Repair of ultraviolet light-induced damage in Micrococcus radiophilus, and extremely resistant microorganism

International Nuclear Information System (INIS)

Lavin, M.F.; Jenkins, A.; Kidson, C.

1976-01-01

Repair of ultraviolet radiation damage was examined in an extremely radioresistant organism, Micrococcus radiophilus. Measurement of the number of thymine-containing dimers formed as a function of ultraviolet dose suggests that the ability of this organism to withstand high doses of ultraviolet radiation (20,000 ergs/mm 2 ) is not related to protective screening by pigments. M. radiophilus carries out a rapid excision of thymine dimers at doses of ultraviolet light up to 10,000 ergs/mm 2 . Synthesis of deoxyribonucleic acid is reduced after irradiation, but after removal of photodamage the rate approaches that in unirradiated cells. A comparison is drawn with Micrococcus luteus and M. radiodurans. We conclude that the extremely high resistance to ultraviolet irradiation in M. radiophilus is at least partly due to the presence of an efficient excision repair system

Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

Energy Technology Data Exchange (ETDEWEB)

Wang, He [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Xu, Yiming [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Ulonska, Stefan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Robinson, Joseph S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Ranitovic, Predrag [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Kaindl, Robert A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division

2015-06-11

Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. In this article, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 10¹³ s^-1 is generated at 22.3 eV, with 5 × 10^-5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Finally, spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications.

Graphene defect formation by extreme ultraviolet generated photoelectrons

NARCIS (Netherlands)

Gao, An; Lee, Christopher James; Bijkerk, Frederik

2014-01-01

We have studied the effect of photoelectrons on defect formation in graphene during extreme ultraviolet (EUV) irradiation. Assuming the major role of these low energy electrons, we have mimicked the process by using low energy primary electrons. Graphene is irradiated by an electron beam with energy

Elastic modulus of Extreme Ultraviolet exposed single-layer graphene

NARCIS (Netherlands)

Mund, Baibhav Kumar; Gao, An; Sturm, Jacobus Marinus; Lee, Christopher James; Bijkerk, Frederik

2015-01-01

Highly transparent membranes are required for a number of applications, such as protective coatings for components in Extreme Ultraviolet (EUV) lithography, beam splitters (EUV pump-probe experiments), transmission gratings, and reticles. Graphene is an excellent candidate due to its high tensile

Infrared diffractive filtering for extreme ultraviolet multilayer Bragg reflectors

NARCIS (Netherlands)

Medvedev, Viacheslav; van den Boogaard, Toine; van der Meer, R.; Yakshin, Andrey; Louis, Eric; Krivtsun, V.M.; Bijkerk, Frederik

2013-01-01

Abstract: We report on the development of a hybrid mirror realized by integrating an EUV-reflecting multilayer coating with a lamellar grating substrate. This hybrid irror acts as an efficient Bragg reflector for extreme ultraviolet (EUV) radiation at a given wavelength while simultaneously

Design and performance of capping layers for extreme-ultraviolet multilayer mirrors

International Nuclear Information System (INIS)

Bajt, Sasa; Chapman, Henry N.; Nguyen, Nhan; Alameda, Jennifer; Robinson, Jeffrey C.; Malinowski, Michael; Gullikson, Eric; Aquila, Andrew; Tarrio, Charles; Grantham, Steven

2003-01-01

Multilayer lifetime has emerged as one of the major issues for the commercialization of extreme-ultraviolet lithography (EUVL). We describe the performance of an oxidation-resistant capping layer of Ru atop multilayers that results in a reflectivity above 69% at 13.2 nm, which is suitable for EUVL projection optics and has been tested with accelerated electron-beam and extreme-ultraviolet (EUV) light in a water-vapor environment. Based on accelerated exposure results, we calculated multilayer lifetimes for all reflective mirrors in a typical commercial EUVL tool and concluded that Ru-capped multilayers have ∼40x longer lifetimes than Si-capped multilayers, which translates to 3 months to many years, depending on the mirror dose

Optical properties and electronic transitions of zinc oxide, ferric oxide, cerium oxide, and samarium oxide in the ultraviolet and extreme ultraviolet

DEFF Research Database (Denmark)

Pauly, N; Yubero, F; Espinós, J P

2017-01-01

Optical properties and electronic transitions of four oxides, namely zinc oxide, ferric oxide, cerium oxide, and samarium oxide, are determined in the ultraviolet and extreme ultraviolet by reflection electron energy loss spectroscopy using primary electron energies in the range 0.3-2.0 ke...

Dynamical structure of extreme ultraviolet macrospicules

Science.gov (United States)

Karovska, Margarita; Habbal, Shadia Rifai

1994-01-01

We describe the substructures forming the macrospicules and their temporal evolution, as revealed by the application of an image enhancement algorithm to extreme ultraviolet (EUV) observations of macrospicules. The enhanced images uncover, for the first time, the substructures forming the column-like structures within the macrospicules and the low-lying arches at their base. The spatial and temporal evolution of macrospicules clearly show continuous interaction between these substructures with occasional ejection of plasma following a ballistic trajectory. We comment on the importance of these results for planning near future space observations of macrospicules with better temporal and spatial resolution.

Photoionization capable, extreme and vacuum ultraviolet emission in developing low temperature plasmas in air

NARCIS (Netherlands)

Stephens, J.; Fierro, A.; Beeson, S.; Laity, G.; Trienekens, D.; Joshi, R.P.; Dickens, J.; Neuber, A.

2016-01-01

Experimental observation of photoionization capable extreme ultraviolet and vacuum ultraviolet emission from nanosecond timescale, developing low temperature plasmas (i.e. streamer discharges) in atmospheric air is presented. Applying short high voltage pulses enabled the observation of the onset of

Equatorial enhancement of the nighttime OH mesospheric infrared airglow

International Nuclear Information System (INIS)

Baker, D J; Thurgood, B K; Harrison, W K; Mlynczak, M G; Russell, J M

2007-01-01

Global measurements of the hydroxyl mesospheric airglow over an extended period of time have been made possible by the NASA SABER infrared sensor aboard the TIMED satellite which has been functioning since December of 2001. The orbital mission has continued over a significant portion of a solar cycle. Experimental data from SABER for several years have exhibited equatorial enhancements of the nighttime mesospheric OH (Δv=2) airglow layer consistent with the high average diurnal solar flux. The brightening of the OH airglow typically means more H+O 3 is being reacted. At both the spring and autumn seasonal equinoxes when the equatorial solar UV irradiance mean is greatest, the peak volume emission rate (VER) of the nighttime Meinel infrared airglow typically appears to be both significantly brighter plus lower in altitude by several kilometres at low latitudes compared with midlatitude findings

GLOBAL SIMULATION OF AN EXTREME ULTRAVIOLET IMAGING TELESCOPE WAVE

International Nuclear Information System (INIS)

Schmidt, J. M.; Ofman, L.

2010-01-01

We use the observation of an Extreme Ultraviolet Imaging Telescope (EIT) wave in the lower solar corona, seen with the two Solar Terrestrial Relations Observatory (STEREO) spacecraft in extreme ultraviolet light on 2007 May 19, to model the same event with a three-dimensional (3D) time-depending magnetohydrodynamic (MHD) code that includes solar coronal magnetic fields derived with Wilcox Solar Observatory magnetogram data, and a solar wind outflow accelerated with empirical heating functions. The model includes a coronal mass ejection (CME) of Gibson and Low flux rope type above the reconstructed active region with parameters adapted from observations to excite the EIT wave. We trace the EIT wave running as circular velocity enhancement around the launching site of the CME in the direction tangential to the sphere produced by the wave front, and compute the phase velocities of the wave front. We find that the phase velocities are in good agreement with theoretical values for a fast magnetosonic wave, derived with the physical parameters of the model, and with observed phase speeds of an incident EIT wave reflected by a coronal hole and running at about the same location. We also produce in our 3D MHD model the observed reflection of the EIT wave at the coronal hole boundary, triggered by the magnetic pressure difference between the wave front hitting the hole and the boundary magnetic fields of the coronal hole, and the response of the coronal hole, which leads to the generation of secondary reflected EIT waves radiating away in different directions than the incident EIT wave. This is the first 3D MHD model of an EIT wave triggered by a CME that includes realistic solar magnetic field, with results comparing favorably to STEREO Extreme Ultraviolet Imager observations.

Extreme Ultraviolet Stokesmeter for Pulsed Magneto-Optics

Directory of Open Access Journals (Sweden)

Mabel Ruiz-Lopez

2015-02-01

Full Text Available Several applications in material science and magnetic holography using extreme ultraviolet (EUV radiation require the measurement of the degree and state of polarization. In this work, an instrument to measure simultaneously both parameters from EUV pulses is presented. The instrument determines the Stokes parameters after a reflection on an array of multilayer mirrors at the Brewster angle. The Stokesmeter was tested at Swiss Light Source at different EUV wavelengths. The experimental Stokes patterns of the source were compared with the simulated pattern.

NIRAC: Near Infrared Airglow Camera for the International Space Station

Science.gov (United States)

Gelinas, L. J.; Rudy, R. J.; Hecht, J. H.

2017-12-01

NIRAC is a space based infrared airglow imager that will be deployed to the International Space Station in late 2018, under the auspices of the Space Test Program. NIRAC will survey OH airglow emissions in the 1.6 micron wavelength regime, exploring the spatial and temporal variability of emission intensities at latitudes from 51° south to 51° north. Atmospheric perturbations in the 80-100 km altitude range, including those produced by atmospheric gravity waves (AGWs), are observable in the OH airglow. The objective of the NIRAC experiment is to make near global measurement of the OH airglow and airglow perturbations. These emissions also provide a bright source of illumination at night, allowing for nighttime detection of clouds and surface characteristics. The instrument, developed by the Aerospace Space Science Applications Laboratory, employs a space-compatible FPGA for camera control and data collection and a novel, custom optical system to eliminate image smear due to orbital motion. NIRAC utilizes a high-performance, large format infrared focal plane array, transitioning technology used in the existing Aerospace Corporation ground-based airglow imager to a space based platform. The high-sensitivity, four megapixel imager has a native spatial resolution of 100 meters at ISS altitudes. The 23° x 23° FOV sweeps out a 150 km swath of the OH airglow layer as viewed from the ISS, and is sensitive to OH intensity perturbations down to 0.1%. The detector has a 1.7 micron cutoff that precludes the need for cold optics and reduces cooling requirements (to 180 K). Detector cooling is provided by a compact, lightweight cryocooler capable of reaching 120K, providing a great deal of margin.

Calibration of windowless photodiode for extreme ultraviolet pulse energy measurement

Czech Academy of Sciences Publication Activity Database

Koláček, Karel; Schmidt, Jiří; Štraus, Jaroslav; Frolov, Oleksandr

2015-01-01

Roč. 54, č. 35 (2015), s. 10454-10459 ISSN 1559-128X R&D Projects: GA MŠk(CZ) LG13029 Institutional support: RVO:61389021 Keywords : Photodetectors * Soft-X-ray * Extreme ultraviolet * Detection * Filters * Metrology Subject RIV: BH - Optics , Masers, Lasers Impact factor: 1.598, year: 2015

Tabletop single-shot extreme ultraviolet Fourier transform holography of an extended object.

Science.gov (United States)

Malm, Erik B; Monserud, Nils C; Brown, Christopher G; Wachulak, Przemyslaw W; Xu, Huiwen; Balakrishnan, Ganesh; Chao, Weilun; Anderson, Erik; Marconi, Mario C

2013-04-22

We demonstrate single and multi-shot Fourier transform holography with the use of a tabletop extreme ultraviolet laser. The reference wave was produced by a Fresnel zone plate with a central opening that allowed the incident beam to illuminate the sample directly. The high reference wave intensity allows for larger objects to be imaged compared to mask-based lensless Fourier transform holography techniques. We obtain a spatial resolution of 169 nm from a single laser pulse and a resolution of 128 nm from an accumulation of 20 laser pulses for an object ~11x11μm(2) in size. This experiment utilized a tabletop extreme ultraviolet laser that produces a highly coherent ~1.2 ns laser pulse at 46.9 nm wavelength.

The Extreme Ultraviolet spectrometer on bard the Hisaki satellite

Science.gov (United States)

Yoshioka, K.; Murakami, G.; Yamazaki, A.; Tsuchiya, F.; Kagitani, M.; Kimura, T.; Yoshikawa, I.

2017-12-01

The extreme ultraviolet spectroscope EXCEED (EXtrem ultraviolet spetrosCope for ExosphEric Dynamics) on board the Hisaki satellite was launched in September 2013 from the Uchinoura space center, Japan. It is orbiting around the Earth with an orbital altitude of around 950-1150 km. This satellite is dedicated to and optimized for observing the atmosphere and magnetosphere of terrestrial planets such as Mercury, Venus, Mars, as well as Jupiter. The instrument consists of an off axis parabolic entrance mirror, switchable slits with multiple filters and shapes, a toroidal grating, and a photon counting detector, together with a field of view guiding camera. The design goal is to achieve a large effective area but with high spatial and spectral resolution. Based on the after-launch calibration, the spectral resolution of EXCEED is found to be 0.3-0.5 nm FWHM (Full Width at Half Maximum) over the entire spectral band, and the spatial resolution is around 17". The evaluated effective area is larger than 1cm2. In this presentation, the basic concept of the instrument design and the observation technique are introduced. The current status of the spacecraft and its future observation plan are also shown.

High intensity vacuum ultraviolet and extreme ultraviolet production by noncollinear mixing in laser vaporized media

Energy Technology Data Exchange (ETDEWEB)

Todt, Michael A.; Albert, Daniel R.; Davis, H. Floyd, E-mail: hfd1@cornell.edu [Baker Laboratory, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301 (United States)

2016-06-15

A method is described for generating intense pulsed vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) laser radiation by resonance enhanced four-wave mixing of commercial pulsed nanosecond lasers in laser vaporized mercury under windowless conditions. By employing noncollinear mixing of the input beams, the need of dispersive elements such as gratings for separating the VUV/XUV from the residual UV and visible beams is eliminated. A number of schemes are described, facilitating access to the 9.9–14.6 eV range. A simple and convenient scheme for generating wavelengths of 125 nm, 112 nm, and 104 nm (10 eV, 11 eV, and 12 eV) using two dye lasers without the need for dye changes is described.

Reflectance Tuning at Extreme Ultraviolet (EUV) Wavelengths with Active Multilayer Mirrors

NARCIS (Netherlands)

Bayraktar, Muharrem; Lee, Christopher James; van Goor, F.A.; Koster, Gertjan; Rijnders, Augustinus J.H.M.; Bijkerk, Frederik

2011-01-01

At extreme ultraviolet (EUV) wavelengths the refractive power of transmission type optical components is limited, therefore reflective components are used. Reflective optics (multilayer mirrors) usually consist of many bilayers and each bilayer is composed of a high and a low refractive index

Remote Sensing of the Upper Atmosphere and the Ionosphere in the Extreme and Far Ultraviolet: Results from the LITES Experiment aboard the IS

Science.gov (United States)

Finn, S. C.; Chakrabarti, S.; Stephan, A. W.; Geddes, G.; Budzien, S. A.; Cook, T.; Aryal, S.; Martel, J.; Galkin, I. A.; Erickson, P. J.

2017-12-01

The Limb-Imaging Ionospheric and Thermospheric Extreme-ultraviolet Spectrograph (LITES) was launched as part of the Space Test Program Houston #5 (STP-H5) payload aboard a commercial resupply flight on February 19, 2017 and was subsequently installed on the International Space Station (ISS). LITES is an imaging spectrograph that spans the 60 - 140 nm wavelength range at 1 nm spectral resolution and samples tangent altitudes 150 - 350 km with 0.2° angular resolution. LITES, in combination with the GPS Radio Occultation and Ultraviolet Photometry - Colocated (GROUP-C) experiment, which includes a GPS receiver and a nadir viewing 135.6 nm photometer, jointly collect new information on the thermosphere and the ionosphere using simultaneous UV and radio emissions. LITES, which uses standard stars to perform in-flight calibration, observes altitude profiles of day and night airglow emissions that are being used to infer thermospheric and ionospheric density profiles. Furthermore, due to the inclination of the ISS, LITES has also observed auroral spectrum and their altitude and spatial variations. Finally, geomagnetic storm effects on its UV emissions can be used to remotely sense their effects on the upper atmospheric morphology. These ISS observations,which are complement to the upcoming ICON and GOLD NASA missions, are focused on ionosphere-atmosphere coupling and global-scale atmospheric response to space weather observed from higher altitudes . We will present an overview of the LITES instrument, some early results from the first few months of operations. We will also summarize the advantages in calibration and validation activities that are possible through space-based LITES, GROUP-C and stellar measurements and simultaneous ground-based optical and radar observations.

Night airglow in RGB mode

Directory of Open Access Journals (Sweden)

Mikhalev А.V.

2016-09-01

Full Text Available To study dynamics of the upper atmosphere, we consider results of the night sky photometry, using a color CCD camera and taking into account the night airglow and features of its spectral composition. We use night airglow observations for 2010–2015, which have been obtained at the ISTP SB RAS Geophysical Observatory (52° N, 103° E by the camera with KODAK KAI-11002 CCD sensor. We estimate average brightness of the night sky in R, G, B channels of the color camera for eastern Siberia with typical values ranging from ~0.008 to 0.01 erg·cm–2·s–1. Besides, we determine seasonal variations in the night sky luminosities in R, G, B channels of the color camera. In these channels, luminosities decrease in spring, increase in autumn, and have a pronounced summer maximum, which can be explained by scattered light and is associated with the location of the Geophysical Observatory. We consider geophysical phenomena with their optical effects in R, G, B channels of the color camera. For some geophysical phenomena (geomagnetic storms, sudden stratospheric warmings, we demonstrate the possibility of quantitative relationship between enhanced signals in R and G channels and increases in intensities of discrete 557.7 and 630 nm emissions, which are predominant in the airglow spectrum

System performance modeling of extreme ultraviolet lithographic thermal issues

International Nuclear Information System (INIS)

Spence, P. A.; Gianoulakis, S. E.; Moen, C. D.; Kanouff, M. P.; Fisher, A.; Ray-Chaudhuri, A. K.

1999-01-01

Numerical simulation is used in the development of an extreme ultraviolet lithography Engineering Test Stand. Extensive modeling was applied to predict the impact of thermal loads on key lithographic parameters such as image placement error, focal shift, and loss of CD control. We show that thermal issues can be effectively managed to ensure that their impact on lithographic performance is maintained within design error budgets. (c) 1999 American Vacuum Society

Bottom Extreme-Ultraviolet-Sensitive Coating for Evaluation of the Absorption Coefficient of Ultrathin Film

Science.gov (United States)

Hijikata, Hayato; Kozawa, Takahiro; Tagawa, Seiichi; Takei, Satoshi

2009-06-01

A bottom extreme-ultraviolet-sensitive coating (BESC) for evaluation of the absorption coefficients of ultrathin films such as extreme ultraviolet (EUV) resists was developed. This coating consists of a polymer, crosslinker, acid generator, and acid-responsive chromic dye and is formed by a conventional spin-coating method. By heating the film after spin-coating, a crosslinking reaction is induced and the coating becomes insoluble. A typical resist solution can be spin-coated on a substrate covered with the coating film. The evaluation of the linear absorption coefficients of polymer films was demonstrated by measuring the EUV absorption of BESC substrates on which various polymers were spin-coated.

Plasma control for efficient extreme ultra-violet source

International Nuclear Information System (INIS)

Takahashi, Kensaku; Nakajima, Mitsuo; Kawamura, Tohru; Shiho, Makoto; Hotta, Eiki; Horioka, Kazuhiko

2008-01-01

To generate a high efficiency extreme-ultraviolet (EUV) source, effects of plasma shape for controlling radiative plasmas based on xenon capillary discharge are experimentally investigated. The radiation characteristics observed via tapered capillary discharge are compared with those of straight one. From the comparison, the long emission period and different plasma behaviors of tapered capillary discharge are confirmed. This means that control of the plasma geometry is effective for prolonging the EUV emission period. This result also indicates that the plasma shape control seems to have a potential for enhancing the conversion efficiency. (author)

Extreme ultraviolet lithography: A few more pieces of the puzzle

Energy Technology Data Exchange (ETDEWEB)

Anderson, Christopher N. [Univ. of California, Berkeley, CA (United States)

2009-05-20

The work described in this dissertation has improved three essential components of extreme ultraviolet (EUV) lithography: exposure tools, photoresist, and metrology. Exposure tools. A field-averaging illumination stage is presented that enables nonuniform, high-coherence sources to be used in applications where highly uniform illumination is required. In an EUV implementation, it is shown that the illuminator achieves a 6.5% peak-to-valley intensity variation across the entire design field of view. In addition, a design for a stand-alone EUV printing tool capable of delivering 15 nm half-pitch sinusoidal fringes with available sources, gratings and nano-positioning stages is presented. It is shown that the proposed design delivers a near zero line-edge-rougness (LER) aerial image, something extremely attractive for the application of resist testing. Photoresist. Two new methods of quantifying the deprotection blur of EUV photoresists are described and experimentally demonstrated. The deprotection blur, LER, and sensitivity parameters of several EUV photoresists are quantified simultaneously as base weight percent, photoacid generator (PAG) weight percent, and post-exposure bake (PEB) temperature are varied. Two surprising results are found: (1) changing base weight percent does not significantly affect the deprotection blur of EUV photoresist, and (2) increasing PAG weight percent can simultaneously reduce LER and E-size in EUV photoresist. The latter result motivates the development of an EUV exposure statistics model that includes the effects of photon shot noise, the PAG spatial distribution, and the changing of the PAG distribution during the exposure. In addition, a shot noise + deprotection blur model is used to show that as deprotection blur becomes large relative to the size of the printed feature, LER reduction from improved counting statistics becomes dominated by an increase in LER due to reduced deprotection contrast. Metrology. Finally, this

Berkeley's Philosophy of Mathematics

CERN Document Server

Jesseph, Douglas M

1993-01-01

In this first modern, critical assessment of the place of mathematics in Berkeley's philosophy and Berkeley's place in the history of mathematics, Douglas M. Jesseph provides a bold reinterpretation of Berkeley's work. Jesseph challenges the prevailing view that Berkeley's mathematical writings are peripheral to his philosophy and argues that mathematics is in fact central to his thought, developing out of his critique of abstraction. Jesseph's argument situates Berkeley's ideas within the larger historical and intellectual context of the Scientific Revolution. Jesseph begins with Berkeley's r

HF-induced airglow at magnetic zenith: theoretical considerations

Directory of Open Access Journals (Sweden)

E. V. Mishin

2005-01-01

Full Text Available Observations of airglow at 630nm (red line and 557.7nm (green line during HF modification experiments at the High Frequency Active Auroral Research Program (HAARP heating facility are analyzed. We propose a theoretical framework for understanding the generation of Langmuir and ion acoustic waves during magnetic zenith injections. We show that observations of HF-induced airglow in an underdense ionosphere as well as a decrease in the height of the emitting volume are consistent with this scenario.

Design, fabrication, and characterization of high-efficiency extreme ultraviolet diffusers

Energy Technology Data Exchange (ETDEWEB)

Naulleau, Patrick P.; Liddle, J. Alexander; Salmassi, Farhad; Anderson, Erik H.; Gullikson, Eric M.

2004-02-19

As the development of extreme ultraviolet (EUV) lithography progresses, interest grows in the extension of traditional optical components to the EUV regime. The strong absorption of EUV by most materials and its extremely short wavelength, however, makes it very difficult to implement many components that are commonplace in the longer wavelength regimes. One such example is the diffuser often implemented with ordinary ground glass in the visible light regime. Here we demonstrate the fabrication of reflective EUV diffusers with high efficiency within a controllable bandwidth. Using these techniques we have fabricated diffusers with efficiencies exceeding 10% within a moderate angular single-sided bandwidth of approximately 0.06 radians.

Three-dimensional characterization of extreme ultraviolet mask blank defects by interference contrast photoemission electron microscopy.

Science.gov (United States)

Lin, Jingquan; Weber, Nils; Escher, Matthias; Maul, Jochen; Han, Hak-Seung; Merkel, Michael; Wurm, Stefan; Schönhense, Gerd; Kleineberg, Ulf

2008-09-29

A photoemission electron microscope based on a new contrast mechanism "interference contrast" is applied to characterize extreme ultraviolet lithography mask blank defects. Inspection results show that positioning of interference destructive condition (node of standing wave field) on surface of multilayer in the local region of a phase defect is necessary to obtain best visibility of the defect on mask blank. A comparative experiment reveals superiority of the interference contrast photoemission electron microscope (Extreme UV illumination) over a topographic contrast one (UV illumination with Hg discharge lamp) in detecting extreme ultraviolet mask blank phase defects. A depth-resolved detection of a mask blank defect, either by measuring anti-node peak shift in the EUV-PEEM image under varying inspection wavelength condition or by counting interference fringes with a fixed illumination wavelength, is discussed.

Shrinking the Synchrotron : Tabletop Extreme Ultraviolet Absorption of Transition-Metal Complexes

NARCIS (Netherlands)

Zhang, Kaili; Lin, Ming Fu; Ryland, Elizabeth S.; Verkamp, Max A.; Benke, Kristin; De Groot, Frank M F; Girolami, Gregory S.; Vura-Weis, Josh

2016-01-01

We show that the electronic structure of molecular first-row transition-metal complexes can be reliably measured using tabletop high-harmonic XANES at the metal M2,3 edge. Extreme ultraviolet photons in the 50-70 eV energy range probe 3p → 3d transitions, with the same selection rules as soft X-ray

Telescience - Concepts and contributions to the Extreme Ultraviolet Explorer mission

Science.gov (United States)

Marchant, Will; Dobson, Carl; Chakrabarti, Supriya; Malina, Roger F.

1987-01-01

It is shown how the contradictory goals of low-cost and fast data turnaround characterizing the Extreme Ultraviolet Explorer (EUVE) mission can be achieved via the early use of telescience style transparent tools and simulations. The use of transparent tools reduces the parallel development of capability while ensuring that valuable prelaunch experience is not lost in the operations phase. Efforts made to upgrade the 'EUVE electronics' simulator are described.

A search for thermal extreme ultraviolet radiation from nearby pulsars

International Nuclear Information System (INIS)

Greenstein, G.; Margon, B.

1977-01-01

We present the first extreme ultraviolet (100-1000 A) observations of radio pulsars. Using an EUV telescope carried aboard the Apollo-Soyuz mission, data were acquired on the nearby pulsars PSR 1133 + 16, 1451 - 68 and 1929 + 10. The data are interpreted to set limits on the effective temperatures of the neutron stars, yielding T 5 K in the best cases, and the limits compared with theoretical predictions. (orig./BJ) [de

77 FR 37604 - Safety Zone; Fourth of July Fireworks, Berkeley Marina, Berkeley, CA

Science.gov (United States)

2012-06-22

...: The Coast Guard will enforce a 1,000 foot safety zone around the Berkeley Pier in position 37[deg]51... Zone; Fourth of July Fireworks, Berkeley Marina, Berkeley, CA AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce the safety zone for the Berkeley...

78 FR 29022 - Safety Zone; Fourth of July Fireworks, Berkeley Marina, Berkeley, CA

Science.gov (United States)

2013-05-17

... Guard will enforce a 1,000 foot safety zone around the Berkeley Pier in approximate position 37[deg]51... Zone; Fourth of July Fireworks, Berkeley Marina, Berkeley, CA AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce the safety zone for the Berkeley...

Masks for extreme ultraviolet lithography

International Nuclear Information System (INIS)

Cardinale, G; Goldsmith, J; Kearney, P A; Larson, C; Moore, C E; Prisbrey, S; Tong, W; Vernon, S P; Weber, F; Yan, P-Y.

1998-01-01

In extreme ultraviolet lithography (EUVL), the technology specific requirements on the mask are a direct consequence of the utilization of radiation in the spectral region between 10 and 15 nm. At these wavelengths, all condensed materials are highly absorbing and efficient radiation transport mandates the use of all-reflective optical systems. Reflectivity is achieved with resonant, wavelength-matched multilayer (ML) coatings on all of the optical surfaces - including the mask. The EUV mask has a unique architecture - it consists of a substrate with a highly reflective ML coating (the mask blank) that is subsequently over-coated with a patterned absorber layer (the mask). Particulate contamination on the EUVL mask surface, errors in absorber definition and defects in the ML coating all have the potential to print in the lithographic process. While highly developed technologies exist for repair of the absorber layer, no viable strategy for the repair of ML coating defects has been identified. In this paper the state-of-the-art in ML deposition technology, optical inspection of EUVL mask blank defects and candidate absorber patterning approaches are reviewed

Tomographic extreme-ultraviolet spectrographs: TESS.

Science.gov (United States)

Cotton, D M; Stephan, A; Cook, T; Vickers, J; Taylor, V; Chakrabarti, S

2000-08-01

We describe the system of Tomographic Extreme Ultraviolet (EUV) SpectrographS (TESS) that are the primary instruments for the Tomographic Experiment using Radiative Recombinative Ionospheric EUV and Radio Sources (TERRIERS) satellite. The spectrographs were designed to make high-sensitivity {80 counts/s)/Rayleigh [one Rayleigh is equivalent to 10(6) photons/(4pi str cm(2)s)}, line-of-sight measurements of the oi 135.6- and 91.1-nm emissions suitable for tomographic inversion. The system consists of five spectrographs, four identical nightglow instruments (for redundancy and added sensitivity), and one instrument with a smaller aperture to reduce sensitivity and increase spectral resolution for daytime operation. Each instrument has a bandpass of 80-140 nm with approximately 2- and 1-nm resolution for the night and day instruments, respectively. They utilize microchannel-plate-based two-dimensional imaging detectors with wedge-and-strip anode readouts. The instruments were designed, fabricated, and calibrated at Boston University, and the TERRIERS satellite was launched on 18 May 1999 from Vandenberg Air Force Base, California.

Near-infrared oxygen airglow from the Venus nightside

Science.gov (United States)

Crisp, D.; Meadows, V. S.; Allen, D. A.; Bezard, B.; Debergh, C.; Maillard, J.-P.

1992-01-01

Groundbased imaging and spectroscopic observations of Venus reveal intense near-infrared oxygen airglow emission from the upper atmosphere and provide new constraints on the oxygen photochemistry and dynamics near the mesopause (approximately 100 km). Atomic oxygen is produced by the Photolysis of CO2 on the dayside of Venus. These atoms are transported by the general circulation, and eventually recombine to form molecular oxygen. Because this recombination reaction is exothermic, many of these molecules are created in an excited state known as O2(delta-1). The airglow is produced as these molecules emit a photon and return to their ground state. New imaging and spectroscopic observations acquired during the summer and fall of 1991 show unexpected spatial and temporal variations in the O2(delta-1) airglow. The implications of these observations for the composition and general circulation of the upper venusian atmosphere are not yet understood but they provide important new constraints on comprehensive dynamical and chemical models of the upper mesosphere and lower thermosphere of Venus.

Productino of KSR-III Airglow Photometers to Measure MUV Airglows of the Upper Atmosphere Above the Korean Peninsular

Directory of Open Access Journals (Sweden)

T. H. Oh

2002-12-01

Full Text Available We have constructed two flight models of airglow photometer system (AGP to be onboard Korea Sounding Rocket-III (KSR-III for detection of MUV dayglow above the Korean peninsular. The AGP system is designed to detect dayglow emissions of OI 2972 Å, N_2 VK (0,6 2780Å, N_2 2PG 3150Å and background 3070Å toward the horizon at altitudes between 100 km and 300 km. The AGP system consists of a photometer body, a baffle, an electronic control unit and a battery unit. The MUV dayglow emissions enter through a narrow band interference filter and focusing lens of the photometer, which contains an ultraviolet sensitive photomultiplier tube. The photometer is equipped with an in-flight calibration light source on a circular plane that will rotate at the rocket's apogee. A baffle tube is installed at the entry of the photometer in order to block strong scattering lights from the lower atmosphere. We have carried out laboratory measurements of sensitivity and in-flight calibration light source for the AGP flight models. Although absolute sensitivities of the AGP flight models could not be determined in the country, relative sensitivities among channels are well measured so that observation data during rocket flight in the future can be analyzed with confidence.

Characteristics of extreme ultraviolet emission from high-Z plasmas

International Nuclear Information System (INIS)

Ohashi, H.; Higashiguchi, T.; Suzuki, Y.; Kawasaki, M.; Suzuki, C.; Tomita, K.; Nishikino, M.; Fujioka, S.; Endo, A.; Li, B.; Otsuka, T.; Dunne, P.; O'Sullivan, G.

2016-01-01

We demonstrate the extreme ultraviolet (EUV) and soft x-ray sources in the 2 to 7 nm spectral region related to the beyond EUV (BEUV) question at 6.x nm and the water window source based on laser-produced high-Z plasmas. Resonance emission from multiply charged ions merges to produce intense unresolved transition arrays (UTAs), extending below the carbon K edge (4.37 nm). An outline of a microscope design for single-shot live cell imaging is proposed based on high-Z plasma UTA source, coupled to multilayer mirror optics. (paper)

Characteristics of extreme ultraviolet emission from high-Z plasmas

Science.gov (United States)

Ohashi, H.; Higashiguchi, T.; Suzuki, Y.; Kawasaki, M.; Suzuki, C.; Tomita, K.; Nishikino, M.; Fujioka, S.; Endo, A.; Li, B.; Otsuka, T.; Dunne, P.; O'Sullivan, G.

2016-03-01

We demonstrate the extreme ultraviolet (EUV) and soft x-ray sources in the 2 to 7 nm spectral region related to the beyond EUV (BEUV) question at 6.x nm and the water window source based on laser-produced high-Z plasmas. Resonance emission from multiply charged ions merges to produce intense unresolved transition arrays (UTAs), extending below the carbon K edge (4.37 nm). An outline of a microscope design for single-shot live cell imaging is proposed based on high-Z plasma UTA source, coupled to multilayer mirror optics.

Production of narrowband tunable extreme-ultraviolet radiation by noncollinear resonance-enhanced four-wave mixing

NARCIS (Netherlands)

Hannemann, S.; Hollenstein, U.; van Duijn, E.J.; Ubachs, W.M.G.

2005-01-01

Fourier-transform-limited extreme-ultraviolet (XUV) radiation (bandwidth ≲300 MHz) tunable around 91 nm is produced by use of two-photon resonance-enhanced four-wave mixing on the Kr resonance at 94 093 cm

Extreme Ultraviolet Imaging of Electron Heated Targets in Petawatt Laser Experiments

International Nuclear Information System (INIS)

Ma, T.; MacPhee, A.; Key, M.; Akli, K.; Mackinnon, A.; Chen, C.; Barbee, T.; Freeman, R.; King, J.; Link, A.; Offermann, D.; Ovchinnikov, V.; Patel, P.; Stephens, R.; VanWoerkom, L.; Zhang, B.; Beg, F.

2007-01-01

The study of the transport of electrons, and the flow of energy into a solid target or dense plasma, is instrumental in the development of fast ignition inertial confinement fusion. An extreme ultraviolet (XUV) imaging diagnostic at 256 eV and 68 eV provides information about heating and energy deposition within petawatt laser-irradiated targets. XUV images of several irradiated solid targets are presented

76 FR 37650 - Safety Zone; 4th of July Festival Berkeley Marina Fireworks Display Berkeley, CA

Science.gov (United States)

2011-06-28

...-AA00 Safety Zone; 4th of July Festival Berkeley Marina Fireworks Display Berkeley, CA AGENCY: Coast... the 4th of July Festival Berkeley Marina Fireworks Display. Unauthorized persons or vessels are... display. Background and Purpose The City of Berkeley Marina will sponsor the 4th of July Festival Berkeley...

Extreme-ultraviolet wavelength and lifetime measurements in highly ionized krypton

CERN Document Server

Kukla, K W; Vogt, C M V; Berry, H G; Dunford, R W; Curtis, L J; Cheng, S

2005-01-01

We have studied the spectrum of highly ionized krypton in the extreme-ultraviolet wavelength region (50-300 Aa), using beam-foil excitation of fast krypton ions at the Argonne ATLAS accelerator facility. We report measurements of transition wavelengths and excited-state lifetimes for n=2 states in the lithiumlike, berylliumlike, and boronlike ions, Kr/sup 31+,32+,33+/. Excited state lifetimes ranging from 10 ps to 3 ns were measured by acquiring time- of-flight-delayed spectra with a position-sensitive multichannel detector.

Ionospheric Remote Sensing using GPS Radio Occultation and Ultraviolet Photometry aboard the ISS

Science.gov (United States)

Budzien, S. A.; Powell, S. P.; O'Hanlon, B.; Humphreys, T.; Bishop, R. L.; Stephan, A. W.; Gross, J.; Chakrabarti, S.

2017-12-01

The GPS Radio Occultation and Ultraviolet Photometer Co-located (GROUP-C) experiment launched to the International Space Station (ISS) on February 19, 2017 as part of the Space Test Program Houston #5 payload (STP-H5). After early orbit testing, GROUP-C began routine science operations in late April. GROUP-C includes a high-sensitivity far-ultraviolet photometer measuring horizontal nighttime ionospheric gradients and an advanced software-defined GPS receiver providing ionospheric electron density profiles, scintillation measurements, and lower atmosphere profiles. GROUP-C and a companion experiment, the Limb-Imaging Ionospheric and Thermospheric Extreme-Ultraviolet Spectrograph (LITES), offer a unique capability to study spatial and temporal variability of the thermosphere and ionosphere using multi-sensor approaches, including ionospheric tomography. Data are collected continuously across low- and mid-latitudes as the ISS orbit precesses through all local times every 60 days. The GROUP-C GPS sensor routinely collects dual-frequency GPS occultations, makes targeted raw signal captures of GPS and Galileo occultations, and includes multiple antennas to characterize multipath in the ISS environment. The UV photometer measures the 135.6 nm ionospheric recombination airglow emision along the nightside orbital track. We present the first analysis of ionospheric observations, discuss the challenges and opportunities of remote sensing from the ISS platform, and explore how these new data help address questions regarding the complex and dynamic features of the low and middle latitude ionosphere-thermosphere relevant to the upcoming GOLD and ICON missions.

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

Energy Technology Data Exchange (ETDEWEB)

Plötzing, M.; Adam, R., E-mail: r.adam@fz-juelich.de; Weier, C.; Plucinski, L.; Schneider, C. M. [Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-6), 52425 Jülich (Germany); Eich, S.; Emmerich, S.; Rollinger, M.; Aeschlimann, M. [University of Kaiserslautern and Research Center OPTIMAS, 67663 Kaiserslautern (Germany); Mathias, S. [Georg-August-Universität Göttingen, I. Physikalisches Institut, 37077 Göttingen (Germany)

2016-04-15

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

Solar Energy Deposition Rates in the Mesosphere Derived from Airglow Measurements: Implications for the Ozone Model Deficit Problem

Science.gov (United States)

Mlynczak, Martin G.; Garcia, Rolando R.; Roble, Raymond G.; Hagan, Maura

2000-01-01

We derive rates of energy deposition in the mesosphere due to the absorption of solar ultraviolet radiation by ozone. The rates are derived directly from measurements of the 1.27-microns oxygen dayglow emission, independent of knowledge of the ozone abundance, the ozone absorption cross sections, and the ultraviolet solar irradiance in the ozone Hartley band. Fifty-six months of airglow data taken between 1982 and 1986 by the near-infrared spectrometer on the Solar-Mesosphere Explorer satellite are analyzed. The energy deposition rates exhibit altitude-dependent annual and semi-annual variations. We also find a positive correlation between temperatures and energy deposition rates near 90 km at low latitudes. This correlation is largely due to the semiannual oscillation in temperature and ozone and is consistent with model calculations. There is also a suggestion of possible tidal enhancement of this correlation based on recent theoretical and observational analyses. The airglow-derived rates of energy deposition are then compared with those computed by multidimensional numerical models. The observed and modeled deposition rates typically agree to within 20%. This agreement in energy deposition rates implies the same agreement exists between measured and modeled ozone volume mixing ratios in the mesosphere. Only in the upper mesosphere at midlatitudes during winter do we derive energy deposition rates (and hence ozone mixing ratios) consistently and significantly larger than the model calculations. This result is contrary to previous studies that have shown a large model deficit in the ozone abundance throughout the mesosphere. The climatology of solar energy deposition and heating presented in this paper is available to the community at the Middle Atmosphere Energy Budget Project web site at http://heat-budget.gats-inc.com.

Application of tomographic inversion in studying airglow in the mesopause region

Directory of Open Access Journals (Sweden)

T. Nygrén

Full Text Available It is pointed out that observations of periodic nightglow structures give excellent information on atmospheric gravity waves in the mesosphere and lower thermosphere. The periods, the horizontal wavelengths and the phase speeds of the waves can be determined from airglow images and, using several cameras, the approximate altitude of the luminous layer can also be determined by triangulation. In this paper the possibility of applying tomographic methods for reconstructing the airglow structures is investigated using numerical simulations. A ground-based chain of cameras is assumed, two-dimensional airglow models in the vertical plane above the chain are constructed, and simulated data are calculated by integrating the models along a great number of rays with different elevation angles for each camera. After addition of random noise, these data are then inverted to obtain reconstructions of the models. A tomographic analysis package originally designed for satellite radiotomography is used in the inversion. The package is based on a formulation of stochastic inversion which allows the input of a priori information to the solver in terms of regularization variances. The reconstruction is carried out in two stages. In the first inversion, constant regularization variances are used within a wide altitude range. The results are used in determining the approximate altitude range of the airglow structures. Then, in the second inversion, constant non-zero regularization variances are used inside this region and zero variances outside it. With this method reliable reconstructions of the models are obtained. The number of cameras as well as their separations are varied in order to find out the limitations of the method.

Key words. Tomography · Airglow · Mesopause · Gravity waves

Low-defect reflective mask blanks for extreme ultraviolet lithography

International Nuclear Information System (INIS)

Burkhart, S C; Cerjarn, C; Kearney, P; Mirkarimi, P; Ray-Chaudhuri, A; Walton, C.

1999-01-01

Extreme Ultraviolet Lithgraphy (EUVL) is an emerging technology for fabrication of sub-100 nm feature sizes on silicon, following the SIA road map well into the 21st century. The specific EUVL system described is a scanned, projection lithography system with a 4:1 reduction, using a laser plasma EUV source. The mask and all of the system optics are reflective, multilayer mirrors which function in the extreme ultraviolet at 13.4 nm wavelength. Since the masks are imaged to the wafer exposure plane, mask defects greater than 80% of the exposure plane CD (for 4:1 reduction) will in many cases render the mask useless, whereas intervening optics can have defects which are not a printing problem. For the 100 nm node, we must reduce defects to less than 0.01/cm ampersand sup2; at sign 80nm or larger to obtain acceptable mask production yields. We have succeeded in reducing the defects to less than 0.1/cm ampersand sup2; for defects larger than 130 nm detected by visible light inspection tools, however our program goal is to achieve 0.01/cm ampersand sup2; in the near future. More importantly though, we plan to have a detailed understanding of defect origination and the effect on multilayer growth in order to mitigate defects below the 10 -2 /cm ampersand sup2; level on the next generation of mask blank deposition systems. In this paper we will discuss issues and results from the ion-beam multilayer deposition tool, details of the defect detection and characterization facility, and progress on defect printability modeling

Rabi oscillations in extreme ultraviolet ionization of atomic argon

Science.gov (United States)

Flögel, Martin; Durá, Judith; Schütte, Bernd; Ivanov, Misha; Rouzée, Arnaud; Vrakking, Marc J. J.

2017-02-01

We demonstrate Rabi oscillations in nonlinear ionization of argon by an intense femtosecond extreme ultraviolet (XUV) laser field produced by high-harmonic generation. We monitor the formation of A r2 + as a function of the time delay between the XUV pulse and an additional near-infrared (NIR) femtosecond laser pulse, and show that the population of an A r+* intermediate resonance exhibits strong modulations both due to an NIR laser-induced Stark shift and XUV-induced Rabi cycling between the ground state of A r+ and the A r+* excited state. Our experiment represents a direct experimental observation of a Rabi-cycling process in the XUV regime.

Operation of a free-electron laser from the extreme ultraviolet to the water window

Science.gov (United States)

Ackermann, W.; Asova, G.; Ayvazyan, V.; Azima, A.; Baboi, N.; Bähr, J.; Balandin, V.; Beutner, B.; Brandt, A.; Bolzmann, A.; Brinkmann, R.; Brovko, O. I.; Castellano, M.; Castro, P.; Catani, L.; Chiadroni, E.; Choroba, S.; Cianchi, A.; Costello, J. T.; Cubaynes, D.; Dardis, J.; Decking, W.; Delsim-Hashemi, H.; Delserieys, A.; di Pirro, G.; Dohlus, M.; Düsterer, S.; Eckhardt, A.; Edwards, H. T.; Faatz, B.; Feldhaus, J.; Flöttmann, K.; Frisch, J.; Fröhlich, L.; Garvey, T.; Gensch, U.; Gerth, Ch.; Görler, M.; Golubeva, N.; Grabosch, H.-J.; Grecki, M.; Grimm, O.; Hacker, K.; Hahn, U.; Han, J. H.; Honkavaara, K.; Hott, T.; Hüning, M.; Ivanisenko, Y.; Jaeschke, E.; Jalmuzna, W.; Jezynski, T.; Kammering, R.; Katalev, V.; Kavanagh, K.; Kennedy, E. T.; Khodyachykh, S.; Klose, K.; Kocharyan, V.; Körfer, M.; Kollewe, M.; Koprek, W.; Korepanov, S.; Kostin, D.; Krassilnikov, M.; Kube, G.; Kuhlmann, M.; Lewis, C. L. S.; Lilje, L.; Limberg, T.; Lipka, D.; Löhl, F.; Luna, H.; Luong, M.; Martins, M.; Meyer, M.; Michelato, P.; Miltchev, V.; Möller, W. D.; Monaco, L.; Müller, W. F. O.; Napieralski, O.; Napoly, O.; Nicolosi, P.; Nölle, D.; Nuñez, T.; Oppelt, A.; Pagani, C.; Paparella, R.; Pchalek, N.; Pedregosa-Gutierrez, J.; Petersen, B.; Petrosyan, B.; Petrosyan, G.; Petrosyan, L.; Pflüger, J.; Plönjes, E.; Poletto, L.; Pozniak, K.; Prat, E.; Proch, D.; Pucyk, P.; Radcliffe, P.; Redlin, H.; Rehlich, K.; Richter, M.; Roehrs, M.; Roensch, J.; Romaniuk, R.; Ross, M.; Rossbach, J.; Rybnikov, V.; Sachwitz, M.; Saldin, E. L.; Sandner, W.; Schlarb, H.; Schmidt, B.; Schmitz, M.; Schmüser, P.; Schneider, J. R.; Schneidmiller, E. A.; Schnepp, S.; Schreiber, S.; Seidel, M.; Sertore, D.; Shabunov, A. V.; Simon, C.; Simrock, S.; Sombrowski, E.; Sorokin, A. A.; Spanknebel, P.; Spesyvtsev, R.; Staykov, L.; Steffen, B.; Stephan, F.; Stulle, F.; Thom, H.; Tiedtke, K.; Tischer, M.; Toleikis, S.; Treusch, R.; Trines, D.; Tsakov, I.; Vogel, E.; Weiland, T.; Weise, H.; Wellhöfer, M.; Wendt, M.; Will, I.; Winter, A.; Wittenburg, K.; Wurth, W.; Yeates, P.; Yurkov, M. V.; Zagorodnov, I.; Zapfe, K.

2007-06-01

We report results on the performance of a free-electron laser operating at a wavelength of 13.7 nm where unprecedented peak and average powers for a coherent extreme-ultraviolet radiation source have been measured. In the saturation regime, the peak energy approached 170 µJ for individual pulses, and the average energy per pulse reached 70 µJ. The pulse duration was in the region of 10 fs, and peak powers of 10 GW were achieved. At a pulse repetition frequency of 700 pulses per second, the average extreme-ultraviolet power reached 20 mW. The output beam also contained a significant contribution from odd harmonics of approximately 0.6% and 0.03% for the 3rd (4.6 nm) and the 5th (2.75 nm) harmonics, respectively. At 2.75 nm the 5th harmonic of the radiation reaches deep into the water window, a wavelength range that is crucially important for the investigation of biological samples.

Ion beam sputtered aluminum based multilayer mirrors for extreme ultraviolet solar imaging

Energy Technology Data Exchange (ETDEWEB)

Ziani, A. [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex France (France); Centre National d’Etudes Spatiales (CNES), 18 Avenue E. Belin, 31401 Toulouse (France); Delmotte, F., E-mail: Franck.Delmotte@InstitutOptique.fr [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex France (France); Le Paven-Thivet, C. [Institut d' Electronique et de Télécommunications de Rennes (IETR) UMR-CNRS 6164, Université de Rennes 1, UEB, IUT Saint Brieuc, 18 rue Henri Wallon, 22004 Saint Brieuc cedex France (France); Meltchakov, E.; Jérome, A. [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex France (France); Roulliay, M. [Institut des Sciences Moléculaires d’Orsay UMR 8214, Univ Paris Sud, 91405 Orsay France (France); Bridou, F. [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex France (France); Gasc, K. [Centre National d’Etudes Spatiales (CNES), 18 Avenue E. Belin, 31401 Toulouse (France)

2014-02-03

In this paper, we report on the design, synthesis and characterization of extreme ultraviolet interferential mirrors for solar imaging applications in the spectral range 17 nm–34 nm. This research is carried out in the context of the preparation of the European Space Agency Solar Orbiter mission. The purpose of this study consists in optimizing the deposition of Al-based multilayers by ion beam sputtering according to several parameters such as the ion beam current and the sputtering angle. After optimization of Al thin films, several kinds of Al-based multilayer mirrors have been compared. We have deposited and characterized bi-material and also tri-material periodic multilayers: aluminum/molybdenum [Al/Mo], aluminum/molybdenum/boron carbide [Al/Mo/B{sub 4}C] and aluminum/molybdenum/silicon carbide [Al/Mo/SiC]. Best experimental results have been obtained on Al/Mo/SiC samples: we have measured reflectivity up to 48% at 17.3 nm and 27.5% at 28.2 nm on a synchrotron radiation source. - Highlights: • Design and synthesis of extreme ultraviolet interferential mirrors. • Optimization of aluminum thin films by adjusting several deposition parameters. • Comparison of results obtained with different types of Al-based multilayer mirrors. • Reflectivity up to 48% at 17.3 nm on a synchrotron radiation source.

Ion beam sputtered aluminum based multilayer mirrors for extreme ultraviolet solar imaging

International Nuclear Information System (INIS)

Ziani, A.; Delmotte, F.; Le Paven-Thivet, C.; Meltchakov, E.; Jérome, A.; Roulliay, M.; Bridou, F.; Gasc, K.

2014-01-01

In this paper, we report on the design, synthesis and characterization of extreme ultraviolet interferential mirrors for solar imaging applications in the spectral range 17 nm–34 nm. This research is carried out in the context of the preparation of the European Space Agency Solar Orbiter mission. The purpose of this study consists in optimizing the deposition of Al-based multilayers by ion beam sputtering according to several parameters such as the ion beam current and the sputtering angle. After optimization of Al thin films, several kinds of Al-based multilayer mirrors have been compared. We have deposited and characterized bi-material and also tri-material periodic multilayers: aluminum/molybdenum [Al/Mo], aluminum/molybdenum/boron carbide [Al/Mo/B 4 C] and aluminum/molybdenum/silicon carbide [Al/Mo/SiC]. Best experimental results have been obtained on Al/Mo/SiC samples: we have measured reflectivity up to 48% at 17.3 nm and 27.5% at 28.2 nm on a synchrotron radiation source. - Highlights: • Design and synthesis of extreme ultraviolet interferential mirrors. • Optimization of aluminum thin films by adjusting several deposition parameters. • Comparison of results obtained with different types of Al-based multilayer mirrors. • Reflectivity up to 48% at 17.3 nm on a synchrotron radiation source

Midnight latitude-altitude distribution of 630 nm airglow in the Asian sector measured with FORMOSAT-2/ISUAL

Science.gov (United States)

Adachi, Toru; Yamaoka, Masashi; Yamamoto, Mamoru; Otsuka, Yuichi; Liu, Huixin; Hsiao, Chun-Chieh; Chen, Alfred B.; Hsu, Rue-Ron

2010-09-01

The Imager for Sprites and Upper Atmospheric Lightning (ISUAL) payload on board the FORMOSAT-2 satellite carried out the first limb imaging observation of 630 nm airglow for the purpose of studying physical processes in the F region ionosphere. For a total of 14 nights in 2006-2008, ISUAL scanned the midnight latitude-altitude distribution of 630 nm airglow in the Asian sector. On two nights of relatively active conditions (ΣKp = 26, 30+) we found several bright airglow regions, which were highly variable each night in terms of luminosity and location. In relatively quiet conditions (ΣKp = 4-20) near May/June we found two bright regions which were stably located in the midlatitude region of 40°S-10°S (50°S-20°S magnetic latitude (MLAT)) and in the equatorial region of 0°-10°N (10°S-0° MLAT). On one of the quiet nights, FORMOSAT-3/COSMIC and CHAMP simultaneously measured the plasma density in the same region where ISUAL observed airglow. The plasma density data generally show good agreement, suggesting that plasma enhancements were the primary source of these two bright airglow regions. From detailed comparison with past studies we explain that the airglow in the equatorial region was due to the midnight brightness wave produced in association with the midnight temperature maximum, while that in the midlatitude region was due to the typical plasma distribution usually formed in the midnight sector. The fact that the equatorial airglow was much brighter than the midlatitude airglow and was observed on most nights during the campaign period strongly suggests the importance of further studies on the MTM/MBW phenomenology, which is not well reproduced in the current general circulation model.

OH Airglow and Equatorial Variations Observed by ISUAL Instrument on Board the FORMOSAT 2 Satellite

Directory of Open Access Journals (Sweden)

Jan-Bai Nee

2010-01-01

Full Text Available OH airglow observed by the ISUAL (Imager of Sprites and Upper Atmospheric Lightning instrument on board the FORMOSAT 2 satellite is reported in this paper. The satellite is sun-synchronous and it returns to the same orbit at the same local time daily. By using this property, we can study the upper atmosphere in detail. With a CCD camera, ISUAL has measured the emission layers of OH Meinel band at 630 nm for several two-week periods in 2004 and 2007 in equatorial regions. ISUAL images are snapshots of the atmosphere 250 km (height ¡_ 1200 km (horizontal distance. These images of OH airglow are analyzed to derive its peak height and latitudinal variations. ISUAL observation is unique in its capability of continuous observation of the upper atmosphere as the satellite travels from south to north along a specific orbit. However, 630 nm filter also measured O(1D at 200 km, and there are interferences between O(1D and OH airglows as as observed from a distance in space. We have studied the overlap of two airglows by simulations, and our final analyses show that OH airglow can be correctly derived with its average peak height of 89 ¡_ 2.1 km usually lying within ¡_10¢X latitude about the equator. ISUAL data reveal detailed structures of equatorial OH airglow such as the existences of a few secondary maxima within the equatorial regions, and the oscillations of the peak latitudes. These results are discussed and compared with previous reports.

Berkeley Conference

Energy Technology Data Exchange (ETDEWEB)

Anon.

1986-10-15

To a regular observer at annual international meetings, progress in particle physics from one year to the next sometimes might seem ponderously slow. But shift the timescale and the result is startling. Opening his summary of the 1986 International Conference on High Energy Physics, held in Berkeley, California, from 16-23 July, Steve Weinberg first recalled the 1966 Conference, also held in Berkeley. Then the preoccupations were current algebra, hadron resonances and the interpretation of scattering in terms of Regge poles, and the theory of weak interactions. Physics certainly has moved.

Berkeley Conference

International Nuclear Information System (INIS)

Anon.

1986-01-01

To a regular observer at annual international meetings, progress in particle physics from one year to the next sometimes might seem ponderously slow. But shift the timescale and the result is startling. Opening his summary of the 1986 International Conference on High Energy Physics, held in Berkeley, California, from 16-23 July, Steve Weinberg first recalled the 1966 Conference, also held in Berkeley. Then the preoccupations were current algebra, hadron resonances and the interpretation of scattering in terms of Regge poles, and the theory of weak interactions. Physics certainly has moved

Night Airglow Observations from Orbiting Spacecraft Compared with Measurements from Rockets.

Science.gov (United States)

Koomen, M J; Gulledge, I S; Packer, D M; Tousey, R

1963-06-07

A luminous band around the night-time horizon, observed from orbiting capsules by J. H. Glenn and M. S. Carpenter, and identified as the horizon enhancement of the night airglow, is detected regularly in rocket-borne studies of night airglow. Values of luminance and dip angle of this band derived from Carpenter's observations agree remarkably well with values obtained from rocket data. The rocket results, however, do not support Carpenter's observation that the emission which he saw was largely the atomic oxygen line at 5577 A, but assign the principal luminosity to the green continuum.

OBSERVATIONS OF FIVE-MINUTE SOLAR OSCILLATIONS IN THE CORONA USING THE EXTREME ULTRAVIOLET SPECTROPHOTOMETER (ESP) ON BOARD THE SOLAR DYNAMICS OBSERVATORY EXTREME ULTRAVIOLET VARIABILITY EXPERIMENT (SDO/EVE)

International Nuclear Information System (INIS)

Didkovsky, L.; Judge, D.; Wieman, S.; Kosovichev, A. G.; Woods, T.

2011-01-01

We report on the detection of oscillations in the corona in the frequency range corresponding to five-minute acoustic modes of the Sun. The oscillations have been observed using soft X-ray measurements from the Extreme Ultraviolet Spectrophotometer (ESP) of the Extreme Ultraviolet Variability Experiment on board the Solar Dynamics Observatory. The ESP zeroth-order channel observes the Sun as a star without spatial resolution in the wavelength range of 0.1-7.0 nm (the energy range is 0.18-12.4 keV). The amplitude spectrum of the oscillations calculated from six-day time series shows a significant increase in the frequency range of 2-4 mHz. We interpret this increase as a response of the corona to solar acoustic (p) modes and attempt to identify p-mode frequencies among the strongest peaks. Due to strong variability of the amplitudes and frequencies of the five-minute oscillations in the corona, we study how the spectrum from two adjacent six-day time series combined together affects the number of peaks associated with the p-mode frequencies and their amplitudes. This study shows that five-minute oscillations of the Sun can be observed in the corona in variations of the soft X-ray emission. Further investigations of these oscillations may improve our understanding of the interaction of the oscillation modes with the solar atmosphere, and the interior-corona coupling, in general.

A NOISE ADAPTIVE FUZZY EQUALIZATION METHOD FOR PROCESSING SOLAR EXTREME ULTRAVIOLET IMAGES

Energy Technology Data Exchange (ETDEWEB)

Druckmueller, M., E-mail: druckmuller@fme.vutbr.cz [Institute of Mathematics, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2, 616 69 Brno (Czech Republic)

2013-08-15

A new image enhancement tool ideally suited for the visualization of fine structures in extreme ultraviolet images of the corona is presented in this paper. The Noise Adaptive Fuzzy Equalization method is particularly suited for the exceptionally high dynamic range images from the Atmospheric Imaging Assembly instrument on the Solar Dynamics Observatory. This method produces artifact-free images and gives significantly better results than methods based on convolution or Fourier transform which are often used for that purpose.

Extreme ultraviolet spectroscopy of highly charged argon ions at the Berlin EBIT

International Nuclear Information System (INIS)

Biedermann, C; Radtke, R; Fussmann, G; Allen, F I

2007-01-01

Extreme ultraviolet radiation from highly charged argon was investigated at the Berlin Electron Beam Ion Trap with a 2 m grazing incidence spectrometer. Lines in the wavelength range 150 to 660 A originating from C-like Ar 12+ to Li-like Ar 15+ ions have been identified and are compared with database information from solar line lists and predictions. Line ratios for the observed resonance, intercombination and forbidden lines offer important diagnostic capabilities for low density, hot plasmas

Laser waveform control of extreme ultraviolet high harmonics from solids.

Science.gov (United States)

You, Yong Sing; Wu, Mengxi; Yin, Yanchun; Chew, Andrew; Ren, Xiaoming; Gholam-Mirzaei, Shima; Browne, Dana A; Chini, Michael; Chang, Zenghu; Schafer, Kenneth J; Gaarde, Mette B; Ghimire, Shambhu

2017-05-01

Solid-state high-harmonic sources offer the possibility of compact, high-repetition-rate attosecond light emitters. However, the time structure of high harmonics must be characterized at the sub-cycle level. We use strong two-cycle laser pulses to directly control the time-dependent nonlinear current in single-crystal MgO, leading to the generation of extreme ultraviolet harmonics. We find that harmonics are delayed with respect to each other, yielding an atto-chirp, the value of which depends on the laser field strength. Our results provide the foundation for attosecond pulse metrology based on solid-state harmonics and a new approach to studying sub-cycle dynamics in solids.

WINDII airglow observations of wave superposition and the possible association with historical "bright nights"

Science.gov (United States)

Shepherd, G. G.; Cho, Y.-M.

2017-07-01

Longitudinal variations of airglow emission rate are prominent in all midlatitude nighttime O(1S) lower thermospheric data obtained with the Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite (UARS). The pattern generally appears as a combination of zonal waves 1, 2, 3, and 4 whose phases propagate at different rates. Sudden localized enhancements of 2 to 4 days duration are sometimes evident, reaching vertically integrated emission rates of 400 R, a factor of 10 higher than minimum values for the same day. These are found to occur when the four wave components come into the same phase at one longitude. It is shown that these highly localized longitudinal maxima are consistent with the historical phenomena known as "bright nights" in which the surroundings of human dark night observers were seen to be illuminated by this enhanced airglow.Plain Language SummaryFor centuries, going back to the Roman era, people have recorded experiences of brightened skies during the night, called "bright nights." Currently, scientists study airglow, an emission of light from the high atmosphere, 100 km above us. Satellite observations of a green airglow have shown that it consists of waves 1, 2, 3, and 4 around the earth. It happens that when the peaks of the different waves coincide there is an airglow brightening, and this article demonstrates that this event produces a bright night. The modern data are shown to be entirely consistent with the historical observations.

BERKELEY: ALS ring

Energy Technology Data Exchange (ETDEWEB)

Anon.

1993-06-15

Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

BERKELEY: ALS ring

International Nuclear Information System (INIS)

Anon.

1993-01-01

Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

Extreme ultraviolet observations of G191-B2B and the local interstellar medium with the Hopkins Ultraviolet Telescope

Science.gov (United States)

Kimble, Randy A.; Davidsen, Arthur F.; Blair, William P.; Bowers, Charles W.; Van Dyke Dixon, W.; Durrance, Samuel T.; Feldman, Paul D.; Ferguson, Henry C.; Henry, Richard C.; Kriss, Gerard A.

1993-01-01

During the Astro-l mission in 1990 December, the Hopkins Ultraviolet Telescope (HUT) was used to observe the extreme ultraviolet spectrum (415-912 A) of the hot DA white dwarf GI91-B2B. Absorption by neutral helium shortward of the 504 A He I absorption edge is clearly detected in the raw spectrum. Model fits to the observed spectrum require interstellar neutral helium and neutral hydrogen column densities of 1.45 +/- 0.065 x 10 exp 17/sq cm and 1.69 +/- 0.12 x 10 exp 18/sq cm, respectively. Comparison of the neutral columns yields a direct assessment of the ionization state of the local interstellar cloud surrounding the Sun. The neutral hydrogen to helium ratio of 11.6 +/- 1.0 observed by HUT strongly contradicts the widespread view that hydrogen is much more ionized than helium in the local interstellar medium, a view which has motivated some exotic theoretical explanations for the supposed high ionization.

The creation of radiation dominated plasmas using laboratory extreme ultra-violet lasers

Science.gov (United States)

Tallents, G. J.; Wilson, S.; West, A.; Aslanyan, V.; Lolley, J.; Rossall, A. K.

2017-06-01

Ionization in experiments where solid targets are irradiated by high irradiance extreme ultra-violet (EUV) lasers is examined. Free electron degeneracy effects on ionization in the presence of a high EUV flux of radiation is shown to be important. Overlap of the physics of such plasmas with plasma material under compression in indirect inertial fusion is explored. The design of the focusing optics needed to achieve high irradiance (up to 1014 Wcm-2) using an EUV capillary laser is presented.

Extreme ultraviolet patterning of tin-oxo cages

Science.gov (United States)

Haitjema, Jarich; Zhang, Yu; Vockenhuber, Michaela; Kazazis, Dimitrios; Ekinci, Yasin; Brouwer, Albert M.

2017-07-01

We report on the extreme ultraviolet (EUV) patterning performance of tin-oxo cages. These cage molecules were already known to function as a negative tone photoresist for EUV radiation, but in this work, we significantly optimized their performance. Our results show that sensitivity and resolution are only meaningful photoresist parameters if the process conditions are optimized. We focus on contrast curves of the materials using large area EUV exposures and patterning of the cages using EUV interference lithography. It is shown that baking steps, such as postexposure baking, can significantly affect both the sensitivity and contrast in the open-frame experiments as well as the patterning experiments. A layer thickness increase reduced the necessary dose to induce a solubility change but decreased the patterning quality. The patterning experiments were affected by minor changes in processing conditions such as an increased rinsing time. In addition, we show that the anions of the cage can influence the sensitivity and quality of the patterning, probably through their effect on physical properties of the materials.

Characteristics of equatorial gravity waves derived from mesospheric airglow imaging observations

Directory of Open Access Journals (Sweden)

S. Suzuki

2009-04-01

Full Text Available We present the characteristics of small-scale (<100 km gravity waves in the equatorial mesopause region derived from OH airglow imaging observations at Kototabang (100.3° E, 0.2° S, Indonesia, from 2002 to 2005. We adopted a method that could automatically detect gravity waves in the airglow images using two-dimensional cross power spectra of gravity waves. The propagation directions of the waves were likely controlled by zonal filtering due to stratospheric mean winds that show a quasi-biennial oscillation (QBO and the presence of many wave sources in the troposphere.

EDITORIAL: Extreme Ultraviolet Light Sources for Semiconductor Manufacturing

Science.gov (United States)

Attwood, David

2004-12-01

filaments, for both Xe and Sn. The embodiment of electrical discharge plasmas and laser-produced plasmas into commercially available EUV sources, with EUV powers that project to suitable levels, is presented in the fifth paper by Uwe Stamm of XTREME Technologies in Göttingen. For discharge produced plasmas, thermal loading and electrode erosion are significant issues. Vladimir Borisov and his colleagues, at the Troitsk Institute outside Moscow, address these issues and provide novel ideas for the multiplexing of several discharge plasmas feeding a single optical system. Igor Fomenkov and his colleagues at Cymer in San Diego describe issues associated with a dense plasma focus pinch, including a comparison of operations with both positive and negative polarity. In the eighth paper, Malcolm McGeoch of Plex in Massachusetts provides a theoretical description of the vaporization and ionization of spherical tin droplets in discharge plasma. Together this cluster of papers provides a broad review of the current status of high power EUV plasma sources for semiconductor manufacturing. This very current topic, of intense interest worldwide, is considered further in a book [4] of collected papers to become available in mid-2005. Additionally, a special journal issue emphasizing coherent EUV sources, albeit at lower average powers, is soon to appear [5]. References [1] http://public.itrsr.net [2] Attwood D 2000 Soft X-Rays and Extreme Ultraviolet Radiation: Principles and Applications (Cambridge: Cambridge University Press) www.coe.Berkeley.edu/AST/sxreuv [3] Moore G E 1965 Cramming More Components onto Integrated Circuits Electronics Magazine 114 Moore G E 1995 Lithography and the Future of Moore's Law SPIE 243 2 [4] Bakshi V ed 2005 EUV Sources for Lithography (Bellingham WA:SPIE) at press [5] IEEE J. Special Topics in Quantum Electronics, Short Wavelength and EUV Lasers 10 Dec 2004 at press

Method for the protection of extreme ultraviolet lithography optics

Science.gov (United States)

Grunow, Philip A.; Clift, Wayne M.; Klebanoff, Leonard E.

2010-06-22

A coating for the protection of optical surfaces exposed to a high energy erosive plasma. A gas that can be decomposed by the high energy plasma, such as the xenon plasma used for extreme ultraviolet lithography (EUVL), is injected into the EUVL machine. The decomposition products coat the optical surfaces with a protective coating maintained at less than about 100 .ANG. thick by periodic injections of the gas. Gases that can be used include hydrocarbon gases, particularly methane, PH.sub.3 and H.sub.2S. The use of PH.sub.3 and H.sub.2S is particularly advantageous since films of the plasma-induced decomposition products S and P cannot grow to greater than 10 .ANG. thick in a vacuum atmosphere such as found in an EUVL machine.

Absolute measurement of undulator radiation in the extreme ultraviolet

International Nuclear Information System (INIS)

Maezawa, H.; Kitamura, H.; Sasaki, T.; Mitani, S.; Osaka City Univ.; Suzuki, Y.; Kanamori, H.; Tamamushi, S.; Tokyo Univ.; Mikuni, A.; Tokyo Univ., Tanashi

1983-01-01

The spectral brightness of undulator radiation emitted by the model PMU-1 incorporated in the SOR-RING, the dedicated synchrotron radiation source in Tokyo, has been studied in the extreme ultraviolet region from 21.6 to 72.9 eV as a function of the electron energy #betta#, the field parameter K, and the angle of observation THETA in the absolute scale. A series of measurements covering the first and the second harmonic component of undulator radiation was compared with the fundamental formula lambdasub(n)=lambda 0 /2n#betta# 2 (1+K 2 /2+#betta# 2 THETA 2 ), and the effects of finite emittance were studied. The brightness at the first peak was smaller than the theoretical value, while an enhanced second harmonic component was observed. (orig.)

High-efficiency collector design for extreme-ultraviolet and x-ray applications

International Nuclear Information System (INIS)

Zocchi, Fabio E.

2006-01-01

A design of a two-reflection mirror for nested grazing-incidence optics is proposed in which maximum overall reflectivity is achieved by making the two grazing-incidence angles equal for each ray. The design is proposed mainly for application to nonimaging collector optics for extreme-ultraviolet microlithography where the radiation emitted from a hot plasma source needs to be collected and focused on the illuminator optics. For completeness, the design of a double-reflection mirror with equal reflection angles is also briefly outlined for the case of an object at infinity for possible use in x-ray applications

High-efficiency collector design for extreme-ultraviolet and x-ray applications.

Science.gov (United States)

Zocchi, Fabio E

2006-12-10

A design of a two-reflection mirror for nested grazing-incidence optics is proposed in which maximum overall reflectivity is achieved by making the two grazing-incidence angles equal for each ray. The design is proposed mainly for application to nonimaging collector optics for extreme-ultraviolet microlithography where the radiation emitted from a hot plasma source needs to be collected and focused on the illuminator optics. For completeness, the design of a double- reflection mirror with equal reflection angles is also briefly outlined for the case of an object at infinity for possible use in x-ray applications.

Simultaneous Rayleigh lidar and airglow measurements of middle atmospheric waves over low latitudes in India

Science.gov (United States)

Taori, A.; Kamalakar, V.; Raghunath, K.; Rao, S. V. B.; Russell, J. M.

2012-04-01

We utilize simultaneous Rayleigh lidar and mesospheric OH and O2 airglow measurements to identify the dominant and propagating waves within 40-95 km altitude regions over a low latitude station Gadanki (13.8° N, 79.2 °E). It is found that waves with 0.4-0.6 h periodicity are common throughout the altitude range of 40-95 km with significant amplitudes. The ground based temperature measurements with lidar and airglow monitoring are found to compare well with SABER data. With simultaneous Rayleigh lidar (temperature) and mesospheric airglow (emission intensity and temperature) measurements, we estimate the amplitude growth and Krassovsky parameters to characterize the propagation and dissipation of these upward propagating waves.

Optical proximity correction for anamorphic extreme ultraviolet lithography

Science.gov (United States)

Clifford, Chris; Lam, Michael; Raghunathan, Ananthan; Jiang, Fan; Fenger, Germain; Adam, Kostas

2017-10-01

The change from isomorphic to anamorphic optics in high numerical aperture (NA) extreme ultraviolet (EUV) scanners necessitates changes to the mask data preparation flow. The required changes for each step in the mask tape out process are discussed, with a focus on optical proximity correction (OPC). When necessary, solutions to new problems are demonstrated, and verified by rigorous simulation. Additions to the OPC model include accounting for anamorphic effects in the optics, mask electromagnetics, and mask manufacturing. The correction algorithm is updated to include awareness of anamorphic mask geometry for mask rule checking (MRC). OPC verification through process window conditions is enhanced to test different wafer scale mask error ranges in the horizontal and vertical directions. This work will show that existing models and methods can be updated to support anamorphic optics without major changes. Also, the larger mask size in the Y direction can result in better model accuracy, easier OPC convergence, and designs which are more tolerant to mask errors.

New type of discharge-produced plasma source for extreme ultraviolet based on liquid tin jet electrodes

NARCIS (Netherlands)

Koshelev, K.N.; Krivtsun, V.M.; Ivanov, V.; Yakushev, O.; Chekmarev, A.; Koloshnikov, V.; Snegirev, E.; Medvedev, Viacheslav

2012-01-01

A new approach for discharge-produced plasma (DPP) extreme ultraviolet (EUV) sources based on the usage of two liquid metallic alloy jets as discharge electrodes has been proposed and tested. Discharge was ignited using laser ablation of one of the cathode jets. A system with two jet electrodes was

Development of a free-electron laser user facility for the extreme ultraviolet

International Nuclear Information System (INIS)

Newnam, B.E.

1987-01-01

A free-electron laser user facility for scientific experimentation in the extreme ultraviolet is being developed at Los Alamos. A series of laser oscillators and amplifiers, driven by a single, rf linear accelerator, will generate broadly tunable, picosecond-pulse, coherent radiation from 1 nm to 400 nm. The design and output parameters of this facility are described, comparison with synchrotron radiation sources is made, and recent progress in developing the three primary components (electron beam, undulator, and resonator mirrors) is reviewed, and various categories of scientific applications are indicated

Coherence techniques at extreme ultraviolet wavelengths

Energy Technology Data Exchange (ETDEWEB)

Chang, Chang [Univ. of California, Berkeley, CA (United States)

2002-01-01

The renaissance of Extreme Ultraviolet (EUV) and soft x-ray (SXR) optics in recent years is mainly driven by the desire of printing and observing ever smaller features, as in lithography and microscopy. This attribute is complemented by the unique opportunity for element specific identification presented by the large number of atomic resonances, essentially for all materials in this range of photon energies. Together, these have driven the need for new short-wavelength radiation sources (e.g. third generation synchrotron radiation facilities), and novel optical components, that in turn permit new research in areas that have not yet been fully explored. This dissertation is directed towards advancing this new field by contributing to the characterization of spatial coherence properties of undulator radiation and, for the first time, introducing Fourier optical elements to this short-wavelength spectral region. The first experiment in this dissertation uses the Thompson-Wolf two-pinhole method to characterize the spatial coherence properties of the undulator radiation at Beamline 12 of the Advanced Light Source. High spatial coherence EUV radiation is demonstrated with appropriate spatial filtering. The effects of small vertical source size and beamline apertures are observed. The difference in the measured horizontal and vertical coherence profile evokes further theoretical studies on coherence propagation of an EUV undulator beamline. A numerical simulation based on the Huygens-Fresnel principle is performed.

Attosecond extreme ultraviolet generation in cluster by using spatially inhomogeneous field

Energy Technology Data Exchange (ETDEWEB)

Feng, Liqiang, E-mail: lqfeng-lngy@126.com [College of Science, Liaoning University of Technology, Jinzhou, 121000 (China); State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics Chinese Academy of Sciences, Dalian 116023 (China); Liu, Hang [School of Chemical and Environmental Engineering, Liaoning University of Technology, Jinzhou 121000 (China)

2015-01-15

A promising method to generate the attosecond extreme ultraviolet (XUV) sources has been theoretically investigated emerging from the two-dimensional Ar{sup +} cluster driven by the spatially inhomogeneous field. The results show that with the introduction of the Ar{sup +} cluster model, not only the harmonic cutoffs are enhanced, but also the harmonic yields are reinforced. Furthermore, by properly moderating the inhomogeneity as well as the laser parameters of the inhomogeneous field, the harmonic cutoff can be further extended. As a result, three almost linearly polarized XUV pulses with durations of 40 as, 42 as, and 45 as can be obtained.

Hydroxyl (6−2 airglow emission intensity ratios for rotational temperature determination

Directory of Open Access Journals (Sweden)

R. P. Lowe

Full Text Available OH(6–2 Q1/P1 and R1/P1 airglow emission intensity ratios, for rotational states up to j' = 4.5, are measured to be lower than implied by transition probabilities published by various authors including Mies, Langhoff et al. and Turnbull and Lowe. Experimentally determined relative values of j' transitions yield OH(6–2 rotational temperatures 2 K lower than Langhoff et al., 7 K lower than Mies and 13 K lower than Turnbull and Lowe.Key words: Atmospheric composition and structure (airglow and aurora; pressure, density and temperature

Thermal deformation prediction in reticles for extreme ultraviolet lithography based on a measurement-dependent low-order model

NARCIS (Netherlands)

Bikcora, C.; Weiland, S.; Coene, W.M.J.

2014-01-01

In extreme ultraviolet lithography, imaging errors due to thermal deformation of reticles are becoming progressively intolerable as the source power increases. Despite this trend, such errors can be mitigated by adjusting the wafer and reticle stages based on a set of predicted deformation-induced

Spontaneous and artificial direct nanostructuring of solid surface by extreme ultraviolet laser with nanosecond pulses

Czech Academy of Sciences Publication Activity Database

Koláček, Karel; Schmidt, Jiří; Štraus, Jaroslav; Frolov, Oleksandr; Prukner, Václav; Melich, Radek; Psota, Pavel

2016-01-01

Roč. 34, č. 1 (2016), s. 11-22 ISSN 0263-0346 Institutional support: RVO:61389021 Keywords : Extreme ultraviolet (XUV) interferometer * Aspheric interferometer mirrors * Multilayer reflection coating for 46.9 nm * Ar8+ laser application * XUV direct nanostructuring Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.420, year: 2016 http://dx.doi.org/10.1017/S0263034615000786

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

Spin-on-glass coatings for the generation of super-polishedsubstrates for extreme ultraviolet optics

Energy Technology Data Exchange (ETDEWEB)

Salmassi, Farhad; Naulleau, Patrick P.; Gullikson, Eric M.

2005-01-01

Substrates intended for use as extreme ultraviolet (EUV) optics have extremely stringent requirements in terms of finish. These requirements can dramatically increase the cost and fabrication time, especially when non-conventional shapes, such as toroids, are required. Here we present a spin-on-glass resist process capable of generating super-polished parts from inexpensive substrates. The method has been used to render diamond-turned substrates compatible for use as EUV optics. Toroidal diamond-turned optics with starting rms roughness in the 3.3 to 3.7 nm range have been smoothed to the 0.4 to 0.6 nm range. EUV reflectometry characterization of these optics has demonstrated reflectivities of approximately 63%.

Hemispheric Asymmetry in Transition from Equatorial Plasma Bubble to Blob as Deduced from 630.0 nm Airglow Observations at Low Latitudes

Science.gov (United States)

Park, Jaeheung; Martinis, Carlos R.; Luehr, Hermann; Pfaff, Robert F.; Kwak, Young-Sil

2016-01-01

Transitions from depletions to enhancements of 630.0 nm nighttime airglow have been observed at Arecibo. Numerical simulations by Krall et al. (2009) predicted that they should occur only in one hemisphere, which has not yet been confirmed observationally. In this study we investigate the hemispheric conjugacy of the depletion-to-enhancement transition using multiple instruments. We focus on one event observed in the American longitude sector on 22 December 2014: 630.0 nm airglow depletions evolved into enhancements in the Northern Hemisphere while the evolution did not occur in the conjugate location in the Southern Hemisphere. Concurrent plasma density measured by low Earth orbit (LEO) satellites and 777.4 nm airglow images support that the depletions and enhancements of 630.0 nm night time airglow reflect plasma density decreases and increases (blobs), respectively. Characteristics of the airglow depletions, in the context of the LEO satellite data, further suggest that the plasma density depletion deduced from the airglow data represents equatorial plasma bubbles (EPBs) rather than medium-scale traveling ionospheric disturbances from midlatitudes. Hence, the event in this study can be interpreted as EPB-to-blob transition.

First OH Airglow Observation of Mesospheric Gravity Waves Over European Russia Region

Science.gov (United States)

Li, Qinzeng; Yusupov, Kamil; Akchurin, Adel; Yuan, Wei; Liu, Xiao; Xu, Jiyao

2018-03-01

For the first time, we perform a study of mesospheric gravity waves (GWs) for four different seasons of 1 year in the latitudinal band from 45°N to 75°N using an OH all-sky airglow imager over Kazan (55.8°N, 49.2°E), Russia, during the period of August 2015 to July 2016. Our observational study fills a huge airglow imaging observation gap in Europe and Russia region. In total, 125 GW events and 28 ripple events were determined by OH airglow images in 98 clear nights. The observed GWs showed a strong preference of propagation toward northeast in all seasons, which was significantly different from airglow imager observations at other latitudes that the propagation directions were seasonal dependent. The middle atmosphere wind field is used to explain the lack of low phase speed GWs since these GWs were falling into the blocking region due to the filtering effects. Deep tropospheric convections derived from the European Centre for Medium-Range Weather Forecasts reanalysis data are determined near Caucasus Mountains region, which suggests that the convections are the dominant source of the GWs in spring, summer, and autumn seasons. This finding extends our knowledge that convection might also be an important source of GWs in the higher latitudes. In winter the generation mechanism of the GWs are considered to be jet stream systems. In addition, the occurrence frequency of ripple is much lower than other stations. This study provides some constraints on the range of GW parameters in GW parameterization in general circulation models in Europe and Russia region.

Extreme ultra-violet movie camera for imaging microsecond time scale magnetic reconnection

International Nuclear Information System (INIS)

Chai, Kil-Byoung; Bellan, Paul M.

2013-01-01

An ultra-fast extreme ultra-violet (EUV) movie camera has been developed for imaging magnetic reconnection in the Caltech spheromak/astrophysical jet experiment. The camera consists of a broadband Mo:Si multilayer mirror, a fast decaying YAG:Ce scintillator, a visible light block, and a high-speed visible light CCD camera. The camera can capture EUV images as fast as 3.3 × 10 6 frames per second with 0.5 cm spatial resolution. The spectral range is from 20 eV to 60 eV. EUV images reveal strong, transient, highly localized bursts of EUV radiation when magnetic reconnection occurs

Extreme ultra-violet movie camera for imaging microsecond time scale magnetic reconnection

Energy Technology Data Exchange (ETDEWEB)

Chai, Kil-Byoung; Bellan, Paul M. [Applied Physics, Caltech, 1200 E. California Boulevard, Pasadena, California 91125 (United States)

2013-12-15

An ultra-fast extreme ultra-violet (EUV) movie camera has been developed for imaging magnetic reconnection in the Caltech spheromak/astrophysical jet experiment. The camera consists of a broadband Mo:Si multilayer mirror, a fast decaying YAG:Ce scintillator, a visible light block, and a high-speed visible light CCD camera. The camera can capture EUV images as fast as 3.3 × 10{sup 6} frames per second with 0.5 cm spatial resolution. The spectral range is from 20 eV to 60 eV. EUV images reveal strong, transient, highly localized bursts of EUV radiation when magnetic reconnection occurs.

Silicon photodiode with selective Zr/Si coating for extreme ultraviolet spectral range

International Nuclear Information System (INIS)

Aruev, P N; Barysheva, Mariya M; Ber, B Ya; Zabrodskaya, N V; Zabrodskii, V V; Lopatin, A Ya; Pestov, Alexey E; Petrenko, M V; Polkovnikov, V N; Salashchenko, Nikolai N; Sukhanov, V L; Chkhalo, Nikolai I

2012-01-01

The procedure of manufacturing silicon photodiodes with an integrated Zr/Si filter for extreme ultraviolet (EUV) spectral range is developed. A setup for measuring the sensitivity profile of detectors with spatial resolution better than 100 μm is fabricated. The optical properties of silicon photodiodes in the EUV and visible spectral ranges are investigated. Some characteristics of SPD-100UV diodes with Zr/Si coating and without it, as well as of AXUV-100 diodes, are compared. In all types of detectors a narrow region beyond the operating aperture is found to be sensitive to the visible light. (photodetectors)

Extreme ultra-violet emission spectroscopy of highly charged gadolinium ions with an electron beam ion trap

International Nuclear Information System (INIS)

Ohashi, Hayato; Nakamura, Nobuyuki; Sakaue, Hiroyuki A

2013-01-01

We present extreme ultra-violet emission spectra of highly charged gadolinium ions obtained with an electron beam ion trap at electron energies of 0.53–1.51 keV. The electron energy dependence of the spectra in the 5.7–11.3 nm range is compared with calculation with the flexible atomic code. (paper)

The LBL [Lawrence Berkeley Laboratory] 1-2 GeV synchrotron radiation source

International Nuclear Information System (INIS)

Cornacchia, M.

1987-03-01

A description is presented of the conceptual design of the 1 to 2 GeV Synchrotron Radiation Source proposed for construction at Lawrence Berkeley Laboratory. This facility is designed to produce ultraviolet and soft x-ray radiation. The accelerator complex consists of an injection system (linac plus booster synchrotron) and a low-emittance storage ring optimized for insertion devices. Eleven straight sections are available for undulators and wigglers, and up to 48 photon beam lines may ultimately emanate from bending magnets. Design features of the radiation source are the high brightness of the photon beams, the very short pulses (tens of picoseconds), and the tunability of the radiation

Broadband interference lithography at extreme ultraviolet and soft x-ray wavelengths.

Science.gov (United States)

Mojarad, Nassir; Fan, Daniel; Gobrecht, Jens; Ekinci, Yasin

2014-04-15

Manufacturing efficient and broadband optics is of high technological importance for various applications in all wavelength regimes. Particularly in the extreme ultraviolet and soft x-ray spectra, this becomes challenging due to the involved atomic absorption edges that rapidly change the optical constants in these ranges. Here we demonstrate a new interference lithography grating mask that can be used for nanopatterning in this spectral range. We demonstrate photolithography with cutting-edge resolution at 6.5 and 13.5 nm wavelengths, relevant to the semiconductor industry, as well as using 2.5 and 4.5 nm wavelength for patterning thick photoresists and fabricating high-aspect-ratio metal nanostructures for plasmonics and sensing applications.

AN AUTOMATIC DETECTION METHOD FOR EXTREME-ULTRAVIOLET DIMMINGS ASSOCIATED WITH SMALL-SCALE ERUPTION

Energy Technology Data Exchange (ETDEWEB)

Alipour, N.; Safari, H. [Department of Physics, University of Zanjan, P.O. Box 45195-313, Zanjan (Iran, Islamic Republic of); Innes, D. E. [Max-Planck Institut fuer Sonnensystemforschung, 37191 Katlenburg-Lindau (Germany)

2012-02-10

Small-scale extreme-ultraviolet (EUV) dimming often surrounds sites of energy release in the quiet Sun. This paper describes a method for the automatic detection of these small-scale EUV dimmings using a feature-based classifier. The method is demonstrated using sequences of 171 Angstrom-Sign images taken by the STEREO/Extreme UltraViolet Imager (EUVI) on 2007 June 13 and by Solar Dynamics Observatory/Atmospheric Imaging Assembly on 2010 August 27. The feature identification relies on recognizing structure in sequences of space-time 171 Angstrom-Sign images using the Zernike moments of the images. The Zernike moments space-time slices with events and non-events are distinctive enough to be separated using a support vector machine (SVM) classifier. The SVM is trained using 150 events and 700 non-event space-time slices. We find a total of 1217 events in the EUVI images and 2064 events in the AIA images on the days studied. Most of the events are found between latitudes -35 Degree-Sign and +35 Degree-Sign . The sizes and expansion speeds of central dimming regions are extracted using a region grow algorithm. The histograms of the sizes in both EUVI and AIA follow a steep power law with slope of about -5. The AIA slope extends to smaller sizes before turning over. The mean velocity of 1325 dimming regions seen by AIA is found to be about 14 km s{sup -1}.

Reflective masks for extreme ultraviolet lithography

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Khanh Bao [Univ. of California, Berkeley, CA (United States)

1994-05-01

Extreme ultraviolet lithographic masks are made by patterning multilayer reflective coatings with high normal incidence reflectivity. Masks can be patterned by depositing a patterned absorber layer above the coating or by etching the pattern directly into the coating itself. Electromagnetic simulations showed that absorber-overlayer masks have superior imaging characteristics over etched masks (less sensitive to incident angles and pattern profiles). In an EUVL absorber overlayer mask, defects can occur in the mask substrate, reflective coating, and absorber pattern. Electromagnetic simulations showed that substrate defects cause the most severe image degradation. A printability study of substrate defects for absorber overlayer masks showed that printability of 25 nm high substrate defects are comparable to defects in optical lithography. Simulations also indicated that the manner in which the defects are covered by multilayer reflective coatings can affect printability. Coverage profiles that result in large lateral spreading of defect geometries amplify the printability of the defects by increasing their effective sizes. Coverage profiles of Mo/Si coatings deposited above defects were studied by atomic force microscopy and TEM. Results showed that lateral spread of defect geometry is proportional to height. Undercut at defect also increases the lateral spread. Reductions in defect heights were observed for 0.15 μm wide defect lines. A long-term study of Mo/Si coating reflectivity revealed that Mo/Si coatings with Mo as the top layer suffer significant reductions in reflectivity over time due to oxidation.

Dissociative multiple ionization of diatomic molecules by extreme-ultraviolet free-electron-laser pulses

DEFF Research Database (Denmark)

Madsen, Lars Bojer; Leth, Henriette Astrup

2011-01-01

Nuclear dynamics in dissociative multiple ionization processes of diatomic molecules exposed to extreme-ultraviolet free-electron-laser pulses is studied theoretically using the Monte Carlo wave packet approach. By simulated detection of the emitted electrons, the model reduces a full propagation...... of the system to propagations of the nuclear wave packet in one specific electronic charge state at a time. Suggested ionization channels can be examined, and kinetic energy release spectra for the nuclei can be calculated and compared with experiments. Double ionization of O2 is studied as an example, and good...

Characterization of carbon contamination under ion and hot atom bombardment in a tin-plasma extreme ultraviolet light source

NARCIS (Netherlands)

Dolgov, A.; Lopaev, D.; Lee, Christopher James; Zoethout, E.; Medvedev, Viacheslav; Yakushev, O.; Bijkerk, Frederik

2015-01-01

Molecular contamination of a grazing incidence collector for extreme ultraviolet (EUV) lithography was experimentally studied. A carbon film was found to have grown under irradiation from a pulsed tin plasma discharge. Our studies show that the film is chemically inert and has characteristics that

Extreme Science (LBNL Science at the Theater)

Energy Technology Data Exchange (ETDEWEB)

Ajo-Franklin, Caroline; Klein, Spencer; Minor, Andrew; Torok, Tamas

2012-02-27

On Feb. 27, 2012 at the Berkeley Repertory Theatre, four Berkeley Lab scientists presented talks related to extreme science - and what it means to you. Topics include: Neutrino hunting in Antarctica. Learn why Spencer Klein goes to the ends of the Earth to search for these ghostly particles. From Chernobyl to Central Asia, Tamas Torok travels the globe to study microbial diversity in extreme environments. Andrew Minor uses the world's most advanced electron microscopes to explore materials at ultrahigh stresses and in harsh environments. And microbes that talk to computers? Caroline Ajo-Franklin is pioneering cellular-electrical connections that could help transform sunlight into fuel.

The radioactive inventory of a Berkeley heat exchanger

International Nuclear Information System (INIS)

Hancock, R.

1988-10-01

The Central Electricity Generating Board has announced a date for the final shutdown of the first of the Magnox power stations at Berkeley (March 1989), and is in the process of preparing Pre-Decommissioning Safety Reports (PDSR) for the decommissioning of Berkeley and Bradwell. This report supports these PDSR studies and reports work carried out within the Research Division at Berkeley Nuclear Laboratories on the radioactive inventories of the heat exchangers at Berkeley Power Station. At Berkeley, the heat exchangers will be included in stage two decommissioning to which they will contribute the largest mass of contaminated material. The purpose of this report is to bring together all of the available data on the contamination in the heat exchangers at Berkeley Power Station, and to recommend a database from which the options for disposal of the heat exchangers may be formulated. (author)

Environmental research at Berkeley

CERN Multimedia

1973-01-01

The information concerning the Energy and Environment Programme at the Lawrence Berkeley Laboratory is based on a talk given at CERN by A.M. Sessler, one of the initiators of the Programme. (Dr. Sessler has been appointed Director of the Lawrence Berkeley Laboratory, in succession to Prof. E. M. McMillan, from 1 November.) Many of the topics mentioned merit an extended story in themselves but the purpose of this article is simply to give a sketch of what is happening.

Diversity, Equity, & Inclusion at Berkeley Lab

Science.gov (United States)

Berkeley Lab A-Z Index Directory Search Diversity, Equity, & Inclusion at Berkeley Lab Home Diversity & Inclusion Council Women Scientists & Engineers Council Employee Resource Groups -and culture of inclusion are key to attracting and engaging the brightest minds and furthering our

EIT: Solar corona synoptic observations from SOHO with an Extreme-ultraviolet Imaging Telescope

Science.gov (United States)

Delaboudiniere, J. P.; Gabriel, A. H.; Artzner, G. E.; Michels, D. J.; Dere, K. P.; Howard, R. A.; Catura, R.; Stern, R.; Lemen, J.; Neupert, W.

1988-01-01

The Extreme-ultraviolet Imaging Telescope (EIT) of SOHO (solar and heliospheric observatory) will provide full disk images in emission lines formed at temperatures that map solar structures ranging from the chromospheric network to the hot magnetically confined plasma in the corona. Images in four narrow bandpasses will be obtained using normal incidence multilayered optics deposited on quadrants of a Ritchey-Chretien telescope. The EIT is capable of providing a uniform one arc second resolution over its entire 50 by 50 arc min field of view. Data from the EIT will be extremely valuable for identifying and interpreting the spatial and temperature fine structures of the solar atmosphere. Temporal analysis will provide information on the stability of these structures and identify dynamical processes. EIT images, issued daily, will provide the global corona context for aid in unifying the investigations and in forming the observing plans for SOHO coronal instruments.

Laboratory studies on the excitation and collisional deactivation of metastable atoms and molecules in the aurora and airglow

International Nuclear Information System (INIS)

Zipf, E.C.

1974-02-01

The aeronomy group at the University of Pittsburgh is actively engaged in a series of coordinated satellite, sounding rocket, and laboratory studies designed to expand and clarify knowledge of the physics and chemistry of planetary atmospheres. Three major discoveries have been made that will lead ultimately to a complete and dramatic revision of our ideas on the ionospheres of Mars, Venus, and the Earth and on the origin of their vacuum ultraviolet airglows. The results have already suggested a new generation of ionosphere studies which probably can be carried out best by laser heterodyning techniques. Laboratory studies have also identified, for the first time, the physical mechanism responsible for the remarkable nitric oxide buildup observed in some auroral arcs. This development is an important break-through in auroral physics, and has military ramifications of considerable interest to the Department of Defense. This work may also shed some light on related NO and atomic nitrogen problems in the mesosphere. (U.S.)

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)

Complementary ion and extreme ultra-violet spectrometer for laser-plasma diagnosis.

Science.gov (United States)

Ter-Avetisyan, S; Ramakrishna, B; Doria, D; Sarri, G; Zepf, M; Borghesi, M; Ehrentraut, L; Stiel, H; Steinke, S; Priebe, G; Schnürer, M; Nickles, P V; Sandner, W

2009-10-01

Simultaneous detection of extreme ultra-violet (XUV) and ion emission along the same line of sight provides comprehensive insight into the evolution of plasmas. This type of combined spectroscopy is applied to diagnose laser interaction with a spray target. The use of a micro-channel-plate detector assures reliable detection of both XUV and ion signals in a single laser shot. The qualitative analysis of the ion emission and XUV spectra allows to gain detailed information about the plasma conditions, and a correlation between the energetic proton emission and the XUV plasma emission can be suggested. The measured XUV emission spectrum from water spray shows efficient deceleration of laser accelerated electrons with energies up to keV in the initially cold background plasma and the collisional heating of the plasma.

Complementary ion and extreme ultra-violet spectrometer for laser-plasma diagnosis

International Nuclear Information System (INIS)

Ter-Avetisyan, S.; Ramakrishna, B.; Doria, D.; Sarri, G.; Zepf, M.; Borghesi, M.; Ehrentraut, L.; Stiel, H.; Steinke, S.; Schnuerer, M.; Nickles, P. V.; Sandner, W.; Priebe, G.

2009-01-01

Simultaneous detection of extreme ultra-violet (XUV) and ion emission along the same line of sight provides comprehensive insight into the evolution of plasmas. This type of combined spectroscopy is applied to diagnose laser interaction with a spray target. The use of a micro-channel-plate detector assures reliable detection of both XUV and ion signals in a single laser shot. The qualitative analysis of the ion emission and XUV spectra allows to gain detailed information about the plasma conditions, and a correlation between the energetic proton emission and the XUV plasma emission can be suggested. The measured XUV emission spectrum from water spray shows efficient deceleration of laser accelerated electrons with energies up to keV in the initially cold background plasma and the collisional heating of the plasma.

CAN A NANOFLARE MODEL OF EXTREME-ULTRAVIOLET IRRADIANCES DESCRIBE THE HEATING OF THE SOLAR CORONA?

Energy Technology Data Exchange (ETDEWEB)

Tajfirouze, E.; Safari, H. [Department of Physics, University of Zanjan, P.O. Box 45195-313, Zanjan (Iran, Islamic Republic of)

2012-01-10

Nanoflares, the basic units of impulsive energy release, may produce much of the solar background emission. Extrapolation of the energy frequency distribution of observed microflares, which follows a power law to lower energies, can give an estimation of the importance of nanoflares for heating the solar corona. If the power-law index is greater than 2, then the nanoflare contribution is dominant. We model a time series of extreme-ultraviolet emission radiance as random flares with a power-law exponent of the flare event distribution. The model is based on three key parameters: the flare rate, the flare duration, and the power-law exponent of the flare intensity frequency distribution. We use this model to simulate emission line radiance detected in 171 A, observed by Solar Terrestrial Relation Observatory/Extreme-Ultraviolet Imager and Solar Dynamics Observatory/Atmospheric Imaging Assembly. The observed light curves are matched with simulated light curves using an Artificial Neural Network, and the parameter values are determined across the active region, quiet Sun, and coronal hole. The damping rate of nanoflares is compared with the radiative losses cooling time. The effect of background emission, data cadence, and network sensitivity on the key parameters of the model is studied. Most of the observed light curves have a power-law exponent, {alpha}, greater than the critical value 2. At these sites, nanoflare heating could be significant.

Divertor extreme ultraviolet (EUV) survey spectroscopy in DIII-D

Science.gov (United States)

McLean, Adam; Allen, Steve; Ellis, Ron; Jarvinen, Aaro; Soukhanovskii, Vlad; Boivin, Rejean; Gonzales, Eduardo; Holmes, Ian; Kulchar, James; Leonard, Anthony; Williams, Bob; Taussig, Doug; Thomas, Dan; Marcy, Grant

2017-10-01

An extreme ultraviolet spectrograph measuring resonant emissions of D and C in the lower divertor has been added to DIII-D to help resolve an 2X discrepancy between bolometrically measured radiated power and that predicted by boundary codes for DIII-D, JET and ASDEX-U. With 290 and 450 gr/mm gratings, the DivSPRED spectrometer, an 0.3 m flat-field McPherson model 251, measures ground state transitions for D (the Lyman series) and C (e.g., C IV, 155 nm) which account for >75% of radiated power in the divertor. Combined with Thomson scattering and imaging in the DIII-D divertor, measurements of position, temperature and fractional power emission from plasma components are made and compared to UEDGE/SOLPS-ITER. Mechanical, optical, electrical, vacuum, and shielding aspects of DivSPRED are presented. Work supported under USDOE Cooperative Agreement DE-FC02-04ER54698 and DE-AC52-07NA27344, and by the LLNL Laboratory Directed R&D Program, project #17-ERD-020.

Treatment of Berkeley boilers in Studsvik. Project description and experiences - Berkeley Boilers Project

International Nuclear Information System (INIS)

Saul, Dave; Davidson, Gavin; Wirendal, Bo

2014-01-01

In November 2011 Studsvik was awarded a contract to transport five decommissioned boilers from the Berkeley Nuclear Licensed Site in the UK to the Studsvik Nuclear Site in Sweden for metal treatment and recycling. A key objective of the project was to remove the boilers from the site by 31 March 2012 and this was successfully achieved with all boilers off site by 22 March and delivered to Studsvik on 6 April. In November 2012 Studsvik was awarded a further contract for the remaining ten Berkeley Boilers with the requirement to remove all boilers from the Berkeley site by 31 March 2013. Again this was successfully achieved ahead of programme with all boilers in Sweden by 1 April 2013. A total of nine boilers have now been processed and all remaining boilers will be completed by end of September 2014. The projects have had many challenges including a very tight timescale and both have been successfully delivered to cost and ahead of the baseline programme. This paper describes the project and the experience gained from treatment of the boilers to date. (authors)

Detection of large-scale concentric gravity waves from a Chinese airglow imager network

Science.gov (United States)

Lai, Chang; Yue, Jia; Xu, Jiyao; Yuan, Wei; Li, Qinzeng; Liu, Xiao

2018-06-01

Concentric gravity waves (CGWs) contain a broad spectrum of horizontal wavelengths and periods due to their instantaneous localized sources (e.g., deep convection, volcanic eruptions, or earthquake, etc.). However, it is difficult to observe large-scale gravity waves of >100 km wavelength from the ground for the limited field of view of a single camera and local bad weather. Previously, complete large-scale CGW imagery could only be captured by satellite observations. In the present study, we developed a novel method that uses assembling separate images and applying low-pass filtering to obtain temporal and spatial information about complete large-scale CGWs from a network of all-sky airglow imagers. Coordinated observations from five all-sky airglow imagers in Northern China were assembled and processed to study large-scale CGWs over a wide area (1800 km × 1 400 km), focusing on the same two CGW events as Xu et al. (2015). Our algorithms yielded images of large-scale CGWs by filtering out the small-scale CGWs. The wavelengths, wave speeds, and periods of CGWs were measured from a sequence of consecutive assembled images. Overall, the assembling and low-pass filtering algorithms can expand the airglow imager network to its full capacity regarding the detection of large-scale gravity waves.

The first coordinated observations of mid-latitude E-region quasi-periodic radar echoes and lower thermospheric 557.7-nm airglow

Directory of Open Access Journals (Sweden)

T. Ogawa

2005-10-01

Full Text Available We present the first coordinated observations of quasi-periodic (QP radar echoes from sporadic-E (Es field-aligned irregularities (FAIs, OI 557.7-nm airglow, and neutral winds in a common volume over Shigaraki, Japan (34.9° N, 136.1° E on the night of 5 August 2002 during the SEEK-2 campaign. QP echo altitudes of 90-110 km were lower than usual by 10 km, enabling us to make a detailed comparison among QP echoes, airglow intensity, and neutral wind at around 96 km altitude. Eastward movement of the QP echo regions is consistent with the motions of neutral winds, airglow structures, and FAIs, suggesting that the electrodynamics of Es-layers is fundamentally controlled by the neutral atmospheric dynamics. During the QP echo event, the echo altitudes clearly went up (down in harmony with an airglow enhancement (subsidence that also moved to the east. This fact suggests that the eastward-moving enhanced airglow region included an upward (downward component of neutral winds to raise (lower the altitude of the wind-shear node responsible for the Es formation. The airglow intensity, echo intensity, and Doppler velocity of FAIs at around 96 km altitude fluctuated with periods from 10 min to 1h, indicating that these parameters were modulated with short-period atmospheric disturbances. Some QP echo regions below 100km altitude contained small-scale QP structures in which very strong neutral winds exceeding 100 m/s existed. The results are compared with recent observations, theories, and simulations of QP echoes. Keywords. Ionosphere (Ionosphere-atmosphere interactions; Ionospheric irregularities; Mid-latitude ionosphere

Extreme ultraviolet (EUV) and FUV calibration facility for special sensor ultraviolet limb imager (SSULI)

Science.gov (United States)

Boyer, Craig N.; Osterman, Steven N.; Thonnard, Stefan E.; McCoy, Robert P.; Williams, J. Z.; Parker, S. E.

1994-09-01

A facility for calibrating far ultraviolet and extreme ultraviolet instruments has recently been completed at the Naval Research Laboratory. Our vacuum calibration vessel is 2-m in length, 1.67-m in diameter, and can accommodate optical test benches up to 1.2-m wide by 1.5-m in length. A kinematically positioned frame with four axis precision pointing capability of 10 microns for linear translation and .01 degrees for rotation is presently used during vacuum optical calibration of SSULI. The chamber was fabricated from 304 stainless steel and polished internally to reduce surface outgassing. A dust-free environment is maintained at the rear of the vacuum chamber by enclosing the 2-m hinged vacuum access door in an 8 ft. by 8 ft. class 100 clean room. Every effort was made to obtain an oil-free environment within the vacuum vessel. Outgassing products are continually monitored with a 1 - 200 amu residual gas analyzer. An oil-free claw and vane pump evacuates the chamber to 10-2 torr through 4 in. diameter stainless steel roughing lines. High vacuum is achieved and maintained with a magnetically levitated 480 l/s turbo pump and a 3000 l/s He4 cryopump. Either of two vacuum monochrometers, a 1-m f/10.4 or a 0.2-m f/4.5 are coaxially aligned with the optical axis of the chamber and are used to select single UV atomic resonance lines from a windowless capillary or penning discharge UV light source. A calibrated channeltron detector is coaxially mounted with the SSULI detector during calibration. All vacuum valves, the cooling system for the cryopump compressor, and the roughing pump are controlled through optical fibers which are interfaced to a computer through a VME board. Optical fibers were chosen to ensure that complete electrical isolation is maintained between the computer and the vacuum system valves-solenoids and relays.

Exploring the temporally resolved electron density evolution in extreme ultra-violet induced plasmas

International Nuclear Information System (INIS)

Van der Horst, R M; Beckers, J; Nijdam, S; Kroesen, G M W

2014-01-01

We measured the electron density in an extreme ultra-violet (EUV) induced plasma. This is achieved in a low-pressure argon plasma by using a method called microwave cavity resonance spectroscopy. The measured electron density just after the EUV pulse is 2.6 × 10 16  m −3 . This is in good agreement with a theoretical prediction from photo-ionization, which yields a density of 4.5 × 10 16  m −3 . After the EUV pulse the density slightly increases due to electron impact ionization. The plasma (i.e. electron density) decays in tens of microseconds. (fast track communication)

Tidal and gravity waves study from the airglow measurements at ...

Indian Academy of Sciences (India)

E) during the period 2004–2007 are analyzed to study the dominant waves present in the 80–100 km altitude region of the atmosphere. The nocturnal intensity variations of different airglow emissions are observed using scanning temperature controlled filter photometers. Waves having period lying between 2 and 12 hours ...

Demonstration of pattern transfer into sub-100 nm polysilicon line/space features patterned with extreme ultraviolet lithography

International Nuclear Information System (INIS)

Cardinale, G. F.; Henderson, C. C.; Goldsmith, J. E. M.; Mangat, P. J. S.; Cobb, J.; Hector, S. D.

1999-01-01

In two separate experiments, we have successfully demonstrated the transfer of dense- and loose-pitch line/space (L/S) photoresist features, patterned with extreme ultraviolet (EUV) lithography, into an underlying hard mask material. In both experiments, a deep-UV photoresist (∼90 nm thick) was spin cast in bilayer format onto a hard mask (50-90 nm thick) and was subsequently exposed to EUV radiation using a 10x reduction EUV exposure system. The EUV reticle was fabricated at Motorola (Tempe, AZ) using a subtractive process with Ta-based absorbers on Mo/Si multilayer mask blanks. In the first set of experiments, following the EUV exposures, the L/S patterns were transferred first into a SiO 2 hard mask (60 nm thick) using a reactive ion etch (RIE), and then into polysilicon (350 nm thick) using a triode-coupled plasma RIE etcher at the University of California, Berkeley, microfabrication facilities. The latter etch process, which produced steep (>85 degree sign ) sidewalls, employed a HBr/Cl chemistry with a large (>10:1) etch selectivity of polysilicon to silicon dioxide. In the second set of experiments, hard mask films of SiON (50 nm thick) and SiO 2 (87 nm thick) were used. A RIE was performed at Motorola using a halogen gas chemistry that resulted in a hard mask-to-photoresist etch selectivity >3:1 and sidewall profile angles ≥85 degree sign . Line edge roughness (LER) and linewidth critical dimension (CD) measurements were performed using Sandia's GORA(c) CD digital image analysis software. Low LER values (6-9 nm, 3σ, one side) and good CD linearity (better than 10%) were demonstrated for the final pattern-transferred dense polysilicon L/S features from 80 to 175 nm. In addition, pattern transfer (into polysilicon) of loose-pitch (1:2) L/S features with CDs≥60 nm was demonstrated. (c) 1999 American Vacuum Society

Surface roughness control by extreme ultraviolet (EUV) radiation

Science.gov (United States)

Ahad, Inam Ul; Obeidi, Muhannad Ahmed; Budner, Bogusław; Bartnik, Andrzej; Fiedorowicz, Henryk; Brabazon, Dermot

2017-10-01

Surface roughness control of polymeric materials is often desirable in various biomedical engineering applications related to biocompatibility control, separation science and surface wettability control. In this study, Polyethylene terephthalate (PET) polymer films were irradiated with Extreme ultraviolet (EUV) photons in nitrogen environment and investigations were performed on surface roughness modification via EUV exposure. The samples were irradiated at 3 mm and 4 mm distance from the focal spot to investigate the effect of EUV fluence on topography. The topography of the EUV treated PET samples were studied by AFM. The detailed scanning was also performed on the sample irradiated at 3 mm. It was observed that the average surface roughness of PET samples was increased from 9 nm (pristine sample) to 280 nm and 253 nm for EUV irradiated samples. Detailed AFM studies confirmed the presence of 1.8 mm wide period U-shaped channels in EUV exposed PET samples. The walls of the channels were having FWHM of about 0.4 mm. The channels were created due to translatory movements of the sample in horizontal and transverse directions during the EUV exposure. The increased surface roughness is useful for many applications. The nanoscale channels fabricated by EUV exposure could be interesting for microfluidic applications based on lab-on-a-chip (LOC) devices.

Extreme ultraviolet observations of coronal holes. II

International Nuclear Information System (INIS)

Bohlin, J.D.; Sheeley, N.R. Jr.

1978-01-01

Extreme-ultraviolet Skylab and ground-based solar magnetic field data have been combined to study the origin and evolution of coronal holes. It is shown that holes exist only within the large-scale unipolar magnetic cells into which the solar surface is divided at any given time. A well-defined boundary zone usually exists between the edge of a hole and the neutral line which marks the edge of its magnetic cell. This boundary zone is the region across which a cell is connected by magnetic arcades with adjacent cells of opposite polarity. Three pieces of observational evidence are offered to support the hypothesis that the magnetic lines of force from a hole are open. Kitt Peak magnetograms are used to show that, at least on a relative scale, the average field strengths within holes are quite variable, but indistinguishable from the field strengths in other quiet parts of the Sun's surface. Finally it is shown that the large, equatorial holes characteristic of the declining phase of the last solar cycle during Skylab (1973-74) were all formed as a result of the mergence of bipolar magnetic regions (BMR's), confirming an earlier hypothesis by Timothy et al. (1975). Systematic application of this model to the different aspects of the solar cycle correctly predicts the occurrence of both large, equatorial coronal holes (the 'M-regions' which cause recurrent geomagnetic storms) and the polar cap holes. (Auth.)

Berkeley Low Background Facility

International Nuclear Information System (INIS)

Thomas, K. J.; Norman, E. B.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Lesko, K. T.

2015-01-01

The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects

Broadband transmission masks, gratings and filters for extreme ultraviolet and soft X-ray lithography

International Nuclear Information System (INIS)

Brose, S.; Danylyuk, S.; Juschkin, L.; Dittberner, C.; Bergmann, K.; Moers, J.; Panaitov, G.; Trellenkamp, St.; Loosen, P.; Grützmacher, D.

2012-01-01

Lithography and patterning on a nanometre scale with extreme ultraviolet (EUV) and soft X-ray radiation allow creation of high resolution, high density patterns independent of a substrate type. To realize the full potential of this method, especially for EUV proximity printing and interference lithography, a reliable technology for manufacturing of the transmission masks and gratings should be available. In this paper we present a development of broadband amplitude transmission masks and gratings for extreme ultraviolet and soft X-ray lithography based on free-standing niobium membranes. In comparison with a standard silicon nitride based technology the transmission masks demonstrate high contrast not only for in-band EUV (13.5 nm) radiation but also for wavelengths below Si L-absorption edge (12.4 nm). The masks and filters with free standing areas up to 1000 × 1000 μm 2 and 100 nm to 300 nm membrane thicknesses are shown. Electron beam structuring of an absorber layer with dense line and dot patterns with sub-50 nm structures is demonstrated. Diffractive and filtering properties of obtained structures are examined with EUV radiation from a gas discharge plasma source. - Highlights: ► Broadband transmission masks for EUV proximity and interference lithography. ► Technology for free standing niobium membranes with areas up to 1 mm 2 . ► High density patterns with periods of 100 nm and structure sizes below 40 nm. ► Measured diffraction efficiency at 11 nm is in agreement with the theory. ► Produced masks can be effectively used with wavelengths between 6 nm and 17 nm.

Optimizing hydroxyl airglow retrievals from long-slit astronomical spectroscopic observations

Directory of Open Access Journals (Sweden)

C. Franzen

2017-08-01

Full Text Available Astronomical spectroscopic observations from ground-based telescopes contain background emission lines from the terrestrial atmosphere's airglow. In the near infrared, this background is composed mainly of emission from Meinel bands of hydroxyl (OH, which is produced in highly excited vibrational states by reduction of ozone near 90 km. This emission contains a wealth of information on the chemical and dynamical state of the Earth's atmosphere. However, observation strategies and data reduction processes are usually optimized to minimize the influence of these features on the astronomical spectrum. Here we discuss a measurement technique to optimize the extraction of the OH airglow signal itself from routine J-, H-, and K-band long-slit astronomical spectroscopic observations. As an example, we use data recorded from a point-source observation by the Nordic Optical Telescope's intermediate-resolution spectrograph, which has a spatial resolution of approximately 100 m at the airglow layer. Emission spectra from the OH vibrational manifold from v′  =  9 down to v′  =  3, with signal-to-noise ratios up to 280, have been extracted from 10.8 s integrations. Rotational temperatures representative of the background atmospheric temperature near 90 km, the mesosphere and lower thermosphere region, can be fitted to the OH rotational lines with an accuracy of around 0.7 K. Using this measurement and analysis technique, we derive a rotational temperature distribution with v′ that agrees with atmospheric model conditions and the preponderance of previous work. We discuss the derived rotational temperatures from the different vibrational bands and highlight the potential for both the archived and future observations, which are at unprecedented spatial and temporal resolutions, to contribute toward the resolution of long-standing problems in atmospheric physics.

Small-Scale Dynamical Structures Using OH Airglow From Astronomical Observations

Science.gov (United States)

Franzen, C.; Espy, P. J.; Hibbins, R. E.; Djupvik, A. A.

2017-12-01

Remote sensing of perturbations in the hydroxyl (OH) Meinel airglow has often been used to observe gravity, tidal and planetary waves travelling through the 80-90 km region. While large scale (>1 km) gravity waves and the winds caused by their breaking are widely documented, information on the highest frequency waves and instabilities occurring during the breaking process is often limited by the temporal and spatial resolution of the available observations. In an effort to better quantify the full range of wave scales present near the mesopause, we present a series of observations of the OH Meinel (9,7) transition that were executed with the Nordic Optical Telescope on La Palma (18°W, 29°N). These measurements have a 24 s repetition rate and horizontal spatial resolutions at 87 km as small as 10 cm, allowing us to quantify the transition in the mesospheric wave domains as the gravity waves break. Temporal scales from hours to minutes, as well as sub-100 m coherent structures in the OH airglow have been observed and will be presented.

Properites of ultrathin films appropriate for optics capping layers in extreme ultraviolet lithography (EUVL)

Energy Technology Data Exchange (ETDEWEB)

Bajt, S; Edwards, N V; Madey, T E

2007-06-25

The contamination of optical surfaces by irradiation shortens optics lifetime and is one of the main concerns for optics used in conjunction with intense light sources, such as high power lasers, 3rd and 4th generation synchrotron sources or plasma sources used in extreme ultraviolet lithography (EUVL) tools. This paper focuses on properties and surface chemistry of different materials, which as thin layers, could be used as capping layers to protect and extend EUVL optics lifetime. The most promising candidates include single element materials such as ruthenium and rhodium, and oxides such as TiO{sub 2} and ZrO{sub 2}.

Thin film interference optics for imaging the O II 834-A airglow

Science.gov (United States)

Seely, John F.; Hunter, William R.

1991-01-01

Normal incidence thin film interference mirrors and filters have been designed to image the O II 834-A airglow. It is shown that MgF2 is a useful spacer material for this wavelength region. The mirrors consist of thin layers of MgF2 in combination with other materials that are chosen to reflect efficiently in a narrow band centered at 834 A. Peak reflectance of 60 percent can be obtained with a passband 200 A wide. Al/MgF2/Si and Al/MgF2/SiC interference coatings have been designed to reflect 834 A and to absorb the intense H I 1216 A airglow. An In/MgF2/In interference filter is designed to transmit 834 A and attenuate 1216 A radiation. Interference photocathode coatings for rejecting 1216 A radiation are also discussed.

STAR FORMATION NEAR BERKELEY 59: EMBEDDED PROTOSTARS

Energy Technology Data Exchange (ETDEWEB)

Rosvick, J. M. [Department of Physical Sciences, Thompson Rivers University, 900 McGill Road, Kamloops, BC V2C 0C8 (Canada); Majaess, D. [Department of Astronomy and Physics, Saint Mary' s University, Halifax, NS B3H 3C3 (Canada)

2013-12-01

A group of suspected protostars in a dark cloud northwest of the young (∼2 Myr) cluster Berkeley 59 and two sources in a pillar south of the cluster have been studied in order to determine their evolutionary stages and ascertain whether their formation was triggered by Berkeley 59. Narrowband near-infrared observations from the Observatoire du Mont Mégantic, {sup 12}CO (J = 3-2) and SCUBA-2 (450 and 850 μm) observations from the JCMT, 2MASS, and WISE images, and data extracted from the IPHAS survey catalog were used. Of 12 sources studied, two are Class I objects, while three others are flat/Class II, one of which is a T Tauri candidate. A weak CO outflow and two potential starless cores are present in the cloud, while the pillar possesses substructure at different velocities, with no outflows present. The CO spectra of both regions show peaks in the range v {sub LSR} = –15 to –17 km s{sup –1}, which agrees with the velocity adopted for Berkeley 59 (–15.7 km s{sup –1}), while spectral energy distribution models yield an average interstellar extinction A{sub V} and distance of 15 ± 2 mag and 830 ± 120 pc, respectively, for the cloud, and 6.9 mag and 912 pc for the pillar, indicating that the regions are in the same vicinity as Berkeley 59. The formation of the pillar source appears to have been triggered by Berkeley 59. It is unclear whether Berkeley 59 triggered the association's formation.

What Made Berkeley Great? The Sources of Berkeley's Sustained Academic Excellence. Research & Occasional Paper Series CSHE.3.11

Science.gov (United States)

Breslauer, George W.

2011-01-01

University of California (UC) Berkeley's chief academic officer explores the historical sources of Berkeley' academic excellence. He identifies five key factors: (1) wealth from many sources; (2) supportive and skilled governors; (3) leadership from key UC presidents; (4) the pioneering ethos within the State of California; and (5) a process of…

Final Report: Spectral Analysis of L-shell Data in the Extreme Ultraviolet from Tokamak Plasmas

Energy Technology Data Exchange (ETDEWEB)

Lepson, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jernigan, J. Garrett [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Beiersdorfer, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-02-05

We performed detailed analyses of extreme ultraviolet spectra taken by Lawrence Livermore National Laboratory on the National Spherical Torus Experiment at Princeton Plasma Physics Laboratory and on the Alcator CKmod tokamak at the M.I.T. Plasma Science and Fusion Center. We focused on the emission of iron, carbon, and other elements in several spectral band pass regions covered by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory. We documented emission lines of carbon not found in currently used solar databases and demonstrated that this emission was due to charge exchange.

Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization

Directory of Open Access Journals (Sweden)

Zheng Li

2016-07-01

Full Text Available The ultrafast nuclear and electronic dynamics of protonated water clusters H+(H2On after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. For situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20 to 40 fs driven by strong non-adiabatic effects.

Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization

Science.gov (United States)

Li, Zheng; Vendrell, Oriol

2016-01-01

The ultrafast nuclear and electronic dynamics of protonated water clusters H+(H2O)n after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. For situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20 to 40 fs driven by strong non-adiabatic effects. PMID:26798842

Extreme ultraviolet (EUV) degradation of poly(olefin sulfone)s: Towards applications as EUV photoresists

International Nuclear Information System (INIS)

Lawrie, Kirsten; Blakey, Idriss; Blinco, James; Gronheid, Roel; Jack, Kevin; Pollentier, Ivan; Leeson, Michael J.; Younkin, Todd R.; Whittaker, Andrew K.

2011-01-01

Poly(olefin sulfone)s, formed by the reaction of sulfur dioxide (SO 2 ) and an olefin, are known to be highly susceptible to degradation by radiation and thus have been identified as candidate materials for chain scission-based extreme ultraviolet lithography (EUVL) resist materials. In order to investigate this further, the synthesis and characterisation of two poly(olefin sulfone)s namely poly(1-pentene sulfone) (PPS) and poly(2-methyl-1-pentene sulfone) (PMPS), was achieved and the two materials were evaluated for possible chain scission EUVL resist applications. It was found that both materials possess high sensitivities to EUV photons; however; the rates of outgassing were extremely high. The only observed degradation products were found to be SO 2 and the respective olefin suggesting that depolymerisation takes place under irradiation in a vacuum environment. In addition to depolymerisation, a concurrent conversion of SO 2 moieties to a sulfide phase was observed using XPS.

The Preflight Photometric Calibration of the Extreme-Ultraviolet Imaging Telescope EIT

Science.gov (United States)

Dere, K. P.; Moses, J. D.; Delaboudiniere, J. -P.; Brunaud, J.; Carabetian, C.; Hochedez, J. -F.; Song, X. Y.; Catura, R. C.; Clette, F.; Defise, J. -M.

2000-01-01

This paper presents the preflight photometric calibration of the Extreme-ultraviolet Imaging Telescope (EIT) aboard the Solar and Heliospheric Observatory (SOHO). The EIT consists of a Ritchey-Chretien telescope with multilayer coatings applied to four quadrants of the primary and secondary mirrors, several filters and a backside-thinned CCD detector. The quadrants of the EIT optics were used to observe the Sun in 4 wavelength bands that peak near 171, 195, 284, and 304 . Before the launch of SOHO, the EIT mirror reflectivities, the filter transmissivities and the CCD quantum efficiency were measured and these values are described here. The instrumental throughput in terms of an effective area is presented for each of the various mirror quadrant and filter wheel combinations. The response to a coronal plasma as a function of temperature is also determined and the expected count rates are compared to the count rates observed in a coronal hole, the quiet Sun and an active region.

Berkeley mini-collider

International Nuclear Information System (INIS)

Schroeder, L.S.

1984-06-01

The Berkeley Mini-Collider, a heavy-ion collider being planned to provide uranium-uranium collisions at T/sub cm/ less than or equal to 4 GeV/nucleon, is described. The central physics to be studied at these energies and our early ideas for a collider detector are presented

ZnO quantum dot-doped graphene/h-BN/GaN-heterostructure ultraviolet photodetector with extremely high responsivity

Science.gov (United States)

Lu, Yanghua; Wu, Zhiqian; Xu, Wenli; Lin, Shisheng

2016-12-01

A ZnO quantum dot photo-doped graphene/h-BN/GaN-heterostructure ultraviolet photodetector with extremely high responsivity of more than 1915 A W-1 and detectivity of more than 1.02 × 1013 Jones (Jones = cm Hz1/2 W-1) has been demonstrated. The interfaced h-BN layer increases the barrier height at the graphene/GaN heterojunction, which decreases the dark current and improves the on/off current ratio of the device. The photo-doping effect increases the barrier height and carrier concentration at the graphene/h-BN/GaN heterojunction, thus the responsivity is improved from 1473 A W-1 to 1915 A W-1 and the detectivity is improved from 5.8 × 1012 to 1.0 × 1013 Jones. Moreover, all of the responsivity and detectivity values are the highest values among all the graphene-based ultraviolet photodetectors.

Long-term ozone decline and its effect on night airglow intensity of Li ...

Indian Academy of Sciences (India)

effect of O3 depletion on night airglow emission of Li 6708 Е line at Varanasi and Halley ... to their ground levels, they emit radiation in the ... region can also be predicted indirectly from the ... variations in neutral wind, ionization and neutral.

High-resolution Fourier-transform extreme ultraviolet photoabsorption spectroscopy of 14N15N

Science.gov (United States)

Heays, A. N.; Dickenson, G. D.; Salumbides, E. J.; de Oliveira, N.; Joyeux, D.; Nahon, L.; Lewis, B. R.; Ubachs, W.

2011-12-01

The first comprehensive high-resolution photoabsorption spectrum of 14N15N has been recorded using the Fourier-transform spectrometer attached to the Desirs beamline at the Soleil synchrotron. Observations are made in the extreme ultraviolet and span 100 000-109 000 cm-1 (100-91.7 nm). The observed absorption lines have been assigned to 25 bands and reduced to a set of transition energies, f values, and linewidths. This analysis has verified the predictions of a theoretical model of N2 that simulates its photoabsorption and photodissociation cross section by solution of an isotopomer independent formulation of the coupled-channel Schrödinger equation. The mass dependence of predissociation linewidths and oscillator strengths is clearly evident and many local perturbations of transition energies, strengths, and widths within individual rotational series have been observed.

Mapping the spectral phase of isolated attosecond pulses by extreme-ultraviolet emission spectrum.

Science.gov (United States)

Liu, Candong; Zeng, Zhinan; Li, Ruxin; Xu, Zhizhan; Nisoli, Mauro

2015-04-20

An all-optical method is proposed for the measurement of the spectral phase of isolated attosecond pulses. The technique is based on the generation of extreme-ultraviolet (XUV) radiation in a gas by the combination of an attosecond pulse and a strong infrared (IR) pulse with controlled electric field. By using a full quantum simulation, we demonstrate that, for particular temporal delays between the two pulses, the IR field can drive back to the parent ions the photoelectrons generated by the attosecond pulse, thus leading to the generation of XUV photons. It is found that the generated XUV spectrum is notably sensitive to the chirp of the attosecond pulse, which can then be reliably retrieved. A classical quantum-path analysis is further used to quantitatively explain the main features exhibited in the XUV emission.

Laboratory calibration of density-dependent lines in the extreme ultraviolet spectral region

Science.gov (United States)

Lepson, J. K.; Beiersdorfer, P.; Gu, M. F.; Desai, P.; Bitter, M.; Roquemore, L.; Reinke, M. L.

2012-05-01

We have been making spectral measurements in the extreme ultraviolet (EUV) from different laboratory sources in order to investigate the electron density dependence of various astrophysically important emission lines and to test the atomic models underlying the diagnostic line ratios. The measurement are being performed at the Livermore EBIT-I electron beam ion trap, the National Spherical Torus Experiment (NSTX) at Princeton, and the Alcator C-Mod tokamak at the Massachusetts Institute of Technology, which together span an electron density of four orders of magnitude and which allow us to test the various models at high and low density limits. Here we present measurements of Fe XXII and Ar XIV, which include new data from an ultra high resolution (λ/Δλ >4000) spectrometer at the EBIT-I facility. We found good agreement between the measurements and modeling calculations for Fe XXII, but poorer agreement for Ar XIV.

Methods and apparatus for use with extreme ultraviolet light having contamination protection

Science.gov (United States)

Chilese, Francis C.; Torczynski, John R.; Garcia, Rudy; Klebanoff, Leonard E.; Delgado, Gildardo R.; Rader, Daniel J.; Geller, Anthony S.; Gallis, Michail A.

2016-07-12

An apparatus for use with extreme ultraviolet (EUV) light comprising A) a duct having a first end opening, a second end opening and an intermediate opening intermediate the first end opening the second end opening, B) an optical component disposed to receive EUV light from the second end opening or to send light through the second end opening, and C) a source of low pressure gas at a first pressure to flow through the duct, the gas having a high transmission of EUV light, fluidly coupled to the intermediate opening. In addition to or rather than gas flow the apparatus may have A) a low pressure gas with a heat control unit thermally coupled to at least one of the duct and the optical component and/or B) a voltage device to generate voltage between a first portion and a second portion of the duet with a grounded insulative portion therebetween.

Telescience - Concepts And Contributions To The Extreme Ultraviolet Explorer Mission

Science.gov (United States)

Marchant, Will; Dobson, Carl; Chakrabarti, Supriya; Malina, Roger F.

1987-10-01

A goal of the telescience concept is to allow scientists to use remotely located instruments as they would in their laboratory. Another goal is to increase reliability and scientific return of these instruments. In this paper we discuss the role of transparent software tools in development, integration, and postlaunch environments to achieve hands on access to the instrument. The use of transparent tools helps to reduce the parallel development of capability and to assure that valuable pre-launch experience is not lost in the operations phase. We also discuss the use of simulation as a rapid prototyping technique. Rapid prototyping provides a cost-effective means of using an iterative approach to instrument design. By allowing inexpensive produc-tion of testbeds, scientists can quickly tune the instrument to produce the desired scientific data. Using portions of the Extreme Ultraviolet Explorer (EUVE) system, we examine some of the results of preliminary tests in the use of simulation and tran-sparent tools. Additionally, we discuss our efforts to upgrade our software "EUVE electronics" simulator to emulate a full instrument, and give the pros and cons of the simulation facilities we have developed.

Extreme ultraviolet narrow band emission from electron cyclotron resonance plasmas

International Nuclear Information System (INIS)

Zhao, H. Y.; Zhao, H. W.; Sun, L. T.; Zhang, X. Z.; Wang, H.; Ma, B. H.; Li, X. X.; Zhu, Y. H.; Sheng, L. S.; Zhang, G. B.; Tian, Y. C.

2008-01-01

Extreme ultraviolet lithography (EUVL) is considered as the most promising solution at and below dynamic random access memory 32 nm half pitch among the next generation lithography, and EUV light sources with high output power and sufficient lifetime are crucial for the realization of EUVL. However, there is no EUV light source completely meeting the requirements for the commercial application in lithography yet. Therefore, ECR plasma is proposed as a novel concept EUV light source. In order to investigate the feasibility of ECR plasma as a EUV light source, the narrow band EUV power around 13.5 nm emitted by two highly charged ECR ion sources--LECR2M and SECRAL--was measured with a calibrated EUV power measurement tool. Since the emission lines around 13.5 nm can be attributed to the 4d-5p transitions of Xe XI or the 4d-4f unresolved transition array of Sn VIII-XIII, xenon plasma was investigated. The dependence of the EUV throughput and the corresponding conversion efficiency on the parameters of the ion source, such as the rf power and the magnetic confinement configurations, were preliminarily studied

ZnO quantum dot-doped graphene/h-BN/GaN-heterostructure ultraviolet photodetector with extremely high responsivity.

Science.gov (United States)

Lu, Yanghua; Wu, Zhiqian; Xu, Wenli; Lin, Shisheng

2016-12-02

A ZnO quantum dot  photo-doped graphene/h-BN/GaN-heterostructure ultraviolet photodetector with extremely high responsivity of more than 1915 A W -1 and detectivity of more than 1.02 × 10 13 Jones (Jones = cm Hz 1/2 W -1 ) has been demonstrated. The interfaced h-BN layer increases the barrier height at the graphene/GaN heterojunction, which decreases the dark current and improves the on/off current ratio of the device. The photo-doping effect increases the barrier height and carrier concentration at the graphene/h-BN/GaN heterojunction, thus the responsivity is improved from 1473 A W -1 to 1915 A W -1 and the detectivity is improved from 5.8 × 10 12 to 1.0 × 10 13 Jones. Moreover, all of the responsivity and detectivity values are the highest values among all the graphene-based ultraviolet photodetectors.

City of Berkeley, California Municipal Tree Resource Analysis

Science.gov (United States)

S.E. Maco; E.G. McPherson; J.R. Simpson; P.J. Peper; Q. Xiao

2005-01-01

Vibrant, renowned for its livability and cultural wealth, the city of Berkeley maintains trees as an integral component of the urban infrastructure. Research indicates that healthy trees can mitigate impacts associated with the built environment by reducing stormwater runoff, energy consumption, and air pollutants. Put simply, trees improve urban life, making Berkeley...

Optical Design of the far Ultraviolet Imaging Spectrograph

Directory of Open Access Journals (Sweden)

K. S. Ryu

1998-12-01

Full Text Available We present the design specifications and the performance estimation of the FUVS (Far Ultraviolet Spectrograph proposed for the observations of aurora, day/night airglow and astronomical objects on small satelltes in the spectral range of . The design of FUVS is carried out with the full consideration of optical characteristics of the grating and the aspheric substrate. Two independent methods, ray-tracing and the wave front aberration theory, are employed to estimate the performance of the optical design and it is verified that both procedures yield the resolution of in the entire spectral range. MDF (Minimum Detectable Flux is also estimated using the known characteristics of the reflecting material and MCP, to study the feasibility of detection for faint emission lines from the hot interstellar plasmas. The results give that the observations from 1 day to 1 week, depending on the line intensity, can detect such faint emission lines from diffuse interstellar plasmas.

First mesospheric wind images using the Michelson interferometer for airglow dynamics imaging.

Science.gov (United States)

Langille, J A; Ward, W E; Nakamura, T

2016-12-10

The Michelson interferometer for airglow dynamics imaging (MIADI) is a ground-based instrument that combines an imaging capability with the Doppler Michelson interferometry in order to remotely detect motions in the mesopause region using spectrally isolated airglow emissions: the O(S1) emission at 557.73 nm and the OH (6, 2) P1 (2) at 839.918 nm. A measurement and analysis approach has been developed that allows simultaneous images of the line-of-sight Doppler wind field and irradiance field to be obtained. A working field instrument was installed and tested at a field site outside Fredericton, NB (45.96 N, 66.65 W) during the summer of 2014. Successful measurements over a 6 h period were obtained on 31 July 2014. This paper describes the MIADI measurement and analysis approach and presents the work that has been done to extract images of the line-of-sight Doppler wind field and irradiances from these observations. The imaging capability is validated by identifying the presence of large-scale and small-scale geophysical perturbations in the images.

Development of a liquid tin microjet target for an efficient laser-produced plasma extreme ultraviolet source

Science.gov (United States)

Higashiguchi, Takeshi; Hamada, Masaya; Kubodera, Shoichi

2007-03-01

A regenerative tin liquid microjet target was developed for a high average power extreme ultraviolet (EUV) source. The diameter of the target was smaller than 160 μm and good vacuum lower than 0.5 Pa was maintained during the operation. A maximum EUV conversion efficiency of 1.8% at the Nd:yttrium-aluminum-garnet laser intensity of around 2×1011 W/cm2 with a spot diameter of 175 μm (full width at half maximum) was observed. The angular distribution of the EUV emission remained almost isotropic, whereas suprathermal ions mainly emerged toward the target normal.

Development of a liquid tin microjet target for an efficient laser-produced plasma extreme ultraviolet source

International Nuclear Information System (INIS)

Higashiguchi, Takeshi; Hamada, Masaya; Kubodera, Shoichi

2007-01-01

A regenerative tin liquid microjet target was developed for a high average power extreme ultraviolet (EUV) source. The diameter of the target was smaller than 160 μm and good vacuum lower than 0.5 Pa was maintained during the operation. A maximum EUV conversion efficiency of 1.8% at the Nd:yttrium-aluminum-garnet laser intensity of around 2x10 11 W/cm 2 with a spot diameter of 175 μm (full width at half maximum) was observed. The angular distribution of the EUV emission remained almost isotropic, whereas suprathermal ions mainly emerged toward the target normal

Development of a liquid tin microjet target for an efficient laser-produced plasma extreme ultraviolet source.

Science.gov (United States)

Higashiguchi, Takeshi; Hamada, Masaya; Kubodera, Shoichi

2007-03-01

A regenerative tin liquid microjet target was developed for a high average power extreme ultraviolet (EUV) source. The diameter of the target was smaller than 160 microm and good vacuum lower than 0.5 Pa was maintained during the operation. A maximum EUV conversion efficiency of 1.8% at the Nd:yttrium-aluminum-garnet laser intensity of around 2 x 10(11) Wcm(2) with a spot diameter of 175 microm (full width at half maximum) was observed. The angular distribution of the EUV emission remained almost isotropic, whereas suprathermal ions mainly emerged toward the target normal.

Enhancement of conversion efficiency of extreme ultraviolet radiation from a liquid aqueous solution microjet target by use of dual laser pulses

Science.gov (United States)

Higashiguchi, Takeshi; Dojyo, Naoto; Hamada, Masaya; Kawasaki, Keita; Sasaki, Wataru; Kubodera, Shoichi

2006-03-01

We demonstrated a debris-free, efficient laser-produced plasma extreme ultraviolet (EUV) source by use of a regenerative liquid microjet target containing tin-dioxide (SnO II) nano-particles. By using a low SnO II concentration (6%) solution and dual laser pulses for the plasma control, we observed the EUV conversion efficiency of 1.2% with undetectable debris.

Technique for rapid at-wavelength inspection of extreme ultraviolet mask blanks

International Nuclear Information System (INIS)

Spector, S. J.; White, D. L.; Tennant, D. M.; Ocola, L. E.; Novembre, A. E.; Peabody, M. L.; Wood, O. R. II

1999-01-01

We have developed two new methods for at-wavelength inspection of mask blanks for extreme-ultraviolet (EUV) lithography. In one method an EUV photoresist is applied directly to a mask blank which is then flood exposed with EUV light and partially developed. In the second method, the photoresist is applied to an EUV transparent membrane that is placed in close proximity to the mask and then exposed and developed. Both reflectivity defects and phase defects alter the exposure of the resist, resulting in mounds of resist at defect sites that can then be located by visual inspection. In the direct application method, a higher contrast resist was shown to increase the height of the mounds, thereby improving the sensitivity of the technique. In the membrane method, a holographic technique was used to reconstruct an image of the mask, revealing the presence of very small defects, approximately 0.2 μm in size. The demonstrated clean transfer of phase and amplitude defects to resist features on a membrane will be important when flagging defects in an automatic inspection tool. (c) 1999 American Vacuum Society

Kr photoionized plasma induced by intense extreme ultraviolet pulses

Science.gov (United States)

Bartnik, A.; Wachulak, P.; Fiedorowicz, H.; Skrzeczanowski, W.

2016-04-01

Irradiation of any gas with an intense EUV (extreme ultraviolet) radiation beam can result in creation of photoionized plasmas. The parameters of such plasmas can be significantly different when compared with those of the laser produced plasmas (LPP) or discharge plasmas. In this work, the photoionized plasmas were created in a krypton gas irradiated using an LPP EUV source operating at a 10 Hz repetition rate. The Kr gas was injected into the vacuum chamber synchronously with the EUV radiation pulses. The EUV beam was focused onto a Kr gas stream using an axisymmetrical ellipsoidal collector. The resulting low temperature Kr plasmas emitted electromagnetic radiation in the wide spectral range. The emission spectra were measured either in the EUV or an optical range. The EUV spectrum was dominated by emission lines originating from Kr III and Kr IV ions, and the UV/VIS spectra were composed from Kr II and Kr I lines. The spectral lines recorded in EUV, UV, and VIS ranges were used for the construction of Boltzmann plots to be used for the estimation of the electron temperature. It was shown that for the lowest Kr III and Kr IV levels, the local thermodynamic equilibrium (LTE) conditions were not fulfilled. The electron temperature was thus estimated based on Kr II and Kr I species where the partial LTE conditions could be expected.

NEW SOLAR EXTREME-ULTRAVIOLET IRRADIANCE OBSERVATIONS DURING FLARES

International Nuclear Information System (INIS)

Woods, Thomas N.; Hock, Rachel; Eparvier, Frank; Jones, Andrew R.; Chamberlin, Phillip C.; Klimchuk, James A.; Didkovsky, Leonid; Judge, Darrell; Mariska, John; Warren, Harry; Schrijver, Carolus J.; Webb, David F.; Bailey, Scott; Tobiska, W. Kent

2011-01-01

New solar extreme-ultraviolet (EUV) irradiance observations from the NASA Solar Dynamics Observatory (SDO) EUV Variability Experiment provide full coverage in the EUV range from 0.1 to 106 nm and continuously at a cadence of 10 s for spectra at 0.1 nm resolution and even faster, 0.25 s, for six EUV bands. These observations can be decomposed into four distinct characteristics during flares. First, the emissions that dominate during the flare's impulsive phase are the transition region emissions, such as the He II 30.4 nm. Second, the hot coronal emissions above 5 MK dominate during the gradual phase and are highly correlated with the GOES X-ray. A third flare characteristic in the EUV is coronal dimming, seen best in the cool corona, such as the Fe IX 17.1 nm. As the post-flare loops reconnect and cool, many of the EUV coronal emissions peak a few minutes after the GOES X-ray peak. One interesting variation of the post-eruptive loop reconnection is that warm coronal emissions (e.g., Fe XVI 33.5 nm) sometimes exhibit a second large peak separated from the primary flare event by many minutes to hours, with EUV emission originating not from the original flare site and its immediate vicinity, but rather from a volume of higher loops. We refer to this second peak as the EUV late phase. The characterization of many flares during the SDO mission is provided, including quantification of the spectral irradiance from the EUV late phase that cannot be inferred from GOES X-ray diagnostics.

Environmental Survey preliminary report, Lawrence Berkeley Laboratory, Berkeley, California

International Nuclear Information System (INIS)

1988-07-01

The purpose of this report is to present the preliminary findings made during the Environmental Survey, February 22--29, 1988, at the US Department of Energy (DOE) Lawrence Berkeley Laboratory (LBL) in Berkeley, California. The University of California operates the LBL facility for DOE. The LBL Survey is part of the larger DOE-wide Environmental Survey announced by Secretary John S. Herrington on September 18, 1985. The purpose of this effort is to identify, via ''no fault'' baseline Surveys, existing environmental problems and areas of environmental risk at DOE facilities, and to rank them on a DOE wide basis. This ranking will enable DOE to more effectively establish priorities for addressing environmental problems and allocate the resources necessary to correct them. Because the Survey is ''no fault'' and is not an ''audit,'' it is not designed to identify specific isolated incidents of noncompliance or to analyze environmental management practices. Such incidents and/or management practices will, however, be used in the Survey as a means of identifying existing and potential environmental problems. The LBL Survey was conducted by a multidisciplinary team of technical specialists headed and managed by a Team Leader and Assistant Team Leader from DOE's Office of Environmental Audit. A complete list of the LBL Survey participants and their affiliations is provided in Appendix A. 80 refs., 27 figs., 37 tabs

Environmental Survey preliminary report, Lawrence Berkeley Laboratory, Berkeley, California

Energy Technology Data Exchange (ETDEWEB)

1988-07-01

The purpose of this report is to present the preliminary findings made during the Environmental Survey, February 22--29, 1988, at the US Department of Energy (DOE) Lawrence Berkeley Laboratory (LBL) in Berkeley, California. The University of California operates the LBL facility for DOE. The LBL Survey is part of the larger DOE-wide Environmental Survey announced by Secretary John S. Herrington on September 18, 1985. The purpose of this effort is to identify, via no fault'' baseline Surveys, existing environmental problems and areas of environmental risk at DOE facilities, and to rank them on a DOE wide basis. This ranking will enable DOE to more effectively establish priorities for addressing environmental problems and allocate the resources necessary to correct them. Because the Survey is no fault'' and is not an audit,'' it is not designed to identify specific isolated incidents of noncompliance or to analyze environmental management practices. Such incidents and/or management practices will, however, be used in the Survey as a means of identifying existing and potential environmental problems. The LBL Survey was conducted by a multidisciplinary team of technical specialists headed and managed by a Team Leader and Assistant Team Leader from DOE's Office of Environmental Audit. A complete list of the LBL Survey participants and their affiliations is provided in Appendix A. 80 refs., 27 figs., 37 tabs.

A giant planet undergoing extreme-ultraviolet irradiation by its hot massive-star host.

Science.gov (United States)

Gaudi, B Scott; Stassun, Keivan G; Collins, Karen A; Beatty, Thomas G; Zhou, George; Latham, David W; Bieryla, Allyson; Eastman, Jason D; Siverd, Robert J; Crepp, Justin R; Gonzales, Erica J; Stevens, Daniel J; Buchhave, Lars A; Pepper, Joshua; Johnson, Marshall C; Colon, Knicole D; Jensen, Eric L N; Rodriguez, Joseph E; Bozza, Valerio; Novati, Sebastiano Calchi; D'Ago, Giuseppe; Dumont, Mary T; Ellis, Tyler; Gaillard, Clement; Jang-Condell, Hannah; Kasper, David H; Fukui, Akihiko; Gregorio, Joao; Ito, Ayaka; Kielkopf, John F; Manner, Mark; Matt, Kyle; Narita, Norio; Oberst, Thomas E; Reed, Phillip A; Scarpetta, Gaetano; Stephens, Denice C; Yeigh, Rex R; Zambelli, Roberto; Fulton, B J; Howard, Andrew W; James, David J; Penny, Matthew; Bayliss, Daniel; Curtis, Ivan A; DePoy, D L; Esquerdo, Gilbert A; Gould, Andrew; Joner, Michael D; Kuhn, Rudolf B; Labadie-Bartz, Jonathan; Lund, Michael B; Marshall, Jennifer L; McLeod, Kim K; Pogge, Richard W; Relles, Howard; Stockdale, Christopher; Tan, T G; Trueblood, Mark; Trueblood, Patricia

2017-06-22

The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extrasolar planets now known, only six have been found that transit hot, A-type stars (with temperatures of 7,300-10,000 kelvin), and no planets are known to transit the even hotter B-type stars. For example, WASP-33 is an A-type star with a temperature of about 7,430 kelvin, which hosts the hottest known transiting planet, WASP-33b (ref. 1); the planet is itself as hot as a red dwarf star of type M (ref. 2). WASP-33b displays a large heat differential between its dayside and nightside, and is highly inflated-traits that have been linked to high insolation. However, even at the temperature of its dayside, its atmosphere probably resembles the molecule-dominated atmospheres of other planets and, given the level of ultraviolet irradiation it experiences, its atmosphere is unlikely to be substantially ablated over the lifetime of its star. Here we report observations of the bright star HD 195689 (also known as KELT-9), which reveal a close-in (orbital period of about 1.48 days) transiting giant planet, KELT-9b. At approximately 10,170 kelvin, the host star is at the dividing line between stars of type A and B, and we measure the dayside temperature of KELT-9b to be about 4,600 kelvin. This is as hot as stars of stellar type K4 (ref. 5). The molecules in K stars are entirely dissociated, and so the primary sources of opacity in the dayside atmosphere of KELT-9b are probably atomic metals. Furthermore, KELT-9b receives 700 times more extreme-ultraviolet radiation (that is, with wavelengths shorter than 91.2 nanometres) than WASP-33b, leading to a predicted range of mass-loss rates that could leave the planet largely stripped of its envelope during the main-sequence lifetime of the host star.

Evaluating the Impact of Open Access at Berkeley: Results from the 2015 Survey of Berkeley Research Impact Initiative (BRII) Funding Recipients

Science.gov (United States)

Teplitzky, Samantha; Phillips, Margaret

2016-01-01

The Berkeley Research Impact Initiative (BRII) was one of the first campus-based open access (OA) funds to be established in North America and one of the most active, distributing more than $244,000 to support University of California (UC) Berkeley authors. In April 2015, we conducted a qualitative study of 138 individuals who had received BRII…

FIBRILLAR CHROMOSPHERIC SPICULE-LIKE COUNTERPARTS TO AN EXTREME-ULTRAVIOLET AND SOFT X-RAY BLOWOUT CORONAL JET

International Nuclear Information System (INIS)

Sterling, Alphonse C.; Moore, Ronald L.; Harra, Louise K.

2010-01-01

We observe an erupting jet feature in a solar polar coronal hole, using data from Hinode/Solar Optical Telescope (SOT), Extreme Ultraviolet Imaging Spectrometer (EIS), and X-Ray Telescope (XRT), with supplemental data from STEREO/EUVI. From extreme-ultraviolet (EUV) and soft X-ray (SXR) images we identify the erupting feature as a blowout coronal jet: in SXRs it is a jet with a bright base, and in EUV it appears as an eruption of relatively cool (∼50,000 K) material of horizontal size scale ∼30'' originating from the base of the SXR jet. In SOT Ca II H images, the most pronounced analog is a pair of thin (∼1'') ejections at the locations of either of the two legs of the erupting EUV jet. These Ca II features eventually rise beyond 45'', leaving the SOT field of view, and have an appearance similar to standard spicules except that they are much taller. They have velocities similar to that of 'type II' spicules, ∼100 km s -1 , and they appear to have spicule-like substructures splitting off from them with horizontal velocity ∼50 km s -1 , similar to the velocities of splitting spicules measured by Sterling et al. Motions of splitting features and of other substructures suggest that the macroscopic EUV jet is spinning or unwinding as it is ejected. This and earlier work suggest that a subpopulation of Ca II type II spicules are the Ca II manifestation of portions of larger scale erupting magnetic jets. A different subpopulation of type II spicules could be blowout jets occurring on a much smaller horizontal size scale than the event we observe here.

Extreme-ultraviolet limb spectra of a prominence observed from SKYLAB

International Nuclear Information System (INIS)

Mariska, J.T.; Doschek, G.A.; Feldman, U.

1979-01-01

Line profiles of extreme ultraviolet emission lines observed in a solar prominence at positions above the white-light limb with the NRL slit spectrograph on Skylab are discussed. Absolute line intensities and full widths at half-maximum are presented for lines formed over the temperature range approx.1 x 10 4 to 2.2 x 10 5 K. The volume emission measures calculated using resonance line intensities are greater than quiet-Sun emission measures at the same height above the limb and indicate a somewhat different distribution of material with temperature in the prominence compared to the quiet-Sun emission measure at +8''. Electron densities in the prominence determined using the calculated emission measures and the intensities of density-sensitive intersystem lines are between the quiet-Sun electron density and half the quiet-Sun electron density. Random mass-motion velocities calculated from the measured full widths at half-maximum show a range of velocities. For T/sub e/> or approx. =4 x 10 4 K, the nonthermal velocity decreases with increasing height in the prominence. For T/sub e/ 4 K, the calculated mass motions are near zero. From the He II 1640 A line profile we derive an average temperature of 27,000 K for the region in which He II is emitted

C. Judson King of UC Berkeley

Energy Technology Data Exchange (ETDEWEB)

Prausnitz, John

2005-06-01

In the middle of the UC Berkeley campus, next to the Main Library, South Hall is the last surviving building from the original campus, founded about 135 years ago. A tiny tree-shaded appendix to this venerated classical building houses Berkeley's Center for Studies in Higher Education, directed by C. Judson King, former Provost and Senior Vice President--Academic Affairs of the ten-campus University of California and long-time Professor of Chemical Engineering at Berkeley. Jud came to Berkeley in 1963 as assistant professor of chemical engineering, following receipt of a doctor's degree from MIT and a subsequent short appointment as director of the MIT chemical engineering practice school station at what was then Esso (now Exxon) in New Jersey. His undergraduate degree is from Yale. Starting with his MIT doctoral dissertation on gas absorption, Jud has devoted much of his professional career to separation processes. His teaching and research activities have been primarily concerned with separation of mixtures with emphasis on liquid-liquid extraction and drying. As a consultant to Procter and Gamble, he contributed to the technology of making instant coffee. His life-long activities in hiking and camping stimulated Jud's interest in the manufacture of freeze-dried foods (e.g. turkey meat) to minimize the weight of his hiking back-pack. Jud is internationally known not only for his many research publications but even more, for his acclaimed textbook ''Separation Processses'' (McGraw-Hill, second edition 1980) that is used in standard chemical engineering courses in the US and abroad.

Extreme Ultraviolet Solar Images Televised In-Flight with a Rocket-Borne SEC Vidicon System.

Science.gov (United States)

Tousey, R; Limansky, I

1972-05-01

A TV image of the entire sun while an importance 2N solar flare was in progress was recorded in the extreme ultraviolet (XUV) radiation band 171-630 A and transmitted to ground from an Aerobee-150 rocket on 4 November 1969 using S-band telemetry. The camera tube was a Westinghouse Electric Corporation SEC vidicon, with its fiber optic faceplate coated with an XUV to visible conversion layer of p-quaterphenyl. The XUV passband was produced by three 1000-A thick aluminum filters in series together with the platinized reflecting surface of the off-axis paraboloid that imaged the sun. A number of images were recorded with integration times between 1/30 see and 2 sec. Reconstruction of pictures was enhanced by combining several to reduce the noise.

Invisible marking system by extreme ultraviolet radiation: the new frontier for anti-counterfeiting tags

International Nuclear Information System (INIS)

Lazzaro, P. Di; Bollanti, S.; Flora, F.; Mezi, L.; Murra, D.; Torre, A.; Bonfigli, F.; Montereali, R.M.; Vincenti, M.A.

2016-01-01

We present a marking technology which uses extreme ultraviolet radiation to write invisible patterns on tags based on alkali fluoride thin films. The shape of the pattern is pre-determined by a mask (in the case of contact lithography) or by a suitable mirror (projection lithography). Tags marked using this method offer a much better protection against fakes than currently available anti-counterfeiting techniques. The complexity and cost of this technology can be tailored to the value of the good to be protected, leaving, on the other hand, the specific reading technique straightforward. So far, we have exploited our invisible marking to tag artworks, identity cards, electrical components, and containers of radioactive wastes. Advantages and limits of this technology are discussed in comparison with the anti-counterfeiting systems available in the market.

Response of the mesopause airglow to solar activity inferred from measurements at Zvenigorod, Russia

Directory of Open Access Journals (Sweden)

N. Pertsev

2008-05-01

Full Text Available Ground-based spectrographical observations of infrared emissions of the mesopause region have been made at Zvenigorod Observatory (56 N, 37 E, located near Moscow, Russia, for 670 nights of 2000–2006. The characteristics of the hydroxyl and molecular oxygen (865 nm airglow, heights of which correspond to 87 and 94 km, are analyzed for finding their response to solar activity. The measured data exhibit a response to the F_10.7 solar radio flux change, which is 30%–40%/100 sfu in intensities of the emissions and about 4.5 K/100 sfu in hydroxyl temperature. Seasonal variations of the airglow response to solar activity are observed. In winter it is more significant than in summer. Mechanisms that may provide an explanation of the solar influence on intensities of the emissions and temperature are considered. Radiative processes not involving atmospheric dynamics appear insufficient to explain the observed effect.

Response of the mesopause airglow to solar activity inferred from measurements at Zvenigorod, Russia

Directory of Open Access Journals (Sweden)

N. Pertsev

2008-05-01

Full Text Available Ground-based spectrographical observations of infrared emissions of the mesopause region have been made at Zvenigorod Observatory (56 N, 37 E, located near Moscow, Russia, for 670 nights of 2000–2006. The characteristics of the hydroxyl and molecular oxygen (865 nm airglow, heights of which correspond to 87 and 94 km, are analyzed for finding their response to solar activity. The measured data exhibit a response to the F10.7 solar radio flux change, which is 30%–40%/100 sfu in intensities of the emissions and about 4.5 K/100 sfu in hydroxyl temperature. Seasonal variations of the airglow response to solar activity are observed. In winter it is more significant than in summer. Mechanisms that may provide an explanation of the solar influence on intensities of the emissions and temperature are considered. Radiative processes not involving atmospheric dynamics appear insufficient to explain the observed effect.

Cold-target recoil-ion momentum spectroscopy for diagnostics of high harmonics of the extreme-ultraviolet free-electron laser light source at SPring-8

International Nuclear Information System (INIS)

Liu, X.-J.; Fukuzawa, H.; Pruemper, G.; Ueda, K.; Okunishi, M.; Shimada, K.; Motomura, K.; Saito, N.; Iwayama, H.; Nagaya, K.; Yao, M.; Rudenko, A.; Ullrich, J.; Foucar, L.; Czasch, A.; Schmidt-Boecking, H.; Doerner, R.; Nagasono, M.; Higashiya, A.; Yabashi, M.

2009-01-01

We have developed a cold-target recoil-ion momentum spectroscopy apparatus dedicated to the experiments using the extreme-ultraviolet light pulses at the free-electron laser facility, SPring-8 Compact SASE Source test accelerator, in Japan and used it to measure spatial distributions of fundamental, second, and third harmonics at the end station.

Thermal conduction properties of Mo/Si multilayers for extreme ultraviolet optics

Science.gov (United States)

Bozorg-Grayeli, Elah; Li, Zijian; Asheghi, Mehdi; Delgado, Gil; Pokrovsky, Alexander; Panzer, Matthew; Wack, Daniel; Goodson, Kenneth E.

2012-10-01

Extreme ultraviolet (EUV) lithography requires nanostructured optical components, whose reliability can be influenced by radiation absorption and thermal conduction. Thermal conduction analysis is complicated by sub-continuum electron and phonon transport and the lack of thermal property data. This paper measures and interprets thermal property data, and their evolution due to heating exposure, for Mo/Si EUV mirrors with 6.9 nm period and Mo/Si thickness ratios of 0.4/0.6 and 0.6/0.4. We use time-domain thermoreflectance and the 3ω method to estimate the thermal resistance between the Ru capping layer and the Mo/Si multilayers (RRu-Mo/Si = 1.5 m2 K GW-1), as well as the out-of-plane thermal conductivity (kMo/Si 1.1 W m-1 K-1) and thermal anisotropy (η = 13). This work also reports the impact of annealing on thermal conduction in a co-deposited MoSi2 layer, increasing the thermal conductivity from 1.7 W m-1 K-1 in the amorphous phase to 2.8 W m-1 K-1 in the crystalline phase.

Spatial-Resolved Measurement and Analysis of Extreme-Ultraviolet Emission Spectra from Laser-Produced Al Plasmas

International Nuclear Information System (INIS)

Cao Shi-Quan; Su Mao-Gen; Sun Dui-Xiong; Min Qi; Dong Chen-Zhong

2016-01-01

Extreme ultraviolet emission from laser-produced Al plasma is experimentally and theoretically investigated. Spatial-evolution emission spectra are measured by using the spatio-temporally resolved laser produced plasma technique. Based on the assumptions of a normalized Boltzmann distribution among the excited states and a steady-state collisional-radiative model, we succeed in reproducing the spectra at different detection positions, which are in good agreement with experiments. The decay curves about the electron temperature and electron density, as well as the fractions of individual Al ions and average ionization stage with increasing the detection distance are obtained by comparison with the experimental measurements. These parameters are critical points for deeply understanding the expanding and cooling of laser produced plasmas in vacuum. (paper)

Berkeley Lab Laser Accelerator (BELLA) facility

Data.gov (United States)

Federal Laboratory Consortium — The Berkeley Lab Laser Accelerator (BELLA) facility (formerly LOASIS) develops advanced accelerators and radiation sources. High gradient (1-100 GV/m) laser-plasma...

USING HINODE/EXTREME-ULTRAVIOLET IMAGING SPECTROMETER TO CONFIRM A SEISMOLOGICALLY INFERRED CORONAL TEMPERATURE

International Nuclear Information System (INIS)

Marsh, M. S.; Walsh, R. W.

2009-01-01

The Extreme-Ultraviolet Imaging Spectrometer on board the HINODE satellite is used to examine the loop system described in Marsh et al. by applying spectroscopic diagnostic methods. A simple isothermal mapping algorithm is applied to determine where the assumption of isothermal plasma may be valid, and the emission measure locii technique is used to determine the temperature profile along the base of the loop system. It is found that, along the base, the loop has a uniform temperature profile with a mean temperature of 0.89 ± 0.09 MK which is in agreement with the temperature determined seismologically in Marsh et al., using observations interpreted as the slow magnetoacoustic mode. The results further strengthen the slow mode interpretation, propagation at a uniform sound speed, and the analysis method applied in Marsh et al. It is found that it is not possible to discriminate between the slow mode phase speed and the sound speed within the precision of the present observations.

Design considerations of 10 kW-scale, extreme ultraviolet SASE FEL for lithography

CERN Document Server

Pagani, C; Schneidmiller, E A; Yurkov, M V

2001-01-01

The semiconductor industry growth is driven to a large extent by steady advancements in microlithography. According to the newly updated industry road map, the 70 nm generation is anticipated to be available in the year 2008. However, the path to get there is not clear. The problem of construction of extreme ultraviolet (EUV) quantum lasers for lithography is still unsolved: progress in this field is rather moderate and we cannot expect a significant breakthrough in the near future. Nevertheless, there is clear path for optical lithography to take us to sub-100 nm dimensions. Theoretical and experimental work in Self-Amplified Spontaneous Emission (SASE) Free Electron Lasers (FEL) physics and the physics of superconducting linear accelerators over the last 10 years has pointed to the possibility of the generation of high-power optical beams with laser-like characteristics in the EUV spectral range. Recently, there have been important advances in demonstrating a high-gain SASE FEL at 100 nm wavelength (J. Andr...

Ultimate waveform reproducibility of extreme-ultraviolet pulses by high-harmonic generation in quartz

Science.gov (United States)

Garg, M.; Kim, H. Y.; Goulielmakis, E.

2018-05-01

Optical waveforms of light reproducible with subcycle precision underlie applications of lasers in ultrafast spectroscopies, quantum control of matter and light-based signal processing. Nonlinear upconversion of optical pulses via high-harmonic generation in gas media extends these capabilities to the extreme ultraviolet (EUV). However, the waveform reproducibility of the generated EUV pulses in gases is inherently sensitive to intensity and phase fluctuations of the driving field. We used photoelectron interferometry to study the effects of intensity and carrier-envelope phase of an intense single-cycle optical pulse on the field waveform of EUV pulses generated in quartz nanofilms, and contrasted the results with those obtained in gas argon. The EUV waveforms generated in quartz were found to be virtually immune to the intensity and phase of the driving field, implying a non-recollisional character of the underlying emission mechanism. Waveform-sensitive photonic applications and precision measurements of fundamental processes in optics will benefit from these findings.

Extreme ultraviolet spectroscopy of low pressure helium microwave driven discharges

Science.gov (United States)

Espinho, Susana; Felizardo, Edgar; Tatarova, Elena; Alves, Luis Lemos

2016-09-01

Surface wave driven discharges are reliable plasma sources that can produce high levels of vacuum and extreme ultraviolet radiation (VUV and EUV). The richness of the emission spectrum makes this type of discharge a possible alternative source in EUV/VUV radiation assisted applications. However, due to challenging experimental requirements, publications concerning EUV radiation emitted by microwave plasmas are scarce and a deeper understanding of the main mechanisms governing the emission of radiation in this spectral range is required. To this end, the EUV radiation emitted by helium microwave driven plasmas operating at 2.45 GHz has been studied for low pressure conditions. Spectral lines from excited helium atoms and ions were detected via emission spectroscopy in the EUV/VUV regions. Novel data concerning the spectral lines observed in the 23 - 33 nm wavelength range and their intensity behaviour with variation of the discharge operational conditions are presented. The intensity of all the spectral emissions strongly increases with the microwave power delivered to the plasma up to 400 W. Furthermore, the intensity of all the ion spectral emissions in the EUV range decreases by nearly one order of magnitude as the pressure was raised from 0.2 to 0.5 mbar. Work funded by FCT - Fundacao para a Ciencia e a Tecnologia, under Project UID/FIS/50010/2013 and grant SFRH/BD/52412/2013 (PD-F APPLAuSE).

Long-term ozone decline and its effect on night airglow intensity of Li ...

Indian Academy of Sciences (India)

A critical analysis has been made on the long-term yearly and seasonal variations of ozone concentration at Varanasi (25°N, 83°E), India and Halley Bay (76°S, 27°W), a British Antarctic Service Station. The effect of O3 depletion on night airglow emission of Li 6708 Å line at Varanasi and Halley Bay has been studied.

THE YOUNG OPEN CLUSTER BERKELEY 55

Energy Technology Data Exchange (ETDEWEB)

Negueruela, Ignacio; Marco, Amparo, E-mail: ignacio.negueruela@ua.es, E-mail: amparo.marco@ua.es [Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Senal, Universidad de Alicante, Apdo. 99, E-03080 Alicante (Spain)

2012-02-15

We present UBV photometry of the highly reddened and poorly studied open cluster Berkeley 55, revealing an important population of B-type stars and several evolved stars of high luminosity. Intermediate-resolution far-red spectra of several candidate members confirm the presence of one F-type supergiant and six late supergiants or bright giants. The brightest blue stars are mid-B giants. Spectroscopic and photometric analyses indicate an age 50 {+-} 10 Myr. The cluster is located at a distance d Almost-Equal-To 4 kpc, consistent with other tracers of the Perseus Arm in this direction. Berkeley 55 is thus a moderately young open cluster with a sizable population of candidate red (super)giant members, which can provide valuable information about the evolution of intermediate-mass stars.

Spatio-temporal coherence of free-electron laser radiation in the extreme ultraviolet determined by a Michelson interferometer

Energy Technology Data Exchange (ETDEWEB)

Hilbert, V.; Rödel, C.; Zastrau, U., E-mail: ulf.zastrau@uni-jena.de [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Brenner, G.; Düsterer, S.; Dziarzhytski, S.; Harmand, M.; Przystawik, A.; Redlin, H.; Toleikis, S. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Döppner, T.; Ma, T. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Fletcher, L. [Department of Physics, University of California, Berkeley, California 94720 (United States); Förster, E. [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena (Germany); Glenzer, S. H.; Lee, H. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Hartley, N. J. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Kazak, L.; Komar, D.; Skruszewicz, S. [Institut für Physik, Universität Rostock, 18051 Rostock (Germany); and others

2014-09-08

A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties of monochromatized FEL pulses at 13.5 nm using a Michelson interferometer. A temporal coherence time of (59±8) fs has been determined, which is in good agreement with the spectral bandwidth given by the monochromator. Moreover, the spatial coherence in vertical direction amounts to about 15% of the beam diameter and about 12% in horizontal direction. The feasibility of measuring spatio-temporal coherence properties of XUV FEL radiation using interferometric techniques advances machine operation and experimental studies significantly.

BERKELEY/STANFORD: B factory plans

International Nuclear Information System (INIS)

Anon.

1991-01-01

For the past several years, accelerator physicists at Lawrence Berkeley Laboratory (LBL) and the Stanford Linear Accelerator Center (SLAC) have been involved in the design of an Asymmetric B Factory to be sited in the tunnel of the PEP electron-positron collider at SLAC

THE HIGH-RESOLUTION EXTREME-ULTRAVIOLET SPECTRUM OF N{sub 2} BY ELECTRON IMPACT

Energy Technology Data Exchange (ETDEWEB)

Heays, A. N. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Ajello, J. M.; Aguilar, A. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Lewis, B. R.; Gibson, S. T., E-mail: heays@strw.leidenuniv.nl [Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)

2014-04-01

We have analyzed high-resolution (FWHM = 0.2 Å) extreme-ultraviolet (EUV, 800-1350 Å) laboratory emission spectra of molecular nitrogen excited by an electron impact at 20 and 100 eV under (mostly) optically thin, single-scattering experimental conditions. A total of 491 emission features were observed from N{sub 2} electronic-vibrational transitions and atomic N I and N II multiplets and their emission cross sections were measured. Molecular emission was observed at vibrationally excited ground-state levels as high as v'' = 17, from the a {sup 1}Π {sub g} , b {sup 1}Π {sub u} , and b'{sup 1}Σ {sub u} {sup +} excited valence states and the Rydberg series c'{sub n} {sub +1} {sup 1}Σ {sub u} {sup +}, c{sub n} {sup 1}Π {sub u} , and o{sub n} {sup 1}Π {sub u} for n between 3 and 9. The frequently blended molecular emission bands were disentangled with the aid of a sophisticated and predictive quantum-mechanical model of excited states that includes the strong coupling between valence and Rydberg electronic states and the effects of predissociation. Improved model parameters describing electronic transition moments were obtained from the experiment and allowed for a reliable prediction of the vibrationally summed electronic emission cross section, including an extrapolation to unobserved emission bands and those that are optically thick in the experimental spectra. Vibrationally dependent electronic excitation functions were inferred from a comparison of emission features following 20 and 100 eV electron-impact collisional excitation. The electron-impact-induced fluorescence measurements are compared with Cassini Ultraviolet Imaging Spectrograph observations of emissions from Titan's upper atmosphere.

MANGO Imager Network Observations of Geomagnetic Storm Impact on Midlatitude 630 nm Airglow Emissions

Science.gov (United States)

Kendall, E. A.; Bhatt, A.

2017-12-01

The Midlatitude Allsky-imaging Network for GeoSpace Observations (MANGO) is a network of imagers filtered at 630 nm spread across the continental United States. MANGO is used to image large-scale airglow and aurora features and observes the generation, propagation, and dissipation of medium and large-scale wave activity in the subauroral, mid and low-latitude thermosphere. This network consists of seven all-sky imagers providing continuous coverage over the United States and extending south into Mexico. This network sees high levels of medium and large scale wave activity due to both neutral and geomagnetic storm forcing. The geomagnetic storm observations largely fall into two categories: Stable Auroral Red (SAR) arcs and Large-scale traveling ionospheric disturbances (LSTIDs). In addition, less-often observed effects include anomalous airglow brightening, bright swirls, and frozen-in traveling structures. We will present an analysis of multiple events observed over four years of MANGO network operation. We will provide both statistics on the cumulative observations and a case study of the "Memorial Day Storm" on May 27, 2017.

Desorption/ablation of lithium fluoride induced by extreme ultraviolet laser radiation

Directory of Open Access Journals (Sweden)

Blejchař Tomáš

2016-06-01

Full Text Available The availability of reliable modeling tools and input data required for the prediction of surface removal rate from the lithium fluoride targets irradiated by the intense photon beams is essential for many practical aspects. This study is motivated by the practical implementation of soft X-ray (SXR or extreme ultraviolet (XUV lasers for the pulsed ablation and thin film deposition. Specifically, it is focused on quantitative description of XUV laser-induced desorption/ablation from lithium fluoride, which is a reference large band-gap dielectric material with ionic crystalline structure. Computational framework was proposed and employed here for the reconstruction of plume expansion dynamics induced by the irradiation of lithium fluoride targets. The morphology of experimentally observed desorption/ablation craters were reproduced using idealized representation (two-zone approximation of the laser fluence profile. The calculation of desorption/ablation rate was performed using one-dimensional thermomechanic model (XUV-ABLATOR code taking into account laser heating and surface evaporation of the lithium fluoride target occurring on a nanosecond timescale. This step was followed by the application of two-dimensional hydrodynamic solver for description of laser-produced plasma plume expansion dynamics. The calculated plume lengths determined by numerical simulations were compared with a simple adiabatic expansion (blast-wave model.

Low-debris, efficient laser-produced plasma extreme ultraviolet source by use of a regenerative liquid microjet target containing tin dioxide (SnO2) nanoparticles

Science.gov (United States)

Higashiguchi, Takeshi; Dojyo, Naoto; Hamada, Masaya; Sasaki, Wataru; Kubodera, Shoichi

2006-05-01

We demonstrated a low-debris, efficient laser-produced plasma extreme ultraviolet (EUV) source by use of a regenerative liquid microjet target containing tin-dioxide (SnO2) nanoparticles. By using a low SnO2 concentration (6%) solution and dual laser pulses for the plasma control, we observed the EUV conversion efficiency of 1.2% with undetectable debris.

Low-debris, efficient laser-produced plasma extreme ultraviolet source by use of a regenerative liquid microjet target containing tin dioxide (SnO2) nanoparticles

International Nuclear Information System (INIS)

Higashiguchi, Takeshi; Dojyo, Naoto; Hamada, Masaya; Sasaki, Wataru; Kubodera, Shoichi

2006-01-01

We demonstrated a low-debris, efficient laser-produced plasma extreme ultraviolet (EUV) source by use of a regenerative liquid microjet target containing tin-dioxide (SnO 2 ) nanoparticles. By using a low SnO 2 concentration (6%) solution and dual laser pulses for the plasma control, we observed the EUV conversion efficiency of 1.2% with undetectable debris

Resist Parameter Extraction from Line-and-Space Patterns of Chemically Amplified Resist for Extreme Ultraviolet Lithography

Science.gov (United States)

Kozawa, Takahiro; Oizumi, Hiroaki; Itani, Toshiro; Tagawa, Seiichi

2010-11-01

The development of extreme ultraviolet (EUV) lithography has progressed owing to worldwide effort. As the development status of EUV lithography approaches the requirements for the high-volume production of semiconductor devices with a minimum line width of 22 nm, the extraction of resist parameters becomes increasingly important from the viewpoints of the accurate evaluation of resist materials for resist screening and the accurate process simulation for process and mask designs. In this study, we demonstrated that resist parameters (namely, quencher concentration, acid diffusion constant, proportionality constant of line edge roughness, and dissolution point) can be extracted from the scanning electron microscopy (SEM) images of patterned resists without the knowledge on the details of resist contents using two types of latest EUV resist.

Micro- and Nanoprocessing of Polymers Using a Laser Plasma Extreme Ultraviolet Source

International Nuclear Information System (INIS)

Bartnik, A.; Fiedorowicz, H.; Jarocki, R.; Kostecki, J.; Rakowski, R.; Szczurek, A.; Szczurek, M.

2010-01-01

Laser plasma with temperature of the order of tens eV can be an efficient source of extreme ultraviolet (EUV). The radiation can be focused using different kind of optics, giving sufficient fluence for some applications. In this work we present results of investigations concerning applications of a laser plasma EUV source based on a double stream gas puff target. The source was equipped with two different grazing incidence collectors. One of them was a multifoil collector, the second one was an axisymmetrical ellipsoidal collector. The multifoil mirror was used mainly in experiments concerning micromachining of organic polymers by direct photo-etching. The experiments were performed for different polymers that were irradiated through a fine metal grid as a contact mask. The smallest element of a pattern structure obtained in this way was 5 μm, while the structure height was 50 μm giving an aspect ratio about 10. The laser-plasma EUV source equipped with the axisymmetrical ellipsoidal collector was used for surface modification of organic polymers and inorganic solids. The surface morphology after irradiation was investigated. Different forms of micro- and nanostructures were obtained depending on material and irradiation conditions. (author)

Mode Conversion of a Solar Extreme-ultraviolet Wave over a Coronal Cavity

Energy Technology Data Exchange (ETDEWEB)

Zong, Weiguo [Key Laboratory of Space Weather, National Center for Space Weather, China Meteorological Administration, Beijing 100081 (China); Dai, Yu, E-mail: ydai@nju.edu.cn [Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing 210023 (China)

2017-01-10

We report on observations of an extreme-ultraviolet (EUV) wave event in the Sun on 2011 January 13 by Solar Terrestrial Relations Observatory and Solar Dynamics Observatory in quadrature. Both the trailing edge and the leading edge of the EUV wave front in the north direction are reliably traced, revealing generally compatible propagation velocities in both perspectives and a velocity ratio of about 1/3. When the wave front encounters a coronal cavity near the northern polar coronal hole, the trailing edge of the front stops while its leading edge just shows a small gap and extends over the cavity, meanwhile getting significantly decelerated but intensified. We propose that the trailing edge and the leading edge of the northward propagating wave front correspond to a non-wave coronal mass ejection component and a fast-mode magnetohydrodynamic wave component, respectively. The interaction of the fast-mode wave and the coronal cavity may involve a mode conversion process, through which part of the fast-mode wave is converted to a slow-mode wave that is trapped along the magnetic field lines. This scenario can reasonably account for the unusual behavior of the wave front over the coronal cavity.

Advanced materials for multilayer mirrors for extreme ultraviolet solar astronomy.

Science.gov (United States)

Bogachev, S A; Chkhalo, N I; Kuzin, S V; Pariev, D E; Polkovnikov, V N; Salashchenko, N N; Shestov, S V; Zuev, S Y

2016-03-20

We provide an analysis of contemporary multilayer optics for extreme ultraviolet (EUV) solar astronomy in the wavelength ranges: λ=12.9-13.3  nm, λ=17-21  nm, λ=28-33  nm, and λ=58.4  nm. We found new material pairs, which will make new spaceborne experiments possible due to the high reflection efficiencies, spectral resolution, and long-term stabilities of the proposed multilayer coatings. In the spectral range λ=13  nm, Mo/Be multilayer mirrors were shown to demonstrate a better ratio of reflection efficiency and spectral resolution compared with the commonly used Mo/Si. In the spectral range λ=17-21  nm, a new multilayer structure Al/Si was proposed, which had higher spectral resolution along with comparable reflection efficiency compared with the commonly used Al/Zr multilayer structures. In the spectral range λ=30  nm, the Si/B4C/Mg/Cr multilayer structure turned out to best obey reflection efficiency and long-term stability. The B4C and Cr layers prevented mutual diffusion of the Si and Mg layers. For the spectral range λ=58  nm, a new multilayer Mo/Mg-based structure was developed; its reflection efficiency and long-term stability have been analyzed. We also investigated intrinsic stresses inherent for most of the multilayer structures and proposed possibilities for stress elimination.

Extreme Ultraviolet Emission Lines of Iron Fe XI-XIII

Science.gov (United States)

Lepson, Jaan; Beiersdorfer, P.; Brown, G. V.; Liedahl, D. A.; Brickhouse, N. S.; Dupree, A. K.

2013-04-01

The extreme ultraviolet (EUV) spectral region (ca. 20--300 Å) is rich in emission lines from low- to mid-Z ions, particularly from the middle charge states of iron. Many of these emission lines are important diagnostics for astrophysical plasmas, providing information on properties such as elemental abundance, temperature, density, and even magnetic field strength. In recent years, strides have been made to understand the complexity of the atomic levels of the ions that emit the lines that contribute to the richness of the EUV region. Laboratory measurements have been made to verify and benchmark the lines. Here, we present laboratory measurements of Fe XI, Fe XII, and Fe XIII between 40-140 Å. The measurements were made at the Lawrence Livermore electron beam ion trap (EBIT) facility, which has been optimized for laboratory astrophysics, and which allows us to select specific charge states of iron to help line identification. We also present new calculations by the Hebrew University - Lawrence Livermore Atomic Code (HULLAC), which we also utilized for line identification. We found that HULLAC does a creditable job of reproducing the forest of lines we observed in the EBIT spectra, although line positions are in need of adjustment, and line intensities often differed from those observed. We identify or confirm a number of new lines for these charge states. This work was supported by the NASA Solar and Heliospheric Program under Contract NNH10AN31I and the DOE General Plasma Science program. Work was performed in part under the auspices of the Department of Energy by Lawrence Livermore National Laboratory under Contract DEAC52-07NA27344.

Evidence for a New Class of Extreme Ultraviolet Sources

Science.gov (United States)

Maoz, Dan; Ofek, Eran O.; Shemi, Amotz

1997-01-01

Most of the sources detected in the extreme ultraviolet (EUV; 100-600 A) by the ROSAT/WFC and EUVE all-sky surveys have been identified with active late-type stars and hot white dwarfs that are near enough to the Earth to escape absorption by interstellar gas. However, about 15 per cent of EUV sources are as yet unidentified with any optical counterparts. We examine whether the unidentified EUV sources may consist of the same population of late-type stars and white dwarfs. We present B and R photometry of stars in the fields of seven of the unidentified EUV sources. We detect in the optical the entire main-sequence and white dwarf population out to the greatest distances where they could still avoid absorption. We use color-magnitude diagrams to demonstrate that, in most of the fields, none of the observed stars has the colours and magnitudes of late-type dwarfs at distances less than 100 pc. Similarly, none of the observed stars is a white dwarf within 500 pc that is hot enough to be a EUV emitter. The unidentified EUV sources we study are not detected in X-rays, while cataclysmic variables, X-ray binaries, and active galactic nuclei generally are. We conclude that some of the EUV sources may be a new class of nearby objects, which are either very faint at optical bands or which mimic the colours and magnitudes of distant late-type stars or cool white dwarfs. One candidate for optically faint objects is isolated old neutron stars, slowly accreting interstellar matter. Such neutron stars are expected to be abundant in the Galaxy, and have not been unambiguously detected.

Efficient extreme ultraviolet plasma source generated by a CO2 laser and a liquid xenon microjet target

Science.gov (United States)

Ueno, Yoshifumi; Ariga, Tatsuya; Soumagne, George; Higashiguchi, Takeshi; Kubodera, Shoichi; Pogorelsky, Igor; Pavlishin, Igor; Stolyarov, Daniil; Babzien, Marcus; Kusche, Karl; Yakimenko, Vitaly

2007-05-01

We demonstrated efficacy of a CO2-laser-produced xenon plasma in the extreme ultraviolet (EUV) spectral region at 13.5nm at variable laser pulse widths between 200ps and 25ns. The plasma target was a 30μm liquid xenon microjet. To ensure the optimum coupling of CO2 laser energy with the plasma, they applied a prepulse yttrium aluminum garnet laser. The authors measured the conversion efficiency (CE) of the 13.5nm EUV emission for different pulse widths of the CO2 laser. A maximum CE of 0.6% was obtained for a CO2 laser pulse width of 25ns at an intensity of 5×1010W/cm2.

Efficient extreme ultraviolet plasma source generated by a CO2 laser and a liquid xenon microjet target

International Nuclear Information System (INIS)

Ueno, Yoshifumi; Ariga, Tatsuya; Soumagne, George; Higashiguchi, Takeshi; Kubodera, Shoichi; Pogorelsky, Igor; Pavlishin, Igor; Stolyarov, Daniil; Babzien, Marcus; Kusche, Karl; Yakimenko, Vitaly

2007-01-01

We demonstrated efficacy of a CO 2 -laser-produced xenon plasma in the extreme ultraviolet (EUV) spectral region at 13.5 nm at variable laser pulse widths between 200 ps and 25 ns. The plasma target was a 30 μm liquid xenon microjet. To ensure the optimum coupling of CO 2 laser energy with the plasma, they applied a prepulse yttrium aluminum garnet laser. The authors measured the conversion efficiency (CE) of the 13.5 nm EUV emission for different pulse widths of the CO 2 laser. A maximum CE of 0.6% was obtained for a CO 2 laser pulse width of 25 ns at an intensity of 5x10 10 W/cm 2

Characteristics of soft x-ray and extreme ultraviolet (XUV) emission from laser-produced highly charged rhodium ions

Science.gov (United States)

Barte, Ellie Floyd; Hara, Hiroyuki; Tamura, Toshiki; Gisuji, Takuya; Chen, When-Bo; Lokasani, Ragava; Hatano, Tadashi; Ejima, Takeo; Jiang, Weihua; Suzuki, Chihiro; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Sasaki, Akira; Higashiguchi, Takeshi; Limpouch, Jiří

2018-05-01

We have characterized the soft x-ray and extreme ultraviolet (XUV) emission of rhodium (Rh) plasmas produced using dual pulse irradiation by 150-ps or 6-ns pre-pulses, followed by a 150-ps main pulse. We have studied the emission enhancement dependence on the inter-pulse time separation and found it to be very significant for time separations less than 10 ns between the two laser pulses when using 6-ns pre-pulses. The behavior using a 150-ps pre-pulse was consistent with such plasmas displaying only weak self-absorption effects in the expanding plasma. The results demonstrate the advantage of using dual pulse irradiation to produce the brighter plasmas required for XUV applications.

Extreme Ultraviolet Emission Spectrum of CO_2 Induced by Electron Impact at 200 eV

Science.gov (United States)

Kanik, I.; Ajello, J. M.; James, G. K.

1993-01-01

We present the extreme ultraviolet (EUV) emission spectrum of CO_2 induced by electronimpact at 200 eV. There are 36 spectral features which are identified with a resolution of 0.5 nmover the wavelength range of 40 to 125 nm. Absolute emission cross sections were obtained for eachof these features. The EUV emission spectrum induced by electron impact consist of atomicmultiplets of CI,II and OI,II,III as well as CO and CO^+ molecular band systems produced bydissociative excitation. The CI (119.4 nm) multiplet is the strongest feature of CI with a peak crosssection of 3.61 x 10^(-19) cm^2 at 200 eV. The strongest feature of OI in the EUV spectrum is theOI (99.0 nm) multiplet with a peak cross section of 3.59 x 10^(-19) cm^2 at 200 eV.

Ozone decline and its effect on night airglow intensity of Na 5893°A ...

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science; Volume 115; Issue 5. Ozone decline and its effect on night airglow intensity of Na 5893°A at Dumdum (22.5°N, 88.5° E) and Halley Bay (76°S, 27°W). P K Jana S C Nandi. Volume 115 Issue 5 October 2006 pp 607-613 ...

Classification of mini-dimmings associated with extreme ultraviolet eruptions by using graph theory

Directory of Open Access Journals (Sweden)

S Bazargan

2016-09-01

Full Text Available Coronal dimmings in both micro and macro scales, can be observed by extreme ultraviolet images, recorded from Solar Dynamics Observatory or Atmospheric Imaging Assembly (SDO/AIA. Mini-dimmings are sometimes associated with wave-like brightening, called coronal mass ejections. Here, the sun full disk images with 171 Å wavelenght, cadence of 2.5, and  0.6 arcsec cell size, were taken on 3 March 2012, then the obtained data were analyzed. Using Zernike Moment and Support Vector Machine (SVM, mini dimmings are detected. 538 active region events, 680 coronal hole events and 723 quiet sun events have been recognized using algorithm. The position, time duration and spatial expansion of these events were computed .The eruptive dimmings have a more spatial development than thermal dimmings after eruptions. This is evident in their graph characteristics length. Then, using graph theory, eruptive and thermal mini-dimmings were classified, with 13% error, for 200 dimmings. 68 dimmings were classified as thermal, and 132 as eruptive. To do this, evolution of graph characteristic length were used.

George Berkeley e a tradição platônica

Directory of Open Access Journals (Sweden)

Costica Bradatan

2009-12-01

Full Text Available Existe já uma grande quantidade de literatura dedicada à presença na filosofia inicial de Berkeley de alguns assuntos tipicamente platônicos (arquétipos, o problema da mente de Deus, a relação entre ideias e coisas, etc.. Baseados em alguns desses escritos, nas próprias palavras de Berkeley, assim como no exame de alguns elementos da tradição platônica num amplo sentido, sugiro que, longe de serem apenas tópicos isolados, livremente espalhados nos primeiros escritos de Berkeley, eles formam uma perfeita rede de aspectos, atitudes e modos de pensar platônicos, e que, por mais alusivos ou ambíguos que esses elementos platônicos possam parecer, eles constituem um todo coerente e complexo, desempenhando um papel importante na formação da própria essência do pensamento de Berkeley. Em outras palavras, sugiro que, dadas algumas das ideias apresentadas em suas primeiras obras, foi de certo modo inevitável para George Berkeley, em virtude da lógica interna do desenvolvimento de seu pensamento, chegar a uma obra tão abertamente platônica e especulativa como Siris (1744.

Dynamic absorption coefficients of chemically amplified resists and nonchemically amplified resists at extreme ultraviolet

Science.gov (United States)

Fallica, Roberto; Stowers, Jason K.; Grenville, Andrew; Frommhold, Andreas; Robinson, Alex P. G.; Ekinci, Yasin

2016-07-01

The dynamic absorption coefficients of several chemically amplified resists (CAR) and non-CAR extreme ultraviolet (EUV) photoresists are measured experimentally using a specifically developed setup in transmission mode at the x-ray interference lithography beamline of the Swiss Light Source. The absorption coefficient α and the Dill parameters ABC were measured with unprecedented accuracy. In general, the α of resists match very closely with the theoretical value calculated from elemental densities and absorption coefficients, whereas exceptions are observed. In addition, through the direct measurements of the absorption coefficients and dose-to-clear values, we introduce a new figure of merit called chemical sensitivity to account for all the postabsorption chemical reaction ongoing in the resist, which also predicts a quantitative clearing volume and clearing radius, due to the photon absorption in the resist. These parameters may help provide deeper insight into the underlying mechanisms of the EUV concepts of clearing volume and clearing radius, which are then defined and quantitatively calculated.

Lawrence Berkeley National Laboratory 2015 Annual Financial Report

Energy Technology Data Exchange (ETDEWEB)

Williams, Kim, P

2017-08-11

FY2015 financial results reflect a year of significant scientific, operational and financial achievement for Lawrence Berkeley National Laboratory. Complementing many scientific accomplishments, Berkeley Lab completed construction of four new research facilities: the General Purpose Laboratory, Chu Hall, Wang Hall and the Flexlab Building Efficiency Testbed. These state-of-the-art facilities allow for program growth and enhanced collaboration, in part by enabling programs to return to the Lab’s Hill Campus from offsite locations. Detailed planning began for the new Integrative Genomics Building (IGB) that will house another major program currently located offsite. Existing site infrastructure was another key focus area. The Lab prioritized and increased investments in deferred maintenance in alignment with the Berkeley Lab Infrastructure Plan, which was developed under the leadership of the DOE Office of Science. With the expiration of American Recovery and Reinvestment Act (ARRA) funds, we completed the close-out of all of our 134 ARRA projects, recording total costs of $331M over the FY2009-2015 period. Download the report to read more.

Longitudinal Ionospheric Variability Observed by LITES on the ISS

Science.gov (United States)

Stephan, A. W.; Finn, S. C.; Cook, T.; Geddes, G.; Chakrabarti, S.; Budzien, S. A.

2017-12-01

The Limb-Imaging Ionospheric and Thermospheric Extreme-Ultraviolet Spectrograph (LITES) is an imaging spectrograph designed to measure altitude profiles (150-350 km) of extreme- and far-ultraviolet airglow emissions that originate from photochemical processes in the ionosphere and thermosphere. During the daytime, LITES observes the bright O+ 83.4 nm emission from which the ionospheric profile can be inferred. At night, recombination emissions at 91.1 and 135.6 nm provide a direct measure of the electron content along the line of sight. LITES was launched and installed on the International Space Station (ISS) in late February 2017 where it has been operating along with the highly complementary GPS Radio Occultation and Ultraviolet Photometry - Colocated (GROUP-C) experiment. We will present some of the first observations from LITES in April 2017 that show longitudinal patterns in ionospheric density and the daily variability in those patterns. LITES vertical imaging from a vantage point near 410 km enables a particularly unique perspective on the altitude of the ionospheric peak density at night that can complement and inform other ground- and space-based measurements, and track the longitude-altitude variability that is reflective of changes in equatorial electrodynamics.

Compact 13.5-nm free-electron laser for extreme ultraviolet lithography

Directory of Open Access Journals (Sweden)

Y. Socol

2011-04-01

Full Text Available Optical lithography has been actively used over the past decades to produce more and more dense integrated circuits. To keep with the pace of the miniaturization, light of shorter and shorter wavelength was used with time. The capabilities of the present 193-nm UV photolithography were expanded time after time, but it is now believed that further progress will require deployment of extreme ultraviolet (EUV lithography based on the use of 13.5-nm radiation. However, presently no light source exists with sufficient average power to enable high-volume manufacturing. We report here the results of a study that shows the feasibility of a free-electron laser EUV source driven by a multiturn superconducting energy-recovery linac (ERL. The proposed 40×20  m^{2} facility, using MW-scale consumption from the power grid, is estimated to provide about 5 kW of average EUV power. We elaborate the self-amplified spontaneous emission (SASE option, which is presently technically feasible. A regenerative-amplifier option is also discussed. The proposed design is based on a short-period (2–3 cm undulator. The corresponding electron beam energy is about 0.5–1.0 GeV. The proposed accelerator consists of a photoinjector, a booster, and a multiturn ERL.

Political-social reactor problems at Berkeley

International Nuclear Information System (INIS)

Little, G.A.

1980-01-01

For better than ten years there was little public notice of the TRIGA reactor at UC-Berkeley. Then: a) A non-student persuaded the Student and Senate to pass a resolution to request Campus Administration to stop operation of the reactor and remove it from campus. b) Presence of the reactor became a campaign-issue in a City Mayoral election. c) Two local residents reported adverse physical reactions before, during, and after a routine tour of the reactor facility. d) The Berkeley City Council began a study of problems associated with radioactive material within the city. e) Friends Of The Earth formally petitioned the NRC to terminate the reactor's license. Campus personnel have expended many man-hours and many pounds of paper in responding to these happenings. Some of the details are of interest, and may be of use to other reactor facilities. (author)

Spectral filter for splitting a beam with electromagnetic radiation having wavelengths in the extreme ultraviolet (EUV) or soft X-Ray (Soft X) and the infrared (IR) wavelength range

NARCIS (Netherlands)

van Goor, F.A.; Bijkerk, Frederik; van den Boogaard, Toine; van den Boogaard, A.J.R.; van der Meer, R.

2012-01-01

Spectral filter for splitting the primary radiation from a generated beam with primary electromagnetic radiation having a wavelength in the extreme ultraviolet (EUV radiation) or soft X-ray (soft X) wavelength range and parasitic radiation having a wavelength in the infrared wavelength range (IR

Optical studies of noctilucent clouds in the extreme ultraviolet

Directory of Open Access Journals (Sweden)

J. Hedin

2008-05-01

Full Text Available In order to better understand noctilucent clouds (NLC and their sensitivity to the variable environment of the polar mesosphere, more needs to be learned about the actual cloud particle population. Optical measurements are today the only means of obtaining information about the size of mesospheric ice particles. In order to efficiently access particle sizes, scattering experiments need to be performed in the Mie scattering regime, thus requiring wavelengths of the order of the particle size. Previous studies of NLC have been performed at wavelengths down to 355 nm from the ground and down to about 200 nm from rockets and satellites. However, from these measurements it is not possible to access the smaller particles in the mesospheric ice population. This current lack of knowledge is a major limitation when studying important questions about the nucleation and growth processes governing NLC and related particle phenomena in the mesosphere. We show that NLC measurements in the extreme ultraviolet, in particular using solar Lyman-α radiation at 121.57 nm, are an efficient way to further promote our understanding of NLC particle size distributions. This applies both to global measurements from satellites and to detailed in situ studies from sounding rockets. Here, we present examples from recent rocket-borne studies that demonstrate how ambiguities in the size retrieval at longer wavelengths can be removed by invoking Lyman-α. We discuss basic requirements and instrument concepts for future rocket-borne NLC missions. In order for Lyman-α radiation to reach NLC altitudes, high solar elevation and, hence, daytime conditions are needed. Considering the effects of Lyman-α on NLC in general, we argue that the traditional focus of rocket-borne NLC missions on twilight conditions has limited our ability to study the full complexity of the summer mesopause environment.

The Advanced Light Source: A new 1.5 GeV synchrotron radiation facility at the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Schlachter, A.S.

1989-01-01

The Advanced Light Source (ALS), now under construction at the Lawrence Berkeley Laboratory, is being planned as a national user facility for the production of high-brightness and partially coherent 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 11 long straight sections and up to 48 bend-magnet ports. High-brightness photon beams, from less than 10 eV to more than 1 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., 10 figs., 2 tabs

THE EXTREME ULTRAVIOLET DEFICIT AND MAGNETICALLY ARRESTED ACCRETION IN RADIO-LOUD QUASARS

Energy Technology Data Exchange (ETDEWEB)

Punsly, Brian, E-mail: brian.punsly1@verizon.net [1415 Granvia Altamira, Palos Verdes Estates, CA 90274 (United States); ICRANet, Piazza della Repubblica, I-65100 10 Pescara (Italy)

2014-12-20

The Hubble Space Telescope composite quasar spectra presented in Telfer et al. show a significant deficit of emission in the extreme ultraviolet for the radio-loud component of the quasar population (RLQs) compared to the radio-quiet component of the quasar population. The composite quasar continuum emission between 1100 Å and ∼580 Å is generally considered to be associated with the innermost regions of the accretion flow onto the central black hole. The deficit between 1100 Å and 580 Å in RLQs has a straightforward interpretation as a missing or a suppressed innermost region of local energy dissipation in the accretion flow. It is proposed that this can be the result of islands of large-scale magnetic flux in RLQs that are located close to the central black hole that remove energy from the accretion flow as Poynting flux (sometimes called magnetically arrested accretion). These magnetic islands are natural sites for launching relativistic jets. Based on the Telfer et al. data and the numerical simulations of accretion flows in Penna et al., the magnetic islands are concentrated between the event horizon and an outer boundary of <2.8 M (in geometrized units) for rapidly rotating black holes and <5.5 M for modestly rotating black holes.

The extreme ultraviolet spectrum of G191 - B2B and the ionization of the local interstellar medium

Science.gov (United States)

Green, James; Jelinsky, Patrick; Bowyer, Stuart

1990-01-01

The measurement of the extreme ultraviolet spectrum of the nearby hot white dwarf G191 - B2B is reported. The results are used to derive interstellar neutral column densities of 1.6 + or - 0.2 x 10 to the 18th/sq cm and 9.8 + 2.8 or - 2.6 x 10 to the 16th/sq cm for H I and He I, respectively. This ratio of neutral hydrogen to neutral helium indicates that the ionization of hydrogen along the line of sight is less than about 30 percent unless significant helium ionization is present. The scenario in which the hydrogen is highly ionized and the helium is neutral is ruled out by this observation.

Power Management Controls, Ernest Orlando Lawrence Berkeley National Laboratory; Power Management Controls, Ernest Orlando Lawrence Berkeley National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Westerberg, Emil [Dalarna Univ., Borlaenge (Sweden). Graphic Art Technology

2002-12-01

This report describes the work that is being conducted on power management controls at Berkeley National Laboratory. We can see a significant increasing amount of electronic equipment in our work places and in our every day life. Today's modern society depends on a constant energy flow. The future's increasing need of energy will burden our economy as well as our environment. The project group at Berkeley National Laboratory is working with leading manufacturers of office equipment. The goal is to agree on how interfaces for power management should be presented on office equipment. User friendliness and a more consistent power management interface is the project focus. The project group's role is to analyze data that is relevant to power management, as well as to coordinate communication and discussions among the involved parties.

Guidelines for the segregation characterization management of dry waste at Berkeley Lab

International Nuclear Information System (INIS)

1997-05-01

Managing and disposing of dry low level radioactive waste at Berkeley Lab. is problematic. The Waste Management Group must assure off site treatment, storage, and disposal facilities that dry waste from Berkeley Lab. is free of liquids and regulated metals (such as lead and mercury). RTR (Real Time Radioagraphy) used for waste to be rejected. This pamphlet helps to clarify dry waste management requirements that will ensure that Berkeley Lab. dry waste will be accepted for off site shipment. These issues are critical if we are to have an off site disposal option for your dry radioactive waste

Extreme sensitivity to ultraviolet light in the fungal pathogen causing white-nose syndrome of bats.

Science.gov (United States)

Palmer, Jonathan M; Drees, Kevin P; Foster, Jeffrey T; Lindner, Daniel L

2018-01-02

Bat white-nose syndrome (WNS), caused by the fungal pathogen Pseudogymnoascus destructans, has decimated North American hibernating bats since its emergence in 2006. Here, we utilize comparative genomics to examine the evolutionary history of this pathogen in comparison to six closely related nonpathogenic species. P. destructans displays a large reduction in carbohydrate-utilizing enzymes (CAZymes) and in the predicted secretome (~50%), and an increase in lineage-specific genes. The pathogen has lost a key enzyme, UVE1, in the alternate excision repair (AER) pathway, which is known to contribute to repair of DNA lesions induced by ultraviolet (UV) light. Consistent with a nonfunctional AER pathway, P. destructans is extremely sensitive to UV light, as well as the DNA alkylating agent methyl methanesulfonate (MMS). The differential susceptibility of P. destructans to UV light in comparison to other hibernacula-inhabiting fungi represents a potential "Achilles' heel" of P. destructans that might be exploited for treatment of bats with WNS.

Langmuir probe measurement of the bismuth plasma plume formed by an extreme-ultraviolet pulsed laser

International Nuclear Information System (INIS)

Pira, P; Burian, T; Kolpaková, A; Tichý, M; Kudrna, P; Daniš, S; Wild, J; Juha, L; Lančok, J; Vyšín, L; Civiš, S; Zelinger, Z; Kubát, P

2014-01-01

Properties of the plasma plume produced on a bismuth (Bi) target irradiated by a focused extreme-ultraviolet (XUV) capillary-discharge laser beam were investigated. Langmuir probes were used in both single- and double-probe arrangements to determine the electron temperature and the electron density, providing values of 1–3 eV and ∼10 13 –10 14  m −3 , respectively. Although the temperatures seem to be comparable with values obtained in ablation plasmas produced by conventional, long-wavelength lasers, the density is significantly lower. This finding indicates that the desorption-like phenomena are responsible for the plume formation rather than the ablation processes. A very thin Bi film was prepared on an MgO substrate by pulsed XUV laser deposition. The non-uniform, sub-monolayer character of the deposited bismuth film confirms the Langmuir probe's observation of the desorption-like erosion induced by the XUV laser on the primary Bi target. (paper)

UC Berkeley's Celebration of the International Year of Astronomy 2009

Science.gov (United States)

Cobb, B. E.; Croft, S.; Silverman, J. M.; Klein, C.; Modjaz, M.

2010-08-01

We present the astronomy outreach efforts undertaken for the International Year of Astronomy 2009 at the University of California, Berkeley. Our department-wide endeavors included a monthly public lecture series by UC Berkeley astronomers and a major astronomy outreach event during a campus-wide university "open house," which included solar observing and a Starlab Planetarium. In addition to sharing our outreach techniques and outcomes, we discuss some of our unique strategies for advertising our events to the local community.

Ernest Orlando Lawrence Berkeley National Laboratory Institutional Plan FY 2000-2004

Energy Technology Data Exchange (ETDEWEB)

Chartock, Mike (ed.); Hansen, Todd (ed.)

1999-08-01

The FY 2000-2004 Institutional Plan provides an overview of the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab, the Laboratory) mission, strategic plan, initiatives, and the resources required to fulfill its role in support of national needs in fundamental science and technology, energy resources, and environmental quality. To advance the Department of Energy's ongoing efforts to define the Integrated Laboratory System, the Berkeley Lab Institutional Plan reflects the strategic elements of our planning efforts. The Institutional Plan is a management report that supports the Department of Energy's mission and programs and is an element of the Department of Energy's strategic management planning activities, developed through an annual planning process. The Plan supports the Government Performance and Results Act of 1993 and complements the performance-based contract between the Department of Energy and the Regents of the University of California. It identifies technical and administrative directions in the context of the national energy policy and research needs and the Department of Energy's program planning initiatives. Preparation of the plan is coordinated by the Office of Planning and Communications from information contributed by Berkeley Lab's scientific and support divisions.

Plasma-assisted cleaning of extreme UV optics

NARCIS (Netherlands)

Dolgov, Alexandr Alexeevich

2018-01-01

Plasma-assisted cleaning of extreme UV optics EUV-induced surface plasma chemistry of photo-active agents The next generation of photolithography, extreme ultraviolet (EUV) lithography, makes use of 13.5 nm radiation. The ionizing photon flux, and vacuum requirements create a challenging operating

Response of the upper atmosphere to variations in the solar soft x-ray irradiance. Ph.D. Thesis

Science.gov (United States)

Bailey, Scott Martin

1995-01-01

Terrestrial far ultraviolet (FUV) airglow emissions have been suggested as a means for remote sensing the structure of the upper atmosphere. The energy which leads to the excitation of FUV airglow emissions is solar irradiance at extreme ultraviolet (EUV) and soft x-ray wavelengths. Solar irradiance at these wavelengths is known to be highly variable; studies of nitric oxide (NO) in the lower thermosphere have suggested a variability of more than an order of magnitude in the solar soft x-ray irradiance. To properly interpret the FUV airflow, the magnitude of the solar energy deposition must be known. Previous analyses have used the electron impact excited Lyman-Birge-Hopfield (LBH) bands of N2 to infer the flux of photoelectrons in the atmosphere and thus to infer the magnitude of the solar irradiance. This dissertation presents the first simultaneous measurements of the FUV airglow, the major atmospheric constituent densities, and the solar EUV and soft x-ray irradiances. The measurements were made on three flights of an identical sounding rocket payload at different levels of solar activity. The linear response in brightness of the LBH bands to variations in solar irradiance is demonstrated. In addition to the N2 LBH bands, atomic oxygen lines at 135.6 and 130.4 nm are also studied. Unlike the LBH bands, these emissions undergo radiative transfer effects in the atmosphere. The OI emission at 135.6 nm is found to be well modeled using a radiative transfer calculation and the known excitation processes. Unfortunately, the assumed processes leading to OI 130.4 nm excitation are found to be insufficient to reproduce the observed variability of this emission. Production of NO in the atmosphere is examined; it is shown that a lower than previously reported variability in the solar soft x-ray irradiance is required to explain the variability of NO.

Capability of simultaneous Rayleigh LiDAR and O2 airglow measurements in exploring the short period wave characteristics

Science.gov (United States)

Taori, Alok; Raghunath, Karnam; Jayaraman, Achuthan

We use combination of simultaneous measurements made with Rayleigh lidar and O2 airglow monitoring to improve lidar investigation capability to cover a higher altitude range. We feed instantaneous O2 airglow temperatures instead the model values at the top altitude for subsequent integration method of temperature retrieval using Rayleigh lidar back scattered signals. Using this method, errors in the lidar temperature estimates converges at higher altitudes indicating better altitude coverage compared to regular methods where model temperatures are used instead of real-time measurements. This improvement enables the measurements of short period waves at upper mesospheric altitudes (~90 km). With two case studies, we show that above 60 km the few short period wave amplitude drastically increases while, some of the short period wave show either damping or saturation. We claim that by using such combined measurements, a significant and cost effective progress can be made in the understanding of short period wave processes which are important for the coupling across the different atmospheric regions.

The extreme ultraviolet spectrum of G191 - B2B and the ionization of the local interstellar medium

International Nuclear Information System (INIS)

Green, J.; Jelinsky, P.; Bowyer, S.

1990-01-01

The measurement of the extreme ultraviolet spectrum of the nearby hot white dwarf G191 - B2B is reported. The results are used to derive interstellar neutral column densities of 1.6 + or - 0.2 x 10 to the 18th/sq cm and 9.8 + 2.8 or - 2.6 x 10 to the 16th/sq cm for H I and He I, respectively. This ratio of neutral hydrogen to neutral helium indicates that the ionization of hydrogen along the line of sight is less than about 30 percent unless significant helium ionization is present. The scenario in which the hydrogen is highly ionized and the helium is neutral is ruled out by this observation. 54 refs

Nuclear Medicine at Berkeley Lab: From Pioneering Beginnings to Today (LBNL Summer Lecture Series)

International Nuclear Information System (INIS)

Budinger, Thomas

2006-01-01

Summer Lecture Series 2006: Thomas Budinger, head of Berkeley Lab's Center for Functional Imaging, discusses Berkeley Lab's rich history pioneering the field of nuclear medicine, from radioisotopes to medical imaging.

The Sandia laser plasma extreme ultraviolet and soft x-ray (XUV) light source

International Nuclear Information System (INIS)

Tooman, T.P.

1986-01-01

Laser produced plasmas have been shown to be extremely bright sources of extreme ultraviolet and soft x-ray (XUV) radiation; however, certain practical difficulties have hindered the development of this source as a routinely usable laboratory device. To explore solutions to these difficulties, Sandia has constructed an XUV laser plasma source (LASPS) with the intention of developing an instrument that can be used for experiments requiring intense XUV radiation from 50-300 eV. The driving laser for this source is a KrF excimer with a wavelength of 248 nm, divergence of 200 μrad, pulse width of 23 ns at 20 Hz and typical pulse energy of 500 mJ which allows for good energy coupling to the plasma at moderate (10/sup 12/ W cm/sup 2/) power densities. This source has been pulsed approximately 2 x 10/sup 5/ times, demonstrating good tolerance to plasma debris. The source radiates from the visible to well above 1000 eV, however, to date attention has been concentrated on the 50-300 eV region. In this paper, spectral data and plasma images for both stainless steel and gold targets are presented with the gold target yielding a 200 μm plasma and reradiating 3.9% of the pump energy into 15-73 eV band, a flux of 1.22 x 10/sup 13/ photons/pulse/eV into 2π sr. Further efforts will expand these measurements to rare earth targets and to higher spectral energies. A special high throughput wide angle XUV (50-300 eV) monochromator and associated optics is being concurrently developed to collect the plasma radiation, perform energy dispersion and focus the radiation onto the experimental area

Electron Microscope Center Opens at Berkeley.

Science.gov (United States)

Robinson, Arthur L.

1981-01-01

A 1.5-MeV High Voltage Electron Microscope has been installed at the Lawrence Berkeley Laboratory which will help materials scientists and biologists study samples in more true-to-life situations. A 1-MeV Atomic Resolution Microscope will be installed at the same location in two years which will allow scientists to distinguish atoms. (DS)

Plasma radiation dynamics with the upgraded Absolute Extreme Ultraviolet tomographical system in the Tokamak à Configuration Variable

Energy Technology Data Exchange (ETDEWEB)

Tal, B.; Nagy, D.; Veres, G. [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Association EURATOM, P. O. Box 49, H-1525 Budapest (Hungary); Labit, B.; Chavan, R.; Duval, B. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association EURATOM-Confédération Suisse, EPFL SB CRPP, Station 13, CH-1015 Lausanne (Switzerland)

2013-12-15

We introduce an upgraded version of a tomographical system which is built up from Absolute Extreme Ultraviolet-type (AXUV) detectors and has been installed on the Tokamak à Configuration Variable (TCV). The system is suitable for the investigation of fast radiative processes usually observed in magnetically confined high-temperature plasmas. The upgrade consists in the detector protection by movable shutters, some modifications to correct original design errors and the improvement in the data evaluation techniques. The short-term sensitivity degradation of the detectors, which is caused by the plasma radiation itself, has been monitored and found to be severe. The results provided by the system are consistent with the measurements obtained with the usual plasma radiation diagnostics installed on TCV. Additionally, the coupling between core plasma radiation and plasma-wall interaction is revealed. This was impossible with other available diagnostics on TCV.

Superbends expand the scope of Berkeley's ALS

CERN Document Server

Robin, D S; Tamura, L S

2002-01-01

The first-ever retrofit of superconducting bend magnets into the storage ring of an operating synchrotron radiation source extends the spectrum of Lawrence Berkeley National Laboratory's Advanced Light Source into the hard-X-ray region without compromising soft X-ray availability, or performance. (4 refs).

Analysis of extreme ultraviolet spectra from laser produced rhenium plasmas

Science.gov (United States)

Wu, Tao; Higashiguchi, Takeshi; Li, Bowen; Suzuki, Yuhei; Arai, Goki; Dinh, Thanh-Hung; Dunne, Padraig; O'Reilly, Fergal; Sokell, Emma; Liu, Luning; O'Sullivan, Gerry

2015-08-01

Extreme ultraviolet spectra of highly-charged rhenium ions were observed in the 1-7 nm region using two Nd:YAG lasers with pulse lengths of 150 ps and 10 ns, respectively, operating at a number of laser power densities. The maximum focused peak power density was 2.6 × 1014 W cm-2 for the former and 5.5 × 1012 W cm-2 for the latter. The Cowan suite of atomic structure codes and unresolved transition array (UTA) approach were used to calculate and interpret the emission properties of the different spectra obtained. The results show that n = 4-n = 4 and n = 4-n = 5 UTAs lead to two intense quasi-continuous emission bands in the 4.3-6.3 nm and 1.5-4.3 nm spectral regions. As a result of the different ion stage distributions in the plasmas induced by ps and ns laser irradiation the 1.5-4.3 nm UTA peak moves to shorter wavelength in the ps laser produced plasma spectra. For the ns spectrum, the most populated ion stage during the lifetime of this plasma that could be identified from the n = 4-n = 5 transitions was Re23+ while for the ps plasma the presence of significantly higher stages was demonstrated. For the n = 4-n = 4 4p64dN-4p54dN+1 + 4p64dN-14f transitions, the 4d-4f transitions contribute mainly in the most intense 4.7-5.5 nm region while the 4p-4d subgroup gives rise to a weaker feature in the 4.3-4.7 nm region. A number of previously unidentified spectral features produced by n = 4-n = 5 transitions in the spectra of Re XVI to Re XXXIX are identified.

Seasonal and local time variability of ripples from airglow imager observations in US and Japan

Directory of Open Access Journals (Sweden)

J. Yue

2010-07-01

Full Text Available Ripples as seen in airglow imagers are small wavy structures with short horizontal wavelengths (<15 km. Ripples are thought to form as the result of local instabilities, which are believed to occur when the amplitude of gravity waves becomes large enough. We have investigated ripple formation based on years of airglow imager observations located at Fort Collins, Colorado (41° N, 105° W and Misato Observatory, Japan (34° N, 135° E/Shigaraki MU Observatory (35° N, 136° E. Na temperature-wind lidar observations are employed to detect convective and dynamic instabilities in the mesosphere and lower thermosphere (MLT region over Fort Collins, Colorado. Seasonal variation of the ripple occurrence in Colorado is compared to that of the lidar-measured instability. The occurrence frequency of ripples varies semiannually, with maxima occurring during solstices and minima during equinoxes in both Colorado and Japan. However, the probability of convective and dynamic instabilities varies annually with a peak in Colorado winter. The seasonal variation of the occurrence frequency of ripples correlates with that of the gravity wave variances in the MLT. Ripple occurrence over Colorado also shows strong local time dependence, but it bears little resemblance to the local time dependence of instability probability.

The quiet Sun extreme ultraviolet spectrum observed in normal incidence by the SOHO Coronal Diagnostic Spectrometer

CERN Document Server

Brooks, D H; Fludra, A; Harrison, R A; Innes, D E; Landi, E; Landini, M; Lang, J; Lanzafame, A C; Loch, S D; McWhirter, R W P; Summers, H P; Thompson, W T

1999-01-01

The extreme ultraviolet quiet Sun spectrum, observed at normal incidence by the Coronal Diagnostic Spectrometer on the SOHO spacecraft, is presented. The spectrum covers the wavelength ranges 308-381 AA and 513-633 AA and is based $9 on data recorded at various positions on the solar disk between October 1996 and February 1997. Datasets at twelve of these `positions' were judged to be free from active regions and data faults and selected for detailed study. A $9 constrained maximum likelihood spectral line fitting code was used to analyse the spectral features. In all over 200 spectrum lines have been measured and about 50 186584dentified. The line identification process consisted of a $9 number of steps. Firstly assignment of well known lines was made and used to obtain the primary wavelength calibration. Variations of wavelengths with position were used to assess the precision of calibration achievable. Then, an $9 analysis method first used in studies with the CHASE experiment, was applied to the new obser...

Disintegration of the Aged Open Cluster Berkeley 17

Energy Technology Data Exchange (ETDEWEB)

Bhattacharya, Souradeep; Vaidya, Kaushar [Department of Physics, Birla Institute of Technology and Science, Pilani 333031, Rajasthan (India); Mishra, Ishan [Indian Institute of Technology Guwahati, Guwahati 781039, Assam (India); Chen, W. P., E-mail: f2012553@pilani.bits-pilani.ac.in [Graduate Institute of Astronomy, National Central University, 300 Jhongda Road, Jhongli 32001, Taiwan (China)

2017-10-01

We present the analysis of the morphological shape of Berkeley 17, the oldest known open cluster (∼10 Gyr), using the probabilistic star counting of Pan-STARRS point sources, and confirm its core-tail shape, plus an antitail, previously detected with the 2MASS data. The stellar population, as diagnosed by the color–magnitude diagram and theoretical isochrones, shows many massive members in the clusters core, whereas there is a paucity of such members in both of the tails. This manifests mass segregation in this aged star cluster with the low-mass members being stripped away from the system. It has been claimed that Berkeley 17 is associated with an excessive number of blue straggler candidates. A comparison of nearby reference fields indicates that about half of these may be field contamination.

The Formation of a Power Multi-Pulse Extreme Ultraviolet Radiation in the Pulse Plasma Diode of Low Pressure

Directory of Open Access Journals (Sweden)

Ievgeniia V. Borgun

2013-01-01

Full Text Available In this paper results are presented on experimental studies of the temporal characteristics of spike extreme ultraviolet (EUV radiation in the spectral range of 12.2 ÷ 15.8 nm from the anode region of high-current (I = 40 kA pulsed discharges in tin vapor. It is observed that the intense multi-spike radiation in this range arises at an inductive stage of the discharge. It has been shown that the radiation spikes correlate with the sharp increase of active resistance and of pumped power, due to plasma heating by an electron beam, formed in the double layer of charged particles. It has been observed that for large number of spikes the conversion efficiency of pumped energy into radiationat double layer formation is essentially higher in comparison with collisional heating.

Berkeley Lab's ALS generates femtosecond synchrotron radiation

CERN Document Server

Robinson, A L

2000-01-01

A team at Berkeley's Advanced Light Source has shown how a laser time-slicing technique provides a path to experiments with ultrafast time resolution. A Lawrence Berkeley National Laboratory team has succeeded in generating 300 fs pulses of synchrotron radiation at the ALS synchrotron radiation machine. The team's members come from the Materials Sciences Division (MSD), the Center for Beam Physics in the Accelerator and Fusion Research Division and the Advanced Light Source (ALS). Although this proof-of principle experiment made use of visible light on a borrowed beamline, the laser "time-slicing" technique at the heart of the demonstration will soon be applied in a new bend magnet beamline that was designed specially for the production of femtosecond pulses of X-rays to study long-range and local order in condensed matter with ultrafast time resolution. An undulator beamline based on the same technique has been proposed that will dramatically increase the flux and brightness. The use of X-rays to study the c...

Maximum material thickness for extreme ultra-violet and X-ray backlighter probing of dense plasma

International Nuclear Information System (INIS)

Huang, H.; Tallents, G.J.

2008-01-01

Extreme ultra-violet (EUV) lasers, X-ray lasers and other backlighter sources can be used to probe high-energy density materials if their brightness can overcome self-emission from the material. We investigate the maximum plasma thickness of aluminum, silicon and iron that can be probed with EUV or X-ray photons of energy 89-1243 eV before self-emission from the plasma overwhelms the backlighter output. For a uniform plasma, backlighter transmission decreases exponentially with increasing thickness of the material following Beer's law at a rate dependent on the plasma opacity. We evaluate the plasma opacity with the Los Alamos TOPS opacity data. The self-emission is assumed to be either that of a black body to arise from a plasma in LTE or to only consist of free-free and free-bound emission. It is shown that at higher plasma temperature (≥40 eV), EUV radiation (e.g. photon energy=89 eV) can probe a greater thickness of plasma than X-ray radiation (e.g. photon energy=1243 eV)

Fiscal 2000 survey and research achievement report on the survey and research on next-generation EUVL (extreme ultraviolet lithography) technology; 2000 nendo jisedai EUVL (Extreme Ultra-Violet Lithography) gijutsu chosa kenkyu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

While surveys of technical progress and tasks of EUVL in Japan and overseas are under way for submitting a proposition for the industrialization of EUVL technology by expatiating the results of the EUVL research and development program scheduled to be complete in fiscal 2001, the future of EUVL is considered. The survey results are summarized in five chapters which involve (1) the outlines of survey and research results, (2) technical trends of lithography, (3) systems for EUVL research and development in the world, and (5) the conclusion. In chapter (4), light sources, systems (exposure devices), masks, resists, and other element technologies are investigated. The survey results about light sources involve the background against which their development is described, performance that an extreme ultraviolet ray source is requested to have, candidate EUVL light sources, their technical features and tasks they present, and the latest trends overseas. Concerning the exposure device, the body (device constitution), stage, sensor, projection system, and the irradiation system are investigated. As for masks, the outline of a EUVL mask, masking substrate, multilayer film fabrication, masking pattern formation, and other tasks for development are investigated. (NEDO)

Multiple Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California

Science.gov (United States)

Pike, Richard J.; Graymer, Russell W.

2008-01-01

With the exception of Los Angeles, perhaps no urban area in the United States is more at risk from landsliding, triggered by either precipitation or earthquake, than the San Francisco Bay region of northern California. By January each year, seasonal winter storms usually bring moisture levels of San Francisco Bay region hillsides to the point of saturation, after which additional heavy rainfall may induce landslides of various types and levels of severity. In addition, movement at any time along one of several active faults in the area may generate an earthquake large enough to trigger landslides. The danger to life and property rises each year as local populations continue to expand and more hillsides are graded for development of residential housing and its supporting infrastructure. The chapters in the text consist of: *Introduction by Russell W. Graymer *Chapter 1 Rainfall Thresholds for Landslide Activity, San Francisco Bay Region, Northern California by Raymond C. Wilson *Chapter 2 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike and Steven Sobieszczyk *Chapter 3 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Chapter 4 Landslide Hazard Modeled for the Cities of Oakland, Piedmont, and Berkeley, Northern California, from a M=7.1 Scenario Earthquake on the Hayward Fault Zone by Scott B. Miles and David K. Keefer *Chapter 5 Synthesis of Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike The plates consist of: *Plate 1 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike, Russell W. Graymer, Sebastian Roberts, Naomi B. Kalman, and Steven Sobieszczyk *Plate 2 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven

TEMPERATURE AND EXTREME-ULTRAVIOLET INTENSITY IN A CORONAL PROMINENCE CAVITY AND STREAMER

Energy Technology Data Exchange (ETDEWEB)

Kucera, T. A. [NASA/GSFC, Code 671, Greenbelt, MD 20771 (United States); Gibson, S. E.; Schmit, D. J. [HAO/NCAR, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Landi, E. [Department of Atmospheric, Oceanic and Space Science, Space Research Building, University of Michigan, 2455 Hayward St., Ann Arbor, MI 48109-2143 (United States); Tripathi, D. [Inter-University Centre for Astronomy and Astrophysics, Post Bag-4, Ganeshkhind, Pune University Campus, Pune 411 007 (India)

2012-09-20

We analyze the temperature and EUV line emission of a coronal cavity and surrounding streamer in terms of a morphological forward model. We use a series of iron line ratios observed with the Hinode Extreme-ultraviolet Imaging Spectrograph (EIS) on 2007 August 9 to constrain temperature as a function of altitude in a morphological forward model of the streamer and cavity. We also compare model predictions to the EIS EUV line intensities and polarized brightness (pB) data from the Mauna Loa Solar Observatory (MLSO) Mark 4 K-coronameter. This work builds on earlier analysis using the same model to determine geometry of and density in the same cavity and streamer. The fit to the data with altitude-dependent temperature profiles indicates that both the streamer and cavity have temperatures in the range 1.4-1.7 MK. However, the cavity exhibits substantial substructure such that the altitude-dependent temperature profile is not sufficient to completely model conditions in the cavity. Coronal prominence cavities are structured by magnetism so clues to this structure are to be found in their plasma properties. These temperature substructures are likely related to structures in the cavity magnetic field. Furthermore, we find that the model overestimates the EUV line intensities by a factor of 4-10, without overestimating pB. We discuss this difference in terms of filling factors and uncertainties in density diagnostics and elemental abundances.

Femtosecond tracking of carrier relaxation in germanium with extreme ultraviolet transient reflectivity

Science.gov (United States)

Kaplan, Christopher J.; Kraus, Peter M.; Ross, Andrew D.; Zürch, Michael; Cushing, Scott K.; Jager, Marieke F.; Chang, Hung-Tzu; Gullikson, Eric M.; Neumark, Daniel M.; Leone, Stephen R.

2018-05-01

Extreme ultraviolet (XUV) transient reflectivity around the germanium M4 ,5 edge (3 d core-level to valence transition) at 30 eV is advanced to obtain the transient dielectric function of crystalline germanium [100] on femtosecond to picosecond time scales following photoexcitation by broadband visible-to-infrared (VIS/NIR) pulses. By fitting the transient dielectric function, carrier-phonon induced relaxations are extracted for the excited carrier distribution. The measurements reveal a hot electron relaxation rate of 3.2 ±0.2 ps attributed to the X -L intervalley scattering and a hot hole relaxation rate of 600 ±300 fs ascribed to intravalley scattering within the heavy hole (HH) band, both in good agreement with previous work. An overall energy shift of the XUV dielectric function is assigned to a thermally induced band gap shrinkage by formation of acoustic phonons, which is observed to be on a timescale of 4-5 ps, in agreement with previously measured optical phonon lifetimes. The results reveal that the transient reflectivity signal at an angle of 66∘ with respect to the surface normal is dominated by changes to the real part of the dielectric function, due to the near critical angle of incidence of the experiment (66∘-70∘) for the range of XUV energies used. This work provides a methodology for interpreting XUV transient reflectivity near core-level transitions, and it demonstrates the power of the XUV spectral region for measuring ultrafast excitation dynamics in solids.

New Cepheid variables in the young open clusters Berkeley 51 and Berkeley 55

Science.gov (United States)

Lohr, M. E.; Negueruela, I.; Tabernero, H. M.; Clark, J. S.; Lewis, F.; Roche, P.

2018-05-01

As part of a wider investigation of evolved massive stars in Galactic open clusters, we have spectroscopically identified three candidate classical Cepheids in the little-studied clusters Berkeley 51, Berkeley 55 and NGC 6603. Using new multi-epoch photometry, we confirm that Be 51 #162 and Be 55 #107 are bona fide Cepheids, with pulsation periods of 9.83±0.01 d and 5.850±0.005 d respectively, while NGC 6603 star W2249 does not show significant photometric variability. Using the period-luminosity relationship for Cepheid variables, we determine a distance to Be 51 of 5.3^{+1.0}_{-0.8} kpc and an age of 44^{+9}_{-8} Myr, placing it in a sparsely-attested region of the Perseus arm. For Be 55, we find a distance of 2.2±0.3 kpc and age of 63^{+12}_{-11} Myr, locating the cluster in the Local arm. Taken together with our recent discovery of a long-period Cepheid in the starburst cluster VdBH222, these represent an important increase in the number of young, massive Cepheids known in Galactic open clusters. We also consider new Gaia (data release 2) parallaxes and proper motions for members of Be 51 and Be 55; the uncertainties on the parallaxes do not allow us to refine our distance estimates to these clusters, but the well-constrained proper motion measurements furnish further confirmation of cluster membership. However, future final Gaia parallaxes for such objects should provide valuable independent distance measurements, improving the calibration of the period-luminosity relationship, with implications for the distance ladder out to cosmological scales.

Berkeley Experiments on Superfluid Macroscopic Quantum Effects

International Nuclear Information System (INIS)

Packard, Richard

2006-01-01

This paper provides a brief history of the evolution of the Berkeley experiments on macroscopic quantum effects in superfluid helium. The narrative follows the evolution of the experiments proceeding from the detection of single vortex lines to vortex photography to quantized circulation in 3He to Josephson effects and superfluid gyroscopes in both 4He and 3He

Berkeley Lab Sheds Light on Improving Solar Cell Efficiency

International Nuclear Information System (INIS)

Lawrence Berkeley National Laboratory

2007-01-01

Typical manufacturing methods produce solar cells with an efficiency of 12-15%; and 14% efficiency is the bare minimum for achieving a profit. In work performed at the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley, CA, 5 10-486-577 1)--a US Department of Energy national laboratory that conducts unclassified scientific research and is managed by the University of California--scientist Scott McHugo has obtained keen insights into the impaired performance of solar cells manufactured from polycrystalline silicon. The solar cell market is potentially vast, according to Berkeley Lab. Lightweight solar panels are highly beneficial for providing electrical power to remote locations in developing nations, since there is no need to build transmission lines or truck-in generator fuel. Moreover, industrial nations confronted with diminishing resources have active programs aimed at producing improved, less expensive solar cells. 'In a solar cell, there is a junction between p-type silicon and an n-type layer, such as diffused-in phosphorous', explained McHugo, who is now with Berkeley Lab's Accelerator and Fusion Research Division. 'When sunlight is absorbed, it frees electrons, which start migrating in a random-walk fashion toward that junction. If the electrons make it to the junction; they contribute to the cell's output of electric current. Often, however, before they reach the junction, they recombine at specific sites in the crystal' (and, therefore, cannot contribute to current output). McHugo scrutinized a map of a silicon wafer in which sites of high recombination appeared as dark regions. Previously, researchers had shown that such phenomena occurred not primarily at grain boundaries in the polycrystalline material, as might be expected, but more often at dislocations in the crystal. However, the dislocations themselves were not the problem. Using a unique heat treatment technique, McHugo performed electrical measurements to investigate the material

Design, conception, and metrology of Extreme Ultraviolet multilayers mirrors resistant environments of space and EUV sources

International Nuclear Information System (INIS)

Hecquet, Ch.

2009-03-01

The Extreme Ultraviolet Spectrum (EUV) wavelengths, which range between 13 nm and 40 nm, have many applications in science and technology. These have been developed for example in plasma physics (high order harmonics sources, X ray lasers). The work presented is about the design, the fabrication and the metrology of periodic multilayer mirrors. The main motivation of this study is to establish a cycle of development taking into account both the optical properties of reflective coatings (reflectivity, spectral selectivity, attenuation) and their behaviour under various environments. To improve the spectral selectivity, new multilayer periodic structures have been developed. They are characterized by a bimodal reflectance profile with adjustable attenuation. The effect of environment on the stability of performance is especially critical for the optical collection. The addition of material barriers has stabilized the performance of the peak reflectivity for over 200 h at 400 C deg. and it reduces the influence of other factors of instability on the reflectance. In addition, all structures have been fabricated successfully and evaluated in severe environments. (author)

Analysis of extreme ultraviolet spectra from laser produced rhenium plasmas

International Nuclear Information System (INIS)

Wu, Tao; Dunne, Padraig; O’Reilly, Fergal; Sokell, Emma; Liu, Luning; O’Sullivan, Gerry; Higashiguchi, Takeshi; Suzuki, Yuhei; Arai, Goki; Dinh, Thanh-Hung; Li, Bowen

2015-01-01

Extreme ultraviolet spectra of highly-charged rhenium ions were observed in the 1–7 nm region using two Nd:YAG lasers with pulse lengths of 150 ps and 10 ns, respectively, operating at a number of laser power densities. The maximum focused peak power density was 2.6 × 10 14 W cm −2 for the former and 5.5 × 10 12 W cm −2 for the latter. The Cowan suite of atomic structure codes and unresolved transition array (UTA) approach were used to calculate and interpret the emission properties of the different spectra obtained. The results show that n = 4-n = 4 and n = 4-n = 5 UTAs lead to two intense quasi-continuous emission bands in the 4.3–6.3 nm and 1.5–4.3 nm spectral regions. As a result of the different ion stage distributions in the plasmas induced by ps and ns laser irradiation the 1.5–4.3 nm UTA peak moves to shorter wavelength in the ps laser produced plasma spectra. For the ns spectrum, the most populated ion stage during the lifetime of this plasma that could be identified from the n = 4-n = 5 transitions was Re 23+ while for the ps plasma the presence of significantly higher stages was demonstrated. For the n = 4-n = 4 4p 6 4d N -4p 5 4d N+1  + 4p 6 4d N−1 4f transitions, the 4d-4f transitions contribute mainly in the most intense 4.7–5.5 nm region while the 4p-4d subgroup gives rise to a weaker feature in the 4.3–4.7 nm region. A number of previously unidentified spectral features produced by n = 4-n = 5 transitions in the spectra of Re XVI to Re XXXIX are identified. (paper)

Berkeley automated supernova search

Energy Technology Data Exchange (ETDEWEB)

Kare, J.T.; Pennypacker, C.R.; Muller, R.A.; Mast, T.S.; Crawford, F.S.; Burns, M.S.

1981-01-01

The Berkeley automated supernova search employs a computer controlled 36-inch telescope and charge coupled device (CCD) detector to image 2500 galaxies per night. A dedicated minicomputer compares each galaxy image with stored reference data to identify supernovae in real time. The threshold for detection is m/sub v/ = 18.8. We plan to monitor roughly 500 galaxies in Virgo and closer every night, and an additional 6000 galaxies out to 70 Mpc on a three night cycle. This should yield very early detection of several supernovae per year for detailed study, and reliable premaximum detection of roughly 100 supernovae per year for statistical studies. The search should be operational in mid-1982.

Berkeley automated supernova search

International Nuclear Information System (INIS)

Kare, J.T.; Pennypacker, C.R.; Muller, R.A.; Mast, T.S.

1981-01-01

The Berkeley automated supernova search employs a computer controlled 36-inch telescope and charge coupled device (CCD) detector to image 2500 galaxies per night. A dedicated minicomputer compares each galaxy image with stored reference data to identify supernovae in real time. The threshold for detection is m/sub v/ = 18.8. We plan to monitor roughly 500 galaxies in Virgo and closer every night, and an additional 6000 galaxies out to 70 Mpc on a three night cycle. This should yield very early detection of several supernovae per year for detailed study, and reliable premaximum detection of roughly 100 supernovae per year for statistical studies. The search should be operational in mid-1982

Lawrence Berkeley Laboratory Institutional Plan FY 1995--2000

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-01

This report presents the details of the mission and strategic plan for Lawrence Berkeley Laboratory during the fiscal years of 1995--2000. It presents summaries of current programs and potential changes; critical success factors such as human resources; management practices; budgetary allowances; and technical and administrative initiatives.

Design, conception, and metrology of Extreme Ultraviolet multilayers mirrors resistant environments of space and EUV sources; Conception, realisation et metrologie de miroirs multicouches pour l'extreme ultraviolet resistants aux environnements du spatial et des sources EUV

Energy Technology Data Exchange (ETDEWEB)

Hecquet, Ch.

2009-03-15

The Extreme Ultraviolet Spectrum (EUV) wavelengths, which range between 13 nm and 40 nm, have many applications in science and technology. These have been developed for example in plasma physics (high order harmonics sources, X ray lasers). The work presented is about the design, the fabrication and the metrology of periodic multilayer mirrors. The main motivation of this study is to establish a cycle of development taking into account both the optical properties of reflective coatings (reflectivity, spectral selectivity, attenuation) and their behaviour under various environments. To improve the spectral selectivity, new multilayer periodic structures have been developed. They are characterized by a bimodal reflectance profile with adjustable attenuation. The effect of environment on the stability of performance is especially critical for the optical collection. The addition of material barriers has stabilized the performance of the peak reflectivity for over 200 h at 400 C deg. and it reduces the influence of other factors of instability on the reflectance. In addition, all structures have been fabricated successfully and evaluated in severe environments. (author)

An Intense Traveling Airglow Front in the Upper Mesosphere-Lower Thermosphere with Characteristic of a Turbulent Bore Observed over Alice Springs, Australia

Science.gov (United States)

Walterscheid, R. L.; Hecht, J. H.; Hickey, M. P.; Gelinas, L. J.; Vincent, R. A.; Reid, I. M.; Woithe, J.

2010-12-01

The Aerospace Corporation’s Nightglow Imager observed a large step-function change in airglow in the form of a traveling front in the OH and O2 airglow emissions over Alice Springs Australia on February 2, 2003. The front exhibited a stepwise increase of nearly a factor two in the OH brightness and a stepwise decrease in the O2 brightness. The change in brightness in each layer was associated with a strong leading disturbance followed by a train of weak barely visible waves. The OH airglow brightness behind the front was the brightness night for 02 at Alice Springs that we have measured in seven years of observations. The OH brightness was among the five brightest. The event was associated with a strong phase-locked two-day wave (TDW).We have analyzed the stability conditions for the upper mesosphere and lower thermosphere and found that the airglow layers were found in a region of strong ducting. The thermal structure was obtained from combining data from the SABER instrument on the TIMED satellite and the NRLMSISE-00 model. The wind profile was obtained by combining the HWM07 model and MF radar winds from Buckland Park Australia. We found that the TDW-disturbed profile was significantly more effective in supporting a high degree of ducting than a profile based only on HWM07 winds. Dramatic wall events have been interpreted as manifestations of undular bores (e.g., Smith et al. [2003]). Undular bores are nonlinear high Froude number events that must generate an ever increasing train of waves to carry the excess energy away from the bore front. Only a very weak wave train behind the initial disturbance was seen for the Alice Springs event. The form of the amplitude ordering was not typical of a nonlinear wave train. Therefore a bore interpretation requires another means of energy dissipation, namely turbulent dissipation. We suggest that a reasonable interpretation of the observed event is a turbulent bore. We are unaware of any previous event having

Statistical comparisons of gravity wave features derived from OH airglow and SABER data

Science.gov (United States)

Gelinas, L. J.; Hecht, J. H.; Walterscheid, R. L.

2017-12-01

The Aerospace Corporation's near-IR camera (ANI), deployed at Andes Lidar Observatory (ALO), Cerro Pachon Chile (30S,70W) since 2010, images the bright OH Meinel (4,2) airglow band. The imager provides detailed observations of gravity waves and instability dynamics, as described by Hecht et al. (2014). The camera employs a wide-angle lens that views a 73 by 73 degree region of the sky, approximately 120 km x 120 km at 85 km altitude. Image cadence of 30s allows for detailed spectral analysis of the horizontal components of wave features, including the evolution and decay of instability features. The SABER instrument on NASA's TIMED spacecraft provides remote soundings of kinetic temperature profiles from the lower stratosphere to the lower thermosphere. Horizontal and vertical filtering techniques allow SABER temperatures to be analyzed for gravity wave variances [Walterscheid and Christensen, 2016]. Here we compare the statistical characteristics of horizontal wave spectra, derived from airglow imagery, with vertical wave variances derived from SABER temperature profiles. The analysis is performed for a period of strong mountain wave activity over the Andes spanning the period between June and September 2012. Hecht, J. H., et al. (2014), The life cycle of instability features measured from the Andes Lidar Observatory over Cerro Pachon on March 24, 2012, J. Geophys. Res. Atmos., 119, 8872-8898, doi:10.1002/2014JD021726. Walterscheid, R. L., and A. B. Christensen (2016), Low-latitude gravity wave variances in the mesosphere and lower thermosphere derived from SABER temperature observation and compared with model simulation of waves generated by deep tropical convection, J. Geophys. Res. Atmos., 121, 11,900-11,912, doi:10.1002/2016JD024843.

Berkeley Lab Pilot on External Regulation of DOE National Laboratories by the U.S. NRC

International Nuclear Information System (INIS)

Zeman, Gary H.

1999-01-01

The US Department of Energy and the US Nuclear Regulatory Commission entered into an agreement in November 1997 to pursue external regulation of radiation safety at DOE national laboratories through a Pilot Program of simulated regulation at 6-10 sites over a 2 year period. The Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab), the oldest of the DOE national laboratories, volunteered and was selected as the first Pilot site. Based on the similarities and linkages between Berkeley Lab and nearby university research laboratories, Berkeley Lab seemed a good candidate for external regulation and a good first step in familiarizing NRC with the technical and institutional issues involved in regulating laboratories in the DOE complex. NRC and DOE team members visited Berkeley Lab on four occasions between October 1997 and January 1998 to carry out the Pilot. The first step was to develop a detailed Work Plan, then to carry out both a technical review of the radiation safety program and an examination of policy and regulatory issues. The Pilot included a public meeting held in Oakland, CA in December 1997. The Pilot concluded with NRC's assessment that Berkeley Lab has a radiation protection program adequate to protect workers, the public and the environment, and that it is ready to be licensed by the NRC with minor programmatic exceptions. A draft final report of the Pilot was prepared and circulated for comment as a NUREG document (dated May 7, 1998). The report's recommendations include extending NRC regulatory authority to cover all ionizing radiation sources (including accelerators, x-ray units, NARM) at Berkeley Lab. Questions remaining to be resolved include: who should be the licensee (DOE, the Lab, or both)?; dealing with legacy issues and NRC D and D requirements; minimizing dual oversight; quantifying value added in terms of cost savings, enhanced safety, and improved public perception; extrapolating results to other national laboratories; and

Use of O2 airglow for calibrating direct atomic oxygen measurements from sounding rockets

Directory of Open Access Journals (Sweden)

G. Witt

2009-12-01

Full Text Available Accurate knowledge about the distribution of atomic oxygen is crucial for many studies of the mesosphere and lower thermosphere. Direct measurements of atomic oxygen by the resonance fluorescence technique at 130 nm have been made from many sounding rocket payloads in the past. This measurement technique yields atomic oxygen profiles with good sensitivity and altitude resolution. However, accuracy is a problem as calibration and aerodynamics make the quantitative analysis challenging. Most often, accuracies better than a factor 2 are not to be expected from direct atomic oxygen measurements. As an example, we present results from the NLTE (Non Local Thermodynamic Equilibrium sounding rocket campaign at Esrange, Sweden, in 1998, with simultaneous O2 airglow and O resonance fluorescence measurements. O number densities are found to be consistent with the nightglow analysis, but only within the uncertainty limits of the resonance fluorescence technique. Based on these results, we here describe how better atomic oxygen number densities can be obtained by calibrating direct techniques with complementary airglow photometer measurements and detailed aerodynamic analysis. Night-time direct O measurements can be complemented by photometric detection of the O2 (b1∑g+−X3∑g- Atmospheric Band at 762 nm, while during daytime the O2 (a1Δg−X3∑g- Infrared Atmospheric Band at 1.27 μm can be used. The combination of a photometer and a rather simple resonance fluorescence probe can provide atomic oxygen profiles with both good accuracy and good height resolution.

Studies of the polar MLT region using SATI airglow measurements

Science.gov (United States)

Cho, Youngmin

To investigate atmospheric dynamics of the MLT (Mesosphere and Lower Thermosphere) region, a ground-based instrument called SATI (Spectral Airglow Temperature Imager) was developed at York University. The rotational temperatures and emission rates of the OH (6-2) Meinel band and the O2 (0-1) Atmospheric band have been measured in the MLT region by the SATI instrument at Resolute Bay (74.68°N, 94.90°W) since November, 2001, and at the King Sejong station (62.22°S, 58.75°W) since February, 2002. The MLT measurements are examined for periodic oscillations in the ambient temperature and airglow emission rate. A dominant and coherent 4-hr oscillation is seen in both the OH and O2 temperature and emission rate at Resolute Bay in November, 2001. Tidal variation with a 12 hour period is shown in hourly averaged temperatures of the season 2001--2002 and the season 2003--2004. In addition, planetary waves with periods of 3 and 4.5 days are also seen in a longer interval. The observations at high latitudes have revealed that temperatures and emission rates are higher around the winter solstice. MLT cooling events were found at Resolute Bay in December, 2001 and February, 2002. They are compared with the UKMO (UK Meteorological Office) stratospheric assimilated data, and the MLT coolings coincide in time with the stratospheric warmings. A consistent inverse relationship of the OH temperatures and temperatures at 0.316 hPa is presented in the comparison. In previous studies of wave perturbations, the background (mean) values were normally subtracted from the instantaneous signal, but in the present investigation this was not done, allowing the long-term relationship to be examined. A positive relationship of the temperature and emission rate is seen from the SATI measurements for both short and long-term variations, suggesting that similar dynamical processes are responsible for both. This relationship is supported by satellite data from the SABER (Sounding of the

Ultraviolet spectrophotometry from Gemini 11 of stars in Orion

International Nuclear Information System (INIS)

Morgan, T.H.; Spear, G.G.; Kondo, Y.; Henize, K.G.

1975-01-01

Ultraviolet spectrophotometry in the wavelength region 2600--3600 A is reported for the bright early-type stars β, eta, γ, delta, iota, epsilon, sigma, xi, and kappa Ori. The results are in good agreement with other observations, and with the possible exception of the supergiants, are in good agreement with recent line-blanketed model atmospheres. There is evidence that the supergiants possess a small ultraviolet deficiency shortward of 3000 A relative to main-sequence stars of similar spectral type. The most extreme example of this phenomenon is the star kappa Ori

Lawrence Berkeley National Laboratory 2016 Annual Financial Report

Energy Technology Data Exchange (ETDEWEB)

Williams, Kim, P.; Williams, Kim, P.

2017-06-27

FY2016 was a year of significant change and progress at Berkeley Lab. In March, Laboratory Director Michael Witherell assumed his new role when former Lab Director Paul Alivisatos became Vice Chancellor for Research at UC Berkeley. Dr. Witherell has solidified the Lab’s strategy, with a focus on long term science and technology priorities. Large-scale science efforts continued to expand at the Lab, including the Dark Energy Spectroscopic Instrument now heading towards construction, and the LUX-ZEPLIN dark matter detector to be built underground in South Dakota. Another proposed project, the Advanced Light Source-Upgrade, was given preliminary approval and will be the Lab’s largest scientific investment in years. Construction of the Integrative Genomics Building began, and will bring together researchers from the Lab’s Joint Genome Institute, now based in Walnut Creek, and the Systems Biology Knowledgebase (K-Base) under one roof. Investment in the Lab’s infrastructure also continues, informed by the Lab’s Infrastructure Strategic Plan. Another important focus is on developing the next generation of scientists with the talent and diversity needed to sustain Berkeley Lab’s scientific leadership and mission contributions to DOE and the Nation. Berkeley Lab received $897.5M in new FY2016 funding, a 12.5% increase over FY2015, for both programmatic and infrastructure activities. While the Laboratory experienced a substantial increase in funding, it was accompanied by only a modest increase in spending, as areas of growth were partially offset by the completion of several major efforts in FY2015. FY2016 costs were $826.9M, an increase of 1.9% over FY2015. Similar to the prior year, the indirect-funded Operations units worked with generally flat budgets to yield more funding for strategic needs. A key challenge for Berkeley Lab continues to be achieving the best balance to fund essential investments, deliver highly effective operational mission support and

Annual environmental monitoring report of the Lawrence Berkeley Laboratory, 1980

International Nuclear Information System (INIS)

Schleimer, G.E.

1981-04-01

The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data on air and water sampling and continuous radiation monitoring for 1980 are presented, and general trends are discussed

Berkeley Lab Computing Sciences: Accelerating Scientific Discovery

International Nuclear Information System (INIS)

Hules, John A.

2008-01-01

Scientists today rely on advances in computer science, mathematics, and computational science, as well as large-scale computing and networking facilities, to increase our understanding of ourselves, our planet, and our universe. Berkeley Lab's Computing Sciences organization researches, develops, and deploys new tools and technologies to meet these needs and to advance research in such areas as global climate change, combustion, fusion energy, nanotechnology, biology, and astrophysics

Electron impact collision strengths and transition rates for extreme ultraviolet emission from Xe10+

International Nuclear Information System (INIS)

Shen Yunfeng; Gao Cheng; Zeng Jiaolong

2009-01-01

The energy levels, oscillator strengths, and electron impact collision strengths are calculated for the Xe 10+ ion using the configuration interaction scheme implemented by the Flexible Atomic Code. These data pertain to the 3917 levels belonging to the following configurations: 4s 2 4p 6 4d 8 , 4s 2 4p 6 4d 7 4f, 4s 2 4p 6 4d 7 5l (l = s, p, d, or f), 4s 2 4p 5 4d 9 , 4s 2 4p 5 4d 8 4f, 4s 2 4p 5 4d 8 5l, 4s 2 4p 6 4d 6 5s5p, 4s 2 4p 6 4d 6 5p5d. Configuration interactions among these configurations are included in the calculation. Collision strengths are obtained at 10 scattered electron energies (1-1000 eV) and are tabulated here at five representative energies of 10, 50, 100, 500, and 1000 eV. Effective collision strengths are obtained by assuming a Maxwellian electron velocity distribution at 10 temperatures ranging from 10 to 100 eV, and are tabulated at five representative temperatures of 10, 30, 50, 70 and 100 eV in this work. The whole data set should be useful for research involving extreme ultraviolet emission from Xe 10+

On the Importance of the Flare's Late Phase for the Solar Extreme Ultraviolet Irradiance

Science.gov (United States)

Woods, Thomas N.; Eparvier, Frank; Jones, Andrew R.; Hock, Rachel; Chamberlin, Phillip C.; Klimchuk, James A.; Didkovsky, Leonid; Judge, Darrell; Mariska, John; Bailey, Scott;

Effects of antibiotics and ultraviolet radiation on the halophilic blue-green alga

International Nuclear Information System (INIS)

Yopp, J.H.; Albright, G.; Miller, D.M.; Southern Illinois Univ., Carbondale

1979-01-01

The effects of a variety of antibiotics, ultraviolet radiation and N-methyl-N-nitro-N-nitro-N-nitrosoguanidine (NTG) on the survival and mutability of the halophilic blue-green alga, Aphanothece halophytica, were determined. The halophile was found extremely sensitive to penicillin G and bacitracin; moderately sensitive to novobiocin, amino acid analogs, chloramphenicol and streptomycin; and tolerant to actidione and hydroxyurea. Ultraviolet and NTG killing curves and photoreactivation capabilities were seimilar to those reported for other members of the Chroococcales. Three stable morphological mutants were obtained by ultraviolet and NTG treatment, the latter being much more efficient in the production of mutants. (orig.)

Long-life cathode for the Berkeley-type ion source

International Nuclear Information System (INIS)

Fink, J.H.; Biagi, L.A.

1977-01-01

Preliminary experiments indicate that a hollow cathode, made from impregnated tungsten emitters, can be adapted for the Lawrence Berkeley Laboratory (LBL)/Lawrence Livermore Laboratory (LLL) ion source. Such cathodes could be the basis of a long life, continuously operated positive-ion source

Laser-assisted vacuum arc extreme ultraviolet source: a comparison of picosecond and nanosecond laser triggering

Science.gov (United States)

Beyene, Girum A.; Tobin, Isaac; Juschkin, Larissa; Hayden, Patrick; O'Sullivan, Gerry; Sokell, Emma; Zakharov, Vassily S.; Zakharov, Sergey V.; O'Reilly, Fergal

2016-06-01

Extreme ultraviolet (EUV) light generation by hybrid laser-assisted vacuum arc discharge plasmas, utilizing Sn-coated rotating-disc-electrodes, was investigated. The discharge was initiated by localized ablation of the liquid tin coating of the cathode disc by a laser pulse. The laser pulse, at 1064 nm, was generated by Nd:YAG lasers with variable energy from 1 to 100 mJ per pulse. The impact of shortening the laser pulse from 7 ns to 170 ps on the EUV generation has been investigated in detail. The use of ps pulses resulted in an increase in emission of EUV radiation. With a fixed discharge energy of ~4 J, the EUV conversion efficiency tends to plateau at ~2.4  ±  0.25% for the ps laser pulses, while for the ns pulses, it saturates at ~1.7  ±  0.3%. Under similar discharge and laser energy conditions, operating the EUV source with the ps-triggering resulted also in narrower spectral profiles of the emission in comparison to ns-triggering. The results indicate an advantage in using ps-triggering in laser-assisted discharges to produce brighter plasmas required for applications such as metrology.

Extreme ultraviolet emission and confinement of tin plasmas in the presence of a magnetic field

Energy Technology Data Exchange (ETDEWEB)

Roy, Amitava, E-mail: roy@fzu.cz, E-mail: aroy@barc.gov.in [School of Nuclear Engineering and Center for Materials Under Extreme Environment(CMUXE), Purdue University, West Lafayette, Indiana 47907 (United States); HiLASE Project, Department of Diode-pumped Lasers, Institute of Physics of the ASCR, Na Slovance 2, 18221 Prague (Czech Republic); Murtaza Hassan, Syed; Harilal, Sivanandan S.; Hassanein, Ahmed [School of Nuclear Engineering and Center for Materials Under Extreme Environment(CMUXE), Purdue University, West Lafayette, Indiana 47907 (United States); Endo, Akira; Mocek, Tomas [HiLASE Project, Department of Diode-pumped Lasers, Institute of Physics of the ASCR, Na Slovance 2, 18221 Prague (Czech Republic)

2014-05-15

We investigated the role of a guiding magnetic field on extreme ultraviolet (EUV) and ion emission from a laser produced Sn plasma for various laser pulse duration and intensity. For producing plasmas, planar slabs of pure Sn were irradiated with 1064 nm, Nd:YAG laser pulses with varying pulse duration (5–15 ns) and intensity. A magnetic trap was fabricated with the use of two neodymium permanent magnets which provided a magnetic field strength ∼0.5 T along the plume expansion direction. Our results indicate that the EUV conversion efficiency do not depend significantly on applied axial magnetic field. Faraday Cup ion analysis of Sn plasma show that the ion flux reduces by a factor of ∼5 with the application of an axial magnetic field. It was found that the plasma plume expand in the lateral direction with peak velocity measured to be ∼1.2 cm/μs and reduced to ∼0.75 cm/μs with the application of an axial magnetic field. The plume expansion features recorded using fast photography in the presence and absence of 0.5 T axial magnetic field are simulated using particle-in-cell code. Our simulation results qualitatively predict the plasma behavior.

Characterization of extreme ultraviolet light-emitting plasmas from a laser-excited fluorine containing liquid polymer jet target

International Nuclear Information System (INIS)

Abel, B.; Assmann, J.; Faubel, M.; Gaebel, K.; Kranzusch, S.; Lugovoj, E.; Mann, K.; Missalla, T.; Peth, Ch.

2004-01-01

The operation of a liquid polymer jet laser-plasma target and the characterization of the absolute x-ray emission in the extreme ultraviolet wavelength window from 9-19 nm is reported. The target is a liquid polymer (perfluoro-polyether) that is exposed to pulsed and focused laser light at 532 nm in the form of a thin, liquid microjet (d=40 to 160 μm) in vacuum. The spectral brightness of the source in the 13 nm range is relatively high because a large fraction of radiative energy is emitted in one single line only, which is assigned to be the 2p-3d F VII doublet at 12.8 nm, with a laser energy conversion efficiency of 0.45% (2π sr, 2% bandwidth) in our initial experiment. A further increase of the relative emission has been found in the wavelength range between 7 and 17 nm when the jet diameter was increased from 40 to 160 μm. The two-dimensional spatial profile of the source plasma (d=40 to 50 μm) has been analyzed with a pinhole camera

Lawrence Berkeley Laboratory 1993 Site Environmental Report

Energy Technology Data Exchange (ETDEWEB)

1994-05-01

This annual Site Environmental Report summarizes Lawrence Berkeley Laboratory`s (LBL`s) environmental activities in calendar year (CY) 1993. The purpose of this report is to characterize site environmental management performance, confirm compliance status with environmental standards and requirements, and highlight significant programs and efforts. Its format and content are consistent with the requirements of the US Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

The decommissioning of Berkeley II

International Nuclear Information System (INIS)

Hannan, A.

2002-01-01

This paper describes the decommissioning progress at the Magnox site at Berkeley in Gloucestershire.Throughout the work at Berkeley the emphasis has been on conducting decommissioning safely. This has been reflected in the progress of decommissioning starting with removal of the fuel from site and thus much greater than 99% of the radioactive inventory. The major radioactive hazard is the Intermediate Level Waste in the form of fuel element debris (graphite struts and extraneous magnox components removed to increase the packing density of fuel elements in flasks going to Sellafield), miscellaneous activated components, sludges and resins. Approximately 1500 m 3 of such material exists and is stored in underground waste vaults on site. Work is underway to recover and encapsulate the waste in cement so rendering it 'passively safe'. All work on site is covered by a nuclear safety case which has a key objective of minimising the radiological exposures that could accrue to workers. Reflecting this an early decision has been taken to leave work on the Reactor Pressure Vessels themselves for several decades. Also important in protection of the workforce has been control of asbestos.Much material has been removed with redundant plant and equipment, but a programme of remediation in line with government legislation has been required to ensure personnel safety throughout the decommissioning period and into Care and Maintenance.In addition to health and safety matters the site approach to environmental issues has been consistent. Formally such standards as ISO 14001 have been adhered to and the appropriate certification maintained. At a working level the principles of reduce, reuse and recycle have been inculcated

Analysis of buried interfaces in multilayer mirrors using grazing incidence extreme ultraviolet reflectometry near resonance edges.

Science.gov (United States)

Sertsu, M G; Nardello, M; Giglia, A; Corso, A J; Maurizio, C; Juschkin, L; Nicolosi, P

2015-12-10

Accurate measurements of optical properties of multilayer (ML) mirrors and chemical compositions of interdiffusion layers are particularly challenging to date. In this work, an innovative and nondestructive experimental characterization method for multilayers is discussed. The method is based on extreme ultraviolet (EUV) reflectivity measurements performed on a wide grazing incidence angular range at an energy near the absorption resonance edge of low-Z elements in the ML components. This experimental method combined with the underlying physical phenomenon of abrupt changes of optical constants near EUV resonance edges enables us to characterize optical and structural properties of multilayers with high sensitivity. A major advantage of the method is to perform detailed quantitative analysis of buried interfaces of multilayer structures in a nondestructive and nonimaging setup. Coatings of Si/Mo multilayers on a Si substrate with period d=16.4  nm, number of bilayers N=25, and different capping structures are investigated. Stoichiometric compositions of Si-on-Mo and Mo-on-Si interface diffusion layers are derived. Effects of surface oxidation reactions and carbon contaminations on the optical constants of capping layers and the impact of neighboring atoms' interactions on optical responses of Si and Mo layers are discussed.

UC-Berkeley-area citizens decry waste transfer from lab.

CERN Multimedia

Nakasato, L

2002-01-01

Residents are working to stop the transfer of potentially hazardous and radioactive material from Lawrence Berkeley National Laboratory. The lab has begun to dismantle the Bevatron which has been shut down since 1993 and says eight trucks per day will move material offsite (1 page).

First Study on the Occurrence Frequency of Equatorial Plasma Bubbles over West Africa Using an All-Sky Airglow Imager and GNSS Receivers

Science.gov (United States)

Okoh, Daniel; Rabiu, Babatunde; Shiokawa, Kazuo; Otsuka, Yuichi; Segun, Bolaji; Falayi, Elijah; Onwuneme, Sylvester; Kaka, Rafiat

2017-12-01

This is the first paper that reports the occurrence frequency of equatorial plasma bubbles and their dependences of local time, season, and geomagnetic activity based on airglow imaging observations at West Africa. The all-sky imager, situated in Abuja (Geographic: 8.99°N, 7.38°E; Geomagnetic: 1.60°S), has a 180° fisheye view covering almost the entire airspace of Nigeria. Plasma bubbles are observed for 70 nights of the 147 clear-sky nights from 9 June 2015 to 31 January 2017. Differences between nighttime and daytime ROTIs were also computed as a proxy of plasma bubbles using Global Navigation Satellite Systems (GNSS) receivers within the coverage of the all-sky imager. Most plasma bubble occurrences are found during equinoxes and least occurrences during solstices. The occurrence rate of plasma bubbles was highest around local midnight and lower for hours farther away. Most of the postmidnight plasma bubbles were observed around the months of December to March, a period that coincides with the harmattan period in Nigeria. The on/off status of plasma bubble in airglow and GNSS observations were in agreement for 67.2% of the total 768 h, while we suggest several reasons responsible for the remaining 32.8% when the airglow and GNSS bubble status are inconsistent. A majority of the plasma bubbles were observed under relatively quiet geomagnetic conditions (Dst ≥ -40 and Kp ≤ 3), but there was no significant pattern observed in the occurrence rate of plasma bubbles as a function of geomagnetic activity. We suggest that geomagnetic activities could have either suppressed or promoted the occurrence of plasma bubbles.

Reply to “Comment on ‘Ultrafast Demagnetization Measurements Using Extreme Ultraviolet Light: Comparison of Electronic and Magnetic Contributions’ ”

Directory of Open Access Journals (Sweden)

Emrah Turgut

2013-09-01

Full Text Available In the following, we show that the conclusions of our article titled “Ultrafast Demagnetization Measurements Using Extreme Ultraviolet Light: Comparison of Electronic and Magnetic Contributions” are correct. The Comment of Vodungbo et al. argues that a unique determination of the refractive index variation over time is not possible using the data set presented in our paper. Furthermore, it was suggested that the lack of uniqueness allows for the possibility of a very specific time-dependent trajectory of the refractive index in the complex plane that could give rise to a large nonmagnetic modulation of the measured asymmetry, in spite of a negligible change in the s-polarized reflectivity. In this Reply, we conclusively show that any nonmagnetic contribution to the measured asymmetry is indeed negligible (<2%, below the noise level of the magnetic-asymmetry measurements. First, we use a few additional measurements to unambiguously rule out the presence of any nonmagnetic contributions to the signal. Second, we show that the scenario proposed by Vodungbo et al. would require both exotic time and energy dependences of the refractive index near the M edge that are extremely unlikely (virtually impossible in real materials. Thus, the conclusions of our original article are preserved.

Progress in coherent lithography using table-top extreme ultraviolet lasers

Science.gov (United States)

Li, Wei

Nanotechnology has drawn a wide variety of attention as interesting phenomena occurs when the dimension of the structures is in the nanometer scale. The particular characteristics of nanoscale structures had enabled new applications in different fields in science and technology. Our capability to fabricate these nanostructures routinely for sure will impact the advancement of nanoscience. Apart from the high volume manufacturing in semiconductor industry, a small-scale but reliable nanofabrication tool can dramatically help the research in the field of nanotechnology. This dissertation describes alternative extreme ultraviolet (EUV) lithography techniques which combine table-top EUV laser and various cost-effective imaging strategies. For each technique, numerical simulations, system design, experiment result and its analysis will be presented. In chapter II, a brief review of the main characteristics of table-top EUV lasers will be addressed concentrating on its high power and large coherence radius that enable the lithography application described herein. The development of a Talbot EUV lithography system which is capable of printing 50nm half pitch nanopatterns will be illustrated in chapter III. A detailed discussion of its resolution limit will be presented followed by the development of X-Y-Z positioning stage, the fabrication protocol for diffractive EUV mask, and the pattern transfer using self- developed ion beam etching, and the dose control unit. In addition, this dissertation demonstrated the capability to fabricate functional periodic nanostructures using Talbot EUV lithography. After that, resolution enhancement techniques like multiple exposure, displacement Talbot EUV lithography, fractional Talbot EUV lithography, and Talbot lithography using 18.9nm amplified spontaneous emission laser will be demonstrated. Chapter IV will describe a hybrid EUV lithography which combines the Talbot imaging and interference lithography rendering a high resolution

The Indirect Perception of Distance: Interpretive Complexities in Berkeley's Theory of Vision

Directory of Open Access Journals (Sweden)

Michael James Braund

2007-12-01

Full Text Available The problem of whether perception is direct or if it depends on additional, cognitive contributions made by the perceiving subject, is posed with particular force in an Essay towards a New Theory of Vision (NTV. It is evident from the recurrent treatment it receives therein that Berkeley considers it to be one of the central issues concerning perception. Fittingly, the NTV devotes the most attention to it. In this essay, I deal exclusively with Berkeley's treatment of the problem of indirect distance perception, as it is presented in the context of that work.

Intermittency of gravity wave momentum flux in the mesopause region observed with an all-sky airglow imager

Science.gov (United States)

Cao, Bing; Liu, Alan Z.

2016-01-01

The intermittency of gravity wave momentum flux (MF) near the OH airglow layer (˜87 km) in the mesopause region is investigated for the first time using observation of all-sky airglow imager over Maui, Hawaii (20.7°N, 156.3°W), and Cerro Pachón, Chile (30.3°S, 70.7°W). At both sites, the probability density function (pdf) of gravity wave MF shows two distinct distributions depending on the magnitude of the MF. For MF smaller (larger) than ˜16 m2 s-2 (0.091 mPa), the pdf follows a lognormal (power law) distribution. The intermittency represented by the Bernoulli proxy and the percentile ratio shows that gravity waves have higher intermittency at Maui than at Cerro Pachón, suggesting more intermittent background variation above Maui. It is found that most of the MF is contributed by waves that occur very infrequently. But waves that individually contribute little MF are also important because of their higher occurrence frequencies. The peak contribution is from waves with MF around ˜2.2 m2 s-2 at Cerro Pachón and ˜5.5 m2 s-2 at Maui. Seasonal variations of the pdf and intermittency imply that the background atmosphere has larger influence on the observed intermittency in the mesopause region.

Ion beam deposition system for depositing low defect density extreme ultraviolet mask blanks

Science.gov (United States)

Jindal, V.; Kearney, P.; Sohn, J.; Harris-Jones, J.; John, A.; Godwin, M.; Antohe, A.; Teki, R.; Ma, A.; Goodwin, F.; Weaver, A.; Teora, P.

2012-03-01

Extreme ultraviolet lithography (EUVL) is the leading next-generation lithography (NGL) technology to succeed optical lithography at the 22 nm node and beyond. EUVL requires a low defect density reflective mask blank, which is considered to be one of the top two critical technology gaps for commercialization of the technology. At the SEMATECH Mask Blank Development Center (MBDC), research on defect reduction in EUV mask blanks is being pursued using the Veeco Nexus deposition tool. The defect performance of this tool is one of the factors limiting the availability of defect-free EUVL mask blanks. SEMATECH identified the key components in the ion beam deposition system that is currently impeding the reduction of defect density and the yield of EUV mask blanks. SEMATECH's current research is focused on in-house tool components to reduce their contributions to mask blank defects. SEMATECH is also working closely with the supplier to incorporate this learning into a next-generation deposition tool. This paper will describe requirements for the next-generation tool that are essential to realize low defect density EUV mask blanks. The goal of our work is to enable model-based predictions of defect performance and defect improvement for targeted process improvement and component learning to feed into the new deposition tool design. This paper will also highlight the defect reduction resulting from process improvements and the restrictions inherent in the current tool geometry and components that are an impediment to meeting HVM quality EUV mask blanks will be outlined.

Environmental Assessment for the proposed Induction Linac System Experiments in Building 51B at Lawrence Berkeley National Laboratory, Berkeley, California

International Nuclear Information System (INIS)

1995-08-01

The US Department of Energy (DOE) has prepared an Environmental Assessment (EA), (DOE/EA-1087) evaluating the proposed action to modify existing Building 51B at Lawrence Berkeley National Laboratory (LBNL) to install and conduct experiments on a new Induction Linear Accelerator System. LBNL is located in Berkeley, California and operated by the University of California (UC). The project consists of placing a pre-fabricated building inside Building 51B to house a new 10 MeV heavy ion linear accelerator. A control room and other support areas would be provided within and directly adjacent to Building 51B. The accelerator system would be used to conduct tests, at reduced scale and cost, many features of a heavy-ion accelerator driver for the Department of Energy's inertial fusion energy program. Based upon information and analyses in the EA, the DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969. Therefore, an Environmental Impact Statement is not required. This report contains the Environmental Assessment, as well as the Finding of No Significant Impact (FONSI)

Measurements of the Michigan Airglow Observatory from 1971 to 1973 at Ester Dome Alaska

Science.gov (United States)

Mcwatters, K. D.; Meriwether, J. W.; Hays, P. B.; Nagy, A. F.

1973-01-01

The Michigan Airglow Observatory (MAO) was located at Ester Dome Observatory, College, Alaska (latitude: 64 deg 53'N, longitude: 148 deg 03'W) since October, 1971. The MAO houses a 6-inch Fabry-Perot interferometer, a 2-channel monitoring photometer and a 4-channel tilting filter photometer. The Fabry-Perot interferometer was used extensively during the winter observing seasons of 1971-72 and 1972-73 to measure temperature and mass motions of the neutral atmosphere above approximately 90 kilometers altitude. Neutral wind data from the 1971-72 observing season as measured by observing the Doppler shift of the gamma 6300 A atomic oxygen emission line are presented.

New nuclear physics at Berkeley Conference

International Nuclear Information System (INIS)

Anon.

1980-01-01

One of the highlights of the summer was the International Conference on Nuclear Physics, held at Berkeley in August. These big meetings provide a periodic focus for the nuclear physics community. Overall, the Conference paid a lot of attention to topics and phenomna which only a few years ago would have been considered exotic. With many novel ideas being put forward and with new projects afoot, a lot of fresh ground could have been covered by the time of the next meeting, scheduled to be held in Florence in a few years

Environmental assessment for construction and operation of a Human Genome Laboratory at Lawrence Berkeley Laboratory, Berkeley, California

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-01

Lawrence Berkeley Laboratory (LBL) proposes to construct and operate a new laboratory for consolidation of current and future activities of the Human Genome Center (HGC). This document addresses the potential direct, indirect, and cumulative environmental and human-health effects from the proposed facility construction and operation. This document was prepared in accordance the National Environmental Policy Act of 1969 (United States Codes 42 USC 4321-4347) (NEPA) and the US Department of Energy`s (DOE) Final Rule for NEPA Implementing Procedures [Code of Federal Regulations 10CFR 1021].

Harmonium: A pulse preserving source of monochromatic extreme ultraviolet (30–110 eV radiation for ultrafast photoelectron spectroscopy of liquids

Directory of Open Access Journals (Sweden)

J. Ojeda

2016-03-01

Full Text Available A tuneable repetition rate extreme ultraviolet source (Harmonium for time resolved photoelectron spectroscopy of liquids is presented. High harmonic generation produces 30–110 eV photons, with fluxes ranging from ∼2 × 1011 photons/s at 36 eV to ∼2 × 108 photons/s at 100 eV. Four different gratings in a time-preserving grating monochromator provide either high energy resolution (0.2 eV or high temporal resolution (40 fs between 30 and 110 eV. Laser assisted photoemission was used to measure the temporal response of the system. Vibrational progressions in gas phase water were measured demonstrating the ∼0.2 eV energy resolution.

Seasonal Variations of Mesospheric Gravity Waves Observed with an Airglow All-sky Camera at Mt. Bohyun, Korea (36° N

Directory of Open Access Journals (Sweden)

Yong Ha Kim

2010-09-01

Full Text Available We have carried out all-sky imaging of OH Meinel, O2 atmospheric and OI 557.7 nm airglow layers in the period from July of 2001 through September of 2005 at Mt. Bohyun, Korea (36.2° N, 128.9° E, Alt = 1,124 m. We analyzed the images observed during a total of 153 clear moonless nights and found 97 events of band-type waves. The characteristics of the observed waves (wavelengths, periods, and phase speeds are consistent with internal gravity waves. The wave occurrence shows an approximately semi-annual variation, with maxima near solstices and minima near equinoxes, which is consistent with other studies of airglow wave observations, but not with those of mesospheric radar/lidar observations. The observed waves tended to propagate westward during fall and winter, and eastward during spring and summer. Our ray tracing study of the observed waves shows that majority of the observed waves seemed to originate from mesospheric altitudes. The preferential directions and the apparent source altitudes can be explained if the observed waves are secondary waves generated from primary waves that have been selected by the filtering process and break up at the mesospheric altitudes.

Wavefront measurement of single-mode quantum cascade laser beam for seed application in laser-produced plasma extreme ultraviolet system.

Science.gov (United States)

Nowak, Krzysztof M; Ohta, Takeshi; Suganuma, Takashi; Yokotsuka, Toshio; Fujimoto, Junichi; Mizoguchi, Hakaru

2012-12-01

Quantum cascade laser (QCL) is a very attractive seed source for a multikilowatt pulsed CO2 lasers applied for driving extreme ultraviolet emitting plasmas. In this Letter, we investigate output beam properties of a QCL designed to address P18 and P20 lines of 10.6 micron band of CO2 molecule. In particular, output beam quality and stability are investigated for the first time. A well-defined linear polarization and a single-mode operation enabled a use of phase retrieval method for full description of QCL output beam. A direct, multi-image numerical phase retrieval technique was developed and successfully applied to the measured intensity patterns of a QCL beam. Very good agreement between the measured and reconstructed beam profiles was observed at distances ranging from QCL aperture to infinity, proving a good understanding of the beam propagation. The results also confirm a high spatial coherence and high stability of the beam parameters, the features expected from an excellent seed source.

Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

International Nuclear Information System (INIS)

Perez, C.F.

1984-08-01

The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT + colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references

Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

Energy Technology Data Exchange (ETDEWEB)

Perez, C.F.

1984-08-01

The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT/sup +/ colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references.

Annual environmental monitoring report of the Lawrence Berkeley Laboratory, 1986

International Nuclear Information System (INIS)

Schleimer, G.E.

1987-04-01

The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data for 1986 are presented and general trends are discussed. Topics include radiation monitoring, wastewater discharge monitoring, dose distribution estimates, and ground water monitoring. 9 refs., 8 figs., 20 tabs

Tidal variations of O2 Atmospheric and OH(6-2 airglow and temperature at mid-latitudes from SATI observations

Directory of Open Access Journals (Sweden)

M. J. López-González

2005-12-01

Full Text Available Airglow observations with a Spectral Airglow Temperature Imager (SATI, installed at the Sierra Nevada Observatory (37.06° N, 3.38° W at 2900-m height, have been used to investigate the presence of tidal variations at mid-latitudes in the mesosphere/lower thermosphere region. Diurnal variations of the column emission rate and vertically averaged temperature of the O2 Atmospheric (0-1 band and of the OH Meinel (6-2 band from 5 years (1998-2003 of observations have been analysed. From these observations a clear tidal variation of both emission rates and rotational temperatures is inferred. It is found that the amplitude of the daily variation for both emission rates and temperatures is greater from late autumn to spring than during summer. The amplitude decreases by more than a factor of two during summer and early autumn with respect to the amplitude in the winter-spring months. Although the tidal modulations are preferentially semidiurnal in both rotational temperatures and emission rates during the whole year, during early spring the tidal modulations seem to be more consistent with a diurnal modulation in both rotational temperatures and emission rates. Moreover, the OH emission rate from late autumn to early winter has a pattern suggesting both diurnal and semidiurnal tidal modulations.

Environmental health-risk assessment for tritium releases at the National Tritium Labeling Facility at Lawrence Berkeley National Laboratory

Energy Technology Data Exchange (ETDEWEB)

McKone, T.E.; Brand, K.P. [Lawrence Livermore National Lab., CA (United States). Health and Ecological Assessment Div.; Shan, C. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.

1997-04-01

This risk assessment calculates the probability of experiencing health effects, including cancer incidence due to tritium exposure for three groups of people: (1) LBNL workers near the LBNL facility--Building 75--that uses tritium; (2) other workers at LBNL and nearby neighbors; and (3) people who use the UC Berkeley campus area, and some Berkeley residents. All of these groups share the same probability of health effects from the background radiation from natural sources in the Berkeley area environment, including an increased risk of developing a cancer of 11,000 chances per million. In calculating risk the authors assumed continuous operation in Building 75 for at least a human lifetime. Under this assumption, LBNL workers located near Building 75 have an additional risk of 60 chances out of one million to suffer a cancer; other workers at LBNL and people who live near LBNL have an additional risk of six chances out of one million over a lifetime of exposure; and users of the UC Berkeley campus area and other residents of Berkeley have an additional risk of less than once chance out of one million over a lifetime.

Environmental health-risk assessment for tritium releases at the National Tritium Labeling Facility at Lawrence Berkeley National Laboratory

International Nuclear Information System (INIS)

McKone, T.E.; Brand, K.P.; Shan, C.

1997-04-01

This risk assessment calculates the probability of experiencing health effects, including cancer incidence due to tritium exposure for three groups of people: (1) LBNL workers near the LBNL facility--Building 75--that uses tritium; (2) other workers at LBNL and nearby neighbors; and (3) people who use the UC Berkeley campus area, and some Berkeley residents. All of these groups share the same probability of health effects from the background radiation from natural sources in the Berkeley area environment, including an increased risk of developing a cancer of 11,000 chances per million. In calculating risk the authors assumed continuous operation in Building 75 for at least a human lifetime. Under this assumption, LBNL workers located near Building 75 have an additional risk of 60 chances out of one million to suffer a cancer; other workers at LBNL and people who live near LBNL have an additional risk of six chances out of one million over a lifetime of exposure; and users of the UC Berkeley campus area and other residents of Berkeley have an additional risk of less than once chance out of one million over a lifetime

The airglow layer emission altitude cannot be determined unambiguously from temperature comparison with lidars

Science.gov (United States)

Dunker, Tim

2018-05-01

I investigate the nightly mean emission height and width of the OH* (3-1) layer by comparing nightly mean temperatures measured by the ground-based spectrometer GRIPS 9 and the Na lidar at ALOMAR. The data set contains 42 coincident measurements taken between November 2010 and February 2014, when GRIPS 9 was in operation at the ALOMAR observatory (69.3° N, 16.0° E) in northern Norway. To closely resemble the mean temperature measured by GRIPS 9, I weight each nightly mean temperature profile measured by the lidar using Gaussian distributions with 40 different centre altitudes and 40 different full widths at half maximum. In principle, one can thus determine the altitude and width of an airglow layer by finding the minimum temperature difference between the two instruments. On most nights, several combinations of centre altitude and width yield a temperature difference of ±2 K. The generally assumed altitude of 87 km and width of 8 km is never an unambiguous, good solution for any of the measurements. Even for a fixed width of ˜ 8.4 km, one can sometimes find several centre altitudes that yield equally good temperature agreement. Weighted temperatures measured by lidar are not suitable to unambiguously determine the emission height and width of an airglow layer. However, when actual altitude and width data are lacking, a comparison with lidars can provide an estimate of how representative a measured rotational temperature is of an assumed altitude and width. I found the rotational temperature to represent the temperature at the commonly assumed altitude of 87.4 km and width of 8.4 km to within ±16 K, on average. This is not a measurement uncertainty.

Ultraviolet-induced DNA excision repair in human B and T lymphocytes. II

International Nuclear Information System (INIS)

Yew, F.F.-H.; Johnson, R.T.

1979-01-01

Despite their great sensitivity to ultraviolet light purified human B and T lymphocytes are capable of complete repair provided that the ultraviolet dose does not exceed 0.5 Jm -2 . Their capacity to repair, as measured by the restoration of DNA supercoiling in preparations of nucleoids, and their survival are significantly increased in the presence of deoxyribonucleosides. Certain agents which inhibit semi-conservative DNA synthesis (hydroxyurea, 1-β-D-arabino-furanosylcytosine (arafCyt) either stop or delay the repair process in lymphocytes. The effect of hydroxyurea is eventually overcome spontaneously, but changes in the sedimentation behaviour of ultraviolet-irradiated nucleoids caused by arafCyt can only be neutralized by addition of deoxycytidine. The effective inhibition of repair by arafCyt permits the detection of extremely small amounts of ultraviolet damage and also the estimation of when repair is complete. (Auth.)

Near infrared and extreme ultraviolet light pulses induced modifications of ultrathin Co films

Directory of Open Access Journals (Sweden)

Jan Kisielewski

2017-05-01

Full Text Available We report on comparative study of magnetic properties of Pt/Co/Pt trilayers after irradiation with different light sources. Ultrathin Pt/Co/Pt films were deposited by molecular beam epitaxy technique on sapphire (0001 substrates. Pt buffers were grown at room temperature (RT and at 750°C (high temperature, HT. The samples were irradiated with a broad range of light energy densities (up to film ablation using two different single pulse irradiation sources: (i 40 fs laser with 800 nm wavelength and (ii 3 ns laser-plasma source of extreme ultraviolet (EUV with the most intense emission centered at 11 nm. The light pulse-driven irreversible structural and as a consequence, magnetic modifications were investigated using polar magneto-optical Kerr effect-based microscopy and atomic and magnetic force microscopies. The light pulse-induced transitions from the out-of-plane to in-plane magnetization state, and from in-plane to out-of-plane, were observed for both types of samples and irradiation methods. Diagrams of the magnetic states as a function of the Co layer thickness and energy density of the absorbed femtosecond pulses were constructed for the samples with both the RT and HT buffers. The energy density range responsible for the creation of the out-of-plane magnetization was wider for the HT than for RT buffer. This is correlated with the higher (for HT crystalline quality and much smoother Pt/Co surface deduced from the X-ray diffraction studies. Submicrometer magnetic domains were observed in the irradiated region while approaching the out-of-plane magnetization state. Changes of Pt/Co/Pt structures are discussed for both types of light pulses.

Thermal transport studies using extreme ultraviolet spectroscopy: Final technical report, 5 March 1986-30 June 1987

International Nuclear Information System (INIS)

Griem, H.R.

1987-12-01

Thermal transport was investigated in laser-produced plasmas using spectroscopic measurements in the extreme ultraviolet. Theoretical work in collaboration with the University of Rochester allowed comparisons to be made of experimental spectra to a lagrangian hydrodynamic code. Results showed that transport is influenced by thermal flux inhibition in addition to non-uniformities in the laser irradiation. This work is a continuation of last year's project in which the main thermal transport results are reported. Very rich spectra were obtained in these experiments which yielded additional information on the ablating plasmas. A doppler shift was observed for neonlike titanium lines relative to higher ionization states of Ti. This shift is attributed to differences in expansion velocities between different charge states of Ti. A detailed report discussing this effect is attached. New lines were identified for Ti XXI and Ti XIX from these spectra in the wavelength region from 12 to 15 /angstrom/. The new heliumlike lines of Ti can exhibit population inversion and are candidates for x-ray laser experiments. A preprint of this paper is attached. Finally, line ratios of Ti XIX and Ti XX were employed to determine electron densities and temperatures. A report is also attached discussing these results

Radiation damage resistance of AlGaN detectors for applications in the extreme-ultraviolet spectral range

Energy Technology Data Exchange (ETDEWEB)

Barkusky, Frank; Peth, Christian; Bayer, Armin; Mann, Klaus [Laser-Laboratorium-Goettingen e.V., Hans-Adolf-Krebs-Weg 1, D-37077 Goettingen (Germany); John, Joachim; Malinowski, Pawel E. [Interuniversity MicroElectronic Center (IMEC), Kapeldreef 75, B-3001 Leuven (Belgium)

2009-09-15

We report on the fabrication of aluminum gallium nitride (AlGaN) Schottky-photodiode-based detectors. AlGaN layers were grown using metal-organic chemical vapor deposition (MOCVD) on Si(111) wafers. The diodes were characterized at a wavelength of 13.5 nm using a table-top extreme-ultraviolet (EUV) radiation source, consisting of a laser-produced xenon plasma and a Schwarzschild objective. The responsivity of the diodes was tested between EUV energies ranging from 320 nJ down to several picojoules. For low fluences, a linear responsivity of 7.14 mAs/J could be determined. Saturation starts at approximately 1 nJ, merging into a linear response of 0.113 mAs/J, which could be attributed to the photoeffect on the Au electrodes on top of the diode. Furthermore, degradation tests were performed up to an absolute dose of 3.3x10{sup 19} photons/cm{sup 2}. AlGaN photodiodes were compared to commercially available silicon-based photodetectors. For AlGaN diodes, responsivity does not change even for the highest EUV dose, whereas the response of the Si diode decreases linearly to {approx}93% after 2x10{sup 19} photons/cm{sup 2}.

Simulations and observations of plasma depletion, ion composition, and airglow emissions in two auroral ionospheric depletion experiments

International Nuclear Information System (INIS)

Yau, A.W.; Whalen, B.A.; Harris, F.R.; Gattinger, R.L.; Pongratz, M.B.; Bernhardt, P.A.

1985-01-01

In an ionospheric depletion experiment where chemically reactive vapors such as H 2 O and CO 2 are injected into the O + dominant F region to accelerate the plasma recombination rate and to reduce the plasma density, the ion composition in the depleted region is modified, and photometric emissions are produced. We compare in situ ion composition, density, and photometric measurements from two ionospheric depletion experiments with predictions from chemical modeling. The two injections, Waterhole I and III, were part of an auroral perturbation experiment and occurred in different ambient conditions. In both injections a core region of greater than fivefold plasma depletion was observed over roughly-equal5-km diameter within seconds of the injection, surrounded by an outer region of less drastic and slower depletion. In Waterhole I the plasma density was depleted tenfold over a 30-km diamter region after 2 min. The ambient O + density was drastically reduced, and the molecular O + 2 abundance was enhanced fivehold in the depletion region. OH airglow emission associated with the depletion was observed with a peak emission intensity of roughly-equal1 kR. In Waterhole III the ambient density was a decade lower, and the plasma depletion was less drastic, being twofold over 30 km after 2 min. The airglow emissions were also much less intense and below measurement sensitivity (30 R for the OH 306.4-nm emission; 50 R for the 630.0-nm emission)

Dynamics of the polar mesopause and lower thermosphere region as observed in the night airglow emissions

International Nuclear Information System (INIS)

Myraboe, H.K.

1988-02-01

This work utilizes night airglow emissions to deduce temperatures, dynamics, energetics, transport and photochemistry of the polar 80-110 km atmospheric region. The morphological behaviour of the polar 80-110 km region as seen in the night airglow emissions is best described by quasi regular to regular variations in the temperature and in the intensities of the emissions with periods ranging from minutes to a few days. Temperature amplitudes are seen from a few degrees up to ±50 K. Intensity changes up to several hundred percent may occur. Gravity waves from below are generally found to be present in the region, being responsible for much of the short period variations. The long period variations are seen to be related to circulation changes in the lower atmosphere. Stratospheric warmings are generally associated by a cooling of the 80-110 km region by a ratio approximately twice as large in amplitude as the heating at the 10 mbar level. The semidiurnal tide is found to be dominant with a peak to peak amplitude of about 5 K, in contrast to model calculations. Effects from geomagnetic phenomena on the energetics and dynamics of the region are not seen and, if present, have to be small or rare as compared to the influence from below. There is a mesopause temperature maximum at winter solstice. Pronounced differences in the day to day and seasonal behaviour of the odd oxygen associated nightglows at the North and South Pole are found. This may indicate fundamental differences at the two poles in the winter mesopause region circulation and energetics

An Extreme-ultraviolet Wave Generating Upward Secondary Waves in a Streamer-like Solar Structure

Science.gov (United States)

Zheng, Ruisheng; Chen, Yao; Feng, Shiwei; Wang, Bing; Song, Hongqiang

2018-05-01

Extreme-ultraviolet (EUV) waves, spectacular horizontally propagating disturbances in the low solar corona, always trigger horizontal secondary waves (SWs) when they encounter the ambient coronal structure. We present the first example of upward SWs in a streamer-like structure after the passing of an EUV wave. This event occurred on 2017 June 1. The EUV wave happened during a typical solar eruption including a filament eruption, a coronal mass ejection (CME), and a C6.6 flare. The EUV wave was associated with quasi-periodic fast propagating (QFP) wave trains and a type II radio burst that represented the existence of a coronal shock. The EUV wave had a fast initial velocity of ∼1000 km s‑1, comparable to high speeds of the shock and the QFP wave trains. Intriguingly, upward SWs rose slowly (∼80 km s‑1) in the streamer-like structure after the sweeping of the EUV wave. The upward SWs seemed to originate from limb brightenings that were caused by the EUV wave. All of the results show that the EUV wave is a fast-mode magnetohydrodynamic (MHD) shock wave, likely triggered by the flare impulses. We suggest that part of the EUV wave was probably trapped in the closed magnetic fields of the streamer-like structure, and upward SWs possibly resulted from the release of slow-mode trapped waves. It is believed that the interplay of the strong compression of the coronal shock and the configuration of the streamer-like structure is crucial for the formation of upward SWs.

Photometric search for variable stars in the young open cluster Berkeley 59

Science.gov (United States)

Lata, Sneh; Pandey, A. K.; Maheswar, G.; Mondal, Soumen; Kumar, Brijesh

2011-12-01

We present the time series photometry of stars located in the extremely young open cluster Berkeley 59. Using the 1.04-m telescope at Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, we have identified 42 variables in a field of ˜13 × 13 arcmin2 around the cluster. The probable members of the cluster have been identified using a (V, V-I) colour-magnitude diagram and a (J-H, H-K) colour-colour diagram. 31 variables have been found to be pre-main-sequence stars associated with the cluster. The ages and masses of the pre-main-sequence stars have been derived from the colour-magnitude diagram by fitting theoretical models to the observed data points. The ages of the majority of the probable pre-main-sequence variable candidates range from 1 to 5 Myr. The masses of these pre-main-sequence variable stars have been found to be in the range of ˜0.3 to ˜3.5 M⊙, and these could be T Tauri stars. The present statistics reveal that about 90 per cent T Tauri stars have period dispersal of the discs of relatively massive stars.

Characteristics of Atmospheric Waves Observed From Airglow Measurements in the Northern High-Latitude

Directory of Open Access Journals (Sweden)

Young-In Won

2004-06-01

Full Text Available The terrestrial nightglow emission in near infrared region were obtained using a Fourier Transform Spectrometer (FTS at Esrange, Sweden (67.90°N, 21.10°E and the OH(4-2 bands were used to derive temperature and airglow emission rate of the upper mesosphere. For this study, we analyzed data taken during winter of 2001/2002 and performed spectral analysis to retrieve wave information. From the Lomb-Scargle spectral analysis to the measured temperatures, dominant oscillations at various periods near tidal frequency are found. Most commonly observed waves are 4, 6, and 8 hour oscillations. Because of periods and persistence, the observed oscillations are most likely of tidal origin, i.e. zonally symmetric tides which are known to have their maximum amplitudes at the pole.

Photoionization of resonantly driven atomic states by an extreme ultraviolet-free-electron laser: intensity dependence and renormalization of Rabi frequencies

International Nuclear Information System (INIS)

Kaiser, B; Brand, A; Glässl, M; Vagov, A; Axt, V M; Pietsch, U

2013-01-01

We analyze theoretically the high intensity photoionization dynamics of a system with two atomic states resonantly coupled by coherent extreme ultraviolet laser radiation that also gives rise to the ionization. The ground state occupation of such a system is shown to exhibit damped Rabi oscillations. The corresponding ionization, which is responsible for the damping, scales almost linearly with the field intensity when the pulse length exceeds the Rabi period. For shorter pulses a quadratic scaling is found. The Rabi frequency is shifted compared to its value for an isolated two-level system. The shift increases with excitation intensity and can acquire a high percentage of the unrenormalized frequency at high intensities. Analytical results obtained within a simplified solvable model demonstrate that the damping and the shift both result from the coupling of the discrete states to the ionization continuum and are therefore closely related. Numerical simulations for a two-electron system reveal at high intensities the importance of off-resonant ionization channels. (paper)

Application of Laser Plasma Sources of Soft X-rays and Extreme Ultraviolet (EUV) in Imaging, Processing Materials and Photoionization Studies

Science.gov (United States)

Fiedorowicz, H.; Bartnik, A.; Wachulak, P. W.; Jarocki, R.; Kostecki, J.; Szczurek, M.; Ahad, I. U.; Fok, T.; Szczurek, A.; Wȩgrzyński, Ł.

In the paper we present new applications of laser plasma sources of soft X-rays and extreme ultraviolet (EUV) in various areas of plasma physics, nanotechnology and biomedical engineering. The sources are based on a gas puff target irradiated with nanosecond laser pulses from commercial Nd: YAG lasers, generating pulses with time duration from 1 to 10 ns and energies from 0.5 to 10 J at a 10 Hz repetition rate. The targets are produced with the use of a double valve system equipped with a special nozzle to form a double-stream gas puff target which allows for high conversion efficiency of laser energy into soft X-rays and EUV without degradation of the nozzle. The sources are equipped with various optical systems to collect soft X-ray and EUV radiation and form the radiation beam. New applications of these sources in imaging, including EUV tomography and soft X-ray microscopy, processing of materials and photoionization studies are presented.

Nonlinear Dichroism in Back-to-Back Double Ionization of He by an Intense Elliptically Polarized Few-Cycle Extreme Ultraviolet Pulse.

Science.gov (United States)

Ngoko Djiokap, J M; Manakov, N L; Meremianin, A V; Hu, S X; Madsen, L B; Starace, Anthony F

2014-11-28

Control of double ionization of He by means of the polarization and carrier-envelope phase (CEP) of an intense, few-cycle extreme ultraviolet (XUV) pulse is demonstrated numerically by solving the six-dimensional two-electron, time-dependent Schrödinger equation for He interacting with an elliptically polarized XUV pulse. Guided by perturbation theory (PT), we predict the existence of a nonlinear dichroic effect (∝I^{3/2}) that is sensitive to the CEP, ellipticity, peak intensity I, and temporal duration of the pulse. This dichroic effect (i.e., the difference of the two-electron angular distributions for opposite helicities of the ionizing XUV pulse) originates from interference of first- and second-order PT amplitudes, allowing one to probe and control S- and D-wave channels of the two-electron continuum. We show that the back-to-back in-plane geometry with unequal energy sharing is an ideal one for observing this dichroic effect that occurs only for an elliptically polarized, few-cycle attosecond pulse.

A Radiation Homeland Security Workshop Presented to the City of Berkeley Fire Department

Science.gov (United States)

Matis, Howard

2005-04-01

A radiation incident in a community, ranging from a transportation accident to a dirty bomb, is expected to be rare, but still can occur. First responders to such an incident must be prepared. City of Berkeley officials met with members of the Lawrence Berkeley National Laboratory staff and agreed that the laboratory participants would create material and teach it to all of their fire fighting staff. To design such a course, nuclear physicists, biologists and health physicists merged some of their existing teaching material together with previous homeland security efforts to produce a course that lasted one full day. The material was designed to help alleviate the myths and fear of radiation experienced by many first responders. It included basic nuclear physics information, biological effects, and methods that health physicists use to detect and handle radiation. The curriculum included several hands on activities which involved working directly with the meters the Berkeley Fire Department possessed. In addition, I will discuss some observations from teaching this course material plus some unusual problems that we encountered, such as suddenly the whole class responding to a fire.

Nanoscale inhomogeneity and photoacid generation dynamics in extreme ultraviolet resist materials

Science.gov (United States)

Wu, Ping-Jui; Wang, Yu-Fu; Chen, Wei-Chi; Wang, Chien-Wei; Cheng, Joy; Chang, Vencent; Chang, Ching-Yu; Lin, John; Cheng, Yuan-Chung

2018-03-01

The development of extreme ultraviolet (EUV) lithography towards the 22 nm node and beyond depends critically on the availability of resist materials that meet stringent control requirements in resolution, line edge roughness, and sensitivity. However, the molecular mechanisms that govern the structure-function relationships in current EUV resist systems are not well understood. In particular, the nanoscale structures of the polymer base and the distributions of photoacid generators (PAGs) should play a critical roles in the performance of a resist system, yet currently available models for photochemical reactions in EUV resist systems are exclusively based on homogeneous bulk models that ignore molecular-level details of solid resist films. In this work, we investigate how microscopic molecular organizations in EUV resist affect photoacid generations in a bottom-up approach that describes structure-dependent electron-transfer dynamics in a solid film model. To this end, molecular dynamics simulations and stimulated annealing are used to obtain structures of a large simulation box containing poly(4-hydroxystyrene) (PHS) base polymers and triphenylsulfonium based PAGs. Our calculations reveal that ion-pair interactions govern the microscopic distributions of the polymer base and PAG molecules, resulting in a highly inhomogeneous system with nonuniform nanoscale chemical domains. Furthermore, the theoretical structures were used in combination of quantum chemical calculations and the Marcus theory to evaluate electron transfer rates between molecular sites, and then kinetic Monte Carlo simulations were carried out to model electron transfer dynamics with molecular structure details taken into consideration. As a result, the portion of thermalized electrons that are absorbed by the PAGs and the nanoscale spatial distribution of generated acids can be estimated. Our data reveal that the nanoscale inhomogeneous distributions of base polymers and PAGs strongly affect the

Quantification of isomerically summed hydrocarbon contributions to crude oil by carbon number, double bond equivalent, and aromaticity using gas chromatography with tunable vacuum ultraviolet ionization.

Science.gov (United States)

Nowak, Jeremy A; Weber, Robert J; Goldstein, Allen H

2018-03-12

The ability to structurally characterize and isomerically quantify crude oil hydrocarbons relevant to refined fuels such as motor oil, diesel, and gasoline represents an extreme challenge for chromatographic and mass spectrometric techniques. This work incorporates two-dimensional gas chromatography coupled to a tunable vacuum ultraviolet soft photoionization source, the Chemical Dynamics Beamline 9.0.2 of the Advanced Light Source at the Lawrence Berkeley National Laboratory, with a time-of-flight mass spectrometer (GC × GC-VUV-TOF) to directly characterize and isomerically sum the contributions of aromatic and aliphatic species to hydrocarbon classes of four crude oils. When the VUV beam is tuned to 10.5 ± 0.2 eV, both aromatic and aliphatic crude oil hydrocarbons are ionized to reveal the complete chemical abundance of C 9 -C 30 hydrocarbons. When the VUV beam is tuned to 9.0 ± 0.2 eV only aromatic hydrocarbons are ionized, allowing separation of the aliphatic and aromatic fractions of the crude oil hydrocarbon chemical classes in an efficient manner while maintaining isomeric quantification. This technique provides an effective tool to determine the isomerically summed aromatic and aliphatic hydrocarbon compositions of crude oil, providing information that goes beyond typical GC × GC separations of the most dominant hydrocarbon isomers.

Berkeley High-Resolution Ball

International Nuclear Information System (INIS)

Diamond, R.M.

1984-10-01

Criteria for a high-resolution γ-ray system are discussed. Desirable properties are high resolution, good response function, and moderate solid angle so as to achieve not only double- but triple-coincidences with good statistics. The Berkeley High-Resolution Ball involved the first use of bismuth germanate (BGO) for anti-Compton shield for Ge detectors. The resulting compact shield permitted rather close packing of 21 detectors around a target. In addition, a small central BGO ball gives the total γ-ray energy and multiplicity, as well as the angular pattern of the γ rays. The 21-detector array is nearly complete, and the central ball has been designed, but not yet constructed. First results taken with 9 detector modules are shown for the nucleus 156 Er. The complex decay scheme indicates a transition from collective rotation (prolate shape) to single- particle states (possibly oblate) near spin 30 h, and has other interesting features

A Community of Scientists and Educators: The Compass Project at UC Berkeley

Science.gov (United States)

Roth, Nathaniel; Schwab, Josiah

2016-01-01

The Berkeley Compass Project is a self-formed group of graduate and undergraduate students in the physical sciences at the University of California, Berkeley. Its goals are to improve undergraduate physics education, provide opportunities for professional development, and increase retention of students from populations underrepresented in the physical sciences. For undergraduate students, the core Compass experience consists of a summer program and several seminar courses. These programs are designed to foster a diverse, collaborative student community in which students engage in authentic research practices and regular self-reflection. Graduate students, together with upper-level undergraduates, design and run all Compass programs. Compass strives to incorporate best practices from the science education literature. Experiences in Compass leave participants poised to be successful students researchers, teachers, and mentors.

Lawrence Berkeley Laboratory 1994 site environmental report

International Nuclear Information System (INIS)

1995-05-01

The 1994 Site Environmental Report summarizes environmental activities at Lawrence Berkeley Laboratory (LBL) for the calendar year (CY) 1994. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the Laboratory's environmental management programs when measured against regulatory standards and DOE requirements. The report also discusses significant highlight and planning efforts of these programs. The format and content of the report are consistent with the requirements of the U.S. Department of Energy (DOE) Order 5400.1, General Environmental Protection Program

Lawrence Berkeley Laboratory 1994 site environmental report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-05-01

The 1994 Site Environmental Report summarizes environmental activities at Lawrence Berkeley Laboratory (LBL) for the calendar year (CY) 1994. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the Laboratory`s environmental management programs when measured against regulatory standards and DOE requirements. The report also discusses significant highlight and planning efforts of these programs. The format and content of the report are consistent with the requirements of the U.S. Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

The Advanced Light Source: A new tool for research in atomic and molecular physics

International Nuclear Information System (INIS)

Schlachter, F.; Robinson, A.

1991-04-01

The Advanced Light Source at the Lawrence Berkeley Laboratory will be the world's brightest synchrotron radiation source in the extreme ultraviolet and soft x-ray regions of the spectrum when it begins operation in 1993. It will be available as a national user facility to researchers in a broad range of disciplines, including materials science, atomic and molecular physics, chemistry, biology, imaging, and technology. The high brightness of the ALS will be particularly well suited to high-resolution studies of tenuous targets, such as excited atoms, ions, and clusters. 13 figs., 4 tabs

High brightness extreme ultraviolet (at 13.5 nm) emission from time-of-flight controlled discharges with coaxial fuel injection

International Nuclear Information System (INIS)

Hosokai, Tomonao; Horioka, Kazuhiko; Hotta, Eiki; Yokoyama, Takuma; Sato, Hiroto; Zhidkov, Alexei

2008-01-01

Extreme ultraviolet (EUV) emission from discharge produced plasma with the coaxial injection of fuel vapor (tin and lithium) produced by laser ablation is experimentally studied. Multiple plasma pinches preceding a strong and long recombination radiation of EUV are observed in the first half cycle of a sinusoidal discharge current. Due to the time-of-flight control type of the discharge, the shape of pinch radiation pulses is almost identical. With the coaxial injection of time-of-flight controlled discharges, the highest brightness of EUV emission (maximum extracted energy of 244.3 mJ/2π sr per pulse with the emitter size of ∼1x0.3 mm 2 in full width at half maximum) is provided with efficiency exceeding 2% of deposited energy into the plasma (or 1% of dissipated energy in the discharge) due to a much better matching with the optimal plasma parameters in the recombination regime and a decrease in the off-duty factor. Stability of emitting plasma of the repetitive pinches is essentially improved with use of a second laser pulse

Extreme Ultraviolet Process Optimization for Contact Layer of 14 nm Node Logic and 16 nm Half Pitch Memory Devices

Science.gov (United States)

Tseng, Shih-En; Chen, Alek

2012-06-01

Extreme ultraviolet (EUV) lithography is considered the most promising single exposure technology at the 27 nm half-pitch node and beyond. The imaging performance of ASML TWINSCAN NXE:3100 has been demonstrated to be able to resolve 26 nm Flash gate layer and 16 nm static random access memory (SRAM) metal layer with a 0.25 numerical aperture (NA) and conventional illumination. Targeting for high volume manufacturing, ASML TWINSCAN NXE:3300B, featuring a 0.33 NA lens with off-axis illumination, will generate a higher contrast aerial image due to improved diffraction order collection efficiency and is expected to reduce target dose via mask biasing. This work performed a simulation to determine how EUV high NA imaging benefits the mask rule check trade-offs required to achieve viable lithography solutions in two device application scenarios: a 14 nm node 6T-SRAM contact layer and a 16 nm half-pitch NAND Flash staggered contact layer. In each application, the three-dimensional mask effects versus Kirchhoff mask were also investigated.

Electron-hole pairs generated in ZrO2 nanoparticle resist upon exposure to extreme ultraviolet radiation

Science.gov (United States)

Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

2018-02-01

Metal oxide nanoparticle resists have attracted much attention as the next-generation resist used for the high-volume production of semiconductor devices. However, the sensitization mechanism of the metal oxide nanoparticle resists is unknown. Understanding the sensitization mechanism is important for the efficient development of resist materials. In this study, the energy deposition in a zirconium oxide (ZrO2) nanoparticle resist was investigated. The numbers of electron-hole pairs generated in a ZrO2 core and an methacrylic acid (MAA) ligand shell upon exposure to 1 mJ cm-2 (exposure dose) extreme ultraviolet (EUV) radiations were theoretically estimated to be 0.16 at most and 0.04-0.17 cm2 mJ-1, respectively. By comparing the calculated distribution of electron-hole pairs with the line-and-space patterns of the ZrO2 nanoparticle resist fabricated by an EUV exposure tool, the number of electron-hole pairs required for the solubility change of the resist films was estimated to be 1.3-2.2 per NP. NP denotes a nanoparticle consisting of a metal oxide core with a ligand shell. In the material design of metal oxide nanoparticle resists, it is important to efficiently use the electron-hole pairs generated in the metal oxide core for the chemical change of ligand molecules.

Guide to user facilities at the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

1984-04-01

Lawrence Berkeley Laboratories' user facilities are described. Specific facilities include: the National Center for Electron Microscopy; the Bevalac; the SuperHILAC; the Neutral Beam Engineering Test Facility; the National Tritium Labeling Facility; the 88 inch Cyclotron; the Heavy Charged-Particle Treatment Facility; the 2.5 MeV Van de Graaff; the Sky Simulator; the Center for Computational Seismology; and the Low Background Counting Facility

Spectroscopy of the extreme ultraviolet dayglow at 6.5A resolution - Atomic and ionic emissions between 530 and 1240A

Science.gov (United States)

Gentieu, E. P.; Feldman, P. D.; Meier, R. R.

1979-01-01

EUV spectra (530-1500A) of the day airglow in up, down and horizontal aspect orientations have been obtained with 6.5A resolution and a limiting sensitivity of 5R from a rocket experiment. Below 834A the spectrum is rich in previously unobserved OII transitions connecting with 4S(0), 2D(0), and 2P(0) states. Recent broad-band photometric observations of geocoronal HeI 584A emission in terms of the newly observed OII emissions are shown. The OI 989A and OI 1304A emissions exhibit similar dependence on altitude and viewing geometry with the OI 989A brightness 1/15 that of OI 1340. Emission at 1026A is identified as geocoronal HI Lyman beta rather than OI multiplet emission and observed intensities agree well with model estimates. An unexpectedly high NI 1200/NI 1134A brightness ratio is evidence of a significant contribution from photodissociative excitation of N2 to the NI 1200A source function.

Impurity study of TMX using ultraviolet spectroscopy

International Nuclear Information System (INIS)

Allen, S.L.; Strand, O.T.; Moos, H.W.; Fortner, R.J.; Nash, T.J.; Dietrich, D.D.

1981-01-01

An extreme ultraviolet (EUV) study of the emissions from intrinsic and injected impurities in TMX is presented. Two survey spectrographs were used to determine that the major impurities present were oxygen, nitrogen, carbon, and titanium. Three absolutely-calibrated monochromators were used to measure the time histories and radial profiles of these impurity emissions in the central cell and each plug. Two of these instruments were capable of obtaining radial profiles as a function of time in a single shot

O2/1 Delta/ emission in the day and night airglow of Venus

Science.gov (United States)

Connes, P.; Noxon, J. F.; Traub, W. A.; Carleton, N. P.

1979-01-01

An intense airglow from O2(1 Delta) at 1.27 microns on both the light and the dark sides of Venus has been detected by using a ground-based high-resolution Fourier-transform spectrometer. Both dayglow and nightglow are roughly 1,000 times brighter than the visible O2 nightglow found by Veneras 9 and 10 in 1975. The column emission rate of O2(1 Delta) from Venus is close to the rate at which fresh O atoms are produced from photolysis of CO2 on the day side. Formation of O2(1 Delta) is thus a major step in the removal of O atoms from the atmosphere, and dynamical processes must carry these atoms to the night side fast enough to yield a maximum density near 90 km, which is almost constant over the planet.

Simultaneous measurements of the OH(8,3) band and 015577A airglow emissions

International Nuclear Information System (INIS)

Takahashi, H.; Sahai, Y.; Clemesha, B.R.; Simonich, D.M.; Batista, P.P.; Teixeira, N.R.

1981-01-01

Simultaneous measurements of the night airglow OH(8,3) band and OI 5577A have been made at Cachoeira Paulista (22.7 0 S, 45,2 0 W) during June-August 1976. Correlations between the nocturnal variations of these emissions and also with the OH rotational temperature are presented. It is found that OH (8,3) is correlated with the rotational temperature but with a time lag of about 1 hour. The variations of 5577A lead the OH (8,3) by about 2 to 3 hours. The rotational temperature co-varies with 5577A, rather than OH (8,3) and there is no significant time lag. Based on the correlation study, the nocturnal variations of the two emissions can be explained by the atmospheric density perturbation caused by solar tides and internal gravity waves. (Author) [pt

Community Relations Plan for Lawrence Berkeley Laboratory. Environmental Restoration Program

Energy Technology Data Exchange (ETDEWEB)

1993-07-01

The Lawrence Berkeley Laboratory (LBL) has applied to the California Environmental Protection Agency, Department of Toxic Substances Control (DTSC), for renewal of its Hazardous Waste Handling Facility Permit. A permit is required under Resource Conservation and Recovery Act (RCRA) regulations. The permit will allow LBL to continue using its current hazardous waste handling facility, upgrade the existing facility, and construct a replacement facility. The new facility is scheduled for completion in 1995. The existing facility will be closed under RCRA guidelines by 1996. As part of the permitting process, LBL is required to investigate areas of soil and groundwater contamination at its main site in the Berkeley Hills. The investigations are being conducted by LBL`s Environmental Restoration Program and are overseen by a number of regulatory agencies. The regulatory agencies working with LBL include the California Environmental Protection Agency`s Department of Toxic Substances Control, the California Regional Water Quality Control Board, the Bay Area Air Quality Management District, the East Bay Municipal Utilities District, and the Berkeley Department of Environmental Health. RCRA requires that the public be informed of LBL`s investigations and site cleanup, and that opportunities be available for the public to participate in making decisions about how LBL will address contamination issues. LBL has prepared this Community Relations Plan (CRP) to describe activities that LBL will use to keep the community informed of environmental restoration progress and to provide for an open dialogue with the public on issues of importance. The CRP documents the community`s current concerns about LBL`s Environmental Restoration Program. Interviews conducted between February and April 1993 with elected officials, agency staff, environmental organizations, businesses, site neighbors, and LBL employees form the basis for the information contained in this document.

Filtering and polychromatic vision in mantis shrimps: themes in visible and ultraviolet vision.

Science.gov (United States)

Cronin, Thomas W; Bok, Michael J; Marshall, N Justin; Caldwell, Roy L

2014-01-01

Stomatopod crustaceans have the most complex and diverse assortment of retinal photoreceptors of any animals, with 16 functional classes. The receptor classes are subdivided into sets responsible for ultraviolet vision, spatial vision, colour vision and polarization vision. Many of these receptor classes are spectrally tuned by filtering pigments located in photoreceptors or overlying optical elements. At visible wavelengths, carotenoproteins or similar substances are packed into vesicles used either as serial, intrarhabdomal filters or lateral filters. A single retina may contain a diversity of these filtering pigments paired with specific photoreceptors, and the pigments used vary between and within species both taxonomically and ecologically. Ultraviolet-filtering pigments in the crystalline cones serve to tune ultraviolet vision in these animals as well, and some ultraviolet receptors themselves act as birefringent filters to enable circular polarization vision. Stomatopods have reached an evolutionary extreme in their use of filter mechanisms to tune photoreception to habitat and behaviour, allowing them to extend the spectral range of their vision both deeper into the ultraviolet and further into the red.

Lawrence Berkeley National Laboratory 1997 Site Environmental Report Vol. I

International Nuclear Information System (INIS)

Thorson, Patrick

1998-01-01

Each year, Ernest Orlando Lawrence Berkeley National Laboratory prepares an integrated report on its environmental programs to satisfy the requirements of U.S. Department of Energy Order 231.1. The Site Environmental Report for 1997 is intended to summarize Berkeley Lab's compliance with environmental standards and requirements, characterize environmental management efforts through surveillance and monitoring activities, and highlight significant programs and efforts for calendar year 1997. This report is structured into three basic areas that cover a general overview of the Laboratory, the status of environmental programs, and the results of the surveillance and monitoring activities, including air quality, surface water, groundwater, sanitary sewer, soil and sediment, vegetation and foodstuffs, radiation dose assessment, and quality assurance. The report is separated into two volumes. Volume I contains the body of the report, a list of references, a list of acronyms and abbreviations, a glossary, Appendix A (NESHAPS annual report), and Appendix B (distribution list for volume I). Volume II contains Appendix C, the individual data results from monitoring programs. Each chapter in volume I begins with an outline of the sections that follow

Sub-50-as isolated extreme ultraviolet continua generated by 1.6-cycle near-infrared pulse combined with double optical gating scheme

Science.gov (United States)

Oguri, Katsuya; Mashiko, Hiroki; Ogawa, Tatsuya; Hanada, Yasutaka; Nakano, Hidetoshi; Gotoh, Hideki

2018-04-01

We demonstrate the generation of ultrabroad bandwidth attosecond continua extending to sub-50-as duration in the extreme ultraviolet (EUV) region based on a 1.6-cycle Ti:sapphire laser pulse. The combination of the amplitude gating scheme with a sub-two-cycle driver pulse and the double optical gating scheme achieves the continuum generation with a bandwidth of 70 eV at the full width at half maximum near the peak photon energy of 140 eV, which supports a Fourier-transform-limited pulse duration as short as 32 as. The carrier-envelope-phase (CEP) dependence of the attosecond continua shows a single-peak structure originating from the half-cycle cut-off at appropriate CEP values, which strongly indicates the generation of a single burst of an isolated attosecond pulse. Our approach suggests a possibility for isolated sub-50-as pulse generation in the EUV region by compensating for the intrinsic attosecond chirp with a Zr filter.

Annual site environmental report of the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Schleimer, G.E.; Pauer, R.O.

1991-05-01

The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data for 1990 are presented, and general trends are discussed. The report is organized under the following topics: Environmental Program Overview; Environmental Permits; Environmental Assessments; Environmental Activities; Penetrating Radiation; Airborne Radionuclides; Waterborne Radionuclides; Public Doses Resulting from LBL Operations; Trends -- LBL Environmental Impact; Waterborne Pollutants; Airborne Pollutants; Groundwater Protection; and Quality Assurance. 20 refs., 26 figs., 23 tabs

Nuclear materials teaching and research at the University of California, Berkeley

International Nuclear Information System (INIS)

Olander, D.R.; Roberts, J.T.A.

1985-01-01

In academic nuclear engineering departments, research and teaching in the specialized subdiscipline of nuclear materials is usually a one-person or at best a two-person operation. These subcritical sizes invariably result in inadequate overall representation of the many topics in nuclear materials in the research program of the department, although broader coverage of the field is possible in course offerings. Even in course-work, the full range of materials problems important in nuclear technology cannot be dealt with in detail because the small number of faculty involved restricts staffing to as little as a single summary course and generally no more than three courses in this specialty. The contents of the two nuclear materials courses taught at the University of California at Berkeley are listed. Materials research in most US nuclear engineering departments focuses on irradiation effects on metals, but at UC Berkeley, the principal interest is in the high-temperature materials chemistry of UO 2 fuel and Zircaloy cladding

A community of scientists: cultivating scientific identity among undergraduates within the Berkeley Compass Project

Science.gov (United States)

Aceves, Ana V.; Berkeley Compass Project

2015-01-01

The Berkeley Compass Project is a self-formed group of graduate and undergraduate students in the physical sciences at UC Berkeley. Our goals are to improve undergraduate physics education, provide opportunities for professional development, and increase retention of students from populations typically underrepresented in the physical sciences. For students who enter as freshmen, the core Compass experience consists of a summer program and several seminar courses. These programs are designed to foster a diverse, collaborative student community in which students engage in authentic research practices and regular self-reflection. Compass encourages undergraduates to develop an identity as a scientist from the beginning of their university experience.

Laboratories for the 21st Century: Case Studies, Molecular Foundry, Berkeley, California

Energy Technology Data Exchange (ETDEWEB)

2010-11-01

This case study provides information on the Molecular Foundry, which incorporates Labs21 principles in its design and construction. The design includes many of the strategies researched at Lawrence Berkeley Laboratory for energy efficient cleanroom and data centers.

Popular Berkeley Lab X-ray Data Booklet reissued

International Nuclear Information System (INIS)

Robinson, Art

2001-01-01

X-ray scientists and synchrotron-radiation users who have been patiently waiting for an updated version of the popular X-Ray Data Booklet last published in 1986 by the Center for X-Ray Optics at the Lawrence Berkeley National Laboratory can breathe a sigh of relief. The venerable ''little orange book'' has now been reissued under the auspices of CXRO and the Advanced Light Source (ALS) with an April printing of 10,000 paper copies and the posting of a Web edition at http://xdb.lbl.gov

Temporal variations of electron density and temperature in Kr/Ne/H2 photoionized plasma induced by nanosecond pulses from extreme ultraviolet source

Science.gov (United States)

Saber, I.; Bartnik, A.; Wachulak, P.; Skrzeczanowski, W.; Jarocki, R.; Fiedorowicz, H.

2017-06-01

Spectral investigations of low-temperature photoionized plasmas created in a Kr/Ne/H2 gas mixture were performed. The low-temperature plasmas were generated by gas mixture irradiation using extreme ultraviolet pulses from a laser-plasma source. Emission spectra in the ultraviolet/visible range from the photoionized plasmas contained lines that mainly corresponded to neutral atoms and singly charged ions. Temporal variations in the plasma electron temperature and electron density were studied using different characteristic emission lines at various delay times. Results, based on Kr II lines, showed that the electron temperature decreased from 1.7 to 0.9 eV. The electron densities were estimated using different spectral lines at each delay time. In general, except for the Hβ line, in which the electron density decreased from 3.78 × 1016 cm-3 at 200 ns to 5.77 × 1015 cm-3 at 2000 ns, most of the electron density values measured from the different lines were of the order of 1015 cm-3 and decreased slightly while maintaining the same order when the delay time increased. The time dependences of the measured and simulated intensities of a spectral line of interest were also investigated. The validity of the partial or full local thermodynamic equilibrium (LTE) conditions in plasma was explained based on time-resolved electron density measurements. The partial LTE condition was satisfied for delay times in the 200 ns to 1500 ns range. The results are summarized, and the dominant basic atomic processes in the gas mixture photoionized plasma are discussed.

Excluded volume effects caused by high concentration addition of acid generators in chemically amplified resists used for extreme ultraviolet lithography

Science.gov (United States)

Kozawa, Takahiro; Watanabe, Kyoko; Matsuoka, Kyoko; Yamamoto, Hiroki; Komuro, Yoshitaka; Kawana, Daisuke; Yamazaki, Akiyoshi

2017-08-01

The resolution of lithography used for the high-volume production of semiconductor devices has been improved to meet the market demands for highly integrated circuits. With the reduction in feature size, the molecular size becomes non-negligible in the resist material design. In this study, the excluded volume effects caused by adding high-concentration acid generators were investigated for triphenylsulfonium nonaflate. The resist film density was measured by X-ray diffractometry. The dependences of absorption coefficient and protected unit concentration on acid generator weight ratio were calculated from the measured film density. Using these values, the effects on the decomposition yield of acid generators, the protected unit fluctuation, and the line edge roughness (LER) were evaluated by simulation on the basis of sensitization and reaction mechanisms of chemically amplified extreme ultraviolet resists. The positive effects of the increase in acid generator weight ratio on LER were predominant below the acid generator weight ratio of 0.3, while the negative effects became equivalent to the positive effects above the acid generator weight ratio of 0.3 owing to the excluded volume effects.

Contrasting behavior of covalent and molecular carbon allotropes exposed to extreme ultraviolet and soft x-ray free-electron laser radiation

Science.gov (United States)

Toufarová, M.; Hájková, V.; Chalupský, J.; Burian, T.; Vacík, J.; Vorlíček, V.; Vyšín, L.; Gaudin, J.; Medvedev, N.; Ziaja, B.; Nagasono, M.; Yabashi, M.; Sobierajski, R.; Krzywinski, J.; Sinn, H.; Störmer, M.; Koláček, K.; Tiedtke, K.; Toleikis, S.; Juha, L.

2017-12-01

All carbon materials, e.g., amorphous carbon (a-C) coatings and C60 fullerene thin films, play an important role in short-wavelength free-electron laser (FEL) research motivated by FEL optics development and prospective nanotechnology applications. Responses of a-C and C60 layers to the extreme ultraviolet (SPring-8 Compact SASE Source in Japan) and soft x-ray (free-electron laser in Hamburg) free-electron laser radiation are investigated by Raman spectroscopy, differential interference contrast, and atomic force microscopy. A remarkable difference in the behavior of covalent (a-C) and molecular (C60) carbonaceous solids is demonstrated under these irradiation conditions. Low thresholds for ablation of a fullerene crystal (estimated to be around 0.15 eV/atom for C60 vs 0.9 eV/atom for a-C in terms of the absorbed dose) are caused by a low cohesive energy of fullerene crystals. An efficient mechanism of the removal of intact C60 molecules from the irradiated crystal due to Coulomb repulsion of fullerene-cage cation radicals formed by the ionizing radiation is revealed by a detailed modeling.

THE ULTRAVIOLET BRIGHTEST TYPE Ia SUPERNOVA 2011de

International Nuclear Information System (INIS)

Brown, Peter J.

2014-01-01

We present and discuss the ultraviolet (UV)/optical photometric light curves and absolute magnitudes of the Type Ia supernova (SN Ia) 2011de from the Swift Ultraviolet/Optical Telescope. We find it to be the UV brightest SN Ia yet observed—more than a factor of 10 brighter than normal SNe Ia in the mid-ultraviolet. We find that the UV/optical brightness and broad light curve evolution can be modeled with additional flux from the shock of the ejecta hitting a relatively large red giant companion separated by 6 × 10 13 cm. However, the post-maximum behavior of other UV-bright SNe Ia can also be modeled in a similar manner, including objects with UV spectroscopy or pre-maximum photometry which is inconsistent with this model. This suggests that similar UV luminosities can be intrinsic or caused by other forms of shock interaction. The high velocities reported for SN 2011de make it distinct from the UV-bright ''super-Chandrasekhar'' SNe Ia and the NUV-blue group of normal SNe Ia. SN 2011de is an extreme example of the UV variations in SNe Ia

Ultraviolet Extensions

Science.gov (United States)

2008-01-01

[figure removed for brevity, see original site] Side-by-Side Comparison Click on image for larger view This ultraviolet image from NASA's Galaxy Evolution Explorer shows the Southern Pinwheel galaxy, also know as Messier 83 or M83. It is located 15 million light-years away in the southern constellation Hydra. Ultraviolet light traces young populations of stars; in this image, young stars can be seen way beyond the main spiral disk of M83 up to 140,000 light-years from its center. Could life exist around one of these far-flung stars? Scientists say it's unlikely because the outlying regions of a galaxy are lacking in the metals required for planets to form. The image was taken at scheduled intervals between March 15 and May 20, 2007. It is one of the longest-exposure, or deepest, images ever taken of a nearby galaxy in ultraviolet light. Near-ultraviolet light (or longer-wavelength ultraviolet light) is colored yellow, and far-ultraviolet light is blue. What Lies Beyond the Edge of a Galaxy The side-by-side comparison shows the Southern Pinwheel galaxy, or M83, as seen in ultraviolet light (right) and at both ultraviolet and radio wavelengths (left). While the radio data highlight the galaxy's long, octopus-like arms stretching far beyond its main spiral disk (red), the ultraviolet data reveal clusters of baby stars (blue) within the extended arms. The ultraviolet image was taken by NASA's Galaxy Evolution Explorer between March 15 and May 20, 2007, at scheduled intervals. Back in 2005, the telescope first photographed M83 over a shorter period of time. That picture was the first to reveal far-flung baby stars forming up to 63,000 light-years from the edge of the main spiral disk. This came as a surprise to astronomers because a galaxy's outer territory typically lacks high densities of star-forming materials. The newest picture of M83 from the Galaxy Evolution Explorer is shown at the right, and was taken over a longer period of time. In fact, it is one of the

Ernest Orlando Berkeley National Laboratory - Fundamental and applied research on lean premixed combustion

International Nuclear Information System (INIS)

Cheng, Robert K.

1999-01-01

Ernest Orland Lawrence Berkeley National Laboratory (Berkeley Lab) is the oldest of America's national laboratories and has been a leader in science and engineering technology for more than 65 years, serving as a powerful resource to meet Us national needs. As a multi-program Department of Energy laboratory, Berkeley Lab is dedicated to performing leading edge research in the biological, physical, materials, chemical, energy, environmental and computing sciences. Ernest Orlando Lawrence, the Lab's founder and the first of its nine Nobel prize winners, invented the cyclotron, which led to a Golden Age of particle physics and revolutionary discoveries about the nature of the universe. To this day, the Lab remains a world center for accelerator and detector innovation and design. The Lab is the birthplace of nuclear medicine and the cradle of invention for medical imaging. In the field of heart disease, Lab researchers were the first to isolate lipoproteins and the first to determine that the ratio of high density to low density lipoproteins is a strong indicator of heart disease risk. The demise of the dinosaurs--the revelation that they had been killed off by a massive comet or asteroid that had slammed into the Earth--was a theory developed here. The invention of the chemical laser, the unlocking of the secrets of photosynthesis--this is a short preview of the legacy of this Laboratory

Extreme ultraviolet fluorescence spectroscopy of pure and core-shell rare gas clusters at FLASH

Energy Technology Data Exchange (ETDEWEB)

Schroedter, Lasse

2013-08-15

The interaction of rare gas clusters with short-wavelength radiation of free-electron lasers (FELs) has been studied extensively over the last decade by means of electron and ion time-of-flight spectroscopy. This thesis describes the design and construction of a fluorescence spectrometer for the extreme ultraviolet (XUV) spectral range and discusses the cluster experiments performed at FLASH, the Free-electron LAser in Hamburg. Fluorescence of xenon and of argon clusters was studied, both in dependence on the FEL pulse intensity and on the cluster size. The FEL wavelength was set to the giant 4d-resonance of xenon at 13.5 nm and the FEL pulse intensity reached peak values of 2.7.10{sup 15} W/cm{sup 2}. For xenon clusters, charge states of at least 11+ were identified. For argon, charge states up to 7+ were detected. The cluster-size dependent study revealed a decrease of the fluorescence yield per atom with increasing cluster size. This decrease is explained with the help of a geometric model. It assumes that virtually the entire fluorescence yield stems from shells of ions on the cluster surface, whereas ions in the cluster core predominantly recombine non-radiatively with electrons. However, the detailed analysis of fluorescence spectra from clusters consisting of a core of Xe atoms and a surrounding shell of argon atoms shows that, in fact, a small fraction of the fluorescence signal comes from Xe ions in the cluster core. Interestingly, these ions are as highly charged as the ions in the shells of a pure Xe cluster. This result goes beyond the current understanding of charge and energy transfer processes in these systems and points toward the observation of ultrafast charging dynamics in a time window where mass spectrometry is inherently blind. (orig.)

Extreme ultraviolet fluorescence spectroscopy of pure and core-shell rare gas clusters at FLASH

International Nuclear Information System (INIS)

Schroedter, Lasse

2013-08-01

The interaction of rare gas clusters with short-wavelength radiation of free-electron lasers (FELs) has been studied extensively over the last decade by means of electron and ion time-of-flight spectroscopy. This thesis describes the design and construction of a fluorescence spectrometer for the extreme ultraviolet (XUV) spectral range and discusses the cluster experiments performed at FLASH, the Free-electron LAser in Hamburg. Fluorescence of xenon and of argon clusters was studied, both in dependence on the FEL pulse intensity and on the cluster size. The FEL wavelength was set to the giant 4d-resonance of xenon at 13.5 nm and the FEL pulse intensity reached peak values of 2.7.10 15 W/cm 2 . For xenon clusters, charge states of at least 11+ were identified. For argon, charge states up to 7+ were detected. The cluster-size dependent study revealed a decrease of the fluorescence yield per atom with increasing cluster size. This decrease is explained with the help of a geometric model. It assumes that virtually the entire fluorescence yield stems from shells of ions on the cluster surface, whereas ions in the cluster core predominantly recombine non-radiatively with electrons. However, the detailed analysis of fluorescence spectra from clusters consisting of a core of Xe atoms and a surrounding shell of argon atoms shows that, in fact, a small fraction of the fluorescence signal comes from Xe ions in the cluster core. Interestingly, these ions are as highly charged as the ions in the shells of a pure Xe cluster. This result goes beyond the current understanding of charge and energy transfer processes in these systems and points toward the observation of ultrafast charging dynamics in a time window where mass spectrometry is inherently blind. (orig.)

Biological effects of extreme environmental conditions. [considering limits of biosphere

Science.gov (United States)

Imshenetskiy, A. A.

1975-01-01

Actions of extreme physical and chemical space factors on microorganisms and plants are elaborated in order to establish limits for the biosphere. Considered are effects of low and high temperatures; ionizing and ultraviolet radiation; various gases; and effects of vibration, desiccation and acceleration.

The Advanced Light Source at Lawrence Berkeley Laboratory: a new tool for research in atomic physics

International Nuclear Information System (INIS)

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

1991-01-01

The Advanced Light Source, a third-generation national synchrotron-radiation facility now under construction at the Lawrence Berkeley Laboratory, is scheduled to begin serving qualified users across a broad spectrum of research areas in the spring of 1993. Based on a low-emittance electron storage ring optimized to operate at 1.5 GeV, the ALS will have 10 long straight sections available for insertion devices (undulators and wigglers) and 24 high-quality bend-magnet ports. The short pulse width (30-50 ps) will be ideal for time-resolved measurements. Undulators will generate high-brightness partially coherent soft X-ray and ultraviolet (XUV) radiation from below 10 eV to above 2 keV; this radiation is plane polarized. Wigglers and bend magnets will extend the spectrum by generating high fluxes of X-rays to photon energies above 10 keV. The ALS will have an extensive research program in which XUV radiation is used to study matter in allk its varied gaseous, liquid, and solid forms. The high brightness will open new areas of research in the materials sciences, such as spatially resolved spectroscopy (spectromicroscopy), and in biology, such as X-ray microscopy with element-specific sensitivity; the high flux will allow measurements in atomic physics and chemistry to be made with tenuous gas-phase targets. Technological applications could include lithography and nano-fabrication. (orig.)

Catalog of research projects at Lawrence Berkeley Laboratory, 1985

International Nuclear Information System (INIS)

1985-01-01

This Catalog has been created to aid in the transfer of technology from the Lawrence Berkeley Laboratory to potential users in industry, government, universities, and the public. The projects are listed for the following LBL groups: Accelerator and Fusion Research Division, Applied Science Division, Biology and Medicine Division, Center for Advanced Materials, Chemical Biodynamics Division, Computing Division, Earth Sciences Division, Engineering and Technical Services Division, Materials and Molecular Research Division, Nuclear Science Division, and Physics Division

Catalog of research projects at Lawrence Berkeley Laboratory, 1985

Energy Technology Data Exchange (ETDEWEB)

1985-01-01

This Catalog has been created to aid in the transfer of technology from the Lawrence Berkeley Laboratory to potential users in industry, government, universities, and the public. The projects are listed for the following LBL groups: Accelerator and Fusion Research Division, Applied Science Division, Biology and Medicine Division, Center for Advanced Materials, Chemical Biodynamics Division, Computing Division, Earth Sciences Division, Engineering and Technical Services Division, Materials and Molecular Research Division, Nuclear Science Division, and Physics Division.

Autonomous celestial navigation based on Earth ultraviolet radiance and fast gradient statistic feature extraction

Science.gov (United States)

Lu, Shan; Zhang, Hanmo

2016-01-01

To meet the requirement of autonomous orbit determination, this paper proposes a fast curve fitting method based on earth ultraviolet features to obtain accurate earth vector direction, in order to achieve the high precision autonomous navigation. Firstly, combining the stable characters of earth ultraviolet radiance and the use of transmission model software of atmospheric radiation, the paper simulates earth ultraviolet radiation model on different time and chooses the proper observation band. Then the fast improved edge extracting method combined Sobel operator and local binary pattern (LBP) is utilized, which can both eliminate noises efficiently and extract earth ultraviolet limb features accurately. And earth's centroid locations on simulated images are estimated via the least square fitting method using part of the limb edges. Taken advantage of the estimated earth vector direction and earth distance, Extended Kalman Filter (EKF) is applied to realize the autonomous navigation finally. Experiment results indicate the proposed method can achieve a sub-pixel earth centroid location estimation and extremely enhance autonomous celestial navigation precision.

Study on the resistance of haloferax radiotolerans, an extreme Halophilic archaebacterium from Uromia lake against ultraviolet (UV) light and 60Co gamma-rays

International Nuclear Information System (INIS)

Asgarni, E.; Shirzad, M.; Soudi, M. R.; Shahmohammadi, H. R.; Falsafi, T.

2006-01-01

In this work, the capacity of an extreme halophilic archaebacterium, isolated from Uromia lake, Haloferax radiotolerans to withstand the lethal effects of ultraviolet light (UV),and 60 Co r-rays has been studied. The resistibility of this organism against the DNA-damaging agents was evaluated by calculating of the survival fractions at different dose rates of W and 60 Co r-rays radiations and compared with those of Escherichia coli B/r (a radioresistant strain of E. coli). D 37 values for Haloferax radiotolerans and E. coli B/r were 23 1, and 9 J/m 2 , respectively, by exposure to the UV light. They were 645, and 99 Gy, respectively, by exposure to 60 Co r-rays. Against these agents, Haloferax radiotolerans shows much more resistance compare to that of E. coli B/r. This is categorized as the first report of resistibility in the member of Archaea

The Dual-channel Extreme Ultraviolet Continuum Experiment: Sounding Rocket EUV Observations of Local B Stars to Determine Their Potential for Supplying Intergalactic Ionizing Radiation

Science.gov (United States)

Erickson, Nicholas; Green, James C.; France, Kevin; Stocke, John T.; Nell, Nicholas

2018-06-01

We describe the scientific motivation and technical development of the Dual-channel Extreme Ultraviolet Continuum Experiment (DEUCE). DEUCE is a sounding rocket payload designed to obtain the first flux-calibrated spectra of two nearby B stars in the EUV 650-1150Å bandpass. This measurement will help in understanding the ionizing flux output of hot B stars, calibrating stellar models and commenting on the potential contribution of such stars to reionization. DEUCE consists of a grazing incidence Wolter II telescope, a normal incidence holographic grating, and the largest (8” x 8”) microchannel plate detector ever flown in space, covering the 650-1150Å band in medium and low resolution channels. DEUCE will launch on December 1, 2018 as NASA/CU sounding rocket mission 36.331 UG, observing Epsilon Canis Majoris, a B2 II star.

Solar ultraviolet hazards

International Nuclear Information System (INIS)

Azmah Ali

1995-01-01

The paper discussed the following subjects: the sources of ultraviolet radiation, solar ultraviolet radiation definition, effects of over exposure to solar ultraviolet radiation, exposure limits and radiation protection of this radiation

THE MUSCLES TREASURY SURVEY. II. INTRINSIC LY α AND EXTREME ULTRAVIOLET SPECTRA OF K AND M DWARFS WITH EXOPLANETS

Energy Technology Data Exchange (ETDEWEB)

Youngblood, Allison; France, Kevin; Loyd, R. O. Parke [Laboratory for Atmospheric and Space Physics, University of Colorado, 600 UCB, Boulder, CO 80309 (United States); Linsky, Jeffrey L. [JILA, University of Colorado and NIST, 440 UCB, Boulder, CO 80309 (United States); Redfield, Seth [Astronomy Department and Van Vleck Observatory, Wesleyan University, Middletown, CT 06459-0123 (United States); Schneider, P. Christian [European Space Research and Technology Centre (ESA/ESTEC), Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Wood, Brian E. [Naval Research Laboratory, Space Science Division, Washington, DC 20375 (United States); Brown, Alexander [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Froning, Cynthia [Dept. of Astronomy C1400, University of Texas, Austin, TX 78712 (United States); Miguel, Yamila [Laboratoire Lagrange, Universite de Nice-Sophia Antipolis, Observatoire de la Cote d’Azur, CNRS, Blvd de l’Observatoire, CS 34229, F-06304 Nice cedex 4 (France); Rugheimer, Sarah [Department of Earth and Environmental Sciences, Irvine Building, University of St. Andrews, St. Andrews KY16 9AL (United Kingdom); Walkowicz, Lucianne, E-mail: allison.youngblood@colorado.edu [The Adler Planetarium, 1300 S Lakeshore Dr, Chicago, IL 60605 (United States)

2016-06-20

The ultraviolet (UV) spectral energy distributions (SEDs) of low-mass (K- and M-type) stars play a critical role in the heating and chemistry of exoplanet atmospheres, but are not observationally well-constrained. Direct observations of the intrinsic flux of the Ly α line (the dominant source of UV photons from low-mass stars) are challenging, as interstellar H i absorbs the entire line core for even the closest stars. To address the existing gap in empirical constraints on the UV flux of K and M dwarfs, the MUSCLES Hubble Space Telescope Treasury Survey has obtained UV observations of 11 nearby M and K dwarfs hosting exoplanets. This paper presents the Ly α and extreme-UV spectral reconstructions for the MUSCLES targets. Most targets are optically inactive, but all exhibit significant UV activity. We use a Markov Chain Monte Carlo technique to correct the observed Ly α profiles for interstellar absorption, and we employ empirical relations to compute the extreme-UV SED from the intrinsic Ly α flux in ∼100 Å bins from 100–1170 Å. The reconstructed Ly α profiles have 300 km s{sup −1} broad cores, while >1% of the total intrinsic Ly α flux is measured in extended wings between 300 and 1200 km s{sup −1}. The Ly α surface flux positively correlates with the Mg ii surface flux and negatively correlates with the stellar rotation period. Stars with larger Ly α surface flux also tend to have larger surface flux in ions formed at higher temperatures, but these correlations remain statistically insignificant in our sample of 11 stars. We also present H i column density measurements for 10 new sightlines through the local interstellar medium.

Ultraviolet sterilization

International Nuclear Information System (INIS)

Schenck, G.O.

1987-01-01

Artificial ultraviolet radiation sources can supply bactericidal energy in such a high dosage that in less than a second a higher degree of disinfection is accomplished than by sun irradiation in hours. Bacteria, viruses, phages, and organic micropollutants can be degraded by photochemical wet combustion down to and below detection limits of organic carbon. There are no known ultraviolet-resistant microorganisms. There are limitations to ultraviolet treatment which can often be overcome by adequate technical measures. Unlike other water purification processes, ultraviolet irradiation only exterminates living organisms. The radiation must be able to penetrate to the objects of the kill; in a dose large enough to kill, and long enough to kill and prevent new growth. Contrary to filters, ultraviolet flow-through reactors do not restrict free flow significantly. In contrast to distillation, ultraviolet irradiation imposes no phase changes to the water. Used as a sequence in ultrapure water systems, maintenance requirements are virtually nonexistent; because of the absence of dissolved and particulate matter in purified water, mechanical cleaning of the photoreactor chambers is not essential. The process is highly economical; energy consumption is low and supervision minimal. 103 refs., 45 figs., 15 tabs

Lawrence Berkeley National Laboratory 1995 site environmental report

Energy Technology Data Exchange (ETDEWEB)

Balgobin, D.; Javandel, I.; Lackner, G.; Smith, C.; Thorson, P.; Tran, H.

1996-07-01

The 1995 Site Environmental Report summarizes environmental activities at the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) for the 1995 calendar year. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the environmental management programs. The report also discusses significant highlights and plans of these programs. Topics discussed include: environmental monitoring, environmental compliance programs, air quality, water quality, ground water protection, sanitary sewer monitoring, soil and sediment quality, vegetation and foodstuffs monitoring, and special studies which include preoperational monitoring of building 85 and 1995 sampling results, radiological dose assessment, and quality assessment.

Lawrence Berkeley National Laboratory 1995 site environmental report

International Nuclear Information System (INIS)

Balgobin, D.; Javandel, I.; Lackner, G.; Smith, C.; Thorson, P.; Tran, H.

1996-07-01

The 1995 Site Environmental Report summarizes environmental activities at the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) for the 1995 calendar year. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the environmental management programs. The report also discusses significant highlights and plans of these programs. Topics discussed include: environmental monitoring, environmental compliance programs, air quality, water quality, ground water protection, sanitary sewer monitoring, soil and sediment quality, vegetation and foodstuffs monitoring, and special studies which include preoperational monitoring of building 85 and 1995 sampling results, radiological dose assessment, and quality assessment

Lawrence Berkeley Laboratory upgrading approaches to existing facilities

International Nuclear Information System (INIS)

Engle, H.M. Jr.

1985-01-01

The Lawrence Berkeley Laboratory Plant Engineering Department instituted a seismic risk investigation and seismic upgrade program in 1970. This paper covers the upgrade of two buildings with dissimilar framing systems; Building No. 10, a World War II vintage heavy timber frame building, and Building No. 80, a steel frame structure constructed in 1954. The seismic upgrade task for both structures required that the buildings be kept in service during rehabilitation with a minimum of disruption to occupants. Rehabilitations were phased over two and three year periods with construction management and supervision performed by LBL Plant Engineering staff

Spitzer Infrared Spectrograph Observations of the Galactic Center: Quantifying the Extreme Ultraviolet/Soft X-ray Fluxes

Science.gov (United States)

Simpson, Janet P.

2018-04-01

It has long been shown that the extreme ultraviolet spectrum of the ionizing stars of H II regions can be estimated by comparing the observed line emission to detailed models. In the Galactic Center (GC), however, previous observations have shown that the ionizing spectral energy distribution (SED) of the local photon field is strange, producing both very low excitation ionized gas (indicative of ionization by late O stars) and also widespread diffuse emission from atoms too highly ionized to be found in normal H II regions. This paper describes the analysis of all GC spectra taken by Spitzer's Infrared Spectrograph and downloaded from the Spitzer Heritage Archive. In it, H II region densities and abundances are described, and serendipitously discovered candidate planetary nebulae, compact shocks, and candidate young stellar objects are tabulated. Models were computed with Cloudy, using SEDs from Starburst99 plus additional X-rays, and compared to the observed mid-infrared forbidden and recombination lines. The ages inferred from the model fits do not agree with recent proposed star formation sequences (star formation in the GC occurring along streams of gas with density enhancements caused by close encounters with the black hole, Sgr A*), with Sgr B1, Sgr C, and the Arches Cluster being all about the same age, around 4.5 Myr old, with similar X-ray requirements. The fits for the Quintuplet Cluster appear to give a younger age, but that could be caused by higher-energy photons from shocks from stellar winds or from a supernova.

Access to public drinking water fountains in Berkeley, California: a geospatial analysis.

Science.gov (United States)

Avery, Dylan C; Smith, Charlotte D

2018-01-24

In January 2015, Berkeley, California became the first city in the Unites States to impose a tax on sugar-sweetened beverages. The tax is intended to discourage purchase of sugary beverages and promote consumption of healthier alternatives such as tap water. The goal of the study was to assess the condition of public drinking water fountains and determine if there is a difference in access to clean, functioning fountains based on race or socio-economic status. A mobile-GIS App was created to locate and collect data on existing drinking water fountains in Berkeley, CA. Demographic variables related to race and socio-economic status (SES) were acquired from the US Census - American Community Survey database. Disparities in access to, or condition of drinking water fountains relative to demographics was explored using spatial analyses. Spatial statistical-analysis was performed to estimate demographic characteristics of communities near the water fountains and logistic regression was used to examine the relationship between household median income or race and condition of fountain. Although most fountains were classified as functioning, some were dirty, clogged, or both dirty and clogged. No spatial relationships between demographic characteristics and fountain conditions were observed. All geo-located data and a series of maps were provided to the City of Berkeley and the public. The geo-database created as an outcome of this study is useful for prioritizing maintenance of existing fountains and planning the locations of future fountains. The methodologies used for this study could be applied to a wide variety of asset inventory and assessment projects such as clinics or pharmaceutical dispensaries, both in developed and developing countries.

The Normal-incidence Vacuum-ultraviolet Spectrometer for the TJ-II and First Experimental Results

Energy Technology Data Exchange (ETDEWEB)

McCarthy, K.J.; Zurro, B.; Baciero, A.

2002-07-01

A normal-incidence spectrometer, operating in the extreme-ultraviolet and ultraviolet wavelength regions, has been commissioned for the TJ-II stellarator. The instrument has been custom built by McPherson, Chelmsford, MA, and has several unique features and accessories that are described here. The instrument and CCD detector has been tested and calibrated, and its performance evaluated, using spectral lines from glow discharges and a RF excited flow lamp. Finally, the first spectra collected with the instrument of TJ-II plasmas are presented and a preliminary estimation of an oxygen ion temperature is made. (Author) 23 refs.

The Normal-incidence Vacuum-ultraviolet Spectrometer for the TJ-II and First Experimental Results

International Nuclear Information System (INIS)

McCarthy, K. J.; Zurro, B.; Baciero, A.

2002-01-01

A normal-incidence spectrometer, operating in the extreme-ultraviolet and ultraviolet wavelength regions, has been commissioned for the TJ-II stellarator. The instrument has been custom built by McPherson, Chelmsford, MA, and has several unique features and accessories that are described here. The instrument and CCD detector has been tested and calibrated, and its performance evaluated, using spectral lines from glow discharges and a RF excited flow lamp. Finally, the first spectra collected with the instrument of TJ-II plasmas are presented and a preliminary estimation of an oxygen ion temperature is made. (Author) 23 refs

SPECTROSCOPIC OBSERVATIONS OF CONTINUOUS OUTFLOWS AND PROPAGATING WAVES FROM NOAA 10942 WITH EXTREME ULTRAVIOLET IMAGING SPECTROMETER/HINODE

International Nuclear Information System (INIS)

Nishizuka, N.; Hara, H.

2011-01-01

We focused on 'sit-and-stare' observations of an outflow region at the edge of active region NOAA 10942 on 2007 February 20 obtained by the Extreme ultraviolet Imaging Spectrometer on board Hinode. We analyzed the data above the base of the outflow and found both continuous outflows and waves, which propagate from the base of the outflow. The spectra at the base of the outflow and at higher locations show different properties. The line profiles show blue-side asymmetry at the base of the outflow where nonthermal broadening becomes large because of fast upflows generated by heating events. On the other hand, at higher locations line profiles are symmetric and the intensity disturbances vary in phase with the velocity disturbances. The correlations between the intensity and velocity disturbances become noticeable at higher locations, so this indicates evidence of (at least locally) upward propagating slow-mode waves along the outflow. We also found a transient oscillation of different period in the wavelet spectrum. This indicates that a different wave is additionally observed during a limited period. High cadence spectroscopic observations revealed intermittent signatures of nonthermal velocities. Each of them seems to correspond to the base of the propagating disturbances. Furthermore, a jet was captured by the sit-and-stare observations across the slit. The similarity of line profiles of the outflow and the jet may indicate that the flows and waves originate in unresolved explosive events in the lower atmosphere of the corona.

Higher Retail Prices of Sugar-Sweetened Beverages 3 Months After Implementation of an Excise Tax in Berkeley, California.

Science.gov (United States)

Falbe, Jennifer; Rojas, Nadia; Grummon, Anna H; Madsen, Kristine A

2015-11-01

We assessed the short-term ability to increase retail prices of the first US 1-cent-per-ounce excise tax on the distribution of sugar-sweetened beverages (SSBs), which was implemented in March 2015 by Berkeley, California. In 2014 and 2015, we examined pre- to posttax price changes of SSBs and non-SSBs in a variety of retailers in Berkeley and in the comparison cities Oakland and San Francisco, California. We examined price changes by beverage, brand, size, and retailer type. For smaller beverages (≤ 33.8 oz), price increases (cents/oz) in Berkeley relative to those in comparison cities were 0.69 (95% confidence interval [CI] = 0.36, 1.03) for soda, 0.47 (95% CI = 0.08, 0.87) for fruit-flavored beverages, and 0.47 (95% CI = 0.25, 0.69) for SSBs overall. For 2-liter bottles and multipacks of soda, relative price increases were 0.46 (95% CI = 0.03, 0.89) and 0.49 (95% CI = 0.21, 0.77). We observed no relative price increases for nontaxed beverages overall. Approximately 3 months after the tax was implemented, SSB retail prices increased more in Berkeley than in nearby cities, marking a step in the causal pathway between the tax and reduced SSB consumption.

Mesospheric front observations by the OH airglow imager carried out at Ferraz Station on King George Island, Antarctic Peninsula, in 2011

Science.gov (United States)

Giongo, Gabriel Augusto; Valentin Bageston, José; Prado Batista, Paulo; Wrasse, Cristiano Max; Dornelles Bittencourt, Gabriela; Paulino, Igo; Paes Leme, Neusa Maria; Fritts, David C.; Janches, Diego; Hocking, Wayne; Schuch, Nelson Jorge

2018-02-01

The main goals of this work are to characterize and investigate the potential wave sources of four mesospheric fronts identified in the hydroxyl near-infrared (OH-NIR) airglow images, obtained with an all-sky airglow imager installed at Comandante Ferraz Antarctic Station (EACF, as per its Portuguese acronym) located on King George Island in the Antarctic Peninsula. We identified and analyzed four mesospheric fronts in 2011 over King George Island. In addition, we investigate the atmospheric background environment between 80 and 100 km altitude and discuss the ducts and propagation conditions for these waves. For that, we used wind data obtained from a meteor radar operated at EACF and temperature data obtained from the TIMED/SABER satellite. The vertical wavenumber squared, m2, was calculated for each of the four waves. Even though no clearly defined duct (indicated by positive values of m2 sandwiched between layers above and below with m2 wind in the wave propagation direction (near to south) above the OH peak (88-92 km). The likely wave sources for these four cases were investigated by using meteorological satellite images and in two cases we could find that strong instabilities were potential sources, i.e., a cyclonic activity and a large convective cloud cell. In the other two cases it was not possible to associate troposphere sources as potential candidates for the generation of such wave fronts observed in the mesosphere and secondary wave sources were attributed to these cases.

Construction and operation of replacement hazardous waste handling facility at Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

1992-09-01

The US Department of Energy (DOE) has prepared an environmental assessment (EA), DOE/EA-0423, for the construction and operation of a replacement hazardous waste handling facility (HWHF) and decontamination of the existing HWHF at Lawrence Berkeley Laboratory (LBL), Berkeley, California. The proposed facility would replace several older buildings and cargo containers currently being used for waste handling activities and consolidate the LBL's existing waste handling activities in one location. The nature of the waste handling activities and the waste volume and characteristics would not change as a result of construction of the new facility. Based on the analysis in the EA, DOE has determined that the proposed action would not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969, 42 USC. 4321 et seq. Therefore, an environmental impact statement is not required

ASASSN-15LH: A SUPERLUMINOUS ULTRAVIOLET REBRIGHTENING OBSERVED BY SWIFT AND HUBBLE

Energy Technology Data Exchange (ETDEWEB)

Brown, Peter J.; Yang, Yi; Wang, Lifan [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A. and M. University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States); Cooke, Jeff; Mould, Jeremy [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn VIC 3122 (Australia); Olaes, Melanie; Quimby, Robert M. [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); Baade, Dietrich [European Organisation for Astronomical Research in the Southern Hemisphere (ESO), Karl-Schwarzschild-Str. 2, D-85748 Garching b. München (Germany); Gehrels, Neil [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hoeflich, Peter [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Maund, Justyn [Department of Physics and Astronomy F39 Hicks Building, Hounsfield Road Sheffield, S3 7RH (United Kingdom); Wheeler, J. Craig [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States)

2016-09-01

We present and discuss ultraviolet and optical photometry from the Ultraviolet/Optical Telescope, X-ray limits from the X-Ray Telescope on Swift, and imaging polarimetry and ultraviolet/optical spectroscopy with the Hubble Space Telescope , all from observations of ASASSN-15lh. It has been classified as a hydrogen-poor superluminous supernova (SLSN I), making it more luminous than any other supernova observed. ASASSN-15lh is not detected in the X-rays in individual or co-added observations. From the polarimetry we determine that the explosion was only mildly asymmetric. We find the flux of ASASSN-15lh to increase strongly into the ultraviolet, with an ultraviolet luminosity 100 times greater than the hydrogen-rich, ultraviolet-bright SLSN II SN 2008es. We find that objects as bright as ASASSN-15lh are easily detectable beyond redshifts of ∼4 with the single-visit depths planned for the Large Synoptic Survey Telescope. Deep near-infrared surveys could detect such objects past a redshift of ∼20, enabling a probe of the earliest star formation. A late rebrightening—most prominent at shorter wavelengths—is seen about two months after the peak brightness, which is itself as bright as an SLSN. The ultraviolet spectra during the rebrightening are dominated by the continuum without the broad absorption or emission lines seen in SLSNe or tidal disruption events (TDEs) and the early optical spectra of ASASSN-15lh. Our spectra show no strong hydrogen emission, showing only Ly α absorption near the redshift previously found by optical absorption lines of the presumed host. The properties of ASASSN-15lh are extreme when compared to either SLSNe or TDEs.

Ionization and dissociation dynamics of vinyl bromide probed by femtosecond extreme ultraviolet transient absorption spectroscopy

International Nuclear Information System (INIS)

Lin, Ming-Fu; Neumark, Daniel M.; Gessner, Oliver; Leone, Stephen R.

2014-01-01

Strong-field induced ionization and dissociation dynamics of vinyl bromide, CH 2 =CHBr, are probed using femtosecond extreme ultraviolet (XUV) transient absorption spectroscopy. Strong-field ionization is initiated with an intense femtosecond, near infrared (NIR, 775 nm) laser field. Femtosecond XUV pulses covering the photon energy range of 50-72 eV probe the subsequent dynamics by measuring the time-dependent spectroscopic features associated with transitions of the Br (3d) inner-shell electrons to vacancies in molecular and atomic valence orbitals. Spectral signatures are observed for the depletion of neutral C 2 H 3 Br, the formation of C 2 H 3 Br + ions in their ground (X ~ ) and first excited (A ~ ) states, the production of C 2 H 3 Br ++ ions, and the appearance of neutral Br ( 2 P 3/2 ) atoms by dissociative ionization. The formation of free Br ( 2 P 3/2 ) atoms occurs on a timescale of 330 ± 150 fs. The ionic A ~ state exhibits a time-dependent XUV absorption energy shift of ∼0.4 eV within the time window of the atomic Br formation. The yield of Br atoms correlates with the yield of parent ions in the A ~ state as a function of NIR peak intensity. The observations suggest that a fraction of vibrationally excited C 2 H 3 Br + (A ~ ) ions undergoes intramolecular vibrational energy redistribution followed by the C–Br bond dissociation. The C 2 H 3 Br + (X ~ ) products and the majority of the C 2 H 3 Br ++ ions are relatively stable due to a deeper potential well and a high dissociation barrier, respectively. The results offer powerful new insights about orbital-specific electronic processes in high field ionization, coupled vibrational relaxation and dissociation dynamics, and the correlation of valence hole-state location and dissociation in polyatomic molecules, all probed simultaneously by ultrafast table-top XUV spectroscopy

An extreme ultraviolet wave associated with a failed eruption observed by the Solar Dynamics Observatory

Science.gov (United States)

Zheng, R.; Jiang, Y.; Yang, J.; Bi, Y.; Hong, J.; Yang, B.; Yang, D.

2012-05-01

Aims: Taking advantage of the high temporal and spatial resolution of the Solar Dynamics Observatory (SDO) observations, we present an extreme ultraviolet (EUV) wave associated with a failed filament eruption that generated no coronal mass ejection (CME) on 2011 March 1. We aim at understanding the nature and origin of this EUV wave. Methods: Combining the high-quality observations in the photosphere, the chromosphere, and the corona, we studied the characteristics of the wave and its relations to the associated eruption. Results: The event occurred at an ephemeral region near a small active region. The continuous magnetic flux cancelation in the ephemeral region produced pre-eruption brightenings and two EUV jets, and excited the filament eruption, accompanying it with a microflare. After the eruption, the filament material appeared far from the eruption center, and the ambient loops seemed to be intact. It was evident that the filament eruption had failed and was not associated with a CME. The wave happened just after the north jet arrived, and apparently emanated ahead of the north jet, far from the eruption center. The wave propagated at nearly constant velocities in the range of 260-350 km s-1, with a slight negative acceleration in the last phase. Remarkably, the wave continued to propagate, and a loop in its passage was intact when wave and loop met. Conclusions: Our analysis confirms that the EUV wave is a true wave, which we interpret as a fast-mode wave. In addition, the close temporal and spatial relationship between the wave and the jet provides evidence that the wave was likely triggered by the jet when the CME failed to happen. Three movies are available in electronic form at http://www.aanda.org

Mask characterization for critical dimension uniformity budget breakdown in advanced extreme ultraviolet lithography

Science.gov (United States)

Nikolsky, Peter; Strolenberg, Chris; Nielsen, Rasmus; Nooitgedacht, Tjitte; Davydova, Natalia; Yang, Greg; Lee, Shawn; Park, Chang-Min; Kim, Insung; Yeo, Jeong-Ho

2013-04-01

As the International Technology Roadmap for Semiconductors critical dimension uniformity (CDU) specification shrinks, semiconductor companies need to maintain a high yield of good wafers per day and high performance (and hence market value) of finished products. This cannot be achieved without continuous analysis and improvement of on-product CDU as one of the main drivers for process control and optimization with better understanding of main contributors from the litho cluster: mask, process, metrology and scanner. We will demonstrate a study of mask CDU characterization and its impact on CDU Budget Breakdown (CDU BB) performed for advanced extreme ultraviolet (EUV) lithography with 1D (dense lines) and 2D (dense contacts) feature cases. We will show that this CDU contributor is one of the main differentiators between well-known ArFi and new EUV CDU budgeting principles. We found that reticle contribution to intrafield CDU should be characterized in a specific way: mask absorber thickness fingerprints play a role comparable with reticle CDU in the total reticle part of the CDU budget. Wafer CD fingerprints, introduced by this contributor, may or may not compensate variations of mask CDs and hence influence on total mask impact on intrafield CDU at the wafer level. This will be shown on 1D and 2D feature examples. Mask stack reflectivity variations should also be taken into account: these fingerprints have visible impact on intrafield CDs at the wafer level and should be considered as another contributor to the reticle part of EUV CDU budget. We also observed mask error enhancement factor (MEEF) through field fingerprints in the studied EUV cases. Variations of MEEF may play a role towards the total intrafield CDU and may need to be taken into account for EUV lithography. We characterized MEEF-through-field for the reviewed features, with results herein, but further analysis of this phenomenon is required. This comprehensive approach to quantifying the mask part of

Berkeley Foundation for Opportunities in Information Technology: A Decade of Broadening Participation

Science.gov (United States)

Crutchfield, Orpheus S. L.; Harrison, Christopher D.; Haas, Guy; Garcia, Daniel D.; Humphreys, Sheila M.; Lewis, Colleen M.; Khooshabeh, Peter

2011-01-01

The Berkeley Foundation for Opportunities in Information Technology is a decade-old endeavor to expose pre-college young women and underrepresented racial and ethnic minorities to the fields of computer science and engineering, and prepare them for rigorous, university-level study. We have served more than 150 students, and graduated more than 65…

"A Woman's World": The University of California, Berkeley, during the Second World War

Science.gov (United States)

Dorn, Charles

2008-01-01

During World War II, female students at the University of California, Berkeley--then the most populous undergraduate campus in American higher education--made significant advances in collegiate life. In growing numbers, women enrolled in male-dominated academic programs, including mathematics, chemistry, and engineering, as they prepared for…

Searching for multiple stellar populations in the massive, old open cluster Berkeley 39

Science.gov (United States)

Bragaglia, A.; Gratton, R. G.; Carretta, E.; D'Orazi, V.; Sneden, C.; Lucatello, S.

2012-12-01

The most massive star clusters include several generations of stars with a different chemical composition (mainly revealed by an Na-O anti-correlation) while low-mass star clusters appear to be chemically homogeneous. We are investigating the chemical composition of several clusters with masses of a few 104 M⊙ to establish the lower mass limit for the multiple stellar population phenomenon. Using VLT/FLAMES spectra we determine abundances of Fe, O, Na, and several other elements (α, Fe-peak, and neutron-capture elements) in the old open cluster Berkeley 39. This is a massive open cluster: M ~ 104 M⊙, approximately at the border between small globular clusters and large open clusters. Our sample size of about 30 stars is one of the largest studied for abundances in any open cluster to date, and will be useful to determine improved cluster parameters, such as age, distance, and reddening when coupled with precise, well-calibrated photometry. We find that Berkeley 39 is slightly metal-poor, ⟨[Fe/H]⟩ = -0.20, in agreement with previous studies of this cluster. More importantly, we do not detect any star-to-star variation in the abundances of Fe, O, and Na within quite stringent upper limits. The rms scatter is 0.04, 0.10, and 0.05 dex for Fe, O, and Na, respectively. This small spread can be entirely explained by the noise in the spectra and by uncertainties in the atmospheric parameters. We conclude that Berkeley 39 is a single-population cluster. Based on observations collected at ESO telescopes under programme 386.B-0009.Tables 2 and 3 are available in electronic form at http://www.aanda.org

Gilbert Newton Lewis: his influence on physical-organic chemists at Berkeley

Energy Technology Data Exchange (ETDEWEB)

Calvin, M.

1982-03-01

A review is presented of the historical contributions of Gilbert N. Lewis to science and a discussion of the influence of Lewis on the research of the members of the physical-organic staff at Berkeley, including Melvin Calvin, during the twenties, thirties and forties. Some specific examples are discussed. Also, the effect of Lewis, his science and administrative concepts in the creation of excellence in a department of chemistry are reviewed.

Gilbert Newton Lewis: his influence on physical-organic chemists at Berkeley

International Nuclear Information System (INIS)

Calvin, M.

1982-03-01

A review is presented of the historical contributions of Gilbert N. Lewis to science and a discussion of the influence of Lewis on the research of the members of the physical-organic staff at Berkeley, including Melvin Calvin, during the twenties, thirties and forties. Some specific examples are discussed. Also, the effect of Lewis, his science and administrative concepts in the creation of excellence in a department of chemistry are reviewed

Changes in prices, sales, consumer spending, and beverage consumption one year after a tax on sugar-sweetened beverages in Berkeley, California, US: A before-and-after study.

Directory of Open Access Journals (Sweden)

Lynn D Silver

2017-04-01

Full Text Available Taxes on sugar-sweetened beverages (SSBs meant to improve health and raise revenue are being adopted, yet evaluation is scarce. This study examines the association of the first penny per ounce SSB excise tax in the United States, in Berkeley, California, with beverage prices, sales, store revenue/consumer spending, and usual beverage intake.Methods included comparison of pre-taxation (before 1 January 2015 and first-year post-taxation (1 March 2015-29 February 2016 measures of (1 beverage prices at 26 Berkeley stores; (2 point-of-sale scanner data on 15.5 million checkouts for beverage prices, sales, and store revenue for two supermarket chains covering three Berkeley and six control non-Berkeley large supermarkets in adjacent cities; and (3 a representative telephone survey (17.4% cooperation rate of 957 adult Berkeley residents. Key hypotheses were that (1 the tax would be passed through to the prices of taxed beverages among the chain stores in which Berkeley implemented the tax in 2015; (2 sales of taxed beverages would decline, and sales of untaxed beverages would rise, in Berkeley stores more than in comparison non-Berkeley stores; (3 consumer spending per transaction (checkout episode would not increase in Berkeley stores; and (4 self-reported consumption of taxed beverages would decline. Main outcomes and measures included changes in inflation-adjusted prices (cents/ounce, beverage sales (ounces, consumers' spending measured as store revenue (inflation-adjusted dollars per transaction in two large chains, and usual beverage intake (grams/day and kilocalories/day. Tax pass-through (changes in the price after imposition of the tax for SSBs varied in degree and timing by store type and beverage type. Pass-through was complete in large chain supermarkets (+1.07¢/oz, p = 0.001 and small chain supermarkets and chain gas stations (1.31¢/oz, p = 0.004, partial in pharmacies (+0.45¢/oz, p = 0.03, and negative in independent corner stores and

Fun and games in Berkeley: the early years (1956-2013).

Science.gov (United States)

Tinoco, Ignacio

2014-01-01

Life at Berkeley for the past 57 years involved research on the thermodynamics, kinetics, and spectroscopic properties of RNA to better understand its structures, interactions, and functions. We (myself and all the graduate students and postdocs who shared in the fun) began with dinucleoside phosphates and slowly worked our way up to megadalton-sized RNA molecular motors. We used UV absorption, circular dichroism, circular intensity differential scattering, fluorescence, NMR, and single-molecule methods. We learned a lot and had fun doing it.

Particle production in high energy nucleus--nucleus experiments at Berkeley

International Nuclear Information System (INIS)

Schroeder, L.S.

1976-09-01

A review of high energy nucleus-nucleus experiments performed at the Berkeley Bevalac is presented. Earlier results on projectile and target fragmentation and pion production are briefly summarized. More recent results on Coulomb effects in projectile fragmentation, heavy ion total cross-sections, γ-ray production, and charged particle multiplicities are presented. Also, recent experiments which may shed light on phenomena arising from the central collision of two energetic nuclei, including recent evidence for and against the observation of nuclear shock waves, are reviewed

Non-Gaussian Velocity Distributions in Solar Flares from Extreme Ultraviolet Lines: A Possible Diagnostic of Ion Acceleration

International Nuclear Information System (INIS)

Jeffrey, Natasha L. S.; Fletcher, Lyndsay; Labrosse, Nicolas

2017-01-01

In a solar flare, a large fraction of the magnetic energy released is converted rapidly to the kinetic energy of non-thermal particles and bulk plasma motion. This will likely result in non-equilibrium particle distributions and turbulent plasma conditions. We investigate this by analyzing the profiles of high temperature extreme ultraviolet emission lines from a major flare (SOL2014-03-29T17:44) observed by the EUV Imaging Spectrometer (EIS) on Hinode . We find that in many locations the line profiles are non-Gaussian, consistent with a kappa distribution of emitting ions with properties that vary in space and time. At the flare footpoints, close to sites of hard X-ray emission from non-thermal electrons, the κ index for the Fe xvi 262.976 Å line at 3 MK takes values of 3–5. In the corona, close to a low-energy HXR source, the Fe xxiii 263.760 Å line at 15 MK shows κ values of typically 4–7. The observed trends in the κ parameter show that we are most likely detecting the properties of the ion population rather than any instrumental effects. We calculate that a non-thermal ion population could exist if locally accelerated on timescales ≤0.1 s. However, observations of net redshifts in the lines also imply the presence of plasma downflows, which could lead to bulk turbulence, with increased non-Gaussianity in cooler regions. Both interpretations have important implications for theories of solar flare particle acceleration.

Berkeley 51 Kümesinin Temel ve Astrofiziksel Parametrelerinin Belirlenmesi

Directory of Open Access Journals (Sweden)

İnci Akkaya Oralhan

2016-10-01

Full Text Available Galaksimizin birinci çeyreğinde bulunan ve daha önce çok az çalışılmış açık yıldız kümelerinden biri olan Berkeley 51 kümesinin temel astrofiziksel ve yapısal parametreleri CCD UBV(RIC ve 2MASS JHKS verileri kullanılarak elde edilmiştir. Kümeye ait CCD UBV(RIC verileri Meksika’da bulunan San Pedro Martir Ulusal Gözlemevi’nden 84cm’lik teleskop ile alınmıştır. Küme üyeliklerinin belirlenmesinde ise PPMXL kataloğundaki öz hareket verileri kullanılmıştır. Buna küre bu küme için elde edilen limit yarıçap Rlim=2.5 yay dakikası, kızarma E(B-V=0.85±0.05 kadir, E(J-H=0.28±0.02 kadir, uzaklık modülü DM=(m-M0=10.66±0.04 pc, uzaklığı d=1355±27 pc ve logaritmik yaş log(A=9.54±0.03 Myıl olarak bulunmuştur. Küme için ilk kez bulunan metal ve ağır element bolluğu ise sırasıyla [Fe/H]=-0.38 ve Z=0.006 olarak elde edilmiştir.Anahtar kelimeler: Açık yıldız kümeleri-Berkeley 51

Clinical results of stereotactic hellium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Levy, R.P.; Fabrikant, J.I.; Lyman, J.T.; Frankel, K.A.; Phillips, M.H.; Lawrence, J.H.; Tobias, C.A.

1989-12-01

The first therapeutic clinical trial using accelerated heavy-charged particles in humans was performed at Lawrence Berkeley Laboratory (LBL) for the treatment of various endocrine and metabolic disorders of the pituitary gland, and as suppressive therapy for adenohypophyseal hormone-responsive carcinomas and diabetic retinopathy. In acromegaly, Cushing's disease, Nelson's syndrome and prolactin-secreting tumors, the therapeutic goal in the 433 patients treated has been to destroy or inhibit the growth of the pituitary tumor and control hormonal hypersecretion, while preserving a functional rim of tissue with normal hormone-secreting capacity, and minimizing neurologic injury. An additional group of 34 patients was treated for nonsecreting chromophobe adenomas. This paper discusses the methods and results of stereotactic helium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory. 11 refs

Clinical results of stereotactic hellium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

Levy, R.P.; Fabrikant, J.I.; Lyman, J.T.; Frankel, K.A.; Phillips, M.H.; Lawrence, J.H.; Tobias, C.A.

1989-12-01

The first therapeutic clinical trial using accelerated heavy-charged particles in humans was performed at Lawrence Berkeley Laboratory (LBL) for the treatment of various endocrine and metabolic disorders of the pituitary gland, and as suppressive therapy for adenohypophyseal hormone-responsive carcinomas and diabetic retinopathy. In acromegaly, Cushing's disease, Nelson's syndrome and prolactin-secreting tumors, the therapeutic goal in the 433 patients treated has been to destroy or inhibit the growth of the pituitary tumor and control hormonal hypersecretion, while preserving a functional rim of tissue with normal hormone-secreting capacity, and minimizing neurologic injury. An additional group of 34 patients was treated for nonsecreting chromophobe adenomas. This paper discusses the methods and results of stereotactic helium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory. 11 refs.

Annual environmental monitoring report of the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Schleimer, G.E.

1989-06-01

The Environmental Monitoring Program of the Lawrence Berkeley Laboratory (LBL) is described. Data for 1988 are presented and general trends are discussed. In order to establish whether LBL research activities produced any impact on the population surrounding the laboratory, a program of environmental air and water sampling and continuous radiation monitoring was carried on throughout the year. For 1988, as in the previous several years, dose equivalents attributable to LBL radiological operations were a small fraction of both the relevant radiation protection guidelines (RPG) and of the natural radiation background. 16 refs., 7 figs., 21 tabs

Assembly Manual for the Berkeley Lab Cosmic Ray Detector

International Nuclear Information System (INIS)

Collier, Michael

2002-01-01

The Berkeley Lab Cosmic Ray Detector consists of 3 main components that must be prepared separately before they can be assembled. These components are the scintillator, circuit board, and casing. They are described in the main sections of this report, which may be completed in any order. Preparing the scintillator paddles involves several steps--cutting the scintillator material to the appropriate size and shape, preparing and attaching Lucite cookies (optional), polishing the edges, gluing the end to the photomultiplier tube (optional), and wrapping the scintillator. Since the detector has 2 paddles, each of the sections needs to be repeated for the other paddle

Annual environmental monitoring report of the Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

Schleimer, G.E. (ed.)

1989-06-01

The Environmental Monitoring Program of the Lawrence Berkeley Laboratory (LBL) is described. Data for 1988 are presented and general trends are discussed. In order to establish whether LBL research activities produced any impact on the population surrounding the laboratory, a program of environmental air and water sampling and continuous radiation monitoring was carried on throughout the year. For 1988, as in the previous several years, dose equivalents attributable to LBL radiological operations were a small fraction of both the relevant radiation protection guidelines (RPG) and of the natural radiation background. 16 refs., 7 figs., 21 tabs.

Development of a thinned back-illuminated CMOS active pixel sensor for extreme ultraviolet spectroscopy and imaging in space science

International Nuclear Information System (INIS)

Waltham, N.R.; Prydderch, M.; Mapson-Menard, H.; Pool, P.; Harris, A.

2007-01-01

We describe our programme to develop a large-format, science-grade, monolithic CMOS active pixel sensor for future space science missions, and in particular an extreme ultraviolet (EUV) spectrograph for solar physics studies on ESA's Solar Orbiter. Our route to EUV sensitivity relies on adapting the back-thinning and rear-illumination techniques first developed for CCD sensors. Our first large-format sensor consists of 4kx3k 5 μm pixels fabricated on a 0.25 μm CMOS imager process. Wafer samples of these sensors have been thinned by e2v technologies with the aim of obtaining good sensitivity at EUV wavelengths. We present results from both front- and back-illuminated versions of this sensor. We also present our plans to develop a new sensor of 2kx2k 10 μm pixels, which will be fabricated on a 0.35 μm CMOS process. In progress towards this goal, we have designed a test-structure consisting of six arrays of 512x512 10 μm pixels. Each of the arrays has been given a different pixel design to allow verification of our models, and our progress towards optimizing a design for minimal system readout noise and maximum dynamic range. These sensors will also be back-thinned for characterization at EUV wavelengths

Environmental Justice Screening Method (EJSM) Score, San Joaquin Valley CA, 2013, Occidental College and UC Berkeley

Data.gov (United States)

U.S. Environmental Protection Agency — The Cumulative Impacts (CI) screening method is jointly being developed by Manuel Pastor, Jim Sadd (Occidental College), and Rachel Morello-Frosch (UC Berkeley) ....

The design and implementation of Berkeley Lab's linuxcheckpoint/restart

Energy Technology Data Exchange (ETDEWEB)

Duell, Jason

2005-04-30

This paper describes Berkeley Linux Checkpoint/Restart (BLCR), a linux kernel module that allows system-level checkpoints on a variety of Linux systems. BLCR can be used either as a stand alone system for checkpointing applications on a single machine, or as a component by a scheduling system or parallel communication library for checkpointing and restoring parallel jobs running on multiple machines. Integration with Message Passing Interface (MPI) and other parallel systems is described.

Changes in prices, sales, consumer spending, and beverage consumption one year after a tax on sugar-sweetened beverages in Berkeley, California, US: A before-and-after study.

Science.gov (United States)

Silver, Lynn D; Ng, Shu Wen; Ryan-Ibarra, Suzanne; Taillie, Lindsey Smith; Induni, Marta; Miles, Donna R; Poti, Jennifer M; Popkin, Barry M

2017-04-01

Taxes on sugar-sweetened beverages (SSBs) meant to improve health and raise revenue are being adopted, yet evaluation is scarce. This study examines the association of the first penny per ounce SSB excise tax in the United States, in Berkeley, California, with beverage prices, sales, store revenue/consumer spending, and usual beverage intake. Methods included comparison of pre-taxation (before 1 January 2015) and first-year post-taxation (1 March 2015-29 February 2016) measures of (1) beverage prices at 26 Berkeley stores; (2) point-of-sale scanner data on 15.5 million checkouts for beverage prices, sales, and store revenue for two supermarket chains covering three Berkeley and six control non-Berkeley large supermarkets in adjacent cities; and (3) a representative telephone survey (17.4% cooperation rate) of 957 adult Berkeley residents. Key hypotheses were that (1) the tax would be passed through to the prices of taxed beverages among the chain stores in which Berkeley implemented the tax in 2015; (2) sales of taxed beverages would decline, and sales of untaxed beverages would rise, in Berkeley stores more than in comparison non-Berkeley stores; (3) consumer spending per transaction (checkout episode) would not increase in Berkeley stores; and (4) self-reported consumption of taxed beverages would decline. Main outcomes and measures included changes in inflation-adjusted prices (cents/ounce), beverage sales (ounces), consumers' spending measured as store revenue (inflation-adjusted dollars per transaction) in two large chains, and usual beverage intake (grams/day and kilocalories/day). Tax pass-through (changes in the price after imposition of the tax) for SSBs varied in degree and timing by store type and beverage type. Pass-through was complete in large chain supermarkets (+1.07¢/oz, p = 0.001) and small chain supermarkets and chain gas stations (1.31¢/oz, p = 0.004), partial in pharmacies (+0.45¢/oz, p = 0.03), and negative in independent corner stores and

The principle of phase stability and the accelerator program at Berkeley, 1945--1954

International Nuclear Information System (INIS)

Lofgren, E.J.

1994-07-01

The discovery of the Principle of Phase Stability by Vladimir Veksler and Edwin McMillian and the end of the war released a surge of accelerator activity at the Lawrence Berkeley Laboratory (then The University of California Radiation Laboratory). Six accelerators incorporating the Principle of Phase Stability were built in the period 1945--1954

Preparations for decommissioning the TRIGA Mark III Berkeley Research Reactor

International Nuclear Information System (INIS)

Denton, Michael M.; Lim, Tek. H.

1988-01-01

On December 20, 1986 the chancellor of UC Berkeley announced his decision to decommission the 20 year old Berkeley Research Reactor citing as principal reasons a decline in use and a need to erect a new computer science building over the reactor's site. In order to meet the University's construction timetable for the new building, the reactor staff together with other units of the campus administration have initiated a program to remove the reactor structure and clear the room for unlicensed use as expediently as possible. Due to the sequence of events which must occur in a limited amount of time, the University adopted a policy to contract out as much of the work as possible, including generation of the defueling and decommissioning plans.The first physical step in the decommissioning project is the removal of the irradiated fuel. This task is largely contracted out to a commercial firm with experience in the transport of radioactive materials and reactor fuel. As suggested by the NRC, the reactor will be defueled under the current operating license. This requires that all fuel must be off-site before the DP can be approved. Therefore any delay in defueling in-turn delays the decommissioning. The NRC has given no commitment or date for completion of their review. Informal discussion with NRC project managers and the experience from other facilities indicate that the review process will take between six and nine months

Young Cluster Berkeley 59: Properties, Evolution, and Star Formation

Science.gov (United States)

Panwar, Neelam; Pandey, A. K.; Samal, Manash R.; Battinelli, Paolo; Ogura, K.; Ojha, D. K.; Chen, W. P.; Singh, H. P.

2018-01-01

Berkeley 59 is a nearby (∼1 kpc) young cluster associated with the Sh2-171 H II region. We present deep optical observations of the central ∼2.5 × 2.5 pc2 area of the cluster, obtained with the 3.58 m Telescopio Nazionale Galileo. The V/(V–I) color–magnitude diagram manifests a clear pre-main-sequence (PMS) population down to ∼0.2 M ⊙. Using the near-infrared and optical colors of the low-mass PMS members, we derive a global extinction of A V = 4 mag and a mean age of ∼1.8 Myr, respectively, for the cluster. We constructed the initial mass function and found that its global slopes in the mass ranges of 0.2–28 M ⊙ and 0.2–1.5 M ⊙ are ‑1.33 and ‑1.23, respectively, in good agreement with the Salpeter value in the solar neighborhood. We looked for the radial variation of the mass function and found that the slope is flatter in the inner region than in the outer region, indicating mass segregation. The dynamical status of the cluster suggests that the mass segregation is likely primordial. The age distribution of the PMS sources reveals that the younger sources appear to concentrate close to the inner region compared to the outer region of the cluster, a phenomenon possibly linked to the time evolution of star-forming clouds. Within the observed area, we derive a total mass of ∼103 M ⊙ for the cluster. Comparing the properties of Berkeley 59 with other young clusters, we suggest it resembles more closely the Trapezium cluster.

Berkeley Lab's Saul Perlmutter wins E.O. Lawrence Award; scientist's work on supernovae reveals accelerating Universe

CERN Multimedia

2002-01-01

Saul Perlmutter, from Lawrence Berkeley National Laboratory Physics Division and leader of the Supernova Cosmology Project based there, has won the DOE's 2002 E.O. Lawrence Award in the physics category (2 pages).

Dilepton (e+e-) production recent pp and pd studies with DLS at Berkeley

International Nuclear Information System (INIS)

Schroeder, L.S.

1991-09-01

The use of dileptons as probes of hot, dense hadronic matter is described. Preliminary results on dileptons produced in p-p and p-d interactions at the Bevalac are presented along with potential ramifications for existing model calculations of dileptons at these energies. Future directions of the dilepton program at Berkeley are outlined. 14 refs., 3 figs

A Partnership between English Language Learners and a Team of Rocket Scientists: EPO for the NASA SDO Extreme Ultraviolet Variability Experiment (EVE)

Science.gov (United States)

Buhr, S. M.; McCaffrey, M. S.; Eparvier, F.; Murillo, M.

2008-05-01

Recent immigrant high school students were successfully engaged in learning about Sun-Earth connections through a partnership with the NASA Solar Dynamics Observatory Extreme Ultraviolet Variability Experiment (EVE) project. The students were enrolled in a pilot course as part of the Math, Engineering and Science Achievement (MESA) program. The English Language Learner (ELL) students doubled their achievement on a pre- and post- assessment on the content of the course. Students learned scientific content and vocabulary in English with support in Spanish, attended field trips, hosted scientist speakers, built antenna and deployed space weather monitors as part of the Stanford SOLAR project, and gave final presentations in English, showcasing their new computer skills. Teachers who taught the students in other courses noted gains in the students' willingness to use English in class and noted gains in math skills. The course has been broken into modules for use in shorter after-school environments, or for use by EVE scientists who are outside of the Boulder area. Video footage of "The Making of a Satellite", and "All About EVE" is completed for use in the kits. Other EVE EPO includes upcoming professional development for teachers and content workshops for journalists.

Planckian charged black holes in ultraviolet self-complete quantum gravity

Science.gov (United States)

Nicolini, Piero

2018-03-01

We present an analysis of the role of the charge within the self-complete quantum gravity paradigm. By studying the classicalization of generic ultraviolet improved charged black hole solutions around the Planck scale, we showed that the charge introduces important differences with respect to the neutral case. First, there exists a family of black hole parameters fulfilling the particle-black hole condition. Second, there is no extremal particle-black hole solution but quasi extremal charged particle-black holes at the best. We showed that the Hawking emission disrupts the condition of particle-black hole. By analyzing the Schwinger pair production mechanism, the charge is quickly shed and the particle-black hole condition can ultimately be restored in a cooling down phase towards a zero temperature configuration, provided non-classical effects are taken into account.

Ultraviolet Light Curves of Gaia16apd in Superluminous Supernova Models

Energy Technology Data Exchange (ETDEWEB)

Tolstov, Alexey; Zhiglo, Andrey; Nomoto, Ken’ichi; Blinnikov, Sergei [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Sorokina, Elena [Sternberg Astronomical Institute, M.V.Lomonosov Moscow State University, 119234 Moscow (Russian Federation); Kozyreva, Alexandra, E-mail: alexey.tolstov@ipmu.jp [The Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)

2017-08-10

Observations of Gaia16apd revealed extremely luminous ultraviolet emission among superluminous supernovae (SLSNe). Using radiation hydrodynamics simulations, we perform a comparison of UV light curves, color temperatures, and photospheric velocities between the most popular SLSN models: pair-instability supernova, magnetar, and interaction with circumstellar medium. We find that the interaction model is the most promising to explain the extreme UV luminosity of Gaia16apd. The differences in late-time UV emission and in color evolution found between the models can be used to link an observed SLSN event to the most appropriate model. Observations at UV wavelengths can be used to clarify the nature of SLSNe and more attention should be paid to them in future follow-up observations.

Driving Extreme Efficiency to Market

Science.gov (United States)

Garbesi, Karina

2014-03-01

The rapid development of extremely energy efficient appliances and equipment is essential to curtail catastrophic climate disruption. This will require the on-going development of products that apply all best-practices and that take advantage of the synergies of hybridization and building integration. Beyond that, it requires the development of new disruptive technologies and concepts. To facilitate these goals, in 2011 the Lawrence Berkeley National Laboratory and the U.S. Department of Energy launched the Max Tech and Beyond Design Competition for Ultra-Low-Energy-Use Appliances and Equipment. Now in its third year, the competition supports faculty-lead student design teams at U.S. universities to develop and test new technology prototypes. This talk describes what the competition and the Max Tech Program are doing to drive such rapid technology progress and to facilitate the entry to the market of successful Max Tech prototypes. The talk also initiates a discussion of physicists' unique role in driving that technology progress faster and farther. Emerging Technologies, Building Technologies Office, U.S. Department of Energy.

Catalog of Research Abstracts, 1993: Partnership opportunities at Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

1993-09-01

The 1993 edition of Lawrence Berkeley Laboratory`s Catalog of Research Abstracts is a comprehensive listing of ongoing research projects in LBL`s ten research divisions. Lawrence Berkeley Laboratory (LBL) is a major multi-program national laboratory managed by the University of California for the US Department of Energy (DOE). LBL has more than 3000 employees, including over 1000 scientists and engineers. With an annual budget of approximately $250 million, LBL conducts a wide range of research activities, many that address the long-term needs of American industry and have the potential for a positive impact on US competitiveness. LBL actively seeks to share its expertise with the private sector to increase US competitiveness in world markets. LBL has transferable expertise in conservation and renewable energy, environmental remediation, materials sciences, computing sciences, and biotechnology, which includes fundamental genetic research and nuclear medicine. This catalog gives an excellent overview of LBL`s expertise, and is a good resource for those seeking partnerships with national laboratories. Such partnerships allow private enterprise access to the exceptional scientific and engineering capabilities of the federal laboratory systems. Such arrangements also leverage the research and development resources of the private partner. Most importantly, they are a means of accessing the cutting-edge technologies and innovations being discovered every day in our federal laboratories.

Extreme ultraviolet (EUV) solar spectral irradiance (SSI) for ionospheric application - history and contemporary state-of-art

Science.gov (United States)

Schmidtke, G.; Jacobi, Ch.; Nikutowski, B.; Erhardt, Ch.

2014-11-01

After a historical survey of space related EUV measurements in Germany and the role of Karl Rawer in pursuing this work, we describe present developments in EUV spectroscopy and provide a brief outlook on future activities. The group of Karl Rawer has performed the first scientific space project in Western Europe on 19th October 1954. Then it was decided to include the field of solar EUV spectroscopy in ionospheric investigations. Starting in 1957 an intensified development of instrumentation was going on to explore solar EUV radiation, atmospheric airglow and auroral emissions until the institute had to stop space activities in the early nineteen-eighties. EUV spectroscopy was continued outside of the institute during eight years. This area of work was supported again by the institute developing the Auto-Calibrating Spectrometers (SolACES) for a mission on the International Space Station (ISS). After more than six years in space the instrument is still in operation. Meanwhile the work on the primary task also to validate EUV data available from other space missions has made good progress. The first results of validating those data and combine them into one set of EUV solar spectral irradiance are very promising. It will be recommended for using it by the science and application community. Moreover, a new low-cost type of an EUV spectrometer is presented for monitoring the solar EUV radiation. It shall be further developed for providing EUV-TEC data to be applied in ionospheric models replacing the Covington index F10.7. Applying these data for example in the GNSS signal evaluation a more accurate determination of GNSS receiver positions is expected for correcting the propagation delays of navigation signals traveling through the ionosphere from space to earth. - Latest results in the field of solar EUV spectroscopy are discussed, too.

Environmental assessment for the proposed construction and operation of a Genome Sequencing Facility in Building 64 at Lawrence Berkeley Laboratory, Berkeley, California

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-04-01

This document is an Environmental Assessment (EA) for a proposed project to modify 14,900 square feet of an existing building (Building 64) at Lawrence Berkeley Laboratory (LBL) to operate as a Genome Sequencing Facility. This EA addresses the potential environmental impacts from the proposed modifications to Building 64 and operation of the Genome Sequencing Facility. The proposed action is to modify Building 64 to provide space and equipment allowing LBL to demonstrate that the Directed DNA Sequencing Strategy can be scaled up from the current level of 750,000 base pairs per year to a facility that produces over 6,000,000 base pairs per year, while still retaining its efficiency.

Progress report on the Berkeley/Anglo-Australian Observatory high-redshift supernova search

International Nuclear Information System (INIS)

Goldhaber, G.; Perlmutter, S.; Pennypacker, C.; Marvin, H.; Muller, R.A.; Couch, W.; Boyle, B.

1990-11-01

There are two main efforts related to supernovae in progress at Berkeley. The first is an automated supernova search for nearby supernovae, which was already discussed by Carl Pennypacker at this conference. The second is a search for distant supernovae, in the z = 0.3 to 0.5 region, aimed at measuring Ω. It is the latter that I want to discuss in this paper. 3 refs., 18 figs

Construction and operation of replacement hazardous waste handling facility at Lawrence Berkeley Laboratory. Environmental Assessment

Energy Technology Data Exchange (ETDEWEB)

1992-09-01

The US Department of Energy (DOE) has prepared an environmental assessment (EA), DOE/EA-0423, for the construction and operation of a replacement hazardous waste handling facility (HWHF) and decontamination of the existing HWHF at Lawrence Berkeley Laboratory (LBL), Berkeley, California. The proposed facility would replace several older buildings and cargo containers currently being used for waste handling activities and consolidate the LBL`s existing waste handling activities in one location. The nature of the waste handling activities and the waste volume and characteristics would not change as a result of construction of the new facility. Based on the analysis in the EA, DOE has determined that the proposed action would not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969, 42 USC. 4321 et seq. Therefore, an environmental impact statement is not required.

Lawrence Berkeley laboratory neutral-beam engineering test facility power-supply system

International Nuclear Information System (INIS)

Lutz, I.C.; Arthur, C.A.; deVries, G.J.; Owren, H.M.

1981-10-01

The Lawrence Berkeley Laboratory is upgrading the neutral beam source test facility (NBSTF) into a neutral beam engineering test facility (NBETF) with increased capabilities for the development of neutral beam systems. The NBETF will have an accel power supply capable of 170 kV, 70 A, 30 sec pulse length, 10% duty cycle; and the auxiliary power supplies required for the sources. This paper describes the major components, their ratings and capabilities, and the flexibility designed to accomodate the needs of source development

Probing of Hermean Exosphere by ultraviolet spectroscopy: Instrument presentation, calibration philosophy and first lights results

Science.gov (United States)

Mariscal, J. F.; Rouanet, N.; Maria, J. L.; Quémerais, E.; Mine, P. O.; Zuppella, P.; Suman, M.; Nicolosi, P.; Pelizzo, M. G.; Yoshikawa, I.; Yoshioka, K.; Murakami, G.

2017-11-01

PHEBUS (Probing of Hermean Exosphere by Ultraviolet Spectroscopy) is a double spectrometer for the Extreme Ultraviolet range (55-155 nm) and the Far Ultraviolet range (145-315 nm) dedicated to the characterization of Mercury's exosphere composition and dynamics, and surface-exosphere connections. PHEBUS is part of the ESA BepiColombo cornerstone mission payload devoted to the study of Mercury. The BepiColombo mission consists of two spacecrafts: the Mercury Magnetospheric Orbiter (MMO) and the Mercury Planetary Orbiter (MPO) on which PHEBUS will be mounted. PHEBUS is a French-led instrument implemented in a cooperative scheme involving Japan (detectors), Russia (scanner) and Italy (ground calibration). Before launch, PHEBUS team want to perform a full absolute calibration on ground, in addition to calibrations which will be made in-flight, in order to know the instrument's response as precisely as possible. Instrument overview and calibration philosophy are introduced along with the first lights results observed by a first prototype.

Fermilab and Berkeley Lab Collaborate with Meyer Tool on Key Component for European Particle Accelerator

CERN Multimedia

2004-01-01

Officials of the U.S. Department of Energy's Fermi National Accelerator Laboratory and Lawrence Berkeley National Laboratory announced yesterday the completion of a key component of the U.S. contribution to the Large Hadron Collider, a particle accelerator under construction at CERN, in Geneva, Switzerland

Installation and experimental uses of RTNS-I at the University of California, Berkeley

International Nuclear Information System (INIS)

Belian, A.P.; Morse, E.C.; Tobin, M.

1996-01-01

The National Ignition Facility (NIF) features optical components with line-of-sight access to the 14 MeV neutrons generated by fusion reactions in the target. Two of these components are a final focusing lens, made of fused silica, and a frequency conversion crystal comprised of two potassium dihydrogen phosphate (KDP) crystals. The Rotating Target Neutron Source (RTNS-I), which was previously operated at Lawrence Livermore National Laboratory (LLNL), has now been re-installed at UC Berkeley and is being used for the studies of neutron irradiation of fused silica and KDP. The machine has been installed so as to re-utilize the concrete structure that once housed the Berkeley Research Reactor, now decommissioned. The RTNS uses a 2 - 5 mA beam of deuterons impinging upon a spinning internally cooled tritiated copper target with a 110 Ci tritium inventory. Maximum beam energy is 399 KeV. The 14 MeV neutron production rate is 1.0x10 12 n/sec. Some new features of the machine include fiber-optic coupled microprocessor control of accelerator parameters, a cryogenic tritium collection system, and a scrubber system for exhaust tritium management. 15 refs., 4 figs

Control system for the 2nd generation Berkeley automounters (BAM2) at GM/CA-CAT macromolecular crystallography beamlines

Energy Technology Data Exchange (ETDEWEB)

Makarov, O., E-mail: makarov@anl.gov [GM/CA-CAT, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Hilgart, M.; Ogata, C.; Pothineni, S. [GM/CA-CAT, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Cork, C. [Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2011-09-01

GM/CA-CAT at Sector 23 of the Advanced Photon Source (APS) is an NIH funded facility for crystallographic structure determination of biological macromolecules by X-ray diffraction. A second-generation Berkeley automounter is being integrated into the beamline control system at the 23BM experimental station. This new device replaces the previous all-pneumatic gripper motions with a combination of pneumatics and XYZ motorized linear stages. The latter adds a higher degree of flexibility to the robot including auto-alignment capability, accommodation of a larger capacity sample Dewar of arbitrary shape, and support for advanced operations such as crystal washing, while preserving the overall simplicity and efficiency of the Berkeley automounter design.

Particle excitation, airglow and H2 vibrational disequilibrium in the atmosphere of Jupiter

International Nuclear Information System (INIS)

Shemansky, D.E.

1984-09-01

The extreme ultraviolet EUV emission produced by particle excitation of the hydrogen atmospheres of Jupiter and Saturn is examined using model calculations to determine the nature of the energy deposition process and the effect of such processes on atmospheric structure. Tasks ranging from examination of phenomenologically related processes on Saturn and Titan to analysis of experimental laboratory data required to allow accurate modeling of emissions from hydrogenic atmospheres are investigated. An explanation of the hydrogen H Ly(alpha) bulge in Jupiter's emission from the equatorial region is presented. It is proposed that Saturn, rather than Titan is the major source of the extended hydrogen cloud. The atomic hydrogen detected at the rings of Saturn may originate predominantly from the same source. A cross calibration is obtained between the Pioneer 10 EUV photometer and the Voyager EUV spectrometers, thus providing a direct measure of the temporal morphology of Jupiter between a minimum and a maximum in solar activity. Atomic and molecular data required for the research program are analyzed. An extrapolation of conditions in the upper atmospheres of Jupiter and Saturn produces a predicted condition at Uranus in terms of excitation and hydrogen escape rates that may be observed at Voyager-Uranus encounter

At-wavelength interferometry of high-NA diffraction-limited EUV optics

International Nuclear Information System (INIS)

Goldberg, Kenneth A.; Naulleau, Patrick; Rekawa, Senajith; Denham, Paul; Liddle, J. Alexander; Anderson, Erik; Jackson, Keith; Bokor, Jeffrey; Attwood, David

2003-01-01

Recent advances in all-reflective diffraction-limited optical systems designed for extreme ultraviolet (EUV) lithography have pushed numerical aperture (NA) values from 0.1 to 0.3, providing Rayleigh resolutions of 27-nm. Worldwide, several high-NA EUV optics are being deployed to serve in the development of advanced lithographic techniques required for EUV lithography, including the creation and testing of new, high-resolution photoresists. One such system is installed on an undulator beamline at Lawrence Berkeley National Laboratory's Advanced Light Source. Sub(angstrom)-accuracy optical testing and alignment techniques, developed for use with the previous generations of EUV lithographic optical systems, are being extended for use at high NA. Considerations for interferometer design and use are discussed

Configuration interaction in charge exchange spectra of tin and xenon

Science.gov (United States)

D'Arcy, R.; Morris, O.; Ohashi, H.; Suda, S.; Tanuma, H.; Fujioka, S.; Nishimura, H.; Nishihara, K.; Suzuki, C.; Kato, T.; Koike, F.; O'Sullivan, G.

2011-06-01

Charge-state-specific extreme ultraviolet spectra from both tin ions and xenon ions have been recorded at Tokyo Metropolitan University. The electron cyclotron resonance source spectra were produced from charge exchange collisions between the ions and rare gas target atoms. To identify unknown spectral lines of tin and xenon, atomic structure calculations were performed for Sn14+-Sn17+ and Xe16+-Xe20+ using the Hartree-Fock configuration interaction code of Cowan (1981 The Theory of Atomic Structure and Spectra (Berkeley, CA: University of California Press)). The energies of the capture states involved in the single-electron process that occurs in these slow collisions were estimated using the classical over-barrier model.

Berkeley Lab's Saul Perlmutter wins E.O. Lawrence Award scientist's work on supernovae reveals accelerating universe

CERN Multimedia

2002-01-01

"Saul Perlmutter, a member of Lawrence Berkeley National Laboratory's Physics Division and leader of the international Supernova Cosmology Project based there, has won the Department of Energy's 2002 E.O. Lawrence Award in the physics category" (1/2 page).

Planckian charged black holes in ultraviolet self-complete quantum gravity

Directory of Open Access Journals (Sweden)

Piero Nicolini

2018-03-01

Full Text Available We present an analysis of the role of the charge within the self-complete quantum gravity paradigm. By studying the classicalization of generic ultraviolet improved charged black hole solutions around the Planck scale, we showed that the charge introduces important differences with respect to the neutral case. First, there exists a family of black hole parameters fulfilling the particle-black hole condition. Second, there is no extremal particle-black hole solution but quasi extremal charged particle-black holes at the best. We showed that the Hawking emission disrupts the condition of particle-black hole. By analyzing the Schwinger pair production mechanism, the charge is quickly shed and the particle-black hole condition can ultimately be restored in a cooling down phase towards a zero temperature configuration, provided non-classical effects are taken into account.

Effects of ultraviolet light on Hymenolepis diminuta ova and cysticercoids

International Nuclear Information System (INIS)

McGavock, W.D.; Howard, K.E.

1980-01-01

The ova and cysticercoids of Hymenolepis diminuta were exposed to a 2537 A wave length of ultraviolet light for various time periods. Development was extremely impaired in the cysts which had been irradiated for 30 and 60 minutes. When these were administered to the final host no tapeworms developed. From 113 intermediate host beetle larvae fed with irradiated ova, only three cysticercoids were recovered. Development was impaired in both cases and the infective rate of irradiated ova and cysts of the least exposed groups was lower than that of the controls

Lawrence Berkeley Laboratory Affirmative Action Program. Revised

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-06-01

The Lawrence Berkeley Laboratory`s Affirmative Action Program (AAP) serves as a working document that describes current policies, practices, and results in the area of affirmative action. It represents the Laboratory`s framework for an affirmative approach to increasing the representation of people of color and women in segments of our work force where they have been underrepresented and taking action to increase the employment of persons with disabilities and special disabled and Vietnam era veterans. The AAP describes the hierarchy of responsibility for Laboratory affirmative action, the mechanisms that exist for full Laboratory participation in the AAP, the policies and procedures governing recruitment at all levels, the Laboratory`s plan for monitoring, reporting, and evaluating affirmative action progress, and a description of special affirmative action programs and plans the Laboratory has used and will use in its efforts to increase the representation and retention of groups historically underrepresented in our work force.

Changes in prices, sales, consumer spending, and beverage consumption one year after a tax on sugar-sweetened beverages in Berkeley, California, US: A before-and-after study

Science.gov (United States)

Ryan-Ibarra, Suzanne; Taillie, Lindsey Smith; Induni, Marta

2017-01-01

Background Taxes on sugar-sweetened beverages (SSBs) meant to improve health and raise revenue are being adopted, yet evaluation is scarce. This study examines the association of the first penny per ounce SSB excise tax in the United States, in Berkeley, California, with beverage prices, sales, store revenue/consumer spending, and usual beverage intake. Methods and findings Methods included comparison of pre-taxation (before 1 January 2015) and first-year post-taxation (1 March 2015–29 February 2016) measures of (1) beverage prices at 26 Berkeley stores; (2) point-of-sale scanner data on 15.5 million checkouts for beverage prices, sales, and store revenue for two supermarket chains covering three Berkeley and six control non-Berkeley large supermarkets in adjacent cities; and (3) a representative telephone survey (17.4% cooperation rate) of 957 adult Berkeley residents. Key hypotheses were that (1) the tax would be passed through to the prices of taxed beverages among the chain stores in which Berkeley implemented the tax in 2015; (2) sales of taxed beverages would decline, and sales of untaxed beverages would rise, in Berkeley stores more than in comparison non-Berkeley stores; (3) consumer spending per transaction (checkout episode) would not increase in Berkeley stores; and (4) self-reported consumption of taxed beverages would decline. Main outcomes and measures included changes in inflation-adjusted prices (cents/ounce), beverage sales (ounces), consumers’ spending measured as store revenue (inflation-adjusted dollars per transaction) in two large chains, and usual beverage intake (grams/day and kilocalories/day). Tax pass-through (changes in the price after imposition of the tax) for SSBs varied in degree and timing by store type and beverage type. Pass-through was complete in large chain supermarkets (+1.07¢/oz, p = 0.001) and small chain supermarkets and chain gas stations (1.31¢/oz, p = 0.004), partial in pharmacies (+0.45¢/oz, p = 0.03), and

Production and analysis of some atomic emission spectra in the vacuum ultraviolet

International Nuclear Information System (INIS)

Meijer, F.G.

1979-01-01

The development of technical facilities for spectra analysis are described including the design, construction and adjustment of a grazing incidence spectrograph for the extreme ultraviolet and the improvements in light sources. The investigations of the fifth and fourth spectra of tantalum, the analysis of the sixth spectrum of tungsten, the extension of the analysis of the fourth spectrum of hafnium and a start of the analysis of the seventh spectrum of rhenium are presented. (C.F.)

Mesospheric front observations by the OH airglow imager carried out at Ferraz Station on King George Island, Antarctic Peninsula, in 2011

Directory of Open Access Journals (Sweden)

G. A. Giongo

2018-02-01

Full Text Available The main goals of this work are to characterize and investigate the potential wave sources of four mesospheric fronts identified in the hydroxyl near-infrared (OH-NIR airglow images, obtained with an all-sky airglow imager installed at Comandante Ferraz Antarctic Station (EACF, as per its Portuguese acronym located on King George Island in the Antarctic Peninsula. We identified and analyzed four mesospheric fronts in 2011 over King George Island. In addition, we investigate the atmospheric background environment between 80 and 100 km altitude and discuss the ducts and propagation conditions for these waves. For that, we used wind data obtained from a meteor radar operated at EACF and temperature data obtained from the TIMED/SABER satellite. The vertical wavenumber squared, m2, was calculated for each of the four waves. Even though no clearly defined duct (indicated by positive values of m2 sandwiched between layers above and below with m2 < 0 was found in any of the events, favorable propagation conditions for horizontal propagation of the fronts were found in three cases. In the fourth case, the wave front did not find any duct support and it appeared to dissipate near the zenith, transferring energy and momentum to the medium and, consequently, accelerating the wind in the wave propagation direction (near to south above the OH peak (88–92 km. The likely wave sources for these four cases were investigated by using meteorological satellite images and in two cases we could find that strong instabilities were potential sources, i.e., a cyclonic activity and a large convective cloud cell. In the other two cases it was not possible to associate troposphere sources as potential candidates for the generation of such wave fronts observed in the mesosphere and secondary wave sources were attributed to these cases.

A Partnership between English Language Learners and a Team of Rocket Scientists: EPO for the NASA SDO Extreme-Ultraviolet Variability Experiment (EVE)

Science.gov (United States)

Buhr, S. M.; Eparvier, F.; McCaffrey, M.; Murillo, M.

2007-12-01

Recent immigrant high school students were successfully engaged in learning about Sun-Earth connections through a partnership with the NASA SDO Extreme-Ultraviolet Variability Experiment (EVE) project. The students were enrolled in a pilot course as part of the Math, Engineering and Science Achievement MESA) program. For many of the students, this was the only science option available to them due to language limitations. The English Language Learner (ELL) students doubled their achievement on a pre- and post-assessment on the content of the course. Students learned scientific content and vocabulary in English with support in Spanish, attended field trips, hosted scientist speakers, built and deployed space weather monitors as part of the Stanford SOLAR project, and gave final presentations in English, showcasing their new computer skills. Teachers who taught the students in other courses noted gains in the students' willingness to use English in class and noted gains in math skills. The MESA-EVE course won recognition as a Colorado MESA Program of Excellence and is being offered again in 2007-08. The course has been broken into modules for use in shorter after-school environments, or for use by EVE scientists who are outside of the Boulder area. Other EVE EPO includes professional development for teachers and content workshops for journalists.

Chromospheric Evaporation in an M1.8 Flare Observed by the Extreme-ultraviolet Imaging Spectrometer (EIS) on Hinode

Science.gov (United States)

Doschek, G. A.; Warren, H. P.

2012-12-01

We discuss observations of chromospheric evaporation for a flare that occurred on 9 March 2012 near 03:30 UT obtained from the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft. This was a multiple event with a strong energy input that reached the M1.8 class when observed by EIS. EIS was in raster mode and fortunately the slit reached almost the exact location of a significant energy input. Also, fortunately EIS obtained a full-CCD spectrum of the flare, i.e., the entire CCD was readout so that data were obtained for about the 500 lines identified in the EIS wavelength ranges. Chromospheric evaporation characterized by 150-200 km/s upflows was observed in several locations in multi-million degree spectral lines of flare ions such as Fe XXII, Fe XXIII, Fe XXIV, with simultaneous 20 - 60 km/s upflows in a host of million degree coronal lines from ions such as Fe XI - Fe XVI. The behavior of cooler, transition region ions such as O VI, Fe VIII, He II, and Fe X is more complex. At a point close to strong energy input, the flare ions reveal an isothermal source with a temperature close to 14 MK. At this point there is a strong downflow in cooler active region lines from ions such as Fe XIII and Fe XIV. Electron densities were obtained from density sensitive lines ratios from Fe XIII and Fe XIV. The results to be presented are refined from the preliminary data given above and combined with context AIA observations for a comparison with predictions of models of chromospheric evaporation as envisaged in the Standard Flare Model.

Occupational applications of ultraviolet radiation

International Nuclear Information System (INIS)

Eriksen, P.

1987-01-01

A large population of workers are exposed to ultraviolet radiation in various occupational environments which often necessitates protection. Since ultraviolet radiation may create other environmental problems an occupational hazard- and protection evaluation can be complicated. Threshold Limit Values adopted by the American Conference of Governmental Industrial Hygienists (ACGIH) on ultraviolet radiation are used in most countries as guidelines for risk assessment and control measures. This review addresses the levels of ultraviolet radiation met in occupational environments, its measurement and evaluation, and discusses different protection methods. Ultraviolet lasers are beginning to find their way into industrial processes but are still limited in number and they will not be covered here. Emphasis is on broad band incoherent radiation in high risk environments such as welding, and on the evaluation of protective eyewear, see-through curtains and plastics. Other occupational risks associated with the emission of ultraviolet radiation are discussed

Surface modification of organic polymer by dual action of extreme ultraviolet/visible-near infrared ultrashort pulses

Czech Academy of Sciences Publication Activity Database

Mocek, Tomáš; Polan, Jiří; Homer, Pavel; Jakubczak, Krzysztof; Rus, Bedřich; Kim, I. J.; Kim, C. M.; Lee, G.H.; Nam, C. H.; Hájková, Věra; Chalupský, Jaromír; Juha, Libor

2009-01-01

Roč. 105, č. 2 (2009), 026105/1-026105/3 ISSN 0021-8979 R&D Projects: GA AV ČR KAN300100702; GA MŠk(CZ) LC528; GA MŠk LA08024; GA ČR GC202/07/J008 Institutional research plan: CEZ:AV0Z10100523 Keywords : high-speed optical techniques * polymers * surface structure * ultraviolet radiation effects Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.072, year: 2009

Environmental surveillance program of the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Thomas, R.H.

1976-04-01

The major radiological environmental impact of the Lawrence Berkeley Laboratory is due to the operation of four particle accelerators. Potential sources of population exposure at the Laboratory are discussed. The major source of population exposure due to accelerator operation arises from the prompt radiation field which consists principally of neutrons and photons. Release of small quantities of radionuclides is also a potential source of population exposure but is usually an order of magnitude less significant. Accelerator produced radiation levels at the Laboratory boundary are comparable with the magnitudes of the fluctuations found in the natural background radiation. Environmental monitoring of accelerator-produced radiation and of radionuclides is carried on throughout the Laboratory, at the Laboratory perimeter, and in the regions surrounding the Laboratory. The techniques used are described. The models used to calculate population exposure are described and discussed

An Evaluation of the New Curriculum at the University of California, Berkeley, School of Optometry.

Science.gov (United States)

Harris, Michael G.; Kashani, Sandy; Saroj, Namrata

2001-01-01

Evaluated the new curriculum at the University of California, Berkeley, School of Optometry by comparing the content of the new curriculum to the old curriculum and by surveying faculty and students regarding their opinion of the new curriculum. Findings indicated that the curriculum is successful in implementing desired changes, including reduced…

Sensitivity enhancement of chemically amplified resists and performance study using extreme ultraviolet interference lithography

Science.gov (United States)

Buitrago, Elizabeth; Nagahara, Seiji; Yildirim, Oktay; Nakagawa, Hisashi; Tagawa, Seiichi; Meeuwissen, Marieke; Nagai, Tomoki; Naruoka, Takehiko; Verspaget, Coen; Hoefnagels, Rik; Rispens, Gijsbert; Shiraishi, Gosuke; Terashita, Yuichi; Minekawa, Yukie; Yoshihara, Kosuke; Oshima, Akihiro; Vockenhuber, Michaela; Ekinci, Yasin

2016-07-01

Extreme ultraviolet lithography (EUVL, λ=13.5 nm) is the most promising candidate to manufacture electronic devices for future technology nodes in the semiconductor industry. Nonetheless, EUVL still faces many technological challenges as it moves toward high-volume manufacturing (HVM). A key bottleneck from the tool design and performance point of view has been the development of an efficient, high-power EUV light source for high throughput production. Consequently, there has been extensive research on different methodologies to enhance EUV resist sensitivity. Resist performance is measured in terms of its ultimate printing resolution, line width roughness (LWR), sensitivity [S or best energy (BE)], and exposure latitude (EL). However, there are well-known fundamental trade-off relationships (line width roughness, resolution and sensitivity trade-off) among these parameters for chemically amplified resists (CARs). We present early proof-of-principle results for a multiexposure lithography process that has the potential for high sensitivity enhancement without compromising other important performance characteristics by the use of a "Photosensitized Chemically Amplified Resist™" (PSCAR™). With this method, we seek to increase the sensitivity by combining a first EUV pattern exposure with a second UV-flood exposure (λ=365 nm) and the use of a PSCAR. In addition, we have evaluated over 50 different state-of-the-art EUV CARs. Among these, we have identified several promising candidates that simultaneously meet sensitivity, LWR, and EL high-performance requirements with the aim of resolving line space (L/S) features for the 7- and 5-nm logic node [16- and 13-nm half-pitch (HP), respectively] for HVM. Several CARs were additionally found to be well resolved down to 12- and 11-nm HP with minimal pattern collapse and bridging, a remarkable feat for CARs. Finally, the performance of two negative tone state-of-the-art alternative resist platforms previously investigated

Validity and Reliability of Preschool, First and Second Grade Versions of Berkeley Parenting Self-Efficacy Scale

Directory of Open Access Journals (Sweden)

Shahrbanoo Tajeri

2009-02-01

Full Text Available "nObjective: The purpose of this study is to examine the factor structure, internal consistency, and construct validity of preschool, first and second grade versions of Berkeley Parenting self-efficacy scale. "nMethod:  The subjects were 317 mothers: (102 mothers of preschool children, 111 mothers of first grade children and 104 mothers of second grade children who were randomly selected from schools in Tehran. They completed Berkeley parenting self-efficacy and Rotter `s locus of control scales. Factor analysis using the principle component method was used to identify the factor structure of parenting self-efficacy scale. Cronbach`s alpha coefficient was used to identify the reliability of parenting self efficacy scale. "nResults: Results of this study indicated that the cronbach`s alpha coefficient was 0.84, 0.87, 0.64 for preschool, first grade and second grade versions respectively. Based on the scree test ,,factor analysis produced two factors of maternal strategy and child outcome, and it also produced the highest level of total variance explained by these 2 factors. The Parenting self-efficacy scale was negatively associated with measure of locus of control(r=-0.54 for the preschool version, -0.64 for the first grade version and -0.54 for the second grade version. "nConclusion: Due to relatively high reliability and validity of preschool, first and second grade versions of Berkeley Parenting Self-Efficacy scale, this scale could be used as a reliable and valid scale in other research areas

High-resolution extreme ultraviolet spectroscopy of G191-B2B: structure of the stellar photosphere and the surrounding interstellar medium

Science.gov (United States)

Barstow, M. A.; Cruddace, R. G.; Kowalski, M. P.; Bannister, N. P.; Yentis, D.; Lapington, J. S.; Tandy, J. A.; Hubeny, I.; Schuh, S.; Dreizler, S.; Barbee, T. W.

2005-10-01

We have continued our detailed analysis of the high-resolution (R= 4000) spectroscopic observation of the DA white dwarf G191-B2B, obtained by the Joint Astrophysical Plasmadynamic Experiment (J-PEX) normal incidence sounding rocket-borne telescope, comparing the observed data with theoretical predictions for both homogeneous and stratified atmosphere structures. We find that the former models give the best agreement over the narrow waveband covered by J-PEX, in conflict with what is expected from previous studies of the lower resolution but broader wavelength coverage Extreme Ultraviolet Explorer spectra. We discuss the possible limitations of the atomic data and our understanding of the stellar atmospheres that might give rise to this inconsistency. In our earlier study, we obtained an unusually high ionization fraction for the ionized HeII present along the line of sight to the star. In the present paper, we obtain a better fit when we assume, as suggested by Space Telescope Imaging Spectrograph results, that this HeII resides in two separate components. When one of these is assigned to the local interstellar cloud, the implied He ionization fraction is consistent with measurements along other lines of sight. However, the resolving power and signal-to-noise available from the instrument configuration used in this first successful J-PEX flight are not sufficient to clearly identify and prove the existence of the two components.

Probing the Production of Extreme-ultraviolet Late-phase Solar Flares Using the Model Enthalpy-based Thermal Evolution of Loops

Science.gov (United States)

Dai, Yu; Ding, Mingde

2018-04-01

Recent observations in extreme-ultraviolet (EUV) wavelengths reveal an EUV late phase in some solar flares that is characterized by a second peak in warm coronal emissions (∼3 MK) several tens of minutes to a few hours after the soft X-ray (SXR) peak. Using the model enthalpy-based thermal evolution of loops (EBTEL), we numerically probe the production of EUV late-phase solar flares. Starting from two main mechanisms of producing the EUV late phase, i.e., long-lasting cooling and secondary heating, we carry out two groups of numerical experiments to study the effects of these two processes on the emission characteristics in late-phase loops. In either of the two processes an EUV late-phase solar flare that conforms to the observational criteria can be numerically synthesized. However, the underlying hydrodynamic and thermodynamic evolutions in late-phase loops are different between the two synthetic flare cases. The late-phase peak due to a long-lasting cooling process always occurs during the radiative cooling phase, while that powered by a secondary heating is more likely to take place in the conductive cooling phase. We then propose a new method for diagnosing the two mechanisms based on the shape of EUV late-phase light curves. Moreover, from the partition of energy input, we discuss why most solar flares are not EUV late flares. Finally, by addressing some other factors that may potentially affect the loop emissions, we also discuss why the EUV late phase is mainly observed in warm coronal emissions.

Public census data on CD-ROM at Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

Merrill, D.W.

1992-07-02

In connection with the Comprehensive Epidemiologic Data Resource (CEDR) and Populations at Risk to Environmental Pollution (PAREP) projects, of the Information and Computing Sciences Division (ICSD) at Lawrence Berkeley Laboratory (LBL), are using public socioeconomic and geographic data files which are available to CEDR and PAREP collaborators via LBL's computing network. At this time 67 CD-ROM diskettes (approximately 35 gigabytes) are on line via the Unix file server cedrcd.lbl.gov. Most of the files are from the US Bureau of the Census, and most pertain to the 1990 Census of Population and Housing. This paper contains a list of the CD-ROMs available.

DNA Repair and Photoprotection: Mechanisms of Overcoming Environmental Ultraviolet Radiation Exposure in Halophilic Archaea

OpenAIRE

Daniel L. Jones; Bonnie K. Baxter

2017-01-01

Halophilic archaea push the limits of life at several extremes. In particular, they are noted for their biochemical strategies in dealing with osmotic stress, low water activity and cycles of desiccation in their hypersaline environments. Another feature common to their habitats is intense ultraviolet (UV) radiation, which is a challenge that microorganisms must overcome. The consequences of high UV exposure include DNA lesions arising directly from bond rearrangement of adjacent bipyrimidine...

LAUE lens development at UC Berkeley: status and prospects

Science.gov (United States)

Barrière, Nicolas M.; Tomsick, John A.; Ackermann, Marcelo D.; Bastie, Pierre; Boggs, Steven E.; Hanlon, Lorraine; Jentschel, Michael; Lowell, Alexander; Roudil, Gilles; von Ballmoos, Peter; Wade, Colin

2013-09-01

We report on the status of the Laue lens development effort led by UC Berkeley, where a dedicated X-ray beamline and a Laue lens assembly station were built. This allowed the realization of a first lens prototype in June 2012. Based on this achievement, and thanks to a new NASA APRA grant, we are moving forward to enable Laue lenses. Several parallel activities are in progress. Firstly, we are refining the method to glue quickly and accurately crystals on a lens substrate. Secondly, we are conducting a study of high-Z crystals to diffract energies up to 900 keV efficiently. And thirdly, we are exploring new concepts of Si-based lenses that could further improve the focusing capabilities, and thus the sensitivity of Laue lenses.

Vacuum ultraviolet backgrounds from space - Ten years after

International Nuclear Information System (INIS)

Huffman, R.E.; Larrabee, J.C.; Leblanc, F.J.

1989-01-01

The airglow, scattering, and auroral emission sources of the VUV background of the earth's atmosphere set limits on the usefulness of UV space observations, but facilitate such passive remote sensing types as electron density profiling and auroral location and strength determinations, which are presently discussed. UV auroral imaging has to date been conducted by four different experiments: (1) the VUV Backgrounds observations (flown on the S3-4 satellite in 1978); (2) the Horizon UV Program experiment (flown on STS-4 in 1982); the HILAT satellite's Atmospheric/Ionospheric Monitor (1986); and the Atmospheric/Ionospheric Remote Sensor (flown on the Polar BEAR satellite, 1988-1989). 18 refs

The Advanced Light Source: A new 1.5 GeV synchrotron radiation facility at the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Schlachter, F.

1990-01-01

The Advanced Light Source (ALS), presently under construction at the Lawrence Berkeley Laboratory, will be the world's brightest synchrotron-radiation source of ultraviolet and soft x-ray photons when it opens its doors to users in April 1993. The ALS is a third-generation source that is based on a low-emittance electron storage ring, optimized for operation at 1.5 GeV, with long straight sections for insertion devices. Its naturally short pulses are ideal for time-resolved measurements. Undulators will produce high-brightness beams from below 10 eV to above 2 keV; wigglers will produce high fluxes of harder x-rays to energies above 10 keV. The ALS will support an extensive research program in a broad spectrum of scientific and technological areas. The high brightness will open new areas of research in the materials sciences, such as spatially resolved spectroscopy (spectromicroscopy). Biological applications will include x-ray microscopy with element-specific sensitivity in the water window of the spectrum where water is much more transparent than protein. The ALS will be an excellent research tool for atomic physics and chemistry because the high flux will allow measurements to be made with tenuous gas-phase targets. Undulator radiation can excite the K shell of elements up to silicon and the L shell of elements up to krypton, and wiggler radiation can excite the L shell of nearly every element. The ALS will operate as a national user facility; interested scientists are encouraged to contact the ALS Scientific Program Coordinator to explore their scientific and technological research interests

Follow the Money: Engineering at Stanford and UC Berkeley during the Rise of Silicon Valley

Science.gov (United States)

Adams, Stephen B.

2009-01-01

A comparison of the engineering schools at UC Berkeley and Stanford during the 1940s and 1950s shows that having an excellent academic program is necessary but not sufficient to make a university entrepreneurial (an engine of economic development). Key factors that made Stanford more entrepreneurial than Cal during this period were superior…

Effect of ultraviolet light on creatinine measurement in jaundiced specimens

International Nuclear Information System (INIS)

Nisbet, J.A.; D'Souza, R.

1986-01-01

During initial evaluation of a creatinine method using the RA-1000 analyser, experiments with addition of bilirubin indicated negligible interference. However the finding of a 'zero' creatinine value in an extremely jaundiced specimen prompted to re-examine the method. In contrast to earlier findings with normal plasma containing added bilirubin, the authors found that plasma from moderately or severely jaundiced patients gave creatinine values lower than those obtained with a reference method. Since bilirubin has been implicated in the interference, the authors studied the effect of destroying bilirubin with ultraviolet light to see if this provided a practical solution to the problem. (Auth.)

Development of a Large-Format Science-Grade CMOS Active Pixel Sensor, for Extreme Ultra Violet Spectroscopy and Imaging in Space Science

National Research Council Canada - National Science Library

Waltham, N. R; Prydderch, M; Mapson-Menard, H; Morrissey, Q; Turchetta, R; Pool, P; Harris, A

2005-01-01

We describe our programme to develop a large-format science-grade CMOS active pixel sensor for future space science missions, and in particular an extreme ultra-violet spectrograph for solar physics...

Public census data on CD-ROM at Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

Merrill, D.W.

1993-01-16

The Comprehensive Epidemiologic Data Resource (CEDR) and Populations at Risk to Environmental Pollution (PAREP) projects, of the Information and Computing Sciences Division (ICSD) at Lawrence Berkeley Laboratory (LBL), are using public socioeconomic and geographic data files which are available to CEDR and PAREP collaborators via LBL's computing network. At this time 72 CD-ROM diskettes (approximately 37 gigabytes) are on line via the Unix file server cedrcd.lbl.gov''. Most of the files are from the US Bureau of the Census, and many of these pertain to the 1990 Census of Population and Housing. All the CD-ROM diskettes contain documentation in the form of ASCII text files. In addition, printed documentation for most files is available for inspection at University of California Data and Technical Assistance (UC DATA), tel. (510) 642-6571, or the UC Documents Library, tel. (510) 642-2569, both located on the UC Berkeley Campus. Many of the CD-ROM diskettes distributed by the Census Bureau contain software for PC compatible computers, for easily accessing the data. Shared access to the data is maintained through a collaboration among the CEDR and PAREP projects at LBL, and UC DATA, and the UC Documents Library. LBL is grateful to UC DATA and the UC Documents Library for the use of their CD-ROM diskettes. Shared access to LBL facilities may be restricted in the future if costs become prohibitive. Via the Sun Network File System (NFS), these data can be exported to Internet computers for direct access by the user's application program(s). Due to the size of the files, this access method is preferred over File Transfer Protocol (FTP) access. Please contact Deane Merrill (dwmerrill lbl.gov) if you wish to make use of the data.

Presentation of the National Center for Research in Vocational Education [Berkeley, California] at the AVA Annual Conference.

Science.gov (United States)

National Center for Research in Vocational Education, Berkeley, CA.

This collection contains the following conference presentations about the National Center for Research in Vocational Education at the University of California at Berkeley: "Visions and Principles" (Charles Benson); "How the Center Sees Its Role" (Gordon Swanson); "The Research Agenda" (Sue Berryman); "The Service…

Photodissociation of aligned CH3I and C6H3F2I molecules probed with time-resolved Coulomb explosion imaging by site-selective extreme ultraviolet ionization.

Science.gov (United States)

Amini, Kasra; Savelyev, Evgeny; Brauße, Felix; Berrah, Nora; Bomme, Cédric; Brouard, Mark; Burt, Michael; Christensen, Lauge; Düsterer, Stefan; Erk, Benjamin; Höppner, Hauke; Kierspel, Thomas; Krecinic, Faruk; Lauer, Alexandra; Lee, Jason W L; Müller, Maria; Müller, Erland; Mullins, Terence; Redlin, Harald; Schirmel, Nora; Thøgersen, Jan; Techert, Simone; Toleikis, Sven; Treusch, Rolf; Trippel, Sebastian; Ulmer, Anatoli; Vallance, Claire; Wiese, Joss; Johnsson, Per; Küpper, Jochen; Rudenko, Artem; Rouzée, Arnaud; Stapelfeldt, Henrik; Rolles, Daniel; Boll, Rebecca

2018-01-01

We explore time-resolved Coulomb explosion induced by intense, extreme ultraviolet (XUV) femtosecond pulses from a free-electron laser as a method to image photo-induced molecular dynamics in two molecules, iodomethane and 2,6-difluoroiodobenzene. At an excitation wavelength of 267 nm, the dominant reaction pathway in both molecules is neutral dissociation via cleavage of the carbon-iodine bond. This allows investigating the influence of the molecular environment on the absorption of an intense, femtosecond XUV pulse and the subsequent Coulomb explosion process. We find that the XUV probe pulse induces local inner-shell ionization of atomic iodine in dissociating iodomethane, in contrast to non-selective ionization of all photofragments in difluoroiodobenzene. The results reveal evidence of electron transfer from methyl and phenyl moieties to a multiply charged iodine ion. In addition, indications for ultrafast charge rearrangement on the phenyl radical are found, suggesting that time-resolved Coulomb explosion imaging is sensitive to the localization of charge in extended molecules.

Using synchrotron light to accelerate EUV resist and mask materials learning

Science.gov (United States)

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

2011-03-01

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

Life sciences: Lawrence Berkeley Laboratory, 1988

International Nuclear Information System (INIS)

1989-07-01

Life Sciences Research at LBL has both a long history and a new visibility. The physics technologies pioneered in the days of Ernest O. Lawrence found almost immediate application in the medical research conducted by Ernest's brother, John Lawrence. And the tradition of nuclear medicine continues today, largely uninterrupted for more than 50 years. Until recently, though, life sciences research has been a secondary force at the Lawrence Berkeley Laboratory (LBL). Today, a true multi-program laboratory has emerged, in which the life sciences participate as a full partner. The LBL Human Genome Center is a contribution to the growing international effort to map the human genome. Its achievements represent LBL divisions, including Engineering, Materials and Chemical Sciences, and Information and Computing Sciences, along with Cell and Molecular Biology and Chemical Biodynamics. The Advanced Light Source Life Sciences Center will comprise not only beamlines and experimental end stations, but also supporting laboratories and office space for scientists from across the US. This effort reflects a confluence of scientific disciplines --- this time represented by individuals from the life sciences divisions and by engineers and physicists associated with the Advanced Light Source project. And finally, this report itself, the first summarizing the efforts of all four life sciences divisions, suggests a new spirit of cooperation. 30 figs

At-wavelength interferometry of high-NA diffraction-limited EUV optics

Energy Technology Data Exchange (ETDEWEB)

Goldberg, Kenneth A.; Naulleau, Patrick; Rekawa, Senajith; Denham, Paul; Liddle, J. Alexander; Anderson, Erik; Jackson, Keith; Bokor, Jeffrey; Attwood, David

2003-08-01

Recent advances in all-reflective diffraction-limited optical systems designed for extreme ultraviolet (EUV) lithography have pushed numerical aperture (NA) values from 0.1 to 0.3, providing Rayleigh resolutions of 27-nm. Worldwide, several high-NA EUV optics are being deployed to serve in the development of advanced lithographic techniques required for EUV lithography, including the creation and testing of new, high-resolution photoresists. One such system is installed on an undulator beamline at Lawrence Berkeley National Laboratory's Advanced Light Source. Sub{angstrom}-accuracy optical testing and alignment techniques, developed for use with the previous generations of EUV lithographic optical systems, are being extended for use at high NA. Considerations for interferometer design and use are discussed.

Initiation and early evolution of the coronal mass ejection on 2009 May 13 from extreme-ultraviolet and white-light observations

International Nuclear Information System (INIS)

Reva, A. A.; Ulyanov, A. S.; Bogachev, S. A.; Kuzin, S. V.

2014-01-01

We present the results of the observations of a coronal mass ejection (CME) that occurred on 2009 May 13. The most important feature of these observations is that the CME was observed from the very early stage (the solar surface) up to a distance of 15 solar radii (R ☉ ). Below 2 R ☉ , we used the data from the TESIS extreme-ultraviolet telescopes obtained in the Fe 171 Å and He 304 Å lines, and above 2 R ☉ , we used the observations of the LASCO C2 and C3 coronagraphs. The CME was formed at a distance of 0.2-0.5R ☉ from the Sun's surface as a U-shaped structure, which was observed both in the 171 Å images and in the white light. Observations in the He 304 Å line showed that the CME was associated with an erupting prominence, which was not located above—as the standard model predicts—but rather in the lowest part of the U-shaped structure close to the magnetic X point. The prominence location can be explained with the CME breakout model. Estimates showed that CME mass increased with time. The CME trajectory was curved—its heliolatitude decreased with time. The CME started at a latitude of 50° and reached the ecliptic plane at distances of 2.5 R ☉ . The CME kinematics can be divided into three phases: initial acceleration, main acceleration, and propagation with constant velocity. After the CME, onset GOES registered a sub-A-class flare.

Initiation and Early Evolution of the Coronal Mass Ejection on 2009 May 13 from Extreme-ultraviolet and White-light Observations

Science.gov (United States)

Reva, A. A.; Ulyanov, A. S.; Bogachev, S. A.; Kuzin, S. V.

2014-10-01

We present the results of the observations of a coronal mass ejection (CME) that occurred on 2009 May 13. The most important feature of these observations is that the CME was observed from the very early stage (the solar surface) up to a distance of 15 solar radii (R ⊙). Below 2 R ⊙, we used the data from the TESIS extreme-ultraviolet telescopes obtained in the Fe 171 Å and He 304 Å lines, and above 2 R ⊙, we used the observations of the LASCO C2 and C3 coronagraphs. The CME was formed at a distance of 0.2-0.5R ⊙ from the Sun's surface as a U-shaped structure, which was observed both in the 171 Å images and in the white light. Observations in the He 304 Å line showed that the CME was associated with an erupting prominence, which was not located above—as the standard model predicts—but rather in the lowest part of the U-shaped structure close to the magnetic X point. The prominence location can be explained with the CME breakout model. Estimates showed that CME mass increased with time. The CME trajectory was curved—its heliolatitude decreased with time. The CME started at a latitude of 50° and reached the ecliptic plane at distances of 2.5 R ⊙. The CME kinematics can be divided into three phases: initial acceleration, main acceleration, and propagation with constant velocity. After the CME, onset GOES registered a sub-A-class flare.

Initiation and early evolution of the coronal mass ejection on 2009 May 13 from extreme-ultraviolet and white-light observations

Energy Technology Data Exchange (ETDEWEB)

Reva, A. A.; Ulyanov, A. S.; Bogachev, S. A.; Kuzin, S. V., E-mail: reva.antoine@gmail.com [Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninskij Prospekt, 119991 Moscow (Russian Federation)

2014-10-01

We present the results of the observations of a coronal mass ejection (CME) that occurred on 2009 May 13. The most important feature of these observations is that the CME was observed from the very early stage (the solar surface) up to a distance of 15 solar radii (R {sub ☉}). Below 2 R {sub ☉}, we used the data from the TESIS extreme-ultraviolet telescopes obtained in the Fe 171 Å and He 304 Å lines, and above 2 R {sub ☉}, we used the observations of the LASCO C2 and C3 coronagraphs. The CME was formed at a distance of 0.2-0.5R {sub ☉} from the Sun's surface as a U-shaped structure, which was observed both in the 171 Å images and in the white light. Observations in the He 304 Å line showed that the CME was associated with an erupting prominence, which was not located above—as the standard model predicts—but rather in the lowest part of the U-shaped structure close to the magnetic X point. The prominence location can be explained with the CME breakout model. Estimates showed that CME mass increased with time. The CME trajectory was curved—its heliolatitude decreased with time. The CME started at a latitude of 50° and reached the ecliptic plane at distances of 2.5 R {sub ☉}. The CME kinematics can be divided into three phases: initial acceleration, main acceleration, and propagation with constant velocity. After the CME, onset GOES registered a sub-A-class flare.

Early History of Heavy Isotope Research at Berkeley

Energy Technology Data Exchange (ETDEWEB)

Glenn T. Seaborg

1976-06-01

I have had the idea for some time that it would be interesting and worthwhile to put together an account of the early work on heavy isotopes at Berkeley. Of a special interest is the discovery of plutonium (atomic number 94) and the isotope U{sup 233}, and the demonstration of their fission with slow neutrons. This work served as a prelude to the subsequent Plutonium Project (Metallurgical Project) centered at the University of Chicago, in connection with which I have also had the idea of putting together a history of the work of my chemistry group. I have decided that it would be an interesting challenge to write this account on a day-to-day basis in a style that would be consistent with the entries having been written at the end of each day. The aim would be to make this history as accurate as possible by going back to the original records and using them with meticulous care.

Spin-Off Successes of SETI Research at Berkeley

Science.gov (United States)

Douglas, K. A.; Anderson, D. P.; Bankay, R.; Chen, H.; Cobb, J.; Korpela, E. J.; Lebofsky, M.; Parsons, A.; von Korff, J.; Werthimer, D.

2009-12-01

Our group contributes to the Search for Extra-Terrestrial Intelligence (SETI) by developing and using world-class signal processing computers to analyze data collected on the Arecibo telescope. Although no patterned signal of extra-terrestrial origin has yet been detected, and the immediate prospects for making such a detection are highly uncertain, the SETI@home project has nonetheless proven the value of pursuing such research through its impact on the fields of distributed computing, real-time signal processing, and radio astronomy. The SETI@home project has spun off the Center for Astronomy Signal Processing and Electronics Research (CASPER) and the Berkeley Open Infrastructure for Networked Computing (BOINC), both of which are responsible for catalyzing a smorgasbord of new research in scientific disciplines in countries around the world. Futhermore, the data collected and archived for the SETI@home project is proving valuable in data-mining experiments for mapping neutral galatic hydrogen and for detecting black-hole evaporation.

Optimizing Excited-State Electronic-Structure Codes for Intel Knights Landing: A Case Study on the BerkeleyGW Software

Energy Technology Data Exchange (ETDEWEB)

Deslippe, Jack; da Jornada, Felipe H.; Vigil-Fowler, Derek; Barnes, Taylor; Wichmann, Nathan; Raman, Karthik; Sasanka, Ruchira; Louie, Steven G.

2016-10-06

We profile and optimize calculations performed with the BerkeleyGW code on the Xeon-Phi architecture. BerkeleyGW depends both on hand-tuned critical kernels as well as on BLAS and FFT libraries. We describe the optimization process and performance improvements achieved. We discuss a layered parallelization strategy to take advantage of vector, thread and node-level parallelism. We discuss locality changes (including the consequence of the lack of L3 cache) and effective use of the on-package high-bandwidth memory. We show preliminary results on Knights-Landing including a roofline study of code performance before and after a number of optimizations. We find that the GW method is particularly well-suited for many-core architectures due to the ability to exploit a large amount of parallelism over plane-wave components, band-pairs, and frequencies.

Extreme-UV electrical discharge source

Science.gov (United States)

Fornaciari, Neal R.; Nygren, Richard E.; Ulrickson, Michael A.

2002-01-01

An extreme ultraviolet and soft x-ray radiation electric capillary discharge source that includes a boron nitride housing defining a capillary bore that is positioned between two electrodes one of which is connected to a source of electric potential can generate a high EUV and soft x-ray radiation flux from the capillary bore outlet with minimal debris. The electrode that is positioned adjacent the capillary bore outlet is typically grounded. Pyrolytic boron nitride, highly oriented pyrolytic boron nitride, and cubic boron nitride are particularly suited. The boron nitride capillary bore can be configured as an insert that is encased in an exterior housing that is constructed of a thermally conductive material. Positioning the ground electrode sufficiently close to the capillary bore outlet also reduces bore erosion.

Phototherapy cabinet for ultraviolet radiation therapy

International Nuclear Information System (INIS)

Horwitz, S.N.; Frost, P.

1981-01-01

A newly designed cabinet can be used for the treatment of psoriasis with fluorescent ultraviolet (UV) lamps. the new design provides more uniform distribution of UV radiation in both the horizontal and vertical axes, and several safety features have been added. The distribution and uniformity of UV output in this and in a previously described cabinet are compared. The UV output at the vertical center of the older UV light cabinet was six times greater than that at either the top or bottom, while the design of the present cabinet provides uniform UV radiation except for a slight increase at head height and at the level of the lower legs compared with the middle third of the cabinet. The variation in output of the older cabinet may, in part, explain the commonly encountered difficulty in the phototherapy of psoriasis of the scalp and lower extremities

BErkeley Atmospheric CO2 Network (BEACON) - Bringing Measurements of CO2 Emissions to a School Near You

Science.gov (United States)

Teige, V. E.; Havel, E.; Patt, C.; Heber, E.; Cohen, R. C.

2011-12-01

The University of California at Berkeley in collaboration with the Chabot Space and Science Center describe a set of educational programs, workshops, and exhibits based on a multi-node greenhouse gas and air quality monitoring network being deployed over Oakland, California. Examining raw numerical data using highly engaging and effective geo-data visualization tools like Google Earth can make the science come alive for students, and provide a hook for drawing them into deeper investigations. The Climate Science Investigations teacher workshop at the Chabot Space and Science Center will make use of Google Earth, Excel, and other geo-data visualization tools to step students through the process from data acquisition to discovery. Using multiple data sources, including output from the BErkeley Atmospheric CO2 Network (BEACON) project, participants will be encouraged to explore a variety of different modes of data display toward producing a unique, and ideally insightful, illumination of the data.

Extreme ultraviolet interferometry

Energy Technology Data Exchange (ETDEWEB)

Goldberg, Kenneth A. [Univ. of California, Berkeley, CA (United States). Dept. of Physics

1997-12-01

EUV lithography is a promising and viable candidate for circuit fabrication with 0.1-micron critical dimension and smaller. In order to achieve diffraction-limited performance, all-reflective multilayer-coated lithographic imaging systems operating near 13-nm wavelength and 0.1 NA have system wavefront tolerances of 0.27 nm, or 0.02 waves RMS. Owing to the highly-sensitive resonant reflective properties of multilayer mirrors and extraordinarily tight tolerances set forth for their fabrication, EUV optical systems require at-wavelength EUV interferometry for final alignment and qualification. This dissertation discusses the development and successful implementation of high-accuracy EUV interferometric techniques. Proof-of-principle experiments with a prototype EUV point-diffraction interferometer for the measurement of Fresnel zoneplate lenses first demonstrated sub-wavelength EUV interferometric capability. These experiments spurred the development of the superior phase-shifting point-diffraction interferometer (PS/PDI), which has been implemented for the testing of an all-reflective lithographic-quality EUV optical system. Both systems rely on pinhole diffraction to produce spherical reference wavefronts in a common-path geometry. Extensive experiments demonstrate EUV wavefront-measuring precision beyond 0.02 waves RMS. EUV imaging experiments provide verification of the high-accuracy of the point-diffraction principle, and demonstrate the utility of the measurements in successfully predicting imaging performance. Complementary to the experimental research, several areas of theoretical investigation related to the novel PS/PDI system are presented. First-principles electromagnetic field simulations of pinhole diffraction are conducted to ascertain the upper limits of measurement accuracy and to guide selection of the pinhole diameter. Investigations of the relative merits of different PS/PDI configurations accompany a general study of the most significant sources of systematic measurement errors. To overcome a variety of experimental difficulties, several new methods in interferogram analysis and phase-retrieval were developed: the Fourier-Transform Method of Phase-Shift Determination, which uses Fourier-domain analysis to improve the accuracy of phase-shifting interferometry; the Fourier-Transform Guided Unwrap Method, which was developed to overcome difficulties associated with a high density of mid-spatial-frequency blemishes and which uses a low-spatial-frequency approximation to the measured wavefront to guide the phase unwrapping in the presence of noise; and, finally, an expedient method of Gram-Schmidt orthogonalization which facilitates polynomial basis transformations in wave-front surface fitting procedures.

Summary of daily observational results of solar phenomena, cosmic ray, geomagnetic variation, ionosphere, radio wave propagation and airglow

International Nuclear Information System (INIS)

Anon.

1976-01-01

The diagrams in this section of the publication illustrate the summary of daily observational results of solar phenomena, cosmic ray, geomagnetic variation, ionosphere, radio wave propagation and airglow observed in Japan. For convenience, the observational results are arranged by the solar rotation number. The aim of this illustration is to disseminate an outline of daily events observed in Japan for the benefit of active research workers who plan to make detailed study of the specific solar and terrestrial events. Therefore, the illustrations do not show all observational results in Japan but only representative ones at some key stations in Japan. They will suffice for the present purpose. The method of illustration shown in the instruction on the next page is still a preliminary one, and it is subject to change resulting from the kind advice of the users of this part of the publication. We welcome any advice for making the data arrangement and expression better and more convenient. (auth.)

Limitations of Extreme Nonlinear Ultrafast Nanophotonics

Directory of Open Access Journals (Sweden)

Kern Christian

2015-01-01

Full Text Available High-harmonic generation (HHG has been established as an indispensable tool in optical spectroscopy. This effect arises for instance upon illumination of a noble gas with sub-picosecond laser pulses at focussed intensities significantly greater than 1012W/cm2. HHG provides a coherent light source in the extreme ultraviolet (XUV spectral region, which is of importance in inner shell photo ionization of many atoms and molecules. Additionally, it intrinsically features light fields with unique temporal properties. Even in its simplest realization, XUV bursts of sub-femtosecond pulse lengths are released. More sophisticated schemes open the path to attosecond physics by offering single pulses of less than 100 attoseconds duration.

Actinic imaging of native and programmed defects on a full-field mask

Energy Technology Data Exchange (ETDEWEB)

Mochi, I.; Goldberg, K. A.; Fontaine, B. La; Tchikoulaeva, A.; Holfeld, C.

2010-03-12

We describe the imaging and characterization of native defects on a full field extreme ultraviolet (EUV) mask, using several reticle and wafer inspection modes. Mask defect images recorded with the SEMA TECH Berkeley Actinic Inspection Tool (AIT), an EUV-wavelength (13.4 nm) actinic microscope, are compared with mask and printed-wafer images collected with scanning electron microscopy (SEM) and deep ultraviolet (DUV) inspection tools. We observed that defects that appear to be opaque in the SEM can be highly transparent to EUV light, and inversely, defects that are mostly transparent to the SEM can be highly opaque to EUV. The nature and composition of these defects, whether they appear on the top surface, within the multilayer coating, or on the substrate as buried bumps or pits, influences both their significance when printed, and their detectability with the available techniques. Actinic inspection quantitatively predicts the characteristics of printed defect images in ways that may not be possible with non-EUV techniques. As a quantitative example, we investigate the main structural characteristics of a buried pit defect based on EUV through-focus imaging.

Photodetector of ultraviolet radiation

International Nuclear Information System (INIS)

Dorogan, V.; Branzari, V.; Vieru, T.; Manole, M.; Canter, V.

2000-01-01

The invention relates to photodetectors on base of semiconductors of ultraviolet radiation and may be used in optoelectronic system for determining the intensity and the dose of ultraviolet radiation emitted by the Sun or other sources. Summary of the invention consists in the fact that in the photodetector of ultraviolet radiation the superficial potential barrier is divided into two identical elements, electrically isolated each of the other, one of them being covered with a layer of transparent material for visible and infrared radiation and absorption the ultra violet radiation. The technical result consists in mutual compensation of visible and infrared components of the radiation spectrum

Radioactive and mixed waste management plan for the Lawrence Berkeley Laboratory Hazardous Waste Handling Facility

International Nuclear Information System (INIS)

1995-01-01

This Radioactive and Mixed Waste Management Plan for the Hazardous Waste Handling Facility at Lawrence Berkeley Laboratory is written to meet the requirements for an annual report of radioactive and mixed waste management activities outlined in DOE Order 5820.2A. Radioactive and mixed waste management activities during FY 1994 listed here include principal regulatory and environmental issues and the degree to which planned activities were accomplished

An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers

International Nuclear Information System (INIS)

Hilbert, Vinzenz; Fuchs, Silvio; Paulus, Gerhard G.; Zastrau, Ulf; Blinne, Alexander; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Förster, Eckhart

2013-01-01

We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed

An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers.

Science.gov (United States)

Hilbert, Vinzenz; Blinne, Alexander; Fuchs, Silvio; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Paulus, Gerhard G; Förster, Eckhart; Zastrau, Ulf

2013-09-01

We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed.

Ultra-high accuracy optical testing: creating diffraction-limited short-wavelength optical systems

International Nuclear Information System (INIS)

Goldberg, Kenneth A.; Naulleau, Patrick P.; Rekawa, Senajith B.; Denham, Paul E.; Liddle, J. Alexander; Gullikson, Eric M.; Jackson, KeithH.; Anderson, Erik H.; Taylor, John S.; Sommargren, Gary E.; Chapman, Henry N.; Phillion, Donald W.; Johnson, Michael; Barty, Anton; Soufli, Regina; Spiller, Eberhard A.; Walton, Christopher C.; Bajt, Sasa

2005-01-01

Since 1993, research in the fabrication of extreme ultraviolet (EUV) optical imaging systems, conducted at Lawrence Berkeley National Laboratory (LBNL) and Lawrence Livermore National Laboratory (LLNL), has produced the highest resolution optical systems ever made. We have pioneered the development of ultra-high-accuracy optical testing and alignment methods, working at extreme ultraviolet wavelengths, and pushing wavefront-measuring interferometry into the 2-20-nm wavelength range (60-600 eV). These coherent measurement techniques, including lateral shearing interferometry and phase-shifting point-diffraction interferometry (PS/PDI) have achieved RMS wavefront measurement accuracies of 0.5-1-(angstrom) and better for primary aberration terms, enabling the creation of diffraction-limited EUV optics. The measurement accuracy is established using careful null-testing procedures, and has been verified repeatedly through high-resolution imaging. We believe these methods are broadly applicable to the advancement of short-wavelength optical systems including space telescopes, microscope objectives, projection lenses, synchrotron beamline optics, diffractive and holographic optics, and more. Measurements have been performed on a tunable undulator beamline at LBNL's Advanced Light Source (ALS), optimized for high coherent flux; although many of these techniques should be adaptable to alternative ultraviolet, EUV, and soft x-ray light sources. To date, we have measured nine prototype all-reflective EUV optical systems with NA values between 0.08 and 0.30 (f/6.25 to f/1.67). These projection-imaging lenses were created for the semiconductor industry's advanced research in EUV photolithography, a technology slated for introduction in 2009-13. This paper reviews the methods used and our program's accomplishments to date

Future Directions in Ultraviolet Spectroscopy

Science.gov (United States)

Sonneborn, George (Editor); Moos, Warren; VanSteenberg, Michael

2009-01-01

The 'Future Directions in Ultraviolet Spectroscopy' conference was inspired by the accomplishments of the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission. The FUSE mission was launched in June 1999 and spent over eight years exploring the far-ultraviolet universe, gathering over 64 million seconds of high-resolution spectral data on nearly 3000 astronomical targets. The goal of this conference was not only to celebrate the accomplishments of FUSE, but to look toward the future and understand the major scientific drivers for the ultraviolet capabilities of the next generation fo space observatories. Invited speakers presented discussions based on measurements made by FUSE and other ultraviolet instruments, assessed their connection with measurements made with other techniques and, where appropriate, discussed the implications of low-z measurements for high-z phenomena. In addition to the oral presentations, many participants presented poster papers. The breadth of these presentation made it clear that much good science is still in progress with FUSE data and that these result will continue to have relevance in many scientific areas.

Life sciences: Lawrence Berkeley Laboratory, 1988

Energy Technology Data Exchange (ETDEWEB)

1989-07-01

Life Sciences Research at LBL has both a long history and a new visibility. The physics technologies pioneered in the days of Ernest O. Lawrence found almost immediate application in the medical research conducted by Ernest's brother, John Lawrence. And the tradition of nuclear medicine continues today, largely uninterrupted for more than 50 years. Until recently, though, life sciences research has been a secondary force at the Lawrence Berkeley Laboratory (LBL). Today, a true multi-program laboratory has emerged, in which the life sciences participate as a full partner. The LBL Human Genome Center is a contribution to the growing international effort to map the human genome. Its achievements represent LBL divisions, including Engineering, Materials and Chemical Sciences, and Information and Computing Sciences, along with Cell and Molecular Biology and Chemical Biodynamics. The Advanced Light Source Life Sciences Center will comprise not only beamlines and experimental end stations, but also supporting laboratories and office space for scientists from across the US. This effort reflects a confluence of scientific disciplines --- this time represented by individuals from the life sciences divisions and by engineers and physicists associated with the Advanced Light Source project. And finally, this report itself, the first summarizing the efforts of all four life sciences divisions, suggests a new spirit of cooperation. 30 figs.

Exploratory Research and Development Fund, FY 1990. Report on Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

1992-05-01

The Lawrence Berkeley Laboratory Exploratory R&D Fund FY 1990 report is compiled from annual reports submitted by principal investigators following the close of the fiscal year. This report describes the projects supported and summarizes their accomplishments. It constitutes a part of an Exploratory R&D Fund (ERF) planning and documentation process that includes an annual planning cycle, projection selection, implementation, and review. The research areas covered in this report are: Accelerator and fusion research; applied science; cell and molecular biology; chemical biodynamics; chemical sciences; earth sciences; engineering; information and computing sciences; materials sciences; nuclear science; physics and research medicine and radiation biophysics.

WAMDII: The Wide Angle Michelson Doppler Imaging Interferometer

Science.gov (United States)

1992-01-01

As part of an effort to learn more about the upper atmosphere and how it is linked to the weather experienced each day, NASA and NRCC are jointly sponsoring the Wide Angle Michelson Doppler Imaging Interferometer (WAMDII) Mission. WAMDII will measure atmospheric temperature and wind speed in the upper atmosphere. In addition to providing data on the upper atmosphere, the wind speed and temperature readings WAMDII takes will also be highly useful in developing and updating computer simulated models of the upper atmosphere. These models are used in the design and testing of equipment and software for Shuttles, satellites, and reentry vehicles. In making its wind speed and temperature measurements, WAMDII examines the Earth's airglow, a faint photochemical luminescence caused by the influx of solar ultraviolet energy into the upper atmosphere. During periods of high solar flare activity, the amount of this UV energy entering the upper atmosphere increases, and this increase may effect airglow emissions.

Study of CD variation caused by the black border effect and out-of-band radiation in extreme ultraviolet lithography

Science.gov (United States)

Gao, Weimin; Niroomand, Ardavan; Lorusso, Gian F.; Boone, Robert; Lucas, Kevin; Demmerle, Wolfgang

2014-04-01

Although extreme ultraviolet lithography (EUVL) remains a promising candidate for semiconductor device manufacturing of the 1× nm half pitch node and beyond, many technological burdens have to be overcome. The "field edge effect" in EUVL is one of them. The image border region of an EUV mask, also known as the "black border" (BB), reflects a few percent of the incident EUV light, resulting in a leakage of light into neighboring exposure fields, especially at the corner of the field where three adjacent exposures take place. This effect significantly impacts on critical dimension (CD) uniformity (CDU) across the exposure field. To avoid this phenomenon, a light-shielding border is introduced by etching away the entire absorber and multilayer at the image border region of the EUV mask. We present a method of modeling the field edge effect (also called the BB effect) by using rigorous lithography simulation with a calibrated resist model. An additional "flare level" at the field edge is introduced on top of the exposure tool flare map to account for the BB effect. The parameters in this model include the reflectivity and the width of the BB, which are mainly determining the leakage of EUV light and its influence range, respectively. Another parameter is the transition width which represents the half shadow effect of the reticle masking blades. By setting the corresponding parameters, the simulation results match well the experimental results obtained at the IMEC's NXE:3100 EUV exposure tool. Moreover, these results indicate that the out-of-band (OoB) radiation also contributes to the CDU. Using simulation, we can also determine the OoB effect rigorously using the methodology of an "effective mask blank." The study demonstrates that the impact of BB and OoB effects on CDU can be well predicted by simulations.

Ultraviolet transitions from the 2 3P states of helium-like argon

International Nuclear Information System (INIS)

Davis, W.A.

1976-09-01

This thesis describes the observation of two allowed electric dipole transitions in helium-like argon. The transitions are 2 3 P 2 --2 3 S 1 and 2 3 P 0 --2 3 S 1 . These transitions were observed by using a vacuum ultraviolet monochromator to collect photons from decays-in-flight of a beam-foil excited argon ion beam. The ion beam was generated by the Lawrence Berkeley Laboratory heavy ion linear accelerator (SuperHILAC) and had a beam energy of 138 MeV with a charge current of roughly 500 nanoamperes. After initial observation, the lifetimes and absolute wavelengths of these transitions were measured. The results are tau(2 3 P 2 ) = 1.62 +- 0.08 X 10 -9 sec, tau(2 3 P 0 ) = 4.87 +- 0.44 X 10 -9 sec, lambda(2 3 P 2 --2 3 S 1 ) = 560.2 +- 0.9A, and lambda(2 3 P 0 --2 3 S 1 ) = 660.7 +- 1.1A. This work has demonstrated the observability of these transitions in high-Z ions using beam-foil excitation. Employing a new grazing-incidence spectrometer this work will be pursued in ions of higher Z. Accuracies of at least one part in a thousand should be attainable and will probe the radiative contributions to these transitions to better than 10 percent in a previously unstudied region

Radioactive waste management research at CEGB Berkeley nuclear laboratories

International Nuclear Information System (INIS)

Bradbury, D.

1988-01-01

The CEGB is the major electric utility in the United Kingdom. This paper discusses how, at the research laboratories at Berkeley (BNL), several programs of work are currently taking place in the radioactive waste management area. The theme running through all this work is the safe isolation of radionuclides from the environment. Normally this means disposal of waste in solid form, but it may also be desirable to segregate and release nonradioactive material from the waste to reduce volume or improve the solid waste characteristics (e.g., the release of liquid or gaseous effluents after treatment to convert the radioactivity to solid form). The fuel cycle and radioactive waste section at BNL has a research program into these aspects for wastes arising from the operation or decommissioning of power stations. The work is done both in-house and on contract, with primarily the UKAEA

Vacuum-Ultraviolet Photovoltaic Detector.

Science.gov (United States)

Zheng, Wei; Lin, Richeng; Ran, Junxue; Zhang, Zhaojun; Ji, Xu; Huang, Feng

2018-01-23

Over the past two decades, solar- and astrophysicists and material scientists have been researching and developing new-generation semiconductor-based vacuum ultraviolet (VUV) detectors with low power consumption and small size for replacing traditional heavy and high-energy-consuming microchannel-detection systems, to study the formation and evolution of stars. However, the most desirable semiconductor-based VUV photovoltaic detector capable of achieving zero power consumption has not yet been achieved. With high-crystallinity multistep epitaxial grown AlN as a VUV-absorbing layer for photogenerated carriers and p-type graphene (with unexpected VUV transmittance >96%) as a transparent electrode to collect excited holes, we constructed a heterojunction device with photovoltaic detection for VUV light. The device exhibits an encouraging VUV photoresponse, high external quantum efficiency (EQE) and extremely fast tempera response (80 ns, 10 4 -10 6 times faster than that of the currently reported VUV photoconductive devices). This work has provided an idea for developing zero power consumption and integrated VUV photovoltaic detectors with ultrafast and high-sensitivity VUV detection capability, which not only allows future spacecraft to operate with longer service time and lower launching cost but also ensures an ultrafast evolution of interstellar objects.

THE INFLUENCE OF THE EXTREME ULTRAVIOLET SPECTRAL ENERGY DISTRIBUTION ON THE STRUCTURE AND COMPOSITION OF THE UPPER ATMOSPHERE OF EXOPLANETS

Energy Technology Data Exchange (ETDEWEB)

Guo, J. H. [Yunnan Observatories, Chinese Academy of Sciences, P.O. Box 110, Kunming 650011 (China); Ben-Jaffel, Lotfi, E-mail: guojh@ynao.ac.cn, E-mail: bjaffel@iap.fr [Sorbonne Universités, UPMC Univ. Paris 6 et CNRS, UMR 7095, Institut Astrophysique de Paris, F-75014 Paris (France)

2016-02-20

By varying the profiles of stellar extreme ultraviolet (EUV) spectral energy distributions (SEDs), we tested the influences of stellar EUV SEDs on the physical and chemical properties of an escaping atmosphere. We apply our model to study four exoplanets: HD 189733b, HD 209458b, GJ 436b, and Kepler-11b. We find that the total mass loss rates of an exoplanet, which are determined mainly by the integrated fluxes, are moderately affected by the profiles of the EUV SED, but the composition and species distributions in the atmosphere can be dramatically modified by the different profiles of the EUV SED. For exoplanets with a high hydrodynamic escape parameter (λ), the amount of atomic hydrogen produced by photoionization at different altitudes can vary by one to two orders of magnitude with the variation of stellar EUV SEDs. The effect of photoionization of H is prominent when the EUV SED is dominated by the low-energy spectral region (400–900 Å), which pushes the transition of H/H{sup +} to low altitudes. In contrast, the transition of H/H{sup +} moves to higher altitudes when most photons are concentrated in the high-energy spectral region (50–400 Å). For exoplanets with a low λ, the lower temperatures of the atmosphere make many chemical reactions so important that photoionization alone can no longer determine the composition of the escaping atmosphere. For HD 189733b, it is possible to explain the time variability of Lyα between 2010 and 2011 by a change in the EUV SED of the host K-type star, yet invoking only thermal H i in the atmosphere.

Inhibition of seagrass photosynthesis by ultraviolet-B radiation.

Science.gov (United States)

Trocine, R P; Rice, J D; Wells, G N

1981-07-01

Effects of ultraviolet-B radiation on the photosynthesis of seagrasses (Halophila engelmanni Aschers, Halodule wrightii Aschers, and Syringodium filiforme Kütz) were examined. The intrinsic tolerance of each seagrass to ultraviolet-B, the presence and effectiveness of photorepair mechanisms to ultraviolet-B-induced photosynthetic inhibition, and the role of epiphytic growth as a shield from ultraviolet-B were investigated.Halodule was found to possess the greatest photosynthetic tolerance for ultraviolet-B. Photosynthesis in Syringodium was slightly more sensitive to ultraviolet-B while Halophila showed relatively little photosynthetic tolerance. Evidence for a photorepair mechanism was found only in Halodule. This mechanism effectively attenuated photosynthetic inhibition induced by ultraviolet-B dose rates and dosages in excess of natural conditions. Syringodium appeared to rely primarily on a thick epidermal cell layer to reduce photosynthetic damage. Halophila seemed to have no morphological or photorepair capabilities to deal with ultraviolet-B. This species appeared to rely on epiphytic and detrital shielding and the shade provided by other seagrasses to reduce ultraviolet-B irradiation to tolerable levels. The presence of epiphytes on leaf surfaces was found to reduce the extent of photosynthetic inhibition from ultraviolet-B exposure in all species.Observations obtained in this study seem to suggest the possibility of anthocyanin and/or other flavonoid synthesis as an adaptation to long term ultraviolet-B irradiation by these species. In addition, Halophila appears to obtain an increased photosynthetic tolerance to ultraviolet-B as an indirect benefit of chloroplast clumping to avoid photo-oxidation by intense levels of photosynthetically active radiation.

Inhibition of seagrass photosynthesis by ultraviolet-B radiation

International Nuclear Information System (INIS)

Trocine, R.P.; Rice, J.D.; Wells, G.N.

1981-01-01

Effects of ultraviolet-B radiation on the photosynthesis of seagrasses (Halophila engelmanni Aschers, Halodule wrightii Aschers, and Syringodium filiforme (Kuetz) were examined. The intrinsic tolerance of each seagrass to ultraviolet-B, the presence and effectiveness of photorepair mechanisms to ultraviolet-B-induced photosynthetic inhibition, and the role of epiphytic growth as a shield from ultraviolet-B were investigated. Halodule was found to possess the greatest photosynthetic tolerance for ultraviolet-B. Photosynthesis in Syringodium was slightly more sensitive to ultraviolet-B while Halophila showed relatively little photosynthetic tolerance. Evidence for a photorepair mechanism was found only in Halodule. Syringodium appeared to rely primarily on a thick epidermal cell layer to reduce photosynthetic damage. Halophila seemed to have no morphological or photorepair capabilities to deal with ultraviolet-B. This species appeared to rely on epiphytic and detrital shielding and the shade provided by other seagrasses to reduce ultraviolet-B irradiation to tolerable levels. The presence of epiphytes on leaf surfaces was found to reduce the extent of photosynthetic inhibition from ultraviolet-B exposure in all species. Halophila appears to obtain an increased photosynthetic tolerance to ultraviolet-B as an indirect benefit of chloroplast clumping to avoid photo-oxidation by intense levels of photosynthetically active radiation

Harmful effects of ultraviolet radiation

International Nuclear Information System (INIS)

Anon.

1989-01-01

Tanning for cosmetic purposes by sunbathing or by using artificial tanning devices is widespread. The hazards associated with exposure to ultraviolet radiation are of concern to the medical profession. Depending on the amount and form of the radiation, as well as on the skin type of the individual exposed, ultraviolet radiation causes erythema, sunburn, photodamage (photoaging), photocarcinogenesis, damage to the eyes, alteration of the immune system of the skin, and chemical hypersensitivity. Skin cancers most commonly produced by ultraviolet radiation are basal and squamous cell carcinomas. There also is much circumstantial evidence that the increase in the incidence of cutaneous malignant melanoma during the past half century is related to increased sun exposure, but this has not been proved. Effective and cosmetically acceptable sunscreen preparations have been developed that can do much to prevent or reduce most harmful effects to ultraviolet radiation if they are applied properly and consistently. Other safety measures include (1) minimizing exposure to ultraviolet radiation, (2) being aware of reflective surfaces while in the sun, (3) wearing protective clothing, (4) avoiding use of artificial tanning devices, and (5) protecting infants and children

Berkeley lab checkpoint/restart (BLCR) for Linux clusters

International Nuclear Information System (INIS)

Hargrove, Paul H; Duell, Jason C

2006-01-01

This article describes the motivation, design and implementation of Berkeley Lab Checkpoint/Restart (BLCR), a system-level checkpoint/restart implementation for Linux clusters that targets the space of typical High Performance Computing applications, including MPI. Application-level solutions, including both checkpointing and fault-tolerant algorithms, are recognized as more time and space efficient than system-level checkpoints, which cannot make use of any application-specific knowledge. However, system-level checkpointing allows for preemption, making it suitable for responding to ''fault precursors'' (for instance, elevated error rates from ECC memory or network CRCs, or elevated temperature from sensors). Preemption can also increase the efficiency of batch scheduling; for instance reducing idle cycles (by allowing for shutdown without any queue draining period or reallocation of resources to eliminate idle nodes when better fitting jobs are queued), and reducing the average queued time (by limiting large jobs to running during off-peak hours, without the need to limit the length of such jobs). Each of these potential uses makes BLCR a valuable tool for efficient resource management in Linux clusters

Atise: a miniature Fourier-transform spectro-imaging concept for surveying auroras and airglow monitoring from a 6/12u cubesat

Science.gov (United States)

Le Courer, E.; Barthelemy, M.; Vialatte, A.; Prugniaux, M.; Bourdarot, G.; Sequies, T.; Monsinjon, P.; Puget, R.; Guerineau, N.

2017-09-01

The nanosatellite ATISE is a mission dedicated to the observation of the emission spectra of the upper atmosphere (i.e. Airglow and Auroras) mainly related to both the solar UV flux and the precipitation of suprathermal particles coming from the solar wind through the magnetosphere. ATISE will measure specifically the auroral emissions, and the airglow (day- and night) in the spectral range between 380 and 900 nm at altitudes between 100 and 350 km. The exposure time will be 1 second in auroral region and 20 s at low latitude regions. The 5 year expected lifetime of this mission should cover almost a half of solar cycle (2 years nominal). This instrument concept is based on an innovative miniaturized Fourier-transform spectrometer (FTS) allowing simultaneous 1 Rayleigh sensitivity detection along six 1.5°x1° limb lines of sight. This 1-2kg payload instrument is hosted in a 12U cubeSat where 6U are allocated to the payload and 6U to the plateform subsystems. This represents a miniaturisation by a factor of 500 on weight and volume compared to previous Arizona-GLO instrument for equivalent performances in the visible. The instrument is based on microSPOC concept developed by ONERA and IPAG using one Fizeau interferometer per line of sight directly glued on top of the half of a very sensitive CMOS Pyxalis HDPYX detector. Three detectors are necessary with a total electrical consumption compatible with a 6U nanoSat. Each interferometer occupies a 1.4 M pixel part of detector, each is placed on an image of the entrance pupil corresponding to a unique direction of the six lines of sight, this in order to have a uniform illumination permitting good spectral Fourier reconstruction from fringes created between the Fizeau plate and the detector itself. Despite a limited 8x6 cm telescope, this configuration takes advantage of FTS multiplex effect and permits us to maximize the throughput and to integrate very faint emission lines over a wide field of view even if the 1

Model simulations of line-of-sight effects in airglow imaging of acoustic and fast gravity waves from ground and space

Science.gov (United States)

Aguilar Guerrero, J.; Snively, J. B.

2017-12-01

Acoustic waves (AWs) have been predicted to be detectable by imaging systems for the OH airglow layer [Snively, GRL, 40, 2013], and have been identified in spectrometer data [Pilger et al., JASP, 104, 2013]. AWs are weak in the mesopause region, but can attain large amplitudes in the F region [Garcia et al., GRL, 40, 2013] and have local impacts on the thermosphere and ionosphere. Similarly, fast GWs, with phase speeds over 100 m/s, may propagate to the thermosphere and impart significant local body forcing [Vadas and Fritts, JASTP, 66, 2004]. Both have been clearly identified in ionospheric total electron content (TEC), such as following the 2013 Moore, OK, EF5 tornado [Nishioka et al., GRL, 40, 2013] and following the 2011 Tohoku-Oki tsunami [e.g., Galvan et al., RS, 47, 2012, and references therein], but AWs have yet to be unambiguously imaged in MLT data and fast GWs have low amplitudes near the threshold of detection; nevertheless, recent imaging systems have sufficient spatial and temporal resolution and sensitivity to detect both AWs and fast GWs with short periods [e.g., Pautet et al., AO, 53, 2014]. The associated detectability challenges are related to the transient nature of their signatures and to systematic challenges due to line-of-sight (LOS) effects such as enhancements and cancelations due to integration along aligned or oblique wavefronts and geometric intensity enhancements. We employ a simulated airglow imager framework that incorporates 2D and 3D emission rate data and performs the necessary LOS integrations for synthetic imaging from ground- and space-based platforms to assess relative intensity and temperature perturbations. We simulate acoustic and fast gravity wave perturbations to the hydroxyl layer from a nonlinear, compressible model [e.g., Snively, 2013] for different idealized and realistic test cases. The results show clear signal enhancements when acoustic waves are imaged off-zenith or off-nadir and the temporal evolution of these

Effect of ultraviolet exposure on mitochondrial respiratory system

Energy Technology Data Exchange (ETDEWEB)

Noda, K [Kurume Univ., Fukuoka (Japan). School of Medicine

1975-09-01

To find the photodynamic effect of ultraviolet light on the mitochondrial respiratory chain, mitochondria were obtained from rat livers, and the suspension was exposed to an extensive ultraviolet light. The oxygen consumption was measured polarographically with a Clark oxygen electrode. The effect of ultraviolet exposure on the five states of respiratory control (Chance and Williams), the P/O ratio, and the respiratory control index in mitochondria was discussed. The ultraviolet light with a dose of 9.6 x 10/sup 6/ erg/cm/sup 2/ caused the oxidative phosphorylation in mitochondria to uncouple. The 2nd phosphorylation site of the respiratory chain was susceptible to ultraviolet exposure. The stimulation of latent ATPase activity in mitochondria following exposure was observed by increasing exposure of ultraviolet light. However, DNP-stimulated ATPase was found to be stable in activity. The uncoupling of the respiratory chain by ultraviolet exposure was not detected if the mitochondrial suspension was preincubated with bovine serum albumin before exposure. The changes in light absorption of the mitochondrial suspension were followed at 520 nm after exposure. A close correlation was found between the ultraviolet exposure and swelling in mitochondria. But, the reversing contraction was observed by adding ATP to the swelled mitochondria. The peroxide compound was formed in mitochondria irradiated with ultraviolet light. The amount of compounds formed was dependent on the radiant energy of ultraviolet light. The possible mechanisms involved in the photodynamic effect of ultraviolet light to the mitochondrial respiration system were discussed.

SCR series switch and impulse crowbar at the Lawrence Berkeley Laboratory for CTR neutral beam source development

International Nuclear Information System (INIS)

Franck, J.V.; Arthur, A.A.; Brusse, L.A.; Low, W.

1977-10-01

The series switch is designed to operate at 120kV and pass 65A for 0.5 sec every 30 sec on the Lawrence Berkeley Laboratory CTR Neutral Beam Source Test Stand IIIB. The series switch consists of 400 individual SCR circuits connected in series and is turned on by a simple system of cascaded pulse transformers with multiple single turn secondaries each driving the individual SCR gates. It is turned off by an SCR impulse crowbar that momentarily shorts the power supply allowing the series switch to recover. The SCR switch has been tested in the impulse crowbar configuration and will reliably commutate up to 90A at 120kV. The series switch and impulse crowbar are now in service in Test Stand IIIB. A series switch and impulse crowbar similar in concept is routinely powering a 10 x 10 cm source at 150kV, 20A, 0.5 sec with a 1% duty cycle on the Lawrence Berkeley Laboratory CTR NSB Test Stand IIIA

Mutagenesis of Trichoderma Viride by Ultraviolet and Plasma

International Nuclear Information System (INIS)

Yao Risheng; Li Manman; Deng Shengsong; Hu Huajia; Wang Huai; Li Fenghe

2012-01-01

Considering the importance of a microbial strain capable of increased cellulase production, a mutant strain UP4 of Trichoderma viride was developed by ultraviolet (UV) and plasma mutation. The mutant produced a 21.0 IU/mL FPase which was 98.1% higher than that of the parent strain Trichoderma viride ZY-1. In addition, the effect of ultraviolet and plasma mutagenesis was not merely simple superimposition of single ultraviolet mutation and single plasma mutation. Meanwhile, there appeared a capsule around some of the spores after the ultraviolet and plasma treatment, namely, the spore surface of the strain became fuzzy after ultraviolet or ultraviolet and plasma mutagenesis.

Mutagenesis of Trichoderma Viride by Ultraviolet and Plasma

Science.gov (United States)

Yao, Risheng; Li, Manman; Deng, Shengsong; Hu, Huajia; Wang, Huai; Li, Fenghe

2012-04-01

Considering the importance of a microbial strain capable of increased cellulase production, a mutant strain UP4 of Trichoderma viride was developed by ultraviolet (UV) and plasma mutation. The mutant produced a 21.0 IU/mL FPase which was 98.1% higher than that of the parent strain Trichoderma viride ZY-1. In addition, the effect of ultraviolet and plasma mutagenesis was not merely simple superimposition of single ultraviolet mutation and single plasma mutation. Meanwhile, there appeared a capsule around some of the spores after the ultraviolet and plasma treatment, namely, the spore surface of the strain became fuzzy after ultraviolet or ultraviolet and plasma mutagenesis.

Public census data on CD-ROM at Lawrence Berkeley Laboratory. Revision 4

Energy Technology Data Exchange (ETDEWEB)

Merrill, D.W.

1993-03-12

The Comprehensive Epidemiologic Data Resource (CEDR) and Populations at Risk to Environmental Pollution (PAREP) projects, of the Information and Computing sciences Division (ICSD) at Lawrence Berkeley Laboratory (LBL), are using public socioeconomic and geographic data files which are available to CEDR and PAREP collaborators via LBL`s computing network. At this time 89 CD-ROM diskettes (approximately 45 gigabytes) are on line via the Unix file server cedrcd.lbl.gov. Most of the files are from the US Bureau of the Census, and many of these pertain to the 1990 Census of Population and Housing. All the CD-ROM diskettes contain documentation in the form of ASCII text files. In addition, printed documentation for most files is available for inspection at University of California Data and Technical Assistance (UC DATA), tel. (510) 642-6571, or the UC Documents Library, tel. (510) 642-2569, both located on the UC Berkeley Campus. Many of the CD-ROM diskettes distributed by the Census Bureau contain software for PC compatible computers, for easily accessing the data. Shared access to the data is maintained through a collaboration among the CEDR and PAREP projects at LBL, and UC DATA, and the UC Documents Library. LBL is grateful to UC DATA and the UC Documents Library for the use of their CD-ROM diskettes. Shared access to LBL facilities may be restricted in the future if costs become prohibitive. Via the Sun Network File System (NFS), these data can be exported to Internet computers for direct access by the user`s application program(s). Due to the size of the files, this access method is preferred over File Transfer Protocol (FTP) access.

Photodetector of ultra-violet radiation

International Nuclear Information System (INIS)

Dorogan, V.; Vieru, T.; Coseac, V.; Chirita, F.

1999-01-01

The invention relates to photodetectors on the semiconductors base, in particular, to photodetectors of ultra-violet radiation and can be used in the optoelectronics systems for determining the intensity and dose of ultraviolet radiation emitted by the Sun and other sources. In the structure of the photodetector of ultraviolet radiation with a superficial potential barrier formed of semiconductors A 3 B 5 with the prohibited power width Eg 1 , solid solutions thereof with the prohibited power width Eg 2 and SnO 2 or ITO, in the semiconductors A 3 B 5 at a surface distance less than the absorption length of the visible radiation it is formed an isotype heterojunction between the semiconductors A 3 B 5 and solid solutions thereof with the prohibited power width Eg 2 > Eg 1 . The technical result consists in manufacturing of a photodetector sensitive solely to the ultraviolet radiation

Public census data on CD-ROM at Lawrence Berkeley Laboratory. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Merrill, D.W.

1992-07-02

In connection with the Comprehensive Epidemiologic Data Resource (CEDR) and Populations at Risk to Environmental Pollution (PAREP) projects, of the Information and Computing Sciences Division (ICSD) at Lawrence Berkeley Laboratory (LBL), are using public socioeconomic and geographic data files which are available to CEDR and PAREP collaborators via LBL`s computing network. At this time 67 CD-ROM diskettes (approximately 35 gigabytes) are on line via the Unix file server cedrcd.lbl.gov. Most of the files are from the US Bureau of the Census, and most pertain to the 1990 Census of Population and Housing. This paper contains a list of the CD-ROMs available.

Decommissioning of fuel PIE caves at Berkeley Nuclear Laboratories

International Nuclear Information System (INIS)

Brant, A.W.

1990-01-01

This paper describes the first major contract awarded to private industry to carry out decommissioning of a facility with significant radiation levels. The work required operatives to work in pressurised suits, entry times were significantly affected by sources of radiation in the Caves, being as low as thirty minutes per day initially. The Caves at Berkeley Nuclear Laboratories carry out post irradiation examination of fuel elements support units and reactor core components from CEGB power stations. The decommissioning work is part of an overall refurbishment of the facility to allow the receipt of AGR Fuel Stringer Component direct from power stations. The paper describes the decommissioning and decontamination of the facility from the remote removal and clean up work carried out by the client to the hands-on work. It includes reference to entry times, work patterns, interfaces with the client and the operations of the laboratory. Details of a specially adapted size reduction method are given. (Author)

Ultraviolet light - nature's own disinfection process

Energy Technology Data Exchange (ETDEWEB)

Munkeberg, T [Thorolf Gregersen a/s, Oslo (Norway)

1978-05-18

Ultraviolet radiation from the sun is the means by which natural pollution products, as well as much of the smaller amount of pollution products produced by man, are converted and returned to the cycle of nature. Artificial ultraviolet radiation offers an optimum method for the disinfection of drinking water and can be used in the long term without undesireable effects on man or the enviromment. There is no evidence that ultraviolet irradiation leads to radiation resistant mutations of bacteria. The geometrical arrangement of ultraviolet disinfection units is described and the capacities of typical units is mentioned as being 600-800 m/sup 3/ /hr, though there is no reason why this should not be increased.

Ultraviolet light - nature's own disinfection process

International Nuclear Information System (INIS)

Munkeberg, T.

1978-01-01

Ultraviolet radiation from the sun is the means by which natural pollution products, as well as much of the smaller amount of pollution products produced by man, are converted and returned to the cycle of nature. Artificial ultraviolet radiation offers an optimum method for the disinfection of drinking water and can be used in the long term without undesireable effects on man or the enviromment. There is no evidence that ultraviolet irradiation leads to radiation resistant mutations of bacteria. The geometrical arrangement of ultraviolet disinfection units is described and the capacities of typical units is mentioned as being 600-800 m 3 /hr, though there is no reason why this should not be increased. (JIW)

CHROMOSPHERIC EVAPORATION IN AN M1.8 FLARE OBSERVED BY THE EXTREME-ULTRAVIOLET IMAGING SPECTROMETER ON HINODE

International Nuclear Information System (INIS)

Doschek, G. A.; Warren, H. P.; Young, P. R.

2013-01-01

We discuss observations of chromospheric evaporation for a complex flare that occurred on 2012 March 9 near 03:30 UT obtained from the Extreme-ultraviolet Imaging Spectrometer (EIS) on board the Hinode spacecraft. This was a multiple event with a strong energy input that reached the M1.8 class when observed by EIS. EIS was in raster mode and fortunately the slit was almost at the exact location of a significant energy input. Also, EIS obtained a full-CCD spectrum of the flare, i.e., the entire CCD was readout so that data were obtained for about the 500 lines identified in the EIS wavelength ranges. Chromospheric evaporation characterized by 150-200 km s –1 upflows was observed in multiple locations in multi-million degree spectral lines of flare ions such as Fe XXII, Fe XXIII, and Fe XXIV, with simultaneous 20-60 km s –1 upflows in million degree coronal lines from ions such as Fe XII-Fe XVI. The behavior of cooler, transition region ions such as O VI, Fe VIII, He II, and Fe X is more complex, but upflows were also observed in Fe VIII and Fe X lines. At a point close to strong energy input in space and time, the flare ions Fe XXII, Fe XXIII, and Fe XXIV reveal an isothermal source with a temperature close to 14 MK and no strong blueshifted components. At this location there is a strong downflow in cooler active region lines from ions such as Fe XIII and Fe XIV, on the order of 200 km s –1 . We speculate that this downflow may be evidence of the downward shock produced by reconnection in the current sheet seen in MHD simulations. A sunquake also occurred near this location. Electron densities were obtained from density sensitive lines ratios from Fe XIII and Fe XIV. Atmospheric Imaging Assembly (AIA) observations from the Solar Dynamics Observatory are used with JHelioviewer to obtain a qualitative overview of the flare. However, AIA data are not presented in this paper. In summary, spectroscopic data from EIS are presented that can be used for predictive

Chromospheric Evaporation in an M1.8 Flare Observed by the Extreme-ultraviolet Imaging Spectrometer on Hinode

Science.gov (United States)

Doschek, G. A.; Warren, H. P.; Young, P. R.

2013-04-01

We discuss observations of chromospheric evaporation for a complex flare that occurred on 2012 March 9 near 03:30 UT obtained from the Extreme-ultraviolet Imaging Spectrometer (EIS) on board the Hinode spacecraft. This was a multiple event with a strong energy input that reached the M1.8 class when observed by EIS. EIS was in raster mode and fortunately the slit was almost at the exact location of a significant energy input. Also, EIS obtained a full-CCD spectrum of the flare, i.e., the entire CCD was readout so that data were obtained for about the 500 lines identified in the EIS wavelength ranges. Chromospheric evaporation characterized by 150-200 km s-1 upflows was observed in multiple locations in multi-million degree spectral lines of flare ions such as Fe XXII, Fe XXIII, and Fe XXIV, with simultaneous 20-60 km s-1 upflows in million degree coronal lines from ions such as Fe XII-Fe XVI. The behavior of cooler, transition region ions such as O VI, Fe VIII, He II, and Fe X is more complex, but upflows were also observed in Fe VIII and Fe X lines. At a point close to strong energy input in space and time, the flare ions Fe XXII, Fe XXIII, and Fe XXIV reveal an isothermal source with a temperature close to 14 MK and no strong blueshifted components. At this location there is a strong downflow in cooler active region lines from ions such as Fe XIII and Fe XIV, on the order of 200 km s-1. We speculate that this downflow may be evidence of the downward shock produced by reconnection in the current sheet seen in MHD simulations. A sunquake also occurred near this location. Electron densities were obtained from density sensitive lines ratios from Fe XIII and Fe XIV. Atmospheric Imaging Assembly (AIA) observations from the Solar Dynamics Observatory are used with JHelioviewer to obtain a qualitative overview of the flare. However, AIA data are not presented in this paper. In summary, spectroscopic data from EIS are presented that can be used for predictive tests of

BERKELEY: Farewell to the Bevatron/Bevalac

International Nuclear Information System (INIS)

Anon.

1993-01-01

Full text: Nearly a hundred current and former Lawrence Berkeley Laboratory employees gathered at the Bevatron accelerator on 21 February to watch Ed Lofgren turn off the beam for the last time. Lofgren, in charge of the venerable machine from its completion in 1954 until his retirement in 1979, pushed a button that someone long ago labeled ''atom smasher offer'', bringing to an end four decades of accomplishment in high energy and heavy ion physics. Owen Chamberlain, who shared the 1959 physics Nobel with Emilio Segré for the discovery of the antiproton at the Bevatron, was among those present at the closing ceremony. The shutdown came 39 years to the week after Bevatron beam first circulated, and a touching moment came just after Lofgren shut the machine down when the poignant strains of the ''Taps'' salute wafted out over the PA system. The Bevatron - or Bevalac, as it was called after being linked to the Super HILAC linear accelerator in the 1970s - made major contributions in four distinct areas of research: high energy physics, heavy ion physics, medical research and therapy, and space-related studies of radiation damage and heavy particles in space. As well as the discovery of the antiproton, the early years of the Bevatron saw classic studies of the kaon, leading to a deeper understanding of both strong and weak interaction physics. With Luis Alvarez' development of Donald Glaser's original bubble chamber idea into a prolific physics technique, the Bevatron was a major focus of the heady days of resonance hunting in the late 1950s and early 1960s. Most recently the Bevalac (Bevatron-SuperHILAC combination) pioneered relativistic heavy ion physics. The central focus of this research programme was the production and study of extreme conditions in nuclear matter. Highlights include the first definitive evidence of collective flow of nuclear matter at high temperatures and densities, studies of the nuclear

Far-ultraviolet spectral changes of titanium dioxide with gold nanoparticles by ultraviolet and visible light

Science.gov (United States)

Tanabe, Ichiro; Kurawaki, Yuji

2018-05-01

Attenuated total reflectance spectra including the far-ultraviolet (FUV, ≤ 200 nm) region of titanium dioxide (TiO2) with and without gold (Au) nanoparticles were measured. A newly developed external light-irradiation system enabled to observe spectral changes of TiO2 with Au nanoparticles upon light irradiations. Absorption in the FUV region decreased and increased by the irradiation with ultraviolet and visible light, respectively. These spectral changes may reflect photo-induced electron transfer from TiO2 to Au nanoparticles under ultraviolet light and from Au nanoparticles to TiO2 under visible light, respectively.

Ultraviolet spectrophotometry of three LINERs

Science.gov (United States)

Goodrich, R. W.; Keel, W. C.

1986-01-01

Three galaxies known to be LINERs were observed spectroscopically in the ultraviolet in an attempt to detect the presumed nonthermal continuum source thought to be the source of photoionization in the nuclei. NGC 4501 was found to be too faint for study with the IUE spectrographs, while NGC 5005 had an extended ultraviolet light profile. Comparison with the optical light profile of NGC 5005 indicates that the ultraviolet source is distributed spatially in the same manner as the optical starlight, probably indicating that the ultraviolet excess is due to a component of hot stars in the nucleus. These stars contribute detectable absorption features longward of 2500 A; together with optical data, the IUE spectra suggest a burst of star formation about 1 billion yr ago, with a lower rate continuing to produce a few OB stars. In NGC 4579, a point source contributing most of the ultraviolet excess is found that is much different than the optical light distribution. Furthermore, the ultraviolet to X-ray spectral index in NGC 4579 is 1.4, compatible with the UV to X-ray indices found for samples of Seyfert galaxies. This provides compelling evidence for the detection of the photoionizing continuum in NGC 4579 and draws the research fields of normal galaxies and active galactic nuclei closer together. The emission-line spectrum of NGC 4579 is compared with calculations from a photoionization code, CLOUDY, and several shock models. The photoionization code is found to give superior results, adding to the increasing weight of evidence that the LINER phenomenon is essentially a scaled-down version of the Seyfert phenomenon.

Ultraviolet safety assessments of insect light traps.

Science.gov (United States)

Sliney, David H; Gilbert, David W; Lyon, Terry

2016-01-01

Near-ultraviolet (UV-A: 315-400 nm), "black-light," electric lamps were invented in 1935 and ultraviolet insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous ultraviolet emissions. A variety of UV "Black-light" ILTs were measured at a range of distances to assess potential exposures. Realistic time-weighted human exposures are shown to be well below current guidelines for human exposure to ultraviolet radiation. These UV-A exposures would be far less than the typical UV-A exposure in the outdoor environment. Proposals are made for realistic ultraviolet safety standards for ILT products.

Ultraviolet spectrophotometry of 2A 1822--371: A bulge on the accretion disk

International Nuclear Information System (INIS)

Mason, K.O.; Cordova, F.A.

1982-01-01

The X-ray source 2A 1822--371 has been observed with the IUE satellite over an 8 hour period. Long and short wavelength exposures of duration 45 or 60 minutes were alternated in order to resolve the 5.57 hr photometric modulation of the star. The data provide evidence that the shape of the 5.57 hr modulation evolves smoothly with energy between extremes defined by the optical and X-ray curves. The far-UV light curve is more deeply modulated than the X-ray light curve. The combined ultraviolet and the UBV band optical data can be fitted with a single blackbody of temperature 2.7 x 10 4 K, or an optically thick disk model with parameters T/sub asterisk/ = 1.2 x 10 5 K and R/sub out//R/sub in/approx.30. A single power-law model does not adequately represent the continuum. There is evidence of absorption due to the 2200 A interstellar feature whose depth requires a color excess, E(B--V)approx.0.1, with 3 sigma upper and lower bounds of 0.29 and 0.01. Emission lines of C IV 1550 A and N V 1240 A are detected in the UV spectrum. The work of Mason et al. and White et al. suggests that the optical and ultraviolet emission arises in an accretion disk, whereas the X-radiation is emitted from a scattering cloud that envelopes a central compact object. In the present paper, the 5.57 hr optical, X-ray and ultraviolet modulation of 2A 1822--371 is intrepreted as the result of partial occultation of the emitting region by a comparison star and a bulge on the outer accretion disk. X-ray heating of the bulge will probably also contribute to the modulation at optical and ultraviolet wavelengths

Public census data on CD-ROM at Lawrence Berkeley Laboratory. Revision 3

Energy Technology Data Exchange (ETDEWEB)

Merrill, D.W.

1993-01-16

The Comprehensive Epidemiologic Data Resource (CEDR) and Populations at Risk to Environmental Pollution (PAREP) projects, of the Information and Computing Sciences Division (ICSD) at Lawrence Berkeley Laboratory (LBL), are using public socioeconomic and geographic data files which are available to CEDR and PAREP collaborators via LBL`s computing network. At this time 72 CD-ROM diskettes (approximately 37 gigabytes) are on line via the Unix file server ``cedrcd.lbl.gov``. Most of the files are from the US Bureau of the Census, and many of these pertain to the 1990 Census of Population and Housing. All the CD-ROM diskettes contain documentation in the form of ASCII text files. In addition, printed documentation for most files is available for inspection at University of California Data and Technical Assistance (UC DATA), tel. (510) 642-6571, or the UC Documents Library, tel. (510) 642-2569, both located on the UC Berkeley Campus. Many of the CD-ROM diskettes distributed by the Census Bureau contain software for PC compatible computers, for easily accessing the data. Shared access to the data is maintained through a collaboration among the CEDR and PAREP projects at LBL, and UC DATA, and the UC Documents Library. LBL is grateful to UC DATA and the UC Documents Library for the use of their CD-ROM diskettes. Shared access to LBL facilities may be restricted in the future if costs become prohibitive. Via the Sun Network File System (NFS), these data can be exported to Internet computers for direct access by the user`s application program(s). Due to the size of the files, this access method is preferred over File Transfer Protocol (FTP) access. Please contact Deane Merrill (dwmerrill@lbl.gov) if you wish to make use of the data.

FAINT NEAR-ULTRAVIOLET/FAR-ULTRAVIOLET STANDARDS FROM SWIFT/UVOT, GALEX, AND SDSS PHOTOMETRY

International Nuclear Information System (INIS)

Siegel, Michael H.; Hoversten, Erik A.; Roming, Peter W. A.; Brown, Peter

2010-01-01

At present, the precision of deep ultraviolet photometry is somewhat limited by the dearth of faint ultraviolet standard stars. In an effort to improve this situation, we present a uniform catalog of 11 new faint (u ∼ 17) ultraviolet standard stars. High-precision photometry of these stars has been taken from the Sloan Digital Sky Survey and Galaxy Evolution Explorer archives and combined with new data from the Swift Ultraviolet Optical Telescope to provide precise photometric measures extending from the near-infrared to the far-ultraviolet. These stars were chosen because they are known to be hot (20, 000 eff < 50, 000 K) DA white dwarfs with published Sloan spectra that should be photometrically stable. This careful selection allows us to compare the combined photometry and Sloan spectroscopy to models of pure hydrogen atmospheres to both constrain the underlying properties of the white dwarfs and test the ability of white dwarf models to predict the photometric measures. We find that the photometry provides good constraints on white dwarf temperatures, which demonstrates the ability of Swift/UVOT to investigate the properties of hot luminous stars. We further find that the models reproduce the photometric measures in all 11 passbands to within their systematic uncertainties. Within the limits of our photometry, we find the standard stars to be photometrically stable. This success indicates that the models can be used to calibrate additional filters to our standard system, permitting easier comparison of photometry from heterogeneous sources. The largest source of uncertainty in the model fitting is the uncertainty in the foreground reddening curve, a problem that is especially acute in the UV.

Hubble Space Telescope Ultraviolet Spectroscopy of Fourteen Low-Redshift Quasars

DEFF Research Database (Denmark)

Ganguly, Rajib; Brotherton, Michael S.; Arav, Nahum

2007-01-01

We present low-resolution ultraviolet spectra of 14 low redshift (z zz 1.4 Large Bright Quasar samples. By design, our objects sample luminosities in between these two surveys, and our four absorbed objects are consistent with the v ~ L^0.62 relation derived by Laor & Brandt (2002). Another quasar......, HE0441-2826, contains extremely weak emission lines and our spectrum is consistent with a simple power-law continuum. The quasar is radio-loud, but has a steep spectral index and a lobe-dominated morphology, which argues against it being a blazar. The unusual spectrum of this quasar resembles...... the spectra of the quasars PG1407+265, SDSSJ1136+0242, and PKS1004+13 for which several possible explanations have been entertained....

Lawrence Berkeley National Laboratory 1995 site environmental report: Volume 2, Data appendix

International Nuclear Information System (INIS)

1996-07-01

Ernest Orlando Lawrence Berkeley National Laboratory presents Volume II, Data Appendix as a reference document to supplement the 1995 Site Environmental Report. Volume II contains the raw environmental monitoring and sampling data used to generate many of the summary results included in the main report. Supplemental data is provided for sitewide activities involving the media of stack and ambient air quality, rainwater, surface water, stormwater, wastewater, and soil and sediment. Volume II also contains supplemental data on the special preoperational monitoring study for the new Hazardous Waste Handling Facility. The Table of Contents provides a cross-reference to the data tables of the main report and this appendix. Data are given in System International (SI) units

AN INTRODUCTION TO EXPLORING LAW, DISABILITY, AND THE CHALLENGE OF EQUALITY IN CANADA AND THE UNITED STATES: PAPERS FROM THE BERKELEY SYMPOSIUM

Directory of Open Access Journals (Sweden)

Laverne Jacobs

2015-10-01

Full Text Available It brings me great pleasure to write this Introduction to Exploring Law, Disability, and the Challenge of Equality in Canada and the United States. This special collection of articles in the Windsor Yearbook of Access to Justice [WYAJ] stems from a symposium of the same name held at the Berkeley Law School at the University of California on 5 December 2014. Writing this introduction allows me to bring together my identities as a law and disability scholar, the principal organizer and convener of the Berkeley Symposium, and editor-in-chief of the WYAJ. In these roles, I have had the opportunity to engage with this set of articles and their authors in a distinct way – from the early versions of these articles through to the final peer-reviewed publications. The Berkeley Symposium is the first conference, of which we are aware, to bring together scholars and experts from both Canada and the United States to present research and exchange ideas on equality issues affecting persons with disabilities in both countries.1 Each academic was invited to write about an equality issue of their choice that is of contemporary concern to persons with disabilities, and to focus on Canada, the United States,or both, at their  option. The result is a set of articles that is simultaneously introspective and comparative.

Disinfection Effect of Film Cassettes by Ultraviolet Irradiation

International Nuclear Information System (INIS)

Kweon, Dae Cheol; Park, Peom

2001-01-01

A bacteria infection on film cassette contact surface was examined at the diagnostic radiology department. Studies have demonstrated a bactericidal effect of ultraviolet irradiation, and to assess the contamination level on film cassette contact surface as a predictor of patient prevent from nosocomial infection. The study showed that the laboratory result was identified non-pathologic and pathologic bacterial in the five different cassette size of the contact surface. Film cassettes were exposed to ultraviolet light for 1, 2 and 3 minutes. Ultraviolet light disinfection practices suitable for bacteria. The study concludes that presence of a bacterial infection will prevent a using antiseptic technique on film cassette contact surface. In conclusion, ultraviolet irradiate on film cassette over the surface more than 2 minutes. Ultraviolet dose of 1565 μW · s/cm 2 Win in 30 second relative to ultraviolet dose in time

Ultra-high accuracy optical testing: creating diffraction-limitedshort-wavelength optical systems

Energy Technology Data Exchange (ETDEWEB)

Goldberg, Kenneth A.; Naulleau, Patrick P.; Rekawa, Senajith B.; Denham, Paul E.; Liddle, J. Alexander; Gullikson, Eric M.; Jackson, KeithH.; Anderson, Erik H.; Taylor, John S.; Sommargren, Gary E.; Chapman,Henry N.; Phillion, Donald W.; Johnson, Michael; Barty, Anton; Soufli,Regina; Spiller, Eberhard A.; Walton, Christopher C.; Bajt, Sasa

2005-08-03

Since 1993, research in the fabrication of extreme ultraviolet (EUV) optical imaging systems, conducted at Lawrence Berkeley National Laboratory (LBNL) and Lawrence Livermore National Laboratory (LLNL), has produced the highest resolution optical systems ever made. We have pioneered the development of ultra-high-accuracy optical testing and alignment methods, working at extreme ultraviolet wavelengths, and pushing wavefront-measuring interferometry into the 2-20-nm wavelength range (60-600 eV). These coherent measurement techniques, including lateral shearing interferometry and phase-shifting point-diffraction interferometry (PS/PDI) have achieved RMS wavefront measurement accuracies of 0.5-1-{angstrom} and better for primary aberration terms, enabling the creation of diffraction-limited EUV optics. The measurement accuracy is established using careful null-testing procedures, and has been verified repeatedly through high-resolution imaging. We believe these methods are broadly applicable to the advancement of short-wavelength optical systems including space telescopes, microscope objectives, projection lenses, synchrotron beamline optics, diffractive and holographic optics, and more. Measurements have been performed on a tunable undulator beamline at LBNL's Advanced Light Source (ALS), optimized for high coherent flux; although many of these techniques should be adaptable to alternative ultraviolet, EUV, and soft x-ray light sources. To date, we have measured nine prototype all-reflective EUV optical systems with NA values between 0.08 and 0.30 (f/6.25 to f/1.67). These projection-imaging lenses were created for the semiconductor industry's advanced research in EUV photolithography, a technology slated for introduction in 2009-13. This paper reviews the methods used and our program's accomplishments to date.

Advanced 0.3-NA EUV lithography capabilities at the ALS

International Nuclear Information System (INIS)

Naulleau, Patrick; Anderson, Erik; Dean, Kim; Denham, Paul; Goldberg, Kenneth A.; Hoef, Brian; Jackson, Keith

2005-01-01

For volume nanoelectronics production using Extreme ultraviolet (EUV) lithography [1] to become a reality around the year 2011, advanced EUV research tools are required today. Microfield exposure tools have played a vital role in the early development of EUV lithography [2-4] concentrating on numerical apertures (NA) of 0.2 and smaller. Expected to enter production at the 32-nm node with NAs of 0.25, EUV can no longer rely on these early research tools to provide relevant learning. To overcome this problem, a new generation of microfield exposure tools, operating at an NA of 0.3 have been developed [5-8]. Like their predecessors, these tools trade off field size and speed for greatly reduced complexity. One of these tools is implemented at Lawrence Berkeley National Laboratory's Advanced Light Source synchrotron radiation facility. This tool gets around the problem of the intrinsically high coherence of the synchrotron source [9,10] by using an active illuminator scheme [11]. Here we describe recent printing results obtained from the Berkeley EUV exposure tool. Limited by the availability of ultra-high resolution chemically amplified resists, present resolution limits are approximately 32 nm for equal lines and spaces and 27 nm for semi-isolated lines

Impact of ultraviolet radiation on humans

International Nuclear Information System (INIS)

Cesarini, J.P.

2001-01-01

Solar radiation, including its ultraviolet (UV) components is a key factor in life on Earth. While small quantities of UV are beneficial for people (for example, through the production of vitamin D), the considerable amount to which people sometimes expose themselves may have extremely noxious effects including actinic erythema, sunburn, photo-induced diseases, photo-worsened diseases, actinic ageing and skin cancers. Since the last century, human exposure to UV has increased either by social-behaviour modifications, or by anthropogenic disruption to the environment through, among other things, industrial development. The World Health Organisation's (WHO) INTERSUN programme has several components: action for reconstruction of the ozone layer through, for example, preventing dumping of chlorofluorocarbons; creation and popularisation of a global UV index; prevention campaigns underlining the risks from UV exposure including dissemination of information to daily newspapers. These are all aimed at reducing the amount of UV radiation that people receive. In addition the WHO advises against exposure to UV artificial sources to reduce overall the quantity of UV received. (author)

Impact of ultraviolet radiation on humans

Energy Technology Data Exchange (ETDEWEB)

Cesarini, J.P. [Laboratoire de Recherche sur les Tumeurs de la Peau Humaine, INSERM, Paris (France)

2001-07-01

Solar radiation, including its ultraviolet (UV) components is a key factor in life on Earth. While small quantities of UV are beneficial for people (for example, through the production of vitamin D), the considerable amount to which people sometimes expose themselves may have extremely noxious effects including actinic erythema, sunburn, photo-induced diseases, photo-worsened diseases, actinic ageing and skin cancers. Since the last century, human exposure to UV has increased either by social-behaviour modifications, or by anthropogenic disruption to the environment through, among other things, industrial development. The World Health Organisation's (WHO) INTERSUN programme has several components: action for reconstruction of the ozone layer through, for example, preventing dumping of chlorofluorocarbons; creation and popularisation of a global UV index; prevention campaigns underlining the risks from UV exposure including dissemination of information to daily newspapers. These are all aimed at reducing the amount of UV radiation that people receive. In addition the WHO advises against exposure to UV artificial sources to reduce overall the quantity of UV received. (author)

A fast-time-response extreme ultraviolet spectrometer for measurement of impurity line emissions in the Experimental Advanced Superconducting Tokamak

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ling; Xu, Zong; Wu, Zhenwei; Zhang, Pengfei; Wu, Chengrui; Gao, Wei; Shen, Junsong; Chen, Yingjie; Liu, Xiang; Wang, Yumin; Gong, Xianzu; Hu, Liqun; Chen, Junlin; Zhang, Xiaodong; Wan, Baonian; Li, Jiangang [Institute of Plasma Physics Chinese Academy of Sciences, Hefei 230026, Anhui (China); Morita, Shigeru; Ohishi, Tetsutarou; Goto, Motoshi [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Department of Fusion Science, Graduate University for Advanced Studies, Toki 509-5292, Gifu (Japan); Dong, Chunfeng [Southwestern Institute of Physics, Chengdu 610041, Sichuan (China); and others

2015-12-15

A flat-field extreme ultraviolet (EUV) spectrometer working in the 20-500 Å wavelength range with fast time response has been newly developed to measure line emissions from highly ionized tungsten in the Experimental Advanced Superconducting Tokamak (EAST) with a tungsten divertor, while the monitoring of light and medium impurities is also an aim in the present development. A flat-field focal plane for spectral image detection is made by a laminar-type varied-line-spacing concave holographic grating with an angle of incidence of 87°. A back-illuminated charge-coupled device (CCD) with a total size of 26.6 × 6.6 mm{sup 2} and pixel numbers of 1024 × 255 (26 × 26 μm{sup 2}/pixel) is used for recording the focal image of spectral lines. An excellent spectral resolution of Δλ{sub 0} = 3-4 pixels, where Δλ{sub 0} is defined as full width at the foot position of a spectral line, is obtained at the 80-400 Å wavelength range after careful adjustment of the grating and CCD positions. The high signal readout rate of the CCD can improve the temporal resolution of time-resolved spectra when the CCD is operated in the full vertical binning mode. It is usually operated at 5 ms per frame. If the vertical size of the CCD is reduced with a narrow slit, the time response becomes faster. The high-time response in the spectral measurement therefore makes possible a variety of spectroscopic studies, e.g., impurity behavior in long pulse discharges with edge-localized mode bursts. An absolute intensity calibration of the EUV spectrometer is also carried out with a technique using the EUV bremsstrahlung continuum at 20-150 Å for quantitative data analysis. Thus, the high-time resolution tungsten spectra have been successfully observed with good spectral resolution using the present EUV spectrometer system. Typical tungsten spectra in the EUV wavelength range observed from EAST discharges are presented with absolute intensity and spectral identification.

Ultraviolet Spectroscopy of Asteroid(4) Vesta

Science.gov (United States)

Li, Jian-Yang; Bodewits, Dennis; Feaga, Lori M.; Landsman, Wayne; A'Hearn, Michael F.; Mutchler, Max J.; Russell, Christopher T.; McFadden, Lucy A.; Raymond, Carol A.

2011-01-01

We report a comprehensive review of the UV-visible spectrum and rotational lightcurve of Vesta combining new observations by Hubble Space Telescope and Swift with archival International Ultraviolet Explorer observations. The geometric albedos of Vesta from 220 nm to 953 nm arc derived by carefully comparing these observations from various instruments at different times and observing geometries. Vesta has a rotationally averaged geometric albedo of 0.09 at 250 nm, 0.14 at 300 nm, 0.26 at 373 nm, 0.38 at 673 nm, and 0.30 at 950 nm. The linear spectral slope in the ultraviolet displays a sharp minimum ncar sub-Earth longitude of 20deg, and maximum in the eastern hemisphere. This is completely consistent with the distribution of the spectral slope in the visible wavelength. The uncertainty of the measurement in the ultraviolet is approx.20%, and in the visible wavelengths better than 10%. The amplitude of Vesta's rotational lightcurves is approx.10% throughout the range of wavelengths we observed, but is smaller at 950 nm (approx.6%) ncar the 1-micron mafic band center. Contrary to earlier reports, we found no evidence for any difference between the phasing of the ultraviolet and visible/ncar-infrared lightcurves with respect to sub-Earth longitude. Vesta's average spectrum between 220 and 950 nm can well be described by measured reflectance spectra of fine particle howardite-like materials of basaltic achondrite meteorites. Combining this with the in-phase behavior of the ultraviolet, visible. and ncar-infrared lightcurves, and the spectral slopes with respect to the rotational phase, we conclude that there is no global ultraviolet/visible reversal on Vesta. Consequently, this implies lack of global space weathering on Vesta. Keyword,: Asteroid Vesta; Spectrophotometry; Spectroscopy; Ultraviolet observations; Hubble Space Telescope observations

Resistance of Microorganisms to Extreme Environmental Conditions and Its Contribution to Astrobiology

Directory of Open Access Journals (Sweden)

Pabulo Henrique Rampelotto

2010-06-01

Full Text Available In the last decades, substantial changes have occurred regarding what scientists consider the limits of habitable environmental conditions. For every extreme environmental condition investigated, a variety of microorganisms have shown that not only can they tolerate these conditions, but that they also often require these extreme conditions for survival. Microbes can return to life even after hundreds of millions of years. Furthermore, a variety of studies demonstrate that microorganisms can survive under extreme conditions, such as ultracentrifugation, hypervelocity, shock pressure, high temperature variations, vacuums, and different ultraviolet and ionizing radiation intensities, which simulate the conditions that microbes could experience during the ejection from one planet, the journey through space, as well as the impact in another planet. With these discoveries, our knowledge about the biosphere has grown and the putative boundaries of life have expanded. The present work examines the recent discoveries and the principal advances concerning the resistance of microorganisms to extreme environmental conditions, and analyzes its contributions to the development of the main themes of astrobiology: the origins of life, the search for extraterrestrial life, and the dispersion of life in the Universe.