Science.gov

Sample records for resolved synchrotron light

  1. Time-resolved far-infrared experiments at the National Synchrotron Light Source. Final report

    SciTech Connect

    Tanner, D.B.; Reitze, D.H.; Carr, G.L.

    1999-10-12

    A facility for time-resolved infrared and far-infrared spectroscopy has been built and commissioned at the National Synchrotron Light Source. This facility permits the study of time dependent phenomena over a frequency range from 2-8000cm{sup {minus}1} (0.25 meV-1 eV). Temporal resolution is approximately 200 psec and time dependent phenomena in the time range out to 100 nsec can be investigated.

  2. Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources

    PubMed Central

    Rutherford, Michael E.; Chapman, David J.; White, Thomas G.; Drakopoulos, Michael; Rack, Alexander; Eakins, Daniel E.

    2016-01-01

    The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits). PMID:27140147

  3. Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources.

    PubMed

    Rutherford, Michael E; Chapman, David J; White, Thomas G; Drakopoulos, Michael; Rack, Alexander; Eakins, Daniel E

    2016-05-01

    The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits). PMID:27140147

  4. National Synchrotron Light Source

    ScienceCinema

    None

    2010-01-08

    A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

  5. National Synchrotron Light Source

    SciTech Connect

    2009-03-10

    A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

  6. National Synchrotron Light Source

    ScienceCinema

    BNL

    2009-09-01

    A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

  7. The DELTA Synchrotron Light Interferometer

    SciTech Connect

    Berges, U.

    2004-05-12

    Synchrotron radiation sources like DELTA, the Dortmund Electron Accelerator, a third generation synchrotron light source, need an optical monitoring system to measure the beam size at different points of the ring with high resolution and accuracy. These measurements also allow an investigation of the emittance of the storage ring, an important working parameter for the efficiency of working beamlines with experiments using the synchrotron radiation. The resolution limits of the different types of optical synchrotron light monitors at DELTA are investigated. The minimum measurable beamsize with the normal synchrotron light monitor using visible light at DELTA is about 80 {mu}m. Due to this a synchrotron light interferometer was built up and tested at DELTA. The interferometer uses the same beamline in the visible range. The minimum measurable beamsize is with about 8 {mu}m one order of magnitude smaller. This resolution is sufficient for the expected small vertical beamsizes at DELTA. The electron beamsize and emittance were measured with both systems at different electron beam energies of the storage ring. The theoretical values of the present optics are smaller than the measured emittance. So possible reasons for beam movements are investigated.

  8. National Synchrotron Light Source II

    SciTech Connect

    Steve Dierker

    2008-03-12

    The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

  9. National Synchrotron Light Source II

    ScienceCinema

    Steve Dierker

    2010-01-08

    The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

  10. Candle Synchrotron Light Source Project

    NASA Astrophysics Data System (ADS)

    Tsakanov, V. M.

    CANDLE - Center for the Advancement of Natural Discoveries using Light Emission - is a 3 GeV energy synchrotron light facility project in the Republic of Armenia. The main design features of the new facility are given. The results of the beam physics study in the future facility is overviewed including the machine impedance, single and multi-bunch instabilities, ion trapping and beam lifetime. The preliminary list of first group beamlines is discussed.

  11. Molecular Chemical Structure of Barley Proteins Revealed by Ultra-Spatially Resolved Synchrotron Light Sourced FTIR Microspectroscopy: Comparison of Barley Varieties

    SciTech Connect

    Yu,P.

    2007-01-01

    Barley protein structure affects the barley quality, fermentation, and degradation behavior in both humans and animals among other factors such as protein matrix. Publications show various biological differences among barley varieties such as Valier and Harrington, which have significantly different degradation behaviors. The objectives of this study were to reveal the molecular structure of barley protein, comparing various varieties (Dolly, Valier, Harrington, LP955, AC Metcalfe, and Sisler), and quantify protein structure profiles using Gaussian and Lorentzian methods of multi-component peak modeling by using the ultra-spatially resolved synchrotron light sourced Fourier transform infrared microspectroscopy (SFTIRM). The items of the protein molecular structure revealed included protein structure {alpha}-helices, {beta}-sheets, and others such as {beta}-turns and random coils. The experiment was performed at the National Synchrotron Light Source in Brookhaven National Laboratory (BNL, US Department of Energy, NY). The results showed that with the SFTIRM, the molecular structure of barley protein could be revealed. Barley protein structures exhibited significant differences among the varieties in terms of proportion and ratio of model-fitted {alpha}-helices, {beta}-sheets, and others. By using multi-component peaks modeling at protein amide I region of 1710-1576 cm{sup -1}, the results show that barley protein consisted of approximately 18-34% of {alpha}-helices, 14-25% of {beta}-sheets, and 44-69% others. AC Metcalfe, Sisler, and LP955 consisted of higher (P < 0.05) proportions of {alpha}-helices (30-34%) than Dolly and Valier ({alpha}-helices 18-23%). Harrington was in between which was 25%. For protein {beta}-sheets, AC Metcalfe, and LP955 consisted of higher proportions (22-25%) than Dolly and Valier (13-17%). Different barley varieties contained different {alpha}-helix to {beta}-sheet ratios, ranging from 1.4 to 2.0, although the difference were

  12. The Brazilian Synchrotron Light Source

    SciTech Connect

    Brum, J. A.; Tavares, P. F.

    2007-01-19

    The Brazilian Synchrotron Light Laboratory has been operating the only light source in the southern hemisphere since July 1997. During this period, approximately 28000 hours of beam time were delivered reaching more than 1000 users per year from all over Brazil as well as from 10 other countries. In this paper, we briefly recall the history of the project and describe the present configuration of the machine and associated instrumentation, focusing on improvements and upgrades of the various light source subsystems and beamlines implemented in recent years. Finally, we report on the use of the facility by the national and international scientific communities, its impact on the scientific and technological scene in Brazil and present perspectives for future improvements of the machine.

  13. National Synchrotron Light Source annual report 1988

    SciTech Connect

    Hulbert, S.; Lazarz, N.; Williams, G.

    1988-01-01

    This report discusses the experiment done at the National Synchrotron Light Source. Most experiments discussed involves the use of the x-ray beams to study physical properties of solid materials. (LSP)

  14. The Stanford Synchrotron Radiation Laboratory, 20 years of synchrotron light

    SciTech Connect

    Cantwell, K.

    1993-08-01

    The Stanford Synchrotron Radiation Laboratory (SSRL) is now operating as a fully dedicated light source with low emittance electron optics, delivering high brightness photon beams to 25 experimental stations six to seven months per year. On October 1, 1993 SSRL became a Division of the Stanford Linear Accelerator Center, rather than an Independent Laboratory of Stanford University, so that high energy physics and synchrotron radiation now function under a single DOE contract. The SSRL division of SLAC has responsibility for operating, maintaining and improving the SPEAR accelerator complex, which includes the storage ring and a 3 GeV injector. SSRL has thirteen x-ray stations and twelve VUV/Soft x-ray stations serving its 600 users. Recently opened to users is a new spherical grating monochromator (SGM) and a multiundulator beam line. Circularly polarized capabilities are being exploited on a second SGM line. New YB{sub 66} crystals installed in a vacuum double-crystal monochromator line have sparked new interest for Al and Mg edge studies. One of the most heavily subscribed stations is the rotation camera, which has been recently enhanced with a MAR imaging plate detector system for protein crystallography on a multipole wiggler. Under construction is a new wiggler-based structural molecular biology beam line with experimental stations for crystallography, small angle scattering and x-ray absorption spectroscopy. Plans for new developments include wiggler beam lines and associated facilities specialized for environmental research and materials processing.

  15. Chopper system for time resolved experiments with synchrotron radiation

    SciTech Connect

    Cammarata, Marco; Eybert, Laurent; Ewald, Friederike; Reichenbach, Wolfgang; Wulff, Michael; Anfinrud, Philip; Schotte, Friedrich; Plech, Anton; Kong, Qingyu; Lorenc, Maciej; Lindenau, Bernd; Raebiger, Juergen; Polachowski, Stephan

    2009-01-15

    A chopper system for time resolved pump-probe experiments with x-ray beams from a synchrotron is described. The system has three parts: a water-cooled heatload chopper, a high-speed chopper, and a millisecond shutter. The chopper system, which is installed in beamline ID09B at the European Synchrotron Radiation Facility, provides short x-ray pulses for pump-probe experiments with ultrafast lasers. The chopper system can produce x-ray pulses as short as 200 ns in a continuous beam and repeat at frequencies from 0 to 3 kHz. For bunch filling patterns of the synchrotron with pulse separations greater than 100 ns, the high-speed chopper can isolate single 100 ps x-ray pulses that are used for the highest time resolution. A new rotor in the high-speed chopper is presented with a single pulse (100 ps) and long pulse (10 {mu}s) option. In white beam experiments, the heatload of the (noncooled) high-speed chopper is lowered by a heatload chopper, which absorbs 95% of the incoming power without affecting the pulses selected by the high speed chopper.

  16. Status of the Synchrotron Light Source DELTA

    SciTech Connect

    Berges, U.; Sternemann, C.; Tolan, M.; Westphal, C.; Weis, T.; Wille, K.

    2007-01-19

    The Dortmund Electron Accelerator DELTA, a 1.5 GeV synchrotron light source located at University of Dortmund, is operated for 3000 h per year including 2000 h beam time for synchrotron radiation use and 1000 h for machine physics, optimisation and maintenance. The status of the synchrotron light source is presented with emphasis on the operation, commissioning and installation of beamlines and insertion devices. The soft X-ray undulator beamlines provide photon energies between 5 to 400 eV (U250) and 55 and 1500 eV (U55), respectively. One dipole beamline covers soft X-rays between 6 to 200 eV, and a second dipole beamline is used without a monochromator at 2.2 keV critical energy of the dipole spectrum. For photons in the hard X-ray regime, a superconducting asymmetric wiggler (SAW) with a field of 5.3 T and 7.9 keV critical energy was installed, providing circularly polarized X-rays in the range of 2 to 30 keV. Due to its broad radiation fan, three beamlines are simultaneously served. The first SAW-beamline with an energy range between 4 to 30 keV is in full operation, the second is under commissioning, serving the energy range between 2 to 30 keV. The third SAW beamline is near completion, additional dipole beamlines are under construction.

  17. Synchrotron Light Interferometry at Jefferson Lab

    SciTech Connect

    Arne Freyberger; Pavel Chevtsov; Anthony Day; William Hicks

    2004-07-01

    The hyper-nuclear physics program at JLAB requires an upper limit on the RMS momentum spread of {delta}p/p < 3 x 10{sup -5}. The momentum spread is determined by measuring the beam width at a dispersive location (D {approx} 4m) in the transport line to the experimental halls. Ignoring the epsilon-beta contribution to the intrinsic beam size, this momentum spread corresponds to an upper bound on the beam width of {sigma}{sub beam} < 120 {micro}m. Typical techniques to measure and monitor the beam size are either invasive or do not have the resolution to measure such small beam sizes. Using interferometry of the synchrotron light produced in the dispersive bend, the resolution of the optical system can be made very small. The non-invasive nature of this measurement allows continuous monitoring of the momentum spread. Two synchrotron light interferometers have been built and installed at JLAB, one each in the Hall-A and Hall-C transport lines. The devices operate over a beam current range from 20 {micro}A to 120 {micro}A and have a spatial resolution of 10um. The structure of the interferometers, the experience gained during its installation, beam measurements and momentum spread stability are presented. The dependence of the measured momentum spread on beam current will be presented.

  18. Status Of The Synchrotron Light Source DELTA

    SciTech Connect

    Berges, U.; Friedl, J.; Hartmann, P.; Schirmer, D.; Schmidt, G.; Sternemann, C.; Tolan, M.; Weis, T.; Westphal, C.; Wille, K.

    2004-05-12

    The Dortmund Electron Accelerator DELTA, located at the University of Dortmund, changed its scope during the last years into a 1.5 GeV synchrotron light source. DELTA is now operated for 3000 h per year including 2000 h dedicated beam time for synchrotron radiation use and 1000 h for machine physics, optimization and maintenance. The status of the accelerator complex is presented together with the beam operation, the installation and commissioning of beamlines and insertion devices. To serve user demands of photon energies up to more than 10 keV a 5.3 T superconducting asymmetric multipole wiggler (SAW) with a critical energy of 7.9 keV has been installed serving three beamlines in the hard X-ray regime with also circular polarization. Two undulator beamlines for photon energies between 5 and 400 eV (U250) and between 55 and 1500 eV (U55) and several dipole beamlines up to 200 eV are under operation. The construction and operation of the different beamlines is done by various universities and laboratories in Nordrhein-Westfalen.

  19. Laue diffraction protein crystallography at the National Synchrotron Light Source

    SciTech Connect

    Getzoff, E.D.; McRee, D.; Jones, K.W.; Spanne, P.; Sweet, R.M.; Moffat, K.; Ng, K.; Rivers, M.L.; Schildkamp, W.; Teng, T.Y.; Singer, P.T.; Westbrook, E.M.

    1992-12-31

    A new facility for the study of protein crystal structure using Laue diffraction has been established at the X26 beam line of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The characteristics of the beam line and diffraction apparatus are described. Selected results of some of the initial experiments are discussed briefly by beam line users to illustrate the scope of the experimental program. Because the Laue method permits the recording of large data sets in a single shot, one goal in establishing this facility has been to develop the means to study time-resolved structures within protein crystals. Systems being studied include: the reactions catalyzed by trypsin; photolysis of carbonmonoxy myoglobin; and the photocycle of photoactive yellow protein.

  20. Laue diffraction protein crystallography at the National Synchrotron Light Source

    SciTech Connect

    Getzoff, E.D.; McRee, D. ); Jones, K.W.; Spanne, P.; Sweet, R.M. ); Moffat, K.; Ng, K.; Rivers, M.L.; Schildkamp, W.; Teng, T.Y. ); Singer, P.T.; Westbrook, E.M. )

    1992-01-01

    A new facility for the study of protein crystal structure using Laue diffraction has been established at the X26 beam line of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The characteristics of the beam line and diffraction apparatus are described. Selected results of some of the initial experiments are discussed briefly by beam line users to illustrate the scope of the experimental program. Because the Laue method permits the recording of large data sets in a single shot, one goal in establishing this facility has been to develop the means to study time-resolved structures within protein crystals. Systems being studied include: the reactions catalyzed by trypsin; photolysis of carbonmonoxy myoglobin; and the photocycle of photoactive yellow protein.

  1. Time-resolved structural studies at synchrotrons and X-ray free electron lasers: opportunities and challenges

    PubMed Central

    Neutze, Richard; Moffat, Keith

    2012-01-01

    X-ray free electron lasers (XFELs) are potentially revolutionary X-ray sources because of their very short pulse duration, extreme peak brilliance and high spatial coherence, features that distinguish them from today’s synchrotron sources. We review recent time-resolved Laue diffraction and time-resolved wide angle X-ray scattering (WAXS) studies at synchrotron sources, and initial static studies at XFELs. XFELs have the potential to transform the field of time-resolved structural biology, yet many challenges arise in devising and adapting hardware, experimental design and data analysis strategies to exploit their unusual properties. Despite these challenges, we are confident that XFEL sources are poised to shed new light on ultrafast protein reaction dynamics. PMID:23021004

  2. Fluorescence imaging and time-resolved spectroscopy of steroid using confocal synchrotron radiation microscopy

    NASA Astrophysics Data System (ADS)

    Gerritsen, Hans C.; van der Oord, C. J. R.; Levine, Yehudi K.; Munro, Ian H.; Jones, Gareth R.; Shaw, D. A.; Rommerts, Fokko F.

    1994-08-01

    The Confocal Synchrotron Radiation Microscope at Daresbury was used in a study of the transport and distribution of the steroid Coumestrol in single Leydig cells. The broad spectrum of synchrotron radiation in combination with UV compatible microscope optics affords the extension of confocal microscopy from the visible to the UV region down to about 200 nm. Consequently fluorescent molecules with absorption bands in the UV can be imaged. In addition the pulsed nature of the light source allows us to perform time-resolved fluorescence spectroscopy experiments on microscopic volumes. Coumestrol is a naturally fluorescing plant steroid exhibiting estrogenic activity. In physiological environments it has an absorption peak in the UV at 340 nm and it emits around 440 nm. First results indicate that the Coumestrol transport through the cell membrane is diffusion limited. The weak fluorescence observed in the nuclei of the Leydig cells may be due to fluorescence quenching arising from the interaction of the Coumesterol with nuclear components. However, micro-volume time-resolved fluorescence spectroscopy experiments on cell nuclei have revealed the same decay behavior for Coumesterol in both the cytoplasm and nucleus of the cells.

  3. National Synchrotron Light Source 2008 Activity Report

    SciTech Connect

    Nasta,K.

    2009-05-01

    Funded by the U.S. Department of Energy's Office of Basic Energy Sciences, the National Synchrotron Light Source (NSLS) is a national user facility that operates two electron storage rings: X-Ray (2.8 GeV, 300 mA) and Vacuum Ultraviolet (VUV) (800 mev, 1.0A). These two rings provide intense light spanning the electromagnetic spectrum -- from very long infrared rays to ultraviolet light and super-short x-rays -- to analyze very small or highly dilute samples. The properties of this light, and the specially designed experimental stations, called beamlines, allow scientists in many diverse disciplines of research to perform experiments not possible at their own laboratories. Each year, about 2,200 scientists from more than 400 universities and companies use the NSLS for research in such diverse fields as biology, physics, chemistry, geology, medicine, and environmental and materials sciences. For example, researchers have used the NSLS to examine the minute details of computer chips, decipher the structures of viruses, probe the density of bone, determine the chemical composition of moon rocks, and reveal countless other mysteries of science. The facility has 65 operating beamlines, with 51 beamlines on the X-Ray Ring and 14 beamlines on the VUV-Infrared Ring. It runs seven days a week, 24 hours a day throughout the year, except during periods of maintenance and studies. Researchers are not charged for beam time, provided that the research results are published in open literature. Proprietary research is conducted on a full-cost-recovery basis. With close to 1,000 publications per year, the NSLS is one of the most prolific scientific facilities in the world. Among the many accolades given to its users and staff, the NSLS has won nine R&D 100 Awards for innovations ranging from a closed orbit feedback system to the first device able to focus a large spread of high-energy x-rays. In addition, a visiting NSLS researcher shared the 2003 Nobel Prize in Chemistry for work

  4. Time-resolved materials science opportunities using synchrotron x-ray sources

    SciTech Connect

    Larson, B.C.; Tischler, J.Z.

    1995-06-01

    The high brightness, high intensity, and pulsed time-structure of synchrotron sources provide new opportunities for time-resolved x-ray diffraction investigations. With third generation synchrotron sources coming on line, high brilliance and high brightness are now available in x-ray beams with the highest flux. In addition to the high average flux, the instantaneous flux available in synchrotron beams is greatly enhanced by the pulsed time structure, which consists of short bursts of x-rays that are separated by {approximately}tens to hundreds of nanoseconds. Time-resolved one- and two-dimensional position sensitive detection techniques that take advantage of synchrotron radiation for materials science x-ray diffraction investigations are presented, and time resolved materials science applications are discussed in terms of recent diffraction and spectroscopy results and materials research opportunities.

  5. National Synchrotron Light Source 2010 Activity Report

    SciTech Connect

    Rowe, M.; Snyder, K. J.

    2010-12-29

    This is a very exciting period for photon sciences at Brookhaven National Laboratory. It is also a time of unprecedented growth for the Photon Sciences Directorate, which operates the National Synchrotron Light Source (NSLS) and is constructing NSLS-II, both funded by the Department of Energy's Office of Science. Reflecting the quick pace of our activities, we chose the theme 'Discovery at Light Speed' for the directorate's 2010 annual report, a fiscal year bookended by October 2009 and September 2010. The year began with the news that NSLS users Venki Ramakrishnan of Cambridge University (also a former employee in Brookhaven's biology department) and Thomas A. Steitz of Yale University were sharing the 2009 Nobel Prize in Chemistry with Ada E. Yonath of the Weizmann Institute of Science. Every research project has the potential for accolades. In 2010, NSLS users and staff published close to 900 papers, with about 170 appearing in premiere journals. Those are impressive stats for a facility nearly three decades old, testament to the highly dedicated team keeping NSLS at peak performance and the high quality of its user community. Our NSLS users come from a worldwide community of scientists using photons, or light, to carry out research in energy and environmental sciences, physics, materials science, chemistry, biology and medicine. All are looking forward to the new capabilities enabled by NSLS-II, which will offer unprecedented resolution at the nanoscale. The new facility will produce x-rays more than 10,000 times brighter than the current NSLS and host a suite of sophisticated instruments for cutting-edge science. Some of the scientific discoveries we anticipate at NSLS-II will lead to major advances in alternative energy technologies, such as hydrogen and solar. These discoveries could pave the way to: (1) catalysts that split water with sunlight for hydrogen production; (2) materials that can reversibly store large quantities of electricity or hydrogen; (3

  6. Status of the National Synchrotron Light Source

    SciTech Connect

    Galayda, J.N.

    1983-01-01

    The status and performance of the NSLS 700 MeV ring and 2.5 GeV ring are described. Emphasis is placed on properties of the stored beam pertinent to synchrotron radiation production, the factors determining these properties, and efforts to improve performance of the rings.

  7. Spin polarized energy-resolved photoemission from Ni(111) using synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Gudat, W.; Kisker, E.; Kuhlmann, E.; Campagna, M.

    1981-03-01

    We report on the first energy-resolved (retarding field mode) spin polarized photoemission measurement from a Ni(111) single crystal using synchrotron radiation from the ACO storage ring at LURE(ORSAY) It is shown that exchange effects can be detected for electron states well below the Fermi energy and that spin polarized, constant-initial-state spectroscopy of ferromagnets using synchrotron radiation is feasible.

  8. National Synchrotron Light Source safety-analysis report

    SciTech Connect

    Batchelor, K.

    1982-07-01

    This document covers all of the safety issues relating to the design and operation of the storage rings and injection system of the National Synchrotron Light Source. The building systems for fire protection, access and egress are described together with air and other gaseous control or venting systems. Details of shielding against prompt bremstrahlung radiation and synchrotron radiation are described and the administrative requirements to be satisfied for operation of a beam line at the facility are given.

  9. NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 2004

    SciTech Connect

    MILLER,L.

    2005-05-01

    for the environmental science community, is also very important, as it will help to satisfy the large over subscription rate for this technique at the NSLS. Two other important upgrades that were initiated this past year are the replacement of the X25 wiggler with an undulator and the construction of the X9 undulator beamline for small-angle scattering, with an emphasis on nanoscience research. Another key activity that will benefit all users was the restoration of the x-ray ring lattice symmetry, which reduced the horizontal emittance and made the operational lattice more robust. Similarly, all users will benefit from the introduction of the PASS (Proposal Allocation Safety Scheduling) system this past year, which has greatly improved the process of proposal submission, review, allocation, and scheduling. This coming year we will work to add Rapid Access to the capabilities of PASS. Overall, the success of these and the many other projects that space does not permit listing is a testament to the dedication, hard work, and skill of the NSLS staff. Safety has always been an important issue at a large, complex scientific facility like the NSLS and in 2004 it received renewed attention. Safety is our highest priority and we spent a great deal of time reviewing and refining our safety practices and procedures. A new 'Safety Highlights' web page was created for safety news, and a large number of safety meetings and discussions were held. These reviews and meetings generated many ideas on how the NSLS might improve its safety practices, and we are committed to putting these in place and improving our already very good safety program. We had no lost-time accidents in 2004, which is a notable accomplishment. Our goal is to be best in class and I'm confident that by working together we can achieve that status. Several activities took place this past year to advance our proposal to replace the NSLS with a new National Synchrotron Light Source-II facility. These included a major

  10. Time-resolved photoelectron spectroscopy using synchrotron radiation time structure.

    PubMed

    Bergeard, N; Silly, M G; Krizmancic, D; Chauvet, C; Guzzo, M; Ricaud, J P; Izquierdo, M; Stebel, L; Pittana, P; Sergo, R; Cautero, G; Dufour, G; Rochet, F; Sirotti, F

    2011-03-01

    Synchrotron radiation time structure is becoming a common tool for studying dynamic properties of materials. The main limitation is often the wide time domain the user would like to access with pump-probe experiments. In order to perform photoelectron spectroscopy experiments over time scales from milliseconds to picoseconds it is mandatory to measure the time at which each measured photoelectron was created. For this reason the usual CCD camera-based two-dimensional detection of electron energy analyzers has been replaced by a new delay-line detector adapted to the time structure of the SOLEIL synchrotron radiation source. The new two-dimensional delay-line detector has a time resolution of 5 ns and was installed on a Scienta SES 2002 electron energy analyzer. The first application has been to characterize the time of flight of the photoemitted electrons as a function of their kinetic energy and the selected pass energy. By repeating the experiment as a function of the available pass energy and of the kinetic energy, a complete characterization of the analyzer behaviour in the time domain has been obtained. Even for kinetic energies as low as 10 eV at 2 eV pass energy, the time spread of the detected electrons is lower than 140 ns. These results and the time structure of the SOLEIL filling modes assure the possibility of performing pump-probe photoelectron spectroscopy experiments with the time resolution given by the SOLEIL pulse width, the best performance of the beamline and of the experimental station. PMID:21335912

  11. Research by industry at the National Synchrotron Light Source

    SciTech Connect

    1995-05-01

    The world`s foremost facility for research using x-rays and ultraviolet and infrared radiation, is operated by the National Synchrotron Light Source dept. This pamphlet described the participating research teams that built most of the beam lines, various techniques for studying materials, treatment of materials, and various industrial research (catalysis, pharmaceuticals, etc.).

  12. Apparatus and Techniques for Time-resolved Synchrotron X-ray Diffraction using Diamond Anvil Cells

    NASA Astrophysics Data System (ADS)

    Smith, J.; Sinogeikin, S. V.; Lin, C.; Rod, E.; Bai, L.; Shen, G.

    2015-12-01

    Complementary advances in synchrotron sources, x-ray optics, area detectors, and sample environment control have recently made possible many time-resolved experimental techniques for studying materials at extreme pressure and temperature conditions. The High Pressure Collaborative Access Team (HPCAT) at the Advanced Photon Source has made a sustained effort to assemble a powerful collection of high-pressure apparatus for time-resolved research, and considerable time has been invested in developing techniques for collecting high-quality time-resolved x-ray scattering data. Herein we present key aspects of the synchrotron beamline and ancillary equipment, including source considerations, rapid (de)compression apparatus, high frequency imaging detectors, and software suitable for processing large volumes of data. A number of examples are presented, including fast equation of state measurements, compression rate dependent synthesis of metastable states in silicon and germanium, and ultrahigh compression rates using a piezoelectric driven diamond anvil cell.

  13. DAFNE-Light INFN-LNF Synchrotron Radiation Facility

    SciTech Connect

    Balerna, A.; Cestelli-Guidi, M.; Cimino, R.; Commisso, M.; Grilli, A.; Pietropaoli, M.; Raco, A.; Sciarra, V.; Tullio, V.; Viviani, G.; De Sio, A.; Gambicorti, L.; Hampai, D.; Pace, E.

    2010-06-23

    DAFNE-Light is the Synchrotron Radiation Facility at the INFN-Frascati National Laboratory (Rome, Italy). Three beamlines are operational, using in parasitic and dedicated mode the intense photon emission of DAFNE, a 0.51 GeV storage ring with a routinely circulating electron current higher than 1 Ampere. Two of these beamlines--the soft x-ray (DXR1) and UV (DXR2)--use one of the DAFNE wiggler magnets as synchrotron radiation source, while the third beamline SINBAD (Synchrotron Infrared Beamline At DAFNE) collects the radiation from a bending magnet. New XUV bending magnet beamlines are nowadays under construction and the low energy one (35-200 eV) will be ready for commissioning by the end of 2009. A presentation of the facility will be given together with some recent scientific results achieved at SINBAD and DXR1 beamlines.

  14. Chemical Imaging of Biological Tissue with Synchrotron Infrared Light

    SciTech Connect

    Miller,L.; Dumas, P.

    2006-01-01

    Fourier transform infrared micro-spectroscopy (FTIRM) and imaging (FTIRI) have become valuable techniques for examining the chemical makeup of biological materials by probing their vibrational motions on a microscopic scale. Synchrotron infrared (S-IR) light is an ideal source for FTIRM and FTIRI due to the combination of its high brightness (i.e., flux density), also called brilliance, and broadband nature. Through a 10-{mu}m pinhole, the brightness of a synchrotron source is 100-1000 times higher than a conventional thermal (globar) source. Accordingly, the improvement in spatial resolution and in spectral quality to the diffraction limit has led to a plethora of applications that is just being realized. In this review, we describe the development of synchrotron-based FTIRM, illustrate its advantages in many applications to biological systems, and propose some potential future directions for the technique.

  15. Synchrotron radiation as a light source in confocal microscopy of biological processes

    NASA Astrophysics Data System (ADS)

    Gerritsen, Hans C.; van der Oord, C. J. R.; Levine, Yehudi K.; Munro, Ian H.; Myring, Wendy J.; Shaw, D. A.; Rommerts, Fokko F.

    1992-04-01

    A novel confocal microscope is presented using the Daresbury Synchrotron Radiation source as its light source. The broad spectrum of synchrotron radiation in combination with the UV compatible microscope allows the extension of confocal microscopy from the visible to the UV region down to about 200 nm. It is envisaged that structures separated by about 70 nm can be resolved at a wavelength of 200 nm. In addition, the tunability of synchrotron radiation affords the selective excitation of any specific fluorescent molecule at the maximum of the absorption band. This avoids the restriction of working at fixed laser lines. A further advantage of using synchrotron radiation is the realization of multiwavelength excitation. Test results using laser systems in the visible and in the UV are presented. Fluorescence images of test targets using UV excitation reveal the superior resolution of the microscope. Furthermore, images of Leydig cells incubated with a fluorescent cholesterol derivative whose maximum of absorption is at 325 nm are shown. These images cannot be produced by conventional confocal laser microscopes. Finally, promising preliminary results obtained with synchrotron radiation are presented.

  16. First Beam Measurements with the LHC Synchrotron Light Monitors

    SciTech Connect

    Lefevre, Thibaut; Bravin, Enrico; Burtin, Gerard; Guerrero, Ana; Jeff, Adam; Rabiller, Aurelie; Roncarolo, Federico; Fisher, Alan; /SLAC

    2012-07-13

    The continuous monitoring of the transverse sizes of the beams in the Large Hadron Collider (LHC) relies on the use of synchrotron radiation and intensified video cameras. Depending on the beam energy, different synchrotron light sources must be used. A dedicated superconducting undulator has been built for low beam energies (450 GeV to 1.5 TeV), while edge and centre radiation from a beam-separation dipole magnet are used respectively for intermediate and high energies (up to 7 TeV). The emitted visible photons are collected using a retractable mirror, which sends the light into an optical system adapted for acquisition using intensified CCD cameras. This paper presents the design of the imaging system, and compares the expected light intensity with measurements and the calculated spatial resolution with a cross calibration performed with the wire scanners. Upgrades and future plans are also discussed.

  17. Microbeam, timing and signal-resolved studies of nuclear materials with synchrotron X-ray sources

    SciTech Connect

    Ice, Gene E; Specht, Eliot D

    2012-01-01

    The development of ultra-brilliant synchrotron X-ray sources enables characterization methods that are particularly important for nuclear materials. Here we discuss emerging synchrotron methods with unprecedented signal-to-noise, spatial and time resolution. Microprobe methods are discussed that extend virtually any X-ray characterization measurement to ultra-small sample volumes. This ability is critical to resolve heterogeneities in nuclear materials and for studies on volumes with vastly lower activity than are needed for traditional X-ray characterization. Specific methods discussed include microdiffraction for the characterization of local crystal structure and micro-spectroscopy techniques that allow for characterization of elemental distributions with sensitivity for daughter products, oxidation states and diffusion through buffer layers. Opportunities are also discussed that exploit the high brilliance and pulsed nature of synchrotron radiation to reduce backgrounds from sample radiation and to study materials dynamics.

  18. Field transients of coherent terahertz synchrotron radiation accessed via time-resolving and correlation techniques

    NASA Astrophysics Data System (ADS)

    Pohl, A.; Semenov, A.; Hübers, H.-W.; Hoehl, A.; Ries, M.; Wüstefeld, G.; Ulm, G.; Ilin, K.; Thoma, P.; Siegel, M.

    2016-03-01

    Decaying oscillations of the electric field in repetitive pulses of coherent synchrotron radiation in the terahertz frequency range was evaluated by means of time-resolving and correlation techniques. Comparative analysis of real-time voltage transients of the electrical response and interferograms, which were obtained with an ultrafast zero-bias Schottky diode detector and a Martin-Puplett interferometer, delivers close values of the pulse duration. Consistent results were obtained via the correlation technique with a pair of Golay Cell detectors and a pair of resonant polarisation-sensitive superconducting detectors integrated on one chip. The duration of terahertz synchrotron pulses does not closely correlate with the duration of single-cycle electric field expected for the varying size of electron bunches. We largely attribute the difference to the charge density oscillations in electron bunches and to the low-frequency spectral cut-off imposed by both the synchrotron beamline and the coupling optics of our detectors.

  19. Time-Resolved Structural Analysis of Cation Exchange Reactions in Birnessite Using Synchrotron XRD

    NASA Astrophysics Data System (ADS)

    Lopano, C. L.; Heaney, P. J.; Post, J. E.; Hanson, J. C.; Lee, Y.; Komarneni, S.

    2002-12-01

    Birnessite ((Na,Ca,Mn2+) Mn7O142.8H2O) is a layered Mn-oxide with a 7.2Å spacing between the Mn octahedral sheets. Since birnessite is an abundant phase in soils, desert varnishes, and ocean nodules, it plays a significant role in soil and groundwater chemistry. Experiments by Golden et al. (1986,1987) have demonstrated that Na-buserite (hydrated birnessite) readily exchanges Na+ for a variety of other cations, including K+, Mg2+, Ca2+, Ba2+, Ni2+, and Sr2+. In light of its high cation exchange capacity, birnessite is industrially important for ion and molecular sieves and cathodic materials. In addition, birnessite serves as a precursor in the synthesis of todorokite, which has a 3x3 tunnel structure and is used as an octahedral sieve. We monitored cation-exchange reactions in birnessite by time-resolved X-ray powder diffraction with a simple flow-through cell at the National Synchrotron Light Source. The flow-through cell was developed by Lee and Parise at SUNY-Stony Brook, and this work represents its first application to Mn oxides. A series of synthetic Na-birnessite samples were saturated with chloride solutions containing dissolved K+, Mg2+, and Ba2+, ranging from 0.1M to 0.001M. Powder X-ray diffraction patterns were collected every ~ 3 minutes. The synchrotron experiments revealed that complete cation exchange occurs within three hours, and significant modifications of the arrangements of interlayer cations and water molecules accompany the exchange. Specifically, the replacement of Na by Mg resulted in the continuous growth of a discrete buserite-like phase with a 10Å layer spacing, while replacement of Na by K and Ba retained the 7Å spacing. K replacement of Na resulted in gradually decreasing peak intensity and peak merging. The Ba exchange yielded an abrupt decrease in diffraction intensities followed by a more gradual lattice change over the last 2 hours. Rietveld analysis led to the first determination of the structure of Ba-birnessite in space

  20. Time Resolved Detection of Infrared Synchrotron Radiation at DA{phi}NE

    SciTech Connect

    Bocci, A.; Marcelli, A.; Drago, A.; Guidi, M. Cestelli; Pace, E.; Piccinini, M.; Sali, D.; Morini, P.

    2007-01-19

    Synchrotron radiation is characterized by a very wide spectral emission from IR to X-ray wavelengths and a pulsed structure that is a function of the source time structure. In a storage ring, the typical temporal distance between two bunches, whose duration is a few hundreds of picoseconds, is on the nanosecond scale. Therefore, synchrotron radiation sources are a very powerful tools to perform time-resolved experiments that however need extremely fast detectors. Uncooled IR devices optimized for the mid-IR range with sub-nanosecond response time, are now available and can be used for fast detection of intense IR sources such as synchrotron radiation storage rings. We present here different measurements of the pulsed synchrotron radiation emission at DA{phi}NE (Double Annular {phi}-factory for Nice Experiments), the collider of the Laboratori Nazionali of Frascati (LNF) of the Istituto Nazionale di Fisica Nucleare (INFN), performed with very fast uncooled infrared detectors with a time resolution of a few hundreds of picoseconds. We resolved the emission time structure of the electron bunches of the DA{phi}NE collider when it works in a normal condition for high energy physics experiments with both photovoltaic and photoconductive detectors. Such a technology should pave the way to new diagnostic methods in storage rings, monitoring also source instabilities and bunch dynamics.

  1. CONTROL OF DYNAMIC APERTURE FOR SYNCHROTRON LIGHT SOURCES.

    SciTech Connect

    BENGTSSON, J.

    2005-05-15

    A summary of how modern analytical and numerical techniques enable one to construct a realistic model of state-of-the-art synchrotron light sources is provided. The effects of engineering tolerances and radiation are included in a self-consistent manner. An approach for utilizing these tools to develop an effective strategy for the design and control of the dynamic aperture for such dynamical systems is also outlined.

  2. NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 1998.

    SciTech Connect

    ROTHMAN,E.

    1999-05-01

    thereafter for half of the running time in FY 1998. In combination with the development of narrow gap undulators this mode opens the possibility of new undulators which could produce hard X-rays in the fundamental, perhaps up to 10 keV. On 27 September 1998, a low horizontal emittance lattice became operational at 2.584 GeV. This results in approximately a 50% decrease in the horizontal beam-size on dipole bending magnet beamlines, and somewhat less of a decrease on the insertion device lines. The beam lifetime is not degraded by the low emittance lattice. This represents an important achievement, enhancing for all users the x-ray ring brightness. The reduced horizontal emittance electron beam will produce brighter x-ray beams for all the beamlines, both bending magnets and insertion devices, adding to other recent increases in the X-Ray ring brightness. During FY 1999 users will gain experience of the new running mode and plans are in place to do the same at 2.8GeV during further studies sessions. Independent evidence of the reduced emittance is shown in Figure 2. This is a pinhole camera scan showing the X-ray beam profile, obtained on the diagnostic beamline X28. Finally, work has begun to update and refine the proposal of the Phase III upgrade endorsed by the Birgeneau panel and BESAC last year. With the whole NSLS facility in teenage years and with many demonstrated enhancements available, the time has come to herald in the next stage of life at the Light Source.

  3. Synchrotron light sources: A powerful tool for science and technology

    SciTech Connect

    Schlachter, F.; Robinson, A.

    1996-01-01

    A new generation of synchrotron light sources is producing extremely bright beams of vacuum-ultraviolet and x-ray radiation, powerful new tools for research in a wide variety of basic and applied sciences. Spectromicroscopy using high spectral and spatial resolution is a new way of seeing, offering many opportunities in the study of matter. Development of a new light source provides the country or region of the world in which the light source is located many new opportunities: a focal point for research in many scientific and technological areas, a means of upgrading the technology infrastructure of the country, a means of training students, and a potential service to industry. A light source for Southeast Asia would thus be a major resource for many years. Scientists and engineers from light sources around the world look forward to providing assistance to make this a reality in Southeast Asia.

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

    SciTech Connect

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

    2004-10-01

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

  5. Time-resolved GRB spectra in the complex radiation of synchrotron and Compton processes

    NASA Astrophysics Data System (ADS)

    Jiang, Y. G.; Hu, S. M.; Chen, X.; Li, K.; Guo, D. F.; Li, Y. T.; Li, H. Z.; Zhao, Y. Y.; Lin, H. N.; Chang, Z.

    2016-03-01

    Under the steady-state condition, the spectrum of electrons is investigated by solving the continuity equation under the complex radiation of both the synchrotron and Compton processes. The resulted gamma-ray burst (GRB) spectrum is a broken power law in both the fast and slow cooling phases. On the basis of this electron spectrum, the spectral indices of the Band function in four different phases are presented. In the complex radiation frame, the detail investigation on physical parameters reveals that three models can answer the α ˜ -1 problem, which are the synchrotron plus synchrotron self-Compton in the internal and the external shock models, and the synchrotron plus the external Compton processes in the external shock model. A possible marginal to fast cooling phase transition in GRB 080916C is discussed. The time-resolved spectra in different main pulses of GRB 100724B, GRB 100826A and GRB 130606B are investigated. We found that the flux is proportional to the peak energy in almost all main pulses. A significant (5σ) correlation for Fp ˜ Ep is evident the first main pulse of GRB 100826A, and three marginally significant (3σ) correlations Fp ˜ Ep are found in main pulses of GRB 100826A and GRB 130606B. The correlation between spectral index and Ep at 3 ˜ 4σ level are observed in the first main pulse of GRB 100826A. Such correlations are possible explained in the complex radiation scenario.

  6. Producing terahertz coherent synchrotron radiation at the Hefei Light Source

    NASA Astrophysics Data System (ADS)

    Xu, De-Rong; Xu, Hong-Liang; Shao, Yan

    2015-07-01

    This paper theoretically proves that an electron storage ring can generate coherent radiation in the THz region using a quick kicker magnet and an AC sextupole magnet. When the vertical chromaticity is modulated by the AC sextupole magnet, the vertical beam collective motion excited by the kicker produces a wavy spatial structure after a number of longitudinal oscillation periods. The radiation spectral distribution was calculated from the wavy bunch parameters at the Hefei Light Source (HLS). When the electron energy is reduced to 400 MeV, extremely strong coherent synchrotron radiation (CSR) at 0.115 THz should be produced. Supported by National Natural Science Foundation of China (11375176)

  7. Time-resolved experiments in the frequency domain using synchrotron radiation (invited)

    SciTech Connect

    De Stasio, G. ); Giusti, A.M.; Parasassi, T.; Ravagnan, G. ); Sapora, O. )

    1992-01-01

    PLASTIQUE is the only synchrotron radiation beam line in the world that performs time-resolved fluorescence experiments in frequency domain. These experiments are extremely valuable sources of information on the structure and the dynamics of molecules. This technique measures fluorescence lifetimes with picosecond resolution in the near UV spectral range. Such accurate measurements are rendered possible by taking phase and modulation data, and by the advantages of the cross-correlation technique. A successful experiment demonstrated the radiation damage induced by low doses of radiation on rabbit blood cell membranes.

  8. Condenser for illuminating a ringfield camera with synchrotron emission light

    DOEpatents

    Sweatt, William C.

    1996-01-01

    The present invention relates generally to the field of condensers for collecting light from a synchrotron radiation source and directing the light into a ringfield of a lithography camera. The present invention discloses a condenser comprising collecting, processing, and imaging optics. The collecting optics are comprised of concave and convex spherical mirrors that collect the light beams. The processing optics, which receive the light beams, are comprised of flat mirrors that converge and direct the light beams into a real entrance pupil of the camera in a symmetrical pattern. In the real entrance pupil are located flat mirrors, common to the beams emitted from the preceding mirrors, for generating substantially parallel light beams and for directing the beams toward the ringfield of a camera. Finally, the imaging optics are comprised of a spherical mirror, also common to the beams emitted from the preceding mirrors, images the real entrance pupil through the resistive mask and into the virtual entrance pupil of the camera. Thus, the condenser is comprised of a plurality of beams with four mirrors corresponding to a single beam plus two common mirrors.

  9. Condenser for illuminating a ringfield camera with synchrotron emission light

    DOEpatents

    Sweatt, W.C.

    1996-04-30

    The present invention relates generally to the field of condensers for collecting light from a synchrotron radiation source and directing the light into a ringfield of a lithography camera. The present invention discloses a condenser comprising collecting, processing, and imaging optics. The collecting optics are comprised of concave and convex spherical mirrors that collect the light beams. The processing optics, which receive the light beams, are comprised of flat mirrors that converge and direct the light beams into a real entrance pupil of the camera in a symmetrical pattern. In the real entrance pupil are located flat mirrors, common to the beams emitted from the preceding mirrors, for generating substantially parallel light beams and for directing the beams toward the ringfield of a camera. Finally, the imaging optics are comprised of a spherical mirror, also common to the beams emitted from the preceding mirrors, images the real entrance pupil through the resistive mask and into the virtual entrance pupil of the camera. Thus, the condenser is comprised of a plurality of beams with four mirrors corresponding to a single beam plus two common mirrors. 9 figs.

  10. Ozone production at the National Synchrotron Light Source

    SciTech Connect

    Weilandics, C.; Rohrig, N.; Gmur, N.F.

    1987-01-01

    Ozone production by synchrotron radiation as a function of power density in air was investigated using a white beam at the BNL National Synchrotron Light Source (NSLS) x-ray ring. Power densities were calculated from the energy spectrum at 2.52 GeV. Ozone concentrations in small beam pipes were measured for power densities between I = 10/sup 12/ and 10/sup 15/ eV . cm/sup -3/ . sec/sup -1/. The measured ozone half-life was 37 +- 2 min. The measured G-value was 2.69 +- 0.14 mol/100 eV and the ozone destruction factor k was less than 7 x 10/sup -19/ cm/sup 3/ . eV/sup -1/. The random uncertainties stated are approximately one standard error. The large departure of the values for G and k from previous values suggest that some undiscovered systematic error may exist in the experiment. Ozone concentration in excess of the 0.1 ppM ACGIH TLV can be generated in the experimental hutches but can readily be controlled. Industrial hygiene aspects of operation and possible control measures will be discussed. 19 refs., 7 figs., 3 tabs.

  11. A compact high brightness laser synchrotron light source for medical applications

    NASA Astrophysics Data System (ADS)

    Nakajima, Kazuhisa

    1999-07-01

    The present high-brightness hard X-ray sources have been developed as third generation synchrotron light sources based on large high energy electron storage rings and magnetic undulators. Recently availability of compact terawatt lasers arouses a great interest in the use of lasers as undulators. The laser undulator concept makes it possible to construct an attractive compact synchrotron radiation source which has been proposed as a laser synchrotron light source. This paper proposes a compact laser synchrotron light source for mediacal applications, such as an intravenous coronary angiography and microbeam therapy.

  12. DEVELOPMENTS IN SYNCHROTRON X-RAY COMPUTED MICROTOMOGRAPHY AT THE NATIONAL SYNCHROTRON LIGHT SOURCE.

    SciTech Connect

    DOWD,B.A.

    1999-07-23

    Last year, the X27A beamline at the National Synchrotron Light Source (NSLS) became dedicated solely to X-Ray Computed Microtomography (XCMT). This is a third-generation instrument capable of producing tomographic volumes of 1-2 micron resolution over a 2-3mm field of view. Recent enhancements will be discussed. These have focused on two issues: the desire for real-time data acquisition and processing and the need for highly monochromatic beam (.1 % energy bandpass). The latter will permit k-edge subtraction studies and will provide improved image contrast from below the Cr (6 keV) up to the Cs (36 keV) k-edge. A range of applications that benefit from these improvements will be discussed as well. These two goals are somewhat counterproductive, however; higher monochromaticity yields a lower flux forcing longer data acquisition times. To balance the two, a more efficient scintillator for X-ray conversion is being developed. Some testing of a prototype scintillator has been performed; preliminary results will be presented here. In the meantime, data reconstruction times have been reduced, and the entire tomographic acquisition, reconstruction and volume rendering process streamlined to make efficient use of synchrotron beam time. A Fast Filtered Back Transform (FFBT) reconstruction program recently developed helped to reduce the time to reconstruct a volume of 150 x 150 x 250 pixels{sup 3} (over 5 million voxels) from the raw camera data to 1.5 minutes on a dual R10,000 CPU. With these improvements, one can now obtain a ''quick look'' of a small tomographic volume ({approximately}10{sup 6}voxels) in just over 15 minutes from the start of data acquisition.

  13. Commissioning and operation of the first brazilian synchrotron light source.

    PubMed

    Rodrigues, A R; Craievich, A F; Gonçalves Da Silva, C E

    1998-05-01

    The synchrotron light source designed and constructed at the LNLS is composed of a 1.37 GeV electron storage ring and a 120 MeV linac for low-energy injection. The storage ring has been commissioned and has already reached the designed electron-beam energy, current and emittance. The electron lifetime is now 6 h at 60 mA, and is steadily increasing. Seven beamlines (TGM, SGM, SXS, XAFS, XRD, SAXS, PCr) have been constructed in parallel with the electron accelerators and are at present in operation. Beam time was allocated to 129 approved research projects for the second semester of 1997. A number of them are currently under way. PMID:15263777

  14. National synchrotron light source. Activity report, October 1, 1994--September 30, 1995

    SciTech Connect

    Rothman, E.Z.; Hastings, J.

    1996-05-01

    This report discusses research conducted at the National Synchrotron Light Source in the following areas: atomic and molecular science; energy dispersive diffraction; lithography, microscopy, and tomography; nuclear physics; scattering and crystallography studies of biological materials; time resolved spectroscopy; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; the 1995 NSLS annual users` meeting; 17th international free electron laser conference; micro bunches workshop; VUV machine; VUV storage ring parameters; beamline technical improvements; x-ray beamlines; x-ray storage ring parameters; the NSLS source development laboratory; the accelerator test facility (ATF); NSLS facility improvements; NSLS advisory committees; NSLS staff; VUV beamline guide; and x-ray beamline guide.

  15. Time-resolved spectroscopy of nucleic acid systems using synchrotron radiation from 230 nm to 354 nm

    NASA Astrophysics Data System (ADS)

    Daniels, Malcolm; Ballini, Jean-Pierre; Vigny, Paul

    1992-07-01

    The excited states of nucleic acids are complex, both at the individual chromophore level and because of the effect of stacking interactions on the electronic states. Considerable progress has been made recently by studying the lifetimes of the stacked states and by utilizing the technique of time-resolved spectroscopy. Experimental results obtained using the ACO synchrotron at LURE, Orsay, will be presented. Resolution of the decay data gives a model-based estimate of the number of emitting species and their lifetimes, and this information is then used to deconvolate experimental time-windowed spectra (time-delayed spectra) to give true time-resolved spectra. It is a unique feature of the synchrotron, compared with the laser, that the combination of delayed detection (photon counting) with the continuous wavelength distribution of the synchrotron allows the acquisition of excitation spectra by uninterrupted repetitive scanning over a wide range of UV exciting wavelengths, in the present work from 230 nm to 354 nm. Such time-delayed excitation spectra can also be deconvoluted into components corresponding to the various time-resolved emission spectra. In this way we are able to demonstrate for the first time that ground state stacking interactions are directly responsible for excimer-like emissions. Time-resolved emission spectra and time-resolved excitation spectra will be presented for the dinucleoside phosphate d(CG) and the synthetic alternating polynucleotide poly d(GC), a `B-type' DNA structure.

  16. National Synchrotron Light Source guidelines for the conduct of operations

    SciTech Connect

    Buckley, M.

    1998-01-01

    To improve the quality and uniformity of operations at the Department of Energy`s facilities, the DOE issued Order 5480.19 ``Conduct of Operations Requirements at DOE facilities.`` This order recognizes that the success of a facilities mission critically depends upon a high level of performance by its personnel and equipment. This performance can be severely impaired if the facility`s Conduct of Operations pays inadequate attention to issues of organization, safety, health, and the environment. These guidelines are Brookhaven National Laboratory`s and the National Synchrotron Light Source`s acknowledgement of the principles of Conduct of Operations and the response to DOE Order 5480.19. These guidelines cover the following areas: (1) operations organization and administration; (2) shift routines and operating practices; (3) control area activities; (4) communications; (5) control of on-shift training; (6) investigation of abnormal events; (7) notifications; (8) control of equipment and system studies; (9) lockouts and tagouts; (10) independent verification; (11) log-keeping; (12) operations turnover; (13) operations aspects of facility process control (14) required reading; (15) timely orders to operators; (16) operations procedures; (17) operator aid posting; and (18) equipment sizing and labeling.

  17. Parametric Modeling of Electron Beam Loss in Synchrotron Light Sources

    SciTech Connect

    Sayyar-Rodsari, B.; Schweiger, C.; Hartman, E.; Corbett, J.; Lee, M.; Lui, P.; Paterson, E.; /SLAC

    2007-11-28

    Synchrotron light is used for a wide variety of scientific disciplines ranging from physical chemistry to molecular biology and industrial applications. As the electron beam circulates, random single-particle collisional processes lead to decay of the beam current in time. We report a simulation study in which a combined neural network (NN) and first-principles (FP) model is used to capture the decay in beam current due to Touschek, Bremsstrahlung, and Coulomb effects. The FP block in the combined model is a parametric description of the beam current decay where model parameters vary as a function of beam operating conditions (e.g. vertical scraper position, RF voltage, number of the bunches, and total beam current). The NN block provides the parameters of the FP model and is trained (through constrained nonlinear optimization) to capture the variation in model parameters as operating condition of the beam changes. Simulation results will be presented to demonstrate that the proposed combined framework accurately models beam decay as well as variation to model parameters without direct access to parameter values in the model.

  18. PHOTOINJECTED ENERGY RECOVERY LINAC UPGRADE FOR THE NATIONAL SYNCHROTRON LIGHT SOURCE.

    SciTech Connect

    BEN-ZVI,I.; BABZIEN,M.; BLUM,E.; CASEY,W.; CHANG,X.; GRAVES,W.; HASTINGS,J.; HULBERT,S.; JOHNSON,E.; KAO,C.C.; KRAMER,S.; KRINSKY,S.; MORTAZAVI,P.; MURPHY,J.; OZAKI,S.; PJEROV,S.; PODOBEDOV,B.; RAKOWSKY,G.; ROSE,J.; SHAFTAN,T.; SHEEHY,B.; SIDDONS,D.; SMEDLEY,J.; SRINIVASAN-RAO,T.; TOWNE,N.; WANG,J.M.; WANG,X.; WU,J.; YAKIMENKO,V.; YU,L.H.

    2001-06-18

    We describe a major paradigm shift in the approach to the production of synchrotron radiation This change will considerably improve the scientific capabilities of synchrotron light sources. We introduce plans for an upgrade of the National Synchrotron Light Source (NSLS). This upgrade will be based on the Photoinjected Energy Recovering Linac (PERL). This machine emerges from the union of two technologies, the laser-photocathode RF gun (photoinjector) and superconducting linear accelerators with beam energy recovery (Energy Recovering Linac). The upgrade will bring the NSLS users many new insertion device beam lines, brightness greater than 3rd generation lightsource's and ultra-short pulse capabilities, not possible with storage ring light sources.

  19. Study of Laser Wakefield Accelerators as injectors for Synchrotron light sources

    NASA Astrophysics Data System (ADS)

    Hillenbrand, Steffen; Assmann, Ralph; Müller, Anke-Susanne; Jansen, Oliver; Judin, Vitali; Pukhov, Alexander

    2014-03-01

    Laser WakeField Accelerators (LWFA) feature short bunch lengths and high peak currents, combined with a small facility footprint. This makes them very interesting as injectors for Synchrotron light sources. Using the ANKA Synchrotron as an example, we investigate the possibility to inject a LWFA bunch into an electron storage ring. Particular emphasis is put on the longitudinal evolution of the bunch.

  20. Design of Grazing Incident Monochromator for Saga Synchrotron Light

    SciTech Connect

    Kondo, Yuzi; Azuma, Junpei; Takahashi, Kazutoshi; Kamada, Masao

    2004-05-12

    The Varied Line Spacing Plane Grating Monochromator (VLSPGM) was adopted for industry application beamline at Saga-ring. The VLSPGM is consisted of three focusing mirrors and one grating to suppress the higher order and stray light in the wide energy range by changing the deflection angle. The parameters of varied line spacing grating were determined so as to satisfy the condition that the terms expressing defocus, coma and spherical aberrations in the optical path function are equal to zero. The overall performance of the VLSPGM was estimated using ray-tracing calculations. The calculated resolving power with the slit widths of 10 and 20 {mu}m was more than 5,000 and 2,000 with the photon flux of more than 1x1010 and 6x1010 photons/sec/300mA, respectively.

  1. National synchrotron light source. [Annual report], October 1, 1992--September 30, 1993

    SciTech Connect

    Rothman, E.Z.; Hulbert, S.L.; Lazarz, N.M.

    1994-04-01

    This report contains brief discussions on the research being conducted at the National Synchrotron Light source. Some of the topics covered are: X-ray spectroscopy; nuclear physics; atomic and molecular science; meetings and workshops; operations; and facility improvements.

  2. A fast mechanical shutter for submicrosecond time-resolved synchrotron experiments

    SciTech Connect

    Gembicky, Milan; Oss, Dan; Fuchs, Ryan; Coppens, Philip

    2010-07-19

    A new high-speed high-repetition-rate X-ray beam shutter for time-resolved photocrystallography at synchrotron sources has been developed and tested. The new design is based on a commercially existing DC servomotor and a frequency-lock control capable linear amplifier. Accurate speed control combined with an air bearing results in extremely low jitter in the motor rotation. Measured jitter at rotation speeds of 12,000 to 30,000 r min{sup -1} is less than 2 ns at a 6{sigma} confidence level. The chopper disc is interchangeable, allowing maximum flexibility. The chopper disc currently installed has 45 radial slots which allows synchronization from the 12th to the 20th subfrequencies of the orbit frequency of the Advanced Photon Source storage ring, corresponding to X-ray pulse frequencies of 13.6 to 22.6 kHz. At 30000 r min{sup -1} the opening time window with a 350 {micro}m slot size is 2.11 {micro}s, and correspondingly less with smaller openings, which may be compared with the 3.68 {micro}s orbit time of the Advanced Photon Source. The shutter provides high accuracy and efficient use of X-rays at a modest cost.

  3. A fast mechanical shutter for submicrosecond time-resolved synchrotron experiments.

    PubMed

    Gembicky, Milan; Oss, Dan; Fuchs, Ryan; Coppens, Philip

    2005-09-01

    A new high-speed high-repetition-rate X-ray beam shutter for time-resolved photocrystallography at synchrotron sources has been developed and tested. The new design is based on a commercially existing DC servomotor and a frequency-lock control capable linear amplifier. Accurate speed control combined with an air bearing results in extremely low jitter in the motor rotation. Measured jitter at rotation speeds of 12000 to 30000 r min-1 is less than 2 ns at a 6sigma confidence level. The chopper disc is interchangeable, allowing maximum flexibility. The chopper disc currently installed has 45 radial slots which allows synchronization from the 12th to the 20th subfrequencies of the orbit frequency of the Advanced Photon Source storage ring, corresponding to X-ray pulse frequencies of 13.6 to 22.6 kHz. At 30000 r min-1 the opening time window with a 350 microm slot size is 2.11 micros, and correspondingly less with smaller openings, which may be compared with the 3.68 micros orbit time of the Advanced Photon Source. The shutter provides high accuracy and efficient use of X-rays at a modest cost. PMID:16120992

  4. XNAP: a hybrid pixel detector with nanosecond resolution for time resolved synchrotron radiation studies

    NASA Astrophysics Data System (ADS)

    Fajardo, P.; Baron, A. Q. R.; Dautet, H.; Davies, M.; Fischer, P.; Göttlicher, P.; Graafsma, H.; Hervé, C.; Rüffer, R.; Thil, C.

    2013-03-01

    The XNAP collaboration is constructing a hybrid pixel X-ray detector based on a monolithic silicon avalanche photodiode (APD) sensor array aiming at applications in synchrotron radiation facilities. The 2D detector is capable of identifying which individual electron bunch produces each detected X-ray photon, even when the storage ring operates in multibunch filling modes. This instrument is intended to be used in X-ray Photon Correlation Spectroscopy and Nuclear Resonance experiments and serve as a demonstrator for various kind of time resolved diffraction and scattering applications as well as a very high count rate device. The detector is a 1 kilopixel device with 280 μm pitch that implements both counting mode up to MHz frame rates and event-by-event readout with sub-nanosecond time resolution. The paper describes the detector design and some results obtained with small 4×4 pixel prototypes that have been built and measured to make and validate the most critical choices for the final detector.

  5. Shedding Synchrotron Light on a Puzzle of Glasses

    ScienceCinema

    Chumakov, Aleksandr [European Synchrotron Radiation Facility, Grenoble, France

    2010-01-08

    Vibrational dynamics of glasses remains a point of controversial discussions. In particular, the density of vibrational states (DOS) reveals an excess of states above the Debye model called "boson peak." Despite the fact that this universal feature for all glasses has been known for more than 35 years, the nature of the boson peak is still not understood. The application of nuclear inelastic scattering via synchrotron radiation perhaps provides a clearer, more consistent picture of the subject. The distinguishing features of nuclear inelastic scattering relative to, e.g., neutron inelastic scattering, are ideal momentum integration and exact scaling of the DOS in absolute units. This allows for reliable comparison to data from other techniques such as Brillouin light scattering. Another strong point is ideal isotope selectivity: the DOS is measured for a single isotope with a specific low-energy nuclear transition. This allows for special "design" of an experiment to study, for instance, the dynamics of only center-of-mass motions. Recently, we have investigated the transformation of the DOS as a function of several key parameters such as temperature, cooling rate, and density. In all cases the transformation of the DOS is sufficiently well described by a transformation of the continuous medium, in particular, by changes of the macroscopic density and the sound velocity. These results suggest a collective sound-like nature of vibrational dynamics in glasses and cast doubts on microscopic models of glass dynamics. Further insight can be obtained in combined studies of glass with nuclear inelastic and inelastic neutron scattering. Applying two techniques, we have measured the energy dependence of the characteristic correlation length of atomic motions. The data do not reveal localization of atomic vibrations at the energy of the boson peak. Once again, the results suggest that special features of glass dynamics are related to extended motions and not to local models.

  6. Synchrotron light source data book: Version 4, Revision 05/96

    SciTech Connect

    Murphy, J.B.

    1996-05-01

    This book is as its name implies a collection of data on existing and planned synchrotron light sources. The intention was to provide a compendium of tools for the design of electron storage rings as synchrotron radiation sources. The slant is toward the accelerator physicist as other booklets such as the X-Ray Data Booklet address the use of synchrotron radiation. It is hoped that the booklet serves as a pocket sized reference to facilitate back of the envelope type calculations. It contains some useful formulae in practical units and a brief description of many of the existing and planned light source lattices.

  7. Future Synchrotron Light Sources Based on Ultimate Storage Rings

    SciTech Connect

    Cai, Yunhai; /SLAC

    2012-04-09

    The main purpose of this talk is to describe how far one might push the state of the art in storage ring design. The talk will start with an overview of the latest developments and advances in the design of synchrotron light sources based on the concept of an 'ultimate' storage ring. The review will establish how bright a ring based light source might be, where the frontier of technological challenges are, and what the limits of accelerator physics are. Emphasis will be given to possible improvements in accelerator design and developments in technology toward the goal of achieving an ultimate storage ring. An ultimate storage ring (USR), defined as an electron ring-based light source having an emittance in both transverse planes at the diffraction limit for the range of X-ray wavelengths of interest for a scientific community, would provide very high brightness photons having high transverse coherence that would extend the capabilities of X-ray imaging and probe techniques beyond today's performance. It would be a cost-effective, high-coherence 4th generation light source, competitive with one based on energy recovery linac (ERL) technology, serving a large number of users studying material, chemical, and biological sciences. Furthermore, because of the experience accumulated over many decades of ring operation, it would have the great advantage of stability and reliability. In this paper we consider the design of an USR having 10-pm-rad emittance. It is a tremendous challenge to design a storage ring having such an extremely low emittance, a factor of 100 smaller than those in existing light sources, especially such that it has adequate dynamic aperture and beam lifetime. In many ultra-low emittance designs, the injection acceptances are not large enough for accumulation of the electron beam, necessitating on-axis injection where stored electron bunches are completely replaced with newly injected ones. Recently, starting with the MAX-IV 7-bend achromatic cell, we

  8. Synchrotron light sources: The search for quantum chaos

    SciTech Connect

    Schlachter, Fred

    2001-02-01

    A storage ring is a specialized synchrotron in which a stored beam of relativistic electrons produces radiation in the vuv and x-ray regions of the spectrum. High-brightness radiation is used at the ALS to study doubly excited autoionizing states of the helium atom in the search for quantum chaos.

  9. Time Resolved X-ray Magnetic Circular Dichroism at the Linac Coherent Light Source

    NASA Astrophysics Data System (ADS)

    Schlotter, W.; Higley, D.; Jal, E.; Dakovski, G.; Yuan, E.; MacArthur, J.; Lutman, A.; Hirsch, K.; Granitzka, P.; Chen, Z.; Coslovich, G.; Hoffman, M.; Mitra, A.; Reid, A.; Hart, P.; Nuhn, H.-D.; Duerr, H.; Arenholz, E.; Shafer, P.; Dennes, P.; Joseph, J.; Guyader, L.; Tsukamoto, A.

    We demonstrate ultrafast time resolved X-ray Magnetic Circular Dichroism on optically switchable GdFeCo thin film samples. This method extends the element specificity of time resolved x-ray absorption spectroscopy to characterize the evolution of electron spin and orbital angular momenta. These measurements were enabled by a recent upgrade at the Linac Coherent Light Source (LCLS) to generate circularly polarized x-rays. Additionally these measurements were enhanced by new detection systems that benefit all x-ray absorption spectroscopy experiments performed in transmission. Consequently static XMCD data are in excellent agreement with similar measurements at synchrotron light sources. The LCLS is an x-ray free electron laser user facility accessible via a peer-reviewed proposal process. Acknowledgement: The Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515.

  10. Time-Resolved Synchrotron X-ray Diffraction on Pulse Laser Heated Iron in Diamond Anvil Cell

    SciTech Connect

    Yoo, C S; Wei, H; Dias, R; Shen, G; Smith, J; Chen, J Y; Evans, W

    2011-09-21

    The authors present time-resolved synchrotron x-ray diffraction to probe the {var_epsilon}-{delta} phase transition of iron during pulse-laser heating in a diamond anvil cell. The system utilizes a monochromatic synchrotron x-ray beam, a two-dimensional pixel array x-ray detector and a dual beam, double side laser-heating system. Multiple frames of the diffraction images are obtained in real-time every 22 ms over 500 ms of the entire pulse heating period. The results show the structural evolution of iron phases at 17 GPa, resulting in thermal expansion coefficient 1/V({Delta}V/{Delta}T){sub p} = 7.1 * 10{sup -6}/K for {var_epsilon}-Fe and 2.4 * 10{sup -5}/K for {gamma}-Fe, as well as the evidence for metastability of {gamma}-Fe at low temperatures below the {var_epsilon}-{gamma} phase boundary.

  11. A time resolved microfocus XEOL facility at the Diamond Light Source

    NASA Astrophysics Data System (ADS)

    Mosselmans, J. F. W.; Taylor, R. P.; Quinn, P. D.; Finch, A. A.; Cibin, G.; Gianolio, D.; Sapelkin, A. V.

    2013-03-01

    We have constructed a Time-Resolved X-ray Excited Optical Luminescence (TR-XEOL) detection system at the Microfocus Spectroscopy beamline I18 at the Diamond Light Source. Using the synchrotron in "hybrid bunch mode", the data collection is triggered by the RF clock, and we are able to record XEOL photons with a time resolution of 6.1 ps during the 230 ns gap between the hybrid bunch and the main train of electron bunches. We can detect photons over the range 180-850 nm using a bespoke optical fibre, with X-ray excitation energies between 2 and 20 keV. We have used the system to study a range of feldspars. The detector is portable and has also been used on beamline B18 to collect Optically Determined X-ray Absorption Spectroscopy (OD-XAS) in QEXAFS mode.

  12. Diffraction and Transmission Synchrotron Imaging at the German Light Source ANKA--Potential Industrial Applications

    SciTech Connect

    Rack, Alexander; Weitkamp, Timm; Helfen, Lukas; Simon, Rolf; Luebbert, Daniel; Baumbach, Tilo

    2009-03-10

    Diffraction and transmission synchrotron imaging methods have proven to be highly suitable for investigations in materials research and non-destructive evaluation. The high flux and spatial coherence of X-rays from modern synchrotron light sources allows one to work using high resolution and different contrast modalities. This article gives a short overview of different transmission and diffraction imaging methods with high potential for industrial applications, now available for commercial access via the German light source ANKA (Forschungszentrum Karlsruhe) and its new department ANKA Commercial Service (ANKA COS, http://www.anka-cos.de)

  13. Mechanical Design of the HER Synchrotron Light Monitor Primary Mirror

    SciTech Connect

    Daly, Edward F.; Fisher, Alan S.; Kurita, Nadine R.; Langton, J.; /SLAC

    2011-09-14

    This paper describes the mechanical design of the primary mirror that images the visible portion of the synchrotron radiation (SR) extracted from the High Energy Ring (HER) of the PEP-II B-Factory. During off-axis operation, the water-cooled GlidCop mirror is subjected to a heat flux in excess of 2000 W/cm2. When on-axis imaging occurs, the heat flux due to scattered SR, resistive wall losses and Higher-Order-Mode (HOM) heating is estimated at 1 W/cm2. The imaging surface is plated with Electroless Nickel to improve its optical characteristics. The design requirements for the primary mirror are listed and discussed. Calculated mechanical distortions and stresses experienced by the mirror during on-axis and off-axis operation will be presented.

  14. Deflection gating for time-resolved x-ray magnetic circular dichroism-photoemission electron microscopy using synchrotron radiation

    SciTech Connect

    Wiemann, C.; Kaiser, A. M.; Cramm, S.; Schneider, C. M.

    2012-06-15

    In this paper, we present a newly developed gating technique for a time-resolving photoemission microscope. The technique makes use of an electrostatic deflector within the microscope's electron optical system for fast switching between two electron-optical paths, one of which is used for imaging, while the other is blocked by an aperture stop. The system can be operated with a switching time of 20 ns and shows superior dark current rejection. We report on the application of this new gating technique to exploit the time structure in the injection bunch pattern of the synchrotron radiation source BESSY II at Helmholtz-Zentrum Berlin for time-resolved measurements in the picosecond regime.

  15. Deflection gating for time-resolved x-ray magnetic circular dichroism-photoemission electron microscopy using synchrotron radiation.

    PubMed

    Wiemann, C; Kaiser, A M; Cramm, S; Schneider, C M

    2012-06-01

    In this paper, we present a newly developed gating technique for a time-resolving photoemission microscope. The technique makes use of an electrostatic deflector within the microscope's electron optical system for fast switching between two electron-optical paths, one of which is used for imaging, while the other is blocked by an aperture stop. The system can be operated with a switching time of 20 ns and shows superior dark current rejection. We report on the application of this new gating technique to exploit the time structure in the injection bunch pattern of the synchrotron radiation source BESSY II at Helmholtz-Zentrum Berlin for time-resolved measurements in the picosecond regime. PMID:22755633

  16. National Synchrotron Light Source angiography personnel protection interlock

    SciTech Connect

    Gmuer, N.; Larson, R.; Thomlinson, W.

    1992-06-01

    This document has been written to describe the safety system operation at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). The angiography exposure process involves scanning a patient up and down through dual fixed-position x-ray beams; exposure is controlled by opening and closing a fast-acting Safety Shutter mechanism at precise times in relation to the up and down motion of the scan chair. The fast-acting Safety Shutter mechanism is the primary radiation-stopping element protecting the patient while the chair is at rest and while it is reversing directions during the scan. Its fail-safe and fast operation is essential for the safety of the patient. Operation of X17B2 as a human subject angiography station necessitates the implementation of a personnel protection interlock system that, in conjunction with the Safety Shutters: permits safe access to the patient exposure area while the synchrotron radiation beam is illuminating the upstream dual energy monochromator; allows a patient to be imaged by the monochromatized beam under the supervision of a Responsible Physician, with scan chair motion and precision shutter actuation regulated by an angiography control computer, while providing a suitable number of safeguards against accidental radiation exposure; has different modes of operation to accommodate equipment set-up, test, and calibration; and patient exposure; and ensures the quick extinction of the beam if a potentially unsafe condition is detected. The interlock system which performs these safety functions is called the Angiography Personnel Protection Interlock (APPI). The APPI Document is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system.

  17. 1994 Activity Report, National Synchrotron Light Source. Annual report, October 1, 1993-September 30, 1994

    SciTech Connect

    Rothman, E.Z.

    1995-05-01

    This report is a summary of activities carried out at the National Synchrotron Light Source during 1994. It consists of sections which summarize the work carried out in differing scientific disciplines, meetings and workshops, operations experience of the facility, projects undertaken for upgrades, administrative reports, and collections of abstracts and publications generated from work done at the facility.

  18. Application of electron linacs in medicine, food sterilization and synchrotron light sources

    NASA Astrophysics Data System (ADS)

    Tran, Duc-Tien

    1989-04-01

    A review of the state of the art and new trends in electron linac technology is given with emphasis on three particular applications: radiotherapy, food sterilization and synchrotron light sources. The requirements on linac performances that these applications call for, namely energy variation flexibility, high power, high energy and low cost, will open linacs to new applications to come.

  19. Vacuum ultraviolet luminescence of wide band-gap solids studied using time-resolved spectroscopy with synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Makhov, V. N.

    2014-04-01

    Some highlights of the time-resolved vacuum ultraviolet (VUV) luminescence spectroscopy of solids using synchrotron radiation (SR) are outlined, including studies of the unique phenomenon crossluminescence (CL) and the contribution of time-resolved VUV spectroscopy to the understanding of 5d-4f transitions of rare earth ions in solids. The main properties of CL studied at different SR sources are described and some unclear aspects of CL are pointed out. The results of recent studies of some CL-active nanosize materials are presented. We describe the time-resolved experiments which led to the discovery of 5d-4f luminescence in the deep VUV region (near 10 eV) of Gd3+ and Lu3+ ions incorporated into some wide band-gap fluoride hosts. The results of high-resolution (Δλ ˜ 0.5 Å) studies of 5d-4f emission and 4f-5d excitation spectra of Gd3+ and Lu3+, which allowed the detailed analysis of electron-lattice coupling in these systems, are presented. Possible new developments in the femtosecond time-resolved spectroscopy of solids with a free electron laser are discussed.

  20. Neutron field measurements at the Aladdin Synchrotron Light Source.

    PubMed

    Yang, Y; Li, Y; DeLuca, P M; Otte, R; Rowe, E M

    1986-01-01

    The neutron field near the inflector of the 800-MeV electron storage ring was studied. Photon-induced neutrons are produced by 100-MeV electrons bombarding the inflector during injection into the synchrotron ring. Neutrons were measured with moderating detectors made of 15 X 15 X 20 cm Lucite blocks and Au activation foils. Detector response was established with a Pu-Be neutron source and a 25.4-cm polyethylene sphere and Au foil detector. The neutron yield was 0.97 +/- 0.14 X 10(12) kJ-1. For 1.38 W of electron pulse power, the dose equivalent rate 1 m aside and 1 m above the inflector was 4.35 +/- 0.47 mu Sv s-1 and 3.13 +/- 0.23 mu Sv s-1, respectively. A measured dose equivalent transmission curve for polyethylene yielded an attenuation coefficient of 15.7 m-1. PMID:3943962

  1. SUNY beamline facilities at the National Synchrotron Light Source (Final Report)

    SciTech Connect

    Coppens, Philip

    2003-06-22

    The DOE sponsored SUNY synchrotron project has involved close cooperation among faculty at several SUNY campuses. A large number of students and postdoctoral associates have participated in its operation which was centered at the X3 beamline of the National Synchrotron Light Source at Brookhaven National Laboratory. Four stations with capabilities for Small Angle Scattering, Single Crystal and Powder and Surface diffraction and EXAFS were designed and operated with capability to perform experiments at very low as well as elevated temperatures and under high vacuum. A large amount of cutting-edge science was performed at the facility, which in addition provided excellent training for students and postdoctoral scientists in the field.

  2. ZAP and its application to the optimization of synchrotron light source parameters

    SciTech Connect

    Zisman, M.S.

    1987-03-01

    The design of electron storage rings for the production of synchrotron radiation has become increasingly sophisticated in recent years. To assist in the optimization of such storage rings, a new, user-friendly code to treat the relevant collective phenomena, called ZAP, has been written at LBL. The code is designed primarily to carry out parameter studies of electron storage rings, although options for protons or heavy ions are included where appropriate. In this paper, we first describe the contents of the code itself, and then illustrate, via selected examples, how the collective effects treated by ZAP manifest themselves in the new generation of synchrotron light sources.

  3. Spatial and temporal beam profiles for the LHC using synchrotron light

    NASA Astrophysics Data System (ADS)

    Jeff, A.; Bart Pedersen, S.; Boccardi, A.; Bravin, E.; Fisher, A. S.; Guerrero Ollacarizqueta, A.; Lefevre, T.; Rabiller, A.; Welsch, C. P.

    2010-04-01

    Synchrotron radiation is emitted whenever a beam of charged particles passes though a magnetic field. The power emitted is strongly dependent on the relativistic Lorentz factor of the particles, which itself is proportional to the beam energy and inversely proportional to the particle rest mass. Thus, synchrotron radiation is usually associated with electron accelerators, which are commonly used as light sources. However the largest proton machines reach sufficiently high energies to make synchrotron light useful for diagnostic purposes. The Large Hadron Collider at CERN will accelerate protons up to an energy of 7TeV. An optical arrangement has been made which focuses synchrotron light from two LHC magnets to image the cross-section of the beam. It is also planned to use this setup to produce a longitudinal profile of the beam by use of fast Single Photon Counting. This is complicated by the bunched nature of the beam which needs to be measured with a very large dynamic range. In this contribution we present early experimental data of the transverse LHC beam profile together with a scheme for measuring the longitudinal profile with a time resolution of 50 ps. It includes the use of a gating regime to increase the dynamic range of the photon counter and a three-stage correction algorithm to compensate for the detector's deadtime, afterpulsing and pile-up effects.

  4. Measurements of a prototype synchrotron radiation pumped absorber for future light sources

    SciTech Connect

    Chou, T.S.; Foerster, C.L.; Halama, H.; Lanni, C.

    1988-01-01

    In the new generation of advanced synchrotron light sources, the conventional concept of distributed pumping is no longer suitable for removing the gas load caused by photon stimulated desorption (PSD). A new concept using a combination of photon absorber and pumping station has been designed, constructed, and installed in the U1OB beam line at the VUV ring of the National Synchrotron Light Source. The system consists of an electrically insulated water cooled copper block, a titanium sublimation pump, calibrated BA gauges, a calibrated RGA, and a known conductance. A photon beam 10 milliradian wide and 3.26 milliradian high, having critical energy of 500 eV, is directed on the absorber. PSD yield is studied as a function of total beam dose and absorber surface preparation. The results from this experiment, pump characteristics, design of an absorber pump for future light sources, and the pressure improvement factors will be presented. 5 refs., 7 figs., 1 tab.

  5. Measurements of a prototype synchrotron radiation pumped absorber for future light sources

    NASA Astrophysics Data System (ADS)

    Chou, T. S.; Foerster, C. L.; Halama, H.; Lanni, C.

    1988-09-01

    In the new generation of advanced synchrotron light sources, the conventional concept of distributed pumping is no longer suitable for removing the gas load caused by photon stimulated desorption (PSD). A new concept using a combination of photon absorber and pumping station has been designed, constructed, and installed in the U10B beam line at the VUV ring of the National Synchrotron Light Source. The system consists of an electrically insulated water cooled copper block, a titanium sublimation pump, calibrated BA gauges, a calibrated RGA, and a known conductance. A photon beam 10 milliradian wide and 3.26 milliradian high, having critical energy of 500 eV, is directed on the absorber. PSD yield is studied as a function of total beam dose and absorber surface preparation. The results from this experiment, pump characteristics, design of an absorber pump for future light sources, and the pressure improvement factors will be presented.

  6. Shedding new light on historical metal samples using micro-focused synchrotron X-ray fluorescence and spectroscopy

    NASA Astrophysics Data System (ADS)

    Grolimund, D.; Senn, M.; Trottmann, M.; Janousch, M.; Bonhoure, I.; Scheidegger, A. M.; Marcus, M.

    2004-10-01

    insights concerning the nature and origin of used raw materials as well as regarding employed processing techniques during historic iron fabrication and weapon manufacturing.The study demonstrates the potential of oxidation state and mineral phase mapping based on energy selective micro-XRF maps and spectroscopic phase identification. Such a spatially resolved recording of the chemical speciation is based on X-ray absorption spectroscopy. This analytical technique is exclusive to synchrotron light sources. However, the steadily increasing number of available synchrotron-based X-ray microprobes allows nowadays for more routine utilization of such micro-XAS techniques.

  7. An Upgrade for the Brazilian Synchrotron Light Source: Are you Sirius?

    NASA Astrophysics Data System (ADS)

    Roque da Silva, Antonio José

    2015-03-01

    The application of synchrotron radiation in a great variety of fields in general, and condensed matter in particular, has increased steadily worldwide. This, to a large extent, is a result of the availability of the much brighter third-generation light sources, which opened up new experimental techniques. Recently, new developments in accelerator technology are paving the way for even brighter sources, which are being named fourth-generation light sources. Sirius, the future new Brazilian synchrotron, is one of the first two such machines being currently constructed in the world. Its first light is expected by 2018. It is being planned to be a state of the art machine, providing tools for cutting edge research that are non existent today in Brazil. It is a project designed and executed by the Laboratório Nacional de Luz Síncrotron - LNLS, which was also responsible for the construction of the current second generation Brazilian light source, the first synchrotron in the southern hemisphere, still the only one in Latin America. In this talk an overview of the status of Sirius will be provided.

  8. Time-resolved structural studies with serial crystallography: A new light on retinal proteins

    PubMed Central

    Panneels, Valérie; Wu, Wenting; Tsai, Ching-Ju; Nogly, Przemek; Rheinberger, Jan; Jaeger, Kathrin; Cicchetti, Gregor; Gati, Cornelius; Kick, Leonhard M.; Sala, Leonardo; Capitani, Guido; Milne, Chris; Padeste, Celestino; Pedrini, Bill; Li, Xiao-Dan; Standfuss, Jörg; Abela, Rafael; Schertler, Gebhard

    2015-01-01

    Structural information of the different conformational states of the two prototypical light-sensitive membrane proteins, bacteriorhodopsin and rhodopsin, has been obtained in the past by X-ray cryo-crystallography and cryo-electron microscopy. However, these methods do not allow for the structure determination of most intermediate conformations. Recently, the potential of X-Ray Free Electron Lasers (X-FELs) for tracking the dynamics of light-triggered processes by pump-probe serial femtosecond crystallography has been demonstrated using 3D-micron-sized crystals. In addition, X-FELs provide new opportunities for protein 2D-crystal diffraction, which would allow to observe the course of conformational changes of membrane proteins in a close-to-physiological lipid bilayer environment. Here, we describe the strategies towards structural dynamic studies of retinal proteins at room temperature, using injector or fixed-target based serial femtosecond crystallography at X-FELs. Thanks to recent progress especially in sample delivery methods, serial crystallography is now also feasible at synchrotron X-ray sources, thus expanding the possibilities for time-resolved structure determination. PMID:26798817

  9. Time-resolved structural studies with serial crystallography: A new light on retinal proteins.

    PubMed

    Panneels, Valérie; Wu, Wenting; Tsai, Ching-Ju; Nogly, Przemek; Rheinberger, Jan; Jaeger, Kathrin; Cicchetti, Gregor; Gati, Cornelius; Kick, Leonhard M; Sala, Leonardo; Capitani, Guido; Milne, Chris; Padeste, Celestino; Pedrini, Bill; Li, Xiao-Dan; Standfuss, Jörg; Abela, Rafael; Schertler, Gebhard

    2015-07-01

    Structural information of the different conformational states of the two prototypical light-sensitive membrane proteins, bacteriorhodopsin and rhodopsin, has been obtained in the past by X-ray cryo-crystallography and cryo-electron microscopy. However, these methods do not allow for the structure determination of most intermediate conformations. Recently, the potential of X-Ray Free Electron Lasers (X-FELs) for tracking the dynamics of light-triggered processes by pump-probe serial femtosecond crystallography has been demonstrated using 3D-micron-sized crystals. In addition, X-FELs provide new opportunities for protein 2D-crystal diffraction, which would allow to observe the course of conformational changes of membrane proteins in a close-to-physiological lipid bilayer environment. Here, we describe the strategies towards structural dynamic studies of retinal proteins at room temperature, using injector or fixed-target based serial femtosecond crystallography at X-FELs. Thanks to recent progress especially in sample delivery methods, serial crystallography is now also feasible at synchrotron X-ray sources, thus expanding the possibilities for time-resolved structure determination. PMID:26798817

  10. Microchemical Structure of Soybean Seeds Revealed in Situ by Ultraspatially Resolved Synchrotron Fourier Transformed Infrared Microspectroscopy

    SciTech Connect

    Pietrzak,L.; Miller, S.

    2005-01-01

    The distribution of water in soybean seeds during imbibition varies with the chemical composition of the tissue. To understand the dynamics of imbibition, the proteins, lipids, and carbohydrates of the cotyledons and hilum region in mature soybean seeds were mapped using synchrotron Fourier transformed infrared microspectroscopy, based on characteristic peaks for each component: amide I at 1650 cm{sup -1} and amide II at 1550 cm{sup -1} for protein, lipid ester stretch at 1545 cm{sup -1}, and the region from 1200 to 900 cm{sup -1} for carbohydrates. The amount and configuration of the proteins varied across the cotyledon, as well as the amount of lipid and carbohydrate. It was found that protein distribution across the cotyledon is similar to water distribution during imbibition. The chemistry of the hilum region was also studied, as this is the point of water entry, and differences in the chemical composition of the tissues studied were observed.

  11. Low-Level Radio Frequency System Development for the National Synchrotron Light Source II

    SciTech Connect

    Ma,H.; Rose, J.

    2009-05-04

    The National Synchrotron Light Source-II (NSLS-II) is a new ultra-bright 3GeV 3rd generation synchrotron radiation light source. The performance goals require operation with a beam current of 500mA and a bunch current of at least 0.5mA. The position and timing specifications of the ultra-bright photon beam imposes a set of stringent requirements on the performance of radio frequency (RF) control. In addition, commissioning and staged installation of damping wigglers and insertion devices requires the flexibility of handling varying beam conditions. To meet these requirements, a digital implementation of the LLRF is chosen, and digital serial links are planned for the system integration. The first prototype of the controller front-end hardware has been built, and is currently being tested.

  12. National Synchrotron Light Source users manual: Guide to the VUV and x-ray beam lines

    SciTech Connect

    Gmuer, N.F.; White-DePace, S.M.

    1987-08-01

    The success of the National Synchrotron Light Source in the years to come will be based, in large part, on the size of the users community and the diversity of the scientific disciplines represented by these users. In order to promote this philosophy, this National Synchrotron Light Source (NSLS) Users Manual: Guide to the VUV and X-Ray Beam Lines, has been published. This manual serves a number of purposes. In an effort to attract new research, it will present to the scientific community-at-large the current and projected architecture and capabilities of the various VUV and x-ray beam lines and storage rings. We anticipate that this publication will be updated periodically in order to keep pace with the constant changes at the NSLS.

  13. Fringe Pattern of the PEP-II Synchrotron-Light Interferometers

    SciTech Connect

    Fisher, Alan; /SLAC

    2005-09-19

    Synchrotron-light interferometry is used to measure the vertical beam sizes in the high-energy and low-energy rings (HER and LER) of the PEP-II B Factory at SLAC. Light from a point in a dipole magnet is diffracted by two slits and then imaged onto a CCD camera. A curve fitting algorithm matches the measured interference fringes to a calculated pattern that includes the effect on the modulation depth of the fringes due to both the small but nonzero source size and the narrow bandpass of the optical filter. These formulas are derived here. Next, an additional focusing term from the primary mirror in the vacuum chamber is considered. The mirror needs extensive cooling due to the intense fan of synchrotron x-rays and is likely to have a slight stress-induced curvature, which must be considered to determine the true source size.

  14. Shielding synchrotron light sources: Advantages of circular shield walls tunnels

    NASA Astrophysics Data System (ADS)

    Kramer, S. L.; Ghosh, V. J.; Breitfeller, M.

    2016-08-01

    Third generation high brightness light sources are designed to have low emittance and high current beams, which contribute to higher beam loss rates that will be compensated by Top-Off injection. Shielding for these higher loss rates will be critical to protect the projected higher occupancy factors for the users. Top-Off injection requires a full energy injector, which will demand greater consideration of the potential abnormal beam miss-steering and localized losses that could occur. The high energy electron injection beam produce significantly higher neutron component dose to the experimental floor than lower energy injection and ramped operations. High energy neutrons produced in the forward direction from thin target beam losses are a major component of the dose rate outside the shield walls of the tunnel. The convention has been to provide thicker 90° ratchet walls to reduce this dose to the beam line users. We present an alternate circular shield wall design, which naturally and cost effectively increases the path length for this forward radiation in the shield wall and thereby substantially decreasing the dose rate for these beam losses. This shield wall design will greatly reduce the dose rate to the users working near the front end optical components but will challenge the beam line designers to effectively utilize the longer length of beam line penetration in the shield wall. Additional advantages of the circular shield wall tunnel are that it's simpler to construct, allows greater access to the insertion devices and the upstream in tunnel beam line components, as well as reducing the volume of concrete and therefore the cost of the shield wall.

  15. Angularly-resolved elastic light scattering of micro-particles

    NASA Astrophysics Data System (ADS)

    Aptowicz, Kevin B.

    From microbiology to astrophysics, the scientific community has long embraced elastic light scattering from small particles as a diagnostic tool. Elastic light scattering has an extremely large scattering cross-section, allowing for single particle interrogation. This is critical in applications where trace amounts of suspect particles are to be detected in a diverse background of natural aerosols. By angularly-resolving the elastically scattered light, features can be detected in these patterns that are sensitive to a particle's morphology (shape, size, internal structure, and composition). An apparatus to collect LA TAOS (Large-Angle Two-dimensional Angular Optical Scattering) patterns from single particles in-situ and in real-time was designed and constructed. The setup utilizes a cross-beam trigger system to minimize the effects of the aberration coma stemming from the main collection optic, an ellipsoidal mirror. LA TAOS patterns of ambient aerosols were collected and analyzed. Approximately 15% of the ambient aerosol had a sphere-like shape. The refractive index of these spheres was estimated by curve-fitting to Lorenz-Mie theory. In addition, the island features prevalent in the LA TAOS pattern were analyzed. Metrics generated from these were used to get partial discrimination between clusters of Bacillus subtilis spores (a simulant for anthrax) and aerosol particles found in the ambient atmosphere. A novel experimental setup for collecting simultaneously LA TAOS patterns at two wavelengths in the mid-infrared was also implemented. With this setup, the relative strength of single-particle absorption could be discerned at the two illuminating wavelengths.

  16. Kinetic Analyses of Cation Exchange Rates in Synthetic Birnessite Measured by Time- Resolved Synchrotron X-ray Diffraction

    NASA Astrophysics Data System (ADS)

    Lopano, C. L.; Heaney, P. J.; Post, J. E.; Bandstra, J.; Brantley, S. L.

    2006-05-01

    Birnessite is the most abundant and chemically important layer-structure Mn-oxide phase found in soils, desert varnishes, and ocean nodules. It also is industrially important for use in battery technology and octahedral sieves. Due to the poorly crystalline nature of natural birnessite, synthetic analogues typically have been employed in studies that explore the structural response of birnessite to variations in interlayer composition. For this work, we measured changes in unit-cell parameters over time to quantify the degree of cation exchange as a function of concentration. Aqueous K+, Cs+, and Ba2+ cations at varying concentrations at pH 7 were exchanged for interlayer Na+ in synthetic birnessite (Na0.58(Mn4+1.42,Mn3+0.58)O4·1.5H2O) using a simple flow- through cell, and the exchange products were monitored via time-resolved X-ray powder diffraction at the National Synchrotron Light Source. Powder X-ray diffraction patterns were collected every 2-3 minutes. Rietveld analyses of X-ray diffraction patterns for K- and Ba-exchanged birnessite revealed a decrease in unit- cell volume over time. In contrast, Cs+ substitution increased cell volume. For all three cations, the crystallographic data indicate that exchange occurred in two stages. A rapid and dramatic change in unit-cell volume was followed by a modest adjustment over longer timescales. Fourier electron difference syntheses revealed that the rapid, initial stage of exchange was marked by re-configuration of the interlayer species, whereas the second, protracted phase of substitution represented ordering into the newly established interlayer positions. For the first time, we have modeled the kinetics of interlayer substitution in Na-birnessite. For purposes of comparison, we have employed a simple one-stage reaction (i.e., Na-birnessite → K-birnessite) and a two stage reaction (i.e,. Na-birnessite → K-birnessitedisordered → K- birnessiteordered). For exchange with 0.01 M KCl solutions, the single

  17. Operating synchrotron light sources with a high gain free electron laser

    NASA Astrophysics Data System (ADS)

    Di Mitri, S.; Cornacchia, M.

    2015-11-01

    Since the 1980s synchrotron light sources have been considered as drivers of a high repetition rate (RR), high gain free electron laser (FEL) inserted in a by-pass line or in the ring itself. As of today, the high peak current required by the laser is not deemed to be compatible with the standard multi-bunch filling pattern of synchrotrons, and in particular with the operation of insertion device (ID) beamlines. We show that this problem can be overcome by virtue of magnetic bunch length compression in a ring section, and that, after lasing, the beam returns to equilibrium conditions without beam quality disruption. Bunch length compression brings a double advantage: the high peak current stimulates a high gain FEL emission, while the large energy spread makes the beam less sensitive to the FEL heating and to the microwave instability in the ring. The beam’s large energy spread at the undulator is matched to the FEL energy bandwidth through a transverse gradient undulator. Feasibility of lasing at 25 nm is shown for the Elettra synchrotron light source at 1 GeV, and scaling to shorter wavelengths as a function of momentum compaction, beam energy and transverse emittance in higher energy, larger rings is discussed. For the Elettra case study, a low (100 Hz) and a high (463 kHz) FEL RR are considered, corresponding to an average FEL output power at the level of ∼1 W (∼1013 photons per pulse) and ∼300 W (∼1011 photons per pulse), respectively. We also find that, as a by-product of compression, the ∼5 W Renieri’s limit on the average FEL power can be overcome. Our conclusion is that existing and planned synchrotron light sources may be made compatible with this new hybrid IDs-plus-FEL operational mode, with little impact on the standard beamlines functionality.

  18. Status and Highlights of CANDLE Synchrotron Light Source Project in Armenia

    NASA Astrophysics Data System (ADS)

    Tsakanov, V. M.

    2007-01-01

    CANDLE — Center for the Advancement of Natural Discoveries using Light Emission — is a 3 GeV energy synchrotron light facility project in the Republic of Armenia. The facility has the potential to provide more than 40 beamlines from bends, undulators and wigglers in wide spectral range from ultraviolet to hard X-Rays. The project is supposed to be an international facility for advanced studies in life and material sciences. The main features and the status of the project are presented. The preliminary list of first group beamlines is discussed.

  19. Status and Highlights of CANDLE Synchrotron Light Source Project in Armenia

    SciTech Connect

    Tsakanov, V. M.

    2007-01-19

    CANDLE - Center for the Advancement of Natural Discoveries using Light Emission - is a 3 GeV energy synchrotron light facility project in the Republic of Armenia. The facility has the potential to provide more than 40 beamlines from bends, undulators and wigglers in wide spectral range from ultraviolet to hard X-Rays. The project is supposed to be an international facility for advanced studies in life and material sciences. The main features and the status of the project are presented. The preliminary list of first group beamlines is discussed.

  20. Beam dynamics of a new low emittance third generation synchrotron light source facility

    NASA Astrophysics Data System (ADS)

    Ghasem, H.; Ahmadi, E.; Saeidi, F.; Sarhadi, K.

    2015-03-01

    The Iranian Light Source Facility (ILSF) is a new 3 GeV third generation synchrotron light source facility which is in the design stage. As the main radiation source, design of the ILSF storage ring emphasizes an ultralow electron beam emittance, great brightness, stability and reliability. The storage ring is based on a five-bend achromat lattice providing an ultralow horizontal beam emittance of 0.48 nm rad. In this paper, we present the design feature of the ILSF storage ring, give the linear and nonlinear dynamic properties of the lattice and discuss the related beam dynamic specifications.

  1. SYNCHROTRON RADIATION, FREE ELECTRON LASER, APPLICATION OF NUCLEAR TECHNOLOGY, ETC.: Study on the characteristics of linac based THz light source

    NASA Astrophysics Data System (ADS)

    Zhu, Xiong-Wei; Wang, Shu-Hong; Chen, Sen-Yu

    2009-10-01

    There are many methods based on linac for THz radiation production. As one of the options for the Beijing Advanced Light, an ERL test facility is proposed for THz radiation. In this test facility, there are 4 kinds of methods to produce THz radiation: coherent synchrotron radiation (CSR), synchrotron radiation (SR), low gain FEL oscillator, and high gain SASE FEL. In this paper, we study the characteristics of the 4 kinds of THz light sources.

  2. Analysis of heat-affected zone phase transformations using in situ spatially resolved x-ray diffraction with synchrotron radiation

    SciTech Connect

    Elmer, J.W.; Wong, J.; Froeba, M.; Waide, P.A.; Larson, E.M.

    1996-03-01

    Spatially resolved X-ray diffraction (SRXRD) consists of producing a submillimeter size X-ray beam from an intense synchrotron radiation source to perform real-time diffraction measurements on solid materials. This technique was used int his study to investigate the crystal phases surrounding a liquid weld pool in commercial purity titanium and to determine the location of the phase boundary separating the high-temperature body-centered-cubic (bcc) {beta} phase from the low-temperature hexagonal-close-packed (hcp) {alpha} phase. The experiments were carried out at the Stanford Synchrotron Radiation Laboratory (SSRL) using a 0.25 x 0.50 mm X-ray probe that could be positioned with 10-{micro}m precision on the surface of a quasistationary gas tungsten arc weld (GTAW). The SRXRD results showed characteristic hcp, bcc, and liquid diffraction patterns at various points along the sample, starting from the base metal through the heat-affected zone (HAZ) and into the weld pool, respectively. Analyses of the SRXRD data show the coexistence of bcc and hcp phases in the partially transformed (outer) region of the HAZ and single-phase bcc in the fully transformed (inner) region of the HAZ. Postweld metallographic examinations of the HAZ, combined with a conduction-based thermal model of the weld, were correlated with the SRXRD results. Finally, analysis of the diffraction intensities of the hcp and bcc phases was performed on the SRXRD data to provide additional information about the microstructural conditions that may exist in the HAZ at temperature during welding. This work represents the first direct in situ mapping of phase boundaries in fusion welds.

  3. Vacuum and magnetic field constraints in a H -/light ion synchrotron

    NASA Astrophysics Data System (ADS)

    Arduini, G.; Martin, R. L.; Rossi, S.; Silari, M.

    1994-08-01

    Acceleration of H - ions in a synchrotron imposes severe restrictions on the level of residual pressure in the vacuum chamber and the maximum magnetic field in the magnets of the ring. Significant vacuum requirements are also imposed by the acceleration of ions. This paper discusses these two aspects of the design of a combined H -/light ion synchrotron for radiation therapy. The fractional loss of the accelerated beam induced by the two processes is evaluated on the basis of a general treatment of the physics of these phenomena. The values of the vacuum and magnetic field necessary for normal operation of the machine are specified and a discussion is given of the behaviour of the above quantities as a function of several parameters such as beam energy, composition and pressure of the residual gas in the vacuum chamber and beam extraction time.

  4. Chacterization and application of a GE amorphous silicon flat panel detector in a synchrotron light source.

    SciTech Connect

    Lee, J. H.; Miceli, A.; Almer, J.; Bernier, J.; Chapman, K.; Chupas, P.; Haeffner, D.; Lee, P. L.; Lienert, U.; Aydiner, C.; Vera, G.; Kump, K.; LANL; GE Healthcare

    2007-01-01

    Characterization, in the language of synchrotron radiation, was performed on a GE Revolution 41RT flat panel detector using the X-ray light source at the Advanced Photon Source (APS). The detector has an active area of 41 x 41 cm{sup 2} with 200 x 200 {micro}m{sup 2} pixel size. The nominal working photon energy is around 80 keV. Modulation transfer function (MTF) was measured in terms of line spread function (LSF) using a 25 {micro}m x 1 cm tungsten slit. Memory effects of the detector elements, called lag, were also measured. The large area and fast data capturing rate - 8 fps in unbinned mode, 30 fps in binned or region of interest (ROI) mode - make the GE flat panel detector a unique and very versatile detector for synchrotron experiments. In particular, we present data from pair distribution function (PDF) measurements to demonstrate the special features of this detector.

  5. Magnetic properties of the ALS (Advanced Light Source) booster synchrotron engineering model magnets

    SciTech Connect

    Keller, R.; Green, M.I.; Hoyer, E.; Koo, Y.M.; Luchini, K.; Marks, S.; Milburn, J.; Nelson, D.H.

    1989-03-01

    The Advanced Light Source (ALS) at Lawrence Berkeley Laboratory is designed to be a third-generation electron storage ring producing high-brightness VUV and X-ray radiation from wiggler and undulator insertion devices. Engineering models of all lattice magnets that are to be installed in the storage ring and its booster synchrotron have been built and are being tested to verify their performance. This paper is concerned with the magnets that form the booster lattice: dipoles, quadrupoles, sextupoles, and corrector dipoles (steerers). After a brief outline of measurement techniques and equipment, the major design parameters of these magnets are listed. Measured effective lengths and multipole field errors are then given for each type. All engineering models meet the specifications, and tracking studies including the measured systematic field errors show acceptable performance of the booster synchrotron; hence the designs are qualified for production. 3 refs., 7 figs., 4 tabs.

  6. Synchrotron Vacuum Ultraviolet Light and Soft X-Ray Radiation Effects on Aluminized Teflon FEP Investigated

    NASA Technical Reports Server (NTRS)

    Dever, Joyce A.; Townsend, Jacqueline A.; Gaier, James R.; Jalics, Alice I.

    1999-01-01

    Since the Hubble Space Telescope (HST) was deployed in low Earth orbit in April 1990, two servicing missions have been conducted to upgrade its scientific capabilities. Minor cracking of second-surface metalized Teflon FEP (DuPont; fluorinated ethylene propylene) surfaces from multilayer insulation (MLI) was first observed upon close examination of samples with high solar exposure retrieved during the first servicing mission, which was conducted 3.6 years after deployment. During the second HST servicing mission, 6.8 years after deployment, astronaut observations and photographic documentation revealed significant cracks in the Teflon FEP layer of the MLI on both the solar- and anti-solar-facing surfaces of the telescope. NASA Goddard Space Flight Center directed the efforts of the Hubble Space Telescope MLI Failure Review Board, whose goals included identifying the low-Earth-orbit environmental constituent(s) responsible for the cracking and embrittling of Teflon FEP which was observed during the second servicing mission. The NASA Lewis Research Center provided significant support to this effort. Because soft x-ray radiation from solar flares had been considered as a possible cause for the degradation of the mechanical properties of Teflon FEP (ref. 1), the effects of soft xray radiation and vacuum ultraviolet light on Teflon FEP were investigated. In this Lewisled effort, samples of Teflon FEP with a 100-nm layer of vapor-deposited aluminum (VDA) on the backside were exposed to synchrotron radiation of various vacuum ultraviolet and soft x-ray wavelengths between 18 nm (69 eV) and 0.65 nm (1900 eV). Synchrotron radiation exposures were conducted using the National Synchrotron Light Source at Brookhaven National Laboratory. Samples of FEP/VDA were exposed with the FEP surface facing the synchrotron beam. Doses and fluences were compared with those estimated for the 20-yr Hubble Space Telescope mission.

  7. SESAME-A 3rd Generation Synchrotron Light Source for the Middle East

    NASA Astrophysics Data System (ADS)

    Winick, Herman

    2010-02-01

    Developed under the auspices of UNESCO and modeled on CERN, SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) is an international research center in construction in Jordan. It will enable world class research by scientists from the region, reversing the brain drain. It will also build bridges between diverse societies, contributing to a culture of peace through international cooperation in science. The centerpiece is a synchrotron light source originating from BESSY I, a gift by Germany. The upgraded machine, a 2.5 GeV 3rd Generation Light Source (133m circumference, 26nm-rad emittance and 12 places for insertion devices), will provide light from infra-red to hard X-rays, offering excellent opportunities to train local scientists and attract those working abroad to return. The SESAME Council meets twice each year and presently has nine Members (Bahrain, Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestinian Authority, Turkey). Members have responsibility for the project and provide the annual operations budget (1.5M US dollars in 2009, expected to rise to about 5M when operation starts in 2012-13). Jordan provided the site, building, and infrastructure. A staff of 20 is installing the 0.8 GeV BESSY I injection system. The facility will have the capacity to serve 30 or more experiments operating simultaneously. See www.sesame.org.jo )

  8. New methods in time-resolved Laue pump-probe crystallography at synchrotron sources.

    PubMed

    Coppens, Philip; Fournier, Bertrand

    2015-03-01

    Newly developed methods for time-resolved studies using the polychromatic and in particular the pink-Laue technique, suitable for medium and small-size unit cells typical in chemical crystallography, are reviewed. The order of the sections follows that of a typical study, starting with a description of the pink-Laue technique, followed by the strategy of data collection for analysis with the RATIO method. Novel procedures are described for spot integration, orientation matrix determination for relatively sparse diffraction patterns, scaling of multi-crystal data sets, use of Fourier maps for initial assessment and analysis of results, and least-squares refinement of photo-induced structural and thermal changes. In the calculation of Fourier maps a ground-state structure model, typically based on monochromatic results, is employed as reference, and the laser-ON structure factors for the Fourier summations are obtained by multiplying the reference ground-state structure factors by the square root of the experimental ON/OFF ratios. A schematic of the procedure followed is included in the conclusion section. PMID:25723930

  9. SESAME — A 3rd Generation Synchrotron Light Source for the Middle East

    NASA Astrophysics Data System (ADS)

    Å°lkü, Dinçer; Rahighi, Javad; Winick, Herman

    2007-01-01

    SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) will be the Middle East's first international research center. It is a cooperative venture by the scientists and governments of the region with founding members Bahrain, Egypt, Israel, Jordan, Pakistan, Palestine Authority, and Turkey. Iran is in the process of finalizing its formal membership. Other countries (Cyprus, Morocco, and the United Arab Emirates) are also expected to join. The permanent Council of member states has full responsibility for the project. Members provide the annual operating budget. Observer countries are Germany, Greece, Italy, Kuwait, Portugal, Russian Federation, Sweden, the UK, and the US. SESAME is being developed under the umbrella of UNESCO. Jordan was selected as the building site. SESAME will offer excellent opportunities for training of Middle East scientists and attract those working abroad to consider returning. SESAME will be a 2.5GeV 3rd Generation light source (emittance 26nm-rad, circumference ˜133m), providing excellent performance for structural molecular biology, molecular environmental science, surface and interface science, microelectromechanical devices, x-ray imaging, archaeological microanalysis, and materials characterization. It will cover a broad spectral range from the infrared to hard x-rays and will have 12 straight sections for insertion devices (average length 2.75m). The injector will be the BESSY I 0.8 GeV booster synchrotron which has been given as a gift from Germany. Four committees advise the Council and assist in developing the technical design, beam lines, user community, and scientific Program. The SESAME building, now in construction with funds and a site provided by Jordan, is scheduled for completion in late 2006 after which the BESSY I injector will be installed. First stored beam in the new 2.5 GeV ring is planned for 2009 with six initial beamlines planned. Some beamlines will be built by member countries

  10. SESAME - A 3rd Generation Synchrotron Light Source for the Middle East

    NASA Astrophysics Data System (ADS)

    U˝Lkü, Dinçer; Rahighi, Javad; Winick, Herman

    2007-01-01

    SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) will be the Middle East's first international research center. It is a cooperative venture by the scientists and governments of the region with founding members Bahrain, Egypt, Israel, Jordan, Pakistan, Palestine Authority, and Turkey. Iran is in the process of finalizing its formal membership. Other countries (Cyprus, Morocco, and the United Arab Emirates) are also expected to join. The permanent Council of member states has full responsibility for the project. Members provide the annual operating budget. Observer countries are Germany, Greece, Italy, Kuwait, Portugal, Russian Federation, Sweden, the UK, and the US. SESAME is being developed under the umbrella of UNESCO. Jordan was selected as the building site. SESAME will offer excellent opportunities for training of Middle East scientists and attract those working abroad to consider returning. SESAME will be a 2.5GeV 3rd Generation light source (emittance 26nm-rad, circumference ~133m), providing excellent performance for structural molecular biology, molecular environmental science, surface and interface science, microelectromechanical devices, x-ray imaging, archaeological microanalysis, and materials characterization. It will cover a broad spectral range from the infrared to hard x-rays and will have 12 straight sections for insertion devices (average length 2.75m). The injector will be the BESSY I 0.8 GeV booster synchrotron which has been given as a gift from Germany. Four committees advise the Council and assist in developing the technical design, beam lines, user community, and scientific Program. The SESAME building, now in construction with funds and a site provided by Jordan, is scheduled for completion in late 2006 after which the BESSY I injector will be installed. First stored beam in the new 2.5 GeV ring is planned for 2009 with six initial beamlines planned. Some beamlines will be built by member countries

  11. SESAME - A 3rd Generation Synchrotron Light Source for the Middle East

    SciTech Connect

    Ulkue, Dincer; Rahighi, Javad; Winick, Herman

    2007-01-19

    SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) will be the Middle East's first international research center. It is a cooperative venture by the scientists and governments of the region with founding members Bahrain, Egypt, Israel, Jordan, Pakistan, Palestine Authority, and Turkey. Iran is in the process of finalizing its formal membership. Other countries (Cyprus, Morocco, and the United Arab Emirates) are also expected to join. The permanent Council of member states has full responsibility for the project. Members provide the annual operating budget. Observer countries are Germany, Greece, Italy, Kuwait, Portugal, Russian Federation, Sweden, the UK, and the US. SESAME is being developed under the umbrella of UNESCO. Jordan was selected as the building site. SESAME will offer excellent opportunities for training of Middle East scientists and attract those working abroad to consider returning. SESAME will be a 2.5GeV 3rd Generation light source (emittance 26nm-rad, circumference {approx}133m), providing excellent performance for structural molecular biology, molecular environmental science, surface and interface science, microelectromechanical devices, x-ray imaging, archaeological microanalysis, and materials characterization. It will cover a broad spectral range from the infrared to hard x-rays and will have 12 straight sections for insertion devices (average length 2.75m). The injector will be the BESSY I 0.8 GeV booster synchrotron which has been given as a gift from Germany. Four committees advise the Council and assist in developing the technical design, beam lines, user community, and scientific Program. The SESAME building, now in construction with funds and a site provided by Jordan, is scheduled for completion in late 2006 after which the BESSY I injector will be installed. First stored beam in the new 2.5 GeV ring is planned for 2009 with six initial beamlines planned. Some beamlines will be built by member

  12. BioCARS: a synchrotron resource for time-resolved X-ray science

    PubMed Central

    Graber, T.; Anderson, S.; Brewer, H.; Chen, Y.-S.; Cho, H. S.; Dashdorj, N.; Henning, R. W.; Kosheleva, I.; Macha, G.; Meron, M.; Pahl, R.; Ren, Z.; Ruan, S.; Schotte, F.; Šrajer, V.; Viccaro, P. J.; Westferro, F.; Anfinrud, P.; Moffat, K.

    2011-01-01

    BioCARS, a NIH-supported national user facility for macromolecular time-resolved X-ray crystallography at the Advanced Photon Source (APS), has recently completed commissioning of an upgraded undulator-based beamline optimized for single-shot laser-pump X-ray-probe measurements with time resolution as short as 100 ps. The source consists of two in-line undulators with periods of 23 and 27 mm that together provide high-flux pink-beam capability at 12 keV as well as first-harmonic coverage from 6.8 to 19 keV. A high-heat-load chopper reduces the average power load on downstream components, thereby preserving the surface figure of a Kirkpatrick–Baez mirror system capable of focusing the X-ray beam to a spot size of 90 µm horizontal by 20 µm vertical. A high-speed chopper isolates single X-ray pulses at 1 kHz in both hybrid and 24-bunch modes of the APS storage ring. In hybrid mode each isolated X-ray pulse delivers up to ∼4 × 1010 photons to the sample, thereby achieving a time-averaged flux approaching that of fourth-generation X-FEL sources. A new high-power picosecond laser system delivers pulses tunable over the wavelength range 450–2000 nm. These pulses are synchronized to the storage-ring RF clock with long-term stability better than 10 ps RMS. Monochromatic experimental capability with Biosafety Level 3 certification has been retained. PMID:21685684

  13. BioCARS: a synchrotron resource for time-resolved X-ray science

    SciTech Connect

    Graber, T.; Anderson, S.; Brewer, H.; Chen, Y.-S.; Cho, H.; Dashdorj, N.; Henning, R.W.; Kosheleva, I.; Macha, G.; Meron, M.; Pahl, R.; Ren, Z.; Ruan, S.; Schotte, F.; Srajer, V.; Viccaro, P.J.; Westferro, F.; Anfinrud, P.; Moffat, K.

    2011-08-16

    BioCARS, a NIH-supported national user facility for macromolecular time-resolved X-ray crystallography at the Advanced Photon Source (APS), has recently completed commissioning of an upgraded undulator-based beamline optimized for single-shot laser-pump X-ray-probe measurements with time resolution as short as 100 ps. The source consists of two in-line undulators with periods of 23 and 27 mm that together provide high-flux pink-beam capability at 12 keV as well as first-harmonic coverage from 6.8 to 19 keV. A high-heat-load chopper reduces the average power load on downstream components, thereby preserving the surface figure of a Kirkpatrick-Baez mirror system capable of focusing the X-ray beam to a spot size of 90 {micro}m horizontal by 20 {micro}m vertical. A high-speed chopper isolates single X-ray pulses at 1 kHz in both hybrid and 24-bunch modes of the APS storage ring. In hybrid mode each isolated X-ray pulse delivers up to {approx}4 x 10{sup 10} photons to the sample, thereby achieving a time-averaged flux approaching that of fourth-generation X-FEL sources. A new high-power picosecond laser system delivers pulses tunable over the wavelength range 450-2000 nm. These pulses are synchronized to the storage-ring RF clock with long-term stability better than 10 ps RMS. Monochromatic experimental capability with Biosafety Level 3 certification has been retained.

  14. BioCARS: a synchrotron resource for time-resolved X-ray science.

    PubMed

    Graber, T; Anderson, S; Brewer, H; Chen, Y S; Cho, H S; Dashdorj, N; Henning, R W; Kosheleva, I; Macha, G; Meron, M; Pahl, R; Ren, Z; Ruan, S; Schotte, F; Srajer, V; Viccaro, P J; Westferro, F; Anfinrud, P; Moffat, K

    2011-07-01

    BioCARS, a NIH-supported national user facility for macromolecular time-resolved X-ray crystallography at the Advanced Photon Source (APS), has recently completed commissioning of an upgraded undulator-based beamline optimized for single-shot laser-pump X-ray-probe measurements with time resolution as short as 100 ps. The source consists of two in-line undulators with periods of 23 and 27 mm that together provide high-flux pink-beam capability at 12 keV as well as first-harmonic coverage from 6.8 to 19 keV. A high-heat-load chopper reduces the average power load on downstream components, thereby preserving the surface figure of a Kirkpatrick-Baez mirror system capable of focusing the X-ray beam to a spot size of 90 µm horizontal by 20 µm vertical. A high-speed chopper isolates single X-ray pulses at 1 kHz in both hybrid and 24-bunch modes of the APS storage ring. In hybrid mode each isolated X-ray pulse delivers up to ~4 × 10(10) photons to the sample, thereby achieving a time-averaged flux approaching that of fourth-generation X-FEL sources. A new high-power picosecond laser system delivers pulses tunable over the wavelength range 450-2000 nm. These pulses are synchronized to the storage-ring RF clock with long-term stability better than 10 ps RMS. Monochromatic experimental capability with Biosafety Level 3 certification has been retained. PMID:21685684

  15. A Bragg Magnifier with Sub-μm Resolution Using High Energy Synchrotron Light

    NASA Astrophysics Data System (ADS)

    Stampanoni, Marco; Borchert, G. L.; Abela, R.; Rüegsegger, P.

    2003-01-01

    X-ray computer microtomography using synchrotron light (SRμCT) has proven to be a highly powerful method in many fields of modern research as medicine, biology and material science. Presently used instruments, however, are limited to about 1μm resolution at a total efficiency of a few percent, due to the properties of the scintillator, the optical light transfer, and the CCD granularity. To overcome these limitations we have realized a novel approach based on extremely asymmetrical Bragg reflection. Our instrument, the "Bragg Magnifier" combines two asymmetrically cut Si crystals, mounted close to each other on two rotation and adjustment units. It is installed at the Materials Science Beamline of the Swiss Light Source (SLS). It operates at favorably high energies between 21 keV and 23 keV. In a first experiment using a human bone trabecula a two-dimensional magnification factor of 100×100 was achieved yielding a spatial resolution of 140nm.

  16. A high-average power femtosecond laser for synchrotron light source applications

    NASA Astrophysics Data System (ADS)

    Wilcox, R. B.; Schoenlein, R. W.

    2007-02-01

    We describe a 60W, 70fs, 20kHz Ti:sapphire CPA laser system using cryogenically-cooled amplifiers, currently operating at the Advanced Light Source at LBNL. The system consists of an oscillator, a 20 kHz regenerative preamplifier, and two power amplifiers to produce two output beams, each at 30W. Each power amp can be pumped by two 90 Watt, 10 kHz, diode-pumped, doubled YLF lasers simultaneously (for 10 kHz) or interleaved in time (for 20 kHz). The regen is pumped at 20 kHz and 60W, producing 8W output which is split between the power amps. To maintain the crystals near the thermal conductivity peak at ~50°K, we used 300 Watt cryorefrigerators mechanically decoupled from the optical table. Pulses are compressed in a quartz transmission grating compressor, to minimize thermal distortions of the phase front typical of gold coated gratings at high power density. Transmission through the compressor is >80%, using a single 100 x 100mm grating. One of the 30W output beams is used to produce 70fs electron bunches in the synchrotron light source. The other is delayed by 300ns in a 12-pass Herriot cell before amplification, to be synchronized with the short light pulse from the synchrotron.

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

    SciTech Connect

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

    2004-04-15

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

  18. The role of iron in neurodegenerative disorders: insights and opportunities with synchrotron light

    PubMed Central

    Collingwood, Joanna F.; Davidson, Mark R.

    2014-01-01

    There is evidence for iron dysregulation in many forms of disease, including a broad spectrum of neurodegenerative disorders. In order to advance our understanding of the pathophysiological role of iron, it is helpful to be able to determine in detail the distribution of iron as it relates to metabolites, proteins, cells, and tissues, the chemical state and local environment of iron, and its relationship with other metal elements. Synchrotron light sources, providing primarily X-ray beams accompanied by access to longer wavelengths such as infra-red, are an outstanding tool for multi-modal non-destructive analysis of iron in these systems. The micro- and nano-focused X-ray beams that are generated at synchrotron facilities enable measurement of iron and other transition metal elements to be performed with outstanding analytic sensitivity and specificity. Recent developments have increased the scope for methods such as X-ray fluorescence mapping to be used quantitatively rather than semi-quantitatively. Burgeoning interest, coupled with technical advances and beamline development at synchrotron facilities, has led to substantial improvements in resources and methodologies in the field over the past decade. In this paper we will consider how the field has evolved with regard to the study of iron in proteins, cells, and brain tissue, and identify challenges in sample preparation and analysis. Selected examples will be used to illustrate the contribution, and future potential, of synchrotron X-ray analysis for the characterization of iron in model systems exhibiting iron dysregulation, and for human cases of neurodegenerative disorders including Alzheimer’s disease, Parkinson’s disease, Friedreich’s ataxia, and amyotrophic lateral sclerosis. PMID:25191270

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

    SciTech Connect

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

    2014-04-24

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

  20. The scanning transmission microscope at the NSLS (National Synchrotron Light Source)

    SciTech Connect

    Rarback, H.; Buckley, C.; Goncz, K.; Ade, H.; Anderson, E.; Attwood, D.; Batson, P.; Hellman, S.; Jacobsen, C.; Kern, D.; Kirz, J.; Lindaas, S.; McNulty,I.; Oversluizen, M.; Rivers, M.; Rothman, S.; Shu, D.; Tang, Eshang; State Univ. of New York, Stony Brook, NY . Dept. of Physics; Lawrence Berkeley Lab., CA; State Univ. of New York, Stony Brook, NY . Dep

    1989-01-01

    The scanning transmission soft x-ray microscope (STXM), that has been under development at the National Synchrotron Light Source has been substantially upgraded for operation with the X1 undulator. The principal new features are: optical prefocusing, using a visible light interferometer, a dedicated VAXstation 3200 with a more user friendly and flexible software system for image acquisition and analysis, a flow cell that makes it possible not only to keep the specimen wet during exposure, but to change the fluid around the specimen as well, and a more compact proportional counter that is capable of counting rates of several MHz. In conjunction with new zone plates of better resolution and higher efficiency, the microscope is ready for a period of extended use in biological imaging. 9 refs., 6 figs.

  1. Using synchrotron light to accelerate EUV resist and mask materials learning

    NASA Astrophysics Data System (ADS)

    Naulleau, Patrick; Anderson, Christopher N.; Baclea-an, Lorie-Mae; Denham, Paul; George, Simi; Goldberg, Kenneth A.; Jones, Gideon; McClinton, Brittany; Miyakawa, Ryan; Mochi, Iacopo; Montgomery, Warren; Rekawa, Seno; Wallow, Tom

    2011-03-01

    As commercialization of extreme ultraviolet lithography (EUVL) progresses, direct industry activities are being focused on near term concerns. The question of long term extendibility of EUVL, however, remains crucial given the magnitude of the investments yet required to make EUVL a reality. Extendibility questions are best addressed using advanced research tools such as the SEMATECH Berkeley microfield exposure tool (MET) and actinic inspection tool (AIT). Utilizing Lawrence Berkeley National Laboratory's Advanced Light Source facility as the light source, these tools benefit from the unique properties of synchrotron light enabling research at nodes generations ahead of what is possible with commercial tools. The MET for example uses extremely bright undulator radiation to enable a lossless fully programmable coherence illuminator. Using such a system, resolution enhancing illuminations achieving k1 factors of 0.25 can readily be attained. Given the MET numerical aperture of 0.3, this translates to an ultimate resolution capability of 12 nm. Using such methods, the SEMATECH Berkeley MET has demonstrated resolution in resist to 16-nm half pitch and below in an imageable spin-on hard mask. At a half pitch of 16 nm, this material achieves a line-edge roughness of 2 nm with a correlation length of 6 nm. These new results demonstrate that the observed stall in ultimate resolution progress in chemically amplified resists is a materials issue rather than a tool limitation. With a resolution limit of 20-22 nm, the CAR champion from 2008 remains as the highest performing CAR tested to date. To enable continued advanced learning in EUV resists, SEMATECH has initiated a plan to implement a 0.5 NA microfield tool at the Advanced Light Source synchrotron facility. This tool will be capable of printing down to 8-nm half pitch.

  2. A Spatially Resolved Study of the Synchrotron Emission and Titanium in Tycho’s Supernova Remnant Using NuSTAR

    NASA Astrophysics Data System (ADS)

    Lopez, Laura A.; Grefenstette, Brian W.; Reynolds, Stephen P.; An, Hongjun; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Eriksen, Kristoffer A.; Fryer, Chris L.; Hailey, Charles J.; Harrison, Fiona A.; Madsen, Kristin K.; Stern, Daniel K.; Zhang, William W.; Zoglauer, Andreas

    2015-12-01

    We report results from deep observations (˜750 ks) of Tycho's supernova remnant (SNR) with NuSTAR. Using these data, we produce narrow-band images over several energy bands to identify the regions producing the hardest X-rays and to search for radioactive decay line emission from 44Ti. We find that the hardest (>10 keV) X-rays are concentrated in the southwest of Tycho, where recent Chandra observations have revealed high emissivity “stripes” associated with particles accelerated to the knee of the cosmic-ray spectrum. We do not find evidence of 44Ti, and we set limits on its presence and distribution within the SNR. These limits correspond to an upper-limit 44Ti mass of M44 < 2.4 × 10-4 M⊙ for a distance of 2.3 kpc. We perform a spatially resolved spectroscopic analysis of 66 regions across Tycho. We map the best-fit rolloff frequency of the hard X-ray spectra, and we compare these results to measurements of the shock expansion and ambient density. We find that the highest energy electrons are accelerated at the lowest densities and in the fastest shocks, with a steep dependence of the rolloff frequency with shock velocity. Such a dependence is predicted by models where the maximum energy of accelerated electrons is limited by the age of the SNR rather than by synchrotron losses, but this scenario requires far lower magnetic field strengths than those derived from observations in Tycho. One way to reconcile these discrepant findings is through shock obliquity effects, and future observational work is necessary to explore the role of obliquity in the particle acceleration process.

  3. The Advanced Light Source at Lawrence Berkeley Laboratory: A high-brightness soft x-ray synchrotron-radiation facility

    SciTech Connect

    Schlachter, A.S.; Robinson, A.L.

    1990-07-01

    The Advanced Light Source, a third-generation national synchrotron-radiation facility now under construction at the Lawrence Berkeley Laboratory, is scheduled to begin serving qualified users across a broad spectrum of research areas in the spring of 1993. Based on a low-emittance electron storage ring optimized to operate at 1.5 GeV, the ALS will have 10 long straight sections available for insertion devices (undulators and wigglers) and 24 high-quality bend-magnet ports. The short pulse width (30--50 ns) will be ideal for time-resolved measurements. Undulators will generate high-brightness soft x-ray and ultraviolet (XUV) radiation from below 20 eV to above 2 keV. Wigglers and bend magnets will extend the spectrum by generating high fluxes of hard x-rays to photon energies above 10 keV. The ALS will support an extensive research program in which XUV radiation is used to study matter in all its varied gaseous, liquid, and solid forms. The high brightness will open new areas of research in the materials sciences, such as spatially resolved spectroscopy (spectromicroscopy). Biological applications will include x-ray microscopy with element-specific sensitivity in the water window of the spectrum where water is much more transparent than protein. The ALS will be an excellent research tool for atomic physics and chemistry because the high flux will allow measurements to be made with tenuous gas-phase targets. 8 refs., 7 figs., 3 tabs.

  4. Analysis of Old Copper Synchrotron Light Absorbers from the Stanford Positron Electron Accelerating Ring

    SciTech Connect

    Marshall, S.R.; Scott, B.; /SLAC

    2005-12-15

    Synchrotron light absorbers intercept synchrotron radiation to protect chamber walls from excessive heat. When subjected to the high temperature of the beam, these absorbers undergo thermal stress. If the stress is too great or fatigues the material, the absorbers may fail. These absorbers are designed to last the lifetime of the machine. Any premature cracking could result in a leak and, consequently, loss of the ultra high vacuum environment. Using secondary and backscattered electron techniques, several sections of a used copper absorber were analyzed for material damage. Chemical analyses were performed on these samples as well. Comparing the unexposed sections to the sections exposed to the electron beam, few cracks were seen in the copper. However, the exposed samples showed heavy surface damage, in addition to crevices that could eventually result in material failure. Significant corrosion was also evident along the water cooling passage of the samples. These findings suggest that further investigation and periodic inspection of absorbers in SPEAR3 are necessary to control corrosion of the copper.

  5. Pseudo-Single-Bunch with Adjustable Frequency: A New Operation Mode for Synchrotron Light Sources

    NASA Astrophysics Data System (ADS)

    Sun, C.; Portmann, G.; Hertlein, M.; Kirz, J.; Robin, D. S.

    2012-12-01

    We present the concept and results of pseudo-single-bunch (PSB) operation—a new operational mode at the advanced light source—that can greatly expand the capabilities of synchrotron light sources to carry out dynamics and time-of-flight experiments. In PSB operation, a single electron bunch is displaced transversely from the other electron bunches using a short-pulse, high-repetition-rate kicker magnet. Experiments that require light emitted only from a single bunch can stop the light emitted from the other bunches using a collimator. Other beam lines will only see a small reduction in flux due to the displaced bunch. As a result, PSB eliminates the need to schedule multibunch and timing experiments during different running periods. Furthermore, the time spacing of PSB pulses can be adjusted from milliseconds to microseconds with a novel “kick-and-cancel” scheme, which can significantly alleviate complications of using high-power choppers and substantially reduce the rate of sample damage.

  6. Synchrotron radiation shielding design for the Brockhouse sector at the Canadian light source

    NASA Astrophysics Data System (ADS)

    Bassey, Bassey; Moreno, Beatriz; Gomez, Ariel; Ahmed, Asm Sabbir; Ullrich, Doug; Chapman, Dean

    2014-05-01

    At the Canadian Light Source (CLS), the plans for the construction of three beamlines under the Brockhouse Project are underway. The beamlines, to be classified under the CLS Phase III beamlines, will comprise of a wiggler and an undulator, and will be dedicated to x-ray diffraction and scattering experiments. The energy range of these beamlines will be 7-22 keV (low energy wiggler beamline), 20-94 keV (high energy wiggler beamline), and 5-21 keV (undulator beamline). The beamlines will have a total of five hutches. Presented is the shielding design against target scattered white and monochromatic synchrotron radiations for these beamlines. The shielding design is based on: scatter target material-water, dose object-anthropomorphic phantom of the adult human (anteroposterior-AP geometry), and shielding thicknesses of steel and lead that will drop the radiation leakage from the hutches to below 0.5 μSv/h.

  7. Photon stimulated desorption from a vacuum chamber at the National Synchrotron Light Source

    SciTech Connect

    Kobari, T.; Halama, H.J.

    1987-07-01

    In our search for surfaces exhibiting the lowest photon stimulated desorption, we have exposed a 3-m-long beam tube to photons from the vacuum ultraviolet ring of the National Synchrotron Light Source having critical energy of --500 eV. Desorption of H/sub 2/, CH/sub 4/, CO, and CO/sub 2/, which are the main gas species, was studied as a function of the beam dose for the following surface treatments: standard chemical cleaning, Ar 10% O/sub 2/ glow discharge, N/sub 2/ glow discharge, and radio frequency glow discharge using O/sub 2/ disassociation. In addition, we measured the desorption as a function of vertical collimator position. N/sub 2/ glow discharge treatment yielded the lowest desorption.

  8. Storage Rings for Science with: Electron-Positron Collisions, Hadron Collisions and Synchrotron Light

    SciTech Connect

    Ozaki,S.

    2009-05-04

    The author is honored to receive the 2009 Robert Wilson Prize and the recognition that comes with it. The citation for the prize reads, 'For his outstanding contribution to the design and construction of accelerators that has led to the realization of major machines for fundamental science on two continents and his promotion of international collaboration.' In this article, he will discuss the two construction projects, which he led, one (TRISTAN e{sup +}e{sup -} Collider at KEK) in Japan and the other (RHIC at BNL) in the USA, covering project issues and lessons learned from these projects. Although both of them were built on separate continents, it is interesting to note that they are both built on long off-shore islands. He will also add comments on his recent engagement in the development of the Conceptual Design for the National Synchrotron Light Source II (NSLS-II).

  9. Environmental Remediation Science at Beamline X26A at the National Synchrotron Light Source- Final Report

    SciTech Connect

    Bertsch, Paul

    2013-11-07

    The goal of this project was to provide support for an advanced X-ray microspectroscopy facility at the National Synchrotron Light Source, Brookhaven National Laboratory. This facility is operated by the University of Chicago and the University of Kentucky. The facility is available to researchers at both institutions as well as researchers around the globe through the general user program. This facility was successfully supported during the project period. It provided access to advanced X-ray microanalysis techniques which lead to fundamental advances in understanding the behavior of contaminants and geochemistry that is applicable to environmental remediation of DOE legacy sites as well as contaminated sites around the United States and beyond.

  10. Optical design and performance of the inelastic scattering beamline at the National Synchrotron Light Source

    SciTech Connect

    Kao, C.C.; Siddons, D.P.; Oversluizen, T.; Hastings, J.B.; Hamalainen, K.; Krisch, M.

    1994-12-31

    Phase I of the X21 beamline at the National Synchrotron Light Source was commissioned during 1993. The research program at the X21 beamline is focused on the study of electronic excitations in condensed matter with total energy resolution of 0.1 eV to 1.0 eV. The source is a 27 pole hybrid wiggler. A water-cooled horizontal focusing Si(220) monochromator and a spherically bent Si(444) analyzer were installed and commissioned. At 8 keV the energy resolution of the monochromator is about 0.7 eV, and the energy resolution of the analyzer is about 0.1 eV. Results from several selected experiments are also discussed.

  11. X-Ray Irradiation of H2O + CO Ice Mixtures with Synchrotron Light

    NASA Astrophysics Data System (ADS)

    Jiménez-Escobar, A.; Chen, Y.-J.; Ciaravella, A.; Huang, C.-H.; Micela, G.; Cecchi-Pestellini, C.

    2016-03-01

    We irradiated a (4:1) mixture of water and carbon monoxide with soft X-rays of energies up to 1.2 keV. The experiments were performed using the spherical grating monochromator beamline at National Synchrotron Radiation Research Center in Taiwan. Both monochromatic (300 and 900 eV) and broader energy fluxes (250-1200 eV) were employed. During the irradiation, the H2O + CO mixture was ionized, excited, and fragmented, producing a number of reactive species. The composition of the ice has been monitored throughout both the irradiation and warm-up phases. We identified several products, which can be related through a plausible chemical reaction scheme. Such chemistry is initiated by the injection of energetic photoelectrons that produce multiple ionization events generating a secondary electron cascade. The results have been discussed in light of a model for protoplanetary disks around young solar-type stars.

  12. Synchrotron X-Ray Microdiffraction Studies of Electromigration in Interconnect lines at the Advanced Light Source

    SciTech Connect

    Tamura, Nobumichi; Chen, Kai; Kunz, Martin

    2009-12-01

    Synchrotron polychromatic X-ray microdiffraction is a particularly suitable technique to study in situ the effect of electromigration in metal interconnects as add spatial resolution to grain orientation and strain sensitivity. This technique has been extensively used at the Advanced Light Source to monitor changes in aluminum and copper interconnect test structures while high-density current is passed into them during accelerated tests at elevated temperature. One of the principal findings is the observation of electromigration-induced plasticity in the metal lines that appear during the very early stages of electromigration. In some of the lines, high density of geometrically necessary dislocation are formed leading to additional diffusion paths causing an enhancement of electromigration effect at test temperature.

  13. Calcium Triggered Lα-H2 Phase Transition Monitored by Combined Rapid Mixing and Time-Resolved Synchrotron SAXS

    PubMed Central

    Yaghmur, Anan; Laggner, Peter; Sartori, Barbara; Rappolt, Michael

    2008-01-01

    Background Awad et al. [1] reported on the Ca2+-induced transitions of dioleoyl-phosphatidylglycerol (DOPG)/monoolein (MO) vesicles to bicontinuous cubic phases at equilibrium conditions. In the present study, the combination of rapid mixing and time-resolved synchrotron small-angle X-ray scattering (SAXS) was applied for the in-situ investigations of fast structural transitions of diluted DOPG/MO vesicles into well-ordered nanostructures by the addition of low concentrated Ca2+ solutions. Methodology/Principal Findings Under static conditions and the in absence of the divalent cations, the DOPG/MO system forms large vesicles composed of weakly correlated bilayers with a d-spacing of ∼140 Å (Lα-phase). The utilization of a stopped-flow apparatus allowed mixing these DOPG/MO vesicles with a solution of Ca2+ ions within 10 milliseconds (ms). In such a way the dynamics of negatively charged PG to divalent cation interactions, and the kinetics of the induced structural transitions were studied. Ca2+ ions have a very strong impact on the lipidic nanostructures. Intriguingly, already at low salt concentrations (DOPG/Ca2+>2), Ca2+ ions trigger the transformation from bilayers to monolayer nanotubes (inverted hexagonal phase, H2). Our results reveal that a binding ratio of 1 Ca2+ per 8 DOPG is sufficient for the formation of the H2 phase. At 50°C a direct transition from the vesicles to the H2 phase was observed, whereas at ambient temperature (20°C) a short lived intermediate phase (possibly the cubic Pn3m phase) coexisting with the H2 phase was detected. Conclusions/Significance The strong binding of the divalent cations to the negatively charged DOPG molecules enhances the negative spontaneous curvature of the monolayers and causes a rapid collapsing of the vesicles. The rapid loss of the bilayer stability and the reorganization of the lipid molecules within ms support the argument that the transition mechanism is based on a leaky fusion of the vesicles. PMID

  14. Synchrotrons: Taiwan unveils new synchrotron

    NASA Astrophysics Data System (ADS)

    Horiuchi, Noriaki

    2015-05-01

    Competitive activities around the globe to develop the world's brightest synchrotron light source have accelerated in recent years. Taiwanese scientists now aspire to be at the top of the list with the recently constructed Taiwan Photon Source.

  15. Expected Performance of the LHC Synchrotron-Light Telescope (BSRT) and Abort-Gap Monitor (BSRA)

    SciTech Connect

    Fisher, Alan; /SLAC

    2010-06-07

    This Report presents calculations of the synchrotron light from proton and lead-ion beams in the LHC at all energies from 0.45 to 7 TeV. It computes the emission from three sources: the uniform-field region of the D3 dipole, the dipole's edge field, and the short undulator just upstream. Light emitted at or near visible wavelengths is assessed for making optical measurements of transverse beam profiles and for monitoring the emptiness of the abort gap in the fill pattern. There is sufficient light for both applications, although both species pass through energy ranges in the ramp with small photon counts. Effects limiting image resolution are examined, including geometric optics, depth of field, and diffraction. The Report also considers recent suggestions that the undulator, intended to supplement the dipole for low energies, should not be ramped off at high energies and perhaps should not be used at all. We conclude that the undulator is essential at low energy for both species, but that it is possible to leave the undulator on at the cost of some blurring at intermediate energies.

  16. A Bragg Magnifier with Sub-{mu}m Resolution Using High Energy Synchrotron Light

    SciTech Connect

    Stampanoni, Marco; Borchert, G. L.; Abela, R.; Rueegsegger, P.

    2003-01-24

    X-ray computer microtomography using synchrotron light (SR{mu}CT) has proven to be a highly powerful method in many fields of modern research as medicine, biology and material science. Presently used instruments, however, are limited to about 1{mu}m resolution at a total efficiency of a few percent, due to the properties of the scintillator, the optical light transfer, and the CCD granularity. To overcome these limitations we have realized a novel approach based on extremely asymmetrical Bragg reflection. Our instrument, the 'Bragg Magnifier' combines two asymmetrically cut Si crystals, mounted close to each other on two rotation and adjustment units. It is installed at the Materials Science Beamline of the Swiss Light Source (SLS). It operates at favorably high energies between 21 keV and 23 keV. In a first experiment using a human bone trabecula a two-dimensional magnification factor of 100x100 was achieved yielding a spatial resolution of 140nm.

  17. Resolving enantiomers using the optical angular momentum of twisted light.

    PubMed

    Brullot, Ward; Vanbel, Maarten K; Swusten, Tom; Verbiest, Thierry

    2016-03-01

    Circular dichroism and optical rotation are crucial for the characterization of chiral molecules and are of importance to the study of pharmaceutical drugs, proteins, DNA, and many others. These techniques are based on the different interactions of enantiomers with circularly polarized components of plane wave light that carries spin angular momentum (SAM). For light carrying orbital angular momentum (OAM), for example, twisted or helical light, the consensus is that it cannot engage with the chirality of a molecular system as previous studies failed to demonstrate an interaction between optical OAM and chiral molecules. Using unique nanoparticle aggregates, we prove that optical OAM can engage with materials' chirality and discriminate between enantiomers. Further, theoretical results show that compared to circular dichroism, mainly based on magnetic dipole contributions, the OAM analog helical dichroism (HD) is critically dependent on fundamentally different chiral electric quadrupole contributions. Our work opens new venues to study chirality and can find application in sensing and chiral spectroscopy. PMID:26998517

  18. Resolving enantiomers using the optical angular momentum of twisted light

    PubMed Central

    Brullot, Ward; Vanbel, Maarten K.; Swusten, Tom; Verbiest, Thierry

    2016-01-01

    Circular dichroism and optical rotation are crucial for the characterization of chiral molecules and are of importance to the study of pharmaceutical drugs, proteins, DNA, and many others. These techniques are based on the different interactions of enantiomers with circularly polarized components of plane wave light that carries spin angular momentum (SAM). For light carrying orbital angular momentum (OAM), for example, twisted or helical light, the consensus is that it cannot engage with the chirality of a molecular system as previous studies failed to demonstrate an interaction between optical OAM and chiral molecules. Using unique nanoparticle aggregates, we prove that optical OAM can engage with materials’ chirality and discriminate between enantiomers. Further, theoretical results show that compared to circular dichroism, mainly based on magnetic dipole contributions, the OAM analog helical dichroism (HD) is critically dependent on fundamentally different chiral electric quadrupole contributions. Our work opens new venues to study chirality and can find application in sensing and chiral spectroscopy. PMID:26998517

  19. A MODEL STUDY OF TRANSVERSE MODE COUPLING INSTABILITY AT NATIONAL SYNCHROTRON LIGHT SOURCE-II (NSLS-II).

    SciTech Connect

    BLEDNYKH, A.; WANG, J.M.

    2005-05-15

    The vertical impedances of the preliminary designs of National Synchrotron Light Source II (NSLS-II) Mini Gap Undulators (MGU) are calculated by means of GdfidL code. The Transverse Mode Coupling Instability (TMCI) thresholds corresponding to these impedances are estimated using an analytically solvable model.

  20. ESC FY2002 Annual Report: Synchrotron-Radiation-Based Photoelectron Spectroscopy at the Advanced Light Source

    SciTech Connect

    Tobin, J G; Chung, B W; Schulze, R K; Shuh, D K

    2002-10-04

    Despite recent intensive experimental effort, the electronic structure of Pu, particularly {delta}-Pu, remains ill defined. An evaluation of our previous synchrotron-radiation-based investigation of {alpha}-Pu and {delta}-Pu has lead to a new paradigm for the interpretation of photoemission spectra of U, Np, {alpha}-Pu, {delta}-Pu and Am. This approach is founded upon a model in which spin and spin-orbit splittings are included in the picture of the 5f states and upon the observation of chiral/spin-dependent effects in non-magnetic systems. By extending a quantitative model developed for the interpretation of core level spectroscopy in magnetic systems, it is possible to predict the contributions of the individual component states within the 5-f manifold. This has lead to a remarkable agreement between the results of the model and the previously collected spectra of U, Np, Pu and Am, particularly {delta}-Pu, and to a prediction of what we might expect to see in future spin-resolving experiments.

  1. Measurement of the intensity of the beam in the abort gap at the Tevatron utilizing synchrotron light

    SciTech Connect

    Thurman-Keup, R.; Lorman, E.; Meyer, T.; Pordes, S.; De Santis, S.; /LBL, Berkeley

    2005-05-01

    This paper discusses the implementation of abort gap beam intensity monitoring at the Tevatron collider at Fermilab. There are two somewhat independent monitors which measure the intensity of the synchrotron light emitted by particles in the abort gaps. One system uses a gated Photomultiplier Tube (PMT) to measure the light intensity, and the other system uses a single lens telescope, gated image intensifier, and Charge Injection Device (CID) camera to image the beam.

  2. Multi-anvil High Pressure Facility at National Synchrotron Light Source: Then, Now, and Future

    NASA Astrophysics Data System (ADS)

    Wang, L.; Weidner, D. J.; Vaughan, M. T.; Chen, J.; Li, B.; Liebermann, R. C.

    2007-12-01

    Multi-anvil high pressure facility (Beamline X17B2) at National Synchrotron Light Source (NSLS) was the first of its kind established in the United States with the support from NSF through the Center for High Pressure Research (CHiPR, 1990 - 2002). During this period, the facility provided a fertile ground for steep growth of research on earth materials at simultaneously high pressures and temperatures. Main areas of study included the thermoelastic and structural properties of minerals, phase equilibria, rheology, acoustic velocities, kinetics of phase transformations, and physical properties of melts. The rheological and acoustic measurements at high pressures in conjunction with synchrotron were first developed at this facility, and both techniques are being adapted today by other laboratories around the world. Last five years has witnessed great increases in efficiency and productivity of this facility, a beneficiary of the construction of a permanent hutch and time-sharing mechanism made possible by NSLS, and the establishment of the Consortium for Materials Properties Research in Earth Sciences (COMPRES). While other above- mentioned areas of research continued to grow, the rheological studies of minerals experienced fast expansion through the use of two new high pressure deformation apparatus, the Deformation DIA (D-DIA) and the Rotational Drickamer apparatus (RDA, led by S. Karato from Yale Univ.) Experiments are currently being performed on various mantle minerals to derive their rheological properties. Performance of the facility will receive another boost through the addition of a monochromatic side station jointly supported by DoD, COMPRES and NSLS, and construction of the station is well underway. With continued operation of COMPRES in next five years, we will see several significant additions to the large- volume facility at NSLS: a new system for precise measurements of stress at high pressure; a 2000-ton press; D- TCup apparatus for deformation

  3. National synchrotron light source. Activity report, October 1, 1995--September 30, 1996

    SciTech Connect

    Rothman, E.Z.; Hastings, J.B.

    1997-05-01

    The hard work done by the synchrotron radiation community, in collaboration with all those using large-scale central facilities during 1995, paid off in FY 1996 through the DOE`s Presidential Scientific Facilities Initiative. In comparison with the other DOE synchrotron radiation facilities, the National Synchrotron Light Source benefited least in operating budgets because it was unable to increase running time beyond 100%-nevertheless, the number of station hours was maintained. The major thrust at Brookhaven came from a 15% increase in budget which allowed the recruitment of seven staff in the beamlines support group and permitted a step increment in the funding of the extremely long list of upgrades; both to the sources and to the beamlines. During the December 1995 shutdown, the VUV Ring quadrant around U10-U12 was totally reconstructed. New front ends, enabling apertures up to 90 mrad on U10 and U12, were installed. During the year new PRTs were in formation for the infrared beamlines, encouraged by the investment the lab was able to commit from the initiative funds and by awards from the Scientific Facilities Initiative. A new PRT, specifically for small and wide angle x-ray scattering from polymers, will start work on X27C in FY 1997 and existing PRTs on X26C and X9B working on macromolecular crystallography will be joined by new members. Plans to replace aging radio frequency cavities by an improved design, originally a painfully slow six or eight year project, were brought forward so that the first pair of cavities (half of the project for the X-Ray Ring) will now be installed in FY 1997. Current upgrades to 350 mA initially and to 438 mA later in the X-Ray Ring were set aside due to lack of funds for the necessary thermally robust beryllium windows. The Scientific Facilities Initiative allowed purchase of all 34 windows in FY 1996 so that the power upgrade will be achieved in FY 1997.

  4. A microsecond time resolved x-ray absorption near edge structure synchrotron study of phase transitions in Fe undergoing ramp heating at high pressure

    SciTech Connect

    Marini, C.; Mathon, O.; Pascarelli, S.; Occelli, F.; Torchio, R.; Recoules, V.; Loubeyre, P.

    2014-03-07

    We report a microsecond time-resolved x-ray absorption near edge structure study using synchrotron radiation to dynamically detect structural phase transitions in Fe undergoing rapid heating along a quasi-isochoric path. Within a few ms, we observed two structural phase transitions, which transform the ambient bcc phase of Fe into the fcc phase, and then into the liquid phase. This example illustrates the opportunities offered by energy dispersive x-ray absorption spectroscopy in the study of matter under extreme dynamic conditions. Advanced simulations are compared to these data.

  5. Ultra-high vacuum system of the Brookhaven National Synchrotron Light Source

    SciTech Connect

    Foerster, C.L.

    1995-12-31

    The rings of the National Synchrotron Light Source (NSLS) have been supplying light to numerous users for approximately a decade and we recently enjoyed a fully conditioned machine vacuum at design currents. A brief description of the X-Ray storage ring, the VUV storage ring and their current supply is given along with some of their features. The ultra-high vacuum system employed for the storage rings and their advantages for the necessary stored beam environments are discussed including, a brief history of time. After several hundred amp hours of stored beam current operation, very little improvement in machine performance was seen due to conditioning. Sections of the rings were vented, to dry nitrogen and replacement components were pre-baked and pre-argon glow conditioned prior to installation. Very little machine conditioning was needed to return to operation after recovering vacuum due to well established conditioning procedures. All straight sections in the X-Ray ring and the VUV ring have been filled with various insertion devices and most are fully operational. Each storage ring has a computer controlled total pressure and partial pressure monitoring system for the ring and its beam ports, to insure good vacuum.

  6. Design of a multi-bend achromat lattice for 3 GeV synchrotron light source

    NASA Astrophysics Data System (ADS)

    Kim, Eun-San

    2016-03-01

    We present a lattice design for a low-emittance and high-brilliance 3 GeV synchrotron light source that has been widely investigated in the world. We show the design results for a MBA (Multi-Bend Achromat) lattice with an emittance of 1.3 nm and 282.4 m circumference. Each cell has 5 bending magnets that consist of outer two with bending angle of 4.5° and inner three with bending angle of 7°. The lattice is designed to be flexible and consists of 12 straight sections in which one straight section has a length of 5.9 m. We have studied the dynamic aperture in the lattice with machine errors. It is shown that the designed low-emittance lattice provides sufficient dynamic aperture after COD correction. We present the results of variations of emittance, energy spread and dynamic aperture due to in-vacuum undulators in the straight sections. We performed particle tracking after the beam injection to investigate the efficiency of the injection scheme. We show the designed results of an injection scheme that shows the space allocation in injection section and the particle motions of injected beam. Our designed lattice provides a good optimization in terms of the emittance and brilliance as a light source for 3 GeV energy and circumference of 28 m.

  7. SESAME, A 3rd Generation Synchrotron Light Source for the Middle East

    SciTech Connect

    Einfeld, D.; Hasnain, S.S.; Sayers, Z.; Schopper, H.; Winick, H.; Al-Dmour, E.

    2004-05-12

    Developed under the auspices of UNESCO, SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) will be a major international research centre in the Middle East and Mediterranean region. On 6th of January 2003, the official foundation of SESAME took place. The facility is located in Allan, Jordan, 30 km North-West of Amman. As of August 2003 the Founding Members are Bahrain, Egypt, Iran, Israel, Jordan, Pakistan, Palestine, Turkey and United Arabic Emirates, representing a population of over 300 million. SESAME will be a 2.5 GeV 3rd Generation light source (emittance 24.6 nm.rad, circumference {approx}125m). About 40% of the circumference is available for insertion devices (average length 2.75m) in 13 straight sections. Beam lines are up to 36m. The site and a building are provided by Jordan. Construction started in August 2003. The scientific program will start with up to 6 beam lines: MAD Protein Crystallography, SAXS and WAXS for polymers and proteins, Powder Diffraction for material science, UV/VUV/SXR Photoelectron Spectroscopy and Photoabsorption Spectroscopy, IR Spectroscopy, and EXAFS.

  8. Resolving gas-liquid interface geometry using light field imaging

    NASA Astrophysics Data System (ADS)

    Jafek, Alexander; Belden, Jesse; Truscott, Tadd

    2014-11-01

    We present a novel approach for reconstructing the geometry of a three-dimensional specular gas-liquid interface from an image captured by a light-field camera. Whereas the scanning of a diffuse surface can be accomplished with a simple projector-camera system, the local reconstruction of a specular surface is non-unique and requires a more constrained sampling method. In our set-up, a known array of laser points is reflected by the unknown specular surface onto the image plane of a light-field camera. For each illuminated pixel, possible surfaces are generated that are defined by a depth location and local surface normal vector. We show that when the aperture is sufficiently small we can find the exact location and orientation of the local surface. Further, we present an algorithm that allows us to reconstruct a reflective surface from images that are taken with wider apertures. The algorithm searches the possible surfaces for points and normal vectors that are most consistent with each other based on input parameters. We present our simulated results with experimental validation.

  9. Photon-number-resolved detection of photon-subtracted thermal light.

    PubMed

    Zhai, Yanhua; Becerra, Francisco E; Glebov, Boris L; Wen, Jianming; Lita, Adriana E; Calkins, Brice; Gerrits, Thomas; Fan, Jingyun; Nam, Sae Woo; Migdall, Alan

    2013-07-01

    We examine the photon statistics of photon-subtracted thermal light using photon-number-resolved detection. We demonstrate experimentally that the photon number distribution transforms from a Bose-Einstein distribution to a Poisson distribution as the number of subtracted photons increases. We also show that second- and higher-order photon correlation functions can be directly determined from the photon-number-resolved detection measurements of a single optical beam. PMID:23811867

  10. Time-resolved spectral investigations of laser light induced microplasma

    NASA Astrophysics Data System (ADS)

    Nánai, L.; Hevesi, I.

    1992-01-01

    The dynamical and spectral properties of an optical breakdown microplasma created by pulses of different lasers on surfaces of insulators (KCI), metals (Cu) and semiconductors (V 2O 5), have been investigated. Experiments were carried out in air and vacuum using different wavelengths (λ = 0.694μm, type OGM-20,λ = 1.06μm with a home-made laser based on neodymium glass crystal, and λ = 10.6μm, similarly home-made) and pulse durations (Q-switched and free-running regimes). To follow the integral, dynamical and spectral characteristics of the luminous spot of microplasma we have used fast cameras (SFR-2M, IMACON-HADLAND), a high speed spectral camera (AGAT-2) and a spectrograph (STE-1). It has been shown that the microplasma consists of two parts: fast front (peak) with τ≈100 ns and slow front (tail) with τ≈1μs durations. The detonation front speed is of the order of ≈10 5 cm s -1 and follows the temporal dependence of to t0.4. It depends on the composition of the surrounding gas and its pressure and could be connected with quick evaporation of the material investigated (peak) and optical breakdown of the ambient gaseous atmosphere (tail). From the delay in appearance of different characteristic spectral lines of the target material and its gaseous surrounding we have shown that the evolution of the microplasma involves evaporation and ionization of the atoms of the parent material followed by optical breakdown due to the incident and absorbed laser light, together with microplasma expansion.

  11. Aluminium ultrahigh vacuum system for the 3 GeV TPS synchrotron light source

    NASA Astrophysics Data System (ADS)

    Hsiung, G. Y.; Chang, C. C.; Chen, C. L.; Wu, L. H.; Cheng, C. M.; Chan, C. K.; Yang, Y. C.; Hsueh, H. P.; Hsu, S. N.; Chen, J. R.

    2013-06-01

    The 3-GeV Taiwan Photon Source (TPS) is a large accelerator and synchrotron light source of circumference 518.4 m. The electron storage ring of TPS requires an ultrahigh-vacuum pressure per beam current less than 2×10-10 Pa/mA in the beam duct to maintain a long life of the circulating beam without scattering of ions by residual gases. Aluminium alloys used for the beam ducts have a benefit of greater thermal conductivity that simplifies the structure of vacuum vessels built with the cooling components. Machining completely free of oil applied to the aluminium chambers followed by cleaning with ozonized water and welding in house provide a precise dimensional control within 0.3 mm and a clean surface with a small rate ~ 6.4×10-12 Pa m/s of thermal outgassing after baking at 150 °C for 24 h. The assembled ion pump with non-evaporable getter pump is capable of evacuating the chamber to a pressure < 1×10-9 Pa. The average pressure inside the duct is expected to be sufficiently small. The clean process to manufacture the aluminium ultrahigh vacuum system is described.

  12. Operation of general purpose stepping motor controllers at the National Synchrotron Light Source

    SciTech Connect

    Stubblefield, F.W.

    1986-10-01

    A prototype and four copies of a general purpose subsystem for mechanical positioning of detectors, samples, and beam line optical elements which constitute experiments at the National Synchrotron Light Source facility of Brookhaven National Laboratory have been constructed and placed into operation. Construction of a sixth subsystem is nearing completion. The subsystems effect mechanical positioning by controlling a set of stepping motors and their associated position encoders. The units are general purpose in the sense that they receive commands over a standard 9600 baud asynchronous serial line compatible with the RS-232-C electrical signal standard, generate TTL-compatible streams of stepping pulses which can be used with a wide variety of stepping motors, and read back position values from a number of different types and models of position encoder. The basic structure of the motor controller subsystem will be briefly reviewed. Short descriptions of the positioning apparatus actuated at each of the test and experiment stations employing a motor control unit are given. Additions and enhancements to the subsystem made in response to problems indicated by actual operation of the four installed units are described in more detail.

  13. Operation of general purpose stepping motor controllers at the National Synchrotron Light Source

    SciTech Connect

    Stubblefield, F.W.

    1987-02-01

    A prototype and four copies of a general purpose subsystem for mechanical positioning of detectors, samples, and beam line optical elements which constitute experiments at the National Synchrotron Light Source facility of Brookhaven National Laboratory have been constructed and placed into operation. Construction of a sixth subsystem is nearing completion. The subsystems effect mechanical positioning by controlling a set of stepping motors and their associated position encoders. The units are general purpose in the sense that they receive commands over a standard 9600 baud asynchronous serial line compatible with the RS-232-C electrical signal standard, generate TTL-compatible streams of stepping pulses which can be used with a wide variety of stepping motors, and read back position values from a number of different types and models of position encoder. The basic structure of the motor controller subsystem is briefly reviewed. Short descriptions of the positioning apparatus actuated at each of the test and experiment stations employing a motor control unit are given. Additions and enhancements to the sub-system made in response to problems indicated by actual operation of the four installed units are described in more detail.

  14. National Synchrotron Light Source Facility Manual Maintenance Management Program. Revision 1

    SciTech Connect

    Fewell, N.

    1993-12-01

    The purpose of this program s to meet the policy and objectives for the management and performance of cost-effective maintenance and repair of the National Synchrotron Light Source, as required by the US Department of Energy order DOE 433O.4A. It is the DOE`s policy that: The maintenance management program for the NSLS be consistent with this Order and that NSLS property is maintained in a manner which promotes operational safety, worker health, environmental protection and compliance, property preservation, and cost-effectiveness while meeting the NSLS`s programmatic mission. Structures, components and systems (active and passive) that are imporant to safe operation of the NSLS shall be subject to a maintenance program to ensure that they meet or exceed their design requirements throughout the life of the NSLS. Periodic examination of structures, systems components and equipment be performed to determine deterioration or technical obsolescence which may threaten performance and/or safety. Primary responsibility, authority, and accountability for the direction and management of the maintenance program at the NSLS reside with the line management assigned direct programmatic responsibility. Budgeting and accounting for maintenance programs are consistent with DOE Orders guidance.

  15. New Perspectives for Advanced Science at the Brazilian Synchrotron Light Laboratory

    SciTech Connect

    Tolentino, Helio C.N.

    2003-01-24

    The LNLS (Laboratorio Nacional de Luz Sincrotron) is a national laboratory in Brazil that operates a 1.37 GeV storage ring for synchrotron light users since July 1997. Eleven bending magnet beamlines are open to a wide range of possibilities for research in ultra-violet and X-ray spectroscopy, single crystal and powder diffraction, magnetic and anomalous scattering, protein crystallography, X-ray fluorescence, X-ray lithography and small angle X-ray scattering. The recent conclusion of the booster injector opened the way for insertion devices to be accommodated in the four straight sections available. A multipolar wiggler, for protein crystallography using the MAD technique, is the first planned to be installed during 2003. The construction of the first LNLS undulator, for the vaccum ultra-violet and soft X-ray domain, has already started and will expand the possibilities in atomic, molecular and surface physics, as well as in catalysis and magnetism. LNLS has expanded its infra-structure as an open multidisciplinary research laboratory into complementary areas, such as electron and scanning probe microscopy, nanostructure synthesis and molecular biology. Many technological and scientific achievements have been attained in these last five years. Some of them will be highlighted here, with emphasis in the area of nanostructured and magnetic materials.

  16. Synchrotron X-Ray Microdiffraction Studies of Electromigration in Interconnect lines at the Advanced Light Source

    SciTech Connect

    Tamura, Nobumichi; Chen, Kai; Kunz, Martin

    2009-05-01

    Synchrotron polychromatic X-ray microdiffraction is a particularly suitable technique to study in situ the effect of electromigration in metal interconnects as add spatial resolution to grain orientation and strain sensitivity. This technique has been extensively used at the Advanced Light Source to monitor changes in aluminum and copper interconnect test structures while high-density current is passed into them during accelerated tests at elevated temperature. One of the principal findings is the observation of electromigration-induced plasticity in the metal lines that appear during the very early stages of electromigration. In some of the lines, high density of geometrically necessary dislocation are formed leading to additional diffusion paths causing an enhancement of electromigration effect at test temperature. This paper presents an overview of the principal results obtained from X-ray microdiffraction studies of electromigration effects on aluminum and copper interconnects at the ALS throughout continuous efforts that spanned over a decade (1998-2008) from approximately 40 weeks of combined beamtime.

  17. Synchrotron radiation in biosciences

    NASA Astrophysics Data System (ADS)

    Marinkovic, Nebojsa S.; Gupta, Sayan; Zhan, Chenyang; Chance, Mark R.

    2005-12-01

    The Center for Synchrotron Biosciences (CSB) operates five beamlines at the National Synchrotron Light Source (NSLS). Infrared (IR) micro-spectroscopy, X-ray absorption spectroscopy, structural proteomics and macromolecular footprinting are among the major technologies available through the Center. IR micro-spectroscopy is used to examine protein-folding in the microsecond time regime, image bone, neurons, seeds and other biological tissues, as well as image samples of interest in the chemical and environmental sciences. Structural proteomics research of New York Structural Genomics Research Consortium (NYSGRC) is steadily increasing the number of solved protein structures, with a goal to solve 100-200 structures per year. To speed up the research, a high-throughput method called 'metallomics' was implemented for NYSGRC crystallographers to detect intrinsic anomalous scatterers using X-ray absorption spectroscopy. Hydroxyl radical mediated X-ray footprinting is capable of resolving folding events of RNA, at single base resolution on millisecond timescales using a synchrotron white beam. The high brightness of synchrotron source is essential for CSB projects as it permits the use of smaller sample sizes and/or concentration, and allows studies of more complicated biological systems than with conventional sources.

  18. A superconducting bending magnet system for a compact synchrotron light source

    SciTech Connect

    Green, M.A.; Garren, A.A.; Leung, E.M.; Madura, D.D.; Cline, D.B.; Kolonko, J.J.; Schachinger, L.C.

    1995-07-01

    High intensity, high energy X-rays for use in protein crystallography, nano-machining and medical applications, such as non invasive coronary angiography, can be produced by a 1.2 to 1.5 GeV electron storage ring compact light source with 6 to 8 tesla superconducting bending magnets. Because the bending magnets are to be superconducting, the storage ring energy can be over factor of two lower than a conventional storage ring that delivers same photon energy. The ring, which has superconducting bending magnets, is smaller in circumference and has the advantage of having fewer particles in the ring for a given x ray source intensity. The proposed storage ring is a separated function accelerator ring with six superconducting bending magnet units. Conventional quadruples and correction elements would be located between the bending magnets. Because the synchrotron radiation is generated in the bend, the superconducting bending magnets must have a warm vacuum chamber for the electron beam. Variations of a superferric magnet design have been studied for this application. This report presents a superferric H magnet design that can produce good quality magnetic field in a region that is 50 mm high by 100 mm wide. This modified superferric H magnet design has saturated iron poles but the magnetic flux is returned from one pole to the other through an unsaturated iron return path. The dipole magnet required for a compact storage ring must be physically short (380 mm long), and the field must fall off rapidly at the ends of the magnet. This report describes a preliminary design for a pair of 6.894 tesia, thirty degree bending magnets in a common vacuum vessel for use in a 1.5 GeV compact storage ring light source.

  19. Angle-resolved light scattering of individual rod-shaped bacteria based on Fourier transform light scattering

    PubMed Central

    Jo, YoungJu; Jung, JaeHwang; Lee, Jee Woong; Shin, Della; Park, HyunJoo; Nam, Ki Tae; Park, Ji-Ho; Park, YongKeun

    2014-01-01

    Two-dimensional angle-resolved light scattering maps of individual rod-shaped bacteria are measured at the single-cell level. Using quantitative phase imaging and Fourier transform light scattering techniques, the light scattering patterns of individual bacteria in four rod-shaped species (Bacillus subtilis, Lactobacillus casei, Synechococcus elongatus, and Escherichia coli) are measured with unprecedented sensitivity in a broad angular range from −70° to 70°. The measured light scattering patterns are analyzed along the two principal axes of rod-shaped bacteria in order to systematically investigate the species-specific characteristics of anisotropic light scattering. In addition, the cellular dry mass of individual bacteria is calculated and used to demonstrate that the cell-to-cell variations in light scattering within bacterial species is related to the cellular dry mass and growth. PMID:24867385

  20. Angle-resolved light scattering of individual rod-shaped bacteria based on Fourier transform light scattering

    NASA Astrophysics Data System (ADS)

    Jo, Youngju; Jung, Jaehwang; Lee, Jee Woong; Shin, Della; Park, Hyunjoo; Nam, Ki Tae; Park, Ji-Ho; Park, Yongkeun

    2014-05-01

    Two-dimensional angle-resolved light scattering maps of individual rod-shaped bacteria are measured at the single-cell level. Using quantitative phase imaging and Fourier transform light scattering techniques, the light scattering patterns of individual bacteria in four rod-shaped species (Bacillus subtilis, Lactobacillus casei, Synechococcus elongatus, and Escherichia coli) are measured with unprecedented sensitivity in a broad angular range from -70° to 70°. The measured light scattering patterns are analyzed along the two principal axes of rod-shaped bacteria in order to systematically investigate the species-specific characteristics of anisotropic light scattering. In addition, the cellular dry mass of individual bacteria is calculated and used to demonstrate that the cell-to-cell variations in light scattering within bacterial species is related to the cellular dry mass and growth.

  1. XUV synchrotron optical components for the Advanced Light Source: Summary of the requirements and the developmental program

    SciTech Connect

    McKinney, W.; Irick, S.; Lunt, D.

    1992-07-01

    We give a brief summary of the requirements for water cooled optical components for the Advanced Light Source (ALS), a third generation synchrotron radiation source under construction at Lawrence Berkeley Laboratory (LBL). Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from a finished water cooled copper alloy mirror will be used to demonstrate the state of the art in optical metrology with the Takacs Long Trace Profiler (LTP II).

  2. Observation of light diffraction by time-resolved femtosecond correlation interferometry.

    PubMed

    Zeylikovich, I; Bai, G; Alfano, R R

    1995-07-15

    We demonstrate time development of the diffraction of light waves from objects for what is to our knowledge the f irst time by using a new femtosecond correlation interferometry. This new dynamical optics method allows for the conversion of temporal information to space information with femtosecond resolution and has the potential to produce a time-resolved femtosecond movie for the visualization of light-wave propagation in space for scientific, biological, and medical applications. PMID:19862089

  3. Depth resolved hyperspectral imaging spectrometer based on structured light illumination and Fourier transform interferometry.

    PubMed

    Choi, Heejin; Wadduwage, Dushan; Matsudaira, Paul T; So, Peter T C

    2014-10-01

    A depth resolved hyperspectral imaging spectrometer can provide depth resolved imaging both in the spatial and the spectral domain. Images acquired through a standard imaging Fourier transform spectrometer do not have the depth-resolution. By post processing the spectral cubes (x, y, λ) obtained through a Sagnac interferometer under uniform illumination and structured illumination, spectrally resolved images with depth resolution can be recovered using structured light illumination algorithms such as the HiLo method. The proposed scheme is validated with in vitro specimens including fluorescent solution and fluorescent beads with known spectra. The system is further demonstrated in quantifying spectra from 3D resolved features in biological specimens. The system has demonstrated depth resolution of 1.8 μm and spectral resolution of 7 nm respectively. PMID:25360367

  4. Depth resolved hyperspectral imaging spectrometer based on structured light illumination and Fourier transform interferometry

    PubMed Central

    Choi, Heejin; Wadduwage, Dushan; Matsudaira, Paul T.; So, Peter T.C.

    2014-01-01

    A depth resolved hyperspectral imaging spectrometer can provide depth resolved imaging both in the spatial and the spectral domain. Images acquired through a standard imaging Fourier transform spectrometer do not have the depth-resolution. By post processing the spectral cubes (x, y, λ) obtained through a Sagnac interferometer under uniform illumination and structured illumination, spectrally resolved images with depth resolution can be recovered using structured light illumination algorithms such as the HiLo method. The proposed scheme is validated with in vitro specimens including fluorescent solution and fluorescent beads with known spectra. The system is further demonstrated in quantifying spectra from 3D resolved features in biological specimens. The system has demonstrated depth resolution of 1.8 μm and spectral resolution of 7 nm respectively. PMID:25360367

  5. Angular and spectrally resolved investigations of yeast cells by light scattering microscopy and goniometric measurements

    NASA Astrophysics Data System (ADS)

    Stark, Julian; Müller, Dennis; Nothelfer, Steffen; Kienle, Alwin

    2015-07-01

    Spectrally and angular resolved light scattering from yeast cells was studied with a scattering microscope and a goniometer. Different cell models were investigated with help of analytical solutions of Maxwell's equations. It was found that extraction of precise morphological and optical cellular properties from the measured scattering patterns and phase functions requires more sophisticated cell models than standard Mie theory.

  6. Quaternary structure of K[ssubscript ATP] channel SUR2A nucleotide binding domains resolved by synchrotron radiation X-ray scattering

    SciTech Connect

    Park, Sungjo; Terzic, Andre

    2010-05-25

    Heterodimeric nucleotide binding domains NBD1/NBD2 distinguish the ATP-binding cassette protein SUR2A, a recognized regulatory subunit of cardiac ATP-sensitive K{sup +} (K{sub ATP}) channels. The tandem function of these core domains ensures metabolism-dependent gating of the Kir6.2 channel pore, yet their structural arrangement has not been resolved. Here, purified monodisperse and interference-free recombinant particles were subjected to synchrotron radiation small-angle X-ray scattering (SAXS) in solution. Intensity function analysis of SAXS profiles resolved NBD1 and NBD2 as octamers. Implemented by ab initio simulated annealing, shape determination prioritized an oblong envelope wrapping NBD1 and NBD2 with respective dimensions of 168 x 80 x 37 {angstrom}{sup 3} and 175 x 81 x 37 {angstrom}{sup 3} based on symmetry constraints, validated by atomic force microscopy. Docking crystal structure homology models against SAXS data reconstructed the NBD ensemble surrounding an inner cleft suitable for Kir6.2 insertion. Human heart disease-associated mutations introduced in silico verified the criticality of the mapped protein-protein interface. The resolved quaternary structure delineates thereby a macromolecular arrangement of K{sub ATP} channel SUR2A regulatory domains.

  7. NSLS 2007 Activity Report (National Synchrotron Light Source Activity Report 2007)

    SciTech Connect

    Miller ,L.; Nasta, K.

    2008-05-01

    The National Synchrotron Light Source is one of the world's most productive and cost-effective user facilities. With 2,219 individual users, about 100 more than last year, and a record-high 985 publications, 2007 was no exception. In addition to producing an impressive array of science highlights, which are included in this Activity Report, many NSLS users were honored this year for their scientific accomplishments. Throughout the year, there were major strides in the development of the scientific programs by strengthening strategic partnerships with major research resources and with the Center for Functional Nanomaterials (CFN). Of particular note, the Consortium for Materials Properties Research in Earth Sciences (COMPRES) received renewed funding for the next five years through the National Science Foundation. COMPRES operates four high-pressure NSLS beamlines--X17B2, X17B3, X17C, and U2A--and serves the earth science community as well as the rapidly expanding segment of researchers using high-pressure techniques in materials, chemical, and energy-related sciences. A joint appointment was made between the NSLS and Stony Brook University to further enhance interactions with COMPRES. There was major progress on two key beamline projects outlined in the Five-Year Strategic Plan: the X25 beamline upgrade and the construction of the X9 small angle scattering (SAXS) beamline. The X25 overhaul, which began with the installation of the in-vacuum mini-gap undulator (MGU) in January 2006, is now complete. X25 is once again the brightest beamline for macromolecular crystallography at the NSLS, and in tandem with the X29 undulator beamline, it will keep the NSLS at the cutting edge in this important area of research. Upgrade work associated with the new MGU and the front end for the X9 SAXS beamline--jointly developed by the NSLS and the CFN--also was completed. Beamline X9 will host the SAXS program that currently exists at beamline X21 and will provide new microbeam SAXS

  8. Spatially resolved synchrotron-induced X-ray fluorescence analyses of metal point drawings and their mysterious inscriptions

    NASA Astrophysics Data System (ADS)

    Reiche, Ina; Radtke, Martin; Berger, Achim; Görner, Wolf; Ketelsen, Thomas; Merchel, Silke; Riederer, Josef; Riesemeier, Heinrich; Roth, Michael

    2004-10-01

    Synchrotron-induced X-ray fluorescence (Sy-XRF) analysis was used to study the chemical composition of precious Renaissance silverpoint drawings. Drawings by famous artists such as Albrecht Dürer (1471-1528) and Jan van Eyck (approximately 1395-1441) must be investigated non-destructively. Moreover, extremely sensitive synchrotron- or accelerator-based techniques are needed since only small quantities of silver are deposited on the paper. New criteria for attributing these works to a particular artist could be established based on the analysis of the chemical composition of the metal points used. We illustrate how analysis can give new art historical information by means of two case studies. Two particular drawings, one of Albrecht Dürer, showing a profile portrait of his closest friend, "Willibald Pirckheimer" (1503), and a second one attributed to Jan van Eyck, showing a "Portrait of an elderly man", often named "Niccolò Albergati", are the object of intense art historical controversy. Both drawings show inscriptions next to the figures. Analyses by Sy-XRF could reveal the same kind of silverpoint for the Pirckheimer portrait and its mysterious Greek inscription, contrary to the drawing by Van Eyck where at least three different metal points were applied. Two different types of silver marks were found in this portrait. Silver containing gold marks were detected in the inscriptions and over-subscriptions. This is the first evidence of the use of gold points for metal point drawings in the Middle Ages.

  9. Time-resolved pump-probe photoelectron spectroscopy of helium using a mode-locked laser synchronized with synchrotron radiation pulses

    NASA Astrophysics Data System (ADS)

    Lacoursière, Jean; Meyer, Michael; Nahon, Laurent; Morin, Paul; Larzillière, Michel

    1994-12-01

    We report a new experimental setup consisting in the synchronization of 74.9094 MHz pulses from a mode-locked Ar + laser with 8.32 MHz pulses of vacuum ultraviolet (VUV) synchrotron radiation from the Super-ACO storage ring of the Laboratoire pour l'Utilisation du Rayonnement Electromagnétique (LURE). The capabilities of the setup are demonstrated in a time-resolved pump-probe (VUV + visible) experiment in which free helium atoms are resonantly ionized via the short-lived 1s3p ( 1P) state. This experiment allowed us to obtain the value of 1.12 ns for the temporal resolution (FWHM) of the experimental setup and to show the relevance of this technique for the investigation of nanosecond dynamics on gas phase species.

  10. Light adaptation of the unicellular red alga, Cyanidioschyzon merolae, probed by time-resolved fluorescence spectroscopy.

    PubMed

    Ueno, Yoshifumi; Aikawa, Shimpei; Kondo, Akihiko; Akimoto, Seiji

    2015-08-01

    Photosynthetic organisms change the quantity and/or quality of their pigment-protein complexes and the interactions among these complexes in response to light conditions. In the present study, we analyzed light adaptation of the unicellular red alga Cyanidioschyzon merolae, whose pigment composition is similar to that of cyanobacteria because its phycobilisomes (PBS) lack phycoerythrin. C. merolae were grown under different light qualities, and their responses were measured by steady-state absorption, steady-state fluorescence, and picosecond time-resolved fluorescence spectroscopies. Cells were cultivated under four monochromatic light-emitting diodes (blue, green, yellow, and red), and changes in pigment composition and energy transfer were observed. Cells grown under blue and green light increased their relative phycocyanin levels compared with cells cultured under white light. Energy-transfer processes to photosystem I (PSI) were sensitive to yellow and red light. The contribution of direct energy transfer from PBS to PSI increased only under yellow light, while red light induced a reduction in energy transfer from photosystem II to PSI and an increase in energy transfer from light-harvesting chlorophyll protein complex I to PSI. Differences in pigment composition, growth, and energy transfer under different light qualities are discussed. PMID:25577254

  11. Resolving the electromagnetic mechanism of surface-enhanced light scattering at single hot spots

    PubMed Central

    Alonso-González, P.; Albella, P.; Schnell, M.; Chen, J.; Huth, F.; García-Etxarri, A.; Casanova, F.; Golmar, F.; Arzubiaga, L.; Hueso, L.E.; Aizpurua, J.; Hillenbrand, R.

    2012-01-01

    Light scattering at nanoparticles and molecules can be dramatically enhanced in the 'hot spots' of optical antennas, where the incident light is highly concentrated. Although this effect is widely applied in surface-enhanced optical sensing, spectroscopy and microscopy, the underlying electromagnetic mechanism of the signal enhancement is challenging to trace experimentally. Here we study elastically scattered light from an individual object located in the well-defined hot spot of single antennas, as a new approach to resolve the role of the antenna in the scattering process. We provide experimental evidence that the intensity elastically scattered off the object scales with the fourth power of the local field enhancement provided by the antenna, and that the underlying electromagnetic mechanism is identical to the one commonly accepted in surface-enhanced Raman scattering. We also measure the phase shift of the scattered light, which provides a novel and unambiguous fingerprint of surface-enhanced light scattering. PMID:22353715

  12. Characterization of the Microchemical Structure of Seed Endosperm within a Cellular Dimension among Six Barley Varieties with Distinct Degradation Kinetics, Using Ultraspatially Resolved Synchrotron-Based Infrared Synchrotron-Based Infrared

    SciTech Connect

    Liu, N.; Yu, P

    2010-01-01

    information and the nutrient value of barley grain, although significant differences in biodegradation kinetics were observed. In conclusion, the studies demonstrated the potential of ultraspatially resolved synchrotron based technology (SFTIRM) to reveal the structural and chemical makeup within cellular and subcellular dimensions without destruction of the inherent structure of cereal grain tissue.

  13. Characterization of high energy Xe ion irradiation effects in single crystal molybdenum with depth-resolved synchrotron microbeam diffraction

    NASA Astrophysics Data System (ADS)

    Yun, Di; Miao, Yinbin; Xu, Ruqing; Mei, Zhigang; Mo, Kun; Mohamed, Walid; Ye, Bei; Pellin, Michael J.; Yacout, Abdellatif M.

    2016-04-01

    Microbeam X-ray diffraction experiments were conducted at beam line 34-ID of the Advanced Photon Source (APS) on fission fragment energy Xe heavy ion irradiated single crystal Molybdenum (Mo). Lattice strain measurements were obtained with a depth resolution of 0.7 μm, which is critical in resolving the peculiar heterogeneity of irradiation damage associated with heavy ion irradiation. Q-space diffraction peak shift measurements were correlated with lattice strain induced by the ion irradiations. Transmission electron microscopy (TEM) characterizations were performed on the as-irradiated materials as well. Nanometer sized Xe bubble microstructures were observed via TEM. Molecular Dynamics (MD) simulations were performed to help interpret the lattice strain measurement results from the experiment. This study showed that the irradiation effects by fission fragment energy Xe ion irradiations can be collaboratively understood with the depth resolved X-ray diffraction and TEM measurements under the assistance of MD simulations.

  14. High-power, narrow-band, high-repetition-rate, 5.9 eV coherent light source using passive optical cavity for laser-based angle-resolved photoelectron spectroscopy.

    PubMed

    Omachi, J; Yoshioka, K; Kuwata-Gonokami, M

    2012-10-01

    We demonstrate a scheme for efficient generation of a 5.9 eV coherent light source with an average power of 23 mW, 0.34 meV linewidth, and 73 MHz repetition rate from a Ti: sapphire picosecond mode-locked laser with an output power of 1 W. Second-harmonic light is generated in a passive optical cavity by a BiB(3)O(6) crystal with a conversion efficiency as high as 67%. By focusing the second-harmonic light transmitted from the cavity into a β-BaB(2)O(4) crystal, we obtain fourth-harmonic light at 5.9 eV. This light source offers stable operation for at least a week. We discuss the suitability of the laser light source for high-resolution angle-resolved photoelectron spectroscopy by comparing it with other sources (synchrotron radiation facilities and gas discharge lamp). PMID:23188317

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

    SciTech Connect

    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.

  16. Bringing Physics, Synchrotron Light and Probing Neutrons to the Public: A Collaborative Outreach

    ERIC Educational Resources Information Center

    Micklavzina, Stanley; Almqvist, Monica; Sörensen, Stacey L.

    2014-01-01

    Stanley Micklavzina, a US physics educator on sabbatical, teams up with a Swedish national research laboratory, a synchrotron radiation experimental group and a university science centre to develop and create educational and public outreach projects. Descriptions of the physics, science centre displays and public demonstrations covering the…

  17. Support for the Advanced Polymers Beamline at the National Synchrotron Light Source

    SciTech Connect

    Hsiao, Benjamin S

    2008-10-01

    The primary focus of the X27C beamline is to investigate frontier polymer science and engineering problems with emphasis on real-time studies of structures, morphologies and dynamics from atomic, nanoscopic, microscopic to mesoscopic scales using simultaneous small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) techniques. The scientific merit of this project is as follows. Currently, many unique sample chambers for in-situ synchrotron studies, developed by the PI (B. Hsiao) and Co-PI (B. Chu), are available for general users of X27C at NSLS. These instruments include a gel/melt spinning apparatus, a continuous fiber drawing apparatus, a tensile stretching apparatus, a high pressure X-ray cell using supercritical carbon dioxide, a parallel plate strain-controlled shear stage and a dynamic rheometer for small-strain oscillatory deformation study. Based on the use of these instruments in combination with synchrotron X-rays, many new insights into the relationships between processing and structure have been obtained in recent years. The broader impact of this project is as follows. The X27C beamline is the first synchrotron facility in the United States dedicated to chemistry/materials research (with emphasis on polymers). The major benefit of this facility to the materials community is that no extensive synchrotron experience and equipment preparation are required from general users to carry out cutting-edge experiments.

  18. NSLS 2005 ACTIVITY REPORT (NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 2005).

    SciTech Connect

    MILLER, L.

    2006-05-01

    efforts on NSLS-II, the world-leading third-generation synchrotron planned for construction at BNL. NSLS-II passed a critical milestone in 2005 with the approval by the Department of Energy of CD-0. BNL has established the NSLS-II Project Organization within the Light Sources Directorate to put in place the management systems and infrastructure necessary to execute this complex undertaking. I will serve as NSLS-II Project Director and also retain my position as Associate Laboratory Director for Light Sources, with the NSLS reporting to me. Another exciting development is the planned establishment of the Joint Photon Sciences Institute (JPSI). JPSI will be devoted to cultivating and fostering collaborative, interdisciplinary R&D in areas of the physical sciences, engineering, and the life sciences that are united in employing synchrotron-based methods. JPSI will also develop new methods and applications that exploit the unique capabilities of NSLS-II and will serve as a gateway for NSLS-II users. JPSI will be a partnership between the Department of Energy and New York State, and I am delighted that New York State Governor George Pataki has pledged $30 million for the construction of the JPSI building. The building will be located adjacent to NSLS-II and will contain offices, meeting rooms, and specialized laboratories. The operating expenses of JPSI and funding for its research programs will be provided by the federal government. Until a permanent NSLS Director is selected, NSLS User Science Division Associate Chair Chi-Chang Kao will serve as the Interim NSLS Director. I couldn't be leaving the facility in more capable hands. Chi-Chang will lead NSLS staff and users this year in the development of a five-year strategic plan for the NSLS, scheduled for completion by the end of summer 2006. The plan will outline the course for the future operation and development of the NSLS, and will help ensure that the future of the NSLS remains as bright as its past.

  19. Diffraction-Enhanced Computed Tomographic Imaging of Growing Piglet Joints by Using a Synchrotron Light Source

    PubMed Central

    Rhoades, Glendon W; Belev, George S; Chapman, L Dean; Wiebe, Sheldon P; Cooper, David M; Wong, Adelaine TF; Rosenberg, Alan M

    2015-01-01

    The objective of this project was to develop and test a new technology for imaging growing joints by means of diffraction-enhanced imaging (DEI) combined with CT and using a synchrotron radiation source. DEI–CT images of an explanted 4-wk-old piglet stifle joint were acquired by using a 40-keV beam. The series of scanned slices was later ‘stitched’ together, forming a 3D dataset. High-resolution DEI-CT images demonstrated fine detail within all joint structures and tissues. Striking detail of vasculature traversing between bone and cartilage, a characteristic of growing but not mature joints, was demonstrated. This report documents for the first time that DEI combined with CT and a synchrotron radiation source can generate more detailed images of intact, growing joints than can currently available conventional imaging modalities. PMID:26310464

  20. ZAP AND ITS APPLICATION TO THE OPTIMIZATION OF SYNCHROTRON LIGHT SOURCE PARAMETERS

    SciTech Connect

    Zisman, M.S.

    1987-10-01

    A new computer code, ZAP, has been written to study the influence of various collective effects on the performance of electron storage rings. In particular, the code can evaluate the equilibrium emittance of a ring including the effects of intrabeam scattering. Examples are presented of utilizing the code to optimize the design of storage rings for the purposes of a third-generation synchrotron radiation source and a high-gain free-electron laser. In addition, the importance of the intrabeam scattering emittance blowup to the issue of low energy injection is discussed. Such considerations will be necessary to optimize the design of compact synchrotrons now being studied for use in x-ray lithography. To verify predictions of the code, comparisons are made with experimental measurements of low energy beam emittance taken from the Aladdin storage ring; reasonable agreement is obtained.

  1. THE WISE LIGHT CURVES OF Z CAMELOPARDALIS DURING OUTBURST: EVIDENCE FOR SYNCHROTRON EMISSION?

    SciTech Connect

    Harrison, Thomas E.

    2014-08-10

    The WISE mission happened to observe the cataclysmic variable Z Cam at the peak of an outburst. The WISE single exposure data shows that Z Cam was highly variable at 12 μm, but only marginally so at shorter wavelengths. The rapid variability at 12 μm, and the fact that these observations occurred close to visual maximum suggests that, like SS Cyg, Z Cam is a synchrotron source.

  2. Resolving the Extragalactic Background Light with Multi-field Deep ALMA Data

    NASA Astrophysics Data System (ADS)

    Fujimoto, S.; Ouchi, M.; Ono, Y.; Shibuya, T.; Ishigaki, M.; Momose, R.

    2015-12-01

    We explore the origin of the faint submilimeter (submm) - mm emission (< 0.1 mJy) which is thought to contribute the previously un-resolved 50% of the extra-galactic background light (EBL) around mm by making full use of our latest ALMA cycle 2 and archival cycle 0-1 multi-field deep data. With > 100 pointings in Band 6 and 7, which is largest to date, we identify 87 faint ALMA sources down to ˜ 0.01 mJy (SFRIR˜ 5M⊙ yr-1). Combining the bright source studies in literatures, we derive reliable 1.2 mm number counts in the wide range of flux density, 0.01 - 10.0 mJy, which enables us to almost fully (75 - 145%) resolve the EBL.

  3. Moisture-insensitive optical fingerprint scanner based on polarization resolved in-finger scattered light.

    PubMed

    Back, Seon-Woo; Lee, Yong-Geon; Lee, Sang-Shin; Son, Geun-Sik

    2016-08-22

    A moisture-insensitive optical fingerprint scanner (FPS) that is based on polarization resolved in-finger light is proposed and realized. Incident visible light, which is selectively fed to a fingerprint sample via a polarization beam splitter (PBS), is deemed to be partially scattered backward by tissues associated with the skin of the finger. The backscattered light is mostly index-guided in the ridge comprising the fingerprint, which has a higher refractive index, and is drastically dispersed in the valley, which is typically filled with water or air and so has a lower index. However, when light reflects directly off the surface of the finger skin, it fundamentally prevents the scanned image from being determined. The proposed FPS produces bright and dark intensity patterns that are alternately created on the surface of the PBS and correspond to the ridges and valleys, respectively. Thus, this method can especially distinguish between a fake synthetic fingerprint and a genuine fingerprint due to its use of in-finger scattered light. The scanner has been rigorously designed by carrying out ray-optic simulations depending on the wavelength, with tissue-induced scattering taken into account. The device was constructed by incorporating a wire-grid type PBS in conjunction with visible LED sources, including blue, green and red. The scanner adopting a blue LED, which exhibits the strongest light scattering, resulted in the best fingerprint image, enabling enhanced fidelity under the wet and dry situations. Finally, a fake synthetic fingerprint could be successfully discriminated. PMID:27557199

  4. Water-induced morphology changes in BaO/γ-Al2O3 NOx storage materials: an FTIR, TPD, and time-resolved synchrotron XRD study

    SciTech Connect

    Szanyi, Janos; Kwak, Ja Hun; Kim, Do Heui; Wang, Xianqin; Chimentao, Ricardo J.; Hanson, Jonathan; Epling, William S.; Peden, Charles HF

    2007-03-29

    The effect of water on the morphology of BaO/Al2O3-based NOx storage materials was investigated using Fourier transform infrared spectroscopy, temperature programmed desorption, and time-resolved synchrotron X-ray diffraction techniques. The results of this multi-spectroscopy study reveal that, in the presence of water, surface Ba-nitrates convert to bulk nitrates, and water facilitates the formation of large Ba(NO3)2 particles. This process is completely reversible, i.e. after the removal of water from the storage material a significant fraction of the bulk nitrates re-convert to surface nitrates. NO2 exposure of a H2O-containing (wet) BaO/Al2O3 sample results in the formation of nitrites and bulk nitrates exclusively, i.e. no surface nitrates form. After further exposure to NO2, the nitrites completely convert to bulk nitrates. The amount of NOx taken up by the storage material is, however, essentially unaffected by the presence of water, regardless of whether the water was dosed prior to or after NO2 exposure. Based on the results of this study we are now able to explain most of the observations reported in the literature on the effect of water on NOx uptake on similar storage materials.

  5. Water-Induced Morphology Changes in BaO/gamma-Al2O3 NOx Storage Materials: an FTIR, TPD, and Time-Resolved Synchrotron XRD Study

    SciTech Connect

    Szanyi,J.; Kwak, J.; Kim, D.; Wang, X.; Chimentao, R.; Hanson, J.; Epling, W.; Peden, C.

    2007-01-01

    The effect of water on the morphology of BaO/Al{sub 2}O{sub 3}-based NO{sub x} storage materials was investigated using Fourier transform infrared spectroscopy, temperature programmed desorption, and time-resolved synchrotron X-ray diffraction techniques. The results of this multispectroscopy study reveal that in the presence of water surface Ba-nitrates convert to bulk nitrates and water facilitates the formation of large Ba(NO{sub 3}){sub 2} particles. The conversion of surface to bulk Ba-nitrates is completely reversible (i.e., after the removal of water from the storage material a significant fraction of the bulk nitrates reconverts to surface nitrates). NO{sub 2} exposure of a H{sub 2}O-containing (wet) BaO/Al{sub 2}O{sub 3} sample results in the formation of nitrites and bulk nitrates exclusively (i.e., no surface nitrates form). After further exposure to NO{sub 2}, the nitrites completely convert to bulk nitrates. The amount of NO{sub x} taken up by the storage material, however, is essentially unaffected by the presence of water regardless of whether the water was dosed prior to or after NO{sub 2} exposure. On the basis of the results of this study, we are now able to explain most of the observations reported in the literature on the effect of water on NO{sub x} uptake on similar storage materials.

  6. Angle-Resolved Second-Harmonic Light Scattering from Colloidal Particles

    SciTech Connect

    Yang, N.; Angerer, W. E.; Yodh, A. G.

    2001-09-03

    We report angle-resolved second-harmonic generation (SHG) measurements from suspensions of centrosymmetric micron-size polystyrene spheres with surface-adsorbed dye (malachite green). The second-harmonic scattering profiles differ qualitatively from linear light scattering profiles of the same particles. We investigated these radiation patterns using several polarization configurations and particle diameters. We introduce a simple Rayleigh-Gans-Debye model to account for the SHG scattering anisotropy. The model compares favorably with our experimental data. Our measurements suggest scattering anisotropy may be used to isolate particle nonlinear optics from other bulk nonlinear optical effects in suspension.

  7. An electro-optic modulator-assisted wavevector-resolving Brillouin light scattering setup.

    PubMed

    Neumann, T; Schneider, T; Serga, A A; Hillebrands, B

    2009-05-01

    Brillouin light scattering spectroscopy is a powerful technique which incorporates several extensions such as space-, time-, phase-, and wavevector-resolution. Here, we report on the improvement of the wavevector-resolving setup by including an electro-optic modulator. This provides a reference to calibrate the position of the diaphragm hole which is used for wavevector selection. The accuracy of this calibration is only limited by the accuracy of the wavevector measurement itself. To demonstrate the validity of the approach the wavevectors of dipole-dominated spin waves excited by a microstrip antenna were measured. PMID:19485518

  8. Atlas of Light Curves and Photometric Monitoring of The Non-Resolved Space Objects

    NASA Astrophysics Data System (ADS)

    Koshkin, N.; Shakun, L.; Korobeinikova, E.; Strakhova, S.; Melikiants, S.; Dragomiretsky, V.; Ryabov, A.

    2013-09-01

    Photometric monitoring is a tool for remote diagnostics of the satellite rotation around its center of mass. This information is important in many cases. For example, in case of abnormal mode of the satellite functioning. And also to take into account the orientation of non-spherical body (eg, space debris) in the numerical integration of its motion when it is expected to close approach with the another spacecraft. This paper presents the results of long-term (since 1980) photometric monitoring of both operational satellites, and large bodies of space debris in low-Earth orbit (LEO). The light curves of the non-resolved cosmic objects (CO), which are recorded prior to 2004, were obtained using electrophotometer (PMT with multialkaline cathode) in the visible wavelength range without using a filter. The light curves, which are recorded after 2004, were obtained using a TV CCD-camera also without the use of filters. For tracking low-orbit satellites was used telescope KT-50 on alt-azimuth mounting, which allows one to tracking the objects moving at a high angular velocity. The diameter of main mirror is 0.5 m, focal length is 3 m. For any ?O is given his international (COSPAR) number and NORAD catalog number, and provides information about its form and initial orbital elements. The brightness of satellite presented in magnitudes. He reduced with considering the atmosphere's light extinction and is related to a distance of 1000 km. For each passage and light curve is pointed the date and UTC. The light curves of stabilized CO have only small light variations and they show the dependence from the phase angle. Rotating CO have periodic light curves. The type (kind) and the periods of the light curves change with the time.

  9. Study for a proposed Phase I Energy Recovery Linac (ERL) Synchrotron Light Source at Cornell University

    SciTech Connect

    Sol M. Gruner and Maury Tigner, eds.; Ivan Bazarov; Sergey Belomestnykh; Don Bilderback; Ken Finkelstein; Ernie Fontes; Steve Gray; Sol M. Gruner; Geoff Krafft; Lia Merminga; Hasan Padamsee; Ray Helmke; Qun Shen; Joe Rogers; Charles Sinclair; Richard Talman; Maury Tigner

    2001-07-01

    Synchrotron radiation (SR) has become an essential and rapidly growing tool across the sciences and engineering. World-wide, about 70 SR sources are in various stages of operation, construction, or planning, representing a cumulative investment on many billions of dollars and serving a growing research community well in excess of 10,000 scientists. To date, all major SR x-ray facilities are based on electron (or positron) storage rings. Given the expected continued growth, importance and expense of SR sources, it is important to ask if there are alternatives to the storage ring SR source which offer advantages of capability or cost. A step in this direction is being taken by the SR community with the proposed developments of linac-based x-ray free-electron lasers (XFELs) utilizing the self-amplified spontaneous emission process (SASE). However, the versatility of modern developments in accelerator physics, as applied to synchrotron radiation, is not limited to storage rings or XFELs. New developments in laser driven photoinjectors and superconducting linac technology open new and exciting possibilities for novel SR-generating machines which offer extraordinary capabilities and promise to catalyze whole new areas of SR-based science.

  10. Functional micro-imaging of soft and hard tissue using synchrotron light

    NASA Astrophysics Data System (ADS)

    Thurner, Philipp J.; Wyss, Peter; Voide, Romain; Stauber, Martin; Muller, Bert; Stampanoni, Marco; Hubbell, Jeffrey A.; Muller, Ralph; Sennhauser, Urs

    2004-10-01

    In current biological and biomedical research, quantitative endpoints have become an important factor of success. Classically, such endpoints were investigated with 2D imaging, which is usually destructive and the 3D character of tissue gets lost. 3D imaging has gained in importance as a tool for both, qualitative and quantitative assessment of biological systems. In this context synchrotron radiation based tomography has become a very effective tool for opaque 3D tissue systems. Cell cultures and adherent scaffolds are visualized in 3D in a hydrated environment, even uncovering the shape of individual cells. Advanced morphometry allows to characterize the differences between the cell cultures of two distinct phenotypes. Moreover, a new device is presented enabling the 3D investigation of trabecular bone under mechanical load in a time-lapsed fashion. Using the highly brilliant X-rays from a synchrotron radiation source, bone microcracks and an indication for un-cracked ligament bridging are uncovered. 3D microcrack analysis proves that the classification of microcracks from 2D images is ambiguous. Fatigued bone was found to fail in burst-like fashion, whereas non-fatigued bone exhibited a distinct failure band. Additionally, a higher increase in microcrack volume was detected in fatigued in comparison to non-fatigued bone. The developed technologies prove to be very effective tools for advanced 3D imaging of both hard and soft tissue.

  11. Polymer research at synchrotron radiation sources: symposium proceedings

    SciTech Connect

    Russell, T.P.; Goland, A.N.

    1985-01-01

    The twenty-two papers are arranged into eleven sessions entitled: general overviews; time-resolved x-ray scattering; studies using fluorescence, ion-containing polymers; time-resolved x-ray scattering; novel applications of synchrotron radiation; phase transitions in polymers; x-ray diffraction on polymers; recent detector advances; complementary light, x-ray and neutron studies; and neutron scattering studies. Seven of the papers are processed separately; three of the remainder have been previously processed. (DLC)

  12. Procurement history of the hybrid undulator for the U-5 Beam Line at the National Synchrotron Light Source

    SciTech Connect

    James, D.C.; Bader, S.D.; Viccaro, P.J.

    1989-05-01

    As part of a national multi-institutional Materials Research Group (MRG), Argonne National Laboratory had the responsibility, under a prime contract with the U.S. Department of Energy, of obtaining a Permanent Magnet Hybrid undulator to be used on the U5 Beam Line on the VUV Ring at the National Synchrotron Light Source (NSLS). The procurement involved determining the technical specifications of the device as well as developing an effective procedure for evaluation of the proposals. The conceptual design of the magnetic structure including all pertinent magnetic field properties was developed before the actual procurement process was initiated. In addition, complete calculations of the expected spectral properties of the undulator were performed which included the emittance properties of the VUV ring. The results from both analysis were essential in determining the expected performance of the device and the final choice of operating parameters.

  13. Emphysema diagnosis using X-ray dark-field imaging at a laser-driven compact synchrotron light source

    PubMed Central

    Schleede, Simone; Meinel, Felix G.; Bech, Martin; Herzen, Julia; Achterhold, Klaus; Potdevin, Guillaume; Malecki, Andreas; Adam-Neumair, Silvia; Thieme, Sven F.; Bamberg, Fabian; Nikolaou, Konstantin; Bohla, Alexander; Yildirim, Ali Ö.; Loewen, Roderick; Gifford, Martin; Ruth, Ronald; Eickelberg, Oliver; Reiser, Maximilian; Pfeiffer, Franz

    2012-01-01

    In early stages of various pulmonary diseases, such as emphysema and fibrosis, the change in X-ray attenuation is not detectable with absorption-based radiography. To monitor the morphological changes that the alveoli network undergoes in the progression of these diseases, we propose using the dark-field signal, which is related to small-angle scattering in the sample. Combined with the absorption-based image, the dark-field signal enables better discrimination between healthy and emphysematous lung tissue in a mouse model. All measurements have been performed at 36 keV using a monochromatic laser-driven miniature synchrotron X-ray source (Compact Light Source). In this paper we present grating-based dark-field images of emphysematous vs. healthy lung tissue, where the strong dependence of the dark-field signal on mean alveolar size leads to improved diagnosis of emphysema in lung radiographs. PMID:23074250

  14. Operation of a general purpose stepping motor-encoder positioning subsystem at the National Synchrotron Light Source

    SciTech Connect

    Stubblefield, F.W.

    1985-11-01

    Four copies of a general purpose subsystem for mechanical positioning of detectors, samples, and beam line optical elements which constitute experiments at the National Synchrotron Light Source facility of Brookhaven National Laboratory have been constructed and placed into operation. Construction of a fifth subsystem unit is nearing completion. The subsystems affect mechanical positioning by controlling a set of stepping motor-encoder pairs. The units are general purpose in the sense that they receive commands over a 9600 baud asynchronous serial line compatible with the RS-232-C electrical signal standard, generate TTL-compatible streams of stepping pulses which can be used with a wide variety of stepping motors, and read back position values from a number of different types and models of position encoder. The basic structure of the motor controller subsystem is briefly reviewed. Additions to the subsystem made in response to problems indicated by actual operation of the four installed units are described in more detail.

  15. LPE grown LSO:Tb scintillator films for high-resolution X-ray imaging applications at synchrotron light sources

    NASA Astrophysics Data System (ADS)

    Cecilia, A.; Rack, A.; Douissard, P.-A.; Martin, T.; Dos Santos Rolo, T.; Vagovič, P.; Hamann, E.; van de Kamp, T.; Riedel, A.; Fiederle, M.; Baumbach, T.

    2011-08-01

    Within the project ScinTAX of the 6th framework program (FP6) of the European Commission (SCINTAX—STRP 033 427) we have developed a new thin single crystal scintillator for high-resolution X-ray imaging. The scintillator is based on a Tb-doped Lu2SiO5 (LSO) film epitaxially grown on an adapted substrate. The high density, effective atomic number and light yield of the scintillating LSO significantly improves the efficiency of the X-ray imaging detectors currently used in synchrotron micro-imaging applications. In this work we present the characterization of the scintillating LSO films in terms of their spatial resolution performance and we provide two examples of high spatial and high temporal resolution applications.

  16. National Synchrotron Light Source user`s manual: Guide to the VUV and x-ray beamlines. Fifth edition

    SciTech Connect

    Gmuer, N.F.

    1993-04-01

    The success of the National Synchrotron Light Source is based, in large part, on the size of the user community and the diversity of the scientific and technical disciplines represented by these users. As evidence of this success, the VUV Ring has just celebrated its 10th anniversary and the X-ray Ring will do the same in 1995. In order to enhance this success, the NSLS User`s Manual: Guide to the VUV and X-Ray Beamlines - Fifth Edition, is being published. This Manual presents to the scientific community-at-large the current and projected architecture, capabilities and research programs of the various VUV and X-ray beamlines. Also detailed is the research and computer equipment a General User can expect to find and use at each beamline when working at the NSLS. The Manual is updated periodically in order to keep pace with the constant changes on these beamlines.

  17. Emphysema diagnosis using X-ray dark-field imaging at a laser-driven compact synchrotron light source.

    PubMed

    Schleede, Simone; Meinel, Felix G; Bech, Martin; Herzen, Julia; Achterhold, Klaus; Potdevin, Guillaume; Malecki, Andreas; Adam-Neumair, Silvia; Thieme, Sven F; Bamberg, Fabian; Nikolaou, Konstantin; Bohla, Alexander; Yildirim, Ali Ö; Loewen, Roderick; Gifford, Martin; Ruth, Ronald; Eickelberg, Oliver; Reiser, Maximilian; Pfeiffer, Franz

    2012-10-30

    In early stages of various pulmonary diseases, such as emphysema and fibrosis, the change in X-ray attenuation is not detectable with absorption-based radiography. To monitor the morphological changes that the alveoli network undergoes in the progression of these diseases, we propose using the dark-field signal, which is related to small-angle scattering in the sample. Combined with the absorption-based image, the dark-field signal enables better discrimination between healthy and emphysematous lung tissue in a mouse model. All measurements have been performed at 36 keV using a monochromatic laser-driven miniature synchrotron X-ray source (Compact Light Source). In this paper we present grating-based dark-field images of emphysematous vs. healthy lung tissue, where the strong dependence of the dark-field signal on mean alveolar size leads to improved diagnosis of emphysema in lung radiographs. PMID:23074250

  18. Initial feasibility study of a dedicated synchrotron radiation light source for ultrafast X-ray science

    SciTech Connect

    Corlett, John N.; DeSantis, S.; Hartman, N.; Heimann, P.; LaFever, R.; Li, D.; Padmore, H.; Rimmer, R.; Robinson, K.; Schoenlein, R.; Tanabe, J.; Wang, S.; Zholents, A.; Kairan, D.

    2001-10-26

    We present an initial feasibility summary of a femtosecond synchrotron radiation x-ray source based on a flat-beam rf gun and a recirculating superconducting linac that provides beam to an array of undulators and bend magnets. Optical pulse durations of < 100 fs are obtained by a combination of electron pulse compression, transverse temporal correlation of the electrons, and x-ray pulse compression. After an introduction and initial scientific motivation, we cover the following aspects of the design: layout and lattice, ultra-fast x-ray pulse production, flat electron-beam production, the rf gun, rf systems, cryogenic systems, collective effects, photon production, and synchronization of x-ray and laser pulses. We conclude with a summary of issues and areas of development that remain to be addressed.

  19. Characterization of spatially resolved high resolution x-ray spectrometers for high energy density physics and light source experiments

    SciTech Connect

    Hill, K. W. Bitter, M.; Delgado-Aparacio, L.; Efthimion, P.; Pablant, N. A.; Lu, J.; Beiersdorfer, P.; Chen, H.; Magee, E.

    2014-11-15

    A high resolution 1D imaging x-ray spectrometer concept comprising a spherically bent crystal and a 2D pixelated detector is being optimized for diagnostics of small sources such as high energy density physics (HEDP) and synchrotron radiation or x-ray free electron laser experiments. This instrument is used on tokamak experiments for Doppler measurements of ion temperature and plasma flow velocity profiles. Laboratory measurements demonstrate a resolving power, E/ΔE of order 10 000 and spatial resolution better than 10 μm. Initial tests of the high resolution instrument on HEDP plasmas are being performed.

  20. Synchrotron-based X-ray absorption near-edge spectroscopy imaging for laterally resolved speciation of selenium in fresh roots and leaves of wheat and rice

    PubMed Central

    Wang, Peng; Menzies, Neal W.; Lombi, Enzo; McKenna, Brigid A.; James, Simon; Tang, Caixian; Kopittke, Peter M.

    2015-01-01

    Knowledge of the distribution of selenium (Se) species within plant tissues will assist in understanding the mechanisms of Se uptake and translocation, but in situ analysis of fresh and highly hydrated plant tissues is challenging. Using synchrotron-based fluorescence X-ray absorption near-edge spectroscopy (XANES) imaging to provide laterally resolved data, the speciation of Se in fresh roots and leaves of wheat (Triticum aestivum L.) and rice (Oryza sativa L.) supplied with 1 μM of either selenate or selenite was investigated. For plant roots exposed to selenate, the majority of the Se was efficiently converted to C-Se-C compounds (i.e. methylselenocysteine or selenomethionine) as selenate was transported radially through the root cylinder. Indeed, even in the rhizodermis which is exposed directly to the bulk solution, only 12–31% of the Se was present as uncomplexed selenate. The C-Se-C compounds were probably sequestered within the roots, whilst much of the remaining uncomplexed Se was translocated to the leaves—selenate accounting for 52–56% of the total Se in the leaves. In a similar manner, for plants exposed to selenite, the Se was efficiently converted to C-Se-C compounds within the roots, with only a small proportion of uncomplexed selenite observed within the outer root tissues. This resulted in a substantial decrease in translocation of Se from the roots to leaves of selenite-exposed plants. This study provides important information for understanding the mechanisms responsible for the uptake and subsequent transformation of Se in plants. PMID:26019258

  1. Investigation of oxygen vacancies in CeO2/Pt system with synchrotron light techniques

    NASA Astrophysics Data System (ADS)

    Braglia, L.; Bugaev, A. L.; Lomachenko, K. A.; Soldatov, A. V.; Lamberti, C.; Guda, A. A.

    2016-05-01

    A peculiar property of ceria is the ease to form oxygen vacancies, producing reactive sites or facilitating ionic diffusion. For these reasons ceria promotes catalytic activities for a number of important reactions when it is used as a support for transition metals. In our work we study the temporal evolution of oxygen vacancies formation by time-resolved XANES at Ce K- edge and XRD measurements on CeO2/Pt nanoparticles, successfully monitoring the reaction of CO oxidation.

  2. Considerations for the use of synchrotron radiation sources to measure sub-keV x-ray photoabsorption cross sections in transmission

    SciTech Connect

    Tirsell, K.G.; Del Grande, N.K.

    1988-02-01

    Sub-keV x-ray photoabsorption cross section measurements in transmission have been made using synchrotron radiation beam lines on the VUV storage ring at the National Synchrotron Light Source (NSLS) and on the SPEAR storage ring at Stanford. The experimental considerations associated with making absolute measurements are reviewed, along with techniques for resolving difficulties. Suggestions for future measurements are included.

  3. Angular resolved light scattering for discriminating among marine picoplankton: modeling and experimental measurements

    NASA Astrophysics Data System (ADS)

    Shao, Bing; Jaffe, Jules S.; Chachisvilis, Mirianas; Esener, Sadik C.

    2006-12-01

    In order to assess the capability to optically identify small marine microbes, both simulations and experiments of angular resolved light scattering (ARLS) were performed. After calibration with 30-nm vesicles characterized by a nearly constant scattering distribution for vertically polarized light (azimuthal angle=90°), ARLS from suspensions of three types of marine picoplankton (two prokaryotes and one eukaryote) in seawater was measured with a scattering device that consisted of an elliptical mirror, a rotating aperture, and a PMT. Scattered light was recorded with adequate signal-to-noise in the 40-140°. Simulations modeled the cells as prolate spheroids with independently measured dimensions. For the prokaryotes, approximated as homogeneous spheroids, simulations were performed using the RM (Rayleigh-Mie) - I method, a hybrid of the Rayleigh-Debye approximation and the generalized Lorentz-Mie theory. For the picoeukaryote, an extended RM - I method was developed for a coated spheroid with different shell thickness distributions. The picoeukaryote was then modeled as a coated sphere with a spherical core. Good overall agreements were obtained between simulations and experiments. The distinctive scattering patterns of the different species hold promise for an identification system based on ARLS.

  4. Nuclear waste viewed in a new light; a synchrotron study of uranium encapsulated in grout.

    PubMed

    Stitt, C A; Hart, M; Harker, N J; Hallam, K R; MacFarlane, J; Banos, A; Paraskevoulakos, C; Butcher, E; Padovani, C; Scott, T B

    2015-03-21

    How do you characterise the contents of a sealed nuclear waste package without breaking it open? This question is important when the contained corrosion products are potentially reactive with air and radioactive. Synchrotron X-rays have been used to perform micro-scale in-situ observation and characterisation of uranium encapsulated in grout; a simulation for a typical intermediate level waste storage packet. X-ray tomography and X-ray powder diffraction generated both qualitative and quantitative data from a grout-encapsulated uranium sample before, and after, deliberately constrained H2 corrosion. Tomographic reconstructions provided a means of assessing the extent, rates and character of the corrosion reactions by comparing the relative densities between the materials and the volume of reaction products. The oxidation of uranium in grout was found to follow the anoxic U+H2O oxidation regime, and the pore network within the grout was observed to influence the growth of uranium hydride sites across the metal surface. Powder diffraction analysis identified the corrosion products as UO2 and UH3, and permitted measurement of corrosion-induced strain. Together, X-ray tomography and diffraction provide means of accurately determining the types and extent of uranium corrosion occurring, thereby offering a future tool for isolating and studying the reactions occurring in real full-scale waste package systems. PMID:25497037

  5. Developing EnviroSuite Resources at the National Synchrotron Light Source

    SciTech Connect

    Paul Northrup; Jeffrey Fitts; Mark Fuhrmann; Paul Kalb

    2006-06-01

    The objective of Brookhaven National Laboratory's EnviroSuite Initiative is to develop the facilities, user support infrastructure, and techniques necessary to conduct world-class molecular environmental science research at the NSLS. This is intended to benefit the research of ERSD-supported scientists, both through direct access and assistance and through the indirect benefits of a broader network of environmental scientists as collaborators and users. Much of the EnviroSuite research involves close collaboration with members of the Center for Environmental Molecular Science (CEMS), an EMSI based at BNL and nearby Stony Brook University and jointly supported by ERSD (Project 1023761, P. Kalb) and NSF. This offers unique opportunities to benefit from both national laboratory facilities and university resources. Other collaborators, from around the US and the world, investigate various aspects of the underlying molecular-scale processes in complex natural systems. In general, synchrotron techniques are ideal for studying the molecular-scale structures, chemical/physical interactions, and transformations that govern the macroscopic properties and processes (e.g. transport, bioavailability) of contaminants in the environment. These techniques are element-specific, non-destructive, and sensitive to the very low concentrations found in real-world samples.

  6. Assessment of murine bone ultrastructure using synchrotron light: towards nano-computed tomography

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; Voide, Romain; Stauber, Martin; Stampanoni, Marco; Donahue, Leah Rae; Wyss, Peter; Sennhauser, Urs; Müller, Ralph

    2006-08-01

    To describe the different aspects of bone quality, we follow a hierarchical approach and assess bone tissue properties in different regimes of spatial resolution, beginning at the organ level and going down to cellular dimensions. For these purposes we developed different synchrotron radiation (SR) based computed-tomography (CT) methods to assess murine bone ultrastructure. In a first step, a tubular system and the osteocyte lacunar system within murine cortical bone have been established as novel ultrastructural quantitative traits. Results in two mouse strains showed that morphometry of these quantitative traits was dependent on strain and partially on gender, and that their scaling behavior with bone size was fundamentally different. In a second step, we explored bone competence on an ultrastructural level and related our findings to the two ultrastructural quantitative traits introduced before. We showed that SR CT imaging is a powerful tool to investigate the initiation and propagation of microcracks, which may alter bone quality and may lead to increased fracture risk by means of microdamage accumulation. In summary, investigation of ultrastructural bone tissue properties will eventually lead to a better understanding of bone quality and its relative contribution to bone competence.

  7. X-ray photonic microsystems for the manipulation of synchrotron light

    SciTech Connect

    Mukhopadhyay, D.; Walko, D. A.; Jung, I. W.; Schwartz, C. P.; Wang, Jin; López, D.; Shenoy, G. K.

    2015-05-05

    In this study, photonic microsystems played an essential role in the development of integrated photonic devices, thanks to their unique spatiotemporal control and spectral shaping capabilities. Similar capabilities to markedly control and manipulate X-ray radiation are highly desirable but practically impossible due to the massive size of the silicon single-crystal optics currently used. Here we show that micromechanical systems can be used as X-ray optics to create and preserve the spatial, temporal and spectral correlation of the X-rays. We demonstrate that, as X-ray reflective optics they can maintain the wavefront properties with nearly 100% reflectivity, and as a dynamic diffractive optics they can generate nanosecond time windows with over 100-kHz repetition rates. Since X-ray photonic microsystems can be easily incorporated into lab-based and next-generation synchrotron X-ray sources, they bring unprecedented design flexibility for future dynamic and miniature X-ray optics for focusing, wavefront manipulation, multicolour dispersion, and pulse slicing.

  8. Operational Radiation Protection in Synchrotron Light and Free Electron Laser Facilities

    SciTech Connect

    Liu, James C.; Rokni, Sayed H.; Vylet, Vaclav; /Jefferson Lab

    2009-12-11

    The 3rd generation synchrotron radiation (SR) facilities are storage ring based facilities with many insertion devices and photon beamlines, and have low injection beam power (< few tens of watts), but extremely high stored beam power ({approx} 1 GW). The 4th generation x-ray free electron laser (FEL) facilities are based on an electron Linac with a long undulator and have high injection beam power (a few kW). Due to its electron and photon beam characteristics and modes of operation, storage ring and photon beamlines have unique safety aspects, which are the main subjects of this paper. The shielding design limits, operational modes, and beam losses are first reviewed. Shielding analysis (source terms and methodologies) and interlocked safety systems for storage ring and photon beamlines (including SR and gas bremsstrahlung) are described. Specific safety issues for storage ring top-off injection operation and FEL facilities are discussed. The operational safety program, e.g., operation authorization, commissioning, training, and radiation measurements, for SR facilities is also presented.

  9. X-ray photonic microsystems for the manipulation of synchrotron light

    DOE PAGESBeta

    Mukhopadhyay, D.; Walko, D. A.; Jung, I. W.; Schwartz, C. P.; Wang, Jin; López, D.; Shenoy, G. K.

    2015-05-05

    In this study, photonic microsystems played an essential role in the development of integrated photonic devices, thanks to their unique spatiotemporal control and spectral shaping capabilities. Similar capabilities to markedly control and manipulate X-ray radiation are highly desirable but practically impossible due to the massive size of the silicon single-crystal optics currently used. Here we show that micromechanical systems can be used as X-ray optics to create and preserve the spatial, temporal and spectral correlation of the X-rays. We demonstrate that, as X-ray reflective optics they can maintain the wavefront properties with nearly 100% reflectivity, and as a dynamic diffractivemore » optics they can generate nanosecond time windows with over 100-kHz repetition rates. Since X-ray photonic microsystems can be easily incorporated into lab-based and next-generation synchrotron X-ray sources, they bring unprecedented design flexibility for future dynamic and miniature X-ray optics for focusing, wavefront manipulation, multicolour dispersion, and pulse slicing.« less

  10. Conceptual Design Report for a Phase 3 upgrade of the National Synchrotron Light Source

    SciTech Connect

    Foyt, W.; Krinsky, S.; Hastings, J.; Finlay, L.

    1994-03-01

    Considerable investment by both the Department of Energy and the facility`s Participating Research teams has permitted the NSLS to offer a national facility to a wide range of scientific pursuits. The purpose of the NSLS Phase III project is to maximize the scientific output of this premier 2nd generation synchrotron radiation facility through a number of distinct projects. Over the years the NSLS has made significant improvements in the area of beam reliability which has resulted in deliverable, reproducible beam during 98% and 97% of scheduled operations on the VUV and X-ray rings respectively. This project will focus on improving beam intensity and stability by upgrading the optics and detector systems on a number of beamlines as well as upgrading radio frequency (rf) and beam position monitoring systems in the storage rings. In addition, the project includes plans for the design and procurement of a utility isolation system that would guard against voltage transients that disrupt the facility`s electrical system. Also a new insertion device will be installed at beamline X25 and a 2nd floor will be constructed over the X6 -- X16 region which will provide sorely needed laboratory and office space for the user community. This project requests funding of 22.5 million dollars over a three year period: FY 1996 ($6.3M), FY 1997 ($13.4M) and FY 1998 ($2.8M).

  11. X-ray photonic microsystems for the manipulation of synchrotron light

    PubMed Central

    Mukhopadhyay, D.; Walko, D. A.; Jung, I. W.; Schwartz, C. P.; Wang, Jin; López, D.; Shenoy, G. K.

    2015-01-01

    Photonic microsystems played an essential role in the development of integrated photonic devices, thanks to their unique spatiotemporal control and spectral shaping capabilities. Similar capabilities to markedly control and manipulate X-ray radiation are highly desirable but practically impossible due to the massive size of the silicon single-crystal optics currently used. Here we show that micromechanical systems can be used as X-ray optics to create and preserve the spatial, temporal and spectral correlation of the X-rays. We demonstrate that, as X-ray reflective optics they can maintain the wavefront properties with nearly 100% reflectivity, and as a dynamic diffractive optics they can generate nanosecond time windows with over 100-kHz repetition rates. Since X-ray photonic microsystems can be easily incorporated into lab-based and next-generation synchrotron X-ray sources, they bring unprecedented design flexibility for future dynamic and miniature X-ray optics for focusing, wavefront manipulation, multicolour dispersion, and pulse slicing. PMID:25940542

  12. Preliminary studies of enhanced contrast radiography in anatomy and embryology of insects with Elettra synchrotron light

    NASA Astrophysics Data System (ADS)

    Hönnicke, M. G.; Foerster, L. A.; Navarro-Silva, M. A.; Menk, R.-H.; Rigon, L.; Cusatis, C.

    2005-08-01

    Enhanced contrast X-ray imaging is achieved by exploiting the real part of the refraction index, which is responsible for the phase shifts, in addition to the imaginary part, which is responsible for the absorption. Such techniques are called X-ray phase contrast imaging. An analyzer-based X-ray phase contrast imaging set-up with Diffraction Enhanced Imaging processing (DEI) were used for preliminary studies in anatomy and embryology of insects. Parasitized stinkbug and moth eggs used as control agents of pests in vegetables and adult stinkbugs and mosquitoes ( Aedes aegypti) were used as samples. The experimental setup was mounted in the SYRMEP beamline at ELETTRA. Images were obtained using a high spatial resolution CCD detector (pixel size 14×14 μm 2) coupled with magnifying optics. Analyzer-based X-ray phase contrast images (PCI) and edge detection images show contrast and details not observed with conventional synchrotron radiography and open the possibility for future study in the embryonic development of insects.

  13. Estimating wide-angle, spatially varying reflectance using time-resolved inversion of backscattered light.

    PubMed

    Naik, Nikhil; Barsi, Christopher; Velten, Andreas; Raskar, Ramesh

    2014-05-01

    Imaging through complex media is a well-known challenge, as scattering distorts a signal and invalidates imaging equations. For coherent imaging, the input field can be reconstructed using phase conjugation or knowledge of the complex transmission matrix. However, for incoherent light, wave interference methods are limited to small viewing angles. On the other hand, time-resolved methods do not rely on signal or object phase correlations, making them suitable for reconstructing wide-angle, larger-scale objects. Previously, a time-resolved technique was demonstrated for uniformly reflecting objects. Here, we generalize the technique to reconstruct the spatially varying reflectance of shapes hidden by angle-dependent diffuse layers. The technique is a noninvasive method of imaging three-dimensional objects without relying on coherence. For a given diffuser, ultrafast measurements are used in a convex optimization program to reconstruct a wide-angle, three-dimensional reflectance function. The method has potential use for biological imaging and material characterization. PMID:24979627

  14. Resolving the CaP-bone interface: a review of discoveries with light and electron microscopy.

    PubMed

    Grandfield, Kathryn; Palmquist, Anders; Engqvist, Håkan; Thomsen, Peter

    2012-01-01

    It has long been known that the interfacial relationship between synthetic materials and tissue is influential in the success of implant materials. Instability at the implant interface has been shown, in some cases, to lead to complete implant failure. Bioceramics, and in particular calcium phosphates, form a large fraction of the implantable devices on the market today due to the biocompatibility they exhibit in contact with bone and tooth-like tissues. The characterization of such bioceramic-tissue interfaces has played a crucial role in understanding the behavior of bioceramics in vivo. In this review, we shed light on the preparation methods, technological approaches and key advances in resolving the interface between calcium phosphate bioceramics and bone, and share a future outlook on this field. PMID:23507782

  15. Angle-resolved spin wave band diagrams of square antidot lattices studied by Brillouin light scattering

    SciTech Connect

    Gubbiotti, G.; Tacchi, S.; Madami, M.; Carlotti, G.; Ding, J.; Adeyeye, A. O.

    2015-06-29

    The Brillouin light scattering technique has been exploited to study the angle-resolved spin wave band diagrams of squared Permalloy antidot lattice. Frequency dispersion of spin waves has been measured for a set of fixed wave vector magnitudes, while varying the wave vector in-plane orientation with respect to the applied magnetic field. The magnonic band gap between the two most dispersive modes exhibits a minimum value at an angular position, which exclusively depends on the product between the selected wave vector magnitude and the lattice constant of the array. The experimental data are in very good agreement with predictions obtained by dynamical matrix method calculations. The presented results are relevant for magnonic devices where the antidot lattice, acting as a diffraction grating, is exploited to achieve multidirectional spin wave emission.

  16. Performance of the far-IR beamline of the 6 MeV tabletop synchrotron light source.

    PubMed

    Monirul Haque, Md; Yamada, Hironari; Moon, Ahsa; Yamada, Mami

    2009-03-01

    The performance of the far-infrared (FIR) beamline of the 6 MeV tabletop synchrotron light source MIRRORCLE-6FIR dedicated to far-infrared spectroscopy is presented. MIRRORCLE-6FIR is equipped with a perfectly circular optical system (PhSR) placed around the 1 m-long circumference electron orbit. To illustrate the facility of this light source, the FIR output as well as its spectra were measured. The optimum optical system was designed by using the ray-tracing simulation code ZEMAX. The measured FIR intensity with the PhSR in place is about five times higher than that without the PhSR, which is in good agreement with the simulation results. The MIRRORCLE-6FIR spectral flux is compared with a standard thermal source and is found to be 1000 times greater than that from a typical thermal source at approximately 15 cm(-1). It is also observed that the MIRRORCLE-6FIR radiation has a highly coherent nature. The broadband infrared allows the facility to reach the spectral range from 10 cm(-1) to 100 cm(-1). MIRRORCLE-6FIR, owing to a large beam current, the PhSR mirror system, a large dynamic aperture and small ring energy, can deliver a bright flux of photons in the FIR/THz region useful for broadband spectroscopy. PMID:19240343

  17. THE Low-level Radio Frequency System for the superconducting cavities of National Synchrotron Light Source II

    SciTech Connect

    Ma, H.; Rose, J.; Holub, B.; Cupolo, J.; Oliva, J.; Sikora, R.; Yeddulla, M.

    2011-03-28

    A digital low-level radio frequency (LLRF) field controller has been developed for the storage ring of The National Synchrotron Light Source-II (NSLS-II). The primary performance goal for the LLRF is to support the required RF operation of the superconducting cavities with a beam current of 500mA and a 0.14 degree or better RF phase stability. The digital field controller is FPGA-based, in a standard format 19-inch/I-U chassis. It has an option of high-level control support with MATLAB running on a local host computer through a USB2.0 port. The field controller has been field tested with the high-power superconducting RF (SRF) at Canadian light Source, and successfully stored a high beam current of 250 mA. The test results show that required specifications for the cavity RF field stability are met. This digital field controller is also currently being used as a development platform for other functional modules in the NSLS-II RF systems.

  18. Complete time-resolved polarimetry of scattered light at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Turnbull, David; Ayers, Shannon; Bell, Perry; Chow, Robert; Frieders, Gene; Hibbard, Robin L.; Michel, Pierre; Ralph, Joseph E.; Ross, James S.; Stanley, Joel R.; Vickers, James L.; Zeid, Ziad M.; Moody, John D.

    2015-08-01

    The 3ω scattered light polarimetry diagnostic in the 30° incidence cone backscatter diagnostic at the National Ignition Facility (NIF) is being upgraded to measure the full time-resolved Stokes vector. Previously, the diagnostic had a single channel capable of diagnosing the time-integrated balance of the horizontal and vertical polarizations. Two additional channels were added - one that measures the balance of the 45° and 135° projections, and another that measures the right- and left-circular polarizations - and together the three complete the Stokes vector measurement. A division-of-aperture scheme is employed in which three nearby portions of the near field are sampled simultaneously. Time resolution is obtained by relaying an image of the measured regions onto a set of fibers coupled to diodes. The new diagnostic will be capable of measuring scattered light signals <≍ .1GW with ≍ 120ps time resolution. This will allow more rigorous evaluation of earlier indications that backscatter polarization can serve as a quantitative diagnostic of crossed-beam energy transfer in indirect-drive inertial confinement fusion experiments. It will also be used to diagnose Faraday rotation induced by magnetic fields in collisionless shock and turbulent dynamo experiments later this year.

  19. Time- and space-resolved light emission and spectroscopic research of the flashover plasma

    SciTech Connect

    Gleizer, J. Z.; Krasik, Ya. E.; Leopold, J.

    2015-02-21

    The results of an experimental study of the evolution of surface flashover across the surface of an insulator in vacuum subject to a high-voltage pulse and the parameters of the flashover plasma are reported. For the system studied, flashover is always initiated at the cathode triple junctions. Using time-resolved framing photography of the plasma light emission the velocity of the light emission propagation along the surface of the insulator was found to be ∼2.5·10{sup 8} cm/s. Spectroscopic measurements show that the flashover is characterized by a plasma density of 2–4 × 10{sup 14} cm{sup −3} and neutral and electron temperatures of 2–4 eV and 1–3 eV, respectively, corresponding to a plasma conductivity of ∼0.2 Ω{sup −1} cm{sup −1} and a discharge current density of up to ∼10 kA/cm{sup 2}.

  20. Improved optical profiling using the spectral phase in spectrally resolved white-light interferometry

    SciTech Connect

    Debnath, Sanjit Kumar; Kothiyal, Mahendra Prasad

    2006-09-20

    In spectrally resolved white-light interferometry (SRWLI), the white-light interferogram is decomposed into its monochromatic constituent. The phase of the monochromatic constituents can be determined using a phase-shifting technique over a range of wavelengths. These phase value shave fringe order ambiguity. However, the variation of the phase with respect to the wavenumber is linear and its slope gives the absolute value of the optical-path difference. Since the path difference is related to the height of the test object at a point, a line profile can be determined without ambiguity. The slope value, though less precise helps us determine the fringe order. The fringe order combined with the monochromatic phase value gives the absolute profile, which has the precision of phase-shifting interferometry. The presence of noise in the phase may lead to the misidentification of fringe order, which in turn gives unnecessary jumps in the precise profile. The experimental details of measurement on standard samples with SRWLI are discussed in this paper.

  1. NSLS 2006 ACTIVITY REPORT (NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 2006)

    SciTech Connect

    MILLER, L.

    2006-12-31

    This past year has seen both challenges and fantastic new opportunities for the user community at the NSLS. The fantastic new opportunities are clear and abundant. We now have a five-year strategic plan for new development and continued operation of the NSLS. The NSLS continues to be an extremely productive facility, and the UEC is delighted at how NSLS Chair Chi-Chang Kao has consulted widely within the user community to develop a five-year plan for strategic upgrades and continued operation of the facility. The NSLS-II project, led by Associate Lab Director Steve Dierker, has done very well in its Department of Energy (DOE) reviews and will hopefully soon receive Critical Decision-1 (CD-1) approval, which in DOE lingo gives a go-ahead to launch the detailed design of the facility. We also held the first joint user meeting between the NSLS and Brookhaven's Center for Functional Nanomaterials (CFN), for which the building is near completion. The joint user meeting is an important step toward the close collaboration of the two facilities. The CFN, led by Emilio Mendez, promises to provide capabilities and research foci that are complementary to those at the NSLS. Together, all of these developments give a clear path to an exciting future of synchrotron radiation research at Brookhaven! However, with opportunities come challenges! One of the largest of these faced in the past year involved congressional support for scientific research in general, and DOE user facilities in particular. As you likely know, Congress did not complete its usual budget process in 2006, with the exceptions of the departments of Defense and Homeland Security. This left science funding at the budget levels enacted in late 2005 for FY2006, and unfortunately, FY2006 was not a particularly memorable vintage for science support. The good news is that you, the user community, have spoken up with unprecedented vigor about this, and Congress appears to be listening. As we look at the FY2007 budget

  2. VLT Spectra "Resolve" a Stellar Disk at 25,000 Light-Years Distance

    NASA Astrophysics Data System (ADS)

    2001-04-01

    Unique Observations of a Microlensing Event Summary Like our Sun, stars are large gaseous spheres. However, while we are able to perceive the Sun's disk, all other stars are so far away that they normally appear as points of light . Only specialized observing techniques, like interferometry [1], are able to "resolve" the images of nearby stars and to show them as extended balls of fire. But opportunities may sometimes arise that allow amazing observational feats in this field . Indeed, an international team of astronomers [2] has just "resolved" a single, normal star some 25,000 light years away , or about 1.6 billion times more distant than the Sun [3], by taking advantage of a multiple microlensing event . During such a rare event, the light from the remote star is amplified by the gravity of a faint object that passes in front of it, as seen from the Earth . In fact, this gravitational lens acts as a magnifying glass that focusses different parts of the star's image at different times. Using the FORS1 multi-mode instrument at the 8.2-m VLT ANTU telescope on Paranal during a microlensing event, the team was able to obtain detailed spectra of the different parts of the remote star. In doing so, they managed to probe its gaseous atmosphere at different depths. This is the first time that it has been possible to obtain detailed, spatially resolved spectra across the full face of a normal star other than the Sun [4]. PR Photo 16a/01 : The light-curve of Microlensing Event EROS-BLG-2000-5 . PR Photo 16b/01 : The sky area of EROS-BLG-2000-5. PR Photo 16c/01 : A VLT spectrum of EROS-BLG-2000-5. PR Photo 16d/01 : The observed change of the H-alpha line strength of EROS-BLG-2000-5. A many-faceted success story The following story is about a most unusual astronomical observation and also shows how modern astrophysics works . It combines the study of stellar atmospheres with the intricate optical effects produced by the gravitational field of a binary star in the Milky Way

  3. Energy Spread Monitoring for the JLAB Experimental Program: Synchrotron Light Interferometers, Optical Transition Radiation Monitors, and Wire Scanners

    SciTech Connect

    Chao, Y.-C.; Chevtsov, P.; Day, A.; Freyberger, A. P.; Hicks, R.; Joyce, M.; Denard, J.-C.

    2004-11-10

    The hypernuclear physics program at JLAB requires an electron beam with small transverse size ({sigma} {approx} 100 {mu}m) and an upper limit on the RMS energy spread of ({delta}E/E) < 3 x 10{sup -5}. To measure and monitor these parameters, a beam size and energy spread measurement system has been created. The system consists of a set of wire scanners, Optical Transition Radiation (OTR) detectors, and Synchrotron Light Interferometers (SLI). The energy spread is measured via a set of wire scans performed at specific locations in the transport line, which is an invasive process. During physics operation the energy spread is monitored continuously with the OTR and/or the SLI. These devices are non-invasive [or nearly non-invasive in the case of OTR] and operate over a very wide range of beam energies (1-6 GeV) and currents ({approx}100 {mu}A down to few {mu}A). All components of this system are automated in an EPICS accelerator control environment. The paper presents our operational experience with the beam size and energy spread measurement system and its maintenance.

  4. Energy Spread Monitoring for the JLAB Experimental Program: Synchrotron Light Interferometers, Optical Transition Radiation Monitors and Wire Scanners

    SciTech Connect

    Arne Freyberger; Yu-Chiu Chao; Pavel Chevtsov; Anthony Day; William Hicks; Michele Joyce; Jean-Claude Denard

    2004-05-01

    The hypernuclear physics program at JLAB requires an electron beam with small transverse size (sigma {approx} 100 {micro}m) and an upper limit on the RMS energy spread of delta E / E < 3 x 10{sup -}5. To measure and monitor these parameters, a beam size and energy spread measurement system has been created. The system consists of a set of wire scanners, Optical Transition Radiation (OTR) detectors, and Synchrotron Light Interferometers (SLI). The energy spread is measured via a set of wire scans performed at specific locations in the transport line, which is an invasive process. During physics operation the energy spread is monitored continuously with the OTR and/or the SLI. These devices are noninvasive [or nearly non-invasive in the case of OTR] and operate over a very wide range of beam energies (1.6 GeV) and currents ({approx}100 {micro}A down to few {micro}A). All components of this system are automated in an EPICS accelerator control environment. The paper presents our operational experience with the beam size and energy spread measurement system and its maintenance.

  5. Development of an in-vacuum minipole undulator array for National Synchrotron Light Source In-Vacuum UNdulator

    SciTech Connect

    Tanabe, T.; Marechal, X.; Tanaka, T.; Kitamura, H.; Stefan, P.; Krinsky, S.; Rakowsky, G.; Solomon, L.

    1998-01-01

    An in-vacuum minipole (short period) insertion device has been developed in a collaboration between SPring-8 and the National Synchrotron Light Source (NSLS). The magnetic arrays were assembled, field measured, corrected, and vacuum tested by SPring-8 and were installed in an NSLS-developed chamber with mechanical parts in the NSLS X-Ray Ring (E=2.584GeV) in May 1997 and a successful commissioning of the device was carried out in June 1997. The device is made of permanent magnets with 30.5 periods and a period length of 11 mm. It is designed to produce fundamental radiation at 4.6 keV, and with a modest value of deflection parameter (K=0.7at3.3mm gap) enables higher harmonics to be used as well, for a variety of experiments. A detailed description of the mechanical support and vacuum chamber will be reported elsewhere. We describe technical challenges encountered in constructing this type of device, and present an outline of our collaboration. {copyright} {ital 1998 American Institute of Physics.}

  6. Magnetic measurements of permanent magnet insertion devices at the BNL-NSLS (Brookhaven National Laboratory--National Synchrotron Light Source)

    SciTech Connect

    Solomon, L.; Decker, G.; Galayda, J.; Kitamura, M.

    1989-01-01

    Since June 1988, three permanent magnet insertion devices of the hybrid type have been installed into the x-ray ring at the National Synchrotron Light Source at Brookhaven National Lab. as part of the Phase II facility upgrade. The three magnets consist of a soft x-ray undulator (SXU) and two hybrid wigglers, with peak fields of 0.35 and 1.2 Tesla respectively. The SXU magnet has iron poles, samarium cobalt permanent magnets, 80mm period length, 77 poles, and a gap range of 31--100 mm. For this gap range the undulator parameter K, where K = 0.934 B(Tesla)/lambda/(cm), ranges from 2.6 to 0.15. The hybrid wigglers have vanadium pomander poles, samarium cobalt magnets, 120MM periods, 31 poles, and a gap range of 22--122mm. For this gap range K ranges from 13.0 to 0.5. All three of these magnets have electromagnetic coils which can be powered to adjust the value of the magnet field integral. Both point and integral magnetic measurements were performed on these magnets; some of the measurement results will be presented in this paper.

  7. Design of a diagnostic area-type beam position monitor for x-ray beamlines at the National Synchrotron Light Source

    SciTech Connect

    Corridon, D.

    1996-10-01

    We have built a area-type beam position monitor for use as a diagnostic tool at the National Synchrotron Light Source. The device is compact and fits into a vacuum cross. We completed range and resolution tests of the device at beamline X-19A at the NSLS and concluded that such a monitor can be placed in the confines of the vacuum cross.

  8. Soft-x-ray and vacuum-ultraviolet beamlines at the National Synchrotron Light Source 700-MeV storage ring

    SciTech Connect

    Williams, G.P.; Howells, M.R.

    1982-01-01

    We summarize the characteristics of the first beamlines which are being installed and commissioned at the National Synchrotron Light Source (NSLS) 700 MeV storage ring at Brookhaven National Laboratory. We also give a progress report as of July 1982 on the early stages of beamline alignment and operation in which particular attention is paid to the 5 beamlines which NSLS has developed. The report describes in detail a novel method for beamline alignment which is of general application.

  9. Time-Resolved Light Scattering and Fluorescence Spectroscopy in Biomedical and Model Random Media

    NASA Astrophysics Data System (ADS)

    Das, Bidyut Baran

    Optical spectroscopy, light scattering and ultrafast time-gated imaging have been shown to offer novel approaches to study the optical characteristics of various biomedical and other random media. Fluorescence spectra from human malignant and nonmalignant breast tissues were measured at 300 nm excitation and a significant spectral difference was found between the two tissue types by using the ratio of fluorescence intensities at 340 and 440 nm. Optical density measurements on thin breast tissues show that the scattering cross-sections of breast tissues are relatively constant over the visible and the uv region. Transport mean free paths and the absorption lengths for various tissues and model random media were measured using time-resolved transmission. The scattering coefficients for human breast and chicken tissues were found to remain relatively constant in 570-630 nm wavelength region while they change significantly at 1064 nm. Chicken breast and fat tissues were found to be good models for human breast tissues as the values of the optical parameters of the two tissue types are about the same. The less scattering observed at 1064 nm makes tissues more transparent in the NIR region making it easier to image in thick tissues. Time-resolved backscattering measurements show that the scattering and the absorption parameters of a random medium can be obtained accurately in a two-fiber configuration as long as the radial distance is more than about seven times the transport mean free path of the sample. The single point source-detection configuration provides a tool to diagnose breast malignancy though it fails to give accurate values of the optical parameters of tissues. This failure is attributed to the invalidity of the diffusion approximation in this experimental configuration. A 2.5 mm thin chicken fat strip was imaged inside a 40 mm thick chicken breast tissue using snake photons at 625 nm with ultrafast time-gated detection. A simple model to describe the effect

  10. VLT Spectra "Resolve" a Stellar Disk at 25,000 Light-Years Distance

    NASA Astrophysics Data System (ADS)

    2001-04-01

    Unique Observations of a Microlensing Event Summary Like our Sun, stars are large gaseous spheres. However, while we are able to perceive the Sun's disk, all other stars are so far away that they normally appear as points of light . Only specialized observing techniques, like interferometry [1], are able to "resolve" the images of nearby stars and to show them as extended balls of fire. But opportunities may sometimes arise that allow amazing observational feats in this field . Indeed, an international team of astronomers [2] has just "resolved" a single, normal star some 25,000 light years away , or about 1.6 billion times more distant than the Sun [3], by taking advantage of a multiple microlensing event . During such a rare event, the light from the remote star is amplified by the gravity of a faint object that passes in front of it, as seen from the Earth . In fact, this gravitational lens acts as a magnifying glass that focusses different parts of the star's image at different times. Using the FORS1 multi-mode instrument at the 8.2-m VLT ANTU telescope on Paranal during a microlensing event, the team was able to obtain detailed spectra of the different parts of the remote star. In doing so, they managed to probe its gaseous atmosphere at different depths. This is the first time that it has been possible to obtain detailed, spatially resolved spectra across the full face of a normal star other than the Sun [4]. PR Photo 16a/01 : The light-curve of Microlensing Event EROS-BLG-2000-5 . PR Photo 16b/01 : The sky area of EROS-BLG-2000-5. PR Photo 16c/01 : A VLT spectrum of EROS-BLG-2000-5. PR Photo 16d/01 : The observed change of the H-alpha line strength of EROS-BLG-2000-5. A many-faceted success story The following story is about a most unusual astronomical observation and also shows how modern astrophysics works . It combines the study of stellar atmospheres with the intricate optical effects produced by the gravitational field of a binary star in the Milky Way

  11. Synchrotron radiation from protons

    SciTech Connect

    Dutt, S.K.

    1992-12-01

    Synchrotron radiation from protons, though described by the same equations as the radiation from electrons, exhibits a number of interesting features on account of the parameters reached in praxis. In this presentation, we shall point out some of the features relating to (i) normal synchrotron radiation from dipoles in proton machines such as the High Energy Booster and the Superconducting Super Collider; (ii) synchrotron radiation from short dipoles, and its application to light monitors for proton machines, and (iii) synchrotron radiation from undulators in the limit when, the deflection parameter is much smaller than unity. The material for this presentation is taken largely from the work of Hofmann, Coisson, Bossart, and their collaborators, and from a paper by Kim. We shall emphasize the qualitative aspects of synchrotron radiation in the cases mentioned above, making, when possible, simple arguments for estimating the spectral and angular properties of the radiation. Detailed analyses can be found in the literature.

  12. Spatially resolved electroluminescence of InGaN-MQW-LEDs[Multiple Quantum Wells-Light Emitting Diodes

    SciTech Connect

    Schwegler, V.; Seyboth, M.; Kirchner, C.; Scherer, M.; Kamp, M.; Fischer, P.; Christen, J.; Zacharias, M.

    2000-07-01

    Electroluminescence (EL) is the most significant measure for light-emitting diodes since it probes the most relevant properties of the fully processed device during operation. In addition to the information gained by conventional spectrally resolved EL, scanning micro-EL provides spatially resolved information. The devices under investigation are InGaN/GaN-LEDs with single peak band-band emission at about 400 nm grown by MOVPE on sapphire substrates. The {mu}-EL-characterization is performed as a function of injection current densities and the emission is investigated from the epitaxial layer as well as from substrate side. Spatially resolved wavelength images reveal emission peaks between 406 nm and 417 nm, corresponding either to In fluctuations of 1--1.5% or local fluctuations of piezo electric fields. Beside the information on the emission wavelength fluctuations {mu}-EL is used to determine the temperature distribution in the LEDs and to investigate transparent contacts.

  13. Development of an x-ray fluorescence microprobe at the National Synchrotron Light Source, Brookhaven National Laboratory: Early results: Comparison with data from other techniques

    SciTech Connect

    Smith, J.V.; Rivers, M.L.; Sutton, S.R.; Jones, K.W.; Hanson, A.L.; Gordon, B.M.

    1986-01-01

    Theoretical predictions for the detection levels in x-ray fluorescence analysis with a synchrotron storage ring are being achieved experimentally at several laboratories. This paper is deliberately restricted to the state of development of the Brookhaven National Laboratory/University of Chicago instruments. Analyses at the parts per million (ppM) level are being made using white light apertured to 20 ..mu..m and an energy dispersive system. This system is particularly useful for elements with Z > 20 in materials dominated by elements with Z < 20. Diffraction causes an interference for crystalline materials. Development of a focusing microprobe for tunable monochromatic x-rays and a wavelength dispersive spectrometer (WDS) is delayed by problems in shaping an 8:1 focusing mirror to the required accuracy. Reconnaissance analyses with a wiggler source on the CHESS synchrotron have been made in the K spectrum up to Z = 80.

  14. Spectrally resolved white light interferometry to measure material dispersion over a wide spectral band in a single acquisition.

    PubMed

    Arosa, Yago; Lago, Elena López; Varela, Luis Miguel; de la Fuente, Raúl

    2016-07-25

    In this paper we apply spectrally resolved white light interferometry to measure refractive and group index over a wide spectral band from 400 to 1000 nm. The output of a Michelson interferometer is spectrally decomposed by a homemade prism spectrometer with a high resolution camera. The group index is determined directly from the phase extracted from the spectral interferogram while the refractive index is estimated once its value at a given wavelength is known. PMID:27464179

  15. Synchrotron polarization in blazars

    SciTech Connect

    Zhang, Haocheng; Böttcher, Markus; Chen, Xuhui

    2014-07-01

    We present a detailed analysis of time- and energy-dependent synchrotron polarization signatures in a shock-in-jet model for γ-ray blazars. Our calculations employ a full three-dimensional radiation transfer code, assuming a helical magnetic field throughout the jet. The code considers synchrotron emission from an ordered magnetic field, and takes into account all light-travel-time and other relevant geometric effects, while the relevant synchrotron self-Compton and external Compton effects are handled with the two-dimensional Monte-Carlo/Fokker-Planck (MCFP) code. We consider several possible mechanisms through which a relativistic shock propagating through the jet may affect the jet plasma to produce a synchrotron and high-energy flare. Most plausibly, the shock is expected to lead to a compression of the magnetic field, increasing the toroidal field component and thereby changing the direction of the magnetic field in the region affected by the shock. We find that such a scenario leads to correlated synchrotron + synchrotron-self-Compton flaring, associated with substantial variability in the synchrotron polarization percentage and position angle. Most importantly, this scenario naturally explains large polarization angle rotations by ≳ 180°, as observed in connection with γ-ray flares in several blazars, without the need for bent or helical jet trajectories or other nonaxisymmetric jet features.

  16. Synchrotron Polarization in Blazars

    NASA Astrophysics Data System (ADS)

    Zhang, Haocheng; Chen, Xuhui; Böttcher, Markus

    2014-07-01

    We present a detailed analysis of time- and energy-dependent synchrotron polarization signatures in a shock-in-jet model for γ-ray blazars. Our calculations employ a full three-dimensional radiation transfer code, assuming a helical magnetic field throughout the jet. The code considers synchrotron emission from an ordered magnetic field, and takes into account all light-travel-time and other relevant geometric effects, while the relevant synchrotron self-Compton and external Compton effects are handled with the two-dimensional Monte-Carlo/Fokker-Planck (MCFP) code. We consider several possible mechanisms through which a relativistic shock propagating through the jet may affect the jet plasma to produce a synchrotron and high-energy flare. Most plausibly, the shock is expected to lead to a compression of the magnetic field, increasing the toroidal field component and thereby changing the direction of the magnetic field in the region affected by the shock. We find that such a scenario leads to correlated synchrotron + synchrotron-self-Compton flaring, associated with substantial variability in the synchrotron polarization percentage and position angle. Most importantly, this scenario naturally explains large polarization angle rotations by >~ 180°, as observed in connection with γ-ray flares in several blazars, without the need for bent or helical jet trajectories or other nonaxisymmetric jet features.

  17. Spin-resolved photoelectron spectroscopy using femtosecond extreme ultraviolet light pulses from high-order harmonic generation.

    PubMed

    Plötzing, M; Adam, R; Weier, C; Plucinski, L; Eich, S; Emmerich, S; Rollinger, M; Aeschlimann, M; Mathias, S; Schneider, C M

    2016-04-01

    The fundamental mechanism responsible for optically induced magnetization dynamics in ferromagnetic thin films has been under intense debate since almost two decades. Currently, numerous competing theoretical models are in strong need for a decisive experimental confirmation such as monitoring the triggered changes in the spin-dependent band structure on ultrashort time scales. Our approach explores the possibility of observing femtosecond band structure dynamics by giving access to extended parts of the Brillouin zone in a simultaneously time-, energy- and spin-resolved photoemission experiment. For this purpose, our setup uses a state-of-the-art, highly efficient spin detector and ultrashort, extreme ultraviolet light pulses created by laser-based high-order harmonic generation. In this paper, we present the setup and first spin-resolved spectra obtained with our experiment within an acquisition time short enough to allow pump-probe studies. Further, we characterize the influence of the excitation with femtosecond extreme ultraviolet pulses by comparing the results with data acquired using a continuous wave light source with similar photon energy. In addition, changes in the spectra induced by vacuum space-charge effects due to both the extreme ultraviolet probe- and near-infrared pump-pulses are studied by analyzing the resulting spectral distortions. The combination of energy resolution and electron count rate achieved in our setup confirms its suitability for spin-resolved studies of the band structure on ultrashort time scales. PMID:27131684

  18. Spin-resolved photoelectron spectroscopy using femtosecond extreme ultraviolet light pulses from high-order harmonic generation

    NASA Astrophysics Data System (ADS)

    Plötzing, M.; Adam, R.; Weier, C.; Plucinski, L.; Eich, S.; Emmerich, S.; Rollinger, M.; Aeschlimann, M.; Mathias, S.; Schneider, C. M.

    2016-04-01

    The fundamental mechanism responsible for optically induced magnetization dynamics in ferromagnetic thin films has been under intense debate since almost two decades. Currently, numerous competing theoretical models are in strong need for a decisive experimental confirmation such as monitoring the triggered changes in the spin-dependent band structure on ultrashort time scales. Our approach explores the possibility of observing femtosecond band structure dynamics by giving access to extended parts of the Brillouin zone in a simultaneously time-, energy- and spin-resolved photoemission experiment. For this purpose, our setup uses a state-of-the-art, highly efficient spin detector and ultrashort, extreme ultraviolet light pulses created by laser-based high-order harmonic generation. In this paper, we present the setup and first spin-resolved spectra obtained with our experiment within an acquisition time short enough to allow pump-probe studies. Further, we characterize the influence of the excitation with femtosecond extreme ultraviolet pulses by comparing the results with data acquired using a continuous wave light source with similar photon energy. In addition, changes in the spectra induced by vacuum space-charge effects due to both the extreme ultraviolet probe- and near-infrared pump-pulses are studied by analyzing the resulting spectral distortions. The combination of energy resolution and electron count rate achieved in our setup confirms its suitability for spin-resolved studies of the band structure on ultrashort time scales.

  19. Direct observation of a resolvable spin separation in the spin Hall effect of light at an air-glass interface

    SciTech Connect

    Ren, Jin-Li; Wang, Bo; Xiao, Yun-Feng; Gong, Qihuang; Li, Yan

    2015-09-14

    We theoretically and experimentally demonstrate that it is possible to directly observe the resolvable spin separation in the spin Hall effect of light at an air-glass interface by choosing optimal parameters. When a P-polarized light with a beam waist of 10 μm is incident around Brewster's angle, the two spin components of the reflected beam can be completely separated by eliminating the influence of the in-plane wavevector spread. This not only obviously reveals the strong impacts of the polarization state, the incident angle, the beam waist, and the in-plane wavevector spread, but also intuitively visualizes the observation of the spin Hall effect of light.

  20. Fluorescence dynamics of biological systems using synchrotron radiation

    SciTech Connect

    Gratton, E.; Mantulin, W.W.; Weber, G.; Royer, C.A.; Jameson, D.M.; Reininger, R.; Hansen, R.

    1996-09-01

    A beamline for time-resolved fluorescence spectroscopy of biological systems is under construction at the Synchrotron Radiation Center. The fluorometer, operating in the frequency domain, will take advantage of the time structure of the synchrotron radiation light pulses to determine fluorescence lifetimes. Using frequency-domain techniques, the instrument can achieve an ultimate time resolution on the order of picoseconds. Preliminary experiments have shown that reducing the intensity of one of the fifteen electron bunches in the storage ring allows measurement of harmonic frequencies equivalent to the single-bunch mode. This mode of operation of the synchrotron significantly extends the range of lifetimes that can be measured. The wavelength range (encompassing the visible and ultraviolet), the range of measurable lifetimes, and the stability and reproducibility of the storage ring pulses should make this beamline a versatile tool for the investigation of the complex fluorescence decay of biological systems. {copyright} {ital 1996 American Institute of Physics.}

  1. High-resolution three-dimensional spin- and angle-resolved photoelectron spectrometer using vacuum ultraviolet laser light

    NASA Astrophysics Data System (ADS)

    Yaji, Koichiro; Harasawa, Ayumi; Kuroda, Kenta; Toyohisa, Sogen; Nakayama, Mitsuhiro; Ishida, Yukiaki; Fukushima, Akiko; Watanabe, Shuntaro; Chen, Chuangtian; Komori, Fumio; Shin, Shik

    2016-05-01

    We describe a spin- and angle-resolved photoelectron spectroscopy (SARPES) apparatus with a vacuum-ultraviolet (VUV) laser (hν = 6.994 eV) developed at the Laser and Synchrotron Research Center at the Institute for Solid State Physics, The University of Tokyo. The spectrometer consists of a hemispherical photoelectron analyzer equipped with an electron deflector function and twin very-low-energy-electron-diffraction-type spin detectors, which allows us to analyze the spin vector of a photoelectron three-dimensionally with both high energy and angular resolutions. The combination of the high-performance spectrometer and the high-photon-flux VUV laser can achieve an energy resolution of 1.7 meV for SARPES. We demonstrate that the present laser-SARPES machine realizes a quick SARPES on the spin-split band structure of a Bi(111) film even with 7 meV energy and 0.7∘ angular resolutions along the entrance-slit direction. This laser-SARPES machine is applicable to the investigation of spin-dependent electronic states on an energy scale of a few meV.

  2. High-resolution three-dimensional spin- and angle-resolved photoelectron spectrometer using vacuum ultraviolet laser light.

    PubMed

    Yaji, Koichiro; Harasawa, Ayumi; Kuroda, Kenta; Toyohisa, Sogen; Nakayama, Mitsuhiro; Ishida, Yukiaki; Fukushima, Akiko; Watanabe, Shuntaro; Chen, Chuangtian; Komori, Fumio; Shin, Shik

    2016-05-01

    We describe a spin- and angle-resolved photoelectron spectroscopy (SARPES) apparatus with a vacuum-ultraviolet (VUV) laser (hν = 6.994 eV) developed at the Laser and Synchrotron Research Center at the Institute for Solid State Physics, The University of Tokyo. The spectrometer consists of a hemispherical photoelectron analyzer equipped with an electron deflector function and twin very-low-energy-electron-diffraction-type spin detectors, which allows us to analyze the spin vector of a photoelectron three-dimensionally with both high energy and angular resolutions. The combination of the high-performance spectrometer and the high-photon-flux VUV laser can achieve an energy resolution of 1.7 meV for SARPES. We demonstrate that the present laser-SARPES machine realizes a quick SARPES on the spin-split band structure of a Bi(111) film even with 7 meV energy and 0.7(∘) angular resolutions along the entrance-slit direction. This laser-SARPES machine is applicable to the investigation of spin-dependent electronic states on an energy scale of a few meV. PMID:27250396

  3. Archival Legacy Investigations of Circumstellar Environments (ALICE): Debris Disks Newly Resolved in Scattered Light from the HST NICMOS Archive

    NASA Astrophysics Data System (ADS)

    Moerchen, Margaret; Perrin, M. D.; Chen, C.; Choquet, E.; Debes, J. H.; Golimowski, D. A.; Hagan, J.; Hines, D. C.; Mittal, T.; N'Diaye, M.; Pueyo, L.; Reid, I. N.; Schneider, G.; Wolff, S.; Soummer, R.

    2014-01-01

    We have spatially resolved four new debris disks in scattered light for the first time through the analysis of archival HST NICMOS coronagraphic images. These disks around 12-30-Myr-old main-sequence F or G stars were revealed by reprocessing recalibrated archival images (HST AR program LAPLACE; PI Schneider) with a novel pipeline that improves the subtraction of the PSF (ALICE; Soummer et al. 2012). Three of these disks (HD 30447, HD 35841, and HD 141943) appear to be edge-on, and the fourth (HD 191089) appears to be an asymmetric inclined ring. We describe our modeling efforts so far that take into account all available photometry and resolved images for these sources. We employ the 3D radiative transfer code MCFOST (Pinte et al. 2008), which enables the reconstruction of SEDs and images according to the specified dust composition and disk morphology.

  4. Ultrafast time-resolved spectroscopy of the light-harvesting complex 2 (LH2) from the photosynthetic bacterium Thermochromatium tepidum

    SciTech Connect

    Niedzwiedzki, Dariusz M.; Fuciman, Marcel; Kobayashi, Masayuki; Frank, Harry A.; Blankenship, Robert E.

    2011-10-08

    The light-harvesting complex 2 from the thermophilic purple bacterium Thermochromatium tepidum was purified and studied by steady-state absorption and fluorescence, sub-nanosecond-time-resolved fluorescence and femtosecond time-resolved transient absorption spectroscopy. The measurements were performed at room temperature and at 10 K. The combination of both ultrafast and steady-state optical spectroscopy methods at ambient and cryogenic temperatures allowed the detailed study of carotenoid (Car)-to-bacteriochlorophyll (BChl) as well BChl-to-BChl excitation energy transfer in the complex. The studies show that the dominant Cars rhodopin (N = 11) and spirilloxanthin (N = 13) do not play a significant role as supportive energy donors for BChl a. This is related with their photophysical properties regulated by long π-electron conjugation. On the other hand, such properties favor some of the Cars, particularly spirilloxanthin (N = 13) to play the role of the direct quencher of the excited singlet state of BChl.

  5. Photocycles of bacteriorhodopsin in light- and dark-adapted purple membrane studied by time-resolved absorption spectroscopy.

    PubMed Central

    Hofrichter, J; Henry, E R; Lozier, R H

    1989-01-01

    Nanosecond time-resolved absorption spectra have been measured throughout the photocycle of bacteriorhodopsin in both light-adapted and dark-adapted purple membrane (PM). The data from dark-adapted samples are interpretable as the superposition of two photocycles arising independently from the all-trans and 13-cis retinal isomers that coexist in the dark-adapted state. The presence of a photocycle in dark-adapted PM which is indistinguishable from that observed for light-adapted PM under the same experimental conditions is demonstrated by the observation of the same five relaxation rates associated with essentially identical changes in the photoproduct spectra. This cycle is attributed to the all-trans component. The cycle of the 13-cis component is revealed by scaling the data measured for the light-adapted sample and subtracting it from the data on the dark-adapted mixture. At times less than 1 ms, the resulting difference spectra are nearly time-independent. The peak of the difference spectrum is near 600 nm, although there appears to be a slight (approximately 2 nm) blue-shift in the first few microseconds. Subsequently the amplitude of this spectrum decays and the peak of the difference spectrum shifts in two relaxations. Most of the amplitude of the photoproduct difference spectrum (approximately 80%) decays in a single relaxation having a time constant of approximately 35 ms. The difference spectrum remaining after this relaxation peaks at approximately 590 nm and is indistinguishable from the classical light-dark difference spectrum, which we find, in experiments performed on a much longer time scale, to peak at 588 nm. The decay of this remaining photo-product is not resolvable in the nanosecond kinetic experiments, but dark adaptation of a completely light-adapted sample is found to occur exponentially with a relaxation time of approximately 2,000 s under the conditions of our experiments. PMID:2819234

  6. Introducing Synchrotrons Into the Classroom

    ScienceCinema

    None

    2013-07-22

    Brookhaven's Introducing Synchrotrons Into the Classroom (InSynC) program gives teachers and their students access to the National Synchrotron Light Source through a competitive proposal process. The first batch of InSynC participants included a group of students from Islip Middle School, who used the massive machine to study the effectiveness of different what filters.

  7. Introducing Synchrotrons Into the Classroom

    SciTech Connect

    2011-05-20

    Brookhaven's Introducing Synchrotrons Into the Classroom (InSynC) program gives teachers and their students access to the National Synchrotron Light Source through a competitive proposal process. The first batch of InSynC participants included a group of students from Islip Middle School, who used the massive machine to study the effectiveness of different what filters.

  8. A sessile drop setup for the time-resolved synchrotron study of solid-liquid interactions: Application to intermetallic formation in 55%Al-Zn alloys

    SciTech Connect

    Bernier, N. De Bruyn, D.; De Craene, M.; Scheers, J.; Claessens, S.; Vaughan, G. B. M.; Vitoux, H.; Gleyzolle, H.; Gorges, B.

    2014-04-28

    We introduce a dedicated setup for measuring by synchrotron diffraction in-situ crystallographic and chemical information at the solid–liquid interface. This setup mostly consists of a double-heating furnace composed of a resistive heating for the solid surface and an inductive heating to produce a liquid droplet. The available high energy and high flux beams allow the rapid reaction kinetics to be investigated with very good time resolution down to 1 ms. An application of this setup is illustrated for the growth mechanisms of intermetallic phases during the hot-dipping of steel in a 55%Al-Zn bath. Results show that the three η-Al{sub 5}Fe{sub 2}, θ-Al{sub 13}Fe{sub 4}, and α-Al{sub 8}Fe{sub 2}Si phases grow at different times and rates during the dipping process, whereas the face-centered cubic AlFe{sub 3} phase is not formed.

  9. Nanophase evolution at semiconductor/electrolyte interface in situ probed by time-resolved high-energy synchrotron x-ray diffraction.

    SciTech Connect

    Sun, Y.; Ren, Y.; Haeffner, D. R.; Almer, J. D.; Wang, L.; Yang, W.; Truong, T. T.

    2010-09-01

    Real-time evolution of nanoparticles grown at the semiconductor/electrolyte interface formed between a single crystalline n-type GaAs wafer and an aqueous solution of AgNO{sub 3} has been studied by using high-energy synchrotron X-ray diffraction. The results reveal the distinct nucleation and growth steps involved in the growth of anisotropic Ag nanoplates on the surface of the GaAs wafer. For the first time, a quick transit stage is observed to be responsible for the structural transformation of the nuclei to form structurally stable seeds that are critical for guiding their anisotropic growth into nanoplates. Reaction between a GaAs wafer and AgNO{sub 3} solution at room temperature primarily produces Ag nanoplates on the surface of the GaAs wafer in the dark and at room temperature. In contrast, X-ray irradiation can induce charge separation in the GaAs wafer to drive the growth of nanoparticles made of silver oxy salt (Ag{sub 7}NO{sub 11}) and silver arsenate (Ag{sub 3}AsO{sub 4}) at the semiconductor/electrolyte interface if the GaAs wafer is illuminated by the X-ray and reaction time is long enough.

  10. Influence of structural length-scale variations on azimuth-resolved light scattering patterns of inhomogeneous cell models

    NASA Astrophysics Data System (ADS)

    Arifler, Dizem; Guillaud, Martial

    2015-07-01

    Optical scattering provides an intrinsic contrast mechanism for the diagnosis of early precancerous changes in tissues. There have been a multitude of numerical studies targeted at delineating the relationship between cancer-related alterations in morphology and internal structure of cells and the resulting changes in their optical scattering properties. Despite these efforts, we still need to further our understanding of inherent scattering signatures that can be linked to precancer progression. As such, computational studies aimed at relating electromagnetic wave interactions to cellular and subcellular structural alterations are likely to provide a quantitative framework for a better assessment of the diagnostic content of optical signals. In this study, we aim to determine the influence of structural length-scale variations on two-dimensional light scattering properties of cells. We numerically construct cell models with different lower bounds on the size of refractive index heterogeneities and we employ the finite-difference time-domain method to compute their azimuth-resolved light scattering patterns. The results indicate that changes in length-scale variations can significantly alter the two-dimensional scattering patterns of cell models. More specifically, the degree of azimuthal asymmetry characterizing these patterns is observed to be highly dependent on the range of length-scale variations. Overall, the study described here is expected to offer useful insights into whether azimuth-resolved measurements can be explored for diagnostic purposes.