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Sample records for polarization caliop instrument

  1. An assessment of CALIOP polar stratospheric cloud composition classification

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    M. C. Pitts

    2013-03-01

    Full Text Available This study assesses the robustness of the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization polar stratospheric cloud (PSC composition classification algorithm – which is based solely on the spaceborne lidar data – through the use of nearly coincident gas-phase HNO3 and H2O data from the Microwave Limb Sounder (MLS on Aura and Goddard Earth Observing System Model, Version 5 (GEOS-5 temperature analyses. Following the approach of Lambert et al. (2012, we compared the observed temperature-dependent HNO3 uptake by PSCs in the various CALIOP composition classes with modeled uptake for supercooled ternary solutions (STS and equilibrium nitric acid trihydrate (NAT. We examined the CALIOP PSC data record from both polar regions over the period from 2006 through 2011 and over a range of potential temperature levels spanning the 15–30 km altitude range. We found that most PSCs identified as STS exhibit gas phase uptake of HNO3 consistent with theory, but with a small temperature bias, similar to Lambert et al. (2012. Ice PSC classification is also robust in the CALIOP optical data, with the mode in the ice observations occurring about 0.5 K below the frost point. We found that CALIOP PSCs identified as NAT mixtures exhibit two distinct preferred modes which reflect the fact that the growth of NAT particles is kinetically limited. One mode is significantly out of thermodynamic equilibrium with respect to NAT due to short exposure times to temperatures below the NAT existence temperature, TNAT, with HNO3 uptake dominated by the more numerous liquid droplets. The other NAT mixture mode is much closer to NAT thermodynamic equilibrium, indicating that the particles have been exposed to temperatures below TNAT for extended periods of time. With a few notable exceptions, PSCs in the various composition classes conform well to their expected temperature existence regimes. We have a good understanding of the cause of the minor misclassifications that

  2. Subtropical and Polar Cirrus Clouds Characterized by Ground-Based Lidars and CALIPSO/CALIOP Observations

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    Córdoba-Jabonero Carmen

    2016-01-01

    Full Text Available Cirrus clouds are product of weather processes, and then their occurrence and macrophysical/optical properties can vary significantly over different regions of the world. Lidars can provide height-resolved measurements with a relatively good both vertical and temporal resolutions, making them the most suitable instrumentation for high-cloud observations. The aim of this work is to show the potential of lidar observations on Cirrus clouds detection in combination with a recently proposed methodology to retrieve the Cirrus clouds macrophysical and optical features. In this sense, a few case studies of cirrus clouds observed at both subtropical and polar latitudes are examined and compared to CALIPSO/CALIOP observations. Lidar measurements are carried out in two stations: the Metropolitan city of Sao Paulo (MSP, Brazil, 23.3°S 46.4°W, located at subtropical latitudes, and the Belgrano II base (BEL, Argentina, 78ºS 35ºW in the Antarctic continent. Optical (COD-cloud optical depth and LR-Lidar Ratio and macrophysical (top/base heights and thickness properties of both the subtropical and polar cirrus clouds are reported. In general, subtropical Cirrus clouds present lower LR values and are found at higher altitudes than those detected at polar latitudes. In general, Cirrus clouds are detected at similar altitudes by CALIOP. However, a poor agreement is achieved in the LR retrieved between ground-based lidars and space-borne CALIOP measurements, likely due to the use of a fixed (or low-variable LR value in CALIOP inversion procedures.

  3. Interannual variations of early winter Antarctic polar stratospheric cloud formation and nitric acid observed by CALIOP and MLS

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    Lambert, Alyn; Santee, Michelle L.; Livesey, Nathaniel J.

    2016-12-01

    We use satellite-borne measurements collected over the last decade (2006-2015) from the Aura Microwave Limb Sounder (MLS) and the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) to investigate the nitric acid distribution and the properties of polar stratospheric clouds (PSCs) in the early winter Antarctic vortex. Frequently, at the very start of the winter, we find that synoptic-scale depletion of HNO3 can be detected in the inner vortex before the first lidar detection of geophysically associated PSCs. The generation of "sub-visible" PSCs can be explained as arising from the development of a solid particle population with low number densities and large particle sizes. Assumed to be composed of nitric acid trihydrate (NAT), the sub-visible PSCs form at ambient temperatures well above the ice frost point, but also above the temperature at which supercooled ternary solution (STS) grows out of the background supercooled binary solution (SBS) distribution. The temperature regime of their formation, inferred from the simultaneous uptake of ambient HNO3 into NAT and their Lagrangian temperature histories, is at a depression of a few kelvin with respect to the NAT existence threshold, TNAT. Therefore, their nucleation requires a considerable supersaturation of HNO3 over NAT, and is consistent with a recently described heterogeneous nucleation process on solid foreign nuclei immersed in liquid aerosol. We make a detailed investigation of the comparative limits of detection of PSCs and the resulting sequestration of HNO3 imposed by lidar, mid-infrared, and microwave techniques. We find that the temperature history of air parcels, in addition to the local ambient temperature, is an important factor in the relative frequency of formation of liquid/solid PSCs. We conclude that the initiation of NAT nucleation and the subsequent development of large NAT particles capable of sedimentation and denitrification in the early winter do not emanate from an ice

  4. A-train CALIOP and MLS observations of early winter Antarctic polar stratospheric clouds and nitric acid in 2008

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    A. Lambert

    2012-03-01

    Full Text Available A-train Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP and Microwave Limb Sounder (MLS observations are used to investigate the development of polar stratospheric clouds (PSCs and the gas-phase nitric acid distribution in the early 2008 Antarctic winter. Observational evidence of gravity-wave activity is provided by Atmospheric Infrared Sounder (AIRS radiances and infrared spectroscopic detection of nitric acid trihydrate (NAT in PSCs is obtained from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS. Goddard Earth Observing System Data Assimilation System (GEOS-5 DAS analyses are used to derive Lagrangian trajectories and to determine temperature-time histories of air parcels. We use CALIOP backscatter and depolarization measurements to classify PSCs and the MLS measurements to determine the corresponding gas-phase HNO3 as a function of temperature. For liquid PSCs the uptake of HNO3 follows the theoretical equilibrium curve for supercooled ternary solutions (STS, but at temperatures about 1 K lower as determined from GEOS-5. In the presence of solid phase PSCs, above the ice frost-point, the HNO3 depletion occurs over a wider range of temperatures (+2 to −7 K distributed about the NAT equilibrium curve. Rapid gas-phase HNO3 depletion is first seen by MLS from from 23–25 May 2008, consisting of a decrease in the volume mixing ratio from 14 ppbv (parts per billion by volume to 7 ppbv on the 46–32 hPa (hectopascal pressure levels and accompanied by a 2–3 ppbv increase by renitrification at the 68 hPa pressure level. The observed region of depleted HNO3 is substantially smaller than the region bounded by the NAT existence temperature threshold. Temperature-time histories of air parcels demonstrate that the depletion is more clearly correlated with prior exposure to temperatures a few kelvin above the frost-point. From the combined data we infer the presence

  5. Depolarization ratio of polar stratospheric clouds in coastal Antarctica: comparison analysis between ground-based Micro Pulse Lidar and space-borne CALIOP observations

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    C. Córdoba-Jabonero

    2013-03-01

    Full Text Available Polar stratospheric clouds (PSCs play an important role in polar ozone depletion, since they are involved in diverse ozone destruction processes (chlorine activation, denitrification. The degree of that ozone reduction is depending on the type of PSCs, and hence on their occurrence. Therefore PSC characterization, mainly focused on PSC-type discrimination, is widely demanded. The backscattering (R and volume linear depolarization (δV ratios are the parameters usually used in lidar measurements for PSC detection and identification. In this work, an improved version of the standard NASA/Micro Pulse Lidar (MPL-4, which includes a built-in depolarization detection module, has been used for PSC observations above the coastal Antarctic Belgrano II station (Argentina, 77.9° S 34.6° W, 256 m a.s.l. since 2009. Examination of the MPL-4 δV feature as a suitable index for PSC-type discrimination is based on the analysis of the two-channel data, i.e., the parallel (p- and perpendicular (s- polarized MPL signals. This study focuses on the comparison of coincident δV-profiles as obtained from ground-based MPL-4 measurements during three Antarctic winters with those reported from the space-borne lidar CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization aboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation satellite in the same period (83 simultaneous cases are analysed for 2009–2011 austral winter times. Three different approaches are considered for the comparison analysis between both lidar profile data sets in order to test the degree of agreement: the correlation coefficient (CC, as a measure of the relationship between both PSC vertical structures; the mean differences together with their root mean square (RMS values found between data sets; and the percentage differences (BIAS, parameter also used in profiling comparisons between CALIOP and other ground-based lidar systems. All of them are examined as a function

  6. CALIOP-derived Smoke Plume Injection Height

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    Soja, A. J.; Winker, D. M.; Choi, H. D.; Fairlie, T. D.; Westberg, D. J.; Roller, C. M.; Pouliot, G.; Vaughan, M.; Pierce, T. E.; Trepte, C. R.; Rao, V.

    2014-12-01

    Biomass burning is a dominant natural and anthropogenic disturbance that feeds back to the climate system. Fire regimes, ecosystem fuels, fire severity and intensity vary widely, even within the same system, largely under the control of weather and climate. These strongly influence fire plume injection height and thus the transport of related biomass burning emissions, affecting air quality, human health and the climate system. If our knowledge of plume injection height is incorrect, transport models of those emissions will likewise be incorrect, adversely affecting our ability to analyze and predict climate feedbacks (i.e. black carbon to the Arctic, precipitation, cloud-radiation relationships) and public health (air quality forecast). Historically, plume height was based on the pioneering work of G.A. Briggs [1969; 1971] and verified with limited field campaigns. However, we currently have two satellite instruments, Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) onboard CALIPSO (afternoon overpass) and Multi-angle Imaging SpectroRadiometer (MISR) onboard TERRA (morning overpass), that can provide the statistics necessary to verify our assumptions and improve fire plume injection height estimates for use in both small- and large-scale models. We have developed a methodology to assess fire plume injection height using the Langley Trajectory Model (LaTM), CALIOP, Hazard Mapping System (HMS) smoke plume, and MODerate Resolution Imaging Spectrometer (MODIS) thermal anomaly data that is capable of generating two distinct types of verification data. A single CALIOP smoke-filled aerosol envelop can be traced back to numerous fire events, and using multiple CALIOP transects from numerous days, a daily smoke plume injection height evolution from a single fire can be defined. Additionally, we have linked the smoke plumes to ecosystems and the meteorological variables that define fire weather. In concert, CALIOP and MISR data can produce the statistical knowledge

  7. HAWC+/SOFIA Instrumental Polarization Calibration

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    Michail, Joseph M.; Chuss, David; Dowell, Charles D.; Santos, Fabio; Siah, Javad; Vaillancourt, John; HAWC+ Instrument Team

    2018-01-01

    HAWC+ is a new far-infrared polarimeter for the NASA/DLR SOFIA (Stratospheric Observatory for Infrared Astronomy) telescope. HAWC+ has the capability to measure the polarization of astronomical sources with unprecedented sensitivity and angular resolution in four bands from 50-250 microns. Using data obtained during commissioning flights, we implemented a calibration strategy that separates the astronomical polarization signal from the induced instrumental polarization. The result of this analysis is a map of the instrumental polarization as a function of position in the instrument's focal plane in each band. The results show consistency between bands, as well as with other methods used to determine preliminary instrumental polarization values.

  8. Global Measurements of Optically Thin Ice Clouds Using CALIOP

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    Ryan, R.; Avery, M.; Tackett, J.

    2017-01-01

    Optically thin ice clouds have been shown to have a net warming effect on the globe but, because passive instruments are not sensitive to optically thin clouds, the occurrence frequency of this class of clouds is greatly underestimated in historical passive sensor cloud climatology. One major strength of CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization), onboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) spacecraft, is its ability to detect these thin clouds, thus filling an important missing piece in the historical data record. This poster examines the full mission of CALIPSO Level 2 data, focusing on those CALIOP retrievals identified as thin ice clouds according to the definition shown to the right. Using this definition, thin ice clouds are identified and counted globally and vertically for each season. By examining the spatial and seasonal distributions of these thin clouds we hope to gain a better understanding these thin ice clouds and how their global distribution has changed over the mission. This poster showcases when and where CALIOP detects thin ice clouds and examines a case study of the eastern pacific and the effects seen from the El Nino-Southern Oscillation (ENSO).

  9. Efficient polarization analysis for focusing neutron instruments

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    Stahn, Jochen; Glavic, Artur

    2017-06-01

    Polarized neutrons are a powerful probe to investigate magnetism in condensed matter on length scales from single atomic distances to micrometers. With the ongoing advancement of neutron optics, that allow to transport beams with increased divergence, the demands on neutron polarizes and analyzers have grown as well. The situation becomes especially challenging for new instruments at pulsed sources, where a large wavelength band needs to be polarized to make efficient use of the time structure of the beam. Here we present a polarization analysis concept for highly focused neutron beams that is based on transmission supermirrors that are bend in the shape of equiangular spirals. The method allows polarizations above 95% and good transmission, without negative impact on other beam characteristics. An example of a compact polarizing device already tested on the AMOR reflectometer is presented as well as the concept for the next generation implementation of the technique that will be installed on the Estia instrument being build for the European Spallation Source.

  10. Calibration of the instrumental polarization in LEST.

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    Stenflo, J. O.

    A method to calibrate the instrumental polarization of LEST (i.e., of the optics in front of the polarization and analysis package at the LEST secondary focus) is described and analysed. A laser sends a beam from the LEST observing room at ground level backwards through the telescope. The modulated return beam that has been reflected at the 2.4 m entrance window is received by the detector system at the end focus in the LEST observing room. Because of a wedge in the entrance window the reflections at the front and back window surfaces may be examined separately. The detected laser beam signals at the three AC frequencies are recorded as functions of the position angle of the modulator package at the LEST secondary focus. Aided by a theorem that is proven in the present paper, the information recorded by the detector system allows all unknowns of the instrumental polarization to be fully determined.

  11. Accuracy and precision of polar lower stratospheric temperatures from reanalyses evaluated from A-Train CALIOP and MLS, COSMIC GPS RO, and the equilibrium thermodynamics of supercooled ternary solutions and ice clouds

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    Lambert, Alyn; Santee, Michelle L.

    2018-02-01

    We investigate the accuracy and precision of polar lower stratospheric temperatures (100-10 hPa during 2008-2013) reported in several contemporary reanalysis datasets comprising two versions of the Modern-Era Retrospective analysis for Research and Applications (MERRA and MERRA-2), the Japanese 55-year Reanalysis (JRA-55), the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-I), and the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (NCEP-CFSR). We also include the Goddard Earth Observing System model version 5.9.1 near-real-time analysis (GEOS-5.9.1). Comparisons of these datasets are made with respect to retrieved temperatures from the Aura Microwave Limb Sounder (MLS), Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) Global Positioning System (GPS) radio occultation (RO) temperatures, and independent absolute temperature references defined by the equilibrium thermodynamics of supercooled ternary solutions (STSs) and ice clouds. Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations of polar stratospheric clouds are used to determine the cloud particle types within the Aura MLS geometric field of view. The thermodynamic calculations for STS and the ice frost point use the colocated MLS gas-phase measurements of HNO3 and H2O. The estimated bias and precision for the STS temperature reference, over the 68 to 21 hPa pressure range, are 0.6-1.5 and 0.3-0.6 K, respectively; for the ice temperature reference, they are 0.4 and 0.3 K, respectively. These uncertainties are smaller than those estimated for the retrieved MLS temperatures and also comparable to GPS RO uncertainties (bias 0.7 K) in the same pressure range. We examine a case study of the time-varying temperature structure associated with layered ice clouds formed by orographic gravity waves forced by flow over the Palmer Peninsula and

  12. The on-orbit performance of the CALIOP LIDAR on CALIPSO

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    Winker, David; Hunt, William; Weimer, Carl

    2017-11-01

    CALIPSO is a joint NASA - CNES satellite currently in its third year of operation in low earth orbit. The satellite is making optical measurements of the Earth's atmosphere to help quantify the impact of aerosols and clouds on the Earth's radiation budget. To do this, it carries three instruments: CALIOP, a two-wavelength polarization-sensitive elastic backscatter lidar; the IIR a three band thermal imaging radiometer; and the WFC a visible single-band imager. CALIOP utilizes a Nd:YAG laser which incorporates a harmonic crystal to provide laser light at both 1064 nm and 532 nm. This beam is expanded and transmitted into the atmosphere at near nadir. The laser light scattered from clouds and aerosols back to the satellite, along with any solar background light, is collected by a one meter diameter beryllium telescope. The captured light is separated into its two wavelengths and optically filtered. The 1064 nm component is detected with an avalanche photodiode, while the 532 nm component is further resolved into two linear polarization components which are then detected by matching photomultiplier tubes. This presentation will describe the lidar and give examples of its on-orbit performance.

  13. The Primordial Inflation Polarization Explorer (PIPER): Instrument Description.

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    Eimer, Joseph; Bennett, C.; McCullagh, N.; Zeng, L.; Benford, D.; Chuss, D.; Fixsen, D.; Hinderks, J.; Jhabvala, C.; Kogut, A.; Mirel, P.; Moseley, S.; Staguhn, J.; Voellmer, G.; Wollack, E.; Irwin, K.; Hilton, G.; Halpern, M.; Ade, P.; Tucker, C.; Dotson, J.

    2010-01-01

    We describe the PIPER balloon born instrument for observing the polarization of the cosmic microwave background. The experiment uses two co-aligned cold optic telescopes with variable-delay polarization modulators as their first optical element. Each telescope has two 32 x 40 arrays of backshort-under-grid(BUG) TES bolometers.

  14. Coherence approach to neutron polarization propagation in instruments

    NARCIS (Netherlands)

    De Haan, V.O.; Van Well, A.A.; Plomp, J.

    2008-01-01

    The propagation of the mutual coherence function is a well known method to describe the effects of neutron’s propagation through scattering instruments. This method is extended with the description of the coherence matrix to account for neutron polarization effects and its propagation through an

  15. Space optical instrumentation for earth observation - The polar platform era

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    Peraldi, Armand

    1988-01-01

    Consideration is given to two instruments for earth observation from large polar platforms: a Thermal IR Imager (TIRI) and a High Resolution Imaging Spectrometer (HRIS). TIRI is an optical push-broom imager designed for operation in the 8-12 micron band, split into two spectral bands. Because each line of an image is electronically scanned by linear arrays of detectors, TIRI does not require a mechanical scanning device. HRIS is designed to provide very high resolution images from 260 spectral channels. Any set of 30 individual channels may be transmitted to the ground. These two instruments are described and illustrated and the possible applications of the instruments on a polar platform are discussed.

  16. Development of an embedded instrument for autofocus and polarization alignment of polarization maintaining fiber

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    Feng, Di; Fang, Qimeng; Huang, Huaibo; Zhao, Zhengqi; Song, Ningfang

    2017-12-01

    The development and implementation of a practical instrument based on an embedded technique for autofocus and polarization alignment of polarization maintaining fiber is presented. For focusing efficiency and stability, an image-based focusing algorithm fully considering the image definition evaluation and the focusing search strategy was used to accomplish autofocus. For improving the alignment accuracy, various image-based algorithms of alignment detection were developed with high calculation speed and strong robustness. The instrument can be operated as a standalone device with real-time processing and convenience operations. The hardware construction, software interface, and image-based algorithms of main modules are described. Additionally, several image simulation experiments were also carried out to analyze the accuracy of the above alignment detection algorithms. Both the simulation results and experiment results indicate that the instrument can achieve the accuracy of polarization alignment <±0.1 deg.

  17. A method of detecting sea fogs using CALIOP data and its application to improve MODIS-based sea fog detection

    International Nuclear Information System (INIS)

    Wu, Dong; Lu, Bo; Zhang, Tianche; Yan, Fengqi

    2015-01-01

    A method to detect sea fogs from the measurement data acquired by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite is proposed in this paper. Because of the unique capability of vertical-resolved measurements, sea fogs and low clouds can be more easily distinguished in the CALIOP data compared with passive satellite measurements. Yellow Sea where sea fogs occur frequently is selected to test the method. Nine cases of daytime sea fog events from 2008 to 2011 in the Yellow Sea are studied intensively to characterize the remotely sensed radiation properties of various targets, such as clear-sky sea surface, sea fog, low cloud and high cloud. These fog cases are then used in an attempt to evaluate sea fogs identified from the MODIS measurements. The method proposed in this paper can also be used for nighttime cases. Multi-year sea fog dataset can be made from the CALIOP measurement and used to validate the MODIS sea fog detection. - Highlights: • A method of sea fog detection from the CALIOP measurements is proposed. • CALIOP VFM and 532-nm attenuated backscatter products are integrated used. • Sea fogs and low clouds can be more easily distinguished in the CALIOP data. • 9 Cases of daytime sea fog events in the Yellow Sea are selected to test the method. • The MODIS sea fog detections are evaluated using the collocated CALIOP data

  18. Enhancements to the CALIOP Aerosol Subtyping and Lidar Ratio Selection Algorithms for Level II Version 4

    Science.gov (United States)

    Omar, A. H.; Tackett, J. L.; Vaughan, M. A.; Kar, J.; Trepte, C. R.; Winker, D. M.

    2016-12-01

    This presentation describes several enhancements planned for the version 4 aerosol subtyping and lidar ratio selection algorithms of the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument. The CALIOP subtyping algorithm determines the most likely aerosol type from CALIOP measurements (attenuated backscatter, estimated particulate depolarization ratios δe, layer altitude), and surface type. The aerosol type, so determined, is associated with a lidar ratio (LR) from a discrete set of values. Some of these lidar ratios have been updated in the version 4 algorithms. In particular, the dust and polluted dust will be adjusted to reflect the latest measurements and model studies of these types. Version 4 eliminates the confusion between smoke and clean marine aerosols seen in version 3 by modifications to the elevated layer flag definitions used to identify smoke aerosols over the ocean. In the subtyping algorithms pure dust is determined by high estimated particulate depolarization ratios [δe > 0.20]. Mixtures of dust and other aerosol types are determined by intermediate values of the estimated depolarization ratio [0.075limited to mixtures of dust and smoke, the so called polluted dust aerosol type. To differentiate between mixtures of dust and smoke, and dust and marine aerosols, a new aerosol type will be added in the version 4 data products. In the revised classification algorithms, polluted dust will still defined as dust + smoke/pollution but in the marine boundary layer instances of moderate depolarization will be typed as dusty marine aerosols with a lower lidar ratio than polluted dust. The dusty marine type introduced in version 4 is modeled as a mixture of dust + marine aerosol. To account for fringes, the version 4 Level 2 algorithms implement Subtype Coalescence Algorithm for AeRosol Fringes (SCAARF) routine to detect and classify fringe of aerosol plumes that are detected at 20 km or 80 km horizontal resolution at the plume base. These

  19. The comparison of MODIS-Aqua (C5 and CALIOP (V2 & V3 aerosol optical depth

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    J. Redemann

    2012-03-01

    Full Text Available We assess the consistency between instantaneously collocated level-2 aerosol optical depth (AOD retrievals from MODIS-Aqua (C5 and CALIOP (Version 2 & 3, comparing the standard MODIS AOD (MYD04_L2 data to the AOD calculated from CALIOP aerosol extinction profiles for both the previous release (V2 and the latest release (V3 of CALIOP data. Based on data collected in January 2007, we investigate the most useful criteria for screening the MODIS and CALIOP retrievals to achieve the best agreement between the two data sets. Applying these criteria to eight months of data (Jan, Apr, Jul, Oct 2007 and 2009, we find an order of magnitude increase for the CALIOP V3 data density (by comparison to V2, that is generally accompanied by equal or better agreement with MODIS AOD. Differences in global, monthly mean, over-ocean AOD (532 nm between CALIOP and MODIS range between 0.03 and 0.04 for CALIOP V3, with CALIOP generally biased low, when all available data from both sensors are considered. Root-mean-squares (RMS differences in instantaneously collocated AOD retrievals by the two instruments are reduced from values ranging between 0.14 and 0.19 using the unscreened V3 data to values ranging from 0.09 to 0.1 for the screened data. A restriction to scenes with cloud fractions less than 1% (as defined in the MODIS aerosol retrievals generally results in improved correlation (R2>0.5, except for the month of July when correlations remain relatively lower. Regional assessments show hot spots in disagreement between the two sensors in Asian outflow during April and off the coast of South Africa in July.

  20. Polarization Characteristics Inferred From the Radio Receiver Instrument on the Enhanced Polar Outflow Probe

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    Danskin, Donald W.; Hussey, Glenn C.; Gillies, Robert G.; James, H. Gordon; Fairbairn, David T.; Yau, Andrew W.

    2018-02-01

    The Radio Receiver Instrument (RRI) on the CAScade, Smallsat, and Ionospheric Polar Explorer/enhanced Polar Outflow Probe (CASSIOPE/e-POP) satellite was used to receive continuous wave and binary phase shift keyed transmissions from a high-frequency transmitter located in Ottawa, ON, Canada during April 2016 to investigate how the ionosphere affects the polarization characteristics of transionospheric high-frequency radio waves. The spacecraft orientation was continuously slewed to maintain the dipole orientation in a plane perpendicular to the direction toward the transmitter, enabling the first in situ planar polarization determination for continuous wave and binary phase shift keyed modulated radio waves from space at times when the wave frequency is at least 1.58 times the plasma frequency. The Stokes parameters and polarization characteristics were derived from the measured data and interpreted using an existing ray tracing model. For the southern part of the passes, the power was observed to oscillate between the two dipoles of RRI, which was attributed to Faraday rotation of the radio waves. For the first time, a reversal in the rate of change of orientation angle was observed where the minimum in modeled Faraday rotation occurred. The reversal point was poleward of the point of closest approach between the satellite and transmitter; this was explained by the variations of total electron content and component of magnetic field along the direction of propagation. The received signals show both quasi-longitudinal (QL) and quasi-transverse characteristics. South of the transmitter the QL regime is dominant. Around the reversal point, a combination of QL and quasi-transverse nature was observed.

  1. Recovery of Large Angular Scale CMB Polarization for Instruments Employing Variable-Delay Polarization Modulators

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    Miller, N. J.; Chuss, D. T.; Marriage, T. A.; Wollack, E. J.; Appel, J. W.; Bennett, C. L.; Eimer, J.; Essinger-Hileman, T.; Fixsen, D. J.; Harrington, K.; hide

    2016-01-01

    Variable-delay Polarization Modulators (VPMs) are currently being implemented in experiments designed to measure the polarization of the cosmic microwave background on large angular scales because of their capability for providing rapid, front-end polarization modulation and control over systematic errors. Despite the advantages provided by the VPM, it is important to identify and mitigate any time-varying effects that leak into the synchronously modulated component of the signal. In this paper, the effect of emission from a 300 K VPM on the system performance is considered and addressed. Though instrument design can greatly reduce the influence of modulated VPM emission, some residual modulated signal is expected. VPM emission is treated in the presence of rotational misalignments and temperature variation. Simulations of time-ordered data are used to evaluate the effect of these residual errors on the power spectrum. The analysis and modeling in this paper guides experimentalists on the critical aspects of observations using VPMs as front-end modulators. By implementing the characterizations and controls as described, front-end VPM modulation can be very powerful for mitigating 1/ f noise in large angular scale polarimetric surveys. None of the systematic errors studied fundamentally limit the detection and characterization of B-modes on large scales for a tensor-to-scalar ratio of r= 0.01. Indeed, r less than 0.01 is achievable with commensurately improved characterizations and controls.

  2. RECOVERY OF LARGE ANGULAR SCALE CMB POLARIZATION FOR INSTRUMENTS EMPLOYING VARIABLE-DELAY POLARIZATION MODULATORS

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N. J.; Marriage, T. A.; Appel, J. W.; Bennett, C. L.; Eimer, J.; Essinger-Hileman, T.; Harrington, K.; Rostem, K.; Watts, D. J. [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 (United States); Chuss, D. T. [Department of Physics, Villanova University, 800 E Lancaster, Villanova, PA 19085 (United States); Wollack, E. J.; Fixsen, D. J.; Moseley, S. H.; Switzer, E. R., E-mail: Nathan.J.Miller@nasa.gov [Observational Cosmology Laboratory, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-02-20

    Variable-delay Polarization Modulators (VPMs) are currently being implemented in experiments designed to measure the polarization of the cosmic microwave background on large angular scales because of their capability for providing rapid, front-end polarization modulation and control over systematic errors. Despite the advantages provided by the VPM, it is important to identify and mitigate any time-varying effects that leak into the synchronously modulated component of the signal. In this paper, the effect of emission from a 300 K VPM on the system performance is considered and addressed. Though instrument design can greatly reduce the influence of modulated VPM emission, some residual modulated signal is expected. VPM emission is treated in the presence of rotational misalignments and temperature variation. Simulations of time-ordered data are used to evaluate the effect of these residual errors on the power spectrum. The analysis and modeling in this paper guides experimentalists on the critical aspects of observations using VPMs as front-end modulators. By implementing the characterizations and controls as described, front-end VPM modulation can be very powerful for mitigating 1/f noise in large angular scale polarimetric surveys. None of the systematic errors studied fundamentally limit the detection and characterization of B-modes on large scales for a tensor-to-scalar ratio of r = 0.01. Indeed, r < 0.01 is achievable with commensurately improved characterizations and controls.

  3. A Global and Regional Trend Study of the Vertical Distribution of Aerosols As Observed By Caliop

    Science.gov (United States)

    Toth, T. D.; Zhang, J.; Campbell, J. R.; Reid, J. S.; Vaughan, M.

    2014-12-01

    Trends in atmospheric aerosol particle loading have gained increased attention in recent years due to their impact on Earth's radiation budget and global climate change. Past studies have examined this topic through aerosol optical depth (AOD) observations derived from passive satellite sensors such as Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR). However, such passive sensors acquire only column-integrated measurements and thus can provide no insight into the vertical distribution of any AOD trends they might detect. Yet knowledge of aerosol vertical distribution and trends are critical for studies involving aerosol climate impacts and air quality. Using seven and a half years (June 2006 - December 2013) of aerosol profile data from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), we investigate trends in CALIOP-derived AOD at various altitudes throughout the atmospheric column. This differs from existing CALIOP-based climatological studies that focus solely on the mean state of aerosol vertical distribution. Daytime and nighttime analyses are decoupled to account for differences in the vertical structure of the troposphere, and detection sensitivity of CALIOP, between the two regimes. The results of this study are presented globally and for selected regions. Of particular interest are North Africa and Asia, as these are areas with frequently high AOD and have also exhibited trends from passive sensor observations.

  4. THE ATACAMA COSMOLOGY TELESCOPE: THE POLARIZATION-SENSITIVE ACTPol INSTRUMENT

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, R. J. [Department of Physics, West Chester University of Pennsylvania, West Chester, PA 19383 (United States); Ade, P. A. R. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, Wales, CF24 3AA (United Kingdom); Aiola, S. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Angilè, F. E.; Devlin, M. J.; Dicker, S. R. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Amiri, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z4 (Canada); Beall, J. A.; Becker, D. T.; Fowler, J. W.; Fox, A. E.; Gao, J. [NIST Quantum Sensors Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States); Cho, H-M. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Choi, S. K.; Grace, E. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Corlies, P.; Gallardo, P. A. [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Coughlin, K. P.; Datta, R. [Department of Physics, University of Michigan Ann Arbor, MI 48109 (United States); Dünner, R. [Instituto de Astrofísica and Centro de Astro-Ingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago (Chile); and others

    2016-12-01

    The Atacama Cosmology Telescope (ACT) makes high angular resolution measurements of anisotropies in the Cosmic Microwave Background (CMB) at millimeter wavelengths. We describe ACTPol, an upgraded receiver for ACT, which uses feedhorn-coupled, polarization-sensitive detector arrays, a 3° field of view, 100 mK cryogenics with continuous cooling, and meta material antireflection coatings. ACTPol comprises three arrays with separate cryogenic optics: two arrays at a central frequency of 148 GHz and one array operating simultaneously at both 97 GHz and 148 GHz. The combined instrument sensitivity, angular resolution, and sky coverage are optimized for measuring angular power spectra, clusters via the thermal Sunyaev–Zel’dovich (SZ) and kinetic SZ signals, and CMB lensing due to large-scale structure. The receiver was commissioned with its first 148 GHz array in 2013, observed with both 148 GHz arrays in 2014, and has recently completed its first full season of operations with the full suite of three arrays. This paper provides an overview of the design and initial performance of the receiver and related systems.

  5. The Atacama Cosmology Telescope: The Polarization-Sensitive ACTPol Instrument

    Science.gov (United States)

    Thornton, R. J.; Ade, P. A. R.; Aiola, S.; Angile, F. E.; Amiri, M.; Beall, J. A.; Becker, D. T.; Cho, H.-M.; Choi, S. K.; Corlies, P.; hide

    2016-01-01

    The Atacama Cosmology Telescope (ACT) makes high angular resolution measurements of anisotropies in the Cosmic Microwave Background (CMB) at millimeter wavelengths. We describe ACTPol, an upgraded receiver for ACT, which uses feedhorn-coupled, polarization-sensitive detector arrays, a 3deg field of view, 100 mK cryogenics with continuous cooling, and meta material antireflection coatings. ACTPol comprises three arrays with separate cryogenic optics: two arrays at a central frequency of 148 GHz and one array operating simultaneously at both 97 GHz and 148 GHz. The combined instrument sensitivity, angular resolution, and sky coverage are optimized for measuring angular power spectra, clusters via the thermal Sunyaev-Zel'dovich (SZ) and kinetic SZ signals, and CMB lensing due to large-scale structure. The receiver was commissioned with its first 148 GHz array in 2013, observed with both 148 GHz arrays in 2014, and has recently completed its first full season of operations with the full suite of three arrays. This paper provides an overview of the design and initial performance of the receiver and related systems.

  6. Architectures and assessment of next-generation CMB polarization instruments

    Data.gov (United States)

    National Aeronautics and Space Administration — Cosmological inflation predicts a background of gravitational waves that imprint a characteristic polarized pattern on the CMB. This signal is degraded by...

  7. Characterizing Instrumental Effects on Polarization at a Nasmyth focus using NaCo

    OpenAIRE

    de Boer, Joshua; Girard, Julien H.; Mawet, Dimitri; Snik, Frans; Keller, Christoph U.; Milli, Julien

    2014-01-01

    We propose a new calibration scheme to determine the instrumental polarization (IP) and crosstalk induced by either the telescope or an instrument at Nasmyth focus. We measure the polarized blue sky at zenith with VLT/UT4/NaCo for different NaCo derotator and telescope azimuth angles. Taking multiple measurements after rotating both the instrument and the telescope with angles of 90° allows use to determine the IP and most crosstalk components separately for the telescope and the instrument. ...

  8. Evaluating Nighttime CALIOP 0.532 micron Aerosol Optical Depth and Extinction Coefficient Retrievals

    Science.gov (United States)

    Campbell, J. R.; Tackett, J. L.; Reid, J. S.; Zhang, J.; Curtis, C. A.; Hyer, E. J.; Sessions, W. R.; Westphal, D. L.; Prospero, J. M.; Welton, E. J.; hide

    2012-01-01

    NASA Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) Version 3.01 5-km nighttime 0.532 micron aerosol optical depth (AOD) datasets from 2007 are screened, averaged and evaluated at 1 deg X 1 deg resolution versus corresponding/co-incident 0.550 micron AOD derived using the US Navy Aerosol Analysis and Prediction System (NAAPS), featuring two-dimensional variational assimilation of quality-assured NASA Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR) AOD. In the absence of sunlight, since passive radiometric AOD retrievals rely overwhelmingly on scattered radiances, the model represents one of the few practical global estimates available from which to attempt such a validation. Daytime comparisons, though, provide useful context. Regional-mean CALIOP vertical profiles of night/day 0.532 micron extinction coefficient are compared with 0.523/0.532 micron ground-based lidar measurements to investigate representativeness and diurnal variability. In this analysis, mean nighttime CALIOP AOD are mostly lower than daytime (0.121 vs. 0.126 for all aggregated data points, and 0.099 vs. 0.102 when averaged globally per normalised 1 deg. X 1 deg. bin), though the relationship is reversed over land and coastal regions when the data are averaged per normalised bin (0.134/0.108 vs. 0140/0.112, respectively). Offsets assessed within single bins alone approach +/- 20 %. CALIOP AOD, both day and night, are higher than NAAPS over land (0.137 vs. 0.124) and equal over water (0.082 vs. 0.083) when averaged globally per normalised bin. However, for all data points inclusive, NAAPS exceeds CALIOP over land, coast and ocean, both day and night. Again, differences assessed within single bins approach 50% in extreme cases. Correlation between CALIOP and NAAPS AOD is comparable during both day and night. Higher correlation is found nearest the equator, both as a function of sample size and relative signal magnitudes inherent at

  9. Planetary systems in polarized light: Debris disk observations and instrumentation

    Science.gov (United States)

    Millar-Blanchaer, Maxwell A.

    Understanding planet formation is one of the major challenges of modern astronomy. Polarimetry is a powerful tool with which we can confront this challenge. In particular, polarimetric observations can be useful for imaging debris disks and characterizing exoplanet atmospheres. With that in mind, this thesis has been constructed with two main aspects: i) observational studies of two debris disk systems, beta Pic and HD 157587, using the Gemini Planet Imager and ii) the characterization and testing of a new type of diffraction grating, called a polarization grating, that we plan to use for future observations of exoplanet atmospheres. The Gemini Planet Imager is a high-contrast imager that includes a polarimetry mode designed to image circumstellar disks. Here we detail the development of new data analysis techniques that reduce systematics and noise in processed GPI data. We apply these techniques to observations of the beta Pic and HD 157587 debris disks and then fit each disk image to a geometric disk model. The beta Pic disk model's morphology cannot be explained by interactions with the planet beta Pic b, and the presence of a second planet could be invoked to explain the discrepancy. In the case of HD 157587, the disk model's geometric centre is offset from the location of the star, which could be explained by a perturbing planet. Characterization of the planets' interactions with their debris disks is a critical method to gain more information about these two systems. The second component of this thesis focuses on polarization gratings, thin film optical devices that can simultaneously act as polarizing beam splitters and as spectral dispersive elements. Moreover, they can be designed for high diffraction efficiency across a broad wavelength range. These features make polarization gratings useful for many types of astronomical observations. We have carried out laboratory and on-sky test observations using a polarization grating optimized for visible

  10. Sources, Load, Vertical Distribution, and Fate of Wintertime Aerosols North of Svalbard From Combined V4 CALIOP Data, Ground-Based IAOOS Lidar Observations and Trajectory Analysis

    Science.gov (United States)

    Di Biagio, C.; Pelon, J.; Ancellet, G.; Bazureau, A.; Mariage, V.

    2018-01-01

    We have analyzed aerosol properties at the regional scale over high Arctic north of Svalbard between October 2014 and June 2015 from version 4 (V4) CALIOP (Cloud and Aerosol Lidar with Orthogonal Polarization) spaceborne observations and compared results with surface lidar observations from IAOOS (Ice-Atmosphere-Ocean Observing System) platforms. CALIOP data indicate a maximum in aerosol occurrence at the end of winter attributed to low-level (0-2 km) and midtropospheric (2-5 km) particles identified in CALIOP V4 product as being mostly of dust origin. Another maximum was observed in October-December attributed to clean marine particles below 2 km and smoke and dust above. The 532 nm aerosol extinction was in the range 1-8 Mm-1 (0-2 km), 1-18 Mm-1 (2-5 km), and 0-6 Mm-1 (5-10 km), a factor 2 lower compared to values previously reported using CALIOP V3 data set. Aerosols are identified from trajectory analyses to originate mostly from Russia/Europe at all altitudes, and also North America above 2 km, and it is concluded that dust and clean marine types are most probably overrepresented in the analyzed CALIOP data set. It is proposed that most part of dust types are diamond dust, while part of clean marine are polluted species, as corroborated from colocated polarized lidar IAOOS observations. IAOOS observations allowed confirming the identified sensitivity of CALIOP with a particle backscatter coefficient of 0.001 km-1 sr-1 at 532 nm. For optically thicker layers CALIOP is shown to be a valuable tool to follow transport of aerosol layers in the Arctic and identify their possible modifications.

  11. A Statistical Review of CALIOP Version 3 and Version 4 Cloud Aerosol Discrimination

    Science.gov (United States)

    Zeng, S.

    2016-12-01

    The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on board the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission has now delivered a 10-year record of high-resolution profiles of backscatter at 532 nm and 1064 nm and linear depolarization at 532 nm. These long-term active sensor measurements at global scale have led to significant advances in our understanding of the vertical distribution of clouds and aerosols in the atmosphere. In the fall of 2016, the CALIPSO science team is scheduled to release a new version of their cloud and aerosol data products. The new cloud and aerosol discrimination products are derived using updated probability density functions that account for numerous improvements to the CALIOP calibration and the use of the GMAO MERRA-2 meteorological data. Moreover, the CAD algorithm is now applied to all layers detected, thus greatly improving the identification of such features as overshooting convective clouds, stratospheric aerosol layers, and high intensity dust storms. Post-processing modules are added to the standard CAD algorithm to ensure proper identification of (for example) the tenuous edges of cirrus clouds and water clouds lying beneath optically dense smoke layers. This work presents statistical comparisons between the CALIOP version 3 and version 4 data sets. Areas of improvement are highlighted, sources of continuing uncertainty are discussed and a list of best practices for data users is provided.

  12. Instrument development of the CMB polarization POLARBEAR-2 experiment

    Science.gov (United States)

    Siritanasak, Praween; POLARBEAR Collaboration

    2017-06-01

    We present the status of the development of the Polarbear-2 (PB-2) and Simons Array experiments. PB-2 is a ground-based Cosmic Microwave Back- ground (CMB) polarization experiment located at the James Ax observatory in the Atacama desert of Northern Chile. The Simons Array will consist of three PB-2 receivers on three Huan Tran-style telescopes, each containing a multi-chroic detector array. The first new Simons Array receiver, Polarbear- 2A(PB-2A), will be deployed in 2017. The PB-2A focal plane consists of 1,897 lenslet-coupled, dual-polarization, sinuous-antenna-coupled pixels operating at 95 and 150 GHz, making a total of 7,588 polarization-sensitive transition edge sensor (TES) bolometers. In the order to cover both frequencies, we developed broadband two layer anti-reflection (AR) coating for 5.345 mm diameter lenslets using two types of epoxy: Stycast2850FT and Stycast1090. We developed a mass production AR coating methodology that can control the uniformity and shape to within 25 μm error from the designed value. The second (PB-2B) and third (PB-2C) receivers will employ similar technologies and will cover 95, 150, 220 and 280 GHz. The Simons Array will survey 80% of the sky with broad frequency coverage and high resolution, making it a powerful tool to constrain the tensor-to-scalar ratio through measurements of primordial B-modes and the sum of the neutrino masses through measurements of B-modes produced by gravitational lensing.

  13. Improving Daytime Planetary Boundary Layer Height Determination from CALIOP: Validation Based on Ground-Based Lidar Station

    Directory of Open Access Journals (Sweden)

    Zhao Liu

    2017-01-01

    Full Text Available An integrated algorithm by combining the advantages of the wavelet covariance method and the improved maximum variance method was developed to determine the planetary boundary layer height (PBLH from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP measurements, and an aerosol fraction threshold was applied to the integrated algorithm considering the applicability of the two methods. We compared the CALIOP retrieval with the measurements of PBLH derived from nine years of ground-based Lidar synchronous observations located in Lille, north of France. The results indicate that a good correlation (R≥0.79 exists between the PBLHs derived from CALIOP and ground-based Lidar under clear sky conditions. The mean absolute differences of PBLHs are, respectively, of 206 m and 106 m before and after the removal of the aloft aerosol layer. The results under cloudy sky conditions show a lower agreement (R=0.48 in regard of the comparisons performed under clear sky conditions. Besides, the spatial correlation of PBLHs decreases with the increasing spatial distance between CALIOP footprint and Lille observation platform. Based on the above analysis, the PBLHs can be effectively derived by the integrated algorithm under clear sky conditions, while larger mean absolute difference (i.e., 527 m exists under cloudy sky conditions.

  14. POLVSM (Polarized Volume Scattering Meter) instrument: an innovative device to measure the directional and polarized scattering properties of hydrosols.

    Science.gov (United States)

    Chami, Malik; Thirouard, Alexandre; Harmel, Tristan

    2014-10-20

    An innovative instrument dedicated to the multispectral measurements of the directional and polarized scattering properties of the hydrosols, so-called POLVSM, is described. The instrument could be used onboard a ship, as a benchtop instrument, or at laboratory. The originality of the POLVSM concept relies on the use of a double periscopic optical system whose role is (i) to separate the plane containing the light source from the scattering plane containing the sample and the receiver and (ii) to prevent from any specularly reflected light within the sample chamber. As a result, a wide range of scattering angle, namely from 1° to 179°, is covered by the detector. Another originality of the instrument is to measure the Mueller scattering matrix elements, including the degree of polarization. A relevant calibration procedure, which could be of great interest as well for other instruments, is proposed to convert the raw data into physical units. The relative uncertainty in POLVSM data was determined at ± 4.3%. The analysis of measurements of the volume scattering function and degree of polarization performed under controlled conditions for samples dominated either by inorganic hydrosols or phytoplankton monospecific species showed a good consistency with literature, thus confirming the good performance of the POLVSM device. Comparisons of POLVSM data with theoretical calculations showed that Mie theory could reproduce efficiently the measurements of the VSF and degree of polarization for the case of inorganic hydrosols sample, despite the likely non sphericity of these particles as revealed by one of the element of the Mueller matrix. Our results suggested as well that a sophisticated modeling of the heterogeneous internal structure of living cells, or at least, the use of layered sphere models, is needed to correctly predict the directional and polarized effects of phytoplankton on the oceanic radiation. The relevance of performing angularly resolved measurements

  15. Application of the CALIOP Layer Product to Evaluate the Vertical Distribution of Aerosols Estimated by Global Models: AeroCom Phase I Results

    Science.gov (United States)

    Koffi, Brigitte; Schulz, Michael; Breon, Francois-Marie; Griesfeller, Jan; Winker, David; Balkanski, Yves; Bauer, Susanne; Berntsen, Terje; Chin, Mian; Collins, William D.; hide

    2012-01-01

    The CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) layer product is used for a multimodel evaluation of the vertical distribution of aerosols. Annual and seasonal aerosol extinction profiles are analyzed over 13 sub-continental regions representative of industrial, dust, and biomass burning pollution, from CALIOP 2007-2009 observations and from AeroCom (Aerosol Comparisons between Observations and Models) 2000 simulations. An extinction mean height diagnostic (Z-alpha) is defined to quantitatively assess the models' performance. It is calculated over the 0-6 km and 0-10 km altitude ranges by weighting the altitude of each 100 m altitude layer by its aerosol extinction coefficient. The mean extinction profiles derived from CALIOP layer products provide consistent regional and seasonal specificities and a low inter-annual variability. While the outputs from most models are significantly correlated with the observed Z-alpha climatologies, some do better than others, and 2 of the 12 models perform particularly well in all seasons. Over industrial and maritime regions, most models show higher Z-alpha than observed by CALIOP, whereas over the African and Chinese dust source regions, Z-alpha is underestimated during Northern Hemisphere Spring and Summer. The positive model bias in Z-alpha is mainly due to an overestimate of the extinction above 6 km. Potential CALIOP and model limitations, and methodological factors that might contribute to the differences are discussed.

  16. Polar Mesospheric Clouds (PMCs) Observed by the Ozone Monitoring Instrument (OMI) on Aura

    Science.gov (United States)

    DeLand, Matthew T.; Shettle, Eric P.; Levelt, Pieternel F.; Kowalewski, Matthew G.

    2010-01-01

    Backscattered ultraviolet (BUV) instruments designed for measuring stratospheric ozone profiles have proven to be robust tools for observing polar mesospheric clouds (PMCs). These measurements are available for more than 30 years, and have been used to demonstrate the existence of long-term variations in PMC occurrence frequency and brightness. The Ozone Monitoring Instrument (OMI) on the EOS Aura satellite provides new and improved capabilities for PMC characterization. OMI uses smaller pixels than previous BUV instruments, which increases its ability to identify PMCs and discern more spatial structure, and its wide cross-track viewing swath provides full polar coverage up to 90 latitude every day in both hemispheres. This cross-track coverage allows the evolution of PMC regions to be followed over several consecutive orbits. Localized PMC variations determined from OMI measurements are consistent with coincident SBUV/2 measurements. Nine seasons of PMC observations from OMI are now available, and clearly demonstrate the advantages of these measurements for PMC analysis.

  17. The Impact of Caliop Aerosol Profiling: How Z Influences the X, Y Satellite Perspective

    Science.gov (United States)

    Campbell, J. R.; Alfaro-Contreras, R.; Buchard, V.; Toth, T. D.; Vaughan, M.; Zhang, J.

    2014-12-01

    The ever-burgeoning satellite remote sensing era has significantly improved our understanding of the role aerosol particles play in the earth-atmosphere system. Instruments such as MODIS, MISR, OMI, AVHRR, and now VIIRS, among others, are meeting a growing number of observational demands necessary for characterizing aerosol particle influence, on processes such as surface air quality, direct and semi-direct forcing and cloud indirect effects. While these passive sensors have grown to represent the community's fundamental global aerosol observing core, their datasets represent, almost exclusively, a column-integrated view of atmospheric aerosols. In contrast, however, aerosol-climate interaction is inherently sensitive to the vertical distribution of aerosol particle presence. Though the CALIOP instrument, with its relatively limited profiling swath, offers a much smaller observational scale compared with passive imagers, active-sensor aerosol profiling is increasingly adding the necessary vertical perspective required to challenge and fully characterize what has become a predominant two-dimensional global perception of aerosols. In this talk, we highlight the impact of CALIOP-based profiling, and describe how the critical third dimension is contributing to this knowledge. We introduce aerosol scale-heights and the contribution of near-surface particle presence relative to column-integrated aerosol optical depths. We describe the impact of particle profile diffusivity relative to passive-based estimates of surface air quality. The impact of accurate vertical profiling in global modeling systems is conceptualized, through benefits to downwind forecasting from accurate initialization. Sensitivities in semi-direct regional heating rate estimates are shown as a function of model-constrained aerosol vertical profiling. Finally, we highlight perhaps the most important CALIOP observation of all, relative to the passive sensors: the presence of optically-thin cirrus clouds

  18. Wide-angle polarization analysis with 3He for neutron scattering instrumentation at the JCNS

    Science.gov (United States)

    Ioffe, A.; Babcock, E.; Pipich, V.; Radulescu, A.

    2011-06-01

    Polarization analysis is an important technique for polarized neutron scattering as it allows one to obtain the full information about the vector magnetization in the sample that is critically important for detailed understanding of physical properties of molecular magnets, new superconductors, spin electronic and magnetic nanostructures, as well as the self-organization of magnetic nanostructures. In the simplified 1-dimensional version polarization analysis allows for the separation of coherent and incoherent scattering, making it a potentially important technique for studies of non-deuterated biological objects that themselves produce unavoidable background. We compare some of the major considerations between two different methods for the polarization analysis - supermirror based analyzers and polarized 3He neutron spin filters and point out when the latter is beneficial from the point of view of our neutron experiments and instrumentation. We will also discuss some specific requirements to such neutron spin filters and summarize the classes of instrumentation where they will be applied at the JCNS. Finally we will describe a successful application for small-angle neutron scattering from a biological sample.

  19. Wide-angle polarization analysis with 3He for neutron scattering instrumentation at the JCNS

    International Nuclear Information System (INIS)

    Ioffe, A; Babcock, E; Pipich, V; Radulescu, A

    2011-01-01

    Polarization analysis is an important technique for polarized neutron scattering as it allows one to obtain the full information about the vector magnetization in the sample that is critically important for detailed understanding of physical properties of molecular magnets, new superconductors, spin electronic and magnetic nanostructures, as well as the self-organization of magnetic nanostructures. In the simplified 1-dimensional version polarization analysis allows for the separation of coherent and incoherent scattering, making it a potentially important technique for studies of non-deuterated biological objects that themselves produce unavoidable background. We compare some of the major considerations between two different methods for the polarization analysis - supermirror based analyzers and polarized 3 He neutron spin filters and point out when the latter is beneficial from the point of view of our neutron experiments and instrumentation. We will also discuss some specific requirements to such neutron spin filters and summarize the classes of instrumentation where they will be applied at the JCNS. Finally we will describe a successful application for small-angle neutron scattering from a biological sample.

  20. Orbiting Carbon Observatory-2 (OCO-2) Cloud Screening; Validation Against Collocated MODIS and Initial Comparison to CALIOP Data

    Science.gov (United States)

    Taylor, Thomas E.; O'Dell, Christopher W.; Frankenberg, Christian; Partain, Philip; Cronk, Heather W.; Savtchenko, Andrey; Nelson, Robert R.; Rosenthal, Emily J.; Chang, Albert; Crisp, David; hide

    2015-01-01

    platform, and the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite, are used as a reference to access the accuracy and strengths and weaknesses of the OCO-2 screening algorithms. The combination of the ABP and IDP algorithms is shown to provide very robust and complimentary cloud filtering as compared to the results from MODIS and CALIOP. With idealized algorithm tuning to allow throughputs of 20-25%, correct classification of scenes, i.e., accuracies, are found to be ' 80-90% over several orbit repeat cycles in both the win ter and spring time for the three main viewing configurations of OCO-2; nadir-land, glint-land and glint-water. Investigation unveiled no major spatial or temporal dependencies, although slight differences in the seasonal data sets do exist and classification tends to be more problematic with increasing solar zenith angle and when surfaces are covered in snow and ice. An in depth analysis on both a simulated data set and real OCO-2 measurements against CALIOP highlight the strength of the ABP in identifying high, thin clouds while it often misses clouds near the surface even when the optical thickness is greater than 1. Fortunately, by combining the ABP with the IDP, the number of thick low clouds passing the preprocessors is partially mitigated.

  1. Multi-instrument probing of the polar ionosphere under steady northward IMF

    Directory of Open Access Journals (Sweden)

    S. E. Pryse

    2000-01-01

    Full Text Available Observations are presented of the polar ionosphere under steady, northward IMF. The measurements, made by six complementary experimental techniques, including radio tomography, all-sky and meridian scanning photometer optical imaging, incoherent and coherent scatter radars and satellite particle detection, reveal plasma parameters consistent with ionospheric signatures of lobe reconnection. The optical green-line footprint of the reconnection site is seen to lie in the sunward plasma convection of the lobe cells. Downstream in the region of softer precipitation the reverse energy dispersion of the incoming ions can be identified. A steep latitudinal density gradient at the equatorward edge of the precipitation identifies the general location of an adiaroic boundary, separating the open field lines of polar lobe cells from the closed field of viscous-driven cells. Enhancements in plasma density to the south of the gradient are interpreted as ionisation being reconfigured as it is thrust against the boundary by the antisunward flow of the viscous cells near noon. Each of the instruments individually provides valuable information on certain aspects of the ionosphere, but the paper demonstrates that taken together the different experiments complement each other to give a consistent and comprehensive picture of the dayside polar ionosphere..Key words. Ionosphere (polar ionosphere · Magnetospheric physics (magnetosphere-ionosphere interactions; polar cap phenomena

  2. Multi-instrument probing of the polar ionosphere under steady northward IMF

    Directory of Open Access Journals (Sweden)

    S. E. Pryse

    Full Text Available Observations are presented of the polar ionosphere under steady, northward IMF. The measurements, made by six complementary experimental techniques, including radio tomography, all-sky and meridian scanning photometer optical imaging, incoherent and coherent scatter radars and satellite particle detection, reveal plasma parameters consistent with ionospheric signatures of lobe reconnection. The optical green-line footprint of the reconnection site is seen to lie in the sunward plasma convection of the lobe cells. Downstream in the region of softer precipitation the reverse energy dispersion of the incoming ions can be identified. A steep latitudinal density gradient at the equatorward edge of the precipitation identifies the general location of an adiaroic boundary, separating the open field lines of polar lobe cells from the closed field of viscous-driven cells. Enhancements in plasma density to the south of the gradient are interpreted as ionisation being reconfigured as it is thrust against the boundary by the antisunward flow of the viscous cells near noon. Each of the instruments individually provides valuable information on certain aspects of the ionosphere, but the paper demonstrates that taken together the different experiments complement each other to give a consistent and comprehensive picture of the dayside polar ionosphere..

    Key words. Ionosphere (polar ionosphere · Magnetospheric physics (magnetosphere-ionosphere interactions; polar cap phenomena

  3. The Thirty Gigahertz Instrument Receiver for the QUIJOTE Experiment: Preliminary Polarization Measurements and Systematic-Error Analysis.

    Science.gov (United States)

    Casas, Francisco J; Ortiz, David; Villa, Enrique; Cano, Juan L; Cagigas, Jaime; Pérez, Ana R; Aja, Beatriz; Terán, J Vicente; de la Fuente, Luisa; Artal, Eduardo; Hoyland, Roger; Génova-Santos, Ricardo

    2015-08-05

    This paper presents preliminary polarization measurements and systematic-error characterization of the Thirty Gigahertz Instrument receiver developed for the QUIJOTE experiment. The instrument has been designed to measure the polarization of Cosmic Microwave Background radiation from the sky, obtaining the Q, U, and I Stokes parameters of the incoming signal simultaneously. Two kinds of linearly polarized input signals have been used as excitations in the polarimeter measurement tests in the laboratory; these show consistent results in terms of the Stokes parameters obtained. A measurement-based systematic-error characterization technique has been used in order to determine the possible sources of instrumental errors and to assist in the polarimeter calibration process.

  4. Neutron xyz – polarization analysis at a time-of-flight instrument

    Directory of Open Access Journals (Sweden)

    Ehlers G.

    2015-01-01

    Full Text Available When implementing a dedicated polarization analysis setup at a neutron time-of-flight instrument with a large area detector, one faces enormous challenges. Nevertheless, significant progress has been made towards this goal over the last few years. This paper addresses systematic limitations of the traditional method that is used to make these measurements, and a possible strategy to overcome these limitations. This will be important, for diffraction as well as inelastic experiments, where the scattering occurs mostly out-of-plane.

  5. STEREO DERIVED CLOUD TOP HEIGHT CLIMATOLOGY OVER GREENLAND FROM 20 YEARS OF THE ALONG TRACK SCANNING RADIOMETER (ATSR INSTRUMENTS

    Directory of Open Access Journals (Sweden)

    D. Fisher

    2012-07-01

    Full Text Available Current algorithms for the determination of cloud top height and cloud fraction in Polar Regions tend to provide unreliable results, particularly in the presence of isothermal conditions within the atmosphere. Alternative methods to determine cloud top heights in such regions effectively, from space borne sensors, are currently limited to stereo-photogrammetry and active sensing methods, such as LiDAR. Here we apply the modified census transform to one month of AATSR stereo data from June 2008. AATSR is unique in that it is the only space borne stereo capable instrument providing data continuously in both the visible, near infrared and thermal channels. This allows for year round imaging of the poles and therefore year round cloud top height and cloud fraction estimation. We attempt a preliminary validation of the stereo retrieved cloud top height measurements from AATSR against collocated cloud height measurements from the CALIOP LiDAR instrument. CALIOP provides an excellent validation tool due to its excellent height resolution of between 30-60 meters. In this validation, a pair of collocated swaths is assessed with a total of 154 inter-comparisons; the results show that AATSR correlates well with CALIOP cloud base layers with an R2 score of 0.71. However, in all cases AATSR appears to be underestimating the cloud top height compared to CALIOP, the causes for this are currently not fully understood and more extensive inter-comparisons are required. Once validation is completed a processing chain is in place to process the entire ATSR time-series data generating a 20 year cloud top height dataset for Greenland.

  6. LabVIEW-based control software for para-hydrogen induced polarization instrumentation

    International Nuclear Information System (INIS)

    Agraz, Jose; Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

    2014-01-01

    The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10 000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ( 13 C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (B o ), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of 13 C based endogenous contrast agents used in molecular imaging

  7. LabVIEW-based control software for para-hydrogen induced polarization instrumentation.

    Science.gov (United States)

    Agraz, Jose; Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

    2014-04-01

    The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10,000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ((13)C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (Bo), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of (13)C based endogenous contrast agents used in molecular imaging.

  8. GLORI: A GNSS-R Dual Polarization Airborne Instrument for Land Surface Monitoring.

    Science.gov (United States)

    Motte, Erwan; Zribi, Mehrez; Fanise, Pascal; Egido, Alejandro; Darrozes, José; Al-Yaari, Amen; Baghdadi, Nicolas; Baup, Frédéric; Dayau, Sylvia; Fieuzal, Remy; Frison, Pierre-Louis; Guyon, Dominique; Wigneron, Jean-Pierre

    2016-05-20

    Global Navigation Satellite System-Reflectometry (GNSS-R) has emerged as a remote sensing tool, which is complementary to traditional monostatic radars, for the retrieval of geophysical parameters related to surface properties. In the present paper, we describe a new polarimetric GNSS-R system, referred to as the GLObal navigation satellite system Reflectometry Instrument (GLORI), dedicated to the study of land surfaces (soil moisture, vegetation water content, forest biomass) and inland water bodies. This system was installed as a permanent payload on a French ATR42 research aircraft, from which simultaneous measurements can be carried out using other instruments, when required. Following initial laboratory qualifications, two airborne campaigns involving nine flights were performed in 2014 and 2015 in the Southwest of France, over various types of land cover, including agricultural fields and forests. Some of these flights were made concurrently with in situ ground truth campaigns. Various preliminary applications for the characterisation of agricultural and forest areas are presented. Initial analysis of the data shows that the performance of the GLORI instrument is well within specifications, with a cross-polarization isolation better than -15 dB at all elevations above 45°, a relative polarimetric calibration accuracy better than 0.5 dB, and an apparent reflectivity sensitivity better than -30 dB, thus demonstrating its strong potential for the retrieval of land surface characteristics.

  9. Laboratory measurements for the wavelength dependence of the linear polarization with the PROGRA2 instruments

    Science.gov (United States)

    Renard, Jean-Baptiste; Hadamcik, Edith; Levasseur-Regourd, Anny-Chantal; Carrasco, Nathalie; Couté, Benoit; Duverger, Vincent; Guerrini, Vincent

    2017-04-01

    Clouds of solid particles are present in many regions of the Solar System (comets, interplanetary dust cloud, planetary atmospheres). These clouds can be remotely studied by the light they scatter. There is a need for a data base of the light scattered by a large variety of samples at different wavelengths to interpret such measurements. The PROGRA2 instruments are used for this purpose. The PROGRA2 instruments, PROGRA2-VIS and PROGRA2-IR, are imaging polarimeters with a rotating arm to change the phase angle (angle between directions of illumination and observation). They allow to retrieve the complete polarization phase function between 10° and 165°. The light sources are at around 550 and 650 nm for PROGRA2-VIS, and 1000 and 1500 nm for PROGRA2-IR. The detectors are cameras, with a spatial resolution between 20 and 40 micrometers per pixel (PROGRA2-IR uses now new high sensitivity cameras). Measurements are conducted in the laboratory by an air draught technique for grains smaller than about 20 micrometers (which can be included in porous aggregates), and during parabolic flights on-board the A300 ZeroG and now the A310 ZeroG for larger grains; these flights campaigns are funded by the French and European Space Agencies. Hundreds of scattering phase functions have been obtained since 20 years, for a large number of samples (sands, silicon carbide, basalt, volcanic ashes, lunar and Martian simulants, tholins, meteoritic material, black carbon, carbonaceous compounds, …); the main results are available at www.icare.univ-lille1.fr/progra2/. Several samples have been already studied by the two instruments, showing a large diversity of wavelength dependences, from close-to-zero dependence for yellow and ocher sand grains to high dependence for silicon carbide and anthracite grains. These variations should be related to the wavelength dependence of the real and imaginary parts of the refractive index of the particles. We present a summary of the main results of

  10. The Thirty Gigahertz Instrument Receiver for the QUIJOTE Experiment: Preliminary Polarization Measurements and Systematic-Error Analysis

    Directory of Open Access Journals (Sweden)

    Francisco J. Casas

    2015-08-01

    Full Text Available This paper presents preliminary polarization measurements and systematic-error characterization of the Thirty Gigahertz Instrument receiver developed for the QUIJOTE experiment. The instrument has been designed to measure the polarization of Cosmic Microwave Background radiation from the sky, obtaining the Q, U, and I Stokes parameters of the incoming signal simultaneously. Two kinds of linearly polarized input signals have been used as excitations in the polarimeter measurement tests in the laboratory; these show consistent results in terms of the Stokes parameters obtained. A measurement-based systematic-error characterization technique has been used in order to determine the possible sources of instrumental errors and to assist in the polarimeter calibration process.

  11. Arctic Observing Experiment - An Assessment of Instruments Used to Monitor the Polar Environments

    Science.gov (United States)

    Rigor, I. G.; Johnson, J.; Clemente-Colon, P.; Nghiem, S. V.; Hall, D. K.; Woods, J. E.; Valentic, T. A.; Henderson, G. R.; Marshall, C.; Gallage, C.; Zook, J.; Davis, Z.

    2014-12-01

    To understand and predict weather and climate require an accurate observing network that measures the fundamental meteorological parameters: temperature, air pressure, and wind. Measuring these parameters autonomously in the polar regions is especially challenging. To assess the accuracy of polar measurement networks, we established the Arctic Observing Experiment (AOX) test site in March 2013 at the Department of Energy (DOE) Atmospheric Radiation and Meteorology (ARM) site in Barrow, Alaska. We deployed a myriad of data loggers and autonomous buoys, which represent most of the instruments that are commonly deployed by the International Arctic Buoy Programme (IABP) to measure temperature, air pressure and wind. Estimates of temperature over this area have also been analyzed from satellites (e.g., using the Moderate-resolution Imaging Spectroradiometer (MODIS) ice-surface temperature (IST)) product, and can complement data from in-situ sensors and provide consistent measurements under clear-sky conditions. Preliminary results reveal that some of the buoys are susceptible to solar heating, icing can block barometers for short periods, and frosting may insulate air temperature sensors and freeze-lock anemometers. Some of these issues may be addressed by simply painting the buoys white to reduce solar heating of the buoys, and using better temperature shields and barometer ports. Nevertheless, frosting of ultrasonic and mechanical anemometers remains a significant challenge. These results will be useful to initiate a protocol to obtain accurate and consistent measurements from the IABP, the Arctic Observing Network (AON), the International Program for Antarctic Buoys, and the Southern Ocean Observing System to monitor polar environments.

  12. Characterizing the Vertical Profile of Aerosol Particle Extinction and Linear Depolarization over Southeast Asia and the Maritime Continent: The 2007-2009 View from CALIOP

    Science.gov (United States)

    Campbell, James R.; Reid, Jeffrey S.; Westphal, Douglas L.; Zhang, Jianglong; Tackett, Jason L.; Chew, Boon Ning; Welton, Ellsworth J.; Shimizu, Atsushi; Sugimoto, Nobuo; Aoki, Kazuma; hide

    2012-01-01

    Vertical profiles of 0.532 µm aerosol particle extinction coefficient and linear volume depolarization ratio are described for Southeast Asia and the Maritime Continent. Quality-screened and cloud-cleared Version 3.01 Level 2 NASA Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) 5-km Aerosol Profile datasets are analyzed from 2007 to 2009. Numerical simulations from the U.S. Naval Aerosol Analysis and Predictive System (NAAPS), featuring two-dimensional variational assimilation of NASA Moderate Resolution Imaging Spectroradiometer and Multi-angle Imaging Spectro- Radiometer quality-assured datasets, combined with regional ground-based lidar measurements, are considered for assessing CALIOP retrieval performance, identifying bias, and evaluating regional representativeness. CALIOP retrievals of aerosol particle extinction coefficient and aerosol optical depth (AOD) are high over land and low over open waters relative to NAAPS (0.412/0.312 over land for all data points inclusive, 0.310/0.235 when the per bin average is used and each is treated as single data points; 0.102/0.151 and 0.086/0.124, respectively, over ocean). Regional means, however, are very similar (0.180/0.193 for all data points and 0.155/0.159 when averaged per normalized bin), as the two factors offset one another. The land/ocean offset is investigated, and discrepancies attributed to interpretation of particle composition and a-priori assignment of the extinction-to-backscatter ratio ("lidar ratio") necessary for retrieving the extinction coefficient from CALIOP signals. Over land, NAAPS indicates more dust present than CALIOP algorithms are identifying, indicating a likely assignment of a higher lidar ratio representative of more absorptive particles. NAAPS resolvesmore smoke overwater than identified with CALIOP, indicating likely usage of a lidar ratio characteristic of less absorptive particles to be applied that biases low AOD there. Over open waters except within the Bay of Bengal

  13. CALIOPE airborne CO{sub 2} DIAL (CACDI) system design

    Energy Technology Data Exchange (ETDEWEB)

    Mietz, D.; Archuleta, B.; Archuleta, J. [and others

    1997-09-01

    Los Alamos National Laboratory is currently developing an airborne CO{sub 2} Differential Absorption Lidar (DIAL) system based on second generation technology demonstrated last summer at NTS. The CALIOPE Airborne CO{sub 2} DIAL (CACDI) system requirements have been compiled based on the mission objectives and SONDIAL model trade studies. Subsystem designs have been developed based on flow down from these system requirements, as well as experience gained from second generation ground tests and N-ABLE (Non-proliferation AirBorne Lidar Experiments) airborne experiments. This paper presents the CACDI mission objectives, system requirements, the current subsystem design, and provides an overview of the airborne experimental plan.

  14. Aerosol and Cloud Observations and Data Products by the GLAS Polar Orbiting Lidar Instrument

    Science.gov (United States)

    Spinhirne, J. D.; Palm, S. P.; Hlavka, D. L.; Hart, W. D.; Mahesh, A.; Welton, E. J.

    2005-01-01

    The Geoscience Laser Altimeter System (GLAS) launched in 2003 is the first polar orbiting satellite lidar. The instrument was designed for high performance observations of the distribution and optical scattering cross sections of clouds and aerosol. The backscatter lidar operates at two wavelengths, 532 and 1064 nm. Both receiver channels meet and exceed their design goals, and beginning with a two month period through October and November 2003, an excellent global lidar data set now exists. The data products for atmospheric observations include the calibrated, attenuated backscatter cross section for cloud and aerosol; height detection for multiple cloud layers; planetary boundary layer height; cirrus and aerosol optical depth and the height distribution of aerosol and cloud scattering cross section profiles. The data sets are now in open release through the NASA data distribution system. The initial results on global statistics for cloud and aerosol distribution has been produced and in some cases compared to other satellite observations. The sensitivity of the cloud measurements is such that the 70% global cloud coverage result should be the most accurate to date. Results on the global distribution of aerosol are the first that produce the true height distribution for model inter-comparison.

  15. Multi-instrument observation of two different types of polar cap aurora occurring simultaneously during northward IMF

    Science.gov (United States)

    Reidy, J. A.; Fear, R. C.; Lanchester, B. S.; Whiter, D. K.; Kavanagh, A. J.; Paxton, L. J.; Zhang, Y.

    2016-12-01

    Polar cap aurora are a phenomena associated with periods of northwards IMF. By studying their appearance and formation, we can gain valuable information on the configuration of Earth's magnetosphere during the less understood `quiet' periods that occur approximately half of the time. Observations of high latitude aurora from multiple instruments on 19 January 2008 are presented, including almost simultaneous observations of the northern and southern auroral regions from the Special Sensor Ultra-violet Spectrographic Imager (SSUSI) instruments on board Defence Meteorological Satellite Programme (DMSP) spacecraft F16 and F17. SuperDARN flows are also explored in both hemispheres during the event. In the northern hemisphere, two high latitude structures were seen on opposite sides of the polar cap during the same interval. The energies of the precipitating electrons above the structure on the duskside was estimated to vary between 2-11 keV using the Auroral Structure and Kinetics (ASK) instrument in conjunction with the Southampton ion chemistry model. Further analysis of this structure revealed it to be formed on closed field lines that had protruded into the polar cap, consistent with the mechanism proposed for transpolar arcs. However this structure did not cross the entire polar cap but remained, in the northern hemisphere, at approximately 80° magnetic latitude for at least 40 minutes. This protrusion is hence suggested to be an example of a `failed transpolar arc'. The structure seen on the dawnside of the northern polar cap was analysed using DMSP particle spectrograph data. It was found to be associated with electron precipitation energies lower than 1 keV and no ion signature were present. Hence it is suggested that this sun-aligned structure is consistent with the common low intensity arcs formed by accelerated polar rain. The study shows there are at least two types of high latitude aurora occurring simultaneously during northwards IMF.

  16. MIPAS detection of cloud and aerosol particle occurrence in the UTLS with comparison to HIRDLS and CALIOP

    Directory of Open Access Journals (Sweden)

    H. Sembhi

    2012-10-01

    Full Text Available Satellite infrared emission instruments require efficient systems that can separate and flag observations which are affected by clouds and aerosols. This paper investigates the identification of cloud and aerosols from infrared, limb sounding spectra that were recorded by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS, a high spectral resolution Fourier transform spectrometer on the European Space Agency's (ESA ENVISAT (Now inoperative since April 2012 due to loss of contact. Specifically, the performance of an existing cloud and aerosol particle detection method is simulated with a radiative transfer model in order to establish, for the first time, confident detection limits for particle presence in the atmosphere from MIPAS data. The newly established thresholds improve confidence in the ability to detect particle injection events, plume transport in the upper troposphere and lower stratosphere (UTLS and better characterise cloud distributions utilising MIPAS spectra. The method also provides a fast front-end detection system for the MIPClouds processor; a processor designed for the retrieval of macro- and microphysical cloud properties from the MIPAS data.

    It is shown that across much of the stratosphere, the threshold for the standard cloud index in band A is 5.0 although threshold values of over 6.0 occur in restricted regimes. Polar regions show a surprising degree of uncertainty at altitudes above 20 km, potentially due to changing stratospheric trace gas concentrations in polar vortex conditions and poor signal-to-noise due to cold atmospheric temperatures. The optimised thresholds of this study can be used for much of the time, but time/composition-dependent thresholds are recommended for MIPAS data for the strongly perturbed polar stratosphere. In the UT, a threshold of 5.0 applies at 12 km and above but decreases rapidly at lower altitudes. The new thresholds are shown to allow much more sensitive

  17. Retrieval of Ocean Subsurface Particulate Backscattering Coefficient from Space-Borne CALIOP Lidar Measurement

    Science.gov (United States)

    Lu, Xiaomei; Hu, Yongxiang; Pelon, Jacques; Trepte, Chip; Liu, Katie; Rodier, Sharon; Zeng, Shan; Luckher, Patricia; Verhappen, Ron; Wilson, Jamie; hide

    2016-01-01

    A new approach has been proposed to determine ocean subsurface particulate backscattering coefficient bbp from CALIOP 30deg off-nadir lidar measurements. The new method also provides estimates of the particle volume scattering function at the 180deg scattering angle. The CALIOP based layer-integrated lidar backscatter and particulate backscattering coefficients are compared with the results obtained from MODIS ocean color measurements. The comparison analysis shows that ocean subsurface lidar backscatter and particulate backscattering coefficient bbp can be accurately obtained from CALIOP lidar measurements, thereby supporting the use of space-borne lidar measurements for ocean subsurface studies.

  18. CALIOP-based Biomass Burning Smoke Plume Injection Height

    Science.gov (United States)

    Soja, A. J.; Choi, H. D.; Fairlie, T. D.; Pouliot, G.; Baker, K. R.; Winker, D. M.; Trepte, C. R.; Szykman, J.

    2017-12-01

    Carbon and aerosols are cycled between terrestrial and atmosphere environments during fire events, and these emissions have strong feedbacks to near-field weather, air quality, and longer-term climate systems. Fire severity and burned area are under the control of weather and climate, and fire emissions have the potential to alter numerous land and atmospheric processes that, in turn, feedback to and interact with climate systems (e.g., changes in patterns of precipitation, black/brown carbon deposition on ice/snow, alteration in landscape and atmospheric/cloud albedo). If plume injection height is incorrectly estimated, then the transport and deposition of those emissions will also be incorrect. The heights to which smoke is injected governs short- or long-range transport, which influences surface pollution, cloud interaction (altered albedo), and modifies patterns of precipitation (cloud condensation nuclei). We are working with the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) science team and other stakeholder agencies, primarily the Environmental Protection Agency and regional partners, to generate a biomass burning (BB) plume injection height database using multiple platforms, sensors and models (CALIOP, MODIS, NOAA HMS, Langley Trajectory Model). These data have the capacity to provide enhanced smoke plume injection height parameterization in regional, national and international scientific and air quality models. Statistics that link fire behavior and weather to plume rise are crucial for verifying and enhancing plume rise parameterization in local-, regional- and global-scale models used for air quality, chemical transport and climate. Specifically, we will present: (1) a methodology that links BB injection height and CALIOP air parcels to specific fires; (2) the daily evolution of smoke plumes for specific fires; (3) plumes transport and deposited on the Greenland Ice Sheet; and (4) compare CALIOP-derived smoke plume injection

  19. Polarizers tuned at key far-UV spectral lines for space instrumentation

    Science.gov (United States)

    Larruquert, Juan I.; Malvezzi, A. Marco; Rodríguez-de Marcos, Luis; Giglia, Angelo; Gutiérrez-Luna, Nuria; Espinosa-Yáñez, Lucía.; Honrado-Benítez, Carlos; Aznárez, José A.; Massone, Giuseppe; Capobianco, Gerardo; Fineschi, Silvano; Nannarone, Stefano

    2017-05-01

    Polarimetry is a valuable technique to help us understand the role played by the magnetic field of the coronal plasma in the energy transfer processes from the inner parts of the Sun to the outer space. Polarimetry in the far ultraviolet (FUV: 100-200 nm), which must be performed from space due to absorption in terrestrial atmosphere, supplies fundamental data of processes that are governed by the Doppler and Hanle effects on resonantly scattered line-emission. To observe these processes there are various key spectral lines in the FUV, from which H I Lyman α (121.6 nm) is the strongest one. Hence some solar physics missions that have been proposed or are under development plan to perform polarimetry at 121.6 nm, like the suborbital missions CLASP I (2015) and CLASP II (2018), and the proposed solar missions SolmeX and COMPASS and stellar mission Arago. Therefore, the development of efficient FUV linear polarizers may benefit these and other possible future missions. C IV (155 nm) and Mg II (280 nm) are other spectral lines relevant for studies of solar and stellar magnetized atmospheres. High performance polarizers can be obtained with optimized coatings. Interference coatings can tune polarizers at the spectral line(s) of interest for solar and stellar physics. Polarizing beamsplitters consist in polarizers that separate one polarization component by reflection and the other by transmission, which enables observing the two polarization components simultaneously with a single polarizer. They involve the benefit of a higher efficiency in collection of polarization data due to the use of a single polarizer for the two polarization components and they may also facilitate a simplified design for a space polarimeter. We present results on polarizing beamsplitters tuned either at 121.6 nm or at the pair of 155 and 280 nm spectral lines.

  20. The View from the Top: CALIOP Ice Water Content in the Uppermost Layer of Tropical Cyclones

    Science.gov (United States)

    Avery, Melody A.; Deng, Min; Garnier, Anne; Heymsfield, Andrew; Pelon, Jacques; Powell, Kathleen A.; Trepte, Charles R.; Vaughan, Mark A.; Winker, David M.; Young, Stuart

    2012-01-01

    NASA's CALIPSO satellite carries both the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP) and the Imaging Infrared Radiometer (IIR). The lidar is ideally suited to viewing the very top of tropical cyclones, and the IIR provides critical optical and microphysical information. The lidar and the IIR data work together to understand storm clouds since they are perfectly co-located, and big tropical cyclones provide an excellent complex target for comparing the observations. There is a lot of information from these case studies for understanding both the observations and the tropical cyclones, and we are just beginning to scratch the surface of what can be learned. Many tropical cyclone cloud particle measurements are focused on the middle and lower regions of storms, but characterization of cyclone interaction with the lowermost stratosphere at the upper storm boundary may be important for determining the total momentum and moisture transport budget, and perhaps for predicting storm intensity as well. A surprising amount of cloud ice is to be found at the very top of these big storms.

  1. New infrared solid state laser materials for CALIOPE

    International Nuclear Information System (INIS)

    DeLoach, L.D.; Page, R.H.; Wilke, G.D.

    1994-01-01

    Tunable infrared laser light may serve as a useful means by which to detect the presence of the targeted effluents. Since optical parametric oscillators (OPOs) have proven to be a versatile method of generating coherent light from the ultraviolet to the mid-infrared, this technology is a promising choice by which to service the CALIOPE applications. In addition, since some uncertainty remains regarding the precise wavelengths and molecules that will be targeted, the deployment of OPOs retains the greatest amount of wavelength flexibility. Another approach that the authors are considering is that of generating tunable infrared radiation directly with a diode-pumped solid state laser (DPSSL). One important advantage of a DPSSL is that it offers flexible pulse format modes that can be tailored to meet the needs of a particular application and target molecule. On the other hand, direct generation by a tunable DPSSL will generally be able to cover a more limited wavelength range than is possible with OPO technology. In support of the CALIOPE objectives the authors are exploring the potential for laser action among a class of materials comprised of transition metal-doped zinc chalcogenide crystals (i.e., ZnS, ZnSe and ZnTe). The Cr 2+ , Co 2+ and Ni 2+ dopants were selected as the most favorable candidates, on the basis of their documented spectral properties in the scientific literature. Thus far, the authors have characterized the absorption and emission properties of these ions in the ZnS and ZnSe crystals. The absorption spectra are used to determine the preferred wavelength at which the crystal should be pumped, while the emission spectra reveal the extent of the tuning range potentially offered by the material. In addition, measurements of the emission lifetime as a function of temperature turn out to be quite useful, since this data is suggestive of the room temperature emission yield

  2. Instrumentations in x-ray plasma polarization spectroscopy. Crystal spectrometer, polarimeter and detectors for astronomical observations

    Energy Technology Data Exchange (ETDEWEB)

    Baronova, Elena O.; Stepanenko, Mikhail M. [RRC Kurchatov Institute, Nuclear Fusion Institute, Moscow (Russian Federation); Jakubowski, Lech [Soltan Institute for Nuclear Studies, Swierk-Otwock (Poland); Tsunemi, Hiroshi [Osaka Univ., Graduate School of Science, Osaka (Japan)

    2002-08-01

    This report discusses the various problems which are encountered when a crystal spectrometer is used for the purpose of observing polarized x-ray lines. A polarimeter is proposed based on the novel idea of using two series of equivalent atomic planes in a single crystal. The present status of the astronomical x-ray detection techniques are described with emphasis on two dimensional detectors which are polarization sensitive. (author)

  3. Characterisation of dust aerosols in the infrared from IASI and comparison with PARASOL, MODIS, MISR, CALIOP, and AERONET observations

    Directory of Open Access Journals (Sweden)

    S. Peyridieu

    2013-06-01

    Full Text Available Infrared Atmospheric Sounder Interferometer (IASI observations covering the period from July 2007 to December 2011 are interpreted in terms of monthly mean, 1°×1°, 10 μm dust Aerosol Optical Depth (AOD, mean altitude and coarse mode effective radius. The geographical study area includes the northern tropical Atlantic and the northwest Arabian Sea, both characterised by strong, regular dust events. The method developed relies on the construction of Look-Up-Tables computed for a large selection of atmospheric situations and observing conditions. At a regional scale, a good agreement is found between IASI-retrieved 10 μm AOD and total visible optical depth at 550 nm from either the Moderate resolution Imaging Spectroradiometer (MODIS/Aqua or Terra, or the Multi-angle Imaging SpectroRadiometer (MISR, or the Polarization and Anisotropy of Reflectances for Atmospheric Science coupled with Observations from a Lidar (PARASOL. Taking into account the ratio existing between infrared and visible AODs, the diversity between the different 550 nm AODs is similar to the difference between these and the IASI AODs. The infrared AOD to visible AOD ratio, partly reflecting the varying distribution of the dust layer between the dust coarse mode particles seen by IASI, and the fine mode seen by the other instruments, is found to vary with the region observed with values close to already published values. Comparisons between the climatologies of the 10 μm IASI AOD and of the PARASOL non-spherical coarse mode AOD at 865 nm, both expected to be representative of the dust coarse mode, lead to conclusions differing according to the region considered. These differences are discussed in the light of the MODIS Angström exponent (865–550 nm. At local scale, around six Aerosol Robotic Network (AERONET sites, close or far from the dust sources, a similar satisfactory agreement is found between IASI and the visible AODs and the differences between these products are

  4. A browser-based 3D Visualization Tool designed for comparing CERES/CALIOP/CloudSAT level-2 data sets.

    Science.gov (United States)

    Chu, C.; Sun-Mack, S.; Chen, Y.; Heckert, E.; Doelling, D. R.

    2017-12-01

    In Langley NASA, Clouds and the Earth's Radiant Energy System (CERES) and Moderate Resolution Imaging Spectroradiometer (MODIS) are merged with Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and CloudSat Cloud Profiling Radar (CPR). The CERES merged product (C3M) matches up to three CALIPSO footprints with each MODIS pixel along its ground track. It then assigns the nearest CloudSat footprint to each of those MODIS pixels. The cloud properties from MODIS, retrieved using the CERES algorithms, are included in C3M with the matched CALIPSO and CloudSat products along with radiances from 18 MODIS channels. The dataset is used to validate the CERES retrieved MODIS cloud properties and the computed TOA and surface flux difference using MODIS or CALIOP/CloudSAT retrieved clouds. This information is then used to tune the computed fluxes to match the CERES observed TOA flux. A visualization tool will be invaluable to determine the cause of these large cloud and flux differences in order to improve the methodology. This effort is part of larger effort to allow users to order the CERES C3M product sub-setted by time and parameter as well as the previously mentioned visualization capabilities. This presentation will show a new graphical 3D-interface, 3D-CERESVis, that allows users to view both passive remote sensing satellites (MODIS and CERES) and active satellites (CALIPSO and CloudSat), such that the detailed vertical structures of cloud properties from CALIPSO and CloudSat are displayed side by side with horizontally retrieved cloud properties from MODIS and CERES. Similarly, the CERES computed profile fluxes whether using MODIS or CALIPSO and CloudSat clouds can also be compared. 3D-CERESVis is a browser-based visualization tool that makes uses of techniques such as multiple synchronized cursors, COLLADA format data and Cesium.

  5. Improving XCO2 Retrievals from OCO2 by using CALIOP-derived Aerosol Priors

    Science.gov (United States)

    Merrelli, A. J.; Bennartz, R.; O'Dell, C.

    2016-12-01

    Trace gas retrievals from reflected solar radiation spectra are particularly sensitive to the presence of clouds and aerosol particles that modify the optical path length of the incident and reflected sunlight. These particles can scatter radiation in complicated ways, and the resulting impact on the radiance spectra is dependent on the spatial distribution and single scattering properties. The information content in the radiance spectrum alone is not high enough to constrain these properties for the high accuracy needed for carbon dioxide retrieval. Retrieval biases due to improper placement or typing of the scatterers can be larger than the required retrieval precision. For the carbon dioxide retrieval from the NASA Orbiting Carbon Observatory-2 (OCO-2) mission, these biases are reduced by multiple methods, including data screening and selection algorithms, climatological aerosol priors, and post processing bias correction by comparison to independent column-averaged carbon dioxide (XCO2) measurements such as Total Carbon ColumnObserving Network (TCCON).We explore an additional method that uses independent a priori information on the scatterer vertical distribution directly in the sensor field of view. The independent aerosol constraint comes from actively sensed aerosol profiles from the CALIOP instrument. The two satellites (CALIPSO and OCO-2) are both members of the A-Train formation, and for the past year they have flown in a tighter formation within the A-Train that puts both instruments' fields of view to within 5 km when OCO-2 operates in nadir mode. We focus on data collection near TCCON sites to show the change in the satellite XCO2 versus an independent reference.

  6. Instrumentation

    International Nuclear Information System (INIS)

    Prieur, G.; Nadi, M.; Hedjiedj, A.; Weber, S.

    1995-01-01

    This second chapter on instrumentation gives little general consideration on history and classification of instrumentation, and two specific states of the art. The first one concerns NMR (block diagram of instrumentation chain with details on the magnets, gradients, probes, reception unit). The first one concerns precision instrumentation (optical fiber gyro-meter and scanning electron microscope), and its data processing tools (programmability, VXI standard and its history). The chapter ends with future trends on smart sensors and Field Emission Displays. (D.L.). Refs., figs

  7. Instrumentation

    International Nuclear Information System (INIS)

    Decreton, M.

    2001-01-01

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor

  8. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2001-04-01

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor.

  9. Reusing Joint Polar Satellite System (jpss) Ground System Components to Process AURA Ozone Monitoring Instrument (omi) Science Products

    Science.gov (United States)

    Moses, J. F.; Jain, P.; Johnson, J.; Doiron, J. A.

    2017-12-01

    New Earth observation instruments are planned to enable advancements in Earth science research over the next decade. Diversity of Earth observing instruments and their observing platforms will continue to increase as new instrument technologies emerge and are deployed as part of National programs such as Joint Polar Satellite System (JPSS), Geostationary Operational Environmental Satellite system (GOES), Landsat as well as the potential for many CubeSat and aircraft missions. The practical use and value of these observational data often extends well beyond their original purpose. The practicing community needs intuitive and standardized tools to enable quick unfettered development of tailored products for specific applications and decision support systems. However, the associated data processing system can take years to develop and requires inherent knowledge and the ability to integrate increasingly diverse data types from multiple sources. This paper describes the adaptation of a large-scale data processing system built for supporting JPSS algorithm calibration and validation (Cal/Val) node to a simplified science data system for rapid application. The new configurable data system reuses scalable JAVA technologies built for the JPSS Government Resource for Algorithm Verification, Independent Test, and Evaluation (GRAVITE) system to run within a laptop environment and support product generation and data processing of AURA Ozone Monitoring Instrument (OMI) science products. Of particular interest are the root requirements necessary for integrating experimental algorithms and Hierarchical Data Format (HDF) data access libraries into a science data production system. This study demonstrates the ability to reuse existing Ground System technologies to support future missions with minimal changes.

  10. Instrumentation

    International Nuclear Information System (INIS)

    Decreton, M.

    2002-01-01

    SCK-CEN's R and D programme on instrumentation involves the development of advanced instrumentation systems for nuclear applications as well as the assessment of the performance of these instruments in a radiation environment. Particular emphasis is on the use of optical fibres as umbilincal links of a remote handling unit for use during maintanance of a fusion reacor, studies on the radiation hardening of plasma diagnostic systems; investigations on new instrumentation for the future MYRRHA accelerator driven system; space applications related to radiation-hardened lenses; the development of new approaches for dose, temperature and strain measurements; the assessment of radiation-hardened sensors and motors for remote handling tasks and studies of dose measurement systems including the use of optical fibres. Progress and achievements in these areas for 2001 are described

  11. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    SCK-CEN's R and D programme on instrumentation involves the development of advanced instrumentation systems for nuclear applications as well as the assessment of the performance of these instruments in a radiation environment. Particular emphasis is on the use of optical fibres as umbilincal links of a remote handling unit for use during maintanance of a fusion reacor, studies on the radiation hardening of plasma diagnostic systems; investigations on new instrumentation for the future MYRRHA accelerator driven system; space applications related to radiation-hardened lenses; the development of new approaches for dose, temperature and strain measurements; the assessment of radiation-hardened sensors and motors for remote handling tasks and studies of dose measurement systems including the use of optical fibres. Progress and achievements in these areas for 2001 are described.

  12. Instrumentation

    International Nuclear Information System (INIS)

    Umminger, K.

    2008-01-01

    A proper measurement of the relevant single and two-phase flow parameters is the basis for the understanding of many complex thermal-hydraulic processes. Reliable instrumentation is therefore necessary for the interaction between analysis and experiment especially in the field of nuclear safety research where postulated accident scenarios have to be simulated in experimental facilities and predicted by complex computer code systems. The so-called conventional instrumentation for the measurement of e. g. pressures, temperatures, pressure differences and single phase flow velocities is still a solid basis for the investigation and interpretation of many phenomena and especially for the understanding of the overall system behavior. Measurement data from such instrumentation still serves in many cases as a database for thermal-hydraulic system codes. However some special instrumentation such as online concentration measurement for boric acid in the water phase or for non-condensibles in steam atmosphere as well as flow visualization techniques were further developed and successfully applied during the recent years. Concerning the modeling needs for advanced thermal-hydraulic codes, significant advances have been accomplished in the last few years in the local instrumentation technology for two-phase flow by the application of new sensor techniques, optical or beam methods and electronic technology. This paper will give insight into the current state of instrumentation technology for safety-related thermohydraulic experiments. Advantages and limitations of some measurement processes and systems will be indicated as well as trends and possibilities for further development. Aspects of instrumentation in operating reactors will also be mentioned.

  13. Development of the Next Generation of Seismological Instrumentation for Polar Environments

    Science.gov (United States)

    Winberry, J. P.; Anderson, K. R.; Huerta, A. D.; Bernsen, S. P.; Parker, T.; Carpenter, P.; Woodward, R.; Beaudoin, B. C.; Bilek, S. L.

    2014-12-01

    Ice covered regions comprise >10% of Earth's continental area; and include regions with poorly understood ice dynamics, ice shelf stability, hydrology, tectonic histories and basic geologic structure both deep and shallow. Scientific investigations of these regions are challenged by extreme weather, limited and expensive logistics, and the physical conditions of the ice environment. We report on the next development of a new NSF MRI-supported community seismic capability for studying ice-covered regions- the Geophysical Earth Observatory for Ice Covered Environments (GEOICE). This project is fundamentally motivated by the need to densify and optimize the collection of high-quality data relevant to key solid Earth and cryosphere science questions. The instrument capability will include a hybrid seismograph pool of broadband and intermediate elements, for observation of both long-period (e.g., long-period surface waves and slow sources) and intermediate-to-short-period (e.g., teleseismic body waves local seismicity, impulsive or extended glaciogenic signals). The GEOICE instrument, and its power and other ancillary systems, will be specifically designed to both withstand conditions associated with icy environments, including cold/wet conditions and high-latitude solar limitations, and to require minimal installation time and logistical load (i.e., size and weight), while maximizing ease-of-use in the field, in data handling, and in telemetry compatibility. Key features will include a design that integrates the seismometer and data logger into a single environmentally and mechanically robust housing, very low power requirements (peer-reviewed community use.

  14. Instruments

    Energy Technology Data Exchange (ETDEWEB)

    Buehrer, W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-12-31

    The present paper mediates a basic knowledge of the most commonly used experimental techniques. We discuss the principles and concepts necessary to understand what one is doing if one performs an experiment on a certain instrument. (author) 29 figs., 1 tab., refs.

  15. Biogeochemical fingerprints of life: earlier analogies with polar ecosystems suggest feasible instrumentation for probing the Galilean moons

    Science.gov (United States)

    Chela-Flores, J.; Cicuttin, A.; Crespo, M. L.; Tuniz, C.

    2015-07-01

    We base our search for the right instrumentation for detecting biosignatures on Europa on the analogy suggested by the recent work on polar ecosystems in the Canadian Arctic at Ellesmere Island. In that location sulphur patches (analogous to the Europan patches) are accumulating on glacial ice lying over saline springs rich in sulphate and sulphide. Their work reinforces earlier analogies in Antarctic ecosystems that are appropriate models for possible habitats that will be explored by the European Space Agency JUpiter ICy Moons Explorer (JUICE) mission to the Jovian System. Its Jupiter Ganymede Orbiter (JGO) will include orbits around Europa and Ganymede. The Galileo orbital mission discovered surficial patches of non-ice elements on Europa that were widespread and, in some cases possibly endogenous. This suggests the possibility that the observed chemical elements in the exoatmosphere may be from the subsurface ocean. Spatial resolution calculations of Cassidy and co-workers are available, suggesting that the atmospheric S content can be mapped by a neutral mass spectrometer, now included among the selected JUICE instruments. In some cases, large S-fractionations are due to microbial reduction and disproportionation (although sometimes providing a test for ecosystem fingerprints, even though with Sim - Bosak - Ono we maintain that microbial sulphate reduction large sulphur isotope fractionation does not require disproportionation. We address the question of the possible role of oxygen in the Europan ocean. Instrument issues are discussed for measuring stable S-isotope fractionations up to the known limits in natural populations of δ34 ~ -70‰. We state the hypothesis of a Europa anaerobic oceanic population of sulphate reducers and disproportionators that would have the effect of fractionating the sulphate that reaches the low-albedo surficial regions. This hypothesis is compatible with the time-honoured expectation of Kaplan and co-workers (going back to the

  16. Instrumentation

    International Nuclear Information System (INIS)

    Didierjean, B.; Jobez, J-P.; Seguinot, J.; Ypsilantis, T.

    1997-01-01

    A Hybrid Photon Detector (HPD) is currently manufactured in the framework of the tests of LHC-B collaboration. These extremely fast and sensible detectors (95% efficiency and 1 ns time accuracy for a single electron) could be utilized in many other applications: long base neutrino oscillations and possibly, HELLAZ. The model consists of an array of 2,048 1 x 1 mm 2 on Si strips of 50 mm thickness placed in glass cylinders of 127 mm diameter provided with Si windows and containing focalization electrodes. The electron circuits on 16 VA3 readout ceramic chips where designed, realized and tested. The stainless steel base card provided with 40 vacuum holes was already realised. The first production tests of visible light bi-alkali photocathodes operating in high vacuum will be performed soon. The design of the RICH2 counter (covering polar angles from 12 to 120 mrad) has been modified by turning the 120 mrad mirror to increase the spectrometer luminosity, i.e. to increase the length of the radiation path in gas by a factor of two. A second mirror sends the image in a region behind the magnetic field return, a region well-shielded from the LHC interaction zone. This design will provided 28 points for a β = 1 tracks and an angular uncertainty of 0.34 mrad per point. To cover the entire image 115 HPD will be necessary. The reconstruction of the complex systems of rings has been recently accomplished for events typical for RICH2, downstream, to discriminate between pions and kaons between 16 and 180 GeV/c. A simulation of 3,068 tracks has produced only 19 erroneous identifications, i.e. 0.6%. Another, simulation of 1,989 tracks with the RICH upstream resulted in 39 erroneous π/K identification, i.e. 2%. The report presents also the long base RICH experiment for detecting neutrino oscillations. A new version of 100 m length and 18.6 m diameter (27 kt of water) provided with HPDs of 250 mm diameter with 85 6 x 6 mm 2 arrays has been designed. Fifty such detectors will be

  17. Evaluation of the aerosol vertical distribution in global aerosol models through comparison against CALIOP measurements: AeroCom phase II results: AEROSOL PROFILES IN AEROCOM II GCM

    Energy Technology Data Exchange (ETDEWEB)

    Koffi, Brigitte [European Commission, Joint Research Centre, Institute for Environment and Sustainability, Ispra Italy; Schulz, Michael [Norwegian Meteorological Institute, Oslo Norway; Bréon, François-Marie [Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette France; Dentener, Frank [European Commission, Joint Research Centre, Institute for Environment and Sustainability, Ispra Italy; Steensen, Birthe Marie [Norwegian Meteorological Institute, Oslo Norway; Griesfeller, Jan [Norwegian Meteorological Institute, Oslo Norway; Winker, David [NASA Langley Research Center, MS/475, Hampton Virginia USA; Balkanski, Yves [Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette France; Bauer, Susanne E. [Center for Climate Systems Research, Columbia University, New York New York USA; NASA Goddard Institute for Space Studies, New York New York USA; Bellouin, Nicolas [Department of Meteorology, University of Reading, Reading UK; Berntsen, Terje [Department of Geosciences, University of Oslo, Oslo Norway; Center for International Climate and Environmental Research-Oslo (CICERO), Oslo Norway; Bian, Huisheng [NASA Goddard Space Flight Center, Greenbelt Maryland USA; Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore Country Maryland USA; Chin, Mian [NASA Goddard Space Flight Center, Greenbelt Maryland USA; Diehl, Thomas [European Commission, Joint Research Centre, Institute for Environment and Sustainability, Ispra Italy; Easter, Richard [Pacific Northwest National Laboratory, Richland Washington USA; Ghan, Steven [Pacific Northwest National Laboratory, Richland Washington USA; Hauglustaine, Didier A. [Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette France; Iversen, Trond [Norwegian Meteorological Institute, Oslo Norway; Department of Geosciences, University of Oslo, Oslo Norway; Kirkevåg, Alf [Norwegian Meteorological Institute, Oslo Norway; Liu, Xiaohong [Pacific Northwest National Laboratory, Richland Washington USA; Now at University of Wyoming, Laramie Wyoming USA; Lohmann, Ulrike [ETH-Zentrum, Zürich Switzerland; Myhre, Gunnar [Center for International Climate and Environmental Research-Oslo (CICERO), Oslo Norway; Rasch, Phil [NASA Goddard Space Flight Center, Greenbelt Maryland USA; Seland, Øyvind [Norwegian Meteorological Institute, Oslo Norway; Skeie, Ragnhild B. [Center for International Climate and Environmental Research-Oslo (CICERO), Oslo Norway; Steenrod, Stephen D. [NASA Goddard Space Flight Center, Greenbelt Maryland USA; Stier, Philip [Department of Physics, University of Oxford, Oxford UK; Tackett, Jason [Science Systems and Applications, Inc., Hampton Virginia USA; Takemura, Toshihiko [Research Institute for Applied Mechanics, Kyushu University, Fukuoka Japan; Tsigaridis, Kostas [Center for Climate Systems Research, Columbia University, New York New York USA; NASA Goddard Institute for Space Studies, New York New York USA; Vuolo, Maria Raffaella [Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette France; Now at National Institute for Agronomic Research, Thiverval-Grignon France; Yoon, Jinho [Pacific Northwest National Laboratory, Richland Washington USA; Now at Gwangju Institute of Science and Technology, Gwangju Korea; Zhang, Kai [Pacific Northwest National Laboratory, Richland Washington USA; Max Planck Institute for Meteorology, Hamburg Germany

    2016-06-27

    The ability of eleven models in simulating the aerosol vertical distribution from regional to global scales, as part of the second phase of the AeroCom model inter-comparison initiative (AeroCom II) is assessed and compared to results of the first phase. The evaluation is performed using a global monthly gridded dataset of aerosol extinction profiles built on purpose from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) Layer Product 3.01. Results over 12 sub-continental regions show that five models improved whereas three degraded in reproducing the Zα 0-6 km mean extinction height diagnostic, which is computed over the 0-6 km altitude range for each studied region and season. While the models’ performance remains highly variable, it has generally improved in terms of inter-regional diversity and seasonality. The biases in Zα 0-6 km have notably decreased in the U.S. and European industrial and downwind maritime regions, whereas the timing of the Zα 0-6 km peak season has improved for all but two models. However, most of the models now show a Zα 0-6 km underestimation over land, notably in the dust and biomass burning regions in Asia and Africa. At global scale, the AeroCom II models better reproduce the Zα 0-6 km latitudinal variability over ocean than over land. Hypotheses for the (changes in the) the performance of the individual models and for the inter-model diversity are discussed. We also provide an analysis of the CALIOP limitations and uncertainties that can contribute to the differences between the simulations and observations.

  18. Characterization of AVHRR global cloud detection sensitivity based on CALIPSO-CALIOP cloud optical thickness information: demonstration of results based on the CM SAF CLARA-A2 climate data record

    Science.gov (United States)

    Karlsson, Karl-Göran; Håkansson, Nina

    2018-02-01

    The sensitivity in detecting thin clouds of the cloud screening method being used in the CM SAF cloud, albedo and surface radiation data set from AVHRR data (CLARA-A2) cloud climate data record (CDR) has been evaluated using cloud information from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) onboard the CALIPSO satellite. The sensitivity, including its global variation, has been studied based on collocations of Advanced Very High Resolution Radiometer (AVHRR) and CALIOP measurements over a 10-year period (2006-2015). The cloud detection sensitivity has been defined as the minimum cloud optical thickness for which 50 % of clouds could be detected, with the global average sensitivity estimated to be 0.225. After using this value to reduce the CALIOP cloud mask (i.e. clouds with optical thickness below this threshold were interpreted as cloud-free cases), cloudiness results were found to be basically unbiased over most of the globe except over the polar regions where a considerable underestimation of cloudiness could be seen during the polar winter. The overall probability of detecting clouds in the polar winter could be as low as 50 % over the highest and coldest parts of Greenland and Antarctica, showing that a large fraction of optically thick clouds also remains undetected here. The study included an in-depth analysis of the probability of detecting a cloud as a function of the vertically integrated cloud optical thickness as well as of the cloud's geographical position. Best results were achieved over oceanic surfaces at mid- to high latitudes where at least 50 % of all clouds with an optical thickness down to a value of 0.075 were detected. Corresponding cloud detection sensitivities over land surfaces outside of the polar regions were generally larger than 0.2 with maximum values of approximately 0.5 over the Sahara and the Arabian Peninsula. For polar land surfaces the values were close to 1 or higher with maximum values of 4.5 for the parts

  19. Characterization of AVHRR global cloud detection sensitivity based on CALIPSO-CALIOP cloud optical thickness information: demonstration of results based on the CM SAF CLARA-A2 climate data record

    Directory of Open Access Journals (Sweden)

    K.-G. Karlsson

    2018-02-01

    Full Text Available The sensitivity in detecting thin clouds of the cloud screening method being used in the CM SAF cloud, albedo and surface radiation data set from AVHRR data (CLARA-A2 cloud climate data record (CDR has been evaluated using cloud information from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP onboard the CALIPSO satellite. The sensitivity, including its global variation, has been studied based on collocations of Advanced Very High Resolution Radiometer (AVHRR and CALIOP measurements over a 10-year period (2006–2015. The cloud detection sensitivity has been defined as the minimum cloud optical thickness for which 50 % of clouds could be detected, with the global average sensitivity estimated to be 0.225. After using this value to reduce the CALIOP cloud mask (i.e. clouds with optical thickness below this threshold were interpreted as cloud-free cases, cloudiness results were found to be basically unbiased over most of the globe except over the polar regions where a considerable underestimation of cloudiness could be seen during the polar winter. The overall probability of detecting clouds in the polar winter could be as low as 50 % over the highest and coldest parts of Greenland and Antarctica, showing that a large fraction of optically thick clouds also remains undetected here. The study included an in-depth analysis of the probability of detecting a cloud as a function of the vertically integrated cloud optical thickness as well as of the cloud's geographical position. Best results were achieved over oceanic surfaces at mid- to high latitudes where at least 50 % of all clouds with an optical thickness down to a value of 0.075 were detected. Corresponding cloud detection sensitivities over land surfaces outside of the polar regions were generally larger than 0.2 with maximum values of approximately 0.5 over the Sahara and the Arabian Peninsula. For polar land surfaces the values were close to 1 or higher with maximum values

  20. A method for determination of cirrus extinction-to-backscatter ratio from CALIOP data

    Directory of Open Access Journals (Sweden)

    Zhang Jingbin

    2016-01-01

    Full Text Available We are presenting an empirical equation to retrieve cirrus lidar ratio by using CALIOP 532 nm level 1 data for nighttime cases. Retrieval results have non-relationship with cirrus multiple scattering effects and not affected by the error of transmission. The average CALIPSO 532 nm cirrus lidar ratio over Longitude 120+/- 10 and Latitude 25+/-10 for whole year of 2008 are 21.66±0.06sr for the year of 2008 respectively, with the maximum bias of 9.25% for the year 2008, the results is fairly stable and reasonable.

  1. Global Aerosol Direct Radiative Effect From CALIOP and C3M

    Science.gov (United States)

    Winker, Dave; Kato, Seiji; Tackett, Jason

    2015-01-01

    Aerosols are responsible for the largest uncertainties in current estimates of climate forcing. These uncertainties are due in part to the limited abilities of passive sensors to retrieve aerosols in cloudy skies. We use a dataset which merges CALIOP observations together with other A-train observations to estimate aerosol radiative effects in cloudy skies as well as in cloud-free skies. The results can be used to quantify the reduction of aerosol radiative effects in cloudy skies relative to clear skies and to reduce current uncertainties in aerosol radiative effects.

  2. A study of polar ozone depletion based on sequential assimilation of satellite data from the ENVISAT/MIPAS and Odin/SMR instruments

    Directory of Open Access Journals (Sweden)

    J. D. Rösevall

    2007-01-01

    Full Text Available The objective of this study is to demonstrate how polar ozone depletion can be mapped and quantified by assimilating ozone data from satellites into the wind driven transport model DIAMOND, (Dynamical Isentropic Assimilation Model for OdiN Data. By assimilating a large set of satellite data into a transport model, ozone fields can be built up that are less noisy than the individual satellite ozone profiles. The transported fields can subsequently be compared to later sets of incoming satellite data so that the rates and geographical distribution of ozone depletion can be determined. By tracing the amounts of solar irradiation received by different air parcels in a transport model it is furthermore possible to study the photolytic reactions that destroy ozone. In this study, destruction of ozone that took place in the Antarctic winter of 2003 and in the Arctic winter of 2002/2003 have been examined by assimilating ozone data from the ENVISAT/MIPAS and Odin/SMR satellite-instruments. Large scale depletion of ozone was observed in the Antarctic polar vortex of 2003 when sunlight returned after the polar night. By mid October ENVISAT/MIPAS data indicate vortex ozone depletion in the ranges 80–100% and 70–90% on the 425 and 475 K potential temperature levels respectively while the Odin/SMR data indicates depletion in the ranges 70–90% and 50–70%. The discrepancy between the two instruments has been attributed to systematic errors in the Odin/SMR data. Assimilated fields of ENVISAT/MIPAS data indicate ozone depletion in the range 10–20% on the 475 K potential temperature level, (~19 km altitude, in the central regions of the 2002/2003 Arctic polar vortex. Assimilated fields of Odin/SMR data on the other hand indicate ozone depletion in the range 20–30%.

  3. LAP-ND: a new instrument for vector polarization analysis and neutron depolarization measurements at FRJ-2

    Energy Technology Data Exchange (ETDEWEB)

    Ioffe, Alexander; Bussmann, Klaus; Dohmen, Ludwig; Axelrod, Leonid; Gordeev, Gennadi; Brueckel, Thomas

    2004-07-15

    The method of vector analysis of the neutron polarization allows for the determination of both the magnitude and the direction of the magnetization vector in the sample. A directional distribution of the magnetization in a sample results in a spread of the direction of the polarization vector in space and thus in the depolarization of the incident beam. A new neutron depolarization set up is installed at the research reactor FRJ-2 of the Forschungszentrum Juelich. The main feature of the set up is the use of rather long wavelength, {lambda}=(4-6.5) A, neutrons thus allowing for a significant increase in the sensitivity of depolarization measurements. The set up uses a non-cryogenic zero-field sample chamber with the residual magnetic field of about 1 mG. It will be used for the determination of the sample magnetization at mesoscopic and macroscopic levels and for the study of magnetic phase transitions, magnetic nanostructures, magnetic glasses, etc.

  4. Instrumentation for cryogenic magic angle spinning dynamic nuclear polarization using 90L of liquid nitrogen per day.

    Science.gov (United States)

    Albert, Brice J; Pahng, Seong Ho; Alaniva, Nicholas; Sesti, Erika L; Rand, Peter W; Saliba, Edward P; Scott, Faith J; Choi, Eric J; Barnes, Alexander B

    2017-10-01

    Cryogenic sample temperatures can enhance NMR sensitivity by extending spin relaxation times to improve dynamic nuclear polarization (DNP) and by increasing Boltzmann spin polarization. We have developed an efficient heat exchanger with a liquid nitrogen consumption rate of only 90L per day to perform magic-angle spinning (MAS) DNP experiments below 85K. In this heat exchanger implementation, cold exhaust gas from the NMR probe is returned to the outer portion of a counterflow coil within an intermediate cooling stage to improve cooling efficiency of the spinning and variable temperature gases. The heat exchange within the counterflow coil is calculated with computational fluid dynamics to optimize the heat transfer. Experimental results using the novel counterflow heat exchanger demonstrate MAS DNP signal enhancements of 328±3 at 81±2K, and 276±4 at 105±2K. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. The polarization modulators based on liquid crystal variable retarders for the PHI and METIS instruments for the solar orbiter mission

    Science.gov (United States)

    Alvarez-Herrero, A.; García Parejo, P.; Laguna, H.; Villanueva, J.; Barandiarán, J.; Bastide, L.; Reina, M.; Royo, M.

    2017-11-01

    A technical development activity was carried out from 2009 to 2011 under ESA supervision to validate the Liquid Crystal Variable Retarders (LCVRs) as polarization modulators for the Solar Orbiter mission. After this, the technology achieved the Technology Readiness Level 5 (TRL5) corresponding to "Component Validation in Relevant Environment". Afterwards, additional tests and characterizations were performed in order to select the final specifications of the LCVRs cells to optimize their performances under the mission environmental conditions. The LCVRs will be used to measure the complete Stokes vector of the incoming light in PHI (The Polarimetric and Helioseismic Imager for Solar Orbiter) and the linear polarization in the case of METIS (Multi Element Telescope for Imaging and Spectroscopy). PHI is an imaging spectro-polarimeter that will acquire high resolution solar magnetograms. On the other hand, METIS is a solar coronagraph that will analyze the linear polarization for observations of the visible-light K-corona. The polarization modulators are described in this work including the optical, mechanical, thermal and electrical aspects. Both modulators will consist of two identical LCVRs with a relative azimuth orientation of 45° for PHI and parallel for the METIS modulator. In the first case, the configuration allows the analysis of the full Stockes vector with maximum polarimetric efficiencies. In the second setup, wide acceptance angles (stress produced by the mounts to the cells, but taking into account the vibration environment due to the launch loads that the device shall withstand. Additionally, the optical clear aperture has been maximized and the design avoids breaks due to thermo-elastic deformations produced during the thermal cycling. Finally, the electrical cables and connections have been designed to obtain a very compact, modular and robust device.

  6. Aerosol Indirect Effect on Warm Clouds over Eastern China Using Combined CALIOP and MODIS Observations

    Science.gov (United States)

    Guo, Jianping; Wang, Fu; Huang, Jingfeng; Li, Xiaowen

    2015-04-01

    Aerosol, one of key components of the climate system, is highly variable, both temporally and spatially. It often exerts great influences on the cloud-precipitation chain processes by serving as CCN/IN, altering cloud microphysics and its life cycle. Yet, the aerosol indirect effect on clouds remains largely unknown, because the initial changes in clouds due to aerosols may be enhanced or dampened by such feedback processes as modified cloud dynamics, or evaporation of the smaller droplets due to the competition for water vapor. In this study, we attempted to quantify the aerosol effects on warm cloud over eastern China, based on near-simultaneous retrievals from MODIS/AQUA, CALIOP/CALIPSO and CPR/CLOUDSAT during the period 2006 to 2010. The seasonality of aerosol from ground-based PM10 is quite different from that estimated from MODIS AOD. This result is corroborated by lower level profile of aerosol occurrence frequency from CALIOP, indicating the significant role CALIOP could play in aerosol-cloud interaction. The combined use of CALIOP and CPR facilitate the process to exactly determine the (vertical) position of warm cloud relative to aerosol, out of six scenarios in terms of aerosol-cloud mixing status in terms of aerosol-cloud mixing status, which shows as follows: AO (Aerosol only), CO (Cloud only), SASC (Single aerosol-single cloud), SADC (single aerosol-double cloud), DASC (double aerosol-single cloud), and others. Results shows that about 54% of all the cases belong to mixed status, among all the collocated aerosol-cloud cases. Under mixed condition, a boomerang shape is observed, i.e., reduced cloud droplet radius (CDR) is associated with increasing aerosol at moderate aerosol pollution (AODthe boomerang shape varies with season. For moderate aerosol loading (AODthe effect on the droplet size for the "Mixed" cases is greater during cold season (denoted by a large slope), as compared with that during warm season. It is likely associated with an increase

  7. Some Technical Aspects of a CALIOP and MODIS Data Analysis that Examines Near-Cloud Aerosol Properties as a Function of Cloud Fraction

    Science.gov (United States)

    Varnai, Tamas; Yang, Weidong; Marshak, Alexander

    2016-01-01

    CALIOP shows stronger near-cloud changes in aerosol properties at higher cloud fractions. Cloud fraction variations explain a third of near-cloud changes in overall aerosol statistics. Cloud fraction and aerosol particle size distribution have a complex relationship.

  8. CALIOP: a multichannel design code for gas-cooled fast reactors. Code description and user's guide

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, W.I.

    1980-10-01

    CALIOP is a design code for fluid-cooled reactors composed of parallel fuel tubes in hexagonal or cylindrical ducts. It may be used with gaseous or liquid coolants. It has been used chiefly for design of a helium-cooled fast breeder reactor and has built-in cross section information to permit calculations of fuel loading, breeding ratio, and doubling time. Optional cross-section input allows the code to be used with moderated cores and with other fuels.

  9. Polar ionic conductivity profile in fair weather conditions. Terrestrial test of the Huygens/Hasi-PWA instrument aboard the Comas Sola balloon

    Science.gov (United States)

    López-Moreno, J. J.; Molina-Cuberos, G. J.; Rodrigo, R.; Hamelin, M.; Schwingenschuh, K.

    2001-12-01

    The permittivity wave and altimetry (PWA) instrument is a part of the CASSINI/HUYGENS HASI experiment and was designed to determine the electrical parameters of the atmosphere of Titan in 2004. In December 1995, a balloon campaign was conducted in León, Spain, to test the HASI onboard hardware and software using a HUYGENS probe mock-up in an electromagnetic-disturbance-free environment (mainly from power emission lines at 50Hz). This work is concerned with the measurements of small ion polar conductivities and DC fields using the PWA relaxation probes (RP). The two RP electrodes were periodically set to +/-5V relative to the conductive surface of the mock-up and allowed to discharge in the surrounding atmosphere. The polar components of conductivity are calculated from the discharge time, and the DC field from the floating potential differences once the electrodes reach equilibrium. In spite of some observed effects, such as mock-up charging or oscillations in the measurement of potential, the conductivity measurements are coherent and in good agreement with the obtained results in other experiments. The conductivity data were collected in `fair-weather' conditions, up to 30km during a 4-h flight, every 72s, giving an altitude resolution better than 400m. We also discuss the DC field data that do not lead, in presence of charging effects, to a straightforward measurement of the natural DC field. The Comas Solá balloon flight, first real test of the PWA experiment in the terrestrial atmosphere, confirmed the validity of the ionic conductivity measurements but raised the problem of a reliable interpretation of the DC field.

  10. MODIS Collection 6 shortwave-derived cloud phase classification algorithm and comparisons with CALIOP

    Science.gov (United States)

    Marchant, Benjamin; Platnick, Steven; Meyer, Kerry; Arnold, G. Thomas; Riedi, Jérôme

    2016-04-01

    Cloud thermodynamic phase (ice, liquid, undetermined) classification is an important first step for cloud retrievals from passive sensors such as MODIS (Moderate Resolution Imaging Spectroradiometer). Because ice and liquid phase clouds have very different scattering and absorbing properties, an incorrect cloud phase decision can lead to substantial errors in the cloud optical and microphysical property products such as cloud optical thickness or effective particle radius. Furthermore, it is well established that ice and liquid clouds have different impacts on the Earth's energy budget and hydrological cycle, thus accurately monitoring the spatial and temporal distribution of these clouds is of continued importance. For MODIS Collection 6 (C6), the shortwave-derived cloud thermodynamic phase algorithm used by the optical and microphysical property retrievals has been completely rewritten to improve the phase discrimination skill for a variety of cloudy scenes (e.g., thin/thick clouds, over ocean/land/desert/snow/ice surface, etc). To evaluate the performance of the C6 cloud phase algorithm, extensive granule-level and global comparisons have been conducted against the heritage C5 algorithm and CALIOP. A wholesale improvement is seen for C6 compared to C5.

  11. MODIS Collection 6 Shortwave-Derived Cloud Phase Discrimination Algorithm and comparisons with CALIOP and POLDER

    Science.gov (United States)

    Marchant, B.; Platnick, S. E.; Arnold, T.; Meyer, K.; Riedi, J.

    2014-12-01

    Cloud thermodynamic phase (ice or liquid) discrimination is an important first step for cloud retrievals from passive sensors such as MODIS (Moderate-Resolution Imaging Spectroradiometer). Because ice and liquid phase clouds have very different scattering and absorbing properties, an incorrect cloud phase decision can lead to substantial uncertainties in the cloud optical and microphysical property products such as cloud optical thickness or effective particle radius. Furthermore, it is well-established that ice and liquid clouds have different impacts on the Earth's energy budget and hydrological cycle, thus accurately monitoring the spatial and temporal distribution of these clouds is of continued importance. For MODIS Collection 6 (C6), the shortwave-derived cloud thermodynamic phase algorithm used by the optical and microphysical property retrievals has been completely rewritten to improve the phase discrimination skill for a variety of cloudy scenes (e.g., thin/thick clouds, over ocean/land/desert/snow/ice surface, etc). To evaluate the performance of the C6 cloud phase algorithm, extensive granule-level and global comparisons have been conducted against the heritage C5 algorithm, CALIOP, and POLDER. A wholesale improvement is seen for C6 compared to C5. We will present an overview of the MODIS C6 cloud phase algorithm updates and their impacts on cloud retrieval statistics, as well as ongoing efforts to continue algorithm improvement.

  12. Evaluation of Systematic Effects and Data Acquisition System for CALIOPE, an Experimental Search for CP Violation in ortho-Positronium Decays

    Science.gov (United States)

    Bartram, Chelsea; Henning, Reyco; Othman, Gulden; Murphy, Jake

    2016-09-01

    CALIOPE, or CP Aberrant Leptons in o-Ps Experiment, will search for CP -violating angular correlations between gamma rays in the decay of positronium. CALIOPE uses a tagged source inserted between two disks of aerogel centered in an annular array of 24 sodium iodide bars. We present an in-depth study of the systematics as well as developments on the DAQ. Specifically, we will discuss the implications of the results from our detailed Monte Carlo simulation as well as the outcomes of several toy Monte Carlo models. We will also present the DAQ design and results from early tests to characterize the position and energy reconstruction of the array.

  13. Demonstration That Calibration of the Instrument Response to Polarizations Parallel and Perpendicular to the Object Space Projected Slit of an Imaging Spectrometer Enable Measurement of the Atmospheric Absorption Spectrum in Region of the Weak CO2 Band for the Case of Arbitrary Polarization: Implication for the Geocarb Mission

    Science.gov (United States)

    Kumer, J. B.; Rairden, R. L.; Polonsky, I. N.; O'Brien, D. M.

    2014-12-01

    The Tropospheric Infrared Mapping Spectrometer (TIMS) unit rebuilt to operate in a narrow spectral region, approximately 1603 to 1615 nm, of the weak CO2 band as described by Kumer et al. (2013, Proc. SPIE 8867, doi:10.1117/12.2022668) was used to conduct the demonstration. An integrating sphere (IS), linear polarizers and quarter wave plate were used to confirm that the instrument's spectral response to unpolarized light, to 45° linearly polarized light and to circular polarized light are identical. In all these cases the intensity components Ip = Is where Ip is the component parallel to the object space projected slit and Is is perpendicular to the slit. In the circular polarized case Ip = Is in the time averaged sense. The polarizer and IS were used to characterize the ratio Rθ of the instrument response to linearly polarized light at the angle θ relative to parallel from the slit, for increments of θ from 0 to 90°, to that of the unpolarized case. Spectra of diffusely reflected sunlight passed through the polarizer in increments of θ, and divided by the respective Rθ showed identical results, within the noise limit, for solar spectrum multiplied by the atmospheric transmission and convolved by the Instrument Line Shape (ILS). These measurements demonstrate that unknown polarization in the diffusely reflected sunlight on this small spectral range affect only the slow change across the narrow band in spectral response relative to that of unpolarized light and NOT the finely structured / high contrast spectral structure of the CO2 atmospheric absorption that is used to retrieve the atmospheric content of CO2. The latter is one of the geoCARB mission objectives (Kumer et al, 2013). The situation is similar for the other three narrow geoCARB bands; O2 A band 757.9 to 768.6 nm; strong CO2 band 2045.0 to 2085.0 nm; CH4 and CO region 2300.6 to 2345.6 nm. Polonsky et al have repeated the mission simulation study doi:10.5194/amt-7-959-2014 assuming no use of a geo

  14. Inter-comparison between Hermesv2.0 and TNO-MAC-II emission data using the Caliope air quality system (Spain)

    NARCIS (Netherlands)

    Guevara, M.; Pay, M.T.; Martinez, F.; Soret, A.; Denier van der Gon, H.A.C.; Baldasano, J.M.

    2014-01-01

    This work examines and compares the performance of two emission datasets on modelling air quality concentrations for Spain: (i) the High-Elective Resolution Modelling Emissions System (HERMESv2.0) and (ii) the TNO-MACC-II emission inventory. For this purpose, the air quality system CALIOPE-AQFS

  15. Airborne Laser Polarization Sensor

    Science.gov (United States)

    Kalshoven, James, Jr.; Dabney, Philip

    1991-01-01

    Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

  16. Polarization Optics

    OpenAIRE

    Fressengeas, Nicolas

    2010-01-01

    The physics of polarization optics *Polarized light propagation *Partially polarized light; DEA; After a brief introduction to polarization optics, this lecture reviews the basic formalisms for dealing with it: Jones Calculus for totally polarized light and Stokes parameters associated to Mueller Calculus for partially polarized light.

  17. OSIRIS (Observing System Including PolaRisation in the Solar Infrared Spectrum) instrument: a multi-directional, polarized radiometer in the visible and shortwave infrared, airborne prototype of 3MI / EPS-SG Eumetsat - ESA mission

    Science.gov (United States)

    Matar, C.; Auriol, F.; Nicolas, J. M.; Parol, F.; Riedi, J.; Djellali, M. S.; Cornet, C.; Waquet, F.; Catalfamo, M.; Delegove, C.; Loisil, R.

    2017-12-01

    OSIRIS instrument largely inherits from the POLDER concept developed and operated between 1991 (first airborne prototype) and 2013 (end of the POLDER-3/PARASOL space-borne mission). It consists in two optical systems, one covering the visible to near infrared range (440, 490, 670, 763, 765, 870, 910 and 940 nm) and a second one for the shortwave infrared (940, 1020, 1240, 1360, 1620 and 2200 nm). Each optical system is composed of a wide field-of-view optics (114° and 105° respectively) associated to two rotating wheels with interferential filters (spectral) and analyzers filters (polarization) respectively, and a 2D array of detectors. For each channel, radiance is measured once without analyzer, followed by sequential measurements with the three analyzers shifted by an angle of 60° to reconstruct the total and polarized radiances. The complete acquisition sequence for all spectral channels last a couple of seconds according to the chosen measurement protocol. Thanks to the large field of view of the optics, any target is seen under several viewing angles during the aircraft motion. In a first step we will present the new ground characterization of the instrument based on laboratory measurements (linearity, flat-field, absolute calibration, induced polarization, polarizers efficiency and position), the radiometric model and the Radiometric Inverted Model (RIM) used to develop the Level 1 processing chain that is used to produce level 1 products (normalized radiances, polarized or not, with viewing geometries) from the instrument generated level 0 files (Digital Counts) and attitude information from inertial system. The stray light issues will be specifically discussed. In a second step we will present in-flight radiometric and geometric methods applied to OSIRIS data in order to control and validate ground-based calibrated products: molecular scattering method and sun-glint cross-band method for radiometric calibration, glories, rainbows and sun-glint targets

  18. Applications of pulsed nuclear magnetic resonance to chemistry: multiple-pulse NMR, cross polarization, magic-angle spinning annd instrumental design

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, P.D.

    1979-07-01

    Pulsed Nuclear Magnetic Resonance (NMR) has been applied to: (1) Measurements of the prinicpal components of the proton shielding tensors of the hydrides of zirconium chloride and zirconium bromide. Multiple-Pulse techniques have been used to remove static homonuclear dipolar coupling. The anisotropies and isotropic shifts of these tensors have been used to infer the possible locations of the hydrogen within the sandwich-like layers of these unusual compounds. (2) Studies of the oscillatory transfer of magnetic polarization between /sup 1/H and /sup 29/Si in substituted silanes. The technique of J Cross Polarization has been used to enhance sensitivity. The /sup 29/Si NMR shifts of -Si-O- model compounds have been investigated as a possible probe for future studies of the environment of bound oxygen in coal-derived liquids. (3) Measurements of the aromatic fraction of /sup 13/C in whole coals. The techniques of /sup 1/H-/sup 13/C Cross Polarization and Magic-Angle Spinning have been used to enhance sensitivity and remove shift anisotropy. Additional topics described are: (4) Calculation and properties of the broadened lineshape of the shileding Powder Pattern. (5) Calculation of the oscillatory transfer of magnetic polarization for an I-S system. (6) Numerical convolution and its uses. (7) The technique of digital filtering applied in the frequency domain. (8) The designs and properties of four NMR probe-circuits. (9) The design of a single-coil double-resonance probe for combined Magic-Angle Spinning and Cross Polarization. (10) The designs of low Q and high Q rf power amplifiers with emphasis on the rf matching circuitry.

  19. [Review] Polarization and Polarimetry

    Science.gov (United States)

    Trippe, Sascha

    2014-02-01

    Polarization is a basic property of light and is fundamentally linked to the internal geometry of a source of radiation. Polarimetry complements photometric, spectroscopic, and imaging analyses of sources of radiation and has made possible multiple astrophysical discoveries. In this article I review (i) the physical basics of polarization: electromagnetic waves, photons, and parameterizations; (ii) astrophysical sources of polarization: scattering, synchrotron radiation, active media, and the Zeeman, Goldreich-Kylafis, and Hanle effects, as well as interactions between polarization and matter (like birefringence, Faraday rotation, or the Chandrasekhar-Fermi effect); (iii) observational methodology: on-sky geometry, influence of atmosphere and instrumental polarization, polarization statistics, and observational techniques for radio, optical, and X/γ wavelengths; and (iv) science cases for astronomical polarimetry: solar and stellar physics, planetary system bodies, interstellar matter, astrobiology, astronomical masers, pulsars, galactic magnetic fields, gamma-ray bursts, active galactic nuclei, and cosmic microwave background radiation.

  20. Modeling of 2008 Kasatochi Volcanic Sulfate Direct Radiative Forcing: Assimilation of OMI SO2 Plume Height Data and Comparison with MODIS and CALIOP Observations

    Science.gov (United States)

    Wang, J.; Park, S.; Zeng, J.; Ge, C.; Yang, K.; Carn, S.; Krotkov, N.; Omar, A. H.

    2013-01-01

    Volcanic SO2 column amount and injection height retrieved from the Ozone Monitoring Instrument (OMI) with the Extended Iterative Spectral Fitting (EISF) technique are used to initialize a global chemistry transport model (GEOS-Chem) to simulate the atmospheric transport and lifecycle of volcanic SO2 and sulfate aerosol from the 2008 Kasatochi eruption, and to subsequently estimate the direct shortwave, top-of-the-atmosphere radiative forcing of the volcanic sulfate aerosol. Analysis shows that the integrated use of OMI SO2 plume height in GEOS-Chem yields: (a) good agreement of the temporal evolution of 3-D volcanic sulfate distributions between model simulations and satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar with Orthogonal Polarisation (CALIOP), and (b) an e-folding time for volcanic SO2 that is consistent with OMI measurements, reflecting SO2 oxidation in the upper troposphere and stratosphere is reliably represented in the model. However, a consistent (approx. 25 %) low bias is found in the GEOS-Chem simulated SO2 burden, and is likely due to a high (approx.20 %) bias of cloud liquid water amount (as compared to the MODIS cloud product) and the resultant stronger SO2 oxidation in the GEOS meteorological data during the first week after eruption when part of SO2 underwent aqueous-phase oxidation in clouds. Radiative transfer calculations show that the forcing by Kasatochi volcanic sulfate aerosol becomes negligible 6 months after the eruption, but its global average over the first month is -1.3W/sq m, with the majority of the forcing-influenced region located north of 20degN, and with daily peak values up to -2W/sq m on days 16-17. Sensitivity experiments show that every 2 km decrease of SO2 injection height in the GEOS-Chem simulations will result in a approx.25% decrease in volcanic sulfate forcing; similar sensitivity but opposite sign also holds for a 0.03 m increase of geometric radius of

  1. Air quality over Europe and Iberian Peninsula for 2004 at high horizontal resolution: evaluation of the CALIOPE modelling system

    Science.gov (United States)

    Jorba, O.; Piot, M.; Pay, M. T.; Jiménez-Guerrero, P.; López, E.; Pérez, C.; Gassó, S.; Baldasano, J. M.

    2009-09-01

    In the frame of the CALIOPE project (Baldasano et al., 2008a), a high-resolution air quality forecasting system, WRF-ARW/HERMES/CMAQ/DREAM, is under development and applied to the European domain (12km x 12km, 1hr) as well as to the Iberian Peninsula domain (4km x 4km, 1hr) to provide air quality forecasts for Spain (http://www.bsc.es/caliope/). The simulation of such high-resolution model system is possible by its implementation on the MareNostrum supercomputer. To reassure potential users and reduce uncertainties, the model system must be evaluated to assess its performances in terms of air quality levels and dynamics reproducibility. The present contribution describes a thorough quantitative evaluation study performed for a reference year (2004). CALIOPE is a complex system that integrates a variety of environmental models. WRF-ARW provides high-resolution meteorological fields to the system. It is configured with 38 vertical layers reaching up to 50 hPa. Meteorological initial and boundary conditions are obtained from the NCEP final analysis data. The HERMES emission model (Baldasano et al., 2008b) computes the emissions for the Iberian Peninsula simulation at 4 km horizontal resolution every hour using a bottom-up approach. For the European domain, HERMES disaggregates the EMEP expert emission inventory for 2004. The CMAQ chemical transport model solves the physico-chemical processes in the system. The vertical resolution of CMAQ for gas-phase and aerosols has been increased from 8 to 15 layers in order to simulate vertical exchanges more accurately. Chemical boundary conditions are provided by the LMDz-INCA2 global climate-chemistry model (see Hauglustaine et al., 2004). Finally, the DREAM model simulates long-range transport of mineral dust over the domains under study. In order to evaluate the performances of the CALIOPE system, model simulations were compared with ground-based measurements from the EMEP and Spanish air quality networks. For the European

  2. A 3-D evaluation of the MACC reanalysis dust product over the greater European region using CALIOP/CALIPSO satellite observations

    Science.gov (United States)

    Georgoulias, Aristeidis K.; Tsikerdekis, Athanasios; Amiridis, Vassilis; Marinou, Eleni; Benedetti, Angela; Zanis, Prodromos; Kourtidis, Konstantinos

    2016-04-01

    Significant amounts of dust are being transferred on an annual basis over the Mediterranean Basin and continental Europe from Northern Africa (Sahara Desert) and Middle East (Arabian Peninsula) as well as from other local sources. Dust affects a number of processes in the atmosphere modulating weather and climate also having an impact on human health and the economy. Therefore, the ability of simulating adequately the amount and optical properties of dust is essential. This work focuses on the evaluation of the MACC reanalysis dust product over the regions mentioned above. The evaluation procedure is based on pure dust satellite retrievals from CALIOP/CALIPSO that cover the period 2007-2012. The CALIOP/CALIPSO data utilized here come from an optimized retrieval scheme that was originally developed within the framework of the LIVAS (Lidar Climatology of Vertical Aerosol Structure for Space-Based LIDAR Simulation Studies) project. CALIOP/CALIPSO dust extinction coefficients and dust optical depth patterns at 532 nm are used for the validation of MACC natural aerosol extinction coefficients and dust optical depth patterns at 550 nm. Overall, it is shown in this work that space-based lidars may play a major role in the improvement of the MACC aerosol product. This research has been financed under the FP7 Programme MarcoPolo (Grand Number 606953, Theme SPA.2013.3.2-01).

  3. Hsp Polarization Verification

    Science.gov (United States)

    Bless, Robert

    1991-07-01

    This proposal defines the procedure for determining the instrumental polarization of the polarimetric IDT (IDT#1, POL) on the HSP. 1 of 2 unpolarized standard stars wil be observed using various filter-polarizer combinations. These observations will permit the instrumental polarization to be calibrated. The instrumental polarization must be determined to a high precision in order to vectoriallly remove it from HSP polarization observations to determine the actual astronomical polarization. Final run of proposal will look at one of 2 possible stars previously observed to get another look at the throughput. Revision History: Mark H. Slovak 8/30/88 Translated to V2 proposal instructions (RPSS V6.2) S. Laurent 1/20/89 Updated: Sally Laurent 2/24/89, 3/20/89, 4/13/89, 5/12/89 Modified: P. Stanley 1/15/90 - change to use CTA selected targets only; Fixes for aberration problem - SALM 7/30/90; Based on SV/HSP 1386. New submission changed targets and revised scheduling strategy. Revised: 26 Aug 92 J. Dolan, L. Walter, P. Reppert want to re-run the proposal (3985) one last time to bring down errors.

  4. NMR dispersion measurement of dynamic nuclear polarization

    International Nuclear Information System (INIS)

    Davies, K.; Cox, S.F.J.

    1978-01-01

    The feasibility of monitoring dynamic nuclear polarization from the NMR dispersive susceptibility is examined. Two prototype instruments are tested in a polarized proton target using organic target material. The more promising employs a tunnel diode oscillator, inside the target cavity, and should provide a precise polarization measurement working at a frequency far enough from the main resonance for the disturbance of the measured polarization to be negligible. Other existing methods for measuring target polarization are briefly reviewed. (author)

  5. Time Domain Induced Polarization

    DEFF Research Database (Denmark)

    Fiandaca, Gianluca; Auken, Esben; Christiansen, Anders Vest

    2012-01-01

    Time-domain-induced polarization has significantly broadened its field of reference during the last decade, from mineral exploration to environmental geophysics, e.g., for clay and peat identification and landfill characterization. Though, insufficient modeling tools have hitherto limited the use...... of time-domaininduced polarization for wider purposes. For these reasons, a new forward code and inversion algorithm have been developed using the full-time decay of the induced polarization response, together with an accurate description of the transmitter waveform and of the receiver transfer function......%. Furthermore, the presence of low-pass filters in time-domain-induced polarization instruments affects the early times of the acquired decays (typically up to 100 ms) and has to be modeled in the forward response to avoid significant loss of resolution. The developed forward code has been implemented in a 1D...

  6. Spatial distribution analysis of the OMI aerosol layer height: a pixel-by-pixel comparison to CALIOP observations

    Science.gov (United States)

    Chimot, Julien; Pepijn Veefkind, J.; Vlemmix, Tim; Levelt, Pieternel F.

    2018-04-01

    A global picture of atmospheric aerosol vertical distribution with a high temporal resolution is of key importance not only for climate, cloud formation, and air quality research studies but also for correcting scattered radiation induced by aerosols in absorbing trace gas retrievals from passive satellite sensors. Aerosol layer height (ALH) was retrieved from the OMI 477 nm O2 - O2 band and its spatial pattern evaluated over selected cloud-free scenes. Such retrievals benefit from a synergy with MODIS data to provide complementary information on aerosols and cloudy pixels. We used a neural network approach previously trained and developed. Comparison with CALIOP aerosol level 2 products over urban and industrial pollution in eastern China shows consistent spatial patterns with an uncertainty in the range of 462-648 m. In addition, we show the possibility to determine the height of thick aerosol layers released by intensive biomass burning events in South America and Russia from OMI visible measurements. A Saharan dust outbreak over sea is finally discussed. Complementary detailed analyses show that the assumed aerosol properties in the forward modelling are the key factors affecting the accuracy of the results, together with potential cloud residuals in the observation pixels. Furthermore, we demonstrate that the physical meaning of the retrieved ALH scalar corresponds to the weighted average of the vertical aerosol extinction profile. These encouraging findings strongly suggest the potential of the OMI ALH product, and in more general the use of the 477 nm O2 - O2 band from present and future similar satellite sensors, for climate studies as well as for future aerosol correction in air quality trace gas retrievals.

  7. Aerosol Optical Depth over Europe: Evaluation of the CALIOPE air quality modelling system with direct-sun AERONET observations

    Science.gov (United States)

    Basart, Sara; Pay, María. Teresa; Pérez, Carlos; Cuevas, Emilio; Jorba, Oriol; Piot, Matthias; María Baldasano, Jose

    2010-05-01

    In the frame of the CALIOPE project (Baldasano et al., 2008), the Barcelona Supercomputing Center (BSC-CNS) currently operates a high-resolution air quality forecasting system based on daily photochemical forecasts in Europe (12km x 12km resolution) with the WRF-ARW/HERMES/CMAQ modelling system (http://www.bsc.es/caliope) and desert dust forecasts over Southern Europe with BSC-DREAM8b (Pérez et al., 2006; http://www.bsc.es/projects/earthscience/DREAM). High resolution simulations and forecasts are possible through their implementation on MareNostrum supercomputer at BSC-CNS. As shown in previous air quality studies (e.g. Rodríguez et al., 2001; Jiménez-Guerrero et al., 2008), the contribution of desert dust on particulate matter levels in Southern Europe is remarkable due to its proximity to African desert dust sources. When considering only anthropogenic emissions (Baldasano et al., 2008) and the current knowledge about aerosol physics and chemistry, chemistry-transport model simulations underestimate the PM10 concentrations by 30-50%. As a first approach, the natural dust contribution from BSC-DREAM8b is on-line added to the anthropogenic aerosol output of CMAQ. The aim of the present work is the quantitative evaluation of the WRF-ARW/HERMES/ CMAQ/BSC-DREAM8b forecast system to simulate the Aerosol Optical Depth (AOD) over Europe. The performance of the modelled AOD has been quantitatively evaluated with discrete and categorical (skill scores) statistics by a comparison to direct-sun AERONET observations for 2004. The contribution of different types of aerosols will be analyzed by means of the O'Neill fine mode AOD products (O'Neill et al., 2001). A previous aerosol characterization of AERONET data was performed (Basart et al., 2009) in order to discriminate the different aerosol source contributions within the study region. The results indicate a remarkable improvement in the discrete and skill-scores evaluation (accuracy, critical success index and

  8. Primordial Inflation Polarization Explorer: Status and Plans

    Science.gov (United States)

    Kogut, Alan

    2009-01-01

    The Primordial Inflation Polarization Explorer is a balloon-borne instrument to measure the polarization of the cosmic microwave background in order to detect the characteristic signature of gravity waves created during an inflationary epoch in the early universe. PIPER combines cold /I.G K\\ optics, 5120 bolometric detectors, and rapid polarization modulation using VPM grids to achieve both high sensitivity and excellent control of systematic errors. I will discuss the current status and plans for the PIPER instrument.

  9. Caliope: an operational air quality forecasting system for the Iberian Peninsula, Balearic Islands and Canary Islands - first annual evaluation and ongoing developments

    Science.gov (United States)

    Baldasano, J. M.; Jiménez-Guerrero, P.; Jorba, O.; Pérez, C.; López, E.; Güereca, P.; Martín, F.; Vivanco, M. G.; Palomino, I.; Querol, X.; Pandolfi, M.; Sanz, M. J.; Diéguez, J. J.

    2008-05-01

    The Caliope project funded by the Spanish Ministry of the Environment establishes an air quality forecasting system for Spain to increase the knowledge on transport and dynamics of pollutants in Spain, to assure the accomplishment of legislation and to inform the population about the levels of pollutants, topics in which the European Commission has shown a great concern. The present contribution describes the first quantitative verification study performed so far with two chemistry transport models (CMAQ and CHIMERE) for a reference year (2004) at medium spatial resolution (around 20×20 km for the Iberian Peninsula). Both models perform similarly in the case of ground-level ozone. The mean normalised gross error MNGE remains below 15-20% during summertime, when ozone episodes occur, outlining the good skills of the system concerning the forecasting of air quality in Spain. Furthermore, the ongoing developments of the system towards high resolution modelling (4×4 km for Spain, 12×12 km for Europe, 1 h temporal resolution) and the integration with observations within the Caliope umbrella are described.

  10. A Novel Approach to Generate Essential New CALIPSO-based Products: Biomass Burning Plume Injection Height Using CALIOP, MODIS and the NASA Langley Trajectory Model

    Science.gov (United States)

    Vaughan, M.; Soja, A. J.; Fairlie, T. D.; Westberg, D. J.; Pouliot, G.

    2012-12-01

    There is a significant connection between biomass burning (BB) emissions, the terrestrial environment and the atmosphere, which has strong implications for feedbacks to Air Quality and to the climate system. BB has the potential to alter numerous land and atmospheric processes and their full influence to feedback to interactive systems is currently being exposed (i.e. black carbon on spring Arctic ice). The heights to which BB emissions are injected influence their transport, their interaction with clouds, which alters albedo, and their ability to modify patterns of precipitation. We are working with our applications partners, primarily the Environmental Protection Agency and regional partners, to generate BB plume injection height products using multiple platforms, sensors and models (CALIOP, MODIS, NOAA HMS, Langley Trajectory Model) that will provide value to national and international scientific and air quality communities, the CALIPSO science and algorithm teams, and to public land, fire, and air quality management and regulations communities. Specifically, we are: (1) developing mean statistics that link CALIOP air parcels and BB injection height to the variables that control these dynamics, which include ecosystems, fire-specific and meteorological variables; and (2) defining the daily evolution of smoke plumes for specific fires. Statistics that link fire behavior and weather to plume rise are crucial for verifying and enhancing plume rise parameterization in regional- and global-scale models used for air quality, chemical transport and climate.

  11. Polarization developments

    International Nuclear Information System (INIS)

    Prescott, C.Y.

    1993-07-01

    Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist

  12. Polarization Measurements in the Vacuum Ultraviolet

    Science.gov (United States)

    West, E. A.; Kobayashi, K.; Noble, M.

    2005-01-01

    This paper will describe the VUV polarization testing of the NSSTC Solar Ultraviolet Magnetograph (SUMI) optics. SUMI is being developed for a sounding rocket payload to prove the feasibility of making magnetic field measurements in the transition region. This paper will cover the polarization properties of the VUV calibration polarizers, the instrumental polarization of the VUV chamber, SUMI's toroidal varied-line-space gratings and the SUMI polarimeter.

  13. VIIRS-J1 Polarization Narrative

    Science.gov (United States)

    Waluschka, Eugene; McCorkel, Joel; McIntire, Jeff; Moyer, David; McAndrew, Brendan; Brown, Steven W.; Lykke, Keith; Butler, James; Meister, Gerhard; Thome, Kurtis J.

    2015-01-01

    The VIS/NIR bands polarization sensitivity of Joint Polar Satellite Sensor 1 (JPSS1) Visible/Infrared Imaging Radiometer Suite (VIIRS) instrument was measured using a broadband source. While polarization sensitivity for bands M5-M7, I1, and I2 was less than 2.5%, the maximum polarization sensitivity for bands M1, M2, M3, and M4 was measured to be 6.4%, 4.4%, 3.1%, and 4.3%, respectively with a polarization characterization uncertainty of less than 0.3%. A detailed polarization model indicated that the large polarization sensitivity observed in the M1 to M4 bands was mainly due to the large polarization sensitivity introduced at the leading and trailing edges of the newly manufactured VISNIR bandpass focal plane filters installed in front of the VISNIR detectors. This was confirmed by polarization measurements of bands M1 and M4 bands using monochromatic light. Discussed are the activities leading up to and including the instruments two polarization tests, some discussion of the polarization model and the model results, the role of the focal plane filters, the polarization testing of the Aft-Optics-Assembly, the testing of the polarizers at Goddard and NIST and the use of NIST's T-SIRCUS for polarization testing and associated analyses and results.

  14. Polarization, political

    NARCIS (Netherlands)

    Wojcieszak, M.; Mazzoleni, G.; Barnhurst, K.G.; Ikeda, K.; Maia, R.C.M.; Wessler, H.

    2015-01-01

    Polarization has been studied in three different forms: on a social, group, and individual level. This entry first focuses on the undisputed phenomenon of elite polarization (i.e., increasing adherence of policy positions among the elites) and also outlines different approaches to assessing mass

  15. Polarization holography

    DEFF Research Database (Denmark)

    Nikolova, L.; Ramanujam, P.S.

    Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

  16. Temporal and spectral cloud screening of polar winter aerosol optical depth (AOD: impact of homogeneous and inhomogeneous clouds and crystal layers on climatological-scale AODs

    Directory of Open Access Journals (Sweden)

    N. T. O'Neill

    2016-10-01

    Full Text Available We compared star-photometry-derived, polar winter aerosol optical depths (AODs, acquired at Eureka, Nunavut, Canada, and Ny-Ålesund, Svalbard, with GEOS-Chem (GC simulations as well as ground-based lidar and CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization retrievals over a sampling period of two polar winters. The results indicate significant cloud and/or low-altitude ice crystal (LIC contamination which is only partially corrected using temporal cloud screening. Spatially homogeneous clouds and LICs that remain after temporal cloud screening represent an inevitable systematic error in the estimation of AOD: this error was estimated to vary from 78 to 210 % at Eureka and from 2 to 157 % at Ny-Ålesund. Lidar analysis indicated that LICs appeared to have a disproportionately large influence on the homogeneous coarse-mode optical depths that escape temporal cloud screening. In principle, spectral cloud screening (to yield fine-mode or submicron AODs reduces pre-cloud-screened AODs to the aerosol contribution if one assumes that coarse-mode (super-micron aerosols are a minor part of the AOD. Large, low-frequency differences between these retrieved values and their GC analogue appeared to be often linked to strong, spatially extensive planetary boundary layer events whose presence at either site was inferred from CALIOP profiles. These events were either not captured or significantly underestimated by the GC simulations. High-frequency AOD variations of GC fine-mode aerosols at Ny-Ålesund were attributed to sea salt, while low-frequency GC variations at Eureka and Ny-Ålesund were attributable to sulfates. CALIOP profiles and AODs were invaluable as spatial and temporal redundancy support (or, alternatively, as insightful points of contention for star photometry retrievals and GC estimates of AOD.

  17. Polarized neutron scattering on HYSPEC: the HYbrid SPECtrometer at SNS

    Energy Technology Data Exchange (ETDEWEB)

    Zaliznyak, Igor [Brookhaven National Laboratory (BNL); Savici, Andrei T [ORNL; Garlea, Vasile O [ORNL; Winn, Barry L [ORNL; Schneelock, John [Brookhaven National Laboratory (BNL); Tranquada, John M. [Brookhaven National Laboratory (BNL); Gu, G. D. [Brookhaven National Laboratory (BNL); Wang, Aifeng [Brookhaven National Laboratory (BNL); Petrovic, C [Brookhaven National Laboratory (BNL)

    2017-01-01

    We describe some of the first polarized neutron scattering measurements performed at HYSPEC spectrometer at the Spallation Neutron Source, Oak Ridge National Laboratory. We discuss details of the instrument setup and the experimental procedures in the mode with the full polarization analysis. Examples of the polarized neutron diffraction and the polarized inelastic neutron data obtained on single crystal samples are presented.

  18. Polar Bears

    Science.gov (United States)

    Amstrup, Steven C.; Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.

    2002-01-01

    Polar bears (Ursus maritimus) are hunted throughout most of their range. In addition to hunting polar bears of the Beaufort Sea region are exposed to mineral and petroleum extraction and related human activities such as shipping road-building, and seismic testing (Stirling 1990).Little was known at the start of this project about how polar bears move about in their environment, and although it was understood that many bears travel across political borders, the boundaries of populations had not been delineated (Amstrup 1986, Amstrup et al. 1986, Amstrup and DeMaster 1988, Garner et al. 1994, Amstrup 1995, Amstrup et al. 1995, Amstrup 2000).As human populations increase and demands for polar bears and other arctic resources escalate, managers must know the sizes and distributions of the polar bear populations. Resource managers also need reliable estimates of breeding rates, reproductive intervals, litter sizes, and survival of young and adults.Our objectives for this research were 1) to determine the seasonal and annual movements of polar bears in the Beaufort Sea, 2) to define the boundaries of the population(s) using this region, 3) to determine the size and status of the Beaufort Sea polar bear population, and 4) to establish reproduction and survival rates (Amstrup 2000).

  19. A climatology of polar stratospheric cloud composition between 2002 and 2012 based on MIPAS/Envisat observations

    Directory of Open Access Journals (Sweden)

    R. Spang

    2018-04-01

    Full Text Available The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS instrument aboard the European Space Agency (ESA Envisat satellite operated from July 2002 to April 2012. The infrared limb emission measurements provide a unique dataset of day and night observations of polar stratospheric clouds (PSCs up to both poles. A recent classification method for PSC types in infrared (IR limb spectra using spectral measurements in different atmospheric window regions has been applied to the complete mission period of MIPAS. The method uses a simple probabilistic classifier based on Bayes' theorem with a strong independence assumption on a combination of a well-established two-colour ratio method and multiple 2-D probability density functions of brightness temperature differences. The Bayesian classifier distinguishes between solid particles of ice, nitric acid trihydrate (NAT, and liquid droplets of supercooled ternary solution (STS, as well as mixed types. A climatology of MIPAS PSC occurrence and specific PSC classes has been compiled. Comparisons with results from the classification scheme of the spaceborne lidar Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP on the Cloud-Aerosol-Lidar and Infrared Pathfinder Satellite Observations (CALIPSO satellite show excellent correspondence in the spatial and temporal evolution for the area of PSC coverage (APSC even for each PSC class. Probability density functions of the PSC temperature, retrieved for each class with respect to equilibrium temperature of ice and based on coincident temperatures from meteorological reanalyses, are in accordance with the microphysical knowledge of the formation processes with respect to temperature for all three PSC types.This paper represents unprecedented pole-covering day- and nighttime climatology of the PSC distributions and their composition of different particle types. The dataset allows analyses on the temporal and spatial development of the PSC formation

  20. A climatology of polar stratospheric cloud composition between 2002 and 2012 based on MIPAS/Envisat observations

    Science.gov (United States)

    Spang, Reinhold; Hoffmann, Lars; Müller, Rolf; Grooß, Jens-Uwe; Tritscher, Ines; Höpfner, Michael; Pitts, Michael; Orr, Andrew; Riese, Martin

    2018-04-01

    The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument aboard the European Space Agency (ESA) Envisat satellite operated from July 2002 to April 2012. The infrared limb emission measurements provide a unique dataset of day and night observations of polar stratospheric clouds (PSCs) up to both poles. A recent classification method for PSC types in infrared (IR) limb spectra using spectral measurements in different atmospheric window regions has been applied to the complete mission period of MIPAS. The method uses a simple probabilistic classifier based on Bayes' theorem with a strong independence assumption on a combination of a well-established two-colour ratio method and multiple 2-D probability density functions of brightness temperature differences. The Bayesian classifier distinguishes between solid particles of ice, nitric acid trihydrate (NAT), and liquid droplets of supercooled ternary solution (STS), as well as mixed types. A climatology of MIPAS PSC occurrence and specific PSC classes has been compiled. Comparisons with results from the classification scheme of the spaceborne lidar Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on the Cloud-Aerosol-Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite show excellent correspondence in the spatial and temporal evolution for the area of PSC coverage (APSC) even for each PSC class. Probability density functions of the PSC temperature, retrieved for each class with respect to equilibrium temperature of ice and based on coincident temperatures from meteorological reanalyses, are in accordance with the microphysical knowledge of the formation processes with respect to temperature for all three PSC types.This paper represents unprecedented pole-covering day- and nighttime climatology of the PSC distributions and their composition of different particle types. The dataset allows analyses on the temporal and spatial development of the PSC formation process over

  1. VIIRS/J1 polarization narrative

    Science.gov (United States)

    Waluschka, Eugene; McCorkel, Joel; McIntire, Jeff; Moyer, David; McAndrew, Brendan; Brown, Steven W.; Lykke, Keith R.; Young, James B.; Fest, Eric; Butler, James; Wang, Tung R.; Monroy, Eslim O.; Turpie, Kevin; Meister, Gerhard; Thome, Kurtis J.

    2015-09-01

    The polarization sensitivity of the Visible/NearIR (VISNIR) bands in the Joint Polar Satellite Sensor 1 (J1) Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was measured using a broadband source. While polarization sensitivity for bands M5-M7, I1, and I2 was less than 2.5 %, the maximum polarization sensitivity for bands M1, M2, M3, and M4 was measured to be 6.4 %, 4.4 %, 3.1 %, and 4.3 %, respectively with a polarization characterization uncertainty of less than 0.38%. A detailed polarization model indicated that the large polarization sensitivity observed in the M1 to M4 bands is mainly due to the large polarization sensitivity introduced at the leading and trailing edges of the newly manufactured VISNIR bandpass focal plane filters installed in front of the VISNIR detectors. This was confirmed by polarization measurements of bands M1 and M4 bands using monochromatic light. Discussed are the activities leading up to and including the two polarization tests, some discussion of the polarization model and the model results, the role of the focal plane filters, the polarization testing of the Aft-Optics-Assembly, the testing of the polarizers at the National Aeronautics and Space Administration's (NASA) Goddard center and at the National Institute of Science and Technology (NIST) facility and the use of NIST's Traveling Spectral Irradiance and Radiance responsivity Calibrations using Uniform Sources (T-SIRCUS) for polarization testing and associated analyses and results.

  2. Hyperspectral Image Projector with Polarization Capability, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal outlines the development of a novel instrument for calibrating satellite based imaging sensors -- the Polarization Hyperspectral Image Projector...

  3. Radioisotope instruments

    CERN Document Server

    Cameron, J F; Silverleaf, D J

    1971-01-01

    International Series of Monographs in Nuclear Energy, Volume 107: Radioisotope Instruments, Part 1 focuses on the design and applications of instruments based on the radiation released by radioactive substances. The book first offers information on the physical basis of radioisotope instruments; technical and economic advantages of radioisotope instruments; and radiation hazard. The manuscript then discusses commercial radioisotope instruments, including radiation sources and detectors, computing and control units, and measuring heads. The text describes the applications of radioisotop

  4. Assessment of the CALIPSO Lidar 532 nm attenuated backscatter calibration using the NASA LaRC airborne High Spectral Resolution Lidar

    Directory of Open Access Journals (Sweden)

    R. R. Rogers

    2011-02-01

    Full Text Available The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP instrument on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO spacecraft has provided global, high-resolution vertical profiles of aerosols and clouds since it became operational on 13 June 2006. On 14 June 2006, the NASA Langley Research Center (LaRC High Spectral Resolution Lidar (HSRL was deployed aboard the NASA Langley B-200 aircraft for the first of a series of 86 underflights of the CALIPSO satellite to provide validation measurements for the CALIOP data products. To better assess the range of conditions under which CALIOP data products are produced, these validation flights were conducted under both daytime and nighttime lighting conditions, in multiple seasons, and over a large range of latitudes and aerosol and cloud conditions. This paper presents a quantitative assessment of the CALIOP 532 nm calibration (through the 532 nm total attenuated backscatter using internally calibrated airborne HSRL underflight data and is the most extensive study of CALIOP 532 nm calibration. Results show that HSRL and CALIOP 532 nm total attenuated backscatter agree on average within 2.7% ± 2.1% (CALIOP lower at night and within 2.9% ± 3.9% (CALIOP lower during the day, demonstrating the accuracy of the CALIOP 532 nm calibration algorithms. Additionally, comparisons with HSRL show consistency of the CALIOP calibration before and after the laser switch in 2009 as well as improvements in the daytime version 3.01 calibration scheme compared with the version 2 calibration scheme. Potential biases and uncertainties in the methodology relevant to validating satellite lidar measurements with an airborne lidar system are discussed and found to be less than 4.5% ± 3.2% for this validation effort with HSRL. Results from this study are also compared with prior assessments of the CALIOP 532 nm attenuated backscatter calibration.

  5. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from USCGC POLAR STAR in the Arctic Ocean from 2002-08-19 to 2002-09-23 (NODC Accession 0115588)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0115588 includes discrete sample and profile data collected from USCGC POLAR STAR in the Arctic Ocean from 2002-08-19 to 2002-09-23. These data...

  6. The First Polarization Maps from the GMRT

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... We present the first set of polarimetric images made with the GMRT. We find that the instrumental polarization leakage at the GMRT varies with frequency. It is possible to calibrate these terms to better than 1% accuracy, making it feasible to study sources that are polarized at the few per cent level.

  7. Political polarization

    OpenAIRE

    Dixit, Avinash K.; Weibull, Jörgen W.

    2007-01-01

    Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality.

  8. Political polarization.

    Science.gov (United States)

    Dixit, Avinash K; Weibull, Jörgen W

    2007-05-01

    Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality.

  9. Evaluating the CALIOPE air quality modelling system: dynamics and chemistry over Europe and Iberian Peninsula for 2004 at high horizontal resolution

    Science.gov (United States)

    Piot, M.; Pay, M. T.; Jorba, O.; Baldasano, J. M.; Jiménez-Guerrero, P.; López, E.; Pérez, C.; Gassó, S.

    2009-04-01

    Often in Europe, population exposure to air pollution exceeds standards set by the EU and the World Health Organization (WHO). Urban/suburban areas are predominantly impacted upon, although exceedances of particulate matter (PM10 and PM2.5) and Ozone (O3) also take place in rural areas. In the frame of the CALIOPE project (Baldasano et al., 2008a), a high-resolution air quality forecasting system, WRF-ARW/HERMES/CMAQ/DREAM, has been developed and applied to the European domain (12km x 12km, 1hr) as well as to the Iberian Peninsula domain (4km x 4km, 1hr) to provide air quality forecasts for Spain (http://www.bsc.es/caliope/). The simulation of such high-resolution model system has been made possible by its implementation on the MareNostrum supercomputer. To reassure potential users and reduce uncertainties, the model system must be evaluated to assess its performances in terms of air quality levels and dynamics reproducibility. The present contribution describes a thorough quantitative evaluation study performed for a reference year (2004). The CALIOPE modelling system is configured with 38 vertical layers reaching up to 50 hPa for the meteorological core. Atmospheric initial and boundary conditions are obtained from the NCEP final analysis data. The vertical resolution of the CMAQ chemistry-transport model for gas-phase and aerosols has been increased from 8 to 15 layers in order to simulate vertical exchanges more accurately. Gas phase boundary conditions are provided by the LMDz-INCA2 global climate-chemistry model (see Hauglustaine et al., 2004). The DREAM model simulates long-range transport of mineral dust over the domains under study. For the European simulation, emissions are disaggregated from the EMEP expert emission inventory for 2004 to the utilized resolution using the criteria implemented in the HERMES emission model (Baldasano et al., 2008b). The HERMES model system, using a bottom-up approach, was adopted to estimate emissions for the Iberian

  10. Plasma polarization spectroscopy

    CERN Document Server

    Iwamae, Atsushi

    2008-01-01

    Plasma Polarization Spectroscopy (PPS) is now becoming a standard diagnostic technique for working with laboratory plasmas. This new area needs a comprehensive framework, both experimental and theoretical. This book reviews the historical development of PPS, develops a general theoretical formulation to deal with this phenomenon, along with an overview of relevant cross sections, and reports on laboratory experiments so far performed. It also includes various facets that are interesting from this standpoint, e.g. X-ray lasers and effects of microwave irradiation. It also offers a timely discussion of instrumentation that is quite important in a practical PPS experiment.

  11. Spontaneous growth of polarizing refractory metal ‘nano-fins’

    Science.gov (United States)

    Tai, M. C.; Gentle, A. R.; Arnold, M. D.; Cortie, M. B.

    2018-03-01

    Traditional polymer polarizers degrade in harsh environments and at high temperatures, reducing the polarization effect. In contrast, polarizers produced with refractory metals have vastly improved thermal stability and resistance to harsh environments but are expensive to fabricate. Here we demonstrate prototype refractory metal wire grid polarizers produced by co-sputtering molybdenum and aluminum under specific conditions. Removal of the aluminum through selective dissolution enables the nanostructure array to transmit light. The polarization spans 500–1100 nm and the extinction ratio significantly increases to >100. Possessing broadband polarization and sufficient extinction ratios, the new polarizing film has potential applications in coatings for sunglasses, windows, pyrometers, scientific instruments, and LCD panels.

  12. CMB polarization at large angular scales: Data analysis of the POLAR experiment

    International Nuclear Information System (INIS)

    O'Dell, Christopher W.; Keating, Brian G.; Oliveira-Costa, Angelica de; Tegmark, Max; Timbie, Peter T.

    2003-01-01

    The coming flood of cosmic microwave background (CMB) polarization experiments, spurred by the recent detection of CMB polarization by the DASI and WMAP instruments, will be confronted by many new analysis tasks specific to polarization. For the analysis of CMB polarization data sets, the devil is truly in the details. With this in mind, we present details of the data analysis for the POLAR experiment, which recently led to the tightest upper limits on the polarization of the cosmic microwave background radiation at large angular scales. We discuss the data selection process, map-making algorithms, offset removal, and likelihood analysis which were used to find upper limits on the polarization. Stated using the modern convention for reporting CMB Stokes parameters, these limits are 5.0 μK on both E- and B-type polarization at 95% confidence. Finally, we discuss simulations used to test our analysis techniques and to probe the fundamental limitations of the experiment

  13. PIPER: Primordial Inflation Polarization Explorer

    Science.gov (United States)

    Lazear, Justin; Benford, D.; Chuss, D.; Fixsen, D.; Hinderks, J.; Hinshaw, G.; Jhabvala, C.; Johnson, B.; Kogut, A.; Mirel, P.; Mosely, H.; Staguhn, J.; Wollack, E.; Weston, A.; Vlahacos, K.; Bennett, C.; Eimer, J.; Halpern, M.; Irwin, K.; Dotson, J.; Ade, P.; Tucker, C.

    2011-05-01

    The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne instrument to measure the polarization of the cosmic microwave background in search of the expected signature of primordial gravity waves excited during an inflationary epoch shortly after the Big Bang. PIPER consists of two co-aligned telescopes, one sensitive to the Q Stokes parameter and the other to U. Sky signals will be detected with 5120 transition edge sensor (TES) bolometers distributed in four rectangular close-packed arrays maintained at 100 mK. To maximize the sensitivity of the instrument, both telescopes are mounted within a single open bucket dewar and are maintained at 1.5 K throughout flight, with no ambient-temperature windows between the sky and the detectors. To mitigate the effects of systematic errors, the polarized sky signals will be modulated using a variable-delay polarization modulator. PIPER will observe at frequencies 200, 270, 350, and 600 GHz to separate the CMB from polarized dust emission within the Galaxy. A series of flights alternating between northern and southern hemisphere launch sites will produce nearly full-sky maps in Stokes I, Q, U, and V. I will discuss the current status and potential science returns from the PIPER project.

  14. Strategic Polarization.

    Science.gov (United States)

    Kalai, Adam; Kalai, Ehud

    2001-08-01

    In joint decision making, similarly minded people may take opposite positions. Consider the example of a marriage in which one spouse gives generously to charity while the other donates nothing. Such "polarization" may misrepresent what is, in actuality, a small discrepancy in preferences. It may be that the donating spouse would like to see 10% of their combined income go to charity each year, while the apparently frugal spouse would like to see 8% donated. A simple game-theoretic analysis suggests that the spouses will end up donating 10% and 0%, respectively. By generalizing this argument to a larger class of games, we provide strategic justification for polarization in many situations such as debates, shared living accommodations, and disciplining children. In some of these examples, an arbitrarily small disagreement in preferences leads to an arbitrarily large loss in utility for all participants. Such small disagreements may also destabilize what, from game-theoretic point of view, is a very stable equilibrium. Copyright 2001 Academic Press.

  15. Observing the Cosmic Microwave Background Polarization with Variable-delay Polarization Modulators for the Cosmology Large Angular Scale Surveyor

    Science.gov (United States)

    Harrington, Kathleen; CLASS Collaboration

    2018-01-01

    The search for inflationary primordial gravitational waves and the optical depth to reionization, both through their imprint on the large angular scale correlations in the polarization of the cosmic microwave background (CMB), has created the need for high sensitivity measurements of polarization across large fractions of the sky at millimeter wavelengths. These measurements are subjected to instrumental and atmospheric 1/f noise, which has motivated the development of polarization modulators to facilitate the rejection of these large systematic effects.Variable-delay polarization modulators (VPMs) are used in the Cosmology Large Angular Scale Surveyor (CLASS) telescopes as the first element in the optical chain to rapidly modulate the incoming polarization. VPMs consist of a linearly polarizing wire grid in front of a moveable flat mirror; varying the distance between the grid and the mirror produces a changing phase shift between polarization states parallel and perpendicular to the grid which modulates Stokes U (linear polarization at 45°) and Stokes V (circular polarization). The reflective and scalable nature of the VPM enables its placement as the first optical element in a reflecting telescope. This simultaneously allows a lock-in style polarization measurement and the separation of sky polarization from any instrumental polarization farther along in the optical chain.The Q-Band CLASS VPM was the first VPM to begin observing the CMB full time in 2016. I will be presenting its design and characterization as well as demonstrating how modulating polarization significantly rejects atmospheric and instrumental long time scale noise.

  16. Instrumentation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Provides instrumentation support for flight tests of prototype weapons systems using a vast array of airborne sensors, transducers, signal conditioning and encoding...

  17. Minimum aerosol layer detection sensitivities and their subsequent impacts on aerosol optical thickness retrievals in CALIPSO level 2 data products

    Science.gov (United States)

    Toth, Travis D.; Campbell, James R.; Reid, Jeffrey S.; Tackett, Jason L.; Vaughan, Mark A.; Zhang, Jianglong; Marquis, Jared W.

    2018-01-01

    Due to instrument sensitivities and algorithm detection limits, level 2 (L2) Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) 532 nm aerosol extinction profile retrievals are often populated with retrieval fill values (RFVs), which indicate the absence of detectable levels of aerosol within the profile. In this study, using 4 years (2007-2008 and 2010-2011) of CALIOP version 3 L2 aerosol data, the occurrence frequency of daytime CALIOP profiles containing all RFVs (all-RFV profiles) is studied. In the CALIOP data products, the aerosol optical thickness (AOT) of any all-RFV profile is reported as being zero, which may introduce a bias in CALIOP-based AOT climatologies. For this study, we derive revised estimates of AOT for all-RFV profiles using collocated Moderate Resolution Imaging Spectroradiometer (MODIS) Dark Target (DT) and, where available, AErosol RObotic NEtwork (AERONET) data. Globally, all-RFV profiles comprise roughly 71 % of all daytime CALIOP L2 aerosol profiles (i.e., including completely attenuated profiles), accounting for nearly half (45 %) of all daytime cloud-free L2 aerosol profiles. The mean collocated MODIS DT (AERONET) 550 nm AOT is found to be near 0.06 (0.08) for CALIOP all-RFV profiles. We further estimate a global mean aerosol extinction profile, a so-called noise floor, for CALIOP all-RFV profiles. The global mean CALIOP AOT is then recomputed by replacing RFV values with the derived noise-floor values for both all-RFV and non-all-RFV profiles. This process yields an improvement in the agreement of CALIOP and MODIS over-ocean AOT.

  18. Precessing deuteron polarization

    International Nuclear Information System (INIS)

    Sitnik, I.M.; Volkov, V.I.; Kirillov, D.A.; Piskunov, N.M.; Plis, Yu.A.

    2002-01-01

    The feasibility of the acceleration in the Nuclotron of deuterons polarized in the horizontal plane is considered. This horizontal polarization is named precessing polarization. The effects of the main magnetic field and synchrotron oscillations are included. The precessing polarization is supposed to be used in studying the polarization parameters of the elastic dp back-scattering and other experiments

  19. The Evaluation of the Spanish Air Quality Modelling System: CALIOPE. Dynamics and Chemistry over Europe and Iberian Peninsula for 2004 at high horizontal resolution

    Science.gov (United States)

    Piot, M.; Pay, M.; Jorba, O.; Lopez, E.; Pirez, C.; Gasso, S.; Baldasano, J. M.

    2009-12-01

    In Europe, human exposure to air pollution often exceeds standards set by the EU commission (Directives 1996/62/EC, 2002/3/EC, 2008/50/EC) and the World Health Organization (WHO). Urban/suburban areas are predominantly impacted upon, although exceedances of particulate matter (PM10 and PM2.5) and Ozone (O3) also take place in rural areas. Within the CALIOPE project, a high-resolution air quality forecasting system, namely WRF-ARW/HERMES04/CMAQ/BSC-DREAM, has been developed and applied to the European domain (12x12 sq. km, 1hr) as well as the Spanish domain (4x4 sq. km, 1hr). The simulation of such high-resolution model system has been made possible by its implementation on the MareNostrum supercomputer. This contribution describes a thorough quantitative evaluation study performed for the reference year 2004. The WRF-ARW meteorological model contains 38 vertical layers reaching up to 50 hPa. The vertical resolution of the CMAQ chemistry-transport model for gas-phase and aerosols has been increased from 8 to 15 layers in order to simulate vertical exchanges more accurately. Gas phase boundary conditions are provided by the LMDz-INCA2 global climate-chemistry model. For the European simulation, emissions are disaggregated from the EMEP emission inventory for 2004 to the utilized resolution using the criteria implemented in the HERMES04 emission model. The HERMES04 model system, running through a bottom-up approach, is used to estimate emissions for Spain at a 1x1 sq. km horizontal resolution, every hour. In order to evaluate the performances of the CALIOPE system, the model simulation for Europe was compared with ground-based measurements from the EMEP and the Spanish air quality networks (total of 60 stations for O3, 43 for NO2, 31 for SO2, 25 for PM10 and 16 for PM2.5). The model simulation for Europe satisfactorily reproduces O3 concentrations throughout the year (annual correlation: 0.66) with relatively small errors: MNGE values range from 13% to 26%, and MNBE

  20. Constraining Polarized Foregrounds for EoR Experiments. II. Polarization Leakage Simulations in the Avoidance Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Nunhokee, C. D.; Bernardi, G.; Foster, G.; Grobler, T. L. [Department of Physics and Electronics, Rhodes University, P.O. Box 94, Grahamstown, 6140 (South Africa); Kohn, S. A.; Aguirre, J. E.; Martinot, J. Z. E. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA (United States); Thyagarajan, N. [Arizona State University, School of Earth and Space Exploration, Tempe, AZ 85287 (United States); Dillon, J. S. [Berkeley Center for Cosmological Physics, Berkeley, CA 94720 (United States); Parsons, A. R., E-mail: cnunhokee@gmail.com [Dept. of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2017-10-10

    A critical challenge in the observation of the redshifted 21 cm line is its separation from bright Galactic and extragalactic foregrounds. In particular, the instrumental leakage of polarized foregrounds, which undergo significant Faraday rotation as they propagate through the interstellar medium, may harmfully contaminate the 21 cm power spectrum. We develop a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra measured with redundant arrays, extending the delay-spectrum approach presented in Parsons et al. We construct polarized sky models and propagate them through the instrument model to simulate realistic full-sky observations with the Precision Array to Probe the Epoch of Reionization. We find that the leakage due to a population of polarized point sources is expected to be higher than diffuse Galactic polarization at any k mode for a 30 m reference baseline. For the same reference baseline, a foreground-free window at k > 0.3 h Mpc{sup −1} can be defined in terms of leakage from diffuse Galactic polarization even under the most pessimistic assumptions. If measurements of polarized foreground power spectra or a model of polarized foregrounds are given, our method is able to predict the polarization leakage in actual 21 cm observations, potentially enabling its statistical subtraction from the measured 21 cm power spectrum.

  1. Polare maskuliniteter

    Directory of Open Access Journals (Sweden)

    Marit Anne Hauan

    2012-05-01

    Full Text Available In this paper my aim is to read and understand the journal of Gerrit de Veer from the last journey of William Barents to the Arctic Regions in 1596 and the journal of captain Junge on his hunting trip from Tromsø to Svalbard in 1834.It is nearly 240 years between this to voyages. The first journal is known as the earliest report from the arctic era. Gerrit de Veer adds instructive copper engravings to his text and give us insight in the crews meeting with this new land. Captain Junges journal is found together with his dead crew in a house in a fjord nearby Ny-Ålesund and has no drawings, but word. Both of these journals may be read as sources of the knowledge and understanding of the polar region. They might also unveil the ideas of how to deal with and survive under the challenges that is given. In addition one can ask if the sources can tell us more about how men describe their challenges. Can the way they expressed themselves in the journals give us an understanding of masculinity? And not least help us to create good questions of the change in the ideas of masculinities which is said to follow the change in understanding of the wilderness.

  2. Luminescence Instrumentation

    DEFF Research Database (Denmark)

    Jain, Mayank; Bøtter-Jensen, Lars

    2014-01-01

    This chapter gives an introduction to instrumentation for stimulated luminescence studies, with special focus on luminescence dating using the natural dosimeters, quartz and feldspars. The chapter covers basic concepts in luminescence detection, and thermal and optical stimulation, and reference...

  3. Instrumental analysis

    International Nuclear Information System (INIS)

    Kim, Seung Jae; Seo, Seong Gyu

    1995-03-01

    This textbook deals with instrumental analysis, which consists of nine chapters. It has Introduction of analysis chemistry, the process of analysis and types and form of the analysis, Electrochemistry on basic theory, potentiometry and conductometry, electromagnetic radiant rays and optical components on introduction and application, Ultraviolet rays and Visible spectrophotometry, Atomic absorption spectrophotometry on introduction, flame emission spectrometry and plasma emission spectrometry. The others like infrared spectrophotometry, X-rays spectrophotometry and mass spectrometry, chromatography and the other instrumental analysis like radiochemistry.

  4. Construction and exploitation of new remote sensing instruments

    Science.gov (United States)

    Maekisara, Kai

    Finnish investigations into the construction of near future instruments, descriptive and programmable, are outlined. The following instruments are discussed: the Medium Resolution Imaging Spectrometer (MERIS) and the High Resolution Imaging Spectrometer (HRIS) of the Polar Platform; lidar (light and detection ranging); the Earth Resources Satellite-1 (ERS-1) and Radarsat synthetic aperture radar; and the Advanced Microwave Sounding Unit-A (AMSU-A) and the Advanced Microwave Sounding Unit-B (AMSU-B) Polar Platform microwave instruments.

  5. Instrumental Capital

    Directory of Open Access Journals (Sweden)

    Gabriel Valerio

    2007-07-01

    Full Text Available During the history of human kind, since our first ancestors, tools have represented a mean to reach objectives which might otherwise seemed impossibles. In the called New Economy, where tangibles assets appear to be losing the role as the core element to produce value versus knowledge, tools have kept aside man in his dairy work. In this article, the author's objective is to describe, in a simple manner, the importance of managing the organization's group of tools or instruments (Instrumental Capital. The characteristic conditions of this New Economy, the way Knowledge Management deals with these new conditions and the sub-processes that provide support to the management of Instrumental Capital are described.

  6. Innovative instrumentation

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    At this year's particle physics conference at Brighton, a parallel session was given over to instrumentation and detector development. While this work is vital to the health of research and its continued progress, its share of prime international conference time is limited. Instrumentation can be innovative three times — first when a new idea is outlined, secondly when it is shown to be feasible, and finally when it becomes productive in a real experiment, amassing useful data rather than operational experience. Hyams' examples showed that it can take a long time for a new idea to filter through these successive stages, if it ever makes it at all

  7. Instrumented SSH

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Scott; Campbell, Scott

    2009-05-27

    NERSC recently undertook a project to access and analyze Secure Shell (SSH) related data. This includes authentication data such as user names and key fingerprints, interactive session data such as keystrokes and responses, and information about noninteractive sessions such as commands executed and files transferred. Historically, this data has been inaccessible with traditional network monitoring techniques, but with a modification to the SSH daemon, this data can be passed directly to intrusion detection systems for analysis. The instrumented version of SSH is now running on all NERSC production systems. This paper describes the project, details about how SSH was instrumented, and the initial results of putting this in production.

  8. Monitoring of the Polar Stratospheric Clouds formation and evolution in Antarctica in August 2007 during IPY with the MATCH method applied to lidar data

    Science.gov (United States)

    Montoux, Nadege; David, Christine; Klekociuk, Andrew; Pitts, Michael; di Liberto, Luca; Snels, Marcel; Jumelet, Julien; Bekki, Slimane; Larsen, Niels

    2010-05-01

    The project ORACLE-O3 ("Ozone layer and UV RAdiation in a changing CLimate Evaluated during IPY") is one of the coordinated international proposals selected for the International Polar Year (IPY). As part of this global project, LOLITA-PSC ("Lagrangian Observations with Lidar Investigations and Trajectories in Antarctica and Arctic, of PSC") is devoted to Polar Stratospheric Clouds (PSC) studies. Indeed, understanding the formation and evolution of PSC is an important issue to quantify the impact of climate changes on their frequency of formation and, further, on chlorine activation and subsequent ozone depletion. In this framework, three lidar stations performed PSC observations in Antarctica during the 2006, 2007, and 2008 winters: Davis (68.58°S, 77.97°E), McMurdo (77.86°S, 166.48°E) and Dumont D'Urville (66.67°S, 140.01°E). The data are completed with the lidar data from CALIOP ("Cloud-Aerosol Lidar with Orthogonal Polarization") onboard the CALIPSO ("Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation") satellite. Lagrangian trajectory calculations are used to identify air masses with PSCs sounded by several ground-based lidar stations with the same method, called MATCH, applied for the first time in Arctic to study the ozone depletion with radiosoundings. The evolution of the optical properties of the PSCs and thus the type of PSCs formed (supercooled ternary solution, nitric acid trihydrate particles or ice particles) could thus be linked to the thermodynamical evolution of the air mass deduced from the trajectories. A modeling with the microphysical model of the Danish Meteorological Institute allows assessing our ability to predict PSCs for various environmental conditions. Indeed, from pressure and temperature evolution, the model allows retrieving the types of particles formed as well as their mean radii, their concentrations and could also simulate the lidar signals. In a first step, a case in August 2007 around 17-18 km, involving

  9. Active instruments

    DEFF Research Database (Denmark)

    Lim, Miguel Antonio; Ørberg, Jakob Williams

    2017-01-01

    ) show the dynamic nature of policy processes, and (3) consider the search for policy reference points among the different actors. We present rankers in motion, policies in motion, and finally the complex nature of the ranking device that needs to be both a relevant and malleable policy instrument...

  10. Seismic instrumentation

    International Nuclear Information System (INIS)

    Maubach, K.

    1982-01-01

    For better understanding of the specification for seismic instrumentation of a nuclear power plant, the lecture gives some fundamental remarks to the seismic risk in the Federal Republic of Germany and to the data characterizing an earthquake event. Coming from the geophysical properties of an earthquake, the quantities are explained which are used in the design process of nuclear power plants. This process is shortly described in order to find the requirements for the specification of the seismic instrumentation. In addition the demands of licensing authorities are given. As an example the seismic instrumentation of KKP-1, BWR, is shown. The paper deals with kind and number of instruments, their location in the plant and their sensitivity and calibration. Final considerations deal with the evaluation of measured data and with plant operation after an earthquake. Some experience concerning the earthquake behaviour of equipment not designed to withstand earthquake loads is mentioned. This experience has initiated studies directed to quantification of the degree of conservatism of the assumptions in the seismic design of nuclear power plants. A final garget of these studies are more realistic design rules. (RW)

  11. Polarized electron sources

    Energy Technology Data Exchange (ETDEWEB)

    Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

    1994-12-01

    The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

  12. Aerosols in the CALIOPE air quality modelling system: evaluation and analysis of PM levels, optical depths and chemical composition over Europe

    Directory of Open Access Journals (Sweden)

    S. Basart

    2012-04-01

    Full Text Available The CALIOPE air quality modelling system is developed and applied to Europe with high spatial resolution (12 km × 12 km. The modelled daily-to-seasonal aerosol variability over Europe in 2004 is evaluated and analysed. Aerosols are estimated from two models, CMAQv4.5 (AERO4 and BSC-DREAM8b. CMAQv4.5 calculates biogenic, anthropogenic and sea salt aerosol and BSC-DREAM8b provides the natural mineral dust contribution from North African deserts. For the evaluation, we use daily PM10, PM2.5 and aerosol components data from 55 stations of the EMEP/CREATE network and total, coarse and fine aerosol optical depth (AOD data from 35 stations of the AERONET sun photometer network. Annual correlations between modelled and observed values for PM10 and PM2.5 are 0.55 and 0.47, respectively. Correlations for total, coarse and fine AOD are 0.51, 0.63, and 0.53, respectively. The higher correlations of the PM10 and the coarse mode AOD are largely due to the accurate representation of the African dust influence in the forecasting system. Overall PM and AOD levels are underestimated. The evaluation of the aerosol components highlights underestimations in the fine fraction of carbonaceous matter (EC and OC and secondary inorganic aerosols (SIA; i.e. nitrate, sulphate and ammonium. The scores of the bulk parameters are significantly improved after applying a simple model bias correction based on the observed aerosol composition. The simulated PM10 and AOD present maximum values over the industrialized and populated Po Valley and Benelux regions. SIA are dominant in the fine fraction representing up to 80% of the aerosol budget in latitudes north of 40° N. In southern Europe, high PM10 and AOD are linked to the desert dust transport from the Sahara which contributes up to 40% of the aerosol budget. Maximum seasonal ground-level concentrations (PM10 > 30 μg m−3 are

  13. Inter-comparison between HERMESv2.0 and TNO-MACC-II emission data using the CALIOPE air quality system (Spain)

    Science.gov (United States)

    Guevara, Marc; Pay, María Teresa; Martínez, Francesc; Soret, Albert; Denier van der Gon, Hugo; Baldasano, José M.

    2014-12-01

    This work examines and compares the performance of two emission datasets on modelling air quality concentrations for Spain: (i) the High-Elective Resolution Modelling Emissions System (HERMESv2.0) and (ii) the TNO-MACC-II emission inventory. For this purpose, the air quality system CALIOPE-AQFS (WRF-ARW/CMAQ/BSC-DREAM8b) was run over Spain for February and June 2009 using the two emission datasets (4 km × 4 km and 1 h). Nitrogen dioxide (NO2), sulphur dioxide (SO2), Ozone (O3) and particular matter (PM10) modelled concentrations were compared with measurements at different type of air quality stations (i.e. rural background, urban, suburban industrial). A preliminary emission comparison showed significant discrepancies between the two datasets, highlighting an overestimation of industrial emissions in urban areas when using TNO-MACC-II. However, simulations showed similar performances of both emission datasets in terms of air quality. Modelled NO2 concentrations were similar between both datasets at the background stations, although TNO-MACC-II presented lower underestimations due to differences in industrial, other mobile sources and residential emissions. At Madrid urban stations NO2 was significantly underestimated in both cases despite the fact that HERMESv2.0 estimates traffic emissions using a more local information and detailed methodology. This NO2 underestimation problem was not found in Barcelona due to the influence of international shipping emissions located in the coastline. An inadequate characterization of some TNO-MACC-II's point sources led to high SO2 biases at industrial stations, especially in northwest Spain where large facilities are grouped. In general, surface O3 was overestimated regardless of the emission dataset used, depicting the problematic of CMAQ on overestimating low ozone at night. On the other hand, modelled PM10 concentrations were less underestimated in urban areas when applying HERMESv2.0 due to the inclusion of road dust

  14. Instrumentation development

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Areas being investigated for instrumentation improvement during low-level pollution monitoring include laser opto-acoustic spectroscopy, x-ray fluorescence spectroscopy, optical fluorescence spectroscopy, liquid crystal gas detectors, advanced forms of atomic absorption spectroscopy, electro-analytical chemistry, and mass spectroscopy. Emphasis is also directed toward development of physical methods, as opposed to conventional chemical analysis techniques for monitoring these trace amounts of pollution related to energy development and utilization

  15. Nuclear instrumentation

    International Nuclear Information System (INIS)

    Weill, Jacky; Fabre, Rene.

    1981-01-01

    This article sums up the Research and Development effort at present being carried out in the five following fields of applications: Health physics and Radioprospection, Control of nuclear reactors, Plant control (preparation and reprocessing of the fuel, testing of nuclear substances, etc.), Research laboratory instrumentation, Detectors. It also sets the place of French industrial activities by means of an estimate of the French market, production and flow of trading with other countries [fr

  16. Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite Polarization Sensitivity Analysis

    Science.gov (United States)

    Sun, Junqiang; Xiong, Xiaoxiong; Waluschka, Eugene; Wang, Menghua

    2016-01-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) is one of five instruments onboard the Suomi National Polar-Orbiting Partnership (SNPP) satellite that launched from Vandenberg Air Force Base, California, on October 28, 2011. It is a whiskbroom radiometer that provides +/-56.28deg scans of the Earth view. It has 22 bands, among which 14 are reflective solar bands (RSBs). The RSBs cover a wavelength range from 410 to 2250 nm. The RSBs of a remote sensor are usually sensitive to the polarization of incident light. For VIIRS, it is specified that the polarization factor should be smaller than 3% for 410 and 862 nm bands and 2.5% for other RSBs for the scan angle within +/-45deg. Several polarization sensitivity tests were performed prelaunch for SNPP VIIRS. The first few tests either had large uncertainty or were less reliable, while the last one was believed to provide the more accurate information about the polarization property of the instrument. In this paper, the measured data in the last polarization sensitivity test are analyzed, and the polarization factors and phase angles are derived from the measurements for all the RSBs. The derived polarization factors and phase angles are band, detector, and scan angle dependent. For near-infrared bands, they also depend on the half-angle mirror side. Nevertheless, the derived polarization factors are all within the specification, although the strong detector dependence of the polarization parameters was not expected. Compared to the Moderate Resolution Imaging Spectroradiometer on both Aqua and Terra satellites, the polarization effect on VIIRS RSB is much smaller.

  17. Hydrogen Distribution in the Lunar Polar Regions

    Science.gov (United States)

    Sanin, A. B.; Mitrofanov, I. G.; Litvak, M. L.; Bakhtin, B. N.; Bodnarik, J. G.; Boynton, W. V.; Chin, G.; Evans, L. G.; Harshmann, K.; Fedosov, F.; hide

    2016-01-01

    We present a method of conversion of the lunar neutron counting rate measured by the Lunar Reconnaissance Orbiter (LRO) Lunar Exploration Neutron Detector (LEND) instrument collimated neutron detectors, to water equivalent hydrogen (WEH) in the top approximately 1 m layer of lunar regolith. Polar maps of the Moon’s inferred hydrogen abundance are presented and discussed.

  18. The results from BESS-Polar experiment

    Science.gov (United States)

    Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Kim, K. C.; Lee, M. H.; Makida, Y.; Mitchell, J. W.; Nishimura, J.; Nozaki, M.; Orito, R.; Ormes, J. F.; Picot-Clemente, N.; Sakai, K.; Sasaki, M.; Seo, E. S.; Streitmatter, R. E.; Suzuki, J.; Tanaka, K.; Thakur, N.; Yamamoto, A.; Yoshida, T.; Yoshimura, K.

    2017-08-01

    The balloon-borne experiment with a superconducting spectrometer (BESS) instrument was developed as a high-resolution, high-geometric-acceptance magnetic-rigidity spectrometer for sensitive measurements of cosmic-ray antiparticles, searches for antinuclei, and precise measurements of the absolute fluxes of light GCR elements and isotopes. The original BESS experiment flew 8 times over Lynn Lake, Canada and once from Fort Sumner, USA during the period of 1993 through 2002, with continuous improvement in the instrument. Based on the instrument concept inherited from the BESS spectrometer, a very low instrumental energy cutoff for antiprotons was achieved with a new thin-walled superconducting magnet and removal of the outer pressure vessel for BESS-Polar project. The first and second scientific flights called BESS-Polar I/II were successfully performed, over Antarctica in 2004 December and 2007 December respectively. We report the scientific results, focusing on the long-duration flights of BESS-Polar I (2004) and BESS-Polar II (2007-2008).

  19. Polarized neutrons for Australian scientific research

    International Nuclear Information System (INIS)

    Kennedy, Shane J.

    2005-01-01

    Polarized neutron scattering has been a feature at ANSTO's HIFAR research reactor since the first polarization analysis (PA) spectrometer Longpol began operation over 30 years ago. Since that time, we have improved performance of Longpol and added new capabilities in several reincarnations of the instrument. Most of the polarized neutron experiments have been in the fields of magnetism and superconductivity, and most of that research has involved PA. Now as we plan our next generation neutron beam facility, at the Replacement Research Reactor (RRR), we intend to continue the tradition of PA but with a far broader scope in mind. Our new capabilities will combine PA and energy analysis with both cold and thermal neutron source spectra. We will also provide capabilities for research with polarized neutrons in small-angle neutron scattering and in neutron reflectometry. The discussion includes a brief historical account of the technical developments with a summary of past and present applications of polarized neutrons at HIFAR, and an outline of the polarized neutron capabilities that will be included in the first suite of instruments, which will begin operation at the new reactor in 2006

  20. Geographical Income Polarization

    DEFF Research Database (Denmark)

    Azhar, Hussain; Jonassen, Anders Bruun

    inter municipal income inequality. Counter factual simulations show that rising property prices to a large part explain the rise in polarization. One side-effect of polarization is tendencies towards a parallel polarization of residence location patterns, where low skilled individuals tend to live......In this paper we estimate the degree, composition and development of geographical income polarization based on data at the individual and municipal level in Denmark from 1984 to 2002. Rising income polarization is reconfirmed when applying new polarization measures, the driving force being greater...

  1. Polarized Light Corridor Demonstrations.

    Science.gov (United States)

    Davies, G. R.

    1990-01-01

    Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

  2. Polarized Moessbauer transitions

    International Nuclear Information System (INIS)

    Barb, D.

    1975-01-01

    Theoretical aspects of the emission, absorption and scattering of polarized gamma rays are reviewed for a general case of combined magnetic and electric hyperfine interactions; various possibilities of obtaining polarized gamma sources are described and examples are given of the applications of Moessbauer spectroscopy with polarized gamma rays in solving problems of solid state physics. (A.K.)

  3. Polarization Calibration of the Chromospheric Lyman-Alpha SpectroPolarimeter for a 0.1% Polarization Sensitivity in the VUV Range. Part II: In-Flight Calibration

    Science.gov (United States)

    Giono, G.; Ishikawa, R.; Narukage, N.; Kano, R.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.; Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.; Tsuneta, S.; Shimizu, T.; Sakao, T.; Cirtain, J.; Champey, P.; Asensio Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.

    2017-04-01

    The Chromospheric Lyman-Alpha SpectroPolarimeter is a sounding rocket instrument designed to measure for the first time the linear polarization of the hydrogen Lyman-{α} line (121.6 nm). The instrument was successfully launched on 3 September 2015 and observations were conducted at the solar disc center and close to the limb during the five-minutes flight. In this article, the disc center observations are used to provide an in-flight calibration of the instrument spurious polarization. The derived in-flight spurious polarization is consistent with the spurious polarization levels determined during the pre-flight calibration and a statistical analysis of the polarization fluctuations from solar origin is conducted to ensure a 0.014% precision on the spurious polarization. The combination of the pre-flight and the in-flight polarization calibrations provides a complete picture of the instrument response matrix, and a proper error transfer method is used to confirm the achieved polarization accuracy. As a result, the unprecedented 0.1% polarization accuracy of the instrument in the vacuum ultraviolet is ensured by the polarization calibration.

  4. Uncertainties of atmospheric polarimetric measurements with sun-sky radiometers induced by errors of relative orientations of polarizers

    Science.gov (United States)

    Li, Li; Li, Zhengqiang; Li, Kaitao; Sun, Bin; Wu, Yanke; Xu, Hua; Xie, Yisong; Goloub, Philippe; Wendisch, Manfred

    2018-04-01

    In this study errors of the relative orientations of polarizers in the Cimel polarized sun-sky radiometers are measured and introduced into the Mueller matrix of the instrument. The linearly polarized light with different polarization directions from 0° to 180° (or 360°) is generated by using a rotating linear polarizer in front of an integrating sphere. Through measuring the referential linearly polarized light, the errors of relative orientations of polarizers are determined. The efficiencies of the polarizers are obtained simultaneously. By taking the error of relative orientation into consideration in the Mueller matrix, the accuracies of the calculated Stokes parameters, the degree of linear polarization, and the angle of polarization are remarkably improved. The method may also apply to other polarization instruments of similar types.

  5. The QUIET Instrument

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, C.; et al.

    2012-07-01

    The Q/U Imaging ExperimenT (QUIET) is designed to measure polarization in the Cosmic Microwave Background, targeting the imprint of inflationary gravitational waves at large angular scales ({approx}1{sup o}). Between 2008 October and 2010 December, two independent receiver arrays were deployed sequentially on a 1.4m side-fed Dragonian telescope. The polarimeters which form the focal planes use a highly compact design based on High Electron Mobility Transistors (HEMTs) that provides simultaneous measurements of the Stokes parameters Q, U, and I in a single module. The 17-element Q-band polarimeter array, with a central frequency of 43.1 GHz, has the best sensitivity (69 {mu}Ks{sup 1/2}) and the lowest instrumental systematic errors ever achieved in this band, contributing to the tensor-to-scalar ratio at r < 0:1. The 84-element W-band polarimeter array has a sensitivity of 87 {mu}Ks{sup 1/2} at a central frequency of 94.5 GHz. It has the lowest systematic errors to date, contributing at r < 0:01. The two arrays together cover multipoles in the range {ell} {approx} 25 -- 975. These are the largest HEMT-based arrays deployed to date. This article describes the design, calibration, performance of, and sources of systematic error for the instrument.

  6. Developing Instrumentation for Ground and Balloon-Borne Observing Platforms

    Data.gov (United States)

    National Aeronautics and Space Administration — In my research I will focus on developing hardware and software technology for two instruments searching for polarization in the Cosmic Microwave Background (CMB)....

  7. The Physics of Polarization

    Science.gov (United States)

    Landi Degl'Innocenti, Egidio

    2015-10-01

    The introductory lecture that has been delivered at this Symposium is a condensed version of an extended course held by the author at the XII Canary Island Winter School from November 13 to November 21, 2000. The full series of lectures can be found in Landi Degl'Innocenti (2002). The original reference is organized in 20 Sections that are here itemized: 1. Introduction, 2. Description of polarized radiation, 3. Polarization and optical devices: Jones calculus and Muller matrices, 4. The Fresnel equations, 5. Dichroism and anomalous dispersion, 6. Polarization in everyday life, 7. Polarization due to radiating charges, 8. The linear antenna, 9. Thomson scattering, 10. Rayleigh scattering, 11. A digression on Mie scattering, 12. Bremsstrahlung radiation, 13. Cyclotron radiation, 14. Synchrotron radiation, 15. Polarization in spectral lines, 16. Density matrix and atomic polarization, 17. Radiative transfer and statistical equilibrium equations, 18. The amplification condition in polarized radiative transfer, and 19. Coupling radiative transfer and statistical equilibrium equations.

  8. Polarization properties of real aluminum mirrors; I. Influence of the aluminum oxide layer

    NARCIS (Netherlands)

    van Harten, G.; Snik, F.; Keller, C.U.

    2009-01-01

    In polarimetry, it is important to characterize the polarization properties of the instrument itself to disentangle real astrophysical signals from instrumental effects. This article deals with the accurate measurement and modeling of the polarization properties of real aluminum mirrors, as used in

  9. Luminescence the instrumental key to the future of nanotechnology

    CERN Document Server

    Gilmore, Adam M

    2013-01-01

    PrefaceImportant Spectral and Polarized Properties of Semiconducting SWNT Photoluminescence Shigeo Maruyama and Yuhei MiyauchiImportant Spectral FeaturesPhonon Sideband in AbsorptionVarious Sidebands in EmissionCross-Polarized AbsorptionTransverse Quasi-Dark ExcitonsAdvanced Aspects of Photoluminescence Instrumentation for Carbon Nanotubes Said Kazaoui, Y. Futami, Konstantin Iakoubovskii, and Nobutsugu MinamiIntroductionCNT Thin-Film Fabrication MethodsNIR-PL-Mapping InstrumentsOutlookDevelopments in Catalytic Me

  10. Seismic instrumentation

    International Nuclear Information System (INIS)

    1984-06-01

    RFS or Regles Fondamentales de Surete (Basic Safety Rules) applicable to certain types of nuclear facilities lay down requirements with which compliance, for the type of facilities and within the scope of application covered by the RFS, is considered to be equivalent to compliance with technical French regulatory practice. The object of the RFS is to take advantage of standardization in the field of safety, while allowing for technical progress in that field. They are designed to enable the operating utility and contractors to know the rules pertaining to various subjects which are considered to be acceptable by the Service Central de Surete des Installations Nucleaires, or the SCSIN (Central Department for the Safety of Nuclear Facilities). These RFS should make safety analysis easier and lead to better understanding between experts and individuals concerned with the problems of nuclear safety. The SCSIN reserves the right to modify, when considered necessary, any RFS and specify, if need be, the terms under which a modification is deemed retroactive. The aim of this RFS is to define the type, location and operating conditions for seismic instrumentation needed to determine promptly the seismic response of nuclear power plants features important to safety to permit comparison of such response with that used as the design basis

  11. Venus's southern polar vortex reveals precessing circulation.

    Science.gov (United States)

    Luz, D; Berry, D L; Piccioni, G; Drossart, P; Politi, R; Wilson, C F; Erard, S; Nuccilli, F

    2011-04-29

    Initial images of Venus's south pole by the Venus Express mission have shown the presence of a bright, highly variable vortex, similar to that at the planet's north pole. Using high-resolution infrared measurements of polar winds from the Venus Express Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument, we show the vortex to have a constantly varying internal structure, with a center of rotation displaced from the geographic south pole by ~3 degrees of latitude and that drifts around the pole with a period of 5 to 10 Earth days. This is indicative of a nonsymmetric and varying precession of the polar atmospheric circulation with respect to the planetary axis.

  12. Polarization Measurements on SUMI's TVLS Gratings

    Science.gov (United States)

    Kobayashi, K.; West, E. A.; Davis, J. M.; Gary, G. A.

    2007-01-01

    We present measurements of toroidal variable-line-space (TVLS) gratings for the Solar Ultraviolet Magnetograph Investigation (SUMI), currently being developed at the National Space Science and Technology Center (NSSTC). SUMI is a spectro-polarimeter designed to measure magnetic fields in the solar chromosphere by observing two UV emission lines sensitive to magnetic fields, the CIY line at 155nm and the MgII line at 280nm. The instrument uses a pair of TVLS gratings, to observe both linear polarizations simultaneously. Efficiency measurements were done on bare aluminum gratings and aluminum/MgF2 coated gratings, at both linear polarizations.

  13. Polarization Measurements on SUMI's TVLS Gratings

    Science.gov (United States)

    Kobayashi, K.; West, E. A.; Davis, J. M.; Gary, G. A.

    2007-01-01

    We present measurements of toroidal variable-line-space (TVLS) gratings for the Solar Ultraviolet Magnetograph Investigation (SUMI), currently being developed an the National Space Science and Technology Center (NSSTC). SUMI zs a spectro-polarimeter designed no measure magnetic fields in the solar chromosphere by observing two UV emission lines sensitive to magnetic fields, the C-IV line at 155nm and the Mg-II line at 280nm. The instrument uses a pair of TVLS gratings, to observe both linear polarizations simultaneously. Efficiency measurements were done on bare aluminum gratings and MgF2 coated gratings, at both linear polarizations.

  14. Non-uniform transmission of supermirror devices for neutron polarization

    Energy Technology Data Exchange (ETDEWEB)

    Tong, X., E-mail: tongx@ornl.gov [Instrument and Source Design Division, Oak Ridge National Laboratory, Oak Ridge 37831, TN (United States); Robertson, J.L. [Instrument and Source Design Division, Oak Ridge National Laboratory, Oak Ridge 37831, TN (United States); Pynn, R. [Instrument and Source Design Division, Oak Ridge National Laboratory, Oak Ridge 37831, TN (United States); Indiana University Center for the Exploration of Energy and Matter, Bloomington 47408, IN (United States)

    2014-12-21

    Polarizing supermirrors have been widely used in neutron scattering facilities where they have been employed as neutron spin filters to polarize neutron beams as well as analyze their polarization. In the past, the performance of polarizing supermirrors has been limited by their small acceptance angle, which made them less suitable for use at short wavelengths or with highly divergent beams. Recent advances in supermirror coatings have led to an array of devices designed to, at least partially, overcome this limitation. V-polarizers and multi-channel polarizers have been employed in several different types of neutron scattering instruments. However, our observations in the field where these types of polarizers are in use have raised concerns about their performance. In this paper, we report on detailed Monte-Carlo simulations performed on a multi-channel polarizer used on a prototype Spin-Echo Small Angle Neutron Scattering (SESANS) instrument to better understand its performance. Our results show that careful simulations of polarizers based on mirror reflection are needed to determine whether a particular design is suitable for SESANS applications.

  15. Polarization feedback laser stabilization

    Science.gov (United States)

    Esherick, P.; Owyoung, A.

    1987-09-28

    A system for locking two Nd:YAG laser oscillators includes an optical path for feeding the output of one laser into the other with different polarizations. Elliptical polarization is incorporated into the optical path so that the change in polarization that occurs when the frequencies coincide may be detected to provide a feedback signal to control one laser relative to the other. 4 figs.

  16. Polarization in Sagittarius A*

    OpenAIRE

    Bower, Geoffrey C.

    2000-01-01

    We summarize the current state of polarization observations of Sagittarius A*, the compact radio source and supermassive black hole candidate in the Galactic Center. These observations are providing new tools for understanding accretion disks, jets and their environments. Linear polarization observations have shown that Sgr A* is unpolarized at frequencies as high as 86 GHz. However, recent single-dish observations indicate that Sgr A* may have strong linear polarization at frequencies higher...

  17. Polarization at SLC

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1988-07-01

    The SLAC Linear Collider has been designed to readily accommodate polarized electron beams. Considerable effort has been made to implement a polarized source, a spin rotation system, and a system to monitor the beam polarization. Nearly all major components have been fabricated. At the current time, several source and polarimeter components have been installed. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. It is expected that a beam polarization of 45% will be achieved with no loss in luminosity. 13 refs., 15 figs

  18. Invited Article: Polarization ``Down Under'': The polarized time-of-flight neutron reflectometer PLATYPUS

    Science.gov (United States)

    Saerbeck, T.; Klose, F.; Le Brun, A. P.; Füzi, J.; Brule, A.; Nelson, A.; Holt, S. A.; James, M.

    2012-08-01

    This review presents the implementation and full characterization of the polarization equipment of the time-of-flight neutron reflectometer PLATYPUS at the Australian Nuclear Science and Technology Organisation (ANSTO). The functionality and efficiency of individual components are evaluated and found to maintain a high neutron beam polarization with a maximum of 99.3% through polarizing Fe/Si supermirrors. Neutron spin-flippers with efficiencies of 99.7% give full control over the incident and scattered neutron spin direction over the whole wavelength spectrum available in the instrument. The first scientific experiments illustrate data correction mechanisms for finite polarizations and reveal an extraordinarily high reproducibility for measuring magnetic thin film samples. The setup is now fully commissioned and available for users through the neutron beam proposal system of the Bragg Institute at ANSTO.

  19. IASI instrument: technical description and measured performances

    Science.gov (United States)

    Hébert, Ph.; Blumstein, D.; Buil, C.; Carlier, T.; Chalon, G.; Astruc, P.; Clauss, A.; Siméoni, D.; Tournier, B.

    2017-11-01

    IASI is an infrared atmospheric sounder. It will provide meteorologist and scientific community with atmospheric spectra. The IASI system includes 3 instruments that will be mounted on the Metop satellite series, a data processing software integrated in the EPS (EUMETSAT Polar System) ground segment and a technical expertise centre implemented in CNES Toulouse. The instrument is composed of a Fourier transform spectrometer and an associated infrared imager. The optical configuration is based on a Michelson interferometer and the interferograms are processed by an on-board digital processing subsystem, which performs the inverse Fourier transforms and the radiometric calibration. The infrared imager co-registers the IASI soundings with AVHRR imager (AVHRR is another instrument on the Metop satellite). The presentation will focus on the architectures of the instrument, the description of the implemented technologies and the measured performance of the first flight model. CNES is leading the IASI program in association with EUMETSAT. The instrument Prime is ALCATEL SPACE.

  20. The Primordial Inflation Polarization Explorer (PIPER)

    Science.gov (United States)

    Lazear, Justin Scott; Ade, Peter A.; Benford, Dominic J.; Bennett, Charles L.; Chuss, David T.; Dotson, Jessie L.; Eimer, Joseph R.; Fixsen, Dale J.; Halpern, Mark; Hinderks, James; hide

    2014-01-01

    The Primordial Inflation Polarization ExploreR (Piper) is a balloon-borne cosmic microwave background (CMB) polarimeter designed to search for evidence of inflation by measuring the large-angular scale CMB polarization signal. Bicep2 recently reported a detection of B-mode power corresponding to the tensor-to-scalar ratio r = 0.2 on approximately 2 degree scales. If the Bicep2 signal is caused by inflationary gravitational waves (IGWs), then there should be a corresponding increase in B-mode power on angular scales larger than 18 degrees. Piper is currently the only suborbital instrument capable of fully testing and extending the Bicep2 results by measuring the B-mode power spectrum on angular scales theta ? = approximately 0.6 deg to 90 deg, covering both the reionization bump and recombination peak, with sensitivity to measure the tensor-to-scalar ratio down to r = 0.007, and four frequency bands to distinguish foregrounds. Piper will accomplish this by mapping 85% of the sky in four frequency bands (200, 270, 350, 600 GHz) over a series of 8 conventional balloon flights from the northern and southern hemispheres. The instrument has background-limited sensitivity provided by fully cryogenic (1.5 K) optics focusing the sky signal onto four 32×40-pixel arrays of time-domain multiplexed Transition-Edge Sensor (TES) bolometers held at 140 milli-Kelvin. Polarization sensitivity and systematic control are provided by front-end Variabledelay Polarization Modulators (VPMs), which rapidly modulate only the polarized sky signal at 3 Hz and allow Piper to instantaneously measure the full Stokes vector (I,Q,U,0V) for each pointing. We describe the Piper instrument and progress towards its first flight.

  1. RHIC Polarized proton operation

    International Nuclear Information System (INIS)

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D'Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.E.; Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-01-01

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP 4 . A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above

  2. RHIC Polarized proton operation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D' Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R,; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; J.; Severino, F.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J. Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP{sup 4}. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above

  3. Our Polar Past

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2009-01-01

    The study of polar exploration is fascinating and offers students insights into the history, culture, and politics that affect the developing sciences at the farthest ends of Earth. Therefore, the authors think there is value in incorporating polar exploration accounts within modern science classrooms, and so they conducted research to test their…

  4. Terahertz polarization imaging

    NARCIS (Netherlands)

    Van der Valk, N.C.J.; Van der Marel, W.A.M.; Planken, P.C.M.

    2005-01-01

    We present a new method to measure the polarization state of a terahertz pulse by using a modified electrooptic sampling setup. To illustrate the power of this method, we show two examples in which the knowledge of the polarization of the terahertz pulse is essential for interpreting the results:

  5. Polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

  6. Polar Science Is Cool!

    Science.gov (United States)

    Weeks, Sophie

    2012-01-01

    Children are fascinated by the fact that polar scientists do research in extremely cold and dangerous places. In the Arctic they might be viewed as lunch by a polar bear. In the Antarctic, they could lose toes and fingers to frostbite and the wind is so fast it can rip skin off. They camp on ice in continuous daylight, weeks from any form of…

  7. Precision Polarization of Neutrons

    Science.gov (United States)

    Martin, Elise; Barron-Palos, Libertad; Couture, Aaron; Crawford, Christopher; Chupp, Tim; Danagoulian, Areg; Estes, Mary; Hona, Binita; Jones, Gordon; Klein, Andi; Penttila, Seppo; Sharma, Monisha; Wilburn, Scott

    2009-05-01

    Determining polarization of a cold neutron beam to high precision is required for the next generation neutron decay correlation experiments at the SNS, such as the proposed abBA and PANDA experiments. Precision polarimetry measurements were conducted at Los Alamos National Laboratory with the goal of determining the beam polarization to the level of 10-3 or better. The cold neutrons from FP12 were polarized using optically polarized ^3He gas as a spin filter, which has a highly spin-dependent absorption cross section. A second ^ 3He spin filter was used to analyze the neutron polarization after passing through a resonant RF spin rotator. A discussion of the experiment and results will be given.

  8. Optically polarized 3He

    Science.gov (United States)

    Gentile, T. R.; Nacher, P. J.; Saam, B.; Walker, T. G.

    2018-01-01

    This article reviews the physics and technology of producing large quantities of highly spin-polarized 3He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping. Both technical developments and deeper understanding of the physical processes involved have led to substantial improvements in the capabilities of both methods. For SEOP, the use of spectrally narrowed lasers and K-Rb mixtures has substantially increased the achievable polarization and polarizing rate. For MEOP nearly lossless compression allows for rapid production of polarized 3He and operation in high magnetic fields has likewise significantly increased the pressure at which this method can be performed, and revealed new phenomena. Both methods have benefitted from development of storage methods that allow for spin-relaxation times of hundreds of hours, and specialized precision methods for polarimetry. SEOP and MEOP are now widely applied for spin-polarized targets, neutron spin filters, magnetic resonance imaging, and precision measurements. PMID:29503479

  9. Optically polarized 3He

    Science.gov (United States)

    Gentile, T. R.; Nacher, P. J.; Saam, B.; Walker, T. G.

    2017-10-01

    This article reviews the physics and technology of producing large quantities of highly spin-polarized 3He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping. Both technical developments and deeper understanding of the physical processes involved have led to substantial improvements in the capabilities of both methods. For SEOP, the use of spectrally narrowed lasers and K-Rb mixtures has substantially increased the achievable polarization and polarizing rate. For MEOP nearly lossless compression allows for rapid production of polarized 3He and operation in high magnetic fields has likewise significantly increased the pressure at which this method can be performed, and revealed new phenomena. Both methods have benefitted from development of storage methods that allow for spin-relaxation times of hundreds of hours, and specialized precision methods for polarimetry. SEOP and MEOP are now widely applied for spin-polarized targets, neutron spin filters, magnetic resonance imaging, and precision measurements.

  10. Parallel Polarization State Generation.

    Science.gov (United States)

    She, Alan; Capasso, Federico

    2016-05-17

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security.

  11. OCAPI: a multidirectional multichannel polarizing imager

    Science.gov (United States)

    Le Naour, C.; Eichen, G.; Léon, J. F.

    2017-11-01

    OCAPI (Optical Carbonaceous and anthropogenic Aerosols Pathfinder Instrument) is an imager dedicated to the observation of the spectral, directional and polarized signatures of the solar radiance reflected by the Earth-Atmosphere system. The measurements are used to study air quality and pollution by tracking aerosol quantity, types and circulation at various scales in the visible range. The main characteristics of OCAPI are a 110° along track and cross track field of view, eight polarized channels distributed between 320 and 2130 nm. The resolution is 4 x 4 km2 in the visible and the shortwave infrared (SWIR) range, and 10 x 10 km2 in the UV. The instrumental concept is derived from POLDER and PARASOL with additional channels in the UV and SWIR to better determine aerosol properties and constrain Earth surface and cloud contributions in the detected signal. It is based on three wide field-ofview telecentric optics (UV, Visible and SWIR), a rotating wheel bearing spectral and polarized filters and two dimensional detector arrays at the focal plane of the optics. The instrument requirements, concept and budgets are presented.

  12. In-Situ Polarization Measurements for the Orbiting Carbon Observatory (OCO)

    Science.gov (United States)

    Chu, Victor

    2008-01-01

    The Jet Propulsion Laboratory (JPL) is developing the Orbiting Carbon Observatory (OCO), a polarization-sensitive sensor that will soon be launched. Calibration and validation for this instrument require the ability to account for polarization properties of various surfaces and atmospheres. In order to validate the OCO assumptions, it is necessary to have instrumentation that can measure atmospheric and surface properties. This paper evaluates several instruments that were on hand. Although these instruments were found to be lacking, this study has allowed us to define requirements for future instruments.

  13. The HB-2D Polarized Neutron Development Beamline at the High Flux Isotope Reactor

    Science.gov (United States)

    Crow, Lowell; Hamilton, WA; Zhao, JK; Robertson, JL

    2016-09-01

    The Polarized Neutron Development beamline, recently commissioned at the HB-2D position on the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, provides a tool for development and testing of polarizers, polarized neutron devices, and prototyping of polarized neutron techniques. With available monochromators including pyrolytic graphite and polarizing enriched Fe-57 (Si), the instrument has operated at 4.25 and 2.6 Å wavelengths, using crystal, supermirror, or He-3 polarizers and analyzers in various configurations. The Neutron Optics and Development Team has used the beamline for testing of He-3 polarizers for use at other HFIR and Spallation Neutron Source (SNS) instruments, as well as a variety of flipper devices. Recently, we have acquired new supermirror polarizers which have improved the instrument performance. The team and collaborators also have continuing demonstration experiments of spin-echo focusing techniques, and plans to conduct polarized diffraction measurements. The beamline is also used to support a growing use of polarization techniques at present and future instruments at SNS and HFIR.

  14. Polarization at the SLC

    Energy Technology Data Exchange (ETDEWEB)

    Moffeit, K.C.

    1988-10-01

    The Stanford Linear collider was designed to accommodate polarized electron beams. Longitudinally polarized electrons colliding with unpolarized positrons at a center of mass energy near the Z/sup 0/ mass can be used as novel and sensitive probes of the electroweak process. A gallium arsenide based photon emission source will provide a beam of longitudinally polarized electrons of about 45 percent polarization. A system of bend magnets and a superconducting solenoid will be used to rotate the spins so that the polarization is preserved while the 1.21 GeV electrons are stored in the damping ring. Another set of bend magnets and two superconducting solenoids orient the spin vectors so that longitudinal polarization of the electrons is achieved at the collision point with the unpolarized positrons. A system to monitor the polarization based on Moller and Compton scattering will be used. Nearly all major components have been fabricated and tested. Subsystems of the source and polarimeters have been installed, and studies are in progress. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. 8 refs., 16 figs., 1 tab.

  15. Infrared polar brightenings on Jupiter. V - A thermal equilibrium model for the north polar hot spot

    Science.gov (United States)

    Halthore, Rangasayi; Burrows, Adam; Caldwell, John

    1988-01-01

    Voyager IRIS instrument records of the IR hydrocarbon emissions from Jupiter's north polar region are presently studied to determine the spatial and other characteristics of the north polar hot spot. Attention is given to a thermal equilibrium model that exploits the asymmetry found in 7.8-micron emission of stratospheric methane with respect to system III longitude in order to estimate stratospheric zonal wind velocity. This model accurately predicts the observed asymmetry in acetylene's 13.6-micron emission; this requires, however, enhanced acetylene abundance in the hot spot, as well as ethane depletion. Energetic charged particles are suggested to be the most probable cause of these effects.

  16. Atmospheric Polarization Imaging with Variable Aerosols, Clouds, and Surface Albedo

    Science.gov (United States)

    2013-07-01

    Continuous outdoor operation of an all-sky polarization imager,” Proc. SPIE 7672 (Polarization: Measurement, Analysis , and Remote Sensing IX), 76720A-1-7, 7...condensation nuclei activity and hygroscopicity of in-situ biomass burning aerosol,” American Assoc. Aerosol Research 31 st Annual Conference...tunable liquid crystal variable retarders (LCVRs) allows the API to achieve much faster Stokes-image acquisition than instruments that rely on

  17. Sensitivity of Gamma-Ray Detectors to Polarization

    OpenAIRE

    Yadigaroglu, I. -A.

    1996-01-01

    Previous studies have shown that the largest gamma-ray detector to date, EGRET, does not have useful polarization sensitivity. We have explored here some improved approaches to analyzing gamma-ray pair production events, leading to important gains in sensitivity to polarization. The performance of the next generation gamma-ray instrument GLAST is investigated using a detailed Monte Carlo simulation of the complete detector.

  18. Low activated incore instrument

    Science.gov (United States)

    Ekeroth, D.E.

    1994-04-19

    Instrumentation is described for nuclear reactor head-mounted incore instrumentation systems fabricated of low nuclear cross section materials (i.e., zirconium or titanium). The instrumentation emits less radiation than that fabricated of conventional materials. 9 figures.

  19. Polarized atomic beams for targets

    International Nuclear Information System (INIS)

    Grueebler, W.

    1984-01-01

    The basic principle of the production of polarized atomic hydrogen and deuterium beams are reviewed. The status of the present available polarization, density and intensity are presented. The improvement of atomic beam density by cooling the hydrogen atoms to low velocity is discussed. The possible use of polarized atomic beams as targets in storage rings is shown. It is proposed that polarized atomic beams can be used to produce polarized gas targets with high polarization and greatly improved density

  20. Polarized scintillator targets

    Science.gov (United States)

    van den Brandt, B.; Bunyatova, E. I.; Hautle, P.; Konter, J. A.; Mango, S.

    2000-05-01

    The hydrogen nuclei in an organic scintillator have been polarized to more than 80% and the deuterons in its fully deuterated version to 24%. The scintillator, doped with TEMPO, has been polarized dynamically in a field of 2.5 T in a vertical dilution refrigerator in which a plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat. Sizeable solid samples with acceptable optical properties and light output have been prepared and successfully operated as "live" polarized targets in nuclear physics experiments.

  1. Polarized scintillator targets

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, B. van den E-mail: vandenbrandt@psi.ch; Bunyatova, E.I.; Hautle, P.; Konter, J.A.; Mango, S

    2000-05-21

    The hydrogen nuclei in an organic scintillator have been polarized to more than 80% and the deuterons in its fully deuterated version to 24%. The scintillator, doped with TEMPO, has been polarized dynamically in a field of 2.5 T in a vertical dilution refrigerator in which a plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat. Sizeable solid samples with acceptable optical properties and light output have been prepared and successfully operated as 'live' polarized targets in nuclear physics experiments.

  2. Heidelberg polarized alkali source

    International Nuclear Information System (INIS)

    Kraemer, D.; Steffens, E.; Jaensch, H.; Philipps Universitaet, Marburg, Germany)

    1984-01-01

    A new atomic beam type polarized alkali ion source has been installed at Heidelberg. In order to improve the beam polarization considerably optical pumping is applied in combination with an adiabatic medium field transition which results in beams in single hyperfine sublevels. The m state population is determined by laser-induced fluorescence spectroscopy. Highly polarized beams (P/sub s/ > 0.9, s = z, zz) with intensities of 30 to 130 μA can be extracted for Li + and Na + , respectively

  3. Polarization measurement in the COMPASS polarized target

    CERN Document Server

    Kondo, K; Baum, G; Berglund, P; Doshita, N; Gautheron, F; Görtz, S; Hasegawa, T; Horikawa, N; Ishimoto, S; Iwata, T; Kisselev, Yu V; Koivuniemi, J H; Le Goff, J M; Magnon, A; Meyer, W; Reicherz, G; Matsuda, T

    2004-01-01

    Continuous wave nuclear magnetic resonance (NMR) is used to determine the target polarization in the COMPASS experiment. The system is made of the so-called Liverpool Q-meters, Yale-cards, and VME modules for data taking and system controlling. In 2001 the NMR coils were embedded in the target material, while in 2002 and 2003 the coils were mounted on the outer surface of the target cells to increase the packing factor of the material. Though the error of the measurement became larger with the outer coils than with the inner coils, we have performed stable measurements throughout the COMPASS run time for 3 years. The maximum polarization was +57% and -53% as the average in the target cells.

  4. Evaluating musical instruments

    International Nuclear Information System (INIS)

    Campbell, D. Murray

    2014-01-01

    Scientific measurements of sound generation and radiation by musical instruments are surprisingly hard to correlate with the subtle and complex judgments of instrumental quality made by expert musicians

  5. Evaluating musical instruments

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, D. Murray

    2014-04-01

    Scientific measurements of sound generation and radiation by musical instruments are surprisingly hard to correlate with the subtle and complex judgments of instrumental quality made by expert musicians.

  6. Dynamic nuclear spin polarization

    Energy Technology Data Exchange (ETDEWEB)

    Stuhrmann, H.B. [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

    1996-11-01

    Polarized neutron scattering from dynamic polarized targets has been applied to various hydrogenous materials at different laboratories. In situ structures of macromolecular components have been determined by nuclear spin contrast variation with an unprecedented precision. The experiments of selective nuclear spin depolarisation not only opened a new dimension to structural studies but also revealed phenomena related to propagation of nuclear spin polarization and the interplay of nuclear polarisation with the electronic spin system. The observation of electron spin label dependent nuclear spin polarisation domains by NMR and polarized neutron scattering opens a way to generalize the method of nuclear spin contrast variation and most importantly it avoids precontrasting by specific deuteration. It also likely might tell us more about the mechanism of dynamic nuclear spin polarisation. (author) 4 figs., refs.

  7. Polarized proton colliders

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. This will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. This allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 x 10 32 cm -2 s -1

  8. Tropical echo-top height for precipitating clouds observed by multiple active instruments aboard satellites

    Science.gov (United States)

    Chen, Yilun; Fu, Yunfei

    2018-01-01

    The echo-top height observed by the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) has been used by some studies as an approximate calculation of the precipitating-cloud-top height to simulate radiative forcing or to identify overshooting convection. However, due to the low sensitivity ( 17 dBZ) of PR, the PR-echo-top height is lower than the actual precipitating-cloud-top height. Here, the echo-top heights of the tropical precipitating cloud detected by PR, the Cloud Profiling Radar (CPR), and the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) were investigated to evaluate the underestimation of the PR-echo-top height to the actual precipitating-cloud-top height. The results show that there were significant spatial variations in the underestimates of precipitating-cloud-top height by PR. The model simulation showed that these underestimates led to an underestimation of the radiative forcing of the Earth system, the relative error of which was 10% with 1-km underestimation and 20% to 80% with 7-km underestimation when the cloud optical thickness was fixed to 10. Therefore, the underestimates of precipitating-cloud-top height by PR should be taken into consideration when using PR-echo-top height.

  9. Plasma polarization spectroscopy

    International Nuclear Information System (INIS)

    Iwamae, Atsushi; Horimoto, Yasuhiro; Fujimoto, Takashi; Hasegawa, Noboru; Sukegawa, Kouta; Kawachi, Tetsuya

    2005-01-01

    The electron velocity distribution function (EVDF) in plasma can be anisotropic in laser-produced plasmas. We have developed a new technique to evaluate the polarization degree of the emission lines in the extreme vacuum ultra violet wavelength region. The polarization of the emission lines and the continuums from the lithium-like nitrogen and from helium- and hydrogen-like carbon in recombining plasma is evaluated. Particle simulation in the velocity space gives the time scale for relaxation of anisotropic EVDFs. (author)

  10. Ultracold Polar Molecules

    Science.gov (United States)

    2016-04-01

    AFRL-AFOSR-UK-TR-2016-0005 Ultracold Polar Molecules Jeremy Hutson UNIVERSITY OF DURHAM Final Report 04/01/2016 DISTRIBUTION A: Distribution approved...DATES COVERED (From - To) 15-Jan-2010 to 14-Jul-2015 4. TITLE AND SUBTITLE Final Report on Grant FA8655-10-1-3033 on Ultracold Polar Molecules 5a...formation of ultracold 87RbCs molecules in their rovibrational ground state by magnetoassociation followed by STIRAP, resulting in 14 papers acknowledging

  11. Development of a polarized neutron beam line at Algerian research reactors using McStas software

    Energy Technology Data Exchange (ETDEWEB)

    Makhloufi, M., E-mail: makhloufi_8m@yahoo.fr [Centre de Recherche Nucléaire de Birine (Algeria); Salah, H. [Centre de Recherche Nucléaire d' Alger (Algeria)

    2017-02-01

    Unpolarized instrumentation has long been studied and designed using McStas simulation tool. But, only recently new models were developed for McStas to simulate polarized neutron scattering instruments. In the present contribution, we used McStas software to design a polarized neutron beam line, taking advantage of the available spectrometers reflectometer and diffractometer in Algeria. Both thermal and cold neutron was considered. The polarization was made by two types of supermirrors polarizers FeSi and CoCu provided by the HZB institute. For sake of performance and comparison, the polarizers were characterized and their characteristics reproduced. The simulated instruments are reported. Flipper and electromagnets for guide field are developed. Further developments including analyzers and upgrading of the existing spectrometers are underway. - Highlights: • Permit to evaluate the feasibility of a polarized neutron scattering instrument prior to its implementation. • Help to understand the origin of instrumental imperfections and offer an optimized set up configuration. • Provide the possibility to use the FeSi and CoCu supermirrors, designed to polarize spin up cold neutron, to polarize thermal neutron.

  12. Polarized Light Microscopy

    Science.gov (United States)

    Frandsen, Athela F.

    2016-01-01

    Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often

  13. Latest Progress on the QUBIC Instrument

    Science.gov (United States)

    Ghribi, A.; Aumont, J.; Battistelli, E. S.; Bau, A.; Bélier, B.; Bergé, L.; Bernard, J.-Ph.; Bersanelli, M.; Bigot-Sazy, M.-A.; Bordier, G.; Bunn, E. T.; Cavaliere, F.; Chanial, P.; Coppolecchia, A.; Decourcelle, T.; De Bernardis, P.; De Petris, M.; Drilien, A.-A.; Dumoulin, L.; Falvella, M. C.; Gault, A.; Gervasi, M.; Giard, M.; Gradziel, M.; Grandsire, L.; Gayer, D.; Hamilton, J.-Ch.; Haynes, V.; Giraud-Héraud, Y.; Holtzer, N.; Kaplan, J.; Korotkov, A.; Lande, J.; Lowitz, A.; Maffei, B.; Marnieros, S.; Martino, J.; Masi, S.; Mennella, A.; Montier, L.; Murphy, A.; Ng, M. W.; Olivieri, E.; Pajot, F.; Passerini, A.; Piacentini, F.; Piat, M.; Piccirillo, L.; Pisano, G.; Prêle, D.; Rambaud, D.; Rigaut, O.; Rosset, C.; Salatino, M.; Schillaci, A.; Scully, S.; O'Sullivan, C.; Tartari, A.; Timbie, P.; Tucker, G.; Vibert, L.; Voisin, F.; Watson, B.; Zannoni, M.

    2014-09-01

    QUBIC is a unique instrument that crosses the barriers between classical imaging architectures and interferometry taking advantage from both high sensitivity and systematics mitigation. The scientific target is to detect primordial gravitational waves created by inflation by the polarization they imprint on the cosmic microwave background—the holy grail of modern cosmology. In this paper, we show the latest advances in the development of the architecture and the sub-systems of the first module of this instrument to be deployed at Dome Charlie Concordia base—Antarctica in 2015.

  14. IOT Overview: IR Instruments

    Science.gov (United States)

    Mason, E.

    In this instrument review chapter the calibration plans of ESO IR instruments are presented and briefly reviewed focusing, in particular, on the case of ISAAC, which has been the first IR instrument at VLT and whose calibration plan served as prototype for the coming instruments.

  15. Health physics instrument manual

    International Nuclear Information System (INIS)

    Gupton, E.D.

    1978-08-01

    The purpose of this manual is to provide apprentice health physics surveyors and other operating groups not directly concerned with radiation detection instruments a working knowledge of the radiation detection and measuring instruments in use at the Laboratory. The characteristics and applications of the instruments are given. Portable instruments, stationary instruments, personnel monitoring instruments, sample counters, and miscellaneous instruments are described. Also, information sheets on calibration sources, procedures, and devices are included. Gamma sources, beta sources, alpha sources, neutron sources, special sources, a gamma calibration device for badge dosimeters, and a calibration device for ionization chambers are described

  16. Astronomical Instruments in India

    Science.gov (United States)

    Sarma, Sreeramula Rajeswara

    The earliest astronomical instruments used in India were the gnomon and the water clock. In the early seventh century, Brahmagupta described ten types of instruments, which were adopted by all subsequent writers with minor modifications. Contact with Islamic astronomy in the second millennium AD led to a radical change. Sanskrit texts began to lay emphasis on the importance of observational instruments. Exclusive texts on instruments were composed. Islamic instruments like the astrolabe were adopted and some new types of instruments were developed. Production and use of these traditional instruments continued, along with the cultivation of traditional astronomy, up to the end of the nineteenth century.

  17. The evolution of tensor polarization

    International Nuclear Information System (INIS)

    Huang, H.; Lee, S.Y.; Ratner, L.

    1993-01-01

    By using the equation of motion for the vector polarization, the spin transfer matrix for spin tensor polarization, the spin transfer matrix for spin tensor polarization is derived. The evolution equation for the tensor polarization is studied in the presence of an isolate spin resonance and in the presence of a spin rotor, or snake

  18. HST observations of the limb polarization of Titan

    Science.gov (United States)

    Bazzon, A.; Schmid, H. M.; Buenzli, E.

    2014-12-01

    the hazy atmosphere of Titan. Planets with hazy atmospheres similar to Titan are particularly good candidates for detection with the polarimetric mode of the upcoming planet finder instrument at the VLT. Therefore, a good knowledge of the polarization properties of Titan is also important for the search and investigation of extra-solar planets.

  19. Troubleshooting in nuclear instruments

    International Nuclear Information System (INIS)

    1987-06-01

    This report on troubleshooting of nuclear instruments is the product of several scientists and engineers, who are closely associated with nuclear instrumentation and with the IAEA activities in the field. The text covers the following topics: Preamplifiers, amplifiers, scalers, timers, ratemeters, multichannel analyzers, dedicated instruments, tools, instruments, accessories, components, skills, interfaces, power supplies, preventive maintenance, troubleshooting in systems, radiation detectors. The troubleshooting and repair of instruments is illustrated by some real examples

  20. Beam instrumentation in the AGS Booster

    International Nuclear Information System (INIS)

    Witkover, R.L.

    1991-01-01

    The AGS Booster was designed to accelerate low intensity (2 x 10 10 ) polarized protons, high intensity (1.5x10 13 ) protons and heavy ions through Au +33 . Coping with this wide range of beams, the 3 x 10 -11 Torr vacuum and the radiation environment presented challenges for the beam monitors. Some of the more interesting instrumentation design and performance during the recent Booster proton commissioning will be described

  1. New beam instrumentation in the AGS Booster

    International Nuclear Information System (INIS)

    Witkover, R.L.

    1991-01-01

    The AGS Booster was designed to accelerate beams from 2x10 10 polarized protons to 1.5x10 13 protons and heavy ions through Au +33 . The range of beam parameters and the high vacuum, and radiation environment presented challenges for the beam instrumentation. Some interesting beam monitors in the Booster and transport lines, will be described. Where available, results will be presented. 21 refs., 7 figs

  2. Polarized Electrons at Jefferson Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, C.K.

    1997-12-31

    The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously.initial operational experience with the polarized source will be presented.

  3. Polarized electrons at Jefferson laboratory

    International Nuclear Information System (INIS)

    The CEBAF accelerator at Jefferson laboratory can deliver CW electron beams to three experimental halls simultaneously. A large fraction of the approved scientific program at the lab requires polarized electron beams. Many of these experiments, both polarized and unpolarized, require high average beam current as well. Since all electrons delivered to the experimental halls originate from the same cathode, delivery of polarized beam to a single hall requires using the polarized source to deliver beam to all experiments in simultaneous operation. The polarized source effort at Jefferson Lab is directed at obtaining very long polarized source operational lifetimes at high average current and beam polarization; at developing the capability to deliver all electrons leaving the polarized source to the experimental halls; and at delivering polarized beam to multiple experimental halls simultaneously. Initial operational experience with the polarized source will be presented

  4. Polar low monitoring

    Science.gov (United States)

    Bobylev, Leonid; Zabolotskikh, Elizaveta; Mitnik, Leonid

    2010-05-01

    Polar lows are intense mesoscale atmospheric low pressure weather systems, developing poleward of the main baroclinic zone and associated with high surface wind speeds. Small size and short lifetime, sparse in-situ observations in the regions of their development complicate polar low study. Our knowledge of polar lows and mesocyclones has come almost entirely during the period of satellite remote sensing since, by virtue of their small horizontal scale, it was rarely possible to analyse these lows on conventional weather charts using only the data from the synoptic observing network. However, the effects of intense polar lows have been felt by coastal communities and seafarers since the earliest times. These weather systems are thought to be responsible for the loss of many small vessels over the centuries, although the nature of the storms was not understood and their arrival could not be predicted. The actuality of the polar low research is stipulated by their high destructive power: they are a threat to such businesses as oil and gas exploration, fisheries and shipping. They could worsen because of global warming: a shrinking of sea ice around the North Pole, which thawed to its record minimum in the summer of 2007, is likely to give rise to more powerful storms that form only over open water and can cause hurricane-strength winds. Therefore, study of polar lows, their timely detection, tracking and forecasting represents a challenge for today meteorology. Satellite passive microwave data, starting from Special Sensor Microwave Imager (SSM/I) onboard Defense Meteorological Satellite Program (DMSP) satellite, remain invaluable source of regularly available remotely sensed data to study polar lows. The sounding in this spectral range has several advantages in comparison with observations in visible and infrared ranges and Synthetic Aperture Radar (SAR) data: independence on day time and clouds, regularity and high temporal resolution in Polar Regions. Satellite

  5. Polarized protons at RHIC

    International Nuclear Information System (INIS)

    Tannenbaum, M.J.

    1990-12-01

    The Physics case is presented for the use of polarized protons at RHIC for one or two months each year. This would provide a facility with polarizations of approx-gt 50% high luminosity ∼2.0 x 10 32 cm -2 s -1 , the possibility of both longitudinal and transverse polarization at the interaction regions, and frequent polarization reversal for control of systematic errors. The annual integrated luminosity for such running (∼10 6 sec per year) would be ∫ Ldt = 2 x 10 38 cm -2 -- roughly 20 times the total luminosity integrated in ∼ 10 years of operation of the CERN Collider (∼10 inverse picobarns, 10 37 cm -2 ). This facility would be unique in the ability to perform parity-violating measurements and polarization test of QCD. Also, the existence of p-p collisions in a new energy range would permit the study of ''classical'' reactions like the total cross section and elastic scattering, etc., and serve as a complement to measurements from p-bar p colliders. 11 refs

  6. The Bochum Polarized Target

    International Nuclear Information System (INIS)

    Reicherz, G.; Goertz, S.; Harmsen, J.; Heckmann, J.; Meier, A.; Meyer, W.; Radtke, E.

    2001-01-01

    The Bochum 'Polarized Target' group develops the target material 6 LiD for the COMPASS experiment at CERN. Several different materials like alcohols, alcanes and ammonia are under investigation. Solid State Targets are polarized in magnetic fields higher than B=2.5T and at temperatures below T=1K. For the Dynamic Nuclear Polarization process, paramagnetic centers are induced chemically or by irradiation with ionizing beams. The radical density is a critical factor for optimization of polarization and relaxation times at adequate magnetic fields and temperatures. In a high sensitive EPR--apparatus, an evaporator and a dilution cryostat with a continuous wave NMR--system, the materials are investigated and optimized. To improve the polarization measurement, the Liverpool NMR-box is modified by exchanging the fixed capacitor for a varicap diode which not only makes the tuning very easy but also provides a continuously tuned circuit. The dependence of the signal area upon the circuit current is measured and it is shown that it follows a linear function

  7. In-line Fiber Polarizer

    OpenAIRE

    Perumalsamy, Priya

    1998-01-01

    Polarizers and polarization devices are important components in fiber optic communication and sensor systems. There is a growing need for efficient low loss components that are compatible with optical fibers. An all fiber in-line polarizer is a more desirable alternative that could be placed at appropriate intervals along communication links. An in-line fiber polarizer was fabricated and tested. The in-line fiber polarizer operates by coupling optical energy propagatin...

  8. Political Competition and Polarization

    DEFF Research Database (Denmark)

    Schultz, Christian

    This paper considers political competition and the consequences of political polarization when parties are better informed about how the economy functions than voters are. Specifically, parties know the cost producing a public good, voters do not. An incumbent's choice of policy acts like a signa...... for costs before an upcoming election. It is shown that the more polarized the political parties the more distorted the incumbent's policy choice.......This paper considers political competition and the consequences of political polarization when parties are better informed about how the economy functions than voters are. Specifically, parties know the cost producing a public good, voters do not. An incumbent's choice of policy acts like a signal...

  9. Physics of polarized targets

    CERN Document Server

    Niinikoski, Tapio

    2014-01-01

    For developing, building and operating solid polarized targets we need to understand several fields of physics that have seen sub stantial advances during the last 50 years. W e shall briefly review a selection of those that are important today. These are: 1) quantum statistical methods to describe saturation and relaxation in magnetic resonance; 2) equal spin temperature model for dy namic nuclear polarization; 3 ) weak saturation during NMR polarization measurement; 4 ) refrigeration using the quantum fluid properties of helium isotopes. These, combined with superconducting magnet technologies, permit today to reach nearly complete pola rization of almost any nuclear spins. Targets can be operated in frozen spin mode in rather low and inhomogeneous field of any orientation, and in DNP mode in beams of high intensity. Beyond such experiments of nuclear and particle physics, applications a re also emerging in macromolecular chemistry and in magnetic resonance imaging. This talk is a tribute to Michel Borghini...

  10. No More Polarization, Please!

    DEFF Research Database (Denmark)

    Hansen, Mia Reinholt

    The organizational science literature on motivation has for long been polarized into two main positions; the organizational economic position focusing on extrinsic motivation and the organizational behavior position emphasizing intrinsic motivation. With the rise of the knowledge economy...... and the increasing levels of complexities it entails, such polarization is not fruitful in the attempt to explain motivation of organizational members. This paper claims that a more nuanced perspective on motivation, acknowledging the co-existence of intrinsic and extrinsic motivation, the possible interaction...... between the two as well as different types of motivations filling in the gap between the two polar types, is urgently needed in the organizational science literature. By drawing on the research on intrinsic and extrinsic motivation conducted in social psychology and combining this with contributions from...

  11. Polarized source upgrading

    International Nuclear Information System (INIS)

    Clegg, T.B.; Rummel, R.L.; Carter, E.P.; Westerfeldt, C.R.; Lovette, A.W.; Edwards, S.E.

    1985-01-01

    The decision was made this past year to move the Lamb-shift polarized ion source which was first installed in the laboratory in 1970. The motivation was the need to improve the flexibility of spin-axis orientation by installing the ion source with a new Wien-filter spin precessor which is capable of rotating physically about the beam axis. The move of the polarized source was accomplished in approximately two months, with the accelerator being turned off for experiments during approximately four weeks of this time. The occasion of the move provided the opportunity to rewire completely the entire polarized ion source frame and to rebuild approximately half of the electronic chassis on the source. The result is an ion source which is now logically wired and carefully documented. Beams obtained from the source are much more stable than those previously available

  12. A lunar polar expedition

    Science.gov (United States)

    Dowling, Richard; Staehle, Robert L.; Svitek, Tomas

    1992-09-01

    Advanced exploration and development in harsh environments require mastery of basic human survival skill. Expeditions into the lethal climates of Earth's polar regions offer useful lessons for tommorrow's lunar pioneers. In Arctic and Antarctic exploration, 'wintering over' was a crucial milestone. The ability to establish a supply base and survive months of polar cold and darkness made extensive travel and exploration possible. Because of the possibility of near-constant solar illumination, the lunar polar regions, unlike Earth's may offer the most hospitable site for habitation. The World Space Foundation is examining a scenario for establishing a five-person expeditionary team on the lunar north pole for one year. This paper is a status report on a point design addressing site selection, transportation, power, and life support requirements.

  13. Optical characterization and polarization calibration for rigid endoscopes

    Science.gov (United States)

    Garcia, Missael; Gruev, Viktor

    2017-02-01

    Polarization measurements give orthogonal information to spectral images making them a great tool in the characterization of environmental parameters in nature. Thus, polarization imagery has proven to be remarkably useful in a vast range of biomedical applications. One such application is the early diagnosis of flat cancerous lesions in murine colorectal tumor models, where polarization data complements NIR fluorescence analysis. Advances in nanotechnology have led to compact and precise bio-inspired imaging sensors capable of accurately co-registering multidimensional spectral and polarization information. As more applications emerge for these imagers, the optics used in these instruments get very complex and can potentially compromise the original polarization state of the incident light. Here we present a complete optical and polarization characterization of three rigid endoscopes of size 1.9mm x 10cm (Karl Storz, Germany), 5mm x 30cm, and 10mm x 33cm (Olympus, Germany), used in colonoscopy for the prevention of colitis-associated cancer. Characterization results show that the telescope optics act as retarders and effectively depolarize the linear component. These incorrect readings can cause false-positives or false-negatives leading to an improper diagnosis. In this paper, we offer a polarization calibration scheme for these endoscopes based on Mueller calculus. By modeling the optical properties from training data as real-valued Mueller matrices, we are able to successfully reconstruct the initial polarization state acquired by the imaging system.

  14. POLARIZED NEUTRONS IN RHIC

    Energy Technology Data Exchange (ETDEWEB)

    COURANT,E.D.

    1998-04-27

    There does not appear to be any obvious way to accelerate neutrons, polarized or otherwise, to high energies by themselves. To investigate the behavior of polarized neutrons the authors therefore have to obtain them by accelerating them as components of heavier nuclei, and then sorting out the contribution of the neutrons in the analysis of the reactions produced by the heavy ion beams. The best neutron carriers for this purpose are probably {sup 3}He nuclei and deuterons. A polarized deuteron is primarily a combination of a proton and a neutron with their spins pointing in the same direction; in the {sup 3}He nucleus the spins of the two protons are opposite and the net spin (and magnetic moment) is almost the same as that of a free neutron. Polarized ions other than protons may be accelerated, stored and collided in a ring such as RHIC provided the techniques proposed for polarized proton operation can be adapted (or replaced by other strategies) for these ions. To accelerate polarized particles in a ring, one must make provisions for overcoming the depolarizing resonances that occur at certain energies. These resonances arise when the spin tune (ratio of spin precession frequency to orbit frequency) resonates with a component present in the horizontal field. The horizontal field oscillates with the vertical motion of the particles (due to vertical focusing); its frequency spectrum is dominated by the vertical oscillation frequency and its modulation by the periodic structure of the accelerator ring. In addition, the magnet imperfections that distort the closed orbit vertically contain all integral Fourier harmonics of the orbit frequency.

  15. Mechanisms of Cell Polarity-Controlled Epithelial Homeostasis and Immunity in the Intestine

    NARCIS (Netherlands)

    Klunder, Leon J.; Faber, Klaas Nico; Dijkstra, Gerard; van IJzendoorn, Sven C. D.

    Intestinal epithelial cell polarity is instrumental to maintain epithelial homeostasis and balance communications between the gut lumen and bodily tissue, thereby controlling the defense against gastrointestinal pathogens and maintenance of immune tolerance to commensal bacteria. In this review, we

  16. LRO MOON MINI-RF 5 POLAR MOSAIC CALIBRATED DATA REC V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains lunar polar mosaics composed of calibrated data acquired from the Mini-RF instrument during the LRO mission. The mosaics are made from data...

  17. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the USCGC POLAR SEA in the North Greenland Sea from 1993-07-18 to 1993-08-20 (NODC Accession 0114447)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0114447 includes biological, chemical, discrete sample, physical and profile data collected from USCGC POLAR SEA in the North Greenland Sea from...

  18. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from underway - surface observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from the USCGC POLAR STAR in the Coral Sea, North Pacific Ocean and others from 2001-11-02 to 2002-04-23 (NODC Accession 0108234)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108234 includes chemical, meteorological, physical and underway - surface data collected from USCGC POLAR STAR in the Coral Sea, North Pacific Ocean,...

  19. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the USCGC POLAR SEA in the North Greenland Sea from 1992-07-15 to 1992-08-14 (NODC Accession 0115687)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115687 includes biological, chemical, discrete sample, physical and profile data collected from USCGC POLAR SEA in the North Greenland Sea from...

  20. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from USCGC POLAR SEA in the South Pacific Ocean and Southern Oceans from 1994-02-04 to 1994-02-10 (NODC Accession 0116062)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0116062 includes chemical, discrete sample, physical and profile data collected from USCGC POLAR SEA in the South Pacific Ocean and Southern Oceans...

  1. Dark Polar Dunes

    Science.gov (United States)

    2005-01-01

    20 January 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image, acquired during northern summer in December 2004, shows dark, windblown sand dunes in the north polar region of Mars. A vast sea of sand dunes nearly surrounds the north polar cap. These landforms are located near 80.3oN, 144.1oW. Light-toned features in the image are exposures of the substrate that underlies the dune field. The image covers an area about 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left.

  2. Imaging with Polarized Neutrons

    Directory of Open Access Journals (Sweden)

    Nikolay Kardjilov

    2018-01-01

    Full Text Available Owing to their zero charge, neutrons are able to pass through thick layers of matter (typically several centimeters while being sensitive to magnetic fields due to their intrinsic magnetic moment. Therefore, in addition to the conventional attenuation contrast image, the magnetic field inside and around a sample can be visualized by detecting changes of polarization in a transmitted beam. The method is based on the spatially resolved measurement of the cumulative precession angles of a collimated, polarized, monochromatic neutron beam that traverses a magnetic field or sample.

  3. The polar mesosphere

    International Nuclear Information System (INIS)

    Morris, Ray; Murphy, Damian

    2008-01-01

    The mesosphere region, which lies at the edge of space, contains the coldest layer of the Earth's atmosphere, with summer temperatures as low as minus 130 °C. In this extreme environment ice aerosol layers have appeared since the dawn of industrialization—whose existence may arguably be linked to human influence—on yet another layer of the Earth's fragile atmosphere. Ground-based and space-based experiments conducted in the Arctic and Antarctic during the International Polar Year (IPY) aim to address limitations in our knowledge and to advance our understanding of thermal and dynamical processes at play in the polar mesosphere

  4. Internal polarized targets

    Energy Technology Data Exchange (ETDEWEB)

    Kinney, E.R.; Coulter, K.; Gilman, R.; Holt, R.J.; Kowalczyk, R.S.; Napolitano, J.; Potterveld, D.H.; Young, L. (Argonne National Lab., IL (USA)); Mishnev, S.I.; Nikolenko, D.M.; Popov, S.G.; Rachek, I.A.; Temnykh, A.B.; Toporkov, D.K.; Tsentalovich, E.P.; Wojtsekhowski, B.B. (AN SSSR, Novosibirsk (USSR). Inst. Yadernoj Fiziki)

    1989-01-01

    Internal polarized targets offer a number of advantages over external targets. After a brief review of the basic motivation and principles behind internal polarized targets, the technical aspects of the atomic storage cell will be discussed in particular. Sources of depolarization and the means by which their effects can be ameliorated will be described, especially depolarization by the intense magnetic fields arising from the circulating particle beam. The experience of the Argonne Novosibirsk collaboration with the use of a storage cell in a 2 GeV electron storage ring will be the focus of this technical discussion. 17 refs., 11 figs.

  5. AGS polarized H- source

    International Nuclear Information System (INIS)

    Kponou, A.; Alessi, J.G.; Sluyters, T.

    1985-01-01

    The AGS polarized H - source is now operational. During a month-long experimental physics run in July 1984, pulses equivalent to 15 μA x 300 μs (approx. 3 x 10 10 protons) were injected into the RFQ preaccelerator. Beam polarization, measured at 200 MeV, was approx. 75%. After the run, a program to increase the H - yield of the source was begun and significant progress has been made. The H - current is now frequently 20 to 30 μA. A description of the source and some details of our operating experience are given. We also briefly describe the improvement program

  6. Forward instrumentation for ILC detectors

    International Nuclear Information System (INIS)

    Abramowicz, H; Abusleme, A; Afanaciev, K; Emeliantchik, I; Aguilar, J; Ambalathankandy, P; Fiutowski, T; Bambade, P; Bergholz, M; Castro, E; Grah, C; Bozovic-Jelisavcic, I; Chelkov, G; Gostkin, M; Coca, C; Dumitru, L; Daniluk, W; Grzelak, G; Dragone, A; Elsener, K

    2010-01-01

    Two special calorimeters are foreseen for the instrumentation of the very forward region of the ILC detector, a luminometer designed to measure the rate of low angle Bhabha scattering events with a precision better than 10 -3 and a low polar angle calorimeter, adjacent to the beam-pipe. The latter will be hit by a large amount of beamstrahlung remnants. The amount and shape of these depositions will allow a fast luminosity estimate and the determination of beam parameters. The sensors of this calorimeter must be radiation hard. Both devices will improve the hermeticity of the detector in the search for new particles. Finely segmented and very compact calorimeters will match the requirements. Due to the high occupancy fast front-end electronics is needed. The design of the calorimeters developed and optimised with Monte Carlo simulations is presented. Sensors and readout electronics ASICs have been designed and prototypes are available. Results on the performance of these major components are summarised.

  7. Forward instrumentation for ILC detectors

    International Nuclear Information System (INIS)

    Abramowicz, Halina; Abusleme, Angel; Afanaciev, Konstantin

    2010-09-01

    Two special calorimeters are foreseen for the instrumentation of the very forward region of the ILC detector, a luminometer designed to measure the rate of low angle Bhabha scattering events with a precision better than 10 -3 and a low polar angle calorimeter, adjacent to the beam-pipe. The latter will be hit by a large amount of beamstrahlung remnants. The amount and shape of these depositions will allow a fast luminosity estimate and the determination of beam parameters. The sensors of this calorimeter must be radiation hard. Both devices will improve the hermeticity of the detector in the search for new particles. Finely segmented and very compact calorimeters will match the requirements. Due to the high occupancy fast front-end electronics is needed. The design of the calorimeters developed and optimised with Monte Carlo simulations is presented. Sensors and readout electronics ASICs have been designed and prototypes are available. Results on the performance of these major components are summarised. (orig.)

  8. The physics of polarization

    Science.gov (United States)

    Landi Degl'Innocenti, Egidio

    This course is intended to give a description of the basic physical concepts which underlie the study and the interpretation of polarization phenomena. Apart from a brief historical introduction (Sect. 1), the course is organized in three parts. A first part (Sects. 2 - 6) covers the most relevant facts about the polarization phenomena that are typically encountered in laboratory applications and in everyday life. In Sect. 2, the modern description of polarization in terms of the Stokes parameters is recalled, whereas Sect. 3 is devoted to introduce the basic tools of laboratory polarimetry, such as the Jones calculus and the Mueller matrices. The polarization phenomena which are met in the reflection and refraction of a beam of radiation at the separation surface between two dielectrics, or between a dielectric and a metal, are recalled in Sect. 4. Finally, Sect. 5 gives an introduction to the phenomena of dichroism and of anomalous dispersion and Sect. 6 summarizes the polarization phenomena that are commonly encountered in everyday life. The second part of this course (Sects. 7-14) deals with the description, within the formalism of classical physics, of the spectro-polarimetric properties of the radiation emitted by accelerated charges. Such properties are derived by taking as starting point the Liénard and Wiechert equations that are recalled and discussed in Sect. 7 both in the general case and in the non-relativistic approximation. The results are developed to find the percentage polarization, the radiation diagram, the cross-section and the spectral characteristics of the radiation emitted in different phenomena particularly relevant from the astrophysical point of view. The emission of a linear antenna is derived in Sect. 8. The other Sections are devoted to Thomson scattering (Sect. 9), Rayleigh scattering (Sect. 10), Mie scattering (Sect. 11), bremsstrahlung radiation (Sect. 12), cyclotron radiation (Sect. 13), and synchrotron radiation (Sect. 14

  9. Full-Stokes polarimetry with circularly polarized feeds. Sources with stable linear and circular polarization in the GHz regime

    Science.gov (United States)

    Myserlis, I.; Angelakis, E.; Kraus, A.; Liontas, C. A.; Marchili, N.; Aller, M. F.; Aller, H. D.; Karamanavis, V.; Fuhrmann, L.; Krichbaum, T. P.; Zensus, J. A.

    2018-01-01

    We present an analysis pipeline that enables the recovery of reliable information for all four Stokes parameters with high accuracy. Its novelty relies on the effective treatment of the instrumental effects even before the computation of the Stokes parameters, contrary to conventionally used methods such as that based on the Müller matrix. For instance, instrumental linear polarization is corrected across the whole telescope beam and significant Stokes Q and U can be recovered even when the recorded signals are severely corrupted by instrumental effects. The accuracy we reach in terms of polarization degree is of the order of 0.1-0.2%. The polarization angles are determined with an accuracy of almost 1°. The presented methodology was applied to recover the linear and circular polarization of around 150 active galactic nuclei, which were monitored between July 2010 and April 2016 with the Effelsberg 100-m telescope at 4.85 GHz and 8.35 GHz with a median cadence of 1.2 months. The polarized emission of the Moon was used to calibrate the polarization angle measurements. Our analysis showed a small system-induced rotation of about 1° at both observing frequencies. Over the examined period, five sources have significant and stable linear polarization; three sources remain constantly linearly unpolarized; and a total of 11 sources have stable circular polarization degree mc, four of them with non-zero mc. We also identify eight sources that maintain a stable polarization angle. All this is provided to the community for future polarization observations reference. We finally show that our analysis method is conceptually different from those traditionally used and performs better than the Müller matrix method. Although it has been developed for a system equipped with circularly polarized feeds, it can easily be generalized to systems with linearly polarized feeds as well. The data used to create Fig. C.1 are only available at the CDS via anonymous ftp to http

  10. Polarized Proton Collisions at RHIC

    CERN Document Server

    Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

    2005-01-01

    The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...

  11. Comparative Effects of Tri-Polar Eclectic Teaching Approach on ...

    African Journals Online (AJOL)

    FIRST LADY

    Abstract. This is an experimental study that examined the comparative effects of Tri- polar Interactionist teaching strategy on the academic performance of Junior. Secondary School III students of Adeyemi Demonstration secondary School. Ondo in social studies. The instrument used for the study includes scheme of.

  12. A Fuzzy Computing Model for Identifying Polarity of Chinese Sentiment Words

    OpenAIRE

    Wang, Bingkun; Huang, Yongfeng; Wu, Xian; Li, Xing

    2015-01-01

    With the spurt of online user-generated contents on web, sentiment analysis has become a very active research issue in data mining and natural language processing. As the most important indicator of sentiment, sentiment words which convey positive and negative polarity are quite instrumental for sentiment analysis. However, most of the existing methods for identifying polarity of sentiment words only consider the positive and negative polarity by the Cantor set, and no attention is paid to th...

  13. Scientific Research in Polar Seas – ERICON Science Perspective 2015-2030

    NARCIS (Netherlands)

    Wilmott, V.; Azzolini, R.; von Brandt, A.; Brinkhuis, H.; Camerlenghi, A.; Coakley, B.; De Santis, L.; Kristoffersen, Y.; Lembke-Jene, L.; Rebesco, M.; Thiede, J.; and other contributors, .

    2012-01-01

    Polar sciences are a modern branch of the natural sciences involving large groups of researchers, and sophisticated instrumentation contributing indispensable data for a better understanding of the polar regions and their impact on the global environment. The fact that a lot of the necessary

  14. Lobbying and political polarization

    OpenAIRE

    Ursprung, Heinrich W.

    2002-01-01

    Standard spatial models of political competition give rise to equilibria in which the competing political parties or candidates converge to a common position. In this paper I show how political polarization can be generated in models that focus on the nexus between pre-election interest group lobbying and electoral competition.

  15. Fluorescence confocal polarizing microscopy

    Indian Academy of Sciences (India)

    Much of the modern understanding of orientational order in liquid crystals (LCs) is based on polarizing microscopy (PM). A PM image bears only two-dimensional (2D) information, integrating the 3D pattern of optical birefringence over the path of light. Recently, we proposed a technique to image 3D director patterns by ...

  16. Polarization of Bremsstrahlung

    International Nuclear Information System (INIS)

    Miller, J.

    1957-01-01

    The numerical results for the polarization of Bremsstrahlung are presented. The multiple scattering of electrons in the target is taken into account. The angular-and photon energy dependences are seen on the curves for an incident 25 MeV electron energy. (Author) [fr

  17. DESY: HERA polarization

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The new HERA electron-proton collider at DESY in Hamburg achieved the first luminosity for electron-proton collisions on 19 October last year. Only one month later, on 20 November, HERA passed another important milestone with the observation of transverse electron polarization

  18. Titan Polar Landscape Evolution

    Science.gov (United States)

    Moore, Jeffrey M.

    2016-01-01

    With the ongoing Cassini-era observations and studies of Titan it is clear that the intensity and distribution of surface processes (particularly fluvial erosion by methane and Aeolian transport) has changed through time. Currently however, alternate hypotheses substantially differ among specific scenarios with respect to the effects of atmospheric evolution, seasonal changes, and endogenic processes. We have studied the evolution of Titan's polar region through a combination of analysis of imaging, elevation data, and geomorphic mapping, spatially explicit simulations of landform evolution, and quantitative comparison of the simulated landscapes with corresponding Titan morphology. We have quantitatively evaluated alternate scenarios for the landform evolution of Titan's polar terrain. The investigations have been guided by recent geomorphic mapping and topographic characterization of the polar regions that are used to frame hypotheses of process interactions, which have been evaluated using simulation modeling. Topographic information about Titan's polar region is be based on SAR-Topography and altimetry archived on PDS, SAR-based stereo radar-grammetry, radar-sounding lake depth measurements, and superposition relationships between geomorphologic map units, which we will use to create a generalized topographic map.

  19. Graphics of polar figure

    International Nuclear Information System (INIS)

    Macias B, L.R.

    1991-11-01

    The objective of this work, is that starting from a data file coming from a spectra that has been softened, and of the one that have been generated its coordinates to project it in stereographic form, to create the corresponding polar figure making use of the Cyber computer of the ININ by means of the GRAPHOS package. This work only requires a Beta, Fi and Intensity (I) enter data file. It starts of the existence of a softened spectra of which have been generated already with these data, making use of some language that in this case was FORTRAN for the Cyber computer, a program is generated supported in the Graphos package that allows starting of a reading of the Beta, Fi, I file, to generate the points in a stereographic projection and that it culminates with the graph of the corresponding polar figure. The program will request the pertinent information that is wanted to capture in the polar figure just as: date, name of the enter file, indexes of the polar figure, number of levels, radio of the stereographic projection (cms.), crystalline system to which belongs the sample, name the neuter graph file by create and to add the own general data. (Author)

  20. Research reactor instrumentation

    International Nuclear Information System (INIS)

    Boeck, H.; Villa, M.

    2001-02-01

    This is a textbook on research reactor instrumentation for training purposes, it gives a survey on research reactor instrumentation requirements and eight exercises covering the major aspects of this topic are presented. (author)

  1. Performing the Super Instrument

    DEFF Research Database (Denmark)

    Kallionpaa, Maria

    2016-01-01

    The genre of contemporary classical music has seen significant innovation and research related to new super, hyper, and hybrid instruments, which opens up a vast palette of expressive potential. An increasing number of composers, performers, instrument designers, engineers, and computer programmers...... provides the performer extensive virtuoso capabilities in terms of instrumental range, harmony, timbre, or spatial, textural, acoustic, technical, or technological qualities. The discussion will be illustrated by a composition case study involving augmented musical instrument electromagnetic resonator...

  2. Instrument Modeling and Synthesis

    Science.gov (United States)

    Horner, Andrew B.; Beauchamp, James W.

    During the 1970s and 1980s, before synthesizers based on direct sampling of musical sounds became popular, replicating musical instruments using frequency modulation (FM) or wavetable synthesis was one of the “holy grails” of music synthesis. Synthesizers such as the Yamaha DX7 allowed users great flexibility in mixing and matching sounds, but were notoriously difficult to coerce into producing sounds like those of a given instrument. Instrument design wizards practiced the mysteries of FM instrument design.

  3. Discussion on data correction for Polarization Analysis with a 3He spin filter analyzer

    Science.gov (United States)

    Babcock, Earl; Salhi, Zahir; Kentzinger, Emmanuel; Mattauch, Stefan; Ioffe, Alexander

    2017-06-01

    Fully polarized neutron reflectometry and grazing incidence small angle neutron scattering are effective methods to explore magnetic structures on the nm to μm length scales. This paper is an outline of how to fully correct for the polarization analysis (PA) inefficiencies of such an instrument and to determine the error contributions of the neutron polarizer and analyzer. This discussion considers the exact case of the polarization analysis instrumentation used on the MARIA neutron reflectometer at the MLZ or for a general polarized neutron scattering instrument using at least one 3He neutron spin filter that has the capability for adiabatic fast passage nuclear magnetic resonance flipping of the 3He polarization. This paper will work to build a conceptual understanding of how the inefficiencies of neutron polarization elements affect measured data in order to stress and encourage the application of PA corrections and to help perform successful measurements. Then, using data from a fully polarized neutron reflectometer test measurement we show how it is possible to recover signals on the order of, or even smaller than, the inefficiencies, or bleed-through, of the neutron polarization devices used.

  4. An Imaging Polar Nephelometer

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This invention relates to measuring the light that is scattered from particulates (aerosols) in a gas or liquid. The sample typically flows into the instrument and...

  5. Characteristics of volume polarization holography with linear polarization light

    Science.gov (United States)

    Zang, Jinliang; Wu, An'an; Liu, Ying; Wang, Jue; Lin, Xiao; Tan, Xiaodi; Shimura, Tsutomu; Kuroda, Kazuo

    2015-10-01

    Volume polarization holographic recording in phenanthrenequinone-doped poly(methyl methacrylate) (PQ-PMMA) photopolymer with linear polarized light is obtained. The characteristics of the volume polarization hologram are experimentally investigated. It is found that beyond the paraxial approximation the polarization states of the holographic reconstruction light are generally different from the signal light. Based on vector wave theoretical analyses and material properties, the special exposure condition for correctly holographic reconstruction is obtained and experimentally demonstrated.

  6. Aeroacoustics of Musical Instruments

    NARCIS (Netherlands)

    Fabre, B.; Gilbert, J.; Hirschberg, Abraham; Pelorson, X.

    2012-01-01

    We are interested in the quality of sound produced by musical instruments and their playability. In wind instruments, a hydrodynamic source of sound is coupled to an acoustic resonator. Linear acoustics can predict the pitch of an instrument. This can significantly reduce the trial-and-error process

  7. GUPPI: Green Bank Ultimate Pulsar Processing Instrument

    Science.gov (United States)

    Ransom, Scott M.; Demorest, P.; Ford, J.; McCullough, R.; Ray, J.; DuPlain, R.; Brandt, P.

    2009-12-01

    The high precision radio pulsar timing required for gravitational wave detection experiments (like NANOGrav) and gravitational theory or neutron star equation-of-state tests demands that pulse phase be measured to precisions of 0.01% of the pulse period, or tens to hundreds of nano-seconds for millisecond pulsars (MSPs). This requirement means high precision instrumentation. At NRAO we are developing a state-of-the-art pulsar backend called GUPPI for these scientific problems. GUPPI provides wide bandwidth (up to 800 MHz), high dynamic range (8-bit sampling), substantially improved interference resistance (compared to all other GBT pulsar instruments), and full polarization capabilities. Currently it is being commissioned as a fully supported facility instrument for the GBT in a digital filterbank (i.e. incoherent dedispersion) mode. Within the next six months full coherent dedispersion capabilities are planned.

  8. Experiments with Fermilab polarized proton and polarized antiproton beams

    International Nuclear Information System (INIS)

    Yokosawa, A.

    1990-01-01

    We summarize activities concerning the Fermilab polarized beams. They include a brief description of the polarized-beam facility, measurements of beam polarization by polarimeters, asymmetry measurements in the π degree production at high p perpendicular and in the Λ (Σ degree), π ± , π degree production at large x F , and Δσ L (pp, bar pp) measurements. 18 refs

  9. NUCLEON POLARIZATION IN 3-BODY MODELS OF POLARIZED LI-6

    NARCIS (Netherlands)

    SCHELLINGERHOUT, NW; KOK, LP; COON, SA; ADAM, RM

    1993-01-01

    Just as He-3 --> can be approximately characterized as a polarized neutron target, polarized Li-6D has been advocated as a good isoscalar nuclear target for the extraction of the polarized gluon content of the nucleon. The original argument rests upon a presumed ''alpha + deuteron'' picture of Li-6,

  10. Cloud and Aerosol 1064nm Lidar Ratio Retrievals from the CATS Instrument

    Science.gov (United States)

    Pauly, R.; Yorks, J. E.; McGill, M. J.; Hlavka, D. L.; Midzak, N.

    2017-12-01

    The extinction to backscatter ratio or lidar ratio is an essential value in order to derive the optical properties of cloud and aerosol layers from standard elastic backscatter lidar data. For these instruments, the lidar ratio can sometimes be determined from lidar data utilizing the transmission loss or "constrained" technique. The best situations for deploying this technique involve clearly defined layers with clear sky underneath for 1-3 km. In situations where the lidar ratio cannot be calculated, look-up tables exist for various cloud and aerosol types. There is a vast data record of derived lidar ratios for various cloud and aerosol types using 532nm from an array of instruments (i.e. HSRL, CALIOP, CPL, Aeronet, MPLNET). To date, because the 1064nm molecular signal is so small, lidar ratios at 1064nm have been mostly determined from 532nm lidar ratios using angstrom exponents, color ratios and ground based non-lidar measurements, as HSRL measurements at that wavelength do not exist. Due to the better signal quality at 1064nm compared to the 532nm signal, the CATS laser was thermally tuned to increase the 1064nm output energy. Therefore, the 1064nm channel is used in nearly all CATS layer data processing, making the accurate determination of 1064nm lidar ratio imperative. The CATS 1064nm signal allows for the unique capability to determine 1064nm lidar ratios better than previous instruments. The statistical and case study results of the CATS derived smoke and dust lidar ratios will be presented. Results have shown that the previously assumed 1064nm lidar ratios for dust need to be lowered. In addition to 1064nm lidar ratio results from the traditional transmission loss technique, results for aerosol layers above opaque water clouds from a method utilizing the depolarization ratio of the opaque cloud will be discussed. Incorporating this method into the CATS algorithms should increase the number of aerosol layers with constrained lidar ratio.

  11. Optimization of a solid state polarizing bender for cold neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Shah, V.R.; Washington, A.L.; Stonaha, P.; Ashkar, R.; Kaiser, H. [Center for the Exploration of Energy and Matter, Indiana University, Bloomington IN (United States); Krist, T. [Helmholtz Zentrum Berlin, 14109 Berlin (Germany); Pynn, Roger [Center for the Exploration of Energy and Matter, Indiana University, Bloomington IN (United States); Neutron Science Directorate, Oak Ridge National Laboratory, Oak Ridge TN (United States)

    2014-12-21

    We have designed a solid state bender to polarize cold neutrons for the Spin Echo Scattering Angle Measurement (SESAME) instrument at the Low Energy Neutron Source (LENS) at Indiana University. The design attempts to achieve high neutron polarization across a wide range of neutron wavelengths and divergence angles by optimizing the supermirror coating materials. The transmission and polarizing efficiency of the bender were modeled using the VITESS software, then measured at both continuous-wave and pulsed neutron sources. While the measured peak neutron transmission and polarization agree reasonably well with simulations, neither quantity has been successfully modeled for long wavelength neutrons. These results imply an insufficient understanding of the magnetic microstructure of the supermirror coatings used.

  12. Geomagnetic polarity transitions

    Science.gov (United States)

    Merrill, Ronald T.; McFadden, Phillip L.

    1999-05-01

    The top of Earth's liquid outer core is nearly 2900 km beneath Earth's surface, so we will never be able to observe it directly. This hot, dense, molten iron-rich body is continuously in motion and is the source of Earth's magnetic field. One of the most dynamic manifestations at Earth's surface of this fluid body is, perhaps, a reversal of the geomagnetic field. Unfortunately, the most recent polarity transition occurred at about 780 ka, so we have never observed a transition directly. It seems that a polarity transition spans many human lifetimes, so no human will ever witness the phenomenon in its entirety. Thus we are left with the tantalizing prospect that paleomagnetic records of polarity transitions may betray some of the secrets of the deep Earth. Certainly, if there are systematics in the reversal process and they can be documented, then this will reveal substantial information about the nature of the lowermost mantle and of the outer core. Despite their slowness on a human timescale, polarity transitions occur almost instantaneously on a geological timescale. This rapidity, together with limitations in the paleomagnetic recording process, prohibits a comprehensive description of any reversal transition both now and into the foreseeable future, which limits the questions that may at this stage be sensibly asked. The natural model for the geomagnetic field is a set of spherical harmonic components, and we are not able to obtain a reliable model for even the first few harmonic terms during a transition. Nevertheless, it is possible, in principle, to make statements about the harmonic character of a geomagnetic polarity transition without having a rigorous spherical harmonic description of one. For example, harmonic descriptions of recent geomagnetic polarity transitions that are purely zonal can be ruled out (a zonal harmonic does not change along a line of latitude). Gleaning information about transitions has proven to be difficult, but it does seem

  13. Polarized electron beams at SLAC

    International Nuclear Information System (INIS)

    Moffeit, K.C.

    1992-11-01

    SLAC has successfully accelerated high energy polarized electrons for the Stanford Linear Collider and fixed polarized nuclear target experiments. The polarized electron beams at SLAC use a gallium arsenide (GaAlAs for E-142) photon emission source to provide the beam of polarized electrons with polarization of approximately 28% (41% for E-142). While the beam emittance is reduced in the damping ring for SLC operation a system of bend magnets and superconducting solenoids preserve and orient the spin direction for maximum longitudinal polarization at the collision point. The electron polarization is monitored with a Compton scattering polarimeter, and was typically 22% at the e+e- collision point for the 1992 run. Improvements are discussed to increase the source polarization and to reduce the depolarization effects between the source and the collision point

  14. Analytical polarization calculations beyond SLIM

    International Nuclear Information System (INIS)

    Barber, D.P.

    1989-01-01

    A comparison is made between the theories of Bell and Leinaas and of Derbenev and Kondratenko for the spin polarization in electron storage rings. A calculation of polarization in HERA using the program SMILE of Mane is presented

  15. Recent progress on HYSPEC, and its polarization analysis capabilities

    Directory of Open Access Journals (Sweden)

    Winn Barry

    2015-01-01

    Full Text Available HYSPEC is a high-intensity, direct-geometry time-of-flight spectrometer at the Spallation Neutron Source, optimized for measurement of excitations in small single-crystal specimens with optional polarization analysis capabilities. The incident neutron beam is monochromated using a Fermi chopper with short, straight blades, and is then vertically focused by Bragg scattering onto the sample position by either a highly oriented pyrolitic graphite (unpolarized or a Heusler (polarized crystal array. Neutrons are detected by a bank of 3He tubes that can be positioned over a wide range of scattering angles about the sample axis. HYSPEC entered the user program in February 2013 for unpolarized experiments, and is already experiencing a vibrant research program. Polarization analysis will be accomplished by using the Heusler crystal array to polarize the incident beam, and either a 3He spin filter or a supermirror wide-angle polarization analyser to analyse the scattered beam. The 3He spin filter employs the spin-exchange optical pumping technique. A 60∘ wide angle 3He cell that matches the detector coverage will be used for polarization analysis. The polarized gas in the post-sample wide angle cell is designed to be periodically and automatically refreshed with an adjustable pressure of polarized gas, optically pumped in a separate cell and then transferred to the wide angle cell. The supermirror analyser has 960 supermirror polarizers distributed over 60∘, and has been characterized at the Swiss Spallation Neutron Source. The current status of the instrument and the development of its polarization analysis capabilities are presented.

  16. On Determinants of Political Polarization

    OpenAIRE

    Grechyna, Daryna

    2015-01-01

    Political polarization has been shown to significantly influence a country's economic performance. However, little is known about the drivers of political polarization. In this article, we aim to identify the main determinants of political polarization using Bayesian Model Averaging to overcome the problem of model uncertainty. We find that the level of trust within a country and the degree of income inequality are the most robust determinants of political polarization.

  17. Modulus design multiwavelength polarization microscope for transmission Mueller matrix imaging.

    Science.gov (United States)

    Zhou, Jialing; He, Honghui; Chen, Zhenhua; Wang, Ye; Ma, Hui

    2018-01-01

    We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  18. Polarized electrogowdy spacetimes censored

    Energy Technology Data Exchange (ETDEWEB)

    Nungesser, Ernesto, E-mail: ernesto.nungesser@aei.mpg.d [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Am Muehlenberg 1, 14476 Potsdam (Germany)

    2010-05-01

    A sketch of the proof of strong cosmic censorship is presented for a class of solutions of the Einstein-Maxwell equations, those with polarized Gowdy symmetry. A key element of the argument is the observation that by means of a suitable choice of variables the central equations in this problem can be written in a form where they are identical to the central equations for general (i.e. non-polarized) vacuum Gowdy spacetimes. Using this it is seen that the results of Ringstroem on strong cosmic censorship in the vacuum case have implications for the Einstein-Maxwell case. Working out the geometrical meaning of these analytical results leads to the main conclusion.

  19. PEPPo: Using a Polarized Electron Beam to Produce Polarized Positrons

    Energy Technology Data Exchange (ETDEWEB)

    Adeyemi, Adeleke H. [Hampton Univ., Hampton, VA (United States); et al.

    2015-09-01

    Polarized positron beams have been identified as either an essential or a significant ingredient for the experimental program of both the present and next generation of lepton accelerators (JLab, Super KEK B, ILC, CLIC). An experiment demonstrating a new method for producing polarized positrons has been performed at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e⁻/e⁺ pairs from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a high-Z conversion target. PEPPo demonstrated the effective transfer of spin-polarization of an 8.2 MeV/c polarized (P~85%) electron beam to positrons produced in varying thickness tungsten production targets, and collected and measured in the range of 3.1 to 6.2 MeV/c. In comparison to other methods this technique reveals a new pathway for producing either high-energy or thermal polarized positron beams using a relatively low polarized electron beam energy (~10MeV) .This presentation will describe the PEPPo concept, the motivations of the experiment and high positron polarization achieved.

  20. Polarization induced doped transistor

    Science.gov (United States)

    Xing, Huili; Jena, Debdeep; Nomoto, Kazuki; Song, Bo; Zhu, Mingda; Hu, Zongyang

    2016-06-07

    A nitride-based field effect transistor (FET) comprises a compositionally graded and polarization induced doped p-layer underlying at least one gate contact and a compositionally graded and doped n-channel underlying a source contact. The n-channel is converted from the p-layer to the n-channel by ion implantation, a buffer underlies the doped p-layer and the n-channel, and a drain underlies the buffer.

  1. Polar bears, Ursus maritimus

    Science.gov (United States)

    Rode, Karyn D.; Stirling, Ian

    2017-01-01

    Polar bears are the largest of the eight species of bears found worldwide and are covered in a pigment-free fur giving them the appearance of being white. They are the most carnivorous of bear species consuming a high-fat diet, primarily of ice-associated seals and other marine mammals. They range throughout the circumpolar Arctic to the southernmost extent of seasonal pack ice.

  2. Polarized advanced fuel reactors

    International Nuclear Information System (INIS)

    Kulsrud, R.M.

    1987-07-01

    The d- 3 He reaction has the same spin dependence as the d-t reaction. It produces no neutrons, so that if the d-d reactivity could be reduced, it would lead to a neutron-lean reactor. The current understanding of the possible suppression of the d-d reactivity by spin polarization is discussed. The question as to whether a suppression is possible is still unresolved. Other advanced fuel reactions are briefly discussed. 11 refs

  3. On polarization in biomembranes

    DEFF Research Database (Denmark)

    Zecchi, Karis Amata

    close to physiological conditions, making these effects biologically relevant. In this work, we consider the case of asymmetric membranes which can display spontaneous polarization in the absence of a field. Close to the phase transition, we find that the membrane displays piezoelectric, flexoelectric...... on different geometries point in the direction of a flexoelectric mechanism behind current rectification in lipid bilayers. Finally, we suggest that our updated equivalent circuit should be included in the interpretation of elctrophysiological data....

  4. Multifrequency Behaviour of Polars

    Directory of Open Access Journals (Sweden)

    K. Reinsch

    2015-02-01

    Full Text Available Cataclysmic variables emit over a wide range of the electromagnetic spectrum. In this paper I will review observations of polars in relevant passbands obtained during the last decade and will discuss their diagnostical potential to access the physics of the main components within the binary systems. This will include a discussion of intrinsic source variability and the quest for simultaneous multi-frequency observations.

  5. Polar Business Design

    Directory of Open Access Journals (Sweden)

    Sébastien Caisse

    2014-02-01

    Full Text Available Polar business design aims to enable entrepreneurs, managers, consultants, researchers, and business students to better tackle model-based analysis, creation, and transformation of businesses, ventures, and, more generically, collective endeavors of any size and purpose. It is based on a systems-thinking approach that builds on a few interrelated core concepts to create holistic visual frameworks. These core concepts act as poles linked by meaningful dyads, flows, and faces arranged in geometric shapes. The article presents two such polar frameworks as key findings in an ongoing analytic autoethnography: the three-pole Value−Activity−Stakeholder (VAS triquetra and the four-pole Offer−Creation−Character−Stakeholder (OCCS tetrahedron. The VAS triquetra is a more aggregated model of collective endeavors. The OCCS tetrahedron makes a trade-off between a steeper learning curve and deeper, richer representation potential. This article discusses how to use these two frameworks as well as their limits, and explores the potential that polar business design offers for future research.

  6. Joint Polar Satellite System: The United States next generation civilian polar-orbiting environmental satellite system

    Science.gov (United States)

    Goldberg, Mitchell D.; Kilcoyne, Heather; Cikanek, Harry; Mehta, Ajay

    2013-12-01

    next generation polar-orbiting environmental satellite system, designated as the Joint Polar Satellite System (JPSS), was proposed in February 2010, as part of the President's Fiscal Year 2011 budget request, to be the Civilian successor to the restructured National Polar-Orbiting Operational Environmental Satellite System (NPOESS). Beginning 1 October 2013, the JPSS baseline consists of a suite of five instruments: advanced microwave and infrared sounders critical for short- and medium-range weather forecasting; an advanced visible and infrared imager needed for environmental assessments such as snow/ice cover, droughts, volcanic ash, forest fires and surface temperature; ozone sensor primarily used for global monitoring of ozone and input to weather and climate models; and an Earth radiation budget sensor for monitoring the Earth's energy budget. NASA will fund the Earth radiation budget sensor and the ozone limb sensor for the second JPSS operational satellite--JPSS-2. JPSS is implemented through a partnership between NOAA and the U.S. National Aeronautics and Space Administration (NASA). NOAA is responsible for overall funding; maintaining the high-level requirements; establishing international and interagency partnerships; developing the science and algorithms, and user engagement; NOAA also provides product data distribution and archiving of JPSS data. NASA's role is to serve as acquisition Center of Excellence, providing acquisition of instruments, spacecraft and the multimission ground system, and early mission implementation through turnover to NOAA for operations.

  7. A survey instrument for measuring vaccine acceptance.

    Science.gov (United States)

    Sarathchandra, Dilshani; Navin, Mark C; Largent, Mark A; McCright, Aaron M

    2018-04-01

    Accurately measuring vaccine acceptance is important, especially under current conditions in which misinformation may increase public anxiety about vaccines and politicize vaccination policies. We integrated substantive knowledge, conceptualization and measurement expertise, and survey design principles to develop an instrument for measuring vaccine acceptance across the general public. Given this broad goal, we expect our novel instrument will complement, rather than replace, existing instruments designed specifically to measure parents' vaccine hesitancy. Our instrument measures five key facets of vaccine acceptance: (1) perceived safety of vaccines; (2) perceived effectiveness and necessity of vaccines; (3) acceptance of the selection and scheduling of vaccines; (4) positive values and affect toward vaccines; and (5) perceived legitimacy of authorities to require vaccinations. We report results of analyses demonstrating the reliability and validity of this instrument. High Cronbach's alpha values for five sub-scales and for the full scale indicate the instrument's reliability, and the consistent performance of expected predictors (i.e., trust in biologists, conspiratorial ideation, and political ideology) demonstrates the instrument's construct validity. Further, scientific reasoning increases vaccine acceptance among liberals but decreases vaccine acceptance among conservatives, which is consistent with motivated cognition. Also, trust in biologists has a stronger positive effect on vaccine acceptance among conservatives than among liberals, signaling a potentially promising means to reduce political polarization on vaccines and increase vaccine acceptance across the general public. We end by identifying key ways that public health researchers, science studies scholars, and health practitioners may employ the full (or short) version of our vaccine acceptance instrument. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Instrumentation for accelerators

    International Nuclear Information System (INIS)

    Sen, T.J.; De, T.K.; Ranganathan, M.K.; Basak, G.C.

    1989-01-01

    Along with the various system development for the accelerator, it was necessary to develop the instrumentation facility for the cyclotron. It started with the development of various vacuum instruments like ionization gauge control unit for measurement of pressure from 10 -4 torr to 10 -9 torr, discharge gauge control unit from 10 -4 torr to 10 -7 torr, thermocouple gauge control unit from 1 torr to 10 -3 torr. Process control instrumentation includes temperature measurement for freon cooled baffle and als o for low conductivity water. Control console required various digital panel meters for measurement of various parameters of the cyclotron. Various radiation monitoring instruments are also taken care of by the instrumentation facility. This paper describes in brief these various instruments. (author). 3 f igs

  9. Instrumentation a reader

    CERN Document Server

    Pope, P

    1990-01-01

    This book contains a selection of papers and articles in instrumentation previously pub­ lished in technical periodicals and journals of learned societies. Our selection has been made to illustrate aspects of current practice and applications of instrumentation. The book does not attempt to be encyclopaedic in its coverage of the subject, but to provide some examples of general transduction techniques, of the sensing of particular measurands, of components of instrumentation systems and of instrumentation practice in two very different environments, the food industry and the nuclear power industry. We have made the selection particularly to provide papers appropriate to the study of the Open University course T292 Instrumentation. The papers have been chosen so that the book covers a wide spectrum of instrumentation techniques. Because of this, the book should be of value not only to students of instrumen­ tation, but also to practising engineers and scientists wishing to glean ideas from areas of instrumen...

  10. Radiation measurement instruments

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The requirements and characteristics of radiation measurement instruments vary according to the circumstances under which they are used (field, area, laboratory conditions) and according to their purpose (radiation survey, personal monitoring, use in emergencies, or alpha, beta or gamma counting). In fact, radiation measurement instruments are so varied that only an overview has been presented here. Groups of instruments for these and other conditions or uses are presented in tabular form together with their operational characteristics and requirements. While examples of calibrations, efficiencies and variability of all the listed instruments are not given in this chapter, these parameters are illustrated for the most important types of gamma and beta survey instruments, in some cases with a specific instrument used as an example. Some of the important parameters that need to be considered for laboratory counting of alpha and beta particles are presented. Charts for determination of optimum sample and background counting times, errors and statistics are given

  11. Investigation of propagation algorithms for ray-tracing simulation of polarized neutrons

    DEFF Research Database (Denmark)

    Bergbäck Knudsen, Erik; Tranum-Rømer, A.; Willendrup, Peter Kjær

    2014-01-01

    Ray-tracing of polarized neutrons faces a challenge when the neutron propagates through an inhomogeneous magnetic field. This affects simulations of novel instruments using encoding of energy or angle into the neutron spin. We here present a new implementation of propagation of polarized neutrons...... within the McStas simulation package and show that it outperforms the de-facto standard method implemented in the NISP package by Seeger and Daemen. We include simulation of a simplified model of a spin-echo instrument, including a simple virtual experiment.......Ray-tracing of polarized neutrons faces a challenge when the neutron propagates through an inhomogeneous magnetic field. This affects simulations of novel instruments using encoding of energy or angle into the neutron spin. We here present a new implementation of propagation of polarized neutrons...

  12. The Primordial Inflation Polarization ExploreR (PIPER)

    Science.gov (United States)

    Gandilo, Natalie; Ade, Peter; Benford, Dominic; Bennett, Charles; Chuss, David; Datta, Rahul; Dotson, Jessie; Essinger-Hileman, Thomas; Fixsen, Dale; Halpern, Mark; Hilton, Gene; Hinshaw, Gary; Irwin, Kent; Jhabvala, Christine; Kimball, Mark; Kogut, Al; Lowe, Luke; McMahon, Jeff; Miller, Timothy; Mirel, Paul; Moseley, Samuel Harvey; Pawlyk, Samuel; Rodriguez, Samelys; Sharp, Elmer; Shirron, Peter; Staguhn, Johannes G.; Sullivan, Dan; Switzer, Eric; Taraschi, Peter; Tucker, Carole; Walts, Alexander; Wollack, Edward

    2018-01-01

    The Primordial Inflation Polarization ExploreR (PIPER) is a balloon-borne telescope designed to map the large scale polarization of the Cosmic Microwave Background as well as the polarized emission from galactic dust at 200, 270, 350, and 600 GHz, with 21, 15, 14, and 14 arcminutes of angular resolution respectively. PIPER uses twin telescopes with Variable-delay Polarization Modulators to simultaneously map Stokes I, Q, U and V. Cold optics and the lack of a warm window allow the instrument to achieve background limited sensitivity, with mapping speed approximately 10 times faster than a similar instrument with a single ambient-temperature mirror. Over the course of 8 conventional balloon flights from the Northern and Southern hemisphere, PIPER will map 85% of the sky, measuring the B-mode polarization spectrum from the reionization bump to l~300, and placing an upper limit on the tensor-to-scalar ratio of rMexico, and the first science flight is planned for June 2018 from Palestine, Texas.

  13. Radiation protection instrument 1993

    International Nuclear Information System (INIS)

    1993-04-01

    The Radiation Protection Instrument, 1993 (Legislative Instrument 1559) prescribes the powers and functions of the Radiation Protection Board established under the Ghana Atomic Energy Commission by the Atomic Energy Commission (Amendment) Law, 1993 (P.N.D.C. Law 308). Also included in the Legislative Instrument are schedules on control and use of ionising radiation and radiation sources as well as procedures for notification, licensing and inspection of ionising radiation facilities. (EAA)

  14. Polarization analysis for magnetic field imaging at RADEN in J-PARC/MLF

    Science.gov (United States)

    Shinohara, Takenao; Hiroi, Kosuke; Su, Yuhua; Kai, Tetsuya; Nakatani, Takeshi; Oikawa, Kenichi; Segawa, Mariko; Hayashida, Hirotoshi; Parker, Joseph D.; Matsumoto, Yoshihiro; Zhang, Shuoyuan; Kiyanagi, Yoshiaki

    2017-06-01

    Polarized neutron imaging is an attractive method for visualizing magnetic fields in a bulk object or in free space. In this technique polarization of neutrons transmitted through a sample is analyzed position by position to produce an image of the polarization distribution. In particular, the combination of three-dimensional spin analysis and the use of a pulsed neutron beam is very effective for the quantitative evaluation of both field strength and direction by means of the analysis of the wavelength dependent polarization vector. Recently a new imaging instrument “RADEN” has been constructed at the beam line of BL22 of the Materials and Life Science Experimental Facility (MLF) at J-PARC, which is dedicated to energy-resolved neutron imaging experiments. We have designed a polarization analysis apparatus for magnetic field imaging at the RADEN instrument and have evaluated its performance.

  15. Instrumentation for PSD-based neutron diffractometers at Dhruva ...

    Indian Academy of Sciences (India)

    positions and data is acquired simultaneously from all the PSDs. Throughput is further improved by using multiple PSDs at each position. Various instruments like the powder diffractometer, high-Q diffractometer, polarized neutron reflectometer, quasi-elastic neutron spectrometer, small-angle neutron spectrometer all use ...

  16. Ocean Optics Instrumentation Systems

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides instrumentation suites for a wide variety of measurements to characterize the ocean’s optical environment. These packages have been developed to...

  17. Networked Instrumentation Element

    Data.gov (United States)

    National Aeronautics and Space Administration — Armstrong researchers have developed a networked instrumentation system that connects modern experimental payloads to existing analog and digital communications...

  18. Creating a Super Instrument

    DEFF Research Database (Denmark)

    Kallionpää, Maria; Gasselseder, Hans-Peter

    2015-01-01

    interested in different ways of "supersizing" acoustic instruments in order to open up previously-unheard instrumental sounds. This leads us to the question of what constitutes a super instrument and what challenges does it pose aesthetically and technically? Although the classical music performers have......Thanks to the development of new technology, musical instruments are no more tied to their existing acoustic or technical limitations as almost all parameters can be augmented or modified in real time. An increasing number of composers, performers, and computer programmers have thus become...

  19. Instrument validation project

    International Nuclear Information System (INIS)

    Reynolds, B.A.; Daymo, E.A.; Geeting, J.G.H.; Zhang, J.

    1996-06-01

    Westinghouse Hanford Company Project W-211 is responsible for providing the system capabilities to remove radioactive waste from ten double-shell tanks used to store radioactive wastes on the Hanford Site in Richland, Washington. The project is also responsible for measuring tank waste slurry properties prior to injection into pipeline systems, including the Replacement of Cross-Site Transfer System. This report summarizes studies of the appropriateness of the instrumentation specified for use in Project W-211. The instruments were evaluated in a test loop with simulated slurries that covered the range of properties specified in the functional design criteria. The results of the study indicate that the compact nature of the baseline Project W-211 loop does not result in reduced instrumental accuracy resulting from poor flow profile development. Of the baseline instrumentation, the Micromotion densimeter, the Moore Industries thermocouple, the Fischer and Porter magnetic flow meter, and the Red Valve Pressure transducer meet the desired instrumental accuracy. An alternate magnetic flow meter (Yokagawa) gave nearly identical results as the baseline fischer and Porter. The Micromotion flow meter did not meet the desired instrument accuracy but could potentially be calibrated so that it would meet the criteria. The Nametre on-line viscometer did not meet the desired instrumental accuracy and is not recommended as a quantitative instrument although it does provide qualitative information. The recommended minimum set of instrumentation necessary to ensure the slurry meets the Project W-058 acceptance criteria is the Micromotion mass flow meter and delta pressure cells

  20. Instrument performance evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Swinth, K.L.

    1993-03-01

    Deficiencies exist in both the performance and the quality of health physics instruments. Recognizing the implications of such deficiencies for the protection of workers and the public, in the early 1980s the DOE and the NRC encouraged the development of a performance standard and established a program to test a series of instruments against criteria in the standard. The purpose of the testing was to establish the practicality of the criteria in the standard, to determine the performance of a cross section of available instruments, and to establish a testing capability. Over 100 instruments were tested, resulting in a practical standard and an understanding of the deficiencies in available instruments. In parallel with the instrument testing, a value-impact study clearly established the benefits of implementing a formal testing program. An ad hoc committee also met several times to establish recommendations for the voluntary implementation of a testing program based on the studies and the performance standard. For several reasons, a formal program did not materialize. Ongoing tests and studies have supported the development of specific instruments and have helped specific clients understand the performance of their instruments. The purpose of this presentation is to trace the history of instrument testing to date and suggest the benefits of a centralized formal program.

  1. Measurement of electrical polar symmetry in turbogenerator rotors

    International Nuclear Information System (INIS)

    Ramírez-Niño, J; González Vázquez, A

    2012-01-01

    This paper presents a measurement technique and an analysis of the electrical polar symmetry in turbogenerator rotors using the so-called recurrent pulse comparison with the injection of charge as the excitation source. The polar symmetry should be measured because it provides information that allows electrical insulation failures in the rotor winding to be detected. A simple electrical model for the rotor is introduced, and the technique for comparing the recurrent pulses is analysed in detail. The particular measurement instrumentation and the analysis of the results obtained in the time and frequency domains, including their relation to the rotor failures, are also described. (paper)

  2. CIV Polarization Measurements Using a Vacuum Ultraviolet Fabry Perot

    Science.gov (United States)

    West, Edward A.

    2009-01-01

    Marshall Space Flight Center's (MSFC) is developing a Vacuum Ultraviolet (VUV) Fabry Perot that will be launched on a sounding rocket for high throughput, high-cadence, extended field of view CIV (155nm) measurements. These measurements will provide (i) Dopplergrams for studies of waves, oscillations, explosive events, and mass motions through the transition region, and, (ii), polarization measurements to study the magnetic field in the transition region. This paper will describe the scientific goals of the instrument, a brief description of the optics and the polarization characteristics of the VUV Fabry Perot.

  3. SCIAMACHY’s View of the Polar Atmosphere

    Science.gov (United States)

    Gottwald, M.; Krieg, E.; von Savigny, C.; Noël, S.; Reichl, A.; Bovensmann, H.; Burrows, J.P.

    2007-01-01

    The instrument SCIAMACHY onboard the European ENVISAT mission provides unique capabilities for deriving atmospheric geophysical parameters. Since its launch in early 2002 it has operated successfully in orbit. Due to ENVISAT’s high inclination orbit the polar regions are monitored continuously. We report here results about the status of the polar atmosphere in the past 5 years with special emphasis on the southern hemisphere. This part of the atmosphere is considered to be highly sensitive to anthropogenic impacts on the Earth system and thus to climate change. The acquired data permit retrieving information on the Earth’s atmosphere from troposphere up to the mesosphere

  4. Circularly polarized antennas

    CERN Document Server

    Gao, Steven; Zhu, Fuguo

    2013-01-01

    This book presents a comprehensive insight into the design techniques for different types of CP antenna elements and arrays In this book, the authors address a broad range of topics on circularly polarized (CP) antennas. Firstly, it introduces to the reader basic principles, design techniques and characteristics of various types of CP antennas, such as CP patch antennas, CP helix antennas, quadrifilar helix antennas (QHA), printed quadrifilar helix antennas (PQHA), spiral antenna, CP slot antennas, CP dielectric resonator antennas, loop antennas, crossed dipoles, monopoles and CP horns. Adva

  5. System for measuring the proton polarization in a polarized target

    International Nuclear Information System (INIS)

    Karnaukhov, I.M.; Lukhanin, A.A.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

    1984-01-01

    The system for measuring the proton polarization in a polarized target representing the high-sensitivity nuclear magnetic resonance (NMR) is described Q-meter with series connection and a circuit for measuring system resonance characteristic is used for NMR-absorption signal recording. Measuring coil is produced of a strip conductor in order to obtain uniform system sensitivity to polarization state in all target volume and improve signal-to-noise ratio. Polarization measuring system operates ion-line with the M-6000 computer. The total measuring error for the value of free proton polarization in target taking into account the error caused by local depolarization of working substance under irradiation by high-intense photon beam is <= 6%. Long-term application of the described system for measuring the proton polarization in the LUEh-20000 accelerator target used in the pion photoproduction experiments has demonstrated its high reliability

  6. Instrumentation Design and Development Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — RTTC has facilities for design, development and fabrication of: custominstrumentation, mobile instrumentation, miniaturized instrumentation, wirelessinstrumentation,...

  7. Design of a TW-SLIM Module for Dual Polarity Confinement, Transport, and Reactions

    Science.gov (United States)

    Garimella, Sandilya V. B.; Webb, Ian K.; Prabhakaran, Aneesh; Attah, Isaac K.; Ibrahim, Yehia M.; Smith, Richard D.

    2017-07-01

    Here we describe instrumental approaches for performing dual polarity ion confinement, transport, ion mobility separations, and reactions in structures for lossless ion manipulations (SLIM). Previous means of ion confinement in SLIM, based upon rf-generated pseudopotentials and DC fields for lateral confinement, cannot trap ions of opposite polarity simultaneously. Here we explore alternative approaches to provide simultaneous lateral confinement of both ion polarities. Traveling wave ion mobility (IM) separations experienced in such SLIM cause ions of both polarities to migrate in the same directions and exhibit similar separations. The ion motion (and relative motion of the two polarities) under both surfing and IM separation conditions are discussed. In surfing conditions the two polarities are transported losslessly and non-reactively in their respective potential minima (higher absolute voltage regions confine negative polarities, and lower absolute potential regions are populated by positive polarities). In separation mode, where ions roll over an overtaking traveling wave, the two polarities can interact during the rollovers. Strategies to minimize overlap of the two ion populations to prevent reactive losses during separations are presented. A theoretical treatment of the time scales over which two populations (injected into a DC field-free region of the dual polarity SLIM device) interact is considered, and SLIM designs for allowing ion/ion interactions and other manipulations with dual polarities at 4 Torr are presented.

  8. Overview of LOFT instrumentation

    International Nuclear Information System (INIS)

    Bixby, W.W.

    1979-01-01

    A description of instrumentation used in the Loss-of-Fluid Test (LOFT) large break Loss-of-Coolant Experiments is presented. Emphasis is placed on hydraulic and thermal measurements in the primary system piping and components, reactor vessel, and pressure suppression system. In addition, instrumentation which is being considered for measurement of phenomena during future small break testing is discussed

  9. Polar drive on OMEGA

    Directory of Open Access Journals (Sweden)

    Radha P.B.

    2013-11-01

    Full Text Available High-convergence polar-drive experiments are being conducted on OMEGA [T. R. Boehly et al., Opt. Commum. 133, 495 (1997] using triple-picket laser pulses. The goal of OMEGA experiments is to validate modeling of oblique laser deposition, heat conduction in the presence of nonradial thermal gradients in the corona, and implosion energetics in the presence of laser–plasma interactions such as crossed-beam energy transfer. Simulated shock velocities near the equator, where the beams are obliquely incident, are within 5% of experimentally inferred values in warm plastic shells, well within the required accuracy for ignition. High, near-one-dimensional areal density is obtained in warm-plastic-shell implosions. Simulated backlit images of the compressing core are in good agreement with measured images. Outstanding questions that will be addressed in the future relate to the role of cross-beam transfer in polar drive irradiation and increasing the energy coupled into the target by decreasing beam obliquity.

  10. Estimating Terra MODIS Polarization Effect Using Ocean Data

    Science.gov (United States)

    Wald, Andrew E.; Brinkmann, Jake; Wu, Aisheng; Xiong, Jack

    2016-01-01

    Terra MODIS has been known since pre-launch to have polarization sensitivity, particularly in shortest-wavelength bands 8 and 9. On-orbit reflectance trending of pseudo-invariant sites show a variation in reflectance as a function of band and scan mirror angle of incidence consistent with time-dependent polarization effects from the rotating double-sided scan mirror. The MODIS Characterization Support Team [MCST] estimates the Mueller matrix trending from this variation as observed from a single desert site, but this effect is not included in Collection 6 [C6] calibration. Here we extend the MCSTs current polarization sensitivity monitoring to two ocean sites distributed over latitude to helpestimate the uncertainties in the derived Mueller matrix. The Mueller matrix elements derived for polarization-sensitive Band 8 for a given site are found to be fairly insensitive to surface brdf modeling. The site-to-site variation is a measure of the uncertainty in the Mueller estimation.Results for band 8 show that the polarization correction reduces mirror-side striping by up to 50% and reduces the instrument polarization effect on reflectance time series of an ocean target.

  11. Well logging instrumental and methodological research

    International Nuclear Information System (INIS)

    Andrassy, L.; Barath, I.; Dorko, R.

    1983-01-01

    This part of the Annual Report of the Roland Eoetvoes Geophysical Institute (ELGI) of Hungary for 1982, summarizes the well logging instrumental and methodological researches of ELGI. The theoretical neutron diffusion fluxes for black and brown coals of Hungarian mines were calculated. A coal probe was developed and tested in boreholes using computerized data processing and interpretation. An X-ray radiometric method was used for the determination of Cu and Fe contents of minerals. Researches in the field of magnetic susceptibility and induced polarization logging are also summarized. A rapid analyzer for bauxite mining and a photorecorder for petroleum industry were developed by ELGI. (D.Gy.)

  12. QUIJOTE Experiment: status of telescopes and instrumentation

    Science.gov (United States)

    Pérez-de-Taoro, M. R.; Aguiar-González, M.; Cózar-Castellano, J.; Génova-Santos, R.; Gómez-Reñasco, F.; Hoyland, R.; Peláez-Santos, A.; Poidevin, F.; Tramonte, D.; Rebolo-López, R.; Rubiño-Martín, J. A.; Sánchez-de-la-Rosa, V.; Vega-Moreno, A.; Viera-Curbelo, T.; Vignaga, R.; Casas, F. J.; Martinez-Gonzalez, E.; Ortiz, D.; Aja, B.; Artal, E.; Cano-de-Diego, J. L.; de-la-Fuente, L.; Mediavilla, A.; Terán, J. V.; Villa, E.; Harper, S.; McCulloch, M.; Melhuish, S.; Piccirillo, L.; Lasenby, A.

    2016-07-01

    The QUIJOTE Experiment (Q-U-I JOint TEnerife) is a combined operation of two telescopes and three instruments working in the microwave band to measure the polarization of the Cosmic Microwave Background (CMB) from the northern hemisphere, at medium and large angular scales. The experiment is located at the Teide Observatory in Tenerife, one of the seven Canary Islands (Spain). The project is a consortium maintained by several institutions: the Instituto de Astrofísica de Canarias (IAC), the Instituto de Física de Cantabria (IFCA), the Communications Engineering Department (DICOM) at Universidad de Cantabria, and the Universities of Manchester and Cambridge. The consortium is led by the IAC.

  13. Polarized proton collider at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S.Y.; Luccio, A.; MacKay, W.W. E-mail: mackay@bnl.govhttp://www.rhichome.bnl.gov/People/waldowaldo@bnl.gov; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.N

    2003-03-01

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to {radical}s=500 GeV.

  14. Spin exchange in polarized deuterium

    International Nuclear Information System (INIS)

    Przewoski, B. von; Meyer, H.O.; Balewski, J.; Doskow, J.; Ibald, R.; Pollock, R.E.; Rinckel, T.; Wellinghausen, A.; Whitaker, T.J.; Daehnick, W.W.; Haeberli, W.; Schwartz, B.; Wise, T.; Lorentz, B.; Rathmann, F.; Pancella, P.V.; Saha, Swapan K.; Thoerngren-Engblom, P.

    2003-01-01

    We have measured the vector and tensor polarization of an atomic deuterium target as a function of the target density. The polarized deuterium was produced in an atomic beam source and injected into a storage cell. For this experiment, the atomic beam source was operated without rf transitions, in order to avoid complications from the unknown efficiency of these transitions. In this mode, the atomic beam is vector and tensor polarized and both polarizations can be measured simultaneously. We used a 1.2-cm-diam and 27-cm-long storage cell, which yielded an average target density between 3 and 9x10 11 at/cm 3 . We find that the tensor polarization decreases with increasing target density while the vector polarization remains constant. The data are in quantitative agreement with the calculated effect of spin exchange between deuterium atoms at low field

  15. Linear polarization of BY Draconis

    International Nuclear Information System (INIS)

    Koch, R.H.; Pfeiffer, R.J.

    1976-01-01

    Linear polarization measurements are reported in four bandpasses for the flare star BY Dra. The red polarization is intrinsically variable at a confidence level greater than 99 percent. On a time scale of many months, the variability is not phase-locked to either a rotational or a Keplerian ephemeris. The observations of the three other bandpasses are useful principally to indicate a polarization spectrum rising toward shorter wavelengths

  16. Polarity in Mammalian Epithelial Morphogenesis

    OpenAIRE

    Roignot, Julie; Peng, Xiao; Mostov, Keith

    2013-01-01

    Cell polarity is fundamental for the architecture and function of epithelial tissues. Epithelial polarization requires the intervention of several fundamental cell processes, whose integration in space and time is only starting to be elucidated. To understand what governs the building of epithelial tissues during development, it is essential to consider the polarization process in the context of the whole tissue. To this end, the development of three-dimensional organotypic cell culture model...

  17. A polarized alkali ion source

    International Nuclear Information System (INIS)

    Boettger, R.; Tungate, G.; Bauer, B.; Egelhof, P.; Moebius, K.H.; Steffens, E.

    1978-01-01

    The beam foil technique has been applied to detect nuclear vector polarization of a 10 keV 23 Na + beam. The result was about 70% of the atomic beam polarization thus limiting the depolarization by the surface ionizer to at most 30%. In a Coulomb excitation experiment with a tensor polarized 42 MeV 23 Na 7+ beam an effect of 0.011 +- 0.003 was measured yielding a value of t 20 approx. 0.04 for the beam polarization. The depolarization during the acceleration process can be estimated to be about 0.8. (orig.) [de

  18. The SLAC polarized electron source

    International Nuclear Information System (INIS)

    Tang, H.; Alley, R.; Frisch, J.

    1995-06-01

    The SLAC polarized electron source employs a photocathode DC high voltage gun with a loadlock and a YAG pumped Ti:sapphire laser system for colliding beam experiments or a flash lamp pumped Ti:sapphire laser for fixed target experiments. It uses a thin, strained GaAs(100) photocathode, and is capable of producing a pulsed beam with a polarization of ≥80% and a peak current exceeding 10 A. Its operating efficiency has reached 99%. The physics and technology of producing high polarization electron beams from a GaAs photocathode will be reviewed. The prospects of realizing a polarized electron source for future linear colliders will also be discussed

  19. Proceedings of the Japan-US workshop on plasma polarization spectroscopy and the fourth international symposium on plasma polarization spectroscopy

    International Nuclear Information System (INIS)

    Fujimoto, Takashi; Beiersdorfer, Peter

    2004-07-01

    The international meeting on Plasma Polarization Spectroscopy (PPS) was held at Kyoto University during February 4-6, 2004. This Proceedings book includes the summaries of the talks given in that meeting. Starting with the Overview talk by Csanak, the subjects cover: x-ray polarization experiments on z-pinches (plasma foci), and an x-pinch, a laser-produced plasma in a gas atmosphere, an interpretation of the polarized 1<- 0 x-ray laser line, polarization observation from various laser-produced plasmas including a recombining phase plasma, a report on the on-going project of a laser facility, several polarization observations on magnetically confined plasmas including the Large Helical Device and an ECR plasma, a new laser-induced fluorescence diagnostic method. On atomic physics side given are: various polarization measurements on EBIT, precision spectroscopy on the TEXTOR, user-friendly atomic codes. Instrumentation is also a subject of this book. The 18 of the presented papers are indexed individually. (J.P.N.)

  20. Remote instrument telemaintenance.

    Science.gov (United States)

    Laugier, A; Allahwerdi, N; Baudin, J; Gaffney, P; Grimson, W; Groth, T; Schilders, L

    1996-07-01

    In the past decade, great technological progress has been made in telemaintenance of mainframe and mini computers. As hardware technology is now available at an acceptable cost, computer aided trouble-shooting can be adapted to laboratory instrumentation in order to significantly improve repair time, avoid instrument downtime by taking advantage of predictive methods, and provide general diagnostic assistance. Depending on the size of the instrument, the telemaintenance facility can be dedicated to a single instrument or alternatively a telemaintenance server can manage multiple distributed small instruments through a Local Area Network. As complex failures can occur, the local diagnosis capabilities may be exceeded and automatic dialing for connection to computerized Remote Maintenance Centers is needed. The main advantages of such a centre, as compared to local diagnosis systems, are the increased access to more information and experience of failures from instrument installations, and consequently the provision of training data updates for Artificial Neural Networks and Knowledge Based Systems in general. When an abnormal situation is detected or anticipated by a diagnosis module, an automatic alert is given to the user, local diagnosis is activated, and for simple solutions, instructions are given to the operator. In the last resort, a human expert can be alerted who, with remote control tools, can attend to the failures. For both local and remote trouble-shooting, the data provided by the instrument and connected workstation is of paramount importance for the efficiency and accuracy of the diagnosis. Equally, the importance of standardization of telemaintenance communication protocols is addressed.

  1. CH1-ORB MOON MINI-RF 5 POLAR MOSAIC CALIBRATED DATA REC V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains lunar polar mosaics composed of calibrated data acquired from the Mini-RF (Mini-SAR) Forerunner instrument during the Chandrayaan-1 mission....

  2. V4: The Small Angle Scattering Instrument (SANS at BER II

    Directory of Open Access Journals (Sweden)

    Uwe Keiderling

    2016-11-01

    Full Text Available V4 is a small-angle neutron scatting instrument with an accessible range of scattering vector 0.01 nm-1 < Q < 8.5 nm-1. Outstanding features of the instrument are the polarized neutron option and the list mode data acquisition, allowing for time-resolved measurements with µs time resolution.

  3. Can Reliability of Multiple Component Measuring Instruments Depend on Response Option Presentation Mode?

    Science.gov (United States)

    Menold, Natalja; Raykov, Tenko

    2016-01-01

    This article examines the possible dependency of composite reliability on presentation format of the elements of a multi-item measuring instrument. Using empirical data and a recent method for interval estimation of group differences in reliability, we demonstrate that the reliability of an instrument need not be the same when polarity of the…

  4. Medical instruments in museums

    DEFF Research Database (Denmark)

    Söderqvist, Thomas; Arnold, Ken

    2011-01-01

    This essay proposes that our understanding of medical instruments might benefit from adding a more forthright concern with their immediate presence to the current historical focus on simply decoding their meanings and context. This approach is applied to the intriguingly tricky question of what...... actually is meant by a "medical instrument." It is suggested that a pragmatic part of the answer might lie simply in reconsidering the holdings of medical museums, where the significance of the physical actuality of instruments comes readily to hand....

  5. Instrumentation reference book

    CERN Document Server

    Boyes, Walt

    2002-01-01

    Instrumentation is not a clearly defined subject, having a 'fuzzy' boundary with a number of other disciplines. Often categorized as either 'techniques' or 'applications' this book addresses the various applications that may be needed with reference to the practical techniques that are available for the instrumentation or measurement of a specific physical quantity or quality. This makes it of direct interest to anyone working in the process, control and instrumentation fields where these measurements are essential.* Comprehensive and authoritative collection of technical information* Writte

  6. Microcomputers for nuclear instrumentation

    International Nuclear Information System (INIS)

    Byrd, J.S.

    1979-01-01

    Small, desk-top Commodore PET computers are being used to solve nuclear instrumentation problems at the Savannah River Laboratory (SRL). The ease of operating, programing, interfacing, and maintaining the PET computer makes it a cost-effective solution to many real-time instrumentation problems that involve both data acquisition and date processing. The IEEE-488 GPIB (General Purpose Instrument Bus) is an integral part of the PET hardware. This paper reviews GPIB design concepts and discusses SRL applications that use the PET computer as a GPIB controller. 11 figures, 2 tables

  7. The latest radiation instrument

    International Nuclear Information System (INIS)

    Kang, Se Sik; Gwon, Dal Gwan; Kim, Gyeong Geum

    2008-08-01

    This book deals with the latest radiation instrument, which is comprised of eight chapters. It explains X rays instrument for medial treatment, X-ray tube instrument and permissible burden with its history, structure and characteristic high voltage apparatus with high voltage rectifier circuit, X-ray control apparatus for medical treatment, X-ray image equipment X-ray television apparatus and CCD 205, X-ray apparatus of install and types, Digital X-ray apparatus with CR 261 and DR 269, performance management on X-ray for medical treatment with its history, necessity and management in the radiation field.

  8. Soil monitoring instrumentation

    International Nuclear Information System (INIS)

    Umbarger, C.J.

    1980-01-01

    The Los Alamos Scientific Laboratory (LASL) has an extensive program for the development of nondestructive assay instrumentation for the quantitative analysis of transuranic (TRU) materials found in bulk solid wastes generated by Department of Energy facilities and by the commercial nuclear power industry. Included are wastes generated in decontamination and decommissioning of outdated nuclear facilities as well as wastes from old waste burial ground exhumation programs. The assay instrumentation is designed to have detection limits below 10 nCi/g wherever practicable. Because of the topic of this workshop, only the assay instrumentation applied specifically to soil monitoring will be discussed here. Four types of soil monitors are described

  9. Soil monitoring instrumentation

    International Nuclear Information System (INIS)

    Umbarger, C.J.

    1981-01-01

    The Los Alamos Scientific Laboratory (LASL) has an extensive program for the development of nondestructive assay instrumentation for the quantitative analysis of transuranic (TRU) materials found in bulk solid wastes generated by Department of Energy facilities and by the commercial nuclear power industry. Included are wastes generated in decontamination and decommissioning of outdated nuclear facilities, as well as from old waste-burial-ground exhumation programs. The assay instrumentation is designed to have detection limits below 10 nCi/g wherever practicable. The assay instrumentation that is applied specifically to soil monitoring is discussed

  10. MEASURING THE IMPACT OF REDISTRIBUTION ON INCOME INEQUALITY AND POLARIZATION

    Directory of Open Access Journals (Sweden)

    Maria Molnar

    2010-12-01

    Full Text Available The redistribution, i.e. social transfers (benefits, taxes and social contributions, has an important contribution in reducing income inequality and polarization, the tax-benefit system being the main instrument of the income policy. The paper presents the results of an evaluation of the impact of income redistribution on households’ income inequality and polarization in Romania during 1995 to 2008 years. In the first part of the paper the main methodological issues of the measurement are being reviewed. According to the results of the measurement, which are dealt with in the second section, the redistribution had an increasing lessening effect on the extent of inequality and polarization. The social transfers, especially pensions, were the main equalising component of the redistribution over the entire period.

  11. Forward instrumentation for ILC detectors

    Energy Technology Data Exchange (ETDEWEB)

    Abramowicz, Halina [Tel Aviv Univ. (Israel); Abusleme, Angel [Stanford Univ., CA (United States); Afanaciev, Konstantin [NCPHEP, Minsk (BY)] (and others)

    2010-09-15

    Two special calorimeters are foreseen for the instrumentation of the very forward region of the ILC detector, a luminometer designed to measure the rate of low angle Bhabha scattering events with a precision better than 10{sup -3} and a low polar angle calorimeter, adjacent to the beam-pipe. The latter will be hit by a large amount of beamstrahlung remnants. The amount and shape of these depositions will allow a fast luminosity estimate and the determination of beam parameters. The sensors of this calorimeter must be radiation hard. Both devices will improve the hermeticity of the detector in the search for new particles. Finely segmented and very compact calorimeters will match the requirements. Due to the high occupancy fast front-end electronics is needed. The design of the calorimeters developed and optimised with Monte Carlo simulations is presented. Sensors and readout electronics ASICs have been designed and prototypes are available. Results on the performance of these major components are summarised. (orig.)

  12. Carbon Footprint Reduction Instruments

    Science.gov (United States)

    This page outlines the major differences between Renewable Energy Certificates (REC) and Project Offsets and what types of claims each instrument allows the organization to make in regards to environmental emissions claims.

  13. CCAT Heterodyne Instrument Development

    Data.gov (United States)

    National Aeronautics and Space Administration — This work will extend and proof-out the design concept for a high pixel count (128 pixels in 2 bands) submillimeter-wave heterodyne receiver array instrument for the...

  14. Fiber Optics Instrumentation Development

    Science.gov (United States)

    Chan, Patrick Hon Man; Parker, Allen R., Jr.; Richards, W. Lance

    2010-01-01

    This is a general presentation of fiber optics instrumentation development work being conducted at NASA Dryden for the past 10 years and recent achievements in the field of fiber optics strain sensors.

  15. Medical instruments in museums

    DEFF Research Database (Denmark)

    Söderqvist, Thomas; Arnold, Ken

    2011-01-01

    This essay proposes that our understanding of medical instruments might benefit from adding a more forthright concern with their immediate presence to the current historical focus on simply decoding their meanings and context. This approach is applied to the intriguingly tricky question of what a...... actually is meant by a "medical instrument." It is suggested that a pragmatic part of the answer might lie simply in reconsidering the holdings of medical museums, where the significance of the physical actuality of instruments comes readily to hand.......This essay proposes that our understanding of medical instruments might benefit from adding a more forthright concern with their immediate presence to the current historical focus on simply decoding their meanings and context. This approach is applied to the intriguingly tricky question of what...

  16. Challenges in marine instrumentation

    Digital Repository Service at National Institute of Oceanography (India)

    Afzulpurkar, S.; Desa, E.; Joseph, A.; Chakraborty, B.; Nayak, M.R.; Ranade, G.

    challenge for technology. Biosensors which can detect bioluminescence and other biological activities would play a major role. Autonomous instrumentation outfitted with different types of in-situ sensors would collect data without disturbing the system...

  17. Nuclear instrument technician training

    International Nuclear Information System (INIS)

    Wollesen, E.S.

    1991-01-01

    This paper reports on Nuclear Instrument Technician (NIT) training that has developed at an accelerated rate over the past three decades. During the 1960's commercial nuclear power plants were in their infancy. For that reason, there is little wonder that NIT training had little structure and little creditability. NIT training, in many early plants, was little more than On-The Job Training (OJT). The seventies brought changes in Instrumentation and Controls as well as emphasis on the requirements for more in depth training and documentation. As in the seventies, the eighties saw not only changes in technologies but tighter requirements, standardized training and the development of accredited Nuclear Instrument Training; thus the conclusion: Nuclear Instrument Training Isn't What It Used To Be

  18. VIRUS instrument collimator assembly

    Science.gov (United States)

    Marshall, Jennifer L.; DePoy, Darren L.; Prochaska, Travis; Allen, Richard D.; Williams, Patrick; Rheault, Jean-Philippe; Li, Ting; Nagasawa, Daniel Q.; Akers, Christopher; Baker, David; Boster, Emily; Campbell, Caitlin; Cook, Erika; Elder, Alison; Gary, Alex; Glover, Joseph; James, Michael; Martin, Emily; Meador, Will; Mondrik, Nicholas; Rodriguez-Patino, Marisela; Villanueva, Steven; Hill, Gary J.; Tuttle, Sarah; Vattiat, Brian; Lee, Hanshin; Chonis, Taylor S.; Dalton, Gavin B.; Tacon, Mike

    2014-07-01

    The Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument is a baseline array 150 identical fiber fed optical spectrographs designed to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The collimator subassemblies of the instrument have been assembled in a production line and are now complete. Here we review the design choices and assembly practices used to produce a suite of identical low-cost spectrographs in a timely fashion using primarily unskilled labor.

  19. Maintenance of scientific instruments

    International Nuclear Information System (INIS)

    Lucero, E.

    1986-01-01

    During the last years Colombia has increased the use of nuclear techniques, instruments and equipment in ambitious health programs, as well as in research centers, industry and education; this has resulted in numerous maintenance problems. As an alternative solution IAN has established a Central Maintenance Laboratory for nuclear instruments within an International Atomic Energy Agency program for eight Latin American and nine Asian Countries. Established strategies and some results are detailed in this writing

  20. OMPS Limb Profiler Instrument Performance Assessment

    Science.gov (United States)

    Jaross, Glen R.; Bhartia, Pawan K.; Chen, Grace; Kowitt, Mark; Haken, Michael; Chen, Zhong; Xu, Philippe; Warner, Jeremy; Kelly, Thomas

    2014-01-01

    Following the successful launch of the Ozone Mapping and Profiler Suite (OMPS) aboard the Suomi National Polar-orbiting Partnership (SNPP) spacecraft, the NASA OMPS Limb team began an evaluation of instrument and data product performance. The focus of this paper is the instrument performance in relation to the original design criteria. Performance that is closer to expectations increases the likelihood that limb scatter measurements by SNPP OMPS and successor instruments can form the basis for accurate long-term monitoring of ozone vertical profiles. The team finds that the Limb instrument operates mostly as designed and basic performance meets or exceeds the original design criteria. Internally scattered stray light and sensor pointing knowledge are two design challenges with the potential to seriously degrade performance. A thorough prelaunch characterization of stray light supports software corrections that are accurate to within 1% in radiances up to 60 km for the wavelengths used in deriving ozone. Residual stray light errors at 1000nm, which is useful in retrievals of stratospheric aerosols, currently exceed 10%. Height registration errors in the range of 1 km to 2 km have been observed that cannot be fully explained by known error sources. An unexpected thermal sensitivity of the sensor also causes wavelengths and pointing to shift each orbit in the northern hemisphere. Spectral shifts of as much as 0.5nm in the ultraviolet and 5 nm in the visible, and up to 0.3 km shifts in registered height, must be corrected in ground processing.

  1. Digibaro pressure instrument onboard the Phoenix Lander

    Science.gov (United States)

    Harri, A.-M.; Polkko, J.; Kahanpää, H. H.; Schmidt, W.; Genzer, M. M.; Haukka, H.; Savijarv1, H.; Kauhanen, J.

    2009-04-01

    The Phoenix Lander landed successfully on the Martian northern polar region. The mission is part of the National Aeronautics and Space Administration's (NASA's) Scout program. Pressure observations onboard the Phoenix lander were performed by an FMI (Finnish Meteorological Institute) instrument, based on a silicon diaphragm sensor head manufactured by Vaisala Inc., combined with MDA data processing electronics. The pressure instrument performed successfully throughout the Phoenix mission. The pressure instrument had 3 pressure sensor heads. One of these was the primary sensor head and the other two were used for monitoring the condition of the primary sensor head during the mission. During the mission the primary sensor was read with a sampling interval of 2 s and the other two were read less frequently as a check of instrument health. The pressure sensor system had a real-time data-processing and calibration algorithm that allowed the removal of temperature dependent calibration effects. In the same manner as the temperature sensor, a total of 256 data records (8.53 min) were buffered and they could either be stored at full resolution, or processed to provide mean, standard deviation, maximum and minimum values for storage on the Phoenix Lander's Meteorological (MET) unit.The time constant was approximately 3s due to locational constraints and dust filtering requirements. Using algorithms compensating for the time constant effect the temporal resolution was good enough to detect pressure drops associated with the passage of nearby dust devils.

  2. The Inelastic Instrument suite at the SNS

    International Nuclear Information System (INIS)

    Granroth, Garrett E; Abernathy, Douglas L; Ehlers, Georg; Hagen, Mark E; Herwig, Kenneth W; Mamontov, Eugene; Ohl, Michael E; Wildgruber, Christoph U

    2008-01-01

    The instruments in the extensive suite of spectrometers at the SNS are in various stages of installation and commissioning. The Back Scattering Spectrometer (BASIS) is installed and is in commissioning. It's near backscattering analyzer crystals provide the 3 eV resolution as expected. BASIS will enter the user program in the fall of 2007. The ARCS wide angular-range thermal to epithermal neutron spectrometer will come on line in the fall of 2007 followed shortly by the Cold Neutron Chopper Spectrometer. These two direct geometry instruments provide moderate resolution and the ability to trade resolution for flux. In addition both instruments have detector coverage out to 140o to provide a large Q range. The SEQUOIA spectrometer, complete in 2008, is the direct geometry instrument that will provide fine resolution in the thermal to epithermal range. The Spin-Echo spectrometer, to be completed on a similar time scale, will provide the finest energy resolution worldwide. The HYSPEC spectrometer, available no later than 2011, will provide polarized capabilities and optimized flux in the thermal energy range. Finally, the Vision chemical spectrometer will use crystal analyzers to study energy transfers into the epithermal range

  3. Polar Biomedical Research - An Assessment.

    Science.gov (United States)

    1982-10-01

    to grow more crops in subpolar Alaska. The severity of the polar conditions in Antarctica allow no practical method for providing volumes of plant food...for an expanded population. Any experiments in polar regions in food production involving geothermal heat, solar energy, hydroponics , or aquaculture

  4. Create a Polarized Light Show.

    Science.gov (United States)

    Conrad, William H.

    1992-01-01

    Presents a lesson that introduces students to polarized light using a problem-solving approach. After illustrating the concept using a slinky and poster board with a vertical slot, students solve the problem of creating a polarized light show using Polya's problem-solving methods. (MDH)

  5. Carbon nanotube fiber terahertz polarizer

    Energy Technology Data Exchange (ETDEWEB)

    Zubair, Ahmed [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Tsentalovich, Dmitri E.; Young, Colin C. [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Heimbeck, Martin S. [Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Everitt, Henry O. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Pasquali, Matteo [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Kono, Junichiro, E-mail: kono@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

    2016-04-04

    Conventional, commercially available terahertz (THz) polarizers are made of uniformly and precisely spaced metallic wires. They are fragile and expensive, with performance characteristics highly reliant on wire diameters and spacings. Here, we report a simple and highly error-tolerant method for fabricating a freestanding THz polarizer with nearly ideal performance, reliant on the intrinsically one-dimensional character of conduction electrons in well-aligned carbon nanotubes (CNTs). The polarizer was constructed on a mechanical frame over which we manually wound acid-doped CNT fibers with ultrahigh electrical conductivity. We demonstrated that the polarizer has an extinction ratio of ∼−30 dB with a low insertion loss (<0.5 dB) throughout a frequency range of 0.2–1.1 THz. In addition, we used a THz ellipsometer to measure the Müller matrix of the CNT-fiber polarizer and found comparable attenuation to a commercial metallic wire-grid polarizer. Furthermore, based on the classical theory of light transmission through an array of metallic wires, we demonstrated the most striking difference between the CNT-fiber and metallic wire-grid polarizers: the latter fails to work in the zero-spacing limit, where it acts as a simple mirror, while the former continues to work as an excellent polarizer even in that limit due to the one-dimensional conductivity of individual CNTs.

  6. Polarization-preserving holey fibers

    DEFF Research Database (Denmark)

    Broeng, Jes; Mogilevtsev, Dmitri; Libori, Stig E. Barkou

    2001-01-01

    In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization...

  7. Polarized Scintillating Targets at Psi

    Science.gov (United States)

    van den Brandt, B.; Bunyatova, E. I.; Hautle, P.; Konter, J. A.; Mango, S.

    2001-02-01

    Scintillating polarized targets are now routinely available: blocks of 18×18×5 mm scintillating organic polymer, doped with TEMPO, polarized dynamically in a field of 2.5 T in a vertical 3He-4He dilution refrigerator. A 19 mm diameter plastic lightguide transports the scintillation light from the sample in the mixing chamber to a photomultiplier outside the cryostat.

  8. UV Coatings, Polarization, and Coronagraphy

    Science.gov (United States)

    Bolcar, Matthew R.; Quijada, Manuel; West, Garrett; Balasubramanian, Bala; Krist, John; Martin, Stefan; Sabatke, Derek

    2016-01-01

    Presenation for the Large UltraViolet Optical Infrared (LUVOIR) and Habitable Exoplanet Imager (HabEx) Science and Technology Definition Teams (STDT) on technical considerations regarding ultraviolet coatings, polarization, and coronagraphy. The presentations review the state-of-the-art in ultraviolet coatings, how those coatings generate polarization aberrations, and recent study results from both the LUVOIR and HabEx teams.

  9. Polarization Imaging and Insect Vision

    Science.gov (United States)

    Green, Adam S.; Ohmann, Paul R.; Leininger, Nick E.; Kavanaugh, James A.

    2010-01-01

    For several years we have included discussions about insect vision in the optics units of our introductory physics courses. This topic is a natural extension of demonstrations involving Brewster's reflection and Rayleigh scattering of polarized light because many insects heavily rely on optical polarization for navigation and communication.…

  10. Climate Drives Polar Bear Origins

    Science.gov (United States)

    In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

  11. Future of radiological instrumentation

    International Nuclear Information System (INIS)

    Lucas, A.C.

    1988-01-01

    Future trends in the development of radiation protection instrumentation can be expected to be closely related to current trends in political and social activity that drive legislation, rule-making, and standard practice, with assistance provided by trends in material and electronic technology. Wide-range performance will be emphasized to arm the daily worker with instruments that routinely log background rates and, at the same time, are prepared to measure accident rates. Separate and simultaneous accumulation of data from several sensors to ensure complete coverage of the radiation types will be common. Mathematical manipulation of data will provide for summary data logging and, in some cases, solutions to integral equations to provide corrections to experimental data. Instruments will become more reliable by way of self-checking and correction. Miniaturization and large-scale integration of measuring instruments will provide some instrumentation for the people at large. To be effective, the instruments will necessarily cover a wide range and be very reliable. The net result of these several trends will provide for a widespread understanding of radiation protection and an implementation of as low as reasonably achievable among large segments of the population

  12. [The instrument for thermography].

    Science.gov (United States)

    Hamaguchi, Shinsuke

    2014-07-01

    Thermography is an imaging method using the instrument to detect infrared rays emitted from the body surface, and to plot them as a distribution diagram of the temperature information. Therefore, a thermographic instrument can be assumed to measure the skin temperature of the diseased region. Such an instrument is a useful device for noninvasive and objective assessment of various diseases. Examination using a thermographic instrument can assess the autonomic dysfunction by measuring the skin blood flow involved with the sympathetic innervation. Thermography is useful in assisting the determination of the therapeutic effect. However, autonomic dysfunction should be confirmed correctly with the assessment of thermatome that shows abnormal thermal distribution in the region of the disease. Thermography should make noticeable the difference between the body temperature of abnormal and normal sites, and show the alteration of temperature. Monitoring using thermography is useful to determine the effect of sympathetic nerve block. If a thermographic instrument is used, it is important that examiners should understand the function of the instrument, as well as its advantages and disadvantages.

  13. Problems with radiological surveillance instrumentation

    International Nuclear Information System (INIS)

    Swinth, K.L.; Tanner, J.E.; Fleming, D.M.

    1984-09-01

    Many radiological surveillance instruments are in use at DOE facilities throughout the country. These instruments are an essential part of all health physics programs, and poor instrument performance can increase program costs or compromise program effectiveness. Generic data from simple tests on newly purchased instruments shows that many instruments will not meet requirements due to manufacturing defects. In other cases, lack of consideration of instrument use has resulted in poor acceptance of instruments and poor reliability. The performance of instruments is highly variable for electronic and mechanical performance, radiation response, susceptibility to interferences and response to environmental factors. Poor instrument performance in these areas can lead to errors or poor accuracy in measurements

  14. The utility of polarized heliospheric imaging for space weather monitoring.

    Science.gov (United States)

    DeForest, C E; Howard, T A; Webb, D F; Davies, J A

    2016-01-01

    A polarizing heliospheric imager is a critical next generation tool for space weather monitoring and prediction. Heliospheric imagers can track coronal mass ejections (CMEs) as they cross the solar system, using sunlight scattered by electrons in the CME. This tracking has been demonstrated to improve the forecasting of impact probability and arrival time for Earth-directed CMEs. Polarized imaging allows locating CMEs in three dimensions from a single vantage point. Recent advances in heliospheric imaging have demonstrated that a polarized imager is feasible with current component technology.Developing this technology to a high technology readiness level is critical for space weather relevant imaging from either a near-Earth or deep-space mission. In this primarily technical review, we developpreliminary hardware requirements for a space weather polarizing heliospheric imager system and outline possible ways to flight qualify and ultimately deploy the technology operationally on upcoming specific missions. We consider deployment as an instrument on NOAA's Deep Space Climate Observatory follow-on near the Sun-Earth L1 Lagrange point, as a stand-alone constellation of smallsats in low Earth orbit, or as an instrument located at the Sun-Earth L5 Lagrange point. The critical first step is the demonstration of the technology, in either a science or prototype operational mission context.

  15. Instrument pre-development activities for FLEX

    Science.gov (United States)

    Pettinato, L.; Fossati, E.; Coppo, P. M.; Taiti, A.; Labate, D.; Capanni, A.; Taccola, M.; Bézy, J. L.; Francois, M.; Meynart, R.; Erdmann, L.; Triebel, P.

    2017-09-01

    The FLuorescence Imaging Spectrometer (FLORIS) is the payload of the FLuorescence Explorer Mission (FLEX) of the European Space Agency. The mission objective is to perform quantitative measurements of the solar induced vegetation fluorescence to monitor photosynthetic activity. FLORIS works in a push-broom configuration and it is designed to acquire data in the 500-780 nm spectral range, with a sampling of 0.1 nm in the oxygen bands (759-769 nm and 686- 697 nm) and 0.5-2.0 nm in the red edge, chlorophyll absorption and Photochemical Reflectance Index bands. FLEX will fly in formation with Sentinel-3 to benefit of the measurements made by the Sentinel-3 instruments OLCI and SLSTR, particularly for cloud screening, proper characterization of the atmospheric state and determination of the surface temperature. The instrument concept is based on a common telescope and two modified Offner spectrometers with reflective concave gratings both for the High Resolution (HR) and Low Resolution (LR) spectrometers. In the frame of the instrument pre-development Leonardo Company (I) has built and tested an elegant breadboard of the instrument consisting of the telescope and the HR spectrometer. The development of the LR spectrometer is in charge of OHB System AG (D) and is currently in the manufacturing phase. The main objectives of the activity are: anticipate the development of the instrument and provide early risk retirement of critical components, evaluate the system performances such as imaging quality parameters, straylight, ghost, polarization sensitivity and environmental influences, verify the adequacy of critical tests such as spectral characterization and straylight, define and optimize instrument alignment procedures. Following a brief overview of the FLEX mission, the paper will cover the design and the development of the optics breadboard with emphasis on the results obtained during the tests and the lessons learned for the flight unit.

  16. Integrins and epithelial cell polarity.

    Science.gov (United States)

    Lee, Jessica L; Streuli, Charles H

    2014-08-01

    Cell polarity is characterised by differences in structure, composition and function between at least two poles of a cell. In epithelial cells, these spatial differences allow for the formation of defined apical and basal membranes. It has been increasingly recognised that cell-matrix interactions and integrins play an essential role in creating epithelial cell polarity, although key gaps in our knowledge remain. This Commentary will discuss the mounting evidence for the role of integrins in polarising epithelial cells. We build a model in which both inside-out signals to polarise basement membrane assembly at the basal surface, and outside-in signals to control microtubule apical-basal orientation and vesicular trafficking are required for establishing and maintaining the orientation of epithelial cell polarity. Finally, we discuss the relevance of the basal integrin polarity axis to cancer. This article is part of a Minifocus on Establishing polarity. © 2014. Published by The Company of Biologists Ltd.

  17. Hyperon polarization: An experimental overview

    International Nuclear Information System (INIS)

    Lach, J.

    1992-12-01

    The fact that inclusively produced hyperons are produced with significant polarization was first discovered at Fermilab about seventeen years ago. This and subsequent experiments showed that Λ degree were produced polarized while bar Λ degree had no polarization in the same kinematical region. This set the stage for many experiments which showed that most hyperons are produced polarized. Recent Fermilab experiments have showed that this phenomena is even more complex than previously thought and theoretical understanding is still lacking. Nevertheless polarized hyperon beams have been an extremely useful experimental tool in measuring hyperon magnetic moments and hyperon β-decay. Recently, hyperon radiative decays have been studied and magnetic moment precession of channeled particles in bent crystals has been observed

  18. A review of polarized ion sources

    International Nuclear Information System (INIS)

    Schmor, P.W.

    1995-06-01

    The two main types of polarized ion sources in use on accelerators today are the Atomic Beam Polarized Ion Source (ABIS) source and the Optically Pumped Polarized Ion Source (OPPIS). Both types can provide beams of nuclearly polarized light ions which are either positively or negatively charged. Heavy ion polarized ion sources for accelerators are being developed. (author). 35 refs., 1 tab

  19. Promoting Diversity Through Polar Interdisciplinary Coordinated Education (Polar ICE)

    Science.gov (United States)

    McDonnell, J. D.; Hotaling, L. A.; Garza, C.; Van Dyk, P. B.; Hunter-thomson, K. I.; Middendorf, J.; Daniel, A.; Matsumoto, G. I.; Schofield, O.

    2017-12-01

    Polar Interdisciplinary Coordinated Education (ICE) is an education and outreach program designed to provide public access to the Antarctic and Arctic regions through polar data and interactions with the scientists. The program provides multi-faceted science communication training for early career scientists that consist of a face-to face workshop and opportunities to apply these skills. The key components of the scientist training workshop include cultural competency training, deconstructing/decoding science for non-expert audiences, the art of telling science stories, and networking with members of the education and outreach community and reflecting on communication skills. Scientists partner with educators to provide professional development for K-12 educators and support for student research symposia. Polar ICE has initiated a Polar Literacy initiative that provides both a grounding in big ideas in polar science and science communication training designed to underscore the importance of the Polar Regions to the public while promoting interdisciplinary collaborations between scientists and educators. Our ultimate objective is to promote STEM identity through professional development of scientists and educators while developing career awareness of STEM pathways in Polar science.

  20. [Impact of Light Polarization on the Measurement of Water Particulate Backscattering Coefficient].

    Science.gov (United States)

    Liu, Jia; Gong, Fang; He, Xian-qiang; Zhu, Qian-kun; Huang, Hai-qing

    2016-01-01

    Particulate backscattering coefficient is a main inherent optical properties (IOPs) of water, which is also a determining factor of ocean color and a basic parameter for inversion of satellite ocean color remote sensing. In-situ measurement with optical instruments is currently the main method for obtaining the particulate backscattering coefficient of water. Due to reflection and refraction by the mirrors in the instrument optical path, the emergent light source from the instrument may be partly polarized, thus to impact the measurement accuracy of water backscattering coefficient. At present, the light polarization of measuring instruments and its impact on the measurement accuracy of particulate backscattering coefficient are still poorly known. For this reason, taking a widely used backscattering coefficient measuring instrument HydroScat6 (HS-6) as an example in this paper, the polarization characteristic of the emergent light from the instrument was systematically measured, and further experimental study on the impact of the light polarization on the measurement accuracy of the particulate backscattering coefficient of water was carried out. The results show that the degree of polarization(DOP) of the central wavelength of emergent light ranges from 20% to 30% for all of the six channels of the HS-6, except the 590 nm channel from which the DOP of the emergent light is slightly low (-15%). Therefore, the emergent light from the HS-6 has significant polarization. Light polarization has non-neglectable impact on the measurement of particulate backscattering coefficient, and the impact degree varies with the wave band, linear polarization angle and suspended particulate matter (SPM) concentration. At different SPM concentrations, the mean difference caused by light polarization can reach 15.49%, 11.27%, 12.79%, 14.43%, 13.76%, and 12.46% in six bands, 420, 442, 470, 510, 590, and 670 nm, respectively. Consequently, the impact of light polarization on the

  1. The Polar BEAR magnetic field experiment

    Science.gov (United States)

    Bythrow, P. F.; Potemra, T. A.; Zanetti, L. J.; Mobley, F. F.; Scheer, L.; Radford, W. E.

    1987-09-01

    The objectives and the instrumentation of the Polar BEAR magnetic field experiment are described along with the preliminary results from simultaneous measurements of Birkeland currents and UV auroral emissions. The experiment consists of an integrated sensor head, analog electronics, and digital electronics. The sensor head is a single unit containing sensor windings for each of the three orthogonal axes, oriented parrallel to the spacecraft coordinates; to minimize interference from spacecraft-generated magnetic fields, the sensor unit is located at the end of the +y solar panel. The digital electronics package is essentially identical to that flown on HILAT. A signal processor digitizes the analog outputs of the three orthogonal axes of the flux-gate magnetometer to a 13-bit resolution, yielding a magnetic field range of + or - 63,000 nT and a resolution of 15.2 nT. The full-resolution magnetic field values are recovered by data processing techniques on the ground.

  2. Sustaining observations in the polar oceans.

    Science.gov (United States)

    Abrahamsen, E P

    2014-09-28

    Polar oceans present a unique set of challenges to sustained observations. Sea ice cover restricts navigation for ships and autonomous measurement platforms alike, and icebergs present a hazard to instruments deployed in the upper ocean and in shelf seas. However, the important role of the poles in the global ocean circulation provides ample justification for sustained observations in these regions, both to monitor the rapid changes taking place, and to better understand climate processes in these traditionally poorly sampled areas. In the past, the vast majority of polar measurements took place in the summer. In recent years, novel techniques such as miniature CTD (conductivity-temperature-depth) tags carried by seals have provided an explosion in year-round measurements in areas largely inaccessible to ships, and, as ice avoidance is added to autonomous profiling floats and gliders, these promise to provide further enhancements to observing systems. In addition, remote sensing provides vital information about changes taking place in sea ice cover at both poles. To make these observations sustainable into the future, improved international coordination and collaboration is necessary to gain optimum utilization of observing networks. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  3. POLARIZED LIGHT IN PHYSIOTHERAPY

    Directory of Open Access Journals (Sweden)

    L. D. Tondiy

    2015-12-01

    Full Text Available The data on polarized light (PS - a new promising treatment, rehabilitation and prevention, which took its deserved place among the known therapeutic physical factors and may even compete with laser radiation of low and LED therapy. It is reflected the significant contribution of domestic scientists in the study of aircraft action on the body, its introduction in the treatment, rehabilitation and prevention of grippe, ARI. These action's mechanisms of the aircraft on the electro-physiological processes in the body that have the leading role in the regulation of its life. The new moment in the study of aircraft on the body is the evidence of its positive impact on the mechanisms of self body - its different units: the disease's banning - a revitalization of the stress-protective, stress-limiting system antioxidial, detoxification and other protection systems, the formation by the body antiviral and antimicrobial specific substances (interferon and lysozyme, activation of the immune system, phagocytosis, protective functions of skin. The protective and mobilizing role of the second link is studied: which is triggered in case of occurrence of disease or preexisting diseases: PL mobilized processes of restitution, reparations, compensation, immunity and microcirculation. The authors studied the possibility of aircraft's using to enhance performance, reduce side effects of physical factors, which are often used in the treatment (electric methods, treatment by sound, fresh and mineral water, etc..

  4. Update of the Polar SWIFT model for polar stratospheric ozone loss (Polar SWIFT version 2)

    Science.gov (United States)

    Wohltmann, Ingo; Lehmann, Ralph; Rex, Markus

    2017-07-01

    The Polar SWIFT model is a fast scheme for calculating the chemistry of stratospheric ozone depletion in polar winter. It is intended for use in global climate models (GCMs) and Earth system models (ESMs) to enable the simulation of mutual interactions between the ozone layer and climate. To date, climate models often use prescribed ozone fields, since a full stratospheric chemistry scheme is computationally very expensive. Polar SWIFT is based on a set of coupled differential equations, which simulate the polar vortex-averaged mixing ratios of the key species involved in polar ozone depletion on a given vertical level. These species are O3, chemically active chlorine (ClOx), HCl, ClONO2 and HNO3. The only external input parameters that drive the model are the fraction of the polar vortex in sunlight and the fraction of the polar vortex below the temperatures necessary for the formation of polar stratospheric clouds. Here, we present an update of the Polar SWIFT model introducing several improvements over the original model formulation. In particular, the model is now trained on vortex-averaged reaction rates of the ATLAS Chemistry and Transport Model, which enables a detailed look at individual processes and an independent validation of the different parameterizations contained in the differential equations. The training of the original Polar SWIFT model was based on fitting complete model runs to satellite observations and did not allow for this. A revised formulation of the system of differential equations is developed, which closely fits vortex-averaged reaction rates from ATLAS that represent the main chemical processes influencing ozone. In addition, a parameterization for the HNO3 change by denitrification is included. The rates of change of the concentrations of the chemical species of the Polar SWIFT model are purely chemical rates of change in the new version, whereas in the original Polar SWIFT model, they included a transport effect caused by the

  5. Polarized light imaging of birefringence and diattenuation at high resolution and high sensitivity

    International Nuclear Information System (INIS)

    Mehta, Shalin B; Shribak, Michael; Oldenbourg, Rudolf

    2013-01-01

    Polarized light microscopy provides unique opportunities for analyzing the molecular order in man-made and natural materials, including biological structures inside living cells, tissues, and whole organisms. 20 years ago, the LC-PolScope was introduced as a modern version of the traditional polarizing microscope enhanced by liquid crystal devices for the control of polarization, and by electronic imaging and digital image processing for fast and comprehensive image acquisition and analysis. The LC-PolScope is commonly used for birefringence imaging, analyzing the spatial and temporal variations of the differential phase delay in ordered and transparent materials. Here we describe an alternative use of the LC-PolScope for imaging the polarization dependent transmittance of dichroic materials. We explain the minor changes needed to convert the instrument between the two imaging modes, discuss the relationship between the quantities measured with each instrument, and touch on the physical connection between refractive index, birefringence, transmittance, diattenuation, and dichroism. (special issue article)

  6. Reactor instrumentation and control

    International Nuclear Information System (INIS)

    Wach, D.; Beraha, D.

    1980-01-01

    The methods for measuring radiation are shortly reviewed. The instrumentation for neutron flux measurement is classified into out-of-core and in-core instrumentation. The out-of-core instrumentation monitors the operational range from the subcritical reactor to full power. This large range is covered by several measurement channels which derive their signals from counter tubes and ionization chambers. The in-core instrumentation provides more detailed information on the power distribution in the core. The self-powered neutron detectors and the aeroball system in PWR reactors are discussed. Temperature and pressure measurement devices are briefly discussed. The different methods for leak detection are described. In concluding the plant instrumentation part some new monitoring systems and analysis methods are presented: early failure detection methods by noise analysis, acoustic monitoring and vibration monitoring. The presentation of the control starts from an qualitative assessment of the reactor dynamics. The chosen control strategy leads to the definition of the part-load diagram, which provides the set-points for the different control systems. The tasks and the functions of these control systems are described. In additiion to the control, a number of limiting systems is employed to keep the reactor in a safe operating region. Finally, an outlook is given on future developments in control, concerning mainly the increased application of process computers. (orig./RW)

  7. Instrumental analysis, second edition

    International Nuclear Information System (INIS)

    Christian, G.D.; O'Reilly, J.E.

    1988-01-01

    The second edition of Instrumental Analysis is a survey of the major instrument-based methods of chemical analysis. It appears to be aimed at undergraduates but would be equally useful in a graduate course. The volume explores all of the classical quantitative methods and contains sections on techniques that usually are not included in a semester course in instrumentation (such as electron spectroscopy and the kinetic methods). Adequate coverage of all of the methods contained in this book would require several semesters of focused study. The 25 chapters were written by different authors, yet the style throughout the book is more uniform than in the earlier edition. With the exception of a two-chapter course in analog and digital circuits, the book purports to de-emphasize instrumentation, focusing more on the theory behind the methods and the application of the methods to analytical problems. However, a detailed analysis of the instruments used in each method is by no means absent. The book has the favor of a user's guide to analysis

  8. Instrumentation for environmental monitoring

    International Nuclear Information System (INIS)

    McLaughlin, R.D.; Hunt, M.S.; Murphy, D.L.; Chen, C.R.

    1979-06-01

    In the last few years a much greater emphasis has been placed upon understanding, controlling and monitoring the environmental effects of the advancing technologies. This has resulted in rapid advances in techniques for environmental monitoring. To aid the concerned scientist in keeping abreast of these developments, the Lawrence Berkeley Laboratory publishes a collection of volumes entitled Instrumentation for Environmental Monitoring. Separated into four volumes covering four media, AIR, WATER, RADIATION, and BIOMEDICAL, they provide a source book for three types of material: (1) Monitoring Rationale. They describe the characteristics, forms, and effects of a wide variety of pollutants and the means of controlling them. Federal regulations are explained and summarized. (2) Analytical Techniques. Methods of determining specific pollutants are described with special emphasis on the principles that form the basis of instrumental methods. (3) Commercial Instrumentation. The features of most commercially available instrumentation used for the determination and monitoring of each pollutant are presented in a manner that facilitates instrumental comparisons. Examples of the types of material in the volumes and the use of the volumes are presented

  9. Nuclear physics with polarized particles

    CERN Document Server

    Paetz gen Schieck, Hans

    2012-01-01

    The measurement of spin-polarization observables in reactions of nuclei and particles is of great utility and advantage when the effects of single-spin sub-states are to be investigated. Indeed, the unpolarized differential cross-section encompasses the averaging over the spin states of the particles, and thus loses details of the interaction process. This introductory text combines, in a single volume, course-based lecture notes on spin physics and on polarized-ion sources with the aim of providing a concise yet self-contained starting point for newcomers to the field, as well as for lecturers in search of suitable material for their courses and seminars. A significant part of the book is devoted to introducing the formal theory-a description of polarization and of nuclear reactions with polarized particles. The remainder of the text describes the physical basis of methods and devices necessary to perform experiments with polarized particles and to measure polarization and polarization effects in nuclear rea...

  10. Circular polarization of light by planet Mercury and enantiomorphism of its surface minerals.

    Science.gov (United States)

    Meierhenrich, Uwe J; Thiemann, Wolfram H P; Barbier, Bernard; Brack, André; Alcaraz, Christian; Nahon, Laurent; Wolstencroft, Ray

    2002-04-01

    Different mechanisms for the generation of circular polarization by the surface of planets and satellites are described. The observed values for Venus, the Moon, Mars, and Jupiter obtained by photo-polarimetric measurements with Earth based telescopes, showed accordance with theory. However, for planet Mercury asymmetric parameters in the circular polarization were measured that do not fit with calculations. For BepiColombo, the ESA cornerstone mission 5 to Mercury, we propose to investigate this phenomenon using a concept which includes two instruments. The first instrument is a high-resolution optical polarimeter, capable to determine and map the circular polarization by remote scanning of Mercury's surface from the Mercury Planetary Orbiter MPO. The second instrument is an in situ sensor for the detection of the enantiomorphism of surface crystals and minerals, proposed to be included in the Mercury Lander MSE.

  11. Biochemistry Instrumentation Core Technology Center

    Data.gov (United States)

    Federal Laboratory Consortium — The UCLA-DOE Biochemistry Instrumentation Core Facility provides the UCLA biochemistry community with easy access to sophisticated instrumentation for a wide variety...

  12. Heat Flux Instrumentation Laboratory (HFIL)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Heat Flux Instrumentation Laboratory is used to develop advanced, flexible, thin film gauge instrumentation for the Air Force Research Laboratory....

  13. Few-body experiments with polarized beams and polarized targets

    International Nuclear Information System (INIS)

    Simmons, J.E.

    1983-01-01

    A survey is presented concerning recent polarization experiments in the elastic p-d, p- 3 He, and p- 4 He systems. Mention is made of selected neutron experiments. The nominal energy range is 10 to 1000 MeV. Recent results and interpretations of the p-d system near 10 MeV are discussed. New experiments on the energy dependence of back angle p-d tensor polarization are discussed with respect to resolution of discrepancies and difficulty of theoretical interpretation. Progress is noted concerning multiple scattering interpretation of forward p-d deuteron polarization. Some new results are presented concerning the p- 3 He system and higher energy p- 4 He polarization experiments. 52 references

  14. Instrumentation Video Systems

    Science.gov (United States)

    Lida, Hitoshi

    1981-10-01

    The use of video equipment as instrumentation has been increasing steadily over the past decade. An indication of this trend can be found close to home: notice how rapidly the number of television (TV) displays has grown at our technical exhibits. It is this exhibited equipment and other equipment like it which form the subject of this summary. We will limit our discussions to readily available hardware (and a little software) and leave reports of the leading edge development work to other issues of this journal. We hope, in this manner, to present useful information to those who need to apply video to their instrumen-tation problems now. Along the way we will occasionally indicate what equipment might soon result from current research, but our clear emphasis will be on the state of the art of accessible instrumentation video.

  15. The IKARUS instrument

    International Nuclear Information System (INIS)

    Gerster, H.J.; Stein, G.

    1994-01-01

    When the Federal Government decided on a 25% reduction of CO 2 emissions till 2005 in 1990 the necessity resulted that an instrument has to be developed for the analysis and assessment of the ecological, economic and energetic impact of different reduction strategies. The development task was awarded by the BMFT to the Research Centre Juelich in cooperation with well-known institutions of energy system research. The total instrument is scheduled to be finished by the end of 1994. For the decentral use of the instrument by a wide specialist public the developed models and data banks which are equipped with a user-friendly surface are suited for larger PCs (486, 16 MB RAM/500-1000 MB ROM). (orig.) [de

  16. Calibration of Geodetic Instruments

    Directory of Open Access Journals (Sweden)

    Marek Bajtala

    2005-06-01

    Full Text Available The problem of metrology and security systems of unification, correctness and standard reproducibilities belong to the preferred requirements of theory and technical practice in geodesy. Requirements on the control and verification of measured instruments and equipments increase and the importance and up-to-date of calibration get into the foreground. Calibration possibilities of length-scales (of electronic rangefinders and angle-scales (of horizontal circles of geodetic instruments. Calibration of electronic rangefinders on the linear comparative baseline in terrain. Primary standard of planar angle – optical traverse and its exploitation for calibration of the horizontal circles of theodolites. The calibration equipment of the Institute of Slovak Metrology in Bratislava. The Calibration process and results from the calibration of horizontal circles of selected geodetic instruments.

  17. Aethalometer™ Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, Arthur J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-04-01

    The Aethalometer is an instrument that provides a real-time readout of the concentration of “Black” or “Elemental” carbon aerosol particles (BC or E) in an air stream (see Figure 1 and Figure 2). It is a self-contained instrument that measures the rate of change of optical transmission through a spot on a filter where aerosol is being continuously collected and uses the information to calculate the concentration of optically absorbing material in the sampled air stream. The instrument measures the transmitted light intensities through the “sensing” portion of the filter, on which the aerosol spot is being collected, and a “reference” portion of the filter as a check on the stability of the optical source. A mass flowmeter monitors the sample air flow rate. The data from these three measurements is used to determine the mean BC content of the air stream.

  18. ISSUERS OF FINANCIAL INSTRUMENTS

    Directory of Open Access Journals (Sweden)

    Cristian GHEORGHE

    2016-05-01

    Full Text Available The rules laid down by Romanian Capital Market Law and the regulations put in force for its implementation apply to issuers of financial instruments admitted to trading on the regulated market established in Romania. But the issuers remain companies incorporated under Company Law of 1990. Such dual regulations need increased attention in order to observe the legal status of the issuers/companies and financial instruments/shares. Romanian legislator has chosen to implement in Capital Market Law special rules regarding the administration of the issuers of financial instruments, not only rules regarding admitting and maintaining to a regulated market. Thus issuers are, in Romanian Law perspective, special company that should comply special rule regarding board of administration and general shareholders meeting.

  19. Extreme-scale alignments of quasar optical polarizations and Galactic dust contamination

    OpenAIRE

    Pelgrims, Vincent

    2017-01-01

    Almost twenty years ago the optical polarization vectors from quasars were shown to be aligned over extreme-scales. That evidence was later confirmed and enhanced thanks to additional optical data obtained with the ESO instrument FORS2 mounted on the VLT, in Chile. These observations suggest either Galactic foreground contamination of the data or, more interestingly, a cosmological origin. Using 353-GHz polarization data from the Planck satellite, I recently showed that the main features of t...

  20. Mechanisms of Cell Polarity-Controlled Epithelial Homeostasis and Immunity in the Intestine.

    Science.gov (United States)

    Klunder, Leon J; Faber, Klaas Nico; Dijkstra, Gerard; van IJzendoorn, Sven C D

    2017-07-05

    Intestinal epithelial cell polarity is instrumental to maintain epithelial homeostasis and balance communications between the gut lumen and bodily tissue, thereby controlling the defense against gastrointestinal pathogens and maintenance of immune tolerance to commensal bacteria. In this review, we highlight recent advances with regard to the molecular mechanisms of cell polarity-controlled epithelial homeostasis and immunity in the human intestine. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  1. Applications of circularly polarized photons at the ALS with a bend magnet source

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    The purpose of this workshop is to focus attention on, and to stimulate the scientific exploitation of, the natural polarization properties of bend-magnet synchrotron radiation at the ALS -- for research in biology, materials science, physics, and chemistry. The topics include: The Advanced Light Source; Magnetic Circular Dichroism and Differential Scattering on Biomolecules; Tests of Fundamental Symmetries; High {Tc} Superconductivity; Photoemission from Magnetic and Non-magnetic Solids; Studies of Highly Correlated Systems; and Instrumentation for Photon Transport and Polarization Measurements.

  2. Elite Polarization and Public Opinion

    DEFF Research Database (Denmark)

    Robison, Joshua; Mullinix, Kevin

    2016-01-01

    Elite polarization has reshaped American politics and is an increasingly salient aspect of news coverage within the United States. As a consequence, a burgeoning body of research attempts to unravel the effects of elite polarization on the mass public. However, we know very little about how...... attitudes. In our first study, we show that criticism of polarization leads partisans to more positively evaluate the argument offered by their non-preferred party, increases support for bi-partisanship, but ultimately does not change the extent to which partisans follow their party’s policy endorsements...

  3. Acceleration of polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1998-01-01

    The acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial Siberian snake and a rf dipole that ensure stable adiabatic spin motion during acceleration has made it possible to accelerate polarized protons to 25 GeV at the Brookhaven AGS. Full Siberian snakes are being developed for RHIC to make the acceleration of polarized protons to 250 GeV possible. A similar scheme is being studied for the 800 GeV HERA proton accelerator

  4. Polarimetry with azimuthally polarized light

    Science.gov (United States)

    de Sande, Juan Carlos González; Piquero, Gemma; Santarsiero, Massimo

    2018-03-01

    Nonuniformly polarized light can be used for Mueller polarimetry of homogeneous linear samples. In this work, a set up based on using azimuthally polarized input light and a modified commercial light polarimeter is proposed and developed. With this set up, a Mueller submatrix of a sample can be obtained by measuring the Stokes parameters at only three different positions across the output beam section. Symmetry constraints for linear deterministic samples allow the complete Mueller matrix to be deduced for this kind of specimens. The experimental results obtained for phase plates and for a linear polarizer confirm the validity of the proposed method.

  5. Polarized deuteron elastic scattering from a polarized proton target

    International Nuclear Information System (INIS)

    Schmelzer, R.; Kuiper, H.; Schoeberl, M.; Berber, S.; Hilmert, H.; Koeppel, R.; Pferdmenges, R.; Zankel, H.

    1983-01-01

    Measurements are reported of the spin correlation parameter Cy,y for the elastic scattering of 10.0 MeV vector polarized deuterons from a polarized proton target at five CM angles (76 0 ,85 0 ,98 0 ,115 0 ,132 0 ). The experimental results are compared with different predictions. A Faddeev type calculation on the basis of local potentials also including approximate Coulomb distortion is favoured by our experimental results. (orig.)

  6. PolarHub: A Global Hub for Polar Data Discovery

    Science.gov (United States)

    Li, W.

    2014-12-01

    This paper reports the outcome of a NSF project in developing a large-scale web crawler PolarHub to discover automatically the distributed polar dataset in the format of OGC web services (OWS) in the cyberspace. PolarHub is a machine robot; its goal is to visit as many webpages as possible to find those containing information about polar OWS, extract this information and store it into the backend data repository. This is a very challenging task given huge data volume of webpages on the Web. Three unique features was introduced in PolarHub to make it distinctive from earlier crawler solutions: (1) a multi-task, multi-user, multi-thread support to the crawling tasks; (2) an extensive use of thread pool and Data Access Object (DAO) design patterns to separate persistent data storage and business logic to achieve high extendibility of the crawler tool; (3) a pattern-matching based customizable crawling algorithm to support discovery of multi-type geospatial web services; and (4) a universal and portable client-server communication mechanism combining a server-push and client pull strategies for enhanced asynchronous processing. A series of experiments were conducted to identify the impact of crawling parameters to the overall system performance. The geographical distribution pattern of all PolarHub identified services is also demonstrated. We expect this work to make a major contribution to the field of geospatial information retrieval and geospatial interoperability, to bridge the gap between data provider and data consumer, and to accelerate polar science by enhancing the accessibility and reusability of adequate polar data.

  7. Virtual Sensor Test Instrumentation

    Science.gov (United States)

    Wang, Roy

    2011-01-01

    Virtual Sensor Test Instrumentation is based on the concept of smart sensor technology for testing with intelligence needed to perform sell-diagnosis of health, and to participate in a hierarchy of health determination at sensor, process, and system levels. A virtual sensor test instrumentation consists of five elements: (1) a common sensor interface, (2) microprocessor, (3) wireless interface, (4) signal conditioning and ADC/DAC (analog-to-digital conversion/ digital-to-analog conversion), and (5) onboard EEPROM (electrically erasable programmable read-only memory) for metadata storage and executable software to create powerful, scalable, reconfigurable, and reliable embedded and distributed test instruments. In order to maximize the efficient data conversion through the smart sensor node, plug-and-play functionality is required to interface with traditional sensors to enhance their identity and capabilities for data processing and communications. Virtual sensor test instrumentation can be accessible wirelessly via a Network Capable Application Processor (NCAP) or a Smart Transducer Interlace Module (STIM) that may be managed under real-time rule engines for mission-critical applications. The transducer senses the physical quantity being measured and converts it into an electrical signal. The signal is fed to an A/D converter, and is ready for use by the processor to execute functional transformation based on the sensor characteristics stored in a Transducer Electronic Data Sheet (TEDS). Virtual sensor test instrumentation is built upon an open-system architecture with standardized protocol modules/stacks to interface with industry standards and commonly used software. One major benefit for deploying the virtual sensor test instrumentation is the ability, through a plug-and-play common interface, to convert raw sensor data in either analog or digital form, to an IEEE 1451 standard-based smart sensor, which has instructions to program sensors for a wide variety of

  8. Interfacing to accelerator instrumentation

    International Nuclear Information System (INIS)

    Shea, T.J.

    1995-01-01

    As the sensory system for an accelerator, the beam instrumentation provides a tremendous amount of diagnostic information. Access to this information can vary from periodic spot checks by operators to high bandwidth data acquisition during studies. In this paper, example applications will illustrate the requirements on interfaces between the control system and the instrumentation hardware. A survey of the major accelerator facilities will identify the most popular interface standards. The impact of developments such as isochronous protocols and embedded digital signal processing will also be discussed

  9. Spectroelectrochemical Instrument Measures TOC

    Science.gov (United States)

    Kounaves, Sam

    2011-01-01

    A spectroelectrochemical instrument has been developed for measuring the total organic carbon (TOC) content of an aqueous solution. Measurements of TOC are frequently performed in environmental, clinical, and industrial settings. Until now, techniques for performing such measurements have included, various ly, the use of hazardous reagents, ultraviolet light, or ovens, to promote reactions in which the carbon contents are oxidized. The instrument now being developed is intended to be a safer, more economical means of oxidizing organic carbon and determining the TOC levels of aqueous solutions and for providing a low power/mass unit for use in planetary missions.

  10. Standard NIM instrumentation system

    CERN Document Server

    1990-01-01

    NIM is a standard modular instrumentation system that is in wide use throughout the world. As the NIM system developed and accommodations were made to a dynamic instrumentation field and a rapidly advancing technology, additions, revisions and clarifications were made. These were incorporated into the standard in the form of addenda and errata. This standard is a revision of the NIM document, AEC Report TID- 20893 (Rev 4) dated July 1974. It includes all the addenda and errata items that were previously issued as well as numerous additional items to make the standard current with modern technology and manufacturing practice.

  11. Instrumentation Cables Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Muna, Alice Baca [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); LaFleur, Chris Bensdotter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-10-01

    A fire at a nuclear power plant (NPP) has the potential to damage structures, systems, and components important to safety, if not promptly detected and suppressed. At Browns Ferry Nuclear Power Plant on March 22, 1975, a fire in the reactor building damaged electrical power and control systems. Damage to instrumentation cables impeded the function of both normal and standby reactor coolant systems, and degraded the operators’ plant monitoring capability. This event resulted in additional NRC involvement with utilities to ensure that NPPs are properly protected from fire as intended by the NRC principle design criteria (i.e., general design criteria 3, Fire Protection). Current guidance and methods for both deterministic and performance based approaches typically make conservative (bounding) assumptions regarding the fire-induced failure modes of instrumentation cables and those failure modes effects on component and system response. Numerous fire testing programs have been conducted in the past to evaluate the failure modes and effects of electrical cables exposed to severe thermal conditions. However, that testing has primarily focused on control circuits with only a limited number of tests performed on instrumentation circuits. In 2001, the Nuclear Energy Institute (NEI) and the Electric Power Research Institute (EPRI) conducted a series of cable fire tests designed to address specific aspects of the cable failure and circuit fault issues of concern1. The NRC was invited to observe and participate in that program. The NRC sponsored Sandia National Laboratories to support this participation, whom among other things, added a 4-20 mA instrumentation circuit and instrumentation cabling to six of the tests. Although limited, one insight drawn from those instrumentation circuits tests was that the failure characteristics appeared to depend on the cable insulation material. The results showed that for thermoset insulated cables, the instrument reading tended to drift

  12. Inspector-instrument interface in portable NDA instrumentation

    International Nuclear Information System (INIS)

    Halbig, J.K.; Klosterbuer, S.F.

    1981-01-01

    Recent electronics technology advances make it possible to design sophisticated instruments in small packages for convenient field implementation. This report describes an inspector-instrument interface design which allows communication of procedures, responses, and results between the instrument and user. The interface has been incorporated into new spent-fuel instrumentation and a battery-powered multichannel analyzer

  13. Design of 40M SANS instrument at HANARO, Korea

    International Nuclear Information System (INIS)

    Han, Young-Soo; Choi, Sung-Min; Kim, Tae-Hwan; Lee, Chang-Hee; Kim, Hark-Rho

    2006-01-01

    The HANARO cold-neutron research facility project was launched on July 1, 2003. A state of the art SANS instrument was selected as a top-priority instrument by an instrument selection committee, which consisted of domestic users and HANARO personnel. An instrument development team and an international and domestic instrument advisory team were formulated. At the end position of the CG1B guide, 40M SANS will be installed in the cold-neutron guide hall. The guide and the instrument simulation were performed using Vitess software and the optimum conceptual design was completed based on the simulation results and the international advisory team reviews. The 100x100 cm 2 area detector will be installed and the sample-to-detector distance will vary from 1 to 20 m. The refractive focusing optics and the transmission polarizer/spin flipper setup is planned for installation. The Q range of the 40M SANS instrument will cover from 0.0008 to 1.0 A -1 when considering the refractive focusing optics. In this paper, the simulation results and the design of the new 40M SANS instrument are presented

  14. Design of 40M SANS instrument at HANARO, Korea

    Energy Technology Data Exchange (ETDEWEB)

    Han, Young-Soo [Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejon 305-600 (Korea, Republic of)]. E-mail: yshan@kaeri.re.kr; Choi, Sung-Min [Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong, Daejon 305-701 (Korea, Republic of); Kim, Tae-Hwan [Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong, Daejon 305-701 (Korea, Republic of); Lee, Chang-Hee [Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejon 305-600 (Korea, Republic of); Kim, Hark-Rho [Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejon 305-600 (Korea, Republic of)

    2006-11-15

    The HANARO cold-neutron research facility project was launched on July 1, 2003. A state of the art SANS instrument was selected as a top-priority instrument by an instrument selection committee, which consisted of domestic users and HANARO personnel. An instrument development team and an international and domestic instrument advisory team were formulated. At the end position of the CG1B guide, 40M SANS will be installed in the cold-neutron guide hall. The guide and the instrument simulation were performed using Vitess software and the optimum conceptual design was completed based on the simulation results and the international advisory team reviews. The 100x100 cm{sup 2} area detector will be installed and the sample-to-detector distance will vary from 1 to 20 m. The refractive focusing optics and the transmission polarizer/spin flipper setup is planned for installation. The Q range of the 40M SANS instrument will cover from 0.0008 to 1.0 A{sup -1} when considering the refractive focusing optics. In this paper, the simulation results and the design of the new 40M SANS instrument are presented.

  15. Polar source analysis : technical memorandum

    Science.gov (United States)

    2017-09-29

    The following technical memorandum describes the development, testing and analysis of various polar source data sets. The memorandum also includes recommendation for potential inclusion in future releases of AEDT. This memorandum is the final deliver...

  16. Anodic Concentration Polarization in SOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Williford, Rick E.; Chick, Lawrence A.; Maupin, Gary D.; Simner, Steve P.; Stevenson, Jeffry W.; Khaleel, Mohammad A.; Wachsman, ED, et al

    2003-08-01

    Concentration polarization is important because it determines the maximum power output of a solid oxide fuel cell (SOFC) at high fuel utilization. Anodic concentration polarization occurs when the demand for reactants exceeds the capacity of the porous ceramic anode to supply them by gas diffusion mechanisms. High tortuosities (bulk diffusion resistances) are often assumed to explain this behavior. However, recent experiments show that anodic concentration polarization originates in the immediate vicinity of the reactive triple phase boundary (TPB) sites near the anode/electrolyte interface. A model is proposed to describe how concentration polarization is controlled by two localized phenomena: competitive adsorption of reactants in areas adjacent to the reactive TPB sites, followed by relatively slow surface diffusion to the reactive sites. Results suggest that future SOFC design improvements should focus on optimization of the reactive area, adsorption, and surface diffusion at the anode/electrolyte interface.

  17. The definition of cross polarization

    DEFF Research Database (Denmark)

    Ludwig, Arthur

    1973-01-01

    There are at least three different definitions of cross polarization used in the literature. The alternative definitions are discussed with respect to several applications, and the definition which corresponds to one standard measurement practice is proposed as the best choice....

  18. Dynamic elections and ideological polarization

    Czech Academy of Sciences Publication Activity Database

    Nunnari, S.; Zápal, Jan

    2017-01-01

    Roč. 25, č. 4 (2017), s. 505-534 ISSN 1047-1987 Institutional support: Progres-Q24 Keywords : elections * political polarization Subject RIV: AH - Economics OBOR OECD: Economic Theory Impact factor: 3.361, year: 2016

  19. Dynamic elections and ideological polarization

    Czech Academy of Sciences Publication Activity Database

    Nunnari, S.; Zápal, Jan

    2017-01-01

    Roč. 25, č. 4 (2017), s. 505-534 ISSN 1047-1987 Institutional support: RVO:67985998 Keywords : elections * political polarization Subject RIV: AH - Economics OBOR OECD: Economic Theory Impact factor: 3.361, year: 2016

  20. Polarization at LEP. Vol. 2

    International Nuclear Information System (INIS)

    Alexander, G.; Altarelli, G.; Blondel, A.; Coignet, G.; Keil, E.; Plane, D.E.; Treille, D.

    1988-01-01

    This report contains a collection of papers covering the most important part of studies carried out by five study groups in view of a programme of experiments with polarized beams at LEP, the Large Electron-Positron collider under construction at CERN. The emphasis is on precision measurements at the Z peak. Such measurements are shown to be of considerable theoretical interest as well as very clean from the point of view of theoretical and experimental uncertainties. The measurement of the beam polarization can certainly be performed with sufficient accuracy, thanks to the availability of both e + and e - beam polarization. The normalization of the data taken with different beam helicities poses certain constraints that are described. Substantial progress has been made in understanding the possibility of providing longitudinally polarized beams in the LEP machine: The design of new wigglers and spin rotators, the study of correction procedures and results of numerical simulations are presented. (orig.)

  1. Mechanical writing of ferroelectric polarization.

    Science.gov (United States)

    Lu, H; Bark, C-W; Esque de los Ojos, D; Alcala, J; Eom, C B; Catalan, G; Gruverman, A

    2012-04-06

    Ferroelectric materials are characterized by a permanent electric dipole that can be reversed through the application of an external voltage, but a strong intrinsic coupling between polarization and deformation also causes all ferroelectrics to be piezoelectric, leading to applications in sensors and high-displacement actuators. A less explored property is flexoelectricity, the coupling between polarization and a strain gradient. We demonstrate that the stress gradient generated by the tip of an atomic force microscope can mechanically switch the polarization in the nanoscale volume of a ferroelectric film. Pure mechanical force can therefore be used as a dynamic tool for polarization control and may enable applications in which memory bits are written mechanically and read electrically.

  2. Mechanical Writing of Ferroelectric Polarization

    Science.gov (United States)

    Lu, H.; Bark, C.-W.; Esque de los Ojos, D.; Alcala, J.; Eom, C. B.; Catalan, G.; Gruverman, A.

    2012-04-01

    Ferroelectric materials are characterized by a permanent electric dipole that can be reversed through the application of an external voltage, but a strong intrinsic coupling between polarization and deformation also causes all ferroelectrics to be piezoelectric, leading to applications in sensors and high-displacement actuators. A less explored property is flexoelectricity, the coupling between polarization and a strain gradient. We demonstrate that the stress gradient generated by the tip of an atomic force microscope can mechanically switch the polarization in the nanoscale volume of a ferroelectric film. Pure mechanical force can therefore be used as a dynamic tool for polarization control and may enable applications in which memory bits are written mechanically and read electrically.

  3. ACCURATE POLARIZATION CALIBRATION AT 800 MHz WITH THE GREEN BANK TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Yu-Wei; Chang, Tzu-Ching; Kuo, Cheng-Yu [Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astro-Math Building, AS/NTU, 1 Roosevelt Road Sec. 4, Taipei 10617, Taiwan (China); Masui, Kiyoshi Wesley [Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 (Canada); Oppermann, Niels; Pen, Ue-Li [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto ON, M5S 3H8 (Canada); Peterson, Jeffrey B., E-mail: ywliao@asiaa.sinica.edu.tw [McWilliams Center for Cosmology, Carnegie Mellon University, Department of Physics, 5000 Forbes Avenue, Pittsburgh PA 15213 (United States)

    2016-12-20

    Polarization leakage of foreground synchrotron emission is a critical issue in H i intensity mapping experiments. While the sought-after H i emission is unpolarized, polarized foregrounds such as Galactic and extragalactic synchrotron radiation, if coupled with instrumental impurity, can mimic or overwhelm the H i signals. In this paper, we present the methodology for polarization calibration at 700–900 MHz, applied on data obtained from the Green Bank Telescope (GBT). We use astrophysical sources, both polarized and unpolarized sources including quasars and pulsars, as calibrators to characterize the polarization leakage and control systematic effects in our GBT H i intensity mapping project. The resulting fractional errors on polarization measurements on boresight are well controlled to within 0.6%–0.8% of their total intensity. The polarized beam patterns are measured by performing spider scans across both polarized quasars and pulsars. A dominant Stokes I to V leakage feature and secondary features of Stokes I to Q and I to U leakages in the 700–900 MHz frequency range are identified. These characterizations are important for separating foreground polarization leakage from the H i 21 cm signal.

  4. Detecting Changing Polarization Structures in Sagittarius A* with High Frequency VLBI

    Science.gov (United States)

    Fish, Vincent L.; Doeleman, Sheperd S.; Broderick, Avery E.; Loeb, Abraham; Rogers, Alan E. E.

    2009-12-01

    Sagittarius A* is the source of near infrared, X-ray, radio, and (sub)millimeter emission associated with the supermassive black hole at the Galactic Center. In the submillimeter regime, Sgr A* exhibits time-variable linear polarization on timescales corresponding to errors. Although the source-integrated linear polarization fraction in the models is typically only a few percent, the linear polarization fraction on small angular scales can be much higher, enabling the detection of changes in the polarimetric structure of Sgr A* on a wide variety of baselines. The shortest baselines track the source-integrated linear polarization fraction, while longer baselines are sensitive to polarization substructures that are beam-diluted by connected-element interferometry. The detection of periodic variability in source polarization should not be significantly affected even if instrumental polarization terms cannot be calibrated out. As more antennas are included in the (sub)millimeter-VLBI array, observations with full polarization will provide important new diagnostics to help disentangle intrinsic source polarization from Faraday rotation effects in the accretion and outflow region close to the black hole event horizon.

  5. Modeling optical and UV polarization of AGNs. IV. Polarization timing

    Science.gov (United States)

    Rojas Lobos, P. A.; Goosmann, R. W.; Marin, F.; Savić, D.

    2018-03-01

    Context. Optical observations cannot resolve the structure of active galactic nuclei (AGN), and a unified model for AGN was inferred mostly from indirect methods, such as spectroscopy and variability studies. Optical reverberation mapping allowed us to constrain the spatial dimension of the broad emission line region and thereby to measure the mass of supermassive black holes. Recently, reverberation was also applied to the polarized signal emerging from different AGN components. In principle, this should allow us to measure the spatial dimensions of the sub-parsec reprocessing media. Aim. We conduct numerical modeling of polarization reverberation and provide theoretical predictions for the polarization time lag induced by different AGN components. The model parameters are adjusted to the observational appearance of the Seyfert 1 galaxy NGC 4151. Methods: We modeled scattering-induced polarization and tested different geometries for the circumnuclear dust component. Our tests included the effects of clumpiness and different dust prescriptions. To further extend the model, we also explored the effects of additional ionized winds stretched along the polar direction, and of an equatorial scattering ring that is responsible for the polarization angle observed in pole-on AGN. The simulations were run using a time-dependent version of the STOKES code. Results: Our modeling confirms the previously found polarization characteristics as a function of the observer`s viewing angle. When the dust adopts a flared-disk geometry, the lags reveal a clear difference between type 1 and type 2 AGN. This distinction is less clear for a torus geometry where the time lag is more sensitive to the geometry and optical depth of the inner surface layers of the funnel. The presence of a scattering equatorial ring and ionized outflows increased the recorded polarization time lags, and the polar outflows smooths out dependence on viewing angle, especially for the higher optical depth of the

  6. Integrating Nephelometer Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Uin, J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-03-01

    The Integrating Nephelometer (Figure 1) is an instrument that measures aerosol light scattering. It measures aerosol optical scattering properties by detecting (with a wide angular integration – from 7 to 170°) the light scattered by the aerosol and subtracting the light scattered by the carrier gas, the instrument walls and the background noise in the detector (zeroing). Zeroing is typically performed for 5 minutes every day at midnight UTC. The scattered light is split into red (700 nm), green (550 nm), and blue (450 nm) wavelengths and captured by three photomultiplier tubes. The instrument can measure total scatter as well as backscatter only (from 90 to 170°) (Heintzenberg and Charlson 1996; Anderson et al. 1996; Anderson and Ogren 1998; TSI 3563 2015) At ARM (Atmospheric Radiation Measurement), two identical Nephelometers are usually run in series with a sample relative humidity (RH) conditioner between them. This is possible because Nephelometer sampling is non-destructive and the sample can be passed on to another instrument. The sample RH conditioner scans through multiple RH values in cycles, treating the sample. This kind of setup allows to study how aerosol particles’ light scattering properties are affected by humidification (Anderson et al. 1996). For historical reasons, the two Nephelometers in this setup are labeled “wet” and “dry”, with the “dry” Nephelometer usually being the one before the conditioner and sampling ambient air (the names are switched for the MAOS measurement site due to the high RH of the ambient air).

  7. AC resistance measuring instrument

    Science.gov (United States)

    Hof, P.J.

    1983-10-04

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument. 8 figs.

  8. Measurement and Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Kirkham, Harold

    2018-01-02

    This is a chapter for a book called the Standard Handbook for Electrical Engineering. Though it is not obvious from the title, the book deals mainly with power engineering. The first chapter (not mine) is about the fundamental quantities used in measurement. This chapter is about the process and the instrumentation.

  9. Instruments for Everyone.

    Science.gov (United States)

    Perkins-Bosarge, Sarah

    1998-01-01

    Thanks to an entrepreneurial principal, nearly 75% of a rural New York State school's upper-division students participate in band. To ensure access, the principal bargains with second-hand dealers for instruments (using fees from photo profits) and charges kids a fee of $1 to $15 yearly. Consulting with the music teacher avoids duplication and…

  10. Economic Policy Instruments

    DEFF Research Database (Denmark)

    Klemmensen, Børge

    2007-01-01

    Økonomiske instrumenter begrundes med behovet for politiske indgreb, der muliggør internaliseringen af omkostningerne ved de miljøpåvirkninger, produktion and levevis afstedkommer, således at hensyntagen til miljøet bliver en del af virksomheders og husholdningers omkostninger og dermed en tilsky...

  11. Designing Intelligent Instruments

    Science.gov (United States)

    Knuth, Kevin H.; Erner, Philip M.; Frasso, Scott

    2007-11-01

    Remote science operations require automated systems that can both act and react with minimal human intervention. One such vision is that of an intelligent instrument that collects data in an automated fashion, and based on what it learns, decides which new measurements to take. This innovation implements experimental design and unites it with data analysis in such a way that it completes the cycle of learning. This cycle is the basis of the Scientific Method. The three basic steps of this cycle are hypothesis generation, inquiry, and inference. Hypothesis generation is implemented by artificially supplying the instrument with a parameterized set of possible hypotheses that might be used to describe the physical system. The act of inquiry is handled by an inquiry engine that relies on Bayesian adaptive exploration where the optimal experiment is chosen as the one which maximizes the expected information gain. The inference engine is implemented using the nested sampling algorithm, which provides the inquiry engine with a set of posterior samples from which the expected information gain can be estimated. With these computational structures in place, the instrument will refine its hypotheses, and repeat the learning cycle by taking measurements until the system under study is described within a pre-specified tolerance. We will demonstrate our first attempts toward achieving this goal with an intelligent instrument constructed using the LEGO MINDSTORMS NXT robotics platform.

  12. The tropospheric monitoring instrument

    NARCIS (Netherlands)

    Voert, M.J. te; Brakel, R. van; Witvoet, G.

    2014-01-01

    Thermal and opto-mechanical design and analysis work has been done on the Tropospheric Monitoring Instrument (TROPOMI), a spectrometer on the Copernicus Sentinel 5 Precursor satellite. To verify compliance with the stringent opto-mechanical stability requirements, detailed thermal and

  13. University Reactor Instrumentation Program

    International Nuclear Information System (INIS)

    Vernetson, W.G.

    1992-11-01

    Recognizing that the University Reactor Instrumentation Program was developed in response to widespread needs in the academic community for modernization and improvement of research and training reactors at institutions such as the University of Florida, the items proposed to be supported by this grant over its two year period have been selected as those most likely to reduce foreed outages, to meet regulatory concerns that had been expressed in recent years by Nuclear Regulatory Commission inspectors or to correct other facility problems and limitations. Department of Energy Grant Number DE-FG07-90ER129969 was provided to the University of Florida Training Reactor(UFTR) facility through the US Department of Energy's University Reactor Instrumentation Program. The original proposal submitted in February, 1990 requested support for UFTR facility instrumentation and equipment upgrades for seven items in the amount of $107,530 with $13,800 of this amount to be the subject of cost sharing by the University of Florida and $93,730 requested as support from the Department of Energy. A breakdown of the items requested and total cost for the proposed UFTR facility instrumentation and equipment improvements is presented

  14. Analytical chemistry instrumentation

    International Nuclear Information System (INIS)

    Laing, W.R.

    1986-01-01

    Separate abstracts were prepared for 48 papers in these conference proceedings. The topics covered include: analytical chemistry and the environment; environmental radiochemistry; automated instrumentation; advances in analytical mass spectrometry; Fourier transform spectroscopy; analytical chemistry of plutonium; nuclear analytical chemistry; chemometrics; and nuclear fuel technology

  15. Advanced instrumentation and teleoperation

    International Nuclear Information System (INIS)

    Decreton, M.

    1998-01-01

    SCK-CEN's advanced instrumentation and teleoperation project aims at evaluating the potential of a telerobotic approach in a nuclear environment and, in particular, the use of remote-perception systems. Main achievements in 1997 in the areas of R and D on radiation tolerance for remote sensing, optical fibres and optical-fibre sensors, and computer-aided teleoperation are reported

  16. Analytical chemistry instrumentation

    International Nuclear Information System (INIS)

    Laing, W.R.

    1986-01-01

    In nine sections, 48 chapters cover 1) analytical chemistry and the environment 2) environmental radiochemistry 3) automated instrumentation 4) advances in analytical mass spectrometry 5) fourier transform spectroscopy 6) analytical chemistry of plutonium 7) nuclear analytical chemistry 8) chemometrics and 9) nuclear fuel technology

  17. Solid Polarized Targets and Applications

    International Nuclear Information System (INIS)

    Crabb, D. G.

    2008-01-01

    Examples are given of dynamically polarized targets in use today and how the subsystems have changed to meet the needs of todays experiments. Particular emphasis is placed on target materials such as ammonia and lithium deuteride. Recent polarization studies of irradiated materials such as butanol, deuterated butanol, polyethylene, and deuterated polyethylene are presented. The operation of two non-DNP target systems as well as applications of traditional DNP targets are briefly discussed

  18. Artificial anisotropy and polarizing filters.

    Science.gov (United States)

    Flory, François; Escoubas, Ludovic; Lazaridès, Basile

    2002-06-01

    The calculated spectral transmittance of a multilayer laser mirror is used to determine the effective index of the single layer equivalent to the multilayer stack. We measure the artificial anisotropy of photoresist thin films whose structure is a one-dimensional, subwavelength grating obtained from interference fringes. The limitation of the theory of the first-order effective index homogenization is discussed. We designed normal-incidence, polarizing coating and a polarization rotator by embedding anisotropic films in simple multilayer structures.

  19. Polarization bremsstrahlung in α decay

    International Nuclear Information System (INIS)

    Amusia, M. Ya.; Zon, B. A.; Kretinin, I. Yu.

    2007-01-01

    A mechanism of formation of electromagnetic radiation that accompanies α decay and is associated with the emission of photons by electrons of atomic shells due to the scattering of α particles by these atoms (polarization bremsstrahlung) is proposed. It is shown that, when the photon energy is no higher than the energy of K electrons of an atom, polarization bremsstrahlung makes a significant contribution to the bremsstrahlung in α decay

  20. Coherent states with elliptical polarization

    OpenAIRE

    Colavita, E.; Hacyan, S.

    2004-01-01

    Coherent states of the two dimensional harmonic oscillator are constructed as superpositions of energy and angular momentum eigenstates. It is shown that these states are Gaussian wave-packets moving along a classical trajectory, with a well defined elliptical polarization. They are coherent correlated states with respect to the usual cartesian position and momentum operators. A set of creation and annihilation operators is defined in polar coordinates, and it is shown that these same states ...

  1. Extreme-Scale Alignments Of Quasar Optical Polarizations And Galactic Dust Contamination

    Science.gov (United States)

    Pelgrims, Vincent

    2017-10-01

    Almost twenty years ago the optical polarization vectors from quasars were shown to be aligned over extreme-scales. That evidence was later confirmed and enhanced thanks to additional optical data obtained with the ESO instrument FORS2 mounted on the VLT, in Chile. These observations suggest either Galactic foreground contamination of the data or, more interestingly, a cosmological origin. Using 353-GHz polarization data from the Planck satellite, I recently showed that the main features of the extreme-scale alignments of the quasar optical polarization vectors are unaffected by the Galactic thermal dust. This confirms previous studies based on optical starlight polarization and discards the scenario of Galactic contamination. In this talk, I shall briefly review the extreme-scale quasar polarization alignments, discuss the main results submitted in A&A and motivate forthcoming projects at the frontier between Galactic and extragalactic astrop hysics.

  2. Acceleration of polarized H- in the BNL 200 MeV Linac

    International Nuclear Information System (INIS)

    Makdisi, Y.; Witkover, R.; Alessi, J.; Brown, H.; Barton, D.; Kponou, A.; McNerney, A.

    1985-01-01

    The AGS Polarized Beam Project was started in 1980. The first beam was accelerated in March 1984, followed by commissioning studies and a high energy physics run at 16.5 GeV at an average 30% polarization. The Linac portion of the project included a new polarized H - ion source and a Radio-Frequency Quadrupole (RFQ). These will be described as will the design of the new Low Energy Beam Transport (LEBT) line and beam instrumentation for the Linac. Operational results, current status and future plans will be discussed. 13 refs., 6 figs

  3. Polarization of Coronal Forbidden Lines

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao; Qu, Zhongquan [Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China); Landi Degl’Innocenti, Egidio, E-mail: sayahoro@ynao.ac.cn [Dipartimento di Astronomia e Scienza dello Spazio, Università di Firenze, Largo E. Fermi 2, I-50125 Firenze (Italy)

    2017-03-20

    Since the magnetic field is responsible for most manifestations of solar activity, one of the most challenging problems in solar physics is the diagnostics of solar magnetic fields, particularly in the outer atmosphere. To this end, it is important to develop rigorous diagnostic tools to interpret polarimetric observations in suitable spectral lines. This paper is devoted to analyzing the diagnostic content of linear polarization imaging observations in coronal forbidden lines. Although this technique is restricted to off-limb observations, it represents a significant tool to diagnose the magnetic field structure in the solar corona, where the magnetic field is intrinsically weak and still poorly known. We adopt the quantum theory of polarized line formation developed in the framework of the density matrix formalism, and synthesize images of the emergent linear polarization signal in coronal forbidden lines using potential-field source-surface magnetic field models. The influence of electronic collisions, active regions, and Thomson scattering on the linear polarization of coronal forbidden lines is also examined. It is found that active regions and Thomson scattering are capable of conspicuously influencing the orientation of the linear polarization. These effects have to be carefully taken into account to increase the accuracy of the field diagnostics. We also found that linear polarization observation in suitable lines can give valuable information on the long-term evolution of the magnetic field in the solar corona.

  4. Polarization in free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Papadichev, V.A. [Lebedev Physical Institute, Moscow (Russian Federation)

    1995-12-31

    Polarization of electromagnetic radiation is required very often in numerous scientific and industrial applications: studying of crystals, molecules and intermolecular interaction high-temperature superconductivity, semiconductors and their transitions, polymers and liquid crystals. Using polarized radiation allows to obtain important data (otherwise inaccessible) in astrophysics, meteorology and oceanology. It is promising in chemistry and biology for selective influence on definite parts of molecules in chain synthesis reactions, precise control of various processes at cell and subcell levels, genetic engineering etc. Though polarization methods are well elaborated in optics, they can fail in far-infrared, vacuum-ultraviolet and X-ray regions because of lack of suitable non-absorbing materials and damaging of optical elements at high specific power levels. Therefore, it is of some interest to analyse polarization of untreated FEL radiation obtained with various types of undulators, with and without axial magnetic field. The polarization is studied using solutions for electron orbits in various cases: plane or helical undulator with or without axial magnetic field, two plane undulators, a combination of right- and left-handed helical undulators with equal periods, but different field amplitudes. Some examples of how a desired polarization (elliptical circular or linear) can be obtained or changed quickly, which is necessary in many experiments, are given.

  5. Thirty Years Supporting Portable Arrays: The IRIS Passcal Instrument Center

    Science.gov (United States)

    Beaudoin, B. C.; Anderson, K. R.; Bilek, S. L.; Woodward, R.

    2014-12-01

    Thirty years have passed since establishment of the IRIS Program for the Array Seismic Studies of the Continental Lithosphere (PASSCAL). PASSCAL was part of a coordinated plan proposed to the National Science Foundation (NSF) defining the instrumentation, data collection and management structure to support a wide range of research in seismology. The PASSCAL program has surpassed the early goal of 6000 data acquisition channels with a current inventory of instrumentation capable of imaging from the near surface to the inner core. Here we present the evolution of the PASSCAL program from instrument depot to full service community resource. PASSCAL has supported close to 1100 PI driven seismic experiments since its inception. Instruments from PASSCAL have covered the globe and have contributed over 7400 SEED stations and 242 assembled data sets to the IRIS Data Management Center in Seattle. Since the combination in 1998 of the Stanford and Lamont instrument centers into the single PASSCAL Instrument Center (PIC) at New Mexico Tech, the facility has grown in scope by adding the EarthScope Array Operations Facility in 2005, the incorporation of the EarthScope Flexible Array, and a Polar support group in 2006. The polar support group enhances portable seismic experiments in extremely harsh polar environments and also extends to special projects such as the Greenland Ice Sheet Monitoring Network (GLISN) and the recent development effort for Geophysical Earth Observatory for Ice Covered Environments (GEOICE). Through these support efforts the PIC has established itself as a resource for field practices, engineered solutions for autonomous seismic stations, and a pioneer in successful seismic recording in polar environments. We are on the cusp of a new generation of instrumentation driven in part by the academic community's desire to record unaliased wavefields in multiple frequency bands and industry's interest in utilizing lower frequency data. As part of the recently

  6. Antenna Characterization for the Wideband Instrument for Snow Measurements

    Science.gov (United States)

    Lambert, Kevin M.; Miranda, Felix A.; Romanofsky, Robert R.; Durham, Timothy E.; Vanhille, Kenneth J.

    2015-01-01

    Experimental characterization of the antenna for the Wideband Instrument for Snow Measurements (WISM) under development for the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP), is discussed. A current sheet antenna, consisting of a small, 6x6 element, dual-linear polarized array with integrated beamformer, feeds an offset parabolic reflector, enabling WISM operation over an 8 to 40 GHz frequency band. An overview of the test program implemented for both the feed and the reflector antenna is given along with select results for specific frequencies utilized by the radar and radiometric sensors of the WISM.

  7. Antenna Characterization for the Wideband Instrument for Snow Measurements (WISM)

    Science.gov (United States)

    Lambert, Kevin M.; Miranda, Felix A.; Romanofsky, Robert R.; Durham, Timothy E.; Vanhille, Kenneth J.

    2015-01-01

    Experimental characterization of the antenna for the Wideband Instrument for Snow Measurement (WISM) under development for the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP), is discussed. A current sheet antenna, consisting of a small, 6x6 element, dual-linear polarized array with integrated beamformer, feeds an offset parabolic reflector, enabling WISM operation over an 8 to 40 GHz frequency band. An overview of the test program implemented for both the feed and the reflector antenna is given along with select results for specific frequencies utilized by the radar and radiometric sensors of the WISM.

  8. The Science of String Instruments

    CERN Document Server

    Rossing, Thomas D

    2010-01-01

    Many performing musicians, as well as instrument builders, are coming to realize the importance of understanding the science of musical instruments. This book explains how string instruments produce sound. It presents basic ideas in simple language, and it also translates some more sophisticated ideas in non-technical language. It should be of interest to performers, researchers, and instrument makers alike.

  9. Advanced Antenna Design for NASA's EcoSAR Instrument

    Science.gov (United States)

    Du Toit, Cornelis F.; Deshpande, Manohar; Rincon, Rafael F.

    2016-01-01

    Advanced antenna arrays were designed for NASA's EcoSAR airborne radar instrument. EcoSAR is a beamforming synthetic aperture radar instrument designed to make polarimetric and "single pass" interferometric measurements of Earth surface parameters. EcoSAR's operational requirements of a 435MHz center frequency with up to 200MHz bandwidth, dual polarization, high cross-polarization isolation (> 30 dB), +/- 45deg beam scan range and antenna form-factor constraints imposed stringent requirements on the antenna design. The EcoSAR project successfully developed, characterized, and tested two array antennas in an anechoic chamber. EcoSAR's first airborne campaign conducted in the spring of 2014 generated rich data sets of scientific and engineering value, demonstrating the successful operation of the antennas.

  10. Development of a Next Generation Polar Multidisciplinary Airborne Imaging System for the International Polar Year 2007-2009

    Science.gov (United States)

    Bell, R. E.; Studinger, M.; Frearson, N.; Gogineni, P.; Braaten, D.

    2007-12-01

    Key elements in Earth's geodynamic and climatic systems, the polar regions are very sensitive to changing global environmental conditions such as increasing sea surface temperatures and have the potential to trigger significant global sea level rise as large volumes of ice melt. Locked within these icy regions are the records of past global climate shifts and novel ecosystems sealed from open interactions with the atmosphere for millions of years. While satellite missions can image the surface of the polar ice sheet, many of the key processes occur beneath the surface beyond the reach of space based observations. These crucial processes can only be efficiently examined through airborne instrumentation designed to study the vast expanses of snow and ice of the Antarctic continent, the sub-continent of Greenland and the surrounding oceans. The expanding logistical infrastructure associated with the International Polar Year (2007-2009) will enable the scientific community access major new portions of the polar regions. We are developing a state-of-the-art integrated multidisciplinary aerogeophysical instrumentation package for deployment during multi-national expeditions as part of the International Polar Year. This development project brings together the recent developments in radar sounding by the University of Kansas CReSIS (Center for Remote Sensing of Ice Sheets), that now permit the full characterization of the entire ice sheet and the major advances in the accuracy, resolution and efficiency of airborne gravity technology emerging from the private sector. Integrating the full spectrum of ice sheet imaging with high-resolution gravity and magnetics will enable the imaging of the previously invisible world of subglacial hydrodynamics.

  11. POLAR - novel hard X-ray polarimeter for Gamma Ray Bursts

    Science.gov (United States)

    Hajdas, Wojtek

    Our present knowledge of the Gamma Ray Bursts GRBs - the most powerful explosions in the universe after the Big Bang - links them with a birth of the black holes and localize at cosmological distances. There is also a strong evidence relating some of them with Supernovae and thus with gravitational waves. Despite of such significant role of GRBs only little is known about their mechanisms and progenitors. Existing theories still have troubles describing bursts prompt emissions while predictions of the photon polarization show large divergences. On the observational side there are just few isolated measurements of the hard X-ray polarization affected by large experimental uncertainties. Nevertheless, it became clear that determining the GRB polarization could be an ultimate step for understanding their genuine nature. To participate in this task we propose POLAR - novel instrument for hard X-ray and low energy gamma ray polarimetry. The instrument goal is to perform highly precise polarization studies from a very large number of GRBs. Measurements of the linear polarization in the GRB prompt emission at photon energies from 5 keV to 500 keV will be carried out using continuous observations of the sky. Our calculations showed that for several bursts per year the experimental precision will reach a 1 sigma level of 3 per cent. For the strongest events it will be possible to study polarization as a function of energy achieving much more detailed view of the emitting system structure. POLAR uses a uniform array of 1600 weakly shielded plastic detectors coupled with the new multi-anode photo-multipliers. The polarization measurement is based on Compton scattering and relies on detection of fast coincidences between plastic scintillator bars. The total mass (28 kg) and power requirements (30 W) are very moderate. POLAR has relatively small dimensions and it was designed to be not only non-intrusive but also highly adaptable. The qualification model is currently under

  12. Superconducting polarizing magnet for a movable polarized target

    International Nuclear Information System (INIS)

    Anishchenko, N.G.; Bartenev, V.D.; Blinov, N.A.

    1998-01-01

    The superconducting polarizing magnet was constructed for the JINR (Dubna) movable polarized target (MPT) with working volume 200 mm long and 30 mm in diameter. The magnet provides a polarizing magnetic field up to 6 T in the centre with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet contains a main solenoidal winding 558 mm long and 206/144 mm in diameters, and compensating and correcting winding placed at its ends. The windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat. The diameter of the 'warm' aperture of the magnet cryostat is 96 mm. The design and technology of the magnet winding are described. Results of the magnetic field map measurements, using a NMR-magnetometer are given. A similar magnet constructed at DAPNIA, CEA/Saclay (France), represented a model for the present development. The MPT array is installed in the beam line of polarized neutrons produced by break-up of polarized deuterons extracted from the synchrophasotron of the Laboratory of High Energies (LHE), JINR (Dubna)

  13. netherland hydrological modeling instrument

    Science.gov (United States)

    Hoogewoud, J. C.; de Lange, W. J.; Veldhuizen, A.; Prinsen, G.

    2012-04-01

    Netherlands Hydrological Modeling Instrument A decision support system for water basin management. J.C. Hoogewoud , W.J. de Lange ,A. Veldhuizen , G. Prinsen , The Netherlands Hydrological modeling Instrument (NHI) is the center point of a framework of models, to coherently model the hydrological system and the multitude of functions it supports. Dutch hydrological institutes Deltares, Alterra, Netherlands Environmental Assessment Agency, RWS Waterdienst, STOWA and Vewin are cooperating in enhancing the NHI for adequate decision support. The instrument is used by three different ministries involved in national water policy matters, for instance the WFD, drought management, manure policy and climate change issues. The basis of the modeling instrument is a state-of-the-art on-line coupling of the groundwater system (MODFLOW), the unsaturated zone (metaSWAP) and the surface water system (MOZART-DM). It brings together hydro(geo)logical processes from the column to the basin scale, ranging from 250x250m plots to the river Rhine and includes salt water flow. The NHI is validated with an eight year run (1998-2006) with dry and wet periods. For this run different parts of the hydrology have been compared with measurements. For instance, water demands in dry periods (e.g. for irrigation), discharges at outlets, groundwater levels and evaporation. A validation alone is not enough to get support from stakeholders. Involvement from stakeholders in the modeling process is needed. There fore to gain sufficient support and trust in the instrument on different (policy) levels a couple of actions have been taken: 1. a transparent evaluation of modeling-results has been set up 2. an extensive program is running to cooperate with regional waterboards and suppliers of drinking water in improving the NHI 3. sharing (hydrological) data via newly setup Modeling Database for local and national models 4. Enhancing the NHI with "local" information. The NHI is and has been used for many

  14. Joint Polar Satellite System: the United States New Generation Civilian Polar Orbiting Environmental Satellite System

    Science.gov (United States)

    Mandt, G.

    2017-12-01

    The Joint Polar Satellite System (JPSS) is the Nation's advanced series of polar-orbiting environmental satellites. JPSS represents significant technological and scientific advancements in observations used for severe weather prediction and environmental monitoring. The Suomi National Polar-orbiting Partnership (S-NPP) is providing state-of-the art atmospheric, oceanographic, and environmental data, as the first of the JPSS satellites while the second in the series, J-1, is scheduled to launch in October 2017. The JPSS baseline consists of a suite of four instruments: an advanced microwave and infrared sounders which are critical for weather forecasting; a leading-edge visible and infrared imager critical to data sparse areas such as Alaska and needed for environmental assessments such as snow/ice cover, droughts, volcanic ash, forest fires and surface temperature; and an ozone sensor primarily used for global monitoring of ozone and input to weather and climate models. The same suite of instruments that are on JPSS-1 will be on JPSS-2, 3 and 4. The JPSS-2 instruments are well into their assembly and test phases and are scheduled to be completed in 2018. The JPSS-2 spacecraft critical design review (CDR) is scheduled for 2Q 2018 with the launch in 2021. The sensors for the JPSS-3 and 4 spacecraft have been approved to enter into their acquisition phases. JPSS partnership with the US National Aeronautics and Space Agency (NASA) continues to provide a strong foundation for the program's success. JPSS also continues to maintain its important international relationships with European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and the Japan Aerospace Exploration Agency (JAXA). JPSS works closely with its user community through the Proving Ground and Risk Reduction (PGRR) Program to identify opportunities to maximize the operational application of current JPSS capabilities. The PGRR Program also helps identify and evaluate the use of JPSS

  15. Polarization fluctuations in stationary light beams

    International Nuclear Information System (INIS)

    Shevchenko, A.; Setaelae, T.; Kaivola, M.; Friberg, A.T.; Royal Institute of Technology , Department of Microelectronics and Applied Physics; Sweden)

    2009-01-01

    For stationary beams the degree of polarization contains only limited information on time dependent polarization. Two approaches towards assessing a beams polarization dynamics, one based on Poincare and the other on Jones vector formalism, are described leading to the notion of polarization time. Specific examples of partially temporally coherent electromagnetic beams are discussed. (Author)

  16. FIRST POLARIZED PROTON COLLISIONS AT RHIC

    International Nuclear Information System (INIS)

    ROSER, T.; AHRENS, L.; ALESSI, J.; BAI, M.; BEEBE-WANG, J.; BRENNAN, J.M.; BROWN, K.A.; BUNCE, G.; CAMERON, P.; COURANT, E.D.; DREES, A.; FISCHER, W.; FLILLER, R. III; GLENN, W.; HUANG, H.; LUCCIO, A.U.; MACKAY, W.W.; MAKDISI, Y.; MONTAG, C.; PILAT, F.; PTITSYN, V.; SATOGATA, T.

    2002-01-01

    We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180 o about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV

  17. Apico-basal polarity complex and cancer

    Indian Academy of Sciences (India)

    Apico-basal polarity is a cardinal molecular feature of adult eukaryotic epithelial cells and appears to be involved in several key cellular processes including polarized cell migration and maintenance of tissue architecture. Epithelial cell polarity is maintained by three well-conserved polarity complexes, namely, PAR, Crumbs ...

  18. Remote sensing of aerosols by using polarized, directional and spectral measurements within the A-Train: the PARASOL mission

    Directory of Open Access Journals (Sweden)

    D. Tanré

    2011-07-01

    Full Text Available Instruments dedicated to aerosol monitoring are recently available and the POLDER (POLarization and Directionality of the Earth's Reflectances instrument on board the PARASOL (Polarization & Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar mission is one of them. By measuring the spectral, angular and polarization properties of the radiance at the top of the atmosphere, in coordination with the other A-Train instruments, PARASOL provides the aerosol optical depths (AOD as well as several optical and microphysical aerosol properties. The instrument, the inversion schemes and the list of aerosol parameters are described. Examples of retrieved aerosol parameters are provided as well as innovative approaches and further inversion techniques.

  19. Polarized 3He gas circulating technologies for neutron analyzers

    Energy Technology Data Exchange (ETDEWEB)

    Watt, David W. [Xemed, LLC, Durham, NH (United States)

    2017-10-02

    apply sol-gel coatings to the interior of both borosilicate and aluminosilicate cells. We applied six sol-gel coatings. By modifying the mixture and developing procedures to drain and dry the cell, we produced visually uniform coatings on the interior of the cells. We now have perfected that process as described below in our report. We were able to accelerate the testing of cells using an ex situ method that avoids installing each cell into a polarizer. In the project’s last year, we conducted 38 external tests of 8 different cells. We also installed two sol-gel coated cells in our polarizers. We created cell with long ex situ relaxation lifetimes, one of which exceeded 40 hours. However, when installed in the polarizer the measured lifetime is 8 hours or less. 3. Demonstrated cycling of polarized gas and ex situ cell testing We are now cycling polarized gas from the polarizer to glass vessels and back. This has allowed us, for the first time, to make ex situ T1 measurements of polarizing cells without installing them into the polarizer itself. This has greatly improved our productivity in producing cells and evaluating our cell preparation processes. We continued development of the gas handling system in parallel with fabricating new polarizer. The integrated system was tested by the end of 2016. We now regularly cycle gas into and out of the polarizer. 4. Completed new polarizer infrastructure and control systems. We completed the new polarizer infrastructure in November 2016. The polarizer subsystems are 1) the frame, 2) the oil flow system, 3) the gas handling system, 4) the pressure vessel, with embedded solenoid, 5) cell mounting hardware with heat spreaders, and 6) electrical power and instrumentation. 5. Carried out initial tests of polarizer. We completed initial testing of the polarizer in April and May of 2017. These tests were carried out for periods up to 6 hours with laser power between 750 and 1300 Watts. The laser performed well and the polarization

  20. The UVISI instrument.

    Science.gov (United States)

    Heffernan, K. J.; Heiss, J. E.; Boldt, J. D.; Darlington, E. H.; Peacock, K.; Harris, T. J.; Mayr, M. J.

    1996-06-01

    The Ultraviolet and Visible Imagers and Spectrographic Imagers (UVISI) instrument is a complex of nine sensor units (five spectrographic imagers and four imagers) and multiple processors that will provide detailed images and spectra of targets for the Midcourse Space Experiment mission. Imaging and spectroscopy each cover the range from 110 nm (far ultraviolet) to 900 nm (near infrared). UVISI is intended to investigate a multitude of celestial, atmospheric, and point sources over its planned 4-year lifetime. At 104 W and 211 kg, it is not only the largest free-flying instrument ever built at APL, but is also larger than 47 of the 55 APL-built spacecraft and more complex than many of them. This article discusses the specifications of UVISI and its hardware and software features. It also attempts to give the reader a sense of the design trade-offs made during UVISI development that resulted in its present configuration.

  1. Data acquisition instruments: Psychopharmacology

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, D.S. III

    1998-01-01

    This report contains the results of a Direct Assistance Project performed by Lockheed Martin Energy Systems, Inc., for Dr. K. O. Jobson. The purpose of the project was to perform preliminary analysis of the data acquisition instruments used in the field of psychiatry, with the goal of identifying commonalities of data and strategies for handling and using the data in the most advantageous fashion. Data acquisition instruments from 12 sources were provided by Dr. Jobson. Several commonalities were identified and a potentially useful data strategy is reported here. Analysis of the information collected for utility in performing diagnoses is recommended. In addition, further work is recommended to refine the commonalities into a directly useful computer systems structure.

  2. Superfluid helium tanker instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Woodhouse, C.E. (Johns Hopkins Univ., Baltimore, MD (USA). School of Medicine); Kashani, A. (Sterling Federal Systems, Inc., NASA/Ames Research Center, Moffett Field, CA (US)); Lukemire, A.T. (National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center)

    1990-02-01

    An instrumentation system for a 1992 space shuttle flight demonstration of a superfluid helium (SFHe) tanker and transfer technology is presented. This system provides measurement of helium temperatures, pressures, flow rates, mass, and the presence of liquid or vapor. The instrumentation system described consists of analog and digital portions which provide a space qualified electronics system that is fault tolerant, compact, and relatively lightweight. The data processing hardware and software are ground commandable, perform measurements asynchronously, and format telemetry for transmission to the ground. The novel heat pulse mass gaging technique is described. A new liquid/vapor sensor is presented. Flowmeters for SFHe are discussed. A SFHe fountain effect pump is described. Results of tests to date are presented.

  3. Virtual Reality Musical Instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low-cost technologies have created a wide interest in virtual reality. In the field of computer music, the term “virtual musical instruments” has been used for a long time to describe software simulations, extensions of existing musical instruments......, and ways to control them with new interfaces for musical expression. Virtual reality musical instruments (VRMIs) that include a simulated visual component delivered via a head-mounted display or other forms of immersive visualization have not yet received much attention. In this article, we present a field...... overview of VRMIs from the viewpoint of the performer. We propose nine design guidelines, describe evaluation methods, analyze case studies, and consider future challenges....

  4. Radiation measuring instrument

    International Nuclear Information System (INIS)

    Genrich, V.

    1985-01-01

    A highly sensitive and compactly structured radiation measuring instrument for detecting ionizing radiation, in particular for measuring dose rates and contamination. The laminar structure of the associated counter tube, using only a few, simple plastic parts and a highly elastic counter wire, makes it possible to use the simplest manufacturing techniques. The service life of the counter tube construction, which is completely and permanently sealed and filled with gas, is expected to be more than 12 years. The described counter tube can be adapted in optimal fashion to the available space in a pocket instrument if it is used in combination with a specialized high-voltage generator which is low in interference voltage and with a pulse evaluation circuit having a means of compensating for interference voltage

  5. Airborne Open Polar/Imaging Nephelometer for Ice Particles in Cirrus Clouds and Aerosols Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Martins, JV [Univ. of Maryland, College Park, MD (United States)

    2016-04-01

    The Open Imaging Nephelometer (O-I-Neph) instrument is an adaptation of a proven laboratory instrument built and tested at the University of Maryland, Baltimore County (UMBC), the Polarized Imaging Nephelometer (PI-Neph). The instrument design of both imaging nephelometers uses a narrow-beam laser source and a wide-field-of-view imaging camera to capture the entire scattering-phase function in one image, quasi-instantaneously.

  6. Instrumentation Engineers Handbook

    Science.gov (United States)

    2013-01-01

    White Sands Missile Range New Mexico 88002-5110 This page intentionally left blank. Instrumentation Engineers Handbook, RCC Document 121-13...Range Commanders Council ATTN: TEDT-WS-RCC 1510 Headquarters Avenue White Sands Missile Range, New Mexico 88002-5110 Telephone: (575) 678-1107...multiplying that by the C/D ratio, where C is a dimensional constant and D is density: ( ) D PPC V Tpp − = Eqn. 5-8 When the flow rate is obtained by

  7. Radon-Instrumentation

    International Nuclear Information System (INIS)

    Moreno y Moreno, A.

    2003-01-01

    The presentation of the active and passive methods for radon, their identification and measure, instrumentation and characteristics are the objectives of this work. Active detectors: Active Alpha Cam Continuous Air Monitor, Model 758 of Victoreen, Model CMR-510 Continuous Radon Monitor of the Signature Femto-Tech. Passive detectors: SSNTD track detectors in solids Measurement Using Charcoal Canisters, disk of activated coal deposited in a metallic box Electrets Methodology. (Author)

  8. Virtual reality musical instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low cost technologies has created a wide interest in virtual reality (VR), but how to design and evaluate multisensory interactions in VR remains as a challenge. In this paper, we focus on virtual reality musical instruments, present an overview of our...... design and evaluation guidelines, and examine historical case studies. Our main contribution is to inform the design and evaluation of the future VRMIs and consider the challenges....

  9. On-ground characterization of the IXPE polarization angle knowledge

    Science.gov (United States)

    Evangelista, Y.

    2017-08-01

    The Imaging X-ray Polarimetry Explorer (IXPE) has been recently selected for development as part of NASA's Small Explorer program (SMEX), with a launch date in 2021. Developed in a collaboration between NASA and the Italian Space Agency (ASI), IXPE will perform groundbreaking measurements of imaging polarization in X-rays for a number of different classes of sources including isolated and accreting neutron stars, pulsar wind nebulae, stellar and supermassive black holes. Combining 30 arcsec (HPD) grazing-incidence X-ray optics with the polarization-sensitive Gas Pixel Detectors (GPDs), IXPE will provide two-orders of magnitude improvement in sensitivity over the past flown instruments. The IXPE requested precision on the measurement of the polarization angle (better than 0.2 degrees at instrument level) poses strict constraints on the detector unit (DU) mechanical design and requires the implementation of a specific alignment and measurement strategy to meet the scientific requirements. In this paper we describe the design solutions that will be implemented in the DU flight models as well as a step-by-step metrology procedure that will ensure the fulfillment of the scientific requirement.

  10. Inclusive quasielastic scattering of polarized electrons from polarized nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Amaro, J.E. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Center for Theoretical Physics]|[Universidad de Granada (Spain). Dept. de Fisica Moderna]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Lab. for Nuclear Science]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics; Caballero, J.A. [Consejo Superior de Investigaciones Cientificas (CSIC), Madrid (Spain). Inst. de Estructura de la Materia]|[Sevilla Univ. (Spain). Dept. de Fisica Atomica, Molecular y Nuclear; Donnelly, T.W. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Center for Theoretical Physics]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Lab. for Nuclear Science]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics; Moya de Guerra, E. [Consejo Superior de Investigaciones Cientificas (CSIC), Madrid (Spain). Inst. de Estructura de la Materia

    1996-12-23

    The inclusive quasielastic response functions that appear in the scattering of polarized electrons from polarized nuclei are computed and analyzed for several closed-shell-minus-one nuclei with special attention paid to {sup 39}K. Results are presented using two models for the ejected nucleon - when described by a distorted wave in the continuum shell model or by a plane wave in PWIA with on- and off-shell nucleons. Relativistic effects in kinematics and in the electromagnetic current have been incorporated throughout. Specifically, the recently obtained expansion of the electromagnetic current in powers only of the struck nucleon`s momentum is employed for the on-shell current and the effects of the first-order terms (spin-orbit and convection) are compared with the zeroth-order (charge and magnetization) contributions. The use of polarized inclusive quasielastic electron scattering as a tool for determining near-valence nucleon momentum distributions is discussed. (orig.).

  11. System for measuring of proton polarization in polarized target

    International Nuclear Information System (INIS)

    Derkach, A.Ya.; Lukhanin, A.A.; Karnaukhov, I.M.; Kuz'menko, V.S.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

    1981-01-01

    Measurement system of proton polarization in the target, which uses the method of nuclear magnetic resonance is described. To record the signal of NMR-absorption a parallel Q-meter of voltage with analogous subtraction of resonance characteristics of measurement circuit is used. To obtain gradual sensitivity of the system to polarization state in the whole volume of the target the measurement coils is made of tape conductor. The analysis and mathematical modelling of Q-meter are carried out. Corrections for nonlinearity and dispersion are calculated. Key diagrams of the main electron blocks of Q-meter are presented. The system described operates on line with the M6000 computer. Total error of measurement of polarization value of free protons in the target does not exceed 6% [ru

  12. System of measurement of proton polarization in a polarized target

    Energy Technology Data Exchange (ETDEWEB)

    Karnaukov, I.M.; Chechetenko, V.F.; Lukhanin, A.A.; Telegin, Y.N.; Trotsenko, V.I.

    1985-05-01

    This paper describes a nuclear magnetic resonance spectrometer with high sensitivity. The signal of NMR absorption is recorded by a Q-meter with a series circuit and a circuit for compensation of the resonance characteristic of the measuring circuit. In order to ensure uniform sensitivity of the system to the state of polarization throughout the volume of the target and to enhance the S/N ration the measuring coil is made of a flat conductor. The polarization-measuring system works on-line with an M-6000 computer. The total error of measurement of the polarization of free protons in a target with allowance for the error due to local depolarization of free protons in a target with allowance for the error due to local depolarization of the working substance under irradiation with an intense photon beam is less than or equal to 6%.

  13. Nuclear reactor instrumentation

    International Nuclear Information System (INIS)

    Duncombe, E.; McGonigal, G.

    1976-01-01

    Reference is made to the instrumentation of liquid metal cooled fast reactors. In order to ensure the safe operation of such reactors it is necessary to constantly monitor the coolant flowing through the fuel assemblies for temperature and rate of flow, requiring a large number of sensors. An improved and simplified arrangement is claimed in which the fuel assemblies feed a fraction of coolant to three instrument units arranged to sense the temperature and rate of flow of samples of coolant. Each instrument unit comprises a sleeve housing a sensing unit and has a number of inlet ducts arranged for receiving coolant from a fuel assembly together with a single outlet. The sensing unit has three thermocouple hot junctions connected in series, the hot junctions and inlet ducts being arranged in pairs. Electromagnetic windings around an inductive core are arranged to sense variation in flow of liquid metal by flux distortion. Fission product sensing means may also be provided. Full constructional details are given. (U.K.)

  14. Instrumentation and diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Nakaishi, C.V.; Bedick, R.C.

    1990-12-01

    This Technology Status Report describes research and accomplishments for the Instrumentation and Diagnostics (I D) Projects within the Advanced Research and Technology Development (AR TD) Program of the United States Department of Energy (DOE) Office of Fossil Energy (FE). Process understanding and control can be improved through the development of advanced instrumentation and diagnostics. The thrust of the I D Projects is to further develop existing measurement and control techniques for application to advanced coal-based technologies. Project highlights are: an inductively coupled plasma (ICP) instrument has been developed to analyze trace elements in gasification and combustion process streams. An in situ two-color Mie scattering technique with LSS can simultaneously measure the size, velocity, and elemental composition of coal particles during combustion. A high-temperature, fluorescence thermometry technique has accurately measured gas temperatures during field testing in combustion and gasification environments. Expert systems have been developed to improve the control of advanced coal-based processes. Capacitance flowmeters were developed to determine the mass flowrate, solid volume fraction, and particle velocities of coal slurries. 32 refs., 9 figs.

  15. Mandolin Family Instruments

    Science.gov (United States)

    Cohen, David J.; Rossing, Thomas D.

    The mandolin family of instruments consists of plucked chordophones, each having eight strings in four double courses. With the exception of the mandobass, the courses are tuned in intervals of fifths, as are the strings in violin family instruments. The soprano member of the family is the mandolin, tuned G3-D4-A4-E5. The alto member of the family is the mandola, tuned C3-G3-D4-A4. The mandola is usually referred to simply as the mandola in the USA, but is called the tenor mandola in Europe. The tenor member of the family is the octave mandolin, tuned G2-D3-A3-E4. It is referred to as the octave mandolin in the USA, and as the octave mandola in Europe. The baritone member of the family is the mandocello, or mandoloncello, tuned C2-G2-D3-A3. A variant of the mandocello not common in the USA is the five-course liuto moderno, or simply liuto, designed for solo repertoire. Its courses are tuned C2-G2-D3-A3-E4. A mandobass was also made by more than one manufacturer during the early twentieth century, though none are manufactured today. They were fretted instruments with single string courses tuned E1-A1-D2-G2. There are currently a few luthiers making piccolo mandolins, tuned C4-G4-D5-A5.

  16. Water Ice Albedo Variations on the Martian Northern Polar Cap

    Science.gov (United States)

    Hale, A. S.; Bass, D. S.; Tamppari, L. K.

    2003-01-01

    The Viking Orbiters determined that the surface of Mars northern residual cap is water ice. Many researchers have related observed atmospheric water vapor abundances to seasonal exchange between reservoirs such as the polar caps, but the extent to which the exchange between the surface and the atmosphere remains uncertain. Early studies of the ice coverage and albedo of the northern residual Martian polar cap using Mariner 9 and Viking images reported that there were substantial internannual differences in ice deposition on the polar cap, a result which suggested a highly variable Martian climate. However, some of the data used in these studies were obtained at differing values of heliocentric solar longitude (L(sub s)). Reevaluation of this dataset indicated that the residual cap undergoes seasonal brightening throughout the summer, and indicated that this process repeats from year to year. In this study we continue to compare Mariner 9 and Viking Orbiter imaging observations and thermal data of the north residual polar cap to data acquired with Mars Global Surveyor s Mars Orbiter Camera (MOC) instrument. In the current study, our goal is to examine all released data from MGS MOC in the northern summer season, along with applicable TES data in order to better understand the albedo variations in the northern summer and their implications on water transport. To date, work has focused primarily on the MOC dataset. In 1999, data acquisition of the northern polar regions began at L(sub s) = 107, although there was little north polar data acquired from L(sub s)= 107 to L(sub s) = 109. We examined a total of 409 images from L(sub s) = 107 to L(sub s)=148. We have also examined data from 2000 from L(sub s)= 93 to L(sub s)= 110; additional progress is ongoing. Here we present a progress report of our observations, and continue to determine their implications for the Martian water cycle.

  17. Performance of the SLC polarized electron source with high polarization

    International Nuclear Information System (INIS)

    Clendenin, J.E.; Alley, R.K.; Aoyagi, H.

    1993-04-01

    For the 1992 operating cycle of the SLAC Linear Collider (SLC), the polarized electron source (PES) during its maiden run successfully met the pulse intensity and overall efficiency requirements of the SLC. However, the polarization of the bulk GaAs cathode was low (∼27%) and the pulse-to-pulse stability was marginal. We have shown that adequate charge for the SLC can be extracted from a strained layer cathode having P e ∼80% even though the quantum efficiency (QE) is - beam stability. The performance of the PES during the 1993 SLC operating cycle with these and other improvements is discussed

  18. Polar metals by geometric design

    Science.gov (United States)

    Kim, T. H.; Puggioni, D.; Yuan, Y.; Xie, L.; Zhou, H.; Campbell, N.; Ryan, P. J.; Choi, Y.; Kim, J.-W.; Patzner, J. R.; Ryu, S.; Podkaminer, J. P.; Irwin, J.; Ma, Y.; Fennie, C. J.; Rzchowski, M. S.; Pan, X. Q.; Gopalan, V.; Rondinelli, J. M.; Eom, C. B.

    2016-05-01

    Gauss’s law dictates that the net electric field inside a conductor in electrostatic equilibrium is zero by effective charge screening; free carriers within a metal eliminate internal dipoles that may arise owing to asymmetric charge distributions. Quantum physics supports this view, demonstrating that delocalized electrons make a static macroscopic polarization, an ill-defined quantity in metals—it is exceedingly unusual to find a polar metal that exhibits long-range ordered dipoles owing to cooperative atomic displacements aligned from dipolar interactions as in insulating phases. Here we describe the quantum mechanical design and experimental realization of room-temperature polar metals in thin-film ANiO3 perovskite nickelates using a strategy based on atomic-scale control of inversion-preserving (centric) displacements. We predict with ab initio calculations that cooperative polar A cation displacements are geometrically stabilized with a non-equilibrium amplitude and tilt pattern of the corner-connected NiO6 octahedra—the structural signatures of perovskites—owing to geometric constraints imposed by the underlying substrate. Heteroepitaxial thin-films grown on LaAlO3 (111) substrates fulfil the design principles. We achieve both a conducting polar monoclinic oxide that is inaccessible in compositionally identical films grown on (001) substrates, and observe a hidden, previously unreported, non-equilibrium structure in thin-film geometries. We expect that the geometric stabilization approach will provide novel avenues for realizing new multifunctional materials with unusual coexisting properties.

  19. FHR Process Instruments

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, David Eugene [ORNL

    2015-01-01

    Fluoride salt-cooled High temperature Reactors (FHRs) are entering into early phase engineering development. Initial candidate technologies have been identified to measure all of the required process variables. The purpose of this paper is to describe the proposed measurement techniques in sufficient detail to enable assessment of the proposed instrumentation suite and to support development of the component technologies. This paper builds upon the instrumentation chapter of the recently published FHR technology development roadmap. Locating instruments outside of the intense core radiation and high-temperature fluoride salt environment significantly decreases their environmental tolerance requirements. Under operating conditions, FHR primary coolant salt is a transparent, low-vapor-pressure liquid. Consequently, FHRs can employ standoff optical measurements from above the salt pool to assess in-vessel conditions. For example, the core outlet temperature can be measured by observing the fuel s blackbody emission. Similarly, the intensity of the core s Cerenkov glow indicates the fission power level. Short-lived activation of the primary coolant provides another means for standoff measurements of process variables. The primary coolant flow and neutron flux can be measured using gamma spectroscopy along the primary coolant piping. FHR operation entails a number of process measurements. Reactor thermal power and core reactivity are the most significant variables for process control. Thermal power can be determined by measuring the primary coolant mass flow rate and temperature rise across the core. The leading candidate technologies for primary coolant temperature measurement are Au-Pt thermocouples and Johnson noise thermometry. Clamp-on ultrasonic flow measurement, that includes high-temperature tolerant standoffs, is a potential coolant flow measurement technique. Also, the salt redox condition will be monitored as an indicator of its corrosiveness. Both

  20. Planck 2015 results: VIII. High Frequency Instrument data processing: Calibration and maps

    DEFF Research Database (Denmark)

    Adam, R.; Ade, P. A R; Aghanim, N.

    2016-01-01

    This paper describes the processing applied to the cleaned, time-ordered information obtained from the Planck High Frequency Instrument (HFI) with the aim of producing photometrically calibrated maps in temperature and (for the first time) in polarization. The data from the entire 2.5-year HFI....... Finally, we discuss the major systematic effects and in particular the leakage induced by flux mismatch between the detectors that leads to spurious polarization signal....

  1. Polarization in electron and proton beams

    International Nuclear Information System (INIS)

    Buon, J.

    1986-03-01

    One first introduces the concept of polarization for spin 1/2 particle beams and discusses properties of spin kinetics in a stationary magnetic field. Then the acceleration of polarized protons in synchrotrons is studied with emphasis on depolarization when resonances are crossed and on the cures for reducing it. Finally, transverse polarization of electrons in storage rings is discussed as an equilibrium between polarizing and depolarizing effects of synchrotron radiation. Means for obtaining longitudinal polarization are also treated

  2. Photophysics of Curcumin excited state in toluene-polar solvent mixtures: Role of H-bonding properties of the polar solvent

    Energy Technology Data Exchange (ETDEWEB)

    Saini, R.K.; Das, K., E-mail: kaustuv@rrcat.gov.in

    2014-01-15

    Excited state dynamics of Curcumin in binary solvent mixtures of toluene and polar H-bonding solvents were compared by using an instrument endowed with 40 ps time resolution. The solvation time constant of Curcumin increases significantly (and can therefore be measured) in polar solvents which have, either, both H-bond donating and accepting ability, or, only H-bond donating ability. These results suggest that the rate limiting step in the excited state dynamics of the pigment might be the formation and reorganization of the intermolecular H-bonding between the keto group of the pigment and the H-bond donating moieties of the polar solvent. -- Highlights: • Excited state dynamics of Curcumin in a binary solvent mixture of toluene and three polar H-bonding solvents were compared. • The solvation time constant increases significantly with polar solvents having, H-bond donating and accepting, or, H-bond donating ability. • Observed results suggest that H-bonding property of polar solvent plays an important role in the excited state dynamics. • Intermolecular H-bonding between the keto group of the pigment and polar solvent may be the rate limiting step.

  3. Photophysics of Curcumin excited state in toluene-polar solvent mixtures: Role of H-bonding properties of the polar solvent

    International Nuclear Information System (INIS)

    Saini, R.K.; Das, K.

    2014-01-01

    Excited state dynamics of Curcumin in binary solvent mixtures of toluene and polar H-bonding solvents were compared by using an instrument endowed with 40 ps time resolution. The solvation time constant of Curcumin increases significantly (and can therefore be measured) in polar solvents which have, either, both H-bond donating and accepting ability, or, only H-bond donating ability. These results suggest that the rate limiting step in the excited state dynamics of the pigment might be the formation and reorganization of the intermolecular H-bonding between the keto group of the pigment and the H-bond donating moieties of the polar solvent. -- Highlights: • Excited state dynamics of Curcumin in a binary solvent mixture of toluene and three polar H-bonding solvents were compared. • The solvation time constant increases significantly with polar solvents having, H-bond donating and accepting, or, H-bond donating ability. • Observed results suggest that H-bonding property of polar solvent plays an important role in the excited state dynamics. • Intermolecular H-bonding between the keto group of the pigment and polar solvent may be the rate limiting step

  4. Instrumentation for environmental monitoring: biomedical

    International Nuclear Information System (INIS)

    1979-05-01

    An update is presented to Volume four of the six-volume series devoted to a survey of instruments useful for measurements in biomedicine related to environmental research and monitoring. Results of the survey are given as descriptions of the physical and operating characteristics of available instruments, critical comparisons among instrumentation methods, and recommendations of promising methodology and development of new instrumentation. Methods of detection and analysis of gaseous organic pollutants and metals, including Ni and As are presented. Instrument techniques and notes are included on atomic spectrometry and uv and visible absorption instrumentation

  5. ON THE ROTATION OF SUNSPOTS AND THEIR MAGNETIC POLARITY

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jianchuan; Yang, Zhiliang; Guo, Kaiming [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Wang, Haimin; Wang, Shuo, E-mail: zlyang@bnu.edu.cn [Space Weather Research Laboratory, New Jersey Institute of Technology, University Heights, Newark, NJ 07102-1982 (United States)

    2016-07-20

    The rotation of sunspots of 2 yr in two different solar cycles is studied with the data from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and the Michelson Doppler Imager instrument on board the Solar and Heliospheric Observataory . We choose the α sunspot groups and the relatively large and stable sunspots of complex active regions in our sample. In the year of 2003, the α sunspot groups and the preceding sunspots tend to rotate counterclockwise and have positive magnetic polarity in the northern hemisphere. In the southern hemisphere, the magnetic polarity and rotational tendency of the α sunspot groups and the preceding sunspots are opposite to the northern hemisphere. The average rotational speed of these sunspots in 2003 is about 0.°65 hr{sup 1}. From 2014 January to 2015 February, the α sunspot groups and the preceding sunspots tend to rotate clockwise and have negative magnetic polarity in the northern hemisphere. The patterns of rotation and magnetic polarity of the southern hemisphere are also opposite to those of the northern hemisphere. The average rotational speed of these sunspots in 2014/2015 is about 1.°49 hr{sup 1}. The rotation of the relatively large and stable preceding sunspots and that of the α sunspot groups located in the same hemisphere have opposite rotational direction in 2003 and 2014/2015.

  6. Frequency dependent polarization in blazars

    International Nuclear Information System (INIS)

    Bjoernsson, C.I.

    1984-10-01

    It is argued that the intrinsic frequency dependent polarization in blazars finds its most straightforward explanations in terms of a single rather than a multicomponent sourcemodel. In order to reproduce the observations, under the assumption that the emission mechanism is optically thin synchrotron radiation, both a well ordered magnetic field and an electron distribution with a sharp break or cuttoff are necessary. Non-uniform pitch angle distribution and/or environments where synchrotron losses are important are both conducive to producing strong frequency dependent polarization. Reasons are put forth as to why such conditions ar expected to occur in blazars. Two specific models are discussed in detail and it is shown that they are both able to produce strong frequency dependent polarization, even when the spectral index changes by a small amount only. (orig.)

  7. Report of the polarization group

    International Nuclear Information System (INIS)

    Ford, W.; Kondo, K.; Martin, F.; Manning, G.; Miller, D.; Prescott, C.

    1975-01-01

    The use of longitudinal polarization in the reaction e + e - → μ + μ - was studied. Modifications of the magnetic insertion which could reduce synchrotron radiation by two or more were considered. In addition, a specific design is suggested which incorporates the optimized magnetic configuration; it is assumed that no particle detection is necessary near the interaction vertex and the synchrotron radiation is ''dumped'' up - and downstream. Also considered were vacuum chambers in which the synchrotron radiation is absorbed locally so that shielded regions are provided for detectors near the interaction vertex. A scheme for rotating the polarization outside the experiment areas is detailed; in this way the design of experiments is greatly simplified. Local intense ionization of residual gas in the interaction region due to synchrotron radiation at the insertion was studied. Finally, some general considerations in the production and measurement of beam polarization are summarized. 2 figures

  8. Uses of laser optical pumping to produce polarized ion beams

    International Nuclear Information System (INIS)

    Anderson, L.W.

    1983-01-01

    Laser optical pumping can be used to produce polarized alkali atom beams or polarized alkali vapor targets. Polarized alkali atom beams can be converted into polarized alkali ion beams, and polarized alkali vapor targets can be used to produce polarized H - or 3 He - ion beams. In this paper the authors discuss how the polarized alkali atom beams and polarized alkali vapor targets are used to produce polarized ion beams with emphasis on the production of polarized negative ion beams

  9. Polarization-Dependent Multi-Functional Metamaterial as Polarization Filter, Transparent Wall and Circular Polarizer using Ring-Cross Resonator

    Directory of Open Access Journals (Sweden)

    Z. Zhang

    2017-09-01

    Full Text Available We propose a polarization-dependent multi-functional metamaterial using ring-cross resonator. Based on the analysis of surface current distributions induced by different polarized incidence, we demonstrate that the proposed metamaterial serves as a polarization filter, a transparent wall and a circular polarizer under different polarization normal incidence. Additionally, parameter analyses on the control of resonance are discussed to complementally explain the physical origin. Simulated results show that the proposed metamaterial functions as a polarization filter eliminating the x-polarization wave at 10.1 GHz and y-polarization wave at 14.3 GHz, a transparent wall transmitting both x-polarized and y-polarized incident waves at 12.6 GHz, and a broadband circular polarizer converting the +45° polarized (-45° polarized incident wave to the left (right handed circularly polarized wave from 10.8 to 12.8 GHz, respectively. Measured results agree well with the simulation and validate the performance of the proposed multifunctional metamaterial.

  10. Ultra-small-angle scattering with polarized neutrons

    International Nuclear Information System (INIS)

    Jericha, E.; Badurek, G.; Trinker, M.

    2007-01-01

    Ultra-small-angle neutron scattering (USANS) has been established as an effective technique for the study of structures in the micrometre range in recent years. Consequentially this method has been extended to magnetic structures of corresponding size. We present the instrument arrangement and first experimental results. The instrument itself is a double crystal diffractometer in Bonse-Hart configuration which takes advantage of the narrow angular width of the perfect crystal reflection to obtain an extremely high angular resolution of the scattering vector. The neutrons are loss-free polarized by permanent magnetic prisms located between the monochromator crystal and the sample. Neutrons with opposite polarization are separated to a large extent and their different scattering behaviour may be studied in a single measurement without additional manipulation of the neutron spin. In this manner we are able to separate the magnetic and nuclear contribution to the scattering. We present first exemplifying measurements on ferromagnetic rods and wires, and on soft-magnetic ribbons. Related experiments were performed at the USANS facility of the TRIGA reactor at the Vienna University of Technology and at the combined neutron interferometer/USANS instrument S18 at the ILL, Grenoble

  11. Ultra-small-angle scattering with polarized neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Jericha, E. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria)]. E-mail: jericha@ati.ac.at; Badurek, G. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria); Trinker, M. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria)

    2007-07-15

    Ultra-small-angle neutron scattering (USANS) has been established as an effective technique for the study of structures in the micrometre range in recent years. Consequentially this method has been extended to magnetic structures of corresponding size. We present the instrument arrangement and first experimental results. The instrument itself is a double crystal diffractometer in Bonse-Hart configuration which takes advantage of the narrow angular width of the perfect crystal reflection to obtain an extremely high angular resolution of the scattering vector. The neutrons are loss-free polarized by permanent magnetic prisms located between the monochromator crystal and the sample. Neutrons with opposite polarization are separated to a large extent and their different scattering behaviour may be studied in a single measurement without additional manipulation of the neutron spin. In this manner we are able to separate the magnetic and nuclear contribution to the scattering. We present first exemplifying measurements on ferromagnetic rods and wires, and on soft-magnetic ribbons. Related experiments were performed at the USANS facility of the TRIGA reactor at the Vienna University of Technology and at the combined neutron interferometer/USANS instrument S18 at the ILL, Grenoble.

  12. Polarized electroluminescence from silicon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Bagraev, Nikolay; Danilovsky, Eduard; Gets, Dmitry; Klyachkin, Leonid; Kudryavtsev, Andrey; Kuzmin, Roman; Malyarenko, Anna [Ioffe Physical-Technical Institute, 194021 St. Petersburg (Russian Federation); Mashkov, Vladimir [St. Petersburg State Polytechnical University, 195251 St. Petersburg (Russian Federation)

    2012-05-15

    We present the first findings of the circularly polarized electroluminescence (CPEL) from silicon nanostructures which are the p-type ultra-narrow silicon quantum well (Si-QW) confined by {delta}-barriers heavily doped with boron. The CPEL dependences on the forward current and lateral electric field show the circularly polarized light emission which appears to be caused by the exciton recombination through the negative-U dipole boron centers at the Si-QW-{delta}-barriers interface with the assistance of phosphorus donors. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. All-fiber polarization switch

    Science.gov (United States)

    Knape, Harald; Margulis, Walter

    2007-03-01

    We report an all-fiber polarization switch made out of silica-based microstructured fiber suitable for Q-switching all-fiber lasers. Nanosecond high-voltage pulses are used to heat and expand an internal electrode to cause λ/2-polarization rotation in less than 10 ns for 1.5 μm light. The 10 cm long component has an experimentally measured optical insertion loss of 0.2 dB and a 0-10 kHz repetition frequency capacity and has been durability tested for more than 109 pulses.

  14. The sensitivity of income polarization

    DEFF Research Database (Denmark)

    Hussain, Azhar

    2009-01-01

    This study looks at polarization and its components' sensitivity to assumptions about equivalence scales, income definition, ethical income distribution parameters, and the income accounting period. A representative sample of Danish individual incomes from 1984 to 2002 is utilised. Results show...... that polarization has increased over time, regardless of the applied measure, when the last part of the period is compared to the first part of the period; primary causes being increased inequality (alienation) and faster income growth among high incomes relative to those in the middle of the distribution...

  15. Graphics of polar figure; Graficado de figura polar

    Energy Technology Data Exchange (ETDEWEB)

    Macias B, L.R

    1991-11-15

    The objective of this work, is that starting from a data file coming from a spectra that has been softened, and of the one that have been generated its coordinates to project it in stereographic form, to create the corresponding polar figure making use of the Cyber computer of the ININ by means of the GRAPHOS package. This work only requires a Beta, Fi and Intensity (I) enter data file. It starts of the existence of a softened spectra of which have been generated already with these data, making use of some language that in this case was FORTRAN for the Cyber computer, a program is generated supported in the Graphos package that allows starting of a reading of the Beta, Fi, I file, to generate the points in a stereographic projection and that it culminates with the graph of the corresponding polar figure. The program will request the pertinent information that is wanted to capture in the polar figure just as: date, name of the enter file, indexes of the polar figure, number of levels, radio of the stereographic projection (cms.), crystalline system to which belongs the sample, name the neuter graph file by create and to add the own general data. (Author)

  16. ZBLAN Viscosity Instrumentation

    Science.gov (United States)

    Kaukler, William

    2001-01-01

    The past year's contribution from Dr. Kaukler's experimental effort consists of these 5 parts: a) Construction and proof-of-concept testing of a novel shearing plate viscometer designed to produce small shear rates and operate at elevated temperatures; b) Preparing nonlinear polymeric materials to serve as standards of nonlinear Theological behavior; c) Measurements and evaluation of above materials for nonlinear rheometric behavior at room temperature using commercial spinning cone and plate viscometers available in the lab; d) Preparing specimens from various forms of pitch for quantitative comparative testing in a Dynamic Mechanical Analyzer, Thermal Mechanical Analyzer; and Archeological Analyzer; e) Arranging to have sets of pitch specimens tested using the various instruments listed above, from different manufacturers, to form a baseline of the viscosity variation with temperature using the different test modes offered by these instruments by compiling the data collected from the various test results. Our focus in this project is the shear thinning behavior of ZBLAN glass over a wide range of temperature. Experimentally, there are no standard techniques to perform such measurements on glasses, particularly at elevated temperatures. Literature reviews to date have shown that shear thinning in certain glasses appears to occur, but no data is available for ZBLAN glass. The best techniques to find shear thinning behavior require the application of very low rates of shear. In addition, because the onset of the thinning behavior occurs at an unknown elevated temperature, the instruments used in this study must provide controlled low rates of shear and do so for temperatures approaching 600 C. In this regard, a novel shearing parallel plate viscometer was designed and a prototype built and tested.

  17. Circular Polarization of Light By Planet Mercury and Enantiomorphism of Its Surface Minerals

    Science.gov (United States)

    Meierhenrich, U. J.; Thiemann, W. H.-P.; Barbier, B.; Brack, A.; Nahon, L.; Alcaraz, C.; Wolstencroft, R.

    Different mechanisms for the generation of circular polarization on the surface of planets and satellites are described. The observed values for Venus, the Moon, Mars, and Jupiter obtained by photo-polarimetric measurements with Earth based telescopes, showed accordance with theory. However, for planet Mercury asymmetric parameters in the circular polarization were measured that do not fit with calculations. For Bepi- Colombo, we propose to investigate this phenomenon using a concept which includes two instruments. The first instrument is a high-resolution optical polarimeter,[1,2] ca- pable to determine and map the circular polarization by remote scanning of Mercury's surface from the Mercury Planetary Orbiter MPO. The second instrument is an in situ sensor for the detection of the enantiomorphism of surface crystals and minerals, proposed to be included in the Mercury Lander MSE. [1] C. Alcaraz, R. Thissen, M. Compin, A. Jolly, M. Drescher, L. Nahon: First po- larization measurements of Ophelie: a versatile polarization VUV undulator at Super- Aco. SPIE 3773 (1999), 250-261. [2] C. Alcaraz, J.L. Marlats, D. Nether, B. Pilette, L. Nahon: A dedicated precise polarimeter for measurement of VUV versatile photon polarizations, Applied Optics, manuscript under preparation.

  18. Analysis of polarization introduced due to the telescope optics of the Thirty Meter Telescope

    Science.gov (United States)

    Anche, Ramya Manjunath; Sen, Asoke Kumar; Anupama, Gadiyara Chakrapani; Sankarasubramanian, Kasiviswanathan; Skidmore, Warren

    2018-01-01

    An analytical model has been developed to estimate the polarization effects, such as instrumental polarization (IP), crosstalk (CT), and depolarization, due to the optics of the Thirty Meter Telescope. These are estimated for the unvignetted field-of-view and the wavelengths of interest. The model estimates an IP of 1.26% and a CT of 44% at the Nasmyth focus of the telescope at the wavelength of 0.6 μm at field angle zero with the telescope pointing to zenith. Mueller matrices have been estimated for the primary, secondary, and Nasmyth mirrors. It is found that some of the Mueller matrix elements of the primary and secondary mirrors show a fourfold azimuthal antisymmetry, which indicates that the polarization at the Cassegrain focus is negligible. At the inclined Nasmyth mirror, there is no azimuthal antisymmetry in the matrix elements, and this results in nonzero values for IP and CT, which would negatively impact the polarization measurements at the telescope focus. The averaged Mueller matrix is estimated at the Nasmyth focus at different instrument ports and various zenith angles of the telescope. The variation in the Mueller matrix elements for different coatings is also estimated. The impact of this polarization effect on the science case requirements has been discussed. This analysis will help in achieving precise requirements for future instruments with polarimetric capability.

  19. Radiation Budget Instrument (RBI) for JPSS-2

    Science.gov (United States)

    Georgieva, Elena; Priestley, Kory; Dunn, Barry; Cageao, Richard; Barki, Anum; Osmundsen, Jim; Turczynski, Craig; Abedin, Nurul

    2015-01-01

    Radiation Budget Instrument (RBI) will be one of five instruments flying aboard the JPSS-2 spacecraft, a polar-orbiting sun-synchronous satellite in Low Earth Orbit. RBI is a passive remote sensing instrument that will follow the successful legacy of the Clouds and Earth's Radiant Energy System (CERES) instruments to make measurement of Earth's short and longwave radiation budget. The goal of RBI is to provide an independent measurement of the broadband reflected solar radiance and Earth's emitted thermal radiance by using three spectral bands (Shortwave, Longwave, and Total) that will have the same overlapped point spread function (PSF) footprint on Earth. To ensure precise NIST-traceable calibration in space the RBI sensor is designed to use a visible calibration target (VCT), a solar calibration target (SCT), and an infrared calibration target (ICT) containing phase change cells (PCC) to enable on-board temperature calibration. The VCT is a thermally controlled integrating sphere with space grade Spectralon covering the inner surface. Two sides of the sphere will have fiber-coupled laser diodes in the UV to IR wavelength region. An electrical substitution radiometer on the integrating sphere will monitor the long term stability of the sources and the possible degradation of the Spectralon in space. In addition the radiometric calibration operations will use the Spectralon diffusers of the SCT to provide accurate measurements of Solar degradation. All those stable on-orbit references will ensure that calibration stability is maintained over the RBI sensor lifetime. For the preflight calibration the RBI will view five calibration sources - two integrating spheres and three CrIS (Cross-track Infrared Sounder ) -like blackbodies whose outputs will be validated with NIST calibration approach. Thermopile are the selected detectors for the RBI. The sensor has a requirement to perform lunar calibration in addition to solar calibration in space in a way similar to CERES

  20. Diamonds for beam instrumentation

    International Nuclear Information System (INIS)

    Griesmayer, Erich

    2013-01-01

    Diamond is perhaps the most versatile, efficient and radiation tolerant material available for use in beam detectors with a correspondingly wide range of applications in beam instrumentation. Numerous practical applications have demonstrated and exploited the sensitivity of diamond to charged particles, photons and neutrons. In this paper, a brief description of a generic diamond detector is given and the interaction of the CVD diamond detector material with protons, electrons, photons and neutrons is presented. Latest results of the interaction of sCVD diamond with 14 MeV mono-energetic neutrons are shown.

  1. Biomagnetic instrumentation and measurement

    Science.gov (United States)

    Iufer, E. J.

    1978-01-01

    The instruments and techniques of biomagnetic measurement have progressed greatly in the past 15 years and are now of a quality appropriate to clinical applications. The paper reports on recent developments in the design and application of SQUID (Superconducting Quantum Interference Device) magnetometers to biomagnetic measurement. The discussion covers biomagnetic field levels, magnetocardiography, magnetic susceptibility plethysmography, ambient noise and sensor types, principles of operation of a SQUID magnetometer, and laboratory techniques. Of the many promising applications of noninvasive biomagnetic measurement, magnetocardiography is the most advanced and the most likely to find clinical application in the near future.

  2. Maintenance of nuclear instruments

    International Nuclear Information System (INIS)

    Oliveira Rebelo, A.M. de; Santos, C.J.F. dos; Jesus, E.F.O. de; Silva, L.E.M.C.; Borges, J.C.

    1988-01-01

    A program to design and repairing of nuclear instruments for teaching and research was founded in the UFRJ to find solutions for technical support problem - The GEMD-RADIACOES. This group has assisted to several groups of the University in recuperation and conservation of devices like: Linear scanner, Cromatograph and system of radiation detection in general. Recuperation of these devices had required a study of theirs operations modes, to make it possible the setting up of a similar system. Recuperation also involves operation tests, calibration and technical for users, orienting them to get the best performance. (Author) [pt

  3. Payment Instrument Characteristics

    DEFF Research Database (Denmark)

    Holst, Jacques; Kjeldsen, Martin; Hedman, Jonas

    2015-01-01

    Over the last decade, we have witnessed payment innovations that fundamentally have changed the ways we pay. Payment innovations, such as mobile payments and on-line banking, include characteristics or features that are essential to understand if we want to know how and why payers choose among...... payment innovations. Using the Repertory Grid technique to explore 15 payers’ perception of six payment instruments, including coins, banknotes, debit cards, credit cards, mobile payments, and on-line banking, we identify 16 payment characteristics. The characteristics aggregate seventy-six unique...

  4. Instrumentation for tomograph positioning

    International Nuclear Information System (INIS)

    Frenkel, A.D.B.; Castello Branco, L.M.; Reznik, D.S.; Santos, C.A.C.; Borges, J.C.

    1986-01-01

    The COPPE's Nuclear Instrumentation Lab. has been developing researches directed towards the implementation of a Computer-Based Tomography System. Basically, the system reported in this paper can be divided into three major parts: the mechanical part, responsible for the physical movement (Stepper-Motors, table, etc.); the electronic part, which controls the mechanical part and handles the data-acquisition process (microcomputer, interfaces, etc.); and finally, the support of a software-oriented system, including control programs and information processing routines. (Author) [pt

  5. Pesticide reducing instruments

    DEFF Research Database (Denmark)

    Jacobsen, Lars-Bo; Jensen, Jørgen Dejgård; Andersen, Martin

    2005-01-01

    of a key species of farmland bird, caused to changes in production and landscape. The results from the agricultural sector model are also used in evaluation of pesticide usage and the leaching of pesticides to ground water. First we analyze the implication of three different scenarios in all of the above...... for improving bio-diversity and securing drinking water. That is, combining economic modeling with physical biological modeling and geological evaluation allows us to select unsprayed field margins as the most effective instrument. Sensitivity analysis conducted on bio-diversity suggest that this result...

  6. Leir beam instrumentation

    CERN Document Server

    Bal, C; Burger, S; Dutriat, C; Gasior, M; Lefèvre, T; Lenardon, F; Odier, P; Raich, U; Soby, L; Tan, J; Tranquille, G; Vuitton, C

    2005-01-01

    The Low Energy Ion Ring (LEIR) is central to the “Ions for LHC” project. Its role is to transform a serie of long low intensity ion pulses from Linac 3, into short high density pulses, which will be further accelerated in the PS and SPS rings, before injection into LHC. To do so the injected pulses are stacked and phase space cooled using electron cooling, before acceleration to the ejection energy of 72 MEV/u. This note describes different types of instruments which will be installed in the LEIR ring and transfer lines.

  7. Calibration of "Babyline" RP instruments

    CERN Multimedia

    2015-01-01

      If you have old RP instrumentation of the “Babyline” type, as shown in the photo, please contact the Radiation Protection Group (Joffrey Germa, 73171) to have the instrument checked and calibrated. Thank you. Radiation Protection Group

  8. Nuclear instrumentation for research reactors

    International Nuclear Information System (INIS)

    Hofer, Carlos G.; Pita, Antonio; Verrastro, Claudio A.; Maino, Eduardo J.

    1997-01-01

    The nuclear instrumentation for research reactors in Argentina was developed in 70'. A gradual modernization of all the nuclear instrumentation is planned. It includes start-up and power range instrumentation, as well as field monitors, clamp, scram and rod movement control logic. The new instrumentation is linked to a computer network, based on real time operating system for data acquisition, display and logging. This paper describes the modules and whole system aspects. (author). 2 refs

  9. Calibration philosophy for reactor instrumentation

    International Nuclear Information System (INIS)

    Saroja, A.R.; Ilango Sambasivan, S.; Swaminathan, P.

    2004-01-01

    All electronic test and measuring systems and process control instruments constitute a critical and important area of instrumentation in the nuclear and conventional power plant, process plant and research laboratories. All these instruments need periodic calibration. Therefore standards laboratories is one of the essential tools in enforcing quality. Calibration of these instruments plays a vital role in the performance, reliability, and quality of the target to be achieved. Thus calibration is a must if need speed and quality. (author)

  10. PC Calibration of Measuring Instrument

    OpenAIRE

    Gold, Ayoola

    2015-01-01

    Calibration involves the adjustment of measuring instruments basically by comparing the values obtained from a measuring instrument with a standard instrument whose output value is known. This project is focused at developing an application used to calibrate measuring instruments (oscilloscope) in the laboratory. This application eases the traditional inputting of output value manually from the calibrator (Fluke 5500A in this case) to the oscilloscope (Agilent DSO5012A oscilloscope in this ca...

  11. UC Merced NMR Instrumentation Acquisition

    Science.gov (United States)

    2015-06-18

    UC Merced NMR Instrumentation Acquisition For the UC Merced NMR Instrumentation Acquisition proposal, a new 400 MHz and an upgraded 500 MHz NMR...valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. University of California - Merced 5200 North Lake Road Merced , CA 95343...UC Merced NMR Instrumentation Acquisition Report Title For the UC Merced NMR Instrumentation Acquisition proposal, a new 400 MHz and an upgraded 500

  12. Illumination Conditions of the Lunar Polar Regions Using LOLA Topography

    Science.gov (United States)

    Mazarico, E.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.; Torrence, M. H.

    2011-01-01

    We use high-resolution altimetry data obtained by the Lunar Orbiter Laser Altimeter instrument onboard the Lunar Reconnaissance Orbiter to characterize present illumination conditions in the polar regions of the Moon. Compared to previous studies, both the spatial and temporal extent of the simulations are increased significantly, as well as the coverage (fill ratio) of the topographic maps used, thanks to the 28 Hz firing rate of the five-beam instrument. We determine the horizon elevation in a number of directions based on 240 m-resolution polar digital elevation models reaching down to 75 latitude. The illumination of both polar regions extending to 80 can be calculated for any geometry from those horizon longitudinal profiles. We validated our modeling with recent Lunar Reconnaissance Orbiter Wide-Angle Camera images. We assessed the extent of permanently shadowed regions (PSRs, defined as areas that never receive direct solar illumination), and obtained total areas generally larger than previous studies (12,866 and 16,055 km2, in the north and south respectively). We extended our direct illumination model to account for singly-scattered light, and found that every PSR does receive some amount of scattered light during the year. We conducted simulations over long periods (several 18.6-years lunar precession cycles) with a high temporal resolution (6 h), and identified the most illuminated locations in the vicinity of both poles. Because of the importance of those sites for exploration and engineering considerations, we characterized their illumination more precisely over the near future. Every year, a location near the Shackleton crater rim in the south polar region is sunlit continuously for 240 days, and its longest continuous period in total darkness is about 1.5 days. For some locations small height gains ( 10 m) can dramatically improve their average illumination and reduce the night duration, rendering some of those particularly attractive energy-wise as

  13. High‐frequency induced polarization measurements of hydrocarbon‐bearing rocks

    DEFF Research Database (Denmark)

    Burtman, Vladimir; Endo, Masashi; Zhdanov, Michael S.

    2011-01-01

    We have investigated induced polarization (IP) effects in hydrocarbon‐bearing artificial rocks at frequencies greater than 100 Hz. We have examined the instrumental and electrode phase responses of Zonge International's complex resistivity (CR) system, and optimized the performance of the Zonge s......, and suggest the necessity to account for IP effects in the interpretations of electromagnetic data, particularly in induction logging data....

  14. Dynamically polarized samples for neutron protein crystallography at the Spallation Neutron Source

    Science.gov (United States)

    Zhao, Jinkui; Pierce, Josh; Myles, Dean; Robertson, J. L.; Herwig, Kenneth W.; Standaert, Bob; Cuneo, Matt; Li, Le; Meilleur, Flora

    2016-09-01

    To prepare for the next generation neutron scattering instruments for the planned second target station at the Spallation Neutron Source (SNS) and to broaden the scientific impact of neutron protein crystallography at the Oak Ridge National Laboratory, we have recently ramped up our efforts to develop a dynamically polarized target for neutron protein crystallography at the SNS. Proteins contain a large amount of hydrogen which contributes to incoherent diffraction background and limits the sensitivity of neutron protein crystallography. This incoherent background can be suppressed by using polarized neutron diffraction, which in the same time also improves the coherent diffraction signal. Our plan is to develop a custom Dynamic Nuclear Polarization (DNP) setup tailored to neutron protein diffraction instruments. Protein crystals will be polarized at a magnetic field of 5 T and temperatures of below 1 K. After the dynamic polarization process, the sample will be brought to a frozen-spin mode in a 0.5 T holding field and at temperatures below 100 mK. In a parallel effort, we are also investigating various ways of incorporating polarization agents needed for DNP, such as site specific spin labels, into protein crystals.

  15. Incore instrument device

    International Nuclear Information System (INIS)

    Sakima, Naoki

    1996-01-01

    An incore instrument device has an integrally disposed touch panel having a function of displaying an operation indication method such as for setting of conditions for incore measurement and information processing and results of the incore measurement and a function capable of conducting operation indication such as for setting conditions and information processing for incore measurement relative to a control section upon touching an information position on a displayed information. In addition, an information processing section comprising a man-machine function program formed so as to recognize the content of the operation indication for the incore measurement by touching and let the control section to conduct it is disposed to the outside by way of a communication interface. In addition, a programming device is disposed for forming and rewriting the program of the man-machine function relative to the information processing section. Then, when various indication operations are conducted upon performing incore measurement, a view point can be concentrated to one predetermined point thereby enabling to improve the operationability without danger. In addition, the programming of the man-machine function does not apply unnecessary load to the control section in the incore instrumentation device. (N.H.)

  16. Balances instruments, manufacturers, history

    CERN Document Server

    Robens, Erich; Kiefer, Susanne

    2014-01-01

    The book deals mainly with direct mass determination by means of a conventional balances. It covers the history of the balance from the beginnings in Egypt earlier than 3000 BC to recent developments. All balance types are described with emphasis on scientific balances. Methods of indirect mass determination, which are applied to very light objects like molecules and the basic particles of matter and celestial bodies, are included.  As additional guidance, today’s manufacturers are listed and the profile of important companies is reviewed. Several hundred photographs, reproductions and drawings show instruments and their uses. This book includes commercial weighing instruments for merchandise and raw materials in workshops as well as symbolic weighing in the ancient Egyptian’s ceremony of ‘Weighing of the Heart’, the Greek fate balance, the Roman  Justitia, Juno Moneta and Middle Ages scenes of the Last Judgement with Jesus or St. Michael and of modern balances. The photographs are selected from the...

  17. PASSCAL Instrument Center Support for Cryoseismology: Methodologies, Challenges, Development and Instrumentation

    Science.gov (United States)

    Beaudoin, B. C.; Anderson, K. R.; Bilek, S. L.; Carpenter, P.; Childs, D.; Chung, P.; Huerta, A. D.; Lingutla, N.; Nikolaus, K.; Winberry, J. P.

    2017-12-01

    Remote portable seismic stations are, in most cases, constrained by logistics and cost. High latitude operations introduce environmental, technical and logistical challenges that require substantially more engineering work to ensure robust, high quality data return. Since 2006, IRIS PASSCAL has been funded by NSF to develop, deploy, and maintain a pool of polar specific seismic stations. At roughly the same time, PASSCAL began supporting experiments specifically targeting glacier dynamics such as the mechanisms of subglacial hydrology, basal shear stress, ice stream stick slip mechanisms, and glacier seismicity. Although much of the development for high-latitude deployments was directly applicable to cryoseismology, these new experiments introduced a unique series of challenges including high ablation, standing water, and moving stations. Our polar development objectives have focused on: Reducing station power requirements, size and weight; Extending the operational temperature of a station; Simplifying logistics; Engineering solutions that are cost effective, manufacturable, serviceable and reusable; And, developing high-latitude communications for both state-of-health and data transmission. To these ends, PASSCAL continues testing new power storage technology, refining established power systems for lighter and smaller power banks, and exploring telemetry solutions to increase high-bandwidth communication options and abilities for remote seismic stations. Further enhancing PASSCAL's ability to support cryoseismology is a recent NSF funded collaborative effort lead by Central Washing University joined by IRIS and New Mexico Tech to build a Geophysical Earth Observatory for Ice Covered Environments (GEOICE). The GEOICE instrument, power system and other integrated ancillary components are designed to require minimal installation time and logistical load (i.e., size and weight), while maximizing ease-of-use in the field and optimizing costs of instrumentation and

  18. Rio de Janeiro: Instrumentation school

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Students from Latin America were able to get hands-on experience in state-of-the-art physics instrumentation in this year's School on Instrumentation for High Energy Physics organized by the active Instrumentation Panel of ICFA (the International Committee for Future Accelerators) at the Centro Brasileiro de Pesquicas Fisicas (CBPF), Rio de Janeiro, in July

  19. Instrument Remote Control via the Astronomical Instrument Markup Language

    Science.gov (United States)

    Sall, Ken; Ames, Troy; Warsaw, Craig; Koons, Lisa; Shafer, Richard

    1998-01-01

    The Instrument Remote Control (IRC) project ongoing at NASA's Goddard Space Flight Center's (GSFC) Information Systems Center (ISC) supports NASA's mission by defining an adaptive intranet-based framework that provides robust interactive and distributed control and monitoring of remote instruments. An astronomical IRC architecture that combines the platform-independent processing capabilities of Java with the power of Extensible Markup Language (XML) to express hierarchical data in an equally platform-independent, as well as human readable manner, has been developed. This architecture is implemented using a variety of XML support tools and Application Programming Interfaces (API) written in Java. IRC will enable trusted astronomers from around the world to easily access infrared instruments (e.g., telescopes, cameras, and spectrometers) located in remote, inhospitable environments, such as the South Pole, a high Chilean mountaintop, or an airborne observatory aboard a Boeing 747. Using IRC's frameworks, an astronomer or other scientist can easily define the type of onboard instrument, control the instrument remotely, and return monitoring data all through the intranet. The Astronomical Instrument Markup Language (AIML) is the first implementation of the more general Instrument Markup Language (IML). The key aspects of our approach to instrument description and control applies to many domains, from medical instruments to machine assembly lines. The concepts behind AIML apply equally well to the description and control of instruments in general. IRC enables us to apply our techniques to several instruments, preferably from different observatories.

  20. Measurement of inclusive quasielastic scattering of polarized electrons from polarized 3He

    International Nuclear Information System (INIS)

    Woodward, C.E.; Beise, E.J.; Belz, J.E.; Carr, R.W.; Filippone, B.W.; Lorenzon, W.B.; McKeown, R.D.; Mueller, B.; O'Neill, T.G.; Dodson, G.; Dow, K.; Farkhondeh, M.; Kowalski, S.; Lee, K.; Makins, N.; Milner, R.; Thompson, A.; Tieger, D.; van den Brand, J.; Young, A.; Yu, X.; Zumbro, J.

    1990-01-01

    We report a measurement of the asymmetry in spin-dependent quasielastic scattering of longitudinally polarized electrons from a polarized 3 He gas target. This measurement represents the first demonstration of a new method for studying electromagnetic nuclear structure: the scattering of polarized electrons from a polarized nuclear target. The measured asymmetry is in good agreement with a Faddeev calculation and supports the picture of spin-dependent quasielastic scattering from polarized 3 He as predominantly scattering from a polarized neutron