x-ray exposure of a chemically amplified resist through the mask patterns to produce interdigital electrode patterns with 0.1 micron linewidth. Helium background gas and thin polycarbonate/aluminum filters are employed to prevent debris particles from the laser-plasma source form reaching the exposed sample. A computer control system fires the laser and monitors the x-ray flux from the laser-plasma source to insure the desired x-ray exposure is achieved at the resist. In order to reduce diffusion effects in the chemically amplified resist during the post exposure bake the temperature had to be reduced from that normally used. Good reproduction of 0.1 micron linewidth patterns into the x-ray resist was obtained once the exposure parameters and post exposure bake were optimized. A compact exposure station using flowing helium at atmospheric pressure has also been developed for the process, alleviating the need for a vacuum chamber. The details of the overall process and the compact exposure station will be presented.

Three Bright X-ray Sources in NGC 1313

NASA Astrophysics Data System (ADS)

Colbert, E.; Petre, R.; Schlegel, E.

1992-12-01

Three bright X-ray sources were detected in a recent (April/May 1991) ROSAT PSPC observation of the nearby (D ~ 4.5 Mpc) face--on barred spiral galaxy NGC 1313. Two of the sources were at positions coincident with X-ray sources detected by Fabbiano & Trinchieri (ApJ 315, 1987) in a previous (Jan 1980) Einstein IPC observation. The position of the brightest Einstein source is near the center of NGC 1313, and the second Einstein source is ~ 7' south of the ``nuclear'' source, in the outskirts of the spiral arms. A third bright X-ray source was detected in the ROSAT observation ~ 7' southwest of the ``nuclear'' source. We present X-ray spectra and X-ray images for the three bright sources found in the ROSAT observation of NGC 1313, and compare with previous Einstein results. Spectral analysis of these sources require them to have very large soft X-ray luminosities ( ~ 10(40) erg s(-1) ) when compared with typical X-ray sources in our Galaxy. Feasible explanations for the X-ray emission are presented. The third X-ray source is positively identified with the recently discovered (Ryder et. al., ApJ 1992) peculiar type-II supernova 1978K.

Multisource inverse-geometry CT. Part II. X-ray source design and prototype

PubMed Central

Neculaes, V. Bogdan; Caiafa, Antonio; Cao, Yang; De Man, Bruno; Edic, Peter M.; Frutschy, Kristopher; Gunturi, Satish; Inzinna, Lou; Reynolds, Joseph; Vermilyea, Mark; Wagner, David; Zhang, Xi; Zou, Yun; Pelc, Norbert J.; Lounsberry, Brian

2016-01-01

Purpose: This paper summarizes the development of a high-power distributed x-ray source, or “multisource,” designed for inverse-geometry computed tomography (CT) applications [see B. De Man et al., “Multisource inverse-geometry CT. Part I. System concept and development,” Med. Phys. 43, 4607–4616 (2016)]. The paper presents the evolution of the source architecture, component design (anode, emitter, beam optics, control electronics, high voltage insulator), and experimental validation. Methods: Dispenser cathode emitters were chosen as electron sources. A modular design was adopted, with eight electron emitters (two rows of four emitters) per module, wherein tungsten targets were brazed onto copper anode blocks—one anode block per module. A specialized ceramic connector provided high voltage standoff capability and cooling oil flow to the anode. A matrix topology and low-noise electronic controls provided switching of the emitters. Results: Four modules (32 x-ray sources in two rows of 16) have been successfully integrated into a single vacuum vessel and operated on an inverse-geometry computed tomography system. Dispenser cathodes provided high beam current (>1000 mA) in pulse mode, and the electrostatic lenses focused the current beam to a small optical focal spot size (0.5 × 1.4 mm). Controlled emitter grid voltage allowed the beam current to be varied for each source, providing the ability to modulate beam current across the fan of the x-ray beam, denoted as a virtual bowtie filter. The custom designed controls achieved x-ray source switching in <1 μs. The cathode-grounded source was operated successfully up to 120 kV. Conclusions: A high-power, distributed x-ray source for inverse-geometry CT applications was successfully designed, fabricated, and operated. Future embodiments may increase the number of spots and utilize fast read out detectors to increase the x-ray flux magnitude further, while still staying within the stationary target inherent thermal limitations. PMID:27487878

Multisource inverse-geometry CT. Part II. X-ray source design and prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neculaes, V. Bogdan, E-mail: neculaes@ge.com; Caia

2016-08-15

Purpose: This paper summarizes the development of a high-power distributed x-ray source, or “multisource,” designed for inverse-geometry computed tomography (CT) applications [see B. De Man et al., “Multisource inverse-geometry CT. Part I. System concept and development,” Med. Phys. 43, 4607–4616 (2016)]. The paper presents the evolution of the source architecture, component design (anode, emitter, beam optics, control electronics, high voltage insulator), and experimental validation. Methods: Dispenser cathode emitters were chosen as electron sources. A modular design was adopted, with eight electron emitters (two rows of four emitters) per module, wherein tungsten targets were brazed onto copper anode blocks—one anode blockmore » per module. A specialized ceramic connector provided high voltage standoff capability and cooling oil flow to the anode. A matrix topology and low-noise electronic controls provided switching of the emitters. Results: Four modules (32 x-ray sources in two rows of 16) have been successfully integrated into a single vacuum vessel and operated on an inverse-geometry computed tomography system. Dispenser cathodes provided high beam current (>1000 mA) in pulse mode, and the electrostatic lenses focused the current beam to a small optical focal spot size (0.5 × 1.4 mm). Controlled emitter grid voltage allowed the beam current to be varied for each source, providing the ability to modulate beam current across the fan of the x-ray beam, denoted as a virtual bowtie filter. The custom designed controls achieved x-ray source switching in <1 μs. The cathode-grounded source was operated successfully up to 120 kV. Conclusions: A high-power, distributed x-ray source for inverse-geometry CT applications was successfully designed, fabricated, and operated. Future embodiments may increase the number of spots and utilize fast read out detectors to increase the x-ray flux magnitude further, while still staying within the stationary target inherent thermal limitations.« less

Methods development for diffraction and spectroscopy studies of metalloenzymes at X-ray free-electron lasers

PubMed Central

Kern, Jan; Hattne, Johan; Tran, Rosalie; Alonso-Mori, Roberto; Laksmono, Hartawan; Gul, Sheraz; Sierra, Raymond G.; Rehanek, Jens; Erko, Alexei; Mitzner, Rolf; Wernet, Phillip; Bergmann, Uwe; Sauter, Nicholas K.; Yachandra, Vittal; Yano, Junko

2014-01-01

X-ray free-electron lasers (XFELs) open up new possibilities for X-ray crystallographic and spectroscopic studies of radiation-sensitive biological samples under close to physiological conditions. To facilitate these new X-ray sources, tailored experimental methods and data-processing protocols have to be developed. The highly radiation-sensitive photosystem II (PSII) protein complex is a prime target for XFEL experiments aiming to study the mechanism of light-induced water oxidation taking place at a Mn cluster in this complex. We developed a set of tools for the study of PSII at XFELs, including a new liquid jet based on electrofocusing, an energy dispersive von Hamos X-ray emission spectrometer for the hard X-ray range and a high-throughput soft X-ray spectrometer based on a reflection zone plate. While our immediate focus is on PSII, the methods we describe here are applicable to a wide range of metalloenzymes. These experimental developments were complemented by a new software suite, cctbx.xfel. This software suite allows for near-real-time monitoring of the experimental parameters and detector signals and the detailed analysis of the diffraction and spectroscopy data collected by us at the Linac Coherent Light Source, taking into account the specific characteristics of data measured at an XFEL. PMID:24914169

Development of polycapillary x-ray optics for x-ray spectroscopy

NASA Astrophysics Data System (ADS)

Adams, Bernhard W.; Attenkofer, Klaus; Bond, Justin L.; Craven, Christopher A.; Cremer, Till; O'Mahony, Aileen; Minot, Michael J.; Popecki, Mark A.

2016-09-01

Bundles of hollow glass capillaries can be tapered to produce quasi-focusing x-ray optics. These optics are known as Kumakhov lenses. These optics are interesting for lab-based sources because they can be used to collimate and concentrate x-rays originating from a point, such as a laser focus or an electron-beam focus in a microtube.

Classification of X-ray sources in the direction of M31

NASA Astrophysics Data System (ADS)

Vasilopoulos, G.; Hatzidimitriou, D.; Pietsch, W.

2012-01-01

M31 is our nearest spiral galaxy, at a distance of 780 kpc. Identification of X-ray sources in nearby galaxies is important for interpreting the properties of more distant ones, mainly because we can classify nearby sources using both X-ray and optical data, while more distant ones via X-rays alone. The XMM-Newton Large Project for M31 has produced an abundant sample of about 1900 X-ray sources in the direction of M31. Most of them remain elusive, giving us little signs of their origin. Our goal is to classify these sources using criteria based on properties of already identified ones. In particular we construct candidate lists of high mass X-ray binaries, low mass X-ray binaries, X-ray binaries correlated with globular clusters and AGN based on their X-ray emission and the properties of their optical counterparts, if any. Our main methodology consists of identifying particular loci of X-ray sources on X-ray hardness ratio diagrams and the color magnitude diagrams of their optical counterparts. Finally, we examined the X-ray luminosity function of the X-ray binaries populations.

X-Ray Processing of ChaMPlane Fields: Methods and Initial Results for Selected Anti-Galactic Center Fields

NASA Astrophysics Data System (ADS)

Hong, JaeSub; van den Berg, Maureen; Schlegel, Eric M.; Grindlay, Jonathan E.; Koenig, Xavier; Laycock, Silas; Zhao, Ping

2005-12-01

We describe the X-ray analysis procedure of the ongoing Chandra Multiwavelength Plane (ChaMPlane) Survey and report the initial results from the analysis of 15 selected anti-Galactic center observations (90deg

Advanced Computed-Tomography Inspection System

NASA Technical Reports Server (NTRS)

Harris, Lowell D.; Gupta, Nand K.; Smith, Charles R.; Bernardi, Richard T.; Moore, John F.; Hediger, Lisa

1993-01-01

Advanced Computed Tomography Inspection System (ACTIS) is computed-tomography x-ray apparatus revealing internal structures of objects in wide range of sizes and materials. Three x-ray sources and adjustable scan geometry gives system unprecedented versatility. Gantry contains translation and rotation mechanisms scanning x-ray beam through object inspected. Distance between source and detector towers varied to suit object. System used in such diverse applications as development of new materials, refinement of manufacturing processes, and inspection of components.

On the scaling of multicrystal data sets collected at high-intensity X-ray and electron sources

DOE PAGES

Coppens, Philip; Fournier, Bertrand

2015-11-11

Here, the need for data-scaling has become increasingly evident as time-resolved pump-probe photocrystallography is rapidly developing at high intensity X-ray sources. Several aspects of the scaling of data sets collected at synchrotrons, XFELs (X-ray Free Electron Lasers) and high-intensity pulsed electron sources are discussed. They include laser-ON/laser-OFF data scaling, inter- and intra-data set scaling. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

Picosecond excimer laser-plasma x-ray source for microscopy, biochemistry, and lithography

NASA Astrophysics Data System (ADS)

Turcu, I. C. Edmond; Ross, Ian N.; Trenda, P.; Wharton, C. W.; Meldrum, R. A.; Daido, Hiroyuki; Schulz, M. S.; Fluck, P.; Michette, Alan G.; Juna, A. P.; Maldonado, Juan R.; Shields, Harry; Tallents, Gregory J.; Dwivedi, L.; Krishnan, J.; Stevens, D. L.; Jenner, T.; Batani, Dimitri; Goodson, H.

1994-02-01

At Rutherford Appleton Laboratory we developed a high repetition rate, picosecond, excimer laser system which generates a high temperature and density plasma source emitting approximately 200 mW (78 mW/sr) x ray average power at h(nu) approximately 1.2 KeV or 0.28 KeV < h(nu) < 0.53 KeV (the `water window'). At 3.37 nm wavelength the spectral brightness of the source is approximately 9 X 1011 photons/s/mm2/mrad2/0.1% bandwidth. The x-ray source serves a large user community for applications such as: scanning and holographic microscopy, the study of the biochemistry of DNA damage and repair, microlithography and spectroscopy.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, W J; Anderson, S G; Barty, C P J

2003-05-28

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

X-ray transmission microscope development

NASA Technical Reports Server (NTRS)

Kaukler, William F.; Rosenberger, Franz E.

1995-01-01

We are developing a hard x-ray microscope for direct observation of solidification dynamics in metal alloys and metal matrix composites. The Fein-Focus Inc. x-ray source was delivered in September and found to perform better than expected. Confirmed resolution of better than 2 micrometers was obtained and magnifications up to 800X were measured. Nickel beads of 30 micrometer diameter were easily detected through 6mm of aluminum. X-ray metallography was performed on several specimens showing high resolution and clear definition of 3-dimensional structures. Prototype furnace installed and tested.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anisimov, Petr Mikhaylovich

Classical 1D X-ray Free Electron Laser (X-ray FEL) theory has stood the test of time by guiding FEL design and development prior to any full-scale analysis. Future X-ray FELs and inverse-Compton sources, where photon recoil approaches an electron energy spread value, push the classical theory to its limits of applicability. After substantial efforts by the community to find what those limits are, there is no universally agreed upon quantum approach to design and development of future X-ray sources. We offer a new approach to formulate the quantum theory for 1D X-ray FELs that has an obvious connection to the classicalmore » theory, which allows for immediate transfer of knowledge between the two regimes. In conclusion, we exploit this connection in order to draw quantum mechanical conclusions about the quantum nature of electrons and generated radiation in terms of FEL variables.« less

Spatially resolved single crystal x-ray spectropolarimetry of wire array z-pinch plasmas

NASA Astrophysics Data System (ADS)

Wallace, M. S.; Haque, S.; Neill, P.; Pereira, N. R.; Presura, R.

2018-01-01

A recently developed single-crystal x-ray spectropolarimeter has been used to record paired sets of polarization-dependent and axially resolved x-ray spectra emitted by wire array z-pinches. In this measurement, two internal planes inside a suitable crystal diffract the x-rays into two perpendicular directions that are normal to each other, thereby separating incident x-rays into their linearly polarized components. This paper gives considerations for fielding the instrument on extended sources. Results from extended sources are difficult to interpret because generally the incident x-rays are not separated properly by the crystal. This difficulty is mitigated by using a series of collimating slits to select incident x-rays that propagate in a plane of symmetry between the polarization-splitting planes. The resulting instrument and some of the spatially resolved polarized x-ray spectra recorded for a 1-MA aluminum wire array z-pinch at the Nevada Terawatt Facility at the University of Nevada, Reno will be presented.

Spatially resolved single crystal x-ray spectropolarimetry of wire array z-pinch plasmas.

PubMed

Wallace, M S; Haque, S; Neill, P; Pereira, N R; Presura, R

2018-01-01

A recently developed single-crystal x-ray spectropolarimeter has been used to record paired sets of polarization-dependent and axially resolved x-ray spectra emitted by wire array z-pinches. In this measurement, two internal planes inside a suitable crystal diffract the x-rays into two perpendicular directions that are normal to each other, thereby separating incident x-rays into their linearly polarized components. This paper gives considerations for fielding the instrument on extended sources. Results from extended sources are difficult to interpret because generally the incident x-rays are not separated properly by the crystal. This difficulty is mitigated by using a series of collimating slits to select incident x-rays that propagate in a plane of symmetry between the polarization-splitting planes. The resulting instrument and some of the spatially resolved polarized x-ray spectra recorded for a 1-MA aluminum wire array z-pinch at the Nevada Terawatt Facility at the University of Nevada, Reno will be presented.

A Search for the X-ray Counterpart of the Unidentified Gamma-ray Source 3EG J2020+4017 (2CG078+2)

NASA Technical Reports Server (NTRS)

Weisskopf, Martin; Swartz, Douglas A.; Carraminana, Alberto; Carrasco, Luis; Kaplan, David L.; Becker, Werner; Elsner, Ronald F.; Kanbach, Gottfried; ODell, Stephen L.; Tennant, Allyn F.

2006-01-01

We report observations with the Chandra X-ray Observatory of a field in the gamma-Cygni supernova remnant (SNR78.2+2.1) centered on the cataloged location of the unidentified, bright gamma-ray source 3EG J2020+4017. In this search for an X-ray counterpart to the gamma-ray source, we detected 30 X-ray sources. Of these, we found 17 strong-candidate counterparts in optical (visible through near-infrared) cataloged and an additional 3 through our optical observations. Based upon colors and (for several objects) optical spectra, nearly all the optically identified objects appear to be reddened main-sequence stars: None of the X-ray sources with an optical counterpart is a plausible X-ray counterpart to 3EG J2020+4017-if that gamma-ray source is a spin-powered pulsar. Many of the 10 X-ray sources lacking optical counterparts are likely (extragalactic) active galactic nuclei, based upon the sky density of such sources. Although one of the 10 optically unidentified X-ray sources could be the gamma-ray source, there is no auxiliary evidence supporting such an identification

UNDERSTANDING X-RAY STARS:. The Discovery of Binary X-ray Sources

NASA Astrophysics Data System (ADS)

Schreier, E. J.; Tananbaum, H.

2000-09-01

The discovery of binary X-ray sources with UHURU introduced many new concepts to astronomy. It provided the canonical model which explained X-ray emission from a large class of galactic X-ray sources: it confirmed the existence of collapsed objects as the source of intense X-ray emission; showed that such collapsed objects existed in binary systems, with mass accretion as the energy source for the X-ray emission; and provided compelling evidence for the existence of black holes. This model also provided the basis for explaining the power source of AGNs and QSOs. The process of discovery and interpretation also established X-ray astronomy as an essential sub-discipline of astronomy, beginning its incorporation into the mainstream of astronomy.

Refractive Optics for Hard X-ray Transmission Microscopy

NASA Astrophysics Data System (ADS)

Simon, M.; Ahrens, G.; Last, A.; Mohr, J.; Nazmov, V.; Reznikova, E.; Voigt, A.

2011-09-01

For hard x-ray transmission microscopy at photon energies higher than 15 keV we design refractive condenser and imaging elements to be used with synchrotron light sources as well as with x-ray tube sources. The condenser lenses are optimized for low x-ray attenuation—resulting in apertures greater than 1 mm—and homogeneous intensity distribution on the detector plane, whereas the imaging enables high-resolution (<100 nm) full-field imaging. To obtain high image quality at reasonable exposure times, custom-tailored matched pairs of condenser and imaging lenses are being developed. The imaging lenses (compound refractive lenses, CRLs) are made of SU-8 negative resist by deep x-ray lithography. SU-8 shows high radiation stability. The fabrication technique enables high-quality lens structures regarding surface roughness and arrangement precision with arbitrary 2D geometry. To provide point foci, crossed pairs of lenses are used. Condenser lenses have been made utilizing deep x-ray lithographic patterning of thick SU-8 layers, too, whereas in this case, the aperture is limited due to process restrictions. Thus, in terms of large apertures, condenser lenses made of structured and rolled polyimide film are more attractive. Both condenser types, x-ray mosaic lenses and rolled x-ray prism lenses (RXPLs), are considered to be implemented into a microscope setup. The x-ray optical elements mentioned above are characterized with synchrotron radiation and x-ray laboratory sources, respectively.

Combining THz laser excitation with resonant soft X-ray scattering at the Linac Coherent Light Source

DOE PAGES

Turner, Joshua J.; Dakovski, Georgi L.; Hoffmann, Matthias C.; ...

2015-04-11

This paper describes the development of new instrumentation at the Linac Coherent Light Source for conducting THz excitation experiments in an ultra high vacuum environment probed by soft X-ray diffraction. This consists of a cantilevered, fully motorized mirror system which can provide 600 kV cm⁻¹ electric field strengths across the sample and an X-ray detector that can span the full Ewald sphere with in-vacuum motion. The scientific applications motivated by this development, the details of the instrument, and spectra demonstrating the field strengths achieved using this newly developed system are discussed.

21 CFR 872.1810 - Intraoral source x-ray system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and is...

21 CFR 872.1810 - Intraoral source x-ray system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and is...

21 CFR 872.1810 - Intraoral source x-ray system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and is...

21 CFR 872.1810 - Intraoral source x-ray system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and is...

Development of Experimental Techniques Using LVP (Large Volume Press) at GSECARS Beamlines, Advanced Photon Source (in Japanese with English abstract)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishiyama, N.; Wang, Y.

GSECARS (GeoSoilEnviroCARS, the University of Chicago) operates a bending magnet and an undulator beamlines at Sector 13, Advanced Photon Source. Experimental technique for High Pressure X-ray Tomographic Microscope (HPXTM) using monochromatized X-rays has been developed. The module for HPXTM also has shear deformation capability, which enables us to perform HPXTM experiments for microstructure developed by shear deformation under high pressure. A combination of Deformation DIA (D-DIA) and monochromatic X-rays has been developed for quantitative deformation experiments under pressure above 10 GPa. Deformation experiments of e-iron was performed at pressures up to 19 GPa and temperatures up to 700 K.

HEAO Science Symposium

NASA Technical Reports Server (NTRS)

Dailey, C. (Editor); Johnson, W. (Editor)

1979-01-01

Scientific results from the early analysis of data from the HEAO 1 mission are presented. Development of astronomical catalogs and maps, X-ray variability, extragalactic astronomy, X-ray iron line emission, and optical identification and spectroscopy of X-ray sources are among the topics discussed. Results from HEAO 2 imaging and nonimaging instruments are included.

THE EFFECT OF SATELLITE LINES FROM THE X-RAY SOURCE ON X-RAY DIFFRACTION PEAKS

EPA Science Inventory

The article discusses the development of a method for relating reactivity to crystallite size and strain parameters obtained by the Warren-Averbach technique. EPA has been using crystallite size and strain data obtained from x-ray diffraction (XRD) peak profile analysis to predic...

Potentiality of a small and fast dense plasma focus as hard x-ray source for radiographic applications

NASA Astrophysics Data System (ADS)

Pavez, Cristian; Pedreros, José; Zambra, Marcelo; Veloso, Felipe; Moreno, José; Ariel, Tarifeño-Saldivia; Soto, Leopoldo

2012-10-01

Currently, a new generation of small plasma foci devices is being developed and researched, motivated by its potential use as portable sources of x-ray and neutron pulsed radiation for several applications. In this work, experimental results of the accumulated x-ray dose angular distribution and characterization of the x-ray source size are presented for a small and fast plasma focus device, ‘PF-400J’ (880 nF, 40 nH, 27-29 kV, ˜350 J, T/4 ˜ 300 ns). The experimental device is operated using hydrogen as the filling gas in a discharge region limited by a volume of around 80 cm3. The x-ray radiation is monitored, shot by shot, using a scintillator-photomultiplier system located outside the vacuum chamber at 2.3 m far away from the radiation emission region. The angular x-ray dose distribution measurement shows a well-defined emission cone, with an expansion angle of 5°, which is observed around the plasma focus device symmetry axis using TLD-100 crystals. The x-ray source size measurements are obtained using two image-forming aperture techniques: for both cases, one small (pinhole) and one large for the penumbral imaging. These results are in agreement with the drilling made by the energetic electron beam coming from the pinch region. Additionally, some examples of image radiographic applications are shown in order to highlight the real possibilities of the plasma focus device as a portable x-ray source. In the light of the obtained results and the scaling laws observed in plasma foci devices, we present a discussion on the potentiality and advantages of these devices as pulsed and safe sources of x-radiation for applications.

Picosecond x-ray diagnostics for third and fourth generation synchrotron sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeCamp, Matthew

2016-03-30

In the DOE-EPSCoR State/National Laboratory partnership grant ``Picosecond x-ray diagnostics for third and fourth generation synchrotron sources'' Dr. DeCamp set forth a partnership between the University of Delaware and Argonne National Laboratory. This proposal aimed to design and implement a series of experiments utilizing, or improving upon, existing time-domain hard x-ray spectroscopies at a third generation synchrotron source. Specifically, the PI put forth three experimental projects to be explored in the grant cycle: 1) implementing a picosecond ``x-ray Bragg switch'' using a laser excited nano-structured metallic film, 2) designing a robust x-ray optical delay stage for x-ray pump-probe studies atmore » a hard x-ray synchrotron source, and 3) building/installing a laser based x-ray source at the Advanced Photon Source for two-color x-ray pump-probe studies.« less

X-rays from supernova 1987A

NASA Technical Reports Server (NTRS)

Xu, Yueming; Sutherland, Peter; Mccray, Richard; Ross, Randy R.

1988-01-01

Detailed calculations of the development of the X-ray spectrum of 1987A are presented using more realistic models for the supernova composition and density structure provided by Woosley. It is shown how the emergence of the X-ray spectrum depends on the parameters of the model and the nature of its central energy source. It is shown that the soft X-ray spectrum should be dominated by a 6.4 keV Fe K(alpha) emission line that could be observed by a sensitive X-ray telescope.

21 CFR 872.1800 - Extraoral source x-ray system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended for...

21 CFR 872.1800 - Extraoral source x-ray system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended for...

21 CFR 872.1800 - Extraoral source x-ray system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended for...

Ultrahigh resolution and brilliance laser wakefield accelerator betatron x-ray source for rapid in vivo tomographic microvasculature imaging in small animal models

NASA Astrophysics Data System (ADS)

Fourmaux, Sylvain; Kieffer, Jean-Claude; Krol, Andrzej

2017-03-01

We are developing ultrahigh spatial resolution (FWHM < 2 μm) high-brilliance x-ray source for rapid in vivo tomographic microvasculature imaging micro-CT angiography (μCTA) in small animal models using optimized contrast agent. It exploits Laser Wakefield Accelerator (LWFA) betatron x-ray emission phenomenon. Ultrashort high-intensity laser pulse interacting with a supersonic gas jet produces an ion cavity ("bubble") in the plasma in the wake of the laser pulse. Electrons that are injected into this bubble gain energy, perform wiggler-like oscillations and generate burst of incoherent x-rays with characteristic duration time comparable to the laser pulse duration, continuous synchrotron-like spectral distribution that might extend to hundreds keV, very high brilliance, very small focal spot and highly directional emission in the cone-beam geometry. Such LWFA betatron x-ray source created in our lab produced 1021 -1023 photonsṡ shot-1ṡmrad-2ṡmm-2/0.1%bw with mean critical energy in the12-30 keV range. X-ray source size for a single laser shot was FWHM=1.7 μm x-ray beam divergence 20-30 mrad, and effective focal spot size for multiple shots FWHM= 2 μm. Projection images of simple phantoms and complex biological objects including insects and mice were obtained in single laser shots. We conclude that ultrahigh spatial resolution μCTA (FWHM 2 μm) requiring thousands of projection images could be accomplished using LWFA betatron x-ray radiation in approximately 40 s with our existing 220 TW laser and sub seconds with next generation of ultrafast lasers and x-ray detectors, as opposed to several hours required using conventional microfocal x-ray tubes. Thus, sub second ultrahigh resolution in vivo microtomographic microvasculature imaging (in both absorption and phase contrast mode) in small animal models of cancer and vascular diseases will be feasible with LWFA betatron x-ray source.

Ultra-high Resolution Coherent X-ray Imaging of Nano-Materials

NASA Astrophysics Data System (ADS)

Shapiro, David

A revolution is underway in the field of x-ray microscopy driven by the develop of experimental, theoretical and computational means of producing a complete description of coherent imaging systems from x-ray diffraction data. The methods being developed not only allow for full quantification and removal of all optical aberrations but also extension of the numerical aperture to the diffraction limit. One such method under intensive development is x-ray ptychography. This is a scanned probe method that reconstructs a scattering object and its illumination from coherent diffraction data. Within the first few years of development at the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory, this method has already achieved the highest resolution x-ray images ever recorded in two, three and four dimensions. With the ability of x-rays to penetrate significantly more matter than electrons, their short wavelength and their sensitivity to chemical and magnetic states of matter, x-ray ptychography is set to revolutionize how we see the nano-scale world. In this presentation I will briefly describe the technical framework for how various methods work and will give a detailed account of a practical implementation at the ALS along with various scientific applications. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

Multiwavelength study of Chandra X-ray sources in the Antennae

NASA Astrophysics Data System (ADS)

Clark, D. M.; Eikenberry, S. S.; Brandl, B. R.; Wilson, J. C.; Carson, J. C.; Henderson, C. P.; Hayward, T. L.; Barry, D. J.; Ptak, A. F.; Colbert, E. J. M.

2011-01-01

We use Wide-field InfraRed Camera (WIRC) infrared (IR) images of the Antennae (NGC 4038/4039) together with the extensive catalogue of 120 X-ray point sources to search for counterpart candidates. Using our proven frame-tie technique, we find 38 X-ray sources with IR counterparts, almost doubling the number of IR counterparts to X-ray sources that we first identified. In our photometric analysis, we consider the 35 IR counterparts that are confirmed star clusters. We show that the clusters with X-ray sources tend to be brighter, Ks≈ 16 mag, with (J-Ks) = 1.1 mag. We then use archival Hubble Space Telescope (HST) images of the Antennae to search for optical counterparts to the X-ray point sources. We employ our previous IR-to-X-ray frame-tie as an intermediary to establish a precise optical-to-X-ray frame-tie with <0.6 arcsec rms positional uncertainty. Due to the high optical source density near the X-ray sources, we determine that we cannot reliably identify counterparts. Comparing the HST positions to the 35 identified IR star cluster counterparts, we find optical matches for 27 of these sources. Using Bruzual-Charlot spectral evolutionary models, we find that most clusters associated with an X-ray source are massive, and young, ˜ 106 yr.

Hard-X-ray dark-field imaging using a grating interferometer.

PubMed

Pfeiffer, F; Bech, M; Bunk, O; Kraft, P; Eikenberry, E F; Brönnimann, Ch; Grünzweig, C; David, C

2008-02-01

Imaging with visible light today uses numerous contrast mechanisms, including bright- and dark-field contrast, phase-contrast schemes and confocal and fluorescence-based methods. X-ray imaging, on the other hand, has only recently seen the development of an analogous variety of contrast modalities. Although X-ray phase-contrast imaging could successfully be implemented at a relatively early stage with several techniques, dark-field imaging, or more generally scattering-based imaging, with hard X-rays and good signal-to-noise ratio, in practice still remains a challenging task even at highly brilliant synchrotron sources. In this letter, we report a new approach on the basis of a grating interferometer that can efficiently yield dark-field scatter images of high quality, even with conventional X-ray tube sources. Because the image contrast is formed through the mechanism of small-angle scattering, it provides complementary and otherwise inaccessible structural information about the specimen at the micrometre and submicrometre length scale. Our approach is fully compatible with conventional transmission radiography and a recently developed hard-X-ray phase-contrast imaging scheme. Applications to X-ray medical imaging, industrial non-destructive testing and security screening are discussed.

Development of a hard x-ray wavefront sensor for the EuXFEL

NASA Astrophysics Data System (ADS)

Berujon, Sebastien; Ziegler, Eric; Cojocaru, Ruxandra; Martin, Thierry

2017-05-01

We present developments on a hard X-ray wavefront sensing instrument for characterizing and monitoring the beam of the European X-ray Free Electron Lasers (EuXFEL). The pulsed nature of the intense X-ray beam delivered by this new class of facility gives rise to strong challenges for the optics and their diagnostic. In the frame of the EUCALL project Work Package 7, we are developing a sensor able to observe the beam in the X-ray energy range [8-40] keV without altering it. The sensor is based on the speckle tracking principle and employs two semi-transparent optics optimized such that their X-ray absorption is reduced. Furthermore, this instrument requires a scattering object with small random features placed in the beam and two cameras to record images of the beam at two different propagation distances. The analysis of the speckle pattern and its distortion from one image to the other allows absolute or differential wavefront recovery from pulse to pulse. Herein, we introduce the stakes and challenges of wavefront sensing at an XFEL source and explain the strategies adopted to fulfil the high requirements set by such a source.

The Development of a Simulator System and Hardware Test Bed for Deep Space X-Ray Navigation

NASA Astrophysics Data System (ADS)

Doyle, Patrick T.

2013-03-01

Currently, there is a considerable interest in developing technologies that will allow using photon measurements from celestial x-ray sources for deep space navigation. The impetus for this is that many envisioned future space missions will require spacecraft to have autonomous navigation capabilities. For missions close to Earth, Global Navigation Satellite Systems (GNSS) such as GPS are readily available for use, but for missions far from Earth, other alternatives must be provided. While existing systems such as the Deep Space Network (DSN) can be used, latencies associated with servicing a fleet of vehicles may not be compatible with some autonomous operations requiring timely updates of their navigation solution. Because of their somewhat predictable emissions, pulsars are the ideal candidates for x-ray sources that can be used to provide key parameters for navigation. Algorithms and simulation tools that will enable designing and analyzing x-ray navigation concepts are presented. The development of a compact x-ray detector system is pivotal to the eventual deployment of such navigation systems. Therefore, results of a high altitude balloon test to evaluate the design of a compact x-ray detector system are described as well.

Calibration of a time-resolved hard-x-ray detector using radioactive sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoeckl, C., E-mail: csto@lle.rochester.edu; Theobald, W.; Regan, S. P.

A four-channel, time-resolved, hard x-ray detector (HXRD) has been operating at the Laboratory for Laser Energetics for more than a decade. The slope temperature of the hot-electron population in direct-drive inertial confinement fusion experiments is inferred by recording the hard x-ray radiation generated in the interaction of the electrons with the target. Measuring the energy deposited by hot electrons requires an absolute calibration of the hard x-ray detector. A novel method to obtain an absolute calibration of the HXRD using single photons from radioactive sources was developed, which uses a thermoelectrically cooled, low-noise, charge-sensitive amplifier.

Demonstration of x-ray Thomson scattering using picosecond K-α x-ray sources in the characterization of dense heated matter

DOE PAGES

Kritcher, A. L.; Neumayer, P.; Lee, H. J.; ...

2008-10-31

Here, we present K-α x-ray Thomson scattering from shock compressed matter for use as a diagnostic in determining the temperature, density, and ionization state with picosecond resolution. The development of this source as a diagnostic as well as stringent requirements for successful K-α x-ray Thomson scattering are addressed. Here, the first elastic and inelastic scattering measurements on a medium size laser facility have been observed. We present scattering data from solid density carbon plasmas with >1X 10 5 photons in the elastic peak that validate the capability of single shot characterization of warm dense matter and the ability to usemore » this scattering source at future free electron lasers and for fusion experiments at the National Ignition Facility (NIF), LLNL.« less

Development of a stationary digital breast tomosynthesis system for clinical applications

NASA Astrophysics Data System (ADS)

Tucker, Andrew Wallace

Digital breast tomosynthesis (DBT) has been shown to be a very beneficial tool in the fight against breast cancer. However, current DBT systems have poor spatial resolution compared to full field digital mammography (FFDM), the current gold standard for screening mammography. The poor spatial resolution of DBT systems is a result of the single X-ray source design. In DBT systems a single X-ray source is rotated over an angular span in order to acquire the images needed for 3D reconstruction. The rotation of the X-ray source degrades the spatial resolution of the images. DBT systems which are approved for use in the United States for screening mammography are required to also take a full field digital mammogram with every DBT acquisition in order to compensate for the poor spatial resolution. This double exposure essentially doubles the radiation dose to patients. Over the past few years our research group has developed a carbon nanotube (CNT) based X-ray source technology. The unique nature of CNT X-ray sources allows for multiple X-ray focal spots in a single X-ray source. Using this technology we have recently developed a stationary DBT system (s-DBT) system which is capable of producing a full tomosynthesis image dataset with zero motion of the X-ray source. This system has been shown to have increased spatial resolution over other DBT systems in a laboratory setting. The goal of this thesis work was to optimize the s-DBT system, demonstrate its usefulness over other systems, and finally implement it into the clinic for a clinical trial. The s-DBT system was optimized using different image quality measurements. The optimized system was then used in a breast specimen imaging trial which compared s-DBT to magnified 2D mammography and a conventional single source DBT system. Readers preferred s-DBT to magnified 2D mammography for specimen margin delineation and mass detection, these results were not significant. Using physical measures for spatial resolution the s-DBT system was shown to have improved image quality over conventional single source DBT systems in breast tissue. A separate study showed that s-DBT could be a feasible alternative to FFDM for screening patients with breast implants. Finally, a second s-DBT system was constructed and implemented into the Department of Mammography at UNC hospitals. The first patient was imaged on the system in December of 2013.

The XMM-Newton serendipitous survey. VII. The third XMM-Newton serendipitous source catalogue

NASA Astrophysics Data System (ADS)

Rosen, S. R.; Webb, N. A.; Watson, M. G.; Ballet, J.; Barret, D.; Braito, V.; Carrera, F. J.; Ceballos, M. T.; Coriat, M.; Della Ceca, R.; Denkinson, G.; Esquej, P.; Farrell, S. A.; Freyberg, M.; Grisé, F.; Guillout, P.; Heil, L.; Koliopanos, F.; Law-Green, D.; Lamer, G.; Lin, D.; Martino, R.; Michel, L.; Motch, C.; Nebot Gomez-Moran, A.; Page, C. G.; Page, K.; Page, M.; Pakull, M. W.; Pye, J.; Read, A.; Rodriguez, P.; Sakano, M.; Saxton, R.; Schwope, A.; Scott, A. E.; Sturm, R.; Traulsen, I.; Yershov, V.; Zolotukhin, I.

2016-05-01

Context. Thanks to the large collecting area (3 ×~1500 cm2 at 1.5 keV) and wide field of view (30' across in full field mode) of the X-ray cameras on board the European Space Agency X-ray observatory XMM-Newton, each individual pointing can result in the detection of up to several hundred X-ray sources, most of which are newly discovered objects. Since XMM-Newton has now been in orbit for more than 15 yr, hundreds of thousands of sources have been detected. Aims: Recently, many improvements in the XMM-Newton data reduction algorithms have been made. These include enhanced source characterisation and reduced spurious source detections, refined astrometric precision of sources, greater net sensitivity for source detection, and the extraction of spectra and time series for fainter sources, both with better signal-to-noise. Thanks to these enhancements, the quality of the catalogue products has been much improved over earlier catalogues. Furthermore, almost 50% more observations are in the public domain compared to 2XMMi-DR3, allowing the XMM-Newton Survey Science Centre to produce a much larger and better quality X-ray source catalogue. Methods: The XMM-Newton Survey Science Centre has developed a pipeline to reduce the XMM-Newton data automatically. Using the latest version of this pipeline, along with better calibration, a new version of the catalogue has been produced, using XMM-Newton X-ray observations made public on or before 2013 December 31. Manual screening of all of the X-ray detections ensures the highest data quality. This catalogue is known as 3XMM. Results: In the latest release of the 3XMM catalogue, 3XMM-DR5, there are 565 962 X-ray detections comprising 396 910 unique X-ray sources. Spectra and lightcurves are provided for the 133 000 brightest sources. For all detections, the positions on the sky, a measure of the quality of the detection, and an evaluation of the X-ray variability is provided, along with the fluxes and count rates in 7 X-ray energy bands, the total 0.2-12 keV band counts, and four hardness ratios. With the aim of identifying the detections, a cross correlation with 228 catalogues of sources detected in all wavebands is also provided for each X-ray detection. Conclusions: 3XMM-DR5 is the largest X-ray source catalogue ever produced. Thanks to the large array of data products associated with each detection and each source, it is an excellent resource for finding new and extreme objects. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.The catalogue is available at http://cdsarc.u-strasbg.fr/viz-bin/VizieR?-meta.foot&-source=IX/46

Infrared studies of galactic center x-ray sources

NASA Astrophysics Data System (ADS)

DeWitt, Curtis

In this dissertation I use a variety of approaches to discover the nature of a subset of the nearly 10,000 X-ray point sources in the 2° x 0.8° region around the Galactic Center. I produced a JHK s source catalog of the 170 x170 region around Sgr A* an area containing 4339 of these X-ray sources, with the ISPI camera on the CTIO 4-m telescope. I cross-correlated the Chandra and ISPI catalogs to find potential near-infrared (NIR) counterparts to the X-ray sources. The extreme NIR source crowding in the field means that it is not possible to establish the authenticity of the matches with astrometry and photometry alone. I found 2137 IR/X-ray astrometrically matched sources; statistically I calculated that my catalog contains 289+/-13 true matches to soft X-ray sources and 154 +/- 39 matches to hard X-ray sources. However, the fraction of matches to hard sources that are spurious is 90%, compared to 40% for soft source matches, making the hard source NIR matches particularly challenging for spectroscopic follow-up. I statistically investigated the parameter space of matched sources and identified a set of 98 NIR matches to hard X-ray sources with reddenings consistent with the GC distance which have a 45% probability of being true counterparts. I created two additional photometric catalogs of the GC region to investigate the variability of X-ray counterparts over a time baseline of several years. I found 48 variable NIR sources matched to X-ray sources, with 2 spectroscopically confirmed to be true counterparts (1 in previous literature and one in this study). I took spectra of 46 of my best candidates for counterparts to X-ray sources toward the GC, and spectroscopically confirmed 4 sources as the authentic physical counterpart on the basis of emission lines in the H and K band spectra. These sources include a Be high mass X-ray binary located 16 pc in projection away from Sgr A*; a hard X-ray symbiotic binary located 22 pc in projection from Sgr A*; an O-type supergiant at an distance of 3.7 kpc; and an O star at the Galactic Center distance. I also identified 3 foreground X-ray source counterparts within a distance of 1 kpc which do not show obvious emission features in their spectra. However, on the basis of the low surface density of unreddened sources along the line-of-sight to the Galactic Center and our previous statistical analysis (DeWitt et al., 2010), these can be securely identified as the true counterparts to their coincident X-ray point sources. Lastly, I used the results of my matching simulations to infer the presence of 7+/-2 true counterparts within a set of late type giants that I observed without detectable emission features. I conclude from this work that the probable excess in red giant X-ray counterparts without emission lines needs to be confirmed both with larger samples of spectroscopically surveyed counterparts and more advanced statistical simulations of the match authenticity. Also, the nature of the compact object in two of my counterpart discoveries, the Be HMXB and the symbiotic binary, can be strongly constrained with X-ray spectral fitting. Lastly, I conclude that spectroscopic surveys for new X-ray source counterparts in the GC may be able to increase their efficiency by specifically targeting photometric variables and very close astrometric matches of IR/X-ray sources.

Multiwavelength Study of the Bright X-ray Source Population in the Interacting Galaxies NGC 5774/NGC 5775

NASA Technical Reports Server (NTRS)

Ghosh, Kajal K.; Swartz, Douglas A.; Tennant, Allyn F.; Saripalli, Lakshmi; Gandhi, Poshak; Foellmi, Cedric; Gutierrez, Carlos M.; Lopez-Corredoira, Martin

2006-01-01

The X-ray source population in the field of the interacting pair of galaxies NGC 5774/5775 is reported. A total of 49 discrete sources are detected, including 12 ultraluminous X-ray source candidates with lum inosities above 10(exp 39)erg/s in the 0.5 - 8.0 keV X-ray band. Several of these latter are transient X-ray sources that fall below detect ion levels in one of two X-ray observations spaced 15 months apart. X-ray source positions are mapped onto optical and radio images to sear ch for potential counterparts. Eleven sources have optically-bright c ounterparts. Optical colors are used to differentiate these sources, which are mostly located outside the optical extent of the interacting galaxies, as potential globular clusters (3 sources) and quasars (5) . Follow-up optical spectroscopy confirms two of the latter are background quasars.

Data reduction and analysis for the graphite crystal X-ray spectrometer and polarimeter experiment flown aboard OSO-8 spacecraft

NASA Technical Reports Server (NTRS)

Novick, R.

1980-01-01

The documentation and software programs developed for the reception, initial processing (quickbook), and production analysis of data obtained by solar X-ray spectroscopy, stellar spectroscopy, and X-ray polarimetry experiments on OSO-8 are listed. The effectiveness and sensitivity of the Bragg crystal scattering instruments used are assessed. The polarization data polarimetric data obtained shows that some X-ray sources are polarized and that a larger polarimeter of this type is required to perform the measurements necessary to fully understand the physics of X-ray sources. The scanning Bragg crystal spectrometer was ideally suited for studying rapidly changing solar conditions. Observations of the Crab Nebula and pulsar, Cyg X-1, Cyg X-2, Cyg X-3, Sco X-1, Cen X-3, and Her X-1 are discussed as well as of 4U1656-53 and 4U1820-30. Evidence was obtained for iron line emission from Cyg X-3.

Comparative study of x ray and microwave emissions during solar flares

NASA Technical Reports Server (NTRS)

Winglee, Robert M.

1993-01-01

The work supported by the grant consisted of two projects. The first project involved making detailed case studies of two flares using SMM data in conjunction with ground based observations. The first flare occurred at 1454 UT on June 20, 1989 and involved the eruption of a prominence near the limb. In the study we used data from many wavelength regimes including the radio, H-alpha, hard X-rays, and soft X-rays. We used a full gyrosynchrotron code to model the apparent presence of a 1.4 GHz source early in the flare that was in the form of a large coronal loop. The model results lead us to conclude that the initial acceleration occurs in small, dense loops which also produced the flare's hard X-ray emission. We also found evidence that a source at 1.4 GHz later in the event was due to second harmonic plasma emission. This source was adjacent to a leg of the prominence and comes from a dense column of material in the magnetic structure supporting the prominence. Finally, we investigated a source of microwaves and soft X-rays, occurring approximately 10 min after the hard X-ray peak, and calculate a lower limit for the density of the source. The second flare that was studied occurred at 2156 UT on June 20, 1989 and was observed with the VLA and the Owens Valley Radio Observatory (OVRO) Frequency Agile Array. We have developed a gyrosynchrotron model of the sources at flare peak using a new gyrosynchrotron approximation which is valid at very low harmonics of the gyrofrequency. We found that the accelerated particle densities of the sources decreased much more with radius from the source center than had been supposed in previous work, while the magnetic field varied less. We also used the available data to analyze a highly polarized source which appeared late in the flare. The second project involved compiling a statistical base for the relative timing of the hard X-ray peak, the turbulent and blue-shift velocities inferred from soft X-ray line emissions observed by SMM and the microwave peak as determined from ground-based observations. This timing was then used to aid the testing of newly developed global models for flares that incorporate the global magnetic topology as well as the electron dynamics that are responsible for the hard X-rays and microwaves.

Soft x-ray contact imaging of biological specimens using a laser-produced plasma as an x-ray source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, P.C.

The use of a laser-produced plasma as an x-ray source provides significant advantages over other types of sources for x-ray microradiography of, particularly, living biological specimens. The pulsed nature of the x-rays enables imaging of the specimen in a living state, and the small source size minimizes penumbral blurring. This makes it possible to make an exposure close to the source, thereby increasing the x-ray intensity. In this article, we will demonstrate the applications of x-ray contact microradiography in structural and developmental botany such as the localization of silica deposition and the floral morphologenesis of maize.

Optically Levitated Targets as a Source for High Brightness X-rays and a Platform for Mass-Limited Laser-interaction Experiments

NASA Astrophysics Data System (ADS)

Giltrap, Samuel; Stuart, Nick; Robinson, Tim; Armstrong, Chris; Hicks, George; Eardley, Sam; Gumbrell, Ed; Smith, Roland

2016-10-01

Here we report on the development of an optical levitation based x-ray and proton source, motivated by the requirement for a debris free, high spatial resolution, and low EMP source for x-ray radiography and proton production. Research at Imperial College has led to the development of a feedback controlled optical levitation trap which is capable of holding both solid (Glass beads) and liquid (silicon based oil) micro-targets ( 3-10um). The optical levitation trap has been successfully fielded in a high-intensity laser interaction experiment at Imperial College London and at the Vulcan Petawatt Laser system at the Rutherford Appleton Laboratory (RAL). Here we report on the results from that RAL run including; an x-ray source size of 10-15um with very good spherical symmetry when compared to wire targets, secondly very low EMP signal from isolated levitated targets (9 times less RF signal than a comparable wire target). At Imperial College we were also able to record an x-ray energy spectrum which produced an electron temperature of 0.48KeV, and performed interferometry of a shock evolving into a blast wave off an optically levitated droplet which allowed us to infer the electron density within the shock front.

ANS hard X-ray experiment development program. [emission from X-ray sources

NASA Technical Reports Server (NTRS)

Parsignault, D.; Gursky, H.; Frank, R.; Kubierschky, K.; Austin, G.; Paganetti, R.; Bawdekar, V.

1974-01-01

The hard X-ray (HXX) experiment is one of three experiments included in the Dutch Astronomical Netherlands Satellite, which was launched into orbit on 30 August 1974. The overall objective of the HXX experiment is the detailed study of the emission from known X-ray sources over the energy range 1.5-30keV. The instrument is capable of the following measurements: (1) spectral content over the full energy range with an energy resolution of approximately 20% and time resolution down to 4 seconds; (2) source time variability down to 4 milliseconds; (3) silicon emission lines at 1.86 and 2.00keV; (4) source location to a limit of one arc minute in ecliptic latitude; and (5) spatial structure with angular resolution of the arc minutes. Scientific aspects of experiment, engineering design and implementation of the experiment, and program history are included.

X-ray Point Source Populations in Spiral and Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Colbert, E.; Heckman, T.; Weaver, K.; Ptak, A.; Strickland, D.

2001-12-01

In the years of the Einstein and ASCA satellites, it was known that the total hard X-ray luminosity from non-AGN galaxies was fairly well correlated with the total blue luminosity. However, the origin of this hard component was not well understood. Some possibilities that were considered included X-ray binaries, extended upscattered far-infrared light via the inverse-Compton process, extended hot 107 K gas (especially in ellipitical galaxies), or even an active nucleus. Now, for the first time, we know from Chandra images that a significant amount of the total hard X-ray emission comes from individual X-ray point sources. We present here spatial and spectral analyses of Chandra data for X-ray point sources in a sample of ~40 galaxies, including both spiral galaxies (starbursts and non-starbursts) and elliptical galaxies. We shall discuss the relationship between the X-ray point source population and the properties of the host galaxies. We show that the slopes of the point-source X-ray luminosity functions are different for different host galaxy types and discuss possible reasons why. We also present detailed X-ray spectral analyses of several of the most luminous X-ray point sources (i.e., IXOs, a.k.a. ULXs), and discuss various scenarios for the origin of the X-ray point sources.

A FOURIER-TRANSFORMED BREMSSTRAHLUNG FLASH MODEL FOR THE PRODUCTION OF X-RAY TIME LAGS IN ACCRETING BLACK HOLE SOURCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kroon, John J.; Becker, Peter A., E-mail: jkroon@gmu.edu, E-mail: pbecker@gmu.edu

Accreting black hole sources show a wide variety of rapid time variability, including the manifestation of time lags during X-ray transients, in which a delay (phase shift) is observed between the Fourier components of the hard and soft spectra. Despite a large body of observational evidence for time lags, no fundamental physical explanation for the origin of this phenomenon has been presented. We develop a new theoretical model for the production of X-ray time lags based on an exact analytical solution for the Fourier transform describing the diffusion and Comptonization of seed photons propagating through a spherical corona. The resultingmore » Green's function can be convolved with any source distribution to compute the associated Fourier transform and time lags, hence allowing us to explore a wide variety of injection scenarios. We show that thermal Comptonization is able to self-consistently explain both the X-ray time lags and the steady-state (quiescent) X-ray spectrum observed in the low-hard state of Cyg X-1. The reprocessing of bremsstrahlung seed photons produces X-ray time lags that diminish with increasing Fourier frequency, in agreement with the observations for a wide range of sources.« less

Software to model AXAF-I image quality

NASA Technical Reports Server (NTRS)

Ahmad, Anees; Feng, Chen

1995-01-01

A modular user-friendly computer program for the modeling of grazing-incidence type x-ray optical systems has been developed. This comprehensive computer software GRAZTRACE covers the manipulation of input data, ray tracing with reflectivity and surface deformation effects, convolution with x-ray source shape, and x-ray scattering. The program also includes the capabilities for image analysis, detector scan modeling, and graphical presentation of the results. A number of utilities have been developed to interface the predicted Advanced X-ray Astrophysics Facility-Imaging (AXAF-I) mirror structural and thermal distortions with the ray-trace. This software is written in FORTRAN 77 and runs on a SUN/SPARC station. An interactive command mode version and a batch mode version of the software have been developed.

Analysis of the Central X-ray Source in DG Tau

NASA Astrophysics Data System (ADS)

Schneider, P. Christian; Schmitt, Jürgen H. M. M.

As a stellar X-ray source DG Tau shows two rather unusual features: A resolved X-ray jet [2] and an X-ray spectrum best described by two thermal components with different absorbing column densities, a so called "two-absorber X-ray (TAX)" morphology [1, 2]. In an effort to understand the properties of the central X-ray source in DG Tau a detailed position analysis was carried out.

Infrared Counterparts to Chandra X-Ray Sources in the Antennae

NASA Astrophysics Data System (ADS)

Clark, D. M.; Eikenberry, S. S.; Brandl, B. R.; Wilson, J. C.; Carson, J. C.; Henderson, C. P.; Hayward, T. L.; Barry, D. J.; Ptak, A. F.; Colbert, E. J. M.

2007-03-01

We use deep J (1.25 μm) and Ks (2.15 μm) images of the Antennae (NGC 4038/4039) obtained with the Wide-field InfraRed Camera on the Palomar 200 inch (5 m) telescope, together with the Chandra X-ray source list of Zezas and coworkers to search for infrared counterparts to X-ray point sources. We establish an X-ray/IR astrometric frame tie with ~0.5" rms residuals over a ~4.3' field. We find 13 ``strong'' IR counterparts brighter than Ks=17.8 mag and <1.0" from X-ray sources, and an additional 6 ``possible'' IR counterparts between 1.0'' and 1.5'' from X-ray sources. Based on a detailed study of the surface density of IR sources near the X-ray sources, we expect only ~2 of the ``strong'' counterparts and ~3 of the ``possible'' counterparts to be chance superpositions of unrelated objects. Comparing both strong and possible IR counterparts to our photometric study of ~220 IR clusters in the Antennae, we find with a >99.9% confidence level that IR counterparts to X-ray sources are ΔMKs~1.2 mag more luminous than average non-X-ray clusters. We also note that the X-ray/IR matches are concentrated in the spiral arms and ``overlap'' regions of the Antennae. This implies that these X-ray sources lie in the most ``super'' of the Antennae's super star clusters, and thus trace the recent massive star formation history here. Based on the NH inferred from the X-ray sources without IR counterparts, we determine that the absence of most of the ``missing'' IR counterparts is not due to extinction, but that these sources are intrinsically less luminous in the IR, implying that they trace a different (possibly older) stellar population. We find no clear correlation between X-ray luminosity classes and IR properties of the sources, although small-number statistics hamper this analysis.

High resolution stationary digital breast tomosynthesis using distributed carbon nanotube x-ray source array.

PubMed

Qian, Xin; Tucker, Andrew; Gidcumb, Emily; Shan, Jing; Yang, Guang; Calderon-Colon, Xiomara; Sultana, Shabana; Lu, Jianping; Zhou, Otto; Spronk, Derrek; Sprenger, Frank; Zhang, Yiheng; Kennedy, Don; Farbizio, Tom; Jing, Zhenxue

2012-04-01

The purpose of this study is to investigate the feasibility of increasing the system spatial resolution and scanning speed of Hologic Selenia Dimensions digital breast tomosynthesis (DBT) scanner by replacing the rotating mammography x-ray tube with a specially designed carbon nanotube (CNT) x-ray source array, which generates all the projection images needed for tomosynthesis reconstruction by electronically activating individual x-ray sources without any mechanical motion. The stationary digital breast tomosynthesis (s-DBT) design aims to (i) increase the system spatial resolution by eliminating image blurring due to x-ray tube motion and (ii) reduce the scanning time. Low spatial resolution and long scanning time are the two main technical limitations of current DBT technology. A CNT x-ray source array was designed and evaluated against a set of targeted system performance parameters. Simulations were performed to determine the maximum anode heat load at the desired focal spot size and to design the electron focusing optics. Field emission current from CNT cathode was measured for an extended period of time to determine the stable life time of CNT cathode for an expected clinical operation scenario. The source array was manufactured, tested, and integrated with a Selenia scanner. An electronic control unit was developed to interface the source array with the detection system and to scan and regulate x-ray beams. The performance of the s-DBT system was evaluated using physical phantoms. The spatially distributed CNT x-ray source array comprised 31 individually addressable x-ray sources covering a 30 angular span with 1 pitch and an isotropic focal spot size of 0.6 mm at full width at half-maximum. Stable operation at 28 kV(peak) anode voltage and 38 mA tube current was demonstrated with extended lifetime and good source-to-source consistency. For the standard imaging protocol of 15 views over 14, 100 mAs dose, and 2 × 2 detector binning, the projection resolution along the scanning direction increased from 4.0 cycles/mm [at 10% modulation-transfer-function (MTF)] in DBT to 5.1 cycles/mm in s-DBT at magnification factor of 1.08. The improvement is more pronounced for faster scanning speeds, wider angular coverage, and smaller detector pixel sizes. The scanning speed depends on the detector, the number of views, and the imaging dose. With 240 ms detector readout time, the s-DBT system scanning time is 6.3 s for a 15-view, 100 mAs scan regardless of the angular coverage. The scanning speed can be reduced to less than 4 s when detectors become faster. Initial phantom studies showed good quality reconstructed images. A prototype s-DBT scanner has been developed and evaluated by retrofitting the Selenia rotating gantry DBT scanner with a spatially distributed CNT x-ray source array. Preliminary results show that it improves system spatial resolution substantially by eliminating image blur due to x-ray focal spot motion. The scanner speed of s-DBT system is independent of angular coverage and can be increased with faster detector without image degration. The accelerated lifetime measurement demonstrated the long term stability of CNT x-ray source array with typical clinical operation lifetime over 3 years.

The Chandra Source Catalog

NASA Astrophysics Data System (ADS)

Evans, Ian; Primini, Francis A.; Glotfelty, Kenny J.; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Davis, John E.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G., II; Grier, John D.; Hain, Roger; Hall, Diane M.; Harbo, Peter N.; He, Xiang Qun (Helen); Houck, John C.; Karovska, Margarita; Kashyap, Vinay L.; Lauer, Jennifer; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph B.; Mitschang, Arik W.; Morgan, Douglas L.; Mossman, Amy E.; Nichols, Joy S.; Nowak, Michael A.; Plummer, David A.; Refsdal, Brian L.; Rots, Arnold H.; Siemiginowska, Aneta L.; Sundheim, Beth A.; Tibbetts, Michael S.; van Stone, David W.; Winkelman, Sherry L.; Zografou, Panagoula

2009-09-01

The first release of the Chandra Source Catalog (CSC) was published in 2009 March, and includes information about 94,676 X-ray sources detected in a subset of public ACIS imaging observations from roughly the first eight years of the Chandra mission. This release of the catalog includes point and compact sources with observed spatial extents <˜30''.The CSC is a general purpose virtual X-ray astrophysics facility that provides access to a carefully selected set of generally useful quantities for individual X-ray sources, and is designed to satisfy the needs of a broad-based group of scientists, including those who may be less familiar with astronomical data analysis in the X-ray regime.The catalog (1) provides access to the best estimates of the X-ray source properties for detected sources, with good scientific fidelity, and directly supports medium sophistication scientific analysis on using the individual source data; (2) facilitates analysis of a wide range of statistical properties for classes of X-ray sources; (3) provides efficient access to calibrated observational data and ancillary data products for individual X-ray sources, so that users can perform detailed further analysis using existing tools; and (4) includes real X-ray sources detected with flux significance greater than a predefined threshold, while maintaining the number of spurious sources at an acceptable level. For each detected X-ray source, the CSC provides commonly tabulated quantities, including source position, extent, multi-band fluxes, hardness ratios, and variability statistics, derived from the observations in which the source is detected. In addition to these traditional catalog elements, for each X-ray source the CSC includes an extensive set of file-based data products that can be manipulated interactively, including source images, event lists, light curves, and spectra from each observation in which a source is detected.

New developments and applications of intense pulsed radiation sources at Sandia National Laboratories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cook, D.

In the past thirty-six months, tremendous strides have been made in x-ray production using high-current z-pinches. Today, the x-ray energy (1.9 MJ) and power (200 TW) output of the Z accelerator (formerly PBFA-II) is the largest available in the laboratory. These z-pinch x-ray sources are being developed for research into the physics of high energy density plasmas of interest in weapon behavior and in inertial confinement fusion. Beyond the Z accelerator current of 20 MA, an extrapolation to the X-1 accelerator level of 60 MA may have the potential to drive high-yield ICF reactions at affordable cost if several challengingmore » technical problems can be overcome. New developments have also taken place at Sandia in the area of high current, mm-diameter electron beams for advanced hydrodynamic radiography. On SABRE, x-ray spot diameters were less than 2 mm with a dose of 100 R at 1 meter in a 40 ns pulse.« less

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Hydrodynamical and Spectral Simulations of HMXB Winds

NASA Astrophysics Data System (ADS)

Mauche, Christopher W.; Liedahl, D. A.; Plewa, T.

2006-09-01

We describe the results of a research program to develop improved models of the X-ray spectra of cosmic sources such as X-ray binaries, CVs, and AGN in which UV line-driven mass flows are photoionized by an X-ray source. Work to date has focused on high-mass X-ray binaries (HMXBs) and on Vela X-1 in particular, for which there are high-quality Chandra HETG spectra in the archive. Our research program combines FLASH hydrodynamic calculations, XSTAR photoionization calculations, HULLAC atomic data, improved calculations of the line force multiplier, X-ray emission models appropriate to X-ray photoionized plasmas, and Monte Carlo radiation transport. We will present movies of the relevant physical quantities (density, temperature, ionization parameter, velocity) from a FLASH two-dimensional time-dependent simulation of Vela X-1, maps showing the emissivity distributions of the X-ray emission lines, and a preliminary comparison of the resulting synthetic spectra to the Chandra HETG spectra. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

An adjustable short-focal length, high-gradient PMQ electron-beam final-focus system for the PLEIADES ultra-fast x-ray Thomson source

NASA Astrophysics Data System (ADS)

Lim, Jae-Ku

In the span of a 100 year since the discovery of first x-rays by Roentgen that won him the first Nobel prize in physics, several types of radiation sources have been developed. Currently, radiations at extremely short wavelengths have only been accessed at synchrotron radiation sources. However, the current 3rd generation synchrotron sources can only produce x-rays of energy up to 60 keV and pulse lengths of several picoseconds long. But needs for shorter wavelength and shorter pulse duration radiations demanded by scientists to understand the nature of matter at atomic/molecular scale initiated the new scientific research for the production of sub-picosecond, hard x-rays. At the Lawrence Livermore National Laboratory, a Thomson x-ray source in the backscattering mode---a head-on collision between a high intensity Ti:Sapphire Chirped Pulse Amplification laser and a relativistic electron beam---called the PLEIADES (Picosecond Laser-Electron Inter-Action for the Dynamical Evaluation of Structures) laboratory has been developed. Early works demonstrated the production of quasi-monochromatic, femto-second long, hard x-rays. Initially reported x-ray flux was in the low range of 105--10 6 photons per shot. During the early stage of PLEIADES experiments, 15 T/m electromagnet final focusing quadrupoles (in a triplet lattice configuration) were employed to focus the beam to a 40-50 mum spot-size. A larger focal spot-size beam has a low-density of electron particles available at the interaction with incident photons, which leads to a low scattering probability. The current dissertation shows that by employing a 560 T/m PMQ (Permanent-Magnet Quadrupole) final focus system, an electron beam as small as 10-20 mum can be achieved. The implementation of this final focus system demonstrated the improvement of the total x-ray flux by two orders of magnitude. The PMQ final focus system also produced small electron beams consistently over 30-100 MeV electron beam energy, which enabled the production of x-ray energy over 40-140 keV. In this dissertation, the PLEIADES Thomson x-ray facility will be described in detail includes the 100 MeV linac and the FALCON laser system. Later, we will discuss the design, construction and implementation of the PMQ final focus system in the beamline. The measurement of electron beam parameters before and after the final focus system will be presented. The beam measurements at the interaction region were accomplished with the use of both OTR (Optical Transition Radiation) imaged by a CCD camera and the fast streak camera for respective spatial and temporal alignments. The theoretical analysis in "real beam" effects and spacetime beam jitter effects will be given to help understand the observations. A 3D simulation tool developed for x-ray data analysis was used to provide direct comparisons with the x-ray flux, spectrum distribution and transverse x-ray profile.

Noise and sensitivity of x-ray framing cameras at Nike (abstract)

NASA Astrophysics Data System (ADS)

Pawley, C. J.; Deniz, A. V.; Lehecka, T.

1999-01-01

X-ray framing cameras are the most widely used tool for radiographing density distributions in laser and Z-pinch driven experiments. The x-ray framing cameras that were developed specifically for experiments on the Nike laser system are described. One of these cameras has been coupled to a CCD camera and was tested for resolution and image noise using both electrons and x rays. The largest source of noise in the images was found to be due to low quantum detection efficiency of x-ray photons.

Refractive optics to compensate x-ray mirror shape-errors

NASA Astrophysics Data System (ADS)

Laundy, David; Sawhney, Kawal; Dhamgaye, Vishal; Pape, Ian

2017-08-01

Elliptically profiled mirrors operating at glancing angle are frequently used at X-ray synchrotron sources to focus X-rays into sub-micrometer sized spots. Mirror figure error, defined as the height difference function between the actual mirror surface and the ideal elliptical profile, causes a perturbation of the X-ray wavefront for X- rays reflecting from the mirror. This perturbation, when propagated to the focal plane results in an increase in the size of the focused beam. At Diamond Light Source we are developing refractive optics that can be used to locally cancel out the wavefront distortion caused by figure error from nano-focusing elliptical mirrors. These optics could be used to correct existing optical components on synchrotron radiation beamlines in order to give focused X-ray beam sizes approaching the theoretical diffraction limit. We present our latest results showing measurement of the X-ray wavefront error after reflection from X-ray mirrors and the translation of the measured wavefront into a design for refractive optical elements for correction of the X-ray wavefront. We show measurement of the focused beam with and without the corrective optics inserted showing reduction in the size of the focus resulting from the correction to the wavefront.

The Mapping X-Ray Fluorescence Spectrometer (MAPX)

NASA Technical Reports Server (NTRS)

Blake, David; Sarrazin, Philippe; Bristow, Thomas; Downs, Robert; Gailhanou, Marc; Marchis, Franck; Ming, Douglas; Morris, Richard; Sole, Vincente Armando; Thompson, Kathleen;

X-ray microscopy of live biological micro-organisms

NASA Astrophysics Data System (ADS)

Raja Al-Ani, Ma'an Nassar

Real-time, compact x-ray microscopy has the potential to benefit many scientific fields, including microbiology, pharmacology, organic chemistry, and physics. Single frame x-ray micro-radiography, produced by a compact, solid-state laser plasma source, allows scientists to use x-ray emission for elemental analysis, and to observe biological specimens in their natural state. In this study, x-ray images of mouse kidney tissue, live bacteria, Pseudomonas aeruginosa and Burkholderia cepacia, and the bacteria's interaction with the antibiotic gentamicin, are examined using x-ray microscopy. For the purposes of comparing between confocal microscopy and x-ray microscopy, we introduced to our work the technique of gold labeling. Indirect immunofluorescence staining and immuno-gold labeling were applied on human lymphocytes and human tumor cells. Differential interference contrast microscopy (DIC) showed the lymphocyte body and nucleus, as did x-ray microscopy. However, the high resolution of x-ray microscopy allows us to differentiate between the gold particles bound to the antibodies and the free gold. A compact, tabletop Nd: glass laser is used in this study to produce x-rays from an Yttrium target. An atomic force microscope is used to scan the x-ray images from the developed photo-resist. The use of compact, tabletop laser plasma sources, in conjunction with x-ray microscopy, is a new technique that has great potential as a flexible, user-friendly scientific research tool.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winnek, D.F.

A method and apparatus for making X-ray photographs which can be viewed in three dimensions with the use of a lenticular screen. The apparatus includes a linear tomograph having a moving X-ray source on one side of a support on which an object is to be placed so that X-rays can pass through the object to the opposite side of the support. A movable cassette on the opposite side of the support moves in a direction opposite to the direction of travel of the X-ray source as the source moves relative to the support. The cassette has an intensifying screen,more » a grating mask provided with uniformly spaced slots for passing X-rays, a lenticular member adjacent to the mask, and a photographic emulsion adjacent to the opposite side of the lenticular member. The cassette has a power device for moving the lenticular member and the emulsion relative to the mask a distance equal to the spacing between a pair of adjacent slots in the mask. The X-rays from the source, after passing through an object on the support, pass into the cassette through the slots of the mask and are focused on the photographic emulsion to result in a continuum of X-ray views of the object. When the emulsion is developed and viewed through the lenticular member, the object can be seen in three dimensions.« less

Katherine E. Weimer Award: X-ray light sources from laser-plasma and laser-electron interaction: development and applications

NASA Astrophysics Data System (ADS)

Albert, Felicie

2017-10-01

Bright sources of x-rays, such as synchrotrons and x-ray free electron lasers (XFEL) are transformational tools for many fields of science. They are used for biology, material science, medicine, or industry. Such sources rely on conventional particle accelerators, where electrons are accelerated to gigaelectronvolts (GeV) energies. The accelerated particles are wiggled in magnetic structures to emit x-ray radiation that is commonly used for molecular crystallography, fluorescence studies, chemical analysis, medical imaging, and many other applications. One of the drawbacks of these machines is their size and cost, because electric field gradients are limited to about 100 V/M in conventional accelerators. Particle acceleration in laser-driven plasmas is an alternative to generate x-rays via betatron emission, Compton scattering, or bremsstrahlung. A plasma can sustain electrical fields many orders of magnitude higher than that in conventional radiofrequency accelerator structures. When short, intense laser pulses are focused into a gas, it produces electron plasma waves in which electrons can be trapped and accelerated to GeV energies. X-ray sources, driven by electrons from laser-wakefield acceleration, have unique properties that are analogous to synchrotron radiation, with a 1000-fold shorter pulse. An important use of x-rays from laser plasma accelerators is in High Energy Density (HED) science, which requires laser and XFEL facilities to create in the laboratory extreme conditions of temperatures and pressures that are usually found in the interiors of stars and planets. To diagnose such extreme states of matter, the development of efficient, versatile and fast (sub-picosecond scale) x-ray probes has become essential. In these experiments, x-ray photons can pass through dense material, and absorption of the x-rays can be directly measured, via spectroscopy or imaging, to inform scientists about the temperature and density of the targets being studied. Performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344, supported by the LLNL LDRD program (16ERD024), and by the DOE Office Science Early Career Research Program (SCW1575).

Development of a position sensitive X-ray detector for use in a light weight X-ray diffractometer

NASA Technical Reports Server (NTRS)

Semmler, R. A.

1971-01-01

A position sensitive proportional counter for use in an X-ray diffractometer is developed to permit drastic reductions in the power and weight requirements of the X-ray source and the elimination of the power, weight, and complexity of a moving slit. The final detector constructed and tested has a window spanning 138 and a free standing anode curved along an arc of 7.1 cm radius. Demonstration spectra of a quartz sample in a Debye-Sherrer geometry indicate a spatial resolution of 0.4 - 0.5 mm (0.3 - 0.4 theta). The lunar diffractometer consumed 25 watts in the X-ray generator and weighed about 20 pounds.

Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source

PubMed Central

Munke, Anna; Andreasson, Jakob; Aquila, Andrew; Awel, Salah; Ayyer, Kartik; Barty, Anton; Bean, Richard J.; Berntsen, Peter; Bielecki, Johan; Boutet, Sébastien; Bucher, Maximilian; Chapman, Henry N.; Daurer, Benedikt J.; DeMirci, Hasan; Elser, Veit; Fromme, Petra; Hajdu, Janos; Hantke, Max F.; Higashiura, Akifumi; Hogue, Brenda G.; Hosseinizadeh, Ahmad; Kim, Yoonhee; Kirian, Richard A.; Reddy, Hemanth K.N.; Lan, Ti-Yen; Larsson, Daniel S.D.; Liu, Haiguang; Loh, N. Duane; Maia, Filipe R.N.C.; Mancuso, Adrian P.; Mühlig, Kerstin; Nakagawa, Atsushi; Nam, Daewoong; Nelson, Garrett; Nettelblad, Carl; Okamoto, Kenta; Ourmazd, Abbas; Rose, Max; van der Schot, Gijs; Schwander, Peter; Seibert, M. Marvin; Sellberg, Jonas A.; Sierra, Raymond G.; Song, Changyong; Svenda, Martin; Timneanu, Nicusor; Vartanyants, Ivan A.; Westphal, Daniel; Wiedorn, Max O.; Williams, Garth J.; Xavier, Paulraj Lourdu; Yoon, Chun Hong; Zook, James

2016-01-01

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a well-characterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 μm diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 Ångström were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here. PMID:27478984

Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source

DOE PAGES

Munke, Anna; Andreasson, Jakob; Aquila, Andrew; ...

2016-08-01

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a well-characterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 μm diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 Ångström were recorded. Here, the diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB)more » as a resource for algorithm development, the contents of which are described here.« less

Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source.

PubMed

Munke, Anna; Andreasson, Jakob; Aquila, Andrew; Awel, Salah; Ayyer, Kartik; Barty, Anton; Bean, Richard J; Berntsen, Peter; Bielecki, Johan; Boutet, Sébastien; Bucher, Maximilian; Chapman, Henry N; Daurer, Benedikt J; DeMirci, Hasan; Elser, Veit; Fromme, Petra; Hajdu, Janos; Hantke, Max F; Higashiura, Akifumi; Hogue, Brenda G; Hosseinizadeh, Ahmad; Kim, Yoonhee; Kirian, Richard A; Reddy, Hemanth K N; Lan, Ti-Yen; Larsson, Daniel S D; Liu, Haiguang; Loh, N Duane; Maia, Filipe R N C; Mancuso, Adrian P; Mühlig, Kerstin; Nakagawa, Atsushi; Nam, Daewoong; Nelson, Garrett; Nettelblad, Carl; Okamoto, Kenta; Ourmazd, Abbas; Rose, Max; van der Schot, Gijs; Schwander, Peter; Seibert, M Marvin; Sellberg, Jonas A; Sierra, Raymond G; Song, Changyong; Svenda, Martin; Timneanu, Nicusor; Vartanyants, Ivan A; Westphal, Daniel; Wiedorn, Max O; Williams, Garth J; Xavier, Paulraj Lourdu; Yoon, Chun Hong; Zook, James

2016-08-01

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a well-characterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 μm diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 Ångström were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here.

The Polarimeter for Relativistic Astrophysical X-ray Sources

NASA Astrophysics Data System (ADS)

Jahoda, Keith; Kallman, Timothy R.; Kouveliotou, Chryssa; Angelini, Lorella; Black, J. Kevin; Hill, Joanne E.; Jaeger, Theodore; Kaaret, Philip E.; Markwardt, Craig B.; Okajima, Takashi; Petre, Robert; Schnittman, Jeremy; Soong, Yang; Strohmayer, Tod E.; Tamagawa, Toru; Tawara, Yuzuru

2016-07-01

The Polarimeter for Relativistic Astrophysical X-ray Sources (PRAXyS) is one of three Small Explorer (SMEX) missions selected by NASA for Phase A study, with a launch date in 2020. The PRAXyS Observatory exploits grazing incidence X-ray mirrors and Time Projection Chamber Polarimeters capable of measuring the linear polarization of cosmic X-ray sources in the 2-10 keV band. PRAXyS combines well-characterized instruments with spacecraft rotation to ensure low systematic errors. The PRAXyS payload is developed at the Goddard Space Flight Center with the Johns Hopkins University Applied Physics Laboratory, University of Iowa, and RIKEN (JAXA) collaborating on the Polarimeter Assembly. The LEOStar-2 spacecraft bus is developed by Orbital ATK, which also supplies the extendable optical bench that enables the Observatory to be compatible with a Pegasus class launch vehicle. A nine month primary mission will provide sensitive observations of multiple black hole and neutron star sources, where theory predicts polarization is a strong diagnostic, as well as exploratory observations of other high energy sources. The primary mission data will be released to the community rapidly and a Guest Observer extended mission will be vigorously proposed.

Use of electron cyclotron resonance x-ray source for nondestructive testing application

NASA Astrophysics Data System (ADS)

Baskaran, R.; Selvakumaran, T. S.

2006-03-01

Electron cyclotron resonance (ECR) technique is being used for generating x rays in the low-energy region (<150keV). Recently, the source is used for the calibration of thermoluminescent dosimetry (TLD) badges. In order to qualify the ECR x-ray source for imaging application, the source should give uniform flux over the area under study. Lead collimation arrangement is made to get uniform flux. The flux profile is measured using a teletector at different distance from the port and uniform field region of 10×10cm2 has been marked at 20cm from the x-ray exit port. A digital-to-analog converter (DAC) circuit pack is used for examining the source performance. The required dose for nondestructive testing examination has been estimated using a hospital x-ray machine and it is found to be 0.05mSv. Our source experimental parameters are tuned and the DAC circuit pack was exposed for nearly 7min to get the required dose value. The ECR x-ray source operating parameters are argon pressure: 10-5Torr, microwave power: 350W, and coil current: 0A. The effective energy of the x-ray spectrum is nearly 40keV. The x-ray images obtained from ECR x-ray source and hospital medical radiography machine are compared. It is found that the image obtained from ECR x-ray source is suitable for NDT application.

Polarimeter for Low Energy X-ray Astrophysical Sources (PLEXAS)

NASA Technical Reports Server (NTRS)

Murray, Stephen S.; Pierce, David L. (Technical Monitor)

2002-01-01

The Polarimeter for Low Energy X-ray Astrophysical Sources (PLEXAS) is an astrophysics mission concept for measuring the polarization of X-ray sources at low energies below the C-K band (less than 277 eV). PLEXAS uses the concept of variations in the reflectivity of a multilayered X-ray telescope as a function of the orientation of an X-rays polarization vector with respect to the reflecting surface of the optic. By selecting an appropriate multilayer, and rotating the X-ray telescope while pointing to a source, there will be a modulation in the source intensity, as measured at the focus of the telescope, which is proportional to the degree of polarization in the source.

Determination of the mass of globular cluster X-ray sources

NASA Technical Reports Server (NTRS)

Grindlay, J. E.; Hertz, P.; Steiner, J. E.; Murray, S. S.; Lightman, A. P.

1984-01-01

The precise positions of the luminous X-ray sources in eight globular clusters have been measured with the Einstein X-Ray Observatory. When combined with similarly precise measurements of the dynamical centers and core radii of the globular clusters, the distribution of the X-ray source mass is determined to be in the range 0.9-1.9 solar mass. The X-ray source positions and the detailed optical studies indicate that (1) the sources are probably all of similar mass, (2) the gravitational potentials in these high-central density clusters are relatively smooth and isothermal, and (3) the X-ray sources are compact binaries and are probably formed by tidal capture.

Inner-shell/subshell photoionization cross section measurements using a gamma excited variable energy X-ray source

NASA Astrophysics Data System (ADS)

Sood, B. S.; Allawadhi, K. L.; Arora, S. K.

1982-02-01

The method developed for the determination of K/L shell photoionization cross sections in various elements, 39 ≤ Z ≤ 92, in the characteristic X-ray energy region using a gamma excited variable energy X-ray source has been used for the measurement of L III subshell photoionization cross sections in Pb, Th and U. The measurements are made at the K X-ray energies of Rb, Nb and Mo, since these are able to excite selectively the L III subshells of Pb, Th and U, respectively. The results, when compared with theoretical calculations of Scofield, are found to agree within the uncertainties of determination.

Discovery of a Hand X-Ray Source, SAX J0635+0533, in the Error Box of the Gamma-Ray Source 2EG J0635+0521

NASA Technical Reports Server (NTRS)

Kaaret, P.; Piraino, S.; Halpern, Jules P.; Eracleous, M.; Oliversen, Ronald (Technical Monitor)

2001-01-01

We have discovered an X-ray source, SAX J0635+0533, with a hard spectrum within the error box of the GeV gamma-ray source in Monoceros, 2EG J0635+0521. The unabsorbed flux from the source is 1.2 x 10(exp -11) ergs /sq cm s in the 2-10 keV band. The X-ray spectrum is consistent with a simple power-law model with absorption. The photon index is 1.50 +/- 0.08, and we detect emission out to 40 keV. Optical observations identify a counterpart with a V magnitude of 12.8. The counterpart has broad emission lines and the colors of an early B-type star. If the identification of the X-ray/optical source with the gamma-ray source is correct, then the source would be a gamma-ray-emitting X-ray binary.

Status and expected perfomance of the MAXI mission for the JEM/ISS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kataoka, J.; Kawai, N.

2008-12-24

MAXI (Monitor of All-sky X-ray Image) is the first payload to be attached on JEM-EF (Kibo exposed facility) of ISS. It provides an all sky X-ray image every ISS orbit. Only with a few weeks scan, MAXI is expected to make a milli-Crab X-ray all sky map excluding bright region around the sun. Thus, MAXI does not only inform X-ray novae and transients rapidly to world astronomers if once they occur, but also observes long-term variability of Galact ic and extra-Galactic X-ray sources. MAXI also provides an X-ray source catalogue at that time with diffuse cosmic X-ray background. MAXI consistsmore » of two kinds of detectors, position sensitive gas-proportional counters for 2-30 keV X-rays and CCD cameras for 0.5-10 keV X-rays. All instruments of MAXI are now in final phase of pre-launching tests of their flight modules. We are also carrying out performance tests for X-ray detectors and collimators. Data processing and analysis software including alert system on ground are being developed by mission team. In this paper we report an overview of final instruments of MAXI and capability of MAXI.« less

Development of an X-ray imaging system to prevent scintillator degradation for white synchrotron radiation.

PubMed

Zhou, Tunhe; Wang, Hongchang; Connolley, Thomas; Scott, Steward; Baker, Nick; Sawhney, Kawal

2018-05-01

The high flux of the white X-ray beams from third-generation synchrotron light sources can significantly benefit the development of high-speed X-ray imaging, but can also bring technical challenges to existing X-ray imaging systems. One prevalent problem is that the image quality deteriorates because of dust particles accumulating on the scintillator screen during exposure to intense X-ray radiation. Here, this problem has been solved by embedding the scintillator in a flowing inert-gas environment. It is also shown that the detector maintains the quality of the captured images even after days of X-ray exposure. This modification is cost-efficient and easy to implement. Representative examples of applications using the X-ray imaging system are also provided, including fast tomography and multimodal phase-contrast imaging for biomedical and geological samples. open access.

Development of an X-ray imaging system to prevent scintillator degradation for white synchrotron radiation

PubMed Central

Zhou, Tunhe; Wang, Hongchang; Scott, Steward

2018-01-01

The high flux of the white X-ray beams from third-generation synchrotron light sources can significantly benefit the development of high-speed X-ray imaging, but can also bring technical challenges to existing X-ray imaging systems. One prevalent problem is that the image quality deteriorates because of dust particles accumulating on the scintillator screen during exposure to intense X-ray radiation. Here, this problem has been solved by embedding the scintillator in a flowing inert-gas environment. It is also shown that the detector maintains the quality of the captured images even after days of X-ray exposure. This modification is cost-efficient and easy to implement. Representative examples of applications using the X-ray imaging system are also provided, including fast tomography and multimodal phase-contrast imaging for biomedical and geological samples. PMID:29714191

The ROSAT Deep Survey. 2; Optical Identification, Photometry and Spectra of X-Ray Sources in the Lockman Field

NASA Technical Reports Server (NTRS)

Schmidt, M.; Hasinger, G.; Gunn, J.; Schneider, D.; Burg, R.; Giacconi, R.; Lehmann, I.; MacKenty, J.; Truemper, J.; Zamorani, G.

1998-01-01

The ROSAT Deep Survey includes a complete sample of 50 X-ray sources with fluxes in the 0.5 - 2 keV band larger than 5.5 x 10(exp -15)erg/sq cm/s in the Lockman field (Hasinger et al., Paper 1). We have obtained deep broad-band CCD images of the field and spectra of many optical objects near the positions of the X-ray sources. We define systematically the process leading to the optical identifications of the X-ray sources. For this purpose, we introduce five identification (ID) classes that characterize the process in each case. Among the 50 X-ray sources, we identify 39 AGNs, 3 groups of galaxies, 1 galaxy and 3 galactic stars. Four X-ray sources remain unidentified so far; two of these objects may have an unusually large ratio of X-ray to optical flux.

Chandra Deep X-ray Observation of a Typical Galactic Plane Region and Near-Infrared Identification

NASA Technical Reports Server (NTRS)

Ebisawa, K.; Tsujimoto, M.; Paizis, A.; Hamaguichi, K.; Bamba, A.; Cutri, R.; Kaneda, H.; Maeda, Y.; Sato, G.; Senda, A.

2004-01-01

Using the Chandra Advanced CCD Imaging Spectrometer Imaging array (ACIS-I), we have carried out a deep hard X-ray observation of the Galactic plane region at (l,b) approx. (28.5 deg,0.0 deg), where no discrete X-ray source has been reported previously. We have detected 274 new point X-ray sources (4 sigma confidence) as well as strong Galactic diffuse emission within two partidly overlapping ACIS-I fields (approx. 250 sq arcmin in total). The point source sensitivity was approx. 3 x 10(exp -15)ergs/s/sq cm in the hard X-ray band (2-10 keV and approx. 2 x 10(exp -16) ergs/s/sq cm in the soft band (0.5-2 keV). Sum of all the detected point source fluxes account for only approx. 10 % of the total X-ray fluxes in the field of view. In order to explain the total X-ray fluxes by a superposition of fainter point sources, an extremely rapid increase of the source population is required below our sensitivity limit, which is hardly reconciled with any source distribution in the Galactic plane. Therefore, we conclude that X-ray emission from the Galactic plane has truly diffuse origin. Only 26 point sources were detected both in the soft and hard bands, indicating that there are two distinct classes of the X-ray sources distinguished by the spectral hardness ratio. Surface number density of the hard sources is only slightly higher than observed at the high Galactic latitude regions, strongly suggesting that majority of the hard X-ray sources are active galaxies seen through the Galactic plane. Following the Chandra observation, we have performed a near-infrared (NIR) survey with SOFI at ESO/NTT to identify these new X-ray sources. Since the Galactic plane is opaque in NIR, we did not see the background extragalactic sources in NIR. In fact, only 22 % of the hard sources had NIR counterparts which are most likely to be Galactic origin. Composite X-ray energy spectrum of those hard X-ray sources having NIR counterparts exhibits a narrow approx. 6.7 keV iron emission line, which is a signature of Galactic quiescent cataclysmic variables (CVs).

X-Band RF Gun Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vlieks, Arnold; Dolgashev, Valery; Tantawi, Sami

In support of the MEGa-ray program at LLNL and the High Gradient research program at SLAC, a new X-band multi-cell RF gun is being developed. This gun, similar to earlier guns developed at SLAC for Compton X-ray source program, will be a standing wave structure made of 5.5 cells operating in the pi mode with copper cathode. This gun was designed following criteria used to build SLAC X-band high gradient accelerating structures. It is anticipated that this gun will operate with surface electric fields on the cathode of 200 MeV/m with low breakdown rate. RF will be coupled into themore » structure through a final cell with symmetric duel feeds and with a shape optimized to minimize quadrupole field components. In addition, geometry changes to the original gun, operated with Compton X-ray source, will include a wider RF mode separation, reduced surface electric and magnetic fields.« less

X-ray imaging detectors for synchrotron and XFEL sources

PubMed Central

Hatsui, Takaki; Graafsma, Heinz

2015-01-01

Current trends for X-ray imaging detectors based on hybrid and monolithic detector technologies are reviewed. Hybrid detectors with photon-counting pixels have proven to be very powerful tools at synchrotrons. Recent developments continue to improve their performance, especially for higher spatial resolution at higher count rates with higher frame rates. Recent developments for X-ray free-electron laser (XFEL) experiments provide high-frame-rate integrating detectors with both high sensitivity and high peak signal. Similar performance improvements are sought in monolithic detectors. The monolithic approach also offers a lower noise floor, which is required for the detection of soft X-ray photons. The link between technology development and detector performance is described briefly in the context of potential future capabilities for X-ray imaging detectors. PMID:25995846

Capsule implosions for continuum x-ray backlighting of opacity samples at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Opachich, Y. P.; Heeter, R. F.; Barrios, M. A.; Garcia, E. M.; Craxton, R. S.; King, J. A.; Liedahl, D. A.; McKenty, P. W.; Schneider, M. B.; May, M. J.; Zhang, R.; Ross, P. W.; Kline, J. L.; Moore, A. S.; Weaver, J. L.; Flippo, K. A.; Perry, T. S.

2017-06-01

Direct drive implosions of plastic capsules have been performed at the National Ignition Facility to provide a broad-spectrum (500-2000 eV) X-ray continuum source for X-ray transmission spectroscopy. The source was developed for the high-temperature plasma opacity experimental platform. Initial experiments using 2.0 mm diameter polyalpha-methyl styrene capsules with ˜20 μm thickness have been performed. X-ray yields of up to ˜1 kJ/sr have been measured using the Dante multichannel diode array. The backlighter source size was measured to be ˜100 μm FWHM, with ˜350 ps pulse duration during the peak emission stage. Results are used to simulate transmission spectra for a hypothetical iron opacity sample at 150 eV, enabling the derivation of photometrics requirements for future opacity experiments.

Do solar decimetric spikes originate in coronal X-ray sources?

NASA Astrophysics Data System (ADS)

Battaglia, M.; Benz, A. O.

2009-06-01

Context: In the standard solar flare scenario, a large number of particles are accelerated in the corona. Nonthermal electrons emit both X-rays and radio waves. Thus, correlated signatures of the acceleration process are predicted at both wavelengths, coinciding either close to the footpoints of a magnetic loop or near the coronal X-ray source. Aims: We attempt to study the spatial connection between coronal X-ray emission and decimetric radio spikes to determine the site and geometry of the acceleration process. Methods: The positions of radio-spike sources and coronal X-ray sources are determined and analyzed in a well-observed limb event. Radio spikes are identified in observations from the Phoenix-2 spectrometer. Data from the Nançay radioheliograph are used to determine the position of the radio spikes. RHESSI images in soft and hard X-ray wavelengths are used to determine the X-ray flare geometry. Those observations are complemented by images from GOES/SXI. Results: We find that the radio emission originates at altitudes much higher than the coronal X-ray source, having an offset from the coronal X-ray source amounting to 90´´ and to 113´´ and 131´´ from the two footpoints, averaged over time and frequency. Conclusions: Decimetric spikes do not originate from coronal X-ray flare sources contrary to previous expectations. However, the observations suggest a causal link between the coronal X-ray source, related to the major energy release site, and simultaneous activity in the higher corona.

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE PAGES

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit; ...

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials and in situ and operando diffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, overmore » a continuous range of diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. In addition, the design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials andin situandoperandodiffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, over a continuous range ofmore » diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. The design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less

Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

DOE PAGES

Miaja-Avila, L.; O'Neil, G. C.; Uhlig, J.; ...

2015-03-02

We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ~10 6 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >10 7 laser pulses, wemore » also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.« less

X-ray compass for determining device orientation

DOEpatents

Da Silva, Luiz B.; Matthews, Dennis L.; Fitch, Joseph P.; Everett, Matthew J.; Colston, Billy W.; Stone, Gary F.

1999-01-01

An apparatus and method for determining the orientation of a device with respect to an x-ray source. In one embodiment, the present invention is coupled to a medical device in order to determine the rotational orientation of the medical device with respect to the x-ray source. In such an embodiment, the present invention is comprised of a scintillator portion which is adapted to emit photons upon the absorption of x-rays emitted from the x-ray source. An x-ray blocking portion is coupled to the scintillator portion. The x-ray blocking portion is disposed so as to vary the quantity of x-rays which penetrate the scintillator portion based upon the particular rotational orientation of the medical device with respect to the x-ray source. A photon transport mechanism is also coupled to the scintillator portion. The photon transport mechanism is adapted to pass the photons emitted from the scintillator portion to an electronics portion. By analyzing the quantity of the photons, the electronics portion determines the rotational orientation of the medical device with respect to the x-ray source.

X-ray compass for determining device orientation

DOEpatents

Da Silva, L.B.; Matthews, D.L.; Fitch, J.P.; Everett, M.J.; Colston, B.W.; Stone, G.F.

1999-06-15

An apparatus and method for determining the orientation of a device with respect to an x-ray source are disclosed. In one embodiment, the present invention is coupled to a medical device in order to determine the rotational orientation of the medical device with respect to the x-ray source. In such an embodiment, the present invention is comprised of a scintillator portion which is adapted to emit photons upon the absorption of x-rays emitted from the x-ray source. An x-ray blocking portion is coupled to the scintillator portion. The x-ray blocking portion is disposed so as to vary the quantity of x-rays which penetrate the scintillator portion based upon the particular rotational orientation of the medical device with respect to the x-ray source. A photon transport mechanism is also coupled to the scintillator portion. The photon transport mechanism is adapted to pass the photons emitted from the scintillator portion to an electronics portion. By analyzing the quantity of the photons, the electronics portion determines the rotational orientation of the medical device with respect to the x-ray source. 25 figs.

Mission and Objectives for the X-1 Advanced Radiation Source*

NASA Astrophysics Data System (ADS)

Rochau, Gary E.; Ramirez, Juan J.; Raglin, Paul S.

1998-11-01

Sandia National Laboratories PO Box 5800, MS-1178, Albuquerque, NM 87185 The X-1 Advanced Radiation Source represents a next step in providing the U.S. Department of Energy's Stockpile Stewardship Program with the high-energy, large volume, laboratory x-ray source for the Radiation Effects Science and Simulation, Inertial Confinement Fusion, and Weapon Physics Programs. Advances in fast pulsed power technology and in z-pinch hohlraums on Sandia National Laboratories' Z Accelerator provide sufficient basis for pursuing the development of X-1. The X-1 plan follows a strategy based on scaling the 2 MJ x-ray output on Z via a 3-fold increase in z-pinch load current. The large volume (>5 cm3), high temperature (>150 eV), temporally long (>10 ns) hohlraums are unique outside of underground nuclear weapon testing. Analytical scaling arguments and hydrodynamic simulations indicate that these hohlraums at temperatures of 230-300 eV will ignite thermonuclear fuel and drive the reaction to a yield of 200 to 1,200 MJ in the laboratory. Non-ignition sources will provide cold x-ray environments (<15 keV) and high yield fusion burn sources will provide high fidelity warm x-ray environments (15 keV-80 keV). This paper will introduce the X-1 Advanced Radiation Source Facility Project, describe the project mission, objective, and preliminary schedule.

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

NASA Astrophysics Data System (ADS)

Bartzsch, Stefan; Oelfke, Uwe

2017-11-01

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

The BL LAC phenomenon: X-ray observations of transition objects and determination of the x-ray spectrum of a complete sample of flat-spectrum radio sources

NASA Technical Reports Server (NTRS)

Worrall, Diana M.

1994-01-01

This report summarizes the activities related to two ROSAT investigations: (1) x-ray properties of radio galaxies thought to contain BL Lac type nuclei; and (2) x-ray spectra of a complete sample of flat-spectrum radio sources. The following papers describing the research are provided as attachments: Multiple X-ray Emission Components in Low Power Radio Galaxies; New X-ray Results on Radio Galaxies; Analysis Techniques for a Multiwavelength Study of Radio Galaxies; Separation of X-ray Emission Components in Radio Galaxies; X-ray Emission in Powerful Radio Galaxies and Quasars; Extended and Compact X-ray Emission in Powerful Radio Galaxies; and X-ray Spectra of a Complete Sample of Extragalactic Core-dominated Radio Sources.

Towards shot-noise limited diffraction experiments with table-top femtosecond hard x-ray sources.

PubMed

Holtz, Marcel; Hauf, Christoph; Weisshaupt, Jannick; Salvador, Antonio-Andres Hernandez; Woerner, Michael; Elsaesser, Thomas

2017-09-01

Table-top laser-driven hard x-ray sources with kilohertz repetition rates are an attractive alternative to large-scale accelerator-based systems and have found widespread applications in x-ray studies of ultrafast structural dynamics. Hard x-ray pulses of 100 fs duration have been generated at the Cu K α wavelength with a photon flux of up to 10 9 photons per pulse into the full solid angle, perfectly synchronized to the sub-100-fs optical pulses from the driving laser system. Based on spontaneous x-ray emission, such sources display a particular noise behavior which impacts the sensitivity of x-ray diffraction experiments. We present a detailed analysis of the photon statistics and temporal fluctuations of the x-ray flux, together with experimental strategies to optimize the sensitivity of optical pump/x-ray probe experiments. We demonstrate measurements close to the shot-noise limit of the x-ray source.

Towards shot-noise limited diffraction experiments with table-top femtosecond hard x-ray sources

PubMed Central

Holtz, Marcel; Hauf, Christoph; Weisshaupt, Jannick; Salvador, Antonio-Andres Hernandez; Woerner, Michael; Elsaesser, Thomas

2017-01-01

Table-top laser-driven hard x-ray sources with kilohertz repetition rates are an attractive alternative to large-scale accelerator-based systems and have found widespread applications in x-ray studies of ultrafast structural dynamics. Hard x-ray pulses of 100 fs duration have been generated at the Cu Kα wavelength with a photon flux of up to 109 photons per pulse into the full solid angle, perfectly synchronized to the sub-100-fs optical pulses from the driving laser system. Based on spontaneous x-ray emission, such sources display a particular noise behavior which impacts the sensitivity of x-ray diffraction experiments. We present a detailed analysis of the photon statistics and temporal fluctuations of the x-ray flux, together with experimental strategies to optimize the sensitivity of optical pump/x-ray probe experiments. We demonstrate measurements close to the shot-noise limit of the x-ray source. PMID:28795079

An X-ray fluorescence spectrometer and its applications in materials studies

NASA Technical Reports Server (NTRS)

Singh, J. J.; Han, K. S.

1977-01-01

An X-ray fluorescence system based on a Co(57) gamma-ray source has been developed. The system was used to calculate the atomic percentages of iron implanted in titanium targets. Measured intensities of Fe (k-alpha + k-beta) and Ti (k-alpha + k-beta) X-rays from the Fe-Ti targets are in good agreement with the calculated values based on photoelectric cross sections of Ti and Fe for the Co(57) gamma rays.

Overview of Mono-Energetic Gamma-Ray Sources and Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartemann, Fred; /LLNL, Livermore; Albert, Felicie

2012-06-25

Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable gamma-ray light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A precision, tunable Mono-Energetic Gamma-ray (MEGa-ray) source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativistic electron bunches produced by an X-band linac designed in collaboration with SLAC NAL will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energymore » range via Compton scattering. This MEGaray source will be used to excite nuclear resonance fluorescence in various isotopes. Applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented, along with important applications, including nuclear resonance fluorescence.« less

NuSTAR Hard X-Ray Survey of the Galactic Center Region. II. X-Ray Point Sources

NASA Technical Reports Server (NTRS)

Hong, Jaesub; Mori, Kaya; Hailey, Charles J.; Nynka, Melania; Zhang, Shou; Gotthelf, Eric; Fornasini, Francesca M.; Krivonos, Roman; Bauer, Franz; Perez, Kerstin;

Adaptive CT scanning system

DOEpatents

Sampayan, Stephen E.

2016-11-22

Apparatus, systems, and methods that provide an X-ray interrogation system having a plurality of stationary X-ray point sources arranged to substantially encircle an area or space to be interrogated. A plurality of stationary detectors are arranged to substantially encircle the area or space to be interrogated, A controller is adapted to control the stationary X-ray point sources to emit X-rays one at a time, and to control the stationary detectors to detect the X-rays emitted by the stationary X-ray point sources.

Analyzing the Spectra of Accreting X-Ray Pulsars

NASA Astrophysics Data System (ADS)

Wolff, Michael

This proposal seeks funding for the analysis of accretion-powered X-ray pulsar spectra from NASA/ HEASARC archived X-ray data. Spectral modeling of accreting X-ray pulsars can tell us a great deal about the physical conditions in and near high mass X-ray binary systems. Such systems have accretion flows where plasma is initially channeled from an accretion disk by the strong neutron star magnetic field, eventually falling onto the magnetic polar cap of the neutron star compact object. Many of these accreting X-ray pulsars have X-ray spectra that consist of broad power-law continua with superposed cyclotron resonant scattering features indicating magnetic field strengths above 10^12 G. The energies of these cyclotron line features have recently been shown to vary with X-ray luminosity in a number of sources such as Her X-1 and V 0332+53, a phenomenon not well understood. Another recent development is the relatively new analytic model for the spectral continuum formation in accretion-powered pulsar systems developed by Becker & Wolff. In their formalism the accretion flows are assumed to go through radiation- dominated radiative shocks and settle onto the neutron star surface. The radiation field consists of strongly Comptonized bremsstrahlung emission from the entire plasma, Comptonized cyclotron emission from the de-excitations of Landau-excited electrons in the neutron star magnetic field, and Comptonized black-body emission from a thermal mound near the neutron star surface. We seek to develop the data analysis tools to apply this model framework to the X-ray data from a wide set of sources to make progress characterizing the basic accretion properties (e.g., magnetic field strength, plasma temperatures, polar cap size, accretion rate per unit area, dominance of bulk vs. thermal Comptonization) as well as understanding the variations of the cyclotron line energies with X-ray luminosity. The three major goals of our proposed work are as follows: In the first year, we will develop the new software module (essentially a computer code representing the theoretical model) necessary to perform the analysis of accretion-powered pulsar X-ray spectra in the XSPEC spectral analysis environment. Also in this first year we will analyze new Suzaku Cycle 6 Target of Opportunity observations of GX 304-1 and 4U 0115+63, two known cyclotron line sources, that we have recently carried out. In the second year of this study we will apply our new XSPEC spectral continuum module to the archival X-ray observational data from a number of accreting X-ray pulsars from the RXTE/PCA/HEXTE and Suzaku/XIS/HXD instruments to extract basic accretion parameters. Our source list contains eight pulsars, seven of which have observed cyclotron scattering lines. These pulsars span a range in magnetic field strength, luminosity, expected accretion rate, expected polar cap size, and Comptonizing temperature. In the second year of this work we also plan to make our new fully tested XSPEC continuum analysis module available to the Goddard Space Flight Center HEASARC for distribution to the astrophysical research community. The development and analysis tasks proposed here will provide for the first time a physical basis for the analysis and interpretation of data on accreting X-ray pulsar spectra.

Searching for New γ-Ray Blazar Candidates in the Third Palermo BAT Hard X-Ray Catalog with WISE

NASA Astrophysics Data System (ADS)

Maselli, A.; Massaro, F.; Cusumano, G.; D'Abrusco, R.; La Parola, V.; Paggi, A.; Segreto, A.; Smith, Howard A.; Tosti, G.

2013-06-01

We searched for γ-ray blazar candidates among the 382 unidentified hard X-ray sources of the third Palermo BAT Catalog (3PBC) obtained from the analysis of 66 months of Swift Burst Alert Telescope (BAT) survey data and listing 1586 sources. We adopted a recently developed association method based on the peculiar infrared colors that characterize the γ-ray blazars included in the second catalog of active galactic nuclei detected by the Fermi Large Area Telescope. We used this method exploiting the data of the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) to establish correspondences between unidentified 3PBC sources and WISE γ-ray blazar candidates located within the BAT positional uncertainty region at a 99% confidence level. We obtained a preliminary list of candidates for which we analyzed all the available data in the Swift archive to complement the information in the literature and in the radio, infrared, and optical catalogs with the information on their optical-UV and soft X-ray emission. Requiring the presence of radio and soft X-ray counterparts consistent with the infrared positions of the selected WISE sources, as well as a blazar-like radio morphology, we finally obtained a list of 24 γ-ray blazar candidates.

Synchrotron Radiation from Outer Space and the Chandra X-Ray Observatory

NASA Technical Reports Server (NTRS)

Weisskopf, M. C.

2006-01-01

The universe provides numerous extremely interesting astrophysical sources of synchrotron X radiation. The Chandra X-ray Observatory and other X-ray missions provide powerful probes of these and other cosmic X-ray sources. Chandra is the X-ray component of NASA's Great Observatory Program which also includes the Hubble Space telescope, the Spitzer Infrared Telescope Facility, and the now defunct Compton Gamma-Ray Observatory. The Chandra X-Ray Observatory provides the best angular resolution (sub-arcsecond) of any previous, current, or planned (for the foreseeable near future) space-based X-ray instrumentation. We present here a brief overview of the technical capability of this X-Ray observatory and some of the remarkable discoveries involving cosmic synchrotron sources.

Chandra reveals a black hole X-ray binary within the ultraluminous supernova remnant MF 16

NASA Astrophysics Data System (ADS)

Roberts, T. P.; Colbert, E. J. M.

2003-06-01

We present evidence, based on Chandra ACIS-S observations of the nearby spiral galaxy NGC 6946, that the extraordinary X-ray luminosity of the MF 16 supernova remnant actually arises in a black hole X-ray binary. This conclusion is drawn from the point-like nature of the X-ray source, its X-ray spectrum closely resembling the spectrum of other ultraluminous X-ray sources thought to be black hole X-ray binary systems, and the detection of rapid hard X-ray variability from the source. We briefly discuss the nature of the hard X-ray variability, and the origin of the extreme radio and optical luminosity of MF 16 in light of this identification.

Femtosecond laser-electron x-ray source

DOEpatents

Hartemann, Frederic V.; Baldis, Hector A.; Barty, Chris P.; Gibson, David J.; Rupp, Bernhard

2004-04-20

A femtosecond laser-electron X-ray source. A high-brightness relativistic electron injector produces an electron beam pulse train. A system accelerates the electron beam pulse train. The femtosecond laser-electron X-ray source includes a high intra-cavity power, mode-locked laser and an x-ray optics system.

Characterization of X-Ray Diffraction System with a Microfocus X-Ray Source and a Polycapillary Optic

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Marshall, Joy K.; Ciszak, Ewa; Ponomarev, Igor

2000-01-01

We present here an optimized microfocus x-ray source and polycapillary optic system designed for diffraction of small protein crystals. The x-ray beam is formed by a 5.5mm focal length capillary collimator coupled with a 40 micron x-ray source operating at 46Watts. Measurements of the x-ray flux, the divergence and the spectral characteristics of the beam are presented, This optimized system provides a seven fold greater flux than our recently reported configuration [M. Gubarev, et al., J. of Applied Crystallography (2000) 33, in press]. We now make a comparison with a 5kWatts rotating anode generator (Rigaku) coupled with confocal multilayer focusing mirrors (Osmic, CMF12- 38Cu6). The microfocus x-ray source and polycapillary collimator system delivers 60% of the x-ray flux from the rotating anode system. Additional ways to improve our microfocus x-ray system, and thus increase the x-ray flux will be discussed.

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

DOE PAGES

Andersen, Tassie K.; Cook, Seyoung; Benda, Erika; ...

2018-03-08

A portable metalorganic gas delivery system designed and constructed to interface with an existing molecular beam epitaxy chamber at beamline 33-ID-E of the Advanced Photon Source is described. This system offers the ability to perform in situ X-ray measurements of complex oxide growth via hybrid molecular beam epitaxy. The performance of the hybrid molecular beam epitaxy system while delivering metalorganic source materials is described. In conclusion, the high-energy X-ray scattering capabilities of the hybrid molecular beam epitaxy system are demonstrated both on oxide films grown solely from the metalorganic source and ABO 3 oxide perovskites containing elements from both themore » metalorganic source and a traditional effusion cell.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andersen, Tassie K.; Cook, Seyoung; Benda, Erika

A portable metalorganic gas delivery system designed and constructed to interface with an existing molecular beam epitaxy chamber at beamline 33-ID-E of the Advanced Photon Source is described. This system offers the ability to perform in situ X-ray measurements of complex oxide growth via hybrid molecular beam epitaxy. The performance of the hybrid molecular beam epitaxy system while delivering metalorganic source materials is described. In conclusion, the high-energy X-ray scattering capabilities of the hybrid molecular beam epitaxy system are demonstrated both on oxide films grown solely from the metalorganic source and ABO 3 oxide perovskites containing elements from both themore » metalorganic source and a traditional effusion cell.« less

Radio emission from an ultraluminous x-ray source.

PubMed

Kaaret, Philip; Corbel, Stephane; Prestwich, Andrea H; Zezas, Andreas

2003-01-17

The physical nature of ultraluminous x-ray sources is uncertain. Stellar-mass black holes with beamed radiation and intermediate black holes with isotropic radiation are two plausible explanations. We discovered radio emission from an ultraluminous x-ray source in the dwarf irregular galaxy NGC 5408. The x-ray, radio, and optical fluxes as well as the x-ray spectral shape are consistent with beamed relativistic jet emission from an accreting stellar black hole. If confirmed, this would suggest that the ultraluminous x-ray sources may be stellar-mass rather than intermediate-mass black holes. However, interpretation of the source as a jet-producing intermediate-mass black hole cannot be ruled out at this time.

Attosecond light sources in the water window

NASA Astrophysics Data System (ADS)

Ren, Xiaoming; Li, Jie; Yin, Yanchun; Zhao, Kun; Chew, Andrew; Wang, Yang; Hu, Shuyuan; Cheng, Yan; Cunningham, Eric; Wu, Yi; Chini, Michael; Chang, Zenghu

2018-02-01

As a compact and burgeoning alternative to synchrotron radiation and free-electron lasers, high harmonic generation (HHG) has proven its superiority in static and time-resolved extreme ultraviolet spectroscopy for the past two decades and has recently gained many interests and successes in generating soft x-ray emissions covering the biologically important water window spectral region. Unlike synchrotron and free-electron sources, which suffer from relatively long pulse width or large time jitter, soft x-ray sources from HHG could offer attosecond time resolution and be synchronized with their driving field to investigate time-resolved near edge absorption spectroscopy, which could reveal rich structural and dynamical information of the interrogated samples. In this paper, we review recent progresses on generating and characterizing attosecond light sources in the water window region. We show our development of an energetic, two-cycle, carrier-envelope phase stable laser source at 1.7 μm and our achievement in producing a 53 as soft x-ray pulse covering the carbon K-edge in the water window. Such source paves the ways for the next generation x-ray spectroscopy with unprecedented temporal resolution.

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.

A long-term space astrophysics research program: An x-ray perspective of the components and structure of galaxies

NASA Technical Reports Server (NTRS)

Fabbiano, G.

1995-01-01

X-ray studies of galaxies by the Smithsonian Astrophysical Observatory (SAO) and MIT are described. Activities at SAO include ROSAT PSPC x-ray data reduction and analysis pipeline; x-ray sources in nearby Sc galaxies; optical, x-ray, and radio study of ongoing galactic merger; a radio, far infrared, optical, and x-ray study of the Sc galaxy NGC247; and a multiparametric analysis of the Einstein sample of early-type galaxies. Activities at MIT included continued analysis of observations with ROSAT and ASCA, and continued development of new approaches to spectral analysis with ASCA and AXAF. Also, a new method for characterizing structure in galactic clusters was developed and applied to ROSAT images of a large sample of clusters. An appendix contains preprints generated by the research.

Evolution of X-ray astronomy

NASA Technical Reports Server (NTRS)

Rossj, B.

1981-01-01

The evolution of X-ray astronomy up to the launching of the Einstein observatory is presented. The evaluation proceeded through the following major steps: (1) discovery of an extrasolar X-ray source, Sco X-1, orders of magnitude stronger than astronomers believed might exist; (2) identification of a strong X-ray source with the Crab Nebula; (3) identification of Sco X-1 with a faint, peculiar optical object; (4) demonstration that X-ray stars are binary systems, each consisting of a collapsed object accreting matter from an ordinary star; (5) discovery of X-ray bursts; (6) discovery of exceedingly strong X-ray emission from active galaxies, quasars and clusters of galaxies; (7) demonstration that the principal X-ray source is a hot gas filling the space between galaxies.

High energy collimating fine grids for HESP program

NASA Technical Reports Server (NTRS)

Eberhard, Carol D.; Frazier, Edward

1993-01-01

There is a need to develop fine pitch x-ray collimator grids as an enabling technology for planned future missions. The grids consist of an array of thin parallel strips of x-ray absorbing material, such as tungsten, with pitches ranging from 34 microns to 2.036 millimeters. The grids are the key components of a new class of spaceborne instruments known as 'x-ray modulation collimators.' These instruments are the first to produce images of celestial sources in the hard x-ray and gamma-ray spectral regions.

Hard X-Ray Scanning Microscope with Multilayer Laue Lens Nanofocusing Optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nazaretski, Evgeny

Evgeny Nazaretski, a physicist at Brookhaven Lab’s National Synchrotron Light Source II, spearheaded the development of a one-of-a-kind x-ray microscope with novel nanofocusing optics called multilayer Laue lenses.

Spectral studies of cosmic X-ray sources

NASA Astrophysics Data System (ADS)

Blissett, R. J.

1980-01-01

The conventional "indirect" method of reduction and data analysis of spectral data from non-dispersive X-ray detectors, by the fitting of assumed spectral models, is examined. The limitations of this procedure are presented, and alternative schemes are considered in which the derived spectra are not biased to an astrophysical source model. A new method is developed in detail to directly restore incident photon spectra from the detected count histograms. This Spectral Restoration Technique allows an increase in resolution, to a degree dependent on the statistical precision of the data. This is illustrated by numerical simulations. Proportional counter data from Ariel 5 are analysed using this technique. The results obtained for the sources Cas A and the Crab Nebula are consistent with previous analyses and show that increases in resolution of up to a factor three are possible in practice. The source Cyg X-3 is closely examined. Complex spectral variability is found, with the continuum and iron-line emission modulated with the 4.8 hour period of the source. The data suggest multi-component emission in the source. Comparing separate Ariel 5 observations and published data from other experiments, a correlation between the spectral shape and source intensity is evident. The source behaviour is discussed with reference to proposed source models. Data acquired by the low-energy detectors on-board HEAO-1 are analysed using the Spectral Restoration Technique. This treatment explicitly demonstrates the existence of oxygen K-absorption edges in the soft X-ray spectra of the Crab Nebula and Sco X-1. These results are considered with reference to current theories of the interstellar medium. The thesis commences with a review of cosmic X-ray sources and the mechanisms responsible for their spectral signatures, and continues with a discussion of the instruments appropriate for spectral studies in X-ray astronomy.

First Images from HERO: A Hard-X-Ray Focusing Telescope

NASA Technical Reports Server (NTRS)

Ramsey, Brian D.; Alexander, Cheryl D.; Apple, Jeff A.; Benson, Carl M.; Dietz, Kurtis L.; Elsner, Ronald F.; Engelhaupt, Darell E.; Ghosh, Kajal K.; Kolodziejczak, Jeffery J.; ODell, Stephen L.;

Simultaneous CT and SPECT tomography using CZT detectors

DOEpatents

Paulus, Michael J.; Sari-Sarraf, Hamed; Simpson, Michael L.; Britton, Jr., Charles L.

2002-01-01

A method for simultaneous transmission x-ray computed tomography (CT) and single photon emission tomography (SPECT) comprises the steps of: injecting a subject with a tracer compound tagged with a .gamma.-ray emitting nuclide; directing an x-ray source toward the subject; rotating the x-ray source around the subject; emitting x-rays during the rotating step; rotating a cadmium zinc telluride (CZT) two-sided detector on an opposite side of the subject from the source; simultaneously detecting the position and energy of each pulsed x-ray and each emitted .gamma.-ray captured by the CZT detector; recording data for each position and each energy of each the captured x-ray and .gamma.-ray; and, creating CT and SPECT images from the recorded data. The transmitted energy levels of the x-rays lower are biased lower than energy levels of the .gamma.-rays. The x-ray source is operated in a continuous mode. The method can be implemented at ambient temperatures.

CVD-diamond-based position sensitive photoconductive detector for high-flux x-rays and gamma rays.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shu, D.

1999-04-19

A position-sensitive photoconductive detector (PSPCD) using insulating-type CVD diamond as its substrate material has been developed at the Advanced Photon Source (APS). Several different configurations, including a quadrant pattern for a x-ray-transmitting beam position monitor (TBPM) and 1-D and 2-D arrays for PSPCD beam profilers, have been developed. Tests on different PSPCD devices with high-heat-flux undulator white x-ray beam, as well as with gamma-ray beams from {sup 60}Co sources have been done at the APS and National Institute of Standards and Technology (NIST). It was proven that the insulating-type CVD diamond can be used to make a hard x-ray andmore » gamma-ray position-sensitive detector that acts as a solid-state ion chamber. These detectors are based on the photoconductivity principle. A total of eleven of these TBPMs have been installed on the APS front ends for commissioning use. The linear array PSPCD beam profiler has been routinely used for direct measurements of the undulator white beam profile. More tests with hard x-rays and gamma rays are planned for the CVD-diamond 2-D imaging PSPCD. Potential applications include a high-dose-rate beam profiler for fourth-generation synchrotrons radiation facilities, such as free-electron lasers.« less

On two new X-ray sources in the SMC and the high luminosities of the Magellanic X-ray sources

NASA Technical Reports Server (NTRS)

Clark, G.; Doxsey, R.; Li, F.; Jernigan, J. G.; Van Paradijs, J.

1978-01-01

The discovery of two new X-ray sources, SMC X-2 and SMC X-3, in the Small Magellanic Cloud is reported. They have hard spectra, and their luminosities in the energy range 2-11 keV are 1.0 and 0.7 by 10 to the 38th power erg/sq cm per sec, respectively. It is shown that the luminosity distribution of the known Magellanic X-ray sources, which are now nine in number, is shifted toward higher luminosities with respect to that of similar sources in the Galaxy, and that the cause of the shift is probably an underabundance of heavy elements in the material accreted by the X-ray sources.

A deeper look at the X-ray point source population of NGC 4472

NASA Astrophysics Data System (ADS)

Joseph, T. D.; Maccarone, T. J.; Kraft, R. P.; Sivakoff, G. R.

2017-10-01

In this paper we discuss the X-ray point source population of NGC 4472, an elliptical galaxy in the Virgo cluster. We used recent deep Chandra data combined with archival Chandra data to obtain a 380 ks exposure time. We find 238 X-ray point sources within 3.7 arcmin of the galaxy centre, with a completeness flux, FX, 0.5-2 keV = 6.3 × 10-16 erg s-1 cm-2. Most of these sources are expected to be low-mass X-ray binaries. We finding that, using data from a single galaxy which is both complete and has a large number of objects (˜100) below 1038 erg s-1, the X-ray luminosity function is well fitted with a single power-law model. By cross matching our X-ray data with both space based and ground based optical data for NGC 4472, we find that 80 of the 238 sources are in globular clusters. We compare the red and blue globular cluster subpopulations and find red clusters are nearly six times more likely to host an X-ray source than blue clusters. We show that there is evidence that these two subpopulations have significantly different X-ray luminosity distributions. Source catalogues for all X-ray point sources, as well as any corresponding optical data for globular cluster sources, are also presented here.

Instrument and method for X-ray diffraction, fluorescence, and crystal texture analysis without sample preparation

NASA Technical Reports Server (NTRS)

Gendreau, Keith (Inventor); Martins, Jose Vanderlei (Inventor); Arzoumanian, Zaven (Inventor)

2010-01-01

An X-ray diffraction and X-ray fluorescence instrument for analyzing samples having no sample preparation includes a X-ray source configured to output a collimated X-ray beam comprising a continuum spectrum of X-rays to a predetermined coordinate and a photon-counting X-ray imaging spectrometer disposed to receive X-rays output from an unprepared sample disposed at the predetermined coordinate upon exposure of the unprepared sample to the collimated X-ray beam. The X-ray source and the photon-counting X-ray imaging spectrometer are arranged in a reflection geometry relative to the predetermined coordinate.

Multisource inverse-geometry CT. Part I. System concept and development

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Man, Bruno, E-mail: deman@ge.com; Harrison, Dan

Purpose: This paper presents an overview of multisource inverse-geometry computed tomography (IGCT) as well as the development of a gantry-based research prototype system. The development of the distributed x-ray source is covered in a companion paper [V. B. Neculaes et al., “Multisource inverse-geometry CT. Part II. X-ray source design and prototype,” Med. Phys. 43, 4617–4627 (2016)]. While progress updates of this development have been presented at conferences and in journal papers, this paper is the first comprehensive overview of the multisource inverse-geometry CT concept and prototype. The authors also provide a review of all previous IGCT related publications. Methods: Themore » authors designed and implemented a gantry-based 32-source IGCT scanner with 22 cm field-of-view, 16 cm z-coverage, 1 s rotation time, 1.09 × 1.024 mm detector cell size, as low as 0.4 × 0.8 mm focal spot size and 80–140 kVp x-ray source voltage. The system is built using commercially available CT components and a custom made distributed x-ray source. The authors developed dedicated controls, calibrations, and reconstruction algorithms and evaluated the system performance using phantoms and small animals. Results: The authors performed IGCT system experiments and demonstrated tube current up to 125 mA with up to 32 focal spots. The authors measured a spatial resolution of 13 lp/cm at 5% cutoff. The scatter-to-primary ratio is estimated 62% for a 32 cm water phantom at 140 kVp. The authors scanned several phantoms and small animals. The initial images have relatively high noise due to the low x-ray flux levels but minimal artifacts. Conclusions: IGCT has unique benefits in terms of dose-efficiency and cone-beam artifacts, but comes with challenges in terms of scattered radiation and x-ray flux limits. To the authors’ knowledge, their prototype is the first gantry-based IGCT scanner. The authors summarized the design and implementation of the scanner and the authors presented results with phantoms and small animals.« less

Multisource inverse-geometry CT. Part I. System concept and development

PubMed Central

De Man, Bruno; Uribe, Jorge; Baek, Jongduk; Harrison, Dan; Yin, Zhye; Longtin, Randy; Roy, Jaydeep; Waters, Bill; Wilson, Colin; Short, Jonathan; Inzinna, Lou; Reynolds, Joseph; Neculaes, V. Bogdan; Frutschy, Kristopher; Senzig, Bob; Pelc, Norbert

2016-01-01

Purpose: This paper presents an overview of multisource inverse-geometry computed tomography (IGCT) as well as the development of a gantry-based research prototype system. The development of the distributed x-ray source is covered in a companion paper [V. B. Neculaes et al., “Multisource inverse-geometry CT. Part II. X-ray source design and prototype,” Med. Phys. 43, 4617–4627 (2016)]. While progress updates of this development have been presented at conferences and in journal papers, this paper is the first comprehensive overview of the multisource inverse-geometry CT concept and prototype. The authors also provide a review of all previous IGCT related publications. Methods: The authors designed and implemented a gantry-based 32-source IGCT scanner with 22 cm field-of-view, 16 cm z-coverage, 1 s rotation time, 1.09 × 1.024 mm detector cell size, as low as 0.4 × 0.8 mm focal spot size and 80–140 kVp x-ray source voltage. The system is built using commercially available CT components and a custom made distributed x-ray source. The authors developed dedicated controls, calibrations, and reconstruction algorithms and evaluated the system performance using phantoms and small animals. Results: The authors performed IGCT system experiments and demonstrated tube current up to 125 mA with up to 32 focal spots. The authors measured a spatial resolution of 13 lp/cm at 5% cutoff. The scatter-to-primary ratio is estimated 62% for a 32 cm water phantom at 140 kVp. The authors scanned several phantoms and small animals. The initial images have relatively high noise due to the low x-ray flux levels but minimal artifacts. Conclusions: IGCT has unique benefits in terms of dose-efficiency and cone-beam artifacts, but comes with challenges in terms of scattered radiation and x-ray flux limits. To the authors’ knowledge, their prototype is the first gantry-based IGCT scanner. The authors summarized the design and implementation of the scanner and the authors presented results with phantoms and small animals. PMID:27487877

Advanced Compton scattering light source R&D at LLNL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Albert, F; Anderson, S G; Anderson, G

2010-02-16

We report the design and current status of a monoenergetic laser-based Compton scattering 0.5-2.5 MeV {gamma}-ray source. Previous nuclear resonance fluorescence results and future linac and laser developments for the source are presented. At MeV photon energies relevant for nuclear processes, Compton scattering light sources are attractive because of their relative compactness and improved brightness above 100 keV, compared to typical 4th generation synchrotrons. Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable Mono-Energetic Gamma-Ray (MEGa-Ray) light sources based on Compton scattering between a high-brightness, relativistic electron beam and a highmore » intensity laser pulse produced via chirped-pulse amplification (CPA). A new precision, tunable gamma-ray source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativistic electron bunches produced by an X-band linac designed in collaboration with SLAC will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. Based on the success of the previous Thomson-Radiated Extreme X-rays (T-REX) Compton scattering source at LLNL, the source will be used to excite nuclear resonance fluorescence lines in various isotopes; applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. After a brief presentation of successful nuclear resonance fluorescence (NRF) experiments done with T-REX, the new source design, key parameters, and current status are presented.« less

Development and Applications Of Photosensitive Device Systems To Studies Of Biological And Organic Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gruner, Sol

2012-01-20

The primary focus of the grant is the development of new x-ray detectors for biological and materials work at synchrotron sources, especially Pixel Array Detectors (PADs), and the training of students via research applications to problems in biophysics and materials science using novel x-ray methods. This Final Progress Report provides a high-level overview of the most important accomplishments. These major areas of accomplishment include: (1) Development and application of x-ray Pixel Array Detectors; (2) Development and application of methods of high pressure x-ray crystallography as applied to proteins; (3) Studies on the synthesis and structure of novel mesophase materials derivedmore » from block co-polymers.« less

Discovery and Characterization of Gravitationally Lensed X-ray Sources in the CLASH Sample

NASA Astrophysics Data System (ADS)

Pasha, Imad; Van Weeren, Reinout J.; Santos, Felipe A.

2017-01-01

We present the discovery of ~20 gravitationally lensed X-ray sources in the Cluster Lensing And Supernova survey with Hubble (CLASH) survey, a sample of massive clusters of galaxies between z ~ 0.2-0.9 observed with the Hubble Space Telescope (HST). By combining CLASH imaging with Chandra X-ray Observatory observations of the same clusters, we select those sources in the HST images which are gravitationally lensed X-ray sources behind the clusters. Of those discovered sources, we determine various properties including source redshifts and magnifications, as well as performing X-ray spectral fits to determine source fluxes and luminosities. Prior to this study, only four lensed X-ray sources behind clusters have been found, thus to the best of our knowledge, our program is the first to systematically categorize lensed X-ray sources behind galaxy clusters.This work was supported by the SAO REU program, which is funded in part by the National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant no. 1262851, and by the Smithsonian Institution.

MOXE: An X-ray all-sky monitor for Soviet Spectrum-X-Gamma Mission

NASA Technical Reports Server (NTRS)

Priedhorsky, W.; Fenimore, E. E.; Moss, C. E.; Kelley, R. L.; Holt, S. S.

1989-01-01

A Monitoring Monitoring X-Ray Equipment (MOXE) is being developed for the Soviet Spectrum-X-Gamma Mission. MOXE is an X-ray all-sky monitor based on array of pinhole cameras, to be provided via a collaboration between Goddard Space Flight Center and Los Alamos National Laboratory. The objectives are to alert other observers on Spectrum-X-Gamma and other platforms of interesting transient activity, and to synoptically monitor the X-ray sky and study long-term changes in X-ray binaries. MOXE will be sensitive to sources as faint as 2 milliCrab (5 sigma) in 1 day, and cover the 2 to 20 KeV band.

APPARATUS FOR PRODUCING SHADOWGRAPHS

DOEpatents

Wilson, R.R.

1959-08-11

An apparatus is presented for obtaining shadowgraphs or radiographs of an object exposed to x rays or the like. The device includes the combination of a cloud chamber having the interior illuminated and a portion thereof transparent to light rays and x'rays, a controlled source of x rays spaced therefrom, photographic recording disposed laterally of the linear path intermediate the source and the chamber portion in oblique angularity in aspect to the path. The object to be studied is disposed intermediate the x-ray source and chamber in the linear path to provide an x-ray transmission barrier therebetween. The shadowgraph is produced in the cloud chamber in response to initiation of the x- ray source and recorded photographically.

Observations of low-luminosity X-ray sources in Vela-Puppis

NASA Technical Reports Server (NTRS)

Pravdo, S. H.; Becker, R. H.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.; Swank, J. H.

1978-01-01

Results are presented for a study of the X-ray emission from a small portion of the galactic plane near galactic longitude 260 deg. This region contains at least six low-luminosity X-ray sources within about 10 deg of PSR 0833-45, which is near the center of the Gum nebula. The X-ray source 4U 0833-45, associated with the Vela pulsar, is observed at twice its 4U catalog intensity. The lack of X-ray pulsations at the pulsar period (greater than 99% nonpulsed), the nonthermal power-law spectrum, and models of the X-ray source distribution in this region suggest that a large fraction of the X-rays come from an extended source about 1 deg of arc in radius. The observation of a high-temperature (effective temperature at least 100 million K) spectrum in a field of view containing only Puppis A among known sources has led to the discovery of new OSO 8 source, OS 0752-39. Other spectra from this region are discussed.

Identification of Hard X-ray Sources in Galactic Globular Clusters: Simbol-X Simulations

NASA Astrophysics Data System (ADS)

Servillat, M.

2009-05-01

Globular clusters harbour an excess of X-ray sources compared to the number of X-ray sources in the Galactic plane. It has been proposed that many of these X-ray sources are cataclysmic variables that have an intermediate magnetic field, i.e. intermediate polars, which remains to be confirmed and understood. We present here several methods to identify intermediate polars in globular clusters from multiwavelength analysis. First, we report on XMM-Newton, Chandra and HST observations of the very dense Galactic globular cluster NGC 2808. By comparing UV and X-ray properties of the cataclysmic variable candidates, the fraction of intermediate polars in this cluster can be estimated. We also present the optical spectra of two cataclysmic variables in the globular cluster M 22. The HeII (4868 Å) emission line in these spectra could be related to the presence of a magnetic field in these objects. Simulations of Simbol-X observations indicate that the angular resolution is sufficient to study X-ray sources in the core of close, less dense globular clusters, such as M 22. The sensitivity of Simbol-X in an extended energy band up to 80 keV will allow us to discriminate between hard X-ray sources (such as magnetic cataclysmic variables) and soft X-ray sources (such as chromospherically active binaries).

High brightness x ray source for directed energy and holographic imaging applications, phase 2

NASA Astrophysics Data System (ADS)

McPherson, Armon; Rhodes, Charles K.

1992-03-01

Advances in x-ray imaging technology and x-ray sources are such that a new technology can be brought to commercialization enabling the three-dimensional (3-D) microvisualization of hydrated biological specimens. The Company is engaged in a program whose main goal is the development of a new technology for direct three dimensional (3-D) x-ray holographic imaging. It is believed that this technology will have a wide range of important applications in the defense, medical, and scientific sectors. For example, in the medical area, it is expected that biomedical science will constitute a very active and substantial market, because the application of physical technologies for the direct visualization of biological entities has had a long and extremely fruitful history.

Studies on the effect of the axial magnetic field on the x-ray bremsstrahlung in a 2.45 GHz permanent magnet microwave ion source.

PubMed

Kumar, Narender; Rodrigues, G; Lakshmy, P S; Baskaran, R; Mathur, Y; Ahuja, R; Kanjilal, D

2014-02-01

A compact microwave ion source has been designed and developed for operation at a frequency of 2.45 GHz. The axial magnetic field is based on two permanent magnet rings, operating in the "off-resonance" mode and is tunable by moving the permanent magnets. In order to understand the electron energy distribution function, x-ray bremsstrahlung has been measured in the axial direction. Simulation studies on the x-ray bremsstrahlung have been carried out to compare with the experimental results. The effect of the axial magnetic field with respect to the microwave launching position and the position of the extraction electrode on the x-ray bremsstrahlung have been studied.

Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maddox, B. R., E-mail: maddox3@llnl.gov; Akin, M. C., E-mail: akin1@llnl.gov; Teruya, A.

2016-08-15

Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from themore » sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10{sup 7} molybdenum Kα photons.« less

Broad-Band Measurements of Cen X-3 With XTE and CGRO

NASA Technical Reports Server (NTRS)

Vestrand, W. Thomas

1999-01-01

Centaurus X-3 has played a key role in the development of our understanding of galactic x-ray binary sources. Timing analysis of the UHURU x-ray observations for the luminous Cen X-3 source (L approximately 10(exp 38) erg/s) revealed the first evidence for coherent x-ray pulsations from an object in a binary system (Giaconni 1971; Schreier 1972). It was quickly understood that the luminous pulsed x-ray emission could be generated by the accretion of matter from a companion star onto a rotating neutron star and led to the adoption of binary star models as the fundamental model for galactic x-ray sources (e.g. Pringle and Rees 1972; Lamb 1973). Based on modeling and refined observations since the original measurements, we now believe that Cen X-3 is a high mass x-ray binary system that contains a disk-fed pulsar with a period of 4.84 seconds that is in a 2.087 day orbit around an O-star companion. Since the pulsar discovery, its period has been intermittently monitored and those studies show a long term spin-up of the pulsar punctuated by short intervals of spin-down (e.g. Finger 1994). The implied torques are thought to originate from the interaction of an accretion disk with the magnetic field of a neutron star (Ghosh and Lamb 1979).

CHANDRA ACIS SURVEY OF X-RAY POINT SOURCES IN NEARBY GALAXIES. II. X-RAY LUMINOSITY FUNCTIONS AND ULTRALUMINOUS X-RAY SOURCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Song; Qiu, Yanli; Liu, Jifeng

Based on the recently completed Chandra /ACIS survey of X-ray point sources in nearby galaxies, we study the X-ray luminosity functions (XLFs) for X-ray point sources in different types of galaxies and the statistical properties of ultraluminous X-ray sources (ULXs). Uniform procedures are developed to compute the detection threshold, to estimate the foreground/background contamination, and to calculate the XLFs for individual galaxies and groups of galaxies, resulting in an XLF library of 343 galaxies of different types. With the large number of surveyed galaxies, we have studied the XLFs and ULX properties across different host galaxy types, and confirm withmore » good statistics that the XLF slope flattens from lenticular ( α ∼ 1.50 ± 0.07) to elliptical (∼1.21 ± 0.02), to spirals (∼0.80 ± 0.02), to peculiars (∼0.55 ± 0.30), and to irregulars (∼0.26 ± 0.10). The XLF break dividing the neutron star and black hole binaries is also confirmed, albeit at quite different break luminosities for different types of galaxies. A radial dependency is found for ellipticals, with a flatter XLF slope for sources located between D {sub 25} and 2 D {sub 25}, suggesting the XLF slopes in the outer region of early-type galaxies are dominated by low-mass X-ray binaries in globular clusters. This study shows that the ULX rate in early-type galaxies is 0.24 ± 0.05 ULXs per surveyed galaxy, on a 5 σ confidence level. The XLF for ULXs in late-type galaxies extends smoothly until it drops abruptly around 4 × 10{sup 40} erg s{sup −1}, and this break may suggest a mild boundary between the stellar black hole population possibly including 30 M {sub ⊙} black holes with super-Eddington radiation and intermediate mass black holes.« less

X-band RF gun and linac for medical Compton scattering X-ray source

NASA Astrophysics Data System (ADS)

Dobashi, Katsuhito; Uesaka, Mitsuru; Fukasawa, Atsushi; Sakamoto, Fumito; Ebina, Futaro; Ogino, Haruyuki; Urakawa, Junji; Higo, Toshiyasu; Akemoto, Mitsuo; Hayano, Hitoshi; Nakagawa, Keiichi

2004-12-01

Compton scattering hard X-ray source for 10-80 keV are under construction using the X-band (11.424 GHz) electron linear accelerator and YAG laser at Nuclear Engineering Research laboratory, University of Tokyo. This work is a part of the national project on the development of advanced compact medical accelerators in Japan. National Institute for Radiological Science is the host institute and U.Tokyo and KEK are working for the X-ray source. Main advantage is to produce tunable monochromatic hard (10-80 keV) X-rays with the intensities of 108-1010 photons/s (at several stages) and the table-top size. Second important aspect is to reduce noise radiation at a beam dump by adopting the deceleration of electrons after the Compton scattering. This realizes one beamline of a 3rd generation SR source at small facilities without heavy shielding. The final goal is that the linac and laser are installed on the moving gantry. We have designed the X-band (11.424 GHz) traveling-wave-type linac for the purpose. Numerical consideration by CAIN code and luminosity calculation are performed to estimate the X-ray yield. X-band thermionic-cathode RF-gun and RDS(Round Detuned Structure)-type X-band accelerating structure are applied to generate 50 MeV electron beam with 20 pC microbunches (104) for 1 microsecond RF macro-pulse. The X-ray yield by the electron beam and Q-switch Nd:YAG laser of 2 J/10 ns is 107 photons/RF-pulse (108 photons/sec at 10 pps). We design to adopt a technique of laser circulation to increase the X-ray yield up to 109 photons/pulse (1010 photons/s). 50 MW X-band klystron and compact modulator have been constructed and now under tuning. The construction of the whole system has started. X-ray generation and medical application will be performed in the early next year.

Recent high energy gamma-ray results from SAS-2

NASA Technical Reports Server (NTRS)

Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Bignami, G. F.; Ogelman, H. B.; Ozel, M. E.; Tumer, T.; Lamb, R. C.

1977-01-01

Recent developments in gamma-ray astronomy due to the results from SAS-2 have focused on two areas. First, the emission from the plane of the Galaxy is the dominant feature in the gamma-ray sky. The galactic latitude and longitude distributions are consistent with the concept that the high-energy radiation originates from cosmic rays interacting with interstellar matter, and the measurements support a galactic origin for cosmic rays. Second, searches of the SAS-2 data for emission from localized sources have shown three strong discrete gamma-ray sources: the Crab nebula and PSR 0531 + 21, the Vela supernova remnant and PSR 0833-45, and a source near galactic coordinates 193 deg longitude, +3 deg latitude, which does not appear to be associated with other known celestial objects. Evidence has also been found for pulsed gamma-ray emission from two other radio pulsars, PSR 1818-04 and PSR 1747-46. A localized source near longitudes 76-80 deg may be associated with the X-ray source Cyg X-3.

Analysis of field of view limited by a multi-line X-ray source and its improvement for grating interferometry.

PubMed

Du, Yang; Huang, Jianheng; Lin, Danying; Niu, Hanben

2012-08-01

X-ray phase-contrast imaging based on grating interferometry is a technique with the potential to provide absorption, differential phase contrast, and dark-field signals simultaneously. The multi-line X-ray source used recently in grating interferometry has the advantage of high-energy X-rays for imaging of thick samples for most clinical and industrial investigations. However, it has a drawback of limited field of view (FOV), because of the axial extension of the X-ray emission area. In this paper, we analyze the effects of axial extension of the multi-line X-ray source on the FOV and its improvement in terms of Fresnel diffraction theory. Computer simulation results show that the FOV limitation can be overcome by use of an alternative X-ray tube with a specially designed multi-step anode. The FOV of this newly designed X-ray source can be approximately four times larger than that of the multi-line X-ray source in the same emission area. This might be beneficial for the applications of X-ray phase contrast imaging in materials science, biology, medicine, and industry.

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

PubMed

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

2011-10-01

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

Final Report on DTRA Basic Research Project #BRCALL08-Per3-C-2-0006 "High-Z Non-Equilibrium Physics and Bright X-ray Sources with New Laser Targets"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colvin, Jeffrey D.

This project had two major goals. Final Goal: obtain spectrally resolved, absolutely calibrated x-ray emission data from uniquely uniform mm-scale near-critical-density high-Z plasmas not in local thermodynamic equilibrium (LTE) to benchmark modern detailed atomic physics models. Scientific significance: advance understanding of non-LTE atomic physics. Intermediate Goal: develop new nano-fabrication techniques to make suitable laser targets that form the required highly uniform non-LTE plasmas when illuminated by high-intensity laser light. Scientific significance: advance understanding of nano-science. The new knowledge will allow us to make x-ray sources that are bright at the photon energies of most interest for testing radiation hardening technologies,more » the spectral energy range where current x-ray sources are weak. All project goals were met.« less

Capsule implosions for continuum x-ray backlighting of opacity samples at the National Ignition Facility

DOE PAGES

Opachich, Y. P.; Heeter, R. F.; Barrios, M. A.; ...

2017-06-08

Direct drive implosions of plastic capsules have been performed at the National Ignition Facility to provide a broad-spectrum (500–2000 eV) X-ray continuum source for X-ray transmission spectroscopy. The source was developed for the high-temperature plasma opacity experimental platform. Initial experiments using 2.0 mm diameter polyalpha-methyl styrene capsules with ~20 μm thickness have been performed. X-ray yields of up to ~1 kJ/sr have been measured using the Dante multichannel diode array. The backlighter source size was measured to be ~100 μm FWHM, with ~350 ps pulse duration during the peak emission stage. Lastly, these results are used to simulate transmission spectramore » for a hypothetical iron opacity sample at 150 eV, enabling the derivation of photometrics requirements for future opacity experiments.« less

Capsule implosions for continuum x-ray backlighting of opacity samples at the National Ignition Facility.

PubMed

Opachich, Y P; Heeter, R F; Barrios, M A; Garcia, E M; Craxton, R S; King, J A; Liedahl, D A; McKenty, P W; Schneider, M B; May, M J; Zhang, R; Ross, P W; Kline, J L; Moore, A S; Weaver, J L; Flippo, K A; Perry, T S

2017-06-01

Direct drive implosions of plastic capsules have been performed at the National Ignition Facility to provide a broad-spectrum (500-2000 eV) X-ray continuum source for X-ray transmission spectroscopy. The source was developed for the high-temperature plasma opacity experimental platform. Initial experiments using 2.0 mm diameter polyalpha-methyl styrene capsules with ∼20  μ m thickness have been performed. X-ray yields of up to ∼1 kJ/sr have been measured using the Dante multichannel diode array. The backlighter source size was measured to be ∼100  μ m FWHM, with ∼350 ps pulse duration during the peak emission stage. Results are used to simulate transmission spectra for a hypothetical iron opacity sample at 150 eV, enabling the derivation of photometrics requirements for future opacity experiments.

Main functions, recent updates, and applications of Synchrotron Radiation Workshop code

NASA Astrophysics Data System (ADS)

Chubar, Oleg; Rakitin, Maksim; Chen-Wiegart, Yu-Chen Karen; Chu, Yong S.; Fluerasu, Andrei; Hidas, Dean; Wiegart, Lutz

2017-08-01

The paper presents an overview of the main functions and new application examples of the "Synchrotron Radiation Workshop" (SRW) code. SRW supports high-accuracy calculations of different types of synchrotron radiation, and simulations of propagation of fully-coherent radiation wavefronts, partially-coherent radiation from a finite-emittance electron beam of a storage ring source, and time-/frequency-dependent radiation pulses of a free-electron laser, through X-ray optical elements of a beamline. An extended library of physical-optics "propagators" for different types of reflective, refractive and diffractive X-ray optics with its typical imperfections, implemented in SRW, enable simulation of practically any X-ray beamline in a modern light source facility. The high accuracy of calculation methods used in SRW allows for multiple applications of this code, not only in the area of development of instruments and beamlines for new light source facilities, but also in areas such as electron beam diagnostics, commissioning and performance benchmarking of insertion devices and individual X-ray optical elements of beamlines. Applications of SRW in these areas, facilitating development and advanced commissioning of beamlines at the National Synchrotron Light Source II (NSLS-II), are described.

Back-bombardment compensation in microwave thermionic electron guns

NASA Astrophysics Data System (ADS)

Kowalczyk, Jeremy M. D.; Madey, John M. J.

2014-12-01

The development of capable, reliable, and cost-effective compact electron beam sources remains a long-standing objective of the efforts to develop the accelerator systems needed for on-site research and industrial applications ranging from electron beam welding to high performance x-ray and gamma ray light sources for element-resolved microanalysis and national security. The need in these applications for simplicity, reliability, and low cost has emphasized solutions compatible with the use of the long established and commercially available pulsed microwave rf sources and L-, S- or X-band linear accelerators. Thermionic microwave electron guns have proven to be one successful approach to the development of the electron sources for these systems providing high macropulse average current beams with picosecond pulse lengths and good emittance out to macropulse lengths of 4-5 microseconds. But longer macropulse lengths are now needed for use in inverse-Compton x-ray sources and other emerging applications. We describe in this paper our approach to extending the usable macropulse current and pulse length of these guns through the use of thermal diffusion to compensate for the increase in cathode surface temperature due to back-bombardment.

X-ray bursters and the X-ray sources of the galactic bulge

NASA Technical Reports Server (NTRS)

Lewin, W. H. G.; Joss, P. C.

1980-01-01

Type 1 X-ray bursts, optical, infrared, and radio properties of the galactic bulge sources, are discussed. It was proven that these burst sources are neutron stars in low mass, close binary stellar systems. Several burst sources are found in globular clusters with high central densities. Optical type 1 X-ray bursts were observed from three sources. Type 2 X-ray bursts, observed from the Rapid Burster, are due to an accretion instability which converts gravitational potential energy into heat and radiation, which makes them of a fundamentally different nature from Type 1 bursts.

Radial Distribution of X-Ray Point Sources Near the Galactic Center

NASA Astrophysics Data System (ADS)

Hong, Jae Sub; van den Berg, Maureen; Grindlay, Jonathan E.; Laycock, Silas

2009-11-01

We present the log N-log S and spatial distributions of X-ray point sources in seven Galactic bulge (GB) fields within 4° from the Galactic center (GC). We compare the properties of 1159 X-ray point sources discovered in our deep (100 ks) Chandra observations of three low extinction Window fields near the GC with the X-ray sources in the other GB fields centered around Sgr B2, Sgr C, the Arches Cluster, and Sgr A* using Chandra archival data. To reduce the systematic errors induced by the uncertain X-ray spectra of the sources coupled with field-and-distance-dependent extinction, we classify the X-ray sources using quantile analysis and estimate their fluxes accordingly. The result indicates that the GB X-ray population is highly concentrated at the center, more heavily than the stellar distribution models. It extends out to more than 1fdg4 from the GC, and the projected density follows an empirical radial relation inversely proportional to the offset from the GC. We also compare the total X-ray and infrared surface brightness using the Chandra and Spitzer observations of the regions. The radial distribution of the total infrared surface brightness from the 3.6 band μm images appears to resemble the radial distribution of the X-ray point sources better than that predicted by the stellar distribution models. Assuming a simple power-law model for the X-ray spectra, the closer to the GC the intrinsically harder the X-ray spectra appear, but adding an iron emission line at 6.7 keV in the model allows the spectra of the GB X-ray sources to be largely consistent across the region. This implies that the majority of these GB X-ray sources can be of the same or similar type. Their X-ray luminosity and spectral properties support the idea that the most likely candidate is magnetic cataclysmic variables (CVs), primarily intermediate polars (IPs). Their observed number density is also consistent with the majority being IPs, provided the relative CV to star density in the GB is not smaller than the value in the local solar neighborhood.

Symbiotic Stars in X-rays

NASA Technical Reports Server (NTRS)

Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.

2014-01-01

Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. Swift/XRT detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the alpha/beta/gamma classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new sigma classification for sources with hard X-ray emission from the innermost accretion region. Since we have identified the elusive accretion component in the emission from a sample of symbiotic stars, our results have implications for the understanding of wind-fed mass transfer in wide binaries, and the accretion rate in one class of candidate progenitors of type Ia supernovae.

Optical and X-ray early follow-up of ANTARES neutrino alerts

NASA Astrophysics Data System (ADS)

Adrián-Martínez, S.; Ageron, M.; Albert, A.; Samarai, I. Al; André, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bogazzi, C.; Bormuth, R.; Bou-Cabo, M.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Dekeyser, I.; Deschamps, A.; De Bonis, G.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Dumas, A.; Eberl, T.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fermani, P.; Folger, F.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Gracia-Ruiz, R.; Graf, K.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Herrero, A.; Hößl, J.; Hofestädt, J.; Hugon, C.; James, C. W.; de Jong, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kooijman, P.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lambard, G.; Lattuada, D.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martínez-Mora, J. A.; Martini, S.; Mathieu, A.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Neff, M.; Nezri, E.; Păvălaš, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Richter, R.; Roensch, K.; Rostovtsev, A.; Saldaña, M.; Samtleben, D. F. E.; Sanguineti, M.; Sapienza, P.; Schmid, J.; Schnabel, J.; Schulte, S.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Sánchez-Losa, A.; Taiuti, M.; Tamburini, C.; Trovato, A.; Tselengidou, M.; Tönnis, C.; Turpin, D.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Vecchi, M.; Visser, E.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.; Klotz, A.; Boer, M.; Le Van Suu, A.; Akerlof, C.; Zheng, W.; Evans, P.; Gehrels, N.; Kennea, J.; Osborne, J. P.; Coward, D. M.

2016-02-01

High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. Even with the recent detection of extraterrestrial high-energy neutrinos by the IceCube experiment, no astrophysical neutrino source has yet been discovered. Transient sources, such as gamma-ray bursts, core-collapse supernovae, or active galactic nuclei are promising candidates. Multi-messenger programs offer a unique opportunity to detect these transient sources. By combining the information provided by the ANTARES neutrino telescope with information coming from other observatories, the probability of detecting a source is enhanced, allowing the possibility of identifying a neutrino progenitor from a single detected event. A method based on optical and X-ray follow-ups of high-energy neutrino alerts has been developed within the ANTARES collaboration. This method does not require any assumptions on the relation between neutrino and photon spectra other than time-correlation. This program, denoted as TAToO, triggers a network of robotic optical telescopes (TAROT and ROTSE) and the Swift-XRT with a delay of only a few seconds after a neutrino detection, and is therefore well-suited to search for fast transient sources. To identify an optical or X-ray counterpart to a neutrino signal, the images provided by the follow-up observations are analysed with dedicated pipelines. A total of 42 alerts with optical and 7 alerts with X-ray images taken with a maximum delay of 24 hours after the neutrino trigger have been analysed. No optical or X-ray counterparts associated to the neutrino triggers have been found, and upper limits on transient source magnitudes have been derived. The probability to reject the gamma-ray burst origin hypothesis has been computed for each alert.

Optical and X-ray early follow-up of ANTARES neutrino alerts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adrián-Martínez, S.; Ardid, M.; Ageron, M.

High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. Even with the recent detection of extraterrestrial high-energy neutrinos by the IceCube experiment, no astrophysical neutrino source has yet been discovered. Transient sources, such as gamma-ray bursts, core-collapse supernovae, or active galactic nuclei are promising candidates. Multi-messenger programs offer a unique opportunity to detect these transient sources. By combining the information provided by the ANTARES neutrino telescope with information coming from other observatories, the probability of detecting a source is enhanced, allowing the possibility of identifying a neutrino progenitor from amore » single detected event. A method based on optical and X-ray follow-ups of high-energy neutrino alerts has been developed within the ANTARES collaboration. This method does not require any assumptions on the relation between neutrino and photon spectra other than time-correlation. This program, denoted as TAToO, triggers a network of robotic optical telescopes (TAROT and ROTSE) and the Swift-XRT with a delay of only a few seconds after a neutrino detection, and is therefore well-suited to search for fast transient sources. To identify an optical or X-ray counterpart to a neutrino signal, the images provided by the follow-up observations are analysed with dedicated pipelines. A total of 42 alerts with optical and 7 alerts with X-ray images taken with a maximum delay of 24 hours after the neutrino trigger have been analysed. No optical or X-ray counterparts associated to the neutrino triggers have been found, and upper limits on transient source magnitudes have been derived. The probability to reject the gamma-ray burst origin hypothesis has been computed for each alert.« less

SU-D-207-03: Development of 4D-CBCT Imaging System with Dual Source KV X-Ray Tubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakamura, M; Ishihara, Y; Matsuo, Y

Purpose: The purposes of this work are to develop 4D-CBCT imaging system with orthogonal dual source kV X-ray tubes, and to determine the imaging doses from 4D-CBCT scans. Methods: Dual source kV X-ray tubes were used for the 4D-CBCT imaging. The maximum CBCT field of view was 200 mm in diameter and 150 mm in length, and the imaging parameters were 110 kV, 160 mA and 5 ms. The rotational angle was 105°, the rotational speed of the gantry was 1.5°/s, the gantry rotation time was 70 s, and the image acquisition interval was 0.3°. The observed amplitude of infraredmore » marker motion during respiration was used to sort each image into eight respiratory phase bins. The EGSnrc/BEAMnrc and EGSnrc/DOSXYZnrc packages were used to simulate kV X-ray dose distributions of 4D-CBCT imaging. The kV X-ray dose distributions were calculated for 9 lung cancer patients based on the planning CT images with dose calculation grid size of 2.5 x 2.5 x 2.5 mm. The dose covering a 2-cc volume of skin (D2cc), defined as the inner 5 mm of the skin surface with the exception of bone structure, was assessed. Results: A moving object was well identified on 4D-CBCT images in a phantom study. Given a gantry rotational angle of 105° and the configuration of kV X-ray imaging subsystems, both kV X-ray fields overlapped at a part of skin surface. The D2cc for the 4D-CBCT scans was in the range 73.8–105.4 mGy. Linear correlation coefficient between the 1000 minus averaged SSD during CBCT scanning and D2cc was −0.65 (with a slope of −0.17) for the 4D-CBCT scans. Conclusion: We have developed 4D-CBCT imaging system with dual source kV X-ray tubes. The total imaging dose with 4D-CBCT scans was up to 105.4 mGy.« less

Hard X-Ray Scanning Microscope with Multilayer Laue Lens Nanofocusing Optics

ScienceCinema

Nazaretski, Evgeny

2018-06-13

Evgeny Nazaretski, a physicist at Brookhaven Lab’s National Synchrotron Light Source II, spearheaded the development of a one-of-a-kind x-ray microscope with novel nanofocusing optics called multilayer Laue lenses.

OVERVIEW OF MONO-ENERGETIC GAMMA-RAY SOURCES & APPLICATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartemann, F V; Albert, F; Anderson, G G

2010-05-18

Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable gamma-ray light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A precision, tunable Mono-Energetic Gamma-ray (MEGa-ray) source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativistic electron bunches produced by an X-band linac designed in collaboration with SLAC NAL will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energymore » range via Compton scattering. This MEGa-ray source will be used to excite nuclear resonance fluorescence in various isotopes. Applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented, along with important applications, including nuclear resonance fluorescence. In conclusion, we have optimized the design of a high brightness Compton scattering gamma-ray source, specifically designed for NRF applications. Two different parameters sets have been considered: one where the number of photons scattered in a single shot reaches approximately 7.5 x 10{sup 8}, with a focal spot size around 8 {micro}m; in the second set, the spectral brightness is optimized by using a 20 {micro}m spot size, with 0.2% relative bandwidth.« less

Gamma rays, X-rays, and optical light from the cobalt and the neutron star in SN 1987A

NASA Technical Reports Server (NTRS)

Kumagai, Shiomi; Shigeyama, Toshikazu; Nomoto, Ken'ichi; Itoh, Masayuki; Nishimura, Jun

1989-01-01

Recent developments in modeling the X-ray and gamma-ray emission from SN 1987A are discussed by taking into account both the decaying cobalt and the buried neutron star. The light curve and the spectra evolution of X-rays and gamma-rays are well modeled up to day of about 300 if mixing of Co-56 into hydrogen-rich envelope is assumed. However, the 16-28 keV flux observed by Ginga declines very slowly, whereas the spherical mixing model predicts that the flux should have decreased by a large factor at t greater than 300d. It is shown that this problem can be solved if the photoelectric absorption of X-rays is effectively reduced as a result of the formation of chemically inhomogeneous clumps. Based on the adopted hydrodynamical model and the abundance distribution, predictions are offered for future optical, X-ray, and gamma-ray light curves by taking into account other radioactive sources and various types of the central source, e.g., a buried neutron star accreting the reinfalling material or an isolated pulsar.

PLEIADES: High Peak Brightness, Subpicosecond Thomson Hard-X-ray source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuba, J; Anderson, S G; Barty, C J

2003-12-15

The Picosecond Laser-Electron Inter-Action for the Dynamic Evaluation of Structures (PLEIADES) facility, is a unique, novel, tunable (10-200 keV), ultrafast (ps-fs), hard x-ray source that greatly extends the parameter range reached by existing 3rd generation sources, both in terms of x-ray energy range, pulse duration, and peak brightness at high energies. First light was observed at 70 keV early in 2003, and the experimental data agrees with 3D codes developed at LLNL. The x-rays are generated by the interaction of a 50 fs Fourier-transform-limited laser pulse produced by the TW-class FALCON CPA laser and a highly focused, relativistic (20-100 MeV),more » high brightness (1 nC, 0.3-5 ps, 5 mm.mrad, 0.2% energy spread) photo-electron bunch. The resulting x-ray brightness is expected to exceed 10{sup 20} ph/mm{sup 2}/s/mrad{sup 2}/0.1% BW. The beam is well-collimated (10 mrad divergence over the full spectrum, 1 mrad for a single color), and the source is a unique tool for time-resolved dynamic measurements in matter, including high-Z materials.« less

Resolving the X-ray emission from the Lyman-continuum emitting galaxy Tol 1247-232

NASA Astrophysics Data System (ADS)

Kaaret, P.; Brorby, M.; Casella, L.; Prestwich, A. H.

2017-11-01

Chandra observations of the nearby, Lyman-continuum (LyC) emitting galaxy Tol 1247-232 resolve the X-ray emission and show that it is dominated by a point-like source with a hard spectrum (Γ = 1.6 ± 0.5) and a high luminosity [(9 ± 2) × 1040 erg s- 1]. Comparison with an earlier XMM-Newton observation shows flux variation of a factor of 2. Hence, the X-ray emission likely arises from an accreting X-ray source: a low-luminosity active galactic nucleus or one or a few X-ray binaries. The Chandra X-ray source is similar to the point-like, hard spectrum (Γ = 1.2 ± 0.2), high-luminosity (1041 erg s- 1) source seen in Haro 11, which is the only other confirmed LyC-emitting galaxy that has been resolved in X-rays. We discuss the possibility that accreting X-ray sources contribute to LyC escape.

Lab-based x-ray nanoCT imaging

NASA Astrophysics Data System (ADS)

Müller, Mark; Allner, Sebastian; Ferstl, Simone; Dierolf, Martin; Tuohimaa, Tomi; Pfeiffer, Franz

2017-03-01

Due to the recent development of transmission X-ray tubes with very small focal spot sizes, laboratory-based CT imaging with sub-micron resolutions is nowadays possible. We recently developed a novel X-ray nanoCT setup featuring a prototype nanofocus X-ray source and a single-photon counting detector. The system is based on mere geometrical magnification and can reach resolutions of 200 nm. To demonstrate the potential of the nanoCT system for biomedical applications we show high resolution nanoCT data of a small piece of human tooth comprising coronal dentin. The reconstructed CT data clearly visualize the dentin tubules within the tooth piece.

Developing a bright 17 keV x-ray source for probing high-energy-density states of matter at high spatial resolution

NASA Astrophysics Data System (ADS)

Huntington, C. M.; Park, H.-S.; Maddox, B. R.; Barrios, M. A.; Benedetti, R.; Braun, D. G.; Hohenberger, M.; Landen, O. L.; Regan, S. P.; Wehrenberg, C. E.; Remington, B. A.

2015-04-01

A set of experiments were performed on the National Ignition Facility (NIF) to develop and optimize a bright, 17 keV x-ray backlighter probe using laser-irradiated Nb foils. High-resolution one-dimensional imaging was achieved using a 15 μm wide slit in a Ta substrate to aperture the Nb Heα x-rays onto an open-aperture, time integrated camera. To optimize the x-ray source for imaging applications, the effect of laser pulse shape and spatial profile on the target was investigated. Two laser pulse shapes were used—a "prepulse" shape that included a 3 ns, low-intensity laser foot preceding the high-energy 2 ns square main laser drive, and a pulse without the laser foot. The laser spatial profile was varied by the use of continuous phase plates (CPPs) on a pair of shots compared to beams at best focus, without CPPs. A comprehensive set of common diagnostics allowed for a direct comparison of imaging resolution, total x-ray conversion efficiency, and x-ray spectrum between shots. The use of CPPs was seen to reduce the high-energy tail of the x-ray spectrum, whereas the laser pulse shape had little effect on the high-energy tail. The measured imaging resolution was comparably high for all combinations of laser parameters, but a higher x-ray flux was achieved without phase plates. This increased flux was the result of smaller laser spot sizes, which allowed us to arrange the laser focal spots from multiple beams and produce an x-ray source which was more localized behind the slit aperture. Our experiments are a first demonstration of point-projection geometry imaging at NIF at the energies (>10 keV) necessary for imaging denser, higher-Z targets than have previously been investigated.

Forward directed x-ray from source produced by relativistic electrons from a Self-Modulated Laser Wakefield Accelerator

NASA Astrophysics Data System (ADS)

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

2017-10-01

Plasma-based particle accelerators are now able to provide the scientific community with novel light sources. Their applications span many disciplines, including high-energy density sciences, where they can be used as probes to explore the physics of dense plasmas and warm dense matter. A recent advance is in the experimental and theoretical characterization of x-ray emission from electrons in the self-modulated laser wakefield regime (SMLWFA) where little is known about the x-ray properties. A series of experiments at the LLNL Jupiter Laser Facility, using the 1 ps 150 J Titan laser, have demonstrated low divergence electron beams with energies up to 300 MeV and 6 nCs of charge, and betatron x-rays with critical energies up to 20 keV. This work identifies two other mechanisms which produce high energy broadband x-rays and gamma-rays from the SMLWFA: Bremsstrahlung and inverse Compton scattering. We demonstrate the use of Compton scattering and bremsstrahlung to generate x/Gamma-rays from 3 keV up to 1.5 MeV with a source size of 50um and a divergence of 100 mrad. This work is an important step towards developing this x-ray light source on large-scale international laser facilities, and also opens up the prospect of using them for applications. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under the contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC.

Environments of High Luminosity X-Ray Sources in the Antennae Galaxies

NASA Astrophysics Data System (ADS)

Clark, D. M.; Eikenberry, S. S.; Brandl, B. R.; Wilson, J. C.; Carson, J. C.; Henderson, C. P.; Hayward, T. P.; Barry, D. J.; Houck, J. R.; Ptak, A.; Colbert, E.

2003-12-01

We use deep J (1.25 μ m) and Ks (2.15 μ m) images of the Antennae (NGC 4038/9) obtained with the Wide-field InfraRed Camera on the Palomar 200-inch telescope, together with the Chandra X-ray source list of Zezas et al. (2001), to establish an X-ray/IR astrometric frame tie with ˜ 0.5 ″ RMS residuals over a ˜ 5 ‧ field. We find 13 ``strong" IR counterparts <1.0 ″ from X-ray sources, and an additional 6 ``possible" IR counterparts between 1.0 ″ and 1.5 ″ from X-ray sources. Based on detailed study of the surface density of IR sources near the X-ray sources, we expect only ˜ 2 of the ``strong" counterparts and ˜ 3 of the ``possible" counterparts to be chance superpositions of unrelated objects. Comparing the IR counterparts to our photometric study of ˜ 250 IR clusters in the Antennae, we find that IR counterparts to X-ray sources are Δ MK ˜ 1.2 mag more luminous than average non-X-ray clusters (>99.9% confidence), and that the X-ray/IR matches are concentrated in the spiral arms and ``bridge" regions of the Antennae. This implies that these X-ray sources lie in the most ``super" of the Antennae's Super Star Clusters, and thus trace the recent massive star formation history here. Based on the NH inferred from the X-ray sources without IR counterparts, we determine that the absence of most of the ``missing" IR counterparts is not due to extinction, but that these sources are intrinsically less luminous in the IR, implying that they trace a different (older?) stellar population. We find no clear correlation between X-ray luminosity classes and IR properties of the sources, though small number statistics hamper this analysis. Finally, we find a Ks = 16.2 mag counterpart to the Ultra-Luminous X-ray (ULX) source X-37 within <0.5 ″ , eliminating the need for the ``runaway binary" hypothesis proposed by previous authors for this object. We discuss some of the implications of this detection for models of ULX emission. This work is funded by an NSF CAREER grant.

Resonant soft X-ray scattering for polymer materials

DOE PAGES

Liu, Feng; Brady, Michael A.; Wang, Cheng

2016-04-16

Resonant Soft X-ray Scattering (RSoXS) was developed within the last few years, and the first dedicated resonant soft X-ray scattering beamline for soft materials was constructed at the Advanced Light Source, LBNL. RSoXS combines soft X-ray spectroscopy with X-ray scattering and thus offers statistical information for 3D chemical morphology over a large length scale range from nanometers to micrometers. Using RSoXS to characterize multi-length scale soft materials with heterogeneous chemical structures, we have demonstrated that soft X-ray scattering is a unique complementary technique to conventional hard X-ray and neutron scattering. Its unique chemical sensitivity, large accessible size scale, molecular bondmore » orientation sensitivity with polarized X-rays, and high coherence have shown great potential for chemically specific structural characterization for many classes of materials.« less

Continuum and line spectra of degenerate dwarf X-ray sources

NASA Technical Reports Server (NTRS)

Lamb, D. Q.

1981-01-01

Recent observations of X-ray sources are summarized. Unresolved issues concerning these sources are discussed and an outline of the kinds of X-ray observations that would best advance the understanding of these sources is presented.

Speckle-based at-wavelength metrology of X-ray mirrors with super accuracy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kashyap, Yogesh; Wang, Hongchang; Sawhney, Kawal, E-mail: kawal.sawhney@diamond.ac.uk

2016-05-15

X-ray active mirrors, such as bimorph and mechanically bendable mirrors, are increasingly being used on beamlines at modern synchrotron source facilities to generate either focused or “tophat” beams. As well as optical tests in the metrology lab, it is becoming increasingly important to optimise and characterise active optics under actual beamline operating conditions. Recently developed X-ray speckle-based at-wavelength metrology technique has shown great potential. The technique has been established and further developed at the Diamond Light Source and is increasingly being used to optimise active mirrors. Details of the X-ray speckle-based at-wavelength metrology technique and an example of its applicabilitymore » in characterising and optimising a micro-focusing bimorph X-ray mirror are presented. Importantly, an unprecedented angular sensitivity in the range of two nanoradians for measuring the slope error of an optical surface has been demonstrated. Such a super precision metrology technique will be beneficial to the manufacturers of polished mirrors and also in optimization of beam shaping during experiments.« less

Non-Quiescent X-ray Emission from Neutron Stars and Black Holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tournear, Derek M

X-ray astronomy began with the detection of the persistent source Scorpius X-1. Shortly afterwards, sources were detected that were variable. Centaurus X-2, was determined to be an X-ray transient, having a quiescent state, and a state that was much brighter. As X-ray astronomy progressed, classifications of transient sources developed. One class of sources, believed to be neutron stars, undergo extreme luminosity transitions lasting a few seconds. These outbursts are believed to be thermonuclear explosions occurring on the surface of neutron stars (type I X-ray bursts). Other sources undergo luminosity changes that cannot be explained by thermonuclear burning and last formore » days to months. These sources are soft X-ray transients (SXTs) and are believed to be the result of instabilities in the accretion of matter onto either a neutron star or black hole. Type I X-ray bursts provide a tool for probing the surfaces of neutron stars. Requiring a surface for the burning has led authors to use the presence of X-ray bursts to rule out the existence of a black hole (where an event horizon exists not a surface) for systems which exhibit type I X-ray bursts. Distinguishing between neutron stars and black holes has been a problem for decades. Narayan and Heyl have developed a theoretical framework to convert suitable upper limits on type I X-ray bursts from accreting black hole candidates (BHCs) into evidence for an event horizon. We survey 2101.2 ks of data from the USA X-ray timing experiment and 5142 ks of data from the Rossi X-ray Timing Explorer (RXTE) experiment to obtain the first formal constraint of this type. 1122 ks of neutron star data yield a population averaged mean burst rate of 1.7 {+-} 0.4 x 10{sup -5} bursts s{sup -1}, while 6081 ks of BHC data yield a 95% confidence level upper limit of 4.9 x 10{sup -7} bursts s{sup -1}. Applying the framework of Narayan and Heyl we calculate regions of luminosity where the neutron stars are expected to burst and the BHCs would be expected to burst if they had a similar surface. In this luminosity region 464 ks of neutron star data yield an averaged mean burst rate of 4.1 {+-} 0.9 x 10{sup -5} bursts s{sup -1}, and 1512 ks of BHC data yield a 95% confidence level upper limit of 2.0 x 10{sup -6} bursts s{sup -1} and a strong limit that BHCs do not burst with a rate similar to the rate of neutron stars in these regions. This gives evidence that BHCs do not have surfaces. In addition to studying type I X-ray bursts, we analyzed the SXT behavior. In particular, 4U 1630-47, was analyzed throughout its 1999 outburst. This source is one of the oldest known SXTs. This source is assumed to be a BHC in a low-mass X-ray binary system. Despite the length of time devoted to studying this source, there is still little known about it. We report the results of timing and spectral analysis on the 1999 outburst, and compare these results to other outbursts of 4U 1630-47. We found this source progressed from a low-hard state to a high-soft state and then rapidly transitioned back into the low-hard state before returning to quiescence. Timing analysis detected a low frequency quasi-periodic oscillation (LFQPO) during the initial rise of the outburst, which disappeared and did not return. The variability in the X-ray flux in the 0.1-2000 Hz frequency range is low during the high state, but increases as the source progresses into the low-hard state. The next generation Gamma Ray Large Area Space Telescope (GLAST), will measure astrophysical phenomena in the 20 MeV--a few TeV energy range. We describe preliminary design and testing of GLAST. The detector is based on a silicon tracker with similar design characteristics of vertex detectors used in high-energy physics experiments at accelerator based facilities. A beam test engineering model was designed, constructed, and tested at SLAC in 1999-2000. We describe this test, and discuss how the results from this test can improve and demonstrate the viability of the GLAST technology.« less

Long-term variability in bright hard X-ray sources: 5+ years of BATSE data

NASA Technical Reports Server (NTRS)

Robinson, C. R.; Harmon, B. A.; McCollough, M. L.; Paciesas, W. S.; Sahi, M.; Scott, D. M.; Wilson, C. A.; Zhang, S. N.; Deal, K. J.

1997-01-01

The operation of the Compton Gamma Ray Observatory (CGRO)/burst and transient source experiment (BATSE) continues to provide data for inclusion into a data base for the analysis of long term variability in bright, hard X-ray sources. The all-sky capability of BATSE provides up to 30 flux measurements/day for each source. The long baseline and the various rising and setting occultation flux measurements allow searches for periodic and quasi-periodic signals with periods of between several hours to hundreds of days to be conducted. The preliminary results from an analysis of the hard X-ray variability in 24 of the brightest BATSE sources are presented. Power density spectra are computed for each source and profiles are presented of the hard X-ray orbital modulations in some X-ray binaries, together with amplitude modulations and variations in outburst durations and intensities in recurrent X-ray transients.

Support of research in X-ray astronomy

NASA Technical Reports Server (NTRS)

Garmire, G.

1983-01-01

Activities described include: (1) the evaluation of CCD detectors for X-ray astronomy applications; (2) contributions to the development of an imaging gas scintillation proportional counter; (3) the evaluation of certain metal oxide crystals as potential radiation detectors; (4) optical observations and searches for X-ray sources discovered by the HEAO-1 A2 experiment; and (5) theoretical modeling of nonequilibrium ionization structure of supernova remnants.

Low-temperature high magnetic field powder x-ray diffraction setup for field-induced structural phase transition studies from 2 to 300 K and at 0 to 8-T field

NASA Astrophysics Data System (ADS)

Shahee, Aga; Sharma, Shivani; Kumar, Dhirendra; Yadav, Poonam; Bhardwaj, Preeti; Ghodke, Nandkishor; Singh, Kiran; Lalla, N. P.; Chaddah, P.

2016-10-01

A low-temperature and high magnetic field powder x-ray diffractometer (XRD) has been developed at UGC-DAE CSR (UGC: University Grant Commission, DAE: Department of Atomic Energy, and CSR: Consortium for scientific research), Indore, India. The setup has been developed around an 18 kW rotating anode x-ray source delivering Cu-Kα x-rays coming from a vertical line source. It works in a symmetric θ-2θ parallel beam geometry. It consists of a liquid helium cryostat with an 8 T split-pair Nb-Ti superconducting magnet comprising two x-ray windows each covering an angular range of 65°. This is mounted on a non-magnetic type heavy duty goniometer equipped with all necessary motions along with data collection accessories. The incident x-ray beam has been made parallel using a parabolic multilayer mirror. The scattered x-ray is detected using a NaI detector through a 0.1° acceptance solar collimator. To control the motions of the goniometer, a computer programme has been developed. The wide-angle scattering data can be collected in a range of 2°-115° of 2θ with a resolution of ˜0.1°. The whole setup is tightly shielded for the scattered x-rays using a lead hutch. The functioning of the goniometer and the artifacts arising possibly due to the effect of stray magnetic field on the goniometer motions, on the x-ray source, and on the detector have been characterized by collecting powder XRD data of a National Institute of Standards and Technology certified standard reference material LaB6 (SRM-660b) and Si powder in zero-field and in-field conditions. Occurrence of field induced structural-phase transitions has been demonstrated on various samples like Pr0.5Sr0.5MnO3, Nd0.49Sr0.51MnO3-δ and La0.175Pr0.45Ca0.375MnO3 by collecting data in zero field cool and field cool conditions.

Tenth International Colloquium on UV and X-Ray Spectroscopy of Astrophysical and Laboratory Plasmas

NASA Astrophysics Data System (ADS)

Silver, Eric H.; Kahn, Steven M.

UV and X-ray spectroscopy of astrophysical and laboratory plasmas draws interest from many disciplines. Contributions from international specialists are collected together in this book from a timely recent conference. In astrophysics, the Hubble Space Telescope, Astro 1 and ROSAT observatories are now providing UV and X-ray spectra and images of cosmic sources in unprecedented detail, while the Yohkoh mission recently collected superb data on the solar corona. In the laboratory, the development of ion-trap facilities and novel laser experiments are providing vital new data on high temperature plasmas. Recent innovations in the technology of spectroscopic instrumentation are discussed. These papers constitute an excellent up-to-date review of developments in short-wavelength spectroscopy and offer a solid introduction to its theoretical and experimental foundations. These proceedings give an up-to-date review of developments in short-wavelength spectroscopy and offer a solid introduction to its theoretical and experimental foundations. Various speakers presented some of the first results from the high resolution spectrograph on the Hubble Space Telescope, the high sensitivity far ultraviolet and X-ray spectrometers of the ASTRO 1 Observatory, the imaging X-ray spectrometer on the ROSAT Observatory, and the high resolution solar X-ray spectrometer on Yohkoh. The development of ion trap devices had brought about a revolution in laboratory investigations of atomic processes in highly charged atoms. X-ray laser experiments had not only yielded considerable insight into electron ion interactions in hot dense plasmas, but also demonstrated the versatility of laser plasmas as laboratory X-ray sources. Such measurements also motivated and led to refinements in the development of large-scale atomic and molecular codes. On the instrumental side, the design and development of the next series of very powerful short wavelength observatories had generated a large number of technological innovations in both dispersive and nondispersive spectroscopic instrumentation.

Development Of Hard X-Ray Sources With High Radiative Power Output At The National Ignition Facility Utilizing Molybdenum and Silver Cavities

NASA Astrophysics Data System (ADS)

Widmann, Klaus; Benjamin, Russ; May, Mark; Thorn, Daniel; Colvin, Jeff; Barrios, Maria; Kemp, G. Elijah; Fournier, Kevin; Blue, Brent

2016-10-01

In our on-going x-ray source development campaign at the National Ignition Facility, we have recently extended the energy range of our laser-driven cavity sources to the 20 keV range by utilizing molybdenum-lined and silver-lined cavity targets. Using a variety of spectroscopic and power diagnostics we determined that almost 1% of the nearly 1 MJ total laser energy used for heating the cavity target was converted to Mo K-shell x rays using our standard cavity design. The same laser drive for silver-lined cavities yielded about 0.4% conversion efficiency for the Ag K-shell emission. Comparison with HYDRA simulations are used to further optimize the x-rays conversion efficiency. The simulations indicate that minor changes in the aspect ratio of the cavity and the layer thickness may double the radiative power of the K-shell emission. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

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.

A Possible X-Ray and Radio Counterpart of the High-Energy Gamma-Ray Source 3EG J2227+6122

NASA Technical Reports Server (NTRS)

Halpern, Jules P.; Gotthelf, E. V.; Helfand, D. J.; Leighly, K. M.; Oliversen, Ronald (Technical Monitor)

2001-01-01

The identity of the persistent EGRET sources in the Galactic plane is largely a mystery. For one of these, 3EG J2227+6122, our complete census of X-ray and radio sources in its error circle reveals a remarkable superposition of an incomplete radio shell with a flat radio spectrum, and a compact, power-law X-ray source with photon index Gamma = 1.5 and with no obvious optical counterpart. The radio shell is polarized at a level of approx. = 25%. The anomalous properties of the radio source prevent us from deriving a completely satisfactory theory as to its nature. Nevertheless, using data from ROSAT, ASCA, the VLA, and optical imaging and spectroscopy, we argue that the X-ray source may be a young pulsar with an associated wind-blown bubble or bow shock nebula, and an example of the class of radio-quiet pulsars which are hypothesized to comprise the majority of EGRET sources in the Galaxy. The distance to this source can be estimated from its X-ray absorption as 3 kpc. At this distance, the X-ray and gamma-ray luminosities would be approx. = 1.7 x 10(exp 33) and approx. = 3.7 x 10(exp 35) erg/s, respectively, which would require an energetic pulsar to power them. If, on the contrary, this X-ray source is not the counterpart of 3EG J2227+6122, then by process of elimination the X-ray luminosity of the latter must be less than 10(exp -4) of its gamma-ray luminosity, a condition not satisfied by any established class of gamma-ray source counterpart. This would require the existence of at least a quantitatively new type of EGRET source, as has been suggested in studies of other EGRET fields.

In-situ X-ray diffraction system using sources and detectors at fixed angular positions

DOEpatents

Gibson, David M [Voorheesville, NY; Gibson, Walter M [Voorheesville, NY; Huang, Huapeng [Latham, NY

2007-06-26

An x-ray diffraction technique for measuring a known characteristic of a sample of a material in an in-situ state. The technique includes using an x-ray source for emitting substantially divergent x-ray radiation--with a collimating optic disposed with respect to the fixed source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation. A first x-ray detector collects radiation diffracted from the sample; wherein the source and detector are fixed, during operation thereof, in position relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample. A second x-ray detector may be fixed relative to the first x-ray detector according to the a-priori knowledge about the known characteristic of the sample, especially in a phase monitoring embodiment of the present invention.

X-ray lithography source

DOEpatents

Piestrup, Melvin A.; Boyers, David G.; Pincus, Cary

1991-01-01

A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

X-ray phase-contrast tomosynthesis of a human ex vivo breast slice with an inverse Compton x-ray source

NASA Astrophysics Data System (ADS)

Eggl, E.; Schleede, S.; Bech, M.; Achterhold, K.; Grandl, S.; Sztrókay, A.; Hellerhoff, K.; Mayr, D.; Loewen, R.; Ruth, R. D.; Reiser, M. F.; Pfeiffer, F.

2016-12-01

While the performance of conventional x-ray tube sources often suffers from the broad polychromatic spectrum, synchrotrons that could provide highly brilliant x-rays are restricted to large research facilities and impose high investment and maintenance costs. Lately, a new type of compact synchrotron sources has been investigated. These compact light sources (CLS) based on inverse Compton scattering provide quasi-monochromatic hard x-rays. The flux and brilliance yielded by a CLS currently lie between x-ray tube sources and third-generation synchrotrons. The relatively large partially coherent x-ray beam is well suited for the investigation of preclinical applications of grating-based phase-contrast and dark-field imaging. Here we present the first grating-based multimodal tomosynthesis images of a human breast slice acquired at a CLS to investigate the possibilities of improved breast cancer diagnostics.

Globular cluster x-ray sources

PubMed Central

Pooley, David

2010-01-01

Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 1036 ergs-1) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (< 1033 ergs-1) x-ray sources. It was realized early on that the high-luminosity sources were low-mass x-ray binaries in outburst and that they were orders of magnitude more abundant per unit mass in globular clusters than in the rest of the galaxy. However, the low-luminosity sources proved difficult to classify. Many ideas were put forth—low-mass x-ray binaries in quiescence (qLMXBs), cataclysmic variables (CVs), active main-sequence binaries (ABs), and millisecond pulsars (MSPs)—but secure identifications were scarce. In ROSAT observations of 55 clusters, about 25 low-luminosity sources were found. Chandra has now observed over 80 Galactic globular clusters, and these observations have revealed over 1,500 x-ray sources. The superb angular resolution has allowed for many counterpart identifications, providing clues to the nature of this population. It is a heterogeneous mix of qLMXBs, CVs, ABs, and MSPs, and it has been shown that the qLMXBs and CVs are both, in part, overabundant like the luminous LMXBs. The number of x-ray sources in a cluster correlates very well with its encounter frequency. This points to dynamical formation scenarios for the x-ray sources and shows them to be excellent tracers of the complicated internal dynamics. The relation between the encounter frequency and the number of x-ray sources has been used to suggest that we have misunderstood the dynamical states of globular clusters. PMID:20404204

X-ray Binaries in the Central Region of M31

NASA Astrophysics Data System (ADS)

Trudolyubov, Sergey P.; Priedhorsky, W. C.; Cordova, F. A.

2006-09-01

We present the results of the systematic survey of X-ray sources in the central region of M31 using the data of XMM-Newton observations. The spectral properties and variability of 124 bright X-ray sources were studied in detail. We found that more than 80% of sources observed in two or more observations show significant variability on the time scales of days to years. At least 50% of the sources in our sample are spectrally variable. The fraction of variable sources in our survey is much higher than previously reported from Chandra survey of M31, and is remarkably close to the fraction of variable sources found in M31 globular cluster X-ray source population. We present spectral distribution of M31 X-ray sources, based on the spectral fitting with a power law model. The distribution of spectral photon index has two main peaks at 1.8 and 2.3, and shows clear evolution with source luminosity. Based on the similarity of the properties of M31 X-ray sources and their Galactic counterparts, we expect most of X-ray sources in our sample to be accreting binary systems with neutron star and black hole primaries. Combining the results of X-ray analysis (X-ray spectra, hardness-luminosity diagrams and variability) with available data at other wavelengths, we explore the possibility of distinguishing between bright neutron star and black hole binary systems, and identify 7% and 25% of sources in our sample as a probable black hole and neutron star candidates. Finally, we compare the M31 X-ray source population to the source populations of normal galaxies of different morphological type. Support for this work was provided through NASA Grant NAG5-12390. Part of this work was done during a summer workshop ``Revealing Black Holes'' at the Aspen Center for Physics, S. T. is grateful to the Center for their hospitality.

Transmission type flat-panel X-ray source using ZnO nanowire field emitters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Daokun; Song, Xiaomeng; Zhang, Zhipeng

2015-12-14

A transmission type flat-panel X-ray source in diode structure was fabricated. Large-scale patterned ZnO nanowires grown on a glass substrate by thermal oxidation were utilized as field emitters, and tungsten thin film coated on silica glass was used as the transmission anode. Uniform distribution of X-ray generation was achieved, which benefited from the uniform electron emission from ZnO nanowires. Self-ballasting effect induced by the intrinsic resistance of ZnO nanowire and decreasing of screening effect caused by patterned emitters account for the uniform emission. Characteristic X-ray peaks of W-L lines and bremsstrahlung X-rays have been observed under anode voltages at amore » range of 18–20 kV, the latter of which were the dominant X-ray signals. High-resolution X-ray images with spatial resolution less than 25 μm were obtained by the flat-panel X-ray source. The high resolution was attributed to the small divergence angle of the emitted X-rays from the transmission X-ray source.« less

Chandra-SDSS Normal and Star-Forming Galaxies. I. X-Ray Source Properties of Galaxies Detected by the Chandra X-Ray Observatory in SDSS DR2

NASA Astrophysics Data System (ADS)

Hornschemeier, A. E.; Heckman, T. M.; Ptak, A. F.; Tremonti, C. A.; Colbert, E. J. M.

2005-01-01

We have cross-correlated X-ray catalogs derived from archival Chandra X-Ray Observatory ACIS observations with a Sloan Digital Sky Survey Data Release 2 (DR2) galaxy catalog to form a sample of 42 serendipitously X-ray-detected galaxies over the redshift interval 0.03

Inverse compton light source: a compact design proposal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deitrick, Kirsten Elizabeth

In the last decade, there has been an increasing demand for a compact Inverse Compton Light Source (ICLS) which is capable of producing high-quality X-rays by colliding an electron beam and a high-quality laser. It is only in recent years when both SRF and laser technology have advanced enough that compact sources can approach the quality found at large installations such as the Advanced Photon Source at Argonne National Laboratory. Previously, X-ray sources were either high flux and brilliance at a large facility or many orders of magnitude lesser when produced by a bremsstrahlung source. A recent compact source wasmore » constructed by Lyncean Technologies using a storage ring to produce the electron beam used to scatter the incident laser beam. By instead using a linear accelerator system for the electron beam, a significant increase in X-ray beam quality is possible, though even subsequent designs also featuring a storage ring offer improvement. Preceding the linear accelerator with an SRF reentrant gun allows for an extremely small transverse emittance, increasing the brilliance of the resulting X-ray source. In order to achieve sufficiently small emittances, optimization was done regarding both the geometry of the gun and the initial electron bunch distribution produced off the cathode. Using double-spoke SRF cavities to comprise the linear accelerator allows for an electron beam of reasonable size to be focused at the interaction point, while preserving the low emittance that was generated by the gun. An aggressive final focusing section following the electron beam's exit from the accelerator produces the small spot size at the interaction point which results in an X-ray beam of high flux and brilliance. Taking all of these advancements together, a world class compact X-ray source has been designed. It is anticipated that this source would far outperform the conventional bremsstrahlung and many other compact ICLSs, while coming closer to performing at the levels found at large facilities than ever before. The design process, including the development between subsequent iterations, is presented here in detail, with the simulation results for this groundbreaking X-ray source.« less

An X-ray Observation of the L1251 Dark Cloud

NASA Technical Reports Server (NTRS)

Simon, Theodore

2006-01-01

An X-ray image of the L1251 dark cloud in Cepheus was obtained with the XMM-Newton telescope. More than three dozen sources were detected above a 3 delta limit in X-ray luminosity of L(sub X = 10(exp 29) ergs/s. Among the detections are eight optically visible T Tauri stars, which had been identified in earlier work from their emission at H(alpha). The two strongest X-ray sources have steady luminosities of L(sub X) approx. 10(exp 31) ergs/s and are at the saturation limit for X-ray activity in late-type stars, L(sub X)/L(sub bol) approx. 10(exp -3). X-ray emission was also observed from two CO emission cores in L1251, core C (L1251A) and core E (L1251B). Both regions contain high-velocity molecular gas, bright IRAS sources (Class I protostars), thermal radio sources, and Herbig-Haro (HH) jets. In L1251A strong X-ray emission was discovered in close proximity to the near-inbred and radio source IRSA/VLA 7 and to IRAS 22343+7501. IRSA/VLA 7 thus appears to be the most likely source of the molecular and HH outflows in L1251A. In L1251B X-ray emission was observed from a visible T Tauri star, KP2-44, which is thought to be the driving source for HH 189. Also reported is the tentative detection of X-ray emission from VLA 3, a thermal radio continuum source in L1251B that is closely associated with the extreme Class I protostar IRAS 22376+7455.

Superwind evolution: the young starburst-driven wind galaxy NGC 2782

NASA Astrophysics Data System (ADS)

Bravo-Guerrero, Jimena; Stevens, Ian R.

2017-06-01

We present results from a 30-ks Chandra observation of the important starburst galaxy NGC 2782, covering the 0.3-10 keV energy band. We find evidence of a superwind of small extent, which is likely in an early stage of development. We find a total of 27 X-ray point sources within a region of radius 2D25 of the galaxy centre and that are likely associated with the galaxy. Of these, 13 are ultraluminous X-ray point sources (ULXs; LX ≥ 1039 erg s- 1) and a number have likely counterparts. The X-ray luminosities of the ULX candidates are 1.2-3.9 × 1039 erg s- 1. NGC 2782 seems to have an unusually large number of ULXs. Central diffuse X-ray emission extending to ˜3 kpc from the nuclear region has been detected. We also find an X-ray structure to the south of the nucleus, coincident with Hα filaments and with a 5-GHz radio source. We interpret this as a blow-out region of a forming superwind. This X-ray bubble has a total luminosity (0.3-10 keV) of 5 × 1039 erg s-1 (around 15 per cent of the total luminosity of the extended emission), and an inferred wind mass of 1.5 × 106 M⊙ . We also discuss the nature of the central X-ray source in NGC 2782, and conclude that it is likely a low-luminosity active galactic nucleus, with a total X-ray luminosity of LX = 6 × 1040 erg s-1, with strong Fe line emission at 6.4 keV.

Procedures for cryogenic X-ray ptychographic imaging of biological samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yusuf, M.; Zhang, F.; Chen, B.

Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This paper describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

Procedures for cryogenic X-ray ptychographic imaging of biological samples

DOE PAGES

Yusuf, M.; Zhang, F.; Chen, B.; ...

2017-01-12

Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This paper describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

Observational Aspects of Hard X-ray Polarimetry

NASA Astrophysics Data System (ADS)

Chattopadhyay, Tanmoy

2016-04-01

Sensitive polarization measurements in X-ray may address a wealth of astrophysical phenomena, which so far remain beyond our understanding through available X-ray spectroscopic, imaging, and timing studies. Though scientific potential of X-ray polarimetry was realized long ago, there has not been any significant advancement in this field for the last four decades since the birth of X-ray astronomy. The only successful polarization measurement in X-rays dates back to 1976, when a Bragg polarimeter onboard OSO-8 measured polarization of Crab nebula. Primary reason behind the lack in progress is its extreme photon hungry nature, which results in poor sensitivity of the polarimeters. Recently, in the last decade or so, with the advancement in detection technology, X-ray polarimetry may see a significant progress in near future, especially in soft X-rays with the invention of photoelectron tracking polarimeters. Though photoelectric polarimeters are expected to provide sensitive polarization measurements of celestial X-ray sources, they are sensitive only in soft X-rays, where the radiation from the sources is dominated by thermal radiation and therefore expected to be less polarized. On the other hand, in hard X-rays, sources are ex-pected to be highly polarized due to the dominance of nonthermal emission over its thermal counterpart. Moreover, polarization measurements in hard X-rays promises to address few interesting scientific issues regarding geometry of corona for black hole sources, emission mechanism responsible for the higher energy peak in the blazars, accretion geometry close to the magnetic poles in accreting neutron star systems and acceleration mechanism in solar flares. Compton polarimeters provide better sensitivity than photoelectric polarimeters in hard X-rays with a broad energy band of operation. Recently, with the development of hard X-ray focusing optics e.g. NuSTAR, Astro-H, it is now possible to conceive Compton polarimeters at the focal plane of such hard X-ray telescopes, which may provide sensitive polarization measurements due to flux concentration in hard X-rays with a very low background. On the other hand, such a configuration ensures implementation of an optimized geometry close to an ideal one for the Compton polarimeters. In this context, we initiated the development of a focal plane Compton polarimeter, consisting of a plastic scatterer surrounded by a cylindrical array of CsI(Tl) scintillators. Geant-4 simulations of the planned configuration estimates 1% MDP for a 100 mCrab source in 1 million seconds of exposure. Sensitivity of the instrument is found to be critically dependent on the lower energy detection limit of the plastic scatterer; lower the threshold, better is the sensitivity. In the actual experiment, the plastic is readout by a photomultiplier tube procured from Saint-Gobain. We carried out extensive experiments to characterize the plastic especially for lower energy depositions. The CsI(Tl) scintillators are readout by Si photomultipliers (SiPM). SiPMs are small in size and robust and therefore provide the compactness necessary for the designing of focal plane detectors. Each of the CsI(Tl)-SiPM systems was characterized precisely to estimate their energy threshold and detection probability along the length of the scintillators away from SiPM. Finally, we integrated the Compton polarimeter and tested its response to polarized and unpolarized radiation and compared the experimental results with Geant-4 simulation. Despite the growing realization of the scientific values of X-ray polarimetry and the efforts in developing sensitive X-ray polarimeters, there has not been a single dedicated X-ray polarimetry mission planned in near future. In this scenario, it is equally important to attempt polarization measurements from the existing or planned instruments which are not meant for X-ray polarization measurements but could be sensitive to it. There have been several attempts in past in retrieving polarization information from few of such spectroscopic instruments like RHESSI, INTEGRAL-IBIS, INTEGRAL-SPI. Cadmium Zinc Telluride Imager (CZTI) onboard Astrosat, India's first astronomical mission, is one of such instruments which is expected to provide sensitive polarization measurements for bright X-ray sources. CZTI consists of 64 CZT detector modules, each of which is 5 mm thick and 4 cm × 4 cm in size. Each CZT module is subdivided into 256 pixels with pixel pitch of 2.5 mm. Due to its pixelation nature and significant Compton scattering efficiency at energies beyond 100 keV, CZTI can work as a sensitive Compton polarimeter in hard X-rays. Detailed Geant-4 simulations and polarization experiments with the flight configuration of CZTI show that CZTI will have significant polarization measurement capability for bright sources in hard X-rays. CZTI is primarily a spectroscopic instrument with coded mask imaging. To properly utilize the spectroscopic capabilities of CZT detectors, it is important to generate accurate response matrix for CZTI, which in turn requires precise modelling of the CZT lines shapes for monoenergetic X-ray interaction. CZT detectors show an extended lower energy tail of an otherwise Gaussian line shape due to low mobility and lifetime of the charge carriers. On the other hand, interpixel charge sharing may also contribute to the lower energy tail making the line shape more complicated. We have developed a model to predict the line shapes from CZTI modules taking into account the mobility and lifetime of the charge carriers and charge sharing fractions. The model predicts the line shape quite well and can be used to generate pixel-wise response matrix for CZTI.

X-ray astronomy from Uhuru to HEAO-1

NASA Technical Reports Server (NTRS)

Clark, G. W.

1981-01-01

The nature of galactic and extragalactic X-ray sources is investigated using observations made with nine satellites and several rockets. The question of X-ray pulsars being neutron stars or white dwarfs is considered, as is the nature of Population II and low-luminosity X-ray stars, the diffuse X-ray emission from clusters of galaxies, the unidentified high-galactic-latitude (UHGL) sources, and the unresolved soft X-ray background. The types of sources examined include binary pulsars, Population II X-ray stars (both nonbursters and bursters) inside and outside globular clusters, coronal X-ray emitters, and active galactic nuclei. It is concluded that: (1) X-ray pulsars are strongly magnetized neutron stars formed in the evolution of massive close binaries; (2) all Population II X-ray stars are weakly magnetized or nonmagnetic neutron stars accreting from low-mass companions in close binary systems; (3) the diffuse emission from clusters is thermal bremsstrahlung of hot matter processed in stars and swept out by ram pressure exerted by the intergalactic gas; (4) most or all of the UHGL sources are active galactic nuclei; and (5) the soft X-ray background is emission from a hot component of the interstellar medium.

The Identification Of The X-Ray Counterpart To PSR J2021+4026

DOE PAGES

Weisskopf, Martin C.; Romani, Roger W.; Razzano, Massimiliano; ...

2011-11-23

We report the probable identification of the X-ray counterpart to the γ-ray pulsar PSR J2021+4026 using imaging with the Chandra X-ray Observatory ACIS and timing analysis with the Fermi satellite. Given the statistical and systematic errors, the positions determined by both satellites are coincident. The X-ray source position is R.A. 20h21m30s.733, Decl. +40°26'46.04" (J2000) with an estimated uncertainty of 1."3 combined statistical and systematic error. Moreover, both the X-ray to γ-ray and the X-ray to optical flux ratios are sensible assuming a neutron star origin for the X-ray flux. The X-ray source has no cataloged infrared-to-visible counterpart and, through newmore » observations, we set upper limits to its optical emission of i' > 23.0 mag and r' > 25.2 mag. The source exhibits an X-ray spectrum with most likely both a powerlaw and a thermal component. We also report on the X-ray and visible light properties of the 43 other sources detected in our Chandra observation.« less

Control of the Low-energy X-rays by Using MCNP5 and Numerical Analysis for a New Concept Intra-oral X-ray Imaging System

NASA Astrophysics Data System (ADS)

Huh, Jangyong; Ji, Yunseo; Lee, Rena

2018-05-01

An X-ray control algorithm to modulate the X-ray intensity distribution over the FOV (field of view) has been developed by using numerical analysis and MCNP5, a particle transport simulation code on the basis of the Monte Carlo method. X-rays, which are widely used in medical diagnostic imaging, should be controlled in order to maximize the performance of the X-ray imaging system. However, transporting X-rays, like a liquid or a gas is conveyed through a physical form such as pipes, is not possible. In the present study, an X-ray control algorithm and technique to uniformize the Xray intensity projected on the image sensor were developed using a flattening filter and a collimator in order to alleviate the anisotropy of the distribution of X-rays due to intrinsic features of the X-ray generator. The proposed method, which is combined with MCNP5 modeling and numerical analysis, aimed to optimize a flattening filter and a collimator for a uniform distribution of X-rays. Their size and shape were estimated from the method. The simulation and the experimental results both showed that the method yielded an intensity distribution over an X-ray field of 6×4 cm2 at SID (source to image-receptor distance) of 5 cm with a uniformity of more than 90% when the flattening filter and the collimator were mounted on the system. The proposed algorithm and technique are not only confined to flattening filter development but can also be applied for other X-ray related research and development efforts.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ice, G.E.; Barbee, T.; Bionta, R.

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

X-ray Lobster Eye all-sky monitor for rocket experiment

NASA Astrophysics Data System (ADS)

Dániel, V.; Inneman, A.; Pína, L.; Zadražil, V.; Báča, T.; Stehlíková, V.; Nentvich, O.; Urban, M.; Maršíková, V.; McEntaffer, R.; Tutt, J.; Schulz, T.

2017-05-01

This paper presents a Lobster Eye (LE) X-ray telescope developed for the Water Recovery X-ray Rocket (WRX-R) experiment. The primary payload of the rocket experiment is a soft X-ray spectroscope developed by the Pennsylvania State University (PSU), USA. The Czech team participates by hard LE X-ray telescope as a secondary payload. The astrophysical objective of the rocket experiment is the Vela Supernova of size about 8deg x 8deg. In the center of the nebula is a neutron star with a strong magnetic field, roughly the mass of the Sun and a diameter of about 20 kilometers forming the Vela pulsar. The primary objective of WRX-R is the spectral measurement of the outer part of the nebula in soft X-ray and FOV of 3.25deg x 3.25deg. The secondary objective (hard LE X-ray telescope) is the Vela neutron star observation. The hard LE telescope consists of two X-ray telescopes with the Timepix detector. First telescope uses 2D LE Schmidt optics (2DLE- REX) with focal length over 1m and 4 Timepix detectors (2x2 matrix). The telescope FOV is 1.5deg x 1.5deg with spectral range from 3keV to 60keV. The second telescope uses 1D LE Schmidt optics (1D-LE-REX) with focal length of 25 cm and one Timepix detector. The telescope is made as a wide field with FOV 4.5deg x 3.5deg and spectral range from 3keV to 40keV. The rocket experiment serves as a technology demonstration mission for the payloads. The LE X-ray telescopes can be in the future used as all-sky monitor/surveyor. The astrophysical observation can cover the hard X-ray observation of astrophysical sources in time-domain, the GRBs surveying or the exploration of the gravitational wave sources.

Materials identification using a small-scale pixellated x-ray diffraction system

NASA Astrophysics Data System (ADS)

O'Flynn, D.; Crews, C.; Drakos, I.; Christodoulou, C.; Wilson, M. D.; Veale, M. C.; Seller, P.; Speller, R. D.

2016-05-01

A transmission x-ray diffraction system has been developed using a pixellated, energy-resolving detector (HEXITEC) and a small-scale, mains operated x-ray source (Amptek Mini-X). HEXITEC enables diffraction to be measured without the requirement of incident spectrum filtration, or collimation of the scatter from the sample, preserving a large proportion of the useful signal compared with other diffraction techniques. Due to this efficiency, sufficient molecular information for material identification can be obtained within 5 s despite the relatively low x-ray source power. Diffraction data are presented from caffeine, hexamine, paracetamol, plastic explosives and narcotics. The capability to determine molecular information from aspirin tablets inside their packaging is demonstrated. Material selectivity and the potential for a sample classification model is shown with principal component analysis, through which each different material can be clearly resolved.

Instrumentation and Future Missions in the Upcoming Era of X-ray Polarimetry

NASA Astrophysics Data System (ADS)

Fabiani, Sergio

2018-05-01

The maturity of current detectors based on technologies that range from solid state to gases renewed the interest for X-ray polarimetry, raising the enthusiasm of a wide scientific community to improve the performance of polarimeters as well as to produce more detailed theoretical predictions. We will introduce the basic concepts about measuring the polarization of photons, especially in the X-rays, and we will review the current state of the art of polarimeters in a wide energy range from soft~to hard X-rays, from solar flares to distant astrophysical sources. We will introduce relevant examples of polarimeters developed from the recent past up to the panorama of upcoming space missions to show how the recent development of the technology is allowing reopening the observational window of X-ray polarimetry.

Development of an adaptable coherent x-ray diffraction microscope with the emphasis on imaging hydrated specimens.

PubMed

Nam, Daewoong; Park, Jaehyun; Gallagher-Jones, Marcus; Shimada, Hiroki; Kim, Sangsoo; Kim, Sunam; Kohmura, Yoshiki; Ishikawa, Tetsuya; Song, Changyong

2013-11-01

This paper describes the development of a versatile coherent x-ray diffraction microscope capable of imaging biological specimens in solution. The microscope is a flexible platform accommodating various conditions, from low vacuum (10(-2) Pa) to helium gas filled ambient pressure. This flexibility greatly expands the application area, from in situ materials science to biology systems in their native state, by significantly relaxing restrictions to the sample environment. The coherent diffraction microscope has been used successfully to image a yeast cell immersed in buffer solution. We believe that the design of this coherent diffraction microscope can be directly adapted to various platforms such as table top soft x-ray laser, synchrotron x-ray sources, and x-ray free electron laser with minor relevant adjustments.

Development of an adaptable coherent x-ray diffraction microscope with the emphasis on imaging hydrated specimens

NASA Astrophysics Data System (ADS)

Nam, Daewoong; Park, Jaehyun; Gallagher-Jones, Marcus; Shimada, Hiroki; Kim, Sangsoo; Kim, Sunam; Kohmura, Yoshiki; Ishikawa, Tetsuya; Song, Changyong

2013-11-01

This paper describes the development of a versatile coherent x-ray diffraction microscope capable of imaging biological specimens in solution. The microscope is a flexible platform accommodating various conditions, from low vacuum (10-2 Pa) to helium gas filled ambient pressure. This flexibility greatly expands the application area, from in situ materials science to biology systems in their native state, by significantly relaxing restrictions to the sample environment. The coherent diffraction microscope has been used successfully to image a yeast cell immersed in buffer solution. We believe that the design of this coherent diffraction microscope can be directly adapted to various platforms such as table top soft x-ray laser, synchrotron x-ray sources, and x-ray free electron laser with minor relevant adjustments.

The Chandra Source Catalog

NASA Astrophysics Data System (ADS)

Evans, Ian N.; Primini, Francis A.; Glotfelty, Kenny J.; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Davis, John E.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G., II; Grier, John D.; Hain, Roger M.; Hall, Diane M.; Harbo, Peter N.; He, Xiangqun Helen; Houck, John C.; Karovska, Margarita; Kashyap, Vinay L.; Lauer, Jennifer; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph B.; Mitschang, Arik W.; Morgan, Douglas L.; Mossman, Amy E.; Nichols, Joy S.; Nowak, Michael A.; Plummer, David A.; Refsdal, Brian L.; Rots, Arnold H.; Siemiginowska, Aneta; Sundheim, Beth A.; Tibbetts, Michael S.; Van Stone, David W.; Winkelman, Sherry L.; Zografou, Panagoula

2010-07-01

The Chandra Source Catalog (CSC) is a general purpose virtual X-ray astrophysics facility that provides access to a carefully selected set of generally useful quantities for individual X-ray sources, and is designed to satisfy the needs of a broad-based group of scientists, including those who may be less familiar with astronomical data analysis in the X-ray regime. The first release of the CSC includes information about 94,676 distinct X-ray sources detected in a subset of public Advanced CCD Imaging Spectrometer imaging observations from roughly the first eight years of the Chandra mission. This release of the catalog includes point and compact sources with observed spatial extents lsim30''. The catalog (1) provides access to the best estimates of the X-ray source properties for detected sources, with good scientific fidelity, and directly supports scientific analysis using the individual source data; (2) facilitates analysis of a wide range of statistical properties for classes of X-ray sources; and (3) provides efficient access to calibrated observational data and ancillary data products for individual X-ray sources, so that users can perform detailed further analysis using existing tools. The catalog includes real X-ray sources detected with flux estimates that are at least 3 times their estimated 1σ uncertainties in at least one energy band, while maintaining the number of spurious sources at a level of lsim1 false source per field for a 100 ks observation. For each detected source, the CSC provides commonly tabulated quantities, including source position, extent, multi-band fluxes, hardness ratios, and variability statistics, derived from the observations in which the source is detected. In addition to these traditional catalog elements, for each X-ray source the CSC includes an extensive set of file-based data products that can be manipulated interactively, including source images, event lists, light curves, and spectra from each observation in which a source is detected.

The Einstein Slew Survey

NASA Technical Reports Server (NTRS)

Elvis, Martin; Plummer, David; Schachter, Jonathan; Fabbiano, G.

1992-01-01

A catalog of 819 sources detected in the Einstein IPC Slew Survey of the X-ray sky is presented; 313 of the sources were not previously known as X-ray sources. Typical count rates are 0.1 IPC count/s, roughly equivalent to a flux of 3 x 10 exp -12 ergs/sq cm s. The sources have positional uncertainties of 1.2 arcmin (90 percent confidence) radius, based on a subset of 452 sources identified with previously known pointlike X-ray sources (i.e., extent less than 3 arcmin). Identifications based on a number of existing catalogs of X-ray and optical objects are proposed for 637 of the sources, 78 percent of the survey (within a 3-arcmin error radius) including 133 identifications of new X-ray sources. A public identification data base for the Slew Survey sources will be maintained at CfA, and contributions to this data base are invited.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

X-ray lithography using holographic images

DOEpatents

Howells, Malcolm R.; Jacobsen, Chris

1995-01-01

A non-contact X-ray projection lithography method for producing a desired X-ray image on a selected surface of an X-ray-sensitive material, such as photoresist material on a wafer, the desired X-ray image having image minimum linewidths as small as 0.063 .mu.m, or even smaller. A hologram and its position are determined that will produce the desired image on the selected surface when the hologram is irradiated with X-rays from a suitably monochromatic X-ray source of a selected wavelength .lambda.. On-axis X-ray transmission through, or off-axis X-ray reflection from, a hologram may be used here, with very different requirements for monochromaticity, flux and brightness of the X-ray source. For reasonable penetration of photoresist materials by X-rays produced by the X-ray source, the wavelength X, is preferably chosen to be no more than 13.5 nm in one embodiment and more preferably is chosen in the range 1-5 nm in the other embodiment. A lower limit on linewidth is set by the linewidth of available microstructure writing devices, such as an electron beam.

Energy-angle correlation correction algorithm for monochromatic computed tomography based on Thomson scattering X-ray source

NASA Astrophysics Data System (ADS)

Chi, Zhijun; Du, Yingchao; Huang, Wenhui; Tang, Chuanxiang

2017-12-01

The necessity for compact and relatively low cost x-ray sources with monochromaticity, continuous tunability of x-ray energy, high spatial coherence, straightforward polarization control, and high brightness has led to the rapid development of Thomson scattering x-ray sources. To meet the requirement of in-situ monochromatic computed tomography (CT) for large-scale and/or high-attenuation materials based on this type of x-ray source, there is an increasing demand for effective algorithms to correct the energy-angle correlation. In this paper, we take advantage of the parametrization of the x-ray attenuation coefficient to resolve this problem. The linear attenuation coefficient of a material can be decomposed into a linear combination of the energy-dependent photoelectric and Compton cross-sections in the keV energy regime without K-edge discontinuities, and the line integrals of the decomposition coefficients of the above two parts can be determined by performing two spectrally different measurements. After that, the line integral of the linear attenuation coefficient of an imaging object at a certain interested energy can be derived through the above parametrization formula, and monochromatic CT can be reconstructed at this energy using traditional reconstruction methods, e.g., filtered back projection or algebraic reconstruction technique. Not only can monochromatic CT be realized, but also the distributions of the effective atomic number and electron density of the imaging object can be retrieved at the expense of dual-energy CT scan. Simulation results validate our proposal and will be shown in this paper. Our results will further expand the scope of application for Thomson scattering x-ray sources.

Microfocus/Polycapillary-Optic Crystallographic X-Ray System

NASA Technical Reports Server (NTRS)

Joy, Marshall; Gubarev, Mikhail; Ciszak, Ewa

2005-01-01

A system that generates an intense, nearly collimated, nearly monochromatic, small-diameter x-ray beam has been developed for use in macromolecular crystallography. A conventional x-ray system for macromolecular crystallography includes a rotating-anode x-ray source, which is massive (.500 kg), large (approximately 2 by 2 by 1 m), and power-hungry (between 2 and 18 kW). In contrast, the present system generates a beam of the required brightness from a microfocus source, which is small and light enough to be mounted on a laboratory bench, and operates at a power level of only tens of watts. The figure schematically depicts the system as configured for observing x-ray diffraction from a macromolecular crystal. In addition to the microfocus x-ray source, the system includes a polycapillary optic . a monolithic block (typically a bundle of fused glass tubes) that contains thousands of straight or gently curved capillary channels, along which x-rays propagate with multiple reflections. This particular polycapillary optic is configured to act as a collimator; the x-ray beam that emerges from its output face consists of quasi-parallel subbeams with a small angular divergence and a diameter comparable to the size of a crystal to be studied. The gap between the microfocus x-ray source and the input face of the polycapillary optic is chosen consistently with the focal length of the polycapillary optic and the need to maximize the solid angle subtended by the optic in order to maximize the collimated x-ray flux. The spectrum from the source contains a significant component of Cu K (photon energy is 8.08 keV) radiation. The beam is monochromatized (for Cu K ) by a nickel filter 10 m thick. In a test, this system was operated at a power of 40 W (current of 897 A at an accelerating potential of 45 kV), with an anode x-ray spot size of 41+/-2 microns. Also tested, in order to provide a standard for comparison, was a commercial rotating-anode x-ray crystallographic system with a pyrolytic graphite monochromator and a 250-micron pinhole collimator, operating at a power of 3.15 kW (current of 70 mA at an accelerating potential of 45 kV). The flux of collimated Cu K radiation in this system was found to be approximately 16 times that in the rotatinganode system. Data on x-ray diffraction from crystals of tetragonal form of lysozyme (protein) in this system were found to be of high quality and to be reducible by use of standard crystallographic software.

Catalytic action of β source on x-ray emission from plasma focus

NASA Astrophysics Data System (ADS)

Ahmad, S.; Sadiq, Mehboob; Hussain, S.; Shafiq, M.; Zakaullah, M.; Waheed, A.

2006-01-01

The influence of preionization around the insulator sleeve by a mesh-type β source (Ni6328) for the x-ray emission from a (2.3-3.9 kJ) plasma focus device is investigated. Quantrad Si p-i-n diodes along with suitable filters are employed as time-resolved x-ray detectors and a multipinhole camera with absorption filters is used for time-integrated analysis. X-ray emission in 4π geometry is measured as a function of argon and hydrogen gas filling pressures with and without β source at different charging voltages. It is found that the pressure range for the x-ray emission is broadened, x-ray emission is enhanced, and shot to shot reproducibility is improved with the β source. With argon, the CuKα emission is estimated to be 27.14 J with an efficiency of 0.7% for β source and 21.5 J with an efficiency of 0.55% without β source. The maximum x-ray yield in 4π geometry is found to be about 68.90 J with an efficiency of 1.8% for β source and 54.58 J with an efficiency of 1.4% without β source. With hydrogen, CuKα emission is 11.82 J with an efficiency of 0.32% for β source and 10.07 J with an efficiency of 0.27% without β source. The maximum x-ray yield in 4π geometry is found to be 30.20 J with an efficiency of 0.77% for β source and 25.58 J with an efficiency of 0.6% without β source. The x-ray emission with Pb insert at the anode tip without β source is also investigated and found to be reproducible and significantly high. The maximum x-ray yield is estimated to be 46.6 J in 4π geometry with an efficiency of 1.4% at 23 kV charging voltage. However, degradation of x-ray yield is observed when charging voltage exceeds 23 kV for Pb insert. From pinhole images it is observed that the x-ray emission due to the bombardment of electrons at the anode tip is dominant in both with and without β source.

A high resolution gas scintillation proportional counter for studying low energy cosmic X-ray sources

NASA Technical Reports Server (NTRS)

Hamilton, T. T.; Hailey, C. J.; Ku, W. H.-M.; Novick, R.

1980-01-01

In recent years much effort has been devoted to the development of large area gas scintillation proportional counters (GSPCs) suitable for use in X-ray astronomy. The paper deals with a low-energy GSPC for use in detecting sub-keV X-rays from cosmic sources. This instrument has a measured energy resolution of 85 eV (FWHM) at 149 eV over a sensitive area of 5 sq cm. The development of imaging capability for this instrument is discussed. Tests are performed on the feasibility of using an arrangement of several phototubes placed adjacent to one another to determine event locations in a large flat counter. A simple prototype has been constructed and successfully operated.

Helios-2 Vela-Ariel-5 gamma-ray burst source position

NASA Technical Reports Server (NTRS)

Cline, T. L.; Trainor, J. H.; Desai, U. D.; Klebesadel, R. W.; Ricketts, M.; Heluken, H.

1979-01-01

The gamma-ray burst of 28 January 1976, one of 18 events thus far detected in interplanetary space with Helios-2, was also observed with the Vela-5A, -6A and the Ariel-5 satellites. A small source field is obtained from the intersection of the region derived from the observed time delays between Helios-2 and Vela-5A and -6A with the source region independently found with the Ariel-5 X-ray detector. This area contains neither any steady X-ray source as scanned by HEAO-A nor any previously catalogued X-ray, radio or infrared sources, X-ray transients, quasars, seyferts, globular clusters, flare stars, pulsars, white dwarfs or high energy gamma-ray sources. The region is however, within the source field of a gamma-ray transient observed in 1974, which exhibited nuclear gamma-ray line structure.

Study of X-ray transients with Scanning Sky Monitor (SSM) onboard AstroSat

NASA Astrophysics Data System (ADS)

Ramadevi, M. C.; Ravishankar, B. T.; Sarwade, Abhilash R.; Vaishali, S.; Iyer, Nirmal Kumar; Nandi, Anuj; Girish, V.; Agarwal, Vivek Kumar; Baby, Blessy Elizabeth; Hasan, Mohammed; Seetha, S.; Bhattacharya, Dipankar

2018-02-01

Scanning Sky Monitor (SSM) onboard AstroSat is an X-ray sky monitor in the energy range 2.5-10 keV. SSM scans the sky for X-ray transient sources in this energy range of interest. If an X-ray transient source is detected in outburst by SSM, the information will be provided to the astronomical community for follow-up observations to do a detailed study of the source in various other bands. SSM instrument, since its power-ON in orbit, has observed a number of X-ray sources. This paper discusses observations of few X-ray transients by SSM. The flux reported by SSM for few sources during its Performance Verification phase (PV phase) is studied and the results are discussed.

SEARCHING FOR NEW {gamma}-RAY BLAZAR CANDIDATES IN THE THIRD PALERMO BAT HARD X-RAY CATALOG WITH WISE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maselli, A.; Cusumano, G.; La Parola, V.

We searched for {gamma}-ray blazar candidates among the 382 unidentified hard X-ray sources of the third Palermo BAT Catalog (3PBC) obtained from the analysis of 66 months of Swift Burst Alert Telescope (BAT) survey data and listing 1586 sources. We adopted a recently developed association method based on the peculiar infrared colors that characterize the {gamma}-ray blazars included in the second catalog of active galactic nuclei detected by the Fermi Large Area Telescope. We used this method exploiting the data of the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) to establish correspondences between unidentified 3PBC sources andmore » WISE {gamma}-ray blazar candidates located within the BAT positional uncertainty region at a 99% confidence level. We obtained a preliminary list of candidates for which we analyzed all the available data in the Swift archive to complement the information in the literature and in the radio, infrared, and optical catalogs with the information on their optical-UV and soft X-ray emission. Requiring the presence of radio and soft X-ray counterparts consistent with the infrared positions of the selected WISE sources, as well as a blazar-like radio morphology, we finally obtained a list of 24 {gamma}-ray blazar candidates.« less

The Discovery of a Second Luminous Low Mass X-Ray Binary System in the Globular Cluster M15

NASA Technical Reports Server (NTRS)

White, Nicholas E.; Angelini, Lorella

2001-01-01

Using the Chandra X-ray Observatory we have discovered a second bright X-ray source in the globular cluster M15 that is 2.7" to the west of AC211, the previously known low mass X-ray binary (LMXB) in this system. Prior to the 0.5" imaging capability of Chandra this second source could not have been resolved from AC211. The luminosity and spectrum of this new source, which we call M15-X2, are consistent with it also being a LMXB system. This is the first time that two LMXBs have been seen to be simultaneously active in a globular cluster. The new source, M15-X2, is coincident with a 18th U magnitude very blue star. The discovery of a second LMXB in M15 clears up a long standing puzzle where the X-ray and optical properties of AC211 appear consistent with the central source being hidden behind an accretion disk corona, and yet also showed a luminous X-ray burst suggesting the neutron star is directly visible. This discovery suggests instead that the X-ray burst did not come from AC211, but rather from the newly discovered X-ray source. We discuss the implications of this discovery for X-ray observations of globular clusters in nearby galaxies.

Building a Unified Computational Model for the Resonant X-Ray Scattering of Strongly Correlated Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansil, Arun

2016-12-01

Basic-Energy Sciences of the Department of Energy (BES/DOE) has made large investments in x-ray sources in the U.S. (NSLS-II, LCLS, NGLS, ALS, APS) as powerful enabling tools for opening up unprecedented new opportunities for exploring properties of matter at various length and time scales. The coming online of the pulsed photon source literally allows us to see and follow the dynamics of processes in materials at their natural timescales. There is an urgent need therefore to develop theoretical methodologies and computational models for understanding how x-rays interact with matter and the related spectroscopies of materials. The present project addressed aspectsmore » of this grand challenge of X-ray science. In particular, our Collaborative Research Team (CRT) focused on understanding and modeling of elastic and inelastic resonant X-ray scattering processes. We worked to unify the three different computational approaches currently used for modeling X-ray scattering—density functional theory, dynamical mean-field theory, and small-cluster exact diagonalization—to achieve a more realistic material-specific picture of the interaction between X-rays and complex matter. To achieve a convergence in the interpretation and to maximize complementary aspects of different theoretical methods, we concentrated on the cuprates, where most experiments have been performed. Our team included both US and international researchers, and it fostered new collaborations between researchers currently working with different approaches. In addition, we developed close relationships with experimental groups working in the area at various synchrotron facilities in the US. Our CRT thus helped toward enabling the US to assume a leadership role in the theoretical development of the field, and to create a global network and community of scholars dedicated to X-ray scattering research.« less

Dual crystal x-ray spectrometer at 1.8 keV for high repetition-rate single-photon counting spectroscopy experiments

DOE PAGES

Gamboa, E. J.; Bachmann, B.; Kraus, D.; ...

2016-08-01

The recent development of high-repetition rate x-ray free electron lasers (FEL), makes it possible to perform x-ray scattering and emission spectroscopy measurements from thin foils or gasses heated to high-energy density conditions by integrating over many experimental shots. Since the expected signal may be weaker than the typical CCD readout noise over the region-of-interest, it is critical to the success of this approach to use a detector with high-energy resolution so that single x-ray photons may be isolated. We describe a dual channel x-ray spectrometer developed for the Atomic and Molecular Optics endstation at the Linac Coherent Light Source (LCLS)more » for x-ray spectroscopy near the K-edge of aluminum. The spectrometer is based on a pair of curved PET (002) crystals coupled to a single pnCCD detector which simultaneously measures x-ray scattering and emission in the forward and backward directions. Furthermore, the signals from single x-ray photons are accumulated permitting continuous single-shot acquisition at 120 Hz.« less

Semiconductor and thermoluminescent dosimetry of pulsed soft X ray plasma sources.

PubMed

Krása, J; Cejnarová, A; Juha, L; Ryć, L; Scholz, M; Kubes, P

2002-01-01

A multichannel detection system having a dynamic range of approximately 1 x 10(-9) Gy --20 Gy was developed with the use of commercially produced Si-photodiodes and TLDs for accurate measurement of X ray energy emitted from plasma-focus facility and from laser-produced plasmas. The proof of linearity of the employed detectors accomplished by a comparison of their responses to a broad band spectrum of X rays emitted from plasmas, is reported. It is demonstrated that TLDs irradiated with no protective filter show an incorrect response due to overloading in the sub-keV range and repopulation of dosimetric peaks induced by the UV radiation. The measurement of the power of undesirable secondary X ray sources driven by the primary plasma inside the interaction chamber was performed on the basis of analysis of space dependence of X ray intensity with respect to the assumed r(-2) decrease in the intensity far away from the plasma.

High energy X-ray observations of COS-B gamma-ray sources from OSO-8

NASA Technical Reports Server (NTRS)

Dolan, J. F.; Crannell, C. J.; Dennis, B. R.; Frost, K. J.; Orwig, L. E.; Caraveo, P. A.

1985-01-01

During the three years between satellite launch in June 1975 and turn-off in October 1978, the high energy X-ray spectrometer on board OSO-8 observed nearly all of the COS-B gamma-ray source positions given in the 2CG catalog (Swanenburg et al., 1981). An X-ray source was detected at energies above 20 keV at the 6-sigma level of significance in the gamma-ray error box containing 2CG342 - 02 and at the 3-sigma level of significance in the error boxes containing 2CG065 + 00, 2CG195 + 04, and 2CG311 - 01. No definite association between the X-ray and gamma-ray sources can be made from these data alone. Upper limits are given for the 2CG sources from which no X-ray flux was detected above 20 keV.

Compton tomography system

DOEpatents

Grubsky, Victor; Romanoov, Volodymyr; Shoemaker, Keith; Patton, Edward Matthew; Jannson, Tomasz

2016-02-02

A Compton tomography system comprises an x-ray source configured to produce a planar x-ray beam. The beam irradiates a slice of an object to be imaged, producing Compton-scattered x-rays. The Compton-scattered x-rays are imaged by an x-ray camera. Translation of the object with respect to the source and camera or vice versa allows three-dimensional object imaging.

The MIT HEDP Accelerator Facility for Diagnostic Development for OMEGA, Z, and the NIF

NASA Astrophysics Data System (ADS)

Parker, C. E.; Gatu Johnson, M.; Birkel, A.; Kabadi, N. V.; Lahmann, B.; Milanese, L. M.; Simpson, R. A.; Sio, H.; Sutcliffe, G. D.; Wink, C.; Frenje, J. A.; Li, C. K.; Seguin, F. H.; Petrasso, R. D.; Leeper, R.; Ruiz, C. L.; Sangster, T. C.

2016-10-01

The MIT HEDP Accelerator Facility utilizes a 135-keV linear electrostatic ion accelerator, DT and DD neutron sources, and two x-ray sources for development and characterization of nuclear diagnostics for OMEGA, Z, and the NIF. The accelerator generates DD and D3He fusion products through the acceleration of D+ ions onto a 3He-doped Erbium-Deuteride target. Accurately characterized fusion product rates of around 106 s-1 are routinely achieved. The DT and DD neutron sources generate up to 6x108, and 1x107 neutrons/s, respectively. One x-ray generator is a thick-target W source with a peak energy of 225 keV and a maximum dose rate of 12 Gy/min; the other uses Cu, Mo, or Ti elemental tubes to generate x-rays with a maximum energy of 40 keV. Diagnostics developed and calibrated at this facility include CR-39-based charged-particle spectrometers, neutron detectors, and the particle Time-Of-Flight (pTOF) and Magnetic PTOF CVD-diamond-based bang time detectors. The accelerator is also a valuable hands-on tool for graduate and undergraduate education at MIT. This work was supported in part by the U.S. DoE, SNL, LLE and LLNL.

X-ray lithography source

DOEpatents

Piestrup, M.A.; Boyers, D.G.; Pincus, C.

1991-12-31

A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.

Miniature x-ray source

DOEpatents

Trebes, James E.; Stone, Gary F.; Bell, Perry M.; Robinson, Ronald B.; Chornenky, Victor I.

2002-01-01

A miniature x-ray source capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature x-ray source comprises a compact vacuum tube assembly containing a cathode, an anode, a high voltage feedthru for delivering high voltage to the anode, a getter for maintaining high vacuum, a connection for an initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is highly x-ray transparent and made, for example, from boron nitride. The compact size and potential for remote operation allows the x-ray source, for example, to be placed adjacent to a material sample undergoing analysis or in proximity to the region to be treated for medical applications.

Exotic X-ray Sources from Intermediate Energy Electron Beams

NASA Astrophysics Data System (ADS)

Chouffani, K.; Wells, D.; Harmon, F.; Jones, J. L.; Lancaster, G.

2003-08-01

High intensity x-ray beams are used in a wide variety of applications in solid-state physics, medicine, biology and material sciences. Synchrotron radiation (SR) is currently the primary, high-quality x-ray source that satisfies both brilliance and tunability. The high cost, large size and low x-ray energies of SR facilities, however, are serious limitations. Alternatively, "novel" x-ray sources are now possible due to new small linear accelerator (LINAC) technology, such as improved beam emittance, low background, sub-Picosecond beam pulses, high beam stability and higher repetition rate. These sources all stem from processes that produce Radiation from relativistic Electron beams in (crystalline) Periodic Structures (REPS), or the periodic "structure" of laser light. REPS x-ray sources are serious candidates for bright, compact, portable, monochromatic, and tunable x-ray sources with varying degrees of polarization and coherence. Despite the discovery and early research into these sources over the past 25 years, these sources are still in their infancy. Experimental and theoretical research are still urgently needed to answer fundamental questions about the practical and ultimate limits of their brightness, mono-chromaticity etc. We present experimental results and theoretical comparisons for three exotic REPS sources. These are Laser-Compton Scattering (LCS), Channeling Radiation (CR) and Parametric X-Radiation (PXR).

VizieR Online Data Catalog: ChaMP X-ray point source catalog (Kim+, 2007)

NASA Astrophysics Data System (ADS)

Kim, M.; Kim, D.-W.; Wilkes, B. J.; Green, P. J.; Kim, E.; Anderson, C. S.; Barkhouse, W. A.; Evans, N. R.; Ivezic, Z.; Karovska, M.; Kashyap, V. L.; Lee, M. G.; Maksym, P.; Mossman, A. E.; Silverman, J. D.; Tananbaum, H. D.

2009-01-01

We present the Chandra Multiwavelength Project (ChaMP) X-ray point source catalog with ~6800 X-ray sources detected in 149 Chandra observations covering ~10deg2. The full ChaMP catalog sample is 7 times larger than the initial published ChaMP catalog. The exposure time of the fields in our sample ranges from 0.9 to 124ks, corresponding to a deepest X-ray flux limit of f0.5-8.0=9x10-16ergs/cm2/s. The ChaMP X-ray data have been uniformly reduced and analyzed with ChaMP-specific pipelines and then carefully validated by visual inspection. The ChaMP catalog includes X-ray photometric data in eight different energy bands as well as X-ray spectral hardness ratios and colors. To best utilize the ChaMP catalog, we also present the source reliability, detection probability, and positional uncertainty. (10 data files).

Simulating the X-Ray Image Contrast to Set-Up Techniques with Desired Flaw Detectability

NASA Technical Reports Server (NTRS)

Koshti, Ajay M.

2015-01-01

The paper provides simulation data of previous work by the author in developing a model for estimating detectability of crack-like flaws in radiography. The methodology is being developed to help in implementation of NASA Special x-ray radiography qualification, but is generically applicable to radiography. The paper describes a method for characterizing X-ray detector resolution for crack detection. Applicability of ASTM E 2737 resolution requirements to the model are also discussed. The paper describes a model for simulating the detector resolution. A computer calculator application, discussed here, also performs predicted contrast and signal-to-noise ratio calculations. Results of various simulation runs in calculating x-ray flaw size parameter and image contrast for varying input parameters such as crack depth, crack width, part thickness, x-ray angle, part-to-detector distance, part-to-source distance, source sizes, and detector sensitivity and resolution are given as 3D surfaces. These results demonstrate effect of the input parameters on the flaw size parameter and the simulated image contrast of the crack. These simulations demonstrate utility of the flaw size parameter model in setting up x-ray techniques that provide desired flaw detectability in radiography. The method is applicable to film radiography, computed radiography, and digital radiography.

Observations of low luminosity X-ray sources in Vela-Puppis

NASA Technical Reports Server (NTRS)

Pravdo, S. H.; Becker, R. H.; Boldt, E. A.; Holt, S. S.; Erlemitsos, P. J.; Swank, J. H.

1978-01-01

Results of a study of the X-ray emission from a small portion of the galactic plane near galactic longitude 260 deg are presented. This region contains at least six low luminosity X-ray sources within approximately 10 deg. of PSRO833-45, which is near the center of the Gum Nebula. The X-ray source associated with the Vela pulsar, 4U0833-45, is observed at twice its 4U catalogue intensity. The lack of X-ray pulsations at the pulsar period, the non thermal power law spectrum, and models of the X-ray come from an extended source approximately 1 deg in radius. The observation of a high temperature spectrum in a field of view containing only Puppis A among known sources has led to the discovery of a new OSO-8 source, OSO752-39. Other spectra from this region are discussed.

Phase-sensitive X-ray imager

DOEpatents

Baker, Kevin Louis

2013-01-08

X-ray phase sensitive wave-front sensor techniques are detailed that are capable of measuring the entire two-dimensional x-ray electric field, both the amplitude and phase, with a single measurement. These Hartmann sensing and 2-D Shear interferometry wave-front sensors do not require a temporally coherent source and are therefore compatible with x-ray tubes and also with laser-produced or x-pinch x-ray sources.

ID16B: a hard X-ray nanoprobe beamline at the ESRF for nano-analysis

PubMed Central

Martínez-Criado, Gema; Villanova, Julie; Tucoulou, Rémi; Salomon, Damien; Suuronen, Jussi-Petteri; Labouré, Sylvain; Guilloud, Cyril; Valls, Valentin; Barrett, Raymond; Gagliardini, Eric; Dabin, Yves; Baker, Robert; Bohic, Sylvain; Cohen, Cédric; Morse, John

2016-01-01

Within the framework of the ESRF Phase I Upgrade Programme, a new state-of-the-art synchrotron beamline ID16B has been recently developed for hard X-ray nano-analysis. The construction of ID16B was driven by research areas with major scientific and societal impact such as nanotechnology, earth and environmental sciences, and bio-medical research. Based on a canted undulator source, this long beamline provides hard X-ray nanobeams optimized mainly for spectroscopic applications, including the combination of X-ray fluorescence, X-ray diffraction, X-ray excited optical luminescence, X-ray absorption spectroscopy and 2D/3D X-ray imaging techniques. Its end-station re-uses part of the apparatus of the earlier ID22 beamline, while improving and enlarging the spectroscopic capabilities: for example, the experimental arrangement offers improved lateral spatial resolution (∼50 nm), a larger and more flexible capability for in situ experiments, and monochromatic nanobeams tunable over a wider energy range which now includes the hard X-ray regime (5–70 keV). This paper describes the characteristics of this new facility, short-term technical developments and the first scientific results. PMID:26698084

MIT modular x-ray source systems for the study of plasma diagnostics

NASA Astrophysics Data System (ADS)

Coleman, J. W.; Wenzel, K. W.; Petrasso, R. D.; Lo, D. H.; Li, C. K.; Lierzer, J. R.; Wei, T.

1992-10-01

Two new x-ray source systems are now on line at our facility. Each provides an e-beam to 25 kV. Targets are interchangeable between machines, and four x-ray detectors may be used simultaneously with a target. The gridded e-gun of the RACEHORSE system gives a 0.5-1.0-cm pulsable spot on target. The nongridded e-gun of the SCORPION system provides a 0.3-mm or smaller dc microspot on target. RACEHORSE is being used to study and characterize type-II diamond photoconductors for use in diagnosing plasmas, while SCORPION is being used to develop a slitless spectrograph using photographic film. Source design details and some RACEHORSE results are presented.

ROSAT X-ray sources embedded in the rho Ophiuchi cloud core

NASA Astrophysics Data System (ADS)

Casanova, Sophie; Montmerle, Thierry; Feigelson, Eric D.; Andre, Philippe

1995-02-01

We present a deep ROSAT Position Sensitive Proportional Counter (PSPC) image of the central region of the rho Oph star-forming region. The selected area, about 35 x 35 arcmins in size, is rich with dense molecular cores and young stellar objects (YSOs). Fifty-five reliable X-ray sources are detected (and up to 50 more candidates may be present) above approximately 1 keV,, doubling the number of Einstein sources in this area. These sources are cross-identified with an updated list of 88 YSOs associated with the rho Oph cloud core. A third of the reliable X-ray sources do not have optical counterparts on photographic plates. Most can be cross-identified wth Class II and Class III infrared (IR) sources, which are embedded T Tauri stars, but three reliable X-ray sources and up to seven candidate sources are tentatively identified with Class I protostars. Eighteen reliable, and up to 20 candidate, X-ray sources are probably new cloud members. The overall detection rate of the bona fide cloud population is very high (73% for the Class II and Class III objects). The spatial distribution of the X-ray sources closely follows that of the moleclar gas. The visual extinctions Av estimated from near-IR data) of the ROSAT sources can be as high as 50 or more, confirming that most are embedded in the cloud core and are presumably very young. Using bolometric luminosities Lbol estimated from J-magnitudes a tight correlation between Lx and Lbol is found, similar to that seen for older T Tauri stars in the Cha I cloud: Lx approximately 10-4 Lbol. A general relation Lxproportional to LbolLj seems to apply to all T Tauri-like YSOs. The near equality of the extintion in the IR J band and in the keV X-ray rage implies that this relation is valid for the detected fluxes as well as for the dereddened fluxes. The X-ray luminosity function of the embedded sourced in rho Oph spans a range of Lx approximately 1028.5 to approximately equal to or greater than 1031.5 ergs/s and is statistically indistinguishable from that of X-ray-detected visile T Tauri stars. We estimate a total X-ray luminosity Lx, Oph approximately equal to or greater than 6 x 10 32 ergs/s from approximately equal to 200 X-ray sources in the cloud core, down to Lbol approximately 0.1 solar luminosity or Mstar approximately 0.3 solar mass. We discuss several consequences of in situ irradiation of molecular clouds by X-rays from embedded YSOs. These X-rays must partially ionize the inner regions of circumstellar disk coronae, possibly playing an important role in coupling magnetic ionize the fields and wind or bipolar outflows. Photon-stimulated deportion of large molecules by YSO X-rays may be partly responsible for the bright 12 micrometer halos seen in some molecular clouds.

An X-ray Investigation of the NGC 346 Field in the SMC (2): The Field Population

NASA Technical Reports Server (NTRS)

Naze, Y.; Hartwell, J. M.; Stevens, I. R.; Manfroid, J.; Marchenko, S.; Corcoran, M. F.; Moffat, A. F. J.; Skalkowski, G.

2003-01-01

We present results from a Chandra observation of the NGC 346 cluster, which is the ionizing source of N66, the most luminous HII region and the largest star formation region in the SMC. In the first part of this investigation, we have analysed the X-ray properties of the cluster itself and the remarkable star HD 5980. But the field contains additional objects of interest. In total, 79 X-ray point sources were detected in the Chandra observation: this is more than five times the number of sources detected by previous X-ray surveys. We investigate here their characteristics in detail. The sources possess rather high hardness ratios, and their cumulative luminosity function is steeper than that for the rest of the SMC at higher .luminosities. Their absorption columns suggest that most of the sources belong to NGC346. Using new UBV RI imaging with the ESO 2.2m telescope, we also discovered possible counterparts for 36 of these X-ray sources and estimated a B spectral type for a large number of these counterparts. This tends to suggest that most of the X-ray sources in the field are in fact X-ray binaries. Finally, some objects show X-ray and/or optical variability, with a need for further monitoring.

The second ROSAT All-Sky Survey source catalogue: the deepest X-ray All-Sky Survey before eROSITA

NASA Astrophysics Data System (ADS)

Boller, T.; Freyberg, M.; Truemper, J.

2014-07-01

We present the second ROSAT all-sky survey source catalogue (RASS2, (Boller, Freyberg, Truemper 2014, submitted)). The RASS2 is an extension of the ROSAT Bright Source Catalogue (BSC) and the ROSAT Faint Source Catalogue (FSC). The total number of sources in the second RASS catalogue is 124489. The extensions include (i) the supply of new user data products, i.e., X-ray images, X-ray spectra, and X-ray light curves, (ii) a visual screening of each individual detection, (iii) an improved detection algorithm compared to the SASS II processing. This results into an as most as reliable and as most as complete catalogue of point sources detected during the ROSAT Survey observations. We discuss for the first time the intra-day timing and spectral properties of the second RASS catalogue. We find new highly variable sources and we discuss their timing properties. Power law fits have been applied which allows to determine X-ray fluxes, X-ray absorbing columns, and X-ray photon indices. We give access to the second RASS catalogue and the associated data products via a web-interface to allow the community to perform further scientific exploration. The RASS2 catalogue provides the deepest X-ray All-Sky Survey before eROSITA data will become available.

X-ray laser microscope apparatus

DOEpatents

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

1990-01-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Xiaochao; Kim, Joshua; Laganis, Philip

2011-10-15

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

The Chandra Deep Field-South Survey: 7 Ms Source Catalogs

NASA Technical Reports Server (NTRS)

Luo, B.; Brandt, W. N.; Xue, Y. Q.; Lehmer, B.; Alexander, D. M.; Bauer, F. E.; Vito, F.; Yang, G.; Basu-Zych, A. R.; Comastri, A.;

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carini, Gabriella; Denes, Peter; Gruener, Sol

The Basic Energy Sciences (BES) X-ray and neutron user facilities attract more than 12,000 researchers each year to perform cutting-edge science at these state-of-the-art sources. While impressive breakthroughs in X-ray and neutron sources give us the powerful illumination needed to peer into the nano- to mesoscale world, a stumbling block continues to be the distinct lag in detector development, which is slowing progress toward data collection and analysis. Urgently needed detector improvements would reveal chemical composition and bonding in 3-D and in real time, allow researchers to watch “movies” of essential life processes as they happen, and make much moremore » efficient use of every X-ray and neutron produced by the source The immense scientific potential that will come from better detectors has triggered worldwide activity in this area. Europe in particular has made impressive strides, outpacing the United States on several fronts. Maintaining a vital U.S. leadership in this key research endeavor will require targeted investments in detector R&D and infrastructure. To clarify the gap between detector development and source advances, and to identify opportunities to maximize the scientific impact of BES user facilities, a workshop on Neutron and X-ray Detectors was held August 1-3, 2012, in Gaithersburg, Maryland. Participants from universities, national laboratories, and commercial organizations from the United States and around the globe participated in plenary sessions, breakout groups, and joint open-discussion summary sessions. Sources have become immensely more powerful and are now brighter (more particles focused onto the sample per second) and more precise (higher spatial, spectral, and temporal resolution). To fully utilize these source advances, detectors must become faster, more efficient, and more discriminating. In supporting the mission of today’s cutting-edge neutron and X-ray sources, the workshop identified six detector research challenges (and two computing hurdles that result from the corresponding increase in data volume) for the detector community to overcome in order to realize the full potential of BES neutron and X-ray facilities. Resolving these detector impediments will improve scientific productivity both by enabling new types of experiments, which will expand the scientific breadth at the X-ray and neutron facilities, and by potentially reducing the beam time required for a given experiment. These research priorities are summarized in the table below. Note that multiple, simultaneous detector improvements are often required to take full advantage of brighter sources. High-efficiency hard X-ray sensors: The fraction of incident particles that are actually detected defines detector efficiency. Silicon, the most common direct-detection X-ray sensor material, is (for typical sensor thicknesses) 100% efficient at 8 keV, 25%efficient at 20 keV, and only 3% efficient at 50 keV. Other materials are needed for hard X-rays. Replacement for 3He for neutron detectors: 3He has long been the neutron detection medium of choice because of its high cross section over a wide neutron energy range for the reaction 3He + n —> 3H + 1H + 0.764 MeV. 3He stockpiles are rapidly dwindling, and what is available can be had only at prohibitively high prices. Doped scintillators hold promise as ways to capture neutrons and convert them into light, although work is needed on brighter, more efficient scintillator solutions. Neutron detectors also require advances in speed and resolution. Fast-framing X-ray detectors: Today’s brighter X-ray sources make time-resolved studies possible. For example, hybrid X-ray pixel detectors, initially developed for particle physics, are becoming fairly mature X-ray detectors, with considerable development in Europe. To truly enable time-resolved studies, higher frame rates and dynamic range are required, and smaller pixel sizes are desirable. High-speed spectroscopic X-ray detectors: Improvements in the readout speed and energy resolution of X-ray detectors are essential to enable chemically sensitive microscopies. Advances would make it possible to take images with simultaneous spatial and chemical information. Very high-energy-resolution X-ray detectors: The energy resolution of semiconductor detectors, while suitable for a wide range of applications, is far less than what can be achieved with X-ray optics. A direct detector that could rival the energy resolution of optics could dramatically improve the efficiency of a multitude of experiments, as experiments are often repeated at a number of different energies. Very high-energy-resolution detectors could make these experiments parallel, rather than serial. Low-background, high-spatial-resolution neutron detectors: Low-background detectors would significantly improve experiments that probe excitations (phonons, spin excitations, rotation, and diffusion in polymers and molecular substances, etc.) in condensed matter. Improved spatial resolution would greatly benefit radiography, tomography, phase-contrast imaging, and holography. Improved acquisition and visualization tools: In the past, with the limited variety of slow detectors, it was straightforward to visualize data as it was being acquired (and adjust experimental conditions accordingly) to create a compact data set that the user could easily transport. As detector complexity and data rates explode, this becomes much more challenging. Three goals were identified as important for coping with the growing data volume from high-speed detectors: Facilitate better algorithm development. In particular, algorithms that can minimize the quantity of data stored. Improve community-driven mechanisms to reduce data protocols and enhance quantitative, interactive visualization tools. Develop and distribute community-developed, detector-specific simulation tools. Aim for parallelization to take advantage of high-performance analysis platforms. Improved analysis work flows: Standardize the format of metadata that accompanies detector data and describes the experimental setup and conditions. Develop a standardized user interface and software framework for analysis and data management. The diversity of detector improvements required is necessarily as broad as the range of scientific experimentation at BES facilities. This workshop identified a variety of avenues by which detector R&D can enable enhanced science at BES facilities. The Research Directions listed above will be addressed by focused R&D and detector engineering, both of which require specialized infrastructure and skills. While U.S. leadership in neutron and X-ray detectors lags behind other countries in several areas, significant talent exists across the complex. A forum of technical experts, facilities management, and BES could be a venue to provide further definition.« less

Laser-wakefield accelerators as hard x-ray sources for 3D medical imaging of human bone

PubMed Central

Cole, J. M.; Wood, J. C.; Lopes, N. C.; Poder, K.; Abel, R. L.; Alatabi, S.; Bryant, J. S. J.; Jin, A.; Kneip, S.; Mecseki, K.; Symes, D. R.; Mangles, S. P. D.; Najmudin, Z.

2015-01-01

A bright μm-sized source of hard synchrotron x-rays (critical energy Ecrit > 30 keV) based on the betatron oscillations of laser wakefield accelerated electrons has been developed. The potential of this source for medical imaging was demonstrated by performing micro-computed tomography of a human femoral trabecular bone sample, allowing full 3D reconstruction to a resolution below 50 μm. The use of a 1 cm long wakefield accelerator means that the length of the beamline (excluding the laser) is dominated by the x-ray imaging distances rather than the electron acceleration distances. The source possesses high peak brightness, which allows each image to be recorded with a single exposure and reduces the time required for a full tomographic scan. These properties make this an interesting laboratory source for many tomographic imaging applications. PMID:26283308

The hard x-ray imager onboard IXO

NASA Astrophysics Data System (ADS)

Nakazawa, Kazuhiro; Takahashi, Tadayuki; Limousin, Olivier; Kokubun, Motohide; Watanabe, Shin; Laurent, Philippe; Arnaud, Monique; Tajima, Hiroyasu

2010-07-01

The Hard X-ray Imager (HXI) is one of the instruments onboard International X-ray Observatory (IXO), to be launched into orbit in 2020s. It covers the energy band of 10-40 keV, providing imaging-spectroscopy with a field of view of 8 x 8 arcmin2. The HXI is attached beneath the Wide Field Imager (WFI) covering 0.1-15 keV. Combined with the super-mirror coating on the mirror assembly, this configuration provides observation of X-ray source in wide energy band (0.1-40.0 keV) simultaneously, which is especially important for varying sources. The HXI sensor part consists of the semiconductor imaging spectrometer, using Si in the medium energy detector and CdTe in the high energy detector as its material, and an active shield covering its back to reduce background in orbit. The HXI technology is based on those of the Japanese-lead new generation X-ray observatory ASTRO-H, and partly from those developed for Simbol-X. Therefore, the technological development is in good progress. In the IXO mission, HXI will provide a major assets to identify the nature of the object by penetrating into thick absorbing materials and determined the inherent spectral shape in the energy band well above the structure around Fe-K lines and edges.

An update on carbon nanotube-enabled X-ray sources for biomedical imaging.

PubMed

Puett, Connor; Inscoe, Christina; Hartman, Allison; Calliste, Jabari; Franceschi, Dora K; Lu, Jianping; Zhou, Otto; Lee, Yueh Z

2018-01-01

A new imaging technology has emerged that uses carbon nanotubes (CNT) as the electron emitter (cathode) for the X-ray tube. Since the performance of the CNT cathode is controlled by simple voltage manipulation, CNT-enabled X-ray sources are ideal for the repetitive imaging steps needed to capture three-dimensional information. As such, they have allowed the development of a gated micro-computed tomography (CT) scanner for small animal research as well as stationary tomosynthesis, an experimental technology for large field-of-view human imaging. The small animal CT can acquire images at specific points in the respiratory and cardiac cycles. Longitudinal imaging therefore becomes possible and has been applied to many research questions, ranging from tumor response to the noninvasive assessment of cardiac output. Digital tomosynthesis (DT) is a low-dose and low-cost human imaging tool that captures some depth information. Known as three-dimensional mammography, DT is now used clinically for breast imaging. However, the resolution of currently-approved DT is limited by the need to swing the X-ray source through space to collect a series of projection views. An array of fixed and distributed CNT-enabled sources provides the solution and has been used to construct stationary DT devices for breast, lung, and dental imaging. To date, over 100 patients have been imaged on Institutional Review Board-approved study protocols. Early experience is promising, showing an excellent conspicuity of soft-tissue features, while also highlighting technical and post-acquisition processing limitations that are guiding continued research and development. Additionally, CNT-enabled sources are being tested in miniature X-ray tubes that are capable of generating adequate photon energies and tube currents for clinical imaging. Although there are many potential applications for these small field-of-view devices, initial experience has been with an X-ray source that can be inserted into the mouth for dental imaging. Conceived less than 20 years ago, CNT-enabled X-ray sources are now being manufactured on a commercial scale and are powering both research tools and experimental human imaging devices. WIREs Nanomed Nanobiotechnol 2018, 10:e1475. doi: 10.1002/wnan.1475 This article is categorized under: Diagnostic Tools > Diagnostic Nanodevices Diagnostic Tools > In Vivo Nanodiagnostics and Imaging. © 2017 Wiley Periodicals, Inc.

Intense X-ray and EUV light source

DOEpatents

Coleman, Joshua; Ekdahl, Carl; Oertel, John

2017-06-20

An intense X-ray or EUV light source may be driven by the Smith-Purcell effect. The intense light source may utilize intense electron beams and Bragg crystals. This may allow the intense light source to range from the extreme UV range up to the hard X-ray range.

Development of Standard Samples for on-board Calibration of a New Planetary X-Ray Fluorescence Spectrometer

NASA Astrophysics Data System (ADS)

Dreißigacker, Anne; Köhler, Eberhard; Fabel, Oliver; van Gasselt, Stephan

2014-05-01

At the Planetary Sciences and Remote Sensing research group at Freie Universität Berlin an SCD-based X-Ray Fluorescence Spectrometer is being developed to be employed on planetary orbiters to conduct direct, passive energy-dispersive x-ray fluorescence measurements of planetary surfaces through measuring the emitted X-Ray fluorescence induced by solar x-rays and high energy particles. Because the Sun is a highly variable radiation source, the intensity of solar X-Ray radiation has to be monitored constantly to allow for comparison and signal calibration of X-Ray radiation from lunar surface materials. Measurements are obtained by indirectly monitoring incident solar x-rays emitted from a calibration sample. This has the additional advantage of minimizing the risk of detector overload and damage during extreme solar events such as high-energy solar flares and particle storms as only the sample targets receive the higher radiation load directly (while the monitor is never directly pointing towards the Sun). Quantitative data are being obtained and can be subsequently analysed through synchronous measurement of fluorescence of the Moon's surface by the XRF-S main instrument and the emitted x-ray fluorescence of calibration samples by the XRF-S-ISM (Indirect Solar Monitor). We are currently developing requirements for 3 sample tiles for onboard correction and calibration of XRF-S, each with an area of 3-9 cm2 and a maximum weight of 45 g. This includes development of design concepts, determination of techniques for sample manufacturing, manufacturing and testing of prototypes and statistical analysis of measurement characteristics and quantification of error sources for the advanced prototypes and final samples. Apart from using natural rock samples as calibration sample, we are currently investigating techniques for sample manufacturing including laser sintering of rock-glass on metals, SiO2-stabilized mineral-powders, or artificial volcanic glass. High precision measurements of the chemical composition of the final samples (EPMA, various energy-dispersive XRF) will serve as calibration standard for XRF-S. Development is funded by the German Aerospace Agency under grant 50 JR 1303.

Probing the X-Ray Binary Populations of the Ring Galaxy NGC 1291

NASA Technical Reports Server (NTRS)

Luo, B.; Fabbiano, G.; Fragos, T.; Kim, D. W.; Belczynski, K.; Brassington, N. J.; Pellegrini, S.; Tzanavaris, P.; Wang, J.; Zezas, A.

2012-01-01

We present Chandra studies of the X-ray binary (XRB) populations in the bulge and ring regions of the ring galaxy NGC 1291. We detect 169 X-ray point sources in the galaxy, 75 in the bulge and 71 in the ring, utilizing the four available Chandra observations totaling an effective exposure of 179 ks. We report photometric properties of these sources in a point-source catalog. There are approx. 40% of the bulge sources and approx. 25% of the ring sources showing > 3(sigma) long-term variability in their X-ray count rate. The X-ray colors suggest that a significant fraction of the bulge (approx. 75%) and ring (approx. 65%) sources are likely low-mass X-ray binaries (LMXBs). The spectra of the nuclear source indicate that it is a low-luminosity AGN with moderate obscuration; spectral variability is observed between individual observations. We construct 0.3-8.0 keV X-ray luminosity functions (XLFs) for the bulge and ring XRB populations, taking into account the detection incompleteness and background AGN contamination. We reach 90% completeness limits of approx.1.5 x 10(exp 37) and approx. 2.2 x 10(exp 37) erg/s for the bulge and ring populations, respectively. Both XLFs can be fit with a broken power-law model, and the shapes are consistent with those expected for populations dominated by LMXBs. We perform detailed population synthesis modeling of the XRB populations in NGC 1291 , which suggests that the observed combined XLF is dominated by aD old LMXB population. We compare the bulge and ring XRB populations, and argue that the ring XRBs are associated with a younger stellar population than the bulge sources, based on the relative over-density of X-ray sources in the ring, the generally harder X-ray color of the ring sources, the overabundance of luminous sources in the combined XLF, and the flatter shape of the ring XLF.

Picosecond, tunable, high-brightness hard x-ray inverse Compton source at Duke storage ring

NASA Astrophysics Data System (ADS)

Litvinenko, Vladimir N.; Wu, Ying; Burnham, Bentley; Barnett, Genevieve A.; Madey, John M. J.

1995-09-01

We suggest a state-of-the art x-ray source using a compact electron storage ring with modest energy (less than 1 GeV) and a high power mm-wave as an undulator. A source of this type has x-ray energies and brightness comparable with third generation synchrotron light sources while it can be very compact and fit in a small university or industrial laboratory or hospital. We propose to operate an isochronous mm-wave FEL and a hard x-ray inverse Compton source at the Duke storage ring to test this concept. Resonant FEL conditions for the mm- wave will be provided by the off-axis interaction with an electromagnetic wave. A special optical resonator with holes for the e-beam is proposed for pumping a hard x-ray inverse Compton source with very high brightness. Simulation results of mm-wave FEL operation of the Duke storage ring are discussed. Expected performance of mm-wave FEL and hard x-ray inverse Compton source are presented.

Chandra Observation of the X-ray Source Population of NGC 6946

NASA Technical Reports Server (NTRS)

Holt, S. S.; Schlegel, E. M.; Hwang, U.; Petre, R.

2003-01-01

We present the results of a study of discrete X-ray sources in NGC 6946 using a deep Chandra ACIS observation. Based on the slope of the log N-log S distribution and the general correlation of sources with the spiral arms, we infer that the overall discrete source sample in NGC 6946 is dominated by high mass X-ray binaries, in contrast to the source distributions in M31 and the Milky Way. This is consistent with the higher star formation rate in NGC 6946 than in those galaxies. We find that the strong X-ray sources in the region of the galactic center do not correlate in detail with images of the region in the near-IR, although one of them may be coincident with the galactic center. The non-central ultra-luminous X-ray source in NGC 6946, previously identified with a supernova remnant, has an X-ray spectrum and luminosity that is inconsistent with either a traditional pulsar wind nebula or a blast wave remnant.

Temporal characteristic analysis of laser-modulated pulsed X-ray source for space X-ray communication

NASA Astrophysics Data System (ADS)

Hang, Shuang; Liu, Yunpeng; Li, Huan; Tang, Xiaobin; Chen, Da

2018-04-01

X-ray communication (XCOM) is a new communication type and is expected to realize high-speed data transmission in some special communication scenarios, such as deep space communication and blackout communication. This study proposes a high-speed modulated X-ray source scheme based on the laser-to-X-ray conversion. The temporal characteristics of the essential components of the proposed laser-modulated pulsed X-ray source (LMPXS) were analyzed to evaluate its pulse emission performance. Results show that the LMPXS can provide a maximum modulation rate up to 100 Mbps which is expected to significantly improve the data rate of XCOM.

New insights into the X-ray properties of nearby barred spiral galaxy NGC 1672

NASA Astrophysics Data System (ADS)

Jenkins, L. P.; Brnadt, W. N.; Colbert, E. J. M.; Levan, A. J.; Roberts, T. P.; Ward, M. J.; Zezas, A.

2008-02-01

We present some preliminary results from new Chandra and XMM-Newton X-ray observations of the nearby barred spiral galaxy NGC1672. It shows dramatic nuclear and extra-nuclear star formation activity, including starburst regions located near each end of its strong bar, both of which host ultraluminous X-ray sources (ULXs). With the new high-spatial-resolution Chandra imaging, we show for the first time that NGC1672 possesses a faint ($L(X)~10^39 erg/s), hard central X-ray source surrounded by an X-ray bright circumnuclear starburst ring that dominates the X-ray emission in the region. The central source may represent low-level AGN activity, or alternatively the emission from X-ray binaries associated with star-formation in the nucleus.

A Multi-Wavelength Study of the X-Ray Sources in the NGC 5018

NASA Technical Reports Server (NTRS)

Ghosh, Kajal K.; Swartz, Douglas A.; Tennant, Allyn F.; Wu, Kinwah; Saripalli, Lakshmi

2004-01-01

The E3 giant elliptical galaxy NGC-5018 was observed with the cxo X-ray Observatory's Advanced CCD Imaging Spectrometer for 30-h on 14 April 2001. Results of analysis of these X-ray data as well as of complementary optical, infrared, and radio data are reported. Seven X-ray point sources, including the nucleus, were detected. If they are intrinsic to NGC-5018, then all six non-nuclear sources have luminosities exceeding 10(exp 39)-ergl in the 0.5-8.0-keV energy band; placing them in the class of Ultra- luminous X-ray sources. Comparison of X-ray source positions to archival Hubble Space Telescope/Wide Field Planetary Camera 2 (hst/WFPC2) images reveal four of the six non-nuclear sources are spatially--coincident with bright, M$(sub V)LA -8.6 mag, objects. These four objects have optical magnitudes and (V-I) colors consistent with globular clusters in NGC-5018. However, one of these objects was observed to vary by siml mag in both V and I between observations taken 28 July 1997 and 04 Feb 1999 indicating this source is a background active galactic nucleus (AGN). The nature of the other three optically-bright objects cannot be determined from the available optical data but all have X-ray-to-optical flux ratios consistent with background AGNs. Strong, unpolarized, radio emission has been detected from another of the optically-bright counterparts. It displays an inverted radio spectrum and is the most absorbed of the seven sources in the X-ray band. It, too, is most readily explained as a background AGN, though alternative explanations cannot be ruled out. Extended X-ray emission is detected within a siml5 arcsec radius of the galaxy center at a luminosity of sim lO(exp 40)-ergl in the X-ray band. Its thermal X-ray spectrum (kT sim0.4-keV) and its spatial coincidence with strong H(alpha) emission are consistent with a hot gas origin. The nucleus itself is a weak X-ray source, LA-5 times 10(exp 39)-ergl, but displays a radio spectrum typical of AGN.

Chandra Detects Enigmatic Point X-ray Sources in the Cat's Eye and the Helix Nebulae

NASA Astrophysics Data System (ADS)

Guerrero, M. A.; Gruendl, R. A.; Chu, Y.-H.; Kaler, J. B.; Williams, R. M.

2000-12-01

Central stars of planetary nebulae (PNe) with Teff greater than 100,000 K are expected to emit soft X-rays that peak below 0.1 keV. Chandra ACIS-S observations of the Cat's Eye Nebula (NGC 6543) and the Helix Nebula (NGC 7293) have detected point X-ray sources at their central stars. The point X-ray source at the central star of the Cat's Eye is both unknown previously and unexpected because the stellar temperature is only ~50,000 K. In contrast, the point X-ray source at the central star of the Helix was previously detected by ROSAT and its soft X-ray emission is expected because the stellar temperature is ~100,000 K. However, the Helix X-ray source also shows a harder X-ray component peaking at 0.8 keV that is unexpected and for which Chandra has provided the first high-resolution spectrum for detailed analysis. The spectra of the point X-ray sources in the Cat's Eye and the Helix show line features indicating an origin of thermal plasma emission. The spectrum of the Helix source can be fit by Raymond & Smith's model of plasma emission at ~9*E6 K. The spectrum of the Cat's Eye source has too few counts for a spectral fit, but appears to be consistent with plasma emission at 2-3*E6 K. The X-ray luminosities of both sources are ~5*E29 erg s-1. The observed plasma temperatures are too high for accretion disks around white dwarfs, but they could be ascribed to coronal X-ray emission. While central stars of PNe are not known to have coronae, the observed spectra are consistent with quiescent X-ray emission from dM flare stars. On the other hand, neither the central star of the Helix or the Cat's Eye are known to have a binary companion. It is possible that the X-rays from the Cat's Eye's central star originate from shocks in the stellar wind, but the central star of the Helix does not have a measurable fast stellar wind. This work is supported by the CXC grant number GO0-1004X.

Use of capillary optics as a beam intensifier for a Compton x-ray source.

PubMed

Tompkins, P A; Abreu, C C; Carroll, F E; Xiao, Q F; MacDonald, C A

1994-11-01

The use of Kumakhov capillary optics will significantly enhance the performance of near-monochromatic, Compton backscattered x-ray programs. The Vanderbilt University Medical Free-Electron Laser Center is developing the capability to create these tunable x rays for medical imaging. The present transport has only reflection optics, and the beam is quite large in diameter at the laboratory. Low loss collimation of this beam would allow higher x-ray intensities after transport. This article describes experimental and computer simulation results which predict the expected performance for a multifiber Kumakhov collimator for use in the x-ray beam transport. Estimates from our research are that a multifiber optic formed of individual polycapillary fibers could be used to capture the full 7 mrad of the Vanderbilt x-ray beam and collimate it to a 1-2 mrad divergence with approximately 40%-50% transmission efficiency. This optic should increase the x-ray intensity at the laboratory level by a factor of > or = 5 by decreasing the beam divergence and subsequent spot size. Additionally, analysis of monolithic optics of fused multicapillary fibers predicts an increase in the intensity of the x rays at the laboratory by a factor of 55. These optics can have tapered channels that greatly decrease their exit divergence. This will greatly enhance the capabilities of this unique x-ray source. This article reports the initial results from a collaboration between Vanderbilt, The Center for X-Ray Optics at University at Albany, SUNY, and X-Ray Optical Systems in Albany, NY.

Pile-up corrections in laser-driven pulsed X-ray sources

NASA Astrophysics Data System (ADS)

Hernández, G.; Fernández, F.

2018-06-01

A formalism for treating the pile-up produced in solid-state detectors by laser-driven pulsed X-ray sources has been developed. It allows the direct use of X-ray spectroscopy without artificially decreasing the number of counts in the detector, assuming the duration of a pulse is much shorter than the detector response time and the loss of counts from the energy window of the detector can be modeled or neglected. Experimental application shows that having a small amount of pile-up subsequently corrected improves the signal-to-noise ratio, which would be more beneficial than the strict single-hit condition usually imposed on this detectors.

An X-ray investigation of the unusual supernova remnant CTB 80

NASA Technical Reports Server (NTRS)

Wang, Z. R.; Seward, F. D.

1984-01-01

The X-ray properties of SNR CTB 80 (G68.8 + 2.8) are discussed based on both low- and high-resolution images from the Einstein satellite. The X-ray maps show a point source coinciding with the region of maximum radio emission. Diffuse X-ray emission is evident mainly along the radio lobe extending about 8 arcmin east of the point source and aligned with the projected magnetic field lines. The observed X-ray luminosity is 3.2 x 10 to the 34th ergs/s with 1.0 x 10 to the 3th ergs/s from the point source (assuming a distance of 3 kpc). There is also faint, diffuse, X-ray emission south of the point source, where radio emission is absent. The unusual radio and X-ray morphologies are interpreted as a result of relativistic jets energized by the central object, and the possible association of CTB 80 with SN 1408 as recorded by Chinese observers is discussed.

Radiation predictions and shielding calculations for RITS-6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maenchen, John Eric; O'Malley, John; Kensek, Ronald Patrick

2005-06-01

The mission of Radiographic Integrated Test Stand-6 (RITS-6) facility is to provide the underlying science and technology for pulsed-power-driven flash radiographic X-ray sources for the National Nuclear Security Administration (NNSA). Flash X-ray radiography is a penetrating diagnostic to discern the internal structure in dynamic experiments. Short (~50 nanosecond (ns) duration) bursts of very high intensity Xrays from mm-scale source sizes are required at a variety of voltages to address this mission. RITS-6 was designed and is used to both develop the accelerator technology needed for these experiments and serves as the principal test stand to develop the high intensity electronmore » beam diodes that generate the required X-ray sources. RITS is currently in operation with three induction cavities (RITS-3) with a maximum voltage output of 5.5 MV and is classified as a low hazard non-nuclear facility in accordance with CPR 400.1.1, Chapter 13, Hazards Identification/Analysis and Risk Management. The facility will be expanded from three to six cavities (RITS-6) effectively doubling the operating voltage. The increase in the operating voltage to above 10 MV has resulted in RITS-6 being classified as an accelerator facility. RITS-6 will come under DOE Order 420.2B, Safety of Accelerator Facilities. The hazards of RITS are detailed in the "Safety Assessment Document for the Radiographic Integrated Test Stand Facility." The principal non-industrial hazard is prompt x-ray radiation. As the operating voltage is increased, both the penetration power and the total amount (dose) of x-rays are increased, thereby increasing the risk to local personnel. Fixed site shielding (predominantly concrete walls and a steel/lead skyshine shield) is used to attenuate these x-rays and mitigate this risk. This SAND Report details the anticipated x-ray doses, the shielding design, and the anticipated x-ray doses external to this shielding structure both in areas where administrative access control restricts occupation and in adjacent uncontrolled areas.« less

Improved performances of CIBER-X: a new tabletop laser-driven electron and x-ray source

NASA Astrophysics Data System (ADS)

Girardeau-Montaut, Jean-Pierre; Kiraly, Bela; Girardeau-Montaut, Claire

2000-11-01

We present the most recent data concerning the performances of the table-top laser driven electron and x-ray source developed in our laboratory. X-ray pulses are produced by a three-step process which consists of the photoelectron emission from a thin metallic photocathode illuminated by 16 ps duration laser pulse at 213 nm. The e-gun is a standard pierce diode electrode type, in which electrons are accelerated by a cw electric fields of 12 MV/m. The photoinjector produced a train of 90 - 100 keV electron pulses of approximately 1 nC and 40 A peak current at a repetition rate of 10 Hz. The electrons, transported outside the diode, are focused onto a target of thulium by magnetic fields produced by two electromagnetic coils to produce x-rays. Applications to low dose imagery of inert and living materials are also presented.

High-energy synchrotron X-ray radiography of shock-compressed materials

NASA Astrophysics Data System (ADS)

Rutherford, Michael E.; Chapman, David J.; Collinson, Mark A.; Jones, David R.; Music, Jasmina; Stafford, Samuel J. P.; Tear, Gareth R.; White, Thomas G.; Winters, John B. R.; Drakopoulos, Michael; Eakins, Daniel E.

2015-06-01

This presentation will discuss the development and application of a high-energy (50 to 250 keV) synchrotron X-ray imaging method to study shock-compressed, high-Z samples at Beamline I12 at the Diamond Light Source synchrotron (Rutherford-Appleton Laboratory, UK). Shock waves are driven into materials using a portable, single-stage gas gun designed by the Institute of Shock Physics. Following plate impact, material deformation is probed in-situ by white-beam X-ray radiography and complimentary velocimetry diagnostics. The high energies, large beam size (13 x 13 mm), and appreciable sample volumes (~ 1 cm3) viable for study at Beamline I12 compliment existing in-house pulsed X-ray capabilities and studies at the Dynamic Compression Sector. The authors gratefully acknowledge the ongoing support of Imperial College London, EPSRC, STFC and the Diamond Light Source, and AWE Plc.

Generation of plasma X-ray sources via high repetition rate femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Baguckis, Artūras; Plukis, Artūras; Reklaitis, Jonas; Remeikis, Vidmantas; Giniūnas, Linas; Vengris, Mikas

2017-12-01

In this study, we present the development and characterization of Cu plasma X-ray source driven by 20 W average power high repetition rate femtosecond laser in ambient atmosphere environment. The peak Cu- Kα photon flux of 2.3 × 109 photons/s into full solid angle is demonstrated (with a process conversion efficiency of 10-7), using pulses with peak intensity of 4.65 × 1014 W/cm2. Such Cu- Kα flux is significantly larger than others found in comparable experiments, performed in air environment. The effects of resonance plasma absorption process, when optimized, are shown to increase measured flux by the factor of 2-3. The relationship between X-ray photon flux and plasma-driving pulse repetition rate is quasi-linear, suggesting that fluxes could further be increased to 1010 photons/s using even higher average powers of driving radiation. These results suggest that to fully utilize the potential of high repetition rate laser sources, novel target material delivery systems (for example, jet-based ones) are required. On the other hand, this study demonstrates that high energy lasers currently used for plasma X-ray sources can be conveniently and efficiently replaced by high average power and repetition rate laser radiation, as a way to increase the brightness of the generated X-rays.

Laser power meters as an X-ray power diagnostic for LCLS-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heimann, Philip; Moeller, Stefan; Carbajo, Sergio

For the LCLS-II X-ray instruments, laser power meters are being developed as compact X-ray power diagnostics to operate at soft and tender X-ray photon energies. These diagnostics can be installed at various locations along an X-ray free-electron laser (FEL) beamline in order to monitor the transmission of X-ray optics along the beam path. In addition, the power meters will be used to determine the absolute X-ray power at the endstations. Here, thermopile power meters, which measure average power, and have been chosen primarily for their compatibility with the high repetition rates at LCLS-II, are evaluated. Here, a number of characteristicsmore » in the soft X-ray range are presented including linearity, calibrations conducted with a photodiode and a gas monitor detector as well as ultra-high-vacuum compatibility tests using residual gas analysis. The application of these power meters for LCLS-II and other X-ray FEL sources is discussed.« less

Laser power meters as an X-ray power diagnostic for LCLS-II.

PubMed

Heimann, Philip; Moeller, Stefan; Carbajo, Sergio; Song, Sanghoon; Dakovski, Georgi; Nordlund, Dennis; Fritz, David

2018-01-01

For the LCLS-II X-ray instruments, laser power meters are being developed as compact X-ray power diagnostics to operate at soft and tender X-ray photon energies. These diagnostics can be installed at various locations along an X-ray free-electron laser (FEL) beamline in order to monitor the transmission of X-ray optics along the beam path. In addition, the power meters will be used to determine the absolute X-ray power at the endstations. Here, thermopile power meters, which measure average power, and have been chosen primarily for their compatibility with the high repetition rates at LCLS-II, are evaluated. A number of characteristics in the soft X-ray range are presented including linearity, calibrations conducted with a photodiode and a gas monitor detector as well as ultra-high-vacuum compatibility tests using residual gas analysis. The application of these power meters for LCLS-II and other X-ray FEL sources is discussed.

Laser power meters as an X-ray power diagnostic for LCLS-II

DOE PAGES

Heimann, Philip; Moeller, Stefan; Carbajo, Sergio; ...

2018-01-01

For the LCLS-II X-ray instruments, laser power meters are being developed as compact X-ray power diagnostics to operate at soft and tender X-ray photon energies. These diagnostics can be installed at various locations along an X-ray free-electron laser (FEL) beamline in order to monitor the transmission of X-ray optics along the beam path. In addition, the power meters will be used to determine the absolute X-ray power at the endstations. Here, thermopile power meters, which measure average power, and have been chosen primarily for their compatibility with the high repetition rates at LCLS-II, are evaluated. Here, a number of characteristicsmore » in the soft X-ray range are presented including linearity, calibrations conducted with a photodiode and a gas monitor detector as well as ultra-high-vacuum compatibility tests using residual gas analysis. The application of these power meters for LCLS-II and other X-ray FEL sources is discussed.« less

Design Considerations of a Virtual Laboratory for Advanced X-ray Sources

NASA Astrophysics Data System (ADS)

Luginsland, J. W.; Frese, M. H.; Frese, S. D.; Watrous, J. J.; Heileman, G. L.

2004-11-01

The field of scientific computation has greatly advanced in the last few years, resulting in the ability to perform complex computer simulations that can predict the performance of real-world experiments in a number of fields of study. Among the forces driving this new computational capability is the advent of parallel algorithms, allowing calculations in three-dimensional space with realistic time scales. Electromagnetic radiation sources driven by high-voltage, high-current electron beams offer an area to further push the state-of-the-art in high fidelity, first-principles simulation tools. The physics of these x-ray sources combine kinetic plasma physics (electron beams) with dense fluid-like plasma physics (anode plasmas) and x-ray generation (bremsstrahlung). There are a number of mature techniques and software packages for dealing with the individual aspects of these sources, such as Particle-In-Cell (PIC), Magneto-Hydrodynamics (MHD), and radiation transport codes. The current effort is focused on developing an object-oriented software environment using the Rational© Unified Process and the Unified Modeling Language (UML) to provide a framework where multiple 3D parallel physics packages, such as a PIC code (ICEPIC), a MHD code (MACH), and a x-ray transport code (ITS) can co-exist in a system-of-systems approach to modeling advanced x-ray sources. Initial software design and assessments of the various physics algorithms' fidelity will be presented.

X-ray generation using carbon nanotubes

NASA Astrophysics Data System (ADS)

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

2015-01-01

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

"X-Ray Transients in Star-Forming Regions" and "Hard X-Ray Emission from X-Ray Bursters"

NASA Technical Reports Server (NTRS)

Halpern, Jules P.; Kaaret, Philip

1999-01-01

This grant funded work on the analysis of data obtained with the Burst and Transient Experiment (BATSE) on the Compton Gamma-Ray Observatory. The goal of the work was to search for hard x-ray transients in star forming regions using the all-sky hard x-ray monitoring capability of BATSE. Our initial work lead to the discovery of a hard x-ray transient, GRO J1849-03. Follow-up observations of this source made with the Wide Field Camera on BeppoSAX showed that the source should be identified with the previously known x-ray pulsar GS 1843-02 which itself is identified with the x-ray source X1845-024 originally discovered with the SAS-3 satellite. Our identification of the source and measurement of the outburst recurrence time, lead to the identification of the source as a Be/X-ray binary with a spin period of 94.8 s and an orbital period of 241 days. The funding was used primarily for partial salary and travel support for John Tomsick, then a graduate student at Columbia University. John Tomsick, now Dr. Tomsick, received his Ph.D. from Columbia University in July 1999, based partially on results obtained under this investigation. He is now a postdoctoral research scientist at the University of California, San Diego.

High resolution microtomography for density and spatial infomation about wood structures

Treesearch

Barbara Illman; Betsy Dowd

1999-01-01

Microtomography has successfully been used to characterize loss of structural integrity of wood. Tomographic images were generated with the newly developed third generation x-ray computed microtomography (XCMT) instrument at the X27A beamline at the national Synchrotron Light source (NSLS). The beamline is equipped with high-flux x-ray monochromator based on multilayer...

Skylab

NASA Image and Video Library

1973-01-01

This chart describes the Skylab student experiment X-Ray Stellar Classes, proposed by Joe Reihs of Baton Rouge, Louisiana. This experiment utilized Skylab's X-Ray Spectrographic Telescope to observe and determine the general characteristics and location of x-ray sources. In March 1972, NASA and the National Science Teachers Association selected 25 experiment proposals for flight on Skylab. Science advisors from the Marshall Space Flight Center aided and assisted the students in developing the proposals for flight on Skylab.

The cosmic X-ray background. [heao observations

NASA Technical Reports Server (NTRS)

Boldt, E. A.

1980-01-01

The cosmic X-ray experiment carried out with the A2 Instrument on HEAO-1 made systematics-free measurements of the extra-galactic X-ray sky and yielded the broadband spectral characteristics for two extreme aspects of this radiation. For the apparently isotropic radiation of cosmological origin that dominates the extragalactic X-ray flux ( 3 keV), the spectrum over the energy band of maximum intensity is remarkably well described by a thermal model with a temperature of a half-billion degrees. At the other extreme, broadband observations of individual extragalactic X-ray sources with HEAO-1 are restricted to objects within the present epoch. While the non-thermal hard spectral components associated with unevolved X-ray emitting active galaxies could account for most of the gamma-ray background, the contribution of such sources to the X-ray background must be relatively small. In contrast, the 'deep-space' sources detected in soft X-rays with the HEAO-2 telescope probably represent a major portion of the extragalactic soft X-ray ( 3 keV) background.

The cosmic X-ray background-IRAS galaxy correlation and the local X-ray volume emissivity

NASA Technical Reports Server (NTRS)

Miyaji, Takamitsu; Lahav, Ofer; Jahoda, Keith; Boldt, Elihu

1994-01-01

We have cross-correlated the galaxies from the IRAS 2 Jy redshift survey sample and the 0.7 Jy projected sample with the all-sky cosmic X-ray background (CXB) map obtained from the High Energy Astronomy Observatory (HEAO) 1 A-2 experiment. We have detected a significant correlation signal between surface density of IRAS galaxies and the X-ray background intensity, with W(sub xg) = (mean value of ((delta I)(delta N)))/(mean value of I)(mean value of N)) of several times 10(exp -3). While this correlation signal has a significant implication for the contribution of the local universe to the hard (E greater than 2 keV) X-ray background, its interpretation is model-dependent. We have developed a formulation to model the cross-correlation between CXB surface brightness and galaxy counts. This includes the effects of source clustering and the X-ray-far-infrared luminosity correlation. Using an X-ray flux-limited sample of active galactic nuclei (AGNs), which has IRAS 60 micrometer measurements, we have estimated the contribution of the AGN component to the observed CXB-IRAS galaxy count correlations in order to see whether there is an excess component, i.e., contribution from low X-ray luminosity sources. We have applied both the analytical approach and Monte Carlo simulations for the estimations. Our estimate of the local X-ray volume emissivity in the 2-10 keV band is rho(sub x) approximately = (4.3 +/- 1.2) x 10(exp 38) h(sub 50) ergs/s/cu Mpc, consistent with the value expected from the luminosity function of AGNs alone. This sets a limit to the local volume emissivity from lower luminosity sources (e.g., star-forming galaxies, low-ionization nuclear emission-line regions (LINERs)) to rho(sub x) less than or approximately = 2 x 10(exp 38) h(sub 50) ergs/s/cu Mpc.

Advanced x-ray imaging spectrometer

NASA Technical Reports Server (NTRS)

Callas, John L. (Inventor); Soli, George A. (Inventor)

1998-01-01

An x-ray spectrometer that also provides images of an x-ray source. Coded aperture imaging techniques are used to provide high resolution images. Imaging position-sensitive x-ray sensors with good energy resolution are utilized to provide excellent spectroscopic performance. The system produces high resolution spectral images of the x-ray source which can be viewed in any one of a number of specific energy bands.

X-Ray Testing Constellation-X Optics at MSFC's 100-m Facility

NASA Technical Reports Server (NTRS)

O'Dell, Stephen; Baker, Markus; Content, David; Freeman, Mark; Glenn, Paul; Gubarev, Mikhail; Hair, Jason; Jones, William; Joy, Marshall

2003-01-01

In addition to the 530-m-long X-Ray Calibration Facility (XRCF), NASA's Marshall Space Flight Center (MSFC) operates a 104-m-long (source-to-detector) X-ray-test facility. Originally developed and still occasionally used for stray-light testing of visible-fight optical systems, the so-called "Stray-Light Facility" now serves primarily as a convenient and inexpensive facility for performance evaluation and calibration of X-ray optics and detectors. The facility can accommodate X-ray optics up to about 1-m diameter and 12-m focal length. Currently available electron-impact sources at the facility span the approximate energy range 0.2 to 100 keV, thus supporting testing of soft- and hard-X-ray optics and detectors. Available MSFC detectors are a front-illuminated CCD (charge-coupled device) and a scanning CZT (cadmium--zinc--telluride) detector, with low-energy cut-offs of about 0.8 and 3 keV, respectively. In order to test developmental optics for the Constellation-X Project, led by NASA's Goddard Space Flight Center (GSFC), MSFC undertook several enhancements to the facility. Foremost among these was development and fabrication of a five-degree-of-freedom (5-DoF) optics mount and control system, which translates and tilts the user-provided mirror assembly suspended from its interface plate. Initial Constellation-X tests characterize the performance of the Optical Alignment Pathfinder Two (OAP2) for the large Spectroscopy X-ray Telescope (SXT) and of demonstration mirror assemblies for the Hard X-ray Telescope (HXT). With the Centroid Detector Assembly (CDA), used for precision alignment of the Chandra (nee AXAF) mirrors, the Constellation-X SXT Team optically aligned the individual mirrors of the OAPZ at GSFC. The team then developed set-up and alignment procedures, including transfer of the alignment from the optical alignment facility at GSFC to the X-ray test facility at MSFC, using a reference flat and fiducials. The OAPZ incorporates additional ancillary features --- fixed aperture mask and movable sub-aperture mask --- to facilitate X-ray characterization of the optics. Although the OAPZ was designed to- have low sensitivity to temperature offsets and gradients, analyses showed the necessity of active temperature control for the X-ray performance testing. Thus, the Smithsonian Astrophysical Observatory (SAO) implemented a thermal control and monitoring system, designed to hold the OAP2 close to its assembly.

SOR Lithography in West Germany

NASA Astrophysics Data System (ADS)

Heuberger, Anton

1989-08-01

The 64 Mbit DRAM will represent the first generation of integrated circuits which cannot be produced reasonably by means of optical lithography techniques. X-ray lithography using synchrotron radiation seems to be the most promising method in overcoming the problems in the sub-0.5 micron range. The first year of production of the 64 Mbit DRAM will be 1995 or 1996. This means that X-ray lithography has to show its applicability in an industrial environment by 1992 and has to prove that the specifications of a 64 Mbit DRAM technology can actually be achieved. Part of this task is a demonstration of production suitable equipment such as the X-ray stepper, including an appropriate X-ray source and measurement and inspection tools. The most important bottlenecks on the way toward reaching these goals are linked to the 1 x scale mask technology, especially the pattern definition accuracy and zero level of printing defects down to the order of magnitude of 50 nm. Specifically, fast defect detection methods on the basis of high resolution e-beam techniques and repair methods have to be developed. The other problems of X-ray lithography, such as high quality single layer X-ray resists, X-ray sources and stepper including alignment are either well on the way or are already solved.

Identification of heavy metal origins related to chemical and morphological soil properties using several non-destructive X-ray analytical methods.

PubMed

Akbulut, Songul; Grieken, Renevan; Kılıc, Mehmet A; Cevik, Ugur; Rotondo, Giuliana G

2013-03-01

Soils are complex mixtures of organic, inorganic materials, and metal compounds from anthropogenic sources. In order to identify the pollution sources, their magnitude and development, several X-ray analytical methods were applied in this study. The concentrations of 16 elements were determined in all the soil samples using energy dispersive X-ray fluorescence spectrometry. Soils of unknown origin were observed by scanning electron microscopy equipped with a Si(Li) X-ray detector using Monte Carlo simulation approach. The mineralogical analyses were carried out using X-ray diffraction spectrometry. Due to the correlations between heavy metals and oxide compounds, the samples were analyzed also by electron probe microanalyzer (EPMA) in order to have information about their oxide contents. On the other hand, soil pH and salinity levels were identified owing to their influence between heavy metal and soil-surface chemistry. Moreover, the geoaccumulation index (I (geo)) enables the assessment of contamination by comparing current and pre-industrial concentrations.

The relationship between wave and geometrical optics models of coded aperture type x-ray phase contrast imaging systems

PubMed Central

Munro, Peter R.T.; Ignatyev, Konstantin; Speller, Robert D.; Olivo, Alessandro

2013-01-01

X-ray phase contrast imaging is a very promising technique which may lead to significant advancements in medical imaging. One of the impediments to the clinical implementation of the technique is the general requirement to have an x-ray source of high coherence. The radiation physics group at UCL is currently developing an x-ray phase contrast imaging technique which works with laboratory x-ray sources. Validation of the system requires extensive modelling of relatively large samples of tissue. To aid this, we have undertaken a study of when geometrical optics may be employed to model the system in order to avoid the need to perform a computationally expensive wave optics calculation. In this paper, we derive the relationship between the geometrical and wave optics model for our system imaging an infinite cylinder. From this model we are able to draw conclusions regarding the general applicability of the geometrical optics approximation. PMID:20389424

The relationship between wave and geometrical optics models of coded aperture type x-ray phase contrast imaging systems.

PubMed

Munro, Peter R T; Ignatyev, Konstantin; Speller, Robert D; Olivo, Alessandro

2010-03-01

X-ray phase contrast imaging is a very promising technique which may lead to significant advancements in medical imaging. One of the impediments to the clinical implementation of the technique is the general requirement to have an x-ray source of high coherence. The radiation physics group at UCL is currently developing an x-ray phase contrast imaging technique which works with laboratory x-ray sources. Validation of the system requires extensive modelling of relatively large samples of tissue. To aid this, we have undertaken a study of when geometrical optics may be employed to model the system in order to avoid the need to perform a computationally expensive wave optics calculation. In this paper, we derive the relationship between the geometrical and wave optics model for our system imaging an infinite cylinder. From this model we are able to draw conclusions regarding the general applicability of the geometrical optics approximation.

Simulating the x-ray image contrast to setup techniques with desired flaw detectability

NASA Astrophysics Data System (ADS)

Koshti, Ajay M.

2015-04-01

The paper provides simulation data of previous work by the author in developing a model for estimating detectability of crack-like flaws in radiography. The methodology is developed to help in implementation of NASA Special x-ray radiography qualification, but is generically applicable to radiography. The paper describes a method for characterizing the detector resolution. Applicability of ASTM E 2737 resolution requirements to the model are also discussed. The paper describes a model for simulating the detector resolution. A computer calculator application, discussed here, also performs predicted contrast and signal-to-noise ratio calculations. Results of various simulation runs in calculating x-ray flaw size parameter and image contrast for varying input parameters such as crack depth, crack width, part thickness, x-ray angle, part-to-detector distance, part-to-source distance, source sizes, and detector sensitivity and resolution are given as 3D surfaces. These results demonstrate effect of the input parameters on the flaw size parameter and the simulated image contrast of the crack. These simulations demonstrate utility of the flaw size parameter model in setting up x-ray techniques that provide desired flaw detectability in radiography. The method is applicable to film radiography, computed radiography, and digital radiography.

Inverse Compton scattering X-ray source yield optimization with a laser path folding system inserted in a pre-existent RF linac

NASA Astrophysics Data System (ADS)

Chaleil, A.; Le Flanchec, V.; Binet, A.; Nègre, J. P.; Devaux, J. F.; Jacob, V.; Millerioux, M.; Bayle, A.; Balleyguier, P.; Prazeres, R.

2016-12-01

An inverse Compton scattering source is under development at the ELSA linac of CEA, Bruyères-le-Châtel. Ultra-short X-ray pulses are produced by inverse Compton scattering of 30 ps-laser pulses by relativistic electron bunches. The source will be able to operate in single shot mode as well as in recurrent mode with 72.2 MHz pulse trains. Within this framework, an optical multipass system that multiplies the number of emitted X-ray photons in both regimes has been designed in 2014, then implemented and tested on ELSA facility in the course of 2015. The device is described from both geometrical and timing viewpoints. It is based on the idea of folding the laser optical path to pile-up laser pulses at the interaction point, thus increasing the interaction probability. The X-ray output gain measurements obtained using this system are presented and compared with calculated expectations.

Noise properties and task-based evaluation of diffraction-enhanced imaging

PubMed Central

Brankov, Jovan G.; Saiz-Herranz, Alejandro; Wernick, Miles N.

2014-01-01

Abstract. Diffraction-enhanced imaging (DEI) is an emerging x-ray imaging method that simultaneously yields x-ray attenuation and refraction images and holds great promise for soft-tissue imaging. The DEI has been mainly studied using synchrotron sources, but efforts have been made to transition the technology to more practical implementations using conventional x-ray sources. The main technical challenge of this transition lies in the relatively lower x-ray flux obtained from conventional sources, leading to photon-limited data contaminated by Poisson noise. Several issues that must be understood in order to design and optimize DEI imaging systems with respect to noise performance are addressed. Specifically, we: (a) develop equations describing the noise properties of DEI images, (b) derive the conditions under which the DEI algorithm is statistically optimal, (c) characterize the imaging performance that can be obtained as measured by task-based metrics, and (d) consider image-processing steps that may be employed to mitigate noise effects. PMID:26158056

GSFC Contributions to the NATO X-ray Astronomy Institute, Erice, July 1979. [X-ray spectra of supernova remants, galactic X-ray sources, active galactic nuclei, and clusters of galaxies

NASA Technical Reports Server (NTRS)

Holt, S. S.; Mushotzky, R. F.

1979-01-01

An overview of X-ray astronomical spectroscopy in general is presented and results obtained by HEAO 1 and 2 as well as earlier spacecraft are examined. Particular emphasis is given to the spectra of supernova remnants; galactic binary X-ray sources, cataclysmic variables, bulges, pulsars, and stars; the active nuclei of Seyfert 1 galaxy, BL Lac, and quasars; the diffuse X-ray background; and galactic clusters.

A NAIVE BAYES SOURCE CLASSIFIER FOR X-RAY SOURCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Broos, Patrick S.; Getman, Konstantin V.; Townsley, Leisa K.

2011-05-01

The Chandra Carina Complex Project (CCCP) provides a sensitive X-ray survey of a nearby starburst region over >1 deg{sup 2} in extent. Thousands of faint X-ray sources are found, many concentrated into rich young stellar clusters. However, significant contamination from unrelated Galactic and extragalactic sources is present in the X-ray catalog. We describe the use of a naive Bayes classifier to assign membership probabilities to individual sources, based on source location, X-ray properties, and visual/infrared properties. For the particular membership decision rule adopted, 75% of CCCP sources are classified as members, 11% are classified as contaminants, and 14% remain unclassified.more » The resulting sample of stars likely to be Carina members is used in several other studies, which appear in this special issue devoted to the CCCP.« less

Simultaneous measurements of X-ray reflectivity and grazing incidence fluorescence at BL-16 beamline of Indus-2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Gangadhar; Kane, S. R.; Khooha, Ajay

2015-05-15

A new multipurpose x-ray reflectometer station has been developed and augmented at the microfocus beamline (BL-16) of Indus-2 synchrotron radiation source to facilitate synchronous measurements of specular x-ray reflectivity and grazing incidence x-ray fluorescence emission from thin layered structures. The design and various salient features of the x-ray reflectometer are discussed. The performance of the reflectometer has been evaluated by analyzing several thin layered structures having different surface interface properties. The results reveal in-depth information for precise determination of surface and interface properties of thin layered materials demonstrating the immense potential of the combined measurements of x-ray reflectivity and grazingmore » incidence fluorescence on a single reflectometer.« less

Quantitative Measurements of X-ray Intensity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haugh, M. J., Schneider, M.

This chapter describes the characterization of several X-ray sources and their use in calibrating different types of X-ray cameras at National Security Technologies, LLC (NSTec). The cameras are employed in experimental plasma studies at Lawrence Livermore National Laboratory (LLNL), including the National Ignition Facility (NIF). The sources provide X-rays in the energy range from several hundred eV to 110 keV. The key to this effort is measuring the X-ray beam intensity accurately and traceable to international standards. This is accomplished using photodiodes of several types that are calibrated using radioactive sources and a synchrotron source using methods and materials thatmore » are traceable to the U.S. National Institute of Standards and Technology (NIST). The accreditation procedures are described. The chapter begins with an introduction to the fundamental concepts of X-ray physics. The types of X-ray sources that are used for device calibration are described. The next section describes the photodiode types that are used for measuring X-ray intensity: power measuring photodiodes, energy dispersive photodiodes, and cameras comprising photodiodes as pixel elements. Following their description, the methods used to calibrate the primary detectors, the power measuring photodiodes and the energy dispersive photodiodes, as well as the method used to get traceability to international standards are described. The X-ray source beams can then be measured using the primary detectors. The final section then describes the use of the calibrated X-ray beams to calibrate X-ray cameras. Many of the references are web sites that provide databases, explanations of the data and how it was generated, and data calculations for specific cases. Several general reference books related to the major topics are included. Papers expanding some subjects are cited.« less

Development of a short duration backlit pinhole for radiography on the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huntington, C. M.; Krauland, C. M.; Kuranz, C. C.

2010-10-15

Experiments on the National Ignition Facility (NIF) will require bright, short duration, near-monochromatic x-ray backlighters for radiographic diagnosis of many high-energy density systems. This paper details a vanadium pinhole backlighter producing (1.8{+-}0.5)x10{sup 15} x-ray photons into 4{pi} sr near the vanadium He-like characteristic x-ray energy of 5.18 keV. The x-ray yield was quantified from a set of Ross filters imaged to a calibrated image plate, with the Dante diagnostic used to confirm the quasimonochromatic nature of the spectrum produced. Additionally, an x-ray film image shows a source-limited image resolution of 26 {mu}m from a 20 {mu}m diameter pinhole.

The Origin of Soft X-rays in DQ Herculis

NASA Technical Reports Server (NTRS)

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

2002-01-01

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

A platform for detecting material melting from shock compression using the NIF x-ray diffraction diagnostic TARDIS

NASA Astrophysics Data System (ADS)

Wehrenberg, Christopher; Kraus, Richard; Braun, Dave; Rygg, Ryan; Coppari, Federica; Lazicki, Amy; McNaney, James; Eggert, Jon

2016-10-01

A series of experiments were performed on NIF to develop a platform to detect material melting during shock compression using x-ray diffraction. The unique pulse shaping on NIF can be utilized to directly-drive a steady shock into an ablator and material sample while simultaneously creating an x-ray source to probe the material state. Sharp diffraction lines are observed when the material is in the solid state, while broad diffuse lines are seen when in the liquid state, providing an unambiguous signal for shock driven melting. Several shots were performed in which a shock of 50-80 GPa was driven into a Pb sample while a Ge foil was used as an x-ray source probe. Laser conditions were varied to create a suitable x-ray source that provides a short, bright burst of He-alpha emission from the Ge while maintaining a low background level on the image plates contained in the TARDIS diagnostic. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

Modification of the TASMIP x-ray spectral model for the simulation of microfocus x-ray sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sisniega, A.; Vaquero, J. J., E-mail: juanjose.vaquero@uc3m.es; Instituto de Investigación Sanitaria Gregorio Marañón, Madrid ES28007

2014-01-15

Purpose: The availability of accurate and simple models for the estimation of x-ray spectra is of great importance for system simulation, optimization, or inclusion of photon energy information into data processing. There is a variety of publicly available tools for estimation of x-ray spectra in radiology and mammography. However, most of these models cannot be used directly for modeling microfocus x-ray sources due to differences in inherent filtration, energy range and/or anode material. For this reason the authors propose in this work a new model for the simulation of microfocus spectra based on existing models for mammography and radiology, modifiedmore » to compensate for the effects of inherent filtration and energy range. Methods: The authors used the radiology and mammography versions of an existing empirical model [tungsten anode spectral model interpolating polynomials (TASMIP)] as the basis of the microfocus model. First, the authors estimated the inherent filtration included in the radiology model by comparing the shape of the spectra with spectra from the mammography model. Afterwards, the authors built a unified spectra dataset by combining both models and, finally, they estimated the parameters of the new version of TASMIP for microfocus sources by calibrating against experimental exposure data from a microfocus x-ray source. The model was validated by comparing estimated and experimental exposure and attenuation data for different attenuating materials and x-ray beam peak energy values, using two different x-ray tubes. Results: Inherent filtration for the radiology spectra from TASMIP was found to be equivalent to 1.68 mm Al, as compared to spectra obtained from the mammography model. To match the experimentally measured exposure data the combined dataset required to apply a negative filtration of about 0.21 mm Al and an anode roughness of 0.003 mm W. The validation of the model against real acquired data showed errors in exposure and attenuation in line with those reported for other models for radiology or mammography. Conclusions: A new version of the TASMIP model for the estimation of x-ray spectra in microfocus x-ray sources has been developed and validated experimentally. Similarly to other versions of TASMIP, the estimation of spectra is very simple, involving only the evaluation of polynomial expressions.« less

Chandra Detection of Intracluster X-Ray sources in Virgo

NASA Astrophysics Data System (ADS)

Hou, Meicun; Li, Zhiyuan; Peng, Eric W.; Liu, Chengze

2017-09-01

We present a survey of X-ray point sources in the nearest and dynamically young galaxy cluster, Virgo, using archival Chandra observations that sample the vicinity of 80 early-type member galaxies. The X-ray source populations at the outskirts of these galaxies are of particular interest. We detect a total of 1046 point sources (excluding galactic nuclei) out to a projected galactocentric radius of ˜40 kpc and down to a limiting 0.5-8 keV luminosity of ˜ 2× {10}38 {erg} {{{s}}}-1. Based on the cumulative spatial and flux distributions of these sources, we statistically identify ˜120 excess sources that are not associated with the main stellar content of the individual galaxies, nor with the cosmic X-ray background. This excess is significant at a 3.5σ level, when Poisson error and cosmic variance are taken into account. On the other hand, no significant excess sources are found at the outskirts of a control sample of field galaxies, suggesting that at least some fraction of the excess sources around the Virgo galaxies are truly intracluster X-ray sources. Assisted with ground-based and HST optical imaging of Virgo, we discuss the origins of these intracluster X-ray sources, in terms of supernova-kicked low-mass X-ray binaries (LMXBs), globular clusters, LMXBs associated with the diffuse intracluster light, stripped nucleated dwarf galaxies and free-floating massive black holes.

Nondestructive Imaging of Internal Structures of Frog (Xenopus laevis) Embryos by Shadow-Projection X-Ray Microtomography

NASA Astrophysics Data System (ADS)

Aoki, Sadao; Yoneda, Ikuo; Nagai, Takeharu; Ueno, Naoto; Murakami, Kazuo

1994-04-01

Nondestructive high-resolution imaging of frog ( Xenopus laevis) embryos has been developed by X-ray microtomography. Shadow-projection X-ray microtomography with a brilliant fine focus laboratory X-ray source could image fine structures of Xenopus embryos which were embedded in paraffin wax. The imaging system enabled us to not only distinguish endoderm from ectoderm at the gastrula stage, but also to obtain a cross-section view of the tail bud embryo showing muscle, notochord and neural tube without staining. Furthermore, the distribution of myosin was also imaged in combination with whole-mount immunohistochemistry.

LCLS in—photon out: fluorescence measurement of neon using soft x-rays

DOE PAGES

Obaid, Razib; Buth, Christian; Dakovski, Georgi L.; ...

2018-01-09

Here, we measured the fluorescence photon yield of neon upon soft x-ray ionization (~1200 eV) from the x-ray free-electron laser at Linac Coherent Light Source, and demonstrated the usage of a grazing incidence spectrometer with a variable line spacing grating to perform x-ray fluorescence spectroscopy on a gas phase system. Our measurements also allowed us to estimate the focal size of the beam from the theoretical description developed, in terms of the rate equation approximation accounting for photoionization shake off of neutral neon and double auger decay of single core holes.

LCLS in—photon out: fluorescence measurement of neon using soft x-rays

NASA Astrophysics Data System (ADS)

Obaid, Razib; Buth, Christian; Dakovski, Georgi L.; Beerwerth, Randolf; Holmes, Michael; Aldrich, Jeff; Lin, Ming-Fu; Minitti, Michael; Osipov, Timur; Schlotter, William; Cederbaum, Lorenz S.; Fritzsche, Stephan; Berrah, Nora

2018-02-01

We measured the fluorescence photon yield of neon upon soft x-ray ionization (∼1200 eV) from the x-ray free-electron laser at Linac Coherent Light Source, and demonstrated the usage of a grazing incidence spectrometer with a variable line spacing grating to perform x-ray fluorescence spectroscopy on a gas phase system. Our measurements also allowed us to estimate the focal size of the beam from the theoretical description developed, in terms of the rate equation approximation accounting for photoionization shake off of neutral neon and double auger decay of single core holes.

The UHURU X-ray instrument.

NASA Technical Reports Server (NTRS)

Jagoda, N.; Austin, G.; Mickiewicz, S.; Goddard, R.

1972-01-01

On Dec. 12, 1970, the UHURU X-ray observatory was launched into equatorial orbit with the prime mission of conducting an all-sky survey of astronomical X-ray sources with intensities of 0.00005 Sco-X1 or greater. The X-ray detection system contains 12 gas-filled proportional counters, 6 behind each collimator. The aspect system is discussed together with the structure, the pulse height analyzer, the command system, the calibration system, and the power distribution system. Pulse shape discrimination circuits used on UHURU use the same technique that was used on the system originally developed for large area proportional counters described by Gorenstein and Mickiewicz (1968).

Development of In-situ Resonant Soft X-ray Scattering for Soft Materials at Advanced Light Source

NASA Astrophysics Data System (ADS)

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

2014-03-01

Resonant Soft X-ray Scattering was developed at ALS over the past a few years. It combines soft x-ray spectroscopy with x-ray scattering and offers statistical information for 3D chemical morphology over a large sample area. Its unique chemical sensitivity, large accessible size scale, polarization control and high coherence make it a powerful tool for mesoscale chemical/morphological structure characterization for many classes of materials. However, 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, we will report our development of customize design liquid/gas environmental cells that will enable soft x-ray scattering experiments on biological, electro-chemical, self-assembly, and hierarchical functional systems in both static and dynamic fashion. Initial RSoXS result of solar fuel membrane assembly/fuel-cell membrane structure in wet cell will be presented.

A decade of Rossi X-ray Timing Explorer Seyfert observations: An RXTE Seyfert spectral database

NASA Astrophysics Data System (ADS)

Mattson, Barbara Jo

2008-10-01

With over forty years of X-ray observations, we should have a grasp on the X- ray nature of active galactic nuclei (AGN). The unification model of Antonucci and Miller (1985) offered a context for understanding observations by defining a "typical" AGN geometry, with observed spectral differences explained by line- of-sight effects. However, the emerging picture is that the central AGN is more complex than unification alone can describe. We explore the unified model with a systematic X-ray spectral study of bright Seyfert galaxies observed by the Rossi X-Ray Timing Explorer (RXTE) over its first 10 years. We develop a spectral-fit database of 821 time-resolved spectra from 39 Seyfert galaxies fitted to a model describing the effects of an X-ray power-law spectrum reprocessed and absorbed by material in the central AGN region. We observe a relationship between radio and X-ray properties for Seyfert 1s, with the spectral parameters differing between radio-loud and radio-quiet Seyfert 1s. We also find a complex relationship between the Fe K equivalent width ( EW ) and the power-law photon index (Gamma) for the Seyfert 1s, with a correlation for the radio-loud sources and an anti-correlation for the radio- quiet sources. These results can be explained if X-rays from the relativistic jet in radio-loud sources contribute significantly to the observed spectrum. We observe scatter in the EW-Gamma relationship for the Seyfert 2s, suggesting complex environments that unification alone cannot explain. We see a strong correlation between Gamma and the reflection fraction ( R ) in the Seyfert 1 and 2 samples, but modeling degeneracies are present, so this relationship cannot be trusted as instructive of the AGN physics. For the Seyfert 1 sample, we find an anticorrelation between EW and the 2 to 10 keV luminosity ( L x ), also known as the X-ray Baldwin effect. This may suggest that higher luminosity sources contain less material or may be due to a time-lag effect. We do not observe the previously reported relationship between Gamma and the ratio of L x to the Eddington luminosity.

Optics Developments for X-Ray Astronomy

NASA Technical Reports Server (NTRS)

Ramsey, Brian

2014-01-01

X-ray optics has revolutionized x-ray astronomy. The degree of background suppression that these afford, have led to a tremendous increase in sensitivity. The current Chandra observatory has the same collecting area (approx. 10(exp 3)sq cm) as the non-imaging UHURU observatory, the first x-ray observatory which launched in 1970, but has 5 orders of magnitude more sensitivity due to its focusing optics. In addition, its 0.5 arcsec angular resolution has revealed a wealth of structure in many cosmic x-ray sources. The Chandra observatory achieved its resolution by using relatively thick pieces of Zerodur glass, which were meticulously figured and polished to form the four-shell nested array. The resulting optical assembly weighed around 1600 kg, and cost approximately $0.5B. The challenge for future x-ray astronomy missions is to greatly increase the collecting area (by one or more orders of magnitude) while maintaining high angular resolution, and all within realistic mass and budget constraints. A review of the current status of US optics for x-ray astronomy will be provided along with the challenges for future developments.

Comparative study of X-ray emission from plasma focus relative to different preionization schemes

NASA Astrophysics Data System (ADS)

Ahmad, S.; Qayyum, A.; Hassan, M.; Zakaullah, M.

2017-07-01

A 2.7-kJ Mather-type plasma focus has been investigated for X-ray emission with preionization produced by an α-source, a β-source, and a shunt resistor. Time-resolved and time integrated measurements are carried out using a PIN-diode-based X-ray spectrometer and pinhole camera. The β-source (28Ni63) assisted preionization enhances the X-ray emission up to 25%, while preionization induced by depleted uranium (92U238) increases both Cu-Kα and total X-ray yield of about 100%. The preionization caused by the optimum shunt resistor enhances the Cu-Kα and total X-ray yield of about 53%. It is found that preionization also broadens the working pressure range for the high X-ray yield and improves the shot-to-shot reproducibility of the system. Pinhole images reveal that the X-ray emission from the anode tip is dominant owing to impact of electron bombardment, while the X-ray emission from hot spots is also visible.

Projection x-ray topography system at 1-BM x-ray optics test beamline at the advanced photon source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoupin, Stanislav, E-mail: sstoupin@aps.anl.gov; Liu, Zunping; Trakhtenberg, Emil

2016-07-27

Projection X-ray topography of single crystals is a classic technique for the evaluation of intrinsic crystal quality of large crystals. In this technique a crystal sample and an area detector (e.g., X-ray film) collecting intensity of a chosen crystallographic reflection are translated simultaneously across an X-ray beam collimated in the diffraction scattering plane (e.g., [1, 2]). A bending magnet beamline of a third-generation synchrotron source delivering x-ray beam with a large horizontal divergence, and therefore, a large horizontal beam size at a crystal sample position offers an opportunity to obtain X-ray topographs of large crystalline samples (e.g., 6-inch wafers) inmore » just a few exposures. Here we report projection X-ray topography system implemented recently at 1-BM beamline of the Advanced Photon Source. A selected X-ray topograph of a 6-inch wafer of 4H-SiC illustrates capabilities and limitations of the technique.« less

The x ray morphology of the relaxed cluster of galaxies A2256. 2: Sources around the extended cluster emission

NASA Technical Reports Server (NTRS)

Henry, J. Patrick; Briel, U. G.

1991-01-01

X-ray emission from cluster galaxies as well as from 'dark objects' (i.e. not visible on the Palomar Observatory Sky Survey (POSS)) seen in the x-ray observation of A2256 with the imaging proportional counter on board ROSAT (x-ray astronomy satellite), is reported. This observation revealed significantly more sources in the field around the extended cluster emission than one would expect by chance. In a preliminary investigation, 14 sources were discovered at the limiting flux for this exposure, whereas about 7 sources would have been expected by chance. At least two of those sources are coincident with cluster member galaxies, having x-ray luminosities of approximately 10(exp +42) erg/s in the ROSAT energy band from 0.1 to 2.4 keV, but at least four more are from 'dark' objects. The similarity of these objects to those in A1367 suggests the existence of a new class of x-ray sources in clusters.

The black hole candidate MAXI J1659-152 in and towards quiescence in X-ray and radio

NASA Astrophysics Data System (ADS)

Jonker, P. G.; Miller-Jones, J. C. A.; Homan, J.; Tomsick, J.; Fender, R. P.; Kaaret, P.; Markoff, S.; Gallo, E.

2012-07-01

In this paper we report on Expanded Very Large Array radio and Chandra and Swift X-ray observations of the outburst decay of the transient black hole candidate MAXI J1659-152 in 2011. We discuss the distance to the source taking the high inclination into account and conclude that the source distance is probably 6 ± 2 kpc. The lowest observed flux corresponds to a luminosity of ? erg s-1. This, together with the orbital period of 2.4 h reported in the literature, suggests that the quiescent X-ray luminosity is higher than predicted on the basis of the orbital period-quiescent X-ray luminosity relationship. It is more in line with that expected for a neutron star, although the outburst spectral and timing properties reported in the literature strongly suggest that MAXI J1659-152 harbours a black hole. This conclusion is subject to confirmation of the lowest observed flux as the quiescent flux. The relation between the accretion and ejection mechanisms can be studied using the observed correlation between the radio and X-ray luminosities as these evolve over an outburst. We determine the behaviour of MAXI J1659-152 in the radio-X-ray diagram at low X-ray luminosities using the observations reported in this paper and at high X-ray luminosities using values reported in the literature. At high X-ray luminosities, the source lies closer to the sources that follow a correlation index steeper than 0.6-0.7. However, when compared to other sources that follow a steeper correlation index, the X-ray luminosity in MAXI J1659-152 is also lower. The latter can potentially be explained by the high inclination of MAXI J1659-152 if the X-ray emission comes from close to the source and the radio emission is originating in a more extended region. However, it is probable that the source was not in the canonical low-hard state during these radio observations and this may affect the behaviour of the source as well. At intermediate X-ray luminosities, the source makes the transition from the radio underluminous sources in the direction of the relation traced by the 'standard' correlation similar to what has been reported for H 1743-322 in the literature. However, MAXI J1659-152 remains underluminous with respect to this 'standard' correlation.

Infrastructure development for radioactive materials at the NSLS-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sprouster, D. J.; Weidner, R.; Ghose, S. K.

2018-02-01

The X-ray Powder Diffraction (XPD) Beamline at the National Synchrotron Light Source-II is a multipurpose instrument designed for high-resolution, high-energy X-ray scattering techniques. In this article, the capabilities, opportunities and recent developments in the characterization of radioactive materials at XPD are described. The overarching goal of this work is to provide researchers access to advanced synchrotron techniques suited to the structural characterization of materials for advanced nuclear energy systems. XPD is a new beamline providing high photon flux for X-ray Diffraction, Pair Distribution Function analysis and Small Angle X-ray Scattering. The infrastructure and software described here extend the existing capabilitiesmore » at XPD to accommodate radioactive materials. Such techniques will contribute crucial information to the characterization and quantification of advanced materials for nuclear energy applications. We describe the automated radioactive sample collection capabilities and recent X-ray Diffraction and Small Angle X-ray Scattering results from neutron irradiated reactor pressure vessel steels and oxide dispersion strengthened steels.« less

Infrastructure development for radioactive materials at the NSLS-II

DOE PAGES

Sprouster, David J.; Weidner, R.; Ghose, S. K.; ...

2017-11-04

The X-ray Powder Diffraction (XPD) Beamline at the National Synchrotron Light Source-II is a multipurpose instrument designed for high-resolution, high-energy X-ray scattering techniques. In this paper, the capabilities, opportunities and recent developments in the characterization of radioactive materials at XPD are described. The overarching goal of this work is to provide researchers access to advanced synchrotron techniques suited to the structural characterization of materials for advanced nuclear energy systems. XPD is a new beamline providing high photon flux for X-ray Diffraction, Pair Distribution Function analysis and Small Angle X-ray Scattering. The infrastructure and software described here extend the existing capabilitiesmore » at XPD to accommodate radioactive materials. Such techniques will contribute crucial information to the characterization and quantification of advanced materials for nuclear energy applications. Finally, we describe the automated radioactive sample collection capabilities and recent X-ray Diffraction and Small Angle X-ray Scattering results from neutron irradiated reactor pressure vessel steels and oxide dispersion strengthened steels.« less

Enhancing Tabletop X-Ray Phase Contrast Imaging with Nano-Fabrication

PubMed Central

Miao, Houxun; Gomella, Andrew A.; Harmon, Katherine J.; Bennett, Eric E.; Chedid, Nicholas; Znati, Sami; Panna, Alireza; Foster, Barbara A.; Bhandarkar, Priya; Wen, Han

2015-01-01

X-ray phase-contrast imaging is a promising approach for improving soft-tissue contrast and lowering radiation dose in biomedical applications. While current tabletop imaging systems adapt to common x-ray tubes and large-area detectors by employing absorptive elements such as absorption gratings or monolithic crystals to filter the beam, we developed nanometric phase gratings which enable tabletop x-ray far-field interferometry with only phase-shifting elements, leading to a substantial enhancement in the performance of phase contrast imaging. In a general sense the method transfers the demands on the spatial coherence of the x-ray source and the detector resolution to the feature size of x-ray phase masks. We demonstrate its capabilities in hard x-ray imaging experiments at a fraction of clinical dose levels and present comparisons with the existing Talbot-Lau interferometer and with conventional digital radiography. PMID:26315891

MIT modular x-ray source systems for the study of plasma diagnostics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coleman, J.W.; Wenzel, K.W.; Petrasso, R.D.

1992-10-01

Two new x-ray source systems are now on line at our facility. Each provides an {ital e}-beam to 25 kV. Targets are interchangeable between machines, and four x-ray detectors may be used simultaneously with a target. The gridded {ital e}-gun of the RACEHORSE system gives a 0.5--1.0-cm pulsable spot on target. The nongridded {ital e}-gun of the SCORPION system provides a 0.3-mm or smaller dc microspot on target. RACEHORSE is being used to study and characterize type-II diamond photoconductors for use in diagnosing plasmas, while SCORPION is being used to develop a slitless spectrograph using photographic film. Source design detailsmore » and some RACEHORSE results are presented.« less

Bioenvironmental Engineer’s Guide to Ionizing Radiation

DTIC Science & Technology

2005-10-01

mercury x-rays 186 (4 % ) - y Ra -226 radon x-rays Luminous Products, Neutron (tl/2: 1600 y) Alpha photons from daughters: Sources (w/ Be ) Rn-222, Po...Radioisotope Thermoelectric (t1,2: 88 y) Generators Pu-239 Alpha uranium x-rays Nuclear Weapons, Neutron (t1 /2: 2.4 x 104 y) Sources (w/ Be ...Calibration Am-241 .60 (36 %) - Static Eliminators, Chemical (h2: 432 y) Alpha n Agent Detectors, Neutron neptunium x-rays Sources (w/ Be ) 11 October 2005

Capillary Optics Based X-Ray Micro-Imaging Elemental Analysis

NASA Astrophysics Data System (ADS)

Hampai, D.; Dabagov, S. B.; Cappuccio, G.; Longoni, A.; Frizzi, T.; Cibin, G.

2010-04-01

A rapidly developed during the last few years micro-X-ray fluorescence spectrometry (μXRF) is a promising multi-elemental technique for non-destructive analysis. Typically it is rather hard to perform laboratory μXRF analysis because of the difficulty of producing an original small-size X-ray beam as well as its focusing. Recently developed for X-ray beam focusing polycapillary optics offers laboratory X-ray micro probes. The combination of polycapillary lens and fine-focused micro X-ray tube can provide high intensity radiation flux on a sample that is necessary in order to perform the elemental analysis. In comparison to a pinhole, an optimized "X-ray source-op tics" system can result in radiation density gain of more than 3 orders by the value. The most advanced way to get that result is to use the confocal configuration based on two X-ray lenses, one for the fluorescence excitation and the other for the detection of secondary emission from a sample studied. In case of X-ray capillary microfocusing a μXRF instrument designed in the confocal scheme allows us to obtain a 3D elemental mapping. In this work we will show preliminary results obtained with our prototype, a portable X-ray microscope for X-ray both imaging and fluorescence analysis; it enables μXRF elemental mapping simultaneously with X-ray imaging. A prototype of compact XRF spectrometer with a spatial resolution less than 100 μm has been designed.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wharton, C. J.; Seabury, E. H.; Chichester, D. L.

2011-06-01

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

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

NASA Astrophysics Data System (ADS)

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

2011-06-01

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

Ion polished Cr/Sc attosecond multilayer mirrors for high water window reflectivity

DOE PAGES

Guggenmos, Alexander; Radünz, Stefan; Rauhut, Roman; ...

2014-01-20

Recent advances in the development of attosecond soft X-ray sources ranging into the water window spectral range, between the 1s states of carbon and oxygen (284 eV–543 eV), are also driving the development of suited broadband multilayer optics for steering and shaping attosecond pulses. The relatively low intensity of current High Harmonic Generation (HHG) soft X-ray sources calls for an efficient use of photons, thus the development of low-loss multilayer optics is of uttermost importance. Here, we report about the realization of broadband Cr/Sc attosecond multilayer mirrors with nearly atomically smooth interfaces by an optimized ion beam deposition and assistedmore » interface polishing process. This yields to our knowledge highest multilayer mirror reflectivity at 300 eV near normal incidence. The results are verified by transmission electron microscopy (TEM) and soft/hard X-ray reflectometry.« less

Ion polished Cr/Sc attosecond multilayer mirrors for high water window reflectivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guggenmos, Alexander; Radünz, Stefan; Rauhut, Roman

Recent advances in the development of attosecond soft X-ray sources ranging into the water window spectral range, between the 1s states of carbon and oxygen (284 eV–543 eV), are also driving the development of suited broadband multilayer optics for steering and shaping attosecond pulses. The relatively low intensity of current High Harmonic Generation (HHG) soft X-ray sources calls for an efficient use of photons, thus the development of low-loss multilayer optics is of uttermost importance. Here, we report about the realization of broadband Cr/Sc attosecond multilayer mirrors with nearly atomically smooth interfaces by an optimized ion beam deposition and assistedmore » interface polishing process. This yields to our knowledge highest multilayer mirror reflectivity at 300 eV near normal incidence. The results are verified by transmission electron microscopy (TEM) and soft/hard X-ray reflectometry.« less

Three-dimensional monochromatic x-ray computed tomography using synchrotron radiation

NASA Astrophysics Data System (ADS)

Saito, Tsuneo; Kudo, Hiroyuki; Takeda, Tohoru; Itai, Yuji; Tokumori, Kenji; Toyofuku, Fukai; Hyodo, Kazuyuki; Ando, Masami; Nishimura, Katsuyuki; Uyama, Chikao

1998-08-01

We describe a technique of 3D computed tomography (3D CT) using monochromatic x rays generated by synchrotron radiation, which performs a direct reconstruction of a 3D volume image of an object from its cone-beam projections. For the development, we propose a practical scanning orbit of the x-ray source to obtain complete 3D information on an object, and its corresponding 3D image reconstruction algorithm. The validity and usefulness of the proposed scanning orbit and reconstruction algorithm were confirmed by computer simulation studies. Based on these investigations, we have developed a prototype 3D monochromatic x-ray CT using synchrotron radiation, which provides exact 3D reconstruction and material-selective imaging by using the K-edge energy subtraction technique.

The Mapping X-Ray Fluorescence Spectrometer (mapx)

NASA Astrophysics Data System (ADS)

Blake, D. F.; Sarrazin, P.; Bristow, T.; Downs, R. T.; Gailhanou, M.; Marchis, F.; Ming, D. W.; Morris, R. V.; Sole, V. A.; Thompson, K.; Walter, P.; Wilson, M.; Yen, A. S.; Webb, S.

2016-12-01

MapX will provide elemental imaging at ≤100 µm spatial resolution over 2.5 X 2.5 cm areas, yielding elemental chemistry at or below the scale length where many relict physical, chemical, and biological features can be imaged and interpreted in ancient rocks. MapX is a full-frame spectroscopic imager positioned on soil or regolith with touch sensors. During an analysis, an X-ray source (tube or radioisotope) bombards the sample surface with X-rays or α-particles / γ-rays, resulting in sample X-ray Fluorescence (XRF). Fluoresced X-rays pass through an X-ray lens (X-ray µ-Pore Optic, "MPO") that projects a spatially resolved image of the X-rays onto a CCD. The CCD is operated in single photon counting mode so that the positions and energies of individual photons are retained. In a single analysis, several thousand frames are stored and processed. A MapX experiment provides elemental maps having a spatial resolution of ≤100 µm and quantitative XRF spectra from Regions of Interest (ROI) 2 cm ≤ x ≤ 100 µm. ROI are compared with known rock and mineral compositions to extrapolate the data to rock types and putative mineralogies. The MapX geometry is being refined with ray-tracing simulations and with synchrotron experiments at SLAC. Source requirements are being determined through Monte Carlo modeling and experiment using XMIMSIM [1], GEANT4 [2] and PyMca [3] and a dedicated XRF test fixture. A flow-down of requirements for both tube and radioisotope sources is being developed from these experiments. In addition to Mars lander and rover missions, MapX could be used for landed science on other airless bodies (Phobos/Deimos, Comet nucleus, asteroids, the Earth's moon, and the icy satellites of the outer planets, including Europa. [1] Schoonjans, T. et al.(2012). Spectrachim. Acta Part B, 70, 10-23. [2] Agostinelli, S. et al. (2003). Nucl. Instr. and Methods in Phys. Research A, 506, 250-303. [3] V.A. Solé et al. (2007). Spectrochim. Acta Part B, 62, 63-68.

VizieR Online Data Catalog: New gamma-ray blazar candidates in the 3PBC (Maselli+, 2013)

NASA Astrophysics Data System (ADS)

Maselli, A.; Massaro, F.; Cusumano, G.; D'Abrusco, R.; La Parola, V.; Paggi, A.; Segreto, A.; Smith, H. A.; Tosti, G.

2013-06-01

We searched for γ-ray blazar candidates among the 382 unidentified hard X-ray sources of the third Palermo BAT Catalog (3PBC) obtained from the analysis of 66 months of Swift Burst Alert Telescope (BAT) survey data and listing 1586 sources. We adopted a recently developed association method based on the peculiar infrared colors that characterize the γ-ray blazars included in the second catalog of active galactic nuclei detected by the Fermi Large Area Telescope. We used this method exploiting the data of the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) to establish correspondences between unidentified 3PBC sources and WISE γ-ray blazar candidates located within the BAT positional uncertainty region at a 99% confidence level. We obtained a preliminary list of candidates for which we analyzed all the available data in the Swift archive to complement the information in the literature and in the radio, infrared, and optical catalogs with the information on their optical-UV and soft X-ray emission. Requiring the presence of radio and soft X-ray counterparts consistent with the infrared positions of the selected WISE sources, as well as a blazar-like radio morphology, we finally obtained a list of 24 γ-ray blazar candidates. (2 data files).

Gas gun shock experiments with single-pulse x-ray phase contrast imaging and diffraction at the Advanced Photon Source

NASA Astrophysics Data System (ADS)

Luo, S. N.; Jensen, B. J.; Hooks, D. E.; Fezzaa, K.; Ramos, K. J.; Yeager, J. D.; Kwiatkowski, K.; Shimada, T.

2012-07-01

The highly transient nature of shock loading and pronounced microstructure effects on dynamic materials response call for in situ, temporally and spatially resolved, x-ray-based diagnostics. Third-generation synchrotron x-ray sources are advantageous for x-ray phase contrast imaging (PCI) and diffraction under dynamic loading, due to their high photon fluxes, high coherency, and high pulse repetition rates. The feasibility of bulk-scale gas gun shock experiments with dynamic x-ray PCI and diffraction measurements was investigated at the beamline 32ID-B of the Advanced Photon Source. The x-ray beam characteristics, experimental setup, x-ray diagnostics, and static and dynamic test results are described. We demonstrate ultrafast, multiframe, single-pulse PCI measurements with unprecedented temporal (<100 ps) and spatial (˜2 μm) resolutions for bulk-scale shock experiments, as well as single-pulse dynamic Laue diffraction. The results not only substantiate the potential of synchrotron-based experiments for addressing a variety of shock physics problems, but also allow us to identify the technical challenges related to image detection, x-ray source, and dynamic loading.

Characterisation of a MeV Bremsstrahlung x-ray source produced from a high intensity laser for high areal density object radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Courtois, C.; Compant La Fontaine, A.; Bazzoli, S.

2013-08-15

Results of an experiment to characterise a MeV Bremsstrahlung x-ray emission created by a short (<10 ps) pulse, high intensity (1.4 × 10{sup 19} W/cm{sup 2}) laser are presented. X-ray emission is characterized using several diagnostics; nuclear activation measurements, a calibrated hard x-ray spectrometer, and dosimeters. Results from the reconstructed x-ray energy spectra are consistent with numerical simulations using the PIC and Monte Carlo codes between 0.3 and 30 MeV. The intense Bremsstrahlung x-ray source is used to radiograph an image quality indicator (IQI) heavily filtered with thick tungsten absorbers. Observations suggest that internal features of the IQI can bemore » resolved up to an external areal density of 85 g/cm{sup 2}. The x-ray source size, inferred by the radiography of a thick resolution grid, is estimated to be approximately 400 μm (full width half maximum of the x-ray source Point Spread Function)« less

DTRA National Ignition Facility (NIF)

DTIC Science & Technology

2009-01-16

might provide a capability closer to that of UGT ‟s, particularly in the 15-100 keV X-ray band. We conclude that DRTA should monitor developments in...presently be tested. This is because, since the cessation of underground tests ( UGT ‟s), available facilities cannot produce X-ray environments of...provide a capability closer to that of UGT ‟s, particularly in the 15-100 keV X-ray band. However, source characteristics, including the level of

The X-Ray Globular Cluster Population in NGC 1399

NASA Technical Reports Server (NTRS)

Angelini, Lorella; Loewenstein, Michael; Mushotzky, Richard F.; White, Nicholas E. (Technical Monitor)

2001-01-01

We report on X-ray sources detected in the Chandra images of the elliptical galaxy NGC 1399 and identified with globular clusters (GCs). The 8'x 8' Chandra image shows that a large fraction of the 2-10 keV X-ray emission is resolved into point sources, with a luminosity threshold of 5 x 10 (exp 37) ergs s-1. These sources are most likely Low Mass X-ray Binaries (LMXBs). More than 70% of the X-ray sources, in a region imaged by Hubble Space Telescope (HST), are located within GCs. Many of these sources have super-Eddington luminosity (for an accreting neutron star) and their average luminosity is higher than the remaining sources. This association suggests that, in giant elliptical galaxies, luminous X-ray binaries preferentially form in GCs. The spectral properties of the GC and non-GC sources are in most cases similar to those of LMXBs in our galaxy. Two of the brightest sources, one of which is in GC, have a much softer spectra as seen in the high state black hole. The "apparent" super-Eddington luminosity in many cases may be due to multiple LMXB systems within individual GC, but with some of the most extreme luminous systems containing massive black holes.

Miniature x-ray source

DOEpatents

Trebes, James E.; Bell, Perry M.; Robinson, Ronald B.

2000-01-01

A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

600 eV falcon-linac thomson x-ray source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crane, J K; LeSage, G P; Ditmire, T

2000-12-15

The advent of 3rd generation light sources such as the Advanced Light Source (ALS) at LBL, and the Advanced Photon Source at Argonne, have produced a revolution in x-ray probing of dense matter during the past decade. These machines use electron-synchrotrons in conjunction with undulator stages to produce 100 psec x-ray pulses with photon energies of several kiloelectronvolts (keV). The applications for x-ray probing of matter are numerous and diverse with experiments in medicine and biology, semiconductors and materials science, and plasma and solid state physics. In spite of the success of the 3rd generation light sources there is strongmore » motivation to push the capabilities of x-ray probing into new realms, requiring shorter pulses, higher brightness and harder x-rays. A 4th generation light source, the Linac Coherent Light Source (LCLS), is being considered at the Stanford Linear Accelerator [1]. The LCLS will produce multi-kilovolt x-rays of subpicosecond duration that are 10 orders of magnitude brighter than today's 3rd generation light sources.[1] Although the LCLS will provide unprecedented capability for performing time-resolved x-ray probing of ultrafast phenomena at solid densities, this machine will not be completed for many years. In the meantime there is a serious need for an ultrashort-pulse, high-brightness, hard x-ray source that is capable of probing deep into high-Z solid materials to measure dynamic effects that occur on picosecond time scales. Such an instrument would be ideal for probing the effects of shock propagation in solids using Bragg and Laue diffraction. These techniques can be used to look at phase transitions, melting and recrystallization, and the propagation of defects and dislocations well below the surface in solid materials. [2] These types of dynamic phenomena undermine the mechanical properties of metals and are of general interest in solid state physics, materials science, metallurgy, and have specific relevance to stockpile stewardship. Another x-ray diagnostic technique, extended x-ray absorption fine structure (EXAFS) spectroscopy, can be used to measure small-scale structural changes to understand the underlying atomic physics associated with the formation of defects. [2]« less

Medical X-ray sources now and for the future

NASA Astrophysics Data System (ADS)

Behling, Rolf

2017-11-01

This paper focuses on the use of X-rays in their largest field of application: medical diagnostic imaging and image-guided therapy. For this purpose, vacuum electronics in the form of X-ray tubes as the source of bremsstrahlung (braking radiation) have been the number one choice for X-ray production in the range of photon energies between about 16 keV for mammography and 150 keV for general radiography. Soft tissue on one end and bony structures on the other are sufficiently transparent and the contrast delivered by difference of absorption is sufficiently high for this spectral range. The dominance of X-ray tubes holds even more than 120 years after Conrad Roentgen's discovery of the bremsstrahlung mechanism. What are the specifics of current X-ray tubes and their medical diagnostic applications? How may the next available technology at or beyond the horizon look like? Can we hope for substantial game changers? Will flat panel sources, less expensive X-ray "LED's", compact X-ray Lasers, compact synchrotrons or equivalent X-ray sources appear in medical diagnostic imaging soon? After discussing the various modalities of imaging systems and their sources of radiation, this overview will briefly touch on the physics of bremsstrahlung generation, key characteristics of X-ray tubes, and material boundary conditions, which restrict performance. It will discuss the deficits of the bremsstrahlung technology and try to sketch future alternatives and their prospects of implementation in medical diagnostics.

THE IDENTIFICATION OF THE X-RAY COUNTERPART TO PSR J2021+4026

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weisskopf, Martin C.; Elsner, Ronald F.; O'Dell, Stephen L.

2011-12-10

We report the probable identification of the X-ray counterpart to the {gamma}-ray pulsar PSR J2021+4026 using imaging with the Chandra X-ray Observatory Advanced CCD Imaging Spectrometer and timing analysis with the Fermi satellite. Given the statistical and systematic errors, the positions determined by both satellites are coincident. The X-ray source position is R.A. 20{sup h}21{sup m}30.{sup s}733, decl. +40 Degree-Sign 26'46.''04 (J2000) with an estimated uncertainty of 1.''3 combined statistical and systematic error. Moreover, both the X-ray to {gamma}-ray and the X-ray to optical flux ratios are sensible assuming a neutron star origin for the X-ray flux. The X-ray sourcemore » has no cataloged infrared-to-visible counterpart and, through new observations, we set upper limits to its optical emission of i' > 23.0 mag and r' > 25.2 mag. The source exhibits an X-ray spectrum with most likely both a power law and a thermal component. We also report on the X-ray and visible light properties of the 43 other sources detected in our Chandra observation.« less

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

NASA Technical Reports Server (NTRS)

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

1985-01-01

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

An extended superhot solar flare X-ray source

NASA Technical Reports Server (NTRS)

Hudson, H. S.; Ohki, K. I.; Tsuneta, S.

1985-01-01

A superhot hard X-ray source in a solar flare occulted by the solar limb was identified. Its hard X-ray image was found to show great horizontal extent but little vertical extent. An H alpha brightening at the same limb position about an hour later suggests a multi-component loop prominence system, so that it appears that a superhot source can evolve in the same manner as a normal solar soft X-ray source. The assignment of plausiable values to physical parameters in the source suggests (from the simplest form of classical thermal-conduction theory) that either new physics will be required to suppress conduction, or else that gradual energy release well after the impulsive phase of the flare must occur. In this respect too, the superhot source appears to resemble ordinary soft X-ray sources, except of course that its temperature is higher.

The X-ray morphology of the relaxed cluster of galaxies A2256. II - Sources around the extended cluster emission

NASA Technical Reports Server (NTRS)

Henry, J. P.; Briel, U. G.

1991-01-01

The X-ray observation of A2256 with the imaging proportional counter on board the X-ray observatory Rosat revealed significantly more sources in the field around the extended cluster emission than expected by chance. In a preliminary investigation, 14 sources were discovered at the limiting flux for this exposure whereas about 7 sources would have been expected by chance. At least two of those sources are coincident with cluster-member galaxies, having X-ray luminosities of approximately 10 to the 42nd erg/s in the Rosat energy band from 0.1 to 2.4 keV, but at least four more are from 'dark' objects. The similarity of these objects to those in A1367 suggests the existence of a new class of X-ray sources in clusters.

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.

A Deep Chandra ACIS Survey of M83

NASA Astrophysics Data System (ADS)

Long, Knox S.; Kuntz, Kip D.; Blair, William P.; Godfrey, Leith; Plucinsky, Paul P.; Soria, Roberto; Stockdale, Christopher; Winkler, P. Frank

2014-06-01

We have obtained a series of deep X-ray images of the nearby galaxy M83 using Chandra, with a total exposure of 729 ks. Combining the new data with earlier archival observations totaling 61 ks, we find 378 point sources within the D25 contour of the galaxy. We find 80 more sources, mostly background active galactic nuclei (AGNs), outside of the D25 contour. Of the X-ray sources, 47 have been detected in a new radio survey of M83 obtained using the Australia Telescope Compact Array. Of the X-ray sources, at least 87 seem likely to be supernova remnants (SNRs), based on a combination of their properties in X-rays and at other wavelengths. We attempt to classify the point source population of M83 through a combination of spectral and temporal analysis. As part of this effort, we carry out an initial spectral analysis of the 29 brightest X-ray sources. The soft X-ray sources in the disk, many of which are SNRs, are associated with the spiral arms, while the harder X-ray sources, mostly X-ray binaries (XRBs), do not appear to be. After eliminating AGNs, foreground stars, and identified SNRs from the sample, we construct the cumulative luminosity function (CLF) of XRBs brighter than 8 × 1035 erg s-1. Despite M83's relatively high star formation rate, the CLF indicates that most of the XRBs in the disk are low mass XRBs. Based on observations made with NASA's Chandra X-Ray Observatory. NASA's Chandra Observatory is operated by Smithsonian Astrophysical Observatory under contract NAS83060 and the data were obtained through program GO1-12115.

Near-infrared counterparts to the Galactic Bulge Survey X-ray source population

NASA Astrophysics Data System (ADS)

Greiss, S.; Steeghs, D.; Jonker, P. G.; Torres, M. A. P.; Maccarone, T. J.; Hynes, R. I.; Britt, C. T.; Nelemans, G.; Gänsicke, B. T.

2014-03-01

We report on the near-infrared matches, drawn from three surveys, to the 1640 unique X-ray sources detected by Chandra in the Galactic Bulge Survey (GBS). This survey targets faint X-ray sources in the bulge, with a particular focus on accreting compact objects. We present all viable counterpart candidates and associate a false alarm probability (FAP) to each near-infrared match in order to identify the most likely counterparts. The FAP takes into account a statistical study involving a chance alignment test, as well as considering the positional accuracy of the individual X-ray sources. We find that although the star density in the bulge is very high, ˜90 per cent of our sources have an FAP <10 per cent, indicating that for most X-ray sources, viable near-infrared counterparts candidates can be identified. In addition to the FAP, we provide positional and photometric information for candidate counterparts to ˜95 per cent of the GBS X-ray sources. This information in combination with optical photometry, spectroscopy and variability constraints will be crucial to characterize and classify secure counterparts.

Surface slope metrology of highly curved x-ray optics with an interferometric microscope

NASA Astrophysics Data System (ADS)

Gevorkyan, Gevork S.; Centers, Gary; Polonska, Kateryna S.; Nikitin, Sergey M.; Lacey, Ian; Yashchuk, Valeriy V.

2017-09-01

The development of deterministic polishing techniques has given rise to vendors that manufacture high quality threedimensional x-ray optics. The surface metrology on these optics remains a difficult task. For the fabrication, vendors usually use unique surface metrology tools, generally developed on site, that are not available in the optical metrology labs at x-ray facilities. At the Advanced Light Source X-Ray Optics Laboratory, we have developed a rather straightforward interferometric-microscopy-based procedure capable of sub microradian characterization of sagittal slope variation of x-ray optics for two-dimensionally focusing and collimating (such as ellipsoids, paraboloids, etc.). In the paper, we provide the mathematical foundation of the procedure and describe the related instrument calibration. We also present analytical expression describing the ideal surface shape in the sagittal direction of a spheroid specified by the conjugate parameters of the optic's beamline application. The expression is useful when analyzing data obtained with such optics. The high efficiency of the developed measurement and data analysis procedures is demonstrated in results of measurements with a number of x-ray optics with sagittal radius of curvature between 56 mm and 480 mm. We also discuss potential areas of further improvement.

Diffraction based method to reconstruct the spectrum of the Thomson scattering x-ray source

NASA Astrophysics Data System (ADS)

Chi, Zhijun; Yan, Lixin; Zhang, Zhen; Zhou, Zheng; Zheng, Lianmin; Wang, Dong; Tian, Qili; Wang, Wei; Nie, Zan; Zhang, Jie; Du, Yingchao; Hua, Jianfei; Shi, Jiaru; Pai, Chihao; Lu, Wei; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

2017-04-01

As Thomson scattering x-ray sources based on the collision of intense laser and relativistic electrons have drawn much attention in various scientific fields, there is an increasing demand for the effective methods to reconstruct the spectrum information of the ultra-short and high-intensity x-ray pulses. In this paper, a precise spectrum measurement method for the Thomson scattering x-ray sources was proposed with the diffraction of a Highly Oriented Pyrolytic Graphite (HOPG) crystal and was demonstrated at the Tsinghua Thomson scattering X-ray source. The x-ray pulse is diffracted by a 15 mm (L) ×15 mm (H)× 1 mm (D) HOPG crystal with 1° mosaic spread. By analyzing the diffraction pattern, both x-ray peak energies and energy spectral bandwidths at different polar angles can be reconstructed, which agree well with the theoretical value and simulation. The higher integral reflectivity of the HOPG crystal makes this method possible for single-shot measurement.

Diffraction based method to reconstruct the spectrum of the Thomson scattering x-ray source.

PubMed

Chi, Zhijun; Yan, Lixin; Zhang, Zhen; Zhou, Zheng; Zheng, Lianmin; Wang, Dong; Tian, Qili; Wang, Wei; Nie, Zan; Zhang, Jie; Du, Yingchao; Hua, Jianfei; Shi, Jiaru; Pai, Chihao; Lu, Wei; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

2017-04-01

As Thomson scattering x-ray sources based on the collision of intense laser and relativistic electrons have drawn much attention in various scientific fields, there is an increasing demand for the effective methods to reconstruct the spectrum information of the ultra-short and high-intensity x-ray pulses. In this paper, a precise spectrum measurement method for the Thomson scattering x-ray sources was proposed with the diffraction of a Highly Oriented Pyrolytic Graphite (HOPG) crystal and was demonstrated at the Tsinghua Thomson scattering X-ray source. The x-ray pulse is diffracted by a 15 mm (L) ×15 mm (H)× 1 mm (D) HOPG crystal with 1° mosaic spread. By analyzing the diffraction pattern, both x-ray peak energies and energy spectral bandwidths at different polar angles can be reconstructed, which agree well with the theoretical value and simulation. The higher integral reflectivity of the HOPG crystal makes this method possible for single-shot measurement.

X-ray photonic microsystems for the manipulation of synchrotron light

DOE PAGES

Mukhopadhyay, D.; Walko, D. A.; Jung, I. W.; ...

2015-05-05

In this study, photonic microsystems played an essential role in the development of integrated photonic devices, thanks to their unique spatiotemporal control and spectral shaping capabilities. Similar capabilities to markedly control and manipulate X-ray radiation are highly desirable but practically impossible due to the massive size of the silicon single-crystal optics currently used. Here we show that micromechanical systems can be used as X-ray optics to create and preserve the spatial, temporal and spectral correlation of the X-rays. We demonstrate that, as X-ray reflective optics they can maintain the wavefront properties with nearly 100% reflectivity, and as a dynamic diffractivemore » optics they can generate nanosecond time windows with over 100-kHz repetition rates. Since X-ray photonic microsystems can be easily incorporated into lab-based and next-generation synchrotron X-ray sources, they bring unprecedented design flexibility for future dynamic and miniature X-ray optics for focusing, wavefront manipulation, multicolour dispersion, and pulse slicing.« less

A Chandra ACIS Study of 30 Doradus. II. X-Ray Point Sources in the Massive Star Cluster R136 and Beyond

NASA Astrophysics Data System (ADS)

Townsley, Leisa K.; Broos, Patrick S.; Feigelson, Eric D.; Garmire, Gordon P.; Getman, Konstantin V.

2006-04-01

We have studied the X-ray point-source population of the 30 Doradus (30 Dor) star-forming complex in the Large Magellanic Cloud using high spatial resolution X-ray images and spatially resolved spectra obtained with the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-Ray Observatory. Here we describe the X-ray sources in a 17'×17' field centered on R136, the massive star cluster at the center of the main 30 Dor nebula. We detect 20 of the 32 Wolf-Rayet stars in the ACIS field. The cluster R136 is resolved at the subarcsecond level into almost 100 X-ray sources, including many typical O3-O5 stars, as well as a few bright X-ray sources previously reported. Over 2 orders of magnitude of scatter in LX is seen among R136 O stars, suggesting that X-ray emission in the most massive stars depends critically on the details of wind properties and the binarity of each system, rather than reflecting the widely reported characteristic value LX/Lbol~=10-7. Such a canonical ratio may exist for single massive stars in R136, but our data are too shallow to confirm this relationship. Through this and future X-ray studies of 30 Dor, the complete life cycle of a massive stellar cluster can be revealed.

Emission Mechanisms in X-Ray Faint Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Brown, B. A.; Bregman, J. N.

1999-12-01

To understand the X-ray emission in normal elliptical galaxies, it is important to determine the relative contributions of hot interstellar gas and discrete sources to the observed emission. In X-ray luminous ellipticals, a hot gaseous component dominates the emission from X-ray binaries and other discrete sources. It is expected that, as one looks toward lower X-ray luminous galaxies, that the hot gas will contribute less to the overall X-ray emission and that discrete sources will supply most, if not all of, the observed X-ray emission. Here we examine ROSAT HRI and PSPC data for seventeen optically bright (BT < 11.15) elliptical galaxies with log(LX/L_B) < 29.7 ergs s-1/L⊙ . Radial surface brightness profiles are modeled with a modified King beta model and a de Vaucouleurs r1/4 law (similar to a beta = 0.5 beta model). For galaxy profiles where the two models are easily distinguishable, the models are combined, and fit to the data to determine or set upper limits to the discrete source contribution. The modeled data suggest that X-ray faint elliptical galaxies may still retain a sizable fraction of hot gas, but that emission from discrete sources are a significant component of the total observed X-ray emission. Support for this project has been provided by NASA and the National Academy of Sciences.

Status of the laboratory infrastructure for detector calibration and characterization at the European XFEL

NASA Astrophysics Data System (ADS)

Raab, N.; Ballak, K.-E.; Dietze, T.; Ekmedzič, M.; Hauf, S.; Januschek, F.; Kaukher, A.; Kuster, M.; Lang, P. M.; Münnich, A.; Schmitt, R.; Sztuk-Dambietz, J.; Turcato, M.

2016-12-01

The European X-ray Free Electron Laser (XFEL.EU) will provide unprecedented peak brilliance and ultra-short and spatially coherent X-ray pulses in an energy range of 0.25 to 25 keV . The pulse timing structure is unique with a burst of 2700 pulses of 100 fs length at a temporal distance of 220 ns followed by a 99.4 ms gap. To make optimal use of this timing structure and energy range a great variety of detectors are being developed for use at XFEL.EU, including 2D X-ray imaging cameras that are able to detect images at a rate of 4.5 MHz, provide dynamic ranges up to 105 photons per pulse per pixel under different operating conditions and covering a large range of angular resolution \\cite{requirements,Markus}. In order to characterize, commission and calibrate this variety of detectors and for testing of detector prototypes the XFEL.EU detector group is building up an X-ray test laboratory that allows testing of detectors with X-ray photons under conditions that are as similar to the future beam line conditions at the XFEL.EU as is possible with laboratory sources [1]. A total of four test environments provide the infrastructure for detector tests and calibration: two portable setups that utilize low power X-ray sources and radioactive isotopes, a test environment where a commercial high power X-ray generator is in use, and a pulsed X-ray/electron source which will provide pulses as short as 25 ns in XFEL.EU burst mode combined with target anodes of different materials. The status of the test environments, three of which are already in use while one is in commissioning phase, will be presented as well as first results from performance tests and characterization of the sources.

Astronomy and Cancer Research: X-Rays and Nanotechnology from Black Holes to Cancer Therapy

NASA Astrophysics Data System (ADS)

Pradhan, Anil K.; Nahar, Sultana N.

It seems highly unlikely that any connection is to be found between astronomy and medicine. But then it also appears to be obvious: X-rays. However, that is quite superficial because the nature of X-rays in the two disciplines is quite different. Nevertheless, we describe recent research on exactly that kind of link. Furthermore, the linkage lies in atomic physics, and via spectroscopy which is a vital tool in astronomy and may also be equally valuable in biomedical research. This review begins with the physics of black hole environments as viewed through X-ray spectroscopy. It is then shown that similar physics can be applied to spectroscopic imaging and therapeutics using heavy-element (high-Z) moieties designed to target cancerous tumors. X-ray irradiation of high-Z nanomaterials as radiosensitizing agents should be extremely efficient for therapy and diagnostics (theranostics). However, broadband radiation from conventional X-ray sources (such as CT scanners) results in vast and unnecessary radiation exposure. Monochromatic X-ray sources are expected to be considerably more efficient. We have developed a new and comprehensive methodology—Resonant Nano-Plasma Theranostics (RNPT)—that encompasses the use of monochromatic X-ray sources and high-Z nanoparticles. Ongoing research entails theoretical computations, numerical simulations, and in vitro and in vivo biomedical experiments. Stemming from basic theoretical studies of Kα resonant photoabsorption and fluorescence in all elements of the Periodic Table, we have established a comprehensive multi-disciplinary program involving researchers from physics, chemistry, astronomy, pathology, radiation oncology and radiology. Large-scale calculations necessary for theory and modeling are done at a variety of computational platforms at the Ohio Supercomputer Center. The final goal is the implementation of RNPT for clinical applications.

TRANSIENT X-RAY SOURCE POPULATION IN THE MAGELLANIC-TYPE GALAXY NGC 55

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jithesh, V.; Wang, Zhongxiang, E-mail: jithesh@shao.ac.cn

2016-04-10

We present the spectral and temporal properties of 15 candidate transient X-ray sources detected in archival XMM-Newton and Chandra observations of the nearby Magellanic-type, SB(s)m galaxy NGC 55. Based on an X-ray color classification scheme, the majority of the sources may be identified as X-ray binaries (XRBs), and six sources are soft, including a likely supernova remnant. We perform a detailed spectral and variability analysis of the data for two bright candidate XRBs. Both sources displayed strong short-term X-ray variability, and their X-ray spectra and hardness ratios are consistent with those of XRBs. These results, combined with their high X-raymore » luminosities (∼10{sup 38} erg s{sup −1}), strongly suggest that they are black hole (BH) binaries. Seven less luminous sources have spectral properties consistent with those of neutron star or BH XRBs in both normal and high-rate accretion modes, but one of them is the likely counterpart to a background galaxy (because of positional coincidence). From our spectral analysis, we find that the six soft sources are candidate super soft sources (SSSs) with dominant emission in the soft (0.3–2 keV) X-ray band. Archival Hubble Space Telescope optical images for seven sources are available, and the data suggest that most of them are likely to be high-mass XRBs. Our analysis has revealed the heterogeneous nature of the transient population in NGC 55 (six high-mass XRBs, one low-mass XRBs, six SSSs, one active galactic nucleus), helping establish the similarity of the X-ray properties of this galaxy to those of other Magellanic-type galaxies.« less

Einstein X-ray observations of M101

NASA Technical Reports Server (NTRS)

Trinchieri, G.; Fabbiano, G.; Romaine, S.

1990-01-01

The Einstein X-ray observations of the face-on spiral galaxy M101 are presented. The global X-ray luminosity L(x) of M101 is about 1.2 x 10 to the 40th ergs/s for D = 7.2 Mpc, consistent with the expected X-ray luminosity of normal spiral galaxies of its optical magnitude. The X-ray emission is mostly due to very luminous individual sources, with L(x) greater than 10 to the 38th ergs/s each, most likely very massive accreting binary systems. The data suggest a deficiency of sources in the luminosity range of L(x) from about 10 to the 37th to about 10 to the 38th ergs/s, which would indicate that the luminosity distribution of the X-ray sources in M101 might be different from that of M31 or M33.

Monitoring X-Ray Emission from X-Ray Bursters

NASA Technical Reports Server (NTRS)

Halpern, Jules P.; Kaaret, Philip

1999-01-01

The scientific goal of this project was to monitor a selected sample of x-ray bursters using data from the All-Sky Monitor (ASM) on the Rossi X-Ray Timing Explorer together with data from the Burst and Transient Source Experiment (BATSE) on the Compton Gamma-Ray Observatory to study the long-term temporal evolution of these sources in the x-ray and hard x-ray bands. The project was closely related to "Long-Term Hard X-Ray Monitoring of X-Ray Bursters", NASA project NAG5-3891, and and "Hard x-ray emission of x-ray bursters", NASA project NAG5-4633, and shares publications in common with both of these. The project involved preparation of software for use in monitoring and then the actual monitoring itself. These efforts have lead to results directly from the ASM data and also from Target of Opportunity Observations (TOO) made with the Rossi X-Ray Timing Explorer based on detection of transient hard x-ray outbursts with the ASM and BATSE.

A highly sensitive x-ray imaging modality for hepatocellular carcinoma detection in vitro

NASA Astrophysics Data System (ADS)

Rand, Danielle; Walsh, Edward G.; Derdak, Zoltan; Wands, Jack R.; Rose-Petruck, Christoph

2015-01-01

Innovations that improve sensitivity and reduce cost are of paramount importance in diagnostic imaging. The novel x-ray imaging modality called spatial frequency heterodyne imaging (SFHI) is based on a linear arrangement of x-ray source, tissue, and x-ray detector, much like that of a conventional x-ray imaging apparatus. However, SFHI rests on a complete paradigm reversal compared to conventional x-ray absorption-based radiology: while scattered x-rays are carefully rejected in absorption-based x-ray radiology to enhance the image contrast, SFHI forms images exclusively from x-rays scattered by the tissue. In this study we use numerical processing to produce x-ray scatter images of hepatocellular carcinoma labeled with a nanoparticle contrast agent. We subsequently compare the sensitivity of SFHI in this application to that of both conventional x-ray imaging and magnetic resonance imaging (MRI). Although SFHI is still in the early stages of its development, our results show that the sensitivity of SFHI is an order of magnitude greater than that of absorption-based x-ray imaging and approximately equal to that of MRI. As x-ray imaging modalities typically have lower installation and service costs compared to MRI, SFHI could become a cost effective alternative to MRI, particularly in areas of the world with inadequate availability of MRI facilities.

Non-Destructive Characterization of Engineering Materials Using High-Energy X-rays at the Advanced Photon Source

DOE PAGES

Park, Jun-Sang; Okasinski, John; Chatterjee, Kamalika; ...

2017-05-30

High energy X-rays can penetrate large components and samples made from engineering alloys. Brilliant synchrotron sources like the Advanced Photon Source (APS) combined with unique experimental setups are increasingly allowing scientists and engineers to non-destructively characterize the state of materials across a range of length scales. In this article, some of the new developments at the APS, namely the high energy diffraction microscopy technique for grain-by-grain maps and aperture-based techniques for aggregate maps, are described.

Non-Destructive Characterization of Engineering Materials Using High-Energy X-rays at the Advanced Photon Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jun-Sang; Okasinski, John; Chatterjee, Kamalika

High energy X-rays can penetrate large components and samples made from engineering alloys. Brilliant synchrotron sources like the Advanced Photon Source (APS) combined with unique experimental setups are increasingly allowing scientists and engineers to non-destructively characterize the state of materials across a range of length scales. In this article, some of the new developments at the APS, namely the high energy diffraction microscopy technique for grain-by-grain maps and aperture-based techniques for aggregate maps, are described.

Unusual Black Hole Binary LMC X-3: A Transient High-Mass X-Ray Binary That Is Almost Always On?

NASA Technical Reports Server (NTRS)

Torpin, Trevor J.; Boyd, Patricia T.; Smale, Alan P.; Valencic, Lynne A.

2017-01-01

We have analyzed a rich, multimission, multiwavelength data set from the black hole X-ray binary (BHXB) LMC X-3, covering a new anomalous low state (ALS), during which the source flux falls to an unprecedentedly low and barely detectable level, and a more normal low state. Simultaneous X-ray and UV/optical monitoring data from Swift are combined with pointed observations from the Rossi X-ray Timing Explorer (RXTE) and X-ray Multi- Mirror Mission (XMM-Newton) and light curves from the Monitor of All-Sky X-ray Image (MAXI) instrument to compare the source characteristics during the ALS with those seen during the normal low state. An XMM-Newton spectrum obtained during the ALS can be modeled using an absorbed power law with Gamma = 1.41‚+/- 0.65 and a luminosity of 7.97 x 10(exp 33) erg/s (0.6-5 keV). The Swift X-ray and UV light curves indicate an X-ray lag of approx. 8 days as LMC X-3 abruptly exits the ALS, suggesting that changes in the mass accretion rate from the donor drive the X-ray lag. The normal low state displays an asymmetric profile in which the exit occurs more quickly than the entry, with minimum X-ray flux a factor of approx. 4300 brighter than during the ALS. The UV brightness of LMC X-3 in the ALS is also fainter and less variable than during normal low states. The existence of repeated ALSs in LMC X-3, as well as a comparison with other BHXBs, implies that it is very close to the transient/persistent X-ray source dividing line. We conclude that LMC X-3 is a transient source that is almost always "on."

Development of XAFS Into a Structure Determination Technique

NASA Astrophysics Data System (ADS)

Stern, E. A.

After the detection of diffraction of x-rays by M. Laue in 1912, the technique was soon applied to structure determination by Bragg within a year. On the other hand, although the edge steps in X-Ray absorption were discovered even earlier by Barkla and both the near edge (XANES) and extended X-Ray fine structure (EXAFS) past the edge were detected by 1929, it still took over 40 years to realize the structure information contained in this X-Ray absorption fine structure (XAFS). To understand this delay a brief historical review of the development of the scientific ideas that transformed XAFS into the premiere technique for local structure determination is given. The development includes both advances in theoretical understanding and calculational capabilities, and in experimental facilities, especially synchrotron radiation sources. The present state of the XAFS technique and its capabilities are summarized.

X-Pinch And Its Applications In X-ray Radiograph

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zou Xiaobing; Wang Xinxin; Liu Rui

2009-07-07

An X-pinch device and the related diagnostics of x-ray emission from X-pinch were briefly described. The time-resolved x-ray measurements with photoconducting diodes show that the x-ray pulse usually consists of two subnanosecond peaks with a time interval of about 0.5 ns. Being consistent with these two peaks of the x-ray pulse, two point x-ray sources of size ranging from 100 mum to 5 mum and depending on cut-off x-ray photon energy were usually observed on the pinhole pictures. The x-pinch was used as x-ray source for backlighting of the electrical explosion of single wire and the evolution of X-pinch, andmore » for phase-contrast imaging of soft biological objects such as a small shrimp and a mosquito.« less

High-resolution radio and X-ray observations of the supernova remnant W28

NASA Technical Reports Server (NTRS)

Andrews, M. D.; Basart, J. P.; Lamb, R. C.; Becker, R. H.

1983-01-01

The present study has the objective to report the first high resolution radio and X-ray observations of the central part of the galactic supernova remnant, W28, taking into account the possible association of the remnant with the unidentified gamma-ray source, 2CG 006-00. This gamma-ray source is approximately two-thirds as bright as the Crab pulsar above 100 MeV, and has a somewhat flatter spectrum. Both the radio and X-ray observations reveal previously unknown aspects of W28 which support the possibility of W28 being a gamma-ray source. The radio data show a flat-spectrum, nonthermal component reminiscent of the Crab Nebula and Vela, both of which are confirmed gamma-ray sources. The X-ray observations reveal a compact source within W28, again suggestive of both the Crab and Vela. If the similarities among W28, the Crab Nebula, and the Vela remnant are valid, the gamma-ray source 2CG 00-00 should be studied for periodicity, the conclusive signature of a compact source of emission.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mascali, David, E-mail: davidmascali@lns.infn.it; Castro, Giuseppe; Celona, Luigi

2016-02-15

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

A View through a Bamboo Screen: From Moire Patterns to Black Holes.

ERIC Educational Resources Information Center

Oda, Minoru

1992-01-01

Describes the genesis, the early experiments, and the limitations of X-ray astronomy. Discusses original methods for searching and locating the first interstellar X-ray source, modern attempts to identify a massive black hole as part of a binary system X-ray source, and the effort to generate X-ray images of solar flares. (JJK)

POLIX: A Thomson X-ray polarimeter for a small satellite mission

NASA Astrophysics Data System (ADS)

Paul, Biswajit; Gopala Krishna, M. R.; Puthiya Veetil, Rishin

2016-07-01

POLIX is a Thomson X-ray polarimeter for a small satellite mission of ISRO. The instrument consists of a collimator, a scatterer and a set proportional counters to detect the scattered X-rays. We will describe the design, specifications, sensitivity, and development status of this instrument and some of the important scientific goals. This instrument will provide unprecedented opportunity to measure X-ray polarisation in the medium energy range in a large number of sources of different classes with a minimum detectable linear polarisation degree of 2-3%. The prime objects for observation with this instrument are the X-ray bright accretion powered neutron stars, accreting black holes in different spectral states, rotation powered pulsars, magnetars, and active galactic nuclei. This instrument will be a bridge between the soft X-ray polarimeters and the Compton polarimeters.

Variable soft X-ray excesses in active galactic nuclei from nonthermal electron-positron pair cascades

NASA Technical Reports Server (NTRS)

Zdziarski, Andrzej A.; Coppi, Paolo S.

1991-01-01

In the present study of the formation of steep soft X-ray excesses that are superposed on flatter, hard X-ray power-law spectra in nonthermal electron-positron pair cascade sources, the soft excess in pair-cascade AGN models appears as a steep power law superposed on the tail of the UV bump and the flat nonthermal (hard X-ray) power law. The model-parameter space in which an excess in soft X-rays is visible is ascertained, and the time-variability of soft excesses in pair cascade models is examined. It is established that the parameter space in which soft excesses appear encompasses the range of preferred input parameters for a recently development Compton reflection model of UV and X-ray emission from the central engine of an AGN.

Simulation tools for analyzer-based x-ray phase contrast imaging system with a conventional x-ray source

NASA Astrophysics Data System (ADS)

Caudevilla, Oriol; Zhou, Wei; Stoupin, Stanislav; Verman, Boris; Brankov, J. G.

2016-09-01

Analyzer-based X-ray phase contrast imaging (ABI) belongs to a broader family of phase-contrast (PC) X-ray imaging modalities. Unlike the conventional X-ray radiography, which measures only X-ray absorption, in PC imaging one can also measures the X-rays deflection induced by the object refractive properties. It has been shown that refraction imaging provides better contrast when imaging the soft tissue, which is of great interest in medical imaging applications. In this paper, we introduce a simulation tool specifically designed to simulate the analyzer-based X-ray phase contrast imaging system with a conventional polychromatic X-ray source. By utilizing ray tracing and basic physical principles of diffraction theory our simulation tool can predicting the X-ray beam profile shape, the energy content, the total throughput (photon count) at the detector. In addition we can evaluate imaging system point-spread function for various system configurations.

a-Si:H TFT-silicon hybrid low-energy x-ray detector

DOE PAGES

Shin, Kyung -Wook; Karim, Karim S.

2017-03-15

Direct conversion crystalline silicon X-ray imagers are used for low-energy X-ray photon (4-20 keV) detection in scientific research applications such as protein crystallography. In this paper, we demonstrate a novel pixel architecture that integrates a crystalline silicon X-ray detector with a thin-film transistor amorphous silicon pixel readout circuit. We describe a simplified two-mask process to fabricate a complete imaging array and present preliminary results that show the fabricated pixel to be sensitive to 5.89-keV photons from a low activity Fe-55 gamma source. Furthermore, this paper presented can expedite the development of high spatial resolution, low cost, direct conversion imagers formore » X-ray diffraction and crystallography applications.« less

X-ray transmission microscope development

NASA Astrophysics Data System (ADS)

Kaukler, William F.; Rosenberger, Franz E.

1995-08-01

This report covers the third 6 month period, from February 28, 1995 to August 31, 1995, under this contract. The main efforts during this period were the construction of the X-ray furnace, evaluation and selection of the CCD technology for the X-ray camera, solidification experiments with Al alloys and Al-zirconia composites in the prototype furnace, evaluation of specimens for the particle pushing flight experiment - PEPSI, measurements of emitted spectra from X-ray source, testing of the high resolution X-ray test targets, and the establishment of criteria for and selection of peripheral equipment. In addition to these tasks, two presentations were prepared in this period; one for the AIAA Microgravity Symposium and another for the Gordon Conference on Gravitational Effects in Pyisico-Chemical Systems.

X-ray transmission microscope development

NASA Technical Reports Server (NTRS)

Kaukler, William F.; Rosenberger, Franz E.

1995-01-01

This report covers the third 6 month period, from February 28, 1995 to August 31, 1995, under this contract. The main efforts during this period were the construction of the X-ray furnace, evaluation and selection of the CCD technology for the X-ray camera, solidification experiments with Al alloys and Al-zirconia composites in the prototype furnace, evaluation of specimens for the particle pushing flight experiment - PEPSI, measurements of emitted spectra from X-ray source, testing of the high resolution X-ray test targets, and the establishment of criteria for and selection of peripheral equipment. In addition to these tasks, two presentations were prepared in this period; one for the AIAA Microgravity Symposium and another for the Gordon Conference on Gravitational Effects in Pyisico-Chemical Systems.

Identification of the Hard X-Ray Source Dominating the E > 25 keV Emission of the Nearby Galaxy M31

NASA Technical Reports Server (NTRS)

Yukita, M.; Ptak, A.; Hornschemeier, A. E.; Wik, D.; Maccarone, T.J.; Pottschmidt, Katja; Zezas, A.; Antoniou, V.; Ballhausen, R.; Lehmer, B.D.;

Identification of the Hard X-Ray Source Dominating the E > 25 keV Emission of the Nearby Galaxy M31

NASA Technical Reports Server (NTRS)

Yukita, M.; Ptak, A.; Hornschemeier, A. E.; Wik, D.; Maccarone, T. J.; Pottschmidt, K.; Zezas, A.; Antoniou, V.; Ballhausen, R.; Lehmer, B. D.;

Dynamic evolution of the source volumes of gradual and impulsive solar flare emissions

NASA Technical Reports Server (NTRS)

Bruner, M. E.; Crannell, C. J.; Goetz, F.; Magun, A.; Mckenzie, D. L.

1987-01-01

This study compares flare source volumes inferred from impulsive hard X-rays and microwaves with those derived from density sensitive soft X-ray line ratios in the O VII spectrum. The data for this study were obtained with the SMM Hard X-Ray Burst Spectrometer, Earth-based radio observatories, and the SOLEX-B spectrometer on the P78-1 satellite. Data were available for the flares of 1980 April 8, 1980 May 9, and 1981 February 26. The hard X-ray/microwave source volume is determined under the assumption that the same electron temperature or power law index characterizes both the source of hard X-rays and the source of microwaves. The O VII line ratios yield the density and volume of the 2 X 10 to the 6th K plasma. For all three flares, the O VII source volume is found to be smallest at the beginning of the flare, near the time when the impulsive hard X-ray/microwave volume reaches its first maximum. At this time, the O VII volume is three to four orders of magnitude smaller than that inferred from the hard X-ray/microwave analysis. Subsequently, the O VII source volume increases by one or two orders of magnitude then remains almost constant until the end of the flare when it apparently increases again.

Low-mass X-ray binary MAXI J1421-613 observed by MAXI GSC and Swift XRT

NASA Astrophysics Data System (ADS)

Serino, Motoko; Shidatsu, Megumi; Ueda, Yoshihiro; Matsuoka, Masaru; Negoro, Hitoshi; Yamaoka, Kazutaka; Kennea, Jamie A.; Fukushima, Kosuke; Nagayama, Takahiro

2015-04-01

Monitor of All sky X-ray Image (MAXI) discovered a new outburst of an X-ray transient source named MAXI J1421-613. Because of the detection of three X-ray bursts from the source, it was identified as a neutron star low-mass X-ray binary. The results of data analyses of the MAXI GSC (Gas Slit Camera) and the Swift XRT (X-Ray Telescope) follow-up observations suggest that the spectral hardness remained unchanged during the first two weeks of the outburst. All the XRT spectra in the 0.5-10 keV band can be well explained by thermal Comptonization of multi-color disk blackbody emission. The photon index of the Comptonized component is ≈ 2, which is typical of low-mass X-ray binaries in the low/hard state. Since X-ray bursts have a maximum peak luminosity, it is possible to estimate the (maximum) distance from its observed peak flux. The peak flux of the second X-ray burst, which was observed by the GSC, is about 5 photons cm-2 s-1. By assuming a blackbody spectrum of 2.5 keV, the maximum distance to the source is estimated as 7 kpc. The position of this source is contained by the large error regions of two bright X-ray sources detected with Orbiting Solar Observatory-7 (OSO-7) in the 1970s. Besides this, no past activities at the XRT position are reported in the literature. If MAXI J1421-613 is the same source as (one of) these, the outburst observed with MAXI may have occurred after a quiescence of 30-40 years.

The Hard X-ray Imager (HXI) for the ASTRO-H Mission

NASA Astrophysics Data System (ADS)

Sato, Goro; Kokubun, Motohide; Nakazawa, Kazuhiro; Enoto, Teruaki; Fukazawa, Yasushi; Harayama, Atsushi; Hayashi, Katsuhiro; Kataoka, Jun; Katsuta, Junichiro; Kawaharada, Madoka; Laurent, Philippe; Lebrun, François; Limousin, Olivier; Makishima, Kazuo; Mizuno, Tsunefumi; Mori, Kunishiro; Nakamori, Takeshi; Noda, Hirofumi; Odaka, Hirokazu; Ohno, Masanori; Ohta, Masayuki; Saito, Shinya; Sato, Rie; Tajima, Hiroyasu; Takahashi, Hiromitsu; Takahashi, Tadayuki; Takeda, Shinichiro; Terada, Yukikatsu; Uchiyama, Hideki; Uchiyama, Yasunobu; Watanabe, Shin; Yamaoka, Kazutaka; Yatsu, Yoichi; Yuasa, Takayuki

2014-07-01

The 6th Japanese X-ray satellite, ASTRO-H, is scheduled for launch in 2015. The hard X-ray focusing imaging system will observe astronomical objects with the sensitivity for detecting point sources with a brightness of 1/100,000 times fainter than the Crab nebula at > 10 keV. The Hard X-ray Imager (HXI) is a focal plane detector 12 m below the hard X-ray telescope (HXT) covering the energy range from 5 to 80 keV. The HXI is composed of a stacked Si/CdTe semiconductor detector module and surrounding BGO scintillators. The latter work as active shields for efficient reduction of background events caused by cosmic-ray particles, cosmic X-ray background, and in-orbit radiation activation. In this paper, we describe the detector system, and present current status of flight model development, and performance of HXI using an engineering model of HXI.

Modulated method for efficient, narrow-bandwidth, laser Compton X-ray and gamma-ray sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barty, Christopher P. J.

A method of x-ray and gamma-ray generation via laser Compton scattering uses the interaction of a specially-formatted, highly modulated, long duration, laser pulse with a high-frequency train of high-brightness electron bunches to both create narrow bandwidth x-ray and gamma-ray sources and significantly increase the laser to Compton photon conversion efficiency.

Method for efficient, narrow-bandwidth, laser compton x-ray and gamma-ray sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barty, Christopher P. J.

A method of x-ray and gamma-ray generation via laser Compton scattering uses the interaction of a specially-formatted, highly modulated, long duration, laser pulse with a high-frequency train of high-brightness electron bunches to both create narrow bandwidth x-ray and gamma-ray sources and significantly increase the laser to Compton photon conversion efficiency.

IDENTIFICATION OF A POPULATION OF X-RAY-EMITTING MASSIVE STARS IN THE GALACTIC PLANE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, Gemma E.; Gaensler, B. M.; Kaplan, David L.

2011-02-01

We present X-ray, infrared, optical, and radio observations of four previously unidentified Galactic plane X-ray sources: AX J163252-4746, AX J184738-0156, AX J144701-5919, and AX J144547-5931. Detection of each source with the Chandra X-ray Observatory has provided sub-arcsecond localizations, which we use to identify bright infrared counterparts to all four objects. Infrared and optical spectroscopy of these counterparts demonstrate that all four X-ray sources are extremely massive stars, with spectral classifications: Ofpe/WN9 (AX J163252-4746), WN7 (AX J184738-0156 = WR121a), WN7-8h (AX J144701-5919), and OIf{sup +} (AX J144547-5931). AX J163252-4746 and AX J184738-0156 are both luminous, hard, X-ray emitters with strong Femore » XXV emission lines in their X-ray spectra at {approx}6.7 keV. The multi-wavelength properties of AX J163252-4746 and AX J184738-0156 are not consistent with isolated massive stars or accretion onto a compact companion; we conclude that their X-ray emission is most likely generated in a colliding-wind binary (CWB) system. For both AX J144701-5919 and AX J144547-5931, the X-ray emission is an order of magnitude less luminous and with a softer spectrum. These properties are consistent with a CWB interpretation for these two sources also, but other mechanisms for the generation of X-rays cannot be excluded. There are many other as yet unidentified X-ray sources in the Galactic plane, with X-ray properties similar to those seen for AX J163252-4746, AX J184738-0156, AX J144701-5919, and AX J144547-5931. This may indicate a substantial population of X-ray-emitting massive stars and CWBs in the Milky Way.« less

Putting tools in the toolbox: Development of a free, open-source toolbox for quantitative image analysis of porous media.

NASA Astrophysics Data System (ADS)

Iltis, G.; Caswell, T. A.; Dill, E.; Wilkins, S.; Lee, W. K.

2014-12-01

X-ray tomographic imaging of porous media has proven to be a valuable tool for investigating and characterizing the physical structure and state of both natural and synthetic porous materials, including glass bead packs, ceramics, soil and rock. Given that most synchrotron facilities have user programs which grant academic researchers access to facilities and x-ray imaging equipment free of charge, a key limitation or hindrance for small research groups interested in conducting x-ray imaging experiments is the financial cost associated with post-experiment data analysis. While the cost of high performance computing hardware continues to decrease, expenses associated with licensing commercial software packages for quantitative image analysis continue to increase, with current prices being as high as $24,000 USD, for a single user license. As construction of the Nation's newest synchrotron accelerator nears completion, a significant effort is being made here at the National Synchrotron Light Source II (NSLS-II), Brookhaven National Laboratory (BNL), to provide an open-source, experiment-to-publication toolbox that reduces the financial and technical 'activation energy' required for performing sophisticated quantitative analysis of multidimensional porous media data sets, collected using cutting-edge x-ray imaging techniques. Implementation focuses on leveraging existing open-source projects and developing additional tools for quantitative analysis. We will present an overview of the software suite that is in development here at BNL including major design decisions, a demonstration of several test cases illustrating currently available quantitative tools for analysis and characterization of multidimensional porous media image data sets and plans for their future development.

Hard X-ray imaging from Explorer

NASA Technical Reports Server (NTRS)

Grindlay, J. E.; Murray, S. S.

1981-01-01

Coded aperture X-ray detectors were applied to obtain large increases in sensitivity as well as angular resolution. A hard X-ray coded aperture detector concept is described which enables very high sensitivity studies persistent hard X-ray sources and gamma ray bursts. Coded aperture imaging is employed so that approx. 2 min source locations can be derived within a 3 deg field of view. Gamma bursts were located initially to within approx. 2 deg and X-ray/hard X-ray spectra and timing, as well as precise locations, derived for possible burst afterglow emission. It is suggested that hard X-ray imaging should be conducted from an Explorer mission where long exposure times are possible.

Unusual Black Hole Binary LMC X-3: A Transient High-mass X-Ray Binary That Is Almost Always On?

NASA Astrophysics Data System (ADS)

Torpin, Trevor J.; Boyd, Patricia T.; Smale, Alan P.; Valencic, Lynne A.

2017-11-01

We have analyzed a rich, multimission, multiwavelength data set from the black hole X-ray binary (BHXB) LMC X-3, covering a new anomalous low state (ALS), during which the source flux falls to an unprecedentedly low and barely detectable level, and a more normal low state. Simultaneous X-ray and UV/optical monitoring data from Swift are combined with pointed observations from the Rossi X-ray Timing Explorer (RXTE) and X-ray Multi-Mirror Mission (XMM-Newton) and light curves from the Monitor of All-Sky X-ray Image (MAXI) instrument to compare the source characteristics during the ALS with those seen during the normal low state. An XMM-Newton spectrum obtained during the ALS can be modeled using an absorbed power law with {{Γ }}=1.41+/- 0.65 and a luminosity of 7.97× {10}33 erg s-1 (0.6-5 keV). The Swift X-ray and UV light curves indicate an X-ray lag of ˜8 days as LMC X-3 abruptly exits the ALS, suggesting that changes in the mass accretion rate from the donor drive the X-ray lag. The normal low state displays an asymmetric profile in which the exit occurs more quickly than the entry, with minimum X-ray flux a factor of ˜4300 brighter than during the ALS. The UV brightness of LMC X-3 in the ALS is also fainter and less variable than during normal low states. The existence of repeated ALSs in LMC X-3, as well as a comparison with other BHXBs, implies that it is very close to the transient/persistent X-ray source dividing line. We conclude that LMC X-3 is a transient source that is almost always “on.”

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.

X-ray emission from the Pleiades cluster

NASA Technical Reports Server (NTRS)

Agrawal, P. C.; Singh, K. P.; Riegler, G. R.

1983-01-01

The detection and identification of H0344+24, a new X-ray source located in the Pleiades cluster, is reported, based on observations made with HEAO A-2 low-energy detector 1 in the 0.15-3.0-keV energy band in August, 1977. The 90-percent-confidence error box for the new source is centered at 03 h 44.1 min right ascension (1950), near the center star of the 500-star Pleiades cluster, 25-eta-Tau. Since no likely galactic or extragalactic source of X-rays was found in a catalog search of the error-box region, identification of the source with the Pleiades cluster is considered secure. X-ray luminosity of the source is calculated to be about 10 to the 32nd ergs/sec, based on a distance of 125 pc. The X-ray characteristics of the Pleiades stars are discussed, and it is concluded that H0344+24 can best be explained as the integrated X-ray emission of all the B and F stars in the cluster.

Discovery of low-redshift X-ray selected quasars - New clues to the QSO phenomenon

NASA Technical Reports Server (NTRS)

Grindlay, J. E.; Forman, W. R.; Steiner, J. E.; Canizares, C. R.; Mcclintock, J. E.

1980-01-01

The identification of six X-ray sources discovered by the Einstein Observatory with X-ray quasars is reported, and the properties of these X-ray selected quasars are discussed. The four high-latitude fields of 1 sq deg each in which the Einstein imaging proportional counter detected serendipitous X-ray sources at intermediate exposures of 10,000 sec were observed by 4-m and 1.5-m telescopes, and optical sources with uv excesses and emission line spectra typical of many low-redshift quasars and Seyfert 1 galaxies were found within the 1-arcsec error boxes of the X-ray sources. All six quasars identified were found to be radio quiet, with low redshift and relatively faint optical magnitudes, and to be similar in space density, colors and magnitude versus redshift relation to an optically selected sample at the same mean magnitude. X-ray luminosity was found to be well correlated with both continuum and broad-line emission luminosities for the known radio-quiet quasars and Seyfert 1 galaxies, and it was observed that the five objects with the lowest redshifts have very similar X-ray/optical luminosity ratios despite tenfold variations in X-ray luminosity. It is concluded that photoionization by a continuum extending to X-ray energies is the dominant excitation mechanism in radio-quiet quasars.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

E.H. Seabury; D.L. Chichester; A.J. Caffrey

2001-08-01

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

The Columbia University proton-induced soft x-ray microbeam.

PubMed

Harken, Andrew D; Randers-Pehrson, Gerhard; Johnson, Gary W; Brenner, David J

2011-09-15

A soft x-ray microbeam using proton-induced x-ray emission (PIXE) of characteristic titanium (K(α) 4.5 keV) as the x-ray source has been developed at the Radiological Research Accelerator Facility (RARAF) at Columbia University. The proton beam is focused to a 120 μm × 50 μm spot on the titanium target using an electrostatic quadrupole quadruplet previously used for the charged particle microbeam studies at RARAF. The proton induced x-rays from this spot project a 50 μm round x-ray generation spot into the vertical direction. The x-rays are focused to a spot size of 5 μm in diameter using a Fresnel zone plate. The x-rays have an attenuation length of (1/e length of ~145 μm) allowing more consistent dose delivery across the depth of a single cell layer and penetration into tissue samples than previous ultra soft x-ray systems. The irradiation end station is based on our previous design to allow quick comparison to charged particle experiments and for mixed irradiation experiments.

Time-dependent nonequilibrium soft x-ray response during a spin crossover

DOE Office of Scientific and Technical Information (OSTI.GOV)

van Veenendaal, Michel

The rapid development of high-brilliance pulsed X-ray sources with femtosecond time resolution has created a need for a better theoretical understanding of the time-dependent soft-X-ray response of dissipative many-body quantum systems. It is demonstrated how soft-X-ray spectroscopies, such as X-ray absorption and resonant inelastic X-ray scattering at transition-metal L-edges, can provide insight into intersystem crossings, such as a spin crossover. The photoinduced doublet-to-quartet spin crossover on cobalt in Fe-Co Prussian blue analogues is used as an example to demonstrate how the X-ray response is affected by the dissipative nonequilibrium dynamics. The time-dependent soft-X-ray spectra provide a wealth of information thatmore » reflect the changes in the nonequilibrium initial state via continuously changing spectral lineshapes that cannot be decomposed into initial photoexcited and final metastable spectra, strong broadenings, a collapse of clear selection rules during the intersystem crossing, strong fluctuations in the isotropic branching ratio in X-ray absorption, and crystal-field collapse/oscillations and strongly time-dependent anti-Stokes processes in RIXS.« less

On The Nature of the Ultraluminous X-Ray Transient in Cen A (NGC 5128)

NASA Technical Reports Server (NTRS)

Ghosh, Kajal K.; Finger, Mark H.; Swartz, Douglas A.; Tennant, Allyn F.; Wu, Kinwah

2005-01-01

We combine 20 ROSAT, Chandra, and XMM-Newton observations of the Cen A galaxy to obtain the X-ray light curve of 1RXH J132519.8-430312 (=CXOU J132519.9-430317) spanning 1990 to 2003. The source reached a peak 0.1-2.4 keV flux F(sub X) > 10(exp -12) ergs/sq cm/s during a 10 day span in 1995 July. The inferred peak isotropic luminosity of the source therefore exceeded 3 x 10(exp 39) ergs/s, which places the source in the class of ultra-luminous X-ray sources. Coherent pulsations at 13.264 Hz are detected at the 3 sigma level during a second bright episode (F(sub x) > 3 x 10(exp -13) ergs/sq cm/s) in 1999 December. The source is detected and varies significantly within three additional observations but is below the detection threshold in 7 observations. The X-ray spectrum in 1999 December is best described as a cut-off power law or a disk-blackbody (multi-colored disk). We also detect an optical source, m(sub F555W) approx. 24.1 mag, within the Chandra error circle of 1RXH J132519.8-430312 in Hubble images taken 195 days before the nearest X-ray observation. The optical brightness of this source is consistent with a late O or early B star at the distance of Cen A. The X-ray and optical behavior of 1RXH J132519.8-430312 is therefore similar to the transient Be/X-ray pulsar A 0538-66.

APXS on board Chandrayaan-2 Rover

NASA Astrophysics Data System (ADS)

Shanmugam, M.; Sripada, V. S. Murty; Acharya, Y. B.; Goyal, S. K.

2012-07-01

Alpha Particle X-ray Spectrometer (APXS) is a well proven instrument for quantitative in situ elemental analysis of the planetary surfaces and has been successfully employed for Mars surface exploration. Chandrayaan-2, ISRO's second lunar mission having an Orbiter, Lander and Rover has provided an opportunity to explore the lunar surface with superior detectors such as Silicon Drift Detector (SDD) with energy resolution of about 150eV @ 5.9keV. The objective of the APXS instrument is to analyse several soil/rock samples along the rover traverse for the major elements with characteristic X-rays in 1 to 25keV range. The working principle of APXS involves measuring the intensity of characteristic X-rays emitted from the sample due to Alpha Particle Induced X-ray Emission (PIXE) and X-ray florescence (XRF) processes using suitable radioactive sources, allowing the determination of elements from Na to Br, spanning the energy range of 0.9 to 16keV. For this experiment ^{244}Cm radioactive source has been chosen which emits both Alpha particles (5.8MeV) and X-rays (14.1keV, 18keV). APXS uses six Alpha sources, each about 5mCi activity. Unlike Mars, lunar environment poses additional challenges due to the regolith and extreme surface temperature changes, to operate the APXS. Our APXS instrument consists of two packages namely APXS sensor head and APXS signal electronics. The sensor head assembly contains SDD, six alpha sources and front end electronic circuits such as preamplifier and shaper circuits and will be mounted on a robotic arm which on command brings the sensor head close to the lunar surface at a height of 35±10mm. SDD module to be used in the experiment has 30mm ^{2} active detector area with in-built peltier cooler and heat sink to maintain the detector at about -35°C. The detector is covered with 8 micron thick Be window which results in the low energy threshold of about 1keV. The size of the APXS sensor head is 70x70x70mm ^{3} (approx). APXS signal electronics consists of a PCB having digital, power and rover interface electronics circuits, which are housed inside the Warm Electronics Box (WEB) mounted under the rover chassis where the temperature is maintained between -50°C to +70°C. Presently, we have completed the design verification model of the APXS payload and engineering model of the payload is in progress. The developed system has been tested using laboratory X-ray sources and observed an energy resolution of about 150eV at 5.9keV when the detector is cooled to -35°C. We also carried out the detection of X-ray fluorescence for some of the USGS standards for a fixed geometry of detector, source and sample, using ^{55}Fe and ^{241}Am X-ray sources. It is shown that the count rate of a given peak varies linearly with the concentration of the corresponding element. The detailed developments and results will be discussed at the conference.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coppens, Philip; Fournier, Bertrand

Here, the need for data-scaling has become increasingly evident as time-resolved pump-probe photocrystallography is rapidly developing at high intensity X-ray sources. Several aspects of the scaling of data sets collected at synchrotrons, XFELs (X-ray Free Electron Lasers) and high-intensity pulsed electron sources are discussed. They include laser-ON/laser-OFF data scaling, inter- and intra-data set scaling. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

Breakthroughs in photonics 2013: X-ray optics

DOE PAGES

Soufli, Regina

2014-04-01

Here, this review discusses the latest advances in extreme ultraviolet/X-ray optics development, which are motivated by the availability and demands of new X-ray sources and scientific and industrial applications. Among the breakthroughs highlighted are the following: i) fabrication, metrology, and mounting technologies for large-area optical substrates with improved figure, roughness, and focusing properties; ii) multilayer coatings with especially optimized layer properties, achieving improved reflectance, stability, and out-of-band suppression; and iii) nanodiffractive optics with improved efficiency and resolution.

Development and calibration of mirrors and gratings for the Soft X-ray materials science beamline at the Linac Coherent Light Source free-electron laser

DOE PAGES

Soufli, Regina; Fernandez-Perea, Monica; Baker, Sherry L.; ...

2012-04-18

This article discusses the development and calibration of the x-ray reflective and diffractive elements for the Soft X-ray Materials Science (SXR) beamline of the Linac Coherent Light Source (LCLS) free-electron laser (FEL), designed for operation in the 500 – 2000 eV region. The surface topography of three Si mirror substrates and two Si diffraction grating substrates was examined by atomic force microscopy (AFM) and optical profilometry. The figure of the mirror substrates was also verified via surface slope measurements with a long trace profiler. A boron carbide (B 4C) coating especially optimized for the LCLS FEL conditions was deposited onmore » all SXR mirrors and gratings. Coating thickness uniformity of 0.14 nm root mean square (rms) across clear apertures extending to 205 mm length was demonstrated for all elements, as required to preserve the coherent wavefront of the LCLS source. The reflective performance of the mirrors and the diffraction efficiency of the gratings were calibrated at beamline 6.3.2 at the Advanced Light Source synchrotron. To verify the integrity of the nanometer-scale grating structure, the grating topography was examined by AFM before and after coating. This is to our knowledge the first time B 4C-coated diffraction gratings are demonstrated for operation in the soft x-ray region.« less

Report on the fifth workshop on synchrotron x ray lithography

NASA Astrophysics Data System (ADS)

Williams, G. P.; Godel, J. B.; Brown, G. S.; Liebmann, W.

Semiconductors comprise a greater part of the United States economy than the aircraft, steel, and automobile industries combined. In future the semiconductor manufacturing industry will be forced to switch away from present optical manufacturing methods in the early to mid 1990s. X ray lithography has emerged as the leading contender for continuing production below the 0.4 micron level. Brookhaven National Laboratory began a series of workshops on x ray lithography in 1986 to examine key issues and in particular to enable United States industry to take advantage of the technical base established in this field. Since accelerators provide the brightest sources for x ray lithography, most of the research and development to date has taken place at large accelerator-based research centers such as Brookhaven, the University of Wisconsin, and Stanford. The goals of this Fifth Brookhaven Workshop were to review progress and goals since the last workshop and to establish a blueprint for the future. The meeting focused on the exposure tool, that is, a term defined as the source plus beamline and stepper. In order to assess the appropriateness of schedules for the development of this tool, other aspects of the required technology such as masks, resists and inspection and repair were also reviewed. To accomplish this, two working groups were set up, one to review the overall aspects of x ray lithography and set a time frame, the other to focus on sources.

A Search for Hyperluminous X-Ray Sources in the XMM-Newton Source Catalog

NASA Astrophysics Data System (ADS)

Zolotukhin, I.; Webb, N. A.; Godet, O.; Bachetti, M.; Barret, D.

2016-02-01

We present a new method to identify luminous off-nuclear X-ray sources in the outskirts of galaxies from large public redshift surveys, distinguishing them from foreground and background interlopers. Using the 3XMM-DR5 catalog of X-ray sources and the SDSS DR12 spectroscopic sample of galaxies, with the help of this off-nuclear cross-matching technique, we selected 98 sources with inferred X-ray luminosities in the range 1041 < LX < 1044 erg s-1, compatible with hyperluminous X-ray objects (HLX). To validate the method, we verify that it allowed us to recover known HLX candidates such as ESO 243-49 HLX-1 and M82 X-1. From a statistical study, we conservatively estimate that up to 71 ± 11 of these sources may be foreground- or background sources, statistically leaving at least 16 that are likely to be HLXs, thus providing support for the existence of the HLX population. We identify two good HLX candidates and using other publicly available data sets, in particular the VLA FIRST in radio, UKIRT Infrared Deep Sky Survey in the near-infrared, GALEX in the ultraviolet and Canada-France-Hawaii Telescope Megacam archive in the optical, we present evidence that these objects are unlikely to be foreground or background X-ray objects of conventional types, e.g., active galactic nuclei, BL Lac objects, Galactic X-ray binaries, or nearby stars. However, additional dedicated X-ray and optical observations are needed to confirm their association with the assumed host galaxies and thus secure their HLX classification.

Talbot-Lau x-ray deflectometry phase-retrieval methods for electron density diagnostics in high-energy density experiments.

PubMed

Valdivia, Maria Pia; Stutman, Dan; Stoeckl, Christian; Mileham, Chad; Begishev, Ildar A; Bromage, Jake; Regan, Sean P

2018-01-10

Talbot-Lau x-ray interferometry uses incoherent x-ray sources to measure refraction index changes in matter. These measurements can provide accurate electron density mapping through phase retrieval. An adaptation of the interferometer has been developed in order to meet the specific requirements of high-energy density experiments. This adaptation is known as a moiré deflectometer, which allows for single-shot capabilities in the form of interferometric fringe patterns. The moiré x-ray deflectometry technique requires a set of object and reference images in order to provide electron density maps, which can be costly in the high-energy density environment. In particular, synthetic reference phase images obtained ex situ through a phase-scan procedure, can provide a feasible solution. To test this procedure, an object phase map was retrieved from a single-shot moiré image obtained from a plasma-produced x-ray source. A reference phase map was then obtained from phase-stepping measurements using a continuous x-ray tube source in a small laboratory setting. The two phase maps were used to retrieve an electron density map. A comparison of the moiré and phase-stepping phase-retrieval methods was performed to evaluate single-exposure plasma electron density mapping for high-energy density and other transient plasma experiments. It was found that a combination of phase-retrieval methods can deliver accurate refraction angle mapping. Once x-ray backlighter quality is optimized, the ex situ method is expected to deliver electron density mapping with improved resolution. The steps necessary for improved diagnostic performance are discussed.

The Massive Star-Forming Regions Omnibus X-Ray Catalog

NASA Astrophysics Data System (ADS)

Townsley, Leisa K.; Broos, Patrick S.; Garmire, Gordon P.; Bouwman, Jeroen; Povich, Matthew S.; Feigelson, Eric D.; Getman, Konstantin V.; Kuhn, Michael A.

2014-07-01

We present the Massive Star-forming Regions (MSFRs) Omnibus X-ray Catalog (MOXC), a compendium of X-ray point sources from Chandra/ACIS observations of a selection of MSFRs across the Galaxy, plus 30 Doradus in the Large Magellanic Cloud. MOXC consists of 20,623 X-ray point sources from 12 MSFRs with distances ranging from 1.7 kpc to 50 kpc. Additionally, we show the morphology of the unresolved X-ray emission that remains after the cataloged X-ray point sources are excised from the ACIS data, in the context of Spitzer and WISE observations that trace the bubbles, ionization fronts, and photon-dominated regions that characterize MSFRs. In previous work, we have found that this unresolved X-ray emission is dominated by hot plasma from massive star wind shocks. This diffuse X-ray emission is found in every MOXC MSFR, clearly demonstrating that massive star feedback (and the several-million-degree plasmas that it generates) is an integral component of MSFR physics.

Backscatter X-Ray Development for Space Vehicle Thermal Protection Systems

NASA Astrophysics Data System (ADS)

Bartha, Bence B.; Hope, Dale; Vona, Paul; Born, Martin; Corak, Tony

2011-06-01

The Backscatter X-Ray (BSX) imaging technique is used for various single sided inspection purposes. Previously developed BSX techniques for spray-on-foam insulation (SOFI) have been used for detecting defects in Space Shuttle External Tank foam insulation. The developed BSX hardware and techniques are currently being enhanced to advance Non-Destructive Evaluation (NDE) methods for future space vehicle applications. Various Thermal Protection System (TPS) materials were inspected using the enhanced BSX imaging techniques, investigating the capability of the method to detect voids and other discontinuities at various locations within each material. Calibration standards were developed for the TPS materials in order to characterize and develop enhanced BSX inspection capabilities. The ability of the BSX technique to detect both manufactured and natural defects was also studied and compared to through-transmission x-ray techniques. The energy of the x-ray, source to object distance, angle of x-ray, focal spot size and x-ray detector configurations were parameters playing a significant role in the sensitivity of the BSX technique to image various materials and defects. The image processing of the results also showed significant increase in the sensitivity of the technique. The experimental results showed BSX to be a viable inspection technique for space vehicle TPS systems.

Fast transient X-rays and gamma ray bursts - Are they stellar flares?

NASA Astrophysics Data System (ADS)

Rao, A. R.; Vahia, M. N.

Short period transient X-ray emissions (FTX) have been observed from several sources in the sky and the largest single group of objects identified with such sources are active stars: flare stars, and RS CVn binaries. The study of the number, source and flux distribution of the fast transient X-ray sources shows that all the FTX emission can be treated as flares in the interbinary regions of active stars. It is suggested that the FTX emission is a common feature of the gamma ray bursts (GRBs). The evidence for the similarity between the hard X-ray flares and GRBs is discussed, and the possibility that the gamma ray bursts are the impulsive precursors of FTX originating from active stars with large scale magnetic activity is examined.

Coded-aperture imaging of the Galactic center region at gamma-ray energies

NASA Technical Reports Server (NTRS)

Cook, Walter R.; Grunsfeld, John M.; Heindl, William A.; Palmer, David M.; Prince, Thomas A.

1991-01-01

The first coded-aperture images of the Galactic center region at energies above 30 keV have revealed two strong gamma-ray sources. One source has been identified with the X-ray source IE 1740.7 - 2942, located 0.8 deg away from the nucleus. If this source is at the distance of the Galactic center, it is one of the most luminous objects in the galaxy at energies from 35 to 200 keV. The second source is consistent in location with the X-ray source GX 354 + 0 (MXB 1728-34). In addition, gamma-ray flux from the location of GX 1 + 4 was marginally detected at a level consistent with other post-1980 measurements. No significant hard X-ray or gamma-ray flux was detected from the direction of the Galactic nucleus or from the direction of the recently discovered gamma-ray source GRS 1758-258.

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

PubMed

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

2013-05-01

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

Quasiperiodic oscillations in bright galactic-bulge X-ray sources

NASA Technical Reports Server (NTRS)

Lamb, F. K.; Shibazaki, N.; Alpar, M. A.; Shaham, J.

1985-01-01

Quasiperiodic oscillations with frequencies in the range 5-50 Hz have recently been discovered in X-rays from two bright galactic-bulge sources and Sco X-1. These sources are weakly magnetic neutron stars accreting from disks which the plasma is clumped. The interaction of the magnetosphere with clumps in the inner disk causes oscillations in the X-ray flux with many of the properties observed.

Advanced X-Ray Timing Array Mission: Conceptual Spacecraft Design Study

NASA Technical Reports Server (NTRS)

Hopkins, R. C.; Johnson, L.; Thomas, H. D.; Wilson-Hodge, C. A.; Baysinger, M.; Maples, C. D.; Fabisinski, L.L.; Hornsby, L.; Thompson, K. S.; Miernik, J. H.

2011-01-01

The Advanced X-Ray Timing Array (AXTAR) is a mission concept for submillisecond timing of bright galactic x-ray sources. The two science instruments are the Large Area Timing Array (LATA) (a collimated instrument with 2-50-keV coverage and over 3 square meters of effective area) and a Sky Monitor (SM), which acts as a trigger for pointed observations of x-ray transients. The spacecraft conceptual design team developed two spacecraft concepts that will enable the AXTAR mission: A minimal configuration to be launched on a Taurus II and a larger configuration to be launched on a Falcon 9 or similar vehicle.

New Directions in X-Ray Light Sources or Fiat Lux: what's under the dome and watching atoms with x-rays (LBNL Summer Lecture Series)

ScienceCinema

Falcone, Roger [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Univ. of California, Berkeley, CA (United States). Dept. of Physics

2018-05-04

Summer Lecture Series 2008: Molecular movies of chemical reactions and material phase transformations need a strobe of x-rays, the penetrating light that reveals how atoms and molecules assemble in chemical and biological systems and complex materials. Roger Falcone, Director of the Advanced Light Source,will discuss a new generation of x ray sources that will enable a new science of atomic dynamics on ultrafast timescales.

RELATIVISTIC THOMSON SCATTERING EXPERIMENT AT BNL - STATUS REPORT.

DOE Office of Scientific and Technical Information (OSTI.GOV)

POGORELSKY,I.V.; BEN ZVI,I.; KUSCHE,K.

2001-12-03

1.7 x 10{sup 8} x-ray photons per 3.5 ps pulse have been produced in Thomson scattering by focusing CO{sub 2} laser pulse on counter-propagating relativistic electron beam. We explore a possibility of further enhancement of process efficiency by propagating both beams in a plasma capillary. Conventional synchrotron light sources based on using giga-electron-volt electron synchrotron accelerators and magnetic wigglers generate x-ray radiation for versatile application in multi-disciplinary research. An intense laser beam causes relativistic electron oscillations similar to a wiggler. However, because the laser wavelength is thousand times shorter than a wiggler period, very moderate electron energy is needed tomore » produce hard x-rays via Thomson scattering. This allows using relatively compact mega-electron-volt linear accelerators instead of giga-electron-volt synchrotrons. Another important advantage of Thomson sources is a possibility to generate femtosecond x-ray pulses whereas conventional synchrotron sources have typically {approx}300 ps pulse duration. This promises to revolutionize x-ray research in chemistry, physics, and biology expanding it to ultra-fast processes. Thomson sources do not compete in repetition rate and average intensity with conventional light sources that operate at the megahertz frequency. However, Thomson sources have a potential to produce much higher photon numbers per pulse. This may allow developing a single shot exposure important for structural analysis of live biological objects. The BNL Thomson source is a user's experiment conducted at the Accelerator Test Facility since 1998 by an international collaboration in High Energy Physics. Since inception, the ATF source produces the record peak x-ray yield, intensity and brightness among other similar proof-of-principle demonstrations attempted elsewhere. Note that this result is achieved with a moderate laser power of 15 GW. A key to this achievement is in choosing right apparatus and efficient interaction geometry. We use a CO{sub 2} laser that delivers 10 times more photons per unit energy than the 1-{micro}m laser, a high-brightness linac, and the most energy-efficient backscattering interaction geometry. The purpose of this report is to give an update on new results obtained during this year and our near-term plans.« less

Facilities and Techniques for X-Ray Diagnostic Calibration in the 100-eV to 100-keV Energy Range

NASA Astrophysics Data System (ADS)

Gaines, J. L.; Wittmayer, F. J.

1986-08-01

The Lawrence Livermore National Laboratory (LLNL) has been a pioneer in the field of x-ray diagnostic calibration for more than 20 years. We have built steady state x-ray sources capable of supplying fluorescent lines of high spectral purity in the 100-eV to 100-keV energy range, and these sources have been used in the calibration of x-ray detectors, mirrors, crystals, filters, and film. This paper discusses our calibration philosophy and techniques, and describes some of our x-ray sources. Examples of actual calibration data are presented as well.

X-RAY SOURCES IN THE DWARF SPHEROIDAL GALAXY DRACO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sonbas, E.; Rangelov, B.; Kargaltsev, O.

2016-04-10

We present the spectral analysis of an 87 ks XMM-Newton observation of Draco, a nearby dwarf spheroidal galaxy. Of the approximately 35 robust X-ray source detections, we focus our attention on the brightest of these sources, for which we report X-ray and multiwavelength parameters. While most of the sources exhibit properties consistent with active galactic nuclei, few of them possess the characteristics of low-mass X-ray binaries (LMXBs) and cataclysmic variable (CVs). Our analysis places constraints on the population of X-ray sources with L{sub X} > 3 × 10{sup 33} erg s{sup −1} in Draco, suggesting that there are no actively accreting black hole andmore » neutron star binaries. However, we find four sources that could be quiescent state LMXBs/CVs associated with Draco. We also place constraints on the central black hole luminosity and on a dark matter decay signal around 3.5 keV.« less

Intensity-Modulated Advanced X-ray Source (IMAXS) for Homeland Security Applications

NASA Astrophysics Data System (ADS)

Langeveld, Willem G. J.; Johnson, William A.; Owen, Roger D.; Schonberg, Russell G.

2009-03-01

X-ray cargo inspection systems for the detection and verification of threats and contraband require high x-ray energy and high x-ray intensity to penetrate dense cargo. On the other hand, low intensity is desirable to minimize the radiation footprint. A collaboration between HESCO/PTSE Inc., Schonberg Research Corporation and Rapiscan Laboratories, Inc. has been formed in order to design and build an Intensity-Modulated Advanced X-ray Source (IMAXS). Such a source would allow cargo inspection systems to achieve up to two inches greater imaging penetration capability, while retaining the same average radiation footprint as present fixed-intensity sources. Alternatively, the same penetration capability can be obtained as with conventional sources with a reduction of the average radiation footprint by about a factor of three. The key idea is to change the intensity of the source for each x-ray pulse based on the signal strengths in the inspection system detector array during the previous pulse. In this paper we describe methods to accomplish pulse-to-pulse intensity modulation in both S-band (2998 MHz) and X-band (9303 MHz) linac sources, with diode or triode (gridded) electron guns. The feasibility of these methods has been demonstrated. Additionally, we describe a study of a shielding design that would allow a 6 MV X-band source to be used in mobile applications.

Beam Measurement of 11.424 GHz X-Band Linac for Compton Scattering X-ray Source

NASA Astrophysics Data System (ADS)

Natsui, Takuya; Mori, Azusa; Masuda, Hirotoshi; Uesaka, Mitsuru; Sakamoto, Fumito

2010-11-01

An inverse Compton scattering X-ray source for medical applications, consisting of an X-band (11.424 GHz) linac and Q-switched Nd:YAG laser, is currently being developed at the University of Tokyo. This system uses an X-band 3.5-cell thermionic cathode RF gun for electron beam generation. We can obtain a multi-bunch electron beam with this gun. The beam is accelerated to 30 MeV by a traveling-wave accelerating tube. So far, we have verified stable beam generation (around 2.3 MeV) by using the newly designed RF gun and we have succeeded in beam transportation to a beam dump.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1998-01-01

This is a computer rendering of the fully developed Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF). In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the renmants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-ray such as exploding stars, matter falling into black holes, and other exotic celestial objects. The Observatory has three major parts: (1) the x-ray telescope, whose mirrors will focus x-rays from celestial objects; (2) the science instruments that record the x-rays so that x-ray images can be produced and analyzed; and (3) the spacecraft, which provides the environment necessary for the telescope and the instruments to work. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1995-01-14

This is an artist's concept of the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), fully developed in orbit in a star field with Earth. In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the renmants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-ray such as exploding stars, matter falling into black holes, and other exotic celestial objects. The Observatory has three major parts: (1) the x-ray telescope, whose mirrors will focus x-rays from celestial objects; (2) the science instruments that record the x-rays so that x-ray images can be produced and analyzed; and (3) the spacecraft, which provides the environment necessary for the telescope and the instruments to work. TRW, Inc. was the prime contractor for the development the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1999-01-01

This is a computer rendering of the fully developed Chandra X-ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), in orbit in a star field. In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the renmants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-rays such as exploding stars, matter falling into black holes, and other exotic celestial objects. The Observatory has three major parts: (1) the x-ray telescope, whose mirrors will focus x-rays from celestial objects; (2) the science instruments that record the x-rays so that x-ray images can be produced and analyzed; and (3) the spacecraft, which provides the environment necessary for the telescope and the instruments to work. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW).

Simulation study of enhancing laser-driven multi-keV line-radiation through application of external magnetic fields

NASA Astrophysics Data System (ADS)

Kemp, G. Elijah; Colvin, J. D.; Fournier, K. B.; May, M. J.; Barrios, M. A.; Patel, M. V.; Koning, J. M.; Scott, H. A.; Marinak, M. M.

2015-11-01

Laser-driven, spectrally tailored, high-flux x-ray sources have been developed over the past decade for testing the radiation hardness of materials used in various civilian, space and military applications. The optimal electron temperatures for these x-ray sources occur around twice the desired photon energy. At the National Ignition Facility (NIF) laser, the available energy can produce plasmas with ~ 10keV electron temperatures which result in highly-efficient ~ 5keV radiation but less than optimal emission from the > 10keV sources. In this work, we present a possible venue for enhancing multi-keV x-ray emission on existing laser platforms through the application of an external magnetic field. Preliminary radiation-hydrodynamics calculations with Hydra suggest as much as 2 - 14 × increases in laser-to-x-ray conversion efficiency for 22 - 68keV K-shell sources are possible on the NIF laser - without any changes in laser-drive conditions - through the application of an external axial 50 T field. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

X-ray stars observed in LAMOST spectral survey

NASA Astrophysics Data System (ADS)

Lu, Hong-peng; Zhang, Li-yun; Han, Xianming L.; Shi, Jianrong

2018-05-01

X-ray stars have been studied since the beginning of X-ray astronomy. Investigating and studying the chromospheric activity from X-ray stellar optical spectra is highly significant in providing insights into stellar magnetic activity. The big data of LAMOST survey provides an opportunity for researching stellar optical spectroscopic properties of X-ray stars. We inferred the physical properties of X-ray stellar sources from the analysis of LAMOST spectra. First, we cross-matched the X-ray stellar catalogue (12254 X-ray stars) from ARXA with LAMOST data release 3 (DR3), and obtained 984 good spectra from 713 X-ray sources. We then visually inspected and assigned spectral type to each spectrum and calculated the equivalent width (EW) of Hα line using the Hammer spectral typing facility. Based on the EW of Hα line, we found 203 spectra of 145 X-ray sources with Hα emission above the continuum. For these spectra we also measured the EWs of Hβ, Hγ, Hδ and Ca ii IRT lines of these spectra. After removing novae, planetary nebulae and OB-type stars, we found there are 127 X-ray late-type stars with Hα line emission. By using our spectra and results from the literature, we found 53 X-ray stars showing Hα variability; these objects are Classical T Tauri stars (CTTs), cataclysmic variables (CVs) or chromospheric activity stars. We also found 18 X-ray stars showing obvious emissions in the Ca ii IRT lines. Of the 18 X-ray stars, 16 are CTTs and 2 are CVs. Finally, we discussed the relationships between the EW of Hα line and X-ray flux.

Performance summary on a high power dense plasma focus x-ray lithography point source producing 70 nm line features in AlGaAs microcircuits

NASA Astrophysics Data System (ADS)

Petr, Rodney; Bykanov, Alexander; Freshman, Jay; Reilly, Dennis; Mangano, Joseph; Roche, Maureen; Dickenson, Jason; Burte, Mitchell; Heaton, John

2004-08-01

A high average power dense plasma focus (DPF), x-ray point source has been used to produce ˜70 nm line features in AlGaAs-based monolithic millimeter-wave integrated circuits (MMICs). The DPF source has produced up to 12 J per pulse of x-ray energy into 4π steradians at ˜1 keV effective wavelength in ˜2 Torr neon at pulse repetition rates up to 60 Hz, with an effective x-ray yield efficiency of ˜0.8%. Plasma temperature and electron concentration are estimated from the x-ray spectrum to be ˜170 eV and ˜5.1019 cm-3, respectively. The x-ray point source utilizes solid-state pulse power technology to extend the operating lifetime of electrodes and insulators in the DPF discharge. By eliminating current reversals in the DPF head, an anode electrode has demonstrated a lifetime of more than 5 million shots. The x-ray point source has also been operated continuously for 8 h run times at 27 Hz average pulse recurrent frequency. Measurements of shock waves produced by the plasma discharge indicate that overpressure pulses must be attenuated before a collimator can be integrated with the DPF point source.

X-ray Studies of Unidentified Galactic TeV Gamma-ray Sources

NASA Astrophysics Data System (ADS)

Pühlhofer, Gerd

2009-05-01

Many of the recently discovered Galactic TeV sources remain unidentified to date. A large fraction of the sources is possibly associated with relic pulsar wind nebula (PWN) systems. One key question here is the maximum energy (beyond TeV) attained in the compact PWNe. Hard X-ray emission can trace those particles, but current non-focussing X-ray instruments above 10 keV have difficulties to deconvolve the hard pulsar spectrum from its surrounding nebula. Some of the new TeV sources are also expected to originate from middle-aged and possibly even from old supernova remnants (SNR). But no compelling case for such an identification has been found yet. In established young TeV-emitting SNRs, X-ray imaging above 10 keV could help to disentangle the leptonic from the hadronic emission component in the TeV shells, if secondary electrons produced in hadronic collisions can be effectively detected. As SNRs get older, the high energy electron component is expected to fade away. This may allow to verify the picture through X-ray spectral evolution of the source population. Starting from the lessons we have learned so far from X-ray follow-up observations of unidentified TeV sources, prospects for Simbol-X to resolve open questions in this field will be discussed.

Active x-ray optics for Generation-X, the next high resolution x-ray observatory

NASA Astrophysics Data System (ADS)

Elvis, Martin; Brissenden, R. J.; Fabbiano, G.; Schwartz, D. A.; Reid, P.; Podgorski, W.; Eisenhower, M.; Juda, M.; Phillips, J.; Cohen, L.; Wolk, S.

2006-06-01

X-rays provide one of the few bands through which we can study the epoch of reionization, when the first galaxies, black holes and stars were born. To reach the sensitivity required to image these first discrete objects in the universe needs a major advance in X-ray optics. Generation-X (Gen-X) is currently the only X-ray astronomy mission concept that addresses this goal. Gen-X aims to improve substantially on the Chandra angular resolution and to do so with substantially larger effective area. These two goals can only be met if a mirror technology can be developed that yields high angular resolution at much lower mass/unit area than the Chandra optics, matching that of Constellation-X (Con-X). We describe an approach to this goal based on active X-ray optics that correct the mid-frequency departures from an ideal Wolter optic on-orbit. We concentrate on the problems of sensing figure errors, calculating the corrections required, and applying those corrections. The time needed to make this in-flight calibration is reasonable. A laboratory version of these optics has already been developed by others and is successfully operating at synchrotron light sources. With only a moderate investment in these optics the goals of Gen-X resolution can be realized.

The Discovery of a Second Luminous Low Mass X-ray Binary in the Globular Cluster M15

NASA Technical Reports Server (NTRS)

White, Nicholas E.; Angelini, Lorella

2001-01-01

We report an observation by the Chandra X-ray Observatory of 4U2127+119, the X-ray source identified with the globular cluster M15. The Chandra observation reveals that 4U2127+119 is in fact two bright sources, separated by 2.7". One source is associated with AC21 1, the previously identified optical counterpart to 4U2127+119, a low mass X-ray binary (LMXB). The second source, M15-X2, is coincident with a 19th U magnitude blue star that is 3.3" from the cluster core. The Chandra count rate of M15-X2 is 2.5 times higher than that of AC211. Prior to the 0.5" imaging capability of Chandra the presence of two so closely separated bright sources would not have been resolved, The optical counterpart, X-ray luminosity and spectrum of M15-X2 are consistent with it also being an LMXB system. This is the first time that two LMXBS have been seen to be simultaneously active in a globular cluster. The discovery of a second active LMXB in M15 solves a long standing puzzle where the properties of AC211 appear consistent with it being dominated by an extended accretion disk corona, and yet 4U2127+119 also shows luminous X-ray bursts requiring that the neutron star be directly visible. The resolution of 4U2127+119 into two sources suggests that the X-ray bursts did not come from AC211, but rather from M15X2. We discuss the implications of this discovery for understanding the origin and evolution of LMXBs in GCs as well as X-ray observations of globular clusters in nearby galaxies.

The Discovery of a Second Luminous Low-Mass X-Ray Binary in the Globular Cluster M15

NASA Technical Reports Server (NTRS)

White, Nicholas E.; Angelini, Lorella

2001-01-01

We report an observation by the Chandra X-Ray Observatory of 4U 2127+119, the X-ray source identified with the globular cluster M15. The Chandra observation reveals that 4U 2127+119 is in fact two bright sources, separated by 2.7 arcsec. One source is associated with AC 211, the previously identified optical counterpart to 4U 2127+119, a low-mass X-ray binary (LMXB). The second source, M15 X-2, is coincident with a 19th U magnitude blue star that is 3.3 arcsec from the cluster core. The Chandra count rate of M15 X-2 is 2.5 times higher than that of AC 211. Prior to the 0.5 arcsec imaging capability of Chandra, the presence of two so closely separated bright sources would not have been resolved. The optical counterpart, X-ray luminosity, and spectrum of M15 X-2 are consistent with it also being an LMXB system. This is the first time that two LMXBs have been seen to be simultaneously active in a globular cluster. The discovery of a second active LMXB in M15 solves a long-standing puzzle where the properties of AC 211 appear consistent with it being dominated by an extended accretion disk corona, and yet 4U 2127+119 also shows luminous X-ray bursts requiring that the neutron star be directly visible. The resolution of 4U 2127+119 into two sources suggests that the X-ray bursts did not come from AC 211 but rather from M15 X-2. We discuss the implications of this discovery for understanding the origin and evolution of LMXBs in globular clusters as well as X-ray observations of globular clusters in nearby galaxies.

Evaluation of the Effect of Source Geometry on the Output of Miniature X-ray Tube for Electronic Brachytherapy through Simulation

PubMed Central

Barati, B.; Zabihzadeh, M.; Tahmasebi Birgani, M.J.; Chegini, N.; Fatahiasl, J.; Mirr, I.

2018-01-01

Objective: The use of miniature X-ray source in electronic brachytherapy is on the rise so there is an urgent need to acquire more knowledge on X-ray spectrum production and distribution by a dose. The aim of this research was to investigate the influence of target thickness and geometry at the source of miniature X-ray tube on tube output. Method: Five sources were simulated based on problems each with a specific geometric structure and conditions using MCNPX code. Tallies proportional to the output were used to calculate the results for the influence of source geometry on output. Results: The results of this work include the size of the optimal thickness of 5 miniature sources, energy spectrum of the sources per 50 kev and also the axial and transverse dose of simulated sources were calculated based on these thicknesses. The miniature source geometric was affected on the output x-ray tube. Conclusion: The result of this study demonstrates that hemispherical-conical, hemispherical and truncated-conical miniature sources were determined as the most suitable tools. PMID:29732338

The atmospheric structures of the companion stars of eclipsing binary x ray sources

NASA Technical Reports Server (NTRS)

Clark, George W.

1992-01-01

This investigation was aimed at determining structural features of the atmospheres of the massive early-type companion stars of eclipse x-ray pulsars by measurement of the attenuation of the x-ray spectrum during eclipse transitions and in deep eclipse. Several extended visits were made to ISAS in Japan by G. Clark and his graduate student, Jonathan Woo to coordinate the Ginga observations and preliminary data reduction, and to work with the Japanese host scientist, Fumiaki Nagase, in the interpretation of the data. At MIT extensive developments were made in software systems for data interpretation. In particular, a Monte Carlo code was developed for a 3-D simulation of the propagation of x-rays from the neutron star through the ionized atmosphere of the companion. With this code it was possible to determine the spectrum of Compton-scattered x-rays in deep eclipse and to subtract that component from the observed spectra, thereby isolating the software component that is attributable in large measure to x-rays that have been scattered by interstellar grains. This research has culminated in the submission of paper to the Astrophysical Journal on the determination of properties of the atmosphere of QV Nor, the BOI companion of 4U 1538-52, and the properties of interstellar dust grains along the line of sight from the source. The latter results were an unanticipated byproduct of the investigation. Data from Ginga observations of the Magellanic binaries SMC X-1 and LMC X-4 are currently under investigation as the PhD thesis project of Jonathan Woo who anticipated completion in the spring of 1993.

The Chandra Deep Field-North Survey and the cosmic X-ray background.

PubMed

Brandt, W Nielsen; Alexander, David M; Bauer, Franz E; Hornschemeier, Ann E

2002-09-15

Chandra has performed a 1.4 Ms survey centred on the Hubble Deep Field-North (HDF-N), probing the X-ray Universe 55-550 times deeper than was possible with pre-Chandra missions. We describe the detected point and extended X-ray sources and discuss their overall multi-wavelength (optical, infrared, submillimetre and radio) properties. Special attention is paid to the HDF-N X-ray sources, luminous infrared starburst galaxies, optically faint X-ray sources and high-to-extreme redshift active galactic nuclei. We also describe how stacking analyses have been used to probe the average X-ray-emission properties of normal and starburst galaxies at cosmologically interesting distances. Finally, we discuss plans to extend the survey and argue that a 5-10 Ms Chandra survey would lay key groundwork for future missions such as XEUS and Generation-X.

VizieR Online Data Catalog: ChaMP. I. First X-ray source catalog (Kim+, 2004)

NASA Astrophysics Data System (ADS)

Kim, D.-W.; Cameron, R. A.; Drake, J. J.; Evans, N. R.; Freeman, P.; Gaetz, T. J.; Ghosh, H.; Green, P. J.; Harnden, F. R. Jr; Karovska, M.; Kashyap, V.; Maksym, P. W.; Ratzlaff, P. W.; Schlegel, E. M.; Silverman, J. D.; Tananbaum, H. D.; Vikhlinin, A. A.; Wilkes, B. J.; Grimes, J. P.

2004-01-01

The Chandra Multiwavelength Project (ChaMP) is a wide-area (~14deg2 < survey of serendipitous Chandra X-ray sources, aiming to establish fair statistical samples covering a wide range of characteristics (such as absorbed active galactic nuclei, high-z clusters of galaxies) at flux levels (fX~10-15 to 10-14erg/s/cm2) ) intermediate between the Chandra deep surveys and previous missions. We present the first ChaMP catalog, which consists of 991 near on-axis, bright X-ray sources obtained from the initial sample of 62 observations. The data have been uniformly reduced and analyzed with techniques specifically developed for the ChaMP and then validated by visual examination. To assess source reliability and positional uncertainty, we perform a series of simulations and also use Chandra data to complement the simulation study. The false source detection rate is found to be as good as or better than expected for a given limiting threshold. On the other hand, the chance of missing a real source is rather complex, depending on the source counts, off-axis distance (or PSF), and background rate. The positional error (95% confidence level) is usually less than 1" for a bright source, regardless of its off-axis distance, while it can be as large as 4" for a weak source (~20counts) at a large off-axis distance (Doff-axis>8'). We have also developed new methods to find spatially extended or temporary variable sources, and those sources are listed in the catalog. (5 data files).

Simulation of a compact analyzer-based imaging system with a regular x-ray source

NASA Astrophysics Data System (ADS)

Caudevilla, Oriol; Zhou, Wei; Stoupin, Stanislav; Verman, Boris; Brankov, J. G.

2017-03-01

Analyzer-based Imaging (ABI) belongs to a broader family of phase-contrast (PC) X-ray techniques. PC measures X-ray deflection phenomena when interacting with a sample, which is known to provide higher contrast images of soft tissue than other X-ray methods. This is of high interest in the medical field, in particular for mammogram applications. This paper presents a simulation tool for table-top ABI systems using a conventional polychromatic X-ray source.

The faint X-ray sources in and out of omega Centauri: X-ray observations and optical identifications

NASA Technical Reports Server (NTRS)

Cool, Adrienne M.; Grindlay, Jonathan E.; Bailyn, Charles D.; Callanan, Paul J.; Hertz, Paul

1995-01-01

We present the results of an observation of the globular cluster omega Cen (NGC 5139) with the Einstein high-resolution imager (HRI). Of the five low-luminosity X-ray sources toward omega Cen which were first identified with the Einstein imaging proportional counter (IPC) (Hertz and Grindlay 1983a, b), two are detected in the Einstein HRI observation: IPC sources A and D. These detections provide source positions accurate to 3 sec-4 sec; the positions are confirmed in a ROSAT HRI observation reported here. Using CCD photometry and spectroscopy, we have identified both sources as foreground dwarf M stars with emission lines (dMe). The chance projection of two Mde stars within approximately 13 min of the center of omega Cen is not extraordinary, given the space density of these stellar coronal X-ray sources. We discuss the possible nature of the three as yet unidentified IPC sources toward omega Cen, and consider the constraints that the Einstein observations place on the total population of X-ray sources in this cluster. The integrated luminosity from faint X-ray sources in omega Cen appears to be low relative to both the old open cluster M67 and the post-core-collapse globular, NGC 6397.

Source Apportionment of Atmospheric Particles by Electron Probe X-Ray Microanalysis and Receptor Models.

NASA Astrophysics Data System (ADS)

van Borm, Werner August

Electron probe X-ray microanalysis (EPXMA) in combination with an automation system and an energy-dispersive X-ray detection system was used to analyse thousands of microscopical particles, originating from the ambient atmosphere. The huge amount of data was processed by a newly developed X-ray correction method and a number of data reduction procedures. A standardless ZAF procedure for EPXMA was developed for quick semi-quantitative analysis of particles starting from simple corrections, valid for bulk samples and modified taking into account the particle finit diameter, assuming a spherical shape. Tested on a limited database of bulk and particulate samples, the compromise between calculation speed and accuracy yielded for elements with Z > 14 accuracies on concentrations less than 10% while absolute deviations remained below 4 weight%, thus being only important for low concentrations. Next, the possibilities for the use of supervised and unsupervised multivariate particle classification were investigated for source apportionment of individual particles. In a detailed study of the unsupervised cluster analysis technique several aspects were considered, that have a severe influence on the final cluster analysis results, i.e. data acquisition, X-ray peak identification, data normalization, scaling, variable selection, similarity measure, cluster strategy, cluster significance and error propagation. A supervised approach was developed using an expert system-like approach in which identification rules are builded to describe the particle classes in a unique manner. Applications are presented for particles sampled (1) near a zinc smelter (Vieille-Montagne, Balen, Belgium), analyzed for heavy metals, (2) in an urban aerosol (Antwerp, Belgium), analyzed for over 20 elements and (3) in a rural aerosol originating from a swiss mountain area (Bern). Thus is was possible to pinpoint a number of known and unknown sources and characterize their emissions in terms of particles abundance and particle composition. Alternatively, the bulk analysis of filters (total, fine and coarse mode) using Particle Induced X -Ray Emission (PIXE) and the application of a receptor modeling approach provided for complementary information on a macroscopical level. A computer program was developed incorporating an absolute factor analysis based receptor modeling procedure. Source profiles and contributions are described by elemental concentrations and an atmospheric mass balance is put forward. The latter method was applied in a two year study of the Antwerp urban aerosol and for the swiss aerosol, revealing a number of previously known and unknown sources. Both methods were successfully combined to increase the source resolution.

National Synchrotron Light Source annual report 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hulbert, S.L.; Lazarz, N.M.

1992-04-01

This report discusses the following research conducted at NSLS: atomic and molecular science; energy dispersive diffraction; lithography, microscopy and tomography; nuclear physics; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; workshop on surface structure; workshop on electronic and chemical phenomena at surfaces; workshop on imaging; UV FEL machine reviews; VUV machine operations; VUV beamline operations; VUV storage ring parameters; x-ray machine operations; x-ray beamline operations; x-ray storage ring parameters; superconducting x-ray lithography source; SXLS storage ring parameters; the accelerator test facility; proposed UV-FEL user facility at the NSLS; global orbit feedback systems; and NSLSmore » computer system.« less

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.

X-ray detectors at the Linac Coherent Light Source.

PubMed

Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; Carron, Sebastian; Dragone, Angelo; Freytag, Dietrich; Haller, Gunther; Hart, Philip; Hasi, Jasmine; Herbst, Ryan; Herrmann, Sven; Kenney, Chris; Markovic, Bojan; Nishimura, Kurtis; Osier, Shawn; Pines, Jack; Reese, Benjamin; Segal, Julie; Tomada, Astrid; Weaver, Matt

2015-05-01

Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a new generation of cameras under development at SLAC, is introduced.

X-ray detectors at the Linac Coherent Light Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella

Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a newmore » generation of cameras under development at SLAC, is introduced.« less

X-ray detectors at the Linac Coherent Light Source

DOE PAGES

Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; ...

2015-04-21

Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a newmore » generation of cameras under development at SLAC, is introduced.« less

X-ray detectors at the Linac Coherent Light Source

PubMed Central

Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; Carron, Sebastian; Dragone, Angelo; Freytag, Dietrich; Haller, Gunther; Hart, Philip; Hasi, Jasmine; Herbst, Ryan; Herrmann, Sven; Kenney, Chris; Markovic, Bojan; Nishimura, Kurtis; Osier, Shawn; Pines, Jack; Reese, Benjamin; Segal, Julie; Tomada, Astrid; Weaver, Matt

2015-01-01

Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a new generation of cameras under development at SLAC, is introduced. PMID:25931071

Astronomers Go Behind The Milky Way To Solve X-Ray Mystery

NASA Astrophysics Data System (ADS)

2001-08-01

Through layers of gas and dust that stretch for more than 30,000 light years, astronomers using NASA's Chandra X-ray Observatory have taken a long, hard look at the plane of the Milky Way galaxy and found that its X-ray glow comes from hot and diffuse gas. The findings, published in the August 10 issue of Science, help to settle a long-standing mystery about the source of the X-ray emission from the galactic plane. Scientists have debated whether the Milky Way plane's X-ray emission was diffuse light or from individual stars. Armed with Chandra, an international team led Dr. Ken Ebisawa of NASA's Goddard Space Flight Center, Greenbelt, MD zoomed in on a tiny region of the galactic plane in the constellation Scutum. "The point sources we saw in the galactic plane were actually active galaxies with bright cores millions of light years behind our galaxy," said Ebisawa. "The number of these sources is consistent with the expected number of extragalactic sources in the background sky. We saw few additional point sources within our Galaxy." The observation marks the deepest X-ray look at the so-called "zone of avoidance" -- a region of space behind which no optical observation has ever been taken because thick dust and gas in the spiral arms of the Milky Way galaxy block out visible radiation. Infrared, radio, and X-rays, however, can penetrate this dust and gas. Detection of diffuse X rays emanating from the Galactic plane, what we call the "Milky Way" in visible light, indicates the presence of plasma gas with temperatures of tens of millions of degrees Celsius. Smoothed X-ray Image of the Galactic Plane Smoothed X-ray Image of the Galactic Plane Gas this hot would escape the gravitational confines of the Milky Way galaxy under normal circumstances. The fact that it still lingers within the Galactic plane is the next mystery to solve. One possibility, suggested by Ebisawa is that hot plasma may be confined to the Milky Way by magnetic fields. The Chandra observation, conducted in February 2000, lasted 28 hours. The team observed what was known to be a "blank" region of the galactic plane where the Japanese X-ray satellite ASCA had previously observed but found no individual X-ray sources. The team also discovered 36 bright distant galaxies lurking in the background of this section of the galactic plane, while the foreground was devoid of stars or other individual objects emitting X-rays. Chandra, and now the European XMM-Newton satellite, are at long last beginning to collect light from behind our galaxy. X-radiation from the 36 newly discovered galaxies passes through the Milky Way on its journey towards Earth. This light, therefore, carries the imprint of all that it passes through and will allow astronomers to measure the distribution and physical condition of matter in our Galaxy. Participating in the Chandra observation and Science article are Yoshitomo Maeda of Pennsylvania State University; Hidehiro Kaneda of the Institute of Space and Astronautical Science in Japan; and Shigeo Yamauchi of Iwate University in Japan. Chandra observed the galactic plane with its Advanced CCD Imaging Spectrometer (ACIS) instrument, which was developed for NASA by Pennsylvania State University, University Park, and Massachusetts Institute of Technology, Cambridge. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program, and TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA.

Development and Characterization of a 16.3 keV X-Ray Source at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Fournier, K. B.; Barrios, M. A.; Schneider, M. B.; Khan, S.; Chen, H.; Coppari, F.; Rygg, R.; Hohenberger, M.; Albert, F.; Moody, J.; Ralph, J.; Kemp, G. E.; Regan, S. P.

2014-10-01

X-ray sources at the National Ignition Facility are needed for radiography of in-flight capsules in inertial confinement fusion experiments and for diffraction studies of materials at high pressures. In the former case, we want to optimize signal to noise and signal over background ratios for the radiograph, in the latter case, we want to minimize high-energy emission from the backlighter that creates background on the diffraction data. Four interleaved shots at NIF were taken in one day, with laser irradiances on a Zr backlighter target ranging from 5 to 14 × 1015 W/cm2. Two shots were for source optimization as a function of laser irradiance. X-ray fluxes were measured with the time-resolved NIF X-ray Spectrometer (NXS) and the DANTE array of calibrated, filtered diodes. Two shots were optimized to make backscatter measurements with the FABS and NBI optical power systems. The backscatter levels are investigated to look for correlation with hot electron populations inferred from high-energy x rays measured with the FFLEX broadband spectrometer. Results from all shots are presented and compared with models. Work performed under the auspices of the U.S. DOE by LLNL under Contract No. DE-AC52-07NA27344.

Micron Scale Mineralogy

NASA Astrophysics Data System (ADS)

Caldwell, W. A.; Tamura, N.; Celestre, R. S.; Padmore, H. A.; Patel, J. R.

2002-12-01

Although x-ray diffraction has been used for nearly a century as the mineralogist's definitive tool in determining crystalline structures, it has proved impossible to use this technique to spatially resolve the highly heterogeneous nature of many minerals at the mesoscopic level. Due to recent revolutions in the brightness of x-ray sources and in our ability to focus x-rays, we can now carry out conventional monochromatic rotation crystallography as well as Laue diffraction with sub-micron spatial resolution and produce maps of orientation, strain, mineral type, and even chemical speciation over tens of microns in a short amount of time. We have pioneered the development of these techniques at the 3rd generation synchrotron radiation source (Advanced Light Source) in Berkeley, and will describe their application to understanding the structure of a quartz-geode. Our results show the manner in which grain structure and texture change as a function of distance from the cavity wall and are compared with models of crystal growth in such systems. This example highlights the great utility of a synchrotron based x-ray micro-diffraction beamline and the possibilities it opens to the mineralogist.

One-shot spectrometer for several elements using an integrated conical crystal analyzer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morishita, Kohei; Nakajima, Kazuo; Hayashi, Kouichi

Time-resolved x-ray spectrometry using an ultrastrong x-ray source such as an x-ray free electron laser is one of the new trends in the field of x-ray physics. To achieve such time-resolved measurement, the development of an one-shot spectrometer with a wide wavelength range, high efficiency, and good energy resolution is an essential prerequisite. Here we developed an integrated conical Ge crystal analyzer consisting of several conical rings, which were connected using spline surfaces to form a single body using our previously developed hot deformation technique, which can form a Si or Ge wafer into an arbitrary and accurate shape. Wemore » simultaneously focused several characteristic lines from an alloy sample onto different positions on a small x-ray charge-coupled device with very high image brightness (gain relative to planar analyzer: 100) and a good spatial resolution of 9-13 eV. The small radius of curvature of the crystal (28-50 mm) enabled us to realize a very short sample-detector distance of 214.4 mm. The present result shows the possibility of realizing a new focusing x-ray crystal spectrograph that can control the focal position as desired.« less

X-Ray Spectrometry of Galactic Sources Seen from the Southern Hemisphere.

DTIC Science & Technology

investigation on glactic X-rays was centered in one experiment carried out in Argentina in November 26, 1969. A balloon-borne equipment was launched in order to detect the X rays from the Centaurus XR-4 source. (Author)

Handbook of X-Ray Astronomy

NASA Technical Reports Server (NTRS)

Arnaud, Keith A. (Editor); Smith, Randall K.; Siemiginowska, Aneta

2011-01-01

X-ray astronomy was born in the aftermath of World War II as military rockets were repurposed to lift radiation detectors above the atmosphere for a few minutes at a time. These early flights detected and studied X-ray emission from the Solar corona. The first sources beyond the Solar System were detected during a rocket flight in 1962 by a team headed by Riccardo Giaccom at American Science and Engineering, a company founded by physicists from MIT. The rocket used Geiger counters with a system designed to reduce non-X-ray backgrounds and collimators limiting the region of sky seen by the counters. As the rocket spun, the field of view (FOV) happened to pass over what was later found to be the brightest non-Solar X-ray source; later designated See X-1. It also detected a uniform background glow which could not be resolved into individual sources. A follow-up campaign using X-ray detectors with better spatial resolution and optical telescopes identified See X-1 as an interacting binary with a compact (neutron star) primary. This success led to further suborbital rocket flights by a number of groups. More X-ray binaries were discovered, as well as X-ray emission from supernova remnants, the radio galaxies M87 and Cygnus-A, and the Coma cluster. Detectors were improved and Geiger counters were replaced by proportional counters, which provided information about energy spectra of the sources. A constant challenge was determining precise positions of sources as only collimators were available.

A Long Decay of X-Ray Flux and Spectral Evolution in the Supersoft Active Galactic Nucleus GSN 069

NASA Astrophysics Data System (ADS)

Shu, X. W.; Wang, S. S.; Dou, L. M.; Jiang, N.; Wang, J. X.; Wang, T. G.

2018-04-01

GSN 069 is an optically identified very low-mass active galactic nuclei (AGN) that shows supersoft X-ray emission. The source is known to exhibit a huge X-ray outburst, with flux increased by more than a factor of ∼240 compared to the quiescence state. We report its long-term evolution in the X-ray flux and spectral variations over a timescale of ∼decade, using both new and archival X-ray observations from the XMM-Newton and Swift. The new Swift observations detected the source in its lowest level of X-ray activity since the outburst, a factor of ∼4 lower in the 0.2–2 keV flux than that obtained with the XMM-Newton observations nearly eight years ago. Combining with the historical X-ray measurements, we find that the X-ray flux is decreasing slowly. There seemed to be spectral softening associated with the drop of X-ray flux. In addition, we find evidence for the presence of a weak, variable, hard X-ray component, in addition to the dominant thermal blackbody emission reported before. The long decay of X-ray flux and spectral evolution, as well as the supersoft X-ray spectra, suggest that the source could be a tidal disruption event (TDE), though a highly variable AGN cannot be fully ruled out. Further continued X-ray monitoring would be required to test the TDE interpretation, by better determining the flux evolution in the decay phase.

Order of Magnitude Sensitivity Increase in X-ray Fluorescence Computed Tomography (XFCT) Imaging With an Optimized Spectro-Spatial Detector Configuration: Theory and Simulation

PubMed Central

Ahmad, Moiz; Bazalova, Magdalena; Xiang, Liangzhong

2014-01-01

The purpose of this study was to increase the sensitivity of XFCT imaging by optimizing the data acquisition geometry for reduced scatter X-rays. The placement of detectors and detector energy window were chosen to minimize scatter X-rays. We performed both theoretical calculations and Monte Carlo simulations of this optimized detector configuration on a mouse-sized phantom containing various gold concentrations. The sensitivity limits were determined for three different X-ray spectra: a monoenergetic source, a Gaussian source, and a conventional X-ray tube source. Scatter X-rays were minimized using a backscatter detector orientation (scatter direction > 110° to the primary X-ray beam). The optimized configuration simultaneously reduced the number of detectors and improved the image signal-to-noise ratio. The sensitivity of the optimized configuration was 10 µg/mL (10 pM) at 2 mGy dose with the mono-energetic source, which is an order of magnitude improvement over the unoptimized configuration (102 pM without the optimization). Similar improvements were seen with the Gaussian spectrum source and conventional X-ray tube source. The optimization improvements were predicted in the theoretical model and also demonstrated in simulations. The sensitivity of XFCT imaging can be enhanced by an order of magnitude with the data acquisition optimization, greatly enhancing the potential of this modality for future use in clinical molecular imaging. PMID:24770916

Order of magnitude sensitivity increase in X-ray Fluorescence Computed Tomography (XFCT) imaging with an optimized spectro-spatial detector configuration: theory and simulation.

PubMed

Ahmad, Moiz; Bazalova, Magdalena; Xiang, Liangzhong; Xing, Lei

2014-05-01

The purpose of this study was to increase the sensitivity of XFCT imaging by optimizing the data acquisition geometry for reduced scatter X-rays. The placement of detectors and detector energy window were chosen to minimize scatter X-rays. We performed both theoretical calculations and Monte Carlo simulations of this optimized detector configuration on a mouse-sized phantom containing various gold concentrations. The sensitivity limits were determined for three different X-ray spectra: a monoenergetic source, a Gaussian source, and a conventional X-ray tube source. Scatter X-rays were minimized using a backscatter detector orientation (scatter direction > 110(°) to the primary X-ray beam). The optimized configuration simultaneously reduced the number of detectors and improved the image signal-to-noise ratio. The sensitivity of the optimized configuration was 10 μg/mL (10 pM) at 2 mGy dose with the mono-energetic source, which is an order of magnitude improvement over the unoptimized configuration (102 pM without the optimization). Similar improvements were seen with the Gaussian spectrum source and conventional X-ray tube source. The optimization improvements were predicted in the theoretical model and also demonstrated in simulations. The sensitivity of XFCT imaging can be enhanced by an order of magnitude with the data acquisition optimization, greatly enhancing the potential of this modality for future use in clinical molecular imaging.

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

NASA Astrophysics Data System (ADS)

Šimon, V.

2017-07-01

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

ROSAT - A German X-ray satellite searches for the big bang

NASA Astrophysics Data System (ADS)

The scientific aims, design, development history, launch, and initial performance of the NASA/FRG orbiting X-ray observatory Rosat are reviewed and illustrated with extensive drawings, diagrams, photographs, and sample images. The main Rosat instrument is a 120-cm-long 83-cm-aperture Wolter X-ray telescope with optical surfaces ground to achieve mean microroughness of less than 1 nm and image resolution 2.5 arcsec. The Rosat mission began with a Delta II launch on June 1, 1990; its first objective is an all-sky X-ray survey which should increase the number of known X-ray sources from about 5000 to over 100,000. The second phase involves detailed observations of selected objects, including nearby normal stars, SN clouds, binary systems, hot neutron stars, and extremely distant QSOs. The first images obtained by Rosat were of the Galactic SNR Cas A, revealing the structure of the shock front and a weak X-ray halo.

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.

ROSAT PSPC and HRI observations of the composite starburst/Seyfert 2 galaxy NGC 1672

NASA Technical Reports Server (NTRS)

Brandt, W. N.; Halpern, Jules P.; Iwasawa, K.

1995-01-01

The nearby barred spiral galaxy NGC 1672 has been observed with the Position Sensitive Proportional Counter (PSPC) and High Resolution Imager (HRI) instruments on board the ROSAT X-ray satellite. NGC 1672 is thought to have an obscured Seyfert nucleus, and it has strong starburst activity as well. Three bright X-ray sources with luminosities 1-2 x 10(exp 40) erg/s are clearly identified with NGC 1672. The strongest lies at the nucleus, and the other two lie at the ends of NGC 1672's prominent bar, locations that are also bright in H alpha and near-infrared images. The nuclear source is resolved by the HRI on about the scale of the recently identified nuclear ring, and one of the sources at the ends of the bar is also probably resolved. The X-ray spectrum of the nuclear source is quite soft, having a Raymond-Smith plasma temperature of approximately equals 0.7 keV and little evidence for intrinsic absorption. The ROSAT band X-ray flux of the nuclear source appears to be dominated not by X-ray binary emission but rather by diffuse gas emission. The absorption and emission properties of the sources, as well as their spatial extents, lead us to models of superbubbles driven by supernovae. However, the large density and emission measure of the nuclear X-ray source stretch the limits that can be comfortably accommodated by these models. We do not detect direct emission from the putative Seyfert nucleus, although an alternative model for the nuclear source is thermal emission from gas that is photoionized by a hidden Seyfert nucleus. The spectra of the other two X-ray sources are harder than that of the nuclear source, and have similar difficulties with regard to superbubble models.

Mapping of electrical potential distribution with charged particle beams. [using an X-ray source

NASA Technical Reports Server (NTRS)

Robinson, J. W.

1979-01-01

Potentials were measured using a beam of soft X-rays in air at 2 x 10 to the -5 power Torr. Ions were detected by a continuous-dynode electron multiplier after they passed through a retarding field. Ultimate resolution depends upon the diameter of the X-ray beam which was 3 mm. When the fields in the region of interest were such to disperse the ions, only a small fraction were detected and the method of measurement was not very reliable. Yet reasonable data could be collected if the ions traveled in parallel paths toward the detector. Development should concentrate on increasing the aperture of the detector from the pinhole which was used to something measured in centimeters. Also increasing the strength of the source would provide a stronger signal and more reliable data. Measurements were made at an estimated ion current to 10 to the -15 power A from a 10 cm length of the X-ray beam, this current being several orders of magnitude below what would have a perturbing effect on the region to be measured. Consequently, the source strength can be increased and prospects for this method of measurement are good.

The Origin of the UCSD X-ray Astronomy Program - A Personal Perspective

NASA Astrophysics Data System (ADS)

Peterson, Laurence E.

2013-01-01

I was a graduate student in the late 1950’s at the University of Minnesota in the Cosmic Ray Group under Prof. John R. Winckler. He had a project monitoring Cosmic ray time variations from an extensive series of balloon flights using simple detectors during the International Geophysical Year 1957-58. During the 20 March 1958 flight, a short 18 sec. burst of high energy radiation was observed simultaneously with a class II Solar flare. From the ratio of the Geiger counter rate to the energy loss in the ionization chamber, it was determined this radiation was likely hard X-rays or low-energy gamma rays and not energetic particles. Further analysis using information from other concurrent observations indicated the X-rays were likely due to Bremsstrahlung from energetic electrons accelerated in the solar flare magnetic field; these same electrons produced radio emissions. This first detection of extra-terrestrial X- or gamma rays showed the importance of non-thermal processes in Astrophysical phenomena. Winckler and I were interested by the possibility of non-solar hard X-rays. While completing my thesis on a Cosmic ray topic, I initiated a balloon program to develop more sensitive collimated low-background scintillation counters. This led to a proposal to the newly formed NASA to place an exploratory instrument on the 1st Orbiting Solar Observatory launched 7 March 1962. In August that year, I assumed a tenure-track position at UCSD; the data analysis of OSO-1 and the balloon program were transferred to UCSD to initiate the X-ray Astronomy program. The discovery of Cosmic X-ray sources in the 1-10 Kev range on a rocket flight in June 1962 by Giacconi and colleagues gave impetus to the UCSD activities. It seemed evident cosmic X-ray sources could be detected above 20 Kev using high-flying balloons. Early results included measurements of the 50 million K gas in SCO X-1, and the X-ray continuum from the Crab Nebula characterized by a power-law dN/dE ~ E-2.2. The instrument developments resulted in ever more sophisticated and sensitive counter systems. Follow-on instruments were flown on OSO-III and OSO-VII by the early 70’s, the HEAO-1 in 1976, and the RXTE in 1995. These provided many new results on Cosmic X-rays.

King's College London/SERC Daresbury Scanning X-ray Microscope

NASA Astrophysics Data System (ADS)

Burge, R. E.; Browne, M. T.; Buckley, C. J.; Cave, R.; Charalambous, P.; Duke, P. J.; Freake, A. J.; Hare, A.; Hills, C. P. B.; Kenney, J. M.; Kuriyama, T.; Lidiard, D.; MacDowell, A.; Michette, A. G.; Morrison, G. R.; Ogawa, K.; Rogoyski, A. M.

1986-01-01

The present status of the soft X-ray microscope is described and a short description is given, with likely development paths for the future, of the Daresbury synchrotron source, the monochromator, the high-resolution zone-plates, the scanning specimen stage, image recording and methods of image enhancement. It is considered that the instrumental developments needed for images at 10 nm resolution will take a further two or three years.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kayser, Y., E-mail: yves.kayser@psi.ch; Paul Scherrer Institut, 5232 Villigen-PSI; Błachucki, W.

2014-04-15

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

Chandra Observations of the X-Ray Environs of SN 1998BW / GRB 980425

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kouveliotou , C.

2004-07-14

We report X-ray studies of the environs of SN 1998bw and GRB 980425 using the Chandra X-Ray Observatory 1281 days after the GRB. Eight X-ray point sources were localized, three and .ve each in the original error boxes--S1 and S2--assigned for variable X-ray counterparts to the GRB by BeppoSAX. The sum of the discrete X-ray sources plus continuous emission in S2 observed by CXO on day 1281 is within a factor of 1.5 of the maximum and the upper limits seen by BeppoSAX. We conclude that S2 is the sum of several variable sources that have not disappeared, and thereforemore » is not associated with the GRB. Within S1, clear evidence is seen for a decline of approximately a factor of 12 between day 200 and day 1281. One of the sources in S1, S1a, is coincident with the well-determined radio location of SN 1998bw, and is certainly the remnant of that explosion. The nature of the other sources is also discussed. Combining our observation of the supernova with others of the GRB afterglow, a smooth X-ray light curve, spanning {approx} 1300 days, is obtained by assuming the burst and supernova were coincident at 35.6 Mpc. When this X-ray light curve is compared with those of the X-ray ''afterglows'' of ordinary GRBs, X-ray Flashes, and ordinary supernovae, evidence emerges for at least two classes of lightcurves, perhaps bounding a continuum. By three to ten years, all these phenomena seem to converge on a common X-ray luminosity, possibly indicative of the supernova underlying them all. This convergence strengthens the conclusion that SN 1998bw and GRB 980425 took place in the same object. One possible explanation for the two classes is a (nearly) standard GRB observed at different angles, in which case X-ray afterglows with intermediate luminosities should eventually be discovered. Finally, we comment on the contribution of GRBs to the ULX source population.« less