WorldWideScience

Sample records for external light source

  1. Near Infrared Photoimmunotherapy with Combined Exposure of External and Interstitial Light Sources.

    Science.gov (United States)

    Maruoka, Yasuhiro; Nagaya, Tadanobu; Sato, Kazuhide; Ogata, Fusa; Okuyama, Shuhei; Choyke, Peter L; Kobayashi, Hisataka

    2018-02-21

    Near infrared photoimmunotherapy (NIR-PIT) is a new target-cell-specific cancer treatment that induces highly selective necrotic/immunogenic cell death after systemic administration of a photoabsorber antibody conjugate and subsequent NIR light exposure. However, the depth of NIR light penetration in tissue (approximately 2 cm) with external light sources limits the therapeutic effects of NIR-PIT. Interstitial light exposure using cylindrical diffusing optical fibers can overcome this limitation. The purpose in this study was to compare three NIR light delivery methods for treating tumors with NIR-PIT using a NIR laser system at an identical light energy; external exposure alone, interstitial exposure alone, and the combination. Panitumumab conjugated with the photoabsorber IRDye-700DX (pan-IR700) was intravenously administered to mice with A431-luc xenografts which are epithelial growth factor receptor (EGFR) positive. One and 2 days later, NIR light was administered to the tumors using one of three methods. Interstitial exposure alone and in combination with external sources showed the greatest decrease in bioluminescence signal intensity. Additionally, the combination of external and interstitial NIR light exposure showed significantly greater tumor size reduction and prolonged survival after NIR-PIT compared to external exposure alone. This result suggested that the combination of external and interstitial NIR light exposure was more effective than externally applied light alone. Although external exposure is the least invasive means of delivering light, the combination of external and interstitial exposures produces superior therapeutic efficacy in tumors greater than 2 cm in depth from the tissue surface.

  2. Enhanced catalytic activity without the use of an external light source using microwave-synthesized CuO nanopetals

    Directory of Open Access Journals (Sweden)

    Govinda Lakhotiya

    2017-05-01

    Full Text Available We report enhanced catalytic activity of CuO nanopetals synthesized by microwave-assisted wet chemical synthesis. The catalytic reaction of CuO nanopetals and H2O2 was studied with the application of external light source and also under dark conditions for the degradation of the hazardous dye methylene blue. The CuO nanopetals showed significant catalytic activity for the fast degradation of methylene blue and rhodamine B (RhB under dark conditions, without the application of an external light source. This increased catalytic activity was attributed to the co-operative role of H2O2 and the large specific surface area (≈40 m2·g−1 of the nanopetals. We propose a detail mechanism for this fast degradation. A separate study of the effect of different H2O2 concentrations for the degradation of methylene blue under dark conditions is also illustrated.

  3. 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

  4. Exploration of external light trapping for photovoltaic modules

    NARCIS (Netherlands)

    van Dijk, L.; van de Groep, J.; Di Vece, M.; Schropp, R.E.I.

    2016-01-01

    The reflection of incident sunlight by photovoltaic modules prevents them from reaching their theoretical energy conversion limit. We explore the effectiveness of a universal external light trap that can tackle this reflection loss. A unique feature of external light traps is their capability to

  5. Light sources and light pollution

    International Nuclear Information System (INIS)

    Pichler, G.

    2005-01-01

    From the dawn of mankind fire and light sources in general played an essential role in everyday life and protection over night. The development of new light sources went through many stages and is now an immense technological achievement, but also a threat for the wildlife at night, mainly because of the so-called light pollution. This paper discusses several very successful light sources connected with low pressure mercury and sodium vapour electric discharges. The luminous efficacy, colour rendering index and other lighting features cannot be always satisfactory, but at least some of the features can be much better than those met by the standard tungsten filament bulbs. High-pressure metal-vapour discharge lamps definitely have a good colour rendering index and a relatively high luminosity. Different light sources with burners at high pressure are discussed, paying special attention to their spectrum. The paper investigates new trends in development through a number of examples with non-toxic elements and pulsed electric discharge, which may be good news in terms of clean environment and energy savings. Light emitting diodes have recently appeared as worthy competitors to conventional light sources. White LEDs have approached 100 lumen/Watt efficacy in laboratories. This suggests that in some not very distant future they could completely replace high-pressure lamps, at least in indoor lighting. The article speculates on new developments which combine trends in nano technology and material science. The paper concludes with light pollution in view of several recent observations of plant and animal life at night in the vicinity of strong light sources. Photo-induced changes at the cell level may completely alter the normal life of plants and animals.(author)

  6. 3D-Printed external light traps for solar cells

    NARCIS (Netherlands)

    van Dijk, L.; Paetzold, U.W.; Blab, Gerhard; Marcus, E.A.P.; Oostra, A.J.; van de Groep, J.; Polman, A.; Schropp, R.E.I.; Di Vece, M.

    2015-01-01

    We demonstrate a universally applicable 3D-printed external light trap for solar cells. We placed a macroscopic external light trap made of smoothened, silver coated plastic at the sun-facing surface of different types of solar cells. The trap consists of a reflective parabolic concentrator on top

  7. Concurrent sourcing and external supplier opportunism

    DEFF Research Database (Denmark)

    Mols, Niels Peter

    costs of opportunism are determined as a product of four factors. The four factors are: likelihood of discovering supplier opportunism, buyer’s internalized quantity as reaction to supplier opportunism, asset specificity of external supplier’s investments, and multiplicator effects. Each......When a firm simultaneously makes and buys the same components then the firm uses concurrent sourcing. This paper presents an agency model for explaining how and when concurrent sourcing reduces the likelihood of external supplier opportunism. In the proposed model, the external supplier’s expected...... of these factors are explained and discussed in the paper. The paper ends by offering a number of theoretical and managerial implications....

  8. Photonic crystal light source

    Science.gov (United States)

    Fleming, James G [Albuquerque, NM; Lin, Shawn-Yu [Albuquerque, NM; Bur, James A [Corrales, NM

    2004-07-27

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  9. External dosimetry sources and shielding

    International Nuclear Information System (INIS)

    Calisto, Washington

    1994-01-01

    A definition of external dosimetry r external sources dosimetry,physical and mathematical treatment of the interaction of gamma radiation with a minimal area in that direction. Concept of attenuation coefficient, cumulated effect by polyenergetic sources, exposition rate, units, cumulated dose,shielding, foton shielding, depth calculation, materials used for shielding.Beta shielding, consideration of range and maximum β energy , low stopping radiation by use of low Z shielding. Tables for β energy of β emitters, I (tau) factor, energy-range curves for β emitters in aqueous media, gamma attenuation factors for U, W and Pb. Y factor for bone tissue,muscle and air, build-up factors

  10. External Mask Based Depth and Light Field Camera

    Science.gov (United States)

    2013-12-08

    External mask based depth and light field camera Dikpal Reddy NVIDIA Research Santa Clara, CA dikpalr@nvidia.com Jiamin Bai University of California...passive depth acquisition technology is illustrated by the emergence of light field camera companies like Lytro [1], Raytrix [2] and Pelican Imaging

  11. HOW DO FIRMS SOURCE EXTERNAL KNOWLEDGE FOR INNOVATION? ANALYSING EFFECTS OF DIFFERENT KNOWLEDGE SOURCING METHODS

    OpenAIRE

    KI H. KANG; JINA KANG

    2009-01-01

    In the era of "open innovation", external knowledge is a very important source for technology innovation. In this paper, we investigate the relationship between external knowledge and performance of technology innovation. The effect of external knowledge on the performance of technology innovation can vary with different external knowledge sourcing methods. We identify three ways of external knowledge sourcing: information transfer from informal network, R&D collaboration and technology acqui...

  12. The effect of external visible light on the breakdown voltage of a long discharge tube

    Science.gov (United States)

    Shishpanov, A. I.; Ionikh, Yu. Z.; Meshchanov, A. V.

    2016-06-01

    The breakdown characteristics of a discharge tube with a configuration typical of gas-discharge light sources and electric-discharge lasers (a so-called "long discharge tube") filled with argon or helium at a pressure of 1 Torr have been investigated. A breakdown has been implemented using positive and negative voltage pulses with a linear leading edge having a slope dU/ dt ~ 10-107 V/s. Visible light from an external source (halogen incandescent lamp) is found to affect the breakdown characteristics. The dependences of the dynamic breakdown voltage of the tube on dU/ dt and on the incident light intensity are measured. The breakdown voltage is found to decrease under irradiation of the high-voltage anode of the tube in a wide range of dU/ dt. A dependence of the effect magnitude on the light intensity and spectrum is obtained. Possible physical mechanisms of this phenomenon are discussed.

  13. Internal Versus External Knowledge Sourcing Of Subsidiaries

    DEFF Research Database (Denmark)

    Gammelgaard, Jens; Pedersen, Torben

    2003-01-01

    When building up competences, a subsidiary of a multinational corporation (MNC) may rely onexternal knowledge sources like customers, suppliers, competitors or local science centers. Internalsourcing is also available through knowledge offered by headquarters or other affiliates. Thequestion...... is whether the two kinds of sources are mutual exclusive. A dilemma or organizationaltrade-off is foreseeable, since the more the subsidiary adapts its knowledge creation processes tohost country institutions, the less it will be able to utilize internal knowledge sources due to theinstitutional distance...... between the external and internal networks. However, newer organizationalforms, like the concept of the `differentiated MNC', imply a relatively smooth flow of knowledgeinside the MNC, indicating that we should not expect an organizational trade-off between internaland external sources. The subsidiary...

  14. ENHANCEMENT OF A SUNSPOT LIGHT WALL WITH EXTERNAL DISTURBANCES

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shuhong; Zhang, Jun [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Erdélyi, Robert, E-mail: shuhongyang@nao.cas.cn [Solar Physics and Space Plasma Research Centre, School of Mathematics and Statistics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2016-12-20

    Based on the Interface Region Imaging Spectrograph observations, we study the response of a solar sunspot light wall to external disturbances. A flare occurrence near the light wall caused material to erupt from the lower solar atmosphere into the corona. Some material falls back to the solar surface and hits the light bridge (i.e., the base of the light wall), then sudden brightenings appear at the wall base followed by the rise of wall top, leading to an increase of the wall height. Once the brightness of the wall base fades, the height of the light wall begins to decrease. Five hours later, another nearby flare takes place, and a bright channel is formed that extends from the flare toward the light bridge. Although no obvious material flow along the bright channel is found, some ejected material is conjectured to reach the light bridge. Subsequently, the wall base brightens and the wall height begins to increase again. Once more, when the brightness of the wall base decays, the wall top fluctuates to lower heights. We suggest, based on the observed cases, that the interaction of falling material and ejected flare material with the light wall results in the brightenings of wall base and causes the height of the light wall to increase. Our results reveal that the light wall can be not only powered by the linkage of p -mode from below the photosphere, but may also be enhanced by external disturbances, such as falling material.

  15. Improvements to the internal and external antenna H(-) ion sources at the Spallation Neutron Source.

    Science.gov (United States)

    Welton, R F; Dudnikov, V G; Han, B X; Murray, S N; Pennisi, T R; Pillar, C; Santana, M; Stockli, M P; Turvey, M W

    2014-02-01

    The Spallation Neutron Source (SNS), a large scale neutron production facility, routinely operates with 30-40 mA peak current in the linac. Recent measurements have shown that our RF-driven internal antenna, Cs-enhanced, multi-cusp ion sources injects ∼55 mA of H(-) beam current (∼1 ms, 60 Hz) at 65-kV into a Radio Frequency Quadrupole (RFQ) accelerator through a closely coupled electrostatic Low-Energy Beam Transport system. Over the last several years a decrease in RFQ transmission and issues with internal antennas has stimulated source development at the SNS both for the internal and external antenna ion sources. This report discusses progress in improving internal antenna reliability, H(-) yield improvements which resulted from modifications to the outlet aperture assembly (applicable to both internal and external antenna sources) and studies made of the long standing problem of beam persistence with the external antenna source. The current status of the external antenna ion source will also be presented.

  16. Fiber-based broadband black-light source

    OpenAIRE

    Sylvestre , Thibaut; Lee , Min Won; Ragueh , A. R.; Stiller , Birgit; Fanjoux , Gil; Barviau , B.; Mussot , A.; Kudlinski , A.

    2012-01-01

    International audience; Black-Light or Wood's lamp refers to sources that emit long-wavelength ultraviolet radiation (UV-A) from 315 nm and little visible light till 410 nm (blue). In this paper, we present a new fibre-based source of "black light", a source that emits broadband ultraviolet radiation but only small amounts of visible light and no infrared light. We made this source by pumping a specially designed silica photonic crystal fibre (PCF) with 355 nm light pulses from a Q-switched f...

  17. Organizing for External Knowledge Sourcing

    DEFF Research Database (Denmark)

    Rabbiosi, Larissa; Reichstein, Toke

    2011-01-01

    The aim of this article is to provide an introduction to the special issue. We briefly consider the external knowledge sourcing and organizing for innovation literatures, which offer a background for the special issue, and we highlight their mutual dialogue. We then illustrate the main findings o...

  18. 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.

  19. 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

    According to the Machinery Statistics of the Ministry of Economy, Trade and Industry, the production of incandescent lamps in Japan in 2007 was 990 million units (90.0% of the previous year's total), in which the production of incandescent lamps for general lighting was 110 million units (90.0% of the previous year's total) and of tungsten-halogen lamps was 44 million units (96.6% of the previous year's total). The production of fluorescent lamps was 927 million units (93.9% of the previous year's total), in which general fluorescent lamps, excluding those for LCD back lighting, was 320 million units (87.2% of the previous year's total). Also, the production of HID lamps was 10 million units (101.5% of the previous year's total). On the other hand, when the numbers of sales are compared with the sales of the previous year, incandescent lamps for general use was 99.8%, tungsten-halogen lamps was 96.9%, fluorescent lamps was 95.9%, and HID lamps was 98.9%. Self-ballasted fluorescent lamps alone showed an increase in sales as strong as 29 million units, or 121.7% of the previous year's sales. It is considered that the switchover of incandescent lamps to HID lamps was promoted for energy conservation and carbon dioxide reduction with the problem of global warming in the background. In regard to exhibitions, Lighting Fair 2007 was held in Tokyo in March, and LIGHTFAIR INTERNATIONAL 2007 was held in New York in May. Regarding academic conferences, LS:11 (the 11th International Symposium on the Science & Technology of Light Sources) was held in Shanghai in May, and the First International Conference on White LEDs and Solid State Lighting was held in Tokyo in November. Both conferences suggested that there are strong needs and concerns now about energy conservation, saving natural resources, and restrictions of hazardous materials. In regard to incandescent lamps, the development of products aiming at higher efficacy, electric power savings, and longer life was advanced by

  20. Two-stream instability for a light ion beam-plasma system with external magnetic field

    International Nuclear Information System (INIS)

    Okada, T.; Tazawa, H.

    1992-12-01

    For inertial confinement fusion, a focused light ion beam (LIB) is required to propagate stably through a chamber to a target. We have pointed out that the applied external magnetic field is important for LIB propagation. To investigate the influence of the external magnetic field on the LIB propagation, we analysed the electrostatic dispersion relation of magnetized light ion beam-plasma system. The particle in-cell (PIC) simulation results are presented for a light ion beam-plasma system with external magnetic field. (author)

  1. Subcriticality calculation in nuclear reactors with external neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Adilson Costa da; Martinez, Aquilino Senra; Silva, Fernando Carvalho da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear]. E-mails: asilva@con.ufrj.br; aquilino@lmp.ufrj.br; fernando@con.ufrj.br

    2007-07-01

    The main objective of this paper consists on the development of a methodology to monitor subcriticality. We used the inverse point kinetic equation with 6 precursor groups and external neutron sources for the calculation of reactivity. The input data for the inverse point kinetic equation was adjusted, in order to use the neutron counting rates obtained from the subcritical multiplication (1/M) in a nuclear reactor. In this paper, we assumed that the external neutron sources strength is constant and we define it in terms of a known initial condition. The results obtained from inverse point kinetic equation with external neutron sources were compared with the results obtained with a benchmark calculation, and showed good accuracy (author)

  2. Subcriticality calculation in nuclear reactors with external neutron sources

    International Nuclear Information System (INIS)

    Silva, Adilson Costa da; Martinez, Aquilino Senra; Silva, Fernando Carvalho da

    2007-01-01

    The main objective of this paper consists on the development of a methodology to monitor subcriticality. We used the inverse point kinetic equation with 6 precursor groups and external neutron sources for the calculation of reactivity. The input data for the inverse point kinetic equation was adjusted, in order to use the neutron counting rates obtained from the subcritical multiplication (1/M) in a nuclear reactor. In this paper, we assumed that the external neutron sources strength is constant and we define it in terms of a known initial condition. The results obtained from inverse point kinetic equation with external neutron sources were compared with the results obtained with a benchmark calculation, and showed good accuracy (author)

  3. Quantum hacking on a practical continuous-variable quantum cryptosystem by inserting an external light

    Science.gov (United States)

    Qin, Hao; Kumar, Rupesh; Alleaume, Romain

    2015-10-01

    We report here a new side channel attack on a practical continuous-variable (CV) quantum key distribution (QKD) system. Inspired by blinding attack in discrete-variable QKD, we formalize an attack strategy by inserting an external light into a CV QKD system implemented Gaussian-modulated coherent state protocol and show that our attack can compromise its practical security. In this attack, we concern imperfections of a balanced homodyne detector used in CV QKD. According to our analysis, if one inserts an external light into Bob's signal port, due to the imperfect subtraction from the homodyne detector, the leakage of the external light contributes a displacement on the homodyne signal which causes detector electronics saturation. In consequence, Bob's quadrature measurement is not linear with the quadrature sent by Alice. By considering such vulnerability, a potential Eve can launch a full intercept-resend attack meanwhile she inserts an external light into Bob's signal port. By selecting proper properties of the external light, Eve actively controls the induced displacement value from the inserted light which results saturation of homodyne detection. In consequence, Eve can bias the excess noise due to the intercept-resend attack and the external light, such that Alice and Bob believe their excess noise estimation is below the null key threshold and they can still share a secret key. Our attack shows that the detector loopholes also exist in CV QKD, and it seems influence all the CV QKD systems using homodyne detection, since all the practical detectors have finite detection range.

  4. Optimal condition of memristance enhancement circuit using external voltage source

    Directory of Open Access Journals (Sweden)

    Hiroya Tanaka

    2014-05-01

    Full Text Available Memristor provides nonlinear response in the current-voltage characteristic and the memristance is modulated using an external voltage source. We point out by solving nonlinear equations that an optimal condition of the external voltage source exists for maximizing the memristance in such modulation scheme. We introduce a linear function to describe the nonlinear time response and derive an important design guideline; a constant ratio of the frequency to the amplitude of the external voltage source maximizes the memristance. The analysis completely accounts for the memristance behavior.

  5. Radio-isotope powered light source

    International Nuclear Information System (INIS)

    Spottiswoode, N.L.; Ryden, D.J.

    1979-01-01

    The light source described comprises a radioisotope fuel source, thermal insulation against heat loss, a biological shield against the escape of ionizing radiation and a material having a surface which attains incandescence when subject to isotope decay heat. There is then a means for transferring this heat to produce incandescence of the surface and thus emit light. A filter associated with the surface permits a relatively high transmission of visible radiation but has a relatively high reflectance in the infra red spectrum. Such light sources require the minimum of attention and servicing and are therefore suitable for use in navigational aids such as lighthouses and lighted buoys. The isotope fuel sources and thus the insulation and shielding and the incandescent material can be chosen for the use required and several sources, materials, means of housing etc. are detailed. Operation and efficiency are discussed. (U.K.)

  6. Overview of light sources powered by tritium

    International Nuclear Information System (INIS)

    Wu Jian; Lei Jiarong; Liu Wenke

    2012-01-01

    Due to their long lifespan and stable intensity, light sources initiated by tritium instead of electricity or batteries are suitable for low level lighting applications. Therefore, tritium-based radioluminescent (RL) light sources are widely used in both military and civil applications. However, traditional tritium lights with the gas tube structure have several shortcomings: (1) the phosphors are opaque; (2) the glass tube is fragile and easily broken; and (3) the beta kinetic energy is attenuated due to the sorption by the gas; etc. As a result, further application of the tritium lights is limited. In this paper, the lighting mechanism and radiation safety of tritium-based RL light sources are briefly reviewed. Besides, the history and prospects of the development of tritium-based RL light source are discussed. Due to their long lifespan and stable intensity, light sources initiated by tritium instead of electricity or batteries are suitable for low level lighting applications. Therefore, tritium- based radioluminescent (RL) light sources are widely used in both military and civil applications. However, traditional tritium lights with the gas tube structure have several short- comings: (1) the phosphors are opaque; (2) the glass tube is fragile and easily broken; and (3) the beta kinetic energy is attenuated due to the sorption by the gas; etc. As a result, further application of the tritium lights is limited. In this paper, the lighting mechanism and radiation safety of tritium-based RL, light sources are briefly reviewed. Besides, the history and prospects of the development of tritium-based RL light source are discussed. (authors)

  7. Calibration and check light source

    Energy Technology Data Exchange (ETDEWEB)

    Nejedla, B; Krotil, J

    1979-02-15

    The light source is designed for calibrating photomultipliers and checking the function of the thermoluminescent dosemeters evaluation equipment. The check light source consists of a polymer material-based (polyvinyl toluene) plastic scintillator and a 2-phenyl-5-(4-bisphenyl)-1,3,4-oxadiazol and/or paraterphenyl activator, and of emission spectrum shifters for response in the green and the blue light regions. The plastic scintillator is sealed in a case to whose bottom a radiation source is fixed, such as a /sup 90/Sr-/sup 90/Y source of an activity of 1.85x10/sup 3/s/sup -1/ to 0.74x10/sup 9/s/sup -1/.

  8. Development of a clockwork light source to enable cervical inspection by village health workers

    Directory of Open Access Journals (Sweden)

    Steventon Richard

    2002-12-01

    Full Text Available Abstract Background Cervical cancer can often be prevented by screening and may be curable if identified and treated in its early stages. However, 80% of new cases occur in less-developed countries where cervical cancer screening programmes are small-scale or non-existent. This is a human tragedy of great proportion, with many of those affected being young mothers. There is some evidence that cancerous or precancerous lesions may be detected by visual inspection with acetic acid (VIA and field studies indicate that this technique is effective, safe and acceptable to women. However, the provision of a light source for inspection of the cervix presents a major problem in less-developed countries, where candles and torches often provide the only means of illumination. Our objective was to develop a light source based on clockwork technology, that required no batteries or external power source. Methods We adapted the design of a commercially available clockwork torch to provide a light source for cervical inspection. The light source was then tested under laboratory conditions in a comparison with other illumination methods typically used in this application. Results The light source gave illuminance levels greater than those produced by any other method tested, and also had considerable advantages in terms of ease of use and safety. Conclusion This design is small, compact, effective and safe to use and promises a better and more affordable means of visualising the cervix. Further field trials of VIA are now required which incorporate this light source.

  9. Effects of read-out light sources and ambient light on radiochromic film

    International Nuclear Information System (INIS)

    Butson, Martin J.; Yu, Peter K.N.; Metcalfe, Peter E.

    1998-01-01

    Both read-out light sources and ambient light sources can produce a marked effect on coloration of radiochromic film. Fluorescent, helium neon laser, light emitting diode (LED) and incandescent read-out light sources produce an equivalent dose coloration of 660 cGy h -1 , 4.3 cGy h -1 , 1.7 cGy h -1 and 2.6 cGy h -1 respectively. Direct sunlight, fluorescent light and incandescent ambient light produce an equivalent dose coloration of 30 cGy h -1 , 18 cGy h -1 and 0 cGy h -1 respectively. Continuously on, fluorescent light sources should not be used for film optical density evaluation and minimal exposure to any light source will increase the accuracy of results. (author)

  10. Experimental study of electromagnetic radiation from a faster-than-light vacuum macroscopic source

    Energy Technology Data Exchange (ETDEWEB)

    Bessarab, A.V. [Russian Federal Nuclear Center-All-Russia Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, 607188 (Russian Federation); Martynenko, S.P. [Russian Federal Nuclear Center-All-Russia Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, 607188 (Russian Federation); Prudkoi, N.A. [Russian Federal Nuclear Center-All-Russia Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, 607188 (Russian Federation); Soldatov, A.V. [Russian Federal Nuclear Center-All-Russia Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, 607188 (Russian Federation)]. E-mail: soldatov@vniief.ru; Terekhin, V.A. [Russian Federal Nuclear Center-All-Russia Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, 607188 (Russian Federation)

    2006-08-15

    The effect which manifests itself in the form of directed electromagnetic pulses (EMP) initiated by an X-ray incident obliquely upon a conducting surface has been confirmed and investigated experimentally in detail. A planar accelerating diode comprising a metallic cathode and grid anode was initiated with an oblique short soft-X-ray pulse from a point laser-plasma source. Then a source of directed EMP-a current of accelerated photoelectrons-was formed whose boundary ran along the anode external surface with a faster-than-light velocity. The plasma was formed when short-pulse ({approx}0.3ns) laser radiation from ISKRA-5 facility was focused on a plane Au target. The amplitude-in-time and spatial characteristics of radiation emitted by the faster-than-light source have been measured. Parameters of the accelerated electron current have been measured too.

  11. Does External Knowledge Sourcing Enhance Market Performance? Evidence from the Korean Manufacturing Industry.

    Science.gov (United States)

    Lee, Kibaek; Yoo, Jaeheung; Choi, Munkee; Zo, Hangjung; Ciganek, Andrew P

    2016-01-01

    Firms continuously search for external knowledge that can contribute to product innovation, which may ultimately increase market performance. The relationship between external knowledge sourcing and market performance is not well-documented. The extant literature primarily examines the causal relationship between external knowledge sources and product innovation performance or to identify factors which moderates the relationship between external knowledge sourcing and product innovation. Non-technological innovations, such as organization and marketing innovations, intervene in the process of external knowledge sourcing to product innovation to market performance but has not been extensively examined. This study addresses two research questions: does external knowledge sourcing lead to market performance and how does external knowledge sourcing interact with a firm's different innovation activities to enhance market performance. This study proposes a comprehensive model to capture the causal mechanism from external knowledge sourcing to market performance. The research model was tested using survey data from manufacturing firms in South Korea and the results demonstrate a strong statistical relationship in the path of external knowledge sourcing (EKS) to product innovation performance (PIP) to market performance (MP). Organizational innovation is an antecedent to EKS while marketing innovation is a consequence of EKS, which significantly influences PIP and MP. The results imply that any potential EKS effort should also consider organizational innovations which may ultimately enhance market performance. Theoretical and practical implications are discussed as well as concluding remarks.

  12. 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...

  13. Synchrotron light source data book

    International Nuclear Information System (INIS)

    Murphy, J.

    1989-01-01

    The ''Synchrotron Light Source Data Book'' is as its name implies a collection of data on existing and planned synchrotron light sources. The intention was to provide a compendium of tools for the design of electron storage rings as synchrotron radiation sources. The slant is toward the accelerator physicist as other booklets such as the X-ray Data Booklet, edited by D. Vaughan (LBL PUB-490), address the 'use' of synchrotron radiation. It is hoped that the booklet serves as a pocket sized reference to facilitate back of the envelope type calculations. It contains some useful formulae in 'practical units' and a brief description of many of the existing and planned light source lattices

  14. Flexible deep-ultraviolet light-emitting diodes for significant improvement of quantum efficiencies by external bending

    KAUST Repository

    Shervin, Shahab

    2018-01-26

    Deep ultraviolet (DUV) light at the wavelength range of 250‒280 nm (UVC spectrum) is essential for numerous applications such as sterilization, purification, sensing, and communication. III-nitride-based DUV light-emitting diodes (DUV LEDs), like other solid-state lighting sources, offer a great potential to replace the conventional gas-discharged lamps with short lifetimes and toxic-element-bearing nature. However, unlike visible LEDs, the DUV LEDs are still suffering from low quantum efficiencies (QEs) and low optical output powers. In this work, reported is a new route to improve QEs of AlGaN-based DUV LEDs using mechanical flexibility of recently developed bendable thin-film structures. Numerical studies show that electronic band structures of AlGaN heterostructures and resulting optical and electrical characteristics of the devices can be significantly modified by external bending through active control of piezoelectric polarization. Internal quantum efficiency (IQE) is enhanced higher than three times, when the DUV LEDs are moderately bent to induce in-plane compressive strain in the heterostructure. Furthermore, efficiency droop at high injection currents is mitigated and turn-on voltage of diodes decreases with the same bending condition. The concept of bendable DUV LEDs with a controlled external strain can provide a new path for high-output-power and high-efficiency devices.

  15. Flexible deep-ultraviolet light-emitting diodes for significant improvement of quantum efficiencies by external bending

    KAUST Repository

    Shervin, Shahab; Oh, Seung Kyu; Park, Hyun Jung; Lee, Keon Hwa; Asadirad, Mojtaba; Kim, Seung Hwan; Kim, Jeomoh; Pouladi, Sara; Lee, Sung-Nam; Li, Xiaohang; Kwak, Joon-Seop; Ryou, Jae-Hyun

    2018-01-01

    Deep ultraviolet (DUV) light at the wavelength range of 250‒280 nm (UVC spectrum) is essential for numerous applications such as sterilization, purification, sensing, and communication. III-nitride-based DUV light-emitting diodes (DUV LEDs), like other solid-state lighting sources, offer a great potential to replace the conventional gas-discharged lamps with short lifetimes and toxic-element-bearing nature. However, unlike visible LEDs, the DUV LEDs are still suffering from low quantum efficiencies (QEs) and low optical output powers. In this work, reported is a new route to improve QEs of AlGaN-based DUV LEDs using mechanical flexibility of recently developed bendable thin-film structures. Numerical studies show that electronic band structures of AlGaN heterostructures and resulting optical and electrical characteristics of the devices can be significantly modified by external bending through active control of piezoelectric polarization. Internal quantum efficiency (IQE) is enhanced higher than three times, when the DUV LEDs are moderately bent to induce in-plane compressive strain in the heterostructure. Furthermore, efficiency droop at high injection currents is mitigated and turn-on voltage of diodes decreases with the same bending condition. The concept of bendable DUV LEDs with a controlled external strain can provide a new path for high-output-power and high-efficiency devices.

  16. Standard light source utilizing spontaneous radiation

    International Nuclear Information System (INIS)

    Yamamoto, O.; Takenaga, M.; Tsujimoto, Y.

    1975-01-01

    A standard light source is described utilizing spontaneous radiation made by mixing a fluorescent substance LnVO 4 :X (wherein Ln is Y or Gd, and X is Dy or Eu) with a radioactive substance containing a radioactive isotope which is less in the degree of temperature variation of the intensity of emitted light and excellent in stability. Particularly when used in a light-receiving device having photomultiplier tubes, the said light source emits light quite similar to that of a thermoluminescent substance such as CaSO 4 :X (wherein X is Im, Dy, Sm or Mn), LiF or Mg 2 SiO 4 :Tb, and is excellent as a calibration high-stability standard light source for use in the above-mentioned light-receiving device. (auth)

  17. Stability and vibration control in synchrotron light source buildings

    Energy Technology Data Exchange (ETDEWEB)

    Godel, J.B.

    1991-01-01

    Synchrotron light sources have undergone three generations of development in the last two decades. The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory has two second generation'' storage rings that currently provide the world's most intense sources of photons in the VUV and X-ray spectral ranges. There are almost 90 beam lines serving a community of 2600 scientists from 370 institutions. They are engaged in basic and applied research in physics, chemistry, biology, medicine, materials science and various technologies. When design of the NSLS began in 1977, emphasis was given to the stability of the concrete slab on which the storage rings and experimental beam lines were placed. Stability is the result of controlling: vibration from sources internal and external to the building, thermal effects of air and water temperature variations, foundation settlement and contact between the slab and underlying subsoil. With the advent of new research where highly focused beams of x-rays must be placed on increasingly smaller targets located 35 meters or more from the source, and the development of x-ray lithography with resolutions approaching 0.1 micron at chip exposure stations, even greater attention to stability is required in building designs. This paper will review the results of the successful NSLS experience and give an integrated design approach that includes elements which contribute to instabilities, and the means available to reduce them to acceptable levels.

  18. Stability and vibration control in synchrotron light source buildings

    Energy Technology Data Exchange (ETDEWEB)

    Godel, J.B.

    1991-12-31

    Synchrotron light sources have undergone three generations of development in the last two decades. The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory has two ``second generation`` storage rings that currently provide the world`s most intense sources of photons in the VUV and X-ray spectral ranges. There are almost 90 beam lines serving a community of 2600 scientists from 370 institutions. They are engaged in basic and applied research in physics, chemistry, biology, medicine, materials science and various technologies. When design of the NSLS began in 1977, emphasis was given to the stability of the concrete slab on which the storage rings and experimental beam lines were placed. Stability is the result of controlling: vibration from sources internal and external to the building, thermal effects of air and water temperature variations, foundation settlement and contact between the slab and underlying subsoil. With the advent of new research where highly focused beams of x-rays must be placed on increasingly smaller targets located 35 meters or more from the source, and the development of x-ray lithography with resolutions approaching 0.1 micron at chip exposure stations, even greater attention to stability is required in building designs. This paper will review the results of the successful NSLS experience and give an integrated design approach that includes elements which contribute to instabilities, and the means available to reduce them to acceptable levels.

  19. Stability and vibration control in synchrotron light source buildings

    International Nuclear Information System (INIS)

    Godel, J.B.

    1991-01-01

    Synchrotron light sources have undergone three generations of development in the last two decades. The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory has two ''second generation'' storage rings that currently provide the world's most intense sources of photons in the VUV and X-ray spectral ranges. There are almost 90 beam lines serving a community of 2600 scientists from 370 institutions. They are engaged in basic and applied research in physics, chemistry, biology, medicine, materials science and various technologies. When design of the NSLS began in 1977, emphasis was given to the stability of the concrete slab on which the storage rings and experimental beam lines were placed. Stability is the result of controlling: vibration from sources internal and external to the building, thermal effects of air and water temperature variations, foundation settlement and contact between the slab and underlying subsoil. With the advent of new research where highly focused beams of x-rays must be placed on increasingly smaller targets located 35 meters or more from the source, and the development of x-ray lithography with resolutions approaching 0.1 micron at chip exposure stations, even greater attention to stability is required in building designs. This paper will review the results of the successful NSLS experience and give an integrated design approach that includes elements which contribute to instabilities, and the means available to reduce them to acceptable levels

  20. Does External Knowledge Sourcing Enhance Market Performance? Evidence from the Korean Manufacturing Industry

    Science.gov (United States)

    Lee, Kibaek; Yoo, Jaeheung; Choi, Munkee; Zo, Hangjung; Ciganek, Andrew P.

    2016-01-01

    Firms continuously search for external knowledge that can contribute to product innovation, which may ultimately increase market performance. The relationship between external knowledge sourcing and market performance is not well-documented. The extant literature primarily examines the causal relationship between external knowledge sources and product innovation performance or to identify factors which moderates the relationship between external knowledge sourcing and product innovation. Non-technological innovations, such as organization and marketing innovations, intervene in the process of external knowledge sourcing to product innovation to market performance but has not been extensively examined. This study addresses two research questions: does external knowledge sourcing lead to market performance and how does external knowledge sourcing interact with a firm’s different innovation activities to enhance market performance. This study proposes a comprehensive model to capture the causal mechanism from external knowledge sourcing to market performance. The research model was tested using survey data from manufacturing firms in South Korea and the results demonstrate a strong statistical relationship in the path of external knowledge sourcing (EKS) to product innovation performance (PIP) to market performance (MP). Organizational innovation is an antecedent to EKS while marketing innovation is a consequence of EKS, which significantly influences PIP and MP. The results imply that any potential EKS effort should also consider organizational innovations which may ultimately enhance market performance. Theoretical and practical implications are discussed as well as concluding remarks. PMID:28006022

  1. Leveraging External Sources of Innovation

    DEFF Research Database (Denmark)

    West, Joel; Bogers, Marcel

    2014-01-01

    , it suggests a four-phase model in which a linear process—(1) obtaining, (2) integrating, and (3) commercializing external innovations—is combined with (4) interaction between the firm and its collaborators. This model is used to classify papers taken from the top 25 innovation journals, complemented by highly...... cited work beyond those journals. A review of 291 open innovation-related publications from these sources shows that the majority of these articles indeed address elements of this inbound open innovation process model. Specifically, it finds that researchers have front-loaded their examination...... external innovations create value rather than how firms capture value from those innovations. Finally, the interaction phase considers both feedback for the linear process and reciprocal innovation processes such as cocreation, network collaboration, and community innovation. This review and synthesis...

  2. 3D-printed concentrator arrays for external light trapping on thin film solar cells

    NARCIS (Netherlands)

    van Dijk, Lourens; Marcus, E.A.P.; Oostra, A.J.; Schropp, R.E.I.; Vece, Di M.

    2015-01-01

    After our recent demonstration of a 3D-printed external light trap on a small solar cell, we now consider its potential for large solar panels. An external light trap consists of a parabolic concentrator and a spacer that redirects the photons that are reflected by the solar cell back towards the

  3. 3D-printed concentrator arrays for external light trapping on thin film solar cells

    NARCIS (Netherlands)

    van Dijk, Lourens; Marcus, E. A. Pepijn; Oostra, A. Jolt; Schropp, Ruud E. I.; Di Vece, Marcel

    After our recent demonstration of a 3D-printed external light trap on a small solar cell, we now consider its potential for large solar panels. An external light trap consists of a parabolic concentrator and a spacer that redirects the photons that are reflected by the solar cell back towards the

  4. External technology sourcing : The effect of uncertainty on governance mode choice

    NARCIS (Netherlands)

    van de Vrande, V.; Vanhaverbeke, W.P.M.; Duijsters, G.M.

    2009-01-01

    External knowledge sourcing is increasingly important for corporate entrepreneurship. In this study, we examine the effect of external and relational uncertainty on the governance choice for inter-organizational technology sourcing. We develop a number of hypotheses about the impact of environmental

  5. 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.

  6. A comparative perspective on external technology sourcing modalities: The role of synergies

    NARCIS (Netherlands)

    Sabidussi, A.; Lokshin, B.; Leeuw, de T.; Duysters, G.M.; Bremmers, H.J.; Omta, S.W.F.

    2014-01-01

    This paper assesses the impact on innovative performance of alternative external sourcing strategies. In particular, the study under discussion compared external sourcing strategies based on specialization to those based on integrating various sourcing modalities (e.g., alliances and M&As).

  7. A comparative perspective on external technology sourcing modalities : The role of synergies

    NARCIS (Netherlands)

    Sabidussi, A.; Lokshin, B.; de Leeuw, T.; Duijsters, G.M.; Bremmers, H.; Omta, O.

    2014-01-01

    This paper assesses the impact on innovative performance of alternative external sourcing strategies. In particular, the study under discussion compared external sourcing strategies based on specialization to those based on integrating various sourcing modalities (e.g., alliances and M&As). Survey

  8. Development and evaluation of a light-emitting diode endoscopic light source

    Science.gov (United States)

    Clancy, Neil T.; Li, Rui; Rogers, Kevin; Driscoll, Paul; Excel, Peter; Yandle, Ron; Hanna, George; Copner, Nigel; Elson, Daniel S.

    2012-03-01

    Light-emitting diode (LED) based endoscopic illumination devices have been shown to have several benefits over arclamp systems. LEDs are energy-efficient, small, durable, and inexpensive, however their use in endoscopy has been limited by the difficulty in efficiently coupling enough light into the endoscopic light cable. We have demonstrated a highly homogenised lightpipe LED light source that combines the light from four Luminus LEDs emitting in the red, green, blue and violet using innovative dichroics that maximise light throughput. The light source spectrally combines light from highly divergent incoherent sources that have a Lambertian intensity profile to provide illumination matched to the acceptance numerical aperture of a liquid light guide or fibre bundle. The LED light source was coupled to a standard laparoscope and performance parameters (power, luminance, colour temperature) compared to a xenon lamp. Although the total illuminance from the endoscope was lower, adjustment of the LEDs' relative intensities enabled contrast enhancement in biological tissue imaging. The LED light engine was also evaluated in a minimally invasive surgery (MIS) box trainer and in vivo during a porcine MIS procedure where it was used to generate 'narrowband' images. Future work using the violet LED could enable photodynamic diagnosis of bladder cancer.

  9. Increasing the Brightness of Light Sources

    OpenAIRE

    Fu, Ling

    2006-01-01

    In modern illumination systems, compact size and high brightness are important features. Light recycling allows an increase of the spectral radiance (brightness) emitted by a light source for the price of reducing the total radiant power. Light recycling means returning part of the emitted light to the source where part of it will escape absorption. As a result, the output brightness can be increased in a restricted phase space, ...

  10. Biological stimulation of the Human skin applying health promoting light and plasma sources

    Energy Technology Data Exchange (ETDEWEB)

    Awakowicz, P.; Bibinov, N. [Center for Plasma Science and Technology, Ruhr-University, Bochum (Germany); Born, M.; Niemann, U. [Philips Research, Aachen (Germany); Busse, B. [Zell-Kontakt GmbH, Noerten-Hardenberg (Germany); Gesche, R.; Kuehn, S.; Porteanu, H.E. [Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Berlin (Germany); Helmke, A. [University of Applied Sciences and Arts, Goettingen (Germany); Kaemling, A.; Wandke, D. [CINOGY GmbH, Duderstadt (Germany); Kolb-Bachofen, V.; Liebmann, J. [Institute for Immunobiology, Heinrich-Heine University, Duesseldorf (Germany); Kovacs, R.; Mertens, N.; Scherer, J. [Aurion Anlagentechnik GmbH, Seligenstadt (Germany); Oplaender, C.; Suschek, C. [Clinic for Plastic Surgery, University Clinic, Aachen (Germany); Vioel, W. [Laser-Laboratorium, Goettingen (Germany); University of Applied Sciences and Arts, Goettingen (Germany)

    2009-10-15

    In the frame of BMBF project ''BioLiP'', new physical treatment techniques aiming at medical treatment of the human skin have been developed. The acronym BioLiP stands for ''Desinfektion, Entkeimung und biologische Stimulation der Haut durch gesundheitsfoerdernde Licht- und Plasmaquellen'' (Disinfection, germ reduction and biological stimulation of the human skin by health promoting light and plasma sources). A source applying a low-temperature dielectric barrier discharge plasma (DBD) has been investigated on its effectiveness for skin disinfection and stimulation of biological material. Alternatively an atmospheric plasma source consisting of a microwave resonator combined with a solid state power oscillator has been examined. This concept which allows for a compact and efficient design avoiding external microwave power supply and matching units has been optimized with respect to nitrogen monoxide (NO) production in high yields. In both cases various application possibilities in the medical and biological domain are opened up. Light sources in the visible spectral range have been investigated with respect to the proliferation of human cell types. Intensive highly selective blue light sources based on LED technology can slow down proliferation rates without inducing toxic effects which offers new opportunities for treatments of so-called hyperproliferative skin conditions (e.g. with psoriasis or in wound healing) using UV-free light. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. External light activates hair follicle stem cells through eyes via an ipRGC-SCN-sympathetic neural pathway.

    Science.gov (United States)

    Fan, Sabrina Mai-Yi; Chang, Yi-Ting; Chen, Chih-Lung; Wang, Wei-Hung; Pan, Ming-Kai; Chen, Wen-Pin; Huang, Wen-Yen; Xu, Zijian; Huang, Hai-En; Chen, Ting; Plikus, Maksim V; Chen, Shih-Kuo; Lin, Sung-Jan

    2018-06-29

    Changes in external light patterns can alter cell activities in peripheral tissues through slow entrainment of the central clock in suprachiasmatic nucleus (SCN). It remains unclear whether cells in otherwise photo-insensitive tissues can achieve rapid responses to changes in external light. Here we show that light stimulation of animals' eyes results in rapid activation of hair follicle stem cells with prominent hair regeneration. Mechanistically, light signals are interpreted by M1-type intrinsically photosensitive retinal ganglion cells (ipRGCs), which signal to the SCN via melanopsin. Subsequently, efferent sympathetic nerves are immediately activated. Increased norepinephrine release in skin promotes hedgehog signaling to activate hair follicle stem cells. Thus, external light can directly regulate tissue stem cells via an ipRGC-SCN autonomic nervous system circuit. Since activation of sympathetic nerves is not limited to skin, this circuit can also facilitate rapid adaptive responses to external light in other homeostatic tissues.

  12. Influence of external source location in the reactivity calculation

    International Nuclear Information System (INIS)

    Silva, Adilson Costa da; Silva, Fernando Carvalho da; Martinez, Aquilino Senra

    2011-01-01

    We used the neutron diffusion equation with external neutron sources, in cartesian geometry and the two groups of energy, to verify the influence of external neutron source locations in the reactivity calculation. For this, a coarse mesh finite difference method was developed for the adjoint flux calculation and simplifies reactivity calculation in PWR type reactor, which uses the output of the nodal expansion method. The results were obtained for different locations on the two-dimensional plane, as well as for different types of fuel elements in the reactor core. (author)

  13. Influence of external source location in the reactivity calculation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Adilson Costa da; Silva, Fernando Carvalho da; Martinez, Aquilino Senra, E-mail: asilva@con.ufrj.b, E-mail: fernando@con.ufrj.b, E-mail: Aquilino@lmp.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2011-07-01

    We used the neutron diffusion equation with external neutron sources, in cartesian geometry and the two groups of energy, to verify the influence of external neutron source locations in the reactivity calculation. For this, a coarse mesh finite difference method was developed for the adjoint flux calculation and simplifies reactivity calculation in PWR type reactor, which uses the output of the nodal expansion method. The results were obtained for different locations on the two-dimensional plane, as well as for different types of fuel elements in the reactor core. (author)

  14. Backscatter absorption gas imaging systems and light sources therefore

    Science.gov (United States)

    Kulp, Thomas Jan [Livermore, CA; Kliner, Dahv A. V. [San Ramon, CA; Sommers, Ricky [Oakley, CA; Goers, Uta-Barbara [Campbell, NY; Armstrong, Karla M [Livermore, CA

    2006-12-19

    The location of gases that are not visible to the unaided human eye can be determined using tuned light sources that spectroscopically probe the gases and cameras that can provide images corresponding to the absorption of the gases. The present invention is a light source for a backscatter absorption gas imaging (BAGI) system, and a light source incorporating the light source, that can be used to remotely detect and produce images of "invisible" gases. The inventive light source has a light producing element, an optical amplifier, and an optical parametric oscillator to generate wavelength tunable light in the IR. By using a multi-mode light source and an amplifier that operates using 915 nm pump sources, the power consumption of the light source is reduced to a level that can be operated by batteries for long periods of time. In addition, the light source is tunable over the absorption bands of many hydrocarbons, making it useful for detecting hazardous gases.

  15. Sensitivity of a fibre scattered-light interferometer to external phase perturbations in an optical fibre

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, A E; Potapov, V T [V.A.Kotel' nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Fryazino Branch, Fryazino, Moscow region (Russian Federation); Gorshkov, B G [OOO ' Petrofaiber' , Russia, Tula region, Novomoskovsk (Russian Federation)

    2015-10-31

    Sensitivity of a fibre scattered-light interferometer to external phase perturbations is studied for the first time. An expression is derived for an average power of a useful signal at the interferometer output under external harmonic perturbations in a signal fibre of the interferometer. It is shown that the maximum sensitivity of the scattered-light interferometer depends on the dispersion of the interferogram intensity. An average signal-to-noise ratio is determined theoretically and experimentally at the output of the interferometer at different amplitudes of external perturbations. Using the measured dependences of the signal-to-noise ratio, the threshold sensitivity of the fibre scattered-light interferometer to external phase perturbations is found. The results obtained can be used to optimise characteristics of optical time-domain reflectometers and to design individual phase-sensitive fibre-optic sensors. (laser applications and other topics in quantum electronics)

  16. Light Sources and Ballast Circuits

    Science.gov (United States)

    Yorifuji, Takashi; Sakai, Makoto; Yasuda, Takeo; Maehara, Akiyoshi; Okada, Atsunori; Gouriki, Takeshi; Mannami, Tomoaki

    discharge models were reported. Further, studies on ultra high-pressure mercury lamps as light sources for projectors are becoming the mainstream of HID lamp related researches. For high-pressure sodium lamps, many studies on plant growing and pest control utilizing low insect attracting aspects were also reported in 2006. Additionally, for discharge lamps, the minimum sustaining electric power for arc tubes employed in electrode-less compact fluorescent lamps was investigated. For Hg-free rare-gas fluorescent lamps, a luminance of 10,000cd/m2 was attained by a 1 meter-long external duplex spiral electrode prototype using Xe/Ne barrier discharge. As to startup circuits, the commercialization of energy saving and high value added products mainly associated with fluorescent lamps and HID lamps are becoming common. Further, the miniaturization of startup circuits for self electronic-ballasted lamps has advanced. Speaking of the overall light sources and startup circuits in 2006 and with the enforcement of RoHS in Europe in July, the momentum toward hazardous substance-free and energy saving initiatives has been enhanced from the perspective of protecting the global environment. It is anticipated that similar restrictions will be globally enforced in the future.

  17. Time-dependent anisotropic external sources in transient 3-D transport code TORT-TD

    International Nuclear Information System (INIS)

    Seubert, A.; Pautz, A.; Becker, M.; Dagan, R.

    2009-01-01

    This paper describes the implementation of a time-dependent distributed external source in TORT-TD by explicitly considering the external source in the ''fixed-source'' term of the implicitly time-discretised 3-D discrete ordinates transport equation. Anisotropy of the external source is represented by a spherical harmonics series expansion similar to the angular fluxes. The YALINA-Thermal subcritical assembly serves as a test case. The configuration with 280 fuel rods has been analysed with TORT-TD using cross sections in 18 energy groups and P1 scattering order generated by the KAPROS code system. Good agreement is achieved concerning the multiplication factor. The response of the system to an artificial time-dependent source consisting of two square-wave pulses demonstrates the time-dependent external source capability of TORT-TD. The result is physically plausible as judged from validation calculations. (orig.)

  18. 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.

  19. Synchrotron light sources in developing countries

    Science.gov (United States)

    Mtingwa, Sekazi K.; Winick, Herman

    2018-03-01

    We discuss the role that synchrotron light sources, such as SESAME, could play in improving the socioeconomic conditions in developing countries. After providing a brief description of a synchrotron light source, we discuss the important role that they played in the development of several economically emerging countries. Then we describe the state of synchrotron science in South Africa and that country’s leadership role in founding the African Light Source initiative. Next, we highlight a new initiative called Lightsources for Africa, the Americas & Middle East Project, which is a global initiative led by the International Union of Pure and Applied Physics and the International Union of Crystallography, with initial funding provided by the International Council for Science. Finally, we comment on a new technology called the multibend achromat that has launched a new paradigm for the design of synchrotron light sources that should be attractive for construction in developing countries.

  20. High-power LED light sources for optical measurement systems operated in continuous and overdriven pulsed modes

    Science.gov (United States)

    Stasicki, Bolesław; Schröder, Andreas; Boden, Fritz; Ludwikowski, Krzysztof

    2017-06-01

    The rapid progress of light emitting diode (LED) technology has recently resulted in the availability of high power devices with unprecedented light emission intensities comparable to those of visible laser light sources. On this basis two versatile devices have been developed, constructed and tested. The first one is a high-power, single-LED illuminator equipped with exchangeable projection lenses providing a homogenous light spot of defined diameter. The second device is a multi-LED illuminator array consisting of a number of high-power LEDs, each integrated with a separate collimating lens. These devices can emit R, G, CG, B, UV or white light and can be operated in pulsed or continuous wave (CW) mode. Using an external trigger signal they can be easily synchronized with cameras or other devices. The mode of operation and all parameters can be controlled by software. Various experiments have shown that these devices have become a versatile and competitive alternative to laser and xenon lamp based light sources. The principle, design, achieved performances and application examples are given in this paper.

  1. Plant Growth Absorption Spectrum Mimicking Light Sources

    Directory of Open Access Journals (Sweden)

    Jwo-Huei Jou

    2015-08-01

    Full Text Available Plant factories have attracted increasing attention because they can produce fresh fruits and vegetables free from pesticides in all weather. However, the emission spectra from current light sources significantly mismatch the spectra absorbed by plants. We demonstrate a concept of using multiple broad-band as well as narrow-band solid-state lighting technologies to design plant-growth light sources. Take an organic light-emitting diode (OLED, for example; the resulting light source shows an 84% resemblance with the photosynthetic action spectrum as a twin-peak blue dye and a diffused mono-peak red dye are employed. This OLED can also show a greater than 90% resemblance as an additional deeper red emitter is added. For a typical LED, the resemblance can be improved to 91% if two additional blue and red LEDs are incorporated. The approach may facilitate either an ideal use of the energy applied for plant growth and/or the design of better light sources for growing different plants.

  2. Ideas for future synchrotron light sources

    International Nuclear Information System (INIS)

    Jackson, A.; Hassenzahl, W.; Meddahi, M.

    1992-03-01

    Synchrotron light sources have advanced in the past two-to-three decades through three ''generations,'' from irritating parasitic sources on high-energy physics accelerators to dedicated electron and position storage rings of unprecedented low emittance, utilizing undulator and wiggler magnets. The evolution through these three generations followed a predicable, science-driven, course towards brighter beams of VUV- and x-radiation. The requirements of future light sources is not so clear. The limit on how emittance has certainly not been reached, and diffraction-limited sources at shorter wavelengths would be the natural progression from previous generations. However, scientists are now looking at other radiation characteristics that might better serve their needs, for example, more coherent power, fast switching polarization, ultra-short (sub-picosecond) time structure, and synchronized beams for pump-probe experiments. This paper discusses some current ideas that might drive the fourth-generation synchrotron light source

  3. Internal heat gain from different light sources in the building lighting systems

    Directory of Open Access Journals (Sweden)

    Suszanowicz Dariusz

    2017-01-01

    Full Text Available EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and the parameters for their functioning under identical conditions were recorded. The heat flux emitted by 1 W nominal power of each light source was determined. Based on the study results, the empirical coefficients of heat emission and energy efficiency ratios for different types of lighting sources (dependent lamp power and the light output were designated. In the heat balance of the building, the designated rates allow for precise determination of the internal heat gains coming from lighting systems using various light sources and also enable optimization of lighting systems of buildings that are used in different ways.

  4. Internal heat gain from different light sources in the building lighting systems

    Science.gov (United States)

    Suszanowicz, Dariusz

    2017-10-01

    EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and the parameters for their functioning under identical conditions were recorded. The heat flux emitted by 1 W nominal power of each light source was determined. Based on the study results, the empirical coefficients of heat emission and energy efficiency ratios for different types of lighting sources (dependent lamp power and the light output) were designated. In the heat balance of the building, the designated rates allow for precise determination of the internal heat gains coming from lighting systems using various light sources and also enable optimization of lighting systems of buildings that are used in different ways.

  5. 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

  6. Enhanced Light Harvesting in Dye-Sensitized Solar Cell Using External Lightguide

    Directory of Open Access Journals (Sweden)

    Chi-Hui Chien

    2011-01-01

    Full Text Available An external lightguide (EL for enhancing the light-harvesting efficiency of dye-sensitized solar cells (DSSCs was designed and developed. The EL attached to the exterior of a DSSC photoelectrode directed light on a dye-covered nanoporous TiO2 film (D-NTF of the photoelectrode. Experimental tests confirmed that the EL increased the light-harvesting efficiency of a DSSC with an active area of 0.25 cm2 by 30.69%. Photocurrent density and the power conversion efficiency were also increased by 38.12% and 25.09%, respectively.

  7. Photodynamic therapy to destroy pneumonia associated microorganisms using external irradiation source

    Science.gov (United States)

    Bassi, Rosane; Myakawa, Walter; Navarro, Ricardo S.; Baptista, Alessandra; Ribeiro, Martha Simões; Nunez, Silvia Cristina

    2018-02-01

    An endotracheal tube (ETT) is required for the management of critically ill, mechanically ventilated patients. Ventilatorassociated pneumonia (VAP) affects patients hospitalized in intensive care units; its risk of occurrence is 1% to up 3% for each day of mechanical ventilation. The polymicrobial nature of VAP is established with mixed bacterial-fungal biofilms colonizing the ETT. The microbial interaction enhances the microbial pathogenesis contributing to high indexes of morbidity/mortality. Antimicrobial Photodynamic Therapy (aPDT) could be a suitable therapy for decontamination of oral cavity and ETT at the same time, but the use of a fiber optics inside the ETT seems to not be appropriated since a cannula for secretion aspiration has to be introduced into the ETT to keep it's lumen. The aim of this study is to proof the concept that an external light source from a LED is capable of reach all areas of the ETT. We use a commercial ETT, 60μM methylene blue (MB), and a 660nm diode laser and calculated the transmission coefficient of light in different situations as only tube, tube with biofilm and biofilm+MB. The results prove that is possible to transmit light through the tube even in the presence of MB and biofilm although a high attenuation of about 60% was measured depending on the tested condition.

  8. Collimating lens for light-emitting-diode light source based on non-imaging optics.

    Science.gov (United States)

    Wang, Guangzhen; Wang, Lili; Li, Fuli; Zhang, Gongjian

    2012-04-10

    A collimating lens for a light-emitting-diode (LED) light source is an essential device widely used in lighting engineering. Lens surfaces are calculated by geometrical optics and nonimaging optics. This design progress does not rely on any software optimization and any complex iterative process. This method can be used for any type of light source not only Lambertian. The theoretical model is based on point source. But the practical LED source has a certain size. So in the simulation, an LED chip whose size is 1 mm*1 mm is used to verify the feasibility of the model. The mean results show that the lenses have a very compact structure and good collimating performance. Efficiency is defined as the ratio of the flux in the illuminated plane to the flux from LED source without considering the lens material transmission. Just investigating the loss in the designed lens surfaces, the two types of lenses have high efficiencies of more than 90% and 99%, respectively. Most lighting area (possessing 80% flux) radii are no more than 5 m when the illuminated plane is 200 m away from the light source.

  9. Physics Challenges for ERL Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Lia Merminga

    2004-07-01

    We present an overview of the physics challenges encountered in the design and operation of Energy Recovering Linac (ERL) based light sources. These challenges include the generation and preservation of low emittance, high-average current beams, manipulating and preserving the transverse and longitudinal phase space, control of the multipass beam breakup instability, efficient extraction of higher order mode power and RF control and stability of the superconducting cavities. These key R&D issues drive the design and technology choices for proposed ERL light sources. Simulations and calculations of these processes will be presented and compared with experimental data obtained at the Jefferson Lab FEL Upgrade, a 10 mA ERL light source presently in commissioning, and during a 1 GeV demonstration of energy recovery at CEBAF.

  10. BERKELEY: Light Source anniversary

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The staff of the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory has been too busy to celebrate the first anniversary of the facility's transition from a US Department of Energy construction project to operating third-generation synchrotron radiation source. Based on a 1.5-GeV, low-emittance electron storage ring that accommodates up to ten insertion-device radiation sources optimized primarily for the soft X-ray and vacuum ultra-violet regions of the spectrum, the ALS has completed

  11. BERKELEY: Light Source anniversary

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1994-10-15

    The staff of the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory has been too busy to celebrate the first anniversary of the facility's transition from a US Department of Energy construction project to operating third-generation synchrotron radiation source. Based on a 1.5-GeV, low-emittance electron storage ring that accommodates up to ten insertion-device radiation sources optimized primarily for the soft X-ray and vacuum ultra-violet regions of the spectrum, the ALS has completed.

  12. Photon Science at Modern Light Sources

    Science.gov (United States)

    Arthur, John

    2009-12-01

    More than 50 large x-ray and UV light sources based on high-energy electron accelerators are in operation around the world, serving a scientific community numbering in the tens of thousands. These sources generate synchrotron radiation from accelerated electrons or positrons. The development of synchrotron light sources over the last 40 years has fueled an exponential increase in x-ray source brightness of more than 10 orders of magnitude. The next large advance in source potential is now underway, with the commissioning of the first x-ray Free-Electron Laser (FEL) sources. Using high-energy electron linear accelerators, these facilities produce sub-picosecond pulses of hard x-rays with peak brightness more than 10 orders of magnitude greater than current synchrotron facilities. FEL x-ray facilities will soon be operational in the US, Japan, and Germany. Research at modern light sources makes use of a wide range of experimental techniques. Many experiments are designed to study the structure of matter at the atomic scale using elastic x-ray scattering. This technique has been particularly effective for determining the structures of biological molecules, such as proteins, viruses, and drugs. Inelastic x-ray scattering, or x-ray absorption followed by emission of electrons or photons, can give information about the electronic structures of atoms, which can be used to deduce local environment information such as atomic species, bonding state, geometry of neighboring atoms, or magnetic state. For some techniques involving x-ray emission from a sample, cryogenic detectors with energy resolution at the ˜10 eV level or better would be very helpful. Shifts in electron energy levels associated with bonding states and magnetic states are typically several eV, while the energy structure associated with Compton inelastic scattering is typically in the range of a few tens of eV. Current energy-resolving detectors used at synchrotron light sources are hampered by either poor

  13. National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Hulbert, S.L.; Lazarz, N.M.

    1991-04-01

    This report discussion research being conducted at the National Synchrotron light source. In particular, this report contains operations summaries; symposia, workshops, and projects; NSLS highlights; and abstracts of science at the NSLS

  14. Irradiation Pattern Analysis for Designing Light Sources-Based on Light Emitting Diodes

    International Nuclear Information System (INIS)

    Rojas, E.; Stolik, S.; La Rosa, J. de; Valor, A.

    2016-01-01

    Nowadays it is possible to design light sources with a specific irradiation pattern for many applications. Light Emitting Diodes present features like high luminous efficiency, durability, reliability, flexibility, among others as the result of its rapid development. In this paper the analysis of the irradiation pattern of the light emitting diodes is presented. The approximation of these irradiation patterns to both, a Lambertian, as well as a Gaussian functions for the design of light sources is proposed. Finally, the obtained results and the functionality of bringing the irradiation pattern of the light emitting diodes to these functions are discussed. (Author)

  15. Corporate risk and external sourcing: A study of Scandinavian multinational firms

    DEFF Research Database (Denmark)

    Aabo, Tom; Pantzalis, Christos; Sørensen, Helle

    2016-01-01

    data by surveying Scandinavian non-financial firms. We find that highly international firms reduce corporate risk by externally sourcing from foreign suppliers both compared to sourcing from own production facilities abroad (due to superior flexibility) and compared to domestic sourcing (due...

  16. The 4th Generation Light Source at Jefferson Lab

    International Nuclear Information System (INIS)

    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 Shinn; Christopher Tennant; Richard Walker; Shukui Zhang; Gwyn Williams

    2007-01-01

    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

  17. Miniature radioactive light source

    International Nuclear Information System (INIS)

    Caffarella, T.E.; Radda, G.J.; Dooley, H.H.

    1980-01-01

    A miniature radioactive light source for illuminating digital watches is described consisting of a glass tube with improved laser sealing and strength containing tritium gas and a transducer responsive to the gas. (U.K.)

  18. 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

  19. Light and Light Sources High-Intensity Discharge Lamps

    CERN Document Server

    Flesch, Peter G

    2006-01-01

    Light and Light Sources gives an introduction to the working principles of high-intensity discharge (HID) lamps and points out challenges and problems associated with the development and operation of HID lamps. The state-of-the-art in electrode and plasma diagnostics as well as numerical methods used for the understanding of HID lamps are described. This volume addresses students as well as scientists and researchers at universities and in industry.

  20. The Role of External Knowledge Sources and Organizational Design in the Process of Opportunity Exploitation

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Lyngsie, Jacob; A. Zahra, Shaker

    involving 536 Danish firms shows that the use of external knowledge sources is positively associated with opportunity exploitation, but the strength of this association is significantly influenced by organizational designs that enable the firm to access external knowledge during the process of exploiting......Research highlights the role of external knowledge sources in the recognition of strategic opportunities, but is less forthcoming with respect to the role of such sources during the process of exploiting or realizing opportunities. We build on the knowledge-based view to propose that realizing...... opportunities often involves significant interactions with external knowledge sources. Organizational design can facilitate a firm’s interactions with these sources, while achieving coordination among organizational members engaged in opportunity exploitation. Our analysis of a double-respondent survey...

  1. The Role of External Knowledge Sources and Organizational Design in the Process of Opportunity Exploitation

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Lyngsie, Jacob; Zahra, Shaker A.

    2013-01-01

    involving 536 Danish firms shows that the use of external knowledge sources is positively associated with opportunity exploitation, but the strength of this association is significantly influenced by organizational designs that enable the firm to access external knowledge during the process of exploiting......Research highlights the role of external knowledge sources in the recognition of strategic opportunities but is less forthcoming with respect to the role of such sources during the process of exploiting or realizing opportunities. We build on the knowledge-based view to propose that realizing...... opportunities often involves significant interactions with external knowledge sources. Organizational design can facilitate a firm's interactions with these sources, while achieving coordination among organizational members engaged in opportunity exploitation. Our analysis of a double-respondent survey...

  2. Enhancement of white light OLED efficiency by combining both internal and external light extraction structures

    Science.gov (United States)

    Kao, I.-Ling; Ku, Chun-Neng; Chen, Yi-Ping; Lin, Ding-Zheng

    2012-09-01

    We proposed an internal nanostructure with a high reflective index planarization layer to solve the optical loss due to the reflective index mismatch between ITO and glass substrate. In our experiments, we found the electrical property of OLED device was significantly influenced by the internal nanostructures without planarization layer. Moreover, the internal extraction structure (IES) is not necessarily beneficial for light extraction. Therefore, we proposed a new substrate combine both internal and external extraction structure (EES) to extract trapping light. We successfully developed a high refractive index (N 1.7) planarization material with flat surface (RMS roughness < 2 nm), and improved about 70% device efficiency compared to traditional glass substrate.

  3. Laser driven white light source for BRDF measurement

    DEFF Research Database (Denmark)

    Amdemeskel, Mekbib Wubishet; Thorseth, Anders; Dam-Hansen, Carsten

    2017-01-01

    In this paper, we will present a setup with laser driven light source (LDLS) for measuring a 2D bidirectional reflectance distribution function (BRDF). We have carried out measurements to acquire the BRDF of different samples based on our setup: which consists of a new laser driven broadband light...... source (UV-VIS-NIR), spectroradiometer and sample holder stepper motor in a dark UV-protected environment. Here, we introduced a special kind of light source which has a bright, stable, broad spectral range and well collimated light output to give a very good angular resolution. The experimental results...

  4. Influence of the external neutron sources in the criticality prediction using 1/M curve

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Valmir [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, 21941-972 Rio de Janeiro (Brazil); Carvalho da Silva, Fernando [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, 21941-972 Rio de Janeiro (Brazil); Martinez, Aquilino Senra [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, 21941-972 Rio de Janeiro (Brazil)]. E-mail: aquilino@lmp.ufrj.br

    2005-11-15

    The influence of external neutron sources in the process to obtain the criticality condition is estimated. To reach this objective, the three-dimensional neutron diffusion equation in two groups of energy is solved, for a subcritical PWR reactor core with external neutron sources. The results are compared with the solution of the corresponding problem without external neutron sources, that is an eigenvalue problem. The method developed for this purposes it makes use of both the nodal method (for calculation of the neutron flux) and the finite differences method (for calculation of the adjoint flux). A coarse mesh finite difference method was developed for the adjoint flux calculation, which uses the output of the nodal expansion method. The results regarding the influence of the external neutron source presence for attaining criticality have shown that far from criticality it is necessary to calculate the reactivity values of the system.

  5. Influence of the external neutron sources in the criticality prediction using 1/M curve

    International Nuclear Information System (INIS)

    Pereira, Valmir; Carvalho da Silva, Fernando; Martinez, Aquilino Senra

    2005-01-01

    The influence of external neutron sources in the process to obtain the criticality condition is estimated. To reach this objective, the three-dimensional neutron diffusion equation in two groups of energy is solved, for a subcritical PWR reactor core with external neutron sources. The results are compared with the solution of the corresponding problem without external neutron sources, that is an eigenvalue problem. The method developed for this purposes it makes use of both the nodal method (for calculation of the neutron flux) and the finite differences method (for calculation of the adjoint flux). A coarse mesh finite difference method was developed for the adjoint flux calculation, which uses the output of the nodal expansion method. The results regarding the influence of the external neutron source presence for attaining criticality have shown that far from criticality it is necessary to calculate the reactivity values of the system

  6. The Advanced Light Source

    International Nuclear Information System (INIS)

    Jackson, A.

    1991-05-01

    The Advanced Light Source (ALS), a national user facility currently under construction at the Lawrence Berkeley Laboratory (LBL), is a third-generation synchrotron light source designed to produce extremely bright beams of synchrotron radiation in the energy range from a few eV to 10 keV. The design is based on a 1--1.9-GeV electron storage ring (optimized at 1.5 GeV), and utilizes special magnets, known as undulators and wigglers (collectively referred to as insertion devices), to generate the radiation. The facility is scheduled to begin operating in April 1993. In this paper we describe the progress in the design, construction, and commissioning of the accelerator systems, insertion devices, and beamlines. Companion presentations at this conference give more detail of specific components in the ALS, and describe the activities towards establishing an exciting user program. 3 figs., 2 tabs

  7. External knowledge sourcing in the Spanish archaeological sector: Mapping the emergent stage of a business activity

    Directory of Open Access Journals (Sweden)

    Eva Parga-Dans

    2017-03-01

    Full Text Available Recent studies of innovation highlight the importance of external knowledge sourcing. Existing empirical works are based on national surveys and specific industries. The present study contributes to the analysis of strategies for sourcing external knowledge, based on a specific case study and moment in time: the Spanish archaeological sector and its emergence as a new business activity. Our results show that external knowledge sourcing involves diverse mechanisms, agents and two main strategies: cooperation and knowledge acquisition. In an expanding knowledge-based sector emerging in an uncertain context and whose sources of knowledge are scattered, innovation strategy should focus on the search for external knowledge –cooperation and acquisition strategies-, rather than on internal sources.

  8. Spectral matching research for light-emitting diode-based neonatal jaundice therapeutic device light source

    Science.gov (United States)

    Gan, Ruting; Guo, Zhenning; Lin, Jieben

    2015-09-01

    To decrease the risk of bilirubin encephalopathy and minimize the need for exchange transfusions, we report a novel design for light source of light-emitting diode (LED)-based neonatal jaundice therapeutic device (NJTD). The bilirubin absorption spectrum in vivo was regarded as target. Based on spectral constructing theory, we used commercially available LEDs with different peak wavelengths and full width at half maximum as matching light sources. Simple genetic algorithm was first proposed as the spectral matching method. The required LEDs number at each peak wavelength was calculated, and then, the commercial light source sample model of the device was fabricated to confirm the spectral matching technology. In addition, the corresponding spectrum was measured and the effect was analyzed finally. The results showed that fitted spectrum was very similar to the target spectrum with 98.86 % matching degree, and the actual device model has a spectrum close to the target with 96.02 % matching degree. With higher fitting degree and efficiency, this matching algorithm is very suitable for light source matching technology of LED-based spectral distribution, and bilirubin absorption spectrum in vivo will be auspicious candidate for the target spectrum of new LED-based NJTD light source.

  9. Tunable light source for fiber optic lighting applications

    Science.gov (United States)

    Narendran, Nadarajah; Bierman, Andrew; Finney, Mark J.; Edwards, Ian K.

    1997-09-01

    This paper examines the possibility of tuning the lamp spectrum to compensate for color distortions in fiber optic lighting systems. Because most optical fibers have strong absorption in the blue and red wavelength regions, white light entering and propagating down an optical fiber suffers varied amounts of attenuation as a function of wavelength. As a result, the light exiting the optical fiber has a greenish tint that the lighting design community considers undesirable in interior lighting applications. HID lamps are commonly used for the light source in this industry. Certain classes of HID lamps tend to shift in color when their operating position or the input voltage to the lamp is changed. An experimental study is being conducted to characterize the color shift properties of a small HID lamp as a function of tilt and input voltage. The study also examines the possibility of exploiting this color shift to compensate for the color distortions caused by optical fibers. The details of the experiment and the results are presented in this manuscript.

  10. Concepts for external light trapping and its utilization in colored and image displaying photovoltaic modules

    NARCIS (Netherlands)

    van Dijk, L.; van de Groep, J.; Veldhuizen, L.W.; Di Vece, M.; Schropp, R.E.I.

    2017-01-01

    The reflection of incident sunlight prevents photovoltaic modules from reaching their full energy conversion potential. Recently, we demonstrated significant absorption enhancement in various solar cells by external light trapping, using 3D-printed and milled light traps. In order to facilitate

  11. National Synchrotron Light Source

    International Nuclear Information System (INIS)

    van Steenbergen, A.

    1979-01-01

    The National Synchrotron Light Source comprises two high intensity electron storage rings for the generation of intense fluxes of synchrotron radiation in the vuv wavelength domain (700 MeV e - ring) and in the x-ray wavelength domain (2.5 GeV e - ring). A description is presented of the basic facility and the characteristics of the synchrotron radiation sources. The present plans for specific beam lines will be enumerated and the planned use of beam wigglers and undulators will be discussed

  12. Advanced Light Source

    International Nuclear Information System (INIS)

    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

  13. A two-metric proposal to specify the color-rendering properties of light sources for retail lighting

    Science.gov (United States)

    Freyssinier, Jean Paul; Rea, Mark

    2010-08-01

    Lighting plays an important role in supporting retail operations, from attracting customers, to enabling the evaluation of merchandise, to facilitating the completion of the sale. Lighting also contributes to the identity, comfort, and visual quality of a retail store. With the increasing availability and quality of white LEDs, retail lighting specifiers are now considering LED lighting in stores. The color rendering of light sources is a key factor in supporting retail lighting goals and thus influences a light source's acceptance by users and specifiers. However, there is limited information on what consumers' color preferences are, and metrics used to describe the color properties of light sources often are equivocal and fail to predict preference. The color rendering of light sources is described in the industry solely by the color rendering index (CRI), which is only indirectly related to human perception. CRI is intended to characterize the appearance of objects illuminated by the source and is increasingly being challenged because new sources are being developed with increasingly exotic spectral power distributions. This paper discusses how CRI might be augmented to better use it in support of the design objectives for retail merchandising. The proposed guidelines include the use of gamut area index as a complementary metric to CRI for assuring good color rendering.

  14. Spectral characteristics of light sources for S-cone stimulation.

    Science.gov (United States)

    Schlegelmilch, F; Nolte, R; Schellhorn, K; Husar, P; Henning, G; Tornow, R P

    2002-11-01

    Electrophysiological investigations of the short-wavelength sensitive pathway of the human eye require the use of a suitable light source as a S-cone stimulator. Different light sources with their spectral distribution properties were investigated and compared with the ideal S-cone stimulator. First, the theoretical background of the calculation of relative cone energy absorption from the spectral distribution function of the light source is summarized. From the results of the calculation, the photometric properties of the ideal S-cone stimulator will be derived. The calculation procedure was applied to virtual light sources (computer generated spectral distribution functions with different medium wavelengths and spectrum widths) and to real light sources (blue and green light emitting diodes, blue phosphor of CRT-monitor, multimedia projector, LCD monitor and notebook display). The calculated relative cone absorbencies are compared to the conditions of an ideal S-cone stimulator. Monochromatic light sources with wavelengths of less than 456 nm are close to the conditions of an ideal S-cone stimulator. Spectrum widths up to 21 nm do not affect the S-cone activation significantly (S-cone activation change < 0.2%). Blue light emitting diodes with peak wavelength at 448 nm and spectrum bandwidth of 25 nm are very useful for S-cone stimulation (S-cone activation approximately 95%). A suitable display for S-cone stimulation is the Trinitron computer monitor (S-cone activation approximately 87%). The multimedia projector has a S-cone activation up to 91%, but their spectral distribution properties depends on the selected intensity. LCD monitor and notebook displays have a lower S-cone activation (< or = 74%). Carefully selecting the blue light source for S-cone stimulation can reduce the unwanted L-and M-cone activation down to 4% for M-cones and 1.5% for L-cones.

  15. High-intensity sources for light ions

    International Nuclear Information System (INIS)

    Leung, K.N.

    1995-10-01

    The use of the multicusp plasma generator as a source of light ions is described. By employing radio-frequency induction discharge, the performance of the multicusp source is greatly improved, both in lifetime and in high brightness H + and H - beam production. A new technique for generating multiply-charged ions in this type of ion source is also presented

  16. Impact of external sources of infection on the dynamics of bovine tuberculosis in modelled badger populations

    Directory of Open Access Journals (Sweden)

    Hardstaff Joanne L

    2012-06-01

    Full Text Available Abstract Background The persistence of bovine TB (bTB in various countries throughout the world is enhanced by the existence of wildlife hosts for the infection. In Britain and Ireland, the principal wildlife host for bTB is the badger (Meles meles. The objective of our study was to examine the dynamics of bTB in badgers in relation to both badger-derived infection from within the population and externally-derived, trickle-type, infection, such as could occur from other species or environmental sources, using a spatial stochastic simulation model. Results The presence of external sources of infection can increase mean prevalence and reduce the threshold group size for disease persistence. Above the threshold equilibrium group size of 6–8 individuals predicted by the model for bTB persistence in badgers based on internal infection alone, external sources of infection have relatively little impact on the persistence or level of disease. However, within a critical range of group sizes just below this threshold level, external infection becomes much more important in determining disease dynamics. Within this critical range, external infection increases the ratio of intra- to inter-group infections due to the greater probability of external infections entering fully-susceptible groups. The effect is to enable bTB persistence and increase bTB prevalence in badger populations which would not be able to maintain bTB based on internal infection alone. Conclusions External sources of bTB infection can contribute to the persistence of bTB in badger populations. In high-density badger populations, internal badger-derived infections occur at a sufficient rate that the additional effect of external sources in exacerbating disease is minimal. However, in lower-density populations, external sources of infection are much more important in enhancing bTB prevalence and persistence. In such circumstances, it is particularly important that control strategies to

  17. Impact of external sources of infection on the dynamics of bovine tuberculosis in modelled badger populations.

    Science.gov (United States)

    Hardstaff, Joanne L; Bulling, Mark T; Marion, Glenn; Hutchings, Michael R; White, Piran C L

    2012-06-27

    The persistence of bovine TB (bTB) in various countries throughout the world is enhanced by the existence of wildlife hosts for the infection. In Britain and Ireland, the principal wildlife host for bTB is the badger (Meles meles). The objective of our study was to examine the dynamics of bTB in badgers in relation to both badger-derived infection from within the population and externally-derived, trickle-type, infection, such as could occur from other species or environmental sources, using a spatial stochastic simulation model. The presence of external sources of infection can increase mean prevalence and reduce the threshold group size for disease persistence. Above the threshold equilibrium group size of 6-8 individuals predicted by the model for bTB persistence in badgers based on internal infection alone, external sources of infection have relatively little impact on the persistence or level of disease. However, within a critical range of group sizes just below this threshold level, external infection becomes much more important in determining disease dynamics. Within this critical range, external infection increases the ratio of intra- to inter-group infections due to the greater probability of external infections entering fully-susceptible groups. The effect is to enable bTB persistence and increase bTB prevalence in badger populations which would not be able to maintain bTB based on internal infection alone. External sources of bTB infection can contribute to the persistence of bTB in badger populations. In high-density badger populations, internal badger-derived infections occur at a sufficient rate that the additional effect of external sources in exacerbating disease is minimal. However, in lower-density populations, external sources of infection are much more important in enhancing bTB prevalence and persistence. In such circumstances, it is particularly important that control strategies to reduce bTB in badgers include efforts to minimise such

  18. Diagnostics for electrical discharge light sources : pushing the limits

    NARCIS (Netherlands)

    Zissis, G.; Haverlag, M.

    2010-01-01

    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

  19. National Synchrotron Light Source: vacuum system for National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Schuchman, J.C.; Godel, J.B.; Jordan, W.; Oversluizen, T.

    1978-01-01

    The National Synchrotron Light Source (NSLS), a 24 million dollar project under construction at Brookhaven National Laboratory (BNL), is a research facility dedicated to the production of synchrotron radiation. Synchrotron radiation is that radiation produced by the acceleration of charged particles at near the speed of light. This facility will provide a continuous spectrum of radiation from the vacuum ultraviolet to the hard x-ray range. The radiation will be highly intense, 100% polarized, extremely well collimated and will have a pulsed time structure. The radiation will be produced in two electron storage rings at energies of 700 MeV and 2.5 GeV, respectively. A maximum of one ampere at 2 GeV, or one-half ampere at 2.5 GeV, of electron beam will be stored

  20. Robust photometric stereo using structural light sources

    Science.gov (United States)

    Han, Tian-Qi; Cheng, Yue; Shen, Hui-Liang; Du, Xin

    2014-05-01

    We propose a robust photometric stereo method by using structural arrangement of light sources. In the arrangement, light sources are positioned on a planar grid and form a set of collinear combinations. The shadow pixels are detected by adaptive thresholding. The specular highlight and diffuse pixels are distinguished according to their intensity deviations of the collinear combinations, thanks to the special arrangement of light sources. The highlight detection problem is cast as a pattern classification problem and is solved using support vector machine classifiers. Considering the possible misclassification of highlight pixels, the ℓ1 regularization is further employed in normal map estimation. Experimental results on both synthetic and real-world scenes verify that the proposed method can robustly recover the surface normal maps in the case of heavy specular reflection and outperforms the state-of-the-art techniques.

  1. Random matrix theory with an external source

    CERN Document Server

    Brézin, Edouard

    2016-01-01

    This is a first book to show that the theory of the Gaussian random matrix is essential to understand the universal correlations with random fluctuations and to demonstrate that it is useful to evaluate topological universal quantities. We consider Gaussian random matrix models in the presence of a deterministic matrix source. In such models the correlation functions are known exactly for an arbitrary source and for any size of the matrices. The freedom given by the external source allows for various tunings to different classes of universality. The main interest is to use this freedom to compute various topological invariants for surfaces such as the intersection numbers for curves drawn on a surface of given genus with marked points, Euler characteristics, and the Gromov–Witten invariants. A remarkable duality for the average of characteristic polynomials is essential for obtaining such topological invariants. The analysis is extended to nonorientable surfaces and to surfaces with boundaries.

  2. High-brightness electron guns for linac-based light sources

    International Nuclear Information System (INIS)

    Lewellen, J.W.

    2004-01-01

    Most proposed linac-based light sources, such as single-pass free-electron lasers and energy-recovery-linacs, require very high-brightness electron beams in order to achieve their design performance. These beam requirements must be achieved not on an occasional basis, but rather must be met by every bunch produced by the source over extended periods of time. It is widely assumed that the beam source will be a photocathode electron gun; the selection of accelerator technique (e.g., dc or rf) for the gun is more dependent on the application.The current state of the art of electron beam production is adequate but not ideal for the first generation of linac-based light sources, such as the Linac Coherent Light Source (LCLS) x-ray free-electron laser (X-FEL). For the next generation of linac-based light sources, an order of magnitude reduction in the transverse electron beam emittance is required to significantly reduce the cost of the facility. This is beyond the present state of the art, given the other beam properties that must be maintained. The requirements for current and future linac-based light source beam sources are presented here, along with a review of the present state of the art. A discussion of potential paths towards meeting future needs is presented at the conclusion.

  3. First light of an external occulter testbed at flight Fresnel numbers

    Science.gov (United States)

    Kim, Yunjong; Sirbu, Dan; Hu, Mia; Kasdin, Jeremy; Vanderbei, Robert J.; Harness, Anthony; Shaklan, Stuart

    2017-01-01

    Many approaches have been suggested over the last couple of decades for imaging Earth-like planets. One of the main candidates for creating high-contrast for future Earth-like planets detection is an external occulter. The external occulter is a spacecraft flown along the line-of-sight of a space telescope to suppress starlight and enable high-contrast direct imaging of exoplanets. The occulter is typically tens of meters in diameter and the separation from the telescope is of the order of tens of thousands of kilometers. Optical testing of a full-scale external occulter on the ground is impossible because of the long separations. Therefore, laboratory verification of occulter designs is necessary to validate the optical models used to design and predict occulter performance. At Princeton, we have designed and built a testbed that allows verification of scaled occulter designs whose suppressed shadow is mathematically identical to that of space occulters. The goal of this experiment is to demonstrate a pupil plane suppression of better than 1e-9 with a corresponding image plane contrast of better than 1e-11. The occulter testbed uses a 77.2 m optical propagation distance to realize the flight Fresnel number of 14.5. The scaled mask is placed at 27.2 m from the artificial source and the camera is located 50.0 m from the scaled mask. We will use an etched silicon mask, manufactured by the Microdevices Lab(MDL) of the Jet Propulsion Laboratory(JPL), as the occulter. Based on conversations with MDL, we expect that 0.5 μm feature size is an achievable resolution in the mask manufacturing process and is therefore likely the indicator of the best possible performance. The occulter is illuminated by a diverging laser beam to reduce the aberrations from the optics before the occulter. Here, we present first light result of a sample design operating at a flight Fresnel number and the experimental setup of the testbed. We compare the experimental results with simulations

  4. Inverse kinetics for subcritical systems with external neutron source

    International Nuclear Information System (INIS)

    Carvalho Gonçalves, Wemerson de; Martinez, Aquilino Senra; Carvalho da Silva, Fernando

    2017-01-01

    Highlights: • It was developed formalism for reactivity calculation. • The importance function is related to the system subcriticality. • The importance function is also related with the value of the external source. • The equations were analyzed for seven different levels of sub criticality. • The results are physically consistent with others formalism discussed in the paper. - Abstract: Nuclear reactor reactivity is one of the most important properties since it is directly related to the reactor control during the power operation. This reactivity is influenced by the neutron behavior in the reactor core. The time-dependent neutrons behavior in response to any change in material composition is important for the reactor operation safety. Transient changes may occur during the reactor startup or shutdown and due to accidental disturbances of the reactor operation. Therefore, it is very important to predict the time-dependent neutron behavior population induced by changes in neutron multiplication. Reactivity determination in subcritical systems driven by an external neutron source can be obtained through the solution of the inverse kinetics equation for subcritical nuclear reactors. The main purpose of this paper is to find the solution of the inverse kinetics equation the main purpose of this paper is to device the inverse kinetics equations for subcritical systems based in a previous paper published by the authors (Gonçalves et al., 2015) and by (Gandini and Salvatores, 2002; Dulla et al., 2006). The solutions of those equations were also obtained. Formulations presented in this paper were tested for seven different values of k eff with external neutrons source constant in time and for a powers ratio varying exponentially over time.

  5. Femtosecond Light Source for Phase-Controlled Multiphoton Ionization

    International Nuclear Information System (INIS)

    Sokolov, A. V.; Walker, D. R.; Yavuz, D. D.; Yin, G. Y.; Harris, S. E.

    2001-01-01

    We describe a femtosecond Raman light source with more than an octave of optical bandwidth. We use this source to demonstrate phase control of multiphoton ionization under conditions where ionization requires eleven photons of the lowest frequency of the spectrum or five photons of the highest frequency. The nonlinearity of the photoionization process allows us to characterize the light source. Experiment-to-theory comparison implies generation of a near single-cycle waveform

  6. Assessment of occupational exposure due to external sources of radiation. Safety guide

    International Nuclear Information System (INIS)

    2000-01-01

    Occupational exposure to ionizing radiation can occur in a range of industries, medical institutions, educational and research establishments and nuclear fuel cycle facilities. Adequate radiation protection of workers is essential for the safe and acceptable use of radiation, radioactive materials and nuclear energy. The three Safety Guides on occupational radiation protection are jointly sponsored by the IAEA and the International Labour Office. The Agency gratefully acknowledges the contribution of the European Commission to the development of the present Safety Guide. The present Safety Guide addresses the assessment of exposure due to external sources of radiation in the workplace. Such exposure can result from a number of sources within a workplace, and the monitoring of workers and the workplace in such situations is an integral part of any occupational radiation protection programme. The assessment of exposure due to external radiation sources depends critically upon knowledge of the radiation type and energy and the conditions of exposure. The present Safety Guide reflects the major changes over the past decade in international practice in external dose assessment

  7. Assessment of occupational exposure due to external sources of radiation. Safety guide

    International Nuclear Information System (INIS)

    2004-01-01

    Occupational exposure to ionizing radiation can occur in a range of industries, medical institutions, educational and research establishments and nuclear fuel cycle facilities. Adequate radiation protection of workers is essential for the safe and acceptable use of radiation, radioactive materials and nuclear energy. The three Safety Guides on occupational radiation protection are jointly sponsored by the IAEA and the International Labour Office. The Agency gratefully acknowledges the contribution of the European Commission to the development of the present Safety Guide. The present Safety Guide addresses the assessment of exposure due to external sources of radiation in the workplace. Such exposure can result from a number of sources within a workplace, and the monitoring of workers and the workplace in such situations is an integral part of any occupational radiation protection programme. The assessment of exposure due to external radiation sources depends critically upon knowledge of the radiation type and energy and the conditions of exposure. The present Safety Guide reflects the major changes over the past decade in international practice in external dose assessment

  8. Assessment of occupational exposure due to external sources of radiation. Safety guide

    International Nuclear Information System (INIS)

    1999-01-01

    Occupational exposure to ionizing radiation can occur in a range of industries, medical institutions, educational and research establishments and nuclear fuel cycle facilities. Adequate radiation protection of workers is essential for the safe and acceptable use of radiation, radioactive materials and nuclear energy. The three Safety Guides on occupational radiation protection are jointly sponsored by the IAEA and the International Labour Office. The Agency gratefully acknowledges the contribution of the European Commission to the development of the present Safety Guide. The present Safety Guide addresses the assessment of exposure due to external sources of radiation in the workplace. Such exposure can result from a number of sources within a workplace, and the monitoring of workers and the workplace in such situations is an integral part of any occupational radiation protection programme. The assessment of exposure due to external radiation sources depends critically upon knowledge of the radiation type and energy and the conditions of exposure. The present Safety Guide reflects the major changes over the past decade in international practice in external dose assessment

  9. DUV light source sustainability achievements and next steps

    Science.gov (United States)

    Roman, Yzzer; Cacouris, Ted; Raju, Kumar Raja Guvindan; Kanawade, Dinesh; Gillespie, Walt; Luo, Siqi; Mason, Eric; Manley, David; Das, Saptaparna

    2018-03-01

    Key sustainability opportunities have been executed in support of corporate initiatives to reduce the environmental footprint and decrease the running cost of DUV light sources. Previously, substantial neon savings were demonstrated over several years through optimized gas management technologies. Beyond this work, Cymer is developing the XLGR 100, a self-contained neon recycling system, to enable minimal gas consumption. The high efficiency results of the XLGR 100 in a production factory are validated in this paper. Cymer has also developed new light source modules with 33% longer life in an effort to reduce raw and associated resource consumption. In addition, a progress report is included regarding the improvements developed to reduce light source energy consumption.

  10. A geography of moral hazard: sources and sinks of motor-vehicle commuting externalities.

    Science.gov (United States)

    Yiannakoulias, Niko; Bland, Widmer; Scott, Darren M

    2014-09-01

    Motor-vehicles are responsible for harms to health that are not directly experienced by individual drivers - such as air pollution and risk of injury to pedestrians. In addition to their direct effects on health, these harms also represent a moral hazard since drivers are not required to consider their effects as part of their decision to drive. We describe an approach for estimating sources of motor-vehicle commuter externalities as a means of understanding the geography of moral hazard, and in particular, the spatial displacement of negative health externalities associated with motor-vehicle commuting. This approach models motor-vehicle commuter traffic flow by trip origin for small geographic areas within the City of Toronto, Ontario. We find that most health-related externalities associated with motor-vehicle commuters are not locally generated, with a large share coming from outside Toronto. Low income is associated with externalities originating outside the municipal boundary, but not with locally sourced externalities. We discuss the impact of geographical moral hazard on the agency of citizens as well as policy options aimed at addressing motor-vehicle externalities. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. GPC light shaping a supercontinuum source

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...... 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...

  12. Toward a fourth-generation light source

    International Nuclear Information System (INIS)

    Moncton, D. E.

    1999-01-01

    Historically, x-ray research has been propelled by the existence of urgent and compelling scientific questions and the push of powerful and exquisite source technology. These two factors have gone hand in hand since Rontgen discovered x-rays. Here we review the progress being made with existing third-generation synchrotron-radiation light sources and the prospects for a fourth-generation light source with dramatically improved laser-like beam characteristics. The central technology for high-brilliance x-ray beams is the x-ray undulator, a series of alternating-pole magnets situated above and below the particle beam. When the particle beam is oscillated by the alternating magnetic fields, a set of. interacting and interfering wave fronts is produced, which leads to an x-ray beam with extraordinary properties. Third-generation sources of light in the hard x-ray range have been constructed at three principal facilities: the European Synchrotrons Radiation Facility (ESRF) in France; the Super Photon Ring 8-GeV (or Spring-8) in Japan; and the Advanced Photon Source (APS) in the US. Undulator technology is also used on a number of low-energy machines for radiation in the ultraviolet and soft x-ray regimes. At the APS, these devices exceed all of our original expectations for beam brilliance, tunability, spectral range, and operational flexibility. Shown in Fig. 1 are the tuning curves of the first few harmonics, showing x-ray production from a few kV to better than 40 keV. High-brilliance radiation extends to over 100 keV

  13. 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.

  14. 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.

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

    International Nuclear Information System (INIS)

    Schlachter, F.; Robinson, A.

    1996-01-01

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

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

    International Nuclear Information System (INIS)

    Schlachter, F.; Robinson, A.

    1996-01-01

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

  17. New Storage Ring Light Sources on the Horizon

    CERN Document Server

    Podobedov, Boris

    2005-01-01

    The world's appetite for light sources keeps growing as new ones are under construction or being proposed for every continent but Antarctica. While some viable alternatives are emerging, the great majority of new light sources are based on mature electron storage ring technology. We review the design and performance of the new machines worldwide and speculate on the future directions.

  18. 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

  19. Generation of more than 300 mW diffraction-limited light at 405 nm by second-harmonic generation of a tapered diode laser with external cavity feedback

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Holm, J.; Sumpf, B.

    2007-01-01

    We have constructed a blue laser source consisting of a single-frequency tapered diode laser with external cavity feedback that is frequency doubled by a quasi-phase matched KTP (PPKTP) in a bowtie ring cavity and extract more than 360 mW of power at 405 nm. The conversion efficiency from...... fundamental laser power to second harmonic power is 35 %, while it is 64 % from coupled fundamental power to extracted blue light. Thermal effects and gray tracking set an upper limit on the amount of generated blue light....

  20. Radioactive starting aids for electrodeless light sources

    International Nuclear Information System (INIS)

    Proud, J.M.; Regan, R.J.; Haugsjaa, P.O.; Baird, D.H.

    1980-01-01

    The use of radioactive sources of α particles, β particles or γ rays as aids in starting a discharge in an electrodeless light source is discussed. The advantages of siting the sources at various positions in the device are discussed. Preferred materials are 85 Kr and 241 Am. (U.K.)

  1. CENTRAL WAVELENGTH ADJUSTMENT OF LIGHT EMITTING SOURCE IN INTERFEROMETRIC SENSORS BASED ON FIBER-OPTIC BRAGG GRATINGS

    Directory of Open Access Journals (Sweden)

    A. S. Aleynik

    2015-09-01

    Full Text Available The paper is focused on the investigation of fiber-optic interferometric sensor based on the array of fiber Bragg gratings. Reflection spectra displacement mechanism of the fiber Bragg gratings under the external temperature effects and the static pressure is described. The experiment has shown that reflection spectra displacement of Bragg gratings reduces the visibility of the interference pattern. A method of center wavelength adjustment is proposed for the optical radiation source in accord ance with the current Bragg gratings reflection spectra based on the impulse relative modulation of control signal for the Peltier element controller. The semiconductor vertical-cavity surface-emitting laser controlled by a pump driver is used as a light source. The method is implemented by the Peltier element controller regulating and stabilizing the light source temperature, and a programmable logic-integrated circuit monitoring the Peltier element controller. The experiment has proved that the proposed method rendered possible to regulate the light source temperature at a pitch of 0.05 K and adjust the optical radiation source center wavelength at a pitch of 0.05 nm. Experimental results have revealed that the central wavelength of the radiation adjustment at a pitch of 0.005 nm gives the possibility for the capacity of the array consisting of four opticalfiber sensors based on the fiber Bragg gratings. They are formed in one optical fiber under the Bragg grating temperature change from 0° C to 300° C and by the optical fiber mechanical stretching by the force up to 2 N.

  2. Polarized Light Sources for photocathode electron guns at SLAC

    International Nuclear Information System (INIS)

    Woods, M.; Frisch, J.; Witte, K.; Zolotorev, M.

    1992-12-01

    We describe current and future Polarized Light Sources at SLAC for use with photocathode electron guns to produce polarized electron beams. The SLAC experiments SLD and E142 are considered, and are used to define the required parameters for the Polarized Light Sources

  3. Investigation of rf plasma light sources for dye laser excitation

    International Nuclear Information System (INIS)

    Kendall, J.S.; Jaminet, J.F.

    1975-06-01

    Analytical and experimental studies were performed to assess the applicability of radio frequency (rf) induction heated plasma light sources for potential excitation of continuous dye lasers. Experimental efforts were directed toward development of a continuous light source having spectral flux and emission characteristics approaching that required for pumping organic dye lasers. Analytical studies were performed to investigate (1) methods of pulsing the light source to obtain higher radiant intensity and (2) methods of integrating the source with a reflective cavity for pumping a dye cell. (TFD)

  4. Knowledge-sourcing of R&D workers in different job positions: contextualising external personal knowledge networks

    OpenAIRE

    Huber, Franz

    2013-01-01

    This paper systematically examines the role of external personal knowledge networks vis-à-vis alternative sources of work-related knowledge. Specific hypotheses on whether the importance of external personal networks vary for job positions, knowledge functions and sources of competitiveness are examined. The study is based on a survey and interviews with 105 R&D workers in 46 Information Technology (IT) firms in the Greater Cambridge Region (UK).The results show that alternative sources o...

  5. MD 400: LHC emittance growth in presence of an external source of noise during collision

    CERN Document Server

    Barranco Garcia, Javier; Pieloni, Tatiana; Tambasco, Claudia; Trad, Georges; Valuch, Daniel; Betz, Michael; Wendt, Manfred; Pojer, Mirko; Solfaroli Camillocci, Matteo; Salvachua Ferrando, Belen Maria; Fuchsberger, Kajetan; Albert, Markus; Qiang, Ji; CERN. Geneva. ATS Department

    2016-01-01

    The interplay between head-on beam-beam interaction and external sources of noise can be a significant source of emittance growth, especially when considering large beam-beam tune shifts as for the HL-LHC upgrade project. In this experiment the emittance growth of colliding bunches with different brightness and therefore different beam-beam parameters in the presence of an external white noise source with different amplitudes is measured for different gains of the transverse feedback.

  6. 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.

  7. Photobiocatalytic alcohol oxidation using LED light sources

    NARCIS (Netherlands)

    Rauch, M.C.R.; Schmidt, S.; Arends, I.W.C.E.; oppelt, K.; Kara, S; Hollmann, F.

    2016-01-01

    The photocatalytic oxidation of NADH using a flavin photocatalyst and a simple blue LED light source is reported. This in situ NAD+ regeneration system can be used to promote biocatalytic, enantioselective oxidation reactions. Compared to the traditional use of white light bulbs this method enables

  8. 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...... the Bragg reflector. Numerical simulations show that both the silicon light source and the VCSEL exploiting SOI grating mirrors have superior performances, compared to existing silicon light sources and long wavelength VCSELs. These devices are highly adequate for chip-level optical interconnects as well...

  9. Conversion degrees of resin composites using different light sources.

    Science.gov (United States)

    Ozturk, Bora; Cobanoglu, Nevin; Cetin, Ali Rıza; Gunduz, Beniz

    2013-01-01

    The objective of this study was to compare the conversion degree of six different composite materials (Filtek Z 250, Filtek P60, Spectrum TPH, Pertac II, Clearfil AP-X, and Clearfil Photo Posterior) using three different light sources (blue light-emitting diode [LED], plasma arc curing [PAC], and conventional halogen lamp [QTH]). Composites were placed in a 2 mm thick and 5 mm diameter Teflon molds and light cured from the top using three methods: LED for 40 s, PAC for 10 s, and QTH for 40 s. A Fourier Transform Infrared Spectroscopy (FTIR) was used to evaluate the degree of conversion (DC) (n=5). The results were analyzed with two-way analysis of variance and Tukey HSD test. DC was significantly influenced by two variables, light source and composite (PDC values than LED (PDC values of QTH and PAC or between DC values of LED and PAC (P>.05). The highest DC was observed in the Z 250 composite specimens following photopolymerization with QTH (70%). The lowest DC was observed in Clearfil Photo Posterior composite specimens following photo-polymerization with LED (43%). The DC was found to be changing according to both light sources and composite materials used. Conventional light halogen (QTH) from light sources and Filtek Z 250 and Filtek P 60 among composite materials showed the most DC performance.

  10. Light source distribution and scattering phase function influence light transport in diffuse multi-layered media

    Science.gov (United States)

    Vaudelle, Fabrice; L'Huillier, Jean-Pierre; Askoura, Mohamed Lamine

    2017-06-01

    Red and near-Infrared light is often used as a useful diagnostic and imaging probe for highly scattering media such as biological tissues, fruits and vegetables. Part of diffusively reflected light gives interesting information related to the tissue subsurface, whereas light recorded at further distances may probe deeper into the interrogated turbid tissues. However, modelling diffusive events occurring at short source-detector distances requires to consider both the distribution of the light sources and the scattering phase functions. In this report, a modified Monte Carlo model is used to compute light transport in curved and multi-layered tissue samples which are covered with a thin and highly diffusing tissue layer. Different light source distributions (ballistic, diffuse or Lambertian) are tested with specific scattering phase functions (modified or not modified Henyey-Greenstein, Gegenbauer and Mie) to compute the amount of backscattered and transmitted light in apple and human skin structures. Comparisons between simulation results and experiments carried out with a multispectral imaging setup confirm the soundness of the theoretical strategy and may explain the role of the skin on light transport in whole and half-cut apples. Other computational results show that a Lambertian source distribution combined with a Henyey-Greenstein phase function provides a higher photon density in the stratum corneum than in the upper dermis layer. Furthermore, it is also shown that the scattering phase function may affect the shape and the magnitude of the Bidirectional Reflectance Distribution (BRDF) exhibited at the skin surface.

  11. UV emissions from low energy artificial light sources.

    Science.gov (United States)

    Fenton, Leona; Moseley, Harry

    2014-01-01

    Energy efficient light sources have been introduced across Europe and many other countries world wide. The most common of these is the Compact Fluorescent Lamp (CFL), which has been shown to emit ultraviolet (UV) radiation. Light Emitting Diodes (LEDs) are an alternative technology that has minimal UV emissions. This brief review summarises the different energy efficient light sources available on the market and compares the UV levels and the subsequent effects on the skin of normal individuals and those who suffer from photodermatoses. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Fiber-Based Lasers as an Option for GRACE Follow-On Light Source

    Science.gov (United States)

    Camp, Jordan

    2010-01-01

    Fiber based lasers offer a number of attractive characteristics for space application: state of the art laser technology, leverage of design and reliability from the substantial investments of the telecon industry, and convenient redundancy of higher risk components through fiber splicing. At NASA/Goddard we are currently investigating three GFO fiber-based laser options: a fiber oscillator built in our laboratory; an effort to space qualify a commercial design that uses a proprietary high-gain fiber cavity; and the space qualification of a promising new commercial external cavity laser, notable for its low-mass, compact design. In my talk I will outline these efforts, and suggest that the GFO Project may soon have the option of a US laser vendor for its light source.

  13. Applicability of a desiccant dew-point cooling system independent of external water sources

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Kærn, Martin Ryhl

    2015-01-01

    The applicability of a technical solution for making desiccant cooling systems independent of external water sources is investigated. Water is produced by condensing the desorbed water vapour in a closed regeneration circuit. Desorbed water recovery is applied to a desiccant dew-point cooling...... system, which includes a desiccant wheel and a dew point cooler. The system is simulated during the summer period in the Mediterranean climate of Rome and it results completely independent of external water sources. The seasonal thermal COP drops 8% in comparison to the open regeneration circuit solution...

  14. The advanced light source: America's brightest light for science and industry

    International Nuclear Information System (INIS)

    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

  15. Multi-wavelength mid-IR light source for gas sensing

    Science.gov (United States)

    Karioja, Pentti; Alajoki, Teemu; Cherchi, Matteo; Ollila, Jyrki; Harjanne, Mikko; Heinilehto, Noora; Suomalainen, Soile; Viheriälä, Jukka; Zia, Nouman; Guina, Mircea; Buczyński, Ryszard; Kasztelanic, Rafał; Kujawa, Ireneusz; Salo, Tomi; Virtanen, Sami; Kluczyński, Paweł; Sagberg, Hâkon; Ratajczyk, Marcin; Kalinowski, Przemyslaw

    2017-02-01

    Cost effective multi-wavelength light sources are key enablers for wide-scale penetration of gas sensors at Mid-IR wavelength range. Utilizing novel Mid-IR Si-based photonic integrated circuits (PICs) filter and wide-band Mid-IR Super Luminescent Light Emitting Diodes (SLEDs), we show the concept of a light source that covers 2.5…3.5 μm wavelength range with a resolution of price can be lowered in high volumes by utilizing tailored molded IR lens technology and automated packaging and assembling technologies. The status of the development of the key components of the light source are reported. The PIC is based on the use of micron-scale SOI technology, SLED is based on AlGaInAsSb materials and the lenses are tailored heavy metal oxide glasses fabricated by the use of hot-embossing. The packaging concept utilizing automated assembly tools is depicted. In safety and security applications, the Mid-IR wavelength range covered by the novel light source allows for detecting several harmful gas components with a single sensor. At the moment, affordable sources are not available. The market impact is expected to be disruptive, since the devices currently in the market are either complicated, expensive and heavy instruments, or the applied measurement principles are inadequate in terms of stability and selectivity.

  16. Diamond Light Source - A Next Generation SR Facility

    International Nuclear Information System (INIS)

    Materlik, G.

    2004-01-01

    After the very successful start and the by now almost 10 years operation of the 3rd generation x-ray sources ESRF, APS and Spring-8 smaller storage rings are being planned and constructed with properties emphasising applications with photon energies around the 10 keV spectral region. In the UK the Government and the medical foundation Wellcome Trust have decided to build the Diamond Light Source Facility in the South of Oxfordshire right next to the Rutherford Appleton Laboratory. The joint venture company Diamond Light Source Limited has been created to plan, construct, and operate this facility. (author)

  17. Direction-division multiplexed holographic free-electron-driven light sources

    Science.gov (United States)

    Clarke, Brendan P.; MacDonald, Kevin F.; Zheludev, Nikolay I.

    2018-01-01

    We report on a free-electron-driven light source with a controllable direction of emission. The source comprises a microscopic array of plasmonic surface-relief holographic domains, each tailored to direct electron-induced light emission at a selected wavelength into a collimated beam in a prescribed direction. The direction-division multiplexed source is tested by driving it with the 30 kV electron beam of a scanning electron microscope: light emission, at a wavelength of 800 nm in the present case, is switched among different output angles by micron-scale repositioning of the electron injection point among domains. Such sources, with directional switching/tuning possible at picosecond timescales, may be applied to field-emission and surface-conduction electron-emission display technologies, optical multiplexing, and charged-particle-beam position metrology.

  18. 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....

  19. Ocular exposure to ultraviolet and visible radiation from light sources

    International Nuclear Information System (INIS)

    Hietanen, M.

    1992-01-01

    Exposure of the eyes to UV radiation and blue light of artificial light sources and the sun was evaluated. A spectroradiometer was used to determine the spectral irradiance at 1 nm intervals from 250 to 800 nm. Various groups of workers are at risk of ocular over-exposure to optical radiation, outdoor workers maintenance personnel of bright light source as and wear eye-protectors with effective filtering of UV radiation and blue light. (author)

  20. 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...

  1. A comparison of color fidelity metrics for light sources using simulation of color samples under lighting conditions

    Science.gov (United States)

    Kwon, Hyeokjun; Kang, Yoojin; Jang, Junwoo

    2017-09-01

    Color fidelity has been used as one of indices to evaluate the performance of light sources. Since the Color Rendering Index (CRI) was proposed at CIE, many color fidelity metrics have been proposed to increase the accuracy of the metric. This paper focuses on a comparison of the color fidelity metrics in an aspect of accuracy with human visual assessments. To visually evaluate the color fidelity of light sources, we made a simulator that reproduces the color samples under lighting conditions. In this paper, eighteen color samples of the Macbeth color checker under test light sources and reference illuminant for each of them are simulated and displayed on a well-characterized monitor. With only a spectrum set of the test light source and reference illuminant, color samples under any lighting condition can be reproduced. In this paper, the spectrums of the two LED and two OLED light sources that have similar values of CRI are used for the visual assessment. In addition, the results of the visual assessment are compared with the two color fidelity metrics that include CRI and IES TM-30-15 (Rf), proposed by Illuminating Engineering Society (IES) in 2015. Experimental results indicate that Rf outperforms CRI in terms of the correlation with visual assessment.

  2. 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.

  3. Advanced Light Source Activity Report 2002

    International Nuclear Information System (INIS)

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

    2003-01-01

    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. Advanced Light Source beam diagnostics systems

    International Nuclear Information System (INIS)

    Hinkson, J.

    1993-10-01

    The Advanced Light Source (ALS), a third-generation synchrotron light source, has been recently commissioned. Beam diagnostics were very important to the success of the operation. Each diagnostic system is described in this paper along with detailed discussion of its performance. Some of the systems have been in operation for two years. Others, in the storage ring, have not yet been fully commissioned. These systems were, however, working well enough to provide the essential information needed to store beam. The devices described in this paper include wall current monitors, a beam charge monitor, a 50 ohm Faraday cup, DC current transformers, broad-hand striplines, fluorescence screens, beam collimators and scrapers, and beam position monitors. Also, the means by which waveforms are digitized and displayed in the control room is discussed

  5. Phosphor converted laser diode light source for endoscopic diagnostics

    DEFF Research Database (Denmark)

    Krasnoshchoka, Anastasiia; Thorseth, Anders; Dam-Hansen, Carsten

    2017-01-01

    of the generated white light into thin optical fibres. The development involves designing optics for optimizing the light extraction efficiency and guiding of light to the area of interest. In this paper we compared the developed light source to the current standard in endoscopy – xenon arc lamps. Detailed...

  6. Plasmonics for solid-state lighting : enhanced excitation and directional emission of highly efficient light sources

    NARCIS (Netherlands)

    Lozano, G.; Louwers, Davy J.; Rodriguez, S.R.K.; Murai, S.; Jansen, O.T.A.; Verschuuren, M.A.; Gomez Rivas, J.

    2013-01-01

    Light sources based on reliable and energy-efficient light-emitting diodes (LEDs) are instrumental in the development of solid-state lighting (SSL). Most research efforts in SSL have focused on improving both the intrinsic quantum efficiency (QE) and the stability of light emitters. For this reason,

  7. The Effects of Different External Carbon Sources on Nitrous Oxide Emissions during Denitrification in Biological Nutrient Removal Processes

    Science.gov (United States)

    Hu, Xiang; Zhang, Jing; Hou, Hongxun

    2018-01-01

    The aim of this study was to investigate the effects of two different external carbon sources (acetate and ethanol) on the nitrous oxide (N2O) emissions during denitrification in biological nutrient removal processes. Results showed that external carbon source significantly influenced N2O emissions during the denitrification process. When acetate served as the external carbon source, 0.49 mg N/L and 0.85 mg N/L of N2O was produced during the denitrificaiton processes in anoxic and anaerobic/anoxic experiments, giving a ratio of N2O-N production to TN removal of 2.37% and 4.96%, respectively. Compared with acetate, the amount of N2O production is negligible when ethanol used as external carbon addition. This suggested that ethanol is a potential alternative external carbon source for acetate from the point of view of N2O emissions.

  8. Parallel Beam Dynamics Simulation Tools for Future Light Source Linac Modeling

    International Nuclear Information System (INIS)

    Qiang, Ji; Pogorelov, Ilya v.; Ryne, Robert D.

    2007-01-01

    Large-scale modeling on parallel computers is playing an increasingly important role in the design of future light sources. Such modeling provides a means to accurately and efficiently explore issues such as limits to beam brightness, emittance preservation, the growth of instabilities, etc. Recently the IMPACT codes suite was enhanced to be applicable to future light source design. Simulations with IMPACT-Z were performed using up to one billion simulation particles for the main linac of a future light source to study the microbunching instability. Combined with the time domain code IMPACT-T, it is now possible to perform large-scale start-to-end linac simulations for future light sources, including the injector, main linac, chicanes, and transfer lines. In this paper we provide an overview of the IMPACT code suite, its key capabilities, and recent enhancements pertinent to accelerator modeling for future linac-based light sources

  9. X-ray micro-Tomography at the Advanced Light Source

    Science.gov (United States)

    The X-ray micro-Tomography Facility at the Advanced Light Source has been in operation since 2004. The source is a superconducting bend magnet of critical energy 10.5KeV; photon energy coverage is 8-45 KeV in monochromatic mode, and a filtered white light option yields useful photons up to 50 KeV. A...

  10. Electrical discharge light sources: a challenge for the future

    International Nuclear Information System (INIS)

    Zissis, G.

    2001-01-01

    The first electric powder lamp operated that 150 years ago, since then the evolution of light sources is astonishing. Today, more than 10 % of the global electric power produced worldwide serve fore light production from several billions lamps. Since last three decades incandescent lamps are gradually replaced by more energy efficient discharge lamps. In parallel, new generation of light emitting diodes, producing bright colours (including white) with luminous efficacy challenging even discharge lamps, appeared in past years. The objective of this paper is to focus on the state of art in the domain of light sources and discuss the challenges for the near future. (author)

  11. Extracting the emitter orientation in organic light-emitting diodes from external quantum efficiency measurements

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Tobias D., E-mail: Tobias.Schmidt@physik.uni-augsburg.de; Reichardt, Lukas J.; Wehrmeister, Sebastian; Scholz, Bert J.; Mayr, Christian; Brütting, Wolfgang, E-mail: Wolfgang.Bruetting@physik.uni-augsburg.de [Institute of Physics, University of Augsburg, 86135 Augsburg (Germany); Rausch, Andreas F.; Wehlus, Thomas; Reusch, Thilo C. G. [OSRAM OLED GmbH, Wernerwerkstrasse 2, 93049 Regensburg (Germany); Ciarnáin, Rossá Mac; Danz, Norbert [Fraunhofer Institute for Applied Optics and Precision Engineering, 07745 Jena (Germany)

    2014-07-28

    Emitter orientation will play a major role in future applications of organic light-emitting diodes due to its strong impact on the efficiency of the devices. Up to now, determining the orientation of transition dipole moments required elaborate angular-dependent measurements of the light emission pattern. In this paper, we present a simplified and straightforward method to extract the emitter orientation from external quantum efficiency measurements. We demonstrate the validity of the method on three different dye-doped emitting systems.

  12. Large area, surface discharge pumped, vacuum ultraviolet light source

    Science.gov (United States)

    Sze, R.C.; Quigley, G.P.

    1996-12-17

    Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source is disclosed. A contamination-free VUV light source having a 225 cm{sup 2} emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm{sup 2} at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing. 3 figs.

  13. Biological infrared microspectroscopy at the National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Miller, Lisa M.; Carr, G. Lawrence; Williams, Gwyn P.; Sullivan, Michael; Chance, Mark R.

    2000-01-01

    Beamline U2B at the National Synchrotron Light Source has been designed and built as an infrared beamline dedicated to the study of biomedical problems. In 1997, the horizontal and vertical acceptances of Beamline U2B were increased in order to increase the overall flux of the beamline. A wedged, CVD diamond window separates the UHV vacuum of the VUV ring from the rough vacuum of the beamline. The endstation consists of a Nicolet Magna 860 step-scan FTIR and a NicPlan infrared microscope. The spectrometer is equipped with beamsplitter/detector combinations that permit data collection in the mid-and far-infrared regions. We have also made provisions for mounting an external detector (e.g. bolometer) for far infrared microspectroscopy. Thus far, Beamline U2B has been used to (1) perform chemical imaging of bone tissue and brain cells to address issues related to bone disease and epilepsy, respectively, and (2) examine time-resolved protein structure in the sub-millisecond folding of cytochrome c

  14. Noise analysis of a white-light supercontinuum light source for multiple wavelength confocal laser scanning fluorescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, Gail [Centre for Biophotonics, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow, G4 0NR (United Kingdom)

    2005-08-07

    Intensity correlations of a Ti : sapphire, Kr/Ar and a white-light supercontinuum were performed to quantify the typical signal amplitude fluctuations and hence ascertain the comparative output stability of the white-light supercontinuum source for confocal laser scanning microscopy (CLSM). Intensity correlations across a two-pixel sample (n = 1000) of up to 98%, 95% and 94% were measured for the Ti : sapphire, Kr/Ar and white-light supercontinuum source, respectively. The white-light supercontinuum noise level is therefore acceptable for CLSM, with the added advantage of wider wavelength flexibility over traditional CLSM excitation sources. The relatively low-noise white-light supercontinuum was then used to perform multiple wavelength sequential CLSM of guinea pig detrusor to confirm the reliability of the system and to demonstrate system flexibility.

  15. 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

  16. An Upgrade for the Advanced Light Source

    International Nuclear Information System (INIS)

    Chemla, Daniel S.; Feinberg, Benedict; Hussain, Zahid; Kirz, Janos; Krebs, Gary F.; Padmore, Howard A.; Robin, David S.; Robinson, Arthur L.; Smith, Neville V.

    2004-01-01

    One of the first third-generation synchrotron light sources, the ALS, has been operating for almost a decade at Berkeley Lab, where experimenters have been exploiting its high brightness for forefront science. However, accelerator and insertion-device technology have significantly changed since the ALS was designed. As a result, the performance of the ALS is in danger of being eclipsed by that of newer, more advanced sources. The ALS upgrade that we are planning includes full-energy, top-off injection with higher storage-ring current and the replacement of five first-generation insertion devices with nine state-of-the art insertion devices and four new application-specific beamlines now being identified in a strategic planning process. The upgrade will help keep the ALS at the forefront of soft x-ray synchrotron light sources for the next two decades

  17. Passivation of quartz for halogen-containing light sources

    Science.gov (United States)

    Falkenstein, Zoran

    1999-01-01

    Lifetime of halogen containing VUV, UV, visible or IR light sources can be extended by passivating the quartz or glass gas containers with halogens prior to filling the quartz with the halogen and rare gas mixtures used to produce the light.

  18. 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

  19. Advanced Light Source Activity Report 2000

    International Nuclear Information System (INIS)

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

    2001-01-01

    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

  20. 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.

  1. Large area UV light source with a semiconductor cathode

    International Nuclear Information System (INIS)

    Salamov, B. G.; Ciftci, Y. Oe.; Colakoglu, K.

    2002-01-01

    The light emission (LE) in the UV and visible (blue) range generated by a planar gas discharge system (PGDS) with a semiconductor cathode (SC) are studied. New light source offer high-intensity narrow-band emission at various UV and visible wavelengths (330 - 440 nm). Spectra in N 2 is presented, as well as intensity vs pressure curves for the main peaks of the spectrum. The use of source offers several advantages: PGDS can be extremely efficient energy converters transforming and amplifying a relatively low-powered photon flux incident on the receiving surface of the SC into a flux of high-energy particles over extended areas, i.e. electron, ions, photons. Thus, extremely bright UV and visible sources can be built. LE characteristics of the space in the PGDS are complex, depending on the emitting medium and species. By using the IR light to excite the SC of the system, we have shown that the discharge light emission (DLE) of the device with the N 2 in the gap can serve as an efficient source of the UV radiation if gas pressure and electric field are sufficiently high. This is realized due to the effect of the stabilisation of the spatially homogeneous mode of the discharge in a narrow gap with a large emitting area of SC. Special features of DLE render it highly promising for the development of sources with a large area of the emitting surface, high spatial uniformity of UV radiation, and fast dynamics of these devices. This low cost, high power light sources can provide an interesting alternative to conventional UV lamps

  2. DUV light source availability improvement via further enhancement of gas management technologies

    Science.gov (United States)

    Riggs, Daniel J.; O'Brien, Kevin; Brown, Daniel J. W.

    2011-04-01

    The continuous evolution of the semiconductor market necessitates ever-increasing improvements in DUV light source uptime as defined in the SEMI E10 standard. Cymer is developing technologies to exceed current and projected light source availability requirements via significant reduction in light source downtime. As an example, consider discharge chamber gas management functions which comprise a sizable portion of DUV light source downtime. Cymer's recent introduction of Gas Lifetime Extension (GLXTM) as a productivity improvement technology for its DUV lithography light sources has demonstrated noteworthy reduction in downtime. This has been achieved by reducing the frequency of full gas replenishment events from once per 100 million pulses to as low as once per 2 billion pulses. Cymer has continued to develop relevant technologies that target further reduction in downtime associated with light source gas management functions. Cymer's current subject is the development of technologies to reduce downtime associated with gas state optimization (e.g. total chamber gas pressure) and gas life duration. Current gas state optimization involves execution of a manual procedure at regular intervals throughout the lifetime of light source core components. Cymer aims to introduce a product enhancement - iGLXTM - that eliminates the need for the manual procedure and, further, achieves 4 billion pulse gas lives. Projections of uptime on DUV light sources indicate that downtime associated with gas management will be reduced by 70% when compared with GLX2. In addition to reducing downtime, iGLX reduces DUV light source cost of operation by constraining gas usage. Usage of fluorine rich Halogen gas mix has been reduced by 20% over GLX2.

  3. Solution of multi-element LED light sources development automation problem

    Science.gov (United States)

    Chertov, Aleksandr N.; Gorbunova, Elena V.; Korotaev, Valery V.; Peretyagin, Vladimir S.

    2014-09-01

    The intensive development of LED technologies resulted in the creation of multicomponent light sources in the form of controlled illumination devices based on usage of mentioned LED technologies. These light sources are used in different areas of production (for example, in the food industry for sorting products or in the textile industry for quality control, etc.). The use of LED lighting products in the devices used in specialized lighting, became possible due to wide range of colors of light, LED structures (which determines the direction of radiation, the spatial distribution and intensity of the radiation, electrical, heat, power and other characteristics), and of course, the possibility of obtaining any shade in a wide dynamic range of brightness values. LED-based lighting devices are notable for the diversity of parameters and characteristics, such as color radiation, location and number of emitters, etc. Although LED technologies have several advantages, however, they require more attention if you need to ensure a certain character of illumination distribution and/or distribution of the color picture at a predetermined distance (for example, at flat surface, work zone, area of analysis or observation). This paper presents software designed for the development of the multicomponent LED light sources. The possibility of obtaining the desired color and energy distribution at the zone of analysis by specifying the spatial parameters of the created multicomponent light source and using of real power, spectral and color parameters and characteristics of the LEDs is shown as well.

  4. 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...... bandwidth,high brightness and portability of a supercontinuum laser are all required. DTU Fotonik has now demonstrated the first optical fiber based broadband supercontinuum light souce, which covers 1.4-13.3μm and thereby most of the molecular fingerprint region....

  5. Visual color matching system based on RGB LED light source

    Science.gov (United States)

    Sun, Lei; Huang, Qingmei; Feng, Chen; Li, Wei; Wang, Chaofeng

    2018-01-01

    In order to study the property and performance of LED as RGB primary color light sources on color mixture in visual psychophysical experiments, and to find out the difference between LED light source and traditional light source, a visual color matching experiment system based on LED light sources as RGB primary colors has been built. By simulating traditional experiment of metameric color matching in CIE 1931 RGB color system, it can be used for visual color matching experiments to obtain a set of the spectral tristimulus values which we often call color-matching functions (CMFs). This system consists of three parts: a monochromatic light part using blazed grating, a light mixing part where the summation of 3 LED illuminations are to be visually matched with a monochromatic illumination, and a visual observation part. The three narrow band LEDs used have dominant wavelengths of 640 nm (red), 522 nm (green) and 458 nm (blue) respectively and their intensities can be controlled independently. After the calibration of wavelength and luminance of LED sources with a spectrophotometer, a series of visual color matching experiments have been carried out by 5 observers. The results are compared with those from CIE 1931 RGB color system, and have been used to compute an average locus for the spectral colors in the color triangle, with white at the center. It has been shown that the use of LED is feasible and has the advantages of easy control, good stability and low cost.

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

    Science.gov (United States)

    Baroudi, Kusai; Hassan, Nadia Aly

    2014-01-01

    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. PMID:25298598

  7. Chemical reaction dynamics using the Advanced Light Source

    International Nuclear Information System (INIS)

    Yang, X.; Blank, D.A.; Heimann, P.A.; Lee, Y.T.; Suits, A.G.; Lin, J.; Wodtke, A.M.

    1995-01-01

    The recently commissioned Advanced Light Source (ALS) at Berkeley provides a high brightness, tunable VUV light source for chemical dynamics studies. A dedicated chemical dynamics beamline has been built at the ALS for studies of fundamental chemical processes. High flux (10(sup 16) photon/s with 2% bandwidth) VUV synchrotron radiation from 5 to 30 eV can be obtained from the beamline, whose source is the U8/10 undulator. Three endstations will be in operation for studies ranging from crossed beam reaction dynamics and photodissociation to high resolution photoionization dynamics and spectroscopy. A rotatable source crossed molecular beam apparatus (endstation one) has been established for unimolecular and bimolecular reactive scattering studies. Photodissociation of methylamine and ozone were carried out using VUV synchrotron radiation as the ionization detection technique at this endstation. Results show the advantages of the new endstation using VUV ionization as the detection scheme over similar machines using electron bombardment as the ionization source

  8. Chemical reaction dynamics using the Advanced Light Source

    International Nuclear Information System (INIS)

    Yang, X.; Blank, D.A.; Heimann, P.A.; Lee, Y.T.; Suits, A.G.; Lin, J.; Wodtke, A.M.

    1995-09-01

    The recently commissioned Advanced Light Source (ALS) at Berkeley provides a high brightness, tunable VUV light source for chemical dynamics studies. A dedicated chemical dynamics beamline has been built at the ALS for studies of fundamental chemical processes. High flux (10 16 photon/s with 2% bandwidth) VUV synchrotron radiation from 5 to 30 eV can be obtained from the beamline, whose source is the U8/10 undulator. Three endstations will be in operation for studies ranging from crossed beam reaction dynamics and photodissociation to high resolution photoionization dynamics and spectroscopy. A rotatable source crossed molecular beam apparatus (endstation one) has been established for unimolecular and bimolecular reactive scattering studies. Photodissociation of methylamine and ozone were carried out using VUV synchrotron radiation as the ionization detection technique at this endstation. Results show the advantages of the new endstation using VUV ionization as the detection scheme over similar machines using electron bombardment as the ionization source

  9. Survey and alignment for the Swiss Light Source

    International Nuclear Information System (INIS)

    Wei, F.Q.; Dreyer, K.; Fehlmann, U.; Pochon, J.L.; Wrulich, A.

    1999-01-01

    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)

  10. The Advanced Light Source (ALS) Radiation Safety System

    International Nuclear Information System (INIS)

    Ritchie, A.; Oldfather, D.; Lindner, A.

    1993-05-01

    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. 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

  11. Tunable white light source for medical applications

    Science.gov (United States)

    Blaszczak, Urszula J.; Gryko, Lukasz; Zajac, Andrzej

    2017-08-01

    Development of light-emitting diodes has brought new possibilities in many applications, especially in terms of flexible adjustment of light spectra. This feature is very useful in construction of many devices, for example for medical diagnosis and treatment. It was proved, that in some cases LEDs can easily replace lasers during therapy of cancer without reduction of efficiency of this process. On the other hand during diagnosis process LED-based constructions can provide unique ability to adjust the color temperature of the output light while maintaining high color rendering. It allows for optimum surface contrast and enhanced tissue differentiation at the operator site. In the paper we describe the construction of the tunable LED-based source designed for application in endoscopy. It was optimized from the point of view of the color rendition for 5 different correlated color temperatures (illuminant A, D55, D65, 3500K and 4500K) with the restriction of very high (>90) values of general and specific color rendering indexes (according to Ra method). The source is composed of 13 light-emitting diodes from visible region mounted on the common radiator and controlled by dedicated system. Spectra of the components are mixed and the spectra of output light is analyzed. On the basis of obtained spectra colorimetric parameters are calculated and compared with the results of theoretical analysis.

  12. Improving the Efficiency of Solid State Light Sources

    International Nuclear Information System (INIS)

    Joanna McKittrick

    2003-01-01

    This proposal addresses the national need to develop a high efficiency light source for general illumination applications. The goal is to perform research that would lead to the fabrication of a unique solid state, white-emitting light source. This source is based on an InGaN/GaN UV-emitting chip that activates a luminescent material (phosphor) to produce white light. White-light LEDs are commercially available which use UV from a GaN chip to excite a phosphor suspended in epoxy around the chip. Currently, these devices are relatively inefficient. This research will target one technical barrier that presently limits the efficiency of GaN based devices. Improvements in efficiencies will be achieved by improving the internal conversion efficiency of the LED die, by improving the coupling between the die and phosphor(s) to reduce losses at the surfaces, and by selecting phosphors to maximize the emissions from the LEDs in conversion to white light. The UCSD research team proposes for this project to develop new phosphors that have high quantum efficiencies that can be activated by the UV-blue (360-410 nm) light emitted by the GaN device. The main goal for the UCSD team was to develop new phosphor materials with a very specific property: phosphors that could be excited at long UV-wavelengths (λ=350-410 nm). The photoluminescence of these new phosphors must be activated with photons emitted from GaN based dies. The GaN diodes can be designed to emit UV-light in the same range (λ=350-410 nm). A second objective, which is also very important, is to search for alternate methods to fabricate these phosphors with special emphasis in saving energy and time and reduce pollution

  13. Rapid Automatic Lighting Control of a Mixed Light Source for Image Acquisition using Derivative Optimum Search Methods

    Directory of Open Access Journals (Sweden)

    Kim HyungTae

    2015-01-01

    Full Text Available Automatic lighting (auto-lighting is a function that maximizes the image quality of a vision inspection system by adjusting the light intensity and color.In most inspection systems, a single color light source is used, and an equal step search is employed to determine the maximum image quality. However, when a mixed light source is used, the number of iterations becomes large, and therefore, a rapid search method must be applied to reduce their number. Derivative optimum search methods follow the tangential direction of a function and are usually faster than other methods. In this study, multi-dimensional forms of derivative optimum search methods are applied to obtain the maximum image quality considering a mixed-light source. The auto-lighting algorithms were derived from the steepest descent and conjugate gradient methods, which have N-size inputs of driving voltage and one output of image quality. Experiments in which the proposed algorithm was applied to semiconductor patterns showed that a reduced number of iterations is required to determine the locally maximized image quality.

  14. Broadband light source for fiber-optic measurement system in spaceborne applications

    Science.gov (United States)

    Rößner, Max R.; Müller, Mathias S.; Buck, Thorbjörn C.; Koch, Alexander W.

    2012-01-01

    Measuring temperatures, mechanical loads and derived quantities precisely and reliably play an important role in spaceflight. With spacecraft becoming increasingly complex, upscaling of present telemetry techniques can become cumbersome. Additionally, there are entirely new sensory requirements, resulting from emerging technologies such as smart structures, active vibration damping and composite material health monitoring. It has been demonstrated in preceding studies that these measurements can be advantageously and efficiently carried out by means of fiber-optic systems. The most prominent fiber-optic strain and temperature sensor is the fiber Bragg grating. Typically, multiple fiber Bragg gratings are used to translate entire temperature and strain fields into an optical wavelength information. For the interrogation of these sensors, a broadband or scanning light source is required. Additional requirements with respect to the light source are high intensity and unpolarized illumination of the gratings. These constraints can be met by a light source that is based on amplified spontaneous emission in a rare-earth-doped fiber. In the presented work, a compact light source, adapted for measurement applications and targeted towards space applications, has been developed. The design of this light source is presented, as well as its implementation. The light source has been designed and tested for selected core aspects of space robustness and the results of these tests are summarized.

  15. Misalignment with the external light environment drives metabolic and cardiac dysfunction.

    Science.gov (United States)

    West, Alexander C; Smith, Laura; Ray, David W; Loudon, Andrew S I; Brown, Timothy M; Bechtold, David A

    2017-09-12

    Most organisms use internal biological clocks to match behavioural and physiological processes to specific phases of the day-night cycle. Central to this is the synchronisation of internal processes across multiple organ systems. Environmental desynchrony (e.g. shift work) profoundly impacts human health, increasing cardiovascular disease and diabetes risk, yet the underlying mechanisms remain unclear. Here, we characterise the impact of desynchrony between the internal clock and the external light-dark (LD) cycle on mammalian physiology. We reveal that even under stable LD environments, phase misalignment has a profound effect, with decreased metabolic efficiency and disrupted cardiac function including prolonged QT interval duration. Importantly, physiological dysfunction is not driven by disrupted core clock function, nor by an internal desynchrony between organs, but rather the altered phase relationship between the internal clockwork and the external environment. We suggest phase misalignment as a major driver of pathologies associated with shift work, chronotype and social jetlag.The misalignment between internal circadian rhythm and the day-night cycle can be caused by genetic, behavioural and environmental factors, and may have a profound impact on human physiology. Here West et al. show that desynchrony between the internal clock and the external environment alter metabolic parameters and cardiac function in mice.

  16. 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.

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

    Science.gov (United States)

    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.

  18. 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)

  19. The interaction between internal R&D and different types of external knowledge sourcing: an empirical study of Chinese innovative firms

    NARCIS (Netherlands)

    Chen, Y.; Vanhaverbeke, W.; Du, J.

    2016-01-01

    This paper investigates to what extent internal R&D efforts and different types of external knowledge sources jointly affect innovation performance of firms in emerging economies. Based on a survey about external knowledge sourcing activities of Chinese innovative firms, we categorize external

  20. Ultraviolet light and heat source selection in captive spiny-tailed iguanas (Oplurus cuvieri)

    International Nuclear Information System (INIS)

    Dickinson, H.C.; Fa, J.E.

    1997-01-01

    Three experimental manipulations were conducted to assess the influence of heat source selection and active thermoregulation on ultraviolet (UV) light exposure in captive spiny-tailed iguanas (Oplurus cuvieri) at the Jersey Wildlife Preservation Trust. Four replicates per manipulation were conducted on six individual lizards. All animals were tested in a separate enclosure to which they were acclimated before observations. Data on choice of thermal sources were collected during the first 2 hr of light, when lizards were actively thermoregulating. Animals were allowed to choose between incandescent light, UV light and a non-light heat source (thermotube) in different combinations. Recorded temperatures close to the incandescent light (37°C) were always significantly higher than at the thermotube (33°C) and at the UV light (29°C). Manipulation 1 offered the animals a choice of an UV light and an incandescent light as thermal sources. Manipulation 2 presented animals with the thermal choices in Manipulation 1, but substrates under each source in Manipulation 1 were switched. In Manipulation 3, animals could choose between an incandescent light and the thermotube. All studied lizards were significantly more attracted to the incandescent light than to the UV light or thermotube. Incandescent light elicited a significantly higher proportion of basking behaviors in all individuals than the other sources. A high proportion of time basking was also spent in front of the thermotube but fewer individuals and less time were spent basking under the UV light. Heat source selection was generally found to be independent of substrate. Management applications of this preference are suggested for juvenile diurnal heliothermic iguanids. (author)

  1. Centralized light-source optical access network based on polarization multiplexing.

    Science.gov (United States)

    Grassi, Fulvio; Mora, José; Ortega, Beatriz; Capmany, José

    2010-03-01

    This paper presents and demonstrates a centralized light source optical access network based on optical polarization multiplexing technique. By using two optical sources emitting light orthogonally polarized in the Central Node for downstream and upstream operations, the Remote Node is kept source-free. EVM values below telecommunication standard requirements have been measured experimentally when bidirectional digital signals have been transmitted over 10 km of SMF employing subcarrier multiplexing technique in the electrical domain.

  2. Radiation effects on light sources and detectors

    International Nuclear Information System (INIS)

    Barnes, C.E.

    1985-01-01

    The rapidly expanding field of optoelectronics includes a wide variety of both military and non-military applications in which the systems must meet radiation exposure requirements. Herein, we review the work on radiation effects on sources and detectors for such optoelectronic systems. For sources the principal problem is permanent damage-induced light output degradation, while for detectors it is ionizing radiation-induced photocurrents

  3. Optical laser systems at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Minitti, Michael P.; Robinson, Joseph S.; Coffee, Ryan N.; Edstrom, Steve; Gilevich, Sasha; Glownia, James M.; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C.; Miahnahri, Alan; Milathianaki, Despina; Polzin, Wayne; Ratner, Daniel; Tavella, Franz; Vetter, Sharon; Welch, Marc; White, William E.; Fry, Alan R., E-mail: alanfry@slac.stanford.edu [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2015-04-22

    This manuscript serves as a reference to describe the optical laser sources and capabilities at the Linac Coherent Light Source. Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump–probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump–probe experiments to be performed at LCLS.

  4. The JLab high power ERL light source

    International Nuclear Information System (INIS)

    Neil, G.R.; Behre, C.; Benson, S.V.

    2006-01-01

    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 160MeV electron beam and an average current of 10mA in 75MHz 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 ∼ half cycle pulse whose average brightness is >5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20W of average power extracted [Carr, et al., Nature 420 (2002) 153]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100fs pulses with >200W of average power. The FELs also provide record-breaking laser power [Neil, et al., Phys. Rev. Lett. 84 (2000) 662]: up to 10kW of average power in the IR from 1 to 14μm in 400fs pulses at up to 74.85MHz repetition rates and soon will produce similar pulses of 300-1000nm light at up to 3kW 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 10ms 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

  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. 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.

  7. Advanced Light Source: Activity report 1993

    International Nuclear Information System (INIS)

    1994-11-01

    The Advanced Light Source (ALS) produces the world's brightest light in the ultraviolet and soft x-ray regions of the spectrum. The first low-energy third-generation synchrotron source in the world, the ALS provides unprecedented opportunities for research in science and technology not possible anywhere else. This year marked the beginning of operations and the start of the user research program at the ALS, which has already produced numerous high quality results. A national user facility located at Lawrence Berkeley Laboratory of the University of California, the ALS is available to researchers from academia, industry, and government laboratories. This report contains the following: (1) director's message; (2) operations overview; (3) user program; (4) users' executive committee; (5) industrial outreach; (6) accelerator operations; (7) beamline control system; (8) insertion devices; (9) experimental systems; (10) beamline engineering; (11) first results from user beamlines; (12) beamlines for 1994--1995; (13) special events; (14) publications; (15) advisory panels; and (16) ALS staff

  8. 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)

  9. Laser-produced plasma-extreme ultraviolet light source for next generation lithography

    International Nuclear Information System (INIS)

    Nishihara, Katsunobu; Nishimura, Hiroaki; Gamada, Kouhei; Murakami, Masakatsu; Mochizuki, Takayasu; Sasaki, Akira; Sunahara, Atsushi

    2005-01-01

    Extreme ultraviolet (EUV) lithography is the most promising candidate for the next generation lithography for the 45 nm technology node and below. EUV light sources under consideration use 13.5 nm radiations from multicharged xenon, tin and lithium ions, because Mo/Si multiplayer mirrors have high reflectivity at this wavelength. A review of laser-produced plasma (LPP) EUV light sources is presented with a focus on theoretical and experimental studies under the auspices of the Leading Project promoted by MEXT. We discuss three theoretical topics: atomic processes in the LPP-EUV light source, conversion efficiency from laser light to EUV light at 13.5 nm wave-length with 2% bound width, and fast ion spectra. The properties of EUV emission from tin and xenon plasmas are also shown based on experimental results. (author)

  10. Paul Scherrer Institute Scientific Report 1998. Volume VII: Swiss Light Source

    International Nuclear Information System (INIS)

    Weyer, Heinz Josef; Bugmann, Marlen; Neuhaus, Sibylle

    1999-01-01

    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

  11. Use of gaseous tritium light sources (Beta lights) with respect to nocturnal illumination

    International Nuclear Information System (INIS)

    Solomon, D.E.

    1988-01-01

    A number/letter plate for use in, for example darkened buildings has spaced apart gaseous tritium light sources (beta lights) arranged centrally along the indicia on a reflective background sealed in clear translucent plastics. Uses include house numbers, name plates, telephone numbers, notices, product advertisements, vehicle registration plates and names or trade marks on products. (author)

  12. Environmental Science Program at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Nico, Peter; A; Anastasio, Cort; Dodge, Cleveland; Fendorf, Scott; Francis, A.J.; Hubbard, Susan; Shuh, David; Tomutsa, Liviu; Tufano, Kate; Tyliszczak, Tolek; Werner, Michelle; Williams, Ken

    2006-04-05

    The Advanced Light Source (ALS) has a variety of capabilities that are applicable to very different types of environmental systems. Shown are the basic descriptions of four of the approximately 35 beam lines at the ALS. The complimentary capabilities of these four beam lines allow for investigations that range from a spatial scale of a few nanometers to several millimeters. The Environmental Science Program at the Advanced Light Source seeks to promote and assist environmental research, particularly on the four beam lines described in this report. Several short examples of the types of research conducted on these beam lines are also described.

  13. 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.

  14. On the addition of heat to solar pond from external sources

    NARCIS (Netherlands)

    Ganguly, S.; Jain, Ravi; Date, Abhijit; Akbarzadeh, Aliakbar

    2017-01-01

    This brief note addresses the method of adding heat to a solar pond from an external source which is used to enhance the performance of a solar pond. Heat energy collected by Evacuated Tube Solar Collectors (ETSC) is transferred by circulating fluid from the Lower Convective Zone (LCZ) of a solar

  15. Permanent magnet based dipole magnets for next generation light sources

    Directory of Open Access Journals (Sweden)

    Takahiro Watanabe

    2017-07-01

    Full Text Available We have developed permanent magnet based dipole magnets for the next generation light sources. Permanent magnets are advantageous over electromagnets in that they consume less power, are physically more compact, and there is a less risk of power supply failure. However, experience with electromagnets and permanent magnets in the field of accelerators shows that there are still challenges to replacing main magnets of accelerators for light sources with permanent magnets. These include the adjustability of the magnetic field, the temperature dependence of permanent magnets, and the issue of demagnetization. In this paper, we present a design for magnets for future light sources, supported by experimental and numerical results.

  16. Special Issue on advanced and emerging light sources

    NARCIS (Netherlands)

    Haverlag, M.; Kroesen, G.M.W.; Ferguson, I.

    2011-01-01

    EDITORIAL 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

  17. Systematical and statistical errors in using reference light sources to calibrate TLD readers

    International Nuclear Information System (INIS)

    Burgkhardt, B.; Piesch, E.

    1981-01-01

    Three light sources, namely an NaI(Tl) scintillator + Ra, an NaI(Tl) scintillator + 14 C and a plastic scintillator + 14 C, were used during a period of 24 months for a daily check of two TLD readers: the Harshaw 2000 A + B and the Toledo 651. On the basis of light source measurements long-term changes and day-to-day fluctuations of the reader response were investigated. Systematical changes of the Toledo reader response of up to 6% during a working week are explained by nitrogen effects in the plastic scintillator light source. It was found that the temperature coefficient of the light source intensity was -0.05%/ 0 C for the plastic scintillator and -0.3%/ 0 C for the NaI(Tl) scintillator. The 210 Pb content in the Ra activated NaI(Tl) scintillator caused a time-dependent decrease in light source intensity of 3%/yr for the light source in the Harshaw reader. The internal light sources revealed a relative standard deviation of 0.5% for the Toledo reader and the Harshaw reader after respective reading times of 0.45 and 100 sec. (author)

  18. Tunable high-power narrow-spectrum external-cavity diode laser at 675 nm as a pump source for UV generation

    DEFF Research Database (Denmark)

    Chi, Mingjun; Jensen, Ole Bjarlin; Erbert, Gotz

    2011-01-01

    High-power narrow-spectrum diode laser systems based on tapered gain media in external cavity are demonstrated at 675 nm. Two 2-mm-long amplifiers are used, one with a 500-µm-long ridge-waveguide section (device A), the other with a 750-µm-long ridge-waveguide section (device B). The laser system...... of 1.0 W. The laser system B based on device B is tunable from 666 to 685 nm. As high as 1.05 W output power is obtained around 675.67 nm. The emission spectral bandwidth is less than 0.07 nm throughout the tuning range, and the beam quality factor M2 is 1.13 at an output power of 0.93 W. The laser...... system B is used as a pump source for the generation of 337.6 nm UV light by single-pass frequency doubling in a BIBO crystal. An output power of 109 µW UV light, corresponding to a conversion efficiency of 0.026%W-1 is attained....

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

    Science.gov (United States)

    Grandjean, N.

    2010-09-01

    comprehensive review of the different localization mechanisms and their implication for internal quantum efficiency (IQE) is proposed by Oliver and co-workers from Cambridge University. When discussing IQE in InGaN-based LEDs, the efficiency droop at high-current injection always emerges, which is a major concern for the future of SSL technology. Here, a collaborative work between Samsung and the Gwangju Institute of Science and Technology (Korea) proves that a specific design of the active region can limit this detrimental effect. Once the issue of the IQE is solved, one still has to let the photons out of the chip. Matioli and Weisbuch from the University of California at Santa Barbara introduce the use of photonic crystals (PhCs) to improve light extraction efficiency. They describe different approaches to overcoming the main limitation of LEDs when implementing surface PhCs. The technology of SSL, and in particular of colour rendering, is tackled by Zukauskas et al who studied in detail different white light sources. They show that extreme colour-fidelity indices need to cover the entire spectrum, with a broad-band at 530-610 nm and a component beyond 610 nm. Then, the reliability of GaN-based LEDs is discussed in the paper of Meneghesso and co-workers. The authors consider the most important physical mechanisms that are (i) the degradation of the active layer of LEDs, (ii) the degradation of the package/phosphor system, (iii) the failure of GaN-based LEDs against electrostatic discharge. Finally, GaN LEDs on silicon developed in the group of Egawa at the Nagoya Institute of Technology are presented. This technology could allow a significant decrease in the fabrication cost of white LEDs.

  20. AutoLens: Automated Modeling of a Strong Lens's Light, Mass and Source

    Science.gov (United States)

    Nightingale, J. W.; Dye, S.; Massey, Richard J.

    2018-05-01

    This work presents AutoLens, the first entirely automated modeling suite for the analysis of galaxy-scale strong gravitational lenses. AutoLens simultaneously models the lens galaxy's light and mass whilst reconstructing the extended source galaxy on an adaptive pixel-grid. The method's approach to source-plane discretization is amorphous, adapting its clustering and regularization to the intrinsic properties of the lensed source. The lens's light is fitted using a superposition of Sersic functions, allowing AutoLens to cleanly deblend its light from the source. Single component mass models representing the lens's total mass density profile are demonstrated, which in conjunction with light modeling can detect central images using a centrally cored profile. Decomposed mass modeling is also shown, which can fully decouple a lens's light and dark matter and determine whether the two component are geometrically aligned. The complexity of the light and mass models are automatically chosen via Bayesian model comparison. These steps form AutoLens's automated analysis pipeline, such that all results in this work are generated without any user-intervention. This is rigorously tested on a large suite of simulated images, assessing its performance on a broad range of lens profiles, source morphologies and lensing geometries. The method's performance is excellent, with accurate light, mass and source profiles inferred for data sets representative of both existing Hubble imaging and future Euclid wide-field observations.

  1. 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.

  2. A novel method for detecting light source for digital images forensic

    Science.gov (United States)

    Roy, A. K.; Mitra, S. K.; Agrawal, R.

    2011-06-01

    Manipulation in image has been in practice since centuries. These manipulated images are intended to alter facts — facts of ethics, morality, politics, sex, celebrity or chaos. Image forensic science is used to detect these manipulations in a digital image. There are several standard ways to analyze an image for manipulation. Each one has some limitation. Also very rarely any method tried to capitalize on the way image was taken by the camera. We propose a new method that is based on light and its shade as light and shade are the fundamental input resources that may carry all the information of the image. The proposed method measures the direction of light source and uses the light based technique for identification of any intentional partial manipulation in the said digital image. The method is tested for known manipulated images to correctly identify the light sources. The light source of an image is measured in terms of angle. The experimental results show the robustness of the methodology.

  3. 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.

  4. RESEARCH OF NIGHT LIGHT EFFECTS ON COLORIMETRIC CHARACTERISTICS OF IMAGE PERCEIVED BY THE PILOT IN AN AIRCRAFT COCKPIT

    Directory of Open Access Journals (Sweden)

    I. O. Zharinov

    2015-09-01

    Full Text Available Subject of Research. The influence of radiation spectra from the source of artificial night light on colorimetric characteristics of image perceived by the pilot in the aircraft cockpit has been studied. The image is displayed on the LCD screen of multifunctional color indication equipment unit. Night illumination of the cockpit is performed with the use of artificial lamps of red, green, blue and, rarely, white light. Method. Any given color to be displayed on the screen is perceived by an observer differently with presence and absence of external illumination. When external light of white color is used, perceived color depends upon color temperature of the light source; if illumination source has any arbitrary spectral characteristics, then perceivable color depends upon whole spectral content of the used source. The color, perceived by an observer, is formed as the mixture of the color displayed on the screen (image element color with the color presented by diffuse reflection of external illumination source from the surface of the screen. The brightness of both colors is added. Mathematical expressions, that define calculation rule for chromaticity coordinates of color perceived by an observer, are based on the Grassmann’s law of additive color mixing. Quantitative analysis of the effect, caused by radiation spectra from an external source of artificial light on color gamut area, corresponding to image, perceived by an observer, has been performed through simulation in MathCad 15.0. Main Results. It was shown, that the color palette of on-board indication equipment, obtained on automated working place for any preset source of external illumination of fluorescent spectrum, corresponding to white light, is not usable correctly in the aircraft night flight mode. An observer loses ability to perceive properly saturated primary colors of red and blue in the case of green-blue light source of external illumination; and the same issue occurs with

  5. Dosimetry services for internal and external radiation sources

    International Nuclear Information System (INIS)

    1988-01-01

    The Canadian Atomic Energy Control Board (AECB) sets radiation dose limits for the operation of nuclear facilities and the possession of prescribed substances within Canada. To administer these regulations the AECB must be satisfied that the dosimetry services used by a licensee meet adequate standards. Licensees are required to use the Occupational Dosimetry Service operated by the Bureau of Radiation and Medical Devices, Department of National Health and Welfare (BRMD) to determine doses from external sources of radiation, except where a detailed rationale is given for using another service. No national dosimetry service exists for internal sources of radiation. Licensees who operate or use a dosimetry service other than the BRMD must provide the AECB with evidence of the competence of the staff and adequacy of the equipment, techniques and procedures; provide the AECB with evidence that a quality assurance program has been implemented; and send individual dose or exposure data to the National Dose Registry. (L.L.)

  6. Light Source Estimation with Analytical Path-tracing

    OpenAIRE

    Kasper, Mike; Keivan, Nima; Sibley, Gabe; Heckman, Christoffer

    2017-01-01

    We present a novel algorithm for light source estimation in scenes reconstructed with a RGB-D camera based on an analytically-derived formulation of path-tracing. Our algorithm traces the reconstructed scene with a custom path-tracer and computes the analytical derivatives of the light transport equation from principles in optics. These derivatives are then used to perform gradient descent, minimizing the photometric error between one or more captured reference images and renders of our curre...

  7. Salient features in the preparation of gaseous tritium filled luminous light sources

    International Nuclear Information System (INIS)

    Mathew, K.M.; Ravi, S.; Subramanian, T.K.; Ananthakrishnan, M.

    2003-01-01

    Beta radiation emanating from gaseous tritium in close proximity with copper activated zinc sulphide phosphor provides self sustained light sources and these sources are used for nocturnal illumination of liquid crystal display in digital watches and clocks, product advertisements, exit signs etc. We report herein the preparation of low specific radioactivity gaseous tritium (29.5 Ci/m mole; 1.09 TBq/m mole) filled light sources and its effect on light output. (author)

  8. IMPACT OF EXTERNAL REIMBURSABLE FINANING ON VAT RECEIPTS IN THE STATE BUDGET OF THE REPUBLIC OF MOLDOVA

    Directory of Open Access Journals (Sweden)

    Marcel OLARI

    2017-04-01

    Full Text Available Under the current conditions, where rapid economic growth is an important prerequisite for improving the well-being of the population and reducing poverty, the state, being an important player on the economic arena of the Republic of Moldova, attracts external sources of reimbursable financing to support the budget and to carry out investment projects. Taking into account that these external sources increase the Central Government debt, generate the payment of certain interest, commissions, directly affect the expenditures of the state budget, I intended to investigate the impact of these reimbursable external sources on the one category of revenues of the state budget of the Republic of Moldova, (Value Added Tax receipts, in the light of the service and merchandise deliveries according to the transactions emerged from the contracted external reimbursable financing sources.

  9. High gradient accelerators for linear light sources

    International Nuclear Information System (INIS)

    Barletta, W.A.

    1988-01-01

    Ultra-high gradient radio frequency linacs powered by relativistic klystrons appear to be able to provide compact sources of radiation at XUV and soft x-ray wavelengths with a duration of 1 picosecond or less. This paper provides a tutorial review of the physics applicable to scaling the present experience of the accelerator community to the regime applicable to compact linear light sources. 22 refs., 11 figs., 21 tabs

  10. The Advanced Light Source (ALS) Radiation Safety System

    International Nuclear Information System (INIS)

    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

  11. Dynamic Aperture Measurements at the Advanced Light Source

    International Nuclear Information System (INIS)

    Decking, W.; Robin, D.

    1999-01-01

    A large dynamic aperture for a storage ring is of importance for long lifetimes and a high injection efficiency. Measurements of the dynamic aperture of the third generation synchrotron light source Advanced Light Source (ALS) using beam excitation with kicker magnets are presented. The experiments were done for various accelerator conditions, allowing us to investigate the influence of different working points, chromaticities, insertion devices, etc.. The results are compared both with tracking calculations and a simple model for the dynamic aperture yielding good agreements. This gives us confidence in the predictability of the nonlinear accelerator model. This is especially important for future ALS upgrades as well as new storage ring designs

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    This paper offers an overview of area detectors developed for use at the Linac Coherent Light Source (LCLS) with particular emphasis on their impact on science. The experimental needs leading to the development of second-generation cameras for LCLS are discussed and the new detector prototypes are presented. 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

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

    Science.gov (United States)

    Karaman, Emel; Gönülol, Nihan

    2014-01-01

    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.

  14. New lasers and light sources - old and new risks?

    DEFF Research Database (Denmark)

    Paasch, Uwe; Schwandt, Antje; Seeber, Nikolaus

    2017-01-01

    Recent developments (new wavelengths, treatment concepts, and combinations) in the field of lasers, intense pulsed light (IPL), LED, as well as new energy and light sources have opened up new therapeutic options that extend beyond mere aesthetic indications. Thus, while fractional lasers used...

  15. Swiss synchrotron light source at the Paul Scherrer Institute at Villigen

    International Nuclear Information System (INIS)

    1996-02-01

    The brochure describes the Swiss project for a synchrotron light source to be built at the Paul Scherrer Institute at Villigen. According to the project the synchrotron light source shall be realized up to the year 2001 at costs of 165 Million Swiss Francs. figs., tabs

  16. Neoclassical parallel flow calculation in the presence of external parallel momentum sources in Heliotron J

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, K.; Nakamura, Y. [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Nishimura, S. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan); Lee, H. Y. [Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Kobayashi, S.; Mizuuchi, T.; Nagasaki, K.; Okada, H.; Minami, T.; Kado, S.; Yamamoto, S.; Ohshima, S.; Konoshima, S.; Sano, F. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

    2016-03-15

    A moment approach to calculate neoclassical transport in non-axisymmetric torus plasmas composed of multiple ion species is extended to include the external parallel momentum sources due to unbalanced tangential neutral beam injections (NBIs). The momentum sources that are included in the parallel momentum balance are calculated from the collision operators of background particles with fast ions. This method is applied for the clarification of the physical mechanism of the neoclassical parallel ion flows and the multi-ion species effect on them in Heliotron J NBI plasmas. It is found that parallel ion flow can be determined by the balance between the parallel viscosity and the external momentum source in the region where the external source is much larger than the thermodynamic force driven source in the collisional plasmas. This is because the friction between C{sup 6+} and D{sup +} prevents a large difference between C{sup 6+} and D{sup +} flow velocities in such plasmas. The C{sup 6+} flow velocities, which are measured by the charge exchange recombination spectroscopy system, are numerically evaluated with this method. It is shown that the experimentally measured C{sup 6+} impurity flow velocities do not contradict clearly with the neoclassical estimations, and the dependence of parallel flow velocities on the magnetic field ripples is consistent in both results.

  17. 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.

  18. New lasers and light sources - old and new risks?

    DEFF Research Database (Denmark)

    Paasch, Uwe; Schwandt, Antje; Seeber, Nikolaus

    2017-01-01

    Recent developments (new wavelengths, treatment concepts, and combinations) in the field of lasers, intense pulsed light (IPL), LED, as well as new energy and light sources have opened up new therapeutic options that extend beyond mere aesthetic indications. Thus, while fractional lasers used to ...

  19. 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.

  20. 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.

  1. Data format standard for sharing light source measurements

    Science.gov (United States)

    Gregory, G. Groot; Ashdown, Ian; Brandenburg, Willi; Chabaud, Dominique; Dross, Oliver; Gangadhara, Sanjay; Garcia, Kevin; Gauvin, Michael; Hansen, Dirk; Haraguchi, Kei; Hasna, Günther; Jiao, Jianzhong; Kelley, Ryan; Koshel, John; Muschaweck, Julius

    2013-09-01

    Optical design requires accurate characterization of light sources for computer aided design (CAD) software. Various methods have been used to model sources, from accurate physical models to measurement of light output. It has become common practice for designers to include measured source data for design simulations. Typically, a measured source will contain rays which sample the output distribution of the source. The ray data must then be exported to various formats suitable for import into optical analysis or design software. Source manufacturers are also making measurements of their products and supplying CAD models along with ray data sets for designers. The increasing availability of data has been beneficial to the design community but has caused a large expansion in storage needs for the source manufacturers since each software program uses a unique format to describe the source distribution. In 2012, the Illuminating Engineering Society (IES) formed a working group to understand the data requirements for ray data and recommend a standard file format. The working group included representatives from software companies supplying the analysis and design tools, source measurement companies providing metrology, source manufacturers creating the data and users from the design community. Within one year the working group proposed a file format which was recently approved by the IES for publication as TM-25. This paper will discuss the process used to define the proposed format, highlight some of the significant decisions leading to the format and list the data to be included in the first version of the standard.

  2. Source attribution of light-absorbing impurities in seasonal snow across northern China

    Science.gov (United States)

    Zhang, R.; Hegg, D. A.; Huang, J.; Fu, Q.

    2013-01-01

    Seasonal snow samples obtained at 46 sites in 6 provinces of China in January and February 2010 were analyzed for a suite of chemical species and these data are combined with previously determined concentrations of light-absorbing impurities (LAI), including all particles that absorb light in the 650-700 nm wavelength interval. The LAI, together with 14 other analytes, are used as input to a positive matrix factorization (PMF) receptor model to explore the sources of the LAI in the snow. The PMF analysis for the LAI sources is augmented with backward trajectory cluster analysis and the geographic locations of major source areas for the three source types. The two analyses are consistent and indicate that three factors/sources were responsible for the measured snow light absorption: a soil dust source, an industrial pollution source, and a biomass and biofuels burning source. Soil dust was the main source of the LAI, accounting for ~ 53% of the LAI on average.

  3. Optimization of light source parameters in the photodynamic therapy of heterogeneous prostate

    International Nuclear Information System (INIS)

    Li Jun; Altschuler, Martin D; Hahn, Stephen M; Zhu, Timothy C

    2008-01-01

    The three-dimensional (3D) heterogeneous distributions of optical properties in a patient prostate can now be measured in vivo. Such data can be used to obtain a more accurate light-fluence kernel. (For specified sources and points, the kernel gives the fluence delivered to a point by a source of unit strength.) In turn, the kernel can be used to solve the inverse problem that determines the source strengths needed to deliver a prescribed photodynamic therapy (PDT) dose (or light-fluence) distribution within the prostate (assuming uniform drug concentration). We have developed and tested computational procedures to use the new heterogeneous data to optimize delivered light-fluence. New problems arise, however, in quickly obtaining an accurate kernel following the insertion of interstitial light sources and data acquisition. (1) The light-fluence kernel must be calculated in 3D and separately for each light source, which increases kernel size. (2) An accurate kernel for light scattering in a heterogeneous medium requires ray tracing and volume partitioning, thus significant calculation time. To address these problems, two different kernels were examined and compared for speed of creation and accuracy of dose. Kernels derived more quickly involve simpler algorithms. Our goal is to achieve optimal dose planning with patient-specific heterogeneous optical data applied through accurate kernels, all within clinical times. The optimization process is restricted to accepting the given (interstitially inserted) sources, and determining the best source strengths with which to obtain a prescribed dose. The Cimmino feasibility algorithm is used for this purpose. The dose distribution and source weights obtained for each kernel are analyzed. In clinical use, optimization will also be performed prior to source insertion to obtain initial source positions, source lengths and source weights, but with the assumption of homogeneous optical properties. For this reason, we compare the

  4. A Stroboscopic Light Source for Experiments in Mechanics

    Science.gov (United States)

    Mayer, V. V.; Varaksina, E. I.

    2017-01-01

    We propose to attach a small stroboscopic light source to a moving object and connect the source to a pulse generator with the help of insulated thin flexible multi-cored wires. Students can assemble such a device independently in a school laboratory. The device can be used to obtain trajectories with time marks in students' research projects in…

  5. Measuring light spectrum as a main indicator of artificial sources quality

    Directory of Open Access Journals (Sweden)

    Piotr Dąbrowski

    2015-05-01

    Full Text Available Objective: To compare different artificial light sources in different places where plant breeding is conduced. Methods: Measurements were conducted outdoor, in room, in greenhouse, under four panels with light emitting diodes, in phytotron, in dark room with various light sources and inside Sanyo versatile environmental chamber. The measurements were made by using SpectraPen SP100 (PSI, Czech Republic device. Results: Our result showed that spectrum measured outdoor during sunny day had only one peak at the wavelength of 485 nm (ca. 60000 relative units. On cloudy day, the trend of light spectrum curve was similar, but with lower values. At room conditions, the curve was more flat than outdoor. Under greenhouse conditions, the curve was similar to that measured outdoor. A few additional peaks on the curve appeared by adding high pressure sodium lamp. There were changes of curve under LED panels. Conclusions: It must be underlined that the most similar spectrum curve to daylight light has incandescent bulb and this light source should be preferred as support of daylight in greenhouses and as main source in phytotrons. Using high pressure sodium lamp in greenhouses as support of daylight cause increase in the red/far-red ratio and occurrence of a new peak on spectrum curve. The new possibilities are creating by LED panels with red and blue diodes.

  6. Advanced Light Source Activity Report 1997/1998

    International Nuclear Information System (INIS)

    Greiner, Annette

    1999-01-01

    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

  7. 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.

  8. 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.

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

    International Nuclear Information System (INIS)

    Murphy, J.B.

    1996-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, J.B.

    1996-05-01

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

  11. Fundamental characteristics of a synthesized light source for optical coherence tomography.

    Science.gov (United States)

    Sato, Manabu; Wakaki, Ichiro; Watanabe, Yuuki; Tanno, Naohiro

    2005-05-01

    We describe the fundamental characteristics of a synthesized light source (SLS) consisting of two low-coherence light sources to enhance the spatial resolution for optical coherence tomography (OCT). The axial resolution of OCT is given by half the coherence length of the light source. We fabricated a SLS with a coherence length of 2.3 microm and a side-lobe intensity of 45% with an intensity ratio of LED1:LED2 = 1:0.5 by combining two light sources, LED1, with a central wavelength of 691 nm and a spectral bandwidth of 99 nm, and LED2, with a central wavelength of 882 nm and a spectral bandwidth of 76 nm. The coherence length of 2.3 microm was 56% of the shorter coherence length in the two LEDs, which indicates that the axial resolution is 1.2 microm. The lateral resolution was measured at less than 4.4 microm by use of the phase-shift method and with a test pattern as a sample. The measured rough surfaces of a coin are illustrated and discussed.

  12. Boron-Containing Red Light-Emitting Phosphors And Light Sources Incorporating The Same

    Science.gov (United States)

    Srivastava, Alok Mani; Comanzo, Holly Ann; Manivannan, Venkatesan

    2006-03-28

    A boron-containing phosphor comprises a material having a formula of AD1-xEuxB9O16, wherein A is an element selected from the group consisting of Ba, Sr, Ca, Mg, and combinations thereof; D is at least an element selected from the group consisting of rare-earth metals other than europium; and x is in the range from about 0.005 to about 0.5. The phosphor is used in a blend with other phosphors in a light source for generating visible light with a high color rendering index.

  13. Project planning workshop 6-GeV synchrotron light source: Volume 1

    International Nuclear Information System (INIS)

    1986-01-01

    A model 6 GeV synchrotron light source is described, and the costs, schedule, and manpower associated with producing such a synthrotron light source are summarized. A program consisting of a two-year pre-construction phase, a five-year construction phase, and a three-year post-construction phase and costing a total of $379.6 million is assumed

  14. 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.

  15. Modeling Noise Sources and Propagation in External Gear Pumps

    Directory of Open Access Journals (Sweden)

    Sangbeom Woo

    2017-07-01

    Full Text Available As a key component in power transfer, positive displacement machines often represent the major source of noise in hydraulic systems. Thus, investigation into the sources of noise and discovering strategies to reduce noise is a key part of improving the performance of current hydraulic systems, as well as applying fluid power systems to a wider range of applications. The present work aims at developing modeling techniques on the topic of noise generation caused by external gear pumps for high pressure applications, which can be useful and effective in investigating the interaction between noise sources and radiated noise and establishing the design guide for a quiet pump. In particular, this study classifies the internal noise sources into four types of effective load functions and, in the proposed model, these load functions are applied to the corresponding areas of the pump case in a realistic way. Vibration and sound radiation can then be predicted using a combined finite element and boundary element vibro-acoustic model. The radiated sound power and sound pressure for the different operating conditions are presented as the main outcomes of the acoustic model. The noise prediction was validated through comparison with the experimentally measured sound power levels.

  16. Cathode R and D for future light sources

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, D.H., E-mail: dowell@slac.stanford.ed [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Bazarov, I.; Dunham, B. [Cornell University, Cornell Laboratory for Accelerator-Based Sciences and Education (CLASSE) Wilson Laboratory, Cornell University, Ithaca, NY 14853 (United States); Harkay, K. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Il 60439 (United States); Hernandez-Garcia, C. [Thomas Jefferson Laboratory, 12000 Jefferson Ave, Free Electron Laser Suite 19 Newport News, VA 23606 (United States); Legg, R. [University of Wisconsin, SRC, 3731 Schneider Dr., Stoughton, WI 53589 (United States); Padmore, H. [Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720 (United States); Rao, T.; Smedley, J. [Brookhaven National Laboratory, 20 Technology Street, Bldg. 535B, Brookhaven National Laboratory Upton, NY 11973 (United States); Wan, W. [Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720 (United States)

    2010-10-21

    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.

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

    Science.gov (United States)

    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.

  18. Radio Frequency Plasma Discharge Lamps for Use as Stable Calibration Light Sources

    Science.gov (United States)

    McAndrew, Brendan; Cooper, John; Arecchi, Angelo; McKee, Greg; Durell, Christopher

    2012-01-01

    Stable high radiance in visible and near-ultraviolet wavelengths is desirable for radiometric calibration sources. In this work, newly available electrodeless radio-frequency (RF) driven plasma light sources were combined with research grade, low-noise power supplies and coupled to an integrating sphere to produce a uniform radiance source. The stock light sources consist of a 28 VDC power supply, RF driver, and a resonant RF cavity. The RF cavity includes a small bulb with a fill gas that is ionized by the electric field and emits light. This assembly is known as the emitter. The RF driver supplies a source of RF energy to the emitter. In commercial form, embedded electronics within the RF driver perform a continual optimization routine to maximize energy transfer to the emitter. This optimization routine continually varies the light output sinusoidally by approximately 2% over a several-second period. Modifying to eliminate this optimization eliminates the sinusoidal variation but allows the output to slowly drift over time. This drift can be minimized by allowing sufficient warm-up time to achieve thermal equilibrium. It was also found that supplying the RF driver with a low-noise source of DC electrical power improves the stability of the lamp output. Finally, coupling the light into an integrating sphere reduces the effect of spatial fluctuations, and decreases noise at the output port of the sphere.

  19. The Role of External Sources of Information in Children's Evaluative Food Categories

    Science.gov (United States)

    Nguyen, Simone P.

    2012-01-01

    Evaluative food categories are value-laden assessments, which reflect the healthfulness and palatability of foods (e.g. healthy/unhealthy, yummy/yucky). In a series of three studies, this research examines how 3- to 4-year-old children (N?=?147) form evaluative food categories based on input from external sources of information. The results…

  20. 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.

  1. Classification of radioactive self-luminous light sources - approved 1975. NBS Handbook 116

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The standard establishes the classification of certain radioactive self-luminous light sources according to radionuclide, type of source, activity, and performance requirements. The objectives are to establish minimum prototype testing requirements for radioactive self-luminous light sources, to promote uniformity of marking such sources, and to establish minimum physical performance for such sources. The standard is primarily directed toward assuring adequate containment of the radioactive material. Testing procedures and classification designations are specified for discoloration, temperature, thermal shock, reduced pressure, impact, vibration, and immersion. A range of test requirements is presented according to intended usage and source activity

  2. Study of Selecting on Light Source Used for Micro-algae Cultivation in Space

    Science.gov (United States)

    Ai, Weidang; Ai, Weidang; Guo, Shuang-Sheng; Gao, Feng; Tang, Yong-Kang; Qin, Li-Feng

    To select suitable light source for micro-algae cultivation in future space station, the selected Spirulina plastensis(No.7) were cultured under different lightening qualities, including six light sources that were made up of different combinations of red and blue light-emitting diode(LED). The growth, photosynthetic efficiency and nutrition quality of the Spirulina, were analyzed. From the experiments, the red light may promote the cumulation of biomass of the Spirulina, and the cumulating rate was the highest under all red light source, but the syntheses of protein, phycobiliprotein, β-carotene, VE and other nutrients needs a certain portion of blue light; yet, the complete blue light condition is not favorable to the growth of Spirulina, and may bring pollution by chlorella and other kinds of micro-algae. It is concluded that the LEDs can be used as the light resource of micro-algae cultivation. The normal growth and development of microalgae need two light sources of both red and blue LEDs. The comprehensive analyses of the various factors that affect the growth of Spirulina, such as nutrition quality and photosynthetic activities, etc., showed that the combination of 80% red and 20% blue LED is the optimum one among those tested combinations. Key word: light-emitting diode; micro-algae; controlled ecological life support system (CELSS); space cultivation

  3. 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...... the concentration of rhodamine 6G dye inside two integrated vertical resonators, since both the refractive index and the gain profile are influenced by the dye concentration. The effect on the refractive index and the gain profile of rhodamine 6G in ethanol is investigated and the continuous tuning of the laser...

  4. Survey, alignment, and beam stability at the Advanced Light Source

    International Nuclear Information System (INIS)

    Krebs, G.F.

    1997-10-01

    This paper describes survey and alignment at the Lawrence Berkeley Laboratories Advanced Light Source (ALS) accelerators from 1993 to 1997. The ALS is a third generation light source requiring magnet alignment to within 150 microns. To accomplish this, a network of monuments was established and maintained. Monthly elevation surveys show the movement of the floor over time. Inclinometers have recently been employed to give real time information about magnet, vacuum tank and magnet girder motion in the ALS storage ring

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

    OpenAIRE

    Beczkowski, Szymon

    2012-01-01

    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 ach...

  6. Temperature Characteristics of Monolithically Integrated Wavelength-Selectable Light Sources

    International Nuclear Information System (INIS)

    Han Liang-Shun; Zhu Hong-Liang; Zhang Can; Ma Li; Liang Song; Wang Wei

    2013-01-01

    The temperature characteristics of monolithically integrated wavelength-selectable light sources are experimentally investigated. The wavelength-selectable light sources consist of four distributed feedback (DFB) lasers, a multimode interferometer coupler, and a semiconductor optical amplifier. The oscillating wavelength of the DFB laser could be modulated by adjusting the device operating temperature. A wavelength range covering over 8.0nm is obtained with stable single-mode operation by selecting the appropriate laser and chip temperature. The thermal crosstalk caused by the lateral heat spreading between lasers operating simultaneously is evaluated by oscillating-wavelength shift. The thermal crosstalk approximately decreases exponentially as the increasing distance between lasers

  7. Recycled Thermal Energy from High Power Light Emitting Diode Light Source.

    Science.gov (United States)

    Ji, Jae-Hoon; Jo, GaeHun; Ha, Jae-Geun; Koo, Sang-Mo; Kamiko, Masao; Hong, JunHee; Koh, Jung-Hyuk

    2018-09-01

    In this research, the recycled electrical energy from wasted thermal energy in high power Light Emitting Diode (LED) system will be investigated. The luminous efficiency of lights has been improved in recent years by employing the high power LED system, therefore energy efficiency was improved compared with that of typical lighting sources. To increase energy efficiency of high power LED system further, wasted thermal energy should be re-considered. Therefore, wasted thermal energy was collected and re-used them as electrical energy. The increased electrical efficiency of high power LED devices was accomplished by considering the recycled heat energy, which is wasted thermal energy from the LED. In this work, increased electrical efficiency will be considered and investigated by employing the high power LED system, which has high thermal loss during the operating time. For this research, well designed thermoelement with heat radiation system was employed to enhance the collecting thermal energy from the LED system, and then convert it as recycled electrical energy.

  8. 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...

  9. The dislocation distribution function near a crack tip generated by external sources

    International Nuclear Information System (INIS)

    Lung, C.W.; Deng, K.M.

    1988-06-01

    The dislocation distribution function near a crack tip generated by external sources is calculated. It is similar to the shape of curves calculated for the crack tip emission case but the quantative difference is quite large. The image forces enlarges the negative dislocation zone but does not change the form of the curve. (author). 10 refs, 3 figs

  10. Prediction of the neutrons subcritical multiplication using the diffusion hybrid equation with external neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Costa da Silva, Adilson; Carvalho da Silva, Fernando [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, 21941-914, Rio de Janeiro (Brazil); Senra Martinez, Aquilino, E-mail: aquilino@lmp.ufrj.br [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, 21941-914, Rio de Janeiro (Brazil)

    2011-07-15

    Highlights: > We proposed a new neutron diffusion hybrid equation with external neutron source. > A coarse mesh finite difference method for the adjoint flux and reactivity calculation was developed. > 1/M curve to predict the criticality condition is used. - Abstract: We used the neutron diffusion hybrid equation, in cartesian geometry with external neutron sources to predict the subcritical multiplication of neutrons in a pressurized water reactor, using a 1/M curve to predict the criticality condition. A Coarse Mesh Finite Difference Method was developed for the adjoint flux calculation and to obtain the reactivity values of the reactor. The results obtained were compared with benchmark values in order to validate the methodology presented in this paper.

  11. Prediction of the neutrons subcritical multiplication using the diffusion hybrid equation with external neutron sources

    International Nuclear Information System (INIS)

    Costa da Silva, Adilson; Carvalho da Silva, Fernando; Senra Martinez, Aquilino

    2011-01-01

    Highlights: → We proposed a new neutron diffusion hybrid equation with external neutron source. → A coarse mesh finite difference method for the adjoint flux and reactivity calculation was developed. → 1/M curve to predict the criticality condition is used. - Abstract: We used the neutron diffusion hybrid equation, in cartesian geometry with external neutron sources to predict the subcritical multiplication of neutrons in a pressurized water reactor, using a 1/M curve to predict the criticality condition. A Coarse Mesh Finite Difference Method was developed for the adjoint flux calculation and to obtain the reactivity values of the reactor. The results obtained were compared with benchmark values in order to validate the methodology presented in this paper.

  12. 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.

  13. 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.

  14. The influence of external source intensity in accelerator/target/blanket system on conversion ratio and fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Kochurov, B.P. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)

    1995-10-01

    The analysis of neutron balance relation for a subcritical system with external source shows that a high ratio of neutron utilization (conversion ratio, breeding ratio) much exceeding similar values for nuclear reactors (both thermal or fast spectrum) is reachable in accelerator/target/blanket system with high external neutron source intensity. An accelerator/target/blanket systems with thermal power in blanket about 1850 Mwt and operating during 30 years have been investigated. Continual feed up by plutonium (fissile material) and Tc-99 (transmuted material) was assumed. Accelerator beam intensity differed 6.3 times (16 mA - Case 1, and 100 mA-Case 2). Conversion ratio (CR) was defined as the ratio of Tc-99 nuclei transmuted to the number of Pu nuclei consumed. High value of conversion ratio considerably exceeding 1 (CR=1.66) was obtained in the system with high source intensity as compared with low source system (CR=0.77). Net output of electric power of high source intensity system is about twice lower due to consumption of electric power for accelerator feed up. The loss of energy for Tc-99 transmutation is estimated as 40 Mev(el)/nuclei. Yet high conversion ratio (or breeding ratio) achievable in electronuclear installations with high intensity of external source can effectively be used to close fuel cycle (including incineration of wastes) or to develop growing nuclear power production system.

  15. Source attribution of insoluble light-absorbing particles in seasonal snow across northern China

    Science.gov (United States)

    Zhang, R.; Hegg, D. A.; Huang, J.; Fu, Q.

    2013-06-01

    Seasonal snow samples obtained at 46 sites in 6 provinces of China in January and February 2010 were analyzed for a suite of chemical species and these data are combined with previously determined concentrations of insoluble light-absorbing particles (ILAP), including all particles that absorb light in the 650-700 nm wavelength interval. The ILAP, together with 14 other analytes, are used as input to a positive matrix factorization (PMF) receptor model to explore the sources of ILAP in the snow. The PMF analysis for ILAP sources is augmented with backward trajectory cluster analysis and the geographic locations of major source areas for the three source types. The two analyses are consistent and indicate that three factors/sources were responsible for the measured light absorption of snow: a soil dust source, an industrial pollution source, and a biomass and / or biofuel burning source. Soil dust was the main source of the ILAP, accounting for ~53% of ILAP on average.

  16. Source attribution of insoluble light-absorbing particles in seasonal snow across northern China

    Directory of Open Access Journals (Sweden)

    R. Zhang

    2013-06-01

    Full Text Available Seasonal snow samples obtained at 46 sites in 6 provinces of China in January and February 2010 were analyzed for a suite of chemical species and these data are combined with previously determined concentrations of insoluble light-absorbing particles (ILAP, including all particles that absorb light in the 650–700 nm wavelength interval. The ILAP, together with 14 other analytes, are used as input to a positive matrix factorization (PMF receptor model to explore the sources of ILAP in the snow. The PMF analysis for ILAP sources is augmented with backward trajectory cluster analysis and the geographic locations of major source areas for the three source types. The two analyses are consistent and indicate that three factors/sources were responsible for the measured light absorption of snow: a soil dust source, an industrial pollution source, and a biomass and / or biofuel burning source. Soil dust was the main source of the ILAP, accounting for ~53% of ILAP on average.

  17. National synchrotron light source basic design and project status

    International Nuclear Information System (INIS)

    van Steenbergen, A.

    1981-01-01

    A summary description and the basic design parameters of the National Synchrotron Light Source, a facility for the generation of intense synchrotron radiation in the vuv and x-ray range is presented, the parameters of the sources are given, the presently planned facility beam lines are tabulated and the status of the project is indicated

  18. Externalities - an analysis using the EU ExternE-results

    International Nuclear Information System (INIS)

    2003-10-01

    The EU project ExternE quantified the externalities for the different energy technologies. In this work, the ExternE results are used in a MARKAL-analysis for the Nordic countries. The analysis does not go into detail, but gives some interesting indications: The external costs are not fully covered in the Nordic energy systems, the present taxes and charges are not high enough. The emissions from the energy systems would be strongly reduced, if taxes/environmental charges were set at the level ExternE calculate. The emissions from power production would be reduced most. Renewable energy sources and natural gas dominate the energy systems in the ExternE case

  19. Effects of neutron spectrum and external neutron source on neutron multiplication parameters in accelerator-driven system

    International Nuclear Information System (INIS)

    Shahbunder, Hesham; Pyeon, Cheol Ho; Misawa, Tsuyoshi; Lim, Jae-Yong; Shiroya, Seiji

    2010-01-01

    The neutron multiplication parameters: neutron multiplication M, subcritical multiplication factor k s , external source efficiency φ*, play an important role for numerical assessment and reactor power evaluation of an accelerator-driven system (ADS). Those parameters can be evaluated by using the measured reaction rate distribution in the subcritical system. In this study, the experimental verification of this methodology is performed in various ADS cores; with high-energy (100 MeV) proton-tungsten source in hard and soft neutron spectra cores and 14 MeV D-T neutron source in soft spectrum core. The comparison between measured and calculated multiplication parameters reveals a maximum relative difference in the range of 6.6-13.7% that is attributed to the calculation nuclear libraries uncertainty and accuracy for energies higher than 20 MeV and also dependent on the reaction rate distribution position and count rates. The effects of different core neutron spectra and external neutron sources on the neutron multiplication parameters are discussed.

  20. The synchrotron light source ROSY

    International Nuclear Information System (INIS)

    Einfeld, D.; Buettig, H.; Dienel, S.; Glaeser, W.; Goetz, T.; Guratzsch, H.; Hartmann, B.; Janssen, D.; Krug, H.; Linnemann, J.; Matz, W.; Murphy, J.B.; Neumann, W.; Oehme, W.; Picard, M.; Plesko, M.; Proehl, D.; Schlenk, R.; Tomassini, D.; Tyrroff, H.

    1994-01-01

    ROSY, a 3rd generation synchrotron light source, has been proposed to be built at the Research Center Rossendorf/Dresden in Germany. With its low emittance and optimized space for installing insertion devices ROSY will be the first synchrotron radiation source in the 3 GeV range in Europe, dedicated to materials research and industrial application. The critical wavelength of the synchrotron radiation spectra was designed to be 0.15 nm corresponding to a critical photon energy of 8.4 keV. It is proposed to use a ''modified multiple bend achromat'' (MBA) lattice in order to get a compact machine as well as a low emittance. For 3 GeV an emittance smaller than 30π nm rad can be obtained. With a fourfold symmetry and two larger straight sections within the achromatic arcs the circumference is 148 m. 23% of the circumference can be used for installing insertion devices. (orig.)

  1. 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.

  2. The study of LED light source illumination conditions for ideal algae cultivation

    Science.gov (United States)

    Tsai, Chun-Chin; Huang, Chien-Fu; Chen, Cin-Fu; Yue, Cheng-Feng

    2017-02-01

    Utilizing LED light source modules with 3 different RGB colors, the illumination effect of different wavelengths had been investigated on the growth curve of the same kind of micro algae. It was found that the best micro algae culturing status came out with long wavelength light such as red light (650 670 nm). Based on the same condition for a period of 3 weeks , the grown micro algae population density ratio represented by Optical Density (O.D.) ratio is 1?0.4?0.7 corresponding to growth with Red, Green, Blue light sources, respectively. Mixing 3 types and 2 types of LEDs with different parameters, the grown micro algae population densities were compared in terms of O.D. Interestingly enough, different light sources resulted in significant discoloration on micro algae growth, appearing yellow, brown, green, etc. Our experiments results showed such discoloration effect is reversible. Based on the same lighting condition, micro algae growth can be also affected by incubator size, nutrition supply, and temperature variation. In recent years, micro algae related technologies have been international wise a hot topic of energy and environmental protection for research and development institutes, and big energy companies among those developed countries. There will be an economically prosperous future. From this study of LED lighting to ideal algae cultivation, it was found that such built system would be capable of optimizing artificial cultivation system, leading to economic benefits for its continuous development. Since global warming causing weather change, accompanying with reducing energy sources and agriculture growth shortage are all threatening human being survival.

  3. Effects of monochromatic light sources on sex hormone levels in serum and on semen quality of ganders.

    Science.gov (United States)

    Chang, Shen-Chang; Zhuang, Zi-Xuan; Lin, Min-Jung; Cheng, Chuen-Yu; Lin, Tsung-Yi; Jea, Yu-Shine; Huang, San-Yuan

    2016-04-01

    Light is an essential external factor influencing various physiological processes, including reproductive performance, in birds. Although several attempts have been made to understand the effect of light on poultry production, the effect of light of a particular wavelength (color) on the reproductive function in geese remains unclear. This study evaluated the effect of various monochromatic light sources on the levels of sex hormone and on semen quality of ganders. Of 30 male White Roman geese in their third reproductive season (average age=3 years), 27 were divided into three groups receiving monochromatic white or red or blue lights. The birds were kept in an environmentally controlled house with a lighting photoperiod of 7L:17D for six weeks as the adaptation period. The photoperiod was subsequently changed to 9L:15D and maintained for 24 weeks. Three ganders at the beginning of the study and three from each group at the end of the adjusting period and the 20th and 30th week of the study period were sacrificed, and their testes and blood samples were collected for determining the sex hormone levels. Semen samples were collected for determining semen quality parameters, including the semen collection index, sperm concentration, semen volume, sperm motility, sperm viability, sperm morphology, and semen quality factor. The results showed that the testosterone and estradiol levels remained unchanged in all three groups at all time points. The ratio of testosterone to estradiol of ganders exposed to white light was significantly higher than that of ganders exposed to red light at the 30th week (PSemen collection index and sperm viability of ganders exposed to blue light were significantly the lowest (Psemen quality than that with red or blue lights in ganders. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. SOILD: A computer model for calculating the effective dose equivalent from external exposure to distributed gamma sources in soil

    International Nuclear Information System (INIS)

    Chen, S.Y.; LePoire, D.; Yu, C.; Schafetz, S.; Mehta, P.

    1991-01-01

    The SOLID computer model was developed for calculating the effective dose equivalent from external exposure to distributed gamma sources in soil. It is designed to assess external doses under various exposure scenarios that may be encountered in environmental restoration programs. The models four major functional features address (1) dose versus source depth in soil, (2) shielding of clean cover soil, (3) area of contamination, and (4) nonuniform distribution of sources. The model is also capable of adjusting doses when there are variations in soil densities for both source and cover soils. The model is supported by a data base of approximately 500 radionuclides. 4 refs

  5. Determination of illuminants representing typical white light emitting diodes sources

    DEFF Research Database (Denmark)

    Jost, S.; Ngo, M.; Ferrero, A.

    2017-01-01

    is to develop LED-based illuminants that describe typical white LED products based on their Spectral Power Distributions (SPDs). Some of these new illuminants will be recommended in the update of the CIE publication 15 on colorimetry with the other typical illuminants, and among them, some could be used......Solid-state lighting (SSL) products are already in use by consumers and are rapidly gaining the lighting market. Especially, white Light Emitting Diode (LED) sources are replacing banned incandescent lamps and other lighting technologies in most general lighting applications. The aim of this work...... to complement the CIE standard illuminant A for calibration use in photometry....

  6. Beam shaping of light sources using circular photonic crystal funnel

    Science.gov (United States)

    Kumar, Mrityunjay; Kumar, Mithun; Dinesh Kumar, V.

    2012-10-01

    A novel two-dimensional circular photonic crystal (CPC) structure with a sectorial opening for shaping the beam of light sources was designed and investigated. When combined with light sources, the structure acts like an antenna emitting a directional beam which could be advantageously used in several nanophotonic applications. Using the two-dimensional finite-difference time-domain (2D FDTD) method, we examined the effects of geometrical parameters of the structure on the directional and transmission properties of emitted radiation. Further, we examined the transmitting and receiving properties of a pair of identical structures as a function of distance between them.

  7. Industrial applications of micro/nanofabrication at Singapore Synchrotron Light Source

    International Nuclear Information System (INIS)

    Jian, L K; Casse, B D F; Heussler, S P; Kong, J R; Saw, B T; Mahmood, Shahrain bin; Moser, H O

    2006-01-01

    SSLS (Singapore Synchrotron Light Source) has set up a complete one-stop shop for micro/nanofabrication in the framework of the LIGA process. It is dubbed LiMiNT for Lithography for Micro and Nanotechnology and allows complete prototyping using the integral cycle of the LIGA process for producing micro/nanostructures from mask design/fabrication over X-ray lithography to electroplating in Ni, Cu, or Au, and, finally, hot embossing in a wide variety of plastics as one of the capabilities to cover a wide range of application fields and to go into higher volume production. The process chain also includes plasma cleaning and sputtering as well as substrate preparation processes including metal buffer layers, plating bases, and spin coating, polishing, and dicing. Furthermore, metrology using scanning electron microscopy (SEM), optical profilometry, and optical microscopy is available. LiMiNT is run as a research lab as well as a foundry. In this paper, several industrial applications will be presented, in which LiMiNT functions as a foundry to provide external customers the micro/nano fabrication services. These services include the fabrication of optical or X-ray masks, of micro/nano structures from polymers or from metals and of moulds for hot embossing or injection moulding

  8. Consideration of a non-baked start-up of a synchrotron light source

    International Nuclear Information System (INIS)

    Hori, Y.; Kobayashi, M.

    1996-01-01

    Vacuum baking of large complex uhv devices, such as synchrotron light sources, requires both careful design and consideration of potential problems regarding the operation and maintenance of the device. Intense synchrotron irradiation can be utilized for degassing; it is indeed necessary to achieve the required operating pressure in most light sources. To examine a non-baked start-up, the outgassing of non-baked chambers by SR irradiation was measured. Also, a non-baked start-up was carried out at the Photon Factory ring. Both results demonstrate the feasibility of a non-baked start-up of a light source. The experiments and results are described, together with several other problems which must be solved for a non-baked start-up. (Author)

  9. Aerosol behavior and light water reactor source terms

    International Nuclear Information System (INIS)

    Abbey, F.; Schikarski, W.O.

    1988-01-01

    The major developments in nuclear aerosol modeling following the accident to pressurized water reactor Unit 2 at Three Mile Island are briefly reviewed and the state of the art summarized. The importance and implications of these developments for severe accident source terms for light water reactors are then discussed in general terms. The treatment is not aimed at identifying specific source term values but is intended rather to illustrate trends, to assess the adequacy of the understanding of major aspects of aerosol behavior for source term prediction, and demonstrate in qualitative terms the effect of various aspects of reactor design. Areas where improved understanding of aerosol behavior might lead to further reductions in current source terms predictions are also considered

  10. Monochromatic light-emitting diode (LED source in layers hens during the second production cycle

    Directory of Open Access Journals (Sweden)

    Rodrigo Borille

    2015-09-01

    Full Text Available ABSTRACTLight is an important environmental factor for birds, allowing not only their vision, but also influencing their physiological responses, such as behavioral and reproductive activity. The objective of this experiment was to evaluate the impact of different colors of monochromatic light (LED sources in laying hens production during the second laying cycle. The study was conducted in an experimental laying house during 70 days. A total of 300 laying hens Isa Brown® genetic strain, aged 95 weeks, in the second laying cycle were used in the study. The artificial light sources used were blue, yellow, green, red and white. The light regimen was continuous illumination of 17 h per day (12 h natural and 5 h artificial in a daily light regimen of 17L:5D (light: dark. The Latin Square design was adopted with five treatments (five colors divided into five periods, and five boxes, with six replicates of ten birds in each box. The production and egg quality were evaluated. The different colors of light source did not affect production parameters or egg quality (p > 0.05. The monochromatic light source may be considered as an alternative to artificial lighting in laying hens during the second production cycle.

  11. Scattering and radiative properties of semi-external versus external mixtures of different aerosol types

    International Nuclear Information System (INIS)

    Mishchenko, Michael I.; Liu Li; Travis, Larry D.; Lacis, Andrew A.

    2004-01-01

    The superposition T-matrix method is used to compute the scattering of unpolarized light by semi-external aerosol mixtures in the form of polydisperse, randomly oriented two-particle clusters with touching components. The results are compared with those for composition-equivalent external aerosol mixtures, in which the components are widely separated and scatter light in isolation from each other. It is concluded that aggregation is likely to have a relatively weak effect on scattering and radiative properties of two-component tropospheric aerosols and can be replaced by the much simpler external-mixture model in remote sensing studies and atmospheric radiation balance computations

  12. Biomass and pigments production in photosynthetic bacteria wastewater treatment: effects of light sources.

    Science.gov (United States)

    Zhou, Qin; Zhang, Panyue; Zhang, Guangming

    2015-03-01

    This study is aimed at enhancing biomass and pigments production together with pollution removal in photosynthetic bacteria (PSB) wastewater treatment via different light sources. Red, yellow, blue, white LED and incandescent lamp were used. Results showed different light sources had great effects on the PSB. PSB had the highest biomass production, COD removal and biomass yield with red LED. The corresponding biomass, COD removal and biomass yield reached 2580 mg/L, 88.6% and 0.49 mg-biomass/mg-COD-removal, respectively. The hydraulic retention time of wastewater treatment could be shortened to 72 h with red LED. Mechanism analysis showed higher ATP was produced with red LED than others. Light sources could significantly affect the pigments production. The pigments productions were greatly higher with LED than incandescent lamp. Yellow LED had the highest pigments production while red LED produced the highest carotenoid/bacteriochlorophyll ratio. Considering both efficiency and energy cost, red LED was the optimal light source. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. New generation of light sources: Present and future

    International Nuclear Information System (INIS)

    Couprie, M.E.

    2014-01-01

    Spectroscopy and imaging in the VUV–X-ray domain are very sensitive tools for the investigation of the properties of matter [1–3]. Time-resolved studies enable to follow the movies of ultra-fast reactions. More than fifty years after the laser discovery [4], VUVX light sources are actively developed around the world. Among them, high order harmonics generated in gas, X-ray lasers, synchrotron radiation, free electron lasers are providing a wide offer, from laboratory size sources to large scale facilities, with various features, suitable for different types of experiments. The properties of these sources are here reviewed. Quest of new performances and flexibility is also discussed

  14. Fabrication of Random Microwell Arrays as Pseudo-Thermal Speckle Light Source

    Directory of Open Access Journals (Sweden)

    Axiu Cao

    2018-05-01

    Full Text Available Quantum correlated imaging using the intensity fluctuations of thermal light possesses advantages of high resolution and strong anti-interference ability. The common method to produce pseudo-thermal light source is using a rotary ground glass and transmission of laser beam. In the present work, we propose a method for the fabrication of microwell arrays with randomly varied diameters, which could be used as a new structural element for pseudo-thermal speckle light source. If these are etched with random sizes then they may also have random and complex varying curvatures (diffusion limited etching leading to random destructive interference of the coherent beam which could be a good thing. The microwell arrays, with diameters randomly varying from 5 μm to 40 μm, height varying from 200 nm to 20 μm, were fabricated by photolithography combined with acid etching. The experimental conditions are simple and can be scaled up to for large structures. The produced microwell arrays can transform the laser beam to a pseudo-thermal light source with a certain divergent angle by rational designing of mask and adjustable process parameters.

  15. Simulated and measured neutron/gamma light output distribution for poly-energetic neutron/gamma sources

    Science.gov (United States)

    Hosseini, S. A.; Zangian, M.; Aghabozorgi, S.

    2018-03-01

    In the present paper, the light output distribution due to poly-energetic neutron/gamma (neutron or gamma) source was calculated using the developed MCNPX-ESUT-PE (MCNPX-Energy engineering of Sharif University of Technology-Poly Energetic version) computational code. The simulation of light output distribution includes the modeling of the particle transport, the calculation of scintillation photons induced by charged particles, simulation of the scintillation photon transport and considering the light resolution obtained from the experiment. The developed computational code is able to simulate the light output distribution due to any neutron/gamma source. In the experimental step of the present study, the neutron-gamma discrimination based on the light output distribution was performed using the zero crossing method. As a case study, 241Am-9Be source was considered and the simulated and measured neutron/gamma light output distributions were compared. There is an acceptable agreement between the discriminated neutron/gamma light output distributions obtained from the simulation and experiment.

  16. RECENT BEAM MEASUREMENTS AND NEW INSTRUMENTATION AT THE ADVANCED LIGHT SOURCE

    International Nuclear Information System (INIS)

    Sannibale, Fernando; Baptiste, Kenneth; Barry, Walter; Chin, Michael; Filippetto, Daniele; Jaegerhofer, Lukas; Julian, James; Kwiatkowski, Slawomir; Low, Raymond; Plate, David; Portmann, Gregory; Robin, David; Scarvie, Tomas; Stupakov, Gennady; Weber, Jonah; Zolotorev, Max

    2008-01-01

    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

  17. Status report on the ADVANCED LIGHT SOURCE control system

    International Nuclear Information System (INIS)

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

    1992-01-01

    This paper is a status report on the ADVANCED LIGHT SOURCE (ALS) control system. The current status, performance data, and future plans will be discussed. Manpower, scheduling, and costs issues are addressed. (author)

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    Victor Smaluk

    2015-06-01

    Full Text Available 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.

  20. 4th generation light source instrumentation

    International Nuclear Information System (INIS)

    Lumpkin, A.

    1998-01-01

    This working group on 4th Generation Light Source (4GLS) Instrumentation was a follow-up to the opening-discussion on Challenges in Beam Profiling. It was in parallel with the Feedback Systems session. We filled the SSRL Conference Room with about 25 participants. The session opened with an introduction by Lumpkin. The target beam parameter values for a few-angstrom, self-amplified spontaneous emissions (SASE) experiment and for a diffraction-limited soft x-ray storage ring source were addressed. Instrument resolution would of course need to be 2-3 times better than the value measured, if possible. The nominal targeted performance parameters are emittance (1-2π mm mrad), bunch length (100 fs), peak-current (l-5 kA), beam size (10 microm), beam divergence (1 microrad), energy spread (2 x 10 -4 ), and beam energy (10's of GeV). These are mostly the SASE values, and the possible parameters for a diffraction-limited soft x-ray source would be relaxed somewhat. Beam stability and alignment specifications in the sub-micron domain for either device are anticipated

  1. Conjugation of fiber-coupled wide-band light sources and acousto-optical spectral elements

    Science.gov (United States)

    Machikhin, Alexander; Batshev, Vladislav; Polschikova, Olga; Khokhlov, Demid; Pozhar, Vitold; Gorevoy, Alexey

    2017-12-01

    Endoscopic instrumentation is widely used for diagnostics and surgery. The imaging systems, which provide the hyperspectral information of the tissues accessible by endoscopes, are particularly interesting and promising for in vivo photoluminescence diagnostics and therapy of tumour and inflammatory diseases. To add the spectral imaging feature to standard video endoscopes, we propose to implement acousto-optical (AO) filtration of wide-band illumination of incandescent-lamp-based light sources. To collect maximum light and direct it to the fiber-optic light guide inside the endoscopic probe, we have developed and tested the optical system for coupling the light source, the acousto-optical tunable filter (AOTF) and the light guide. The system is compact and compatible with the standard endoscopic components.

  2. Paul Scherrer Institute Scientific Report 1999. Volume VII: Swiss Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Weyer, Heinz Josef; Bugmann, Marlen; Schuetz, Christine [eds.

    2000-07-01

    The Swiss Synchrotron 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. The progress of the construction of pre-injector, booster and storage ring as well as some of the details of new features that were adopted for the design and operation of this machine, are described in this annual report for 1999. An overview of the concept and status of the four SLS beamlines and the related infrastructure is also given. The last chapter contains 11 contributions which report on scientific activities of SLS staff members at synchrotron radiation facilities all over the world.

  3. Paul Scherrer Institute Scientific Report 1999. Volume VII: Swiss Light Source

    International Nuclear Information System (INIS)

    Weyer, Heinz Josef; Bugmann, Marlen; Schuetz, Christine

    2000-01-01

    The Swiss Synchrotron 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. The progress of the construction of pre-injector, booster and storage ring as well as some of the details of new features that were adopted for the design and operation of this machine, are described in this annual report for 1999. An overview of the concept and status of the four SLS beamlines and the related infrastructure is also given. The last chapter contains 11 contributions which report on scientific activities of SLS staff members at synchrotron radiation facilities all over the world

  4. Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal.

    Science.gov (United States)

    Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

    2015-04-01

    The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49-5.99 g N/(kg MLVSS⋅h) (MLVSS is mixed liquor volatile suspended solids) and 6.63-6.81 g N/(kg MLVSS⋅h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes.

  5. Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal*

    Science.gov (United States)

    Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

    2015-01-01

    The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49–5.99 g N/(kg MLVSS∙h) (MLVSS is mixed liquor volatile suspended solids) and 6.63–6.81 g N/(kg MLVSS∙h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes. PMID:25845364

  6. Status of the National Synchrotron Light Source project

    International Nuclear Information System (INIS)

    Heese, R.N.

    1981-01-01

    The National Synchrotron Light Source is in its final stages of construction, and as the turn-on time for the 700 MeV vuv storage ring draws near, an overview of the project is presented. Emphasis is placed on the linac and booster synchrotron performance and the status of major subsystems

  7. A mobile light source for carbon/nitrogen cameras

    International Nuclear Information System (INIS)

    Trower, W.P.; Melekhin, V.N.; Shvedunov, V.I.; Sobenin, N.P.

    1995-01-01

    The pulsed light source for carbon/nitrogen cameras developed to image concealed narcotics/explosives is described. This race-track microtron will produce 40 mA pulses of 70 MeV electrons, have minimal size and weight, and maximal ruggedness and reliability, so that it can be transported on a truck. (orig.)

  8. A mobile light source for carbon/nitrogen cameras

    Science.gov (United States)

    Trower, W. P.; Karev, A. I.; Melekhin, V. N.; Shvedunov, V. I.; Sobenin, N. P.

    1995-05-01

    The pulsed light source for carbon/nitrogen cameras developed to image concealed narcotics/explosives is described. This race-track microtron will produce 40 mA pulses of 70 MeV electrons, have minimal size and weight, and maximal ruggedness and reliability, so that it can be transported on a truck.

  9. Advanced Light Source beam position monitor

    International Nuclear Information System (INIS)

    Hinkson, J.

    1991-01-01

    The Advanced Light Source (ALS) is a synchrotron radiation facility nearing completion at LBL. As a third-generation machine, the ALS is designed to produce intense light from bend magnets, wigglers, and undulators (insertion devices). The facility will include a 50 MeV electron linear accelerator, a 1.5 GeV booster synchrotron, beam transport lines, a 1--2 GeV storage ring, insertion devices, and photon beam lines. Currently, the beam injection systems are being commissioned, and the storage ring is being installed. Electron beam position monitors (BPM) are installed throughout the accelerator and constitute the major part of accelerator beam diagnostics. The design of the BPM instruments is complete, and 50 units have been constructed for use in the injector systems. We are currently fabricating 100 additional instruments for the storage ring. In this paper I discuss engineering fabrication, testing and performance of the beam pickup electrodes and the BPM electronics

  10. SymPS: BRDF Symmetry Guided Photometric Stereo for Shape and Light Source Estimation.

    Science.gov (United States)

    Lu, Feng; Chen, Xiaowu; Sato, Imari; Sato, Yoichi

    2018-01-01

    We propose uncalibrated photometric stereo methods that address the problem due to unknown isotropic reflectance. At the core of our methods is the notion of "constrained half-vector symmetry" for general isotropic BRDFs. We show that such symmetry can be observed in various real-world materials, and it leads to new techniques for shape and light source estimation. Based on the 1D and 2D representations of the symmetry, we propose two methods for surface normal estimation; one focuses on accurate elevation angle recovery for surface normals when the light sources only cover the visible hemisphere, and the other for comprehensive surface normal optimization in the case that the light sources are also non-uniformly distributed. The proposed robust light source estimation method also plays an essential role to let our methods work in an uncalibrated manner with good accuracy. Quantitative evaluations are conducted with both synthetic and real-world scenes, which produce the state-of-the-art accuracy for all of the non-Lambertian materials in MERL database and the real-world datasets.

  11. Simulations of Gamma-Ray Burst Jets in a Stratified External Medium: Dynamics, Afterglow Light Curves, Jet Breaks, and Radio Calorimetry

    Science.gov (United States)

    De Colle, Fabio; Ramirez-Ruiz, Enrico; Granot, Jonathan; Lopez-Camara, Diego

    2012-05-01

    The dynamics of gamma-ray burst (GRB) jets during the afterglow phase is most reliably and accurately modeled using hydrodynamic simulations. All published simulations so far, however, have considered only a uniform external medium, while a stratified external medium is expected around long duration GRB progenitors. Here, we present simulations of the dynamics of GRB jets and the resulting afterglow emission for both uniform and stratified external media with ρextvpropr -k for k = 0, 1, 2. The simulations are performed in two dimensions using the special relativistic version of the Mezcal code. Common to all calculations is the initiation of the GRB jet as a conical wedge of half-opening angle θ0 = 0.2 whose radial profile is taken from the self-similar Blandford-McKee solution. The dynamics for stratified external media (k = 1, 2) are broadly similar to those derived for expansion into a uniform external medium (k = 0). The jet half-opening angle is observed to start increasing logarithmically with time (or radius) once the Lorentz factor Γ drops below θ-1 0. For larger k values, however, the lateral expansion is faster at early times (when Γ > θ-1 0) and slower at late times with the jet expansion becoming Newtonian and slowly approaching spherical symmetry over progressively longer timescales. We find that, contrary to analytic expectations, there is a reasonably sharp jet break in the light curve for k = 2 (a wind-like external medium), although the shape of the break is affected more by the viewing angle (for θobs <= θ0) than by the slope of the external density profile (for 0 <= k <= 2). Steeper density profiles (i.e., increasing k values) are found to produce more gradual jet breaks while larger viewing angles cause smoother and later appearing jet breaks. The counterjet becomes visible as it becomes sub-relativistic, and for k = 0 this results in a clear bump-like feature in the light curve. However, for larger k values the jet decelerates more

  12. On-line spectral diagnostic system for Dalian Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chaoyang; Wei, Shen; Du, Xuewei [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Du, Liangliang [National Synchrotron Radiation Laboratory, University of Science & Technology of China, Hefei, Anhui 230029 (China); Wang, Qiuping, E-mail: qiuping@ustc.edu.cn [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Zhang, Weiqing; Wu, Guorong; Dai, Dongxu [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Yang, Xueming, E-mail: xmyang@dicp.ac.cn [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)

    2015-05-21

    The Dalian Coherent Light Source (DCLS) is a Free electron laser (FEL) user facility currently under construction in the northeast of China. It is designed to work on high gain high harmonic principle with the capability of wavelength continuously tunable in the EUV regime of 50–150 nm. The light source has unique features such as the turntable radiation frequency, wide spectral range, high brightness and peak power, very short pulse time structure, etc. A key diagnostic task in DCLS is the on-line source spectral characteristic recording during the source development, and for the definition of the experimental conditions. For this purpose, an online grazing incidence spectrometer with a toroidal mirror and a variable-line-spacing plane grating is designed and presented in this paper to monitor each single FEL pulse. A circular stage is chosen to fit the focal curve and to realize the wavelength scanning. This scanning mechanics is simpler and stable. Resolving power (λ/Δλ) of this spectrometer is better than 12,000 in the whole wavelength range.

  13. On-line spectral diagnostic system for Dalian Coherent Light Source

    International Nuclear Information System (INIS)

    Li, Chaoyang; Wei, Shen; Du, Xuewei; Du, Liangliang; Wang, Qiuping; Zhang, Weiqing; Wu, Guorong; Dai, Dongxu; Yang, Xueming

    2015-01-01

    The Dalian Coherent Light Source (DCLS) is a Free electron laser (FEL) user facility currently under construction in the northeast of China. It is designed to work on high gain high harmonic principle with the capability of wavelength continuously tunable in the EUV regime of 50–150 nm. The light source has unique features such as the turntable radiation frequency, wide spectral range, high brightness and peak power, very short pulse time structure, etc. A key diagnostic task in DCLS is the on-line source spectral characteristic recording during the source development, and for the definition of the experimental conditions. For this purpose, an online grazing incidence spectrometer with a toroidal mirror and a variable-line-spacing plane grating is designed and presented in this paper to monitor each single FEL pulse. A circular stage is chosen to fit the focal curve and to realize the wavelength scanning. This scanning mechanics is simpler and stable. Resolving power (λ/Δλ) of this spectrometer is better than 12,000 in the whole wavelength range

  14. Endoscopic hyperspectral imaging: light guide optimization for spectral light source

    Science.gov (United States)

    Browning, Craig M.; Mayes, Samuel; Rich, Thomas C.; Leavesley, Silas J.

    2018-02-01

    Hyperspectral imaging (HSI) is a technology used in remote sensing, food processing and documentation recovery. Recently, this approach has been applied in the medical field to spectrally interrogate regions of interest within respective substrates. In spectral imaging, a two (spatial) dimensional image is collected, at many different (spectral) wavelengths, to sample spectral signatures from different regions and/or components within a sample. Here, we report on the use of hyperspectral imaging for endoscopic applications. Colorectal cancer is the 3rd leading cancer for incidences and deaths in the US. One factor of severity is the miss rate of precancerous/flat lesions ( 65% accuracy). Integrating HSI into colonoscopy procedures could minimize misdiagnosis and unnecessary resections. We have previously reported a working prototype light source with 16 high-powered light emitting diodes (LEDs) capable of high speed cycling and imaging. In recent testing, we have found our current prototype is limited by transmission loss ( 99%) through the multi-furcated solid light guide (lightpipe) and the desired framerate (20-30 fps) could not be achieved. Here, we report on a series of experimental and modeling studies to better optimize the lightpipe and the spectral endoscopy system as a whole. The lightpipe was experimentally evaluated using an integrating sphere and spectrometer (Ocean Optics). Modeling the lightpipe was performed using Monte Carlo optical ray tracing in TracePro (Lambda Research Corp.). Results of these optimization studies will aid in manufacturing a revised prototype with the newly designed light guide and increased sensitivity. Once the desired optical output (5-10 mW) is achieved then the HIS endoscope system will be able to be implemented without adding onto the procedure time.

  15. 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.

  16. Swiss Light Source SLS

    International Nuclear Information System (INIS)

    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

  17. Design, commissioning and operation of the Swiss Light Source SLS

    International Nuclear Information System (INIS)

    Streun, Andreas

    2003-01-01

    The Swiss Light Source (SLS) at the Paul Scherrer Institute (PSI) is the most recent 3rd generation light source coming to operation. It consists of a 12- TBA storage ring of 288 m circumference providing 5 nm rad emittance at 2.4 GeV, a novel type of full energy booster synchrotron and a 100 MeV linac. The initial four beamlines cover protein X-ray crystallography (PX), materials science (MS), surface and interface spectroscopy (SIS) and microscopy (SIM). We will review the project history, describe the design concepts of the accelerators and the technical subsystems, and report on the commissioning process and the status of operation by end of 2002. (author)

  18. 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.

  19. Light transfer through windows with external condensation

    Science.gov (United States)

    Zhu, Keyong; Li, Shaoling; Pilon, Laurent

    2018-03-01

    This study investigates systematically light transfer through windows supporting cap-shaped droplets on their external face. The presence of such droplets may have negative effects on the conversion efficiency of solar cells, distorts image quality of lenses, or hinders visibility through windows and windshields. Here, the directional-hemispherical transmittance was predicted by the Monte Carlo ray-tracing method. The droplets were monodisperse or polydisperse randomly distributed on the outside face of optically smooth windows. For nonabsorbing droplets, the diameter and size distribution did not have a significant effect on the window directional-hemispherical transmittance. The latter was nearly independent of contact angle for incident angle θi ≤ 30°. However, the directional-hemispherical transmittance decreased monotonously with increasing incident angle and droplet contact angle for contact angle θc ≤ 70° to reach a minimum at a contact angle θc,min beyond which it increased with increasing contact angle before reaching a plateau at large contact angles. This was attributed to total internal reflection at the back window/air and droplet/air interfaces. For absorbing droplets, the normal-hemispherical transmittance decreased significantly with increasing droplet contact angle, mean diameter, polydispersity, and projected surface area coverage due to strong absorption within the droplets. Moreover, the normal-hemispherical transmittance decreased with increasing contact angle for θcmean diameter, and contact angle for θc ≥ 90°. Finally, Analytical expressions for the upper and lower bounds of the normal-hemispherical transmittance as a function of droplet contact angle, optical properties, and projected surface area coverage were derived.

  20. 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....

  1. Aspects of a new light source

    International Nuclear Information System (INIS)

    Bagley, G.P.

    1980-01-01

    The National Synchrotron Light Source, under construction at Brookhaven Laboratory, will be a uniquely copious source of x-ray and ultraviolet photons with a wide spectrum. Some of the potential uses of this intense radiation include studies of absorption spectra, photoemission of electrons, x-ray scattering, biochemical studies and other areas of basic research. It can also be used for micro-lithography of integrated circuits for ultra dense semiconductor devices. The basic operation of the electron synchrotron is described. This includes the three step acceleration of the electrons thru a linear accelerator, a booster synchrotron and finally in a synchrotron storage ring. The synchrotron magnet power system, the responsibility of a black engineer, is described. An SCR chopper approach is used with precision components to achieve current stability and repeatability of .01%. This current generates the magnetic fields which bend and focus the electron beam

  2. Aspects of a new light source

    International Nuclear Information System (INIS)

    Bagley, G.P.

    1978-01-01

    The National Synchrotron Light Source, under construction at Brookhaven Laboratory, will be a uniquely copious source of x-ray and ultraviolet photons with a wide spectrum. Some of the potential uses of this intense radiation include studies of absorption spectra, photo-emission of electrons, x-ray scattering, biochemical studies and other areas of basic research. It can also be used for micro-lithography of integrated circuits for ultra dense semiconductor devices. The basic operation of the electron synchrotron is described. This includes the three step acceleration of the electrons through a linear accelerator, a booster synchrotron and finally in a synchrotron storage ring. The synchrotron magnet power system, the responsibility of a black engineer, is described. An SCR chopper approach is used with precision components to achieve current stability and repeatability of 0.01 percent. This current generates the magnetic fields which bend and focus the electron beam

  3. On the Measurement of the Velocity of Light Emitted by an Ultrarelativistic Source

    Science.gov (United States)

    Kupryaev, N. V.

    2015-01-01

    By analytical calculations it has been shown that in papers on the measurement of the velocity of light published in 2011 in the journals Uspekhi Fizicheskikh Nauk [Physics-Uspekhi] and Pis'ma v ZhETF [JRTP Letters], in actual fact the velocity of a light pulse from a relativistic clot of electrons was not measured. All that was done was to compare the velocity of light emitted by an ultrarelativistic source with the velocity of light from a fixed source, i.e., both in the first and second variants (one independent quantity was compared with another), in essence, it was simply postulated. In the first variant a glass plate was used as the fixed light source, and in the second variants, a synchrotron pulse was used as the reference signal. The velocity of light was calculated using a calculated time based on the postulate of the special theory of relativity (STR) on the invariance of the velocity of light. This, of course, contradicts the Newton-Ritz hypothesis on ballistic addition of velocities, but at the present time this idea is not taken seriously. Practically none of the serious contemporary critics of STR, apart, of course, from amateurs, holds this point of view. The result cannot be considered as a direct experimental confirmation of the second postulate of Einstein's special theory of relativity, i.e., its main part, which speaks of the constancy of the velocity of light in all inertial reference frames, but only of that part which speaks of the independence of the velocity of light on motion of the source. Moreover, this same result stands as equal proof of the so-called theory of the luminiferous ether, which held sway up to the creation of the special theory of relativity and which has now been revived, i.e., it does not distinguish between these two theories. It is fundamentally impossible in principle to measure the velocity of light by the proposed method, it is only possible to postulate it.

  4. Advances in broad bandwidth light sources for ultrahigh resolution optical coherence tomography

    International Nuclear Information System (INIS)

    Unterhuber, A; Povazay, B; Bizheva, K; Hermann, B; Sattmann, H; Stingl, A; Le, T; Seefeld, M; Menzel, R; Preusser, M; Budka, H; Schubert, Ch; Reitsamer, H; Ahnelt, P K; Morgan, J E; Cowey, A; Drexler, W

    2004-01-01

    Novel ultra-broad bandwidth light sources enabling unprecedented sub-2 μm axial resolution over the 400 nm-1700 nm wavelength range have been developed and evaluated with respect to their feasibility for clinical ultrahigh resolution optical coherence tomography (UHR OCT) applications. The state-of-the-art light sources described here include a compact Kerr lens mode locked Ti:sapphire laser (λ c = 785 nm, Δλ = 260 nm, P out = 50 mW) and different nonlinear fibre-based light sources with spectral bandwidths (at full width at half maximum) up to 350 nm at λ c = 1130 nm and 470 nm at λ c = 1375 nm. In vitro UHR OCT imaging is demonstrated at multiple wavelengths in human cancer cells, animal ganglion cells as well as in neuropathologic and ophthalmic biopsies in order to compare and optimize UHR OCT image contrast, resolution and penetration depth

  5. Future Synchrotron Light Sources Based on Ultimate Storage Rings

    International Nuclear Information System (INIS)

    Cai, Yunhai

    2012-01-01

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

  6. 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

  7. Consideration of external hazards and multi-source interactions in the USNRC's site level 3 PSA project

    International Nuclear Information System (INIS)

    Siu, N.; Stutzke, M.; Drouin, M.; Tobin, K.; Coyne, K.; Kuritzky, A.

    2014-01-01

    U.S.NRC launched a project in September 2011 to evaluate the total risk at a selected reference NPP (the Vogtle plant) according to the entire initiators, including external hazards. The scope of this risk evaluation was given as 'reactor in all operational modes, including full power, low power and shutdown modes, spent fuel pool and dry cask storage, where all the internal and external hazards are considered'. As part of this study, an Integrated Site Risk Analysis (ISRA) addressing the combinations of and interactions between the different sources of radiological risk (reactors, spent fuel pool (SFP), dry casks) is underway. A number of modeling and implementation challenges were identified. The former include the problem of combinatorial explosion associated with the need to treat multiple sources over extended periods of time

  8. Modelling of novel light sources based on asymmetric heterostructures

    International Nuclear Information System (INIS)

    Afonenko, A.A.; Kononenko, V.K.; Manak, I.S.

    1995-01-01

    For asymmetric quantum-well heterojunction laser sources, processes of carrier injection into quantum wells are considered. In contrast to ordinary quantum-well light sources, active layers in the novel nanocrystalline systems have different thickness and/or compositions. In addition, wide-band gap barrier layers separating the quantum wells may have a linear or parabolic energy potential profile. For various kinds of the structures, mathematical simulation of dynamic response has been carried out. (author). 8 refs, 5 figs

  9. III–V quantum light source and cavity-QED on Silicon

    Science.gov (United States)

    Luxmoore, I. J.; Toro, R.; Pozo-Zamudio, O. Del; Wasley, N. A.; Chekhovich, E. A.; Sanchez, A. M.; Beanland, R.; Fox, A. M.; Skolnick, M. S.; Liu, H. Y.; Tartakovskii, A. I.

    2013-01-01

    Non-classical light sources offer a myriad of possibilities in both fundamental science and commercial applications. Single photons are the most robust carriers of quantum information and can be exploited for linear optics quantum information processing. Scale-up requires miniaturisation of the waveguide circuit and multiple single photon sources. Silicon photonics, driven by the incentive of optical interconnects is a highly promising platform for the passive optical components, but integrated light sources are limited by silicon's indirect band-gap. III–V semiconductor quantum-dots, on the other hand, are proven quantum emitters. Here we demonstrate single-photon emission from quantum-dots coupled to photonic crystal nanocavities fabricated from III–V material grown directly on silicon substrates. The high quality of the III–V material and photonic structures is emphasized by observation of the strong-coupling regime. This work opens-up the advantages of silicon photonics to the integration and scale-up of solid-state quantum optical systems. PMID:23393621

  10. III-V quantum light source and cavity-QED on silicon.

    Science.gov (United States)

    Luxmoore, I J; Toro, R; Del Pozo-Zamudio, O; Wasley, N A; Chekhovich, E A; Sanchez, A M; Beanland, R; Fox, A M; Skolnick, M S; Liu, H Y; Tartakovskii, A I

    2013-01-01

    Non-classical light sources offer a myriad of possibilities in both fundamental science and commercial applications. Single photons are the most robust carriers of quantum information and can be exploited for linear optics quantum information processing. Scale-up requires miniaturisation of the waveguide circuit and multiple single photon sources. Silicon photonics, driven by the incentive of optical interconnects is a highly promising platform for the passive optical components, but integrated light sources are limited by silicon's indirect band-gap. III-V semiconductor quantum-dots, on the other hand, are proven quantum emitters. Here we demonstrate single-photon emission from quantum-dots coupled to photonic crystal nanocavities fabricated from III-V material grown directly on silicon substrates. The high quality of the III-V material and photonic structures is emphasized by observation of the strong-coupling regime. This work opens-up the advantages of silicon photonics to the integration and scale-up of solid-state quantum optical systems.

  11. The Design, Construction and Test of stray light suppression baffles for the CHAMP satellite

    DEFF Research Database (Denmark)

    Jørgensen, John Leif

    1997-01-01

    The Advanced Stellar Compass, to be delivered from IAU to the CHAMP project, requires some kind of stray-light suppressing shade to be mounted in front of the lens, in order to minimize the thermal impact and to maximize the performance envelope when subjected to non-stellar external light sources...

  12. Dynamic response analysis of the LBL Advanced Light Source synchrotron radiation storage ring

    International Nuclear Information System (INIS)

    Leung, K.

    1993-05-01

    This paper presents the dynamic response analysis of the photon source synchrotron radiation storage ring excited by ground motion measured at the Lawrence Berkeley Laboratory advanced light source building site. The high spectral brilliance requirement the photon beams of the advanced light source storage ring specified displacement of the quadrupole focusing magnets in the order of 1 micron in vertical motion.There are 19 magnets supported by a 430-inch steel box beam girder. The girder and all magnets are supported by the kinematic mount system normally used in optical equipment. The kinematic mount called a six-strut magnet support system is now considered as an alternative system for supporting SSC magnets in the Super Collider. The effectively designed and effectively operated six-strut support system is now successfully operated for the Advanced Light Source (ALS) accelerator at the Lawrence Berkeley Laboratory. This paper will present the method of analysis and results of the dynamic motion study at the center of the magnets under the most critical excitation source as recorded at the LBL site

  13. Progress in extremely high brightness LED-based light sources

    Science.gov (United States)

    Hoelen, Christoph; Antonis, Piet; de Boer, Dick; Koole, Rolf; Kadijk, Simon; Li, Yun; Vanbroekhoven, Vincent; Van De Voorde, Patrick

    2017-09-01

    Although the maximum brightness of LEDs has been increasing continuously during the past decade, their luminance is still far from what is required for multiple applications that still rely on the high brightness of discharge lamps. In particular for high brightness applications with limited étendue, e.g. front projection, only very modest luminance values in the beam can be achieved with LEDs compared to systems based on discharge lamps or lasers. With dedicated architectures, phosphor-converted green LEDs for projection may achieve luminance values up to 200-300 Mnit. In this paper we report on the progress made in the development of light engines based on an elongated luminescent concentrator pumped by blue LEDs. This concept has recently been introduced to the market as ColorSpark High Lumen Density LED technology. These sources outperform the maximum brightness of LEDs by multiple factors. In LED front projection, green LEDs are the main limiting factor. With our green modules, we now have achieved peak luminance values of 2 Gnit, enabling LED-based projection systems with over 4000 ANSI lm. Extension of this concept to yellow and red light sources is presented. The light source efficiency has been increased considerably, reaching 45-60 lm/W for green under practical application conditions. The module architecture, beam shaping, and performance characteristics are reviewed, as well as system aspects. The performance increase, spectral range extensions, beam-shaping flexibility, and cost reductions realized with the new module architecture enable a breakthrough in LED-based projection systems and in a wide variety of other high brightness applications.

  14. Developing electron beam bunching technology for improving light sources

    International Nuclear Information System (INIS)

    Carlsten, B.E.; Chan, K.C.D.; Feldman, D.W.

    1997-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to develop a new electron bunch compression technology, experimentally demonstrate subpicosecond compression of bunches with charges on the order of 1 nC, and to theoretically investigate fundamental limitations to electron bunch compression. All of these goals were achieved, and in addition, the compression system built for this project was used to generate 22 nm light in a plasma-radiator light source

  15. Light ion source studies with a magnetically insulated extraction diode

    International Nuclear Information System (INIS)

    Struckman, C.K.

    1992-01-01

    Light ion sources are currently being studied to assess their ability to drive an inertial confinement fusion reactor. The author has produced a high purity, 1MV, 300A/cm 2 lithium beam using a 200cm 2 extraction geometry, magnetically insulated ion diode. The lithium source was an AC glow discharge cleaned, LiF/Al film active anode. The active anode plasma was formed after 50KA of current was shunted through the anode film for 20ns. The stoichiometry of the resulting ion beam was 65% Li + , 20% Al +2 , and 15% H + . Without the glow discharge cleaning, the ion beam was over 55% hydrogen and only 20% Li + . At the time of the diode's design, extraction diodes were producing poor ion beams: their current efficiency was only 60-70%, and their extracted ion current was radially nonuniform. This diode was the first high efficiency extraction diode, and produced over 200KA of ions with 80-90% ion current efficiency. In addition, by varying the tilt of the applied magnetic field, it was possible to show that the ion current density could be made independent of radius. Since the author was unable to make a Li + beam with a passive anode, he installed an active anode that used an external current to vaporize a thin metal film on the anode surface. Poor beam purity was the most serious problem with active anodes. In order to remove impurities, especially the hydrogen contamination, the author cleaned the anodes with a glow discharge. Al film anodes were cleaned with a 110mA, 33W DC glow discharge, and the LiF/Al film anodes were cleaned with an equivalent AC discharge. The results obtained and a model for the mechanism behind the cleaning process are throughly discussed

  16. A 1.5 GeV high brilliance synchrotron light source with combined function lattice

    International Nuclear Information System (INIS)

    Eriksson, M.; Lindgren, L.J.; Andersson, Aa.; Roejsel, P.; Werin, S.

    1988-01-01

    A 1.5 GeV synchrotron light source with a combined function lattice is studied. The light source will offer X-ray radiation with λc=1.0 angstrom from a superconducting wiggler and high brilliance VUV-radiation from undulators. The magnet lattice, magnet design and ring performance is discussed. (authors)

  17. Paul Scherrer Institute Scientific Report 2000. Volume VII: Swiss Light Source

    International Nuclear Information System (INIS)

    Weyer, Heinz Josef; Bugmann, Marlen; Schuetz, Christine

    2001-01-01

    The Swiss Synchrotron 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 presently being constructed at PSI. The year 2000 was crucial for maintaining the project milestones with the start of storage ring commissioning for beginning of 2001 and first light on the probe at the four beamlines of phase I for August 2001. The major goals of 2000 were the completion of accelerator installation, the commissioning of linac and booster and the beginning of beamline assembly. In the first half of the year in parallel to the installation, major fabrication procedures were going on, that had to be thoroughly followed up in order to guarantee their completion in time. The overview and detailed description of these developments is supplemented in this annual report by 8 contributions on scientific activities of SLS staff members at synchrotron radiation facilities all over the world. A list of scientific publications in 2000 is also provided

  18. Paul Scherrer Institute Scientific Report 2000. Volume VII: Swiss Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Weyer, Heinz Josef; Bugmann, Marlen; Schuetz, Christine [eds.

    2001-07-01

    The Swiss Synchrotron 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 presently being constructed at PSI. The year 2000 was crucial for maintaining the project milestones with the start of storage ring commissioning for beginning of 2001 and first light on the probe at the four beamlines of phase I for August 2001. The major goals of 2000 were the completion of accelerator installation, the commissioning of linac and booster and the beginning of beamline assembly. In the first half of the year in parallel to the installation, major fabrication procedures were going on, that had to be thoroughly followed up in order to guarantee their completion in time. The overview and detailed description of these developments is supplemented in this annual report by 8 contributions on scientific activities of SLS staff members at synchrotron radiation facilities all over the world. A list of scientific publications in 2000 is also provided.

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  20. National Synchrotron Light Source safety-analysis report

    International Nuclear Information System (INIS)

    Batchelor, K.

    1982-07-01

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

  1. Current schemes for National Synchrotron Light Source UV beamlines

    International Nuclear Information System (INIS)

    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 0 and 15 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

  2. Performance of light sources and radiation sensors under low gravity realized by parabolic airplane flights

    Science.gov (United States)

    Hirai, Hiroaki; Kitaya, Yoshiaki; Hirai, Takehiro

    A fundamental study was conducted to establish an experimental system for space farming. Since to ensure optimal light for plant cultivation in space is of grave importance, this study examined the performance of light sources and radiation sensors under microgravity conditions created during the parabolic airplane flight. Three kinds of light sources, a halogen bulb, a fluorescent tube, and blue and red LEDs, and ten models of radiation sensors available in the market were used for the experiment. Surface temperature of the light sources, output signals from the radiation sensors, spectroscopic characteristics were measured at the gravity levels of 0.01, 1.0 and 1.8 G for 20 seconds each during parabolic airplane flights. As a result, the performance of the halogen lamp was affected the most by the gravity level among the three light sources. Under the microgravity conditions which do not raise heat convection, the temperature of the halogen lamp rose and the output of the radiation sensors increased. Spectral distributions of the halogen lamp indicated that peak wavelength appeared the highest at the level of 0.01G, which contributed to the increase in light intensity. In the case of red and blue LEDs, which are promising light sources in space farming, the temperature of both LED chips rose but irradiance from red LED increased and that from blue LED decreased under microgravity conditions due to the different thermal characteristics.

  3. Fundamental and future prospects of printed ambipolar fluorene-type polymer light-emitting transistors for improved external quantum efficiency, mobility, and emission pattern

    Science.gov (United States)

    Kajii, Hirotake

    2018-05-01

    In this review, we focus on the improved external quantum efficiency, field-effect mobility, and emission pattern of top-gate-type polymer light-emitting transistors (PLETs) based on ambipolar fluorene-type polymers. A low-temperature, high-efficiency, printable red phosphorescent PLET based on poly(alkylfluorene) with modified alkyl side chains fabricated by a film transfer process is demonstrated. Device fabrication based on oriented films leads to an improved EL intensity owing to the increase in field-effect mobility. There are three factors that affect the transport of carriers, i.e., the energy level, threshold voltage, and mobility of each layer for heterostructure PLETs, which result in various emission patterns such as the line-shaped, multicolor and in-plane emission pattern in the full-channel area between source and drain electrodes. Fundamentals and future prospects in heterostructure devices are discussed and reviewed.

  4. SIMULATIONS OF GAMMA-RAY BURST JETS IN A STRATIFIED EXTERNAL MEDIUM: DYNAMICS, AFTERGLOW LIGHT CURVES, JET BREAKS, AND RADIO CALORIMETRY

    International Nuclear Information System (INIS)

    De Colle, Fabio; Ramirez-Ruiz, Enrico; Granot, Jonathan; Lopez-Camara, Diego

    2012-01-01

    The dynamics of gamma-ray burst (GRB) jets during the afterglow phase is most reliably and accurately modeled using hydrodynamic simulations. All published simulations so far, however, have considered only a uniform external medium, while a stratified external medium is expected around long duration GRB progenitors. Here, we present simulations of the dynamics of GRB jets and the resulting afterglow emission for both uniform and stratified external media with ρ ext ∝r –k for k = 0, 1, 2. The simulations are performed in two dimensions using the special relativistic version of the Mezcal code. Common to all calculations is the initiation of the GRB jet as a conical wedge of half-opening angle θ 0 = 0.2 whose radial profile is taken from the self-similar Blandford-McKee solution. The dynamics for stratified external media (k = 1, 2) are broadly similar to those derived for expansion into a uniform external medium (k = 0). The jet half-opening angle is observed to start increasing logarithmically with time (or radius) once the Lorentz factor Γ drops below θ –1 0 . For larger k values, however, the lateral expansion is faster at early times (when Γ > θ –1 0 ) and slower at late times with the jet expansion becoming Newtonian and slowly approaching spherical symmetry over progressively longer timescales. We find that, contrary to analytic expectations, there is a reasonably sharp jet break in the light curve for k = 2 (a wind-like external medium), although the shape of the break is affected more by the viewing angle (for θ obs ≤ θ 0 ) than by the slope of the external density profile (for 0 ≤ k ≤ 2). Steeper density profiles (i.e., increasing k values) are found to produce more gradual jet breaks while larger viewing angles cause smoother and later appearing jet breaks. The counterjet becomes visible as it becomes sub-relativistic, and for k = 0 this results in a clear bump-like feature in the light curve. However, for larger k values the jet

  5. SIMULATIONS OF GAMMA-RAY BURST JETS IN A STRATIFIED EXTERNAL MEDIUM: DYNAMICS, AFTERGLOW LIGHT CURVES, JET BREAKS, AND RADIO CALORIMETRY

    Energy Technology Data Exchange (ETDEWEB)

    De Colle, Fabio; Ramirez-Ruiz, Enrico [TASC, Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Granot, Jonathan [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Lopez-Camara, Diego [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Ap. 70-543, 04510 D.F. (Mexico)

    2012-05-20

    The dynamics of gamma-ray burst (GRB) jets during the afterglow phase is most reliably and accurately modeled using hydrodynamic simulations. All published simulations so far, however, have considered only a uniform external medium, while a stratified external medium is expected around long duration GRB progenitors. Here, we present simulations of the dynamics of GRB jets and the resulting afterglow emission for both uniform and stratified external media with {rho}{sub ext}{proportional_to}r{sup -k} for k = 0, 1, 2. The simulations are performed in two dimensions using the special relativistic version of the Mezcal code. Common to all calculations is the initiation of the GRB jet as a conical wedge of half-opening angle {theta}{sub 0} = 0.2 whose radial profile is taken from the self-similar Blandford-McKee solution. The dynamics for stratified external media (k = 1, 2) are broadly similar to those derived for expansion into a uniform external medium (k = 0). The jet half-opening angle is observed to start increasing logarithmically with time (or radius) once the Lorentz factor {Gamma} drops below {theta}{sup -1}{sub 0}. For larger k values, however, the lateral expansion is faster at early times (when {Gamma} > {theta}{sup -1}{sub 0}) and slower at late times with the jet expansion becoming Newtonian and slowly approaching spherical symmetry over progressively longer timescales. We find that, contrary to analytic expectations, there is a reasonably sharp jet break in the light curve for k = 2 (a wind-like external medium), although the shape of the break is affected more by the viewing angle (for {theta}{sub obs} {<=} {theta}{sub 0}) than by the slope of the external density profile (for 0 {<=} k {<=} 2). Steeper density profiles (i.e., increasing k values) are found to produce more gradual jet breaks while larger viewing angles cause smoother and later appearing jet breaks. The counterjet becomes visible as it becomes sub-relativistic, and for k = 0 this results

  6. Data for absorbed dose calculations for external sources and for emitters within the body

    International Nuclear Information System (INIS)

    Hep, J.; Valenta, V.

    1976-01-01

    Tables give data for the calculation of absorbed doses from radioactivity sources accumulated in individual body organs. The tables are arranged in such manner that the gamma energy (J) absorbed in 1 kg of target organ (19 organs and total body) are given for 18 source organs (16 different organs, total doby and surrounding air) resulting from 1 decay event, this for more than 250 radioisotopes evenly distributed in the source organ (1 J/kg=100 rad). Also given are the energies of alpha and beta radiations related to one decay. In tables having the surrounding air as the source it is assumed that the intensity of the external source is 1 decay per 1 m 3 of surrounding air which is constant in the entire half-space. The tables are only elaborated for radioisotopes with a half-life of more than 1 min. (B.S.)

  7. Broadband integrated mid infrared light sources as enabling technology for point of care mid-infrared spectroscopy

    Science.gov (United States)

    2017-08-20

    AFRL-AFOSR-JP-TR-2017-0061 Broadband integrated mid-infrared light sources as enabling technology for point-of-care mid- infrared spectroscopy Alex...mid-infrared light sources as enabling technology for point-of-care mid-infrared spectroscopy 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-16-1-4037...Broadband integrated mid-infrared light sources as enabling technology for point-of-care mid- infrared spectroscopy ” Date: 16th August 2017 Name

  8. Design of TIR collimating lens for ordinary differential equation of extended light source

    Science.gov (United States)

    Zhan, Qianjing; Liu, Xiaoqin; Hou, Zaihong; Wu, Yi

    2017-10-01

    The source of LED has been widely used in our daily life. The intensity angle distribution of single LED is lambert distribution, which does not satisfy the requirement of people. Therefore, we need to distribute light and change the LED's intensity angle distribution. The most commonly method to change its intensity angle distribution is the free surface. Generally, using ordinary differential equations to calculate free surface can only be applied in a point source, but it will lead to a big error for the expand light. This paper proposes a LED collimating lens based on the ordinary differential equation, combined with the LED's light distribution curve, and adopt the method of calculating the center gravity of the extended light to get the normal vector. According to the law of Snell, the ordinary differential equations are constructed. Using the runge-kutta method for solution of ordinary differential equation solution, the curve point coordinates are gotten. Meanwhile, the edge point data of lens are imported into the optical simulation software TracePro. Based on 1mm×1mm single lambert body for light conditions, The degrees of collimating light can be close to +/-3. Furthermore, the energy utilization rate is higher than 85%. In this paper, the point light source is used to calculate partial differential equation method and compared with the simulation of the lens, which improve the effect of 1 degree of collimation.

  9. FEL polarization control studies on Dalian coherent light source

    International Nuclear Information System (INIS)

    Zhang Tong; Deng Haixiao; Wang Dong; Zhao Zhentang; Zhang Weiqing; Wu Guorong; Dai Dongxu; Yang Xueming

    2013-01-01

    The polarization switch of a free-electron laser (FEL) is of great importance to the user scientific community. In this paper, we investigate the generation of controllable polarization FEL from two well-known approaches for Dalian coherent light source, i.e., crossed planar undulator and elliptical permanent undulator. In order to perform a fair comparative study, a one-dimensional time-dependent FEL code has been developed, in which the imperfection effects of an elliptical permanent undulator are taken into account. Comprehensive simulation results indicate that the residual beam energy chirp and the intrinsic FEL gain may contribute to the degradation of the polarization performance for the crossed planar undulator. The elliptical permanent undulator is not very sensitive to the undulator errors and beam imperfections. Meanwhile, with proper configurations of the main planar undulators and additional elliptical permanent undulator section, circular polarized FEL with pulse energy exceeding 100 μJ could be achieved at Dalian coherent light source. (authors)

  10. Electrodeless light source provided with radioactive material

    International Nuclear Information System (INIS)

    1979-01-01

    Radioactive materials are used to assist in starting a discharge in an electrodeless light source. The radioactive emissions predispose on the inner surface of the lamp envelope loosely bound charges which thereafter assist in initiating discharge. The radioactive material can be enclosed within the lamp envelope in gaseous or non-gaseous form. Preferred materials are krypton 85 and americium 241. In addition, the radioactive material can be dispersed in the lamp envelope material or can be a pellet imbedded in the envelope material. Finally, the radioactive material can be located in the termination fixture. Sources of alpha particles, beta particles, or gamma rays are suitable. Because charges accumulate with time on the inner surface of the lamp envelope, activity levels as low as 10 -8 curie are effective as starting aids. (Auth.)

  11. A simple method to prolong the service life of radioactive sources for external radiotherapy.

    Science.gov (United States)

    Xu, Yingjie; Tian, Yuan; Dai, Jianrong

    2014-07-08

    A radioactive source is usually replaced and disposed after being used for a certain amount of time (usually a half-life). In this study, a simple method is proposed to prolong its service life. Instead of replacing the used source with a new source of full activity, a new source of less activity is added in the source holder in front of the used one, so that the total activity of two sources is equal to the initial activity of the used source or even higher. Similarly, more sources can be added to the previous ones. Attenuation of front source(s) to the back source(s) was evaluated with exponential attenuation equation, and variation of source-focus distance (SFD) with inverse square law for Leksell 4C Gamma Knife, which served as an example of external radiotherapy units. When the number of front sources increased from 1 to 3, the relative air kerma decreased from 36.5% to 5.0%. Both the attenuation effect and SFD variation contributed to the decrease in air kerma, with the former being the major factor. If the height of the source can be decreased in some way, such as increasing the specific activity of sources, the sources can be used more efficiently. The method prolongs the service life of sources by several factors, and reduces the expense of source exchange and reclamation.

  12. [The Performance Analysis for Lighting Sources in Highway Tunnel Based on Visual Function].

    Science.gov (United States)

    Yang, Yong; Han, Wen-yuan; Yan, Ming; Jiang, Hai-feng; Zhu, Li-wei

    2015-10-01

    Under the condition of mesopic vision, the spectral luminous efficiency function is shown as a series of curves. Its peak wavelength and intensity are affected by light spectrum, background brightness and other aspects. The impact of light source to lighting visibility could not be carried out via a single optical parametric characterization. The reaction time of visual cognition is regard as evaluating indexes in this experiment. Under the condition of different speed and luminous environment, testing visual cognition based on vision function method. The light sources include high pressure sodium, electrodeless fluorescent lamp and white LED with three kinds of color temperature (the range of color temperature is from 1 958 to 5 537 K). The background brightness value is used for basic section of highway tunnel illumination and general outdoor illumination, its range is between 1 and 5 cd x m(-)2. All values are in the scope of mesopic vision. Test results show that: under the same condition of speed and luminance, the reaction time of visual cognition that corresponding to high color temperature of light source is shorter than it corresponding to low color temperature; the reaction time corresponding to visual target in high speed is shorter than it in low speed. At the end moment, however, the visual angle of target in observer's visual field that corresponding to low speed was larger than it corresponding to high speed. Based on MOVE model, calculating the equivalent luminance of human mesopic vision, which is on condition of different emission spectrum and background brightness that formed by test lighting sources. Compared with photopic vision result, the standard deviation (CV) of time-reaction curve corresponding to equivalent brightness of mesopic vision is smaller. Under the condition of mesopic vision, the discrepancy between equivalent brightness of different lighting source and photopic vision, that is one of the main reasons for causing the

  13. The new Chalk River AMS ion source, sample changer and external sample magazine

    International Nuclear Information System (INIS)

    Koslowsky, V.T.; Bray, N.; Imahori, Y.; Andrews, H.R.; Davies, W.G.

    1997-01-01

    A new sample magazine, sample changer and ion source have been developed and are in routine use at Chalk River. The system features a readily accessible 40-sample magazine at ground potential that is external to the ion source and high-voltage cage. The samples are held in an inert atmosphere and can be individually examined or removed; they can be exchanged en masse as a complete magazine concurrent with an AMS measurement. On-line sample changing is done with a pneumatic rabbit transfer system employing two stages of differential pumping. At Chalk River this is routinely performed across a 200 kV potential. Sample positioning is precise, and hundreds of 36 Cl and 129 I samples have been measured over a period of several days without interruption or alteration of ion source operating conditions. (author)

  14. Australian synchrotron light source - (boomerang)

    International Nuclear Information System (INIS)

    Boldeman, J.

    2001-01-01

    The Australian National Synchrotron Light Source - (Boomerang) is to be installed at the Monash University in Victoria. This report provides some background to the proposed facility and discusses aspects of a prospective design. Recently, significant effort was devoted to refining the in principle design and a lattice providing an emittance od 18 nm rad was obtained with a distributed dispersion in the straight section of 0.29m. Exhaustive studies have been made of the economic benefits that would accrue to Australia to Australia following the installation of this facility. This design is a refinement of the design concept presented to the SRI -2000, Berlin (Boldeman, Einfeld et al), to the meeting of the 4th Asian Forum and the Preliminary Design Study presented to the Australian Synchrotron Research Program

  15. Long-term storage life of light source modules by temperature cycling accelerated life test

    International Nuclear Information System (INIS)

    Sun Ningning; Tan Manqing; Li Ping; Jiao Jian; Guo Xiaofeng; Guo Wentao

    2014-01-01

    Light source modules are the most crucial and fragile devices that affect the life and reliability of the interferometric fiber optic gyroscope (IFOG). While the light emitting chips were stable in most cases, the module packaging proved to be less satisfactory. In long-term storage or the working environment, the ambient temperature changes constantly and thus the packaging and coupling performance of light source modules are more likely to degrade slowly due to different materials with different coefficients of thermal expansion in the bonding interface. A constant temperature accelerated life test cannot evaluate the impact of temperature variation on the performance of a module package, so the temperature cycling accelerated life test was studied. The main failure mechanism affecting light source modules is package failure due to solder fatigue failure including a fiber coupling shift, loss of cooling efficiency and thermal resistor degradation, so the Norris-Landzberg model was used to model solder fatigue life and determine the activation energy related to solder fatigue failure mechanism. By analyzing the test data, activation energy was determined and then the mean life of light source modules in different storage environments with a continuously changing temperature was simulated, which has provided direct reference data for the storage life prediction of IFOG. (semiconductor devices)

  16. Photoionization of multiply charged ions at the advanced light source

    International Nuclear Information System (INIS)

    Schlachter, A.S.; Kilcoyne, A.L.D.; Aguilar, A.; Gharaibeh, M.F.; Emmons, E.D.; Scully, S.W.J.; Phaneuf, R.A.; Muller, A.; Schippers, S.; Alvarez, I.; Cisneros, C.; Hinojosa, G.; McLaughlin, B.M.

    2004-01-01

    Photoionization of multiply charged ions is studied using the merged-beams technique at the Advanced Light Source. Absolute photoionization cross sections have been measured for a variety of ions along both isoelectronic and isonuclear sequences

  17. SETI via Leakage from Light Sails in Exoplanetary Systems

    OpenAIRE

    Guillochon, James F.; Loeb, Abraham

    2015-01-01

    The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft's own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of ...

  18. Human Sound Externalization in Reverberant Environments

    DEFF Research Database (Denmark)

    Catic, Jasmina

    In everyday environments, listeners perceive sound sources as externalized. In listening conditions where the spatial cues that are relevant for externalization are not represented correctly, such as when listening through headphones or hearing aids, a degraded perception of externalization may...... occur. In this thesis, the spatial cues that arise from a combined effect of filtering due to the head, torso, and pinna and the acoustic environment were analysed and the impact of such cues for the perception of externalization in different frequency regions was investigated. Distant sound sources...... were simulated via headphones using individualized binaural room impulse responses (BRIRs). An investigation of the influence of spectral content of a sound source on externalization showed that effective externalization cues are present across the entire frequency range. The fluctuation of interaural...

  19. The Importance of External Support in the Adoption of Open Source Server Software

    Science.gov (United States)

    Ven, Kris; Verelst, Jan

    IT managers seem to be hesitant to adopt OSS in the absence of professional support. Previous qualitative studies have indeed suggested that the availability of external support is important for the adoption of OSS. Therefore, we feel it is interesting to gain more insight into the role of external support in the adoption process. To this end, we performed a web survey involving 95 Belgian organizations. Our data suggests a balanced picture. As expected, our results show that the majority of organizations in our sample rely on commercial support such as vendor or third party support. Even organizations that have deployed OSS to a large extent—and that are therefore likely to have some experience and familiarity with OSS—rely on commercial support. Nevertheless, a considerable proportion of organizations indicated not to rely on commercial support, which suggests that internal expertise can be sufficient for successful adoption. Finally, and most surprisingly, we have found that the OSS community is used by a large proportion of organizations. This indicates that the OSS community is a valuable source of external support for organizations. Nevertheless, it appears that it is primarily used by organizations with a rather strong background in IT.

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

    Science.gov (United States)

    2016-11-29

    AFRL-AFOSR-VA-TR-2016-0365 Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source Jerome Moloney...SUBTITLE "Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source 5a. CONTRACT NUMBER FA9550-15-1-0272 5b...Wavelength Electromagnetic Light Bullets Generated by a 10 µm CO2 Ultrashort Pulsed Source Grant/Contract Number AFOSR assigned control number. It must

  1. Industrial residues as an external carbon source in denitrification; Industrielle Reststoffe als externe Kohlenstoffquelle fuer die Denitrifikation

    Energy Technology Data Exchange (ETDEWEB)

    Schories, G. [TECON GmbH, Clausthal-Zellerfeld (Germany); Geissen, S.U.; Vogelpohl, A. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Thermische Verfahrenstechnik

    1999-07-01

    Biological waste water treatment requires biologically readily degradable carbon in order to permit elimination of as much nitrogen as possible. Often now this type of carbon is no longer present in waste water in an appropriate quantity, so that external carbon must be added. Apart from industrially fabricated substrates, the use of industrial residues and waste products as well as of partial waste water streams with a high organic pollutant load is lately being considered for cost reasons. But this is not altogether harmless. Those partial streams may contain substances that inhibit denitrification, impose an additional burden on subsequent cleaning stages or may even pass them unmodified, so that they are emitted into the environment and pose an ecological hazard potential. Hence, industrial residual products need to be specifically selected for use as an external carbon source in denitrification. A suitable strategy is described and demonstrated by means of different examples. (orig.) [German] In der biologischen Abwasserbehandlung ist fuer eine weitestgehende Stickstoffelimination oftmals biologisch gut abbaubarer Kohlenstoff im Abwasser nicht (mehr) in ausreichendem Masse vorhanden. Dann ist die Zugabe einer sog. externen Kohlenstoffquelle erforderlich. Neben industriell hergestellten Substraten wird in letzter Zeit aus Kostengruenden vielfach der Einsatz industrieller Rest- und Abfallstoffe sowie organisch hochbelasteter Abwasserteilstroeme erwogen. Dies ist jedoch nicht unproblematisch, da in diesen Stoffstroemen auch Substanzen enthalten sein koennen, die die Denitrifikation hemmen, nachfolgende Reinigungsstufen zusaetzlich belasten oder diese sogar unveraendert passsieren, dadurch in die Umwelt emittiert werden und damit moeglicherweise aus oekologischer Sicht ein Gefahrenpotential darstellen koennen. Es muss also eine besondere Auswahl der Pruefung industrieller Reststoffe im Hinblick auf den Einsatz als externe Kohlenstoffquelle in der Denitrifikation

  2. Operating experience with existing light sources

    International Nuclear Information System (INIS)

    Barton, M.Q.

    1985-01-01

    It is instructive to consider what an explosive growth there has been in the development of light sources using synchrotron radiation. This is well illustrated by the list of facilities given in Table I. In many cases, synchrotron light facilities have been obtained by tacking on parasitic beam lines to rings that were built for high energy physics. Of the twenty-three facilities in this table, however, eleven were built explicitely for this synchrotron radiation. Another seven have by now been converted for use as dedicated facilities leaving only five that share time with high energy physics. These five parasitically operated facilities are still among our best sources of hard x-rays, however, and their importance to the fields of science where these x-rays are needed must be emphasized. While the number of facilities in this table is impressive, it is even more impressive to add up the total number of user beam lines. Most of these rings are absolutely surrounded by beam lines and finding real estate on the experimental floor of one of these facilities for adding a new experiment looks about as practical as adding a farm in the middle of Manhattan. Nonetheless, the managers of these rings seem to have an attitude of ''always room for one more'' and new experimental beam lines do appear. This situation is necessary because the demand for beam time has exploded at an even faster rate than the development of the facilities. The field is not only growing, it can be expected to continue to grow for some time. Some of the explicit plans for future development will be discussed in the companion paper by Lee Teng

  3. The Advanced Light Source Upgrade

    International Nuclear Information System (INIS)

    Chemla, Daniel S.; Feinberg, Benjamin; Hussain, Zahid; Krebs, Gary F.; Padmore, Howard A.; Robin, David S.; Robinson, Arthur L.; Smith, Neville V.

    2003-01-01

    The ALS, a third-generation synchrotron light source at Berkeley Lab, has been operating for almost a decade and is generating forefront science by exploiting the high brightness of a third-generation source in three areas: (1) high resolving power for spectroscopy; (2) high spatial resolution for microscopy and spectromicroscopy; and (3) high coherence for experiments such as speckle. However, the ALS was one of the first third-generation machines to be designed, and accelerator and insertion-device technology have significantly changed since its conception. As a result, its performance will inevitably be outstripped by newer, more advanced sources. To remain competitive and then set a new standard, the performance of the ALS, in particular its brightness, must be enhanced. Substantial improvements in brightness and current have always been feasible in principle, but they incur the penalty of a much reduced lifetime, which is totally unacceptable to our users. Significant brightness improvements can be realized in the core soft x-ray region by going to top-off operation, where injection would be quasi-continuous and the lifetime objections disappear. In top-off mode with higher average current, a reduced vertical emittance and beta function, and small-gap permanent-magnet or superconducting insertion devices, one to two orders of magnitude improvement in brightness can be had in the soft x-ray range. These improvements also extend the high energy range of the undulator radiation beyond the current limit of 2000 eV. Descriptions of the upgrade and the important new science achievable are presented

  4. Advanced Light Source control system

    International Nuclear Information System (INIS)

    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

  5. 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...

  6. Advanced light ion source extraction system for a new electron cyclotron resonance ion source geometry at Saclay

    Energy Technology Data Exchange (ETDEWEB)

    Delferriere, O.; Gobin, R.; Harrault, F.; Nyckees, S.; Sauce, Y.; Tuske, O. [Commissariat a l' Energie Atomique, CEA/Saclay, DSM/IRFU, 91191 Gif/Yvette (France)

    2012-02-15

    One of the main goal of intense light ion injector projects such as IPHI, IFMIF, or SPIRAL2, is to produce high current beams while keeping transverse emittance as low as possible. To prevent emittance growth induced in a dual solenoid low energy transfer line, its length has to be minimized. This can be performed with the advanced light ion source extraction system concept that we are developing: a new ECR 2.45 GHz type ion source based on the use of an additional low energy beam transport (LEBT) short length solenoid close to the extraction aperture to create the resonance in the plasma chamber. The geometry of the source has been considerably modified to allow easy maintenance of each component and to save space in front of the extraction. The source aims to be very flexible and to be able to extract high current ion beams at energy up to 100 kV. A specific experimental setup for this source is under installation on the BETSI test bench, to compare its performances with sources developed up to now in the laboratory, such as SILHI, IFMIF, or SPIRAL2 ECR sources. This original extraction source concept is presented, as well as electromagnetic simulations with OPERA-2D code. Ion beam extraction in space charge compensation regime with AXCEL, and beam dynamics simulation with SOLMAXP codes show the beam quality improvement at the end of the LEBT.

  7. Optical Characteristics of a Multichannel Hybrid Integrated Light Source for Ultra-High-Bandwidth Optical Interconnections

    Directory of Open Access Journals (Sweden)

    Takanori Shimizu

    2015-11-01

    Full Text Available The optical characteristics of a multi-channel hybrid integrated light source were described for an optical interconnection with a bandwidth of over 10 Tbit/s. The power uniformity of the relative intensity of a 1000-channel light source was shown, and the minimum standard deviation s of the optical power of the 200 output ports at each 25-channel laser diode (LD array was estimated to be 0.49 dB. This hybrid integrated light source is expected to be easily adaptable to a photonics-electronics convergence system for ultra-high-bandwidth interchip interconnections.

  8. Theoretical analysis of multiple quantum-well, slow-light devices under applied external fields using a fully analytical model in fractional dimension

    Energy Technology Data Exchange (ETDEWEB)

    Kohandani, R; Kaatuzian, H [Photonics Research Laboratory, Electrical Engineering Department, AmirKabir University of Technology, Hafez Ave., Tehran (Iran, Islamic Republic of)

    2015-01-31

    We report a theoretical study of optical properties of AlGaAs/GaAs multiple quantum-well (MQW), slow-light devices based on excitonic population oscillations under applied external magnetic and electric fields using an analytical model for complex dielectric constant of Wannier excitons in fractional dimension. The results are shown for quantum wells (QWs) of different width. The significant characteristics of the exciton in QWs such as exciton energy and exciton oscillator strength (EOS) can be varied by application of external magnetic and electric fields. It is found that a higher bandwidth and an appropriate slow-down factor (SDF) can be achieved by changing the QW width during the fabrication process and by applying magnetic and electric fields during device functioning, respectively. It is shown that a SDF of 10{sup 5} is obtained at best. (slowing of light)

  9. 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.

  10. What makes Chinese firms to choose international external technology sources? An inquiry on internationalization, innovation and institutions

    DEFF Research Database (Denmark)

    Li-Ying, Jason; Wang, Yuandi

    2013-01-01

    . However, we have also witnessed an emerging trend of external acquisition of technology by EMFs firms in both international and domestic markets. Why some EMFs are active in sourcing both domestic and international technologies instead of being significantly in favour of foreign technologies from...... framework. Based on a unique sample of 389 Chinese firms on their inward technology licensing activities through an observation period from 2000 to 2005, it is found that (1) firms’ international market orientation; (2) firm’s technological capability; (3) regional innovation capability; and (4......External technology sourcing from developed countries has been one of the most important vehicles by which emerging market firms (EMFs) sustain competiveness. Foreign advanced technologies offer EMFs opportunities to gain access to state-of-the-art technologies and upgrade their competitiveness...

  11. 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...

  12. Crystal scintillators for use in check-light source for thermoluminescent systems

    Science.gov (United States)

    Nagpal, J. S.; Sabharwal, S. C.; Chougaonkar, M. P.; Godbole, S. V.

    1999-08-01

    Beta ( 63Ni, Emax 0.063 MeV) excited radioluminescence of indigenously grown crystal scintillators CsI(Tl), Bi 4Ge 3O 12 and CdWO 4 has been studied for its use in check-light source needed for thermoluminescence systems. Temperature coefficient of the light output over 298-323 K and the beta-induced TL of the scintillators over 298-553 K are reported.

  13. Luminopsins integrate opto- and chemogenetics by using physical and biological light sources for opsin activation

    Science.gov (United States)

    Berglund, Ken; Clissold, Kara; Li, Haofang E.; Wen, Lei; Park, Sung Young; Gleixner, Jan; Klein, Marguerita E.; Lu, Dongye; Barter, Joseph W.; Rossi, Mark A.; Augustine, George J.; Yin, Henry H.; Hochgeschwender, Ute

    2016-01-01

    Luminopsins are fusion proteins of luciferase and opsin that allow interrogation of neuronal circuits at different temporal and spatial resolutions by choosing either extrinsic physical or intrinsic biological light for its activation. Building on previous development of fusions of wild-type Gaussia luciferase with channelrhodopsin, here we expanded the utility of luminopsins by fusing bright Gaussia luciferase variants with either channelrhodopsin to excite neurons (luminescent opsin, LMO) or a proton pump to inhibit neurons (inhibitory LMO, iLMO). These improved LMOs could reliably activate or silence neurons in vitro and in vivo. Expression of the improved LMO in hippocampal circuits not only enabled mapping of synaptic activation of CA1 neurons with fine spatiotemporal resolution but also could drive rhythmic circuit excitation over a large spatiotemporal scale. Furthermore, virus-mediated expression of either LMO or iLMO in the substantia nigra in vivo produced not only the expected bidirectional control of single unit activity but also opposing effects on circling behavior in response to systemic injection of a luciferase substrate. Thus, although preserving the ability to be activated by external light sources, LMOs expand the use of optogenetics by making the same opsins accessible to noninvasive, chemogenetic control, thereby allowing the same probe to manipulate neuronal activity over a range of spatial and temporal scales. PMID:26733686

  14. Research by industry at the National Synchrotron Light Source

    International Nuclear Information System (INIS)

    1995-05-01

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

  15. Time-dependent scattering of incident light of various wavelengths in ferrofluids under external magnetic field

    Science.gov (United States)

    Jin, Jingyu; Song, Dongxing; Geng, Jiafeng; Jing, Dengwei

    2018-02-01

    Ferrofluids can exhibit the anisotropic thermodynamic properties under magnetic fields. The dynamic optical properties of ferrofluids in the presence of magnetic fields are of particular interest due to their potential application as various optical devices. Although time-dependent light scattering by ferrofluids have been extensively studied, the effect of wavelength of incident light have been rarely considered. Here, for the first time, we investigated both the time- and wavelength-dependent light scattering in water based ferrofluids containing Fe3O4 nanoparticles under an external magnetic field. The field-induced response behavior of the prepared ferrofluid samples was determined and verified first by thermal conductivity measurement and numerical simulation. Double-beam UV-Vis spectrophotometer was employed to record the temporal evolution of transmitted intensity of incident light of various wavelengths passing through the ferrofluid sample and propagating parallel to the applied field. As expected, the light intensity decreases to a certain value right after the field is turned on due to the thermal fluctuation induced disorder inside the flexible particle chains. Then the light intensity further decreases with time until the appearance of a minimum at time τ0 followed by an inversed increase before finally reaches equilibrium at a particular time. More importantly, the characteristic inversion time τ0 was found to follow a power law increase with the wavelength of incident light (τ0 ∼ λα, where α = 2.07). A quantitative explanation for the wavelength dependence of characteristic time was proposed based on the finite-difference time-domain (FDTD) method. The simulation results are in good agreement with our experimental observations. The time-dependent light scattering in ferrofluids under different incident wavelengths was rationalized by considering both the coarsening process of the particle chains and the occurrence of resonance within the

  16. Characterization of tunable light source by optical parametric oscillator for high resolution spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J. W. [Ewha Womens Univ., Seoul (Korea); Rhee, B. G. [Sejong Univ., Seoul (Korea); Park, S. W. [Yonsei Univ., Seoul (Korea); Noh, J. W. [Inha Univ., Incheon (Korea)

    1998-04-01

    A tunable light source is developed by the optical parametric oscillator, which is very useful for a high resolution spectroscopy. The electronic structure of molecules and atoms can be examined by a proper coherent light source. Optical parametric oscillator provides light sources stable and widely tunable. In this work, the characteristics of the parametric optical generation are examined in the LiNbO{sub 3}. The theoretical analysis as well as the experimental measurement is performed. The pump laser is a second harmonic of Nd:YAG laser, and the parametric gain is measured. The characteristics of singly resonant oscillator and doubly resonant oscillator is studied as a function of temperature. It is found that 1mole% MgO:LiNbO{sub 3} crystal provides the tunability from 0.6{mu}m to 3.0{mu}m wavelength. Both the critical and noncritical phase matching are studied. The optical damage occurring in a congruent LiNbO{sub 3} crystal was not observed in 1mole% MgO:LiNbO{sub 3} crystal, opening a possibility for a high power optical parametric oscillation generation. The current work can be extended to an experiment employing the fundamental Nd:YAG as pump to provide a coherent light source for the study of molecular vibrations. 28 refs., 14 figs., 3 tabs. (Author)

  17. Impact of various lighting source (incandescent, fluorescent, metal halide and high pressure sodium) on the production performance of chicken broilers

    International Nuclear Information System (INIS)

    Guffar, A.; Rahman, K.U.; Siddique, M.; Ahmad, F.

    2009-01-01

    Light is an important aspect of an animal's environment. Avian as well as mammalian species respond to light energy in a variety of ways. Recent research has indicated that light source may affect body weight, immune response, livability and health status. Broiler behavior is strongly affected by light sources. So the present project was designed to study the effect of light sources on the production performance of broilers. For this purpose, 500 day-old broilers purchased from the local market were reared for three days (adaptation period) in one group. Then these were randomly divided into five experimental groups each comprising of 100 birds. Group A was given 25 incandescent light (INC), Group B was given fluorescent light (FC), Group C was given metal halide light (MH), Group D was given high pressure sodium light (HPS) and Group E was given no light source (control). Performance trial in terms of measurement of weekly body weight, weekly feed consumption, feed conversion ratio (FCR), daily water consumption and mortality were checked. Among various lighting sources, MH proved the best light source regarding main parameters of production performance. (author)

  18. External costs of energy - do the answers match the questions? Looking back at 10 years of ExternE

    International Nuclear Information System (INIS)

    Krewitt, W.

    2002-01-01

    While the claim for 'getting prices right' is quite popular in conceptual policy papers, the implementation of appropriate internalisation strategies is still hampered by a lack of reliable external cost data. Great expectations were set into the ExternE project, a major research programme launched by the European Commission at the beginning of the 1990s to provide a scientific basis for the quantification of energy related externalities and to give guidance supporting the design of internalisation measures. After more than a decade of research, the ExternE label became a well recognised standard source for external cost data. Looking back into the ExternE history, the paper pursues how emerging new scientific insights and changing background assumptions affected external cost estimates and related recommendations to policy over time. Based on ExternE results, the usefulness and inherent limitations of external cost estimates for impact categories like climate change or nuclear waste disposal is discussed. The paper also gives examples on how external costs in spite of remaining uncertainties are successfully used to support environmental policy. (Author)

  19. Eternal triangle: the interaction of light source, electrical control gear, and optics

    Science.gov (United States)

    S'heeren, Griet

    1998-04-01

    In this particular 'affair' the participants are less than human but have individual personalities they bring to their relationship with each other. High pressure metal halide lamps such as BriteArc lamps have the highest luminance and radiance of all continuously operating practical light source. Since these lamps have short arcs and are available in power ratings from about 30W to 30kW they have found applications with various optical systems. Besides the lamps, such systems include an electrical control device and an optical system. To fulfil the user's requirements for a specific application, it is not only important to choose the right lamp, but crucial to achieve a harmonious marriage between the light source, electrical control device and the optics. To run a high pressure discharge lamp an ignitor/ballast system is essential This stabilizes the lamp parameters. The chemical components inside the lamp determine the lamp voltage and the gear determines, via the current, the lamp power. These are directly related in the luminance and color temperature of the emitted light. Therefore lamp performance and effective life are dependent on the ignitor, control gear and lamp combination. Since the lamp emits radiation in all directions, collection of the light from a lamp can be improved by using reflectors to deliver the light into a lens system. Since lamps with short arc gaps approach a point source they appear ideal for optical system applications. The shape of the reflector and the focusing of the lamp determine which part of the light is collected out of the light-arc. In the case of an LCD projector, the final light output also depends on the transmission characteristics of the LCD panels. Their nonlinearity causes the color of the emitted light to be different from the lamp color. All these parameters have to be optimized to obtain the highest performance. This leads to the conclusion that a carefully matched combination of lamp, ignitor/ballast and optics

  20. Magnet costs for the Advanced Light Source

    International Nuclear Information System (INIS)

    Tanabe, J.; Krupnick, J.; Hoyer, E.; Paterson, A.

    1993-05-01

    The Advanced Light Source (ALS) accelerator is now completed. The numerous conventional magnets required for the booster ring, the storage ring and the low and high energy transfer lines were installed during the last two years. This paper summarizes the various costs associated with the quantity fabrication of selected magnet families. These costs include the costs of prototypes, tooling, coil and core fabrication, assembly and magnetic measurements. Brief descriptions of the magnets and specialized requirements for magnetic measurements are included in order to associate the costs with the relative complexities of the various magnet systems

  1. 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...... 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...

  2. Sources of light-absorbing aerosol in arctic snow and their seasonal variation

    Directory of Open Access Journals (Sweden)

    Dean A. Hegg

    2010-11-01

    Full Text Available Two data sets consisting of measurements of light absorbing aerosols (LAA in arctic snow together with suites of other corresponding chemical constituents are presented; the first from Siberia, Greenland and near the North Pole obtained in 2008, and the second from the Canadian arctic obtained in 2009. A preliminary differentiation of the LAA into black carbon (BC and non-BC LAA is done. Source attribution of the light absorbing aerosols was done using a positive matrix factorization (PMF model. Four sources were found for each data set (crop and grass burning, boreal biomass burning, pollution and marine. For both data sets, the crops and grass biomass burning was the main source of both LAA species, suggesting the non-BC LAA was brown carbon. Depth profiles at most of the sites allowed assessment of the seasonal variation in the source strengths. The biomass burning sources dominated in the spring but pollution played a more significant (though rarely dominant role in the fall, winter and, for Greenland, summer. The PMF analysis is consistent with trajectory analysis and satellite fire maps.

  3. Phase 2 safety analysis report: National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Stefan, P.

    1989-06-01

    The Phase II program was established in order to provide additional space for experiments, and also staging and equipment storage areas. It also provides additional office space and new types of advanced instrumentation for users. This document will deal with the new safety issues resulting from this extensive expansion program, and should be used as a supplement to BNL Report No. 51584 ''National Synchrotron Light Source Safety Analysis Report,'' July 1982 (hereafter referred to as the Phase I SAR). The initial NSLS facility is described in the Phase I SAR. It comprises two electron storage rings, an injection system common to both, experimental beam lines and equipment, and office and support areas, all of which are housed in a 74,000 sq. ft. building. The X-ray Ring provides for 28 primary beam ports and the VUV Ring, 16. Each port is capable of division into 2 or 3 separate beam lines. All ports receive their synchrotron light from conventional bending magnet sources, the magnets being part of the storage ring lattice. 4 refs

  4. ECR ion source for variable energy cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Bose, D K; Taki, G S; Nabhiraj, P Y; Pal, G; Dasgupta, B; Mallik, C; Das, S K; Bandopadhaya, D K; Bhandari, R K [Variable Energy Cyclotron Centre, Calcutta (India)

    1995-09-01

    Some performance characteristics of 6.4 GHz two stage ECR ion source which was under development at this centre is presented. The present ion source will facilitate acceleration of light heavy ions with the existing k=130 variable energy cyclotron. Multiply charged heavy ion (MCHI) beam from the source will also be utilized for atomic physics studies. Oxygen beam has already been used for ion implantation studies. The external injection system under development is nearing completion. Heavy ion beam from cyclotron is expected by end of 1995. (author).

  5. Characterization of a Low-Cost Optical Flow Sensor When Using an External Laser as a Direct Illumination Source

    Directory of Open Access Journals (Sweden)

    Jordi Palacín

    2011-12-01

    Full Text Available In this paper, a low cost optical flow sensor is combined with an external laser device to measure surface displacements and mechanical oscillations. The measurement system is based on applying coherent light to a diffuser surface and using an optical flow sensor to analyze the reflected and transferred light to estimate the displacement of the surface or the laser spot. This work is focused on the characterization of this measurement system, which can have the optical flow sensor placed at different angles and distances from the diffuser surface. The results have shown that the displacement of the diffuser surface is badly estimated when the optical mouse sensor is placed in front of the diffuser surface (angular orientation >150° while the highest sensitivity is obtained when the sensor is located behind the diffuser surface and on the axis of the laser source (angular orientation 0°. In this case, the coefficient of determination of the measured displacement, R2, was very high (>0.99 with a relative error of less than 1.29%. Increasing the distance between the surface and the sensor also increased the sensitivity which increases linearly, R2 = 0.99. Finally, this measurement setup was proposed to measure very low frequency mechanical oscillations applied to the laser device, up to 0.01 Hz in this work. The results have shown that increasing the distance between the surface and the optical flow sensor also increases the sensitivity and the measurement range.

  6. The IBM-5C stationary in source without an external magnetic field

    International Nuclear Information System (INIS)

    Kulygin, V.M.; Malakhov, N.P.; Panasenkov, A.A.; Pleshivtsev, N.V.; Romanov, V.I.; Semashko, N.N.; Seregin, V.S.; Chukhin, I.A.; Shmeleva, V.I.

    1982-01-01

    With the purpose of constructing efficient injectors of hydrogen fast atoms for plasma heating in magnetic traps problems arising in the course of creation of stationary high-current ion sources and specific methods of solution of these problems are considered. The design and characteristics of the YVM-50 stationary ion source without an external magnetic field intended for obtaining hydrogen ion beams with energy up to 40 keV, current 30 A and pulse duration over 2 sec. are described. Thermal regime of ion source direct heating cathode is considered. It is shown that the lanthanum hexaboride cathode at the temperature 1700 deg C ensures 30 A/cm 2 emission density radiating about 60 W/cm 2 . YBM-5c consists of a gas-discharge chamber (GDC) and ion-optical system (IOS). GDS is composed of a cathode unit, anode flange, casing, gas supply system, IOS consists of emission accelerating and earthed electrodes. At the discharge pulse duration less than 1 sec. current emission density attains 0,5 A/cm 2 which permits to extract from the ion source 30 A current beam. The ion source operation in complex with a high-voltage supply system has shown that one of the most important problems is reliability of high-voltage protection from break-downs and stability of modulators operation

  7. 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.

  8. Approaches in estimation of external cost for fuel cycles in the ExternE project

    International Nuclear Information System (INIS)

    Afanas'ev, A.A.; Maksimenko, B.N.

    1998-01-01

    The purposes, content and main results of studies realized within the frameworks of the International Project ExternE which is the first comprehensive attempt to develop general approach to estimation of external cost for different fuel cycles based on utilization of nuclear and fossil fuels, as well as on renewable power sources are discussed. The external cost of a fuel cycle is treated as social and environmental expenditures which are not taken into account by energy producers and consumers, i.e. these are expenditures not included into commercial cost nowadays. The conclusion on applicability of the approach suggested for estimation of population health hazards and environmental impacts connected with electric power generation growth (expressed in money or some other form) is made

  9. Silicon-photonics light source realized by III-V/Si grating-mirror laser

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2010-01-01

    waveguide are made in the Si layer of a silicon-on-insulator wafer by using Si-electronics-compatible processing. The HCG works as a highly-reflective mirror for vertical resonance and at the same time routes light to the in-plane output waveguide. Numerical simulations show superior performance compared...... to existing silicon light sources....

  10. External Knowledge Sourcing and Green Innovation Growth with Environmental and Energy Regulations: Evidence from Manufacturing in China

    Directory of Open Access Journals (Sweden)

    Jian Hou

    2017-02-01

    Full Text Available This paper adopts the slacks-based measure-directional distance function (SBM-DDF, 2009 method for deriving the “Green Innovation Growth” rates of 28 manufacturing industries in China. The results indicate that the overall level of green innovation growth in China’s manufacturing is relatively low, with a declining trend. The tradeoffs among energy, environment and economy are rather sharp, and the “Porter Effect (1995” (environmental regulation will promote green technology innovation is not currently realized quickly in manufacturing. These evaluations imply an unsustainable development model in China, with significant differences among industries. By using a dynamic panel threshold model and employing an industry-level panel dataset for 2008–2014, we show that external knowledge sourcing has a significant negative impact on green innovation growth but with different constraints on R&D levels among industries. With the strengthening of R&D levels, gradually surpassing “critical mass”, the negative role of external knowledge sourcing in driving this mechanism becomes smaller and smaller; it has a non-linear relationship with the “threshold effect”. Consequently, we provide insights into the relationship among energy consumption, environmental pollution and technology innovation, and show how the heterogeneity of the R&D threshold affects differences in external knowledge sourcing and green innovation growth. These insights lead to a better understanding of the driving force, realizing path and policy design for green innovation growth.

  11. Functional magnetic resonance imaging study of external source memory and its relation to cognitive insight in non-clinical subjects.

    Science.gov (United States)

    Buchy, Lisa; Hawco, Colin; Bodnar, Michael; Izadi, Sarah; Dell'Elce, Jennifer; Messina, Katrina; Lepage, Martin

    2014-09-01

    Previous research has linked cognitive insight (a measure of self-reflectiveness and self-certainty) in psychosis with neurocognitive and neuroanatomical disturbances in the fronto-hippocampal neural network. The authors' goal was to use functional magnetic resonance imaging (fMRI) to investigate the neural correlates of cognitive insight during an external source memory paradigm in non-clinical subjects. At encoding, 24 non-clinical subjects travelled through a virtual city where they came across 20 separate people, each paired with a unique object in a distinct location. fMRI data were then acquired while participants viewed images of the city, and completed source recognition memory judgments of where and with whom objects were seen, which is known to involve prefrontal cortex. Cognitive insight was assessed with the Beck Cognitive Insight Scale. External source memory was associated with neural activity in a widespread network consisting of frontal cortex, including ventrolateral prefrontal cortex (VLPFC), temporal and occipital cortices. Activation in VLPFC correlated with higher self-reflectiveness and activation in midbrain correlated with lower self-certainty during source memory attributions. Neither self-reflectiveness nor self-certainty significantly correlated with source memory accuracy. By means of virtual reality and in the context of an external source memory paradigm, the study identified a preliminary functional neural basis for cognitive insight in the VLPFC in healthy people that accords with our fronto-hippocampal theoretical model as well as recent neuroimaging data in people with psychosis. The results may facilitate the understanding of the role of neural mechanisms in psychotic disorders associated with cognitive insight distortions. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology.

  12. The national synchrotron light source and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Williams, G.P.

    1989-01-01

    We describe the National Synchrotron Light Source facility including its beamlines and operational characteristics. Research results on selected beamlines on the VUV ring which highlight new experimental capabilities are described since they are more relevant to the program at HESYRL. Examples chosen are spin-polarized photoemission, infra-red surface science, high resolution core level spectroscopy, X- Ray lithography, photoelectron/Auger coincidence spectroscopy and high electron momentum resolution surface studies. 7 refs., 3 figs., 3 tabs.

  13. Status of the National Synchrotron Light Source upgrade

    International Nuclear Information System (INIS)

    Culwick, B.B.; Smith, J.D.

    1985-01-01

    The demands for real-time control, data acquisition and display from accelerators of the National Synchrotron Light Source have exceeded the capabilities of the computer control system designed in 1978. In January 1985, a workshop on control systems was held at Brookhaven, one of the purposes of which was to provide impetus and design goals for an upgrade of the NSLS control system. The resulting design is described and its status reported

  14. Commissioning of the advanced light source dual-axis streak camera

    International Nuclear Information System (INIS)

    Hinkson, J.; Keller, R.; Byrd, J.

    1997-05-01

    A dual-axis camera, Hamamatsu model C5680, has been installed on the Advanced Light Source photon-diagnostics beam-line to investigate electron-beam parameters. During its commissioning process, the camera has been used to measure single-bunch length vs. current, relative bunch charge in adjacent RF buckets, and bunchphase stability. In this paper the authors describe the visible-light branch of the diagnostics beam-line, the streak-camera installation, and the timing electronics. They will show graphical results of beam measurements taken during a variety of accelerator conditions

  15. The ALS [Advanced Light Source]: A third generation light source

    International Nuclear Information System (INIS)

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

    1989-09-01

    The Advanced Light Source, a third-generation national synchrotron-radiation facility now under construction at the Lawrence Berkeley Laboratory, is scheduled to begin serving qualified users across a broad spectrum of research areas in April 1993. Based on a low- emittance electron storage ring optimized to operate at 1.5 GeV, the ALS will have 11 long straight sections available for insertion devices (undulators and wigglers). Undulators will generate high- brightness soft x-ray and ultraviolet (XUV) radiation; wigglers will extend the spectrum generated into the hard x-ray region, but at a lower brightness. Up to 48 bending-magnet ports will also be available. Engineering design has begun on a complement of three undulators with periods of 8.0, 5.0, and 3.9 cm that between them will cover the photon-energy range from 5.4 eV to 2.5 keV when the first, third, and fifth harmonics are used, as well as a wiggler with a critical energy of 3.1 keV. Undulator beam lines will be based on high-resolution spherical-grating monochromators. A Call for Proposals has been issued for those who wish to participate in the design, development, commissioning, and operation of the initial complement of ALS experimental facilities (insertion devices, beam lines, and experimental stations) as members of a participating research team. The deadline for receipt of proposals was August 15, 1989. Proposals are expected to reflect the Letters of Interest received from potential PRTs during the previous year. 6 refs., 4 figs., 5 tabs

  16. Crystal scintillators for use in check-light source for thermoluminescent systems

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, J.S.; Sabharwal, S.C.; Chougaonkar, M.P.; Godbole, S.V

    1999-08-11

    Beta ({sup 63}Ni, E{sub max} 0.063 MeV) excited radioluminescence of indigenously grown crystal scintillators CsI(Tl), Bi{sub 4}Ge{sub 3}O{sub 12} and CdWO{sub 4} has been studied for its use in check-light source needed for thermoluminescence systems. Temperature coefficient of the light output over 298-323 K and the beta-induced TL of the scintillators over 298-553 K are reported. (author)

  17. Measurement-device-independent quantum key distribution with correlated source-light-intensity errors

    Science.gov (United States)

    Jiang, Cong; Yu, Zong-Wen; Wang, Xiang-Bin

    2018-04-01

    We present an analysis for measurement-device-independent quantum key distribution with correlated source-light-intensity errors. Numerical results show that the results here can greatly improve the key rate especially with large intensity fluctuations and channel attenuation compared with prior results if the intensity fluctuations of different sources are correlated.

  18. Analysis of the external and internal quantum efficiency of multi-emitter, white organic light emitting diodes

    Science.gov (United States)

    Furno, Mauro; Rosenow, Thomas C.; Gather, Malte C.; Lüssem, Björn; Leo, Karl

    2012-10-01

    We report on a theoretical framework for the efficiency analysis of complex, multi-emitter organic light emitting diodes (OLEDs). The calculation approach makes use of electromagnetic modeling to quantify the overall OLED photon outcoupling efficiency and a phenomenological description for electrical and excitonic processes. From the comparison of optical modeling results and measurements of the total external quantum efficiency, we obtain reliable estimates of internal quantum yield. As application of the model, we analyze high-efficiency stacked white OLEDs and comment on the various efficiency loss channels present in the devices.

  19. Performance of the 2-D asynchronous OCDMA system with ASE light sources

    Science.gov (United States)

    Ni, Bin; Lehnert, James S.

    2005-09-01

    The wavelength-hopping/time-spreading scheme for optical code-division multiple-access (OCDMA), also known as the 2-D scheme, has been studied by many researchers for more than a decade. In all of previous analyses, the light sources were modeled as perfectly incoherent, which requires infinite bandwidth, and chip-synchrony was assumed for mathematical simplicity. Therefore, it is important to study how the system actually performs with true asynchrony and practical light sources. The amplified spontaneous emission (ASE) source is a desirable source for the incoherent OCDMA system because of its broad bandwidth, large power, and low cost. In this paper, each chip generated by the transmitter is a rectangular ASE pulse with a Gaussian-distributed electrical field. The coherence time is much smaller than the chip duration, but non-zero. Because of this partial coherence of the light source, beat noise will occur when multiple pulses are combined. In addition, interfering pulses may only partially overlap with the pulses from the desired user due to the asynchrony, which introduces more randomness into the decision statistic. Both factors are taken into account when the distribution of the decision statistic is derived mathematically. Simulations of the bit-error rate (BER) are performed, and the results show that the coherence time may be the major limiting factor on the system performance. For example, when the coherence time is only 1/100 of the chip duration, the BER is 1-4 orders of magnitude worse than that of the ideal case.

  20. Feasibility of ultraviolet-light-emitting diodes as an alternative light source for photocatalysis.

    Science.gov (United States)

    Levine, Lanfang H; Richards, Jeffrey T; Coutts, Janelle L; Soler, Robert; Maxik, Fred; Wheeler, Raymond M

    2011-09-01

    The objective of this study was to determine whether ultraviolet-light-emitting diodes (UV-LEDs) could serve as an efficient photon source for heterogeneous photocatalytic oxidation (PCO). An LED module consisting of 12 high-power UV-A (lambda max = 365 nm) LEDs was designed to be interchangeable with a UV-A fluorescent black light blue (BLB) lamp for a bench scale annular reactor packed with silica-titania composite (STC) pellets. Lighting and thermal properties of the module were characterized to assess its uniformity and total irradiance. A forward current (I(F)) of 100 mA delivered an average irradiance of 4.0 mW cm(-2) at a distance of 8 mm, 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 ethanol (50 ppm(v)) in a continuous-flow-through mode with 0.94 sec residence time. At the same average irradiance, the UV-A LED reactor resulted in a lower CO2 production rate (19.8 vs. 28.6 nmol L(-1) s(-1)), lower ethanol removal (80% vs. 91%), and lower mineralization efficiency (28% vs. 44%) than the UV-A BLB reactor. Ethanol mineralization was enhanced with the increase of the irradiance at the catalyst surface. This result suggests that reduced ethanol mineralization in the LED reactor relative to the BLB reactor at the same average irradiance could be attributed to the nonuniform irradiance over the photocatalyst, that is, a portion of the catalyst was exposed to less than the average irradiance. 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, our results also showed that the current UV-A LED module had the same wall plug efficiency (WPE) of 13% as that of the UV-A BLB, demonstrating that UV-A LEDs are a viable photon source both in terms of WPE and PCO efficiency.

  1. 49 CFR Appendix B to Part 564 - Information To Be Submitted for Long Life Replaceable Light Sources of Limited Definition

    Science.gov (United States)

    2010-10-01

    ...—Information To Be Submitted for Long Life Replaceable Light Sources of Limited Definition I. Filament or... Source that Operates With a Ballast and Rated Life of the Light Source/Ballast Combination. A. Maximum power (in watts). B. Luminous Flux (in lumens). C. Rated laboratory life of the light source/ballast...

  2. Excitation of anodized alumina films with a light source

    DEFF Research Database (Denmark)

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

    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....... 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......, with doping are discussed. Using the Kubelka-Munk model on the diffuse reflectance spectra of such films, the bandgap Eg of the oxide alloys can be determined....

  3. Automated tune measurements in the Advanced Light Source storage ring using a LabVIEW application

    International Nuclear Information System (INIS)

    Hinkson, J.A.; Chin, M.; Kim, C.H.; Nishimura, H.

    1994-06-01

    Horizontal and vertical betatron tunes and the synchrotron tune are measured frequently during storage ring commissioning. The measurements are tedious and subject to human errors. Automating this kind of repetitive measurement is underway using LabVIEW for Windows, a software application supplied by National Instruments Corporation, that provides acquisition, graphing, and analysis of data as well as instrument control through the General Purpose Interface Bus (GPIB). We have added LabVIEW access to the Advanced Light Source (ALS) data base and control system. LabVIEW is a fast and efficient tool for accelerator commissioning and beam physics studies. Hardware used to perform tune measurements include a tracking generator (or a white noise generator), strip line electrodes for external ''citation of the beam, button monitors, and a spectrum analyzer. All three tunes are displayed simultaneously on the spectrum analyzer. Our program automatically identifies three tunes by applying and analyzing small variations and reports the results. This routine can be encapsulated in other applications, for instance, in a chromaticity measurement and correction program

  4. Magnet power supplies for the Advanced Light Source

    International Nuclear Information System (INIS)

    Jackson, L.T.; Lutz, I.C.

    1989-03-01

    The Lawrence Berkeley Laboratory (LBL) is building an Advanced Light Source (ALS) to produce synchrotron radiation. An electron linear accelerator, and a booster synchrotron are used to accelerate the electron beam to 1.5 GeV to fill the storage ring. This paper describes the power supplies used for the magnets in the booster and the storage ring and the interface requirements for computer control and monitoring the power supplies and magnet currents. 1 ref., 3 figs., 2 tabs

  5. A preliminary study of synchrotron light sources for x-ray lithography

    International Nuclear Information System (INIS)

    Hoffmann, C.R.; Bigham, C.B.; Ebrahim, N.A.; Sawicki, J.A.; Taylor, T.

    1989-02-01

    A preliminary study of synchrotron light sources has been made, primarily oriented toward x-ray lithography. X-ray lithography is being pursued vigorously in several countries, with a goal of manufacturing high-density computer chips (0.25 μm feature sizes), and may attain commercial success in the next decade. Many other applications of soft x-rays appear worthy of investigation as well. The study group visited synchrotron radiation facilities and had discussions with members of the synchrotron radiation community, particularly Canadians. It concluded that accelerator technology for a conventional synchrotron light source appropriate for x-ray lithography is well established and is consistent with skills and experience at Chalk River Nuclear Laboratories. Compact superconducting systems are being developed also. Their technical requirements overlap with capabilities at Chalk River. (32 refs)

  6. Synchrotron applications of pixel and strip detectors at Diamond Light Source

    International Nuclear Information System (INIS)

    Marchal, J.; Tartoni, N.; Nave, C.

    2009-01-01

    A wide range of position-sensitive X-ray detectors have been commissioned on the synchrotron X-ray beamlines operating at the Diamond Light Source in UK. In addition to mature technologies such as image-plates, CCD-based detectors, multi-wire and micro-strip gas detectors, more recent detectors based on semiconductor pixel or strip sensors coupled to CMOS read-out chips are also in use for routine synchrotron X-ray diffraction and scattering experiments. The performance of several commercial and developmental pixel/strip detectors for synchrotron studies are discussed with emphasis on the image quality achieved with these devices. Examples of pixel or strip detector applications at Diamond Light Source as well as the status of the commissioning of these detectors on the beamlines are presented. Finally, priorities and ideas for future developments are discussed.

  7. Radioisotope-powered light sources

    International Nuclear Information System (INIS)

    Haff, K.W.; Case, F.N.; Tompkins, J.A.; Remini, W.C.

    1981-11-01

    Significant progress has been made in the past year to improve the geometry of 85 Kr-powered lights, making it possible to acquire the lights from a greater distance than was previously possible. This paper is an update and current status report on the work being done and the improvements made in both 85 Kr and tritium lights since the report made by F.N. Case and W.C. Remini at the November 1980 IES meeting

  8. Fusion reactor start-up without an external tritium source

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, S., E-mail: Shanliang.Zheng@ccfe.ac.uk; King, D.B.; Garzotti, L.; Surrey, E.; Todd, T.N.

    2016-02-15

    Highlights: • Investigated the feasibility (including plasma physics, neutronics and economics) of starting a fusion reactor from running pure D–D fusion reactor to gradually move towards the D–T operation. • Proposed building up tritium from making use of neutrons generated by D–D fusion reactions. • Studied plasma physics feasibility for pure D–D operation and provided consistent fusion power and neutron yield in the plasma with different mixture of deuterium and tritium. • Discussed the economics aspect for operating a pure D–D fusion reactor towards a full-power D–T fusion reactor. - Abstract: It has long been recognised that the shortage of external tritium sources for fusion reactors using D–T, the most promising fusion fuel, requires all such fusion power plants (FPP) to breed their own tritium. It is also recognised that the initial start-up of a fusion reactor will require several kilograms of tritium within a scenario in which radioactive decay, ITER and subsequent demonstrator reactors are expected to have consumed most of the known tritium stockpile. To circumvent this tritium fuel shortage and ultimately achieve steady-state operation for a FPP, it is essential to first accumulate sufficient tritium to compensate for loss due to decay and significant retention in the materials in order to start a new FPP. In this work, we propose to accumulate tritium starting from D–D fusion reactions, since D exists naturally in water, and to gradually build up the D–T plasma targeted in fusion reactor designs. There are two likely D–D fusion reaction channels, (1) D + D → T + p, and (2) D + D → He3 + n. The tritium can be generated via the reaction channel ‘(1)’ and the 2.45 MeV neutrons from ‘(2)’ react with lithium-6 in the breeding blanket to produce more tritium to be fed back into plasma fuel. Quantitative evaluations are conducted for two blanket concepts to assess the feasibility and suitability of this approach to FPP

  9. Status of the Advanced Light Source

    International Nuclear Information System (INIS)

    Marx, J.N.

    1990-06-01

    The Advanced Light Source (ALS), now under construction at the Lawrence Berkeley Laboratory, will be a national user facility for the production of high-brightness and partially coherent soft x-ray and ultraviolet synchrotron radiation. The ALS is based on a low-emittance electron storage ring optimized for operation at 1.5 GeV with insertion devices in 10 long straight sections and 24 premier bend-magnet ports. High-brightness photon beams, from less than 10 eV to more than 2 keV, will be produced by undulators, thereby providing many research opportunities in materials and surface science, biology, atomic physics and chemistry. Wigglers and bend magnets will provide high-flux, broad-band radiation at energies to 10 keV. 6 refs., 6 figs., 2 tabs

  10. The advanced light source control system

    International Nuclear Information System (INIS)

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

    1990-01-01

    The criteria for the design of a modern control system are discussed in the context of the special requirements for the control of the Advanced Light Source (ALS). This is followed by the description of the system being built, which has a number of special features. The emphasis has been placed on providing an extremely wide I/O and CPU bandwidth (greater than 120 Mbits/s and 1200 Mips, respectively) and on using commercially available hardware and software. The only major custom design item is the Intelligent Local Controller (ILC), of which about 600 will be used to interface to the hardware. The use of personal computers for the operator stations allows the use of a wealth of industrial standards for windows, languages and tools. (orig.)

  11. Phase II beam lines at the National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Thomlinson, W.

    1984-06-01

    The expansion of the National Synchrotron Light Source has been funded by the US Department of Energy. The Phase II program consists of both increased conventional facilities and six new beam lines. In this paper, an overview of the six beam lines which will be constructed during Phase II is presented. For five of the lines special radiation sources are necessary and the designs of four of the devices are complete. The relevant parameters of the insertion devices under construction and development are presented

  12. Radiation protection with consumer products containing gaseous tritium light sources

    International Nuclear Information System (INIS)

    Rahders, Erio; Haeusler, Uwe

    2017-01-01

    Consumer products containing gaseous tritium light sources (GTLS) were examined with respect to their radiological safety potential regarding leak tightness or accidents. The maximum tritium leakage rate of 2.7 Bq/d determined from experimental testing is well below the criterion for leak tightness of sealed radioactive sources in DIN 25426-4. In order to investigate the incorporation of tritium due to contact with consumer products, 2 scenarios were reviewed; the correct use of a tritium watch and the accident scenario with a keyring.

  13. Optimization of superconducting bending magnets for a 1.0 to 1.5 GeV compact light source

    International Nuclear Information System (INIS)

    Green, M.A.; Garren, A.A.

    1995-06-01

    Compact light sources are being proposed for protein crystallography, medical imaging, nano-machining and other areas of study that require intense sources of x rays at energies up to 35 keV. In order for a synchrotron light source to be attractive, its capital cost must, be kept low. The proposed compact light source has superconducting bending elements to bend the stored beam and produce the x rays. Additional focusing for the machine is provided by conventional quadrupoles. An important part of the cost optimization of a compact light source is the cost of the bending magnets. In the case of a machine with superconducting bending elements, the bending magnet system can represent close to half of the storage ring cost. The compact light source storage rings studied here have a range of stored electron energies from 1.0 to 1.5 GeV. For a number of reasons, it is desirable to keep the storage ring circumference below 30 meters. Cost optimization parameters include: (1) the number of superconducting bending elements in the ring, and (2) the central induction of the dipole. A machine design that features two superconducting dipoles in a single cryostat vacuum vessel is also discussed

  14. Practical investigation for road lighting using renewable energy sources "Sizing and modelling of solar/wind hybrid system for road lighting application"

    Directory of Open Access Journals (Sweden)

    Maged A. Abu Adma

    2017-12-01

    Full Text Available This study explains a design of a fully independent -off grid- hybrid solar and wind road lighting system according to geography and weather conditions recorded from the Egyptian National Research Institute of Astronomy and Geophysics.Presenting here the virtual simulation by using Matlab/Simulink & real-time implementation of road lighting system consists of 150 W photovoltaic cell, 420 W wind generator, 100 Ah acid gel battery and LED lighting luminar 30 W -12 VDC . Over three different stages; 1.Operating the system with PV only as power source, 2. Switching to Wind generator only configuration and 3.  Running the hybrid design with both PV & Wind power sources ; load characteristics and output real-time data will be recorded, evaluated ,compared  and validated against the virtual simulation generated by Matlab/Simulink model.The results of this research will be used to investigate the advantages of using a hybrid system to counteract the limitations of solar and wind as solo renewable energy sources due to adverse weather conditions ,the efficiency of the proposed system as an alternative for the current conventional road lighting poles as well as the accuracy of the virtual model data in order to be used for future adaptation of the model for different geographical locations.

  15. Design of Programmable LED Controller with a Variable Current Source for 3D Image Display

    Directory of Open Access Journals (Sweden)

    Kyung-Ryang Lee

    2014-12-01

    Full Text Available Conventional fluorescent light sources, as well as incandescent light sources are gradually being replaced by Light Emitting Diodes (LEDs for reducing power consumption in the image display area for multimedia application. An LED light source requires a controller with a low-power operation. In this paper, a low-power technique using adiabatic operation is applied for the implementation of LED controller with a stable constant-current, a low-power and low-heat function. From the simulation result, the power consumption of the proposed LED controller using adiabatic operation was reduced to about 87% in comparison with conventional operation with a constant VDD. The proposed circuit is expected to be an alternative LED controller which is sensitive to external conditions such as heat.

  16. Open innovation and external sources of innovation. An opportunity to fuel the R&D pipeline and enhance decision making?

    Science.gov (United States)

    Schuhmacher, Alexander; Gassmann, Oliver; McCracken, Nigel; Hinder, Markus

    2018-05-08

    Historically, research and development (R&D) in the pharmaceutical sector has predominantly been an in-house activity. To enable investments for game changing late-stage assets and to enable better and less costly go/no-go decisions, most companies have employed a fail early paradigm through the implementation of clinical proof-of-concept organizations. To fuel their pipelines, some pioneers started to complement their internal R&D efforts through collaborations as early as the 1990s. In recent years, multiple extrinsic and intrinsic factors induced an opening for external sources of innovation and resulted in new models for open innovation, such as open sourcing, crowdsourcing, public-private partnerships, innovations centres, and the virtualization of R&D. Three factors seem to determine the breadth and depth regarding how companies approach external innovation: (1) the company's legacy, (2) the company's willingness and ability to take risks and (3) the company's need to control IP and competitors. In addition, these factors often constitute the major hurdles to effectively leveraging external opportunities and assets. Conscious and differential choices of the R&D and business models for different companies and different divisions in the same company seem to best allow a company to fully exploit the potential of both internal and external innovations.

  17. Semiconductor light sources fabricated by vapor phase epitaxial regrowth

    International Nuclear Information System (INIS)

    Powazinik, W.; Olshansky, R.; Meland, E.; Lauer, R.B.

    1986-01-01

    An extremely versatile technique for the fabrication of semiconductor light sources is described. The technique which is based on the halide vapor phase regrowth (VPR) of InP on channeled and selectively etched InGaAsP/InP double heterostructure material, results in a buried heterostructure (BH) index-guided VPR-BH diode laser structure which can be optimized for a number of different types of semiconductor light sources. The conditions and parameters associated with the halide VPR process are given, and the properties of the regrown InP are reported. The processing and characterization of high-frequency lasers with 18-GHz bandwidths and high-power lasers with cw single-spatial-mode powers of 60 mW are described. Additionally, the fabrication and characterization of superluminescent LEDs based on the this basic VPR-BH structure are described. These LEDs are capable of coupling more than 80 μW of optical power into a single-mode fiber at 100 mA, and can couple as much as 8 μW of optical power into a single-mode fiber at drive currents as low as 20 mA

  18. Effects of different external carbon sources and electron acceptors on interactions between denitrification and phosphorus removal in biological nutrient removal processes.

    Science.gov (United States)

    Hu, Xiang; Sobotka, Dominika; Czerwionka, Krzysztof; Zhou, Qi; Xie, Li; Makinia, Jacek

    The effects of two different external carbon sources (acetate and ethanol) and electron acceptors (dissolved oxygen, nitrate, and nitrite) were investigated under aerobic and anoxic conditions with non-acclimated process biomass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/(g MLVSS·h) (MLVSS: mixed liquor volatile suspended solids), respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO 2 -N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher denitrification rates were obtained with acetate (1.4 and 0.8 mg N/(g MLVSS·h)) compared to ethanol (1.1 and 0.7 mg N/ (g MLVSS·h)) for both anoxic electron acceptors (nitrate and nitrite).

  19. The sources of sharing externalities: Specialization vs Competition

    OpenAIRE

    Bucci, Alberto; Ushchev, Philip

    2015-01-01

    In this paper, we undertake an in-depth inquiry into the nature of sharing externalities, and study how they affect the market outcome. We show that the key thing for understanding sharing externalities is the interplay between two forces: the specialization/complexity effect, on the one hand, and the competition effect, on the other hand. How the interaction between these two forces generates endogenous increasing returns to scale is definitely understudied in the literature because of the w...

  20. Optical pumping in a microfabricated Rb vapor cell using a microfabricated Rb discharge light source

    International Nuclear Information System (INIS)

    Venkatraman, V.; Kang, S.; Affolderbach, C.; Mileti, G.; Shea, H.

    2014-01-01

    Miniature ( 3 ) vapor-cell based devices using optical pumping of alkali atoms, such as atomic clocks and magnetometers, today mostly employ vertical-cavity surface-emitting lasers as pump light sources. Here, we report on the demonstration of optical pumping in a microfabricated alkali vapor resonance cell using (1) a microfabricated Rb discharge lamp light source, as well as (2) a conventional glass-blown Rb discharge lamp. The microfabricated Rb lamp cell is a dielectric barrier discharge (DBD) light source, having the same inner cell volume of around 40 mm 3 as that of the resonance cell, both filled with suitable buffer gases. A miniature (∼2 cm 3 volume) test setup based on the M z magnetometer interrogation technique was used for observation of optical-radiofrequency double-resonance signals, proving the suitability of the microfabricated discharge lamp to introduce efficient optical pumping. The pumping ability of this light source was found to be comparable to or even better than that of a conventional glass-blown lamp. The reported results indicate that the micro-fabricated DBD discharge lamp has a high potential for the development of a new class of miniature atomic clocks, magnetometers, and quantum sensors

  1. A study of light hydrocarbons (C{sub 4}-C{sub 1}3) in source rocks and petroleum fluid

    Energy Technology Data Exchange (ETDEWEB)

    Odden, Wenche

    2000-07-01

    This thesis consists of an introduction and five included papers. Of these, four papers are published in international journals and the fifth was submitted for review in April 2000. Emphasis has been placed on both naturally and artificially generated light hydrocarbons in petroleum fluids and their proposed source rocks as well as direct application of light hydrocarbons to oil/source rock correlations. Collectively, these papers describe a strategy for interpreting the source of the light hydrocarbons in original oils and condensates as well as the source of the asphaltene fractions from the reservoir fluids. The influence of maturity on light hydrocarbon composition has also been evaluated. The papers include (1) compositional data on the light hydrocarbons from thermal extracts and kerogen pyrolysates of sediment samples, (2) light hydrocarbon data of oils and condensates as well as the pyrolysis products of the asphaltenes from these fluids, (3) assessment of compositional alteration effects, such as selective losses of light hydrocarbons due to evaporation, thermal maturity, phase fractionation and biodegradation, (4) comparison of naturally and artificially generated light hydrocarbons, and (5) compound-specific carbon isotope analysis of the whole range of hydrocarbons of all sample types. (author)

  2. Studies on {sup 63}Ni based check-light sources for TL readers

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, J.S.; Venkataraman, G. [Bhabha Atomic Research Centre, Bombay (India). Radiation Protection Services Div.; Udhayakyumar, J. [Bhabha Atomic Research Centre, Bombay (India). Board of Radiation and Isotope Technology; Page, A.G. [Bhabha Atomic Research Centre, Bombay (India). Radiochemistry Div.

    1995-12-31

    The performance of indigenously produced, electrodeposited {sup 63}Ni sources having 10 mm x 10 mm active area and individually coupled to a plastic scintillator has been studied. TL phosphors such as CaF{sub 2}, CaF{sub 2}:Dy, CaF{sub 2}:Tm, CaF{sub 2}:Eu, TLD-100 and CaSO{sub 4}:Dy with {sup 63}Ni have been studied for their possible use as check-light sources for testing TL readers. Stability at ambient temperatures (298-323 K), build-up and decrease of light output with time have been examined. A preliminary study of the fluorescent species in the gamma irradiated plastic scintillator has been made. (author).

  3. Statistical properties of intensity of partially polarised semiconductor laser light backscattered by a single-mode optical fibre

    International Nuclear Information System (INIS)

    Alekseev, A E; Potapov, V T; Gorshkov, B G

    2015-01-01

    We report the results of studying statistical properties of the intensity of partially polarised coherent light backscattered by a single mode optical fibre. An expression is derived for the deviation of the backscattered light intensity depending on the scattering region length, the degree of the light source coherence and the degree of scattered light polarisation. It is shown that the backscattered light in a fibre scattered-light interferometer is partially polarised with the polarisation degree P = 1/3 in the case of external perturbations of the interferometer fibre. (scattering of light)

  4. Ground motion measurements at the LBL Light Source site, the Bevatron and at SLAC

    International Nuclear Information System (INIS)

    Green, M.A.; Majer, E.I.; More, V.D.; O'Connell, D.R.; Shilling, R.C.

    1986-12-01

    This report describes the technique for measuring ground motion at the site of the 1.0 to 2.0 GeV Synchrotron Radiation Facility which was known as the Advanced Light Source (in 1983 when the measurements were taken). The results of ground motion measurements at the Light Source site at Building 6 at LBL are presented. As comparison, ground motion measurements were made at the Byerly Tunnel, the Bevatron, Blackberry Canyon, and SLAC at the Spear Ring. Ground Motion at the Light Source site was measured in a band from 4 to 100 Hz. The measured noise is primarily local in origin and is not easily transported through LBL soils. The background ground motion is for the most part less than 0.1 microns. Localized truck traffic near Building 6 and the operation of the cranes in the building can result in local ground motions of a micron or more for short periods of time. The background motion at Building 6 is between 1 and 2 orders of magnitude higher than ground motion in a quiet seismic tunnel, which is representative of quiet sites worldwide. The magnitude of the ground motions at SLAC and the Bevatron are comparable to ground motions measured at the Building 6 Light Source site. However, the frequency signature of each site is very different

  5. Measurement and correction of chromaticity in Hefei light source

    International Nuclear Information System (INIS)

    Sun Baogen; Xu Hongliang; He Duohui; Wang Junhua; Lu Ping

    2001-01-01

    The measurement and correction of chromaticity for Hefei light source is introduced. The natural chromaticity is obtained by detecting the variation of the betatron tune with the main dipole field strength. The correction chromaticity is obtained by detecting the variation of the betatron tune with the RF frequency. The theoretic analysis and formula for the two methods is given. The measurement results of chromaticity are given

  6. A NEW THERMIONIC RF ELECTRON GUN FOR SYNCHROTRON LIGHT SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Kutsaev, Sergey; Agustsson, R.; Hartzell, J; Murokh, A.; Nassiri, A.; Savin, E.; Smirnov, A.V.; Smirnov, A. Yu; Sun, Y.; Verma, A; Waldschmidt, Geoff; Zholents, A.

    2017-06-02

    A thermionic RF gun is a compact and efficient source of electrons used in many practical applications. RadiaBeam Systems and the Advanced Photon Source at Argonne National Laboratory collaborate in developing of a reliable and robust thermionic RF gun for synchrotron light sources which would offer substantial improvements over existing thermionic RF guns and allow stable operation with up to 1A of beam peak current at a 100 Hz pulse repetition rate and a 1.5 μs RF pulse length. In this paper, we discuss the electromagnetic and engineering design of the cavity and report the progress towards high power tests of the cathode assembly of the new gun.

  7. Solar concentrator with integrated tracking and light delivery system with collimation

    Science.gov (United States)

    Maxey, Lonnie Curt

    2015-06-09

    A solar light distribution system includes a solar light concentrator that is affixed externally to a light transfer tube. Solar light waves are processed by the concentrator into a collimated beam of light, which is then transferred through a light receiving port and into the light transfer tube. A reflector directs the collimated beam of light through the tube to a light distribution port. The interior surface of the light transfer tube is highly reflective so that the light transfers through the tube with minimal losses. An interchangeable luminaire is attached to the light distribution port and distributes light inside of a structure. A sun tracking device rotates the concentrator and the light transfer tube to optimize the receiving of solar light by the concentrator throughout the day. The system provides interior lighting, uses only renewable energy sources, and releases no carbon dioxide emissions into the atmosphere.

  8. Solar concentrator with integrated tracking and light delivery system with summation

    Science.gov (United States)

    Maxey, Lonnie Curt

    2015-05-05

    A solar light distribution system includes a solar light concentrator that is affixed externally to a light transfer tube. Solar light waves are processed by the concentrator into a collimated beam of light, which is then transferred through a light receiving port and into the light transfer tube. A reflector redirects the collimated beam of light through the tube to a light distribution port. The interior surface of the light transfer tube is highly reflective so that the light transfers through the tube with minimal losses. An interchangeable luminaire is attached to the light distribution port and provides light inside of a structure. A sun tracking device rotates the concentrator and the light transfer tube to optimize the receiving of solar light by the concentrator throughout the day. The system provides interior lighting that uses only renewable energy sources, and releases no carbon dioxide emissions into the atmosphere.

  9. Classification of light sources and their interaction with active and passive environments

    Science.gov (United States)

    El-Dardiry, Ramy G. S.; Faez, Sanli; Lagendijk, Ad

    2011-03-01

    Emission from a molecular light source depends on its optical and chemical environment. This dependence is different for various sources. We present a general classification in terms of constant-amplitude and constant-power sources. Using this classification, we have described the response to both changes in the local density of states and stimulated emission. The unforeseen consequences of this classification are illustrated for photonic studies by random laser experiments and are in good agreement with our correspondingly developed theory. Our results require a revision of studies on sources in complex media.

  10. Classification of light sources and their interaction with active and passive environments

    International Nuclear Information System (INIS)

    El-Dardiry, Ramy G. S.; Faez, Sanli; Lagendijk, Ad

    2011-01-01

    Emission from a molecular light source depends on its optical and chemical environment. This dependence is different for various sources. We present a general classification in terms of constant-amplitude and constant-power sources. Using this classification, we have described the response to both changes in the local density of states and stimulated emission. The unforeseen consequences of this classification are illustrated for photonic studies by random laser experiments and are in good agreement with our correspondingly developed theory. Our results require a revision of studies on sources in complex media.

  11. A comparative study of noise in supercontinuum light sources for ultra-high resolution optical coherence tomography

    DEFF Research Database (Denmark)

    Maria J., Sanjuan-Ferrer,; Bravo Gonzalo, Ivan; Bondu, Magalie

    2017-01-01

    Supercontinuum (SC) light is a well-established technology, which finds applications in several domains ranging from chemistry to material science and imaging systems [1-2]. More specifically, its ultra-wide optical bandwidth and high average power make it an ideal tool for Optical Coherence...... Tomography (OCT). Over the last 5 years, numerous examples have demonstrated its high potential [3-4] in this context. However, SC light sources present pulse-to-pulse intensity variation that can limit the performance of any OCT system [5] by degrading their signal to noise ratio (SNR). To this goal, we...... have studied and compared the noise of several SC light sources and evaluated how their noise properties affect the performance of Ultra-High Resolution OCT (UHR-OCT) at 1300 nm. We have measured several SC light sources with different parameters (pulse length, energy, seed repetition rate, etc.). We...

  12. Combined effects of blue light and supplemental far-red light and effects of increasing red light with constant far-red light on growth of kidney bean [Phaseolus vulgaris] under mixtures of narrow-band light sources

    International Nuclear Information System (INIS)

    Hanyu, H.; Shoji, K.

    2000-01-01

    Increasing blue light and decreasing R: FR with supplementary far-red light affect morphogenesis, dry matter production and dry matter partitioning to leaves, stems and roots. In this study, the combined effects of the two spectral treatments were examined in kidney bean (Phaseolus vulgaris L.) grown under the mixture of four different narrow-band light sources. In addition, because the leaf and stem growth are accelerated by increasing red light (600-700 nm) in proportion to far-red light (700-800 nm) while keeping R : FR constant, this study was conducted to determine whether red light or far-red light causes the acceleration of growth. Increasing blue light (400-500 nm) and decreasing R : FR only interacted on stem extension. The results illustrated with figures suggest that blue light amplifies or attenuates the acceleration of stem extension caused by decreasing R : FR. On the other hand, increasing red light with constant far-red light had no influence on leaf expansion or stem extension while R : FR increased. Because the acceleration of leaf and stem growth is caused by increasing either far-red light or both red and far-red light in our environmental conditions, the stimulative effects on leaves and stems seem to require increases in far-red light rather than red light

  13. Optical meta-atom for localization of light with quantized energy.

    Science.gov (United States)

    Lannebère, Sylvain; Silveirinha, Mário G

    2015-10-30

    The capacity to confine light into a small region of space is of paramount importance in many areas of modern science. Here we suggest a mechanism to store a quantized 'bit' of light--with a very precise amount of energy--in an open core-shell plasmonic structure ('meta-atom') with a nonlinear optical response. Notwithstanding the trapped light state is embedded in the radiation continuum, its lifetime is not limited by the radiation loss. Interestingly, it is shown that the interplay between the nonlinear response and volume plasmons enables breaking fundamental reciprocity restrictions, and coupling very efficiently an external light source to the meta-atom. The collision of an incident optical pulse with the meta-atom may be used to release the trapped light 'bit'.

  14. The first synchrotron infrared beamlines at the Advanced Light Source: Spectromicroscopy and fast timing

    International Nuclear Information System (INIS)

    Martin, Michael C.; McKinney, Wayne R.

    1999-01-01

    Two recently commissioned infrared beamlines on the 1.4 bending magnet port at the Advanced Light Source, LBNL, are described. Using a synchrotron as an IR source provides three primary advantages: increased brightness, very fast light pulses, and enhanced far-IR flux. The considerable brightness advantage manifests itself most beneficially when performing spectroscopy on a microscopic length scale. Beamline (BL) 1.4.3 is a dedicated FTIR spectromicroscopy beamline, where a diffraction-limited spot size using the synchrotron source is utilized. BL 1.4.2 consists of a vacuum FTIR bench with a wide spectral range and step-scan capability. This BL makes use of the pulsed nature of the synchrotron light as well as the far-IR flux. Fast timing is demonstrated by observing the pulses from the electron bunch storage pattern at the ALS. Results from several experiments from both IR beamlines will be presented as an overview of the IR research currently being done at the ALS

  15. Stechiometric neodymium compounds as new materials for light sources in integrated optics

    International Nuclear Information System (INIS)

    Malinowski, M.

    1981-01-01

    Short review of physico-chemical properties of stechiometric neodymium compounds has been presented. Several constructions of minilasers as promising light sources for integrated optics devices have been described. (author)

  16. Flexible power 90W to 120W ArF immersion light source for future semiconductor lithography

    Science.gov (United States)

    Burdt, R.; Thornes, J.; Duffey, T.; Bibby, T.; Rokitski, R.; Mason, E.; Melchior, J.; Aggarwal, T.; Haran, D.; Wang, J.; Rechtsteiner, G.; Haviland, M.; Brown, D.

    2014-03-01

    Semiconductor market demand for improved performance at lower cost continues to drive enhancements in excimer light source technologies. Increased output power, reduced variability in key light source parameters, and improved beam stability are required of the light source to support immersion lithography, multi-patterning, and 450mm wafer applications in high volume semiconductor manufacturing. To support future scanner needs, Cymer conducted a technology demonstration program to evaluate the design elements for a 120W ArFi light source. The program was based on the 90W XLR 600ix platform, and included rapid power switching between 90W and 120W modes to potentially support lot-to-lot changes in desired power. The 120W requirements also included improved beam stability in an exposure window conditionally reduced by 20%. The 120W output power is achieved by efficiency gains in system design, keeping system input power at the same level as the 90W XLR 600ix. To assess system to system variability, detailed system testing was conducted from 90W - 120W with reproducible results.

  17. Scientific opportunities at the advanced light source

    International Nuclear Information System (INIS)

    Robinson, A.L.

    1989-01-01

    The Advaned Light Source (ALS) is a national used facility for the production of high-brightness and partially coherent X-ray and ultraviolet synchrotron radiation. Now under construction at the Lawrence Berkeley Laboratory with a projected completion date of September 1992, the ALS is based on a low-emittance electron storage ring optimized for operation at 1.5 GeV with insertion devices in eleven long straight sections. It will also have up to 48 bending-magnet ports. Scientific opportunities in materials science, surface science, chemistry, atomic and molecular physics, life science, and other fields are reflected in Letters of Interest received for the establishment of beamlines. (orig.)

  18. Chemical Dynamics at the Advanced Light Source

    International Nuclear Information System (INIS)

    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.

    1999-01-01

    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

  19. 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...

  20. 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.

  1. Colored dissolved organic matter in shallow estuaries: relationships between carbon sources and light attenuation

    Science.gov (United States)

    Oestreich, W. K.; Ganju, N. K.; Pohlman, J. W.; Suttles, S. E.

    2016-02-01

    Light availability is of primary importance to the ecological function of shallow estuaries. For example, benthic primary production by submerged aquatic vegetation is contingent upon light penetration to the seabed. A major component that attenuates light in estuaries is colored dissolved organic matter (CDOM). CDOM is often measured via a proxy, fluorescing dissolved organic matter (fDOM), due to the ease of in situ fDOM sensor measurements. Fluorescence must be converted to CDOM absorbance for use in light attenuation calculations. However, this CDOM-fDOM relationship varies among and within estuaries. We quantified the variability in this relationship within three estuaries along the mid-Atlantic margin of the eastern United States: West Falmouth Harbor (MA), Barnegat Bay (NJ), and Chincoteague Bay (MD/VA). Land use surrounding these estuaries ranges from urban to developed, with varying sources of nutrients and organic matter. Measurements of fDOM (excitation and emission wavelengths of 365 nm (±5 nm) and 460 nm (±40 nm), respectively) and CDOM absorbance were taken along a terrestrial-to-marine gradient in all three estuaries. The ratio of the absorption coefficient at 340 nm (m-1) to fDOM (QSU) was higher in West Falmouth Harbor (1.22) than in Barnegat Bay (0.22) and Chincoteague Bay (0.17). The CDOM : fDOM absorption ratio was variable between sites within West Falmouth Harbor and Barnegat Bay, but consistent between sites within Chincoteague Bay. Stable carbon isotope analysis for constraining the source of dissolved organic matter (DOM) in West Falmouth Harbor and Barnegat Bay yielded δ13C values ranging from -19.7 to -26.1 ‰ and -20.8 to -26.7 ‰, respectively. Concentration and stable carbon isotope mixing models of DOC (dissolved organic carbon) indicate a contribution of 13C-enriched DOC in the estuaries. The most likely source of 13C-enriched DOC for the systems we investigated is Spartina cordgrass. Comparison of DOC source to CDOM : f

  2. Light emitting diodes as a plant lighting source

    Energy Technology Data Exchange (ETDEWEB)

    Bula, R.J.; Tennessen, D.J.; Morrow, R.C. [Wisconsin Center for Space Automation and Robotics, Madison, WI (United States); Tibbitts, T.W. [Univ. of Wisconsin, Madison, WI (United States)

    1994-12-31

    Electroluminescence in solid materials is defined as the generation of light by the passage of an electric current through a body of solid material under an applied electric field. A specific type of electroluminescence, first noted by Lossew in 1923, involves the generation of photons when electrons are passed through a p-n junction of certain solid materials (junction of a n-type semiconductor, an electron donor, and a p-type semiconductor, an electron acceptor). Development efforts to translate these observations into visible light emitting devices, however, was not undertaken until the 1950s. The term, light emitting diode (LEDs), was first used in a report by Wolfe, et al., in 1955. The development of this light emitting semiconductor technology dates back less than 30 years. During this period of time, the LED has evolved from a rare and expensive light generating device to one of the most widely used electronic components. The most popular applications of the LED are as indicators or as optoelectronic switches. However, several recent advances in LED technology have made possible the utilization of LEDs for applications that require a high photon flux, such as for plant lighting in controlled environments. The new generation of LEDs based on a gallium aluminum arsenide (GaAlAS) semiconductor material fabricated as a double heterostructure on a transparent substrate has opened up many new applications for these LEDs.

  3. 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.

  4. The Advanced Light Source at Lawrence Berkeley Laboratory

    International Nuclear Information System (INIS)

    Robinson, A.L.; Perera, R.C.C.; Schlachter, A.S.

    1991-10-01

    The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL), scheduled to be operational in the spring of 1993 as a US Department of Energy national user facility, will be a next- generation source of soft x-ray and ultraviolet (XUV) synchrotron radiation. Undulators will provide the world's brightest synchrotron radiation at photon energies from below 10 eV to above 2 keV; wiggler and bend-magnet radiation will extend the spectral coverage with high fluxes above 10 keV. These capabilities will support an extensive research program in a broad spectrum of scientific and technological areas in which XUV radiation is used to study and manipulate matter in all its varied gaseous, liquid, and solid forms. The ALS will also serve those interested in developing the fabrication technology for micro- and nanostructures, as well as characterizing them

  5. 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.

  6. A CMOS microdisplay with integrated controller utilizing improved silicon hot carrier luminescent light sources

    Science.gov (United States)

    Venter, Petrus J.; Alberts, Antonie C.; du Plessis, Monuko; Joubert, Trudi-Heleen; Goosen, Marius E.; Janse van Rensburg, Christo; Rademeyer, Pieter; Fauré, Nicolaas M.

    2013-03-01

    Microdisplay technology, the miniaturization and integration of small displays for various applications, is predominantly based on OLED and LCoS technologies. Silicon light emission from hot carrier electroluminescence has been shown to emit light visibly perceptible without the aid of any additional intensification, although the electrical to optical conversion efficiency is not as high as the technologies mentioned above. For some applications, this drawback may be traded off against the major cost advantage and superior integration opportunities offered by CMOS microdisplays using integrated silicon light sources. This work introduces an improved version of our previously published microdisplay by making use of new efficiency enhanced CMOS light emitting structures and an increased display resolution. Silicon hot carrier luminescence is often created when reverse biased pn-junctions enter the breakdown regime where impact ionization results in carrier transport across the junction. Avalanche breakdown is typically unwanted in modern CMOS processes. Design rules and process design are generally tailored to prevent breakdown, while the voltages associated with breakdown are too high to directly interact with the rest of the CMOS standard library. This work shows that it is possible to lower the operating voltage of CMOS light sources without compromising the optical output power. This results in more efficient light sources with improved interaction with other standard library components. This work proves that it is possible to create a reasonably high resolution microdisplay while integrating the active matrix controller and drivers on the same integrated circuit die without additional modifications, in a standard CMOS process.

  7. High-efficiency white organic light-emitting diodes using thermally activated delayed fluorescence

    International Nuclear Information System (INIS)

    Nishide, Jun-ichi; Hiraga, Yasuhide; Nakanotani, Hajime; Adachi, Chihaya

    2014-01-01

    White organic light-emitting diodes (WOLEDs) have attracted much attention recently, aimed for next-generation lighting sources because of their high potential to realize high electroluminescence efficiency, flexibility, and low-cost manufacture. Here, we demonstrate high-efficiency WOLED using red, green, and blue thermally activated delayed fluorescence materials as emissive dopants to generate white electroluminescence. The WOLED has a maximum external quantum efficiency of over 17% with Commission Internationale de l'Eclairage coordinates of (0.30, 0.38).

  8. 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 ...

  9. Optical pumping in a microfabricated Rb vapor cell using a microfabricated Rb discharge light source

    Energy Technology Data Exchange (ETDEWEB)

    Venkatraman, V.; Kang, S.; Affolderbach, C.; Mileti, G., E-mail: gaetano.mileti@unine.ch [Laboratoire Temps-Fréquence, University of Neuchâtel, Neuchâtel 2000 (Switzerland); Shea, H. [Microsystems for Space Technologies Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel 2002 (Switzerland)

    2014-02-03

    Miniature (light sources. Here, we report on the demonstration of optical pumping in a microfabricated alkali vapor resonance cell using (1) a microfabricated Rb discharge lamp light source, as well as (2) a conventional glass-blown Rb discharge lamp. The microfabricated Rb lamp cell is a dielectric barrier discharge (DBD) light source, having the same inner cell volume of around 40 mm{sup 3} as that of the resonance cell, both filled with suitable buffer gases. A miniature (∼2 cm{sup 3} volume) test setup based on the M{sub z} magnetometer interrogation technique was used for observation of optical-radiofrequency double-resonance signals, proving the suitability of the microfabricated discharge lamp to introduce efficient optical pumping. The pumping ability of this light source was found to be comparable to or even better than that of a conventional glass-blown lamp. The reported results indicate that the micro-fabricated DBD discharge lamp has a high potential for the development of a new class of miniature atomic clocks, magnetometers, and quantum sensors.

  10. Modal evaluation of the anthropogenic night sky brightness at arbitrary distances from a light source

    International Nuclear Information System (INIS)

    Bará, Salvador; Ribas, Salvador J; Kocifaj, Miroslav

    2015-01-01

    The artificial emissions of light contribute to a high extent to the observed brightness of the night sky in many places of the world. Determining the all-sky radiance of anthropogenic origin requires solving the radiative transfer equation for ground-level light sources, generally resorting to a double-scattering approximation in order to account for the observed radiance patterns with a reasonable degree of accuracy. Since the all-sky radiance distribution produced by an elementary light source depends on the distance to the observer in a way that is not immediately obvious, the contributions of sources located at different distances have to be computed on an individual basis, solving for each one the corresponding scattering integrals. In this paper we show that these calculations may be significantly alleviated by using a modal approach, whereby the hemispheric night-sky radiance is expanded in terms of a convenient basis of two-dimensional (2D) orthogonal functions. Since the modal coefficients of this expansion do vary smoothly with the distance to the observer, the all-sky brightness distributions produced by light sources located at arbitrary intermediate distances can be efficiently estimated by interpolation, provided that the coefficients at a discrete set of distances are accurately determined beforehand. (paper)

  11. NBS SURF 11: A small versatile synchrotron light source

    International Nuclear Information System (INIS)

    Rakowsky, G.

    1981-01-01

    Synchrotron radiation sources do not have to be large multi-megadollar installations. SURF II is based on a compact electron storage ring with a radius of only 0.84 m, an operating energy of 250 MeV, and useful light output down to 5 nm. Small beam size, high brightness and wide-angle light ports give SURF II unique capabilities. Presently five beamlines are instrumented and operational, supporting experiments in atomic and molecular physics, surface science and materials studies, as well as providing optical calibration services. Nearing completion is a large facility for calibrating optical instruments, especially those intended for space flight. The capability of determining the absolute light flux emitted by SURF II has recently been improved and is now operational. The technique employs ultralinear silicon photodiodes to detect and count individual electrons in the stored beam. Other user conveniences include close access to the machine, flexible scheduling and close interaction with the operations staff. The machine's simplicity contributes to reliability and a high ratio of beamtime to downtime

  12. Scientific capabilities of the advanced light source for radioactive materials

    International Nuclear Information System (INIS)

    Shuh, D.K.

    2007-01-01

    The Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory (LBNL) is a third-generation synchrotron radiation light source and is a U.S. Department of Energy (DOE) national user facility. Currently, the ALS has approximately forty-five operational beamlines spanning a spectrum of scientific disciplines, and provides scientific opportunities for more than 2 000 users a year. Access to the resources of the ALS is through a competitive proposal mechanism within the general user program. Several ALS beamlines are currently being employed for a range of radioactive materials investigations. These experiments are reviewed individually relying on a graded hazard approach implemented by the ALS in conjunction with the LBNL Environmental, Health, and Safety (EH and S) Radiation Protection Program. The ALS provides radiological work authorization and radiological control technician support and assistance for accepted user experimental programs. LBNL has several radioactive laboratory facilities located near the ALS that provide support for ALS users performing experiments with radioactive materials. The capabilities of the ALS beamlines for investigating radioactive materials are given and examples of several past studies are summarised. (author)

  13. Science research with high-brilliance synchrotron light source

    International Nuclear Information System (INIS)

    Sanyal, Milan K.

    2013-01-01

    Synchrotron-science has changed dramatically since the development of high brilliance electron accelerator-based light sources in 1990s. In the last twenty years or so, several such facilities have come up, particularly in developed countries, as material characterizations in relevant atmosphere and protein crystallography with tiny-crystals have strong implications in industrial competitiveness. Moreover several new techniques have been developed recently over the entire spectral range of emitted light, from infra-red to high energy X-rays, which have altered our basic understanding of various materials like biomaterials, nanomaterials, soft-matter and semiconductor quantum structures. In addition, rapid development of various X-ray imaging techniques for nondestructive evaluation of compositional/structural homogeneity of engineering materials with nanometer resolution will have tremendous impact in manufacturing industries. As India becomes a developed country, it must have access to such an advanced synchrotron facility in the country that enables knowledge generation in the ever-expanding fields of design-characterization-production of advanced materials and modern medicines. Development of such state-of-the art facility will also enable us to carry out frontier-basic-research in our own country and help us to retain and bring back Indian talents to India. Here we shall discuss briefly the characteristics of a high brilliance synchrotron source and outline the nature of basic and applied science research that can be done with such a state-of-the-art facility. (author)

  14. New ambient pressure photoemission endstation at Advanced Light Source beamline 9.3.2

    KAUST Repository

    Grass, Michael E.; Karlsson, Patrik G.; Aksoy, Funda; Lundqvist, Måns; Wannberg, Björn; Mun, Bongjin S.; Hussain, Zahid; Liu, Zhi

    2010-01-01

    During the past decade, the application of ambient pressure photoemission spectroscopy (APPES) has been recognized as an important in situ tool to study environmental and materials science, energy related science, and many other fields. Several APPES endstations are currently under planning or development at the USA and international light sources, which will lead to a rapid expansion of this technique. The present work describes the design and performance of a new APPES instrument at the Advanced Light Source beamline 9.3.2 at Lawrence Berkeley National Laboratory. This new instrument, Scienta R4000 HiPP, is a result of collaboration between Advanced Light Source and its industrial partner VG-Scienta. The R4000 HiPP provides superior electron transmission as well as spectromicroscopy modes with 16 μm spatial resolution in one dimension and angle-resolved modes with simulated 0.5° angular resolution at 24° acceptance. Under maximum transmission mode, the electron detection efficiency is more than an order of magnitude better than the previous endstation at beamline 9.3.2. Herein we describe the design and performance of the system, which has been utilized to record spectra above 2 mbar. © 2010 American Institute of Physics.

  15. Design and analysis of nuclear battery driven by the external neutron source

    International Nuclear Information System (INIS)

    Wang, Sanbing; He, Chaohui

    2014-01-01

    Highlights: • A new type of space nuclear power called NBDEx is investigated. • NBDEx with 252 Cf has better performance than RTG with similar structure. • Its thermal power gets great improvement with increment of fuel enrichment. • The service life of NBDEx is about 2.96 year. • The launch abortion accident analysis fully demonstrates the advantage of NBDEx. - Abstract: Based on the theory of ADS (Accelerator Driven Subcritical reactor), a new type of nuclear battery was investigated, which was composed of a subcritical fission module and an isotope neutron source, called NBDEx (Nuclear Battery Driven by External neutron source). According to the structure of GPHS-RTG (General Purpose Heat Source Radioisotope Thermoelectric Generator), the fuel cell model and fuel assembly model of NBDEx were set up, and then their performances were analyzed with MCNP code. From these results, it was found that the power and power density of NBDEx were almost six times higher than the RTG’s. For fully demonstrating the advantage of NBDEx, the analysis of its impact factors was performed with MCNP code, and its lifetime was also calculated using the Origen code. These results verified that NBDEx was more suitable for the space missions than RTG

  16. 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.

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

    International Nuclear Information System (INIS)

    Foerster, C.L.

    1995-01-01

    The rings of the National Synchrotron Light Source (NSLS) have been supplying light to numerous users for approximately a decade and recently a fully conditioned machine vacuum at design currents was obtained. A brief description of the x-ray storage ring, the VUV storage ring and their current supply is given along with some of their features. The ultra-high vacuum system employed for the storage rings and their advantages for the necessary stored beam environments are discussed including, a brief history of time. 15 refs., 2 tabs., 8 figs

  18. 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.

  19. Speckle noise reduction on a laser projection display via a broadband green light source.

    Science.gov (United States)

    Yu, Nan Ei; Choi, Ju Won; Kang, Heejong; Ko, Do-Kyeong; Fu, Shih-Hao; Liou, Jiun-Wei; Kung, Andy H; Choi, Hee Joo; Kim, Byoung Joo; Cha, Myoungsik; Peng, Lung-Han

    2014-02-10

    A broadband green light source was demonstrated using a tandem-poled lithium niobate (TPLN) crystal. The measured wavelength and temperature bandwidth were 6.5 nm and 100 °C, respectively, spectral bandwidth was 36 times broader than the periodically poled case. Although the conversion efficiency was smaller than in the periodic case, the TPLN device had a good figure of merit owing to the extremely large bandwidth for wavelength and temperature. The developed broadband green light source exhibited speckle noise approximately one-seventh of that in the conventional approach for a laser projection display.

  20. Monitoring light source for CMS lead tungstate crystal calorimeter at LHC

    CERN Document Server

    Zhang Li Yuan; Zhu Ren Yuan; Liu Dun Can

    2000-01-01

    Light monitoring will serve as an inter calibration for CMS lead tungstate crystals in situ at LHC, which is crucial for maintaining crystal calorimeter's sub percent constant term in the energy resolution. This paper presents the design of the CMS ECAL monitoring light source and high level distribution system. The correlations between variations of the light output and the transmittance for the CMS choice of Y doped PbWO//4 crystals were investigated, and were used to study monitoring linearity and sensitivity as a function of the wavelength. The monitoring wavelength was determined so that a good linearity as well as adequate sensitivity can be achieved. The performance of a custom manufactured tunable laser system is presented. Issues related to monitoring precision are discussed. 29 Refs.

  1. Study and development of a new ECR source creating an intense light ions beam

    International Nuclear Information System (INIS)

    Nyckees, S.

    2012-01-01

    This thesis is in the context of study and design of a new ECR light ion source on LEDA (Laboratory of Research and Development of Accelerators - CEA Saclay), named ALISES (Advanced Light Ions Source Extraction System). As a first step, the magnetic, electrical and mechanical design of the new source is described. Then, simulations were performed to determine the reduction of emittance growth taking into account the reduction of the length of the LBE (Low Energy Beam Line) provided by the source ALISES. With this source, it's also possible to realize a study on the dimensions of the cylindrical plasma chamber. Simulations were performed to better understand the interaction between radiofrequency wave and plasma. Subsequently, experiments on the source ALISES helped highlight, understand and solve problems in the Penning discharges inside the accelerator column. Measurements performed on the plasma have yielded the assumption that the electrons are heated at the entrance of the plasma chamber and thermalized along its entire length to achieve an energy corresponding to the maximum of the ionization cross section for hydrogen. (author) [fr

  2. Status of the CAMD Light Source

    CERN Document Server

    Suller, Victor P; Fedurin, Mikhail; Jines, Paul; Launey, Daren; Miller, Toby; Wang, Yanshan

    2005-01-01

    With the increasing diversity of its research program, the CAMD Light Source has improved its beam brightness and quality. Using a well calibrated model of the lattice, the ring optic has been refined to generate a lower beam emittance of 150 nm.rad and this has been confirmed by measuring the beta values with the modulated quadrupole shunt system. The beam sizes have also been measured with an X-ray pinhole camera and compared to the calculated emittance. The beam orbit is corrected to a standard position referenced to the quadrupole centers to a precision better than 0.5 mm, using a suite of well localized bumps which can also flexibly steer the user photon beams to their requirements. Beam reliability has been improved by bringing into use a VME control system for the energy ramp.

  3. Nonreciprocal propagation of light without external magnetic fields in a semiconductor waveguide isolator with a MnAs layer

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, T. [Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan) and Japan Science and Techonology Agency, SORST (Japan)]. E-mail: ametomo@hotaka.t.u-tokyo.ac.jp; Shimizu, H. [Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan); Japan Science and Techonology Agency, SORST (Japan); Hai, P.N. [Department of Electronic Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Japan Science and Techonology Agency, SORST (Japan); Tanaka, M. [Department of Electronic Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Japan Science and Techonology Agency, SORST (Japan); Nakano, Y. [Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan); Japan Science and Techonology Agency, SORST (Japan)

    2007-03-15

    A 1.5-{mu}m, TM-mode waveguide optical isolator was developed for use in photonic integrated circuits. It consists of an InGaAlAs-based optical waveguide with a ferromagnetic MnAs layer and makes use of nonreciprocal propagation loss of light induced by the magnetized MnAs layer. With a large-remanence MnAs layer grown with the Mn-template epitaxy method, the isolator successfully showed an 8.7 dB/mm isolation ratio without external magnetic fields.

  4. Simulation of multicomponent light source for optical-electronic system of color analysis objects

    Science.gov (United States)

    Peretiagin, Vladimir S.; Alekhin, Artem A.; Korotaev, Valery V.

    2016-04-01

    Development of lighting technology has led to possibility of using LEDs in the specialized devices for outdoor, industrial (decorative and accent) and domestic lighting. In addition, LEDs and devices based on them are widely used for solving particular problems. For example, the LED devices are widely used for lighting of vegetables and fruit (for their sorting or growing), textile products (for the control of its quality), minerals (for their sorting), etc. Causes of active introduction LED technology in different systems, including optical-electronic devices and systems, are a large choice of emission color and LED structure, that defines the spatial, power, thermal and other parameters. Furthermore, multi-element and color devices of lighting with adjustable illumination properties can be designed and implemented by using LEDs. However, devices based on LEDs require more attention if you want to provide a certain nature of the energy or color distribution at all the work area (area of analysis or observation) or surface of the object. This paper is proposed a method of theoretical modeling of the lighting devices. The authors present the models of RGB multicomponent light source applied to optical-electronic system for the color analysis of mineral objects. The possibility of formation the uniform and homogeneous on energy and color illumination of the work area for this system is presented. Also authors showed how parameters and characteristics of optical radiation receiver (by optical-electronic system) affect on the energy, spatial, spectral and colorimetric properties of a multicomponent light source.

  5. Dynamic Control of Particle Deposition in Evaporating Droplets by an External Point Source of Vapor.

    Science.gov (United States)

    Malinowski, Robert; Volpe, Giovanni; Parkin, Ivan P; Volpe, Giorgio

    2018-02-01

    The deposition of particles on a surface by an evaporating sessile droplet is important for phenomena as diverse as printing, thin-film deposition, and self-assembly. The shape of the final deposit depends on the flows within the droplet during evaporation. These flows are typically determined at the onset of the process by the intrinsic physical, chemical, and geometrical properties of the droplet and its environment. Here, we demonstrate deterministic emergence and real-time control of Marangoni flows within the evaporating droplet by an external point source of vapor. By varying the source location, we can modulate these flows in space and time to pattern colloids on surfaces in a controllable manner.

  6. Contribution to the study of the molecular scattering of light. Use of a laser as light source (1963)

    International Nuclear Information System (INIS)

    Slama, L.

    1963-01-01

    The experiments of the molecular scattering of light have been repeated using a ruby laser as a light source. The angular distribution of the scattered light intensity has been measured when the electric vector of the incident beam is either in the plane of observation or perpendicular to that plane. In the first case a good agreement with the Rayleigh theory has been found but this is not true in the second case. The differential cross sections for scattering have been measured for various gases. The values found are two or three times larger than the ones deduced from the classical theory. The possible effect of a variation of the beam intensity upon the linearity of the scattering process has been looked for. (author) [fr

  7. Dipole nano-laser: the effect of an external electric field

    Energy Technology Data Exchange (ETDEWEB)

    Ghannam, T, E-mail: gtalal@hotmail.co [KAIN Institute for Nano-Technology, King Saud University, PO Box 2454, Riyadh 11451 (Saudi Arabia)

    2010-08-14

    Using the Langevin formalism we study the effects an external electromagnetic field induces in a system made of a pumped two-level system (TLS) and a metallic nano-particle (NP) that interact together via their near-fields. The surface plasmons of the NP greatly enhance the scattered light. With the absence of the external EM field the spectral width of the scattered light is broader than that of the system, covering almost the entire optical range. However, with the inclusion the external EM field, a reduction in the spectral width of the scattered light of order of 10-50 times below that of the system is observed for certain parameter regimes.This system exhibits also bistability in the population difference of the TLS with the external field acting as an order parameter, but only for certain values of the noise quanta.

  8. Medium pressure mercury discharge for use as an intense white light source

    International Nuclear Information System (INIS)

    Kitsinelis, S; Devonshire, R; Stone, D A; Tozer, R C

    2005-01-01

    In this paper, we demonstrate the possibilities that exist in developing a high brightness white light source. The lamp employs mercury at a few Torr and is operated with short pulses of the order of 1 μs at a frequency of 10 kHz. The emission spectrum is atomic in nature and the white light is the outcome of a relative enhancement of the mercury yellow lines at 577 and 579 nm with respect to the rest of the visible lines, which shifts the colour coordinates of the source towards the black body locus of the chromaticity diagram. The pulse operation of a lamp containing mercury at a vapour pressure of 20 Torr offers a greater near-UV and visible output compared to a phosphor-uncoated, low-pressure pulsed compact mercury discharge

  9. Gaseous Tritium Light Sources in armament and watches industries

    International Nuclear Information System (INIS)

    Amme, Marcus; Siegenthaler, Roger

    2015-01-01

    The industrial application of Tritium gas enclosed in glass tubes is a modern way illuminating instruments and items wherever instant and independent readability is prerequisite. The GTLS (Gaseous Tritium Light Sources) technology follows the principle of radiation-induced luminescence and supersedes the luminous radioactive paints and their hazards such as particles erasure or heavy isotope use. Enclosure of tritium in glass is a demanding micro technology process and work needs to be performed in controlled areas due to handling of open sources. The storage and transport of the Tritium is done via licensed B(U)-containers coming from heavy water reactor sites, and disposal of radioactive Tritium wastes has to be compliant with national and international regulations for transport and waste management.

  10. Colored dissolved organic matter in shallow estuaries: relationships between carbon sources and light attenuation

    Science.gov (United States)

    Oestreich, W.K.; Ganju, Neil K.; Pohlman, John; Suttles, Steven E.

    2016-01-01

    Light availability is of primary importance to the ecological function of shallow estuaries. For example, benthic primary production by submerged aquatic vegetation is contingent upon light penetration to the seabed. A major component that attenuates light in estuaries is colored dissolved organic matter (CDOM). CDOM is often measured via a proxy, fluorescing dissolved organic matter (fDOM), due to the ease of in situ fDOM sensor measurements. Fluorescence must be converted to CDOM absorbance for use in light attenuation calculations. However, this CDOM–fDOM relationship varies among and within estuaries. We quantified the variability in this relationship within three estuaries along the mid-Atlantic margin of the eastern United States: West Falmouth Harbor (MA), Barnegat Bay (NJ), and Chincoteague Bay (MD/VA). Land use surrounding these estuaries ranges from urban to developed, with varying sources of nutrients and organic matter. Measurements of fDOM (excitation and emission wavelengths of 365 nm (±5 nm) and 460 nm (±40 nm), respectively) and CDOM absorbance were taken along a terrestrial-to-marine gradient in all three estuaries. The ratio of the absorption coefficient at 340 nm (m−1) to fDOM (QSU) was higher in West Falmouth Harbor (1.22) than in Barnegat Bay (0.22) and Chincoteague Bay (0.17). The CDOM : fDOM absorption ratio was variable between sites within West Falmouth Harbor and Barnegat Bay, but consistent between sites within Chincoteague Bay. Stable carbon isotope analysis for constraining the source of dissolved organic matter (DOM) in West Falmouth Harbor and Barnegat Bay yielded δ13C values ranging from −19.7 to −26.1 ‰ and −20.8 to −26.7 ‰, respectively. Concentration and stable carbon isotope mixing models of DOC (dissolved organic carbon) indicate a contribution of 13C-enriched DOC in the estuaries. The most likely source of 13C-enriched DOC for the systems we investigated is Spartina cordgrass. Comparison of

  11. Analysis of insertion device magnet measurements for the Advanced Light Source

    International Nuclear Information System (INIS)

    Marks, S.; Humphries, D.; Kincaid, B.M.; Schlueter, R.; Wang, C.

    1993-07-01

    The Advanced Light Source (ALS), which is currently being commissioned at Lawrence Berkeley Laboratory, is a third generation light source designed to produce XUV radiation of unprecedented brightness. To meet the high brightness goal the storage ring has been designed for very small electron beam emittance and the undulators installed in the ALS are built to a high degree of precision. The allowable magnetic field errors are driven by electron beam and radiation requirements. Detailed magnetic measurements and adjustments are performed on each undulator to qualify it for installation in the ALS. The first two ALS undulators, IDA and IDB, have been installed. This paper describes the program of measurements, data analysis, and adjustments carried out for these two devices. Calculations of the radiation spectrum, based upon magnetic measurements, are included. Final field integral distributions are also shown. Good field integral uniformity has been achieved using a novel correction scheme, which is also described

  12. SLStudio: Open-source framework for real-time structured light

    DEFF Research Database (Denmark)

    Wilm, Jakob; Olesen, Oline Vinter; Larsen, Rasmus

    2014-01-01

    that this software makes real-time 3D scene capture more widely accessible and serves as a foundation for new structured light scanners operating in real-time, e.g. 20 depth images per second and more. The use cases for such scanners are plentyfull, however due to the computational constraints, all public......An open-source framework for real-time structured light is presented. It is called “SLStudio”, and enables real-time capture of metric depth images. The framework is modular, and extensible to support new algorithms for scene encoding/decoding, triangulation, and aquisition hardware. It is the aim...... implementations so far are limited to offline processing. With “SLStudio”, we are making a platform available which enables researchers from many different fields to build application specific real time 3D scanners. The software is hosted at http://compute.dtu.dk/~jakw/slstudio....

  13. Monitoring light source for CMS lead tungstate crystal calorimeter at LHC

    CERN Document Server

    Zhang Liang Ying; Zhu, R Y; Liu, D T

    2001-01-01

    Light monitoring will serve as an intercalibration for Compact Muon Solenoid (CMS) lead tungstate crystals in situ at the Large Hadronic Collider, which is crucial for maintaining crystal calorimeter's subpercent constant term in the energy resolution. This paper presents the design of the CMS electromagnetic calorimeter monitoring light source and high-level distribution system. The correlations between variations of the light output and the transmittance for the CMS choice of yttrium-doped PbWO/sub 4/ crystals were investigated and were used to study monitoring linearity and sensitivity as a function of wavelength. The monitoring wavelength was determined so that a good linearity as well as adequate sensitivity can be achieved. The performance of a custom manufactured tunable laser system is presented. Issues related to monitoring precision are discussed. (12 refs).

  14. 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. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  15. National Synchrotron Light Source 2008 Activity Report

    International Nuclear Information System (INIS)

    Nasta, K.

    2009-01-01

    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 and 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

  16. 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

  17. Designing display primaries with currently available light sources for UHDTV wide-gamut system colorimetry.

    Science.gov (United States)

    Masaoka, Kenichiro; Nishida, Yukihiro; Sugawara, Masayuki

    2014-08-11

    The wide-gamut system colorimetry has been standardized for ultra-high definition television (UHDTV). The chromaticities of the primaries are designed to lie on the spectral locus to cover major standard system colorimetries and real object colors. Although monochromatic light sources are required for a display to perfectly fulfill the system colorimetry, highly saturated emission colors using recent quantum dot technology may effectively achieve the wide gamut. This paper presents simulation results on the chromaticities of highly saturated non-monochromatic light sources and gamut coverage of real object colors to be considered in designing wide-gamut displays with color filters for the UHDTV.

  18. Review of the Elementary Particles Physics in the External Electromagnetic Fields Studies at KEK

    Science.gov (United States)

    Konstantinova, O. Tanaka

    2017-03-01

    High Energy Accelerator Research Organization (KEK [1]) is a world class accelerator-based research laboratory. The field of its scientific interests spreads widely from the study of fundamental properties of matter, particle physics, nuclear physics to materials science, life science, technical researches, and industrial applications. Research outcomes from the laboratory achieved making use of high-energy particle beams and synchrotron radiation. Two synchrotron facilities of KEK, the Photon Factory (PF) ring and the Photon Factory Advanced Ring (PF-AR) are the second biggest synchrotron light source in Japan. A very wide range of the radiated light, from visible light to X-ray, is provided for a variety of materials science, biology, and life science [2]. KEK strives to work closely with national and international research institutions, promoting collaborative research activities. Advanced research and facilities provision are key factors to be at the frontier of the accelerator science. In this review I am going to discuss KEK overall accelerator-based science, and to consider light sources research and development. The state of arts of the current projects with respect to the elementary particles physics in the external electromagnetic fields is also stressed here.

  19. 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.

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

    International Nuclear Information System (INIS)

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

    1994-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-04-01

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

  2. 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.

  3. Toward Control of Matter: Basic Energy Science Needs for a New Class of X-Ray Light Sources

    International Nuclear Information System (INIS)

    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

    2008-01-01

    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 analysis of 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

  4. Review of vacuum systems for x-ray lithography light sources

    International Nuclear Information System (INIS)

    Schuchman, J.C.

    1990-01-01

    This paper will review and give a status report on vacuum systems for X-Ray lithography light sources. It will include conventional machines and compact machines (machines using superconducting magnets). The vacuum systems will be described and compared with regard to basic machine parameters, pumping systems, types of pumps, chamber design and material, gauging and diagnostics, and machine performane. 23 refs., 8 figs., 1 tab

  5. 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

  6. Estimation of light source colours for light pollution assessment.

    Science.gov (United States)

    Ziou, D; Kerouh, F

    2018-05-01

    The concept of the smart city raised several technological and scientific issues including light pollution. There are various negative impacts of light pollution on economy, ecology, and heath. This paper deals with the census of the colour of light emitted by lamps used in a city environment. To this end, we derive a light bulb colour estimator based on Bayesian reasoning, directional data, and image formation model in which the usual concept of reflectance is not used. All choices we made are devoted to designing an algorithm which can be run almost in real-time. Experimental results show the effectiveness of the proposed approach. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. 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

    potentially revolutionary science involves soft excitations such as magnons and phonons; in general, these are well below the resolution that can be probed by today’s optical systems. The study of these low-energy excitations will only move forward if advances are made in high-resolution gratings for the soft X-ray energy region, and higher-resolution crystal analyzers for the hard X-ray region. In almost all the forefront areas of X-ray science today, the main limitation is our ability to focus, monochromate, and manipulate X-rays at the level required for these advanced measurements. To address these issues, the U.S. Department of Energy (DOE) Office of Basic Energy Sciences (BES) sponsored a workshop, X-ray Optics for BES Light Source Facilities, which was held March 27–29, 2013, near Washington, D.C. The workshop addressed a wide range of technical and organizational issues. Eleven working groups were formed in advance of the meeting and sought over several months to define the most pressing problems and emerging opportunities and to propose the best routes forward for a focused R&D program to solve these problems. The workshop participants identified eight principal research directions (PRDs), as follows: Development of advanced grating lithography and manufacturing for high-energy resolution techniques such as soft X-ray inelastic scattering. Development of higher-precision mirrors for brightness preservation through the use of advanced metrology in manufacturing, improvements in manufacturing techniques, and in mechanical mounting and cooling. Development of higher-accuracy optical metrology that can be used in manufacturing, verification, and testing of optomechanical systems, as well as at wavelength metrology that can be used for quantification of individual optics and alignment and testing of beamlines. Development of an integrated optical modeling and design framework that is designed and maintained specifically for X-ray optics. Development of

  8. X-ray Optics for BES Light Source Facilities

    International Nuclear Information System (INIS)

    Mills, Dennis; Padmore, Howard; Lessner, Eliane

    2013-01-01

    and potentially revolutionary science involves soft excitations such as magnons and phonons; in general, these are well below the resolution that can be probed by today's optical systems. The study of these low-energy excitations will only move forward if advances are made in high-resolution gratings for the soft X-ray energy region, and higher-resolution crystal analyzers for the hard X-ray region. In almost all the forefront areas of X-ray science today, the main limitation is our ability to focus, monochromate, and manipulate X-rays at the level required for these advanced measurements. To address these issues, the U.S. Department of Energy (DOE) Office of Basic Energy Sciences (BES) sponsored a workshop, X-ray Optics for BES Light Source Facilities, which was held March 27-29, 2013, near Washington, D.C. The workshop addressed a wide range of technical and organizational issues. Eleven working groups were formed in advance of the meeting and sought over several months to define the most pressing problems and emerging opportunities and to propose the best routes forward for a focused R&D program to solve these problems. The workshop participants identified eight principal research directions (PRDs), as follows: Development of advanced grating lithography and manufacturing for high-energy resolution techniques such as soft X-ray inelastic scattering. Development of higher-precision mirrors for brightness preservation through the use of advanced metrology in manufacturing, improvements in manufacturing techniques, and in mechanical mounting and cooling. Development of higher-accuracy optical metrology that can be used in manufacturing, verification, and testing of optomechanical systems, as well as at wavelength metrology that can be used for quantification of individual optics and alignment and testing of beamlines. Development of an integrated optical modeling and design framework that is designed and maintained specifically for X-ray optics. Development of

  9. Inverse compton light source: a compact design proposal

    Energy Technology Data Exchange (ETDEWEB)

    Deitrick, Kirsten Elizabeth [Old Dominion Univ., Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2017-05-01

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

  10. Quantitative Analysis of VIIRS DNB Nightlight Point Source for Light Power Estimation and Stability Monitoring

    Directory of Open Access Journals (Sweden)

    Changyong Cao

    2014-12-01

    Full Text Available The high sensitivity and advanced onboard calibration on the Visible Infrared Imaging Radiometer Suite (VIIRS Day/Night Band (DNB enables accurate measurements of low light radiances which leads to enhanced quantitative applications at night. The finer spatial resolution of DNB also allows users to examine social economic activities at urban scales. Given the growing interest in the use of the DNB data, there is a pressing need for better understanding of the calibration stability and absolute accuracy of the DNB at low radiances. The low light calibration accuracy was previously estimated at a moderate 15% using extended sources while the long-term stability has yet to be characterized. There are also several science related questions to be answered, for example, how the Earth’s atmosphere and surface variability contribute to the stability of the DNB measured radiances; how to separate them from instrument calibration stability; whether or not SI (International System of Units traceable active light sources can be designed and installed at selected sites to monitor the calibration stability, radiometric and geolocation accuracy, and point spread functions of the DNB; furthermore, whether or not such active light sources can be used for detecting environmental changes, such as aerosols. This paper explores the quantitative analysis of nightlight point sources, such as those from fishing vessels, bridges, and cities, using fundamental radiometry and radiative transfer, which would be useful for a number of applications including search and rescue in severe weather events, as well as calibration/validation of the DNB. Time series of the bridge light data are used to assess the stability of the light measurements and the calibration of VIIRS DNB. It was found that the light radiant power computed from the VIIRS DNB data matched relatively well with independent assessments based on the in situ light installations, although estimates have to be

  11. LED arrays as cost effective and efficient light sources for widefield microscopy.

    Directory of Open Access Journals (Sweden)

    Dinu F Albeanu

    Full Text Available New developments in fluorophores as well as in detection methods have fueled the rapid growth of optical imaging in the life sciences. Commercial widefield microscopes generally use arc lamps, excitation/emission filters and shutters for fluorescence imaging. These components can be expensive, difficult to maintain and preclude stable illumination. Here, we describe methods to construct inexpensive and easy-to-use light sources for optical microscopy using light-emitting diodes (LEDs. We also provide examples of its applicability to biological fluorescence imaging.

  12. 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.

  13. Influence of Light Conditions and Light Sources on Clinical Measurement of Natural Teeth Color using VITA Easyshade Advance 4,0® Spectrophotometer. Pilot Study.

    Science.gov (United States)

    Posavec, Ivona; Prpić, Vladimir; Zlatarić, Dubravka Knezović

    2016-12-01

    The purpose of this study was to evaluate and compare lightness (L), chroma (C) and hue (h), green-red (a) and blue-yellow (b) character of the color of maxillary right central incisors in different light conditions and light sources. Two examiners who were well trained in digital color evaluation participated in the research. Intraclass correlation coefficients (ICCs) were used to analyze intra- and interobserver reliability. The LCh and L*a*b* values were determined at 08.15 and at 10.00 in the morning under three different light conditions. Tooth color was assessed in 10 subjects using intraoral spectrophotometer VITA Easyshade Advance 4.0 ® set at the central region of the vestibular surface of the measured tooth. Intra- and interobserver ICC values were high for both examiners and ranged from 0.57 to 0.99. Statistically significant differences in LCh and L*a*b* values measured in different time of the day and certain light condition were not found (p>0.05). Statistically significant differences in LCh and L*a*b* values measured under three different light conditions were not found, too (p>0.05). VITA Easyshade Advance 4.0 ® is reliable enough for daily clinical work in order to assess tooth color during the fabrication of esthtic appliances because it is not dependent on light conditions and light sources.

  14. Entrepreneurship as re-sourcing

    DEFF Research Database (Denmark)

    Korsgaard, Steffen; Anderson, Alistair; Gaddefors, Johan

    Objectives The purpose of this paper is to re-examine the concept of entrepreneurship in light of the current financial and environmental crisis and its socio-spatial impact. Building on Hudson’s analysis of production in late-capitalist societies, we identify problems inherent in the dominant...... of grounding in material reality, lacking emphasis on environmental externalities and an impoverished conceptualization of spatial relations. Comparing this analysis with the dominant opportunistic image of the entrepreneur, leads us to formulate a critique of this image. In formulating an alternative we build...... The paper presents a “new image” of entrepreneurship as re-sourcing. The concept of re-sourcing emphasizes the dual meaning of the word resource as both a stock of supply and strategy or action adopted in adverse circumstances. Re-sourcing thus signifies a shift in focus from opportunities to resources...

  15. Effects of aqueous humor hydrodynamics on human eye heat transfer under external heat sources.

    Science.gov (United States)

    Tiang, Kor L; Ooi, Ean H

    2016-08-01

    The majority of the eye models developed in the late 90s and early 00s considers only heat conduction inside the eye. This assumption is not entirely correct, since the anterior and posterior chambers are filled aqueous humor (AH) that is constantly in motion due to thermally-induced buoyancy. In this paper, a three-dimensional model of the human eye is developed to investigate the effects AH hydrodynamics have on the human eye temperature under exposure to external heat sources. If the effects of AH flow are negligible, then future models can be developed without taking them into account, thus simplifying the modeling process. Two types of external thermal loads are considered; volumetric and surface irradiation. Results showed that heat convection due to AH flow contributes to nearly 95% of the total heat flow inside the anterior chamber. Moreover, the circulation inside the anterior chamber can cause an upward shift of the location of hotspot. This can have significant consequences to our understanding of heat-induced cataractogenesis. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  16. Toward Femtosecond X-ray Spectroscopy at the Advanced Light Source

    International Nuclear Information System (INIS)

    Chong, Henry Herng Wei

    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

  17. The SAGA Light Source

    International Nuclear Information System (INIS)

    Yoshida, K.; Iwasaki, Y.; Koda, S.; Okajima, S.; Setoyama, H.; Takabayashi, Y.; Tomimasu, T.; Yoshimura, D.; Ohgaki, H.

    2007-01-01

    Saga prefectural government operates a synchrotron light facility mainly for industrial applications of the synchrotron light. The facility comprises a 1.4 GeV storage ring, a 250 MeV linac as an electron injector and beamlines. The lattice of the storage ring is designed to perform as small emittance as 25 nm-radian and has long straight sections of 2.9 m length for installing insertion devices. Three beam lines have been prepared by Saga prefectural government and one by Saga University

  18. Non-invasive three-dimension control of light between turbid layers using a surface quasi-point light source for precorrection.

    Science.gov (United States)

    Qiao, Mu; Liu, Honglin; Pang, Guanghui; Han, Shensheng

    2017-08-29

    Manipulating light non-invasively through inhomogeneous media is an attractive goal in many disciplines. Wavefront shaping and optical phase conjugation can focus light to a point. Transmission matrix method can control light on multiple output modes simultaneously. Here we report a non-invasive approach which enables three-dimension (3D) light control between two turbid layers. A digital optical phase conjugation mirror measured and conjugated the diffused wavefront, which originated from a quasi-point source on the front turbid layer and passed through the back turbid layer. And then, because of memory effect, the phase-conjugated wavefront could be used as a carrier wave to transport a pre-calculated wavefront through the back turbid layer. The pre-calculated wavefront could project a desired 3D light field inside the sample, which, in our experiments, consisted of two 220-grid ground glass plates spaced by a 20 mm distance. The controllable range of light, according to the memory effect, was calculated to be 80 mrad in solid angle and 16 mm on z-axis. Due to the 3D light control ability, our approach may find applications in photodynamic therapy and optogenetics. Besides, our approach can also be combined with ghost imaging or compressed sensing to achieve 3D imaging between turbid layers.

  19. SATELLITE-MOUNTED LIGHT SOURCES AS PHOTOMETRIC CALIBRATION STANDARDS FOR GROUND-BASED TELESCOPES

    Energy Technology Data Exchange (ETDEWEB)

    Albert, J., E-mail: jalbert@uvic.ca [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2 (Canada)

    2012-01-15

    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. Using a campaign of observations of the 532 nm pulsed laser aboard the CALIPSO satellite, collected using a portable network of cameras and photodiodes, we obtain initial measurements of atmospheric extinction, which can apparently be greatly improved by further data of this type. For a future satellite-mounted precision light source, a high-altitude balloon platform under development (together with colleagues) can provide testing as well as observational data for calibration of atmospheric uncertainties.

  20. SATELLITE-MOUNTED LIGHT SOURCES AS PHOTOMETRIC CALIBRATION STANDARDS FOR GROUND-BASED TELESCOPES

    International Nuclear Information System (INIS)

    Albert, J.

    2012-01-01

    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. Using a campaign of observations of the 532 nm pulsed laser aboard the CALIPSO satellite, collected using a portable network of cameras and photodiodes, we obtain initial measurements of atmospheric extinction, which can apparently be greatly improved by further data of this type. For a future satellite-mounted precision light source, a high-altitude balloon platform under development (together with colleagues) can provide testing as well as observational data for calibration of atmospheric uncertainties.

  1. 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

  2. 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.

  3. Experimental stations at I13 beamline at Diamond Light Source

    International Nuclear Information System (INIS)

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

    2013-01-01

    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.

  4. A compact SR light source for x-ray lithography 'AURORA'

    International Nuclear Information System (INIS)

    Toba, Y.

    1990-01-01

    A compact synchrotron radiation (SR) light source called AURORA has been developed for industrial use. It is specially designed for X-ray lithography. AURORA consists of a storage ring, injector microtron and SR light beam lines. The storage ring is a superconducting single magnet machine, designed to accelerate a 150 MeV electron beam to 650 MeV and to store as high as 300 mA current. The injector is a racetrack microtron (RTM) producing a pulsed 150 MeV beam. As many as 16 SR light beam channels are available for AURORA. Prototypes of the storage ring and RTM are constructed, and beam commissioning is performed. A hundred and fifty MeV electron beam of a pulsed current 10 μA from the RTM is successfully injected to the ring and accelerated to 600 MeV and 10 mA current stored with a lifetime of more than 20 hours. The half-integer method investigated is shown to work well with the injection efficiency being found to be very high. Improvement of the design is now under way. (N.K.)

  5. Linac Coherent Light Source Undulator RF BPM System

    International Nuclear Information System (INIS)

    Lill, R.M.; Morrison, L.H.; Waldschmidt, G.J.; Walters, D.R.; Argonne; Johnson, R.; Li, Z.; Smith, S.; Straumann, T.; SLAC

    2007-01-01

    The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL) when it becomes operational in 2009. The LCLS is currently in the construction phase. The beam position monitor (BPM) system planned for the LCLS undulator will incorporate a high-resolution X-band cavity BPM system described in this paper. The BPM system will provide high-resolution measurements of the electron beam trajectory on a pulse-to-pulse basis and over many shots. The X-band cavity BPM size, simple fabrication, and high resolution make it an ideal choice for LCLS beam position detection. We will discuss the system specifications, design, and prototype test results

  6. Green LED as an Effective Light Source for Curing Acrylate-Based Dental Resins in Combination with Irgacure 784

    Directory of Open Access Journals (Sweden)

    Katalin Bukovinszky

    2018-01-01

    Full Text Available Low intensity green light emitting diodes (LED were shown to be an effective light source to induce the photopolymerization of an acrylate-based photocurable dental restorative resin mixture of bisphenol A glycerolate dimethacrylate (BisGMA, triethylene glycol dimethacrylate (TEGDMA, and diurethane dimethacrylate (UDMA, in combination with fluorinated diaryl titanocene (Irgacure 784. Dental matrices were prepared by the LED light source at different intensities. The mechanical properties, such as Vickers microhardness, compressive strength, diametric tensile strength, flexural strength, and E-modulus of the created samples, were investigated. The kinetics of the photopolymerization was followed by Raman spectroscopy and conversion values were determined. It was found that, despite its narrow-emission range centered at a wavelength of 531 nm, the green LED light source is suitable for the preparation of dental matrices with good mechanical properties and high conversion values.

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

    International Nuclear Information System (INIS)

    Ulkue, Dincer; 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

  8. 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

  9. Enhanced Light Output of Dipole Source in GaN-Based Nanorod Light-Emitting Diodes by Silver Localized Surface Plasmon

    Directory of Open Access Journals (Sweden)

    Huamao Huang

    2014-01-01

    Full Text Available The light output of dipole source in three types of light-emitting diodes (LEDs, including the conventional planar LED, the nanorod LED, and the localized surface plasmon (LSP assisted LED by inserting silver nanoparticles in the gaps between nanorods, was studied by use of two-dimensional finite difference time domain method. The height of nanorod and the size of silver nanoparticles were variables for discussion. Simulation results show that a large height of nanorod induces strong wavelength selectivity, which can be significantly enhanced by LSP. On condition that the height of nanorod is 400 nm, the diameter of silver nanoparticle is 100 nm, and the wavelength is 402.7 nm, the light-output efficiency for LSP assisted LED is enhanced by 190% or 541% as compared to the nanorod counterpart or the planar counterpart, respectively. The space distribution of Poynting vector was present to demonstrate the significant enhancement of light output at the resonant wavelength of LSP.

  10. The Atomic, Molecular and Optical Science instrument at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, Ken R. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Department of Applied Physics, Stanford University, 348 Via Pueblo, Stanford, CA 94305 (United States); Bucher, Maximilian; Bozek, John D.; Carron, Sebastian; Castagna, Jean-Charles [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Coffee, Ryan [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Pulse Institute, Stanford University and SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Curiel, G. Ivan; Holmes, Michael; Krzywinski, Jacek; Messerschmidt, Marc; Minitti, Michael; Mitra, Ankush; Moeller, Stefan; Noonan, Peter; Osipov, Timur; Schorb, Sebastian; Swiggers, Michele; Wallace, Alexander; Yin, Jing [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Bostedt, Christoph, E-mail: bostedt@slac.stanford.edu [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Pulse Institute, Stanford University and SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2015-04-17

    A description of the Atomic, Molecular and Optical Sciences (AMO) instrument at the Linac Coherent Light Source is presented. Recent scientific highlights illustrate the imaging, time-resolved spectroscopy and high-power density capabilities of the AMO instrument. The Atomic, Molecular and Optical Science (AMO) instrument at the Linac Coherent Light Source (LCLS) provides a tight soft X-ray focus into one of three experimental endstations. The flexible instrument design is optimized for studying a wide variety of phenomena requiring peak intensity. There is a suite of spectrometers and two photon area detectors available. An optional mirror-based split-and-delay unit can be used for X-ray pump–probe experiments. Recent scientific highlights illustrate the imaging, time-resolved spectroscopy and high-power density capabilities of the AMO instrument.

  11. Photocatalytic Performance of ZnO: Al Films under Different Light Sources

    Directory of Open Access Journals (Sweden)

    Prashant Pradhan

    2012-01-01

    Full Text Available ZnO and Al doped ZnO films were produced by spray pyrolysis. The films were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, UV-vis spectroscopy, and photoluminescence. Their photocatalytic activity was evaluated by the decomposition of the methyl orange dye using different light sources: ultraviolet light, artificial white light, and direct sunlight. The films were also tested under darkness for comparison. The ZnO films were able to degrade the test pollutant under UV and sunlight in more than a 60% after 180 min of irradiation and a scarce degradation was obtained using white light. However, the Al doped ZnO films presented a very high degradation rate not only under UV and sunlight (100% degradation, but also under white light (90% degradation after the same irradiation time. An unexpected high degradation was also obtained in the dark, which indicates that a nonphotonic process is taking place parallel to the photocatalytic process. This can be due to the extra electrons—provided by the aluminum atoms—that migrate to the surface and produce radicals favoring the decomposition process even in the dark. The high activity achieved by the ZnO: Al films under natural conditions can be potentially applied to water treatment processes.

  12. Measurement of reactivity in ADS reactors considering an exponential decay after an interruption in the external proton source

    Energy Technology Data Exchange (ETDEWEB)

    Henrice Junior, Edson; Gonçalves, Alessandro C., E-mail: ejunior@con.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Palma, Daniel A.P., E-mail: dapalma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro - RJ (Brazil)

    2017-07-01

    The online monitoring of reactivity in ADS reactors is of paramount importance for the operations of such systems. This work is dedicated to the prediction of reactivity from a decay of the neutron population after a pulse from the external source. For that, a pulse from an external source in an ADS reactor was simulated with Serpent Reactor Physics code. From the data obtained, it was possible to make an adjustment, based on a combination of exponentials. The coefficient of the exponential for the dominating term of the sum of exponentials is compared to the simplified solution of the neutron diffusion equation, thus obtaining the reactivity. The method used for the adjustment has the advantage of not requiring data that is equally spaced, and of being easily programmable, waiving the use of specific software for linear adjustments. The preliminary results of the research showed a 750 pcm deviation in relation to the value found of -3,630 pcm obtained through point kinetics, and as a result should be the object of further study. (author)

  13. Measurement of reactivity in ADS reactors considering an exponential decay after an interruption in the external proton source

    International Nuclear Information System (INIS)

    Henrice Junior, Edson; Gonçalves, Alessandro C.

    2017-01-01

    The online monitoring of reactivity in ADS reactors is of paramount importance for the operations of such systems. This work is dedicated to the prediction of reactivity from a decay of the neutron population after a pulse from the external source. For that, a pulse from an external source in an ADS reactor was simulated with Serpent Reactor Physics code. From the data obtained, it was possible to make an adjustment, based on a combination of exponentials. The coefficient of the exponential for the dominating term of the sum of exponentials is compared to the simplified solution of the neutron diffusion equation, thus obtaining the reactivity. The method used for the adjustment has the advantage of not requiring data that is equally spaced, and of being easily programmable, waiving the use of specific software for linear adjustments. The preliminary results of the research showed a 750 pcm deviation in relation to the value found of -3,630 pcm obtained through point kinetics, and as a result should be the object of further study. (author)

  14. Practical Investigation for Road Lighting using Renewable Energy Sources

    Directory of Open Access Journals (Sweden)

    Maged A. Abu Adma

    2017-12-01

    Full Text Available Abstract - Hybrid renewable energy systems are recently used to counteract the limitations of solar and wind as solo renewable energy sources due to adverse weather conditions. This study explains a design of a fully independent -off grid- hybrid solar and wind road lighting system according to geography and weather conditions recorded from the National Research Institute of Astronomy and Geophysics. The computerized model is designed step by step by the aid of Simulink-Matlab and the simulation was successfully run to show the performance of each module.

  15. Resolution of point sources of light as analyzed by quantum detection theory.

    Science.gov (United States)

    Helstrom, C. W.

    1973-01-01

    The resolvability of point sources of incoherent thermal light is analyzed by quantum detection theory in terms of two hypothesis-testing problems. In the first, the observer must decide whether there are two sources of equal radiant power at given locations, or whether there is only one source of twice the power located midway between them. In the second problem, either one, but not both, of two point sources is radiating, and the observer must decide which it is. The decisions are based on optimum processing of the electromagnetic field at the aperture of an optical instrument. In both problems the density operators of the field under the two hypotheses do not commute. The error probabilities, determined as functions of the separation of the points and the mean number of received photons, characterize the ultimate resolvability of the sources.

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

    International Nuclear Information System (INIS)

    Sun Baogen; He Duohui; Xu Hongliang; Lu Ping; Wang Junhua; Gao Yunfeng; Wang Lin; Liu Jinying

    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

  17. 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.

  18. Influence of Different Light Sources, Illumination Intensities and Storage Times on the Vitamin C Content in Pasteurized Milk

    OpenAIRE

    ÇAKMAKÇI, Songül; TURGUT, Tamer

    2005-01-01

    The effect of various light sources and illumination intensities on the destruction of vitamin C was determined during the storage of pasteurized milk. For this purpose, raw cow's milk was pasteurized at 72 oC for 15 s, and then stored in 2 different refrigerators (4 ± 1oC) illuminated by fluorescent and tungsten light (normal light) sources with intensities of 1100, 2400 and 5800 lux. As a control group, a pasteurized milk sample was stored at the same temperature under dark conditi...

  19. Endogenous NO3- in the root as a source of substrate for reduction in the light

    International Nuclear Information System (INIS)

    Rufty, T.W. Jr.; Volk, R.J.; MacKown, C.T.

    1987-01-01

    An experiment was conducted to investigate the reduction of endogenous NO 3 - , which had been taken up by plants in darkness, during the course of the subsequent light period. Vegetative, nonnodulated soybean plant (Glycine max [L.]. Merrill, Ransom) were exposed to 1.0 millimolar 15 NO 3 - for 12 hours in darkness and then returned to a solution containing 1.0 millimolar 14 NO 3 - for the 12 hours chase period in the light. Another set of plants was exposed to 15 NO 3 - during the light period to allow a direct comparison of contributions of substrate from the endogenous and exogenous sources. At the end of the 15 NO 3 - exposure in the dark, 70% of the absorbed 15 NO 3 - remained unreduced, and 83% of this unreduced NO 3 - was retained in roots. The pool of endogenous 15 NO 3 - in roots was depleted at a steady rate during the initial 9 hours of light and was utilized almost exclusively in the formation of insoluble reduced-N in leaves. Unlabeled endogenous NO 3 - , which had accumulated in the root prior to the previous dark period, also was depleted in the light. When exogenous 15 NO 3 - was supplied during the light period, the rate of assimilation progressively increased, reflecting an increased rate of uptake and decreased accumulation of NO 3 - in the root tissue. The dark-absorbed endogenous NO 3 - in the root was the primary source of substrate for whole-plant NO 3 - reduction in the first 6 hours of the light period, and exogenous NO 3 - was the primary source of substrate thereafter

  20. 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