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

Science.gov (United States)

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

2013-06-11

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

Subgroup report on hard x-ray microprobes

International Nuclear Information System (INIS)

Ice, G.E.; Barbee, T.; Bionta, R.; Howells, M.; Thompson, A.C.; Yun, W.

1994-01-01

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. Gene 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 rollclose 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

Hard X-ray techniques suitable for polymer experiments

Energy Technology Data Exchange (ETDEWEB)

Bras, W; Goossens, H; Goderis, B, E-mail: Wim.Bras@esrf.fr [Netherlands Organisation for Scientific Research (NWO) (Netherlands); DUBBLE-ESRF, BP 220, F38043 Grenoble Cedex (France); Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Molecular and Nanomaterials, Chemistry Department, Catholic University of Leuven, Celestijnenlaan 200F (Belgium)

2010-11-15

Polymers have been studied since 1979 with 8-12 keV synchrotron radiation X-ray scattering methods and the number and sophistication of the experiments have rapidly grown ever since. More recently, new experimental techniques have been developed that use softer or harder X-rays in less conventional ways. This article provides a brief overview of the possibilities of hard X-ray techniques and indicates some areas that might gain from further developments.

Hard X-ray techniques suitable for polymer experiments

International Nuclear Information System (INIS)

Bras, W; Goossens, H; Goderis, B

2010-01-01

Polymers have been studied since 1979 with 8-12 keV synchrotron radiation X-ray scattering methods and the number and sophistication of the experiments have rapidly grown ever since. More recently, new experimental techniques have been developed that use softer or harder X-rays in less conventional ways. This article provides a brief overview of the possibilities of hard X-ray techniques and indicates some areas that might gain from further developments.

failure analysis and shock protection of external hard disk drive

African Journals Online (AJOL)

user

model its structural responses to free fall drop-impact shock and vibration. Secondly, the hard ... Keywords: Free fall, impact force, Shock, Vibration, Stress, Reliability, Modeling, Simulation External Hard disk drive. 1. ..... on the disk, it could initiate process which could .... [19] Katta, P.: MATLAB Guide to Finite Elements - An.

An Evolutionary Algorithm for Feature Subset Selection in Hard Disk Drive Failure Prediction

Science.gov (United States)

Bhasin, Harpreet

2011-01-01

Hard disk drives are used in everyday life to store critical data. Although they are reliable, failure of a hard disk drive can be catastrophic, especially in applications like medicine, banking, air traffic control systems, missile guidance systems, computer numerical controlled machines, and more. The use of Self-Monitoring, Analysis and…

Hard diffraction and small-x

International Nuclear Information System (INIS)

Anon.

1995-01-01

In the United States, phrases such as ''small-x evolution'', ''the BFKL Pomeron'', ''deep-inelastic rapiditygap events'' and ''hard-diffraction'' do not generate the same intensity of discussion amongst high-energy physicists that they do in Europe. However, for three days in the fall such discussion filled the air at Fermilab. The ''2nd Workshop on Small-x and Diffractive Physics at the Tevatron'' was a review of the rapid theoretical and experimental progress taking place in this field. Although Quantum Chromo-dynamics (QCD) has been established as the theory of strong interactions for twenty years, as yet neither perturbative high-energy calculations nor low-energy non-perturbative techniques have been successfully extended to the mixture of high energy and low transverse momenta which characterize traditional ''soft'' diffractive processes. The simplest soft diffractive process is elastic scattering. In this case it is easiest to accept that there is an exchanged ''pomeron'', which can be pictured as a virtual entity with no electric charge or strong charge (colour), perhaps like an excitation of the vacuum. The same pomeron is expected to appear in all diffractive processes. Understanding the pomeron in QCD is a fundamental theoretical and experimental challenge. In the last two or three years the ''frontier'' in this challenging area of QCD has been pushed back significantly in both theory and experiment. Progress has been achieved by studying the evolution of hard collisions to relatively smaller constituent momenta (small x) and by studying ''hard'' diffractive collisions containing simultaneous signatures of diffraction and hard perturbative processes. The hard processes have included high transverse momentum jet production, deep inelastic lepton scattering, and (most recently) W

Optimization of Smart Structure for Improving Servo Performance of Hard Disk Drive

Science.gov (United States)

Kajiwara, Itsuro; Takahashi, Masafumi; Arisaka, Toshihiro

Head positioning accuracy of the hard disk drive should be improved to meet today's increasing performance demands. Vibration suppression of the arm in the hard disk drive is very important to enhance the servo bandwidth of the head positioning system. In this study, smart structure technology is introduced into the hard disk drive to suppress the vibration of the head actuator. It has been expected that the smart structure technology will contribute to the development of small and light-weight mechatronics devices with the required performance. First, modeling of the system is conducted with finite element method and modal analysis. Next, the actuator location and the control system are simultaneously optimized using genetic algorithm. Vibration control effect with the proposed vibration control mechanisms has been evaluated by some simulations.

77 FR 8284 - Western Digital Technologies, Inc., Hard Drive Development Engineering Group Irvine (Formerly at...

Science.gov (United States)

2012-02-14

... business model of the subject firm is to develop new products domestically and carry out the manufacturing... that the new designs are functional. SAR 8, 20, 26. The subject firm stated that prototype creation is... Technologies, Inc., Hard Drive Development Engineering Group Irvine (Formerly at Lake Forest), CA; Notice of...

Hard X-ray photoemission spectroscopy

International Nuclear Information System (INIS)

Kobayashi, Keisuke

2009-01-01

Except in the very early stage of the development of X-ray photoemission spectroscopy (XPS) by Kai Siegbahn and his coworkers, the excitation sources for XPS studies have predominantly been the Al Kα and Mg Kα emission lines. The advent of synchrotron radiation sources opened up the possibility of tuning the excitation photon energy with much higher throughputs for photoemission spectroscopy, however the excitation energy range was limited to the vacuum ultra violet and soft X-ray regions. Over the past 5-6 years, bulk-sensitive hard X-ray photoemission spectroscopy using high-brilliance high-flux X-rays from third generation synchrotron radiation facilities has been developed. This article reviews the history of HXPES covering the period from Kai Siegbahn and his coworkers' pioneering works to the present, and describes the fundamental aspects, instrumentation, applications to solid state physics, applied physics, materials science, and industrial applications of HXPES. Finally, several challenging new developments which have been conducted at SPring-8 by collaborations among several groups are introduced.

Failure analysis and shock protection of external hard disk drive ...

African Journals Online (AJOL)

Technology for processing and storage of data in portable external storage hard disks has increasingly improved over the years. Currently, terabytes of data can be stored in one portable external storage hard disk drive. Storing such amount of data on a single disk on itself is a risk. Several instances of data lost by big ...

Use of Software Programs as Zero Fill Help in Overcoming the Problem Around Hard Drive

OpenAIRE

Eko Prasetyo Nugroho; Fivtatianti Fivtatianti, Skom, MM

2003-01-01

Zero Fill, is a software tool programs that are designed for hard disk drive specially branded Quantum. This software is a tool programs that function to format the hard drive. Where is the type of format here is the first format or in other words the software to format the hard drive is working under conditions of low- level or commonly referred to as a low- level format. The advantages of this software is able to fix and remove all existing data within the disk, such as files...

Hohlraums energy balance and x-ray drive

International Nuclear Information System (INIS)

Kilkenny, J.D.

1994-01-01

For many years there has been an active ICF program in the US concentrating on x-ray drive. X-ray drive is produced by focusing laser beams into a high Z hohlraum. Conceptually, the radiation field comes close to thermodynamic equilibrium, that is it becomes isotropic and Planckian. These properties lead to the benefits of x-ray drive--it is relatively easy to obtain drive symmetry on a capsule with no small scalelengths drive perturbations. Other advantages of x-ray drive is the higher mass ablation rate, leading to lower growth rates for hydrodynamic instabilities. X-ray drive has disadvantages, principally the loss of energy to the walls of the hohlraum. This report is divided into the following sections: (1) review of blackbody radiation; (2) laser absorption and conversion to x-rays; (3) x-ray absorption coefficient in matter and Rosseland mean free path; (4) Marshak waves in high Z material; (5) x-ray albedo; and (6) power balance and hohlraum temperature

THE 22 MONTH SWIFT-BAT ALL-SKY HARD X-RAY SURVEY

International Nuclear Information System (INIS)

Tueller, J.; Baumgartner, W. H.; Markwardt, C. B.; Skinner, G. K.; Mushotzky, R. F.; Barthelmy, S.; Cummings, J.; Gehrels, N.; Holland, S.; Ajello, M.; Beardmore, A.; Evans, P.; Godet, O.; Brandt, W. N.; Burrows, D.; Grupe, D.; Chincarini, G.; Campana, S.; Cusumano, G.; Fenimore, E.

2010-01-01

We present the catalog of sources detected in the first 22 months of data from the hard X-ray survey (14-195 keV) conducted with the Burst Alert Telescope (BAT) coded mask imager on the Swift satellite. The catalog contains 461 sources detected above the 4.8σ level with BAT. High angular resolution X-ray data for every source from Swift-XRT or archival data have allowed associations to be made with known counterparts in other wavelength bands for over 97% of the detections, including the discovery of ∼30 galaxies previously unknown as active galactic nuclei and several new Galactic sources. A total of 266 of the sources are associated with Seyfert galaxies (median redshift z ∼ 0.03) or blazars, with the majority of the remaining sources associated with X-ray binaries in our Galaxy. This ongoing survey is the first uniform all-sky hard X-ray survey since HEAO-1 in 1977. Since the publication of the nine-month BAT survey we have increased the number of energy channels from four to eight and have substantially increased the number of sources with accurate average spectra. The BAT 22 month catalog is the product of the most sensitive all-sky survey in the hard X-ray band, with a detection sensitivity (4.8σ) of 2.2 x 10 -11 erg cm -2 s -1 (1 mCrab) over most of the sky in the 14-195 keV band.

Effective high voltage at X-ray tube in hard X-ray chest imaging

International Nuclear Information System (INIS)

Klein, J.

1987-01-01

The FRG standard TGL 36 661 (March 1980) for synoptical chest pictures of large size in adults specifies the 120 kV voltage at the X-ray tube together with maximal, 100% use of the capacity of the tube (hard picture, short exposure time). By means of circular recording and by measuring the high voltage at the X-ray tube it was quantitatively shown that the effective voltage during exposure is (according to the exposure time and the attenuation phase of the generator) always lower than the set-up voltage of 120 kV. This phenomenon is the more marked the shorter the actual exposure time in comparison with the attenuation phase of the generator. The typical characteristic of a hard X-ray chest picture is thus not given only by the setting-up of voltage. The impact of the reduction in voltage is thus quantitatively shown also from the aspect of the radiation burden for the patient. (author). 7 figs., 8 refs

Hard X-ray imaging with a slat collimated telescope

International Nuclear Information System (INIS)

Lu Zhuguo; Kotov, Yu.D.; Suslov, A.Yu.

1995-01-01

Imaging experiments with a slat collimated hard X-ray telescope are described in this paper demonstrating the feasibility of the direct demodulation imaging method used in hard X-ray scanning modulation experiments. On 25 September 1993 an X-ray raster scan observation of Cyg X-1 was performed in a balloon flight with the hard X-ray telescope HAPI-4. An experiment to image radioactive X-ray sources was performed in the laboratory before. In both experiments the expected X-ray images were obtained, confirming the imaging capability of this method. (orig.)

Hard X-ray observation of HER X-1

Energy Technology Data Exchange (ETDEWEB)

Ubertini, P.; Bazzano, A.; La Padula, C.; Polcaro, V.F.; Vialetto, G. (Consiglio Nazionale delle Ricerche, Frascati (Italy). Lab. di Astrofisica Spaziale); Manchanda, R.K. (Tata Inst. of Fundamental Research, Bombay (India))

1981-01-01

A hard X-rays (15-170 KeV) measurement of the spectrum of Her X-1, during a mid turn-on is presented. The presence of an emission line at about 53 KeV during the mid-on state is confirmed by the present measure.

Hard X-ray observation of HER X-1

International Nuclear Information System (INIS)

Ubertini, P.; Bazzano, A.; La Padula, C.; Polcaro, V.F.; Vialetto, G.

1981-01-01

A hard X-rays (15-170 KeV) measurement of the spectrum of Her X-1, during a mid turn-on is presented. The presence of an emission line at about 53 KeV during the mid-on state is confirmed by the present measure. (orig.)

Hard x-ray nanoprobe of beamline P06 at PETRA III

Energy Technology Data Exchange (ETDEWEB)

Schroer, C. G., E-mail: christian.schroer@desy.de [Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, D-22607 Hamburg (Germany); Department Physik, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg (Germany); Baumbach, C. [Institute of Optics and Photonics of Condensed Matter, Technische Universität Chemnitz, D-09126 Chemnitz (Germany); Döhrmann, R.; Kahnt, M.; Reinhardt, J.; Scholz, M.; Schropp, A.; Seyrich, M.; Wittwer, F.; Falkenberg, G. [Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, D-22607 Hamburg (Germany); Klare, S.; Hoppe, R.; Patommel, J.; Ritter, S.; Samberg, D.; Seiboth, F. [Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany)

2016-07-27

The hard x-ray scanning microscope at beamline P06 of PETRA III at DESY in Hamburg serves a large user community, from physics, chemistry, and nanotechnology to the bio-medical, materials, environmental, and geosciences. It has been in user operation since 2012, and is mainly based on nanofocusing refractive x-ray lenses. Using refractive optics, nearly gaussian-limited nanobeams in the range from 50 to 100 nm can be generated in the hard x-ray energy range from 8 to 30 keV. The degree of coherence can be traded off against the flux in the nanobeam by a two-stage focusing scheme. We give a brief overview on published results from this instrument and describe its most important components and parameters.

Extragalactic Hard X-ray Surveys: From INTEGRAL to Simbol-X

Science.gov (United States)

Paltani, S.; Dwelly, T.; Walter, R.; McHardy, I. M.; Courvoisier, T. J.-L.

2009-05-01

We present some results of the deepest extragalactic survey performed by the INTEGRAL satellite. The fraction of very absorbed AGN is quite large. The sharp decrease in the absorption fraction with X-ray luminosity observed at lower-energy X-rays is not observed. The current lack of truly Compton-thick objects, with an upper limit of 14% to the size of this population, is just compatible with recent modeling of the cosmic X-ray background. We also study the prospects for a future hard X-ray serendipitous survey with Simbol-X. We show that Simbol-X will easily detect a large number of serendipitous AGN, allowing us to study the evolution of AGN up to redshifts about 2, opening the door to the cosmological study of hard X-ray selected AGN, which is barely possible with existing satellites like Swift and INTEGRAL.

X-ray drive of beryllium capsule implosions at the National Ignition Facility

International Nuclear Information System (INIS)

Wilson, D C; Yi, S A; Simakov, A N; Kline, J L; Kyrala, G A; Olson, R E; Zylstra, A B; Dewald, E L; Tommasini, R; Ralph, J E; Strozzi, D J; Celliers, P M; Schneider, M B; MacPhee, A G; Callahan, D A; Hurricane, O A; Milovich, J L; Hinkel, D E; Rygg, J R; Rinderknecht, H G

2016-01-01

National Ignition Facility experiments with beryllium capsules have followed a path begun with “high-foot” plastic capsule implosions. Three shock timing keyhole targets, one symmetry capsule, a streaked backlit capsule, and a 2D backlit capsule were fielded before the DT layered shot. After backscatter subtraction, laser drive degradation is needed to match observed X-ray drives. VISAR measurements determined drive degradation for the picket, trough, and second pulse. Time dependence of the total Dante flux reflects degradation of the of the third laser pulse. The same drive degradation that matches Dante data for three beryllium shots matches Dante and bangtimes for plastic shots N130501 and N130812. In the picket of both Be and CH hohlraums, calculations over-estimate the x-ray flux > 1.8 keV by ∼100X, while calculating the total flux correctly. In beryllium calculations these X-rays cause an early expansion of the beryllium/fuel interface at ∼3 km/s. VISAR measurements gave only ∼0.3 km/s. The X-ray drive on the Be DT capsule was further degraded by an unplanned decrease of 9% in the total picket flux. This small change caused the fuel adiabat to rise from 1.8 to 2.3. The first NIF beryllium DT implosion achieved 29% of calculated yield, compared to CH capsules with 68% and 21%. (paper)

A HARD X-RAY POWER-LAW SPECTRAL CUTOFF IN CENTAURUS X-4

Energy Technology Data Exchange (ETDEWEB)

Chakrabarty, Deepto; Nowak, Michael A. [MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Tomsick, John A.; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Grefenstette, Brian W.; Fürst, Felix; Harrison, Fiona A.; Rana, Vikram [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Psaltis, Dimitrios [Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Bachetti, Matteo; Barret, Didier [Observatoire Midi-Pyrénées, Université de Toulouse III - Paul Sabatier, F-31400 Toulouse (France); Christensen, Finn E. [Division of Astrophysics, National Space Institute, Technical University of Denmark, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Kaspi, Victoria M. [Department of Physics, McGill University, Montreal, PQ H3A 2T8 (Canada); Miller, Jon M. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Wik, Daniel R.; Zhang, William W. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Wilms, Jörn, E-mail: deepto@mit.edu [Dr. Karl-Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Universität Erlangen-Nürnberg, D-96049 Bamberg (Germany)

2014-12-20

The low-mass X-ray binary (LMXB) Cen X-4 is the brightest and closest (<1.2 kpc) quiescent neutron star transient. Previous 0.5-10 keV X-ray observations of Cen X-4 in quiescence identified two spectral components: soft thermal emission from the neutron star atmosphere and a hard power-law tail of unknown origin. We report here on a simultaneous observation of Cen X-4 with NuSTAR (3-79 keV) and XMM-Newton (0.3-10 keV) in 2013 January, providing the first sensitive hard X-ray spectrum of a quiescent neutron star transient. The 0.3-79 keV luminosity was 1.1×10{sup 33} D{sub kpc}{sup 2} erg s{sup –1}, with ≅60% in the thermal component. We clearly detect a cutoff of the hard spectral tail above 10 keV, the first time such a feature has been detected in this source class. We show that thermal Comptonization and synchrotron shock origins for the hard X-ray emission are ruled out on physical grounds. However, the hard X-ray spectrum is well fit by a thermal bremsstrahlung model with kT{sub e} = 18 keV, which can be understood as arising either in a hot layer above the neutron star atmosphere or in a radiatively inefficient accretion flow. The power-law cutoff energy may be set by the degree of Compton cooling of the bremsstrahlung electrons by thermal seed photons from the neutron star surface. Lower thermal luminosities should lead to higher (possibly undetectable) cutoff energies. We compare Cen X-4's behavior with PSR J1023+0038, IGR J18245–2452, and XSS J12270–4859, which have shown transitions between LMXB and radio pulsar modes at a similar X-ray luminosity.

Characteristics of hard X-ray double sources in impulsive solar flares

Science.gov (United States)

Sakao, T.; Kosugi, T.; Masuda, S.; Yaji, K.; Inda-Koide, M.; Makishima, K.

1996-01-01

Imaging observations of solar flare hard X-ray sources with the Hard X-ray Telescope (HXT) aboard the Yohkoh satellite have revealed that hard X-ray emissions (greater than 30 ke V) originate most frequently from double sources. The double sources are located on both sides of the magnetic neutral line, suggesting that the bulk of hard X-rays is emitted from footpoints of flaring magnetic loops. We also found that hard X-rays from the double sources are emitted simultaneously within a fraction of second and that the weaker source tends to be located in the stronger magnetic field region, showing a softer spectrum. Physcial implications on the observed characteristics of the hard X-ray double sources are discussed.

Polarization and spectral features of the hard x-ray continuum from non-thermal plasmas

International Nuclear Information System (INIS)

Hesse, M.; Platz, P.

1989-12-01

Starting from the cross-sections for the free-free radiation obtained within the relativistic Born-Elwert theory, we calculate the spectral and polarization properties of the hard X-ray continuum (hν > 50 KeV) for plasmas containing fast electrons with an anisotropic velocity distribution. The physical and geometrical quantities of our model are oriented towards the future lower-hybrid current drive (LHCD) experiments on Tore-Supra. Our parameter space covers parallel and perpendicular temperatures, the nuclear charge of the ions (mainly Z = 14 and 28), the cut-off energy of the electrons, the radial current profile and the viewing angle. Extensive calculations open on the optimum conditions for polarization measurements and also give guide-lines for the quantitative interpretation of data under real plasma conditions. A second part of this report will treat with the operational principles and expected performances of hard X-ray polarimeters

The hard x-ray imager onboard IXO

Science.gov (United States)

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.

Neodymium as the main feature of permanent magnets from hard disk drives (HDDs).

Science.gov (United States)

München, Daniel Dotto; Veit, Hugo Marcelo

2017-03-01

As a way to manage neodymium-iron-boron (NdFeB) magnets wasted in end-of-life hard disk drives (HDDs), a waste characterization is needed prior to a recycling process. Due to their magnetic properties, NdFeB magnets are essential in technological applications nowadays, thus causing an increase in the industrial demand for rare earth metals. However, these metals have a short supply, since they are difficult to obtain from ores, creating a critical market. In this work, a study of the characterization of sintered neodymium-iron-boron magnets was undertaken by qualitatively and quantitatively uncovering the neodymium recovery potential from this type of electronic waste. From the collection and disassembly of hard disk drives, in which the magnet represents less than 3% of the total weight, an efficient demagnetization process was proceeded at 320°C. Then, the magnet was ground and screened for an X-ray diffraction (XRD) analysis, which showed the Nd 2 Fe 14 B tetragonal phase as the dominant constituent of the sample. An analysis was also carried out in a scanning electron microscope (SEM) and an inductively coupled plasma optical emission spectrometer (ICP-OES), where the magnet composition showed 21.5wt% of neodymium and 65.1wt% of iron, among other chemicals. This Nd content is higher than the one found in Nd ores, enhancing the recyclability and the importance of waste management. Copyright © 2017 Elsevier Ltd. All rights reserved.

NuSTAR Hard X-ray Survey of the Galactic Center Region. I. Hard X-ray Morphology and Spectroscopy of the Diffuse Emission

DEFF Research Database (Denmark)

Mori, Kaya; Hailey, Charles J.; Krivonos, Roman

2015-01-01

We present the first sub-arcminute images of the Galactic Center above 10 keV, obtained with NuSTAR. NuSTAR resolves the hard X-ray source IGR J17456-2901 into non-thermal X-ray filaments, molecular clouds, point sources, and a previously unknown central component of hard X-ray emission (CHXE). Nu...

Multi-spacecraft observations of solar hard X-ray bursts

International Nuclear Information System (INIS)

Kane, S.R.

1981-01-01

The role of multi-spacecraft observations in solar flare research is examined from the point of view of solar hard X-ray bursts and their implications with respect to models of the impulsive phase. Multi-spacecraft measurements provide a stereoscopic view of the flare region, and hence represent the only direct method of measuring directivity of X-rays. In absence of hard X-ray imaging instruments with high spatial and temporal resolution, multi-spacecraft measurements provide the only means of determining the radial (vertical) structure of the hard X-ray source. This potential of the multi-spacecraft observations is illustrated with an analysis of the presently available observations of solar hard X-ray bursts made simultaneously by two or more of the following spacecraft: International Sun Earth Explorer-3 (ISEE-3), Pioneer Venus Orbiter (PVO), Helios-B and High Energy Astrophysical Observatory-A (HEAO-A). In particular, some conclusions have been drawn about the spatial structure and directivity of 50-100 keV X-rays from impulsive flares. Desirable features of future multi-spacecraft missions are briefly discussed followed by a short description of the hard X-ray experiment on the International Solar Polar Mission which has been planned specifically for multi-spacecraft observations of the Sun. (orig.)

The Ferrara hard X-ray facility for testing/calibrating hard X-ray focusing telescopes

Science.gov (United States)

Loffredo, Gianluca; Frontera, Filippo; Pellicciotta, Damiano; Pisa, Alessandro; Carassiti, Vito; Chiozzi, Stefano; Evangelisti, Federico; Landi, Luca; Melchiorri, Michele; Squerzanti, Stefano

2005-12-01

We will report on the current configuration of the X-ray facility of the University of Ferrara recently used to perform reflectivity tests of mosaic crystals and to calibrate the experiment JEM X aboard Integral. The facility is now located in the technological campus of the University of Ferrara in a new building (named LARIX laboratory= LARge Italian X-ray facility) that includes a tunnel 100 m long with, on the sides, two large experimental rooms. The facility is being improved for determining the optical axis of mosaic crystals in Laue configuration, for calibrating Laue lenses and hard X-ray mirror prototypes.

The over-the-limb hard X-ray events

Science.gov (United States)

Hudson, H. S.

Over-the-limb hard X-ray events offer a uniquely direct view of the hard X-ray emission from the solar corona during a major flare. Limb occultation at angles greater than about 10 deg (an arbitrary definition of this class of events) excludes any confusion with brighter chromospheric sources. Published observations of seven over-the-limb events, beginning with the prototype flare of March 30, 1969, are reviewed. The hard X-ray spectra appear to fall into two classes: hard events, with power-law index of about 2.0; and soft events, with power-law index about 5.4. This tendency towards bimodality is only significant at the 90-percent confidence level due to the smallness of the number of events observed to date. If borne out by future data, the bimodality would suggest the existence of two different acceleration mechanisms.

Anomalous metallic state with strong charge fluctuations in BaxTi8O16 +δ revealed by hard x-ray photoemission spectroscopy

Science.gov (United States)

Dash, S.; Kajita, T.; Okawa, M.; Saitoh, T.; Ikenaga, E.; Saini, N. L.; Katsufuji, T.; Mizokawa, T.

2018-04-01

We have studied a charge-orbital driven metal-insulator transition (MIT) in hollandite-type BaxTi8O16 +δ by means of hard x-ray photoemission spectroscopy (HAXPES). The Ti 2 p HAXPES indicates strong Ti3 +/Ti4 + charge fluctuation in the metallic phase above the MIT temperature. The metallic phase is characterized by a power-law spectral function near the Fermi level which would be a signature of bad metal with non-Drude polaronic behavior. The power-law spectral shape is associated with the large Seebeck coefficient of the metallic phase in BaxTi8O16 +δ .

Sensorless optimal sinusoidal brushless direct current for hard disk drives

Science.gov (United States)

Soh, C. S.; Bi, C.

2009-04-01

Initiated by the availability of digital signal processors and emergence of new applications, market demands for permanent magnet synchronous motors have been surging. As its back-emf is sinusoidal, the drive current should also be sinusoidal for reducing the torque ripple. However, in applications like hard disk drives, brushless direct current (BLDC) drive is adopted instead of sinusoidal drive for simplification. The adoption, however, comes at the expense of increased harmonics, losses, torque pulsations, and acoustics. In this paper, we propose a sensorless optimal sinusoidal BLDC drive. First and foremost, the derivation for an optimal sinusoidal drive is presented, and a power angle control scheme is proposed to achieve an optimal sinusoidal BLDC. The scheme maintains linear relationship between the motor speed and drive voltage. In an attempt to execute the sensorless drive, an innovative power angle measurement scheme is devised, which takes advantage of the freewheeling diodes and measures the power angle through the detection of diode voltage drops. The objectives as laid out will be presented and discussed in this paper, supported by derivations, simulations, and experimental results. The proposed scheme is straightforward, brings about the benefits of sensorless sinusoidal drive, negates the need for current sensors by utilizing the freewheeling diodes, and does not incur additional cost.

NuSTAR Hard X-ray Optics

DEFF Research Database (Denmark)

Koglin, Jason E.; Christensen, Finn Erland; Craig, William W.

2005-01-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) is a small explorer (SMEX) mission currently under an extended Phase A study by NASA. NuSTAR will be the first satellite mission to employ focusing optics in the hard X-ray band (8- 80 keV). Its design eliminates high detector backgrounds, allows...... and production process. We also describe the progress of several components of our independent optics development program that are beginning to reach maturity and could possibly be incorporated into the NuSTAR production scheme. We then present environmental test results that are being conducted in preparation...... of full space qualification of the NuSTAR optics....

Hard X-ray Photoelectric Polarimeter

Data.gov (United States)

National Aeronautics and Space Administration — Our objective is to determine the gas mixtures and pressures that would enable a sensitive, hard X-ray polarimeter using existing flight components with the goal of...

Hard X-ray mirrors for Nuclear Security

Energy Technology Data Exchange (ETDEWEB)

Descalle, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brejnholt, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hill, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Decker, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alameda, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Soufli, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pivovaroff, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pardini, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-01-07

Research performed under this LDRD aimed to demonstrate the ability to detect and measure hard X-ray emissions using multilayer X-ray reflective optics above 400 keV, to enable the development of inexpensive and high-accuracy mirror substrates, and to investigate applications of hard X-ray mirrors of interest to the nuclear security community. Experiments conducted at the European Synchrotron Radiation Facility demonstrated hard X-ray mirror reflectivity up to 650 keV for the first time. Hard X-ray optics substrates must have surface roughness under 3 to 4 Angstrom rms, and three materials were evaluated as potential substrates: polycarbonates, thin Schott glass and a new type of flexible glass called Willow Glass®. Chemical smoothing and thermal heating of the surface of polycarbonate samples, which are inexpensive but have poor intrinsic surface characteristics, did not yield acceptable surface roughness. D263 Schott glass was used for the focusing optics of the NASA NuSTAR telescope. The required specialized hardware and process were costly and motivated experiments with a modified non-contact slumping technique. The surface roughness of the glass was preserved and the process yielded cylindrical shells with good net shape pointing to the potential advantage of this technique. Finally, measured surface roughness of 200 and 130 μm thick Willow Glass sheets was between 2 and 2.5 A rms. Additional results of flexibility tests and multilayer deposition campaigns indicated it is a promising substrate for hard X-ray optics. The detection of U and Pu characteristics X-ray lines and gamma emission lines in a high background environment was identified as an area for which X-ray mirrors could have an impact and where focusing optics could help reduce signal to noise ratio by focusing signal onto a smaller detector. Hence the first one twelvetant of a Wolter I focusing optics for the 90 to 140 keV energy range based on aperiodic multilayer coating was designed. Finally

Hard X-ray spectrum of Her X-1

International Nuclear Information System (INIS)

Ubertini, P.; Bazzano, A.; La Padula, C.D.; Polcaro, V.F.

1981-01-01

The results of a balloon borne hard X-ray observation of Her X-1 is presented. The experiment, released from the base of Hyderabad (India) the 19th April 1980, was a collaboration between the Istituto di Astrofisica Spaziale (Italy) and the TIFR (India). The data obtained are compatible with a thermal emission at low energy with a strong emission line overimposed on the continuum around 50-60 keV

Extended hard-X-ray emission in the inner few parsecs of the Galaxy

DEFF Research Database (Denmark)

Perez, Kerstin; Hailey, Charles J.; Bauer, Franz E.

2015-01-01

of objects emitting soft X-rays (less than 10 kiloelectronvolts) within the surrounding hundreds of parsecs, as well as the population responsible for unresolved X-ray emission extending along the Galactic plane, is dominated by accreting white dwarf systems. Observations of diffuse hard-X-ray (more than 10...... kiloelectronvolts) emission in the inner 10 parsecs, however, have been hampered by the limited spatial resolution of previous instruments. Here we report the presence of a distinct hard-X-ray component within the central 4 × 8 parsecs, as revealed by subarcminute-resolution images in the 20-40 kiloelectronvolt...... outflows interacting with the surrounding radiation field, dense molecular material or magnetic fields. However, all these interpretations pose significant challenges to our understanding of stellar evolution, binary formation, and cosmic-ray production in the Galactic Centre....

Hard X-ray variability of V404 Cygni during the 2015 outburst

Science.gov (United States)

Sánchez-Fernández, C.; Kajava, J. J. E.; Motta, S. E.; Kuulkers, E.

2017-06-01

Aims: Hard X-ray spectra of black hole binaries (BHB) are produced by Comptonization of soft seed photons by hot electrons near the black hole. The slope of the resulting energy spectra is governed by two main parameters: the electron temperature (Te) and optical depth (τ) of the emitting plasma. Given the extreme brightness of V404 Cyg during the 2015 outburst, we aim to constrain the source spectral properties using an unprecedented time resolution in hard X-rays, and to monitor the evolution of Te and τ over the outburst. Methods: We have extracted and analysed 602 X-ray spectra of V404 Cyg obtained by the IBIS/ISGRI instrument on-board INTEGRAL during the 2015 June outburst, using effective integration times ranging between 8 and 176 000 s. We fitted the resulting spectra in the 20-200 keV energy range. Results: We find that while the light curve and soft X-ray spectra of V404 Cyg are remarkably different from those of other BHBs, the spectral evolution of V404 Cyg in hard X-rays and the relations between the spectral parameters are consistent with those observed in other BHBs. We identify a hard branch in which the Te is anti-correlated with the hard X-ray flux, and a soft flaring branch in which the relation reverses. In addition, we find that during long X-ray plateaus detected at intermediate fluxes, the thermal Comptonization models fail to describe the spectra. However, the statistics improve if we allow NH to vary freely in the fits to these spectra. Conclusions: We conclude that the hard branch in V404 Cyg is analogous to the canonical hard state of BHBs. V404 Cyg never seems to enter the canonical soft state, although the soft flaring branch bears resemblance to the BHB intermediate state and ultra-luminous state. The X-ray plateaus are likely the result of absorption by a Compton-thick outflow (NH ≳ 1024 cm-2) which reduces the observed flux by a factor of about 10. Variable covering of the central source by this Compton-thick material may be the

Study of fast electrons from hard-X radiation

International Nuclear Information System (INIS)

Arslanbekov, R.

1995-01-01

The goal of this thesis is the study of fast electron dynamics by means of the hard X-ray diagnosis installed in TORE SUPRA and numerical simulations. Fast electrons are generated in the plasma in the presence of the injected lower hybrid (LH) waves. Two aspects are studied in detail: the lower hybrid wave propagation and absorption in a periodically perturbed media and 2-D Fokker-Planck modelling of the fast electron dynamics in the presence of the LH power. Ripple effects on lower hybrid wave propagation and absorption are investigated using the ray tracing technique. A cylindrical equilibrium is first studied and a strong modification of the ray dynamics is predicted. Calculations are carried out in a real toroidal geometry corresponding to TORE SUPRA. It is shown that the lack of toroidal axisymmetry of the magnetic field may result in a modification of the ray evolution even if the global ray evolution is governed by the larger poloidal inhomogeneity. Simulation of LH experiments are performed for TORE SUPRA tokamak which has a large magnetic ripple (7% at the plasma edge). By considering ripple perturbation in LH current drive simulations, a better agreement is found with experimental results, in particular with the hard-X spectra and the current density profiles. In the second part of the thesis, a 2-D modeling of the fast electron dynamics in the velocity phase space is considered, based on the 2-D relativistic electron Fokker-Planck equation. Electron distribution functions obtained are used to calculate non-thermal Bremsstrahlung emission for different TORE SUPRA shots in a wide range of experimental conditions. (J.S.). 168 refs., 93 figs., 1 tab., 3 appendix

Discovery of Diffuse Hard X-ray Emission associated with Jupiter

Science.gov (United States)

Ezoe, Y.; Miyoshi, Y.; Ishikawa, K.; Ohashi, T.; Terada, N.; Uchiyama, Y.; Negoro, H.

2009-12-01

Our discovery of diffuse hard (1-5 keV) X-ray emission around Jupiter is reported. Recent Chandra and XMM-Newton observations revealed several types of X-rays in the vicinity of Jupiter such as auroral and disk emission from Jupiter and faint diffuse X-rays from the Io Plasma Torus (see Bhardwaj et al. 2007 for review). To investigate possible diffuse hard X-ray emission around Jupiter with the highest sensitivity, we conducted data analysis of Suzaku XIS observations of Jupiter on Feb 2006. After removing satellite and planetary orbital motions, we detected a significant diffuse X-ray emission extending to ~6 x 3 arcmin with the 1-5 keV X-ray luminosity of ~3e15 erg/s. The emitting region very well coincided with the Jupiter's radiation belts. The 1-5 keV X-ray spectrum was represented by a simple power law model with a photon index of 1.4. Such a flat continuum strongly suggests non-thermal origin. Although such an emission can be originated from multiple background point sources, its possibility is quite low. We hence examined three mechanisms, assuming that the emission is truly diffuse: bremsstrahlung by keV electrons, synchrotron emission by TeV electrons, and inverse Compton scattering of solar photons by MeV electrons. The former two can be rejected because of the X-ray spectral shape and implausible existence of TeV electrons around Jupiter, respectively. The last possibility was found to be possible because tens MeV electrons, which have been confirmed in inner radiation belts (Bolton et al. 2002), can kick solar photons to the keV energy range and provide a simple power-law continuum. We estimated an average electron density from the X-ray luminosity assuming the oblate spheroid shaped emitting region with 8 x 8 x 4 Jovian radii. The necessary density was 0.02 1/cm3 for 50 MeV electrons. Hence, our results may suggest a new particle acceleration phenomenon around Jupiter.

Analysis of a biphase-based servo format for hard-disk drives

NARCIS (Netherlands)

Makinwa, K.A.A.; Bergmans, J.W.M.; Voorman, J.O.

2000-01-01

Biphase modulation in an embedded-servo format for hard-disk drives is investigated. It is shown that for biphase, at the low linear densities typical of servo information, near-maximum-likelihood performance can be attained by a simple bit detector consisting of a full-response linear equalizer and

Microfabrication of hard x-ray lenses

DEFF Research Database (Denmark)

Stöhr, Frederik

This thesis deals with the development of silicon compound refractive lenses (Si-CRLs) for shaping hard x-ray beams. The CRLs are to be fabricated using state of the art microfabrication techniques. The primary goal of the thesis work is to produce Si-CRLs with considerably increased structure...... and characterized with respect to their shape. Their optical performances were tested at the European Synchrotron Radiation Facility (ESRF). Two 1D-focusing Si-CRLs suitable as condensers in hard-XRM were developed utilizing the aforementioned two different strategies. The first Si-condenser showed focusing of a 56...... of space for sample surroundings and ensure low-divergent and wide x-ray beams with narrow waists. Both results are substantial improvements to what was available at the start of this thesis work. The challenge of making x-ray objectives in silicon by interdigitation of lenslets alternately focusing...

A hard X-ray nanoprobe beamline for nanoscale microscopy

Energy Technology Data Exchange (ETDEWEB)

Winarski, Robert P., E-mail: winarski@anl.gov; Holt, Martin V. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States); Rose, Volker [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States); Fuesz, Peter; Carbaugh, Dean; Benson, Christa; Shu, Deming; Kline, David; Stephenson, G. Brian; McNulty, Ian [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States); Maser, Jörg [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States)

2012-11-01

The Hard X-ray Nanoprobe Beamline is a precision platform for scanning probe and full-field microscopy with 3–30 keV X-rays. A combination of high-stability X-ray optics and precision motion sensing and control enables detailed studies of the internal features of samples with resolutions approaching 30 nm. The Hard X-ray Nanoprobe Beamline (or Nanoprobe Beamline) is an X-ray microscopy facility incorporating diffraction, fluorescence and full-field imaging capabilities designed and operated by the Center for Nanoscale Materials and the Advanced Photon Source at Sector 26 of the Advanced Photon Source at Argonne National Laboratory. This facility was constructed to probe the nanoscale structure of biological, environmental and material sciences samples. The beamline provides intense focused X-rays to the Hard X-ray Nanoprobe (or Nanoprobe) which incorporates Fresnel zone plate optics and a precision laser sensing and control system. The beamline operates over X-ray energies from 3 to 30 keV, enabling studies of most elements in the periodic table, with a particular emphasis on imaging transition metals.

Black hole and neutron star soft X-ray transients: a hard X-ray view of their outbursts

International Nuclear Information System (INIS)

Yu, W.

2004-01-01

The RXTE public observations of the outbursts of black hole soft X-ray transients XTE J1550-564, XTE J1859+226, 4U 1630-47, XTE J1118+480, XTE J1650-500, and the neutron star soft X-ray transients 4U 1608-52, Aquila X-1, including a variable 'persistent' neutron star low mass X-ray binary 4U 1705-44, are summarized in this paper. The hard X-ray view of those outbursts, which is quite different from that of the soft X-ray band, suggests that there are several types of outbursts which result in different hard X-ray outburst profile - the outburst profiles are energy dependent. One type is the low/hard state outbursts, the other type is the outburst showing transitions from the low/hard state to the high/soft state, or to the intermediate or to the very high state. The later has an initial low/hard state, introducing the phenomena that the hard X-ray precedes the soft X-ray in the outburst rise. Such outbursts in XTE J1550-564, Aql X-1 and 4U 1705-44 support a two-accretion-flow model which involves one Keplerian disk flow and one sub-Keplerian flow for the initial outburst rise

Note: A simple vibrating orifice monodisperse droplet generator using a hard drive actuator arm

Energy Technology Data Exchange (ETDEWEB)

Kosch, Sebastian, E-mail: skosch@mie.utoronto.ca, E-mail: ashgriz@mie.utoronto.ca; Ashgriz, Nasser, E-mail: skosch@mie.utoronto.ca, E-mail: ashgriz@mie.utoronto.ca [Department of Industrial and Mechanical Engineering, University of Toronto, Toronto, Ontario M5S 3G8 (Canada)

2015-04-15

We propose that the rotary voice coil actuators found in magnetic hard drives are fit to supercede loudspeakers as expedient vibration sources in the laboratory setting. A specific use case is the excitation of a liquid jet to induce controlled breakup into monodisperse droplets. Like loudspeakers, which are typically used for prototyping such devices, hard drive actuators are cheap and ubiquitous, but they are less unwieldy and supply greater amplitudes without producing noise. Frequencies between 0 and 17 kHz, and likely beyond, can be reproduced reliably. No machining tools or amplifying electronics are needed for the construction and operation of the presented droplet generator.

Hardness and microstructural characteristics of rapidly solidified Al-8-16 wt.%Si alloys

International Nuclear Information System (INIS)

Uzun, O.; Karaaslan, T.; Gogebakan, M.; Keskin, M.

2004-01-01

Al-Si alloys with nominal composition of Al-8 wt.%Si, Al-12 wt.%Si, and Al-16 wt.%Si were rapidly solidified by using melt-spinning technique to examine the influence of the cooling rate/conditions on microstructure and mechanical properties. The microstructures of the rapidly solidified ribbons and ingot samples were investigated by the optical microscopy, electron microscopy and X-ray diffraction (XRD) techniques. The results showed that the structures of all melt-spun ribbons were completely composed of finely dispersed α-Al and eutectic Si phase, and primary silicon was not observed. The XRD analysis indicated that the solubility of Si in the α-Al matrix was greatly increased with rapid solidification. Additionally, mechanical properties of both conventionally cast (ingot) and melt-spun ribbons were examined by using Vickers indenter for one applied load (0.098 N). The hardness values of the melt-spun ribbons were about three times higher than those of ingot counterparts. The high hardness of the rapidly solidified state can be attributed to the supersaturated solid solutions. Besides, hardness values with different applied loads were measured for melt-spun ribbons. The results indicated that Vickers hardness values (H v ) of the ribbons depended on the applied load. Applying the concept of Hays-Kendall, the load independent hardness values were calculated as 694.0, 982.8 and 1186.8 MN/m 2 for Al-8 wt.%Si, Al-12 wt.%Si and Al-16 wt.%Si, respectively

Weak hard X-ray emission from broad absorption line quasars: evidence for intrinsic X-ray weakness

International Nuclear Information System (INIS)

Luo, B.; Brandt, W. N.; Scott, A. E.; Alexander, D. M.; Gandhi, P.; Stern, D.; Teng, S. H.; Arévalo, P.; Bauer, F. E.; Boggs, S. E.; Craig, W. W.; Christensen, F. E.; Comastri, A.; Farrah, D.; Hailey, C. J.; Harrison, F. A.; Koss, M.; Ogle, P.; Puccetti, S.; Saez, C.

2014-01-01

We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z = 0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z < 1.3. However, their rest-frame ≈2 keV luminosities are 14 to >330 times weaker than expected for typical quasars. Our results from a pilot NuSTAR study of two low-redshift BAL quasars, a Chandra stacking analysis of a sample of high-redshift BAL quasars, and a NuSTAR spectral analysis of the local BAL quasar Mrk 231 have already suggested the existence of intrinsically X-ray weak BAL quasars, i.e., quasars not emitting X-rays at the level expected from their optical/UV emission. The aim of the current program is to extend the search for such extraordinary objects. Three of the six new targets are weakly detected by NuSTAR with ≲ 45 counts in the 3-24 keV band, and the other three are not detected. The hard X-ray (8-24 keV) weakness observed by NuSTAR requires Compton-thick absorption if these objects have nominal underlying X-ray emission. However, a soft stacked effective photon index (Γ eff ≈ 1.8) for this sample disfavors Compton-thick absorption in general. The uniform hard X-ray weakness observed by NuSTAR for this and the pilot samples selected with <10 keV weakness also suggests that the X-ray weakness is intrinsic in at least some of the targets. We conclude that the NuSTAR observations have likely discovered a significant population (≳ 33%) of intrinsically X-ray weak objects among the BAL quasars with significantly weak <10 keV emission. We suggest that intrinsically X-ray weak quasars might be preferentially observed as BAL quasars.

THE 70 MONTH SWIFT-BAT ALL-SKY HARD X-RAY SURVEY

Energy Technology Data Exchange (ETDEWEB)

Baumgartner, W. H.; Tueller, J.; Markwardt, C. B.; Skinner, G. K.; Barthelmy, S.; Gehrels, N. [NASA/Goddard Space Flight Center, Astrophysics Science Division, Greenbelt, MD 20771 (United States); Mushotzky, R. F. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Evans, P. A., E-mail: whbaumga@alum.mit.edu [X-Ray and Observational Astronomy Group/Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom)

2013-08-15

We present the catalog of sources detected in 70 months of observations with the Burst Alert Telescope (BAT) hard X-ray detector on the Swift gamma-ray burst observatory. The Swift-BAT 70 month survey has detected 1171 hard X-ray sources (more than twice as many sources as the previous 22 month survey) in the 14-195 keV band down to a significance level of 4.8{sigma}, associated with 1210 counterparts. The 70 month Swift-BAT survey is the most sensitive and uniform hard X-ray all-sky survey and reaches a flux level of 1.03 Multiplication-Sign 10{sup -11} erg s{sup -1} cm{sup -2} over 50% of the sky and 1.34 Multiplication-Sign 10{sup -11} erg s{sup -1} cm{sup -2} over 90% of the sky. The majority of new sources in the 70 month survey continue to be active galactic nuclei, with over 700 in the catalog. As part of this new edition of the Swift-BAT catalog, we also make available eight-channel spectra and monthly sampled light curves for each object detected in the survey in the online journal and at the Swift-BAT 70 month Web site.

THE 70 MONTH SWIFT-BAT ALL-SKY HARD X-RAY SURVEY

International Nuclear Information System (INIS)

Baumgartner, W. H.; Tueller, J.; Markwardt, C. B.; Skinner, G. K.; Barthelmy, S.; Gehrels, N.; Mushotzky, R. F.; Evans, P. A.

2013-01-01

We present the catalog of sources detected in 70 months of observations with the Burst Alert Telescope (BAT) hard X-ray detector on the Swift gamma-ray burst observatory. The Swift-BAT 70 month survey has detected 1171 hard X-ray sources (more than twice as many sources as the previous 22 month survey) in the 14-195 keV band down to a significance level of 4.8σ, associated with 1210 counterparts. The 70 month Swift-BAT survey is the most sensitive and uniform hard X-ray all-sky survey and reaches a flux level of 1.03 × 10 –11 erg s –1 cm –2 over 50% of the sky and 1.34 × 10 –11 erg s –1 cm –2 over 90% of the sky. The majority of new sources in the 70 month survey continue to be active galactic nuclei, with over 700 in the catalog. As part of this new edition of the Swift-BAT catalog, we also make available eight-channel spectra and monthly sampled light curves for each object detected in the survey in the online journal and at the Swift-BAT 70 month Web site

The Emerging Population of Pulsar Wind Nebulae in Hard X-rays

Science.gov (United States)

Mattana, F.; Götz, D.; Terrier, R.; Renaud, M.; Falanga, M.

2009-05-01

The hard X-ray synchrotron emission from Pulsar Wind Nebulae probes energetic particles, closely related to the pulsar injection power at the present time. INTEGRAL has disclosed the yet poorly known population of hard X-ray pulsar/PWN systems. We summarize the properties of the class, with emphasys on the first hard X-ray bow-shock (CTB 80 powered by PSR B1951+32), and highlight some prospects for the study of Pulsar Wind Nebulae with the Simbol-X mission.

Investigation of the hard x-ray background in backlit pinhole imagers

Energy Technology Data Exchange (ETDEWEB)

Fein, J. R., E-mail: jrfein@umich.edu; Holloway, J. P. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States); Peebles, J. L. [Center for Energy Research, University of California, San Diego, La Jolla, California 92093 (United States); Keiter, P. A.; Klein, S. R.; Kuranz, C. C.; Manuel, M. J.-E.; Drake, R. P. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States)

2014-11-15

Hard x-rays from laser-produced hot electrons (>10 keV) in backlit pinhole imagers can give rise to a background signal that decreases signal dynamic range in radiographs. Consequently, significant uncertainties are introduced to the measured optical depth of imaged plasmas. Past experiments have demonstrated that hard x-rays are produced when hot electrons interact with the high-Z pinhole substrate used to collimate the softer He-α x-ray source. Results are presented from recent experiments performed on the OMEGA-60 laser to further study the production of hard x-rays in the pinhole substrate and how these x-rays contribute to the background signal in radiographs. Radiographic image plates measured hard x-rays from pinhole imagers with Mo, Sn, and Ta pinhole substrates. The variation in background signal between pinhole substrates provides evidence that much of this background comes from x-rays produced in the pinhole substrate itself. A Monte Carlo electron transport code was used to model x-ray production from hot electrons interacting in the pinhole substrate, as well as to model measurements of x-rays from the irradiated side of the targets, recorded by a bremsstrahlung x-ray spectrometer. Inconsistencies in inferred hot electron distributions between the different pinhole substrate materials demonstrate that additional sources of hot electrons beyond those modeled may produce hard x-rays in the pinhole substrate.

Robust design of head interconnect for hard disk drive

Science.gov (United States)

Gao, X. K.; Liu, Q. H.; Liu, Z. J.

2005-05-01

Design of head interconnect is one of the important issues for hard disk drives with higher data rate and storage capacity. The impedance of interconnect and electromagnetic coupling influence the quality level of data communication. Thus an insightful study on how the trace configuration affects the impedance and crosstalk is necessary. An effective design approach based on Taguchi's robust design method is employed therefore in an attempt to realize impedance matching and crosstalk minimization with the effects of uncontrollable sources taken into consideration.

3D visualization of subcellular structures of Schizosaccharomyces pombe by hard X-ray tomography.

Science.gov (United States)

Yang, Y; Li, W; Liu, G; Zhang, X; Chen, J; Wu, W; Guan, Y; Xiong, Y; Tian, Y; Wu, Z

2010-10-01

Cellular structures of the fission yeast, Schizosaccharomyces pombe, were examined by using hard X-ray tomography. Since cells are nearly transparent to hard X-rays, Zernike phase contrast and heavy metal staining were introduced to improve image contrast. Through using such methods, images taken at 8 keV displayed sufficient contrast for observing cellular structures. The cell wall, the intracellular organelles and the entire structural organization of the whole cells were visualized in three-dimensional at a resolution better than 100 nm. Comparison between phase contrast and absorption contrast was also made, indicating the obvious advantage of phase contrast for cellular imaging at this energy. Our results demonstrate that hard X-ray tomography with Zernike phase contrast is suitable for cellular imaging. Its unique abilities make it have potential to become a useful tool for revealing structural information from cells, especially thick eukaryotic cells. © 2010 The Authors Journal compilation © 2010 The Royal Microscopical Society.

Hard x-ray telescope mission

DEFF Research Database (Denmark)

Gorenstein, P.; Worrall, D.; Joensen, K.D.

1996-01-01

The Hard X-Ray Telescope was selected for study as a possible new intermediate size mission for the early 21st century. Its principal attributes are: (1) multiwavelength observing with a system of focussing telescopes that collectively observe from the UV to over 1 MeV, (2) much higher sensitivity...

Runaway electron studies with hard x-ray and microwave diagnostics in the FT-2 lower hybrid current drive discharges

Science.gov (United States)

Shevelev, A. E.; Khilkevitch, E. M.; Lashkul, S. I.; Rozhdestvensky, V. V.; Pandya, S. P.; Plyusnin, V. V.; Altukhov, A. B.; Kouprienko, D. V.; Chugunov, I. N.; Doinikov, D. N.; Esipov, L. A.; Gin, D. B.; Iliasova, M. V.; Naidenov, V. O.; Polunovsky, I. A.; Sidorov, A. V.; Kiptily, V. G.

2018-01-01

Studies of the super-thermal and runaway electron behavior in ohmic and lower hybrid current drive FT-2 tokamak plasmas have been carried out using information obtained from measurements of hard x-ray spectra and non-thermal microwave radiation intensity at the frequency of 10 GHz and in the range of (53 ÷ 78) GHz. A gamma-ray spectrometer based on a scintillation detector with a LaBr3(Ce) crystal was used, which provides measurements at counting rates up to 107 s-1. Reconstruction of the energy distribution of RE interacting with the poloidal limiter of the tokamak chamber was made with application of the DeGaSum code. Super-thermal electrons accelerated up to 2 MeV by the LH waves at the high-frequency pumping of the plasma with low density ≤ft ~ 2  ×  1013 cm-3 and then up to 7 MeV by vortex electric field have been found. Experimental analysis of the runaway electron beam generation and evolution of their energy distribution in the FT-2 plasmas is presented in the article and compared with the numerical calculation of the maximum energy gained by runaway electrons for given plasma parameters. In addition, possible mechanisms for limiting the maximum energy gained by the runaway electrons are also calculated and described for a FT-2 plasma discharge.

X-ray system with coupled source drive and detector drive

International Nuclear Information System (INIS)

1976-01-01

An electronic coupling replacing the (more expensive) mechanical coupling which controls the speed of two sets of two electric motors, one driving an X-ray source and the other an X-ray detector, is described. Source and detector are kept rotating in parallel planes with a fairly constant velocity ratio. The drives are controlled by an electronic system comprising a comparator circuit comparing the position-indicative signals, a process control circuit and an inverter switch. The control system regulates the speed of the electric motors. The signal processing is described

Prospects for supermirrors in hard x-ray spectroscopy

DEFF Research Database (Denmark)

Joensen, Karsten D.; Gorenstein, Paul; Christensen, Finn Erland

1994-01-01

. The measured x-ray reflectivities are well accounted for by the standard dynamical theories of multilayer reflection. Hard x ray applications that could benefit from x-ray supermirror coatings include focusing and imaging instrumentation for astrophysics, collimating and focusing devices for synchrotron...

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

Science.gov (United States)

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.

NuSTAR hard X-ray observations of the Jovian magnetosphere during Juno perijove and apojove intervals

Science.gov (United States)

Dunn, W.; Mori, K.; Hailey, C. J.; Branduardi-Raymont, G.; Grefenstette, B.; Jackman, C. M.; Hord, B. J.; Ray, L. C.

2017-12-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) is the first focusing hard X-ray telescope operating in the 3-79 keV band with sub-arcminute angular resolution (18" FWHM). For the first time, NuSTAR provides sufficient sensitivity to detect/resolve hard X-ray emission from Jupiter above 10 keV, since the in-situ Ulysses observation failed to detect X-ray emission in the 27-48 keV band [Hurley et al. 1993]. The initial, exploratory NuSTAR observation of Jupiter was performed in February 2015 with 100 ksec exposure. NuSTAR detected hard X-ray emission (E > 10 keV) from the south polar region at a marginally significance of 3 sigma level [Mori et al. 2016, AAS meeting poster]. This hard X-ray emission is likely an extension of the non-thermal bremsstrahlung component detected up to 7 keV by XMM-Newton [Branduardi-Raymont et al. 2007]. The Ulysses non-detection suggests there should be a spectral cutoff between 7 and 27 keV. Most intriguingly, the NuSTAR detection of hard X-ray emission from the south aurora is in contrast to the 2003 XMM-Newton observations where soft X-ray emission below 8 keV was seen from both the north and south poles [Gladstone et al. 2002]. Given the marginal, but tantalizing, hard X-ray detection of the southern Jovian aurora, a series of NuSTAR observations with total exposure of nearly half a million seconds were approved in the NuSTAR GO and DDT program. These NuSTAR observations coincided with one Juno apojove (in June 2017) and three perijoves (in May, July and September 2017), also joining the multi-wavelength campaigns of observing Jupiter coordinating with Chandra and XMM-Newton X-ray telescope (below 10 keV) and HST. We will present NuSTAR imaging, spectral and timing analysis of Jupiter. NuSTAR imaging analysis will map hard X-ray emission in comparison with soft X-ray and UV images. In addition to investigating any distinctions between the soft and hard X-ray morphology of the Jovian aurorae, we will probe whether hard X

NuSTAR HARD X-RAY SURVEY OF THE GALACTIC CENTER REGION. I. HARD X-RAY MORPHOLOGY AND SPECTROSCOPY OF THE DIFFUSE EMISSION

Energy Technology Data Exchange (ETDEWEB)

Mori, Kaya; Hailey, Charles J.; Perez, Kerstin; Nynka, Melania; Zhang, Shuo; Canipe, Alicia M. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Krivonos, Roman; Tomsick, John A.; Barrière, Nicolas; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Hong, Jaesub [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Ponti, Gabriele [Max-Planck-Institut f. extraterrestrische Physik, HEG, Garching (Germany); Bauer, Franz [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, 306, Santiago 22 (Chile); Alexander, David M. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Baganoff, Frederick K. [Kavli Institute for Astrophysics and Space Research, Massachusets Institute of Technology, Cambridge, MA 02139 (United States); Barret, Didier [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Christensen, Finn E. [DTU Space—National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Forster, Karl [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Giommi, Paolo, E-mail: kaya@astro.columbia.edu [ASI Science Data Center, Via del Politecnico snc I-00133, Roma (Italy); and others

2015-12-01

We present the first sub-arcminute images of the Galactic Center above 10 keV, obtained with NuSTAR. NuSTAR resolves the hard X-ray source IGR J17456–2901 into non-thermal X-ray filaments, molecular clouds, point sources, and a previously unknown central component of hard X-ray emission (CHXE). NuSTAR detects four non-thermal X-ray filaments, extending the detection of their power-law spectra with Γ ∼ 1.3–2.3 up to ∼50 keV. A morphological and spectral study of the filaments suggests that their origin may be heterogeneous, where previous studies suggested a common origin in young pulsar wind nebulae (PWNe). NuSTAR detects non-thermal X-ray continuum emission spatially correlated with the 6.4 keV Fe Kα fluorescence line emission associated with two Sgr A molecular clouds: MC1 and the Bridge. Broadband X-ray spectral analysis with a Monte-Carlo based X-ray reflection model self-consistently determined their intrinsic column density (∼10{sup 23} cm{sup −2}), primary X-ray spectra (power-laws with Γ ∼ 2) and set a lower limit of the X-ray luminosity of Sgr A* flare illuminating the Sgr A clouds to L{sub X} ≳ 10{sup 38} erg s{sup −1}. Above ∼20 keV, hard X-ray emission in the central 10 pc region around Sgr A* consists of the candidate PWN G359.95–0.04 and the CHXE, possibly resulting from an unresolved population of massive CVs with white dwarf masses M{sub WD} ∼ 0.9 M{sub ⊙}. Spectral energy distribution analysis suggests that G359.95–0.04 is likely the hard X-ray counterpart of the ultra-high gamma-ray source HESS J1745–290, strongly favoring a leptonic origin of the GC TeV emission.

Model independent method to deconvolve hard X-ray spectra

Energy Technology Data Exchange (ETDEWEB)

Polcaro, V.F.; Bazzano, A.; Ubertini, P.; La Padula, C. (Consiglio Nazionale delle Ricerche, Frascati (Italy). Lab. di Astrofisica Spaziale); Manchanda, R.K. (Tata Inst. of Fundamental Research, Bombay (India))

1984-07-01

A general purpose method to deconvolve the energy spectra detected by means of the use of a hard X-ray telescope is described. The procedure does not assume any form of input spectrum and the observed energy loss spectrum is directly deconvolved into the incident photon spectrum, the form of which can be determined independently of physical interpretation of the data. Deconvolution of the hard X-ray spectrum of Her X-1, detected during the HXR 81M experiment, by the method independent method is presented.

A production throughput forecasting system in an automated hard disk drive test operation using GRNN

Energy Technology Data Exchange (ETDEWEB)

Samattapapong, N.; Afzulpurkar, N.

2016-07-01

The goal of this paper is to develop a pragmatic system of a production throughput forecasting system for an automated test operation in a hard drive manufacturing plant. The accurate forecasting result is necessary for the management team to response to any changes in the production processes and the resources allocations. In this study, we design a production throughput forecasting system in an automated test operation in hard drive manufacturing plant. In the proposed system, consists of three main stages. In the first stage, a mutual information method was adopted for selecting the relevant inputs into the forecasting model. In the second stage, a generalized regression neural network (GRNN) was implemented in the forecasting model development phase. Finally, forecasting accuracy was improved by searching the optimal smoothing parameter which selected from comparisons result among three optimization algorithms: particle swarm optimization (PSO), unrestricted search optimization (USO) and interval halving optimization (IHO). The experimental result shows that (1) the developed production throughput forecasting system using GRNN is able to provide forecasted results close to actual values, and to projected the future trends of production throughput in an automated hard disk drive test operation; (2) An IHO algorithm performed as superiority appropriate optimization method than the other two algorithms. (3) Compared with current forecasting system in manufacturing, the results show that the proposed system’s performance is superior to the current system in prediction accuracy and suitable for real-world application. The production throughput volume is a key performance index of hard disk drive manufacturing systems that need to be forecast. Because of the production throughput forecasting result is useful information for management team to respond to any changing in production processes and resources allocation. However, a practically forecasting system for

Mechanical design of multiple zone plates precision alignment apparatus for hard X-ray focusing in twenty-nanometer scale

Energy Technology Data Exchange (ETDEWEB)

Shu, Deming; Liu, Jie; Gleber, Sophie C.; Vila-Comamala, Joan; Lai, Barry; Maser, Jorg M.; Roehrig, Christian; Wojcik, Michael J.; Vogt, Franz Stefan

2017-04-04

An enhanced mechanical design of multiple zone plates precision alignment apparatus for hard x-ray focusing in a twenty-nanometer scale is provided. The precision alignment apparatus includes a zone plate alignment base frame; a plurality of zone plates; and a plurality of zone plate holders, each said zone plate holder for mounting and aligning a respective zone plate for hard x-ray focusing. At least one respective positioning stage drives and positions each respective zone plate holder. Each respective positioning stage is mounted on the zone plate alignment base frame. A respective linkage component connects each respective positioning stage and the respective zone plate holder. The zone plate alignment base frame, each zone plate holder and each linkage component is formed of a selected material for providing thermal expansion stability and positioning stability for the precision alignment apparatus.

HARD X-RAY TAIL DISCOVERED IN THE CLOCKED BURSTER GS 1826–238

Energy Technology Data Exchange (ETDEWEB)

Rodi, J.; Jourdain, E.; Roques, J. P., E-mail: jrodi@irap.omp.eu [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France)

2016-02-01

The low-mass X-ray binary (LMXB) neutron star (NS) GS 1826–238 was discovered by Ginga in 1988 September. Due to the presence of quasi-periodicity in the type I X-ray burst rate, the source has been a frequent target of X-ray observations for almost 30 years. Though the bursts were too soft to be detected by INTEGRAL/SPI, the persistent emission from GS 1826–238 was detected over 150 keV during the ∼10 years of observations. Spectral analysis found a significant high-energy excess above a Comptonization model that is well fit by a power law, indicating an additional spectral component. Most previously reported spectra with hard tails in LMXB NS have had an electron temperature of a few keV and a hard tail dominating above ∼50 keV with an index of Γ ∼ 2–3. GS 1826–238 was found to have a markedly different spectrum with kT{sub e} ∼ 20 keV and a hard tail dominating above ∼150 keV with an index of Γ ∼ 1.8, more similar to black hole X-ray binaries. We report on our search for long-term spectral variability over the 25–370 keV energy range and on a comparison of the GS 1826–238 average spectrum to the spectra of other LMXB NSs with hard tails.

Hard X-ray Emission and Efficient Particle Acceleration by Supernova Remnants

International Nuclear Information System (INIS)

Vink, Jacco

2009-01-01

I discuss the non-thermal X-ray emission from young supernova remnants. Over the last decade it has become clear from both X-ray and γ-ray observations that young supernovae accelerate particles up to 100 TeV. In soft X-rays the accelerated >10 TeV electrons produce synchrotron radiation, coming from narrow filaments located at the shock fronts. The width of these filaments shows that the magnetic fields are relatively high, thus providing evidence for magnetic field amplification.The synchrotron radiation of several remnants is known to extend into the hard X-ray regime. In particular Cas A, has a spectrum that appears as a power law up to almost 100 TeV. This is very surprising, as a steepening is expected going from the soft to the hard X-ray band. The spectrum is likely a result of many superimposed individual spectra, each steepening at different energies. This implies considerable spatial variation in hard X-rays, an obvious target for Simbol-X. The variations will be important to infer local shock acceleration properties, but also magnetic field fluctuations may cause spatial and temporal variations.Finally, I draw the attention to super bubbles and supernovae as sources of cosmic rays. As such they may be sources of hard X-ray emission. In particular, supernovae exploding inside the dense red supergiants winds of their progenitors ares promising candidates for hard X-ray emission.

Hard X-ray Emission and Efficient Particle Acceleration by Supernova Remnants

Science.gov (United States)

Vink, Jacco

2009-05-01

I discuss the non-thermal X-ray emission from young supernova remnants. Over the last decade it has become clear from both X-ray and γ-ray observations that young supernovae accelerate particles up to 100 TeV. In soft X-rays the accelerated >10 TeV electrons produce synchrotron radiation, coming from narrow filaments located at the shock fronts. The width of these filaments shows that the magnetic fields are relatively high, thus providing evidence for magnetic field amplification. The synchrotron radiation of several remnants is known to extend into the hard X-ray regime. In particular Cas A, has a spectrum that appears as a power law up to almost 100 TeV. This is very surprising, as a steepening is expected going from the soft to the hard X-ray band. The spectrum is likely a result of many superimposed individual spectra, each steepening at different energies. This implies considerable spatial variation in hard X-rays, an obvious target for Simbol-X. The variations will be important to infer local shock acceleration properties, but also magnetic field fluctuations may cause spatial and temporal variations. Finally, I draw the attention to super bubbles and supernovae as sources of cosmic rays. As such they may be sources of hard X-ray emission. In particular, supernovae exploding inside the dense red supergiants winds of their progenitors ares promising candidates for hard X-ray emission.

Comptonization of low-frequency radiation in accretion disks Angular distribution and polarization of hard X-ray radiation

International Nuclear Information System (INIS)

Suniaev, R.A.; Titarchuk, L.G.

1984-01-01

Analytical consideration is given to the comptonization of photons and its effects on the radiation emitted from accretion disks of compact X-ray sources, such as black holes and neutron stars. Attention is given to the photon distribution during escape from the disk, the angular distribution of hard radiation from the disk, the polarization of hard radiation and the electron temperature distribution over the optical depth. It is shown that the hard radiation spectrum is independent of the low-frequency photon source distribution. The angular distribution and polarization of the outgoing X-rays are a function of the optical depth. A Thomson approximation is used to estimate the angular distribution of the hard radiation and the polarization over the disk. The polarization results are compared with OSO-8 satellite data for Cyg X-1 and show good agreement at several energy levels. 17 references

The Relationship Between Solar Radio and Hard X-Ray Emission

Science.gov (United States)

White, S. M.; Benz, A. O.; Christe, S.; Farnik, F.; Kundu, M. R.; Mann, G.; Ning, Z.; Raulin, J.-P.; Silva-Valio, A. V. R.; Saint-Hilaire, P.;

Quantitative 3D imaging of yeast by hard X-ray tomography.

Science.gov (United States)

Zheng, Ting; Li, Wenjie; Guan, Yong; Song, Xiangxia; Xiong, Ying; Liu, Gang; Tian, Yangchao

2012-05-01

Full-field hard X-ray tomography could be used to obtain three-dimensional (3D) nanoscale structures of biological samples. The image of the fission yeast, Schizosaccharomyces pombe, was clearly visualized based on Zernike phase contrast imaging technique and heavy metal staining method at a spatial resolution better than 50 nm at the energy of 8 keV. The distributions and shapes of the organelles during the cell cycle were clearly visualized and two types of organelle were distinguished. The results for cells during various phases were compared and the ratios of organelle volume to cell volume can be analyzed quantitatively. It showed that the ratios remained constant between growth and division phase and increased strongly in stationary phase, following the shape and size of two types of organelles changes. Our results demonstrated that hard X-ray microscopy was a complementary method for imaging and revealing structural information for biological samples. Copyright © 2011 Wiley Periodicals, Inc.

X-ray geometrical smoothing effect in indirect x-ray-drive implosion

International Nuclear Information System (INIS)

Mochizuki, Takayasu; Sakabe, Shuji; Yamanaka, Chiyoe

1983-01-01

X-ray geometrical smoothing effect in indirect X-ray drive pellet implosion for inertial confinement fusion has been numerically analyzed. Attainable X-ray driven ablation pressure has been found to be coupled with X-ray irradiation uniformity. (author)

A hard X-ray laboratory for monochromator characterisation

Energy Technology Data Exchange (ETDEWEB)

Hamelin, B [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

1997-04-01

Since their installation at ILL during the 1970`s the ILL {gamma}-ray diffractometers have been intensively used in the development of neutron monochromators. However, the ageing of the sources and new developments in hard X-ray diffractometry lead to a decision at the end of 1995 to replace the existing {gamma}-ray laboratory with a hard X-ray laboratory, based on a 420 keV generator, making available in the long term several beam-lines for rapid characterisation of monochromator crystals. The facility is now installed and its characteristics and advantages are outlined. (author). 2 refs.

Characterizations of MCP performance in the hard x-ray range (6–25 keV)

Energy Technology Data Exchange (ETDEWEB)

Wu, Ming, E-mail: minwu@sandia.gov; Rochau, Greg [Sandia National Laboratory, Albuquerque, New Mexico 87185 (United States); Moy, Ken [Special Technology Laboratories, NSTec, Santa Barbara, California 93111-2335 (United States); Kruschwitz, Craig [National Security Technologies, LLC, Los Alamos Operations, Los Alamos, New Mexico 87544 (United States)

2014-11-15

MCP detector performance at hard x-ray energies from 6 to 25 keV was recently investigated using NSLS beamline X15A at BNL. Measurements were made with an NSTec Gen-II (H-CA-65) framing camera, based on a Photonis MCP with ∼10 μm in diameter pores, ∼12 μm center-center spacing, an L/D ratio of 46, and a bias angle of 8°. The MCP characterizations were focused on (1) energy and angle dependent sensitivity, (2) energy and angle dependent spatial resolution, (3) energy dependent gain performance, and (4) energy dependent dynamic range. These measurement corroborated simulation results using a Monte Carlo model that included hard x-ray interactions and the subsequent electron cascade in the MCP.

Polarization of hard X-rays, a contribution to the measurement of the non-thermal electron distribution function (L.H.C.D.)

International Nuclear Information System (INIS)

Hesse, M.; Platz, P.

1990-01-01

The hard X-ray spectrum emitted by a plasma containing non-thermal electrons generated during Lower Hybrid Current Drive experiments has already been measured on several tokamaks, but the properties of the bremsstrahlung have not yet been studied. The present study starts with the comparison of tractable analytical expressions of cross-sections with more precise computer-calculated values; then an evaluation of the polarization is carried out under real tokamak current drive situations and finally a proposal of a new diagnostic for the Tore Supra LHCD experiment is presented. (author) 6 refs., 6 figs

High resolution hard X-ray photoemission using synchrotron radiation as an essential tool for characterization of thin solid films

International Nuclear Information System (INIS)

Kim, J.J.; Ikenaga, E.; Kobata, M.; Takeuchi, A.; Awaji, M.; Makino, H.; Chen, P.P.; Yamamoto, A.; Matsuoka, T.; Miwa, D.; Nishino, Y.; Yamamoto, T.; Yao, T.; Kobayashi, K.

2006-01-01

Recently, we have shown that hard X-ray photoemission spectroscopy using undulator X-rays at SPring-8 is quite feasible with both high resolution and high throughput. Here we report an application of hard X-ray photoemission spectroscopy to the characterization of electronic and chemical states of thin solid films, for which conventional PES is not applicable. As a typical example, we focus on the problem of the scatter in the reported band-gap values for InN. We show that oxygen incorporation into the InN film strongly modifies the valence and plays a crucial role in the band gap problem. The present results demonstrate the powerful applicability of high resolution photoemission spectroscopy with hard X-rays from a synchrotron source

Sub-100 nm hard X-ray microbeam generation with Fresnel zone plate optics

CERN Document Server

Takano, H; Takeuchi, A

2003-01-01

A hard X-ray focusing test of a Fresnel zone plate has been performed with a synchrotron radiation source at the undulator beamline 20XU of SPring-8. Fresnel zone plate with a radius of 150 mu m, and an outermost zone width of 100 nm was used for the X-ray focusing device. The 248-m-long beamline provides fully coherent illumination for the focusing device. The focused beam evaluated by the knife-edge-scan method and scanning microscope test using test charts. Nearly diffraction- limited focusing with a size of 120 nm was achieved for the first-order diffraction at 10 keV X-ray. Evaluation for the third order diffraction was also performed at 8 keV X-ray, and a focal size of 50 m has been obtained. (author)

On the Dynamics of Rocking Motion of the Hard-Disk Drive Spindle Motor System

Science.gov (United States)

Wang, Joseph

Excessive rocking motion of the spindle motor system can cause track misregistration resulting in poor throughput or even drive failure. The chance of excessive disk stack rocking increases as a result of decreasing torsional stiffness of spindle motor bearing system due to the market demand for low profile hard drives. As the track density increases and the vibration specification becomes increasingly stringent, rocking motion of a spindle motor system deserves even more attention and has become a primary challenge for a spindle motor system designer. Lack of understanding of the rocking phenomenon combined with misleading paradox has presented a great difficulty in the effort of avoiding the rocking motion in the hard-disk drive industry. This paper aims to provide fundamental understanding of the rocking phenomenon of a rotating spindle motor system, to clarify the paradox in disk-drive industry and to provide a design guide to an optimized spindle system. This paper, theoretically and experimentally, covers a few important areas of industrial interest including the prediction of rocking natural frequencies and mode shape of a rotating spindle, free vibration, and frequency response under common forcing functions such as rotating and fixed-plane forcing functions. The theory presented here meets with agreeable experimental observation.

Great microwave bursts and hard X-rays from solar flares

International Nuclear Information System (INIS)

Wiehl, H.J.; Batchelor, D.A.; Crannell, C.J.; Dennis, B.R.; Price, P.N.

1983-06-01

The microwave and hard X-ray charateristics of 13 solar flares that produced microwave fluxes greater than 500 Solar Flux Units were analyzed. These Great Microwave Bursts were observed in the frequency range from 3 to 35 GHz at Berne, and simultaneous hard X-ray observations were made in the energy range from 30 to 500 keV with the Hard X-Ray Burst Spectrometer on the Solar Maximum Mission spacecraft. The principal aim of this analysis is to determine whether or not the same distribution of energetic electrons can explain both emissions. Correlations were found between respective temporal characteristics and, for the first time, between microwave and hard X-ray spectral characteristics. A single-temperature and a multi-temperature model from the literature were tested for consistency with the coincident X-ray and microwave spectra at microwave burst maximum. Four events are inconsistent with both of the models tested, and neither of the models attempts to explain the high-frequency part of the microwave spectrum. A model in which the emissions above and below the peak frequency originate in two different parts of a diverging magnetic loop is proposed. With this model the entire microwave spectrum of all but one of the events is explained

LAMBDA 2M GaAs—A multi-megapixel hard X-ray detector for synchrotrons

Science.gov (United States)

Pennicard, D.; Smoljanin, S.; Pithan, F.; Sarajlic, M.; Rothkirch, A.; Yu, Y.; Liermann, H. P.; Morgenroth, W.; Winkler, B.; Jenei, Z.; Stawitz, H.; Becker, J.; Graafsma, H.

2018-01-01

Synchrotrons can provide very intense and focused X-ray beams, which can be used to study the structure of matter down to the atomic scale. In many experiments, the quality of the results depends strongly on detector performance; in particular, experiments studying dynamics of samples require fast, sensitive X-ray detectors. "LAMBDA" is a photon-counting hybrid pixel detector system for experiments at synchrotrons, based on the Medipix3 readout chip. Its main features are a combination of comparatively small pixel size (55 μm), high readout speed at up to 2000 frames per second with no time gap between images, a large tileable module design, and compatibility with high-Z sensors for efficient detection of higher X-ray energies. A large LAMBDA system for hard X-ray detection has been built using Cr-compensated GaAs as a sensor material. The system is composed of 6 GaAs tiles, each of 768 by 512 pixels, giving a system with approximately 2 megapixels and an area of 8.5 by 8.5 cm2. While the sensor uniformity of GaAs is not as high as that of silicon, its behaviour is stable over time, and it is possible to correct nonuniformities effectively by postprocessing of images. By using multiple 10 Gigabit Ethernet data links, the system can be read out at the full speed of 2000 frames per second. The system has been used in hard X-ray diffraction experiments studying the structure of samples under extreme pressure in diamond anvil cells. These experiments can provide insight into geological processes. Thanks to the combination of high speed readout, large area and high sensitivity to hard X-rays, it is possible to obtain previously unattainable information in these experiments about atomic-scale structure on a millisecond timescale during rapid changes of pressure or temperature.

Backscatter, anisotropy, and polarization of solar hard X-rays

International Nuclear Information System (INIS)

Bai, T.; Ramaty, R.

1978-01-01

Hard X-rays incident upon the photosphere with energies > or approx. =15 keV have high probabilities of backscatter due to Compton collisions with electrons. This effect has a strong influence on the spectrum, intensity, and polarization of solar hard X-rays - especially for anisotropic models in which the primary X-rays are emitted predominantly toward the photosphere. We have carried out a detailed study of X-ray backscatter, and we have investigated the interrelated problems of anisotropy, polarization, center-to-limb variation of the X-ray spectrum, and Compton backscatter in a coherent fashion. The results of this study are compared with observational data. Because of the large contribution from backscatter, for an anisotropic primary X-ray source which is due to bremsstrahlung of accelerated electrons moving predominantly down toward the photosphere, the observed X-ray flux around 30 keV does not depend significantly on the position of flare on the Sun. For such an anisotropic source, the X-ray spectrum observed in the 15-50 keV range becomes steeper with the increasing heliocentric angle of the flare. These results are compatible with the data. The degree of polarization of the sum of the primary and reflected X-rays with energies between about 15 and 30 keV can be very large for anisotropic primary X-ray sources, but it is less than about 4% for isotropic sources. We also discuss the characteristics of the brightness distribution of the X-ray albedo patch created by the Compton backscatter. The height and anisotropy of the primary hard X-ray source might be inferred from the study of the albedo patch

Finite Element Analysis of Flexural Vibrations in Hard Disk Drive Spindle Systems

Science.gov (United States)

LIM, SEUNGCHUL

2000-06-01

This paper is concerned with the flexural vibration analysis of the hard disk drive (HDD) spindle system by means of the finite element method. In contrast to previous research, every system component is here analytically modelled taking into account its structural flexibility and also the centrifugal effect particularly on the disk. To prove the effectiveness and accuracy of the formulated models, commercial HDD systems with two and three identical disks are selected as examples. Then their major natural modes are computed with only a small number of element meshes as the shaft rotational speed is varied, and subsequently compared with the existing numerical results obtained using other methods and newly acquired experimental ones. Based on such a series of studies, the proposed method can be concluded as a very promising tool for the design of HDDs and various other high-performance computer disk drives such as floppy disk drives, CD ROM drives, and their variations having spindle mechanisms similar to those of HDDs.

Upgrading multilayer zone plate technology for hard x-ray focusing

Energy Technology Data Exchange (ETDEWEB)

Hirotomo, Toshiki; Konishi, Shigeki [Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297 (Japan); SPring-8 Service Co., Ltd (Japan); Takano, Hidekazu, E-mail: htakano@sci.u-hyogo.ac.jp; Sumida, Kazuhiro; Tsusaka, Yoshiyuki; Kagoshima, Yasushi [Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297 (Japan); Koyama, Takahisa [Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297 (Japan); Japan Synchrotron Radiation Research Institute (JASRI/SPring-8) (Japan); Ichimaru, Satoshi; Ohchi, Tadayuki [NTT Advanced Technology Corporation (Japan); Takenaka, Hisataka [NTT Advanced Technology Corporation (Japan); TOYAMA Corporation (Japan)

2016-01-28

Multilayer zone plate (MZP) technology for hard X-ray focusing was upgraded and its focusing performance was evaluated using 20-keV X-rays at the synchrotron beamline (BL24XU) of SPring-8. The MZP consists of MoSi{sub 2} and Si layers alternately deposited on a glass fiber by magnetron sputtering so that all zone boundaries satisfy the Fresnel zone configuration. The focused beam was evaluated using knife-edge scanning in which the measured intensity distribution is identical to the line spread function (LSF) in the focal plane. The focused beamsize of about 30 nm was estimated by oscillation peaks observed in the measured LSF according to Rayleigh’s criterion.

Blazars in Hard X-rays

Science.gov (United States)

Ghisellini, Gabriele

2009-05-01

Although blazars are thought to emit most of their luminosity in the γ-ray band, there are subclasses of them very prominent in hard X-rays. These are the best candidates to be studied by Simbol-X. They are at the extremes of the blazar sequence, having very small or very high jet powers. The former are the class of TeV emitting BL Lacs, whose synchrotron emission often peaks at tens of keV or more. The latter are the blazars with the most powerful jets, have high black hole masses accreting at high (i.e. close to Eddington) rates. These sources are predicted to have their high energy peak even below the MeV band, and therefore are very promising candidates to be studied with Simbol-X.

A novel probe of intrinsic electronic structure: hard X-ray photoemission spectroscopy

International Nuclear Information System (INIS)

Takata, Y.; Tamasaku, K.; Nishino, Y.; Miwa, D.; Yabashi, M.; Ikenaga, E.; Horiba, K.; Arita, M.; Shimada, K.; Namatame, H.; Nohira, H.; Hattori, T.; Soedergren, S.; Wannberg, B.; Taniguchi, M.; Shin, S.; Ishikawa, T.; Kobayashi, K.

2005-01-01

We have realized hard X-ray (HX) photoemission spectroscopy (PES) with high throughput and high-energy resolution for core level and valence band studies using high-energy and high-brilliance synchrotron radiation at SPring-8. This is a brand new method because large escape depth of high-energy photoelectrons enables us to probe intrinsic bulk states free from surface condition. By use of a newly developed electron energy analyzer and well-focused X-rays, high-energy resolution of 75 meV (E/ΔE 79,000) was realized for 5.95 keV photoelectrons

Bulk sensitive hard x-ray photoemission electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Patt, M., E-mail: m.patt@fz-juelich.de; Wiemann, C. [Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich (Germany); Weber, N.; Escher, M.; Merkel, M. [Focus GmbH, Neukirchner Str. 2, D-65510 Hünstetten (Germany); Gloskovskii, A.; Drube, W. [DESY Photon Science, Deutsches Elektronen-Synchrotron, D-22603 Hamburg (Germany); Schneider, C. M. [Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich (Germany); Fakultät f. Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universität Duisburg-Essen, D-47048 Duisburg (Germany)

2014-11-15

Hard x-ray photoelectron spectroscopy (HAXPES) has now matured into a well-established technique as a bulk sensitive probe of the electronic structure due to the larger escape depth of the highly energetic electrons. In order to enable HAXPES studies with high lateral resolution, we have set up a dedicated energy-filtered hard x-ray photoemission electron microscope (HAXPEEM) working with electron kinetic energies up to 10 keV. It is based on the NanoESCA design and also preserves the performance of the instrument in the low and medium energy range. In this way, spectromicroscopy can be performed from threshold to hard x-ray photoemission. The high potential of the HAXPEEM approach for the investigation of buried layers and structures has been shown already on a layered and structured SrTiO{sub 3} sample. Here, we present results of experiments with test structures to elaborate the imaging and spectroscopic performance of the instrument and show the capabilities of the method to image bulk properties. Additionally, we introduce a method to determine the effective attenuation length of photoelectrons in a direct photoemission experiment.

A model independent method to deconvolve hard X-ray spectra

International Nuclear Information System (INIS)

Polcaro, V.F.; Bazzano, A.; Ubertini, P.; La Padula, C.

1984-01-01

A general purpose method to deconvolve the energy spectra detected by means of the use of a hard X-ray telescope is described. The procedure does not assume any form of input spectrum and the observed energy loss spectrum is directly deconvolved into the incident photon spectrum, the form of which can be determined independently of physical interpretation of the data. Deconvolution of the hard X-ray spectrum of Her X-1, detected during the HXR 81M experiment, by the method independent method is presented. (orig.)

Hard X-ray Vela supernova observation on rocket experiment WRX-R

Science.gov (United States)

Stehlikova, V.; Urban, M.; Nentvich, O.; Daniel, V.; Sieger, L.; Tutt, J.

2017-07-01

This paper presents a hard X-ray telescope for the Vela nebula observation during a sounding rocket flight. The Water Recovery X-ray Rocket (WRX-R) experiment is organised by the Pennsylvania State University (PSU), USA with a primary payload of a soft X-ray spectroscope. The Czech team developed a hard X-ray Lobster-eye telescope as a secondary payload. The Czech experiment’s astrophysical object of study is the Vela pulsar in the centre of the Vela nebula.

2TB hard disk drive

CERN Multimedia

This particular object was used up until 2012 in the Data Centre. It slots into one of the Disk Server trays. Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes (link is external). They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known as "hard disks" to distinguish them from "floppy disks (link is external)." Hard disks have a hard platter that holds the magnetic medium, as opposed to the flexible plastic film found in tapes and floppies.

Observation of hard X-rays line emission from Her X-1

Energy Technology Data Exchange (ETDEWEB)

Polcaro, V.F.; Bazzano, A.; la Padula, C.; Ubertini, P.; Vialetto, G.; Manchanda, R.K.; Damle, S.V.

1982-04-01

We present the results of a hard X-ray measurement of the binary source Her X-1, carried out with a balloon borne X-ray telescope consisting of two Multiwire Proportional Counters, having 900 cm/sup 2/ sensitive area each and spectral resolution of 15% and 24% FWHM respectively at 60 keV. The source was observed during the 'Mid-on' state. Our data confirm the previously reported high energy emission line overimposed on the low energy thermal spectrum.

A Hard X-Ray Power-Law Spectral Cutoff in Centaurus X-4

DEFF Research Database (Denmark)

Chakrabarty, Deepto; Tomsick, John A.; Grefenstette, Brian W.

2015-01-01

The low-mass X-ray binary Cen X-4 is the brightest and closest (<1.2 kpc) quiescent neutron star transient. Previous 0.5-10 keV X-ray observations of Cen X-4 in quiescence identified two spectral components: soft thermal emission from the neutron star atmosphere and a hard power-law tail of unkno...... behavior with PSR J1023+0038, IGR J18245-2452, and XSS J12270-4859, which have shown transitions between LMXB and radio pulsar modes at a similar X-ray luminosity....

Non-thermal Hard X-Ray Emission from Coma and Several Abell Clusters

International Nuclear Information System (INIS)

Correa, C

2004-01-01

We report results of hard X-Ray observations of the clusters Coma, Abell 496, Abell754, Abell 1060, Abell 1367, Abell2256 and Abell3558 using RXTE data from the NASA HEASARC public archive. Specifically we searched for clusters with hard x-ray emission that can be fitted by a power law because this would indicate that the cluster is a source of non-thermal emission. We are assuming the emission mechanism proposed by Vahk Petrosian where the inter cluster space contains clouds of relativistic electrons that by themselves create a magnetic field and emit radio synchrotron radiation. These relativistic electrons Inverse-Compton scatter Microwave Background photons up to hard x-ray energies. The clusters that were found to be sources of non-thermal hard x-rays are Coma, Abell496, Abell754 and Abell 1060

Hard X-ray Sources for the Mexican Synchrotron Project

International Nuclear Information System (INIS)

Reyes-Herrera, Juan

2016-01-01

One of the principal tasks for the design of the Mexican synchrotron was to define the storage ring energy. The main criteria for choosing the energy come from studying the electromagnetic spectrum that can be obtained from the synchrotron, because the energy range of the spectrum that can be obtained will determine the applications available to the users of the future light source. Since there is a public demand of hard X-rays for the experiments in the synchrotron community users from Mexico, in this work we studied the emission spectra from some hard X-ray sources which could be the best options for the parameters of the present Mexican synchrotron design. The calculations of the flux and the brightness for one Bending Magnet and four Insertion Devices are presented; specifically, for a Superconducting Bending Magnet (SBM), a Superconducting Wiggler (SCW), an In Vacuum Short Period Undulator (IV-SPU), a Superconducting Undulator (SCU) and for a Cryogenic Permanent Magnet Undulator (CPMU). Two commonly available synchrotron radiation programs were used for the computation (XOP and SRW). From the results, it can be concluded that the particle beam energy from the current design is enough to have one or more sources of hard X-rays. Furthermore, a wide range of hard X-ray region can be covered by the analyzed sources, and the choice of each type should be based on the specific characteristics of the X-ray beam to perform the experiments at the involved beamline. This work was done within the project Fomix Conacyt-Morelos ”Plan Estrategico para la construccion y operación de un Sincrotron en Morelos” (224392). (paper)

Hard X-ray Sources for the Mexican Synchrotron Project

Science.gov (United States)

Reyes-Herrera, Juan

2016-10-01

One of the principal tasks for the design of the Mexican synchrotron was to define the storage ring energy. The main criteria for choosing the energy come from studying the electromagnetic spectrum that can be obtained from the synchrotron, because the energy range of the spectrum that can be obtained will determine the applications available to the users of the future light source. Since there is a public demand of hard X-rays for the experiments in the synchrotron community users from Mexico, in this work we studied the emission spectra from some hard X-ray sources which could be the best options for the parameters of the present Mexican synchrotron design. The calculations of the flux and the brightness for one Bending Magnet and four Insertion Devices are presented; specifically, for a Superconducting Bending Magnet (SBM), a Superconducting Wiggler (SCW), an In Vacuum Short Period Undulator (IV-SPU), a Superconducting Undulator (SCU) and for a Cryogenic Permanent Magnet Undulator (CPMU). Two commonly available synchrotron radiation programs were used for the computation (XOP and SRW). From the results, it can be concluded that the particle beam energy from the current design is enough to have one or more sources of hard X-rays. Furthermore, a wide range of hard X-ray region can be covered by the analyzed sources, and the choice of each type should be based on the specific characteristics of the X-ray beam to perform the experiments at the involved beamline. This work was done within the project Fomix Conacyt-Morelos ”Plan Estrategico para la construccion y operación de un Sincrotron en Morelos” (224392).

Recent applications of hard x-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Weiland, Conan; Woicik, Joseph C., E-mail: Joseph.Woicik@NIST.gov [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Rumaiz, Abdul K. [National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973 (United States); Pianetta, Piero [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States)

2016-05-15

Recent applications of hard x-ray photoelectron spectroscopy (HAXPES) demonstrate its many capabilities in addition to several of its limitations. Examples are given, including measurement of buried interfaces and materials under in situ or in operando conditions, as well as measurements under x-ray standing-wave and resonant excitation. Physical considerations that differentiate HAXPES from photoemission measurements utilizing soft x-ray and ultraviolet photon sources are also presented.

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

DEFF Research Database (Denmark)

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

1995-01-01

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

X-Ray Timing Analysis of Cyg X-3 Using AstroSat/LAXPC: Detection of Milli-hertz Quasi-periodic Oscillations during the Flaring Hard X-Ray State

Energy Technology Data Exchange (ETDEWEB)

Pahari, Mayukh; Misra, Ranjeev [Inter-University Center for Astronomy and Astrophysics, Ganeshkhind, Pune 411007 (India); Antia, H M; Yadav, J S; Chauhan, Jai Verdhan; Chitnis, V R; Dedhia, Dhiraj; Katoch, Tilak; Madhwani, P; Shah, Parag [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Agrawal, P C [UM-DAE Center of Excellence for Basic Sciences, University of Mumbai, Kalina, Mumbai 400098 (India); Manchanda, R K [University of Mumbai, Kalina, Mumbai 400098 (India); Paul, B, E-mail: mayukh@iucaa.in [Department of Astronomy and Astrophysics, Raman Research Institute, Bengaluru 560080 (India)

2017-11-01

We present here results from the X-ray timing and spectral analysis of the X-ray binary Cyg X-3 using observations from the Large Area X-ray proportional Counter on board AstroSat . Consecutive light curves observed over a period of one year show the binary orbital period of 17253.56 ± 0.19 s. Another low-amplitude, slow periodicity of the order of 35.8 ± 1.4 days is observed, which may be due to the orbital precession as suggested earlier by Molteni et al. During the rising binary phase, power density spectra from different observations during the flaring hard X-ray state show quasi-periodic oscillations (QPOs) at ∼5–8 mHz, ∼12–14 mHz, and ∼18–24 mHz frequencies at the minimum confidence of 99%. However, during the consecutive binary decay phase, no QPO is detected up to 2 σ significance. Energy-dependent time-lag spectra show soft lag (soft photons lag hard photons) at the mHz QPO frequency and the fractional rms of the QPO increases with the photon energy. During the binary motion, the observation of mHz QPOs during the rising phase of the flaring hard state may be linked to the increase in the supply of the accreting material in the disk and corona via stellar wind from the companion star. During the decay phase, the compact source moves in the outer wind region causing the decrease in supply of material for accretion. This may cause weakening of the mHz QPOs below the detection limit. This is also consistent with the preliminary analysis of the orbital phase-resolved energy spectra presented in this paper.

A hard x-ray prototype production exposure station at NSLS

International Nuclear Information System (INIS)

Johnson, E.D.; Milne, J.C.

1997-07-01

Exposures conducted at the NSLS R and D beamline (X-27B) for High Aspect Ratio Precision Manufacture have proven sufficiently successful that the authors are constructing a dedicated hard x-ray exposure beamline. The new beamline (X-14B) provides an exposure field ∼ 120 mm wide, three times larger than that of X-27B. The scanner is based on the hydraulic system from the X-27B program. It is optimized for planar exposures and takes advantage of the full 525 mm stroke available. Exposures of multiple substrates and masks will be possible, with the fixturing supporting mounting of substrate holders from other groups (ALS, APS, CAMD, and UW). The function of this beamline is to establish a hard x-ray exposure station where manufacturing scale protocols can be developed and ultimately exploited for production runs

The hard X-ray spectrum of Cyg X-1 during the transition in November 1975

International Nuclear Information System (INIS)

Sommer, M.; Maurus, H.; Urbach, R.

1976-01-01

Some observations are reported of the hard X-ray spectrum of Cyg X-1 during a transition to the high state in November 1975, made with a balloon-borne X-ray detector. The range covered was 25 to 150 keV. The data obtained appeared to confirm the characteristic spectral time variation, and suggested a single power law spectrum from 3 to 80 keV, with an increasing spectral index during the upward transition to the high state. A power spectrum is expected if it is assumed that the universe Compton effect is the basic mechanism that produces the hard X-ray tail of Cyg X-1. Spectral time variation may be caused by a varying intensity of an inner soft photon source within a stable hot cloud. (U.K.)

Design and Tests of the Hard X-ray Polarimeter X-Calibur

Directory of Open Access Journals (Sweden)

M. Beilicke

2014-12-01

Full Text Available X-ray polarimetry promises to give qualitatively new information bout high-energy astrophysical sources, such as binary black hole  systems, micro-quasars, active galactic nuclei, and gamma-ray bursts. We designed, built and tested ahard X-ray polarimeter, X-Calibur, to be used in the focal plane of the InFOCuS grazing incidence hard X-ray telescope.X-Calibur combines a low-Z Compton scatterer with a CZT detector assembly to measure the polarization of 20−60 keV X-rays making use of the fact that polarized photons Compton scatter preferentially perpendicular to the electric field orientation; in principal, a similar space-borne experiment could be operated in the 5−100 keV regime. X-Calibur achieves a high detection efficiency of order unity.

High spectral resolution measurements of a solar flare hard X-ray burst

International Nuclear Information System (INIS)

Lin, R.P.; Schwartz, R.A.; NASA, Goddard Space Flight Center, Greenbelt, MD)

1987-01-01

Observations are reported of an intense solar flare hard X-ray burst on June 27, 1980, made with a balloon-borne array of liquid nitrogen-cooled Ge detector which provided unprecedented spectral resolution (no more than 1 keV FWHM). The hard X-ray spectra throughout the impulsive phase burst fitted well to a double power-law form, and emission from an isothermal 0.1-1 billion K plasma can be specifically excluded. The temporal variations of the spectrum indicate that the hard X-ray burst is made up of two superposed components: individual spikes lasting about 3-15 sec, which have a hard spectrum and a break energy of 30-65 keV; and a slowly varying component characterized by a soft spectrum with a constant low-energy slope and a break energy which increases from 25 kev to at least 100 keV through the event. The double power-law shape indicates that DC electric field acceleration, similar to that occurring in the earth's auroral zone, may be the source of the energetic electrons which produce the hard X-ray emission. 39 references

Femtosecond response of polyatomic molecules to ultra-intense hard X-rays.

Science.gov (United States)

Rudenko, A; Inhester, L; Hanasaki, K; Li, X; Robatjazi, S J; Erk, B; Boll, R; Toyota, K; Hao, Y; Vendrell, O; Bomme, C; Savelyev, E; Rudek, B; Foucar, L; Southworth, S H; Lehmann, C S; Kraessig, B; Marchenko, T; Simon, M; Ueda, K; Ferguson, K R; Bucher, M; Gorkhover, T; Carron, S; Alonso-Mori, R; Koglin, J E; Correa, J; Williams, G J; Boutet, S; Young, L; Bostedt, C; Son, S-K; Santra, R; Rolles, D

2017-06-01

X-ray free-electron lasers enable the investigation of the structure and dynamics of diverse systems, including atoms, molecules, nanocrystals and single bioparticles, under extreme conditions. Many imaging applications that target biological systems and complex materials use hard X-ray pulses with extremely high peak intensities (exceeding 10 20 watts per square centimetre). However, fundamental investigations have focused mainly on the individual response of atoms and small molecules using soft X-rays with much lower intensities. Studies with intense X-ray pulses have shown that irradiated atoms reach a very high degree of ionization, owing to multiphoton absorption, which in a heteronuclear molecular system occurs predominantly locally on a heavy atom (provided that the absorption cross-section of the heavy atom is considerably larger than those of its neighbours) and is followed by efficient redistribution of the induced charge. In serial femtosecond crystallography of biological objects-an application of X-ray free-electron lasers that greatly enhances our ability to determine protein structure-the ionization of heavy atoms increases the local radiation damage that is seen in the diffraction patterns of these objects and has been suggested as a way of phasing the diffraction data. On the basis of experiments using either soft or less-intense hard X-rays, it is thought that the induced charge and associated radiation damage of atoms in polyatomic molecules can be inferred from the charge that is induced in an isolated atom under otherwise comparable irradiation conditions. Here we show that the femtosecond response of small polyatomic molecules that contain one heavy atom to ultra-intense (with intensities approaching 10 20 watts per square centimetre), hard (with photon energies of 8.3 kiloelectronvolts) X-ray pulses is qualitatively different: our experimental and modelling results establish that, under these conditions, the ionization of a molecule is

Recurrent pulse trains in the solar hard X-ray flare of 1980 June 7

International Nuclear Information System (INIS)

Kiplinger, A.L.; Dennis, B.R.; Frost, K.J.; Orwig, L.E.

1983-01-01

This study presents a detailed examination of the solar hard X-ray and γ-ray flare of 1980 June 7 as seen by the Hard X-Ray Burst Spectrometer on SMM. The hard X-ray profile is most unusual in that it is characterized by an initial pulse train of seven intense hard X-ray spikes. However, the event is unique among the 6300 events observed by HXRBS in that the temporal signature of this pulse train recurs twice during the flare. Such signatures of temporal stability in impulsive solar flares have not been observed before. Examinations of the hard X-ray data in conjunction with radio and γ-ray observations show that the 28--480 keV X-ray emission is simultaneous with the 17 GHz microwave fluxes within 128 ms and that the 3.5--6.5 MeV prompt γ-ray line emission is coincident with secondary maxima of the microwave and X-ray fluxes. Studies of the temporal and spectral properties of the pulses indicate that the pulses are not produced by purely reversible processes, and that if the source is oscillatory, it is not a high quality oscillator. Although the absence of spatially resolved hard X-ray observations leaves other possibilities open, a parameterization of the event as a set of seven sequentially firing loops is presented that offers many satisfying explanations of the observations

Hard X-ray Flux from Low-Mass Stars in the Cygnus OB2 Association

Science.gov (United States)

Caramazza, M.; Drake, J. J.; Micela, G.; Flaccomio, E.

2009-05-01

We investigate the X-ray emission in the 20-40 keV band expected from the flaring low-mass stellar population in Cygnus OB2 assuming that the observed soft X-ray emission is due to a superposition of flares and that the ratio of hard X-ray to soft X-ray emission is described by a scaling found for solar flares by Isola and co-workers. We estimate a low-mass stellar hard X-ray flux in the 20-40 keV band in the range ~7×1031-7×1033 erg/s and speculate the limit of this values. Hard X-ray emission could lie at a level not much below the current observed flux upper limits for Cygnus OB2. Simbol-X, with its broad energy band (10-100 keV) and its sensitivity should be able to detect this emission and would provide insights into the hard X-ray production of flares on pre-main sequence stars.

Studies in useful hard x-ray induced chemistry

Science.gov (United States)

Pravica, Michael; Bai, Ligang; Sneed, Daniel; Park, Changyong

2013-06-01

The observed rapid decomposition of potassium chlorate (via 2KClO3 + h ν --> 2KCl +3O2) via synchrotron hard x-ray irradiation (>10 keV) has enabled experiments that are developing novel and useful hard x-ray chemistry. We have observed a number of radiation-induced in situ decomposition reactions in various substances which release O2, H2, N2, NH3, and H2O in a diamond anvil cell (DAC) at ambient and high pressures. These novel acatalytic and isothermal reactions represent a highly controllable, penetrating, and focused method to initiate chemistry (including x-ray induced combustion) in sealed and/or isolated chambers which maintain matter under extreme conditions. During our studies, we have typically observed a slowing of decomposition with pressure including phase dependent decomposition of KClO3. Energy dependent studies have observed an apparent resonance near 15 keV at which the decomposition rate is maximized. This may enable use of much lower flux and portable x-ray sources (e.g. x-ray tubes) in larger scale experiments. These developments support novel means to load DACs and control chemical reactions providing novel routes of synthesis of novel materials under extreme conditions.

CORRELATION OF HARD X-RAY AND WHITE LIGHT EMISSION IN SOLAR FLARES

Energy Technology Data Exchange (ETDEWEB)

Kuhar, Matej; Krucker, Säm; Battaglia, Marina; Kleint, Lucia; Casadei, Diego [University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch (Switzerland); Oliveros, Juan Carlos Martinez; Hudson, Hugh S. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States)

2016-01-01

A statistical study of the correlation between hard X-ray and white light emission in solar flares is performed in order to search for a link between flare-accelerated electrons and white light formation. We analyze 43 flares spanning GOES classes M and X using observations from the Reuven Ramaty High Energy Solar Spectroscopic Imager and Helioseismic and Magnetic Imager. We calculate X-ray fluxes at 30 keV and white light fluxes at 6173 Å summed over the hard X-ray flare ribbons with an integration time of 45 s around the peak hard-X ray time. We find a good correlation between hard X-ray fluxes and excess white light fluxes, with a highest correlation coefficient of 0.68 for photons with energy of 30 keV. Assuming the thick target model, a similar correlation is found between the deposited power by flare-accelerated electrons and the white light fluxes. The correlation coefficient is found to be largest for energy deposition by electrons above ∼50 keV. At higher electron energies the correlation decreases gradually while a rapid decrease is seen if the energy provided by low-energy electrons is added. This suggests that flare-accelerated electrons of energy ∼50 keV are the main source for white light production.

Bragg concentrators for hard (> 10 keV) X-ray astronomy: Status report

Energy Technology Data Exchange (ETDEWEB)

Pareschi, G.; Pasqualini, G. [Ferrara, Univ. (Italy). Dipt. di Fisica; Frontera, F. [CNR, Bologna (Italy). Istituto di TESRE]|[Ferrara, Univ. (Italy). Dipt. di Fisica

1997-09-01

The use of focusing telescopes in hard X-ray (E > 10 keV) astronomy will provide better flux sensitivity and imaging performances with respect to the direct-viewing detectors, utilized until now. They present recent results obtained from their group regarding the possible use of Bragg-diffraction technique to design hard X-ray focusing telescopes.

Bragg concentrators for hard (> 10 keV) X-ray astronomy: Status report

International Nuclear Information System (INIS)

Pareschi, G.; Pasqualini, G.; Frontera, F.; Ferrara, Univ.

1997-01-01

The use of focusing telescopes in hard X-ray (E > 10 keV) astronomy will provide better flux sensitivity and imaging performances with respect to the direct-viewing detectors, utilized until now. They present recent results obtained from their group regarding the possible use of Bragg-diffraction technique to design hard X-ray focusing telescopes

Hard X-ray Emission from Galaxy Clusters Observed with INTEGRAL and Prospects for Simbol-X

Science.gov (United States)

Eckert, D.; Paltani, S.; Courvoisier, T. J.-L.

2009-05-01

Some galaxy clusters are known to contain a large population of relativistic electrons, which produce radio emission through synchrotron radiation. Therefore, it is expected that inverse-Compton scattering of the relativistic electrons with the CMB produce non-thermal emission which should be observable in the hard X-ray domain. Here we focus on the recent results by INTEGRAL, which shed a new light on the non-thermal emission thanks to its angular resolution and sensitivity in the hard X-ray range. We also present the exciting prospects in this field for Simbol-X, which will allow us to detect the non-thermal emission in a number of clusters and map the magnetic field throughout the intra-cluster medium.

Application of thermoluminescence dosimeter on the measurement of hard X-ray pulse energy spectrum

International Nuclear Information System (INIS)

Song Zhaohui; Wang Baohui; Wang Kuilu; Hei Dongwei; Sun Fengrong; Li Gang

2003-01-01

This paper introduces the application of thermoluminescence dosimeter (TLD) which composed by TLD-3500 reader and GR-100 M chips on the measurement of hard X-ray pulse energy spectrum. The idea using Filter Fluorescence Method (FFM) and TLD to measure hard X-ray pulse energy spectrum (from 10 keV to 100 keV) is discussed in details. Considering all the factors of the measuring surrounding, the measurement system of hard X-ray pulse has been devised. The calibration technique of absolute energy response of TLD is established. This method has been applied successfully on the radiation parameters measurement of the huge pulse radiation device-high-power pulser I. Hard X-ray pulse energy spectrum data of the pulser are acquired

Hard X-ray bursts and DD microfusion neutrons from complex ...

Indian Academy of Sciences (India)

explosive destruction of micrograins is accompanied by X-ray radiation (during hydrody- ... makes it possible to produce lasing in hard X-rays due to the effects of multiple scattering ... portant, information on the X-ray random media, including some indirect diagnostics. In ... stages of ionization in the total flux of particles.

The Elusive Soft Emission from Hard X-ray Symbiotic System RT Cru

Science.gov (United States)

Karovska, Margarita

2014-09-01

RT Cru is a fascinating member of a new class of hard X-ray emitting symbiotic binaries showing X-ray emission extending to over 50keV. While its hard X-ray emission has been studied in detail, the soft component of the spectrum, including flares, remains elusive, since previous observations have focused on the high-energy regime. We propose Chandra HRC-S/LETG observations to determine the spatial, spectral, and temporal characteristics of the source of the soft X-ray emission with a goal to establish the origin of the soft component, and determine whether and how it is tied to the hard component. Determining the origin of the soft emission is a crucial piece of the puzzle to understanding the geometry, energetics, and the environment of WD accretion in this class of symbiotic systems.

Simbol-X: Imaging The Hard X-ray Sky with Unprecedented Spatial Resolution and Sensitivity

Science.gov (United States)

Tagliaferri, Gianpiero; Simbol-X Joint Scientific Mission Group

2009-01-01

Simbol-X is a hard X-ray mission, with imaging capability in the 0.5-80 keV range. It is based on a collaboration between the French and Italian space agencies with participation of German laboratories. The launch is foreseen in late 2014. It relies on a formation flight concept, with two satellites carrying one the mirror module and the other one the focal plane detectors. The mirrors will have a 20 m focal length, while the two focal plane detectors will be put one on top of the other one. This combination will provide over two orders of magnitude improvement in angular resolution and sensitivity in the hard X-ray range with respect to non-focusing techniques. The Simbol-X revolutionary instrumental capabilities will allow us to elucidate outstanding questions in high energy astrophysics such as those related to black-holes accretion physics and census, and to particle acceleration mechanisms. We will give an overall description of the mission characteristics, performances and scientific objectives.

8x8 and 10x10 Hyperspace Representations of SU(3) and 10-fold Point-Symmetry Group of Quasicrystals

Science.gov (United States)

Animalu, Alexander

2012-02-01

In order to further elucidate the unexpected 10-fold point-symmetry group structure of quasi-crystals for which the 2011 Nobel Prize in chemistry was awarded to Daniel Shechtman, we explore a correspondence principle between the number of (projective) geometric elements (points[vertices] + lines[edges] + planes[faces]) of primitive cells of periodic or quasi-periodic arrangement of hard or deformable spheres in 3-dimensional space of crystallography and elements of quantum field theory of particle physics [points ( particles, lines ( particles, planes ( currents] and hence construct 8x8 =64 = 28+36 = 26 + 38, and 10x10 =100= 64 + 36 = 74 + 26 hyperspace representations of the SU(3) symmetry of elementary particle physics and quasicrystals of condensed matter (solid state) physics respectively, As a result, we predict the Cabibbo-like angles in leptonic decay of hadrons in elementary-particle physics and the observed 10-fold symmetric diffraction pattern of quasi-crystals.

Hard x- and gamma-rays from supernova 1987A

International Nuclear Information System (INIS)

Kumagai, S.; Shigeyama, T.; Nomoto, K.; Nishmura, J.; Itoh, M.

1988-01-01

The x-ray light curve and spectrum from SN 1987A due to Compton degradation of γ-rays from the 56 Co decay are calculated and compared with the Ginga and Kvant observations. If mixing of 56 Co into outer layers has taken place, the x-rays emerge much earlier than in the case without mixing and the resulting hard x-rays are in reasonable agreement with observations

Bonded Multilayer Laue Lens for focusing hard X-rays

International Nuclear Information System (INIS)

Liu Chian; Conley, R.; Qian, J.; Kewish, C.M.; Macrander, A.T.; Maser, J.; Kang, H.C.; Yan, H.; Stephenson, G.B.

2007-01-01

We have fabricated partial Multilayer Laue Lens (MLL) linear zone plate structures with thousands of alternating WSi 2 and Si layers and various outermost zone widths according to the Fresnel zone plate formula. Using partial MLL structures, we were able to focus hard X-rays to line foci with a width of 30 nm and below. Here, we describe challenges and approaches used to bond these multilayers to achieve line and point focusing. Bonding was done by coating two multilayers with AuSn and heating in a vacuum oven at 280-300 o C. X-ray reflectivity measurements confirmed that there was no change in the multilayers after heating to 350 o C. A bonded MLL was polished to a 5-25 μm wedge without cracking. SEM image analyses found well-positioned multilayers after bonding. These results demonstrate the feasibility of a bonded full MLL for focusing hard X-rays

Crab Nebula Variations in Hard X-rays

Science.gov (United States)

Wilson-Hodge, Colleen A.

2012-01-01

The Crab Nebula was surprisingly variable from 2001-2010, with less variability before 2001 and since mid-2010. We presented evidence for spectral softening from RXTE, Swift/BAT, and Fermi GBM during the mid-2008-2010 flux decline. We see no clear connections between the hard X-ray variations and the GeV flares

Structure, elastic stiffness, and hardness of Os 1- xRu xB 2 solid solution transition-metal diborides

KAUST Repository

Kanoun, Mohammed; Hermet, Patrick; Goumri-Said, Souraya

2012-01-01

On the basis of recent experiments, the solid solution transition-metal diborides were proposed to be new ultra-incompressible hard materials. We investigate using density functional theory based methods the structural and mechanical properties, electronic structure, and hardness of Os 1-xRu xB 2 solid solutions. A difference in chemical bonding occurs between OsB 2 and RuB 2 diborides, leading to significantly different elastic properties: a large bulk, shear moduli, and hardness for Os-rich diborides and relatively small bulk, shear moduli, and hardness for Ru-rich diborides. The electronic structure and bonding characterization are also analyzed as a function of Ru-dopant concentration in the OsB 2 lattice. © 2012 American Chemical Society.

Structure, elastic stiffness, and hardness of Os 1- xRu xB 2 solid solution transition-metal diborides

KAUST Repository

Kanoun, Mohammed

2012-05-31

On the basis of recent experiments, the solid solution transition-metal diborides were proposed to be new ultra-incompressible hard materials. We investigate using density functional theory based methods the structural and mechanical properties, electronic structure, and hardness of Os 1-xRu xB 2 solid solutions. A difference in chemical bonding occurs between OsB 2 and RuB 2 diborides, leading to significantly different elastic properties: a large bulk, shear moduli, and hardness for Os-rich diborides and relatively small bulk, shear moduli, and hardness for Ru-rich diborides. The electronic structure and bonding characterization are also analyzed as a function of Ru-dopant concentration in the OsB 2 lattice. © 2012 American Chemical Society.

Characterisation of weldment hardness, impact energy and microstructure in API X65 steel

International Nuclear Information System (INIS)

Hashemi, S.H.; Mohammadyani, D.

2012-01-01

The variation of microstructure and mechanical properties in various sub-zones of double submerged arc welded line pipe steel of grade API X65 was investigated. Instrumented Charpy V-notch tests and Vickers hardness experiments were conducted on the fusion zone, base metal and heat affected zone of the weld joint in 14.3 mm thick, 1219 mm outside diameter spiral pipeline. The lowest impact energy and the highest hardness level (160J and 218 HV, respectively) were recorded in the fusion zone. The low energy and high hardness characteristics of the seam weld can be attributed to its cast microstructure and the presence of grain boundary phases (such as proeutectoid ferrite), confirmed by standard metallographic observation. Despite this, service requirements set by the API 5L industry code (minimum impact energy of 73J, maximum hard spots of 350 HV) were fulfilled by the tested steel. Highlights: ► Experimental study of API X65 steel microstructure. ► Analysis of the relationship between X65 steel microstructure and hardness. ► Analysis of the relationship between X65 steel microstructure and impact energy. ► Presentation of detailed technical information on DSA welding in spiral pipes.

Measured reflectance of graded multilayer mirrors designed for astronomical hard X-ray telescopes

DEFF Research Database (Denmark)

Christensen, Finn Erland; Craig, W.W.; Windt, D.L.

2000-01-01

Future astronomical X-ray telescopes, including the balloon-borne High-Energy Focusing Telescope (HEFT) and the Constellation-X Hard X-ray Telescope (Con-X HXT) plan to incorporate depth-graded multilayer coatings in order to extend sensitivity into the hard X-ray (10 less than or similar to E less......-graded W/Si multilayers optimized for broadband performance up to 69.5 keV (WK-edge). These designs are ideal for both the HEFT and Con-X HXT applications. We compare the measurements to model calculations to demonstrate that the reflectivity can be well described by the intended power law distribution...

Adaptive Lobster-Eye Hard X-Ray Telescope, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — To address NASA needs for hard X-ray telescopes for starlight detection and wavefront analysis, Physical Optics Corporation (POC) proposes to develop an Adjustable...

Low Molecular Weight Z-Tetraol Boundary Lubricant Films in Hard Disk Drives

Directory of Open Access Journals (Sweden)

R. J. Waltman

2012-01-01

Full Text Available Lower molecular weight Z-Tetraol films exhibit increased mechanical spacing in the slider-disk interface due to a lower z-profile. An increased resistance to lubricant disturbance on the disk surface (e.g., lube moguls with decreasing film thickness is attributed to an increasing contribution from the polar component of the disjoining pressure. Evaporative loss at temperatures typically encountered in a hard-disk drive also increases with decreasing molecular weight but is strongly dependent on the initial bonded fraction.

Hard X-ray Microscopic Imaging Of Human Breast Tissues

Science.gov (United States)

Park, Sung H.; Kim, Hong T.; Kim, Jong K.; Jheon, Sang H.; Youn, Hwa S.

2007-01-01

X-ray microscopy with synchrotron radiation will be a useful tool for innovation of x-ray imaging in clinical and laboratory settings. It helps us observe detailed internal structure of material samples non-invasively in air. And, it also has the potential to solve some tough problems of conventional breast imaging if it could evaluate various conditions of breast tissue effectively. A new hard x-ray microscope with a spatial resolution better than 100 nm was installed at Pohang Light Source, a third generation synchrotron radiation facility in Pohang, Korea. The x-ray energy was set at 6.95 keV, and the x-ray beam was monochromatized by W/B4C monochromator. Condenser and objective zone plates were used as x-ray lenses. Zernike phase plate next to condenser zone plate was introduced for improved contrast imaging. The image of a sample was magnified 30 times by objective zone plate and 20 times by microscope objective, respectively. After additional 10 times digital magnification, the total magnifying power was up to 6000 times in the end. Phase contrast synchrotron images of 10-μm-thick female breast tissue of the normal, fibroadenoma, fibrocystic change and carcinoma cases were obtained. By phase contrast imaging, hard x-rays enable us to observe many structures of breast tissue without sample preparations such as staining or fixation.

Hard X-ray Microscopic Imaging Of Human Breast Tissues

International Nuclear Information System (INIS)

Park, Sung H.; Kim, Hong T.; Kim, Jong K.; Jheon, Sang H.; Youn, Hwa S.

2007-01-01

X-ray microscopy with synchrotron radiation will be a useful tool for innovation of x-ray imaging in clinical and laboratory settings. It helps us observe detailed internal structure of material samples non-invasively in air. And, it also has the potential to solve some tough problems of conventional breast imaging if it could evaluate various conditions of breast tissue effectively. A new hard x-ray microscope with a spatial resolution better than 100 nm was installed at Pohang Light Source, a third generation synchrotron radiation facility in Pohang, Korea. The x-ray energy was set at 6.95 keV, and the x-ray beam was monochromatized by W/B4C monochromator. Condenser and objective zone plates were used as x-ray lenses. Zernike phase plate next to condenser zone plate was introduced for improved contrast imaging. The image of a sample was magnified 30 times by objective zone plate and 20 times by microscope objective, respectively. After additional 10 times digital magnification, the total magnifying power was up to 6000 times in the end. Phase contrast synchrotron images of 10-μm-thick female breast tissue of the normal, fibroadenoma, fibrocystic change and carcinoma cases were obtained. By phase contrast imaging, hard x-rays enable us to observe many structures of breast tissue without sample preparations such as staining or fixation

A Hard X-Ray Study of the Normal Star-Forming Galaxy M83 with NuSTAR

DEFF Research Database (Denmark)

Yukita, M.; Hornschemeier, A. E.; Lehmer, B. D.

2016-01-01

We present the results from sensitive, multi-epoch NuSTAR observations of the late-type star-forming galaxy M83 (d = 4.6 Mpc). This is the first investigation to spatially resolve the hard (E > 10 keV) X-ray emission of this galaxy. The nuclear region and similar to 20 off-nuclear point sources......, including a previously discovered ultraluminous X-ray source, are detected in our NuSTAR observations. The X-ray hardnesses and luminosities of the majority of the point sources are consistent with hard X-ray sources resolved in the starburst galaxy NGC 253. We infer that the hard X-ray emission is most...

Imaging escape gated MPWC for hard X-ray astronomy

Energy Technology Data Exchange (ETDEWEB)

Ubertini, P.; Bazzano, A.; Boccaccini, L.; La Padula, C.; Mastropietro, M.; Patriarca, R.; Polcaro, V.F.; Barbareschi, L.; Perotti, F.; Villa, G.

1983-11-15

A scientific forward step in the hard X-ray and soft gamma-ray astronomy will only be possible with the use of a new generation of space borne instruments. Their main characteristics have to be the two-dimensional imaging capability over a large collecting area and the fine spectral resolution in order to discriminate between the weak signal coming from cosmic sources to be detected and the strong background induced by cosmic rays, in the space environment, on the detector. To reach this goal we have developed a new hard X-ray position sensitive proportional counter operating with the escape gate technique in the range 15-150 keV, to be used together with a pseudo-random coded mask in order to obtain sky images. The detector is a high pressure (5 bar) xenon-argon-isobutane filled chamber with a spatial resolution of 30x2 mm and a spectral resolution of 5% at 60 keV on the sensitive area of 3000 cm/sup 2/.

Hard X-ray Microscopy with Elemental, Chemical and Structural Contrast

International Nuclear Information System (INIS)

Schroer, C.G.; Boye, P.; Feldkamp, J.P.

2010-01-01

We review hard X-ray microscopy techniques with a focus on scanning microscopy with synchrotron radiation. Its strength compared to other microscopies is the large penetration depth of hard x rays in matter that allows one to investigate the interior of an object without destructive sample preparation. In combination with tomography, local information from inside of a specimen can be obtained, even from inside special non-ambient sample environments. Different X-ray analytical techniques can be used to produce contrast, such as X-ray absorption, fluorescence, and diffraction, to yield chemical, elemental, and structural information about the sample, respectively. This makes X-ray microscopy attractive to many fields of science, ranging from physics and chemistry to materials, geo-, and environmental science, biomedicine, and nanotechnology. Our scanning microscope based on nanofocusing refractive X-ray lenses has a routine spatial resolution of about 100 nm and supports the contrast mechanisms mentioned above. In combination with coherent X-ray diffraction imaging, the spatial resolution can be improved to the 10 nm range. The current state-of-the-art of this technique is illustrated by several examples, and future prospects of the technique are given. (author)

New hard X-ray sources at 380 declination

International Nuclear Information System (INIS)

Ubertini, P.; Bazzano, A.; La Padula, C.; Polcaro, V.F.

1981-01-01

We report the detection of three new hard X-rays sources emitting in the range 15-150 KeV. Their observation was carried out by means of a balloon borne payload, consisting of two large area high spectral resolution Multiwire Spectroscopic Proportional Counters. (orig.)

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

Science.gov (United States)

Toot, G. David

1989-01-01

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

Experimental Demonstration of X-Ray Drive Enhancement with Rugby-Shaped Hohlraums

International Nuclear Information System (INIS)

Philippe, F.; Casner, A.; Caillaud, T.; Landoas, O.; Monteil, M. C.; Liberatore, S.; Park, H. S.; Amendt, P.; Robey, H.; Sorce, C.; Li, C. K.; Seguin, F.; Rosenberg, M.; Petrasso, R.; Glebov, V.; Stoeckl, C.

2010-01-01

Rugby-shaped hohlraums have been suggested as a way to enhance x-ray drive in the indirect drive approach to inertial confinement fusion. This Letter presents an experimental comparison of rugby-shaped and cylinder hohlraums used for D 2 and D 3 He-filled capsules implosions on the Omega laser facility, demonstrating an increase of x-ray flux by 18% in rugby-shaped hohlraums. The highest yields to date for deuterium gas implosions in indirect drive on Omega (1.5x10 10 neutrons) were obtained, allowing for the first time the measurement of a DD burn history. Proton spectra measurements provide additional validation of the higher drive in rugby-shaped hohlraums.

CdTe Based Hard X-ray Imager Technology For Space Borne Missions

Science.gov (United States)

Limousin, Olivier; Delagnes, E.; Laurent, P.; Lugiez, F.; Gevin, O.; Meuris, A.

2009-01-01

CEA Saclay has recently developed an innovative technology for CdTe based Pixelated Hard X-Ray Imagers with high spectral performance and high timing resolution for efficient background rejection when the camera is coupled to an active veto shield. This development has been done in a R&D program supported by CNES (French National Space Agency) and has been optimized towards the Simbol-X mission requirements. In the latter telescope, the hard X-Ray imager is 64 cm² and is equipped with 625µm pitch pixels (16384 independent channels) operating at -40°C in the range of 4 to 80 keV. The camera we demonstrate in this paper consists of a mosaic of 64 independent cameras, divided in 8 independent sectors. Each elementary detection unit, called Caliste, is the hybridization of a 256-pixel Cadmium Telluride (CdTe) detector with full custom front-end electronics into a unique 1 cm² component, juxtaposable on its four sides. Recently, promising results have been obtained from the first micro-camera prototypes called Caliste 64 and will be presented to illustrate the capabilities of the device as well as the expected performance of an instrument based on it. The modular design of Caliste enables to consider extended developments toward IXO type mission, according to its specific scientific requirements.

The Variable Crab Nebula: Evidence for a Connection Between GeV Flares and Hard X-ray Variations

Science.gov (United States)

Wilson-Hodge, Colleen A.; Harding, A. K.; Hays, E. A.; Cherry, M. L.; Case, G. L.; Finger, M. H.; Jenke, P.; Zhang, X.

2016-01-01

In 2010, hard X-ray variations (Wilson-Hodge et al. 2011) and GeV flares (Tavani et al 2011, Abdo et al. 2011) from the Crab Nebula were discovered. Connections between these two phenomena were unclear, in part because the timescales were quite different, with yearly variations in hard X-rays and hourly to daily variations in the GeV flares. The hard X-ray flux from the Crab Nebula has again declined since 2014, much like it did in 2008-2010. During both hard X-ray decline periods, the Fermi LAT detected no GeV flares, suggesting that injection of particles from the GeV flares produces the much slower and weaker hard X-ray variations. The timescale for the particles emitting the GeV flares to lose enough energy to emit synchrotron photons in hard X-rays is consistent with the yearly variations observed in hard X-rays and with the expectation that the timescale for variations slowly increases with decreasing energy. This hypothesis also predicts even slower and weaker variations below 10 keV, consistent with the non-detection of counterparts to the GeV flares by Chandra (Weisskopf et al 2013). We will present a comparison of the observed hard X-ray variations and a simple model of the decay of particles from the GeV flares to test our hypothesis.

Resummations in QCD hard-scattering at large and small x

CERN Document Server

Kidonakis, Nikolaos; Stephens, Philip

2008-01-01

We discuss different resummations of large logarithms that arise in hard-scattering cross sections of quarks and gluons in regions of large and small x. The large-x logarithms are typically dominant near threshold for the production of a specified final state. These soft and collinear gluon corrections produce large enhancements of the cross section for many processes, notably top quark and Higgs production, and typically the higher-order corrections reduce the factorization and renormalization scale dependence of the cross section. The small-x logarithms are dominant in the regime where the momentum transfer of the hard sub-process is much smaller than the total collision energy. These logarithms are important to describe multijet final states in deep inelastic scattering and hadron colliders, and in the study of parton distribution functions. The resummations at small and large x are linked by the eikonal approximation and are dominated by soft gluon anomalous dimensions. We will review their role in both c...

Study of fast electrons from hard-X radiation; Etude des electrons rapides a partir du rayonnement X-dur

Energy Technology Data Exchange (ETDEWEB)

Arslanbekov, R.

1995-12-19

The goal of this thesis is the study of fast electron dynamics by means of the hard X-ray diagnosis installed in TORE SUPRA and numerical simulations. Fast electrons are generated in the plasma in the presence of the injected lower hybrid (LH) waves. Two aspects are studied in detail: the lower hybrid wave propagation and absorption in a periodically perturbed media and 2-D Fokker-Planck modelling of the fast electron dynamics in the presence of the LH power. Ripple effects on lower hybrid wave propagation and absorption are investigated using the ray tracing technique. A cylindrical equilibrium is first studied and a strong modification of the ray dynamics is predicted. Calculations are carried out in a real toroidal geometry corresponding to TORE SUPRA. It is shown that the lack of toroidal axisymmetry of the magnetic field may result in a modification of the ray evolution even if the global ray evolution is governed by the larger poloidal inhomogeneity. Simulation of LH experiments are performed for TORE SUPRA tokamak which has a large magnetic ripple (7% at the plasma edge). By considering ripple perturbation in LH current drive simulations, a better agreement is found with experimental results, in particular with the hard-X spectra and the current density profiles. In the second part of the thesis, a 2-D modeling of the fast electron dynamics in the velocity phase space is considered, based on the 2-D relativistic electron Fokker-Planck equation. Electron distribution functions obtained are used to calculate non-thermal Bremsstrahlung emission for different TORE SUPRA shots in a wide range of experimental conditions. (J.S.). 168 refs., 93 figs., 1 tab., 3 appendix.

The application of thermoluminescence dosimeter on the measurement of hard X-ray pulse energy spectrum

International Nuclear Information System (INIS)

Song Zhaohui; Wang Baohui; Wang Kuilu; Hei Dongwei; Sun Fengrong; Li Gang

2001-01-01

This paper introduce the application of thermoluminescence dosimeter (TLD) which composed by TLD-3500 Reader and TLD-100M chips on the measurement of hard X-ray pulse energy spectrum. The idea, using Filter Fluorescence Method (FFM) and TLD to measure hard X-ray pulse energy spectrum (from 10 keV to 100 keV), is discussed in details. Considering all the factors of the measuring surroundings, the measurement system of hard X-ray pulse has been devised. The calibration technique of absolute energy response of TLD is established. This method has been applied successfully on the radiation parameters measurement of the huge pulse radiation device -high-power pulser I. Hard X-ray pulse energy spectrum data of the pulser are acquired

Development of Compton X-ray spectrometer for high energy resolution single-shot high-flux hard X-ray spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Kojima, Sadaoki, E-mail: kojima-s@ile.osaka-u.ac.jp, E-mail: sfujioka@ile.osaka-u.ac.jp; Ikenouchi, Takahito; Arikawa, Yasunobu; Sakata, Shohei; Zhang, Zhe; Abe, Yuki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Fujioka, Shinsuke, E-mail: kojima-s@ile.osaka-u.ac.jp, E-mail: sfujioka@ile.osaka-u.ac.jp; Azechi, Hiroshi [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Ozaki, Tetsuo [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Miyamoto, Shuji; Yamaguchi, Masashi; Takemoto, Akinori [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1205 (Japan)

2016-04-15

Hard X-ray spectroscopy is an essential diagnostics used to understand physical processes that take place in high energy density plasmas produced by intense laser-plasma interactions. A bundle of hard X-ray detectors, of which the responses have different energy thresholds, is used as a conventional single-shot spectrometer for high-flux (>10{sup 13} photons/shot) hard X-rays. However, high energy resolution (Δhv/hv < 0.1) is not achievable with a differential energy threshold (DET) X-ray spectrometer because its energy resolution is limited by energy differences between the response thresholds. Experimental demonstration of a Compton X-ray spectrometer has already been performed for obtaining higher energy resolution than that of DET spectrometers. In this paper, we describe design details of the Compton X-ray spectrometer, especially dependence of energy resolution and absolute response on photon-electron converter design and its background reduction scheme, and also its application to the laser-plasma interaction experiment. The developed spectrometer was used for spectroscopy of bremsstrahlung X-rays generated by intense laser-plasma interactions using a 200 μm thickness SiO{sub 2} converter. The X-ray spectrum obtained with the Compton X-ray spectrometer is consistent with that obtained with a DET X-ray spectrometer, furthermore higher certainly of a spectral intensity is obtained with the Compton X-ray spectrometer than that with the DET X-ray spectrometer in the photon energy range above 5 MeV.

Study on magnetic properties of (Nd0.8Ce0.2)2-xFe12Co2B (x = 0-0.6) alloys

Science.gov (United States)

Tan, G. S.; Xu, H.; Yu, L. Y.; Tan, X. H.; Zhang, Q.; Gu, Y.; Hou, X. L.

2017-09-01

In the present work, (Nd0.8Ce0.2)2-xFe12Co2B (x = 0-0.6) permanent alloys are prepared by melt-spinning method. The hard magnetic properties of (Nd0.8Ce0.2)2-xFe12Co2B (x = 0-0.6) alloys annealed at optimum temperatures have been investigated systematically. Depending on the Nd, Ce concentration, the maximum energy product ((BH)max) and remanence (Br) increase gradually with x in the range of 0 ≤ x ≤ 0.4, whereas decrease gradually in the alloys with 0.4 plays a certain role in the magnetization reversal behavior and can improve the microstructure of (Nd0.8Ce0.2)1.6Fe12Co2B alloy.

Hard X-ray-induced optical luminescence via biomolecule-directed metal clusters†

Science.gov (United States)

Pratx, Guillem; Sun, Conroy; Sakamoto, Masanori; Ahmad, Moiz; Volotskova, Olga; Ong, Qunxiang; Teranishi, Toshiharu; Harada, Yoshie

2014-01-01

Here, we demonstrate that biomolecule-directed metal clusters are applicable in the study of hard X-ray excited optical luminescence, promising a new direction in the development of novel X-ray-activated imaging probes. PMID:24463467

Study of flow induce vibration inside 3.5 inch hard disk drives

Directory of Open Access Journals (Sweden)

Wichitpon Seepangmon

2014-06-01

Full Text Available This study focused on flow induced vibration of head stack assembly (HSA in a 3.5 inch hard disk drive with 5 disks and 10 read/write heads. We studied the effects of air flow on gimbal flex and resonance on arm. The comparison of vibrations on slider between the normal model and the experiment has been done for verifying the model. The peaks of frequency in experiment match the normal model at 1,040 1,320 and 1,400 Hz respectively. After that, the RNG K-ε turbulence model was used to determine the turbulent air flow of 7,200 rpm hard disk drive. The comparison between the normal model and the model with spoiler was investigated by using, computational fluid dynamics software (ANSYS and FLUENT. The results shown velocity magnitudes at the arm were decreased by 0.725 - 57.689 % and pressure dropped by 74.028 - 87.222 %. The velocity magnitudes at the gimbal flex were decreased by 5.522 - 14.291 % and pressure dropped by 48.440 - 82.947 %. The peak of vibrations on arm and gimbal flex was occurred at the frequency 1200 Hz. The model with spoiler could reduce vibration at arm by 2.56 - 95.601 % and reduce vibration at gimbal flex by 4.065 - 95.503 %. In the conclusion, the model with a spoiler could decrease the vibration at all surface of the arm and gimbal flex due to the velocity and pressure reduction[1][4].

Short term variation of Cyg X-1 in the hard x-ray region

International Nuclear Information System (INIS)

Doi, Kosei

1978-01-01

Cyg X-1 is a peculiar celestial body considered to be a close binary system of a black hole and a blue super-giant star. It is presently known that the time fluctuation of Cyg X-1 is considerably complex, ranging from seconds to days or months. Of these variation, attention has been paid to the short time variation in relation to the black hole theory. Observations of fluctuations in the order of second have been limited to soft X-ray (20 keV or more) so far, because great technical difficulties are involved due to the low intensity of hard X-ray. The present investigation is based on the fluctuations in the order of second in hard X-ray, and was conducted by employing an unprecedented large area X-ray telescope. The text describes on the brief history of the short time fluctuation, explains the experimental plan, X-ray detecting system, flight of a balloon and the analyses and discussions of fluctuation factor by variation function method, and gives the analysis data and conclusion. The observations resulted in the fact that the fluctuations in the order of second were small at 20 to 30 keV, but become large when energy is higher or lower than this value. The most natural explanation available for this result may be that it is essentially spectrum fluctuation, being inverse correlation in higher and lower energies. Physical meaning of such spectrum fluctuation is considered in connection with precipitating disk model around a black hole. (Wakatsuki, Y.)

Short term variation of Cyg X-1 in the hard x-ray region

Energy Technology Data Exchange (ETDEWEB)

Doi, Kosei [Tokyo Univ. (Japan). Inst. of Space and Aeronautical Science

1978-08-01

Cyg X-1 is a peculiar celestial body considered to be a close binary system of a black hole and a blue super-giant star. It is presently known that the time fluctuation of Cyg X-1 is considerably complex, ranging from seconds to days or months. Of these variation, attention has been paid to the short time variation in relation to the black hole theory. Observations of fluctuations in the order of second have been limited to soft X-ray (20 keV or more) so far, because great technical difficulties are involved due to the low intensity of hard X-ray. The present investigation is based on the fluctuations in the order of second in hard X-ray, and was conducted by employing an unprecedented large area X-ray telescope. The text describes on the brief history of the short time fluctuation, explains the experimental plan, X-ray detecting system, flight of a balloon and the analyses and discussions of fluctuation factor by variation function method, and gives the analysis data and conclusion. The observations resulted in the fact that the fluctuations in the order of second were small at 20 to 30 keV, but become large when energy is higher or lower than this value. The most natural explanation available for this result may be that it is essentially spectrum fluctuation, being inverse correlation in higher and lower energies. Physical meaning of such spectrum fluctuation is considered in connection with precipitating disk model around a black hole.

Hard X-ray balloon observations of compact galactic and extragalactic X-ray sources

International Nuclear Information System (INIS)

Staubert, R.; Kendziorra, E.; Pietsch, W.; Proctor, R.J.; Reppin, C.; Steinle, H.; Truemper, J.; Voges, W.

1981-01-01

A balloon program in hard X-ray astronomy (20-200 keV) is jointly pursued by the Astronomisches Institut der Universitaet Tuebingen (AIT) and the Max Planck-Institut fuer Extraterrestrische Physik in Garching (MPE). Since 1973 nine succussful balloon flights have been performed from Texas and Australia. Here results on Centaurus A and on several galactic binary X-ray sources are summarized. In particular the high energy photon spectrum of Hercules X-1 and the evidence for the cyclotron line feature which was discovered by us in 1976 is reviewed. (orig.)

Hard X-ray Microscopy with sub 30 nm Spatial Resolution

International Nuclear Information System (INIS)

Tang, M.-T.; Song, Y.-F.; Yin, G.-C.; Chen, J.-H.; Chen, Y.-M.; Liang, Keng S.; Chen, F.-R.; Duewer, F.; Yun Wenbing

2007-01-01

A transmission X-ray microscope (TXM) has been installed at the BL01B beamline at National Synchrotron Radiation Research Center in Taiwan. This state-of-the-art TXM operational in a range 8-11 keV provides 2D images and 3D tomography with spatial resolution 60 nm, and with the Zernike-phase contrast mode for imaging light materials such as biological specimens. A spatial resolution of the TXM better than 30 nm, apparently the best result in hard X-ray microscopy, has been achieved by employing the third diffraction order of the objective zone plate. The TXM has been applied in diverse research fields, including analysis of failure mechanisms in microelectronic devices, tomographic structures of naturally grown photonic specimens, and the internal structure of fault zone gouges from an earthquake core. Here we discuss the scope and prospects of the project, and the progress of the TXM in NSRRC

Deducing Electron Properties from Hard X-Ray Observations

Science.gov (United States)

Kontar, E. P.; Brown, J. C.; Emslie, A. G.; Hajdas, W.; Holman, G. D.; Hurford, G. J.; Kasparova, J.; Mallik, P. C. V.; Massone, A. M.; McConnell, M. L.;

Full Multilayer Laue Lens for Focusing Hard X-rays

International Nuclear Information System (INIS)

Liu Chian; Shi, B.; Qian, J.; Conley, R.; Yan, H.; Wieczorek, M.; Macrander, A. T.; Maser, J.; Stephenson, G. B.

2010-01-01

Multilayer Laue Lenses (MLLs) were developed by us using dynamic diffraction effects to efficiently focus hard x-rays to very small spots. Using a partial MLL we were able to focus 19.5-keV hard x-rays to a line focus of 16 nm with an efficiency of 31%. A full MLL is a complete linear MLL structure. It can be fabricated by bonding two partial MLL wafers, or by growing the full structure using magnetron sputtering without bonding. A 40-μm full MLL, with a total of 5166 layers of WSi 2 and Si, has been successfully grown by sputter deposition. The layer thicknesses gradually vary from 4 nm to ∼400 nm and then back to 4 nm. Two coating runs were used to grow the full structure, one for each half. It took over 56 h for each run. A 100-μm nearly-full MLL was constructed by bonding. Each 50-μm half-structure has 1788 WSi 2 and Si layers with 12-nm to ∼32-nm thicknesses and ∼32-μm total thickness, followed by a thick WSi 2 layer of ∼17 μm, and an AuSn layer of ∼1 μm. Both full MLL structures survived dicing and polishing. The primary results demonstrate the feasibility and potential of a full MLL with a doubled numerical aperture and large beam acceptance for hard x-rays.

Hard X-ray sources from miniature plasma focus devices

International Nuclear Information System (INIS)

Raspa, V.; Silva, P.; Moreno, J.; Zambra, M.; Soto, L.

2004-01-01

As first stage of a program to design a repetitive pulsed radiation generator for industrial applications, two miniature plasma foci have been designed and constructed at the Chilean commission of nuclear energy. The devices operate at an energy level of the order of tens of joules (PF-50 J, 160 nF capacitor bank, 20-35 kV, 32-100 J, ∼ 150 ns time to peak current) and hundred of joules (PF-400 J, 880 nF, 20-35 kV, 176-539 J, ∼ 300 ns time to peak current). Hard X-rays are being studied in these devices operating with hydrogen. Images of metallic plates with different thickness were obtained on commercial radiographic film, Agfa Curix ST-G2, in order to characterize the energy of the hard X-ray outside of the discharge chamber of PF-400 J. An effective energy of the order of 90 keV was measured under those conditions. X ray images of different metallic objects also have been obtained. (authors)

Hard X-ray sources from miniature plasma focus devices

Energy Technology Data Exchange (ETDEWEB)

Raspa, V. [Buenos Aires Univ., PLADEMA, CONICET and INFIP (Argentina); Silva, P.; Moreno, J.; Zambra, M.; Soto, L. [Comision Chilena de Energia Nuclear, Santiago (Chile)

2004-07-01

As first stage of a program to design a repetitive pulsed radiation generator for industrial applications, two miniature plasma foci have been designed and constructed at the Chilean commission of nuclear energy. The devices operate at an energy level of the order of tens of joules (PF-50 J, 160 nF capacitor bank, 20-35 kV, 32-100 J, {approx} 150 ns time to peak current) and hundred of joules (PF-400 J, 880 nF, 20-35 kV, 176-539 J, {approx} 300 ns time to peak current). Hard X-rays are being studied in these devices operating with hydrogen. Images of metallic plates with different thickness were obtained on commercial radiographic film, Agfa Curix ST-G2, in order to characterize the energy of the hard X-ray outside of the discharge chamber of PF-400 J. An effective energy of the order of 90 keV was measured under those conditions. X ray images of different metallic objects also have been obtained. (authors)

A comparative approach for the investigation of biological information processing: An examination of the structure and function of computer hard drives and DNA

Science.gov (United States)

2010-01-01

Background The robust storage, updating and utilization of information are necessary for the maintenance and perpetuation of dynamic systems. These systems can exist as constructs of metal-oxide semiconductors and silicon, as in a digital computer, or in the "wetware" of organic compounds, proteins and nucleic acids that make up biological organisms. We propose that there are essential functional properties of centralized information-processing systems; for digital computers these properties reside in the computer's hard drive, and for eukaryotic cells they are manifest in the DNA and associated structures. Methods Presented herein is a descriptive framework that compares DNA and its associated proteins and sub-nuclear structure with the structure and function of the computer hard drive. We identify four essential properties of information for a centralized storage and processing system: (1) orthogonal uniqueness, (2) low level formatting, (3) high level formatting and (4) translation of stored to usable form. The corresponding aspects of the DNA complex and a computer hard drive are categorized using this classification. This is intended to demonstrate a functional equivalence between the components of the two systems, and thus the systems themselves. Results Both the DNA complex and the computer hard drive contain components that fulfill the essential properties of a centralized information storage and processing system. The functional equivalence of these components provides insight into both the design process of engineered systems and the evolved solutions addressing similar system requirements. However, there are points where the comparison breaks down, particularly when there are externally imposed information-organizing structures on the computer hard drive. A specific example of this is the imposition of the File Allocation Table (FAT) during high level formatting of the computer hard drive and the subsequent loading of an operating system (OS). Biological

A comparative approach for the investigation of biological information processing: an examination of the structure and function of computer hard drives and DNA.

Science.gov (United States)

D'Onofrio, David J; An, Gary

2010-01-21

The robust storage, updating and utilization of information are necessary for the maintenance and perpetuation of dynamic systems. These systems can exist as constructs of metal-oxide semiconductors and silicon, as in a digital computer, or in the "wetware" of organic compounds, proteins and nucleic acids that make up biological organisms. We propose that there are essential functional properties of centralized information-processing systems; for digital computers these properties reside in the computer's hard drive, and for eukaryotic cells they are manifest in the DNA and associated structures. Presented herein is a descriptive framework that compares DNA and its associated proteins and sub-nuclear structure with the structure and function of the computer hard drive. We identify four essential properties of information for a centralized storage and processing system: (1) orthogonal uniqueness, (2) low level formatting, (3) high level formatting and (4) translation of stored to usable form. The corresponding aspects of the DNA complex and a computer hard drive are categorized using this classification. This is intended to demonstrate a functional equivalence between the components of the two systems, and thus the systems themselves. Both the DNA complex and the computer hard drive contain components that fulfill the essential properties of a centralized information storage and processing system. The functional equivalence of these components provides insight into both the design process of engineered systems and the evolved solutions addressing similar system requirements. However, there are points where the comparison breaks down, particularly when there are externally imposed information-organizing structures on the computer hard drive. A specific example of this is the imposition of the File Allocation Table (FAT) during high level formatting of the computer hard drive and the subsequent loading of an operating system (OS). Biological systems do not have an

A comparative approach for the investigation of biological information processing: An examination of the structure and function of computer hard drives and DNA

Directory of Open Access Journals (Sweden)

D'Onofrio David J

2010-01-01

Full Text Available Abstract Background The robust storage, updating and utilization of information are necessary for the maintenance and perpetuation of dynamic systems. These systems can exist as constructs of metal-oxide semiconductors and silicon, as in a digital computer, or in the "wetware" of organic compounds, proteins and nucleic acids that make up biological organisms. We propose that there are essential functional properties of centralized information-processing systems; for digital computers these properties reside in the computer's hard drive, and for eukaryotic cells they are manifest in the DNA and associated structures. Methods Presented herein is a descriptive framework that compares DNA and its associated proteins and sub-nuclear structure with the structure and function of the computer hard drive. We identify four essential properties of information for a centralized storage and processing system: (1 orthogonal uniqueness, (2 low level formatting, (3 high level formatting and (4 translation of stored to usable form. The corresponding aspects of the DNA complex and a computer hard drive are categorized using this classification. This is intended to demonstrate a functional equivalence between the components of the two systems, and thus the systems themselves. Results Both the DNA complex and the computer hard drive contain components that fulfill the essential properties of a centralized information storage and processing system. The functional equivalence of these components provides insight into both the design process of engineered systems and the evolved solutions addressing similar system requirements. However, there are points where the comparison breaks down, particularly when there are externally imposed information-organizing structures on the computer hard drive. A specific example of this is the imposition of the File Allocation Table (FAT during high level formatting of the computer hard drive and the subsequent loading of an operating

Hard x ray imaging and the relative contribution of thermal and nonthermal emission in flares

International Nuclear Information System (INIS)

Holman, G.D.

1986-01-01

The question of whether the impulsive 25 to 100 keV x ray emission from solar flares is thermal or nonthermal has been a long-standing controversy. Both thermal and nonthermal (beam) models have been developed and applied to the hard x ray data. It now seems likely that both thermal and nonthermal emission have been observed at hard x ray energies. The Hinotori classification scheme, for example, is an attempt to associate the thermal-nonthermal characteristics of flare hard x ray emission with other flare properties. From a theoretical point of view, it is difficult to generate energetic, nonthermal electrons without dumping an equal or greater amount of energy into plasma heating. On the other hand, any impulsive heating process will invariably generate at least some nonthermal particles. Hence, strictly speaking, although thermal or nonthermal emission may dominate the hard x ray emission in a given energy range for a given flare, there is no such thing as a purely thermal or nonthermal flare mechanism

Thick and large area PIN diodes for hard X-ray astronomy

CERN Document Server

Ota, N; Sugizaki, M; Kaneda, M; Tamura, T; Ozawa, H; Kamae, T; Makishima, K; Takahashi, T; Tashiro, M; Fukazawa, Y; Kataoka, J; Yamaoka, K; Kubo, S; Tanihata, C; Uchiyama, Y; Matsuzaki, K; Iyomoto, N; Kokubun, M; Nakazawa, T; Kubota, A; Mizuno, T; Matsumoto, Y; Isobe, N; Terada, Y; Sugiho, M; Onishi, T; Kubo, H; Ikeda, H; Nomachi, M; Ohsugi, T; Muramatsu, M; Akahori, H

1999-01-01

Thick and large area PIN diodes for the hard X-ray astronomy in the 10-60 keV range are developed. To cover this energy range in a room temperature and in a low background environment, Si PIN junction diodes of 2 mm in thickness with 2.5 cm sup 2 in effective area were developed, and will be used in the bottom of the Phoswich Hard X-ray Detector (HXD), on-board the ASTRO-E satellite. Problems related to a high purity Si and a thick depletion layer during our development and performance of the PIN diodes are presented in detail.

Hard x-ray measurements of the hot-electron rings in EBT-S

International Nuclear Information System (INIS)

Hillis, D.L.

1982-06-01

A thorough understanding of the hot electron rings in ELMO Bumpy Torus-Scale (EBT-S) is essential to the bumpy torus concept of plasma production, since the rings provide bulk plasma stability. The hot electrons are produced via electron cyclotron resonant heating using a 28-GHz cw gyrotron, which has operated up to power levels of 200 kW. The parameters of the energetic electron rings are studied via hard x-ray measurement techniques and with diamagnetic pickup coils. The hard x-ray measurements have used collimated NaI(Tl) detectors to determine the electron temperature T/sub e/ and electron density n/sub e/ for the hot electron annulus. Typical values of T/sub e/ are 400 to 500 keV and of n/sub e/ 2 to 5 x 10 11 cm -3 . The total stored energy of a single energetic electron ring as measured by diamagnetic pickup loops approaches approx. 40 J and is in good agreement with that deduced from hard x-ray measurements. By combining the experimental measurements from hard x-rays and the diamagnetic loops, an estimate can be obtained for the volume of a single hot electron ring. The ring volume is determined to be approx. 2.2 litres, and this volume remains approximately constant over the T-mode operating regime. Finally, the power in the electrons scattered out of the ring is measured indirectly by measuring the x-ray radiation produced when those electrons strike the chamber walls. The variation of this radiation with increasing microwave power levels is found to be consistent with classical scattering estimates

Electronic properties of Nd2−xCexCuO4+δ: A hard X-ray photoemission investigation

International Nuclear Information System (INIS)

Guarino, A.; Panaccione, G.; Offi, F.; Monaco, G.; Fondacaro, A.; Torelli, P.; Fittipaldi, R.; Vecchione, A.; Pace, S.; Nigro, A.

2016-01-01

Highlights: • We grow and characterize Nd 2−x Ce x CuO 4+δ samples as thin film and single crystal. • We study the Cu 2p levels of our samples by hard X-ray photoemission spectroscopy. • We investigate bulk features of the Nd 2−x Ce x CuO 4+δ samples. • Signature of the bulk response is correlated with the crystallinity of the samples. - Abstract: Cu 2p core levels spectra measured by X-ray photoemission spectroscopy of selected as-grown Nd 2−x Ce x CuO 4+δ samples are presented and discussed. The presence of a satellite peak in the 2p core level of Nd 2−x Ce x CuO 4+δ single crystal by hard X-ray photoemission is confirmed in all non-superconducting samples, films and single crystals investigated in this work. The comparison of the spectral features of the different samples suggests that the presence and the intensity of this satellite peak is not related to the electric transport properties, but to the texture characteristics.

Communication: The electronic structure of matter probed with a single femtosecond hard x-ray pulse

Directory of Open Access Journals (Sweden)

J. Szlachetko

2014-03-01

Full Text Available Physical, biological, and chemical transformations are initiated by changes in the electronic configuration of the species involved. These electronic changes occur on the timescales of attoseconds (10−18 s to femtoseconds (10−15 s and drive all subsequent electronic reorganization as the system moves to a new equilibrium or quasi-equilibrium state. The ability to detect the dynamics of these electronic changes is crucial for understanding the potential energy surfaces upon which chemical and biological reactions take place. Here, we report on the determination of the electronic structure of matter using a single self-seeded femtosecond x-ray pulse from the Linac Coherent Light Source hard x-ray free electron laser. By measuring the high energy resolution off-resonant spectrum (HEROS, we were able to obtain information about the electronic density of states with a single femtosecond x-ray pulse. We show that the unoccupied electronic states of the scattering atom may be determined on a shot-to-shot basis and that the measured spectral shape is independent of the large intensity fluctuations of the incoming x-ray beam. Moreover, we demonstrate the chemical sensitivity and single-shot capability and limitations of HEROS, which enables the technique to track the electronic structural dynamics in matter on femtosecond time scales, making it an ideal probe technique for time-resolved X-ray experiments.

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

International Nuclear Information System (INIS)

Shu, Deming; Shvyd’ko, Yuri V.; Stoupin, Stanislav; Kim, Kwang-Je

2016-01-01

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.

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

Energy Technology Data Exchange (ETDEWEB)

Shu, Deming, E-mail: shu@aps.anl.gov; Shvyd’ko, Yuri V.; Stoupin, Stanislav; Kim, Kwang-Je [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, U.S.A (United States)

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.

Resolving the hard X-ray emission of GX 5-1 with INTEGRAL

DEFF Research Database (Denmark)

Paizis, A.; Ebisawa, K.; Tikkanen, T.

2005-01-01

We present the study of one year of INTEGRAL data on the neutron star low mass X-ray binary GX 5-1. Thanks to the excellent angular resolution and sensitivity of INTEGRAL, we are able to obtain a high quality spectrum of GX 5-1 from similar to 5keV to similar to 100 keV, for the first time without...... contamination from the nearby black hole candidate GRS 1758-258 above 20 keV. During our observations, GX 5-1 was mostly found in the horizontal and normal branch of its hardness intensity diagram. A clear hard X-ray emission is observed above similar to 30 keV which exceeds the exponential cut-off spectrum...... expected from lower energies. This spectral flattening may have the same origin of the hard components observed in other Z sources as it shares the property of being characteristic to the horizontal branch. The hard excess is explained by introducing Compton up-scattering of soft photons from the neutron...

An imaging escape gated MPWC for hard X-ray astronomy

International Nuclear Information System (INIS)

Ubertini, P.; Bazzano, A.; Boccaccini, L.; La Padula, C.; Mastropietro, M.; Patriarca, R.; Polcaro, V.F.; Barbareschi, L.; Perotti, F.; Villa, G.; Butler, R.C.; Di Cocco, G.; Spada, G.; Charalambous, P.; Dean, A.J.; Stephen, J.B.

1983-01-01

A scientific forward step in the hard X-ray and soft gamma-ray astronomy will only be possible with the use of a new generation of space borne instruments. Their main characteristics have to be the two-dimensional imaging capability over a large collecting area and the fine spectral resolution in order to discriminate between the weak signal coming from cosmic sources to be detected and the strong background induced by cosmic rays, in the space environment, on the detector. To reach this goal we have developed a new hard X-ray position sensitive proportional counter operating with the escape gate technique in the range 15-150 keV, to be used together with a pseudo-random coded mask in order to obtain sky images. The detector is a high pressure (5 bar) xenon-argon-isobutane filled chamber with a spatial resolution of 30x2 mm and a spectral resolution of 5% at 60 keV on the sensitive area of 3000 cm 2 . (orig.)

Experimental Demonstration of X-Ray Drive Enhancement with Rugby-Shaped Hohlraums

Science.gov (United States)

Philippe, F.; Casner, A.; Caillaud, T.; Landoas, O.; Monteil, M. C.; Liberatore, S.; Park, H. S.; Amendt, P.; Robey, H.; Sorce, C.; Li, C. K.; Seguin, F.; Rosenberg, M.; Petrasso, R.; Glebov, V.; Stoeckl, C.

2010-01-01

Rugby-shaped hohlraums have been suggested as a way to enhance x-ray drive in the indirect drive approach to inertial confinement fusion. This Letter presents an experimental comparison of rugby-shaped and cylinder hohlraums used for D2 and DHe3-filled capsules implosions on the Omega laser facility, demonstrating an increase of x-ray flux by 18% in rugby-shaped hohlraums. The highest yields to date for deuterium gas implosions in indirect drive on Omega (1.5×1010 neutrons) were obtained, allowing for the first time the measurement of a DD burn history. Proton spectra measurements provide additional validation of the higher drive in rugby-shaped hohlraums.

Hard X-ray Optics Technology Development for Astronomy at the Marshall Space Flight Center

Science.gov (United States)

Gubarev, Mikhail; Ramsey, Brian; Kilaru, Kiranmayee

2009-01-01

Grazing-incidence telescopes based on Wolter 1 geometry have delivered impressive advances in astrophysics at soft-x-ray wavelengths, while the hard xray region remains relatively unexplored at fine angular resolution and high sensitivities. The ability to perform ground-breaking science in the hard-x-ray energy range had been the motivation for technology developments aimed at fabricating low-cost, light-weight, high-quality x-ray mirrors. Grazing-incidence x-ray optics for high-energy astrophysical applications is being developed at MSFC using the electroform-nickel replication process.

Searching for Dual AGNs in Galaxy Mergers: Understanding Double-Peaked [O III] and Ultra Hard X-rays as Selection Method

Science.gov (United States)

McGurk, Rosalie C.; Max, Claire E.; Medling, Anne; Shields, Gregory A.

2015-01-01

When galaxies merge, gas accretes onto both central supermassive black holes. Thus, one expects to see close pairs of active galactic nuclei (AGNs), or dual AGNs, in a fraction of galaxy mergers. However, finding them remains a challenge. The presence of double-peaked [O III] or of ultra hard X-rays have been proposed as techniques to select dual AGNs efficiently. We studied a sample of double-peaked narrow [O III] emitting AGNs from SDSS DR7. By obtaining new and archival high spatial resolution images taken with the Keck 2 Laser Guide Star Adaptive Optics system and the near-infrared (IR) camera NIRC2, we showed that 30% of double-peaked [O III] emission line SDSS AGNs have two spatial components within a 3' radius. However, spatially resolved spectroscopy or X-ray observations are needed to confirm these galaxy pairs as systems containing two AGNs. We followed up these spatially-double candidate dual AGNs with integral field spectroscopy from Keck OSIRIS and Gemini GMOS and with long-slit spectroscopy from Keck NIRSPEC and Shane Kast Double Spectrograph. We find double-peaked emitters are caused sometimes by dual AGN and sometimes by outflows or narrow line kinematics. We also performed Chandra X-ray ACIS-S observations on 12 double-peaked candidate dual AGNs. Using our observations and 8 archival observations, we compare the distribution of X-ray photons to our spatially double near-IR images, measure X-ray luminosities and hardness ratios, and estimate column densities. By assessing what fraction of double-peaked emission line SDSS AGNs are true dual AGNs, we can better determine whether double-peaked [O III] is an efficient dual AGN indicator and constrain the statistics of dual AGNs. A second technique to find dual AGN is the detection of ultra hard X-rays by the Swift Burst Alert Telescope. We use CARMA observations to measure and map the CO(1-0) present in nearby ultra-hard X-ray Active Galactic Nuclei (AGNs) merging with either a quiescent companion

STUDYING FAINT ULTRA-HARD X-RAY EMISSION FROM AGN IN GOALS LIRGS WITH SWIFT/BAT

International Nuclear Information System (INIS)

Koss, Michael; Casey, Caitlin M.; Mushotzky, Richard; Veilleux, Sylvain; Baumgartner, Wayne; Tueller, Jack; Markwardt, Craig

2013-01-01

We present the first analysis of the all-sky Swift Burst Alert Telescope (BAT) ultra-hard X-ray (14-195 keV) data for a targeted list of objects. We find that the BAT data can be studied at three-times-fainter limits than in previous blind detection catalogs based on prior knowledge of source positions and using smaller energy ranges for source detection. We determine the active galactic nucleus (AGN) fraction in 134 nearby (z IR /L ☉ > 11.8) detected. The BAT AGN classification shows 97% (37/38) agreement with Chandra and XMM-Newton AGN classification using hardness ratios or detection of an iron Kα line. This confirms our statistical analysis and supports the use of the Swift/BAT all-sky survey to study fainter populations of any category of sources in the ultra-hard X-ray band. BAT AGNs in LIRGs tend to show higher column densities with 40% ± 9% showing 14-195 keV/2-10 keV hardness flux ratios suggestive of high or Compton-thick column densities (log N H > 24 cm –2 ), compared to only 12% ± 5% of non-LIRG BAT AGNs. We also find that using specific energy ranges of the BAT detector can yield additional sources over total band detections with 24% (5/21) of detections in LIRGs at 24-35 keV not detected at 14-195 keV.

Hard X-ray irradiation of cosmic silicate analogs: structural evolution and astrophysical implications

Science.gov (United States)

Gavilan, L.; Jäger, C.; Simionovici, A.; Lemaire, J. L.; Sabri, T.; Foy, E.; Yagoubi, S.; Henning, T.; Salomon, D.; Martinez-Criado, G.

2016-03-01

Context. Protoplanetary disks, interstellar clouds, and active galactic nuclei contain X-ray-dominated regions. X-rays interact with the dust and gas present in such environments. While a few laboratory X-ray irradiation experiments have been performed on ices, X-ray irradiation experiments on bare cosmic dust analogs have been scarce up to now. Aims: Our goal is to study the effects of hard X-rays on cosmic dust analogs via in situ X-ray diffraction. By using a hard X-ray synchrotron nanobeam, we seek to simulate cumulative X-ray exposure on dust grains during their lifetime in these astrophysical environments and provide an upper limit on the effect of hard X-rays on dust grain structure. Methods: We prepared enstatite (MgSiO3) nanograins, which are analogs to cosmic silicates, via the melting-quenching technique. These amorphous grains were then annealed to obtain polycrystalline grains. These were characterized via scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) before irradiation. Powder samples were prepared in X-ray transparent substrates and were irradiated with hard X-rays nanobeams (29.4 keV) provided by beamline ID16B of the European Synchrotron Radiation Facility (Grenoble). X-ray diffraction images were recorded in transmission mode, and the ensuing diffractograms were analyzed as a function of the total X-ray exposure time. Results: We detected the amorphization of polycrystalline silicates embedded in an organic matrix after an accumulated X-ray exposure of 6.4 × 1027 eV cm-2. Pure crystalline silicate grains (without resin) do not exhibit amorphization. None of the amorphous silicate samples (pure and embedded in resin) underwent crystallization. We analyze the evolution of the polycrystalline sample embedded in an organic matrix as a function of X-ray exposure. Conclusions: Loss of diffraction peak intensity, peak broadening, and the disappearance of discrete spots and arcs reveal the amorphization

Reliability evaluation of hard disk drive failures based on counting processes

International Nuclear Information System (INIS)

Ye, Zhi-Sheng; Xie, Min; Tang, Loon-Ching

2013-01-01

Reliability assessment for hard disk drives (HDDs) is important yet difficult for manufacturers. Motivated by the fact that the particle accumulation in the HDDs, which accounts for most HDD catastrophic failures, is contributed from the internal and external sources, a counting process with two arrival sources is proposed to model the particle cumulative process in HDDs. This model successfully explains the collapse of traditional ALT approaches for accelerated life test data. Parameter estimation and hypothesis tests for the model are developed and illustrated with real data from a HDD test. A simulation study is conducted to examine the accuracy of large sample normal approximations that are used to test existence of the internal and external sources.

Micro Hard-X Ray Camera: From Caliste 64 to Caliste 256

International Nuclear Information System (INIS)

Meuris, A.; Limousin, O.; Le Mer, I.; Pinsard, F.; Blondel, C.; Daly, F.; Lugiez, F.; Gevin, O.; Delagnes, E.; Chavassieux, M.; Vassal, M.C.; Bocage, R.; Soufflet, F.

2009-01-01

Caliste project aims at hybridizing 1 cm 2 Cd(Zn)Te detectors with low noise front-end electronics, in a single component standing in a 1 * 1 * 2 cm 3 volume. The micro-camera is a spectroscopic imager for X and gamma rays detection, with time-tagging capability. Hybridization consists in stacking full custom ASICs perpendicular to the detection surface. The first prototype Caliste 64 integrates a detector of 8 * 8 pixels of 1 mm pitch. Fabrication and characterizations of nine cameras units validate the design and the hybridization concept. Spectroscopic tests result in a mean energy resolution of ∼0.7 keV FWHM at 14 keV and ∼0.85 keV FWHM at 60 keV using 1 mm-thick Al Schottky CdTe detectors biased at -400 V and cooled down to 15 degrees C. The new prototype called Caliste 256 integrates 16 * 16 pixels of 580 m pitch in the same volume as Caliste 64. Electrical tests with the first sample fabricated without detector result in a mean equivalent noise charge of 64e - rms (9.6 μs, no leakage current). Caliste devices are 4-side buttable and can be used as elementary detection units of a large hard X-ray focal plane, as for the 64 cm 2 high energy detector of the Simbol-X astronomical space mission. (authors)

Bragg concentrators for hard (> 10keV) x-ray astronomy: Status report

DEFF Research Database (Denmark)

Pareschi, G.; Frontera, F.; Pasqualini, G.

1997-01-01

The use of focusing telescopes in hard X-ray (E > 10 keV) astronomy will provide better flux sensitivity and imaging performances with respect to the direct-viewing detectors, utilized until now. We present recent results obtained from our group regarding the possible use of Bragg-diffraction tec......The use of focusing telescopes in hard X-ray (E > 10 keV) astronomy will provide better flux sensitivity and imaging performances with respect to the direct-viewing detectors, utilized until now. We present recent results obtained from our group regarding the possible use of Bragg...

Electronic properties of Nd{sub 2−x}Ce{sub x}CuO{sub 4+δ}: A hard X-ray photoemission investigation

Energy Technology Data Exchange (ETDEWEB)

Guarino, A., E-mail: guarino@sa.infn.it [CNR-SPIN-Salerno, Fisciano, SA (Italy); Dipartimento di Fisica “E. R. Caianiello” Università di Salerno, Fisciano, SA (Italy); Panaccione, G. [CNR-IOM Laboratorio TASC, AREA Science Park, 34012 Basovizza, TS (Italy); Offi, F. [CNISM and Dipartimento di Scienze, Università Roma Tre, Roma (Italy); Monaco, G. [Dipartimento di Fisica, Università di Trento, Trento (Italy); Fondacaro, A. [European Synchrotron Radiation Facility, BP 220, F-38042 Grenoble (France); Torelli, P. [CNR-IOM Laboratorio TASC, AREA Science Park, 34012 Basovizza, TS (Italy); Fittipaldi, R.; Vecchione, A. [CNR-SPIN-Salerno, Fisciano, SA (Italy); Pace, S.; Nigro, A. [CNR-SPIN-Salerno, Fisciano, SA (Italy); Dipartimento di Fisica “E. R. Caianiello” Università di Salerno, Fisciano, SA (Italy)

2016-10-15

Highlights: • We grow and characterize Nd{sub 2−x}Ce{sub x}CuO{sub 4+δ} samples as thin film and single crystal. • We study the Cu 2p levels of our samples by hard X-ray photoemission spectroscopy. • We investigate bulk features of the Nd{sub 2−x}Ce{sub x}CuO{sub 4+δ} samples. • Signature of the bulk response is correlated with the crystallinity of the samples. - Abstract: Cu 2p core levels spectra measured by X-ray photoemission spectroscopy of selected as-grown Nd{sub 2−x}Ce{sub x}CuO{sub 4+δ} samples are presented and discussed. The presence of a satellite peak in the 2p core level of Nd{sub 2−x}Ce{sub x}CuO{sub 4+δ} single crystal by hard X-ray photoemission is confirmed in all non-superconducting samples, films and single crystals investigated in this work. The comparison of the spectral features of the different samples suggests that the presence and the intensity of this satellite peak is not related to the electric transport properties, but to the texture characteristics.

Development and characterization of a laser-based hard x-ray source

International Nuclear Information System (INIS)

Tillman, C.

1996-11-01

A laser-produced plasma was generated by focusing 100 fs laser pulses, with an energy of 150 mJ, onto metal targets. The laser intensity was expected to reach 10 17 W/cm -2 . Radiation was emitted from the created plasma, with photon energies up to the MeV region. The laser-based X-ray source was optimized, with the purpose of making it a realistic source of hard X-rays (>10 keV). Dedicated equipment was developed for efficient generation and utilization of the hard X-rays. The X-ray source was characterized with respect to its spatial extent and the X-ray yield. Measurements were made of the spectral distribution, by the use of single-photon-counting detectors in different geometries, crystal spectrometers and dose measurements in combination with absorption filters. Ablation of the target material in the laser produced plasma was investigated. Imaging applications have been demonstrated, including ultrafast (picosecond) X-ray imaging, magnification imaging of up to x80, differential imaging in the spectral domain, and imaging of various biological and technical objects. The biological response of ultra-intense X-ray pulses was assessed in cell-culture exposures. The results indicate that the biological response from ultra-intense X-ray exposures is similar to the response with conventional X-ray tubes. 82 refs., 14 figs

Development and characterization of a laser-based hard x-ray source

Energy Technology Data Exchange (ETDEWEB)

Tillman, C.

1996-11-01

A laser-produced plasma was generated by focusing 100 fs laser pulses, with an energy of 150 mJ, onto metal targets. The laser intensity was expected to reach 10{sup 17} W/cm{sup -2}. Radiation was emitted from the created plasma, with photon energies up to the MeV region. The laser-based X-ray source was optimized, with the purpose of making it a realistic source of hard X-rays (>10 keV). Dedicated equipment was developed for efficient generation and utilization of the hard X-rays. The X-ray source was characterized with respect to its spatial extent and the X-ray yield. Measurements were made of the spectral distribution, by the use of single-photon-counting detectors in different geometries, crystal spectrometers and dose measurements in combination with absorption filters. Ablation of the target material in the laser produced plasma was investigated. Imaging applications have been demonstrated, including ultrafast (picosecond) X-ray imaging, magnification imaging of up to x80, differential imaging in the spectral domain, and imaging of various biological and technical objects. The biological response of ultra-intense X-ray pulses was assessed in cell-culture exposures. The results indicate that the biological response from ultra-intense X-ray exposures is similar to the response with conventional X-ray tubes. 82 refs., 14 figs.

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

Science.gov (United States)

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.

Effect of Mo concentration and aging time on the magnetic and mechanical hardness of Fe-xMo-5Ni-0.05C alloys (x = 5, 8, 11 and 15 wt. (%

Directory of Open Access Journals (Sweden)

Mauro Carlos Lopes Souza

2009-01-01

Full Text Available Changes to the microestructure during thermal aging treatment at 610 ºC in Fe-xMo-5Ni-0.05C alloys were studied for different aging times with different Mo concentrations. The heat treatment at 610 ºC induces carbide precipitation into the metallic matrix near Fe2Mo phase. The X-ray diffraction studies revealed a more intense precipitation of α-FeMo, Fe3Mo, R(Fe63Mo37 phases and MoC, Fe2MoC carbides for the alloys containing 15 and 11% Mo, respectively. This work shows that hardness and coercive force changes are function of the molybdenum content and aging time variation. Vickers hardness and coercive force both increase with the increase of molybdenum content and reach maximum values at 4 and 1h of aging, respectively.

Magnified hard x-ray microtomography: toward tomography with submicron resolution

Science.gov (United States)

Schroer, Christian G.; Benner, Boris; Guenzler, Til F.; Kuhlmann, Marion; Lengeler, Bruno; Rau, Christoph; Weitkamp, Timm; Snigirev, Anatoly A.; Snigireva, Irina

2002-01-01

Parabolic compound refractive lenses (PCRLs) are high quality imaging optics for hard x-rays that can be used as an objective lens in a new type of hard x-ray full field microscope. Using an aluminium PCRL, this new type of microscope has been shown to have a resolution of 350 nm. Further improvement of the resolution down to 50 nm can be expected using beryllium as a lens material. The large depth of field (several mm) of the microscope results in sharp projection images for samples that fit into the field of view of about 300 micrometers. This allows to combine magnified imaging with tomographic techniques. First results of magnified microtomography are shown. Contrast formation in the microscope and the consequences for tomographic reconstruction are discussed. An outlook on further developments is given.

MODELING THE THERMAL DIFFUSE SOFT AND HARD X-RAY EMISSION IN M17

International Nuclear Information System (INIS)

Velázquez, P. F.; Rodríguez-González, A.; Esquivel, A.; Rosado, M.; Reyes-Iturbide, J.

2013-01-01

We present numerical models of very young wind driven superbubbles. The parameters chosen for the simulations correspond to the particular case of the M17 nebula, but are appropriate for any young superbubble in which the wind sources have not completely dispersed their parental cloud. From the simulations, we computed the diffuse emission in the soft ([0.5-1.5] keV) and hard ([1.5-5] keV) X-ray bands. The total luminosity in our simulations agrees with the observations of Hyodo et al., about two orders of magnitude below the prediction of the standard model of Weaver et al.. The difference with respect to the standard (adiabatic) model is the inclusion of radiative cooling, which is still important in such young bubbles. We show that for this type of object the diffuse hard X-ray luminosity is significant compared to that of soft X-rays, contributing as much as 10% of the total luminosity, in contrast with more evolved bubbles where the hard X-ray emission is indeed negligible, being at least four orders of magnitude lower than the soft X-ray emission.

RENEWED ACTIVITY FROM THE X-RAY TRANSIENT SAXJ 1810.8-2609 WITH INTEGRAL

DEFF Research Database (Denmark)

Fiocchi, M.; Natalucci, L.; Chenevez, Jérôme

2009-01-01

(36) erg s(-1) in the 20-100 keV energy range. This low outburst luminosity and the long-term time-average accretion rate of similar to 5 x 10(-12) M-circle dot yr(-1) suggest that SAX J1810.8-2609 is a faint soft X-ray transient. During the flux increase, spectra are consistent with a thermal...... Comptonization model with a temperature plasma of kT(e) similar to 23-30 keV and an optical depth of tau similar to 1.2-1.5, independent of the luminosity of the system. This is a typical low hard spectral state for which the X-ray emission is attributed to the upscattering of soft seed photons by a hot......, optically thin electron plasma. During the decay, spectra have a different shape, the high energy tail being compatible with a single power law. This confirm similar behavior observed by BeppoSAX during the previous outburst, with the absence of visible cutoff in the hard X-ray spectrum. INTEGRAL...

Relationship between type III-V radio and hard X-ray bursts

International Nuclear Information System (INIS)

Stewart, R.T.

1978-01-01

Type III-V radio bursts are found to be closely associated with impulsive hard X-ray bursts. Probably 0.1% to 1% of the fast electrons in the X-ray source region escape to heights >0.1 solar radii in the corona and excite the type III-V burst. (Auth.)

Achieving few-femtosecond time-sorting at hard X-ray free-electron lasers

Science.gov (United States)

Harmand, M.; Coffee, R.; Bionta, M. R.; Chollet, M.; French, D.; Zhu, D.; Fritz, D. M.; Lemke, H. T.; Medvedev, N.; Ziaja, B.; Toleikis, S.; Cammarata, M.

2013-03-01

Recently, few-femtosecond pulses have become available at hard X-ray free-electron lasers. Coupled with the available sub-10 fs optical pulses, investigations into few-femtosecond dynamics are not far off. However, achieving sufficient synchronization between optical lasers and X-ray pulses continues to be challenging. We report a `measure-and-sort' approach, which achieves sub-10 fs root-mean-squared (r.m.s.) error measurement at hard X-ray FELs, far beyond the 100-200 fs r.m.s. jitter limitations. This timing diagnostic, now routinely available at the Linac Coherent Light Source (LCLS), is based on ultrafast free-carrier generation in optically transparent materials. Correlation between two independent measurements enables unambiguous demonstration of ~6 fs r.m.s. error in reporting the optical/X-ray delay, with single shot error suggesting the possibility of reaching few-femtosecond resolution.

Evaluation of radiation tolerance of FETs used for Astro-E2 hard X-ray detector (HXD-II)

International Nuclear Information System (INIS)

Itoh, Takeshi; Niko, Hisako; Kokubun, Motohide; Makishima, Kazuo; Kawaharada, Madoka; Takahashi, Isao; Miyasaka, Hiromasa

2005-01-01

We evaluated the radiation tolerance of three types of metal-can MOS Field Effect Transistors (FETs). They are candidates for flight electronics of the Hard X-ray Detector (HXD-II) experiment which is onboard the cosmic X-ray satellite Astro-E2 scheduled for launch in 2005. We irradiated FETs with a Co60γ-ray source under several different experimental conditions, and measured changes in their I-V characteristic curves. After a 10krad irradiation during which the gate voltage is set at 0V, all types showed a decrease in the switching voltage by ∼0.2-0.4V. In addition, the gate conductance increased under some irradiation conditions. These experimental results may be explained in terms of trapped charges and boundary levels in the oxide layer beneath the gate electrode. We have confirmed that at least two types of FETs can be used in our satellite-borne experiment, one as relay-driving FETs and the other in TTL-ECL conversion circuits

Work Hard / Play Hard

OpenAIRE

Burrows, J.; Johnson, V.; Henckel, D.

2016-01-01

Work Hard / Play Hard was a participatory performance/workshop or CPD experience hosted by interdisciplinary arts atelier WeAreCodeX, in association with AntiUniversity.org. As a socially/economically engaged arts practice, Work Hard / Play Hard challenged employees/players to get playful, or go to work. 'The game changes you, you never change the game'. Employee PLAYER A 'The faster the better.' Employer PLAYER B

SENSITIVITY OF STACKED IMAGING DETECTORS TO HARD X-RAY POLARIZATION

Energy Technology Data Exchange (ETDEWEB)

Muleri, Fabio; Campana, Riccardo, E-mail: fabio.muleri@iaps.inaf.it [INAF-IAPS, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy)

2012-06-01

The development of multi-layer optics which allow to focus photons up to 100 keV and more promises an enormous jump in sensitivity in the hard X-ray energy band. This technology is already planned to be exploited by future missions dedicated to spectroscopy and imaging at energies >10 keV, e.g., Astro-H and NuSTAR. Nevertheless, our understanding of the hard X-ray sky would greatly benefit from carrying out contemporaneous polarimetric measurements, because the study of hard spectral tails and of polarized emission are often two complementary diagnostics of the same non-thermal and acceleration processes. At energies above a few tens of keV, the preferred technique to detect polarization involves the determination of photon directions after a Compton scattering. Many authors have asserted that stacked detectors with imaging capabilities can be exploited for this purpose. If it is possible to discriminate those events which initially interact in the first detector by Compton scattering and are subsequently absorbed by the second layer, then the direction of scattering is singled out from the hit pixels in the two detectors. In this paper, we give the first detailed discussion of the sensitivity of such a generic design to the X-ray polarization. The efficiency and the modulation factor are calculated analytically from the geometry of the instruments and then compared with the performance as derived by means of Geant4 Monte Carlo simulations.

Recent advances in synchrotron-based hard x-ray phase contrast imaging

International Nuclear Information System (INIS)

Liu, Y; Nelson, J; Andrews, J C; Pianetta, P; Holzner, C

2013-01-01

Ever since the first demonstration of phase contrast imaging (PCI) in the 1930s by Frits Zernike, people have realized the significant advantage of phase contrast over conventional absorption-based imaging in terms of sensitivity to ‘transparent’ features within specimens. Thus, x-ray phase contrast imaging (XPCI) holds great potential in studies of soft biological tissues, typically containing low Z elements such as C, H, O and N. Particularly when synchrotron hard x-rays are employed, the favourable brightness, energy tunability, monochromatic characteristics and penetration depth have dramatically enhanced the quality and variety of XPCI methods, which permit detection of the phase shift associated with 3D geometry of relatively large samples in a non-destructive manner. In this paper, we review recent advances in several synchrotron-based hard x-ray XPCI methods. Challenges and key factors in methodological development are discussed, and biological and medical applications are presented. (paper)

Recent advances in synchrotron-based hard x-ray phase contrast imaging

Science.gov (United States)

Liu, Y.; Nelson, J.; Holzner, C.; Andrews, J. C.; Pianetta, P.

2013-12-01

Ever since the first demonstration of phase contrast imaging (PCI) in the 1930s by Frits Zernike, people have realized the significant advantage of phase contrast over conventional absorption-based imaging in terms of sensitivity to ‘transparent’ features within specimens. Thus, x-ray phase contrast imaging (XPCI) holds great potential in studies of soft biological tissues, typically containing low Z elements such as C, H, O and N. Particularly when synchrotron hard x-rays are employed, the favourable brightness, energy tunability, monochromatic characteristics and penetration depth have dramatically enhanced the quality and variety of XPCI methods, which permit detection of the phase shift associated with 3D geometry of relatively large samples in a non-destructive manner. In this paper, we review recent advances in several synchrotron-based hard x-ray XPCI methods. Challenges and key factors in methodological development are discussed, and biological and medical applications are presented.

CO-ANALYSIS OF SOLAR MICROWAVE AND HARD X-RAY SPECTRAL EVOLUTIONS. I. IN TWO FREQUENCY OR ENERGY RANGES

International Nuclear Information System (INIS)

Song Qiwu; Huang Guangli; Nakajima, Hiroshi

2011-01-01

Solar microwave and hard X-ray spectral evolutions are co-analyzed in the 2000 June 10 and 2002 April 10 flares, and are simultaneously observed by the Owens-Valley Solar Array in the microwave band and by Yohkoh/Hard X-ray Telescope or RHESSI in the hard X-ray band, with multiple subpeaks in their light curves. The microwave and hard X-ray spectra are fitted by a power law in two frequency ranges of the optical thin part and two photon energy ranges, respectively. Similar to an earlier event in Shao and Huang, the well-known soft-hard-soft pattern of the lower energy range changed to the hard-soft-hard (HSH) pattern of the higher energy range during the spectral evolution of each subpeak in both hard X-ray flares. This energy dependence is actually supported by a positive correlation between the overall light curves and spectral evolution in the lower energy range, while it becomes an anti-correlation in the higher energy range. Regarding microwave data, the HSH pattern appears in the spectral evolution of each subpeak in the lower frequency range, which is somewhat similar to Huang and Nakajima. However, it returns back to the well-known pattern of soft-hard-harder for the overall spectral evolution in the higher frequency range of both events. This frequency dependence is confirmed by an anti-correlation between the overall light curves and spectral evolution in the lower frequency range, but it becomes a positive correlation in the higher frequency range. The possible mechanisms are discussed, respectively, for reasons why hard X-ray and microwave spectral evolutions have different patterns in different energy and frequency intervals.

Analysis of the development and performance of hard disks

OpenAIRE

Novak, Davorin

2010-01-01

With the emergence of new technologies in the field of hard drives we can witness a significant increase of surface density and transfer rate of interfaces which, as a result, enables greater performance and reliability of hard disks. The reason for this are increasing needs for higher capacities and data transfer rate to or from the hard disk. This thesis presents the structure of hard drives, features, performance and reliability of hard drives and alternative data storage technologies. Par...

Hard X-ray brightening of Ginga 1843+009 seen by INTEGRAL

DEFF Research Database (Denmark)

Leyder, J.-C.; Chenevez, Jérôme; Fiocchi, M.T.

2005-01-01

The transient X-ray pulsar, Ginga 1843+009, appears to be undergoing a hard X-ray outburst brighter than the one reported in May 2003 (ATEL #159). The source has been observed during ISWT observations of the Scutum Arm region with INTEGRAL and was first detected when the source was in the field o...

Spectral and temporal properties of the X-ray pulsar SMC X-1 at hard X-rays

Science.gov (United States)

Kunz, M.; Gruber, D. E.; Kendziorra, E .; Kretschmar, P.; Maisack, M.; Mony, B.; Staubert, R.; Doebereiner, S.; Englhauser, J.; Pietsch, W.

1993-01-01

The binary X-ray pulsar SMC X- 1 has been observed at hard X-rays with the High Energy X-Ray Experiment (HEXE) on nine occasions between Nov. 1987 and March 1989. A thin thermal bremsstrahlung fit to the phase averaged spectrum yields a plasma temperature (14.4 +/- 1.3) keV and a luminosity above (1.1 +/- 0.1) x 10 exp 38 erg/s in the 20-80 keV band. Pulse period values have been established for three observations, confirming the remarkably stable spin-up trend of SMC X-1. In one of the three observations the pulse profile was seen to deviate from a dominant double pulsation, while at the same time the pulsed fraction was unusually large. For one observation we determined for the first time the pulsed fraction in narrow energy bands. It increases with photon energy from about 20 percent up to over 60 percent in the energy range from 20 to 80 keV.

Development of Small-Pixel CZT Detectors for Future High-Resolution Hard X-ray Missions

Science.gov (United States)

Beilicke, Matthias

Owing to recent breakthroughs in grazing incidence mirror technology, next-generation hard X-ray telescopes will achieve angular resolutions of between 5 and 10 arc seconds - about an order of magnitude better than that of the NuSTAR hard X-ray telescope. As a consequence, the next generation of hard X-ray telescopes will require pixelated hard X- ray detectors with pixels on a grid with a lattice constant of between 120 and 240 um. Additional detector requirements include a low energy threshold of less than 5 keV and an energy resolution of less than 1 keV. The science drivers for a high angular-resolution hard X-ray mission include studies and measurements of black hole spins, the cosmic evolution of super-massive black holes, AGN feedback, and the behavior of matter at very high densities. We propose a R&D research program to develop, optimize and study the performance of 100-200 um pixel pitch CdTe and Cadmium Zinc Telluride (CZT) detectors of 1-2 mm thickness. Our program aims at a comparison of the performance achieved with CdTe and CZT detectors, and the optimization of the pixel, steering grid, and guard ring anode patterns. Although these studies will use existing ASICs (Application Specific Integrated Circuits), our program also includes modest funds for the development of an ultra-low noise ASIC with a 2-D grid of readout pads that can be directly bonded to the 100-200 um pixel pitch CdTe and CZT detectors. The team includes the Washington University group (Prof. M. Beilicke and Co-I Prof. H.S.W. Krawczynski et al.), and co-investigator G. De Geronimo at Brookhaven National Laboratory (BNL). The Washington University group has a 10 year track record of innovative CZT detector R&D sponsored by the NASA Astronomy and Physics Research and Analysis (APRA) program. The accomplishments to date include the development of CZT detectors with pixel pitches between 350 um and 2.5 mm for the ProtoExist, EXIST, and X-Calibur hard X-ray missions with some of the best

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

DEFF Research Database (Denmark)

Hong, JaeSub; Mori, Kaya; Hailey, Charles J.

2016-01-01

persistent luminous X-ray binaries (XBs) and the likely run-away pulsar called the Cannonball. New source-detection significance maps reveal a cluster of hard (>10 keV) X-ray sources near the Sgr. A diffuse complex with no clear soft X-ray counterparts. The severe extinction observed in the Chandra spectra...

Hard X-ray full field microscopy and magnifying microtomography using compound refractive lenses

CERN Document Server

Schrör, C; Benner, B; Kuhlmann, M; Tümmler, J; Lengeler, B; Rau, C; Weitkamp, T; Snigirev, A; Snigireva, I

2001-01-01

For hard X-rays, parabolic compound refractive lenses (PCRLs) are genuine imaging devices like glass lenses for visible light. Based on these new lenses, a hard X-ray full field microscope has been constructed that is ideally suited to image the interior of opaque samples with a minimum of sample preparation. As a result of a large depth of field, CRL micrographs are sharp projection images of most samples. To obtain 3D information about a sample, tomographic techniques are combined with magnified imaging.

Hard X-ray full field microscopy and magnifying microtomography using compound refractive lenses

Science.gov (United States)

Schroer, Christian G.; Günzler, Til Florian; Benner, Boris; Kuhlmann, Marion; Tümmler, Johannes; Lengeler, Bruno; Rau, Christoph; Weitkamp, Timm; Snigirev, Anatoly; Snigireva, Irina

2001-07-01

For hard X-rays, parabolic compound refractive lenses (PCRLs) are genuine imaging devices like glass lenses for visible light. Based on these new lenses, a hard X-ray full field microscope has been constructed that is ideally suited to image the interior of opaque samples with a minimum of sample preparation. As a result of a large depth of field, CRL micrographs are sharp projection images of most samples. To obtain 3D information about a sample, tomographic techniques are combined with magnified imaging.

Hard X-ray full field microscopy and magnifying microtomography using compound refractive lenses

International Nuclear Information System (INIS)

Schroer, Christian G.; Guenzler, Til Florian; Benner, Boris; Kuhlmann, Marion; Tuemmler, Johannes; Lengeler, Bruno; Rau, Christoph; Weitkamp, Timm; Snigirev, Anatoly; Snigireva, Irina

2001-01-01

For hard X-rays, parabolic compound refractive lenses (PCRLs) are genuine imaging devices like glass lenses for visible light. Based on these new lenses, a hard X-ray full field microscope has been constructed that is ideally suited to image the interior of opaque samples with a minimum of sample preparation. As a result of a large depth of field, CRL micrographs are sharp projection images of most samples. To obtain 3D information about a sample, tomographic techniques are combined with magnified imaging

Confinement of hot, hard x-ray producing electrons in solar flares

International Nuclear Information System (INIS)

Smith, D.F.; Lilliequist, C.G.

1979-01-01

Possible thermal models for solar, hard X-ray emission, consisting of small volumes in which the electrons are rapidly heated to 4 x 10 8 K, are examined to determine under what conditions such models can be more efficient than nonthermal models. The primary energy-loss mechanism in these models is source expansion due to heat conduction which deviates from its classical value by mechanisms which are reviewed and systematized. One such mechanism is saturation of the heat flux at its maximum possible value, corresponding to direct convection by electrons. Another mechanism is anomalous limitation of the heat flux due to instability of the return current which must compensate the electron current carrying the heat. A simple, one-dimensional model in which a section of the flux tube of constant density is heated to 4 x 10 8 K is analyzed. A conduction front, determined by the above collisionless process, moves along the flux tube at the head of the expanding source. A more realistic, one-dimensional, one-fluid, two-temperature model with a spatially and temporally varying energy source which delivers energy to the electrons at a finite rate is formulated and solved numerically. This results in some ion heating and mass motions which, by themselves, represent only a small energy loss. However, because of changes in the anomalous limitation of the heat flux with higher ion temperature, the expansion losses increase considerably

X-ray magnetic circular dichroism and hard X-ray photoelectron spectroscopy of tetragonal Mn72Ge28 epitaxial thin film

Science.gov (United States)

Kim, Jinhyeok; Mizuguchi, Masaki; Inami, Nobuhito; Ueno, Tetsuro; Ueda, Shigenori; Takanashi, Koki

2018-04-01

An epitaxially grown Mn72Ge28 film with a tetragonal crystal structure was fabricated. It was clarified that the film had a perpendicular magnetization and a high perpendicular magnetic anisotropy energy of 14.3 Merg/cm3. The electronic structure was investigated by X-ray magnetic circular dichroism and hard X-ray photoelectron spectroscopy. The obtained X-ray magnetic circular dichroism spectrum revealed that the Mn orbital magnetic moment governed the magnetocrystalline anisotropy of the Mn72Ge28 film. A doublet structure was observed for the Mn 2p3/2 peak of hard X-ray photoelectron spectrum, indicating the spin exchange interaction between the 2p core-hole and 3d valence electrons.

Development and application of cryogenic radiometry with hard X-rays

International Nuclear Information System (INIS)

Gerlach, Martin

2008-01-01

To establish cryogenic radiometry with hard X-ray radiation for photon energies of up to 60 keV, a novel type of cavity absorber had to be developed for the cryogenic radiometer SYRES I, which is deployed by the Physikalisch-Technische Bundesanstalt (PTB) as primary standard detector at the electron storage ring BESSY II. This new type of cavity absorber allows for the complete absorption of hard X-ray radiation in combination with an appropriate sensitivity and an adequate time constant for the measurement of synchrotron radiation at BESSY II. As the process of fabrication of different types of absorbers is very time-consuming, the interaction of hard X-ray radiation with different absorber materials and geometries was studied intensively by using the Monte Carlo simulation code Geant4. The accuracy of the simulations was verified comparing them to scattering experiments performed at a wavelength shifter beamline at BESSY II with a calibrated energy dispersive detector. It was shown that Geant4 describes the photo-effect, including fluorescence as well as Compton- and Rayleigh scattering, with high accuracy. The simulations and experiments resulted in a cavity absorber with a gold base 550 μm in thickness and a cylindrical shell made of copper 90 μm in thickness to reduce losses caused by fluorescence and scattered radiation. Monochromatized synchrotron radiation of high spectral purity was then used to calibrate semiconductor photodiodes, which can be used as compact and inexpensive secondary standard detectors, against a cryogenic radiometer, covering the entire photon energy range of three beamlines from 50 eV to 60 keV with relative uncertainties of less than 0.5 %. Furthermore the spatial homogeneity of the spectral responsivity, the transmittance and the linearity of the photodiodes was investigated. Through a direct comparison of the free-air ionization chamber PK100, a primary detector standard of PTB used in dosimetry, and the cryogenic radiometer SYRES

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

Czech Academy of Sciences Publication Activity Database

Oberta, Peter; Mokso, R.

2013-01-01

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

New hard X-ray sources at 38/sup 0/ declination

Energy Technology Data Exchange (ETDEWEB)

Ubertini, P.; Bazzano, A.; La Padula, C.; Polcaro, V.F. (Consiglio Nazionale delle Ricerche, Frascati (Italy). Lab. di Astrofisica Spaziale)

1981-01-01

We report the detection of three new hard X-rays sources emitting in the range 15-150 KeV. Their observation was carried out by means of a balloon borne payload, consisting of two large area high spectral resolution Multiwire Spectroscopic Proportional Counters.

Self-standing quasi-mosaic crystals for focusing hard X-rays

International Nuclear Information System (INIS)

Camattari, Riccardo; Guidi, Vincenzo; Bellucci, Valerio; Neri, Ilaria; Frontera, Filippo; Jentschel, Michael

2013-01-01

A quasi mosaic bent crystal for high-resolution diffraction of X and γ rays has been realized. A net curvature was imprinted to the crystal thanks to a series of superficial grooves to keep the curvature without external devices. The crystal highlights very high diffraction efficiency due to quasi mosaic curvature. Quasi mosaic crystals of this kind are proposed for the realization of a high-resolution focusing Laue lens for hard X-rays.

TRACING THE REVERBERATION LAG IN THE HARD STATE OF BLACK HOLE X-RAY BINARIES

International Nuclear Information System (INIS)

De Marco, B.; Ponti, G.; Nandra, K.; Muñoz-Darias, T.

2015-01-01

We report results obtained from a systematic analysis of X-ray lags in a sample of black hole X-ray binaries, with the aim of assessing the presence of reverberation lags and studying their evolution during outburst. We used XMM-Newton and simultaneous Rossi X-ray Timing Explorer (RXTE) observations to obtain broadband energy coverage of both the disk and the hard X-ray Comptonization components. In most cases the detection of reverberation lags is hampered by low levels of variability-power signal-to-noise ratio (typically when the source is in a soft state) and/or short exposure times. The most detailed study was possible for GX 339-4 in the hard state, which allowed us to characterize the evolution of X-ray lags as a function of luminosity in a single source. Over all the sampled frequencies (∼0.05–9 Hz), we observe the hard lags intrinsic to the power-law component, already well known from previous RXTE studies. The XMM-Newton soft X-ray response allows us to detail the disk variability. At low frequencies (long timescales) the disk component always leads the power-law component. On the other hand, a soft reverberation lag (ascribable to thermal reprocessing) is always detected at high frequencies (short timescales). The intrinsic amplitude of the reverberation lag decreases as the source luminosity and the disk fraction increase. This suggests that the distance between the X-ray source and the region of the optically thick disk where reprocessing occurs gradually decreases as GX 339-4 rises in luminosity through the hard state, possibly as a consequence of reduced disk truncation

Hard-x-ray phase-difference microscopy with a low-brilliance laboratory x-ray source

International Nuclear Information System (INIS)

Kuwabara, Hiroaki; Yashiro, Wataru; Harasse, Sebastien; Momose, Atsushi; Mizutani, Haruo

2011-01-01

We have developed a hard-X-ray phase-imaging microscopy method using a low-brilliance X-ray source. The microscope consists of a sample, a Fresnel zone plate, a transmission grating, and a source grating creating an array of mutually incoherent X-ray sources. The microscope generates an image exhibiting twin features of the sample with opposite signs separated by a distance, which is processed to generate a phase image. The method is quantitative even for non-weak-phase objects that are difficult to be quantitatively examined by the widely used Zernike phase-contrast microscopy, and it has potentially broad applications in the material and biological science fields. (author)

Blade-type X-ray beam position monitors for SPring-8 undulator beamlines

CERN Document Server

Aoyagi, H; Kitamura, H

2001-01-01

The X-ray beam position monitors had been designed and installed for SPring-8 insertion device beamlines. These monitors are being utilized for photon beam diagnostics. The beam from the standard undulator in SPring-8 has the total power of 11 kW and the power density of 470 kW/mrad sup 2 , typically. Each monitor has four CVD diamond blades coated with metal for detector heads. We have already introduced three styles of monitors to match various insertion devices in SPring-8. A standard style, or a fixed-blade style, is used mainly for a standard in-vacuum undulator beamlines. A horizontal-blade-drive style and a four-blade-drive style are used for beamlines of a wiggler and a twin helical undulator that have wide power distributions, and for figure-8 undulators that have asymmetric power distributions, respectively. This report describes the design and the structure of these monitors and the beam-tests for the photon beam diagnostics in detail.

Hard X-ray dosimetry of a plasma focus suitable for industrial radiography

Science.gov (United States)

Knoblauch, P.; Raspa, V.; Di Lorenzo, F.; Clausse, A.; Moreno, C.

2018-04-01

Dosimetric measurements of the hard X-ray emission by a small-chamber 4.7 kJ Mather-type plasma focus device capable of producing neat radiographs of metallic objects, were carried out with a set of thermoluminescent detectors TLD 700 (LiF:Mg,Ti). Measurements of the hard X-ray dose dependence with the angular position relative to the electrodes axis, are presented. The source-detector distance was changed in the range from 50 to 100 cm, and the angular positions were explored between ± 70°, relative to the symmetry axis of the electrodes. On-axis measurements show that the X-ray intensity is uniform within a half aperture angle of 6°, in which the source delivers an average dose of (1.5 ± 0.1) mGy/sr per shot. Monte Carlo calculations suggest that the energy of the electron beam responsible for the X-ray emission ranges 100-600 keV.

Time Delays Between Decimetric Type-Iii Bursts and Associated Hard X-Rays

Science.gov (United States)

Sawant, H. S.; Lattari, C. J. B.; Benz, A. O.; Dennis, B. R.

1990-11-01

RESUMEN. En julio de 1987, se efectuaron radio observaciones en 1.6 CHz usando la antena de 13.7-m de Itapetinga con un tiempo de resoluci5n de 3 ms. Las observaciones en rayos-X fueron obtenidas del HXRBS en SMM. Comparaciones de observaciones de 1.6 CHz con espectro dinamico en el intervalo de (1000 - 100) MHz y rayos-X duros muestran los siguientes resultados: I) en 12 casos, identificamos la continuaci6n de brotes de tipo Ill-RD hasta 1.6 GHz. ii) Por primera vez, hemos identificadopicos de rayos-X demorados en comparaci6n con el brote decimetrico tipolll-RD. Estos retardos son mas largos - 1 5 - que lo esperado ( " 100 ms) y han sido interpretados suponiendo que la emisi6n decimetrica es la 2a. ar- m6nica y esta causada por el borde delantero del excitador, mientras que los picos de los rayos-X han sido atribuidos a la entrada completa del excitador dentro de la regi6n que produce los rayos-X. ABSTRACT. In July, 1985 radio observations were made at 1.6 GHz using 13.7 m Itapetinga antenna with time resolution of 3 ms. The hard X-ray observations were obtained from HXRBS on SMM. Comparison of 1.6 GHz observations with dynamic spectra in the frequency range of (1000 - 100) MHz and hard X-rays shows the following results: i) In 12 cases, we identify continuation of type Ill-RD bursts up to 1.6 GHz suggesting presence of type Ill-RD bursts at 1.6 GHz. ii) For the first time, we have idetified hard X-ray peaks delayed in comparison to decimetric type Ill-RD bursts. These dalays are longer - 1 5 - than expected ( 100 ms) and have been interpreted assuming that the decimetric emission is at 2 nd harmonic and caused by the leading edge of the exciter, whereas peaks of X-rays have been attributed to entire entry of the exciter into the X-ray producing region. Keq : SUN BURSTS - SUN-

Analysis of the 1980 November 18 limb flare observed by the hard X-ray imaging spectrometer (HXIS)

NARCIS (Netherlands)

Hoyng, P.; Haug, E.; Elwert, G.

1984-01-01

X-ray images of the 18 November 1980 limb flare taken by the HXIS instrument aboard SMM were analysed. The hard X-rays originated from three spots on the SW limb of the solar disk with different altitudes and time evolution. The locations of the brightest spots in hard and soft X-rays are compared

Spatial and temporal structures of impulsive bursts from solar flares observed in UV and hard X-rays

Science.gov (United States)

Cheng, C.-C.; Tandberg-Hanssen, E.; Bruner, E. C.; Orwig, L.; Frost, K. J.; Kenny, P. J.; Woodgate, B. E.; Shine, R. A.

1981-01-01

New observations are presented of impulsive UV and hard X-rays bursts in two solar flares obtained with instruments on Solar Maximum Mission. The UV bursts were observed in the Si IV and O IV emission lines, whose intensity ratio is density-sensitive. By comparing the spatially resolved Si IV/O IV observations with the corresponding hard X-ray observations, it is possible to study their spatial and temporal relationships. For one flare, the individual component spikes in the multiply peaked hard X-ray burst can be identified with different discrete Si IV/O IV flaring kernels of size 4 arcsec x 4 arcsec or smaller, which brighten up sequentially in time. For the other, many Si IV/O kernels, widely distributed over a large area, show impulsive bursts at the same time, which correlate with the main peak of the impulsive hard X-ray burst. The density of the flaring Si IV/O IV kernels is in the range from 5 x 10 to the 12th-13th/cu cm.

Suprathermal electron studies in the TCV tokamak: Design of a tomographic hard-x-ray spectrometer

International Nuclear Information System (INIS)

Gnesin, S.; Coda, S.; Decker, J.; Peysson, Y.

2008-01-01

Electron cyclotron resonance heating and electron cyclotron current drive, disruptive events, and sawtooth activity are all known to produce suprathermal electrons in fusion devices, motivating increasingly detailed studies of the generation and dynamics of this suprathermal population. Measurements have been performed in the past years in the tokamak a configuration variable (TCV) tokamak using a single pinhole hard-x-ray (HXR) camera and electron-cyclotron-emission radiometers, leading, in particular, to the identification of the crucial role of spatial transport in the physics of ECCD. The observation of a poloidal asymmetry in the emitted suprathermal bremsstrahlung radiation motivates the design of a proposed new tomographic HXR spectrometer reported in this paper. The design, which is based on a compact modified Soller collimator concept, is being aided by simulations of tomographic reconstruction. Quantitative criteria have been developed to optimize the design for the greatly variable shapes and positions of TCV plasmas.

Decimetric type III radio bursts and associated hard X-ray spikes

Science.gov (United States)

Dennis, B. R.; Benz, A. O.; Ranieri, M.; Simnett, G. M.

1984-01-01

For a relatively weak solar flare on August 6, 1981, at 10:32 UT, a detailed comparison is made between hard X-ray spikes and decimetric type III radio bursts. The hard X-ray observations are made at energies above 30 keV, and the radio data are obtained in the frequency range from 100 to 1000 MHz. The time resolution for all the data sets is approximately 0.1 s or better. The dynamic radio spectrum exhibits many fast drift type III radio bursts with both normal and reverse slope, whereas the X-ray time profile contains many well resolved short spikes with durations less than or equal to 1 s. Some of the X-ray spikes are seen to be associated in time with reverse-slope bursts, indicating either that the electron beams producing the radio burst contain two or three orders of magnitude more fast electrons than has previously been assumed or that the electron beams can induce the acceleration of additional electrons or occur in coincidence with this acceleration. A case is presented in which a normal slope radio burst at approximately 600 MHz occurs in coincidence with the peak of an X-ray spike to within 0.1 s.

An XMM-Newton study of the hard X-ray sky

Science.gov (United States)

Piconcelli, E.; Cappi, M.; Bassani, L.; Di Cocco, G.; Dadina, M.

2003-12-01

We report on the spectral properties of a sample of 90 hard X-ray selected serendipitous sources detected in 12 XMM-Newton observations with 1 law modified by Galactic absorption offers an acceptable fit to ~ 65% of the source spectra. This fit yields an average photon index of ≈ 1.55 over the whole sample. We also find that the mean slope of the QSOs in our sample turns out to remain nearly constant ( (≈ 1.8-1.9) between 0 1022 cm-2) is ~ 30%, with little evolution in the range 2 <≈ F2-10˜< 80 x 10-14 erg cm-2 s-1. Interestingly, this value is a factor ~ 2 lower than predicted by the synthesis models of the CXB. This finding, detected for the first time in this survey, therefore suggests that most of the heavily obscured objects which make up the bulk of the CXB will be found at lower fluxes (F2-10< 10-14 erg cm-2 s-1). This mismatch together with other recent observational evidences which contrast with CXB model predictions suggest that one (or more) of the assumptions usually included in these models need to be revised.

Hard X-ray phase-contrast microscope for observing transparent specimens

Energy Technology Data Exchange (ETDEWEB)

Kagoshima, Y.; Yokoyama, Y.; Niimi, T.; Koyama, T.; Tsusaka, Y.; Matsui, J. [Himeji Institute of Technology, Graduate School of Science, Hyogo (Japan); Takai, K. [Japan synchrotron Radiation Research Institute, Mikazuki, Hyogo (Japan)

2002-08-01

A hard X-ray transmission imaging microscope has been in use at the beamline BL24XU of Spring-8. It makes use of a phase zone plate made of tantalum as its X-ray lens, and is capable of imaging the structure as fine as 125-nm line-and-space pattern. The Zernike's phase-contrast method has been implemented to the microscope with phase plates made of gold. The photon energy was tuned to 12 keV just above the L{sub 3} absorption edge of gold (11.9 keV) in order to increase the image contrast. Polystyrene micro particles as transparent specimens were imaged clearly in the opposite image contrast with phase plates to shift the phase of the central order spectra in the back focal plane of the objective by one-quarter and three-quarters of a period, while the absorption contrast image showed little image contrast. Performance of the newly developed phase zone plate has been tested and it was confirmed that the structure as fine as 60-mm line-and-space pattern was able to be imaged. (authors)

Multilayer coating facility for the HEFT hard x-ray telescope

DEFF Research Database (Denmark)

Cooper-Jensen, Carsten P.; Christensen, Finn Erland; Chen, Hubert

2001-01-01

A planar magnetron sputtering facility has been established at the Danish Space Research Institute (DSRI) for the production coating of depth graded multilayers on the thermally slumped glass segments which form the basis for the hard X-ray telescope on the HEFT balloon project. The facility...

Impact of a Vertically Polarized Undulator on LCLS Hard X-ray Experiments

Energy Technology Data Exchange (ETDEWEB)

Fritz, David [SLAC National Accelerator Lab., Menlo Park, CA (United States)

2014-11-14

The LCLS-II project will install two variable gap, horizontally polarized undulators into the LCLS undulator hall. One undulator is designed to produce soft x-rays spanning an energy range of 200-1250 eV (SXU) while the other is designed for the hard spectral range of 1-25 keV (HXU). The hard x-ray LCLS instruments (X-ray Pump- Probe [XPP], X-ray correlation Spectroscopy [XCS], Coherent X-ray Imaging [CXI], Matter in Extreme Conditions [MEC]) will be repurposed to operate on the HXU line while two new soft x-ray beamlines will be created for the SXU line. An alternate HXU undulator design is being considered that could provide advantages over the present design choice. In particular, the project team is collaborating with Argonne National Laboratory to develop a vertically polarized undulator (VPU). A 1-m prototype VPU device was successfully constructed this year and a full size prototype is in process. A decision to alter the project baseline, which is the construction of a horizontally polarized device, must be made in the coming weeks to not impact the present project schedule. Please note that a change to the soft x-ray undulator is not under discussion at the moment.

On self-consistent ray-tracing and Fokker-Planck modeling of the hard X-ray emission during lower-hybrid current driven in Tokamaks

International Nuclear Information System (INIS)

Bizarro, J.P.; Peysson, Y.; Bonoli, P.T.; Carrasco, J.; Dudok de Wit, T.; Fuchs, V.; Hoang, G.T.; Litaudon, X.; Moreau, D.; Pocheau, C.; Shkarofsky, I.P.

1993-04-01

A detailed investigation is presented on the ability of combined ray-tracing and Fokker-Planck calculations to predict the hard x-ray (HXR) emission during lower-hybrid (LH) current drive in tokamaks when toroidally induced-ray-stochasticity is important. A large number of rays is used and the electron distribution function is obtained by self-consistently iterating the appropriate LH power deposition and Fokker-Planck calculations. Most of the experimentally observed features of the HXR emission are correctly predicted. It is found that corrections due to radial diffusion of suprathermal electrons and to radiation scattering by the inner wall can be significant

Rugby-like hohlraum experimental designs for demonstrating x-ray drive enhancement

Science.gov (United States)

Amendt, Peter; Cerjan, C.; Hinkel, D. E.; Milovich, J. L.; Park, H.-S.; Robey, H. F.

2008-01-01

A suite of experimental designs for the Omega laser facility [Boehly et al., Opt. Commun. 133, 495 (1997)] using rugby and cylindrical hohlraums is proposed to confirm the energetics benefits of rugby-shaped hohlraums over cylinders under optimal implosion symmetry conditions. Postprocessed Dante x-ray drive measurements predict a 12-17eV (23%-36%) peak hohlraum temperature (x-ray flux) enhancement for a 1ns flattop laser drive history. Simulated core self-emission x-ray histories also show earlier implosion times by 200-400ps, depending on the hohlraum case-to-capsule ratio and laser-entrance-hole size. Capsules filled with 10 or 50atm of deuterium (DD) are predicted to give in excess of 1010 neutrons in two-dimensional hohlraum simulations in the absence of mix, enabling DD burn history measurements for the first time in indirect-drive on Omega. Capsule designs with 50atm of DHe3 are also proposed to make use of proton slowing for independently verifying the drive benefits of rugby hohlraums. Scale-5/4 hohlraum designs are also introduced to provide further margin to potential laser-plasma-induced backscatter and hot-electron production.

Rugby-like hohlraum experimental designs for demonstrating x-ray drive enhancement

International Nuclear Information System (INIS)

Amendt, Peter; Cerjan, C.; Hinkel, D. E.; Milovich, J. L.; Park, H.-S.; Robey, H. F.

2008-01-01

A suite of experimental designs for the Omega laser facility [Boehly et al., Opt. Commun. 133, 495 (1997)] using rugby and cylindrical hohlraums is proposed to confirm the energetics benefits of rugby-shaped hohlraums over cylinders under optimal implosion symmetry conditions. Postprocessed Dante x-ray drive measurements predict a 12-17 eV (23%-36%) peak hohlraum temperature (x-ray flux) enhancement for a 1 ns flattop laser drive history. Simulated core self-emission x-ray histories also show earlier implosion times by 200-400 ps, depending on the hohlraum case-to-capsule ratio and laser-entrance-hole size. Capsules filled with 10 or 50 atm of deuterium (DD) are predicted to give in excess of 10 10 neutrons in two-dimensional hohlraum simulations in the absence of mix, enabling DD burn history measurements for the first time in indirect-drive on Omega. Capsule designs with 50 atm of D 3 He are also proposed to make use of proton slowing for independently verifying the drive benefits of rugby hohlraums. Scale-5/4 hohlraum designs are also introduced to provide further margin to potential laser-plasma-induced backscatter and hot-electron production

Young Stellar Objects from Soft to Hard X-rays

Science.gov (United States)

Güdel, Manuel

2009-05-01

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

Calibration of hard x-ray (15 - 50 keV) optics at the MPE test facility PANTER

Science.gov (United States)

Bräuninger, Heinrich; Burkert, Wolfgang; Hartner, Gisela D.; Citterio, Oberto; Ghigo, Mauro; Mazzoleni, Francesco; Pareschi, Giovanni; Spiga, Daniele

2004-02-01

The Max-Planck-Institut für extraterrestrische Physik (MPE) in Garching, Germany, operates the large X-ray beam line facility PANTER for testing astronomical systems. At PANTER a number of telescopes like EXOSAT, ROSAT, SAX, JET-X, ABRIXAS, XMM and SWIFT operating in the soft energy range (0.02 - 15 keV) have been successfully calibrated. In the present paper we report on an important upgrade recently implemented that enables the calibration of hard X-ray optics (from 15 up to 50 keV). Currently hard X-ray optics based on single and multilayer coating are being developed for several future X-ray missions. The hard X-ray calibrations at PANTER are carried out by a high energy source based on an electron gun and several anodes, able to cover the energy range from 4.5 up to 50 keV. It provides fluxes up to 104 counts/sec/cm2 at the instrument chamber with a stability better than 1%. As detector a pn-CCD camera operating between 0.2 and 50 keV and a collecting area of 36 cm2 is used. Taking into account the high energy resolution of the CCD (145 eV at 6 keV), a very easy way to operate the facility in hard X-ray is in energy-dispersive mode (i.e. with a broad-band beam). A double crystal monochromator is also available providing energies up to 20 keV. In this paper we present the first results obtained by using PANTER for hard X-ray characterizations, performed on prototype multilayer optics developed by the Osservatorio Astronomico di Brera (OAB), Milano, Italy, and the Harvard-Smithsonian Center for Astrophysics (CfA), Cambridge, MA, USA.

Comparison of hard X-ray spectra obtained by spectrometers on Hinotori and SMM and detection of 'superhot' component

Science.gov (United States)

Nitta, Nariaki

1988-01-01

Hard X-ray spectra in solar flares obtained by the broadband spectrometers aboard Hinotori and SMM are compared. Within the uncertainty brought about by assuming the typical energy of the background X-rays, spectra by the Hinotori spectrometer are usually consistent with those by the SMM spectrometer for flares in 1981. On the contrary, flares in 1982 persistently show 20-50-percent higher flux by Hinotori than by SMM. If this discrepancy is entirely attributable to errors in the calibration of energy ranges, the errors would be about 10 percent. Despite such a discrepancy in absolute flux, in the the decay phase of one flare, spectra revealed a hard X-ray component (probably a 'superhot' component) that could be explained neither by emission from a plasma at about 2 x 10 to the 7th K nor by a nonthermal power-law component. Imaging observations during this period show hard X-ray emission nearly cospatial with soft X-ray emission, in contrast with earlier times at which hard and soft X-rays come from different places.

Machine learning from hard x-ray surveys: applications to magnetic cataclysmic variable studies

Science.gov (United States)

Scaringi, Simone

2009-11-01

Within this thesis are discussed two main topics of contemporary astrophysics. The first is that of machine learning algorithms for astronomy whilst the second is that of magnetic cataclysmic variables (mCVs). To begin, an overview is given of ISINA: INTEGRAL Scouce Identifiction Network Algorithm. This machine learning algorithm, using random forests, is applied to the IBIS/ISGRI data set in order to ease the production of unbiased future soft gamma-ray source catalogues. The feature extraction process on an initial candidate list is described together with feature merging. Three trainng and testing sets are created in order to deal with the diverse time-scales encountered when dealing with the gamma-ray sky: one dealing with faint persistent source recognition, one dealing with strong persistent sources and a final one dealing with transients. For the latter, a new transient detection technique is introduced and described: the transient matrix. Finally the performance of the network is assessed and discussed using the testing set and some illustrative source examples. ISINA is also compared to the more conventional approach of visual inspection. Next mCVs are discussed, and in particular the properties arising from a hard X-ray selected sample which has proven remarkably efficient in detecting intermediate polars and asynchronous polars, two of the rarest type of cataclysmic variables (CVs). This thesis focuses particularly on the link between hard X-ray properties and spin/orbital periods. To this end, a new sample of these objects is constructed by cross-corelating candidate sources detected in INTEGRAL/IBIS observations against catalogues of known CVs. Also included in the analysis are hard X-ray Observations from Swift/BAT and SUZAKU/HXD in order to make the study more complete. It is found that most hard X-ray detected mCVs have Pspin/Porb<0.1 above the period gap. In this respect, attention is given to the very low number of detected systems in any ban

Theoretical modeling of Comptonized X-ray spectra of super-Eddington accretion flow: Origin of hard excess in ultraluminous X-ray sources

Science.gov (United States)

Kitaki, Takaaki; Mineshige, Shin; Ohsuga, Ken; Kawashima, Tomohisa

2017-12-01

X-ray continuum spectra of super-Eddington accretion flow are studied by means of Monte Carlo radiative transfer simulations based on the radiation hydrodynamic simulation data, in which both thermal- and bulk-Compton scatterings are taken into account. We compare the calculated spectra of accretion flow around black holes with masses of MBH = 10, 102, 103, and 104 M⊙ for a fixed mass injection rate (from the computational boundary at 103 rs) of 103 LEdd/c2 (with rs, LEdd, and c being the Schwarzschild radius, the Eddington luminosity, and the speed of light, respectively). The soft X-ray spectra exhibit mass dependence in accordance with the standard-disk relation; the maximum surface temperature is scaled as T ∝ M_{ BH}^{ -1/4}. The spectra in the hard X-ray band, by contrast with soft X-ray, look to be quite similar among different models, if we normalize the radiation luminosity by MBH. This reflects that the hard component is created by thermal- and bulk-Compton scatterings of soft photons originating from an accretion flow in the overheated and/or funnel regions, the temperatures of which have no dependence on mass. The hard X-ray spectra can be reproduced by a Wien spectrum with the temperature of T ˜ 3 keV accompanied by a hard excess at photon energy above several keV. The excess spectrum can be fitted well with a power law with a photon index of Γ ˜ 3. This feature is in good agreement with that of the recent NuSTAR observations of ULXs (ultra-luminous X-ray sources).

Design of a scattering polarimeter for hard X-ray astronomy

International Nuclear Information System (INIS)

Costa, E.; Cinti, M.N.; Feroci, M.; Matt, G.; Rapisarda, M.

1995-01-01

The design of a new hard X-ray Compton scattering polarimeter based on scintillating fibre technology is presented and studied in detail by means of Monte Carlo calculations. Several different configurations and materials have been tested in order to optimise the sensitivity in the medium/high energy X-ray band. A high sensitivity over the energy band 20-200 keV is obtained for a two material configuration. The advantages deriving from employing a new scintillating material, the YAP (YAlO 3 ), are also discussed. (orig.)

Hard X-ray Spectrum of Mkn 421 during the Active Phase

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging Solutions)

Spectral measurement of Mkn 421 were made in the hard X-ray energy band of ... In the canonical models for blazars, the observed radiation in radio, UV and low ... defined by a slat collimator specially designed with a sandwiched material of.

Variability in operation-based NO(x) emission factors with different test routes, and its effects on the real-driving emissions of light diesel vehicles.

Science.gov (United States)

Lee, Taewoo; Park, Junhong; Kwon, Sangil; Lee, Jongtae; Kim, Jeongsoo

2013-09-01

The objective of this study is to quantify the differences in NO(x) emissions between standard and non-standard driving and vehicle operating conditions, and to estimate by how much NO(x) emissions exceed the legislative emission limits under typical Korean road traffic conditions. Twelve Euro 3-5 light-duty diesel vehicles (LDDVs) manufactured in Korea were driven on a chassis dynamometer over the standard New European Driving Cycle (NEDC) and a representative Korean on-road driving cycle (KDC). NO(x) emissions, average speeds and accelerations were calculated for each 1-km trip segment, so called averaging windows. The results suggest that the NO(x) emissions of the tested vehicles are more susceptible to variations in the driving cycles than to those in the operating conditions. Even under comparable operating conditions, the NO(x) control capabilities of vehicles differ from each other, i.e., NO(x) control is weaker for the KDC than for the NEDC. The NO(x) emissions over the KDC for given vehicle operating conditions exceed those over the NEDC by more than a factor of 8. Consequently, on-road NO(x) emission factors are estimated here to exceed the Euro 5 emission limit by up to a factor of 8, 4 and 3 for typical Korean urban, rural, and motorway road traffic conditions, respectively. Our findings support the development of technical regulations for supplementary real-world emission tests for emission certification and the corresponding research actions taken by automotive industries. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of untethered SU-8 polymer scratch drive microrobots

KAUST Repository

Valencia Garcia, Manuel; Atallah, Tarek Nabil; Castro, David; Conchouso Gonzalez, David; Al Dosari, Mishari Ibraheem; Hammad, Rafat; Al Rawashdeh, Ehab Jamal; Zaher, Amir Omar; Kosel, Jü rgen; Foulds, Ian G.

2011-01-01

This paper presents the design, simulation, fabrication and testing of novel, untethered SU-8 polymer microrobots based on scratch drive actuators (SDAs). The design consists of two 100×120×10μm linked SDAs, individually operated close to their resonant frequencies. The resonant frequency and deflection behavior of an individual SDA can be controlled by its shape, thickness, and stiffening design features. As a result, paired SDAs can be actuated individually or simultaneously by a multifrequency driving signal, allowing for two-dimensional displacement. The fabrication process uses SU-8 as structural material and PMGI as sacrificial material. The SU-8 provides a flexible material for the SDA's plates as well as the bushing. Finally, a Cr/Au layer is blanket deposited to provide electrical conductivity.

Monitoring the Galactic - Search for Hard X-Ray Transients

Science.gov (United States)

Marshall, Francis

Hard X-ray transients with fluxs from ~1 to ~30 mCrab are a common feature of the galactic plane with apparent concentrations in specific regions of the plane. Concentrations in the Scutum and Carina fields probably indicate an enhancement of Be X-ray binaries along the tangent direction of two spiral arms. The frequency of outbursts suggest that at any one time 1 or 2 transients are active in the Scutum field alone. We propose weekly scans of the galactic plane to understand this population of sources. The scans will also monitor about 50 already known sources with better spectral information than available with the ASM.

SuperAGILE detects an X-ray burst from SAX J1750.8-2900

Science.gov (United States)

Pacciani, L.; Costa, E.; Del Monte, E.; Donnarumma, I.; Evangelista, Y.; Feroci, M.; Lapshov, I.; Lazzarotto, F.; Rapisarda, M.; Soffitta, P.; Argan, A.; Trois, A.; Tavani, M.; Piano, G.; Pucella, G.; D'Ammando, F.; Vittorini, V.; Bulgarelli, A.; Gianotti, F.; Trifoglio, M.; Di Cocco, G.; Labanti, C.; Fuschino, F.; Marisaldi, M.; Galli, M.; Chen, A.; Vercellone, S.; Giuliani, A.; Mereghetti, S.; Perotti, F.; Fornari, F.; Fiorini, M.; Caraveo, P.; Pellizzoni, A.; Barbiellini, G.; Longo, F.; Vallazza, E.; Picozza, P.; Morselli, A.; Prest, M.; Lipari, P.; Zanello, D.; Rappoldi, A.; Pittori, C.; Verrecchia, F.; Santolamazza, P.; Preger, B.; Giommi, P.; Salotti, L.

2008-10-01

While pointing at the Galactic Center region, SuperAGILE detected an X-ray burst from a position consistent with the neutron star transient SAX J1750.8-2900. This source was recently reported by Linares et al. (ATel #1662) as returning to a quiescent state, based on a Swift/XRT observation on August 14th 2008 (ATel #1662), after a long outburst started on March 2008 (Markwardt & Swank, ATel #1425), during which also SuperAGILE detected the source at hard X-rays at a flux level of about 80 mCrab (Pacciani et al., ATel #1428).

Applications of Hard X-ray Full-Field Transmission X-ray Microscopy at SSRL

International Nuclear Information System (INIS)

Liu, Y.; Andrews, J. C.; Mehta, A.; Pianetta, P.; Meirer, F.; Gil, S. Carrasco; Sciau, P.; Mester, Z.

2011-01-01

State-of-the-art hard x-ray full-field transmission x-ray microscopy (TXM) at beamline 6-2C of Stanford Synchrotron Radiation Lightsource has been applied to various research fields including biological, environmental, and material studies. With the capability of imaging a 32-micron field-of-view at 30-nm resolution using both absorption mode and Zernike phase contrast, the 3D morphology of yeast cells grown in gold-rich media was investigated. Quantitative evaluation of the absorption coefficient was performed for mercury nanoparticles in alfalfa roots exposed to mercury. Combining XANES and TXM, we also performed XANES-imaging on an ancient pottery sample from the Roman pottery workshop at LaGraufesenque (Aveyron).

Applications of Hard X-ray Full-Field Transmission X-ray Microscopy at SSRL

Science.gov (United States)

Liu, Y.; Andrews, J. C.; Meirer, F.; Mehta, A.; Gil, S. Carrasco; Sciau, P.; Mester, Z.; Pianetta, P.

2011-09-01

State-of-the-art hard x-ray full-field transmission x-ray microscopy (TXM) at beamline 6-2C of Stanford Synchrotron Radiation Lightsource has been applied to various research fields including biological, environmental, and material studies. With the capability of imaging a 32-micron field-of-view at 30-nm resolution using both absorption mode and Zernike phase contrast, the 3D morphology of yeast cells grown in gold-rich media was investigated. Quantitative evaluation of the absorption coefficient was performed for mercury nanoparticles in alfalfa roots exposed to mercury. Combining XANES and TXM, we also performed XANES-imaging on an ancient pottery sample from the Roman pottery workshop at LaGraufesenque (Aveyron).

Hard X ray lines from neutron stars

Energy Technology Data Exchange (ETDEWEB)

Polcaro, V.F.; Bazzano, A.; La Padula, C.; Ubertini, P.

1982-01-01

Experimental evidence is presented and evaluated concerning the features of the hard X-ray spectra detected in a number of cosmic X-ray sources which contain a neutron star. The strong emission line at cyclotron resonance detected in the spectrum of Her XI at an energy of 58 keV is evaluated and the implications of this finding are discussed. Also examined is the presence of spectral features in the energy range 20-80 keV found in the spectra of gamma-ray bursts, which have been interpreted as cyclotron resonance from interstellar-gas-accreting neutron stars. The less understood finding of a variable emission line at approximately 70 keV in the spectrum of the Crab Pulsar is considered. It is determined that several features varying with time are present in the spectra of cosmic X-ray sources associated with neutron stars. If these features are due to cyclotron resonance, it is suggested that they provide a direct measurement of neutron star magnetic fields on the order of 10 to the 11th-10 to the 13th Gauss. However, the physical condition of the emitting region and its geometry are still quite obscure.

Influences of pretreatment and hard baking on the mechanical reliability of SU-8 microstructures

International Nuclear Information System (INIS)

Morikaku, Toshiyuki; Kaibara, Yoshinori; Inoue, Shozo; Namazu, Takahiro; Inoue, Masatoshi; Miura, Takuya; Suzuki, Takaaki; Oohira, Fumikazu

2013-01-01

In this paper, the influences of pretreatment and hard baking on the mechanical characteristics of SU-8 microstructures are described. Four types of samples with different combinations of O 2 plasma ashing, primer coating and hard baking were prepared for shear strength tests and uniaxial tensile tests. Specially developed shear test equipment was used to experimentally measure the shear adhesion strength of SU-8 micro posts on a glass substrate. The adhesiveness was strengthened by hard baking at 200 °C for 60 min, whereas other pretreatment processes hardly affected the strength. The pretreatment and hard baking effects on the adhesive strength were compared with those on the fracture strength measured by uniaxial tensile testing. There were no influences of O 2 plasma ashing on both the strengths, and primer coating affected only tensile strength. The primer coating effect as well as the hard baking effect on stress relaxation phenomena in uniaxial tension was observed as well. Fourier transform infrared spectroscopy demonstrated that surface degradation and epoxide-ring opening polymerization would have given rise to the primer coating effect and the hard baking effect on the mechanical characteristics, respectively. (paper)

Influences of pretreatment and hard baking on the mechanical reliability of SU-8 microstructures

Science.gov (United States)

Morikaku, Toshiyuki; Kaibara, Yoshinori; Inoue, Masatoshi; Miura, Takuya; Suzuki, Takaaki; Oohira, Fumikazu; Inoue, Shozo; Namazu, Takahiro

2013-10-01

In this paper, the influences of pretreatment and hard baking on the mechanical characteristics of SU-8 microstructures are described. Four types of samples with different combinations of O2 plasma ashing, primer coating and hard baking were prepared for shear strength tests and uniaxial tensile tests. Specially developed shear test equipment was used to experimentally measure the shear adhesion strength of SU-8 micro posts on a glass substrate. The adhesiveness was strengthened by hard baking at 200 °C for 60 min, whereas other pretreatment processes hardly affected the strength. The pretreatment and hard baking effects on the adhesive strength were compared with those on the fracture strength measured by uniaxial tensile testing. There were no influences of O2 plasma ashing on both the strengths, and primer coating affected only tensile strength. The primer coating effect as well as the hard baking effect on stress relaxation phenomena in uniaxial tension was observed as well. Fourier transform infrared spectroscopy demonstrated that surface degradation and epoxide-ring opening polymerization would have given rise to the primer coating effect and the hard baking effect on the mechanical characteristics, respectively.

Sub-second pulsations simultaneously observed at microwaves and hard X-rays in a solar burst

International Nuclear Information System (INIS)

Takakura, T.; Degaonkar, S.S.; Nitta, N.; Ohki, N.

1982-11-01

Sub-second time structures have been found in the emissions during solar bursts in mm-waves and, independently, in hard X-rays. However, simultaneous observations of such fast time structure in mm radio and X-ray ranges has not been available so far. Accordingly, coordinated observations of solar bursts in November 1981 with a high time resolution of a few milliseconds were planned. The hard X-rays (30-40 KeV were observed with hard X-ray monitor (HXM) aboard the Hinotori Satellite with a time resolution of 7.81 ms and the radio emissions were observed on the ground with 45ft dish at Itapetinga Radio Observatory with a high time resolution (1 ms) and high sensitivities at 22 GHz and 44 GHz, supplemented by a patrol observation at 7 GHz with time resolution of 100 ms. The pulsations repeated with a period of about 300 ms. The physical implication of the good correlation is not clear at this stage, but it may give a clue to the understanding of the high energy phenomena occuring during the solar flares. (Author) [pt

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

Science.gov (United States)

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).

Fabrication of 200 nanometer period centimeter area hard x-ray absorption gratings by multilayer deposition

Science.gov (United States)

Lynch, S K; Liu, C; Morgan, N Y; Xiao, X; Gomella, A A; Mazilu, D; Bennett, E E; Assoufid, L; de Carlo, F; Wen, H

2012-01-01

We describe the design and fabrication trials of x-ray absorption gratings of 200 nm period and up to 100:1 depth-to-period ratios for full-field hard x-ray imaging applications. Hard x-ray phase-contrast imaging relies on gratings of ultra-small periods and sufficient depth to achieve high sensitivity. Current grating designs utilize lithographic processes to produce periodic vertical structures, where grating periods below 2.0 μm are difficult due to the extreme aspect ratios of the structures. In our design, multiple bilayers of x-ray transparent and opaque materials are deposited on a staircase substrate, and mostly on the floor surfaces of the steps only. When illuminated by an x-ray beam horizontally, the multilayer stack on each step functions as a micro-grating whose grating period is the thickness of a bilayer. The array of micro-gratings over the length of the staircase works as a single grating over a large area when continuity conditions are met. Since the layers can be nanometers thick and many microns wide, this design allows sub-micron grating periods and sufficient grating depth to modulate hard x-rays. We present the details of the fabrication process and diffraction profiles and contact radiography images showing successful intensity modulation of a 25 keV x-ray beam. PMID:23066175

Scintillation properties and X-ray irradiation hardness of Ce3+-doped Gd2O3-based scintillation glass

International Nuclear Information System (INIS)

Liu, Liwan; Shao, Chongyun; Zhang, Yu; Liao, Xili; Yang, Qiuhong; Hu, Lili; Chen, Danping

2016-01-01

Ce 3+ -doped Gd 2 O 3 -based scintillation glasses are prepared within an air or CO atmosphere. The effects of fluorine, lutetium, barium, and the melting atmosphere on the optical properties, scintillation properties and irradiation hardness are studied. Absorption spectra, luminescence spectra under UV and X-ray excitation, and the X-ray radiation-induced spectra are presented. The results show that the density can be increased by doping with fluorine, lutetium and barium. The luminescence intensity decreases after X-ray irradiation. Because of charge transfer quenching, fluorine and lutetium enhance the UV-excited and X-ray excited luminescence intensity, but barium decreases. Moreover, fluorine and lutetium are advantageous to irradiation hardness while barium is not. In addition, a non-reducing atmosphere provides a higher irradiation hardness than a reducing atmosphere. Fluorine-doped glass is promising to enhance luminescence intensity, promote irradiation hardness, and increase the density.

Study of runaway electrons using dosimetry of hard x-ray radiations in Damavand tokamak

Energy Technology Data Exchange (ETDEWEB)

Rasouli, C.; Pourshahab, B.; Rasouli, H. [Plasma Physics and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, AEOI, PO Box 14155-1339, Tehran (Iran, Islamic Republic of); Hosseini Pooya, S. M.; Orouji, T. [Radiation Application Research School, Nuclear Science and Technology Research Institute, AEOI, PO Box 14155-1339, Tehran (Iran, Islamic Republic of)

2014-05-15

In this work several studies have been conducted on hard x-ray emissions of Damavand tokamak based on radiation dosimetry using the Thermoluminescence method. The goal was to understand interactions of runaway electrons with plasma particles, vessel wall, and plasma facing components. Total of 354 GR-200 (LiF:Mg,Cu,P) thermoluminescence dosimeter (TLD) crystals have been placed on 118 points – three TLDs per point – to map hard x-ray radiation doses on the exterior of the vacuum vessel. Results show two distinctive levels of x-ray radiations doses on the exterior of the vessel. The low-dose area on which measured dose is about 0.5 mSv/shot. In the low-dose area there is no particular component inside the vessel. On the contrary, on high-dose area of the vessel, x-ray radiations dose exceeds 30 mSv/shot. The high-dose area coincides with the position of limiters, magnetic probe ducts, and vacuum vessel intersections. Among the high-dose areas, the highest level of dose is measured in the position of the limiter, which could be due to its direct contact with the plasma column and with runaway electrons. Direct collisions of runaway electrons with the vessel wall and plasma facing components make a major contribution for production of hard x-ray photons in Damavand tokamak.

SuperAGILE: The Hard X-ray Imager of AGILE

International Nuclear Information System (INIS)

Feroci, M.; Costa, E.; Barbanera, L.; Del Monte, E.; Di Persio, G.; Frutti, M.; Lapshov, I.; Lazzarotto, F.; Pacciani, L.; Porrovecchio, G.; Preger, B.; Rapisarda, M.; Rubini, A.; Soffitta, P.; Tavani, M.; Mastropietro, M.; Morelli, E.; Argan, A.; Ghirlanda, G.; Mereghetti, S.

2004-01-01

SuperAGILE is the hard X-ray (10-40 keV) imager for the gamma-ray mission AGILE, currently scheduled for launch in mid-2005. It is based on 4 Si-microstrip detectors, with a total geometric area of 1444 cm 2 (max effective about 300 cm 2 ), equipped with one-dimensional coded masks. The 4 detectors are perpendicularly oriented, in order to provide pairs of orthogonal one-dimensional images of the X-ray sky. The field of view of each 1-D detector is 107 deg. x 68 deg., at zero response, with an overlap in the central 68 deg. x 68 deg. area. The angular resolution on axis is 6 arcmin (pixel size). We present here the current status of the hardware development and the scientific potential for GRBs, for which an onboard trigger and imaging system will allow distributing locations through a fast communication telemetry link from AGILE to the ground

Renewed Activity from the X-Ray Transient SAXJ 1810.8-2609 with Integral

Science.gov (United States)

Fiocchi, M.; Natalucci, L.; Chenevez, J.; Bazzano, A.; Tarana, A.; Ubertini, P.; Brandt, S.; Beckmann, V.; Federici, M.; Galis, R.; Hudec, R.

2009-03-01

We report on the results of International Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of the neutron star low-mass X-ray binary SAX J1810.8-2609 during its latest active phase in 2007 August. The current outburst is the first one since 1998 and the derived luminosity is 1.1-2.6 ×1036 erg s-1 in the 20-100 keV energy range. This low outburst luminosity and the long-term time-average accretion rate of ~5 × 10-12 M sun yr-1 suggest that SAX J1810.8-2609 is a faint soft X-ray transient. During the flux increase, spectra are consistent with a thermal Comptonization model with a temperature plasma of kT e~ 23-30 keV and an optical depth of τ~ 1.2-1.5, independent of the luminosity of the system. This is a typical low hard spectral state for which the X-ray emission is attributed to the upscattering of soft seed photons by a hot, optically thin electron plasma. During the decay, spectra have a different shape, the high energy tail being compatible with a single power law. This confirm similar behavior observed by BeppoSAX during the previous outburst, with the absence of visible cutoff in the hard X-ray spectrum. INTEGRAL/JEM-X instrument observed four X-ray bursts in Fall 2007. The first one has the highest peak flux (≈3.5 crab in 3-25 keV) giving an upper limit to the distance of the source of about 5.7 kpc, for a L Edd ≈ 3.8 × 1038 erg s-1. The observed recurrence time of ~ 1.2 days and the ratio of the total energy emitted in the persistent flux to that emitted in the bursts (α~ 73) allow us to conclude that the burst fuel was composed by mixed hydrogen and helium with X >= 0.4. INTEGRAL is an ESA project with Instruments and Science Data Center funded by ESA member states, especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain; Czech Republic and Poland; and with the participation of Russia and USA.

Development of untethered SU-8 polymer scratch drive microrobots

KAUST Repository

Valencia Garcia, Manuel

2011-01-01

This paper presents the design, simulation, fabrication and testing of novel, untethered SU-8 polymer microrobots based on scratch drive actuators (SDAs). The design consists of two 100×120×10μm linked SDAs, individually operated close to their resonant frequencies. The resonant frequency and deflection behavior of an individual SDA can be controlled by its shape, thickness, and stiffening design features. As a result, paired SDAs can be actuated individually or simultaneously by a multifrequency driving signal, allowing for two-dimensional displacement. The fabrication process uses SU-8 as structural material and PMGI as sacrificial material. The SU-8 provides a flexible material for the SDA\\'s plates as well as the bushing. Finally, a Cr/Au layer is blanket deposited to provide electrical conductivity.

Design parameters of transmission curved crystal spectrometer for hard X-ray diagnoses

International Nuclear Information System (INIS)

Qian Feng; Cao Leifeng; Zhou Weimin; Zhao Zongqing; Gu Yuqiu; Yan Yonghong; Wei Lai; Xiao Shali

2013-01-01

The high resolving measurement of hard X-ray spectra generated in laser-produced plasma is usually performed using a cylindrically curved crystal spectrometer. In this paper, theoretical analysis and numerical simulation are performed to investigate the dependence of the energy range and resolving power on various design parameters, including crystal bending radius, source to crystal standoff distance, source size, location of the detector, etc. The investigation provides a means to design and develop cylindrically transmission curved crystal spectrometer which is used in hard X-ray diagnostics. The results show that crystal bending radius has a great influence on energy range of spectra and resolving power, and the separation between the spectral lines increases with the distance behind the focal circle faster than the line width, resulting in increased resolving power with distance. (authors)

Hard X-ray Full Field Nano-imaging of Bone and Nanowires at SSRL

International Nuclear Information System (INIS)

Andrews, Joy C.; Pianetta, Piero; Meirer, Florian; Chen Jie; Almeida, Eduardo; Meulen, Marjolein C. H. van der; Alwood, Joshua S.; Lee, Cathy; Zhu Jia; Cui Yi

2010-01-01

A hard X-ray full field microscope from Xradia Inc. has been installed at SSRL on a 54-pole wiggler end station at beam line 6-2. It has been optimized to operate from 5-14 keV with resolution as high as 30 nm. High quality images are achieved using a vertical beam stabilizer and condenser scanner with high efficiency zone plates with 30 nm outermost zone width. The microscope has been used in Zernike phase contrast, available at 5.4 keV and 8 keV, as well as absorption contrast to image a variety of biological, environmental and materials samples. Calibration of the X-ray attenuation with crystalline apatite enabled quantification of bone density of plate-like and rod-like regions of mouse bone trabecula. 3D tomography of individual lacuna revealed the surrounding cell canaliculi and processes. 3D tomography of chiral branched PbSe nanowires showed orthogonal branches around a central nanowire.

Hard X-ray Full Field Nano-imaging of Bone and Nanowires at SSRL.

Science.gov (United States)

Andrews, Joy C; Pianetta, Piero; Meirer, Florian; Chen, Jie; Almeida, Eduardo; van der Meulen, Marjolein C H; Alwood, Joshua S; Lee, Cathy; Zhu, Jia; Cui, Yi

2010-06-23

A hard X-ray full field microscope from Xradia Inc. has been installed at SSRL on a 54-pole wiggler end station at beam line 6-2. It has been optimized to operate from 5-14 keV with resolution as high as 30 nm. High quality images are achieved using a vertical beam stabilizer and condenser scanner with high efficiency zone plates with 30 nm outermost zone width. The microscope has been used in Zernike phase contrast, available at 5.4 keV and 8 keV, as well as absorption contrast to image a variety of biological, environmental and materials samples. Calibration of the X-ray attenuation with crystalline apatite enabled quantification of bone density of plate-like and rod-like regions of mouse bone trabecula. 3D tomography of individual lacuna revealed the surrounding cell canaliculi and processes. 3D tomography of chiral branched PbSe nanowires showed orthogonal branches around a central nanowire.

Hard X-ray Full Field Nano-imaging of Bone and Nanowires at SSRL

Science.gov (United States)

Andrews, Joy C.; Pianetta, Piero; Meirer, Florian; Chen, Jie; Almeida, Eduardo; van der Meulen, Marjolein C. H.; Alwood, Joshua S.; Lee, Cathy; Zhu, Jia; Cui, Yi

2010-06-01

A hard X-ray full field microscope from Xradia Inc. has been installed at SSRL on a 54-pole wiggler end station at beam line 6-2. It has been optimized to operate from 5-14 keV with resolution as high as 30 nm. High quality images are achieved using a vertical beam stabilizer and condenser scanner with high efficiency zone plates with 30 nm outermost zone width. The microscope has been used in Zernike phase contrast, available at 5.4 keV and 8 keV, as well as absorption contrast to image a variety of biological, environmental and materials samples. Calibration of the X-ray attenuation with crystalline apatite enabled quantification of bone density of plate-like and rod-like regions of mouse bone trabecula. 3D tomography of individual lacuna revealed the surrounding cell canaliculi and processes. 3D tomography of chiral branched PbSe nanowires showed orthogonal branches around a central nanowire.

The structural, electronic and magnetic properties of Ga{sub 8−x}Mn{sub x}As{sub 8} clusters

Energy Technology Data Exchange (ETDEWEB)

Gu, Gangxu [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Xiang, Gang, E-mail: gxiang@scu.edu.cn [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Luo, Jia; Tang, Zhijie [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Zhang, Xi, E-mail: xizhang@scu.edu.cn [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China)

2015-06-15

We systematically investigate the ground-state magnetic properties of Ga{sub 8−x}Mn{sub x}As{sub 8} clusters (x=0, 2, 4, 6, and 8) within the framework of density functional theory (DFT) using a strategy that successively adopts the particle swarm optimization (CALYPSO) code and fixed spin-moment (FSM) method. The results show that for Ga{sub 8−x}Mn{sub x}As{sub 8} in the ground states or low-lying isomers, Mn atoms tend to assemble at the core of the clusters and the ferrimagnetic Mn–Mn couplings are identified for Ga{sub 8−x}Mn{sub x}As{sub 8} (x=4, 6, and 8), while Ga{sub 8}As{sub 8} and Ga{sub 6}Mn{sub 2}As{sub 8} are nonmagnetic. The possibility of multiple ground states of Ga{sub 8−x}Mn{sub x}As{sub 8} (x=4, 6, and 8) is also demonstrated. The binding energy and LUMO–HOMO gap analysis show that Ga{sub 8−x}Mn{sub x}As{sub 8} clusters with large x are more likely synthesized and exhibit stronger chemical reactivity. - Highlights: • The ground-state structural and magnetic configurations of Ga{sub 8-x}Mn{sub x}As{sub 8} clusters are predicted by using the particle swarm optimization (CALYPSO) code and fixed spin-moment method. • For the ground state and low-lying isomers of Ga{sub 8−x}Mn{sub x}As{sub 8} clusters, Mn atoms are gathered at the core of cluster, and ferrimagnetic Mn–Mn coupling is found. • Ga{sub 8−x}Mn{sub x}As{sub 8} with large x is more likely formed and reacts with each other to create larger clusters.

Empirical evidence for son-killing X chromosomes and the operation of SA-zygotic drive.

Science.gov (United States)

Friberg, Urban; Stewart, Andrew D; Rice, William R

2011-01-01

Diploid organisms have two copies of all genes, but only one is carried by each haploid gamete and diploid offspring. This causes a fundamental genetic conflict over transmission rate between alternative alleles. Single genes, or gene clusters, only rarely code for the complex phenotypes needed to give them a transmission advantage (drive phenotype). However, all genes on a male's X and Y chromosomes co-segregate, allowing different sex-linked genes to code for different parts of the drive phenotype. Correspondingly, the well-characterized phenomenon of male gametic drive, occurring during haploid gametogenesis, is especially common on sex chromosomes. The new theory of sexually antagonistic zygotic drive of the sex chromosomes (SA-zygotic drive) extends the logic of gametic drive into the diploid phase of the lifecycle, whenever there is competition among siblings or harmful sib-sib mating. The X and Y are predicted to gain a transmission advantage by harming offspring of the sex that does not carry them. Here we analyzed a mutant X-chromosome in Drosophila simulans that produced an excess of daughters when transmitted from males. We developed a series of tests to differentiate between gametic and SA-zygotic drive, and provide multiple lines of evidence that SA-zygotic drive is responsible for the sex ratio bias. Driving sires produce about 50% more surviving daughters than sons. Sex-ratio distortion due to genetic conflict has evolved via gametic drive and maternally transmitted endosymbionts. Our data indicate that sex chromosomes can also drive by harming the non-carrier sex of offspring.

Empirical evidence for son-killing X chromosomes and the operation of SA-zygotic drive.

Directory of Open Access Journals (Sweden)

Urban Friberg

Full Text Available Diploid organisms have two copies of all genes, but only one is carried by each haploid gamete and diploid offspring. This causes a fundamental genetic conflict over transmission rate between alternative alleles. Single genes, or gene clusters, only rarely code for the complex phenotypes needed to give them a transmission advantage (drive phenotype. However, all genes on a male's X and Y chromosomes co-segregate, allowing different sex-linked genes to code for different parts of the drive phenotype. Correspondingly, the well-characterized phenomenon of male gametic drive, occurring during haploid gametogenesis, is especially common on sex chromosomes. The new theory of sexually antagonistic zygotic drive of the sex chromosomes (SA-zygotic drive extends the logic of gametic drive into the diploid phase of the lifecycle, whenever there is competition among siblings or harmful sib-sib mating. The X and Y are predicted to gain a transmission advantage by harming offspring of the sex that does not carry them.Here we analyzed a mutant X-chromosome in Drosophila simulans that produced an excess of daughters when transmitted from males. We developed a series of tests to differentiate between gametic and SA-zygotic drive, and provide multiple lines of evidence that SA-zygotic drive is responsible for the sex ratio bias. Driving sires produce about 50% more surviving daughters than sons.Sex-ratio distortion due to genetic conflict has evolved via gametic drive and maternally transmitted endosymbionts. Our data indicate that sex chromosomes can also drive by harming the non-carrier sex of offspring.

Hard X-ray nano-focusing with Montel mirror optics

Energy Technology Data Exchange (ETDEWEB)

Liu Wenjun, E-mail: wjliu@anl.gov [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Ice, Gene E. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Assoufid, Lahsen; Liu Chian; Shi Bing; Zschack, Paul [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Tischler, Jon [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Qian Jun; Khachartryan, Ruben; Shu Deming [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States)

2011-09-01

Kirkpatrick-Baez mirrors in the Montel (or nested) configuration were tested for hard X-ray nanoscale focusing at a third generation synchrotron beamline. In this scheme, two mirrors, mounted side-by-side and perpendicular to each other, provide for a more compact focusing system and a much higher demagnification and flux than the traditional sequential K-B mirror arrangement. They can accept up to a 120 {mu}mx120 {mu}m incident X-ray beam with a long working distance of 40 mm and broad-bandpass of energies up to {approx}30 keV. Initial test demonstrated a focal spot of about 150 nm in both horizontal and vertical directions with either polychromatic or monochromatic beam. Montel mirror optics is important and very appealing for achromatic X-ray nanoscale focusing in conventional non-extra-long synchrotron beamlines.

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

Science.gov (United States)

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.

Study of Moessbauer effect on LiFe5-x Alx O8, LiFe 5-x Gax O8 and LiGa5-x Fex O8 systems

International Nuclear Information System (INIS)

Barthem, V.M.T.S.

1982-01-01

The measures obtained by Moessbauer spectroscopy from LiFe 5-x Ga x O 8 and LiFe 5-x Al x O 8 systems are presented. A comparative study of the influences of dopant diamagnetic ions on magnetic structures of lithium ferrite was performed. The LiGa 5-x Fe x O 8 systems were analysed based on the existing data from LiAl 5-x Fe x O 8 systems, otaining informations about the iron ion behaviour in both matrices. (M.C.K.) [pt

RAPID SPECTRAL CHANGES OF CYGNUS X-1 IN THE LOW/HARD STATE WITH SUZAKU

Energy Technology Data Exchange (ETDEWEB)

Yamada, S.; Makishima, K. [Cosmic Radiation Laboratory, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198 (Japan); Negoro, H. [Department of Physics, College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Torii, S.; Noda, H. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Mineshige, S. [Department of Astronomy, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan)

2013-04-20

Rapid spectral changes in the hard X-ray on a timescale down to {approx}0.1 s are studied by applying a ''shot analysis'' technique to the Suzaku observations of the black hole binary Cygnus X-1, performed on 2008 April 18 during the low/hard state. We successfully obtained the shot profiles, covering 10-200 keV with the Suzaku HXD-PIN and HXD-GSO detector. It is notable that the 100-200 keV shot profile is acquired for the first time owing to the HXD-GSO detector. The intensity changes in a time-symmetric way, though the hardness changes in a time-asymmetric way. When the shot-phase-resolved spectra are quantified with the Compton model, the Compton y-parameter and the electron temperature are found to decrease gradually through the rising phase of the shot, while the optical depth appears to increase. All the parameters return to their time-averaged values immediately within 0.1 s past the shot peak. We have not only confirmed this feature previously found in energies below {approx}60 keV, but also found that the spectral change is more prominent in energies above {approx}100 keV, implying the existence of some instant mechanism for direct entropy production. We discuss possible interpretations of the rapid spectral changes in the hard X-ray band.

Effect of Anneal temperature and Time on Change of Texture and Hardness of Al-Cu-Mg

International Nuclear Information System (INIS)

Masrukan; Adolf Asih, S.

2000-01-01

Observation of the effect of annealing temperature to its texture and hardness of the Al-Cu-Mg has been done. In this experiments aluminium alloy powder and 5 pieces cubes of this alloy with size of 8 x 8 x 8 mm 3 were used. The powder was not annealed, 2 pieces cube were annealed for 20 hours at temperatures of 200 o C and 300 o respectively, finally 3 pieces cube were annealed at temperature of 400 o C. Texture measurement was done using x-ray diffraction with wave length of 1.78892 A using inverse pole figure method. The hardness testing results at constant temperature of 400 o C and various time indicated that the hardness values are decreased with increasing annealed time. Also, at hardness testing for constant time and various annealing temperatures indicated that the hardness values decreased with increasing annealing temperature

Signatures of Synchrotron: Low-cutoff X-ray emission and the hard X-ray spectrum of Cas A

Science.gov (United States)

Stage, Michael D.; Fedor, Emily Elizabeth; Martina-Hood, Hyourin

2018-06-01

In soft X-rays, bright, young Galactic remnants (Cas A, Kepler, Tycho, etc.) present thermal line emission and bremsstrahlung from ejecta, and synchrotron radiation from the shocks. Their hard X-ray spectra tend to be dominated by power-law sources. However, it can be non-trivial to discriminate between contributions from processes such as synchrotron and bremsstrahlung from nonthermally accelerated electrons, even though the energies of the electrons producing this radiation may be very different. Spatially-resolved spectroscopic analysis of 0.5-10 keV observations with, e.g., Chandracan provide leverage in identifying the processes and their locations. Previously, Stage & Allen (2006), Allen & Stage (2007) and Stage & Allen (2011) identified regions characterized by high-cutoff synchrotron radiation. Extrapolating synchrotron model fits to the emission in the Chandra band, they estimated the synchrotron contribution to the hard X-ray spectrum at about one-third the observed flux, fitting the balance with nonthermal bremsstrahlung emission produced by nonthermal electrons in the ejecta. Although it is unlikely this analysis missed regions of the highest-cutoff synchrotron emission, which supplies the bulk of the synchrotron above 15 keV, it may have missed regions of lower-cutoff emission, especially if they are near bright ejecta and the reverse shock. These regions cannot explain the emission at the highest energies (~50 keV), but may make significant contributions to the hard spectrum at lower energies (~10 keV). Using the technique described in Fedor, Martina-Hood & Stage (this meeting), we revisit the analysis to include regions that may be dominated by low-cutoff synchrotron, located in the interior of the remnant, and/or correlated with the reverse shock. Identifying X-ray emission from accelerated electrons associated with the reverse-shock would have important implications for synchrotron and non-thermal bremsstrahlung radiation above the 10 keV.

The Correlation between Hard X-Ray Peak Flux and Soft X-Ray Peak Flux in the Outburst Rise of Low-Mass X-Ray Binaries

NARCIS (Netherlands)

Yu, W.; van der Klis, M.; Fender, R.P.

2004-01-01

We have analyzed Rossi X-Ray Timing Explorer pointed observations of the outbursts of black hole and neutron star soft X-ray transients in which an initial low/hard state, or ``island'' state, followed by a transition to a softer state was observed. In three sources-the black hole transient XTE

Ronchi test for characterization of nanofocusing optics at a hard x-ray free-electron laser.

Science.gov (United States)

Nilsson, Daniel; Uhlén, Fredrik; Holmberg, Anders; Hertz, Hans M; Schropp, Andreas; Patommel, Jens; Hoppe, Robert; Seiboth, Frank; Meier, Vivienne; Schroer, Christian G; Galtier, Eric; Nagler, Bob; Lee, Hae Ja; Vogt, Ulrich

2012-12-15

We demonstrate the use of the classical Ronchi test to characterize aberrations in focusing optics at a hard x-ray free-electron laser. A grating is placed close to the focus and the interference between the different orders after the grating is observed in the far field. Any aberrations in the beam or the optics will distort the interference fringes. The method is simple to implement and can provide single-shot information about the focusing quality. We used the Ronchi test to measure the aberrations in a nanofocusing Fresnel zone plate at the Linac Coherent Light Source at 8.194 keV.

BaYb2F8, a new radiation hard Cherenkov radiator for electromagnetic calorimeters

International Nuclear Information System (INIS)

Aseev, A.A.; Devitsin, E.G.; Komar, A.A.; Kozlov, V.A.; Hovsepyan, Yu.I.; Potashov, S.Yu.; Sokolovsky, K.A.; Uvarova, T.V.; Vasilchenko, V.G.

1992-01-01

Radiation hardness and optical properties of a new Cherenkov radiator, heavy fluoride BaYb 2 F 8 doped with various elements, have been studied. The above mentioned crystal has the density of 7 g/cm 3 , the radiation length is 1.28 cm and the Moliere radius 2.44 cm. High radiation hardness has been demonstrated for BaYb 2 F 8 doped with Tm, Pr, Tb. (orig.)

Recycling potential of neodymium: the case of computer hard disk drives.

Science.gov (United States)

Sprecher, Benjamin; Kleijn, Rene; Kramer, Gert Jan

2014-08-19

Neodymium, one of the more critically scarce rare earth metals, is often used in sustainable technologies. In this study, we investigate the potential contribution of neodymium recycling to reducing scarcity in supply, with a case study on computer hard disk drives (HDDs). We first review the literature on neodymium production and recycling potential. From this review, we find that recycling of computer HDDs is currently the most feasible pathway toward large-scale recycling of neodymium, even though HDDs do not represent the largest application of neodymium. We then use a combination of dynamic modeling and empirical experiments to conclude that within the application of NdFeB magnets for HDDs, the potential for loop-closing is significant: up to 57% in 2017. However, compared to the total NdFeB production capacity, the recovery potential from HDDs is relatively small (in the 1-3% range). The distributed nature of neodymium poses a significant challenge for recycling of neodymium.

SWIFT OBSERVATIONS OF HARD X-RAY EMITTING WHITE DWARFS IN SYMBIOTIC STARS

International Nuclear Information System (INIS)

Kennea, J. A.; Burrows, D. N.; Mukai, K.; Markwardt, C. B.; Sokoloski, J. L.; Luna, G. J. M.; Tueller, J.

2009-01-01

The X-ray emission from most accreting white dwarfs (WDs) in symbiotic binary stars is quite soft. Several symbiotic WDs, however, produce strong X-ray emission at energies greater than ∼20 keV. The Swift Burst Alert Telescope (BAT) instrument has detected hard X-ray emission from four such accreting WDs in symbiotic stars: RT Cru, T CrB, CD -57 3057, and CH Cyg. In one case (RT Cru), Swift detected X-rays out to greater than 50 keV at >5σ confidence level. Combining data from the X-Ray Telescope (XRT) and BAT detectors, we find that the 0.3-150 keV spectra of RT Cru, T CrB, and CD -57 3057 are well described by emission from a single-temperature, optically thin thermal plasma, plus an unresolved 6.4-6.9 keV Fe line complex. The X-ray spectrum of CH Cyg contains an additional bright soft component. For all four systems, the spectra suffer high levels of absorption from material that both fully and partially covers the source of hard X-rays. The XRT data did not show any of the rapid, periodic variations that one would expect if the X-ray emission were due to accretion onto a rotating, highly magnetized WD. The X-rays were thus more likely from the accretion-disk boundary layer around a massive, non-magnetic WD in each binary. The X-ray emission from RT Cru varied on timescales of a few days. This variability is consistent with being due to changes in the absorber that partially covers the source, suggesting localized absorption from a clumpy medium moving into the line of sight. The X-ray emission from CD -57 3057 and T CrB also varied during the nine months of Swift observations, in a manner that was also consistent with variable absorption.

Extending synchrotron-based atomic physics experiments into the hard X-ray region

International Nuclear Information System (INIS)

LeBrun, T.

1996-01-01

The high-brightness, hard x-ray beams available from third-generation synchrotron sources are opening new opportunities to study the deepest inner shells of atoms, an area where little work has been done and phenomena not observed in less tightly bound inner-shells are manifested. In addition scattering processes which are weak at lower energies become important, providing another tool to investigate atomic structure as well as an opportunity to study photon/atom interactions beyond photoabsorption. In this contribution the authors discuss some of the issues related to extending synchrotron-based atomic physics experiments into the hard x-ray region from the physical and the experimental point of view. They close with a discussion of a technique, resonant Raman scattering, that may prove invaluable in determining the spectra of the very highly-excited states resulting from the excitation of deep inner shells

Hardness enhancement and oxidation resistance of nanocrystalline TiN/Mo xC multilayer films

International Nuclear Information System (INIS)

Liu, Q.; Wang, X.P.; Liang, F.J.; Wang, J.X.; Fang, Q.F.

2006-01-01

In this paper the influence of the layer's microstructure on the hardness enhancement in multilayer nanocrystalline films and the oxidation resistance are studied. The TiN/Mo x C multilayer films at different modulation period, and Mo x C and TiN monolayer films were deposited on the (0 0 1) silicon wafers and molybdenum sheets by rf and dc magnetron sputtering. The monolayer TiN films with a thickness of about 2 μm are of pure face-center cubic TiN phase, while the monolayer Mo x C films consist of two phases, one of which is body-center cubic Mo and the other is hexagonal Mo 2 C as determined by XRD. The coarse columnar grains of about 200 nm in the monolayer TiN films become much smaller or disappear in the multilayer films. The hardness enhancement of the multilayer films takes place at the modulation period of 320 nm, which can reach to 26 GPa and is much higher than the values of Mo x C and TiN monolayer films. This enhancement in hardness can be explained as the decrease in the size and/or disappearance of columnar grains in the TiN layer. The Young's modulus in the temperature range from 100 to 400 deg. C increases with decreasing modulation period. It is found that about 100 nm thick TiN films can increase largely the oxidation resistance of Mo x C films

Long duration hard X-ray transatlantic payload

International Nuclear Information System (INIS)

La Padula, C.D.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; Patriarca, R.; Polcaro, V.F.; Ubertini, P.

1981-01-01

The HXR80M large-area hard X-ray experiment, to be flown aboard a transatlantic balloon, is described. The detectors are two multiwire spectroscopic proportional counters (MWSPC) with a 2700-sq-cm sensitive area each. The two detectors are filled with an extremely pure xenon-isobutane mixture at high pressure (3-6 atm) in order to obtain good spectral resolution and high efficiency. The onboard data handling is performed by microprocessor-controlled electronics. The scientific aim of the experiment is the survey of the sky belt around the 38th parallel and in particular the observation of faint galactic objects and galactic binary systems in the 15-200 keV range

INTEGRAL detection of a hard X-ray transient in NGC 6440

DEFF Research Database (Denmark)

Kuulkers, E.; Bozzo, E.; Bazzano, A.

2015-01-01

Referred to by ATel #: 7106, 7136, 7183 Tweet During INTEGRAL Galactic bulge monitoring (e.g., ATel #438) observations performed on UT 2015 February 17 at 12.53-16:45, IBIS/ISGRI detected renewed activity at hard X-rays from a transient within the Globular Cluster NGC 6440. The best determined...

AstroSat /LAXPC Observation of Cygnus X-1 in the Hard State

Energy Technology Data Exchange (ETDEWEB)

Misra, Ranjeev; Pahari, Mayukh [Inter-University Centre for Astronomy and Astrophysics, Pune 411007 (India); Yadav, J S; Chauhan, Jai Verdhan; Antia, H M; Chitnis, V R; Dedhia, Dhiraj; Katoch, Tilak; Madhwani, P.; Shah, Parag [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai (India); Agrawal, P C [UM-DAE Center of Excellence for Basic Sciences, University of Mumbai, Kalina, Mumbai-400098 (India); Manchanda, R K [University of Mumbai, Kalina, Mumbai-400098 (India); Paul, B, E-mail: rmisra@iucaa.in [Dept. of Astronomy and Astrophysics, Raman Research Institute, Bengaluru-560080 (India)

2017-02-01

We report the first analysis of data from AstroSat /LAXPC observations of Cygnus X-1 in 2016 January. LAXPC spectra reveals that the source was in the canonical hard state, represented by a prominent thermal Comptonization component having a photon index of ∼1.8 and high temperature of kT{sub e} > 60 keV along with weak reflection and possible disk emission. The power spectrum can be characterized by two broad lorentzian functions centered at ∼0.4 and ∼3 Hz. The rms of the low-frequency component decreases from ∼15% at around 4 keV to ∼10% at around 50 keV, while that of the high-frequency one varies less rapidly from ∼13.5% to ∼11.5% in the same energy range. The time lag between the hard (20–40 keV) and soft (5–10 keV) bands varies in a step-like manner being nearly constant at ∼50 milliseconds from 0.3 to 0.9 Hz, decreasing to ∼8 milliseconds from 2 to 5 Hz and finally dropping to ∼2 milliseconds for higher frequencies. The time lags increase with energy for both the low and high-frequency components. The event mode LAXPC data allows for flux resolved spectral analysis on a timescale of 1 s, which clearly shows that the photon index increased from ∼1.72 to ∼1.80 as the flux increased by nearly a factor of two. We discuss the results in the framework of the fluctuation propagation model.

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

Energy Technology Data Exchange (ETDEWEB)

Coleman, J. E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Welch, D. R.; Miller, C. L. [Voss Scientific, Albuquerque, New Mexico 87108 (United States)

2015-11-14

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

Probing deeper by hard x-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Risterucci, P.; Renault, O., E-mail: olivier.renault@cea.fr; Martinez, E.; Delaye, V. [CEA, LETI, MINATEC Campus, 38054 Grenoble Cedex 09 (France); Detlefs, B. [CEA, LETI, MINATEC Campus, 38054 Grenoble Cedex 09 (France); European Synchrotron Radiation Facility, 6 rue Jules Horowitz, F-38043 Grenoble (France); Zegenhagen, J. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, F-38043 Grenoble (France); Gaumer, C. [STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles (France); Grenet, G. [Institut des Nanotechnologies de Lyon (INL), UMR CNRS 5270, Ecole Centrale de Lyon, 36, avenue Guy de Collongue 69 134 Ecully Cedex (France); Tougaard, S. [Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M (Denmark)

2014-02-03

We report an hard x-ray photoelectron spectroscopy method combining high excitation energy (15 keV) and improved modelling of the core-level energy loss features. It provides depth distribution of deeply buried layers with very high sensitivity. We show that a conventional approach relying on intensities of the core-level peaks is unreliable due to intense plasmon losses. We reliably determine the depth distribution of 1 ML La in a high-κ/metal gate stack capped with 50 nm a-Si. The method extends the sensitivity of photoelectron spectroscopy to depths beyond 50 nm.

Efficient focusing of 8 keV X-rays with multilayer Fresnel zone plates fabricated by atomic layer deposition and focused ion beam milling

International Nuclear Information System (INIS)

Mayer, Marcel; Keskinbora, Kahraman; Grévent, Corinne; Szeghalmi, Adriana; Knez, Mato; Weigand, Markus; Snigirev, Anatoly; Snigireva, Irina; Schütz, Gisela

2013-01-01

The fabrication and performance of multilayer Al 2 O 3 /Ta 2 O 5 Fresnel zone plates in the hard X-ray range and a discussion of possible future developments considering available materials are reported. Fresnel zone plates (FZPs) recently showed significant improvement by focusing soft X-rays down to ∼10 nm. In contrast to soft X-rays, generally a very high aspect ratio FZP is needed for efficient focusing of hard X-rays. Therefore, FZPs had limited success in the hard X-ray range owing to difficulties of manufacturing high-aspect-ratio zone plates using conventional techniques. Here, employing a method of fabrication based on atomic layer deposition (ALD) and focused ion beam (FIB) milling, FZPs with very high aspect ratios were prepared. Such multilayer FZPs with outermost zone widths of 10 and 35 nm and aspect ratios of up to 243 were tested for their focusing properties at 8 keV and shown to focus hard X-rays efficiently. This success was enabled by the outstanding layer quality thanks to ALD. Via the use of FIB for slicing the multilayer structures, desired aspect ratios could be obtained by precisely controlling the thickness. Experimental diffraction efficiencies of multilayer FZPs fabricated via this combination reached up to 15.58% at 8 keV. In addition, scanning transmission X-ray microscopy experiments at 1.5 keV were carried out using one of the multilayer FZPs and resolved a 60 nm feature size. Finally, the prospective of different material combinations with various outermost zone widths at 8 and 17 keV is discussed in the light of the coupled wave theory and the thin-grating approximation. Al 2 O 3 /Ir is outlined as a promising future material candidate for extremely high resolution with a theoretical efficiency of more than 20% for as small an outermost zone width as 10 nm at 17 keV

Electronic structure of YbNiX{sub 3} (X =Si, Ge) studied by hard X-ray photoemission spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Sato, Hitoshi; Shimada, Kenya; Namatame, Hirofumi [Hiroshima Synchrotron Radiation Center, Hiroshima University, Kagamiyama 2-313, Higashi-Hiroshima 739-0046 (Japan); Utsumi, Yuki [Max-Planck Institute for Chemical Physics of Solids, 01187 Dresden (Germany); Kodama, Junichi; Nagata, Heisuke [Graduate School of Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan); Avila, Marcos A.; Ribeiro, Raquel A. [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Santo Andre - SP, 09210-580 (Brazil); Umeo, Kazunori [Cryogenics and Instrumental Analysis Division, N-BARD, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Takabatake, Toshiro [Department of Quantum Matter, AdSM, Hiroshima University, Higashi-Hiroshima 739-8530 (Japan); Institute for Advanced Materials Research, Hiroshima University, Higashi-Hiroshima 739-8530 (Japan); Mimura, Kojiro; Motonami, Satoru; Anzai, Hiroaki [Graduate School of Engineering, Osaka Prefecture University, Sakai 599-8531 (Japan); Ueda, Shigenori [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148 (Japan); Taniguchi, Masaki [Hiroshima Synchrotron Radiation Center, Hiroshima University, Kagamiyama 2-313, Higashi-Hiroshima 739-0046 (Japan); Graduate School of Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan)

2015-06-15

lectronic structure of the Kondo lattices YbNiX{sub 3} (X =Si, Ge) has been investigated by means of hard x-ray photoemission spectroscopy (HAXPES) with hν = 5.95 keV. From the Yb 3d HAXPES spectra, the Yb valence in YbNiSi{sub 3} is estimated to be ∝ 2.92, which is almost temperature-independent. On the other hand, the valence in YbNiGe{sub 3} is estimated to be 2.48 at 300 K, showing significant valence fluctuation, and gradually decreases to 2.41 at 20 K on cooling. The Ni 2p{sub 3/2} and Yb{sup 3+} 4f peaks exhibit opposite energy shifts amounting to ∝ 0.6 eV between YbNiSi{sub 3} and YbNiGe{sub 3}. We propose a simple model for the electronic structure of YbNiX{sub 3} based on the HAXPES results. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Reduced polymorphism associated with X chromosome meiotic drive in the stalk-eyed fly Teleopsis dalmanni.

Directory of Open Access Journals (Sweden)

Sarah J Christianson

Full Text Available Sex chromosome meiotic drive has been suggested as a cause of several evolutionary genetic phenomena, including genomic conflicts that give rise to reproductive isolation between new species. In this paper we present a population genetic analysis of X chromosome drive in the stalk-eyed fly, Teleopsis dalmanni, to determine how this natural polymorphism influences genetic diversity. We analyzed patterns of DNA sequence variation at two X-linked regions (comprising 1325 bp approximately 50 cM apart and one autosomal region (comprising 921 bp for 50 males, half of which were collected in the field from one of two allopatric locations and the other half were derived from lab-reared individuals with known brood sex ratios. These two populations are recently diverged but exhibit partial postzygotic reproductive isolation, i.e. crosses produce sterile hybrid males and fertile females. We find no nucleotide or microsatellite variation on the drive X chromosome, whereas the same individuals show levels of variation at autosomal regions that are similar to field-collected flies. Furthermore, one field-caught individual collected 10 years previously had a nearly identical X haplotype to the drive X, and is over 2% divergent from other haplotypes sampled from the field. These results are consistent with a selective sweep that has removed genetic variation from much of the drive X chromosome. We discuss how this finding may relate to the rapid evolution of postzygotic reproductive isolation that has been documented for these flies.

Interplay of hard and soft physics in small x deep inelastic processes

International Nuclear Information System (INIS)

Abramowicz, H.

1995-01-01

Coherence phenomena, the increase with energy of coherence length and the nonuniversality of parton structure of the effective pomeron are explained. New hard phenomena directly calculable in QCD such as diffractive electroproduction of states with M 2 2 and the color transparency phenomenon as well as new options to measure the light-cone wave functions of various hadrons are considered. An analogue of Bjorken scaling is predicted for the diffractive electroproduction of ρ mesons at large momentum transfers and for the production of large rapidity gap events, as observed at HERA. A phenomenological QCD evolution equation is suggested to calculate the basic characteristics of the large rapidity gap events. The increase of parton densities at small x as well as new means to disentangle experimentally soft and hard physics are considered. We discuss constraints on the increase of deep inelastic amplitudes with Q 2 derived from the inconsistency of QCD predictions for inclusive and exclusive processes and from unitarity of the S matrix for collisions of wave packets. New ways to probe QCD physics of hard processes at large longitudinal distances and to answer the long standing problems on the origin of the pomeron are suggested. Unresolved problems and perspectives of small x physics are also outlined. (orig.)

Modeling Flare Hard X-ray Emission from Electrons in Contracting Magnetic Islands

Science.gov (United States)

Guidoni, Silvina E.; Allred, Joel C.; Alaoui, Meriem; Holman, Gordon D.; DeVore, C. Richard; Karpen, Judith T.

2016-05-01

The mechanism that accelerates particles to the energies required to produce the observed impulsive hard X-ray emission in solar flares is not well understood. It is generally accepted that this emission is produced by a non-thermal beam of electrons that collides with the ambient ions as the beam propagates from the top of a flare loop to its footpoints. Most current models that investigate this transport assume an injected beam with an initial energy spectrum inferred from observed hard X-ray spectra, usually a power law with a low-energy cutoff. In our previous work (Guidoni et al. 2016), we proposed an analytical method to estimate particle energy gain in contracting, large-scale, 2.5-dimensional magnetic islands, based on a kinetic model by Drake et al. (2010). We applied this method to sunward-moving islands formed high in the corona during fast reconnection in a simulated eruptive flare. The overarching purpose of the present work is to test this proposed acceleration model by estimating the hard X-ray flux resulting from its predicted accelerated-particle distribution functions. To do so, we have coupled our model to a unified computational framework that simulates the propagation of an injected beam as it deposits energy and momentum along its way (Allred et al. 2015). This framework includes the effects of radiative transfer and return currents, necessary to estimate flare emission that can be compared directly to observations. We will present preliminary results of the coupling between these models.

The detection of hard x-rays (10-140 KeV) by channel plate electron multipliers

International Nuclear Information System (INIS)

Bateman, J.E.

1976-12-01

Results are presented indicating that hard X-rays in the energy range 10 to 50 keV can be detected with good efficiency (5 to 10%) in channel plate electron multipliers (CPEM). From 50 keV to 140 keV the detection efficiency lies in the range 1 to 2%. A simple physical model is developed which indicates that not only can good detection efficiency be obtained but that very good X-ray imaging is possible. The model predicts that with further development, a wideband, hard X-ray detector can be realised with a detection efficiency in the range 5 to 20% and spatial response better than 10 lp/mm in the energy range 10 to 140 keV. (author)

Hard and soft x-ray study of the correlation between substrate quality and multilayer performance for Co/C coating produced by electron beam evaporation using ion polishing

DEFF Research Database (Denmark)

Abdali, S.; Christensen, Finn Erland; Spiller, E.

1995-01-01

as the transverse scan have demonstrated different qualities, influenced by the different substrates. The investigations were performed with both hard x-ray (8.05 keV) as well as soft x-ray (0.25 keV). The reflectivity varies up to factor 3 between the best and the worst of these substrates. The results...

Nustar Detection of Hard X-Ray Phase Lags from the Accreting Pulsar GS 0834-430

DEFF Research Database (Denmark)

Miyasaka, Hiromasa; Bachetti, Matteo; Harrison, Fiona A.

2013-01-01

The Nuclear Spectroscopic Telescope Array hard X-ray telescope observed the transient Be/X-ray binary GS 0834-430 during its 2012 outburst-the first active state of this system observed in the past 19 yr. We performed timing and spectral analysis and measured the X-ray spectrum between 3-79 keV w...

Modelling hard and soft states of Cygnus X-1 with propagating mass accretion rate fluctuations

Science.gov (United States)

Rapisarda, S.; Ingram, A.; van der Klis, M.

2017-12-01

We present a timing analysis of three Rossi X-ray Timing Explorer observations of the black hole binary Cygnus X-1 with the propagating mass accretion rate fluctuations model PROPFLUC. The model simultaneously predicts power spectra, time lags and coherence of the variability as a function of energy. The observations cover the soft and hard states of the source, and the transition between the two. We find good agreement between model predictions and data in the hard and soft states. Our analysis suggests that in the soft state the fluctuations propagate in an optically thin hot flow extending up to large radii above and below a stable optically thick disc. In the hard state, our results are consistent with a truncated disc geometry, where the hot flow extends radially inside the inner radius of the disc. In the transition from soft to hard state, the characteristics of the rapid variability are too complex to be successfully described with PROPFLUC. The surface density profile of the hot flow predicted by our model and the lack of quasi-periodic oscillations in the soft and hard states suggest that the spin of the black hole is aligned with the inner accretion disc and therefore probably with the rotational axis of the binary system.

Distributed seeding for narrow-line width hard x-ray free-electron lasers

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Anisimov, Petr Mikhaylovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Buechler, Cynthia Eileen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lewellen, IV, John W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Marksteiner, Quinn R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-09-09

We describe a new FEL line-narrowing technique called distributed seeding (DS), using Si(111) Bragg crystal monochromators to enhance the spectral brightness of the MaRIE hard X-ray freeelectron laser. DS differs from self-seeding in three important aspects. First, DS relies on spectral filtering of the radiation at multiple locations along the undulator, with a monochromator located every few power gain lengths. Second, DS performs filtering early in the exponential gain region before SASE spikes start to appear in the radiation longitudinal profile. Third, DS provides the option to select a wavelength longer than the peak of the SASE gain curve, which leads to improved spectral contrast of the seeded FEL over the SASE background. Timedependent Genesis simulations show the power-vs-z growth curves for DS exhibit behaviors of a seeded FEL amplifier, such as exponential growth region immediately after the filters. Of the seeding approaches considered, the two-stage DS spectra produce the highest contrast of seeded FEL over the SASE background and that the three-stage DS provides the narrowest linewidth with a relative spectral FWHM of 8 X 10^-5 .

X-Ray pictures of the developmental anomalis of the hard dental tissue

International Nuclear Information System (INIS)

Cecetkova, A.; Ondrasovicova, J.

2008-01-01

Dental anomalies are rare lessions of the hard dental tissue. They are as symptoms varies of the syndromes. They are as follow: hyperdoncia, hypodoncia, oligodoncia, anodoncia, mesiodens, macrodoncia and microdoncia. All of the above anomalis are detected by X-ray diagnostics ( intraoral and extra-oral radiography ). (authors)

LIFTING THE VEIL ON OBSCURED ACCRETION: ACTIVE GALACTIC NUCLEI NUMBER COUNTS AND SURVEY STRATEGIES FOR IMAGING HARD X-RAY MISSIONS

International Nuclear Information System (INIS)

Ballantyne, D. R.; Draper, A. R.; Madsen, K. K.; Rigby, J. R.; Treister, E.

2011-01-01

Finding and characterizing the population of active galactic nuclei (AGNs) that produces the X-ray background (XRB) is necessary to connect the history of accretion to observations of galaxy evolution at longer wavelengths. The year 2012 will see the deployment of the first hard X-ray imaging telescope which, through deep extragalactic surveys, will be able to measure the AGN population at the energies where the XRB peaks (∼20-30 keV). Here, we present predictions of AGN number counts in three hard X-ray bandpasses: 6-10 keV, 10-30 keV, and 30-60 keV. Separate predictions are presented for the number counts of Compton thick AGNs, the most heavily obscured active galaxies. The number counts are calculated for five different models of the XRB that differ in the assumed hard X-ray luminosity function, the evolution of the Compton thick AGNs, and the underlying AGN spectral model. The majority of the hard X-ray number counts will be Compton thin AGNs, but there is a greater than tenfold increase in the Compton thick number counts from the 6-10 keV to the 10-30 keV band. The Compton thick population shows enough variation that a hard X-ray number counts measurement will constrain the models. The computed number counts are used to consider various survey strategies for the NuSTAR mission, assuming a total exposure time of 6.2 Ms. We find that multiple surveys will allow a measurement of Compton thick evolution. The predictions presented here should be useful for all future imaging hard X-ray missions.

Reconnection, Particle Acceleration, and Hard X-ray Emission in Eruptive Solar Flares

Science.gov (United States)

Martens, Petrus C.

1998-11-01

The frequent occurrence of Hard X-ray emission from the top of flaring loops was one of the discoveries by the Hard X-ray telescope on board the Japanese Yohkoh satellite. I will show how the combined effect of magnetic field convergence and pitch- angle scattering of non-thermal electrons injected at the top of the loop results in the generation of looptop sources with properties akin to those observed by Yohkoh. In addition it is shown that the injection of proton beams in the loop legs, expected from theory, reproduces the observed high temperature ``ridges" in the loop legs by mirroring and energy loss through collisions. I will interpret these numerical results as supporting the now widely accepted model of an erupting magnetic flux tube generating a reconnecting current sheet in its wake, where most of the energy release takes place. The strong similarity with the reconnection observed in the MRX experiment in Princeton will be analyzed in detail.

Rattling of Ba-atoms in Ba8ZnxGe43-5x/8([]3-3x/8)

International Nuclear Information System (INIS)

Melnychenko, N.; Grytsiv, A.; Rotter, M.; Rogl, P.; Devishvili, A.

2006-01-01

Full text: In order to improve the figure of merit of thermoelectric materials, one of the key parameters to be minimized is the lattice thermal conductivity. It is thus essential for the design of new thermoelectric materials to understand the lattice dynamics, especially the scattering mechanism of low energy phonons. The present paper describes formation, phase relations at subsolidus temperatures as well as at 800 o C, crystal chemistry and physical properties of a series of ternary clathrates as part of the solid solution, Ba 8 Zn x (Ge 43-5x/8[]3-3x/8 ), deriving from binary Ba 8 Ge 43 []3 with a solubility limit of 8 Zn per formula unit at 800 o C. Structural investigations in all cases confirm cubic primitive symmetry with a lattice parameter a ∼ 1.1 nm consistent with the space group type Pm-3n. Studies of transport coefficients evidence electrons as the majority charge carriers in the systems. Thermal conductivity exhibits a pronounced low temperature maximum, dominated by the lattice contribution, while at higher temperatures the electronic part gains weight. Inelastic neutron scattering experiments are used to study the phonon spectrum for Ba 8 Zn 8 Ge 38 . (author)

Measurement of preheat in aluminium target in indirect drive using the SGIII prototype facilities

International Nuclear Information System (INIS)

Zhang, C; Zheng, J; Wang, Z B; Liu, H; Peng, X S; Wang, F; Ding, Y K

2016-01-01

The velocity interferometer system for any reflector (VISAR) is used to demonstrate preheat effect in aluminium in indirect drive. The rear surface motion prior to shock front was observed and compared with a multi-group calculation. By properly adjusting the hard x-ray portion of the radiation source, the calculated rear surface motion fits well with the experimental results, which gives us confidence to predict the preheated temperature of the sample by hard x-rays. Further, the effect of hohlraum geometry is compared and discussed experimentally. The result suggests gas-filled hohlraum or hohlraum with low Z substrates should be considered to further reduce preheating. (paper)

A novel synthesis of polymeric CO via useful hard X-ray photochemistry

Directory of Open Access Journals (Sweden)

Michael Pravica

2016-12-01

Full Text Available We report on the synchrotron hard X-ray-induced decomposition of strontium oxalate (SrC2O4 pressurized to 7 GPa inside a diamond anvil cell (DAC. After some 4 h of irradiation in a white X-ray synchrotron beam, a dark reddish/brown region formed in the area of irradiation which was surrounded by a yellowish brown remainder in the rest of the sample. Upon depressurization of the sample to ambient conditions, the reacted/decomposed sample was recoverable as a dark brown/red and yellow waxy solid. Synchrotron infrared spectroscopy confirmed the strong presence of CO2 even under ambient conditions with the sample exposed to air and other strongly absorbing regions, suggesting that the sample may likely be polymerized CO (in part with dispersed CO2 and SrO trapped within the polymer. These results will have significant implications in the ability to readily produce and trap CO2 in situ via irradiation of a simple powder for useful hard X-ray photochemistry and in the ability to easily manufacture polymeric CO (via loading of powders in a DAC or high volume press without the need for the dangerous and complex loading of toxic CO. A novel means of X-ray-induced polymerization under extreme conditions has also been demonstrated.

kHz femtosecond laser-plasma hard X-ray and fast ion source

International Nuclear Information System (INIS)

Thoss, A.; Korn, G.; Stiel, H.; Voigt, U.; Elsaesser, T.; Richardson, M.C.; Siders, C.W.; Faubel, M.

2002-01-01

We describe the first demonstration of a new stable, kHz femtosecond laser-plasma source of hard x-ray continuum and K α emission using a thin liquid metallic jet target. kHz femtosecond x-ray sources will find many applications in time-resolved x-ray diffraction and microscopy studies. As high intensity lasers become more compact and operate at increasingly high repetition-rates, they require a target configuration that is both repeatable from shot-to-shot and is debris-free. We have solved this requirement with the use of a fine (10-30 μm diameter) liquid metal jet target that provides a pristine, unperturbed filament surface at rates >100 kHz. A number of liquid metal targets are considered. We will show hard x-ray spectra recorded from liquid Ga targets that show the generation of the 9.3 keV and 10.3 keV, K α and K β lines superimposed on a multi-keV Bremsstrahlung continuum. This source was generated by a 50fs duration, 1 kHz, 2W, high intensity Ti:Sapphire laser. We will discuss the extension of this source to higher powers and higher repetition rates, providing harder x-ray emission, with the incorporation of pulse-shaping and other techniques to enhance the x-ray conversion efficiency. Using the same liquid target technology, we have also demonstrated the generation of forward-going sub-MeV protons from a 10 μm liquid water target at 1 kHz repetition rates. kHz sources of high energy ions will find many applications in time-resolved particle interaction studies, as well as lead to the efficient generation of short-lived isotopes for use in nuclear medicine and other applications. The protons were detected with CR-39 track detectors both in the forward and backward directions up to energies of ∼500 keV. As the intensity of compact high repetition-rate lasers sources increase, we can expect improvements in the energy, conversion efficiency and directionality to occur. The impact of these developments on a number of fields will be discussed. As compact

THE SWIFT/BAT HARD X-RAY TRANSIENT MONITOR

Energy Technology Data Exchange (ETDEWEB)

Krimm, H. A.; Holland, S. T.; Corbet, R. H. D.; Pearlman, A. B.; Baumgartner, W. H.; Cummings, J. R. [Center for Research and Exploration in Space Science and Technology (CRESST) and NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Romano, P. [INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica, Via U. La Malfa 153, I-90146 Palermo (Italy); Kennea, J. A. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Bloom, J. S. [Department of Astronomy, University of California, Berkeley, Berkeley, CA 94720-3411 (United States); Barthelmy, S. D.; Gehrels, N.; Lien, A. Y.; Markwardt, C. B.; Ukwatta, T. N. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Palmer, D. M. [Los Alamos National Laboratory, B244, Los Alamos, NM 87545 (United States); Sakamoto, T. [Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara-shi, Kanagawa 252-5258 (Japan); Stamatikos, M. [Department of Physics and Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States)

2013-11-01

The Swift/Burst Alert Telescope (BAT) hard X-ray transient monitor provides near real-time coverage of the X-ray sky in the energy range 15-50 keV. The BAT observes 88% of the sky each day with a detection sensitivity of 5.3 mCrab for a full-day observation and a time resolution as fine as 64 s. The three main purposes of the monitor are (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the flux of known X-ray sources, and (3) the generation of light curves of more than 900 sources spanning over eight years. The primary interface for the BAT transient monitor is a public Web site. Between 2005 February 12 and 2013 April 30, 245 sources have been detected in the monitor, 146 of them persistent and 99 detected only in outburst. Among these sources, 17 were previously unknown and were discovered in the transient monitor. In this paper, we discuss the methodology and the data processing and filtering for the BAT transient monitor and review its sensitivity and exposure. We provide a summary of the source detections and classify them according to the variability of their light curves. Finally, we review all new BAT monitor discoveries. For the new sources that are previously unpublished, we present basic data analysis and interpretations.

The Swift/BAT Hard X-ray Transient Monitor

Science.gov (United States)

Krimm, H. A.; Holland, S. T.; Corbet, R.H.D.; Pearlman, A. B.; Romano, P.; Kennea, J. A.; Bloom, J. S.; Barthelmy, S. D.; Baumgartner, W. H.; Cummings, J. R.;

The Swift-BAT Hard X-Ray Transient Monitor

Science.gov (United States)

Krimm, H. A.; Holland, S. T.; Corbet, R. H. D.; Pearlman, A. B.; Romano, P.; Kennea, J. A.; Bloom, J. S.; Barthelmy, S. D.; Baumgartner, W. H.; Cummings, J. R.;

THE SWIFT/BAT HARD X-RAY TRANSIENT MONITOR

International Nuclear Information System (INIS)

Krimm, H. A.; Holland, S. T.; Corbet, R. H. D.; Pearlman, A. B.; Baumgartner, W. H.; Cummings, J. R.; Romano, P.; Kennea, J. A.; Bloom, J. S.; Barthelmy, S. D.; Gehrels, N.; Lien, A. Y.; Markwardt, C. B.; Ukwatta, T. N.; Palmer, D. M.; Sakamoto, T.; Stamatikos, M.

2013-01-01

The Swift/Burst Alert Telescope (BAT) hard X-ray transient monitor provides near real-time coverage of the X-ray sky in the energy range 15-50 keV. The BAT observes 88% of the sky each day with a detection sensitivity of 5.3 mCrab for a full-day observation and a time resolution as fine as 64 s. The three main purposes of the monitor are (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the flux of known X-ray sources, and (3) the generation of light curves of more than 900 sources spanning over eight years. The primary interface for the BAT transient monitor is a public Web site. Between 2005 February 12 and 2013 April 30, 245 sources have been detected in the monitor, 146 of them persistent and 99 detected only in outburst. Among these sources, 17 were previously unknown and were discovered in the transient monitor. In this paper, we discuss the methodology and the data processing and filtering for the BAT transient monitor and review its sensitivity and exposure. We provide a summary of the source detections and classify them according to the variability of their light curves. Finally, we review all new BAT monitor discoveries. For the new sources that are previously unpublished, we present basic data analysis and interpretations

Submicron hard X-ray fluorescence imaging of synthetic elements.

Science.gov (United States)

Jensen, Mark P; Aryal, Baikuntha P; Gorman-Lewis, Drew; Paunesku, Tatjana; Lai, Barry; Vogt, Stefan; Woloschak, Gayle E

2012-04-13

Synchrotron-based X-ray fluorescence microscopy (XFM) using hard X-rays focused into sub-micron spots is a powerful technique for elemental quantification and mapping, as well as microspectroscopic measurements such as μ-XANES (X-ray absorption near edge structure). We have used XFM to image and simultaneously quantify the transuranic element plutonium at the L(3) or L(2)-edge as well as Th and lighter biologically essential elements in individual rat pheochromocytoma (PC12) cells after exposure to the long-lived plutonium isotope (242)Pu. Elemental maps demonstrate that plutonium localizes principally in the cytoplasm of the cells and avoids the cell nucleus, which is marked by the highest concentrations of phosphorus and zinc, under the conditions of our experiments. The minimum detection limit under typical acquisition conditions with an incident X-ray energy of 18 keV for an average 202 μm(2) cell is 1.4 fg Pu or 2.9×10(-20) moles Pu μm(-2), which is similar to the detection limit of K-edge XFM of transition metals at 10 keV. Copper electron microscopy grids were used to avoid interference from gold X-ray emissions, but traces of strontium present in naturally occurring calcium can still interfere with plutonium detection using its L(α) X-ray emission. Copyright © 2012 Elsevier B.V. All rights reserved.

A 1-D Study of the Ignition Space for Magnetic Indirect (X-ray) Drive Targets

Energy Technology Data Exchange (ETDEWEB)

Cobble, James Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinars, Daniel Brian [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-06-02

The ICF program today is investigating three approaches to achieving multi-MJ fusion yields and ignition: (1) laser indirect (x-ray) drive on the National Ignition Facility (NIF), (2) laser direct drive (primarily on the Omega laser facility at the University of Rochester), and (3) magnetic direct drive on the Z pulsed power facility. In this white paper we briefly consider a fourth approach, magnetic indirect drive, in which pulsedpower- driven x-ray sources are used in place of laser driven sources. We first look at some of the x-ray sources studied on Z prior to 2007 before the pulsed power ICF program shifted to magnetic direct drive. We then show results from a series of 1D Helios calculations of double-shell capsules that suggest that these sources, scaled to higher temperatures, could be a promising path to achieving multi-MJ fusion yields and ignition. We advocate here that more detailed design calculations with widely accepted 2D/3D ICF codes should be conducted for a better assessment of the prospects.

Optimising hard X-ray generation from laser-produced plasmas

International Nuclear Information System (INIS)

Lindheimer, C.

1995-04-01

The aim of this work is to increase the X-ray yield for a laser produced plasma by optimising the focusing conditions and temporal shape of the laser pulses. The focusing conditions are improved by introducing a control system that secures the laser target surface to exact focus within a range of a few micrometers, allowing continuously high laser intensity for plasma generation. The temporal shape of the laser pulses is changed by introducing a saturable absorber in the laser beam. The laser produces a substantial pre-pulse that heats and expands the target material prior to main pulse arrival. The saturable absorber can increase the main pulse/pre-pulse ratio of the laser pulse up to four orders of magnitude and consequently reduce expansion of the target material before the main pulse. The belief is that an increase in target density at the time of main pulse arrival will change the energy distribution of the X-rays, towards a more efficient X-ray production in the hard X-ray region. This report and the work connected to it, includes the preliminary measurements and results for these improvements. 17 refs

AN OSCILLATOR CONFIGURATION FOR FULL REALIZATION OF HARD X-RAY FREE ELECTRON LASER*

Energy Technology Data Exchange (ETDEWEB)

Kim, K.-J.; Kolodziej, T.; Lindberg, R. R.; Shu, D.; Shvyd' ko, Y.; Stoupin, S.; Maxwell, T.J.; Ding, Y.; Fawley, W. M.; Hastings, J.; Huang, Z; Krzywinski, J.; Marcus, G.; Qin, Weilun; Medvedev, N.; Zemella, J.; Blank, V.; Terentyev, S.

2017-06-01

An x-ray free electron laser oscillator (XFELO) is feasible by employing an X-ray cavity with Bragg mirrors such as diamond crystals. An XFELO at the 5th harmonic frequency may be implemented at the LCLS II using its 4 GeV superconducting linac, producing stable, fully coherent, high-spectral-purity hard x-rays. In addition, its output can be a coherent seed to the LCLS amplifier for stable, high-power, femto-second x-ray pulses. We summarize the recent progress in various R&D efforts addressing critical issues for realizing an XFELO at LCLS II.

CO-ANALYSIS OF SOLAR MICROWAVE AND HARD X-RAY SPECTRAL EVOLUTIONS. II. IN THREE SOURCES OF A FLARING LOOP

International Nuclear Information System (INIS)

Huang Guangli; Li Jianping

2011-01-01

Based on the spatially resolvable data of the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and Nobeyama Radio Heliograph (NoRH), co-analysis of solar hard X-ray and microwave spectral evolution is performed in three separate sources located in one looptop (LT) and two footpoints (FPs) of a huge flaring loop in the 2003 October 24 flare. The RHESSI image spectral evolution in 10-100 keV is always fitted by the well-known soft-hard-soft (SHS) pattern in the three sources. When the total energy is divided into four intervals similar to the Yohkoh/Hard X-ray Telescope, i.e., 12.5-32.5 keV, 32.5-52.5 keV, 52.5-72.5 keV, and 72.5-97.5 keV, the SHS pattern in lower energies is converted gradually to the hard-soft-hard (HSH) pattern in higher energies in all three sources. However, the break energy in the LT and the northeast FP (∼32.5 keV) is evidently smaller than that in the southwest FP (∼72.5 keV). Regarding microwave spectral evolution of the NoRH data, the well-known soft-hard-harder pattern appeared in the southwest FP, while the HSH pattern coexisted in the LT and the northeast FP. The different features of the hard X-ray and microwave spectral evolutions in the three sources may be explained by the loop-loop interaction with another huge loop in the LT and with a compact loop in the northeast FP, where the trapping effect is much stronger than that in the southwest FP. The comparison between the LT and FP spectral indices suggests that the radiation mechanism of X-rays may be quite different in different energy intervals and sources. The calculated electron spectral indices from the predicted mechanisms of X-rays gradually become closer to those from the microwave data with increasing X-ray energies.

Mac OS X Forensics

Science.gov (United States)

Craiger, Philip; Burke, Paul

This paper describes procedures for conducting forensic examinations of Apple Macs running Mac OS X. The target disk mode is used to create a forensic duplicate of a Mac hard drive and preview it. Procedures are discussed for recovering evidence from allocated space, unallocated space, slack space and virtual memory. Furthermore, procedures are described for recovering trace evidence from Mac OS X default email, web browser and instant messaging applications, as well as evidence pertaining to commands executed from a terminal.

Development of thermally formed glass optics for astronomical hard X-ray telescopes

DEFF Research Database (Denmark)

Craig, W.W.; Hailey, C.J.; Jimenez-Garate, M.

2000-01-01

The next major observational advance in hard X-ray/soft gamma-ray astrophysics will come with the implementation of telescopes capable of focusing 10-200 keV radiation. Focusing allows high signal-to-noise imaging and spectroscopic observations of many sources in this band for the first time...

Hard X-ray/soft gamma-ray telescope designs for future astrophysics missions

DEFF Research Database (Denmark)

Ferreira, Desiree Della Monica; Christensen, Finn Erland; Pivovaroff, Michael J.

2013-01-01

We present several concept designs of hard X-ray/soft λ-ray focusing telescopes for future astrophysics missions. The designs are based on depth graded multilayer coatings. These have been successfully employed on the NuSTAR mission for energies up to 80 keV. Recent advances in demonstrating...

Hard X-ray photoemission spectroscopy of transition-metal oxide thin films and interfaces

International Nuclear Information System (INIS)

Wadati, H.; Fujimori, A.

2013-01-01

Highlights: •Photoemission spectroscopy is a powerful technique to study the electronic structures of transition-metal oxides. •Hard X-ray photoemission spectroscopy (HXPES) is a new type of photoemission spectroscopy which can probe bulk states. •HXPES is very suitable for studying oxide thin films such as the composition dependence and the film thickness dependence. -- Abstract: Photoemission spectroscopy is a powerful experimental technique to study the electronic structures of solids, especially of transition-metal oxides. Recently, hard X-ray photoemission spectroscopy (HXPES) has emerged as a more relevant experimental technique to obtain clear information about bulk states. Here, we describe how HXPES can be conveniently applied to study the interesting subjects on oxide thin films such as the composition dependence and the film thickness dependence of the electronic structures and the interfacial electronic structure of multilayers

INTEGRAL SPI Observations of Cygnus X-1 in the Soft State: What about the Jet Contribution in Hard X-Rays?

Science.gov (United States)

Jourdain, E.; Roques, J. P.; Chauvin, M.

2014-07-01

During the first 7 yr of the INTEGRAL mission (2003-2009), Cyg X-1 has essentially been detected in its hard state (HS), with some incursions in intermediate HSs. This long, spectrally stable period allowed in particular the measurement of the polarization of the high-energy component that has long been observed above 200 keV in this peculiar object. This result strongly suggests that here we see the contribution of the jet, known to emit a strong synchrotron radio emission. In 2010 June, Cyg X-1 underwent a completed transition toward a soft state (SS). It gave us the unique opportunity to study in detail the corona emission in this spectral state, and to investigate in particular the behavior of the jet contribution. Indeed, during the SS, the hard X-ray emission decreases drastically, with its maximum energy shifted toward lower energy and its flux divided by a factor of ~5-10. Interestingly, the radio emission follows a similar drop, supporting the correlation between the jet emission and the hard component, even though the flux is too low to quantify the polarization characteristics. Based on observations with INTEGRAL, an ESA project with instruments and science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Spain, and Switzerland), the Czech Republic and Poland with the participation of Russia and USA.

VLBI OBSERVATION OF MICROQUASAR CYG X-3 DURING AN X-RAY STATE TRANSITION FROM SOFT TO HARD IN THE 2007 MAY-JUNE FLARE

Energy Technology Data Exchange (ETDEWEB)

Kim, Jeong-Sook; Kim, Sang Joon [School of Space Science, Kyunghee University, Seocheon-dong, Giheung-si, Gyeonggi-do 446-701 (Korea, Republic of); Kim, Soon-Wook [Korea Astronomy and Space Science Institute, 776 Daedeokdaero, Yuseong, Daejeon 305-348 (Korea, Republic of); Kurayama, Tomoharu [Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima, Kagoshima 890-0065 (Japan); Honma, Mareki [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Sasao, Tetsuo, E-mail: evony@kasi.re.kr, E-mail: skim@kasi.re.kr [Yaeyama Star Club, Ookawa, Ishigaki, Okinawa 904-0022 (Japan)

2013-07-20

We present a radio observation of microquasar Cyg X-3 during an X-ray state transition from ultrasoft to hard state in the 2007 May-June flare using the VLBI Exploration of Radio Astrometry at 22 GHz. During the transition, a short-lived mini-flare of {approx}< 3 hr was detected prior to the major flare. In such a transition, a jet ejection is believed to occur, but there have been no direct observations to support it. An analysis of Gaussian fits to the observed visibility amplitudes shows a time variation of the source axis, or a structural change, during the mini-flare. Our model fits, together with other multiwavelength observations in the radio, soft, and hard X-rays, and the shock-in-jet models for other flaring activities at GHz wavebands, suggest a high possibility of synchrotron flares during the mini-flare, indicative of a predominant contribution from jet activity. Therefore, the mini-flare with an associated structural change is indicative of a jet ejection event in the state transition from ultrasoft to hard state.

Fast solar hard X-ray bursts and large scale coronal structures

International Nuclear Information System (INIS)

Simnett, G.M.

1982-01-01

The conditions at the Sun at the times corresponding to a selected set 22 fast impulsive hard X-ray bursts reported by Crannell et al. are examined. It is suggested that one of the bursts must arise from a precipitating beam of subrelativistic electrons; the source of the electrons is postulated to be in a region very remote from the X-ray site on the basis of type III and other radio data. The connection is via a coronal magnetic loop extending to approx.3 R/sub sun/ above the photosphere. The energy in the electron beam is estimated at 3 x 10 27 ergs. Intense soft X-ray and/or microwave radio storms at times corresponding to many of the impulsive X-ray bursts lead the conclusion that 14, and possibly 18, of the 22 bursts could have the same interpretation. The energy in such an electron beam could be important when considering the trigger phase of some flares

X-Rays from NGC 3256: High-Energy Emission in Starburst Galaxies and Their Contribution to the Cosmic X-Ray Background

International Nuclear Information System (INIS)

Moran, Edward C.; Lehnert, Matthew D.; Helfand, David J.

1999-01-01

The infrared-luminous galaxy NGC 3256 is a classic example of a merger-induced nuclear starburst system. We find here that it is the most X-ray-luminous star-forming galaxy yet detected (L 0.5-10keV =1.6x10 42 ergs s-1). Long-slit optical spectroscopy and a deep, high-resolution ROSAT X-ray image show that the starburst is driving a ''superwind'' which accounts for ∼20% of the observed soft X-ray emission. Analysis of X-ray spectral data from ASCA indicates this gas has a characteristic temperature of kT≅0.3 keV. Our model for the broadband X-ray emission of NGC 3256 contains two additional components: a warm thermal plasma (kT≅0.8 keV) associated with the central starburst, and a hard power-law component with an energy index of α X ≅0.7. We discuss the energy budget for the two thermal plasmas and find that the input of mechanical energy from the starburst is more than sufficient to sustain the observed level of emission. We also examine possible origins for the power-law component, concluding that neither a buried AGN nor the expected population of high-mass X-ray binaries can account for this emission. Inverse Compton scattering, involving the galaxy's copious flux of infrared photons and the relativistic electrons produced by supernovae, is likely to make a substantial contribution to the hard X-ray flux. Such a model is consistent with the observed radio and IR fluxes and the radio and X-ray spectral indices. We explore the role of X-ray-luminous starbursts in the production of the cosmic X-ray background radiation. The number counts and spectral index distribution of the faint radio source population, thought to be dominated by star-forming galaxies, suggest that a significant fraction of the hard X-ray background could arise from starbursts at moderate redshift. (c) (c) 1999. The American Astronomical Society

Behavior of hard X-ray emission in discharges with current disruptions in the DAMAVAND and TVD tokamaks

International Nuclear Information System (INIS)

Farshi, E.; Amrollahy, R.; Bortnikov, A.V.; Brevnov, N.N.; Gott, Yu.V.; Shurygin, V.A.

2001-01-01

Results are presented from studies of the behavior of hard X-ray emission in discharges with current disruptions in the DAMAVAND and TVD tokamaks. The current disruptions are caused by either an MHD instability or the instability related to the vertical displacement of the plasma column. Experiments were conducted at a fixed value of the safety factor at the plasma boundary (q a ≅ 2.3). Experimental data show that, during a disruption caused by an MHD instability, hard X-ray emission is suppressed by this instability if the amplitude of the magnetic field fluctuations exceeds a certain level. If the disruption is caused by the instability related to the vertical displacement of the plasma column, then hard X-ray emission is observed at the instant of disruption. The experimental results show that the physical processes resulting in the generation and suppression of runaway electron beams are almost identical in large and small tokamaks

Flight performance of an advanced CZT imaging detector in a balloon-borne wide-field hard X-ray telescope-ProtoEXIST1

Energy Technology Data Exchange (ETDEWEB)

Hong, J., E-mail: jaesub@head.cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Allen, B.; Grindlay, J. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Barthelemy, S.; Baker, R. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Garson, A.; Krawczynski, H. [Washington University in St. Louis and the McDonnell Center for the Space Sciences, St. Louis, MO 63130 (United States); Apple, J.; Cleveland, W.H. [NASA Marshall Space Flight Center and Universities Space Research Association, Huntsville, AL 35812 (United States)

2011-10-21

We successfully carried out the first high-altitude balloon flight of a wide-field hard X-ray coded-aperture telescope ProtoEXIST1, which was launched from the Columbia Scientific Balloon Facility at Ft. Sumner, New Mexico on October 9, 2009. ProtoEXIST1 is the first implementation of an advanced CdZnTe (CZT) imaging detector in our ongoing program to establish the technology required for next generation wide-field hard X-ray telescopes such as the High Energy Telescope (HET) in the Energetic X-ray Imaging Survey Telescope (EXIST). The CZT detector plane in ProtoEXIST1 consists of an 8x8 array of closely tiled 2 cmx2 cmx0.5 cm thick pixellated CZT crystals, each with 8x8 pixels, mounted on a set of readout electronics boards and covering a 256 cm{sup 2} active area with 2.5 mm pixels. A tungsten mask, mounted at 90 cm above the detector provides shadowgrams of X-ray sources in the 30-600 keV band for imaging, allowing a fully coded field of view of 9{sup o}x9{sup o} (and 19{sup o}x19{sup o} for 50% coding fraction) with an angular resolution of 20'. In order to reduce the background radiation, the detector is surrounded by semi-graded (Pb/Sn/Cu) passive shields on the four sides all the way to the mask. On the back side, a 26 cmx26 cmx2 cm CsI(Na) active shield provides signals to tag charged particle induced events as well as {>=}100keV background photons from below. The flight duration was only about 7.5 h due to strong winds (60 knots) at float altitude (38-39 km). Throughout the flight, the CZT detector performed excellently. The telescope observed Cyg X-1, a bright black hole binary system, for {approx}1h at the end of the flight. Despite a few problems with the pointing and aspect systems that caused the telescope to track about 6.4{sup o} off the target, the analysis of the Cyg X-1 data revealed an X-ray source at 7.2{sigma} in the 30-100 keV energy band at the expected location from the optical images taken by the onboard daytime star camera. The

Microstructure and mechanical properties of hard zone in friction stir welded X80 pipeline steel relative to different heat input

Energy Technology Data Exchange (ETDEWEB)

Aydin, Hakan, E-mail: hakanay@uludag.edu.tr [Engineering and Architecture Faculty, Mechanical Engineering Department, Uludag University, 16059 Gorukle-Bursa (Turkey); Nelson, Tracy W. [Mechanical Engineering Department, Brigham Young University, 435 CTB, Provo, UT 84602 (United States)

2013-12-01

The study was conducted to investigate the microstructure and mechanical properties of the hard zone in friction stir welded X80 pipeline steel at different heat inputs. Microstructural analysis of the welds was carried out using optical microscopy, transmission electron microscopy, and microhardness. Heat input during friction stir welding process had a significant influence on the microstructure and mechanical properties in the hard zone along the advancing side of the weld nugget. Based on the results, the linear relationships between heat input and post-weld microstructures and mechanical properties in the hard zone of friction stir welded X80 steels were established. It can be concluded that with decrease in heat input the bainitic structure in the hard zone becomes finer and so hard zone strength increases.

Microstructure and mechanical properties of hard zone in friction stir welded X80 pipeline steel relative to different heat input

International Nuclear Information System (INIS)

Aydin, Hakan; Nelson, Tracy W.

2013-01-01

The study was conducted to investigate the microstructure and mechanical properties of the hard zone in friction stir welded X80 pipeline steel at different heat inputs. Microstructural analysis of the welds was carried out using optical microscopy, transmission electron microscopy, and microhardness. Heat input during friction stir welding process had a significant influence on the microstructure and mechanical properties in the hard zone along the advancing side of the weld nugget. Based on the results, the linear relationships between heat input and post-weld microstructures and mechanical properties in the hard zone of friction stir welded X80 steels were established. It can be concluded that with decrease in heat input the bainitic structure in the hard zone becomes finer and so hard zone strength increases

Accretion Properties of a Sample of Hard X-Ray (<60 keV) Selected Seyfert 1 Galaxies

Science.gov (United States)

Wang, J.; Mao, Y. F.; Wei, J. Y.

2009-02-01

We examine the accretion properties in a sample of 42 hard (3-60 keV) X-ray selected nearby broad-line active galactic nuclei (AGNs). The energy range in the sample is harder than that usually used in similar previous studies. These AGNs are mainly complied from the RXTE All Sky Survey, and complemented by the released INTEGRAL AGN catalog. The black hole masses, bolometric luminosities of AGN, and Eddington ratios are derived from their optical spectra in terms of the broad Hβ emission line. The tight correlation between the hard X-ray (3-20 keV) and bolometric/line luminosity is well identified in our sample. Also identified is a strong inverse Baldwin relationship of the Hβ emission line. In addition, all of these hard X-ray AGNs are biased toward luminous objects with a high Eddington ratio (mostly between 0.01 and 0.1) and a low column density (Simbol-X, and NeXT. Finally, the correlation between RFe (= optical Fe II/Hβ) and disk temperature as assessed by T vprop (L/L Edd)M -1 BH leads us to suggest that the strength of the Fe II emission is mainly determined by the shape of the ionizing spectrum.

Moessbauer studies of the LiAl sub(5-x) Fe sub(x) O8 and LiGa sub(5-x) Fe sub(x) O8 systems

International Nuclear Information System (INIS)

Barthem, V.M.T.S.; Maria Neto, J.; Souza Barros, F. de

1982-01-01

Comparative Moessbauer studies of the LiGa sub(5-x) Fe sub(x) O 8 and LiAl sub(5-x) Fe sub(x) O 8 systems are shown. The characteristics of the Moessbauer spectra, obtained with LiGa 5 O 8 samples with 0,1% of Fe 3+ , differ drastically from that observed with LiAl 5 O 8 with the same three-valent iron concentration. All these differences are related to the more covalent character of the gallium-oxygen binding, when compared with the aluminium-oxygen one. (L.C.) [pt

A SUZAKU SEARCH FOR NONTHERMAL EMISSION AT HARD X-RAY ENERGIES IN THE COMA CLUSTER

International Nuclear Information System (INIS)

Wik, Daniel R.; Sarazin, Craig L.; Finoguenov, Alexis; Matsushita, Kyoko; Nakazawa, Kazuhiro; Clarke, Tracy E.

2009-01-01

The brightest cluster radio halo known resides in the Coma cluster of galaxies. The relativistic electrons producing this diffuse synchrotron emission should also produce inverse Compton emission that becomes competitive with thermal emission from the intracluster medium (ICM) at hard X-ray energies. Thus far, claimed detections of this emission in Coma are controversial. We present a Suzaku HXD-PIN observation of the Coma cluster in order to nail down its nonthermal hard X-ray content. The contribution of thermal emission to the HXD-PIN spectrum is constrained by simultaneously fitting thermal and nonthermal models to it and a spatially equivalent spectrum derived from an XMM-Newton mosaic of the Coma field. We fail to find statistically significant evidence for nonthermal emission in the spectra which are better described by only a single- or multitemperature model for the ICM. Including systematic uncertainties, we derive a 90% upper limit on the flux of nonthermal emission of 6.0 x 10 -12 erg s -1 cm -2 (20-80 keV, for Γ = 2.0), which implies a lower limit on the cluster-averaged magnetic field of B>0.15 μG. Our flux upper limit is 2.5 times lower than the detected nonthermal flux from RXTE and BeppoSAX. However, if the nonthermal hard X-ray emission in Coma is more spatially extended than the observed radio halo, the Suzaku HXD-PIN may miss some fraction of the emission. A detailed investigation indicates that ∼50%-67% of the emission might go undetected, which could make our limit consistent with that of Rephaeli and Gruber and Fusco-Femiano et al. The thermal interpretation of the hard Coma spectrum is consistent with recent analyses of INTEGRAL and Swift data.

Characterization of temporal coherence of hard X-ray free-electron laser pulses with single-shot interferograms

Directory of Open Access Journals (Sweden)

Taito Osaka

2017-11-01

Full Text Available Temporal coherence is one of the most fundamental characteristics of light, connecting to spectral information through the Fourier transform relationship between time and frequency. Interferometers with a variable path-length difference (PLD between the two branches have widely been employed to characterize temporal coherence properties for broad spectral regimes. Hard X-ray interferometers reported previously, however, have strict limitations in their operational photon energies, due to the specific optical layouts utilized to satisfy the stringent requirement for extreme stability of the PLD at sub-ångström scales. The work presented here characterizes the temporal coherence of hard X-ray free-electron laser (XFEL pulses by capturing single-shot interferograms. Since the stability requirement is drastically relieved with this approach, it was possible to build a versatile hard X-ray interferometer composed of six separate optical elements to cover a wide photon energy range from 6.5 to 11.5 keV while providing a large variable delay time of up to 47 ps at 10 keV. A high visibility of up to 0.55 was observed at a photon energy of 10 keV. The visibility measurement as a function of time delay reveals a mean coherence time of 5.9 ± 0.7 fs, which agrees with that expected from the single-shot spectral information. This is the first result of characterizing the temporal coherence of XFEL pulses in the hard X-ray regime and is an important milestone towards ultra-high energy resolutions at micro-electronvolt levels in time-domain X-ray spectroscopy, which will open up new opportunities for revealing dynamic properties in diverse systems on timescales from femtoseconds to nanoseconds, associated with fluctuations from ångström to nanometre spatial scales.

First hohlraum drive studies on the National Ignition Facility

International Nuclear Information System (INIS)

Dewald, E.L.; Landen, O.L.; Suter, L.J.; Schein, J.; Holder, J.; Campbell, K.; Glenzer, S.H.; McDonald, J.W.; Niemann, C.; Mackinnon, A.J.; Schneider, M.S.; Haynam, C.; Hinkel, D.; Hammel, B.A.

2006-01-01

The first hohlraum experiments on the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Nucl. Fusion 44, 228 (2004)] using the first four laser beams have activated the indirect-drive experimental capabilities and tested radiation temperature limits imposed by hohlraum plasma filling. Vacuum hohlraums have been irradiated with laser powers up to 9 TW, 1 to 9 ns long square pulses and energies of up to 17 kJ to study the hohlraum radiation temperature scaling with the laser power and hohlraum size, and to make contact with hohlraum experiments performed previously at other laser facilities. Furthermore, for a variety of hohlraum sizes and pulse lengths, the measured x-ray flux shows signatures of plasma filling that coincide with hard x-ray emission from plasma streaming out of the hohlraum. These observations agree with hydrodynamic simulations and with analytical modeling that includes hydrodynamic and coronal radiative losses. The modeling predicts radiation temperature limits on full NIF (1.8 MJ) that are significantly greater than required for ignition hohlraums

Investigation of pulse shape analyzers for phoswich detectors in space-borne hard X-ray experiments

Energy Technology Data Exchange (ETDEWEB)

Bleeker, J A.M.; Overtoom, J M [Huygens Lab., Leiden (Netherlands). Cosmic Ray Working Group

1979-12-01

A low-background telescope for hard X-ray astronomy (15-250 keV), comprising arrays of NaI(Tl)/CsI(Na) phoswiches as photon collectors, was recently developed. The background rejection efficiency of such a telescope, and hence the minimum source in a given time, critically depends on the performance of the phoswich pulse shape analyzer (PSA) in a space radiation environment. Results from theoretical and experimental work on analyzer configurations based on zero-crossing detection are presented. This led to the selection of an optimum configuration for space application. The in-situ performance of this analyzer was evaluated in a balloon-borne hard X-ray experiment, showing excellent discrimination efficiency throughout the entire energy regime.

On hard X-ray spectra of accreting neutron stars

International Nuclear Information System (INIS)

Zheleznyakov, V.V.

1982-01-01

Formation of the spectra of X-ray pulsars and gamma bursters is investigated. Interpretation of a hard X-ray spectrum of pulsars containing cyclotron lines is feasible on the basis of an isothermal model of a polar spot heated due to acccretion to a neutron star. It has been ascertained that in the regions responsible for the formation of continuum radiation and lines the mode polarization is determined by a magnetized vacuum rather than by a plasma. Bearing this in mind, the influence of the magnetic field of a star on the wide wings of the cyclotron line and on its depth is discussed. The part played by the accreting column in the case of strong accretion (approx. equal to 10 19 el cm -3 ) needed for long sustaining of the high level of X-rays from a neutron star-pulsar is studied. There occur the gaps in spectrum at frequencies close to the electron gyro-frequency and its harmonics due to the screening of the hot spot by the opaque gyro-resonant layer located within the accreting column. These gaps ensure the formation of cyclotron lines in absorption irrespective of the presence of such lines in the X-ray spectrum of a polar hot spot. (orig./WL)

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

International Nuclear Information System (INIS)

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

1999-01-01

Hohlraums (measuring 6-mm in diameter by 7-mm in height) have been heated by x-rays from a z-pinch. Over measured x-ray input powers P of 0.7 to 13 TW, the hohlraum radiation temperature T increases from approximately55 to approximately130 eV, and is in agreement with the Planckian relation P-T 4 . The results suggest that indirect-drive ICF studies involving NIF relevant pulse shapes and <2-mm diameter capsules can he studied using this arrangement

Chemoreception drives plastic consumption in a hard coral.

Science.gov (United States)

Allen, Austin S; Seymour, Alexander C; Rittschof, Daniel

2017-11-15

The drivers behind microplastic (up to 5mm in diameter) consumption by animals are uncertain and impacts on foundational species are poorly understood. We investigated consumption of weathered, unfouled, biofouled, pre-production and microbe-free National Institute of Standards plastic by a scleractinian coral that relies on chemosensory cues for feeding. Experiment one found that corals ingested many plastic types while mostly ignoring organic-free sand, suggesting that plastic contains phagostimulents. Experiment two found that corals ingested more plastic that wasn't covered in a microbial biofilm than plastics that were biofilmed. Additionally, corals retained ~8% of ingested plastic for 24h or more and retained particles appeared stuck in corals, with consequences for energetics, pollutant toxicity and trophic transfer. The potential for chemoreception to drive plastic consumption in marine taxa has implications for conservation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hard X-ray bremsstrahlung production in solar flares by high-energy proton beams

Science.gov (United States)

Emslie, A. G.; Brown, J. C.

1985-01-01

The possibility that solar hard X-ray bremsstrahlung is produced by acceleration of stationary electrons by fast-moving protons, rather than vice versa, as commonly assumed, was investigated. It was found that a beam of protons which involves 1836 times fewer particles, each having an energy 1836 times greater than that of the electrons in the equivalent electron beam model, has exactly the same bremsstrahlung yield for a given target, i.e., the mechanism has an energetic efficiency equal to that of conventional bremsstrahlung models. Allowance for the different degrees of target ionization appropriate to the two models (for conventional flare geometries) makes the proton beam model more efficient than the electron beam model, by a factor of order three. The model places less stringent constraints than a conventional electron beam model on the flare energy release mechanism. It is also consistent with observed X-ray burst spectra, intensities, and directivities. The altitude distribution of hard X-rays predicted by the model agrees with observations only if nonvertical injection of the protons is assumed. The model is inconsistent with gamma-ray data in terms of conventional modeling.

Investigation of biomedical inner microstructures with hard X-ray phase-contrast imaging

Energy Technology Data Exchange (ETDEWEB)

Shu Hang [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); Graduate University of the Chinese Academy of Sciences, 100864 Beijing (China); Zhu Peiping [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); Chen Bo [Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Liu Bo; Yin Hongxia [Capital University of Medical Sciences, 100054 Beijing (China); Li Enrong [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); Graduate University of the Chinese Academy of Sciences, 100864 Beijing (China); Liu Yijin [Department of Physics, University of Science and Technology of China, Hefei 230026 (China); Wang Junyue [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); Graduate University of the Chinese Academy of Sciences, 100864 Beijing (China); Yuan Qingxi; Huang Wanxia; Fang Shouxian [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); Wu Ziyu [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, 100049 Beijing (China); National Center for NanoScience and Technology, 100080 Beijing (China)], E-mail: wuzy@ihep.ac.cn

2007-09-21

Hard X-ray Phase-Contrast Imaging (HX-PCI) is a new and valuable method that may provide information of the inner parts of an opaque object. Previous reports demonstrated its applicability in soft and hard tissue imaging. Here we provide further evidence for improved image quality and the effective capability to distinguish inner microstructures in real biomedical systems such as cochlea. Experiments performed both at the 4W1A beamline of the Beijing Synchrotron Radiation Facility (BSRF) and at the Taiwan National Synchrotron Radiation Research Center (NSRRC) clearly show details of samples' inner microstructure with a resolution of a few microns. The improved spatial resolution is a relevant achievement for future improved understanding and clinical trials.

Atomic physics with hard X-rays from high brilliance synchrotron light sources

International Nuclear Information System (INIS)

Southworth, S.; Gemmell, D.

1996-08-01

A century after the discovery of x rays, the experimental capability for studying atomic structure and dynamics with hard, bright synchrotron radiation is increasing remarkably. Tempting opportunities arise for experiments on many-body effects, aspects of fundamental photon-atom interaction processes, and relativistic and quantum-electrodynamic phenomena. Some of these possibilities are surveyed in general terms

Atomic physics with hard X-rays from high brilliance synchrotron light sources

Energy Technology Data Exchange (ETDEWEB)

Southworth, S.; Gemmell, D.

1996-08-01

A century after the discovery of x rays, the experimental capability for studying atomic structure and dynamics with hard, bright synchrotron radiation is increasing remarkably. Tempting opportunities arise for experiments on many-body effects, aspects of fundamental photon-atom interaction processes, and relativistic and quantum-electrodynamic phenomena. Some of these possibilities are surveyed in general terms.

Hard-x-ray phase-imaging microscopy using the self-imaging phenomenon of a transmission grating

International Nuclear Information System (INIS)

Yashiro, Wataru; Harasse, Sebastien; Momose, Atsushi; Takeuchi, Akihisa; Suzuki, Yoshio

2010-01-01

We report on a hard-x-ray imaging microscope consisting of a lens, a sample, and a transmission grating. After the theoretical framework of self-imaging phenomenon by the grating in the system is presented, equations for the electric field on the image plane are derived for ideal and real lenses and an equation for the intensity on the image plane for partially coherent illumination is derived. The equations are simple and similar to those applying to a projection microscope consisting of a transmission grating except that there is no defocusing effect, regardless of whether the grating is in front of or behind the lens. This means that x-ray phase-imaging microscopy can be done without the defocusing effect. It is also shown that, by resolving the self-image on the image plane, high-sensitive x-ray phase-imaging microscopy can be attained without degradation in the spatial resolution due to diffraction by the grating. Experimental results obtained using partially coherent illumination from a synchrotron x-ray source confirm that hard-x-ray phase-imaging microscopy can be quantitatively performed with high sensitivity and without the spatial resolution degradation.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-11-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-06-16

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

Weak Hard X-Ray Emission from Two Broad Absorption Line Quasars Observed with NuStar: Compton-Thick Absorption or Intrinsic X-Ray Weakness?

Science.gov (United States)

Luo, B.; Brandt, W. N.; Alexander, D. M.; Harrison, F. A.; Stern, D.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W..;

WEAK HARD X-RAY EMISSION FROM TWO BROAD ABSORPTION LINE QUASARS OBSERVED WITH NuSTAR: COMPTON-THICK ABSORPTION OR INTRINSIC X-RAY WEAKNESS?

Energy Technology Data Exchange (ETDEWEB)

Luo, B.; Brandt, W. N. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Alexander, D. M.; Hickox, R. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Harrison, F. A.; Fuerst, F.; Grefenstette, B. W.; Madsen, K. K. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Bauer, F. E. [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Boggs, S. E.; Craig, W. W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, F. E. [DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Comastri, A. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Fabian, A. C. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Farrah, D. [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Fiore, F. [Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monteporzio Catone (Italy); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Matt, G. [Dipartimento di Matematica e Fisica, Universita degli Studi Roma Tre, via della Vasca Navale 84, I-00146 Roma (Italy); Ogle, P. [IPAC, California Institute of Technology, Mail Code 220-6, Pasadena, CA 91125 (United States); and others

2013-08-01

We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray weak at rest-frame 2-10 keV (16-120 times fainter than typical quasars). We would expect to obtain Almost-Equal-To 400-600 hard X-ray ({approx}> 10 keV) photons with NuSTAR, provided that these photons are not significantly absorbed (N{sub H} {approx}< 10{sup 24} cm{sup -2}). However, both BAL quasars are only detected in the softer NuSTAR bands (e.g., 4-20 keV) but not in its harder bands (e.g., 20-30 keV), suggesting that either the shielding gas is highly Compton-thick or the two targets are intrinsically X-ray weak. We constrain the column densities for both to be N{sub H} Almost-Equal-To 7 Multiplication-Sign 10{sup 24} cm{sup -2} if the weak hard X-ray emission is caused by obscuration from the shielding gas. We discuss a few possibilities for how PG 1004+130 could have Compton-thick shielding gas without strong Fe K{alpha} line emission; dilution from jet-linked X-ray emission is one likely explanation. We also discuss the intrinsic X-ray weakness scenario based on a coronal-quenching model relevant to the shielding gas and disk wind of BAL quasars. Motivated by our NuSTAR results, we perform a Chandra stacking analysis with the Large Bright Quasar Survey BAL quasar sample and place statistical constraints upon the fraction of intrinsically X-ray weak BAL quasars; this fraction is likely 17%-40%.

Discovery of Periodic Dips in the Brightest Hard X-Ray Source of M31 with EXTraS

Science.gov (United States)

Marelli, Martino; Tiengo, Andrea; De Luca, Andrea; Salvetti, David; Saronni, Luca; Sidoli, Lara; Paizis, Adamantia; Salvaterra, Ruben; Belfiore, Andrea; Israel, Gianluca; Haberl, Frank; D’Agostino, Daniele

2017-12-01

We performed a search for eclipsing and dipping sources in the archive of the EXTraS project—a systematic characterization of the temporal behavior of XMM-Newton point sources. We discovered dips in the X-ray light curve of 3XMM J004232.1+411314, which has been recently associated with the hard X-ray source dominating the emission of M31. A systematic analysis of XMM-Newton observations revealed 13 dips in 40 observations (total exposure time of ∼0.8 Ms). Among them, four observations show two dips, separated by ∼4.01 hr. Dip depths and durations are variable. The dips occur only during low-luminosity states ({L}0.2{--12}< 1× {10}38 erg s‑1), while the source reaches {L}0.2{--12}∼ 2.8× {10}38 erg s‑1. We propose that this system is a new dipping low-mass X-ray binary in M31 seen at high inclination (60°–80°) the observed dipping periodicity is the orbital period of the system. A blue HST source within the Chandra error circle is the most likely optical counterpart of the accretion disk. The high luminosity of the system makes it the most luminous (not ULX) dipper known to date.

Incorporating solid state drives into distributed storage systems

OpenAIRE

Wacha, Rosie

2012-01-01

Big data stores are becoming increasingly important in a variety of domains including scientific computing, internet applications, and business applications. For price and performance reasons, such storage is comprised of magnetic hard drives. To achieve the necessary degree of performance and reliability, the drives are configured into storage subsystems based on RAID (Redundant Array of Independent Disks). Because of their mechanical nature, hard drives are relatively power-hungry and slow ...

Sexual antagonism and meiotic drive cause stable linkage disequilibrium and favour reduced recombination on the X chromosome.

Science.gov (United States)

Rydzewski, W T; Carioscia, S A; Liévano, G; Lynch, V D; Patten, M M

2016-06-01

Sexual antagonism and meiotic drive are sex-specific evolutionary forces with the potential to shape genomic architecture. Previous theory has found that pairing two sexually antagonistic loci or combining sexual antagonism with meiotic drive at linked autosomal loci augments genetic variation, produces stable linkage disequilibrium (LD) and favours reduced recombination. However, the influence of these two forces has not been examined on the X chromosome, which is thought to be enriched for sexual antagonism and meiotic drive. We investigate the evolution of the X chromosome under both sexual antagonism and meiotic drive with two models: in one, both loci experience sexual antagonism; in the other, we pair a meiotic drive locus with a sexually antagonistic locus. We find that LD arises between the two loci in both models, even when the two loci freely recombine in females and that driving haplotypes will be enriched for male-beneficial alleles, further skewing sex ratios in these populations. We introduce a new measure of LD, Dz', which accounts for population allele frequencies and is appropriate for instances where these are sex specific. Both models demonstrate that natural selection favours modifiers that reduce the recombination rate. These results inform observed patterns of congealment found on driving X chromosomes and have implications for patterns of natural variation and the evolution of recombination rates on the X chromosome. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Hard magnetic off-stoichiometric (Fe,Sb){sub 2+x}Hf{sub 1-x} intermetallic phase

Energy Technology Data Exchange (ETDEWEB)

Goll, D.; Gross, T.; Loeffler, R.; Pflanz, U.; Vogel, T.; Kopp, A.; Grubesa, T.; Schneider, G. [Aalen University, Materials Research Institute (Germany)

2017-09-15

By high-throughput screening the ternary Fe-Hf-Sb system, off-stoichiometric (Fe,Sb){sub 2+x}Hf{sub 1-x} with a composition of Fe60.0-Hf26.5-Sb13.5 with high potential as hard magnetic phase is discovered. By quantitative domain structure analysis, promising intrinsic properties of J{sub s} ∝ 1 T, K{sub 1} ∝ 1.5 MJ m{sup -3} are found at room temperature. By magnetometry, bulk intrinsic properties of J{sub s} ∝ 0.7 T, K{sub 1} ∝ 1.4 MJ m{sup -3} are found. Alloying elements like Co or Mn turns out to be an effective adjusting screw on the crystal structure and ferromagnetic behavior. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Possibilities and Challenges of Scanning Hard X-ray Spectro-microscopy Techniques in Material Sciences

Directory of Open Access Journals (Sweden)

Andrea Somogyi

2015-06-01

Full Text Available Scanning hard X-ray spectro-microscopic imaging opens unprecedented possibilities in the study of inhomogeneous samples at different length-scales. It gives insight into the spatial variation of the major and minor components, impurities and dopants of the sample, and their chemical and electronic states at micro- and nano-meter scales. Measuring, modelling and understanding novel properties of laterally confined structures are now attainable. The large penetration depth of hard X-rays (several keV to several 10 keV beam energy makes the study of layered and buried structures possible also in in situ and in operando conditions. The combination of different X-ray analytical techniques complementary to scanning spectro-microscopy, such as X-ray diffraction, X-ray excited optical luminescence, secondary ion mass spectrometry (SIMS and nano-SIMS, provides access to optical characteristics and strain and stress distributions. Complex sample environments (temperature, pressure, controlled atmosphere/vacuum, chemical environment are also possible and were demonstrated, and allow as well the combination with other analysis techniques (Raman spectroscopy, infrared imaging, mechanical tensile devices, etc. on precisely the very same area of the sample. The use of the coherence properties of X-rays from synchrotron sources is triggering emerging experimental imaging approaches with nanometer lateral resolution. New fast analytical possibilities pave the way towards statistically significant studies at multi- length-scales and three dimensional tomographic investigations. This paper gives an overview of these techniques and their recent achievements in the field of material sciences.

Sub-micron Hard X-ray Fluorescence Imaging of Synthetic Elements

Science.gov (United States)

Jensen, Mark P.; Aryal, Baikuntha P.; Gorman-Lewis, Drew; Paunesku, Tatjana; Lai, Barry; Vogt, Stefan; Woloschak, Gayle E.

2013-01-01

Synchrotron-based X-ray fluorescence microscopy (SXFM) using hard X-rays focused into sub-micron spots is a powerful technique for elemental quantification and mapping, as well as microspectroscopic measurement such as μ-XANES (X-ray absorption near edge structure). We have used SXFM to image and simultaneously quantify the transuranic element plutonium at the L3 or L2 edge as well as lighter biologically essential elements in individual rat pheochromocytoma (PC12) cells after exposure to the long-lived plutonium isotope 242Pu. Elemental maps reveal that plutonium localizes principally in the cytoplasm of the cells and avoids the cell nucleus, which is marked by the highest concentrations of phosphorus and zinc, under the conditions of our experiments. The minimum detection limit under typical acquisition conditions for an average 202 μm2 cell is 1.4 fg Pu/cell or 2.9 × 10−20 moles Pu/μm2, which is similar to the detection limit of K-edge SXFM of transition metals at 10 keV. Copper electron microscopy grids were used to avoid interference from gold X-ray emissions, but traces of strontium present in naturally occurring calcium can still interfere with plutonium detection using its Lα X-ray emission. PMID:22444530

Achromatic nested Kirkpatrick–Baez mirror optics for hard X-ray nanofocusing

International Nuclear Information System (INIS)

Liu, Wenjun; Ice, Gene E.; Assoufid, Lahsen; Liu, Chian; Shi, Bing; Khachatryan, Ruben; Qian, Jun; Zschack, Paul; Tischler, Jonathan Z.; Choi, J.-Y.

2011-01-01

A nested Kirkpatrick–Baez mirror pair has been designed, fabricated and tested for achromatic nanofocusing synchrotron hard X-rays. The prototype system achieved a FWHM focal spot of about 150 nm in both horizontal and vertical directions. The first test of nanoscale-focusing Kirkpatrick–Baez (KB) mirrors in the nested (or Montel) configuration used at a hard X-ray synchrotron beamline is reported. The two mirrors are both 40 mm long and coated with Pt to produce a focal length of 60 mm at 3 mrad incident angle, and collect up to a 120 µm by 120 µm incident X-ray beam with maximum angular acceptance of 2 mrad and a broad bandwidth of energies up to 30 keV. In an initial test a focal spot of about 150 nm in both horizontal and vertical directions was achieved with either polychromatic or monochromatic beam. The nested mirror geometry, with two mirrors mounted side-by-side and perpendicular to each other, is significantly more compact and provides higher demagnification than the traditional sequential KB mirror arrangement. Ultimately, nested mirrors can focus larger divergence to improve the diffraction limit of achromatic optics. A major challenge with the fabrication of the required mirrors is the need for near-perfect mirror surfaces near the edge of at least one of the mirrors. Special polishing procedures and surface profile coating were used to preserve the mirror surface quality at the reflecting edge. Further developments aimed at achieving diffraction-limited focusing below 50 nm are underway

Improved hardness of laser alloyed X12CrNiMo martensitic stainless steel

CSIR Research Space (South Africa)

Adebiyi, DI

2011-07-01

Full Text Available The improvement in hardness of X12CrNiMo martensitic stainless steel laser alloyed with 99.9% pure titanium carbide, stellite 6 and two cases of premixed ratio of titanium carbide and stellite 6 [TiC (30 wt.%)- stellite 6 (70 wt.%) and TiC (70 wt...

Thin-film-based scintillators for hard x-ray microimaging detectors: the ScinTAX Project

Science.gov (United States)

Rack, A.; Cecilia, A.; Douissard, P.-A.; Dupré, K.; Wesemann, V.; Baumbach, T.; Couchaud, M.; Rochet, X.; Riesemeier, H.; Radtke, M.; Martin, T.

2014-09-01

The project ScinTAX developed novel thin scintillating films for the application in high performance X-ray imaging and subsequent introduced new X-ray detectors to the market. To achieve this aim lutetium orthosilicate (LSO) scintillators doped with different activators were grown successfully by liquid phase epitaxy. The high density of LSO (7.4 g/cm3), the effective atomic number (65.2) and the high light yield make this scintillator highly applicable for indirect X-ray detection in which the ionizing radiation is converted into visible light and then registered by a digital detector. A modular indirect detection system has been developed to fully exploit the potential of this thin film scintillator for radiographic and tomographic imaging. The system is compatible for high-resolution imaging with moderate dose as well as adaptable to intense high-dose applications where radiation hard microimaging detectors are required. This proceedings article shall review the achieved performances and technical details on this high-resolution detector system which is now available. A selected example application demonstrates the great potential of the optimized detector system for hard X-ray microimaging, i.e. either to improve image contrast due to the availability of efficient thin crystal films or to reduce the dose to the sample.

The high energy X-ray spectrum of 4U 1700-37 observed from OSO 8

Science.gov (United States)

Dolan, J. F.; Coe, M. J.; Crannell, C. J.; Dennis, B. R.; Frost, K. J.; Orwig, L. E.; Maurer, G. S.

1980-01-01

The most intense hard X-ray source in the confused region in Scorpius has been identified as 4U 1700-37 (=HD 153919). Observations extending over three binary periods in 1978 September were carried out with the high-energy X-ray spectrometer on OSO 8. The 3.4 day modulation is seen above 20 keV with the intensity during eclipse being consistent with zero flux. The photonumber spectrum from 20 to 150 keV is well represented by a single power law with a photonumber spectral index of -2.77 + or - 0.35 or by a thermal bremsstrahlung spectrum with kT = 27 (+15, -7)keV. The counting rate above 20 keV outside of eclipse shows no evidence for the 96.8 minute X-ray modulation previously reported at lower energies. Despite the difficulties that exist in reconciling both the lack of periodic modulation in the emitted X-radiation and the orbital dynamics of the system with our currently accepted theories of the evolution and physical properties of neutron stars, the observed properties of 4U 1700-37 are all consistent with the source being a spherically accreting neutron star rather than a black hole.

XMM-Newton Detection of Hard X-Ray Emission in the Nitrogen-Type Wolf-Rayet Star WR 110

Science.gov (United States)

Skinner, Stephen L.; Zhekov, Svetozar A.; Güdel, Manuel; Schmutz, Werner

2002-06-01

We have used the excellent sensitivity of XMM-Newton to obtain the first high-quality X-ray spectrum of a Wolf-Rayet (W-R) star that is not known to be a member of a binary system. Our target, the nitrogen-type star WR 110 (HD 165688), was also observed and detected with the Very Large Array at four different frequencies. The radio flux density increases with frequency according to a power law Sν~ν+0.64+/-0.10, in very good agreement with the behavior expected for free-free wind emission. The radio data give an ionized mass-loss rate M=4.9×10-5 Msolar yr-1 for an assumed spherical constant-velocity wind. The undispersed CCD X-ray spectra reveal strong emission lines from He-like ions of Mg, Si, and S. The emission measure distribution shows a dominant contribution from cool plasma with a characteristic temperature kTcool~0.5 keV (~6 MK). Little or no excess absorption of this cool component above the value expected from the visual extinction is present. We conclude that the bulk of the cool plasma detected by XMM-Newton lies at hundreds of stellar radii or more if the wind is approximately spherical and homogeneous, but it could lie closer to the star if the wind is clumped. If the cool plasma is due to instability-driven wind shocks, then typical shock velocities are vs~340-550 km s-1 and the average filling factor of X-ray-emitting gas in the wind is no larger than f~10-6. A surprising result is the unambiguous detection of a hard X-ray component that is clearly seen in the hard-band images and the spectra. This hard component accounts for about half of the observed flux and can be acceptably fitted by a hot, optically thin thermal plasma or a power-law model. If the emission is thermal, then a temperature kThot>=3 keV is derived. Such high temperatures are not predicted by current instability-driven wind shock models, and a different mechanism is thus required to explain the hard X-rays. We examine several possible mechanisms and show that the hard emission

Solar Coronal Events with Extended Hard X-ray and Gamma-ray Emission

Science.gov (United States)

Hudson, H. S.

2017-12-01

A characteristic pattern of solar hard X-ray emission, first identified in SOL1969-03-31 by Frost & Dennis (1971) now has been linked to prolonged high-energy gamma-ray emission detected by the Fermi/LAT experiment, for example in SOL2014-09-01. The distinctive features of these events include flat hard X-ray spectra extending well above 100 keV, a characteristic pattern of time development, low-frequency gyrosynchrotron peaks, CME association, and gamma-rays identifiable with pion decay originating in GeV ions. The identification of these events with otherwise known solar structures nevertheless remains elusive, in spite of the wealth of imagery available from AIA. The quandary is that these events have a clear association with CMEs in the high corona, and yet the gamma-ray production implicates the photosphere itself. The vanishingly small loss cone in the nominal acceleration region makes this extremely difficult. I propose direct inward advection of a part of the SEP particle population, as created on closed field structures, as a possible resolution of this puzzle, and note that this requires retracting magnetic structures on long time scales following the flare itself.

Current status of the hard x-ray nanoprobe beamline at the SSRF

Science.gov (United States)

Li, Aiguo; Jiang, Hui; Wang, Hua; Zhang, Zhaohong; He, Yan; Zhao, Gaofeng; Shu, Deming

2017-09-01

The hard X-ray nanoprobe beamline (HXN) designed at the Shanghai Synchrotron Radiation facility (SSRF) will be of capability to realize a focal spot size of 10 nm for hard X-rays to satisfy requirements in biology, environmental, material sciences and etc.. The beamline includes two modes of operation, high energy resolution mode and high flux mode respectively. High flux mode utilizes the multilayer KB system to obtain high-flux diffraction-limited focusing of 10nm. An ultra-high-precision figure fabrication for diffraction-limited focusing is required to meet the Rayleigh Criterion. An idea to overcome this problem is to introduce a phase compensator upstream of the KB system to compensate the wavefront errors in the beamline. At wavelength speckle-based method will be used to measure the wavefront error in the beamline and feedback to the phase compensator. Vibration measurements have been carried out at the secondary source and endstation hutch. The flexure hinge mechanisms and high-precision actuators ensure the KB system and sample manipulator working with high stability. The building of HXN has been designed and is under construction at present.

Hard X-ray emission from accretion shocks around galaxy clusters

Science.gov (United States)

Kushnir, Doron; Waxman, Eli

2010-02-01

We show that the hard X-ray (HXR) emission observed from several galaxy clusters is consistent with a simple model, in which the nonthermal emission is produced by inverse Compton scattering of cosmic microwave background photons by electrons accelerated in cluster accretion shocks: The dependence of HXR surface brightness on cluster temperature is consistent with that predicted by the model, and the observed HXR luminosity is consistent with the fraction of shock thermal energy deposited in relativistic electrons being lesssim0.1. Alternative models, where the HXR emission is predicted to be correlated with the cluster thermal emission, are disfavored by the data. The implications of our predictions to future HXR observations (e.g. by NuStar, Simbol-X) and to (space/ground based) γ-ray observations (e.g. by Fermi, HESS, MAGIC, VERITAS) are discussed.

Hard X-ray emission from accretion shocks around galaxy clusters

Energy Technology Data Exchange (ETDEWEB)

Kushnir, Doron; Waxman, Eli, E-mail: doron.kushnir@weizmann.ac.il, E-mail: eli.waxman@weizmann.ac.il [Physics Faculty, Weizmann Institute of Science, PO Box 26, Rehovot (Israel)

2010-02-01

We show that the hard X-ray (HXR) emission observed from several galaxy clusters is consistent with a simple model, in which the nonthermal emission is produced by inverse Compton scattering of cosmic microwave background photons by electrons accelerated in cluster accretion shocks: The dependence of HXR surface brightness on cluster temperature is consistent with that predicted by the model, and the observed HXR luminosity is consistent with the fraction of shock thermal energy deposited in relativistic electrons being ∼<0.1. Alternative models, where the HXR emission is predicted to be correlated with the cluster thermal emission, are disfavored by the data. The implications of our predictions to future HXR observations (e.g. by NuStar, Simbol-X) and to (space/ground based) γ-ray observations (e.g. by Fermi, HESS, MAGIC, VERITAS) are discussed.

Hard X-ray emission from accretion shocks around galaxy clusters

International Nuclear Information System (INIS)

Kushnir, Doron; Waxman, Eli

2010-01-01

We show that the hard X-ray (HXR) emission observed from several galaxy clusters is consistent with a simple model, in which the nonthermal emission is produced by inverse Compton scattering of cosmic microwave background photons by electrons accelerated in cluster accretion shocks: The dependence of HXR surface brightness on cluster temperature is consistent with that predicted by the model, and the observed HXR luminosity is consistent with the fraction of shock thermal energy deposited in relativistic electrons being ∼<0.1. Alternative models, where the HXR emission is predicted to be correlated with the cluster thermal emission, are disfavored by the data. The implications of our predictions to future HXR observations (e.g. by NuStar, Simbol-X) and to (space/ground based) γ-ray observations (e.g. by Fermi, HESS, MAGIC, VERITAS) are discussed

The first multi-wavelength campaign of AXP 4U 0142+61 from radio to hard X-rays

NARCIS (Netherlands)

den Hartog, P.R.; Kuiper, L.; Hermsen, W.; Rea, N.; Durant, M.; Stappers, B.; Kaspi, V.M.; Dib, R.

2007-01-01

For the first time a quasi-simultaneous multi-wavelength campaign has been performed on an Anomalous X-ray Pulsar from the radio to the hard X-ray band. 4U 0142+61 was an INTEGRAL target for 1 Ms in July 2005. During these observations it was also observed in the X-ray band with Swift and RXTE, in

A Multiwavelength Study of Cygnus X-3

Science.gov (United States)

McCollough, M. L; Robinson, C. R.; Zhang, S. N.; Paciesas, W. S.; Harmon, B. A.; Hjellming, R. M.; Rupen, M.; Waltman, E. B.; Foster, R. S.; Ghigo, F. D.

1997-01-01

We present a global comparison of long term observations of the hard X-ray (20-100 keV), soft X-ray (1.5-12 keV), infrared (1-2 micron) and radio (2.25, 8.3 and 15 GHz) bands for the unusual X-ray binary Cygnus X-3. Data were obtained in the hard X-ray band from CGRO/BATSE, in the soft X-ray band from Rossi Xray Timing Explorer (RXTE)/ASM, in the radio band from the Green Bank Interferometer and Ryle Telescope and in the infrared band from various ground based observatories. Radio flares, quenched radio states and quiescent radio emission can all be associated with changes in the hard and soft X-ray intensity. The injection of plasma into the radio jet is directly related to changes in the hard and soft X-ray emission. The infrared observations are examined in the context of these findings.

Design and performance of a one square meter proportional counter system for hard X-ray astronomy

International Nuclear Information System (INIS)

Bazzano, A.; Boccaccini, L.; La Padula, C.D.; Mastropietro, M.; Patriarca, R.; Polcaro, F.; Ubertini, P.

1983-01-01

A versatile balloon borne hard X-ray experiment with a very large area (approx.= 1.1 m 2 ) and high spectral resolution has been developed for the study of the hard X-ray sources in the energy range 20-180 keV. The telescope consists of four multiwire proportional chambers (MWPC) that have a geometrical sensitive area of 2700 cm 2 each. The detector system has a sensitivity of approx.= 10 -5 photons cm -2 s -1 keV -1 during a typical balloon observation. A background rate of approx.= 3 x 10 -4 counts cm -2 s -1 keV -1 was observed in the operative energy range at 2.4 gm/cm 2 ceiling altitude and geographic latitude of 38 0 N. The design details, fabrication and flight performance of the instrument are briefly discussed with reference to the effectiveness of background reduction and other test parameters. (orig.)

Hard X-ray submicrometer tomography of human brain tissue at Diamond Light Source

Science.gov (United States)

Khimchenko, A.; Bikis, C.; Schulz, G.; Zdora, M.-C.; Zanette, I.; Vila-Comamala, J.; Schweighauser, G.; Hench, J.; Hieber, S. E.; Deyhle, H.; Thalmann, P.; Müller, B.

2017-06-01

There is a lack of the necessary methodology for three-dimensional (3D) investigation of soft tissues with cellular resolution without staining or tissue transformation. Synchrotron radiation based hard X-ray in-line phase contrast tomography using single-distance phase reconstruction (SDPR) provides high spatial resolution and density contrast for the visualization of individual cells using a standard specimen preparation and data reconstruction. In this study, we demonstrate the 3D characterization of a formalin-fixed paraffin-embedded (FFPE) human cerebellum specimen by SDPR at the Diamond-Manchester Imaging Branchline I13-2 (Diamond Light Source, UK) at pixel sizes down to 0.45 μm. The approach enables visualization of cerebellar layers (Stratum moleculare and Stratum granulosum), the 3D characterization of individual cells (Purkinje, stellate and granule cells) and can even resolve some subcellular structures (nucleus and nucleolus of Purkinje cells). The tomographic results are qualitatively compared to hematoxylin and eosin (H&E) stained histological sections. We demonstrate the potential benefits of hard X-ray microtomography for the investigations of biological tissues in comparison to conventional histology.

Hard X-ray submicrometer tomography of human brain tissue at Diamond Light Source

International Nuclear Information System (INIS)

Khimchenko, A; Bikis, C; Schulz, G; Hieber, S E; Deyhle, H; Thalmann, P; Müller, B; Zdora, M-C; Zanette, I; Vila-Comamala, J; Schweighauser, G; Hench, J

2017-01-01

There is a lack of the necessary methodology for three-dimensional (3D) investigation of soft tissues with cellular resolution without staining or tissue transformation. Synchrotron radiation based hard X-ray in-line phase contrast tomography using single-distance phase reconstruction (SDPR) provides high spatial resolution and density contrast for the visualization of individual cells using a standard specimen preparation and data reconstruction. In this study, we demonstrate the 3D characterization of a formalin-fixed paraffin-embedded (FFPE) human cerebellum specimen by SDPR at the Diamond-Manchester Imaging Branchline I13-2 (Diamond Light Source, UK) at pixel sizes down to 0.45 μm. The approach enables visualization of cerebellar layers ( Stratum moleculare and Stratum granulosum ), the 3D characterization of individual cells (Purkinje, stellate and granule cells) and can even resolve some subcellular structures (nucleus and nucleolus of Purkinje cells). The tomographic results are qualitatively compared to hematoxylin and eosin (H and E) stained histological sections. We demonstrate the potential benefits of hard X-ray microtomography for the investigations of biological tissues in comparison to conventional histology. (paper)

Advances in indirect detector systems for ultra high-speed hard X-ray imaging with synchrotron light

Science.gov (United States)

Olbinado, M. P.; Grenzer, J.; Pradel, P.; De Resseguier, T.; Vagovic, P.; Zdora, M.-C.; Guzenko, V. A.; David, C.; Rack, A.

2018-04-01

We report on indirect X-ray detector systems for various full-field, ultra high-speed X-ray imaging methodologies, such as X-ray phase-contrast radiography, diffraction topography, grating interferometry and speckle-based imaging performed at the hard X-ray imaging beamline ID19 of the European Synchrotron—ESRF. Our work highlights the versatility of indirect X-ray detectors to multiple goals such as single synchrotron pulse isolation, multiple-frame recording up to millions frames per second, high efficiency, and high spatial resolution. Besides the technical advancements, potential applications are briefly introduced and discussed.

High Capacity of Hard Carbon Anode in Na-Ion Batteries Unlocked by PO _x Doping

Energy Technology Data Exchange (ETDEWEB)

Li, Zhifei; Ma, Lu; Surta, Todd Wesley; Bommier, Clement; Jian, Zelang; Xing, Zhenyu; Stickle, William F.; Dolgos, Michelle; Amine, Khalil; Lu, Jun; Wu, Tianpin; Ji, Xiulei

2016-08-12

The capacity of hard carbon anodes in Na-ion batteries 2.5 rarely reaches values beyond 300 mAh/g. We report that doping POx into local structures of hard carbon increases its reversible capacity from 283 to 359 mAh/g. We confirm that the doped POx is redox inactive by X-ray adsorption near edge structure measurements, thus not contributing to the higher capacity. We observe two significant changes of hard carbon's local structures caused by doping. First, the (002) d-spacing inside the turbostratic nanodomains is increased, revealed by both laboratory and synchrotron X-ray diffraction. Second, doping turns turbostratic nanodomains more defective along ab planes, indicated by neutron total scattering and the associated pair distribution function studies. The local structural changes of hard carbon are correlated to the higher capacity, where both the plateau and slope regions in the potential profiles are enhanced. Our study demonstrates that Na-ion storage in hard carbon heavily depends on carbon local structures, where such structures, despite being disordered, can be tuned toward unusually high capacities.

Hard X-ray synchrotron light source for industrial and materials research applications

International Nuclear Information System (INIS)

Lehr, H.; Ehrfeld, W.; Moser, H.O.; Schmidt, M.; Herminghaus, H.

1992-01-01

The requirements for industrial production or for an industry-related analytical environment is demonstrated for the case of the proposed hard X-ray synchrotron light source. The source is intended to provide radiation mainly for deep X-ray lithography as part of the LIGA-process in microfabrication, and for analytical and diagnostic purposes in materials research and microtechnology. It offers up to 48 bending magnet beamlines with a characteristic wavelength of 2 A. An electron energy of 2.5 GeV and normal conducting magnets will be used. A FODO lattice with a beam emittance of 3x10 -7 m rad and four dispersion-free straight sections to accommodate insertion devices, injection elements and RF structures has been designed. (R.P.) 5 refs.; 4 figs.; 1 tab

Characterisation and application of a laser-based hard x-ray source

International Nuclear Information System (INIS)

Graetz, M.

1998-11-01

Hard X-rays are generated by focusing 110 fs laser pulses with intensities of about 1017 W/cm 2 onto solid metal targets. Characteristic properties of this X-ray source are the small source size, the short pulse duration and the high peak flux. The aim of the present work was to characterise this X-ray source and to demonstrate possible applications. A comparison with other X-ray sources and conventional imaging techniques is made. Characterising measurements were performed, including source size, emission spectrum, temporal behaviour, source stability and the influence of various laser parameters. The emission spectrum was measured using both energy-dispersive solid-state detectors and wavelength-dispersive crystal spectroscopy. The conversion efficiency from laser light to X-ray radiation was measured for different target materials. The laser ablation from different targets was studied. The feasibility of special imaging techniques, e.g. differential imaging and time-gated imaging, was investigated both theoretically and experimentally. Differential imaging allows for selective imaging of contrast agents, while time-gated imaging can reduce the influence of scattered radiation in X-ray imaging. Time-gated imaging was demonstrated in different imaging geometries, both for planar imaging and computed tomography imaging. Reasonable agreement between theoretically calculated values and experimental results was obtained

Characterisation and application of a laser-based hard x-ray source

Energy Technology Data Exchange (ETDEWEB)

Graetz, M

1998-11-01

Hard X-rays are generated by focusing 110 fs laser pulses with intensities of about 1017 W/cm{sup 2} onto solid metal targets. Characteristic properties of this X-ray source are the small source size, the short pulse duration and the high peak flux. The aim of the present work was to characterise this X-ray source and to demonstrate possible applications. A comparison with other X-ray sources and conventional imaging techniques is made. Characterising measurements were performed, including source size, emission spectrum, temporal behaviour, source stability and the influence of various laser parameters. The emission spectrum was measured using both energy-dispersive solid-state detectors and wavelength-dispersive crystal spectroscopy. The conversion efficiency from laser light to X-ray radiation was measured for different target materials. The laser ablation from different targets was studied. The feasibility of special imaging techniques, e.g. differential imaging and time-gated imaging, was investigated both theoretically and experimentally. Differential imaging allows for selective imaging of contrast agents, while time-gated imaging can reduce the influence of scattered radiation in X-ray imaging. Time-gated imaging was demonstrated in different imaging geometries, both for planar imaging and computed tomography imaging. Reasonable agreement between theoretically calculated values and experimental results was obtained 120 refs, figs, tabs

44Ti Nucleosynthesis Lines and Hard X-ray Continuum in Young SNRs: from INTEGRAL to Simbol-X

Science.gov (United States)

Renaud, M.; Terrier, R.; Trap, G.; Lebrun, F.; Decourchelle, A.; Vink, J.

2009-05-01

Supemovae and their remnants are the main Galactic nucleosynthesis sites and the privileged sources of Galactic cosmic rays. The youngest of such remnants can be studied through two distinct observational features: 44Ti γ-ray lines and the hard X-ray nonthermal continuum emission. The former gives unique information on the nucleosynthesis conditions occuring during the first stages of the explosion, while the latter provides clues on acceleration processes at supernova remnant shocks. In this contribution, we present new INTEGRAL results on Tycho, the remnant of a historical supernova, and on G1.9+0.3, which has been recently unveiled as the youngest Galactic supernova remnant. Expectations with Simbol-X are also addressed.

44Ti Nucleosynthesis Lines and Hard X-ray Continuum in Young SNRs: from INTEGRAL to Simbol-X

International Nuclear Information System (INIS)

Renaud, M.; Terrier, R.; Lebrun, F.; Trap, G.; Decourchelle, A.; Vink, J.

2009-01-01

Supemovae and their remnants are the main Galactic nucleosynthesis sites and the privileged sources of Galactic cosmic rays. The youngest of such remnants can be studied through two distinct observational features: 44 Tiγ-ray lines and the hard X-ray nonthermal continuum emission. The former gives unique information on the nucleosynthesis conditions occuring during the first stages of the explosion, while the latter provides clues on acceleration processes at supernova remnant shocks. In this contribution, we present new INTEGRAL results on Tycho, the remnant of a historical supernova, and on G1.9+0.3, which has been recently unveiled as the youngest Galactic supernova remnant. Expectations with Simbol-X are also addressed.

Polymer Compund Refractive Lenses for Hard X-ray Nanofocusing

OpenAIRE

Krywka, Christina; Last, Arndt; Marschall, Felix; Markus, Otto; Georgi, Sebastian; Mueller, Martin; Mohr, Jürgen

2016-01-01

Compound refractive lenses fabricated out of SU-8 negative photoresist have been used to generate a nanofocused, i.e. sub-μm sized X-ray focal spot at an X-ray nanodiffraction setup. X-ray microscopy and X-ray diffraction techniques have conceptually different demands on nanofocusing optical elements and so with the application of X-ray nanodiffraction in mind, this paper presents the results of an initial characterization of polymer lenses used as primary focusin...

Lower hybrid current drive: an overview of simulation models, benchmarking with experiment, and predictions for future devices

International Nuclear Information System (INIS)

Bonoli, P.T.; Barbato, E.; Imbeaux, F.

2003-01-01

This paper reviews the status of lower hybrid current drive (LHCD) simulation and modeling. We first discuss modules used for wave propagation, absorption, and current drive with particular emphasis placed on comparing exact numerical solutions of the Fokker Planck equation in 2-dimension with solution methods that employ 1-dimensional and adjoint approaches. We also survey model predictions for LHCD in past and present experiments showing detailed comparisons between simulated and observed current drive efficiencies and hard X-ray profiles. Finally we discuss several model predictions for lower hybrid current profile control in proposed next step reactor options. (authors)

X ray spectra of X Per. [oso-8 observations

Science.gov (United States)

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

1978-01-01

The cosmic X-ray spectroscopy experiment on OSO-8 observed X Per for twenty days during two observations in Feb. 1976 and Feb. 1977. The spectrum of X Per varies in phase with its 13.9 min period, hardening significantly at X-ray minimum. Unlike other X-ray binary pulsar spectra, X Per's spectra do not exhibit iron line emission or strong absorption features. The data show no evidence for a 22 hour periodicity in the X-ray intensity of X Per. These results indicate that the X-ray emission from X Per may be originating from a neutron star in a low density region far from the optically identified Be star.

Searches for hard X-ray gamma-ray burst afterglows with the BAT on Swift

International Nuclear Information System (INIS)

Krimm, Hans A.; Ozawa, Hideki; Weidenspointner, Georg; Barbier, Louis M.; Barthelmy, Scott D.; Gehrels, Neil; Parsons, Ann M.; Tueller, Jack; Eftekharzadeh, Ardeshir; Hullinger, Derek D.; Markwardt, Craig; Fenimore, Edward E.; Palmer, David M.

2003-01-01

The Burst Alert Telescope (BAT) on the Swift gamma ray burst mission will continue to observe the fields of all detected gamma-ray bursts for several days after the prompt emission has faded. Utilizing first event-by-event data, then one minute and later five minute survey accumulations, the BAT will be extremely sensitive to the hard X-ray afterglow known to be associated with many bursts. This data will cover the crucial transition of the afterglow from rapid variability to the smoothly decaying power law in time and will extend observations of the tails of individual bursts to longer time scales than have been achievable so far. Since Swift is sensitive to short duration GRBs, we will also be able to determine whether hard X-ray afterglows are associated with short GRBs. The BAT will provide high resolution spectra of burst afterglows, allowing us to study in detail the time evolution of GRB spectra

Discovery of X-Ray Emission from the Galactic Supernova Remnant G32.8-0.1 with Suzaku

Science.gov (United States)

Bamba, Aya; Terada, Yukikatsu; Hewitt, John; Petre, Robert; Angelini, Lorella; Safi-Harb, Samar; Zhou, Ping; Bocchino, Fabrizio; Sawada, Makoto

2016-01-01

We present the first dedicated X-ray study of the supernova remnant (SNR) G32.8-0.1 (Kes 78) with Suzaku. X-ray emission from the whole SNR shell has been detected for the first time. The X-ray morphology is well correlated with the emission from the radio shell, while anti-correlated with the molecular cloud found in the SNR field. The X-ray spectrum shows not only conventional low-temperature (kT approximately 0.6 kiloelectronvolts) thermal emission in a nonequilibrium ionization state, but also a very high-temperature (approximately 3.4 kiloelectronvolts) component with a very low ionization timescale (approximately 2.7 times 10 (sup 9) per cubic centimeter per second), or a hard nonthermal component with a photon index Gamma approximately equal to 2.3. The average density of the low-temperature plasma is rather low, of the order of 10 (sup -3) - 10 (sup -2) per cubic centimeter, implying that this SNR is expanding into a low-density cavity. We discuss the X-ray emission of the SNR, also detected in teraelectronvolts with H.E.S.S. (High Energy Stereoscopic System), together with multi-wavelength studies of the remnant and other gamma-ray emitting SNRs, such as W28 and RCW 86. Analysis of a time-variable source, 2XMM J185114.3-000004, found in the northern part of the SNR, is also reported for the first time. Rapid time variability and a heavily absorbed hard-X-ray spectrum suggest that this source could be a new supergiant fast X-ray transient.

Radiation-hard/high-speed parallel optical links

Energy Technology Data Exchange (ETDEWEB)

Gan, K.K., E-mail: gan@mps.ohio-state.edu [Department of Physics, The Ohio State University, Columbus, OH 43210 (United States); Buchholz, P.; Heidbrink, S. [Fachbereich Physik, Universität Siegen, Siegen (Germany); Kagan, H.P.; Kass, R.D.; Moore, J.; Smith, D.S. [Department of Physics, The Ohio State University, Columbus, OH 43210 (United States); Vogt, M.; Ziolkowski, M. [Fachbereich Physik, Universität Siegen, Siegen (Germany)

2016-09-21

We have designed and fabricated a compact parallel optical engine for transmitting data at 5 Gb/s. The device consists of a 4-channel ASIC driving a VCSEL (Vertical Cavity Surface Emitting Laser) array in an optical package. The ASIC is designed using only core transistors in a 65 nm CMOS process to enhance the radiation-hardness. The ASIC contains an 8-bit DAC to control the bias and modulation currents of the individual channels in the VCSEL array. The performance of the optical engine up at 5 Gb/s is satisfactory.

Design and development of the multilayer optics for the new hard x-ray mission

Science.gov (United States)

Pareschi, G.; Basso, S.; Citterio, O.; Spiga, D.; Tagliaferri, G.; Civitani, M.; Raimondi, L.; Sironi, G.; Cotroneo, V.; Negri, B.; Parodi, Giancarlo; Martelli, F.; Borghi, G.; Orlandi, A.; Vernani, D.; Valsecchi, G.; Binda, R.; Romaine, S.; Gorenstein, P.; Attinà, P.

2017-11-01

The New Hard X-ray Mission (NHXM) project will be operated by 2017 and is currently undergoing a Phase B study, under the coordination of the Italian Space Agency (ASI). The project is being proposed by an international team in the context of the ESA Call CV M3 as a Small Mission program, with a large Italian participation. It is based on 4 hard X-ray optics modules, each formed by 60 evenly spaced multilayer coated Wolter I mirror shells. An extensible bench is used to reach the 10 m focal length. The Wolter I monolithic substrates with multilayer coating are produced in NiCo by electroforming replication. Three of the mirror modules will host in the focal plane a hybrid a detector system (a soft X-ray Si DEPFET array plus a high energy CdTe detector). The detector of the fourth telescope will be a photoelectric polarimeter with imaging capabilities, operating from 2 up to 35 keV. The total on axis effective area of the three telescopes at 1 keV and 30 kev is of 1500 cm2 and 350 cm2 respectively, with an angular resolution of 20 arcsec HEW at 30 keV. In this paper we report on the design and development of the multilayer coated X-ray mirrors based on NiCo shells.

Study of current oscillations and hard x-ray emissions in pre-cursor phase of major disruptions in Damavand tokamak

International Nuclear Information System (INIS)

Amrollahi, R.

2002-01-01

We notice that the hard x-ray activity before disruption consists of a series of spikes, uniformly distributed in time domain forming an orderly periodic series of oscillations at a frequency of 6.0 kHz. Disruption starts with an initial fast rise followed by decay. Current decay occurs in two regimes: the first corresponds to slow decay, in which the current is oscillating and reducing down to ∼70% its max value, and the second corresponds to fast decay, in which it totally vanishes abruptly in about 0.2 ms. In the first regime, the loop voltage also oscillates with considerable amplitude. The frequency of oscillations in the first regime is measured to be also about 6.0 kHz. As well, they follow the oscillation phase of hard x-rays. Thus the micro-instabilities driven by runaway electrons, being responsible for the production of hard x-rays bursts and small current oscillations, play a significant role in the disruption. (author)

The successful of finite element to invent particle cleaning system by air jet in hard disk drive

Science.gov (United States)

Jai-Ngam, Nualpun; Tangchaichit, Kaitfa

2018-02-01

Hard Disk Drive manufacturing has faced very challenging with the increasing demand of high capacity drives for Cloud-based storage. Particle adhesion has also become increasingly important in HDD to gain more reliability of storage capacity. The ability to clean on surfaces is more complicated in removing such particles without damaging the surface. This research is aim to improve the particle cleaning in HSA by using finite element to develop the air flow model then invent the prototype of air cleaning system to remove particle from surface. Surface cleaning by air pressure can be applied as alternative for the removal of solid particulate contaminants that is adhering on a solid surface. These technical and economic challenges have driven the process development from traditional way that chemical solvent cleaning. The focus of this study is to develop alternative way from scrub, ultrasonic, mega sonic on surface cleaning principles to serve as a foundation for the development of new processes to meet current state-of-the-art process requirements and minimize the waste from chemical cleaning for environment safety.

Development of a hard x-ray focal plane compton polarimeter: a compact polarimetric configuration with scintillators and Si photomultipliers

Science.gov (United States)

Chattopadhyay, T.; Vadawale, S. V.; Goyal, S. K.; Mithun, N. P. S.; Patel, A. R.; Shukla, R.; Ladiya, T.; Shanmugam, M.; Patel, V. R.; Ubale, G. P.

2016-02-01

X-ray polarization measurement of cosmic sources provides two unique parameters namely degree and angle of polarization which can probe the emission mechanism and geometry at close vicinity of the compact objects. Specifically, the hard X-ray polarimetry is more rewarding because the sources are expected to be intrinsically highly polarized at higher energies. With the successful implementation of Hard X-ray optics in NuSTAR, it is now feasible to conceive Compton polarimeters as focal plane detectors. Such a configuration is likely to provide sensitive polarization measurements in hard X-rays with a broad energy band. We are developing a focal plane hard X-ray Compton polarimeter consisting of a plastic scintillator as active scatterer surrounded by a cylindrical array of CsI(Tl) scintillators. The scatterer is 5 mm diameter and 100 mm long plastic scintillator (BC404) viewed by normal PMT. The photons scattered by the plastic scatterer are collected by a cylindrical array of 16 CsI(Tl) scintillators (5 mm × 5 mm × 150 mm) which are read by Si Photomultiplier (SiPM). Use of the new generation SiPMs ensures the compactness of the instrument which is essential for the design of focal plane detectors. The expected sensitivity of such polarimetric configuration and complete characterization of the plastic scatterer, specially at lower energies have been discussed in [11, 13]. In this paper, we characterize the CsI(Tl) absorbers coupled to SiPM. We also present the experimental results from the fully assembled configuration of the Compton polarimeter.

The NuSTAR Hard X-Ray Survey of the Norma Arm Region

DEFF Research Database (Denmark)

Fornasini, Francesca M.; Tomsick, John A.; Hong, JaeSub

2017-01-01

We present a catalog of hard X-ray sources in a square-degree region surveyed by the Nuclear Spectroscopic Telescope Array (NuSTAR) in the direction of the Norma spiral arm. This survey has a total exposure time of 1.7 Ms, and the typical and maximum exposure depths are 50 ks and 1 Ms, respectively...... model with kT ≈ 15 keV, as observed for the CV candidates....

Accretion flow diagnostics with X-ray spectral timing: the hard state of SWIFT J1753.5-0127

NARCIS (Netherlands)

Cassatella, P.; Uttley, P.; Maccarone, T.

2012-01-01

Recent XMM-Newton studies of X-ray variability in the hard states of black hole X-ray binaries (BHXRBs) indicate that the variability is generated in the ‘standard’ optically thick accretion disc that is responsible for the multi-colour blackbody emission. The variability originates in the disc as

The NuSTAR Hard X-Ray Survey of the Norma Arm Region

Energy Technology Data Exchange (ETDEWEB)

Fornasini, Francesca M. [Astronomy Department, University of California, 601 Campbell Hall, Berkeley, CA 94720 (United States); Tomsick, John A.; Chiu, Jeng-Lun; Clavel, Maïca; Krivonos, Roman A.; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720 (United States); Hong, JaeSub [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gotthelf, Eric V.; Hailey, Charles J.; Mori, Kaya [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Bauer, Franz; Corral-Santana, Jesús [Instituto de Astrofísica and Centro de Astroingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile); Rahoui, Farid [European Southern Observatory, K. Schwarzschild-Strasse 2, D-85748 Garching bei München (Germany); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Bodaghee, Arash [Georgia College, 231 W. Hancock Street, Milledgeville, GA 31061 (United States); Alexander, David M. [Centre for Extragalactic Astronomy, Department of Physics, Durham University, Durham, DH1 3LE (United Kingdom); Barret, Didier [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); CNRS, Institut de Recherche en Astrophysique et Planétologie, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse cedex 4 (France); Christensen, Finn E., E-mail: f.fornasini@berkeley.edu [DTU Space—National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); and others

2017-04-01

We present a catalog of hard X-ray sources in a square-degree region surveyed by the Nuclear Spectroscopic Telescope Array ( NuSTAR ) in the direction of the Norma spiral arm. This survey has a total exposure time of 1.7 Ms, and the typical and maximum exposure depths are 50 ks and 1 Ms, respectively. In the area of deepest coverage, sensitivity limits of 5 × 10{sup −14} and 4 × 10{sup −14} erg s{sup −1} cm{sup −2} in the 3–10 and 10–20 keV bands, respectively, are reached. Twenty-eight sources are firmly detected, and 10 are detected with low significance; 8 of the 38 sources are expected to be active galactic nuclei. The three brightest sources were previously identified as a low-mass X-ray binary, high-mass X-ray binary, and pulsar wind nebula. Based on their X-ray properties and multiwavelength counterparts, we identify the likely nature of the other sources as two colliding wind binaries, three pulsar wind nebulae, a black hole binary, and a plurality of cataclysmic variables (CVs). The CV candidates in the Norma region have plasma temperatures of ≈10–20 keV, consistent with the Galactic ridge X-ray emission spectrum but lower than the temperatures of CVs near the Galactic center. This temperature difference may indicate that the Norma region has a lower fraction of intermediate polars relative to other types of CVs compared to the Galactic center. The NuSTAR log N –log S distribution in the 10–20 keV band is consistent with the distribution measured by Chandra at 2–10 keV if the average source spectrum is assumed to be a thermal model with kT  ≈ 15 keV, as observed for the CV candidates.

Design and performance of a one square meter proportional counter system for hard X-ray astronomy

Energy Technology Data Exchange (ETDEWEB)

Bazzano, A.; Boccaccini, L.; La Padula, C.D.; Mastropietro, M.; Patriarca, R.; Polcaro, F.; Ubertini, P. (Consiglio Nazionale delle Ricerche, Frascati (Italy). Lab. di Astrofisica Spaziale); Manchanda, R.K. (Consiglio Nazionale delle Ricerche, Frascati (Italy). Lab. di Astrofisica Spaziale; Tata Inst. of Fundamental Research, Bombay (India))

1983-09-01

A versatile balloon borne hard X-ray experiment with a very large area (approx.= 1.1 m/sup 2/) and high spectral resolution has been developed for the study of the hard X-ray sources in the energy range 20-180 keV. The telescope consists of four multiwire proportional chambers (MWPC) that have a geometrical sensitive area of 2700 cm/sup 2/ each. The detector system has a sensitivity of approx.= 10/sup -5/ photons cm/sup -2/ s/sup -1/ keV/sup -1/ during a typical balloon observation. A background rate of approx.= 3 x 10/sup -4/ counts cm/sup -2/ s/sup -1/ keV/sup -1/ was observed in the operative energy range at 2.4 gm/cm/sup 2/ ceiling altitude and geographic latitude of 38/sup 0/N. The design details, fabrication and flight performance of the instrument are briefly discussed with reference to the effectiveness of background reduction and other test parameters.

Modeling of finite systems irradiated by intense ultrashort hard X-ray pulses

Energy Technology Data Exchange (ETDEWEB)

Jurek, Zoltan [Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22607 Hamburg (Germany); Ziaja, Beata [Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22607 Hamburg (Germany); Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Krakow (Poland); Santra, Robin [Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22607 Hamburg (Germany); Department of Physics, University of Hamburg, Jungiusstrasse 9, 20355 Hamburg (Germany)

2013-07-01

Large number of experiments have already been carried out at the existing hard X-Ray Free-Electron Laser facilities (LCLS, SACLA) during the recent years. Their great success generates even higher anticipation for the forthcoming X-ray sources (European XFEL). Single molecule imaging and nanoplasma formation are the challenging projects with XFELs that investigate the interaction of finite, small objects, e.g. single molecules, atomic clusters with intense X-ray radiation. Accurate modelling of the time evolution of such irradiated systems is required in order to understand the current experiments and to inspire new directions of experimental investigation. In this presentation we report on our theoretical molecular-dynamics tool able to follow non-equilibrium dynamics within finite systems irradiated by intense X-ray pulses. We introduce the relevant physical processes, present computational methods used, discuss their limitations and also the specific constraints on calculations imposed by experimental conditions. Finally, we conclude with a few simulation examples.

In-flight PSF calibration of the NuSTAR hard X-ray optics

DEFF Research Database (Denmark)

An, Hongjun; Madsen, Kristin K.; Westergaard, Niels J.

2014-01-01

We present results of the point spread function (PSF) calibration of the hard X-ray optics of the Nuclear Spectroscopic Telescope Array (NuSTAR). Immediately post-launch, NuSTAR has observed bright point sources such as Cyg X-1, Vela X-1, and Her X-1 for the PSF calibration. We use the point source...... observations taken at several off-axis angles together with a ray-trace model to characterize the in-orbit angular response, and find that the ray-trace model alone does not fit the observed event distributions and applying empirical corrections to the ray-trace model improves the fit significantly. We...... describe the corrections applied to the ray-trace model and show that the uncertainties in the enclosed energy fraction (EEF) of the new PSF model is less than or similar to 3 for extraction apertures of R greater than or similar to 60" with no significant energy dependence. We also show that the PSF...

High-spatial resolution and high-spectral resolution detector for use in the measurement of solar flare hard x rays

International Nuclear Information System (INIS)

Desai, U.D.; Orwig, L.E.

1988-01-01

In the areas of high spatial resolution, the evaluation of a hard X-ray detector with 65 micron spatial resolution for operation in the energy range from 30 to 400 keV is proposed. The basic detector is a thick large-area scintillator faceplate, composed of a matrix of high-density scintillating glass fibers, attached to a proximity type image intensifier tube with a resistive-anode digital readout system. Such a detector, combined with a coded-aperture mask, would be ideal for use as a modest-sized hard X-ray imaging instrument up to X-ray energies as high as several hundred keV. As an integral part of this study it was also proposed that several techniques be critically evaluated for X-ray image coding which could be used with this detector. In the area of high spectral resolution, it is proposed to evaluate two different types of detectors for use as X-ray spectrometers for solar flares: planar silicon detectors and high-purity germanium detectors (HPGe). Instruments utilizing these high-spatial-resolution detectors for hard X-ray imaging measurements from 30 to 400 keV and high-spectral-resolution detectors for measurements over a similar energy range would be ideally suited for making crucial solar flare observations during the upcoming maximum in the solar cycle

The inner-relationship of hard X-ray and EUV bursts during solar flares

International Nuclear Information System (INIS)

Emslie, A.G.; Brown, J.C.; Donnelly, R.F.

1978-01-01

A comparison is made between the flux-versus-time profile in the EUV band and the thick target electron flux profile as inferred from hard X-rays for a number of moderately large solar flares. This complements Kane and Donnelly's (1971) study of small flares. The hard X-ray data are from ESRO TD-1A and the EUV inferred from SFD observations. Use of a chi 2 minimising method shows that the best overall fit between the profile fine structures obtains for synchronism to < approximately 5 s which is within the timing accuracy. This suggests that neither conduction nor convection is fast enough as the primary mechanism of energy transport into the EUV flare and rather favours heating by the electrons themselves or by some MHD wave process much faster than acoustic waves. The electron power deposited, for a thick target model, is however far greater than the EUV luminosity for any reasonable assumptions about the area and depth over which EUV is emitted. This means that either most of the power deposited is conducted away to the optical flare or that only a fraction < approximately 1-10% of the X-ray emitting electrons are injected downwards. Recent work on Hα flare heating strongly favours the latter alternative - i.e. that electrons are mostly confined in the corona. (Auth.)

Fabrication, performance, and figure metrology of epoxy-replicated aluminum foils for hard x-ray focusing multilayer-coated segmented conical optics

DEFF Research Database (Denmark)

Jimenez-Garate, M.A.; Craig, W.W.; Hailey, C.J.

2000-01-01

We fabricated x-ray mirrors for hard x-ray (greater than or equal to 10 keV) telescopes using multilayer coatings and an improved epoxy-replicated aluminum foil (ERAF) nonvacuum technology. The ERAF optics have similar to1 arcmin axial figure half-power diameter (HPD) and passed environmental...... telescope HPD, we designed a figure metrology system and a new mounting technique. We describe a cylindrical metrology system built for fast axial and roundness figure measurement of hard x-ray conical optics. These developments lower cost and improve the optics performance of the HEFT (high-energy focusing...

X-Ray and Near-Infrared Spectroscopy of Dim X-Ray Point Sources Constituting the Galactic Ridge X-Ray Emission

Directory of Open Access Journals (Sweden)

Kumiko Morihana

2014-12-01

Full Text Available We present the results of X-ray and Near-Infrared observations of the Galactic Ridge X-ray Emission (GRXE. We extracted 2,002 X-ray point sources in the Chandra Bulge Field (l =0°.113, b = 1°.424 down to ~10-14.8 ergscm-2s-1 in 2-8 keV band with the longest observation (900 ks of the GRXE. Based on X-ray brightness and hardness, we classied the X-ray point sources into three groups: A (hard, B (soft and broad spectrum, and C (soft and peaked spectrum. In order to know populations of the X-ray point sources, we carried out NIR imaging and spectroscopy observation. We identied 11% of X-ray point sources with NIR and extracted NIR spectra for some of them. Based on X-ray and NIR properties, we concluded that non-thermal sources in the group A are mostly active galactic nuclei and the thermal sources are mostly white dwarf binaries such as cataclysmic variables (CVs and Pre-CVs. We concluded that the group B and C sources are X-ray active stars in flare and quiescence, respectively.

Structure of the Circumnuclear Region of Seyfert 2 Galaxies Revealed by RXTE Hard X-Ray Observations of NGC 4945

Science.gov (United States)

Madejski, G.; Zycki, P.; Done, C.; Valinia, A.; Blanco, P.; Rothschild, R.; Turek, B.

2000-01-01

NGC 4945 is one of the brightest Se.yfert galaxies on the sky at 100 keV, but is completely absorbed below 10 keV, implying an optical depth of the absorber to electron scattering of a few; its absorption column is probably the largest which still allows a direct view of the nucleus at hard X-ray energies. Our observations of it with the Rossi X-ray Timing Explorer (RXTE) satellite confirm the large absorption, which for a simple phenomenological fit using an absorber with Solar abundances implies a column of 4.5(sup 0.4, sub -0.4) x 10(exp 24) /sq cm. Using a a more realistic scenario (requiring Monte Carlo modeling of the scattering), we infer the optical depth to Thomson scattering of approximately 2.4. If such a scattering medium were to subtend a large solid angle from the nucleus, it should smear out any intrinsic hard X-ray variability on time scales shorter than the light travel time through it. The rapid (with a time scale of approximately a day) hard X-ray variability of NGC 4945 we observed with the RXTE implies that the bulk of the extreme absorption in this object does not originate in a parsec-size, geometrically thick molecular torus. Limits on the amount of scattered flux require that the optically thick material on parsec scales must be rather geometrically thin, subtending a half-angle < 10 deg. This is only marginally consistent with the recent determinations of the obscuring column in hard X-rays, where only a quarter of Seyfert 2s have columns which are optically thick, and presents a problem in accounting for the Cosmic X-ray Background primarily with AGN possessing the geometry as that inferred by us. The small solid angle of the obscuring material, together with the black hole mass (of approximately 1.4 x 10(exp 6) solar mass) from megamaser measurements. allows a robust determination of the source luminosity, which in turn implies that the source radiates at approximately 10% of the Eddington limit.

Development of a compact wearable pneumatic drive unit for a ventricular assist device.

Science.gov (United States)

Homma, Akihiko; Taenaka, Yoshiyuki; Tatsumi, Eisuke; Akagawa, Eiki; Lee, Hwansung; Nishinaka, Tomohiro; Takewa, Yoshiaki; Mizuno, Toshihide; Tsukiya, Tomonori; Kakuta, Yukihide; Katagiri, Nobumasa; Shimosaki, Isao; Hamada, Shigeru; Mukaibayashi, Hiroshi; Iwaoka, Wataru

2008-01-01

The purpose of this study was to develop a compact wearable pneumatic drive unit for a ventricular assist device (VAD). This newly developed drive unit, 20 x 8.5 x 20 cm in size and weighing approximately 1.8 kg, consists of a brushless DC motor, noncircular gears, a crankshaft, a cylinder-piston, and air pressure regulation valves. The driving air pressure is generated by the reciprocating motion of the piston and is controlled by the air pressure regulation valves. The systolic ratio is determined by the noncircular gears, and so is fixed for a given configuration. As a result of an overflow-type mock circulation test, a drive unit with a 44% systolic ratio connected to a Toyobo VAD blood pump with a 70-ml stroke volume achieved a pump output of more than 7 l/min at 100 bpm against a 120 mmHg afterload. Long-term animal tests were also performed using drive units with systolic ratios of 45% and 53% in two Holstein calves weighing 62 kg and 74 kg; the tests were terminated on days 30 and 39, respectively, without any malfunction. The mean aortic pressure, bypass flow, and power consumption for the first calf were maintained at 90 x 13 mmHg, 3.9 x 0.9 l/min, and 12 x 1 W, and those for the second calf were maintained at 88 x 13 mmHg, 5.0 x 0.5 l/min, and 16 x 2 W, respectively. These results indicate that the newly developed drive unit may be used as a wearable pneumatic drive unit for the Toyobo VAD blood pump.

DUAL-STAGE RECONNECTION DURING SOLAR FLARES OBSERVED IN HARD X-RAY

International Nuclear Information System (INIS)

Xu Yan; Jing Ju; Wang Haimin; Cao Wenda

2010-01-01

In this Letter, we present hard X-ray (HXR) observation by the Reuven Ramaty High Energy Solar Spectroscopic Imager of the 2003 October 29 X10 flare. Two pairs of HXR conjugate footpoints have been identified during the early impulsive phase. This geometric configuration is very much in the manner predicted by the 'tether-cutting' scenario first proposed by Moore and Roumeliotis. The HXR light curves show that the outer pair of footpoints disappeared much faster than the other pair. This temporal behavior further confirms that this event is a good example of the 'tether-cutting' model. In addition, we reconstructed a three-dimensional magnetic field based on the nonlinear force-free extrapolation and found that each pair of HXR footpoints were indeed linked by corresponding magnetic field lines.

Evidence for two hard X-ray components in double power-law fits to the 1980 June 7 flare

Science.gov (United States)

Smith, Dean F.; Orwig, Larry E.

1988-01-01

The June 7, 1980 flare at 0312 UT was analyzed with double power-law fits on the basis of SMM hard X-ray burst spectrometer data. The flare is found to consist of seven peaks of characteristic time scale of about 8 sec followed by seven valleys which may contain significant peak components because of overlap. It is suggested that the possibility of thermal spectra for the peaks is unlikely. An investigation of the double power-law parameters through the third and fourth peaks revealed a hysteresis effect in the fourth peak. The present results have been interpreted in terms of a trap plus precipitation model.

Experimental study of hard X-rays emitted from meter-scale positive discharges in air

NARCIS (Netherlands)

P.O. Kochkin (Pavlo); C.V. Nguyen; A. van Deursen (Arie); U. M. Ebert (Ute)

2012-01-01

textabstractWe investigate structure and evolution of long positive spark breakdown; and we study at which stage pulses of hard x-rays are emitted. Positive high-voltage pulses of standardized lightning impulse wave form of about 1 MV were applied to about 1 m of ambient air. The discharge evolution

Status of the Nanoscopium Scanning Hard X-ray Nanoprobe Beamline of Synchrotron Soleil

Science.gov (United States)

Somogyi, A.; Kewish, C. M.; Ribbens, M.; Moreno, T.; Polack, F.; Baranton, G.; Desjardins, K.; Samama, J. P.

2013-10-01

The Nanoscopium 155 m-long scanning hard X-ray nanoprobe beamline of Synchrotron Soleil (St Aubin, France) is dedicated to quantitative multi-modal 2D/3D imaging. The beamline aims to reach down to 30 nm spatial resolution in the 5-20 keV energy range. Two experimental stations working in consecutive operation mode will be dedicated to coherent diffractive imaging and scanning X-ray nanoprobe techniques. The beamline is in the construction phase, the first user experiments are expected in 2014. The main characteristics of the beamline and an overview of its status are given in this paper.

Status of the Nanoscopium Scanning Hard X-ray Nanoprobe Beamline of Synchrotron Soleil

International Nuclear Information System (INIS)

Somogyi, A; Kewish, C M; Ribbens, M; Moreno, T; Polack, F; Baranton, G; Desjardins, K; Samama, J P

2013-01-01

The Nanoscopium 155 m-long scanning hard X-ray nanoprobe beamline of Synchrotron Soleil (St Aubin, France) is dedicated to quantitative multi-modal 2D/3D imaging. The beamline aims to reach down to 30 nm spatial resolution in the 5–20 keV energy range. Two experimental stations working in consecutive operation mode will be dedicated to coherent diffractive imaging and scanning X-ray nanoprobe techniques. The beamline is in the construction phase, the first user experiments are expected in 2014. The main characteristics of the beamline and an overview of its status are given in this paper

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

Science.gov (United States)

Robin, David

2002-04-01

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

Time resolved, 2-D hard X-ray imaging of relativistic electron-beam target interactions on ETA-II

International Nuclear Information System (INIS)

Crist, C.E.; Sampayan, S.; Westenskow, G.; Caporaso, G.; Houck, T.; Weir, J.; Trimble, D.; Krogh, M.

1998-01-01

Advanced radiographic applications require a constant source size less than 1 mm. To study the time history of a relativistic electron beam as it interacts with a bremsstrahlung converter, one of the diagnostics they use is a multi-frame time-resolved hard x-ray camera. They are performing experiments on the ETA-II accelerator at Lawrence Livermore National Laboratory to investigate details of the electron beam/converter interactions. The camera they are using contains 6 time-resolved images, each image is a 5 ns frame. By starting each successive frame 10 ns after the previous frame, they create a 6-frame movie from the hard x-rays produced from the interaction of the 50-ns electron beam pulse

The High Energy X-ray Spectrum of 4U1700-37 Observed from OSO-8

Science.gov (United States)

Dolan, J. F.; Coe, M. J.; Crannell, C. J.; Dennis, B. R.; Frost, K. J.; Maurer, G. S.; Orwig, L. E.

1979-01-01

The most intense hard X-ray source in the confused region in Scorpius is identified as 4U1700-37. The 3.4-day modulation is seen above 20 keV with the intensity during eclipse being consistent with zero flux. The photon-number spectrum from 20 to 150 keV is well represented by a single power law with a photo-number spectral index of -2.77 + or - 0.35 or by a thermal bremsstrahlung spectrum with kT = 27 96.8-min X-ray modulation previously reported at lower energies. Despite the difficulties in reconciling both the lack of periodic modulation in the emitted X-radiation and the orbital dynamics of the system with theories of the evolution and physical properties of neutron stars, the observed properties of 4U1700-37 are all consistent with the source being a spherically accreting neutron star rather than a black hole.

First hard X-ray detection of the non-thermal emission around the Arches cluster: morphology and spectral studies with NuSTAR

DEFF Research Database (Denmark)

Krivonos, Roman A.; Tomsick, John A.; Bauer, Franz E.

2014-01-01

The Arches cluster is a young, densely packed massive star cluster in our Galaxy that shows a high level of star formation activity. The nature of the extended non-thermal X-ray emission around the cluster remains unclear. The observed bright Fe Ku line emission at 6.4 keV from material that is n......The Arches cluster is a young, densely packed massive star cluster in our Galaxy that shows a high level of star formation activity. The nature of the extended non-thermal X-ray emission around the cluster remains unclear. The observed bright Fe Ku line emission at 6.4 keV from material...... and spectrum. The spatial distribution of the hard X-ray emission is found to be consistent with the broad region around the cluster where the 6.4 keV line is observed. The interpretation of the hard X-ray emission within the context of the X-ray reflection model puts a strong constraint on the luminosity...... of the possible illuminating hard X-ray source. The properties of the observed emission are also in broad agreement with the low-energy cosmic-ray proton excitation scenario....