WorldWideScience

Sample records for solar spectroscopic measurements

  1. Spectroscopic Measurements of the Ion Velocity Distribution at the Base of the Fast Solar Wind

    Science.gov (United States)

    Jeffrey, Natasha L. S.; Hahn, Michael; Savin, Daniel W.; Fletcher, Lyndsay

    2018-03-01

    In situ measurements of the fast solar wind reveal non-thermal distributions of electrons, protons, and minor ions extending from 0.3 au to the heliopause. The physical mechanisms responsible for these non-thermal properties and the location where these properties originate remain open questions. Here, we present spectroscopic evidence, from extreme ultraviolet spectroscopy, that the velocity distribution functions (VDFs) of minor ions are already non-Gaussian at the base of the fast solar wind in a coronal hole, at altitudes of thermal equilibrium, (b) fluid motions such as non-Gaussian turbulent fluctuations or non-uniform wave motions, or (c) some combination of both. These observations provide important empirical constraints for the source region of the fast solar wind and for the theoretical models of the different acceleration, heating, and energy deposition processes therein. To the best of our knowledge, this is the first time that the ion VDF in the fast solar wind has been probed so close to its source region. The findings are also a timely precursor to the upcoming 2018 launch of the Parker Solar Probe, which will provide the closest in situ measurements of the solar wind at approximately 0.04 au (8.5 solar radii).

  2. Hard X-Ray Flare Source Sizes Measured with the Ramaty High Energy Solar Spectroscopic Imager

    Science.gov (United States)

    Dennis, Brian R.; Pernak, Rick L.

    2009-01-01

    Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations of 18 double hard X-ray sources seen at energies above 25 keV are analyzed to determine the spatial extent of the most compact structures evident in each case. The following four image reconstruction algorithms were used: Clean, Pixon, and two routines using visibilities maximum entropy and forward fit (VFF). All have been adapted for this study to optimize their ability to provide reliable estimates of the sizes of the more compact sources. The source fluxes, sizes, and morphologies obtained with each method are cross-correlated and the similarities and disagreements are discussed. The full width at half-maximum (FWHM) of the major axes of the sources with assumed elliptical Gaussian shapes are generally well correlated between the four image reconstruction routines and vary between the RHESSI resolution limit of approximately 2" up to approximately 20" with most below 10". The FWHM of the minor axes are generally at or just above the RHESSI limit and hence should be considered as unresolved in most cases. The orientation angles of the elliptical sources are also well correlated. These results suggest that the elongated sources are generally aligned along a flare ribbon with the minor axis perpendicular to the ribbon. This is verified for the one flare in our list with coincident Transition Region and Coronal Explorer (TRACE) images. There is evidence for significant extra flux in many of the flares in addition to the two identified compact sources, thus rendering the VFF assumption of just two Gaussians inadequate. A more realistic approximation in many cases would be of two line sources with unresolved widths. Recommendations are given for optimizing the RHESSI imaging reconstruction process to ensure that the finest possible details of the source morphology become evident and that reliable estimates can be made of the source dimensions.

  3. The convective noise floor for the spectroscopic detection of low mass companions to solar type stars

    Science.gov (United States)

    Deming, D.; Espenak, F.; Jennings, D. E.; Brault, J. W.

    1986-01-01

    The threshold mass for the unambiguous spectroscopic detection of low mass companions to solar type stars is defined here as the time when the maximum acceleration in the stellar radial velocity due to the Doppler reflex of the companion exceeds the apparent acceleration produced by changes in convection. An apparent acceleration of 11 m/s/yr in integrated sunlight was measured using near infrared Fourier transform spectroscopy. This drift in the apparent solar velocity is attributed to a lessening in the magnetic inhibition of granular convection as solar minimum approaches. The threshold mass for spectroscopic detection of companions to a one solar mass star is estimated at below one Jupiter mass.

  4. A SOLAR SPECTROSCOPIC ABSOLUTE ABUNDANCE OF ARGON FROM RESIK

    International Nuclear Information System (INIS)

    Sylwester, J.; Sylwester, B.; Phillips, K. J. H.; Kuznetsov, V. D.

    2010-01-01

    Observations of He-like and H-like Ar (Ar XVII and Ar XVIII) lines at 3.949 A and 3.733 A, respectively, with the RESIK X-ray spectrometer on the CORONAS-F spacecraft, together with temperatures and emission measures from the two channels of GOES, have been analyzed to obtain the abundance of Ar in flare plasmas in the solar corona. The line fluxes per unit emission measure show a temperature dependence like that predicted from theory and lead to spectroscopically determined values for the absolute Ar abundance, A(Ar) = 6.44 ± 0.07 (Ar XVII) and 6.49 ± 0.16 (Ar XVIII), which are in agreement to within uncertainties. The weighted mean is 6.45 ± 0.06, which is between two recent compilations of the solar Ar abundance and suggests that the photospheric and coronal abundances of Ar are very similar.

  5. Highlights of the Brazilian Solar Spectroscope

    Czech Academy of Sciences Publication Activity Database

    Sawant, H. S.; Cecatto, J.R.; Mészárosová, Hana; Faria, C.; Fernandes, F. C. R.; Karlický, Marian; de Andrade, M. C.

    2009-01-01

    Roč. 44, č. 1 (2009), s. 54-57 ISSN 0273-1177 R&D Projects: GA AV ČR IAA300030701 Institutional research plan: CEZ:AV0Z10030501 Keywords : Sun istrumentation * spectroscope * corona * radio radiation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.079, year: 2009

  6. Solar Flares and the High Energy Solar Spectroscopic Imager (HESSI)

    Science.gov (United States)

    Holman, Gordon D.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Solar flares are the biggest explosions in the solar system. They are important both for understanding explosive events in the Universe and for their impact on human technology and communications. The satellite-based HESSI is designed to study the explosive release of energy and the acceleration of electrons, protons, and other charged particles to high energies in solar flares. HESSI produces "color" movies of the Sun in high-energy X rays and gamma rays radiated by these energetic particles. HESSI's X-ray and gamma-ray images of flares are obtained using techniques similar to those used in radio interferometry. Ground-based radio observations of the Sun provide an important complement to the HESSI observations of solar flares. I will describe the HESSI Project and the high-energy aspects of solar flares, and how these relate to radio astronomy techniques and observations.

  7. Spectroscopic diagnostics and measurements at Jet

    International Nuclear Information System (INIS)

    Giannella, R.

    1994-01-01

    A concise review is presented of activity in the field spectroscopic diagnostic at JET during the latest few years. Together with a description of instruments, examples are given of the measurements conducted with these systems and some experimental result obtained with such activity are outlined. Emphasis is also given to the upgrading of existing apparatuses and the construction of new diagnostics ahead of the next experimental phase. 48 refs., 5 figs

  8. Automated reliability assessment for spectroscopic redshift measurements

    Science.gov (United States)

    Jamal, S.; Le Brun, V.; Le Fèvre, O.; Vibert, D.; Schmitt, A.; Surace, C.; Copin, Y.; Garilli, B.; Moresco, M.; Pozzetti, L.

    2018-03-01

    Context. Future large-scale surveys, such as the ESA Euclid mission, will produce a large set of galaxy redshifts (≥106) that will require fully automated data-processing pipelines to analyze the data, extract crucial information and ensure that all requirements are met. A fundamental element in these pipelines is to associate to each galaxy redshift measurement a quality, or reliability, estimate. Aim. In this work, we introduce a new approach to automate the spectroscopic redshift reliability assessment based on machine learning (ML) and characteristics of the redshift probability density function. Methods: We propose to rephrase the spectroscopic redshift estimation into a Bayesian framework, in order to incorporate all sources of information and uncertainties related to the redshift estimation process and produce a redshift posterior probability density function (PDF). To automate the assessment of a reliability flag, we exploit key features in the redshift posterior PDF and machine learning algorithms. Results: As a working example, public data from the VIMOS VLT Deep Survey is exploited to present and test this new methodology. We first tried to reproduce the existing reliability flags using supervised classification in order to describe different types of redshift PDFs, but due to the subjective definition of these flags (classification accuracy 58%), we soon opted for a new homogeneous partitioning of the data into distinct clusters via unsupervised classification. After assessing the accuracy of the new clusters via resubstitution and test predictions (classification accuracy 98%), we projected unlabeled data from preliminary mock simulations for the Euclid space mission into this mapping to predict their redshift reliability labels. Conclusions: Through the development of a methodology in which a system can build its own experience to assess the quality of a parameter, we are able to set a preliminary basis of an automated reliability assessment for

  9. Solar cell efficiency measurements

    International Nuclear Information System (INIS)

    Ostoja, P.

    1989-01-01

    Solar cells (and solar modules) have to be tested for their performance by means of sound reliable measurement procedures. The need for such measurements arises at various stages of research, of production, and of photovoltaic systems sizing and dimensioning. In fact, accurate measurements are necessary to the researcher, who studies new materials and new processes, to the manufacturer, who has to control his product and, finally, to the user, who needs sound measurements, in order to be in a position to make effective decisions about what kink of product will be needed and with what critical characteristics. In short, standard measurements that allow cells and modules to be characterized serve as a common language, allowing effective communication about products and requirements. 3 refs

  10. Infrared Solar Spectroscopic Measurements of Free Tropospheric CO, C2H6, and HCN above Mauna Loa, Hawaii: Seasonal Variations and Evidence for Enhanced Emissions from the Southeast Asian Tropical Fires of 1997-1998

    Science.gov (United States)

    Rinsland, C. P.; Goldman, A.; Murcray, F. J.; Stephen, T. M.; Pougatchev, N. S.; Fishman, J.; David, S. J.; Blatherwick, R. D.; Novelli, P. C.; Jones, N. B.

    1999-01-01

    High spectral resolution (0.003 per cm) infrared solar absorption measurements of CO, C2H6, and HCN have been recorded at the Network for the Detection of Stratospheric Change station on Mauna Loa, Hawaii, (19.5N, 155.6W, altitude 3.4 km). The observations were obtained on over 250 days between August 1995 and February 1998. Column measurements are reported for the 3.4-16 km altitude region, which corresponds approximately to the free troposphere above the station. Average CO mixing ratios computed for this layer have been compared with flask sampling CO measurements obtained in situ at the station during the same time period. Both show asymmetrical seasonal cycles superimposed on significant variability. The first 2 years of observations exhibit a broad January-April maximum and a sharper CO minimum during late summer. The C2H6 and CO 3.4-16 km columns were highly correlated throughout the observing period with the C2H6/CO slope intermediate between higher and lower values derived from similar infrared spectroscopic measurements at 32'N and 45'S latitude, respectively. Variable enhancements in CO, C2H6, and particularly HCN were observed beginning in about September 1997. The maximum HCN free tropospheric monthly mean column observed in November 1997 corresponds to an average 3.4-16 km mixing ratio of 0.7 ppbv (1 ppbv = 10(exp -9) per unit volume), more than a factor of 3 above the background level. The HCN enhancements continued through the end of the observational series. Back-trajectory calculations suggest that the emissions originated at low northern latitudes in southeast Asia. Surface CO mixing ratios and the C2H6 tropospheric columns measured during the same time also showed anomalous autumn 1997 maxima. The intense and widespread tropical wild fires that burned during the strong El Nino warm phase of 1997- 1998 are the likely source of the elevated emission products.

  11. Imaging and spectroscopic observations of the 9 March 2016 Total Solar Eclipse in Palangkaraya

    International Nuclear Information System (INIS)

    Kholish, Abdul Majid Al; Jihad, Imanul; Andika, Irham Taufik; Puspitaningrum, Evaria; Ainy, Fathin Q.; Ramadhan, Sahlan; Arifyanto, M. Ikbal; Malasan, Hakim L.

    2016-01-01

    The March 9 th 2016 total solar eclipse observation was carried out at Universitas Palangkaraya, Central Kalimantan. Time-resolved imaging of the Sun has been conducted before, after, and during totality of eclipse while optical spectroscopic observation has been carried out only at the totality. The imaging observation in white light was done to take high resolution images of solar corona. The images were taken with a DSLR camera that is attached to a refractor telescope (d=66 mm, f/5.9). Despite cloudy weather during the eclipse moments, we managed to obtain the images with lower signal-to-noise ratio, including identifiable diamond ring, prominence and coronal structure. The images were processed using standard reduction procedure to increase the signal-to-noise ratio and to enhance the corona. Then, the coronal structure is determined and compared with ultraviolet data from SOHO to analyze the correlation between visual and ultraviolet corona. The spectroscopic observation was conducted using a slit-less spectrograph and a DSLR camera to obtain solar flash spectra. The flash spectra taken during the eclipse show emissions of H 4861 Å, He I 5876 Å, and H 6563 Å. The Fe XIV 5303 Å and Fe X 6374 Å lines are hardly detected due to low signal-to-noise ratio. Spectral reduction and analysis are conducted to derive the emission lines intensity relative to continuum intensity. We use the measured parameters to determine the temperature of solar chromosphere. (paper)

  12. High Energy Solar Spectroscopic Imager (HESSI) Team Investigations

    Science.gov (United States)

    Emslie, A. Gordon

    1998-01-01

    This report covers activities on the above grant for the period through the end of September 1997. The work originally proposed to be performed under a three-year award was converted at that time to a two-year award for the remainder of the period, and is now funded under award NAGS-4027 through Goddard Space Flight Center. The P.I. is a co-investigator on the High Energy Solar Spectroscopic Imager (HESSI) team, selected as a Small-Class Explorer (SNMX) mission in 1997. He has also been a participant in the Space Physics Roadmap Planning Group. Our research has been strongly influenced by the NASA mission opportunities related to these activities. The report is subdivided into four sections, each dealing with a different aspect of our research within this guiding theme. Personnel involved in this research at UAH include the P.I. and graduate students Michele Montgomery and Amy Winebarger. Much of the work has been carried out in collaboration with investigators at other institutions, as detailed below. Attachment: Laser wakefield acceleration and astrophysical applications.

  13. Solar Flares Observed with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI)

    Science.gov (United States)

    Holman, Gordon D.

    2004-01-01

    Solar flares are impressive examples of explosive energy release in unconfined, magnetized plasma. It is generally believed that the flare energy is derived from the coronal magnetic field. However, we have not been able to establish the specific energy release mechanism(s) or the relative partitioning of the released energy between heating, particle acceleration (electrons and ions), and mass motions. NASA's RHESSI Mission was designed to study the acceleration and evolution of electrons and ions in flares by observing the X-ray and gamma-ray emissions these energetic particles produce. This is accomplished through the combination of high-resolution spectroscopy and spectroscopic imaging, including the first images of flares in gamma rays. RHESSI has observed over 12,000 solar flares since its launch on February 5, 2002. I will demonstrate how we use the RHESSI spectra to deduce physical properties of accelerated electrons and hot plasma in flares. Using images to estimate volumes, w e typically find that the total energy in accelerated electrons is comparable to that in the thermal plasma. I will also present flare observations that provide strong support for the presence of magnetic reconnection in a large-scale, vertical current sheet in the solar corona. RHESSI observations such as these are allowing us to probe more deeply into the physics of solar flares.

  14. Seismological measurement of solar helium abundance

    International Nuclear Information System (INIS)

    Vorontsov, S.V.; Pamyatnykh, A.A.

    1991-01-01

    The internal structure and evolution of the Sun depends on its chemical composition, particularly the helium abundance. In addition, the helium abundance in the solar envelope is thought to represent the protosolar value, making it a datum of cosmological significance. Spectroscopic measurements of the helium abundance are uncertain, and the most reliable estimates until now have come from the calibration of solar evolutionary models. The frequencies of solar acoustic oscillations are sensitive, however, to the behaviour of the speed of sound in the Sun's helium ionization zone, which allows a helioseismological determination of the helium abundance. Sound-speed inversion of helioseismological data can be used for this purpose, but precise frequency measurements of high-degree oscillation modes are needed. Here we describe a new approach based on an analysis of the phase shift of acoustic waves of intermediate-degree modes. From the accurate intermediate-mode data now available, we obtain a helium mass fraction Y=0.25±0.01 in the solar convection zone, significantly smaller than the value Y=0.27-0.29 predicted by recent solar evolutionary models. The discrepancy indicates either that initial helium abundance was reduced in the envelope by downward diffusion or that the protosolar value was lower than currently accepted. (author)

  15. Proposed geological solar neutrino measurement

    International Nuclear Information System (INIS)

    Cowan, G.A.; Haxton, W.C.

    1982-01-01

    It may be possible to measure the boron-8 solar neutrino flux, averaged over the past several million years, from the concentration of technetium-98 in molybdenum-rich ore. This geochemical experiment could provide the first test of nonstandard solar models that suggest a relation between the chlorine-37 solar neutrino puzzle and the most recent glacial epoch. The necessary conditions for achieving a meaningful measurement are identified and discussed

  16. Solar Energy Measurement Using Arduino

    OpenAIRE

    Jumaat Siti Amely; Othman Mohamad Hilmi

    2018-01-01

    This project aims to develop a measurement of solar energy using Arduino Board technology. In this research, four parameters that been measured are temperature, light intensity, voltage and current. The temperature was measured using temperature sensor. The light intensity was measured using light dependent resistor (LDR) sensor. The voltage was measured using the voltage divider because the voltage generated by the solar panel are large for the Arduino as receiver. Lastly for the current was...

  17. Spectroscopic technique for measuring atmospheric CO2

    International Nuclear Information System (INIS)

    Stokes, G.M.; Stokes, R.A.

    1979-01-01

    As part of a continuing effort to identify areas in which astronomical techniques and data may be profitably applied to atmospheric problems, both new and archival solar spectra have been collected to prepare for an analysis of their use for studying the changes of the atmospheric CO 2 burden. This analysis has resulted in the initiation of an observing program using the Fourier Transform Spectrometer (FTS) of the McMath Solar Telescope at Kitt Peak National Observatory (KPNO). This program is generating spectra, the quality of which should not only aid the archival CO 2 study but also lead to analyses of other trace gases

  18. Solar and infrared radiation measurements

    CERN Document Server

    Vignola, Frank; Michalsky, Joseph

    2012-01-01

    The rather specialized field of solar and infrared radiation measurement has become more and more important in the face of growing demands by the renewable energy and climate change research communities for data that are more accurate and have increased temporal and spatial resolution. Updating decades of acquired knowledge in the field, Solar and Infrared Radiation Measurements details the strengths and weaknesses of instruments used to conduct such solar and infrared radiation measurements. Topics covered include: Radiometer design and performance Equipment calibration, installation, operati

  19. Solar Measurement and Modeling | Grid Modernization | NREL

    Science.gov (United States)

    Measurement and Modeling Solar Measurement and Modeling NREL supports grid integration studies , industry, government, and academia by disseminating solar resource measurements, models, and best practices have continuously gathered basic solar radiation information, and they now gather high-resolution data

  20. Spectroscopic analysis applied to temperature measurement in plasmas

    International Nuclear Information System (INIS)

    Fieffe-Prevost, P.

    1978-01-01

    The plasma temperature is defined only if the plasma is in a state near thermodynamic equilibrium. This plasma state is analysed in detail and spectroscopic methods for measuring the temperature are discussed. As an application the hydrogen arc of the National Institute of Metrology of the Conservatoire National des Arts et Metiers (Paris) is briefly described [fr

  1. Toward Spectroscopically Detecting the Global Latitudinal Temperature Variation on the Solar Surface

    Science.gov (United States)

    Takeda, Y.; UeNo, S.

    2017-09-01

    A very slight rotation-induced latitudinal temperature variation (presumably on the order of several kelvin) on the solar surface is theoretically expected. While recent high-precision solar brightness observations reported its detection, confirmation by an alternative approach using the strengths of spectral lines is desirable, for which reducing the noise due to random fluctuation caused by atmospheric inhomogeneity is critical. Toward this difficult task, we carried out a pilot study of spectroscopically investigating the relative variation of temperature (T) at a number of points in the solar circumference region near to the limb (where latitude dependence should be detectable, if any exists) based on the equivalent widths (W) of 28 selected lines in the 5367 - 5393 Å and 6075 - 6100 Å regions. We paid special attention to i) clarifying which types of lines should be employed and ii) how much precision is attainable in practice. We found that lines with strong T-sensitivity (|log W/log T|) should be used and that very weak lines should be avoided because they inevitably suffer strong relative fluctuations (Δ W/W). Our analysis revealed that a precision of Δ T/T ≈ 0.003 (corresponding to ≈ 15 K) can be achieved at best by a spectral line with comparatively large |log W/log T|, although this can possibly be further improved When a number of lines are used all together. Accordingly, if many such favorable lines could be measured with subpercent precision of Δ W/W and by averaging the resulting Δ T/T from each line, the random noise would eventually be reduced to ≲ 1 K and detection of a very subtle amount of global T-gradient might be possible.

  2. THE YOUNG SOLAR ANALOGS PROJECT. I. SPECTROSCOPIC AND PHOTOMETRIC METHODS AND MULTI-YEAR TIMESCALE SPECTROSCOPIC RESULTS

    Energy Technology Data Exchange (ETDEWEB)

    Gray, R. O.; Briley, M. M.; Lambert, R. A.; Fuller, V. A.; Newsome, I. M.; Seeds, M. F. [Department of Physics and Astronomy, Appalachian State University, Boone, NC 26808 (United States); Saken, J. M.; Kahvaz, Y. [Department of Physics and Physical Science, Marshall University, Huntington, WV 25755 (United States); Corbally, C. J. [Vatican Observatory Research Group, Steward Observatory, Tucson, AZ 85721-0065 (United States)

    2015-12-15

    This is the first in a series of papers presenting methods and results from the Young Solar Analogs Project, which began in 2007. This project monitors both spectroscopically and photometrically a set of 31 young (300–1500 Myr) solar-type stars with the goal of gaining insight into the space environment of the Earth during the period when life first appeared. From our spectroscopic observations we derive the Mount Wilson S chromospheric activity index (S{sub MW}), and describe the method we use to transform our instrumental indices to S{sub MW} without the need for a color term. We introduce three photospheric indices based on strong absorption features in the blue-violet spectrum—the G-band, the Ca i resonance line, and the Hydrogen-γ line—with the expectation that these indices might prove to be useful in detecting variations in the surface temperatures of active solar-type stars. We also describe our photometric program, and in particular our “Superstar technique” for differential photometry which, instead of relying on a handful of comparison stars, uses the photon flux in the entire star field in the CCD image to derive the program star magnitude. This enables photometric errors on the order of 0.005–0.007 magnitude. We present time series plots of our spectroscopic data for all four indices, and carry out extensive statistical tests on those time series demonstrating the reality of variations on timescales of years in all four indices. We also statistically test for and discover correlations and anti-correlations between the four indices. We discuss the physical basis of those correlations. As it turns out, the “photospheric” indices appear to be most strongly affected by emission in the Paschen continuum. We thus anticipate that these indices may prove to be useful proxies for monitoring emission in the ultraviolet Balmer continuum. Future papers in this series will discuss variability of the program stars on medium (days–months) and short

  3. Spectroscopic Identification of Cool White Dwarfs in the Solar Neighborhood

    Czech Academy of Sciences Publication Activity Database

    Kawka, Adela; Vennes, S.

    2006-01-01

    Roč. 643, č. 1 (2006), s. 402-415 ISSN 0004-637X R&D Projects: GA ČR GP205/05/P186 Institutional research plan: CEZ:AV0Z10030501 Keywords : white dwarfs * solar neighborhood * atmospheres Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 6.119, year: 2006

  4. Spectroscopic Measurements of Target Preheating on OMEGA

    International Nuclear Information System (INIS)

    Elton, R.C.; Griem, H.R.; Iglesias, E.J.

    2000-01-01

    The preheating of laser-heated microballoon targets has been measured by time-resolved x-ray and extreme ultraviolet (euv) spectroscopy on the 30 kJ, 351 nm, 60-beam laser-fusion system at the University of Rochester Laboratory for Laser Energetics. Thin coatings of aluminum overcoated with magnesium served as indicators. both the sequence of the x-ray line emission and the intensity of euv radiation were used to determine a preheating peaking at ∼ 10 ns prior to onset of the main laser pulse, with a power density ≅1% of the main pulse. The measurements are supported by numerical modeling. Further information is provided by absorption spectra from the aluminum coating, backlighted by continuum from the heated surface. The exact source of the preheating energy remains unknown at present, but most likely arrives from early laser leakage through the system. The present target diagnostic is particularly useful when all beams cannot be monitored directly at all laser wavelengths

  5. 3D-Mössbauer spectroscopic microscope for mc-Si solar cell evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ino, Y., E-mail: y-ino@ob.sist.ac.jp; Soejima, H.; Hayakawa, K.; Yukihira, K.; Tanaka, K.; Fujita, H.; Watanabe, T. [Shizuoka Institute of Science and Technology (Japan); Ogai, K.; Moriguchi, K.; Harada, Y. [APCO. Ltd. (Japan); Yoshida, Y. [Shizuoka Institute of Science and Technology (Japan)

    2016-12-15

    A 3D-Mössbauer Spectroscopic Microscope is developed to evaluate Fe impurities in multi-crystalline Si solar cells, which combines the Mössbauer spectroscopic microscope with a scanning electron microscope (SEM), an electron beam induced current (EBIC), an electron backscatter diffraction (EBSD), and an electron energy analyzer (HV-CSA). In addition, a new moving-coil-actuator with a liner encoder of 100 nm-resolution is incorporated for the operations with both a constant velocity and a constant acceleration mode successfully with the same precision as that obtained by the conventional transducers. Furthermore, a new multi-capillary X-ray lens is designed to achieve a γ-ray spot size less than 100 μm in diameter. The new microscope provides us to investigate the space correlation between Fe impurities and the lattice defects such as grain boundaries in multi-crystalline Si solar cells.

  6. Transient full-field vibration measurement using spectroscopical stereo photogrammetry.

    Science.gov (United States)

    Yue, Kaiduan; Li, Zhongke; Zhang, Ming; Chen, Shan

    2010-12-20

    Contrasted with other vibration measurement methods, a novel spectroscopical photogrammetric approach is proposed. Two colored light filters and a CCD color camera are used to achieve the function of two traditional cameras. Then a new calibration method is presented. It focuses on the vibrating object rather than the camera and has the advantage of more accuracy than traditional camera calibration. The test results have shown an accuracy of 0.02 mm.

  7. Solar Energy Measurement Using Arduino

    Directory of Open Access Journals (Sweden)

    Jumaat Siti Amely

    2018-01-01

    Full Text Available This project aims to develop a measurement of solar energy using Arduino Board technology. In this research, four parameters that been measured are temperature, light intensity, voltage and current. The temperature was measured using temperature sensor. The light intensity was measured using light dependent resistor (LDR sensor. The voltage was measured using the voltage divider because the voltage generated by the solar panel are large for the Arduino as receiver. Lastly for the current was measured using the current sensor module that can sense the current generated by the solar panel. These parameters as the input value for the Arduino and the output was display at the Liquid Crystal Display (LCD screen. The LCD screen display output of the temperature, the light intensity, the voltage and the current value. The purpose of Arduino to convert the analog input of parameter to the digital output and display via LCD screen. Other than that, this project also involve with a design to ensure that device case are easy to be carry around.

  8. Cosmic homogeneity: a spectroscopic and model-independent measurement

    Science.gov (United States)

    Gonçalves, R. S.; Carvalho, G. C.; Bengaly, C. A. P., Jr.; Carvalho, J. C.; Bernui, A.; Alcaniz, J. S.; Maartens, R.

    2018-03-01

    Cosmology relies on the Cosmological Principle, i.e. the hypothesis that the Universe is homogeneous and isotropic on large scales. This implies in particular that the counts of galaxies should approach a homogeneous scaling with volume at sufficiently large scales. Testing homogeneity is crucial to obtain a correct interpretation of the physical assumptions underlying the current cosmic acceleration and structure formation of the Universe. In this letter, we use the Baryon Oscillation Spectroscopic Survey to make the first spectroscopic and model-independent measurements of the angular homogeneity scale θh. Applying four statistical estimators, we show that the angular distribution of galaxies in the range 0.46 < z < 0.62 is consistent with homogeneity at large scales, and that θh varies with redshift, indicating a smoother Universe in the past. These results are in agreement with the foundations of the standard cosmological paradigm.

  9. SPECTROSCOPIC AND INTERFEROMETRIC MEASUREMENTS OF NINE K GIANT STARS

    Energy Technology Data Exchange (ETDEWEB)

    Baines, Ellyn K. [Remote Sensing Division, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Döllinger, Michaela P. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Guenther, Eike W.; Hatzes, Artie P. [Thüringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg (Germany); Hrudkovu, Marie [Isaac Newton Group of Telescopes, Apartado de Correos 321, E-387 00 Santa Cruz de la Palma, Canary Islands (Spain); Belle, Gerard T. van, E-mail: ellyn.baines@nrl.navy.mil [Lowell Observatory, Flagstaff, AZ 86001 (United States)

    2016-09-01

    We present spectroscopic and interferometric measurements for a sample of nine K giant stars. These targets are of particular interest because they are slated for stellar oscillation observations. Our improved parameters will directly translate into reduced errors in the final masses for these stars when interferometric radii and asteroseismic densities are combined. Here, we determine each star’s limb-darkened angular diameter, physical radius, luminosity, bolometric flux, effective temperature, surface gravity, metallicity, and mass. When we compare our interferometric and spectroscopic results, we find no systematic offsets in the diameters and the values generally agree within the errors. Our interferometric temperatures for seven of the nine stars are hotter than those determined from spectroscopy with an average difference of about 380 K.

  10. A spectroscopic transfer standard for accurate atmospheric CO measurements

    Science.gov (United States)

    Nwaboh, Javis A.; Li, Gang; Serdyukov, Anton; Werhahn, Olav; Ebert, Volker

    2016-04-01

    Atmospheric carbon monoxide (CO) is a precursor of essential climate variables and has an indirect effect for enhancing global warming. Accurate and reliable measurements of atmospheric CO concentration are becoming indispensable. WMO-GAW reports states a compatibility goal of ±2 ppb for atmospheric CO concentration measurements. Therefore, the EMRP-HIGHGAS (European metrology research program - high-impact greenhouse gases) project aims at developing spectroscopic transfer standards for CO concentration measurements to meet this goal. A spectroscopic transfer standard would provide results that are directly traceable to the SI, can be very useful for calibration of devices operating in the field, and could complement classical gas standards in the field where calibration gas mixtures in bottles often are not accurate, available or stable enough [1][2]. Here, we present our new direct tunable diode laser absorption spectroscopy (dTDLAS) sensor capable of performing absolute ("calibration free") CO concentration measurements, and being operated as a spectroscopic transfer standard. To achieve the compatibility goal stated by WMO for CO concentration measurements and ensure the traceability of the final concentration results, traceable spectral line data especially line intensities with appropriate uncertainties are needed. Therefore, we utilize our new high-resolution Fourier-transform infrared (FTIR) spectroscopy CO line data for the 2-0 band, with significantly reduced uncertainties, for the dTDLAS data evaluation. Further, we demonstrate the capability of our sensor for atmospheric CO measurements, discuss uncertainty calculation following the guide to the expression of uncertainty in measurement (GUM) principles and show that CO concentrations derived using the sensor, based on the TILSAM (traceable infrared laser spectroscopic amount fraction measurement) method, are in excellent agreement with gravimetric values. Acknowledgement Parts of this work have been

  11. Measurements of Solar Vector Magnetic Fields

    Science.gov (United States)

    Hagyard, M. J. (Editor)

    1985-01-01

    Various aspects of the measurement of solar magnetic fields are presented. The four major subdivisions of the study are: (1) theoretical understanding of solar vector magnetic fields; (3) techniques for interpretation of observational data; and (4) techniques for data display.

  12. Measurements of Solar Vector Magnetic Fields

    International Nuclear Information System (INIS)

    Hagyard, M.J.

    1985-05-01

    Various aspects of the measurement of solar magnetic fields are presented. The four major subdivisions of the study are: (1) theoretical understanding of solar vector magnetic fields; (3) techniques for interpretation of observational data; and (4) techniques for data display

  13. Solar rotation measurements at Mount Wilson. Pt. 2

    International Nuclear Information System (INIS)

    Labonte, B.J.; Howard, R.; Carnegie Institution of Washington, Pasadena

    1981-01-01

    Possible sources of systematic error in solar Doppler rotational velocities are examined. Scattered light is shown to affect the Mount Wilson solar rotation results, but this effect is not enough to bring the spectroscopic results in coincidence with the sunspot rotation. Interference fringes at the spectrograph focus at Mount Wilson have in two intervals affected the rotation results. It has been possible to correlate this error with temperature and thus correct for it. A misalignment between the entrance and exit slits is a possible source of error, but for the Mount Wilson slit configuration the amplitude of this effect is negligibly small. Rapid scanning of the solar image also produces no measurable effect. (orig.)

  14. Zeff from spectroscopic bremsstrahlung measurements at ASDEX Upgrade and JET

    International Nuclear Information System (INIS)

    Meister, H.; Fischer, R.; Horton, L.D.; Maggi, C.F.; Nishijima, D.; Giroud, C.; Zastrow, K.-D.; Zaniol, B.

    2004-01-01

    The effective ionic charge Z eff is a means to assess the impurity content of a fusion plasma. It can be derived from measurements of bremsstrahlung intensity. These have been extended at ASDEX Upgrade by the usage of the sight lines for the charge exchange recombination diagnostic. Together with a previously installed sight line array, it is now possible to routinely determine the bremsstrahlung intensity over the whole minor radius purely from spectroscopic measurements. In a tokamak where the plasma facing components are made up of various materials, this is necessary to check if measurements are contaminated by line radiation. The bremsstrahlung background of the respective spectra is determined using Bayesian probability theory, giving consistent and improved error statistics. Using the information for electron temperature and density profiles, the Z eff profile is determined by an integrated method. The same approach to assess the Z eff profile has been demonstrated to be successful also at the JET tokamak

  15. Spectroscopic measurements of anode plasma with cryogenic pulsed ion sources

    International Nuclear Information System (INIS)

    Yoneda, H.; Urata, T.; Ohbayashi, K.; Kim, Y.; Horioka, K.; Kasuya, K.

    1987-01-01

    In ion beam diodes, electromagnetic wave is coupled to ion beam. Ion is extracted from anode plasma, which is produced early in the power pulse. However, exact mechanism of anode plasma production, expansion and ion extraction process is unknown. In particularly, anode plasma expansion is seemed to be one of the reasons of rapid impedance collapse of the diode, which is serious problem in high power experiments. Some experimental results showed that anode plasma expansion velocity was about 5 times larger than that inferred from simple thermal velocity. Several explanations for these results were proposed; for example, electron collisionarity in anode plasma, fast neutral gas particle, diamagnetism. To solve this question, it is necessary to measure the characteristic of anode plasma with space and time resolution. The authors made spectroscopic measurements to investigate variety of electron temperature, electron density, expansion velocity of anode plasma with various ion sources

  16. Crosstalk in solar polarization measurements

    Science.gov (United States)

    West, E. A.; Balasubramaniam, K. S.

    1992-01-01

    The instrumental crosstalk associated with the Marshall Space Flight Center Vector Magnetograph and the solar crosstalk created by the magnetic field are described and their impact on the reconstruction of the solar vector magnetic field is analyzed. It is pointed out that identifying and correcting the crosstalk is important in the development of realistic models describing the solar atmosphere. Solar crosstalk is spatially dependent on the structure of the magnetic field while instrumental crosstalk is dependent on the position of the analyzer.

  17. Development of a Neutron Spectroscopic System Utilizing Compressed Sensing Measurements

    Directory of Open Access Journals (Sweden)

    Vargas Danilo

    2016-01-01

    Full Text Available A new approach to neutron detection capable of gathering spectroscopic information has been demonstrated. The approach relies on an asymmetrical arrangement of materials, geometry, and an ability to change the orientation of the detector with respect to the neutron field. Measurements are used to unfold the energy characteristics of the neutron field using a new theoretical framework of compressed sensing. Recent theoretical results show that the number of multiplexed samples can be lower than the full number of traditional samples while providing the ability to have some super-resolution. Furthermore, the solution approach does not require a priori information or inclusion of physics models. Utilizing the MCNP code, a number of candidate detector geometries and materials were modeled. Simulations were carried out for a number of neutron energies and distributions with preselected orientations for the detector. The resulting matrix (A consists of n rows associated with orientation and m columns associated with energy and distribution where n < m. The library of known responses is used for new measurements Y (n × 1 and the solver is able to determine the system, Y = Ax where x is a sparse vector. Therefore, energy spectrum measurements are a combination of the energy distribution information of the identified elements of A. This approach allows for determination of neutron spectroscopic information using a single detector system with analog multiplexing. The analog multiplexing allows the use of a compressed sensing solution similar to approaches used in other areas of imaging. A single detector assembly provides improved flexibility and is expected to reduce uncertainty associated with current neutron spectroscopy measurement.

  18. Coordinated weather balloon solar radiation measurements during a solar eclipse.

    Science.gov (United States)

    Harrison, R G; Marlton, G J; Williams, P D; Nicoll, K A

    2016-09-28

    Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'. © 2016 The Authors.

  19. Scientific Considerations for Future Spectroscopic Measurements from Space of Activity on the Sun

    Science.gov (United States)

    Holman, Gordon D.

    2016-01-01

    High-resolution UV and X-ray spectroscopy are important to understanding the origin and evolution of magnetic energy release in the solar atmosphere, as well as the subsequent evolution of heated plasma and accelerated particles. Electromagnetic radiation is observed from plasma heated to temperatures ranging from about 10 k K to above 10 MK, from accelerated electrons emitting photons primarily at X-ray energies, and from ions emitting in gamma rays. These observations require space-based instruments sensitive to emissions at wavelengths shorter than the near UV. This article reviews some recent observations with emphasis on solar eruptive events, the models that describe them, and the measurements they indicate are needed for substantial progress in the future. Specific examples are discussed demonstrating that imaging spectroscopy with a cadence of seconds or better is needed to follow, understand, and predict the evolution of solar activity. Critical to substantial progress is the combination of a judicious choice of UV, EUV, and soft X-ray imaging spectroscopy sensitive to the evolution of this thermal plasma combined with hard X-ray imaging spectroscopy sensitive to suprathermal electrons. The major challenge will be to conceive instruments that, within the bounds of possible technologies and funding, have the flexibility and field of view to obtain spectroscopic observations where and when events occur while providing an optimum balance of dynamic range, spectral resolution and range, and spatial resolution.

  20. Optical constants of graphene measured by spectroscopic ellipsometry

    NARCIS (Netherlands)

    Weber, J.W.; Calado, V.E.; Van de Sanden, M.C.M.

    2010-01-01

    A mechanically exfoliated graphene flake ( ? 150×380??m2) on a silicon wafer with 98 nm silicon dioxide on top was scanned with a spectroscopic ellipsometer with a focused spot ( ? 100×55??m2) at an angle of 55°. The spectroscopic ellipsometric data were analyzed with an optical model in which the

  1. Optical constants of graphene measured by spectroscopic ellipsometry

    NARCIS (Netherlands)

    Weber, J.W.; Calado, V.E.; Sanden, van de M.C.M.

    2010-01-01

    A mechanically exfoliated graphene flake ( ~ 150×380 µm2) on a silicon wafer with 98 nm silicon dioxide on top was scanned with a spectroscopic ellipsometer with a focused spot ( ~ 100×55 µm2) at an angle of 55°. The spectroscopic ellipsometric data were analyzed with an optical model in which the

  2. The measurement of solar magnetic fields

    International Nuclear Information System (INIS)

    Stenflo, J.O.

    1978-01-01

    Solar activity is basically caused by the interaction between magnetic fields, solar rotation and convective motions. Detailed mapping of the Sun's rapidly varying magnetic field helps in the understanding of the mechanisms of solar activity. Observations in recent years have revealed unexpected and intriguing properties of solar magnetic fields, the explanation of which has become a challenge to plasma physicists. This review deals primarily with how the Sun's magnetic field is measured, but it also includes a brief review of the present observational picture of the magnetic field, which is needed to understand the problems of how to properly interpret the observations. 215 references. (author)

  3. Investigation and measures to noise on spectroscopic measurement system in JT-60U

    International Nuclear Information System (INIS)

    Nagaya, Susumu; Kubo, Hirotaka; Sugie, Tatsuo; Onizawa, Masami; Kawai, Isao; Nakata, Hisao.

    1997-11-01

    Breakdown of a negative-ion-based neutral beam injection (N-NBI) has caused noise trouble to several systems. The control circuit of a spectroscopic measurement system had not well worked because of the noise. The noise has been measured by an optical-fiber isolation system during operation of JT-60U. The amplitude and the frequency were 15-18 V and 15 MHz respectively. The transmission noise has been reduced by putting ferrite cores to all cables connecting with the control circuits. As a result, the trouble with the spectroscopic measurement system has completely been solved. Adding condensers and resistors to the circuit was not effective to reduce the noise. (author)

  4. SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems

    Energy Technology Data Exchange (ETDEWEB)

    Eisenstein, Daniel J.; /Arizona U., Astron. Dept. - Steward Observ. /Harvard U., Phys. Dept.; Weinberg, David H.; /Ohio State U.; Agol, Eric; /Washington U., Seattle, Astron. Dept.; Aihara, Hiroaki; /Tokyo U.; Prieto, Carlos Allende; /Laguna U., Tenerife; Anderson, Scott F.; /Washington U., Seattle, Astron. Dept.; Arns, James A.; /Michigan U.; Aubourg, Eric; /APC, Paris /DAPNIA, Saclay; Bailey, Stephen; /LBL, Berkeley; Balbinot, Eduardo; /Rio Grande do Sul U. /Rio de Janeiro Observ.; Barkhouser, Robert; /Johns Hopkins U. /Michigan State U.

    2011-01-01

    Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. The Baryon Oscillation Spectroscopic Survey (BOSS) will measure redshifts of 1.5 million massive galaxies and Ly{alpha} forest spectra of 150,000 quasars, using the baryon acoustic oscillation (BAO) feature of large scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z < 0.7 and at z {approx} 2.5. SEGUE-2, a now-completed continuation of the Sloan Extension for Galactic Understanding and Exploration, measured medium-resolution (R = {lambda}/{Delta}{lambda} 1800) optical spectra of 118,000 stars in a variety of target categories, probing chemical evolution, stellar kinematics and substructure, and the mass profile of the dark matter halo from the solar neighborhood to distances of 100 kpc. APOGEE, the Apache Point Observatory Galactic Evolution Experiment, will obtain high-resolution (R {approx} 30,000), high signal-to-noise ratio (S/N {ge} 100 per resolution element), H-band (1.51 {micro}m < {lambda} < 1.70 {micro}m) spectra of 10{sup 5} evolved, late-type stars, measuring separate abundances for {approx} 15 elements per star and creating the first high-precision spectroscopic survey of all Galactic stellar populations (bulge, bar, disks, halo) with a uniform set of stellar tracers and spectral diagnostics. The Multi-object APO Radial Velocity Large-area Survey (MARVELS) will monitor radial velocities of more than 8000 FGK stars with the sensitivity and cadence (10-40 m s{sup -1}, {approx} 24 visits per star) needed to detect giant planets with periods up to two years, providing an unprecedented data set for understanding the formation and dynamical evolution of giant planet systems. As of January 2011, SDSS-III has obtained

  5. SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way, and Extra-Solar Planetary Systems

    Science.gov (United States)

    Eisenstein, Daniel J.; Weinberg, David H.; Agol, Eric; Aihara, Hiroaki; Allende Prieto, Carlos; Anderson, Scott F.; Arns, James A.; Aubourg, Éric; Bailey, Stephen; Balbinot, Eduardo; Barkhouser, Robert; Beers, Timothy C.; Berlind, Andreas A.; Bickerton, Steven J.; Bizyaev, Dmitry; Blanton, Michael R.; Bochanski, John J.; Bolton, Adam S.; Bosman, Casey T.; Bovy, Jo; Brandt, W. N.; Breslauer, Ben; Brewington, Howard J.; Brinkmann, J.; Brown, Peter J.; Brownstein, Joel R.; Burger, Dan; Busca, Nicolas G.; Campbell, Heather; Cargile, Phillip A.; Carithers, William C.; Carlberg, Joleen K.; Carr, Michael A.; Chang, Liang; Chen, Yanmei; Chiappini, Cristina; Comparat, Johan; Connolly, Natalia; Cortes, Marina; Croft, Rupert A. C.; Cunha, Katia; da Costa, Luiz N.; Davenport, James R. A.; Dawson, Kyle; De Lee, Nathan; Porto de Mello, Gustavo F.; de Simoni, Fernando; Dean, Janice; Dhital, Saurav; Ealet, Anne; Ebelke, Garrett L.; Edmondson, Edward M.; Eiting, Jacob M.; Escoffier, Stephanie; Esposito, Massimiliano; Evans, Michael L.; Fan, Xiaohui; Femenía Castellá, Bruno; Dutra Ferreira, Leticia; Fitzgerald, Greg; Fleming, Scott W.; Font-Ribera, Andreu; Ford, Eric B.; Frinchaboy, Peter M.; García Pérez, Ana Elia; Gaudi, B. Scott; Ge, Jian; Ghezzi, Luan; Gillespie, Bruce A.; Gilmore, G.; Girardi, Léo; Gott, J. Richard; Gould, Andrew; Grebel, Eva K.; Gunn, James E.; Hamilton, Jean-Christophe; Harding, Paul; Harris, David W.; Hawley, Suzanne L.; Hearty, Frederick R.; Hennawi, Joseph F.; González Hernández, Jonay I.; Ho, Shirley; Hogg, David W.; Holtzman, Jon A.; Honscheid, Klaus; Inada, Naohisa; Ivans, Inese I.; Jiang, Linhua; Jiang, Peng; Johnson, Jennifer A.; Jordan, Cathy; Jordan, Wendell P.; Kauffmann, Guinevere; Kazin, Eyal; Kirkby, David; Klaene, Mark A.; Knapp, G. R.; Kneib, Jean-Paul; Kochanek, C. S.; Koesterke, Lars; Kollmeier, Juna A.; Kron, Richard G.; Lampeitl, Hubert; Lang, Dustin; Lawler, James E.; Le Goff, Jean-Marc; Lee, Brian L.; Lee, Young Sun; Leisenring, Jarron M.; Lin, Yen-Ting; Liu, Jian; Long, Daniel C.; Loomis, Craig P.; Lucatello, Sara; Lundgren, Britt; Lupton, Robert H.; Ma, Bo; Ma, Zhibo; MacDonald, Nicholas; Mack, Claude; Mahadevan, Suvrath; Maia, Marcio A. G.; Majewski, Steven R.; Makler, Martin; Malanushenko, Elena; Malanushenko, Viktor; Mandelbaum, Rachel; Maraston, Claudia; Margala, Daniel; Maseman, Paul; Masters, Karen L.; McBride, Cameron K.; McDonald, Patrick; McGreer, Ian D.; McMahon, Richard G.; Mena Requejo, Olga; Ménard, Brice; Miralda-Escudé, Jordi; Morrison, Heather L.; Mullally, Fergal; Muna, Demitri; Murayama, Hitoshi; Myers, Adam D.; Naugle, Tracy; Neto, Angelo Fausti; Nguyen, Duy Cuong; Nichol, Robert C.; Nidever, David L.; O'Connell, Robert W.; Ogando, Ricardo L. C.; Olmstead, Matthew D.; Oravetz, Daniel J.; Padmanabhan, Nikhil; Paegert, Martin; Palanque-Delabrouille, Nathalie; Pan, Kaike; Pandey, Parul; Parejko, John K.; Pâris, Isabelle; Pellegrini, Paulo; Pepper, Joshua; Percival, Will J.; Petitjean, Patrick; Pfaffenberger, Robert; Pforr, Janine; Phleps, Stefanie; Pichon, Christophe; Pieri, Matthew M.; Prada, Francisco; Price-Whelan, Adrian M.; Raddick, M. Jordan; Ramos, Beatriz H. F.; Reid, I. Neill; Reyle, Celine; Rich, James; Richards, Gordon T.; Rieke, George H.; Rieke, Marcia J.; Rix, Hans-Walter; Robin, Annie C.; Rocha-Pinto, Helio J.; Rockosi, Constance M.; Roe, Natalie A.; Rollinde, Emmanuel; Ross, Ashley J.; Ross, Nicholas P.; Rossetto, Bruno; Sánchez, Ariel G.; Santiago, Basilio; Sayres, Conor; Schiavon, Ricardo; Schlegel, David J.; Schlesinger, Katharine J.; Schmidt, Sarah J.; Schneider, Donald P.; Sellgren, Kris; Shelden, Alaina; Sheldon, Erin; Shetrone, Matthew; Shu, Yiping; Silverman, John D.; Simmerer, Jennifer; Simmons, Audrey E.; Sivarani, Thirupathi; Skrutskie, M. F.; Slosar, Anže; Smee, Stephen; Smith, Verne V.; Snedden, Stephanie A.; Stassun, Keivan G.; Steele, Oliver; Steinmetz, Matthias; Stockett, Mark H.; Stollberg, Todd; Strauss, Michael A.; Szalay, Alexander S.; Tanaka, Masayuki; Thakar, Aniruddha R.; Thomas, Daniel; Tinker, Jeremy L.; Tofflemire, Benjamin M.; Tojeiro, Rita; Tremonti, Christy A.; Vargas Magaña, Mariana; Verde, Licia; Vogt, Nicole P.; Wake, David A.; Wan, Xiaoke; Wang, Ji; Weaver, Benjamin A.; White, Martin; White, Simon D. M.; Wilson, John C.; Wisniewski, John P.; Wood-Vasey, W. Michael; Yanny, Brian; Yasuda, Naoki; Yèche, Christophe; York, Donald G.; Young, Erick; Zasowski, Gail; Zehavi, Idit; Zhao, Bo

    2011-09-01

    Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. In keeping with SDSS tradition, SDSS-III will provide regular public releases of all its data, beginning with SDSS Data Release 8 (DR8), which was made public in 2011 January and includes SDSS-I and SDSS-II images and spectra reprocessed with the latest pipelines and calibrations produced for the SDSS-III investigations. This paper presents an overview of the four surveys that comprise SDSS-III. The Baryon Oscillation Spectroscopic Survey will measure redshifts of 1.5 million massive galaxies and Lyα forest spectra of 150,000 quasars, using the baryon acoustic oscillation feature of large-scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z R = λ/Δλ ≈ 1800) optical spectra of 118,000 stars in a variety of target categories, probing chemical evolution, stellar kinematics and substructure, and the mass profile of the dark matter halo from the solar neighborhood to distances of 100 kpc. APOGEE, the Apache Point Observatory Galactic Evolution Experiment, will obtain high-resolution (R ≈ 30,000), high signal-to-noise ratio (S/N >= 100 per resolution element), H-band (1.51 μm data set for understanding the formation and dynamical evolution of giant planet systems. As of 2011 January, SDSS-III has obtained spectra of more than 240,000 galaxies, 29,000 z >= 2.2 quasars, and 140,000 stars, including 74,000 velocity measurements of 2580 stars for MARVELS.

  6. Technical report for fabrication and performance test of electrochemical/spectroscopic measurement system

    International Nuclear Information System (INIS)

    Park, Yong Joon; Cho, Young Hwan; Bae, Sang Eun; Im, Hee Jung; Song, Kyu Seok

    2010-01-01

    Development of evaluation technology of electrochemical reactions is very essential to understand chemical behavior of actinides and lanthanides in molten salt media in relation to the development of Pyrochemical process. The on-line electrochemical/spectroscopic measurement system is to produce electrochemical parameters and thermodynamic parameters of actinides and lanthanides in molten salts by using spectroscopic techniques such as UV-VIS absorption as well as electrochemical in-situ measurement techniques. The on-line electrochemical/spectroscopic measurement system can be applied to understand the chemical reactions and oxidation states of actinides and lanthanides in molten salts eventually for the Pyrochemical process

  7. On-line data processing apparatus for spectroscopic measurements of atomic uranium

    International Nuclear Information System (INIS)

    Miron, E.; Levin, L.A.; Erez, G; Baumatz, D; Goren, I.; Shpancer, I.

    1977-01-01

    A computer-based apparatus for on-line spectroscopic measurements of atomic uranium is described. The system is capable of enhancing the signal-to-noise ratio by averaging, and performing calculations. Computation flow charts and programs are included

  8. Solar Cell Calibration and Measurement Techniques

    Science.gov (United States)

    Bailey, Sheila; Brinker, Dave; Curtis, Henry; Jenkins, Phillip; Scheiman, Dave

    2004-01-01

    The increasing complexity of space solar cells and the increasing international markets for both cells and arrays has resulted in workshops jointly sponsored by NASDA, ESA and NASA. These workshops are designed to obtain international agreement on standardized values for the AMO spectrum and constant, recommend laboratory measurement practices and establish a set of protocols for international comparison of laboratory measurements. A working draft of an ISO standard, WD15387, "Requirements for Measurement and Calibration Procedures for Space Solar Cells" was discussed with a focus on the scope of the document, a definition of primary standard cell, and required error analysis for all measurement techniques. Working groups addressed the issues of Air Mass Zero (AMO) solar constant and spectrum, laboratory measurement techniques, and te international round robin methodology. A summary is presented of the current state of each area and the formulation of the ISO document.

  9. Measurement tolerance analysis of solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cimo, J.; Maderkova, L.; Horak, J.; Igaz, D.; Pasztorova, S. [Department of Biomereorlogy and Hydrology, Slovak Agriculture University, Nitra (Slovakia)

    2012-07-01

    Solar radiant energy is bane and almost the only one source of heat for Earth 's surface and for atmosphere, and almost the only one source of energy for physical processes. Solar energy is one of the most available and the most ecological energy source. Currently the firm Kipp and Zonen belongs to prominent producer of sensors for measuring of global radiation. These sensors are the most used in our country and also in network of meteorological measurements of WMO. Therefore the two types of measuring sensors for global radiation (pyranometer PMP6, CMP 11) in comparison with calculation method Savin-Angstrom are analysed. (author)

  10. Protocol of measurement techniques - Project colored solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J.-L.

    2004-08-15

    This illustrated annual report for the Swiss Federal Office of Energy (SFOE) takes a look at work done at the Swiss Federal Institute of Technology in Lausanne, Switzerland, on multi-layer, thin-film interference coatings for solar collector glazing. The correct combinations of refractive indices and film thickness are discussed. The authors state that corresponding multi-layered thin film stacks will have to be realised experimentally in a controlled and reproducible way. New thin film materials are to be tailored to exhibit optimised optical and ageing properties. The development of these coatings is to be based on various measurement techniques, such as spectro-photometry, measurements of total power throughput by means of a solar simulator, spectroscopic ellipsometry, scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The paper provides many examples of typical data and explains which film properties can be inferred from each method and thus describes both the function and purpose of the different measurement techniques.

  11. Spectroscopic, scanning laser OBIC, and I-V/QE characterizations of browned EVA solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Pern, F.J. [National Renewable Energy Lab., Golden, CO (United States); Eisgruber, I.L. [Materials Research Group, Inc., Wheat Ridge, CO (United States); Micheels, R.H. [Polestar Technologies, Inc., Needham Hts, MA (United States)

    1996-05-01

    The effects of ethylene-vinyl acetate (EVA) discoloration due to accelerated field or laboratory exposure on the encapsulated silicon (Si) solar cells or EVA/glass laminates were characterized quantitatively by using non-invasive, non-destructive ultraviolet-visible (UV-vis) spectrophotometry, spectrocolorimetry, spectrofluorometry, scanning laser OBIC (optical beam induced current) spectroscopy, and current-voltage (I-V) and quantum efficiency (QE) measurements. The results show that the yellowness index (YI) measured directly over the AR-coated solar cells under the glass superstrate increased from the range of -80 to -90 to the range of -20 to 15 as the EVA changed from clear to brown. The ratio of two fluorescence emission peak areas generally increased from 1.45 to 5.69 as browning increased, but dropped to 4.21 on a darker EVA. For a solar cell with brown EVA in the central region, small-area grating QE measurements and scanning laser OBIC analysis between the brown and clear EVA regions showed that the quantum efficiency loss at 633 nm was 42%-48% of the loss at 488 nm, due to a reduced decrease of transmittance in browned EVA at the longer wavelengths. The portion of the solar cell under the browned EVA showed a decrease of {approximately}36% in efficiency, as compared to the cell efficiency under clear EVA. Transmittance loss at 633 nm was 38% of the loss at 488 nm for a light yellow-brown EVA/glass laminate that showed a small increase of 10 in the yellowness index.

  12. Comparison of spectroscopically measured tissue alcohol concentration to blood and breath alcohol measurements

    Science.gov (United States)

    Ridder, Trent D.; Ver Steeg, Benjamin J.; Laaksonen, Bentley D.

    2009-09-01

    Alcohol testing is an expanding area of interest due to the impacts of alcohol abuse that extend well beyond drunk driving. However, existing approaches such as blood and urine assays are hampered in some testing environments by biohazard risks. A noninvasive, in vivo spectroscopic technique offers a promising alternative, as no body fluids are required. The purpose of this work is to report the results of a 36-subject clinical study designed to characterize tissue alcohol measured using near-infrared spectroscopy relative to venous blood, capillary blood, and breath alcohol. Comparison of blood and breath alcohol concentrations demonstrated significant differences in alcohol concentration [root mean square of 9.0 to 13.5 mg/dL] that were attributable to both assay accuracy and precision as well as alcohol pharmacokinetics. A first-order kinetic model was used to estimate the contribution of alcohol pharmacokinetics to the differences in concentration observed between the blood, breath, and tissue assays. All pair-wise combinations of alcohol assays were investigated, and the fraction of the alcohol concentration variance explained by pharmacokinetics ranged from 41.0% to 83.5%. Accounting for pharmacokinetic concentration differences, the accuracy and precision of the spectroscopic tissue assay were found to be comparable to those of the blood and breath assays.

  13. Spectral and electronic measurements of solar radiation

    International Nuclear Information System (INIS)

    Suzuki, Mamoru; Hanyu, Mitsuhiro

    1977-01-01

    The spectral data of solar radiation are necessary if detailed discussion is intended in relation to the utilization of solar energy. Since those data have not been fully prepared so far, a measuring equipment developed in Electro-technical Laboratory to obtain those data is described. The laboratory is now continuing the measurement at the wavelength of 0.3 μm to 1.1 μm. The equipment employs the system to always calibrate with the standard light source, it can measure both the direct light of the sun only and the sun light including sky light, and it enables to obtain the value based on the secondary standard of spectral illumination intensity established by the laboratory. The solar spectral irradiance is determined with the current readings of photomultiplier in the standard light source and the sun-light measurements at a wavelength and with the spectral illumination intensity from the standard light source. In order to practice such measurement many times at various wavelengths, control of the equipment, data collection, computation, drawing and listing are performed by a microcomputer. As an example, the data on Sept. 10, 1976, are shown comparing the graphs at three different hours. It can be well observed that the transmissivity attenuates with shorter wavelength, and the transmissivity in near infra-red region changes greatly due to the absorption of radiation by water vapour. (Wakatsuki, Y.)

  14. A spectroscopic survey of the youngest field stars in the solar neighborhood . II. The optically faint sample

    Science.gov (United States)

    Frasca, A.; Guillout, P.; Klutsch, A.; Ferrero, R. Freire; Marilli, E.; Biazzo, K.; Gandolfi, D.; Montes, D.

    2018-05-01

    Context. Star formation in the solar neighborhood is mainly traced by young stars in open clusters, associations, and in the field, which can be identified, for example, by their X-ray emission. The determination of stellar parameters for the optical counterparts of X-ray sources is crucial for a full characterization of these stars. Aims: This work extends the spectroscopic study of the RasTyc sample, obtained by the cross-correlation of the Tycho and ROSAT All-Sky Survey catalogs, to stars fainter than V = 9.5 mag and aims to identify sparse populations of young stars in the solar neighborhood. Methods: We acquired 625 high-resolution spectra for 443 presumably young stars with four different instruments in the northern hemisphere. The radial and rotational velocity (vsini) of our targets were measured by means of the cross-correlation technique, which is also helpful to discover single-lined (SB1), double-lined spectroscopic binaries (SB2), and multiple systems. We used the code ROTFIT to perform an MK spectral classification and to determine the atmospheric parameters (Teff, logg, [Fe/H]) and vsini of the single stars and SB1 systems. For these objects, we used the spectral subtraction of slowly rotating templates to measure the equivalent widths of the Hα and Li I 6708 Å lines, which enabled us to derive their chromospheric activity level and lithium abundance. We made use of Gaia DR1 parallaxes and proper motions to locate the targets in the Hertzsprung-Russell (HR) diagram and to compute the space velocity components of the youngest objects. Results: We find a remarkable percentage (at least 35%) of binaries and multiple systems. On the basis of the lithium abundance, the sample of single stars and SB1 systems appears to be mostly ( 60%) composed of stars younger than the members of the UMa cluster. The remaining sources are in the age range between the UMa and Hyades clusters ( 20%) or older ( 20%). In total, we identify 42 very young (PMS-like) stars

  15. Spectroscopic investigation of new fullerene based acceptors for organic solar cells; Spektroskopische Untersuchung neuartiger Fullerenakzeptoren fuer organische Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Liedte, Moritz Nils

    2012-04-27

    high open circuit voltage of 835 mV in the devices produced, but also a rather low current density. I tried to understand the processes in the charge carrier generation and extraction process causing this. Using several measurement techniques, combined with general knowledge about comparable endohedral fullerenes from the literature, I was able to identify an internal charge transfer of electrons from the lutetium atoms encaged in the C{sub 80} to the fullerene bulk as origin The results presented in this work give further indications for the advantages of using C{sub 70} based fullerene acceptors in organic solar cells to raise the total power conversion efficiencies of these devices, despite the higher production costs. The identification of anion signatures of different fullerenes show an additional method to monitor the excitation processes by optical spectroscopy in bulk-heterojunction devices. My research regarding the Lu{sub 3}N rate at C{sub 80} molecule showed a general effect regarding this class of molecules, that will be important for any further synthesizes or application of such molecules in organic photovoltaics. While the projects regarding the dimer acceptors and the Lu{sub 3}N rate at C{sub 80} molecule were completed in this work, the analysis of spectroscopic anion signatures left some open questions, especially for large fullerenes. Further investigations using spin sensitive or time resolved techniques, as available in our research group, could be useful to gather more detailed information on this topic. Also trying to get some PC{sub 81}BM for photoinduced absorption measurements, alone and in blend with several polymers, might be another way to energetically pinpoint the anion signature on C{sub 80}.

  16. Helioseismic measurements in the solar envelope using group velocities of surface waves

    Science.gov (United States)

    Vorontsov, S. V.; Baturin, V. A.; Ayukov, S. V.; Gryaznov, V. K.

    2014-07-01

    At intermediate- and high-degree l, solar p and f modes can be considered as surface waves. Using variational principle, we derive an integral expression for the group velocities of the surface waves in terms of adiabatic eigenfunctions of normal modes, and address the benefits of using group-velocity measurements as a supplementary diagnostic tool in solar seismology. The principal advantage of using group velocities, when compared with direct analysis of the oscillation frequencies, comes from their smaller sensitivity to the uncertainties in the near-photospheric layers. We address some numerical examples where group velocities are used to reveal inconsistencies between the solar models and the seismic data. Further, we implement the group-velocity measurements to the calibration of the specific entropy, helium abundance Y, and heavy-element abundance Z in the adiabatically stratified part of the solar convective envelope, using different recent versions of the equation of state. The results are in close agreement with our earlier measurements based on more sophisticated analysis of the solar oscillation frequencies. These results bring further support to the downward revision of the solar heavy-element abundances in recent spectroscopic measurements.

  17. Spectroscopic imaging of photopotentials and photoinduced potential fluctuations in a bulk heterojunction solar cell film.

    Science.gov (United States)

    Luria, Justin L; Hoepker, Nikolas; Bruce, Robert; Jacobs, Andrew R; Groves, Chris; Marohn, John A

    2012-11-27

    We present spatially resolved photovoltage spectra of a bulk heterojunction solar cell film composed of phase-separated poly(9,9'-dioctylfluorene-co-benzothiadiazole) (F8BT) and poly(9,9'-dioctylfluorene-co-bis-N,N'-(4-butylphenyl)-bis-N,N'-phenyl-1,4-phenylenediamine) (PFB) polymers prepared on ITO/PEDOT:PSS and aluminum substrates. Over both PFB- and F8BT-rich domains, the photopotential spectra were found to be proportional to a linear combination of the polymers' absorption spectra. Charge trapping in the film was studied using photopotential fluctuation spectroscopy, in which low-frequency photoinduced electrostatic potential fluctuations were measured by observing noise in the oscillation frequency of a nearby charged atomic force microscope cantilever. Over both F8BT- and PFB-rich regions, the magnitude, distance dependence, frequency dependence, and illumination wavelength dependence of the observed cantilever frequency noise are consistent with photopotential fluctuations arising from stochastic light-driven trapping and detrapping of charges in F8BT. Taken together, our findings suggest a microscopic mechanism by which intermixing of phases leads to charge trapping and thereby to suppressed open-circuit voltage and decreased efficiency in this prototypical bulk heterojunction solar cell film.

  18. X-ray imaging and spectroscopic measurements of implosions

    International Nuclear Information System (INIS)

    Hammel, B.A.; Ress, D.R.; Keane, C.J.; Kilkenny, J.D.; Landen, O.L.; Bell, P.; Pasha, R.; Wallace, R.J.; Bradley, D.K.

    1992-01-01

    Time-resolved x-ray measurements are essential in the investigation of laser-driven inertial confinement fusion, where neutron and x-ray emission are the only observable signatures of the compressed core conditions. High-speed detectors, available for x-ray measurement, provide a means of measuring the rapidly evolving conditions in imploding capsules on picosecond time scales. We address a wide range of issues in our indirectly driven implosion experiments on Nova, with a large variety of x-ray measurement techniques. Critical issues include symmetry of the compressed core, fuel density and temperature and hydrodynamic mix at the pusher/fuel interface

  19. A New Method to Comprehensively Diagnose Shock Waves in the Solar Atmosphere Based on Simultaneous Spectroscopic and Imaging Observations

    Science.gov (United States)

    Ruan, Wenzhi; Yan, Limei; He, Jiansen; Zhang, Lei; Wang, Linghua; Wei, Yong

    2018-06-01

    Shock waves are believed to play an important role in plasma heating. The shock-like temporal jumps in radiation intensity and Doppler shift have been identified in the solar atmosphere. However, a quantitative diagnosis of the shocks in the solar atmosphere is still lacking, seriously hindering the understanding of shock dissipative heating of the solar atmosphere. Here, we propose a new method to realize the goal of the shock quantitative diagnosis, based on Rankine–Hugoniot equations and taking the advantages of simultaneous imaging and spectroscopic observations from, e.g., IRIS (Interface Region Imaging Spectrograph). Because of this method, the key parameters of shock candidates can be derived, such as the bulk velocity and temperature of the plasma in the upstream and downstream, the propagation speed and direction. The method is applied to the shock candidates observed by IRIS, and the overall characteristics of the shocks are revealed quantitatively for the first time. This method is also tested with the help of forward modeling, i.e., virtual observations of simulated shocks. The parameters obtained from the method are consistent with the parameters of the shock formed in the model and are independent of the viewing direction. Therefore, the method we proposed here is applicable to the quantitative and comprehensive diagnosis of the observed shocks in the solar atmosphere.

  20. Utilization of Solar Dynamics Observatory space weather digital image data for comparative analysis with application to Baryon Oscillation Spectroscopic Survey

    Science.gov (United States)

    Shekoyan, V.; Dehipawala, S.; Liu, Ernest; Tulsee, Vivek; Armendariz, R.; Tremberger, G.; Holden, T.; Marchese, P.; Cheung, T.

    2012-10-01

    Digital solar image data is available to users with access to standard, mass-market software. Many scientific projects utilize the Flexible Image Transport System (FITS) format, which requires specialized software typically used in astrophysical research. Data in the FITS format includes photometric and spatial calibration information, which may not be useful to researchers working with self-calibrated, comparative approaches. This project examines the advantages of using mass-market software with readily downloadable image data from the Solar Dynamics Observatory for comparative analysis over with the use of specialized software capable of reading data in the FITS format. Comparative analyses of brightness statistics that describe the solar disk in the study of magnetic energy using algorithms included in mass-market software have been shown to give results similar to analyses using FITS data. The entanglement of magnetic energy associated with solar eruptions, as well as the development of such eruptions, has been characterized successfully using mass-market software. The proposed algorithm would help to establish a publicly accessible, computing network that could assist in exploratory studies of all FITS data. The advances in computer, cell phone and tablet technology could incorporate such an approach readily for the enhancement of high school and first-year college space weather education on a global scale. Application to ground based data such as that contained in the Baryon Oscillation Spectroscopic Survey is discussed.

  1. Spectroscopic Evidence of Alfvén Wave Damping in the Off-limb Solar Corona

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, G. R., E-mail: girjesh@iucaa.in [Inter-University Centre for Astronomy and Astrophysics, Post Bag-4, Ganeshkhind, Pune 411007 (India)

    2017-02-10

    We investigate the off-limb active-region and quiet-Sun corona using spectroscopic data. The active region is clearly visible in several spectral lines formed in the temperature range of 1.1–2.8 MK. We derive the electron number density using the line ratio method, and the nonthermal velocity in the off-limb region up to the distance of 140 Mm. We compare density scale heights derived from several spectral line pairs with expected scale heights per the hydrostatic equilibrium model. Using several isolated and unblended spectral line profiles, we estimate nonthermal velocities in the active region and quiet Sun. Nonthermal velocities obtained from warm lines in the active region first show an increase and then later either a decrease or remain almost constant with height in the far off-limb region, whereas nonthermal velocities obtained from hot lines show consistent decrease. However, in the quiet-Sun region, nonthermal velocities obtained from various spectral lines show either a gradual decrease or remain almost constant with height. Using these obtained parameters, we further calculate Alfvén wave energy flux in both active and quiet-Sun regions. We find a significant decrease in wave energy fluxes with height, and hence provide evidence of Alfvén wave damping. Furthermore, we derive damping lengths of Alfvén waves in the both regions and find them to be in the range of 25–170 Mm. Different damping lengths obtained at different temperatures may be explained as either possible temperature-dependent damping or by measurements obtained in different coronal structures formed at different temperatures along the line of sight. Temperature-dependent damping may suggest some role of thermal conduction in the damping of Alfvén waves in the lower corona.

  2. Calibration of solar radiation measuring instruments. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bahm, R J; Nakos, J C

    1979-11-01

    A review of solar radiation measurement of instruments and some types of errors is given; and procedures for calibrating solar radiation measuring instruments are detailed. An appendix contains a description of various agencies who perform calibration of solar instruments and a description of the methods they used at the time this report was prepared. (WHK)

  3. Spectroscopic metrology for isotope composition measurements and transfer standards

    Science.gov (United States)

    Anyangwe Nwaboh, Javis; Balslev-Harder, David; Kääriäinen, Teemu; Richmond, Craig; Manninen, Albert; Mohn, Joachim; Kiseleva, Maria; Petersen, Jan C.; Werhahn, Olav; Ebert, Volker

    2017-04-01

    The World Meteorological Organization (WMO) has identified greenhouse gases such as CO2, CH4 and N2O as critical for global climate monitoring. Other molecules such as CO that has an indirect effect of enhancing global warming are also monitored. WMO has stated compatibility goals for atmospheric concentration and isotope ratio measurements of these gases, e.g. 0.1 ppm for CO2 concentration measurements in the northern hemisphere and 0.01 ‰ for δ13C-CO2. For measurements of the concentration of greenhouse gases, gas analysers are typically calibrated with static gas standards e.g. traceable to the WMO scale or to the International System of Units (SI) through a national metrology institute. However, concentrations of target components, e.g. CO, in static gas standards have been observed to drift, and typically the gas matrix as well as the isotopic composition of the target component does not always reflect field gas composition, leading to deviations of the analyser response, even after calibration. The deviations are dependent on the measurement technique. To address this issue, part of the HIGHGAS (Metrology for high-impact greenhouse gases) project [1] focused on the development of optical transfer standards (OTSs) for greenhouse gases, e.g. CO2 and CO, potentially complementing gas standards. Isotope ratio mass spectrometry (IRMS) [2] is currently used to provide state-of-the-art high precision (in the 0.01 ‰ range) measurements for the isotopic composition of greenhouse gases. However, there is a need for field-deployable techniques such as optical isotope ratio spectroscopy (OIRS) that can be combined with metrological measurement methods. Within the HIGHGAS project, OIRS methods and procedures based on e.g. cavity enhanced spectroscopy (CES) and tunable diode laser absorption spectroscopy (TDLAS), matched to metrological principles have been established for the measurement of 13C/12C and 18O/16O ratios in CO2, 15N/14N ratios in N2O, and 13C/12C and 2H

  4. Measuring FeO variation using astronomical spectroscopic observations

    Directory of Open Access Journals (Sweden)

    S. Unterguggenberger

    2017-03-01

    respectively. However, a comparison between the modelled O3 in the upper mesosphere and measurements of O3 made with the SABER satellite instrument suggests that these quantum yields may be a factor of ∼ 2 smaller.

  5. Spectroscopic measurements of an H- ion source discharge

    International Nuclear Information System (INIS)

    Keller, R.; Smith, H.V. Jr.

    1985-01-01

    Spectral emission lines from an H - Penning surface-plasma source (SPS), the 4X source, are examined in the visible and near ultraviolet. Electron distribution temperatures are deduced from integral line-strength measurements. These temperatures are surprisingly low, about 0.5 eV. Electron density values of about 1.5 x 10 14 cm -3 and H-atom energies between 2 and 2.6 eV are determined from the measured Balmer-line profiles. Assuming the H - energy is identical to the H-atom energy, an emittance limit of 0.006 π x cm x mrad is deduced for this source with a 5.4-mm aperture

  6. Spectroscopic and bolometric measurements of radiation loss in DIVA

    International Nuclear Information System (INIS)

    Shiho, Makoto; Odajima, Kazuo; Sugie, Tatsuo; Maeda, Hikosuke; Kasai, Satoshi

    1977-11-01

    Radiation loss due to low- and high-z impurities in DIVA (JFT-2a) was measured by means of a calibrated 3m grazing incidence vacuum monochromater and a calibrated pyroelectric detector. The following results were obtained: 1) Radiation loss power due to low-z impurities becomes insignificant by using clean surfaces for the vacuum wall. 2) Radiation loss power due to pseudo continuum from high-z impurities has influence on the energy balance of the confined plasma. 3) The divertor reduces the radiation loss by a factor of about 3. (auth.)

  7. Spectroscopic Measurements of Impurity Spectra on the EAST Tokamak

    International Nuclear Information System (INIS)

    Fu Jia; Li Yingying; Shi Yuejiang; Wang Fudi; Zhang Wei; Lv Bo; Huang Juan; Wan Baonian; Zhou Qian

    2012-01-01

    Ultraviolet (UV) and visible impurity spectra (200∼750 nm) are commonly used to study plasma and wall interactions in magnetic fusion plasmas. Two optical multi-channel analysis (OMA) systems have been installed for the UV-visible spectrum measurement on EAST. These two OMA systems are both equipped with the Czerny-Turner (C-T) type spectrometer. The upper vacuum vessel and inner divertor baffle can be viewed simultaneously through two optical lenses. The OMA1 system is mainly used for multi-impurity lines radiation measurement. A 280 nm wavelength range can be covered by a 300 mm focal length spectrometer equipped with a 300 grooves/mm grating. The Dα/Hα line shapes can be resolved by the OMA2 system. The focal length is 750 mm. The spectral resolution can be up to 0.01 nm using a 1800 grooves/mm grating. The impurity behaviour and hydrogen ratio evolution after boroniztion, lithium coating, and siliconization are compared. Lithium coating has shown beneficial effects on the reduction of edge recycling and low Z impurity (C, O) influx. The impurity expelling effect of the divertor configuration is also briefly discussed through multi-channels observation of OMA1 system. (magnetically confined plasma)

  8. Characterization of μc-Si:H/a-Si:H tandem solar cell structures by spectroscopic ellipsometry

    International Nuclear Information System (INIS)

    Murata, Daisuke; Yuguchi, Tetsuya; Fujiwara, Hiroyuki

    2014-01-01

    In order to perform the structural characterization of Si thin-film solar cells having submicron-size rough textured surfaces, we have developed an optical model that can be utilized for the spectroscopic ellipsometry (SE) analysis of a multilayer solar cell structure consisting of hydrogenated amorphous silicon (a-Si:H) and microcrystalline silicon (μc-Si:H) layers fabricated on textured SnO 2 :F substrates. To represent the structural non-uniformity in the textured structure, the optical response has been calculated from two regions with different thicknesses of the Si layers. Moreover, in the optical model, the interface layers are modeled by multilayer structures assuming two-phase composites and the volume fractions of the phases in the layers are controlled by the structural curvature factor. The polarized reflection from the μc-Si:H layer that shows extensive surface roughening during the growth has also been modeled. In this study, a state-of-the-art solar cell structure with the textured μc-Si:H (2000 nm)/ZnO (100 nm)/a-Si:H (200 nm)/SnO 2 :F/glass substrate structure has been characterized. The μc-Si:H/a-Si:H textured structure deduced from our SE analysis shows remarkable agreement with that observed by transmission electron microscopy. From the above results, we have demonstrated the high-precision characterization of highly-textured μc-Si:H/a-Si:H solar cell structures. - Highlights: • Characterization of textured μc-Si:H/a-Si:H solar cell structures by ellipsometry • A new optical model using surface area and multilayer models • High precision characterization of submicron-range rough interface structures

  9. Measurement of solar radiation at the Earth's surface

    Science.gov (United States)

    Bartman, F. L.

    1982-01-01

    The characteristics of solar energy arriving at the surface of the Earth are defined and the history of solar measurements in the United States presented. Radiation and meteorological measurements being made at solar energy meteorological research and training sites and calibration procedures used there are outlined. Data illustrating the annual variation in daily solar radiation at Ann Arbor, Michigan and the diurnal variation in radiation at Albuquerque, New Mexico are presented. Direct normal solar radiation received at Albuquerque is contrasted with that received at Maynard, Massachusetts. Average measured global radiation for a period of one year for four locations under clear skies, 50% cloud cover, and 100% cloud cover is given and compared with the solar radiation at the top of the atmosphere. The May distribution of mean daily direct solar radiation and mean daily global solar radiation over the United States is presented. The effects of turbidity on the direct and circumsolar radiation are shown.

  10. Impedance Spectroscopic Investigation of the Degraded Dye-Sensitized Solar Cell due to Ageing

    Directory of Open Access Journals (Sweden)

    Parth Bhatt

    2016-01-01

    Full Text Available This paper investigates the effect of ageing on the performance of dye-sensitized solar cells (DSCs. The electrical characterization of fresh and degraded DSCs is done under AM1.5G spectrum and the current density-voltage (J-V characteristics are analyzed. Short circuit current density (JSC decreases significantly whereas a noticeable increase in open circuit voltage is observed. These results have been further investigated electroanalytically using electrochemical impedance spectroscopy (EIS. An increase in net resistance results in a lower JSC for the degraded DSC. This decrease in current is mainly due to degradation of TiO2-dye interface, which is observed from light and dark J-V characteristics and is further confirmed by EIS measurements. A reduction in the chemical capacitance of the degraded DSC is observed, which is responsible for the shifting of Fermi level with respect to conduction band edge that further results in an increase of open circuit voltage for the degraded DSC. It is also confirmed from EIS that the degradation leads to a better contact formation between the electrolyte and Pt electrode, which improves the fill factor of the DSC. But the recombination throughout the DSC is found to increase along with degradation. This study suggests that the DSC should be used under low illumination conditions and around room temperature for a longer life.

  11. Spectroscopic measurement of the electric field in a helium plasma jet

    NARCIS (Netherlands)

    Hofmans, M.; Sobota, A.

    2017-01-01

    The electric field in a plasma jet is measured spectroscopically utilizing the Stark-effect. A cold atmospheric pressure helium plasma jet is used, which operates at a μs-pulsed applied voltage of 6 kV, a frequency of 5 kHz and with a helium flow of 1.5 slm. Due to the electric field in the jet, the

  12. Calculating the diffuse solar radiation in regions without solar radiation measurements

    International Nuclear Information System (INIS)

    Li, Huashan; Bu, Xianbiao; Long, Zhen; Zhao, Liang; Ma, Weibin

    2012-01-01

    Correlations for calculating diffuse solar radiation can be classified into models with global solar radiation (H-based method) and without it (Non-H method). The objective of the present study is to compare the performance of H-based and Non-H methods for calculating the diffuse solar radiation in regions without solar radiation measurements. The comparison is carried out at eight meteorological stations in China focusing on the monthly average daily diffuse solar radiation. Based on statistical error tests, the results show that the Non-H method that includes other readily available meteorological elements gives better estimates. Therefore, it can be concluded that the Non-H method is more appropriate than the H-based one for calculating the diffuse solar radiation in regions without solar radiation measurements. -- Highlights: ► Methods for calculating diffuse solar radiation in regions without solar radiation measurements are investigated. ► Diffuse solar radiation models can be classified into two groups according to global solar radiation. ► Two approaches are compared at the eight meteorological stations in China. ► The method without global solar radiation is recommended.

  13. High temperature and high pressure gas cell for quantitative spectroscopic measurements

    DEFF Research Database (Denmark)

    Christiansen, Caspar; Stolberg-Rohr, Thomine; Fateev, Alexander

    2016-01-01

    A high temperature and high pressure gas cell (HTPGC) has been manufactured for quantitative spectroscopic measurements in the pressure range 1-200 bar and temperature range 300-1300 K. In the present work the cell was employed at up to 100 bar and 1000 K, and measured absorption coefficients...... of a CO2-N2 mixture at 100 bar and 1000 K are revealed for the first time, exceeding the high temperature and pressure combinations previously reported. This paper discusses the design considerations involved in the construction of the cell and presents validation measurements compared against simulated...

  14. ANALYSIS OF MEASURED AND MODELED SOLAR RADIATION AT THE TARS SOLAR HEATING PLANT IN DENMARK

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2017-01-01

    , such as solar radiation, inlet and outlet temperature for the solar collector field, flow rate and pressure, ambient temperature, Wind speed and wind direction were measured. Global horizontal radiation, direct normal irradiation (DNI) and total radiation on the tilted collector plane of the flat plate...... collector field have been measured in Tars solar heating plant. To determine the accuracy of modeled and measured solar radiation in Tars solar heating plant, monthly comparisons of measured and calculated radiation using 6 empirical models have been carried out. Comparisons of measured and modeled total......A novel combined solar heating plant with tracking parabolic trough collectors (PTC) and flat plate collectors (FPC) has been constructed and put into operation in Tars, 30 km north of Aalborg, Denmark in August 2015. To assess the operation performance of the plant, detailed parameters...

  15. Evaluation of spectroscopic modeling for iron ions and study on non-equilibrium ionization phenomena for solar and LHD plasmas

    International Nuclear Information System (INIS)

    Watanabe, Tetsuya; Hara, Hirohisa; Yamamoto, Norimasa; Kato, Daiji; Sakaue, Hiroyuki A.; Murakami, Izumi

    2013-01-01

    Spectroscopic observations of EUV emission lines in the transition region (TR) and the corona provide unique information on physical conditions in the outer atmosphere of the Sun. The EUV Imaging Spectrometer (EIS) on board the Hinode satellite is capable of observing, for the first time in EUV, spectra and monochromatic images of plasmas in the solar TR and corona; these plasmas could possibly be in non-ionization-equilibrium conditions. EIS observes over two-wavelength bands of 170 - 210 Å and 250 - 290 Å, with typical time-resolutions of 1 - 10 seconds. Iron line emissions emerging from these wavelengths reveal that dynamic plasma accelerations and heating take place in the solar atmosphere. On the other hand, the tracer-encapsulated-pellet (TESPEL) experiments provide spectral information of EUV emission lines from iron ions produced in the Large Helical Device (LHD). Relatively cool plasmas with electron temperatures similar to those of the solar corona can be generated by controlling the neutral beam injector (NBI) system. A time-dependent collisional radiative (CR) model for elemental iron is developed as a common tool to diagnose temperatures and densities of those plasmas in the Sun and in LHD; no systematic model yet exists for iron ions in the L- and M-shell ionization stages, which are very important for coronal plasma diagnostics. Adopting the best available theoretical calculations, as well as generating the experimental data, we improve the atomic parameters of highly charged iron ions, and these results are used to extract more accurate diagnostic information out of the EIS spectra. (author)

  16. Measurements of impurity spectra using UV/visible spectroscopic system in a GAMMA 10 plasma

    International Nuclear Information System (INIS)

    Matama, K.; Yoshikawa, M.; Kobayashi, T.; Kubota, Y.; Cho, T.

    2006-01-01

    Impurity spectra have been measured and identified using a newly designed ultraviolet and visible (UV/visible) spectroscopic system in the tandem mirror GAMMA 10. It is constructed using two spectrometers to obtain an entire wavelength range of UV/visible impurity spectra with a high wavelength resolution in one plasma shot. We successfully obtained the emission intensities of the radiation spectra in detail and information on the time-varying population densities of the impurities. We evaluate radiation loss from the GAMMA 10 plasma in the UV/visible range; further we estimate the electron density and temperature after applying the measured spectral intensity to a collisional-radiative model

  17. X-ray spectroscopic measurements of dielectronic recombination of highly charged krypton ions

    International Nuclear Information System (INIS)

    Biedermann, C.; Fuchs, T.; Liebisch, P.; Radtke, R.; Behar, E.; Doron, R.

    1999-01-01

    We have performed X-ray spectroscopic measurements of the dielectronic recombination (DR) resonance strengths for the KLn (n = 2, .., 5) series of He-, Li-, and Be-like krypton ions. The ions were produced with an electron beam ion trap, and the strengths were obtained from a fit procedure that compares the experimental excitation function for DR to theory. The results agree well with the predictions. By looking at the KLL resonance, the time evolution of different krypton charge states was measured with this technique and compared with a model of the trap inventory. (orig.)

  18. Spectroscopic Studies of Solar Corona VI: Trend in Line-width ...

    Indian Academy of Sciences (India)

    cm coronagraph at the Norikura Solar Observatory on several days during the years 1997–2004. The Coude type .... Top-most panel shows the variation of FWHM of the 6374 Е and 5303 Е emission lines with height above the limb when all ...

  19. Spectroscopic and impedance studies of reverse biased degraded dye solar cells

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2011-03-01

    Full Text Available The work that is presented here is focused on the results that were obtained during studies of the performance of Dye Solar Cells under certain reverse bias conditions. This reverse voltage could permanently modify or damage a cell...

  20. Measuring solar reflectance - Part II: Review of practical methods

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul [Heat Island Group, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

    2010-09-15

    A companion article explored how solar reflectance varies with surface orientation and solar position, and found that clear sky air mass 1 global horizontal (AM1GH) solar reflectance is a preferred quantity for estimating solar heat gain. In this study we show that AM1GH solar reflectance R{sub g,0} can be accurately measured with a pyranometer, a solar spectrophotometer, or an updated edition of the Solar Spectrum Reflectometer (version 6). Of primary concern are errors that result from variations in the spectral and angular distributions of incident sunlight. Neglecting shadow, background and instrument errors, the conventional pyranometer technique can measure R{sub g,0} to within 0.01 for surface slopes up to 5:12 [23 ], and to within 0.02 for surface slopes up to 12:12 [45 ]. An alternative pyranometer method minimizes shadow errors and can be used to measure R{sub g,0} of a surface as small as 1 m in diameter. The accuracy with which it can measure R{sub g,0} is otherwise comparable to that of the conventional pyranometer technique. A solar spectrophotometer can be used to determine R{sub g,0}{sup *}, a solar reflectance computed by averaging solar spectral reflectance weighted with AM1GH solar spectral irradiance. Neglecting instrument errors, R{sub g,0}{sup *} matches R{sub g,0} to within 0.006. The air mass 1.5 solar reflectance measured with version 5 of the Solar Spectrum Reflectometer can differ from R{sub g,0}{sup *} by as much as 0.08, but the AM1GH output of version 6 of this instrument matches R{sub g,0}{sup *} to within about 0.01. (author)

  1. SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems

    International Nuclear Information System (INIS)

    Eisenstein, Daniel J.; Weinberg, David H.; Agol, Eric; Aihara, Hiroaki; Prieto, Carlos Allende; Anderson, Scott F.; Arns, James A.; Aubourg, Eric; Bailey, Stephen; Balbinot, Eduardo; Barkhouser, Robert

    2011-01-01

    Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. The Baryon Oscillation Spectroscopic Survey (BOSS) will measure redshifts of 1.5 million massive galaxies and Lyα forest spectra of 150,000 quasars, using the baryon acoustic oscillation (BAO) feature of large scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z 5 evolved, late-type stars, measuring separate abundances for ∼ 15 elements per star and creating the first high-precision spectroscopic survey of all Galactic stellar populations (bulge, bar, disks, halo) with a uniform set of stellar tracers and spectral diagnostics. The Multi-object APO Radial Velocity Large-area Survey (MARVELS) will monitor radial velocities of more than 8000 FGK stars with the sensitivity and cadence (10-40 m s -1 , ∼ 24 visits per star) needed to detect giant planets with periods up to two years, providing an unprecedented data set for understanding the formation and dynamical evolution of giant planet systems. As of January 2011, SDSS-III has obtained spectra of more than 240,000 galaxies, 29,000 z (ge) 2.2 quasars, and 140,000 stars, including 74,000 velocity measurements of 2580 stars for MARVELS. In keeping with SDSS tradition, SDSS-III will provide regular public releases of all its data, beginning with SDSS Data Release 8 (DR8) in January 2011.

  2. SDSS-III: MASSIVE SPECTROSCOPIC SURVEYS OF THE DISTANT UNIVERSE, THE MILKY WAY, AND EXTRA-SOLAR PLANETARY SYSTEMS

    International Nuclear Information System (INIS)

    Eisenstein, Daniel J.; Weinberg, David H.; Agol, Eric; Anderson, Scott F.; Aihara, Hiroaki; Allende Prieto, Carlos; Arns, James A.; Aubourg, Eric; Bailey, Stephen; Balbinot, Eduardo; Barkhouser, Robert; Beers, Timothy C.; Berlind, Andreas A.; Bickerton, Steven J.; Bizyaev, Dmitry; Blanton, Michael R.; Bochanski, John J.; Bolton, Adam S.

    2011-01-01

    Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. In keeping with SDSS tradition, SDSS-III will provide regular public releases of all its data, beginning with SDSS Data Release 8 (DR8), which was made public in 2011 January and includes SDSS-I and SDSS-II images and spectra reprocessed with the latest pipelines and calibrations produced for the SDSS-III investigations. This paper presents an overview of the four surveys that comprise SDSS-III. The Baryon Oscillation Spectroscopic Survey will measure redshifts of 1.5 million massive galaxies and Lyα forest spectra of 150,000 quasars, using the baryon acoustic oscillation feature of large-scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z 5 evolved, late-type stars, measuring separate abundances for ∼15 elements per star and creating the first high-precision spectroscopic survey of all Galactic stellar populations (bulge, bar, disks, halo) with a uniform set of stellar tracers and spectral diagnostics. The Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS) will monitor radial velocities of more than 8000 FGK stars with the sensitivity and cadence (10-40 m s -1 , ∼24 visits per star) needed to detect giant planets with periods up to two years, providing an unprecedented data set for understanding the formation and dynamical evolution of giant planet systems. As of 2011 January, SDSS-III has obtained spectra of more than 240,000 galaxies, 29,000 z ≥ 2.2 quasars, and 140,000 stars, including 74,000 velocity measurements of 2580 stars for MARVELS.

  3. Spectroscopic measurements of soybeans used to parameterize physiological traits in the AgroIBIS ecosystem model

    Science.gov (United States)

    Singh, A.; Serbin, S.; Kucharik, C. J.; Townsend, P. A.

    2014-12-01

    Ecosystem models such AgroIBIS require detailed parameterizations of numerous vegetation traits related to leaf structure, biochemistry and photosynthetic capacity to properly assess plant carbon assimilation and yield response to environmental variability. In general, these traits are estimated from a limited number of field measurements or sourced from the literature, but rarely is the full observed range of variability in these traits utilized in modeling activities. In addition, pathogens and pests, such as the exotic soybean aphid (Aphis glycines), which affects photosynthetic pathways in soybean plants by feeding on phloem and sap, can potentially impact plant productivity and yields. Capturing plant responses to pest pressure in conjunction with environmental variability is of considerable interest to managers and the scientific community alike. In this research, we employed full-range (400-2500 nm) field and laboratory spectroscopy to rapidly characterize the leaf biochemical and physiological traits, namely foliar nitrogen, specific leaf area (SLA) and the maximum rate of RuBP carboxylation by the enzyme RuBisCo (Vcmax) in soybean plants, which experienced a broad range of environmental conditions and soybean aphid pressures. We utilized near-surface spectroscopic remote sensing measurements as a means to capture the spatial and temporal patterns of aphid impacts across broad aphid pressure levels. In addition, we used the spectroscopic data to generate a much larger dataset of key model parameters required by AgroIBIS than would be possible through traditional measurements of biochemistry and leaf-level gas exchange. The use of spectroscopic retrievals of soybean traits allowed us to better characterize the variability of plant responses associated with aphid pressure to more accurately model the likely impacts of soybean aphid on soybeans. Our next steps include the coupling of the information derived from our spectral measurements with the Agro

  4. Optical performance evaluation of a solar furnace by measuring the highly concentrated solar flux

    International Nuclear Information System (INIS)

    Lee, Hyunjin; Chai, Kwankyo; Kim, Jongkyu; Lee, Sangnam; Yoon, Hwanki; Yu, Changkyun; Kang, Yongheack

    2014-01-01

    We evaluated optical performance of a solar furnace in the KIER (Korea Institute of Energy Research) by measuring the highly concentrated solar flux with the flux mapping method. We presented and analyzed optical performance in terms of concentrated solar flux distribution and power distribution. We investigated concentration ratio, stagnation temperature, total power, and concentration accuracy with help of a modeling code based on the ray tracing method and thereby compared with other solar furnaces. We also discussed flux changes by shutter opening angles and by position adjustment of reflector facets. In the course of flux analysis, we provided a better understanding of reference flux measurement for calibration, reflectivity measurement with a portable reflectometer, shadowing area consideration for effective irradiation, as well as accuracy and repeatability of flux measurements. The results in the present study will help proper utilization of a solar furnace by facilitating comparison between flux measurements at different conditions and flux estimation during operation

  5. Attenuated total reflectance Fourier-transform infrared spectroscopic investigation of silicon heterojunction solar cells

    Czech Academy of Sciences Publication Activity Database

    Holovský, Jakub; De Wolf, S.; Jiříček, Petr; Ballif, C.

    2015-01-01

    Roč. 86, č. 7 (2015), , "073108-1"-"073108-6" ISSN 0034-6748 R&D Projects: GA ČR(CZ) GA14-05053S; GA MŠk 7E12029; GA MŠk(CZ) LM2011026 EU Projects: European Commission(XE) 283501 - Fast Track Institutional support: RVO:68378271 Keywords : FTIR * ATR * solar cells Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.336, year: 2015

  6. EVALUATION OF OPPORTUNITIES OF SOLAR ENERGETICS ON THE BASIS OF ACCURATE GROUND-BASED MEASUREMENTS OF SOLAR RADIATION

    Directory of Open Access Journals (Sweden)

    Aculinin A.

    2008-04-01

    Full Text Available Expected quantity of a solar energy received by solar panel is estimated on the basis of accurate measurements of solar radiation in Kishinev. Optimal orientation of solar panels and apparent volume of the electric power generated by solar panels are determined.

  7. Design and testing of an innovative solar radiation measurement device

    International Nuclear Information System (INIS)

    Badran, Omar; Al-Salaymeh, Ahmed; El-Tous, Yousif; Abdala, Wasfi

    2010-01-01

    After review of studies conducted on the solar radiation measuring systems, a new innovative instrument that would help in measuring the accurate solar radiation on horizontal surfaces has been designed and tested. An advanced instrument with ease of use and high precision that would enable the user to take the readings in terms of solar intensity (W/m 2 ) has been tested. Also, the innovative instrument can record instantaneous readings of the solar intensities as well as the averages value of the solar radiation flux during certain periods of time. The instrument based in its design on being programmed by programmable interfacing controller (PIC). Furthermore, the power supply circuit is fed by the solar energy cells and does not need an external power source.

  8. Model representations of kerogen structures: An insight from density functional theory calculations and spectroscopic measurements.

    Science.gov (United States)

    Weck, Philippe F; Kim, Eunja; Wang, Yifeng; Kruichak, Jessica N; Mills, Melissa M; Matteo, Edward N; Pellenq, Roland J-M

    2017-08-01

    Molecular structures of kerogen control hydrocarbon production in unconventional reservoirs. Significant progress has been made in developing model representations of various kerogen structures. These models have been widely used for the prediction of gas adsorption and migration in shale matrix. However, using density functional perturbation theory (DFPT) calculations and vibrational spectroscopic measurements, we here show that a large gap may still remain between the existing model representations and actual kerogen structures, therefore calling for new model development. Using DFPT, we calculated Fourier transform infrared (FTIR) spectra for six most widely used kerogen structure models. The computed spectra were then systematically compared to the FTIR absorption spectra collected for kerogen samples isolated from Mancos, Woodford and Marcellus formations representing a wide range of kerogen origin and maturation conditions. Limited agreement between the model predictions and the measurements highlights that the existing kerogen models may still miss some key features in structural representation. A combination of DFPT calculations with spectroscopic measurements may provide a useful diagnostic tool for assessing the adequacy of a proposed structural model as well as for future model development. This approach may eventually help develop comprehensive infrared (IR)-fingerprints for tracing kerogen evolution.

  9. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    OpenAIRE

    Cheng, X.; Ding, M. D.

    2016-01-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe XXI 1354.08 A forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of $\\ge$1000 km s$^{-1}$ and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The EUV images at the 131 A and 94 A passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot c...

  10. The inductively coupled plasma as a source for the measurement of fundamental spectroscopic constants

    International Nuclear Information System (INIS)

    Farnsworth, P.B.

    1993-01-01

    Inductively coupled plasmas (ICPs) are stable, robust sources for the generation of spectra from neutral and singly ionized atoms. They are used extensively for analytical spectrometry, but have seen limited use for the measurement of fundamental spectroscopic constants. Several properties of the ICP affect its suitability for such fundamental measurements. They include: spatial structure, spectral background, noise characteristics, electron densities and temperatures, and the state of equilibrium in the plasma. These properties are particularly sensitive to the means by which foreign atoms are introduced into the plasma. With some departures from the operating procedures normally used in analytical measurements, the ICP promise to be a useful source for the measurement of fundamental atomic constants. (orig.)

  11. High temperature and high pressure gas cell for quantitative spectroscopic measurements

    International Nuclear Information System (INIS)

    Christiansen, Caspar; Stolberg-Rohr, Thomine; Fateev, Alexander; Clausen, Sønnik

    2016-01-01

    A high temperature and high pressure gas cell (HTPGC) has been manufactured for quantitative spectroscopic measurements in the pressure range 1–200 bar and temperature range 300–1300 K. In the present work the cell was employed at up to 100 bar and 1000 K, and measured absorption coefficients of a CO_2–N_2 mixture at 100 bar and 1000 K are revealed for the first time, exceeding the high temperature and pressure combinations previously reported. This paper discusses the design considerations involved in the construction of the cell and presents validation measurements compared against simulated spectra, as well as published experimental data. - Highlights: • A ceramic gas cell designed for gas measurements up to 1300 K and 200 bar. • The first recorded absorption spectrum of CO_2 at 1000 K and 101 bar is presented. • Voigt profiles might suffice in the modeling of radiation from CO_2 in combustion.

  12. Quality assessment of solar UV irradiance measured with array spectroradiometers

    Science.gov (United States)

    Egli, Luca; Gröbner, Julian; Hülsen, Gregor; Bachmann, Luciano; Blumthaler, Mario; Dubard, Jimmy; Khazova, Marina; Kift, Richard; Hoogendijk, Kees; Serrano, Antonio; Smedley, Andrew; Vilaplana, José-Manuel

    2016-04-01

    The reliable quantification of ultraviolet (UV) radiation at the earth's surface requires accurate measurements of spectral global solar UV irradiance in order to determine the UV exposure to human skin and to understand long-term trends in this parameter. Array spectroradiometers (ASRMs) are small, light, robust and cost-effective instruments, and are increasingly used for spectral irradiance measurements. Within the European EMRP ENV03 project "Solar UV", new devices, guidelines and characterization methods have been developed to improve solar UV measurements with ASRMs, and support to the end user community has been provided. In order to assess the quality of 14 end user ASRMs, a solar UV intercomparison was held on the measurement platform of the World Radiation Center (PMOD/WRC) in Davos, Switzerland, from 10 to 17 July 2014. The results of the blind intercomparison revealed that ASRMs, currently used for solar UV measurements, show a large variation in the quality of their solar UV measurements. Most of the instruments overestimate the erythema-weighted UV index - in particular at large solar zenith angles - due to stray light contribution in the UV-B range. The spectral analysis of global solar UV irradiance further supported the finding that the uncertainties in the UV-B range are very large due to stray light contribution in this wavelength range. In summary, the UV index may be detected by some commercially available ASRMs within 5 % compared to the world reference spectroradiometer, if well characterized and calibrated, but only for a limited range of solar zenith angles. Generally, the tested instruments are not yet suitable for solar UV measurements for the entire range between 290 and 400 nm under all atmospheric conditions.

  13. Solar cell junction temperature measurement of PV module

    KAUST Repository

    Huang, B.J.; Yang, P.E.; Lin, Y.P.; Lin, B.Y.; Chen, H.J.; Lai, R.C.; Cheng, J.S.

    2011-01-01

    The present study develops a simple non-destructive method to measure the solar cell junction temperature of PV module. The PV module was put in the environmental chamber with precise temperature control to keep the solar PV module as well

  14. Measurement of solar energy radiation in Abu Dhabi, UAE

    International Nuclear Information System (INIS)

    Islam, M.D.; Kubo, I.; Ohadi, M.; Alili, A.A.

    2009-01-01

    This paper presents data on measurement of actual solar radiation in Abu Dhabi (24.43 deg. N, 54.45 deg. E). Global solar radiation and surface temperatures were measured and analyzed for one complete year. High resolution, real-time solar radiation and other meteorological data were collected and processed. Daily and monthly average solar radiation values were calculated from the one-minute average recorded values. The highest daily and monthly mean solar radiation values were 369 and 290 W/m 2 , respectively. The highest one-minute average daily solar radiation was 1041 W/m 2 . Yearly average daily energy input was 18.48 MJ/m 2 /day. Besides the global solar radiation, the daily and monthly average clearness indexes along with temperature variations are discussed. When possible, global solar energy radiation and some meteorological data are compared with corresponding data in other Arab state capitals. The data collected indicate that Abu Dhabi has a strong potential for solar energy capture

  15. Measurement of solar energy radiation in Abu Dhabi, UAE

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M.D.; Kubo, I.; Ohadi, M.; Alili, A.A. [Department of Mechanical Engineering, The Petroleum Institute, Abu Dhabi, P.O. Box 2533 (United Arab Emirates)

    2009-04-15

    This paper presents data on measurement of actual solar radiation in Abu Dhabi (24.43 N, 54.45 E). Global solar radiation and surface temperatures were measured and analyzed for one complete year. High resolution, real-time solar radiation and other meteorological data were collected and processed. Daily and monthly average solar radiation values were calculated from the one-minute average recorded values. The highest daily and monthly mean solar radiation values were 369 and 290 W/m{sup 2}, respectively. The highest one-minute average daily solar radiation was 1041 W/m{sup 2}. Yearly average daily energy input was 18.48 MJ/m{sup 2}/day. Besides the global solar radiation, the daily and monthly average clearness indexes along with temperature variations are discussed. When possible, global solar energy radiation and some meteorological data are compared with corresponding data in other Arab state capitals. The data collected indicate that Abu Dhabi has a strong potential for solar energy capture. (author)

  16. Confocal spectroscopic imaging measurements of depth dependent hydration dynamics in human skin in-vivo

    Science.gov (United States)

    Behm, P.; Hashemi, M.; Hoppe, S.; Wessel, S.; Hagens, R.; Jaspers, S.; Wenck, H.; Rübhausen, M.

    2017-11-01

    We present confocal spectroscopic imaging measurements applied to in-vivo studies to determine the depth dependent hydration profiles of human skin. The observed spectroscopic signal covers the spectral range from 810 nm to 2100 nm allowing to probe relevant absorption signals that can be associated with e.g. lipid and water-absorption bands. We employ a spectrally sensitive autofocus mechanism that allows an ultrafast focusing of the measurement spot on the skin and subsequently probes the evolution of the absorption bands as a function of depth. We determine the change of the water concentration in m%. The water concentration follows a sigmoidal behavior with an increase of the water content of about 70% within 5 μm in a depth of about 14 μm. We have applied our technique to study the hydration dynamics of skin before and after treatment with different concentrations of glycerol indicating that an increase of the glycerol concentration leads to an enhanced water concentration in the stratum corneum. Moreover, in contrast to traditional corneometry we have found that the application of Aluminium Chlorohydrate has no impact to the hydration of skin.

  17. Confocal spectroscopic imaging measurements of depth dependent hydration dynamics in human skin in-vivo

    Directory of Open Access Journals (Sweden)

    P. Behm

    2017-11-01

    Full Text Available We present confocal spectroscopic imaging measurements applied to in-vivo studies to determine the depth dependent hydration profiles of human skin. The observed spectroscopic signal covers the spectral range from 810 nm to 2100 nm allowing to probe relevant absorption signals that can be associated with e.g. lipid and water-absorption bands. We employ a spectrally sensitive autofocus mechanism that allows an ultrafast focusing of the measurement spot on the skin and subsequently probes the evolution of the absorption bands as a function of depth. We determine the change of the water concentration in m%. The water concentration follows a sigmoidal behavior with an increase of the water content of about 70% within 5 μm in a depth of about 14 μm. We have applied our technique to study the hydration dynamics of skin before and after treatment with different concentrations of glycerol indicating that an increase of the glycerol concentration leads to an enhanced water concentration in the stratum corneum. Moreover, in contrast to traditional corneometry we have found that the application of Aluminium Chlorohydrate has no impact to the hydration of skin.

  18. Spectroscopic measurements of plasma temperatures and electron number density in a uranium hollow cathode discharge lamp

    International Nuclear Information System (INIS)

    Shah, M.L.; Suri, B.M.; Gupta, G.P.

    2015-01-01

    The HCD (Hollow Cathode Discharge) lamps have been used as a source of free atoms of any metal, controllable by direct current in the lamp. The plasma parameters including neutral species temperature, atomic excitation temperature and electron number density in a see-through type, homemade uranium hollow cathode discharge lamp with neon as a buffer gas have been investigated using optical emission spectroscopic techniques. The neutral species temperature has been measured using the Doppler broadening of a neon atomic spectral line. The atomic excitation temperature has been measured using the Boltzmann plot method utilizing uranium atomic spectral lines. The electron number density has been determined from the Saha-Boltzmann equation utilizing uranium atomic and ionic spectral lines. To the best of our knowledge, all these three plasma parameters are simultaneously measured for the first time in a uranium hollow cathode discharge lamp

  19. Spectroscopic measurements of plasma emission light for plasma-based acceleration experiments

    International Nuclear Information System (INIS)

    Filippi, F.; Mostacci, A.; Palumbo, L.; Anania, M.P.; Biagioni, A.; Chiadroni, E.; Ferrario, M.; Cianchi, A.; Zigler, A.

    2016-01-01

    Advanced particle accelerators are based on the excitation of large amplitude plasma waves driven by either electron or laser beams. Future experiments scheduled at the SPARC-LAB test facility aim to demonstrate the acceleration of high brightness electron beams through the so-called resonant Plasma Wakefield Acceleration scheme in which a train of electron bunches (drivers) resonantly excites wakefields into a preformed hydrogen plasma; the last bunch (witness) injected at the proper accelerating phase gains energy from the wake. The quality of the accelerated beam depends strongly on plasma density and its distribution along the acceleration length. The measurements of plasma density of the order of 10 16 –10 17  cm −3 can be performed with spectroscopic measurements of the plasma-emitted light. The measured density distribution for hydrogen filled capillary discharge with both Balmer alpha and Balmer beta lines and shot-to-shot variation are here reported.

  20. Spectroscopic measurements of plasma emission light for plasma-based acceleration experiments

    Science.gov (United States)

    Filippi, F.; Anania, M. P.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Ferrario, M.; Mostacci, A.; Palumbo, L.; Zigler, A.

    2016-09-01

    Advanced particle accelerators are based on the excitation of large amplitude plasma waves driven by either electron or laser beams. Future experiments scheduled at the SPARC_LAB test facility aim to demonstrate the acceleration of high brightness electron beams through the so-called resonant Plasma Wakefield Acceleration scheme in which a train of electron bunches (drivers) resonantly excites wakefields into a preformed hydrogen plasma; the last bunch (witness) injected at the proper accelerating phase gains energy from the wake. The quality of the accelerated beam depends strongly on plasma density and its distribution along the acceleration length. The measurements of plasma density of the order of 1016-1017 cm-3 can be performed with spectroscopic measurements of the plasma-emitted light. The measured density distribution for hydrogen filled capillary discharge with both Balmer alpha and Balmer beta lines and shot-to-shot variation are here reported.

  1. Evaluating the influence of particulate matter on spectroscopic measurements of a combusting flow

    Science.gov (United States)

    Herlan, Jonathan; Murray, Nathan

    2017-11-01

    An adiabatic table-top burner has been used to develop a method for estimating the temperature and concentration of OH in a measurement volume of a non-premixed, hydrogen-air flame. The estimation method uses a nonlinear curve-fitting routine to compare experimental absorption spectra with a model derived, using statistical mechanics, from the Beer-Lambert law. With the aim of applying this method to the analysis of rocket exhaust plumes, this study evaluates whether or not it provides faithful estimates of temperature and OH concentration when the combusting flow contains particulate matter-such as soot or tracers used for particle image velocimetry (PIV) measurements. The hydrogen line of the table-top burner will be seeded with alumina, Al2O3, particles and their influence on spectroscopic measurements elucidated. The authors wish to thank Mr. Bernard Jansen for his support and insight in laboratory activities.

  2. Measuring solar reflectance - Part I: Defining a metric that accurately predicts solar heat gain

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul [Heat Island Group, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

    2010-09-15

    Solar reflectance can vary with the spectral and angular distributions of incident sunlight, which in turn depend on surface orientation, solar position and atmospheric conditions. A widely used solar reflectance metric based on the ASTM Standard E891 beam-normal solar spectral irradiance underestimates the solar heat gain of a spectrally selective ''cool colored'' surface because this irradiance contains a greater fraction of near-infrared light than typically found in ordinary (unconcentrated) global sunlight. At mainland US latitudes, this metric R{sub E891BN} can underestimate the annual peak solar heat gain of a typical roof or pavement (slope {<=} 5:12 [23 ]) by as much as 89 W m{sup -2}, and underestimate its peak surface temperature by up to 5 K. Using R{sub E891BN} to characterize roofs in a building energy simulation can exaggerate the economic value N of annual cool roof net energy savings by as much as 23%. We define clear sky air mass one global horizontal (''AM1GH'') solar reflectance R{sub g,0}, a simple and easily measured property that more accurately predicts solar heat gain. R{sub g,0} predicts the annual peak solar heat gain of a roof or pavement to within 2 W m{sup -2}, and overestimates N by no more than 3%. R{sub g,0} is well suited to rating the solar reflectances of roofs, pavements and walls. We show in Part II that R{sub g,0} can be easily and accurately measured with a pyranometer, a solar spectrophotometer or version 6 of the Solar Spectrum Reflectometer. (author)

  3. Measuring solar reflectance Part I: Defining a metric that accurately predicts solar heat gain

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul

    2010-05-14

    Solar reflectance can vary with the spectral and angular distributions of incident sunlight, which in turn depend on surface orientation, solar position and atmospheric conditions. A widely used solar reflectance metric based on the ASTM Standard E891 beam-normal solar spectral irradiance underestimates the solar heat gain of a spectrally selective 'cool colored' surface because this irradiance contains a greater fraction of near-infrared light than typically found in ordinary (unconcentrated) global sunlight. At mainland U.S. latitudes, this metric RE891BN can underestimate the annual peak solar heat gain of a typical roof or pavement (slope {le} 5:12 [23{sup o}]) by as much as 89 W m{sup -2}, and underestimate its peak surface temperature by up to 5 K. Using R{sub E891BN} to characterize roofs in a building energy simulation can exaggerate the economic value N of annual cool-roof net energy savings by as much as 23%. We define clear-sky air mass one global horizontal ('AM1GH') solar reflectance R{sub g,0}, a simple and easily measured property that more accurately predicts solar heat gain. R{sub g,0} predicts the annual peak solar heat gain of a roof or pavement to within 2 W m{sup -2}, and overestimates N by no more than 3%. R{sub g,0} is well suited to rating the solar reflectances of roofs, pavements and walls. We show in Part II that R{sub g,0} can be easily and accurately measured with a pyranometer, a solar spectrophotometer or version 6 of the Solar Spectrum Reflectometer.

  4. Solar cell junction temperature measurement of PV module

    KAUST Repository

    Huang, B.J.

    2011-02-01

    The present study develops a simple non-destructive method to measure the solar cell junction temperature of PV module. The PV module was put in the environmental chamber with precise temperature control to keep the solar PV module as well as the cell junction in thermal equilibrium with the chamber. The open-circuit voltage of PV module Voc is then measured using a short pulse of solar irradiation provided by a solar simulator. Repeating the measurements at different environment temperature (40-80°C) and solar irradiation S (200-1000W/m2), the correlation between the open-circuit voltage Voc, the junction temperature Tj, and solar irradiation S is derived.The fundamental correlation of the PV module is utilized for on-site monitoring of solar cell junction temperature using the measured Voc and S at a short time instant with open circuit. The junction temperature Tj is then determined using the measured S and Voc through the fundamental correlation. The outdoor test results show that the junction temperature measured using the present method, Tjo, is more accurate. The maximum error using the average surface temperature Tave as the junction temperature is 4.8 °C underestimation; while the maximum error using the present method is 1.3 °C underestimation. © 2010 Elsevier Ltd.

  5. Solar and terrestrial radiation: methods and measurements

    National Research Council Canada - National Science Library

    Coulson, Kinsell L

    1975-01-01

    ... AND RETRIEVAL SYSTEM, WITHOUT PERMISSION IN WRITING FROM THE PUBLISHER. ACADEMIC PRESS, INC. Ill Fifth Avenue, New York, New York 10003 United Kingdom Edition published by A C A D E M I C PRESS, INC. (LONDON) LTD. 24/28 Oval Road, London NW1 Library of Congress Cataloging in Publication Data Coulson, Kinsell L Solar and terrestrial radiation. Inclu...

  6. The high-resolution extraterrestrial solar spectrum (QASUMEFTS determined from ground-based solar irradiance measurements

    Directory of Open Access Journals (Sweden)

    J. Gröbner

    2017-09-01

    Full Text Available A high-resolution extraterrestrial solar spectrum has been determined from ground-based measurements of direct solar spectral irradiance (SSI over the wavelength range from 300 to 500 nm using the Langley-plot technique. The measurements were obtained at the Izaña Atmospheric Research Centre from the Agencia Estatal de Meteorología, Tenerife, Spain, during the period 12 to 24 September 2016. This solar spectrum (QASUMEFTS was combined from medium-resolution (bandpass of 0.86 nm measurements of the QASUME (Quality Assurance of Spectral Ultraviolet Measurements in Europe spectroradiometer in the wavelength range from 300 to 500 nm and high-resolution measurements (0.025 nm from a Fourier transform spectroradiometer (FTS over the wavelength range from 305 to 380 nm. The Kitt Peak solar flux atlas was used to extend this high-resolution solar spectrum to 500 nm. The expanded uncertainties of this solar spectrum are 2 % between 310 and 500 nm and 4 % at 300 nm. The comparison of this solar spectrum with solar spectra measured in space (top of the atmosphere gave very good agreements in some cases, while in some other cases discrepancies of up to 5 % were observed. The QASUMEFTS solar spectrum represents a benchmark dataset with uncertainties lower than anything previously published. The metrological traceability of the measurements to the International System of Units (SI is assured by an unbroken chain of calibrations leading to the primary spectral irradiance standard of the Physikalisch-Technische Bundesanstalt in Germany.

  7. Infrared spectroscopic measurement of skin hydration and sebum levels and comparison to corneometer and sebumeter

    Science.gov (United States)

    Ezerskaia, Anna; Pereira, S. F.; Urbach, H. P.; Varghese, Babu

    2016-05-01

    Skin health characterized by a system of water and lipids in Stratum Corneum provide protection from harmful external elements and prevent trans-epidermal water loss. Skin hydration (moisture) and sebum (skin surface lipids) are considered to be important factors in skin health; a right balance between these components is an indication of skin health and plays a central role in protecting and preserving skin integrity. In this manuscript we present an infrared spectroscopic method for simultaneous and quantitative measurement of skin hydration and sebum levels utilizing differential detection with three wavelengths 1720, 1750, and 1770 nm, corresponding to the lipid vibrational bands that lie "in between" the prominent water absorption bands. The skin sebum and hydration values on the forehead under natural conditions and its variations to external stimuli were measured using our experimental set-up. The experimental results obtained with the optical set-up show good correlation with the results obtained with the commercially available instruments Corneometer and Sebumeter.

  8. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    Science.gov (United States)

    Cheng, X.; Ding, M. D.

    2016-05-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s-1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (˜11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  9. SPECTROSCOPIC DIAGNOSTICS OF SOLAR MAGNETIC FLUX ROPES USING IRON FORBIDDEN LINE

    International Nuclear Information System (INIS)

    Cheng, X.; Ding, M. D.

    2016-01-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s"−"1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (∼11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  10. SPECTROSCOPIC DIAGNOSTICS OF SOLAR MAGNETIC FLUX ROPES USING IRON FORBIDDEN LINE

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, X.; Ding, M. D., E-mail: xincheng@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

    2016-05-20

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s{sup −1} and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (∼11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  11. Optimized spectroscopic scheme for enhanced precision CO measurements with applications to urban source attribution

    Science.gov (United States)

    Nottrott, A.; Hoffnagle, J.; Farinas, A.; Rella, C.

    2014-12-01

    Carbon monoxide (CO) is an urban pollutant generated by internal combustion engines which contributes to the formation of ground level ozone (smog). CO is also an excellent tracer for emissions from mobile combustion sources. In this work we present an optimized spectroscopic sampling scheme that enables enhanced precision CO measurements. The scheme was implemented on the Picarro G2401 Cavity Ring-Down Spectroscopy (CRDS) analyzer which measures CO2, CO, CH4 and H2O at 0.2 Hz. The optimized scheme improved the raw precision of CO measurements by 40% from 5 ppb to 3 ppb. Correlations of measured CO2, CO, CH4 and H2O from an urban tower were partitioned by wind direction and combined with a concentration footprint model for source attribution. The application of a concentration footprint for source attribution has several advantages. The upwind extent of the concentration footprint for a given sensor is much larger than the flux footprint. Measurements of mean concentration at the sensor location can be used to estimate source strength from a concentration footprint, while measurements of the vertical concentration flux are necessary to determine source strength from the flux footprint. Direct measurement of vertical concentration flux requires high frequency temporal sampling and increases the cost and complexity of the measurement system.

  12. 7Be solar neutrino measurement with KamLAND

    Science.gov (United States)

    Gando, A.; Gando, Y.; Hanakago, H.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Ishikawa, H.; Kishimoto, Y.; Koga, M.; Matsuda, R.; Matsuda, S.; Mitsui, T.; Motoki, D.; Nakajima, K.; Nakamura, K.; Obata, A.; Oki, A.; Oki, Y.; Otani, M.; Shimizu, I.; Shirai, J.; Suzuki, A.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B. D.; Yamada, S.; Yamauchi, Y.; Yoshida, H.; Kozlov, A.; Takemoto, Y.; Yoshida, S.; Grant, C.; Keefer, G.; McKee, D. W.; Piepke, A.; Banks, T. I.; Bloxham, T.; Freedman, S. J.; Fujikawa, B. K.; Han, K.; Hsu, L.; Ichimura, K.; Murayama, H.; O'Donnell, T.; Steiner, H. M.; Winslow, L. A.; Dwyer, D.; Mauger, C.; McKeown, R. D.; Zhang, C.; Berger, B. E.; Lane, C. E.; Maricic, J.; Miletic, T.; Learned, J. G.; Sakai, M.; Horton-Smith, G. A.; Tang, A.; Downum, K. E.; Tolich, K.; Efremenko, Y.; Kamyshkov, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Detwiler, J. A.; Enomoto, S.; Heeger, K.; Decowski, M. P.; KamLAND Collaboration

    2015-11-01

    We report a measurement of the neutrino-electron elastic scattering rate of 862 keV 7Be solar neutrinos based on a 165.4 kt d exposure of KamLAND. The observed rate is 582 ±94 (kt d)-1, which corresponds to an 862-keV 7Be solar neutrino flux of (3.26 ±0.52 ) ×109cm-2s-1 , assuming a pure electron-flavor flux. Comparing this flux with the standard solar model prediction and further assuming three-flavor mixing, a νe survival probability of 0.66 ±0.15 is determined from the KamLAND data. Utilizing a global three-flavor oscillation analysis, we obtain a total 7Be solar neutrino flux of (5.82 ±1.02 ) ×109cm-2s-1 , which is consistent with the standard solar model predictions.

  13. Development of Software for Measurement and Analysis of Solar Radiation

    International Nuclear Information System (INIS)

    Mohamad Idris Taib; Abul Adli Anuar; Noor Ezati Shuib

    2015-01-01

    This software was under development using LabVIEW to be using with StellarNet spectrometers system with USB communication to computer. LabVIEW have capabilities in hardware interfacing, graphical user interfacing and mathematical calculation including array manipulation and processing. This software read data from StellarNet spectrometer in real-time and then processed for analysis. Several measurement of solar radiation and analysis have been done. Solar radiation involved mainly infra-red, visible light and ultra-violet. With solar radiation spectrum data, information of weather and suitability of plant can be gathered and analyzed. Furthermore, optimization of utilization and safety precaution of solar radiation can be planned. Using this software, more research and development in utilization and safety of solar radiation can be explored. (author)

  14. Spectroscopic elucidation of energy transfer in hybrid inorganic-biological organisms for solar-to-chemical production.

    Science.gov (United States)

    Kornienko, Nikolay; Sakimoto, Kelsey K; Herlihy, David M; Nguyen, Son C; Alivisatos, A Paul; Harris, Charles B; Schwartzberg, Adam; Yang, Peidong

    2016-10-18

    The rise of inorganic-biological hybrid organisms for solar-to-chemical production has spurred mechanistic investigations into the dynamics of the biotic-abiotic interface to drive the development of next-generation systems. The model system, Moorella thermoacetica-cadmium sulfide (CdS), combines an inorganic semiconductor nanoparticle light harvester with an acetogenic bacterium to drive the photosynthetic reduction of CO 2 to acetic acid with high efficiency. In this work, we report insights into this unique electrotrophic behavior and propose a charge-transfer mechanism from CdS to M. thermoacetica Transient absorption (TA) spectroscopy revealed that photoexcited electron transfer rates increase with increasing hydrogenase (H 2 ase) enzyme activity. On the same time scale as the TA spectroscopy, time-resolved infrared (TRIR) spectroscopy showed spectral changes in the 1,700-1,900-cm -1 spectral region. The quantum efficiency of this system for photosynthetic acetic acid generation also increased with increasing H 2 ase activity and shorter carrier lifetimes when averaged over the first 24 h of photosynthesis. However, within the initial 3 h of photosynthesis, the rate followed an opposite trend: The bacteria with the lowest H 2 ase activity photosynthesized acetic acid the fastest. These results suggest a two-pathway mechanism: a high quantum efficiency charge-transfer pathway to H 2 ase generating H 2 as a molecular intermediate that dominates at long time scales (24 h), and a direct energy-transducing enzymatic pathway responsible for acetic acid production at short time scales (3 h). This work represents a promising platform to utilize conventional spectroscopic methodology to extract insights from more complex biotic-abiotic hybrid systems.

  15. Comparison of solar irradiances measured by SBUV, SME, and rockets

    International Nuclear Information System (INIS)

    Schlesinger, B.M.; Heath, D.F.

    1988-01-01

    Solar Backscatter Ultraviolet (SBUV) measurements of the solar irradiance between 170 and 320 nm have been compared with rocket and Solar Mesosphere Explorer (SME) ultraviolet spectrometer measurements. The SBUV and SME data were those available from the National Space Sciences Data Center (NSSDC). The published rocket measurement are sensitive enough to detect substantial systematic changes with time in other instruments and to check absolute calibration but not sufficiently sensitive to validate claims of changes in the solar ultraviolet irradiance longer than 170 nm. The SBUV irradiances show as systematic decrease with time not seen in the rocket measurements; a correction for this decrease, based on changes between the instrument properties measured in 1980--1981 and those in 1984, is introduced. Ratios of spectra in early 1982 to those in mid-1984, calculated using the SME and SBUV solar irradiances, have been compared with each other asnd with those predicted from Mg 280-nm variations. The scatter and overall structure in the SME spectra from the NSSDC is 3--5%, of the order of or larger than most of the changes predicted by the Mg index. The corrected SBUV ratio and the Mg index prediction for it agree to within 1% such agreement supports a common origin for variations between solar maximum and minimum and those for individual rotations: the degree to which active regions cover the visible hemisphere of the Sun. copyright American Geophysical Union 1988

  16. On the measurements of large scale solar velocity fields

    International Nuclear Information System (INIS)

    Andersen, B.N.

    1985-01-01

    A general mathematical formulation for the correction of the scattered light influence on solar Doppler shift measurements has been developed. This method has been applied to the straylight correction of measurements of solar rotation, limb effect, large scale flows and oscillations. It is shown that neglecting the straylight errors may cause spurious large scale velocity fields, oscillations and erronous values for the solar rotation and limb effect. The influence of active regions on full disc velocity measurements has been studied. It is shown that a 13 day periodicity in the global velocity signal will be introduced by the passage of sunspots over the solar disc. With different types of low resolution apertures, other periodicities may be introduced. Accurate measurements of the center-to-limb velocity shift are presented for a set of magnetic insensitive lines well suited for solar velocity measurements. The absolute wavelenght shifts are briefly discussed. The stronger lines have a ''supergravitational'' shift of 300-400 m/s at the solar limb. The results may be explained by the presence of a 20-25 m/s poleward meridional flow and a latitudinal dependence of the granular parameters. Using a simple model it is shown that the main properites of the observations are explained by a 5% increase in the granular size with latitude. Data presented indicate that the resonance line K I, 769.9 nm has a small but significant limb effect of 125 m/s from center to limb

  17. Optical properties of LiGaS2: an ab initio study and spectroscopic ellipsometry measurement

    International Nuclear Information System (INIS)

    Atuchin, V V; Lin, Z S; Isaenko, L I; Lobanov, S I; Kesler, V G; Kruchinin, V N

    2009-01-01

    Electronic and optical properties of lithium thiogallate crystal, LiGaS 2 , have been investigated by both experimental and theoretical methods. The plane-wave pseudopotential method based on DFT theory has been used for band structure calculations. The electronic parameters of Ga 3d orbitals have been corrected by the DFT+U methods to be consistent with those measured with x-ray photoemission spectroscopy. Evolution of optical constants of LiGaS 2 over a wide spectral range was determined by developed first-principles theory and dispersion curves were compared with optical parameters defined by spectroscopic ellipsometry in the photon energy range 1.2-5.0 eV. Good agreement has been achieved between theoretical and experimental results.

  18. Progress toward a microsecond duration, repetitive, intense-ion beam for active spectroscopic measurements on ITER

    International Nuclear Information System (INIS)

    Davis, H.A.; Bartsch, R.R.; Barnes, C.W.

    1996-01-01

    The authors describe the design of an intense, pulsed, repetitive, neutral beam based on magnetically insulated diode technology for injection into ITER for spectroscopic measurements of thermalizing alpha particle and thermal helium density profiles, ion temperature, plasma rotation, and low Z impurity concentrations in the confinement region. The beam is being developed to enhance low signal-to-noise ratios expected with conventional steady-state ion beams because of severe beam attenuation and intense bremstrahlung emission. A 5 GW (e.g., 100 keV, 50 kA) one-microsecond-duration beam would increase the signal by 10 3 compared to a conventional 5 MW beam with signal-to-noise ratios comparable to those from a chopped conventional beam in one second

  19. In vivo, noninvasive functional measurements of bone sarcoma using diffuse optical spectroscopic imaging

    Science.gov (United States)

    Peterson, Hannah M.; Hoang, Bang H.; Geller, David; Yang, Rui; Gorlick, Richard; Berger, Jeremy; Tingling, Janet; Roth, Michael; Gill, Jonathon; Roblyer, Darren

    2017-12-01

    Diffuse optical spectroscopic imaging (DOSI) is an emerging near-infrared imaging technique that noninvasively measures quantitative functional information in thick tissue. This study aimed to assess the feasibility of using DOSI to measure optical contrast from bone sarcomas. These tumors are rare and pose technical and practical challenges for DOSI measurements due to the varied anatomic locations and tissue depths of presentation. Six subjects were enrolled in the study. One subject was unable to be measured due to tissue contact sensitivity. For the five remaining subjects, the signal-to-noise ratio, imaging depth, optical properties, and quantitative tissue concentrations of oxyhemoglobin, deoxyhemoglobin, water, and lipids from tumor and contralateral normal tissues were assessed. Statistical differences between tumor and contralateral normal tissue were found in chromophore concentrations and optical properties for four subjects. Low signal-to-noise was encountered during several subject's measurements, suggesting increased detector sensitivity will help to optimize DOSI for this patient population going forward. This study demonstrates that DOSI is capable of measuring optical properties and obtaining functional information in bone sarcomas. In the future, DOSI may provide a means to stratify treatment groups and monitor chemotherapy response for this disease.

  20. PRISM: Processing routines in IDL for spectroscopic measurements (installation manual and user's guide, version 1.0)

    Science.gov (United States)

    Kokaly, Raymond F.

    2011-01-01

    This report describes procedures for installing and using the U.S. Geological Survey Processing Routines in IDL for Spectroscopic Measurements (PRISM) software. PRISM provides a framework to conduct spectroscopic analysis of measurements made using laboratory, field, airborne, and space-based spectrometers. Using PRISM functions, the user can compare the spectra of materials of unknown composition with reference spectra of known materials. This spectroscopic analysis allows the composition of the material to be identified and characterized. Among its other functions, PRISM contains routines for the storage of spectra in database files, import/export of ENVI spectral libraries, importation of field spectra, correction of spectra to absolute reflectance, arithmetic operations on spectra, interactive continuum removal and comparison of spectral features, correction of imaging spectrometer data to ground-calibrated reflectance, and identification and mapping of materials using spectral feature-based analysis of reflectance data. This report provides step-by-step instructions for installing the PRISM software and running its functions.

  1. Selective solar absorber emittance measurement at elevated temperature

    Science.gov (United States)

    Giraud, Philémon; Braillon, Julien; Raccurt, Olivier

    2017-06-01

    Durability of solar components for CSP (Concentrated Solar Power Plant) technologies is a key point to lower cost and ensure their large deployment. These technologies concentrated the solar radiation by means of mirrors on a receiver tube where it is collected as thermal energy. The absorbers are submitted to strong environmental constraints and the degradation of their optical properties (emittance and solar absorbance) have a direct impact on performance. The characterization of a material in such condition is complicated and requires advanced apparatuses, and different measurement methods exist for the determination of the two quantities of relevance regarding an absorber, which are its emittance and its solar absorbance. The objective is to develop new optical equipment for measure the emittance of this solar absorber at elevated temperature. In this paper, we present an optical bench developed for emittance measurement on absorbers is conditions of use. Results will be shown, with a discussion of some factors of influence over this measurement and how to control them.

  2. Spectroscopic measurement of target plate erosion in the ASDEX Upgrade divertor

    Energy Technology Data Exchange (ETDEWEB)

    Filed, A R; Garcia-Rosales, C; Lieder, G; Pitcher, C S; Radtke, R [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); ASDEX Upgrade Team

    1996-02-01

    The erosion of the graphite divertor plates in the ASDEX Upgrade tokamak is measured spectroscopically. Spatial profiles of the D{sup 0} and C{sup +} influxes across the outer target plate are determined from measured absolute line intensities. Plasma parameters (n{sub e}, T{sub e}) at the target, which are required to determine the appropriate photon emission efficiencies for these lines, are obtained from an in-vessel reciprocating Langmuir probe above the target plate. Yields for the erosion of the graphite by the incident D{sup +} flux are determined from the ratio of the measured C{sup +} to D{sup 0} fluxes. Over a range of moderate densities the measured yields of {<=} 4% are explicable in terms of physical sputtering alone. Chemical sputtering by low energy Franck-Condon neutrals probably contributes, however, to the total erosion. At higher densities detachment of the plasma from the targets occurs owing to formation of a MARFE near the X point. Under these conditions localized physical sputtering of the targets ceases. The impurity level (Z{sub eff}) is, however, maintained following detachment, indicating a corresponding maintenance of carbon influx, perhaps due to chemical erosion of the total graphite surface and/or an improvement in particle confinement in the detached state. (author). 26 refs, 14 figs, 1 tab.

  3. Determining the Optimum Tilt Angle and Orientation for Solar Energy Collection Based on Measured Solar Radiance Data

    OpenAIRE

    Li, Danny H. W.; Lam, Tony N. T.

    2007-01-01

    A prior requirement to the design of any solar-based conversion systems is the knowledge of optimum orientation and tilt surface at which peak solar energy can be collected. In many parts of the world, however, the solar radiation data for the surfaces of interest are not always available. This paper presents a numerical approach to calculate the solar radiation on sloped planes by integrating the measured sky radiance distributions. The annual total solar yield at different sloped surfaces ...

  4. The solar-like CoRoT target HD 170987: spectroscopic and seismic observations

    DEFF Research Database (Denmark)

    Mathur , S; Karoff, Christoffer

    2010-01-01

    -1200] μHz with a mean large separation of 55.2 ± 0.8 μHz with a probability above 95 % that increases to 55.9 ± 0.2 μHz in a higher frequency range [500-1250] μHz and a rejection level of 1%. A hint of the variation of this quantity with frequency was also found. The rotation period of the star...... is estimated to be around 4.3 days with an inclination axis of i = 50° +20-13. We measured a bolometric amplitude per radial mode in a range [2.4-2.9] ppm around 1000 μHz. Finally we estimate the stellar mass with a grid of models, M = 1.43 ± 0.05 M_sun, the radius, R = 1.96 ± 0.046 R_sun, and the age ~2.4 Gyr....

  5. About Solar Radiation Intensity Measurements and Data Processing

    Directory of Open Access Journals (Sweden)

    MICH-VANCEA Claudiu

    2012-10-01

    Full Text Available Measuring the intensity of solar radiation is one of the directions of investigation necessary for the implementation of photovoltaic systems in a particular geographical area. This can be done by using specific measuring equipment (pyranometer sensors based onthermal or photovoltaic principle. In this paper it is presented a method for measuring solar radiation (which has two main components - direct radiation and diffuse radiation with sensors based on photovoltaic principle. Such data are processed for positioning solarpanels, in order their efficiency to be maximized.

  6. Feasibility study of carbon particles injection by laser ablation to calibrate spectroscopic erosion measurements in Tore Supra

    International Nuclear Information System (INIS)

    Naiim Habib, M.; Mercadier, L.; Marandet, Y.; Delaporte, Ph.; Hernandez, C.; Grisolia, C.; Monier-Garbet, P.

    2011-01-01

    To check if spectroscopic measurements can be used for erosion determination, we propose to inject in the line of sight of the diagnostic, during plasma operation, a known carbon particle source, produced by laser ablation. A first assessment of this technique will be presented in the context of the Tore Supra tokamak.

  7. 2. Basis of measurement of plasma flow. 2.3 Plasma flow measurements. Spectroscopic methods

    International Nuclear Information System (INIS)

    Kado, Shinichiro

    2007-01-01

    The construction of optical system, optical fiber incident system, reciprocal linear dispersion, grating smile and astigmatism of the reflection plane diffraction grating spectrometer are explained in order to measure the plasma flow. The specification of flow measurement and evaluation of 0 point of velocity are stated. For examples of measurements, the fine structures of He II (Δn = 3 - 4) in material and plasma(MAP)-II of Tokyo University, plasma flow measurement by the charge exchange recombination spectroscopy using Large Helical Device and by Zeeman spectroscopy using TRIAM-1M tokamak plasma are stated. (S.Y.)

  8. Solar diurnal anisotropy measured using muons in GRAPES-3 ...

    Indian Academy of Sciences (India)

    The mean energy of muons at sea level is ∼4 GeV with a rel- .... of decays of mesons and muons work against each other resulting in temperature coef- ..... The mean muon rate of 16 modules measured every 15 min for one week interval from .... 4. 8. 12. 16. 20. 24. Hours. Figure 12. Solar diurnal anisotropy measured in ...

  9. Assessment and comparison of methods for solar ultraviolet radiation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Leszczynski, K

    1995-06-01

    In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.).

  10. Assessment and comparison of methods for solar ultraviolet radiation measurements

    International Nuclear Information System (INIS)

    Leszczynski, K.

    1995-06-01

    In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.)

  11. Measuring Solar Radiation Incident on Earth: Solar Constant-3 (SOLCON-3)

    Science.gov (United States)

    Crommelynck, Dominique; Joukoff, Alexandre; Dewitte, Steven

    2002-01-01

    Life on Earth is possible because the climate conditions on Earth are relatively mild. One element of the climate on Earth, the temperature, is determined by the heat exchanges between the Earth and its surroundings, outer space. The heat exchanges take place in the form of electromagnetic radiation. The Earth gains energy because it absorbs solar radiation, and it loses energy because it emits thermal infrared radiation to cold space. The heat exchanges are in balance: the heat gained by the Earth through solar radiation equals the heat lost through thermal radiation. When the balance is perturbed, a temperature change and hence a climate change of the Earth will occur. One possible perturbation of the balance is the CO2 greenhouse effect: when the amount of CO2 in the atmosphere increases, this will reduce the loss of thermal infrared radiation to cold space. Earth will gain more heat and hence the temperature will rise. Another perturbation of the balance can occur through variation of the amount of energy emitted by the sun. When the sun emits more energy, this will directly cause a rise of temperature on Earth. For a long time scientists believed that the energy emitted by the sun was constant. The 'solar constant' is defined as the amount of solar energy received per unit surface at a distance of one astronomical unit (the average distance of Earth's orbit) from the sun. Accurate measurements of the variations of the solar constant have been made since 1978. From these we know that the solar constant varies approximately with the 11-year solar cycle observed in other solar phenomena, such as the occurrence of sunspots, dark spots that are sometimes visible on the solar surface. When a sunspot occurs on the sun, since the spot is dark, the radiation (light) emitted by the sun drops instantaneously. Oddly, periods of high solar activity, when a lot of sunspot numbers increase, correspond to periods when the average solar constant is high. This indicates that

  12. Characterization of perovskite solar cells: Towards a reliable measurement protocol

    Directory of Open Access Journals (Sweden)

    Eugen Zimmermann

    2016-09-01

    Full Text Available Lead halide perovskite solar cells have shown a tremendous rise in power conversion efficiency with reported record efficiencies of over 20% making this material very promising as a low cost alternative to conventional inorganic solar cells. However, due to a differently severe “hysteretic” behaviour during current density-voltage measurements, which strongly depends on scan rate, device and measurement history, preparation method, device architecture, etc., commonly used solar cell measurements do not give reliable or even reproducible results. For the aspect of commercialization and the possibility to compare results of different devices among different laboratories, it is necessary to establish a measurement protocol which gives reproducible results. Therefore, we compare device characteristics derived from standard current density-voltage measurements with stabilized values obtained from an adaptive tracking of the maximum power point and the open circuit voltage as well as characteristics extracted from time resolved current density-voltage measurements. Our results provide insight into the challenges of a correct determination of device performance and propose a measurement protocol for a reliable characterisation which is easy to implement and has been tested on varying perovskite solar cells fabricated in different laboratories.

  13. The BAT AGN Spectroscopic Survey (BASS) DR1-Spectral Measurements, Derived Quantities, and AGN Demographics

    Science.gov (United States)

    Koss, Michael; BASS Team

    2018-01-01

    We present the first catalog and data release of the Swift-BAT AGN Spectroscopic Survey (BASS). We analyze optical spectra of the majority of AGN (77%, 641/836) detected based on their 14-195 keV emission in the 70-month Swift BAT all-sky catalog. This includes redshift determination, absorption and emission line measurements, and black hole mass and accretion rate estimates for the majority of obscured and un-obscured AGN (74%, 473/641) with 340 measured for the first time. With ~90% of sources at z10^21.9 cm^-2. Seyfert 1.9 show a range of column densities. Compared to narrow line AGN in the SDSS, the X-ray selected AGN have a larger fraction of dusty host galaxies suggesting these types of AGN are missed in optical surveys. Using the most sensitive [OIII]/Hbeta and [NII]/Halpha emission line diagnostic, about half of the sources are classified as Seyferts, ~15% reside in dusty galaxies that lack an Hbeta detection, but for which the line upper limits imply either a Seyfert or LINER, ~15% are in galaxies with weak or no emission lines despite high quality spectra, and a few percent each are LINERS, composite galaxies, HII regions, or in known beamed AGN.

  14. Measurement of solar spectra relating to photosynthesis and solar cells: an inquiry lab for secondary science.

    Science.gov (United States)

    Ruggirello, Rachel M; Balcerzak, Phyllis; May, Victoria L; Blankenship, Robert E

    2012-07-01

    The process of photosynthesis is central to science curriculum at all levels. This article describes an inquiry-based laboratory investigation developed to explore the impact of light quality on photosynthesis and to connect this process to current research on harvesting solar energy, including bioenergy, artificial photosynthesis, and solar cells. This laboratory was used with high-school science teachers who then took this experience back to their classrooms. During this exercise, teachers used an economical spectroradiometer to measure the solar spectrum and relate this to photosynthetic light absorption by determining the quality of light beneath trees. Following this investigation, teachers learned about the plant-inspired dye-sensitized solar cells and constructed one. To connect their light quality investigation to the efficiency of photosynthesis and solar cells, teachers then collected data at locations with varying quality and intensity of light. In sum, this investigation provides a crucial connection between photosynthesis and cutting edge research on solar energy technologies. Our learning experience provides a new instructional model for understanding a little investigated aspect of photosynthesis and connects to authentic scientific research. Copyright © 2012 Wiley Periodicals, Inc.

  15. Study of oxide/metal/oxide thin films for transparent electronics and solar cells applications by spectroscopic ellipsometry

    Directory of Open Access Journals (Sweden)

    Mihaela Girtan

    2017-05-01

    Full Text Available A comprehensive study of a class of Oxide/Metal/Oxide (Oxide = ITO, AZO, TiO2 and Bi2O3, Metal = Au thin films was done by correlating the spectrophotometric studies with the ellispometric models. Films were deposited by successive sputtering from metallic targets In:Sn, Zn:Al, Ti and Bi in reactive atmosphere (for the oxide films and respective inert atmosphere (for the metallic Au interlayer films on glass substrates. The measurements of optical constants n—the refractive index and k—the extinction coefficient, at different incident photon energies for single oxide films and also for the three layers films oxide/metal/oxide samples were made using the spectroscopic ellipsometry (SE technique. The ellipsometry modelling process was coupled with the recorded transmission spectra data of a double beam spectrophotometer and the best fitting parameters were obtained not only by fitting the n and k experimental data with the dispersion fitting curves as usual is practiced in the most reported data in literature, but also by comparing the calculated the transmission coefficient from ellipsometry with the experimental values obtained from direct spectrophotometry measurements. In this way the best dispersion model was deduced for each sample. Very good correlations were obtained for the other different thin films characteristics such as the films thickness, optical band gap and electrical resistivity obtained by other measurements and calculation techniques. The ellipsometric modelling, can hence give the possibility in the future to predict, by ellipsometric simulations, the proper device architecture in function of the preferred optical and electrical properties.

  16. Measurements of thermal parameters of solar modules

    International Nuclear Information System (INIS)

    Górecki, K; Krac, E

    2016-01-01

    In the paper the methods of measuring thermal parameters of photovoltaic panels - transient thermal impedance and the absorption factor of light-radiation are presented. The manner of realising these methods is described and the results of measurements of the considered thermal parameters of selected photovoltaic panels are presented. The influence of such selected factors as a type of the investigated panel and its mounting manner on transient thermal impedance of the considered panels is also discussed. (paper)

  17. Laser Cooling and Trapping of Neutral Strontium for Spectroscopic Measurements of Casimir-Polder Potentials

    Science.gov (United States)

    Cook, Eryn C.

    Casimir and Casimir-Polder effects are forces between electrically neutral bodies and particles in vacuum, arising entirely from quantum fluctuations. The modification to the vacuum electromagnetic-field modes imposed by the presence of any particle or surface can result in these mechanical forces, which are often the dominant interaction at small separations. These effects play an increasingly critical role in the operation of micro- and nano-mechanical systems as well as miniaturized atomic traps for precision sensors and quantum-information devices. Despite their fundamental importance, calculations present theoretical and numeric challenges, and precise atom-surface potential measurements are lacking in many geometric and distance regimes. The spectroscopic measurement of Casimir-Polder-induced energy level shifts in optical-lattice trapped atoms offers a new experimental method to probe atom-surface interactions. Strontium, the current front-runner among optical frequency metrology systems, has demonstrated characteristics ideal for such precision measurements. An alkaline earth atom possessing ultra-narrow intercombination transitions, strontium can be loaded into an optical lattice at the "magic" wavelength where the probe transition is unperturbed by the trap light. Translation of the lattice will permit controlled transport of tightly-confined atomic samples to well-calibrated atom-surface separations, while optical transition shifts serve as a direct probe of the Casimir-Polder potential. We have constructed a strontium magneto-optical trap (MOT) for future Casimir-Polder experiments. This thesis will describe the strontium apparatus, initial trap performance, and some details of the proposed measurement procedure.

  18. Modeling the effect of reflection from metallic walls on spectroscopic measurements

    International Nuclear Information System (INIS)

    Zastrow, K.-D.; Keatings, S. R.; O'Mullane, M. G.; Marot, L.; Temmerman, G. de

    2008-01-01

    A modification of JET is presently being prepared to bring operational experience with ITER-like first wall (Be) and divertor (W) materials, geometry and plasma parameters. Reflectivity measurements of JET sample tiles have been performed and the data are used within a simplified model of the JET and ITER vessels to predict additional contributions to quantitative spectroscopic measurements. The most general method to characterize reflectivity is the bidirectional reflection distribution function (BRDF). For extended sources however, such as bremsstrahlung and edge emission of fuel and intrinsic impurities, the results obtained in the modeling are almost as accurate if the total reflectivity with ideal Lambertian angular dependence is used. This is in contrast to the experience in other communities, such as optical design, lighting design, or rendering who deal mostly with pointlike light sources. This result is so far based on a very limited set of measurements and will be reassessed when more detailed BRDF measurements of JET tiles have been made. If it is true it offers the possibility of in situ monitoring of the reflectivity of selected parts of the wall during exposure to plasma operation, while remeasurement of the BRDF is performed during interventions. For a closed vessel structure such as ITER, it is important to consider multiple reflections. This makes it more important to represent the whole of the vessel reasonably accurately in the model, which on the other hand is easier to achieve than for the more complex internal structure of JET. In both cases the dominant contribution is from the first reflection, and a detailed model of the areas intersected by lines of sight of diagnostic interest is required.

  19. Multi-slice echo-planar spectroscopic MR imaging provides both global and local metabolite measures in multiple sclerosis

    DEFF Research Database (Denmark)

    Mathiesen, Henrik Kahr; Tscherning, Thomas; Sorensen, Per Soelberg

    2005-01-01

    MR spectroscopy (MRS) provides information about neuronal loss or dysfunction by measuring decreases in N-acetyl aspartate (NAA), a metabolite widely believed to be a marker of neuronal viability. In multiple sclerosis (MS), whole-brain NAA (WBNAA) has been suggested as a marker of disease...... progression and treatment efficacy in treatment trials, and the ability to measure NAA loss in specific brain regions early in the evolution of this disease may have prognostic value. Most spectroscopic studies to date have been limited to single voxels or nonlocalized measurements of WBNAA only......, measurements of metabolites in specific brain areas chosen after image acquisition (e.g., normal-appearing white matter (NAWM), gray matter (GM), and lesions) can be obtained. The identification and exclusion of regions that are inadequate for spectroscopic evaluation in global assessments can significantly...

  20. Absorber Alignment Measurement Tool for Solar Parabolic Trough Collectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Stynes, J. K.; Ihas, B.

    2012-04-01

    As we pursue efforts to lower the capital and installation costs of parabolic trough solar collectors, it is essential to maintain high optical performance. While there are many optical tools available to measure the reflector slope errors of parabolic trough solar collectors, there are few tools to measure the absorber alignment. A new method is presented here to measure the absorber alignment in two dimensions to within 0.5 cm. The absorber alignment is measured using a digital camera and four photogrammetric targets. Physical contact with the receiver absorber or glass is not necessary. The alignment of the absorber is measured along its full length so that sagging of the absorber can be quantified with this technique. The resulting absorber alignment measurement provides critical information required to accurately determine the intercept factor of a collector.

  1. FAST DIFFERENTIAL EMISSION MEASURE INVERSION OF SOLAR CORONAL DATA

    Energy Technology Data Exchange (ETDEWEB)

    Plowman, Joseph; Kankelborg, Charles; Martens, Petrus [Montana State University, Bozeman, MT 59717 (United States)

    2013-07-01

    We present a fast method for reconstructing differential emission measures (DEMs) using solar coronal data. The method consists of a fast, simple regularized inversion in conjunction with an iteration scheme for removal of residual negative emission measure. On average, it computes over 1000 DEMs s{sup -1} for a sample active region observed by the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory, and achieves reduced chi-squared of order unity with no negative emission in all but a few test cases. The high performance of this method is especially relevant in the context of AIA, which images of order one million solar pixels per second. This paper describes the method, analyzes its fidelity, compares its performance and results with other DEM methods, and applies it to an active region and loop observed by AIA and by the Extreme-ultraviolet Imaging Spectrometer on Hinode.

  2. Spectroscopic Measurements of the Far-Ultraviolet Dust Attenuation Curve at z ˜ 3

    Science.gov (United States)

    Reddy, Naveen A.; Steidel, Charles C.; Pettini, Max; Bogosavljević, Milan

    2016-09-01

    We present the first spectroscopic measurements of the shape of the far-ultraviolet (far-UV; λ =950{--}1500 Å) dust attenuation curve at high redshift (z˜ 3). Our analysis employs rest-frame UV spectra of 933 galaxies at z˜ 3, 121 of which have very deep spectroscopic observations (≳ 7 hr) at λ =850{--}1300 \\mathring{{A}} , with the Low Resolution Imaging Spectrograph on the Keck Telescope. By using an iterative approach in which we calculate the ratios of composite spectra in different bins of continuum color excess, E(B-V), we derive a dust curve that implies a lower attenuation in the far-UV for a given E(B-V) than those obtained with standard attenuation curves. We demonstrate that the UV composite spectra of z˜ 3 galaxies can be modeled well by assuming our new attenuation curve, a high covering fraction of H I, and absorption from the Lyman-Werner bands of {{{H}}}2 with a small (≲ 20 % ) covering fraction. The low covering fraction of {{{H}}}2 relative to that of the {{H}} {{I}} and dust suggests that most of the dust in the ISM of typical galaxies at z˜ 3 is unrelated to the catalysis of {{{H}}}2, and is associated with other phases of the ISM (I.e., the ionized and neutral gas). The far-UV dust curve implies a factor of ≈ 2 lower dust attenuation of Lyman continuum (ionizing) photons relative to those inferred from the most commonly assumed attenuation curves for L* galaxies at z˜ 3. Our results may be utilized to assess the degree to which ionizing photons are attenuated in H II regions or, more generally, in the ionized or low column density (N({{H}} {{I}})≲ {10}17.2 cm-2) neutral ISM of high-redshift galaxies. Based on data obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W.M. Keck Foundation.

  3. Spectroscopic measurements of lithium influx from an actively water-cooled liquid lithium limiter on FTU

    Energy Technology Data Exchange (ETDEWEB)

    Apruzzese, G.M., E-mail: gerarda.apruzzese@enea.it; Apicella, M.L.; Maddaluno, G.; Mazzitelli, G.; Viola, B.

    2017-04-15

    Since 2006, experiments using a liquid lithium limiter (LLL) were successfully performed on FTU, pointing out the problem of the quantity of lithium in the plasma, especially in conditions of strong evaporation due to the high temperature of limiter surface. In order to avoid the strong evaporation it is necessary to control the temperature by removing the heat from the limiter during the plasma exposure. To explore this issue a new actively cooled lithium limiter (CLL) has been installed and tested in FTU. Suitable monitors to detect the presence of lithium in the plasma are the spectroscopic diagnostics in the visible range that permit to measure the flux of lithium, coming from the limiter surface, through the brightness of the LiI spectral lines. For this aim an Optical Multichannel Analyser (OMA) spectrometer and a single wavelength impurities monitor have been used. The analysis of the Li influx signals has permitted to monitor the effects of interaction between the plasma and the limiter connected to the thermal load. Particular attention has been paid on the possible occurrence of sudden rise of the signals, which is an index of a strong interaction that could lead to a disruption. On the other hand, the appearance of significant signals gives useful indication if the interaction with the plasma has taken place.

  4. Voyager microwave scintillation measurements of solar wind plasma parameters

    International Nuclear Information System (INIS)

    Martin, J.M.

    1985-01-01

    During the solar conjunctions of Voyager 1 and 2 spacecraft in August 1979, September 1980, and November 1982, temporal variations of intensity and frequency of the dual-wavelength (3.6 and 13 cm) radio transmissions from the spacecraft were observed and subsequently analyzed to infer characteristics of the solar wind plasma flow. Measurements of the temporal wave structure function were used to estimate the spectral index of the power law spatial spectrum of irregularities. Theoretical-intensity scintillation spectra were compared with measured intensity spectra to obtain least-squares estimates of (1) mean velocity, (2) random velocity, (3) axial ratio, and (4) electron density standard deviation. Uncertainties in parameter estimates were calculated by standard propagation of errors techniques. Mean velocity and electron density standard deviations in 1979-1980 show little dependence on solar latitude. Density standard deviation estimates were 3-10% of the background mean density and mean velocity estimates ranged from approx.200 km/s inside 17 solar radii to approx.300 km/s at 25 solar radii. 1982 density standard deviation estimates increased rapidly with latitude near 45 0 N, then sharply decreased north of that latitude, indicating the existence of a polar region of reduced fluctuations surrounded by a thin cone of strong density irregularities

  5. Measurements and modeling of total solar irradiance in X-class solar flares

    International Nuclear Information System (INIS)

    Moore, Christopher Samuel; Chamberlin, Phillip Clyde; Hock, Rachel

    2014-01-01

    The Total Irradiance Monitor (TIM) from NASA's SOlar Radiation and Climate Experiment can detect changes in the total solar irradiance (TSI) to a precision of 2 ppm, allowing observations of variations due to the largest X-class solar flares for the first time. Presented here is a robust algorithm for determining the radiative output in the TIM TSI measurements, in both the impulsive and gradual phases, for the four solar flares presented in Woods et al., as well as an additional flare measured on 2006 December 6. The radiative outputs for both phases of these five flares are then compared to the vacuum ultraviolet (VUV) irradiance output from the Flare Irradiance Spectral Model (FISM) in order to derive an empirical relationship between the FISM VUV model and the TIM TSI data output to estimate the TSI radiative output for eight other X-class flares. This model provides the basis for the bolometric energy estimates for the solar flares analyzed in the Emslie et al. study.

  6. Spectroscopic measurement of the MHD dynamo in the MST reversed field pinch

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, James Tharp [Univ. of Wisconsin, Madison, WI (United States)

    1998-09-01

    The author has directly observed the coupling of ion velocity fluctuations and magnetic field fluctuations to produce an MHD dynamo electric field in the interior of the MST reversed field pinch. Chord averaged ion velocity fluctuations were measured with a fast spectroscopic diagnostic which collects line radiation from intrinsic carbon impurities simultaneously along two lines of sight. The chords employed for the measurements resolved long wavelength velocity fluctuations of several km/s at 8-20 kHz as tiny, fast Doppler shifts in the emitted line profile. During discrete dynamo events the velocity fluctuations, like the magnetic fluctuations, increase dramatically. The toroidal and poloidal chords with impact parameters of 0.3 a and 0.6 a respectively, resolved fluctuation wavenumbers with resonance surfaces near or along the lines of sight indicating a radial velocity fluctuation width for each mode which spans only a fraction of the plasma radius. The phase between the measured toroidal velocity fluctuations and the magnetic fluctuations matches the predictions of resistive MHD while the poloidal velocity fluctuations exhibit a phase consistent with the superposition of MHD effects and the advection of a mean flow gradient past the poloidal line of sight. Radial velocity fluctuations resolved by a chord through the center of the plasma were small compared to the poloidal and toroidal fluctuations and exhibited low coherence with the magnetic fluctuations. The ensembled nonlinear product of the ion velocity fluctuations and fluctuations in the magnetic field indicates a substantial dynamo electric field which peaks during the periods of spontaneous flux generation.

  7. Spectroscopic measurement of the MHD dynamo in the MST reversed field pinch

    International Nuclear Information System (INIS)

    Chapman, J.T.

    1998-09-01

    The author has directly observed the coupling of ion velocity fluctuations and magnetic field fluctuations to produce an MHD dynamo electric field in the interior of the MST reversed field pinch. Chord averaged ion velocity fluctuations were measured with a fast spectroscopic diagnostic which collects line radiation from intrinsic carbon impurities simultaneously along two lines of sight. The chords employed for the measurements resolved long wavelength velocity fluctuations of several km/s at 8--20 kHz as tiny, fast Doppler shifts in the emitted line profile. During discrete dynamo events the velocity fluctuations, like the magnetic fluctuations, increase dramatically. The toroidal and poloidal chords with impact parameters of 0.3 a and 0.6 a respectively, resolved fluctuation wavenumbers with resonance surfaces near or along the lines of sight indicating a radial velocity fluctuation width for each mode which spans only a fraction of the plasma radius. The phase between the measured toroidal velocity fluctuations and the magnetic fluctuations matches the predictions of resistive MHD while the poloidal velocity fluctuations exhibit a phase consistent with the superposition of MHD effects and the advection of a mean flow gradient past the poloidal line of sight. Radial velocity fluctuations resolved by a chord through the center of the plasma were small compared to the poloidal and toroidal fluctuations and exhibited low coherence with the magnetic fluctuations. The ensembled nonlinear product of the ion velocity fluctuations and fluctuations in the magnetic field indicates a substantial dynamo electric field which peaks during the periods of spontaneous flux generation

  8. new model for solar radiation estimation from measured air

    African Journals Online (AJOL)

    HOD

    RMSE) and correlation ... countries due to the unavailability of measured data in place [3-5]. ... models were used to predict solar radiation in Nigeria by. [12-15]. However ..... "Comparison of Gene Expression Programming with neuro-fuzzy and ...

  9. Listing of solar radiation measuring equipment and glossary

    Science.gov (United States)

    Carter, E. A.; Greenbaum, S. A.; Patel, A. M.

    1976-01-01

    An attempt is made to list and provide all available information about solar radiation measuring equipment which are being manufactured and are available on the market. The list is in tabular form and includes sensor type, response time, cost data and comments for each model. A cost code is included which shows ranges only.

  10. Evaluation of Sources of Uncertainties in Solar Resource Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Habte, Aron M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sengupta, Manajit [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-25

    This poster presents a high-level overview of sources of uncertainties in solar resource measurement, demonstrating the impact of various sources of uncertainties -- such as cosine response, thermal offset, spectral response, and others -- on the accuracy of data from several radiometers. The study provides insight on how to reduce the impact of some of the sources of uncertainties.

  11. Accurate measurement of directional emittance of solar energy materials

    NARCIS (Netherlands)

    Nijnatten, van P.A.; Hugo-Le Gof, A.; Granqvist, C.-G.; Lampert, C.M.

    1992-01-01

    Directional emittance plays an important role in the calculation of radiative heat exchange. It partly determines the thermal insulation of single and multiple glazing and the efficiency of solar collectors. An emissiometer has been designed and built, capable for measurements of the directional

  12. Colors of Outer Solar System Objects Measured with VATT

    Science.gov (United States)

    Romanishin, William; Tegler, S. C.; Consolmagno, G. J.

    2010-10-01

    Over the past 7 years, we have measured optical B-V and V-R colors for about 40 minor outer solar system objects using the 1.8-m Vatican Advanced Technology Telescope (VATT) located on Mt. Graham in southeast Arizona. We will present these colors and use them to update the discussion of colors of minor bodies in the outer solar system. We gratefully acknowledge funding from the NASA Planetary Astronomy Program to Northern Arizona University and the U. of Oklahoma which helped support this work.

  13. Measures for diffusion of solar PV in selected African countries

    DEFF Research Database (Denmark)

    Nygaard, Ivan; Hansen, Ulrich Elmer; Mackenzie, Gordon A.

    2017-01-01

    that governments’ strategies to promoting solar PV are moving from isolated projects towards frameworks for market development and that there are high expectations to upgrading in the PV value chain through local assembly of panels and local production of other system elements. Commonly identified measures include......This paper investigates how African governments are considering supporting and promoting the diffusion of solar PV. This issue is explored by examining so-called ‘technology action plans (TAPs)’, which were main outputs of the Technology Needs Assessment project implemented in 10 African countries...... from 2010 to 2013. The paper provides a review of three distinct but characteristic trajectories for PV market development in Kenya (private-led market for solar home systems), Morocco (utility-led fee-for service model) and Rwanda (donorled market for institutional systems). The paper finds...

  14. Measures for diffusion of solar PV in selected African countries

    Science.gov (United States)

    Nygaard, Ivan; Hansen, Ulrich Elmer; Mackenzie, Gordon; Pedersen, Mathilde Brix

    2017-08-01

    This paper investigates how African governments are considering supporting and promoting the diffusion of solar PV. This issue is explored by examining so-called 'technology action plans (TAPs)', which were main outputs of the Technology Needs Assessment project implemented in 10 African countries from 2010 to 2013. The paper provides a review of three distinct but characteristic trajectories for PV market development in Kenya (private-led market for solar home systems), Morocco (utility-led fee-for service model) and Rwanda (donor-led market for institutional systems). The paper finds that governments' strategies to promoting solar PV are moving from isolated projects towards frameworks for market development and that there are high expectations to upgrading in the PV value chain through local assembly of panels and local production of other system elements. Commonly identified measures include support to: local production; financing schemes; tax exemptions; establishment and reinforcement of standards; technical training; and research and development.

  15. Photometric intensity and polarization measurements of the solar corona.

    Science.gov (United States)

    Mcdougal, D. S.

    1971-01-01

    Use of a satellite photometric observatory (SPO) to measure the solar corona from Miahuatlan, Mexico during the Mar. 7, 1970, total eclipse of the sun. The SPO is equipped with a 24-in. Cassegrainian telescope, a four-channel photoelectric photometer, a Wollaston prism, and a rotating half-wave plate. Simultaneous measurements were made of the two orthogonal components of coronal light in the B and R bands of the UBVRI system. A 1-minute arc aperture was scanned from the lunar disk center out to five solar radii in a series of spirals of gradually increasing radius. For the first time, simultaneous multicolor intensity, degree, and angle of polarization profiles are computed from photoelectric measurements. Comparison of the variations of the measurements for each spiral scan yield a detailed picture of the intensity and polarization features in the K corona.

  16. Solar energy prediction and verification using operational model forecasts and ground-based solar measurements

    International Nuclear Information System (INIS)

    Kosmopoulos, P.G.; Kazadzis, S.; Lagouvardos, K.; Kotroni, V.; Bais, A.

    2015-01-01

    The present study focuses on the predictions and verification of these predictions of solar energy using ground-based solar measurements from the Hellenic Network for Solar Energy and the National Observatory of Athens network, as well as solar radiation operational forecasts provided by the MM5 mesoscale model. The evaluation was carried out independently for the different networks, for two forecast horizons (1 and 2 days ahead), for the seasons of the year, for varying solar elevation, for the indicative energy potential of the area, and for four classes of cloud cover based on the calculated clearness index (k_t): CS (clear sky), SC (scattered clouds), BC (broken clouds) and OC (overcast). The seasonal dependence presented relative rRMSE (Root Mean Square Error) values ranging from 15% (summer) to 60% (winter), while the solar elevation dependence revealed a high effectiveness and reliability near local noon (rRMSE ∼30%). An increment of the errors with cloudiness was also observed. For CS with mean GHI (global horizontal irradiance) ∼ 650 W/m"2 the errors are 8%, for SC 20% and for BC and OC the errors were greater (>40%) but correspond to much lower radiation levels (<120 W/m"2) of consequently lower energy potential impact. The total energy potential for each ground station ranges from 1.5 to 1.9 MWh/m"2, while the mean monthly forecast error was found to be consistently below 10%. - Highlights: • Long term measurements at different atmospheric cases are needed for energy forecasting model evaluations. • The total energy potential at the Greek sites presented ranges from 1.5 to 1.9 MWh/m"2. • Mean monthly energy forecast errors are within 10% for all cases analyzed. • Cloud presence results of an additional forecast error that varies with the cloud cover.

  17. Topside measurements at Jicamarca during solar minimum

    Directory of Open Access Journals (Sweden)

    D. L. Hysell

    2009-01-01

    Full Text Available Long-pulse topside radar data acquired at Jicamarca and processed using full-profile analysis are compared to data processed using more conventional, range-gated approaches and with analytic and computational models. The salient features of the topside observations include a dramatic increase in the Te/Ti temperature ratio above the F peak at dawn and a local minimum in the topside plasma temperature in the afternoon. The hydrogen ion fraction was found to exhibit hyperbolic tangent-shaped profiles that become shallow (gradually changing above the O+-H+ transition height during the day. The profile shapes are generally consistent with diffusive equilibrium, although shallowing to the point of changes in inflection can only be accounted for by taking the effects of E×B drifts and meridional winds into account. The SAMI2 model demonstrates this as well as the substantial effect that drifts and winds can have on topside temperatures. Significant quiet-time variability in the topside composition and temperatures may be due to variability in the mechanical forcing. Correlations between topside measurements and magnetometer data at Jicamarca support this hypothesis.

  18. Topside measurements at Jicamarca during solar minimum

    Directory of Open Access Journals (Sweden)

    D. L. Hysell

    2009-01-01

    Full Text Available Long-pulse topside radar data acquired at Jicamarca and processed using full-profile analysis are compared to data processed using more conventional, range-gated approaches and with analytic and computational models. The salient features of the topside observations include a dramatic increase in the Te/Ti temperature ratio above the F peak at dawn and a local minimum in the topside plasma temperature in the afternoon. The hydrogen ion fraction was found to exhibit hyperbolic tangent-shaped profiles that become shallow (gradually changing above the O+-H+ transition height during the day. The profile shapes are generally consistent with diffusive equilibrium, although shallowing to the point of changes in inflection can only be accounted for by taking the effects of E×B drifts and meridional winds into account. The SAMI2 model demonstrates this as well as the substantial effect that drifts and winds can have on topside temperatures. Significant quiet-time variability in the topside composition and temperatures may be due to variability in the mechanical forcing. Correlations between topside measurements and magnetometer data at Jicamarca support this hypothesis.

  19. Distributed solar radiation fast dynamic measurement for PV cells

    Science.gov (United States)

    Wan, Xuefen; Yang, Yi; Cui, Jian; Du, Xingjing; Zheng, Tao; Sardar, Muhammad Sohail

    2017-10-01

    To study the operating characteristics about PV cells, attention must be given to the dynamic behavior of the solar radiation. The dynamic behaviors of annual, monthly, daily and hourly averages of solar radiation have been studied in detail. But faster dynamic behaviors of solar radiation need more researches. The solar radiation random fluctuations in minute-long or second-long range, which lead to alternating radiation and cool down/warm up PV cell frequently, decrease conversion efficiency. Fast dynamic processes of solar radiation are mainly relevant to stochastic moving of clouds. Even in clear sky condition, the solar irradiations show a certain degree of fast variation. To evaluate operating characteristics of PV cells under fast dynamic irradiation, a solar radiation measuring array (SRMA) based on large active area photodiode, LoRa spread spectrum communication and nanoWatt MCU is proposed. This cross photodiodes structure tracks fast stochastic moving of clouds. To compensate response time of pyranometer and reduce system cost, the terminal nodes with low-cost fast-responded large active area photodiode are placed besides positions of tested PV cells. A central node, consists with pyranometer, large active area photodiode, wind detector and host computer, is placed in the center of the central topologies coordinate to scale temporal envelope of solar irradiation and get calibration information between pyranometer and large active area photodiodes. In our SRMA system, the terminal nodes are designed based on Microchip's nanoWatt XLP PIC16F1947. FDS-100 is adopted for large active area photodiode in terminal nodes and host computer. The output current and voltage of each PV cell are monitored by I/V measurement. AS62-T27/SX1278 LoRa communication modules are used for communicating between terminal nodes and host computer. Because the LoRa LPWAN (Low Power Wide Area Network) specification provides seamless interoperability among Smart Things without the

  20. Inter-laboratory comparisons of hexenuronic acid measurements in kraft eucalyptus pulps using a UV-Vis spectroscopic method

    Science.gov (United States)

    J.Y. Zhu; H.F Zhou; Chai X.S.; Donna Johannes; Richard Pope; Cristina Valls; M. Blanca Roncero

    2014-01-01

    An inter-laboratory comparison of a UV-Vis spectroscopic method (TAPPI T 282 om-13 “Hexeneuronic acid content of chemical pulp”) for hexeneuronic acid measurements was conducted using three eucalyptus kraft pulps. The pulp samples were produced in a laboratory at kappa numbers of approximately 14, 20, and 35. The hexeneuronic acid contents of the three pulps were...

  1. Precise pointing knowledge for SCIAMACHY solar occultation measurements

    Directory of Open Access Journals (Sweden)

    K. Bramstedt

    2012-11-01

    Full Text Available We present a method to precisely determine the viewing direction for solar occultation instruments from scans over the solar disk. Basic idea is the fit of the maximum intensity during the scan, which corresponds to the center of the solar disk in the scanning direction. We apply this method to the solar occultation measurements of the satellite instrument SCIAMACHY, which scans the Sun in elevation direction. The achieved mean precision is 0.46 mdeg, which corresponds to an tangent height error of about 26 m for individual occultation sequences. The deviation of the derived elevation angle from the geolocation information given along with the product has a seasonal cycle with an amplitude of 2.26 mdeg, which is in tangent height an amplitude of about 127 m. The mean elevation angle offset is −4.41 mdeg (249 m. SCIAMACHY's sun follower device controls the azimuth viewing direction during the occultation measurements. The derived mean azimuth direction has an standard error of 0.65 mdeg, which is about 36 m in horizontal direction at the tangent point. We observe also a seasonal cycle of the azimuth mispointing with an amplitude of 2.3 mdeg, which is slightly increasing with time. The almost constant mean offset is 88 mdeg, which is about 5.0 km horizontal offset at the tangent point.

  2. Multi-slice echo-planar spectroscopic MR imaging provides both global and local metabolite measures in multiple sclerosis

    DEFF Research Database (Denmark)

    Mathiesen, Henrik Kahr; Tscherning, Thomas; Sorensen, Per Soelberg

    2005-01-01

    MR spectroscopy (MRS) provides information about neuronal loss or dysfunction by measuring decreases in N-acetyl aspartate (NAA), a metabolite widely believed to be a marker of neuronal viability. In multiple sclerosis (MS), whole-brain NAA (WBNAA) has been suggested as a marker of disease...... progression and treatment efficacy in treatment trials, and the ability to measure NAA loss in specific brain regions early in the evolution of this disease may have prognostic value. Most spectroscopic studies to date have been limited to single voxels or nonlocalized measurements of WBNAA only...

  3. SOLAR OCCULTATION BY TITAN MEASURED BY CASSINI/UVIS

    Energy Technology Data Exchange (ETDEWEB)

    Capalbo, Fernando J.; Benilan, Yves [Laboratoire Interuniversitaire des Systemes Atmospheriques (LISA), UMR 7583 du CNRS, Universites Paris Est Creteil (UPEC) and Paris Diderot - UPD, 61 avenue du General de Gaulle, 94010 Creteil Cedex (France); Yelle, Roger V.; Koskinen, Tommi T.; Sandel, Bill R. [Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721 (United States); Holsclaw, Gregory M.; McClintock, William E., E-mail: fernando.capalbo@lisa.u-pec.fr [Laboratory for Atmospheric and Space Physics, University of Colorado, 3665 Discovery Drive, Boulder, CO 80303 (United States)

    2013-04-01

    We present the first published analysis of a solar occultation by Titan's atmosphere measured by the Ultraviolet Imaging Spectrograph on board Cassini. The data were measured during flyby T53 in 2009 April and correspond to latitudes between 21 Degree-Sign and 28 Degree-Sign south. The analysis utilizes the absorption of two solar emission lines (584 A and 630 A) in the ionization continuum of the N{sub 2} absorption cross section and solar emission lines around 1085 A where absorption is due to CH{sub 4}. The measured transmission at these wavelengths provides a direct estimate of the N{sub 2} and CH{sub 4} column densities along the line of sight from the spacecraft to the Sun, which we inverted to obtain the number densities. The high signal-to-noise ratio of the data allowed us to retrieve density profiles in the altitude range 1120-1400 km for nitrogen and 850-1300 km for methane. We find an N{sub 2} scale height of {approx}76 km and a temperature of {approx}153 K. Our results are in general agreement with those from previous work, although there are some differences. Particularly, our profiles agree, considering uncertainties, with the density profiles derived from the Voyager 1 Ultraviolet Spectrograph data, and with in situ measurements by the Ion Neutral Mass Spectrometer with revised calibration.

  4. The application of coronal scattering measurements to solar radio bursts

    International Nuclear Information System (INIS)

    Bradford, H.M.

    1980-01-01

    The interpretation of ground based observations of solar 'plasma frequency' radio bursts has been hampered in the past by an insufficient knowledge of coronal scattering by density inhomogeneities close to the Sun. Calculations based on measuurements of the angular broadening of natural radio sources, and Woo's 1975 measurement of the angular broadening of the telemetry carrier by Helios I near occultation (Woo, 1978), indicate that plasma frequency solar bursts should undergo considerable scattering, at least near the maximum of the sunspot cycle. The calculated displacements of the apparent positions of the bursts are about equal to the observed displacements which have been attributed to the bursts occurring in dense streamers. In order to obtain more scattering data close to the Sun, interferometer measurements of the angular broadening of spacecraft signals are planned, and the important contribution which could be made with large dishes is discussed. (Auth.)

  5. Erythemal solar UV measurement network in New Zealand

    International Nuclear Information System (INIS)

    Smith, G.J.

    1993-01-01

    Measured daily total erythemal doses for 1989, 1990 and 1991 were presented and the cloudless-sky daily dose at the autumn equinox was approximately 30-50% higher than at the spring equinox as a result of the seasonal variation in ozone levels. In addition a substantially lower spring equinox erythemal dose was observed in 1991, probably as a result of increased aerosols arising from the Pinatubo eruption. An asymmetry in the diurnal pattern of irradiances about solar noon has been observed on cloudless days. Higher UV irradiances have been usually observed in the afternoons than in the mornings. Measurement of erythemal radiation is needed for skin cancer epidemiology projects. Given the uncertainties relating to the exposure of individuals to solar erythemal radiation, personal dosimeters may be very useful in providing more reliable personal UV exposure data. (author). 4 refs

  6. A Preliminary Analysis of Solar Irradiance Measurements at TNB Solar Research Centre for Optimal Orientation of Fixed Solar Panels installed in Selangor Malaysia

    International Nuclear Information System (INIS)

    Hashim, A M; Ahmad, B; Shafie, R M; Rusli, R; Aziz, M A; Hassan, J; Wanik, M Z C; Ali, M A M

    2013-01-01

    The well established rule for orienting fixed solar devices is to face south for places in the northern hemisphere and northwards for the southern hemisphere. However for regions near the equator such as in Selangor Malaysia, the position of the sun at solar noon is always near zenith both to the north and south depending on location and month of year. This paper reports an analysis of global solar radiation data taken at TNB Solar Research Centre, Malaysia. The solar radiation is measured using both shaded and exposed pyranometers together with a pyrheliometer which is mounted on a sun-tracker. The analysis on the solar measurements show that a near regular solar irradiation pattern had occurred often enough during the year to recommend an optimum azimuth orientation of installing the fixed solar panels tilted facing towards east. Even though all the solar measurements were done at a single location in TNBR Solar Research Centre at Bangi, for locations near the equator with similar weather pattern, the recommended azimuth direction of installing fixed solar panels and collectors tilted eastward will also be generally valid.

  7. Spectroscopic system for impurity measurements in the TJ-1 Tokamak of JEN

    International Nuclear Information System (INIS)

    Navas, G.; Zurro, B.

    1982-01-01

    we describe a spectroscopic system with spatial resolution capability that has been configured for plasma diagnostic in the TJ-1 Tokamak of JEN. The experimental system, based on a one meter monochromator, has been absolutely calibrated using a tungsten-halogen lamp. The calibration procedures and the absolute spectral sensitivity are presented as well as its dependence with the polarization. A simplified spectroscopic model of the radiation emitted by the intrinsic plasma impurities (C, 0, . . . ) has been developed. A one dimensional model of the temporal evolution of various ionization stages in coronal equilibrium is used to predict the electron temperature and impurity concentration. This model has been applied to experimental data from several Tokamaks. (Author) 23 refs

  8. Infrared spectroscopic measurement of skin hydration and sebum levels and comparison to corneometer and sebumeter

    OpenAIRE

    Ezerskaia, A.; Pereira, S.F.; Urbach, Paul; Varghese, Babu; Popp, Jürgen; Tuchin, Valery V.; Matthews, Dennis L.; Pavone, Francesco S.

    2016-01-01

    Skin health characterized by a system of water and lipids in Stratum Corneum provide protection from harmful external elements and prevent trans-epidermal water loss. Skin hydration (moisture) and sebum (skin surface lipids) are considered to be important factors in skin health; a right balance between these components is an indication of skin health and plays a central role in protecting and preserving skin integrity. In this manuscript we present an infrared spectroscopic method for simulta...

  9. MEASURING THE MASS OF SOLAR SYSTEM PLANETS USING PULSAR TIMING

    International Nuclear Information System (INIS)

    Champion, D. J.; Hobbs, G. B.; Manchester, R. N.; Edwards, R. T.; Burke-Spolaor, S.; Sarkissian, J. M.; Backer, D. C.; Bailes, M.; Bhat, N. D. R.; Van Straten, W.; Coles, W.; Demorest, P. B.; Ferdman, R. D.; Purver, M. B.; Folkner, W. M.; Hotan, A. W.; Kramer, M.; Lommen, A. N.; Nice, D. J.; Stairs, I. H.

    2010-01-01

    High-precision pulsar timing relies on a solar system ephemeris in order to convert times of arrival (TOAs) of pulses measured at an observatory to the solar system barycenter. Any error in the conversion to the barycentric TOAs leads to a systematic variation in the observed timing residuals; specifically, an incorrect planetary mass leads to a predominantly sinusoidal variation having a period and phase associated with the planet's orbital motion about the Sun. By using an array of pulsars (PSRs J0437-4715, J1744-1134, J1857+0943, J1909-3744), the masses of the planetary systems from Mercury to Saturn have been determined. These masses are consistent with the best-known masses determined by spacecraft observations, with the mass of the Jovian system, 9.547921(2) x10 -4 M sun , being significantly more accurate than the mass determined from the Pioneer and Voyager spacecraft, and consistent with but less accurate than the value from the Galileo spacecraft. While spacecraft are likely to produce the most accurate measurements for individual solar system bodies, the pulsar technique is sensitive to planetary system masses and has the potential to provide the most accurate values of these masses for some planets.

  10. Measurement of global solar radiation over Brunei Darussalam

    International Nuclear Information System (INIS)

    Malik, A.Q.; Ak Abd Malik Abd Raub Pg Ghani

    2006-01-01

    Measurements of global solar radiation on a horizontal surface were carried out for a period of 11 months starting from June 2001 to April 2002. The pyrano meter (Kipp and Zonen) was placed at the top of the library building of University of Brunei Darussalam, which affords optimum exposure to the instrument sensor without appreciable obstacle for incoming global radiation. The maximum and minimum monthly-averaged global irradiations of 553 W/m 2 and 433 W/m 2 were recorded for the months of March and October respectively. The variation of global solar radiation can be divided into two distinct groups - the low radiation values being associated with cloud and turbidity while the high values are associated with less turbid and cloudy periods

  11. Automatic solar image motion measurements. [electronic disk flux monitoring

    Science.gov (United States)

    Colgate, S. A.; Moore, E. P.

    1975-01-01

    The solar seeing image motion has been monitored electronically and absolutely with a 25 cm telescope at three sites along the ridge at the southern end of the Magdalena Mountains west of Socorro, New Mexico. The uncorrelated component of the variations of the optical flux from two points at opposite limbs of the solar disk was continually monitored in 3 frequencies centered at 0.3, 3 and 30 Hz. The frequency band of maximum signal centered at 3 Hz showed the average absolute value of image motion to be somewhat less than 2sec. The observer estimates of combined blurring and image motion were well correlated with electronically measured image motion, but the observer estimates gave a factor 2 larger value.

  12. Temperature Measurements in the Solar Transition Region Using N III Line Intensity Ratios

    Science.gov (United States)

    Doron, R.; Doschek, G. A.; Laming, J. M.; Feldman, U.; Bhatia, A. K.

    2003-01-01

    UV emission from B-like N and O ions a rather rare opportunity for recording spectral lines in a narrow wavelength range that can potentially be used to derive temperatures relevant to the solar transition region. In these ions, the line intensity ratios of the type (2s2p(sup 2) - 2p(sup 3)) / (2s(sup 2)2p - 2s2p(sup 2)) are very sensitive to the electron temperature. Additionally, the lines involving the ratios fall within a range of only - 12 A; in N III the lines fall in the 980 - 992 A range and in O IV in the 780 - 791 A range. In this work, we explore the use of these atomic systems, primarily in N III, for temperature diagnostics of the transition region by analyzing UV spectra obtained by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer flown on the Solar and Heliospheric Observatory (SOHO). The N III temperature-sensitive line ratios are measured in more than 60 observations. Most of the measured ratios correspond to temperatures in the range 5.7x10(exp 4) - 6.7x10(exp 4) K. This range is considerably lower than the calculated temperature of maximum abundance of N III, which is approx. 7.6x10(exp 4) K. Detailed analysis of the spectra further indicates that the measured ratios are probably somewhat overestimated due to resonant scattering effects in the 2s(sup 2)2p - 2s2p(sup 2) lines and small blends in the 2s2p(sup 2) - 2p3 lines. Actual lower ratios would only increase the disagreement between the ionization balance calculations and present temperature measurements based on a collisional excitation model. In the case of the O IV spectra, we determined that due to the close proximity in wavelength of the weak line (2s2p(sup 2)-2p3 transitions) to a strong Ne VIII line, sufficiently accurate ratio measurements cannot be obtained. Subject headings: atomic data --- atomic processes --- Sun: transition region --- Sun: U V radiation --- techniques: spectroscopic

  13. Millimeter wave spectroscopic measurements of stratospheric and mesospheric constituents over the Italian Alps: stratospheric ozone

    Directory of Open Access Journals (Sweden)

    V. Romaniello

    2007-06-01

    Full Text Available Measurements of rotational lines emitted by middle atmospheric trace gases have been carried out from the Alpine station of Testa Grigia (45.9°N, 7.7°E, elev. 3500 m by means of a Ground-Based Millimeter-wave Spectrometer (GBMS. Observations of species such as O3, HNO3, CO, N2O, HCN, and HDO took place during 4 winter periods, from February 2004 to March 2007, for a total of 116 days of measurements grouped in about 18 field campaigns. By studying the pressure-broadened shape of emission lines the vertical distribution of the observed constituents is retrieved within an altitude range of ?17-75 km, constrained by the 600 MHz pass band and the 65 kHz spectral resolution of the back-end spectrometer. This work discusses the behavior of stratospheric O3 during the entire period of operation at Testa Grigia. Mid-latitude O3 columnar content as estimated using GBMS measurements can vary by large amounts over a period of very few days, with the largest variations observed in December 2005, February 2006, and March 2006, confirming that the northern winter of 2005-2006 was characterized by a particularly intense planetary wave activity. The largest rapid variation from maximum to minimum O3 column values over Testa Grigia took place in December 2006 and reached a relative value of 72% with respect to the average column content for that period. During most GBMS observation times much of the variability is concentrated in the column below 20 km, with tropospheric weather systems and advection of tropical tropospheric air into the lower stratosphere over Testa Grigia having a large impact on the observed variations in column contents. Nonetheless, a wide variability is also found in middle stratospheric GBMS O3 measurements, as expected for mid-latitude ozone. We find that O3 mixing ratios at ?32 km are very well correlated with the solar illumination experienced by air masses over the previous ?15 days, showing that already at 32 km

  14. Slope Error Measurement Tool for Solar Parabolic Trough Collectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Stynes, J. K.; Ihas, B.

    2012-04-01

    The National Renewable Energy Laboratory (NREL) has developed an optical measurement tool for parabolic solar collectors that measures the combined errors due to absorber misalignment and reflector slope error. The combined absorber alignment and reflector slope errors are measured using a digital camera to photograph the reflected image of the absorber in the collector. Previous work using the image of the reflection of the absorber finds the reflector slope errors from the reflection of the absorber and an independent measurement of the absorber location. The accuracy of the reflector slope error measurement is thus dependent on the accuracy of the absorber location measurement. By measuring the combined reflector-absorber errors, the uncertainty in the absorber location measurement is eliminated. The related performance merit, the intercept factor, depends on the combined effects of the absorber alignment and reflector slope errors. Measuring the combined effect provides a simpler measurement and a more accurate input to the intercept factor estimate. The minimal equipment and setup required for this measurement technique make it ideal for field measurements.

  15. Estimation of diffuse from measured global solar radiation

    International Nuclear Information System (INIS)

    Moriarty, W.W.

    1991-01-01

    A data set of quality controlled radiation observations from stations scattered throughout Australia was formed and further screened to remove residual doubtful observations. It was then divided into groups by solar elevation, and used to find average relationships for each elevation group between relative global radiation (clearness index - the measured global radiation expressed as a proportion of the radiation on a horizontal surface at the top of the atmosphere) and relative diffuse radiation. Clear-cut relationships were found, which were then fitted by polynomial expressions giving the relative diffuse radiation as a function of relative global radiation and solar elevation. When these expressions were used to estimate the diffuse radiation from the global, the results had a slightly smaller spread of errors than those from an earlier technique given by Spencer. It was found that the errors were related to cloud amount, and further relationships were developed giving the errors as functions of global radiation, solar elevation, and the fraction of sky obscured by high cloud and by opaque (low and middle level) cloud. When these relationships were used to adjust the first estimates of diffuse radiation, there was a considerable reduction in the number of large errors

  16. Online educative activities for solar ultraviolet radiation based on measurements of cloud amount and solar exposures.

    Science.gov (United States)

    Parisi, A V; Downs, N; Turner, J; Amar, A

    2016-09-01

    A set of online activities for children and the community that are based on an integrated real-time solar UV and cloud measurement system are described. These activities use the functionality of the internet to provide an educative tool for school children and the public on the influence of cloud and the angle of the sun above the horizon on the global erythemal UV or sunburning UV, the diffuse erythemal UV, the global UVA (320-400nm) and the vitamin D effective UV. Additionally, the units of UV exposure and UV irradiance are investigated, along with the meaning and calculation of the UV index (UVI). This research will help ensure that children and the general public are better informed about sun safety by improving their personal understanding of the daily and the atmospheric factors that influence solar UV radiation and the solar UV exposures of the various wavebands in the natural environment. The activities may correct common misconceptions of children and the public about UV irradiances and exposure, utilising the widespread reach of the internet to increase the public's awareness of the factors influencing UV irradiances and exposures in order to provide clear information for minimizing UV exposure, while maintaining healthy, outdoor lifestyles. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. The SOLAR-C Mission

    Science.gov (United States)

    Suematsu, Y.

    2015-12-01

    The Solar-C is a Japan-led international solar mission planned to be launched in mid2020. It is designed to investigate the magnetic activities of the Sun, focusing on the study in heating and dynamical phenomena of the chromosphere and corona, and also to develop an algorithm for predicting short and long term solar evolution. Since it has been revealed that the different parts of the magnetized solar atmosphere are essentially coupled, the SOLAR-C should tackle the spatial scales and temperature regimes that need to be observed in order to achieve a comprehensive physical understanding of this coupling. The science of Solar-C will greatly advance our understanding of the Sun, of basic physical processes operating throughout the universe. To dramatically improve the situation, SOLAR-C will carry three dedicated instruments; the Solar UV-Vis-IR Telescope (SUVIT), the EUV Spectroscopic Telescope (EUVST) and the High Resolution Coronal Imager (HCI), to jointly observe the entire visible solar atmosphere with essentially the same high spatial resolution (0.1-0.3 arcsec), performing high resolution spectroscopic measurements over all atmospheric regions and spectro-polarimetric measurements from the photosphere through the upper chromosphere. In addition, Solar-C will contribute to our understanding on the influence of the Sun-Earth environments with synergetic wide-field observations from ground-based and other space missions. Some leading science objectives and the mission concept, including designs of the three instruments aboard SOLAR-C will be presented.

  18. Synthesis of selectively 13C-labelled benzoic acid for nuclear magnetic resonance spectroscopic measurement of glycine conjugation activity

    International Nuclear Information System (INIS)

    Akira, Kazuki; Hasegawa, Hiroshi; Baba, Shigeo

    1995-01-01

    The synthesis of [4- 13 C]benzoic acid (BA) labelled in a single protonated carbon, for use as a probe to measure glycine conjugation activity by nuclear magnetic resonance (NMR) spectroscopy, has been reported. The labelled compound was prepared by a seven-step synthetic scheme on a relatively small scale using [2- 13 C] acetone as the source of label in overall yield of 16%. The usefulness of [4- 13 C]BA was demonstrated by the NMR spectroscopic monitoring of urinary excretion of [4- 13 C]hippuric acid in the rat administered with the labelled BA. (Author)

  19. ESTABLISHING A CONNECTION BETWEEN ACTIVE REGION OUTFLOWS AND THE SOLAR WIND: ABUNDANCE MEASUREMENTS WITH EIS/HINODE

    International Nuclear Information System (INIS)

    Brooks, David H.; Warren, Harry P.

    2011-01-01

    One of the most interesting discoveries from Hinode is the presence of persistent high-temperature high-speed outflows from the edges of active regions (ARs). EUV imaging spectrometer (EIS) measurements indicate that the outflows reach velocities of 50 km s -1 with spectral line asymmetries approaching 200 km s -1 . It has been suggested that these outflows may lie on open field lines that connect to the heliosphere, and that they could potentially be a significant source of the slow speed solar wind. A direct link has been difficult to establish, however. We use EIS measurements of spectral line intensities that are sensitive to changes in the relative abundance of Si and S as a result of the first ionization potential (FIP) effect, to measure the chemical composition in the outflow regions of AR 10978 over a 5 day period in 2007 December. We find that Si is always enhanced over S by a factor of 3-4. This is generally consistent with the enhancement factor of low FIP elements measured in situ in the slow solar wind by non-spectroscopic methods. Plasma with a slow wind-like composition was therefore flowing from the edge of the AR for at least 5 days. Furthermore, on December 10 and 11, when the outflow from the western side was favorably oriented in the Earth direction, the Si/S ratio was found to match the value measured a few days later by the Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer. These results provide strong observational evidence for a direct connection between the solar wind, and the coronal plasma in the outflow regions.

  20. Solar radiation modeling and measurements for renewable energy applications: data and model quality

    International Nuclear Information System (INIS)

    Myers, Daryl R.

    2005-01-01

    Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software for outdoor pyranometer calibrations are outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data

  1. Solar radiation modeling and measurements for renewable energy applications: data and model quality

    Energy Technology Data Exchange (ETDEWEB)

    Myers, D.R. [National Renewable Energy Laboratory, Golden, CO (United States)

    2005-07-01

    Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software for outdoor pyranometer calibrations are outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data. (author)

  2. A spectroscopic study on the effect of ultra-violet solar radiation in Antarctica on the human skin fibroblast cells

    Directory of Open Access Journals (Sweden)

    Tatsuyuki Yamamoto

    2013-11-01

    Full Text Available A study on the effect of the solar ultra-violet radiation on the human skin fibroblast cells revealed that the production of matrix metalloproteinase-2 was inhibited by the radiation. A CO2 incubator connected by optical fibers to a reflector telescope for collecting the solar light was built at Syowa station by the 49th Japanese Antarctica Research Expedition. The direction of the telescope was continuously controlled by a sun-tracker to follow the movement of the Sun automatically. The intensity of the collected light was monitored by a portable spectrophotometer housed inside. The human skin fibroblast cells were incubated in the CO2 chamber to investigate the effect of the solar radiation at Syowa station and were compared with those reference experiments at a laboratory in Japan. The results showed cell damage by strong UV radiation. The production of matrix metalloproteinase-2 was prompted by the moderate UV-B, but was inhibited by the strong UV-B radiation, as studied under laboratory conditions in Japan. The effect of strong solar radiation at Syowa station involving the radiation of UV-B region was estimated to be of the same extent of the radiation caused by an artificial UV-B light with the intensity more than 50 mJ/cm2.

  3. Measuring impact crater depth throughout the solar system

    Science.gov (United States)

    Robbins, Stuart J.; Watters, Wesley A.; Chappelow, John E.; Bray, Veronica J.; Daubar, Ingrid J.; Craddock, Robert A.; Beyer, Ross A.; Landis, Margaret E.; Ostrach, Lillian; Tornabene, Livio L.; Riggs, Jamie D.; Weaver, Brian P.

    2018-01-01

    One important, almost ubiquitous, tool for understanding the surfaces of solid bodies throughout the solar system is the study of impact craters. While measuring a distribution of crater diameters and locations is an important tool for a wide variety of studies, so too is measuring a crater's “depth.” Depth can inform numerous studies including the strength of a surface and modification rates in the local environment. There is, however, no standard data set, definition, or technique to perform this data‐gathering task, and the abundance of different definitions of “depth” and methods for estimating that quantity can lead to misunderstandings in and of the literature. In this review, we describe a wide variety of data sets and methods to analyze those data sets that have been, are currently, or could be used to derive different types of crater depth measurements. We also recommend certain nomenclature in doing so to help standardize practice in the field. We present a review section of all crater depths that have been published on different solar system bodies which shows how the field has evolved through time and how some common assumptions might not be wholly accurate. We conclude with several recommendations for researchers which could help different data sets to be more easily understood and compared.

  4. Noninvasive, near infrared spectroscopic-measured muscle pH and PO2 indicate tissue perfusion for cardiac surgical patients undergoing cardiopulmonary bypass

    Science.gov (United States)

    Soller, Babs R.; Idwasi, Patrick O.; Balaguer, Jorge; Levin, Steven; Simsir, Sinan A.; Vander Salm, Thomas J.; Collette, Helen; Heard, Stephen O.

    2003-01-01

    OBJECTIVE: To determine whether near infrared spectroscopic measurement of tissue pH and Po2 has sufficient accuracy to assess variation in tissue perfusion resulting from changes in blood pressure and metabolic demand during cardiopulmonary bypass. DESIGN: Prospective clinical study. SETTING: Academic medical center. SUBJECTS: Eighteen elective cardiac surgical patients. INTERVENTION: Cardiac surgery under cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: A near infrared spectroscopic fiber optic probe was placed over the hypothenar eminence. Reference Po2 and pH sensors were inserted in the abductor digiti minimi (V). Data were collected every 30 secs during surgery and for 6 hrs following cardiopulmonary bypass. Calibration equations developed from one third of the data were used with the remaining data to investigate sensitivity of the near infrared spectroscopic measurement to physiologic changes resulting from cardiopulmonary bypass. Near infrared spectroscopic and reference pH and Po2 measurements were compared for each subject using standard error of prediction. Near infrared spectroscopic pH and Po2 at baseline were compared with values during cardiopulmonary bypass just before rewarming commenced (hypotensive, hypothermic), after rewarming (hypotensive, normothermic) just before discontinuation of cardiopulmonary bypass, and at 6 hrs following cardiopulmonary bypass (normotensive, normothermic) using mixed-model analysis of variance. Near infrared spectroscopic pH and Po2 were well correlated with the invasive measurement of pH (R2 =.84) and Po2 (R 2 =.66) with an average standard error of prediction of 0.022 +/- 0.008 pH units and 6 +/- 3 mm Hg, respectively. The average difference between the invasive and near infrared spectroscopic measurement was near zero for both the pH and Po2 measurements. Near infrared spectroscopic Po2 significantly decreased 50% on initiation of cardiopulmonary bypass and remained depressed throughout the bypass and

  5. The SOLAR-C Mission: Science Objectives and Current Status

    Science.gov (United States)

    Suematsu, Y.; Solar-C Working Group

    2016-04-01

    The SOLAR-C is a Japan-led international solar mission for mid-2020s designed to investigate the magnetic activities of the Sun, focusing on the study in heating and dynamical phenomena of the chromosphere and corona, and to advance algorithms for predicting short and long term solar magnetic activities. For these purposes, SOLAR-C will carry three dedicated instruments; the Solar UV-Vis-IR Telescope (SUVIT), the EUV Spectroscopic Telescope (EUVST) and the High Resolution Coronal Imager (HCI), to jointly observe the entire visible solar atmosphere with essentially the same high spatial resolution (0.1"-0.3"), performing high resolution spectroscopic measurements over all atmospheric regions and spectro-polarimetric measurements from the photosphere through the upper chromosphere. SOLAR-C will also contribute to understand the solar influence on the Sun-Earth environments with synergetic wide-field observations from ground-based and other space missions.

  6. Soil sample moisture content as a function of time during oven drying for gamma-ray spectroscopic measurements

    International Nuclear Information System (INIS)

    Benke, R.R.; Kearfott, K.J.

    1999-01-01

    In routine gamma-ray spectroscopic analysis of collected soil samples, procedure often calls to remove soil moisture by oven drying overnight at a temperature of 100 deg. C . Oven drying not only minimizes the gamma-ray self-attenuation of soil samples due to the absence of water during the gamma-ray spectroscopic analysis, but also allows for a straightforward calculation of the specific activity of radionuclides in soil, historically based on the sample dry weight. Because radon exhalation is strongly dependent on moisture , knowledge of the oven-drying time dependence of the soil moisture content, combined with radon exhalation measurements during oven drying and at room temperature for varying soil moisture contents, would allow conclusions to be made on how the oven-drying radon exhalation rate depends on soil moisture content. Determinations of the oven-drying radon exhalation from soil samples allow corrections to be made for the immediate laboratory gamma-ray spectroscopy of radionuclides in the natural uranium decay chain. This paper presents the results of soil moisture content measurements during oven drying and suggests useful empirical fits to the moisture data

  7. Solar irradiance measurements from the Danish Galathea 3 expedition

    Energy Technology Data Exchange (ETDEWEB)

    Bason, Frank [SolData Instruments, Silkeborg (Denmark)

    2008-07-01

    The Danish Galathea 3 Expedition completed an eight month journey of exploration and discovery on April 25th, 2007, having set sail from Copenhagen on August 11th, 2006. SolData Instruments was privileged to be selected to contribute an ''optics table'' with pyranometers, ultraviolet, lux, sky luminance, PAR and other optical radiation detectors. These instruments recorded data continuously during the 100.000 kilometer voyage of the Royal Danish Navy vessel Vaedderen. The voyage provided global solar irradiance and other data as far north as the Arctic Circle near Greenland and as far south as Antarctica. The data collected was analyzed to validate a solar irradiance model described in this paper. A unique opportunity was also provided to check the performance of SolData photovoltaic pyranometers against data from a Kipp-Zonen CMll instrument. In addition to optical radiation, ionizing radiation and atmospheric pressure were also measured, and some interesting aspects of these measurements will also be mentioned. (orig.)

  8. Measurement of the ground state spectroscopic quadrupole moments of 191Os and 193Os

    International Nuclear Information System (INIS)

    Ernst, H.; Hagn, E.; Zech, E.

    1979-01-01

    Radioactive 191 Os and 193 Os nuclei have been aligned in an Os single crystal at temperatures down to 4 mK. From the temperature dependence of the γ-anisotropy the quadrupole frequencies vsub(Q) = e 2 qQ/h have been determined as vsub(Q)( 191 OsOs) = -278+-9 MHz and vsub(Q)( 193 OsOs) = -96+-15 MHz. With the known electric field gradient for OsOs of eq = (-4.54+-0.24) x 10 17 V/cm 2 the ground state spectroscopic quadrupole moments are deduced to be Q( 191 Os) = +2.53+-0.16 b and Q( 193 Os) = +0.87+-0.15 b. (orig.)

  9. A Peltier cooling diamond anvil cell for low-temperature Raman spectroscopic measurements

    Science.gov (United States)

    Noguchi, Naoki; Okuchi, Takuo

    2016-12-01

    A new cooling system using Peltier modules is presented for a low-temperature diamond anvil cell instrument. This cooling system has many advantages: it is vibration-free, low-cost, and compact. It consists of double-stacked Peltier modules and heat sinks, where a cooled ethylene glycol-water mixture flows through a chiller. Current is applied to the Peltier modules by two programmable DC power supplies. Sample temperature can be controlled within the range 210-300 K with a precision of ±0.1 K via a Proportional-Integral-Differential (PID) control loop. A Raman spectroscopic study for the H2O ice VII-VIII transition is shown as an example of an application of the Peltier cooling diamond anvil cell system.

  10. Spectroscopic measurements with a silicon drift detector having a continuous implanted drift cathode-voltage divider

    CERN Document Server

    Bonvicini, V; D'Acunto, L; Franck, D; Gregorio, A; Pihet, P; Rashevsky, A; Vacchi, A; Vinogradov, L I; Zampa, N

    2000-01-01

    A silicon drift detector (SDD) prototype where the drift electrode also plays the role of a high-voltage divider has been realised and characterised for spectroscopic applications at near-room temperatures. Among the advantages of this design, is the absence of metal on the sensitive surface which makes this detector interesting for soft X-rays. The detector prototype has a large sensitive area (2x130 mm sup 2) and the charge is collected by two anodes (butterfly-like detector). The energy resolution of a such a detector has been investigated at near-room temperatures using a commercial, hybrid, low-noise charge-sensitive preamplifier. The results obtained for the X-ray lines from sup 5 sup 5 Fe and sup 2 sup 4 sup 1 Am are presented.

  11. Measure Solar System Objects and Their Movements for Yourself!

    CERN Document Server

    Clark, John D

    2009-01-01

    Instead of taking somebody's word about the basic size and distances for the solar system's objects, this book shows amateur astronomers how to measure these things for themselves. This is an enriching experience for any amateur astronomer - to understand and personally measure fundamental astronomical quantities and distances. A basic knowledge of geometry is required, but it is amazing how simple the ideas can be. Readers are led through the details as gently as possible - and in a light-hearted way - presuming that most will have half-forgotten most of the mathematics. The practical astronomical equipment recommended is no more than a typical commercially-made amateur telescope and a camera of some sort - these days a webcam works very well. Apart from that all the reader will need is access to a computer with internet service, the know-how to download free software, and an enthusiasm to expand his knowledge of the basics of scientific astronomy.

  12. Predicting Atmospheric Ionization and Excitation by Precipitating SEP and Solar Wind Protons Measured By MAVEN

    Science.gov (United States)

    Jolitz, Rebecca; Dong, Chuanfei; Lee, Christina; Lillis, Rob; Brain, David; Curry, Shannon; Halekas, Jasper; Bougher, Stephen W.; Jakosky, Bruce

    2017-10-01

    Precipitating energetic particles ionize and excite planetary atmospheres, increasing electron content and producing aurora. At Mars, the solar wind and solar energetic particles (SEPs) can precipitate directly into the atmosphere because solar wind protons can charge exchange to become neutral and pass the magnetosheath, and SEPs are sufficiently energetic to cross the magnetosheath unchanged. We will compare ionization and Lyman alpha emission rates for solar wind and SEP protons during nominal solar activity and a CME shock front impact event on May 16 2016. We will use the Atmospheric Scattering of Protons and Energetic Neutrals (ASPEN) model to compare excitation and ionization rates by SEPs and solar wind protons currently measured by the SWIA (Solar Wind Ion Analyzer) and SEP instruments aboard the MAVEN spacecraft. Results will help quantify how SEP and solar wind protons influence atmospheric energy deposition during solar minimum.

  13. Solar neutrino measurements with Super-Kamiokande III

    International Nuclear Information System (INIS)

    Ikeda, Motoyasu

    2008-01-01

    The third phase of Super-Kamiokande experiment (SK-III) has been running since 12th July, 2006. The SK-III detector is achieved 40% photo-cathode coverage with 11,129 20-inch PMTs. One of the physics goals in SK-III is observing the transition of solar neutrino oscillations between vacuum and matter oscillation around 4MeV. From 24th January, 2007 to 2nd March, 2008, we obtained data of live-time 288.9 days with energy threshold 6.5MeV (Full Final sample: FF sample). For data with a lower energy threshold 5.0MeV, we needed remove high radon contaminated period from the FF sample, then we obtained another data sample (Radon reduced sample: RR sample) with live-time 191.7 days. The current measurements show that SK-III has already achieved a similar signal to noise ratio as SK-I for energy range from 5.0 to 20.0MeV, and the solar angle distribution of FF sample shows that the solar neutrino event rate also looks consistent with SK-I for energy range from 6.5 to 20.0MeV. As for the RR sample, although the vertex distribution of low energy events is not uniform in the detector and there are more BG events in the edge of fiducial volume, it is clear that SK-III BG level is smaller than that of SK-I in the central region of the detector. Finally, the future plan for lowering the energy threshold shows a 2a discovery potential of the energy spectrum upturn with 3 years of observation after both software and hardware improvements.

  14. Quantum chemical calculations and spectroscopic measurements of spectroscopic and thermodynamic properties of given uranyl complexes in aqueous solutions with possible environmental and industrial applications

    Directory of Open Access Journals (Sweden)

    Višňak Jakub

    2016-01-01

    Full Text Available A brief introduction into computational methodology and preliminary results for spectroscopic (excitation energies, vibrational frequencies in ground and excited electronic states and thermodynamic (stability constants, standard enthalpies and entropies of complexation reactions properties of some 1:1, 1:2 and 1:3 uranyl sulphato- and selenato- complexes in aqueos solutions will be given. The relativistic effects are included via Effective Core Potential (ECP, electron correlation via (TDDFT/B3LYP (dispersion interaction corrected and solvation is described via explicit inclusion of one hydration sphere beyond the coordinated water molecules. We acknowledge limits of this approximate description – more accurate calculations (ranging from semi-phenomenological two-component spin-orbit coupling up to four-component Dirac-Coulomb-Breit hamiltonian and Molecular Dynamics simulations are in preparation. The computational results are compared with the experimental results from Time-resolved Laser-induced Fluorescence Spectroscopy (TRLFS and UV-VIS spectroscopic studies (including our original experimental research on this topic. In case of the TRLFS and UV-VIS speciation studies, the problem of complex solution spectra decomposition into individual components is ill-conditioned and hints from theoretical chemistry could be very important. Qualitative agreement between our quantum chemical calculations of the spectroscopic properties and experimental data was achieved. Possible applications for geochemical modelling (e.g. safety studies of nuclear waste repositories, modelling of a future mining site and analytical chemical studies (including natural samples are discussed.

  15. In vivo measurement of regional brain metabolic response to hyperventilation using magnetic resonance: proton echo planar spectroscopic imaging (PEPSI).

    Science.gov (United States)

    Posse, S; Dager, S R; Richards, T L; Yuan, C; Ogg, R; Artru, A A; Müller-Gärtner, H W; Hayes, C

    1997-06-01

    A new rapid spectroscopic imaging technique with improved sensitivity and lipid suppression, referred to as Proton Echo Planar Spectroscopic Imaging (PEPSI), has been developed to measure the 2-dimensional distribution of brain lactate increases during hyperventilation on a conventional clinical scanner equipped with a head surface coil phased array. PEPSI images (nominal voxel size: 1.125 cm3) in five healthy subjects from an axial section approximately 20 mm inferior to the intercommissural line were obtained during an 8.5-min baseline period of normocapnia and during the final 8.5 min of a 10-min period of capnometry-controlled hyperventilation (end-tidal PCO2 of 20 mmHg). The lactate/N-acetyl aspartate signal increased significantly from baseline during hyperventilation for the insular cortex, temporal cortex, and occipital regions of both the right and left hemisphere, but not in the basal ganglia. Regional or hemispheric right-to-left differences were not found. The study extends previous work using single-voxel MR spectroscopy to dynamically study hyperventilation effects on brain metabolism.

  16. Measuring solar UV radiation with EBT radiochromic film

    International Nuclear Information System (INIS)

    Butson, Ethan T; Cheung Tsang; Yu, Peter K N; Butson, Martin J

    2010-01-01

    Ultraviolet radiation dosimetry has been performed with the use of a radiochromic film dosimeter called Gafchromic EBT for solar radiation exposure. The film changes from a clear colour to blue colour when exposed to ultraviolet radiation and results have shown that the colour change is reproducible within ±10% at 5 kJ m -2 UV exposure under various conditions of solar radiation. Parameters tested included changes in season (summer versus winter exposure), time of day, as well as sky conditions such as cloudy skies versus clear skies. As the radiochromic films' permanent colour change occurs in the visible wavelengths the film can be analysed with a desktop scanner with the most sensitive channel for analysis being the red component of the signal. Results showed that an exposure of 5 kJ m -2 (approximately 1 h exposure in full sun during summer) produced an approximate 0.28 change in the net OD when analysed in reflection mode on the desktop scanner which is significant darkening. The main advantages of this film type, and thus the new EBT2 film which has replaced EBT for measurement of UV exposure, is the visible colour change and thus easy analysis using a desktop scanner, its uniformity in response and its robust physical strength for use in outside exposure situations. (note)

  17. Global Analysis of Solar Neutrino Oscillations Including SNO CC Measurement

    CERN Document Server

    Bahcall, J N; Peña-Garay, C; Bahcall, John N; Peña-Garay, Carlos

    2001-01-01

    For active and sterile neutrinos, we present the globally allowed solutions for two neutrino oscillations. We include the SNO CC measurement and all other relevant solar neutrino and reactor data. Five active neutrino oscillation solutions (LMA, LOW, SMA, VAC, and Just So2) are currently allowed at 3 sigma; three sterile neutrino solutions (Just So2, SMA, and VAC) are allowed at 3 sigma. The goodness of fit is satisfactory for all eight solutions. We also investigate the robustness of the allowed solutions by carrying out global analyses with and without: 1) imposing solar model constraints on the 8B neutrino flux, 2) including the Super-Kamiokande spectral energy distribution and day-night data, 3) using an enhanced CC cross section for deuterium (due to radiative corrections), and 4) a optimistic, hypothetical reduction by a factor of three of the error of the SNO CC rate. For every analysis strategy used in this paper, the most favored solutions all involve large mixing angles: LMA, LOW, or VAC. The favore...

  18. New Solar Irradiance Measurements from the Miniature X-Ray Solar Spectrometer Cubesat

    Energy Technology Data Exchange (ETDEWEB)

    Woods, Thomas N.; Jones, Andrew; Kohnert, Richard; Mason, James Paul; Moore, Christopher S.; Palo, Scott; Rouleau, Colden [University of Colorado, Boulder, CO (United States); Caspi, Amir [Southwest Research Institute, Boulder, CO (United States); Chamberlin, Phillip C. [NASA Goddard Space Flight Center, Greenbelt, MD (United States); Solomon, Stanley C. [National Center for Atmospheric Research, Boulder, CO (United States); Machol, Janet; Viereck, Rodney [NOAA Space Weather Prediction Center, Boulder, CO (United States)

    2017-02-01

    The goal of the Miniature X-ray Solar Spectrometer ( MinXSS ) CubeSat is to explore the energy distribution of soft X-ray (SXR) emissions from the quiescent Sun, active regions, and during solar flares and to model the impact on Earth's ionosphere and thermosphere. The energy emitted in the SXR range (0.1–10 keV) can vary by more than a factor of 100, yet we have limited spectral measurements in the SXRs to accurately quantify the spectral dependence of this variability. The MinXSS primary science instrument is an Amptek, Inc. X123 X-ray spectrometer that has an energy range of 0.5–30 keV with a nominal 0.15 keV energy resolution. Two flight models have been built. The first, MinXSS -1, has been making science observations since 2016 June 9 and has observed numerous flares, including more than 40 C-class and 7 M-class flares. These SXR spectral measurements have advantages over broadband SXR observations, such as providing the capability to derive multiple-temperature components and elemental abundances of coronal plasma, improved irradiance accuracy, and higher resolution spectral irradiance as input to planetary ionosphere simulations. MinXSS spectra obtained during the M5.0 flare on 2016 July 23 highlight these advantages and indicate how the elemental abundance appears to change from primarily coronal to more photospheric during the flare. MinXSS -1 observations are compared to the Geostationary Operational Environmental Satellite ( GOES ) X-ray Sensor (XRS) measurements of SXR irradiance and estimated corona temperature. Additionally, a suggested improvement to the calibration of the GOES XRS data is presented.

  19. Solar Irradiance Measurements Using Smart Devices: A Cost-Effective Technique for Estimation of Solar Irradiance for Sustainable Energy Systems

    Directory of Open Access Journals (Sweden)

    Hussein Al-Taani

    2018-02-01

    Full Text Available Solar irradiance measurement is a key component in estimating solar irradiation, which is necessary and essential to design sustainable energy systems such as photovoltaic (PV systems. The measurement is typically done with sophisticated devices designed for this purpose. In this paper we propose a smartphone-aided setup to estimate the solar irradiance in a certain location. The setup is accessible, easy to use and cost-effective. The method we propose does not have the accuracy of an irradiance meter of high precision but has the advantage of being readily accessible on any smartphone. It could serve as a quick tool to estimate irradiance measurements in the preliminary stages of PV systems design. Furthermore, it could act as a cost-effective educational tool in sustainable energy courses where understanding solar radiation variations is an important aspect.

  20. Properties of an impulsive compact solar flare determined from Solar Maximum Mission X-ray measurements

    Science.gov (United States)

    Linford, G. A.; Wolfson, C. J.

    1988-01-01

    Soft X-ray, hard X-ray magnetogram, and H-alpha data have been analyzed for an impulsive compact solar flare which occurred on May 21, 1985. The derived flare loop dimensions are about 20,000 km length and about 150 km diameter. Measurements of line ratios from the Mg XI ion indicate that the plasma density varied from about 4 x 10 to the 12th/cu cm early in the flare to about 10 to the 12th/cu cm during the flare decay. The initial temperature of this plasma was about 8 x 10 to the 6th K and dropped to about 5 x 10 to the 6th K during the decay phase. The simplest interpretation of the event is one in which the source of the soft X-ray flare emission is confined to a thin loop of very high density.

  1. Properties of an impulsive compact solar flare determined from Solar Maximum Mission X-ray measurements

    International Nuclear Information System (INIS)

    Linford, G.A.; Wolfson, C.J.

    1988-01-01

    Soft X-ray, hard X-ray magnetogram, and H-alpha data have been analyzed for an impulsive compact solar flare which occurred on May 21, 1985. The derived flare loop dimensions are about 20,000 km length and about 150 km diameter. Measurements of line ratios from the Mg XI ion indicate that the plasma density varied from about 4 x 10 to the 12th/cu cm early in the flare to about 10 to the 12th/cu cm during the flare decay. The initial temperature of this plasma was about 8 x 10 to the 6th K and dropped to about 5 x 10 to the 6th K during the decay phase. The simplest interpretation of the event is one in which the source of the soft X-ray flare emission is confined to a thin loop of very high density. 44 references

  2. Properties of an impulsive compact solar flare determined from Solar Maximum Mission X-ray measurements

    Energy Technology Data Exchange (ETDEWEB)

    Linford, G.A.; Wolfson, C.J.

    1988-08-01

    Soft X-ray, hard X-ray magnetogram, and H-alpha data have been analyzed for an impulsive compact solar flare which occurred on May 21, 1985. The derived flare loop dimensions are about 20,000 km length and about 150 km diameter. Measurements of line ratios from the Mg XI ion indicate that the plasma density varied from about 4 x 10 to the 12th/cu cm early in the flare to about 10 to the 12th/cu cm during the flare decay. The initial temperature of this plasma was about 8 x 10 to the 6th K and dropped to about 5 x 10 to the 6th K during the decay phase. The simplest interpretation of the event is one in which the source of the soft X-ray flare emission is confined to a thin loop of very high density. 44 references.

  3. Multifractality as a Measure of Complexity in Solar Flare Activity

    Science.gov (United States)

    Sen, Asok K.

    2007-03-01

    In this paper we use the notion of multifractality to describe the complexity in H α flare activity during the solar cycles 21, 22, and 23. Both northern and southern hemisphere flare indices are analyzed. Multifractal behavior of the flare activity is characterized by calculating the singularity spectrum of the daily flare index time series in terms of the Hölder exponent. The broadness of the singularity spectrum gives a measure of the degree of multifractality or complexity in the flare index data. The broader the spectrum, the richer and more complex is the structure with a higher degree of multifractality. Using this broadness measure, complexity in the flare index data is compared between the northern and southern hemispheres in each of the three cycles, and among the three cycles in each of the two hemispheres. Other parameters of the singularity spectrum can also provide information about the fractal properties of the flare index data. For instance, an asymmetry to the left or right in the singularity spectrum indicates a dominance of high or low fractal exponents, respectively, reflecting a relative abundance of large or small fluctuations in the total energy emitted by the flares. Our results reveal that in the even (22nd) cycle the singularity spectra are very similar for the northern and southern hemispheres, whereas in the odd cycles (21st and 23rd) they differ significantly. In particular, we find that in cycle 21, the northern hemisphere flare index data have higher complexity than its southern counterpart, with an opposite pattern prevailing in cycle 23. Furthermore, small-scale fluctuations in the flare index time series are predominant in the northern hemisphere in the 21st cycle and are predominant in the southern hemisphere in the 23rd cycle. Based on these findings one might suggest that, from cycle to cycle, there exists a smooth switching between the northern and southern hemispheres in the multifractality of the flaring process. This new

  4. Spectroscopic and physicochemical measurements for on-line monitoring of used nuclear fuel separation processes

    Energy Technology Data Exchange (ETDEWEB)

    Nee, Ko; Nilsson, M. [Department of Chemical Engineering and Material Science, University of California, 916 Engineering Tower, Irvine, CA 92697-2575 (United States); Bryan, S.; Levitskaia, T. [Pacific Northwest National Laboratory, PO BOX 999, Richland, CA 99352 (United States)

    2013-07-01

    Separation processes for used nuclear fuel are often complicated and challenging due to the high constraints in purity of the products and safeguards of the process streams. In order to achieve a safe, secure and efficient separation process, the liquid streams in the separation process require close monitoring. Due to the high radiation environment, sampling of the materials is difficult. Availability of a detection technique that is remote, non-destructive and can avoid time-delay caused by retrieving samples would be beneficial and could minimize the exposure to personnel and provide material accountancy to avoid diversion (non-proliferation). For example, Ultra Violet (UV), Visible (Vis), Near-Infrared (NIR) and Raman spectroscopy that detect and quantify elements present in used nuclear fuel, e.g. lanthanides, actinides and molecules such as nitrate, can be used. In this work, we have carried out NIR and Raman spectroscopy to study aqueous solutions composed of different concentrations of nitric acid, sodium nitrate, and neodymium at varied temperatures. A chemometric model for online monitoring based on the PLS-Toolbox (MATLAB) software has been developed and validated to provide chemical composition of process streams based on spectroscopic data. In conclusion, both of our NIR and Raman spectra were useful for H{sup +} and NO{sub 3} prediction, and only NIR was helpful for the Nd{sup 3+} prediction.

  5. Infrared Spectroscopic Measurement of Titanium Dioxide Nanoparticle Shallow Trap State Energies

    Science.gov (United States)

    2010-02-10

    microscopy grids. The grids that I used were a #150 copper mesh coated with a varnish support film layer, the Electron Microscopy Science’s model FCF150-Cu...Vaimakis, T.; Ladas, S.; Trapalis, C., Study of fluorine -doped TiO2 sol-gel thin coatings. Journal of Solar Energy Engineering-Transactions of the Asme...2008, 130 (4), 1-5. 121. Todorova, N.; Giannakopoulou, T.; Romanos, G.; Vaimakis, T.; Yu, J. G.; Trapalis, C., Preparation of fluorine -doped TiO2

  6. SOLAR WIND HEAVY IONS OVER SOLAR CYCLE 23: ACE/SWICS MEASUREMENTS

    International Nuclear Information System (INIS)

    Lepri, S. T.; Landi, E.; Zurbuchen, T. H.

    2013-01-01

    Solar wind plasma and compositional properties reflect the physical properties of the corona and its evolution over time. Studies comparing the previous solar minimum with the most recent, unusual solar minimum indicate that significant environmental changes are occurring globally on the Sun. For example, the magnetic field decreased 30% between the last two solar minima, and the ionic charge states of O have been reported to change toward lower values in the fast wind. In this work, we systematically and comprehensively analyze the compositional changes of the solar wind during cycle 23 from 2000 to 2010 while the Sun moved from solar maximum to solar minimum. We find a systematic change of C, O, Si, and Fe ionic charge states toward lower ionization distributions. We also discuss long-term changes in elemental abundances and show that there is a ∼50% decrease of heavy ion abundances (He, C, O, Si, and Fe) relative to H as the Sun went from solar maximum to solar minimum. During this time, the relative abundances in the slow wind remain organized by their first ionization potential. We discuss these results and their implications for models of the evolution of the solar atmosphere, and for the identification of the fast and slow wind themselves.

  7. Optical properties of LiGaS{sub 2}: an ab initio study and spectroscopic ellipsometry measurement

    Energy Technology Data Exchange (ETDEWEB)

    Atuchin, V V [Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk 90, 630090 (Russian Federation); Lin, Z S [Beijing Center for Crystal R and D, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, PO Box 2711, Beijing 100190 (China); Isaenko, L I; Lobanov, S I [Laboratory of Crystal Growth, Institute of Geology and Mineralogy, SB RAS, Novosibirsk 90, 630090 (Russian Federation); Kesler, V G [Laboratory of Physical Bases of Integrated Microelectronics, Institute of Semiconductor Physics, SB RAS, Novosibirsk 90, 630090 (Russian Federation); Kruchinin, V N, E-mail: zslin@mail.ipc.ac.c [Laboratory for Ellipsometry of Semiconductor Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk 90, 630090 (Russian Federation)

    2009-11-11

    Electronic and optical properties of lithium thiogallate crystal, LiGaS{sub 2}, have been investigated by both experimental and theoretical methods. The plane-wave pseudopotential method based on DFT theory has been used for band structure calculations. The electronic parameters of Ga 3d orbitals have been corrected by the DFT+U methods to be consistent with those measured with x-ray photoemission spectroscopy. Evolution of optical constants of LiGaS{sub 2} over a wide spectral range was determined by developed first-principles theory and dispersion curves were compared with optical parameters defined by spectroscopic ellipsometry in the photon energy range 1.2-5.0 eV. Good agreement has been achieved between theoretical and experimental results.

  8. Optical constants of CH3NH3PbBr3 perovskite thin films measured by spectroscopic ellipsometry

    KAUST Repository

    Alias, Mohd Sharizal

    2016-07-14

    The lack of optical constants information for hybrid perovskite of CH3NH3PbBr3 in thin films form can delay the progress of efficient LED or laser demonstration. Here, we report on the optical constants (complex refractive index and dielectric function) of CH3NH3PbBr3 perovskite thin films using spectroscopic ellipsometry. Due to the existence of voids, the refractive index of the thin films is around 8% less than the single crystals counterpart. The energy bandgap is around 2.309 eV as obtained from photoluminescence and spectrophotometry spectra, and calculated from the SE analysis. The precise measurement of optical constants will be useful in designing optical devices using CH3NH3PbBr3 thin films.

  9. Measurements and IRI Model Predictions During the Recent Solar Minimum

    Science.gov (United States)

    Bilitza, Dieter; Brown, Steven A.; Wang, Mathew Y.; Souza, Jonas R.; Roddy, Patrick A.

    2012-01-01

    Cycle 23 was exceptional in that it lasted almost two years longer than its predecessors and in that it ended in an extended minimum period that proved all predictions wrong. Comparisons of the International Reference Ionosphere (IRI) with CHAMP and GRACE in-situ measurements of electron density during the minimum have revealed significant discrepancies at 400-500 km altitude. Our study investigates the causes for these discrepancies with the help of ionosonde and Planar Langmuir Probe (PLP) data from the Communications/Navigation Outage Forecasting System (C/NOFS) satellite. Our C/NOFS comparisons confirm the earlier CHAMP and GRACE results. But the ionosonde measurements of the F-peak plasma frequency (foF2) show generally good agreement throughout the whole solar cycle. At mid-latitude stations yearly averages of the data-model difference are within 10% and at low latitudes stations within 20%. The 60-70% differences found at 400-500 km altitude are not seen at the F peak. We will discuss how these seemingly contradicting results from the ionosonde and in situ data-model comparisons can be explained and which parameters need to be corrected in the IRI model.

  10. Measurements and modeling of 16O12C17O spectroscopic parameters at 2 μm

    Science.gov (United States)

    Jacquemart, David; Sung, Keeyoon; Coleman, Max; Crawford, Timothy; Brown, Linda R.; Mantz, Arlan W.; Smith, Mary Ann H.

    2017-12-01

    The lack of spectroscopic measurements for rare CO2 isotopologues was the main motivation of this work. In our present study we report line intensity measurements for 16O12C17O made with a high resolution Fourier transform spectrometer (Bruker IFS-125HR) and a 21 m path cryogenic Herriott cell at Jet Propulsion Laboratory. For this, a 17O-enriched CO2 gas sample was used, which comes as a mixture of primary and several minor CO2 isotopologues. The mole fraction of the 16O12C17O isotopologue in the mixture was determined to be 0.3991 by mass spectrometry from a Stable Isotope Ratio Mass Spectrometer (SIRMS) under stochastic distribution assumption at thermal equilibrium. Since the collisional narrowing effect was observed, the Rautian molecular line shape profile was systematically adopted instead of the Voigt profile. Absolute line positions were also investigated by performing a wavenumber calibration based on CO, HCl and a few well-known 16O12C16O transitions. Finally, around 1000 transitions were studied between 4604 and 5126 cm-1 involving 15 bands of the 16O12C17O isotopologue. All the measured line intensities were renormalized to be the values for 100% pure isotopologue sample. Transition dipole moments and Herman-Wallis factors were derived enabling a global comparison with theoretical calculations and predictions for the 15 bands of the 16O12C17O isotopologue. For the measured line positions, the absolute accuracy is around 2×10-4 cm-1. The accuracies of retrieved line intensities are 2 - 5% for five cold and two hot bands, and 6-30% for eight other weaker hot bands. Results from this work were in a good agreement with HITRAN 2012 for positions, but showed rather significant discrepancies for line intensities. An extensive line list was generated from new experimental measurements in order to improve and validate spectroscopic knowledge of 12C16O17O isotopologue in support of atmospheric remote sensing for the Earth (e.g., OCO-2 mission), Mars and Venus.

  11. M-line spectroscopic, spectroscopic ellipsometric and microscopic measurements of optical waveguides fabricated by MeV-energy N{sup +} ion irradiation for telecom applications

    Energy Technology Data Exchange (ETDEWEB)

    Bányász, I., E-mail: banyasz@sunserv.kfki.hu [Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O.B. 49, H-1525, Budapest (Hungary); Berneschi, S. [“Enrico Fermi” Center for Study and Research, Piazza del Viminale 2, 00184 Roma (Italy); MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Fried, M.; Lohner, T. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.B. 49, H-1525, Budapest (Hungary); Conti, G. Nunzi; Righini, G.C.; Pelli, S. [MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Zolnai, Z. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.B. 49, H-1525, Budapest (Hungary)

    2013-08-31

    Irradiation with N{sup +} ions of the 1.5–3.5 MeV energy range was applied to optical waveguide formation. Planar and channel waveguides have been fabricated in an Er-doped tungsten–tellurite glass, and in both types of bismuth germanate (BGO) crystals: Bi{sub 4}Ge{sub 3}O{sub 12} (eulytine) and Bi{sub 12}GeO{sub 20} (sillenite). Multi-wavelength m-line spectroscopy and spectroscopic ellipsometry were used for the characterisation of the ion beam irradiated waveguides. Planar waveguides fabricated in the Er-doped tungsten–tellurite glass using irradiation with N{sup +} ions at 3.5 MeV worked even at the 1550 nm telecommunication wavelength. 3.5 MeV N{sup +} ion irradiated planar waveguides in eulytine-type BGO worked up to 1550 nm and those in sillenite-type BGO worked up to 1330 nm. - Highlights: ► Waveguides were fabricated in glass and crystals using MeV energy N{sup +} ions. ► SRIM simulation and spectroscopic ellipsometry yielded similar waveguide structures. ► Multi-wavelength m-line spectroscopy was used to study the waveguides. ► Waveguides fabricated in an Er-doped tungsten–tellurite glass worked up to 1.5 μm. ► Waveguides in Bi{sub 12}GeO{sub 20} remained operative up to 1.5 μm.

  12. Study on photoelectric parameter measurement method of high capacitance solar cell

    Science.gov (United States)

    Zhang, Junchao; Xiong, Limin; Meng, Haifeng; He, Yingwei; Cai, Chuan; Zhang, Bifeng; Li, Xiaohui; Wang, Changshi

    2018-01-01

    The high efficiency solar cells usually have high capacitance characteristic, so the measurement of their photoelectric performance usually requires long pulse width and long sweep time. The effects of irradiance non-uniformity, probe shielding and spectral mismatch on the IV curve measurement are analyzed experimentally. A compensation method for irradiance loss caused by probe shielding is proposed, and the accurate measurement of the irradiance intensity in the IV curve measurement process of solar cell is realized. Based on the characteristics that the open circuit voltage of solar cell is sensitive to the junction temperature, an accurate measurement method of the temperature of solar cell under continuous irradiation condition is proposed. Finally, a measurement method with the characteristic of high accuracy and wide application range for high capacitance solar cell is presented.

  13. Solar energy plant as a complement to a conventional heating system: Measurement of the storage and consumption of solar energy

    Science.gov (United States)

    Doering, E.; Lippe, W.

    1982-08-01

    The technical and economic performances of a complementary solar heating installation for a new swimming pool added to a two-floor dwelling were examined after measurements were taken over a period of 12 months and analyzed. In particular, the heat absorption and utilization were measured and modifications were carried out to improve pipe insulation and regulation of mixer valve motor running and volume flow. The collector system efficiency was evaluated at 15.4%, the proportion of solar energy of the total consumption being 6.1%. The solar plant and the measuring instruments are described and recommendations are made for improved design and performance, including enlargement of the collector surface area, further modification of the regulation system, utilization of temperature stratification in the storage tanks and avoiding mutual overshadowing of the collectors.

  14. Effect of radiative trapping on measurement of the spectroscopic properties of Yb sup 3 sup + :phosphate glasses

    CERN Document Server

    Dai Shi Xun; Wen Lei; Hu Li Li; Jiang Zhong Hon

    2003-01-01

    The effect of radiative trapping on measurement of the spectroscopic properties of Yb sup 3 sup + -doped phosphate glasses was investigated as a function of Yb sup 3 sup + concentration at different thicknesses. It was found that radiative trapping exists generally in Yb sup 3 sup + :phosphate glasses, even at low concentration. As a result, the measured lifetime of Yb sup 3 sup + in phosphate glasses is usually larger than the calculated one. The maximum discrepancies between them at high concentration are found to be <42%. The calculated lifetime should be used as a reference in determining the true value of the measured lifetime because of it being lengthened largely by radiative trapping. On the other hand, the shape of fluorescence spectrum exhibits remarkable changes due to the radiative trapping. What is more, the intensity increase of DELTA lambda sub e sub f sub f at high concentration is greater than that of low doping. The DELTA lambda sub e sub f sub f increases 36% from 53 to 72 nm with thickn...

  15. Procedure for measuring the solar reflectance of flat or curved roofing assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Levinson, Ronnen [Heat Island Group, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Stern, Stephanie [Cool Roof Rating Council, Oakland, CA 94612 (United States)

    2008-07-15

    The widely used methods to measure the solar reflectance of roofing materials include ASTM standards E903 (spectrometer), C1549 (reflectometer), and E1918 (pyranometer). Standard E903 uses a spectrometer with an integrating sphere to measure the solar spectral reflectance of an area approximately 0.1 cm{sup 2}. The solar spectral reflectance is then weighted with a solar spectral irradiance to calculate the solar reflectance. Standard C1549 uses a reflectometer to measure the solar reflectance of an area approximately 5 cm{sup 2}. Both E903 and C1549 are best suited to measurement of the solar reflectance of flat, homogeneous surfaces. Standard E1918 uses a pyranometer to measure the solar reflectance of an area approximately 10 m{sup 2}, and is best applied to large surfaces that may also be rough and/or non-uniform. We describe a technique that uses a pyranometer to measure the solar reflectance of a uniform or variegated sample with diffusely reflective surface of an area of approximately 1 m{sup 2}, and use this technique (referred to as E1918A) to measure the solar reflectances of low- and high-profile tile assemblies. For 10 large (10 m{sup 2}) tile assemblies whose E1918 solar reflectances ranged from 0.10 to 0.50, the magnitude of the difference between the E1918A and E1918 measurements did not exceed 0.02 for unicolor assemblies, and did not exceed 0.03 for multicolor assemblies. (author)

  16. Electrochemical vs X-ray Spectroscopic Measurements of NiFe(CN)6 Crystals

    Science.gov (United States)

    Peecher, Benjamin; Hampton, Jennifer

    Pseudocapacitive materials like hexacyanoferrate have greater energy storage capabilities than standard capacitors while maintaining an ability to charge and discharge quickly. We modify the surface of an electrodeposited Ni thin film with a layer of hexacyanoferrate. Charging and discharging these modified films using cyclic voltammetry (CV) allows us to measure the electrochemically active Fe in the film. To determine how closely this resembles the full amount of Fe in the film, we measure the films' composition using particle-induced x-ray emission (PIXE). We also vary the amount of Ni deposited, both to compare the electrolysis value of charge deposited to the PIXE measurement of Ni in the film, and also to measure how varying the thickness of the Ni surface affects the presence of Fe in the film. Comparisons of the CV and PIXE measurements show agreement in Ni levels but disagreement in Fe levels. PIXE measurements of Fe in the film have positive correlation with Ni in the film. This correlation between PIXE measurements of Ni and Fe suggests that PIXE provides a reliable measure of Fe in the film. This implies that a variable proportion of total Fe in a given film is electrochemically active. This research was made possible by the Hope College Department of Physics Frissel Research Fund and the National Science Foundation under Grants RUI-DMR-1104725, MRI-CHE-0959282, and MRI/RUI-PHY-0319523.

  17. Design and measured performance of a solar chimney for natural-circulation solar-energy dryers

    International Nuclear Information System (INIS)

    Ekechukwu, O.V.; Norton, B.

    1995-10-01

    The design and construction of a solar chimney which was undertaken as part of a study on natural-circulation solar-energy dryers is reported. The experimental solar chimney consists of a 5.3m high and 1.64m diameter cylindrical polyethylene-clad vertical chamber, supported structurally by steel framework and draped internally with a selectively-absorbing surface. The performance of the chimney which was monitored extensively with and without the selective surface in place (to study the effectiveness of this design option) is also reported. (author). 14 refs, 7 figs

  18. Simulation of a method for determining one-dimensional {sup 137}Cs distribution using multiple gamma spectroscopic measurements with an adjustable cylindrical collimator and center shield

    Energy Technology Data Exchange (ETDEWEB)

    Whetstone, Z.D.; Dewey, S.C. [Radiological Health Engineering Laboratory, Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, 1906 Cooley Building, Ann Arbor, MI 48109-2104 (United States); Kearfott, K.J., E-mail: kearfott@umich.ed [Radiological Health Engineering Laboratory, Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, 1906 Cooley Building, Ann Arbor, MI 48109-2104 (United States)

    2011-05-15

    With multiple in situ gamma spectroscopic measurements obtained with an adjustable cylindrical collimator and a circular shield, the arbitrary one-dimensional distribution of radioactive material can be determined. The detector responses are theoretically calculated, field measurements obtained, and a system of equations relating detector response to measurement geometry and activity distribution solved to estimate the distribution. This paper demonstrates the method by simulating multiple scenarios and providing analysis of the system conditioning.

  19. Solar neutrino flux measurements by the Soviet-American Gallium Experiment (SAGE) for half the 22-year solar cycle

    International Nuclear Information System (INIS)

    Abdurashitov, J.N.; Veretenkin, E.P.; Vermul, V.M.; Gavrin, V.N.; Girin, S.V.; Gorbachev, V.V.; Gurkina, P.P.; Zatsepin, G.T.; Ibragimova, T.V.; Kalikhov, A.V.; Knodel, T.V.; Mirmov, I.N.; Khairnasov, N.G.; Shikhin, A.A.; Yants, V.E.; Bowles, T.J.; Teasdale, W.A.; Nico, J.S.; Wilkerson, J.F.; Cleveland, B.T.

    2002-01-01

    We present measurements of the solar neutrino capture rate on metallic gallium in the Soviet-American gallium experiment (SAGE) over a period of slightly more than half the 22-year solar cycle. A combined analysis of 92 runs over the twelve-year period from January 1990 until December 2001 yields a capture rate of 70.8 +5.3 -5.2 (stat) +3.7 -3.2 (sys) SNU for solar neutrinos with energies above 0.233 MeV. This value is slightly more than half the rate predicted by the standard solar model, 130 SNU. We present the results of new runs since April 1998 and analyze all runs combined by years, months, and bimonthly periods beginning in 1990. A simple analysis of the SAGE results together with the results of other solar neutrino experiments gives an estimate of (4.6 ± 1.2) x 10 10 neutrinos cm -2 s -1 for the flux of the electron pp neutrinos that reach the Earth without changing their flavor. The flux of the pp neutrinos produced in thermonuclear reactions in the Sun is estimated to be (7.6 ± 2.0) x 10 10 neutrinos cm -2 s -1 , in agreement with the value of (5.95 ± 0.06) x 10 10 neutrinos cm -2 s -1 predicted by the standard solar model

  20. VUV spectroscopic measurement in current drive experiments in TRIAM-1M

    International Nuclear Information System (INIS)

    Hara, Shigemitsu; Kawasaki, Shoji; Jotaki, Eriko; Moriyama, Shin-ichi; Nagao, Akihiro; Nakamura, Kazuo; Nakamura, Yukio; Hiraki, Naoji; Itoh, Satoshi

    1991-01-01

    VUV spectrum and time evolution of line intensity were measured. Steady-state transport equation was solved numerically, and the solution was qualitatively compared with the experimental results. (author)

  1. Spectroscopic measurements of the density and electronic temperature at the plasma edge in Tore Supra

    International Nuclear Information System (INIS)

    Lediankine, A.

    1996-01-01

    The profiles of temperature and electronic density at the plasma edge are important to study the wall-plasma interaction and the radiative layers in the Tokamak plasmas. The laser ablation technique of the lithium allows to measure the profile of electronic density. To measure the profile of temperature, it has been used for the first time, the injection of a fluorine neutral atoms beam. The experiments, the results are described in this work. (N.C.)

  2. X ray and EUV spectroscopic measurements of highly charged tungsten ions relevant to fusion plasmas

    International Nuclear Information System (INIS)

    Radtke, R; Biedermann, C; Mandelbaum, P; Schwob, J L

    2007-01-01

    Using high-resolution x ray and extreme ultraviolet (EUV) spectrometry, the line emission of W 28+ - W 50+ ions was measured at the Berlin Electron Beam Ion Trap (EBIT). Our study encompasses a wide range of wavelengths (5-800 A) and includes the observation of electric and magnetic dipole lines. The results of our measurements are compared with predicted transition wavelengths from ab initioatomic structure calculations

  3. Mobile CARS - IRS Instrument for Simultaneous Spectroscopic Measurement of Multiple Properties in Gaseous Flows

    Science.gov (United States)

    Bivolaru, Daniel; Lee, Joseph W.; Jones, Stephen B.; Tedder, Sarah A.; Danehy, Paul M.; Weikl, M. C.; Magnotti, G.; Cutler, Andrew D.

    2007-01-01

    This paper describes a measurement system based on the dual-pump coherent anti-Stokes Raman spectroscopy (CARS) and interferometric Rayleigh scattering (IRS) methods. The IRS measurement is performed simultaneously with the CARS measurement using a common green laser beam as a narrow-band light source. The mobile CARS-IRS instrument is designed for the use both in laboratories as well as in ground-based combustion test facilities. Furthermore, it is designed to be easily transported between laboratory and test facility. It performs single-point spatially and temporally resolved simultaneous measurements of temperature, species mole fraction of N2, O2, and H2, and two-components of velocity. A mobile laser system can be placed inside or outside the test facility, while a beam receiving and monitoring system is placed near the measurement location. Measurements in a laboratory small-scale Mach 1.6 H2-air combustion-heated supersonic jet were performed to test the capability of the system. Final setup and pretests of a larger scale reacting jet are ongoing at NASA Langley Research Center s Direct Connect Supersonic Combustor Test Facility (DCSCTF).

  4. Proton Fluxes Measured by the PAMELA Experiment from the Minimum to the Maximum Solar Activity for Solar Cycle 24

    Science.gov (United States)

    Martucci, M.; Munini, R.; Boezio, M.; Di Felice, V.; Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Bongi, M.; Bonvicini, V.; Bottai, S.; Bruno, A.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; Castellini, G.; De Santis, C.; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S.; Krutkov, S. Y.; Kvashnin, A. N.; Leonov, A.; Malakhov, V.; Marcelli, L.; Marcelli, N.; Mayorov, A. G.; Menn, W.; Mergè, M.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Osteria, G.; Panico, B.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S. B.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.; Potgieter, M. S.; Raath, J. L.

    2018-02-01

    Precise measurements of the time-dependent intensity of the low-energy (solar activity periods, i.e., from minimum to maximum, are needed to achieve comprehensive understanding of such physical phenomena. The minimum phase between solar cycles 23 and 24 was peculiarly long, extending up to the beginning of 2010 and followed by the maximum phase, reached during early 2014. In this Letter, we present proton differential spectra measured from 2010 January to 2014 February by the PAMELA experiment. For the first time the GCR proton intensity was studied over a wide energy range (0.08–50 GeV) by a single apparatus from a minimum to a maximum period of solar activity. The large statistics allowed the time variation to be investigated on a nearly monthly basis. Data were compared and interpreted in the context of a state-of-the-art three-dimensional model describing the GCRs propagation through the heliosphere.

  5. Noninvasive measurements of cardiac high-energy phosphate metabolites in dilated cardiomyopathy by using 31P spectroscopic chemical shift imaging

    International Nuclear Information System (INIS)

    Hansch, A.; Rzanny, R.; Heyne, J.-P.; Reichenbach, J.R.; Kaiser, W.A.; Leder, U.

    2005-01-01

    Dilated cardiomyopathy (DCM) is accompanied by an impaired cardiac energy metabolism. The aim of this study was to investigate metabolic ratios in patients with DCM compared to controls by using spectroscopic two-dimensional chemical shift imaging (2D-CSI). Twenty volunteers and 15 patients with severe symptoms (left ventricular ejection fraction, LVEF 30%) of DCM were investigated. Cardiac 31 P MR 2D-CSI measurements (voxel size: 40 x 40 x 100 mm 3 ) were performed with a 1.5 T whole-body scanner. Measurement time ranged from 15 min to 30 min. Peak areas and ratios of different metabolites were evaluated, including high-energy phosphates (PCr, ATP), 2,3-diphosphoglycerate (2,3-DPG) and phosphodiesters (PDE). In addition, we evaluated how PCr/ATP ratios correlate with LVEF as an established prognostic factor of heart failure. The PCr/γ-ATP ratio was significantly decreased in patients with moderate and severe DCM and showed a linear correlation with reduced LVEFs. PDE/ATP ratios were significantly increased only in patients with severe DCM as compared to volunteers. Applying 31 P MRS with commonly-available 2D-CSI sequences is a valuable technique to evaluate DCM by determining PCr/ATP ratios noninvasively. In addition to reduced PCr/ATP ratios observed in patients suffering from DCM, significantly-increased PDE/ATP ratios were found in patients with severe DCM. (orig.)

  6. PSYCHE CPMG-HSQMBC: An NMR Spectroscopic Method for Precise and Simple Measurement of Long-Range Heteronuclear Coupling Constants.

    Science.gov (United States)

    Timári, István; Szilágyi, László; Kövér, Katalin E

    2015-09-28

    Among the NMR spectroscopic parameters, long-range heteronuclear coupling constants convey invaluable information on torsion angles relevant to glycosidic linkages of carbohydrates. A broadband homonuclear decoupled PSYCHE CPMG-HSQMBC method for the precise and direct measurement of multiple-bond heteronuclear couplings is presented. The PSYCHE scheme built into the pulse sequence efficiently eliminates unwanted proton-proton splittings from the heteronuclear multiplets so that the desired heteronuclear couplings can be determined simply by measuring frequency differences between peak maxima of pure antiphase doublets. Moreover, PSYCHE CPMG-HSQMBC can provide significant improvement in sensitivity as compared to an earlier Zangger-Sterk-based method. Applications of the proposed pulse sequence are demonstrated for the extraction of (n)J((1)H,(77)Se) and (n)J((1)H,(13)C) values, respectively, in carbohydrates; further extensions can be envisioned in any J-based structural and conformational studies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Use of GNSS derived ionospheric information to detect and measure Solar Flares

    OpenAIRE

    Hernández Pajares, Manuel; García Rigo, Alberto; Aragón Ángel, María Ángeles

    2014-01-01

    The Ionosphere, the partially ionized atmospheric r egion ranging from approximately 60 to +1000 km height, is typically affected by spatial and tempor al variations, driven by Local Time (solar illumina - tion), Latitude (magnetic field and solar illuminat ion) and time (space weather, among seasonal and solar cycle dependence). It can be indirectly studi ed from the dual L-band frequency GNSS measure- ments by assuming the first order ionospheric delay approximation (the higher order ionosp...

  8. Direct Measurement of the 7Be Solar Neutrino Flux with 192 Days of Borexino Data

    International Nuclear Information System (INIS)

    Arpesella, C.; Di Pietro, G.; Monzani, M. E.; Back, H. O.; Hardy, S.; Joyce, M.; Manecki, S.; Raghavan, R. S.; Rountree, D.; Vogelaar, R. B.; Balata, M.; Di Credico, A.; Gazzana, S.; Korga, G.; Laubenstein, M.; Orsini, M.; Papp, L.; Razeto, A.; Tartaglia, R.; Bellini, G.

    2008-01-01

    We report the direct measurement of the 7 Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The interaction rate of the 0.862 MeV 7 Be neutrinos is 49±3 stat ±4 syst counts/(day·100 ton). The hypothesis of no oscillation for 7 Be solar neutrinos is inconsistent with our measurement at the 4σ C.L. Our result is the first direct measurement of the survival probability for solar ν e in the transition region between matter-enhanced and vacuum-driven oscillations. The measurement improves the experimental determination of the flux of 7 Be, pp, and CNO solar ν e , and the limit on the effective neutrino magnetic moment using solar neutrinos

  9. Roof Integrated Solar Absorbers: The Measured Performance of ''Invisible'' Solar Collectors: Preprint

    International Nuclear Information System (INIS)

    Colon, C. J.; Merrigan, T.

    2001-01-01

    The Florida Solar Energy Center (FSEC), with the support of the National Renewable Energy Laboratory, has investigated the thermal performance of solar absorbers that are an integral, yet indistinguishable, part of a building's roof. The first roof-integrated solar absorber (RISA) system was retrofitted into FSEC's Flexible Roof Facility in Cocoa, Florida, in September 1998. This ''proof-of-concept'' system uses the asphalt shingle roof surface and the plywood decking under the shingles as an unglazed solar absorber. Data was gathered for a one-year period on the system performance. In Phase 2, two more RISA prototypes were constructed and submitted for testing. The first used the asphalt shingles on the roof surface with the tubing mounted on the underside of the plywood decking. The second prototype used metal roofing panels over a plywood substrate and placed the polymer tubing between the plywood decking and the metal roofing. This paper takes a first look at the thermal performance results for the ''invisible'' solar absorbers that use the actual roof surface of a building for solar heat collection

  10. Measuring solar induced chlorophyll fluorescence (SIF) in the Amazon rainforest

    Science.gov (United States)

    Kornfeld, A.; Stutz, J.; Berry, J. A.

    2016-12-01

    Measurement of solar induced chlorophyll fluorescence (SIF) has, in our hands, been fraught with missteps and puzzling problems. Here we describe lessons we have learned and the resulting novel system recently installed in the Amazon rainforest near Manaus, Brazil. The system is designed to measure light from 740 - 780 nm, enabling us to compare SIF computed from Fraunhofer lines in an optically transparent band of the atmosphere (745 - 759 nm) with SIF computed using the telluric O2A band (760 - 770 nm). Fraunhofer line analysis requires high optical resolution (better than 0.2 nm) to detect the relatively narrow lines, but we discovered that fiber-optic diffraction-grating spectrometers are sensitive to very small inhomogeneities in the lighting. Errors resulting from this autocorrelated but random noise were similar in magnitude to the SIF signal itself. Optical diffusers reduce this problem, leading to our final design: a sealed cylinder, dubbed Rotaprism, in which a rotatable prism selects whether light from upward- or downward-looking windows enters an axially-placed optical fiber. Cosine-correcting opal glass covering the windows not only solves the noise issue but also makes the measurements correspond to photon flux. Rotaprism also maximizes the amount of light reaching the spectrometer - maximizing the signal:noise ratio - by avoiding the need for lossy optical switches and fiber splitters. Rotaprism is driven by a pneumatic actuator that is controlled by electronic valves attached to a pressurized N2 source. The gas exhausts into the temperature-controlled spectrometer enclosure to help purge the optics. Finally, custom software provides fault-tolerant control and data acquisition, ensuring that measurements continue with little or no intervention at the remote field site despite unreliable power. Analysis of initial data demonstrates the advantage of Fraunhofer line SIF analysis: due to the atmosphere transparency in this band, the results are more

  11. The impact of hydration changes in fresh bio-tissue on THz spectroscopic measurements

    International Nuclear Information System (INIS)

    Png, G M; Ng, B W-H; Mickan, S P; Abbott, D; Choi, J W; Zhang, X-C

    2008-01-01

    We present a study of how residual hydration in fresh rat tissue samples can vastly alter their extracted terahertz (THz) optical properties and influence their health assessment. Fresh (as opposed to preserved) tissue most closely mimics in vivo conditions, but high water content creates many challenges for tissue handling and THz measurement. Our THz measurements of fresh tissue over time highlight the effect of tissue hydration on tissue texture and dimension, the latter directly influencing the accuracy of calculated optical properties. We then introduce lyophilization (freeze drying) as a viable solution for overcoming hydration and freshness problems. Lyophilization removes large amounts of water while retaining sample freshness. In addition, lyophilized tissue samples are easy to handle and their textures and dimensions do not vary over time, allowing for consistent and stable THz measurements. A comparison of lyophilized and fresh tissue shows for the first time that freeze drying may be one way of overcoming tissue hydration issues while preserving tissue cellular structure. Finally, we compare THz measurements from fresh tissue against necrotic tissue to verify freshness over time. Indeed, THz measurements from fresh and necrotic tissues show marked differences

  12. Spectroscopic Measurements of Planar Foil Plasmas Driven by a MA LTD

    Science.gov (United States)

    Patel, Sonal; Yager-Elorriaga, David; Steiner, Adam; Jordan, Nick; Gilgenbach, Ronald; Lau, Y. Y.

    2014-10-01

    Planar foil ablation experiments are being conducted on the Linear Transformer Driver (LTD) at the University of Michigan. The experiment consists of a 400 nm-thick, Al planar foil and a current return post. An optical fiber is placed perpendicular to the magnetic field and linear polarizers are used to isolate the pi and sigma lines. The LTD is charged to +/-70 kV with approximately 400-500 kA passing through the foil. Laser shadowgraphy has previously imaged the plasma and measured anisotropy in the Magneto Rayleigh-Taylor (MRT) instability. Localized magnetic field measurements using Zeeman splitting during the current rise is expected to yield some insight into this anisotropy. Initial experiments use Na D lines of Al foils seeded with sodium to measure Zeeman splitting. Several ion lines are also currently being studied, such as Al III and C IV, to probe the higher temperature core plasma. In planned experiments, several lens-coupled optical fibers will be placed across the foil, and local magnetic field measurements will be taken to measure current division within the plasma. This work was supported by US DoE. S.G. Patel and A.M. Steiner supported by NPSC funded by Sandia. D.A. Yager supported by NSF fellowship Grant DGE 1256260.

  13. The retrieval of profile and chemical information from ground-based UV-visible spectroscopic measurements

    International Nuclear Information System (INIS)

    Schofield, R.; Connor, B.J.; Kreher, K.; Johnston, P.V.; Rodgers, C.D.

    2004-01-01

    An algorithm has been developed to retrieve altitude information at different diurnal stages for trace gas species by combining direct-sun and zenith-sky UV-visible differential slant column density (DSCD) measurements. DSCDs are derived here using differential optical absorption spectroscopy. Combining the complementary zenith-sky measurements (sensitive to the stratosphere) with direct-sun measurements (sensitive to the troposphere) allows this vertical distinction. Trace gas species such as BrO and NO 2 have vertical profiles with strong diurnal dependence. Information about the diurnal variation is simultaneously retrieved with the altitude distribution of the trace gas. The retrieval is a formal optimal estimation profile retrieval, allowing a complete assessment of information content and errors

  14. Upconversion in Nd3+-doped glasses: Microscopic theory and spectroscopic measurements

    International Nuclear Information System (INIS)

    Oliveira, S. L.; Sousa, D. F. de; Andrade, A. A.; Nunes, L. A. O.; Catunda, T.

    2008-01-01

    In this work, we report a systematic investigation of upconversion losses and their effects on fluorescence quantum efficiency and fractional thermal loading in Nd 3+ -doped fluoride glasses. The energy transfer upconversion (γ up ) parameter, which describes upconversion losses, was experimentally determined using different methods: thermal lens (TL) technique and steady state luminescence (SSL) measurements. Additionally, the upconversion parameter was also obtained from energy transfer models and excited state absorption measurements. The results reveal that the microscopic treatment provided by the energy transfer models is similar to the macroscopic ones achieved from the TL and SSL measurements because similar γ up parameters were obtained. Besides, the achieved results also point out the migration-assisted energy transfer according to diffusion-limited regime rather than hopping regime as responsible for the upconversion losses in Nd-doped glasses

  15. On-line nuclear half life and spectroscopic measurements on mass-separated fission product nuclei

    International Nuclear Information System (INIS)

    McDonald, J.; Fogelberg, B.; Baecklin, A.

    1979-01-01

    A description is given of the methods and equipment employed for nuclear spectroscopy studies of short lived fission product nuclei at the OSIRIS ISOL facility in Studsvik, Sweden. Furthermore a table of new nuclear half-lives measured with this equipment is presented. (author)

  16. Spectroscopic measurement of 204Pb isotope shift and 205Pb nuclear spin

    International Nuclear Information System (INIS)

    Schonberger, P.

    1984-01-01

    The isotope shift of 204 Pb and the nuclear spin of 1.4 X 10 7 -y 205 Pb was determined from a high-resolution optical measurement of the 6p 23 P 0 -6p7s 3 P 1 0 283.3-nm resonance line. The value of the shift, relative to 208 Pb is -140.2(8) x 10 -3 cm -1 , the negative sign indicating a shift to lower wave numbers. The precision is 3-4 times greater than that of previous measurements. The spin of 205 Pb I = 5/2 was obtained from the measurement of the relative intensities of its three hyperfine components. This method of absorption spectroscopy determination of ground state nuclear spin is applicable to any stable or long-lived isotope. High resolution optical absorption spectra were obtained with a 25.4 cm diffraction grating in a 9.1 m focal length Czerny-Turner spectrometer. A signal-averaging scanning technique was used to record the spectra. Increased precision in the isotope shift measurement was attained by using separated isotope samples of 204 Pb and 207 Pb

  17. Spectroscopic Measurement of LEAD-204 Isotope Shift and LEAD-205 Nuclear Spin.

    Science.gov (United States)

    Schonberger, Peter

    The isotope shift of ('204)Pb and the nuclear spin of 1.4 x 10('7)-y ('205)Pb was determined from a high -resolution optical measurement of the 6p('2) ('3)P(,o) -6p7s('3)P(,1)('o) 283.3-nm resonance line. The value of the shift, relative to ('208)Pb is -140.2(8) x 10('-3)cm(' -1), the negative sign indicating a shift to lower wave numbers. The precision is 3-4 times greater than that of previous measurements. The spin of ('205)Pb l = 5/2 was obtained from the measurement of the relative intensities of its three hyperfine components. This method of absorption spectroscopy determination of ground state nuclear spin is applicable to any stable or longlived isotope. High resolution optical absorption spectra were obtained with a 25.4cm diffraction grating in a 9.1m focal length Czerny-Turner spectrometer. A signal-averaging scanning technique was used to record the spectra. Increased precision in the isotope shift measurement was attained by using separated isotope samples of ('204)Pb and ('207)Pb. A controlled amount of the later was incorporated in the absorption cell to provide internal calibration by its 6p7s ('3)P(,1)('o) hfs separation. Absorption spectra were recorded for several optical thicknesses of the absorber. A single spin value of increased precision was derived from the entire set of combined data.

  18. Performance Evaluation of Spectroscopic Detectors for LEU Hold-up Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Venkataraman, Ramkumar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nutter, Greg [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McElroy, Robert Dennis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-12-06

    The hold-up measurement of low-enriched uranium materials may require use of alternate detector types relative to the measurement of highly enriched uranium. This is in part due to the difference in process scale (i.e., the components are generally larger for low-enriched uranium systems), but also because the characteristic gamma-ray lines from 235U used for assay of highly enriched uranium will be present at a much reduced intensity (on a per gram of uranium basis) at lower enrichments. Researchers at Oak Ridge National Laboratory examined the performance of several standard detector types, e.g., NaI(Tl), LaBr3(Ce), and HPGe, to select a suitable candidate for measuring and quantifying low-enriched uranium hold-up in process pipes and equipment at the Portsmouth gaseous diffusion plant. Detector characteristics, such as energy resolution (full width at half maximum) and net peak count rates at gamma ray energies spanning a range of 60–1332 keV, were measured for the above-mentioned detector types using the same sources and in the same geometry. Uranium enrichment standards (Certified Reference Material no. 969 and Certified Reference Material no. 146) were measured using each of the detector candidates in the same geometry. The net count rates recorded by each detector at 186 keV and 1,001 keV were plotted as a function of enrichment (atom percentage). Background measurements were made in unshielded and shielded configurations under both ambient and elevated conditions of 238U activity. The highly enriched uranium hold-up measurement campaign at the Portsmouth plant was performed on process equipment that had been cleaned out. Therefore, in most cases, the thickness of the uranium deposits was less than the “infinite thickness” for the 186 keV gamma rays to be completely self-attenuated. Because of this, in addition to measuring the 186 keV gamma, the 1,001 keV gamma ray from 234mPa—a daughter of 238U in secular

  19. LONG-TERM TRENDS IN THE SOLAR WIND PROTON MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Heather A.; McComas, David J. [Southwest Research Institute, San Antonio, TX (United States); DeForest, Craig E. [Southwest Research Institute, Boulder, CO (United States)

    2016-11-20

    We examine the long-term time evolution (1965–2015) of the relationships between solar wind proton temperature ( T {sub p}) and speed ( V {sub p}) and between the proton density ( n {sub p}) and speed using OMNI solar wind observations taken near Earth. We find a long-term decrease in the proton temperature–speed ( T {sub p}– V {sub p}) slope that lasted from 1972 to 2010, but has been trending upward since 2010. Since the solar wind proton density–speed ( n {sub p}– V {sub p}) relationship is not linear like the T {sub p}– V {sub p} relationship, we perform power-law fits for n {sub p}– V {sub p}. The exponent (steepness in the n {sub p}– V {sub p} relationship) is correlated with the solar cycle. This exponent has a stronger correlation with current sheet tilt angle than with sunspot number because the sunspot number maxima vary considerably from cycle to cycle and the tilt angle maxima do not. To understand this finding, we examined the average n {sub p} for different speed ranges, and found that for the slow wind n {sub p} is highly correlated with the sunspot number, with a lag of approximately four years. The fast wind n {sub p} variation was less, but in phase with the cycle. This phase difference may contribute to the n {sub p}– V {sub p} exponent correlation with the solar cycle. These long-term trends are important since empirical formulas based on fits to T {sub p} and V {sub p} data are commonly used to identify interplanetary coronal mass ejections, but these formulas do not include any time dependence. Changes in the solar wind density over a solar cycle will create corresponding changes in the near-Earth space environment and the overall extent of the heliosphere.

  20. Comparison of high-pressure liquid chromatography (HPLC) and Griess reagent-spectroscopic methods for the measurement of nitrate in serum from healthy individuals in the Nordic countries.

    Science.gov (United States)

    Larsen, Tine Lise; Nilsen, Valentina; Andersen, Dag Olav; Francis, George; Rustad, Pål; Mansoor, Mohammad Azam

    2008-12-01

    Bioavailability of NO can be estimated by measuring the concentration of nitrate (NO(3)) in serum. However, the methods used for the measurement NO(3) in plasma or serum show a great degree of variation. Therefore, we compared two analytical methods for the measurement of NO(3) in serum. The concentration of NO(3) in 600 serum samples collected from healthy individuals was determined by the HPLC and by the Griess reagent-spectroscopic method. The concentration of NO(3) in the samples was 29.4+/-16.1 micromol/L and 26.2+/-14.0 micromol/L (mean+/-SD) measured by HPLC and Griess reagent-spectroscopic method respectively (pHPLC method.

  1. Evaluation of conventional and high-performance routine solar radiation measurements for improved solar resource, climatological trends, and radiative modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gueymard, Christian A. [Solar Consulting Services, P.O. Box 392, Colebrook, NH 03576 (United States); Myers, Daryl R. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401-3305 (United States)

    2009-02-15

    The solar renewable energy community depends on radiometric measurements and instrumentation for data to design and monitor solar energy systems, and develop and validate solar radiation models. This contribution evaluates the impact of instrument uncertainties contributing to data inaccuracies and their effect on short-term and long-term measurement series, and on radiation model validation studies. For the latter part, transposition (horizontal-to-tilt) models are used as an example. Confirming previous studies, it is found that a widely used pyranometer strongly underestimates diffuse and global radiation, particularly in winter, unless appropriate corrective measures are taken. Other types of measurement problems are also discussed, such as those involved in the indirect determination of direct or diffuse irradiance, and in shadowband correction methods. The sensitivity of the predictions from transposition models to inaccuracies in input radiation data is demonstrated. Caution is therefore issued to the whole community regarding drawing detailed conclusions about solar radiation data without due attention to the data quality issues only recently identified. (author)

  2. Spectroscopic measurement of ion temperature and ion velocity distributions in the flux-coil generated FRC

    International Nuclear Information System (INIS)

    Gupta, D.; Gota, H.; Hayashi, R.; Kiyashko, V.; Morehouse, M.; Primavera, S.; Bolte, N.; Marsili, P.; Roche, T.; Wessel, F.

    2010-01-01

    One aim of the flux-coil generated field reversed configuration at Tri Alpha Energy (TAE) is to establish the plasma where the ion rotational energy is greater than the ion thermal energy. To verify this, an optical diagnostic was developed to simultaneously measure the Doppler velocity-shift and line-broadening using a 0.75 m, 1800 groves/mm, spectrometer. The output spectrum is magnified and imaged onto a 16-channel photomultiplier tube (PMT) array. The individual PMT outputs are coupled to high-gain, high-frequency, transimpedance amplifiers, providing fast-time response. The Doppler spectroscopy measurements, along with a survey spectrometer and photodiode-light detector, form a suite of diagnostics that provide insights into the time evolution of the plasma-ion distribution and current when accelerated by an azimuthal-electric field.

  3. In-situ gamma spectroscopic measurement of natural waters in Bulgaria

    International Nuclear Information System (INIS)

    Manushev, B.; Mandzhukov, I.; Tsankov, L.; Boshkova, T.; Gurev, V.; Mandzhukova, B.; Kozhukharov, I.; Grozev, G.

    1983-01-01

    In-situ gamma spectrometric measurements are carried out to record differences higher than the errors of measurement in the gamma-field spectra in various basins in Bulgaria - two high mountain lakes, dam and the Black sea. A standard scintillation gamma spectrometer, consisting of a scintillation detector ND-424 type, a channel analyzer NP-424 and a 128 channel Al-128 type analyzer, has been used. The sensitivity of the procedure used is sufficient to detect the transfer of nuclides by dissolution from rocks, forming the bottom and the water-collecting region of the water basin. The advancement of the experimental techniques defines the future use of the procedure. In-situ gamma spectrometric determination may be used in cases of continuous and automated control of the radiation purity of the cooling water in atomic power plants or the water basins located close to such plants and of radioactive contamination of the sea and ocean water

  4. Laser induced breakdown spectroscopy of the uranium including calcium. Time resolved measurement spectroscopic analysis (Contract research)

    International Nuclear Information System (INIS)

    Akaoka, Katsuaki; Maruyama, Youichiro; Oba, Masaki; Miyabe, Masabumi; Otobe, Haruyoshi; Wakaida, Ikuo

    2010-05-01

    For the remote analysis of low DF TRU (Decontamination Factor Transuranic) fuel, Laser Breakdown Spectroscopy (LIBS) was applied to uranium oxide including a small amount of calcium oxide. The characteristics, such as spectrum intensity and plasma excitation temperature, were measured using time-resolved spectroscopy. As a result, in order to obtain the stable intensity of calcium spectrum for the uranium spectrum, it was found out that the optimum observation delay time of spectrum is 4 microseconds or more after laser irradiation. (author)

  5. Solar Radiation Measurement Using Raspberry Pi and Its Modelling Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Priya Selvanathan Shanmuga

    2016-01-01

    Full Text Available The advent of solar energy as the best alternative to traditional energy sources has led to an extensive study on the measurement and prediction of solar radiation. Devices such as pyranometer, pyrrheliometer, global UV radiometer are used for the measurement of solar radiation. The solar radiation measuring instruments available at Innovation Center, MIT Manipal were integrated with a Raspberry Pi to allow remote access to the data through the university Local Area Network. The connections of the data loggers and the Raspberry Pi were enclosed in a plastic box to prevent damage from the rainfall and humidity in Manipal. The solar radiation data was used to validate an Artificial Neural Network model which was developed using various meterological data from 2011-2015.

  6. Applying measured reflection from the ground to simulations of thermal perfromance of solar collectors

    DEFF Research Database (Denmark)

    Dragsted, Janne; Furbo, Simon

    2009-01-01

    representation of the reflection from the ground. In this study a more accurate description of the albedo is obtained based on detailed measurements from a solar hat, installed at ASIAQ’s climate station in Sisimiut, Greenland. The solar hat measures the global radiation on horizontal, the total radiation......Solar radiation on tilted and vertical surfaces in the Arctic is, in large parts of the year, strongly influenced by reflection from snow. In connection with planning and optimization of energy efficient buildings and solar energy systems in the Arctic, it is important to have an accurate...... on vertical surfaces facing north, south, east and west, and radiation reflected from the ground on vertical surfaces facing north, south, east and west. Based on measured data from 2004-2007 the albedo is determined for each month of the year as a function of the difference between the solar azimuth...

  7. Coupling of the solar wind to measures of magnetic activity

    International Nuclear Information System (INIS)

    McPherron, R.L.; Fay, R.A.; Garrity, C.R.; Bargatze, L.F.; Baker, D.N.; Clauer, C.R.; Searls, C.

    1984-01-01

    The technique of linear prediction filtering has been used to generate empirical response functions relating the solar wind electric field to the most frequently used magnetic indices, AL, AU, Dst and ASYM. Two datasets, one from 1967-1968 and one from 1973-1974, provided the information needed to calculate the empirical response functions. These functions have been convolved with solar wind observations obtained during the IMS to predict the indices. These predictions are compared with the observed indices during two, three-day intervals studied extensively by participants in the CDAW-6 workshop. Differences between the observed and predicted indices are discussed in terms of the linear assumption and in terms of physical processes other than direct solar wind-magnetosphere interaction

  8. Measurement of solar neutrinos flux in Russian-American gallium experiment SAGE for half 22-years cycle of solar activity

    International Nuclear Information System (INIS)

    Abdurashitov, D.N.; Veretenkin, E.P.; Vermul, V.M.

    2002-01-01

    The results of measuring the solar neutrino capture on the metallic gallium in the Russian-American experiment SAGE for the period slightly exceeding the half of the 22-year cycle of solar activity, are presented. The results of new measurements since April 1998 are quoted and the analysis of all the measurements, performed by years, months and two-year periods, beginning since 1990 are also presented. Simple analysis of the SAGE results together with the results of other solar neutrino experiments leads to estimating the value of the flux of the pp-neutrinos, reaching the Earth without change in their around, equal to (4.6 ± 1.2) x 10 10 neutrino/(cm 2 s). The value of the flux of the pp-neutrinos, originating in the Sun thermonuclear reactions, is equal to (7.6 ± 2.0) x 10 10 neutrino/(cm 2 s), which agrees well with the standard solar model (5.95 ± 0.6) x 10 10 neutrino/(cm 2 s) [ru

  9. Correlating the vibrational spectra of structurally related molecules: A spectroscopic measure of similarity.

    Science.gov (United States)

    Tao, Yunwen; Zou, Wenli; Cremer, Dieter; Kraka, Elfi

    2018-03-05

    Using catastrophe theory and the concept of a mutation path, an algorithm is developed that leads to the direct correlation of the normal vibrational modes of two structurally related molecules. The mutation path is defined by weighted incremental changes in mass and geometry of the molecules in question, which are successively applied to mutate a molecule into a structurally related molecule and thus continuously converting their normal vibrational spectra from one into the other. Correlation diagrams are generated that accurately relate the normal vibrational modes to each other by utilizing mode-mode overlap criteria and resolving allowed and avoided crossings of vibrational eigenstates. The limitations of normal mode correlation, however, foster the correlation of local vibrational modes, which offer a novel vibrational measure of similarity. It will be shown how this will open new avenues for chemical studies. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  10. Electron spectroscopic evidence of electron correlation in Ni-Pt alloys: comparison with specific heat measurement

    CERN Document Server

    Nahm, T U; Kim, J Y; Oh, S J

    2003-01-01

    We have performed photoemission spectroscopy of Ni-Pt alloys to understand the origin of the discrepancy between the experimental linear coefficient of specific heat gamma and that predicted by band theory. We found that the quasiparticle density of states at the Fermi level deduced from photoemission measurement is in agreement with the experimental value of gamma, if we include the electron correlation effect. It was also found that the Ni 2p core level satellite intensity increases as Ni content is reduced, indicating a strong electron correlation effect which can enhance the quasiparticle effective mass considerably. This supports our conclusion that electron correlation is the most probable reason of disagreement of gamma between experiment and band theory.

  11. Active spectroscopic measurements of the bulk deuterium properties in the DIII-D tokamak (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Grierson, B. A.; Pablant, N. A.; Solomon, W. M. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Burrell, K. H.; Groebner, R. J.; Kaplan, D. H.; Van Zeeland, M. A. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Chrystal, C. [University of California San Diego, La Jolla, California 92093 (United States); Heidbrink, W. W. [University of California Irvine, Irvine, California 92697 (United States); Munoz Burgos, J. M. [Oak Ridge Institute for Science Education, Oak Ridge, Tennessee 37831-0117 (United States)

    2012-10-15

    The neutral-beam induced D{sub {alpha}} emission spectrum contains a wealth of information such as deuterium ion temperature, toroidal rotation, density, beam emission intensity, beam neutral density, and local magnetic field strength magnitude Double-Vertical-Line B Double-Vertical-Line from the Stark-split beam emission spectrum, and fast-ion D{sub {alpha}} emission (FIDA) proportional to the beam-injected fast ion density. A comprehensive spectral fitting routine which accounts for all photoemission processes is employed for the spectral analysis. Interpretation of the measurements to determine physically relevant plasma parameters is assisted by the use of an optimized viewing geometry and forward modeling of the emission spectra using a Monte-Carlo 3D simulation code.

  12. Active spectroscopic measurements of the bulk deuterium properties in the DIII-D tokamak (invited).

    Science.gov (United States)

    Grierson, B A; Burrell, K H; Chrystal, C; Groebner, R J; Kaplan, D H; Heidbrink, W W; Muñoz Burgos, J M; Pablant, N A; Solomon, W M; Van Zeeland, M A

    2012-10-01

    The neutral-beam induced D(α) emission spectrum contains a wealth of information such as deuterium ion temperature, toroidal rotation, density, beam emission intensity, beam neutral density, and local magnetic field strength magnitude |B| from the Stark-split beam emission spectrum, and fast-ion D(α) emission (FIDA) proportional to the beam-injected fast ion density. A comprehensive spectral fitting routine which accounts for all photoemission processes is employed for the spectral analysis. Interpretation of the measurements to determine physically relevant plasma parameters is assisted by the use of an optimized viewing geometry and forward modeling of the emission spectra using a Monte-Carlo 3D simulation code.

  13. Doppler spectroscopic measurements of sheath ion velocities in radio-frequency plasmas

    International Nuclear Information System (INIS)

    Woodcock, B.K.; Busby, J.R.; Freegarde, T.G.; Hancock, G.

    1997-01-01

    We have measured the distributions of N 2 + ion velocity components parallel and perpendicular to the electrode in the sheath of a radio-frequency nitrogen reactive ion etching discharge, using pulsed laser-induced fluorescence. Parallel to the electrode, the ions have throughout a thermal distribution that is found to be consistent with the rotational temperature of 355 K. In the perpendicular direction, we see clearly the acceleration of the ions towards the electrode, and our results agree well with theoretical predictions although an unexpected peak of unaccelerated ions persists. We have also determined the absolute ion concentrations in the sheath, which we have calibrated by analyzing the decay in laser-induced fluorescence in the plasma bulk after discharge extinction. At 20 mTorr, the bulk concentration of 1.0x10 10 cm -3 falls to around 2x10 8 cm -3 at 2 mm from the electrode. copyright 1997 American Institute of Physics

  14. Spectroscopic techniques for measuring ion diode space-charge distributions and ion source properties

    Energy Technology Data Exchange (ETDEWEB)

    Filuk, A B; Bailey, J E; Adams, R G [Sandia Labs., Albuquerque, NM (United States); and others

    1997-12-31

    The authors are using time- and space-resolved visible spectroscopy to measure applied-B ion diode dynamics on the 20 TW Particle Beam Fusion Accelerator II. Doppler broadening of fast Li atoms, as viewed parallel to the anode, is used in a charge-exchange model to obtain the Li{sup +} ion divergence within 100 {mu}m of the anode surface. The characteristic Stark/Zeeman shifts in spectra of alkali neutrals or singly-ionized alkaline-earths are used to measure the strong electric (10{sup 9} V/m) an magnetic ({approx} 6 T) fields in the diode gap. Large Stark shifts within 0.5 mm of the anode indicate the LiF emits with a finite field threshold rather than with Child-Langmuir-type emission, and the small slope in the electric field indicates an unexpected build-up of electrons near the anode. In the diode gap, the authors aim to unfold fields to quantify the time-dependent ion and electron space-charge distributions that determine the ion beam properties. Observed electric field non-uniformities give local beam deflections that can be comparable to the total beam microdivergence. The authors are implementing active laser absorption and laser-induced fluorescence spectroscopy on low-density Na atoms injected into the diode gap prior to the power pulse. The small Doppler broadening in the Na spectra should allow simultaneous electric and magnetic field mapping with improved spatial resolution. (author). 4 figs., 13 refs.

  15. Titration and Spectroscopic Measurements of Poultry Litter pH Buffering Capacity.

    Science.gov (United States)

    Cassity-Duffey, Kate; Cabrera, Miguel; Mowrer, Jake; Kissel, David

    2015-07-01

    The pH value of poultry litter is affected by nitrification, mineralization, and the addition of acidifying chemicals, all acting on the poultry litter pH buffering capacity (pHBC). Increased understanding of poultry litter pHBC will aid in modeling NH volatilization from surface-applied poultry litter as well as estimating rates of alum applications. Our objectives were to (i) determine the pHBC of a wide range of poultry litters; (ii) assess the accuracy of near-infrared reflectance spectroscopy (NIRS) for determining poultry litter pHBC; and (iii) demonstrate the use of poultry litter pHBC to increase the accuracy of alum additions. Litter pHBC was determined by titration and calculated from linear and sigmoidal curves. For the 37 litters measured, linear pHBC ranged from 187 to 537 mmol (pH unit) kg dry litter. The linear and sigmoidal curves provided accurate predictions of pHBC, with most > 0.90. Results from NIRS analysis showed that the linear pHBC expressed on an "as is" water content basis had a NIRS coefficient of calibration (developed using a modified partial least squares procedure) of 0.90 for the 37 poultry litters measured. Using the litter pHBC, an empirical model was derived to determine the amount of alum needed to create a target pH. The model performed well in the range of pH 6.5 to 7.5 (RMSE = 0.07) but underpredicted the amount of alum needed to reach pH litter, which prevented its hydrolysis. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. Trilogy, a planetary geodesy mission concept for measuring the expansion of the solar system

    Science.gov (United States)

    Smith, David E.; Zuber, Maria T.; Mazarico, Erwan; Genova, Antonio; Neumann, Gregory A.; Sun, Xiaoli; Torrence, Mark H.; Mao, Dan-dan

    2018-04-01

    The scale of the solar system is slowly changing, likely increasing as a result of solar mass loss, with additional change possible if there is a secular variation of the gravitational constant, G. The measurement of the change of scale could provide insight into the past and the future of the solar system, and in addition a better understanding of planetary motion and fundamental physics. Estimates for the expansion of the scale of the solar system are of order 1.5 cm year-1 AU-1, which over several years is an observable quantity with present-day laser ranging systems. This estimate suggests that laser measurements between planets could provide an accurate estimate of the solar system expansion rate. We examine distance measurements between three bodies in the inner solar system - Earth's Moon, Mars and Venus - and outline a mission concept for making the measurements. The concept involves placing spacecraft that carry laser ranging transponders in orbit around each body and measuring the distances between the three spacecraft over a period of several years. The analysis of these range measurements would allow the co-estimation of the spacecraft orbit, planetary ephemerides, other geophysical parameters related to the constitution and dynamics of the central bodies, and key geodetic parameters related to the solar system expansion, the Sun, and theoretical physics.

  17. Trilogy, a Planetary Geodesy Mission Concept for Measuring the Expansion of the Solar System.

    Science.gov (United States)

    Smith, David E; Zuber, Maria T; Mazarico, Erwan; Genova, Antonio; Neumann, Gregory A; Sun, Xiaoli; Torrence, Mark H; Mao, Dan-Dan

    2018-04-01

    The scale of the solar system is slowly changing, likely increasing as a result of solar mass loss, with additional change possible if there is a secular variation of the gravitational constant, G . The measurement of the change of scale could provide insight into the past and the future of the solar system, and in addition a better understanding of planetary motion and fundamental physics. Estimates for the expansion of the scale of the solar system are of order 1.5 cm year -1 AU -1 , which over several years is an observable quantity with present-day laser ranging systems. This estimate suggests that laser measurements between planets could provide an accurate estimate of the solar system expansion rate. We examine distance measurements between three bodies in the inner solar system -- Earth's Moon, Mars and Venus -- and outline a mission concept for making the measurements. The concept involves placing spacecraft that carry laser ranging transponders in orbit around each body and measuring the distances between the three spacecraft over a period of several years. The analysis of these range measurements would allow the co-estimation of the spacecraft orbit, planetary ephemerides, other geophysical parameters related to the constitution and dynamics of the central bodies, and key geodetic parameters related to the solar system expansion, the Sun, and theoretical physics.

  18. Ionization Spectroscopic Measurement of nP Rydberg Levels of 87Rb Cold Atoms

    Science.gov (United States)

    Li, Yufan; Zaheeruddin, Syed; Zhao, Dongmei; Ma, Xinwen; Yang, Jie

    2018-05-01

    We created an ultracold plasma via the spontaneous ionization of cold dense Rydberg atoms of 87Rb in a magneto-optical trap (MOT), and measured the nS1/2 (n = 50-80), nP1/2 (n = 16-23), nP3/2 (n = 16-98), and nD5/2 (n = 49-96) Rydberg levels by detecting the electrons in the ultracold plasma. By fitting the energy levels of Rydberg states, the first ionization potential of 33690.950(11) cm-1 and the quantum defects of S, P, and D orbitals were obtained. The absolute transition energies of nS1/2 (n = 66-80), nP1/2 (n = 16-23), nP3/2 (n = 16-98), and nD5/2 (n = 58-96) states of 87Rb, as well as the quantum defects for p1/2 and p3/2 series, are given for the first time.

  19. High-pressure measuring cell for Raman spectroscopic studies of natural gas

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.; Stenby, Erling Halfdan

    2001-01-01

    A system for obtaining Raman spectra of gases at high pressure has been constructed. In order to ensure that a natural gas sample is totally representative, a high-pressure gas-measuring cell has been developed, built up by stainless steel fittings and a sapphire tube. The design and construction...... of this cell are described. A perfect pressure seal has been demonstrated up to 15.0 MPaA (MPa absolute). The cell has been successfully used to obtain Raman spectra of natural gas samples. Some of these spectra are presented and assigned. The most remarkable observation in the spectra is that it is possible...... to detect hydrogen sulfide at concentrations of 1-3 mg H2S/Nm(3). An attempt to make a quantitative analysis of natural gas by the so-called "ratio method" is presented. In addition to this, the relative normalized differential Raman scattering cross sections for ethane and i-butane molecules at 8.0 MPa...

  20. OBSERVING THE FINE STRUCTURE OF LOOPS THROUGH HIGH-RESOLUTION SPECTROSCOPIC OBSERVATIONS OF CORONAL RAIN WITH THE CRISP INSTRUMENT AT THE SWEDISH SOLAR TELESCOPE

    International Nuclear Information System (INIS)

    Antolin, P.; Rouppe van der Voort, L.

    2012-01-01

    Observed in cool chromospheric lines, such as Hα or Ca II H, coronal rain corresponds to cool and dense plasma falling from coronal heights. Considered as a peculiar sporadic phenomenon of active regions, it has not received much attention since its discovery more than 40 years ago. Yet, it has been shown recently that a close relationship exists between this phenomenon and the coronal heating mechanism. Indeed, numerical simulations have shown that this phenomenon is most likely due to a loss of thermal equilibrium ensuing from a heating mechanism acting mostly toward the footpoints of loops. We present here one of the first high-resolution spectroscopic observations of coronal rain, performed with the CRisp Imaging Spectro Polarimeter (CRISP) instrument at the Swedish Solar Telescope. This work constitutes the first attempt to assess the importance of coronal rain in the understanding of the coronal magnetic field in active regions. With the present resolution, coronal rain is observed to literally invade the entire field of view. A large statistical set is obtained in which dynamics (total velocities and accelerations), shapes (lengths and widths), trajectories (angles of fall of the blobs), and thermodynamic properties (temperatures) of the condensations are derived. Specifically, we find that coronal rain is composed of small and dense chromospheric cores with average widths and lengths of ∼310 km and ∼710 km, respectively, average temperatures below 7000 K, displaying a broad distribution of falling speeds with an average of ∼70 km s –1 , and accelerations largely below the effective gravity along loops. Through estimates of the ion-neutral coupling in the blobs we show that coronal rain acts as a tracer of the coronal magnetic field, thus supporting the multi-strand loop scenario, and acts as a probe of the local thermodynamic conditions in loops. We further elucidate its potential in coronal heating. We find that the cooling in neighboring strands

  1. INSTRUMENTATION FOR MEASURING AND TRANSMISSION THE SOLAR RADIATION THROUGH EARTH’S ATMOSPHERE

    Directory of Open Access Journals (Sweden)

    Alexandru Dan Toma

    2013-07-01

    Full Text Available The Sun's energy is distributed over a broad range of the electromagnetic spectrum and Sun behaves approximately like a "blackbody" radiating at a temperature of about 5800 K with maximum output in the green-yellow part of the visible spectrum, around 500 nm. Not all solar radiation reaching the top of the atmosphere reaches Earth's surface due to a various optical phenomena in regard to solar radiation crossing the Earth’s atmosphere. In order to investigate them, there are two general categories of instruments used to measure the transmission of solar radiation through Earth's atmosphere: instruments that measure radiation from the entire sky and instruments that measure only direct solar radiation. Within each of these categories, instruments can be further subdivided into those that measure radiation over a broad range of wavelengths and those that measure only specific wavelengths.

  2. An overview of global solar radiation measurements in Ghardaia area, south Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Gairaa, Kacem; Bakelli, Yahia [Applied Research Unit for Renewables Energies, Ouargla Road, Ghardaia (Algeria)

    2011-07-01

    This paper presents an overview of actual solar radiation data measurements in Ghardaia site (32.360 N, 3.810 W, 450 m above MSL). Global solar radiation and surface temperatures were measured and analyzed for one complete year from 1 January-31December 2005. The data thus recorded are compared with corresponding data of the 22-year average of NASA's surface meteorology and solar energy-model. Hourly, daily and monthly solar radiation was made from five-minute recorded by EKO Pyranometer. The highest measured daily and monthly mean solar radiation was found to be 369 and 326 (W/m2), and the highest five minute averaged solar radiation values up to 1268 (W/m2) were observed in the summer season from May to September, and the yearly average daily energy input was 21.83 (MJ/m2/day). Besides the global solar radiation, the daily and monthly average temperature variations are discussed. The collected data indicate that Ghardaia has a strong potential for solar energy applications.

  3. Cassini-VIMS at Jupiter: Solar occultation measurements using Io

    Science.gov (United States)

    Formisano, V.; D'Aversa, E.; Bellucci, G.; Baines, K.H.; Bibring, J.-P.; Brown, R.H.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe; Chamberlain, M.C.; Hansen, G.; Hibbits, K.; Showalter, M.; Filacchione, G.

    2003-01-01

    We report unusual and somewhat unexpected observations of the jovian satellite Io, showing strong methane absorption bands. These observations were made by the Cassini VIMS experiment during the Jupiter flyby of December/January 2000/2001. The explanation is straightforward: Entering or exiting from Jupiter's shadow during an eclipse, Io is illuminated by solar light which has transited the atmosphere of Jupiter. This light, therefore becomes imprinted with the spectral signature of Jupiter's upper atmosphere, which includes strong atmospheric methane absorption bands. Intercepting solar light refracted by the jovian atmosphere, Io essentially becomes a "miffor" for solar occultation events of Jupiter. The thickness of the layer where refracted solar light is observed is so large (more than 3000 km at Io's orbit), that we can foresee a nearly continuous multi-year period of similar events at Saturn, utilizing the large and bright ring system. During Cassini's 4-year nominal mission, this probing tecnique should reveal information of Saturn's atmosphere over a large range of southern latitudes and times. ?? 2003 Elsevier Inc. All rights reserved.

  4. Overview of on-board measurements during solar storm periods

    Czech Academy of Sciences Publication Activity Database

    Beck, P.; Dyer, C.; Fuller, N.; Hands, A.; Latocha, M.; Rollet, S.; Spurný, František

    2009-01-01

    Roč. 136, č. 4 (2009), s. 297-303 ISSN 0144-8420 R&D Projects: GA ČR GA205/09/0171 Institutional research plan: CEZ:AV0Z10480505 Keywords : solar storm * aircraft crew * cosmic radiation Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.707, year: 2009

  5. Solar wind electron densities from Viking dual-frequency radio measurements

    International Nuclear Information System (INIS)

    Muhleman, D.O.; Anderson, J.D.

    1981-01-01

    Simultaneous phase coherent, two-frequency measurements of the time delay between the Earth station and the Viking spacecraft have been analyzed in terms of the electron density profiles from 4 solar radii (R/sub sun/) to 200 R/sub sun/. The measurements were made during a period of solar activity minimum (1976--1977) and show a strong solar latitude effect. The data were analyzed with both a model independent, direct numerical inversion technique and with model fitting, yielding essentially the same results. It is shown that the solar wind density can be represented by two power laws near the solar equator proportional to r/sup -2.7/ and r/sup -2.04/. However, the more rapidly falling term quickly disappears at moderate latitudes (approx.20 0 ), leaving only the inverse-square behavior

  6. Measurement of Solar Spectra Relating to Photosynthesis and Solar Cells: An Inquiry Lab for Secondary Science

    Science.gov (United States)

    Ruggirello, Rachel M.; Balcerzak, Phyllis; May, Victoria L.; Blankenship, Robert E.

    2012-01-01

    The process of photosynthesis is central to science curriculum at all levels. This article describes an inquiry-based laboratory investigation developed to explore the impact of light quality on photosynthesis and to connect this process to current research on harvesting solar energy, including bioenergy, artificial photosynthesis, and solar…

  7. 31P MR spectroscopic measurement of intracellular pH in normal human hearts

    International Nuclear Information System (INIS)

    Kwon, Jae Hyun; Lee, Hui Joong; Jang, Yong Min

    2002-01-01

    To assess the usefulness of intracellular pH (pHi), calculated by determining the shift of a high-energy metabolite such as inorganic phosphate (Pi) of γ-ATP after performing MRS with ECG-gated two-dimensional 31 P CSI (chemical shift imaging), as a parameter for the overall state of the intracellular milieu. Proto decoupled 31 P CSI was performed on a 1.5-T scanner using a 1 H 31 P dual-tuned surface coil. Cardiac MRS data were obtained from eight normal volunteers aged 24-32 years with no history of heart disease. From the spectra obtained from several regions of the heart, peack position and peak area were estimated. The metabolic ratios of α-, β-, γ-ATP, PCr, Pi, phosphodiester and diphosphoglycerate were calculated, and pHi was estimated from the chemical shift of Pi and γ-ATP resonance. We then compared the data for the anterior myocardium with those previously published. The major phosphorous metabolites identified in these human hearts were as follows: PCr, at -0.1 to +0.1 ppm; three phosphate peaks from ATP, with a chemical shift centered at about -2.7 ppm (γ-ATP), -7.8 ppm (α-ATP), and -16.3 ppm (β-ATP); and phosphodiester (PDE) at 2-3 ppm, inorganic phosphate (Pi) at 4.5-5.4 ppm, and diphosphoglycerate (DPG) at 5.4-6.3 ppm. The PCr/β-ATP ratio was 2.20±0.17 and the PDE/β-ATP ratio, 1.04±0.09 pHi readings were 7.31±0.23 (calculated by the shift of Pi) and 6.81±0.20 (calculated by the shift of γ-ATP). Pi/PCR was 0.539, a ratio higher than that mentioned in previously published reports. The measurement of intracellular metabolism was affected by various kinds of factors. We believe, however, that pHi readings indicate the overall state of the cardiac intracellular milieu. An unexpected pHi readings, seen at MRS, may reflect errors in the MR procedure itself and, or in the analytical method

  8. {sup 31}P MR spectroscopic measurement of intracellular pH in normal human hearts

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jae Hyun; Lee, Hui Joong; Jang, Yong Min [Kyungpook National Univ., Taegu (Korea, Republic of)] [and others

    2002-05-01

    To assess the usefulness of intracellular pH (pHi), calculated by determining the shift of a high-energy metabolite such as inorganic phosphate (Pi) of {gamma}-ATP after performing MRS with ECG-gated two-dimensional {sup 31}P CSI (chemical shift imaging), as a parameter for the overall state of the intracellular milieu. Proto decoupled {sup 31}P CSI was performed on a 1.5-T scanner using a {sup 1}H{sup 31}P dual-tuned surface coil. Cardiac MRS data were obtained from eight normal volunteers aged 24-32 years with no history of heart disease. From the spectra obtained from several regions of the heart, peack position and peak area were estimated. The metabolic ratios of {alpha}-, {beta}-, {gamma}-ATP, PCr, Pi, phosphodiester and diphosphoglycerate were calculated, and pHi was estimated from the chemical shift of Pi and {gamma}-ATP resonance. We then compared the data for the anterior myocardium with those previously published. The major phosphorous metabolites identified in these human hearts were as follows: PCr, at -0.1 to +0.1 ppm; three phosphate peaks from ATP, with a chemical shift centered at about -2.7 ppm ({gamma}-ATP), -7.8 ppm ({alpha}-ATP), and -16.3 ppm ({beta}-ATP); and phosphodiester (PDE) at 2-3 ppm, inorganic phosphate (Pi) at 4.5-5.4 ppm, and diphosphoglycerate (DPG) at 5.4-6.3 ppm. The PCr/{beta}-ATP ratio was 2.20{+-}0.17 and the PDE/{beta}-ATP ratio, 1.04{+-}0.09 pHi readings were 7.31{+-}0.23 (calculated by the shift of Pi) and 6.81{+-}0.20 (calculated by the shift of {gamma}-ATP). Pi/PCR was 0.539, a ratio higher than that mentioned in previously published reports. The measurement of intracellular metabolism was affected by various kinds of factors. We believe, however, that pHi readings indicate the overall state of the cardiac intracellular milieu. An unexpected pHi readings, seen at MRS, may reflect errors in the MR procedure itself and, or in the analytical method.

  9. Lower Ionosphere Sensitivity to Solar X-ray Flares Over a Complete Solar Cycle Evaluated From VLF Signal Measurements

    Science.gov (United States)

    Macotela, Edith L.; Raulin, Jean-Pierre; Manninen, Jyrki; Correia, Emília; Turunen, Tauno; Magalhães, Antonio

    2017-12-01

    The daytime lower ionosphere behaves as a solar X-ray flare detector, which can be monitored using very low frequency (VLF) radio waves that propagate inside the Earth-ionosphere waveguide. In this paper, we infer the lower ionosphere sensitivity variation over a complete solar cycle by using the minimum X-ray fluence (FXmin) necessary to produce a disturbance of the quiescent ionospheric conductivity. FXmin is the photon energy flux integrated over the time interval from the start of a solar X-ray flare to the beginning of the ionospheric disturbance recorded as amplitude deviation of the VLF signal. FXmin is computed for ionospheric disturbances that occurred in the time interval of December-January from 2007 to 2016 (solar cycle 24). The computation of FXmin uses the X-ray flux in the wavelength band below 0.2 nm and the amplitude of VLF signals transmitted from France (HWU), Turkey (TBB), and U.S. (NAA), which were recorded in Brazil, Finland, and Peru. The main result of this study is that the long-term variation of FXmin is correlated with the level of solar activity, having FXmin values in the range (1 - 12) × 10-7 J/m2. Our result suggests that FXmin is anticorrelated with the lower ionosphere sensitivity, confirming that the long-term variation of the ionospheric sensitivity is anticorrelated with the level of solar activity. This result is important to identify the minimum X-ray fluence that an external source of ionization must overcome in order to produce a measurable ionospheric disturbance during daytime.

  10. High-Resolution Infrared Spectroscopic Measurements of Comet 2PlEncke: Unusual Organic Composition and Low Rotational Temperatures

    Science.gov (United States)

    Radeva, Yana L.; Mumma, Michael J.; Villanueva, Geronimo L.; Bonev, Boncho P.; DiSanti, Michael A.; A'Hearn, Michael F.; Dello Russo, Neil

    2013-01-01

    We present high-resolution infrared spectroscopic measurements of the ecliptic comet 2P/Encke, observed on 4-6 Nov. 2003 during its close approach to the Earth, using the Near Infrared Echelle Spectrograph on the Keck II telescope. We present flux-calibrated spectra, production rates, and mixing ratios for H2O, CH3OH, HCN, H2CO, C2H2, C2H6, CH4 and CO. Comet 2P/Encke is a dynamical end-member among comets because of its short period of 3.3 years. Relative to "organics-normal" comets, we determined that 2PlEncke is depleted in HCN, H2CO, C2H2, C2H6, CH4 and CO, but it is enriched in CH3OH. We compared mixing ratios of these organic species measured on separate dates, and we see no evidence of macroscopic chemical heterogeneity in the nucleus of 2P/Encke, however, this conclusion is limited by sparse temporal sampling. The depleted abundances of most measured species suggest that 2P/Encke may have formed closer to the young Sun, before its insertion to the Kuiper belt, compared with "organics-normal" comets - as was previously suggested for other depleted comets (e.g. C/1999 S4 (LINEAR)). We measured very low rotational temperatures of 20 - 30 K for H2O, CH3OH and HCN in the near nucleus region of 2P/Encke, which correlate with one of the lowest cometary gas production rates (approx. 2.6 x 10(exp 27) molecules/s) measured thus far in the infrared. This suggests that we are seeing the effects of more efficient radiative cooling, insufficient collisional excitation, and/or inefficient heating by fast H-atoms (and icy grains) in the observed region of the coma. Its extremely short orbital period, very low gas production rate, and classification as an ecliptic comet, make 2PlEncke an important addition to our growing database, and contribute significantly to the establishment of a chemical taxonomy of comets.

  11. To Measure Probable Physical Changes On The Earth During Total Solar Eclipse Using Geophysical Methods

    International Nuclear Information System (INIS)

    Gocmen, C.

    2007-01-01

    When the total solar eclipse came into question, people connected the eclipse with the earthquake dated 17.08.1999. We thought if any physical parameters change during total solar eclipse on the earth, we could measure this changing and we did the project 'To Measure Probable Physical Changes On The Earth During Total Solar Eclipse Using Geophysical Methods' We did gravity, magnetic and self-potential measurements at Konya and Ankara during total solar eclipse (29, March, 2006) and the day before eclipse and the day after eclipse. The measurements went on three days continuously twenty-four hours at Konya and daytime in Ankara. Bogazici University Kandilli Observatory gave us magnetic values in Istanbul and we compare the values with our magnetic values. Turkish State Meteorological Service sent us temperature and air pressure observations during three days, in Konya and Ankara. We interpreted all of them

  12. Measurement of atmospheric precipitable water using a solar radiometer. [water vapor absorption effects

    Science.gov (United States)

    Pitts, D. E.; Dillinger, A. E.; Mcallum, W. E.

    1974-01-01

    A technique is described and tested that allows the determination of atmospheric precipitable water from two measurements of solar intensity: one in a water-vapor absorption band and another in a nearby spectral region unaffected by water vapor.

  13. Diagnostics of the Solar Wind and Global Heliosphere with Lyman-α Emission Measurements

    Science.gov (United States)

    Provornikova, E. P.; Izmodenov, V. V.; Laming, J. M.; Strachan, L.; Wood, B. E.; Katushkina, O. A.; Ko, Y.-K.; Tun Beltran, S.; Chakrabarti, S.

    2018-02-01

    We propose to develop an instrument measuring full sky intensity maps and spectra of interplanetary Lyman-α emission to reveal the global solar wind variability and the nature of the heliosphere and the local interstellar medium.

  14. Outdoor solar UVA dose assessment with EBT2 radiochromic film using spectrophotometer and densitometer measurements

    International Nuclear Information System (INIS)

    Abukassem, I.; Bero, M.A.

    2015-01-01

    Direct measurements of solar ultraviolet radiations (UVRs) have an important role in the protection of humans against UVR hazard. This work presents simple technique based on the application of EBT2 GAFCHROMIC R film for direct solar UVA dose assessment. It demonstrates the effects of different parts of the solar spectrum (UVB, visible and infrared) on performed UVA field measurements and presents the measurement uncertainty budget. The gradient of sunlight exposure level permitted the authors to establish the mathematical relationships between the measured solar UVA dose and two measured quantities: the first was the changes in spectral absorbance at the wavelength 633 nm (A 633 ) and the second was the optical density (OD). The established standard relations were also applied to calculate the solar UVA dose variations during the whole day; 15 min of exposure each hour between 8:00 and 17:00 was recorded. Results show that both applied experimental methods, spectrophotometer absorbance and densitometer OD, deliver comparable figures for EBT2 solar UVA dose assessment with relative uncertainty of 11 % for spectral absorbance measurements and 15 % for OD measurements. (authors)

  15. Outdoor solar UVA dose assessment with EBT2 radiochromic film using spectrophotometer and densitometer measurements.

    Science.gov (United States)

    Abukassem, I; Bero, M A

    2015-04-01

    Direct measurements of solar ultraviolet radiations (UVRs) have an important role in the protection of humans against UVR hazard. This work presents simple technique based on the application of EBT2 GAFCHROMIC(®) film for direct solar UVA dose assessment. It demonstrates the effects of different parts of the solar spectrum (UVB, visible and infrared) on performed UVA field measurements and presents the measurement uncertainty budget. The gradient of sunlight exposure level permitted the authors to establish the mathematical relationships between the measured solar UVA dose and two measured quantities: the first was the changes in spectral absorbance at the wavelength 633 nm (A633) and the second was the optical density (OD). The established standard relations were also applied to calculate the solar UVA dose variations during the whole day; 15 min of exposure each hour between 8:00 and 17:00 was recorded. Results show that both applied experimental methods, spectrophotometer absorbance and densitometer OD, deliver comparable figures for EBT2 solar UVA dose assessment with relative uncertainty of 11% for spectral absorbance measurements and 15% for OD measurements. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Direct Heat-Flux Measurement System (MDF) for Solar central Receiver Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ballestrin, J.

    2001-07-01

    A direct flux measurement system, MDF, has been designed, constructed and mounted on top of the SSPS-CRS tower at the Plataforma Solar de Almeria (PSA) in addition to an indirect flux measurement system based on a CCD camera. It's one of the main future objectives to compare systematically both measurements of the concentrated solar power, increasing in this way the confidence in the estimate of this quantity. Today everything is prepared to perform the direct flux measurement on the aperture of solar receivers: calorimeter array, data acquisition system and software. the geometry of the receiver determines the operation and analysis procedures to obtain the indecent power onto the defined area. The study of previous experiences with direct flux measurement systems ha been useful to define a new simpler and more accurate system. A description of each component of the MDF system is included, focusing on the heat-flux sensors or calorimeters, which enables these measurements to be done in a few seconds without water-cooling. The incident solar power and the spatial flux distribution on the aperture of the volumetric receiver Hitrec II are supplied by the above-mentioned MDF system. The first results obtained during the evaluation of this solar receiver are presented including a sunrise-sunset test. All these measurements have been concentrated in one coefficient that describes the global behavior of the Solar Power Plant. (Author) 18 refs.

  17. Note: Photoluminescence measurement system for multi-junction solar cells.

    Science.gov (United States)

    Trespidi, F; Malchiodi, A; Farina, F

    2017-05-01

    We describe a photoluminescence spectroscopy system developed for studying phenomena of optical coupling in multiple-junction solar cells and processed/unprocessed wafers, under the high solar concentration levels typical of HCPV (High Concentration PhotoVoltaic) systems. The instrument operates at room temperature over two spectral ranges: 475 nm-1100 nm and 950 nm-1650 nm. Power densities exceeding 10 000 suns can be obtained on the sample. The system can host up to four compact focusable solid state laser sources, presently only three are mounted and operated at 450 nm, 520 nm, and 785 nm; they provide overlapped beams on the sample surface and can shine simultaneously the sample to study possible mutual interaction between the different junctions.

  18. Combining parallel detection of proton echo planar spectroscopic imaging (PEPSI) measurements with a data-consistency constraint improves SNR.

    Science.gov (United States)

    Tsai, Shang-Yueh; Hsu, Yi-Cheng; Chu, Ying-Hua; Kuo, Wen-Jui; Lin, Fa-Hsuan

    2015-12-01

    One major challenge of MRSI is the poor signal-to-noise ratio (SNR), which can be improved by using a surface coil array. Here we propose to exploit the spatial sensitivity of different channels of a coil array to enforce the k-space data consistency (DC) in order to suppress noise and consequently to improve MRSI SNR. MRSI data were collected using a proton echo planar spectroscopic imaging (PEPSI) sequence at 3 T using a 32-channel coil array and were averaged with one, two and eight measurements (avg-1, avg-2 and avg-8). The DC constraint was applied using a regularization parameter λ of 1, 2, 3, 5 or 10. Metabolite concentrations were quantified using LCModel. Our results show that the suppression of noise by applying the DC constraint to PEPSI reconstruction yields up to 32% and 27% SNR gain for avg-1 and avg-2 data with λ = 5, respectively. According to the reported Cramer-Rao lower bounds, the improvement in metabolic fitting was significant (p < 0.01) when the DC constraint was applied with λ ≥ 2. Using the DC constraint with λ = 3 or 5 can minimize both root-mean-square errors and spatial variation for all subjects using the avg-8 data set as reference values. Our results suggest that MRSI reconstructed with a DC constraint can save around 70% of scanning time to obtain images and spectra with similar SNRs using λ = 5. Copyright © 2015 John Wiley & Sons, Ltd.

  19. Recent measurements of the flux excess from solar faculae and the implication for the solar oblateness

    International Nuclear Information System (INIS)

    Chapman, G.A.

    1975-01-01

    Direct observation of the excess brightness from photospheric faculae are presented. This excess brightness is, at times, large enough to produce an apparent oblateness that exceeds that reported by Dicke and Goldenberg. These results support the Chapman-Ingersoll facular explanation for the excess solar oblateness and support the findings of Hill et al. by offering a possible source for their excess equatorial brightness which, they showed, can produce an apparent, nongeometrical oblateness

  20. Review of Image Quality Measures for Solar Imaging

    Science.gov (United States)

    Popowicz, Adam; Radlak, Krystian; Bernacki, Krzysztof; Orlov, Valeri

    2017-12-01

    Observations of the solar photosphere from the ground encounter significant problems caused by Earth's turbulent atmosphere. Before image reconstruction techniques can be applied, the frames obtained in the most favorable atmospheric conditions (the so-called lucky frames) have to be carefully selected. However, estimating the quality of images containing complex photospheric structures is not a trivial task, and the standard routines applied in nighttime lucky imaging observations are not applicable. In this paper we evaluate 36 methods dedicated to the assessment of image quality, which were presented in the literature over the past 40 years. We compare their effectiveness on simulated solar observations of both active regions and granulation patches, using reference data obtained by the Solar Optical Telescope on the Hinode satellite. To create images that are affected by a known degree of atmospheric degradation, we employed the random wave vector method, which faithfully models all the seeing characteristics. The results provide useful information about the method performances, depending on the average seeing conditions expressed by the ratio of the telescope's aperture to the Fried parameter, D/r0. The comparison identifies three methods for consideration by observers: Helmli and Scherer's mean, the median filter gradient similarity, and the discrete cosine transform energy ratio. While the first method requires less computational effort and can be used effectively in virtually any atmospheric conditions, the second method shows its superiority at good seeing (D/r0<4). The third method should mainly be considered for the post-processing of strongly blurred images.

  1. Diagnostics of the solar corona from comparison between Faraday rotation measurements and magnetohydrodynamic simulations

    International Nuclear Information System (INIS)

    Le Chat, G.; Cohen, O.; Kasper, J. C.; Spangler, S. R.

    2014-01-01

    Polarized natural radio sources passing behind the Sun experience Faraday rotation as a consequence of the electron density and magnetic field strength in coronal plasma. Since Faraday rotation is proportional to the product of the density and the component of the magnetic field along the line of sight of the observer, a model is required to interpret the observations and infer coronal structures. Faraday rotation observations have been compared with relatively ad hoc models of the corona. Here for the first time we compare these observations with magnetohydrodynamic (MHD) models of the solar corona driven by measurements of the photospheric magnetic field. We use observations made with the NRAO Very Large Array of 34 polarized radio sources occulted by the solar corona between 5 and 14 solar radii. The measurements were made during 1997 May, and 2005 March and April. We compare the observed Faraday rotation values with values extracted from MHD steady-state simulations of the solar corona. We find that (1) using a synoptic map of the solar magnetic field just one Carrington rotation off produces poorer agreements, meaning that the outer corona changes in the course of one month, even in solar minimum; (2) global MHD models of the solar corona driven by photospheric magnetic field measurements are generally able to reproduce Faraday rotation observations; and (3) some sources show significant disagreement between the model and the observations, which appears to be a function of the proximity of the line of sight to the large-scale heliospheric current sheet.

  2. Solar Cycle variations in Earth's open flux content measured by the SuperDARN radar network

    Science.gov (United States)

    Imber, S. M.; Milan, S. E.; Lester, M.

    2013-09-01

    We present a long term study, from 1996 - 2012, of the latitude of the Heppner-Maynard Boundary (HMB) determined using the northern hemisphere SuperDARN radars. The HMB represents the equatorward extent of ionospheric convection and is here used as a proxy for the amount of open flux in the polar cap. The mean HMB latitude (measured at midnight) is found to be at 64 degrees during the entire period, with secondary peaks at lower latitudes during the solar maximum of 2003, and at higher latitudes during the recent extreme solar minimum of 2008-2011. We associate these large scale statistical variations in open flux content with solar cycle variations in the solar wind parameters leading to changes in the intensity of the coupling between the solar wind and the magnetosphere.

  3. Data analysis of solar potential in northern Bulgaria obtained by measurements with tall meteorological masts

    International Nuclear Information System (INIS)

    Terziev, A.; Genovski, I.; Petrov, P.; Valchev, V.

    2010-01-01

    Energy from the sun as a renewable energy source could be used for producing not only heat energy but also electricity. The maximum utilization of this type energy requires very good knowledge of the solar radiation for an exact geographical location. Determination of the solar intensity is carried out with special devices called pyranometers. This work considers solar potential data analysis based on data collected from meteorological masts installed in Northern Bulgaria. Comparison between the data from on-site measurements and some long-term data sources well known in literature is also considered. The possibility of studying the interpolation between the points where measurements are carried out in order to obtain solar radiation intensity Filed for the area limited by the points of measurement is also reviewed. Based on correlation analysis results the estimated energy production within the studied area has been calculated. (authors)

  4. A comparison of solar irradiances measured by SBUV, SME, and rockets

    Science.gov (United States)

    Schlesinger, Barry M.; Heath, Donald F.

    1988-01-01

    In this paper, Solar Backscatter Ultraviolet (SBUV) measurements of solar irradiance and predictions from the Mg 280-nm index are compared with each other and with coincident Solar Mesosphere Explorer (SME) and rocket measurements. The SBUV irradiances show a systematic decrease with time not seen in the rocket measurements; a correction for this decrease is introduced. The scatter and overall structure in the SME spectra is 3-5 percent, of the order of or larger than most of the changes predicted by the Mg index. The corrected SBUV ratio and the Mg index prediction for it agree to within 1 percent. Such agreement supports a common origin for variations between solar maximum and minimum and those for individual rotations: the degree to which active regions cover the visible hemisphere of the sun.

  5. Introduction to meteorological measurements and data handling for solar energy applications. Task IV. Development of an isolation handbook and instrument package

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-01

    The following are covered: the Sun and its radiation, solar radiation and atmospheric interaction, solar radiation measurement methods, spectral irradiance measurements of natural sources, the measurement of infrared radiation, the measurement of circumsolar radiation, some empirical properties of solar radiation and related parameters, duration of sunshine, and meteorological variables related to solar energy. Included in appendices are manufacturers and distributors of solar radiation measuring instruments and an approximate method for quality control of solar radiation instruments. (MHR)

  6. Optical constants of CH3NH3PbBr3 perovskite thin films measured by spectroscopic ellipsometry

    KAUST Repository

    Alias, Mohd Sharizal; Dursun, Ibrahim; Saidaminov, Makhsud I.; Diallo, Elhadj Marwane; Mishra, Pawan; Ng, Tien Khee; Bakr, Osman; Ooi, Boon S.

    2016-01-01

    function) of CH3NH3PbBr3 perovskite thin films using spectroscopic ellipsometry. Due to the existence of voids, the refractive index of the thin films is around 8% less than the single crystals counterpart. The energy bandgap is around 2.309 eV as obtained

  7. Sky brightness and color measurements during the 21 August 2017 total solar eclipse.

    Science.gov (United States)

    Bruns, Donald G; Bruns, Ronald D

    2018-06-01

    The sky brightness was measured during the partial phases and during totality of the 21 August 2017 total solar eclipse. A tracking CCD camera with color filters and a wide-angle lens allowed measurements across a wide field of view, recording images every 10 s. The partially and totally eclipsed Sun was kept behind an occulting disk attached to the camera, allowing direct brightness measurements from 1.5° to 38° from the Sun. During the partial phases, the sky brightness as a function of time closely followed the integrated intensity of the unobscured fraction of the solar disk. A redder sky was measured close to the Sun just before totality, caused by the redder color of the exposed solar limb. During totality, a bluer sky was measured, dimmer than the normal sky by a factor of 10,000. Suggestions for enhanced measurements at future eclipses are offered.

  8. Photometric measurements of solar irradiance variations due to sunspots

    International Nuclear Information System (INIS)

    Chapman, G.A.; Herzog, A.D.; Laico, D.E.; Lawrence, J.K.; Templer, M.S.

    1989-01-01

    A photometric telescope constructed to obtain photometric sunspot areas and deficits on a daily basis is described. Data from this Cartesian full disk telescope (CFDT) are analyzed with attention given to the period between June 4 and June 17, 1985 because of the availability of overlapping sunspot area and irradiance deficit data from high-resolution digital spectroheliograms made with the San Fernando Observatory 28 cm vacuum solar telescope and spectroheliograph. The CFDT sunspot deficits suggest a substantial irradiance contribution from faculae and active region plage. 23 refs

  9. Solar UV exposures measured simultaneously to all arbitrarily oriented leaves on a plant.

    Science.gov (United States)

    Parisi, Alfio V; Schouten, Peter; Downs, Nathan J; Turner, Joanna

    2010-05-03

    The possible ramifications of climate change include the influence it has upon the amount of cloud cover in the atmosphere. Clouds cause significant variation in the solar UV radiation reaching the earth's surface and in turn the amount incident on ecosystems. The consequences of changes in solar UV radiation delivered to ecosystems due to climate change may be significant and should be investigated. Plants are an integral part of the world wide ecological balance, and research has shown they are affected by variations in solar UV radiation. Therefore research into the influence of solar UV radiation on plants is of particular significance. However, this requires a means of obtaining detailed information on the solar UV radiation received by plants. This research describes a newly developed dosimetric technique employed to gather information on solar UV radiation incident to the leaves of plants in combination with the measurement of spectral irradiances in order to provide an accurate method of collecting detailed information on the solar UV radiation affecting the canopy and lower leaf layers of individual plants. Variations in the measurements take into account the inclination and orientation of each leaf investigated, as well as the influence of shading by other leaves in the plant canopy. Copyright 2010 Elsevier B.V. All rights reserved.

  10. Measurement of the total solar energy transmittance (g-value) for conventional glazings

    DEFF Research Database (Denmark)

    Duer, Karsten

    1998-01-01

    Three different glazings have been investigated in the Danish experimental setup METSET. (A device for calorimetric measurement of total solar energy transmittance - g-value).The purpose of the measurements is to increase the confidence in the calorimetric measurements. This is done by comparison...

  11. Qualification and recovering of solar radiation data measured at Florianopolis, state of Santa Catarina, Brazil; Qualificacao e recuperacao de dados de radiacao solar medidos em Florianopolis - Santa Catarina

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Samuel L. de; Colle, Sergio; Almeida, Anand P.; Mantelli Neto, Sylvio Luiz [Santa Catarina Univ., Florianopolis (Brazil). Lab. de Energia Solar]. E-mail: samuel@emc.ufsc.br; colle@emc.ufsc.br; anand@labsolar.ufsc.br; sylvio@labsolar.ufsc.br

    2000-07-01

    The incident solar radiation is one of the most important inputs for simulation programs of solar thermal systems and of thermal behavior of buildings. Actually, these kind of data are well known for countries where long-term measurements of incident solar radiation are available. This fact allows the use of statistical procedures to generate typical meteorological years for simulation. In Brazil, solar radiation data are measured in sites spread all over the country by individual efforts. These data are usually measured only during short periods of time, does not have any standardization, and also are not easy to access. The present work describes the steps of qualification and data-filling used to handle the raw data measured in a specific location. The present data were measured in the radiometric station of the Solar Energy Laboratory (Federal University of Santa Catarina) in Florianopolis, for the period of 1990 to 1999. (author)

  12. Errors in short circuit measurements due to spectral mismatch between sunlight and solar simulators

    Science.gov (United States)

    Curtis, H. B.

    1976-01-01

    Errors in short circuit current measurement were calculated for a variety of spectral mismatch conditions. The differences in spectral irradiance between terrestrial sunlight and three types of solar simulator were studied, as well as the differences in spectral response between three types of reference solar cells and various test cells. The simulators considered were a short arc xenon lamp AMO sunlight simulator, an ordinary quartz halogen lamp, and an ELH-type quartz halogen lamp. Three types of solar cells studied were a silicon cell, a cadmium sulfide cell and a gallium arsenide cell.

  13. Measurement of the North-South asymmetry in the solar proton albedo neutron flux

    International Nuclear Information System (INIS)

    Ifedili, S.O.

    1979-01-01

    The solar proton albedo neutron flux in the range 10 -2 --10 7 eV measured by a neutron detector on board the Ogo 6 satellite was examined for north-south asymmetry. For the solar proton event of December 19, 1969, the S/N ratio of the solar proton albedo neutron rate at geomagnetic latitude lambda>70 0 was 1.61 +- 0.27 during the event, while for the November 2, 1969, event at 40 0 0 and altitudes ranging from 700 km to 800 km the solar proton albedo neutron rate was 0.40 +- 0.10 count/s in the north and 0.00 +- 0.10 count/s in the south. During the solar proton event of December 18, 1969, the N/S ratio of the solar proton albedo neutron rate at lambda>70 0 was 1.00 +- 0.26. The results are consistent with the expected N-S asymmetry in the solar proton flux. An interplanetary proton anisotropy with the interplanetary magnetic field polarity away from the sun corresponded to larger fluxes of solar proton albedo neutrons at the north polar cap than at the south, while an interplanetary proton anisotropy with the interplanetary magnetic field polarity toward the sun corresponded to larger fluxes of solar proton albedo neutrons at the south polar cap than at the north. This evidence favors the direct access of solar protons to the earth's polar caps via the merged interplanetary and geomagnetic field lines

  14. Solar radiation measurements at the network of six sites in the UK, January - December 2001

    Energy Technology Data Exchange (ETDEWEB)

    Driscoll, C.M.H.; Campbell, J.I.; Pearson, A.J.; Grainger, K.J.L.; Dean, S.F.; Clark, I.E

    2002-04-01

    A summary of the results from January to December 2001 of a survey of solar radiation levels at the UK network of six solar radiation measurement sites is presented. The network consists of three NRPB sites at Chilton, Leeds and (monitoring since 1988) and three Meteorological Office stations at Camborne, Kinloss and Lerwick (monitoring since 1993). Visible (400-770 nm), ultraviolet UVA radiation (320-400 nm) and erythemally weighted ultraviolet radiation UVR{sub eff} (280-400 nm) have been measured simultaneously using a three detector measurement system. Results are compared with calculated irradiances of ultraviolet radiation and published illuminance data, and with data for the measurement period from 1988 to 2000. Yearly reports have been produced for selected sites, giving the daily solar index (which is a measure of the sunburn potential for sensitive skin types) throughout the year. (author)

  15. Solar radiation measurements at the network of six sites in the UK, January - December 2001

    International Nuclear Information System (INIS)

    Driscoll, C.M.H.; Campbell, J.I.; Pearson, A.J.; Grainger, K.J.L.; Dean, S.F.; Clark, I.E.

    2002-01-01

    A summary of the results from January to December 2001 of a survey of solar radiation levels at the UK network of six solar radiation measurement sites is presented. The network consists of three NRPB sites at Chilton, Leeds and (monitoring since 1988) and three Meteorological Office stations at Camborne, Kinloss and Lerwick (monitoring since 1993). Visible (400-770 nm), ultraviolet UVA radiation (320-400 nm) and erythemally weighted ultraviolet radiation UVR eff (280-400 nm) have been measured simultaneously using a three detector measurement system. Results are compared with calculated irradiances of ultraviolet radiation and published illuminance data, and with data for the measurement period from 1988 to 2000. Yearly reports have been produced for selected sites, giving the daily solar index (which is a measure of the sunburn potential for sensitive skin types) throughout the year. (author)

  16. Early solar physics

    CERN Document Server

    Meadows, A J

    1970-01-01

    Early Solar Physics reviews developments in solar physics, particularly the advent of solar spectroscopy and the discovery of relationships between the various layers of the solar atmosphere and between the different forms of solar activity. Topics covered include solar observations during 1843; chemical analysis of the solar atmosphere; the spectrum of a solar prominence; and the solar eclipse of December 12, 1871. Spectroscopic observations of the sun are also presented. This book is comprised of 30 chapters and begins with an overview of ideas about the sun in the mid-nineteenth century, fo

  17. Yearly thermal performances of solar heating plants in Denmark – Measured and calculated

    DEFF Research Database (Denmark)

    Furbo, Simon; Dragsted, Janne; Perers, Bengt

    2018-01-01

    The thermal performance of solar collector fields depends mainly on the mean solar collector fluid temperature of the collector field and on the solar radiation. For Danish solar collector fields for district heating the measured yearly thermal performances per collector area varied in the period...... 2012–2016 between 313 kWh/m2 and 577 kWh/m2, with averages between 411 kWh/m2 and 463 kWh/m2. The percentage difference between the highest and lowest measured yearly thermal performance is about 84%. Calculated yearly thermal performances of typically designed large solar collector fields at six...... different locations in Denmark with measured weather data for the years 2002–2010 vary between 405 kWh/m2 collector and 566 kWh/m2 collector, if a mean solar collector fluid temperature of 60 °C is assumed. This corresponds to a percentage difference between the highest and lowest calculated yearly thermal...

  18. Measuring Broadband IR Irradiance in the Direct Solar Beam and Recent Developments

    Energy Technology Data Exchange (ETDEWEB)

    Reda, Ibrahim; Andreas, Afshin; Dooraghi, Mike; Habte, Aron; Sengupta, Manajit; Kutchenreiter, Mark

    2016-12-14

    Solar and atmospheric science radiometers such as pyranometers, pyrheliometers, and photovoltaic cells are calibrated with traceability to a consensus reference which is maintained by Absolute Cavity Radiometers (ACRs). An ACR is an open cavity with no window, developed to measure the extended broadband spectrum of the terrestrial direct solar beam irradiance that extends beyond the ultraviolet and infrared bands; i.e. below 0.2 um and above 50 um, respectively. On the other hand, the pyranometers and pyrheliometers were developed to measure broadband shortwave irradiance from approximately 0.3 um to 3 um, while the present photovoltaic cells are limited to the spectral range of approximately 0.3 um to 1 um. The broadband mismatch of ACR versus such radiometers causes discrepancy in radiometers' calibration methods that has not been discussed or addressed in the solar and atmospheric science literature. Pyrgeometers, which measure the atmospheric longwave irradiance, are also used for solar and atmospheric science applications and calibrated with traceability to a consensus reference, yet they are calibrated during nighttime only, because no consensus reference has been established for the daytime longwave irradiance. This poster describes a method to measure the broadband longwave irradiance in the terrestrial direct solar beam from 3 um to 50 um, as a first step that might be used to help develop calibration methods to address the mismatch between broadband ACR and shortwave radiometers, and the lack of a daytime reference for pyrgeometers. The described method is used to measure the irradiance from sunrise to sunset; the irradiance varied from approximately 1 Wm-2 to 16 Wm-2 with an estimated uncertainty of 1.5 Wm-2, for a solar zenith angle range from 80 degrees to 16 degrees, respectively. Recent development shows that there is greater than 1.1 percent bias in measuring shortwave solar irradiance.

  19. The I-V Measurement System for Solar Cells Based on MCU

    International Nuclear Information System (INIS)

    Chen Fengxiang; Ai Yu; Wang Jiafu; Wang Lisheng

    2011-01-01

    In this paper, an I-V measurement system for solar cells based on Single-chip Microcomputer (MCU) is presented. According to the test principles of solar cells, this measurement system mainly comprises of two parts-data collecting, data processing and displaying. The MCU mainly used as to acquire data, then the collecting results is sent to the computer by serial port. The I-V measurement results of our test system are shown in the human-computer interaction interface based on our hardware circuit. By comparing the test results of our I-V tester and the results of other commercial I-V tester, we found errors for most parameters are less than 5%, which shows our I-V test result is reliable. Because the MCU can be applied in many fields, this I-V measurement system offers a simple prototype for portable I-V tester for solar cells.

  20. The I-V Measurement System for Solar Cells Based on MCU

    Energy Technology Data Exchange (ETDEWEB)

    Chen Fengxiang; Ai Yu; Wang Jiafu; Wang Lisheng, E-mail: phonixchen79@yahoo.com.cn [Department of physics science and technology, Wuhan University of Technology, Wuhan city, Hubei Province, 430070 (China)

    2011-02-01

    In this paper, an I-V measurement system for solar cells based on Single-chip Microcomputer (MCU) is presented. According to the test principles of solar cells, this measurement system mainly comprises of two parts-data collecting, data processing and displaying. The MCU mainly used as to acquire data, then the collecting results is sent to the computer by serial port. The I-V measurement results of our test system are shown in the human-computer interaction interface based on our hardware circuit. By comparing the test results of our I-V tester and the results of other commercial I-V tester, we found errors for most parameters are less than 5%, which shows our I-V test result is reliable. Because the MCU can be applied in many fields, this I-V measurement system offers a simple prototype for portable I-V tester for solar cells.

  1. Summary report on the Japan-US workshop on the assessment of spectroscopic data for temperature and density measurements

    International Nuclear Information System (INIS)

    Wiese, W.L.; Fujita, J.

    1988-03-01

    This workshop was held as a part of the US-Japan Cooperative Fusion Program 1986 at the Institute of Plasma Physics, Nagoya University, on March 18 - 20, 1987. Talks were carried out on the following plasma diagnostic subjects, giving special consideration to the situation of spectroscopic data and the needs, availability and adequacy of the data: x-ray spectroscopy, VUV and visible region spectroscopy, plasma edge spectroscopy, polarization spectroscopy, charge exchange spectroscopy, excitation rate data, and spectral radiometry and spectroscopic data tables. The program of the workshop and the abstracts of the talks are given in the first part of this summary report. On the last day of the workshop, small groups were formed, which deliberated on the situation of spectroscopic data in the various diagnostic areas, and especially focused on the further needs of the data. The summary of the findings and recommendation are given in the second part. The workshop was attended by five US and 25 Japanese scientists, and greatly benefitted from the active participation of three quests. (Kako, I.)

  2. Janus: Graphical Software for Analyzing In-Situ Measurements of Solar-Wind Ions

    Science.gov (United States)

    Maruca, B.; Stevens, M. L.; Kasper, J. C.; Korreck, K. E.

    2016-12-01

    In-situ observations of solar-wind ions provide tremendous insights into the physics of space plasmas. Instrument on spacecraft measure distributions of ion energies, which can be processed into scientifically useful data (e.g., values for ion densities and temperatures). This analysis requires a strong, technical understanding of the instrument, so it has traditionally been carried out by the instrument teams using automated software that they had developed for that purpose. The automated routines are optimized for typical solar-wind conditions, so they can fail to capture the complex (and scientifically interesting) microphysics of transient solar-wind - such as coronal mass ejections (CME's) and co-rotating interaction regions (CIR's) - which are often better analyzed manually.This presentation reports on the ongoing development of Janus, a new software package for processing in-situ measurement of solar-wind ions. Janus will provide user with an easy-to-use graphical user interface (GUI) for carrying out highly customized analyses. Transparent to the user, Janus will automatically handle the most technical tasks (e.g., the retrieval and calibration of measurements). For the first time, users with only limited knowledge about the instruments (e.g., non-instrumentalists and students) will be able to easily process measurements of solar-wind ions. Version 1 of Janus focuses specifically on such measurements from the Wind spacecraft's Faraday Cups and is slated for public release in time for this presentation.

  3. Comparisons of Measurements and Modeling of Solar Eclipse Effects on VLF Transmissions

    Science.gov (United States)

    Eccles, J. V.; Rice, D. D.; Sojka, J. J.; Marshall, R. A.; Drob, D. P.; Decena, J. C.

    2017-12-01

    The solar eclipse of 2017 August 21 provides an excellent opportunity to examine Very Low Frequency (VLF) radio signal propagation through the path of the solar eclipse between Navy VLF transmitters and several VLF receivers. The VLF transmitters available for this study radio signal propagation study are NLK in Jim Creek, Washington (24.8 kHz, 192 kW, 48.20N, 121.90W), NML in LaMour, North Dakota (25.2 kHz, 500 kW 46.37N, 93.34W), and NAA in Cutler, Maine (24.0 kHz, 1000 kW, 44.65N, 67.29W). These VLF transmitters provide propagation paths to three VLF receivers at Utah State University (41.75N, 111.76W), Bear Lake Observatory (41.95N, 111.39W), Salt Lake City (40.76N, 111.89W) and one receiver in Boulder, Colorado (40.02N, 105.27W). The solar eclipse shadow will cross all propagations paths during the day and will modify the D region electron density within the solar shadow. The week prior to the solar eclipse will be used to generate a diurnal baseline of VLF single strength for each transmitter-receiver pair. These will be compared to the day of the solar eclipse to identify VLF propagation differences through the solar eclipse shawdow. Additionally, the electron density effects of the week prior and of the solar eclipse day will be modeled using the Data-Driven D Region (DDDR) model [Eccles et al., 2005] with a detailed eclipse solar flux mask. The Long-Wave Propagation Code and the HASEL RF ray-tracing code will be used to generate VLF signal strength for each measured propagation path through the days prior and the solar eclipse day. Model-measurement comparisons will be presented and the D region electron density effects of the solar eclipse will be examined. The DDDR is a time-dependent D region model, which makes it very suitable for the solar eclipse effects on the electron density for the altitude range of 36 to 130 km. Eccles J. V., R. D. Hunsucker, D. Rice, J. J. Sojka (2005), Space weather effects on midlatitude HF propagation paths: Observations and

  4. Evaluation of the National Solar Radiation Database (NSRDB) Using Ground-Based Measurements

    Science.gov (United States)

    Xie, Y.; Sengupta, M.; Habte, A.; Lopez, A.

    2017-12-01

    Solar resource is essential for a wide spectrum of applications including renewable energy, climate studies, and solar forecasting. Solar resource information can be obtained from ground-based measurement stations and/or from modeled data sets. While measurements provide data for the development and validation of solar resource models and other applications modeled data expands the ability to address the needs for increased accuracy and spatial and temporal resolution. The National Renewable Energy Laboratory (NREL) has developed and regular updates modeled solar resource through the National Solar Radiation Database (NSRDB). The recent NSRDB dataset was developed using the physics-based Physical Solar Model (PSM) and provides gridded solar irradiance (global horizontal irradiance (GHI), direct normal irradiance (DNI), and diffuse horizontal irradiance) at a 4-km by 4-km spatial and half-hourly temporal resolution covering 18 years from 1998-2015. A comprehensive validation of the performance of the NSRDB (1998-2015) was conducted to quantify the accuracy of the spatial and temporal variability of the solar radiation data. Further, the study assessed the ability of NSRDB (1998-2015) to accurately capture inter-annual variability, which is essential information for solar energy conversion projects and grid integration studies. Comparisons of the NSRDB (1998-2015) with nine selected ground-measured data were conducted under both clear- and cloudy-sky conditions. These locations provide a high quality data covering a variety of geographical locations and climates. The comparison of the NSRDB to the ground-based data demonstrated that biases were within +/- 5% for GHI and +/-10% for DNI. A comprehensive uncertainty estimation methodology was established to analyze the performance of the gridded NSRDB and includes all sources of uncertainty at various time-averaged periods, a method that is not often used in model evaluation. Further, the study analyzed the inter

  5. Solar radiation transmissivity of a single-span greenhouse through measurements on scale models

    International Nuclear Information System (INIS)

    Papadakis, G.; Manolakos, D.; Kyritsis, S.

    1998-01-01

    The solar transmissivity of a single-span greenhouse has been investigated experimentally using a scale model, of dimensions 40 cm width and 80 cm length. The solar transmissivity was measured at 48 positions on the “ground” surface of the scale model using 48 small silicon solar cells. The greenhouse model was positioned horizontally on a specially made goniometric mechanism. In this way, the greenhouse azimuth could be changed so that typical days of the year could be simulated using different combinations of greenhouse azimuth and the position of the sun in the sky. The measured solar transmissivity distribution at the “ground” surface and the average greenhouse solar transmissivity are presented and analysed, for characteristic days of the year, for winter and summer for a latitude of 37°58′ (Athens, Greece). It is shown that for the latitude of 37°58′ N during winter, the E–W orientation is preferable to the N–S one. The side walls, and especially the East and West ones for the E–W orientation, reduce considerably the greenhouse transmissivity at areas close to the walls for long periods of the day when the angle of incidence of the solar rays to these walls is large. (author)

  6. Solar Cycle Variations in Polar Cap Area Measured by the SuperDARN Radars

    Science.gov (United States)

    Imber, S. M.; Milan, S. E.; Lester, M.

    2013-12-01

    We present a long term study, from January 1996 - August 2012, of the latitude of the Heppner-Maynard Boundary (HMB) measured at midnight using the northern hemisphere SuperDARN radars. The HMB represents the equatorward extent of ionospheric convection, and is used in this study as a measure of the global magnetospheric dynamics and activity. We find that the yearly distribution of HMB latitudes is single-peaked at 64° magnetic latitude for the majority of the 17-year interval. During 2003 the envelope of the distribution shifts to lower latitudes and a second peak in the distribution is observed at 61°. The solar wind-magnetosphere coupling function derived by Milan et al. (2012) suggests that the solar wind driving during this year was significantly higher than during the rest of the 17-year interval. In contrast, during the period 2008-2011 HMB distribution shifts to higher latitudes, and a second peak in the distribution is again observed, this time at 68° magnetic latitude. This time interval corresponds to a period of extremely low solar wind driving during the recent extreme solar minimum. This is the first statistical study of the polar cap area over an entire solar cycle, and the results demonstrate that there is a close relationship between the phase of the solar cycle and the area of the polar cap on a large scale statistical basis.

  7. 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.

  8. 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.

  9. Indoor measurement of angle resolved light absorption by antireflective glass in solar panels

    DEFF Research Database (Denmark)

    Amdemeskel, Mekbib Wubishet; Benatto, Gisele Alves dos Reis; Riedel, Nicholas

    2017-01-01

    measurements with trackers. The experimental results showed optical responses that are stable and suitable for indoor characterization of solar cells. We find the characteristic optical response of six different antireflective glasses, and based on such measurements, we perform PVsyst simulations and present...

  10. Results of the round robin exercise on IV-measurements of classic Si-solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Van der Borg, N.J.C.M. [ECN Solar Energy, Petten (Netherlands)

    2012-12-15

    A round robin exercise was performed on IV measurements and spectral response measurements of solar cells. Seven partners participated in the exercise. The aim of the round robin was to enable the verification of their measurement facilities and procedures for IV-measurements on 'classic' Si-solar cells by comparing their measurement data with the other participants. In this way possible flaws in the equipment or procedures can be found and corrected for or the measurement uncertainties can be reassessed. The differences between the measurement results of the various partners were more or less within the expected measurement uncertainty although one or more partners may decide to use the results to reexamine their facilities or procedures.

  11. Precision Measurement of the Beryllium-7 Solar Neutrino Interaction Rate in Borexino

    Science.gov (United States)

    Saldanha, Richard Nigel

    Solar neutrinos, since their first detection nearly forty years ago, have revealed valuable information regarding the source of energy production in the Sun, and have demonstrated that neutrino oscillations are well described by the Large Mixing Angle (LMA) oscillation parameters with matter interactions due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. This thesis presents a precision measurement of the 7Be solar neutrino interaction rate within Borexino, an underground liquid scintillator detector that is designed to measure solar neutrino interactions through neutrino-electron elastic scattering. The thesis includes a detailed description of the analysis techniques developed and used for this measurement as well as an evaluation of the relevant systematic uncertainties that affect the precision of the result. The rate of neutrino-electron elastic scattering from 0.862 MeV 7Be neutrinos is determined to be 45.4 +/- 1.6 (stat) +/- 1.5 (sys) counts/day/100 ton. Due to extensive detector calibrations and improved analysis methods, the systematic uncertainty in the interaction rate has been reduced by more than a factor of two from the previous evaluation. In the no-oscillation hypothesis, the interaction rate corresponds to a 0.862 MeV 7Be electron neutrino flux of (2.75 +/- 0.13) x 10 9 cm-2 sec-1. Including the predicted neutrino flux from the Standard Solar Model yields an electron neutrino survival probability of Pee 0.51 +/- 0.07 and rules out the no-oscillation hypothesis at 5.1sigma The LMA-MSW neutrino oscillation model predicts a transition in the solar Pee value between low ( 10 MeV) energies which has not yet been experimentally confirmed. This result, in conjunction with the Standard Solar Model, represents the most precise measurement of the electron neutrino survival probability for solar neutrinos at sub-MeV energies.

  12. The Impact of Indoor and Outdoor Radiometer Calibration on Solar Measurements: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Reda, Ibrahim; Robinson, Justin

    2016-07-01

    Accurate solar radiation data sets are critical to reducing the expenses associated with mitigating performance risk for solar energy conversion systems, and they help utility planners and grid system operators understand the impacts of solar resource variability. The accuracy of solar radiation measured by radiometers depends on the instrument performance specification, installation method, calibration procedure, measurement conditions, maintenance practices, location, and environmental conditions. This study addresses the effect of calibration methodologies and the resulting calibration responsivities provided by radiometric calibration service providers such as the National Renewable Energy Laboratory (NREL) and manufacturers of radiometers. Some of these radiometers are calibrated indoors, and some are calibrated outdoors. To establish or understand the differences in calibration methodology, we processed and analyzed field-measured data from these radiometers. This study investigates calibration responsivities provided by NREL's broadband outdoor radiometer calibration (BORCAL) and a few prominent manufacturers. The reference radiometer calibrations are traceable to the World Radiometric Reference. These different methods of calibration demonstrated 1% to 2% differences in solar irradiance measurement. Analyzing these values will ultimately assist in determining the uncertainties of the radiometer data and will assist in developing consensus on a standard for calibration.

  13. Spectroscopic data

    CERN Document Server

    Melzer, J

    1976-01-01

    During the preparation of this compilation, many people contributed; the compilers wish to thank all of them. In particular they appreciate the efforts of V. Gilbertson, the manuscript typist, and those of K. C. Bregand, J. A. Kiley, and W. H. McPherson, who gave editorial assistance. They would like to thank Dr. J. R. Schwartz for his cooperation and encouragement. In addition, they extend their grati­ tude to Dr. L. Wilson of the Air Force Weapons Laboratory, who gave the initial impetus to this project. v Contents I. I ntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . 11. Organization ofthe Spectroscopic Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Methods of Production and Experimental Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Band Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2...

  14. Proposal of AAA-battery-size one-shot ATR Fourier spectroscopic imager for on-site analysis: Simultaneous measurement of multi-components with high accuracy

    Science.gov (United States)

    Hosono, Satsuki; Qi, Wei; Sato, Shun; Suzuki, Yo; Fujiwara, Masaru; Hiramatsu, Hiroyuki; Suzuki, Satoru; Abeygunawardhana, P. K. W.; Wada, Kenji; Nishiyama, Akira; Ishimaru, Ichiro

    2015-03-01

    For simultaneous measurement of multi-components on-site like factories, the ultra-compact (diameter: 9[mm], length: 45[mm], weight: 200[g]) one-shot ATR (Attenuated Total Reflection) Fourier spectroscopic imager was proposed. Because the proposed one-shot Fourier spectroscopic imaging is based on spatial-phase-shift interferometer, interferograms could be obtained with simple optical configurations. We introduced the transmission-type relativeinclined phase-shifter, that was constructed with a cuboid prism and a wedge prism, onto the optical Fourier transform plane of infinity corrected optical systems. And also, small light-sources and cameras in the mid-infrared light region, whose size are several millimeter on a side, are essential components for the ultra-compact spectroscopic configuration. We selected the Graphite light source (light source area: 1.7×1.7[mm], maker: Hawkeye technologies) whose radiation factor was high. Fortunately, in these days we could apply the cost-effective 2-dimensional light receiving device for smartphone (e.g. product name: LEPTON, maker: FLIR, price: around 400USD). In the case of alcoholic drinks factory, conventionally workers measure glucose and ethanol concentrations by bringing liquid solution back to laboratories every day. The high portable spectroscopy will make it possible to measure multi-components simultaneously on manufacturing scene. But we found experimentally that absorption spectrum of glucose and water and ethanol were overlapped each other in near infrared light region. But for mid-infrared light region, we could distinguish specific absorption peaks of glucose (@10.5[μm]) and ethanol (@11.5[μm]) independently from water absorption. We obtained standard curve between absorption (@9.6[μm]) and ethanol concentration with high correlation coefficient 0.98 successfully by ATR imaging-type 2-dimensional Fourier spectroscopy (wavelength resolution: 0.057[μm]) with the graphite light source (maker: Hawkeye

  15. Spectroscopic factors measurement of the five first energy levels of lead 208 nucleus using the 208Pb(e,e'p207Tl* huge pulse transfer reaction

    International Nuclear Information System (INIS)

    Medaglia, R.

    1999-08-01

    In this work, the spectral functions and the spectroscopic factors of the first five energy levels of the lead 208 nucleus have been measured using the 208 Pb(e,e'p) 207 Tl * reaction. The aim is to characterize the effect of the nuclear environment on pulse and energy distributions of protons. In order to minimize the ejected proton-residual nucleus interactions in the final state, the measurement has been performed at 750 and 570 MeV/c pulse transfers, and thus for proton kinetic energies of 263 MeV and 161 MeV, contrarily to a previous measurement performed at 100 MeV. A kinematics with a transverse electromagnetic coupling, instead of a longitudinal one, has been used because of the important coupling dependence observed for medium nuclei. The experiment has been carried out at the NIKHEF electron accelerator and smoothing ring. The pulse distributions of the first five energy levels for a proton pulse range of 0 to 300 MeV/c have been extracted from the (e,e'p) cross sections. An integration of model-dependent distributions gives the spectroscopic factors which indicate the number of protons of each level. These data rae compared to models that include both the proton interactions in the final state and the coulomb distortions. The Pavie model reproduces well the observed distributions and the transfer dependence, while the Ohio model does not. The spectroscopic factors obtained with the Pavie model are the same for both transfers and are 20% higher as an average than the previous experiment performed at 450 MeV/c. However, they are 30% below the shell model. The uncertain estimation of the reaction mechanisms does not allow to consider this reduction as being due exclusively to nuclear structure effects. (J.S.)

  16. Spectroscopic measurement of H(1S) and H sub 2 (v double prime ,J double prime ) in an H sup minus ion source plasma

    Energy Technology Data Exchange (ETDEWEB)

    Stutzin, G.C.

    1990-08-01

    Low pressure H{sub 2} discharges have been used for some time as sources of H{sup {minus}} ions. These discharges contain many different species of particles which interact with each other and with the walls of the discharge chamber. Models exist that predict the populations of the various species for given macroscopic discharge parameters. However, many of the cross sections and wall catalyzation coefficients are unknown or somewhat uncertain. Therefore, it is of interest to measure the populations of as many of these species as possible, in order to determine the validity of the models. These models predict that H{sup {minus}} is created predominantly by the two-step process of vibrational excitation of hydrogen molecules followed by dissociative attachment of slow electrons to these vibrationally-excited hydrogen molecules. Many different collisional processes must be included in the models to explain the dependence of the various populations upon macroscopic parameters. This work presents results of spectroscopic measurements of the density and translational temperature of hydrogen atoms and of specific rotationally- and vibrationally-excited states of electronic ground-state H{sub 2}, in a discharge optimized for H{sup {minus}} production, as well as conventional measurements of the various charged species within the plasma. The spectroscopic measurements are performed directly by narrowband, single-photon absorption in the vacuum ultraviolet.

  17. Spectroscopic measurement of H(1S) and H2(v double-prime,J double-prime) in an H- ion source plasma

    International Nuclear Information System (INIS)

    Stutzin, G.C.

    1990-08-01

    Low pressure H 2 discharges have been used for some time as sources of H - ions. These discharges contain many different species of particles which interact with each other and with the walls of the discharge chamber. Models exist that predict the populations of the various species for given macroscopic discharge parameters. However, many of the cross sections and wall catalyzation coefficients are unknown or somewhat uncertain. Therefore, it is of interest to measure the populations of as many of these species as possible, in order to determine the validity of the models. These models predict that H - is created predominantly by the two-step process of vibrational excitation of hydrogen molecules followed by dissociative attachment of slow electrons to these vibrationally-excited hydrogen molecules. Many different collisional processes must be included in the models to explain the dependence of the various populations upon macroscopic parameters. This work presents results of spectroscopic measurements of the density and translational temperature of hydrogen atoms and of specific rotationally- and vibrationally-excited states of electronic ground-state H 2 , in a discharge optimized for H - production, as well as conventional measurements of the various charged species within the plasma. The spectroscopic measurements are performed directly by narrowband, single-photon absorption in the vacuum ultraviolet

  18. Uniform and non-uniform modes of nanosecond-pulsed dielectric barrier discharge in atmospheric air: fast imaging and spectroscopic measurements of electric field.

    Science.gov (United States)

    Liu, Chong; Dobrynin, Danil; Fridman, Alexander

    2014-06-25

    In this study, we report experimental results on fast ICCD imaging of development of nanosecond-pulsed dielectric barrier discharge (DBD) in atmospheric air and spectroscopic measurements of electric field in the discharge. Uniformity of the discharge images obtained with nanosecond exposure times were analyzed using chi-square test. The results indicate that DBD uniformity strongly depends on applied (global) electric field in the discharge gap, and is a threshold phenomenon. We show that in the case of strong overvoltage on the discharge gap (provided by fast rise times), there is transition from filamentary to uniform DBD mode which correlates to the corresponding decrease of maximum local electric field in the discharge.

  19. Measured performance of 12 demonstation projects - IEA Task 13 "advanced solar low energy buildings"

    DEFF Research Database (Denmark)

    Thomsen, Kirsten Engelund; Schultz, Jørgen Munthe; Poel, Bart

    2005-01-01

    This paper presents the results obtained from measurements and experiences gained from interviews on 12 advanced solar low energy houses designed and built as part of the IEA Solar Heating and Cooling Programme – Task 13. Three years after the IEA Task 13 formally ended, the results were collected...... climate conditions are compared and differences explained. Special innovative installations and systems are de-scribed and evaluated. In general the measured energy consumption was higher than the expected values due to user influence and unforeseen technical problems but still an energy saving of 60...

  20. SphinX MEASUREMENTS OF THE 2009 SOLAR MINIMUM X-RAY EMISSION

    OpenAIRE

    Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Kuzin, S.; Farnik, F.; Reale, F.; Phillips, K. J. H.; Bakala, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B.

    2012-01-01

    The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 x 10^47 cm^-3 and 1.1 x 10^48 cm^-3. Comparing Sph...

  1. Estimating random transverse velocities in the fast solar wind from EISCAT Interplanetary Scintillation measurements

    Directory of Open Access Journals (Sweden)

    A. Canals

    2002-09-01

    Full Text Available Interplanetary scintillation measurements can yield estimates of a large number of solar wind parameters, including bulk flow speed, variation in bulk velocity along the observing path through the solar wind and random variation in transverse velocity. This last parameter is of particular interest, as it can indicate the flux of low-frequency Alfvén waves, and the dissipation of these waves has been proposed as an acceleration mechanism for the fast solar wind. Analysis of IPS data is, however, a significantly unresolved problem and a variety of a priori assumptions must be made in interpreting the data. Furthermore, the results may be affected by the physical structure of the radio source and by variations in the solar wind along the scintillation ray path. We have used observations of simple point-like radio sources made with EISCAT between 1994 and 1998 to obtain estimates of random transverse velocity in the fast solar wind. The results obtained with various a priori assumptions made in the analysis are compared, and we hope thereby to be able to provide some indication of the reliability of our estimates of random transverse velocity and the variation of this parameter with distance from the Sun.Key words. Interplanetary physics (MHD waves and turbulence; solar wind plasma; instruments and techniques

  2. Estimating random transverse velocities in the fast solar wind from EISCAT Interplanetary Scintillation measurements

    Directory of Open Access Journals (Sweden)

    A. Canals

    Full Text Available Interplanetary scintillation measurements can yield estimates of a large number of solar wind parameters, including bulk flow speed, variation in bulk velocity along the observing path through the solar wind and random variation in transverse velocity. This last parameter is of particular interest, as it can indicate the flux of low-frequency Alfvén waves, and the dissipation of these waves has been proposed as an acceleration mechanism for the fast solar wind. Analysis of IPS data is, however, a significantly unresolved problem and a variety of a priori assumptions must be made in interpreting the data. Furthermore, the results may be affected by the physical structure of the radio source and by variations in the solar wind along the scintillation ray path. We have used observations of simple point-like radio sources made with EISCAT between 1994 and 1998 to obtain estimates of random transverse velocity in the fast solar wind. The results obtained with various a priori assumptions made in the analysis are compared, and we hope thereby to be able to provide some indication of the reliability of our estimates of random transverse velocity and the variation of this parameter with distance from the Sun.

    Key words. Interplanetary physics (MHD waves and turbulence; solar wind plasma; instruments and techniques

  3. Results from an International Measurement Round Robin of III-V Triple Junction Solar Cells under Air Mass Zero

    Science.gov (United States)

    Jenkins, Phillip; Scheiman, Chris; Goodbody, Chris; Baur, Carsten; Sharps, Paul; Imaizumi, Mitsuru; Yoo, Henry; Sahlstrom, Ted; Walters, Robert; Lorentzen, Justin; hide

    2006-01-01

    This paper reports the results of an international measurement round robin of monolithic, triple-junction, GaInP/GaAs/Ge space solar cells. Eight laboratories representing national labs, solar cell vendors and space solar cell consumers, measured cells using in-house reference cells and compared those results to measurements made where each lab used the same set of reference cells. The results show that most of the discrepancy between laboratories is likely due to the quality of the standard cells rather than the measurement system or solar simulator used.

  4. Ground-based spectral measurements of solar radiation, (2)

    International Nuclear Information System (INIS)

    Murai, Keizo; Kobayashi, Masaharu; Goto, Ryozo; Yamauchi, Toyotaro

    1979-01-01

    A newly designed spectro-pyranometer was used for the measurement of the global (direct + diffuse) and the diffuse sky radiation reaching the ground. By the subtraction of the diffuse component from the global radiation, we got the direct radiation component which leads to the spectral distribution of the optical thickness (extinction coefficient) of the turbid atmosphere. The measurement of the diffuse sky radiation reveals the scattering effect of aerosols and that of the global radiation allows the estimation of total attenuation caused by scattering and absorption of aerosols. The effects of the aerosols are represented by the deviation of the real atmosphere measured from the Rayleigh atmosphere. By the combination of the measured values with those obtained by theoretical calculation for the model atmosphere, we estimated the amount of absorption by the aerosols. Very strong absorption in the ultraviolet region was recognized. (author)

  5. EISCAT measurements of solar wind velocity and the associated level of interplanetary scintillation

    Directory of Open Access Journals (Sweden)

    R. A. Fallows

    2002-09-01

    Full Text Available A relative scintillation index can be derived from EISCAT observations of Interplanetary Scintillation (IPS usually used to study the solar wind velocity. This provides an ideal opportunity to compare reliable measurements of the solar wind velocity derived for a number of points along the line-of-sight with measurements of the overall level of scintillation. By selecting those occasions where either slow- or fast-stream scattering was dominant, it is shown that at distances from the Sun greater than 30 RS , in both cases the scintillation index fell with increasing distance as a simple power law, typically as R-1.7. The level of scintillation for slow-stream scattering is found to be 2.3 times the level for fast-stream scattering.Key words. Interplanetary physics (solar wind plasma

  6. Statistical Prediction of Solar Particle Event Frequency Based on the Measurements of Recent Solar Cycles for Acute Radiation Risk Analysis

    Science.gov (United States)

    Myung-Hee, Y. Kim; Shaowen, Hu; Cucinotta, Francis A.

    2009-01-01

    Large solar particle events (SPEs) present significant acute radiation risks to the crew members during extra-vehicular activities (EVAs) or in lightly shielded space vehicles for space missions beyond the protection of the Earth's magnetic field. Acute radiation sickness (ARS) can impair performance and result in failure of the mission. Improved forecasting capability and/or early-warning systems and proper shielding solutions are required to stay within NASA's short-term dose limits. Exactly how to make use of observations of SPEs for predicting occurrence and size is a great challenge, because SPE occurrences themselves are random in nature even though the expected frequency of SPEs is strongly influenced by the time position within the solar activity cycle. Therefore, we developed a probabilistic model approach, where a cumulative expected occurrence curve of SPEs for a typical solar cycle was formed from a non-homogeneous Poisson process model fitted to a database of proton fluence measurements of SPEs that occurred during the past 5 solar cycles (19 - 23) and those of large SPEs identified from impulsive nitrate enhancements in polar ice. From the fitted model, the expected frequency of SPEs was estimated at any given proton fluence threshold (Phi(sub E)) with energy (E) >30 MeV during a defined space mission period. Corresponding Phi(sub E) (E=30, 60, and 100 MeV) fluence distributions were simulated with a random draw from a gamma distribution, and applied for SPE ARS risk analysis for a specific mission period. It has been found that the accurate prediction of deep-seated organ doses was more precisely predicted at high energies, Phi(sub 100), than at lower energies such as Phi(sub 30) or Phi(sub 60), because of the high penetration depth of high energy protons. Estimates of ARS are then described for 90th and 95th percentile events for several mission lengths and for several likely organ dose-rates. The ability to accurately measure high energy protons

  7. Autocorrelation Study of Solar Wind Plasma and IMF Properties as Measured by the MAVEN Spacecraft

    Science.gov (United States)

    Marquette, Melissa L.; Lillis, Robert J.; Halekas, J. S.; Luhmann, J. G.; Gruesbeck, J. R.; Espley, J. R.

    2018-04-01

    It has long been a goal of the heliophysics community to understand solar wind variability at heliocentric distances other than 1 AU, especially at ˜1.5 AU due to not only the steepening of solar wind stream interactions outside 1 AU but also the number of missions available there to measure it. In this study, we use 35 months of solar wind and interplanetary magnetic field (IMF) data taken at Mars by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft to conduct an autocorrelation analysis of the solar wind speed, density, and dynamic pressure, which is derived from the speed and density, as well as the IMF strength and orientation. We found that the solar wind speed is coherent, that is, has an autocorrelation coefficient above 1/e, over roughly 56 hr, while the density and pressure are coherent over smaller intervals of roughly 25 and 20 hr, respectively, and that the IMF strength is coherent over time intervals of approximately 20 hr, while the cone and clock angles are considerably less steady but still somewhat coherent up to time lags of roughly 16 hr. We also found that when the speed, density, pressure, or IMF strength is higher than average, the solar wind or IMF becomes uncorrelated more quickly, while when they are below average, it tends to be steadier. This analysis allows us to make estimates of the values of solar wind plasma and IMF parameters when they are not directly measured and provide an approximation of the error associated with that estimate.

  8. A novel experimental mechanics method for measuring the light pressure acting on a solar sail membrane

    Science.gov (United States)

    Shi, Aiming; Jiang, Li; Dowell, Earl H.; Qin, Zhixuan

    2017-02-01

    Solar sail is a high potential `sailing craft' for interstellar exploration. The area of the first flight solar sail demonstrator named "IKAROS" is 200 square meters. Future interplanetary missions will require solar sails at least on the order of 10000 square meters (or larger). Due to the limitation of ground facilities, the size of experimental sample should not be large. Furthermore the ground experiments have to be conducted in gravitational field, so the gravity effect must be considered in a ground test. To obtain insight into the solar sail membrane dynamics, a key membrane flutter (or limit cycle oscillations) experiment with light forces acting on it must be done. But one big challenge is calibrating such a tiny light force by as a function of the input power. In this paper, a gravity-based measuring method for light pressure acting on membrane is presented. To explain the experimental principle, an ideal example of a laser beam with expanders and a metal film is studied. Based on calculations, this experimental mechanics method for calibrating light pressure with an accuracy of 0.01 micro-Newton may be realized by making the light force balance the gravity force on the metal films. This gravity-based measuring method could not only be applied to study the dynamics characteristics of solar sail membrane structure with different light forces, but could also be used to determine more accurate light forces/loads acting on solar sail films and hence to enhance the determination of the mechanical properties of the solar sail membrane structure.

  9. Equatorial thermospheric wind changes during the solar cycle: Measurements at Arequipa, Peru, from 1983 to 1990

    International Nuclear Information System (INIS)

    Biondi, M.A.; Meriwether, J.W. Jr.; Fejer, B.G.; Gonzalez, S.A.; Hallenbeck, D.C.

    1991-01-01

    Fabry-Perot interferometer measurements of Doppler shifts in the nightglow 630-nm emission line have been used to determine near-equatorial thermospheric wind velocities at Arequipa, Peru, over ∼ 2/3 of a solar cycle. Monthly-average nocturnal variations in the meridional and zonal wind components were calculated from the nightly data to remove short term (day-to-day) variability, facilitating display of seasonal changes in the wind patterns, as well as any additional changes introduced by the progression of the solar cycle. The measured seasonal variations in the wind patterns are more pronounced than the solar cycle variations and are more readily understandable in terms of the expected, underlying forcing and damping processes. For most of the years, at the winter solstice, there is a weak (≤ 100 m/s) transequatorial flow from the summer to the winter hemisphere in the early and the late night, with essentially zero velocities in between. At the equinoxes, an early-night poleward (southward) flow at solar minimum (1986) is replaced by an equatorward (northward) flow at solar maximum (1989-1990). The zonal flows are predominantly eastward throughout the night, except for the solar minimum equinoxes, where brief westward flows appear in the early and the late night. The peak eastward velocities increase toward solar maximum; at the winter solstice, they are ∼ 100-130 m/s in 1983, 1984 and 1986, reaching ∼ 200 m/s in 1988, 1989 and 1990. The present equatorial thermospheric wind determinations agree in some respects with the satellite-data-based horizontal wind model IIWM-87 and the vector spherical harmonic form of the thermospheric general circulation model

  10. Solar intensity measurement using a thermoelectric module; experimental study and mathematical modeling

    International Nuclear Information System (INIS)

    Rahbar, Nader; Asadi, Amin

    2016-01-01

    Highlights: • Solar intensity could be explained as a linear function of voltage and ambient temperature. • The maximum output voltage is approximately 120 mV which was occurred in midday. • The average value of the heat-sink thermal resistance could be measured with this device. • The average values of total heat transfer coefficients could be measured with this device. • Two correlations were proposed to predict the solar intensity with the accuracy of 10%. - Abstract: The present study is intended to design, manufacture, and modeling an inexpensive pyranometer using a thermoelectric module. The governing equations relating the solar intensity, output voltage, and ambient temperature have been derived by applying the mathematical and thermodynamic models. According to the thermodynamics modeling, the output voltage is a function of solar intensity, ambient temperature, internal parameters of thermoelectric module, convection and radiation coefficients, and geometrical characteristics of the setup. Moreover, the solar intensity can be considered as a linear function of voltage and ambient temperature within an acceptable range of accuracy. The experiments have been carried out on a typical winter day under climatic conditions of Semnan (35°33′N, 53°23′E), Iran. The results also indicated that the output voltage is dependent on the solar intensity and its maximum value was 120 mV. Finally, based on the experimental results, two correlations, with the accuracy of 10%, have been proposed to predict the solar intensity as a function of output voltage and ambient temperature. The average values of total heat transfer coefficient and thermal resistance of the heat-sink have been also calculated according to the thermodynamic modeling and experimental results.

  11. Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

    International Nuclear Information System (INIS)

    Thorseth, Trond Morten

    2000-01-01

    The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe

  12. Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

    Energy Technology Data Exchange (ETDEWEB)

    Thorseth, Trond Morten

    2000-07-01

    The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe.

  13. Sol–gel derived solar selective coatings on SS 321 substrates for solar thermal applications

    Energy Technology Data Exchange (ETDEWEB)

    Subasri, R., E-mail: subasri@arci.res.in; Soma Raju, K.R.C.; Reddy, D.S.; Hebalkar, Neha Y.; Padmanabham, G.

    2016-01-01

    Sol–gel derived multilayered solar selective coatings were generated on AISI SS 321 substrates using Ag-TiO{sub 2} as the cermet layer, titania and silica as the dielectric layers with high and low refractive indices respectively. The phase compositions of the individual layers were independently confirmed using grazing angle incidence X-ray diffraction, which was corroborated by X-ray photoelectron spectroscopic analysis. Thickness of the layers was measured using variable angle spectroscopic ellipsometry. The solar absorbance was measured over the UV–Vis-NIR wavelength range. Thermal emissivity was determined using FTIR spectroscopic analysis. The durability of the coatings was ascertained using accelerated corrosion testing methods as well as by measuring the optical properties after thermal cycling experiments. The promising nature of hexavalent chrome-free, environmental friendly, multilayered solar selective coating was ascertained with respect to amenability to scale-up. - Highlights: • Sol–gel derived multilayered solar selective coatings developed on SS321 • Solar absorptance and thermal emittance at par with toxic chrome coating • Thermal stability and corrosion resistance of coatings studied • Coating performance found to be promising for large scale applications • Scale-up amenability investigated by coating generation on 1 m tubes.

  14. Sol–gel derived solar selective coatings on SS 321 substrates for solar thermal applications

    International Nuclear Information System (INIS)

    Subasri, R.; Soma Raju, K.R.C.; Reddy, D.S.; Hebalkar, Neha Y.; Padmanabham, G.

    2016-01-01

    Sol–gel derived multilayered solar selective coatings were generated on AISI SS 321 substrates using Ag-TiO_2 as the cermet layer, titania and silica as the dielectric layers with high and low refractive indices respectively. The phase compositions of the individual layers were independently confirmed using grazing angle incidence X-ray diffraction, which was corroborated by X-ray photoelectron spectroscopic analysis. Thickness of the layers was measured using variable angle spectroscopic ellipsometry. The solar absorbance was measured over the UV–Vis-NIR wavelength range. Thermal emissivity was determined using FTIR spectroscopic analysis. The durability of the coatings was ascertained using accelerated corrosion testing methods as well as by measuring the optical properties after thermal cycling experiments. The promising nature of hexavalent chrome-free, environmental friendly, multilayered solar selective coating was ascertained with respect to amenability to scale-up. - Highlights: • Sol–gel derived multilayered solar selective coatings developed on SS321 • Solar absorptance and thermal emittance at par with toxic chrome coating • Thermal stability and corrosion resistance of coatings studied • Coating performance found to be promising for large scale applications • Scale-up amenability investigated by coating generation on 1 m tubes

  15. Spectroscopic study

    International Nuclear Information System (INIS)

    Flores, M.; Rodriguez, R.; Arroyo, R.

    1999-01-01

    This work is focused about the spectroscopic properties of a polymer material which consists of Polyacrylic acid (Paa) doped at different concentrations of Europium ions (Eu 3+ ). They show that to stay chemically joined with the polymer by a study of Nuclear Magnetic Resonance (NMR) of 1 H, 13 C and Fourier Transform Infrared Spectroscopy (Ft-IR) they present changes in the intensity of signals, just as too when this material is irradiated at λ = 394 nm. In according with the results obtained experimentally in this type of materials it can say that is possible to unify chemically the polymer with this type of cations, as well as, varying the concentration of them, since that these are distributed homogeneously inside the matrix maintaining its optical properties. These materials can be obtained more quickly and easy in solid or liquid phase and they have the best conditions for to make a quantitative analysis. (Author)

  16. Surface Net Solar Radiation Estimated from Satellite Measurements: Comparisons with Tower Observations

    Science.gov (United States)

    Li, Zhanqing; Leighton, H. G.; Cess, Robert D.

    1993-01-01

    A parameterization that relates the reflected solar flux at the top of the atmosphere to the net solar flux at the surface in terms of only the column water vapor amount and the solar zenith angle was tested against surface observations. Net surface fluxes deduced from coincidental collocated satellite-measured radiances and from measurements from towers in Boulder during summer and near Saskatoon in winter have mean differences of about 2 W/sq m, regardless of whether the sky is clear or cloudy. Furthermore, comparisons between the net fluxes deduced from the parameterization and from surface measurements showed equally good agreement when the data were partitioned into morning and afternoon observations. This is in contrast to results from an empirical clear-sky algorithm that is unable to account adequately for the effects of clouds and that shows, at Boulder, a distinct morning to afternoon variation, which is presumably due to the predominance of different cloud types throughout the day. It is also demonstrated that the parameterization may be applied to irradiances at the top of the atmosphere that have been temporally averaged by using the temporally averaged column water vapor amount and the temporally averaged cosine of the solar zenith angle. The good agreement between the results of the parameterization and surface measurements suggests that the algorithm is a useful tool for a variety of climate studies.

  17. Measurement of Minority-Carrier Lifetime in Silicon Solar Cells by ...

    African Journals Online (AJOL)

    This manuscript describes the measurement of minority - carrier lifetime of silicon solar cells, at room temperature, by photoconductive decay method. The Holobeam, Model 655 Double-Pulsed Holographic system, is used as the light source. This consists of a Q-switched, pulsed ruby laser oscillator with two ruby laser ...

  18. Measuring the iron spectral opacity in solar conditions using a double ablation front scheme

    Energy Technology Data Exchange (ETDEWEB)

    Colaitis, A. [Centre Lasers Intenses et Applications, Talence (France); CEA/DRF/IRFU/DAp, CEA Saclay (France); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Ducret, J. E. [Centre Lasers Intenses et Applications, Talence (France); CEA/DRF/IRFU/DAp, CEA Saclay (France); Turck-Chieze, S [CEA/DRF/IRFU/DAp, CEA Saclay (France); Pennec, M L [CEA/DRF/IRFU/DAp, CEA Saclay (France); CEA/DIF, Arpajon (France); Blancard, C [CEA/DIF, Arpajon (France)

    2018-01-22

    We propose a new method to achieve hydrodynamic conditions relevant for the investigation of the radiation transport properties of the plasma at the base of the solar convection zone. The method is designed in the framework of opacity measurements with high-power lasers and exploits the temporal and spatial stability of hydrodynamic parameters in counter-propagating Double Ablation Front (DAF) structures.

  19. Artifact Interpretation of Spectral Response Measurements on Two-Terminal Multijunction Solar Cells

    NARCIS (Netherlands)

    Si, F.T.; Isabella, O.; Zeman, M.

    2016-01-01

    Multijunction solar cells promise higher power-conversion efficiency than the single-junction. With respect to two-terminal devices, an accurate measurement of the spectral response requires a delicate adjustment of the light- and voltage-biasing; otherwise it can result in artifacts in the data and

  20. Speciation of water soluble iron in size segregated airborne particulate matter using LED based liquid waveguide with a novel dispersive absorption spectroscopic measurement technique

    International Nuclear Information System (INIS)

    Chan, K.L.; Jiang, S.Y.N.; Ning, Z.

    2016-01-01

    In this study, we present the development and evaluation of a dispersive absorption spectroscopic technique for trace level soluble ferrous detection. The technique makes use of the broadband absorption spectra of the ferrous-ferrozine complex with a novel spectral fitting algorithm to determine soluble ferrous concentrations in samples and achieves much improved measurement precision compared to conventional methods. The developed method was evaluated by both model simulations and experimental investigations. The results demonstrated the robustness of the method against the spectral fluctuation, wavelength drift and electronic noise, while achieving excellent linearity (R 2  > 0.999) and low detection limit (0.06 μg L −1 ) for soluble ferrous detection. The developed method was also used for the speciation of soluble iron in size segregated atmospheric aerosols. The measurement was carried out during Spring and Summer in typical urban environment in Hong Kong. The measured total iron concentrations are in good agreement compared to conventional Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) measurements. Investigation on ambient particulate matter samples shows the size dependent characteristic of iron speciation in the atmosphere with a more active role of fine particles in transforming between ferrous and ferric. The method demonstrated in this study provides a cost and time effective approach for the speciation of iron in ambient aerosols. - Highlights: • Dispersive absorption spectroscopic technique for trace level ferrous detection. • The spectral fitting retrieval improved the measurement precision and stability. • Extremely low detection limit was achieved for aqueous ferrous measurement. • Iron in size segregated particulate matters shows seasonal characteristic. • More active role of iron was found in fine particles compared to coarse particles.

  1. Speciation of water soluble iron in size segregated airborne particulate matter using LED based liquid waveguide with a novel dispersive absorption spectroscopic measurement technique

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K.L. [Meteorological Institute, Ludwig Maximilian University of Munich, Munich (Germany); School of Energy and Environment, City University of Hong Kong (Hong Kong); Jiang, S.Y.N. [School of Energy and Environment, City University of Hong Kong (Hong Kong); Ning, Z., E-mail: zhining@cityu.edu.hk [School of Energy and Environment, City University of Hong Kong (Hong Kong); Guy Carpenter Climate Change Centre, City University of Hong Kong (Hong Kong)

    2016-03-31

    In this study, we present the development and evaluation of a dispersive absorption spectroscopic technique for trace level soluble ferrous detection. The technique makes use of the broadband absorption spectra of the ferrous-ferrozine complex with a novel spectral fitting algorithm to determine soluble ferrous concentrations in samples and achieves much improved measurement precision compared to conventional methods. The developed method was evaluated by both model simulations and experimental investigations. The results demonstrated the robustness of the method against the spectral fluctuation, wavelength drift and electronic noise, while achieving excellent linearity (R{sup 2} > 0.999) and low detection limit (0.06 μg L{sup −1}) for soluble ferrous detection. The developed method was also used for the speciation of soluble iron in size segregated atmospheric aerosols. The measurement was carried out during Spring and Summer in typical urban environment in Hong Kong. The measured total iron concentrations are in good agreement compared to conventional Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) measurements. Investigation on ambient particulate matter samples shows the size dependent characteristic of iron speciation in the atmosphere with a more active role of fine particles in transforming between ferrous and ferric. The method demonstrated in this study provides a cost and time effective approach for the speciation of iron in ambient aerosols. - Highlights: • Dispersive absorption spectroscopic technique for trace level ferrous detection. • The spectral fitting retrieval improved the measurement precision and stability. • Extremely low detection limit was achieved for aqueous ferrous measurement. • Iron in size segregated particulate matters shows seasonal characteristic. • More active role of iron was found in fine particles compared to coarse particles.

  2. Study of solar activity by measuring cosmic rays with a water Cherenkov detector

    International Nuclear Information System (INIS)

    Bahena Bias, Angelica; Villasenor, Luis

    2011-01-01

    We report on an indirect study of solar activity by using the Forbush effect which consists on the anti-correlation between the intensity of solar activity and the intensity of secondary cosmic radiation detected at ground level at the Earth. We have used a cylindrical water Cherenkov detector to measure the rate of arrival of secondary cosmic rays in Morelia Mich., Mexico, at 1950 m.a.s.l. We describe the analysis required to unfold the effect of atmospheric pressure and the search for Forbush decreases in our data, the latter correspond to more than one year of continuous data collection.

  3. [Fluctuations in biophysical measurements as a result of variations in solar activity].

    Science.gov (United States)

    Peterson, T F

    1995-01-01

    A theory is proposed to explain variations in the net electrical charge of biological substances at the Earth's surface. These are shown to occur in association with changes in the solar wind and geomagnetic field. It is suggested that a liquid dielectric's net volume charge will imitate pH effects, influence chemical reaction rates, and alter ion transfer mechanisms in biophysical systems. An experiment is described which measures dielectric volume charge, or non-neutrality, to allow correlation of this property with daily, 28-day, and 11-year fluctuation patterns in geophysical and satellite data associated with solar activity and the interplanetary magnetic field.

  4. Analysis of solar irradiation measurements at Beer Sheva, Israel from 1985 through 2013

    International Nuclear Information System (INIS)

    Evseev, Efim G.; Kudish, Avraham I.

    2015-01-01

    Highlights: • In depth analysis of long-term solar irradiation at Beer Sheva, Israel. • Construction of a typical meteorological year for global and beam irradiation. • Statistical analysis of the global and beam irradiation. • Analysis of long-term trends regarding global and beam irradiation. - Abstract: An in-depth analysis of the solar horizontal global, normal incidence beam and solar global incident on a south-facing surface tilted at 40° irradiation monitored at Beer Sheva from 1985 through 2013 has been performed. The horizontal beam irradiation, daily clearness index, daily beam index and beam fraction of the horizontal global irradiation were determined from the measured parameters. A statistical analysis, which included average, median, standard deviation, maximum and minimum values and the coefficient of variation, was performed on the parameters under investigation. The monthly frequency distribution types were determined for the solar global, normal incidence beam and solar global incident on a south-facing surface tilted at 40° irradiation based upon their corresponding skewness and kurtosis values. In addition, typical meteorological years were developed for the solar horizontal global and normal incidence beam irradiation. Beer Sheva is characterized as a site with a high incidence of clear days with global irradiation consisting of a relatively high beam fraction. A relatively steep minimum in the annual average daily normal incidence beam irradiation is observed from 1991 to 1993 and has been attributed to the eruption of Mt. Pinatubo, Philippines during June 1991. A time series analysis of the both individual monthly and annual average daily global and normal incidence irradiation indicated a slight trend of solar brightening for this region during the time interval 1985 through 2013, but in most cases they were not statistically significant based upon their p values

  5. Understanding InP Nanowire Array Solar Cell Performance by Nanoprobe-Enabled Single Nanowire Measurements.

    Science.gov (United States)

    Otnes, Gaute; Barrigón, Enrique; Sundvall, Christian; Svensson, K Erik; Heurlin, Magnus; Siefer, Gerald; Samuelson, Lars; Åberg, Ingvar; Borgström, Magnus T

    2018-05-09

    III-V solar cells in the nanowire geometry might hold significant synthesis-cost and device-design advantages as compared to thin films and have shown impressive performance improvements in recent years. To continue this development there is a need for characterization techniques giving quick and reliable feedback for growth development. Further, characterization techniques which can improve understanding of the link between nanowire growth conditions, subsequent processing, and solar cell performance are desired. Here, we present the use of a nanoprobe system inside a scanning electron microscope to efficiently contact single nanowires and characterize them in terms of key parameters for solar cell performance. Specifically, we study single as-grown InP nanowires and use electron beam induced current characterization to understand the charge carrier collection properties, and dark current-voltage characteristics to understand the diode recombination characteristics. By correlating the single nanowire measurements to performance of fully processed nanowire array solar cells, we identify how the performance limiting parameters are related to growth and/or processing conditions. We use this understanding to achieve a more than 7-fold improvement in efficiency of our InP nanowire solar cells, grown from a different seed particle pattern than previously reported from our group. The best cell shows a certified efficiency of 15.0%; the highest reported value for a bottom-up synthesized InP nanowire solar cell. We believe the presented approach have significant potential to speed-up the development of nanowire solar cells, as well as other nanowire-based electronic/optoelectronic devices.

  6. Spectroscopic study on the doping of polycrystalline CdTe layers for solar cells; Spektroskopische Untersuchungen zur Dotierung von polykristallinen CdTe-Schichten fuer Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, Christian

    2011-11-29

    First in the present thesis the fundamental properties of CdTe are described. In the following it is discussed, how a CdTe solar cell is generally constructed, which specialities are to be regarded, and how an improvement of the actually reachable data of such a solar cell in view of the efficiency can be reached fundamentally and in then practical realization. In the third chapter the physical foundations of the most important methods are discussed, which are applied in the framework of this thesis for the analysis of the CdTe layers. The fourth chapter describes the details of the experiments of this thesis. The fifth chapter deals with the analysis of the photoluminescence of CdTe layers. Special attention is put on the analysis of the excitonic luminescence. The sixth chapter treats the implantation of CdTe layers with phosphor. The influence of phosphorus as dopant on the PL spectra of CdTe and the correponding characteristics of implanted solar cells are presented. Also the influence of radiation damages as consequence of the ion implantation is studied in this chapter by means of the analysis of differently thick absorber layers. In the seventh chapter finally a new procedure for the fabrication of solar cells on the base of CdTe as absorber material is introduced, which shall make possible to change the stoichiometry of cadmium mand tellurium specifically and to present additionally a suited material, in order to form the doping of CdTE a solar-cell material variably. The fundamental properties of the new facility are experimentally determined, and first solar cells are fabricated with this facility and analyzed. Also an in-situ doping with phosphorus is thereby performed and the result studied.

  7. Meridional flow in the solar convection zone. I. Measurements from gong data

    Energy Technology Data Exchange (ETDEWEB)

    Kholikov, S. [National Solar Observatories, Tucson, AZ 85719 (United States); Serebryanskiy, A. [Ulugh Beg Astronomical Institute, Uzbek Academy of Science, Tashkent 100052 (Uzbekistan); Jackiewicz, J., E-mail: kholikov@noao.edu [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States)

    2014-04-01

    Large-scale plasma flows in the Sun's convection zone likely play a major role in solar dynamics on decadal timescales. In particular, quantifying meridional motions is a critical ingredient for understanding the solar cycle and the transport of magnetic flux. Because the signal of such features can be quite small in deep solar layers and be buried in systematics or noise, the true meridional velocity profile has remained elusive. We perform time-distance helioseismology measurements on several years worth of Global Oscillation Network Group Doppler data. A spherical harmonic decomposition technique is applied to a subset of acoustic modes to measure travel-time differences to try to obtain signatures of meridional flows throughout the solar convection zone. Center-to-limb systematics are taken into account in an intuitive yet ad hoc manner. Travel-time differences near the surface that are consistent with a poleward flow in each hemisphere and are similar to previous work are measured. Additionally, measurements in deep layers near the base of the convection zone suggest a possible equatorward flow, as well as partial evidence of a sign change in the travel-time differences at mid-convection zone depths. This analysis on an independent data set using different measurement techniques strengthens recent conclusions that the convection zone may have multiple 'cells' of meridional flow. The results may challenge the common understanding of one large conveyor belt operating in the solar convection zone. Further work with helioseismic inversions and a careful study of systematic effects are needed before firm conclusions of these large-scale flow structures can be made.

  8. Scintillation measurements at Bahir Dar during the high solar activity phase of solar cycle 24

    Energy Technology Data Exchange (ETDEWEB)

    Kriegel, Martin; Jakowski, Norbert; Berdermann, Jens; Sato, Hiroatsu [German Aerospace Center (DLR), Neustrelitz (Germany). Inst. of Communications and Navigation; Mersha, Mogese Wassaie [Bahir Dar Univ. (Ethiopia). Washera Geospace and Radar Science Lab.

    2017-04-01

    Small-scale ionospheric disturbances may cause severe radio scintillations of signals transmitted from global navigation satellite systems (GNSSs). Consequently, smallscale plasma irregularities may heavily degrade the performance of current GNSSs such as GPS, GLONASS or Galileo. This paper presents analysis results obtained primarily from two high-rate GNSS receiver stations designed and operated by the German Aerospace Center (DLR) in cooperation with Bahir Dar University (BDU) at 11.6 N, 37.4 E. Both receivers collect raw data sampled at up to 50 Hz, from which characteristic scintillation parameters such as the S4 index are deduced. This paper gives a first overview of the measurement setup and the observed scintillation events over Bahir Dar in 2015. Both stations are located close to one another and aligned in an east-west, direction which allows us to estimate the zonal drift velocity and spatial dimension of equatorial ionospheric plasma irregularities. Therefore, the lag times of moving electron density irregularities and scintillation patterns are derived by applying cross-correlation analysis to high-rate measurements of the slant total electron content (sTEC) along radio links between a GPS satellite and both receivers and to the associated signal power, respectively. Finally, the drift velocity is derived from the estimated lag time, taking into account the geometric constellation of both receiving antennas and the observed GPS satellites.

  9. Energy Yield Determination of Concentrator Solar Cells using Laboratory Measurements: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Geisz, John F.; Garcia, Ivan; McMahon, William E.; Steiner, Myles A.; Ochoa, Mario; France, Ryan M.; Habte, Aron; Friedman, Daniel J.

    2015-09-14

    The annual energy conversion efficiency is calculated for a four junction inverted metamorphic solar cell that has been completely characterized in the laboratory at room temperature using measurements fit to a comprehensive optoelectronic model of the multijunction solar cells. A simple model of the temperature dependence is used to predict the performance of the solar cell under varying temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric concentration, CPV system thermal characteristics, and luminescent coupling are highlighted. temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric concentration, CPV system thermal characteristics, and luminescent coupling are highlighted.

  10. Solar Sail Models and Test Measurements Correspondence for Validation Requirements Definition

    Science.gov (United States)

    Ewing, Anthony; Adams, Charles

    2004-01-01

    Solar sails are being developed as a mission-enabling technology in support of future NASA science missions. Current efforts have advanced solar sail technology sufficient to justify a flight validation program. A primary objective of this activity is to test and validate solar sail models that are currently under development so that they may be used with confidence in future science mission development (e.g., scalable to larger sails). Both system and model validation requirements must be defined early in the program to guide design cycles and to ensure that relevant and sufficient test data will be obtained to conduct model validation to the level required. A process of model identification, model input/output documentation, model sensitivity analyses, and test measurement correspondence is required so that decisions can be made to satisfy validation requirements within program constraints.

  11. Measurements and Simulations on the Mechanisms of Efficiency Losses in HIT Solar Cells

    Directory of Open Access Journals (Sweden)

    Silvio Pierro

    2015-01-01

    Full Text Available We study the electrical and the optical behavior of HIT solar cell by means of measurements and optoelectrical simulations by TCAD simulations. We compare the HIT solar cell with a conventional crystalline silicon solar cell to identify the strengths and weaknesses of the HIT technology. Results highlight different mechanisms of electrical and optical efficiency losses caused by the presence of the amorphous silicon layer. The higher resistivity of the a-Si layers implies a smaller distance between the metal lines that causes a higher shadowing. The worst optical coupling between the amorphous silicon and the antireflective coating implies a slight increase of reflectivity around the 600 nm wavelength.

  12. Error in interpreting field chlorophyll fluorescence measurements: heat gain from solar radiation

    International Nuclear Information System (INIS)

    Marler, T.E.; Lawton, P.D.

    1994-01-01

    Temperature and chlorophyll fluorescence characteristics were determined on leaves of various horticultural species following a dark adaptation period where dark adaptation cuvettes were shielded from or exposed to solar radiation. In one study, temperature of Swietenia mahagoni (L.) Jacq. leaflets within cuvettes increased from approximately 36C to approximately 50C during a 30-minute exposure to solar radiation. Alternatively, when the leaflets and cuvettes were shielded from solar radiation, leaflet temperature declined to 33C in 10 to 15 minutes. In a second study, 16 horticultural species exhibited a lower variable: maximum fluorescence (F v :F m ) when cuvettes were exposed to solar radiation during the 30-minute dark adaptation than when cuvettes were shielded. In a third study with S. mahagoni, the influence of self-shielding the cuvettes by wrapping them with white tape, white paper, or aluminum foil on temperature and fluorescence was compared to exposing or shielding the entire leaflet and cuvette. All of the shielding methods reduced leaflet temperature and increased the F v :F m ratio compared to leaving cuvettes exposed. These results indicate that heat stress from direct exposure to solar radiation is a potential source of error when interpreting chlorophyll fluorescence measurements on intact leaves. Methods for moderating or minimizing radiation interception during dark adaptation are recommended. (author)

  13. How calibration and reference spectra affect the accuracy of absolute soft X-ray solar irradiance measured by the SDO/EVE/ESP during high solar activity

    Science.gov (United States)

    Didkovsky, Leonid; Wieman, Seth; Woods, Thomas

    2016-10-01

    The Extreme ultraviolet Spectrophotometer (ESP), one of the channels of SDO's Extreme ultraviolet Variability Experiment (EVE), measures solar irradiance in several EUV and soft x-ray (SXR) bands isolated using thin-film filters and a transmission diffraction grating, and includes a quad-diode detector positioned at the grating zeroth-order to observe in a wavelength band from about 0.1 to 7.0 nm. The quad diode signal also includes some contribution from shorter wavelength in the grating's first-order and the ratio of zeroth-order to first-order signal depends on both source geometry, and spectral distribution. For example, radiometric calibration of the ESP zeroth-order at the NIST SURF BL-2 with a near-parallel beam provides a different zeroth-to-first-order ratio than modeled for solar observations. The relative influence of "uncalibrated" first-order irradiance during solar observations is a function of the solar spectral irradiance and the locations of large Active Regions or solar flares. We discuss how the "uncalibrated" first-order "solar" component and the use of variable solar reference spectra affect determination of absolute SXR irradiance which currently may be significantly overestimated during high solar activity.

  14. On-Orbit Measurement of Next Generation Space Solar Cell Technology on the International Space Station

    Science.gov (United States)

    Wolford, David S.; Myers, Matthew G.; Prokop, Norman F.; Krasowski, Michael J.; Parker, David S.; Cassidy, Justin C.; Davies, William E.; Vorreiter, Janelle O.; Piszczor, Michael F.; McNatt, Jeremiah S.

    2015-01-01

    Measurement is essential for the evaluation of new photovoltaic (PV) technology for space solar cells. NASA Glenn Research Center (GRC) is in the process of measuring several solar cells in a supplemental experiment on NASA Goddard Space Flight Center's (GSFC) Robotic Refueling Mission's (RRM) Task Board 4 (TB4). Four industry and government partners have provided advanced PV devices for measurement and orbital environment testing. The experiment will be on-orbit for approximately 18 months. It is completely self-contained and will provide its own power and internal data storage. Several new cell technologies including four- junction (4J) Inverted Metamorphic Multijunction (IMM) cells will be evaluated and the results compared to ground-based measurements.

  15. The enerMENA meteorological network - Solar radiation measurements in the MENA region

    Science.gov (United States)

    Schüler, D.; Wilbert, S.; Geuder, N.; Affolter, R.; Wolfertstetter, F.; Prahl, C.; Röger, M.; Schroedter-Homscheidt, M.; Abdellatif, G.; Guizani, A. Allah; Balghouthi, M.; Khalil, A.; Mezrhab, A.; Al-Salaymeh, A.; Yassaa, N.; Chellali, F.; Draou, D.; Blanc, P.; Dubranna, J.; Sabry, O. M. K.

    2016-05-01

    For solar resource assessment of solar power plants and adjustment of satellite data, high accuracy measurement data of irradiance and ancillary meteorological data is needed. For the MENA region (Middle East and Northern Africa), which is of high importance for concentrating solar power applications, so far merely 2 publicly available ground measurement stations existed (BSRN network). This gap has been filled by ten stations in Morocco, Algeria, Tunisia, Egypt and Jordan. In this publication the data quality is analyzed by evaluating data completeness and the cleanliness of irradiance sensors in comparison for all of the stations. The pyrheliometers have an average cleanliness of 99.2 % for week-daily cleaning. This is a 5 times higher effort than for Rotating Shadowband Irradiometer (RSI) stations which even have a slightly higher average cleanliness of 99.3 % for weekly cleaning. Furthermore, RSI stations show a data completeness of 99.4 % compared to 93.6 % at the stations equipped with thermal sensors. The results of this analysis are used to derive conclusions concerning instrument choice and are hence also applicable to other solar radiation measurements outside the enerMENA network. It turns out that RSIs are the more reliable and robust choice in cases of high soiling, rare station visits for cleaning and maintenance, as usual in desert sites. Furthermore, annual direct normal and global horizontal irradiation as well as average meteorological parameters are calculated for all of the stations.

  16. Measurement of solar ultraviolet radiation intensity type A and B in Qazvin (2013-14

    Directory of Open Access Journals (Sweden)

    SAR. Babaee

    2016-08-01

    Full Text Available Background: Solar ultraviolet radiation (UVR is considered one of the most important biological risk factors in the world. Most health damages from solar ultraviolet radiation at ground level are mainly caused by UVA and UVB spectrums. Objective: The aim of this study was to Measure the solar ultraviolet radiation intensity type A and B in Qazvin city. Methods: In this cross-sectional study, the intensity of solar ultraviolet radiation type A and B was measured in Qazvin on years of 2013-14 (during one year every monthly at three times, in the morning, afternoon and evening by using a UV Radiometer. Data were analyzed using descriptive statistics. Findings: The maximum average intensity of UVA and UVB rays during the one year with 28.36±1.88 W/m2 and 0.156±0.035 W/m2 respectively was in Tir month (June 22–July 22 and the minimum average intensity of UVA and UVB rays with 10.36±0.83 W/m2 and 0.041±0.010 W/m2 respectively was in Dai month (December 22–January 20. Conclusion: With regards to the results, it is recommended that individuals were less exposed to exposure time with direct sunshine and use appropriate protective measures such as; wear appropriate clothing, sunglasses, and sunscreen.

  17. Spectroscopic factors measurements in the s,d and f,p shells below and above the Coulomb barrier by (3He,d) reactions

    International Nuclear Information System (INIS)

    Baghdadi, Ahmed.

    1974-01-01

    The overlap of t and d or 3 He and d wave functions may be measured by one neutron transfer in (d,t) or one proton transfer in ( 3 He,d). The measurement of the resulting normalization constant has been performed in subcoulombic conditions in the case of 58 Ni( 3 He,d) 59 Cu and 60 Ni( 3 He,d) 61 Cu leading to the first 3/2 - and 1/2 - states with a position sensitive detector in a Buechner spectrograph. The result: D 2 =2.7+-0.2 10 4 MeV 2 fm 3 is in agreement with the D 2 measurement for (t,d) reactions [3.1+-0.2 10 4 MeV 2 fm 3 ] and with the theoretical value proposed by L.J.B. Goldfarg and coworkers. This result was used for a determination of the spectroscopic factors of the 1.379MeV 3/2 - state, the 1.507MeV 1/2 - state and the 1.758MeV 3/2 - state in 57 Co. The subcoulombic approximation is also shown to be valid even in the case of (d,p) reactions, by the measurement of angular distributions and excitation curves of 60 Ni(d,p) reactions leading to the excited states at 4.760MeV (l=2) and 4.907MeV (l=0). In the second part, some spectroscopic factors in the s-d shell were measured by ( 3 He,d) reactions at MP Tandem energies. In the case of 27 Al( 3 He,d) 28 Si (states at 4.62, 6.88, 6.89, 9.32 and 0.38MeV) the normalization constant D 0 2 (deduced from the subcoulombic D 2 value) together with the first order finite range approximation leads to spectroscopic factors in good agreement with Wildenthal theoretical results. For 28 Si( 3 He,d) 29 p however, the values are too high compared to 29 Si. The conclusion is that it is better to use the DWBA treatment at subcoulombic energies everytime the experimental conditions may be fulfilled [fr

  18. Solar Radiation and Cloud Radiative Forcing in the Pacific Warm Pool Estimated Using TOGA COARE Measurements

    Science.gov (United States)

    Chou, Ming-Dah; Chou, Shu-Hsien; Zhao, Wenzhong

    1999-01-01

    The energy budget of the tropical western Pacific (TWP) is particularly important because this is one of the most energetic convection regions on the Earth. Nearly half of the solar radiation incident at the top of atmosphere is absorbed at the surface and only about 22% absorbed in the atmosphere. A large portion of the excess heat absorbed at the surface is transferred to the atmosphere through evaporation, which provides energy and water for convection and precipitation. The western equatorial Pacific is characterized by the highest sea surface temperature (SST) and heaviest rainfall in the world ocean. A small variation of SST associated with the eastward shift of the warm pool during El-Nino/Souther Oscillation changes the atmospheric circulation pattern and affects the global climate. In a study of the TWP surface heat and momentum fluxes during the Tropical Ocean and Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) Intensive observing period (IOP) from November 1992 to February have found that the solar radiation is the most important component of the surface energy budget, which undergoes significant temporal and spatial variation. The variations are influenced by the two 40-50 days Madden Julian Oscillations (MJOs) which propagated eastward from the Indian Ocean to the Central Pacific during the IOP. The TWP surface solar radiation during the COARE IOP was investigated by a number of studies. In addition, the effects of clouds on the solar heating of the atmosphere in the TWP was studied using energy budget analysis. In this study, we present some results of the TWP surface solar shortwave or SW radiation budget and the effect of clouds on the atmospheric solar heating using the surface radiation measurements and Japan's Geostationary Meteorological Satellite 4 radiance measurements during COARE IOP.

  19. Effective aerosol optical depth from pyranometer measurements of surface solar radiation (global radiation) at Thessaloniki, Greece

    OpenAIRE

    Lindfors, A. V.; Kouremeti, N.; Arola, A.; Kazadzis, S.; Bais, A. F.; Laaksonen, A.

    2013-01-01

    Pyranometer measurements of the solar surface radiation (SSR) are available at many locations worldwide, often as long time series covering several decades into the past. These data constitute a potential source of information on the atmospheric aerosol load. Here, we present a method for estimating the aerosol optical depth (AOD) using pyranometer measurements of the SSR together with total water vapor column information. The method, which is based on radiative transfer simulations, w...

  20. AFM measurements of novel solar cells. Studying electronic properties of Si-based radial junctions

    Czech Academy of Sciences Publication Activity Database

    Hývl, Matěj

    -, č. 1 (2014), s. 52-53 ISSN 1439-4243 R&D Projects: GA ČR GA13-25747S; GA ČR GA13-12386S; GA MŠk(CZ) LM2011026 Institutional support: RVO:68378271 Keywords : AFM measurements * conductive cantilever * electronic properties * nanowires * PF TUNA Subject RIV: BM - Solid Matter Physics ; Magnetism http://www.imaging-git.com/science/scanning-probe-microscopy/afm-measurements-novel-solar- cells

  1. SYSTEMATIC UNCERTAINTIES IN THE SPECTROSCOPIC MEASUREMENTS OF NEUTRON STAR MASSES AND RADII FROM THERMONUCLEAR X-RAY BURSTS. III. ABSOLUTE FLUX CALIBRATION

    Energy Technology Data Exchange (ETDEWEB)

    Güver, Tolga [Istanbul University, Science Faculty, Department of Astronomy and Space Sciences, Beyazıt, 34119, Istanbul (Turkey); Özel, Feryal; Psaltis, Dimitrios [Department of Astronomy, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Marshall, Herman [Center for Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Guainazzi, Matteo [European Space Astronomy Centre of ESA, P.O. Box 78, Villanueva de la Cañada, E-28691 Madrid (Spain); Díaz-Trigo, Maria [ESO, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München (Germany)

    2016-09-20

    Many techniques for measuring neutron star radii rely on absolute flux measurements in the X-rays. As a result, one of the fundamental uncertainties in these spectroscopic measurements arises from the absolute flux calibrations of the detectors being used. Using the stable X-ray burster, GS 1826–238, and its simultaneous observations by Chandra HETG/ACIS-S and RXTE /PCA as well as by XMM-Newton EPIC-pn and RXTE /PCA, we quantify the degree of uncertainty in the flux calibration by assessing the differences between the measured fluxes during bursts. We find that the RXTE /PCA and the Chandra gratings measurements agree with each other within their formal uncertainties, increasing our confidence in these flux measurements. In contrast, XMM-Newton EPIC-pn measures 14.0 ± 0.3% less flux than the RXTE /PCA. This is consistent with the previously reported discrepancy with the flux measurements of EPIC-pn, compared with EPIC MOS1, MOS2, and ACIS-S detectors. We also show that any intrinsic time-dependent systematic uncertainty that may exist in the calibration of the satellites has already been implicity taken into account in the neutron star radius measurements.

  2. A STUDY OF SOLAR PHOTOSPHERIC TEMPERATURE GRADIENT VARIATION USING LIMB DARKENING MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Criscuoli, Serena [National Solar Observatory, Boulder, CO 80303 (United States); Foukal, Peter [192 Willow Road, Nahant, MA 01908 (United States)

    2017-01-20

    The variation in area of quiet magnetic network measured over the sunspot cycle should modulate the spatially averaged photospheric temperature gradient, since temperature declines with optical depth more gradually in magnetic flux tube atmospheres. Yet, limb darkening measurements show no dependence upon activity level, even at an rms precision of 0.04%. We study the sensitivity of limb darkening to changes in area filling factor using a 3D MHD model of the magnetized photosphere. The limb darkening change expected from the measured 11-year area variation lies below the level of measured limb darkening variations, for a reasonable range of magnetic flux in quiet network and internetwork regions. So the remarkably constant limb darkening observed over the solar activity cycle is not inconsistent with the measured 11-year change in area of quiet magnetic network. Our findings offer an independent constraint on photospheric temperature gradient changes reported from measurements of the solar spectral irradiance from the Spectral Irradiance Monitor, and recently, from wavelength-differential spectrophotometry using the Solar Optical Telescope aboard the HINODE spacecraft.

  3. A method to calibrate a solar pyranometer for measuring reference diffuse irradiance

    Energy Technology Data Exchange (ETDEWEB)

    Reda, I.; Stoffel, T.; Myers, D. [National Renewable Energy Laboratory, Golden, CO (United States)

    2003-02-01

    Accurate pyranometer calibrations, traceable to internationally recognized standards, are critical for solar irradiance measurements. One calibration method is the component summation, where the pyranometers are calibrated outdoors under clear sky conditions, and the reference global solar irradiance is calculated as the sum of two reference components, the diffuse and subtended beam solar irradiances. The beam component is measured with pyrheliometers traceable to the World Radiometric Reference, while there is no internationally recognized reference for the diffuse component. In the absence of such a reference, we present a method to consistently calibrate pyranometers for measuring the diffuse component with an estimated uncertainty of {+-} (3% of reading +1 W/m{sup 2}). The method is based on using a modified shade/unshade method, and pyranometers with less than 1 W/m{sup 2} thermal offset errors. We evaluated the consistency of our method by calibrating three pyranometers four times. Calibration results show that the responsivity change is within {+-} 0.52% for the three pyranometers. We also evaluated the effect of calibrating pyranometers unshaded, then using them shaded to measure diffuse irradiance. We calibrated three unshaded pyranometers using the component summation method. Their outdoor measurements of clear sky diffuse irradiance, from sunrise to sundown, showed that the three calibrated pyranometers can be used to measure the diffuse irradiance to within {+-} 1.4 W/m{sup 2} variation from the reference irradiance. (author)

  4. Development of tool for optimization in the measurement of solar radiation; Desarrollo de herramientas para la optimizacion en la medicion de la radiacion solar

    Energy Technology Data Exchange (ETDEWEB)

    Adaro, J.; Quiroga, D.; Fasulo, A.; Lema, A.

    2004-07-01

    One of the most important requirements to make a project of rational use of solar energy is the precise knowledge of the temporal-spatial distribution of the solar resource on the terrestrial surface. For that reason, the Solar Energy Group at the National University of Rio Cuarto in Argentina, is measuring and recording data of global and direct solar radiation. Many possibilities of different kinds of errors there exist in this process, but the most significant problem is the lack of data. Then, it would be necessary to have a methodology that indicates what to do in this situation, and for that reason, this work performs an study about the data processing of the obtained measurements to infer values to be incorporated to the series in situations where the data are lost. To incorporate lost data, the Time Series Analysis based in spatial state models were used. (Author)

  5. Comparative Study of foF2 Measurements with IRI-2007 Model Predictions During Extended Solar Minimum

    Science.gov (United States)

    Zakharenkova, I. E.; Krankowski, A.; Bilitza, D.; Cherniak, Iu.V.; Shagimuratov, I.I.; Sieradzki, R.

    2013-01-01

    The unusually deep and extended solar minimum of cycle 2324 made it very difficult to predict the solar indices 1 or 2 years into the future. Most of the predictions were proven wrong by the actual observed indices. IRI gets its solar, magnetic, and ionospheric indices from an indices file that is updated twice a year. In recent years, due to the unusual solar minimum, predictions had to be corrected downward with every new indices update. In this paper we analyse how much the uncertainties in the predictability of solar activity indices affect the IRI outcome and how the IRI values calculated with predicted and observed indices compared to the actual measurements.Monthly median values of F2 layer critical frequency (foF2) derived from the ionosonde measurements at the mid-latitude ionospheric station Juliusruh were compared with the International Reference Ionosphere (IRI-2007) model predictions. The analysis found that IRIprovides reliable results that compare well with actual measurements, when the definite (observed and adjusted) indices of solar activityare used, while IRI values based on earlier predictions of these indices noticeably overestimated the measurements during the solar minimum.One of the principal objectives of this paper is to direct attention of IRI users to update their solar activity indices files regularly.Use of an older index file can lead to serious IRI overestimations of F-region electron density during the recent extended solar minimum.

  6. Computer based system for measuring the minority carrier lifetime in the solar cells

    International Nuclear Information System (INIS)

    Morales A, A.; Casados C, G.

    1994-01-01

    We show the development of a computer based system for measuring the minority carrier lifetime in the base of silicon solar cells. The system allows using two different techniques for such kind of measurements:the open circuit voltage decay (OCVD) and the surface voltage decay SVD. The equipment is based on internal cards for IBM-Pc or compatible computers that work as an oscilloscope and as a function generator, in addition to a synchronization and signal conditioning circuit. The system is fully controlled by a 'c' language program that optimizes the used of the instrument built in this way, and makes the analysis of the measurement data by curve fitting techniques. We show typical results obtained with silicon solar cells made in our laboratories. (Author)

  7. Measurement of Global Solar Radiation data using Raspberry Pi and its estimation using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Priya S.Shanmuga

    2018-01-01

    Full Text Available The demand for more efficient and environmentally benign, non-conventional sources of energy came into picture due to increasing demands for human comforts. Solar energy is now the ultimate option. In this paper, the instruments used to measure the solar radiation at Innovation Centre, MIT Manipal were connected to a Raspberry Pi to access the data remotely. Genetic Algorithms were formulated, so that the monthly mean global solar radiation in Manipal can be effectively estimated. Meteorological data such as humidity, temperature, wind speed, etc. were used as inputs to train the networks. A successful network was made between the data loggers and the Raspberry Pi. The data collected by the data loggers from the devices are transmitted to the Raspberry Pi which in turn sends the data to an internal server. The Raspberry Pi can be accessed using any SSH client such as PuTTY. The meteorological data was collected for the years 2010-2014 in order to formulate the Artificial Intelligence models. The validity of the formulated models were checked by comparing the measured data with the estimated data using tools such as RMSE, correlation coefficient, etc. The modelling of solar radiation using GA was carried out in GeneXpro tools version 5.0.

  8. Rocket borne solar eclipse experiment to measure the temperature structure of the solar corona via lyman-α line profile observations

    International Nuclear Information System (INIS)

    Argo, H.V.

    1981-01-01

    A rocket borne experiment to measure the temperature structure of the inner solar corona via the doppler broadening of the resonance hydrogen Lyman-α (lambda1216A) radiation scattered by ambient neutral hydrogen atoms was attempted during the 16 Feb 1980 solar eclipse. Two Nike-Black Brant V sounding rockets carrying instrumented payloads were launched into the path of the advancing eclipse umbra from the San Marco satellite launch platform 3 miles off the east coast of Kenya

  9. Real-time measurement of outdoor worker's exposure to solar ultraviolet radiation in Pretoria, South Africa

    Directory of Open Access Journals (Sweden)

    Mmathapelo Makgabutlane

    2015-05-01

    Full Text Available The city of Pretoria in South Africa receives considerable solar ultraviolet radiation (UVR because of its low latitude (22–35°S and relatively clear skies. Certain meteorological factors affect the amount of solar UVR that reaches the ground; the most dominant factors being stratospheric ozone, cloud cover and solar zenith angle. It is known that overexposure to solar UVR may lead to the development of adverse health conditions, the most significant being skin cancer. Outdoor workers spend a significant amount of time outside and are thus susceptible to this risk. In this case study, we estimated, for the first time, the real-time solar UVR exposure of an outdoor worker in Pretoria. Measurements were made on 27 and 28 May 2013 using a handheld ultraviolet index (UVI meter calibrated against a science-grade biometer at the South African Weather Service in Pretoria. Personal exposure estimation was used to discern the pattern in diurnal and annual sunburn risk for the outdoor worker. Ambient UVR levels ranged from 0 UVI to 4.66 UVI and the outdoor worker’s potential exposure estimates regularly exceeded 80% of these levels depending on the time of day. The risk of sunburn was evident; however, actual incidents would depend on individual skin photosensitivity and melanin content, as well as sun protection used. Further research is needed to determine the personal exposure estimations of outdoor workers in other provinces in which solar UVR levels may be equally high, or higher than those in Pretoria.

  10. Spectroscopic enhancement in nanoparticles embedded glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sahar, M. R., E-mail: mrahim057@gmail.com; Ghoshal, S. K., E-mail: mrahim057@gmail.com [Advanced Optical Material Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor Bahru, Johor (Malaysia)

    2014-09-25

    This presentation provides an overview of the recent progress in the enhancement of the spectroscopic characteristics of the glass embedded with nanoparticles (NPs). Some of our research activities with few significantly new results are highlighted and facilely analyzed. The science and technology dealing with the manipulation of the physical properties of rare earth doped inorganic glasses by embedding metallic NPs or nanoclusters produce the so-called 'nanoglass'. Meanwhile, the spectroscopic enhancement relates the intensity of the luminescence measured at certain transition. The enhancement which expectedly due to the 'plasmonics wave' (referring to the coherent coupling of photons to free electron oscillations called plasmon) occurs at the interface between a conductor and a dielectric. Plasmonics being an emerging concept in advanced optical material of nanophotonics has given this material the ability to exploit the optical response at nanoscale and opened up a new avenue in metal-based glass optics. There is a vast array of plasmonic NPs concepts yet to be explored, with applications spanning solar cells, (bio) sensing, communications, lasers, solid-state lighting, waveguides, imaging, optical data transfer, display and even bio-medicine. Localized surface plasmon resonance (LSPR) can enhance the optical response of nanoglass by orders of magnitude as observed. The luminescence enhancement and surface enhanced Raman scattering (SERS) are new paradigm of research. The enhancement of luminescence due to the influence of metallic NPs is the recurring theme of this paper.

  11. Precision measurement of the 7Be solar neutrino rate and absence of day-night asymmetry in Borexino

    International Nuclear Information System (INIS)

    Davini, S.

    2011-01-01

    Borexino, in data taking since May 2007, is the only experiment capable to perform the measurement of low-energy solar-ν. Borexino has performed the first direct measurement of the 7 Be solar-ν rate with accuracy better than 5%. The absence of day-night asymmetry of the 7 Be solar-ν rate was measured with a total uncertainty of 1%. Borexino results alone reject the Low Δm 2 (LOW) region of solar-ν oscillation parameters at more than 8.5 σ CL. Combined with the other solar-ν data, Borexino measurements isolate the Large Mixing Angle (LMA)- Mikheyev Smirnov Wolfenstein (MSW) solution of neutrino oscillations without assuming CPT invariance in the neutrino sector.

  12. Measurement of the solar neutrino capture rate with gallium metal, part III

    International Nuclear Information System (INIS)

    Elliott, Steven Ray

    2008-01-01

    The Russian-American experiment SAGE began to measure the solar neutrino capture rate with a target of gallium metal in December 1989. Measurements have continued with only a few brief interruptions since that time. In this article we present the experimental improvements in SAGE since its last published data summary in December 2001. Assuming the solar neutrino production rate was constant during the period of data collection, combined analysis of 168 extractions through December 2007 gives a capture rate of solar neutrinos with energy more than 233 keY of 65.4 +3.1 3.0 (stat) +2.6 -2.8 (syst) SNU. The weighted average of the results of all three Ga solar neUlrino experiments, SAGE, Gallex, and GNO, is now 66.1 ± 3.1 SNU, where statistical and systematic uncertainties have been combined in quadrature. During the recent period of data collection a new test of SAGE was made with a reactor-produced 37 Ar neutrino source. The ratio of observed to calculated rates in this experiment, combined with the measured rates in the three prior 51 Cr neutrino-source experiments with Ga, is 0.88 ± 0.05. A probable explanation for this low result is that the cross section for neutrino capture by the two lowest-lying excited states in 71 Ge has been overestimated. If we assume these cross sections are zero, then the standard solar model including neutrino oscillations predicts a total capture rate in Ga in the range of 63--67 SNU with an uncertainly of about 5%, in good agreement with experiment. We derive the current value of the pp neutrino flux produced in the Sun to be φ · pp = (6.1 ± 0.8) x 10 10 /(cm 2 s), which agrees well with the flux predicted by the standard solar model. Finally, we make several tests and show that the data are consistent with the assumption that the solar neutrino production rate is constant in time.

  13. Raman Spectroscopic Studies of Methane Gas Hydrates

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.

    2009-01-01

    A brief review of the Raman spectroscopic studies of methane gas hydrates is given, supported by some new measurements done in our laboratory.......A brief review of the Raman spectroscopic studies of methane gas hydrates is given, supported by some new measurements done in our laboratory....

  14. A Raman scattering and FT-IR spectroscopic study on the effect of the solar radiation in Antarctica on bovine cornea

    Science.gov (United States)

    Yamamoto, Tatsuyuki; Murakami, Naoki; Yoshikiyo, Keisuke; Takahashi, Tetsuya; Yamamoto, Naoyuki

    2010-01-01

    The Raman scattering and FT-IR spectra of the corneas, transported to the Syowa station in Antarctica and exposed to the solar radiation of the mid-summer for four weeks, were studied to reveal that type IV collagen involved in corneas were fragmented. The amide I and III Raman bands were observed at 1660 and 1245 cm -1, respectively, and the amide I and II infrared bands were observed at 1655 and 1545 cm -1, respectively, for original corneas before exposure. The background of Raman signals prominently increased and the ratio of amide II infrared band versus amide I decreased by the solar radiation in Antarctica. The control experiment using an artificial UV lamp was also performed in laboratory. The decline rate of the amide II/amide I was utilized for estimating the degree of fragmentation of collagen, to reveal that the addition of vitamin C suppressed the reaction while the addition of sugars promoted it. The effect of the solar radiation in Antarctica on the corneas was estimated as the same as the artificial UV lamp of four weeks (Raman) or one week (FT-IR) exposure.

  15. Surface net solar radiation estimated from satellite measurements - Comparisons with tower observations

    Science.gov (United States)

    Li, Zhanqing; Leighton, H. G.; Cess, Robert D.

    1993-01-01

    A parameterization that relates the reflected solar flux at the top of the atmosphere to the net solar flux at the surface in terms of only the column water vapor amount and the solar zenith angle was tested against surface observations. Net surface fluxes deduced from coincidental collocated satellite-measured radiances and from measurements from towers in Boulder during summer and near Saskatoon in winter have mean differences of about 2 W/sq m, regardless of whether the sky is clear or cloudy. Furthermore, comparisons between the net fluxes deduced from the parameterization and from surface measurements showed equally good agreement when the data were partitioned into morning and afternoon observations. This is in contrast to results from an empirical clear-sky algorithm that is unable to account adequately for the effects of clouds and that shows, at Boulder, a distinct morning to afternoon variation. It is also demonstrated that the parameterization may be applied to irradiances at the top of the atmosphere that have been temporally averaged. The good agreement between the results of the parameterization and surface measurements suggests that the algorithm is a useful tool for a variety of climate studies.

  16. SOLAR WAVE-FIELD SIMULATION FOR TESTING PROSPECTS OF HELIOSEISMIC MEASUREMENTS OF DEEP MERIDIONAL FLOWS

    International Nuclear Information System (INIS)

    Hartlep, T.; Zhao, J.; Kosovichev, A. G.; Mansour, N. N.

    2013-01-01

    The meridional flow in the Sun is an axisymmetric flow that is generally directed poleward at the surface, and is presumed to be of fundamental importance in the generation and transport of magnetic fields. Its true shape and strength, however, are debated. We present a numerical simulation of helioseismic wave propagation in the whole solar interior in the presence of a prescribed, stationary, single-cell, deep meridional circulation serving as synthetic data for helioseismic measurement techniques. A deep-focusing time-distance helioseismology technique is applied to the synthetic data, showing that it can in fact be used to measure the effects of the meridional flow very deep in the solar convection zone. It is shown that the ray approximation that is commonly used for interpretation of helioseismology measurements remains a reasonable approximation even for very long distances between 12° and 42° corresponding to depths between 52 and 195 Mm. From the measurement noise, we extrapolate that time-resolved observations on the order of a full solar cycle may be needed to probe the flow all the way to the base of the convection zone.

  17. Measurements of Solar Ultraviolet Radiation Exposure at Work and at Leisure in Danish Workers.

    Science.gov (United States)

    Grandahl, Kasper; Eriksen, Paul; Ibler, Kristina Sophie; Bonde, Jens Peter; Mortensen, Ole Steen

    2018-03-30

    Exposure to solar ultraviolet radiation is the main cause of skin cancer and may well present an occupational health and safety problem. In Denmark, skin cancer is a common disease in the general population, but detailed data on solar ultraviolet radiation exposure among outdoor workers are lacking. The aim of this study was to provide objective measurements of solar ultraviolet radiation exposure on working days and at leisure and compare levels of exposure between groups of mainly outdoor, equal-parts-outdoor-and-indoor and indoor workers. To this end, UV-B dosimeters with an aluminum gallium nitride (AlGaN) photodiode detector were used to measure the solar ultraviolet radiation exposure of 457 workers in the Danish summer season. Presented as semi-annual standard erythemal dose (SED) on working days, respectively, at leisure, the results are for mainly outdoor workers 214.2 SED and 64.8 SED, equal-parts-outdoor-and-indoor workers 131.4 SED and 64.8 SED, indoor workers 55.8 SED and 57.6 SED. The daily SED by month is significantly different (α = 0.05) between mainly outdoor, equal-parts-outdoor-and-indoor and indoor workers and across professional groups; some of which are exposed at very high levels that is roofers 361.8 SED. These findings substantiate that exposure to solar ultraviolet radiation is indeed an occupational health and safety problem in Denmark. © 2018 The Authors. Photochemistry and Photobiology published by Wiley Periodicals, Inc. on behalf of American Society for Photobiology.

  18. Uniform and non-uniform modes of nanosecond-pulsed dielectric barrier discharge in atmospheric air: fast imaging and spectroscopic measurements of electric fields

    International Nuclear Information System (INIS)

    Liu, Chong; Dobrynin, Danil; Fridman, Alexander

    2014-01-01

    In this study, we report experimental results on fast intensified charge-coupled device (ICCD) imaging of the development of nanosecond-pulsed dielectric barrier discharge (DBD) in atmospheric air and spectroscopic measurements of the electric field in the discharge. The uniformity of the discharge images obtained with nanosecond exposure times was analysed using chi-square test. The results indicate that DBD uniformity strongly depends on the applied (global) electric field in the discharge gap, which is a threshold phenomenon. We show that in the case of strong overvoltage on the discharge gap (provided by fast rise times), there is a transition from filamentary to uniform DBD mode that correlates to the corresponding decrease of the maximum local electric field in the discharge. (fast track communication)

  19. Uniform and non-uniform modes of nanosecond-pulsed dielectric barrier discharge in atmospheric air: fast imaging and spectroscopic measurements of electric field

    Science.gov (United States)

    Liu, Chong; Dobrynin, Danil; Fridman, Alexander

    2014-01-01

    In this study, we report experimental results on fast ICCD imaging of development of nanosecond-pulsed dielectric barrier discharge (DBD) in atmospheric air and spectroscopic measurements of electric field in the discharge. Uniformity of the discharge images obtained with nanosecond exposure times were analyzed using chi-square test. The results indicate that DBD uniformity strongly depends on applied (global) electric field in the discharge gap, and is a threshold phenomenon. We show that in the case of strong overvoltage on the discharge gap (provided by fast rise times), there is transition from filamentary to uniform DBD mode which correlates to the corresponding decrease of maximum local electric field in the discharge. PMID:25071294

  20. Solar UV exposure among outdoor workers in Denmark measured with personal UV-B dosimeters

    DEFF Research Database (Denmark)

    Grandahl, Kasper; Mortensen, Ole Steen; Sherman, David Zim

    2017-01-01

    radiation exposure are needed to help resolve this problem. This can be done using personal ultraviolet radiation dosimeters. Methods: We consider technical and practical feasibility of measuring individual solar ultraviolet exposure at work and leisure in professions with different á priori temporal high......-level outdoor worktime, using aluminium gallium nitride (AlGaN) photodiode detector based personal UV-B dosimeters. Essential technical specifications including the spectral and angular responsivity of the dosimeters are described and pre-campaign dosimeter calibration applicability is verified. The scale...... with our specialist knowledge as occupational physicians. Conclusions: Large-scale use of personal UV-B dosimeters for measurement of solar ultraviolet radiation exposure at work and leisure in Denmark is indeed feasible from a technical and practical viewpoint. Samples of exposure data shown support...

  1. XCO2-measurements with a tabletop FTS using solar absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    A. Simon

    2012-11-01

    Full Text Available A commercial low-resolution (0.5 cm−1 Fourier Transform Spectrometer (FTS has been modified and is used for determining the total column XCO2 of the atmosphere by analysing direct solar radiation. The spectrometer has a small home-built solar tracker attached, so that it is a ready-to-use instrument. The results are validated with temporally coinciding on-site measurements taken with a high-resolution Total Carbon Column Observing Network (TCCON FTIR spectrometer. For the whole comparison period of 5 months (26 measurement days an agreement with TCCON results of (0.12 ± 0.08% is achieved. This makes the spectrometer a promising candidate for a low-cost addition to the TCCON core FTIR sites, especially suitable for locations with limited infrastructure. An impressive mechanical and thermal stability is proved, enabling the spectrometer for use in field campaigns and for the monitoring of local sources.

  2. Heat transfer analysis in a calorimeter for concentrated solar radiation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, C.A.; Jaramillo, O.A.; Arancibia-Bulnes, C.A. [Universidad Nacional Autonoma de Mexico, Centro de Investigacion en Energia, Privada Xochicalco S/N, Col. Centro. Temixco, Morelos 62580 (Mexico); Acosta, R. [Universidad de Quintana Roo, Boulevard Bahia s/n Esq. I. Comonfort, Chetumal Quintana Roo 77019 (Mexico)

    2007-10-15

    A calorimeter was built for measuring the concentrated solar power produced by a point focus solar concentrator that was developed at CIE - UNAM. In order to obtain a thermal characterization of the calorimeter a theoretical and experimental heat transfer study is carried out. This study addresses the heat transfer in the circular flat plate of the calorimeter, which acts as receiver for the concentrating system. Temperatures are measured at different points of this plate and fit with a theoretical model that considers heat conduction with convective and radiative boundary conditions. In particular, it is possible to calculate the temperature distribution on the irradiated surface. This allows to examine the validity of the assumptions of cold water calorimetry, which was the technique applied to this system in previous works. (author)

  3. A home-made system for IPCE measurement of standard and dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Palma, Giuseppina; Cozzarini, Luca; Capria, Ennio [Organic OptoElectronics Laboratory, Sincrotrone Trieste SCpA—SS 14.5, km 163.5, 34149 Basovizza (TS) (Italy); Fraleoni-Morgera, Alessandro, E-mail: alessandro.fraleoni@elettra.trieste.it, E-mail: afraleoni@units.it [Organic OptoElectronics Laboratory, Sincrotrone Trieste SCpA—SS 14.5, km 163.5, 34149 Basovizza (TS) (Italy); Flextronics Laboratory, Department of Engineering and Architecture, University of Trieste. V. Valerio 10, 34100 Trieste (TS) (Italy)

    2015-01-15

    A home-made system for incident photon-to-electron conversion efficiency (IPCE) characterization, based on a double-beam UV-Vis spectrophotometer, has been set up. In addition to its low cost (compared to the commercially available apparatuses), the double-beam configuration gives the advantage to measure, autonomously and with no need for supplementary equipment, the lamp power in real time, compensating possible variations of the spectral emission intensity and quality, thus reducing measurement times. To manage the optical and electronic components of the system, a custom software has been developed. Validations carried out on a common silicon-based photodiode and on a dye-sensitized solar cell confirm the possibility to adopt this system for determining the IPCE of solar cells, including dye-sensitized ones.

  4. A home-made system for IPCE measurement of standard and dye-sensitized solar cells.

    Science.gov (United States)

    Palma, Giuseppina; Cozzarini, Luca; Capria, Ennio; Fraleoni-Morgera, Alessandro

    2015-01-01

    A home-made system for incident photon-to-electron conversion efficiency (IPCE) characterization, based on a double-beam UV-Vis spectrophotometer, has been set up. In addition to its low cost (compared to the commercially available apparatuses), the double-beam configuration gives the advantage to measure, autonomously and with no need for supplementary equipment, the lamp power in real time, compensating possible variations of the spectral emission intensity and quality, thus reducing measurement times. To manage the optical and electronic components of the system, a custom software has been developed. Validations carried out on a common silicon-based photodiode and on a dye-sensitized solar cell confirm the possibility to adopt this system for determining the IPCE of solar cells, including dye-sensitized ones.

  5. Measurements of the solar UVR protection provided by shade structures in New Zealand primary schools.

    Science.gov (United States)

    Gies, Peter; Mackay, Christina

    2004-01-01

    To reduce ultraviolet radiation (UVR) exposure during childhood, shade structures are being erected in primary schools to provide areas where children can more safely undertake outdoor activities. This study to evaluate the effectiveness of existing and purpose built shade structures in providing solar UVR protection was carried out on 29 such structures in 10 schools in New Zealand. Measurements of the direct and scattered solar UVR doses within the central region of the shade structures were made during the school lunch break period using UVR-sensitive polysulfone film badges. These measurements indicate that many of the structures had UVR protection factors (PF) of 4-8, which was sufficient to provide protection during the school lunch hour. However, of the 29 structures examined, only six would meet the suggested requirements of UVR PF greater than 15 required to provide all-day protection.

  6. Measurement of 7Be and 8B solar neutrinos with Borexino

    International Nuclear Information System (INIS)

    Zavatarelli, S.; Bellini, G.; Bonetti, S.; Buizza-Avanzini, M.; Caccianiga, B.

    2009-01-01

    Borexino is a real-time liquid-scintillator detector for low-energy neutrino spectroscopy located at the Gran Sasso National Laboratories (Italy). Thanks to the unprecedented radio purity of the target mass it is providing the first direct and simultaneous measurements of the solar neutrino survival probability in both vacuum-dominated (7 B e ν) and matter-enhanced regions (8 B ν) by a single experiment. The measured interaction rates for both 7 B e and 8 B solar neutrinos are in fair agreement with the SSM predictions in case of the Lma-Msw oscillation solution and a further confirmation of the Lma scenario is provided by the absence of a day-night asymmetry in the 7 B e signal. These experimental results allow to improve the upper limit on the neutrino effective magnetic moment. Calibration campaigns aiming to reduce the systematical errors on fiducial volume definition and detector energy response are presently in progress.

  7. Application of LBIC measurements for characterisation of triple junction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kwarikunda, N., E-mail: Nicholas.kwarikunda@live.nmmu.ac.za [Nelson Mandela Metropolitan University, P.O. BOX 77000, Port Elizabeth, 6031 (South Africa); Makerere University, P.O. BOX 7062, Kampala (Uganda); Dyk, E.E. van; Vorster, F.J. [Nelson Mandela Metropolitan University, P.O. BOX 77000, Port Elizabeth, 6031 (South Africa); Okullo, W. [Makerere University, P.O. BOX 7062, Kampala (Uganda); Munji, M.K. [Kenyatta University, P.O. BOX 43844-00100, Nairobi (Kenya)

    2014-04-15

    In this study the Light Beam Induced Current (LBIC) imaging technique was used to characterise InGaP/InGaAs/Ge triple junction solar cells. The study focused on the use of monochromatic and solar light as beam probes to obtain photocurrent response maps from which the presence of any current reducing features on the solar cell were identified. Point illuminated current voltage (I–V) curves were obtained simultaneously while LBIC scanning measurements were being made. Curve fitting using an interval division algorithm based on the single diode model was performed to extract basic point device and performance parameters to give a rough indication of the functioning of the triple junction device. Using red and blue lasers as beam probes, reverse voltage breakdown was observed on the I–V curves which could be attributed to the Ge bottom subcell not being fully activated. The extracted parameters obtained when using monochromatic and solar light beam probes showed a large variation, indicating the dependence of I–V parameters on the spectral content of the beam probe.

  8. Application of LBIC measurements for characterisation of triple junction solar cells

    International Nuclear Information System (INIS)

    Kwarikunda, N.; Dyk, E.E. van; Vorster, F.J.; Okullo, W.; Munji, M.K.

    2014-01-01

    In this study the Light Beam Induced Current (LBIC) imaging technique was used to characterise InGaP/InGaAs/Ge triple junction solar cells. The study focused on the use of monochromatic and solar light as beam probes to obtain photocurrent response maps from which the presence of any current reducing features on the solar cell were identified. Point illuminated current voltage (I–V) curves were obtained simultaneously while LBIC scanning measurements were being made. Curve fitting using an interval division algorithm based on the single diode model was performed to extract basic point device and performance parameters to give a rough indication of the functioning of the triple junction device. Using red and blue lasers as beam probes, reverse voltage breakdown was observed on the I–V curves which could be attributed to the Ge bottom subcell not being fully activated. The extracted parameters obtained when using monochromatic and solar light beam probes showed a large variation, indicating the dependence of I–V parameters on the spectral content of the beam probe.

  9. MgII Linear Polarization Measurements Using the MSFC Solar Ultraviolet Magnetograph

    Science.gov (United States)

    West, Edward; Cirtain, Jonathan; Kobayahsi, Ken; Davis, John; Gary, Allen; Adams, Mitzi

    2011-01-01

    This paper will describe the Marshall Space Flight Center's Solar Ultraviolet Magnetograph (SUMI) sounding rocket program, with emphasis on the polarization characteristics of the VUV optics and their spectral, spatial and polarization resolution. SUMI's first flight (7/30/2010) met all of its mission success criteria and this paper will describe the data that was acquired with emphasis on the MgII linear polarization measurements.

  10. What will the /sup 98/Mo solar-neutrino experiment measure?

    International Nuclear Information System (INIS)

    Bahcall, J.N.

    1988-01-01

    It is shown that the geochemical measurement of the solar-neutrino flux using /sup 98/Mo should yield the same value for the 8 B neutrino flux as is determined by contemporary observations using the /sup 37/Cl and Kamiokande II detectors. The /sup 98/Mo and contemporary fluxes should be equal to an accuracy of better than 1%, provided standard ideas regarding time scales in stellar evolution are correct

  11. A new and inexpensive temperature-measuring system. Application to photovoltaic solar facilities

    Energy Technology Data Exchange (ETDEWEB)

    Bohorquez, Miguel Angel Martinez; Enrique Gomez, Juan Manuel; Andujar Marquez, Jose Manuel [Departamento de Ingenieria Electronica, de Sistemas Informaticos y Automatica, Universidad de Huelva, Carretera Huelva - Palos de la, Frontera S/N, 21819 Huelva (Spain)

    2009-06-15

    This article presents the design, construction and testing of a new and inexpensive digital sensor-based temperature-measuring system, whose principal characteristics are: precision, ease of connection, immunity to noise, remote operation and easy scaling, and all this at a very low cost. This new digital sensor-based measuring system overcomes the traditional problems of digital measuring sensors, offering characteristics similar to Pt100-based measuring systems, and therefore can be used in any installation where reliable temperature measurement is necessary. It is especially suitable for installations where cost is a deciding factor in the choice of measuring system. It presents a practical application of the developed instrumentation system for use in photovoltaic solar facilities. This new temperature-measuring system has been registered in the Spanish Patent and Trademark Office with the number P200803364. (author)

  12. Chapter 1: Reliably Measuring the Performance of Emerging Photovoltaic Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Rumbles, Garry [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Reese, Matthew O [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Marshall, Ashley [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-11-08

    Determining the power conversion efficiency of photovoltaic solar cells, especially those from new, emerging areas of technology, is important if advances in performance are to be made. However, although precise measurements are important, it is the accuracy of these types of measurements that can cause issues. Accurate measurements not only promote the development of new technology platforms, but they also enable comparisons with established technologies and allow assessments of advancements within the same field. This chapter provides insights into how measurements can be made with reasonable accuracy using both the components of the measuring system and a good protocol to acquire good data. The chapter discusses how to measure a calibrated lamp spectrum, determine a spectral mismatch factor, identify the correct reference cell and filter, define the illuminated active area, measure J-V curves to avoid any hysteresis effects, take note of sample degradation issues and avoid the temptation to artificially enhance efficiency data.

  13. The Impact of Indoor and Outdoor Radiometer Calibration on Solar Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Reda, Ibrahim; Robinson, Justin

    2016-06-02

    This study addresses the effect of calibration methodologies on calibration responsivities and the resulting impact on radiometric measurements. The calibration responsivities used in this study are provided by NREL's broadband outdoor radiometer calibration (BORCAL) and a few prominent manufacturers. The BORCAL method provides outdoor calibration responsivity of pyranometers and pyrheliometers at a 45 degree solar zenith angle and responsivity as a function of solar zenith angle determined by clear-sky comparisons to reference irradiance. The BORCAL method also employs a thermal offset correction to the calibration responsivity of single-black thermopile detectors used in pyranometers. Indoor calibrations of radiometers by their manufacturers are performed using a stable artificial light source in a side-by-side comparison of the test radiometer under calibration to a reference radiometer of the same type. These different methods of calibration demonstrated 1percent to 2 percent differences in solar irradiance measurement. Analyzing these values will ultimately enable a reduction in radiometric measurement uncertainties and assist in developing consensus on a standard for calibration.

  14. Past and present variability of the solar-terrestrial system: measurement, data analysis and theoretical models

    Energy Technology Data Exchange (ETDEWEB)

    Cini Castagnoli, G.; Provenzale, A. [eds.

    1997-12-31

    The course Past and present variability of the solar-terrestrial system: measurement, data analysis and theoretical models is explicitly devoted to these issues. A solar cycle ago, in summer 1985, G. Cini organized a similar school, in a time when this field was in a very early stage of development and definitely fewer high-quality measurements were available. After eleven years, the field has grown toward becoming a robust scientific discipline, new data have been obtained, and new ideas have been proposed by both solar physicists and climate dynamicists. For this reason, the authors felt that it was the right time to organize a new summer school, with the aim of formalizing the developments that have taken place during these years, and also for speculating and maybe dreaming of new results that will be achieved in the upcoming years. The papers of the lectures have now been collected in this volume. First, in order to know what the authors talking about, they need to obtain reliable data from terrestrial archives,and to properly date the records that have been measured. To these crucial aspects is devoted the first part of the book, dealing with various types of proxy data and with the difficult issue of the dating of the records.

  15. Photoanode Thickness Optimization and Impedance Spectroscopic Analysis of Dye-Sensitized Solar Cells based on a Carbazole-Containing Ruthenium Dye

    Science.gov (United States)

    Choi, Jongwan; Kim, Felix Sunjoo

    2018-03-01

    We studied the influence of photoanode thickness on the photovoltaic characteristics and impedance responses of the dye-sensitized solar cells based on a ruthenium dye containing a hexyloxyl-substituted carbazole unit (Ru-HCz). As the thickness of photoanode increases from 4.2 μm to 14.8 μm, the dye-loading amount and the efficiency increase. The device with thicker photoanode shows a decrease in the efficiency due to the higher probability of recombination of electron-hole pairs before charge extraction. We also analyzed the electron-transfer and recombination characteristics as a function of photoanode thickness through detailed electrochemical impedance spectroscopy analysis.

  16. Solar Flare Track Exposure Ages in Regolith Particles: A Calibration for Transmission Electron Microscope Measurements

    Science.gov (United States)

    Berger, Eve L.; Keller, Lindsay P.

    2015-01-01

    Mineral grains in lunar and asteroidal regolith samples provide a unique record of their interaction with the space environment. Space weathering effects result from multiple processes including: exposure to the solar wind, which results in ion damage and implantation effects that are preserved in the rims of grains (typically the outermost 100 nm); cosmic ray and solar flare activity, which result in track formation; and impact processes that result in the accumulation of vapor-deposited elements, impact melts and adhering grains on particle surfaces. Determining the rate at which these effects accumulate in the grains during their space exposure is critical to studies of the surface evolution of airless bodies. Solar flare energetic particles (mainly Fe-group nuclei) have a penetration depth of a few millimeters and leave a trail of ionization damage in insulating materials that is readily observable by transmission electron microscope (TEM) imaging. The density of solar flare particle tracks is used to infer the length of time an object was at or near the regolith surface (i.e., its exposure age). Track measurements by TEM methods are routine, yet track production rate calibrations have only been determined using chemical etching techniques [e.g., 1, and references therein]. We used focused ion beam-scanning electron microscope (FIB-SEM) sample preparation techniques combined with TEM imaging to determine the track density/exposure age relations for lunar rock 64455. The 64455 sample was used earlier by [2] to determine a track production rate by chemical etching of tracks in anorthite. Here, we show that combined FIB/TEM techniques provide a more accurate determination of a track production rate and also allow us to extend the calibration to solar flare tracks in olivine.

  17. Measurements of the aerosol chemical composition and mixing state in the Po Valley using multiple spectroscopic techniques

    Science.gov (United States)

    Decesari, S.; Allan, J.; Plass-Duelmer, C.; Williams, B. J.; Paglione, M.; Facchini, M. C.; O'Dowd, C.; Harrison, R. M.; Gietl, J. K.; Coe, H.; Giulianelli, L.; Gobbi, G. P.; Lanconelli, C.; Carbone, C.; Worsnop, D.; Lambe, A. T.; Ahern, A. T.; Moretti, F.; Tagliavini, E.; Elste, T.; Gilge, S.; Zhang, Y.; Dall'Osto, M.

    2014-11-01

    The use of co-located multiple spectroscopic techniques can provide detailed information on the atmospheric processes regulating aerosol chemical composition and mixing state. So far, field campaigns heavily equipped with aerosol mass spectrometers have been carried out mainly in large conurbations and in areas directly affected by their outflow, whereas lesser efforts have been dedicated to continental areas characterised by a less dense urbanisation. We present here the results obtained at a background site in the Po Valley, Italy, in summer 2009. For the first time in Europe, six state-of-the-art spectrometric techniques were used in parallel: aerosol time-of-flight mass spectrometer (ATOFMS), two aerosol mass spectrometers (high-resolution time-of-flight aerosol mass spectrometer - HR-ToF-AMS and soot particle aerosol mass spectrometer - SP-AMS), thermal desorption aerosol gas chromatography (TAG), chemical ionisation mass spectrometry (CIMS) and (offline) proton nuclear magnetic resonance (1H-NMR) spectroscopy. The results indicate that, under high-pressure conditions, atmospheric stratification at night and early morning hours led to the accumulation of aerosols produced by anthropogenic sources distributed over the Po Valley plain. Such aerosols include primary components such as black carbon (BC), secondary semivolatile compounds such as ammonium nitrate and amines and a class of monocarboxylic acids which correspond to the AMS cooking organic aerosol (COA) already identified in urban areas. In daytime, the entrainment of aged air masses in the mixing layer is responsible for the accumulation of low-volatility oxygenated organic aerosol (LV-OOA) and also for the recycling of non-volatile primary species such as black carbon. According to organic aerosol source apportionment, anthropogenic aerosols accumulating in the lower layers overnight accounted for 38% of organic aerosol mass on average, another 21% was accounted for by aerosols recirculated in

  18. Optical depth retrievals from Delta-T SPN1 measurements of broadband solar irradiance at ground

    Science.gov (United States)

    Estelles, Victor; Serrano, David; Segura, Sara; Wood, John; Webb, Nick

    2016-04-01

    The SPN1 radiometer, manufactured by Delta-T Devices Ltd., is an instrument designed for the measurement of global solar irradiance and its components (diffuse, direct) at ground level. In the present study, the direct irradiance component has been used to retrieve an effective total optical depth, by applying the Beer-Lambert law to the broadband measurements. The results have been compared with spectral total optical depths derived from two Cimel CE318 and Prede POM01 sun-sky radiometers, located at the Burjassot site in Valencia (Spain), during years 2013 - 2015. The SPN1 is an inexpensive and versatile instrument for the measurement of the three components of the solar radiation without any mobile part and without any need to azimuthally align the instrument to track the sun (http://www.delta-t.co.uk). The three components of the solar radiation are estimated from a combination of measurements performed by 7 different miniature thermopiles. In turn, the Beer-Lambert law has been applied to the broadband direct solar component to obtain an effective total optical depth, representative of the total extinction in the atmosphere. For the assessment of the total optical depth values retrieved with the SPN1, two different sun-sky radiometers (Cimel CE318 and Prede POM01L) have been employed. Both instruments belong to the international networks AERONET and SKYNET. The modified SUNRAD package has been applied in both Cimel and Prede instruments. Cloud affected data has been removed by applying the Smirnov cloud-screening procedure in the SUNRAD algorithm. The broadband SPN1 total optical depth has been analysed by comparison with the spectral total optical depth from the sun-sky radiometer measurements at wavelengths 440, 500, 675, 870 and 1020 nm. The slopes and intercepts have been estimated to be 0.47 - 0.98 and 0.055 - 0.16 with increasing wavelength. The average correlation coefficients and RMSD were 0.80 - 0.83 and 0.034 - 0.036 for all the channels. The

  19. Gamma spectroscopic studies of the neutron-deficient g-g nucleus 74Kr by means of a neutron multiplicity measurement technique

    International Nuclear Information System (INIS)

    Roth, J.

    1981-01-01

    The g-g nucleus 74 Kr was studied by means of the reaction 58 Ni ( 19 F, p2n#betta#) 74 Kr. In order to make gamma spectroscopic studies at neutron deficient nuclei like 74 Kr a neutron multiplicity measurement technique was developed. Beside #betta# single spectra, #betta# excitation functions, #betta#-#betta# coincidences, #betta# angular distributions, and lifetime measurements by means of this technique all measurements in coincidence with up to two neutrons were taken up. From these measurement data an extended term scheme with 17 newly found excited states could be extracted. To all levels spins and parities could be assigned. From the four energetically lowest levels of the yrast cascade the mean lifetimes could be determined. A double backbending in the sequence of the yrast cascade was interpreted as crossing of the g 9/2 bands. The irregularities in the lower part of the yrast band correspond to the shape consistence picture. The results were considered in connection with the systematics of the even krypton isotopes and compared with a two-quasiparticle-plas-rotor model calculation. (HSI)

  20. Comparison of Solar UVA and UVB Radiation Measured in Selangor, Malaysia

    International Nuclear Information System (INIS)

    Kamarudin, S. U.; Gopir, G.; Yatim, B.; Sanusi, H.; Mahmud, P. S. Megat; Choo, P. Y.

    2010-01-01

    The solar ultraviolet A (UVA) radiation data was measured at Physics Building, Universiti Kebangsaan Malaysia (2 degree sign 55' N, 101 degree sign 46' E, 50m asl) by the Xplorer GLX Pasco that connected to UVA Light sensor. The measured solar UVA data were compared with the total daily solar ultraviolet B (UVB) radiation data recorded by the Malaysian Metrological Department at Petaling Jaya, Malaysia (3 degree sign 06' N, 101 degree sign 39' E, 50m asl) for 18 days in year 2007. The daily total average of UVA radiation received is (298±105) kJm -2 while the total daily maximum is (600±56) kJm -2 . From the analysis, it shows that the values of UVA radiation data were higher than UVB radiation data with the average ratio of 6.41% between 3-14%. A weak positive correlation was found (the correlation coefficient, r, is 0.22). The amount of UVA radiation that reached the earth surface is less dependence on UVB radiation and the factors were discussed.

  1. High latitude stratospheric electrical measurements in fair and foul weather under various solar conditions

    International Nuclear Information System (INIS)

    Holzworth, R.H.

    1981-01-01

    Stratospheric electric field and conductivity measurements during a wide variety of weather and solar conditions are presented. These data are all from high latitude sites in the months of either April or August. The vector electric field is determined by orthogonal double probes connected through high impedance inputs to differential electrometers. The direct conductivity measurement involves determining the relaxation time constant of the medium after refloating a shorted pair of separated probes. Vertical electric field data from several balloon flights with average duration of 18 h at ceiling in fair weather are shown to be well modeled by a simple exponential altitude dependent equation. Examples of solar flare and magnetospheric effects on stratospheric electric fields are shown. Data collected over electrified clouds and thunderstorms are presented along with a discussion of the thunderstorm related electric currents. Lightning stroke signatures in the stratosphere during a large thunderstorm are identified in the electric field data. Current surges through the stratosphere due to DC currents as well as the sferic are calculated. In nearly 1000 h of balloon data no direct solar influence is identified in these data except during major flares. (author)

  2. Design and measured performances of a plane reflector augmented box-type solar-energy cooker

    International Nuclear Information System (INIS)

    Ekechukwu, O.V.

    2001-06-01

    The design philosophy, construction and measured performances of a plane-reflector augmented box-type solar-energy cooker are presented. The experimental solar cooker consists of an aluminum plate absorber painted matt black and a double-glazed lid. The bottom and sides are lagged with fibreglass wool insulator. The reflector consists of a wooden-framed commercially-available specular plane mirror which is sized to form a cover for the box when not in use. Provision is made for four cooking vessels each capable of holding up to 1 kg of water. Results of thermal performance tests show stagnation absorber plate temperatures of 138 deg. C and 119 deg. C for the cooker with and without the plane reflector in place, respectively. Boiling times of 60 minutes (3600 seconds) and 70 minutes (4200 seconds) for 1 kg of water, for the cooker with and without the reflector in place, respectively, were recorded. The solar cooker performance has been rated using the first figure of merit (F 1 ) on the no-load test and the second figure of merit (F 2 ) on the sensible heat tests. Predicted water boiling times using the two figures of merit compared favourable with measured values. The performance of the cooker with the plane reflector in place was improved tremendously compared to that without the reflector in place. (author)

  3. Water vapor measurements at ALOMAR over a solar cycle compared with model calculations by LIMA

    Science.gov (United States)

    Hartogh, P.; Sonnemann, G. R.; Grygalashvyly, M.; Song, Li; Berger, U.; Lübken, F.-J.

    2010-01-01

    Microwave water vapor measurements between 40 and 80 km altitude over a solar cycle (1996-2006) were carried out in high latitudes at Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR) (69.29°N, 16.03°E), Norway. Some smaller gaps and three interruptions of monitoring in the winters 1996/1997 and 2005/2006 and from spring 2001 to spring 2002 occurred during this period. The observations show a distinct year-to-year variability not directly related to solar Lyman-α radiation. In winter the water vapor mixing ratios in the upper domain were anticorrelated to the solar activity, whereas in summer, minima occurred in the years after the solar maximum in 2000/2001. In winter, sudden stratospheric warmings (SSWs) modulated the water vapor mixing ratios. Within the stratopause region a middle atmospheric water vapor maximum was observed, which results from the methane oxidation and is a regular feature there. The altitude of the maximum increased by approximately 5 km as summer approached. The largest mixing ratios were monitored in autumn. During the summer season a secondary water vapor maximum also occurred above 65 km most pronounced in late summer. The solar Lyman-α radiation impacts the water vapor mixing ratio particularly in winter above 65 km. In summer the correlation is positive below 70 km. The correlation is also positive in the lower mesosphere/stratopause region in winter due to the action of sudden stratospheric warmings, which occur more frequently under the condition of high solar activity and the enhancing the humidity. A strong day-to-day variability connected with planetary wave activity was found throughout the entire year. Model calculations by means of Leibniz-Institute Middle Atmosphere model (LIMA) reflect the essential patterns of the water vapor variation, but the results also show differences from the observations, indicating that exchange processes between the troposphere and stratosphere not modeled by LIMA could have

  4. The effect of different solar simulators on the measurement of short-circuit current temperature coefficients

    Science.gov (United States)

    Curtis, H. B.; Hart, R. E., Jr.

    1982-01-01

    Gallium arsenide solar cells are considered for several high temperature missions in space. Both near-Sun and concentrator missions could involve cell temperatures on the order of 200 C. Performance measurements of cells at elevated temperatures are usually made using simulated sunlight and a matched reference cell. Due to the change in bandgap with increasing temperature at portions of the spectrum where considerable simulated irradiance is present, there are significant differences in measured short circuit current at elevated temperatures among different simulators. To illustrate this, both experimental and theoretical data are presented for gallium arsenide cells.

  5. A comparative study of satellite estimation for solar insolation in Albania with ground measurements

    International Nuclear Information System (INIS)

    Mitrushi, Driada; Berberi, Pëllumb; Muda, Valbona; Buzra, Urim; Bërdufi, Irma; Topçiu, Daniela

    2016-01-01

    The main objective of this study is to compare data provided by Database of NASA with available ground data for regions covered by national meteorological net NASA estimates that their measurements of average daily solar radiation have a root-mean-square deviation RMSD error of 35 W/m"2 (roughly 20% inaccuracy). Unfortunately valid data from meteorological stations for regions of interest are quite rare in Albania. In these cases, use of Solar Radiation Database of NASA would be a satisfactory solution for different case studies. Using a statistical method allows to determine most probable margins between to sources of data. Comparison of mean insulation data provided by NASA with ground data of mean insulation provided by meteorological stations show that ground data for mean insolation results, in all cases, to be underestimated compared with data provided by Database of NASA. Converting factor is 1.149.

  6. Comet 73P Measurements of Solar Wind Interactions, Cometary Ion Pickup, and Spatial Distribution

    Science.gov (United States)

    Gilbert, J. A.; Lepri, S. T.; Rubin, M.; Combi, M. R.; Zurbuchen, T.

    2015-12-01

    Several fragments of Comet 73P/Schwassmann-Wachmann 3 passed near the Earth following a 2006 disintegration episode. Unique measurements regarding the charge state composition and the elemental abundances of both cometary and heliospheric plasma were made during this time by both the ACE/SWICS and Wind/STICS sensors. As the solar wind passed through the neutral cometary coma, it experienced charge exchange that was observed as an increase in the ratio of He+/He++. In addition, particles originating from fragments trailing the major cometary objects were ionized and picked up by the solar wind. The cometary material can be identified by the concentrations of water-group pickup ions having a mass-per-charge ratio of 16-18 amu/e, indicating that these are actively sublimating fragments. Here we present an analysis of cometary composition, spatial distribution, directionality, and heliospheric interactions with a focus on Helium, Carbon (C/O), and water-group ions.

  7. Alive and well: A short review about standard solar models

    Energy Technology Data Exchange (ETDEWEB)

    Serenelli, Aldo [Campus UAB, Carrer de Can Magrans S/N, Instituto de Ciencias del Espacio (ICE/CSIC-IEEC), Cerdanyola del Valles (Spain)

    2016-04-15

    Standard solar models (SSMs) provide a reference framework across a number of research fields: solar and stellar models, solar neutrinos, particle physics the most conspicuous among them. The accuracy of the physical description of the global properties of the Sun that SSMs provide has been challenged in the last decade by a number of developments in stellar spectroscopic techniques. Over the same period of time, solar neutrino experiments, and Borexino in particular, have measured the four solar neutrino fluxes from the pp-chains that are associated with 99% of the nuclear energy generated in the Sun. Borexino has also set the most stringent limit on CNO energy generation, only ∝ 40% larger than predicted by SSMs. More recently, and for the first time, radiative opacity experiments have been performed at conditions that closely resemble those at the base of the solar convective envelope. In this article, we review these developments and discuss the current status of SSMs, including its intrinsic limitations. (orig.)

  8. Monodeuterated methane in the outer solar system. I. Spectroscopic analysis of the bands at 1.55 and 1.95 microns

    International Nuclear Information System (INIS)

    Lutz, B.L.; de Bergh, C.; Maillard, J.P.

    1983-01-01

    The analysis of the near-infrared spectrum of monodeuterated methane (CH 3 D) near 6400 cm -1 and 5100 cm -1 is presented as the first of a series of papers dealing with laboratory studies of this molecule and with observational searches for it in outer solar system objects. Three new parallel bands which have locally perturbed upper states connecting with the ground state are identified, and approximate rotational constants are derived. The band centered near 6425 cm -1 and the 9613 A band previously analyzed by Lutz, Danehy, and Ramsay are found to form an apparent vibrational progression with the ν 2 fundamental at 2200 cm -1 , and vibrational assignments of 3ν 2 and 5ν 2 , respectively, are proposed. Detailed comparison of the rotational constants of the states involved is shown to support these assignments

  9. Solar UVR instrument inter-comparison focussing on measurement interval recording setting and solar zenith angle as important factors

    CSIR Research Space (South Africa)

    Wright, GY

    2015-09-01

    Full Text Available considerations, to make meaningful deductions from the data. By comparing two solar UVR instruments, namely, a UV biometer and a Davis Vantage Pro2 UVR Detector, we look at an important factor influencing ambient solar UVR, namely SZA, and its impact... Vantage Pro2 UV detector comprises a transducer which is a semiconductor photodiode with a spectral response that matches the McKinley/Diffey Erythemal Action Spectrum. It includes a diffuser which provides good cosine response and multiple hard...

  10. High Fidelity Measurement of Free Space Solar Particle Event and Galactic Cosmic Ray Environments at Intermediate Energies

    Science.gov (United States)

    Leitgab, M.

    2018-02-01

    A charged particle measurement experiment mounted externally to the Deep Space Gateway is proposed, contributing to improving astronaut radiation exposure management during Solar Particle Events and Extra Vehicular Activities.

  11. Accounting for the measurement error of spectroscopically inferred soil carbon data for improved precision of spatial predictions.

    Science.gov (United States)

    Somarathna, P D S N; Minasny, Budiman; Malone, Brendan P; Stockmann, Uta; McBratney, Alex B

    2018-08-01

    Spatial modelling of environmental data commonly only considers spatial variability as the single source of uncertainty. In reality however, the measurement errors should also be accounted for. In recent years, infrared spectroscopy has been shown to offer low cost, yet invaluable information needed for digital soil mapping at meaningful spatial scales for land management. However, spectrally inferred soil carbon data are known to be less accurate compared to laboratory analysed measurements. This study establishes a methodology to filter out the measurement error variability by incorporating the measurement error variance in the spatial covariance structure of the model. The study was carried out in the Lower Hunter Valley, New South Wales, Australia where a combination of laboratory measured, and vis-NIR and MIR inferred topsoil and subsoil soil carbon data are available. We investigated the applicability of residual maximum likelihood (REML) and Markov Chain Monte Carlo (MCMC) simulation methods to generate parameters of the Matérn covariance function directly from the data in the presence of measurement error. The results revealed that the measurement error can be effectively filtered-out through the proposed technique. When the measurement error was filtered from the data, the prediction variance almost halved, which ultimately yielded a greater certainty in spatial predictions of soil carbon. Further, the MCMC technique was successfully used to define the posterior distribution of measurement error. This is an important outcome, as the MCMC technique can be used to estimate the measurement error if it is not explicitly quantified. Although this study dealt with soil carbon data, this method is amenable for filtering the measurement error of any kind of continuous spatial environmental data. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Solar Energetic Particles Events and Human Exploration: Measurements in a Space Habitat

    Science.gov (United States)

    Narici, L.; Berrilli, F.; Casolino, M.; Del Moro, D.; Forte, R.; Giovannelli, L.; Martucci, M.; Mergè, M.; Picozza, P.; Rizzo, A.; Scardigli, S.; Sparvoli, R.; Zeitlin, C.

    2016-12-01

    Solar activity is the source of Space Weather disturbances. Flares, CME and coronal holes modulate physical conditions of circumterrestrial and interplanetary space and ultimately the fluxes of high-energy ionized particles, i.e., solar energetic particle (SEP) and galactic cosmic ray (GCR) background. This ionizing radiation affects spacecrafts and biological systems, therefore it is an important issue for human exploration of space. During a deep space travel (for example the trip to Mars) radiation risk thresholds may well be exceeded by the crew, so mitigation countermeasures must be employed. Solar particle events (SPE) constitute high risks due to their impulsive high rate dose. Forecasting SPE appears to be needed and also specifically tailored to the human exploration needs. Understanding the parameters of the SPE that produce events leading to higher health risks for the astronauts in deep space is therefore a first priority issue. Measurements of SPE effects with active devices in LEO inside the ISS can produce important information for the specific SEP measured, relative to the specific detector location in the ISS (in a human habitat with a shield typical of manned space-crafts). Active detectors can select data from specific geo-magnetic regions along the orbits, allowing geo-magnetic selections that best mimic deep space radiation. We present results from data acquired in 2010 - 2012 by the detector system ALTEA inside the ISS (18 SPEs detected). We compare this data with data from the detector Pamela on a LEO satellite, with the RAD data during the Curiosity Journey to Mars, with GOES data and with several Solar physical parameters. While several features of the radiation modulation are easily understood by the effect of the geomagnetic field, as an example we report a proportionality of the flux in the ISS with the energetic proton flux measured by GOES, some features appear more difficult to interpret. The final goal of this work is to find the

  13. Spatio-temporal representativeness of ground-based downward solar radiation measurements

    Science.gov (United States)

    Schwarz, Matthias; Wild, Martin; Folini, Doris

    2017-04-01

    Surface solar radiation (SSR) is most directly observed with ground based pyranometer measurements. Besides measurement uncertainties, which arise from the pyranometer instrument itself, also errors attributed to the limited spatial representativeness of observations from single sites for their large-scale surrounding have to be taken into account when using such measurements for energy balance studies. In this study the spatial representativeness of 157 homogeneous European downward surface solar radiation time series from the Global Energy Balance Archive (GEBA) and the Baseline Surface Radiation Network (BSRN) were examined for the period 1983-2015 by using the high resolution (0.05°) surface solar radiation data set from the Satellite Application Facility on Climate Monitoring (CM-SAF SARAH) as a proxy for the spatiotemporal variability of SSR. By correlating deseasonalized monthly SSR time series form surface observations against single collocated satellite derived SSR time series, a mean spatial correlation pattern was calculated and validated against purely observational based patterns. Generally decreasing correlations with increasing distance from station, with high correlations (R2 = 0.7) in proximity to the observational sites (±0.5°), was found. When correlating surface observations against time series from spatially averaged satellite derived SSR data (and thereby simulating coarser and coarser grids), very high correspondence between sites and the collocated pixels has been found for pixel sizes up to several degrees. Moreover, special focus was put on the quantification of errors which arise in conjunction to spatial sampling when estimating the temporal variability and trends for a larger region from a single surface observation site. For 15-year trends on a 1° grid, errors due to spatial sampling in the order of half of the measurement uncertainty for monthly mean values were found.

  14. Solar pulsations

    International Nuclear Information System (INIS)

    Zirker, J.B.

    1980-01-01

    Oscillations of the surface of the sun, with periods between 5 and 160 min, have been observed by several spectroscopic techniques, and preliminary interpretations have been offered. The 5-min oscillations are global, nonradial, acoustic standing waves in the subsurface zone. Internal differential rotation speeds have been deduced from the Doppler splitting of these waves. Oscillations with longer periods have been reported, but need confirmation. The longest periods offer a tool for investigating the solar interior

  15. Determination of Performance Measuring Parameters of an Improved Dual Paraboloid Solar Cooker

    Directory of Open Access Journals (Sweden)

    Suhail Zaki Farooqui

    2017-01-01

    Full Text Available An experimental investigation into the performance evaluation of an improved dual reflector foldable paraboloid solar cooker has been reported, along with its energy and exergy analysis. The best attribute of this lightweight and low-cost solar cooker is its high performance coupled with the ease of handling. The cooker utilizes two paraboloid reflectors made out of Mylar-coated fiberglass dishes, each having a diameter of 90 cm and focal length of 105 cm. The total intercepted radiation energy is 1.08 kW under standard test conditions. Stagnation temperatures of up to 330°C and cooking temperatures of up to 290°C have been attained with load. Altogether, 9 experiments have been performed with and without load. Loaded tests have been conducted with water and vegetable oil. Results indicate an average cooking power of 485 W, peak exergy gain of 60.53 W, quality factor of 0.077, and a high product of temperature difference gap at half peak power to peak power of 4364.33 W·K. The maximum exergy output power attained was 70 W, while maximum exergy efficiency was 8–10%. All performance measuring parameters indicate that it is a high performance solar cooker for rural and urban communities and is suitable for all types of oil- and water-based cooking.

  16. A Method to Reconstruct the Solar-Induced Canopy Fluorescence Spectrum from Hyperspectral Measurements

    Directory of Open Access Journals (Sweden)

    Feng Zhao

    2014-10-01

    Full Text Available A method for canopy Fluorescence Spectrum Reconstruction (FSR is proposed in this study, which can be used to retrieve the solar-induced canopy fluorescence spectrum over the whole chlorophyll fluorescence emission region from 640–850 nm. Firstly, the radiance of the solar-induced chlorophyll fluorescence (Fs at five absorption lines of the solar spectrum was retrieved by a Spectral Fitting Method (SFM. The Singular Vector Decomposition (SVD technique was then used to extract three basis spectra from a training dataset simulated by the model SCOPE (Soil Canopy Observation, Photochemistry and Energy fluxes. Finally, these basis spectra were linearly combined to reconstruct the Fs spectrum, and the coefficients of them were determined by Weighted Linear Least Squares (WLLS fitting with the five retrieved Fs values. Results for simulated datasets indicate that the FSR method could accurately reconstruct the Fs spectra from hyperspectral measurements acquired by instruments of high Spectral Resolution (SR and Signal to Noise Ratio (SNR. The FSR method was also applied to an experimental dataset acquired in a diurnal experiment. The diurnal change of the reconstructed Fs spectra shows that the Fs radiance around noon was higher than that in the morning and afternoon, which is consistent with former studies. Finally, the potential and limitations of this method are discussed.

  17. Determining the solar-flare photospheric scale height from SMM gamma-ray measurements

    Science.gov (United States)

    Lingenfelter, Richard E.

    1991-01-01

    A connected series of Monte Carlo programs was developed to make systematic calculations of the energy, temporal and angular dependences of the gamma-ray line and neutron emission resulting from such accelerated ion interactions. Comparing the results of these calculations with the Solar Maximum Mission/Gamma Ray Spectrometer (SMM/GRS) measurements of gamma-ray line and neutron fluxes, the total number and energy spectrum of the flare-accelerated ions trapped on magnetic loops at the Sun were determined and the angular distribution, pitch angle scattering, and mirroring of the ions on loop fields were constrained. Comparing the calculations with measurements of the time dependence of the neutron capture line emission, a determination of the He-3/H ratio in the photosphere was also made. The diagnostic capabilities of the SMM/GRS measurements were extended by developing a new technique to directly determine the effective photospheric scale height in solar flares from the neutron capture gamma-ray line measurements, and critically test current atmospheric models in the flare region.

  18. PAMELA’S MEASUREMENTS OF MAGNETOSPHERIC EFFECTS ON HIGH-ENERGY SOLAR PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Adriani, O.; Bongi, M. [Department of Physics and Astronomy, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy); Barbarino, G. C. [Department of Physics, University of Naples “Federico II,” I-80126 Naples (Italy); Bazilevskaya, G. A. [Lebedev Physical Institute, RU-119991 Moscow (Russian Federation); Bellotti, R.; Bruno, A. [University of Bari, I-70126 Bari (Italy); Boezio, M.; Bonvicini, V.; Carbone, R. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Bogomolov, E. A. [Ioffe Physical Technical Institute, RU-194021 St. Petersburg (Russian Federation); Bottai, S. [INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Bravar, U. [Space Science Center, University of New Hampshire, Durham, NH (United States); Cafagna, F. [INFN, Sezione di Bari, I-70126 Bari (Italy); Campana, D. [INFN, Sezione di Naples, I-80126 Naples (Italy); Carlson, P. [KTH, Department of Physics, and the Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Centre, SE-10691 Stockholm (Sweden); Casolino, M.; De Donato, C. [INFN, Sezione di Rome “Tor Vergata,” I-00133 Rome (Italy); Castellini, G. [IFAC, I-50019 Sesto Fiorentino, Florence (Italy); Christian, E. R.; Nolfo, G. A. de, E-mail: georgia.a.denolfo@nasa.gov [Heliophysics Division, NASA Goddard Space Flight Center, Greenbelt, MD (United States); and others

    2015-03-01

    The nature of particle acceleration at the Sun, whether through flare reconnection processes or through shocks driven by coronal mass ejections, is still under scrutiny despite decades of research. The measured properties of solar energetic particles (SEPs) have long been modeled in different particle-acceleration scenarios. The challenge has been to disentangle the effects of transport from those of acceleration. The Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) instrument enables unique observations of SEPs including the composition and angular distribution of the particles about the magnetic field, i.e., pitch angle distribution, over a broad energy range (>80 MeV)—bridging a critical gap between space-based and ground-based measurements. We present high-energy SEP data from PAMELA acquired during the 2012 May 17 SEP event. These data exhibit differential anisotropies and thus transport features over the instrument rigidity range. SEP protons exhibit two distinct pitch angle distributions: a low-energy population that extends to 90° and a population that is beamed at high energies (>1 GeV), consistent with neutron monitor measurements. To explain a low-energy SEP population that exhibits significant scattering or redistribution accompanied by a high-energy population that reaches the Earth relatively unaffected by dispersive transport effects, we postulate that the scattering or redistribution takes place locally. We believe that these are the first comprehensive measurements of the effects of solar energetic particle transport in the Earth’s magnetosheath.

  19. Round robins of solar cells to evaluate measurement systems of different european research institutes

    Energy Technology Data Exchange (ETDEWEB)

    Manshanden, P.; Van der Brog, N.J.C.M. [ECN Solar, Westerduinweg 3, 1755 LE Petten (Netherlands); Bliss, M.; Mihaylov, B.; Gottschlag, R. [CREST, Holywell Park MBG GJ/Gx, Loughborough Univeristy, Leicestershire, LE11 3TU (United Kingdom); Izzi, M.; Tucci, M. [ENEA CASACCIA, Via Anguillarese 301, 00123 Roma (Italy); Roca, F.; Pellegrino, M.; Romano, A.; Graditi, G. [ENEA PORTICI, P. le E. Fermi Localita Granatello, 80055 Portici Napoli (Italy); Hohl-Ebinger, J.; Warta, W. [Fraunhofer ISE, Berliner Allee 30, 79110 Freiburg (Germany); Debucquoy, M.; El Daif, O.; Gordon, I. [IMEC, Kapeldreef 75, B-3001 Heverlee (Belgium); Champliaud, J.; Jouini, A. [INES, 50 avenue du lac Leman, BP 332, 73377, Le Bourget-du-Lac (France); Glatz-Reichenbach, J. [ISC, Rudolf Diesel Str. 15, D-78467 Konstanz (Germany); Bothe, K. [ISFH, Am Ohrberg 1, 31860 Emmerthal (Germany); Herguth, A. [University of Konstanz, Universitaetsstrasse 10, 78457 Konstanz (Germany)

    2013-10-15

    Determination of the solar cell efficiency and internal quantum efficiency are standard characterization methods used by the majority of research institutes. Random errors can be assessed by institutes themselves by repeated measurements, but systematic deviations cannot be assessed without comparisons with other institutes. The comparisons were performed for illuminated IV, spectral response and reflection measurements. The results were split into systematic differences between the partners and random differences within an institute for a single measurement session. The total differences are: J{sub sc}: 0.27 A, V{sub oc}: 8.5 mV, FF: 2.4 %, {eta}: 0.6%, spectral response: 0.14 A/W and reflection: 0.08. For all measurement methods, the systematic differences exceeded the random differences. The major component for the systematic differences is likely the reference device, but also temperature control, contacting scheme and setup differences play a part.

  20. Solar ultraviolet radiation in Syria measurements and relationship with skin cancer incidence

    International Nuclear Information System (INIS)

    Othman, I; Baydon, S.A.; Dawood, S.

    1994-11-01

    Seasonal variations of solar UVB (285-320) and UVA (320-400) were measured in three sites in Syria (33-37 N sup O) for two years: 1992-1993. UVB measurements were performed using polysulphone films and Robertson-Berger meter, while UVA measurements were done by NVA intensity meter. Two sets of measurements were carried out : - Maximal daily doses three times a week (every other day) - Diurnal variations from sun-rise to sun-set every two hours twice a month (every fortnight). The biological consequences of ultraviolet radiation withreference to some epidemiological data of skin cancer incidence in Syria since 1980 were discussed .(author). 36 refs., 21 figs., 11 tabs

  1. Solar shading for low energy use and daylight quality in offices: Simulations, measurements and design tools

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, M.C.

    2001-11-01

    This thesis investigates the impact of solar shading devices on energy use and daylight quality in office rooms. The impact on energy use is analysed through computer simulations with the dynamic energy simulation program Derob-LTH while the impact on daylight quality is investigated through measurements in full-scale experimental office rooms and simulations with the program Radiance. This thesis also includes a literature review of research on solar shading as well as design tools to incorporate shading devices at an early stage in the design of buildings. This thesis indicates that, in cold countries, shading devices may provide more annual energy savings than any solar-protective (reflective, tinted) glazing and that the optimum glazing transmittance is orientation- and climate-dependent. For example, high annual energy savings are obtained on the south facade with higher transmittance glazings (compared with the east and west facade) because the potential for passive solar gain utilisation in the winter is high in comparison with the annual cooling demand. Exterior shading devices like awnings and overhangs may reduce the cooling demand dramatically but they are not suitable as daylight (glare) control devices. Devices like screens and venetian blinds are preferable because they cover the entire window area, which prevents sunlight patches in the room and the direct view of the bright sky. Screens and venetian blinds also reduce daylight in the room to levels that are suitable for computer work. However, it is essential that the screen is of a diffusing type since screens with a strong (specular) transmittance component result in poor daylight quality. The study on daylight quality also indicated that a screen transmittance of around 15 % may be optimum for a standard (3.5 by 6.0 m{sup 2}) south-oriented office room with a window covering around 25 % of the facade area (12 % of the floor area)

  2. The Integrated Science Investigation of the Sun (ISIS): Energetic Particle Measurements for the Solar Probe Plus Mission

    Science.gov (United States)

    McComas, D. J.; Christian, E. R.; Wiedenbeck, M. E.; McNutt, R. L.; Cummings, A. C.; Desai, M. I.; Giacalone, J.; Hill, M. E.; Mewaldt, R. A.; Krimigis, SA. M.; hide

    2011-01-01

    One of the major goals of NASA's Solar Probe Plus (SPP) mission is to determine the mechanisms that accelerate and transport high-energy particles from the solar atmosphere out into the heliosphere. Processes such as coronal mass ejections and solar flares, which peak roughly every 11 years around solar maximum, release huge quantities of energized matter, magnetic fields and electromagnetic radiation into space. The high-energy particles, known as solar energetic particles or SEPs, present a serious radiation threat to human explorers living and working outside low-Earth orbit and to technological assets such as communications and scientific satellites in space. This talk describes the Integrated Science Investigation of the Sun (ISIS) - Energetic Particle Instrument suite. ISIS measures key properties such as intensities, energy spectra, composition, and angular distributions of the low-energy suprathermal source populations, as well as the more hazardous, higher energy particles ejected from the Sun. By making the first-ever direct measurements of the near-Sun regions where the acceleration takes place, ISIS will provide the critical measurements that, when integrated with other SPP instruments and with solar and interplanetary observations, will lead to a revolutionary new understanding of the Sun and major drivers of solar system space weather.

  3. Fully automated atlas-based method for prescribing 3D PRESS MR spectroscopic imaging: Toward robust and reproducible metabolite measurements in human brain.

    Science.gov (United States)

    Bian, Wei; Li, Yan; Crane, Jason C; Nelson, Sarah J

    2018-02-01

    To implement a fully automated atlas-based method for prescribing 3D PRESS MR spectroscopic imaging (MRSI). The PRESS selected volume and outer-volume suppression bands were predefined on the MNI152 standard template image. The template image was aligned to the subject T 1 -weighted image during a scan, and the resulting transformation was then applied to the predefined prescription. To evaluate the method, H-1 MRSI data were obtained in repeat scan sessions from 20 healthy volunteers. In each session, datasets were acquired twice without repositioning. The overlap ratio of the prescribed volume in the two sessions was calculated and the reproducibility of inter- and intrasession metabolite peak height and area ratios was measured by the coefficient of variation (CoV). The CoVs from intra- and intersession were compared by a paired t-test. The average overlap ratio of the automatically prescribed selection volumes between two sessions was 97.8%. The average voxel-based intersession CoVs were less than 0.124 and 0.163 for peak height and area ratios, respectively. Paired t-test showed no significant difference between the intra- and intersession CoVs. The proposed method provides a time efficient method to prescribe 3D PRESS MRSI with reproducible imaging positioning and metabolite measurements. Magn Reson Med 79:636-642, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  4. Spectroscopic methods

    International Nuclear Information System (INIS)

    Ivanovich, M.; Murray, A.

    1992-01-01

    The principles involved in the interaction of nuclear radiation with matter are described, as are the principles behind methods of radiation detection. Different types of radiation detectors are described and methods of detection such as alpha, beta and gamma spectroscopy, neutron activation analysis are presented. Details are given of measurements of uranium-series disequilibria. (UK)

  5. Making Ultraviolet Spectro-Polarimetry Polarization Measurements with the MSFC Solar Ultraviolet Magnetograph Sounding Rocket

    Science.gov (United States)

    West, Edward; Cirtain, Jonathan; Kobayashi, Ken; Davis, John; Gary, Allen

    2011-01-01

    This paper will describe the Marshall Space Flight Center's Solar Ultraviolet Magnetograph Investigation (SUMI) sounding rocket program. This paper will concentrate on SUMI's VUV optics, and discuss their spectral, spatial and polarization characteristics. While SUMI's first flight (7/30/2010) met all of its mission success criteria, there are several areas that will be improved for its second and third flights. This paper will emphasize the MgII linear polarization measurements and describe the changes that will be made to the sounding rocket and how those changes will improve the scientific data acquired by SUMI.

  6. Multi-Spacecraft 3D differential emission measure tomography of the solar corona: STEREO results.

    Science.gov (United States)

    Vásquez, A. M.; Frazin, R. A.

    We have recently developed a novel technique (called DEMT) for the em- pirical determination of the three-dimensional (3D) distribution of the so- lar corona differential emission measure through multi-spacecraft solar ro- tational tomography of extreme-ultaviolet (EUV) image time series (like those provided by EIT/SOHO and EUVI/STEREO). The technique allows, for the first time, to develop global 3D empirical maps of the coronal elec- tron temperature and density, in the height range 1.0 to 1.25 RS . DEMT constitutes a simple and powerful 3D analysis tool that obviates the need for structure specific modeling.

  7. Emissivity-corrected power loss calibration for lock-in thermography measurements on silicon solar cells

    International Nuclear Information System (INIS)

    Kasemann, Martin; Walter, Benjamin; Meinhardt, Christoph; Ebser, Jan; Kwapil, Wolfram; Warta, Wilhelm

    2008-01-01

    This paper describes power loss calibration procedures with implemented emissivity correction. The determination of our emissivity correction matrix does neither rely on blackbody reference measurements nor on the knowledge of any sample temperatures. To describe the emissivity-corrected power calibration procedures in detail, we review the theory behind lock-in thermography and show experimentally that the lock-in signal is proportional to the power dissipation in the solar cell. Experiments show the successful application of our emissivity correction procedure, which significantly improves the informative value of lock-in thermography images and the reliability of the conclusions drawn from these images

  8. Autonomous portable solar ultraviolet spectroradiometer (APSUS) - a new CCD spectrometer system for localized, real-time solar ultraviolet (280-400 nm) radiation measurement.

    Science.gov (United States)

    Hooke, Rebecca; Pearson, Andy; O'Hagan, John

    2014-01-01

    Terrestrial solar ultraviolet (UV) radiation has significant implications for human health and increasing levels are a key concern regarding the impact of climate change. Monitoring solar UV radiation at the earth's surface is therefore of increasing importance. A new prototype portable CCD (charge-coupled device) spectrometer-based system has been developed that monitors UV radiation (280-400 nm) levels at the earth's surface. It has the ability to deliver this information to the public in real time. Since the instrument can operate autonomously, it is called the Autonomous Portable Solar Ultraviolet Spectroradiometer (APSUS). This instrument incorporates an Ocean Optics QE65000 spectrometer which is contained within a robust environmental housing. The APSUS system can gather reliable solar UV spectral data from approximately April to October inclusive (depending on ambient temperature) in the UK. In this study the new APSUS unit and APSUS system are presented. Example solar UV spectra and diurnal UV Index values as measured by the APSUS system in London and Weymouth in the UK in summer 2012 are shown. © 2014 Crown copyright. Photochemistry and Photobiology © 2014 The American Society of Photobiology. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland and Public Health England.

  9. Evaluation of the Delta-T SPN1 radiometer for the measurement of solar irradiance components

    Science.gov (United States)

    Estelles, Victor; Serrano, David; Segura, Sara; Wood, John; Webb, Nick; Utrillas, Maria Pilar

    2016-04-01

    In this study we analyse the performance of an SPN1 radiometer built by Delta-T Devices Ltd. to retrieve global solar irradiance at ground and its components (diffuse, direct) in comparison with measurements from two Kipp&Zonen CMP21 radiometers and a Kipp&Zonen CHP1 pirheliometer, mounted on an active Solys-2 suntracker at the Burjassot site (Valencia, Spain) using data acquired every minute during years 2013 - 2015. The measurement site is close to sea level (60 m a.s.l.), near the Mediterranean coast (10 km) and within the metropolitan area of Valencia City (over 1.500.000 inhabitants). The SPN1 is an inexpensive and versatile instrument for the measurement of the three components of the solar radiation without any mobile part and without any need to azimuthally align the instrument to track the sun (http://www.delta-t.co.uk). The three components of the solar radiation are estimated from a combination of measurements performed by 7 different miniature thermopiles. The SPN1 pyranometer measures the irradiance between 400 and 2700 nm, and the nominal uncertainty for the individual readings is about 8% ± 10 W/m2 (5% for the daily averages). The pyranometer Kipp&Zonen CMP21 model is a secondary standard for the measurement of broadband solar global irradiance in horizontal planes. Two ventilated CMP21 are used for the measurement of the global and diffuse irradiances. The expected total daily uncertainty of the radiometer is estimated to be 2%. The pirheliometer Kipp&Zonen CHP1 is designed for the measurement of the direct irradiance. The principles are similar to the CMP21 pyranometer. The results of the comparison show that the global irradiance from the SPN1 compares very well with the CMP21, with absolute RMSD and MBD differences below the combined uncertainties (15 W/m2 and -5.4 W/m2, respectively; relative RMSD of 3.1%). Both datasets are very well correlated, with a correlation coefficient higher than 0.997 and a slope and intercept very close to 1 and 0

  10. High-accuracy and high-sensitivity spectroscopic measurement of dinitrogen pentoxide (N2O5) in an atmospheric simulation chamber using a quantum cascade laser.

    Science.gov (United States)

    Yi, Hongming; Wu, Tao; Lauraguais, Amélie; Semenov, Vladimir; Coeur, Cecile; Cassez, Andy; Fertein, Eric; Gao, Xiaoming; Chen, Weidong

    2017-12-04

    A spectroscopic instrument based on a mid-infrared external cavity quantum cascade laser (EC-QCL) was developed for high-accuracy measurements of dinitrogen pentoxide (N 2 O 5 ) at the ppbv-level. A specific concentration retrieval algorithm was developed to remove, from the broadband absorption spectrum of N 2 O 5 , both etalon fringes resulting from the EC-QCL intrinsic structure and spectral interference lines of H 2 O vapour absorption, which led to a significant improvement in measurement accuracy and detection sensitivity (by a factor of 10), compared to using a traditional algorithm for gas concentration retrieval. The developed EC-QCL-based N 2 O 5 sensing platform was evaluated by real-time tracking N 2 O 5 concentration in its most important nocturnal tropospheric chemical reaction of NO 3 + NO 2 ↔ N 2 O 5 in an atmospheric simulation chamber. Based on an optical absorption path-length of L eff = 70 m, a minimum detection limit of 15 ppbv was achieved with a 25 s integration time and it was down to 3 ppbv in 400 s. The equilibrium rate constant K eq involved in the above chemical reaction was determined with direct concentration measurements using the developed EC-QCL sensing platform, which was in good agreement with the theoretical value deduced from a referenced empirical formula under well controlled experimental conditions. The present work demonstrates the potential and the unique advantage of the use of a modern external cavity quantum cascade laser for applications in direct quantitative measurement of broadband absorption of key molecular species involved in chemical kinetic and climate-change related tropospheric chemistry.

  11. Measurement of minority carrier lifetime in silicon solar cells using an a. c. light source

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, A.; Gupta, R.S.; Srivastava, G.P. (Delhi Univ., New Delhi (India). Dept. of Electronic Sciences); Jain, V.K. (Solid State Physics Lab., Delhi (India)); Chilana, G.S. (Delhi Univ. (India). Dept. of Physics and Astrophysics)

    1990-06-01

    A simple technique for the measurement of minority carriers lifetimes is proposed. It is based on the modification of the junction structure by the addition of a d.c. bias to the a.c. source. This always keeps the solar cell in the forward biased condition and also keeps it in the operating range. This method provides a direct measurement of minority carriers lifetimes. The lifetime is found to increase from 2.89 {mu}s at 30deg C to 4.55 {mu}s at 120deg C. The lifetime reduces to 1.45 {mu}s at liquid air temperature. Based on these lifetime measurements, the diffusion length of the carriers has also been calculated. (orig.).

  12. Measuring Air Temperature in Glazed Ventilated Facades in the Presence of Direct Solar Radiation

    DEFF Research Database (Denmark)

    Kalyanova, Olena; Zanghirella, Fabio; Heiselberg, Per

    2007-01-01

    A distinctive element of buildings with a double glazed façade is naturally or mechanically driven flow in a ventilated cavity. Accurate air temperature measurements in the cavity are crucial to evaluate the dynamic performance of the façade, to predict and control its behavior as a significant...... part of the complete ventilation system. Assessment of necessary cooling/heating loads and of the whole building energy performance will then depend on the accuracy of measured air temperature. The presence of direct solar radiation is an essential element for the façade operation, but it can heavily...... affect measurements of air temperature and may lead to errors of high magnitude using bare thermocouples and even adopting shielding devices. Two different research groups, from Aalborg University and Politecnico di Torino, tested separately various techniques to shield thermocouples from direct...

  13. Effectiveness estimation of camouflage measures with solar radiation and longwave radiation considered

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J.S. [LG Electronics Corporation (Korea); Kauh, S.K. [Seoul National University, Seoul (Korea); Yoo, H.S. [Soongsil University, Seoul (Korea)

    1998-11-01

    Camouflage measures in military purpose utilizes the apparent temperature difference between the target and background, so it is essential to develop thermal analysis program for apparent temperature predictions and to apply some camouflage measures to real military targets for camouflage purpose. In this study, a thermal analysis program including conduction, convection and radiation is developed and the validity of radiation heat transfer terms is examined. The results show that longwave radiation along with solar radiation should be included in order to predict apparent temperature as well as physical temperature exactly. Longwave emissivity variation as an effective camouflage measures is applied to a real M2 tank. From the simulation results, it is found that an effective surface treatment, such as painting of a less emissive material or camouflage, clothing, may provide a temperature similarity or a spatial similarity, resulting in an effective camouflage. (author). 12 refs., 6 figs., 1 tab.

  14. TWO STARS TWO WAYS: CONFIRMING A MICROLENSING BINARY LENS SOLUTION WITH A SPECTROSCOPIC MEASUREMENT OF THE ORBIT

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Jennifer C.; Johnson, John Asher; Eastman, Jason; Vanderburg, Andrew [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Skowron, Jan [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Gould, Andrew [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Pineda, J. Sebastian [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Howard, Andrew, E-mail: jyee@cfa.harvard.edu, E-mail: jjohnson@cfa.harvard.edu, E-mail: jason.eastman@cfa.harvard.edu, E-mail: avanderburg@cfa.harvard.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822-1839 (United States)

    2016-04-20

    Light curves of microlensing events involving stellar binaries and planetary systems can provide information about the orbital elements of the system due to orbital modulations of the caustic structure. Accurately measuring the orbit in either the stellar or planetary case requires detailed modeling of subtle deviations in the light curve. At the same time, the natural, Cartesian parameterization of a microlensing binary is partially degenerate with the microlens parallax. Hence, it is desirable to perform independent tests of the predictions of microlens orbit models using radial velocity (RV) time series of the lens binary system. To this end, we present 3.5 years of RV monitoring of the binary lens system OGLE-2009-BLG-020 L, for which Skowron et al. constrained all internal parameters of the 200–700 day orbit. Our RV measurements reveal an orbit that is consistent with the predictions of the microlens light curve analysis, thereby providing the first confirmation of orbital elements inferred from microlensing events.

  15. Measurement of the non-thermal properties of a low pressure spraying plasma by electric and spectroscopic methods

    International Nuclear Information System (INIS)

    Jung, Yong Ho

    2003-02-01

    For the case of an atmospheric plasma, the local thermodynamic equilibrium (LTE) model can be applied to plasmas at a nozzle entrance and to those on the axis of the plasma flame, but it is not easy to justify applying the LTE model to off-center plasma and to a low-pressure spraying plasma. Although the energy distribution of the electrons is assumed to be Maxwellian for the most of spraying plasmas, the non-Maxwellian distribution is possible for the case of low-pressure spaying plasma and edge plasma of atmospheric spraying plasma. In this work, the non-Maxwellian distribution of electrons was measured by using an electric probe installed on the fast scanning probe system, and non-LTE effects were measured by using the optical emission spectroscopy system. Distribution of the electrons of a low-pressure spraying plasma is observed not as Maxwellian but as bi-Maxwellian by the measurement of the single probe. Bi-Maxwellian distribution appears in the edge of a low pressure spraying plasma and seems to be due to the reduction of the collisonality by the drastic variation of the plasma density. Non-LTE characteristics of a low-pressure spraying plasma can be deuced from the measured results of the optical emission spectroscopy and is analyzed by the collisional radiative equilibrium (CRE) model, where the Maxwellian and the non-Maxwellian distributions are assumed for comparison. For the electron temperature, the results from optical emission spectroscopy were similar to the results from the single probe (3∼5 % in error)

  16. Strong Solar Control of Infrared Aurora on Jupiter: Correlation Since the Last Solar Maximum

    Science.gov (United States)

    Kostiuk, T.; Livengood, T. A.; Hewagama, T.

    2009-01-01

    Polar aurorae in Jupiter's atmosphere radiate throughout the electromagnetic spectrum from X ray through mid-infrared (mid-IR, 5 - 20 micron wavelength). Voyager IRIS data and ground-based spectroscopic measurements of Jupiter's northern mid-IR aurora, acquired since 1982, reveal a correlation between auroral brightness and solar activity that has not been observed in Jovian aurora at other wavelengths. Over nearly three solar cycles, Jupiter auroral ethane emission brightness and solar 10.7 cm radio flux and sunspot number are positively correlated with high confidence. Ethane line emission intensity varies over tenfold between low and high solar activity periods. Detailed measurements have been made using the GSFC HIPWAC spectrometer at the NASA IRTF since the last solar maximum, following the mid-IR emission through the declining phase toward solar minimum. An even more convincing correlation with solar activity is evident in these data. Current analyses of these results will be described, including planned measurements on polar ethane line emission scheduled through the rise of the next solar maximum beginning in 2009, with a steep gradient to a maximum in 2012. This work is relevant to the Juno mission and to the development of the Europa Jupiter System Mission. Results of observations at the Infrared Telescope Facility (IRTF) operated by the University of Hawaii under Cooperative Agreement no. NCC5-538 with the National Aeronautics and Space Administration, Science Mission Directorate, Planetary Astronomy Program. This work was supported by the NASA Planetary Astronomy Program.

  17. Measurement of solar proton-proton fusion neutrinos with a Soviet-American gallium experiment: Technical progress report

    International Nuclear Information System (INIS)

    Cherry, M.L.

    1989-06-01

    A gallium solar neutrino detector is sensitive to low-energy proton-proton fusion neutrinos. A flux of 70 SNU is expected in a gallium detector from the p-p reaction independent of solar model calculations. If, however, neutrino oscillations in the solar interior are responsible for the suppressed 8 B flux measured by the Homestake 37 Cl experiment, then a comparison of the gallium and chlorine results may make possible a determination of the neutrino mass difference and mixing angle. A 60-ton gallium detector is currently being constructed in the Baksan Laboratory in the Soviet Union, and should be taking data by the end of 1989

  18. Why can’t I measure the external quantum efficiency of the Ge subcell of my multijunction solar cell?

    Energy Technology Data Exchange (ETDEWEB)

    Barrigón, Enrique, E-mail: enrique.barrigon@ies-def.upm.es; Espinet-González, Pilar; Contreras, Yedileth; Rey-Stolle, Ignacio [Instituto de Energía Solar, Universidad Politécnica de Madrid ETSI de Telecomunicación, Avd. Complutense 30, 28040 Madrid (Spain)

    2015-09-28

    The measurement of the external quantum efficiency (EQE) of low bandgap subcells in a multijunction solar cell can be sometimes problematic. In particular, this paper describes a set of cases where the EQE of a Ge subcell in a conventional GaInP/GaInAs/Ge triple-junction solar cell cannot be fully measured. We describe the way to identify each case by tracing the I-V curve under the same light-bias conditions applied for the EQE measurement, together with the strategies that could be implemented to attain the best possible measurement of the EQE of the Ge subcell.

  19. Microscopic studies of a SnO2/α-Fe2O3 architectural nanocomposite using Moessbauer spectroscopic and magnetic measurements

    International Nuclear Information System (INIS)

    Hayashi, Naoaki; Muranaka, Shigetoshi; Yamamoto, Shinpei; Takano, Mikio; Zhang Dongfeng; Sun Lingdong; Yan Chunhua

    2008-01-01

    A SnO 2 /α-Fe 2 O 3 architectural nanocomposite, which was evidenced as SnO 2 nanorod arrays assembled on the surface of α-Fe 2 O 3 nanotubes in our previous study, was investigated microscopically by means of Moessbauer spectroscopic and magnetic measurements. It was found for the SnO 2 nanorods that Fe 3+ ions substituted slightly to Sn 0.998 Fe 0.002 O 2 . Concerning the α-Fe 2 O 3 tubes, the Morin transition, which was completely suppressed in the mother, SnO 2 -free α-Fe 2 O 3 nanotubes, was found to be recovered locally. We speculate that it takes place in the interface area as a result of structural modification needed for the connection with the SnO 2 nanorods. - Graphic abstract: 57 Fe Moessbauer spectrum of SnO 2 /α-Fe 2 O 3 architectural nanocomposite evidenced as SnO 2 nanorod arrays assembled on the surface of α-Fe 2 O 3 nanotubes. (I: Fe-doped SnO 2 nanorods, II: α-Fe 2 O 3 nanotubes) It was found for the SnO 2 nanorods that Fe 3+ ions substituted slightly to Sn 0.998 Fe 0.002 O 2

  20. Raman spectroscopic studies of isotopic diatomic molecules and a technique for measuring stable isotope ratios using Raman scattering

    International Nuclear Information System (INIS)

    Harney, R.C.

    1976-01-01

    A method for measuring stable isotope ratios using Raman scattering has been developed. This method consists of simultaneously counting photons scattered out of a high-intensity laser beam by different isotopically-substituted molecules. A number of studies of isotopic diatomic molecules have been made. The Q-branches of the Raman spectra of the isotopic molecules 14 N 15 N and 16 O 18 O were observed at natural abundance in nitrogen and oxygen samples. Comparison of the ratios of the intensities of the Q-branches of the major nitrogen and oxygen isotopic molecules with mass spectrometric determinations of the isotopic compositions yielded scattering cross sections of 14 N 15 N relative to 14 N 14 N and 16 O 18 O relative to 16 O 16 O. These cross section ratios differ from unity, a difference which can be explained by considering nuclear mass effects on the Franck-Condon factors of the molecular transitions. The measured intensities of the 14 N 15 N and 16 O 18 O Q-branches provided the baseline data needed to make the previously-mentioned extrapolation. High-resolution (approximately 0.15 cm -1 ) spectra of the Q-branches of 14 N 14 N and 16 O 16 O yielded a direct determination of α/sub e/ (the difference between the rotational constant in the ground and first excited vibrational states) for these molecules. The measured values are in excellent agreement with those obtained by other means. Complete Raman spectra (pure rotation, rotation-vibration, and high-resolution Q-branch) were obtained on a sample of pure 18 O 18 O. Analysis of this data yielded the molecular parameters: the equilibrium internuclear separation r/sub e/, the moment of inertia I/sub e/, and the energy parameters α/sub e/, B/sub e/, and ΔG/sub 1 / 2 /. These are in good agreement with data obtained by microwave spectroscopy

  1. Air Mass Factor Formulation for Spectroscopic Measurements from Satellites: Application to Formaldehyde Retrievals from the Global Ozone Monitoring Experiment

    Science.gov (United States)

    Palmer, Paul I.; Jacob, Daniel J.; Chance, Kelly; Martin, Randall V.; Spurr, Robert J. D.; Kurosu, Thomas P.; Bey, Isabelle; Yantosca, Robert; Fiore, Arlene; Li, Qinbin

    2004-01-01

    We present a new formulation for the air mass factor (AMF) to convert slant column measurements of optically thin atmospheric species from space into total vertical columns. Because of atmospheric scattering, the AMF depends on the vertical distribution of the species. We formulate the AMF as the integral of the relative vertical distribution (shape factor) of the species over the depth of the atmosphere, weighted by altitude-dependent coefficients (scattering weights) computed independently from a radiative transfer model. The scattering weights are readily tabulated, and one can then obtain the AMF for any observation scene by using shape factors from a three dimensional (3-D) atmospheric chemistry model for the period of observation. This approach subsequently allows objective evaluation of the 3-D model with the observed vertical columns, since the shape factor and the vertical column in the model represent two independent pieces of information. We demonstrate the AMF method by using slant column measurements of formaldehyde at 346 nm from the Global Ozone Monitoring Experiment satellite instrument over North America during July 1996. Shape factors are cumputed with the Global Earth Observing System CHEMistry (GEOS-CHEM) global 3-D model and are checked for consistency with the few available aircraft measurements. Scattering weights increase by an order of magnitude from the surface to the upper troposphere. The AMFs are typically 20-40% less over continents than over the oceans and are approximately half the values calculated in the absence of scattering. Model-induced errors in the AMF are estimated to be approximately 10%. The GEOS-CHEM model captures 50% and 60% of the variances in the observed slant and vertical columns, respectively. Comparison of the simulated and observed vertical columns allows assessment of model bias.

  2. Measurement of the Spectroscopic Quadrupole Moment for the 2+1 State in 10Be:. Testing AB Initio Calculations

    Science.gov (United States)

    Orce, J. N.; Djongolov, M.; Navratil, P.; Ball, G.; Garnsworthy, A. B.; Hackman, G.; Lassen, J.; Meissner, J.; Pearson, C. J.; Li, R.; Milovanovic, L.; Sjue, S. K. L.; Teigelhoefer, A.; Triambak, S.; Williams, S. J.; Falou, H. Al; Drake, T. E.; Andreoiu, C.; Cross, D.; Kshetri, R.; Finlay, P.; Garrett, P. E.; Leach, K. G.; Rand, E. T.; Sumithrarachchi, C. S.; Svensson, C. E.; Tardiff, E. R.; Wong, J.; Forssen, C.; Hayes, A. B.; Sarazin, F.; Stoyer, M. A.; Wu, C. Y.

    2013-03-01

    The highly efficient and segmented TIGRESS HPGe γ-ray array at TRIUMF has been used to perform a reorientation effect Coulomb excitation study of the 2+1 state at 3.368 MeV in 10Be. This is the first Coulomb excitation measurement that provides information on diagonal matrix elements for such a high lying first excited state from μ-ray data. With the availability of accurate lifetime data, a restriction on the diagonal matrix element is determined. This result is compared to a no core shell model calculation with the CD-Bonn 2000 two nucleon potential.

  3. Soft X-Ray Spectroscopic Measurements of Plasma Conditions at Early Times in ICF Experiments on OMEGA. Final technical report

    International Nuclear Information System (INIS)

    Griem, Hans R.; Elton, Raymond C.

    2000-01-01

    Our previously-reported observation of a disruptive prepulse on OMEGA, possibly as large as 1% of the extreme ultraviolet (euv) radiation measured from the main pulse, has recently been substantiated by the measurement of euv absorption spectra, prior to the main pulse. The absorption features have been identified with n=2 photoionization in aluminum atoms and ions up to Al5+. Cold aluminum is originally present as a 0.0125-um thick sealant coating applied to a neon-filled (10 atm) CH microballoon, with an euv transmission at the L-absorption edge of ∼50%. The aluminum in turn is overcoated with 2 um of Mg. The spectra which show the absorption also include continua as well as line emissions from Mg9+ to Mg11+ ions. These occur prior to the onset of laser target irradiation by at least 10 ns, and imply a prepulse irradiance of about 10 12 W/cm 2 . Since the neon and CH are opaque to euv radiation from the rear, a likely scenario is early (prepulse) vaporization of the outer Mg layer, perhaps in hot spots, followed by laser radiation transmitted through the thin Al layer, thereby heating the CH surface. This could provide an euv continuum backlighter for the aluminum that leads to the euv absorption features in various ionic species, perhaps from different points on the target surface

  4. Fluoro-apatite surface composition in aqueous solution deduced from potentiometric, electrokinetic, and solubility measurements, and spectroscopic observations

    International Nuclear Information System (INIS)

    Chairat, C.; Oelkers, E.H.; Schott, J.; Lartigue, J.E.

    2007-01-01

    The surface chemistry of fluoro-apatite in aqueous solution was investigated using electrokinetic techniques, potentiometric titrations, solubility measurements, and attenuated total reflection infrared spectroscopy. All methods indicate the formation of Ca/F depleted, P enriched altered layer via exchange reactions between H + and Ca 2+ , and OH - and F - at the fluoro-apatite (FAP) surface. Observations suggest that this leached layer has a di-calcium phosphate (CaHPO 4 ) composition and that it controls the apparent solubility of FAP. Electrokinetic measurements yield an iso-electric point value of 1 ± 0.5 consistent with a negatively charged FAP surface at pH ≥ 1. In contrast, surface titrations give an apparent pH of point of zero charge of similar to 7.7, consistent with a positively charged surface at pH ≤ 7.7. These differences are shown to stem from proton consumption by both proton exchange and dissolution reactions at the FAP surface. After taking account for these effects, FAP surface charge is shown to be negative to at least pH 4 by surface titration analysis. (authors)

  5. SphinX MEASUREMENTS OF THE 2009 SOLAR MINIMUM X-RAY EMISSION

    International Nuclear Information System (INIS)

    Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Bakała, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B.; Kuzin, S.; Farnik, F.; Reale, F.; Phillips, K. J. H.

    2012-01-01

    The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 × 10 47 cm –3 and 1.1 × 10 48 cm –3 . Comparing SphinX emission with that from the Hinode X-ray Telescope, we deduce that most of the emission is from general coronal structures rather than confined features like bright points. For one of 27 intervals of exceptionally low activity identified in the SphinX data, the Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT (0.1-2.4 keV) was less than most nearby K and M dwarfs.

  6. SphinX Measurements of the 2009 Solar Minimum X-Ray Emission

    Science.gov (United States)

    Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Kuzin, S.; Farnik, F.; Reale, F.; Phillips, K. J. H.; Bakała, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B.

    2012-06-01

    The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 × 1047 cm-3 and 1.1 × 1048 cm-3. Comparing SphinX emission with that from the Hinode X-ray Telescope, we deduce that most of the emission is from general coronal structures rather than confined features like bright points. For one of 27 intervals of exceptionally low activity identified in the SphinX data, the Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT (0.1-2.4 keV) was less than most nearby K and M dwarfs.

  7. SphinX MEASUREMENTS OF THE 2009 SOLAR MINIMUM X-RAY EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Bakala, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B. [Space Research Centre, Polish Academy of Sciences, 51-622, Kopernika 11, Wroclaw (Poland); Kuzin, S. [P. N. Lebedev Physical Institute (FIAN), Russian Academy of Sciences, Leninsky Prospect 53, Moscow 119991 (Russian Federation); Farnik, F. [Astronomical Institute, Ondrejov Observatory (Czech Republic); Reale, F. [Dipartimento di Fisica, Universita di Palermo, Palermo, Italy, and INAF, Osservatorio Astronomico di Palermo, Palermo (Italy); Phillips, K. J. H., E-mail: js@cbk.pan.wroc.pl [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom)

    2012-06-01

    The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 Multiplication-Sign 10{sup 47} cm{sup -3} and 1.1 Multiplication-Sign 10{sup 48} cm{sup -3}. Comparing SphinX emission with that from the Hinode X-ray Telescope, we deduce that most of the emission is from general coronal structures rather than confined features like bright points. For one of 27 intervals of exceptionally low activity identified in the SphinX data, the Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT (0.1-2.4 keV) was less than most nearby K and M dwarfs.

  8. A Miniaturized Seismometer for Surface Measurements in the Outer Solar System

    Science.gov (United States)

    Banerdt, W. B.; Pike, W. T.

    2001-01-01

    Seismology is a powerful tool for investigating the inner structure and dynamic processes of a planetary body. The interior structure information derived from seismic measurements is complementary to other methods of probing the subsurface (such as gravity and electromagnetics), both in terms of spatial and depth resolution and the relevant types of material properties being sensed. The propagation of seismic waves is sensitive to composition (via density and elastic parameters), temperature (via attenuation) and physical state (solid vs. liquid). In addition, the seismicity (level and distribution in space and time of seismic activity) provides information on the impact flux and tectonic forces currently active within the body. The major satellites of the outer solar system provide obvious targets for seismic investigations. In addition, small bodies, such as asteroids and comets, can also benefit from seismic measurements. We have developed an extremely small, lightweight, low-power seismometer for planetary applications which is ideally suited for use in the outer solar system. This instrument has previously been proposed and selected for use on a comet (on the Rosetta Lander, subsequently deselected for programmatic reasons) and Mars (on the NetLander mission). Additional information is contained in the original extended abstract.

  9. Spectroscopic and probe measurements of the electron temperature in the plasma of a pulse-periodic microwave discharge in argon

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, V. V., E-mail: vvandreev@mail.ru; Vasileska, I., E-mail: ivonavasileska@yahoo.com; Korneeva, M. A., E-mail: korneevama@mail.ru [Peoples’ Friendship University of Russia (Russian Federation)

    2016-07-15

    A pulse-periodic 2.45-GHz electron-cyclotron resonance plasma source on the basis of a permanent- magnet mirror trap has been constructed and tested. Variations in the discharge parameters and the electron temperature of argon plasma have been investigated in the argon pressure range of 1 × 10{sup –4} to 4 × 10{sup –3} Torr at a net pulsed input microwave power of up to 600 W. The plasma electron temperature in the above ranges of gas pressures and input powers has been measured by a Langmuir probe and determined using optical emission spectroscopy (OES) from the intensity ratios of spectral lines. The OES results agree qualitatively and quantitatively with the data obtained using the double probe.

  10. Mass spectroscopic measurements in the plasma edge of the W7-AS stellarator and their statistical analysis

    International Nuclear Information System (INIS)

    Zebisch, P.; Grigull, P.; Dose, V.; Taglauer, E.

    1997-01-01

    During the W7-AS operation period in autumn 1995 sniffer probe measurements were made for more than 800 discharges. The H/D ratio during deuterium discharges was determined showing HD and H 2 desorption from the walls even after fresh boronization. For these discharges the loading of the walls with deuterium could be observed. In the higher mass range the development of large amounts of hydrocarbons was observed at the beginning of the discharges with neutral beam injection. To evaluate the large amount of data recorded here (order of 10000 mass spectra), appropriate mathematical methods are required. It is shown that group analysis can be applied to distinguish certain sets of discharges and to derive useful mean values. (orig.)

  11. A miniaturized laser-ablation mass spectrometer for in-situ measurements of isotope composition on solar body surfaces

    Science.gov (United States)

    Riedo, A.; Meyer, S.; Tulej, M.; Neuland, M.; Bieler, A.; Iakovleva, M.; Wurz, P.

    2012-04-01

    The in-situ analysis of extraterrestrial material onboard planetary rovers and landers is of considerable interest for future planetary space missions. Due to the low detection sensitivity of spectroscopic instruments, e.g. α-particle X-ray, γ-ray or neutron spectrometers, it is frequently possible to measure only major/minor elements in extraterrestrial materials. Nevertheless, the knowledge of minor/trace elements is of considerable interest to cosmochemistry. Chemistry puts constraints on the origin of solar system and its evolution enabling also a deeper inside to planetary transformation processes (e.g. volcanic surface alteration, space weathering). The isotopes play special role in analysis of the origin and transformation of planetary matter. They are robust tracers of the early events because their abundances are less disturbed as the elemental once. Nevertheless, if the isotope abundance ratios are fractionated, the underlying chemical and physical processes can be then encoded from the variations of abundance ratios. A detailed analysis of isotopic patterns of radiogenic elements can allow age dating of minerals and temporal evolution of planetary matter. High accuracy and sensitive measurements of isotopic pattern of bio-relevant elements, i.e., sulfur, found on planetary surfaces can be helpful for the identification of possible past and present extraterrestrial life in terms of biomarker identification. Our group has designed a self-optimizing miniaturized laser ablation time-of-flight mass spectrometer (LMS) for in situ planetary measurements (Wurz et al., 2012; Rohner et al., 2003). Initial studies utilizing IR laser radiation for ablation, atomization and ionization of solid materials indicated a high instrumental performance in terms of sensitivity and mass resolution (Tulej et al., 2011). Current studies are conducted with a UV radiation and a high spatial resolution is achieved by focussing the laser beam to 20µm spots onto the sample. The

  12. Comparison of several databases of downward solar daily irradiation data at ocean surface with PIRATA measurements

    Science.gov (United States)

    Trolliet, Mélodie; Wald, Lucien

    2017-04-01

    The solar radiation impinging at sea surface is an essential variable in climate system. There are several means to assess the daily irradiation at surface, such as pyranometers aboard ship or on buoys, meteorological re-analyses and satellite-derived databases. Among the latter, assessments made from the series of geostationary Meteosat satellites offer synoptic views of the tropical and equatorial Atlantic Ocean every 15 min with a spatial resolution of approximately 5 km. Such Meteosat-derived databases are fairly recent and the quality of the estimates of the daily irradiation must be established. Efforts have been made for the land masses and must be repeated for the Atlantic Ocean. The Prediction and Research Moored Array in the Tropical Atlantic (PIRATA) network of moorings in the Tropical Atlantic Ocean is considered as a reference for oceanographic data. It consists in 17 long-term Autonomous Temperature Line Acquisition System (ATLAS) buoys equipped with sensors to measure near-surface meteorological and subsurface oceanic parameters, including downward solar irradiation. Corrected downward solar daily irradiation from PIRATA were downloaded from the NOAA web site and were compared to several databases: CAMS RAD, HelioClim-1, HelioClim-3 v4 and HelioClim-3 v5. CAMS-RAD, the CAMS radiation service, combines products of the Copernicus Atmosphere Monitoring Service (CAMS) on gaseous content and aerosols in the atmosphere together with cloud optical properties deduced every 15 min from Meteosat imagery to supply estimates of the solar irradiation. Part of this service is the McClear clear sky model that provides estimates of the solar irradiation that should be observed in cloud-free conditions. The second and third databases are HelioClim-1 and HelioClim-3 v4 that are derived from Meteosat images using the Heliosat-2 method and the ESRA clear sky model, based on the Linke turbidity factor. HelioClim-3 v5 is the fourth database and differs from v4 by the

  13. Determination of effects of reverse bias on the efficiency of dye solar cells with the aid of spectroscopic and impedance studies

    CSIR Research Space (South Africa)

    Le Roux, Lukas J

    2010-09-01

    Full Text Available this cell in reverse bias. Although the work is focussed on the chemical stability of the dye, various techniques were employed to determine the physical changes in the cell. This presentation shows how electrochemical and impedance measurements (Nyquist...

  14. Satellite observations of energetic electron precipitation during the 1979 solar eclipse and comparisons with rocket measurements

    Science.gov (United States)

    Gaines, E. E.; Imhof, W. L.; Voss, H. D.; Reagan, J. B.

    1983-07-01

    During the solar eclipse of 26 February 1979, the P78-1 satellite passed near Red Lake, Ontario, at an altitude of about 600 km. On two consecutive orbits spanning the time of total eclipse, energetic electrons were measured with two silicon solid state detector spectrometers having excellent energy and angular resolution. Significant fluxes of precipitating electrons were observed near the path of totality. Comparisons of flux intensities and energy spectra with those measured from a Nike Orion and two Nike Tomahawk rockets launched near Red Lake before and during total eclipse give good agreement and indicate that the electron precipitation was relatively uniform for more than an hour and over a broad geographical area.

  15. Satellite observations of energetic electron precipitation during the 1979 solar eclipse and comparisons with rocket measurements

    International Nuclear Information System (INIS)

    Gaines, E.E.; Imhof, W.L.; Voss, H.D.; Reagan, J.B.

    1983-01-01

    During the solar eclipse of 26 February 1979, the P78-1 satellite passed near Red Lake, Ontario, at an altitude of approx. 600 km. On two consecutive orbits spanning the time of total eclipse, energetic electrons were measured with two silicon solid state detector spectrometers having excellent energy and angular resolution. Significant fluxes of precipitating electrons were observed near the path of totality. Comparisons of flux intensities and energy spectra with those measured from a Nike Orion and two Nike Tomahawk rockets launched near Red Lake before and during total eclipse give good agreement and indicate that the electron precipitation was relatively uniform for more than an hour and over a broad geographical area. (author)

  16. Accurate measurements of solar spectral irradiance between 4000-10000 cm-1

    Science.gov (United States)

    Elsey, J.; Coleman, M. D.; Gardiner, T.; Shine, K. P.

    2017-12-01

    The near-infrared solar spectral irradiance (SSI) is an important input into simulations of weather and climate; the distribution of energy throughout this region of the spectrum influences atmospheric heating rates and the global hydrological cycle through absorption and scattering by water vapour. Current measurements by a mixture of ground-based and space-based instruments show differences of around 10% in the 4000-7000 cm-1 region, with no resolution to this controversy in sight. This work presents observations of SSI taken using a ground-based Fourier Transform spectrometer between 4000-10000 cm-1 at a field site in Camborne, UK, with particular focus on a rigorously defined uncertainty budget. While there is good agreement between this work and the commonly-used ATLAS3 spectrum between 7000-10000 cm-1, the SSI is systematically lower by 10% than ATLAS3 between 4000-7000 cm-1, with no overlap within the k = 2 measurement uncertainties.

  17. Laser-induced carbon plasma emission spectroscopic measurements on solid targets and in gas-phase optical breakdown

    International Nuclear Information System (INIS)

    Nemes, Laszlo; Keszler, Anna M.; Hornkohl, James O.; Parigger, Christian

    2005-01-01

    We report measurements of time- and spatially averaged spontaneous-emission spectra following laser-induced breakdown on a solid graphite/ambient gas interface and on solid graphite in vacuum, and also emission spectra from gas-phase optical breakdown in allene C3H4 and helium, and in CO2 and helium mixtures. These emission spectra were dominated by CII (singly ionized carbon), CIII (doubly ionized carbon), hydrogen Balmer beta (H b eta), and Swan C2 band features. Using the local thermodynamic equilibrium and thin plasma assumptions, we derived electron number density and electron temperature estimates. The former was in the 1016 cm -3 range, while the latter was found to be near 20000 K. In addition, the vibration-rotation temperature of the Swan bands of the C2 radical was determined to be between 4500 and 7000 K, using an exact theoretical model for simulating diatomic emission spectra. This temperature range is probably caused by the spatial inhomogeneity of the laser-induced plasma plume. Differences are pointed out in the role of ambient CO2 in a solid graphite target and in gas-phase breakdown plasma

  18. Spectroscopic methods for aqueous cyclodextrin inclusion complex binding measurement for 1,4-dioxane, chlorinated co-contaminants, and ozone

    Science.gov (United States)

    Khan, Naima A.; Johnson, Michael D.; Carroll, Kenneth C.

    2018-03-01

    Recalcitrant organic contaminants, such as 1,4-dioxane, typically require advanced oxidation process (AOP) oxidants, such as ozone (O3), for their complete mineralization during water treatment. Unfortunately, the use of AOPs can be limited by these oxidants' relatively high reactivities and short half-lives. These drawbacks can be minimized by partial encapsulation of the oxidants within a cyclodextrin cavity to form inclusion complexes. We determined the inclusion complexes of O3 and three common co-contaminants (trichloroethene, 1,1,1-trichloroethane, and 1,4-dioxane) as guest compounds within hydroxypropyl-β-cyclodextrin. Both direct (ultraviolet or UV) and competitive (fluorescence changes with 6-p-toluidine-2-naphthalenesulfonic acid as the probe) methods were used, which gave comparable results for the inclusion constants of these species. Impacts of changing pH and NaCl concentrations were also assessed. Binding constants increased with pH and with ionic strength, which was attributed to variations in guest compound solubility. The results illustrate the versatility of cyclodextrins for inclusion complexation with various types of compounds, binding measurement methods are applicable to a wide range of applications, and have implications for both extraction of contaminants and delivery of reagents for treatment of contaminants in wastewater or contaminated groundwater.

  19. The UV-A and visible solar irradiance spectrum: inter-comparison of absolutely calibrated, spectrally medium resolution solar irradiance spectra from balloon- and satellite-borne measurements

    Directory of Open Access Journals (Sweden)

    W. Gurlit

    2005-01-01

    Full Text Available Within the framework of the ENVISAT/-SCIAMACHY satellite validation, solar irradiance spectra are absolutely measured at moderate resolution in the UV/visible spectral range (in the UV from 316.7-418 nm and the visible from 400-652 nm at a full width half maximum resolution of 0.55 nm and 1.48 nm, respectively from aboard the azimuth-controlled LPMA/DOAS balloon gondola at around 32 km balloon float altitude. After accounting for the atmospheric extinction due to Rayleigh scattering and gaseous absorption (O3 and NO2, the measured solar spectra are compared with previous observations. Our solar irradiance spectrum perfectly agrees within +0.03% with the re-calibrated Kurucz et al. (1984 solar spectrum (Fontenla et al., 1999, called MODTRAN 3.7 in the visible spectral range (415-650 nm, but it is +2.1% larger in the (370-415 nm wavelength interval, and -4% smaller in the UV-A spectral range (316.7-370 nm, when the Kurucz spectrum is convolved to the spectral resolution of our instrument. Similar comparisons of the SOLSPEC (Thuillier et al., 1997, 1998a, b and SORCE/SIM (Harder et al., 2000 solar spectra with MODTRAN 3.7 confirms our findings with the values being -0.5%, +2%, and -1.4% for SOLSPEC -0.33%, -0.47%, and -6.2% for SORCE/SIM, respectively. Comparison of the SCIAMACHY solar spectrum from channels 1 to 4 (- re-calibrated by the University of Bremen - with MODTRAN 3.7 indicates an agreement within -0.4% in the visible spectral range (415-585 nm, -1.6% within the 370-415 nm, and -5.7% within 325-370 nm wavelength interval, in agreement with the results of the other sensors. In agreement with findings of Skupin et al. (2002 our study emphasizes that the present ESA SCIAMACHY level 1 calibration is systematically +15% larger in the considered wavelength intervals when compared to all available other solar irradiance measurements.

  20. On the intrinsic timescales of temporal variability in measurements of the surface solar radiation

    Science.gov (United States)

    Bengulescu, Marc; Blanc, Philippe; Wald, Lucien

    2018-01-01

    This study is concerned with the intrinsic temporal scales of the variability in the surface solar irradiance (SSI). The data consist of decennial time series of daily means of the SSI obtained from high-quality measurements of the broadband solar radiation impinging on a horizontal plane at ground level, issued from different Baseline Surface Radiation Network (BSRN) ground stations around the world. First, embedded oscillations sorted in terms of increasing timescales of the data are extracted by empirical mode decomposition (EMD). Next, Hilbert spectral analysis is applied to obtain an amplitude-modulation-frequency-modulation (AM-FM) representation of the data. The time-varying nature of the characteristic timescales of variability, along with the variations in the signal intensity, are thus revealed. A novel, adaptive null hypothesis based on the general statistical characteristics of noise is employed in order to discriminate between the different features of the data, those that have a deterministic origin and those being realizations of various stochastic processes. The data have a significant spectral peak corresponding to the yearly variability cycle and feature quasi-stochastic high-frequency variability components, irrespective of the geographical location or of the local climate. Moreover, the amplitude of this latter feature is shown to be modulated by variations in the yearly cycle, which is indicative of nonlinear multiplicative cross-scale couplings. The study has possible implications on the modeling and the forecast of the surface solar radiation, by clearly discriminating the deterministic from the quasi-stochastic character of the data, at different local timescales.

  1. High Time-Resolved Kinetic Temperatures of Solar Wind Minor Ions Measured with SOHO/CELIAS/CTOF

    Science.gov (United States)

    Janitzek, N. P.; Berger, L.; Drews, C.; Wimmer-Schweingruber, R. F.

    2017-12-01

    Solar wind heavy ions with an atomic number Z > 2 are referred to as minor ions since they represent a fraction of less than one percent of all solar wind ions. They can be therefore regarded as test particles, only reacting to but not driving the dynamics of the solar wind plasma, which makes them a unique diagnostic tool for plasma wave phenomena both in the solar atmosphere and the extended heliosphere. In the past, several studies have investigated the kinetic temperatures of minor ions, but due to low counting statistics these studies are based on ion velocity distribution functions (VDFs) recorded over time periods of several hours. The Charge Time-Of-Flight (CTOF) mass spectrometer as part of the Charge, ELement and Isotope Analysis System (CELIAS) onboard the SOlar and Heliospheric Observatory (SOHO) provides solar wind heavy ion 1D radial VDFs with excellent charge state separation, an unprecedented cadence of 5 minutes and very high counting statistics, exceeding similar state-of-the-art instruments by a factor of ten. In our study, based on CTOF measurements at Langrangian point L1 between DOY 150 and DOY 220 in 1996, we investigate systematically the influence of the VDF time resolution on the derived kinetic temperatures for solar wind silicon and iron ions. The selected ion set spans a wide range of mass-per-charge from 3 amu/e heavy ions with ion-cyclotron waves.

  2. Zenith: A Radiosonde Detector for Rapid-Response Ionizing Atmospheric Radiation Measurements During Solar Particle Events

    Science.gov (United States)

    Dyer, A. C. R.; Ryden, K. A.; Hands, A. D. P.; Dyer, C.; Burnett, C.; Gibbs, M.

    2018-03-01

    Solar energetic particle events create radiation risks for aircraft, notably single-event effects in microelectronics along with increased dose to crew and passengers. In response to this, some airlines modify their flight routes after automatic alerts are issued. At present these alerts are based on proton flux measurements from instruments onboard satellites, so it is important that contemporary atmospheric radiation measurements are made and compared. This paper presents the development of a rapid-response system built around the use of radiosondes equipped with a radiation detector, Zenith, which can be launched from a Met Office weather station after significant solar proton level alerts are issued. Zenith is a compact, battery-powered solid-state radiation monitor designed to be connected to a Vaisala RS-92 radiosonde, which transmits all data to a ground station as it ascends to an altitude of 33 km. Zenith can also be operated as a stand-alone detector when connected to a laptop, providing real-time count rates. It can also be adapted for use on unmanned aerial vehicles. Zenith has been flown on the Met Office Civil Contingency Aircraft, taken to the European Organization for Nuclear Research-EU high energy Reference Field facility for calibration and launched on a meteorological balloon at the Met Office's weather station in Camborne, Cornwall, UK. During this sounding, Zenith measured the Pfotzer-Regener maximum to be at an altitude of 18-20 km where the count rate was measured to be 1.15 c s-1 cm-2 compared to 0.02 c s-1 cm-2 at ground level.

  3. Broadband time-resolved elliptical crystal spectrometer for X-ray spectroscopic measurements in laser-produced plasmas

    International Nuclear Information System (INIS)

    Wang Rui-Rong; Jia Guo; Fang Zhi-Heng; Wang Wei; Meng Xiang-Fu; Xie Zhi-Yong; Zhang Fan

    2014-01-01

    The X-ray spectrometer used in high-energy-density plasma experiments generally requires both broad X-ray energy coverage and high temporal, spatial, and spectral resolutions for overcoming the difficulties imposed by the X-ray background, debris, and mechanical shocks. By using an elliptical crystal together with a streak camera, we resolve this issue at the SG-II laser facility. The carefully designed elliptical crystal has a broad spectral coverage with high resolution, strong rejection of the diffuse and/or fluorescent background radiation, and negligible source broadening for extended sources. The spectra that are Bragg reflected (23° < θ < 38°) from the crystal are focused onto a streak camera slit 18 mm long and about 80 μm wide, to obtain a time-resolved spectrum. With experimental measurements, we demonstrate that the quartz(1011) elliptical analyzer at the SG-II laser facility has a single-shot spectral range of (4.64–6.45) keV, a typical spectral resolution of E/ΔE = 560, and an enhanced focusing power in the spectral dimension. For titanium (Ti) data, the lines of interest show a distribution as a function of time and the temporal variations of the He-α and Li-like Ti satellite lines and their spatial profiles show intensity peak red shifts. The spectrometer sensitivity is illustrated with a temporal resolution of better than 25 ps, which satisfies the near-term requirements of high-energy-density physics experiments. (atomic and molecular physics)

  4. Mid-infrared spectroscopic investigation

    International Nuclear Information System (INIS)

    Walter, L.; Vergo, N.; Salisbury, J.W.

    1987-01-01

    Mid-infrared spectroscopic research efforts are discussed. The development of a new instrumentation to permit advanced measurements in the mid-infrared region of the spectrum, the development of a special library of well-characterized mineral and rock specimens for interpretation of remote sensing data, and cooperative measurements of the spectral signatures of analogues of materials that may be present on the surfaces of asteroids, planets or their Moons are discussed

  5. Measurements on a PV solar pump equipped with a piston pump with a matching valve

    NARCIS (Netherlands)

    Smulders, P.T.; Ten Thije O.G. Boonkkamp, J.; Borg, van der N.J.C.M.; Beek, van M.

    1997-01-01

    The work on a simple high efficient solar pump equipped with a piston pump with a matching valve, reported at the Solar World Congress in Budapest, has been continued. Quasi-static and dynamic models of the solar pump have been derived with which the operation of the system is simulated. A test rig

  6. High resolution measurements of solar induced chlorophyll fluorescence in the Fraunhofer oxigen bands

    Science.gov (United States)

    Mazzoni, M.; Agati, G.; Cecchi, G.; Toci, G.; Mazzinghi, P.

    2017-11-01

    Spectra of solar radiance reflected by leaves close to the Fraunhofer bands show the net contribution of chlorophyll fluorescence emission which adds to the reflected solar spectra. In a laboratory experiment, a low stray light, high resolution, 0.85 m double monochromator was used to filter radiation living leaves still attached to the plant in correspondence of the 687 nm and 760 nm O2 absorption bands. Reference spectra from a non fluorescent white reference were also acquired. Acquisition was performed by a Microchannel plate (MCP) intensified diode array with 512 elements. A fit of the spectral data outside the absorption lines allowed to retrieve the spectral base-line as a function of wavelength for the reference panel and the leaf. Reflectance functions were determined extending the Plascyck equation system to all the resolved lines of the oxygen absorption bands and using the base-lines for the continuum values. Fluorescence was deduced from the same equation system, using both the measured leaf and reference radiance spectra and the leaf reflectance fitting function.

  7. Measures for the Diffusion of Solar PV are Aligned in Technology Action Plans for Six Countries in Africa

    DEFF Research Database (Denmark)

    Nygaard, Ivan; Hansen, Ulrich Elmer; Pedersen, Mathilde Brix

    2014-01-01

    African countries from 2010 to 2013, dedicated government committees have prioritized climate change mitigation technologies and developed action plans for the diffusion of the selected technologies. The project results show that solar PV is high on the agenda in Africa. Six out of ten countries...... in the region prioritized solar PV, and action plans for the diffusion of solar home systems were put forward in Cote d’Ivoire, Kenya, Mali and Senegal, while the implementation of grid-connected systems was proposed in Rwanda, Mali and Senegal. The project reports and technology action plans prepared...... in these six countries are used as the basis for comparing how solar PV is perceived in these countries and how policy measures enabling environmental adjustments and investment programmes are being planned to promote diffusion of the technology in these different contexts....

  8. Lifetime measurements and oscillator strengths in singly ionized scandium and the solar abundance of scandium

    Science.gov (United States)

    Pehlivan Rhodin, A.; Belmonte, M. T.; Engström, L.; Lundberg, H.; Nilsson, H.; Hartman, H.; Pickering, J. C.; Clear, C.; Quinet, P.; Fivet, V.; Palmeri, P.

    2017-12-01

    The lifetimes of 17 even-parity levels (3d5s, 3d4d, 3d6s and 4p2) in the region 57 743-77 837 cm-1 of singly ionized scandium (Sc II) were measured by two-step time-resolved laser induced fluorescence spectroscopy. Oscillator strengths of 57 lines from these highly excited upper levels were derived using a hollow cathode discharge lamp and a Fourier transform spectrometer. In addition, Hartree-Fock calculations where both the main relativistic and core-polarization effects were taken into account were carried out for both low- and high-excitation levels. There is a good agreement for most of the lines between our calculated branching fractions and the measurements of Lawler & Dakin in the region 9000-45 000 cm-1 for low excitation levels and with our measurements for high excitation levels in the region 23 500-63 100 cm-1. This, in turn, allowed us to combine the calculated branching fractions with the available experimental lifetimes to determine semi-empirical oscillator strengths for a set of 380 E1 transitions in Sc II. These oscillator strengths include the weak lines that were used previously to derive the solar abundance of scandium. The solar abundance of scandium is now estimated to logε⊙ = 3.04 ± 0.13 using these semi-empirical oscillator strengths to shift the values determined by Scott et al. The new estimated abundance value is in agreement with the meteoritic value (logεmet = 3.05 ± 0.02) of Lodders, Palme & Gail.

  9. Measurement of the profile and intensity of the solar He I lambda 584-A resonance line

    Science.gov (United States)

    Maloy, J. O.; Hartmann, U. G.; Judge, D. L.; Carlson, R. W.

    1978-01-01

    The intensity and profile of the helium resonance line at 584 A from the entire disk of the sun was investigated by using a rocket-borne helium-filled spectrometer and a curve-of-growth technique. The line profile was found to be accurately represented by a Gaussian profile with full width at half maximum of 122 + or - 10 mA, while the integrated intensity was measured to be 2.6 + or - 1.3 billion photons/s per sq cm at solar activity levels of F(10.7) = 90.8 x 10 to the -22nd per sq m/Hz and Rz = 27. The measured line width is in good agreement with previous spectrographic measurements, but the integrated intensity is larger than most previous photoelectric measurements. However, the derived line center flux of 20 + or - 10 billion photons/s per sq cm/A is in good agreement with values inferred from airglow measurements.

  10. Advancing Solar Irradiance Measurement for Climate-Related Studies: Accurate Constraint on Direct Aerosol Radiative Effect (DARE)

    Science.gov (United States)

    Tsay, Si-Chee; Ji, Q. Jack

    2011-01-01

    Earth's climate is driven primarily by solar radiation. As summarized in various IPCC reports, the global average of radiative forcing for different agents and mechanisms, such as aerosols or CO2 doubling, is in the range of a few W/sq m. However, when solar irradiance is measured by broadband radiometers, such as the fleet of Eppley Precision Solar Pyranometers (PSP) and equivalent instrumentation employed worldwide, the measurement uncertainty is larger than 2% (e.g., WMO specification of pyranometer, 2008). Thus, out of the approx. 184 W/sq m (approx.263 W/sq m if cloud-free) surface solar insolation (Trenberth et al. 2009), the measurement uncertainty is greater than +/-3.6 W/sq m, overwhelming the climate change signals. To discern these signals, less than a 1 % measurement uncertainty is required and is currently achievable only by means of a newly developed methodology employing a modified PSP-like pyranometer and an updated calibration equation to account for its thermal effects (li and Tsay, 2010). In this talk, we will show that some auxiliary measurements, such as those from a collocated pyrgeometer or air temperature sensors, can help correct historical datasets. Additionally, we will also demonstrate that a pyrheliometer is not free of the thermal effect; therefore, comparing to a high cost yet still not thermal-effect-free "direct + diffuse" approach in measuring surface solar irradiance, our new method is more economical, and more likely to be suitable for correcting a wide variety of historical datasets. Modeling simulations will be presented that a corrected solar irradiance measurement has a significant impact on aerosol forcing, and thus plays an important role in climate studies.

  11. Cross-Calibrating Sunspot Magnetic Field Strength Measurements from the McMath-Pierce Solar Telescope and the Dunn Solar Telescope

    Science.gov (United States)

    Watson, Fraser T.; Beck, Christian; Penn, Matthew J.; Tritschler, Alexandra; Pillet, Valentín Martinez; Livingston, William C.

    2015-11-01

    In this article we describe a recent effort to cross-calibrate data from an infrared detector at the McMath-Pierce Solar Telescope and the Facility InfraRed Spectropolarimeter (FIRS) at the Dunn Solar Telescope. A synoptic observation program at the McMath-Pierce has measured umbral magnetic field strengths since 1998, and this data set has recently been compared with umbral magnetic field observations from SOHO/MDI and SDO/HMI. To further improve on the data from McMath-Pierce, we compared the data with measurements taken at the Dunn Solar Telescope with far greater spectral resolution than has been possible with space instrumentation. To minimise potential disruption to the study, concurrent umbral measurements were made so that the relationship between the two datasets can be most accurately characterised. We find that there is a strong agreement between the umbral magnetic field strengths recorded by each instrument, and we reduced the FIRS data in two different ways to successfully test this correlation further.

  12. The absorption spectrum of water vapor in the 2.2 μm transparency window: High sensitivity measurements and spectroscopic database

    International Nuclear Information System (INIS)

    Campargue, A.; Mikhailenko, S.N.; Vasilchenko, S.; Reynaud, C.; Béguier, S.; Čermák, P.; Mondelain, D.; Kassi, S.; Romanini, D.

    2017-01-01

    The weak absorption spectrum of water vapor in the important 2.2 μm transparency window is investigated with very high sensitivity. Overall, about 400 absorption lines were measured by Cavity Ring Down Spectroscopy (CRDS) and Optical-Feedback-Cavity Enhanced Laser Spectroscopy (OF-CEAS) in five spectral intervals: 4248.2–4257.3, 4298.4–4302.6, 4336.8.5-4367.5, 4422.4-4441.2 and 4514.6-4533.7 cm"−"1. The achieved sensitivity of the recordings (noise equivalent absorption, α_m_i_n, on the order of 2×10"−"1"0 cm"−"1) allowed detecting transitions with intensity values down to 1×10"−"2"8 cm/molecule, more than one order of magnitude better than previous studies by Fourier Transform spectroscopy. The rovibrational assignment was performed on the basis of variational calculations and of previously determined empirical energy values. Most of the newly assigned lines correspond to transitions of the ν_1, ν_3 and 3ν_2 bands of H_2"1"7O in natural isotopic abundance. Fourteen energy levels of H_2"1"7O, H_2"1"8O and HD"1"8O are newly determined. An accurate and complete spectroscopic database is constructed for natural water in the 4190–4550 cm"−"1 region (2.39–2.20 µm). The list includes about 4500 transitions with intensity greater than 1×10"−"2"9 cm/molecule, for the six most abundant isotopologues in natural isotopic abundance. Line positions were obtained by difference of empirical energy values determined from literature data and complemented with the present CRDS results. The list is made mostly complete by including weak transitions not yet detected, with positions calculated from empirical levels and variational intensities. The variational intensities computed by a collaboration between the University College London and the Institute of Applied Physics in Nizhny Novgorod are found to improve significantly previous results by Schwenke and Partridge. Examples of comparison of the constructed line list to CRDS spectra and to simulations

  13. Multi-pass spectroscopic ellipsometry

    International Nuclear Information System (INIS)

    Stehle, Jean-Louis; Samartzis, Peter C.; Stamataki, Katerina; Piel, Jean-Philippe; Katsoprinakis, George E.; Papadakis, Vassilis; Schimowski, Xavier; Rakitzis, T. Peter; Loppinet, Benoit

    2014-01-01

    Spectroscopic ellipsometry is an established technique, particularly useful for thickness measurements of thin films. It measures polarization rotation after a single reflection of a beam of light on the measured substrate at a given incidence angle. In this paper, we report the development of multi-pass spectroscopic ellipsometry where the light beam reflects multiple times on the sample. We have investigated both theoretically and experimentally the effect of sample reflectivity, number of reflections (passes), angles of incidence and detector dynamic range on ellipsometric observables tanΨ and cosΔ. The multiple pass approach provides increased sensitivity to small changes in Ψ and Δ, opening the way for single measurement determination of optical thickness T, refractive index n and absorption coefficient k of thin films, a significant improvement over the existing techniques. Based on our results, we discuss the strengths, the weaknesses and possible applications of this technique. - Highlights: • We present multi-pass spectroscopic ellipsometry (MPSE), a multi-pass approach to ellipsometry. • Different detectors, samples, angles of incidence and number of passes were tested. • N passes improve polarization ratio sensitivity to the power of N. • N reflections improve phase shift sensitivity by a factor of N. • MPSE can significantly improve thickness measurements in thin films

  14. Development of a very fast spectral response measurement system for analysis of hydrogenated amorphous silicon solar cells and modules

    International Nuclear Information System (INIS)

    Rodríguez, J.A.; Fortes, M.; Alberte, C.; Vetter, M.; Andreu, J.

    2013-01-01

    Highlights: ► Spectral response equipment for measuring a-Si:H solar cells in a few seconds. ► Equipment based on 16 LEDs with simultaneous illumination of the solar cell. ► The current generated by each LED is analyzed by a Fast Fourier Transform. ► Cheap equipment without lock-in technology for the current measurement. ► Measurement error vs. conventional measurement less than 1% in J sc . - Abstract: An important requirement for a very fast spectral response measurement system is the simultaneous illumination of the solar cell at multiple well defined wavelengths. Nowadays this can be done by means of light emitting diodes (LEDs) available for a multitude of wavelengths. For the purpose to measure the spectral response (SR) of amorphous silicon solar cells a detailed characterization of LEDs emitting in the wavelength range from 300 nm to 800 nm was performed. In the here developed equipment the LED illumination is modulated in the frequency range from 100 Hz to 200 Hz and the current generated by each LED is analyzed by a Fast Fourier Transform (FFT) to determine the current component corresponding to each wavelength. The equipment provides a signal to noise ratio of 2–4 orders of magnitude for individual wavelengths resulting in a precise measurement of the SR over the whole wavelength range. The difference of the short circuit current determined from the SR is less than 1% in comparison to a conventional system with monochromator.

  15. The cross section of 3He(3He,2p)4He measured at solar energies

    International Nuclear Information System (INIS)

    Junker, M.; Arpesella, C.; Bellotti, E.; Broggini, C.; Corvisiero, P.; D'Alessandro, A.; Fiorentini, G.; Fubini, A.; Gervino, G.; Greife, U.; Gustavino, C.; Lambert, J.; Prati, P.; Rodney, W.S.; Rolfs, C.; Trautvetter, H.P.; Zavatarelli, S.

    1999-01-01

    We report on the status of the 3 He( 3 He,2p) 4 He experiment at the underground accelerator facility LUNA (Gran Sasso). The lowest projectile energies for the measured cross section correspond already to energies below the center of the solar Gamow peak (E 0 =22 keV). The data provide no evidence for the existence of a hypothetical resonance in the energy range investigated. Although no extrapolation is needed anymore (except for energies at the low-energy tail of the Gamow peak), the data must be corrected for the effects of electron screening, clearly observed the first time for the 3 He( 3 He,2p) 4 He reaction. The effects are however larger than expected and not understood, leading presently to the largest uncertainty on the quoted S(0) value for bare nuclides (= 5.40 MeVb)

  16. Characterizing the solar reflection from wildfire smoke plumes using airborne multiangle measurements

    Science.gov (United States)

    Gatebe, C. K.; Varnai, T.; Gautam, R.; Poudyal, R.; Singh, M. K.

    2016-12-01

    To help better understand forest fire smoke plumes, this study examines sunlight reflected from plumes that were observed over Canada during the ARCTAS campaign in summer 2008. In particular, the study analyzes multiangle and multispectral measurements of smoke scattering by the airborne Cloud Absorption Radiometer (CAR). In combination with other in-situ and remote sensing information and radiation modeling, CAR data is used for characterizing the radiative properties and radiative impact of smoke particles—which inherently depend on smoke particle properties that influence air quality. In addition to estimating the amount of reflected and absorbed sunlight, the work includes using CAR data to create spectral and broadband top-of-atmosphere angular distribution models (ADMs) of solar radiation reflected by smoke plumes, and examining the sensitivity of such angular models to scene parameters. Overall, the results help better understand the radiative properties and radiative effects of smoke particles, and are anticipated to help better interpret satellite data on smoke plumes.

  17. Electron and hole drift mobility measurements on methylammonium lead iodide perovskite solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Maynard, Brian; Long, Qi; Schiff, Eric A. [Department of Physics, Syracuse University, Syracuse, New York 13244 (United States); Yang, Mengjin; Zhu, Kai [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Kottokkaran, Ranjith; Abbas, Hisham; Dalal, Vikram L. [Iowa State University, Ames, Iowa 50011 (United States)

    2016-04-25

    We report nanosecond domain time-of-flight measurements of electron and hole photocarriers in methylammonium lead iodide perovskite solar cells. The mobilities ranged from 0.06 to 1.4 cm{sup 2}/Vs at room temperature, but there is little systematic difference between the two carriers. We also find that the drift mobilities are dispersive (time-dependent). The dispersion parameters are in the range of 0.4–0.7, and they imply that terahertz domain mobilities will be much larger than nanosecond domain mobilities. The temperature-dependences of the dispersion parameters are consistent with confinement of electron and hole transport to fractal-like spatial networks within nanoseconds of their photogeneration.

  18. Design, Construction And Characterization Of A Pyranometer For Measuring Global Solar Radiation

    International Nuclear Information System (INIS)

    Onah, D.U; Osuji, R.O.

    2004-01-01

    Due to cost and stringent importation requirement, we have designed and constructed a Pyranometer from locally available materials. The constructed Pyranometer was calibrated against a standard calibrated Eppley pyranometer model PSP17190F3. the two pyranometers were used simultaneously in measuring global solar radiation at Nsukka, Nigeria on latitude 6.8 degree North and longitude 7.35 degree East, located 488m above sea level. The average insolation for each of the two typical clear sky days were 3.221KW per square metre and 3.266KW per square metre. The maximum insolation obtained with the constructed pyranometer was 965.5 W per square metre on 16/1/03. The corresponding insolation obtained with the reference Eppley pyranometre on the same day was 1087.5W per square metre. We are happy to remark that there was not significant difference between the performances of the constructed pyranometer and the standard Eppley pyranometer

  19. A comparison of synthetic and measured solar continuum intensities and limb darkening coefficients

    International Nuclear Information System (INIS)

    Ayres, T.R.

    1978-01-01

    Absolute continuum intensities and wavelength-dependent low-order polynomial fits to optical and infrared continuum limb darkening provide useful discriminants among single-component models of the solar photosphere. The thermal structure in best quantitative agreement with the recent center-limb measurements by Pierce and Slaughter (1977) and by Pierce et.al. (1977) is the semi-empirical model by Vernazza, Avrett and Loeser (VAL). However, the VAL model M temperatures must be scaled upward by a factor of 1.015+-0.005 to be consistent with the Labs and Neckel absolute calibration of continuum high points in the optical region 0.40-0.65 μm. (Auth.)

  20. Vertical profiles of aerosol optical properties and the solar heating rate estimated by combining sky radiometer and lidar measurements

    Science.gov (United States)

    Kudo, Rei; Nishizawa, Tomoaki; Aoyagi, Toshinori

    2016-07-01

    The SKYLIDAR algorithm was developed to estimate vertical profiles of aerosol optical properties from sky radiometer (SKYNET) and lidar (AD-Net) measurements. The solar heating rate was also estimated from the SKYLIDAR retrievals. The algorithm consists of two retrieval steps: (1) columnar properties are retrieved from the sky radiometer measurements and the vertically mean depolarization ratio obtained from the lidar measurements and (2) vertical profiles are retrieved from the lidar measurements and the results of the first step. The derived parameters are the vertical profiles of the size distribution, refractive index (real and imaginary parts), extinction coefficient, single-scattering albedo, and asymmetry factor. Sensitivity tests were conducted by applying the SKYLIDAR algorithm to the simulated sky radiometer and lidar data for vertical profiles of three different aerosols, continental average, transported dust, and pollution aerosols. The vertical profiles of the size distribution, extinction coefficient, and asymmetry factor were well estimated in all cases. The vertical profiles of the refractive index and single-scattering albedo of transported dust, but not those of transported pollution aerosol, were well estimated. To demonstrate the performance and validity of the SKYLIDAR algorithm, we applied the SKYLIDAR algorithm to the actual measurements at Tsukuba, Japan. The detailed vertical structures of the aerosol optical properties and solar heating rate of transported dust and smoke were investigated. Examination of the relationship between the solar heating rate and the aerosol optical properties showed that the vertical profile of the asymmetry factor played an important role in creating vertical variation in the solar heating rate. We then compared the columnar optical properties retrieved with the SKYLIDAR algorithm to those produced with the more established scheme SKYRAD.PACK, and the surface solar irradiance calculated from the SKYLIDAR

  1. Laser Ranging in Solar System: Technology Developments and New Science Measurement Capabilities

    Science.gov (United States)

    Sun, X.; Smith, D. E.; Zuber, M. T.; Mcgarry, J.; Neumann, G. A.; Mazarico, E.

    2015-12-01

    Laser Ranging has played a major role in geodetic studies of the Earth over the past 40 years. The technique can potentially be used in between planets and spacecrafts within the solar system to advance planetary science. For example, a direct measurement of distances between planets, such as Mars and Venus would make significant improvements in understanding the dynamics of the whole solar system, including the masses of the planets and moons, asteroids and their perturbing interactions, and the gravity field of the Sun. Compared to the conventional radio frequency (RF) tracking systems, laser ranging is potentially more accurate because it is much less sensitive to the transmission media. It is also more efficient because the laser beams are much better focused onto the targets than RF beams. However, existing laser ranging systems are all Earth centric, that is, from ground stations on Earth to orbiting satellites in near Earth orbits or lunar orbit, and to the lunar retro-reflector arrays deployed by the astronauts in the early days of lunar explorations. Several long distance laser ranging experiments have been conducted with the lidar in space, including a two-way laser ranging demonstration between Earth and the Mercury Laser Altimeter (MLA) on the MESSENGER spacecraft over 24 million km, and a one way laser transmission and detection experiment over 80 million km between Earth and the Mars Orbiting Laser Altimeter (MOLA) on the MGS spacecraft in Mars orbit. A one-way laser ranging operation has been carried out continuously from 2009 to 2014 between multiple ground stations to LRO spacecraft in lunar orbit. The Lunar Laser Communication Demonstration (LLCD) on the LADEE mission has demonstrated that a two way laser ranging measurements, including both the Doppler frequency and the phase shift, can be obtained from the subcarrier or the data clocks of a high speed duplex laser communication system. Plans and concepts presently being studied suggest we may be

  2. Effective aerosol optical depth from pyranometer measurements of surface solar radiation (global radiation at Thessaloniki, Greece

    Directory of Open Access Journals (Sweden)

    A. V. Lindfors

    2013-04-01

    Full Text Available Pyranometer measurements of the solar surface radiation (SSR are available at many locations worldwide, often as long time series covering several decades into the past. These data constitute a potential source of information on the atmospheric aerosol load. Here, we present a method for estimating the aerosol optical depth (AOD using pyranometer measurements of the SSR together with total water vapor column information. The method, which is based on radiative transfer simulations, was developed and tested using recent data from Thessaloniki, Greece. The effective AOD calculated using this method was found to agree well with co-located AERONET measurements, exhibiting a correlation coefficient of 0.9 with 2/3 of the data found within ±20% or ±0.05 of the AERONET AOD. This is similar to the performance of current satellite aerosol methods. Differences in the AOD as compared to AERONET can be explained by variations in the aerosol properties of the atmosphere that are not accounted for in the idealized settings used in the radiative transfer simulations, such as variations in the single scattering albedo and Ångström exponent. Furthermore, the method is sensitive to calibration offsets between the radiative transfer simulations and the pyranometer SSR. The method provides an opportunity of extending our knowledge of the atmospheric aerosol load to locations and times not covered by dedicated aerosol measurements.

  3. Pose Self-Measurement of Noncooperative Spacecraft Based on Solar Panel Triangle Structure

    Directory of Open Access Journals (Sweden)

    Jingzhou Song

    2015-01-01

    Full Text Available Aiming at the recognition and location of noncooperative spacecraft, this paper presents a monocular vision pose measurement method based on solar triangle structure. First of all, an autonomous recognition algorithm of feature structure based on sliding window Hough transformation (SWHT and inscribed circle of a triangle is proposed, and the image coordinates of feature points on the triangle can be obtained relying on this algorithm, combined with the P4P algorithm and the structure of spacecraft, calculating the relative pose of target expressed by rotation and translation matrix. The whole algorithm can be loaded into the prewritten onboard program, which will get the autocomplete feature structure extraction and relative pose measurement without human intervention, and this method does not need to mount any markers on the target. Then compare the measured values with the accurate value of the laser tracker, so that a conclusion can be drawn that the maximum position error is lower than 5% and the rotation error is lower than 4%, which meets the requirements of noncooperative spacecraft’s pose measurement for observations, tracking, and docking in the final rendezvous phase.

  4. In Situ Roughness Measurements for the Solar Cell Industry Using an Atomic Force Microscope

    Directory of Open Access Journals (Sweden)

    Higinio González-Jorge

    2010-04-01

    Full Text Available Areal roughness parameters always need to be under control in the thin film solar cell industry because of their close relationship with the electrical efficiency of the cells. In this work, these parameters are evaluated for measurements carried out in a typical fabrication area for this industry. Measurements are made using a portable atomic force microscope on the CNC diamond cutting machine where an initial sample of transparent conductive oxide is cut into four pieces. The method is validated by making a comparison between the parameters obtained in this process and in the laboratory under optimal conditions. Areal roughness parameters and Fourier Spectral Analysis of the data show good compatibility and open the possibility to use this type of measurement instrument to perform in situ quality control. This procedure gives a sample for evaluation without destroying any of the transparent conductive oxide; in this way 100% of the production can be tested, so improving the measurement time and rate of production.

  5. Determination of Differential Emission Measure Distribution of Coronal Structures Observed by SphinX During Recent Minimum of Solar Activity

    Science.gov (United States)

    Kepa, Anna; Gburek, Szymon; Siarkowski, Marek; Sylwester, Barbara; Sylwester, Janusz; Kowalinski, Miroslaw

    SphinX is a high-sensitivity soft X-ray spectrophotometer which measures soft X-ray spectra in the energy range between 0.8 keV and 15 keV. From February to November 2009 the instrument has observed unusually quiet solar coronal emission as well as a number of weak solar flares. Based on SphinX spectra it is possible to study the differential emission measure distributions (DEM) in the temperature range roughly between 1 MK and 10 MK. The aim of the present study is to unveil DEM plasma distributions for selected activity conditions and analyze their variability.

  6. Dense solar wind cloud geometries deduced from comparisons of radio signal delay and in situ plasma measurements

    Science.gov (United States)

    Landt, J. A.

    1974-01-01

    The geometries of dense solar wind clouds are estimated by comparing single-location measurements of the solar wind plasma with the average of the electron density obtained by radio signal delay measurements along a radio path between earth and interplanetary spacecraft. Several of these geometries agree with the current theoretical spatial models of flare-induced shock waves. A new class of spatially limited structures that contain regions with densities greater than any observed in the broad clouds is identified. The extent of a cloud was found to be approximately inversely proportional to its density.

  7. Spectroscopic classification of transients

    DEFF Research Database (Denmark)

    Stritzinger, M. D.; Fraser, M.; Hummelmose, N. N.

    2017-01-01

    We report the spectroscopic classification of several transients based on observations taken with the Nordic Optical Telescope (NOT) equipped with ALFOSC, over the nights 23-25 August 2017.......We report the spectroscopic classification of several transients based on observations taken with the Nordic Optical Telescope (NOT) equipped with ALFOSC, over the nights 23-25 August 2017....

  8. Comparison of Modelled and Measured Tilted Solar Irradiance for Photovoltaic Applications

    Directory of Open Access Journals (Sweden)

    Riyad Mubarak

    2017-10-01

    Full Text Available This work assesses the performance of five transposition models that estimate the global and diffuse solar irradiance on tilted planes based on the global horizontal irradiance. The modelled tilted irradiance values are compared to measured one-minute values from pyranometers and silicon sensors tilted at different angles at Hannover (Germany and NREL (Golden, CO, USA. It can be recognized that the deviations of the model of Liu and Jordan, Klucher and Perez from the measurements increases as the tilt angle increases and as the sensors are oriented away from the south direction, where they receive lower direct radiation than south-oriented surfaces. Accordingly, the vertical E, W and N planes show the highest deviation. Best results are found by the models from Hay and Davies and Reindl, when horizontal pyranometer measurements and a constant albedo value of 0.2 are used. The relative root mean squared difference (rRMSD of the anisotropic models does not exceed 11% for south orientation and low inclination angles (β = 10–60°, but reaches up to 28.9% at vertical planes. For sunny locations such as Golden, the Perez model provides the best estimates of global tilted irradiance for south-facing surfaces. The relative mean absolute difference (rMAD of the Perez model at NREL ranges from 4.2% for 40° tilt to 8.7% for 90° tilt angle, when horizontal pyranometer measurements and a measured albedo value are used; the use of measured albedo values instead of a constant value of 0.2 leads to a reduction of the deviation to 3.9% and 6.0%, respectively. The use of higher albedo values leads to a significant increase of rMAD. We also investigated the uncertainty resulting from using horizontal pyranometer measurements, in combination with constant albedo values, to estimate the incident irradiance on tilted photovoltaic (PV modules. We found that these uncertainties are small or negligible.

  9. Magnetic field vector and electron density diagnostics from linear polarization measurements in 14 solar prominences

    Science.gov (United States)

    Bommier, V.

    1986-01-01

    The Hanle effect is the modification of the linear polarization parameters of a spectral line due to the effect of the magnetic field. It has been successfully applied to the magnetic field vector diagnostic in solar prominences. The magnetic field vector is determined by comparing the measured polarization to the polarization computed, taking into account all the polarizing and depolarizing processes in line formation and the depolarizing effect of the magnetic field. The method was applied to simultaneous polarization measurements in the Helium D3 line and in the hydrogen beta line in 14 prominences. Four polarization parameters are measured, which lead to the determination of the three coordinates of the magnetic field vector and the electron density, owing to the sensitivity of the hydrogen beta line to the non-negligible effect of depolarizing collisions with electrons and protons of the medium. A mean value of 1.3 x 10 to the 10th power cu. cm. is derived in 14 prominences.

  10. Geometric optimisation of an accurate cosine correcting optic fibre coupler for solar spectral measurement

    Science.gov (United States)

    Cahuantzi, Roberto; Buckley, Alastair

    2017-09-01

    Making accurate and reliable measurements of solar irradiance is important for understanding performance in the photovoltaic energy sector. In this paper, we present design details and performance of a number of fibre optic couplers for use in irradiance measurement systems employing remote light sensors applicable for either spectrally resolved or broadband measurement. The angular and spectral characteristics of different coupler designs are characterised and compared with existing state-of-the-art commercial technology. The new coupler designs are fabricated from polytetrafluorethylene (PTFE) rods and operate through forward scattering of incident sunlight on the front surfaces of the structure into an optic fibre located in a cavity to the rear of the structure. The PTFE couplers exhibit up to 4.8% variation in scattered transmission intensity between 425 nm and 700 nm and show minimal specular reflection, making the designs accurate and reliable over the visible region. Through careful geometric optimization near perfect cosine dependence on the angular response of the coupler can be achieved. The PTFE designs represent a significant improvement over the state of the art with less than 0.01% error compared with ideal cosine response for angles of incidence up to 50°.

  11. Solar Modulation of Atmospheric Cosmic Radiation:. Comparison Between In-Flight and Ground-Level Measurements

    Science.gov (United States)

    Iles, R. H. A.; Taylor, G. C.; Jones, J. B. L.

    January 2000 saw the start of a collaborative study involving the Mullard Space Science Laboratory, Virgin Atlantic Airways, the Civil Aviation Authority and the National Physical Laboratory in a program to investigate the cosmic radiation exposure to aircrew. The study has been undertaken in view of EU Directive 96/291 (May 2000) which requires the assessment of the level of radiation exposure to aircrew. The project's aims include validation of radiation dose models and evaluation of space weather effects on atmospheric cosmic radiation levels, in particular those effects not accounted for by the models. Ground level measurements are often used as a proxy for variations in cosmic radiation dose levels at aircraft altitudes, especially during Forbush Decreases (FDs) and Solar Energetic Particle (SEP) events. Is this estimation realistic and does the ground level data accurately represent what is happening at altitude? We have investigated the effect of a FD during a flight from Hong Kong to London Heathrow on the 15th July 2000 and compared count rate and dose measurements with simultaneous variations measured at ground level. We have also compared the results with model outputs.

  12. Geometric optimisation of an accurate cosine correcting optic fibre coupler for solar spectral measurement.

    Science.gov (United States)

    Cahuantzi, Roberto; Buckley, Alastair

    2017-09-01

    Making accurate and reliable measurements of solar irradiance is important for understanding performance in the photovoltaic energy sector. In this paper, we present design details and performance of a number of fibre optic couplers for use in irradiance measurement systems employing remote light sensors applicable for either spectrally resolved or broadband measurement. The angular and spectral characteristics of different coupler designs are characterised and compared with existing state-of-the-art commercial technology. The new coupler designs are fabricated from polytetrafluorethylene (PTFE) rods and operate through forward scattering of incident sunlight on the front surfaces of the structure into an optic fibre located in a cavity to the rear of the structure. The PTFE couplers exhibit up to 4.8% variation in scattered transmission intensity between 425 nm and 700 nm and show minimal specular reflection, making the designs accurate and reliable over the visible region. Through careful geometric optimization near perfect cosine dependence on the angular response of the coupler can be achieved. The PTFE designs represent a significant improvement over the state of the art with less than 0.01% error compared with ideal cosine response for angles of incidence up to 50°.

  13. Structure and reactivity of lithium amides. /sup 6/Li, /sup 13/C, and /sup 15/N NMR spectroscopic studies and colligative measurements of lithium diphenylamide and lithium diphenylamide-lithium bromide complex solvated by tetrahydrofuran

    Energy Technology Data Exchange (ETDEWEB)

    DePue, J.S.; Collum, D.B.

    1988-08-03

    /sup 6/Li, /sup 13/C, and /sup 15/N NMR spectroscopic studies of lithium diphenylamide in THF/hydrocarbon solutions (THF = tetrahydrofuran) detected two different species. /sup 6/Li and /sup 15/N NMR spectroscopic studies of (/sup 6/Li, /sup 15/N)lithium diphenylamide showed the species observed at low THF concentrations to be a cyclic oligomer. Structural analogies provided strong support for a dimer while colligative measurements at 0/degrees/C indicated the dimer to be di- or trisolvated. On the basis of the observed mass action effects, the species appearing at intermediate THF concentrations is assigned as a contact or solvent-separated ion-paired monomer. Lithium diphenylamide forms a 1:1 adduct with lithium bromide at low THF concentrations. A combination of /sup 6/Li-/sup 15/N double labeling studies and colligative measurements supports a trisolvated cyclic mixed dimer structure. Although detailed spectroscopic studies at elevated THF concentrations were precluded by high fluctionality, the similarity of the /sup 13/C chemical shifts of lithium diphenylamide in the presence and absence of lithium bromide provide indirect evidence that the mixed dimer undergoes a THF concentration dependent dissociation to the monomeric amide and free lithium bromide. 24 references, 9 figures, 2 tables.

  14. FTIR-spectroscopic measurements of beryls of various sources and the geological mineralogical and gemmological characterization of diamonds of the Espinhago-range (Minas Gerais, Brazil)

    International Nuclear Information System (INIS)

    Banko, A. G.

    1997-09-01

    In this work international material of beryl was analyzed by FTIR-spectroscopy, electron microprobe, analytical scanning microscopy, moisture evolution analyzer and fluorine sensitive electrode. The FTIR-spectroscopic measurements and the determination of analytical water content reveal a logarithmic correlation between the beryl water content and the intensity of the H 2 O-combination band at 5275 cm -1 , using unpolarized IR-light. In addition, the intensities of the 3990 - 3970 cm -1 ,-, 3234 cm -1 and 3345 cm -1 -bands, measured with polarized IR-light parallel to the c-axis, are linearly correlated to the content of the alkali metals. Probably these bands correspond to fundamental (1st overtone of H 2 O-II/3234 cm -1 - and 3345 cm -1 ) and combination (alkaliO-H...OH 2 -II/ 3990 - 3970 cm -1 ) modes of bending vibrations. Beryl was deuterated at various temperature. No absorption were detected in the region at around 2390 cm -1 , 2470 cm -1 and 2940 cm -1 , which would prove an assignment related to the present of hydrogen. If alkali-hydroxide grouping in beryl-channel-positions is indeuterable, the model of fundamental and combination modes seems to be valid. The band at 3990 - 3970 cm -1 can also be assigned to the combination mode of alkali-oxygen (alkali (6),(12) -O-bonds) vibrations and the normal modes of the H 2 O- II -molecule. The three integral absorption coefficients - α 5267 (H 2 O-II)t α 5275 (H 2 O-I) and α 2358 (CO 2 ) - were used to subdivide the beryls into groups. The Espinhago-Diamond-Province reflects an interesting geologic history from Precambrian placer- to recent alluvial deposits. Mineralogical and gemmological features, in combination with geological aspects reflect the many reworking processes which affected Espinhago diamonds in time and space: the characteristics of diamond populations in their specific geologic environment represent the natural selection, which eliminated stones of low quality during geologic history. (author)

  15. Relation of field-aligned currents measured by AMPERE project to solar wind and substorms

    Science.gov (United States)

    McPherron, R. L.; Anderson, B. J.; Chu, X.

    2016-12-01

    Magnetic perturbations measured in the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) by the Iridium constellation of spacecraft have been processed to obtain the time history of field-aligned currents (FAC) connecting the magnetosphere to the ionosphere. We find that the strength of these currents is closely related to the strength of the solar wind driver defined as a running average of the previous three hours of the optimum AL (auroral lower) coupling function. The relation is well represented by a saturation model I = A*S*Ss/(S+Ss) with I the current strength in mega Amps, S the driver strength in mV/m, Ss the saturation value of 7.78 mV/m, and A = 2.55 scales the relation to units of current. We also find that in general the upward current on the nightside increases with each substorm expansion onset defined by a combination of the SuperMag SML (SuperMag AL) and midlatitude positive bay (MPB) onset lists. A superposed epoch analysis using 700 onsets in 2010 shows the following: solar wind coupling peaks at expansion onset; dayside outward current starts to increase one hour before onset while nightside outward current starts suddenly at onset; nightside outward current reaches a peak at 28 minutes as do SML and MPB indices; FAC, SML, and MPB respectively take 1, 2, and 3 hours to decay to background. The data indicate that the substorm current wedge is superposed on a pre-existing field-aligned current system and that the location and properties of the current wedge can be studied with the AMPERE data.

  16. Estimation of the hydrogen flux from a PEM electrolyzer, based in the solar irradiation measured in Zacatecas Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Duron-Torres, S.M.; Villagrana-Munoz, L.E.; Garcia-Saldivar, V.M.; Escalante-Garcia, I.L. [Univ. Autonoma de Zacatecas, Zacatecas (Mexico). Unidad Academica de Ciencias Quimicas; Arriaga-Hurtado, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Pedro Escobedo (Mexico)

    2010-07-15

    The current cost of obtaining hydrogen from electrolyzers is higher than the cost of producing fossil fuels. However, with advances in technology and greater use of alternative energy sources, the cost of electrolytic hydrogen production may decrease to the point of being competitive. This study calculated how much hydrogen can be produced in a typical polymer exchange membrane (PEM) electrolyzer. Local solar irradiation measurements were carried out from November 2007 to April 2008 at the Campus Siglo 21 Solarimetric Station at Zacatecas University in Mexico. The mean irradiation measured was 6.6 kW-h per m{sup 2}. Based on the solar data obtained at the station, the hydrogen produced by a typical solar-hydrogen (SH) system was evaluated. The study showed that an important quantity of hydrogen as an energy vector could be obtained from solar radiation. April was determined to be the month of maximum hydrogen production. The lowest hydrogen production was in November. The data obtained during this study can be used to evaluate the solar renewable energy resource expressed as hydrogen production. 19 refs., 1 tab., 4 figs.

  17. Test bench HEATREC for heat loss measurement on solar receiver tubes

    Science.gov (United States)

    Márquez, José M.; López-Martín, Rafael; Valenzuela, Loreto; Zarza, Eduardo

    2016-05-01

    In Solar Thermal Electricity (STE) plants the thermal energy of solar radiation is absorbed by solar receiver tubes (HCEs) and it is transferred to a heat transfer fluid. Therefore, heat losses of receiver tubes have a direct influence on STE plants efficiency. A new test bench called HEATREC has been developed by Plataforma Solar de Almería (PSA) in order to determinate the heat losses of receiver tubes under laboratory conditions. The innovation of this test bench consists in the possibility to determine heat losses under controlled vacuum.

  18. Applying spaceborne reflectivity measurements for calculation of the solar ultraviolet radiation at ground level

    Directory of Open Access Journals (Sweden)

    P. N. den Outer

    2012-12-01

    Full Text Available Long-term analysis of cloud effects on ultraviolet (UV radiation on the ground using spaceborne observations requires the use of instruments that have operated consecutively. The longest data record can be built from the reflectivity measurements produced by the instruments Total Ozone Mapping Spectrometers (TOMS flown on Nimbus 7 from 1979 to 1992, TOMS on Earth Probe from 1996 to 2005, and the Ozone Monitoring Instrument (OMI flown on EOS Aura since 2004. The reflectivity data produced by TOMS on Earth Probe is only included until 2002. A comparison is made with cloud effects inferred from ground-based pyranometer measurements at over 83 World Radiation Data Centre stations. Modelled UV irradiances utilizing the standard reflectivity are compared with measurements of UV irradiances at eight European low-elevation stations. The reflectivity data of the two TOMS instruments shows a consistent agreement, and the required corrections are of low percentage, i.e. 2–3%. In contrast, the reflectivity product of OMI requires correction of 7–10%, and a solar angle dependency therein is more pronounced. These corrections were inferred from a comparison with pyranometer data, and tested using the UV measurements. The average reduction of UV radiation due to clouds for all sites together indicates a small trend: a diminishing cloudiness, in line with ground-based UV observations. Uncorrected implementation of the reflectivity data would have indicated the opposite.

    An optimal area was established for reflectivity data for the calculation of daily sums of UV radiation. It measures approximately 1.25° in latitudinal direction for square-shaped areas overhead the ground-based UV stations. Such an area can be traversed within 5 to 7 h at the average wind speeds found for the West European continent.

  19. Think the way to measure the Earth R