WorldWideScience

Sample records for generation light sources

  1. Fifth generation light sources

    Science.gov (United States)

    Romaniuk, Ryszard S.

    2016-12-01

    Coherent light sources are one of the most fundamental research tools in biology, technology and in other areas. Synchrotron light source consists of a few basic parts: energy source - which is an electron beam accelerator, energy converter between electron and photon beams - which is an undulator, and photon user experimental lines. Each of these parts is separately a complex system, which is currently a subject to fast technological development. Future light sources of the fifth generation are based on completely new solutions of these fundamental parts, in comparison with the sources of the previous generations. Energy source is a new generation laser - plasma accelerator with electrical field in the area of multiple GV/m. A miniature undulator is tested in the MEMS technology from new materials. Classical light beam lines, vacuum, and difficult for management and beam distribution, change their meaning in the case of availability of miniature undulators positioned immediately at or even inside the experimental stations. After an introduction concerning the light sources of the previous generations, the article shows current research efforts on the mentioned key components of the fifth generation light sources. In some cases this is a continuation and modernization of the previous technologies, in the majority it is a brave endeavour to apply completely new technologies, like laser - plasma acceleration.

  2. Iranian Light Source Facility, A third generation light source laboratory

    Directory of Open Access Journals (Sweden)

    J Rahighi

    2015-09-01

    Full Text Available The Iranian Light Source Facility (ILSF project is the first large scale accelerator facility which is currently under planning in Iran. On the basis of the present design, circumference of the 3 GeV storage ring is 528 m. Beam current and natural beam emittance are 400 mA and 0.477 nm.rad, respectively. Some prototype accelerator components such as high power solid state radio frequency amplifiers, low level RF system, thermionic RF gun, H-type dipole and quadruple magnets, magnetic measurement laboratory and highly stable magnet power supplies have been constructed at ILSF R&D laboratory

  3. Synchronization System for Next Generation Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Zavriyev, Anton

    2014-03-27

    An alternative synchronization technique – one that would allow explicit control of the pulse train including its repetition rate and delay is clearly desired. We propose such a scheme. Our method is based on optical interferometry and permits synchronization of the pulse trains generated by two independent mode-locked lasers. As the next generation x-ray sources will be driven by a clock signal derived from a mode-locked optical source, our technique will provide a way to synchronize x-ray probe with the optical pump pulses.

  4. RF Sources for 3rd & 4th Generation Light Sources

    CERN Document Server

    Lenci, Stephan; Bohlen, Heinz Peter; Mizuhara, Albert; Wright, Edward L

    2004-01-01

    The growing number of third and fourth generation light sources has resulted in an increase of the available rf sources to power them. Single beam klystrons are the traditional power source, but the development of IOT’s and multiple-beam klystrons (MBK’s) in L-Band have increased the options for these machines. The Eimac division of CPI has recently built and tested a prototype L-Band IOT, which delivered 30 kW CW at 1.3 GHz. Future work includes the building of an IOT at 1.5 GHz. Meanwhile the MPP division of CPI is currently testing the prototype 10 MW peak, 1.3 GHz MBK for the TESLA x-ray free-electron laser (XFEL). Test results for these new products as well as information on all CPI products at 500 MHz, 1.3 GHz, and 1.5 GHz will be presented.

  5. The 4th Generation Light Source at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Albert Grippo; Christopher Gould; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; Kevin Jordan; John Klopf; Steven Moore; George Neil; Thomas Powers; Joseph Preble; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Shukui Zhang; Gwyn Williams

    2007-04-25

    A number of "Grand Challenges" in Science have recently been identified in reports from The National Academy of Sciences, and the U.S. Dept. of Energy, Basic Energy Sciences. Many of these require a new generation of linac-based light source to study dynamical and non-linear phenomena in nanoscale samples. In this paper we present a summary of the properties of such light sources, comparing them with existing sources, and then describing in more detail a specific source at Jefferson Lab. Importantly, the JLab light source has developed some novel technology which is a critical enabler for other new light sources.

  6. Generating polarization controllable FELs at Dalian coherent light source

    CERN Document Server

    Zhang, T; Wang, D; Zhao, Z T; Zhang, W Q; Wu, G R; Dai, D X; Yang, X M

    2013-01-01

    The property of the FEL polarization is of great importance to the user community. FEL pulses with ultra-high intensity and flexible polarization control ability will absolutely open up new scientific realms. In this paper, several polarization control approaches are presented to investigate the great potential on Dalian coherent light source, which is a government-approved novel FEL user facility with the capability of wavelength continuously tunable in the EUV regime of 50-150 nm. The numerical simulations show that both circularly polarized FELs with highly modulating frequency and 100 microjoule level pulse energy could be generated at Dalian coherent light source.

  7. Electron Beam Collimation for the Next Generation Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Steier, C.; Emma, P.; Nishimura, H.; Papadopoulos, C.; Sannibale, F.

    2013-05-20

    The Next Generation Light Source will deliver high (MHz) repetition rate electron beams to an array of free electron lasers. Because of the significant average current in such a facility, effective beam collimation is extremely important to minimize radiation damage to undulators, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the early conceptual design of a collimation system, as well as initial results of simulations to test its effectiveness.

  8. JLab CW Cryomodules for 4th Generation Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Rimmer, Robert; Bundy, Richard; Cheng, Guangfeng; Ciovati, Gianluigi; Clemens, William; Daly, Edward; Henry, James; Hicks, William; Kneisel, Peter; Manning, Stephen; Manus, Robert; Marhauser, Frank; Preble, Joseph; Reece, Charles; Smith, Karl; Stirbet, Mircea; Turlington, Larry; Wang, Haipeng; Wilson, Katherine

    2008-01-23

    Fourth generation light sources hold the prospect of unprecedented brightness and optical beam quality for a wide range of scientific applications. Many of the proposed new facilities will rely on large superconducting radio frequency (SRF) based linacs to provide high energy, low emittance CW electron beams. For high average power applications there is a growing acceptance of energy recovery linac (ERL) technology as the way to support large recirculating currents with modest RF power requirements. CW SRF and high current ERLs are two core competencies at Jefferson Lab. JLab has designed and built a number of CW cryomodules of several different types starting with the original CEBAF design, with variations for higher current in the two generations of JLab’s free-electron laser (FEL), through two intermediate prototypes to the final high-performance module for the 12 GeV upgrade. Each of these represent fully engineered and tested configurations with a variety of specifications that could be considered for possible use in fourth generation light sources. Furthermore JLab has been actively pursuing advanced concepts for highcurrent high-efficiency cryomodules for next generation ERL based FEL’s. These existing and proposed designs span the range from about 1mA single-pass to over 100 mA energy recovered current capability. Specialized configurations also exist for high-current non-energy recovered sections such as the injector region where very high RF power is required. We discuss the performance parameters of these existing and proposed designs and their suitability to different classes of fourth generation light sources.

  9. A Next Generation Light Source Facility at LBNL

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N.; Austin, B.; Baptiste, K.M.; Byrd, J.M.; Denes, P.; Donahue, R.; Doolittle, L.; Falcone, R.W.; Filippetto, D.; Fournier, S.; Li, D.; Padmore, H.A.; Papadopoulos, C.; Pappas, C.; Penn, G.; Placidi, M.; Prestemon, S.; Prosnitz, D.; Qiang, J.; Ratti, A.; Reinsch, M.; Sannibale, F.; Schlueter, R.; Schoenlein, R.W.; Staples, J.W.; Vecchione, T.; Venturini, M.; Wells, R.; Wilcox, R.; Wurtele, J.; Charman, A.; Kur, E.; Zholents, A.A.

    2011-03-23

    The Next Generation Light Source (NGLS) is a design concept, under development at LBNL, for a multibeamline soft x-ray FEL array powered by a ~;;2 GeV superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. The CW superconducting linear accelerator is supplied by a high-brightness, highrepetition- rate photocathode electron gun. Electron bunches are distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. Individual FELs may be configured for EEHG, HGHG, SASE, or oscillator mode of operation, and will produce high peak and average brightness x-rays with a flexible pulse format, with pulse durations ranging from sub-femtoseconds to hundreds of femtoseconds.

  10. High-performance next-generation EUV lithography light source

    Science.gov (United States)

    Choi, Peter; Zakharov, Sergey V.; Aliaga-Rossel, Raul; Benali, Otman; Duffy, Grainne; Sarroukh, Ouassima; Wyndham, Edmund; Zakharov, Vasily S.

    2009-03-01

    EUVL solution for HVM at the 22 nm node requires a high power long-term EUV source operation with hundreds of watts at the intermediate focus output. EUV mask blank and mask defects inspections require at-wavelength tools with high brightness. Theoretical analysis with a 2-D radiation MHD code Z* has been performed to address key issues in EUV plasma sources with radiation transfer. The study shows that self-absorption defines the limiting brightness of a single EUV source, which cannot meet the requirements of the HVM tool with high efficiency and is not sufficient for critical metrology applications, given the limiting etendue of the optics. It is shown that the required irradiance can be achieved by spatial multiplexing, using multiple small sources. We present here details of the study, as well as experimental results from a novel EUV light source with an intrinsic photon collector demonstrating high brightness, the i-SoCoMo concept, where an impulse micro discharge plasma source is integrated to a photon collector based on an active plasma structure. The small physical size and low etendue properties of the i-SoCoMo unit allows a large number of such sources to be put together in one physical package and be operated in a multiplexed fashion to meet necessary power requirements.

  11. Optical Pumping Experiments on Next Generation Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S J; Fournier, K B; Scott, H; Chung, H K; Lee, R W

    2004-07-29

    Laser-based plasma spectroscopic techniques have been used with great success to determine the line shapes of atomic transitions in plasmas, study the population kinetics of atomic systems embedded in plasmas, and look at the redistribution of radiation. However, the possibilities for optical lasers end for plasmas with n{sub e}>10{sup 22}cm{sup -3} as light propagation is severely altered by the plasma. The construction of the Tesla Test Facility(TTF) at DESY(Deutsche Elektronen-Synchrotron), a short pulse tunable free electron laser in the vacuum-ultraviolet and soft X-ray regime (VUV FEL), based on the SASE(self amplified spontaneous emission) process, will provide a major advance in the capability for dense plasma-related research. This source will provide 10{sup 13} photons in a 200 fs duration pulse that is tunable from {approx} 6nm to 100nm. Since an VUV FEL will not have the limitation associated with optical lasers the entire field of high density plasmas kinetics in laser produced plasma will then be available to study with tunable source. Thus, one will be able to use this and other FEL x-ray sources to pump individual transitions creating enhanced population in the excited states that can easily be monitored. We show two case studies illuminating different aspects of plasma spectroscopy.

  12. Optical Systems for the Fourth Generation Light Source, 4GLS

    CERN Document Server

    Quinn, Frances; MacDonald, Mike; Roper, Mark

    2004-01-01

    4GLS is a multi-user, multi-source facility proposed for construction at Daresbury Laboratory in the UK. By exploiting super-conducting linac technology with energy recovery, it will combine three free electron lasers and a range of conventional synchrotron radiation sources covering the THz to SXR region. The facility will provide femtosecond pulses at high repetition rate, with the FELs delivering GW power in the VUV and XUV region. This paper discusses the options and challenges for the optical systems associated with the suite of photon sources. The beamlines will need to operate both independently and in flexible, synchronised combinations. Together with the requirements for preserving the ultra-bright, fast pulse properties, this places unique demands on the design, layout and operational modes. The paper summarises current technical achievements and identifies the research and development necessary before detailed design of the 4GLS optical systems.

  13. Potential diagnostics for the next-generation light sources

    CERN Document Server

    Lumpkin, Alex H

    1999-01-01

    There is continued interest in developing a diffraction-limited soft or hard X-ray source. Candidate paths include the storage-ring-based free-electron laser (FEL) and the linac-based self-amplified spontaneous emission (SASE) FEL for the two regimes, respectively. As previously discussed, target beam parameters are sigma sub x sub , sub y approx 10 mu m, sigma sub x sub ' sub , sub y sub ' =1 mu rad, and sigma sub t approx 1 ps (0.1 ps for the linac case). We report the use of few- to sub-angstrom radiation emitted by a 7-GeV beam transitting a 198-period diagnostics undulator and a bending magnet to characterize the particle beam. A particle beam divergence as low as sigma sub y sub ' =3.3 mu rad was measured using an X-ray monochromator. Additionally, a particle beam size of sigma sub y <45 mu m and a bunch length of sigma sub t =28 ps with 4-ps resolution were measured using an X-ray pinhole camera with a unique synchroscan and dual-sweep X-ray streak camera as the detector. The adjustable pinhole aper...

  14. Generation of Vector Partially Coherent Optical Sources Using Phase-Only Spatial Light Modulators

    Science.gov (United States)

    Hyde, Milo W.; Bose-Pillai, Santasri; Voelz, David G.; Xiao, Xifeng

    2016-12-01

    A simple and flexible optical system for generating electromagnetic or vector partially coherent sources or beams is presented. The alternative design controls field amplitude (beam shape), coherence, and polarization using only spatial light modulators. This improvement makes the apparatus simpler to construct and significantly increases the flexibility of vector partially coherent source generators by allowing many different types of sources to be produced without changing the physical setup. The system's layout and theoretical foundations are thoroughly discussed. The utility and flexibility of the proposed system are demonstrated by producing a vector Schell-model and non-Schell-model source. The experimental results are compared to theoretical predictions to validate the design. Lastly, design aspects, which must be considered when building a vector partially coherent source generator for a specific application, are discussed.

  15. Advanced Light Source (ALS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Light Source (ALS), a world leader in soft x-ray science, generates light in the wavelengths needed for examining the atomic and electronic structure of...

  16. Propagation characteristics of Bessel beams generated by continuous, incoherent light sources.

    Science.gov (United States)

    Altıngöz, Ceren; Yalızay, Berna; Akturk, Selcuk

    2015-08-01

    We investigate the propagation behavior of Bessel beams generated by incoherent, continuous light sources. We perform experiments with narrowband and broadband light emitting diodes, and, for comparison, with a laser diode. We observe that the formation of Bessel beams is affected minimally by temporal coherence, while spatial coherence determines the longitudinal evolution of the beam profile. With spatially incoherent beams, the fringe contrast is comparable to the coherent case at the beginning of the Bessel zone, while it completely fades away by propagation, turning into a cylindrical light pipe. Our results show that beam shaping methods can be extended to cases of limited spatial coherence, paving the way for potential new uses and applications of such sources.

  17. Generating Picosecond X-Ray Pulses with Beam Manipulation in Synchrotron Light Sources

    CERN Document Server

    Guo, Weiming; Harkay, Katherine C; Sajaev, Vadim; Yang Bing Xin

    2005-01-01

    The length of x-ray pulses generated by storage ring light sources is usually tens of picoseconds. For example, the value is 40 ps rms at the Advanced Photon Source (APS). Methods of x-ray pulse compression are of great interest at the APS. One possible method, per Zholents et al., is to tilt the electron bunch with deflecting rf cavities.* Alternately, we found that the electron bunch can develop a tilt after application of a vertical kick in the presence of nonzero chromaticity. After slicing, the x-ray pulse length is determined by the tilt angle and the vertical beam size. In principal, sub-picosecond pulses can be obtained at APS. To date we have observed 6 ps rms visible light pulses with a streak camera. Efforts are underway to attempt further compression of the x-ray pulse and to increase the brilliance. This method can be easily applied to any storage ring light sources to generate x-ray pulses up to two orders of magnitude shorter than the electron bunch length. In this paper, we will present the th...

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

    Science.gov (United States)

    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 )

  19. Short X-ray pulses from third-generation light sources.

    Science.gov (United States)

    Stepanov, A G; Hauri, C P

    2016-01-01

    High-brightness X-ray radiation produced by third-generation synchrotron light sources (TGLS) has been used for numerous time-resolved investigations in many different scientific fields. The typical time duration of X-ray pulses delivered by these large-scale machines is about 50-100 ps. A growing number of time-resolved studies would benefit from X-ray pulses with two or three orders of magnitude shorter duration. Here, techniques explored in the past for shorter X-ray pulse emission at TGLS are reviewed and the perspective towards the realisation of picosecond and sub-picosecond X-ray pulses are discussed.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  2. Generating picosecond x-ray pulses in synchrotron light sources using dipole kickers

    Directory of Open Access Journals (Sweden)

    W. Guo

    2007-02-01

    Full Text Available The duration of the x-ray pulse generated at a synchrotron light source is typically tens of picoseconds. Shorter pulses are highly desired by the users. In electron storage rings, the vertical beam size is usually orders of magnitude less than the bunch length due to radiation damping; therefore, a shorter pulse can be obtained by slitting the vertically tilted bunch. Zholents proposed tilting the bunch using rf deflection. We found that tilted bunches can also be generated by a dipole magnet kick. A vertical tilt is developed after the kick in the presence of nonzero chromaticity. The tilt was successfully observed and a 4.2-ps pulse was obtained from a 27-ps electron bunch at the Advanced Photon Source. Based on this principle, we propose a short-pulse generation scheme that produces picosecond x-ray pulses at a repetition rate of 1–2 kHz, which can be used for pump-probe experiments.

  3. Review of single particle dynamics for third generation light sources through frequency map analysis

    Directory of Open Access Journals (Sweden)

    L. Nadolski

    2003-11-01

    Full Text Available Frequency map analysis [J. Laskar, Icarus 88, 266 (1990] is used here to analyze the transverse dynamics of four third generation synchrotron light sources: the ALS, the ESRF, the SOLEIL project, and Super-ACO. Time variations of the betatron tunes give additional information for the global dynamics of the beam. The main resonances are revealed; a one-to-one correspondence between the configuration space and the frequency space can be performed. We stress that the frequency maps, and therefore the dynamics optimization, are highly sensitive to sextupolar strengths and vary in a large amount from one machine to another. The frequency maps can thus be used to characterize the different machines.

  4. SESAME -- A third generation synchrotron light source for the Middle East

    Science.gov (United States)

    Winick, Herman

    2012-03-01

    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 centre in construction in Jordan, enabling world-class research while promoting peace through scientific cooperation. Its centerpiece, a new 2.5 GeV 3rd Generation Electron Storage Ring (133m circumference, 26nm-rad emittance, 12 places for insertion devices), will provide intense light from infra-red to hard X-rays. Members of the Council (Bahrain, Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestinian Authority,Turkey) provide the operations budget. Voluntary contributions by several Council Members that could amount to over 20 million over 5 years are now being finalized. This, plus funds from other sources, will enable acquisition of the technical components of the new ring and the upgrading of beamline equipment donated by several European and US labs. All concrete shielding is complete. The 0.8 GeV BESSY I injector system, a gift from Germany, is now being installed. A training program has been underway since 2000. SESAME is on track to start operation with four day-one beam lines in 2015.

  5. Modeling laser produced plasmas with smoothed particle hydrodynamics for next generation advanced light sources

    Science.gov (United States)

    Holladay, Robert; Griffith, Alec; Murillo, Michael S.

    2016-10-01

    A computational model has been developed to study the evolution of a plasma generated by next-generation advanced light sources such as SLAC's LCLS and LANL's proposed MaRIE. Smoothed Particle Hydrodynamics (SPH) is used to model the plasma evolution because of the ease with which it handles the open boundary conditions and large deformations associated with these experiments. Our work extends the basic SPH method by utilizing a two-fluid model of an electron-ion plasma that also incorporates time dependent ionization and recombination by allowing the SPH fluid particles to have an evolving mass based on the mean ionization state of the plasma. Additionally, inter-species heating, thermal conduction, and electric fields are also accounted for. The effects of various initial conditions and model parameters will be presented, with the goal of using this framework to develop a model that can be used in the design and interpretation of future experiments. This work was supported by the Los Alamos National Laboratory Computational Physics Workshop.

  6. A critical experimental test of synchrotron radiation theory with 3rd generation light source

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-05-15

    A recent ''beam splitting'' experiment at LCLS apparently demonstrated that after a microbunched electron beam is kicked on a large angle compared to the divergence of the FEL radiation, the microbunching wave front is readjusted along the new direction of motion of the kicked beam. Therefore, coherent radiation from an undulator placed after the kicker is emitted along the kicked direction without suppression. This strong emission of coherent undulator radiation in the kicked direction cannot be explained in the framework of conventional synchrotron radiation theory. In a previous paper we explained this puzzle. We demonstrated that, in accelerator physics, the coupling of fields and particles is based, on the one hand, on the use of results from particle dynamics treated according to the absolute time convention and, on the other hand, on the use of Maxwell equations treated according to the standard (Einstein) synchronization convention. Here lies the misconception which led to the strong qualitative disagreement between theory and experiment. After the ''beam splitting'' experiment at LCLS, it became clear that the conventional theory of synchrotron radiation cannot ensure the correct description of coherent and spontaneous emission from a kicked electron beam, nor the emission from a beam with finite angular divergence, in an undulator or a bending magnet. However, this result requires further experimental confirmation. In this publication we propose an uncomplicated and inexpensive experiment to test synchrotron radiation theory at 3rd generation light sources.

  7. Generation of 3-D surface maps in waste storage silos using a structured light source

    Science.gov (United States)

    Burks, B. L.; Rowe, J. C.; Dinkins, M. A.; Christensen, B.; Selleck, C.; Jacoboski, D.; Markus, R.

    1992-01-01

    Surface contours inside the large waste storage tanks typical of the Department of Energy (DOE) complex are, in general, highly irregular. In addition to pipes and other pieces of equipment in the tanks, the surfaces may have features such as mounds, fissures, crystalline structures, and mixed solid and liquid forms. Prior to remediation activities, it will be necessary to characterize the waste to determine the most effective remediation approaches. Surface contour data will be required both prior to and during remediation. The use is described of a structured light source to generate 3-D surface contour maps of the interior of waste storage silos at the Feed Materials Production Center at Fernald, OH. The landscape inside these large waste storage tanks bears a strong resemblance to some of the landscapes that might be encountered during lunar or planetary exploration. Hence, these terrestrial 3-D mapping techniques may be directly applicable to extraterrestrial exploration. In further development, it will be demonstrated that these 3-D data can be used for robotic task planning just as 3-D surface contour data of a satellite could be used to plan maintenance tasks for a space-based servicing robot.

  8. Light Beam Generation

    DEFF Research Database (Denmark)

    2007-01-01

    The invention relates to a method and a system for synthesizing a set of controllable light beams by provision of a system for synthesizing a set of light beams, comprising a spatially modulated light source for generation of electromagnetic radiation with a set of replicas of a predetermined......(x-xs, y-ys), a Fourier transforming lens for Fourier transforming the electromagnetic radiation, a first spatial light modulator for phase shifting the Fourier transformed electromagnetic radiation with the phase -F(u, v) of S*, S* is the complex conjugate of the Fourier transformed symbol s, a Fourier...... transforming lens for Inverse Fourier transforming the spatially modulated radiation, whereby a set of light beams are formed propagating through the inverse Fourier plane (x', y') at desired positions (x's, y's), and a controller for controlling the position of a replica of the symbol, s, for movement...

  9. Two-photon bioimaging utilizing supercontinuum light generated by a high-peak-power picosecond semiconductor laser source.

    Science.gov (United States)

    Yokoyama, Hiroyuki; Tsubokawa, Hiroshi; Guo, Hengchang; Shikata, Jun-ichi; Sato, Ki-ichi; Takashima, Keijiro; Kashiwagi, Kaori; Saito, Naoaki; Taniguchi, Hirokazu; Ito, Hiromasa

    2007-01-01

    We developed a novel scheme for two-photon fluorescence bioimaging. We generated supercontinuum (SC) light at wavelengths of 600 to 1200 nm with 774-nm light pulses from a compact turn-key semiconductor laser picosecond light pulse source that we developed. The supercontinuum light was sliced at around 1030- and 920-nm wavelengths and was amplified to kW-peak-power level using laboratory-made low-nonlinear-effects optical fiber amplifiers. We successfully demonstrated two-photon fluorescence bioimaging of mouse brain neurons containing green fluorescent protein (GFP).

  10. Light Sources and Lighting Circuits

    Science.gov (United States)

    Honda, Hisashi; Suwa, Takumi; Yasuda, Takeo; Ohtani, Yoshihiko; Maehara, Akiyoshi; Okada, Atsunori; Komatsu, Naoki; Mannami, Tomoaki

    means of using filler gas with a higher atomic weight. Regarding fluorescent lamps, studies and developments for longer operating life and improvement in the lumen maintenance factor for the straight-type and circular-type fluorescent lamps were actively pursued. Regarding self-ballasted fluorescent lamps, the main stream of development was aimed at reducing lamp size and increasing energy conservation, and the development of new products that took advantage of these features proceeded. In regard to LED light sources, basic research and product development, including new application development, were vigorously implemented. In basic research, studies were reported, not only on efficacy improvements through optimization of the LED chips, phosphor layers, and packaging technology, but also on photometry, colorimetry, and visual psychology. In the field of application, applications were studied for general lighting sources and also for a wide range of fields, such as automotive headlights and visible light communication. Also, many academic conferences and exhibitions were held domestically and overseas, and the high level of interest suggests high expectations for this next-generation light source. Regarding HID lamps, there was much activity in research and development and in the commercialization of the ceramic metal halide lamp product, and products were commercialized with features such as higher efficiency (130 lm/W) and higher color rendering properties (R9 ≥ 90). In the high-pressure sodium lamps, there were many study reports concerning plant growth and insect pest control using its low insect-attracting characteristics. With high-pressure mercury lamps, there were many reports on reducing lamp size and increasing intensity for use as a light source for projectors.

  11. Femtosecond timing distribution and control for next generation accelerators and light sources

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Li -Jin [Idesta Quantum Electronics, LLC, Newton, NJ (United States)

    2014-03-31

    Femtosecond Timing Distribution At LCLS Free-electron-lasers (FEL) have the capability of producing high photon flux from the IR to the hard x-ray wavelength range and to emit femtosecond and eventually even attosecond pulses. This makes them an ideal tool for fundamental as well as applied re-search. Timing precision at the Stanford Linear Coherent Light Source (LCLS) between the x-ray FEL (XFEL) and ultrafast optical lasers is currently no better than 100 fs RMS. Ideally this precision should be much better and could be limited only by the x-ray pulse duration, which can be as short as a few femtoseconds. An increasing variety of science problems involving electron and nuclear dynamics in chemical and material systems will become accessible as the timing improves to a few femtoseconds. Advanced methods of electron beam conditioning or pulse injection could allow the FEL to achieve pulse durations less than one femtosecond. The objective of the work described in this proposal is to set up an optical timing distribution system based on mode locked Erbium doped fiber lasers at LCLS facility to improve the timing precision in the facility and allow time stamping with a 10 fs precision. The primary commercial applications for optical timing distributions systems are seen in the worldwide accelerator facilities and next generation light sources community. It is reasonable to expect that at least three major XFELs will be built in the next decade. In addition there will be up to 10 smaller machines, such as FERMI in Italy and Maxlab in Sweden, plus the market for upgrading already existing facilities like Jefferson Lab. The total market is estimated to be on the order of a 100 Million US Dollars. The company owns the exclusive rights to the IP covering the technology enabling sub-10 fs synchronization systems. Testing this technology, which has set records in a lab environment, at LCLS, hence in a real world scenario, is an important corner stone of bringing the

  12. FEMTOSECOND TIMING DISTRIBUTION AND CONTROL FOR NEXT GENERATION ACCELERATORS AND LIGHT SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Li-Jin [Idesta Quantum Electronics, LLC

    2014-03-31

    Femtosecond Timing Distribution At LCLS Free-electron-lasers (FEL) have the capability of producing high photon flux from the IR to the hard x-ray wavelength range and to emit femtosecond and eventually even at-tosecond pulses. This makes them an ideal tool for fundamental as well as applied re-search. Timing precision at the Stanford Linear Coherent Light Source (LCLS) between the x-ray FEL (XFEL) and ultrafast optical lasers is currently no better than 100 fs RMS. Ideally this precision should be much better and could be limited only by the x-ray pulse duration, which can be as short as a few femtoseconds. An increasing variety of science problems involving electron and nuclear dynamics in chemical and material systems will become accessible as the timing improves to a few femtoseconds. Advanced methods of electron beam conditioning or pulse injection could allow the FEL to achieve pulse durations less than one femtosecond. The objec-tive of the work described in this proposal is to set up an optical timing distribution sys-tem based on modelocked Erbium doped fiber lasers at LCLS facility to improve the timing precision in the facility and allow time stamping with a 10 fs precision. The primary commercial applications for optical timing distributions systems are seen in the worldwide accelerator facilities and next generation light sources community. It is reasonable to expect that at least three major XFELs will be built in the next decade. In addition there will be up to 10 smaller machines, such as FERMI in Italy and Maxlab in Sweden, plus the market for upgrading already existing facilities like Jefferson Lab. The total market is estimated to be on the order of a 100 Million US Dollars. The company owns the exclusive rights to the IP covering the technology enabling sub-10 fs synchronization systems. Testing this technology, which has set records in a lab environment, at LCLS, hence in a real world scenario, is an important corner stone of bringing the

  13. Total radiated power, infrared output, and heat generation by cold light sources at the distal end of endoscopes and fiber optic bundle of light cables.

    Science.gov (United States)

    Hensman, C; Hanna, G B; Drew, T; Moseley, H; Cuschieri, A

    1998-04-01

    Skin burns and ignition of drapes have been reported with the use of cold light sources. The aim of the study was to document the temperature generated by cold light sources and to correlate this with the total radiated power and infrared output. The temperature, total radiated power, and infrared output were measured as a function of time at the end of the endoscope (which is inserted into the operative field) and the end of the fiber optic bundle of the light cable (which connects the cable to the light port of the endoscope) using halogen and xenon light sources. The highest temperature recorded at the end of the endoscope was 95 degrees C. The temperature measured at the optical fiber location of the endoscope was higher than at its lens surface (p cables, the temperature reached 225 degrees C within 15 s. The temperature recorded at the optical fiber location of all endoscopes and light cables studied rose significantly over a period of 10 min to reach its maximum (p power. High temperatures are reached by 10 min at the end of fiber optic bundle of light cables and endoscopes with both halogen and xenon light sources. This heat generation is largely due to the radiated power in the visible light spectrum.

  14. Innovative Development of Next Generation and Energy Efficient Solid State Light Sources for General Illumination

    Energy Technology Data Exchange (ETDEWEB)

    Ian Ferguson

    2006-07-31

    This two year program resulted in a novel broadband spectrally dynamic solid state illumination source (BSDLED) that uses a dual wavelength light emitting diode (LED) and combinations of phosphors to create a broadband emission that is real-time controllable. Four major focuses of this work were as follows: (1) creation of a two terminal dual wavelength LED with control of the relative intensities of the two emission peaks, (2) bandgap modeling of the two terminal dual LED to explain operation based on the doping profile, (3) novel use of phosphor combinations with dual LEDs to create a broadband spectral power distribution that can be varied to mimic a blackbody radiator over a certain range and (4) investigation of novel doping schemes to create tunnel junctions or equivalent buried current spreading layers in the III-nitrides. Advances were achieved in each of these four areas which could lead to more efficient solid state light sources with greater functionality over existing devices. The two-terminal BSDLED is an important innovation for the solid-state lighting industry as a variable spectrum source. A three-terminal dual emitter was also investigated and appears to be the most viable approach for future spectrally dynamic solid state lighting sources. However, at this time reabsorption of emission between the two active regions limits the usefulness of this device for illumination applications.

  15. Injector Beam Dynamics for a High-Repetition Rate 4th-Generation Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulos, C. F.; Corlett, J.; Emma, P.; Filippetto, D.; Penn, G.; Qiang, J.; Reinsch, M.; Sannibale, F.; Steier, C.; Venturini, M.; Wells, R.

    2013-05-20

    We report on the beam dynamics studies and optimization methods for a high repetition rate (1 MHz) photoinjector based on a VHF normal conducting electron source. The simultaneous goals of beamcompression and reservation of 6-dimensional beam brightness have to be achieved in the injector, in order to accommodate a linac driven FEL light source. For this, a parallel, multiobjective optimization algorithm is used. We discuss the relative merits of different injector design points, as well as the constraints imposed on the beam dynamics by technical considerations such as the high repetition rate.

  16. A laboratory model of post-Newtonian gravity with high power lasers and 4th generation light sources

    Science.gov (United States)

    Gregori, G.; Levy, M. C.; Wadud, M. A.; Crowley, B. J. B.; Bingham, R.

    2016-04-01

    Using the post-Newtonian formalism of gravity, we attempt to calculate the x-ray Thomson scattering cross section of electrons that are accelerated in the field of a high intensity optical laser. We show that our results are consistent with previous calculations, suggesting that the combination of high power laser and 4th generation light sources may become a powerful platform to test models exploring high order corrections to the Newtonian gravity.

  17. BEAM DYNAMICS STUDIES OF A HIGH-REPETITION RATE LINAC-DRIVER FOR A 4TH GENERATION LIGHT SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Ventturini, M.; Corlett, J.; Emma, P.; Papadopoulos, C.; Penn, G.; Placidi, M.; Qiang, J.; Reinsch, M.; Sannibale, F.; Steier, C.; Sun, C.; Wells, R.

    2012-05-18

    We present recent progress toward the design of a super-conducting linac driver for a high-repetition rate FEL-based soft x-ray light source. The machine is designed to accept beams generated by the APEX photo-cathode gun operating with MHz-range repetition rate and deliver them to an array of SASE and seeded FEL beamlines. We review the current baseline design and report results of beam dynamics studies.

  18. Testing quantum mechanics in non-Minkowski space-time with high power lasers and 4th generation light sources

    Science.gov (United States)

    Crowley, B. J. B.; Bingham, R.; Evans, R. G.; Gericke, D. O.; Landen, O. L.; Murphy, C. D.; Norreys, P. A.; Rose, S. J.; Tschentscher, Th; Wang, C. H.-T.; Wark, J. S.; Gregori, G.

    2012-07-01

    A common misperception of quantum gravity is that it requires accessing energies up to the Planck scale of 1019 GeV, which is unattainable from any conceivable particle collider. Thanks to the development of ultra-high intensity optical lasers, very large accelerations can be now the reached at their focal spot, thus mimicking, by virtue of the equivalence principle, a non Minkowski space-time. Here we derive a semiclassical extension of quantum mechanics that applies to different metrics, but under the assumption of weak gravity. We use our results to show that Thomson scattering of photons by uniformly accelerated electrons predicts an observable effect depending upon acceleration and local metric. In the laboratory frame, a broadening of the Thomson scattered x ray light from a fourth generation light source can be used to detect the modification of the metric associated to electrons accelerated in the field of a high power optical laser.

  19. A N2 Plasma Light Source Generated in Hollow Cathode Discharge and Its Application in Lithographic Plate Making

    Institute of Scientific and Technical Information of China (English)

    LI Chao-yang; CHEN Qiang; ZHANG Guang-qiu

    2007-01-01

    Computer to conventional plate (CTCP) technology is getting more and more attention in printing industries.In this paper we report a nitrogen plasma light source generated in hollow cathode discharge (HCD),which is used for pre-sensitivity (PS) plate exposure.The N2 molecule emits abundant spectrum ranging from 350 nm to 460 nm.With the voltage of 580 V,current of 1.8 A and pressure of 70 Pa in the discharge an optical power density of 0.46 mW/cm2 is obtained.The optical power density could be further increased with optimizing the lens system.The phototonus efficiency of this source is discussed in detail based upon the chemical principle and the FTIR analysis on the coating material.

  20. Thermoelectricity Light Sources

    Institute of Scientific and Technical Information of China (English)

    SHIYongji

    1997-01-01

    A thermoelectricity light source in a gaseous plasma discharge between two electrodes is described,one of which emits electrons thermoionically.The analytical model describing basic physical phenomena is developed.The results are excellent agreement with simulated test.

  1. NbC/Si multilayer mirror for next generation EUV light sources.

    Science.gov (United States)

    Modi, Mohammed H; Rai, S K; Idir, Mourad; Schaefers, F; Lodha, G S

    2012-07-02

    In the present study we report a new multilayer combination comprised of refracting layers of niobium carbide and spacer layers of silicon as a more stable and high reflecting combination for the 10 - 20 nm wavelength region. The reflectivity of the new combination is comparable to Mo/Si conventional mirrors. Annealing experiments carried out with NbC/Si multilayer at 600°C temperature showed a ~2.5% drop in the soft x-ray reflectivity along with a marginal contraction in the multilayer period length. The multilayer structure is found stable after the heat treatment. Crystallization of the niobium carbide and silicon layers is responsible for the compaction in the period length as revealed by the grazing incidence x-ray diffraction measurements. No signature of silicide formation or any other chemical species could be detected. The multilayer structures were grown by ion beam sputtering technique using a compound target of niobium carbide. Soft x-ray reflectivity measurements performed at the Indus-1 and BESSY-II synchrotron radiation sources are found in good agreement with the simulations.

  2. Vertically polarizing undulator with the dynamic compensation of magnetic forces for the next generation of light sources.

    Science.gov (United States)

    Strelnikov, N; Trakhtenberg, E; Vasserman, I; Xu, J; Gluskin, E

    2014-11-01

    A short prototype (847-mm-long) of an Insertion Device (ID) with the dynamic compensation of ID magnetic forces has been designed, built, and tested at the Advanced Photon Source (APS) of the Argonne National Laboratory. The ID magnetic forces were compensated by the set of conical springs placed along the ID strongback. Well-controlled exponential characteristics of conical springs permitted a very close fit to the ID magnetic forces. Several effects related to the imperfections of actual springs, their mounting and tuning, and how these factors affect the prototype performance has been studied. Finally, series of tests to determine the accuracy and reproducibility of the ID magnetic gap settings have been carried out. Based on the magnetic measurements of the ID Beff, it has been demonstrated that the magnetic gaps within an operating range were controlled accurately and reproducibly within ±1 μm. Successful tests of this ID prototype led to the design of a 3-m long device based on the same concept. The 3-m long prototype is currently under construction. It represents R&D efforts by the APS toward APS Upgrade Project goals as well as the future generation of IDs for the Linac Coherent Light Source (LCLS).

  3. Solving X-ray protein structures without a crystal: using X-ray Free Electron Laser, the fourth generation synchrotron light sources

    Institute of Scientific and Technical Information of China (English)

    Bo Huang

    2010-01-01

    @@ A synchrotron light source is a source of electromagnetic radiation artificially produced by specialized electron accelerators. Compared to the commonly used in-house X-ray sources, it is wavelength adjustable, much stronger and more focused. In the last two decades, synchrotron usage has become the mainstream for X-ray protein structure determination. Taking the advantage of micro-focus light beams of the third generation synchrotron, the size of a usable protein crystal for data collection decreases to micron level, which increases the rate of macromolecular structure determination to about 10 new protein data bank entries per day.

  4. Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Sah, R.C.

    1983-03-01

    The Advanced Light Source (ALS) is a new synchrotron radiation source which has been proposed by Lawrence Berkeley Laboratory. The ALS will be a key component in a major new research facility, the National Center for Advanced Materials. The ALS will consist of an electron linear accelerator, a booster synchrotron, a 1.3-GeV electron storage ring, and a number of photon beam lines. Most or all photon beam lines will originate from wiggler and undulator magnets placed in the 12 long straight sections of the ALS. A very low electron beam emittance will provide photon beams of unsurpassed spectral brilliance from specially-designed undulators, and a high radiofrequency will produce very short pulse lengths.

  5. Next Generation Light Robotics

    DEFF Research Database (Denmark)

    Glückstad, Jesper

    potential of this new ‘drone-like’ light-printed, light-driven, light-actuated micro- and nano-robotics in challenging geometries requires a versatile and real-time reconfigurable light addressing that can dynamically track a plurality of tiny tools in 3D to ensure real-time continuous light...

  6. Radio lighting based on dynamic chaos generators

    CERN Document Server

    Dmitriev, Alexander; Gerasimov, Mark; Itskov, Vadim

    2016-01-01

    A problem of lighting objects and surfaces with artificial sources of noncoherent microwave radiation with the aim to observe them using radiometric equipment is considered. Transmitters based on dynamic chaos generators are used as sources of noncoherent wideband microwave radiation. An experimental sample of such a device, i.e., a radio lighting lamp based on a chaos microgenerator and its performance are presented.

  7. Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source

    Science.gov (United States)

    2016-11-29

    GRANT NUMBER FA9550-15-1-0272 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr . Jerome V. Moloney, Professor of Optical Sciences University of Arizona...afosr.reports.sgizmo.com/s3/> Subject: Final Report to Dr . Arje Nachman Contract/Grant Title: Long Wavelength Electromagnetic Light Bullets Generated by a 10.6...kilometer ranges. Our in- house ultrashort pulse simulation tool was used to provide basic research support for studying atmospheric propagation of a

  8. Nitride quantum light sources

    Science.gov (United States)

    Zhu, T.; Oliver, R. A.

    2016-02-01

    Prototype nitride quantum light sources, particularly single-photon emitters, have been successfully demonstrated, despite the challenges inherent in this complex materials system. The large band offsets available between different nitride alloys have allowed device operation at easily accessible temperatures. A wide range of approaches has been explored: not only self-assembled quantum dot growth but also lithographic methods for site-controlled nanostructure formation. All these approaches face common challenges, particularly strong background signals which contaminate the single-photon stream and excessive spectral diffusion of the quantum dot emission wavelength. If these challenges can be successfully overcome, then ongoing rapid progress in the conventional III-V semiconductors provides a roadmap for future progress in the nitrides.

  9. Swiss Light Source SLS

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-09-01

    The Paul Scherrer Institute has begun work on the implementation of the Swiss Synchrotron Light Source (SLS). The construction of this facility, which will have international scope, is intended to provide a national focus for co-operation between various disciplines and for research in material sciences. Although basic research in physics and chemistry, biology, medicine and environmental sciences would seem to be in the foreground, industrial users also have an interest in the SLS. At present, this mainly centres on investigations into the structure of biological and chemical molecules, the use of high-performance methods of analysis, and the manufacture and investigation of microstructures. SLS is planned to be taken into service with an initial experimental installation by the middle of 2001. In this brochure an overview is presented on the main characteristics of the SLS facility and on its significance as a tool for interdisciplinary research.

  10. A compact, coherent light source system architecture

    Science.gov (United States)

    Biedron, S. G.; Dattoli, G.; DiPalma, E.; Einstein, J.; Milton, S. V.; Petrillo, V.; Rau, J. V.; Sabia, E.; Spassovsky, I. P.; van der Slot, P. J. M.

    2016-09-01

    Our team has been examining several architectures for short-wavelength, coherent light sources. We are presently exploring the use and role of advanced, high-peak power lasers for both accelerating the electrons and generating a compact light source with the same laser. Our overall goal is to devise light sources that are more accessible by industry and in smaller laboratory settings. Although we cannot and do not want to compete directly with sources such as third-generation light sources or that of national-laboratory-based free-electron lasers, we have several interesting schemes that could bring useful and more coherent, short-wavelength light source to more researchers. Here, we present and discuss several results of recent simulations and our future steps for such dissemination.

  11. Linac-augmented light sources an incremental concept for enhancing the capabilities of existing 3rd-generation storage rings.

    CERN Document Server

    Lewellen, J W

    2003-01-01

    Planned and proposed 4th-generation x-ray sources, such as energy-recovery linacs (ERLs) and single-pass x-ray free-electron lasers (X-FELs) offer a number of potential advantages, including small source size, higher peak brightness, ultrashort pulses, and potentially temporally and transversely coherent pulses. While offering unique capabilities, such facilities will also offer several important limitations, including limited numbers of user beamlines (for FELs) and a pulse-repetition rate that may be too high for many dynamics experiments (ERLs). In addition, there are many technical challenges associated with both types of facilities. A third type of facility, exemplified by the Short Pulse Photon Source (SPPS) at SLAC [1], would support neither a large number of users simultaneously nor generate coherent pulses, but would generate very intense, short x-ray pulses. Such a facility could serve as the starting point for either an ERL or an X-FEL, or a combined, hybrid machine. For the foreseeable future, how...

  12. Increasing the brightness of light sources

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Ling

    2006-11-16

    In this work the principle of light recycling is applied to artificial light sources in order to achieve brightness enhancement. Firstly, the feasibilities of increasing the brightness of light sources via light recycling are examined theoretically, based on the fundamental laws of thermodynamics including Kirchhoff's law on radiation, Planck's law, Lambert-Beer's law, the etendue conservation and the brightness theorem. From an experimental viewpoint, the radiation properties of three different kinds of light sources including short-arc lamps, incandescent lamps and LEDs characterized by their light-generating mechanisms are investigated. These three types of sources are used in light recycling experiments, for the purpose of 1. validating the intrinsic light recycling effect in light sources, e. g. the intrinsic light recycling effect in incandescent lamps stemming from the coiled filament structure. 2. acquiring the required parameters for establishing physical models, e.g. the emissivity/absorptivity of the short-arc lamps, the intrinsic reflectivity and the external quantum efficiency of LEDs. 3. laying the foundations for designing optics aimed at brightness enhancement according to the characteristics of the sources and applications. Based on the fundamental laws and experiments, two physical models for simulating the radiance distribution of light sources are established, one for thermal filament lamps, the other for luminescent sources, LEDs. As validation of the theoretical and experimental investigation of the light recycling effect, an optical device, the Carambola, is designed for achieving deterministic and multiple light recycling. The Carambola has the function of a concentrator. In order to achieve the maximum possible brightness enhancement with the Carambola, several combinations of sources and Carambolas are modelled in ray-tracing simulations. Sources with different light-emitting mechanisms and different radiation properties

  13. 热光源产生贝塞尔光束的理论与实验%Theory and Experiment of Bessel Beam Generated by Thermal Light Source

    Institute of Scientific and Technical Information of China (English)

    程治明; 吴逢铁; 郑维涛; 张前安; 范丹丹

    2012-01-01

    Bessel-like beam is generated by using thermal light source. The incident condition for the light waves with multi-wavelength passing through axicon simultaneously is analyzed and simulated. The results show that Bessel beam can be generated behind the axicon, but the contrast of the cross section light intensity drops because of the incoherent superposition of the multi-wavelength light waves. In our experiment, halogen light cup is used as thermal light source for generating Bessel beam. A set of optical system is designed to improve the spatial coherence of the light waves, and the Besse!-!ike beam is generated after the light waves passing the axicon. Comparing the experimental result with the numerical simulation, it is found that Bessel beam obtained from experiment is basically in accord with the numerical calculation. Besides the maximum diffraction-free distance is shorter in the experiment, which is analyzed at the end of the paper.%利用热光源获得了近似贝塞尔光束.对多波长光波同时入射轴棱锥的情形进行分析和数值模拟,结果显示轴棱锥后会形成近似贝塞尔光束,但受光场非相干叠加的影响截面光强对比度降低.实验采用卤素灯杯作为产生贝塞尔光束的热光源,针对热光源相干性差的特点设计出一套光学系统,提高光波的空间相干性,再使光波平行透过轴棱锥得到了近似贝塞尔光束.将实验结果与数值计算对比,发现实验所得贝塞尔光束的特性与理论基本吻合,但最大无衍射距离较理论计算所得的短,并对此进行了分析.

  14. Influence of the electrode wear on the EUV generation of a discharge based extreme ultraviolet light source

    Science.gov (United States)

    Vieker, Jochen; Bergmann, Klaus

    2017-08-01

    Reliability and a long maintenance interval are major requirements for the industrial use of an extreme ultraviolet (EUV) source. In this paper we present results on the influence of the electrode erosion on the EUV generation and its lifetime limiting characteristics. The geometry of the electrodes and their influence on the gas pressure distribution within the electrode system have been found to be the key variables to characterize the regime of operation. This better understanding allows for an optimization of device parameters (e.g. gas flow or pulse energy) to counteract the erosion process, in order to increase the maintenance interval and EUV output. The EUV source under investigation is based on a hollow cathode triggered pinch plasma. A new trigger concept is introduced that enables free adjustment of the gas pressure during operation, thus enabling the operation with a high conversion efficiency of up to  >0.7 %/2πsr at 13.5 nm and 2% bandwidth. The efficiency for the peak brilliance is up to ~2.6 W kW-1 mm-2sr-1 while the maximum electrical input power of the system is 15 kW.

  15. Casimir light: the source.

    OpenAIRE

    1993-01-01

    The release of Casimir energy in filling a dielectric hole is identified as the source of coherent sonoluminescence. Qualitative agreement with recently acquired data is found for the magnitude and shape of the spectrum.

  16. Intermediate-energy light sources

    CERN Document Server

    Corbett, W

    2003-01-01

    Increasingly, atomic scale information underlies scientific and technological progress in disciplines ranging from pharmaceutical development to materials synthesis to environmental remediation. While a variety of research tools are used to provide atomic scale information, synchrotron radiation has proved invaluable in this quest. The rapid growth of soft- and hard X-ray synchrotron light sources stands as stark testimony to the importance and utility of synchrotron radiation. Starting from just a handful of synchrotron light sources in the early 1970s, this burgeoning field now includes over 70 proposed, in-construction, or operating facilities in 23 countries on five continents. Along the way, synchrotron light facilities have evolved from small laboratories extracting light parasitically from storage rings designed for high-energy physics research to large, dedicated sources using the latest technology to produce extraordinarily bright photon beams. The basic layout of a multi-GeV storage ring light sourc...

  17. Long-pulse Supercontinuum Light Sources

    DEFF Research Database (Denmark)

    Moselund, Peter M.

    A Supercontinuum (SC) is a broad spectrum generated from a narrow light source through non-linear effects. This thesis describes SC generation based on 1064 nm ps pulses in PCF fibres. We investigate how the SC spectrum can be modified and intensity noise reduced by feeding back part of the SC...

  18. Diamond Light Source: status and perspectives

    OpenAIRE

    Materlik, Gerhard; Rayment, Trevor; Stuart, David I.

    2015-01-01

    Diamond Light Source, a third-generation synchrotron radiation (SR) facility in the UK, celebrated its 10th anniversary in 2012. A private limited company was set up in April 2002 to plan, construct and operate the new user-oriented SR facility, called in brief Diamond. It succeeded the Synchrotron Radiation Source in Daresbury, a second-generation synchrotron that opened in 1980 as the world's first dedicated X-ray-providing facility, closing finally in 2008, by which time Diamond's accelera...

  19. Compact synchrotron light sources

    CERN Document Server

    Weihreter, Ernst

    1996-01-01

    This book covers a new niche in circular accelerator design, motivated by the promising industrial prospects of recent micromanufacturing methods - X-ray lithography, synchrotron radiation-based micromachining and microanalysis techniques. It describes the basic concepts and the essential challenges for the development of compact synchrotron radiation sources from an accelerator designer's point of view and gives an outline of the actual state of the art. The volume is intended as an introduction and as a reference for physicists, engineers and managers involved in this rapidly developing fiel

  20. Light source modeling for automotive lighting devices

    Science.gov (United States)

    Zerhau-Dreihoefer, Harald; Haack, Uwe; Weber, Thomas; Wendt, Dierk

    2002-08-01

    Automotive lighting devices generally have to meet high standards. For example to avoid discomfort glare for the oncoming traffic, luminous intensities of a low beam headlight must decrease by more than one order of magnitude within a fraction of a degree along the horizontal cutoff-line. At the same time, a comfortable homogeneous illumination of the road requires slowly varying luminous intensities below the cutoff line. All this has to be realized taking into account both, the legal requirements and the customer's stylistic specifications. In order to be able to simulate and optimize devices with a good optical performance different light source models are required. In the early stage of e.g. reflector development simple unstructured models allow a very fast development of the reflectors shape. On the other hand the final simulation of a complex headlamp or signal light requires a sophisticated model of the spectral luminance. In addition to theoretical models based on the light source's geometry, measured luminance data can also be used in the simulation and optimization process.

  1. Potential of the FLASH FEL technology for the construction of a kW-scale light source for the next generation lithography

    Energy Technology Data Exchange (ETDEWEB)

    Schneidmiller, E.A.; Vogel, V.F.; Weise, H.; Yurkov, M.V.

    2011-08-15

    The driving engine of the Free Electron Laser in Hamburg (FLASH) is an L-band superconducting accelerator. It is designed to operate in burst mode with 800 microsecond pulse duration at a repetition rate of 10 Hz. The maximum accelerated beam current during the macropulse is 9 mA. Our analysis shows that the FLASH technology has great potential since it is possible to construct a FLASH like free electron laser operating at the wavelength of 13.5 and 6.8 nanometer with an average power up to 2.6 kW. Such a source meets the physical requirements for the light source for the next generation lithography. (orig.)

  2. Advanced Light Source control system

    Energy Technology Data Exchange (ETDEWEB)

    Magyary, S.; Chin, M.; Cork, C.; Fahmie, M.; Lancaster, H.; Molinari, P.; Ritchie, A.; Robb, A.; Timossi, C.

    1989-03-01

    The Advanced Light Source (ALS) is a third generation 1--2 GeV synchrotron radiation source designed to provide ports for 60 beamlines. It uses a 50 MeV electron linac and 1.5 GeV, 1 Hz, booster synchrotron for injection into a 1--2 GeV storage ring. Interesting control problems are created because of the need for dynamic closed beam orbit control to eliminate interaction between the ring tuning requirements and to minimize orbit shifts due to ground vibrations. The extremely signal sensitive nature of the experiments requires special attention to the sources of electrical noise. These requirements have led to a control system design which emphasizes connectivity at the accelerator equipment end and a large I/O bandwidth for closed loop system response. Not overlooked are user friendliness, operator response time, modeling, and expert system provisions. Portable consoles are used for local operation of machine equipment. Our solution is a massively parallel system with >120 Mbits/sec I/O bandwidth and >1500 Mips computing power. At the equipment level connections are made using over 600 powerful Intelligent Local Controllers (ILC-s) mounted in 3U size Eurocard slots using fiber-optic cables between rack locations. In the control room, personal computers control and display all machine variables at a 10 Hz rate including the scope signals which are collected though the control system. Commercially available software and industry standards are used extensively. Particular attention is paid to reliability, maintainability and upgradeability. 10 refs., 11 figs.

  3. Nanograting-based compact VUV spectrometer and beam profiler for in-situ characterization of high-order harmonic generation light sources

    Energy Technology Data Exchange (ETDEWEB)

    Kornilov, Oleg; Wilcox, Russell; Gessner, Oliver

    2010-07-09

    A compact, versatile device for VUV beam characterization is presented. It combines the functionalities of a VUV spectrometer and a VUV beam profiler in one unit and is entirely supported by a standard DN200 CF flange. The spectrometer employs a silicon nitride transmission nanograting in combination with a micro-channel plate based imaging detector. This enables the simultaneous recording of wavelengths ranging from 10 nm to 80 nm with a resolution of 0.25 nm to 0.13 nm. Spatial beam profiles with diameters up to 10 mm are imaged with 0.1 mm resolution. The setup is equipped with an in-vacuum translation stage that allows for in situ switching between the spectrometer and beam profiler modes and for moving the setup out of the beam. The simple, robust design of the device is well suited for non-intrusive routine characterization of emerging laboratory- and accelerator-based VUV light sources. Operation of the device is demonstrated by characterizing the output of a femtosecond high-order harmonic generation light source.

  4. Nanograting-based compact vacuum ultraviolet spectrometer and beam profiler for in situ characterization of high-order harmonic generation light sources.

    Science.gov (United States)

    Kornilov, Oleg; Wilcox, Russell; Gessner, Oliver

    2010-06-01

    A compact, versatile device for vacuum ultraviolet (VUV) beam characterization is presented. It combines the functionalities of a VUV spectrometer and a VUV beam profiler in one unit and is entirely supported by a standard DN200 CF flange. The spectrometer employs a silicon nitride transmission nanograting in combination with a microchannel plate-based imaging detector. This enables the simultaneous recording of wavelengths ranging from 10 to 80 nm with a resolution of 0.25-0.13 nm. Spatial beam profiles with diameters up to 10 mm are imaged with 0.1 mm resolution. The setup is equipped with an in-vacuum translation stage that allows for in situ switching between the spectrometer and beam profiler modes and for moving the setup out of the beam. The simple, robust design of the device is well suited for nonintrusive routine characterization of emerging laboratory- and accelerator-based VUV light sources. Operation of the device is demonstrated by characterizing the output of a femtosecond high-order harmonic generation light source.

  5. Start-to-end simulation of x-ray radiation of a next generation light source using the real number of electrons

    Directory of Open Access Journals (Sweden)

    J. Qiang

    2014-03-01

    Full Text Available In this paper we report on start-to-end simulation of a next generation light source based on a high repetition rate free electron laser (FEL driven by a CW superconducting linac. The simulation integrated the entire system in a seamless start-to-end model, including birth of photoelectrons, transport of electron beam through 600 m of the accelerator beam delivery system, and generation of coherent x-ray radiation in a two-stage self-seeding undulator beam line. The entire simulation used the real number of electrons (∼2 billion electrons/bunch to capture the details of the physical shot noise without resorting to artificial filtering to suppress numerical noise. The simulation results shed light on several issues including the importance of space-charge effects near the laser heater and the reliability of x-ray radiation power predictions when using a smaller number of simulation particles. The results show that the microbunching instability in the linac can be controlled with 15 keV uncorrelated energy spread induced by a laser heater and demonstrate that high brightness and flux 1 nm x-ray radiation (∼10^{12}  photons/pulse with fully spatial and temporal coherence is achievable.

  6. Start-to-end simulation of x-ray radiation of a next generation light source using the real number of electrons

    Science.gov (United States)

    Qiang, J.; Corlett, J.; Mitchell, C. E.; Papadopoulos, C. F.; Penn, G.; Placidi, M.; Reinsch, M.; Ryne, R. D.; Sannibale, F.; Sun, C.; Venturini, M.; Emma, P.; Reiche, S.

    2014-03-01

    In this paper we report on start-to-end simulation of a next generation light source based on a high repetition rate free electron laser (FEL) driven by a CW superconducting linac. The simulation integrated the entire system in a seamless start-to-end model, including birth of photoelectrons, transport of electron beam through 600 m of the accelerator beam delivery system, and generation of coherent x-ray radiation in a two-stage self-seeding undulator beam line. The entire simulation used the real number of electrons (˜2 billion electrons/bunch) to capture the details of the physical shot noise without resorting to artificial filtering to suppress numerical noise. The simulation results shed light on several issues including the importance of space-charge effects near the laser heater and the reliability of x-ray radiation power predictions when using a smaller number of simulation particles. The results show that the microbunching instability in the linac can be controlled with 15 keV uncorrelated energy spread induced by a laser heater and demonstrate that high brightness and flux 1 nm x-ray radiation (˜1012 photons/pulse) with fully spatial and temporal coherence is achievable.

  7. EDITORIAL: LED light sources (light for the future) LED light sources (light for the future)

    Science.gov (United States)

    Grandjean, N.

    2010-09-01

    Generating white light from electricity with maximum efficacy has been a long quest since the first incandescent lamp was invented by Edison at the end of the 19th century. Nowadays, semiconductors are making reality the holy grail of converting electrons into photons with 100% efficiency and with colours that can be mixed for white light illumination. The revolution in solid-state lighting (SSL) dates to 1994 when Nakamura reported the first high-brightness blue LED based on GaN semiconductors. Then, white light was produced by simply combining a blue dye with a yellow phosphor. After more than a decade of intensive research the performance of white LEDs is quite impressive, beating by far the luminous efficacy of compact fluorescent lamps. We are likely close to replacing our current lighting devices by SSL lamps. However, there are still technological and fabrication cost issues that could delay large market penetration of white LEDs. Interestingly, SSL may create novel ways of using light that could potentially limit electricity saving. Whatever the impact of SSL, it will be significant on our daily life. The purpose of this special cluster issue is to produce a snapshot of the current situation of SSL from different viewing angles. In an introductory paper, Tsao and co-workers from Sandia National Laboratories, present an energy-economics perspective of SSL considering societal changes and SSL technology evolution. In a second article, Narukawa et al working at Nichia Corporation—the pioneer and still the leading company in SSL—describe the state of the art of current research products. They demonstrate record performance with white LEDs exhibiting luminous efficacy of 183 lm W-1 at high-current injection. Then, a series of topical papers discuss in detail various aspects of the physics and technology of white LEDs Carrier localization in InGaN quantum wells has been considered the key to white LEDs' success despite the huge density of defects. A

  8. Green solution: 120W ArF immersion light source supporting the next-generation multiple-pattering lithography

    Science.gov (United States)

    Kumazaki, Takahito; Ohta, Takeshi; Ishida, Keisuke; Tsushima, Hiroaki; Kurosu, Akihiko; Kakizaki, Kouji; Matsunaga, Takashi; Mizoguchi, Hakaru

    2015-03-01

    The difficulty of EUV lithography system development has prolonged the industry's dependence on ArF excimer lasers to realize further advancements in lithography process technologies. Smaller CD with reduced cost requires tighter specifications, and the potential extension to 450mm wafers introduces extremely difficult performance challenges on lasers. One of the most important features of the next generation lasers will be the ability to support green operations while further improving cost of ownership and performance. For example, electricity consumption costs and the dependence on rare gases, such as neon and helium, will become critical considerations for HVM process going forward. As a laser vendor, Gigaphoton continues to innovate and develop solutions that address these important issues. The latest model GT64A with its field-proven, twin-chamber platform has reduced environmental impact while upgrading performance and power. A variety of green technologies are employed on the GT64A. The first is the reduction of gas usage. Parameters, such as input power and gas pressure are closely monitored during operations and fed back to the injection/exhaust gas controller system. By applying a special algorithm, the laser gas consumption can be reduced by up to 50%. More than 96% of the gas used by the lasers is neon. Another rare gas that requires attention is Helium. Recently the unstable supply of helium became a serious worldwide issue. To cope with this situation, Gigaphoton is developing lasers that support completely helium-free operations.

  9. Intermediate energy light sources and the SSRF project

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Advances in insertion device technology, top-up operation and superconducting RF cavities make it possible to generate high brightness X-ray with intermediate energy light sources, which leads a new trend in designing and constructing third generation light sources around the world. The development status and the remarkable technical features of intermediate energy light sources are reviewed, and the main SSRF properties are described in this paper.

  10. Solid-State Spectral Light Source System

    Science.gov (United States)

    Maffione, Robert; Dana, David

    2011-01-01

    A solid-state light source combines an array of light-emitting diodes (LEDs) with advanced electronic control and stabilization over both the spectrum and overall level of the light output. The use of LEDs provides efficient operation over a wide range of wavelengths and power levels, while electronic control permits extremely stable output and dynamic control over the output. In this innovation, LEDs are used instead of incandescent bulbs. Optical feedback and digital control are used to monitor and regulate the output of each LED. Because individual LEDs generate light within narrower ranges of wavelengths than incandescent bulbs, multiple LEDs are combined to provide a broad, continuous spectrum, or to produce light within discrete wavebands that are suitable for specific radiometric sensors.

  11. LIGHT SOURCE: Conceptual design of Hefei advanced light source

    Science.gov (United States)

    Li, Wei-Min; Wang, Lin; Feng, Guang-Yao; Zhang, Shan-Cai; Wu, Cong-Feng; Xu, Hong-Liang; Liu, Zu-Ping

    2009-06-01

    The conceptual of Hefei Advanced Light Source, which is an advanced VUV and Soft X-ray source, was developed at NSRL of USTC. According to the synchrotron radiation user requirements and the trends of SR source development, some accelerator-based schemes were considered and compared; furthermore storage ring with ultra low emittance was adopted as the baseline scheme of HALS. To achieve ultra low emittance, some focusing structures were studied and optimized in the lattice design. Compromising of emittance, on-momentum and off-momentum dynamic aperture and ring scale, five bend acromat (FBA) was employed. In the preliminary design of HALS, the emittance was reduced to sub nm · rad, thus the radiation up to water window has full lateral coherence. The brilliance of undulator radiation covering several eVs to keVs range is higher than that of HLS by several orders. The HALS should be one of the most advanced synchrotron radiation light sources in the world.

  12. INTERMEDIATE-ENERGY LIGHT SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Corbett, William

    2002-11-25

    Increasingly, atomic scale information underlies scientific and technological progress in disciplines ranging from pharmaceutical development to materials synthesis to environmental remediation. While a variety of research tools are used to provide atomic scale information, synchrotron radiation has proved invaluable in this quest. The rapid growth of soft- and hard X-ray synchrotron light sources stands as stark testimony to the importance and utility of synchrotron radiation. Starting from just a handful of synchrotron light sources in the early 1970s, this burgeoning field now includes over 70 proposed, in-construction, or operating facilities in 23 countries on five continents. Along the way, synchrotron light facilities have evolved from small laboratories extracting light parasitically from storage rings designed for high-energy physics research to large, dedicated sources using the latest technology to produce extraordinarily bright photon beams. The basic layout of a multi-GeV storage ring light source employs periodic bending magnets to guide a charged particle beam around the storage ring. As the charged beam is accelerated in an arc, it produces a sweeping fan of synchrotron radiation that extends from the infrared part of the electromagnetic spectrum (<1 eV) to hard X rays (>20 keV). Quadrupole magnets keep the electrons tightly focused, and a radio-frequency acceleration system replenishes beam energy lost to radiation emission. To optimize the output radiation, a premium is placed on high current electron beams with small cross section and extreme position stability. Magnetic insertion devices are used to further enhance radiation output by a factor of 10 or more over bend magnet sources. The storage ring vacuum chamber includes exit ports to allow portions of the radiation fan to propagate down photon beam transport lines to optical systems and experimental stations. A typical storage ring features 10 or more such radiation ports. The photon beam

  13. A directly phase-modulated light source

    CERN Document Server

    Yuan, Z L; Lucamarini, M; Roberts, G L; Dynes, J F; Shields, A J

    2016-01-01

    The art of imparting information onto a light wave by optical signal modulation is fundamental to all forms of optical communication. Among many schemes, direct modulation of laser diodes stands out as a simple, robust, and cost effective method. However, the simultaneous changes in intensity, frequency and phase are a drawback which has prevented its application in the field of secure quantum communication. Here, we propose and experimentally demonstrate a directly phase-modulated light source which overcomes the main disadvantages associated with direct modulation and is suitable for diverse applications such as coherent communications and quantum cryptography. The source separates the tasks of phase preparation and pulse generation between a pair of semiconductor lasers leading to very pure phase states. Moreover, the cavity enhanced electro-optic effect enables the first example of sub-volt halfwave phase modulation at high signal rates. The source is compact, stable and versatile, and we show its potenti...

  14. Solid-State Light Sources Getting Smart

    National Research Council Canada - National Science Library

    E. Fred Schubert; Jong Kyu Kim

    2005-01-01

    .... Such "smart" light sources can adjust to specific environments and requirements, a property that could result in tremendous benefits in lighting, automobiles, transportation, communication, imaging, agriculture, and medicine.

  15. Driver circuit for solid state light sources

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, Fred; Denvir, Kerry; Allen, Steven

    2016-02-16

    A driver circuit for a light source including one or more solid state light sources, a luminaire including the same, and a method of so driving the solid state light sources are provided. The driver circuit includes a rectifier circuit that receives an alternating current (AC) input voltage and provides a rectified AC voltage. The driver circuit also includes a switching converter circuit coupled to the light source. The switching converter circuit provides a direct current (DC) output to the light source in response to the rectified AC voltage. The driver circuit also includes a mixing circuit, coupled to the light source, to switch current through at least one solid state light source of the light source in response to each of a plurality of consecutive half-waves of the rectified AC voltage.

  16. Superluminescent Diode Light Sources for OCT

    Science.gov (United States)

    Shidlovski, Vladimir R.

    Contrary to laser diodes, the path of superluminescent diodes (SLDs) to widespread practical use was much longer. There was always a scientific interest in "superluminescent" light output from laser diode structures slightly below threshold that might be considerably enhanced by "damping" of the laser resonator. SLD design efforts were intensified in early 1980s when it was proved that they are "light sources of choice" for fiber-optic gyroscopes. The next wave of interest to SLDs as a "stand-alone" type of semiconductor emitters was related to advances in OCT technologies. Challenging OCT requirements, e.g. simultaneous high-power, high brightness and very low coherence length of a light source, resulted in the development of new generation of SLDs characterized by output power and brightness the same as that of medium-to-high power laser diodes, but with the spectral width and flatness of edge-emitting LEDs. In this chapter, the main principles of the development of powerful broadband SLDs and ultra-low-coherence SLD-based light sources in 650-1600 nm spectral range, and the main parameters reported to date, are reviewed. Important aspects of SLD use in practice are discussed.

  17. Source-Independent Quantum Random Number Generation

    Science.gov (United States)

    Cao, Zhu; Zhou, Hongyi; Yuan, Xiao; Ma, Xiongfeng

    2016-01-01

    Quantum random number generators can provide genuine randomness by appealing to the fundamental principles of quantum mechanics. In general, a physical generator contains two parts—a randomness source and its readout. The source is essential to the quality of the resulting random numbers; hence, it needs to be carefully calibrated and modeled to achieve information-theoretical provable randomness. However, in practice, the source is a complicated physical system, such as a light source or an atomic ensemble, and any deviations in the real-life implementation from the theoretical model may affect the randomness of the output. To close this gap, we propose a source-independent scheme for quantum random number generation in which output randomness can be certified, even when the source is uncharacterized and untrusted. In our randomness analysis, we make no assumptions about the dimension of the source. For instance, multiphoton emissions are allowed in optical implementations. Our analysis takes into account the finite-key effect with the composable security definition. In the limit of large data size, the length of the input random seed is exponentially small compared to that of the output random bit. In addition, by modifying a quantum key distribution system, we experimentally demonstrate our scheme and achieve a randomness generation rate of over 5 ×103 bit /s .

  18. Powerful nanosecond light sources based on LEDs for astroparticle physics experiments

    OpenAIRE

    Lubsandorzhiev, B. K.; Poleshuk, R. V.; Shaibonov, B. A. J.; Vyatchin, Y. E.

    2007-01-01

    Powerful nanosecond light sources based on LEDs have been developed for use in astroparticle physics experiments. The light sources use either matrixes of ultra bright blue LEDs or a new generation high power blue LEDs. It's shown that such light sources have light yield of up to 10**10 - 10**12 photons per pulse with very fast light emission kinetics. The described light sources are important for use in calibration systems of Cherenkov and scintillator detectors. The developed light sources ...

  19. Imitating Broadband Diurnal Light Variations Using Solid State Light Sources

    Science.gov (United States)

    Ferguson, Ian; Melton, Andrew; Li, Nola; Nicol, David; Park, Eun Hyun; Tosini, Gianluca

    Many studies have documented the success of light therapy in treating disorders of the human internal clock (circadian rhythm). Recent biological research has shown the importance of developing light sources that are tunable in the blue region of the spectrum for treatment to be safe and effective. A novel tunable broadband solid-state light source is presented here that mimics the diurnal variation in sunlight by modulating the intensity of blue light emission.

  20. Integrated source of broadband quadrature squeezed light

    DEFF Research Database (Denmark)

    Hoff, Ulrich Busk; Nielsen, Bo Melholt; Andersen, Ulrik Lund

    2015-01-01

    An integrated silicon nitride resonator is proposed as an ultracompact source of bright single-mode quadrature squeezed light at 850 nm. Optical properties of the device are investigated and tailored through numerical simulations, with particular attention paid to loss associated with interfacing...... squeezing spectrum for intra-cavity pump self-phase modulation. Subject to standard material loss and detection efficiencies, we find that the device holds promises for generating substantial quantum noise squeezing over a bandwidth exceeding 1 GHz. In the low-propagation loss regime, approximately -6 d...

  1. 30 years of squeezed light generation

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund; Gehring, Tobias; Marquardt, Christoph;

    2016-01-01

    Squeezed light generation has come of age. Significant advances on squeezed light generation have been made over the last 30 years—from the initial, conceptual experiment in 1985 till today’s top-tuned, application-oriented setups. Here we review the main experimental platforms for generating qua...

  2. The Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Galayda, John N

    2003-05-21

    A collaboration of scientists from SLAC, UCLA, Los Alamos National Laboratory, Brookhaven National Laboratory, and Argonne National Laboratory have proposed to build the Linac Coherent Light Source (LCLS) facility, a free-electron laser (FEL) on the SLAC site, spanning photon energies 0.8-8 keV. The laser output will be 8-10 GW with pulse lengths 230 fsec or less. The LCLS will offer unprecedented experimental opportunities in the areas of atomic physics, chemical dynamics, plasma physics, nanoscale dynamics, and biomolecular imaging. SLAC has proposed to begin engineering design of the laser in 2003, leading to project completion in 2008. The laser produces x-rays by the self-amplified spontaneous emission (SASE) process: an intense, highly collimated pulse of 14.5 GeV electrons, traveling through a 122 m-long undulator magnet system, is induced by its own synchrotron radiation to form sub-nanometer-scale bunches. The bunching process enhances the coherence and hence the intensity of the emitted synchrotron radiation. The process is analogous to the instability of a high-gain amplifier; the ''noise'' signal that seeds the instability is the shot noise in the electron beam.

  3. Commissioning of SAGA Light Source

    CERN Document Server

    Tomimasu, Takio; Koda, Shigeru; Ohgaki, Hideaki; Takabayashi, Yuichi; Toyokawa, Hiroyuki; Yasumoto, Masato; Yoshida, Katuhide

    2005-01-01

    The SAGA Light Source (SAGA-LS) consists of a 250-MeV electron linac injector and an eight-hold symmetry 1.4-GeV storage ring with eight double-bend (DB) cell and eight 2.93-m long straight sections. The DB cell structure with a distributed dispersion system was chosen to produce a compact ring of 75.6-m long circumference. The machine construction begun September 29, 2003. The ring magnets of steel laminated structure, vacuum chambers made of aluminum alloy, pumping systems and four temperature controlled cooling water systems for the linac accelerating wave guides etc. were installed in March, 2004. The injector, a 500-MHz ring rf damped cavity, rf klystrons, beam transport systems for injection and their controlled systems were installed in July, 2004. The commissioning begun August 25, 2004. A 250-MeV beam was accelerated on September 29. The beam size is 1-mm in diameter and the energy spread is 0.8 % (FWHM). The first revolution of 250-MeV beam around the ring took place October 22. Beam was stored on N...

  4. Development of a circadian light source

    Science.gov (United States)

    Nicol, David B.; Ferguson, Ian T.

    2002-11-01

    Solid state lighting presents a new paradigm for lighting - controllability. Certain characteristics of the lighting environment can be manipulated, because of the possibility of using multiple LEDs of different emission wavelengths as the illumination source. This will provide a new, versatile, general illumination source due to the ability to vary the spectral power distribution. New effects beyond the visual may be achieved that are not possible with conventional light sources. Illumination has long been the primary function of lighting but as the lighting industry has matured the psychological aspects of lighting have been considered by designers; for example, choosing a particular lighting distribution or color variation in retail applications. The next step in the evolution of light is to consider the physiological effects of lighting that cause biological changes in a person within the environment. This work presents the development of a source that may have important bearing on this area of lighting. A circadian light source has been developed to provide an illumination source that works by modulating its correlated color temperature to mimic the changes in natural daylight through the day. In addition, this source can cause or control physiological effects for a person illuminated by it. The importance of this is seen in the human circadian rhythm's peak response corresponding to blue light at ~460 nm which corresponds to the primary spectral difference in increasing color temperature. The device works by adding blue light to a broadband source or mixing polychromatic light to mimic the variation of color temperature observed for the Planckian Locus on the CIE diagram. This device can have several applications including: a tool for researchers in this area, a general illumination lighting technology, and a light therapy device.

  5. The JLab high power ERL light source

    Energy Technology Data Exchange (ETDEWEB)

    G.R. Neil; C. Behre; S.V. Benson; M. Bevins; G. Biallas; J. Boyce; J. Coleman; L.A. Dillon-Townes; D. Douglas; H.F. Dylla; R. Evans; A. Grippo; D. Gruber; J. Gubeli; D. Hardy; C. Hernandez-Garcia; K. Jordan; M.J. Kelley; L. Merminga; J. Mammosser; W. Moore; N. Nishimori; E. Pozdeyev; J. Preble; R. Rimmer; Michelle D. Shinn; T. Siggins; C. Tennant; R. Walker; G.P. Williams and S. Zhang

    2005-03-19

    A new THz/IR/UV photon source at Jefferson Lab is the first of a new generation of light sources based on an Energy-Recovered, (superconducting) Linac (ERL). The machine has a 160 MeV electron beam and an average current of 10 mA in 75 MHz repetition rate hundred femtosecond bunches. These electron bunches pass through a magnetic chicane and therefore emit synchrotron radiation. For wavelengths longer than the electron bunch the electrons radiate coherently a broadband THz {approx} half cycle pulse whose average brightness is > 5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20 W of average power extracted[1]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100 fs pulses with >200 W of average power. The FELs also provide record-breaking laser power [2]: up to 10 kW of average power in the IR from 1 to 14 microns in 400 fs pulses at up to 74.85 MHz repetition rates and soon will produce similar pulses of 300-1000 nm light at up to 3 kW of average power from the UV FEL. These ultrashort pulses are ideal for maximizing the interaction with material surfaces. The optical beams are Gaussian with nearly perfect beam quality. See www.jlab.org/FEL for details of the operating characteristics; a wide variety of pulse train configurations are feasible from 10 microseconds long at high repetition rates to continuous operation. The THz and IR system has been commissioned. The UV system is to follow in 2005. The light is transported to user laboratories for basic and applied research. Additional lasers synchronized to the FEL are also available. Past activities have included production of carbon nanotubes, studies of vibrational relaxation of interstitial hydrogen in silicon, pulsed laser deposition and ablation, nitriding of metals, and energy flow in proteins. This paper will present the status of the system and discuss some of the discoveries we have made

  6. The First Sources of Light

    Science.gov (United States)

    Loeb, Avi

    2011-09-01

    Looking deep into the Universe through powerful telescopes, we can see images of the Universe when it was younger because of the finite time it takes light to travel to us from distant sources. Existing data sets include an image of the Universe when it was 0.4 million years old (in the form of the cosmic microwave background), as well as images of individual galaxies when the Universe was older than a billion years. But there is a serious challenge: in between these two epochs was a period when the Universe was dark, stars had not yet formed, and the cosmic microwave background no longer traced the distribution of matter. And this is precisely the most interesting period, when the primordial soup evolved into the rich zoo of objects we now see. The observers are moving ahead along several fronts. The first involves the construction of large infrared telescopes on the ground and in space, that will provide us with new photos of the first galaxies. Current plans include ground-based telescopes which are 24-42 meter in diameter, and NASA's successor to the Hubble Space Telescope, called the James Webb Space Telescope. In addition, several observational groups around the globe are constructing radio arrays that will be capable of mapping the three-dimensional distribution of cosmic hydrogen in the infant Universe. These arrays are aiming to detect the long-wavelength (redshifted 21-cm) radio emission from hydrogen atoms. The images from these antenna arrays will reveal how the non-uniform distribution of neutral hydrogen evolved with cosmic time and eventually was extinguished by the ultra-violet radiation from the first galaxies. Theoretical research has focused in recent years on predicting the expected signals for the above instruments and motivating these ambitious observational projects.

  7. New results in atomic physics at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Schlachter, A.S.

    1995-01-01

    The Advanced Light Source is the world's first low-energy third-generation synchrotron radiation source. It has been running reliably and exceeding design specifications since it began operation in October 1993. It is available to a wide community of researchers in many scientific fields, including atomic and molecular science and chemistry. Here, new results in atomic physics at the Advanced Light Source demonstrate the opportunities available in atomic and molecular physics at this synchrotron light source. The unprecedented brightness allows experiments with high flux, high spectral resolution, and nearly 100% linear polarization.

  8. Directly Phase-Modulated Light Source

    Science.gov (United States)

    Yuan, Z. L.; Fröhlich, B.; Lucamarini, M.; Roberts, G. L.; Dynes, J. F.; Shields, A. J.

    2016-07-01

    The art of imparting information onto a light wave by optical signal modulation is fundamental to all forms of optical communication. Among many schemes, direct modulation of laser diodes stands out as a simple, robust, and cost-effective method. However, the simultaneous changes in intensity, frequency, and phase have prevented its application in the field of secure quantum communication. Here, we propose and experimentally demonstrate a directly phase-modulated light source which overcomes the main disadvantages associated with direct modulation and is suitable for diverse applications such as coherent communications and quantum cryptography. The source separates the tasks of phase preparation and pulse generation between a pair of semiconductor lasers leading to very pure phase states. Moreover, the cavity-enhanced electro-optic effect enables the first example of subvolt half-wave phase modulation at high signal rates. The source is compact, stable, and versatile, and we show its potential to become the standard transmitter for future quantum communication networks based on attenuated laser pulses.

  9. Superbend upgrade on the Advanced Light Source

    Science.gov (United States)

    Robin, D.; Krupnick, J.; Schlueter, R.; Steier, C.; Marks, S.; Wang, B.; Zbasnik, J.; Benjegerdes, R.; Biocca, A.; Bish, P.; Brown, W.; Byrne, W.; Chen, J.; Decking, W.; DeVries, J.; DeMarco, W. R.; Fahmie, M.; Geyer, A.; Harkins, J.; Henderson, T.; Hinkson, J.; Hoyer, E.; Hull, D.; Jacobson, S.; McDonald, J.; Molinari, P.; Mueller, R.; Nadolski, L.; Nishimura, H.; Nishimura, K.; Ottens, F.; Paterson, J. A.; Pipersky, P.; Portmann, G.; Ritchie, A.; Rossi, S.; Salvant, B.; Scarvie, T.; Schmidt, A.; Spring, J.; Taylor, C.; Thur, W.; Timossi, C.; Wandesforde, A.

    2005-02-01

    The Advanced Light Source (ALS) is a third generation synchrotron light source at Lawrence Berkeley National Laboratory (LBNL). There was an increasing demand for additional high brightness hard X-ray beamlines in the 7-40 keV range, so in August 2001, three 1.3 T normal conducting bending magnets were removed from the storage ring and replaced with 5 T superconducting magnets (Superbends). The radiation produced by these Superbends is an order of magnitude higher in photon brightness and flux at 12 keV, making them excellent sources of hard X-rays for protein crystallography and other hard X-ray applications. The Superbends did not compromise the performance of the facility in the VUV and soft X-ray regions of the spectrum. The Superbends will eventually feed 12 new beam lines, greatly enhancing the facility's capability and capacity in the hard X-ray region. The Superbend project is the biggest upgrade since the ALS storage ring was commissioned in 1993. In this paper we present an overview of the Superbend project, its challenges and the resulting impact on the ALS.

  10. Two-mirrored galvanometer laser light sheet generator

    Science.gov (United States)

    Leighty, B. D.; Franke, J. M.; Jones, S. B.; Rhodes, D. B.

    1988-01-01

    Light sheets generated with either laser or noncoherent sources have found widespread application to flow visualization. Previous light sheet generating systems were usually dedicated to a specific viewing geometry. The technique with the most flexibility is the galvanometer mirror based laser light sheet system. A two-mirrored system was designed and developed to provide flexibility and adaptability to a wide range of applications. The design includes the capability to control the size and location of the laser light sheet in real time, to generate horizontal or vertical sheets, to sweep the sheet repeatedly through a volume, to generate multiple sheets with controllable separation and to rotate single or multiple laser light sheets. The system is capable of producing up to 12 sheets of laser light at an angular divergence of + or - 20 degrees. Maximum scan rate of any one line is 500 Hertz. This system has proven to be uniquely versatile and a patent has been applied for.

  11. Virtual Generation (Energy Efficiency) The Cheapest Source For Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Hasnie, Sohail

    2010-09-15

    Energy efficiency is the cheapest source of energy that has escaped the minds of the politicians in the developing countries. This paper argues for large scale utility led end use efficiency programs in a new paradigm, where 1 million efficient light bulbs is synonymous to a 50 MW power station that costs only 2% of the traditional fossil fuel power station and zero maintenance. Bulk procurement, setting up new standards and generation of certified emissions reduction is part of this strategy. It discusses implementation of a $20 million pilot in the Philippines supported by the Asian Development Bank.

  12. Light Sources Technologies and Applications

    CERN Document Server

    Kitsinelis, Spyridon

    2010-01-01

    From the dialogues of the ancient Greek philosophers right up through the physical laws of Newton, the experiments of Thomas Young and the quantum physics pioneers, the study of light was all about observing its characteristics and defining its behavior. At the end of the 19th century, wicks, wax, and oil gave way to electricity, filaments, and gases, and scientific minds began to focus on the technological creation of light, as well as its control and diverse uses. Yet, despite more than a century of profound research and development, until now, the most complete resources on lighting technol

  13. Advanced light source, User`s Handbook, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The Advanced Light Source (ALS) is a national facility for scientific research and development located at the Lawrence Berkeley National Laboratory (LBNL) of the University of California. Its purpose is to generate beams of very bright light in the ultraviolet and soft x-ray regions of the spectrum. The facility is open to researchers from industry, universities, and government laboratories.

  14. Control and Driving Methods for LED Based Intelligent Light Sources

    DEFF Research Database (Denmark)

    Beczkowski, Szymon

    High power light-emitting diodes allow the creation of luminaires capable of generating saturated colour light at very high efficacies. Contrary to traditional light sources like incandescent and high-intensity discharge lamps, where colour is generated using filters, LEDs use additive light mixing......, where the intensity of each primary colour diode has to be adjusted to the needed intensity to generate specified colour. The function of LED driver is to supply the diode with power needed to achieve the desired intensity. Typically, the drivers operate as a current source and the intensity...... current. The model can also be used to create highly accurate luminaire model. Finally, a dual interleaved buck converter has been proposed for driving high power light-emitting diodes. Interleaving two converters lowers the output ripple current thus lowering the requirement on the output capacitor...

  15. Wavelength-tunable duplex integrated light source

    Science.gov (United States)

    Okamoto, Hiroshi; Yasaka, Hiroshi; Oe, Kunishige

    1996-04-01

    A monolithically integrated opto-electronic device is proposed as a fast wavelength-switching light source. This tunable duplex integrated light source comprises two wavelength-tunable distributed Bragg reflector (DBR) laser diodes (LDs), two MQW-electro-absorption optical switches, a Y-shaped waveguide coupler, a MQW-electro-absorption modulator, and two thermal drift compensators (TDCs). The wavelength-switching time of the optical switches was estimated to be 60 ps including a 50-ps rise time for the electrical-pulse generator. The wavelength of a 10-Gbit/s NRZ-modulated optical signal can be switched without bit loss. The function of the TDCs is to keep the device-chip temperature constant. Thermal-transient- induced wavelength drift with a millisecond-order time constant, which has been reported for DBR-LDs, and thermal crosstalk between the tuning regions of the integrated LDs, which causes wavelength fluctuation, are effectively suppressed by thermal-drift-compensation operation using the TDCs.

  16. High-Energy Compton Scattering Light Sources

    CERN Document Server

    Hartemann, Fred V; Barty, C; Crane, John; Gibson, David J; Hartouni, E P; Tremaine, Aaron M

    2005-01-01

    No monochromatic, high-brightness, tunable light sources currently exist above 100 keV. Important applications that would benefit from such new hard x-ray sources include: nuclear resonance fluorescence spectroscopy, time-resolved positron annihilation spectroscopy, and MeV flash radiography. The peak brightness of Compton scattering light sources is derived for head-on collisions and found to scale with the electron beam brightness and the drive laser pulse energy. This gamma 2

  17. Towards the Optimum Light Source Spectrum

    Directory of Open Access Journals (Sweden)

    Andrew Chalmers

    2010-01-01

    Full Text Available This paper is concerned with designing light source spectra for optimum luminous efficacy and colour rendering. We demonstrate that it is possible to design light sources that can provide both good colour rendering and high luminous efficacy by combining the outputs of a number of narrowband spectral constituents. Also, the achievable results depend on the numbers and wavelengths of the different spectral bands utilized in the mixture. Practical realization of these concepts has been demonstrated in this pilot study which combines a number of simulations with tests using real LEDs (light emitting diodes. Such sources are capable of providing highly efficient lighting systems with good energy conservation potential. Further research is underway to investigate the practicalities of our proposals in relation to large-scale light source production.

  18. Diamond Light Source: status and perspectives.

    Science.gov (United States)

    Materlik, Gerhard; Rayment, Trevor; Stuart, David I

    2015-03-06

    Diamond Light Source, a third-generation synchrotron radiation (SR) facility in the UK, celebrated its 10th anniversary in 2012. A private limited company was set up in April 2002 to plan, construct and operate the new user-oriented SR facility, called in brief Diamond. It succeeded the Synchrotron Radiation Source in Daresbury, a second-generation synchrotron that opened in 1980 as the world's first dedicated X-ray-providing facility, closing finally in 2008, by which time Diamond's accelerators and first beamlines were operating and user experiments were under way. This theme issue of Philosophical Transactions of the Royal Society A gives some examples of the rich diversity of research done in the initial five years, with some glimpses of activity up to 2014. Speakers at the 10 year anniversary symposium were drawn from a small number of major thematic areas and each theme was elaborated by a few speakers whose contributions were placed into a broader context by a leading member of the UK academic community in the role of rapporteur. This introduction gives a summary of the design choices and strategic planning of Diamond as a coherent user facility, a snapshot of its present status and some consideration of future perspectives.

  19. The Linac Coherent Light Source Project

    Energy Technology Data Exchange (ETDEWEB)

    Galayda, John N

    2003-08-11

    The Linac Coherent Light Source Project will make use of the last kilometer of the SLAC Linac to create the world's first ''hard'' x-ray laser. A high-brightness photocathode gun and 150 MeV pre-accelerator will be installed in an alcove adjoining the main linac tunnel. It will provide 1 nanocoulomb electron bunches at 120 Hz. The main linac will be modified to incorporate two chicane bunch compressors. Electron bunches with 230 fsec FWHM duration and 3400 ampere peak current will be delivered to the enclosure presently housing the Final Focus Test Beam Facility. These electron bunches will pass through a 122-meter undulator channel, producing a burst of coherent x-rays with peak brightness ten orders of magnitude higher than is presently available from the brightest third-generation storage ring sources. This extraordinary brightness and coherence is the result of the ''self-amplified spontaneous emission'' (SASE) process. The LCLS Project will include x-ray optics, diagnostics and beamline facilities in two experiment halls, respectively located 40 meters and 322 meters from the source of x-rays. The LCLS will be constructed by a collaboration of US laboratories: Argonne National Labs, Lawrence Livermore National Lab, and SLAC. A conceptual design has been completed and funds for a more complete design are expected in October 2002. The Project completion date is September 2008.

  20. Matrix light and pixel light: optical system architecture and requirements to the light source

    Science.gov (United States)

    Spinger, Benno; Timinger, Andreas L.

    2015-09-01

    Modern Automotive headlamps enable improved functionality for more driving comfort and safety. Matrix or Pixel light headlamps are not restricted to either pure low beam functionality or pure high beam. Light in direction of oncoming traffic is selectively switched of, potential hazard can be marked via an isolated beam and the illumination on the road can even follow a bend. The optical architectures that enable these advanced functionalities are diverse. Electromechanical shutters and lens units moved by electric motors were the first ways to realize these systems. Switching multiple LED light sources is a more elegant and mechanically robust solution. While many basic functionalities can already be realized with a limited number of LEDs, an increasing number of pixels will lead to more driving comfort and better visibility. The required optical system needs not only to generate a desired beam distribution with a high angular dynamic, but also needs to guarantee minimal stray light and cross talk between the different pixels. The direct projection of the LED array via a lens is a simple but not very efficient optical system. We discuss different optical elements for pre-collimating the light with minimal cross talk and improved contrast between neighboring pixels. Depending on the selected optical system, we derive the basic light source requirements: luminance, surface area, contrast, flux and color homogeneity.

  1. Supercontinuum light sources for food analysis

    DEFF Research Database (Denmark)

    Møller, Uffe Visbech; Petersen, Christian Rosenberg; Kubat, Irnis

    2014-01-01

    . One track of Light & Food will target the mid-infrared spectral region. To date, the limitations of mid-infraredlight sources, such as thermal emitters, low-power laser diodes, quantum cascade lasers and synchrotron radiation, have precluded mid-IR applications where the spatial coherence, broad...... and in the factory. These solutions will combine bright and broadband infrared light sources, so-called supercontinuum light sources,with spectroscopy, chemometrics and processing expertise and thereby contribute to increased food quality through faster and more precise analysis of grains, soils and dairy products...

  2. COMPARATIVE STUDY OF LIGHT SOURCES FOR HOUSEHOLD

    Directory of Open Access Journals (Sweden)

    Andrzej PAWLAK

    2017-01-01

    Full Text Available The article describes test results that provided the ground to define and evaluate basic photometric, colorimetric and electric parameters of selected, widely available light sources, which are equivalent to a traditional incandescent 60-Watt light bulb. Overall, one halogen light bulb, three compact fluorescent lamps and eleven LED light sources were tested. In general, it was concluded that in most cases (branded products, in particular the measured and calculated parameters differ from the values declared by manufacturers only to a small degree. LED sources prove to be the most beneficial substitute for traditional light bulbs, considering both their operational parameters and their price, which is comparable with the price of compact fluorescent lamps or, in some instances, even lower.

  3. Advanced Light Source Activity Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    Duque, Theresa; Greiner, Annette; Moxon, Elizabeth; Robinson, Arthur; Tamura, Lori (Editors)

    2003-06-12

    This annual report of the Advanced Light Source details science highlights and facility improvements during the year. It also offers information on events sponsored by the facility, technical specifications, and staff and publication information.

  4. National Synchrotron Light Source annual report 1988

    Energy Technology Data Exchange (ETDEWEB)

    Hulbert, S.; Lazarz, N.; Williams, G. (eds.)

    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)

  5. Advanced Light Source Activity Report 2000

    Energy Technology Data Exchange (ETDEWEB)

    Greiner, A.; Moxon, L.; Robinson, A.; Tamura, L.

    2001-04-01

    This is an annual report, detailing activities at the Advanced Light Source for the year 2000. It includes highlights of scientific research by users of the facility as well as information about the development of the facility itself.

  6. Synchrotron Light Sources in Developing Countries

    Science.gov (United States)

    Winick, Herman; Pianetta, Piero

    2017-01-01

    The more than 50 light sources now in operation around the world include facilities in Brazil, Korea, and Taiwan which started their programs in the 1980's when they were developing countries. They came on line in the 1990's and have since trained hundreds of graduate students locally, without sending them abroad and losing many of them. They have also attracted dozens of mid-career diaspora scientists to return. Their growing user communities have demanded more advanced facilities, leading to the funding of higher performance new light sources that are now coming into operation. Light sources in the developing world now include the following: SESAME in the Middle East which is scheduled to start research in 2017 (www.sesame.org); The African Light Source, in the planning stage (www.africanlightsource.org); and The Mexican Light Source, in the planning stage (http://www.aps.org/units/fip/newsletters/201509/mexico.cfm). See: http://wpj.sagepub.com/content/32/4/92.full.pdf +html; http://www.lightsources.org/press-release/2015/11/20/grenoble-resolutions-mark-historical-step-towards-african-light-source. 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.

  7. Status of the Metrology Light Source

    Science.gov (United States)

    Klein, R.; Ulm, G.; Feikes, J.; Hartrott, M. v.; Wüstefeld, G.

    2010-06-01

    The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, has set up the low-energy electron storage ring Metrology Light Source (MLS) in close cooperation with the Helmholtz-Zentrum Berlin (HZB, formerly BESSY). This new storage ring has been in regular user operation since April 2008 and is dedicated to synchrotron-radiation-based metrology and technological developments in the far-IR/THz, IR, UV, VUV and EUV spectral range. The MLS has a double-bend-achromate lattice structure, injection is from a 105 MeV racetrack microtron. The electron energy can be ramped to any value from 105 MeV up to 630 MeV and the electron beam current covers the range from one stored electron (1 pA) up to 200 mA. The MLS is the first electron storage ring optimized for the generation of coherent synchrotron radiation, based on an electron bunch shortening mode. In this mode, MLS delivers coherent radiation in the far-IR/THz spectral range with enhanced intensity as compared to the normal mode of operation. Several beamlines are in operation or in construction, including one undulator beamline, bending magnet beamlines for the calibration of radiation sources and detectors and for reflectometry, an EUV metrology beamline and three IR/THz beamlines.

  8. Optimisation of arbitrary light beam generation with spatial light modulators

    Science.gov (United States)

    Radwell, Neal; Offer, Rachel F.; Selyem, Adam; Franke-Arnold, Sonja

    2017-09-01

    Phase only spatial light modulators (SLMs) have become the tool of choice for shaped light generation, allowing the creation of arbitrary amplitude and phase patterns. These patterns are generated using digital holograms and are useful for a wide range of applications as well as for fundamental research. There have been many proposed methods for optimal generation of the digital holograms, all of which perform well under ideal conditions. Here we test a range of these methods under specific experimental constraints, by varying grating period, filter size, hologram resolution, number of phase levels, phase throw and phase nonlinearity. We model beam generation accuracy and efficiency and show that our results are not limited to the specific beam shapes, but should hold for general beam shaping. Our aim is to demonstrate how to optimise and improve the performance of phase-only SLMs for experimentally relevant implementations.

  9. GPC light shaping a supercontinuum source

    DEFF Research Database (Denmark)

    Kopylov, Oleksii; Bañas, Andrew Rafael; Villangca, Mark Jayson;

    2015-01-01

    incorporating various multi-wavelength approaches into spatially shaped excitations that can enable new broadband light applications. We verify this new approach using a supercontinuum light source, interfaced with a compact GPC light shaper. Our experiments give ~70% efficiency, ~3x intensity gain, and ~85......Generalized Phase Contrast (GPC) is a versatile tool for efficiently rerouting and managing photon energy into speckle-free contiguous spatial light distributions. We have previously shown theoretically and numerically that a GPC Light Shaper shows robustness to shift in wavelength and can maintain...... both projection length scale and high efficiency over a range [0.75λ0; 1.5λ0] with λ0 as the characteristic design wavelength. With this performance across multiple wavelengths and the recent availability of tabletop supercontinuum lasers, GPC light shaping opens the possibility for creatively...

  10. National Synchrotron Light Source 2008 Activity Report

    Energy Technology Data Exchange (ETDEWEB)

    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

  11. White Light Generation in Human Saliva

    Science.gov (United States)

    Santhosh, C.; Dharmadhikari, A. K.; Dharmadhikari, J. A.; Alti, K.; Mathur, D.

    2011-07-01

    Interaction of intense, femto-second pulses of infrared light (800 nm) with water generates white light supercontinuum due to nonlinear optical effects. This supercontinuum was found to be suppressed by the addition of alpha amylase, a major protein in the human saliva. We have studied the suppression of supper continuum by human saliva, collected from healthy subjects with and without smoking habits. Suppression of the blue-sided components was observed significantly in non-smokers saliva than chain smokers.

  12. Ultrahigh resolution optical coherence tomography using a superluminescent light source

    NARCIS (Netherlands)

    Kowalevicz, Andrew M.; Ko, Tony; Hartl, Ingmar; Fujimoto, James G.; Pollnau, Markus; Salathé, René P.

    2002-01-01

    A superluminescent Ti:Al2O3 crystal is demonstrated as a light source for ultrahigh resolution optical coherence tomography (OCT). Single spatial mode, fiber coupled output powers of ~40 μW can be generated with 138 nm bandwidth using a 5 W frequency doubled, diode pumped laser, pumping a thin Ti:Al

  13. Progress of the Synchrotron Light Source ALBA

    CERN Document Server

    Einfeld, Dieter; Campmany, Josep; Muñoz, Marc; Pont, Montserrat

    2005-01-01

    ALBA will be a third generation synchrotron light source built in Spain near Barcelona. Commissioning of the storage ring is foreseen to start at the end of 2008. The design phase of ALBA is almost completed and the first components are ready to be ordered. A 100 MeV LINAC will inject electrons into a nominal energy booster synchrotron of similar circumference as the storage ring, so that both accelerators will share the same tunnel. The storage ring, working at 3 GeV with a circumference of 268.8 m, has been designed for a maximum current of 400 mA. The lattice is based on an extended DBA structure and has a nominal emittance of 4 nm.rad.The machine has a four fold symmetry with 4 long straight sections (8 m), 12 medium (4.2 m) and 8 short (2.6 m). This report concentrates on recent design developments, component choices and current status. Another paper at this conference deals with accelerator physics issues.

  14. IR microscopy utilizing intense supercontinuum light source

    DEFF Research Database (Denmark)

    Dupont, Sune; Petersen, Christian; Thøgersen, Jan;

    2012-01-01

    . The supercontinuum light source has a high brightness and spans the infrared region from 1400 nm to 4000 nm. This combination allows contact free high resolution hyper spectral infrared microscopy. The microscope is demonstrated by imaging an oil/water sample with 20 μm resolution.......Combining the molecular specificity of the infrared spectral region with high resolution microscopy has been pursued by researchers for decades. Here we demonstrate infrared supercontinuum radiated from an optical fiber as a promising new light source for infrared microspectroscopy...

  15. Behavior of Layers under Different Light Sources

    Directory of Open Access Journals (Sweden)

    BO Tavares

    2015-12-01

    Full Text Available ABSTRACT Light is an important factor in the management of laying poultry. The ideal lamp spectrum that provides the best welfare conditions still needs to be determined. Wavelength and light intensity influence poultry behavior and their welfare. This study evaluated the influence of four lamps types with different light spectra on the behavior of seventy 52-week laying hens. Incandescent, fluorescent, and sodium and mercury vapor lamps were set in a different poultry house each and supplied similar light intensities. Layer behavior was video-recorded three times weekly using video cameras installed on the ceiling. The effects of different wavelengths emitted by the light sources on layer behavior were evaluated by the Kruskal-Wallis median test. Results indicated that incandescent and sodium vapor lamps increased the occurrence of nesting, and of active behaviors, such as floor-scratching and pecking.

  16. Coherent Light Sources at the Nanoscale

    Science.gov (United States)

    Yang, Ankun; Wang, Danqing; Wang, Weijia; Odom, Teri W.

    2017-05-01

    This review focuses on coherent light sources at the nanoscale, and specifically on lasers exploiting plasmonic cavities that can beat the diffraction limit of light. Conventional lasers exhibit coherent, intense, and directional emission with cavity sizes much larger than their operating wavelength. Plasmon lasers show ultrasmall mode confinement, support strong light-matter interactions, and represent a class of devices with extremely small sizes. We discuss the differences between plasmon lasers and traditional ones, and we highlight advances in directionality and tunability through innovative cavity designs and new materials. Challenges and future prospects are also discussed.

  17. Intrinsically stable light source at telecom wavelengths

    CERN Document Server

    Monteiro, Fernando; Sanguinetti, Bruno; Zbinden, Hugo

    2013-01-01

    We present a highly stable light source at telecom wavelengths, based on a short erbium doped fiber. The high stability arises from the high inversion of the Er3+ion population. This source is developed to work as a stable reference in radiometric applications and is useful in any application where high stability and/or a large bandwidth are necessary. The achieved long-term stability is 10 ppm.

  18. Ultrahigh resolution optical coherence tomography using a superluminescent light source.

    Science.gov (United States)

    Kowalevicz, Andrew; Ko, Tony; Hartl, Ingmar; Fujimoto, James; Pollnau, Markus; Salathé, René

    2002-04-08

    A superluminescent Ti:Al2O(3) crystal is demonstrated as a light source for ultrahigh resolution optical coherence tomography (OCT). Single spatial mode, fiber coupled output powers of ~40 microW can be generated with 138 nm bandwidth using a 5 W frequency doubled, diode pumped laser, pumping a thin Ti:Al2O(3) crystal. Ultrahigh resolution OCT imaging is demonstrated with 2.2 microm axial resolution in air, or 1.7 microm in tissue, with >86 dB sensitivity. This light source provides a simple and robust alternative to femtosecond lasers for ultrahigh resolution OCT imaging.

  19. Laser wakefield accelerator based light sources: potential applications and requirements

    Energy Technology Data Exchange (ETDEWEB)

    Albert, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). NIF and Photon Sciences; Thomas, A. G. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences; Mangles, S. P.D. [Imperial College, London (United Kingdom). Blackett Lab.; Banerjee, S. [Univ. of Nebraska, Lincoln, NE (United States); Corde, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Flacco, A. [ENSTA, CNRS, Ecole Polytechnique, Palaiseau (France); Litos, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Neely, D. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Viera, J. [Univ. of Lisbon (Portugal). GoLP-Inst. de Plasmas e Fusao Nuclear-Lab. Associado; Najmudin, Z. [Imperial College, London (United Kingdom). Blackett Lab.; Bingham, R. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Joshi, C. [Univ. of California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Katsouleas, T. [Duke Univ., Durham, NC (United States). Platt School of Engineering

    2015-01-15

    In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose as a result of discussions held at the 2013 Laser Plasma Accelerators Workshop. X-ray phase contrast imaging, X-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted as potential applications for laser-plasma based light sources. We discuss ongoing and future efforts to improve the properties of radiation from plasma betatron emission and Compton scattering using laser wakefield accelerators for these specific applications.

  20. Integrated source of broadband quadrature squeezed light

    DEFF Research Database (Denmark)

    Hoff, Ulrich Busk; Nielsen, Bo Melholt; Andersen, Ulrik Lund

    2015-01-01

    An integrated silicon nitride resonator is proposed as an ultracompact source of bright single-mode quadrature squeezed light at 850 nm. Optical properties of the device are investigated and tailored through numerical simulations, with particular attention paid to loss associated with interfacing...

  1. Momentum aperture of the advanced light source

    Science.gov (United States)

    Decking, W.; Robin, D.

    1999-04-01

    This paper shows measurements of the momentum aperture of the Advanced Light Source (ALS) based on Touschek lifetime measurements. The measured data is compared with tracking simulations and a simple model for the apertures will help to explain the observed effects.

  2. Electrodeless lighting RF power source development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-30

    An efficient, solid state RF power source has been developed on this NICE project for exciting low power electrodeless lamp bulbs. This project takes full advantage of concurrent advances in electrodeless lamp technology. Electrodeless lamp lighting systems utilizing the sulfur based bulb type developed by Fusion Lighting, Inc., is an emerging technology which is based on generating light in a confined plasma created and sustained by RF excitation. The bulb for such a lamp is filled with a particular element and inert gas at low pressure when cold. RF power from the RF source creates a plasma within the bulb which reaches temperatures approaching those of high pressure discharge lamp plasmas. At these temperatures the plasma radiates substantial visible light with a spectrum similar to sunlight.

  3. Electricity generation by intermittent sources

    Science.gov (United States)

    Wagner, F.

    2015-08-01

    This paper deals with the production of electricity by wind and photovoltaic (PV) power mostly in Germany. The German data of 2012 are scaled to a 100% supply of the electricity consumption by renewable sources. Wind and PV power are mixed in a ratio which minimises back-up energy. The 100%, optimal mix data are used to identify the powers to be installed, the accumulating backup and surplus energies, the size of storage to replace thermal back-up power, the possibilities of demand-side-management, and the specific CO2 production. The benefits of using an EU-wide field of renewable energies (RES) instead of the national one are quantified and the interconnection capacities specified. Finally, the costs of installing RES are discussed. The conclusion is that a 100% supply by RES may not be meaningful. Large-scale supply by RES alone has deficiencies and it will remain a major task for science and technology to either improve such a system or find a suitable replacement.

  4. Electricity generation by intermittent sources

    Directory of Open Access Journals (Sweden)

    Wagner F.

    2015-01-01

    Full Text Available This paper deals with the production of electricity by wind and photovoltaic (PV power mostly in Germany. The German data of 2012 are scaled to a 100% supply of the electricity consumption by renewable sources. Wind and PV power are mixed in a ratio which minimises back-up energy. The 100%, optimal mix data are used to identify the powers to be installed, the accumulating backup and surplus energies, the size of storage to replace thermal back-up power, the possibilities of demand-side-management, and the specific CO2 production. The benefits of using an EU-wide field of renewable energies (RES instead of the national one are quantified and the interconnection capacities specified. Finally, the costs of installing RES are discussed. The conclusion is that a 100% supply by RES may not be meaningful. Large-scale supply by RES alone has deficiencies and it will remain a major task for science and technology to either improve such a system or find a suitable replacement.

  5. Determining and quantifying specific sources of light alkane

    Science.gov (United States)

    Bill, M.; Conrad, M. E.

    2015-12-01

    Determining and quantifying specific sources of emission of methane (an important greenhouse gas) and light alkanes from abandoned gas and oil wells, hydraulic fracturing or associated with CO2 sequestration are a challenge in determining their contribution to the atmospheric greenhouse gas budget or to identify source of groundwater contamination. Here, we review organic biogeochemistry proprieties and isotopic fingerprinting of C1-C5 alkanes to address this problem. For instance, the concentration ratios of CH4 to C2-C5 alkanes can be used to distinguish between thermogenic and microbial generated CH4. Together C and H isotopes of CH4 are used to differentiate bacterial generated sources and thermogenic CH4 and may also identify processes such as alteration and source mixing. Carbon isotope ratios pattern of C1-C5 alkanes highlight sources and oxidation processes in the gas reservoirs. Stable carbon isotope measurements are a viable tool for monitoring the degradation progress of methane and light hydrocarbons. The carbon isotope ratios of the reactants and products are independent of the concentration and only depend on the relative progress of the particular reaction. Oxidation/degradation of light alkanes are typically associated with increasing ð13C values. Isotopic mass balances offer the possibility to independently determine the fractions coming from microbial versus thermogenic and would also permit differentiation of the isotope fractionations associated with degradation. Unlike conventional concentration measurements, this approach is constrained by the different isotopic signatures of various sources and sinks.

  6. Spontaneously generated X-shaped light bullets

    CERN Document Server

    Trapani, P D; Piskarskas, A; Jedrkiewicz, O; Trull, J; Conti, C; Trillo, S

    2003-01-01

    We observe the formation of an intense optical wavepacket fully localized in all dimensions, i.e. both longitudinally (in time) and in the transverse plane, with an extension of a few tens of fsec and microns, respectively. Our measurements show that the self-trapped wave is a X-shaped light bullet spontaneously generated from a standard laser wavepacket via the nonlinear material response (i.e., second-harmonic generation), which extend the soliton concept to a new realm, where the main hump coexists with conical tails which reflect the symmetry of linear dispersion relationship.

  7. Narrow-Bandwidth Diode-Laser-Based Ultraviolet Light Source

    Institute of Scientific and Technical Information of China (English)

    PENG Yu; FANG Zhan-Jun; ZANG Er-Jun

    2011-01-01

    A compact, tunable and narrow-bandwidth laser source for ultraviolet radiation is presented. A grating stabilized diode laser at 1064 nm is frequency-stabilized to below 10 kHz by using a ultra low expansion (ULE) cavity. Injecting light of the diode laser into a tapered amplifier yields a power of 290mW. In a first frequency-doubling stage, about 47 mW of green light at 532nm is generated by using a periodical// poled KTP crystal. Subsequent second-harwonic generation employing a BBO crystal leads to about 30μW of ultraviolet light at 266nm.%A compact,tunable and narrow-bandwidth laser source for ultraviolet radiation is presented.A grating stabilized diode laser at 1064nm is frequency-stabilized to below 10kHz by using a ultra low expansion (ULE) cavity.Injecting light of the diode laser into a tapered amplifier yields a power of 290 mW.In a first frequency-doubling stage,about 47mW of green light at 532nm is generated by using a periodically poled KTP crystal.Subsequent second-harmonic generation employing a BBO crystal leads to about 30 μ W of ultraviolet light at 266nm.Hg is,so far,the heaviest nonradioactive atom that has been laser-cooled and trapped.Systematic evaluation of various sources of uncertainty for the Hg-based optical lattice clock is obtained and an accuracy of better than 10-1s is attainable,which is an order of magnitude of improvement over Sr or Yb based clocks because of the reduced susceptibility to the blackbody radiation field,which sets a major limitation on the accuracy of atomic clocks.[1] The 1S0-3p0 transition at 265.6 nm will be exploited as a clock transition.

  8. LED based powerful nanosecond light sources for calibration systems of deep underwater neutrino telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Lubsandorzhiev, B.K. [Institute for Nuclear Research of the Russian Academy of Sciences (Russian Federation); Kepler Center for Astro and Particle Physics, University of Tuebingen (Germany)], E-mail: lubsand@pcbai10.inr.ruhep.ru; Poleshuk, R.V.; Shaibonov, B.A.J.; Vyatchin, Y.E. [Institute for Nuclear Research of the Russian Academy of Sciences (Russian Federation)

    2009-04-11

    Powerful nanosecond light sources based on LEDs have been developed for use in calibration systems of deep underwater neutrino telescopes. The light sources use either matrixes of ultra bright blue InGaN LEDs or new generation high power blue LEDs. It is shown that such light sources have light yield of up to 10{sup 10}-10{sup 12} photons per pulse with very fast light emission kinetics. The developed light sources are currently used in a number of astroparticle physics experiments, namely: the lake Baikal neutrino experiment, the TUNKA EAS experiment, etc.

  9. All solid-state 191.7 nm deep-UV light source by seventh harmonic generation of an 888 nm pumped, Q-switched 1342 nm Nd:YVO₄ laser with excellent beam quality.

    Science.gov (United States)

    Koch, Peter; Bartschke, Juergen; L'huillier, Johannes A

    2014-06-02

    In this paper we report on the realization of a deep-UV light source using the 1.3 μm transition of neodymium as pumping wavelength. The 191.7 nm radiation was obtained by generating the seventh harmonic of a high-power Q-switched 1342 nm Nd:YVO4 laser. A cesium lithium borate crystal was used for sum frequency mixing of the sixth harmonic and the fundamental. With a total of four conversion stages, up to 240 mW were achieved, with excellent beam quality at 155 mW (M2 < 1.7) and 190 mW (M2 < 1.9).

  10. Pioneering SESAME light source officially opened

    CERN Multimedia

    Caraban Gonzalez, Noemi

    2017-01-01

    Allan, Jordan, 16 May 2017. The SESAME light source was today officially opened by His Majesty King Abdullah II. An intergovernmental organization, SESAME is the first regional laboratory for the Middle East and neighbouring regions The laboratory’s official opening ushers in a new era of research covering fields ranging from medicine and biology, through materials science, physics and chemistry to healthcare, the environment, agriculture and archaeology.

  11. Holographic free-electron light source

    Science.gov (United States)

    Li, Guanhai; Clarke, Brendan P.; So, Jin-Kyu; MacDonald, Kevin F.; Zheludev, Nikolay I.

    2016-12-01

    Recent advances in the physics and technology of light generation via free-electron proximity and impact interactions with nanostructures (gratings, photonic crystals, nano-undulators, metamaterials and antenna arrays) have enabled the development of nanoscale-resolution techniques for such applications as mapping plasmons, studying nanoparticle structural transformations and characterizing luminescent materials (including time-resolved measurements). Here, we introduce a universal approach allowing generation of light with prescribed wavelength, direction, divergence and topological charge via point-excitation of holographic plasmonic metasurfaces. It is illustrated using medium-energy free-electron injection to generate highly-directional visible to near-infrared light beams, at selected wavelengths in prescribed azimuthal and polar directions, with brightness two orders of magnitude higher than that from an unstructured surface, and vortex beams with topological charge up to ten. Such emitters, with micron-scale dimensions and the freedom to fully control radiation parameters, offer novel applications in nano-spectroscopy, nano-chemistry and sensing.

  12. Insertion devices at the Swiss Light Source (phase I)

    CERN Document Server

    Schmidt, T; Imhof, A; Patterson, B D; Patthey, L; Quitmann, C; Schulze-Briese, C; Abela, R

    2001-01-01

    The insertion devices under construction for phase I of the Swiss Light Source (SLS) are described. Five undulators and one wiggler will be installed in four straight sections of the third generation 2.4 GeV SLS storage ring, under construction at the Paul Scherrer Institute. To provide undulator radiation in the energy range from 10 eV to 18 keV, both long period and short period, small gap undulators will be installed.

  13. Circular dichroism beamline B23 at the Diamond Light Source.

    Science.gov (United States)

    Hussain, Rohanah; Jávorfi, Tamás; Siligardi, Giuliano

    2012-01-01

    Synchrotron radiation circular dichroism (SRCD) is a well established technique in structural biology. The first UV-VIS beamline, dedicated to circular dichroism, at Diamond Light Source Ltd, a third-generation synchrotron facility in south Oxfordshire, UK, has recently become operational and it is now available for the user community. Herein the main characteristics of the B23 SRCD beamline, the ancillary facilities available for users, and some of the recent advances achieved are summarized.

  14. Plasma-based EUV light source

    Science.gov (United States)

    Shumlak, Uri; Golingo, Raymond; Nelson, Brian A.

    2010-11-02

    Various mechanisms are provided relating to plasma-based light source that may be used for lithography as well as other applications. For example, a device is disclosed for producing extreme ultraviolet (EUV) light based on a sheared plasma flow. The device can produce a plasma pinch that can last several orders of magnitude longer than what is typically sustained in a Z-pinch, thus enabling the device to provide more power output than what has been hitherto predicted in theory or attained in practice. Such power output may be used in a lithography system for manufacturing integrated circuits, enabling the use of EUV wavelengths on the order of about 13.5 nm. Lastly, the process of manufacturing such a plasma pinch is discussed, where the process includes providing a sheared flow of plasma in order to stabilize it for long periods of time.

  15. Chemical Dynamics at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Baer, T.; Berrah, N.; Fadley, C.; Moore, C.B.; Neumark, D.M.; Ng, C.Y.; Ruscic, B.; Smith, N.V.; Suits, A.G.; Wodtke, A.M.

    1999-02-02

    A day-long retreat was held January 15, 1999 to chart the future directions for chemical dynamics studies at the Advanced Light Source. This represents an important period for the Chemical Dynamics Beamline, as the hardware is well-developed, most of the initial experimental objectives have been realized and the mission is now to identify the future scientific priorities for the beamline and attract users of the highest caliber. To this end, we have developed a detailed scientific program for the near term; identified and prioritized the long range scientific opportunities, identified essential new hardware, and outlined an aggressive outreach program to involve the chemical physics community.

  16. Fundamentals of light sources and lasers

    CERN Document Server

    Csele, Mark

    2011-01-01

    A comprehensive introduction to the burgeoning field of photonicsThe field of photonics is finding increasing applications across a broad range of industries. While many other books provide an overview of the subject, Fundamentals of Light Sources and Lasers closes a clear gap in the current literature by concentrating on the principles of laser operation as well as providing coverage of important concepts necessary to fully understand the principles involved. The scope of the book includes everything a professional needs to get up to speed in the field, as well as all the material necessa

  17. Status of the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Galayda, John N.; /SLAC

    2011-11-04

    The Linac Coherent Light Source (LCLS) is a free electron laser facility in construction at Stanford Linear Accelerator Center. It is designed to operate in the wavelength range 0.15-1.5 nanometers. At the time of this conference, civil construction of new tunnels and buildings is complete, the necessary modifications to the SLAC linac are complete, and the undulator system and x-ray optics/diagnostics are being installed. The electron gun, 135 MeV injector linac and 250 MeV bunch compressor were commissioned in 2007. Accelerator commissioning activities are presently devoted to the achievement of performance goals for the completed 14 GeV linac.

  18. Coded source imaging simulation with visible light

    Science.gov (United States)

    Wang, Sheng; Zou, Yubin; Zhang, Xueshuang; Lu, Yuanrong; Guo, Zhiyu

    2011-09-01

    A coded source could increase the neutron flux with high L/ D ratio. It may benefit a neutron imaging system with low yield neutron source. Visible light CSI experiments were carried out to test the physical design and reconstruction algorithm. We used a non-mosaic Modified Uniformly Redundant Array (MURA) mask to project the shadow of black/white samples on a screen. A cooled-CCD camera was used to record the image on the screen. Different mask sizes and amplification factors were tested. The correlation, Wiener filter deconvolution and Richardson-Lucy maximum likelihood iteration algorithm were employed to reconstruct the object imaging from the original projection. The results show that CSI can benefit the low flux neutron imaging with high background noise.

  19. A novel amblyopia treatment system based on LED light source

    Science.gov (United States)

    Zhang, Xiaoqing; Chen, Qingshan; Wang, Xiaoling

    2011-05-01

    A novel LED (light emitting diode) light source of five different colors (white, red, green, blue and yellow) is adopted instead of conventional incandescent lamps for an amblyopia treatment system and seven training methods for rectifying amblyopia are incorporated so as for achieving an integrated therapy. The LED light source is designed to provide uniform illumination, adjustable light intensity and alterable colors. Experimental tests indicate that the LED light source operates steadily and fulfills the technical demand of amblyopia treatment.

  20. PREFACE: Diagnostics for electrical discharge light sources: pushing the limits Diagnostics for electrical discharge light sources: pushing the limits

    Science.gov (United States)

    Zissis, Georges; Haverlag, Marco

    2010-06-01

    Light sources play an indispensable role in the daily life of any human being. Quality of life, health and urban security related to traffic and crime prevention depend on light and on its quality. In fact, every day approximately 30 billion electric light sources operate worldwide. These electric light sources consume almost 19% of worldwide electricity production. Finding new ways to light lamps is a challenge where the stakes are scientific, technological, economic and environmental. The production of more efficient light sources is a sustainable solution for humanity. There are many opportunities for not only enhancing the efficiency and reliability of lighting systems but also for improving the quality of light as seen by the end user. This is possible through intelligent use of new technologies, deep scientific understanding of the operating principles of light sources and knowledge of the varied human requirements for different types of lighting in different settings. A revolution in the domain of light source technology is on the way: high brightness light emitting diodes arriving in the general lighting market, together with organic LEDs (OLEDs), are producing spectacular advances. However, unlike incandescence, electrical discharge lamps are far from disappearing from the market. In addition, new generations of discharge lamps based on molecular radiators are becoming a reality. There are still many scientific and technological challenges to be raised in this direction. Diagnostics are important for understanding the fundamental mechanisms taking place in the discharge plasma. This understanding is an absolute necessity for system optimization leading to more efficient and high quality light sources. The studied medium is rather complex, but new diagnostic techniques coupled to innovative ideas and powerful tools have been developed in recent years. This cluster issue of seven papers illustrates these efforts. The selected papers cover all domains, from

  1. Infrasound Generation from the Source Physics Experiments

    Science.gov (United States)

    Preston, L. A.; Schramm, K. A.; Jones, K. R.

    2015-12-01

    Understanding the acoustic and infrasound source generation mechanisms from underground explosions is of great importance for usage of this unique data type in non-proliferation activities. One of the purposes of the Source Physics Experiments (SPE), a series of underground explosive shots at the Nevada National Security Site (NNSS), is to gain an improved understanding of the generation and propagation of physical signals, such as seismic and infrasound, from the near to far field. Two of the SPE shots (SPE-1 and SPE-4') were designed to be small "Green's Function" sources with minimal spall or permanent surface deformation. We analyze infrasound data collected from these two shots at distances from ~300 m to ~1 km and frequencies up to 20 Hz. Using weather models based upon actual observations at the times of these sources, including 3-D variations in topography, temperatures, pressures, and winds, we synthesized full waveforms using Sandia's moving media acoustic propagation simulation suite. Several source mechanisms were simulated and compared and contrasted with observed waveforms using full waveform source inversion. We will discuss results of these source inversions including the relative roll of spall from these small explosions. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  2. Acoustic source for generating an acoustic beam

    Energy Technology Data Exchange (ETDEWEB)

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

    2016-05-31

    An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

  3. Intensity noise and spontaneous emission coupling in superluminescent light sources

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, H.F. (Dept. of Electrical Engineering, Texas A and M Univ., College Station, TX (US))

    1990-01-01

    A simple expression for the noise in the photocurrent generated by the detection of light from an ideal superluminescent source is derived using a quantum amplifier model. The excess noise factor {ital X} is found to be related to the photocurrent {ital I{sub d}}, electronic charge, {ital e}, spontaneous emission coupling factor {ital K}, and full width at half maximum power of the emission spectrum {Delta}{ital v}{sub 1/2} by the expression {ital X} = 0.664 {ital I{sub d}/eK}{Delta}{ital v}{sub 1/2}. Implications of this result for the performance of fiberoptic gyroscopes using superluminescent diode (SLD) light sources and for the design of low-noise SLD's are discussed.

  4. X-ray detectors at the Linac Coherent Light Source.

    Science.gov (United States)

    Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; Carron, Sebastian; Dragone, Angelo; Freytag, Dietrich; Haller, Gunther; Hart, Philip; Hasi, Jasmine; Herbst, Ryan; Herrmann, Sven; Kenney, Chris; Markovic, Bojan; Nishimura, Kurtis; Osier, Shawn; Pines, Jack; Reese, Benjamin; Segal, Julie; Tomada, Astrid; Weaver, Matt

    2015-05-01

    Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a new generation of cameras under development at SLAC, is introduced.

  5. Energy Recovery Linacs for Light Source Applications

    Energy Technology Data Exchange (ETDEWEB)

    George Neil

    2011-04-01

    Energy Recovery Linacs are being considered for applications in present and future light sources. ERLs take advantage of the continuous operation of superconducting rf cavities to accelerate high average current beams with low losses. The electrons can be directed through bends, undulators, and wigglers for high brightness x ray production. They are then decelerated to low energy, recovering power so as to minimize the required rf drive and electrical draw. When this approach is coupled with advanced continuous wave injectors, very high power, ultra-short electron pulse trains of very high brightness can be achieved. This paper will review the status of worldwide programs and discuss the technology challenges to provide such beams for photon production.

  6. Nonclassical light sources for silicon photonics

    Science.gov (United States)

    Bajoni, Daniele; Galli, Matteo

    2017-09-01

    Quantum photonics has recently attracted a lot of attention for its disruptive potential in emerging technologies like quantum cryptography, quantum communication and quantum computing. Driven by the impressive development in nanofabrication technologies and nanoscale engineering, silicon photonics has rapidly become the platform of choice for on-chip integration of high performing photonic devices, now extending their functionalities towards quantum-based applications. Focusing on quantum Information Technology (qIT) as a key application area, we review recent progress in integrated silicon-based sources of nonclassical states of light. We assess the state of the art in this growing field and highlight the challenges that need to be overcome to make quantum photonics a reliable and widespread technology.

  7. LED intense headband light source for fingerprint analysis

    Energy Technology Data Exchange (ETDEWEB)

    Villa-Aleman, Eliel

    2005-03-08

    A portable, lightweight and high-intensity light source for detecting and analyzing fingerprints during field investigation. On-site field analysis requires long hours of mobile analysis. In one embodiment, the present invention comprises a plurality of light emitting diodes; a power source; and a personal attachment means; wherein the light emitting diodes are powered by the power source, and wherein the power source and the light emitting diodes are attached to the personal attachment means to produce a personal light source for on-site analysis of latent fingerprints. The present invention is available for other applications as well.

  8. LED intense headband light source for fingerprint analysis

    Science.gov (United States)

    Villa-Aleman, Eliel

    2005-03-08

    A portable, lightweight and high-intensity light source for detecting and analyzing fingerprints during field investigation. On-site field analysis requires long hours of mobile analysis. In one embodiment, the present invention comprises a plurality of light emitting diodes; a power source; and a personal attachment means; wherein the light emitting diodes are powered by the power source, and wherein the power source and the light emitting diodes are attached to the personal attachment means to produce a personal light source for on-site analysis of latent fingerprints. The present invention is available for other applications as well.

  9. Generating Selected Color using RGB, Auxiliary Lights, and Simplex Search

    Directory of Open Access Journals (Sweden)

    Kim HyungTae

    2015-01-01

    Full Text Available A mixed light source generates various colors, with the potential to adjust intensities of multiple LEDs, which makes it possible to generate arbitrary colors. Currently, PCs and OSs provide color selection windows that can obtain the RGB or HSL color coordinates of a user’s selection. Mixed light sources are usually composed of LEDs in the primary colors, with LEDs in auxiliary colors such as white and yellow used in a few cases. When using auxiliary color LEDs, the number of LED inputs, the dimming levels, is larger than the number of elements in the color coordinate, which causes an under-determined problem. This study proposed how to determine the dimming levels of LEDs based on the selected color. Commercial LEDs have di_erent optical power values and impure color coordinates, even if they are RGB. Hence, the characteristics of the LEDs were described using a linear model derived from the tri-stimulus values (an XYZ color coordinate model and dimming levels. Color mixing models were derived for the arbitrary number of auxiliary color LEDs. The under-determined problem was solved using a simplex search method without an inverse matrix operation. The proposed method can be applied to a machine vision system and an RGBW light mixer for semiconductor inspection. The dimming levels, obtained using the proposed method were better than derived using other methods.

  10. Spectral design of new dynamic LED light sources

    DEFF Research Database (Denmark)

    Thorseth, Anders

    The use of LED technology in lighting applications, termed Solid State Lighting, is increasing drastically these years due to increasing flux and efficiency of LED components. The advantages of using Solid State Lighting is not only energy savings but the possibility to create new dynamic light...... sources that can be varied in color temperature and achieving color rendering properties. New LED light sources are constructed as clusters of colored LEDs. Modeling and optimization of the control of the light from the individual LEDs is a necessity for the desired operation of the new dynamic light...... source. Detailed knowledge of the spectral power distribution as a function of operating current and temperature is required for the modeling and optimization. Examples of new high color quality dynamic white light sources that can be tuned from warm white light at 2700 K to cold white light at 6500 K...

  11. Hollow-Cathode Source Generates Plasma

    Science.gov (United States)

    Deininger, W. D.; Aston, G.; Pless, L. C.

    1989-01-01

    Device generates argon, krypton, or xenon plasma via thermionic emission and electrical discharge within hollow cathode and ejects plasma into surrounding vacuum. Goes from cold start up to full operation in less than 5 s after initial application of power. Exposed to moist air between operations without significant degradation of starting and running characteristics. Plasma generated by electrical discharge in cathode barrel sustained and aided by thermionic emission from emitter tube. Emitter tube does not depend on rare-earth oxides, making it vulnerable to contamination by exposure to atmosphere. Device modified for use as source of plasma in laboratory experiments or industrial processes.

  12. The Sun: the Earth light source

    Science.gov (United States)

    Berrilli, Francesco; Giovannelli, Luca; Del Moro, Dario; Piazzesi, Roberto; Catena, Liu` Maria; Amicucci, Giordano; Vittorio, Nicola

    2015-04-01

    We have implemented at Department of Physics of University of Rome Tor Vergata a project called "The Sun: the Earth light source". The project obtained the official endorsement from the IAU Executive Committee Working Group for the International Year of Light. The project, specifically designed for high school students, is focused on the "scientific" study of Sun light by means of a complete acquisition system based on "on the shelf" appropriately CMOS low-cost sensor with free control s/w and self-assembled telescopes. The project (hereafter stage) plan is based on a course of two weeks (60 hours in total). The course contains 20 hours of theoretical lectures, necessary to learn basics about Sun, optics, telescopes and image sensors, and 40 hours of laboratory. During the course, scientists and astronomers share with high schools students, work activities in real research laboratories. High schools teachers are intensely involved in the project. Their role is to share activities with university teachers and realize outreach actions in the home institutions. Simultaneously, they are introduced to innovative teaching methods and the project in this way is regarded as a professional development course. Sun light analysis and Sun-Earth connection through light are the main scientific topics of this project. The laboratory section of the stage is executed in two phases (weeks): First phase aims are the realization of a keplerian telescope and low-cost acquisition system. During this week students are introduced to astronomical techniques used to safety collect and acquire solar light; Second phase aims is the realization of a low-cost instrument to analyse sunlight extracting information about the solar spectrum, solar irradiance and Sun-Earth connection. The proposed stage has been already tested in Italy reached the fifth edition in 2014. Since 2010, the project has been a cornerstone outreach program of the University of Rome Tor Vergata, the Italian Ministry of

  13. LIGHT SOURCE: TW Laser system for Thomson scattering X-ray light source at Tsinghua University

    Science.gov (United States)

    Yan, Li-Xm; Du, Ying-Chao; Du, Qiang; Li, Ren-Kai; Hua, Jian-Fei; Huang, Wen-Hui; Tang, Chuan-Xiang

    2009-06-01

    A TW (Tera Watt) laser system based on Ti:sapphire mainly for the Tsinghua Thomson scattering X-ray light source (TTX) is being built. Both UV (ultraviolet) laser pulse for driving the photocathode radio-frequency (RF) gun and the IR (infrared) laser pulse as the electron-beam-scattered-light are provided by the system. Efforts have also been made in laser pulse shaping and laser beam transport to optimize the high-brightness electron beam production by the photocathode RF gun.

  14. Harmonic sextupoles for the Advanced Light Source low emittance upgrade

    Science.gov (United States)

    Madur, A.; Arbelaez, D.; Marks, S.; Prestemon, S.; Robin, D.; Schlueter, R.; Steier, C.; Wan, W.

    2011-09-01

    The Advanced Light Source is a 3rd generation light source in operation since 1993. This light source is providing state of the art performance to more than 40 beamlines and their users thanks to the upgrades that have been completed over the last few years. Higher photon beam brightness is expected to become available to users in the near future through a new upgrade with the introduction of 48 sextupoles in the ALS lattice. Introducing new combined function magnets in an existing storage ring is a challenge due to the limited space available and a balance had to be found between magnet performance and spatial constraints. Moreover, the existing steering magnets will be replaced by the harmonic sextupoles. Therefore predicting the hysteresis behavior of the harmonic sextupole steering functions became critical for those included in the fast-orbit feedback loop (22 of them). After a brief introduction to the motivation for the upgrade and the scope of the project, we develop in this paper the different constraints driving the three required combined function magnet designs as well as their expected performance.

  15. Renewable Energy Sources for Electricity Generation

    OpenAIRE

    Norrga, Staffan; Stridh, Bengt; Meier, Stephan; Nee, Hans-Peter

    2012-01-01

    The use of conventional energy sources for electricity generation, such as fossil fuel combustion and nuclear power, is questioned because of environmental and safety issues and concerns about possible anthropogenic climate change. This has led to rapid developments in the field of renewable energy exploitation. Entire new fast-growing industries are formed to supply equipment for renewable power plants. The contribution from Swedish industry to this development has so far largely been limite...

  16. Source Code Generator Based on Dynamic Frames

    Directory of Open Access Journals (Sweden)

    Danijel Radošević

    2011-06-01

    Full Text Available Normal 0 21 false false false HR X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Obična tablica"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} This paper presents the model of source code generator based on dynamic frames. The model is named as the SCT model because if its three basic components: Specification (S, which describes the application characteristics, Configuration (C, which describes the rules for building applications, and Templates (T, which refer to application building blocks. The process of code generation dynamically creates XML frames containing all building elements (S, C ant T until final code is produced. This approach is compared to existing XVCL frames based model for source code generating. The SCT model is described by both XML syntax and the appropriate graphical elements. The SCT model is aimed to build complete applications, not just skeletons. The main advantages of the presented model are its textual and graphic description, a fully configurable generator, and the reduced overhead of the generated source code. The presented SCT model is shown on development of web application example in order to demonstrate its features and justify our design choices.

  17. Linac Coherent Light Source (LCLS) Design Study Report

    Energy Technology Data Exchange (ETDEWEB)

    Cornacchia, Massimo

    1998-12-04

    The Stanford Linear Accelerator Center, in collaboration with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, is proposing to build a Free-Electron-Laser (FEL) R and D facility operating in the wavelength range 1.5-15 {angstrom}. This FEL, called the ''Linac Coherent Light Source'' (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. Starting in FY 1998, the first two-thirds of the SLAC linac will be used for injection into the B factory. This leaves the last one-third free for acceleration to 15 GeV. The LCLS takes advantage of this opportunity, opening the way for the next generation of synchrotron light sources with largely proven technology and cost effective methods. This proposal is consistent with the recommendations of the Report of the Basic Energy Sciences Advisory Committee (Synchrotron Radiation Light Source Working Group, October 18-19, 1997). The report recognizes that ''fourth-generation x-ray sources...will in all likelihood be based on the free electron laser concepts. If successful, this technology could yield improvements in brightness by many orders of magnitude.'' This Design Study, the authors believe, confirms the feasibility of constructing an x-ray FEL based on the SLAC linac. Although this design is based on a consistent and feasible set of parameters, some components require more research and development to guarantee the performance. Given appropriate funding, this R and D phase can be completed in 2 years.

  18. The Jefferson Lab High Power Light Source

    Energy Technology Data Exchange (ETDEWEB)

    James R. Boyce

    2006-01-01

    Jefferson Lab has designed, built and operated two high average power free-electron lasers (FEL) using superconducting RF (SRF) technology and energy recovery techniques. Between 1999-2001 Jefferson Lab operated the IR Demo FEL. This device produced over 2 kW in the mid-infrared, in addition to producing world record average powers in the visible (50 W), ultraviolet (10 W) and terahertz range (50 W) for tunable, short-pulse (< ps) light. This FEL was the first high power demonstration of an accelerator configuration that is being exploited for a number of new accelerator-driven light source facilities that are currently under design or construction. The driver accelerator for the IR Demo FEL uses an Energy Recovered Linac (ERL) configuration that improves the energy efficiency and lowers both the capital and operating cost of such devices by recovering most of the power in the spent electron beam after optical power is extracted from the beam. The IR Demo FEL was de-commissioned in late 2001 for an upgraded FEL for extending the IR power to over 10 kW and the ultraviolet power to over 1 kW. The FEL Upgrade achieved 10 kW of average power in the mid-IR (6 microns) in July of 2004, and its IR operation currently is being extended down to 1 micron. In addition, we have demonstrated the capability of on/off cycling and recovering over a megawatt of electron beam power without diminishing machine performance. A complementary UV FEL will come on-line within the next year. This paper presents a summary of the FEL characteristics, user community accomplishments with the IR Demo, and planned user experiments.

  19. Producing Terahertz Conherent Synchrotron Radiation Based On Hefei Light Source

    CERN Document Server

    De-Rong, Xu; Yan, Shao

    2014-01-01

    This paper theoretically proves that an electron storage ring can generate coherent radiation in 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. We calculate the radiation spectral distribution from the wavy bunch in Hefei Light Source(HLS). If we reduce electron energy to 400MeV, it can produce extremely strong coherent synchrotron radiation(CSR) at 0.115THz.

  20. Satellite-Mounted Light Sources as Photometric Calibration Standards

    CERN Document Server

    Albert, Justin; Battat, James; Dupuis, Grace; Fransham, Kyle; Koopmans, Kristin; Jarrett, Michael

    2009-01-01

    A significant and growing portion of systematic error on a number of fundamental parameters in astrophysics and cosmology is due to uncertainties from absolute photometric and flux standards. A path toward achieving major reduction in such uncertainties may be provided by satellite-mounted light sources, resulting in improvement in the ability to precisely characterize atmospheric extinction, and thus helping to usher in the coming generation of precision results in astronomy. Toward this end, we have performed a campaign of observations of the 532 nm pulsed laser aboard the CALIPSO satellite, using a portable network of cameras and photodiodes, to precisely measure atmospheric extinction.

  1. Features of the type Ⅲ-like source rock and its generated natural gas

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The mother matter of Ordovician source are mainly sapropelic and generate oil in mature stage, since the high plants did not appear in Ordovician period, which is well known by internal and external scholars. Now we find a kind of Orodovician source rock generating mainly light oil and gas in mature stage during appraising source rocks in the Tarim Basin. The organic matters of this source rock are chiefly constructed by benthic brown algae in organisms (showing as macro algae), and are similar to humic source in hydrocarbon generation. The natural gas generated by this kind of source matters is obviously different from the sapropelic gas.

  2. Speckles generated by skewed, short-coherence light beams

    CERN Document Server

    Brogioli, D; Croccolo, F; Ziano, R; Mantegazza, F

    2011-01-01

    When a coherent laser beam impinges on a random sample (e.g. a colloidal suspension), the scattered light exhibits characteristic speckles. If the temporal coherence of the light source is too short, then the speckles disappear, along with the possibility of performing homodyne or heterodyne scattering detection or photon correlation spectroscopy. Here we investigate the scattering of a so-called "skewed coherence beam", i.e., a short-coherence beam modified such that the field is coherent within slabs that are skewed with respect to the wave fronts. We show that such a beam generates speckles and can be used for heterodyne scattering detection, despite its short temporal coherence. When applied to quite turbid samples, the technique has the remarkable advantage of suppressing the multiple scattering contribution of the scattering signal. The phenomenon presented here represents a very effective method for measuring the coherence skewness of either a continuous wave or a pulsed beam. Another field of applicat...

  3. LIGHT SOURCE: Conceptual design of Hefei Advanced Light Source (HALS) injection system

    Science.gov (United States)

    Zhang, Shan-Cai; Wang, Lin; Feng, Guang-Yao; Wu, Cong-Feng; Li, Wei-Min; Xu, Hong-Liang; Liu, Zu-Ping

    2009-06-01

    The Hefei Advanced Light Source(HALS) is a super low emittance storage ring and has a very short beam life time. In order to run the ring stablely, top-up injection will be necessary. The injection system will greatly affect the quality of beam. This article first gives a physics design of the injecting system. Then the injecting system is tracked under different errors. The responses of storage beam and injecting beam are given in the article.

  4. National Synchrotron Light Source 2010 Activity Report

    Energy Technology Data Exchange (ETDEWEB)

    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

  5. Study and Application of Foreign Gaseous Tritium Light Sources

    Institute of Scientific and Technical Information of China (English)

    DENG; Bei; LI; Si-jie; ZHANG; Li-feng; SUN; Yu-hua; HAN; Shi-quan

    2013-01-01

    Light is given out by the phosphor material which is excited by theβrays from tritium,as is the way tritium light sources work.For tritium light sources,there is no need for maintenance and additional power,and it is not affected by temperature,humidity,altitude and use technology,which makes it widely used in some special areas of national economy,just like the sight lighting of varieties of instrument panel,

  6. A squeezed light source operated under high vacuum

    Science.gov (United States)

    Wade, Andrew R.; Mansell, Georgia L.; Chua, Sheon S. Y.; Ward, Robert L.; Slagmolen, Bram J. J.; Shaddock, Daniel A.; McClelland, David E.

    2015-01-01

    Non-classical squeezed states of light are becoming increasingly important to a range of metrology and other quantum optics applications in cryptography, quantum computation and biophysics. Applications such as improving the sensitivity of advanced gravitational wave detectors and the development of space-based metrology and quantum networks will require robust deployable vacuum-compatible sources. To date non-linear photonics devices operated under high vacuum have been simple single pass systems, testing harmonic generation and the production of classically correlated photon pairs for space-based applications. Here we demonstrate the production under high-vacuum conditions of non-classical squeezed light with an observed 8.6 dB of quantum noise reduction down to 10 Hz. Demonstration of a resonant non-linear optical device, for the generation of squeezed light under vacuum, paves the way to fully exploit the advantages of in-vacuum operations, adapting this technology for deployment into new extreme environments. PMID:26657616

  7. Generating artificial light curves: Revisited and updated

    CERN Document Server

    Emmanoulopoulos, D; Papadakis, I E

    2013-01-01

    The production of artificial light curves with known statistical and variability properties is of great importance in astrophysics. Consolidating the confidence levels during cross-correlation studies, understanding the artefacts induced by sampling irregularities, establishing detection limits for future observatories are just some of the applications of simulated data sets. Currently, the widely used methodology of amplitude and phase randomisation is able to produce artificial light curves which have a given underlying power spectral density (PSD) but which are strictly Gaussian distributed. This restriction is a significant limitation, since the majority of the light curves e.g. active galactic nuclei, X-ray binaries, gamma-ray bursts show strong deviations from Gaussianity exhibiting `burst-like' events in their light curves yielding long-tailed probability distribution functions (PDFs). In this study we propose a simple method which is able to precisely reproduce light curves which match both the PSD an...

  8. Suppression of microbunching instability in the linac coherent light source

    Directory of Open Access Journals (Sweden)

    Z. Huang

    2004-07-01

    Full Text Available A microbunching instability driven by longitudinal space charge, coherent synchrotron radiation, and linac wakefields is studied for the linac coherent light source (LCLS accelerator system. Since the uncorrelated (local energy spread of electron beams generated from a photocathode rf gun is very small, the microbunching gain may be large enough to significantly amplify rf-gun generated modulations or even shot-noise fluctuations of the electron beam. The uncorrelated energy spread can be increased by an order of magnitude to provide strong Landau damping against the instability without degrading the free-electron laser performance. We study different damping options in the LCLS and discuss an effective laser heater to minimize the impact of the instability on the quality of the electron beam.

  9. Suppression of Microbunching Instability in the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z

    2004-03-02

    A microbunching instability driven by longitudinal space charge, coherent synchrotron radiation, and linac wakefields is studied for the linac coherent light source (LCLS) accelerator system. Since the uncorrelated (local) energy spread of electron beams generated from a photocathode rf gun is very small, the microbunching gain may be large enough to significantly amplify rf-gun generated modulations or even shot-noise fluctuations of the electron beam. The uncorrelated energy spread can be increased by an order of magnitude to provide strong Landau damping against the instability without degrading the free-electron laser performance. We study different damping options in the LCLS and discuss an effective laser heater to minimize the impact of the instability on the quality of the electron beam.

  10. A new type of white light-emitting diode light source basing on fluorescent SiC

    DEFF Research Database (Denmark)

    Ou, Haiyan; Ou, Yiyu; Lu, Weifang

    Most of the commercial white light-emitting diode (LED) light sources are made from phosphor coated blue-emitting gallium nitride (GaN) chips. This type white LED light source always has tradeoff between luminous efficacy and color rendering index (CRI). Furthermore, yellow-emitting phosphor decays...... much faster than the semiconductor chip, so the white color will turn into bluish over the time. This paper will propose a new type white LED light source: using fluorescent silicon carbide (SiC) to take the place of phosphor. This new type LED has the following advantages: a) SiC is a wide bandgap...... semiconductor material , so it is stable; b) Fluorescent SiC has very wide emission spectrum, and it could generate white light with very high CRI; c) It is a better substrate than sapphire for the GaN growth in terms of lattice match and thermal conductivity. This paper will cover: the growth of fluorescent Si...

  11. BWR Source Term Generation and Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    J.C. Ryman

    2003-07-31

    This calculation is a revision of a previous calculation (Ref. 7.5) that bears the same title and has the document identifier BBAC00000-01717-0210-00006 REV 01. The purpose of this revision is to remove TBV (to-be-verified) -41 10 associated with the output files of the previous version (Ref. 7.30). The purpose of this and the previous calculation is to generate source terms for a representative boiling water reactor (BWR) spent nuclear fuel (SNF) assembly for the first one million years after the SNF is discharged from the reactors. This calculation includes an examination of several ways to represent BWR assemblies and operating conditions in SAS2H in order to quantify the effects these representations may have on source terms. These source terms provide information characterizing the neutron and gamma spectra in particles per second, the decay heat in watts, and radionuclide inventories in curies. Source terms are generated for a range of burnups and enrichments (see Table 2) that are representative of the waste stream and stainless steel (SS) clad assemblies. During this revision, it was determined that the burnups used for the computer runs of the previous revision were actually about 1.7% less than the stated, or nominal, burnups. See Section 6.6 for a discussion of how to account for this effect before using any source terms from this calculation. The source term due to the activation of corrosion products deposited on the surfaces of the assembly from the coolant is also calculated. The results of this calculation support many areas of the Monitored Geologic Repository (MGR), which include thermal evaluation, radiation dose determination, radiological safety analyses, surface and subsurface facility designs, and total system performance assessment. This includes MGR items classified as Quality Level 1, for example, the Uncanistered Spent Nuclear Fuel Disposal Container (Ref. 7.27, page 7). Therefore, this calculation is subject to the requirements of the

  12. Behavior of Layers under Different Light Sources

    OpenAIRE

    2015-01-01

    ABSTRACT Light is an important factor in the management of laying poultry. The ideal lamp spectrum that provides the best welfare conditions still needs to be determined. Wavelength and light intensity influence poultry behavior and their welfare. This study evaluated the influence of four lamps types with different light spectra on the behavior of seventy 52-week laying hens. Incandescent, fluorescent, and sodium and mercury vapor lamps were set in a different poultry house each and supplied...

  13. Circuit Simulation of Light Ⅱ-A Pulsed Power Generator

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The Light Ⅱ-A pulsed power generator could be divided into the following parts, a Marx generator consisting of 12 spark gap switches and 24 low inductance capacitors (Maxwell Corporation products)

  14. Penning plasma based simultaneous light emission source of visible and VUV lights

    Science.gov (United States)

    Vyas, G. L.; Prakash, R.; Pal, U. N.; Manchanda, R.; Halder, N.

    2016-06-01

    In this paper, a laboratory-based penning plasma discharge source is reported which has been developed in two anode configurations and is able to produce visible and VUV lights simultaneously. The developed source has simultaneous diagnostics facility using Langmuir probe and optical emission spectroscopy. The two anode configurations, namely, double ring and rectangular configurations, have been studied and compared for optimum use of the geometry for efficient light emissions and recording. The plasma is produced using helium gas and admixture of three noble gases including helium, neon, and argon. The source is capable to produce eight spectral lines for pure helium in the VUV range from 20 to 60 nm and total 24 spectral lines covering the wavelength range 20-106 nm for the admixture of gases. The large range of VUV lines is generated from gaseous admixture rather from the sputtered materials. The recorded spectrum shows that the plasma light radiations in both visible and VUV range are larger in double ring configuration than that of the rectangular configurations at the same discharge operating conditions. To clearly understand the difference, the imaging of the discharge using ICCD camera and particle-in-cell simulation using VORPAL have also been carried out. The effect of ion diffusion, metastable collision with the anode wall and the nonlinear effects are correlated to explain the results.

  15. Penning plasma based simultaneous light emission source of visible and VUV lights

    Energy Technology Data Exchange (ETDEWEB)

    Vyas, G. L., E-mail: glvyas27@gmail.com [Manipal University Jaipur (India); Prakash, R.; Pal, U. N. [CSIR-Central Electronics and Engineering Research Institute, Microwave Tubes Division (India); Manchanda, R. [Institute for Plasma Research (India); Halder, N. [Manipal University Jaipur (India)

    2016-06-15

    In this paper, a laboratory-based penning plasma discharge source is reported which has been developed in two anode configurations and is able to produce visible and VUV lights simultaneously. The developed source has simultaneous diagnostics facility using Langmuir probe and optical emission spectroscopy. The two anode configurations, namely, double ring and rectangular configurations, have been studied and compared for optimum use of the geometry for efficient light emissions and recording. The plasma is produced using helium gas and admixture of three noble gases including helium, neon, and argon. The source is capable to produce eight spectral lines for pure helium in the VUV range from 20 to 60 nm and total 24 spectral lines covering the wavelength range 20–106 nm for the admixture of gases. The large range of VUV lines is generated from gaseous admixture rather from the sputtered materials. The recorded spectrum shows that the plasma light radiations in both visible and VUV range are larger in double ring configuration than that of the rectangular configurations at the same discharge operating conditions. To clearly understand the difference, the imaging of the discharge using ICCD camera and particle-in-cell simulation using VORPAL have also been carried out. The effect of ion diffusion, metastable collision with the anode wall and the nonlinear effects are correlated to explain the results.

  16. LAT Monitored Source List Light Curves

    Data.gov (United States)

    National Aeronautics and Space Administration — The LAT team monitors flux values for a number of bright sources and transient sources that have shown flares during the mission. (See up-to-date weekly reports on...

  17. Inferred motion perception of light sources in 3D scenes is color-blind.

    Science.gov (United States)

    Gerhard, Holly E; Maloney, Laurence T

    2013-01-01

    In everyday scenes, the illuminant can vary spatially in chromaticity and luminance, and change over time (e.g. sunset). Such variation generates dramatic image effects too complex for any contemporary machine vision system to overcome, yet human observers are remarkably successful at inferring object properties separately from lighting, an ability linked with estimation and tracking of light field parameters. Which information does the visual system use to infer light field dynamics? Here, we specifically ask whether color contributes to inferred light source motion. Observers viewed 3D surfaces illuminated by an out-of-view moving collimated source (sun) and a diffuse source (sky). In half of the trials, the two sources differed in chromaticity, thereby providing more information about motion direction. Observers discriminated light motion direction above chance, and only the least sensitive observer benefited slightly from the added color information, suggesting that color plays only a very minor role for inferring light field dynamics.

  18. Inferred Motion Perception of Light Sources in 3D Scenes is Color-Blind

    Directory of Open Access Journals (Sweden)

    Holly E. Gerhard

    2013-04-01

    Full Text Available In everyday scenes, the illuminant can vary spatially in chromaticity and luminance, and change over time (e.g. sunset. Such variation generates dramatic image effects too complex for any contemporary machine vision system to overcome, yet human observers are remarkably successful at inferring object properties separately from lighting, an ability linked with estimation and tracking of light field parameters. Which information does the visual system use to infer light field dynamics? Here, we specifically ask whether color contributes to inferred light source motion. Observers viewed 3D surfaces illuminated by an out-of-view moving collimated source (sun and a diffuse source (sky. In half of the trials, the two sources differed in chromaticity, thereby providing more information about motion direction. Observers discriminated light motion direction above chance, and only the least sensitive observer benefited slightly from the added color information, suggesting that color plays only a very minor role for inferring light field dynamics.

  19. 10 CFR 39.55 - Tritium neutron generator target sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in a...

  20. Refurbishment Status of Light Ⅱ-A Pulsed Power Generator

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The Light Ⅱ-A pulsed power generator, formerly used to pump KrF laser, was updated around the year 2000 from the original Light Ⅱ, a pulsed power generator built in 1980s at CIAE. This machine was

  1. Perception of light source distance from shading patterns.

    Science.gov (United States)

    Schütt, Heiko H; Baier, Franziska; Fleming, Roland W

    2016-01-01

    Varying the distance of a light source from an object alters both the intensity and spatial distribution of surface shading patterns. We tested whether observers can use such cues to infer light source distance. Participants viewed stereoscopic renderings of rough objects with diffuse and glossy surfaces, which were illuminated by a point source at a range of distances. In one task, they adjusted the position of a small probe dot in three dimensions to report the apparent location of the light in the scene. In a second task, they adjusted the shading on one object (by moving an invisible light source) until it appeared to be illuminated from the same distance as another object. Participants' responses increased linearly with the true light source distance, suggesting that they have clear intuitions about how light source distance affects shading patterns for a variety of different surfaces. However, there were also systematic errors: Subjects overestimated light source distance in the probe adjustment task, and in both experiments, roughness and glossiness affected responses. We find the pattern of results is predicted surprisingly well by a simplistic model based only on the area of the image that exceeds a certain intensity threshold. Thus, although subjects can report light source distance, they may rely on simple--sometimes erroneous--heuristics to do so.

  2. Phosphor-Free Solid State Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nause, Jeff E; Ferguson, Ian; Doolittle, Alan

    2007-02-28

    The objective of this work was to demonstrate a light emitting diode that emitted white light without the aid of a phosphor. The device was based on the combination of a nitride LED and a fluorescing ZnO substrate. The early portion of the work focused on the growth of ZnO in undoped and doped form. The doped ZnO was successfully engineered to emit light at specific wavelengths by incorporating various dopants into the crystalline lattice. Thereafter, the focus of the work shifted to the epitaxial growth of nitride structures on ZnO. Initially, the epitaxy was accomplished with molecular beam epitaxy (MBE). Later in the program, metallorganic chemical vapor deposition (MOCVD) was successfully used to grow nitrides on ZnO. By combining the characteristics of the doped ZnO substrate with epitaxially grown nitride LED structures, a phosphor-free white light emitting diode was successfully demonstrated and characterized.

  3. Study on paper moisture measurement method by monochromatic light sources

    Science.gov (United States)

    Mo, Changtao; Du, Xin; He, Ping; Zhang, Lili; Li, Nan; Wang, Ming

    2010-10-01

    We design the emission and detection optical paths of three monochromatic infrared light sources with different wavelength. The three light sources are placed according to the different angles, so that the three kinds of monochromatic lights are converged on the same point of the sample. Using the method, we can detect the same point and improve the measurement accuracy. We choose the standard near-infrared monochromatic light source, so that we can save some equipments, such as tungsten- halogen lamp, filtered wheel, collimation focalizer, electric machine, and so on. In particular, we save the cumbersome cooling system, reduce the volume of the instrument greatly and reduce the cost. The three monochromatic light sources are supplied by the same pulse power source, to ensure their synchronous working.

  4. Field ion source development for neutron generators

    Science.gov (United States)

    Bargsten Johnson, B.; Schwoebel, P. R.; Holland, C. E.; Resnick, P. J.; Hertz, K. L.; Chichester, D. L.

    2012-01-01

    An ion source based on the principles of electrostatic field desorption is being developed to improve the performance of existing compact neutron generators. The ion source is an array of gated metal tips derived from field electron emitter array microfabrication technology. A comprehensive summary of development and experimental activities is presented. Many structural modifications to the arrays have been incorporated to achieve higher tip operating fields, while lowering fields at the gate electrode to prevent gate field electron emission which initiates electrical breakdown in the array. The latest focus of fabrication activities has been on rounding the gate electrode edge and surrounding the gate electrode with dielectric material. Array testing results have indicated a steady progression of increased array tip operating fields with each new design tested. The latest arrays have consistently achieved fields beyond those required for the onset of deuterium desorption (˜20 V/nm), and have demonstrated the desorption of deuterium at fields up to 36 V/nm. The number of ions desorbed from an array has been quantified, and field desorption of metal tip substrate material from array tips has been observed for the first time. Gas-phase field ionization studies with ˜10,000 tip arrays have achieved deuterium ion currents of ˜50 nA. Neutron production by field ionization has yielded ˜10 2 n/s from ˜1 mm 2 of array area using the deuterium-deuterium fusion reaction at 90 kV.

  5. Field ion source development for neutron generators

    Energy Technology Data Exchange (ETDEWEB)

    Bargsten Johnson, B. [University of New Mexico, Albuquerque, NM 87131 (United States); Schwoebel, P.R., E-mail: schwoebel@chtm.unm.edu [University of New Mexico, Albuquerque, NM 87131 (United States); Holland, C.E. [SRI International, Menlo Park, CA 94025 (United States); Resnick, P.J. [Sandia National Laboratories, Albuquerque, NM 87123 (United States); Hertz, K.L. [Sandia National Laboratories, Livermore, CA 94551 (United States); Chichester, D.L. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States)

    2012-01-21

    An ion source based on the principles of electrostatic field desorption is being developed to improve the performance of existing compact neutron generators. The ion source is an array of gated metal tips derived from field electron emitter array microfabrication technology. A comprehensive summary of development and experimental activities is presented. Many structural modifications to the arrays have been incorporated to achieve higher tip operating fields, while lowering fields at the gate electrode to prevent gate field electron emission which initiates electrical breakdown in the array. The latest focus of fabrication activities has been on rounding the gate electrode edge and surrounding the gate electrode with dielectric material. Array testing results have indicated a steady progression of increased array tip operating fields with each new design tested. The latest arrays have consistently achieved fields beyond those required for the onset of deuterium desorption ({approx}20 V/nm), and have demonstrated the desorption of deuterium at fields up to 36 V/nm. The number of ions desorbed from an array has been quantified, and field desorption of metal tip substrate material from array tips has been observed for the first time. Gas-phase field ionization studies with {approx}10,000 tip arrays have achieved deuterium ion currents of {approx}50 nA. Neutron production by field ionization has yielded {approx}10{sup 2} n/s from {approx}1 mm{sup 2} of array area using the deuterium-deuterium fusion reaction at 90 kV.

  6. Field Ion Source Development for Neutron Generators

    Energy Technology Data Exchange (ETDEWEB)

    B. Bargsten Johnson; P. R. Schwoebel; C. E. Holland; P. J. Resnick; K. L. Hertz; D. L. Chichester

    2012-01-01

    An ion source based on the principles of electrostatic field desorption is being developed to improve the performance of existing compact neutron generators. The ion source is an array of gated metal tips derived from field electron emitter array microfabrication technology. A comprehensive summary of development and experimental activities is presented. Many structural modifications to the arrays have been incorporated to achieve higher tip operating fields, while lowering fields at the gate electrode to prevent gate field electron emission which initiates electrical breakdown in the array. The latest focus of fabrication activities has been on rounding the gate electrode edge and surrounding the gate electrode with dielectric material. Array testing results have indicated a steady progression of increased array tip operating fields with each new design tested. The latest arrays have consistently achieved fields beyond those required for the onset of deuterium desorption ({approx}20 V/nm), and have demonstrated the desorption of deuterium at fields up to 36 V/nm. The number of ions desorbed from an array has been quantified, and field desorption of metal tip substrate material from array tips has been observed for the first time. Gas-phase field ionization studies with {approx}10,000 tip arrays have achieved deuterium ion currents of {approx}50 nA. Neutron production by field ionization has yielded {approx}10{sup 2} n/s from {approx}1 mm{sup 2} of array area using the deuterium-deuterium fusion reaction at 90 kV.

  7. SESAME -- A light source for the Middle East

    Science.gov (United States)

    Winick, Herman

    2012-02-01

    Developed under UNESCO and modelled on CERN, SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) is an international research centre in construction in Jordan, enabling world-class research while promoting peace through scientific cooperation. Its centerpiece, a new 2.5 GeV 3rd Generation Electron Storage Ring (133m circumference, 26nm-rad emittance, 12 places for insertion devices), will provide intense light from infra-red to hard X-rays. The Council (Bahrain, Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestinian Authority, Turkey), provides the annual budget. Concrete shielding is complete, and a staff of 21 is installing the refurbished 0.8 GeV BESS Y I injector system, a gift from Germany. The facility can serve 25 simultaneous experiments. Beamline equipment has been provided by Daresbury (UK), the Helmholtz Assoc. (Germany), the Swiss Light Source, LURE (France), the Univ. of Liverpool, Elettra (Italy) and US labs. Jordan has contributed 3.3M, in addition to a building and land. The EU has contributed 4.8M. Commitments confirmed by Members look set to provide most of 35M needed to complete construction of the ring and 3 beamlines. A training program has been underway since 2000. See www.sesame.org.jo

  8. Development of implantable light source for optogenetics

    Science.gov (United States)

    Rusakov, Konstantin; Radzewicz, Czesław

    2016-09-01

    The research described here aims at a design and fabrication of a light emitting module for a mobile optogenetic device for animals that are freely moving in the IntelliCage system cages. The device is designed to stimulate selected brain areas of the animal with light. The approach described here is based on a LED chip attached to the tip of a cannula which will be directly implanted into a mouse's brain. The device has been fabricated and tested in a laboratory. In addition, we have observed optogenetic effect on the slice of mice brain tissue in vitro stimulated with our implants.

  9. My Precious! The Location and Diffusion of Scientific Research: Evidence from the Synchrotron Diamond Light Source

    OpenAIRE

    2013-01-01

    We analyze the impact of the establishment of a GBP 380 million basic scientific research facility in the UK on the geographical distribution of related research. We investigate whether the siting of the Diamond Light Source, a 3rd generation synchrotron light source, in Oxfordshire induced a clustering of related research in its geographic proximity. To account for the potentially endogenous location choice of the synchrotron, we exploit the availability of a 'runner-up' site near Manchester...

  10. A new storage-ring light source

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Alex [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-06-01

    A recently proposed technique in storage ring accelerators is applied to provide potential high-power sources of photon radiation. The technique is based on the steady-state microbunching (SSMB) mechanism. As examples of this application, one may consider a high-power DUV photon source for research in atomic and molecular physics or a high-power EUV radiation source for industrial lithography. A less challenging proof-of-principle test to produce IR radiation using an existing storage ring is also considered.

  11. Light source design using Kagome-lattice hollow core photonic crystal fibers

    Science.gov (United States)

    Hossain, Md. Anwar; Namihira, Yoshinori

    2014-09-01

    Supercontinuum (SC) light source is designed using high pressure Xe-filled hollow core Kagome-lattice photonic crystal fiber. Using finite element method with perfectly matched layer, SC spectra in normal chromatic dispersion region have been generated using picosecond optical pulses from relatively less expensive laser sources.

  12. In situ calibration of a light source in a sensor device

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat; Serkland, Darwin k.; Merchant, Bion J.

    2015-12-29

    A sensor device is described herein, wherein the sensor device includes an optical measurement system, such as an interferometer. The sensor device further includes a low-power light source that is configured to emit an optical signal having a constant wavelength, wherein accuracy of a measurement output by the sensor device is dependent upon the optical signal having the constant wavelength. At least a portion of the optical signal is directed to a vapor cell, the vapor cell including an atomic species that absorbs light having the constant wavelength. A photodetector captures light that exits the vapor cell, and generates an electrical signal that is indicative of intensity of the light that exits the vapor cell. A control circuit controls operation of the light source based upon the electrical signal, such that the light source emits the optical signal with the constant wavelength.

  13. An experiment on the color rendering of different light sources

    Science.gov (United States)

    Fumagalli, Simonetta; Bonanomi, Cristian; Rizzi, Alessandro

    2013-02-01

    The color rendering index (CRI) of a light source attempts to measure how much the color appearance of objects is preserved when they are illuminated by the given light source. This problem is of great importance for various industrial and scientific fields, such as lighting architecture, design, ergonomics, etc. Usually a light source is specified through the Correlated Color Temperature or CCT. However two (or more) light sources with the same CCT but different spectral power distribution can exist. Therefore color samples viewed under two light sources with equal CCTs can appear different. Hence, the need for a method to assess the quality of a given illuminant in relation to color. Recently CRI has had a renewed interest because of the new LED-based lighting systems. They usually have a color rendering index rather low, but good preservation of color appearance and a pleasant visual appearance (visual appeal). Various attempts to develop a new color rendering index have been done so far, but still research is working for a better one. This article describes an experiment performed by human observers concerning the appearance preservation of color under some light sources, comparing it with a range of available color rendering indices.

  14. An integrated source of broadband quadrature squeezed light

    CERN Document Server

    Hoff, Ulrich B; Andersen, Ulrik L

    2015-01-01

    An integrated silicon nitride resonator is proposed as an ultra-compact source of bright single-mode quadrature squeezed light at 850 nm. Optical properties of the device are investigated and tailored through numerical simulations, with particular attention paid to loss associated with interfacing the device. An asymmetric double layer stack waveguide geometry with inverse vertical tapers is proposed for efficient and robust fibre-chip coupling, yielding a simulated total loss of -0.75 dB/facet. We assess the feasibility of the device through a full quantum noise analysis and derive the output squeezing spectrum for intra-cavity pump self-phase modulation. Subject to standard material loss and detection efficiencies, we find that the device holds promises for generating substantial quantum noise squeezing over a bandwidth exceeding 1 GHz. In the low-propagation loss regime, approximately -7 dB squeezing is predicted for a pump power of only 50 mW.

  15. A numerical experiment on light pollution from distant sources

    Science.gov (United States)

    Kocifaj, M.

    2011-08-01

    To predict the light pollution of the night-time sky realistically over any location or measuring point on the ground presents quite a difficult calculation task. Light pollution of the local atmosphere is caused by stray light, light loss or reflection of artificially illuminated ground objects or surfaces such as streets, advertisement boards or building interiors. Thus it depends on the size, shape, spatial distribution, radiative pattern and spectral characteristics of many neighbouring light sources. The actual state of the atmospheric environment and the orography of the surrounding terrain are also relevant. All of these factors together influence the spectral sky radiance/luminance in a complex manner. Knowledge of the directional behaviour of light pollution is especially important for the correct interpretation of astronomical observations. From a mathematical point of view, the light noise or veil luminance of a specific sky element is given by a superposition of scattered light beams. Theoretical models that simulate light pollution typically take into account all ground-based light sources, thus imposing great requirements on CPU and MEM. As shown in this paper, a contribution of distant sources to the light pollution might be essential under specific conditions of low turbidity and/or Garstang-like radiative patterns. To evaluate the convergence of the theoretical model, numerical experiments are made for different light sources, spectral bands and atmospheric conditions. It is shown that in the worst case the integration limit is approximately 100 km, but it can be significantly shortened for light sources with cosine-like radiative patterns.

  16. Generation of Single-Cycle Light Pulses

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, B C; Jovanovic, I; Armstrong, J P; Pyke, B; Crane, J K; Shuttlesworth, R

    2004-02-13

    Most optical pulses, even at the 10-femtosecond timescale, consist of several oscillations of the electric field. By producing and amplifying an ultra-broadband continuum, single cycle (e 3 fs) or shorter optical pulses may be generated. This requires a very challenging pulse-compression with sub-femtosecond accuracy. Production of these single-cycle pulses will lead to new generations of experiments in the areas of coherent control of chemical excitations and reactions, 0.1-fs high-order harmonic (XUV) generation for probing of materials and fast processes, and selective 3-D micron-scale material removal and modification. We activated the first stage of a planned three-stage optical parametric amplifier (OPA) that would ultimately produce sub-3 fs pulses. Active control with a learning algorithm was implemented to optimize the continuum generated in an argon-filled capillary and to control and optimize the final compressed pulse temporal shape. A collaboration was initiated to coherently control the population of different states upon dissociation of Rb{sub 2}. Except for one final optic, a pulse compressor and diagnostics were constructed to produce and characterize pulses in the 5-fs range from the first OPA stage.

  17. NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 1998.

    Energy Technology Data Exchange (ETDEWEB)

    ROTHMAN,E.

    1999-05-01

    provided 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.

  18. Twin-Mirrored-Galvanometer Laser-Light-Sheet Generator

    Science.gov (United States)

    Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

    1991-01-01

    Multiple, rotating laser-light sheets generated to illuminate flows in wind tunnels. Designed and developed to provide flexibility and adaptability to wide range of applications. Design includes capability to control size and location of laser-light sheet in real time, to generate horizontal or vertical sheets, to sweep sheet repeatedly through volume, to generate multiple sheets with controllable separation, and to rotate single or multiple laser-light sheets. Includes electronic equipment and laser mounted on adjustable-height platform. Twin-mirrored galvanometer unit supported by tripod to reduce vibration. Other possible applications include use in construction industry to align beams of building. Artistic or display applications also possible.

  19. Potential Sources of Polarized Light from a Plant Canopy

    Science.gov (United States)

    Vanderbilt, Vern; Daughtry, Craig; Dahlgren, Robert

    2016-01-01

    Field measurements have demonstrated that sunlight polarized during a first surface reflection by shiny leaves dominates the optical polarization of the light reflected by shiny-leafed plant canopies having approximately spherical leaf angle probability density functions ("Leaf Angle Distributions" - LAD). Yet for other canopies - specifically those without shiny leaves and/or spherical LADs - potential sources of optically polarized light may not always be obvious. Here we identify possible sources of polarized light within those other canopies and speculate on the ecologically important information polarization measurements of those sources might contain.

  20. The Nanohana 2 GeV Synchrotron light source

    CERN Document Server

    Korchuganov, V; Mezentsev, N A; Sajaev, Vadim; Takahashi, K; Aizawa, K; Kamiya, S; Oku, Y; Ohwaki, K

    2000-01-01

    Nanohana SR light source has been planned to be constructed in Chiba prefecture, Japan. The Nanohana is a synchrotron light source proposed for mainly industrial users. The electron storage ring has been designed to operate at injection energy of 500 MeV with a nominal energy of 2 GeV. The lattice is a Chasman-Green type with straight sections for up to six insertion devices. Several modes of operation are optimized to accommodate high-field superconducting wigglers, mini-pole undulators and VUV/SX undulators. Conceptual design of the synchrotron light source is presented.

  1. Terahertz Light Source and User Area at FACET

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Z.; Li, S.Z.; Litos, M.; Fisher, A.D.; Hogan, M.J.; /SLAC

    2011-11-08

    FACET at SLAC provides high charge, high peak current, low emittance electron beam that is bunched at THz wavelength scale during its normal operation. A THz light source based coherent transition radiation (CTR) from this beam would potentially be the brightest short-pulse THz source ever constructed. Efforts have been put into building this photon source together with a user area, to provide a platform to utilize this unique THz radiation for novel nonlinear and ultrafast phenomena researches and experiments. Being a long-time underutilized portion of the electromagnetic spectrum, terahertz (100 GHz {approx} 10 THz) spectral range is experiencing a renaissance in recent years, with broad interests from chemical and biological imaging, material science, telecommunication, semiconductor and superconductor research, etc. Nevertheless, the paucity of THz sources especially strong THz radiation hinders both its commercial applications and nonlinear processes research. FACET - Facilities for Accelerator science and Experimental Test beams at SLAC - provides 23 GeV electron beam with peak currents of {approx} 20 kA that can be focused down to 100 {mu}m{sup 2} transversely. Such an intense electron beam, when compressed to sub-picosecond longitudinal bunch length, coherently radiates high intensity EM fields well within THz frequency range that are orders of magnitude stronger than those available from laboratory tabletop THz sources, which will enable a wide variety of THz related research opportunities. Together with a description of the FACET beamline and electron beam parameters, this paper will report FACET THz radiation generation via coherent transition radiation and calculated photon yield and power spectrum. A user table is being set up along the THz radiation extraction sites, and equipped with various signal diagnostics including THz power detector, Michelson interferometer, sample stages, and sets of motorized optical components. This setup will also be

  2. X-ray Optics for BES Light Source Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Dennis [Argonne National Lab. (ANL), Argonne, IL (United States); Padmore, Howard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lessner, Eliane [Dept. of Energy (DOE), Washington DC (United States). Office of Science

    2013-03-27

    Each new generation of synchrotron radiation sources has delivered an increase in average brightness 2 to 3 orders of magnitude over the previous generation. The next evolution toward diffraction-limited storage rings will deliver another 3 orders of magnitude increase. For ultrafast experiments, free electron lasers (FELs) deliver 10 orders of magnitude higher peak brightness than storage rings. Our ability to utilize these ultrabright sources, however, is limited by our ability to focus, monochromate, and manipulate these beams with X-ray optics. X-ray optics technology unfortunately lags behind source technology and limits our ability to maximally utilize even today’s X-ray sources. With ever more powerful X-ray sources on the horizon, a new generation of X-ray optics must be developed that will allow us to fully utilize these beams of unprecedented brightness. The increasing brightness of X-ray sources will enable a new generation of measurements that could have revolutionary impact across a broad area of science, if optical systems necessary for transporting and analyzing X-rays can be perfected. The high coherent flux will facilitate new science utilizing techniques in imaging, dynamics, and ultrahigh-resolution spectroscopy. For example, zone-plate-based hard X-ray microscopes are presently used to look deeply into materials, but today’s resolution and contrast are restricted by limitations of the current lithography used to manufacture nanodiffractive optics. The large penetration length, combined in principle with very high spatial resolution, is an ideal probe of hierarchically ordered mesoscale materials, if zone-plate focusing systems can be improved. Resonant inelastic X-ray scattering (RIXS) probes a wide range of excitations in materials, from charge-transfer processes to the very soft excitations that cause the collective phenomena in correlated electronic systems. However, although RIXS can probe high-energy excitations, the most exciting and

  3. X-ray Optics for BES Light Source Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Dennis [Argonne National Lab. (ANL), Argonne, IL (United States); Padmore, Howard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lessner, Eliane [Dept. of Energy (DOE), Washington DC (United States). Office of Science

    2013-03-27

    Each new generation of synchrotron radiation sources has delivered an increase in average brightness 2 to 3 orders of magnitude over the previous generation. The next evolution toward diffraction-limited storage rings will deliver another 3 orders of magnitude increase. For ultrafast experiments, free electron lasers (FELs) deliver 10 orders of magnitude higher peak brightness than storage rings. Our ability to utilize these ultrabright sources, however, is limited by our ability to focus, monochromate, and manipulate these beams with X-ray optics. X-ray optics technology unfortunately lags behind source technology and limits our ability to maximally utilize even today’s X-ray sources. With ever more powerful X-ray sources on the horizon, a new generation of X-ray optics must be developed that will allow us to fully utilize these beams of unprecedented brightness. The increasing brightness of X-ray sources will enable a new generation of measurements that could have revolutionary impact across a broad area of science, if optical systems necessary for transporting and analyzing X-rays can be perfected. The high coherent flux will facilitate new science utilizing techniques in imaging, dynamics, and ultrahigh-resolution spectroscopy. For example, zone-plate-based hard X-ray microscopes are presently used to look deeply into materials, but today’s resolution and contrast are restricted by limitations of the current lithography used to manufacture nanodiffractive optics. The large penetration length, combined in principle with very high spatial resolution, is an ideal probe of hierarchically ordered mesoscale materials, if zone-plate focusing systems can be improved. Resonant inelastic X-ray scattering (RIXS) probes a wide range of excitations in materials, from charge-transfer processes to the very soft excitations that cause the collective phenomena in correlated electronic systems. However, although RIXS can probe high-energy excitations, the most exciting and

  4. Comparative study of energy saving light sources

    Energy Technology Data Exchange (ETDEWEB)

    Khan, N.; Abas, N. [Department of Electrical Engineering, Comsats Institute of Information technology, Park Road, Islamabad (Pakistan)

    2011-01-15

    Techno-economic performance comparison of compact fluorescent lamps (CFL) with light emitting diodes (LED), electrode less fluorescent lamps (EEFL), fluorescent tubes, incandescent bulbs, photovoltaic (PV) and fiber optic lighting systems was carried out in view of worsening power and energy crisis in Pakistan. Literature survey showed 23 W CFL, 21 W EEFL, 18 W fluorescent tube or 15 W LED lamps emit almost same quantity of luminous flux (lumens) as a standard 100 W incandescent lamp. All inclusive, operational costs of LED lamps were found 1.21, 1.62. 1.69, 6.46, 19.90 and 21.04 times lesser than fluorescent tubes, CFL, EEFL, incandescent bulbs, fiber optic solar lighting and PV systems, respectively. However, tubes, LED, CFL and EEFL lamps worsen electric power quality of low voltage networks due to high current harmonic distortions (THD) and poor power factors (PF). Fluorescent lamps emit UV and pollute environment by mercury and phosphors when broken or at end of their life cycle. Energy consumption, bio-effects, and environmental concerns prefer LED lamps over phosphor based lamps but power quality considerations prefer EEFL. CFL and EEFL manufacturers claim operating temperatures in range of -20 C < T{sub CFL} < 60 C and -30 C < T{sub CFL} < 50 C but CFL frequently damage in wet and damp locations. Costs of low THD and high PF CFL, EEFL and LED lamps may be five to ten times higher that high THD and low PF lamps. Choice of a lamp depends upon its current THD, PF, life span, energy consumption, efficiency, efficacy, color rendering index (CRI) and associated physical effects. This work proposes manufacturing and user level innovations to get rid of low PF problems. Keeping in view downside of phosphor based lamps our research concludes widespread adoption of LED lamps. Government and commercial buildings may consider full spectrum hybrid thermal photovoltaic and solar fiber optic illumination systems. (author)

  5. A twin-mirrored galvanometer laser light sheet generator

    Science.gov (United States)

    Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

    1988-01-01

    A galvanometer mirror-based laser light sheet system has been developed for use in the Basic Aerodynamics Research Tunnel at NASA Langley. This system generates and positions single or multiple light sheets over aeronautical research models being tested in the low speed tunnel. This report describes a twin mirrored galvanometer laser light sheet generator and shows typical light sheet arrangements in use. With this system, illumination of smoke entrained in the flow over a delta wing model reveals the vortical flow produced by the separation of the flow at the leading edge of the model. The light sheet system has proven to be very adaptable and easy to use in sizing and positioning light sheets in wind tunnel applications.

  6. Different light sources in photodynamic therapy for use in photorejuvenation

    CSIR Research Space (South Africa)

    Van Kets, V

    2010-09-01

    Full Text Available Photodynamic therapy (PDT) has recently emerged as a treatment modality for photorejuvenation of the skin. This study is a preliminary investigation into the effect of different light sources to activate hypericin, a plant-derived photosensitizer...

  7. Future Synchrotron Light Sources Based on Ultimate Storage Rings

    Energy Technology Data Exchange (ETDEWEB)

    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

  8. Recent Beam Measurements and New Instrumentation at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Sannibale, F.; Baptiste, K.; Barry, W.; Chin, M.; /LBL, Berkeley; Filippetto, D.; /Frascati; Jaegerhofer, L.; /Vienna, Tech. U.; Julian, J.; Kwiatkowski, S.; Low, R.; Plate, D.; Portmann, G.; Robin, D.; Scarvie, T.; /LBL, Berkeley; Stupakov, G.; /SLAC; Weber, J.; Zolotorev, M.; /LBL, Berkeley

    2012-04-11

    The Advanced Light Source (ALS) in Berkeley was the first of the soft x-ray third generation light source ever built, and since 1993 has been in continuous and successful operation serving a large community of users in the VUV and soft x-ray community. During these years the storage ring underwent through several important upgrades that allowed maintaining the performance of this veteran facility at the forefront. The ALS beam diagnostics and instrumentation have followed a similar path of innovation and upgrade and nowadays include most of the modem and last generation devices and technologies that are commercially available and used in the recently constructed third generation light sources. In this paper we will not focus on such already widely known systems, but we will concentrate our effort in the description of some measurements techniques, instrumentation and diagnostic systems specifically developed at the ALS and used during the last few years.

  9. Science and Technology of Future Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Dierker,S.; Bergmann, U.; Corlett, J.; Dierker, S.; Falcone, R.; Galayda, J.; Gibson, M.; Hastings, J.; Hettel, B.; Hill, J.; Hussain, Z.; Kao, C.-C.; Kirx, J.; Long, G.; McCurdy, B.; Raubenheimer, T.; Sannibale, F.; Seeman, J.; Shen, Z.-X.; Shenoy, g.; Schoenlein, B.; Shen, Q.; Stephenson, B.; Stohr, J.; Zholents, A.

    2008-12-01

    Many of the important challenges facing humanity, including developing alternative sources of energy and improving health, are being addressed by advances that demand the improved understanding and control of matter. While the visualization, exploration, and manipulation of macroscopic matter have long been technological goals, scientific developments in the twentieth century have focused attention on understanding matter on the atomic scale through the underlying framework of quantum mechanics. Of special interest is matter that consists of natural or artificial nanoscale building blocks defined either by atomic structural arrangements or by electron or spin formations created by collective correlation effects. The essence of the challenge to the scientific community has been expressed in five grand challenges for directing matter and energy recently formulated by the Basic Energy Sciences Advisory Committee [1]. These challenges focus on increasing our understanding of, and ultimately control of, matter at the level of atoms, electrons. and spins, as illustrated in Figure 1.1, and serve the entire range of science from advanced materials to life sciences. Meeting these challenges will require new tools that extend our reach into regions of higher spatial, temporal, and energy resolution. X-rays with energies above 10 keV offer capabilities extending beyond the nanoworld shown in Figure 1.1 due to their ability to penetrate into optically opaque or thick objects. This opens the door to combining atomic level information from scattering studies with 3D information on longer length scales from real space imaging with a resolution approaching 1 nm. The investigation of multiple length scales is important in hierarchical structures, providing knowledge about function of living organisms, the atomistic origin of materials failure, the optimization of industrial synthesis, or the working of devices. Since the fundamental interaction that holds matter together is of

  10. Science and Technology of Future Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, Uwe; Corlett, John; Dierker, Steve; Falcone, Roger; Galayda, John; Gibson, Murray; Hastings, Jerry; Hettel, Bob; Hill, John; Hussain, Zahid; Kao, Chi-Chang; Kirz, Janos; Long, Danielle; McCurdy, Bill; Raubenheimer, Tor; Sannibale, Fernando; Seeman, John; Shen, Z. -X.; Schenoy, Gopal; Schoenlein, Bob; Shen, Qun; Stephenson, Brian; Stohr, Joachim; Zholents, Alexander

    2009-01-28

    Many of the important challenges facing humanity, including developing alternative sources of energy and improving health, are being addressed by advances that demand the improved understanding and control of matter. While the visualization, exploration, and manipulation of macroscopic matter have long been technological goals, scientific developments in the twentieth century have focused attention on understanding matter on the atomic scale through the underlying framework of quantum mechanics. Of special interest is matter that consists of natural or artificial nanoscale building blocks defined either by atomic structural arrangements or by electron or spin formations created by collective correlation effects The essence of the challenge to the scientific community has been expressed in five grand challenges for directing matter and energy recently formulated by the Basic Energy Sciences Advisory Committee. These challenges focus on increasing our understanding of, and ultimately control of, matter at the level of atoms, electrons. and spins, as illustrated in Figure 1.1, and serve the entire range of science from advanced materials to life sciences. Meeting these challenges will require new tools that extend our reach into regions of higher spatial, temporal, and energy resolution. X-rays with energies above 10 keV offer capabilities extending beyond the nanoworld shown in Figure 1.1 due to their ability to penetrate into optically opaque or thick objects. This opens the door to combining atomic level information from scattering studies with 3D information on longer length scales from real space imaging with a resolution approaching 1 nm. The investigation of multiple length scales is important in hierarchical structures, providing knowledge about function of living organisms, the atomistic origin of materials failure, the optimization of industrial synthesis, or the working of devices. Since the fundamental interaction that holds matter together is of

  11. Performance of single mechanoluminescent particle as ubiquitous light source.

    Science.gov (United States)

    Terasaki, Nao; Xu, Chao-Nan

    2014-08-01

    In this study, we have investigated mechanoluminescent (ML) performance of single ML particle as ubiquitous light source. When using high-speed CCD camera with image intensifier and microscopic equipment, mechanoluminescence from single particle was observed. As to the quantitative ML evaluation of the single ML particle was carried out using photomultiplier, and successfully estimated the performance of the single ML particle as an intensity controllable light source in nW order.

  12. A new LED light source for display cases

    DEFF Research Database (Denmark)

    Dam-Hansen, Carsten; Petersen, Paul Michael

    Abstract: We report a new LED light source suitable for illumination of gold objects. It has a variable correlated color temperature from 2760 K to 2200 K with a high color rendering index up to 97.......Abstract: We report a new LED light source suitable for illumination of gold objects. It has a variable correlated color temperature from 2760 K to 2200 K with a high color rendering index up to 97....

  13. Modification of light sources for appropriate biological action

    Energy Technology Data Exchange (ETDEWEB)

    Kozakov, R; Schoepp, H; Franke, St [Leibniz Institute of Plasma Science and Technology, Felix-Hausdorff-Str. 2, D-17489 Greifswald (Germany); Stoll, C; Kunz, D, E-mail: kozakov@inp-greifswald.d [Charite-Universitymedicine Berlin, Sleep Research and Clinical Chronobiology, Gr. Hamburger Str. 5-11, D-10115 Berlin (Germany)

    2010-06-16

    The impact of the non-visual action of light on the design of novel light sources is discussed. Therefore possible modifications of lamps dealing with spectral tailoring and their action on melatonin suppression in usual life situations are investigated. The results of melatonin suppression by plasma lamps are presented. It is shown that even short-time exposure to usual light levels in working areas has an influence on the melatonin onset.

  14. Visible and ultraviolet light sources based nonlinear interaction of lasers

    DEFF Research Database (Denmark)

    Andersen, Martin Thalbitzer; Tidemand-Lichtenberg, Peter; Jain, Mayank;

    Different light sources can be used for optically stimulated luminescence measurements and usually a halogen lamp in combination with filters or light emitting diodes (LED’s) are used to provide the desired stimulation wavelength. However lasers can provide a much more well-defined beam, very...

  15. Hyperspectral microscopy to identify foodborne bacteria with optimum lighting source

    Science.gov (United States)

    Hyperspectral microscopy is an emerging technology for rapid detection of foodborne pathogenic bacteria. Since scattering spectral signatures from hyperspectral microscopic images (HMI) vary with lighting sources, it is important to select optimal lights. The objective of this study is to compare t...

  16. Coherent broadband light source for parallel optical coherence tomography

    NARCIS (Netherlands)

    Rivier, S.; Laversenne, L.; Bourquin, S.; Salathé, R.P.; Pollnau, M.; Grivas, C.; Shepherd, D.P.; Eason, R.W.; Flury, M.; Philipoussis, I.; Herzig, H.P.

    2004-01-01

    A Ti:sapphire planar waveguide is rib structured by Ar ion milling to provide parallel channel waveguides. By coupling high-power pump light through a microlens array into the waveguides, a novel broadband luminescent parallel emitter is demonstrated as a light source for parallel optical coherence

  17. Compact synchrotron light source of the HSRC.

    Science.gov (United States)

    Yoshida, K; Takayama, T; Hori, T

    1998-05-01

    A 700 MeV synchrotron radiation source optimized in order to be incorporated in the university laboratory is under commissioning at Hiroshima University. The storage ring is of a racetrack type with two long straight sections for installing undulators. The bending field is as strong as 2.7 T, produced by normal-conducting magnet technology, and delivers synchrotron radiation with a critical wavelength of 1.42 nm. The strong magnetic field also enables a low-energy injection scheme to be employed owing to the fast radiation damping. A 150 MeV microtron has been adopted as the injector.

  18. Polarized light source based on graphene-nanoribbon hybrid structure

    Science.gov (United States)

    Xu, Pengfei; Zhang, Han; Qian, Haoliang; Chen, Bigeng; Jiang, Xiaoshun; Wu, Yuanpeng; Liu, Xiaowei; Liu, Xu; Yang, Qing

    2017-07-01

    Nanoscale light source is the key element for on-chip integrated optical communication system. As an important property of light source, polarization can be exploited to improve the information capacity of optical communication and the sensitivity of optical sensing. We demonstrate a novel TE-polarized light source based on graphene-nanoribbon (G-NR) hybrid structure. Thanks to the polarizing dependent absorption along graphene layer, the random polarized emission of nanoribbon (NR) can be transferred into the same TE polarization. In addition, lasing action in G-NR hybrid structure is also investigated. We attribute the polarization control to the differential attenuation of electromagnetic modes in graphene. Our simulation revealed electromagnetic field distribution and far field polar images of TE and TM modes in nanoribbon, which is consistent with experimental results. The compact G-NR hybrid structure light source offers a new way to realize the polarization controllable nanoscale light source and facilitate the practical applications of nanowire or nanoribbon light source.

  19. The macromolecular crystallography facility at the advanced light source

    Science.gov (United States)

    Earnest, Thomas; Padmore, Howard; Cork, Carl; Behrsing, Rolf; Kim, Sung-Hou

    1996-10-01

    Synchrotron radiation offers several advantages over the use of rotating anode sources for biological crystallography, which allow for the collection of higher-resolution data, substantially more rapid data collection, phasing by multiwavelength anomalous diffraction (MAD) techniques, and time-resolved experiments using polychromatic radiation (Laue diffraction). The use of synchrotron radiation is often necessary to record useful data from crystals which diffract weakly or have very large unit cells. The high brightness and stability characteristics of the advanced light source (ALS) at Lawrence Berkeley National Laboratory, along with the low emittance and long straight sections to accommodate insertion devices present in third generation synchrotrons like the ALS, lead to several advantages in the field of macromolecular crystallography. We are presently constructing a macromolecular crystallography facility at the ALS which is optimized for user-friendliness and high-throughput data collection, with advanced capabilities for MAD and Laue experiments. The X-rays will be directed to three branchlines. A well-equipped support lab will be available for biochemistry, crystal mounting and sample storage, as well as computer hardware and software available, along with staff support, allowing for the complete processing of data on site.

  20. National Synchrotron Light Source annual report 1991

    Energy Technology Data Exchange (ETDEWEB)

    Hulbert, S.L.; Lazarz, N.M. (eds.)

    1992-04-01

    This report discusses the following research conducted at NSLS: atomic and molecular science; energy dispersive diffraction; lithography, microscopy and tomography; nuclear physics; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; workshop on surface structure; workshop on electronic and chemical phenomena at surfaces; workshop on imaging; UV FEL machine reviews; VUV machine operations; VUV beamline operations; VUV storage ring parameters; x-ray machine operations; x-ray beamline operations; x-ray storage ring parameters; superconducting x-ray lithography source; SXLS storage ring parameters; the accelerator test facility; proposed UV-FEL user facility at the NSLS; global orbit feedback systems; and NSLS computer system.

  1. Harmonic Generation with Single-Cycle Light Pulses

    Directory of Open Access Journals (Sweden)

    Sukhorukov A.A.

    2013-03-01

    Full Text Available We study theoretically spatiotemporal pulse dynamics in cubic nonlinear media with instant response, nonresonant absorption and normal group velocity dispersion and reveal new features of harmonic generation when the pulse duration is reduced, including the suppression of third-harmonic generation for single-cycle light pulses.

  2. Optical pulse generator using liquid crystal light valve

    Science.gov (United States)

    Collins, S. A., Jr.

    1984-01-01

    Numerical optical computing is discussed. A design for an optical pulse generator using a Hughes Liquid crystal light valve and intended for application as an optical clock in a numerical optical computer is considered. The pulse generator is similar in concept to the familiar electronic multivibrator, having a flip-flop and delay units.

  3. Alternative biomass sources for thermal energy generation

    Science.gov (United States)

    Steensen, Torge; Müller, Sönke; Dresen, Boris; Büscher, Olaf

    2015-04-01

    Traditionally, renewable biomass energy sources comprise forests, agriculture and other large vegetation units. With the increasing demand on those landscape elements, including conflicts of interest to nature conservation and food production, the research focus should also incorporate smaller vegetation entities. In this study, we highlight the availability of small-scale features like roadside vegetation or hedges, which are rarely featured in maps. Roadside vegetation, however, is well known and regularly trimmed to allow the passing of traffic but the cut material is rarely harvested. Here, we combine a remote-sensing-based approach to quantify the seasonal biomass harvests with a GIS-based method to outline optimal transportation routes to, and the location of, storage units and power plants. Our main data source will be ESA's upcoming Sentinel-2 optical satellite. Spatial resolution of 10 meters in the visible and near infrared requires the use of spectral unmixing to derive end member spectra of the targeted biomass objects. Additional stereo-matching and LIDAR measurements allow the accompanying height estimate to derive the biomass volume and its changes over time. GIS data bases from the target areas allow the discrimination between traditional, large features (e.g. forests and agriculture) as well as previously unaccounted for, smaller vegetation units. With the mapped biomass occurrence and additional, GIS-based infrastructure information, we can outline transport routes that take into account local restrictions like nature reserve areas, height or weight limitations as well as transport costs in relation to potential gains. This information can then be processed to outline optimal places for power plants. To simulate the upcoming Sentinel-2 data sets, we use airborne data from the AISA Eagle, spatially and spectrally down-sampled to match Sentinel 2's resolution. Our test scenario is an area in western Germany, the Kirchheller Heide, close to the city

  4. Visible light scatter as quantitative information source on milk constituents

    DEFF Research Database (Denmark)

    Melentieva, Anastasiya; Kucheryavskiy, Sergey; Bogomolov, Andrey

    2012-01-01

    -time monitoring of processes and products. Optical analysis is generally performed in near and middle infrared (NIR and MIR) regions and relies on the component absorbance and Beer’s Law. The light scatter effect is therefore considered as a disturbance to be avoided during the measurement or eliminated...... at the data analysis stage. The region of visible (Vis) light (400-800 nm) is economically attractive, because it offers a range of inexpensive light sources, optics and detectors. At present, however, it is commonly considered useless, because of the light scatter by fat globules (1-10 μm) and protein...

  5. The Materials Science beamline upgrade at the Swiss Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Willmott, P. R., E-mail: philip.willmott@psi.ch; Meister, D.; Leake, S. J.; Lange, M.; Bergamaschi, A. [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); and others

    2013-07-16

    The wiggler X-ray source of the Materials Science beamline at the Swiss Light Source has been replaced with a 14 mm-period cryogenically cooled in-vacuum undulator. In order to best exploit the increased brilliance of this new source, the entire front-end and optics have been redesigned. The Materials Science beamline at the Swiss Light Source has been operational since 2001. In late 2010, the original wiggler source was replaced with a novel insertion device, which allows unprecedented access to high photon energies from an undulator installed in a medium-energy storage ring. In order to best exploit the increased brilliance of this new source, the entire front-end and optics had to be redesigned. In this work, the upgrade of the beamline is described in detail. The tone is didactic, from which it is hoped the reader can adapt the concepts and ideas to his or her needs.

  6. A Versatile and Simple Approach to Generate Light Emission in Semiconductors Mediated by Electric Double Layers

    KAUST Repository

    Pu, Jiang

    2017-04-18

    The light-emitting device is the primary device for current light sources. In principle, conventional light-emitting devices need heterostructures and/or intentional carrier doping to form a p-n junction. This junction formation is, however, very difficult to achieve for most emerging semiconductors, and the fabrication of light-emitting devices is invariably a significant challenge. This study proposes a versatile and simple approach to realize light-emitting devices. This proposed device requires only a semiconducting film with two electrodes that are covered with an electrolyte. This unique structure achieves light emission at a voltage slightly larger than the bandgap energy of materials. This study applies this concept to emerging direct bandgap semiconductors, such as transition metal dichalcogenide monolayers and zinc oxide single crystals. These devices generate obvious light emission and provide sufficient evidence of the formation of a dynamic p-i-n junction or tunneling junction, presenting a versatile technique to develop optoelectronic devices.

  7. Report of the Basic Energy Sciences Workshop on Compact Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Barletta, William A. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Borland, Michael [Argonne National Lab. (ANL), Argonne, IL (United States)

    2010-05-11

    This report is based on a BES Workshop on Compact Light Sources, held May 11-12, 2010, to evaluated the advantages and disadvantages of compact light source approaches and compared their performance to the third generation storage rings and free-electron lasers. The workshop examined the state of the technology for compact light sources and their expected progress. The workshop evaluated the cost efficiency, user access, availability, and reliability of such sources. Working groups evaluated the advantages and disadvantages of Compact Light Source (CLS) approaches, and compared their performance to the third-generation storage rings and free-electron lasers (FELs). The primary aspects of comparison were 1) cost effectiveness, 2) technical availability v. time frame, and 3) machine reliability and availability for user access. Five categories of potential sources were analyzed: 1) inverse Compton scattering (ICS) sources, 2) mini storage rings, 3) plasma sources, 4) sources using plasma-based accelerators, and 5) laser high harmonic generation (HHG) sources. Compact light sources are not a substitute for large synchrotron and FEL light sources that typically also incorporate extensive user support facilities. Rather they offer attractive, complementary capabilities at a small fraction of the cost and size of large national user facilities. In the far term they may offer the potential for a new paradigm of future national user facility. In the course of the workshop, we identified overarching R&D topics over the next five years that would enhance the performance potential of both compact and large-scale sources: Development of infrared (IR) laser systems delivering kW-class average power with femtosecond pulses at kHz repetition rates. These have application to ICS sources, plasma sources, and HHG sources. Development of laser storage cavities for storage of 10-mJ picosecond and femtosecond pulses focused to micron beam sizes. Development of high-brightness, high

  8. Light Source Matters--Students' Explanations about the Behavior of Light When Different Light Sources Are Used in Task Assignments of Optics

    Science.gov (United States)

    Kesonen, Mikko Henri Petteri; Asikainen, Mervi Anita; Hirvonen, Pekka Emil

    2017-01-01

    In the present article, the context-dependency of student reasoning is studied in a context of optics. We investigated introductory students' explanations about the behavior of light when different light sources, namely a small light bulb and a laser, were used in otherwise identical task assignments. The data was gathered with the aid of pretest…

  9. The Munich Compact Light Source: initial performance measures.

    Science.gov (United States)

    Eggl, Elena; Dierolf, Martin; Achterhold, Klaus; Jud, Christoph; Günther, Benedikt; Braig, Eva; Gleich, Bernhard; Pfeiffer, Franz

    2016-09-01

    While large-scale synchrotron sources provide a highly brilliant monochromatic X-ray beam, these X-ray sources are expensive in terms of installation and maintenance, and require large amounts of space due to the size of storage rings for GeV electrons. On the other hand, laboratory X-ray tube sources can easily be implemented in laboratories or hospitals with comparatively little cost, but their performance features a lower brilliance and a polychromatic spectrum creates problems with beam hardening artifacts for imaging experiments. Over the last decade, compact synchrotron sources based on inverse Compton scattering have evolved as one of the most promising types of laboratory-scale X-ray sources: they provide a performance and brilliance that lie in between those of large-scale synchrotron sources and X-ray tube sources, with significantly reduced financial and spatial requirements. These sources produce X-rays through the collision of relativistic electrons with infrared laser photons. In this study, an analysis of the performance, such as X-ray flux, source size and spectra, of the first commercially sold compact light source, the Munich Compact Light Source, is presented.

  10. Random Numbers Generated from Audio and Video Sources

    Directory of Open Access Journals (Sweden)

    I-Te Chen

    2013-01-01

    Full Text Available Random numbers are very useful in simulation, chaos theory, game theory, information theory, pattern recognition, probability theory, quantum mechanics, statistics, and statistical mechanics. The random numbers are especially helpful in cryptography. In this work, the proposed random number generators come from white noise of audio and video (A/V sources which are extracted from high-resolution IPCAM, WEBCAM, and MPEG-1 video files. The proposed generator applied on video sources from IPCAM and WEBCAM with microphone would be the true random number generator and the pseudorandom number generator when applied on video sources from MPEG-1 video file. In addition, when applying NIST SP 800-22 Rev.1a 15 statistics tests on the random numbers generated from the proposed generator, around 98% random numbers can pass 15 statistical tests. Furthermore, the audio and video sources can be found easily; hence, the proposed generator is a qualified, convenient, and efficient random number generator.

  11. 46 CFR 111.10-4 - Power requirements, generating sources.

    Science.gov (United States)

    2010-10-01

    ... services include cooking, heating, air conditioning (where installed), domestic refrigeration, mechanical... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

  12. The POLIS interferometer for ponderomotive squeezed light generation

    Science.gov (United States)

    Calloni, Enrico; Conte, Andrea; De Laurentis, Martina; Naticchioni, Luca; Puppo, Paola; Ricci, Fulvio

    2016-07-01

    POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.

  13. The POLIS interferometer for ponderomotive squeezed light generation

    Energy Technology Data Exchange (ETDEWEB)

    Calloni, Enrico [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Conte, Andrea [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); De Laurentis, Martina, E-mail: martina.delaurentis@na.infn.it [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Naticchioni, Luca [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); Puppo, Paola [INFN, Sezione di Roma1 (Italy); Ricci, Fulvio [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy)

    2016-07-11

    POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.

  14. Suboptimal light conditions influence source-sink metabolism during flowering

    Directory of Open Access Journals (Sweden)

    Annelies eChristiaens

    2016-03-01

    Full Text Available Reliance on carbohydrates during flower forcing was investigated in one early and one late flowering cultivar of azalea (Rhododendron simsii hybrids. Carbohydrate accumulation, invertase activity, and expression of a purported sucrose synthase gene (RsSUS was monitored during flower forcing under suboptimal (natural and optimal (supplemental light light conditions, after a cold treatment (7°C + dark to break flower bud dormancy. Post-production sucrose metabolism and flowering quality was also assessed. Glucose and fructose concentrations and invertase activity increased in petals during flowering, while sucrose decreased. In suboptimal light conditions RsSUS expression in leaves increased as compared to optimal light conditions, indicating that plants in suboptimal light conditions have a strong demand for carbohydrates. However, carbohydrates in leaves were markedly lower in suboptimal light conditions compared to optimal light conditions. This resulted in poor flowering of plants in suboptimal light conditions. Post-production flowering relied on the stored leaf carbon, which could be accumulated under optimal light conditions in the greenhouse. These results show that flower opening in azalea relies on carbohydrates imported from leaves and is source-limiting under suboptimal light conditions.

  15. The difference among generations in evaluating interior lighting environment.

    Science.gov (United States)

    Oi, Naoyuki

    2005-01-01

    This paper explores the difference among generations in evaluating interior lighting environment, and provides some knowledge for interior lighting design, which can accommodate all generations. Fifteen Computer Graphic pictures, which had the same dimensions (W3000 mmxH2800 mmxD6300 mm) but a different luminous environment are evaluated. Pictures are presented on a screen with a liquid crystal projector in a shaded dark room.A Semantic Differential technique with 12 subjective scales with 5 steps was used for the evaluation. Participants were chosen from 3 age groups: young, middle age, and elderly people.A difference among generations in evaluating interior lighting environment emerged. These tendencies could not be explained solely by visibility. It seems that the personal experience is closely related to the evaluation and preference of luminous environment.

  16. Light-emitting diode-generated red light inhibits keloid fibroblast proliferation.

    Science.gov (United States)

    Mamalis, Andrew; Jagdeo, Jared

    2015-01-01

    Red light is part of the visible light spectrum that does not generate DNA adducts associated with skin cancer and photoaging and may represent a safer therapeutic modality for treatment of keloid scars and other fibrotic skin diseases. Our laboratory previously demonstrated that light-emitting diode-generated red light (LED-RL) inhibits proliferation of skin fibroblasts. The effects of LED-RL on keloidal skin are not well characterized. To determine the effect of LED-RL on keloid-derived fibroblast proliferation and viability in vitro. Irradiation of primary keloid-derived human skin fibroblasts using LED-RL panels was performed in vitro, and modulation of proliferation and viability was quantified using trypan blue dye exclusion assay. Statistical analysis was performed using analysis of variance to compare treatment arms and the Student t-test to compare each treatment arm with the paired bench control arm. Keloid fibroblasts treated with LED-RL 240, 320, and 480 J/cm demonstrated statistically significant dose-dependent decreases in relative proliferation rate of 12.4%, 16.5%, and 28.9%, respectively, compared with matched nonirradiated controls (p Light-emitting diode-generated red light can inhibit keloid fibroblast proliferation in a dose-dependent manner without altering viability. Light-emitting diode-generated red light has the potential to contribute to the treatment of keloids and other fibrotic skin diseases and is worthy of further translational and clinical investigation.

  17. Increased collection efficiency of LIFI high intensity electrodeless light source

    Science.gov (United States)

    Hafidi, Abdeslam; DeVincentis, Marc; Duelli, Markus; Gilliard, Richard

    2008-02-01

    Recently, RF driven electrodeless high intensity light sources have been implemented successfully in the projection display systems for HDTV and videowall applications. This paper presents advances made in the RF waveguide and electric field concentrator structures with the purpose of reducing effective arc size and increasing light collection. In addition, new optical designs are described that further improve system efficiency. The results of this work demonstrate that projection system light throughput is increased relative to previous implementations and performance is optimized for home theater and other front projector applications that maintain multi-year lifetime without re-lamping, complete spectral range, fast start times and high levels of dynamic contrast due to dimming flexibility in the light source system.

  18. Tunable light source for use in photoacoustic spectrometers

    Science.gov (United States)

    Bisson, Scott E.; Kulp, Thomas J.; Armstrong, Karla M.

    2005-12-13

    The present invention provides a photoacoustic spectrometer that is field portable and capable of speciating complex organic molecules in the gas phase. The spectrometer has a tunable light source that has the ability to resolve the fine structure of these molecules over a large wavelength range. The inventive light source includes an optical parametric oscillator (OPO) having combined fine and coarse tuning. By pumping the OPO with the output from a doped-fiber optical amplifier pumped by a diode seed laser, the inventive spectrometer is able to speciate mixtures having parts per billion of organic compounds, with a light source that has a high efficiency and small size, allowing for portability. In an alternative embodiment, the spectrometer is scanned by controlling the laser wavelength, thus resulting in an even more compact and efficient design.

  19. Solid state light source driver establishing buck or boost operation

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, Fred

    2017-08-29

    A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boost converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.

  20. Light-Patterned Current Generation in a Droplet Bilayer Array

    Science.gov (United States)

    Restrepo Schild, Vanessa; Booth, Michael J.; Box, Stuart J.; Olof, Sam N.; Mahendran, Kozhinjampara R.; Bayley, Hagan

    2017-04-01

    We have created a 4 × 4 droplet bilayer array comprising light-activatable aqueous droplet bio-pixels. Aqueous droplets containing bacteriorhodopsin (bR), a light-driven proton pump, were arranged on a common hydrogel surface in lipid-containing oil. A separate lipid bilayer formed at the interface between each droplet and the hydrogel; each bilayer then incorporated bR. Electrodes in each droplet simultaneously measured the light-driven proton-pumping activities of each bio-pixel. The 4 × 4 array derived by this bottom-up synthetic biology approach can detect grey-scale images and patterns of light moving across the device, which are transduced as electrical current generated in each bio-pixel. We propose that synthetic biological light-activatable arrays, produced with soft materials, might be interfaced with living tissues to stimulate neuronal pathways.

  1. White-light generation with sub-ps pulses.

    Science.gov (United States)

    Calendron, Anne-Laure; Çankaya, Hüseyin; Cirmi, Giovanni; Kärtner, Franz X

    2015-06-01

    We generate white light supercontinuum from slightly sub-picosecond pulses at 1.03 µm and 515 nm. We compare the spectra and stability for various crystals, focusing conditions and pulse durations, and determine the best parameters for sub-picosecond driver pulse duration. Comparing the experimental observations with the theory of white-light generation from Brodeur and Chin, it appears that in this particular range of pump pulse duration, two mechanisms interact and prevent a catastrophic collapse of the beam: multi-photon excitation (typical for ~100-fs-long pulses) and avalanche ionization (typical for >1-ps pulses). The two processes both manifest themselves in different experimental observations.

  2. Performance of a beam-multiplexing diamond crystal monochromator at the Linac Coherent Light Source

    DEFF Research Database (Denmark)

    Zhu, Diling; Feng, Yiping; Stoupin, Stanislav

    2014-01-01

    A double-crystal diamond monochromator was recently implemented at the Linac Coherent Light Source. It enables splitting pulses generated by the free electron laser in the hard x-ray regime and thus allows the simultaneous operations of two instruments. Both monochromator crystals are High-Pressu...

  3. 1994 Activity Report, National Synchrotron Light Source. Annual report, October 1, 1993-September 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Rothman, E.Z. [ed.

    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.

  4. Efficient all solid-state continuous-wave yellow-orange light source

    DEFF Research Database (Denmark)

    Janousek, Jiri; Johansson, Sandra; Tidemand-Lichtenberg, Peter;

    2005-01-01

    We present highly efficient sum-frequency generation between two CW IR lasers using periodically poled KTP. The system is based on the 1064 and 1342 nm laser-lines of two Nd:YVO4 lasers. This is an all solid-state light source in the yellow-orange spectral range. The system is optimized in terms...

  5. Does the light source affect the repairability of composite resins?

    Directory of Open Access Journals (Sweden)

    Emel KARAMAN

    2014-08-01

    Full Text Available The aim of this study was to examine the effect of the light source on the microshear bond strength of different composite resins repaired with the same substrate. Thirty cylindrical specimens of each composite resin—Filtek Silorane, Filtek Z550 (3M ESPE, Gradia Direct Anterior (GC, and Aelite Posterior (BISCO—were prepared and light-cured with a QTH light curing unit (LCU. The specimens were aged by thermal cycling and divided into three subgroups according to the light source used—QTH, LED, or PAC (n = 10. They were repaired with the same substrate and a Clearfil Repair Kit (Kuraray. The specimens were light-cured and aged for 1 week in distilled water at 37 °C. The microshear bond strength and failure modes were assessed. There was no significant difference in the microshear bond strength values among the composite resins, except for the Filtek Silorane group that showed significantly lower bond strength values when polymerized with the PAC unit compared to the QTH or LED unit. In conclusion, previously placed dimethacrylate-based composites can be repaired with different light sources; however, if the composite to be repaired is silorane-based, then using a QTH or LED device may be the best option.

  6. The Advanced Light Source (ALS) Radiation Safety System. Revised

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, A.L.; Oldfather, D.E.; Lindner, A.F.

    1993-08-01

    The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) is a 1.5 Gev synchrotron light source facility consisting of a 120 kev electron gun, 50 Mev linear accelerator, 1.5 Gev booster synchrotron, 200 meter circumference electron storage ring, and many photon beamline transport systems for research. Figure 1. ALS floor plan. Pairs of neutron and gamma radiation monitors are shown as dots numbered from 1 to 12. The Radiation Safety System for the ALS has been designed and built with a primary goal of providing protection against inadvertent personnel exposure to gamma and neutron radiation and, secondarily, to enhance the electrical safety of select magnet power supplies.

  7. Survey and alignment for the Swiss Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Wei, F.Q.; Dreyer, K.; Fehlmann, U.; Pochon, J.L.; Wrulich, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-07-01

    The Swiss Light Source (SLS) is a dedicated high brightness synchrotron light source currently under construction at the Paul Scherrer Institute (PSI) in Villigen. It will be commissioned in 2001. The accelerator complex includes a 2.4 GeV electron storage ring (SR) with 288 in circumference, a full energy injection booster synchrotron (Booster) and a 100 MeV linear pre-accelerator. The general alignment method and first results of the network measurements are presented. A laser tracker LTD500 is mainly adopted for network measurements and the alignment of storage ring components. (authors)

  8. Synchrotron radiation as a light source in confocal microscopy

    Energy Technology Data Exchange (ETDEWEB)

    van der Oord, C.J.R.; Gerritsen, H.C.; Levine, Y.K. (University of Utrecht, P.O. Box 80.000, 3508 TA Utrecht (Netherlands)); Myring, W.J.; Jones, G.R.; Munro, I.H. (Daresbury Laboratory (United Kingdom))

    1992-01-01

    The optical properties of a confocal scanning microscope that was designed to utilize a synchrotron as light source are presented. The usable spectral range is from 200 nm up to 700 nm. Using 325-nm laser light, it is shown that the lateral resolution is about 125 nm, and the axial resolution better than 250 nm. After transport of the microscope from Utrecht to the Daresbury Synchrotron Source, 200-nm excitation can be applied, and the lateral resolution will drop to below 100 nm.

  9. Properties and Applications of Laser Generated X-Ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R F; Key, M H

    2002-02-25

    The rapid development of laser technology and related progress in research using lasers is shifting the boundaries where laser based sources are preferred over other light sources particularly in the XUV and x-ray spectral region. Laser based sources have exceptional capability for short pulse and high brightness and with improvements in high repetition rate pulsed operation, such sources are also becoming more interesting for their average power capability. This study presents an evaluation of the current capabilities and near term future potential of laser based light sources and summarizes, for the purpose of comparison, the characteristics and near term prospects of sources based on synchrotron radiation and free electron lasers. Conclusions are drawn on areas where the development of laser based sources is most promising and competitive in terms of applications potential.

  10. Applications of laser wakefield accelerator-based light sources

    Science.gov (United States)

    Albert, Félicie; Thomas, Alec G. R.

    2016-11-01

    Laser-wakefield accelerators (LWFAs) were proposed more than three decades ago, and while they promise to deliver compact, high energy particle accelerators, they will also provide the scientific community with novel light sources. In a LWFA, where an intense laser pulse focused onto a plasma forms an electromagnetic wave in its wake, electrons can be trapped and are now routinely accelerated to GeV energies. From terahertz radiation to gamma-rays, this article reviews light sources from relativistic electrons produced by LWFAs, and discusses their potential applications. Betatron motion, Compton scattering and undulators respectively produce x-rays or gamma-rays by oscillating relativistic electrons in the wakefield behind the laser pulse, a counter-propagating laser field, or a magnetic undulator. Other LWFA-based light sources include bremsstrahlung and terahertz radiation. We first evaluate the performance of each of these light sources, and compare them with more conventional approaches, including radio frequency accelerators or other laser-driven sources. We have then identified applications, which we discuss in details, in a broad range of fields: medical and biological applications, military, defense and industrial applications, and condensed matter and high energy density science.

  11. Selecting Electricity Generation Sources in Remote Locations

    Science.gov (United States)

    2007-03-01

    turbines, control systems, and energy storage systems to enable wind generation to be used in remote applications (Rogers, Manwell , McGowan, & Ellis, 2001...effective as long as support is readily available (Rogers, Manwell , McGowan, & Ellis, 2001). The results in improved efficiency and reduced costs...Talking. Wired Magazine, 7(1). 143 Rogers, A.L., Manwell , J.F., McGowan, J.G., & Ellis, A.F. (2001). Design Requirements for Medium-Sized Wind

  12. High efficiency light source using solid-state emitter and down-conversion material

    Science.gov (United States)

    Narendran, Nadarajah; Gu, Yimin; Freyssinier, Jean Paul

    2010-10-26

    A light emitting apparatus includes a source of light for emitting light; a down conversion material receiving the emitted light, and converting the emitted light into transmitted light and backward transmitted light; and an optic device configured to receive the backward transmitted light and transfer the backward transmitted light outside of the optic device. The source of light is a semiconductor light emitting diode, a laser diode (LD), or a resonant cavity light emitting diode (RCLED). The down conversion material includes one of phosphor or other material for absorbing light in one spectral region and emitting light in another spectral region. The optic device, or lens, includes light transmissive material.

  13. Seeing "the Dress" in the Right Light: Perceived Colors and Inferred Light Sources.

    Science.gov (United States)

    Chetverikov, Andrey; Ivanchei, Ivan

    2016-08-01

    In the well-known "dress" photograph, people either see the dress as blue with black stripes or as white with golden stripes. We suggest that the perception of colors is guided by the scene interpretation and the inferred positions of light sources. We tested this hypothesis in two online studies using color matching to estimate the colors observers see, while controlling for individual differences in gray point bias and color discrimination. Study 1 demonstrates that the interpretation of the dress corresponds to differences in perceived colors. Moreover, people who perceive the dress as blue-and-black are two times more likely to consider the light source as frontal, than those who see the white-and-gold dress. The inferred light sources, in turn, depend on the circadian changes in ambient light. The interpretation of the scene background as a wall or a mirror is consistent with the perceived colors as well. Study 2 shows that matching provides reliable results on differing devices and replicates the findings on scene interpretation and light sources. Additionally, we show that participants' environmental lighting conditions are an important cue for perceiving the dress colors. The exact mechanisms of how environmental lighting and circadian changes influence the perceived colors of the dress deserve further investigation.

  14. Ultraviolet Light Generation in Gas-Filled Kagome Photonic Crystal Fiber

    Science.gov (United States)

    Rodrigues, Sílvia M. G.; Facão, Margarida; Ferreira, Mário F. S.

    2015-03-01

    Kagome hollow-core photonic crystal fibers were found to be ideal for the occurrence of ultrafast non-linear optics. This article reports the optimal conditions for the generation of ultraviolet light using a gas filled kagome hollow-core-photonic crystal fiber. It is shown that by changing the pressure of the gas and the input pulse characteristics, the efficiency of conversion and quality of ultraviolet light can be improved, as well as tuning its central frequency. Results suggest that a highly coherent and tunable ultraviolet light source can be constructed, which can find numerous applications.

  15. Particle beam generator using a radioactive source

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, D.G.

    1991-12-31

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  16. Generation of pulsed light in the visible spectral region based on non-linear cavity dumping

    DEFF Research Database (Denmark)

    Johansson, Sandra; Andersen, Martin; Tidemand-Lichtenberg, Peter

    We propose a novel generic approach for generation of pulsed light in the visible spectrum based on sum-frequency generation between the high circulating intra-cavity power of a high finesse CW laser and a single-passed pulsed laser. For demonstration, we used a CW 1342 nm laser mixed...... with a passively Q-switched 1064 nm laser to generate pulsed light at 593 nm. Light sources in the yellow spectral region have several applications, e.g. dermatology, laser displays and flow cytometry. Traditionally, copper-vapor lasers at 578 nm and dye lasers are used in this spectral region. These are however...... as the CW light source, using a folded cavity to achieve tight focussing in the non-linear crystal which was a 11 mm long PPKTP. The pulsed light source was a Nd:YVO4 laser emitting at 1064 nm using Cr:YAG as a passive saturable absorber, resulting in a pulse length of 100 ns and a repetition frequency...

  17. Correlated Color Temperature Tunable Multi-chip Light Emitting Diodes Light Source Design

    Institute of Scientific and Technical Information of China (English)

    SHEN Hai-ping; PAN Jian-gen; FENG Hua-jun

    2008-01-01

    One of the methods to derive white light from light emitting diodes(LEDs) is the multi-chip white LED technology, which mixes the light from red, green and blue LEDs. Introduced is an optimal algorithm for the spectrum design of the multi-chip white LEDs in this paper. It optimizes the selection of single color LEDs and drive current controlling, so that the multi-chip white LED achieves the target correlated color temperature(CCT), as well as high luminous efficacy and good color rendering. A CCT tunable LED light source with four high-power LEDs is realized based on the above optimal design. Test results show that it maintains satisfactory color rendering and stable luminous efficacy across the whole CCT tuning range. Finally, discussed are the design improvement and the prospect of the future applications of the CCT tunable LED light source.

  18. Statistical evaluation of alternative light sources for bloodstain photography.

    Science.gov (United States)

    Lee, Wee Chuen; Khoo, Bee Ee; Bin Abdullah, Ahmad Fahmi Lim; Abdul Aziz, Zalina Binti

    2013-05-01

    Bloodstain photography is important in forensic applications, especially for bloodstain pattern analysis. This study compares the enhancement effect of bloodstain photography using three different types of light source: fluorescent white light, near-ultraviolet (UV) light-emitting diode (LED) light, and 410 nm LED light. Randomized complete block designs were implemented to identify the lighting that would statistically produce the best enhancement results for bloodstains on different types of surfaces. Bloodstain samples were prepared on white cotton, brown carpet, tar road, and wood. These samples were photographed in darkroom conditions using a Canon EOS 50D digital SLR camera, with Canon EFS 60 mm f/2.8 Macro USM lens. Two-way analysis of variance and Fisher's least significant difference test were used to analyze the contrast of the images. The statistical analysis showed that 410 nm light is the best among the tested lights for enhancing bloodstains on the tested surfaces, where the contrast of bloodstain to background was the highest.

  19. Retinal endoilluminator toxicity of xenon and light-emitting diode (LED) light source: rabbit model.

    Science.gov (United States)

    Aydin, Bahri; Dinç, Erdem; Yilmaz, S Necat; Altiparmak, U Emrah; Yülek, Fatma; Ertekin, Sevda; Yilmaz, Mustafa; Yakın, Mehmet

    2014-09-01

    This study evaluates retinal toxicity due to endoillumination with the light-emitting diode (LED) light source in comparison to endoillumination with xenon light source. Twenty-five eyes of 14 New Zealand pigmented rabbits were used in the study. The LED light (Omesis Medical Systems, Turkey) group was composed of 7 right eyes, while the other 7 right eyes constituted the xenon group (420 nm filter, 357mW/cm(2)) (Bright Star; DORC, Zuidland, Netherlands). Eleven untreated left eyes composed the control group. Twenty gauge pars plana incision 1.5 mm behind the limbus was performed in the right eyes. Twenty gauge bullet type fiberoptic endoilluminator was inserted into the eye from the incision without any pars plana vitrectomy. Fiberoptic endoilluminator was placed in such a way that it was directed toward visual streak of the rabbit retina with a 5 mm distance to retinal surface. Endoillumination was then applied for 20 min with a maximum light intensity for LED and xenon light. In left control eyes, no surgical procedure and no endoillumination were performed. One week after the endoillumination procedure, both eyes of the rabbits were enucleated following electroretinography. Sections stained with hematoxylin and eosin to evaluate morphologic changes. Retina tissues were assessed by active caspase-3 staining. There was no difference in the shape of the waveforms recorded in the eyes endoilluminated with LED light and xenon light sources compared to control eyes both before and after endoillumination application (p > 0.05). Microscopic evaluation of the retinas with hematoxylin and eosin staining demonstrated that all study groups have normal histologic properties similar to control group. No apoptosis positive cells were found within all sections in all groups. When the LED light source is used with maximum power and limited duration for endoillumination in rabbit eyes it does not produce phototoxic effects that may be detectable by electrophysiology

  20. The effect of light-activation sources on tooth bleaching

    Directory of Open Access Journals (Sweden)

    Kusai Baroudi

    2014-01-01

    Full Text Available Vital bleaching is one of the most requested cosmetic dental procedures asked by patients who seek a more pleasing smile. This procedure consists of carbamide or hydrogen peroxide gel applications that can be applied in-office or by the patient (at-home/overnight bleaching system. Some in-office treatments utilise whitening light with the objective of speeding up the whitening process. The objective of this article is to review and summarise the current literature with regard to the effect of light-activation sources on in-office tooth bleaching. A literature search was conducted using Medline, accessed via the National Library of Medicine Pub Med from 2003 to 2013 searching for articles relating to effectiveness of light activation sources on in-office tooth bleaching. This study found conflicting evidence on whether light truly improve tooth whitening. Other factors such as, type of stain, initial tooth colour and subject age which can influence tooth bleaching outcome were discussed. Conclusions: The use of light activator sources with in-office bleaching treatment of vital teeth did not increase the efficacy of bleaching or accelerate the bleaching.

  1. High Energy Density Science at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Lee, R W

    2007-10-19

    descriptions (Ch. V), and a more detailed plans for experiments (Ch. VI), highlighting the uniqueness the HEDS endstation will play in providing mission-relevant HED data and in the development of the field. One of the more exciting aspects of NNSA-relevant experiments on LCLS is that, given the extraordinary investment and consequent advances in accurate atomic-scale simulations of matter (to a large extent via the Accelerated Scientific Computing program sponsored by NNSA), the facility will provide a platform that, for the first time, will permit experiments in the regimes of interest at the time and spatial scales of the simulations. In Chapter III, the report places the potential of LCLS with an HED science endstation in the context of science required by NNSA, as well as explicating the relationship of NNSA and HED science in general. Chapter IV discusses 4th-generation light sources, like LCLS, in the context of other laboratory technologies presently utilized by NNSA. The report concludes, noting that an HED endstation on LCLS can provide access to data in regimes that are relevant to NNSA needs but no mechanism exists for providing such data. The endstation will also serve to build a broad-based community in the 'X-Games' of physics. The science generated by the facility will be a collaboration of NNSA-based laboratory scientists and university-based researchers. The LCLS endstation fulfills the need for an intermediate-scale facility capable of delivering fundamental advances and mission-relevant research in high energy density science.

  2. VCSELs and silicon light sources exploiting SOI grating mirrors

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2012-01-01

    In this talk, novel vertical-cavity laser structure consisting of a dielectric Bragg reflector, a III-V active region, and a high-index-contrast grating made in the Si layer of a silicon-on-insulator (SOI) wafer will be presented. In the Si light source version of this laser structure, the SOI gr...

  3. Advanced Light Source Activity Report 1997/1998

    Energy Technology Data Exchange (ETDEWEB)

    Greiner, Annette (ed.)

    1999-03-01

    This Lawrence Berkeley National Laboratory, Advanced Light Source (ALS) activity report for 1997/98 discusses the following topics: Introduction and Overview; Science Highlights; Facility Report; Special Events; ALS Advisory Panels 1997/98; ALS Staff 1997/98 and Facts and Figures for the year.

  4. Rare-earth plasma light source for VUV applications.

    Science.gov (United States)

    O'Sullivan, G; Carroll, P K; McLlrath, T J; Ginter, M L

    1981-09-01

    A compact versatile light source for producing VUV radiation from laser produced plasmas is described. Measurements of the spectral irradiance from CO(2) laser-produced plasmas on targets of gadolinium and ytterbium in the 115-220-nm range are given, and a comparison is made with analogous results obtained using a ruby laser.

  5. Enabling instrumentation and technology for 21st century light sources

    Energy Technology Data Exchange (ETDEWEB)

    Byrd, J.M.; Shea, T.J.; Denes, P.; Siddons, P.; Attwood, D.; Kaertner, F.; Moog, L.; Li, Y.; Sakdinawat, A.; Schlueter, R.

    2010-06-01

    We present the summary from the Accelerator Instrumentation and Technology working group, one of the five working groups that participated in the BES-sponsored Workshop on Accelerator Physics of Future Light Sources held in Gaithersburg, MD September 15-17, 2009. We describe progress and potential in three areas: attosecond instrumentation, photon detectors for user experiments, and insertion devices.

  6. Compact X-ray Light Source Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Thevuthasan, Suntharampillai; Evans, James E.; Terminello, Louis J.; Koppenaal, David W.; Manke, Kristin L.; Plata, Charity

    2012-12-01

    This report, produced jointly by EMSL and FCSD, is the result of a workshop held in September 2011 that examined the utility of a compact x-ray light source (CXLS) in addressing many scientific challenges critical to advancing energy science and technology.

  7. Intracerebral source generators characterizing concentrative meditation.

    Science.gov (United States)

    Lavallee, Christina F; Hunter, Mathew D; Persinger, Michael A

    2011-05-01

    Previous researchers have studied meditation practices as a means to understand consciousness as well as altered states of consciousness. Various meditation techniques, such as Transcendental Meditation (TM) and Qigong, have been explored with source localization tools; however, the concentrative meditation technique has yet to be fully studied in this manner. The current study demonstrates findings, which outline differential activation in a self-referential default network during meditation in participants who espouse themselves as regular concentrative meditation practitioners, as well as comparisons with a control group practicing a modified version of the relaxation response. The results are compared with other putative experimental findings employing other meditation techniques, and the findings outlined in the current study are discussed with respect to changes in perceptual awareness often reported by meditators.

  8. The Pre-Injector Linac for the Diamond Light Source

    CERN Document Server

    Christou, C

    2004-01-01

    The Diamond Light Source is a new medium-energy high brightness synchrotron light facility which is under construction on the Rutherford Appleton Laboratory site in the U.K. The accelerator facility can be divided into three major components; a 3 GeV 561 m circumference storage ring, a full-energy booster synchrotron and a 100 MeV pre-injector linac. This paper describes the linac design and plans for operation. The linac is supplied by ACCEL Instruments GmbH under a turn-key contract, with Diamond Light Source Ltd. providing linac beam diagnostics, control system hardware and standard vacuum components. Commissioning of the linac will take place in early 2005 and user operation of the facility will commence in 2007.

  9. Towards monolithic integration of germanium light sources on silicon chips

    Science.gov (United States)

    Saito, Shinichi; Zaher Al-Attili, Abdelrahman; Oda, Katsuya; Ishikawa, Yasuhiko

    2016-04-01

    Germanium (Ge) is a group-IV indirect band gap semiconductor, and therefore bulk Ge cannot emit light efficiently. However, the direct band gap energy is close to the indirect one, and significant engineering efforts are being made to convert Ge into an efficient gain material monolithically integrated on a Si chip. In this article, we will review the engineering challenges of developing Ge light sources fabricated using nano-fabrication technologies compatible with complementary metal-oxide-semiconductor processes. In particular, we review recent progress in applying high-tensile strain to Ge to reduce the direct band gap. Another important technique is doping Ge with donor impurities to fill the indirect band gap valleys in the conduction band. Realization of carrier confinement structures and suitable optical cavities will be discussed. Finally, we will discuss possible applications of Ge light sources in potential photonics-electronics convergent systems.

  10. Color holographic display with white light LED source and single phase only SLM.

    Science.gov (United States)

    Kozacki, Tomasz; Chlipala, Maksymilian

    2016-02-08

    This work presents color holographic display, which is based on a single phase only spatial light modulator (SLM). In the display entire area of the SLM is illuminated by an on-axis white light beam generated by a single large LED. The holographic display fully utilizes SLM bandwidth and has capability of full-color, full frame rate imaging of outstanding quality. This is achieved through: (i) optimal use of the source coherence volume, (ii) application of the single white light LED source, (iii) a development of a novel concept of color multiplexing technique with color filter mask in Fourier plane of the SLM, (iv) and a complex coding with improved diffraction efficiency. Within experimental part of the paper we show single color, full-color holographic 2D and 3D images generated for reconstruction depth exceeding 10 cm.

  11. Nanocrystal-based hybrid white light generation with tunable colour parameters

    Science.gov (United States)

    Nizamoglu, S.; Demir, H. V.

    2007-09-01

    We present the hybridization of CdSe/ZnS core shell nanocrystals (NCs) on InGaN/GaN based blue/near-UV LEDs to generate light widely tunable across the visible spectral range and especially within the white region of the CIE (1931) chromaticity diagram. We report on the design, growth, fabrication and characterization of these hybrid NC-LEDs. In 26 NC-LED samples, we experimentally show the effect of the NC concentration and NC film thickness on tuning the colour properties of the generated light (tristimulus coordinates, colour rendering index and correlated temperature) and further compare layer by layer assembly and blending of NCs for integration in LEDs. With greatly tunable colour properties, these hybrid white light sources hold promise for future lighting and display applications.

  12. Operation of the Metrology Light Source as a primary radiation source standard

    Directory of Open Access Journals (Sweden)

    Roman Klein

    2008-11-01

    Full Text Available The Metrology Light Source (MLS, the new electron storage ring of the Physikalisch-Technische Bundesanstalt (PTB located in Berlin, is dedicated to metrology and technological developments in the UV and extreme UV spectral range as well as in the IR and THz region. The MLS can be operated at any electron beam energy between 105 and 630 MeV and at electron beam currents varying from 1 pA (one stored electron up to 200 mA. Moreover, it is optimized for the generation of coherent synchrotron radiation in the far IR/THz range. Of special interest for PTB is the operation of the MLS as a primary radiation source standard from the near IR up to the soft x-ray region. Therefore, the MLS is equipped with all the instrumentation necessary to measure the storage ring parameters and geometrical parameters needed for the calculation of the spectral photon flux according to the Schwinger theory with low uncertainty.

  13. Does the velocity of light depend on the source movement?

    CERN Document Server

    Bilbao, Luis

    2016-01-01

    Data from spacecrafts tracking exhibit many anomalies that suggest the dependence of the speed of electromagnetic radiation with the motion of its source. This dependence is different from that predicted from emission theories that long ago have been demonstrated to be wrong. By relating the velocity of light and the corresponding Doppler effect with the velocity of the source at the time of detection, instead of the time of emission, it is possible to explain quantitatively and qualitatively the spacecraft anomalies. Also, a formulation of electromagnetism compatible with this conception is possible (and also compatible with the known electromagnetic phenomena). Under this theory the influence of the velocity of the source in the speed of light is somewhat subtle in many practical situations and probably went unnoticed in other phenomena.

  14. Does the Velocity of Light Depend on the Source Movement?

    Science.gov (United States)

    Bilbao, Luis

    2016-10-01

    Data from spacecrafts tracking exhibit many anomalies that suggest the dependence of the speed of electromagnetic radiation with the motion of its source. This dependence is different from that predicted from emission theories that long ago have been demonstrated to be wrong. By relating the velocity of light and the corresponding Doppler effect with the velocity of the source at the time of detection, instead of the time of emission, it is possible to explain quantitatively and qualitatively the spacecraft anomalies. Also, a formulation of electromagnetism compatible with this conception is possible (and also compatible with the known electromagnetic phenomena). Under this theory the influence of the velocity of the source in the speed of light is somewhat subtle in many practical situations and probably went unnoticed in other phenomena.

  15. Micro-ionics: next generation power sources.

    Science.gov (United States)

    Tuller, Harry L; Litzelman, Scott J; Jung, Woochul

    2009-05-07

    The desire for ever smarter systems-on-a-chip and plug-free portable electronics with longer operating times between recharge has stimulated growing interest in micro-ionic systems. The use of thin film and photolithographic processing techniques, commonly at temperatures considerably below those utilized in conventional ceramics processing methods, leads to ionic or mixed ionic-electronic materials with nanosized dimensions. The implications for nanosized grains on the conductivity of thin film solid oxide electrolytes are examined. Grain boundary engineering, as a means of controlling and ultimately enhancing transport along and across grain boundaries, becomes essential given that such boundaries often dominate the transport properties of such nano-dimensioned materials. Heterogeneous doping by selective in-diffusion along grain boundaries was introduced as a potentially powerful means of achieving this. This is coupled with the modeling of space charge distributions at such boundaries, taking into account possible dopant segregation to the boundaries. The use of lithographic methods for generating geometrically well defined structures is used to illustrate how one can achieve a much improved understanding of electrode processes in SOFC structures. Indeed, the more idealized structures achievable by application of microelectronic processing provide a marvelous opportunity to uncover the science underlying the technology of micro- and ultimately macro-ionics.

  16. Intelligent pulse light source in the performance calibration system of two-dimensional neutron detector

    Science.gov (United States)

    Yang, Lei; Zhao, Xiao-Fang

    2017-07-01

    Chinese Spallation Neutron Source (CSNS) project will use numerous two-dimensional (2D) neutron detectors whose ZnS (Ag) scintillator is doped with 6Li. To ensure the consistency of all neutron detectors, a calibration system for the performance of 2D neutron detectors is designed. For radiation protection, the state control of the radiation source gets more and more strict. It is impossible to directly carry out experiments with massive radioactive particles. Thus, the following scheme has been designed. The controlled pulsed laser light source on a 2D mobile platform is used to replace the neutron bombardment to generate the photon. The pulse signal drives the laser diode to generate pulse light. The pulse light source located on the 2D platform is controlled by the core controller, and goes to the wavelength shift fiber through the optical fiber. The host computer (PC) receives the signal from the electronics system, processes data, and automatically calibrates the performance parameters. As shown by the experimental results, the pulse light source can perfectly meet all requirements of 2D neutron detector calibration system.

  17. Performance characteristics of white light sources consisting of multiple light-emitting diodes

    Science.gov (United States)

    Li, Yun-Li; Shah, Jay M.; Leung, P.-H.; Gessmann, Thomas; Schubert, E. F.

    2004-01-01

    The performance characteristics of white light sources based on a multiple-LED approach, in particular dichromatic and trichromatic sources are analyzed in detail. Figures of merit such as the luminous efficacy, color temperature, and color rendering capabilities are provided for a wide range of primary emission wavelengths. Spectral power density functions of LEDs are assumed to be thermally and inhomogeneously broadened to a full width at half maximum of several kT, in agreement with experimental results. A gaussian line shape is assumed for each of the emission bands. It is shown that multi-LED white light sources have the potential for luminous efficacies greater than 400 lm/W (dichromatic source) and color rendering indices of greater than 90 (trichromatic source). Contour maps for the color rendering indices and luminous efficacies versus three wavelengths are given.

  18. Beam conditions for radiation generated by an electromagnetic Hermite-Gaussian model source

    Institute of Scientific and Technical Information of China (English)

    LI Jia; XIN Yu; CHEN Yan-ru

    2011-01-01

    @@ Within the framework of the correlation theory of electromagnetic laser beams, the far field cross-spectral density matrix of the light radiated from an electromagnetic Hermite-Gaussian model source is derived.By utilizing the convergence property of Hermite polynomials, the conditions of the matrices for the source to generate an electromagnetic Hermite-Gaussian beam are obtained.Furthermore, in order to generate a scalar Hermite-Gaussian model beam, it is required that the source should be locally rather coherent in the spatial domain.

  19. Research on Primary Shielding Calculation Source Generation Codes

    Science.gov (United States)

    Zheng, Zheng; Mei, Qiliang; Li, Hui; Shangguan, Danhua; Zhang, Guangchun

    2017-09-01

    Primary Shielding Calculation (PSC) plays an important role in reactor shielding design and analysis. In order to facilitate PSC, a source generation code is developed to generate cumulative distribution functions (CDF) for the source particle sample code of the J Monte Carlo Transport (JMCT) code, and a source particle sample code is deveoped to sample source particle directions, types, coordinates, energy and weights from the CDFs. A source generation code is developed to transform three dimensional (3D) power distributions in xyz geometry to source distributions in r θ z geometry for the J Discrete Ordinate Transport (JSNT) code. Validation on PSC model of Qinshan No.1 nuclear power plant (NPP), CAP1400 and CAP1700 reactors are performed. Numerical results show that the theoretical model and the codes are both correct.

  20. Real-time Image Generation for Compressive Light Field Displays

    Science.gov (United States)

    Wetzstein, G.; Lanman, D.; Hirsch, M.; Raskar, R.

    2013-02-01

    With the invention of integral imaging and parallax barriers in the beginning of the 20th century, glasses-free 3D displays have become feasible. Only today—more than a century later—glasses-free 3D displays are finally emerging in the consumer market. The technologies being employed in current-generation devices, however, are fundamentally the same as what was invented 100 years ago. With rapid advances in optical fabrication, digital processing power, and computational perception, a new generation of display technology is emerging: compressive displays exploring the co-design of optical elements and computational processing while taking particular characteristics of the human visual system into account. In this paper, we discuss real-time implementation strategies for emerging compressive light field displays. We consider displays composed of multiple stacked layers of light-attenuating or polarization-rotating layers, such as LCDs. The involved image generation requires iterative tomographic image synthesis. We demonstrate that, for the case of light field display, computed tomographic light field synthesis maps well to operations included in the standard graphics pipeline, facilitating efficient GPU-based implementations with real-time framerates.

  1. Integrated Quantum Optics: Experiments towards integrated quantum-light sources and quantum-enhanced sensing

    DEFF Research Database (Denmark)

    Hoff, Ulrich Busk

    The work presented in this thesis is focused on experimental application and generation of continuous variable quantum correlated states of light in integrated dielectric structures. Squeezed states are among the most exploited continuous variable optical states for free-space quantum-enhanced se......The work presented in this thesis is focused on experimental application and generation of continuous variable quantum correlated states of light in integrated dielectric structures. Squeezed states are among the most exploited continuous variable optical states for free-space quantum...... in this thesis: Firstly, we present proof-of-principle demonstration of interfacing squeezed light with an on-chip optomechanical resonator, demonstrating a quantum-enhanced sensitivity to the vibrations of the micromechanical object. Secondly, work on developing an integrated source of squeezed light...

  2. Beam-based model of broad-band impedance of the Diamond Light Source

    Science.gov (United States)

    Smaluk, Victor; Martin, Ian; Fielder, Richard; Bartolini, Riccardo

    2015-06-01

    In an electron storage ring, the interaction between a single-bunch beam and a vacuum chamber impedance affects the beam parameters, which can be measured rather precisely. So we can develop beam-based numerical models of longitudinal and transverse impedances. At the Diamond Light Source (DLS) to get the model parameters, a set of measured data has been used including current-dependent shift of betatron tunes and synchronous phase, chromatic damping rates, and bunch lengthening. A matlab code for multiparticle tracking has been developed. The tracking results and analytical estimations are quite consistent with the measured data. Since Diamond has the shortest natural bunch length among all light sources in standard operation, the studies of collective effects with short bunches are relevant to many facilities including next generation of light sources.

  3. Miniature field emission light sources for bio-chips

    Energy Technology Data Exchange (ETDEWEB)

    Cichy, Bartlomiej; Gorecka-Drzazga, Anna; Dziuban, Jan A [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, 50-372 Wroclaw (Poland)], E-mail: bartlomiej.cichy@pwr.wroc.pl

    2009-01-01

    A concept based on preparation of miniature field emission light sources (FELS) for integration with bio-chips is presented. Glass and silicon-glass micro-fluidic systems (biochips) with spectrofluorometric detection are designated for this solution. Planar, miniature silicon-glass field emission light sources were designed and fabricated for this conception. Carbon nanotubes (CNTs) have been used as a low-voltage electron emissive layer. Nanocrystalline yttria matrices doped with rare earth (Re) ions (Re: Eu{sup 3+}, Tb{sup 3+}) have been synthesized and utilized as phosphor layers. Light emission spectral characteristics of fabricated sources allow to couple them with typical fluorescent markers as e.g. Alexa, Fluorescein or TO-PRO, used on the wide scale in biochemical researches. Fabricated FELSs are characterized by the intensive and homogenous light emission with well defined sharp emission lines. The efficient and stable field emission from carbon nanotubes has also been noticed. Fabricated FELS are technologically compatible with highly developing micromachined fluidic systems and are able to direct on-chip integration with these microsystems.

  4. Advanced Light Source activity report 1996/97

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    Ten years ago, the Advanced Light Source (ALS) existed as a set of drawings, calculations, and ideas. Four years ago, it stored an electron beam for the first time. Today, the ALS has moved from those ideas and beginnings to a robust, third-generation synchrotron user facility, with eighteen beam lines in use, many more in planning or construction phases, and hundreds of users from around the world. Progress from concepts to realities is continuous as the scientific program, already strong in many diverse areas, moves in new directions to meet the needs of researchers into the next century. ALS staff members who develop and maintain the infrastructure for this research are similarly unwilling to rest on their laurels. As a result, the quality of the photon beams the authors deliver, as well as the support they provide to users, continues to improve. The ALS Activity Report is designed to share the results of these efforts in an accessible form for a broad audience. The Scientific Program section, while not comprehensive, shares the breadth, variety, and interest of recent research at the ALS. (The Compendium of User Abstracts and Technical Reports provides a more comprehensive and more technical view.) The Facility Report highlights progress in operations, ongoing accelerator research and development, and beamline instrumentation efforts. Although these Activity Report sections are separate, in practice the achievements of staff and users at the ALS are inseparable. User-staff collaboration is essential as they strive to meet the needs of the user community and to continue the ALS's success as a premier research facility.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, S.L. [Design and Accelerator Operations Consulting, 568 Wintergreen Ct Ridge, NY 11961 (United States); Ghosh, V.J.; Breitfeller, M. [NSLS-II, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2016-08-11

    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.

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

    Science.gov (United States)

    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.

  7. LNLS: light source, beamlines, end stations and scientific instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Vicentin, Flavio Cesar [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil)

    2012-07-01

    Full text: The LNLS is operational since 1997 and has a second-generation light source with a 1,37GeV electron storage ring and 2,08 keV critical energy. Besides the storage ring there are various beamlines installed mainly in magnetic dipoles, however were opened three beamlines based in insertion devices, wiggler and undulator. The LNLS is now operating with 16 beamlines which are open to the external user community: 9 of them are dedicated to structural studies and the other 7 to spectroscopic techniques. The beamlines devoted to structural studies involve X-ray diffraction (XRD1, XRD2, XPD and XDS), small-angle X-ray scattering (SAXS1 and SAXS2), protein crystallography (MX1 and MX2) and X-ray fluorescence (XRF). The beamlines dedicated to spectroscopic studies are X-ray absorption fine structure (XAFS1, XAFS2 and DXAS), soft X-ray spectroscopy (SXS), spherical grating monochromator (SGM), plane grating monochromator (PGM) and toroidal grating monochromator (TGM). Two more beamlines are expected to begin their operation in 2012: X-ray tomography and infrared spectroscopy. Each beamline has its own characteristics in terms of photon energy range, flux, resolution and beam size, but many of the optical elements and instrumentation are common to various beamlines and the main are mirrors, monochromators (crystal and diffraction grating), slits and filters. For X-ray and VUV spectroscopy, several experimental techniques can be explored including XAS, XMCD, XMLD, XPS, AES, UPS, XEOL, reflectivity and PePiCo. For that, these beamlines share different end stations and instrumentation that can be easily installed and commissioned for attend a specific experiment. (author)

  8. Dielectric Wakefield Accelerator to drive the future FEL Light Source.

    Energy Technology Data Exchange (ETDEWEB)

    Jing, C.; Power, J.; Zholents, A. (Accelerator Systems Division (APS)); ( HEP); (LLC)

    2011-04-20

    X-ray free-electron lasers (FELs) are expensive instruments and a large part of the cost of the entire facility is driven by the accelerator. Using a high-energy gain dielectric wake-field accelerator (DWA) instead of the conventional accelerator may provide a significant cost saving and reduction of the facility size. In this article, we investigate using a collinear dielectric wakefield accelerator to provide a high repetition rate, high current, high energy beam to drive a future FEL x-ray light source. As an initial case study, a {approx}100 MV/m loaded gradient, 850 GHz quartz dielectric based 2-stage, wakefield accelerator is proposed to generate a main electron beam of 8 GeV, 50 pC/bunch, {approx}1.2 kA of peak current, 10 x 10 kHz (10 beamlines) in just 100 meters with the fill factor and beam loading considered. This scheme provides 10 parallel main beams with one 100 kHz drive beam. A drive-to-main beam efficiency {approx}38.5% can be achieved with an advanced transformer ratio enhancement technique. rf power dissipation in the structure is only 5 W/cm{sup 2} in the high repetition rate, high gradient operation mode, which is in the range of advanced water cooling capability. Details of study presented in the article include the overall layout, the transform ratio enhancement scheme used to increase the drive to main beam efficiency, main wakefield linac design, cooling of the structure, etc.

  9. Silicon-Based Light Sources for Silicon Integrated Circuits

    Directory of Open Access Journals (Sweden)

    L. Pavesi

    2008-01-01

    Full Text Available Silicon the material per excellence for electronics is not used for sourcing light due to the lack of efficient light emitters and lasers. In this review, after having introduced the basics on lasing, I will discuss the physical reasons why silicon is not a laser material and the approaches to make it lasing. I will start with bulk silicon, then I will discuss silicon nanocrystals and Er3+ coupled silicon nanocrystals where significant advances have been done in the past and can be expected in the near future. I will conclude with an optimistic note on silicon lasing.

  10. Excitation of anodized alumina films with a light source

    DEFF Research Database (Denmark)

    Aggerbeck, Martin; Canulescu, Stela; Rechendorff, K.;

    . The UV-VIS reflectance of Ti-doped anodized aluminium films was measured over the wavelength range of 200 nm to 900 nm. Titanium doped-anodized aluminium films with 5-15 wt% Ti were characterized. Changes in the diffuse light scattering of doped anodized aluminium films, and thus optical appearance......Optical properties of anodized aluminium alloys were determined by optical diffuse reflectance spectroscopy of such films. Samples with different concentrations of dopants were excited with a white-light source combined with an integrating sphere for fast determination of diffuse reflectance...

  11. Matter from light-light scattering via Breit-Wheeler events produced by two interacting Compton sources

    Science.gov (United States)

    Drebot, Illya; Micieli, D.; Milotti, E.; Petrillo, V.; Tassi, E.; Serafini, L.

    2017-04-01

    We present the dimensioning of a photon-photon collider based on Compton gamma sources for the observation of Breit-Wheeler pair production and QED γ γ events. Two symmetric electron beams, generated by photocathodes and accelerated in linacs, produce two gamma ray beams through Compton back scattering with two J-class lasers. Tuning the system energy above the Breit-Wheeler cross section threshold, a flux of electron-positron pairs is generated out of light-light interaction. The process is analyzed by start-to-end simulations. Realistic numbers of the secondary particle yield, referring to existing state-of-the-art set-ups and a discussion of the feasibility of the experiment taking into account the background signal are presented.

  12. Direct Seeded Single Frequency mid-IR OPA all Passive Light Source

    DEFF Research Database (Denmark)

    Høgstedt, Lasse; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    2013-01-01

    We present a two stage pulsed mid-infrared light source based on nonlinear downconversion of light. The light source is single frequency, tunable, all passive, single moded and build with standard optical components.......We present a two stage pulsed mid-infrared light source based on nonlinear downconversion of light. The light source is single frequency, tunable, all passive, single moded and build with standard optical components....

  13. The advanced light source: America`s brightest light for science and industry

    Energy Technology Data Exchange (ETDEWEB)

    Cross, J.; Lawler, G.

    1994-03-01

    America`s brightest light comes from the Advanced Light Source (ALS), a national facility for scientific research, product development, and manufacturing. Completed in 1993, the ALS produces light in the ultraviolet and x-ray regions of the spectrum. Its extreme brightness provides opportunities for scientific and technical progress not possible anywhere else. Technology is poised on the brink of a major revolution - one in which vital machine components and industrial processes will be drastically miniaturized. Industrialized nations are vying for leadership in this revolution - and the huge economic rewards the leaders will reap.

  14. Source Term Model for an Array of Vortex Generator Vanes

    Science.gov (United States)

    Buning, P. G. (Technical Monitor); Waithe, Kenrick A.

    2003-01-01

    A source term model was developed for numerical simulations of an array of vortex generators. The source term models the side force created by a vortex generator being modeled. The model is obtained by introducing a side force to the momentum and energy equations that can adjust its strength automatically based on a local flow. The model was tested and calibrated by comparing data from numerical simulations and experiments of a single low-profile vortex generator vane, which is only a fraction of the boundary layer thickness, over a flat plate. The source term model allowed a grid reduction of about seventy percent when compared with the numerical simulations performed on a fully gridded vortex generator without adversely affecting the development and capture of the vortex created. The source term model was able to predict the shape and size of the stream wise vorticity and velocity contours very well when compared with both numerical simulations and experimental data.

  15. Simplified Generation of High-Angular-Momentum Light Beams

    Science.gov (United States)

    Savchenkov, Anatoliy; Maleki, Lute; Matsko, Andrey; Strekalov, Dmitry; Grudinin, Ivan

    2007-01-01

    A simplified method of generating a beam of light having a relatively high value of angular momentum (see figure) involves the use of a compact apparatus consisting mainly of a laser, a whispering- gallery-mode (WGM) resonator, and optical fibers. The method also can be used to generate a Bessel beam. ( Bessel beam denotes a member of a class of non-diffracting beams, so named because their amplitudes are proportional to Bessel functions of the radii from their central axes. High-order Bessel beams can have high values of angular momentum.) High-angular-momentum light beams are used in some applications in biology and nanotechnology, wherein they are known for their ability to apply torque to make microscopic objects rotate. High-angular-momentum light beams could also be used to increase bandwidths of fiber-optic communication systems. The present simplified method of generating a high-angular-momentum light beam was conceived as an alternative to prior such methods, which are complicated and require optical setups that include, variously, holograms, modulating Fabry-Perot cavities, or special microstructures. The present simplified method exploits a combination of the complex structure of the electromagnetic field inside a WGM resonator, total internal reflection in the WGM resonator, and the electromagnetic modes supported by an optical fiber. The optical fiber used to extract light from the WGM resonator is made of fused quartz. The output end of this fiber is polished flat and perpendicular to the fiber axis. The input end of this fiber is cut on a slant and placed very close to the WGM resonator at an appropriate position and orientation. To excite the resonant whispering- gallery modes, light is introduced into the WGM resonator via another optical fiber that is part of a pigtailed fiber-optic coupler. Light extracted from the WGM resonator is transformed into a high-angular- momentum beam inside the extraction optical fiber and this beam is emitted from the

  16. Dynamic light scattering on bioconjugated laser generated gold nanoparticles.

    Science.gov (United States)

    Zimbone, Massimo; Baeri, Pietro; Calcagno, Lucia; Musumeci, Paolo; Contino, Annalinda; Barcellona, Maria Luisa; Bonaventura, Gabriele

    2014-01-01

    Gold nanoparticles (AuNPs) conjugated to DNA are widely used for biomedical targeting and sensing applications. DNA functionalization is easily reached on laser generated gold nanoparticles because of their unique surface chemistry, not reproducible by other methods. In this context, we present an extensive investigation concerning the attachment of DNA to the surface of laser generated nanoparticles using Dynamic Light Scattering and UV-Vis spectroscopy. The DNA conjugation is highlighted by the increase of the hydrodynamic radius and by the UV-Vis spectra behavior. Our investigation indicates that Dynamic Light Scattering is a suitable analytical tool to evidence, directly and qualitatively, the binding between a DNA molecule and a gold nanoparticle, therefore it is ideal to monitor changes in the conjugation process when experimental conditions are varied.

  17. Dynamic light scattering on bioconjugated laser generated gold nanoparticles.

    Directory of Open Access Journals (Sweden)

    Massimo Zimbone

    Full Text Available Gold nanoparticles (AuNPs conjugated to DNA are widely used for biomedical targeting and sensing applications. DNA functionalization is easily reached on laser generated gold nanoparticles because of their unique surface chemistry, not reproducible by other methods. In this context, we present an extensive investigation concerning the attachment of DNA to the surface of laser generated nanoparticles using Dynamic Light Scattering and UV-Vis spectroscopy. The DNA conjugation is highlighted by the increase of the hydrodynamic radius and by the UV-Vis spectra behavior. Our investigation indicates that Dynamic Light Scattering is a suitable analytical tool to evidence, directly and qualitatively, the binding between a DNA molecule and a gold nanoparticle, therefore it is ideal to monitor changes in the conjugation process when experimental conditions are varied.

  18. Synchrotron light sources and free-electron lasers accelerator physics, instrumentation and science applications

    CERN Document Server

    Khan, Shaukat; Schneider, Jochen; Hastings, Jerome

    2016-01-01

    Hardly any other discovery of the nineteenth century did have such an impact on science and technology as Wilhelm Conrad Röntgen’s seminal find of the X-rays. X-ray tubes soon made their way as excellent instruments for numerous applications in medicine, biology, materials science and testing, chemistry and public security. Developing new radiation sources with higher brilliance and much extended spectral range resulted in stunning developments like the electron synchrotron and electron storage ring and the freeelectron laser. This handbook highlights these developments in fifty chapters. The reader is given not only an inside view of exciting science areas but also of design concepts for the most advanced light sources. The theory of synchrotron radiation and of the freeelectron laser, design examples and the technology basis are presented. The handbook presents advanced concepts like seeding and harmonic generation, the booming field of Terahertz radiation sources and upcoming brilliant light sources dri...

  19. Light sources for high-volume manufacturing EUV lithography: technology, performance, and power scaling

    Science.gov (United States)

    Fomenkov, Igor; Brandt, David; Ershov, Alex; Schafgans, Alexander; Tao, Yezheng; Vaschenko, Georgiy; Rokitski, Slava; Kats, Michael; Vargas, Michael; Purvis, Michael; Rafac, Rob; La Fontaine, Bruno; De Dea, Silvia; LaForge, Andrew; Stewart, Jayson; Chang, Steven; Graham, Matthew; Riggs, Daniel; Taylor, Ted; Abraham, Mathew; Brown, Daniel

    2017-06-01

    Extreme ultraviolet (EUV) lithography is expected to succeed in 193-nm immersion multi-patterning technology for sub-10-nm critical layer patterning. In order to be successful, EUV lithography has to demonstrate that it can satisfy the industry requirements in the following critical areas: power, dose stability, etendue, spectral content, and lifetime. Currently, development of second-generation laser-produced plasma (LPP) light sources for the ASML's NXE:3300B EUV scanner is complete, and first units are installed and operational at chipmaker customers. We describe different aspects and performance characteristics of the sources, dose stability results, power scaling, and availability data for EUV sources and also report new development results.

  20. Current schemes for National Synchrotron Light Source UV beamlines

    Energy Technology Data Exchange (ETDEWEB)

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

    1979-01-01

    We describe in some detail four beamlines proposed for the National Synchrotron Light Source uv ring at Brookhaven National Laboratory. Three grazing-incidence instruments, one of the plane grating Mijake type and two with toroidal gratings at grazing angles of 2-1/2/sup 0/ and 15/sup 0/ are described. Two normal incidence instruments, one using the source as entrance slit and accepting 75 milliradians horizontally are also discussed. In each case we have estimated the output fluxes expected from such beamlines.

  1. Calibration of space instruments at the Metrology Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R., E-mail: roman.klein@ptb.de; Fliegauf, R.; Gottwald, A.; Kolbe, M.; Paustian, W.; Reichel, T.; Richter, M.; Thornagel, R.; Ulm, G. [Physikalisch-Technische Bundesanstalt (PTB), Berlin (Germany)

    2016-07-27

    PTB has more than 20 years of experience in the calibration of space-based instruments using synchrotron radiation to cover the UV, VUV and X-ray spectral range. New instrumentation at the electron storage ring Metrology Light Source (MLS) opens up extended calibration possibilities within this framework. In particular, the set-up of a large vacuum vessel that can accommodate entire space instruments opens up new prospects. Moreover, a new facility for the calibration of radiation transfer source standards with a considerably extended spectral range has been put into operation. Besides, characterization and calibration of single components like e.g. mirrors, filters, gratings, and detectors is continued.

  2. Development of 250W EUV light source for HVM lithography

    Science.gov (United States)

    Mizoguchi, Hakaru; Nakarai, Hiroaki; Abe, Tamotsu; Nowak, Krzysztof M.; Kawasuji, , Yasufumi; Tanaka, Hiroshi; Watanabe, Yukio; Hori, Tsukasa; Kodama, Takeshi; Shiraishi, Yutaka; Yanagida, Tatsuya; Yamada, Tsuyoshi; Yamazaki, Taku; Okazaki, Shinji; Saitou, Takashi

    2017-02-01

    We have been developing CO2-Sn-LPP EUV light source which is the most promising solution as the 13.5nm high power light source for HVM EUVL since 2003. Unique original technologies such as; combination of pulsed CO2 laser and Sn droplets, dual wavelength laser pulse shooting and mitigation with magnetic field have been developed in Gigaphoton Inc.. The theoretical and experimental data have clearly showed the advantage of our proposed strategy. We demonstrated 117W EUV power (I/F clean in burst), 50 kHz, 22 hours stable operation at Pilot #1 device. Target of this device is 250 W EUV power by 27 kW pulsed CO2 driver laser system.

  3. Cathode R&D for Future Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, D.H.; /SLAC; Bazarov, I.; Dunham, B.; /Cornell U., CLASSE; Harkay, K.; /Argonne; Hernandez-Garcia; /Jefferson Lab; Legg, R.; /Wisconsin U., SRC; Padmore, H.; /LBL, Berkeley; Rao, T.; Smedley, J.; /Brookhaven; Wan, W.; /LBL, Berkeley

    2010-05-26

    This paper reviews the requirements and current status of cathodes for accelerator applications, and proposes a research and development plan for advancing cathode technology. Accelerator cathodes need to have long operational lifetimes and produce electron beams with a very low emittance. The two principal emission processes to be considered are thermionic and photoemission with the photocathodes being further subdivided into metal and semi-conductors. Field emission cathodes are not included in this analysis. The thermal emittance is derived and the formulas used to compare the various cathode materials. To date, there is no cathode which provides all the requirements needed for the proposed future light sources. Therefore a three part research plan is described to develop cathodes for these future light source applications.

  4. The Development of the Linac Coherent Light Source RF Gun

    CERN Document Server

    Dowell, David H; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling

    2015-01-01

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL). In addition to many other stringent requirements, the LCLS XFEL requires extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. This paper describes the analysis and design improvements of the BNL/SLAC/UCLA s-band gun leading to achievement of the LCLS performance goals.

  5. Efficient photochemical generation of peroxycarboxylic nitric anhydrides with ultraviolet light emitting diodes

    Directory of Open Access Journals (Sweden)

    N. D. Rider

    2015-01-01

    Full Text Available Photochemical sources of peroxycarboxylic nitric anhydrides (PANs are utilized in many atmospheric measurement techniques for calibration or to deliver an internal standard. Conventionally, such sources rely on phosphor-coated low-pressure mercury (Hg lamps to generate the UV light necessary to photo-dissociate a dialkyl ketone (usually acetone in the presence of a calibrated amount of nitric oxide (NO and oxygen (O2. In this manuscript, a photochemical PAN source in which the Hg lamp has been replaced by arrays of ultraviolet light-emitting diodes (UV-LEDs is described. The output of the UV-LED source was analyzed by gas chromatography (PAN-GC and thermal dissociation cavity ring-down spectroscopy (TD-CRDS. Using acetone, diethyl ketone (DIEK, diisopropyl ketone (DIPK, or di-n-propyl ketone (DNPK, respectively, the source produces peroxyacetic (PAN, peroxypropionic (PPN, peroxyisobutanoic (PiBN, or peroxy-n-butanoic nitric anhydride (PnBN from NO in high yield (> 90%. Box model simulations with a subset of the Master Chemical Mechanism (MCM were carried out to rationalize products yields and to identify side products. The use of UV-LED arrays offers many advantages over conventional Hg lamp setups, including greater light output over a narrower wavelength range, lower power consumption, and minimal generation of heat.

  6. Lasers or light sources for treating port-wine stains

    DEFF Research Database (Denmark)

    Faurschou, Annesofie; Olesen, Anne Braae; Leonardi-Bee, Jo;

    2011-01-01

    Port-wine stains are birthmarks caused by malformations of blood vessels in the skin. Port-wine stains manifest themselves in infancy as a flat, red mark and do not regress spontaneously but may, if untreated, become darker and thicker in adult life. The profusion of various lasers and light...... sources makes it difficult to decide which equipment is the best for treating port-wine stains....

  7. Minimum emittance of isochronus rings for synchrotron light source

    CERN Document Server

    Shoji, Y

    1999-01-01

    Theoretically achievable minimum emittances of isochronus rings for synchrotron light source are calculated. The rings discussed in this paper consist of isochronus and achromatic bending cells, isochronus TBA (triple bend achromat) cells with negative dispersion, isochronus TBA cells with inverse bends or isochronus QBA (four bend achromat) cells. We show that the minimum emittances of these rings are roughly 2 or 3 times of those of the optimized non-isochronus rings.

  8. Visible light scatter as quantitative information source on milk constituents

    DEFF Research Database (Denmark)

    Melentieva, Anastasiya; Kucheryavskiy, Sergey; Bogomolov, Andrey

    2012-01-01

    VISIBLE LIGHT SCATTER AS A QUANTITATIVE INFORMATION SOURCE ON MILK CONSTITUENTS A. Melenteva 1, S. Kucheryavski 2, A. Bogomolov 1,31Samara State Technical University, Molodogvardeyskaya Street 244, 443100 Samara, Russia. 2Aalborg University, campus Esbjerg, Niels Bohrs vej 8, 6700 Esbjerg, Denmar...... research area are presented and discussed. References: [1] A. Bogomolov, S. Dietrich, B. Boldrini, R.W. Kessler, Food Chemistry (2012), doi:10.1016/j.foodchem.2012.02.077....

  9. Application research of tune measurement system in Hefei light source

    CERN Document Server

    Sun Bao Gen; Xu Hong Liang; Lu Ping; Wang Jun; Gao Yun Feng; Wang Li; LiuJinYing

    2002-01-01

    The author introduces the measurement and research of some beam parameters using tune measurement system for Hefei Light Source (HLS), which include the betatron tune, beta function, natural chromaticity, corrected chromaticity, and central frequency. Additionally, it also describes the measurement of the influence of DC clearing electrodes on the betatron tune shift and gives some measurement results. The measurement results are compared with the theoretical values and they are in good agreement

  10. Experimental stations at I13 beamline at Diamond Light Source

    Science.gov (United States)

    Pešić, Z. D.; De Fanis, A.; Wagner, U.; Rau, C.

    2013-03-01

    The I13 beamline of Diamond Light Source has been operational since December 2011. The beamline encompass two fully independent branches devoted to coherent imaging experiments (coherent x-ray diffraction, coherent diffraction imaging and ptychography) and x-ray imaging (in-line phase contrast imaging, tomography and full-field microscopy). This paper gives an overview of the current status of experimental stations on both branches and outlines planned developments.

  11. Advances in high-order harmonic generation sources for time-resolved investigations

    Energy Technology Data Exchange (ETDEWEB)

    Reduzzi, Maurizio [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Institute of Photonics and Nanotechnologies, CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Carpeggiani, Paolo [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Kühn, Sergei [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); Calegari, Francesca [Institute of Photonics and Nanotechnologies, CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Nisoli, Mauro; Stagira, Salvatore [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Institute of Photonics and Nanotechnologies, CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Vozzi, Caterina [Institute of Photonics and Nanotechnologies, CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Dombi, Peter [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); Wigner Research Center for Physics, 1121 Budapest (Hungary); Kahaly, Subhendu [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); Tzallas, Paris; Charalambidis, Dimitris [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); Foundation for Research and Technology – Hellas, Institute of Electronic Structure and Lasers, P.O. Box 1527, GR-711 10 Heraklion, Crete (Greece); Varju, Katalin [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); Department of Optics and Quantum Electronics, University of Szeged, Dóm tér 9, 6720 Szeged (Hungary); Osvay, Karoly [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); and others

    2015-10-15

    We review the main research directions ongoing in the development of extreme ultraviolet sources based on high-harmonic generation for the synthesization and application of trains and isolated attosecond pulses to time-resolved spectroscopy. A few experimental and theoretical works will be discussed in connection to well-established attosecond techniques. In this context, we present the unique possibilities offered for time-resolved investigations on the attosecond timescale by the new Extreme Light Infrastructure Attosecond Light Pulse Source, which is currently under construction.

  12. Production of reactive oxygen species from photosensitizers activated with visible light sources available in dental offices.

    Science.gov (United States)

    Bouillaguet, Serge; Wataha, John C; Zapata, Oscar; Campo, Marino; Lange, Norbert; Schrenzel, Jacques

    2010-08-01

    The aim of this study was to assess the ability of commonly available red- or blue-light dental sources to generate reactive oxygen species (ROS) from photosensitive chemicals that might be useful for photodynamic antimicrobial chemotherapy (PACT). Although the use of red diode lasers is well documented, there is limited information on how useful blue-light sources might be for PACT in dental contexts. A diode laser (Periowave; see Table 1 for material and equipment sources) emitting red light (660-675 nm) was used to activate toluidine blue; riboflavin and pheophorbide-a polylysine (pheophorbide-a-PLL) were photoactivated using an Optilux 501 curing unit emitting blue light (380-500 nm). Ozone gas (generated by OzoTop, Tip Top Tips, Rolle, Switzerland), sodium hypochlorite, and hydrogen peroxide were used for comparison. ROS production was estimated using an iodine-triiodide colorimetric assay, and ROS levels were plotted versus concentration of chemicals to determine each chemical's efficiency in ROS production. One-way ANOVA with Tukey post hoc analysis (alpha = 0.05) was used to compare the efficiencies of ROS production for the various chemicals. Sodium hypochlorite, hydrogen peroxide, and ozone gas produced ROS spontaneously, whereas pheophorbide-a-PLL, riboflavin, and toluidine blue required light exposure. The efficiency of ROS production was higher for pheophorbide-a-PLL and toluidine blue than for ozone gas or riboflavin (p < 0.05). Hydrogen peroxide was the least efficient ROS producer. The results of the current study support the use of blue- or red-light-absorbing photosensitizers as candidates to produce ROS for clinical applications. Blue-light photosensitizers were as efficient as red-light photosensitizers in producing ROS and more efficient than the oxidant chemicals currently used for dental disinfection.

  13. Quantification of dust generating sources in gold and platinum mines

    CSIR Research Space (South Africa)

    Biffi, M

    2003-03-01

    Full Text Available dust generation rates linked to activities presumed to be hazardous in this respect. The aim of this study was to identify prominent dust sources that occur in hard rock mines and to characterise these by means of on-site measurement of dust generations...

  14. A novel photocatalytic conversion of Tryptophan to Kynurenine using black light as a light source

    NARCIS (Netherlands)

    Hamdy Mohamed Saad, M.S.; Scott, E.L.; Carr, R.H.; Sanders, J.P.M.

    2012-01-01

    The photocatalytic conversion of an aqueous solution of l-tryptophan (Trp) to kynurenine (KN) was investigated under the illumination of different light sources. Results show that Trp converted to KN with a selectivity of 64% under the illumination of a medium pressure (MP) Hg lamp. KN selectivity w

  15. Stray light in cone beam optical computed tomography: II. Reduction using a convergent light source.

    Science.gov (United States)

    Dekker, Kurtis H; Battista, Jerry J; Jordan, Kevin J

    2016-04-07

    Optical cone beam computed tomography (CBCT) using a broad beam and CCD camera is a fast method for densitometry of 3D optical gel dosimeters. However, diffuse light sources introduce considerable stray light into the imaging system, leading to underestimation of attenuation coefficients and non-uniformities in CT images unless corrections are applied to each projection image. In this study, the light source of a commercial optical CT scanner is replaced with a convergent cone beam source consisting of almost exclusively image forming primary rays. The convergent source is achieved using a small isotropic source and a Fresnel lens. To characterize stray light effects, full-field cone beam CT imaging is compared to fan beam CT (FBCT) using a 1 cm high fan beam aperture centered on the optic axis of the system. Attenuating liquids are scanned within a large 96 mm diameter uniform phantom and in a small 13.5 mm diameter finger phantom. For the uniform phantom, cone and fan beam CT attenuation coefficients agree within a maximum deviation of (1  ±  2)% between mean values over a wide range from 0.036 to 0.43 cm(-1). For the finger phantom, agreement is found with a maximum deviation of (4  ±  2)% between mean values over a range of 0.1-0.47 cm(-1). With the convergent source, artifacts associated with refractive index mismatch and vessel optical features are more pronounced. Further optimization of the source size to achieve a balance between quantitative accuracy and artifact reduction should enable practical, accurate 3D dosimetry, avoiding time consuming 3D scatter measurements.

  16. Stray light in cone beam optical computed tomography: II. Reduction using a convergent light source

    Science.gov (United States)

    Dekker, Kurtis H.; Battista, Jerry J.; Jordan, Kevin J.

    2016-04-01

    Optical cone beam computed tomography (CBCT) using a broad beam and CCD camera is a fast method for densitometry of 3D optical gel dosimeters. However, diffuse light sources introduce considerable stray light into the imaging system, leading to underestimation of attenuation coefficients and non-uniformities in CT images unless corrections are applied to each projection image. In this study, the light source of a commercial optical CT scanner is replaced with a convergent cone beam source consisting of almost exclusively image forming primary rays. The convergent source is achieved using a small isotropic source and a Fresnel lens. To characterize stray light effects, full-field cone beam CT imaging is compared to fan beam CT (FBCT) using a 1 cm high fan beam aperture centered on the optic axis of the system. Attenuating liquids are scanned within a large 96 mm diameter uniform phantom and in a small 13.5 mm diameter finger phantom. For the uniform phantom, cone and fan beam CT attenuation coefficients agree within a maximum deviation of (1  ±  2)% between mean values over a wide range from 0.036 to 0.43 cm-1. For the finger phantom, agreement is found with a maximum deviation of (4  ±  2)% between mean values over a range of 0.1-0.47 cm-1. With the convergent source, artifacts associated with refractive index mismatch and vessel optical features are more pronounced. Further optimization of the source size to achieve a balance between quantitative accuracy and artifact reduction should enable practical, accurate 3D dosimetry, avoiding time consuming 3D scatter measurements.

  17. Sole-Source Lighting for Controlled-Environment Agriculture

    Science.gov (United States)

    Mitchell.Cary; Stutte, Gary W.

    2015-01-01

    Since plants on Earth evolved under broad-spectrum solar radiation, anytime they are grown exclusively under electric lighting that does not contain all wavelengths in similar proportion to those in sunlight, plant appearance and size could be uniquely different. Nevertheless, plants have been grown for decades under fluorescent (FL) (1) + incandescent (IN) (2) lamps as a sole source of lighting (SSL), and researchers have become comfortable that, in certain proportions of FL + IN for a given species, plants can appear "normal" relative to their growth outdoors. The problem with using such traditional SSLs for commercial production typically is short lamp lifespans and not obtaining enough photosynthetically active radiation (PAR, 400-700 nm) when desired. These limitations led to supplementation of FL + IN lamp outputs with longer-lived, high-intensity discharge (HID) lamps in growth chambers (3). As researchers became comfortable that mixes of orange-biased high-pressure sodium (HPS) and blue-biased metal halide (MH) HIDs together also could give normal plant growth at higher intensities, growth chambers and phytotrons subsequently were equipped mainly with HID lamps, with their intense thermal output filtered out by ventilated light caps or thermal-controlled water barriers. For the most part, IN and HID lamps have found a home in commercial protected horticulture, usually for night-break photoperiod lighting (IN) or for seasonal supplemental lighting (mostly HPS) in greenhouses. However, lack of economically viable options for SSL have held back aspects of year-round indoor agriculture from taking off commercially.

  18. Precision Calibration via Artificial Light Sources Above the Atmosphere

    Science.gov (United States)

    Albert, J. E.; Fagin, M. H.; Brown, Y. J.; Stubbs, C. W.; Kuklev, N. A.; Conley, A. J.

    2016-05-01

    Deeper understanding of the properties of dark energy via SNIa surveys, and to a large extent other methods as well, will require unprecedented photometric precision. Laboratory and solar photometry and radiometry regularly achieve precisions on the order of parts in ten thousand, but photometric calibration for non-solar astronomy presently remains stuck at the percent or greater level. We discuss our project to erase this discrepancy, and our steps toward achieving laboratory-level photometric precision for surveys late this decade. In particular, we show near-field observations of the balloon-borne light source we are presently testing, in addition to previous work with a calibrated laser source presently in low-Earth orbit. Our technique is additionally applicable to microwave astronomy. Observation of gravitational waves in the polarized CMB will similarly require unprecedented polarimetric and radiometric precision, and we briefly discuss our plans for a calibrated microwave source above the atmosphere as well.

  19. Linac Coherent Light Source: The first five years

    Science.gov (United States)

    Bostedt, Christoph; Boutet, Sébastien; Fritz, David M.; Huang, Zhirong; Lee, Hae Ja; Lemke, Henrik T.; Robert, Aymeric; Schlotter, William F.; Turner, Joshua J.; Williams, Garth J.

    2016-01-01

    A new scientific frontier opened in 2009 with the start of operations of the world's first x-ray free-electron laser (FEL), the Linac Coherent Light Source (LCLS), at SLAC National Accelerator Laboratory. LCLS provides femtosecond pulses of x rays (270 eV to 11.2 keV) with very high peak brightness to access new domains of ultrafast x-ray science. This article presents the fundamental FEL physics and outlines the LCLS source characteristics along with the experimental challenges, strategies, and instrumentation that accompany this novel type of x-ray source. The main part of the article reviews the scientific achievements since the inception of LCLS in the five primary areas it serves: atomic, molecular, and optical physics; condensed matter physics; matter in extreme conditions; chemistry and soft matter, and biology.

  20. Fully integrated quantum photonic circuit with an electrically driven light source

    Science.gov (United States)

    Khasminskaya, Svetlana; Pyatkov, Felix; Słowik, Karolina; Ferrari, Simone; Kahl, Oliver; Kovalyuk, Vadim; Rath, Patrik; Vetter, Andreas; Hennrich, Frank; Kappes, Manfred M.; Gol'Tsman, G.; Korneev, A.; Rockstuhl, Carsten; Krupke, Ralph; Pernice, Wolfram H. P.

    2016-11-01

    Photonic quantum technologies allow quantum phenomena to be exploited in applications such as quantum cryptography, quantum simulation and quantum computation. A key requirement for practical devices is the scalable integration of single-photon sources, detectors and linear optical elements on a common platform. Nanophotonic circuits enable the realization of complex linear optical systems, while non-classical light can be measured with waveguide-integrated detectors. However, reproducible single-photon sources with high brightness and compatibility with photonic devices remain elusive for fully integrated systems. Here, we report the observation of antibunching in the light emitted from an electrically driven carbon nanotube embedded within a photonic quantum circuit. Non-classical light generated on chip is recorded under cryogenic conditions with waveguide-integrated superconducting single-photon detectors, without requiring optical filtering. Because exclusively scalable fabrication and deposition methods are used, our results establish carbon nanotubes as promising nanoscale single-photon emitters for hybrid quantum photonic devices.

  1. Z - Source Multi Level Inverter Based PV Generation System

    Directory of Open Access Journals (Sweden)

    T. Lakhmi kanth

    2014-09-01

    Full Text Available In this paper a novel technique of Z-Source multilevel Inverter based PV Generation system is implemented and simulated using MATLAB-Simulink simulation software. The Photovoltaic cells are healthier option for converting solar energy into electricity. Due to high capital cost and low efficiency PV cells have not yet been a fully smart choice for electricity users. To enhance the performance of the system, Z-Source multi level inverter can be used in place of conventional Voltage Source Inverter (VSI in Solar Power Generation System. The PV cell model is developed using circuit mathematical equations. The Z-Source multilevel inverter is modeled to realize boosted DC to AC conversion (inversion with low THD. Outcome shows that the energy conversion efficiency of ZSMLI is a lot improved as compared to conventional voltage Source Inverter (VSI. By doing FFT analysis we can know the total THD.

  2. Beacon system based on light-emitting diode sources for runways lighting

    Science.gov (United States)

    Montes, Mario González; Vázquez, Daniel; Fernandez-Balbuena, Antonio A.; Bernabeu, Eusebio

    2014-06-01

    New aeronautical ground lighting techniques are becoming increasingly important to ensure the safety and reduce the maintenance costs of the plane's tracks. Until recently, tracks had embedded lighting systems whose sources were based on incandescent lamps. But incandescent lamps have several disadvantages: high energy consumption and frequent breakdowns that result in high maintenance costs (lamp average life-time is ˜1500 operating hours) and the lamp's technology has a lack of new lighting functions, such as signal handling and modification. To solve these problems, the industry has developed systems based on light-emitting diode (LED) technology with improved features: (1) LED lighting consumes one tenth the power, (2) it improves preventive maintenance (an LED's lifetime range is between 25,000 and 100,000 hours), and (3) LED lighting technology can be controlled remotely according to the needs of the track configuration. LEDs have been in use for more than three decades, but only recently, around 2002, have they begun to be used as visual aids, representing the greatest potential change for airport lighting since their inception in the 1920s. Currently, embedded LED systems are not being broadly used due to the specific constraints of the rules and regulations of airports (beacon dimensions, power system technology, etc.). The fundamental requirements applied to embedded lighting systems are to be hosted on a volume where the dimensions are usually critical and also to integrate all the essential components for operation. An embedded architecture that meets the lighting regulations for airport runways is presented. The present work is divided into three main tasks: development of an optical system to optimize lighting according to International Civil Aviation Organization, manufacturing prototype, and model validation.

  3. Generation of incoherent light from a laser diode based on the injection of an emission from a superluminescent diode

    CERN Document Server

    Takamizawa, Akifumi; Ikegami, Takeshi

    2013-01-01

    In this study, incoherent light with a spectral linewidth of 7 nm and 140 mW of power was generated from a laser diode into which incoherent light emitted from a superluminescent diode was injected with 2.7 mW of power. The spectral linewidth of the light from the laser diode was broadened to 12 nm when the diode's output power was reduced to 15 mW. In the process of transformation from single-mode laser light to incoherent light with a broad spectrum by increasing injection-light power, multimode laser oscillation and a noisy spectrum were found in the light from the laser diode. This optical system can be used not only for amplification of incoherent light but also as a coherence-convertible light source.

  4. Light source comprising a common substrate, a first led device and a second led device

    Science.gov (United States)

    Choong, Vi-En

    2010-02-23

    At least one stacked organic or polymeric light emitting diode (PLEDs) devices to comprise a light source is disclosed. At least one of the PLEDs includes a patterned cathode which has regions which transmit light. The patterned cathodes enable light emission from the PLEDs to combine together. The light source may be top or bottom emitting or both.

  5. Light emitting diode-generated blue light modulates fibrosis characteristics: fibroblast proliferation, migration speed, and reactive oxygen species generation.

    Science.gov (United States)

    Mamalis, Andrew; Garcha, Manveer; Jagdeo, Jared

    2015-02-01

    Blue light is part of the visible light spectrum that does not generate harmful DNA adducts associated with skin cancer and photoaging, and may represent a safer therapeutic modality for treatment of keloid scars and other fibrotic skin diseases. Our laboratory previously demonstrated that light-emitting diode (LED) red and infrared light inhibits proliferation of skin fibroblasts. Moreover, different wavelengths of light can produce different biological effects. Furthermore, the effects of LED blue light (LED-BL) on human skin fibroblasts are not well characterized. This study investigated the effects of LED-BL on human skin fibroblast proliferation, viability, migration speed, and reactive oxygen-species (ROS) generation. Irradiation of adult human skin fibroblasts using commercially-available LED-BL panels was performed in vitro, and modulation of proliferation and viability was quantified using the trypan blue dye exclusion assay, migratory speed was assessed using time-lapse video microscopy, and intracellular ROS generation was measured using the dihydrorhodamine flow cytometry assay. Statistical differences between groups were determined by ANOVA and Student's t-test. Human skin fibroblasts treated with LED-BL fluences of 5, 10, 15, 30, and 80 J/cm(2) demonstrated statistically significant dose-dependent decreases in relative proliferation of 8.4%, 29.1%, 33.8%, 51.7%, and 55.1%, respectively, compared to temperature and environment matched bench control plates, respectively. LED-BL fluences of 5, 30, 45, and 80 J/cm(2) decreased fibroblast migration speed to 95 ± 7.0% (P = 0.64), 81.3 ± 5.5% (P = 0.021), 48.5 ± 2.7% (P < 0.0001), and 32.3 ± 1.9% (P < 0.0001), respectively, relative to matched controls. LED fluences of 5, 10, 30, and 80 J/cm(2) resulted in statistically significant increases in reactive oxygen species of 110.4%, 116.6%, 127.5%, and 130%, respectively, relative to bench controls. At the fluences

  6. A liquid hydrocarbon deuteron source for neutron generators

    Science.gov (United States)

    Schwoebel, P. R.

    2017-06-01

    Experimental studies of a deuteron spark source for neutron generators using hydrogen isotope fusion reactions are reported. The ion source uses a spark discharge between electrodes coated with a deuterated hydrocarbon liquid, here Santovac 5, to inhibit permanent electrode erosion and extend the lifetime of high-output neutron generator spark ion sources. Thompson parabola mass spectra show that principally hydrogen and deuterium ions are extracted from the ion source. Hydrogen is the chief residual gas phase species produced due to source operation in a stainless-steel vacuum chamber. The prominent features of the optical emission spectra of the discharge are C+ lines, the hydrogen Balmer Hα-line, and the C2 Swan bands. Operation of the ion source was studied in a conventional laboratory neutron generator. The source delivered an average deuteron current of ˜0.5 A nominal to the target in a 5 μs duration pulse at 1 Hz with target voltages of -80 to -100 kV. The thickness of the hydrocarbon liquid in the spark gap and the consistency thereof from spark to spark influences the deuteron yield and plays a role in determining the beam-focusing characteristics through the applied voltage necessary to break down the spark gap. Higher breakdown voltages result in larger ion beam spots on the target and vice-versa. Because the liquid self-heals and thereby inhibits permanent electrode erosion, the liquid-based source provides long life, with 104 pulses to date, and without clear evidence that, in principle, the lifetime could not be much longer. Initial experiments suggest that an alternative cylindrical target-type generator design can extract approximately 10 times the deuteron current from the source. Preliminary data using the deuterated source liquid as a neutron-producing target are also presented.

  7. The Use of Light-Emitting Diodes (LEDs) as Green and Red/Far-Red Light Sources in Plant Physiology.

    Science.gov (United States)

    Jackson, David L.; And Others

    1985-01-01

    The use of green, red, and far-red light-emitting diodes (LEDs) as light sources for plant physiological studies is outlined and evaluated. Indicates that LED lamps have the advantage over conventional light sources in that they are lightweight, low-cost, portable, easily constructed, and do not require color filters. (Author/DH)

  8. Realizing the benefits of restored periodicity in the advanced light source

    Science.gov (United States)

    Robin, D.; Safranek, J.; Decking, W.

    1999-04-01

    An essential feature of third generation storage ring based light sources is the magnetic lattice is designed with a high degree of periodicity. Tracking simulations show that if the periodicity is perturbed (by focusing errors, for example), nonlinear resonances become excited, which causes a reduction in the dynamic aperture. Therefore it is important to have a method to measure and correct perturbed periodicity. In this paper we study the effect of broken and restored periodicity at an actual third generation light source: the Advanced Light Source at Lawrence Berkeley National Laboratory. First, we show that it is possible to accurately determine the storage ring optic and thus the perturbation of the periodicity by fitting measured orbit response matrices. This method allows us to determine individual field gradient errors in quadrupoles and closed orbit errors in sextupoles. By varying individual quadrupole field strengths it is possible to correct the optic, largely restoring the lattice periodicity. A comparison is made of the performance of the storage ring before and after the optic is corrected. Measurements of the electron beam tails and the synchrotron light image reveal a large suppression in resonance excitation after the optic is corrected. Correcting the optic also improves the injection efficiency.

  9. Enhanced Performance of the Advanced Light Source through Periodicity Restoration of the Linear Lattice

    Science.gov (United States)

    Robin, D.; Steier, C.; Safranek, J.; Decking, W.

    2002-01-01

    An essential feature of third generation storage ring based light sources is the magnetic lattice is designed with a high degree of periodicity. Tracking simulations show that if the periodicity is perturbed (by focusing errors for example), non-linear resonances become excited, which causes a reduction in the dynamic aperture. Therefore it is important to have a method to measure and correct perturbed periodicity. In this paper we study the effect of broken and restored periodicity at an actual third generation light source: the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. First we show that it is possible to accurately determine the storage ring optic and thus the perturbation of the periodicity by fitting measured orbit response matrices. This method allows us to determine individual field gradient errors in quadrupoles and closed orbit errors in sextupoles. By varying individual quadrupole field strengths it is possible to correct the optic, largely restoring the lattice periodicity. A comparison is made of the performance of the ALS before and after the optic is corrected. Measurements of the electron beam tails and the synchrotron light image reveal a large suppression in resonance excitation after the optic is corrected. Correcting the optic also improves the injection efficiency and lifetime.

  10. Building a Generation Knowledge Source using Internet-Accessible Newswire

    CERN Document Server

    Radev, D R; Radev, Dragomir R.; Keown, Kathleen R. Mc

    1997-01-01

    In this paper, we describe a method for automatic creation of a knowledge source for text generation using information extraction over the Internet. We present a prototype system called PROFILE which uses a client-server architecture to extract noun-phrase descriptions of entities such as people, places, and organizations. The system serves two purposes: as an information extraction tool, it allows users to search for textual descriptions of entities; as a utility to generate functional descriptions (FD), it is used in a functional-unification based generation system. We present an evaluation of the approach and its applications to natural language generation and summarization.

  11. Mid-IR fiber optic light source around 6 micron through parametric wavelength translation

    CERN Document Server

    Barh, A; Varshney, R K; Pal, B P; Sanghera, J; Shaw, L B; Aggarwal, I D

    2014-01-01

    We report numerically designed highly nonlinear all glass chalcogenide microstructured optical fiber for efficient generation of light around 6 micron through degenerate four wave mixing by considering continuous wave CO laser of 5 to 10 Watts power emitting at 5.6 micron as the pump. By tuning the pump wavelength, pump power, fiber dispersion and nonlinear properties, narrow and broad band mid-IR all-fiber light source could be realized. Parametric amplification of more than 20 decibel is achievable for the narrow band source at 6.46 micron with a maximum power conversion efficiency of 33 percent while amplification of 22 decibel is achievable for a B-band source over the wavelength range of 5 to 6.3 micron with a conversion efficiency of 40 percent.

  12. Revised accident source terms for light-water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Soffer, L. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-02-01

    This paper presents revised accident source terms for light-water reactors incorporating the severe accident research insights gained in this area over the last 15 years. Current LWR reactor accident source terms used for licensing date from 1962 and are contained in Regulatory Guides 1.3 and 1.4. These specify that 100% of the core inventory of noble gases and 25% of the iodine fission products are assumed to be instantaneously available for release from the containment. The chemical form of the iodine fission products is also assumed to be predominantly elemental iodine. These assumptions have strongly affected present nuclear air cleaning requirements by emphasizing rapid actuation of spray systems and filtration systems optimized to retain elemental iodine. A proposed revision of reactor accident source terms and some im implications for nuclear air cleaning requirements was presented at the 22nd DOE/NRC Nuclear Air Cleaning Conference. A draft report was issued by the NRC for comment in July 1992. Extensive comments were received, with the most significant comments involving (a) release fractions for both volatile and non-volatile species in the early in-vessel release phase, (b) gap release fractions of the noble gases, iodine and cesium, and (c) the timing and duration for the release phases. The final source term report is expected to be issued in late 1994. Although the revised source terms are intended primarily for future plants, current nuclear power plants may request use of revised accident source term insights as well in licensing. This paper emphasizes additional information obtained since the 22nd Conference, including studies on fission product removal mechanisms, results obtained from improved severe accident code calculations and resolution of major comments, and their impact upon the revised accident source terms. Revised accident source terms for both BWRS and PWRS are presented.

  13. An Optically Stabilized Fast-Switching Light Emitting Diode as a Light Source for Functional Neuroimaging

    Science.gov (United States)

    Wagenaar, Daniel A.

    2012-01-01

    Neuroscience research increasingly relies on optical methods for evoking neuronal activity as well as for measuring it, making bright and stable light sources critical building blocks of modern experimental setups. This paper presents a method to control the brightness of a high-power light emitting diode (LED) light source to an unprecedented level of stability. By continuously monitoring the actual light output of the LED with a photodiode and feeding the result back to the LED's driver by way of a proportional-integral controller, drift was reduced to as little as 0.007% per hour over a 12-h period, and short-term fluctuations to 0.005% root-mean-square over 10 seconds. The LED can be switched on and off completely within 100 s, a feature that is crucial when visual stimuli and light for optical recording need to be interleaved to obtain artifact-free recordings. The utility of the system is demonstrated by recording visual responses in the central nervous system of the medicinal leech Hirudo verbana using voltage-sensitive dyes. PMID:22238663

  14. An optically stabilized fast-switching light emitting diode as a light source for functional neuroimaging.

    Directory of Open Access Journals (Sweden)

    Daniel A Wagenaar

    Full Text Available Neuroscience research increasingly relies on optical methods for evoking neuronal activity as well as for measuring it, making bright and stable light sources critical building blocks of modern experimental setups. This paper presents a method to control the brightness of a high-power light emitting diode (LED light source to an unprecedented level of stability. By continuously monitoring the actual light output of the LED with a photodiode and feeding the result back to the LED's driver by way of a proportional-integral controller, drift was reduced to as little as 0.007% per hour over a 12-h period, and short-term fluctuations to 0.005% root-mean-square over 10 seconds. The LED can be switched on and off completely within 100 μs, a feature that is crucial when visual stimuli and light for optical recording need to be interleaved to obtain artifact-free recordings. The utility of the system is demonstrated by recording visual responses in the central nervous system of the medicinal leech Hirudo verbana using voltage-sensitive dyes.

  15. Secret-Key Generation using Correlated Sources and Channels

    CERN Document Server

    Khisti, Ashish; Wornell, Gregory

    2009-01-01

    We study the problem of generating a shared secret key between two terminals in a joint source-channel setup -- the sender communicates to the receiver over a discrete memoryless wiretap channel and additionally the terminals have access to correlated discrete memoryless source sequences. We establish lower and upper bounds on the secret-key capacity. These bounds coincide, establishing the capacity, when the underlying channel consists of independent, parallel and reversely degraded wiretap channels. In the lower bound, the equivocation terms of the source and channel components are functionally additive. The secret-key rate is maximized by optimally balancing the the source and channel contributions. This tradeoff is illustrated in detail for the Gaussian case where it is also shown that Gaussian codebooks achieve the capacity. When the eavesdropper also observes a source sequence, the secret-key capacity is established when the sources and channels of the eavesdropper are a degraded version of the legitima...

  16. Generation of diffuser dot patterns for light guides using fuzzy scheme strategy

    Science.gov (United States)

    Zhao, Heng; Fang, Suping; Yang, Qing; Shang, Bo

    2009-12-01

    We propose a fuzzy scheme strategy for the generation of the diffuser dot patterns in the light guide of an edge-lit backlight. The fuzzy scheme strategy is based on fuzzy logic and rules, which are closely related to the physical luminance properties of the light guide. During the process of generating diffuser dot patterns, two inputs are the dot radius and the distance from dots to a light source, and one output is the luminance of the light guide panel. This strategy converts the linguistic strategy based on expert knowledge the optimal dot-generation strategy. Furthermore, this study includes the discussion of fuzzification and defuzzification strategies, the derivation of fuzzy logic rules, and the analysis of fuzzy reasoning mechanisms. Experiment results reveal that the proposed strategy can achieve an even luminance condition by establishing dot patterns. Compared to conventional methods, the fuzzy scheme strategy has two advantages. It effectively integrates the dot generation scheme into the subsequent optical design phase to make dot patterns more efficient and easy to control. Moreover, optimized dot patterns realize sufficient luminance uniformity.

  17. Energy efficiency and color quality limits in artificial light sources emulating natural illumination.

    Science.gov (United States)

    Hertog, Wim; Llenas, Aleix; Quintero, Jesús M; Hunt, Charles E; Carreras, Josep

    2014-12-15

    We present in this work a calculation of the theoretical limits attainable for natural light emulation with regard to the joint optimization of the Luminous Efficacy of Radiation and color fidelity by using multiple reflectance spectra datasets, along with an implementation of a physical device that approaches these limits. A reduced visible spectrum of blackbody radiators is introduced and demonstrated which allows lamps designed to emulate natural light to operate with excellent color fidelity and higher efficiency as compared to full visible spectrum sources. It is shown that even though 3,000K and 5,500K blackbody sources have maximum efficacies of 21 lm/W and 89 lm/W, respectively, reduced-spectrum artificial light sources can exceed those values up to 363 lm/W and 313 lm/W, respectively, while retaining excellent color fidelity. Experimental demonstration approaching these values is accomplished through the design and implementation of a 12-channel light engine which emits arbitrarily-tunable spectra. The color fidelity of the designed spectra is assessed through Color Rendering Maps, showing that color fidelity is preserved uniformly over a large spectral reflectance dataset, unlike other approaches to generate white light.

  18. Slow-light enhanced correlated photon pair generation in a silicon photonic crystal waveguide.

    Science.gov (United States)

    Xiong, C; Monat, Christelle; Clark, Alex S; Grillet, Christian; Marshall, Graham D; Steel, M J; Li, Juntao; O'Faolain, Liam; Krauss, Thomas F; Rarity, John G; Eggleton, Benjamin J

    2011-09-01

    We report the generation of correlated photon pairs in the telecom C-band at room temperature from a dispersion-engineered silicon photonic crystal waveguide. The spontaneous four-wave mixing process producing the photon pairs is enhanced by slow-light propagation enabling an active device length of less than 100 μm. With a coincidence to accidental ratio of 12.8 at a pair generation rate of 0.006 per pulse, this ultracompact photon pair source paves the way toward scalable quantum information processing realized on-chip.

  19. Slow-light Enhanced Correlated Photon-Pair Generation in Silicon

    CERN Document Server

    Xiong, C; Clark, Alex S; Grillet, Christian; Marshall, Graham D; Steel, M J; Li, Juntao; O'Faolain, Liam; Krauss, Thomas F; Rarity, John G; Eggleton, Benjamin J

    2011-01-01

    We report the generation of correlated photon pairs in the telecom C-band, at room temperature, from a dispersion-engineered silicon photonic crystal waveguide. The spontaneous four-wave mixing process producing the photon pairs is enhanced by slow-light propagation enabling an active device length of less than 100 {\\mu}m. With a coincidence to accidental ratio of 12.8, at a pair generation rate of 0.006 per pulse, this ultra-compact photon pair source is immediately applicable towards scalable quantum information processing realized on-chip.

  20. Rapid generation of light beams carrying orbital angular momentum.

    Science.gov (United States)

    Mirhosseini, Mohammad; Magaña-Loaiza, Omar S; Chen, Changchen; Rodenburg, Brandon; Malik, Mehul; Boyd, Robert W

    2013-12-16

    We report a technique for encoding both amplitude and phase variations onto a laser beam using a single digital micro-mirror device (DMD). Using this technique, we generate Laguerre-Gaussian and vortex orbital-angular-momentum (OAM) modes, along with modes in a set that is mutually unbiased with respect to the OAM basis. Additionally, we have demonstrated rapid switching among the generated modes at a speed of 4 kHz, which is much faster than the speed regularly achieved by phase-only spatial light modulators (SLMs). The dynamic control of both phase and amplitude of a laser beam is an enabling technology for classical communication and quantum key distribution (QKD) systems that employ spatial mode encoding.

  1. Singapore Synchrotron Light Source - Status, first results, program

    CERN Document Server

    Moser, H O; Kempson, V C; Kong, J R; Li, Z W; Nyunt, T; Qian, H J; Rossmanith, R; Tor, P H; Wilhelmi, O; Yang, P; Zheng, H W; Underhay, I J

    2003-01-01

    The Singapore Synchrotron Light Source is a general-purpose synchrotron radiation facility serving research organisations and industry. Beamlines active or coming up within 2002 include lithography for micro/nanofabrication, phase contrast imaging, surface science, and X-ray diffraction and absorption. An infrared spectro/microscopy beamline is expected to become operational in 2003. Further beamlines are under discussion with user groups. The Microtron Undulator Radiation Facility (MURF) is under development to provide brilliant VUV radiation and to prepare for subsequent development of an EUV and X-ray FEL.

  2. The Digital Camera Application in the Taiwan Light Source

    CERN Document Server

    Kuo, C H; Hsu, K T; Hsu, S Y; Hu, K H; Lee, D; Wang, C J; Yang, Y T

    2005-01-01

    Digital camera has been adopted for the booster, storage ring and transport-line diagnostic recently at the Taiwan Light Source. The system provides low image distortion transmission over long distance. The system is integrated with control system. Each screen monitor equip with a digital camera. These screen monitors are used for beam profile measurement and help injection condition optimization. Wider dynamic range and highly flexibility of the digital gated camera provide various functional enhancements. System configuration and present status will be summary in this report.

  3. Future Possibilities of the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Cornacchia, M

    2003-12-02

    A study of the potential for the development of the Linac Coherent Light Source beyond the specifications of the baseline design is presented. These future developments include delivery of x-ray pulses in the one femtosecond regime, extension of the spectral range, increase of the FEL power, exploitation of the spontaneous emission, and a more flexible time structure. As this potential is exploited, the LCLS can maintain its role as a world leading instrument for many years beyond its commissioning in 2008 and initial operation as the world's first x-ray free-electron laser.

  4. The risk of retina damage from high intensity light sources.

    Science.gov (United States)

    Pollak, V A; Romanchuk, K G

    1980-05-01

    The risk of thermal damage to the retina of the eye by exposure to excessive light intensities from continuous and pulsed man-made sources is discussed. The probability of injury increases, the larger the radiant power absorbed by the retina and the smaller the size of the retinal image of the source. A mehtod of estimating the temperature increase of the immediately affected area of the retina is presented. The time constants involved are also briefly considered. Using numerical values from literature for the relevant parameters of the eye, threshold values for a variety of conditions can be established. Below these values little risk of retina damage should exist. The degree of hazard when these values are exceeded depends upon the circumstances. A case study of a welding accident showed good agreement between the conclusions of the theoretical analysis and clinical findings.

  5. Inverse free electron laser accelerator for advanced light sources

    Directory of Open Access Journals (Sweden)

    J. P. Duris

    2012-06-01

    Full Text Available We discuss the inverse free electron laser (IFEL scheme as a compact high gradient accelerator solution for driving advanced light sources such as a soft x-ray free electron laser amplifier or an inverse Compton scattering based gamma-ray source. In particular, we present a series of new developments aimed at improving the design of future IFEL accelerators. These include a new procedure to optimize the choice of the undulator tapering, a new concept for prebunching which greatly improves the fraction of trapped particles and the final energy spread, and a self-consistent study of beam loading effects which leads to an energy-efficient high laser-to-beam power conversion.

  6. Polydopamine Generates Hydroxyl Free Radicals under Ultraviolet-Light Illumination.

    Science.gov (United States)

    Wang, Zehuan; Tang, Feng; Fan, Hailong; Wang, Le; Jin, Zhaoxia

    2017-06-13

    Polydopamine (PDA) generally demonstrates as an efficient free-radical scavenger. However, its free-radical chemistry under illumination is unclear, which becomes important in view of growing studies of polydopamine applications in photoprotector and photothermal therapy. In this study, for the first time, we reported an experimental investigation of the generation of hydroxyl free radicals from ultraviolet (UV)-illuminated polydopamine in an aqueous environment. By using terephthalic acid as fluorescent probe, we measured hydroxyl radicals generated from UV-illuminated polydopamine with different shapes and sizes. The morphology of PDA shows significant influence on its productions of hydroxyl free radicals. Through characterizations of UV-vis absorption spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectrometry, mass spectrometry, and thermogravimetric analysis, we demonstrated the change of PDA nanomaterials brought by UV-light illumination in composition and thermal stability. We proposed a tentative mechanism for interpreting the relationship between morphology and photostability of PDA nanomaterials. These results reveal underlying complexity of polydopamine chemistry under light illumination that will deepen our understanding and benefit its further application.

  7. Composite-Light-Source Interferometer for Real-Time Micro-Vibration Measurements

    Institute of Scientific and Technical Information of China (English)

    Dailin Li; Xiangzhao Wang

    2003-01-01

    A novel interferometer using a composite light source for real time measurements of micro-vibrations is proposed.The experimental results make it clear that it is insensitive to external disturbances and intensity fluctuations of the source light.

  8. Composite-Light-Source Interferometer for Real-Time Micro-Vibration Measurements

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel interferometer using a composite light source for real time measurements of micro-vibrations is proposed. The experimental results make it clear that it is insensitive to external disturbances and intensity fluctuations of the source light.

  9. Supercontinuum Light Sources for Hyperspectral Subsurface Laser Scattering

    DEFF Research Database (Denmark)

    Nielsen, Otto Højager Attermann; Dahl, Anders Lindbjerg; Larsen, Rasmus;

    2011-01-01

    A materials structural and chemical composition influences its optical scattering properties. In this paper we investigate the use of subsurface laser scattering (SLS) for inferring structural and chemical information of food products. We have constructed a computer vision system based on a super......A materials structural and chemical composition influences its optical scattering properties. In this paper we investigate the use of subsurface laser scattering (SLS) for inferring structural and chemical information of food products. We have constructed a computer vision system based...... on a supercontinuum laser light source and an Acousto- Optic Tunable Filter (AOTF) to provide a collimated light source, which can be tuned to any wavelength in the range from 480 to 900 nm. We present the newly developed hyperspectral vision system together with a proof-of-principle study of its ability...... to discriminate between dairy products with either similar chemical or structural composition. The combined vision system is a new way for industrial food inspection allowing non-intrusive online process inspection of parameters that is hard with existing technology....

  10. Hydrogen Plasma Generation with 200 MHz RF Ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeongtae; Park, Kwangmook; Seo, Dong Hyuk; Kim, Han-Sung; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The ion source for the system is required to be rugged with 2000 hours maintenance free operation time because it is installed in the vessel filled with SF6 gas at the pressure of 10 bar. A 200 MHz RF ion source is considered as an ion source. It is a simple construction and provides long life operation. The specifications of the ion source are 5 kV extraction voltage and 1 mA beam current referenced to the proton. RF ion source has been developed and undergone a performance test. Results of the test are presented. 200 MHz RF ion source is designated and manufactured. First of all test stand test of ion source are set up for a performance test of ion source. It includes a RF ion source, a 200-MHz RF system, beam extraction system, vacuum system, beam extraction system, and beam diagnostic system. At pressure of 1.2E-5 torr, hydrogen plasma is generated with net RF power 70 W. Pyrex tube surrounded by an inductive coil takes the role of vessel and discharge is enhanced with field of permanent magnets.

  11. Pulsed squeezed-light generation in a waveguide with second-subharmonic generation and periodic corrugation

    CERN Document Server

    Perina, Jan

    2013-01-01

    Quantum pulsed second-subharmonic generation in a planar waveguide with a small periodic corrugation at the surface is studied. Back-scattering of the interacting fields on the corrugation enhances the nonlinear interaction giving larger values of squeezing. The problem of back-scattering is treated by perturbation theory, using the Fourier transform for non-dispersion propagation, and by numerical approach in the general case. Optimum spectral modes for squeezed-light generation are found using the Bloch-Messiah reduction. Improvement in squeezing and increase of numbers of generated photons are quantified for the corrugation resonating with the fundamental and second-subharmonic field. Splitting of the generated pulse by the corrugation is predicted.

  12. Two Sources of Control over the Generation of Software Instructions

    CERN Document Server

    Hartley, A; Hartley, Anthony; Paris, Cecile

    1996-01-01

    This paper presents an analysis conducted on a corpus of software instructions in French in order to establish whether task structure elements (the procedural representation of the users' tasks) are alone sufficient to control the grammatical resources of a text generator. We show that the construct of genre provides a useful additional source of control enabling us to resolve undetermined cases.

  13. Experimental generation of ring-shaped beams with random sources

    CERN Document Server

    Reddy, Salla Gangi; Prabhakar, Shashi; Singh, R P

    2013-01-01

    We have experimentally reproduced ring shaped beams from the scattered Laguerre-Gaussian and Bessel- Gaussian beams. A rotating ground glass plate is used as a scattering medium and a plano convex lens collects the scattered light to generate ring shaped beams at the Fourier plane. The experimental results are in good agreement with the theoretical results of Mei and Korotkova (Opt. Lett. 38, 91{93 (2013)).

  14. Red and Blue Light Generation in an LiTaO3 Crystal with a Double Grating Domain Structure

    Institute of Scientific and Technical Information of China (English)

    LIU Zhao-Wei; ZHU Shi-Ning; ZHU Yong-Yuan; WANG Hui-Tian; LUO Guo-Zhen; LIU Hui; MIN Nai-Ben; LIANG Xiao-Yan; XU Zu-Yan

    2001-01-01

    Simultaneous red and blue light generation in an LiTaOs crystal with a double grating structure is reported for the first time. The double grating consists of two separate domain reversal sequences (superlattices) in seriesand is fabricated by the field poling technique at room temperature. Using a picosecond 532 nm laser as a pump source, the red light at 631 nm and blue light at 460nm are generated at the same time. A possible applicationof the superlattice crystal is presented. X

  15. The Physical Basis of Lg Generation by Explosion Sources

    Energy Technology Data Exchange (ETDEWEB)

    J. L. Stevens; G. E. Baker; H. Xu; T. J. Bennett; N. Rimer; S. D. Day

    2004-12-20

    The goal of this project has been to develop a quantitative predictive capability for explosion-generated Lg phases with a sound and unambiguous physical basis. The research program consisted of a theoretical investigation of explosion-generated Lg combined with an observational study. The specific question addressed by this research program is how the Lg phase is generated by underground nuclear explosions. This question is fundamental to how Lg phases are interpreted for use in explosion yield estimation and earthquake/explosion discrimination. To constrain modeling, we have extensively reviewed the existing literature and complemented that work with an examination of several explosion data sets, most notably: (1) Degelen Mountain explosions recorded between 7 and 57 km, with corresponding recordings at Borovoye, at approximately 650 km; (2) recordings from Russian deep seismic sounding experiments; (3) NTS explosion sources including the NPE and nuclear tests covering a range of source depths and media properties. A simple point explosion in an infinite medium generates no shear waves, so the Lg phase is generated entirely by non-spherical components of the source and conversions through reflections and scattering. We find that the most important contributors to the Lg phase are: (1) P to S conversion at the free surface and other near source interfaces, (2) S waves generated directly by a realistically distributed explosion source including nonlinear effects due to the free surface and gravity, and (3) Rg scattering to Lg. Additional effects that contribute significantly to Lg are scattering of converted S phases that traps more of the converted P-to-S in the crust, and randomization of the components of Lg. The pS phase from a spherically symmetric explosion source in media with P-wave velocity less than upper mantle S-wave velocity is trapped in the crust and can explain the observed radial and vertical Lg. The free surface pS converted phase from the same

  16. Spectrum synthesis for a spectrally tunable light source based on a DMD-convex grating Offner configuration

    Science.gov (United States)

    Ma, Suodong; Pan, Qiao; Shen, Weimin

    2016-09-01

    As one kind of light source simulation devices, spectrally tunable light sources are able to generate specific spectral shape and radiant intensity outputs according to different application requirements, which have urgent demands in many fields of the national economy and the national defense industry. Compared with the LED-type spectrally tunable light source, the one based on a DMD-convex grating Offner configuration has advantages of high spectral resolution, strong digital controllability, high spectrum synthesis accuracy, etc. As a key link of the above type light source to achieve target spectrum outputs, spectrum synthesis algorithm based on spectrum matching is therefore very important. An improved spectrum synthesis algorithm based on linear least square initialization and Levenberg-Marquardt iterative optimization is proposed in this paper on the basis of in-depth study of the spectrum matching principle. The effectiveness of the proposed method is verified by a series of simulations and experimental works.

  17. Real-time tunability of chip-based light source enabled by microfluidic mixing

    DEFF Research Database (Denmark)

    Olsen, Brian Bilenberg; Rasmussen, Torben; Balslev, Søren

    2006-01-01

    We demonstrate real-time tunability of a chip-based liquid light source enabled by microfluidic mixing. The mixer and light source are fabricated in SU-8 which is suitable for integration in SU-8-based laboratory-on-a-chip microsystems. The tunability of the light source is achieved by changing...

  18. EDITORIAL: Special Issue on advanced and emerging light sources Special Issue on advanced and emerging light sources

    Science.gov (United States)

    Haverlag, Marco; Kroesen, Gerrit; Ferguson, Ian

    2011-06-01

    The papers in this special issue of Journal of Physics D: Applied Physics (JPhysD) originate from the 12th International Symposium on the Science and Technology of Light Sources and the 3rd International Conference on White LEDs and Solid State Lighting, held 11-16 July 2010 at Eindhoven University. Abstracts of all papers presented at this combined conference were published in the Conference Proceedings LS-WLED 2010 by FAST-LS, edited by M Haverlag, G M W Kroesen and T Taguchi. Special issues of the previous three LS conferences have been well-cited and have proven to be an important source of information for the lighting community. The 2010 LS-Symposium was a combined conference with the White LED Conference in order to enhance the scope of this conference series towards new light source technologies such as LEDs and OLEDs, and this co-operation will be continued in the future. Given the faster technology development in these areas it was also decided to shorten the interval between conferences from three to two years. Well over 200 invited presentations, landmark presentations and poster contributions were presented at the 2010 LS-Symposium. The organizing committee have selected from these a number of outstanding contributions with a high technological content and invited the authors to submit a full paper in JPhysD. The criteria were that the work should not be a repetition of the work already published in the Proceedings, but should be new, complete, within the scope of JPhysD, and meeting the normal quality standards of this journal. After peer review a combined set of 18 papers is published in this JPhysD special issue. In addition, a number of lighting-application-orientated papers will be published in a special issue of Journal of Light & Visual Environment later in 2011. The papers in this special issue of JPhysD show that research in the science and technology of light sources still covers a broad set of subject areas which includes both 'classical

  19. Synchronized ion acceleration by ultraintense slow light and electron source for x-ray production from low-density targets

    Science.gov (United States)

    Brantov, A. V.; Bychenkov, V. Yu

    2017-03-01

    Synchronized proton acceleration by ultraintense slow light in a low-density target Brantov et al (2016 Phys. Rev. Lett. 116 085004) is studied for a circularly polarized laser pulse. This study demonstrates the advantage of circularly polarized light compared with linearly polarized light used for high-energy proton generation. At the same time, high-energy electron production for gamma-ray generation is not sensitive to the polarization of the laser pulse. Both the proton and the electron sources are considered in application to petawatt-class lasers.

  20. Single 100-terawatt attosecond X-ray light pulse generation

    CERN Document Server

    Xu, X R; Zhang, Y X; Lu, H Y; Zhang, H; Dromey, B; Zhu, S P; Zhou, C T; Zepf, M; He, X T

    2016-01-01

    The birth of attosecond light sources is expected to inspire a breakthrough in ultrafast optics, which may extend human real-time measurement and control techniques into atomic-scale electronic dynamics. For applications, it is essential to obtain a single attosecond pulse of high intensity, large photon energy and short duration. Here we show that single 100-terawatt attosecond X-ray light pulse with intensity ${1\\times10^{21}}\\textrm{W}/\\textrm{cm}^{{ 2}}$ and duration ${7.9} \\textrm{as}$ can be produced by intense laser irradiation on a capacitor-nanofoil target composed of two separate nanofoils. In the interaction, a strong electrostatic potential develops between two nanofoils, which drags electrons out of the second foil and piles them up in vacuum, forming an ultradense relativistic electron nanobunch. This nanobunch exists in only half a laser cycle and smears out in others, resulting in coherent synchrotron emission of a single pulse. Such an unprecedentedly giant attosecond X-ray pulse may bring us...

  1. Characterization of germanium linear kinoform lenses at Diamond Light Source.

    Science.gov (United States)

    Alianelli, L; Sawhney, K J S; Tiwari, M K; Dolbnya, I P; Stevens, R; Jenkins, D W K; Loader, I M; Wilson, M C; Malik, A

    2009-05-01

    The unprecedented brilliance achieved by third-generation synchrotron sources and the availability of improved optics have opened up new opportunities for the study of materials at the micrometre and nanometre scale. Focusing the synchrotron radiation to smaller and smaller beams is having a huge impact on a wide research area at synchrotrons. The key to the exploitation of the improved sources is the development of novel optics that deliver narrow beams without loss of brilliance and coherence. Several types of synchrotron focusing optics are successfully fabricated using advanced miniaturization techniques. Kinoform refractive lenses are being developed for hard X-ray beamlines, and the first test results at Diamond are discussed in this paper.

  2. State of Art in the Science and Technology of Electrical Discharge Light Sources

    Science.gov (United States)

    Zissis, Georges; Rouffet, Jean-Baptiste

    Light is vital for life: Light sources play an indispensable role to daily life of any Human being. Our World cannot be conceived without light. Quality of life, health and, somehow, urban security related with traffic and crime prevention measures depend on light and on its quality. The lighting industry is an important economic factor in Europe, USA and many Asiatic Countries. All in all, lighting is an important socio-economic factor and lighting system development should be an integral part of any Sustainable Development and of any program of improvement of Quality of Life. This presentation provides an overview of the present state of research in the science and technology of light sources. Existing technologies and future challenges for the lighting industry will be presented. To better understanding the light source technology an part of this presentation will be devoted to the physics of light sources.

  3. Light-assisted drying (LAD) of small volume biologics: a comparison of two IR light sources

    Science.gov (United States)

    Young, Madison A.; Van Vorst, Matthew; Elliott, Gloria D.; Trammell, Susan R.

    2016-03-01

    Protein therapeutics have been developed to treat diseases ranging from arthritis and psoriasis to cancer. A challenge in the development of protein-based drugs is maintaining the protein in the folded state during processing and storage. We are developing a novel processing method, light-assisted drying (LAD), to dehydrate proteins suspended in a sugar (trehalose) solution for storage at supra-zero temperatures. Our technique selectively heats the water in small volume samples using near-IR light to speed dehydration which prevents sugar crystallization that can damage embedded proteins. In this study, we compare the end moisture content (EMC) as a function of processing time of samples dried with two different light sources, Nd:YAG (1064 nm) and Thulium fiber (1850 nm) lasers. EMC is the ratio of water to dry weight in a sample and the lower the EMC the higher the possible storage temperature. LAD with the 1064 and 1850 nm lasers yielded 78% and 65% lower EMC, respectively, than standard air-drying. After 40 minutes of LAD with 1064 and 1850 nm sources, EMCs of 0.27+/-.27 and 0.15+/-.05 gH2O/gDryWeight were reached, which are near the desired value of 0.10 gH2O/gDryWeight that enables storage in a glassy state without refrigeration. LAD is a promising new technique for the preparation of biologics for anhydrous preservation.

  4. Light third-generation squarks from flavour gauge messengers

    Energy Technology Data Exchange (ETDEWEB)

    Bruemmer, Felix [International School for Advanced Studies, Trieste (Italy); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); McGarrie, Moritz [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Univ. of the Witwatersrand, Johannesburg (South Africa). School of Physics and Centre for Theoretical Physics; Weiler, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); CERN - European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.

    2014-04-15

    We study models of gauge-mediated supersymmetry breaking with a gauged horizontal SU(3){sub F} symmetry acting on the quark superfields. If SU(3){sub F} is broken non-supersymmetrically by F-term vacuum expectation values, the massive gauge bosons and gauginos become messengers for SUSY breaking mediation. These gauge messenger fields induce a flavour-dependent, negative contribution to the soft masses of the squarks at one loop. In combination with the soft terms from standard gauge mediation, one obtains large and degenerate first- and second-generation squark masses, while the stops and sbottoms are light. We discuss the implications of this mechanism for the superparticle spectrum and for flavour precision observables. We also provide an explicit realization in a model with simultaneous SUSY and SU(3){sub F} breaking.

  5. Light third-generation squarks from flavour gauge messengers

    Energy Technology Data Exchange (ETDEWEB)

    Brümmer, Felix [SISSA/ISAS,Via Bonomea 265, Trieste I-34136 (Italy); Deutsches Elektronen-Synchrotron DESY,Notkestrasse 85, D-22607 Hamburg (Germany); McGarrie, Moritz [Deutsches Elektronen-Synchrotron DESY,Notkestrasse 85, D-22607 Hamburg (Germany); National Institute for Theoretical Physics, School of Physics,and Centre for Theoretical Physics, University of the Witwatersrand,Johannesburg, WITS 2050 (South Africa); Weiler, Andreas [Deutsches Elektronen-Synchrotron DESY,Notkestrasse 85, D-22607 Hamburg (Germany); CERN Theory Division,CH-1211 Geneva 23 (Switzerland)

    2014-04-10

    We study models of gauge-mediated supersymmetry breaking with a gauged horizontal SU(3){sub F} symmetry acting on the quark superfields. If SU(3){sub F} is broken non-supersymmetrically by F-term vacuum expectation values, the massive gauge bosons and gauginos become messengers for SUSY breaking mediation. These gauge messenger fields induce a flavour-dependent, negative contribution to the soft masses of the squarks at one loop. In combination with the soft terms from standard gauge mediation, one obtains large and degenerate first- and second-generation squark masses, while the stops and sbottoms are light. We discuss the implications of this mechanism for the superparticle spectrum and for flavour precision observables. We also provide an explicit realization in a model with simultaneous SUSY and SU(3){sub F} breaking.

  6. Surface plasma source with saddle antenna radio frequency plasma generator.

    Science.gov (United States)

    Dudnikov, V; Johnson, R P; Murray, S; Pennisi, T; Piller, C; Santana, M; Stockli, M; Welton, R

    2012-02-01

    A prototype RF H(-) surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA∕kW. Control experiments with H(-) beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

  7. Toward the Automated Generation of Components from Existing Source Code

    Energy Technology Data Exchange (ETDEWEB)

    Quinlan, D; Yi, Q; Kumfert, G; Epperly, T; Dahlgren, T; Schordan, M; White, B

    2004-12-02

    A major challenge to achieving widespread use of software component technology in scientific computing is an effective migration strategy for existing, or legacy, source code. This paper describes initial work and challenges in automating the identification and generation of components using the ROSE compiler infrastructure and the Babel language interoperability tool. Babel enables calling interfaces expressed in the Scientific Interface Definition Language (SIDL) to be implemented in, and called from, an arbitrary combination of supported languages. ROSE is used to build specialized source-to-source translators that (1) extract a SIDL interface specification from information implicit in existing C++ source code and (2) transform Babel's output to include dispatches to the legacy code.

  8. Planar light bullets under conditions of second-harmonic generation

    Science.gov (United States)

    Sazonov, Sergey V.; Mamaikin, Mikhail S.; Komissarova, Maria V.; Zakharova, Irina G.

    2017-08-01

    We study solutions to second-harmonic-generation equations in two-dimensional media with anomalous dispersion. The analytical solution is obtained in an approximate form of the planar spatiotemporal two-component soliton by means of the averaged Lagrangian method. It is shown that a decrease in the amplitudes of both soliton components and an increase in the value of the transverse coordinate are accompanied by an increase in their temporal duration. Within this variational approach, we have managed to find a stability criterion for the light bullet and a period of oscillations of soliton parameters. Then, we use the obtained form as an initial configuration to carry out the direct numerical simulation of soliton dynamics. We demonstrate stable propagation of spatiotemporal solitons undergoing small oscillations predicted analytically for a long distance. The formation of a two-component light bullet is shown when we launch a pulse only at the fundamental frequency. In addition, we investigate the phase and group-velocity mismatch effects on the propagation of pulses.

  9. CITIUS: an IR-XUV light source for fundamental and applied ultrafast science

    CERN Document Server

    Grazioli, C; Ciavardini, A; Coreno, M; Frassetto, F; Gauthier, D; Golob, D; Ivanov, R; Kivimäki, A; Mahieu, B; Bucar, Bojan; Merhar, M; Miotti, P; Poletto, L; Polo, E; Ressel, B; Spezzani, C; De Ninno, G

    2013-01-01

    We present the main features of CITIUS, a new light source for ultrafast science, generating tunable, intense, femtosecond pulses in the spectral range from IR to XUV. The XUV pulses (about 10^5-10^8 photons/pulse in the range 14-80 eV) are produced by laser-induced high-order harmonic generation in gas. This radiation is monochromatized by a time-preserving monochromator, allowing also to work with high-resolution bandwidth selection. The tunable IR-UV pulses (10^{12}-10^{15} photons/pulse in the range 0.4-5.6 eV) are generated by an optical parametric amplifier, which is driven by a fraction of the same laser pulse that generates high order harmonics. The IR-UV and XUV pulses follow different optical paths and are eventually recombined on the sample for pump-probe experiments. The new light source will become the fulcrum of a new center located at the University of Nova Gorica, active in a wide range of scientific fields, including materials science, catalysis, biochemistry and magnetism. We also present th...

  10. Fundamental Scaling of Microplasmas and Tunable UV Light Generation.

    Energy Technology Data Exchange (ETDEWEB)

    Manginell, Ronald P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sillerud, Colin Halliday [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hopkins, Matthew M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yee, Benjamin Tong [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moorman, Matthew W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schwindt, Peter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Anderson, John Moses [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pfeifer, Nathaniel Bryant [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-11-01

    The temporal evolution of spectral lines from microplasma devices (MD) was studied, including impurity transitions. Long-wavelength emission diminishes more rapidly than deep UV with decreasing pulse width and RF operation. Thus, switching from DC to short pulsed or RF operation, UV emissions can be suppressed, allowing for real-time tuning of the ionization energy of a microplasma photo-ionization source, which is useful for chemical and atomic physics. Scaling allows MD to operate near atmospheric pressure where excimer states are efficiently created and emit down to 65 nm; laser emissions fall off below 200 nm, making MD light sources attractive for deep UV use. A first fully-kinetic three-dimensional model was developed that explicitly calculates electron-energy distribution function. This, and non-continuum effects, were studied with the model and how they are impacted by geometry and transient or DC operation. Finally, a global non-dimensional model was developed to help explain general trends MD physics.

  11. Highlights from e-EPS: Coordinated Access to Light sources

    CERN Multimedia

    e-EPS News

    2014-01-01

    The CALIPSO project, which runs until May 2015, will contribute to the effective exploitation of European synchrotrons and free electron lasers. CALIPSO (Coordinated Access to Light sources to Promote Standards and Optimisation) includes 20 partners forming one of the largest Research Networks in the world.   e-EPS interviewed M. Bertolo, CALIPSO project manager and his assistant C. Blasetti. Which challenges are addressed by CALIPSO? CALIPSO’s goal is to optimize the exploitation of the European synchrotrons and Free Electron Lasers. With respect to previous projects funded by the European Commission, it foresees significant improvements in integration, innovation and user-friendliness in all three areas of networking, transnational access and instrumentation. The Transnational Access program potentially benefits a community of 25,000 estimated users offering free open access to 12 synchrotrons and 5 free electron lasers solely based on scientific merit. In ad...

  12. Semiconductor light source with electrically tunable emission wavelength

    Energy Technology Data Exchange (ETDEWEB)

    Belenky, Gregory (Port Jefferson, NY); Bruno, John D. (Bowie, MD); Kisin, Mikhail V. (Centereach, NY); Luryi, Serge (Setauket, NY); Shterengas, Leon (Centereach, NY); Suchalkin, Sergey (Centereach, NY); Tober, Richard L. (Elkridge, MD)

    2011-01-25

    A semiconductor light source comprises a substrate, lower and upper claddings, a waveguide region with imbedded active area, and electrical contacts to provide voltage necessary for the wavelength tuning. The active region includes single or several heterojunction periods sandwiched between charge accumulation layers. Each of the active region periods comprises higher and lower affinity semiconductor layers with type-II band alignment. The charge carrier accumulation in the charge accumulation layers results in electric field build-up and leads to the formation of generally triangular electron and hole potential wells in the higher and lower affinity layers. Nonequillibrium carriers can be created in the active region by means of electrical injection or optical pumping. The ground state energy in the triangular wells and the radiation wavelength can be tuned by changing the voltage drop across the active region.

  13. Workshop on scientific applications of short wavelength coherent light sources

    Energy Technology Data Exchange (ETDEWEB)

    Spicer, W.; Arthur, J.; Winick, H.

    1993-02-01

    This report contains paper on the following topics: A 2 to 4nm High Power FEL On the SLAC Linac; Atomic Physics with an X-ray Laser; High Resolution, Three Dimensional Soft X-ray Imaging; The Role of X-ray Induced Damage in Biological Micro-imaging; Prospects for X-ray Microscopy in Biology; Femtosecond Optical Pulses ; Research in Chemical Physics Surface Science, and Materials Science, with a Linear Accelerator Coherent Light Source; Application of 10 GeV Electron Driven X-ray Laser in Gamma-ray Laser Research; Non-Linear Optics, Fluorescence, Spectromicroscopy, Stimulated Desorption: We Need LCLS' Brightness and Time Scale; Application of High Intensity X-rays to Materials Synthesis and Processing; LCLS Optics: Selected Technological Issues and Scientific Opportunities; Possible Applications of an FEL for Materials Studies in the 60 eV to 200 eV Spectral Region.

  14. Workshop on scientific applications of short wavelength coherent light sources

    Energy Technology Data Exchange (ETDEWEB)

    Spicer, W.; Arthur, J.; Winick, H.

    1993-02-01

    This report contains paper on the following topics: A 2 to 4nm High Power FEL On the SLAC Linac; Atomic Physics with an X-ray Laser; High Resolution, Three Dimensional Soft X-ray Imaging; The Role of X-ray Induced Damage in Biological Micro-imaging; Prospects for X-ray Microscopy in Biology; Femtosecond Optical Pulses?; Research in Chemical Physics Surface Science, and Materials Science, with a Linear Accelerator Coherent Light Source; Application of 10 GeV Electron Driven X-ray Laser in Gamma-ray Laser Research; Non-Linear Optics, Fluorescence, Spectromicroscopy, Stimulated Desorption: We Need LCLS` Brightness and Time Scale; Application of High Intensity X-rays to Materials Synthesis and Processing; LCLS Optics: Selected Technological Issues and Scientific Opportunities; Possible Applications of an FEL for Materials Studies in the 60 eV to 200 eV Spectral Region.

  15. Neon reduction program on Cymer ArF light sources

    Science.gov (United States)

    Kanawade, Dinesh; Roman, Yzzer; Cacouris, Ted; Thornes, Josh; O'Brien, Kevin

    2016-03-01

    In response to significant neon supply constraints, Cymer has responded with a multi-part plan to support its customers. Cymer's primary objective is to ensure that reliable system performance is maintained while minimizing gas consumption. Gas algorithms were optimized to ensure stable performance across all operating conditions. The Cymer neon support plan contains four elements: 1. Gas reduction program to reduce neon by >50% while maintaining existing performance levels and availability; 2. short-term containment solutions for immediate relief. 3. qualification of additional gas suppliers; and 4. long-term recycling/reclaim opportunity. The Cymer neon reduction program has shown excellent results as demonstrated through the comparison on standard gas use versus the new >50% reduced neon performance for ArF immersion light sources. Testing included stressful conditions such as repetition rate, duty cycle and energy target changes. No performance degradation has been observed over typical gas lives.

  16. NATIONAL SYNCHROTRON LIGHT SOURCE MEDICAL PERSONNEL PROTECTION INTERLOCK

    Energy Technology Data Exchange (ETDEWEB)

    BUDA,S.; GMUR,N.F.; LARSON,R.; THOMLINSON,W.

    1998-11-03

    This report is founded on reports written in April 1987 by Robert Hettel for angiography operations at the Stanford Synchrotron Research Laboratory (SSRL) and a subsequent report covering angiography operations at the National Synchrotron Light Source (NSLS); BNL Informal Report 47681, June 1992. The latter report has now been rewritten in order to accurately reflect the design and installation of a new medical safety system at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). Known originally as the Angiography Personnel Protection Interlock (APPI), this system has been modified to incorporate other medical imaging research programs on the same beamline and thus the name has been changed to the more generic Medical Personnel Protection Interlock (MPPI). This report will deal almost exclusively with the human imaging (angiography, bronchography, mammography) aspects of the safety system, but will briefly explain the modular aspects of the system allowing other medical experiments to be incorporated.

  17. Pixel detector system development at Diamond Light Source

    Science.gov (United States)

    Marchal, J.; Horswell, I.; Gimenez, E. N.; Tartoni, N.

    2010-10-01

    Hybrid pixel detectors consisting of an array of silicon photodiodes bump-bonded to CMOS read-out chips provide high signal-to-noise ratio and high dynamic range compared to CCD-based detectors and Image Plates. These detector features are important for SAXS experiments where a wide range of intensities are present in the images. For time resolved SAXS experiments, high frame rates are compulsory. The latest CMOS read-out chip developed by the MEDIPIX collaboration provides high frame rate and continuous acquisition mode. A read-out system for an array of MEDIPIX3 sensors is under development at Diamond Light Source. This system will support a full resolution frame rate of 1 kHz at a pixel counter depth of 12-bit and a frame rate of 30 kHz at a counter depth of 1 bit. Details concerning system design and MEDIPIX sensors characterization are presented.

  18. VCSELs as light source for time-of-flight sensors

    Science.gov (United States)

    Moench, Holger; Frey, Manuel; Grabherr, Martin; Gronenborn, Stephan; Gudde, Ralph; Kolb, Johanna; Miller, Michael; Weigl, Alexander

    2017-02-01

    VCSELs and VCSEL arrays are an ideal light source for time-of-flight based sensors. The narrow emission spectrum and the ability for short pulses make them superior to LEDs. Combined with fast photodiodes or special camera chips spatial 3D information can be obtained which is needed in diverse applications like camera autofocus, indoor navigation, 3Dobject recognition or even autonomously driving vehicles. VCSEL arrays are the way to tailor the output power. For pulse operation at low duty cycle average heat dissipation is no longer the upper limit to the operating point of VCSELs but over-pulsing becomes possible. Taking into account electrical boundary conditions and optimum conversion efficiency arrays can be designed for specific operating conditions. Measurements of arrays under short pulse operation are presented using a package with integrated driver.

  19. Observation of nonlinear resonances in the advanced light source

    Science.gov (United States)

    Robin, D.; Collins, H.; Decking, W.; Portmann, G.; Schachinger, L.; Zholents, A.

    1995-09-01

    Observations of nonlinear resonances in the Advanced Light Source have been made by scanning betatron tunes and observing count rates in a beam-loss radiation monitor placed down stream of a beam scraper. We have found that it is possible to see structural resonances which are unallowed as well as those which are allowed by the ring's natural 12-fold symmetry. By systematically breaking the amount of symmetry we see that the widths of the unallowed resonances grow while the widths of the allowed resonances do not. In this paper we briefly discuss the importance of symmetry and its effect on resonances in the design of the ALS. Next we describe our experimental setup and discuss the performance of the beam loss monitor which we used to view the resonances. We then present scans of the tune space where one can see the presence of the structural resonances and their evolution when the lattice symmetry is systematically broken.

  20. Open Source Next Generation Visualization Software for Interplanetary Missions

    Science.gov (United States)

    Trimble, Jay; Rinker, George

    2016-01-01

    Mission control is evolving quickly, driven by the requirements of new missions, and enabled by modern computing capabilities. Distributed operations, access to data anywhere, data visualization for spacecraft analysis that spans multiple data sources, flexible reconfiguration to support multiple missions, and operator use cases, are driving the need for new capabilities. NASA's Advanced Multi-Mission Operations System (AMMOS), Ames Research Center (ARC) and the Jet Propulsion Laboratory (JPL) are collaborating to build a new generation of mission operations software for visualization, to enable mission control anywhere, on the desktop, tablet and phone. The software is built on an open source platform that is open for contributions (http://nasa.github.io/openmct).

  1. Imaging spectroscopic analysis at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    MacDowell, A. A.; Warwick, T.; Anders, S.; Lamble, G.M.; Martin, M.C.; McKinney, W.R.; Padmore, H.A.

    1999-05-12

    One of the major advances at the high brightness third generation synchrotrons is the dramatic improvement of imaging capability. There is a large multi-disciplinary effort underway at the ALS to develop imaging X-ray, UV and Infra-red spectroscopic analysis on a spatial scale from. a few microns to 10nm. These developments make use of light that varies in energy from 6meV to 15KeV. Imaging and spectroscopy are finding applications in surface science, bulk materials analysis, semiconductor structures, particulate contaminants, magnetic thin films, biology and environmental science. This article is an overview and status report from the developers of some of these techniques at the ALS. The following table lists all the currently available microscopes at the. ALS. This article will describe some of the microscopes and some of the early applications.

  2. A Novel Method of Utilizing Hybrid Generator as Renewable Source

    Directory of Open Access Journals (Sweden)

    K.Fathima

    2015-12-01

    Full Text Available Energy production and consumption in the future may depend on renewable energy sources and also depends on the efficiency of utilizing it. Here, a hybrid system, a combination of solar cells and thermoelectric generators is controlled by open circuit voltage method which is normally used for linear electrical characteristics. The proposed system is supported by theoretical analysis and simulation. Lead acid battery is used to accumulate the harvested energy. Cuk converters are used here to improve the efficiency and helps in reduction of noises. Hybrid generators are found to be efficient and more stable.

  3. Light absorption properties of laboratory generated tar ball particles

    Directory of Open Access Journals (Sweden)

    A. Hoffer

    2015-06-01

    Full Text Available Tar balls (TBs are a specific particle type which is abundant in the global troposphere, in particular in biomass smoke plumes. These particles belong to the family of atmospheric brown carbon (BrC which can absorb light in the visible range of the solar spectrum. Albeit TBs are typically present as individual particles in biomass smoke plumes, their absorption properties have been only indirectly inferred from field observations or calculations based on their electron energy-loss spectra. This is because in biomass smoke TBs coexist with various other particle types (e.g. organic particles with inorganic inclusions and soot, the latter is emitted mainly during flaming conditions from which they cannot be physically separated; thus, a direct experimental determination of their absorption properties is not feasible. Very recently we have demonstrated that TBs can be generated in the laboratory from droplets of wood tar that resemble atmospheric TBs in all of their observed properties. As a follow-up study we have installed on-line instruments to our laboratory set-up generating pure TB particles to measure the absorption and scattering, as well as size distribution of the particles. In addition, samples were collected for transmission electron microscopy (TEM and total carbon (TC analysis. The effects of experimental parameters were also studied. The mass absorption coefficients of the laboratory generated TBs were found to be in the range of 0.8–3.0 m2 g−1 at 550 nm, with absorption Ångström exponents (AAE between 2.7 and 3.4 (average 2.9 in the wavelength range 467–652 nm. The refractive index of TBs as derived from Mie calculations was about 1.84–0.21i at 550 nm. In the brown carbon continuum these values fall closer to those of soot than to other light-absorbing species such as humic-like substances (HULIS. Considering the abundance of TBs in biomass smoke and the global magnitude of biomass burning emissions, these findings may

  4. Status of PEP-X Light Source Design Study

    Energy Technology Data Exchange (ETDEWEB)

    Bane, K.L.F.; Bertsche, K.J.; Cai, Y.; Chao, A.; Huang, X.; Jiao, Y.; Ng, C.-K.; Nosochkov, Y.; Novokhatski, A.; Rivetta, C.H.; Safranek, J.A.; Stupakov, G.V.; Wang, L.; Wang, M.-H.; Xiao, L.; /SLAC; Hettel, R.O.; /SLAC; Rabedeau, T.; /SLAC

    2011-12-14

    The SLAC Beam Physics group and other SLAC collaborators continue to study options for implementing a near diffraction-limited ring-based light source in the 2.2-km PEP-II tunnel that will serve the SSRL scientific program in the future. The study team has completed the baseline design for a 4.5-GeV storage ring having 160 pm-rad emittance with stored beam current of 1.5 A, providing >10{sup 22} brightness for multi-keV photon beams from 3.5-m undulator sources. The team has also investigated possible 5-GeV ERL configurations which, similar to the Cornell and KEK ERL plans, would have {approx}30 pm-rad emittance with 100 mA current, and {approx}10 pm-rad emittance with 25 mA or less. Now a 4.5-GeV 'ultimate' storage ring having emittance similar to the ERL and operating with {approx}200 mA is under study. An overview of the progress of the PEP-X design study and SSRL's plans for defining performance parameters that will guide the choice of ring options is presented.

  5. RF Design for the Linac Coherent Light Source (LCLS) Injector

    CERN Document Server

    Dowell, D H; Boyce, Richard F; Hodgson, J A; Li, Zenghai; Limborg-Deprey, C; Xiao, Liling; Yu, Nancy

    2004-01-01

    The Linac Coherent Light Source (LCLS) will be the world’s first free electron laser, and the successful operation of this very short-wavelength FEL will require excellent beam quality from its electron source. Therefore a critical component is the RF photocathode injector. This paper describes the design issues of the LCLS RF gun and accelerator structures. The injector consists of a 1.6 cell s-band gun followed by two 3-meter SLAC sections. The gun and the first RF section will have dual RF feeds both to eliminate transverse RF kicks and to reduce the pulsed heating of the coupling ports. In addition, the input coupler cavity of the first accelerator section will be specially shaped to greatly reduce the RF quadrupole fields. The design for the accelerator section is now complete, and the RF design of the gun’s dual coupler and the full cell shape is in progress. These and other aspects of the gun and structure designs will be discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, M. [Brookhaven National Lab., Upton, NY (United States). National Synchrotron Light Source

    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.

  7. Perspectives for future light source lattices incorporating yet uncommon magnets

    Directory of Open Access Journals (Sweden)

    S. C. Leemann

    2011-03-01

    Full Text Available Although octupoles, decapoles, and longitudinal gradient bending magnets (LGB have been studied for many years, they are not usually included in light source lattices. They can, however, be beneficial in order to realize ultralow emittance and attain sufficient dynamic aperture. We present methods for achieving ultralow emittance and discuss optimization of the nonlinear dynamics with multipoles. We demonstrate how control of amplitude-dependent tune shift makes octupoles a powerful tool for dynamic aperture optimization. Control of higher-order chromaticity by octupoles and decapoles is straightforward; however, since this turns out to be not quite as efficient in high-brightness lattices with low arc dispersion, we apply it to a conventional lattice to demonstrate the potential. This paper also illustrates how high-field LGBs can be used to build a compact, bright hard x-ray source. Finally, we demonstrate in detail the application of octupoles as integral components of the MAX IV 3 GeV storage ring lattice.

  8. Generating Coherent Phonons and Spin Excitations with Ultrafast Light Pulses

    Science.gov (United States)

    Merlin, Roberto

    2006-03-01

    Recent work on the generation of coherent low-lying excitations by ultrafast laser pulses will be reviewed, emphasizing the microscopic mechanisms of light-matter interaction. The topics covered include long-lived phonons in ZnO [C. Aku-Leh, J. Zhao, R. Merlin, J. Men'endez and M. Cardona, Phys. Rev.B 71, 205211 (2005)], squeezed magnons [J. Zhao, A. V. Bragas, D. J. Lockwood and R. Merlin, Phys. Rev. Lett. 93, 107203 (2004)], spin- and charge-density fluctuations [J. M. Bao et al., Phys. Rev. Lett. 92, 236601 (2004)] and cyclotron resonance [J. K. Wahlstrand, D. M. Wang, P. Jacobs, J. M. Bao, R. Merlin, K. W. West and L. N. Pfeiffer, AIP Conference Proceedings 772 (2005), p. 1313] in GaAs quantum wells. In addition, unpublished results on surface -avoiding phonons in GaAs-AlAs superlattices [M. Trigo et al., unpublished] and magnons in ferromagnetic Ga1-xMnxAs [D. M. Wang et al., unpublished] will be discussed. It will also be shown that frequencies can be measured using pump-probe techniques with a precision comparable to that of Brillouin scattering. It is now widely accepted that stimulated Raman scattering (SRS) is (often but not always) the mechanism responsible for the coherent coupling. Results will be presented showing that SRS is described by two separate tensors, one of which accounts for the excitation-induced modulation of the susceptibility, and the other one for the dependence of the amplitude of the oscillation on the light intensity [T. E. Stevens, J. Kuhl and R. Merlin, Phys. Rev. B 65, 144304 (2002)]. These tensors have the same real component, associated with impulsive coherent generation, but different imaginary parts. If the imaginary term dominates, that is, for strongly absorbing substances, the mechanism for two-band processes becomes displacive in nature, as in the DECP (displacive excitation of coherent phonons) model. It will be argued that DECP is not a separate mechanism, but a particular case of SRS. In the final part of the talk, an

  9. Harnessing structural darkness in the visible and infrared wavelengths for a new source of light

    KAUST Repository

    Huang, Jianfeng

    2015-10-19

    Engineering broadband light absorbers is crucial to many applications, including energy-harvesting devices and optical interconnects. The performances of an ideal absorber are that of a black body, a dark material that absorbs radiation at all angles and polarizations. Despite advances in micrometre-thick films, the absorbers available to date are still far from an ideal black body. Here, we describe a disordered nanostructured material that shows an almost ideal black-body absorption of 98-99% between 400 and 1,400 nm that is insensitive to the angle and polarization of the incident light. The material comprises nanoparticles composed of a nanorod with a nanosphere of 30 nm diameter attached. When diluted into liquids, a small concentration of nanoparticles absorbs on average 26% more than carbon nanotubes, the darkest material available to date. By pumping a dye optical amplifier with nanosecond pulses of 100 mW power, we harness the structural darkness of the material and create a new type of light source, which generates monochromatic emission (5 nm wide) without the need for any resonance. This is achieved through the dynamics of light condensation in which all absorbed electromagnetic energy spontaneously generates single-colour energy pulses. © 2016 Macmillan Publishers Limited. All rights reserved.

  10. Harnessing structural darkness in the visible and infrared wavelengths for a new source of light

    Science.gov (United States)

    Huang, Jianfeng; Liu, Changxu; Zhu, Yihan; Masala, Silvia; Alarousu, Erkki; Han, Yu; Fratalocchi, Andrea

    2016-01-01

    Engineering broadband light absorbers is crucial to many applications, including energy-harvesting devices and optical interconnects. The performances of an ideal absorber are that of a black body, a dark material that absorbs radiation at all angles and polarizations. Despite advances in micrometre-thick films, the absorbers available to date are still far from an ideal black body. Here, we describe a disordered nanostructured material that shows an almost ideal black-body absorption of 98-99% between 400 and 1,400 nm that is insensitive to the angle and polarization of the incident light. The material comprises nanoparticles composed of a nanorod with a nanosphere of 30 nm diameter attached. When diluted into liquids, a small concentration of nanoparticles absorbs on average 26% more than carbon nanotubes, the darkest material available to date. By pumping a dye optical amplifier with nanosecond pulses of ˜100 mW power, we harness the structural darkness of the material and create a new type of light source, which generates monochromatic emission (˜5 nm wide) without the need for any resonance. This is achieved through the dynamics of light condensation in which all absorbed electromagnetic energy spontaneously generates single-colour energy pulses.

  11. Shifted excitation resonance Raman difference spectroscopy using a microsystem light source at 488 nm

    Science.gov (United States)

    Maiwald, M.; Sowoidnich, K.; Schmidt, H.; Sumpf, B.; Erbert, G.; Kronfeldt, H.-D.

    2010-04-01

    Experimental results in shifted excitation resonance Raman difference spectroscopy (SERRDS) at 488 nm will be presented. A novel compact diode laser system was used as excitation light source. The device is based on a distributed feedback (DFB) diode laser as a pump light source and a nonlinear frequency doubling using a periodically poled lithium niobate (PPLN) waveguide crystal. All elements including micro-optics are fixed on a micro-optical bench with a footprint of 25 mm × 5 mm. An easy temperature management of the DFB laser and the crystal was used for wavelength tuning. The second harmonic generation (SHG) provides an additional suppression of the spontaneous emission. Raman spectra of polystyrene demonstrate that no laser bandpass filter is needed for the Raman experiments. Resonance-Raman spectra of the restricted food colorant Tartrazine (FD&C Yellow 5, E 102) in distilled water excited at 488 nm demonstrate the suitability of this light source for SERRDS. A limit of detection (LOD) of 0.4 μmol.l-1 of E102 enables SERRDS at 488 nm for trace detection in e.g. food safety control as an appropriate contactless spectroscopic technique.

  12. The Potential of an Ultimate Storage Ring for Future Light Sources

    Science.gov (United States)

    Bei, M.; Borland, M.; Cai, Y.; Elleaume, P.; Gerig, R.; Harkay, K.; Emery, L.; Hutton, A.; Hettel, R.; Nagaoka, R.; Robin, D.; Steier, C.

    2010-10-01

    This paper is the report of the working group on Ultimate Storage Rings at the Department of Energy's Basic Energy Sciences Workshop on Physics of Future Light Sources, which took place in Gaithersburg, Maryland on September 15-17, 2009. In this report we address the accelerator design issues related to the next generation of storage ring light sources, deemed "ultimate" storage rings. In our estimation, storage rings have the potential to provide an increase in photon brightness and coherent flux that is two orders of magnitude above that projected for rings currently under construction. In addition to photon brightness and coherent flux, we discuss other directions, such as shorter pulses, tailored bunches, and partial lasing, in which rings could evolve. For the most part we envision ultimate storage rings as an evolutionary advance from existing rings that faces no fundamental technological obstacles. Nevertheless we identify several important areas of R&D that should be pursued to enable the realization of the full potential of ultimate ring light sources.

  13. Measurements and simulations of ultralow emittance and ultrashort electron beams in the linac coherent light source.

    Science.gov (United States)

    Ding, Y; Brachmann, A; Decker, F-J; Dowell, D; Emma, P; Frisch, J; Gilevich, S; Hays, G; Hering, Ph; Huang, Z; Iverson, R; Loos, H; Miahnahri, A; Nuhn, H-D; Ratner, D; Turner, J; Welch, J; White, W; Wu, J

    2009-06-26

    The Linac Coherent Light Source (LCLS) is an x-ray free-electron laser project presently in a commissioning phase at the SLAC National Accelerator Laboratory. We report here on very low-emittance measurements made at low bunch charge, and a few femtosecond bunch length produced by the LCLS bunch compressors. Start-to-end simulations associated with these beam parameters show the possibilities of generating hundreds of GW at 1.5 A x-ray wavelength and nearly a single longitudinally coherent spike at 1.5 nm with 2-fs duration.

  14. Structural color analysis of the photoresist grating influenced by the light source and its parameters.

    Science.gov (United States)

    Zeng, Siwei; Liu, Zhengkun; Qiu, Keqiang; Liu, Ying; Xu, Xiangdong; Fu, Shaojun

    2017-03-01

    The basic principle and method to generate structural color from the photoresist grating of the multilayer dielectric diffraction grating are introduced. Rigorous coupled-wave analysis is used for computation with the open software RCWA-1D. The relationships between the characteristics of the photoresist and the structural color are explained. This paper discusses the effect of light source characteristics on the duty cycle color resolution, indicating that TE polarization is better than TM polarization, and the FWHM should be sufficiently large with an optimized value for the incident angle.

  15. Supercontinuum optimization for dual-soliton based light sources using genetic algorithms in a Grid platform

    CERN Document Server

    Arteaga-Sierra, F R; Torres-Gómez, I; Torres-Cisneros, M; Moltó, G; Ferrando, A

    2014-01-01

    We present a numerical strategy to design fiber based dual pulse light sources exhibiting two predefined spectral peaks in the anomalous group velocity dispersion regime. The frequency conversion is based on the soliton fission and soliton self-frequency shift occurring during supercontinuum generation. The optimization process is carried out by a genetic algorithm that provides the optimum input pulse parameters: wavelength, temporal width and peak power. This algorithm is implemented in a Grid platform in order to take advantage of distributed computing. These results are useful for optical coherence tomography applications where bell-shaped pulses located in the second near-infrared window are needed.

  16. Long distance active hyperspectral sensing using high-power near-infrared supercontinuum light source.

    Science.gov (United States)

    Manninen, Albert; Kääriäinen, Teemu; Parviainen, Tomi; Buchter, Scott; Heiliö, Miika; Laurila, Toni

    2014-03-24

    A hyperspectral remote sensing instrument employing a novel near-infrared supercontinuum light source has been developed for active illumination and identification of targets. The supercontinuum is generated in a standard normal dispersion multi-mode fiber and has 16 W total optical output power covering 1000 nm to 2300 nm spectral range. A commercial 256-channel infrared spectrometer was used for broadband infrared detection. The feasibility of the presented hyperspectral measurement approach was investigated both indoors and in the field. Reflection spectra from several diffusive targets were successfully measured and a measurement range of 1.5 km was demonstrated.

  17. CDApps: integrated software for experimental planning and data processing at beamline B23, Diamond Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Rohanah, E-mail: rohanah.hussain@diamond.ac.uk; Benning, Kristian; Javorfi, Tamas; Longo, Edoardo; Rudd, Timothy R.; Pulford, Bill; Siligardi, Giuliano, E-mail: rohanah.hussain@diamond.ac.uk [Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2015-01-31

    CDApps software at Diamond B23 SRCD beamline is presented. The B23 Circular Dichroism beamline at Diamond Light Source has been operational since 2009 and has seen visits from more than 200 user groups, who have generated large amounts of data. Based on the experience of overseeing the users’ progress at B23, four key areas requiring the most assistance are identified: planning of experiments and note-keeping; designing titration experiments; processing and analysis of the collected data; and production of experimental reports. To streamline these processes an integrated software package has been developed and made available for the users. The subsequent article summarizes the main features of the software.

  18. Experience with low-alpha lattices at the Diamond Light Source

    Science.gov (United States)

    Martin, I. P. S.; Rehm, G.; Thomas, C.; Bartolini, R.

    2011-04-01

    In this paper we present the experience at Diamond Light Source in the design, implementation, and operation of low momentum compaction factor lattices for the generation of short x-ray pulses and coherent THz radiation. The effects of higher-order terms in the expansion of the momentum compaction factor on beam dynamics are reviewed from a theoretical point of view, and the details of both high- and low-emittance solutions at Diamond are discussed. Measurements taken to characterize the lattices under a variety of machine conditions are presented, along with the practical limitations that exist as the momentum compaction factor is made to approach zero.

  19. CDApps: integrated software for experimental planning and data processing at beamline B23, Diamond Light Source.

    Science.gov (United States)

    Hussain, Rohanah; Benning, Kristian; Javorfi, Tamas; Longo, Edoardo; Rudd, Timothy R; Pulford, Bill; Siligardi, Giuliano

    2015-03-01

    The B23 Circular Dichroism beamline at Diamond Light Source has been operational since 2009 and has seen visits from more than 200 user groups, who have generated large amounts of data. Based on the experience of overseeing the users' progress at B23, four key areas requiring the most assistance are identified: planning of experiments and note-keeping; designing titration experiments; processing and analysis of the collected data; and production of experimental reports. To streamline these processes an integrated software package has been developed and made available for the users. The subsequent article summarizes the main features of the software.

  20. Microbunch Instability Observations from a THz Detector at Diamond Light Source

    Science.gov (United States)

    Shields, W.; Bartolini, R.; Boorman, G.; Karataev, P.; Lyapin, A.; Puntree, J.; Rehm, G.

    2012-05-01

    Diamond Light source is a third generation synchrotron facility dedicated to producing radiation of outstanding brightness, ranging from infra-red to x-rays. The short electron bunches that are accelerated around the storage ring are susceptible to the phenomenon of microbunching instabilities when the bunch charge exceeds a threshold. The primary feature of the microbunch instabilities is the onset of bursts of radiation in the THz range. The high frequencies involved in the emissions make detection and analysis challenging. A 60-90 GHz Schottky Barrier Diode detector was installed to investigate turn by turn evolution of the instabilities.

  1. Performance of a beam-multiplexing diamond crystal monochromator at the Linac Coherent Light Source

    OpenAIRE

    Zhu, Diling; Feng, Yiping; Stoupin, Stanislav; Terentyev, Sergey A.; Lemke, Henrik T.; Fritz, David M.; Chollet, Matthieu; Glownia, J. M.; Alonso-Mori, Roberto; Sikorski, Marcin; Song, Sanghoon; Brandt van Driel, Tim; Williams, Garth J; Messerschmidt, Marc; Boutet, Sébastien

    2014-01-01

    A double-crystal diamond monochromator was recently implemented at the Linac Coherent Light Source. It enables splitting pulses generated by the free electron laser in the hard x-ray regime and thus allows the simultaneous operations of two instruments. Both monochromator crystals are High-Pressure High-Temperature grown type-IIa diamond crystal plates with the (111) orientation. The first crystal has a thickness of ∼100 μm to allow high reflectivity within the Bragg bandwidth and good transm...

  2. Development of liquid-jet laser-produced plasma light source for EUV lithography

    Science.gov (United States)

    Abe, Tamotsu; Suganuma, Takashi; Imai, Yousuke; Sugimoto, Yukihiko; Someya, Hiroshi; Hoshino, Hideo; Soumagne, Georg; Komori, Hiroshi; Mizoguchi, Hakaru; Endo, Akira; Toyoda, Koichi

    2003-06-01

    The Extreme UV Lithography System Development Association (EUVA) was established in Japan in May 2002 and is supported by the Ministry of Economy, Trade and Industry (METI). EUVA started the light soruce development in September 2002. This development is done by the assocaition members Gigaphoton, Ushio, Komatsu, Canon, Nikon, the National Institute of Advanced Industrial Sciecne and Technology (AIST) and several Japanese universities. The target of the four-year project is the development of a EUV light source with 10W clean focus point power. For the end of the fiscal year 2003 the development of a 4W EUV light source (clean focus point power) is planned. Both, Laser-Produced-Plasma (LPP) and Discharge-Produced-Plasma (DPP) EUV light sources are investigated at first. Our group at the EUVA Hiratsuka R&D Center is working on LPP sources. We are currently focusing on the development of a driver laser and a liquid Xenon plasma target. The laser is a Nd:YAG MOPA (Master Oscillator and Power Amplifier) system oscillating at 1064 nm. Average power, repetition rate and pulse duration of the laser system are 500 Watt, 10 kHa and 30nsec, respectively. The Xenon liquefication system operates at a maximum pressure of 5MPa and a temperature range between 160 K and 190 K. The pressure inside the vacuum chamber is below 0.1Pa during system operation. This paper presents the current status of the EUV system component development as well as first experimental results of generated EUV radiation.

  3. Magnetic flux tubes as sources of wave generation

    Science.gov (United States)

    Musielak, Z. E.; Rosner, R.; Ulmschneider, P.

    1987-01-01

    The structure of solar, and very likely stellar, surface magnetic fields is highly inhomogeneous: at the photospheric level, the fields are locally strong, and show concentration into a flux tube structure. In this case, the wave energy generated in stellar convection zones may be largely carried away by flux tube waves, which can then become important sources for the heating of the outer atmospheric layers. Such flux tube wave generation may help to explain the UV and X-ray fluxes observed by the IUE and Einstein observatories. The generation of longitudinal tube waves in magnetic flux tubes embedded in an otherwise magnetic field-free, turbulent, and stratified medium was considered. It is shown that compressible tube waves are generated by dipole emission and that the generation efficiency is a strong function of the magnetic field strength. Energy flux calculations are presented for different magnetic flux tubes, and show how the results depend on the magnetic field strength and the characteristics of the convective turbulence.

  4. Linac Coherent Light Source (LCLS) Conceptual Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Nuhn, Heinz-Dieter

    2002-11-25

    The Stanford Linear Accelerator Center, in collaboration with Argonne National Laboratory, Brookhaven National Laboratory, Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, have collaborated to create a conceptual design for a Free-Electron-Laser (FEL) R&D facility operating in the wavelength range 1.5-15 {angstrom}. This FEL, called the ''Linac Coherent Light Source'' (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. The first two-thirds of the SLAC linac are used for injection into the PEP-II storage rings. The last one-third will be converted to a source of electrons for the LCLS. The electrons will be transported to the SLAC Final Focus Test Beam (FFTB) Facility, which will be extended to house a 122-m undulator system. In passing through the undulators, the electrons will be bunched by the force of their own synchrotron radiation to produce an intense, spatially coherent beam of x-rays, tunable in energy from 0.8 keV to 8 keV. The LCLS will include two experiment halls as well as x-ray optics and infrastructure necessary to make use of this x-ray beam for research in a variety of disciplines such as atomic physics, materials science, plasma physics and biosciences. This Conceptual Design Report, the authors believe, confirms the feasibility of constructing an x-ray FEL based on the SLAC linac.

  5. VOLCANIC TSUNAMI GENERATING SOURCE MECHANISMS IN THE EASTERN CARIBBEAN REGION

    Directory of Open Access Journals (Sweden)

    George Pararas-Carayannis

    2004-01-01

    ée on Martinique, of Soufriere on St. Vincent and of the Kick’em Jenny underwater volcano near Grenada and provides an overall risk assessment of tsunami generation from volcanic sources in the Caribbean region.

  6. A Proposal for a Next Generation European Neutron Source

    Science.gov (United States)

    Andersen, K. H.; Carlile, C. J.

    2016-09-01

    We argue that it is not too early to begin the planning process for a next generation neutron source for Europe, even as the European Spallation Source is being constructed. We put forward three main arguments. Firstly, nowadays the period between the first scientific concept of a new facility being proposed and its actual realisation is approaching half a century. We show evidence for this. Secondly, there is a straightforward development of the short pulse/long pulse spallation concepts that will deliver gains in neutron brightness of more than a factor 30 over what the ESS will soon deliver and provide the optimum balance between resolution and intensity. We describe our concept, which is a spallation source where the proton pulse length is matched to the moderating time of slow neutrons. Thirdly, when we look at our colleagues in astronomy and high energy physics, we see that they have a totally different, more global and more ambitious approach to the coming generations of large facilities. We argue that it is time for the neutron community not simply to rest upon its laurels and take what is given but to be proactive..

  7. Biogas as a fuel source for SOFC co-generators

    Science.gov (United States)

    Van herle, Jan; Membrez, Yves; Bucheli, Olivier

    This study reports on the combination of solid oxide fuel cell (SOFC) generators fueled with biogas as renewable energy source, recoverable from wastes but at present underexploited. From a mobilisable near-future potential in the European Union (EU-15) of 17 million tonnes oil equivalent (Mtoe), under 15% appears to be converted today into useful heat and power (2 Mtoe). SOFCs could improve and promote the exploitation of biogas on manifold generation sites as small combined heat and power (5-50 kW el), especially for farm and sewage installations, raising the electrical conversion efficiency on such reduced and variable power level. Larger module packs of the high temperature ceramic converter would also be capable of operating on contaminated fuel of low heating value (less than 40% that of natural gas) which can emanate from landfill sites (MW-size). Landfill gas delivers 80% of current world biogas production. This document compiles and estimates biogas data on actual production and future potential and presents the thermodynamics of the biogas reforming and electrochemical conversion processes. A case study is reported of the energy balance of a small SOFC co-generator operated with agricultural biogas, the largest potential source.

  8. Feasibility of Ultraviolet Light Emitting Diodes as an Alternative Light Source for Photocatalysis

    Science.gov (United States)

    Levine, Langanf H.; Richards, Jeffrey T.; Soler, Robert; Maxik, Fred; Coutts, Janelle; Wheeler, Raymond M.

    2011-01-01

    The objective of this study was to determine whether ultraviolet light emitting diodes (UV-LEDs) could serve as an alternative photon source efficiently for heterogeneous photocatalytic oxidation (PCO). An LED module consisting of 12 high-power UV-A LEDs was designed to be interchangeable with a UV-A fluorescent black light blue (BLB) lamp in a Silica-Titania Composite (STC) packed bed annular reactor. Lighting and thermal properties were characterized to assess the uniformity and total irradiant output. A forward current of (I(sub F)) 100 mA delivered an average irradiance of 4.0 m W cm(exp -2), which is equivalent to the maximum output of the BLB, but the irradiance of the LED module was less uniform than that of the BLB. The LED- and BLB-reactors were tested for the oxidization of 50 ppmv ethanol in a continuous flow-through mode with 0.94 sec space time. At the same irradiance, the UV-A LED reactor resulted in a lower PCO rate constant than the UV-A BLB reactor (19.8 vs. 28.6 nM CO2 sec-I), and consequently lower ethanol removal (80% vs. 91%) and mineralization efficiency (28% vs. 44%). Ethanol mineralization increased in direct proportion to the irradiance at the catalyst surface. This result suggests that reduced ethanol mineralization in the LED- reactor could be traced to uneven irradiance over the photocatalyst, leaving a portion of the catalyst was under-irradiated. The potential of UV-A LEDs may be fully realized by optimizing the light distribution over the catalyst and utilizing their instantaneous "on" and "off' feature for periodic irradiation. Nevertheless, the current UV-A LED module had the same wall plug efficiency (WPE) of 13% as that of the UV-A BLB. These results demonstrated that UV-A LEDs are a viable photon source both in terms of WPE and PCO efficiency.

  9. Linac Coherent Light Source (LCLS) design study report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    The Stanford Linear Accelerator Center (SLAC), in collaboration with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, is proposing to build a Free-Electron-Laser (FEL) R and D facility operating in the self-amplified spontaneous emission (SASE) mode in the wavelength range 1.5--15 {angstrom}. This FEL, called Linac Coherent Light Source (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. In this report, the Design Team has established performance parameters for all the major components of the LCLS and developed a layout of the entire system. Chapter 1 is the Executive Summary. Chapter 2 (Overview) provides a brief description of each of the major sections of the LCLS, from the rf photocathode gun, through the experimental stations and electron beam dump. Chapter 3 describes the scientific case for the LCLS. Chapter 4 provides a review of the principles of the FEL physics that the LCLS is based on, and Chapter 5 discusses the choice of the system's physical parameters. Chapters 6 through 10 describe in detail each major element of the system. Chapters 11 through 13 respectively cover undulator controls, mechanical alignment, and radiation issues.

  10. Use of an alternative light source to assess strangulation victims.

    Science.gov (United States)

    Holbrook, Debra S; Jackson, M Christine

    2013-01-01

    Alternative light sources (ALSs) are commonly used at crime scenes and in forensic laboratories to collect evidence such as latent fingerprints, body fluids, hair, and fibers. This article describes the use of this technology to reveal soft tissue injuries that are not visible to the naked or unaided eye in patients who report strangulation. The value of this information to the medical, nursing, and judicial systems is discussed. The records of the 172 strangulation patients seen in our forensic nurse examiner program between 2009 and 2010 were reviewed. The SPEX Crimescope (SPEX Forensics, Edison, New Jersey) was used during the assessment of all of them. Ninety-three percent of the patients had no visible evidence of external injuries on physical examination. The ALS revealed positive findings of intradermal injuries in 98% of that group. Information obtained with ALS devices helps medical and nursing practitioners understand the gravity of patients' injuries, influences medical treatment decisions and follow-up care, and supports the prosecution of the perpetrators of crimes of violence. Educational programs about the application of ALS and the interpretation of its findings are valuable for medical, nursing, and other forensic disciplines.

  11. Handling high data rate detectors at Diamond Light Source

    Science.gov (United States)

    Pedersen, U. K.; Rees, N.; Basham, M.; Ferner, F. J. K.

    2013-03-01

    An increasing number of area detectors, in use at Diamond Light Source, produce high rates of data. In order to capture, store and process this data High Performance Computing (HPC) systems have been implemented. This paper will present the architecture and usage for handling high rate data: detector data capture, large volume storage and parallel processing. The EPICS area Detector frame work has been adopted to abstract the detectors for common tasks including live processing, file format and storage. The chosen data format is HDF5 which provides multidimensional data storage and NeXuS compatibility. The storage system and related computing infrastructure include: a centralised Lustre based parallel file system, a dedicated network and a HPC cluster. A well defined roadmap is in place for the evolution of this to meet demand as the requirements and technology advances. For processing the science data the HPC cluster allow efficient parallel computing, on a mixture of ×86 and GPU processing units. The nature of the Lustre storage system in combination with the parallel HDF5 library allow efficient disk I/O during computation jobs. Software developments, which include utilising optimised parallel file reading for a variety of post processing techniques, are being developed in collaboration as part of the Pan-Data EU Project (www.pan-data.eu). These are particularly applicable to tomographic reconstruction and processing of non crystalline diffraction data.

  12. Final Report, Photocathodes for High Repetition Rate Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Zvi, Ilan [Stony Brook University

    2014-04-20

    This proposal brought together teams at Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL) and Stony Brook University (SBU) to study photocathodes for high repetition rate light sources such as Free Electron Lasers (FEL) and Energy Recovery Linacs (ERL). The work done under this grant comprises a comprehensive program on critical aspects of the production of the electron beams needed for future user facilities. Our program pioneered in situ and in operando diagnostics for alkali antimonide growth. The focus is on development of photocathodes for high repetition rate Free Electron Lasers (FELs) and Energy Recovery Linacs (ERLs), including testing SRF photoguns, both normal-conducting and superconducting. Teams from BNL, LBNL and Stony Brook University (SBU) led this research, and coordinated their work over a range of topics. The work leveraged a robust infrastructure of existing facilities and the support was used for carrying out the research at these facilities. The program concentrated in three areas: a) Physics and chemistry of alkali-antimonide cathodes b) Development and testing of a diamond amplifier for photocathodes c) Tests of both cathodes in superconducting RF photoguns and copper RF photoguns

  13. Interaction between hollow needles - electric field, light emission and ozone generation study in multineedle to plate electrical discharge

    Science.gov (United States)

    Kriha, Vitezslav

    2004-09-01

    Multi hollow needle to plate electrical discharges in air are studied as ozone sources. Dependence of ozone concentration as an function of applied voltage, discharge current, mutual hollow needles position and electrical connection, working gas flow rate, distances between needles tips and plate electrode, visible light emission was measured experimentally in these systems. Electric field was numerically modeled. Light emission and electrical field distributions were compared. Coming from light emission and electric field a model of energy density spatial distribution was built. This model was finally compared with ozone generation.

  14. Environmental friendly high efficient light source. Plasma lamp. 2006 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Courret, G.

    2006-07-01

    This annual report for 2006 for the Swiss Federal Office of Energy (SFOE) reports on work being done on the development of a high-efficiency source of light based on the light emission of a plasma. The report presents a review of work done in 2006, including thermodynamics and assessment of the efficiency of the magnetron, tests with small bulbs, study of the standing wave ratio (microwave fluxes) and the development of a new coupling system to allow ignition in very small bulbs. Also, knowledge on the fillings of the bulb and induced effects of the modulator were gained. The development of a second generation of modulator to obtain higher efficiency at lower power is noted.

  15. A nano-graphite cold cathode for an energy-efficient cathodoluminescent light source

    Directory of Open Access Journals (Sweden)

    Alexander N. Obraztsov

    2013-08-01

    Full Text Available The development of new types of light sources is necessary in order to meet the growing demands of consumers and to ensure an efficient use of energy. The cathodoluminescence process is still under-exploited for light generation because of the lack of cathodes suitable for the energy-efficient production of electron beams and appropriate phosphor materials. In this paper we propose a nano-graphite film material as a highly efficient cold cathode, which is able to produce high intensity electron beams without energy consumption. The nano-graphite film material was produced by using chemical vapor deposition techniques. Prototypes of cathodoluminescent lamp devices with a construction optimized for the usage of nano-graphite cold cathodes were developed, manufactured and tested. The results indicate prospective advantages of this type of lamp and the possibility to provide advanced power efficiency as well as enhanced spectral and other characteristics.

  16. A virtual source pattern method for fluorescence tomography with structured light.

    Science.gov (United States)

    Ducros, Nicolas; D'Andrea, Cosimo; Bassi, Andrea; Valentini, Gianluca; Arridge, Simon

    2012-06-21

    In order to reduce both acquisition and reconstruction times, illumination and detection in fluorescence diffuse optical tomography (FDOT) have recently evolved from a point-based to a pattern-based approach. The use of structured illumination, offering the ability to project any pattern of light onto the object, associated with the compression of the acquired fluorescence images has paved the way for a new generation of fast reconstruction algorithms for FDOT. However, the choice of the most appropriate set of source patterns is still an open problem. Here, the use of typical source patterns is investigated on experimental data. Reconstructions of similar qualities are obtained for the different types of source patterns. We found that the performances of structured illumination are limited by the required positivity of the source patterns. To alleviate this problem, we introduce a novel method, namely the virtual source pattern method, which allows for considering any kind of patterns, e.g., with negative and complex intensities. This new method provides a significant increase of the contrast of the reconstruction and also a reduction of the reconstruction error, especially when virtual wavelet source patterns are considered.

  17. Handling radiation generated during an ion source commissioning

    Science.gov (United States)

    Ren, H. T.; Zhao, J.; Peng, S. X.; Lu, P. N.; Zhou, Q. F.; Xu, Y.; Chen, J.; Zhang, T.; Zhang, A. L.; Guo, Z. Y.; Chen, J. E.

    2014-02-01

    Radiation is an important issue, which should be carefully treated during the design and commissioning of an ion source. Measurements show that X-rays are generated around the ceramics column of an extraction system when the source is powered up to 30 kV. The X-ray dose increases greatly when a beam is extracted. Inserting the ceramic column into a metal vacuum box is a good way to block X-ray emission for those cases. Moreover, this makes the online test of an intense H+ ion beam with energy up to 100 keV possible. However, for deuteron ion source commissioning, neutron and gamma-ray radiation become a serious topic. In this paper, we will describe the design of the extraction system and the radiation doses of neutrons and gamma-rays measured at different D+ beam energy during our 2.45 GHz deuteron electron cyclotron resonance ion source commissioning for PKUNIFTY (PeKing University Neutron Imaging FaciliTY) project at Peking University.

  18. Next Generation Luminaires: Recognizing Innovative, Energy-Efficient Commercial Lighting Luminaires

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-04-01

    Fact sheet that describes the Next Generation Luminaires SSL lighting design competition, which recognizes excellence in technical innovation and design of high-quality, energy-efficient commercial lighting, both indoor and outdoor.

  19. Next-Generation Photon Sources for Grand Challenges in Science and Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-05-01

    The next generation of sustainable energy technologies will revolve around transformational new materials and chemical processes that convert energy efficiently among photons, electrons, and chemical bonds. New materials that tap sunlight, store electricity, or make fuel from splitting water or recycling carbon dioxide will need to be much smarter and more functional than today's commodity-based energy materials. To control and catalyze chemical reactions or to convert a solar photon to an electron requires coordination of multiple steps, each carried out by customized materials and interfaces with designed nanoscale structures. Such advanced materials are not found in nature the way we find fossil fuels; they must be designed and fabricated to exacting standards, using principles revealed by basic science. Success in this endeavor requires probing, and ultimately controlling, the interactions among photons, electrons, and chemical bonds on their natural length and time scales. Control science - the application of knowledge at the frontier of science to control phenomena and create new functionality - realized through the next generation of ultraviolet and X-ray photon sources, has the potential to be transformational for the life sciences and information technology, as well as for sustainable energy. Current synchrotron-based light sources have revolutionized macromolecular crystallography. The insights thus obtained are largely in the domain of static structure. The opportunity is for next generation light sources to extend these insights to the control of dynamic phenomena through ultrafast pump-probe experiments, time-resolved coherent imaging, and high-resolution spectroscopic imaging. Similarly, control of spin and charge degrees of freedom in complex functional materials has the potential not only to reveal the fundamental mechanisms of high-temperature superconductivity, but also to lay the foundation for future generations of information science. This

  20. Classification of light sources and their interaction with active and passive environments

    CERN Document Server

    El-Dardiry, Ramy G S; Lagendijk, Ad

    2010-01-01

    The emission properties of a molecular light source depend on its optical and chemical environment. This dependence, however, is different for various light sources. We present a general classification of sources by introducing the concepts of Constant Amplitude and Constant Power Sources. The unforeseen consequences of this classification are illustrated for photonic studies by random laser experiments. Comparison of the experimental results with properly customized rate equations identifies the type of light source in the gain medium and an estimate for its quantum efficiency. Our results require a major revision of source studies in multiple scattering media.

  1. Overdense plasma generation in a compact ion source

    Science.gov (United States)

    Castro, G.; Mascali, D.; Gammino, S.; Torrisi, G.; Romano, F. P.; Celona, L.; Altana, C.; Caliri, C.; Gambino, N.; Lanaia, D.; Miracoli, R.; Neri, L.; Sorbello, G.

    2017-05-01

    Electron cyclotron resonance ion sources (ECRIS) are widely used plasma based machines for the production of intense ion beams in science and industry. The performance of modern devices is limited by the presence of the density cut-off, above which electromagnetic (EM) waves sustaining the plasma are reflected. We hereby discuss the systematic data analysis of electrostatic wave generation in an ECR prototype operating at 3.75 GHz-0.1 THz. In particular, electron Bernstein waves (EBW) have been excited. EBW have already been generated in large-scale plasma devices for thermonuclear fusion purposes. In ion sources where L c ˜ λ RF (L c being the plasma chamber size and λ RF the pumping wave wavelength) the EM field assumes a modal behaviour; thus both plasma and EM field self-organize so that no optical-like wave launching is possible (i.e. the cavity effect dominates on the optical path). The collected data, however, supported by 3D full-wave simulations, actually demonstrate that a Budden-type X-B conversion scenario can be established above some critical RF power thresholds, operating in an off-ECR regime. The generation and absorption of the EBW has been demonstrated by the presence of three peculiar signatures: along with the establishment of an overdense plasma, generation of supra-thermal electrons and modification (non-linear broadening) of the EM spectrum measured within the plasma have been observed. At the threshold establishing such a heating regime, the collected data provide evidence for a fast rotation of the electron fluid.

  2. EDITORIAL: Extreme Ultraviolet Light Sources for Semiconductor Manufacturing

    Science.gov (United States)

    Attwood, David

    2004-12-01

    issue of available EUV power from electrical discharge pinch plasmas and laser produced plasmas, including the roots of these requirements, the relevant plasma and radiation physics, and current state-of-the-art commercial technology. In the first paper of the cluster, Vadim Banine and Roel Moors of ASML in the Netherlands provide a detailed review of the required EUV power based on an economically viable throughput of one hundred 300 mm diameter wafers per hour, projected resist sensitivity, number of finite reflectivity multilayer coated surfaces and their collective spectral bandwidth, and a collection solid angle set by optical phase-space constraints and plasma source size. Thomas Krücken and his colleagues from Philips and the Fraunhofer Institute in Aachen present a theoretical model of radiation generation and transport based on model density and temperature profiles in an electrical discharge plasma, providing valuable insights into radiation physics and the limits to achievable power. Kenneth Fahy and his colleagues at UCD in Dublin and NIST in the US, in their paper, describe in detail atomic physics calculations of emission from relevant lines and unresolved transition arrays (UTAs) of candidate xenon and tin ions, each of which radiate strongly within the acceptance bandwidth of the multilayer coatings. The different elements, Xe and Sn, however, raise significantly different implications for source debris production and thus of requisite debris mitigation requirements. Björn Hannson and Hans Hertz of KTH University in Stockholm present a substantial review of laser produced plasmas for the EUV, including those based on liquid jet technologies, leading to a path of mass limited target material, and significant stand-off distance from the solid nozzle, which maximize EUV power generation while minimizing debris production. In addition to an extensive review of EUV source related literature, they describe experiments with laser irradiated droplets and

  3. Two-function light source in a FBG multi-point sensing system

    Institute of Scientific and Technical Information of China (English)

    HE Shi-ya; DENG Yan-hao; YU Yang; HU Shu-yang; GUAN Zheng

    2007-01-01

    In this paper, a two-function light source is recommended. It can both amplify the light power and demodulate the wavelength signal. Its output power is 1000 times as high as traditional broadband light source (BBS) and it can demodulate the signal by scanning wavelength in 30 nmof bandwidth range in the situation of 1550 nm central wavelength. This kind of light source effectively solves the problem of light energy supply in more-point measurement of FBG and simplifies the structure of sensing measurement.

  4. Development of Electricity Generation from Renewable Energy Sources in Turkey

    Science.gov (United States)

    Kentel, E.

    2011-12-01

    Electricity is mainly produced from coal, natural gas and hydropower in Turkey. However, almost all the natural gas and high quality coal are imported. Thus, increasing the shares of both hydro and other renewables in energy supply is necessary to decrease dependency of the country on foreign sources. In 2008, the total installed capacity of Turkey was around 42000 MW and 66 % of this was from thermal sources. The remaining 33 % was from hydro, which leaves only one percent for the other renewable energy sources. The share of renewable energy in the energy budget of Turkey has increased in the last two decades; however, in 2008, only 17 % of the total electricity generation was realized from renewable sources most of which was hydro. According to State Hydraulic Works (SHW) which is the primary executive state agency responsible for the planning, operating and managing of Turkey's water resources, Turkey utilizes only around 35% of its economically viable hydro potential. The current situation clearly demonstrates the need for increasing the share of renewables in the energy budget. New laws, such as the Electricity Market Law, have been enacted and the following items were identified by the Ministry of Energy and Natural Resources of Turkey among primary energy policies and priorities: (i) decreasing dependency on foreign resources by prioritizing utilization of natural resources, (ii) increasing the share of renewable energy resources in the energy budget of Turkey; (iii) minimization of adverse environmental impacts of production and utilization of natural resources. The government's energy policy increased investments in renewable energy resources; however lack of a needed legal framework brought various environmental and social problems with this fast development. The development of the share of renewable resources in the energy budget, current government policy, and environmental concerns related with renewables, and ideas to improve the overall benefits of

  5. Integrated Wavelength-Tunable Light Source for Optical Gas Sensing Systems

    Directory of Open Access Journals (Sweden)

    Bin Li

    2015-01-01

    Full Text Available A compact instrument consisting of a distributed feedback laser (DFB at 1.65 μm was developed as a light source for gas sensing systems using tunable diode laser absorption spectroscopy (TDLAS technique. The wavelength of laser is tuned by adjusting the laser working temperature and injection current, which are performed by self-developed temperature controller and current modulator respectively. Stability test shows the fluctuation of the laser temperature is within the range of ±0.02°C. For gas detection experiments, the wavelength is tuned around the gas absorption line by adjusting laser temperature and is then shifted periodically to scan across the absorption line by the laser current modulator, which generates a 10 Hz saw wave signal. In addition, the current modulator is able to generate sine wave signal for gas sensing systems using wavelength modulation spectroscopy (WMS technique involving extraction of harmonic signals. The spectrum test proves good stability that the spectrum was measured 6 times every 10 minutes at the constant temperature and current condition. This standalone instrument can be applied as a light source for detection systems of different gases by integrating lasers at corresponding wavelength.

  6. Soft x-ray spectromicroscopy development for materials science at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Warwick, T.; Padmore, H. [Lawrence Berkeley National Lab., CA (United States); Ade, H. [North Carolina State Univ., Raleigh, NC (United States); Hitchcock, A.P. [McMaster Univ., Hamilton, Ontario (Canada); Rightor, E.G. [Dow Texas Polymer Center, Freeport, TX (United States); Tonner, B.P. [Univ. of Wisconsin, Milwaukee, WI (United States)

    1996-08-01

    Several third generation synchrotron radiation facilities are now operational and the high brightness of these photon sources offers new opportunities for x-ray microscopy. Well developed synchrotron radiation spectroscopy techniques are being applied in new instruments capable of imaging the surface of a material with a spatial resolution smaller than one micron. There are two aspects to this. One is to further the field of surface science by exploring the effects of spatial variations across a surface on a scale not previously accessible to x-ray measurements. The other is to open up new analytical techniques in materials science using x-rays, on a spatial scale comparable to that of the processes or devices to be studied. The development of the spectromicroscopy program at the Advanced Light Source will employ a variety of instruments, some are already operational. Their development and use will be discussed, and recent results will be presented to illustrate their capabilities.

  7. Extreme Ultraviolet Light Emission from Z-Pinch Discharge Plasma Source

    Science.gov (United States)

    Watanabe, Masato; Song, Inho; Sakamoto, Toshiro; Kobayashi, Yasunori; Okino, Akitoshi; Mohanty, Smruti R.; Horioka, Kazuhiko; Hotta, Eiki

    2006-01-01

    A capillary Z-pinch discharge light source for EUV lithography has been developed. Our device is equipped with a water-cooled ceramic capillary and electrodes, and a solid state pulsed power generator. A stacked static induction thyristors are used as switching elements, which enable high repetition rate operation of pulsed power supply. A magnetic switch is connected in series, which not only assists the semiconductor switch but also provides a preionization current. In the present study, EUV radiation emitted from pinching plasma in a xenon-filled capillary was quantitatively measured using an in-band calorimeter. Time-integrated in-band source image was also observed using a pinhole camera system. Furthermore, new electrode system using plasma jet has been developed.

  8. High Energy Laboratory Astrophysics Experiments using electron beam ion traps and advanced light sources

    Science.gov (United States)

    Brown, Gregory V.; Beiersdorfer, Peter; Bernitt, Sven; Eberle, Sita; Hell, Natalie; Kilbourne, Caroline; Kelley, Rich; Leutenegger, Maurice; Porter, F. Scott; Rudolph, Jan; Steinbrugge, Rene; Traebert, Elmar; Crespo-Lopez-Urritia, Jose R.

    2015-08-01

    We have used the Lawrence Livermore National Laboratory's EBIT-I electron beam ion trap coupled with a NASA/GSFC microcalorimeter spectrometer instrument to systematically address problems found in the analysis of high resolution X-ray spectra from celestial sources, and to benchmark atomic physics codes employed by high resolution spectral modeling packages. Our results include laboratory measurements of transition energies, absolute and relative electron impact excitation cross sections, charge exchange cross sections, and dielectronic recombination resonance strengths. More recently, we have coupled to the Max-Plank Institute for Nuclear Physics-Heidelberg's FLASH-EBIT electron beam ion trap to third and fourth generation advanced light sources to measure photoexcitation and photoionization cross sections, as well as, natural line widths of X-ray transitions in highly charged iron ions. Selected results will be presented.

  9. Dynamics of a liquid helium I SRF cryostat at the Canadian Light Source

    Science.gov (United States)

    Regier, Chris

    2012-06-01

    The Canadian Light Source (CLS) is a third-generation synchrotron located inSaskatoon, Canada. A superconducting radio frequency (SRF) cavity contained in a 4.43 Kliquid helium I cryostat is used at the CLS to replenish energy loss in the electron beam. Adynamic simulation of this cryostat has been generated to examine pressure and levelfluctuations due to variations in heat loading or other system parameters. This simulatorhas led to some interesting observations in system behavior, which have been shown tooccur in the actual system as well. For example, mass rates of vaporization appear to dropas heat loading increases under certain conditions. Also, the relationship between pressureand SRF tuning characteristics is examined, and the abilities and limitations of thesimulator are presented.

  10. Solid-state laser source of narrowband ultraviolet B light for skin disease care

    Science.gov (United States)

    Tarasov, Aleksandr A.; Chu, Hong

    2013-03-01

    We report about the development of all-solid-state laser source of narrowband UV-B light for medical applications. The device is based on a gain-switched Ti: Sapphire laser with volume Bragg grating, pumped at 532 nm and operating at 931.8 nm, followed by a third harmonic generator and a fiber optic beam homogenizer. The maximum available pulse energy exceeded 5 mJ at 310.6 nm, with a pulse repetition rates of 50 Hz. The output characteristics satisfy the medical requirements for psoriasis and vitiligo treatment. A new optical scheme for third harmonic generation enhancement at moderate levels of input intensities is proposed and investigated. As a result, 40% harmonic efficiency was obtained, when input pulse power was only 300 kW.

  11. Monte Carlo Simulations of Synchrotron Radiation and Vacuum Performance of the MAX IV Light Sources

    CERN Document Server

    Ady, M; Grabski, M

    2014-01-01

    In the 3 GeV ring of MAX IV light source in Lund, Sweden, the intense synchrotron radiation (SR) distributed along the ring generates important thermal and vacuum effects. By means of a Monte Carlo simulation package, which is currently developed at CERN, both thermal and vacuum effects are quantitatively analysed, in particular near the crotch absorbers and the surrounding NEG-coated vacuum chambers. Using SynRad+, the beam trajectory of the upstream bending magnet is calculated; SR photons are generated and traced through the geometry until their absorption. This allows an analysis of the incident power density on the absorber, and to calculate the photon induced outgassing. The results are imported to Molflow+, a Monte Carlo vacuum simulator that works in the molecular flow regime, and the pressure in the vacuum system and the saturation length of the NEG coating are determined using iterations.

  12. Polymer and small molecule based hybrid light source

    Science.gov (United States)

    Choong, Vi-En; Choulis, Stelios; Krummacher, Benjamin Claus; Mathai, Mathew; So, Franky

    2010-03-16

    An organic electroluminescent device, includes: a substrate; a hole-injecting electrode (anode) coated over the substrate; a hole injection layer coated over the anode; a hole transporting layer coated over the hole injection layer; a polymer based light emitting layer, coated over the hole transporting layer; a small molecule based light emitting layer, thermally evaporated over the polymer based light emitting layer; and an electron-injecting electrode (cathode) deposited over the electroluminescent polymer layer.

  13. Next Generation H- Ion Sources for the SNS

    Energy Technology Data Exchange (ETDEWEB)

    Welton, Robert F [ORNL; Carmichael, Justin R [ORNL; Carr, Jr, Jerry [ORNL; Crisp, Danny W [ORNL; Goulding, Richard Howell [ORNL; Han, Baoxi [ORNL; Pennisi, Terry R [ORNL; Murray Jr, S N [ORNL; Stockli, Martin P [ORNL; Tarvainen, Olli A [ORNL; Santana, Manuel [ORNL

    2009-01-01

    The U.S. Spallation Neutron Source (SNS) is the leading accelerator-based, pulsed neutron-scattering facility, currently in the process of ramping up neutron production. In order to insure meeting operational requirements as well as providing for future facility beam power upgrades, a multifaceted H{sup -} ion source development program is ongoing. This work discusses several aspects of this program, specifically the design and first beam measurements of an RF-driven, external antenna H{sup -} ion source based on an AlN ceramic plasma chamber, elemental and chromate Cs-systems, and plasma ignition gun. Unanalyzed beam currents of up to {approx}100 mA (60Hz, 1ms) have been observed and sustained currents >60 mA (60Hz, 1ms) have been demonstrated on the test stand. Accelerated beam currents of {approx}40 mA have also been demonstrated into the SNS front end. Data are also presented describing the first H{sup -} beam extraction experiments from a helicon plasma generator based on the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine design.

  14. Generation of intense circularly polarized attosecond light bursts from relativistic laser plasmas

    CERN Document Server

    Ma, Guangjin; Yu, M Y; Shen, Baifei; Veisz, Laszlo

    2016-01-01

    We have investigated the polarization of attosecond light bursts generated by nanobunches of electrons from relativistic few-cycle laser pulse interaction with the surface of overdense plasmas. Particle-in-cell simulation shows that the polarization state of the generated attosecond burst depends on the incident-pulse polarization, duration, carrier envelope phase, as well as the plasma scale length. Through laser and plasma parameter control, without compromise of generation efficiency, a linearly polarized laser pulse with azimuth $\\theta^i=10^\\circ$ can generate an elliptically polarized attosecond burst with azimuth $|\\theta^r_{\\rm atto}|\\approx61^\\circ$ and ellipticity $\\sigma^r_{\\rm atto}\\approx0.27$; while an elliptically polarized laser pulse with $\\sigma^i\\approx0.36$ can generate an almost circularly polarized attosecond burst with $\\sigma^r_{\\rm atto}\\approx0.95$. The results propose a new way to a table-top circularly polarized XUV source as a probe with attosecond scale time resolution for many a...

  15. Experimental investigation on thermoelectric generator of micro hybrid power source

    Science.gov (United States)

    Shang, Yonghong; Li, Yanqiu; Yu, Hongyun; Sun, Hongguang; Su, Bo

    2007-12-01

    The micro power system, which is composed of photovoltaic solar cell, heat conductor, thermoelectric generator (TEG) module and fin heat sink has been developed in our laboratory. A photovoltaic silicon solar cell of the P-N junction type is sensitive to radiant energy of wavelength from 5,000 Å to 12,000 Å. Radiation under and within this range is converted not only into electric energy but also into heat energy. The wavelength longer than this range is also converted into heat energy, which degrades the conversion efficiency of the solar cell. TEG produces electrical power from temperature difference via Seebeck effect that can be put under the solar cell to absorb the heat. The heat energy can be converted into electrical power. It was found that when TEG surface area was 150mm×60mm, it could generate 0.24V output voltage and 4.18mA short circuit at ambient temperature varying between 5-10°C at winter. It also could generate 1.3V output voltage and 16mA short circuit at ambient temperature varying between 30-36°C at summer. In fact we can use a dc-dc boost up converter to enlarge the output voltage to meet the requirements of wireless sensor network nodes or its recharging battery. It will be an alternative power source for many portable electronic types of equipment.

  16. Toward Control of Matter: Basic Energy Science Needs for a New Class of X-Ray Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Arenholz, Elke; Belkacem, Ali; Cocke, Lew; Corlett, John; Falcone, Roger; Fischer, Peter; Fleming, Graham; Gessner, Oliver; Hasan, M. Zahid; Hussain, Zahid; Kevan, Steve; Kirz, Janos; McCurdy, Bill; Nelson, Keith; Neumark, Dan; Nilsson, Anders; Siegmann, Hans; Stocks, Malcolm; Schafer, Ken; Schoenlein, Robert; Spence, John; Weber, Thorsten

    2008-09-24

    Over the past quarter century, light-source user facilities have transformed research in areas ranging from gas-phase chemical dynamics to materials characterization. The ever-improving capabilities of these facilities have revolutionized our ability to study the electronic structure and dynamics of atoms, molecules, and even the most complex new materials, to understand catalytic reactions, to visualize magnetic domains, and to solve protein structures. Yet these outstanding facilities still have limitations well understood by their thousands of users. Accordingly, over the past several years, many proposals and conceptual designs for"next-generation" x-ray light sources have been developed around the world. In order to survey the scientific problems that might be addressed specifically by those new light sources operating below a photon energy of about 3 keV and to identify the scientific requirements that should drive the design of such facilities, a workshop"Science for a New Class of Soft X-Ray Light Sources" was held in Berkeley in October 2007. From an analysisof the most compelling scientific questions that could be identified and the experimental requirements for answering them, we set out to define, without regard to the specific technologies upon which they might be based, the capabilities such light sources would have to deliver in order to dramatically advance the state of research in the areas represented in the programs of the Department of Energy's Office of Basic Energy Sciences (BES). This report is based on the workshop presentations and discussions.

  17. Lattice Design for PEP-X Ultimate Storage Ring Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Bane, K.L.F.; Cai, Y.; Nosochkov, Y.; Wang, M.-H.; /SLAC; Hettel, R.O.; /SLAC

    2011-12-13

    SLAC expertise in designing and operating high current storage rings and the availability of the 2.2-km PEP-II tunnel present an opportunity for building a next generation light source - PEP-X - that would replace the SPEAR3 storage ring in the future. The PEP-X 'baseline' design, with 164 pm-rad emittance at 4.5 GeV beam energy and a current of 1.5 A, was completed in 2010. As a next step, a so-called 'ultimate' PEP-X lattice, reducing the emittance to 11 pm-rad at zero current, has been designed. This emittance approaches the diffraction limited photon emittance for multi-keV photons, providing near maximum photon brightness and high coherence. It is achieved by using 7-bend achromat cells in the ring arcs and a 90-m damping wiggler in one of the 6 long straight sections. Details of the lattice design, dynamic aperture, and calculations of the intra-beam scattering effect and Touschek lifetime at a nominal 0.2 A current are presented. Accelerator-based light sources are in high demand for many experimental applications. The availability of the 2.2-km PEP-II tunnel at SLAC presents an opportunity for building a next generation light source - PEP-X - that would replace the existing SPEAR3 light source in the future. The PEP-X study started in 2008, and the 'baseline' design, yielding 164 pm-rad emittance at 4.5 GeV beam energy and a current of 1.5 A, was completed in 2010. This relatively conservative design can be built using existing technology. However, for a long term future, it is natural to investigate a more aggressive, so-called 'ultimate' ring design. The goal is to reduce the electron emittance in both x and y planes to near the diffraction limited photon emittance of 8 pm-rad at hard X-ray photon wavelength of 0.1 nm. This would provide a near maximum photon brightness and significant increase in photon coherence. This study was motivated by the advances in low emittance design at MAX-IV. The latter was used as a

  18. Current-voltage model of LED light sources

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2012-01-01

    Amplitude modulation is rarely used for dimming light-emitting diodes in polychromatic luminaires due to big color shifts caused by varying magnitude of LED driving current and nonlinear relationship between intensity of a diode and driving current. Current-voltage empirical model of light...

  19. Organic Light Emitting Device as a fluorescence spectroscopy's light source : one step towards the lab-on-a-chip device

    Science.gov (United States)

    Camou, S.; Kitamura, M.; Gouy, Jean-Philippe; Fujita, Hiroyuki; Arakawa, Yasuhiko; Fujii, Teruo

    2003-02-01

    Many papers were recently dedicated to the lab-on-a-chip applications, where all the basic elements should be integrated directly onto the microchip. The fluorescence spectroscopy is mostly used as a detection method due to its high reliability and sensitivity, but requires light source and photo-detector. For the first time, we then propose to use Organic material Light Emitting Diode (OLED) to supply a light source for the optical detection based on fluorescence spectroscopy. By combining this OLED with micro-fluidic channels patterned in PDMS layer, the integration of light source on the chip is then achieved. First, the ability of Organic Material to excite fluorescent response from dye is demonstrated. Then, some configurations are described in order to decrease the major drawbacks that have to be solved before applying such kind of devices.

  20. Steady State Microbunching for High Brilliance and High Repetition Rate Storage Ring-Based Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Alex; Ratner, Daniel; /SLAC; Jiao, Yi; /Beijing, Inst. High Energy Phys.

    2012-09-06

    Electron-based light sources have proven to be effective sources of high brilliance, high frequency radiation. Such sources are typically either linac-Free Electron Laser (FEL) or storage ring types. The linac-FEL type has high brilliance (because the beam is microbunched) but low repetition rate. The storage ring type has high repetition rate (rapid beam circulation) but comparatively low brilliance or coherence. We propose to explore the feasibility of a microbunched beam in a storage ring that promises high repetition rate and high brilliance. The steady-state-micro-bunch (SSMB) beam in storage ring could provide CW sources for THz, EUV, or soft X-rays. Several SSMB mechanisms have been suggested recently, and in this report, we review a number of these SSMB concepts as promising directions for high brilliance, high repetition rate light sources of the future. The trick of SSMB lies in the RF system, together with the associated synchrotron beam dynamics, of the storage ring. Considering various different RF arrangements, there could be considered a number of scenarios of the SSMB. In this report, we arrange these scenarios more or less in order of the envisioned degree of technical challenge to the RF system, and not in the chronological order of their original references. Once the stored beam is steady-state microbunched in a storage ring, it passes through a radiator repeatedly every turn (or few turns). The radiator extracts a small fraction of the beam energy as coherent radiation with a wavelength corresponding to the microbunched period of the beam. In contrast to an FEL, this radiator is not needed to generate the microbunching (as required e.g. by SASE FELs or seeded FELs), so the radiator can be comparatively simple and short.

  1. Steady State Microbunching for High Brilliance and High Repetition Rate Storage Ring-Based Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Alex; Ratner, Daniel; /SLAC; Jiao, Yi; /Beijing, Inst. High Energy Phys.

    2012-09-06

    Electron-based light sources have proven to be effective sources of high brilliance, high frequency radiation. Such sources are typically either linac-Free Electron Laser (FEL) or storage ring types. The linac-FEL type has high brilliance (because the beam is microbunched) but low repetition rate. The storage ring type has high repetition rate (rapid beam circulation) but comparatively low brilliance or coherence. We propose to explore the feasibility of a microbunched beam in a storage ring that promises high repetition rate and high brilliance. The steady-state-micro-bunch (SSMB) beam in storage ring could provide CW sources for THz, EUV, or soft X-rays. Several SSMB mechanisms have been suggested recently, and in this report, we review a number of these SSMB concepts as promising directions for high brilliance, high repetition rate light sources of the future. The trick of SSMB lies in the RF system, together with the associated synchrotron beam dynamics, of the storage ring. Considering various different RF arrangements, there could be considered a number of scenarios of the SSMB. In this report, we arrange these scenarios more or less in order of the envisioned degree of technical challenge to the RF system, and not in the chronological order of their original references. Once the stored beam is steady-state microbunched in a storage ring, it passes through a radiator repeatedly every turn (or few turns). The radiator extracts a small fraction of the beam energy as coherent radiation with a wavelength corresponding to the microbunched period of the beam. In contrast to an FEL, this radiator is not needed to generate the microbunching (as required e.g. by SASE FELs or seeded FELs), so the radiator can be comparatively simple and short.

  2. CURRENT STATE OF AUTOMOTIVE LIGHTING EQUIPMENT WITH NON-REPLACEABLE LIGHT SOURCES ON BASIS OF LIGHT-EMITTING DIODE TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    S. Sernov

    2012-01-01

    Full Text Available The paper contains information on the current state of automotive lighting equipment. Different designs of automotive lighting devices, their merits and demerits are described in the paper. The paper includes a substantiation of expediency of developing light-emitting diode lighting and proposes recommendations about optimization of their design.

  3. A new small-package super-continuum light source for optical coherence tomography

    Science.gov (United States)

    Meissner, Sven; Cimalla, Peter; Fischer, Björn; Taudt, Christopher; Baselt, Tobias; Hartmann, Peter; Koch, Edmund

    2013-03-01

    Broadband light sources provide a significant benefit for optical coherence tomography (OCT) imaging concerning the axial resolution. Light sources with bandwidths over 200 nm result in an axial resolution up to 2 microns. Such broad band OCT imaging can be achieved utilizing super continuum (SC) light sources. The main important disadvantage of commercial SC light sources is the overall size and the high costs. Therefore, the use of SC light sources in small OCT setups and applications is limited. We present a new small housing and costeffective light source, which is suitable for OCT imaging. The used light source has dimensions of 110 x 160 x 60 mm and covers a wavelength range from 390 nm up to 2500 nm. The light source was coupled in a dual band OCT system. The light is guided into the interferometer and split in reference and sample beam. The superimposed signal is guided to the spectrometer unit, which consists of two spectrometers. This spectrometer system separates the light. One band centered at 800 nm with a full bandwidth of 176 nm and a second band centered at 1250 nm with a full spectral width of 300 nm was extracted. The 800 nm interference signal is detected by a silicon line scan camera and the 1250 nm signal by an indium gallium arsenide linear image sensor. In this test measurement a plastic foil was used as a sample, which is composed of several plastic film layers. Three dimensional images were acquired simultaneous with the dual band OCT setup. The images were acquired at an A-scan rate of 1 kHz. The 1 kHz A-line rate was chosen because so far the optical power of the light source is not optimal for high speed OCT imaging. The source provides 2 mW in the range of 390 nm to 800 nm and 25 mW in the range from 390 nm to 1650 nm. Furthermore, we coupled the light source by a 50:50 optical fiber coupler, which also reduces the overall optical power of the light source within the OCT setup. Nevertheless, we demonstrated that this new small

  4. Automatic Generation of OWL Ontology from XML Data Source

    CERN Document Server

    Yahia, Nora; Ahmed, AbdelWahab

    2012-01-01

    The eXtensible Markup Language (XML) can be used as data exchange format in different domains. It allows different parties to exchange data by providing common understanding of the basic concepts in the domain. XML covers the syntactic level, but lacks support for reasoning. Ontology can provide a semantic representation of domain knowledge which supports efficient reasoning and expressive power. One of the most popular ontology languages is the Web Ontology Language (OWL). It can represent domain knowledge using classes, properties, axioms and instances for the use in a distributed environment such as the World Wide Web. This paper presents a new method for automatic generation of OWL ontology from XML data sources.

  5. 49 CFR Appendix A to Part 564 - Information To Be Submitted for Replaceable Light Sources

    Science.gov (United States)

    2010-10-01

    ... information required by paragraphs A, B, and C of this section I for light sources using a resistive type... 49 Transportation 6 2010-10-01 2010-10-01 false Information To Be Submitted for Replaceable Light Sources A Appendix A to Part 564 Transportation Other Regulations Relating to Transportation (Continued...

  6. 21 CFR 874.4350 - Ear, nose, and throat fiberoptic light source and carrier.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear, nose, and throat fiberoptic light source and... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4350 Ear, nose, and throat fiberoptic light source and carrier. (a) Identification. An ear, nose, and...

  7. lightsources.org: An Internet Site for Light SourceCommunication

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Art

    2004-10-04

    Research at the world's accelerator- (storage-ring and linac) based light sources is one of the most dynamic and rapidly growing fields of science. It frequently results in direct benefits to society, thereby demonstrating the value of the research with very concrete examples, but this is not widely understood or appreciated outside of the immediate user community. Our growing group of light source communicators from facilities in Europe, Asia, and the Americas, inspired by the Interactions.org Web site created by high-energy (elementary-particle)physics communicators, concluded that a light source community Web site (lightsources.org) would be the best tool for establishing effective collaboration between the communications offices of the world's light sources and to maximize the impact of our efforts. We envision lightsources.org to serve as a one-stop-shopping site for information about all aspects of light sources and the research they make possible. Audiences to be served include science communicators, the press, policymakers, the light source community, the wider scientific community, the science-interested public, and students and educators. Our proposal has been sent to the world's light source facility directors by J. Murray Gibson (APS) and William G. Stirling (ESRF). As a result,light sources.org is now being supported by a growing list of facilities from Europe, North America, and Asia. We hope to launch lightsources.org before the end of 2004.

  8. Investigation of a scanning laser projector as an energy-efficient light source in plant production

    NARCIS (Netherlands)

    Murase, Haruhiko; Helm, van der Bob; Oke, Satoshi

    2015-01-01

    The energy costs for artificial lighting in plant factories are very high, but may be decreased by introducing more efficient light sources. Light absorption in plants takes place in the order of a femtosecond, while the chemical reactions for carbon fixation of 5 milliseconds are limiting the

  9. Optical coupling of flexible microstructured organic light sources for automotive applications

    NARCIS (Netherlands)

    Melpignano, P.; Sinesi, S.; Rotaris, G.; Antonipieri, M.; Cicoira, F.; Loi, M.A.; Muccini, M.; Zamboni, R.; Gale, M.T.; Westenhöfer, S.

    2003-01-01

    In this paper, we report on modelling and processing of customised optical patterns coupled with microstructured large area organic light emitting device (OLED) sources for automotive lighting. Different approaches for the optical control of the light emitted from an OLED are discussed and compared

  10. Transverse coherence properties of X-ray beams in third-generation synchrotron radiation sources

    CERN Document Server

    Geloni, Gianluca; Schneidmiller, Evgeni; Yurkov, Mikhail

    2008-01-01

    This article describes a complete theory of spatial coherence for undulator radiation sources. Current estimations of coherence properties often assume that undulator sources are quasi-homogeneous, like thermal sources, and rely on the application of the van Cittert-Zernike theorem for calculating the degree of transverse coherence. Such assumption is not adequate when treating third generation light sources, because the vertical(geometrical) emittance of the electron beam is comparable or even much smaller than the radiation wavelength in a very wide spectral interval that spans over four orders of magnitude (from 0.1 Angstrom up to 10^3 Angstrom). Sometimes, the so-called Gaussian-Schell model, that is widely used in statistical optics in the description of partially-coherent sources, is applied as an alternative to the quasi-homogeneous model. However, as we will demonstrate, this model fails to properly describe coherent properties of X-ray beams from non-homogeneous undulator sources. As a result, a more...

  11. Potential sustainable energy source: Pheroid™ with incorporated light harvesting materials

    CSIR Research Space (South Africa)

    Smit, Jacoba E

    2010-09-01

    Full Text Available . In the photosynthetic system light energy is absorbed by antenna chlorophylls and this energy is then passed onto a reaction centre chlorophyll molecule where charge separation occurs [1] in less than 100 ps and at about 95% efficiency [2]. It has been shown...-based combinations, which enables the production of small, elastic artificial vesicles, called Pheroid™. Previous work has shown that photosynthetic light harvesting material can be incorporated into the Pheroid™ (Figure 1). Figure 1: Examples of photosynthetic...

  12. Contributions of artificial lighting sources on light pollution in Hong Kong measured through a night sky brightness monitoring network

    CERN Document Server

    Pun, Chun Shing Jason; Leung, Wai Yan; Wong, Chung Fai

    2014-01-01

    Light pollution is a form of environmental degradation in which excessive artificial outdoor lighting, such as street lamps, neon signs, and illuminated signboards, affects the natural environment and the ecosystem. Poorly designed outdoor lighting not only wastes energy, money, and valuable Earth resources, but also robs us of our beautiful night sky. Effects of light pollution on the night sky can be evaluated by the skyglow caused by these artificial lighting sources, through measurements of the night sky brightness (NSB). The Hong Kong Night Sky Brightness Monitoring Network (NSN) was established to monitor in detail the conditions of light pollution in Hong Kong. Monitoring stations were set up throughout the city covering a wide range of urban and rural settings to continuously measure the variations of the NSB. Over 4.6 million night sky measurements were collected from 18 distinct locations between May 2010 and March 2013. This huge dataset, over two thousand times larger than our previous survey, for...

  13. Next-Generation Photon Sources for Grand Challenges in Science and Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-05-01

    The next generation of sustainable energy technologies will revolve around transformational new materials and chemical processes that convert energy efficiently among photons, electrons, and chemical bonds. New materials that tap sunlight, store electricity, or make fuel from splitting water or recycling carbon dioxide will need to be much smarter and more functional than today's commodity-based energy materials. To control and catalyze chemical reactions or to convert a solar photon to an electron requires coordination of multiple steps, each carried out by customized materials and interfaces with designed nanoscale structures. Such advanced materials are not found in nature the way we find fossil fuels; they must be designed and fabricated to exacting standards, using principles revealed by basic science. Success in this endeavor requires probing, and ultimately controlling, the interactions among photons, electrons, and chemical bonds on their natural length and time scales. Control science - the application of knowledge at the frontier of science to control phenomena and create new functionality - realized through the next generation of ultraviolet and X-ray photon sources, has the potential to be transformational for the life sciences and information technology, as well as for sustainable energy. Current synchrotron-based light sources have revolutionized macromolecular crystallography. The insights thus obtained are largely in the domain of static structure. The opportunity is for next generation light sources to extend these insights to the control of dynamic phenomena through ultrafast pump-probe experiments, time-resolved coherent imaging, and high-resolution spectroscopic imaging. Similarly, control of spin and charge degrees of freedom in complex functional materials has the potential not only to reveal the fundamental mechanisms of high-temperature superconductivity, but also to lay the foundation for future generations of information science. This

  14. Paul Scherrer Institute Scientific Report 1998. Volume VII: Swiss Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Weyer, Heinz Josef; Bugmann, Marlen; Neuhaus, Sibylle [eds.

    1999-09-01

    The Swiss Light Source (SLS) is a medium energy range light source that also provides light with high brilliance in the regime of hard X-rays. It is being constructed at PSI and scheduled to be operational in 2001. A series of new features that were adopted for the design and operation of this machine, is described in this annual report for 1998 figs., tabs., refs.

  15. Stable droplet generator for a high brightness laser produced plasma extreme ultraviolet source

    Science.gov (United States)

    Vinokhodov, A.; Krivokorytov, M.; Sidelnikov, Yu.; Krivtsun, V.; Medvedev, V.; Bushuev, V.; Koshelev, K.; Glushkov, D.; Ellwi, S.

    2016-10-01

    We present the results of the low-melting liquid metal droplets generation based on excited Rayleigh jet breakup. We discuss on the operation of the industrial and in-house designed and manufactured dispensing devices for the droplets generation. Droplet diameter can be varied in the range of 30-90 μm. The working frequency of the droplets, velocity, and the operating temperature were in the ranges of 20-150 kHz, 4-15 m/s, and up to 250 °C, respectively. The standard deviations for the droplet center of mass position both their diameter σ < 1 μm at the distance of 45 mm from the nozzle. Stable operation in the long-term (over 1.5 h) was demonstrated for a wide range of the droplet parameters: diameters, frequencies, and velocities. Physical factors affecting the stability of the generator operation have been identified. The technique for droplet synchronization, allowing using the droplet as a target for laser produced plasma, has been created; in particular, the generator has been successfully used in a high brightness extreme ultraviolet (EUV) light source. The operation with frequency up to 8 kHz was demonstrated as a result of the experimental simulation, which can provide an average brightness of the EUV source up to ˜1.2 kW/mm2 sr.

  16. Kinetic study of the hydrocarbon generation from marine carbonate source rocks characterization of products of gas and liquid hydrocarbon

    Institute of Scientific and Technical Information of China (English)

    GENG Xinhua; GENG Ansong; XIONG Yongqiang; LIU Jinzhong; ZHANG Haizu; ZHAO Qingfang

    2006-01-01

    The kinetic parameters of hydrocarbon generation from the marine carbonate source rocks were determined and calibrated through kinetic simulating experiment. The kinetic parameters of hydrocarbon generation then were extrapolated to geological condition by using the relative software.The result shows that gaseous hydrocarbons (C1, C2,C3, C4-5) were generated in condition of 150℃<T<220℃(1.0%<Ro <3.0% ). Light hydrocarbons (C6-13)and heavy hydrocarbons ( C13+) were generated in condition of 100 ℃<T<170 ℃ (0.5%<Ro<1.5%). A quantitative reference to examine the natural evolution of hydrocarbon of marine carbonate source rocks can be established through the results. It also provides a new method for evaluating the highly mature marine carbonate source rock more reasonably.

  17. Status of SPring-8 Photocathode Rf Gun for Future Light Sources

    CERN Document Server

    Tomizawa, H; Dewa, H; Hanaki, H; Kobayashi, T; Mizuno, A; Suzuki, S; Taniuchi, T; Yanagida, K

    2005-01-01

    We have been studying photocathode single-cell pillbox rf gun for future light sources since 1996. We achieved a rmaximum field gradient of 187 MV/m with chemical-etching processed cavity. We have been developed stable and highly qualified UV-laser source for the rf gun intensively last 3 years. The UV-laser pulse (10 Hz) energy is up to 850 uJ/pulse. The energy stability (rms) of laser has been improved down to 0.2~0.3 % at the fundamental and 0.7~1.3% at the third harmonic generation. This stability is held for two months continuously. In this improvement, we just passively stabilized the system in a humidity-controlled clean room. On the other hand, the ideal spatial and temporal profiles of a shot-by-shot single laser pulse are essential to suppress the emittance growth of the electron beam from the rf gun. We prepared a deformable mirror for spatial shaping, and a spatial light modulator based on fused-silica plates for temporal shaping. With a deformable mirror, we obtained an emittance of1.6

  18. Can use of a cold light source in endoscopic middle ear surgery cause sensorineural hearing loss?

    Directory of Open Access Journals (Sweden)

    Suat Terzi

    2016-01-01

    Full Text Available Objectives: To investigate possible sensorineural hearing loss created by the use of a cold light source in patients undergoing endoscopic tympanoplasty surgery. Materials and Methods: The medical records of 203 patients, who underwent endoscopic Type 1 tympanoplasty surgery in our ear, nose, and throat clinic between 2012 and 2015, were checked retrospectively. Ninety-one patients were male and 112 were female, and their mean age was 34.4 ± 11.2 years. Results of audiometric measurements performed during the preoperative period and repeated 1 and 3 months postsurgery were compared to each other. Results: The mean duration of the operations was determined to be 52.4 ± 9.1 min. In addition, average preoperative bone-conduction was 11.4 ± 7.4 dB nHL. However, it was 9.57 ± 7.1 dB nHL and 9.51 ± 7.4 dB nHL, respectively, in the 1st and 3rd postoperative months. Levels of postoperative average bone-conduction at the 1st and 3rd month, as well as the thresholds of bone-conduction at 500, 1000, and 2000 Hz, were significantly lower than the preoperative results (P 0.05. Conclusion: Based on our findings, the increased heat generated by the use of a cold light source during an endoscopic tympanoplasty surgery is unlikely to cause the development of sensorineural hearing loss.

  19. Measurements of Intra-Beam Scattering at Low Emittance in the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Byrd, J.; Corlett, J.; Nishimura, H.; Robin, D.; De Santis, S.; Steier, C.; Wolski, A.; Wu, Y.; /LBL, Berkeley; Bane, K.; Raubenheimer, T.; Ross, M.; Sheppard, J.; Smith,; /SLAC

    2006-03-13

    The beam emittance at the interaction point of linear colliders is expected to be strongly influenced by the emittance of the beams extracted from the damping rings. Intra-beam scattering (IBS) potentially limits the minimum emittance of low-energy storage rings, and this effect strongly influences the choice of energy of damping rings [1]. Theoretical analysis suggests that the NLC damping rings will experience modest emittance growth at 1.98 GeV, however there is little experimental data of IBS effects for very low-emittance machines in the energy regime of interest. The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory is a third-generation synchrotron light source operating with high-intensity, low-emittance beams at energies of approximately 1-2 GeV, and with emittance coupling capability of 1% or less. We present measurements of the beam growth in three dimensions as a function of current, for normalized natural horizontal emittance of approximately 1-10 mm-mrad at energies of 0.7-1.5 GeV, values comparable to the parameters in an NLC damping ring. Using a dedicated diagnostic beamline with an x-ray scintillator imaging system, measurements of the transverse beamsize are made, and bunch length measurements are made using an optical streak camera. Emittance growth as a function of bunch current is determined, and compared with preliminary calculation estimates.

  20. Toward Femtosecond X-ray Spectroscopy at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Chong, Henry Herng Wei

    2004-04-16

    The realization of tunable, ultrashort pulse x-ray sources promises to open new venues of science and to shed new light on long-standing problems in condensed matter physics and chemistry. Fundamentally new information can now be accessed. Used in a pump-probe spectroscopy, ultrashort x-ray pulses provide a means to monitor atomic rearrangement and changes in electronic structure in condensed-matter and chemical systems on the physically-limiting time-scales of atomic motion. This opens the way for the study of fast structural dynamics and the role they play in phase transitions, chemical reactions and the emergence of exotic properties in materials with strongly interacting degrees of freedom. The ultrashort pulse x-ray source developed at the Advanced Light Source at the Lawrence Berkeley Laboratory is based on electron slicing in storage rings, and generates {approx}100 femtosecond pulses of synchrotron radiation spanning wavelengths from the far-infrared to the hard x-ray region of the electromagnetic spectrum. The tunability of the source allows for the adaptation of a broad range of static x-ray spectroscopies to useful pump-probe measurements. Initial experiments are attempted on transition metal complexes that exhibit relatively large structural changes upon photo-excitation and which have excited-state evolution determined by strongly interacting structural, electronic and magnetic degrees of freedom. Specifically, iron(II) complexes undergo a spin-crossover transition upon optical irradiation. The dynamics of the transition involve a metal-to-ligand charge transfer, a {Delta}S=2 change in magnetic moment and 10% bond dilation in the first coordination shell of the iron. Studies of the electronic dynamics are studied with time-resolved optical absorption measurements. The current progress of time-resolved structural studies to complete the picture of the spin-crossover transition is presented.

  1. Toward Femtosecond X-ray Spectroscopy at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Chong, Henry Herng Wei [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    The realization of tunable, ultrashort pulse x-ray sources promises to open new venues of science and to shed new light on long-standing problems in condensed matter physics and chemistry. Fundamentally new information can now be accessed. Used in a pump-probe spectroscopy, ultrashort x-ray pulses provide a means to monitor atomic rearrangement and changes in electronic structure in condensed-matter and chemical systems on the physically-limiting time-scales of atomic motion. This opens the way for the study of fast structural dynamics and the role they play in phase transitions, chemical reactions and the emergence of exotic properties in materials with strongly interacting degrees of freedom. The ultrashort pulse x-ray source developed at the Advanced Light Source at the Lawrence Berkeley Laboratory is based on electron slicing in storage rings, and generates ~100 femtosecond pulses of synchrotron radiation spanning wavelengths from the far-infrared to the hard x-ray region of the electromagnetic spectrum. The tunability of the source allows for the adaptation of a broad range of static x-ray spectroscopies to useful pump-probe measurements. Initial experiments are attempted on transition metal complexes that exhibit relatively large structural changes upon photo-excitation and which have excited-state evolution determined by strongly interacting structural, electronic and magnetic degrees of freedom. Specifically, iron(II) complexes undergo a spin-crossover transition upon optical irradiation. The dynamics of the transition involve a metal-to-ligand charge transfer, a ΔS=2 change in magnetic moment and 10% bond dilation in the first coordination shell of the iron. Studies of the electronic dynamics are studied with time-resolved optical absorption measurements. The current progress of time-resolved structural studies to complete the picture of the spin-crossover transition is presented.

  2. National synchrotron light source in the infra-red region

    Energy Technology Data Exchange (ETDEWEB)

    Williams, G.P.

    1981-01-01

    A discussion of the utilization of the NSLS in the 1 to 100 micron infra-red spectral region is presented. A comparison is made of the respective brightnesses of the NSLS and of black-body sources. The way in which each source may be utilized with a monochromator is discussed and comparative exit slit brightnesses are calculated for selected cases.

  3. Generation of isolated asymmetric umbilics in light's polarization

    CERN Document Server

    Galvez, Enrique J; Kumar, Vijay; Viswanathan, Nirmal K

    2014-01-01

    Polarization-singularity C-points, a form of line singularities, are the vectorial counterparts of the optical vortices of spatial modes and fundamental optical features of polarization-spatial modes. Their generation in tailored beams has been limited to lemon and star C-points that contain symmetric dislocations in state-of-polarization patterns. In this article we present the theory and laboratory measurements of two complementary methods to generate isolated asymmetric C-points in tailored beams, of which symmetric lemons and stars are limiting cases; and we report on the generation of monstars, an asymmetric C-point with characteristics of both lemons and stars.

  4. Light intensity and quality from sole-source light-emitting diodes impact growth, morphology, and nutrient content of Brassica microgreens

    Science.gov (United States)

    Multi-layer vertical production systems using sole-source (SS) lighting can be used for microgreen production; however, traditional SS lighting can consume large amounts of electrical energy. Light-emitting diodes (LEDs) offer many advantages over conventional light sources including: high photoelec...

  5. Generation of Attosecond Light Pulses from Gas and Solid State Media

    Directory of Open Access Journals (Sweden)

    Stefanos Chatziathanasiou

    2017-03-01

    Full Text Available Real-time observation of ultrafast dynamics in the microcosm is a fundamental approach for understanding the internal evolution of physical, chemical and biological systems. Tools for tracing such dynamics are flashes of light with duration comparable to or shorter than the characteristic evolution times of the system under investigation. While femtosecond (fs pulses are successfully used to investigate vibrational dynamics in molecular systems, real time observation of electron motion in all states of matter requires temporal resolution in the attosecond (1 attosecond (asec = 10−18 s time scale. During the last decades, continuous efforts in ultra-short pulse engineering led to the development of table-top sources which can produce asec pulses. These pulses have been synthesized by using broadband coherent radiation in the extreme ultraviolet (XUV spectral region generated by the interaction of matter with intense fs pulses. Here, we will review asec pulses generated by the interaction of gas phase media and solid surfaces with intense fs IR laser fields. After a brief overview of the fundamental process underlying the XUV emission form these media, we will review the current technology, specifications and the ongoing developments of such asec sources.

  6. Influence of light sources on the migration of polymorphonuclear leukocytes

    Science.gov (United States)

    DellaVecchia, Michael A.; Beard, Richard B.; Dai, Xiaoyan

    1995-05-01

    In the process of inflammation, leukocytes must travel from the intraluminal space of the capillary to the interstitial space in order to reach the site of the inflammation. The two major populations of mature human leukocytes based on the morphology are the polymorphonuclear leukocytes (PMN), and mononuclear leukocytes (MNL). Previous research on PMNs and MNLs at the Biomedical Engineering and Science Institute of Drexel University have shown that their migration can be markedly enhanced by excitation with electric and magnetic fields. This presentation demonstrates that the migration of PMNs under excitation of photons is enhanced in the red light region of (lambda) equals 660 nm and inhibited in the green light region of (lambda) equals 565 nm. There is an intensity threshold at which red light enhances migration and an intensity threshold at which green light inhibits migration. In these experiments the Boyden technique was used with the distance of the cell migration through a cellulose filter measured in terms of the leading edge. The comparison of the relative value of the distance to cell migration under a light to cell migration without a light stimulus was recorded as a cytokinetic index, K.I.. K.I. is a measure of the cytokinesis which is the progress of the cell movement in which the migration is enhanced by substances in the cell environment irrespective of a concentration gradient. The cytotactic index is a measure of cytotaxis which is the directional movement along a chemical gradient formed by a chemotactic factor. A Russian pulsed commercial laser biostimulator in the near infrared wavelength above an intensity threshold enhances PMN migration. Intermittent green and red stimulators below the intensity threshold markedly influence the cytokinetic index of PMNs while above the intensity threshold, this influence is deminished.

  7. Generation of Antibunched Light by Excited Molecules in a Microcavity Trap

    Science.gov (United States)

    DeMartini, F.; DiGiuseppe, G.; Marrocco, M.

    1996-01-01

    The active microcavity is adopted as an efficient source of non-classical light. By this device, excited by a mode-locked laser at a rate of 100 MHz, single-photons are generated over a single field mode with a nonclassical sub-poissonian distribution. The process of adiabatic recycling within a multi-step Franck-Condon molecular optical-pumping mechanism, characterized in our case by a quantum efficiency very close to one, implies a pump self-regularization process leading to a striking n-squeezing effect. By a replication of the basic single-atom excitation process a beam of quantum photon (Fock states) can be created. The new process represents a significant advance in the modern fields of basic quantum-mechanical investigation, quantum communication and quantum cryptography.

  8. Superconducting light generator for large offshore wind turbines

    Science.gov (United States)

    Sanz, S.; Arlaban, T.; Manzanas, R.; Tropeano, M.; Funke, R.; Kováč, P.; Yang, Y.; Neumann, H.; Mondesert, B.

    2014-05-01

    Offshore wind market demands higher power rate and reliable turbines in order to optimize capital and operational cost. These requests are difficult to overcome with conventional generator technologies due to a significant weight and cost increase with the scaling up. Thus superconducting materials appears as a prominent solution for wind generators, based on their capacity to held high current densities with very small losses, which permits to efficiently replace copper conductors mainly in the rotor field coils. However the state-of-the-art superconducting generator concepts still seem to be expensive and technically challenging for the marine environment. This paper describes a 10 MW class novel direct drive superconducting generator, based on MgB2 wires and a modular cryogen free cooling system, which has been specifically designed for the offshore wind industry needs.

  9. Squeezed light from second-harmonic generation: experiment versus theory.

    Science.gov (United States)

    Ralph, T C; Taubman, M S; White, A G; McClelland, D E; Bachor, H A

    1995-06-01

    We report excellent quantitative agreement between theoretical predictions and experimental observation of squeezing from a singly resonant second-harmonic-generating crystal. Limitations in the noise suppression imposed by the pump laser are explicitly modeled and confirmed by our measurements.

  10. Mono-energy coronary angiography with a compact light source

    Science.gov (United States)

    Eggl, Elena; Mechlem, Korbinian; Braig, Eva; Kulpe, Stephanie; Dierolf, Martin; Günther, Benedikt; Achterhold, Klaus; Herzen, Julia; Gleich, Bernhard; Rummeny, Ernst; Noël, Peter B.; Pfeiffer, Franz; Muenzel, Daniela

    2017-03-01

    While conventional x-ray tube sources reliably provide high-power x-ray beams for everyday clinical practice, the broad spectra that are inherent to these sources compromise the diagnostic image quality. For a monochromatic x-ray source on the other hand, the x-ray energy can be adjusted to optimal conditions with respect to contrast and dose. However, large-scale synchrotron sources impose high spatial and financial demands, making them unsuitable for clinical practice. During the last decades, research has brought up compact synchrotron sources based on inverse Compton scattering, which deliver a highly brilliant, quasi-monochromatic, tunable x-ray beam, yet fitting into a standard laboratory. One application that could benefit from the invention of these sources in clinical practice is coronary angiography. Being an important and frequently applied diagnostic tool, a high number of complications in angiography, such as renal failure, allergic reaction, or hyperthyroidism, are caused by the large amount of iodine-based contrast agent that is required for achieving sufficient image contrast. Here we demonstrate monochromatic angiography of a porcine heart acquired at the MuCLS, the first compact synchrotron source. By means of a simulation, the CNR in a coronary angiography image achieved with the quasi-mono-energetic MuCLS spectrum is analyzed and compared to a conventional x-ray-tube spectrum. The results imply that the improved CNR achieved with a quasi-monochromatic spectrum can allow for a significant reduction of iodine contrast material.

  11. Artificial algae algorithm with multi-light source for numerical optimization and applications.

    Science.gov (United States)

    Uymaz, Sait Ali; Tezel, Gulay; Yel, Esra

    2015-12-01

    Artificial algae algorithm (AAA), which is one of the recently developed bio-inspired optimization algorithms, has been introduced by inspiration from living behaviors of microalgae. In AAA, the modification of the algal colonies, i.e. exploration and exploitation is provided with a helical movement. In this study, AAA was modified by implementing multi-light source movement and artificial algae algorithm with multi-light source (AAAML) version was established. In this new version, we propose the selection of a different light source for each dimension that is modified with the helical movement for stronger balance between exploration and exploitation. These light sources have been selected by tournament method and each light source are different from each other. This gives different solutions in the search space. The best of these three light sources provides orientation to the better region of search space. Furthermore, the diversity in the source space is obtained with the worst light source. In addition, the other light source improves the balance. To indicate the performance of AAA with new proposed operators (AAAML), experiments were performed on two different sets. Firstly, the performance of AAA and AAAML was evaluated on the IEEE-CEC'13 benchmark set. The second set was real-world optimization problems used in the IEEE-CEC'11. To verify the effectiveness and efficiency of the proposed algorithm, the results were compared with other state-of-the-art hybrid and modified algorithms. Experimental results showed that the multi-light source movement (MLS) increases the success of the AAA.

  12. Using Nonuniform Fiber to Generate Slow Light via SBS

    Directory of Open Access Journals (Sweden)

    Wenhai Li

    2008-01-01

    Full Text Available The data pulse delay based on slow light induced by stimulated Brillouin scattering (SBS in a nonuniform dispersion decreasing fiber (DDF is demonstrated experimentally, and the distortions of data pulses at different beat frequencies are studied. We found that a delay exceeding a pulse width can be achieved at particular beat frequency, and the DDF has larger delay versus gain slope coefficient with much better output pulse quality than single-mode fiber.

  13. Lasers or light sources for treating port-wine stains

    DEFF Research Database (Denmark)

    Faurschou, Annesofie; Olesen, Anne Braae; Leonardi-Bee, Jo;

    2011-01-01

    Port-wine stains are birthmarks caused by malformations of blood vessels in the skin. Port-wine stains manifest themselves in infancy as a flat, red mark and do not regress spontaneously but may, if untreated, become darker and thicker in adult life. The profusion of various lasers and light...

  14. Microwave Oven Experiments with Metals and Light Sources

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter; Karstadt, Detlef

    2004-01-01

    "Don't put metal objects in the microwave" is common safety advice. But why? Here we describe demonstration experiments involving placing household metallic objects in a microwave oven. These allow a better understanding of the interaction of microwaves with materials. Light bulbs and discharge lamps can also be used in instructive demonstrations.

  15. Microwave Oven Experiments with Metals and Light Sources

    Science.gov (United States)

    Vollmer, Michael; Mollmann, Klaus-Peter; Karstadt, Detlef

    2004-01-01

    "Don't put metal objects in the microwave" is common safety advice. But why? Here we describe demonstration experiments involving placing household metallic objects in a microwave oven. These allow a better understanding of the interaction of microwaves with materials. Light bulbs and discharge lamps can also be used in instructive demonstrations.

  16. Investigation of runoff generation from anthropogenic sources with dissolved xenobiotics

    Science.gov (United States)

    Krein, A.; Pailler, J.; Guignard, C.; Iffly, J.; Pfister, L.; Hoffmann, L.

    2009-04-01

    In the experimental Mess basin (35 km2, Luxembourg) dissolved xenobiotics in surface water are used to study the influences of anthropogenic sources like separated sewer systems on runoff generation. Emerging contaminants like pharmaceuticals are of growing interest because of their use in large quantities in human and veterinary medicine. The amounts reaching surface waters depend on rainfall patterns, hydraulic conditions, consumption, metabolism, degradation, and disposal. The behaviour of endocrine disruptors including pharmaceuticals in the aquatic environment is widely unknown. The twelve molecules analyzed belong to three families: the estrogens, the antibiotics (sulfonamides, tetracyclines), and the painkillers (ibuprofen, diclofenac). Xenobiotics can be used as potential environmental tracers for untreated sewerage. Our results show that the concentrations are highly variable during flood events. The highest concentrations are reached in the first flush period, mainly during the rising limb of the flood hydrographs. As a result of the kinematic wave effect the concentration peak occurs in some cases a few hours after the discharge maximum. In floodwater (eleven floods, 66 samples) the highest concentrations were measured for ibuprofen (g/l range), estrone, and diclofenac (all ng/l range). From the tetracycline group, essentially tetracycline itself is of relevance, while the sulfonamides are mainly represented by sulfamethoxazole (all in ng/l range). In the Mess River the pharmaceuticals fluxes during flood events proved to be influenced by hydrological conditions. Different pharmaceuticals showed their concentration peaks during different times of a flood event. An example is the estrone peak that - during summer flash floods - often occurred one to two hours prior to the largest concentrations of the painkillers. This suggests for more sources than the sole storm drainage through the spillway of the single sewage water treatment plant, different

  17. Playing the tricks of numbers of light sources

    Science.gov (United States)

    Chen, Huanyang; Xu, Yadong; Li, Hui; Tyc, Tomáš

    2013-09-01

    Transformation optics has demonstrated its ability to design various novel devices, for example, to change objects' sizes, positions or even shapes. This time we come to another magical manipulation: to change the numbers of sources. In this paper, we will design a new class of gradient index lenses from multivalued optical conformal mapping. We shall call them the conformal lenses. Such lenses can make one active source appear omnidirectionally as two (or many) in-phase sources, each interfering with others. As a self-interference phenomenon, this has not been discussed before. Meanwhile, they can transform multiple in-phase sources into one. Other intriguing illusion effects are also demonstrated. Based on the Riemann sheet analysis, the physics mechanism of such effects are well explained. Finally, we apply transmutation methods to design lenses without any singular material parameters.

  18. White-light generation control with crossing beams of femtosecond laser pulses.

    Science.gov (United States)

    Kolomenskii, A A; Strohaber, J; Kaya, N; Kaya, G; Sokolov, A V; Schuessler, H A

    2016-01-11

    We investigated the variations in generated white-light when crossing two femtosecond laser beams in a Kerr medium. By changing the relative delay of two interacting intense femtosecond laser pulses, we show that white-light generation can be enhanced or suppressed. With a decrease of the relative delay an enhancement of the white-light output was observed, which at even smaller delays was reverted to a suppression of white-light generation. Under choosen conditions, the level of suppression resulted in a white-light output lower than the initial level corresponding to large delays, when the pulses do not overlap in time. The enhancement of the white-light generation takes place in the pulse that is lagging. We found that the effect of the interaction of the beams depends on their relative orientation of polarization and increases when the polarizations are changed from perpendicular to parallel. The observed effects are explained by noting that at intermediate delays, the perturbations introduced in the path of the lagging beam lead to a shortening of the length of filament formation and enhancement of the white-light generation, whereas at small delays the stronger interaction and mutual rescattering reduces the intensity in the central part of the beams, suppressing filamentation and white-light generation.

  19. White LED compared with other light sources: age-dependent photobiological effects and parameters for evaluation.

    Science.gov (United States)

    Rebec, Katja Malovrh; Klanjšek-Gunde, Marta; Bizjak, Grega; Kobav, Matej B

    2015-01-01

    Ergonomic science at work and living places should appraise human factors concerning the photobiological effects of lighting. Thorough knowledge on this subject has been gained in the past; however, few attempts have been made to propose suitable evaluation parameters. The blue light hazard and its influence on melatonin secretion in age-dependent observers is considered in this paper and parameters for its evaluation are proposed. New parameters were applied to analyse the effects of white light-emitting diode (LED) light sources and to compare them with the currently applied light sources. The photobiological effects of light sources with the same illuminance but different spectral power distribution were determined for healthy 4-76-year-old observers. The suitability of new parameters is discussed. Correlated colour temperature, the only parameter currently used to assess photobiological effects, is evaluated and compared to new parameters.

  20. Modelling of a laser-pumped light source for endoscopic surgery

    Science.gov (United States)

    Nadeau, Valerie J.; Elson, Daniel S.; Hanna, George B.; Neil, Mark A. A.

    2008-09-01

    A white light source, based on illumination of a yellow phosphor with a fibre-coupled blue-violet diode laser, has been designed and built for use in endoscopic surgery. This narrow light probe can be integrated into a standard laparoscope or inserted into the patient separately via a needle. We present a Monte Carlo model of light scattering and phosphorescence within the phosphor/silicone matrix at the probe tip, and measurements of the colour, intensity, and uniformity of the illumination. Images obtained under illumination with this light source are also presented, demonstrating the improvement in illumination quality over existing endoscopic light sources. This new approach to endoscopic lighting has the advantages of compact design, improved ergonomics, and more uniform illumination in comparison with current technologies.

  1. Effect of color temperature of light sources on slow-wave sleep.

    Science.gov (United States)

    Kozaki, Tomoaki; Kitamura, Shingo; Higashihara, Yuichi; Ishibashi, Keita; Noguchi, Hiroki; Yasukouchi, Akira

    2005-03-01

    In order to examine whether the spectral compositions of light source may affect sleep quality, sleep architecture under different color temperatures of light sources was evaluated. Seven healthy males were exposed to the light sources of different color temperatures (3000 K, 5000 K and 6700 K) for 6.5 h before sleep. The horizontal illuminance level was kept at 1000 lux. Subjects slept on a bed in near darkness (light, and polysomnograms recorded the sleep parameters. In the early phase of the sleep period, the amount of stage-4 sleep (S4-sleep) was significantly attenuated under the higher color temperature of 6700 K compared with the lower color temperature of 3000 K. Present findings suggest that light sources with higher color temperatures may affect sleep quality in a view that S4-sleep period is important for sleep quality.

  2. Illuminating Solar Decathlon Homes: Exploring Next Generation Lighting Technology - Light Emitting Diodes

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Kelly L.; Gilbride, Theresa L.

    2008-05-22

    This report was prepared by PNNL for the US Department of Energy Building Technologies Program, Solid-State Lighting Program. The report will be provided to teams of university students who are building houses for the 2009 Solar Decathlon, a home design competition sponsored in part by DOE, to encourage teams to build totally solar powered homes. One aspect of the competition is lighting. This report provides the teams with information about LED lighting that can help them determine how they incorporate LED lighting into their homes. The report provides an overview of LED technology, a status of where LED technology is today, questions and answers about lighting quality, efficiency, lifetime etc.; numerous examples of LED products; and several weblinks for further research.

  3. A closed-loop photon beam control study for the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Portmann, G.; Bengtsson, J.

    1993-05-01

    The third generation Advanced Light Source (ALS) will produce extremely bright photon beams using undulators and wigglers. In order to position the photon beams accurate to the micron level, a closed-loop feedback system is being developed. Using photon position monitors and dipole corrector magnets, a closed-loop system can automatically compensate for modeling uncertainties and exogenous disturbances. The following paper will present a dynamics model for the perturbations of the closed orbit of the electron beam in the ALS storage ring including the vacuum chamber magnetic field penetration effects. Using this reference model, two closed-loop feedback algorithms will be compared -- a classical PI controller and a two degree-of-freedom approach. The two degree-of-freedom method provides superior disturbance rejection while maintaining the desired performance goals. Both methods will address the need to gain schedule the controller due to the time varying dynamics introduced by changing field strengths when scanning the insertion devices.

  4. Fast Mapping of Terahertz Bursting Thresholds and Characteristics at Synchrotron Light Sources

    CERN Document Server

    Brosi, Miriam; Blomley, Edmund; Bründermann, Erik; Caselle, Michele; Hiller, Nicole; Kehrer, Benjamin; Nasse, Michael J; Rota, Lorenzo; Schedler, Manuel; Schönfeldt, Patrik; Schuh, Marcel; Schwarz, Markus; Weber, Marc; Müller, Anke-Susanne

    2016-01-01

    Dedicated optics with extremely short electron bunches enable synchrotron light sources to generate intense coherent THz radiation. The high degree of spatial compression in this so-called low-alpha optics entails a complex longitudinal dynamics of the electron bunches, which can be probed studying the fluctuations in the emitted terahertz radiation caused by the micro-bunching instability ("bursting"). This article presents a "quasi-instantaneous" method for measuring the bursting characteristics by simultaneously collecting and evaluating the information from all bunches in a multi-bunch fill, reducing the measurement time from hours to seconds. This speed-up allows systematic studies of the bursting characteristics for various accelerator settings within a single fill of the machine, enabling a comprehensive comparison of the measured bursting thresholds with theoretical predictions by the bunched-beam theory. This paper introduces the method and presents first results obtained at the ANKA synchrotron radi...

  5. Improved nonlinear optimization in the storage ring of the modern synchrotron radiation light source

    Institute of Scientific and Technical Information of China (English)

    TIAN Shun-Qiang; LIU Gui-Min; HOU Jie; CHEN Guang-Ling; CHEN Sen-Yu

    2009-01-01

    In the storage ring of the third generation light sources,nonlinear optimization is an indispensable course in order to obtain ample dynamic acceptances and to reach high injection efficiency and long beam lifetime,especially in a low emittance lattice.An improved optimization algorithm based on the single resonance approach,which takes relative weight and initial Harmonic Sextupole Integral Strength (HSIS) as search variables,is discussed in this paper.Applications of the improved method in several test lattices are presented.Detailed analysis of the storage ring of the Shanghai Synchrotron Radiation Facility (SSRF) is particularly emphasized.Furthermore,cancellation of the driving terms is investigated to reveal the physical mechanism of the harmonic sextupole compensation.Sensitivity to the weight and the initial HSIS as well as dependence of the optimum solution on the convergent factor is analyzed.

  6. Fast mapping of terahertz bursting thresholds and characteristics at synchrotron light sources

    Directory of Open Access Journals (Sweden)

    Miriam Brosi

    2016-11-01

    Full Text Available Dedicated optics with extremely short electron bunches enable synchrotron light sources to generate intense coherent THz radiation. The high degree of spatial compression in this so-called low-α_{c} optics entails a complex longitudinal dynamics of the electron bunches, which can be probed studying the fluctuations in the emitted terahertz radiation caused by the microbunching instability (“bursting”. This article presents a “quasi-instantaneous” method for measuring the bursting characteristics by simultaneously collecting and evaluating the information from all bunches in a multibunch fill, reducing the measurement time from hours to seconds. This speed-up allows systematic studies of the bursting characteristics for various accelerator settings within a single fill of the machine, enabling a comprehensive comparison of the measured bursting thresholds with theoretical predictions by the bunched-beam theory. This paper introduces the method and presents first results obtained at the ANKA synchrotron radiation facility.

  7. The effects of the insertion devices at the VSX light source

    CERN Document Server

    Harada, K; Takaki, H; Koseki, T; Nakamura, N; Kamiya, Yu

    2001-01-01

    The VSX ring is a third-generation VUV and soft X-ray light source, which has 0.75 nm rad emittance for the ultra-low emittance mode at 1.0 GeV and 5.6 nm rad emittance for the low emittance mode at 1.6 GeV. The ring has about 250 m circumference and twelve straight sections, two of which are 29 m, four 5.4 m, four 2.3 m and two 2 m. The insertion devices to be installed are a 27 m long undulator, three 5 m undulators, a 4 m undulator, a multipole wiggler, two minipole undulators and a superconducting wiggler. We studied the linear effects of these devices. In addition, we studied the nonlinear effects of 27 m undulator because this undulator has the most dominant nonlinear effects on the beam among all the undulators.

  8. INTELLECTUAL CAPITAL AS A GENERATING SOURCE OF MODERNIZATION AND INNOVATION

    Directory of Open Access Journals (Sweden)

    Bazikov A. A.

    2015-05-01

    Full Text Available The article substantiates the idea that intellectual capital while forming is aimed to the implementation of upgrades and innovations to the work of economic entities to actively improve their performance. Source for intellectual capital is labor, which is based on knowledge, skill and professionalism, and later it "turns" individuals into creative individual work. This work, incarnating in any reasonable ideas or technical development, confirms thereby generating the essence of intellectual capital. Its performance becomes visible if the virtual creative ideas are realized in practice. From this perspective, it is important to know that the formation of intellectual capital depends on the directed activities of employees in areas where they would carry it out, and classification of organizational and legal structures of business entities, but also on favorable conditions for productive creativity. In this regard, it is important to adequately assess the costs created by the new product, the share of the money earned therein by a specific intellectual capital worker. As a variant it is proposed to carry out these calculations using the practice of charging interest in the banking business

  9. High-Efficiency Nitride-Base Photonic Crystal Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    James Speck; Evelyn Hu; Claude Weisbuch; Yong-Seok Choi; Kelly McGroddy; Gregor Koblmuller; Elison Matioli; Elizabeth Rangel; Fabian Rol; Dobri Simeonov

    2010-01-31

    The research activities performed in the framework of this project represent a major breakthrough in the demonstration of Photonic Crystals (PhC) as a competitive technology for LEDs with high light extraction efficiency. The goals of the project were to explore the viable approaches to manufacturability of PhC LEDS through proven standard industrial processes, establish the limits of light extraction by various concepts of PhC LEDs, and determine the possible advantages of PhC LEDs over current and forthcoming LED extraction concepts. We have developed three very different geometries for PhC light extraction in LEDs. In addition, we have demonstrated reliable methods for their in-depth analysis allowing the extraction of important parameters such as light extraction efficiency, modal extraction length, directionality, internal and external quantum efficiency. The information gained allows better understanding of the physical processes and the effect of the design parameters on the light directionality and extraction efficiency. As a result, we produced LEDs with controllable emission directionality and a state of the art extraction efficiency that goes up to 94%. Those devices are based on embedded air-gap PhC - a novel technology concept developed in the framework of this project. They rely on a simple and planar fabrication process that is very interesting for industrial implementation due to its robustness and scalability. In fact, besides the additional patterning and regrowth steps, the process is identical as that for standard industrially used p-side-up LEDs. The final devices exhibit the same good electrical characteristics and high process yield as a series of test standard LEDs obtained in comparable conditions. Finally, the technology of embedded air-gap patterns (PhC) has significant potential in other related fields such as: increasing the optical mode interaction with the active region in semiconductor lasers; increasing the coupling of the incident

  10. Installation and Commissioning of a 6-Tesla Superconducting Wavelength Shifter at Taiwan Light Source

    Science.gov (United States)

    Chang, C. H.; Chang, H. P.; Chen, Jenny; Chen, J. R.; Fan, T. C.; Hwang, C. S.; Hsiung, G. Y.; Hsu, K. T.; Kuo, C. C.; Luo, G. H.; Wang, D. J.; Wang, M. H.

    2005-09-01

    The Taiwan Light Source (TLS) is the first third-generation light source in Asia. The storage ring has six straight sections one section for injection, one for the RF cavities and diagnostic instrumentation and four sections for insertion devices, which are U5, U9, EPU and W20. Generating high-energy X-ray photons is a high priority at TLS. A single hybrid type wiggler is associated with three beam lines to serve X-ray users. The installed Superconducting Wavelength Shifter (SWLS) is very compact in size and can produce very high-energy photons. The injection section at TLS can barely accommodate the SWLS. The expected multipole components of the SWLS are strong, shrink the dynamic aperture; perturb the beta function, and reduce the beam lifetime. The increase in the synchrotron radiation by the SWLS also changes beam emittance and increases the energy spread. The influence of SWLS on the low-energy, 1.5 GeV, storage-ring should not be neglected. The downstream kicker with the water-cooled copper mask must be modified to prevent a potential meltdown of the welding junction of the ceramic chamber because the heat load is high. The 1.2 μs half-sine pulse field of the kicker is then altered by the copper-made radiation mask, which is installed inside the ceramic chamber. The operating capability of cryogenic system is established to ensure the smooth commissioning of the SWLS. The magnetic field mapping, the dynamic aperture simulation data and commissioning results will be presented and discussed herein.

  11. High-power multi-megahertz source of waveform-stabilized few-cycle light.

    Science.gov (United States)

    Pronin, O; Seidel, M; Lücking, F; Brons, J; Fedulova, E; Trubetskov, M; Pervak, V; Apolonski, A; Udem, Th; Krausz, F

    2015-05-05

    Waveform-stabilized laser pulses have revolutionized the exploration of the electronic structure and dynamics of matter by serving as the technological basis for frequency-comb and attosecond spectroscopy. Their primary sources, mode-locked titanium-doped sapphire lasers and erbium/ytterbium-doped fibre lasers, deliver pulses with several nanojoules energy, which is insufficient for many important applications. Here we present the waveform-stabilized light source that is scalable to microjoule energy levels at the full (megahertz) repetition rate of the laser oscillator. A diode-pumped Kerr-lens-mode-locked Yb:YAG thin-disk laser combined with extracavity pulse compression yields waveform-stabilized few-cycle pulses (7.7 fs, 2.2 cycles) with a pulse energy of 0.15 μJ and an average power of 6 W. The demonstrated concept is scalable to pulse energies of several microjoules and near-gigawatt peak powers. The generation of attosecond pulses at the full repetition rate of the oscillator comes into reach. The presented system could serve as a primary source for frequency combs in the mid infrared and vacuum UV with unprecedented high power levels.

  12. 3D computer generated medical holograms using spatial light modulators

    OpenAIRE

    Ahmed Sheet; Mai El Sayed; Mai Maged; Mona Ismail; Mariam Ali; Nahed Hussien Solouma; Tarek Abdel-Mottleb

    2014-01-01

    The aim of this work is to electronically generate the diffraction patterns of medical images and then trying to optically reconstruct the corresponding holographs to be displayed in space. This method is proposed in a trial to find a smart alternative of the expensive and perishable recording plates.

  13. Optical-Fiber Fluorosensors With Polarized Light Sources

    Science.gov (United States)

    Egalon, Claudio O.; Rogowski, Robert S.

    1995-01-01

    Chemiluminescent and/or fluorescent molecules in optical-fiber fluorosensors oriented with light-emitting dipoles along transverse axis. Sensor of proposed type captures greater fraction of chemiluminescence or fluorescence and transmits it to photodetector. Transverse polarization increases sensitivity. Basic principles of optical-fiber fluorosensors described in "Making Optical-Fiber Chemical Sensors More Sensitive" (LAR-14525), "Improved Optical-Fiber Chemical Sensors" (LAR-14607), and "Improved Optical-Fiber Temperature Sensors" (LAR-14647).

  14. Optical-Fiber Fluorosensors With Polarized Light Sources

    Science.gov (United States)

    Egalon, Claudio O.; Rogowski, Robert S.

    1995-01-01

    Chemiluminescent and/or fluorescent molecules in optical-fiber fluorosensors oriented with light-emitting dipoles along transverse axis. Sensor of proposed type captures greater fraction of chemiluminescence or fluorescence and transmits it to photodetector. Transverse polarization increases sensitivity. Basic principles of optical-fiber fluorosensors described in "Making Optical-Fiber Chemical Sensors More Sensitive" (LAR-14525), "Improved Optical-Fiber Chemical Sensors" (LAR-14607), and "Improved Optical-Fiber Temperature Sensors" (LAR-14647).

  15. Generation of Short X-Ray Pulses Using Crab Cavities at the Advanced Photon Source

    CERN Document Server

    Harkay, Katherine C; Chae, Yong-Chul; Decker, Glenn; Dejus, Roger J; Emery, Louis; Guo, Weiming; Horan, Douglas; Kim, Kwang-Je; Kustom, Robert; Mills, Dennis M; Milton, Stephen; Pile, Geoffery; Sajaev, Vadim; Shastri, Sarvjit D; Waldschmidt, Geoff J; White, Marion; Yang Bing Xin; Zholents, Alexander

    2005-01-01

    There is growing interest within the user community to utilize the pulsed nature of synchrotron radiation from storage ring sources. Conventional third-generation light sources can provide pulses on the order of 100 ps but typically cannot provide pulses of about 1 ps that some users now require to advance their research programs. However, it was recently proposed by A. Zholents et al. to use rf orbit deflection to generate subpicosecond X-ray pulses.* In this scheme, two crab cavities are used to deliver a longitudinally dependent vertical kick to the beam, thus exciting longitudinally correlated vertical motion of the electrons. This makes it possible to spatially separate the radiation coming from different longitudinal parts of the beam. An optical slit can then be used to slice out a short part of the radiation pulse, or an asymetrically cut crystal can be used to compress the radiation in time. In this paper, we present a feasibility study of this method applied to the Advanced Photon Source. We find th...

  16. User evaluation of eight led light sources with different special colour rendering indices R9

    DEFF Research Database (Denmark)

    Markvart, Jakob; Iversen, Anne; Logadottir, Asta

    2013-01-01

    In this study we evaluated the influence of the special colour rendering index R9 on subjective red colour perception and Caucasian skin appearance among untrained test subjects. The light sources tested are commercially available LED based light sources with similar correlated colour temperature...... and general colour rendering index, but with varying R9. It was found that the test subjects in general are more positive towards light sources with higher R9. The shift from a majority of negative responses to a majority of positive responses is found to occur at R9 values of ~20....

  17. USER EVALUATION OF EIGHT LED LIGHT SOURCES WITH DIFFERENTSPECIAL COLOUR RENDERING INDICES R9

    DEFF Research Database (Denmark)

    Markvart, Jakob; Iversen, Anne; Logadóttir, Ásta;

    2013-01-01

    In this study we evaluated the influence of the special colour rendering index R9 on subjective red colour perception and Caucasian skin appearance among untrained test subjects. The light sources tested are commercially available LED based light sources with similar correlated colour temperature...... and general colour rendering index, but with varying R9. It was found that the test subjects in general are more positive towards light sources with higher R9. The shift from a majority of negative responses to a majority of positive responses is found to occur at R9 values of ~20....

  18. Inner Radiation Belt Generation of Light Nuclei Isotope

    Science.gov (United States)

    Galper, A. M.; Koldashov, S. V.; Leonv, A. A.; Mikhailov, V. V.

    2003-07-01

    Nuclear interactions between inner zone protons and atoms in the upper atmosphere provide the essential source of H and He isotop es nuclei in radiation belt. This paper reports the calculations of these isotop es intensities from the inner zone proton intensity model AP-8, the atmosphere drift-averaged composition and densities model MSIS-90, and cross sections for the various interaction processes. To calculate drift-averaged densities and energy losses of secondaries the particles are traced in geomagnetic field according IGRF-95 model by numerical solution of motion equation. The calculations account for nuclear interactions kinematic along the whole trapped protons trajectories. The results of calculations are compared with experimental data from SAMPEX, CRRES, RESURS-04 and MITA satellites taken during different solar activity phases. The comparison with observational data shows that the atmosphere is sufficient source for inner zone 4 He, 3 He,2 H and 3 H for L-shell less than 1.3.

  19. 2 nm continuously tunable 488nm micro-integrated diode-laser-based SHG light source for Raman spectroscopy

    Science.gov (United States)

    Braune, M.; Maiwald, M.; Sumpf, B.; Tränkle, G.

    2016-04-01

    Raman spectroscopy in the visible spectral range is of great interest due to resonant Raman effects. Nevertheless, fluorescence and ambient light can mask the weak Raman lines. Shifted excitation Raman difference spectroscopy is a demonstrated tool to overcome this drawback. To apply this method, a light source with two alternating wavelengths is necessary. The spectral distance between these two wavelengths has to be adapted to the width of the Raman signal. According to the sample under investigation the width of the Raman signal could be in the range of 3 cm-1 - 12 cm-1. In this work, a micro-integrated light source emitting at 488 nm with a continuous wavelength tuning range up to 2 nm (83 cm-1) is presented. The pump source, a DFB laser emitting at 976 nm, and a periodically poled lithium niobate (PPLN) ridge waveguide crystal is used for the second harmonic generation (SHG). Both components are mounted on a μ-Peltier-element for temperature control. Here, a common wavelength tuning of the pump wavelength and the acceptance bandwidth of the SHG crystal via temperature is achieved. With the results the light source is suitable for portable Raman and SERDS experiments with a flexible spectral distance between both excitation wavelengths for SERDS with respect to the sample under investigation.

  20. High-power green light generation by second harmonic generation of single-frequency tapered diode lasers

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Andersen, Peter E.; Sumpf, Bernd

    2010-01-01

    We demonstrate the generation of high power (>1.5W) and single-frequency green light by single-pass second harmonic generation of a high power tapered diode laser. The tapered diode laser consists of a DBR grating for wavelength selectivity, a ridge section and a tapered section. The DBR tapered...... laser emits in excess of 9 W single-frequency output power with a good beam quality. The output from the tapered diode laser is frequency doubled using periodically poled MgO:LiNbO3. We investigate the modulation potential of the green light and improve the modulation depth from 1:4 to 1:50....