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Sample records for polarization interferometry dpi

  1. Determining ERβ Binding Affinity to Singly Mutant ERE Using Dual Polarization Interferometry

    Science.gov (United States)

    Song, Hong Yan; Su, Xiaodi

    In a classic mode of estrogen action, estrogen receptors (ERs) bind to estrogen responsive element (ERE) to activate gene transcription. A perfect ERE contains a 13-base pair sequence of a palindromic repeat separated by a three-base spacer, 5‧-GGTCAnnnTGACC-3‧. In addition to the consensus or wild-type ERE (wtERE), naturally occurring EREs often have one or two base pairs’ alternation. Based on the newly constructed Thermodynamic Modeling of ChIP-seq (TherMos) model, binding energy between ERβ and a series of 34-bp mutant EREs (mutERE) was simulated to predict the binding affinity between ERs and EREs with single base pair deviation at different sites of the 13-bp inverted sequence. Experimentally, dual polarization interferometry (DPI) method was developed to measure ERβ-mutEREs binding affinity. On a biotin-NeutrAvidin (NA)-biotin treated DPI chip, wtERE is immobilized. In a direct binding assay, ERβ-wtERE binding affinity is determined. In a competition assay, ERβ was preincubated with mutant EREs before being added for competitive binding to the immobilized wtERE. This competition strategy provided a successful platform to evaluate the binding affinity variation among large number of ERE with different base mutations. The experimental result correlates well with the mathematically predicted binding energy with a Spearman correlation coefficient of 0.97.

  2. A new polarized neutron interferometry facility at the NCNR

    Energy Technology Data Exchange (ETDEWEB)

    Shahi, C.B. [Physics and Engineering Physics Department, Tulane University, New Orleans, LA 70188 (United States); Arif, M. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Cory, D.G. [Department of Chemistry, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Perimeter Institute for Theoretical Physics, Waterloo, ON, Canada N2L 2Y5 (Canada); Institute for Quantum Computing, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Canadian Institute for Advanced Research, Toronto, ON, Canada M5G 1Z8 (Canada); Mineeva, T. [Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Canadian Institute for Advanced Research, Toronto, ON, Canada M5G 1Z8 (Canada); Nsofini, J.; Sarenac, D. [Institute for Quantum Computing, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Williams, C.J. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Huber, M.G., E-mail: michael.huber@nist.gov [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Pushin, D.A., E-mail: dmitry.pushin@uwaterloo.ca [Institute for Quantum Computing, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada)

    2016-03-21

    A new monochromatic beamline and facility has been installed at the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR) devoted to neutron interferometry in the research areas of spin control, spin manipulation, quantum mechanics, quantum information science, spintronics, and material science. This facility is possible in part because of advances in decoherence free subspace interferometer designs that have demonstrated consistent contrast in the presence of vibrational noise; a major environmental constraint that has prevented neutron interferometry from being applied at other neutron facilities. Neutron interferometry measures the phase difference between a neutron wave function propagating along two spatially separated paths. It is a practical example of self interference and due to its modest path separation of a few centimeters allows the insertion of samples and macroscopic neutron spin rotators. Phase shifts can be caused by gravitational, magnetic and nuclear interactions as well as purely quantum mechanical effects making interferometer a robust tool in neutron research. This new facility is located in the guide hall of the NCNR upstream of the existing Neutron Interferometry and Optics Facility (NIOF) and has several advantages over the NIOF including higher incident flux, better neutron polarization, and increased accessibility. The long term goal for the new facility is to be a user supported beamline and makes neutron interferometer more generally available to the scientific community. This paper addresses both the capabilities and characteristics of the new facility.

  3. Evolution of oil/water interface in the presence of SDBS detected by dual polarization interferometry

    Science.gov (United States)

    Duan, Ming; Ding, Ziling; Wang, Hu; Xiong, Yan; Fang, Shenwen; Shi, Peng; Liu, Shuai

    2018-01-01

    In this work, the technique of dual polarization interferometry (DPI) was applied to establish a new method to monitor the real-time evolution of oil/water interface in the presence of sodium dodecyl benzene sulfonate (SDBS) at molecular level. A three-stage model of adsorption-desorption-detachment had been proposed and was systematically discussed upon the addition of different SDBS concentrations based on the variation of the interfacial mass with time. The results demonstrated two patterns of adsorption morphology at the oil/water interface, SDBS mono-molecules and SDBS hemi-micelles at SDBS concentrations below and above cmc respectively according to the relaxation time obtained by theoretical model and the reaction order calculated by integral method in the analysis of adsorbed dynamics. The capability of oil detachment with the aid of SDBS as well as the properties of the outlet fluid were investigated under two patterns of adsorption morphologies, which showed different effects of oil detachment with the aid of SDBS molecules. The speed of oil detachment and the fluorescence intensity of the outlet fluid during the detachment process indicated the fact that the oil detachment capability was significantly promoted by the morphology of the absorbed hemi-micelles. The findings in the present study are crucial for fully understanding the interfacial behavior of surfactants applied in oil/water interface, which is of great significance in enhanced oil recovery and pollution industry.

  4. On the use of polarization modulation in combined interferometry and polarimetry

    International Nuclear Information System (INIS)

    Segre, S.E.

    1998-01-01

    The combination of interferometry and polarimetry using modulation of the input polarization is considered. For this case an expression for the interferometric phase is derived showing the presence of an additional time-varying term with respect to the case without modulation. It is found that for finite plasma birefringence the additional term is always important even if a linear input polarization is used, in contrast to the case where birefringence is zero. If the contribution of the additional term is eliminated by filtering, a consequence is a loss of time resolution on the interferometric measurement. (author)

  5. Buildup of polyelectrolyte multilayers of polyethyleneimine and microfibrillated cellulose studied by in situ dual-polarization interferometry and quartz crystal microbalance with dissipation.

    Science.gov (United States)

    Aulin, Christian; Varga, Imre; Claesson, Per M; Wågberg, Lars; Lindström, Tom

    2008-03-18

    Polyethyleneimine (PEI) and Microfibrillated cellulose (MFC) have been used to buildup polyelectrolyte multilayers (PEM) on silicone oxide and silicone oxynitride surfaces at different pH values and with different electrolyte and polyelectrolyte/colloid concentrations of the components. Consecutive adsorption on these surfaces was studied by in situ dual-polarization interferometry (DPI) and quartz crystal microbalance measurements. The adsorption data obtained from both the techniques showed a steady buildup of multilayers. High pH and electrolyte concentration of the PEI solution was found to be beneficial for achieving a high adsorbed amount of PEI, and hence of MFC, during the buildup of the multilayer. On the other hand, an increase in the electrolyte concentration of the MFC dispersion was found to inhibit the adsorption of MFC onto PEI. The adsorbed amount of MFC was independent of the bulk MFC concentration in the investigated concentration range (15-250 mg/L). Atomic force microscopy measurements were used to image a MFC-treated silicone oxynitride chip from DPI measurements. The surface was found to be almost fully covered by randomly oriented microfibrils after the adsorption of only one bilayer of PEI/MFC. The surface roughness expressed as the rms-roughness over 1 microm2 was calculated to be 4.6 nm (1 bilayer). The adsorbed amount of PEI and MFC and the amount of water entrapped by the individual layers in the multilayer structures were estimated by combining results from the two analytical techniques using the de Feijter formula. These results indicate a total water content of ca. 41% in the PEM.

  6. States of maximum polarization for a quantum light field and states of a maximum sensitivity in quantum interferometry

    International Nuclear Information System (INIS)

    Peřinová, Vlasta; Lukš, Antonín

    2015-01-01

    The SU(2) group is used in two different fields of quantum optics, the quantum polarization and quantum interferometry. Quantum degrees of polarization may be based on distances of a polarization state from the set of unpolarized states. The maximum polarization is achieved in the case where the state is pure and then the distribution of the photon-number sums is optimized. In quantum interferometry, the SU(2) intelligent states have also the property that the Fisher measure of information is equal to the inverse minimum detectable phase shift on the usual simplifying condition. Previously, the optimization of the Fisher information under a constraint was studied. Now, in the framework of constraint optimization, states similar to the SU(2) intelligent states are treated. (paper)

  7. Mach-Zehnder interferometry using spin- and valley-polarized quantum Hall edge states in graphene.

    Science.gov (United States)

    Wei, Di S; van der Sar, Toeno; Sanchez-Yamagishi, Javier D; Watanabe, Kenji; Taniguchi, Takashi; Jarillo-Herrero, Pablo; Halperin, Bertrand I; Yacoby, Amir

    2017-08-01

    Confined to a two-dimensional plane, electrons in a strong magnetic field travel along the edge in one-dimensional quantum Hall channels that are protected against backscattering. These channels can be used as solid-state analogs of monochromatic beams of light, providing a unique platform for studying electron interference. Electron interferometry is regarded as one of the most promising routes for studying fractional and non-Abelian statistics and quantum entanglement via two-particle interference. However, creating an edge-channel interferometer in which electron-electron interactions play an important role requires a clean system and long phase coherence lengths. We realize electronic Mach-Zehnder interferometers with record visibilities of up to 98% using spin- and valley-polarized edge channels that copropagate along a pn junction in graphene. We find that interchannel scattering between same-spin edge channels along the physical graphene edge can be used to form beamsplitters, whereas the absence of interchannel scattering along gate-defined interfaces can be used to form isolated interferometer arms. Surprisingly, our interferometer is robust to dephasing effects at energies an order of magnitude larger than those observed in pioneering experiments on GaAs/AlGaAs quantum wells. Our results shed light on the nature of edge-channel equilibration and open up new possibilities for studying exotic electron statistics and quantum phenomena.

  8. Detection of biochemical reactions by a surface plasmon resonance senor based on polarization interferometry and angle modulation

    Science.gov (United States)

    Hu, Zhaoxu; Chong, Xinyuan; Ma, Suihua; Li, Yao; He, Yonghong; Guo, Jihua

    2009-08-01

    A surface plasmon resonance (SPR) bio-sensing system has been developed. The system is based on polarization interferometry and angel modulation. In this paper, we apply it in the biological detection. We use the DNA fragment of Escherichia coli (Bacterial 16S rDNA universal primer) as bioprobe and . The process that analyte attach with the bioprobe, and coli DNA as analyte, get a resolution about 2.7× 10-6RI and 0.18nM/L in coli DNA detection.

  9. Theory and Applications of Surface Plasmon Resonance, Resonant Mirror, Resonant Waveguide Grating, and Dual Polarization Interferometry Biosensors

    Directory of Open Access Journals (Sweden)

    Billy W. Day

    2010-11-01

    Full Text Available Biosensors have been used extensively in the scientific community for several purposes, most notably to determine association and dissociation kinetics, protein-ligand, protein-protein, or nucleic acid hybridization interactions. A number of different types of biosensors are available in the field, each with real or perceived benefits over the others. This review discusses the basic theory and operational arrangements of four commercially available types of optical biosensors: surface plasmon resonance, resonant mirror, resonance waveguide grating, and dual polarization interferometry. The different applications these techniques offer are discussed from experiments and results reported in recently published literature. Additionally, recent advancements or modifications to the current techniques are also discussed.

  10. On the use of polarization modulation in combined interferometry and polarimetry. Corrigendum. 1998 Plasma Phys. Control. Fusion, v. 40 p. 153-161

    International Nuclear Information System (INIS)

    Segre, S.E.

    1998-01-01

    Errors in the main text, the appendix and two curves are corrected in this corrigendum to the paper entitled ''On the use of polarization modulation in combined interferometry and polarimetry'', written by S.E. Segre and published in 1998 Plasma Phys. Control. Fusion, v. 40 p. 153-161

  11. Measuring polarization dependent dispersion of non-polarizing beam splitter cubes with spectrally resolved white light interferometry

    Science.gov (United States)

    Csonti, K.; Hanyecz, V.; Mészáros, G.; Kovács, A. P.

    2017-06-01

    In this work we have measured the group-delay dispersion of an empty Michelson interferometer for s- and p-polarized light beams applying two different non-polarizing beam splitter cubes. The interference pattern appearing at the output of the interferometer was resolved with two different spectrometers. It was found that the group-delay dispersion of the empty interferometer depended on the polarization directions in case of both beam splitter cubes. The results were checked by inserting a glass plate in the sample arm of the interferometer and similar difference was obtained for the two polarization directions. These results show that to reach high precision, linearly polarized white light beam should be used and the residual dispersion of the empty interferometer should be measured at both polarization directions.

  12. A polarized digital shearing speckle pattern interferometry system based on temporal wavelet transformation.

    Science.gov (United States)

    Feng, Ziang; Gao, Zhan; Zhang, Xiaoqiong; Wang, Shengjia; Yang, Dong; Yuan, Hao; Qin, Jie

    2015-09-01

    Digital shearing speckle pattern interferometry (DSSPI) has been recognized as a practical tool in testing strain. The DSSPI system which is based on temporal analysis is attractive because of its ability to measure strain dynamically. In this paper, such a DSSPI system with Wollaston prism has been built. The principles and system arrangement are described and the preliminary experimental result of the displacement-derivative test of an aluminum plate is shown with the wavelet transformation method and the Fourier transformation method. The simulations have been conducted with the finite element method. The comparison of the results shows that quantitative measurement of displacement-derivative has been realized.

  13. Evaluation of polarization mode dispersion in a telecommunication wavelength selective switch using quantum interferometry.

    Science.gov (United States)

    Fraine, A; Minaeva, O; Simon, D S; Egorov, R; Sergienko, A V

    2012-01-30

    A polarization mode dispersion (PMD) measurement of a commercial telecommunication wavelength selective switch (WSS) using a quantum interferometric technique with polarization-entangled states is presented. Polarization-entangled photons with a broad spectral width covering the telecom band are produced using a chirped periodically poled nonlinear crystal. The first demonstration of a quantum metrology application using an industrial commercial device shows a promising future for practical high-resolution quantum interference.

  14. Effect of grafted PEG chain conformation on albumin and lysozyme adsorption: A combined study using QCM-D and DPI.

    Science.gov (United States)

    Jin, Jing; Han, Yuanyuan; Zhang, Chang; Liu, Jingchuan; Jiang, Wei; Yin, Jinghua; Liang, Haojun

    2015-12-01

    In this study, elucidation of protein adsorption mechanism is performed using dual polarization interferometry (DPI) and quartz crystal microbalance with dissipation (QCM-D) to study adsorption behaviors of bovine serum albumin (BSA) and lysozyme (LYZ) on poly (ethylene glycol) (PEG) layers. From the analysis of DPI, PEG2000 and PEG5000 show tight and loose mushroom conformations, respectively. Small amount of LYZ could displace the interfacial water surrounding the tight mushroomed PEG2000 chains by hydrogen bond attraction, leading to protein adsorption. The loose mushroomed PEG5000 chains exhibit a more flexible conformation and high elastic repulsion energy that could prevent protein adsorption of all BSA and most of LYZ. From the analysis of QCM, PEG2000 and PEG5000 show tight and extended brush conformations. The LYZ adsorbed mass has critical regions of PEG2000 (0.19 chain/nm(2)) and PEG5000 (0.16 chain/nm(2)) graft density. When graft density of PEG is higher than the critical region (brush conformations), the attraction of hydrogen bonds between PEG and LYZ is the dominant factor. When graft density of PEG is lower than the critical region (mushroom conformations), elastic repulsion between PEG and proteins is driven by the high conformation entropy of PEG chains, which is the dominant force of steric repulsion in PEG-protein systems. Therefore, the adsorption of BSA is suppressed by the high elastic repulsion energy of PEG chains, whereas the adsorption of LYZ is balanced by the interactions between the repulsion of entropy elasticity and the attraction of hydrogen bonds. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Analysis list: dpy-27 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available dpy-27 Adult,Embryo,Larvae + ce10 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/t...arget/dpy-27.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/dpy-27.5.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/ce10/target/dpy-27.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/dpy-27....Adult.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/dpy-27.Embryo.tsv,http://dbarchive.bioscien...cedbc.jp/kyushu-u/ce10/colo/dpy-27.Larvae.tsv http://dbarchive.biosciencedbc.jp/kyu

  16. Radar Interferometry Studies of the Mass Balance of Polar Ice Sheets

    Science.gov (United States)

    Rignot, Eric (Editor)

    1999-01-01

    The objectives of this work are to determine the current state of mass balance of the Greenland and Antarctic Ice Sheets. Our approach combines different techniques, which include satellite synthetic-aperture radar interferometry (InSAR), radar and laser altimetry, radar ice sounding, and finite-element modeling. In Greenland, we found that 3.5 times more ice flows out of the northern part of the Greenland Ice Sheet than previously accounted for. The discrepancy between current and past estimates is explained by extensive basal melting of the glacier floating sections in the proximity of the grounding line where the glacier detaches from its bed and becomes afloat in the ocean. The inferred basal melt rates are very large, which means that the glaciers are very sensitive to changes in ocean conditions. Currently, it appears that the northern Greenland glaciers discharge more ice than is being accumulated in the deep interior, and hence are thinning. Studies of temporal changes in grounding line position using InSAR confirm the state of retreat of northern glaciers and suggest that thinning is concentrated at the lower elevations. Ongoing work along the coast of East Greenland reveals an even larger mass deficit for eastern Greenland glaciers, with thinning affecting the deep interior of the ice sheet. In Antarctica, we found that glaciers flowing into a large ice shelf system, such as the Ronne Ice Shelf in the Weddell Sea, exhibit an ice discharge in remarkable agreement with mass accumulation in the interior, and the glacier grounding line positions do not migrate with time. Glaciers flowing rapidly into the Amudsen Sea, unrestrained by a major ice shelf, are in contrast discharging more ice than required to maintain a state of mass balance and are thinning quite rapidly near the coast. The grounding line of Pine Island glacier (see diagram) retreated 5 km in 4 years, which corresponds to a glacier thinning rate of 3.5 m/yr. Mass imbalance is even more negative

  17. Independent Comparison of Popular DPI Tools for Traffic Classification

    DEFF Research Database (Denmark)

    Bujlow, Tomasz; Carela-Español, Valentín; Barlet-Ros, Pere

    2015-01-01

    Deep Packet Inspection (DPI) is the state-of-the-art technology for traffic classification. According to the conventional wisdom, DPI is the most accurate classification technique. Consequently, most popular products, either commercial or open-source, rely on some sort of DPI for traffic classifi......Deep Packet Inspection (DPI) is the state-of-the-art technology for traffic classification. According to the conventional wisdom, DPI is the most accurate classification technique. Consequently, most popular products, either commercial or open-source, rely on some sort of DPI for traffic......, application and web service). We carefully built a labeled dataset with more than 750K flows, which contains traffic from popular applications. We used the Volunteer-Based System (VBS), developed at Aalborg University, to guarantee the correct labeling of the dataset. We released this dataset, including full...

  18. A Recurrent Deletion of DPY19L2 Causes Infertility in Man by Blocking Sperm Head Elongation and Acrosome Formation

    Science.gov (United States)

    Harbuz, Radu; Zouari, Raoudha; Pierre, Virginie; Ben Khelifa, Mariem; Kharouf, Mahmoud; Coutton, Charles; Merdassi, Ghaya; Abada, Farid; Escoffier, Jessica; Nikas, Yorgos; Vialard, François; Koscinski, Isabelle; Triki, Chema; Sermondade, Nathalie; Schweitzer, Thérèse; Zhioua, Amel; Zhioua, Fethi; Latrous, Habib; Halouani, Lazhar; Ouafi, Marrakchi; Makni, Mounir; Jouk, Pierre-Simon; Sèle, Bernard; Hennebicq, Sylviane; Satre, Véronique; Viville, Stéphane; Arnoult, Christophe; Lunardi, Joël; Ray, Pierre F.

    2011-01-01

    An increasing number of couples require medical assistance to achieve a pregnancy, and more than 2% of the births in Western countries now result from assisted reproductive technologies. To identify genetic variants responsible for male infertility, we performed a whole-genome SNP scan on patients presenting with total globozoospermia, a primary infertility phenotype characterized by the presence of 100% round acrosomeless spermatozoa in the ejaculate. This strategy allowed us to identify in most patients (15/20) a 200 kb homozygous deletion encompassing only DPY19L2, which is highly expressed in the testis. Although there was no known function for DPY19L2 in humans, previous work indicated that its ortholog in C. elegans is involved in cell polarity. In man, the DPY19L2 region has been described as a copy-number variant (CNV) found to be duplicated and heterozygously deleted in healthy individuals. We show here that the breakpoints of the deletions are located on a highly homologous 28 kb low copy repeat (LCR) sequence present on each side of DPY19L2, indicating that the identified deletions were probably produced by nonallelic homologous recombination (NAHR) between these two regions. We demonstrate that patients with globozoospermia have a homozygous deletion of DPY19L2, thus indicating that DPY19L2 is necessary in men for sperm head elongation and acrosome formation. A molecular diagnosis can now be proposed to affected men; the presence of the deletion confirms the diagnosis of globozoospermia and assigns a poor prognosis for the success of in vitro fertilization. PMID:21397064

  19. Study of $D_J$ meson decays to $D^+\\pi^-$, $D^0 \\pi^+$ and $D^{*+}\\pi^-$ final states in $pp$ collisions

    CERN Document Server

    INSPIRE-00258707; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicheur, A; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; Mc Skelly, B; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mordà, A; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neubert, S; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Roberts, D A; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Salzmann, C; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Sirendi, M; Skwarnicki, T; Smith, N A; Smith, E; Smith, J; Smith, M; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Sun, L; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Ustyuzhanin, A; Uwer, U; Vagnoni, V; Valenti, G; Vallier, A; Van Dijk, M; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, C; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wimberley, J; Wishahi, J; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

    2013-01-01

    A study of $D^+\\pi^-$, $D^0 \\pi^+$ and $D^{*+}\\pi^-$ final states is performed using pp collision data, corresponding to an integrated luminosity of 1.0 $fb^{-1}$, collected at a centre-of-mass energy of 7 TeV with the LHCb detector. The $D_1(2420)^0$ resonance is observed in the $D^{*+}\\pi^-$ final state and the $D^*_2(2460)$ resonance is observed in the $D^+\\pi^-$, $D^0 \\pi^+$ and $D^{*+}\\pi^-$ final states. For both resonances, their properties and spin-parity assignments are obtained. In addition, two natural parity and two unnatural parity resonances are observed in the mass region between 2500 and 2800 MeV. Further structures in the region around 3000 MeV are observed in all the $D^{*+}\\pi^-$, $D^+\\pi^-$ and $D^0 \\pi^+$ final states.

  20. Real-Time Study of the Interaction between G-Rich DNA Oligonucleotides and Lead Ion on DNA Tetrahedron-Functionalized Sensing Platform by Dual Polarization Interferometry.

    Science.gov (United States)

    Wang, Shuang; Lu, Shasha; Zhao, Jiahui; Huang, Jianshe; Yang, Xiurong

    2017-11-29

    G-quadruplex plays roles in numerous physiological and pathological processes of organisms. Due to the unique properties of G-quadruplex (e.g., forming G4/hemin complexes with catalytic activity and electron acceptability, binding with metal ions, proteins, fluorescent ligands, and so on), it has been widely applied in biosensing. But the formation process of G-quadruplex is not yet fully understood. Here, a DNA tetrahedron platform with higher reproducibility, regenerative ability, and time-saving building process was coupled with dual polarization interferometry technique for the real-time and label-free investigation of the specific interaction process of guanine-rich singled-stranded DNA (G-rich ssDNA) and Pb 2+ . The oriented immobilization of probes greatly decreased the spatial hindrance effect and improved the accessibility of the probes to the Pb 2+ ions. Through real-time monitoring of the whole formation process of the G-quadruplex, we speculated that the probes on the tetrahedron platform initially stood on the sensing surface with a random coil conformation, then the G-rich ssDNA preliminarily formed unstable G-quartets by H-bonding and cation binding, subsequently forming a completely folded and stable quadruplex structure through relatively slow strand rearrangements. On the basis of these studies, we also developed a novel sensing platform for the specific and sensitive determination of Pb 2+ and its chelating agent ethylenediaminetetraacetic acid. This study not only provides a proof-of-concept for conformational dynamics of G-quadruplex-related drugs and pathogenes, but also enriches the biosensor tools by combining nanomaterial with interfaces technique.

  1. Simultaneous Immersion Mirau Interferometry

    Science.gov (United States)

    Lyulko, Oleksandra

    acquisition challenging. This problem was resolved by integration of polarization optics into the optics of the attachment to enable simultaneous creation and spatial separation of two interferograms, which, combined with the background image, are used to reconstruct the intensity map of the specimen. Giving the name Simultaneous Immersion Mirau Interferometry to this approach, simultaneous acquisition of all interferograms per image has eliminated the issue of vibrations. The designed compound microscope attachment has been manufactured and tested; the system produces images of quality, sufficient to perform targeted cellular irradiation experiments.

  2. Speckle interferometry

    Science.gov (United States)

    Sirohi, Rajpal S.

    2002-03-01

    Illumination of a rough surface by a coherent monochromatic wave creates a grainy structure in space termed a speckle pattern. It was considered a special kind of noise and was the bane of holographers. However, its information-carrying property was soon discovered and the phenomenon was used for metrological applications. The realization that a speckle pattern carried information led to a new measurement technique known as speckle interferometry (SI). Although the speckle phenomenon in itself is a consequence of interference among numerous randomly dephased waves, a reference wave is required in SI. Further, it employs an imaging geometry. Initially SI was performed mostly by using silver emulsions as the recording media. The double-exposure specklegram was filtered to extract the desired information. Since SI can be configured so as to be sensitive to the in-plane displacement component, the out-of-plane displacement component or their derivatives, the interferograms corresponding to these were extracted from the specklegram for further analysis. Since the speckle size can be controlled by the F number of the imaging lens, it was soon realized that SI could be performed with electronic detection, thereby increasing its accuracy and speed of measurement. Furthermore, a phase-shifting technique can also be incorporated. This technique came to be known as electronic speckle pattern interferometry (ESPI). It employed the same experimental configurations as SI. ESPI found many industrial applications as it supplements holographic interferometry. We present three examples covering diverse areas. In one application it has been used to measure residual stress in a blank recordable compact disk. In another application, microscopic ESPI has been used to study the influence of relative humidity on paint-coated figurines and also the effect of a conservation agent applied on top of this. The final application is to find the defects in pipes. These diverse applications

  3. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei

    2013-01-01

    This monograph is devoted to the creation of a comprehensive formalism for quantitative description of polarized modes' linear interaction in modern single-mode optic fibers. The theory of random connections between polarized modes, developed in the monograph, allows calculations of the zero shift deviations for a fiber ring interferometer. The monograph addresses also the

  4. Speckle Interferometry

    Science.gov (United States)

    Chiang, F. P.; Jin, F.; Wang, Q.; Zhu, N.

    Before the milestone work of Leedertz in 1970 coherent speckles generated from a laser illuminated object are considered noise to be eliminated or minimized. Leedertz shows that coherent speckles are actually information carriers. Since then the speckle technique has found many applications to fields of mechanics, metrology, nondestructive evaluation and material sciences. Speckles need not be coherent. Artificially created socalled white light speckles can also be used as information carriers. In this paper we present two recent developments of speckle technique with applications to micromechanics problems using SIEM (Speckle Interferometry with Electron Microscopy), to nondestructive evaluation of crevice corrosion and composite disbond and vibration of large structures using TADS (Time-Average Digital Specklegraphy).

  5. Molecular basis for DPY-30 association to COMPASS-like and NURF complexes.

    Science.gov (United States)

    Tremblay, Véronique; Zhang, Pamela; Chaturvedi, Chandra-Prakash; Thornton, Janet; Brunzelle, Joseph S; Skiniotis, Georgios; Shilatifard, Ali; Brand, Marjorie; Couture, Jean-François

    2014-12-02

    DPY-30 is a subunit of mammalian COMPASS-like complexes (complex of proteins associated with Set1) and regulates global histone H3 Lys-4 trimethylation. Here we report structural evidence showing that the incorporation of DPY-30 into COMPASS-like complexes is mediated by several hydrophobic interactions between an amphipathic α helix located on the C terminus of COMPASS subunit ASH2L and the inner surface of the DPY-30 dimerization/docking (D/D) module. Mutations impairing the interaction between ASH2L and DPY-30 result in a loss of histone H3K4me3 at the β locus control region and cause a delay in erythroid cell terminal differentiation. Using overlay assays, we defined a consensus sequence for DPY-30 binding proteins and found that DPY-30 interacts with BAP18, a subunit of the nucleosome remodeling factor complex. Overall, our results indicate that the ASH2L/DPY-30 complex is important for cell differentiation and provide insights into the ability of DPY-30 to associate with functionally divergent multisubunit complexes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Quantum Interferometry

    Science.gov (United States)

    Dowling, Jonathan P.

    2000-01-01

    Recently, several researchers, including yours truly, have been able to demonstrate theoretically that quantum photon entanglement has the potential to also revolutionize the entire field of optical interferometry, by providing many orders of magnitude improvement in interferometer sensitivity. The quantum entangled photon interferometer approach is very general and applies to many types of interferometers. In particular, without nonlocal entanglement, a generic classical interferometer has a statistical-sampling shot-noise limited sensitivity that scales like 1/Sqrt[N], where N is the number of particles (photons, electrons, atoms, neutrons) passing through the interferometer per unit time. However, if carefully prepared quantum correlations are engineered between the particles, then the interferometer sensitivity improves by a factor of Sqrt[N] (square root of N) to scale like 1/N, which is the limit imposed by the Heisenberg Uncertainty Principle. For optical (laser) interferometers operating at milliwatts of optical power, this quantum sensitivity boost corresponds to an eight-order-of-magnitude improvement of signal to noise. Applications are to tests of General Relativity such as ground and orbiting optical interferometers for gravity wave detection, Laser Interferometer Gravity Observatory (LIGO) and the European Laser Interferometer Space Antenna (LISA), respectively.

  7. Identification of a new DPY19L2 mutation and a better definition of DPY19L2 deletion breakpoints leading to globozoospermia.

    Science.gov (United States)

    Ghédir, Houda; Ibala-Romdhane, Samira; Okutman, Ozlem; Viot, Géraldine; Saad, Ali; Viville, Stéphane

    2016-01-01

    The purpose of this study was to analyze DPY19L2 sequence variants to investigate the mechanism leading to the entire DPY19L2 deletion in a large cohort of infertile globozoospermic patients. An improved analysis of the DPY19L2 deletion breakpoints (BPs) allowed us to identify two BPs located in a small 1 kb region and to more precisely localize the BPs reported previously. Three genes [spermatogenesis associated 16 (SPATA16), protein interacting with PRKCA (PICK1) and DPY19L2] were previously correlated with globozoospermia, but a homozygous deletion of the entire DPY19L2 was identified as the most frequent alteration causing this phenotype. In addition, several point mutations in this gene were reported. In previous work, we have identified nine BPs for the DPY19L2 deletion clustered in two hotspot regions, while others reported a total of five BPs. We screened for the DPY19L2 deletion and for mutations in the DPY19L2, SPATA16 and PICK1 genes in a cohort of 21 Tunisian globozoospermic patients. In order to characterize the DPY19L2 deletion BPs, we sequenced a 2 kb fragment on low copy repeat (LCR) 1 and LCR2 in Tunisian fertile controls to distinguish between single-nucleotide polymorphisms (SNPs) and LCR-specific markers. Molecular analyses performed on 18 genetically independent individuals showed that 11 (61.1%) were homozygous for the DPY19L2 deletion, 2 (11.1%) were homozygous for the non-synonymous mutation (p.R298C) in exon 8, 1 patient (5.6%) was homozygous for a new splice-site mutation at the junction exon-intron 16 [c.1579_1580+4delAGGTAAinsTCAT] and no DPY19L2, SPATA16 or PICK1 mutations were identified for 4 patients (22.2%). By defining 15 specific LCR markers, we characterized 2 BPs for the DPY19L2 deletion in 11 patients showing the homozygous deletion. Using 20 non-LCR-specific SNPs, we identified 8 distinct haplotypes. A limitation of this study is the small number of patients owing to the rarity of this form of male infertility. Our data showed

  8. Dpy30 is critical for maintaining the identity and function of adult hematopoietic stem cells

    Science.gov (United States)

    2016-01-01

    As the major histone H3K4 methyltransferases in mammals, the Set1/Mll complexes play important roles in animal development and are associated with many diseases, including hematological malignancies. However, the role of the H3K4 methylation activity of these complexes in fate determination of hematopoietic stem and progenitor cells (HSCs and HPCs) remains elusive. Here, we address this question by generating a conditional knockout mouse for Dpy30, which is a common core subunit of all Set1/Mll complexes and facilitates genome-wide H3K4 methylation in cells. Dpy30 loss in the adult hematopoietic system results in severe pancytopenia but striking accumulation of HSCs and early HPCs that are defective in multilineage reconstitution, suggesting a differentiation block. In mixed bone marrow chimeras, Dpy30-deficient HSCs cannot differentiate or efficiently up-regulate lineage-regulatory genes, and eventually fail to sustain for long term with significant loss of HSC signature gene expression. Our molecular analyses reveal that Dpy30 directly and preferentially controls H3K4 methylation and expression of many hematopoietic development-associated genes including several key transcriptional and chromatin regulators involved in HSC function. Collectively, our results establish a critical and selective role of Dpy30 and the H3K4 methylation activity of the Set1/Mll complexes for maintaining the identity and function of adult HSCs. PMID:27647347

  9. Dpy30 is critical for maintaining the identity and function of adult hematopoietic stem cells.

    Science.gov (United States)

    Yang, Zhenhua; Shah, Kushani; Khodadadi-Jamayran, Alireza; Jiang, Hao

    2016-10-17

    As the major histone H3K4 methyltransferases in mammals, the Set1/Mll complexes play important roles in animal development and are associated with many diseases, including hematological malignancies. However, the role of the H3K4 methylation activity of these complexes in fate determination of hematopoietic stem and progenitor cells (HSCs and HPCs) remains elusive. Here, we address this question by generating a conditional knockout mouse for Dpy30, which is a common core subunit of all Set1/Mll complexes and facilitates genome-wide H3K4 methylation in cells. Dpy30 loss in the adult hematopoietic system results in severe pancytopenia but striking accumulation of HSCs and early HPCs that are defective in multilineage reconstitution, suggesting a differentiation block. In mixed bone marrow chimeras, Dpy30-deficient HSCs cannot differentiate or efficiently up-regulate lineage-regulatory genes, and eventually fail to sustain for long term with significant loss of HSC signature gene expression. Our molecular analyses reveal that Dpy30 directly and preferentially controls H3K4 methylation and expression of many hematopoietic development-associated genes including several key transcriptional and chromatin regulators involved in HSC function. Collectively, our results establish a critical and selective role of Dpy30 and the H3K4 methylation activity of the Set1/Mll complexes for maintaining the identity and function of adult HSCs. © 2016 Yang et al.

  10. Duplication and relocation of the functional DPY19L2 gene within low copy repeats

    Directory of Open Access Journals (Sweden)

    Cheung Joseph

    2006-03-01

    Full Text Available Abstract Background Low copy repeats (LCRs are thought to play an important role in recent gene evolution, especially when they facilitate gene duplications. Duplicate genes are fundamental to adaptive evolution, providing substrates for the development of new or shared gene functions. Moreover, silencing of duplicate genes can have an indirect effect on adaptive evolution by causing genomic relocation of functional genes. These changes are theorized to have been a major factor in speciation. Results Here we present a novel example showing functional gene relocation within a LCR. We characterize the genomic structure and gene content of eight related LCRs on human Chromosomes 7 and 12. Two members of a novel transmembrane gene family, DPY19L, were identified in these regions, along with six transcribed pseudogenes. One of these genes, DPY19L2, is found on Chromosome 12 and is not syntenic with its mouse orthologue. Instead, the human locus syntenic to mouse Dpy19l2 contains a pseudogene, DPY19L2P1. This indicates that the ancestral copy of this gene has been silenced, while the descendant copy has remained active. Thus, the functional copy of this gene has been relocated to a new genomic locus. We then describe the expansion and evolution of the DPY19L gene family from a single gene found in invertebrate animals. Ancient duplications have led to multiple homologues in different lineages, with three in fish, frogs and birds and four in mammals. Conclusion Our results show that the DPY19L family has expanded throughout the vertebrate lineage and has undergone recent primate-specific evolution within LCRs.

  11. Principles of Stellar Interferometry

    CERN Document Server

    Glindemann, Andreas

    2011-01-01

    Over the last decade, stellar interferometry has developed from a specialist tool to a mainstream observing technique, attracting scientists whose research benefits from milliarcsecond angular resolution. Stellar interferometry has become part of the astronomer’s toolbox, complementing single-telescope observations by providing unique capabilities that will advance astronomical research. This carefully written book is intended to provide a solid understanding of the principles of stellar interferometry to students starting an astronomical research project in this field or to develop instruments and to astronomers using interferometry but who are not interferometrists per se. Illustrated by excellent drawings and calculated graphs the imaging process in stellar interferometers is explained starting from first principles on light propagation and diffraction wave propagation through turbulence is described in detail using Kolmogorov statistics the impact of turbulence on the imaging process is discussed both f...

  12. LISA Long-Arm Interferometry

    Science.gov (United States)

    Thorpe, James I.

    2009-01-01

    An overview of LISA Long-Arm Interferometry is presented. The contents include: 1) LISA Interferometry; 2) Constellation Design; 3) Telescope Design; 4) Constellation Acquisition; 5) Mechanisms; 6) Optical Bench Design; 7) Phase Measurement Subsystem; 8) Phasemeter Demonstration; 9) Time Delay Interferometry; 10) TDI Limitations; 11) Active Frequency Stabilization; 12) Spacecraft Level Stabilization; 13) Arm-Locking; and 14) Embarassment of Riches.

  13. Validating Whole-Airway CFD Predictions of DPI Aerosol Deposition at Multiple Flow Rates.

    Science.gov (United States)

    Longest, P Worth; Tian, Geng; Khajeh-Hosseini-Dalasm, Navvab; Hindle, Michael

    2016-12-01

    The objective of this study was to compare aerosol deposition predictions of a new whole-airway CFD model with available in vivo data for a dry powder inhaler (DPI) considered across multiple inhalation waveforms, which affect both the particle size distribution (PSD) and particle deposition. The Novolizer DPI with a budesonide formulation was selected based on the availability of 2D gamma scintigraphy data in humans for three different well-defined inhalation waveforms. Initial in vitro cascade impaction experiments were conducted at multiple constant (square-wave) particle sizing flow rates to characterize PSDs. The whole-airway CFD modeling approach implemented the experimentally determined PSDs at the point of aerosol formation in the inhaler. Complete characteristic airway geometries for an adult were evaluated through the lobar bronchi, followed by stochastic individual pathway (SIP) approximations through the tracheobronchial region and new acinar moving wall models of the alveolar region. It was determined that the PSD used for each inhalation waveform should be based on a constant particle sizing flow rate equal to the average of the inhalation waveform's peak inspiratory flow rate (PIFR) and mean flow rate [i.e., AVG(PIFR, Mean)]. Using this technique, agreement with the in vivo data was acceptable with <15% relative differences averaged across the three regions considered for all inhalation waveforms. Defining a peripheral to central deposition ratio (P/C) based on alveolar and tracheobronchial compartments, respectively, large flow-rate-dependent differences were observed, which were not evident in the original 2D in vivo data. The agreement between the CFD predictions and in vivo data was dependent on accurate initial estimates of the PSD, emphasizing the need for a combination in vitro-in silico approach. Furthermore, use of the AVG(PIFR, Mean) value was identified as a potentially useful method for characterizing a DPI aerosol at a constant flow rate.

  14. Application of interferometry to studies of glacier dynamics

    DEFF Research Database (Denmark)

    Mohr, Johan Jacob

    1996-01-01

    Multi baseline repeat track interferometry (RTI) can potentially be used to measure both velocities and the micro topography of glaciers. The Danish Center for Remote Sensing (DCRS) in corporation with the Danish Polar Center (DPC) has established a test cite for studies of glacier dynamics on th...

  15. Iterative supervirtual refraction interferometry

    KAUST Repository

    Al-Hagan, Ola

    2014-05-02

    In refraction tomography, the low signal-to-noise ratio (S/N) can be a major obstacle in picking the first-break arrivals at the far-offset receivers. To increase the S/N, we evaluated iterative supervirtual refraction interferometry (ISVI), which is an extension of the supervirtual refraction interferometry method. In this method, supervirtual traces are computed and then iteratively reused to generate supervirtual traces with a higher S/N. Our empirical results with both synthetic and field data revealed that ISVI can significantly boost up the S/N of far-offset traces. The drawback is that using refraction events from more than one refractor can introduce unacceptable artifacts into the final traveltime versus offset curve. This problem can be avoided by careful windowing of refraction events.

  16. Parsimonious Surface Wave Interferometry

    KAUST Repository

    Li, Jing

    2017-10-24

    To decrease the recording time of a 2D seismic survey from a few days to one hour or less, we present a parsimonious surface-wave interferometry method. Interferometry allows for the creation of a large number of virtual shot gathers from just two reciprocal shot gathers by crosscoherence of trace pairs, where the virtual surface waves can be inverted for the S-wave velocity model by wave-equation dispersion inversion (WD). Synthetic and field data tests suggest that parsimonious wave-equation dispersion inversion (PWD) gives S-velocity tomograms that are comparable to those obtained from a full survey with a shot at each receiver. The limitation of PWD is that the virtual data lose some information so that the resolution of the S-velocity tomogram can be modestly lower than that of the S-velocity tomogram inverted from a conventional survey.

  17. Scope of neutron interferometry

    International Nuclear Information System (INIS)

    Rauch, H.

    1978-01-01

    This paper deals with the interferometry of well separated coherent beams, where the phase of the beams can be manipulated individually. The basic equation of the dynamical neutron diffraction theory are recalled. The various contributions to the interaction of as low neutron with its surroundings are discussed: the various terms denote the nuclear, magnetic, electromagnetic, intrinsic, gravitational, and weak interaction respectively. Applications to nuclear physics, fundamental physics and solid state physics are successively envisaged

  18. Coal fire interferometry

    International Nuclear Information System (INIS)

    Van Genderen, J.L.; Prakash, A.; Gens, R.; Van Veen, B.; Liding, Chen; Tao, Tang Xiao; Feng, Guan

    2000-07-01

    This BCRS project demonstrates the use of SAR interferometry for measuring and monitoring land subsidence caused by underground coal fires and underground mining in a remote area of north west China. China is the largest producer and consumer of coal in the world. Throughout the N.W., N. and N.E. of China, the coal-seams are very susceptible to spontaneous combustion, causing underground coal fires. As the thick coal seams are burned out, the overburden collapses, causing land subsidence, and producing new cracks and fissures, which allow more air to penetrate and continue the fire to spread. SAR interferometry, especially differential interferometry has been shown to be able to measure small differences in surface height caused by such land subsidence. This report describes the problems, the test area, the procedures and techniques used and the results obtained. It concludes with a description of some of the problems encountered during the project plus provides some general conclusions and recommendations. 127 refs

  19. DERECHOS DE PROPIEDAD INTELECTUAL (DPI) Y CRECIMIENTO ECONÓMICO: UNA REVISIÓN

    OpenAIRE

    RICARDO ALONSO TEJEDOR ESTUPIÑÁN; JOSÉ MAURICIO GIL LEÓN; JOAN MIGUEL TEJEDOR ESTUPIÑÁN

    2018-01-01

    Este artículo analiza los efectos de los Derechos de Propiedad Intelectual (DPI) sobre el crecimiento económico de los países, donde una mayor protección incentiva procesos de innovación que inci- den sobre el mayor avance de la producción. En el desarrollo analítico del trabajo se toma como marco teórico el modelo de crecimiento endógeno de Romer (1991), el cual explica los funda- mentos de cómo la formación de conocimiento conduce a que las economías eleven sus niveles de d...

  20. Spectral Interferometry with Electron Microscopes.

    Science.gov (United States)

    Talebi, Nahid

    2016-09-21

    Interference patterns are not only a defining characteristic of waves, but also have several applications; characterization of coherent processes and holography. Spatial holography with electron waves, has paved the way towards space-resolved characterization of magnetic domains and electrostatic potentials with angstrom spatial resolution. Another impetus in electron microscopy has been introduced by ultrafast electron microscopy which uses pulses of sub-picosecond durations for probing a laser induced excitation of the sample. However, attosecond temporal resolution has not yet been reported, merely due to the statistical distribution of arrival times of electrons at the sample, with respect to the laser time reference. This is however, the very time resolution which will be needed for performing time-frequency analysis. These difficulties are addressed here by proposing a new methodology to improve the synchronization between electron and optical excitations through introducing an efficient electron-driven photon source. We use focused transition radiation of the electron as a pump for the sample. Due to the nature of transition radiation, the process is coherent. This technique allows us to perform spectral interferometry with electron microscopes, with applications in retrieving the phase of electron-induced polarizations and reconstructing dynamics of the induced vector potential.

  1. Reverse effects of DPI administration combined with glutamine supplementation on function of rat neutrophils induced by overtraining.

    Science.gov (United States)

    Dong, Jingmei; Chen, Peijie; Liu, Qing; Wang, Ru; Xiao, Weihua; Zhang, Yajun

    2013-04-01

    To examine the excessive reactive oxygen species (ROS) mediated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and the combined effect of glutamine supplementation and diphenyleneiodonium (DPI) on the function of neutrophils induced by overtraining. Fifty male Wistar rats were randomly divided into 5 groups: control group (C), overtraining group (E), DPI-administration group (D), glutamine-supplementation group (G), and combined DPI and glutamine group (DG). Blood was sampled from the orbital vein after rats were trained on treadmill for 11 wk. Cytokine and lipid peroxidation in blood plasma were measured by enzyme-linked immunosorbent assay. The colocalization between gp91phox and p47phox of the NADPH oxidase was detected using immunocytochemistry and confocal microscopy. The activity of NADPH oxidase was assessed by chemiluminescence. Neutrophils' respiratory burst and phagocytosis function were measured by flow cytometry. NADPH oxidase was activated by overtraining. Cytokine and lipid peroxidation in blood plasma and the activity of NADPH oxidase were markedly increased in Group E compared with group C. Neutrophil function was lower in group E than group C. Both lower neutrophils function and higher ROS production were reversed in Group DG. The glutamine and DPI interference alone in group D and group G was less effective than DPI and glutamine combined in group DG. Activation of NADPH oxidase is responsible for the production of superoxide anions, which leads to excessive ROS and is related to the decrease in neutrophil function induced by overtraining. The combined DPI administration and glutamine supplementation reversed the decreased neutrophil function after overtraining.

  2. Antihydrogen Experiment Gravity Interferometry Spectroscopy

    CERN Multimedia

    Trezzi, D; Dassa, L; Rienacker, B; Khalidova, O; Ferrari, G; Krasnicky, D; Perini, D; Cerchiari, G; Belov, A; Boscolo, I; Sacerdoti, M G; Ferragut, R O; Nedelec, P; Hinterberger, A; Al-qaradawi, I; Malbrunot, C L S; Brusa, R S; Prelz, F; Manuzio, G; Riccardi, C; Fontana, A; Genova, P; Haider, S; Haug, F; Turbabin, A; Castelli, F; Testera, G; Lagomarsino, V E; Doser, M; Penasa, L; Gninenko, S; Cataneo, F; Zenoni, A; Cabaret, L; Comparat, D P; Zmeskal, J; Scampoli, P; Nesteruk, K P; Dudarev, A; Kellerbauer, A G; Mariazzi, S; Carraro, C; Zavatarelli, S M

    The AEGIS experiment (Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy) has the aim of carrying out the first measurement of the gravitational interaction of antimatter to a precision of 1%, by applying techniques from atomic physics, laser spectroscopy and interferometry to a beam of antihydrogen atoms. A further goal of the experiment is to carry out spectroscopy of the antihydrogen atoms in flight.

  3. Basics of interferometry

    CERN Document Server

    Hariharan, P

    1992-01-01

    This book is for those who have some knowledge of optics, but little or no previous experience in interferometry. Accordingly, the carefully designed presentation helps readers easily find and assimilate the interferometric techniques they need for precision measurements. Mathematics is held to a minimum, and the topics covered are also summarized in capsule overviews at the beginning and end of each chapter. Each chapter also contains a set of worked problems that give a feel for numbers.The first five chapters present a clear tutorial review of fundamentals. Chapters six and seven discus

  4. Na/sup +/ channels as sites of action of the cardioactive agent DPI 201-106 with agonist and antagonist enantiomers

    Energy Technology Data Exchange (ETDEWEB)

    Romey, G.; Quast, U.; Pauron, D.; Frelin, C.; Renaud, J.F.; Lazdunski, M.

    1987-02-01

    This paper shows the interaction of the cardiotonic agent 4-(3-(4-diphenylmethyl-1-piperazinyl)-2-hydroxypropoxy)-1H-indole-2-carbonitrile (DPI 201-106) and its optic enantiomers R-DPI (205-429) and S-DPI (205-430) with the Na/sup +/ channel of a variety of excitable cells. Voltage-clamp experiments show that DPI 201-106 acts on neuroblastoma cells and rat cardiac cells. S-DPI (205-430) increases the peak Na/sup +/ current, slows down the kinetics of Na/sup +/ channel inactivation, and is cardiotonic on heart cells. Conversely, R-DPI (205-429) reduces the peak Na/sup +/ current and blocks Na/sup +/ channel activity and cardiac contractions. Binding experiments using radioactively labeled toxins indicate that DPI 201-106 and its enantiomers do not interact with sites already identified for tetrodotoxin or sea anemone and scorpion toxins. DPI 201-106 and its enantiomers inhibit binding of a /sup 3/H-labeled batrachotoxin derivative, (/sup 3/H)batrachotoxinin A 20-..cap alpha..-benzoate, to brain membranes. The dissociation constant of the complex formed between the Na/sup +/ channel and both R-DPI and S-DPI is K/sub d/ approx. 100 nM. /sup 22/Na/sup +/ uptake experiments using different cell types have shown that R and S enantiomers of DPI 201-106 are active on the different Na/sup +/ channel subtypes with similar IC/sub 50/ values. These results are discussed in relation with the cardiotonic properties of DPI 201-106 that are not accompanied by cardiotoxic effects.

  5. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Massimo Tinto

    2014-08-01

    Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

  6. Complex master slave interferometry.

    Science.gov (United States)

    Rivet, Sylvain; Maria, Michael; Bradu, Adrian; Feuchter, Thomas; Leick, Lasse; Podoleanu, Adrian

    2016-02-08

    A general theoretical model is developed to improve the novel Spectral Domain Interferometry method denoted as Master/Slave (MS) Interferometry. In this model, two functions, g and h are introduced to describe the modulation chirp of the channeled spectrum signal due to nonlinearities in the decoding process from wavenumber to time and due to dispersion in the interferometer. The utilization of these two functions brings two major improvements to previous implementations of the MS method. A first improvement consists in reducing the number of channeled spectra necessary to be collected at Master stage. In previous MSI implementation, the number of channeled spectra at the Master stage equated the number of depths where information was selected from at the Slave stage. The paper demonstrates that two experimental channeled spectra only acquired at Master stage suffice to produce A-scans from any number of resolved depths at the Slave stage. A second improvement is the utilization of complex signal processing. Previous MSI implementations discarded the phase. Complex processing of the electrical signal determined by the channeled spectrum allows phase processing that opens several novel avenues. A first consequence of such signal processing is reduction in the random component of the phase without affecting the axial resolution. In previous MSI implementations, phase instabilities were reduced by an average over the wavenumber that led to reduction in the axial resolution.

  7. Fly-DPI: database of protein interactomes for D. melanogaster in the approach of systems biology

    Directory of Open Access Journals (Sweden)

    Lin Chieh-Hua

    2006-12-01

    Full Text Available Abstract Background Proteins control and mediate many biological activities of cells by interacting with other protein partners. This work presents a statistical model to predict protein interaction networks of Drosophila melanogaster based on insight into domain interactions. Results Three high-throughput yeast two-hybrid experiments and the collection in FlyBase were used as our starting datasets. The co-occurrences of domains in these interactive events are converted into a probability score of domain-domain interaction. These scores are used to infer putative interaction among all available open reading frames (ORFs of fruit fly. Additionally, the likelihood function is used to estimate all potential protein-protein interactions. All parameters are successfully iterated and MLE is obtained for each pair of domains. Additionally, the maximized likelihood reaches its converged criteria and maintains the probability stable. The hybrid model achieves a high specificity with a loss of sensitivity, suggesting that the model may possess major features of protein-protein interactions. Several putative interactions predicted by the proposed hybrid model are supported by literatures, while experimental data with a low probability score indicate an uncertain reliability and require further proof of interaction. Fly-DPI is the online database used to present this work. It is an integrated proteomics tool with comprehensive protein annotation information from major databases as well as an effective means of predicting protein-protein interactions. As a novel search strategy, the ping-pong search is a naïve path map between two chosen proteins based on pre-computed shortest paths. Adopting effective filtering strategies will facilitate researchers in depicting the bird's eye view of the network of interest. Fly-DPI can be accessed at http://flydpi.nhri.org.tw. Conclusion This work provides two reference systems, statistical and biological, to evaluate

  8. A New Direct-Pour In-Mold (DPI) Technology for Producing Ductile and Compacted Graphite Iron Castings.

    Energy Technology Data Exchange (ETDEWEB)

    Jason Hitchings; Jay R. Hitchings

    2007-07-20

    A new "Direct Pour In-Mold" (DPI) Magnesium treatment technology has been developed that can produce both Nodular and Compacted Graphite iron. The DPI technology converts the standard horizontal runner system into a vertical one, by placing a Magnesium Ferrosilicon treatment alloy and molten metal filter into a specially designed container. The DPI container is easily placed into either vertically or horizontally parted molds, and then a base metal can be poured directly into it. The metal is treated and filtered as it passes through, and then proceeds directly into a runner or casting cavity. Various sizes of containers provide all of the necessary components required to deliver a range of weights of treated and filtered metal at accurate and consistent flow rates. The DPI containers provide energy savings over competing techniques, increased mold yields, very high Magnesium recovery, zero Magnesium fume, and no post inoculation is required. By treating the metal just prior to it entering a casting cavity many other benefits and advantages are also realized.

  9. Systemic exposure to inhaled beclometasone/formoterol DPI is age and body size dependent

    DEFF Research Database (Denmark)

    Chawes, B L; Govoni, M; Kreiner-Møller, E

    2014-01-01

    AIM: Prescription of inhaled corticosteroids to children with asthma is recommended at half the nominal dose of adults in order to reduce the risk of systemic side effects. However, there is a lack of pharmacokinetic trials supporting such dose reduction regimens. Therefore, we aimed to compare t...... inversely with age and body size suggesting that dry powder dosage regimens should be adjusted for age and body size to avoid high systemic drug levels in children.......AIM: Prescription of inhaled corticosteroids to children with asthma is recommended at half the nominal dose of adults in order to reduce the risk of systemic side effects. However, there is a lack of pharmacokinetic trials supporting such dose reduction regimens. Therefore, we aimed to compare...... the systemic exposure to the active ingredients of a fixed dose combination of beclometasone-dipropionate (BDP) and formoterol after dry powder inhaler (DPI) administration in children, adolescents and adults. METHODS: The pharmacokinetic profiles of formoterol and beclometasone-17-monopropionate (B17MP...

  10. Parsimonious refraction interferometry

    KAUST Repository

    Hanafy, Sherif

    2016-09-06

    We present parsimonious refraction interferometry where a densely populated refraction data set can be obtained from just two shot gathers. The assumptions are that the first arrivals are comprised of head waves and direct waves, and a pair of reciprocal shot gathers is recorded over the line of interest. The refraction traveltimes from these reciprocal shot gathers can be picked and decomposed into O(N2) refraction traveltimes generated by N virtual sources, where N is the number of geophones in the 2D survey. This enormous increase in the number of virtual traveltime picks and associated rays, compared to the 2N traveltimes from the two reciprocal shot gathers, allows for increased model resolution and better condition numbers in the normal equations. Also, a reciprocal survey is far less time consuming than a standard refraction survey with a dense distribution of sources.

  11. High Annular Resolution Stellar Interferometry.

    Science.gov (United States)

    1985-07-31

    Double- Scar Interferometry and l:s Lessons Astrophys. and Space Sci. 11, 13-19 (1971) Finsen, W. S. Interferometer Observation of Binary Stars Astron. J...Interferometry Sky and Telescope 53, 346-350 (1977) McAlister, H. A. Speckle Interferometric Measurements of Binary Scars IV Astrophys. J. 230, 497-501...Ergebn. Exacten. Naturwiss. 10, 84-96 (1931) Pease, F.G. The Fifty-foot rnterferometer Telescope Armour Engineer, , 125-130 (1925) Perrier, C. An

  12. Phase referencing in optical interferometry

    OpenAIRE

    Filho, Mercedes E; Garcia, Paulo; Duvert, Gilles; Duchene, Gaspard; Thiebaut, Eric; Young, John; Absil, Olivier; Berger, Jean-Phillipe; Beckert, Thomas; Hoenig, Sebastian; Schertl, Dieter; Weigelt, Gerd; Testi, Leonardo; Tatuli, Eric; Borkowski, Virginie

    2008-01-01

    One of the aims of next generation optical interferometric instrumentation is to be able to make use of information contained in the visibility phase to construct high dynamic range images. Radio and optical interferometry are at the two extremes of phase corruption by the atmosphere. While in radio it is possible to obtain calibrated phases for the science objects, in the optical this is currently not possible. Instead, optical interferometry has relied on closure phase techniques to produce...

  13. Optical polarimetry for noninvasive glucose sensing enabled by Sagnac interferometry.

    Science.gov (United States)

    Winkler, Amy M; Bonnema, Garret T; Barton, Jennifer K

    2011-06-10

    Optical polarimetry is used in pharmaceutical drug testing and quality control for saccharide-containing products (juice, honey). More recently, it has been proposed as a method for noninvasive glucose sensing for diabetic patients. Sagnac interferometry is commonly used in optical gyroscopes, measuring minute Doppler shifts resulting from mechanical rotation. In this work, we demonstrate that Sagnac interferometers are also sensitive to optical rotation, or the rotation of linearly polarized light, and are therefore useful in optical polarimetry. Results from simulation and experiment show that Sagnac interferometers are advantageous in optical polarimetry as they are insensitive to net linear birefringence and alignment of polarization components.

  14. Extreme ultraviolet interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Kenneth A. [Univ. of California, Berkeley, CA (United States). Dept. of Physics

    1997-12-01

    EUV lithography is a promising and viable candidate for circuit fabrication with 0.1-micron critical dimension and smaller. In order to achieve diffraction-limited performance, all-reflective multilayer-coated lithographic imaging systems operating near 13-nm wavelength and 0.1 NA have system wavefront tolerances of 0.27 nm, or 0.02 waves RMS. Owing to the highly-sensitive resonant reflective properties of multilayer mirrors and extraordinarily tight tolerances set forth for their fabrication, EUV optical systems require at-wavelength EUV interferometry for final alignment and qualification. This dissertation discusses the development and successful implementation of high-accuracy EUV interferometric techniques. Proof-of-principle experiments with a prototype EUV point-diffraction interferometer for the measurement of Fresnel zoneplate lenses first demonstrated sub-wavelength EUV interferometric capability. These experiments spurred the development of the superior phase-shifting point-diffraction interferometer (PS/PDI), which has been implemented for the testing of an all-reflective lithographic-quality EUV optical system. Both systems rely on pinhole diffraction to produce spherical reference wavefronts in a common-path geometry. Extensive experiments demonstrate EUV wavefront-measuring precision beyond 0.02 waves RMS. EUV imaging experiments provide verification of the high-accuracy of the point-diffraction principle, and demonstrate the utility of the measurements in successfully predicting imaging performance. Complementary to the experimental research, several areas of theoretical investigation related to the novel PS/PDI system are presented. First-principles electromagnetic field simulations of pinhole diffraction are conducted to ascertain the upper limits of measurement accuracy and to guide selection of the pinhole diameter. Investigations of the relative merits of different PS/PDI configurations accompany a general study of the most significant sources

  15. Characterization of a New High-Dose Dry Powder Inhaler (DPI) Based on a Fluidized Bed Design

    Science.gov (United States)

    Farkas, Dale R.; Hindle, Michael; Longest, P. Worth

    2015-01-01

    The objective of this study was to develop a new high-efficiency dry powder inhaler (DPI) that can effectively aerosolize large masses (25–100 mg) of spray dried powder formulations. The DPI was designed to implement a concept similar to a fluidized bed for aerosolization using small mixing balls made of polytetrafluoroethylene (PTFE) along with a larger, hollow dosing sphere filled with the powder. The performance of the fluidized bed DPI was compared, based on emitted dose (ED) and aerosolization efficiency, to other recently developed capsule-based DPIs that were designed to accommodate smaller powder masses (~2–20 mg). The inhalers were tested with spray dried excipient enhanced growth formulations that contained an antibiotic (ciprofloxacin) and hygroscopic excipient (mannitol). The new fluidized bed design produced an ED of 71% along with a mass median aerodynamic diameter (MMAD) of 1.53 µm and fine particle fractions (FPFs) less than 5 µm and 1 µm of 93% and 36%, respectively, when used to deliver a 100 mg loaded mass of EEG powder with the advantage of not requiring multiple capsules. Surprisingly, performance of the device was further improved by removing the mixing balls from the inhaler and only retaining the dose containment sphere. PMID:25986955

  16. Characterization of a New High-Dose Dry Powder Inhaler (DPI) Based on a Fluidized Bed Design.

    Science.gov (United States)

    Farkas, Dale R; Hindle, Michael; Longest, P Worth

    2015-11-01

    The objective of this study was to develop a new high-efficiency dry powder inhaler (DPI) that can effectively aerosolize large masses (25-100 mg) of spray dried powder formulations. The DPI was designed to implement a concept similar to a fluidized bed for aerosolization using small mixing balls made of polytetrafluoroethylene along with a larger, hollow dosing sphere filled with the powder. The performance of the fluidized bed DPI was compared, based on emitted dose (ED) and aerosolization efficiency, to other recently developed capsule-based DPIs that were designed to accommodate smaller powder masses (~2-20 mg). The inhalers were tested with spray dried excipient enhanced growth (EEG) formulations that contained an antibiotic (ciprofloxacin) and hygroscopic excipient (mannitol). The new fluidized bed design produced an ED of 71% along with a mass median aerodynamic diameter of 1.53 μm and fine particle fractions <5 and 1 μm of 93 and 36%, respectively, when used to deliver a 100 mg loaded mass of EEG powder with the advantage of not requiring multiple capsules. Surprisingly, performance of the device was further improved by removing the mixing balls from the inhaler and only retaining the dose containment sphere.

  17. Shaken Lattice Interferometry

    Science.gov (United States)

    Weidner, Carrie; Yu, Hoon; Anderson, Dana

    2015-05-01

    This work introduces a method to perform interferometry using atoms trapped in an optical lattice. Starting at t = 0 with atoms in the ground state of a lattice potential V(x) =V0cos [ 2 kx + ϕ(t) ] , we show that it is possible to transform from one atomic wavefunction to another by a prescribed shaking of the lattice, i.e., by an appropriately tailored time-dependent phase shift ϕ(t) . In particular, the standard interferometer sequence of beam splitting, propagation, reflection, reverse propagation, and recombination can be achieved via a set of phase modulation operations {ϕj(t) } . Each ϕj(t) is determined using a learning algorithm, and the split-step method calculates the wavefunction dynamics. We have numerically demonstrated an interferometer in which the shaken wavefunctions match the target states to better than 1 % . We carried out learning using a genetic algorithm and optimal control techniques. The atoms remain trapped in the lattice throughout the full interferometer sequence. Thus, the approach may be suitable for use in an dynamic environment. In addition to the general principles, we discuss aspects of the experimental implementation. Supported by the Office of Naval Research (ONR) and Northrop Grumman.

  18. Preview of Blackbeard interferometry

    Science.gov (United States)

    Carter, M. J.

    Blackbeard is a broadband VHF measurement satellite experiment designed and built by the Space Science and Technology Division of the Los Alamos National Laboratory. Blackbeard is a piggy-back experiment on the ALEXIS satellite to be launched into a 70 degree inclination orbit at an altitude of 750 km. The satellite experimental operation and data retrieval are controlled through a telemetry link from the Satellite Operations Center (SOC) located at Los Alamos, NM. The primary experimental objectives of Blackbeard are three-fold: (1) Study the dispersion of broad-band impulsive electromagnetic signals -- in particular, the higher-order amplitude and phase distortion due to propagation through the ionosphere. These depend on ionospheric conditions and irregularities. (2) Utilize RF interferometry and scintillation techniques in the low VHF-band to determine the size and extent of ionospheric irregularities and wave structure -- both natural and artificially induced. This narrow-band data will be used to categorize the ionospheric media as undisturbed, oscillatory, or turbulent. These parameters will then be input into transfer function simulations for broad-band propagation and compared with broad-band propagation data from Blackbeard. (3) Survey and characterize background noise in the VHF-band-consisting of (1) cataloging broadcast amplitudes and signatures and mapping their global pattern, and (2) cataloging the signatures of lightning events. Also, correlate emissions in the visible and VHF bands in an attempt to confirm broad-band RF emissions assumed to be associated with lightning.

  19. Landau-Zener-Stueckelberg interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Shevchenko, S.N., E-mail: sshevchenko@ilt.kharkov.u [B.Verkin Institute for Low Temperature Physics and Engineering, Kharkov (Ukraine); RIKEN Advanced Science Institute, Wako-shi, Saitama (Japan); Ashhab, S.; Nori, Franco [RIKEN Advanced Science Institute, Wako-shi, Saitama (Japan); Department of Physics, The University of Michigan, Ann Arbor, MI (United States)

    2010-07-15

    A transition between energy levels at an avoided crossing is known as a Landau-Zener transition. When a two-level system (TLS) is subject to periodic driving with sufficiently large amplitude, a sequence of transitions occurs. The phase accumulated between transitions (commonly known as the Stueckelberg phase) may result in constructive or destructive interference. Accordingly, the physical observables of the system exhibit periodic dependence on the various system parameters. This phenomenon is often referred to as Landau-Zener-Stueckelberg (LZS) interferometry. Phenomena related to LZS interferometry occur in a variety of physical systems. In particular, recent experiments on LZS interferometry in superconducting TLSs (qubits) have demonstrated the potential for using this kind of interferometry as an effective tool for obtaining the parameters characterizing the TLS as well as its interaction with the control fields and with the environment. Furthermore, strong driving could allow for fast and reliable control of the quantum system. Here we review recent experimental results on LZS interferometry, and we present related theory.

  20. Phase estimation in optical interferometry

    CERN Document Server

    Rastogi, Pramod

    2014-01-01

    Phase Estimation in Optical Interferometry covers the essentials of phase-stepping algorithms used in interferometry and pseudointerferometric techniques. It presents the basic concepts and mathematics needed for understanding the phase estimation methods in use today. The first four chapters focus on phase retrieval from image transforms using a single frame. The next several chapters examine the local environment of a fringe pattern, give a broad picture of the phase estimation approach based on local polynomial phase modeling, cover temporal high-resolution phase evaluation methods, and pre

  1. Speckle fields in holographic interferometry

    Science.gov (United States)

    Lockshin, Gennady R.; Kozel, Stanislav M.; Bielonuchkin, V. E.

    1990-07-01

    The objects which are investigated which are investigated with the help of the holographic interferometry methods as a rule scatter light diffusely, therefore the two-expositional hologram reconstructs the result of interference of the speckle-fields f ('4 and f() scattered by th object at the initial (1) and final (2) states.

  2. Extraction of the strong neutron-proton mass difference from the charge symmetry breaking in pn->dpi{sup 0}

    Energy Technology Data Exchange (ETDEWEB)

    Filin, A.; Baru, V. [Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Theoretical and Experimental Physics, 117218, B. Cheremushkinskaya 25, Moscow (Russian Federation); Epelbaum, E. [Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Haidenbauer, J., E-mail: j.haidenbauer@fz-juelich.d [Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany); Hanhart, C. [Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany); Kudryavtsev, A. [Institute for Theoretical and Experimental Physics, 117218, B. Cheremushkinskaya 25, Moscow (Russian Federation); Meissner, U.-G. [Institut fuer Kernphysik (Theorie) and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany)

    2009-11-16

    We perform a complete calculation of charge symmetry breaking effects for the reaction pn->dpi{sup 0} at leading order in chiral perturbation theory. A new leading-order operator is included. From our analysis we extract deltam{sub N}{sup str}, the strong contribution to the neutron-proton mass difference. The value obtained, deltam{sub N}{sup str}=(1.5+-0.8 (exp.)+-0.5 (th.)) MeV, is consistent with the result based on the Cottingham sum rule. This agreement provides a non-trivial test of our current understanding of the chiral structure of QCD.

  3. Precision Geodesy via Radio Interferometry.

    Science.gov (United States)

    Hinteregger, H F; Shapiro, I I; Robertson, D S; Knight, C A; Ergas, R A; Whitney, A R; Rogers, A E; Moran, J M; Clark, T A; Burke, B F

    1972-10-27

    Very-long-baseline interferometry experiments, involving observations of extragalactic radio sources, were performed in 1969 to determine the vector separations between antenna sites in Massachusetts and West Virginia. The 845.130-kilometer baseline was estimated from two separate experiments. The results agreed with each other to within 2 meters in all three components and with a special geodetic survey to within 2 meters in length; the differences in baseline direction as determined by the survey and by interferometry corresponded to discrepancies of about 5 meters. The experiments also yielded positions for nine extragalactic radio sources, most to within 1 arc second, and allowed the hydrogen maser clocks at the two sites to be synchronized a posteriori with an uncertainty of only a few nanoseconds.

  4. Angular-domain scattering interferometry.

    Science.gov (United States)

    Shipp, Dustin W; Qian, Ruobing; Berger, Andrew J

    2013-11-15

    We present an angular-scattering optical method that is capable of measuring the mean size of scatterers in static ensembles within a field of view less than 20 μm in diameter. Using interferometry, the method overcomes the inability of intensity-based models to tolerate the large speckle grains associated with such small illumination areas. By first estimating each scatterer's location, the method can model between-scatterer interference as well as traditional single-particle Mie scattering. Direct angular-domain measurements provide finer angular resolution than digitally transformed image-plane recordings. This increases sensitivity to size-dependent scattering features, enabling more robust size estimates. The sensitivity of these angular-scattering measurements to various sizes of polystyrene beads is demonstrated. Interferometry also allows recovery of the full complex scattered field, including a size-dependent phase profile in the angular-scattering pattern.

  5. Radar interferometry persistent scatterer technique

    CERN Document Server

    Kampes, Bert M

    2014-01-01

    This volume is devoted to the Persistent Scatterer Technique, the latest development in radar interferometric data processing. It is the only book on Permanent Scatterer (PS) technique of radar interferometry, and it details a newly developed stochastic model and estimator algorithm to cope with possible problems for the application of the PS technique. The STUN (spatio-temporal unwrapping network) algorithm, developed to cope with these issues in a robust way, is presented and applied to two test sites.

  6. Holographic interferometry in construction analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hartikainen, T.

    1995-12-31

    In this work techniques for visualizing phase and opaque objects by ruby laser interferometry are introduced. A leakage flow as a phase object is studied by holographic interferometry and the intensity distribution of the interferograms presenting the leakage flow are computer-simulated. A qualitative and quantitative analysis of the leakage flow is made. The analysis is based on the experimental and theoretical results presented in this work. The holographic setup and the double pass method for visualizing leakage flow are explained. A vibrating iron plate is the opaque object. Transient impact waves are generated by a pistol bullet on the iron plate and visualized by holographic interferometry. An apparatus with the capability of detecting and calculating the delays necessary for laser triggering is introduced. A time series of interferograms presenting elastic wave formation in an iron plate is shown. A computer-simulation of the intensity distributions of these interferograms is made. An analysis based on the computer-simulation and the experimental data of the transient elastic wave is carried out and the results are presented. (author)

  7. Holographic interferometry of high pressure

    International Nuclear Information System (INIS)

    McIlwain, M.E.

    1987-01-01

    Measurements in turbulent flows have been historically performed using various types of probes and optical diagnostic methods. In general, probes suffer from plasma perturbation effects and are single point determination methods. Optical methods appear to be better suited to determinations in turbulent flows, however interpretation of the resulting data can often be complex. Methods such as laser Doppler anemometry, which relies on entrained particles, suffers from the fact that particles small enough to be swept along by the plasma are usually melted or sublimed in the plasma. Light refraction or diffraction methods such as shadow photography, interferometry, and holography have also been used to observe plasma flows. These methods typically suffer from the difficulty of interpreting line of sight images and obtaining quantitative data. A new method based on multi-pass holographic interferometry will be discussed. This method has certain advantages which can significantly simplify the complexity of line of sight interferometry image deconvolution. When the method employs high speed cinematography, time resolved images of the plasma flow can be obtained. This method has been applied to both transferred and non-transferred arcs and various types of DC-plasma torch produced jets. These studies and conclusions as to the usefulness of the technique are presented

  8. DPY-17 and MUA-3 Interact for Connective Tissue-Like Tissue Integrity in Caenorhabditis elegans: A Model for Marfan Syndrome.

    Science.gov (United States)

    Fotopoulos, Pauline; Kim, Jeongho; Hyun, Moonjung; Qamari, Waiss; Lee, Inhwan; You, Young-Jai

    2015-04-27

    mua-3 is a Caenorhabditis elegans homolog of the mammalian fibrillin1, a monogenic cause of Marfan syndrome. We identified a new mutation of mua-3 that carries an in-frame deletion of 131 amino acids in the extracellular domain, which allows the mutants to survive in a temperature-dependent manner; at the permissive temperature, the mutants grow normally without obvious phenotypes, but at the nonpermissive temperature, more than 90% die during the L4 molt due to internal organ detachment. Using the temperature-sensitive lethality, we performed unbiased genetic screens to isolate suppressors to find genetic interactors of MUA-3. From two independent screens, we isolated mutations in dpy-17 as a suppressor. RNAi of dpy-17 in mua-3 rescued the lethality, confirming dpy-17 is a suppressor. dpy-17 encodes a collagen known to genetically interact with dpy-31, a BMP-1/Tolloid-like metalloprotease required for TGFβ activation in mammals. Human fibrillin1 mutants fail to sequester TGFβ2 leading to excess TGFβ signaling, which in turn contributes to Marfan syndrome or Marfan-related syndrome. Consistent with that, RNAi of dbl-1, a TGFβ homolog, modestly rescued the lethality of mua-3 mutants, suggesting a potentially conserved interaction between MUA-3 and a TGFβ pathway in C. elegans. Our work provides genetic evidence of the interaction between TGFβ and a fibrillin homolog, and thus provides a simple yet powerful genetic model to study TGFβ function in development of Marfan pathology. Copyright © 2015 Fotopoulos et al.

  9. CURIE: Cubesat Radio Interferometry Experiment

    Science.gov (United States)

    Sundkvist, D. J.; Saint-Hilaire, P.; Bain, H. M.; Bale, S. D.; Bonnell, J. W.; Hurford, G. J.; Maruca, B.; Martinez Oliveros, J. C.; Pulupa, M.

    2016-12-01

    The CUbesat Radio Interferometry Experiment (CURIE) is a proposed two-element radio interferometer, based on proven and developed digital radio receivers and designed to fit within a Cubesat platform. CURIE will launch as a 6U Cubesat and then separate into two 3U Cubesats once in orbit. CURIE measures radio waves from 0.1-19MHz, which must be measured from space, as those frequencies fall below the cutoff imposed by Earth's ionosphere. The principal science objective for CURIE is to use radio interferometry to study radio burst emissions from solar eruptive events such as flares and coronal mass ejections (CMEs) in the inner heliosphere, providing observations important for our understanding of the heliospheric space weather environment. The influence of space weather can be felt at Earth and other planets, as radiation levels increase and lead to auroral activity and geomagnetic effects. CURIE will be able to determine the location and size of radio burst source regions and then to track their movement outward from the Sun. In addition to the primary objective CURIE will measure the gradients of the local ionospheric density and electron temperature on the spatial scale of a few kilometers, as well as create an improved map of the radio sky at these unexplored frequencies. A space based radio interferometry observatory has long been envisioned, in orbit around the Earth or the Moon, or on the far side of the Moon. Beyond its important science objectives, CURIE will prove that the concept of a dedicated space-based interferometer can be realized by using relatively cheap Cubesats. CURIE will therefore not only provide new important science results but also serve as a pathfinder in the development of new space-based radio observation techniques for helio- and astro-physics.

  10. Influence of absorption in linear polarization imaging of melanoma tissues

    Directory of Open Access Journals (Sweden)

    Dongzhi Li

    2014-05-01

    Full Text Available The contrast mechanism of different polarization imaging techniques for melanoma in mouse skin is studied using both experiments and Monte Carlo simulations. Total intensity, linear polarization difference imaging (DPI, degree of polarization imaging (DOPI and rotating linear polarization imaging (RLPI are applied and the relative contrasts of these polarization imaging methods between the normal and cancerous tissues are compared. A two-layer absorption-scattering model is proposed to explain the contrast mechanism of the polarization imaging for melanoma. By taking into account of both scattering of symmetrical and asymmetrical scatterers and absorption of inter-scatterer medium, the two-layer model reproduces the relative contrasts for polarization images observed in experiments. The simulation results also show that, the parameters of polarization imaging change more dramatically with the variation of absorption in the bottom layer than the top layer.

  11. Attosecond electron wave packet interferometry

    International Nuclear Information System (INIS)

    Remetter, T.; Ruchon, T.; Johnsson, P.; Varju, K.; Gustafsson, E.

    2006-01-01

    Complete test of publication follows. The well controlled generation and characterization of attosecond XUV light pulses provide an unprecedented tool to study electron wave packets (EWPs). Here a train of attosecond pulses is used to create and study the phase of an EWP in momentum space. There is a clear analogy between electronic wave functions and optical fields. In optics, methods like SPIDER or wave front shearing interferometry, allow to measure the spectral or spatial phase of a light wave. These two methods are based on the same principle: an interferogram is produced when recombining two sheared replica of a light pulse, spectrally (SPIDER) or spatially (wave front shearing interferometry). This enables the comparison of two neighbouring different spectral or spatial slices of the original wave packet. In the experiment, a train of attosecond pulses is focused in an Argon atomic gas jet. EWPs are produced from the single XUV photon ionization of Argon atoms. If an IR beam is synchronized to the EWPs, it is possible to introduce a shear in momentum space between two consecutive s wave packets. A Velocity Map Imaging Spectrometer (VMIS) enables us to detect the interference pattern. An analysis of the interferograms will be presented leading to a conclusion about the symmetry of the studied wave packet.

  12. Wave-particle dualism in matter wave interferometry

    International Nuclear Information System (INIS)

    Rauch, H.

    1984-01-01

    Neutron interferometry is a unique tool for investigations in the field of particle-wave dualism because massive elementary particles behave like waves within the interferometer. The invention of perfect crystal neutron interferometers providing widely separated coherent beams stimulated a great variety of experiments with matter waves in the field of basic quantum mechanics. The phase of the spatial and spinor wave function become a measurable quantity and can be influenced individually. High degrees of coherence and high order interferences have been observed by this technique. The 4π-symmetry of a spinor wave function and the mutual modulation of nuclear and magnetic phase shifts have been measured in the past. Recent experiments dealt with polarized neutron beams, which are handled to realize the spin-superposition of two oppositionally polarized subbeams resulting in final polarization perpendicular to both initial beam polarizations. The different action on the coherent beams of static and dynamic flippers have been visualized. Monolithic multicrystal arrangements in Laue position can also be used to achieve an extremely high energy (10 -9 eV) or angular resolution (0.001 sec of arc). This feature is based on the Pendelloesung interference within the perfect crystal. A transverse coherence length up to 6.5 mm is deduced from single slit diffraction experiments. (Auth.)

  13. Two particle interferometry at RHIC

    CERN Document Server

    Laue, F

    2002-01-01

    We present preliminary results from a pion interferometry analysis of Au+Au collisions at square root (S/sub NN/)=130 GeV, recorded with the STAR (Solenoidal Tracker At RHIC) detector at the Relativistic Heavy Ion Collider (RHIC). The evaluation of three-dimensional correlation functions indicates increasing source sizes with increasing event centrality. The dependence of the calculated HBT radii on transverse momentum is attributed to strong space-momentum correlations (transverse flow). In the study presented in this paper we have not observed anomalously large source sizes as have been predicted as a signal for quark-qluon plasma formation. However, the measured HBT radii seem to follow the trend established at lower energies (AGS/SPS). We find the ratio R/sub o//R/sub s/ approximately =1, suggesting a short duration of pion emission. The "universal" pion phase space density, observed at AGS/SPS, seems to hold also at RHIC. (26 refs).

  14. Synthetic aperture interferometry: error analysis

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Amiya; Coupland, Jeremy

    2010-07-10

    Synthetic aperture interferometry (SAI) is a novel way of testing aspherics and has a potential for in-process measurement of aspherics [Appl. Opt.42, 701 (2003)].APOPAI0003-693510.1364/AO.42.000701 A method to measure steep aspherics using the SAI technique has been previously reported [Appl. Opt.47, 1705 (2008)].APOPAI0003-693510.1364/AO.47.001705 Here we investigate the computation of surface form using the SAI technique in different configurations and discuss the computational errors. A two-pass measurement strategy is proposed to reduce the computational errors, and a detailed investigation is carried out to determine the effect of alignment errors on the measurement process.

  15. Synthetic aperture interferometry: error analysis

    International Nuclear Information System (INIS)

    Biswas, Amiya; Coupland, Jeremy

    2010-01-01

    Synthetic aperture interferometry (SAI) is a novel way of testing aspherics and has a potential for in-process measurement of aspherics [Appl. Opt.42, 701 (2003)].APOPAI0003-693510.1364/AO.42.000701 A method to measure steep aspherics using the SAI technique has been previously reported [Appl. Opt.47, 1705 (2008)].APOPAI0003-693510.1364/AO.47.001705 Here we investigate the computation of surface form using the SAI technique in different configurations and discuss the computational errors. A two-pass measurement strategy is proposed to reduce the computational errors, and a detailed investigation is carried out to determine the effect of alignment errors on the measurement process.

  16. Some applications of holographic interferometry in biomechanics

    Science.gov (United States)

    Ebbeni, Jean P. L.

    1992-03-01

    Holographic interferometry is well adapted for the determination of 2D strain fields in osseous structures. The knowledge of those strain fields is important for the understanding of structure behavior such as arthrosis.

  17. Space Interferometry Mission Instrument Mechanical Layout

    Science.gov (United States)

    Aaron, K.; Stubbs, D.; Kroening, K.

    2000-01-01

    The Space Interferometry Mission, planned for launch in 2006, will measure the positions of celestial objects to an unprecedented accuracy of 4x10 to the power of negative six arc (about 1 billionth of a degree).

  18. High-contrast Nulling Interferometry Techniques Project

    Data.gov (United States)

    National Aeronautics and Space Administration — "We are developing rotating-baseline nulling-interferometry techniques and algorithms on the single-aperture Hale and Keck telescopes at near-infrared wavelengths,...

  19. Fundamental physics research and neutron interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Ioffe, A. [Hahn-Meitner-Institut Berlin GmbH (Germany)

    1996-08-01

    The possibility of the use of an extremely sensitive neutron interferometry technique for the study of electromagnetic structure of the neutron and the parity non-conservative effects in neutron spin rotation is discussed. (author)

  20. Novel Polarimetric SAR Interferometry Algorithms, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Polarimetric SAR interferometry (PolInSAR) is a recently developed synthetic aperture radar (SAR) imaging mode that combines the capabilities of radar polarimetry...

  1. Novel Polarimetric SAR Interferometry Algorithms, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Polarimetric radar interferometry (PolInSAR) is a new SAR imaging mode that is rapidly becoming an important technique for bare earth topographic mapping, tree...

  2. Speckle Shearing Interferometry And Its Application

    Science.gov (United States)

    Jingtang, Ke; Hongqing, Zhang; Yeling, He; Yanfu, Chang

    1983-12-01

    The paper deals with experiments made to verify the theory of bending of plates and related problems by method of speckle shearing interferometry, which is proved to be highly sensitive. Tests carried out on rubber products: (such as tires)and thin-walled containers have demonstrated the prospects of using image-shearing camera in nondestructive in-situ testing of industrial products, suggesting a potentiality still wider than that of holographic interferometry.

  3. Spherical grating based x-ray Talbot interferometry

    International Nuclear Information System (INIS)

    Cong, Wenxiang; Xi, Yan; Wang, Ge

    2015-01-01

    Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

  4. 2. Interferometry and polarimetry. 2.1. Principle of interferometry and polarimetry

    International Nuclear Information System (INIS)

    Kawahata, Kazuo; Okajima, Shigeki

    2000-01-01

    Laser interferometry and polarimetry are useful diagnostics for measuring electron density and the internal magnetic field distribution in the plasma. In this section, principles of interferometry and polarimetry and their applications to plasma diagnostics on LHD (section 2.2) and JT-60 (section 2.3) are descried. (author)

  5. Full-field parallel interferometry coherence probe microscope for high-speed optical metrology.

    Science.gov (United States)

    Safrani, A; Abdulhalim, I

    2015-06-01

    Parallel detection of several achromatic phase-shifted images is used to obtain a high-speed, high-resolution, full-field, optical coherence probe tomography system based on polarization interferometry. The high enface imaging speed, short coherence gate, and high lateral resolution provided by the system are exploited to determine microbump height uniformity in an integrated semiconductor chip at 50 frames per second. The technique is demonstrated using the Linnik microscope, although it can be implemented on any polarization-based interference microscopy system.

  6. Theory of supervirtual refraction interferometry

    KAUST Repository

    Bharadwaj, Pawan

    2012-01-01

    Inverting for the subsurface velocity distribution by refraction traveltime tomography is a well-accepted imaging method by both the exploration and earthquake seismology communities. A significant drawback, however, is that the recorded traces become noisier with increasing offset from the source position, and so accurate picking of traveltimes in far-offset traces is often prevented. To enhance the signal-to-noise ratio (SNR) of the far-offset traces, we present the theory of supervirtual refraction interferometry where the SNR of far-offset head-wave arrivals can be theoretically increased by a factor proportional to; here, N is the number of receiver or source positions associated with the recording and generation of the head-wave arrival. There are two steps to this methodology: correlation and summation of the data to generate traces with virtual head-wave arrivals, followed by the convolution of the data with the virtual traces to create traces with supervirtual head-wave arrivals. This method is valid for any medium that generates head-wave arrivals recorded by the geophones. Results with both synthetic traces and field data demonstrate the feasibility of this method. There are at least four significant benefits of supervirtual interferometry: (1) an enhanced SNR of far-offset traces so the first-arrival traveltimes of the noisy far-offset traces can be more reliably picked to extend the useful aperture of the data, (2) the SNR of head waves in a trace that arrive later than the first arrival can be enhanced for accurate traveltime picking and subsequent inversion by later-arrival traveltime tomography, (3) common receiver-pair gathers can be analysed to detect the presence of diving waves in the first arrivals, which can be used to assess the nature of the refracting boundary, and (4) the source statics term is eliminated in the correlation operations so that the timing of the virtual traces is independent of the source excitation time. This suggests the

  7. Parsimonious Refraction Interferometry and Tomography

    KAUST Repository

    Hanafy, Sherif

    2017-02-04

    We present parsimonious refraction interferometry and tomography where a densely populated refraction data set can be obtained from two reciprocal and several infill shot gathers. The assumptions are that the refraction arrivals are head waves, and a pair of reciprocal shot gathers and several infill shot gathers are recorded over the line of interest. Refraction traveltimes from these shot gathers are picked and spawned into O(N2) virtual refraction traveltimes generated by N virtual sources, where N is the number of geophones in the 2D survey. The virtual traveltimes can be inverted to give the velocity tomogram. This enormous increase in the number of traveltime picks and associated rays, compared to the many fewer traveltimes from the reciprocal and infill shot gathers, allows for increased model resolution and a better condition number with the system of normal equations. A significant benefit is that the parsimonious survey and the associated traveltime picking is far less time consuming than that for a standard refraction survey with a dense distribution of sources.

  8. LED driver for stroboscopic interferometry

    Science.gov (United States)

    Paulin, T.; Heikkinen, V.; Kassamakov, I.; Hæggström, E.

    2012-04-01

    Three different types of white light emitting diodes (LEDs) and three types of single color LEDs were tested as light sources for stroboscopic scanning white light interferometry (SSWLI) for dynamic (MEMS) characterization. Short, intense, light pulses and low duty cycle (DC-10 MHz), and can drive single LEDs at 5A peak current (0.7% duty cycle at 1 MHz). The shortest measured electrical pulses were 6.2 +/- 0.1 ns FDHM. The minimum measured Full Duration at Half Maximum (FDHM) of the optical pulse was 8.4 +/- 0.1 ns using nonphosphor white LED and 32.1 +/- 0.1 ns using white phosphor-converted LED (0.7 % duty cycle at 1 MHz in both cases). The minimum optical pulse FDHM for a single color blue/green LED was 6.4 +/- 0.1 ns. The maximum intensity of these pulses was 630 +/- 40 μW and 540 +/- 30 μW, respectively. All types of white LEDs could be used for stroboscopic SWLI measurements at frequencies up to 2 MHz. For higher frequencies, non-phosphor white LEDs must be used together with a cyan LED to avoid ringing in the SWLI interferogram.

  9. 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.

  10. Astronomical optical interferometry, I: Methods and instrumentation

    Directory of Open Access Journals (Sweden)

    Jankov S.

    2010-01-01

    Full Text Available Previous decade has seen an achievement of large interferometric projects including 8-10m telescopes and 100m class baselines. Modern computer and control technology has enabled the interferometric combination of light from separate telescopes also in the visible and infrared regimes. Imaging with milli-arcsecond (mas resolution and astrometry with micro-arcsecond (µas precision have thus become reality. Here, I review the methods and instrumentation corresponding to the current state in the field of astronomical optical interferometry. First, this review summarizes the development from the pioneering works of Fizeau and Michelson. Next, the fundamental observables are described, followed by the discussion of the basic design principles of modern interferometers. The basic interferometric techniques such as speckle and aperture masking interferometry, aperture synthesis and nulling interferometry are discussed as well. Using the experience of past and existing facilities to illustrate important points, I consider particularly the new generation of large interferometers that has been recently commissioned (most notably, the CHARA, Keck, VLT and LBT Interferometers. Finally, I discuss the longer-term future of optical interferometry, including the possibilities of new large-scale ground-based projects and prospects for space interferometry.

  11. Polarization Observations of the Fermi blazars

    Science.gov (United States)

    Rani, Bindu; S. Jorstad, A. P. Marscher (BU, USA), K. Sokolovsky (IAASARS, Greece), I. Agudo (CSIC, Spain)

    2018-01-01

    Ever since the revolutionary discovery by the Fermi mission that active galactic nuclei (AGN) produce copious amounts of high-energy emission, its origin has remained elusive. Using high-frequency radio interferometry (VLBI) polarization imaging, we could probe the magnetic field topology of the compact high-energy emission regions in blazars. A case study for blazar 3C 279 reveals presence of multiple gamma-ray emission regions. The observed anti-correlation between gamma-ray flux and percentage polarization at optical bands challenges the current high-energy emission models. In addition to the turbulent component responsible for gamma-ray flares, our analysis suggests the presence of a steady polarized component having with its polarization direction aligned along the jet axis. The steady polarized component could possibly be the toroidal component of the helical magnetic field. To better understand the acceleration processes in jets, high-energy polarization missions are of great importance.

  12. Wide band interferometry for thickness measurement

    Science.gov (United States)

    Costantino, Santiago; Martinez, Oscar E.; Torga, Jorge R.

    2003-04-01

    In this work we present the concept of wide band interferometry as opposed to white-light interferometry to introduce a thickness measurement method that gains precision when the bandwidth is reduced to an adequate compromise in order to avoid the distortions arising from the material dispersion. The use of the widest possible band is a well established dogma when the highest resolution is desired in distance measurements with white-light interferometry. We will show that the dogma falls when thickness measurements must be carried out due to material dispersion. In fact the precise knowledge of the frequency dependence of the refractive index is essential for adequate thickness retrieval from the optical experiments. The device we present is also useful to obtain the group refractive index that is necessary to calculate the absolute thickness value. As an example, we show the spreading of a silicone oil on a reference surface in real time.

  13. Demonstration of X-ray talbot interferometry

    CERN Document Server

    Momose, A; Kawamoto, S; Hamaishi, Y; Takai, K; Suzuki, Y

    2003-01-01

    First Talbot interferometry in the hard X-ray region was demonstrated using a pair of transmission gratings made by forming gold stripes on glass plates. By aligning the gratings on the optical axis of X-rays with a separation that caused the Talbot effect by the first grating, moire fringes were produced inclining one grating slightly against the other around the optical axis. A phase object placed in front of the first grating was detected by moire-fringe bending. Using the technique of phase-shifting interferometry, the differential phase corresponding to the phase object could also be measured. This result suggests that X-ray Talbot interferometry is a novel and simple method for phase-sensitive X-ray radiography. (author)

  14. Moire interferometry at high temperatures

    Science.gov (United States)

    Wu, Jau-Je

    1992-01-01

    The objective of this study was to provide an optical technique allowing full-field in-plane deformation measurements at high temperature by using high-sensitivity moire interferometry. This was achieved by a new approach of performing deformation measurements at high temperatures in a vacuum oven using an achromatic interferometer. The moire system setup was designed with particular consideration for the stability, compactness, flexibility, and ease of control. A vacuum testing environment was provided to minimize the instability of the patterns by protecting the optical instruments from the thermal convection currents. Also, a preparation procedure for the high-temperature specimen grating was developed with the use of the plasma-etched technique. Gold was used as a metallic layer in this procedure. This method was demonstrated on a ceramic block, metal/matrix composite, and quartz. Thermal deformation of a quartz specimen was successfully measured in vacuum at 980 degrees Celsius, with the sensitivity of 417 nm per fringe. The stable and well-defined interference patterns confirmed the feasibility of the developments, including the high-temperature moire system and high-temperature specimen grating. The moire system was demonstrated to be vibration-insensitive. Also, the contrast of interference fringes at high temperature was enhanced by means of a spatial filter and a narrow band interference filter to minimize the background noise from the flow of the specimen and heater. The system was verified by a free thermal expansion test of an aluminum block. Good agreement demonstrated the validity of the optical design. The measurements of thermal deformation mismatch were performed on a graphite/epoxy composite, a metal/matrix composite equipped with an optical fiber, and a cutting tool bit. A high-resolution data-reduction technique was used to measure the strain distribution of the cutting tool bit.

  15. Cold neutron interferometry and its application. 2. Coherency and cold neutron spin interferometry

    International Nuclear Information System (INIS)

    Achiwa, Norio; Ebisawa, Toru

    1998-03-01

    The second workshop entitled 'Interference studies and cold neutron spin interferometry' was held on 10 and 11 March 1998 at KUR (Kyoto University Research Reactor Institute, Kumatori). Cold neutron spin interferometry is a new field. So it is very important for its development to learn the studies of X-ray and neutron optics which are rapidly developing with long history. In the workshop, the issues related to interference were reviewed such as experimental studies on cold neutron spin interferometry, theoretical and experimental approach on tunneling time, interference experiments by neutrons and its application, interference studies using synchrotron radiation, topics on silicon interferometry and quantum measurement problem and cold neutron interference experiment related to quantum measurement problem. The 8 of the presented papers are indexed individually. (J.P.N.)

  16. Precision measurements with atom interferometry

    Science.gov (United States)

    Schubert, Christian; Abend, Sven; Schlippert, Dennis; Ertmer, Wolfgang; Rasel, Ernst M.

    2017-04-01

    Interferometry with matter waves enables precise measurements of rotations, accelerations, and differential accelerations [1-5]. This is exploited for determining fundamental constants [2], in fundamental science as e.g. testing the universality of free fall [3], and is applied for gravimetry [4], and gravity gradiometry [2,5]. At the Institut für Quantenoptik in Hannover, different approaches are pursued. A large scale device is designed and currently being set up to investigate the gain in precision for gravimetry, gradiometry, and fundamental tests on large baselines [6]. For field applications, a compact and transportable device is being developed. Its key feature is an atom chip source providing a collimated high flux of atoms which is expected to mitigate systematic uncertainties [7,8]. The atom chip technology and miniaturization benefits from microgravity experiments in the drop tower in Bremen and sounding rocket experiments [8,9] which act as pathfinders for space borne operation [10]. This contribution will report about our recent results. The presented work is supported by the CRC 1227 DQ-mat, the CRC 1128 geo-Q, the RTG 1729, the QUEST-LFS, and by the German Space Agency (DLR) with funds provided by the Federal Ministry of Economic Affairs and Energy (BMWi) due to an enactment of the German Bundestag under Grant No. DLR 50WM1552-1557. [1] P. Berg et al., Phys. Rev. Lett., 114, 063002, 2015; I. Dutta et al., Phys. Rev. Lett., 116, 183003, 2016. [2] J. B. Fixler et al., Science 315, 74 (2007); G. Rosi et al., Nature 510, 518, 2014. [3] D. Schlippert et al., Phys. Rev. Lett., 112, 203002, 2014. [4] A. Peters et al., Nature 400, 849, 1999; A. Louchet-Chauvet et al., New J. Phys. 13, 065026, 2011; C. Freier et al., J. of Phys.: Conf. Series 723, 012050, 2016. [5] J. M. McGuirk et al., Phys. Rev. A 65, 033608, 2002; P. Asenbaum et al., arXiv:1610.03832. [6] J. Hartwig et al., New J. Phys. 17, 035011, 2015. [7] H. Ahlers et al., Phys. Rev. Lett. 116, 173601

  17. Astronomical Optical Interferometry. I. Methods and Instrumentation

    Directory of Open Access Journals (Sweden)

    Jankov, S.

    2010-12-01

    Full Text Available Previous decade has seen an achievement of large interferometricprojects including 8-10m telescopes and 100m class baselines. Modern computerand control technology has enabled the interferometric combination of lightfrom separate telescopes also in the visible and infrared regimes. Imagingwith milli-arcsecond (mas resolution and astrometry with micro-arcsecond($mu$as precision have thus become reality. Here, I review the methods andinstrumentation corresponding to the current state in the field ofastronomical optical interferometry. First, this review summarizes thedevelopment from the pioneering works of Fizeau and Michelson. Next, thefundamental observables are described, followed by the discussion of the basicdesign principles of modern interferometers. The basic interferometrictechniques such as speckle and aperture masking interferometry, aperture synthesisand nulling interferometry are disscused as well. Using the experience ofpast and existing facilities to illustrate important points, I considerparticularly the new generation of large interferometers that has beenrecently commissioned (most notably, the CHARA, Keck, VLT and LBTInterferometers. Finally, I discuss the longer-term future of opticalinterferometry, including the possibilities of new large-scale ground-based projects and prospects for space interferometry.

  18. Seismic interferometry-turning noise into signal

    NARCIS (Netherlands)

    Curtis, A.; Gerstoft, P.; Sato, H.; Snieder, R.; Wapenaar, C.P.A.

    2006-01-01

    Turning noise into useful data—every geophysicist's dream? And now it seems possible. The field of seismic interferometry has at its foundation a shift in the way we think about the parts of the signal that are currently filtered out of most analyses—complicated seismic codas (the multiply scattered

  19. Monitoring civil infrastructure using satellite radar interferometry

    NARCIS (Netherlands)

    Chang, L.

    2015-01-01

    Satellite radar interferometry (InSAR) is a precise and efficient technique to monitor deformation on Earth with millimeter precision. Most InSAR applications focus on geophysical phenomena, such as earthquakes, volcanoes, or subsidence. Monitoring civil infrastructure with InSAR is relatively new,

  20. Photopolymer for Optical Holography and Holographic Interferometry

    Czech Academy of Sciences Publication Activity Database

    Květoň, M.; Lédl, Vít; Havránek, A.; Fiala, P.

    2010-01-01

    Roč. 295, č. 1 (2010), s. 107-113 ISSN 1022-1360 Institutional research plan: CEZ:AV0Z20430508 Keywords : holographic interferometry * holography * photopolymerization * recording material * refractive index Subject RIV: BH - Optics, Masers, Lasers http://onlinelibrary.wiley.com/doi/10.1002/masy.200900093/pdf

  1. Vliv apocyninu a DPI na tvorbu oxidu dusnatého myšími makrofágy po stimulaci endotoxinem

    Czech Academy of Sciences Publication Activity Database

    Krejčová, D.; Lojek, Antonín; Kubala, Lukáš

    2008-01-01

    Roč. 10, č. 2 (2008), s. 130-131 ISSN 1212-3536. [Sjezd českých a slovenských alergologů a klinických imunologů /25./ a Kongres českých a slovenských imunologů s mezinárodní účastí /12./. 29.10.2008-1.11.2008, Praha] R&D Projects: GA ČR(CZ) GA524/06/1197 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : apocynin * DPI * RAW 264.7 Subject RIV: BO - Biophysics

  2. Future Looks Bright for Interferometry

    Science.gov (United States)

    2008-09-01

    First Light for the PRIMA instrument The PRIMA instrument [1] of the ESO Very Large Telescope Interferometer (VLTI) recently saw "first light" at its new home atop Cerro Paranal in Chile. When fully operational, PRIMA will boost the capabilities of the VLTI to see sources much fainter than any previous interferometers, and enable astrometric precision unmatched by any other existing astronomical facility. PRIMA will be a unique tool for the detection of exoplanets. First Light of the PRIMA Instrument ESO PR Photo 29a/08 Preparing for PRIMA "PRIMA is specifically designed to see if one star 'wobbles' to and fro because it is has unseen planetary companions", says instrument scientist Gerard van Belle. "This allows us to not only detect exoplanets, but to measure their mass." PRIMA's expected astrometric precision of tens of micro-arcseconds is unmatched by any other existing astronomical facility, whether on the ground or in orbit [2]. In addition to taking astrometric measurements PRIMA will be the key to the imaging of faint sources with the VLTI using the science instruments AMBER and MIDI. Interferometry combines the light received by two or more telescopes, concentrating on tiny differences between the signals to measure angles with exquisite precision. Using this technique PRIMA can pick out details as sharply as a single telescope with a diameter equivalent to the largest distance between the telescopes. For the VLTI, the distance between the two telescope elements is about 200 metres. The PRIMA instrument is unique amongst the VLTI instruments, in that it is effectively two interferometers in one. PRIMA will take data from two sources on the sky simultaneously: the brighter source can be used for tracking, allowing the interferometer to "stare" at the fainter source for longer than is now possible with conventional interferometers. Although there have been earlier pathfinder experiments to test this technique, PRIMA represents the first facility

  3. Permafrost Active Layer Seismic Interferometry Experiment (PALSIE).

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Knox, Hunter Anne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); James, Stephanie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lee, Rebekah [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cole, Chris [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    We present findings from a novel field experiment conducted at Poker Flat Research Range in Fairbanks, Alaska that was designed to monitor changes in active layer thickness in real time. Results are derived primarily from seismic data streaming from seven Nanometric Trillium Posthole seismometers directly buried in the upper section of the permafrost. The data were evaluated using two analysis methods: Horizontal to Vertical Spectral Ratio (HVSR) and ambient noise seismic interferometry. Results from the HVSR conclusively illustrated the method's effectiveness at determining the active layer's thickness with a single station. Investigations with the multi-station method (ambient noise seismic interferometry) are continuing at the University of Florida and have not yet conclusively determined active layer thickness changes. Further work continues with the Bureau of Land Management (BLM) to determine if the ground based measurements can constrain satellite imagery, which provide measurements on a much larger spatial scale.

  4. Joint Multi-baseline SAR Interferometry

    Directory of Open Access Journals (Sweden)

    S. Tebaldini

    2005-12-01

    Full Text Available We propose a technique to provide interferometry by combining multiple images of the same area. This technique differs from the multi-baseline approach in literature as (a it exploits all the images simultaneously, (b it performs a spectral shift preprocessing to remove most of the decorrelation, and (c it exploits distributed targets. The technique is mainly intended for DEM generation at centimetric accuracy, as well as for differential interferometry. The problem is framed in the contest of single-input multiple-output (SIMO channel estimation via the cross-relations (CR technique and the resulting algorithm provides significant improvements with respect to conventional approaches based either on independent analysis of single interferograms or multi-baselines phase analysis of single pixels of current literature, for those targets that are correlated in all the images, like for long-term coherent areas, or for acquisitions taken with a short revisit time (as those gathered with future satellite constellations.

  5. Kinetic Titration Series with Biolayer Interferometry

    Science.gov (United States)

    Frenzel, Daniel; Willbold, Dieter

    2014-01-01

    Biolayer interferometry is a method to analyze protein interactions in real-time. In this study, we illustrate the usefulness to quantitatively analyze high affinity protein ligand interactions employing a kinetic titration series for characterizing the interactions between two pairs of interaction patterns, in particular immunoglobulin G and protein G B1 as well as scFv IC16 and amyloid beta (1–42). Kinetic titration series are commonly used in surface plasmon resonance and involve sequential injections of analyte over a desired concentration range on a single ligand coated sensor chip without waiting for complete dissociation between the injections. We show that applying this method to biolayer interferometry is straightforward and i) circumvents problems in data evaluation caused by unavoidable sensor differences, ii) saves resources and iii) increases throughput if screening a multitude of different analyte/ligand combinations. PMID:25229647

  6. Optical interferometry for biology and medicine

    CERN Document Server

    Nolte, David D

    2012-01-01

    This book presents the fundamental physics of optical interferometry as applied to biophysical, biological and medical research. Interference is at the core of many types of optical detection and is a powerful probe of cellular and tissue structure in interfererence microscopy and in optical coherence tomography. It is also the root cause of speckle and other imaging artefacts that limit range and resolution. For biosensor applications, the inherent sensitivity of interferometry enables ultrasensitive detection of molecules in biological samples for medical diagnostics. In this book, emphasis is placed on the physics of light scattering, beginning with the molecular origins of refraction as light propagates through matter, and then treating the stochastic nature of random fields that ultimately dominate optical imaging in cells and tissue. The physics of partial coherence plays a central role in the text, with a focus on coherence detection techniques that allow information to be selectively detected out of ...

  7. Fabry-Perot interferometry: astronomical applications

    International Nuclear Information System (INIS)

    Pismis, P.

    1982-01-01

    Some properties of the interference of light are presented with emphasis on interferometry by means of a Fabry-Perot etalon. The application of the etalon with a focal reducer to astronomical problems is discussed related in particular to the determination of radial velocities of extended emission objects, in galactic and extragalactic nebulae. Mention is also made of the work carried out in Mexico in this field as well as of developments under way. (author)

  8. Laser interferometry for the Big Bang Observer

    International Nuclear Information System (INIS)

    Harry, Gregory M; Fritschel, Peter; Shaddock, Daniel A; Folkner, William; Phinney, E Sterl

    2006-01-01

    The Big Bang Observer is a proposed space-based gravitational-wave detector intended as a follow on mission to the Laser Interferometer Space Antenna (LISA). It is designed to detect the stochastic background of gravitational waves from the early universe. We discuss how the interferometry can be arranged between three spacecraft for this mission and what research and development on key technologies are necessary to realize this scheme

  9. Refining molecular potentials using atom interferometry

    International Nuclear Information System (INIS)

    Forrey, R.C.; Kharchenko, V.; Dalgarno, A.; You, L.

    1997-01-01

    We present a theoretical study of the index of refraction of argon for the propagation of sodium matter waves. The sensitivity of the index of refraction to the details of the molecular potential curve is analyzed. Our calculations reveal velocity-dependent oscillations in the index of refraction that may be detectable, particularly at low temperatures, in atom interferometry measurements. A procedure for refining molecular potential curves is outlined. copyright 1997 The American Physical Society

  10. Monitoring civil infrastructure using satellite radar interferometry

    OpenAIRE

    Chang, L.

    2015-01-01

    Satellite radar interferometry (InSAR) is a precise and efficient technique to monitor deformation on Earth with millimeter precision. Most InSAR applications focus on geophysical phenomena, such as earthquakes, volcanoes, or subsidence. Monitoring civil infrastructure with InSAR is relatively new, with potential for operational applications, but currently not exploited to full advantage. Here we investigate how to optimally assess and monitor the structural health of civil infrastructure usi...

  11. Laser interferometry for the Big Bang Observer

    OpenAIRE

    Harry, Gregory M.; Fritschel, Peter; Shaddock, Daniel A.; Folkner, William; Phinney, E. Sterl

    2006-01-01

    The Big Bang Observer is a proposed space-based gravitational-wave detector intended as a follow on mission to the Laser Interferometer Space Antenna (LISA). It is designed to detect the stochastic background of gravitational waves from the early universe. We discuss how the interferometry can be arranged between three spacecraft for this mission and what research and development on key technologies are necessary to realize this scheme.

  12. Laser interferometry for the Big Bang Observer

    Energy Technology Data Exchange (ETDEWEB)

    Harry, Gregory M [LIGO Laboratory, Massachusetts Institute of Technology, NW17-161, Cambridge, MA 02139 (United States); Fritschel, Peter [LIGO Laboratory, Massachusetts Institute of Technology, NW17-161, Cambridge, MA 02139 (United States); Shaddock, Daniel A [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Folkner, William [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Phinney, E Sterl [California Institute of Technology, Pasadena, CA 91125 (United States)

    2006-08-07

    The Big Bang Observer is a proposed space-based gravitational-wave detector intended as a follow on mission to the Laser Interferometer Space Antenna (LISA). It is designed to detect the stochastic background of gravitational waves from the early universe. We discuss how the interferometry can be arranged between three spacecraft for this mission and what research and development on key technologies are necessary to realize this scheme.

  13. Interferometry and synthesis in radio astronomy

    CERN Document Server

    Thompson, A Richard; Swenson Jr , George W

    2017-01-01

    This book is open access under a CC BY-NC 4.0 license. The third edition of this indispensable book in radio interferometry provides extensive updates to the second edition, including results and technical advances from the past decade; discussion of arrays that now span the full range of the radio part of the electromagnetic spectrum observable from the ground, 10 MHz to 1 THz; an analysis of factors that affect array speed; and an expanded discussion of digital signal-processing techniques and of scintillation phenomena and the effects of atmospheric water vapor on image distortion, among many other topics. With its comprehensiveness and detailed exposition of all aspects of the theory and practice of radio interferometry and synthesis imaging, this book has established itself as a standard reference in the field. It begins with an overview of the basic principles of radio astronomy, a short history of the development of radio interferometry, and an elementary discussion of the operation of an interferomete...

  14. Comparing Laser Interferometry and Atom Interferometry Approaches to Space-Based Gravitational-Wave Measurement

    Science.gov (United States)

    Baker, John; Thorpe, Ira

    2012-01-01

    Thoroughly studied classic space-based gravitational-wave missions concepts such as the Laser Interferometer Space Antenna (LISA) are based on laser-interferometry techniques. Ongoing developments in atom-interferometry techniques have spurred recently proposed alternative mission concepts. These different approaches can be understood on a common footing. We present an comparative analysis of how each type of instrument responds to some of the noise sources which may limiting gravitational-wave mission concepts. Sensitivity to laser frequency instability is essentially the same for either approach. Spacecraft acceleration reference stability sensitivities are different, allowing smaller spacecraft separations in the atom interferometry approach, but acceleration noise requirements are nonetheless similar. Each approach has distinct additional measurement noise issues.

  15. Quantum Interferometry in Phase Space Theory and Applications

    CERN Document Server

    Suda, Martin

    2006-01-01

    Quantum Interferometry in Phase Space is primarily concerned with quantum-mechanical distribution functions and their applications in quantum optics and neutron interferometry. In the first part of the book, the author describes the phase-space representation of quantum optical phenomena such as coherent and squeezed states. Applications to interferometry, e.g. in beam splitters and fiber networks, are also presented. In the second part of the book, the theoretical formalism is applied to neutron interferometry, including the dynamical theory of diffraction, coherence properties of superposed beams, and dephasing effects.

  16. Validating Laser-Induced Birefringence Theory with Plasma Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Cecilia [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cornell Univ., Ithaca, NY (United States)

    2015-09-02

    Intense laser beams crossing paths in plasma is theorized to induce birefringence in the medium, resulting from density and refractive index modulations that affect the polarization of incoming light. The goal of the associated experiment, conducted on Janus at Lawrence Livermore’s Jupiter Laser Facility, was to create a tunable laser-plasma waveplate to verify the relationship between dephasing angle and beam intensity, plasma density, plasma temperature, and interaction length. Interferometry analysis of the plasma channel was performed to obtain a density map and to constrain temperature measured from Thomson scattering. Various analysis techniques, including Fast Fourier transform (FFT) and two variations of fringe-counting, were tried because interferograms captured in this experiment contained unusual features such as fringe discontinuity at channel edges, saddle points, and islands. The chosen method is flexible, semi-automated, and uses a fringe tracking algorithm on a reduced image of pre-traced synthetic fringes. Ultimately, a maximum dephasing angle of 49.6° was achieved using a 1200 μm interaction length, and the experimental results appear to agree with predictions.

  17. An imaging interferometry capability for the EISCAT Svalbard Radar

    Directory of Open Access Journals (Sweden)

    T. Grydeland

    2005-01-01

    Full Text Available Interferometric imaging (aperture synthesis imaging is a technique used by radio astronomers to achieve angular resolution that far surpasses what is possible with a single large aperture. A similar technique has been used for radar imaging studies of equatorial ionospheric phenomena at the Jicamarca Radio Observatory. We present plans for adding an interferometric imaging capability to the EISCAT Svalbard Radar (ESR, a capability which will contribute significantly to several areas of active research, including naturally and artificially enhanced ion-acoustic echoes and their detailed relation in space and time to optical phenomena, polar mesospheric summer echoes (PMSE, and meteor studies. Interferometry using the two antennas of the ESR has demonstrated the existence of extremely narrow, field-aligned scattering structures, but having only a single baseline is a severe limitation for such studies. Building additional IS-class antennas at the ESR is not a trivial task. However, the very high scattering levels in enhanced ion-acoustic echoes and PMSE means that a passive receiver antenna of more modest gain should still be capable of detecting these echoes. In this paper we present simulations of what an imaging interferometer will be capable of observing for different antenna configurations and brightness distributions, under ideal conditions, using two different image inversion algorithms. We also discuss different antenna and receiver technologies.

  18. An imaging interferometry capability for the EISCAT Svalbard Radar

    Directory of Open Access Journals (Sweden)

    T. Grydeland

    2005-01-01

    Full Text Available Interferometric imaging (aperture synthesis imaging is a technique used by radio astronomers to achieve angular resolution that far surpasses what is possible with a single large aperture. A similar technique has been used for radar imaging studies of equatorial ionospheric phenomena at the Jicamarca Radio Observatory. We present plans for adding an interferometric imaging capability to the EISCAT Svalbard Radar (ESR, a capability which will contribute significantly to several areas of active research, including naturally and artificially enhanced ion-acoustic echoes and their detailed relation in space and time to optical phenomena, polar mesospheric summer echoes (PMSE, and meteor studies.

    Interferometry using the two antennas of the ESR has demonstrated the existence of extremely narrow, field-aligned scattering structures, but having only a single baseline is a severe limitation for such studies. Building additional IS-class antennas at the ESR is not a trivial task. However, the very high scattering levels in enhanced ion-acoustic echoes and PMSE means that a passive receiver antenna of more modest gain should still be capable of detecting these echoes.

    In this paper we present simulations of what an imaging interferometer will be capable of observing for different antenna configurations and brightness distributions, under ideal conditions, using two different image inversion algorithms. We also discuss different antenna and receiver technologies.

  19. Development of a Multi-Point Microwave Interferometry (MPMI) Method

    Energy Technology Data Exchange (ETDEWEB)

    Specht, Paul Elliott [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cooper, Marcia A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jilek, Brook Anton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    A multi-point microwave interferometer (MPMI) concept was developed for non-invasively tracking a shock, reaction, or detonation front in energetic media. Initially, a single-point, heterodyne microwave interferometry capability was established. The design, construction, and verification of the single-point interferometer provided a knowledge base for the creation of the MPMI concept. The MPMI concept uses an electro-optic (EO) crystal to impart a time-varying phase lag onto a laser at the microwave frequency. Polarization optics converts this phase lag into an amplitude modulation, which is analyzed in a heterodyne interfer- ometer to detect Doppler shifts in the microwave frequency. A version of the MPMI was constructed to experimentally measure the frequency of a microwave source through the EO modulation of a laser. The successful extraction of the microwave frequency proved the underlying physical concept of the MPMI design, and highlighted the challenges associated with the longer microwave wavelength. The frequency measurements made with the current equipment contained too much uncertainty for an accurate velocity measurement. Potential alterations to the current construction are presented to improve the quality of the measured signal and enable multiple accurate velocity measurements.

  20. Forest canopy height estimation using double-frequency repeat pass interferometry

    Science.gov (United States)

    Karamvasis, Kleanthis; Karathanassi, Vassilia

    2015-06-01

    In recent years, many efforts have been made in order to assess forest stand parameters from remote sensing data, as a mean to estimate the above-ground carbon stock of forests in the context of the Kyoto protocol. Synthetic aperture radar interferometry (InSAR) techniques have gained traction in last decade as a viable technology for vegetation parameter estimation. Many works have shown that forest canopy height, which is a critical parameter for quantifying the terrestrial carbon cycle, can be estimated with InSAR. However, research is still needed to understand further the interaction of SAR signals with forest canopy and to develop an operational method for forestry applications. This work discusses the use of repeat pass interferometry with ALOS PALSAR (L band) HH polarized and COSMO Skymed (X band) HH polarized acquisitions over the Taxiarchis forest (Chalkidiki, Greece), in order to produce accurate digital elevation models (DEMs) and estimate canopy height with interferometric processing. The effect of wavelength-dependent penetration depth into the canopy is known to be strong, and could potentially lead to forest canopy height mapping using dual-wavelength SAR interferometry at X- and L-band. The method is based on scattering phase center separation at different wavelengths. It involves the generation of a terrain elevation model underneath the forest canopy from repeat-pass L-band InSAR data as well as the generation of a canopy surface elevation model from repeat pass X-band InSAR data. The terrain model is then used to remove the terrain component from the repeat pass interferometric X-band elevation model, so as to enable the forest canopy height estimation. The canopy height results were compared to a field survey with 6.9 m root mean square error (RMSE). The effects of vegetation characteristics, SAR incidence angle and view geometry, and terrain slope on the accuracy of the results have also been studied in this work.

  1. Frequency domain interferometry mode observations of PMSE using the EISCAT VHF radar

    Directory of Open Access Journals (Sweden)

    P. B. Chilson

    2000-12-01

    Full Text Available During the summer of 1997 investigations into the nature of polar mesosphere summer echoes (PMSE were conducted using the European incoherent scatter (EISCAT VHF radar in Norway. The radar was operated in a frequency domain interferometry (FDI mode over a period of two weeks to study the frequency coherence of the returned radar signals. The operating frequencies of the radar were 224.0 and 224.6 MHz. We present the first results from the experiment by discussing two 4-h intervals of data collected over two consecutive nights. During the first of the two days an enhancement of the FDI coherence, which indicates the presence of distinct scattering layers, was found to follow the lower boundary of the PMSE. Indeed, it is not unusual to observe that the coherence values are peaked around the heights corresponding to both the lower- and upper-most boundaries of the PMSE layer and sublayers. A Kelvin-Helmholtz mechanism is offered as one possible explanation for the layering structure. Additionally, our analysis using range-time-pseudocolor plots of signal-to-noise ratios, spectrograms of Doppler velocity, and estimates of the positions of individual scattering layers is shown to be consistent with the proposition that upwardly propagating gravity waves can become steepened near the mesopause.Key words: Ionosphere (polar ionosphere · Meteorology and Atmospheric Dynamics (middle atmosphere dynamics · Radio Science (Interferometry

  2. Frequency domain interferometry mode observations of PMSE using the EISCAT VHF radar

    Directory of Open Access Journals (Sweden)

    P. B. Chilson

    Full Text Available During the summer of 1997 investigations into the nature of polar mesosphere summer echoes (PMSE were conducted using the European incoherent scatter (EISCAT VHF radar in Norway. The radar was operated in a frequency domain interferometry (FDI mode over a period of two weeks to study the frequency coherence of the returned radar signals. The operating frequencies of the radar were 224.0 and 224.6 MHz. We present the first results from the experiment by discussing two 4-h intervals of data collected over two consecutive nights. During the first of the two days an enhancement of the FDI coherence, which indicates the presence of distinct scattering layers, was found to follow the lower boundary of the PMSE. Indeed, it is not unusual to observe that the coherence values are peaked around the heights corresponding to both the lower- and upper-most boundaries of the PMSE layer and sublayers. A Kelvin-Helmholtz mechanism is offered as one possible explanation for the layering structure. Additionally, our analysis using range-time-pseudocolor plots of signal-to-noise ratios, spectrograms of Doppler velocity, and estimates of the positions of individual scattering layers is shown to be consistent with the proposition that upwardly propagating gravity waves can become steepened near the mesopause.

    Key words: Ionosphere (polar ionosphere · Meteorology and Atmospheric Dynamics (middle atmosphere dynamics · Radio Science (Interferometry

  3. Self-calibration: an efficient method to control systematic effects in bolometric interferometry

    Science.gov (United States)

    Bigot-Sazy, M.-A.; Charlassier, R.; Hamilton, J.-Ch.; Kaplan, J.; Zahariade, G.

    2013-02-01

    Context. The QUBIC collaboration is building a bolometric interferometer dedicated to the detection of B-mode polarization fluctuations in the cosmic microwave background. Aims: We introduce a self-calibration procedure related to those used in radio-interferometry to control a wide range of instrumental systematic errors in polarization-sensitive instruments. Methods: This procedure takes advantage of the need for measurements on redundant baselines to match each other exactly in the absence of systematic effects. For a given systematic error model, measuring each baseline independently therefore allows writing a system of nonlinear equations whose unknowns are the systematic error model parameters (gains and couplings of Jones matrices, for instance). Results: We give the mathematical basis of the self-calibration. We implement this method numerically in the context of bolometric interferometry. We show that, for large enough arrays of horns, the nonlinear system can be solved numerically using a standard nonlinear least-squares fitting and that the accuracy achievable on systematic effects is only limited by the time spent on the calibration mode for each baseline apart from the validity of the systematic error model.

  4. Scanning White light interferometry: calibration and application to roughness assesment

    DEFF Research Database (Denmark)

    Bariani, Paolo

    This report refers to an experimental investigation recently completed. The aim was to gain some knowledge of the application of white light interferometry to surface metrology. The following issues were addressed by the present work: • How a white light interferometry microscope works, what...

  5. Powertrain engineering using holographic/electronic speckle pattern interferometry

    Science.gov (United States)

    Chen, Fang; Marchi, Mitchell M.; Allen, Thomas E.

    2002-06-01

    Novel applications of computer aided holographic interferometry and electronic speckle pattern interferometry in automotive powertrain engineering are presented. Four applications are described: engine manifold/cylinder head interface deformation measurement, engine camcover strain analysis, throttle bore deformation measurement, and alternator modal characterization.

  6. Method and device for carrying out speckle interferometry

    NARCIS (Netherlands)

    Somers, P.A.A.

    2005-01-01

    Device and method for obtaining a series of interference patterns from an interferometry device, comprising processing means (21) that are connected to detection means (2) of the interferometry device (1). The processing means (21) comprise computing means (22) and memory means (23) connected to the

  7. Atom Interferometry for Fundamental Physics and Gravity Measurements in Space

    Science.gov (United States)

    Kohel, James M.

    2012-01-01

    Laser-cooled atoms are used as freefall test masses. The gravitational acceleration on atoms is measured by atom-wave interferometry. The fundamental concept behind atom interferometry is the quantum mechanical particle-wave duality. One can exploit the wave-like nature of atoms to construct an atom interferometer based on matter waves analogous to laser interferometers.

  8. Fabry-Perot interferometry for microplasma diagnostics

    International Nuclear Information System (INIS)

    Hojo, H.; Mase, A.

    2006-01-01

    A new method for determining the electron density of a thin plasma by means of Fabry-Perot interferometry is proposed. The interferometer consists of two plasma layers and dielectric material surrounded by two plasma layers. The transmittance of electromagnetic waves across the interferometer is calculated, and Fabry-Perot resonances are demonstrated. It is shown that the electron density can be determined from the measurement of the Fabry-Perot resonance frequencies. This method can also be applied to the measurement of conduction electron density in semiconductor films

  9. Ten Years of Speckle Interferometry at SOAR

    Science.gov (United States)

    Tokovinin, Andrei

    2018-03-01

    Since 2007, close binary and multiple stars are observed by speckle interferometry at the 4.1 m Southern Astrophysical Research (SOAR) telescope. The HRCam instrument, observing strategy and planning, data processing and calibration methods, developed and improved during ten years, are presented here in a concise way. Thousands of binary stars were measured with diffraction-limited resolution (29 mas at 540 nm wavelength) and a high accuracy reaching 1 mas; 200 new pairs or subsystems were discovered. To date, HRCam has performed over 11,000 observations with a high efficiency (up to 300 stars per night). An overview of the main results delivered by this instrument is given.

  10. Measuring Interfacial Polymerization Kinetics Using Microfluidic Interferometry.

    Science.gov (United States)

    Nowbahar, Arash; Mansard, Vincent; Mecca, Jodi M; Paul, Mou; Arrowood, Tina; Squires, Todd M

    2018-03-07

    A range of academic and industrial fields exploit interfacial polymerization in producing fibers, capsules, and films. Although widely used, measurements of reaction kinetics remain challenging and rarely reported, due to film thinness and reaction rapidity. Here, polyamide film formation is studied using microfluidic interferometry, measuring monomer concentration profiles near the interface during the reaction. Our results reveal that the reaction is initially controlled by a reaction-diffusion boundary layer within the organic phase, which allows the first measurements of the rate constant for this system.

  11. Probing dark energy with atom interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Burrage, Clare; Copeland, Edmund J. [School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD (United Kingdom); Hinds, E.A., E-mail: Clare.Burrage@nottingham.ac.uk, E-mail: Edmund.Copeland@nottingham.ac.uk, E-mail: Ed.Hinds@imperial.ac.uk [Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom)

    2015-03-01

    Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.

  12. Probing dark energy with atom interferometry

    International Nuclear Information System (INIS)

    Burrage, Clare; Copeland, Edmund J.; Hinds, E.A.

    2015-01-01

    Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry

  13. Frequency scanning interferometry for CLIC component fiducialisation

    CERN Document Server

    Kamugasa, Solomon William; Mainaud Durand, Helene; CERN. Geneva. ATS Department

    2016-01-01

    We present a strategy for the fiducialisation of CLIC’s Main Beam Quadrupole (MBQ) magnets using Frequency Scanning Interferometry (FSI). We have developed complementary device for a commercial FSI system to enable coordinate determination via multilateration. Using spherical high index glass retroreflectors with a wide acceptance angle, we optimise the geometry of measurement stations with respect to fiducials -- thus improving the precision of coordinates. We demonstrate through simulations that the 10 μm uncertainty required in the vertical and lateral axes for the fiducialisation of the MBQ can be attained using FSI multilateration.

  14. Diffusion in solids with holographic interferometry

    Science.gov (United States)

    Liu, Dingyu

    1996-12-01

    It is of great importance for the formation of p-n junction in semiconductors by penetrating some impurities through the depth near the surface, so it has long been paid attention to control the concentration distribution of impurities during the diffusion process. In recent years, ionic carburizing, and ion bombardment penetration etc. for the treatment of metal surface have also attracted by material sciences. It requires that the diffusion depth and the diffusion time of the impurities should be under precise control. Different methods, such as the method of radioisotopic detection and the method of chemical analysis have been adopted, however, the reports of different workers are very different, especially in the real time measurement, so, finding new method is never ending. In 1984, H. Fenichel have performed experiments on the solutions of table salt and sugar with the method of holographic interferometry. As for metals which are opaque for the visible light, but they become transparent by making them into a very thin film so that, in principle, the diffusion of atoms within a film is capable of measure by holographic interferometry. Alternatively, the electromagnetic waves within 1 - 70 micrometers wavelengths may be utilized, some materials, such as high purified germanium and silicon are good materials for infrared transmission. Some fluorides of alkaline-earth metals have high transmittance in the range of 1 - 8 micrometers , the concentration of impurities in the semiconductor and metal surface treatment are of 1015 - 1020 atoms per cubic cm, which is capable of detection.

  15. Astronomical optical interferometry, II: Astrophysical results

    Directory of Open Access Journals (Sweden)

    Jankov S.

    2011-01-01

    Full Text Available Optical interferometry is entering a new age with several ground- based long-baseline observatories now making observations of unprecedented spatial resolution. Based on a great leap forward in the quality and quantity of interferometric data, the astrophysical applications are not limited anymore to classical subjects, such as determination of fundamental properties of stars; namely, their effective temperatures, radii, luminosities and masses, but the present rapid development in this field allowed to move to a situation where optical interferometry is a general tool in studies of many astrophysical phenomena. Particularly, the advent of long-baseline interferometers making use of very large pupils has opened the way to faint objects science and first results on extragalactic objects have made it a reality. The first decade of XXI century is also remarkable for aperture synthesis in the visual and near-infrared wavelength regimes, which provided image reconstructions from stellar surfaces to Active Galactic Nuclei. Here I review the numerous astrophysical results obtained up to date, except for binary and multiple stars milliarcsecond astrometry, which should be a subject of an independent detailed review, taking into account its importance and expected results at microarcsecond precision level. To the results obtained with currently available interferometers, I associate the adopted instrumental settings in order to provide a guide for potential users concerning the appropriate instruments which can be used to obtain the desired astrophysical information.

  16. Observations of binary stars by speckle interferometry

    International Nuclear Information System (INIS)

    Morgan, B.L.; Beckmann, G.K.; Scaddan, R.J.

    1980-01-01

    This is the second paper in a series describing observations of binary stars using the technique of speckle interferometry. Observations were made using the 2.5-m Isaac Newton Telescope and the 1-m telescope of the Royal Greenwich Observatory and the 1.9-m telescope of the South African Astronomical Observatory. The classical Rayleigh diffraction limits are 0.050 arcsec for the 2.5-m telescope, 0.065 arcsec for the 1.9-m telescope and 0.125 arcsec for the 1-m telescope, at a wavelength of 500 nm. The results of 29 measurements of 26 objects are presented. The objects include long period spectroscopic binaries from the 6th Catalogue of Batten, close visual binary systems from the 3rd Catalogue of Finsen and Worley and variable stars. Nine of the objects have not been previously resolved by speckle interferometry. New members are detected in the systems β Cep, p Vel and iota UMa. (author)

  17. GLINT. Gravitational-wave laser INterferometry triangle

    Science.gov (United States)

    Aria, Shafa; Azevedo, Rui; Burow, Rick; Cahill, Fiachra; Ducheckova, Lada; Holroyd, Alexa; Huarcaya, Victor; Järvelä, Emilia; Koßagk, Martin; Moeckel, Chris; Rodriguez, Ana; Royer, Fabien; Sypniewski, Richard; Vittori, Edoardo; Yttergren, Madeleine

    2017-11-01

    When the universe was roughly one billion years old, supermassive black holes (103-106 solar masses) already existed. The occurrence of supermassive black holes on such short time scales are poorly understood in terms of their physical or evolutionary processes. Our current understanding is limited by the lack of observational data due the limits of electromagnetic radiation. Gravitational waves as predicted by the theory of general relativity have provided us with the means to probe deeper into the history of the universe. During the ESA Alpach Summer School of 2015, a group of science and engineering students devised GLINT (Gravitational-wave Laser INterferometry Triangle), a space mission concept capable of measuring gravitational waves emitted by black holes that have formed at the early periods after the big bang. Morespecifically at redshifts of 15 big bang) in the frequency range 0.01 - 1 Hz. GLINT design strain sensitivity of 5× 10^{-24} 1/√ { {Hz}} will theoretically allow the study of early black holes formations as well as merging events and collapses. The laser interferometry, the technology used for measuring gravitational waves, monitors the separation of test masses in free-fall, where a change of separation indicates the passage of a gravitational wave. The test masses will be shielded from disturbing forces in a constellation of three geocentric orbiting satellites.

  18. 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

  19. Monitoring gas reservoirs by seismic interferometry

    Science.gov (United States)

    Grigoli, Francesco; Cesca, Simone; Sens-Schoenfelder, Christoph; Priolo, Enrico

    2014-05-01

    Ambient seismic noise can be used to image spatial anomalies in the subsurface, without the need of recordings from seismic sources, such as earthquakes or explosions. Furthermore, the temporal variation of ambient seismic noise's can be used to infer temporal changes of the seismic velocities in the investigated medium. Such temporal variations can reflect changes of several physical properties/conditions in the medium. For example, they may be consequence of stress changes, variation of hydrogeological parameters, pore pressure and saturation changes due to fluid injection or extraction. Passive image interferometry allows to continuously monitor small temporal changes of seismic velocities in the subsurface, making it a suitable tool to monitor time-variant systems such as oil and gas reservoirs or volcanic environments. The technique does not require recordings from seismic sources in the classical sense, but is based on the processing of noise records. Moreover, it requires only data from one or two seismic stations, their locations constraining the sampled target area. Here we apply passive image interferometry to monitor a gas storage reservoir in northern Italy. The Collalto field (Northern Italy) is a depleted gas reservoir located at 1500 m depth, now used as a gas storage facility. The reservoir experience a significant temporal variation in the amount of stored gas: the injection phases mainly occur in the summer, while the extraction take place mostly in winter. In order to monitor induced seismicity related to gas storage operations, a seismic network (the Collalto Seismic Network) has been deployed in 2011. The Collalto Seismic Network is composed by 10 broadband stations, deployed within an area of about 20 km x 20 km, and provides high-quality continuous data since January 1st, 2012. In this work we present preliminary results from ambient noise interferometry using a two-months sample of continuous seismic data, i.e. from October 1st, 2012, to the

  20. 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

  1. 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...

  2. Plasma diagnostics by resonant interferometry and holography

    Energy Technology Data Exchange (ETDEWEB)

    Dreiden, G.V.; Zaidel, A.N.; Ostrovskaya, G.V.; Ostrovskii, Yu.I.; Pobedonostseva, N.A.; Tanin, L.V.; Filippov, V.N.; Shedova, E.N.

    1975-01-01

    The methods of resonant interferometry and holography are discussed, and their ranges of applicability are estimated. Resonant methods enjoy a high sensitivity and a high selectivity in comparison with ordinary interferometric and holographic methods. Their primary field of application is with dense plasmas, although in individual cases it is possible to determine atomic densities down to N/sub a/ = 10/sup 9/ cm/sup -3/ and below. For a plasma with N/sub a/ = 10/sup 18/-10/sup 19/ cm/sup -3/ the minimum detectable atomic density is about N/sub a/ = 10/sup 14/ cm/sup -3/. The specific requirements on light sources and methods for studying them are described. The capabilities of these methods are demonstrated for the cases of potassium, sodium, lithium, and hydrogen plasmas; the atomic and electron densities are determined, and the plasma dynamics is studied.

  3. Atom interferometry using a shaken optical lattice

    Science.gov (United States)

    Weidner, C. A.; Yu, Hoon; Kosloff, Ronnie; Anderson, Dana Z.

    2017-04-01

    We introduce shaken lattice interferometry with atoms trapped in a one-dimensional optical lattice. By phase modulating (shaking) the lattice, we control the momentum state of the atoms. Through a sequence of shaking functions, the atoms undergo an interferometer sequence of splitting, propagation, reflection, reverse propagation, and recombination. Each shaking function in the sequence is optimized with a genetic algorithm to achieve the desired momentum state transitions. As with conventional atom interferometers, the sensitivity of the shaken lattice interferometer increases with interrogation time. The shaken lattice interferometer may also be optimized to sense signals of interest while rejecting others, such as the measurement of an ac inertial signal in the presence of an unwanted dc signal.

  4. Compressed-sensing wavenumber-scanning interferometry

    Science.gov (United States)

    Bai, Yulei; Zhou, Yanzhou; He, Zhaoshui; Ye, Shuangli; Dong, Bo; Xie, Shengli

    2018-01-01

    The Fourier transform (FT), the nonlinear least-squares algorithm (NLSA), and eigenvalue decomposition algorithm (EDA) are used to evaluate the phase field in depth-resolved wavenumber-scanning interferometry (DRWSI). However, because the wavenumber series of the laser's output is usually accompanied by nonlinearity and mode-hop, FT, NLSA, and EDA, which are only suitable for equidistant interference data, often lead to non-negligible phase errors. In this work, a compressed-sensing method for DRWSI (CS-DRWSI) is proposed to resolve this problem. By using the randomly spaced inverse Fourier matrix and solving the underdetermined equation in the wavenumber domain, CS-DRWSI determines the nonuniform sampling and spectral leakage of the interference spectrum. Furthermore, it can evaluate interference data without prior knowledge of the object. The experimental results show that CS-DRWSI improves the depth resolution and suppresses sidelobes. It can replace the FT as a standard algorithm for DRWSI.

  5. Active SU(1,1) atom interferometry

    Science.gov (United States)

    Linnemann, D.; Schulz, J.; Muessel, W.; Kunkel, P.; Prüfer, M.; Frölian, A.; Strobel, H.; Oberthaler, M. K.

    2017-12-01

    Active interferometers use amplifying elements for beam splitting and recombination. We experimentally implement such a device by using spin exchange in a Bose-Einstein condensate. The two interferometry modes are initially empty spin states that get spontaneously populated in the process of parametric amplification. This nonlinear mechanism scatters atoms into both modes in a pairwise fashion and generates a non-classical state. Finally, a matched second period of spin exchange is performed that nonlinearly amplifies the output signal and maps the phase onto readily detectable first moments. Depending on the accumulated phase this nonlinear readout can reverse the initial dynamics and deamplify the entangled state back to empty spin states. This sequence is described in the framework of SU(1,1) mode transformations and compared to the SU(2) angular momentum description of passive interferometers.

  6. Atom-surface potentials and atom interferometry

    International Nuclear Information System (INIS)

    Babb, J.F.

    1998-01-01

    Long-range atom-surface potentials characterize the physics of many actual systems and are now measurable spectroscopically in deflection of atomic beams in cavities or in reflection of atoms in atomic fountains. For a ground state, spherically symmetric atom the potential varies as -1/R 3 near the wall, where R is the atom-surface distance. For asymptotically large distances the potential is weaker and goes as -1/R 4 due to retardation arising from the finite speed of light. This diminished interaction can also be interpreted as a Casimir effect. The possibility of measuring atom-surface potentials using atomic interferometry is explored. The particular cases studied are the interactions of a ground-state alkali-metal atom and a dielectric or a conducting wall. Accurate descriptions of atom-surface potentials in theories of evanescent-wave atomic mirrors and evanescent wave-guided atoms are also discussed. (author)

  7. Edge effects in composites by moire interferometry

    Science.gov (United States)

    Czarnek, R.; Post, D.; Herakovich, C.

    1983-01-01

    The very high sensitivity of moire interferometry has permitted the present edge effect experiments to be conducted at a low average stress and strain level, assuring linear and elastic behavior in the composite material samples tested. Sensitivity corresponding to 2450 line/mm moire was achieved with a 0.408 micron/fringe. Simultaneous observations of the specimen face and edge displacement fields showed good fringe definition despite the 1-mm thickness of the specimens and the high gradients, and it is noted that the use of a carrier pattern and optical filtering was effective in even these conditions. Edge effects and dramatic displacement gradients were confirmed in angle-ply composite laminates.

  8. Externally Dispersed Interferometry for Precision Radial Velocimetry

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D J; Muterspaugh, M W; Edelstein, J; Lloyd, J; Herter, T; Feuerstein, W M; Muirhead, P; Wishnow, E

    2007-03-27

    Externally Dispersed Interferometry (EDI) is the series combination of a fixed-delay field-widened Michelson interferometer with a dispersive spectrograph. This combination boosts the spectrograph performance for both Doppler velocimetry and high resolution spectroscopy. The interferometer creates a periodic spectral comb that multiplies against the input spectrum to create moire fringes, which are recorded in combination with the regular spectrum. The moire pattern shifts in phase in response to a Doppler shift. Moire patterns are broader than the underlying spectral features and more easily survive spectrograph blurring and common distortions. Thus, the EDI technique allows lower resolution spectrographs having relaxed optical tolerances (and therefore higher throughput) to return high precision velocity measurements, which otherwise would be imprecise for the spectrograph alone.

  9. Forest biomass estimation from polarimetric SAR interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Mette, T.

    2007-07-01

    Polarimetric SAR interferometry (Pol-InSAR) is a radar remote sensing technique that allows extracting forest heights by means of model-based inversions. Forest biomass is closely related to forest height, and can be derived from it with allometric relations. This work investigates the combination of the two methods to estimate forest biomass from Pol-InSAR. It develops a concept for the use of height-biomass allometry, and outlines the Pol-InSAR height inversion. The methodology is validated against a set of forest inventory data and Pol-InSAR data at L-band of the test site Traunstein. The results allow drawing conclusions on the potential of Pol-InSAR forest biomass missions. (orig.)

  10. Multi-Axis Heterodyne Interferometry (MAHI)

    Science.gov (United States)

    Thorpe, James

    The detection and measurement of gravitational waves represents humanity’s next, and final, opportunity to open an entirely new spectrum with which to view the universe. The first steps of this process will likely take place later this decade when the second-generation ground-based instruments such as Advanced LIGO approach design sensitivity. While these events will be historic, it will take a space-based detector to access the milliHertz gravitational wave frequency band, a band that is rich in both number and variety of sources. The Laser Interferometer Space Antenna (LISA) concept has been developed over the past two decades in the US and Europe to provide access to this band. The European Space Agency recently selected The Gravitational Universe as the science theme for the 3rd Large-class mission in the Cosmic Visions Programme, with the assumption that a LISA-like instrument would be implemented for launch in 2034. NASA has expressed interest in partnering on this effort and the US community has made its own judgment on the scientific potential of a space-based gravitational wave observatory through the selection of LISA as the 3rd flagship mission in the 2010 Decadal Survey. Much of the effort has been in retiring risk for the unique technologies that comprise a gravitational wave detector. A prime focus of this effort is LISA Pathfinder (LPF), a dedicated technology demonstrator mission led by ESA with contributions from NASA and several member states. LPF’s primary objective is to validate drag-free flight as an approach to realizing an inertial reference mass. Along the way, several important technologies will be demonstrated, including picometer-level heterodyne interferometry. However, there are several important differences between the interferometry design for LISA and that for LPF. These mostly result from the fact that LISA interferometry involves multiple lasers on separate spacecraft whereas LPF can use a single laser on a single spacecraft

  11. Speckle interferometry of asteroids. I - 433 Eros

    Science.gov (United States)

    Drummond, J. D.; Cocke, W. J.; Hege, E. K.; Strittmatter, P. A.; Lambert, J. V.

    1985-01-01

    Analytical expressions are derived for the semimajor and semiminor axes and orientation angle of the ellipse projected by a triaxial asteroid, and the results are applied speckle-interferometry observations of the 433 Eros asteroid. The expressions were calculated as functions of the dimensions and pole of the body and of the asterocentric position of the earth and the sun. On the basis of the analytical expressions, the dimensions of 433 Eros are obtained. The light curve from December 18, 1981 is compared to the dimensions to obtain a geometric albedo of 0.156 (+ or - 0.010). A series of two-dimensional power spectra and autocorrelation functions for 433 Eros show that it is spinning in space.

  12. Application of Hybrid Along-Track Interferometry/Displaced Phase Center Antenna Method for Moving Human Target Detection in Forest Environments

    Science.gov (United States)

    2016-10-01

    Research Laboratory Application of Hybrid Along-Track Interferometry/Displaced Phase Center Antenna Method for Moving Human Target Detection...2 Fig. 2 GMTI-SAR images (hh-polarized) from hybrid ATI/DPCA method for scene in Fig. 1: a) with trees, moving human with variable...imaging and GMTI simultaneously, a hybrid ATI/DPCA method is exploited for moving human target detection in this work. The technique assumes the

  13. 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).

  14. Investigation of surface deformations by double exposure holographic interferometry

    International Nuclear Information System (INIS)

    Ecevit, F.N.; Guven, H.; Aydin, R.

    1990-01-01

    Surface deformations of rigid bodies produced by thermal as well as mechanical strains have been investigated using double-exposure holographic interferometry. The recorded interference fringes have been discussed qualitatively. (author). 9 refs, 4 figs

  15. Range Surveillance Using Radio Interferometry and TDOA Techniques Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation will utilize a small network of remote sensors to perform Radio Interferometry (RI) and Time Difference of Arrival (TDOA) techniques to...

  16. The digital holographic interferometry in resonant acoustic spectroscopy

    International Nuclear Information System (INIS)

    GAPONOV, V.E.; AZAMATOV, Z.T.; REDKORECHEV, V.I.; ISAEV, A.M.

    2014-01-01

    The opportunities of application of digital holographic interferometry method for studies of shapes of resonant modes in resonant acoustic spectroscopy are shown. The results of experimental measurements and analytical calculations are submitted. (authors)

  17. Observational Model for Precision Astrometry with the Space Interferometry Mission

    National Research Council Canada - National Science Library

    Turyshev, Slava G; Milman, Mark H

    2000-01-01

    The Space Interferometry Mission (SIM) is a space-based 10-m baseline Michelson optical interferometer operating in the visible waveband that is designed to achieve astrometric accuracy in the single digits of the microarcsecond domain...

  18. Using Optical Interferometry for GEO Satellites Imaging: An Update

    Science.gov (United States)

    2016-05-27

    Using Optical Interferometry for GEO satellites imaging: an update Sergio R. Restainoa,J. Thomas Armstronga, Ellyn K. Bainesa, Henrique R. Schmitta...of a geostationary satellite using the Navy Precision Optical Inter- ferometer (NPOI) during the glint season of March 2015. We succeeded in detecting...detection of a satellite . Keywords: geostationary satellites , optical interferometry, imaging, telescope arrays 1. INTRODUCTION Developing the ability to

  19. Pumped-Up SU(1,1) Interferometry.

    Science.gov (United States)

    Szigeti, Stuart S; Lewis-Swan, Robert J; Haine, Simon A

    2017-04-14

    Although SU(1,1) interferometry achieves Heisenberg-limited sensitivities, it suffers from one major drawback: Only those particles outcoupled from the pump mode contribute to the phase measurement. Since the number of particles outcoupled to these "side modes" is typically small, this limits the interferometer's absolute sensitivity. We propose an alternative "pumped-up" approach where all the input particles participate in the phase measurement and show how this can be implemented in spinor Bose-Einstein condensates and hybrid atom-light systems-both of which have experimentally realized SU(1,1) interferometry. We demonstrate that pumped-up schemes are capable of surpassing the shot-noise limit with respect to the total number of input particles and are never worse than conventional SU(1,1) interferometry. Finally, we show that pumped-up schemes continue to excel-both absolutely and in comparison to conventional SU(1,1) interferometry-in the presence of particle losses, poor particle-resolution detection, and noise on the relative phase difference between the two side modes. Pumped-up SU(1,1) interferometry therefore pushes the advantages of conventional SU(1,1) interferometry into the regime of high absolute sensitivity, which is a necessary condition for useful quantum-enhanced devices.

  20. Using Seismic Interferometry to Investigate Seismic Swarms

    Science.gov (United States)

    Matzel, E.; Morency, C.; Templeton, D. C.

    2017-12-01

    Seismicity provides a direct means of measuring the physical characteristics of active tectonic features such as fault zones. Hundreds of small earthquakes often occur along a fault during a seismic swarm. This seismicity helps define the tectonically active region. When processed using novel geophysical techniques, we can isolate the energy sensitive to the fault, itself. Here we focus on two methods of seismic interferometry, ambient noise correlation (ANC) and the virtual seismometer method (VSM). ANC is based on the observation that the Earth's background noise includes coherent energy, which can be recovered by observing over long time periods and allowing the incoherent energy to cancel out. The cross correlation of ambient noise between a pair of stations results in a waveform that is identical to the seismogram that would result if an impulsive source located at one of the stations was recorded at the other, the Green function (GF). The calculation of the GF is often stable after a few weeks of continuous data correlation, any perturbations to the GF after that point are directly related to changes in the subsurface and can be used for 4D monitoring.VSM is a style of seismic interferometry that provides fast, precise, high frequency estimates of the Green's function (GF) between earthquakes. VSM illuminates the subsurface precisely where the pressures are changing and has the potential to image the evolution of seismicity over time, including changes in the style of faulting. With hundreds of earthquakes, we can calculate thousands of waveforms. At the same time, VSM collapses the computational domain, often by 2-3 orders of magnitude. This allows us to do high frequency 3D modeling in the fault region. Using data from a swarm of earthquakes near the Salton Sea, we demonstrate the power of these techniques, illustrating our ability to scale from the far field, where sources are well separated, to the near field where their locations fall within each other

  1. 3D super-virtual refraction interferometry

    KAUST Repository

    Lu, Kai

    2014-08-05

    Super-virtual refraction interferometry enhances the signal-to-noise ratio of far-offset refractions. However, when applied to 3D cases, traditional 2D SVI suffers because the stationary positions of the source-receiver pairs might be any place along the recording plane, not just along a receiver line. Moreover, the effect of enhancing the SNR can be limited because of the limitations in the number of survey lines, irregular line geometries, and azimuthal range of arrivals. We have developed a 3D SVI method to overcome these problems. By integrating along the source or receiver lines, the cross-correlation or the convolution result of a trace pair with the source or receiver at the stationary position can be calculated without the requirement of knowing the stationary locations. In addition, the amplitudes of the cross-correlation and convolution results are largely strengthened by integration, which is helpful to further enhance the SNR. In this paper, both synthetic and field data examples are presented, demonstrating that the super-virtual refractions generated by our method have accurate traveltimes and much improved SNR.

  2. Laser Wakefield diagnostic using holographic longitudinal interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Volfbeyn, P.; Esarey, E.; Leemans, W.P.

    1999-03-26

    We propose a diagnostic technique for wakefield measurement in plasma channels. A new technique for plasma channel creation, the Ignitor Heater scheme was proposed and experimentally tested in hydrogen and nitrogen previously. It makes use of two laser pulses. The Ignitor, an ultrashort (sub 100 fs) laser pulse, is brought to a line focus using a cylindrical lens to ionize the gas. The Heater pulse (160 ps long) is used to heat the existing spark via in-verse Bremsstrahlung. The hydrodynamic shock expansion creates a partially evacuated plasma channel with a density minimum on axis. Such a channel has properties of an optical waveguide. This technique allows creation of plasma channels in low atomic number gases, such as hydrogen, which is of importance for guiding of highly intense laser pulses. Laser pulses injected into such plasma channels produce a plasma wake that has a phase velocity close to the speed of light. A discussion of plasma wake measurements, using a Longitudinal Interferometry Wakefield Diagnostic Based on Time Domain Rayleigh Refractometry with Holographic Inversion, will be presented.

  3. General Relativistic Effects in Atom Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, Savas; /Stanford U., Phys. Dept.; Graham, Peter W.; /SLAC /Stanford U., Phys. Dept.; Hogan, Jason M.; Kasevich, Mark A.; /Stanford U., Phys. Dept.

    2008-03-17

    Atom interferometry is now reaching sufficient precision to motivate laboratory tests of general relativity. We begin by explaining the non-relativistic calculation of the phase shift in an atom interferometer and deriving its range of validity. From this we develop a method for calculating the phase shift in general relativity. This formalism is then used to find the relativistic effects in an atom interferometer in a weak gravitational field for application to laboratory tests of general relativity. The potentially testable relativistic effects include the non-linear three-graviton coupling, the gravity of kinetic energy, and the falling of light. We propose experiments, one currently under construction, that could provide a test of the principle of equivalence to 1 part in 10{sup 15} (300 times better than the present limit), and general relativity at the 10% level, with many potential future improvements. We also consider applications to other metrics including the Lense-Thirring effect, the expansion of the universe, and preferred frame and location effects.

  4. White light interferometry applications in nanometrology

    Science.gov (United States)

    Damian, V. S.; Bojan, M.; Schiopu, P.; Iordache, I.; Ionita, B.; Apostol, D.

    2009-01-01

    Precise three-dimensional (3D) information is demanded by many new industries such as: semiconductor, photonics, MEMS, communications, microprocessing etc. [1, 2]. The problem is to select the proper measurement methods for material characteristics in the measurement field, from the point of view of the measurement accuracy and errors that can appear [1, 4, 3, 5]. There are several optical 3D measurements approaches, e.g.: triangulation, grating projection with phase shift, moiré with phase shift, confocal and (white light) interferometry (WLI) [2, 3]. They can measures: surface profile, roughness, step height, microstructure, and other surface parameters. The white light interferometers allows generally surface profiling with high accuracy with no phase ambiguity errors, making them more suitable for profiling stepped or discontinuous surfaces. WLI technique to determine the thickness of thin coating on reflective materials is very effective. One of the first techniques to utilize the short coherence of the white light source was the scanning interference microscope. There are on the market a variety of scanning white light interferometers. Measurement calibration is done using the short coherence feature of white light. Some of the presented applications in nanometrology are thin films thickness measurements of: carbons films on glass, metallic films on Silicon, ablated small holes diameter, and profiles of micro / nanostructure.

  5. Multifrequency perturbations in matter-wave interferometry

    Science.gov (United States)

    Günther, A.; Rembold, A.; Schütz, G.; Stibor, A.

    2015-11-01

    High-contrast matter-wave interferometry is essential in various fundamental quantum mechanical experiments as well as for technical applications. Thereby, contrast and sensitivity are typically reduced by decoherence and dephasing effects. While decoherence accounts for a general loss of quantum information in a system due to entanglement with the environment, dephasing is due to collective time-dependent external phase shifts, which can be related to temperature drifts, mechanical vibrations, and electromagnetic oscillations. In contrast to decoherence, dephasing can, in principle, be reversed. Here, we demonstrate in experiment and theory a method for the analysis and reduction of the influence of dephasing noise and perturbations consisting of several external frequencies in an electron interferometer. This technique uses the high spatial and temporal resolution of a delay-line detector to reveal and remove dephasing perturbations by second-order correlation analysis. It allows matter-wave experiments under perturbing laboratory conditions and can be applied, in principle, to electron, atom, ion, neutron, and molecule interferometers.

  6. Bounding the Higgs boson width through interferometry.

    Science.gov (United States)

    Dixon, Lance J; Li, Ye

    2013-09-13

    We study the change in the diphoton-invariant-mass distribution for Higgs boson decays to two photons, due to interference between the Higgs resonance in gluon fusion and the continuum background amplitude for gg→γγ. Previously, the apparent Higgs mass was found to shift by around 100 MeV in the standard model in the leading-order approximation, which may potentially be experimentally observable. We compute the next-to-leading-order QCD corrections to the apparent mass shift, which reduce it by about 40%. The apparent mass shift may provide a way to measure, or at least bound, the Higgs boson width at the Large Hadron Collider through "interferometry." We investigate how the shift depends on the Higgs width, in a model that maintains constant Higgs boson signal yields. At Higgs widths above 30 MeV, the mass shift is over 200 MeV and increases with the square root of the width. The apparent mass shift could be measured by comparing with the ZZ* channel, where the shift is much smaller. It might be possible to measure the shift more accurately by exploiting its strong dependence on the Higgs transverse momentum.

  7. High-Speed Interferometry Under Impacting Drops

    KAUST Repository

    Langley, Kenneth R.

    2017-08-31

    Over the last decade the rapid advances in high-speed video technology, have opened up to study many multi-phase fluid phenomena, which tend to occur most rapidly on the smallest length-scales. One of these is the entrapment of a small bubble under a drop impacting onto a solid surface. Here we have gone from simply observing the presence of the bubble to detailed imaging of the formation of a lubricating air-disc under the drop center and its subsequent contraction into the bubble. Imaging the full shape-evolution of the air-disc has required μm and sub-μs space and time resolutions. Time-resolved 200 ns interferometry with monochromatic light, has allowed us to follow individual fringes to obtain absolute air-layer thicknesses, based on the eventual contact with the solid. We can follow the evolution of the dimple shape as well as the compression of the gas. The improved imaging has also revealed new levels of detail, like the nature of the first contact which produces a ring of micro-bubbles, highlighting the influence of nanometric surface roughness. Finally, for impacts of ultra-viscous drops we see gliding on ~100 nm thick rarified gas layers, followed by extreme wetting at numerous random spots.

  8. From master slave interferometry to complex master slave interferometry: theoretical work

    Science.gov (United States)

    Rivet, Sylvain; Bradu, Adrian; Maria, Michael; Feuchter, Thomas; Leick, Lasse; Podoleanu, Adrian

    2018-03-01

    A general theoretical framework is described to obtain the advantages and the drawbacks of two novel Fourier Domain Optical Coherence Tomography (OCT) methods denoted as Master/Slave Interferometry (MSI) and its extension denoted as Complex Master/Slave Interferometry (CMSI). Instead of linearizing the digital data representing the channeled spectrum before a Fourier transform can be applied to it (as in OCT standard methods), channeled spectrum is decomposed on the basis of local oscillations. This replaces the need for linearization, generally time consuming, before any calculation of the depth profile in the range of interest. In this model two functions, g and h, are introduced. The function g describes the modulation chirp of the channeled spectrum signal due to nonlinearities in the decoding process from wavenumber to time. The function h describes the dispersion in the interferometer. The utilization of these two functions brings two major improvements to previous implementations of the MSI method. The paper details the steps to obtain the functions g and h, and represents the CMSI in a matrix formulation that enables to implement easily this method in LabVIEW by using parallel programming with multi-cores.

  9. Digital Double-Pulse Holographic Interferometry for Vibration Analysis

    Directory of Open Access Journals (Sweden)

    H.J. Tiziani

    1996-01-01

    Full Text Available Different arrangements for double-pulsed holographic and speckle interferometry for vibration analysis will be described. Experimental results obtained with films (classical holographic interferometry and CCD cameras (digital holographic interferometry as storage materials are presented. In digital holography, two separate holograms of an object under test are recorded within a few microseconds using a CCD camera and are stored in a frame grabber. The phases of the two reconstructed wave fields are calculated from the complex amplitudes. The deformation is obtained from the phase difference. In the case of electronic speckle pattern interferometry (or image plane hologram, the phase can be calculated by using the sinusoid-fitting method. In the case of digital holographic interferometry, the phase is obtained by digital reconstruction of the complex amplitudes of the wave fronts. Using three directions of illumination and one direction of observation, all the information necessary for the reconstruction of the 3-dimensional deformation vector can be recorded at the same time. Applications of the method for measuring rotating objects are discussed where a derotator needs to be used.

  10. 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.

  11. 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.

  12. Validation and intercomparison of Persistent Scatterers Interferometry: PSIC4 project results

    NARCIS (Netherlands)

    Raucoules, D.; Bourgine, B.; Michele, M. de; Le Cozannet, G.; Closset, L.; Bremmer, C.; Veldkamp, H.; Tragheim, D.; Bateson, L.; Crosetto, M.; Agudo, M.; Engdahl, M.

    2009-01-01

    This article presents the main results of the Persistent Scatterer Interferometry Codes Cross Comparison and Certification for long term differential interferometry (PSIC4) project. The project was based on the validation of the PSI (Persistent Scatterer Interferometry) data with respect to

  13. Progress in electron- and ion-interferometry

    International Nuclear Information System (INIS)

    Hasselbach, Franz

    2010-01-01

    In the 1970s the prominent goal was to overcome the limitations of electron microscopy caused by aberrations of electron lenses by the development of electron holography. In the meantime this problem has been solved, not only in the roundabout way of holography, but directly by correcting the aberrations of the lenses. Nevertheless, many quantitative electron microscopical measurement methods-e.g. mapping and visualization of electric and magnetic fields-were developed within the context of holography and have become fields of their own. In this review we focus on less popular electron interferometric experiments which complement the field of electron holography. The paper is organized as follows. After a short sketch of the development of electron biprism interferometry after its invention in 1954, recent advances in technology are discussed that made electron biprism interferometry an indispensable tool for solving fundamental and applied questions in physics: the development and preparation of conventional and single-atom field electron and field ion sources with their extraordinary properties. Single- and few-atom sources exhibit spectacular features: their brightness at 100 keV exceeds that of conventional field emitters by two orders in magnitude. Due to the extremely small aberrations of diode field emitter extraction optics, the virtual source size of single-atom tips is on the order of 0.2 nm. As a consequence it illuminates an area 7 cm in diameter on a screen at a distance of 15 cm coherently. Projection electron micrographs taken with these sources reach spatial resolutions of atomic dimensions and in-line holograms are-due to the absence of lenses with their aberrations-not blurred. Their reconstruction is straightforward. By addition of a carbon nanotube biprism into the beam path of a projection microscope a lensless electron interferometer has been realized. In extremely ultrahigh vacuum systems flicker noise is practically absent in the new sources

  14. Absolute marine gravimetry with matter-wave interferometry.

    Science.gov (United States)

    Bidel, Y; Zahzam, N; Blanchard, C; Bonnin, A; Cadoret, M; Bresson, A; Rouxel, D; Lequentrec-Lalancette, M F

    2018-02-12

    Measuring gravity from an aircraft or a ship is essential in geodesy, geophysics, mineral and hydrocarbon exploration, and navigation. Today, only relative sensors are available for onboard gravimetry. This is a major drawback because of the calibration and drift estimation procedures which lead to important operational constraints. Atom interferometry is a promising technology to obtain onboard absolute gravimeter. But, despite high performances obtained in static condition, no precise measurements were reported in dynamic. Here, we present absolute gravity measurements from a ship with a sensor based on atom interferometry. Despite rough sea conditions, we obtained precision below 10 -5  m s -2 . The atom gravimeter was also compared with a commercial spring gravimeter and showed better performances. This demonstration opens the way to the next generation of inertial sensors (accelerometer, gyroscope) based on atom interferometry which should provide high-precision absolute measurements from a moving platform.

  15. Pipeline monitoring with interferometry in non-arid regions

    Energy Technology Data Exchange (ETDEWEB)

    McCardle, Adrian; Rabus, Bernhard; Ghuman, Parwant [MacDonald Dettwiler, Richmond, BC (Canada); Freymueller, Jeff T. [University of Alaska, Fairbanks (United States)

    2005-07-01

    Interferometry has become a proven technique for accurately measuring ground movements caused by subsidence, landslides, earthquakes and volcanoes. Using space borne sensors such as the ERS, ENVISAT and RADARSAT satellites, ground deformation can be monitored on a millimeter level. Traditionally interferometry has been limited to arid areas however new technology has allowed for successful monitoring in vegetated regions and areas of changing land-cover. Analysis of ground movement of the Trans-Alaskan pipeline demonstrates how these techniques can offer pipeline engineers a new tool for observing potential dangers to pipeline integrity. Results from Interferometric Point Target Analysis were compared with GPS measurements and speckle tracking interferometry was demonstrated to measure a major earthquake. (author)

  16. Practical optical interferometry imaging at visible and infrared wavelengths

    CERN Document Server

    Buscher, David F

    2015-01-01

    Optical interferometry is a powerful technique to make images on angular scales hundreds of times smaller than is possible with the largest telescopes. This concise guide provides an introduction to the technique for graduate students and researchers who want to make interferometric observations and acts as a reference for technologists building new instruments. Starting from the principles of interference, the author covers the core concepts of interferometry, showing how the effects of the Earth's atmosphere can be overcome using closure phase, and the complete process of making an observation, from planning to image reconstruction. This rigorous approach emphasizes the use of rules-of-thumb for important parameters such as the signal-to-noise ratios, requirements for sampling the Fourier plane and predicting image quality. The handbook is supported by web resources, including the Python source code used to make many of the graphs, as well as an interferometry simulation framework, available at www.cambridg...

  17. Integrated Optics Achromatic Nuller for Stellar Interferometry

    Science.gov (United States)

    Ksendzov, Alexander

    2012-01-01

    This innovation will replace a beam combiner, a phase shifter, and a mode conditioner, thus simplifying the system design and alignment, and saving weight and space in future missions. This nuller is a dielectric-waveguide-based, four-port asymmetric coupler. Its nulling performance is based on the mode-sorting property of adiabatic asymmetric couplers that are intrinsically achromatic. This nuller has been designed, and its performance modeled, in the 6.5-micrometer to 9.25-micrometer spectral interval (36% bandwidth). The calculated suppression of starlight for this 15-cm-long device is 10(exp -5) or better through the whole bandwidth. This is enough to satisfy requirements of a flagship exoplanet-characterization mission. Nulling interferometry is an approach to starlight suppression that will allow the detection and spectral characterization of Earth-like exoplanets. Nulling interferometers separate the light originating from a dim planet from the bright starlight by placing the star at the bottom of a deep, destructive interference fringe, where the starlight is effectively cancelled, or nulled, thus allowing the faint off-axis light to be much more easily seen. This process is referred to as nulling of the starlight. Achromatic nulling technology is a critical component that provides the starlight suppression in interferometer-based observatories. Previously considered space-based interferometers are aimed at approximately 6-to-20-micrometer spectral range. While containing the spectral features of many gases that are considered to be signatures of life, it also offers better planet-to-star brightness ratio than shorter wavelengths. In the Integrated Optics Achromatic Nuller (IOAN) device, the two beams from the interferometer's collecting telescopes pass through the same focusing optic and are incident on the input of the nuller.

  18. Intracavity interferometry using synchronously pumped OPO

    Science.gov (United States)

    Zavadilová, Alena; Vyhlídal, David; Kubeček, Václav; Šulc, Jan; Navrátil, Petr

    2016-12-01

    The concept of system for intracavity interferometry based on the beat note detection in subharmonic synchronously intracavity pumped optical parametrical oscillator (OPO) is presented. The system consisted of SESAM-modelocked, picosecond, diode pumped Nd:YVO4 laser, operating at wavelength 1.06 μm and tunable linear intracavity pumped OPO based on MgO:PPLN crystal, widely tunable in 1.5 μm able to deliver two independent trains of picosecond pulses. The optical length of the OPO cavity was set to be exactly twice the pumping cavity length. In this configuration the OPO produces signal pulses with the same repetition frequency as the pump laser but the signal consists of two completely independent pulse trains. For purpose of pump probe measurements the setup signal with half repetition rate and scalable amplitude was derived from the OPO signal using RF signal divider, electropotical modulator and fiber amplifier. The impact of one pump beam on the sample is detected by one probing OPO train, the other OPO train is used as a reference. The beat note measured using the intracavity interferometer is proportional to phase modulation caused by the pump beam. The bandwidth of observed beat-note was less than 1 Hz (FWHM), it corresponds to a phase shift measurement error of less than 1.5 × 10-7 rad without any active stabilization. Such compact low-cost system could be used for ultra-sensitive phase-difference measurements (e.g. nonlinear refractive index measurement) for wide range of material especially in spectral range important for telecom applications.

  19. Photon exchange and decoherence in neutron interferometry

    International Nuclear Information System (INIS)

    Sulyok, G.

    2011-01-01

    The general subject of the present work concerns the action of time-dependent, spatially restricted magnetic fields on the wave function of a neutron. Special focus lies on their application in neutron interferometry. For arbitrary time-periodic fields, the corresponding Schroedinger equation is solved analytically. It is then shown, how the occurring exchange of energy quanta between the neutron and the modes of the magnetic field appears in the temporal modulation of the interference pattern between the original wavefunction and the wavefunction altered by the magnetic field. By Fourier analysis of the time-resolved interference pattern, the transition probabilities for all possible energy transfers are deducible. Experimental results for fields consisting of up to five modes are presented. Extending the theoretical approach by quantizing the magnetic field allows deeper insights on the underlying physical processes. For a coherent field state with a high mean photon number, the results of the calculation with classical fields is reproduced. By increasing the number of field modes whose relative phases are randomly distributed, one approaches the noise regime which offers the possibility of modelling decoherence in the neutron interferometer. Options and limitations of this modelling procedure are investigated in detail both theoretically and experimentally. Noise sources are applied in one or both interferometer path, and their strength, frequency bandwidth and position to each other is varied. In addition, the influence of increasing spatial separation of the neutron wave packet is examined, since the resulting Schroedinger cat-like states play an important role in decoherence theory. (author) [de

  20. Super-virtual refraction interferometry: Theory

    KAUST Repository

    Bharadwaj, Pawan

    2011-01-01

    Inverting for the subsurface velocity distribution by refraction traveltime tomography is a well-accepted imaging method by both the exploration and earthquake seismology communities. A significant drawback, however, is that the recorded traces become noisier with increasing offset from the source position, and so prevents accurate picking of traveltimes in far-offset traces. To enhance the signal-to-noise ratio of the far-offset traces, we present the theory of super-virtual refraction interferometry where the signal-to-noise ratio (SNR) of far-offset head-wave arrivals can be theoretically increased by a factor proportional to N; here, N is the number of receiver and source positions associated with the recording and generation of the head-wave arrival. There are two steps to this methodology: correlation and summation of the data to generate traces with virtual head-wave arrivals, followed by the convolution of the data with the virtual traces to create traces with super-virtual head-wave arrivals. This method is valid for any medium that generates head-wave arrivals. There are at least three significant benefits to this methodology: 1). enhanced SNR of far-offset traces so the first-arrival traveltimes of the noisy far-offset traces can be more reliably picked to extend the useful aperture of data, 2). the SNR of head waves in a trace that arrive after the first arrival can be enhanced for accurate traveltime picking and subsequent inversion by traveltime tomography, and 3). common receiver-pair gathers can be analyzed to detect the presence of diving waves in the first arrivals, which can be used to assess the nature of the refracting boundary. © 2011 Society of Exploration Geophysicists.

  1. Interferometry correlations in central p+Pb collisions

    Science.gov (United States)

    Bożek, Piotr; Bysiak, Sebastian

    2018-01-01

    We present results on interferometry correlations for pions emitted in central p+Pb collisions at √{s_{NN}}=5.02 TeV in a 3+1-dimensional viscous hydrodynamic model with initial conditions from the Glauber Monte Carlo model. The correlation function is calculated as a function of the pion pair rapidity. The extracted interferometry radii show a weak rapidity dependence, reflecting the lack of boost invariance of the pion distribution. A cross term between the out and long directions is found to be nonzero. The results obtained in the hydrodynamic model are in fair agreement with recent data of the ATLAS Collaboration.

  2. Mechanical Strain Measurement from Coda Wave Interferometry

    Science.gov (United States)

    Azzola, J.; Schmittbuhl, J.; Zigone, D.; Masson, F.; Magnenet, V.

    2017-12-01

    Coda Wave Interferometry (CWI) aims at tracking small changes in solid materials like rocks where elastic waves are diffusing. They are intensively sampling the medium, making the technique much more sensitive than those relying on direct wave arrivals. Application of CWI to ambient seismic noise has found a large range of applications over the past years like for multiscale imaging but also for monitoring complex structures such as regional faults or reservoirs (Lehujeur et al., 2015). Physically, observed changes are typically interpreted as small variations of seismic velocities. However, this interpretation remains questionable. Here, a specific focus is put on the influence of the elastic deformation of the medium on CWI measurements. The goal of the present work is to show from a direct numerical and experimental modeling that deformation signal also exists in CWI measurements which might provide new outcomes for the technique.For this purpose, we model seismic wave propagation within a diffusive medium using a spectral element approach (SPECFEM2D) during an elastic deformation of the medium. The mechanical behavior is obtained from a finite element approach (Code ASTER) keeping the mesh grid of the sample constant during the whole procedure to limit numerical artifacts. The CWI of the late wave arrivals in the synthetic seismograms is performed using both a stretching technique in the time domain and a frequency cross-correlation method. Both show that the elastic deformation of the scatters is fully correlated with time shifts of the CWI differently from an acoustoelastic effect. As an illustration, the modeled sample is chosen as an effective medium aiming to mechanically and acoustically reproduce a typical granitic reservoir rock.Our numerical approach is compared to experimental results where multi-scattering of an acoustic wave through a perforated loaded Au4G (Dural) plate is performed at laboratory scale. Experimental and numerical results of the

  3. Laser interferometry of radiation driven gas jets

    Science.gov (United States)

    Swanson, Kyle James; Ivanov, Vladimir; Mancini, Roberto; Mayes, Daniel C.

    2017-06-01

    In a series of experiments performed at the 1MA Zebra pulsed power accelerator of the Nevada Terawatt Facility nitrogen gas jets were driven with the broadband x-ray flux produced during the collapse of a wire-array z-pinch implosion. The wire arrays were comprised of 4 and 8, 10μm-thick gold wires and 17μm-thick nickel wires, 2cm and 3cm tall, and 0.3cm in diameter. They radiated 12kJ to 16kJ of x-ray energy, most of it in soft x-ray photons of less than 1keV of energy, in a time interval of 30ns. This x-ray flux was used to drive a nitrogen gas jet located at 0.8cm from the axis of the z-pinch radiation source and produced with a supersonic nozzle. The x-ray flux ionizes the nitrogen gas thus turning it into a photoionized plasma. We used laser interferometry to probe the ionization of the plasma. To this end, a Mach-Zehnder interferometer at the wavelength of 266 nm was set up to extract the atom number density profile of the gas jet just before the Zebra shot, and air-wedge interferometers at 266 and 532 nm were used to determine the electron number density of the plasma right during the Zebra shot. The ratio of electron to atom number densities gives the distribution of average ionization state of the plasma. A python code was developed to perform the image data processing, extract phase shift spatial maps, and obtain the atom and electron number densities via Abel inversion. Preliminary results from the experiment are promising and do show that a plasma has been created in the gas jet driven by the x-ray flux, thus demonstrating the feasibility of a new experimental platform to study photoionized plasmas in the laboratory. These plasmas are found in astrophysical scenarios including x-ray binaries, active galactic nuclei, and the accretion disks surrounding black holes1. This work was sponsored in part by DOE Office of Science Grant DE-SC0014451.1R. C. Mancini et al, Phys. Plasmas 16, 041001 (2009)

  4. Broadband RF Interferometric and Polarization Observations of Lightning Discharge Processes

    Science.gov (United States)

    Shao, X. M.; Ho, C.; Caffrey, M.; Graham, P.; Haynes, H.; Dingus, B.

    2017-12-01

    Broadband radio frequency interferometry was first introduced in 1996 for detailed lightning mapping studies [Shao et al., 1996], and the technique has since been improved significantly and has been increasingly widely used in the lightning research community. Due to continuously advancing data acquisition and computer capabilities, it is now possible to capture and process continuous broadband interferometer data for individual lightning flashes. In addition to the interferometric mapping of the lightning sources, we now introduce a broadband polarization capability that measures simultaneously the full polarization state of the corresponding broadband RF sources. Polarization observation provides another level of understanding of the discharge processes. For instance, a coherent breakdown process (e.g., relativistic runaway electron avalanches) is expected to produce highly polarized RF emissions, while an incoherent process related to thermal electrons is expected to produce randomly polarized RF emissions. For polarized emissions, the direction of the polarization is expected to aligned with the direction of the local electric field, and therefore can be used to understand the electric field structure at the breakdown locations. In the early summer of 2017, this new lightning system was tested in Los Alamos with a number of nearby lightning storms, and the system will be deployed in the late summer to the High Altitude Water Cherenkov Gamma-Ray Observatory (HAWC) on the flanks of the Sierra Negra volcano in Mexico at an altitude of 4.1km. HAWC is designed to observe high energy celestial gamma rays and cosmic rays with hundreds of water tanks. The goal of the collaborative lightning and HAWC observations is to understand the physics behind the lightning-related gamma-ray flashes (TGFs) and the initiation of the lightning discharges. We will report the new results from both the test observations and the HAWC observations. *Shao, X., D. Holden, and C. Rhodes

  5. P and S Velocity Structure in the Groningen Gas Reservoir From Noise Interferometry

    Science.gov (United States)

    Zhou, Wen; Paulssen, Hanneke

    2017-12-01

    Noise interferometry has proven to be a powerful tool to image seismic structure. In this study we used data from 10 geophones located in a borehole at ˜3 km depth within the Groningen gas reservoir in the Netherlands. The continuous data cross correlations show that noise predominantly comes in from above. The observed daily and weekly variations further indicate that the noise has an anthropogenic origin. The direct P wave emerges from the stacked vertical component cross correlations with frequencies up to 80 Hz and the direct S wave is retrieved from the horizontal components with frequencies up to 50 Hz. The measured intergeophone travel times were used to retrieve the P and S velocity structure along the borehole, and a good agreement was found with well log data. In addition, from the S wave polarizations, we determined azimuthal anisotropy with a fast direction of N65°W±18° and an estimated magnitude of (4±2)%. The fast polarization direction corresponds to the present direction of maximum horizontal stress measured at nearby boreholes but is also similar to the estimated paleostress direction.

  6. Matter wave interferometry in the light of Schroedinger's wave mechanics

    International Nuclear Information System (INIS)

    1987-01-01

    This is a pre-conference abstracts collection for 67 oral presentations and posters, 62 of them are in INIS scope and are treated individually. The subject matters are interferometers (mainly neutron), interferometry experiments and the related interpretation - and epistemological problems of quantum theory. (qui)

  7. Phase knife-edge laser Schlieren diffraction interferometry with ...

    Indian Academy of Sciences (India)

    The use of phase knife-edge as viewing diaphragm in Schlieren diffraction interferometry not only enhances the fringe contrast but also avoids the loss in phase information as it lets through light from all parts of the test object and its thin interfacing makes the method suitable even for studying weak disturbances. Keywords.

  8. Distinguishing between Dirac and Majorana neutrinos withtwo-particle interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, Thomas D.

    2006-03-02

    Two-particle interferometry, a second-order interferenceeffect, is explored as another possible tool to distinguish betweenmassive Dirac and Majorana neutrinos. A simple theoretical framework isdiscussed in the context of several gedanken experiments. The method canin principle provide both the mass scale and the quantum nature of theneutrino for a certain class of incoherent left-handed sourcecurrents.

  9. North and northeast Greenland ice discharge from satellite radar interferometry

    DEFF Research Database (Denmark)

    Rignot, E.J.; Gogineni, S.P.; Krabill, W.B.

    1997-01-01

    Ice discharge from north and northeast Greenland calculated from satellite radar interferometry data of 14 outlet glaciers is 3.5 times that estimated from iceberg production. The satellite estimates, obtained at the grounding line of the outlet glaciers, differ from those obtained at the glacier...

  10. Time-lapse controlled-source electromagnetics using interferometry

    NARCIS (Netherlands)

    Hunziker, J.W.; Slob, E.C.; Wapenaar, C.P.A.

    In time-lapse controlled-source electromagnetics, it is crucial that the source and the receivers are positioned at exactly the same location at all times of measurement. We use interferometry by multidimensional deconvolution (MDD) to overcome problems in repeatability of the source location.

  11. Microquake seismic interferometry with SVD-enhanced Green's function recovery

    OpenAIRE

    Melo, Gabriela; Malcolm, Alison E.

    2011-01-01

    The conditions under which seismic interferometry (SI) leads to the exact Green's function (GF) are rarely met in practice. As a result, we generally recover only estimates of the true GF. This raises the questions: How good an approximation to the GF can SI give? Can we improve this estimated GF?

  12. Application of Persistent Scatterer Interferometry (PSI) in monitoring ...

    Indian Academy of Sciences (India)

    Keywords. Slope instability; landslide; Lesser Himalaya; remote sensing; radar interferometry. Abstract. Orogenic movements and sub-tropical climate have rendered the slopes of the Himalayan region intensely deformed and weathered. As a result, the incidences of slope failure are quite common all along the Himalayan ...

  13. Radio astronomical interferometry and x-ray's computerized tomography

    International Nuclear Information System (INIS)

    Rodriguez, L.F.

    1982-01-01

    Radio astronomical interferometry and computerized tomography are techniques of great importance for astronomy and medicine, respectively. In this paper we emphasize that both techniques are based on the same mathematical principles, and present them as an example of interaction between basic and applied science. (author)

  14. Exploitation of distributed scatterers in synthetic aperture radar interferometry

    NARCIS (Netherlands)

    Samiei Esfahany, S.

    2017-01-01

    During the last decades, time-series interferometric synthetic aperture radar (InSAR) has emerged as a powerful technique to measure various surface deformation phenomena of the earth. Early generations of time-series InSAR methodologies, i.e. Persistent Scatterer Interferometry (PSI), focused on

  15. Pion interferometry theory for the hydrodynamic stage of multiple processes

    International Nuclear Information System (INIS)

    Makhlin, A.N.; Sinyukov, Yu.M.

    1986-01-01

    The double pion inclusive cross section for identical particles is described in hydrodynamical theory of multiparticle production. The pion interferometry theory is developed for the case when secondary particles are generated against the background of internal relativistic motion of radiative hadron matter. The connection between correlation functions in various schemes of experiment is found within the framework of relativistic Wigner functions formalism

  16. Micro-Gal level gravity measurements with cold atom interferometry

    International Nuclear Information System (INIS)

    Zhou Min-Kang; Duan Xiao-Chun; Chen Le-Le; Luo Qin; Xu Yao-Yao; Hu Zhong-Kun

    2015-01-01

    Developments of the micro-Gal level gravimeter based on atom interferometry are reviewed, and the recent progress and results of our group are also presented. Atom interferometric gravimeters have shown high resolution and accuracy for gravity measurements. This kind of quantum sensor has excited world-wide interest for both practical applications and fundamental research. (topical review)

  17. Global-scale seismic interferometry : Theory and numerical examples

    NARCIS (Netherlands)

    Ruigrok, E.N.; Draganov, D.S.; Wapenaar, K.

    2008-01-01

    Progress in the imaging of the mantle and core is partially limited by the sparse distribution of natural sources; the earthquake hypocenters are mainly along the active lithospheric plate boundaries. This problem can be approached with seismic interferometry. In recent years, there has been

  18. Michelson wide-field stellar interferometry : Principles and experimental verification

    NARCIS (Netherlands)

    Montilla, I.; Pereira, S.F.; Braat, J.J.M.

    2005-01-01

    A new interferometric technique for Michelson wide-field interferometry is presented that consists of a Michelson pupil-plane combination scheme in which a wide field of view can be achieved in one shot. This technique uses a stair-shaped mirror in the intermediate image plane of each telescope in

  19. 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.

  20. 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

  1. X-ray Talbot interferometry with capillary plates

    International Nuclear Information System (INIS)

    Momose, Atsushi; Kawamoto, Shinya

    2006-01-01

    An X-ray Talbot interferometer consisting of two capillary plates, which were used as X-ray amplitude gratings, was evaluated for X-ray phase imaging. A theoretical aspect of capillary X-ray Talbot interferometry is presented with a preliminary operation result using synchrotron radiation. A two-dimensional X-ray Talbot effect, or self-imaging effect, which was the basis of Talbot interferometry, was observed with the capillary plate, and moire images formed by the X-ray Talbot interferometer exhibited contrasts corresponding to the differential phase shift caused by phase objects placed in front of the interferometer. Finally, the possibility of quantitative phase measurement with a fringe scanning technique is discussed. (author)

  2. A recent history of science cases for optical interferometry

    Science.gov (United States)

    Defrère, Denis; Aerts, Conny; Kishimoto, Makoto; Léna, Pierre

    2018-04-01

    Optical long-baseline interferometry is a unique and powerful technique for astronomical research. Since the 1980's (with I2T, GI2T, Mark I to III, SUSI, ...), optical interferometers have produced an increasing number of scientific papers covering various fields of astrophysics. As current interferometric facilities are reaching their maturity, we take the opportunity in this paper to summarize the conclusions of a few key meetings, workshops, and conferences dedicated to interferometry. We present the most persistent recommendations related to science cases and discuss some key technological developments required to address them. In the era of extremely large telescopes, optical long-baseline interferometers will remain crucial to probe the smallest spatial scales and make breakthrough discoveries.

  3. High-speed real-time holographic interferometry

    Science.gov (United States)

    Yamamoto, Yoshitaka

    1999-06-01

    The principle of holography was invented by Dr. Gabor in 1948 before the invention of the laser. In 1962, after the invention of laser (in 1960: the first demonstration of laser oscillation by Maiman was achieved using a ruby cubic crystal), the off-axis reference beam holography was developed by Prof. Leith and Mr. Upatnieks. One of the most useful measuring techniques of the holography is a holographic interferometry. Holography enable to storage signal wave fronts and reconstruct it at later time, then the interference between the reconstructed signal wave fronts and the wave fronts come from the object to be able to generate an interference fringes. Real-time holographic interferometry can measure real-time phase-change of phenomena. Therefore, this method has the performance of continuously measuring phase change by coupling with high-speed cameras.

  4. Phase and fringe order determination in wavelength scanning interferometry.

    Science.gov (United States)

    Moschetti, Giuseppe; Forbes, Alistair; Leach, Richard K; Jiang, Xiang; O'Connor, Daniel

    2016-04-18

    A method to obtain unambiguous surface height measurements using wavelength scanning interferometry with an improved repeatability, comparable to that obtainable using phase shifting interferometry, is reported. Rather than determining the conventional fringe frequency-derived z height directly, the method uses the frequency to resolve the fringe order ambiguity, and combine this information with the more accurate and repeatable fringe phase derived z height. A theoretical model to evaluate the method's performance in the presence of additive noise is derived and shown to be in good agreement with experiments. The measurement repeatability is improved by a factor of ten over that achieved when using frequency information alone, reaching the sub-nanometre range. Moreover, the z-axis non-linearity (bleed-through or ripple error) is reduced by a factor of ten. These order of magnitude improvements in measurement performance are demonstrated through a number of practical measurement examples.

  5. Optical Distortion Evaluation in Large Area Windows using Interferometry

    Science.gov (United States)

    Youngquist, Robert C.; Skow, Miles; Nurge, Mark A.

    2015-01-01

    It is important that imagery seen through large area windows, such as those used on space vehicles, not be substantially distorted. Many approaches are described in the literature for measuring the distortion of an optical window, but most suffer from either poor resolution or processing difficulties. In this paper a new definition of distortion is presented, allowing accurate measurement using an optical interferometer. This new definition is shown to be equivalent to the definitions provided by the military and the standards organizations. In order to determine the advantages and disadvantages of this new approach the distortion of an acrylic window is measured using three different methods; image comparison, Moiré interferometry, and phase-shifting interferometry.

  6. MAGIA - using atom interferometry to determine the Newtonian gravitational constant

    International Nuclear Information System (INIS)

    Stuhler, J; Fattori, M; Petelski, T; Tino, G M

    2003-01-01

    We describe our experiment MAGIA (misura accurata di G mediante interferometria atomica), in which we will use atom interferometry to perform a high precision measurement of the Newtonian gravitational constant G. Free-falling laser-cooled atoms in a vertical atomic fountain will be accelerated due to the gravitational potential of nearby source masses (SMs). Detecting this acceleration with techniques of Raman atom interferometry will enable us to assign a value to G. To suppress systematic effects we will implement a double-differential measurement. This includes launching two atom clouds in a gradiometer configuration and moving the SMs to different vertical positions. We briefly summarize the general idea of the MAGIA experiment and put it in the context of other high precision G-measurements. We present the current status of the experiment and report on analyses of the expected measurement accuracy

  7. VISUALISASI SIMPANGAN GETARAN DENGAN METODE INTERFEROMETRI POLA SPEKEL ELEKTRONIK

    Directory of Open Access Journals (Sweden)

    Muchiar Muchiar

    2015-08-01

    Full Text Available Simpangan getaran sebuah membran berupa membran bundar yang bergetar sinusoidal, telah dvisualisasikan dengan menggunakan Metode Interferometri Pola Spekel Elektronik. Pola spekel dari permukaan membran pada saat tidak bergetar dan pada saat sedang bergetar pada frekuensi dan amplitudo tertentu, masing-masing, direkam dengan kamera CCD dan datanya disimpan didalam komputer. Selanjutnya, masing-masing data pola spekel membran yang sedang bergetar tersebut di substraksi dengan data pola spekel membran dalam keadaan diam. Hasil yang diperoleh berupa visualisasi citra spekel simpangan rata-rata permukaan membran yang disertai dengan pola frinji tertentu. Bentuk dari pola frinji yang terjadi bersesuaian dengan pola simpangan getaran yang dialami oleh bagian permukaan membran. Sedangkan jumlah pola frinji yang terjadi bersesuain dengan besarnya simpangan rata-rata yang terjadi. Metode ini mensyaratkan perioda getaran membran jauh lebih pendek dibandingkan waktu perekaman kamera CCD. Dari segi kualitas, metode ini menghasilkan citra tidaklah sebaik atau setajam yang diperoleh dengan Metode Interferometri Holografi.

  8. Spectrally controlled interferometry for measurements of flat and spherical optics

    Science.gov (United States)

    Salsbury, Chase; Olszak, Artur G.

    2017-10-01

    Conventional interferometry is widely used to measure spherical and at surfaces with nanometer level precision but is plagued by back reflections. We describe a new method of isolating the measurement surface by controlling spectral properties of the source (Spectrally Controlled Interferometry - SCI). Using spectral modulation of the interferometer's source enables formation of localized fringes where the optical path difference is non-zero. As a consequence it becomes possible to form white-light like fringes in common path interferometers, such as the Fizeau. The proposed setup does not require mechanical phase shifting, resulting in simpler instruments and the ability to upgrade existing interferometers. Furthermore, it allows absolute measurement of distance, including radius of curvature of lenses in a single setup with possibility of improving the throughput and removing some modes of failure.

  9. Holodiagram: elliptic visualizing interferometry, relativity, and light-in-flight.

    Science.gov (United States)

    Abramson, Nils H

    2014-04-10

    In holographic interferometry, there is usually a static distance separating the point of illumination and the point of observation. In Special Relativity, this separation is dynamic and is caused by the velocity of the observer. The corrections needed to compensate for these separations are similar in the two fields. We use the ellipsoids of the holodiagram for measurement and in a graphic way to explain and evaluate optical resolution, gated viewing, radar, holography, three-dimensional interferometry, Special Relativity, and light-in-flight recordings. Lorentz contraction together with time dilation is explained as the result of the eccentricity of the measuring ellipsoid, caused by its velocity. The extremely thin ellipsoid of the very first light appears as a beam aimed directly at the observer, which might explain the wave or ray duality of light and entanglement. Finally, we introduce the concept of ellipsoids of observation.

  10. North and northeast Greenland ice discharge from satellite radar interferometry

    DEFF Research Database (Denmark)

    Rignot, E.J.; Gogineni, S.P.; Krabill, W.B.

    1997-01-01

    Ice discharge from north and northeast Greenland calculated from satellite radar interferometry data of 14 outlet glaciers is 3.5 times that estimated from iceberg production. The satellite estimates, obtained at the grounding line of the outlet glaciers, differ from those obtained at the glacier...... front, because basal melting is extensive at the underside of the floating glacier sections. The results suggest that the north and northeast parts of the Greenland ice sheet may be thinning and contributing positively to sea-level rise.......Ice discharge from north and northeast Greenland calculated from satellite radar interferometry data of 14 outlet glaciers is 3.5 times that estimated from iceberg production. The satellite estimates, obtained at the grounding line of the outlet glaciers, differ from those obtained at the glacier...

  11. Polarimetric SAR interferometry applied to land ice: modeling

    DEFF Research Database (Denmark)

    Dall, Jørgen; Papathanassiou, Konstantinos; Skriver, Henning

    2004-01-01

    depths. The validity of the scattering models is examined using L-band polarimetric interferometric SAR data acquired with the EMISAR system over an ice cap located in the percolation zone of the Greenland ice sheet. Radar reflectors were deployed on the ice surface prior to the data acquisition in order......This paper introduces a few simple scattering models intended for the application of polarimetric SAR interfer-ometry to land ice. The principal aim is to eliminate the penetration bias hampering ice sheet elevation maps generated with single-channel SAR interferometry. The polarimetric coherent...... scattering models are similar to the oriented-volume model and the random-volume-over-ground model used in vegetation studies, but the ice models are adapted to the different geometry of land ice. Also, due to compaction, land ice is not uniform; a fact that must be taken into account for large penetration...

  12. A novel plasmonic interferometry and the potential applications

    Science.gov (United States)

    Ali, J.; Pornsuwancharoen, N.; Youplao, P.; Aziz, M. S.; Chiangga, S.; Jaglan, J.; Amiri, I. S.; Yupapin, P.

    2018-03-01

    In this article, we have proposed the plasmonic interferometry concept and analytical details given. By using the conventional optical interferometry, which can be simply calculated by using the relationship between the electric field and electron mobility, the interference mobility visibility (fringe visibility) can be observed. The surface plasmons in the sensing arm of the Michelson interferometer is constructed by the stacked layers of the silicon-graphene-gold, allows to characterize the spatial resolution of light beams in terms of the electron mobility down to 100-nm scales, with measured coherence lengths as low as ∼100 nm for an incident wavelength of 1550 nm. We have demonstrated a compact plasmonic interferometer that can apply to the electron mean free paths measurement, from which the precise determination can be used for the high-resolution mean free path measurement and sensing applications. This system provides the practical simulation device parameters that can be fabricated and tested by the experimental platform.

  13. Atomic Interferometry with Detuned Counter-Propagating Electromagnetic Pulses

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, Ming -Yee [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-09-05

    Atomic fountain interferometry uses atoms cooled with optical molasses to 1 μK, which are then launched in a fountain mode. The interferometer relies on the nonlinear Raman interaction of counter-propagating visible light pulses. We present models of these key transitions through a series of Hamiltonians. Our models, which have been verified against special cases with known solutions, allow us to incorporate the effects of non-ideal pulse shapes and realistic laser frequency or wavevector jitter.

  14. Pion interferometry of ultra-relativistic hadronic collisions

    International Nuclear Information System (INIS)

    Kolehmainen, K.

    1986-05-01

    Pion interferometry of ultra-relativistic hadronic collisions is described in the context of the inside-outside cascade model using a current ensemble method capable of describing an arbitrary distribution of pion sources with an arbitrary velocity distribution. The results are quite distinct from the usual Gaussian and Kopylov parameterizations. Extraction of the temperature parameter, effective source lifetime, and transverse size requires a full three-dimensional analysis of the correlation function in terms of the momentum difference. 7 refs., 4 figs

  15. Real-time laser holographic interferometry for aerodynamics

    International Nuclear Information System (INIS)

    Lee, G.

    1987-01-01

    Recent developments in thermoplastic recording holograms and advancements in automated image digitalization and analysis make real-time laser holographic interferometry feasible for two-dimensional flows such as airfoil flows. Typical airfoil measurements would include airfoil pressure distributions, wake and boundary layer profiles, and flow field density contours. This paper addresses some of the problems and requirements of a real-time laser holographic interferometer. 13 references

  16. Using Atom Interferometry to Search for New Forces

    International Nuclear Information System (INIS)

    Wacker, Jay G.

    2009-01-01

    Atom interferometry is a rapidly advancing field and this Letter proposes an experiment based on existing technology that can search for new short distance forces. With current technology it is possible to improve the sensitivity by up to a factor of 10 2 and near-future advances will be able to rewrite the limits for forces with ranges from 100 (micro)m to 1km.

  17. Laser Development for Gravitational-Wave Interferometry in Space

    Science.gov (United States)

    Numata, Kenji; Camp, Jordan

    2012-01-01

    We are reporting on our development work on laser (master oscillator) and optical amplifier systems for gravitational-wave interferometry in space. Our system is based on the mature, wave-guided optics technologies, which have advantages over bulk, crystal-based, free-space optics. We are investing in a new type of compact, low-noise master oscillator, called the planar-waveguide external cavity diode laser. We made measurements, including those of noise, and performed space-qualification tests.

  18. Conoscopic interferometry of surface-acoustic-wave substrate crystals.

    Science.gov (United States)

    Ayräs, P H; Friberg, A T; Kaivola, M A; Salomaa, M M

    1999-09-01

    Conoscopic interferometry is applied for determining the crystal orientation of lithium niobate and other commonly employed substrate wafers for integrated-optic and surface-acoustic-wave devices. The method is particularly applicable for detecting the orientation of the optic axes of the strongly birefringent niobate but is less sensitive for lithium tantalate or quartz. Conoscopic interference is a low-cost and easy-to-use method that is especially suitable for laboratory usage.

  19. Using atom interferometry to search for new forces

    International Nuclear Information System (INIS)

    Wacker, Jay G.

    2010-01-01

    Atom interferometry is a rapidly advancing field and this Letter proposes an experiment based on existing technology that can search for new short distance forces. With current technology it is possible to improve the sensitivity by up to a factor of 10 2 and near-future advances may be able to rewrite the limits for forces with ranges from 1 mm to 100 m.

  20. Planet finding prospects for the Space Interferometry Mission

    OpenAIRE

    Ford, Eric B.; Tremaine, Scott

    2003-01-01

    The Space Interferometry Mission (SIM) will make precise astrometric measurements that can be used to detect planets around nearby stars. We have simulated SIM observations and estimated the ability of SIM to detect planets with given masses and orbital periods and measure their orbital elements. We combine these findings with an estimate of the mass and period distribution of planets determined from radial velocity surveys to predict the number and characteristics of planets SIM would likely...

  1. Neutron Interferometry in NPI Řež

    Czech Academy of Sciences Publication Activity Database

    Vrána, Miroslav; Mikula, Pavol; Lukáš, Petr; Ioffe, A.; Nistler, W.

    2001-01-01

    Roč. 70, - (2001), s. 465-467 ISSN 0031-9015. [Proceedings of the International Sympozium on Advanced Science Research /1./. Tokai, 31.10.2000-02.11.2000] R&D Projects: GA ČR GV202/97/K038; GA AV ČR IAA1048003 Institutional research plan: CEZ:AV0Z1048901 Keywords : neutron interferometry * scattering lenght Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.628, year: 2001

  2. Deformation Measurement Of Lumbar Vertebra By Holographic Interferometry

    Science.gov (United States)

    Matsumoto, Toshiro; Kojima, Arata; Ogawa, Ryoukei; Iwata, Koichi; Nagata, Ryo

    1988-01-01

    The mechanical properties of normal lumbar vertebra and one with the interarticular part cut off to simulate hemi-spondylolysis were measured by the double exposure holographic interferometry. In the normal lumbar vertebra, displacement due to the load applied to the inferior articular process was greater than that of superior articular process under the same load. The interarticular part was subjected to the high stress. From these points, one of the valuable data to consider the cause of spondylolysis was obtained.

  3. Special topics in infrared interferometry. [Michelson interferometer development

    Science.gov (United States)

    Hanel, R. A.

    1985-01-01

    Topics in IR interferometry related to the development of a Michelson interferometer are treated. The selection and reading of the signal from the detector to the analog to digital converter is explained. The requirements for the Michelson interferometer advance speed are deduced. The effects of intensity modulation on the interferogram are discussed. Wavelength and intensity calibration of the interferometer are explained. Noise sources (Nyquist or Johnson noise, phonon noise), definitions of measuring methods of noise, and noise measurements are presented.

  4. 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.

  5. Neutron Interferometry at the National Institute of Standards and Technology

    International Nuclear Information System (INIS)

    Huber, M. G.; Sarenac, D.; Nsofini, J.; Pushin, D. A.; Arif, M.; Wood, C. J.; Cory, D. G.; Shahi, C. B.

    2015-01-01

    Neutron interferometry has proved to be a very precise technique for measuring the quantum mechanical phase of a neutron caused by a potential energy difference between two spatially separated neutron paths inside interferometer. The path length inside the interferometer can be many centimeters (and many centimeters apart) making it very practical to study a variety of samples, fields, potentials, and other macroscopic medium and quantum effects. The precision of neutron interferometry comes at a cost; neutron interferometers are very susceptible to environmental noise that is typically mitigated with large, active isolated enclosures. With recent advances in quantum information processing especially quantum error correction (QEC) codes we were able to demonstrate a neutron interferometer that is insensitive to vibrational noise. A facility at NIST’s Center for Neutron Research (NCNR) has just been commissioned with higher neutron flux than the NCNR’s older interferometer setup. This new facility is based on QEC neutron interferometer, thus improving the accessibility of neutron interferometry to the greater scientific community and expanding its applications to quantum computing, gravity, and material research

  6. Interferometry imaging technique for accurate deep-space probe positioning

    Science.gov (United States)

    Zheng, Weimin; Tong, Fengxian; Zhang, Juan; Liu, Lei; Shu, Fengchun

    2017-12-01

    Very long baseline interferometry (VLBI) is a radio astronomy tool with very high spatial resolution. It uses two or more radio telescopes to track the faraway object and gets its visibility. The intensity distribution image of radio source can be obtained by the inverse Fourier transformation of the visibilities sampled on UV plane perpendicular to the line of sight. Chinese VLBI Network (CVN) consists of 5 radio telescopes, and its highest spatial resolution is equivalent to that of a ∼3000 km diameters single dish antenna. This paper introduces the interferometry imaging principle, the imaging results of ChangE lunar and Mars Express probes. The measured ChangE-3 (CE-3) Rover relative position accuracy is about 1 m by this method. The 1 m accuracy is verified by comparisons with Rover null position and the onboard stereo vision measurement results. The successful imaging of spacecraft indicates that the interferometry imaging technology can be used for accurate spacecraft positioning in the future.

  7. Acoustic noise interferometry in a time-dependent coastal ocean.

    Science.gov (United States)

    Godin, Oleg A

    2018-02-01

    Interferometry of underwater noise provides a way to estimate physical parameters of the water column and the seafloor without employing any controlled sound sources. In applications of acoustic noise interferometry to coastal oceans, the propagation environment changes appreciably during the averaging times that are necessary for the Green's functions to emerge from noise cross-correlations. Here, a theory is developed to quantify the effects of nonstationarity of the propagation environment on two-point correlation functions of diffuse noise. It is shown that temporal variability of the ocean limits from above the frequency range, where noise cross-correlations approximate the Green's functions. The theoretical predictions are in quantitative agreement with results of the 2012 noise interferometry experiment in the Florida Straits. The loss of coherence at high frequencies constrains the passive acoustic remote sensing to exploiting a low-frequency part of measured noise cross-correlations, thus limiting the resolution of deterministic inversions. On the other hand, the passively measured coherence loss contains information about statistical characteristics of the ocean dynamics at unresolved spatial and temporal scales.

  8. Analysis of surface absorbed dose in X-ray grating interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhili, E-mail: wangnsrl@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China); Wu, Zhao; Gao, Kun; Wang, Dajiang; Chen, Heng; Wang, Shenghao [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China); Wu, Ziyu, E-mail: wuzy@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2014-10-15

    Highlights: • Theoretical framework for dose estimation in X-ray grating interferometry. • Potential dose reduction of X-ray grating interferometry compared to conventional radiography. • Guidelines for optimization of X-ray grating interferometry for dose-sensitive applications. • Measure to compare various existing X-ray phase contrast imaging techniques. - Abstract: X-ray phase contrast imaging using grating interferometry has shown increased contrast over conventional absorption imaging, and therefore the great potential of dose reduction. The extent of the dose reduction depends on the geometry of grating interferometry, the photon energy, the properties of the sample under investigation and the utilized detector. These factors also determine the capability of grating interferometry to distinguish between different tissues with a specified statistical certainty in a single raw image. In this contribution, the required photon number for imaging and the resulting surface absorbed dose are determined in X-ray grating interferometry, using a two-component imaging object model. The presented results confirm that compared to conventional radiography, phase contrast imaging using grating interferometry indeed has the potential of dose reduction. And the extent of dose reduction is strongly dependent on the imaging conditions. Those results provide a theoretical framework for dose estimation under given imaging conditions before experimental trials, and general guidelines for optimization of grating interferometry for those dose-sensitive applications.

  9. Analysis of surface absorbed dose in X-ray grating interferometry

    International Nuclear Information System (INIS)

    Wang, Zhili; Wu, Zhao; Gao, Kun; Wang, Dajiang; Chen, Heng; Wang, Shenghao; Wu, Ziyu

    2014-01-01

    Highlights: • Theoretical framework for dose estimation in X-ray grating interferometry. • Potential dose reduction of X-ray grating interferometry compared to conventional radiography. • Guidelines for optimization of X-ray grating interferometry for dose-sensitive applications. • Measure to compare various existing X-ray phase contrast imaging techniques. - Abstract: X-ray phase contrast imaging using grating interferometry has shown increased contrast over conventional absorption imaging, and therefore the great potential of dose reduction. The extent of the dose reduction depends on the geometry of grating interferometry, the photon energy, the properties of the sample under investigation and the utilized detector. These factors also determine the capability of grating interferometry to distinguish between different tissues with a specified statistical certainty in a single raw image. In this contribution, the required photon number for imaging and the resulting surface absorbed dose are determined in X-ray grating interferometry, using a two-component imaging object model. The presented results confirm that compared to conventional radiography, phase contrast imaging using grating interferometry indeed has the potential of dose reduction. And the extent of dose reduction is strongly dependent on the imaging conditions. Those results provide a theoretical framework for dose estimation under given imaging conditions before experimental trials, and general guidelines for optimization of grating interferometry for those dose-sensitive applications

  10. LCD panel characterization by measuring full Jones matrix of individual pixels using polarization-sensitive digital holographic microscopy.

    Science.gov (United States)

    Park, Jongchan; Yu, Hyeonseung; Park, Jung-Hoon; Park, YongKeun

    2014-10-06

    We present measurements of the full Jones matrix of individual pixels in a liquid-crystal display (LCD) panel. Employing a polarization-sensitive digital holographic microscopy based on Mach-Zehnder interferometry, the complex amplitudes of the light passing through individual LCD pixels are precisely measured with respect to orthogonal bases of polarization states, from which the full Jones matrix components of individual pixels are obtained. We also measure the changes in the Jones matrix of individual LCD pixels with respect to an applied bias. In addition, the complex optical responses of a LCD panel with respect to arbitrary polarization states of incident light were characterized from the measured Jones matrix.

  11. Space-bandwidth extension in parallel phase-shifting digital holography using a four-channel polarization-imaging camera.

    Science.gov (United States)

    Tahara, Tatsuki; Ito, Yasunori; Xia, Peng; Awatsuji, Yasuhiro; Nishio, Kenzo; Ura, Shogo; Kubota, Toshihiro; Matoba, Osamu

    2013-07-15

    We propose a method for extending the space bandwidth (SBW) available for recording an object wave in parallel phase-shifting digital holography using a four-channel polarization-imaging camera. A linear spatial carrier of the reference wave is introduced to an optical setup of parallel four-step phase-shifting interferometry using a commercially available polarization-imaging camera that has four polarization-detection channels. Then a hologram required for parallel two-step phase shifting, which is a technique capable of recording the widest SBW in parallel phase shifting, can be obtained. The effectiveness of the proposed method was numerically and experimentally verified.

  12. Very-Long-Baseline Radio Interferometry: The Mark III System for Geodesy, Astrometry, and Aperture Synthesis.

    Science.gov (United States)

    Rogers, A E; Cappallo, R J; Hinteregger, H F; Levine, J I; Nesman, E F; Webber, J C; Whitney, A R; Clark, T A; Ma, C; Ryan, J; Corey, B E; Counselman, C C; Herring, T A; Shapiro, I I; Knight, C A; Shaffer, D B; Vandenberg, N R; Lacasse, R; Mauzy, R; Rayhrer, B; Schupler, B R; Pigg, J C

    1983-01-07

    The Mark III very-long-baseline interferometry (VLBI) system allows recording and later processing of up to 112 megabits per second from each radio telescope of an interferometer array. For astrometric and geodetic measurements, signals from two radio-frequency bands (2.2 to 2.3 and 8.2 to 8.6 gigahertz) are sampled and recorded simultaneously at all antenna sites. From these dual-band recordings the relative group delays of signals arriving at each pair of sites can be corrected for the contributions due to the ionosphere. For many radio sources for which the signals are sufficiently intense, these group delays can be determined with uncertainties under 50 picoseconds. Relative positions of widely separated antennas and celestial coordinates of radio sources have been determined from such measurements with 1 standard deviation uncertainties of about 5 centimeters and 3 milliseconds of arc, respectively. Sample results are given for the lengths of baselines between three antennas in the United States and three in Europe as well as for the arc lengths between the positions of six extragalactic radio sources. There is no significant evidence of change in any of these quantities. For mapping the brightness distribution of such compact radio sources, signals of a given polarization, or of pairs of orthogonal polarizations, can be recorded in up to 28 contiguous bands each nearly 2 megahertz wide. The ability to record large bandwidths and to link together many large radio telescopes allows detection and study of compact sources with flux densities under 1 millijansky.

  13. Polarity influence on the indentation punching of thin {111} GaAs foils at elevated temperatures

    International Nuclear Information System (INIS)

    Patriarche, G; Largeau, L; Riviere, J P; Bourhis, E Le

    2005-01-01

    Thin {111} GaAs substrates were deformed by a Vickers indenter at 350 deg. C-370 deg. C under loads ranging between 0.4 and 1.9 N. Optical microscopy and interferometry were used to observe the indented and opposite faces of the thin foils and hence to investigate the plastic flow through the samples. Attention was paid to the polarity (A or B) of the specimen surface, as GaAs is known to show a large difference between α and β dislocations mobilities. A model considering the influence of polarity is proposed to describe the material flow throughout thin samples

  14. 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.

  15. Electromagnetic interferometry in wavenumber and space domains in a layered earth

    NARCIS (Netherlands)

    Hunziker, J.W.; Slob, E.C.; Fan, Y.; Snieder, R.; Wapenaar, C.P.A.

    2013-01-01

    With interferometry applied to controlled-source electromagnetic data, the direct field and the airwave and all other effects related to the air-water interface can be suppressed in a data-driven way. Interferometry allows for retreival of the scattered field Green’s function of the subsurface or,

  16. Visualization and direct comparison of large displacements using difference holographic interferometry

    International Nuclear Information System (INIS)

    Necati Ecevit, F.; Aydin, R.

    1994-01-01

    The difference holographic interferometry provides the possibility of direct comparison of large displacements and deformations of two similar but different objects by application of a special kind of illumination. In this work, the principles of the difference holographic interferometry and the experimental results obtained by applying the single beam technique to large displacements is presented. (author). 10 refs, 4 figs

  17. Measurement of Microscopic Deformations Using Double-Exposure Holographic Interferometry and the Fourier Transform Method

    Directory of Open Access Journals (Sweden)

    Percival Almoro

    1998-12-01

    Full Text Available Microscopic deformations on the surface of a circular diaphragm were measured using double exposure holographic interferometry and Fourier transform method (FTM. The three-dimensional surface deformations were successfully visualized by applying FTM to holographic interferogram analysis. The minimum surface displacement measured was 0.317 µm. This was calibrated via the Michelson interferometry technique.

  18. New developments in NDT through electronic speckle pattern interferometry

    International Nuclear Information System (INIS)

    Mohan, S.; Murugesan, P; Mas, R.H.

    2007-01-01

    Full text: Optical holography and speckle interferometry are the emerging optical techniques that can be used for the measurements of microscopic parameters such as displacement, strain, stress and slope. These techniques are applied in various fields such as surface studies, non destructive testing, speckle metrology and steller interferometry. Even though many new NDT methods are available, the suitability for a specific application is based on the material property, nature of defects and sensitivity of detection. Difficulty in radiographic technique is that it fails in detecting tight cracks, planar defects and debonds. Microwave techniques has limited sensitivity for the defect detection and it is not suitable for the objects with metallic cases since the metals are perfect reflectors for the microwaves. Low modulus material attenuates the acoustic energy completely, making ultrasonic testing techniques not feasible. The recently evolved optoelectronic technique namely Electronic Speckle Pattern interferometry (ESPI) is a fast developing optical technique widely used for measuring displacement components, their derivatives, surface roughness, surface contours, shape and others. Due to non contact nature and high sensitivity, this technique has been used as a powerful on line inspection tool for non destructive pattern of materials in industrial environment. The salient feature of ESPI is its capability to display the correlation fringes in a real time on a monitor without the need of photographic processing or optical filtering. ESPI is an alternate non destructive technique suitable for propellant grains and other low modulus materials used in space vehicle systems. The optoelectronic technique can be used to detect cracks, voids and residual stresses etc.., in the components in the industrial environment. In the present investigation, speckle non destructive testing has been carried out on some selected low modulus materials used in space vehicles. The

  19. Self-calibration in optical/infrared interferometry

    Science.gov (United States)

    Millour, Florentin; Dalla Vedova, Gaetan

    2015-08-01

    Optical interferometry produces nowadays images of the observed stars. However, the image quality of the current facilities (VLTI, CHARA) is impaired by the lack of phases measurements. We will describe here a method used to improve the image reconstruction that takes profit of a badly used observable: the wavelength differential phase. This phase shares some properties with the interferometric phase. That method is parent to the self-calibration which was developed in the 80's for radio astronomy to get rid of calibratioon artifacts, and produces a significant improvement on image quality over the current available methods.

  20. Precision Gravity Tests with Atom Interferometry in Space

    Energy Technology Data Exchange (ETDEWEB)

    Tino, G.M.; Sorrentino, F. [Dipartimento di Fisica e Astronomia and LENS, Università di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (Italy); Aguilera, D. [Institute of Space Systems, German Aerospace Center, Robert-Hooke-Strasse 7, 28359 Bremen (Germany); Battelier, B.; Bertoldi, A. [Laboratoire Photonique, Numérique et Nanosciences, LP2N - UMR5298 - IOGS - CNRS Université Bordeaux 1, Bâtiment A30 351 cours de la Libération F-33405 TALENCE Cedex France (France); Bodart, Q. [Dipartimento di Fisica e Astronomia and LENS, Università di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (Italy); Bongs, K. [Midlands Ultracold Atom Research Centre School of Physics and Astronomy University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Bouyer, P. [Laboratoire Photonique, Numérique et Nanosciences, LP2N - UMR5298 - IOGS - CNRS Université Bordeaux 1, Bâtiment A30 351 cours de la Libération F-33405 TALENCE Cedex France (France); Braxmaier, C. [Institute of Space Systems, German Aerospace Center, Robert-Hooke-Strasse 7, 28359 Bremen (Germany); Cacciapuoti, L. [European Space Agency, Research and Scientific Support Department, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Gaaloul, N. [Institute of Quantum Optics, Leibniz Universitaet Hannover, Welfengarten 1, D 30167 Hannover (Germany); Gürlebeck, N. [University of Bremen, Centre of Applied Space Technology and Microgravity (ZARM), Am Fallturm, D - 29359 Bremen (Germany); Hauth, M. [Humboldt-Universität zu Berlin, Newtonstr. 15, D-12489 Berlin (Germany); and others

    2013-10-15

    Atom interferometry provides extremely sensitive and accurate tools for the measurement of inertial forces. Operation of atom interferometers in microgravity is expected to enhance the performance of such sensors. This paper presents two possible implementations of a dual {sup 85}Rb-{sup 87}Rb atom interferometer to perform differential gravity measurements in space, with the primary goal to test the Weak Equivalence Principle. The proposed scheme is in the framework of two projects of the European Space Agency, namely Q-WEP and STE-QUEST. The paper describes the baseline experimental configuration, and discusses the technology readiness, noise and error budget for the two proposed experiments.

  1. IMAP: Interferometry for Material Property Measurement in MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, B.D.; Miller, S.L.; de Boer, M.P.

    1999-03-10

    An interferometric technique has been developed for non-destructive, high-confidence, in-situ determination of material properties in MEMS. By using interferometry to measure the full deflection curves of beams pulled toward the substrate under electrostatic loads, the actual behavior of the beams has been modeled. No other method for determining material properties allows such detailed knowledge of device behavior to be gathered. Values for material properties and non-idealities (such as support post compliance) have then been extracted which minimize the error between the measured and modeled deflections. High accuracy and resolution have been demonstrated, allowing the measurements to be used to enhance process control.

  2. Theory of decoherence in Bose-Einstein condensate interferometry

    International Nuclear Information System (INIS)

    Dalton, B J

    2007-01-01

    A full treatment of decoherence and dephasing effects in BEC interferometry has been developed based on using quantum correlation functions for treating interferometric effects. The BEC is described via a phase space distribution functional of the Wigner type for the condensate modes and the positive P type for the non-condensate modes. Ito equations for stochastic condensate and non-condensate field functions replace the functional Fokker-Planck equation for the distribution functional and stochastic averages of field function products determine the quantum correlation functions

  3. Recent advances in X-ray and neutron interferometry

    International Nuclear Information System (INIS)

    Bonse, U.

    1988-01-01

    Since their advent interferometry with X-rays and neutrons have been developed steadily. A number of excellent reviews is covering the development up to about five years ago. Advances since then are treated in this review. Topics included are: Understanding of angstrom wave interferometers, theory of operation, types, contrast, complementarity, strategies and refinement of measurement, nonlinear Fizeau effect with neutrons, action of gravity and inertia of neutron phase, interferometers with separated crystals, interferometer combining X-ray and optical operation, interferometer combining X-ray and neutron operation. (orig.)

  4. Displacement interferometry with stabilization of wavelength in air

    Czech Academy of Sciences Publication Activity Database

    Lazar, Josef; Holá, Miroslava; Číp, Ondřej; Čížek, Martin; Hrabina, Jan; Buchta, Zdeněk

    2012-01-01

    Roč. 20, č. 25 (2012), s. 27830-27837 ISSN 1094-4087 R&D Projects: GA ČR GA102/09/1276; GA ČR GPP102/11/P820; GA TA ČR TA02010711; GA TA ČR TE01020233; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : interferometry * instrumentation * measurement, and metrology Subject RIV: BH - Optics, Masers, Laser s Impact factor: 3.546, year: 2012

  5. Speckle Interferometry with the OCA Kuhn 22" Telescope

    Science.gov (United States)

    Wasson, Rick

    2018-04-01

    Speckle interferometry measurements of double stars were made in 2015 and 2016, using the Kuhn 22-inch classical Cassegrain telescope of the Orange County Astronomers, a Point Grey Blackfly CMOS camera, and three interference filters. 272 observations are reported for 177 systems, with separations ranging from 0.29" to 2.9". Data reduction was by means of the REDUC and Speckle Tool Box programs. Equipment, observing procedures, calibration, data reduction, and analysis are described, and unusual results for 11 stars are discussed in detail.

  6. Modelling of a holographic interferometry based calorimeter for radiation dosimetry

    Science.gov (United States)

    Beigzadeh, A. M.; Vaziri, M. R. Rashidian; Ziaie, F.

    2017-08-01

    In this research work, a model for predicting the behaviour of holographic interferometry based calorimeters for radiation dosimetry is introduced. Using this technique for radiation dosimetry via measuring the variations of refractive index due to energy deposition of radiation has several considerable advantages such as extreme sensitivity and ability of working without normally used temperature sensors that disturb the radiation field. We have shown that the results of our model are in good agreement with the experiments performed by other researchers under the same conditions. This model also reveals that these types of calorimeters have the additional and considerable merits of transforming the dose distribution to a set of discernible interference fringes.

  7. Holographic interferometry using a digital photo-camera

    International Nuclear Information System (INIS)

    Sekanina, H.; Hledik, S.

    2001-01-01

    The possibilities of running digital holographic interferometry using commonly available compact digital zoom photo-cameras are studied. The recently developed holographic setup, suitable especially for digital photo-cameras equipped with an un detachable object lens, is used. The method described enables a simple and straightforward way of both recording and reconstructing of a digital holographic interferograms. The feasibility of the new method is verified by digital reconstruction of the interferograms acquired, using a numerical code based on the fast Fourier transform. Experimental results obtained are presented and discussed. (authors)

  8. Frequency Noise Properties of Lasers for Interferometry in Nanometrology

    Czech Academy of Sciences Publication Activity Database

    Hrabina, Jan; Lazar, Josef; Holá, Miroslava; Číp, Ondřej

    2013-01-01

    Roč. 13, č. 2 (2013), s. 2206-2219 ISSN 1424-8220 R&D Projects: GA ČR GPP102/11/P820; GA ČR GA102/09/1276; GA AV ČR KAN311610701; GA MŠk ED0017/01/01; GA MŠk(CZ) LC06007 Institutional support: RVO:68081731 Keywords : nanometrology * laser noise * interferometry * nanopositioning * AFM Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.048, year: 2013

  9. Application of linear systems theory to characterize coherence scanning interferometry

    Science.gov (United States)

    Mandal, Rahul; Palodhi, Kanik; Coupland, Jeremy; Leach, Richard; Mansfield, Daniel

    2012-04-01

    This paper considers coherence scanning interferometry as a linear filtering operation that is characterised by a point spread function in the space domain or equivalently a transfer function in the frequency domain. The applicability of the theory is discussed and the effects of these functions on the measured interferograms, and their influence on the resulting surface measurements, are described. The practical characterisation of coherence scanning interferometers using a spherical reference artefact is then considered and a new method to compensate measurement errors, based on a modified inverse filter, is demonstrated.

  10. 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...

  11. Interferometry in the era of time-domain astronomy

    Science.gov (United States)

    Schaefer, Gail H.; Cassan, Arnaud; Gallenne, Alexandre; Roettenbacher, Rachael M.; Schneider, Jean

    2018-04-01

    The physical nature of time variable objects is often inferred from photometric light-curves and spectroscopic variations. Long-baseline optical interferometry has the power to resolve the spatial structure of time variable sources directly in order to measure their physical properties and test the physics of the underlying models. Recent interferometric studies of variable objects include measuring the angular expansion and spatial structure during the early stages of novae outbursts, studying the transits and tidal distortions of the components in eclipsing and interacting binaries, measuring the radial pulsations in Cepheid variables, monitoring changes in the circumstellar discs around rapidly rotating massive stars, and imaging starspots. Future applications include measuring the image size and centroid displacements in gravitational microlensing events, and imaging the transits of exoplanets. Ongoing and upcoming photometric surveys will dramatically increase the number of time-variable objects detected each year, providing many potential targets to observe interferometrically. For short-lived transient events, it is critical for interferometric arrays to have the flexibility to respond rapidly to targets of opportunity and optimize the selection of baselines and beam combiners to provide the necessary resolution and sensitivity to resolve the source as its brightness and size change. We discuss the science opportunities made possible by resolving variable sources using long baseline optical interferometry.

  12. Multi-link laser interferometry architecture for interspacecraft displacement metrology

    Science.gov (United States)

    Francis, Samuel P.; Lam, Timothy T.-Y.; McClelland, David E.; Shaddock, Daniel A.

    2017-09-01

    Targeting a future Gravity Recovery and Climate Experiment (GRACE) mission, we present a new laser interferometry architecture that can be used to recover the displacement between two spacecraft from multiple interspacecraft measurements. We show it is possible to recover the displacement between the spacecraft centers of mass in post-processing by forming linear combinations of multiple, spatially offset, interspacecraft measurements. By canceling measurement error due to angular misalignment of the spacecraft, we remove the need for precise placement or alignment of the interferometer, potentially simplifying spacecraft integration. To realize this multi-link architecture, we propose an all-fiber interferometer, removing the need for any ultrastable optical components such as the GRACE Follow-On mission's triple mirror assembly. Using digitally enhanced heterodyne interferometry, the number of links is readily scalable, adding redundancy to our measurement. We present the concept, an example multi-link implementation and the signal processing required to recover the center of mass displacement from multiple link measurements. Finally, in a simulation, we analyze the limiting noise sources in a 9 link interferometer and ultimately show we can recover the 80nm/√{Hz} displacement sensitivity required by the GRACE Follow-On laser ranging interferometer.

  13. Multi-link laser interferometry architecture for interspacecraft displacement metrology

    Science.gov (United States)

    Francis, Samuel P.; Lam, Timothy T.-Y.; McClelland, David E.; Shaddock, Daniel A.

    2018-03-01

    Targeting a future Gravity Recovery and Climate Experiment (GRACE) mission, we present a new laser interferometry architecture that can be used to recover the displacement between two spacecraft from multiple interspacecraft measurements. We show it is possible to recover the displacement between the spacecraft centers of mass in post-processing by forming linear combinations of multiple, spatially offset, interspacecraft measurements. By canceling measurement error due to angular misalignment of the spacecraft, we remove the need for precise placement or alignment of the interferometer, potentially simplifying spacecraft integration. To realize this multi-link architecture, we propose an all-fiber interferometer, removing the need for any ultrastable optical components such as the GRACE Follow-On mission's triple mirror assembly. Using digitally enhanced heterodyne interferometry, the number of links is readily scalable, adding redundancy to our measurement. We present the concept, an example multi-link implementation and the signal processing required to recover the center of mass displacement from multiple link measurements. Finally, in a simulation, we analyze the limiting noise sources in a 9 link interferometer and ultimately show we can recover the 80 {nm}/√{ {Hz}} displacement sensitivity required by the GRACE Follow-On laser ranging interferometer.

  14. Atomic interactions in precision interferometry using Bose-Einstein condensates

    International Nuclear Information System (INIS)

    Jamison, Alan O.; Gupta, Subhadeep; Kutz, J. Nathan

    2011-01-01

    We present theoretical tools for predicting and reducing the effects of atomic interactions in Bose-Einstein condensate (BEC) interferometry experiments. To address mean-field shifts during free propagation, we derive a robust scaling solution that reduces the three-dimensional Gross-Pitaevskii equation to a set of three simple differential equations valid for any interaction strength. To model the other common components of a BEC interferometer--condensate splitting, manipulation, and recombination--we generalize the slowly varying envelope reduction, providing both analytic handles and dramatically improved simulations. Applying these tools to a BEC interferometer to measure the fine structure constant, α[S. Gupta, K. Dieckmann, Z. Hadzibabic, and D. E. Pritchard, Phys. Rev. Lett. 89, 140401 (2002)], we find agreement with the results of the original experiment and demonstrate that atomic interactions do not preclude measurement to better than part-per-billion accuracy, even for atomic species with relatively large scattering lengths. These tools help make BEC interferometry a viable choice for a broad class of precision measurements.

  15. Algorithms and Array Design Criteria for Robust Imaging in Interferometry

    Science.gov (United States)

    Kurien, Binoy George

    Optical interferometry is a technique for obtaining high-resolution imagery of a distant target by interfering light from multiple telescopes. Image restoration from interferometric measurements poses a unique set of challenges. The first challenge is that the measurement set provides only a sparse-sampling of the object's Fourier Transform and hence image formation from these measurements is an inherently ill-posed inverse problem. Secondly, atmospheric turbulence causes severe distortion of the phase of the Fourier samples. We develop array design conditions for unique Fourier phase recovery, as well as a comprehensive algorithmic framework based on the notion of redundant-spaced-calibration (RSC), which together achieve reliable image reconstruction in spite of these challenges. Within this framework, we see that classical interferometric observables such as the bispectrum and closure phase can limit sensitivity, and that generalized notions of these observables can improve both theoretical and empirical performance. Our framework leverages techniques from lattice theory to resolve integer phase ambiguities in the interferometric phase measurements, and from graph theory, to select a reliable set of generalized observables. We analyze the expected shot-noise-limited performance of our algorithm for both pairwise and Fizeau interferometric architectures and corroborate this analysis with simulation results. We apply techniques from the field of compressed sensing to perform image reconstruction from the estimates of the object's Fourier coefficients. The end result is a comprehensive strategy to achieve well-posed and easily-predictable reconstruction performance in optical interferometry.

  16. Electron density interferometry measurement in laser-matter interaction

    International Nuclear Information System (INIS)

    Popovics-Chenais, C.

    1981-05-01

    This work is concerned with the laser-interferometry measurement of the electronic density in the corona and the conduction zone external part. Particularly, it is aimed at showing up density gradients and at their space-time localization. The first chapter recalls the density profile influence on the absorption principal mechanisms and the laser energy transport. In chapter two, the numerical and analytical hydrodynamic models describing the density profile are analysed. The influence on the density profile of the ponderomotive force associated to high oscillating electric fields is studied, together with the limited thermal conduction and suprathermal electron population. The mechanism action, in our measurement conditions, is numerically simulated. Calculations are made with experimental parameters. The measurement interaction conditions, together with the diagnostic method by high resolution laser interferometry are detailed. The results are analysed with the help of numerical simulation which is the experiment modeling. An overview of the mechanisms shown up by interferometric measurements and their correlation with other diagnostics is the conclusion of this work [fr

  17. Complex interferometry potential in case of sufficiently stable diagnostic system

    Science.gov (United States)

    Kalal, M.

    2016-06-01

    Classical interferometry is one of the key methods among active optical diagnostics. Its more advanced version, which allows recording and subsequent reconstruction of up to three sets of data using just one data object —a complex interferogram—was developed in the past and became known as complex interferometry. Employing this diagnostics, not only the usual phase shift, but also the amplitude of the probing beam as well as the fringe contrast (leading directly to the phase shift time derivative) can be reconstructed simultaneously from such a complex interferogram. In this paper it will be demonstrated that even in the case of a not particularly good diagnostic beam quality these three quantities can be reconstructed with a high degree of accuracy provided both the diagnostic beam as well as the corresponding optical line feature a reasonable stability. Such stability requirement is important as in an ideal case four shots need to be gradually recorded (one by one): the signal complex interferogram, the reference interferogram as well as the intensity structures of the signal and reference part of the diagnostic beam. Two examples of complex interferograms obtained in experiments will be analyzed: the laser produced plasma (spark in the air) and the high pressure gas jet. A general ray-tracing based iterative algorithm will be outlined in order to increase a precision of the index of refraction spatial profile taking into account refraction effects (omitted in the Abel inversion) and employing the original reconstructed phase shift and amplitude.

  18. Matter wave interferometry as a tool for molecule metrology

    Science.gov (United States)

    Gerlich, Stefan; Gring, Michael; Ulbricht, Hendrik; Hornberger, Klaus; Tuexen, Jens; Mayor, Marcel; Arndt, Markus

    2009-03-01

    Kapitza-Dirac-Talbot-Lau interferometry (KDTLI) has recently been established as an ideal method to perform quantum matter wave experiments with large, highly polarizable molecules in an unprecedented mass range of beyond 1000 atomic mass units [1]. Since the interference visibility reveals important information on the properties of the examined particles, such as their mass and polarizability, we identified KDTLI as a valuable tool for precision metrology. We demonstrate that quantum interferometry can therefore also serve as a powerful complement to mass spectrometry [2], in particular in cases where fragmentation may occur in the detector. Our new method is applicable to a wide range of molecules and is particularly valuable for characterizing neutral molecular beams. [1] S. Gerlich, L. Hackerm"uller, K. Hornberger, A. Stibor, H. Ulbricht, M. Gring, F. Goldfarb, T. Savas, M. M"uri, M. Mayor, M. Arndt, Nat. Phys. 2007, 3, 711 - 715. [2] Stefan Gerlich, Michael Gring, Hendrik Ulbricht, Klaus Hornberger, Jens T"uxen, Marcel Mayor, and Markus Arndt, Angew. Chem. Int. Ed. 2008, 47, 6195 - 6198.

  19. 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.

  20. 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)

  1. 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.)

  2. Refractometry and interferometry in chemical analysis; Refractometrie et interferometrie en analyse chimique

    Energy Technology Data Exchange (ETDEWEB)

    Veret, C. [Faculte des Sciences de Paris, 75 (France)

    2000-03-01

    In vacuum, an electromagnetic radiation is propagated at a constant velocity. But, when it has to pass through a physical medium, it is submitted to different interactions (for instance: absorption, diffusion, refraction, polarization, dispersion, fluorescence) which lead to a modification of its propagation. In the frequency ranges of the radiation for which the absorption is not very important, the modifications of the propagation velocity of a radiation can bring data on the nature and/or the physical conditions (pressure, temperature) of a medium, whatever its state be: gas, liquid or solid. Thus, the absolute refractive index of a medium in relation to vacuum is defined as the ratio c/v of the propagation velocity c of a monochromatic electromagnetic radiation in vacuum at its velocity v in this medium. The photonic refractometry (field of ultraviolet, visible and infrared radiations) is the set of the measure techniques of the refractive indexes having a role in chemical analysis. The refractometry measures can only be applied to media which are optically transparent. After having described these techniques, the author presents their uses in chemical analysis. (O.M.)

  3. High sensitivity Moire interferometry with phase shifting at nano resolution

    Science.gov (United States)

    Chen, Bicheng

    Due to insatiate demand for miniaturization of electronics, there is a need for new techniques to measure full-field strain at micro-scale structures. In addition, Micro-Electronic-Mechanical-Systems (MEMS) require a high resolution and high sensitivity material property characterization technique. In this study, a theoretic model for a high sensitivity Moire Interferometry (MI) for measuring nano-scale strain field has been developed. The study also includes the application of the proposed measurement technique for the study of reliability of next generation nano-electronics/power electronics. The study includes both theoretical and experimental work. In the theoretical part, a far field modeling of a Moire Interferometer (MI) using the mode decomposition method is proposed according to the analytical formulation from the scalar diffraction theory. The wave propagation within the defined MI far field domain is solved analytically for a single frequency surface relieved grating structure following the Rayleigh-Sommerfeld formulation under the paraxial approximation. It is shown that the far-field electrical field and the intensity interferogram can be calculated using the mode decomposition method. Furthermore, the near-field (propagation distance EM) theory; and the EM fields are simulated in a few microns region above the surface of the diffraction grating. The study shows that there is a strong correlation (correlation factor R = 0.869) of spatial frequency response between EM field and strain field at the nanoscale. Experimentally, a 164 nm/pixel spatial resolution Moire Interferometer with automated full strain field calculation is proposed. Accurate full strain field maps are generated automatically by a combination of phase shifting technique (temporal data redundancy) and Continuous Wavelet Transform (CWT) (spatial data redundancy). A thermal experiment on BGA packaging is used to demonstrate the advantages of the proposed new design. To enhance the

  4. 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.

  5. Seismic Interferometry Using Persistent Noise Sources for Temporal Subsurface Monitoring

    Science.gov (United States)

    Dales, Philippe; Audet, Pascal; Olivier, Gerrit

    2017-11-01

    In passive source seismology, seismic interferometry typically refers to the cross correlation of ambient noise to construct an estimate of the Green's function between sensors. The presence of persistent natural and/or anthropogenic sources can bias or prevent the retrieval of these estimated Green's functions. Here we show how these strong persistent sources can be used to measure small changes in the medium between a source and either (or both) source-sensor pairs. The method relies on localizing the sources and using this information to identify and select cross-correlation functions for each source of interest. We illustrate this method by monitoring growth of a block cave at an underground mine using three nearly continuously operating ore crushers which dominate the wavefield. This technique should work equally well in natural environments using sources such as volcanic tremor, hydrothermal bubble cavitation, and microseisms.

  6. Application of resonance interferometry and holography for plasma diagnostics

    International Nuclear Information System (INIS)

    Drejden, G.V.; Zajdel', A.N.; Ostrovksya, G.V.; Ostrovskij, Yu.I.; Pobedonostseva, N.A.; Tanin, L.V.; Filippov, V.N.; Shedova, E.N.

    1975-01-01

    Methods of resonance interferometry and holography are discussed, and limits of their applications are considered. Resonance methods are distinguished by high sensitivity and selectivity in the comparison with conventional interferometric and holographic methods. Methods discussed are mainly applied in a comparatively dense plasma, although in some cases it can determine atom densities up to Nsub(a) = 10 9 cm -3 and lower. In the case of the plasma with Nsub(e) = 10 18 -10 19 cm -3 a minimal atom density observable is near Nsub(a) = 10 14 cm -3 . Requirements light sources are specified, and investigation methods are described. For potassium, sodium, lithium, and hydrogen plasma as examples the applicability of these methods is illustrated: atom and electron density are determined, and the plasma dynamics is investigated

  7. First measurement of laser wakefield oscillations by longitudinal interferometry

    International Nuclear Information System (INIS)

    Siders, C.W.; Le Blanc, S.P.; Rau, B.; Fisher, D.; Tajima, T.; Downer, M.C.; Babine, A.; Stepanov, A.; Sergeev, A.

    1997-01-01

    In this paper femtosecond time resolved measurements of the longitudinal and radial structure of laser wakefield oscillations using an all optical technique known as interferometric photon acceleration or longitudinal interferometry. In the experiment a probe pulse co-propagates behind an intense pulse (I=3x10 17 W/cm 2 , λ=0.8μm, τ=100fs) tightly focused in a helium gas. As the pump pulse ionizes the gas and exerts ponderomotive pressure on the resulting plasma, the probe pulses experiences electron density gradients behind the pump pulse which cause both DC phase shifts as well as spectral shifting of the probe pulse frequency spectrum. In order to detect the small changes in the frequency and phase with femtosecond resolution, our photon accelerator diagnostic uses multiple, temporally separated probe pulses which produce frequency domain interferograms. (AIP) copyright 1997 American Institute of Physics

  8. Demystifying back scatter interferometry: a sensitive refractive index detector

    DEFF Research Database (Denmark)

    Jepsen, Søren Terpager; Jørgensen, Thomas Martini; Trydal, Torleif

    2014-01-01

    acting like a common-path interferometer. METHODS: A HeNe laser is directed at a glass capillary with inner diameter of 1.4 mm and reflected light from air/glass and liquid/glass interfaces interfere to form an RI dependent intensity fringe pattern at a CCD detector. The fringe shift relative......BACKGROUND: Back Scatter Interferometry (BSI) is a sensitive method for detecting changes of the refractive index (RI) in small capillaries. The method was originally developed as an off-axial column detector for use in Liquid Chromatography or Capillary Electrophoresis systems, but it has been...... a set of NaCl standard solutions. RESULTS: Ray-tracing show that the basic interference pattern recorded with BSI can be fully described by two beams, one reflected from the surface of the capillary and a beam reflected from the back of the capillary wall. In accordance we find that the interferometric...

  9. Multi-image oil-film interferometry skin friction measurements

    International Nuclear Information System (INIS)

    Naughton, J W; Hind, M D

    2013-01-01

    The benefits of analyzing multiple interferogram images obtained using oil-film interferometry in order to determine wall shear stress are assessed. Both dual- and multi-image analysis approaches are implemented and compared to standard single interferogram approaches. Each of the analysis approaches is derived from the thin oil-film equation. To assess the different implementations, both experimental interferograms and simulated oil films are used. The simulations determine the oil-film height as a function of space and time by solving the thin oil-film equation subject to a known wall shear stress distribution, whereas experimental interferograms were obtained in a turbulent flat plate boundary layer. The results of analyzing these data with the three different analysis approaches suggest that they all work equally well when test conditions are approximately steady. For tunnels with long transients at startup or when multiple test conditions need to be measured in a single run, the multi-image approach is recommended. (paper)

  10. Point source atom interferometry with a cloud of finite size

    Energy Technology Data Exchange (ETDEWEB)

    Hoth, Gregory W., E-mail: gregory.hoth@nist.gov; Pelle, Bruno; Riedl, Stefan; Kitching, John; Donley, Elizabeth A. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

    2016-08-15

    We demonstrate a two axis gyroscope by the use of light pulse atom interferometry with an expanding cloud of atoms in the regime where the cloud has expanded by 1.1–5 times its initial size during the interrogation. Rotations are measured by analyzing spatial fringe patterns in the atom population obtained by imaging the final cloud. The fringes arise from a correlation between an atom's initial velocity and its final position. This correlation is naturally created by the expansion of the cloud, but it also depends on the initial atomic distribution. We show that the frequency and contrast of these spatial fringes depend on the details of the initial distribution and develop an analytical model to explain this dependence. We also discuss several challenges that must be overcome to realize a high-performance gyroscope with this technique.

  11. All-optical optoacoustic microscope based on wideband pulse interferometry.

    Science.gov (United States)

    Wissmeyer, Georg; Soliman, Dominik; Shnaiderman, Rami; Rosenthal, Amir; Ntziachristos, Vasilis

    2016-05-01

    Optical and optoacoustic (photoacoustic) microscopy have been recently joined in hybrid implementations that resolve extended tissue contrast compared to each modality alone. Nevertheless, the application of the hybrid technique is limited by the requirement to combine an optical objective with ultrasound detection collecting signal from the same micro-volume. We present an all-optical optoacoustic microscope based on a pi-phase-shifted fiber Bragg grating (π-FBG) with coherence-restored pulsed interferometry (CRPI) used as the interrogation method. The sensor offers an ultra-small footprint and achieved higher sensitivity over piezoelectric transducers of similar size. We characterize the spectral bandwidth of the ultrasound detector and interrogate the imaging performance on phantoms and tissues. We show the first optoacoustic images of biological specimen recorded with π-FBG sensors. We discuss the potential uses of π-FBG sensors based on CRPI.

  12. Demonstration of SU(2)-symmetry by neutron interferometry

    International Nuclear Information System (INIS)

    Rauch, H.; Zeilinger, A.

    1981-01-01

    Neutron interferometry provides a direct test of the 4π-symmetry of a fermion wave function. The experiments performed with perfect crystal interferometers to demonstrate that SU(2)-symmetry property are reviewed. The measured periodicity value of 716.8 +- 3.8 degrees, which is the most precise one obtained up to now, is in good agreement with theoretical prediction. Effects are discussed which may give rise to deviations of the experimental result from the 4π value. Furthermore, an account of epistemological aspects is given relating to the question of the operational applicability of the term rotation in the interpretation of the experiments. Finally, proposals for new, more precise, experiments are made. Some of these experiments may have particular relevance in the context of considerations of a breaking of SU(2) symmetry under strong interaction

  13. Super-virtual refraction interferometry: an engineering field data example

    KAUST Repository

    Hanafy, Sherif M.

    2012-10-01

    The theory of super-virtual refraction interferometry (SVI) was recently developed to enhance the signal-to-noise ratio (SNR) of far-offset traces in refraction surveys. This enhancement of the SNR is proportional to √N and can be as high as N if an iterative procedure is used. Here N is the number of post-critical shot positions that coincides with the receiver locations. We now demonstrate the SNR enhancement of super-virtual refraction traces for one engineering-scale synthetic data and two field seismic data sets. The field data are collected over a normal fault in Saudi Arabia. Results show that both the SNR of the super-virtual data set and the number of reliable first-arrival traveltime picks are significantly increased. © 2012 European Association of Geoscientists & Engineers.

  14. Collinear phase matching for second harmonic generation using conoscopic interferometry

    Science.gov (United States)

    De, A.; Puri, A.

    2010-04-01

    The problem of finding phase-matching directions in noncentrosymmetric biaxial crystals is simplified here by the use of Conoscopic interferometry. Based on vector relations for wave propagation in birefringent media and solutions to phase-matching equations, we show that phase matching directions can be located on the conoscopic interferograms and that fringe numbers for dark-isochromes can be used as a guide to find phase-matching directions for a biaxial crystal. This technique can be generalized and extended to any anisotropic crystal. We have demonstrated this method for the particular case of a biaxial KTiOPO4 crystal, where it is found to be particularly suitable for finding the optimum-phase-matching directions.

  15. Very Long Baseline Interferometry: Dependencies on Frequency Stability

    Science.gov (United States)

    Nothnagel, Axel; Nilsson, Tobias; Schuh, Harald

    2018-04-01

    Very Long Baseline Interferometry (VLBI) is a differential technique observing radiation of compact extra-galactic radio sources with pairs of radio telescopes. For these observations, the frequency standards at the telescopes need to have very high stability. In this article we discuss why this is, and we investigate exactly how precise the frequency standards need to be. Four areas where good clock performance is needed are considered: coherence, geodetic parameter estimation, correlator synchronization, and UT1 determination. We show that in order to ensure the highest accuracy of VLBI, stability similar to that of a hydrogen maser is needed for time-scales up to a few hours. In the article, we are considering both traditional VLBI where extra-galactic radio sources are observed, as well as observation of man-made artificial radio sources emitted by satellites or spacecrafts.

  16. Phase retrieval for interferometry imaging from microlens array

    Science.gov (United States)

    Zhu, Zhihao; Qiu, Minpu

    2018-03-01

    It was considered to get interferometry data from microlens array and reconstruct initial image through it directly, while which used to be taken to calculate the phase difference to get the structure of objects in measurement technology. It broke through the depend of resolution improvement on the size of apertures, reducing the volume of image system vastly. Nevertheless, on account of the phase deficiency, this method could not show the details well enough to be generally used in measurement and control systems. Through support estimation of the target, with the feature extraction technology, the deconvolution function could be got, by which the sidelobe and pinniform structure in the "ditry" image caused by the lack of frequency could be eliminated, and phase retrieval was done. Simulation did the reconstruction experiment, yet had got relatively good detail presentations.

  17. Frequency selection for coda wave interferometry in concrete structures.

    Science.gov (United States)

    Fröjd, Patrik; Ulriksen, Peter

    2017-09-01

    This study contributes to the establishment of frequency recommendations for use in coda wave interferometry structural health monitoring (SHM) systems for concrete structures. To this end, codas with widely different central frequencies were used to detect boreholes with different diameters in a large concrete floor slab, and to track increasing damage in a small concrete beam subjected to bending loads. SHM results were obtained for damage that can be simulated by drilled holes on the scale of a few mm or microcracks due to bending. These results suggest that signals in the range of 50-150kHz are suitable in large concrete structures where it is necessary to account for the high attenuation of high-frequency signals. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Interferometry and MHD turbulence measurements in toroidal pinches

    International Nuclear Information System (INIS)

    Dutt, T.L.; Evans, D.E.; Wilcock, P.D.

    1976-01-01

    A 10.6 micron interferometer produced 2 to 3 good quality fringes in the HBTX plasma. There is substantial agreement in the electron densities determined by interferometry and by Thomson scattering, but since the former is an absolute measurement and is systematically lower than the Thomson scattering values, the latter may be too great by about 35%. In RF Pinches, turbulence associated with the instability deflects the beam and corrupts the interferogram. However, if the intensity fluctuations induced in this beam by the turbulence, are measured, as is done in the second experiment performed in the FRSX plasma with a HCN laser, the frequency spectrum of the turbulence can be deduced. In this plasma, rms fluctuations in the density were measured by this means to be 20%, and the dominant frequency of the fluctuations multiplied by the tube diameter was approximately Alfven speed, favouring an interpretation of the gross turbulence in this plasma in terms of Alfen waves. (U.K.)

  19. Transverse beam profile reconstruction using synchrotron radiation interferometry

    Directory of Open Access Journals (Sweden)

    L. Torino

    2016-12-01

    Full Text Available Transverse beam size measurements in new generation of synchrotron light sources is a challenging task due to their characteristic small beam emittances and low couplings. Since the late 1990s, synchrotron radiation interferometry (SRI has been used in many accelerators to measure the beam size through the analysis of the spatial coherence of the synchrotron light. However, the standard SRI using a double-aperture system provides the beam size projection in a given direction. For this reason, the beam shape is not fully characterized because information about possible transverse beam tilts is not determined. In this report, we describe a technique to fully reconstruct the transverse beam profile based on a rotating double-pinhole mask, together with experimental results obtained at ALBA under different beam couplings. We also discuss how this method allows us to infer ultrasmall beam sizes in case of limitations of the standard SRI.

  20. Imaging and Measuring Electron Beam Dose Distributions Using Holographic Interferometry

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.

    1975-01-01

    Holographic interferometry was used to image and measure ionizing radiation depth-dose and isodose distributions in transparent liquids. Both broad and narrowly collimated electron beams from accelerators (2–10 MeV) provided short irradiation times of 30 ns to 0.6 s. Holographic images...... and measurements of absorbed dose distributions were achieved in liquids of various densities and thermal properties and in water layers thinner than the electron range and with backings of materials of various densities and atomic numbers. The lowest detectable dose in some liquids was of the order of a few k......Rad. The precision limits of the measurement of dose were found to be ±4%. The procedure was simple and the holographic equipment stable and compact, thus allowing experimentation under routine laboratory conditions and limited space....

  1. Adaptive Interferometry Sensor for Detection of Nanoscale Displacements

    Directory of Open Access Journals (Sweden)

    Roman V. ROMASHKO

    2014-11-01

    Full Text Available In this work we present an adaptive holographic interferometry sensing system for measurement of nanoscale displacements of micro- and macro-objects. The system is based on using dynamic hologram continuously recorded in photorefractive CdTe crystal. Theoretical limit for displacement detection which can be provided by the system is 0.1 nm. It is experimentally demonstrated that system is able to detect a displacement from 0.7 nm up to 266 nm in linear regime. We also present theoretical model of adaptive interferometer operation which take into account a displacement speed. Due to its adaptive properties the measurement system can be used for inspection of sub-micro-scale objects with arbitrary shape and surface profile.

  2. P-REx: The Piston Reconstruction Experiment for infrared interferometry

    Science.gov (United States)

    Widmann, Felix; Pott, Jörg-Uwe; Velasco, Sergio

    2018-03-01

    For sensitive infrared interferometry, it is crucial to control the differential piston evolution between the used telescopes. This is classically done by the use of a fringe tracker. In this work, we develop a new method to reconstruct the temporal piston variation from the atmosphere, by using real-time data from adaptive optics (AO) wavefront sensing: the Piston Reconstruction Experiment (P-REx). In order to understand the principle performance of the system in a realistic multilayer atmosphere, it is first extensively tested in simulations. The gained insights are then used to apply P-REx to real data, in order to demonstrate the benefit of using P-REx as an auxiliary system in a real interferometer. All tests show positive results, which encourages further research and eventually a real implementation. Especially, the tests on on-sky data showed that the atmosphere is, under decent observing conditions, sufficiently well structured and stable, in order to apply P-REx. It was possible to conveniently reconstruct the piston evolution in two-thirds of the data sets from good observing conditions (r0 ˜ 30 cm). The main conclusion is that applying the piston reconstruction in a real system would reduce the piston variation from around 10 μm down to 1-2 μm over time-scales of up to two seconds. This suggests an application for mid-infrared interferometry, for example for MATISSE at the very large telescope interferometer or the large binocular telescope interferometer. P-REx therefore provides the possibility to improve interferometric measurements without the need for more complex AO systems than already in regular use at 8-m-class telescopes.

  3. Persistent Scatterer Interferometry (PSI Technique for Landslide Characterization and Monitoring

    Directory of Open Access Journals (Sweden)

    Nicola Casagli

    2013-03-01

    Full Text Available : The measurement of landslide superficial displacement often represents the most effective method for defining its behavior, allowing one to observe the relationship with triggering factors and to assess the effectiveness of the mitigation measures. Persistent Scatterer Interferometry (PSI represents a powerful tool to measure landslide displacement, as it offers a synoptic view that can be repeated at different time intervals and at various scales. In many cases, PSI data are integrated with in situ monitoring instrumentation, since the joint use of satellite and ground-based data facilitates the geological interpretation of a landslide and allows a better understanding of landslide geometry and kinematics. In this work, PSI interferometry and conventional ground-based monitoring techniques have been used to characterize and to monitor the Santo Stefano d’Aveto landslide located in the Northern Apennines, Italy. This landslide can be defined as an earth rotational slide. PSI analysis has contributed to a more in-depth investigation of the phenomenon. In particular, PSI measurements have allowed better redefining of the boundaries of the landslide and the state of activity, while the time series analysis has permitted better understanding of the deformation pattern and its relation with the causes of the landslide itself. The integration of ground-based monitoring data and PSI data have provided sound results for landslide characterization. The punctual information deriving from inclinometers can help in defining the actual location of the sliding surface and the involved volumes, while the measuring of pore water pressure conditions or water table level can suggest a correlation between the deformation patterns and the triggering factors.

  4. Surface deformation of Taipei basin detected by Differential SAR Interferometry

    Science.gov (United States)

    Chen, Y.; Chang, C.; Yen, J.; Lin, M.

    2006-12-01

    Taiwan island is located between the southeastern periphery of the Eurasian plate and the Philippine Sea plate. The two converging plates produced very active tectonics, and can be seen by the high seismicity and deformation rate. Taipei, the highest populated area, center of politics, and economics in Taiwan, is in Taipei basin at the northern part of the island. There are several faults in and surrounding the basin, and the city is threatened with a high geological hazard potential that we should keep monitoring the crustal deformation to prevent and mitigate the disaster effect. The aims of our study is to apply the DInSAR technique to determine the surface deformation of Taipei basin area, and discussing the relation between the manifestation of deformation and the tectonically active region, Shanjiao fault. In the past few years, Differential SAR Interferometry (DInSAR) has been proved to be a powerful technique for monitoring the neotectonic activities and natural hazards. High spatial sampling rate of DInSAR technique allows studies of surface deformations with centimeter accuracy. In this area, we used ERS-1/2 SAR images acquired from 1993 to 2005 to generate 10 differential interferograms and processed the data using DIAPASON developed by CNES and SRTM global DEM.From our results, the deformation rate in Taipei is generally high in the western end of the basin along the Shanjiao fault and decrease eastward, while the subsidence center often appeared in the center of the Taipei basin. The neotectonic activity of the Shanjiao fault appeared to be insignificant by itself but it seemed to separate the subsiding basin from the surrounding areas. Further comparison between our DInSAR results and isopach of the Taipei basin revealed that the subsidence centers appeared in the interferograms did not coincide with the location where the sediments are thickest. Our results from differential interferometry will be compared to other geodetic measurements such as the

  5. Drosophila Protein interaction Map (DPiM)

    OpenAIRE

    Guruharsha, K.G.; Obar, Robert A.; Mintseris, Julian; Aishwarya, K.; Krishnan, R.T.; VijayRaghavan, K.; Artavanis-Tsakonas, Spyros

    2012-01-01

    Proteins perform essential cellular functions as part of protein complexes, often in conjunction with RNA, DNA, metabolites and other small molecules. The genome encodes thousands of proteins but not all of them are expressed in every cell type; and expressed proteins are not active at all times. Such diversity of protein expression and function accounts for the level of biological intricacy seen in nature. Defining protein-protein interactions in protein complexes, and establishing the when,...

  6. The Balloon Experimental Twin Telescope for Infrared Interferometry : Returning to Flight

    Data.gov (United States)

    National Aeronautics and Space Administration — The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter far-infrared (30-90 micron) Michelson interferometer, designed to fly on a...

  7. Neutron interferometry lessons in experimental quantum mechanics, wave-particle duality, and entanglement

    CERN Document Server

    Rauch, Helmut

    2015-01-01

    The quantum interference of de Broglie matter waves is probably one of the most startling and fundamental aspects of quantum mechanics. It continues to tax our imaginations and leads us to new experimental windows on nature. Quantum interference phenomena are vividly displayed in the wide assembly of neutron interferometry experiments, which have been carried out since the first demonstration of a perfect silicon crystal interferometer in 1974. Since the neutron experiences all four fundamental forces of nature (strong, weak, electromagnetic, and gravitational), interferometry with neutrons provides a fertile testing ground for theory and precision measurements. Many Gedanken experiments of quantum mechanics have become real due to neutron interferometry. Quantum mechanics is a part of physics where experiment and theory are inseparably intertwined. This general theme permeates the second edition of this book. It discusses more than 40 neutron interferometry experiments along with their theoretical motivation...

  8. On the relation between seismic interferometry and the migration resolution function

    NARCIS (Netherlands)

    Thorbecke, J.W.; Wapenaar, C.P.A.

    2007-01-01

    Seismic interferometry refers to the process of retrieving new seismic responses by crosscorrelating seismic observations at different receiver locations. Seismic migration is the process of forming an image of the subsurface by wavefield extrapolation. Comparing the expressions for backward

  9. Accelerometer for Space Applications Based on Light-Pulse Atom Interferometry, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to build a compact, high-precision single-axis accelerometer based on atom interferometry that is applicable to operation in space environments. Based on...

  10. Accelerometer for Space Applications Based on Light-Pulse Atom Interferometry, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design a compact, high-precision, single-axis accelerometer based on atom interferometry that is applicable to operation in space environments. Our...

  11. Auroral and magnetic variations in the polar cusp and cleft. Signatures of magnetopause boundary layer dynamics

    International Nuclear Information System (INIS)

    Sandholt, P.E.; Egeland, A.

    1987-10-01

    By combining continous ground-based observations of polar cleft/cusp auroras and local magnetic variations with electromagnetic parameters obtained from satellites in polar orbit (low-altitude cleft/cusp) and in the magnetosheath/interplanetary space, different electrodynamic processes in the polar cleft/cusp have been investigated. One of the more controversial questions in this field is related to the observed shifts in latitude of cleft/cusp auroras and the relationships with the interplanetary magnetic field (IMF) orientation, local magnetic disturbances (DP2 and DPY modes) and magnetospheric substorms. A new approach which may contribute to clarifying these complicated relationships, simultaneous groundbased observations of the midday and evening-midnight sectors of the auroral oval, is illustrated. A related topic is the spatial relationship between the cleft/cusp auroras and the ionospheric convection currents. A characteristic feature of the polar cusp and cleft regions during negative IMF B z is repeated occurrence of certain short-lived auroral structures moving in accordance with the local convection pattern. Satellite measurements of particle precipitation, magnetic field and ion drift components permit detailed investigations of the electrodynamics of these cusp/cleft structures. Information on electric field components, Birkeland currents, Poynting flux, height-integrated Pedersen conductivity and Joule heat dissipation rate has been derived. These observations are discussed in relation to existing models of temporal plasma injections from the magnetosheath

  12. Analysis of reconstructed interference fields in digital holographic interferometry using the polynomial phase transform

    International Nuclear Information System (INIS)

    Gorthi, Sai Siva; Rastogi, Pramod

    2009-01-01

    A noisy wrapped phase map is the end-output of commonly employed phase estimation methods in digital holographic interferometry. Hence filtering and unwrapping are necessary to obtain continuous phase distributions. This paper introduces a new approach for phase estimation in digital holographic interferometry using the polynomial phase transform. The proposed approach directly provides an accurate estimation of the unwrapped phase distribution from a noisy reconstructed interference field, thereby bypassing cumbersome and error-prone filtering and 2D phase unwrapping procedures

  13. Potential of the McMath-Pierce 1.6-Meter Solar Telescope for Speckle Interferometry

    Science.gov (United States)

    Harshaw, Richard; Jones, Gregory; Wiley, Edward; Boyce, Patrick; Branston, Detrick; Rowe, David; Genet, Russell

    2015-09-01

    We explored the aiming and tracking accuracy of the McMath-Pierce 1.6 m solar telescope at Kitt Peak National Observatory as part of an investigation of using this telescope for speckle interferometry of close visual double stars. Several slews of various lengths looked for hysteresis in the positioning system (we found none of significance) and concluded that the 1.6 m telescope would make a useful telescope for speckle interferometry.

  14. Precise signal amplitude retrieval for a non-homogeneous diagnostic beam using complex interferometry approach

    Czech Academy of Sciences Publication Activity Database

    Krupka, M.; Kálal, M.; Dostál, Jan; Dudžák, Roman; Juha, Libor

    2017-01-01

    Roč. 12, Aug (2017), s. 1-6, č. článku C08012. ISSN 1748-0221 EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE Institutional support: RVO:68378271 Keywords : magnetic-field measurements * fully automated-analysis * laser-produced plasmas * image processing * interferometry * plasma diagnostics - interferometry * spectroscopy and imaging Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.220, year: 2016

  15. [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.

  16. Quantitative measurement of the vibrational amplitude and phase in photorefractive time-average interferometry: A comparison with electronic speckle pattern interferometry

    DEFF Research Database (Denmark)

    Rohleder, Henrik; Petersen, Paul Michael; Marrakchi, A.

    1994-01-01

    and amplitude of the vibrating structure are demonstrated in photorefractive time average interferometry. The photorefractive interferometer is compared with the performance of a commercial electronic speckle pattern interferometer (ESPI). It is shown that the dynamic photorefractive holographic interferometer......Time-average interferometry is dealt with using four-wave mixing in photorefractive Bi12SiO20. By introducing a proper sinusoidal phase shift in the forward pump beam it is possible to measure the amplitude and phase everywhere on a vibrating object. Quantitative measurements of the phase...

  17. 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.

  18. 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...

  19. 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.

  20. 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

  1. Assessing ScanSAR Interferometry for Deformation Studies

    Science.gov (United States)

    Buckley, S. M.; Gudipati, K.

    2007-12-01

    There is a trend in civil satellite SAR mission design to implement an imaging strategy that incorporates both stripmap mode and ScanSAR imaging. This represents a compromise between high resolution data collection and a desire for greater spatial coverage and more frequent revisit times. However, mixed mode imaging can greatly reduce the number of stripmap images available for measuring subtle ground deformation. Although ScanSAR-ScanSAR and ScanSAR-stripmap repeat-pass interferometry have been demonstrated, these approaches are infrequently used for single interferogram formation and nonexistent for InSAR time series analysis. For future mission design, e.g., a dedicated US InSAR mission, the effect of various ScanSAR system parameter choices on InSAR time series analysis also remains unexplored. Our objective is to determine the utility of ScanSAR differential interferometry. We will demonstrate the use of ScanSAR interferograms for several previous deformation studies: localized and broad-scale urban land subsidence, tunneling, volcanic surface movements and several examples associated with the seismic cycle. We also investigate the effect of various ScanSAR burst synchronization levels on our ability to detect and make quality measurements of deformation. To avoid the issues associated with Envisat ScanSAR burst alignment and to exploit a decade of InSAR measurements, we simulate ScanSAR data by bursting (throwing away range lines of) ERS-1/2 data. All the burst mode datasets are processed using a Modified SPECAN algorithm. To investigate the effects of burst misalignment, a number of cases with varying degrees of burst overlap are considered. In particular, we look at phase decorrelation as a function of percentage of burst overlap. Coherence clearly reduces as the percentage of overlap decreases and we find a useful threshold of 40-70% burst overlap depending on the study site. In order to get a more generalized understanding for different surface conditions

  2. Seeing Stars - Intensity Interferometry in the Laboratory & on the Ground

    Science.gov (United States)

    Carlile, Colin; Dravins, Dainis

    2018-04-01

    In many ways it is a golden age for astronomy. Spectacular new discoveries, for example the detection of gravitational waves, are very dependent upon instrumental development. The specific instrument development we propose, Intensity Interferometry (II), aims toimprove the spatial resolution of optical telescopes by 100x to 50µas [1]. This is impractical to achieve by increasing the size of telescopes or by extending the capabilities of phase interferometry. II, if implemented on the Cherenkov Telescope Array (CTA) currently being installed in La Palma and Paranal, would record the light intensity – the photon train - from many different telescopes, up to 2 km apart, on a nanosecond timescale and compare them. The signal from the many pairs of telescopes would quantify the degree of correlation by extracting the second-order correlation function, and thus create an image. This is not a real space image. However we can invert the data by Fourier Transform and create a real image. The more telescopes, the better resolved and more physical is the image, enabling the study of sunspots on nearby stars; orbiting binary stars; or exoplanets traversing the disc of their own star. We understand the Sun well but we have little experimental knowledge of how representative it is of main sequence stars. To test the II method, at Lund Observatory we have set up a laboratory analogue comprising ten small telescopes observing an artificial star created by light from a laser. The method has been shown to work [2] and the telescope array has now been extended to two dimensions. We are in discussion with other groups to explore the possibility of implementing this method on real telescopes observing actual stars. We plan to do this with the prototype Small Size Telescopes being built by groups in Europe, and ultimately with the CTA itself. A Science Working Group for II has now been set up within the CTA Consortium, of which Lund University is an integral part. A Letter of Intent

  3. Prosthetic clone and natural human tooth comparison by speckle interferometry

    Science.gov (United States)

    Slangen, Pierre; Corn, Stephane; Fages, Michel; Raynal, Jacques; Cuisinier, Frederic J. G.

    2010-09-01

    New trends in dental prosthodontic interventions tend to preserve the maximum of "body" structure. With the evolution of CAD-CAM techniques, it is now possible to measure "in mouth" the remaining dental tissues. The prosthetic crown is then designed using this shape on which it will be glued on, and also by taking into account the contact surface of the opposite jaw tooth. Several theories discuss on the glue thickness and formulation, but also on the way to evolve to a more biocompatible crown and also new biomechanical concepts. In order to validate these new concepts and materials, and to study the mechanical properties and mechanical integrity of the prosthesis, high resolution optical measurements of the deformations of the glue and the crown are needed. Samples are two intact premolars extracted for orthodontics reasons. The reference sample has no modifications on the tooth while the second sample tooth is shaped to receive a feldspathic ceramic monoblock crown which will be glued. This crown was manufactured with a chairside CAD-CAM system from an intra-oral optical print. The software allows to realize a nearly perfect clone of the reference sample. The necessary space for the glue is also entered with ideal values. This duplication process yields to obtain two samples with identical anatomy for further processing. The glue joint thickness can also be modified if required. The purpose is to compare the behaviour of a natural tooth and its prosthetic clone manufactured with "biomechanical" concepts. Vertical cut samples have been used to deal with planar object observation, and also to look "inside" the tooth. We have developed a complete apparatus enabling the study of the compressive mechanical behaviour of the concerned tooth by speckle interferometry. Because in plane displacements are of great interest for orthodontic measurements1, an optical fiber in-plane sensitive interferometer has been designed. The fibers are wrapped around piezoelectric

  4. Applications of atom interferometry - from ground to space

    Science.gov (United States)

    Schubert, Christian; Rasel, Ernst Maria; Gaaloul, Naceur; Ertmer, Wolfgang

    2016-07-01

    Atom interferometry is utilized for the measurement of rotations [1], accelerations [2] and for tests of fundamental physics [3]. In these devices, three laser light pulses separated by a free evolution time coherently manipulate the matter waves which resembles the Mach-Zehnder geometry in optics. Atom gravimeters demonstrated an accuracy of few microgal [2,4], and atom gradiometers showed a noise floor of 30 E Hz^{-1/2} [5]. Further enhancements of atom interferometers are anticipated by the integration of novel source concepts providing ultracold atoms, extending the free fall time of the atoms, and enhanced techniques for coherent manipulation. Sources providing Bose-Einstein condensates recently demontrated a flux compatible with precision experiments [6]. All of these aspects are studied in the transportable quantum gravimeter QG-1 and the very long baseline atom interferometry teststand in Hannover [7] with the goal of surpassing the microgal regime. Going beyond ground based setups, the QUANTUS collaboration exploits the unique features of a microgravity environment in drop tower experiments [8] and in a sounding rocket mission. The payloads are compact and robust atom optics experiments based on atom chips [6], enabling technology for transportable sensors on ground as a byproduct. More prominently, they are pathfinders for proposed satellite missions as tests of the universality of free fall [9] and gradiometry based on atom interferometers [10]. This work is supported by the German Space Agency (DLR) with funds provided by the Federal Ministry for Economic Affairs and Energy (BMWi) due to an enactment of the German Bundestag under grant numbers DLR 50WM1552-1557 (QUANTUS-IV-Fallturm) and by the Deutsche Forschungsgemeinschaft in the framework of the SFB 1128 geo-Q. [1] PRL 114 063002 2015 [2] Nature 400 849 1999 [3] PRL 112 203002 2014 [4] NJP 13 065026 2011 [5] PRA 65 033608 2002 [6] NJP 17 065001 2015 [7] NJP 17 035011 2015 [8] PRL 110 093602 2013 [9

  5. Laser Micromachining and Information Discovery Using a Dual Beam Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Theppakuttaikomaraswamy, Senthil P. [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    Lasers have proven to be among the most promising tools for micromachining because they can process features down to the size of the laser wavelength (smaller than 1 micrometer) and they provide a non-contact technology for machining. The demand for incorporating in-situ diagnostics technology into the micromachining environment is driven by the increasing need for producing micro-parts of high quality and accuracy. Laser interferometry can be used as an on-line monitoring tool and it is the aim of this work to enhance the understanding and application of Michelson interferometry principle for the in-situ diagnostics of the machining depth on the sub-micron and micron scales. micromachining is done on two different materials and a comprehensive investigation is done to control the width and depth of the machined feature. To control the width of the feature, laser micromachining is done on copper and a detailed analysis is performed. The objective of this experiment is to make a precision mask for sputtering with an array of holes on it using an Nd:YAG laser of 532 nm wavelength. The diameter of the hole is 50 μm and the spacing between holes (the distance between the centers) is 100 μm. Michelson interferometer is integrated with a laser machining system to control the depth of machining. An excimer laser of 308 nm wavelength is used for micromachining. A He-Ne laser of 632.8 nm wavelength is used as the light source for the interferometer. Interference patterns are created due to the change in the path length between the two interferometer arms. The machined depth information is obtained from the interference patterns on an oscilloscope detected by a photodiode. To compare the predicted depth by the interferometer with the true machining depth, a surface profilometer is used to measure the actual machining depth on the silicon. It is observed that the depths of machining obtained by the surface profile measurement are in accordance with the interferometer

  6. Quantitative determination of testosterone levels with biolayer interferometry.

    Science.gov (United States)

    Zhang, Hao; Li, Wei; Luo, Hong; Xiong, Guangming; Yu, Yuanhua

    2017-10-01

    Natural and synthetic steroid hormones are widely spread in the environment and are considered as pollutants due to their endocrine activities, even at low concentrations, which are harmful to human health. To detect steroid hormones in the environment, a novel biosensor system was developed based on the principle of biolayer interferometry. Detection is based on changes in the interference pattern of white light reflected from the surface of an optical fiber with bound biomolecules. Monitoring interactions between molecules does not require radioactive, enzymatic, or fluorescent labels. Here, 2 double-stranded DNA fragments of operator 1 (OP1) and OP2 containing 10-bp palindromic sequences in chromosomal Comamonas testosteroni DNA (ATCC11996) were surface-immobilized to streptavidin sensors. Interference changes were detected when repressor protein RepA bound the DNA sequences. DNA-protein interactions were characterized and kinetic parameters were obtained. The dissociation constants between the OP1 and OP2 DNA sequences and RepA were 9.865 × 10 -9  M and 2.750 × 10 -8  M, respectively. The reactions showed high specifically and affinity. Because binding of the 10-bp palindromic sequence and RepA was affected by RepA-testosterone binding, the steroid could be quantitatively determined rapidly using the biosensor system. The mechanism of the binding assay was as follows. RepA could bind both OP1 and testosterone. RepA binding to testosterone changed the protein conformation, which influenced the binding between RepA and OP1. The percentage of the signal detected negative correlation with the testosterone concentration. A standard curve was obtained, and the correlation coefficient value was approximately 0.97. We could quantitatively determine testosterone levels between 2.13 and 136.63 ng/ml. Each sample could be quantitatively detected in 17 min. These results suggested that the specific interaction between double-stranded OP1 DNA and the RepA protein

  7. 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

  8. 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

  9. 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…

  10. 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:

  11. 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

  12. 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…

  13. Light-free magnetic resonance force microscopy for studies of electron spin polarized systems

    International Nuclear Information System (INIS)

    Pelekhov, Denis V.; Selcu, Camelia; Banerjee, Palash; Chung Fong, Kin; Chris Hammel, P.; Bhaskaran, Harish; Schwab, Keith

    2005-01-01

    Magnetic resonance force microscopy is a scanned probe technique capable of three-dimensional magnetic resonance imaging. Its excellent sensitivity opens the possibility for magnetic resonance studies of spin accumulation resulting from the injection of spin polarized currents into a para-magnetic collector. The method is based on mechanical detection of magnetic resonance which requires low noise detection of cantilever displacement; so far, this has been accomplished using optical interferometry. This is undesirable for experiments on doped silicon, where the presence of light is known to enhance spin relaxation rates. We report a non-optical displacement detection scheme based on sensitive microwave capacitive readout

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Compensation of sampling error in frequency scanning interferometry

    Science.gov (United States)

    Shang, Yue; Lin, Jiarui; Yang, Linghui; Ren, Yongjie

    2018-01-01

    Absolute distance measurement techniques are of significant interest in the field of large volume metrology. Ones which could offer an ability of ADM and high accuracy will improve the efficiency and the quality of large assemblies. Frequency scanning interferometry (FSI) is a kind of ADM technique which use a variable synthetic-wavelength achieved by tuning the optical frequency continuously. FSI could offer a relative accuracy of several ppm in a range of tens of meters. In a FSI ranging system, it is necessary to get knowledge of the tuning range of optical frequency, which could be done by using of gas absorption cell, femtosecond laser comb, F-P etalon and the most used: a predicted auxiliary interferometer. As the result of the measurement is calculated by the tuning range of optical frequency, a length drift of the auxiliary interferometer will make a contribution in error of the result. Analysis of sampling error caused by the drift of the auxiliary interferometer has been done and a real-time compensation system has been proposed to minimize the drift of the auxiliary interferometer. The simulation has proved the analysis and the error has been decreased.

  19. Multiwavelength interferometry system for the Orion laser facility.

    Science.gov (United States)

    Patankar, S; Gumbrell, E T; Robinson, T S; Lowe, H F; Giltrap, S; Price, C J; Stuart, N H; Kemshall, P; Fyrth, J; Luis, J; Skidmore, J W; Smith, R A

    2015-12-20

    We report on the design and testing of a multiwavelength interferometry system for the Orion laser facility based upon the use of self-path matching Wollaston prisms. The use of UV corrected achromatic optics allows for both easy alignment with an eye-safe light source and small (∼ millimeter) offsets to the focal lengths between different operational wavelengths. Interferograms are demonstrated at wavelengths corresponding to first, second, and fourth harmonics of a 1054 nm Nd:glass probe beam. Example data confirms the broadband achromatic capability of the imaging system with operation from the UV (263 nm) to visible (527 nm) and demonstrates that features as small as 5 μm can be resolved for object sizes of 15 by 10 mm. Results are also shown for an off-harmonic wavelength that will underpin a future capability. The primary optics package is accommodated inside the footprint of a ten-inch manipulator to allow the system to be deployed from a multitude of viewing angles inside the 4 m diameter Orion target chamber.

  20. Probing infrared detectors through energy-absorption interferometry

    Science.gov (United States)

    Moinard, Dan; Withington, Stafford; Thomas, Christopher N.

    2017-08-01

    We describe an interferometric technique capable of fully characterizing the optical response of few-mode and multi-mode detectors using only power measurements, and its implementation at 1550 nm wavelength. EnergyAbsorption Interferometry (EAI) is an experimental procedure where the system under test is excited with two coherent, phase-locked sources. As the relative phase between the sources is varied, a fringe is observed in the detector output. Iterating over source positions, the fringes' complex visibilities allow the two-point detector response function to be retrieved: this correlation function corresponds to the state of coherence to which the detector is maximally sensitive. This detector response function can then be decomposed into a set of natural modes, in which the detector is incoherently sensitive to power. EAI therefore allows the reconstruction of the individual degrees of freedom through which the detector can absorb energy, including their relative sensitivities and full spatial forms. Coupling mechanisms into absorbing structures and their underlying solidstate phenomena can thus be studied, with direct applications in improving current infrared detector technology. EAI has previously been demonstrated for millimeter wavelength. Here, we outline the theoretical basis of EAI, and present a room-temperature 1550 nm wavelength infrared experiment we have constructed. Finally, we discuss how this experimental system will allow us to study optical coupling into fiber-based systems and near-infrared detectors.

  1. Atmospheric pressure loading parameters from very long baseline interferometry observations

    Science.gov (United States)

    Macmillan, D. S.; Gipson, John M.

    1994-01-01

    Atmospheric mass loading produces a primarily vertical displacement of the Earth's crust. This displacement is correlated with surface pressure and is large enough to be detected by very long baseline interferometry (VLBI) measurements. Using the measured surface pressure at VLBI stations, we have estimated the atmospheric loading term for each station location directly from VLBI data acquired from 1979 to 1992. Our estimates of the vertical sensitivity to change in pressure range from 0 to -0.6 mm/mbar depending on the station. These estimates agree with inverted barometer model calculations (Manabe et al., 1991; vanDam and Herring, 1994) of the vertical displacement sensitivity computed by convolving actual pressure distributions with loading Green's functions. The pressure sensitivity tends to be smaller for stations near the coast, which is consistent with the inverted barometer hypothesis. Applying this estimated pressure loading correction in standard VLBI geodetic analysis improves the repeatability of estimated lengths of 25 out of 37 baselines that were measured at least 50 times. In a root-sum-square (rss) sense, the improvement generally increases with baseline length at a rate of about 0.3 to 0.6 ppb depending on whether the baseline stations are close to the coast. For the 5998-km baseline from Westford, Massachusetts, to Wettzell, Germany, the rss improvement is about 3.6 mm out of 11.0 mm. The average rss reduction of the vertical scatter for inland stations ranges from 2.7 to 5.4 mm.

  2. Coherent-light-boosted, sub-shot noise, quantum interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Plick, William N; Dowling, Jonathan P [Hearne Institute for Theoretical Physics, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Agarwal, Girish S, E-mail: bplick@yahoo.co [Department of Physics, Oklahoma State University, Stillwater, OK 74078 (United States)

    2010-08-15

    We present in this paper a new scheme for optical interferometry. We utilize coherent-beam-stimulated two-mode squeezed light, which interacts with a phase shifter and is then squeezed again before detection. Our theoretical device has the potential to reach far below the shot-noise limit in phase sensitivity. This new proposal avoids the pitfalls of other setups, such as difficulty in creating the required resource. Furthermore, our scheme requires no complicated detection protocol, relying instead only on simple intensity measurement. Also, bright, coherent sources 'boost' squeezed light, creating a very sensitive device. This hybrid scheme relies on no unknown components and can be constructed with current technology. In this paper, we present our analysis of this relatively straightforward device, using the operator propagation method. We derive the phase sensitivity and provide a simple numerical example of the power of our new proposal. Sensitivity to unknown phase shifts scales as a shot-noise-limited Mach-Zehnder interferometer, multiplied by a sub-Heisenberg contribution from the squeezed light.

  3. Coherent-light-boosted, sub-shot noise, quantum interferometry

    International Nuclear Information System (INIS)

    Plick, William N; Dowling, Jonathan P; Agarwal, Girish S

    2010-01-01

    We present in this paper a new scheme for optical interferometry. We utilize coherent-beam-stimulated two-mode squeezed light, which interacts with a phase shifter and is then squeezed again before detection. Our theoretical device has the potential to reach far below the shot-noise limit in phase sensitivity. This new proposal avoids the pitfalls of other setups, such as difficulty in creating the required resource. Furthermore, our scheme requires no complicated detection protocol, relying instead only on simple intensity measurement. Also, bright, coherent sources 'boost' squeezed light, creating a very sensitive device. This hybrid scheme relies on no unknown components and can be constructed with current technology. In this paper, we present our analysis of this relatively straightforward device, using the operator propagation method. We derive the phase sensitivity and provide a simple numerical example of the power of our new proposal. Sensitivity to unknown phase shifts scales as a shot-noise-limited Mach-Zehnder interferometer, multiplied by a sub-Heisenberg contribution from the squeezed light.

  4. High Precision Signal Processing Algorithm for White Light Interferometry

    Directory of Open Access Journals (Sweden)

    Jeonggon Harrison Kim

    2008-12-01

    Full Text Available A new signal processing algorithm for absolute temperature measurement using white light interferometry has been proposed and investigated theoretically. The proposed algorithm determines the phase delay of an interferometer with very high precision (<< one fringe by identifying the zero order fringe peak of cross-correlation of two fringe scans of white light interferometer. The algorithm features cross-correlation of interferometer fringe scans, hypothesis testing and fine tuning. The hypothesis test looks for a zero order fringe peak candidate about which the cross-correlation is symmetric minimizing the uncertainty of mis-identification. Fine tuning provides the proposed algorithm with high precision subsample resolution phase delay estimation capability. The shot noise limited performance of the proposed algorithm has been analyzed using computer simulations. Root-mean-square (RMS phase error of the estimated zero order fringe peak has been calculated for the changes of three different parameters (SNR, fringe scan sample rate, coherence length of light source. Computer simulations showed that the proposed signal processing algorithm identified the zero order fringe peak with a miss rate of 3 x 10-4 at 31 dB SNR and the extrapolated miss rate at 35 dB was 3 x 10-8. Also, at 35 dB SNR, RMS phase error less than 10-3 fringe was obtained. The proposed signal processing algorithm uses a software approach that is potentially inexpensive, simple and fast.

  5. Atom interferometry in space: Thermal management and magnetic shielding

    Energy Technology Data Exchange (ETDEWEB)

    Milke, Alexander; Kubelka-Lange, André; Gürlebeck, Norman, E-mail: norman.guerlebeck@zarm.uni-bremen.de; Rievers, Benny; Herrmann, Sven [Center of Applied Space Technology and Microgravity (ZARM), University Bremen, Am Fallturm, 28359 Bremen (Germany); Schuldt, Thilo [DLR Institute for Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany); Braxmaier, Claus [Center of Applied Space Technology and Microgravity (ZARM), University Bremen, Am Fallturm, 28359 Bremen (Germany); DLR Institute for Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany)

    2014-08-15

    Atom interferometry is an exciting tool to probe fundamental physics. It is considered especially apt to test the universality of free fall by using two different sorts of atoms. The increasing sensitivity required for this kind of experiment sets severe requirements on its environments, instrument control, and systematic effects. This can partially be mitigated by going to space as was proposed, for example, in the Spacetime Explorer and Quantum Equivalence Principle Space Test (STE-QUEST) mission. However, the requirements on the instrument are still very challenging. For example, the specifications of the STE-QUEST mission imply that the Feshbach coils of the atom interferometer are allowed to change their radius only by about 260 nm or 2.6 × 10{sup −4} % due to thermal expansion although they consume an average power of 22 W. Also Earth's magnetic field has to be suppressed by a factor of 10{sup 5}. We show in this article that with the right design such thermal and magnetic requirements can indeed be met and that these are not an impediment for the exciting physics possible with atom interferometers in space.

  6. All-Sky Interferometry with Spherical Harmonic Transit Telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, J.Richard [Canadian Inst. Theor. Astrophys.; Sigurdson, Kris [British Columbia U.; Pen, Ue-Li [Canadian Inst. Theor. Astrophys.; Stebbins, Albert [Fermilab; Sitwell, Michael [British Columbia U.

    2013-02-01

    In this paper we describe the spherical harmonic transit telescope, a novel formalism for the analysis of transit radio telescopes. This all-sky approach bypasses the curved sky complications of traditional interferometry and so is particularly well suited to the analysis of wide-field radio interferometers. It enables compact and computationally efficient representations of the data and its statistics that allow new ways of approaching important problems like map-making and foreground removal. In particular, we show how it enables the use of the Karhunen-Loeve transform as a highly effective foreground filter, suppressing realistic foreground residuals for our fiducial example by at least a factor twenty below the 21cm signal even in highly contaminated regions of the sky. This is despite the presence of the angle-frequency mode mixing inherent in real-world instruments with frequency-dependent beams. We show, using Fisher forecasting, that foreground cleaning has little effect on power spectrum constraints compared to hypothetical foreground-free measurements. Beyond providing a natural real-world data analysis framework for 21cm telescopes now under construction and future experiments, this formalism allows accurate power spectrum forecasts to be made that include the interplay of design constraints and realistic experimental systematics with twenty-first century 21cm science.

  7. Spaceborne Polarimetric SAR Interferometry: Performance Analysis and Mission Concepts

    Directory of Open Access Journals (Sweden)

    Shane R. Cloude

    2005-12-01

    Full Text Available We investigate multichannel imaging radar systems employing coherent combinations of polarimetry and interferometry (Pol-InSAR. Such systems are well suited for the extraction of bio- and geophysical parameters by evaluating the combined scattering from surfaces and volumes. This combination leads to several important differences between the design of Pol-InSAR sensors and conventional single polarisation SAR interferometers. We first highlight these differences and then investigate the Pol-InSAR performance of two proposed spaceborne SAR systems (ALOS/PalSAR and TerraSAR-L operating in repeat-pass mode. For this, we introduce the novel concept of a phase tube which enables (1 a quantitative assessment of the Pol-InSAR performance, (2 a comparison between different sensor configurations, and (3 an optimization of the instrument settings for different Pol-InSAR applications. The phase tube may hence serve as an interface between system engineers and application-oriented scientists. The performance analysis reveals major limitations for even moderate levels of temporal decorrelation. Such deteriorations may be avoided in single-pass sensor configurations and we demonstrate the potential benefits from the use of future bi- and multistatic SAR interferometers.

  8. Using Clocks and Atomic Interferometry for Gravity Field Observations

    Science.gov (United States)

    Müller, Jürgen

    2016-07-01

    New technology developed in the frame of fundamental physics may lead to enhanced capabilities for geodetic applications such as refined observations of the Earth's gravity field. Here, we will present new sensor measurement concepts that apply atomic interferometry for gravimetry and clock measurements for observing potential values. In the first case, gravity anomalies can be determined by observing free-falling atoms (quantum gravimetry). In the second case, highly precise optical clocks can be used to measure differences of the gravity potential over long distances (relativistic geodesy). Principally, also inter-satellite ranging between test masses in space with nanometer accuracy belongs to these novel developments. We will show, how the new measurement concepts are connected to classical geodetic concepts, e.g. geopotential numbers and clock readings. We will illustrate the application of these new methods and their benefit for geodesy, where local and global mass variations can be observed with unforeseen accuracy and resolution, mass variations that reflect processes in the Earth system. We will present a few examples where geodesy will potentially benefit from these developments. Thus, the novel technologies might be applied for defining and realizing height systems in a new way, but also for fast local gravimetric surveys and exploration.

  9. X-ray laser interferometry: A new tool for AGEX

    International Nuclear Information System (INIS)

    Wan, A.S.; Moreno, J.C.; Libby, S.B.

    1995-10-01

    Collisionally pumped soft x-ray lasers now operate over a wavelength range extending from 4--40 nm. With the recent advances in the development of multilayer mirrors and beamsplitters in the soft x-ray regime, we can utilize the unique properties of x-ray lasers to study large, rapidly evolving laser-driven plasmas with high electron densities. By employing a shorter wavelength x-ray laser, as compared to using conventional optical laser as the probe source, we can access a much higher density regime while reducing refractive effects which limit the spatial resolution and data interpretation. Using a neon-like yttrium x-ray laser which operates at a wavelength of 15.5 mn, we have performed a series of soft x-ray laser interferometry experiments, operated in the skewed Mach-Zehnder configuration, to characterize plasmas relevant to both weapons and inertial confinement fusion. The two-dimensional density profiles obtained from the interferograms allow us to validate and benchmark our numerical models used to study the physics in the high-energy density regime, relevant to both weapons and inertial confinement fusion

  10. Investigating ground instabilities in Indonesia through SAR interferometry

    Science.gov (United States)

    Bovenga, Fabio; Refice, Alberto; Belmonte, Antonella; Nutricato, Raffaele; Nitti, Davide Oscar; Chiaradia, Maria Teresa; Valkaniotis, Sotirios; Gkioni, Sofia; Kosma, Chrysanthi; Ganas, Athanassis; Manunta, Paolo; Elizar; Darusman; Bally, Philippe

    2017-10-01

    Indonesia is periodically affected by severe volcanic eruptions and earthquakes, which are geologically coupled to the convergence of the Australian tectonic plate beneath the Sunda Plate. Multi-temporal SAR interferometry (MTI) can be used to support studying and modelling of terrain movements. This work is aimed at performing an analysis of ground displacements over Indonesian sites through MTI techniques. Test sites have been selected according to the availability of archived SAR data, GNSS networks, and geological data. A stack of COSMO-SkyMed data, acquired in stripmap mode between 2011 and 2015, has been selected over the Banda Aceh region in Sumatra island. Geological maps of the test sites are available, and several GNSS stations from the Continuously Operating Reference Stations Indonesian network are found in the area of interest. Both the SPINUA and the StaMPS MTI algorithms have been used for processing the data, and deriving displacement maps. The ground deformations detected on the area are interpreted according to the available geological and geophysical information. The MTI results seem to confirm the inactivity of the Aceh fault segment, while the lack of coherent targets hinders reliable displacement measurements along the Seulineum segment. MTI data additionally allowed to identify local, non-tectonic ground instabilities: several areas are affected by subsidence due to unconsolidated coastal and alluvial sediments, deserving more investigations by local authorities. Finally, MTI results could be useful to integrate and update data from the existing GPS network.

  11. Distortion of two-pion interferometry by multipion correlations

    International Nuclear Information System (INIS)

    Zhang, W.N.; Liu, Y.M.; Wang, S.; Liu, Q.J.; Jiang, J.; Keane, D.; Shao, Y.; Chu, S.Y.; Fung, S.Y.

    1993-01-01

    Multipion correlations arising from the symmetrization of the n-pion wave function affect the extracted information from two-pion correlation measurements. The influence of multipion correlations on a sample of like-pion pairs can be expressed as a multipion correlation factor, the distribution of which offers good sensitivity to the multipion correlation effect. Analyses of the multipion correlation factor for two Bevalac streamer chamber data samples of 2.1A GeV Ne+Pb and 1.8A GeV Ar+Pb collisions show that the multipion correlation effect in the former sample is greater than in the latter. This result mainly arises from the fact that the pion source for Ne projectiles is smaller than for Ar projectiles. The residual correlations in the reference sample are related to the multipion correlation factor in multipion events, which can be expressed as a residual correlation factor. The influence of multipion correlations on two-pion interferometry analyses arises from the ratio of the residual correlation factor to the multipion correlation factor

  12. Spaceborne Polarimetric SAR Interferometry: Performance Analysis and Mission Concepts

    Science.gov (United States)

    Krieger, Gerhard; Papathanassiou, Konstantinos Panagiotis; Cloude, Shane R.

    2005-12-01

    We investigate multichannel imaging radar systems employing coherent combinations of polarimetry and interferometry (Pol-InSAR). Such systems are well suited for the extraction of bio- and geophysical parameters by evaluating the combined scattering from surfaces and volumes. This combination leads to several important differences between the design of Pol-InSAR sensors and conventional single polarisation SAR interferometers. We first highlight these differences and then investigate the Pol-InSAR performance of two proposed spaceborne SAR systems (ALOS/PalSAR and TerraSAR-L) operating in repeat-pass mode. For this, we introduce the novel concept of a phase tube which enables (1) a quantitative assessment of the Pol-InSAR performance, (2) a comparison between different sensor configurations, and (3) an optimization of the instrument settings for different Pol-InSAR applications. The phase tube may hence serve as an interface between system engineers and application-oriented scientists. The performance analysis reveals major limitations for even moderate levels of temporal decorrelation. Such deteriorations may be avoided in single-pass sensor configurations and we demonstrate the potential benefits from the use of future bi- and multistatic SAR interferometers.

  13. Mesospheric gravity wave momentum flux estimation using hybrid Doppler interferometry

    Directory of Open Access Journals (Sweden)

    A. J. Spargo

    2017-06-01

    Full Text Available Mesospheric gravity wave (GW momentum flux estimates using data from multibeam Buckland Park MF radar (34.6° S, 138.5° E experiments (conducted from July 1997 to June 1998 are presented. On transmission, five Doppler beams were symmetrically steered about the zenith (one zenith beam and four off-zenith beams in the cardinal directions. The received beams were analysed with hybrid Doppler interferometry (HDI (Holdsworth and Reid, 1998, principally to determine the radial velocities of the effective scattering centres illuminated by the radar. The methodology of Thorsen et al. (1997, later re-introduced by Hocking (2005 and since extensively applied to meteor radar returns, was used to estimate components of Reynolds stress due to propagating GWs and/or turbulence in the radar resolution volume. Physically reasonable momentum flux estimates are derived from the Reynolds stress components, which are also verified using a simple radar model incorporating GW-induced wind perturbations. On the basis of these results, we recommend the intercomparison of momentum flux estimates between co-located meteor radars and vertical-beam interferometric MF radars. It is envisaged that such intercomparisons will assist with the clarification of recent concerns (e.g. Vincent et al., 2010 of the accuracy of the meteor radar technique.

  14. Amplitude and phase characterization by diffracted beam interferometry: blind dbi

    International Nuclear Information System (INIS)

    Lopez Lago, E; Gonzalez Nunez, H; De la Fuente, R

    2011-01-01

    Diffracted beam interferometry is a self referenced method characterization technique whose operation principle is based on the reconstruction of the phase of a beam starting from the interference data between the beam and its diffracted copy. The phase is recovered indirectly by means of an iterative algorithm that relates the irradiances of the interfering beams and its phase difference. The first experimental demonstration of DBI was implemented on a Mach-Zehnder interferometer which incorporated an afocal imaging system in each arm, in order to form an image of a common object in different planes at the output of the interferometer. The irradiance data as well as the phase difference data were picked up from one of the image planes and they were introduced in the iterative algorithm. In this work we discuss a modification of the algorithm that allows to reconstruct simultaneously the amplitude and phase of the wavefront starting from, exclusively, the phase difference between the two waves that interfere in one of the image planes. This new algorithm improves the reconstruction process because the data acquisition process is faster and consequently the method is less influenced by environment disturbances. The method has been applied successfully to the characterization of phase plates and laser beams as well as to the local characterization of ophthalmic lenses.

  15. Research on long-range grating interferometry with nanometer resolution

    International Nuclear Information System (INIS)

    Chu, Xingchun; Zhao, Shanghong; Lü, Haibao

    2008-01-01

    Grating interferometry that features long range and nanometer resolution is presented. The optical system was established based on a single long metrology grating. The large fringe multiplication was achieved by properly selecting two high-order diffraction beams to form a fringe pattern. The fringe pattern collected by a linear array was first tailored to a few multiples of fringes in order to suppress the effect of the energy leakage on phase-extracting precision when the fast Fourier transform (FFT) algorithm was used to calculate its phase. Thus, the phase-extracting precision of a tailored fringe pattern by FFT was greatly improved. Based on this, a novel subdividing method, which exploited the time-shift property of FFT, was developed to subdivide the fringe with large multiple and high accuracy. Numerical results show that the system resolution reaches 1 nm. The experimental results obtained against a capacitive sensor in the sub-mm range show that the measurement precision of the system is less than 10 nm. (technical design note)

  16. Distributed gas sensing with optical fibre photothermal interferometry.

    Science.gov (United States)

    Lin, Yuechuan; Liu, Fei; He, Xiangge; Jin, Wei; Zhang, Min; Yang, Fan; Ho, Hoi Lut; Tan, Yanzhen; Gu, Lijuan

    2017-12-11

    We report the first distributed optical fibre trace-gas detection system based on photothermal interferometry (PTI) in a hollow-core photonic bandgap fibre (HC-PBF). Absorption of a modulated pump propagating in the gas-filled HC-PBF generates distributed phase modulation along the fibre, which is detected by a dual-pulse heterodyne phase-sensitive optical time-domain reflectometry (OTDR) system. Quasi-distributed sensing experiment with two 28-meter-long HC-PBF sensing sections connected by single-mode transmission fibres demonstrated a limit of detection (LOD) of ∼10 ppb acetylene with a pump power level of 55 mW and an effective noise bandwidth (ENBW) of 0.01 Hz, corresponding to a normalized detection limit of 5.5ppb⋅W/Hz. Distributed sensing experiment over a 200-meter-long sensing cable made of serially connected HC-PBFs demonstrated a LOD of ∼ 5 ppm with 62.5 mW peak pump power and 11.8 Hz ENBW, or a normalized detection limit of 312ppb⋅W/Hz. The spatial resolution of the current distributed detection system is limited to ∼ 30 m, but it is possible to reduce down to 1 meter or smaller by optimizing the phase detection system.

  17. Disentangling stellar activity from exoplanetary signals with interferometry

    Directory of Open Access Journals (Sweden)

    Ligi Roxanne

    2015-01-01

    Full Text Available Stellar activity can express as many forms at stellar surfaces: dark spots, convective cells, bright plages. Particularly, dark spots and bright plages add noise on photometric data or radial velocity measurements used to detect exoplanets, and thus lead to false detection or disrupt their derived parameters. Since interferometry provides a very high angular resolution, it may constitute an interesting solution to distinguish the signal of a transiting exoplanet and that of stellar activity. It has also been shown that granulation adds bias in visibility and closure phase measurements, affecting in turn the derived stellar parameters. We analyze the noises generated by dark spots on interferometric observables and compare them to exoplanet signals. We investigate the current interferometric instruments able to measure and disentangle these signals, and show that there is a lack in spatial resolution. We thus give a prospective of the improvements to be brought on future interferometers, which would also significantly extend the number of available targets.

  18. Precision displacement interferometry with stabilization of wavelength on air

    Directory of Open Access Journals (Sweden)

    Buchta Z.

    2013-05-01

    Full Text Available We present an interferometric technique based on differential interferometry setup for measurement in the subnanometer scale in atmospheric conditions. The motivation for development of this ultraprecise technique is coming from the field of nanometrology. The key limiting factor in any optical measurement are fluctuations of the refractive index of air representing a source of uncertainty on the 10-6level when evaluated indirectly from the physical parameters of the atmosphere. Our proposal is based on the concept of overdetermined interferometric setup where a reference length is derived from a mechanical frame made from a material with very low thermal coefficient on the 10-8level. The technique allows to track the variations of the refractive index of air on-line directly in the line of the measuring beam and to compensate for the fluctuations. The optical setup consists of three interferometers sharing the same beam path where two measure differentially the displacement while the third represents a reference for stabilization of the wavelength of the laser source. The principle is demonstrated on an experimental setup and a set of measurements describing the performance is presented.

  19. Iterative interferometry-based method for picking microseismic events

    Science.gov (United States)

    Iqbal, Naveed; Al-Shuhail, Abdullatif A.; Kaka, SanLinn I.; Liu, Entao; Raj, Anupama Govinda; McClellan, James H.

    2017-05-01

    Continuous microseismic monitoring of hydraulic fracturing is commonly used in many engineering, environmental, mining, and petroleum applications. Microseismic signals recorded at the surface, suffer from excessive noise that complicates first-break picking and subsequent data processing and analysis. This study presents a new first-break picking algorithm that employs concepts from seismic interferometry and time-frequency (TF) analysis. The algorithm first uses a TF plot to manually pick a reference first-break and then iterates the steps of cross-correlation, alignment, and stacking to enhance the signal-to-noise ratio of the relative first breaks. The reference first-break is subsequently used to calculate final first breaks from the relative ones. Testing on synthetic and real data sets at high levels of additive noise shows that the algorithm enhances the first-break picking considerably. Furthermore, results show that only two iterations are needed to converge to the true first breaks. Indeed, iterating more can have detrimental effects on the algorithm due to increasing correlation of random noise.

  20. Enhancing core-diffracted arrivals by supervirtual interferometry

    KAUST Repository

    Bharadwaj, P.

    2013-12-03

    A supervirtual interferometry (SVI) method is presented that can enhance the signal-to-noise ratio (SNR) of core diffracted waveforms by as much as O( √ N), where N is the number of inline receivers that record the core-mantle boundary (CMB) diffractions from more than one event. Here, the events are chosen to be approximately inline with the receivers along the same great circle. Results with synthetic and teleseismic data recorded by USArray stations demonstrate that formerly unusable records with low SNR can be transformed to high SNR records with clearly visible CMB diffractions. Another benefit is that SVI allows for the recording of a virtual earthquake at stations not deployed during the time of the earthquake. This means that portable arrays such as USArray can extend the aperture of one recorded earthquake from the West coast to the East coast, even though the teleseism might have only been recorded during theWest coast deployment. In summary, SVI applied to teleseismic data can significantly enlarge the catalogue of usable records both in SNR and available aperture for analysing CMB diffractions. A potential drawback of this method is that it generally provides the correct kinematics of CMB diffractions, but does not necessarily preserve correct amplitude information. © The Authors 2013. Published by Oxford University Press on behalf of The Royal Astronomical Society.

  1. Gravity sensing using Very Long Baseline Atom Interferometry

    Science.gov (United States)

    Schlippert, D.; Wodey, E.; Meiners, C.; Tell, D.; Schubert, C.; Ertmer, W.; Rasel, E. M.

    2017-12-01

    Very Long Baseline Atom Interferometry (VLBAI) has applications in high-accuracy absolute gravimetry, gravity-gradiometry, and for tests of fundamental physics. Thanks to the quadratic scaling of the phase shift with increasing free evolution time, extending the baseline of atomic gravimeters from tens of centimeters to meters puts resolutions of 10-13g and beyond in reach.We present the design and progress of key elements of the VLBAI-test stand: a dual-species source of Rb and Yb, a high-performance two-layer magnetic shield, and an active vibration isolation system allowing for unprecedented stability of the mirror acting as an inertial reference. We envisage a vibration-limited short-term sensitivity to gravitational acceleration of 1x10-8 m/s-2Hz-1/2 and up to a factor of 25 improvement when including additional correlation with a broadband seismometer. Here, the supreme long-term stability of atomic gravity sensors opens the route towards competition with superconducting gravimeters. The operation of VLBAI as a differential dual-species gravimeter using ultracold mixtures of Yb and Rb atoms enables quantum tests of the universality of free fall (UFF) at an unprecedented level of <10-13, potentially surpassing the best experiments to date.

  2. Quantum Description of Optical Devices Used in Interferometry

    Directory of Open Access Journals (Sweden)

    P. Kucera

    2007-09-01

    Full Text Available A quantum-mechanical description of the phase shifters, retarders, mirrors and beam splitters is given in the paper. The description is then applied on two types of states. On a coherent state, a classical-like state, and on a number state, hence the strict quantum state. The quantum description of a beam splitter can be found in the literature. However the description does not treat with the polarization concept. The paper is aimed to introduce quantum description of an arbitrary oriented retarder and give a description of a beam splitter which treats with the polarization.

  3. 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.

  4. Reconstruction of surface waves using super virtual interferometry: an example from the Forsmark site, Sweden

    Science.gov (United States)

    Xu, Zhuo; Juhlin, Christopher; Han, Liguo; Zhang, Fengjiao

    2017-10-01

    Seismic interferometry is a technique that enables the extraction of the seismic impulse response (Green's function) between two receivers. The retrieved response is generally dominated by surface waves when sources are located at or near the surface of the Earth. In onshore seismic exploration, dealing with complex near-surface conditions is one of the main challenges for seismic data processing. In some cases, seismic interferometry can be used for suppressing surface waves without the use of a priori near-surface velocity model. Aside from being an effective tool for surface wave attenuation, the reconstructed surface waves generated by seismic interferometry contain useful information about near-surface heterogeneities and can be used to characterize the near-surface velocity field. In this study, we apply super virtual interferometry (SVI) to a real onshore data set from the Forsmark site, central Sweden, with the primary aim of characterizing shallow-subsurface structure. This is accomplished by improving the dispersion characteristics of the surface waves. We also show that SVI performs better than conventional correlation-type and convolution-type interferometry when reconstructing surface waves, both in synthetic and real data. We use the dispersive behaviour of the reconstructed surface waves to infer the geological structure of the shallow subsurface.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. Měření indexu lomu vzduchu pomocí interferometrie nízké koherence

    Czech Academy of Sciences Publication Activity Database

    Pikálek, Tomáš; Buchta, Zdeněk

    2017-01-01

    Roč. 62, č. 10 (2017), s. 253-256 ISSN 0447-6441 R&D Projects: GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : air refractive index * laser interferometry * low-coherence interferometry Subject RIV: BH - Optics, Masers, Laser s OBOR OECD: Optics (including laser optics and quantum optics)

  11. 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.

  12. 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...

  13. 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

  14. A Transportable Gravity Gradiometer Based on Atom Interferometry

    Science.gov (United States)

    Yu, Nan; Thompson, Robert J.; Kellogg, James R.; Aveline, David C.; Maleki, Lute; Kohel, James M.

    2010-01-01

    A transportable atom interferometer-based gravity gradiometer has been developed at JPL to carry out measurements of Earth's gravity field at ever finer spatial resolutions, and to facilitate high-resolution monitoring of temporal variations in the gravity field from ground- and flight-based platforms. Existing satellite-based gravity missions such as CHAMP and GRACE measure the gravity field via precise monitoring of the motion of the satellites; i.e. the satellites themselves function as test masses. JPL's quantum gravity gradiometer employs a quantum phase measurement technique, similar to that employed in atomic clocks, made possible by recent advances in laser cooling and manipulation of atoms. This measurement technique is based on atomwave interferometry, and individual laser-cooled atoms are used as drag-free test masses. The quantum gravity gradiometer employs two identical atom interferometers as precision accelerometers to measure the difference in gravitational acceleration between two points (Figure 1). By using the same lasers for the manipulation of atoms in both interferometers, the accelerometers have a common reference frame and non-inertial accelerations are effectively rejected as common mode noise in the differential measurement of the gravity gradient. As a result, the dual atom interferometer-based gravity gradiometer allows gravity measurements on a moving platform, while achieving the same long-term stability of the best atomic clocks. In the laboratory-based prototype (Figure 2), the cesium atoms used in each atom interferometer are initially collected and cooled in two separate magneto-optic traps (MOTs). Each MOT, consisting of three orthogonal pairs of counter-propagating laser beams centered on a quadrupole magnetic field, collects up to 10(exp 9) atoms. These atoms are then launched vertically as in an atom fountain by switching off the magnetic field and introducing a slight frequency shift between pairs of lasers to create a moving

  15. 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)

  16. 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

  17. Protein diffusion coefficients determined by macroscopic-gradient Rayleigh interferometry and dynamic light scattering.

    Science.gov (United States)

    Annunziata, Onofrio; Buzatu, Daniela; Albright, John G

    2005-12-20

    Dynamic light scattering (DLS) is extensively used for measuring macromolecule diffusion coefficients. Contrary to classical techniques based on macroscopic concentration gradients, DLS probes microscopic fluctuations in concentration. DLS accuracy and its concordance with macroscopic-gradient techniques remains an outstanding important issue. We measured lysozyme diffusion coefficients in aqueous salt using both DLS and Rayleigh interferometry, a highly accurate macroscopic-gradient technique. The precision of our results is unprecedented. We find that our DLS values were systematically 2% higher than interferometry values. We believe that our interferometric measurements have produced the most accurate diffusion data ever reported for a protein, providing a new standard for quality control of DLS measurements. Furthermore, by interferometry, we have determined the whole diffusion coefficient matrix required for rigorously describing lysozyme-salt coupled diffusion. For the first time, we experimentally demonstrate that DLS does not provide the protein diffusion coefficient but one eigenvalue of the diffusion coefficient matrix.

  18. The correction of vibration in frequency scanning interferometry based absolute distance measurement system for dynamic measurements

    Science.gov (United States)

    Lu, Cheng; Liu, Guodong; Liu, Bingguo; Chen, Fengdong; Zhuang, Zhitao; Xu, Xinke; Gan, Yu

    2015-10-01

    Absolute distance measurement systems are of significant interest in the field of metrology, which could improve the manufacturing efficiency and accuracy of large assemblies in fields such as aircraft construction, automotive engineering, and the production of modern windmill blades. Frequency scanning interferometry demonstrates noticeable advantages as an absolute distance measurement system which has a high precision and doesn't depend on a cooperative target. In this paper , the influence of inevitable vibration in the frequency scanning interferometry based absolute distance measurement system is analyzed. The distance spectrum is broadened as the existence of Doppler effect caused by vibration, which will bring in a measurement error more than 103 times bigger than the changes of optical path difference. In order to decrease the influence of vibration, the changes of the optical path difference are monitored by a frequency stabilized laser, which runs parallel to the frequency scanning interferometry. The experiment has verified the effectiveness of this method.

  19. A portable magneto-optical trap with prospects for atom interferometry in civil engineering

    Science.gov (United States)

    Hinton, A.; Perea-Ortiz, M.; Winch, J.; Briggs, J.; Freer, S.; Moustoukas, D.; Powell-Gill, S.; Squire, C.; Lamb, A.; Rammeloo, C.; Stray, B.; Voulazeris, G.; Zhu, L.; Kaushik, A.; Lien, Y.-H.; Niggebaum, A.; Rodgers, A.; Stabrawa, A.; Boddice, D.; Plant, S. R.; Tuckwell, G. W.; Bongs, K.; Metje, N.; Holynski, M.

    2017-06-01

    The high precision and scalable technology offered by atom interferometry has the opportunity to profoundly affect gravity surveys, enabling the detection of features of either smaller size or greater depth. While such systems are already starting to enter into the commercial market, significant reductions are required in order to reach the size, weight and power of conventional devices. In this article, the potential for atom interferometry based gravimetry is assessed, suggesting that the key opportunity resides within the development of gravity gradiometry sensors to enable drastic improvements in measurement time. To push forward in realizing more compact systems, techniques have been pursued to realize a highly portable magneto-optical trap system, which represents the core package of an atom interferometry system. This can create clouds of 107 atoms within a system package of 20 l and 10 kg, consuming 80 W of power. This article is part of the themed issue 'Quantum technology for the 21st century'.

  20. Sensor influence in digital 3λ holographic interferometry

    International Nuclear Information System (INIS)

    Desse, J M; Picart, P; Tankam, P

    2011-01-01

    In digital holographic interferometry, the resolution of the reconstructed hologram depends on the pixel size and pixel number of the sensor used for recording. When different wavelengths are simultaneously used as a luminous source for the interferometer, the shape and the overlapping of three filters of a color sensor strongly influence the three reconstructed images. This problem can be directly visualized in 2D Fourier planes on red, green and blue channels. To better understand this problem and to avoid parasitic images generated at the reconstruction, three different sensors have been tested: a CCD sensor equipped with a Bayer filter, a Foveon sensor and a 3CCD sensor. The first one is a Bayer mosaic where one half of the pixels detect the green color and only one-quarter detect the red or blue color. As the missing data are interpolated among color detection positions, offsets and artifacts are generated. The second one is a specific sensor constituted with three stacked photodiode layers. Its technology is different from that of the classical color mosaic sensor because each pixel location detects the three colors simultaneously. So, the three colors are recorded simultaneously with identical spatial resolution, which corresponds to the spatial resolution of the sensor. However, the spectral curve of the sensor is large along each wavelength since the color segmentation is based on the penetration depth of the photons in silicon. Finally, with a 3CCD sensor, each image is recorded on three different sensors with the same resolution. In order to test the sensor influence, we have developed a specific optical bench which allows the near wake flow around a circular cylinder at Mach 0.45 to be characterized. Finally, best results have been obtained with the 3CDD sensor

  1. MEGARA Optics: Sub-aperture Stitching Interferometry for Large Surfaces

    Science.gov (United States)

    Aguirre-Aguirre, Daniel; Carrasco, Esperanza; Izazaga-Pérez, Rafael; Páez, Gonzalo; Granados-Agustín, Fermín; Percino-Zacarías, Elizabeth; Gil de Paz, Armando; Gallego, Jesús; Iglesias-Páramo, Jorge; Villalobos-Mendoza, Brenda

    2018-04-01

    In this work, we present a detailed analysis of sub-aperture interferogram stitching software to test circular and elliptical clear apertures with diameters and long axes up to 272 and 180 mm, respectively, from the Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía (MEGARA). MEGARA is a new spectrograph for the Gran Telescopio Canarias (GTC). It offers a resolution between 6000 and 20000 via the use of volume phase holographic gratings. It has an integral field unit and a set of robots for multi-object spectroscopy at the telescope focal plane. The output end of the fibers forms the spectrograph pseudo-slit. The fixed geometry of the collimator and camera configuration requires prisms in addition to the flat windows of the volume phase holographic gratings. There are 73 optical elements of large aperture and high precision manufactured in Mexico at the Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE) and the Centro de Investigaciones en Óptica (CIO). The principle of stitching interferometry is to divide the surface being tested into overlapping small sections, which allows an easier analysis (Kim & Wyant 1981). This capability is ideal for non-contact tests for unique and large optics as required by astronomical instruments. We show that the results obtained with our sub-aperture stitching algorithm were consistent with other methods that analyze the entire aperture. We used this method to analyze the 24 MEGARA prisms that could not be tested otherwise. The instrument has been successfully commissioned at GTC in all the spectral configurations. The fulfillment of the irregularity specifications was one of the necessary conditions to comply with the spectral requirements.

  2. Miniaturization of speckle interferometry for rapid strain analysis

    Science.gov (United States)

    Wegner, Ronny; Ettemeyer, Andreas

    1999-09-01

    Today's industry demands high-performance components meeting toughest mechanical features and ultimate safety standards. Especially in automotive and aircraft industry the development focuses on tailor-made design and solutions according to customer specifications. To reconcile economy, light-weight construction has become a key issue. Many companies are looking for new advanced strain/stress analysis techniques to improve cost efficiency and the limitations of classical methods. Detection of weak points and fatigue tests are carried out mainly with strain gauges which need careful application and experience. ESPI (electronic speckle pattern interferometry) allows a rapid, full field and 3D-measurement without contact. This paper presents the principle and application of a new miniaturized laser optical sensor combining contour and deformation measurement. In its basic employment ESPI is an interferometric method measuring deformations at modern working materials with high accuracy. Here also a module for contouring was developed and integrated into a single interferometer. Therefore even at complex components it is possible to measure and display strain-fields and -gradients with respect to the underlying contour. The new sensor is a unique device for flexible strain-analysis at welded-materials, extrusions, engines, car-bodies, etc. Without preparation and due to the full field and 3D- measurement 'hot spots' are shown, reducing the testing procedure and increasing the reliability of the complex component testing significantly. In this paper the recent development of a miniaturized ESPI-interferometer for strain and stress measurement is described. Advanced features according to classical techniques are specified and new applications in material and component testing are presented.

  3. Ka-band SAR interferometry studies for the SWOT mission

    Science.gov (United States)

    Fernandez, D. E.; Fu, L.; Rodriguez, E.; Hodges, R.; Brown, S.

    2008-12-01

    The primary objective of the NRC Decadal Survey recommended SWOT (Surface Water and Ocean Topography) Mission is to measure the water elevation of the global oceans, as well as terrestrial water bodies (such as rivers, lakes, reservoirs, and wetlands), to answer key scientific questions on the kinetic energy of ocean circulation, the spatial and temporal variability of the world's surface freshwater storage and discharge, and to provide societal benefits on predicting climate change, coastal zone management, flood prediction, and water resources management. The SWOT mission plans to carry the following suite of microwave instruments: a Ka-band interferometer, a dual-frequency nadir altimeter, and a multi-frequency water-vapor radiometer dedicated to measuring wet tropospheric path delay to correct the radar measurements. We are currently funded by the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP) to reduce the risk of the main technological drivers of SWOT, by addressing the following technologies: the Ka-band radar interferometric antenna design, the on-board interferometric SAR processor, and the internally calibrated high-frequency radiometer. The goal is to significantly enhance the readiness level of the new technologies required for SWOT, while laying the foundations for the next-generation missions to map water elevation for studying Earth. The first two technologies address the challenges of the Ka-band SAR interferometry, while the high- frequency radiometer addresses the requirement for small-scale wet tropospheric corrections for coastal zone applications. In this paper, we present the scientific rational, need and objectives behind these technology items currently under development.

  4. 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.

  5. Local earthquake interferometry of the IRIS Community Wavefield Experiment, Grant County, Oklahoma

    Science.gov (United States)

    Eddy, A. C.; Harder, S. H.

    2017-12-01

    The IRIS Community Wavefield Experiment was deployed in Grant County, located in north central Oklahoma, from June 21 to July 27, 2016. Data from all nodes were recorded at 250 samples per second between June 21 and July 20 along three lines. The main line was 12.5 km long oriented east-west and consisted of 129 nodes. The other two lines were 5.5 km long north-south oriented with 49 nodes each. During this time, approximately 150 earthquakes of magnitude 1.0 to 4.4 were recorded in the surrounding counties of Oklahoma and Kansas. Ideally, sources for local earthquake interferometry should be near surface events that produce high frequency body waves. Unlike ambient noise seismic interferometry (ANSI), which uses days, weeks, or even months of continuously recorded seismic data, local earthquake interferometry uses only short segments ( 2 min.) of data. Interferometry in this case is based on the cross-correlation of body wave surface multiples where the event source is translated to a reference station in the array, which acts as a virtual source. Multiples recorded between the reference station and all other stations can be cross-correlated to produce a clear seismic trace. This process will be repeated with every node acting as the reference station for all events. The resulting shot gather will then be processed and analyzed for quality and accuracy. Successful application of local earthquake interferometry will produce a crustal image with identifiable sedimentary and basement reflectors and possibly a Moho reflection. Economically, local earthquake interferometry could lower the time and resource cost of active and passive seismic surveys while improving subsurface image quality in urban settings or areas of limited access. The applications of this method can potentially be expanded with the inclusion of seismic events with a magnitude of 1.0 or lower.

  6. Demonstration of Geometric Landau-Zener Interferometry in a Superconducting Qubit

    Science.gov (United States)

    Tan, Xinsheng; Zhang, Dan-Wei; Zhang, Zhentao; Yu, Yang; Han, Siyuan; Zhu, Shi-Liang

    2014-01-01

    Geometric quantum manipulation and Landau-Zener interferometry have been separately explored in many quantum systems. In this Letter, we combine these two approaches to study the dynamics of a superconducting phase qubit. We experimentally demonstrate Landau-Zener interferometry based on the pure geometric phases in this solid-state qubit. We observe the interference caused by a pure geometric phase accumulated in the evolution between two consecutive Landau-Zener transitions, while the dynamical phase is canceled out by a spin-echo pulse. The full controllability of the qubit state as a function of the intrinsically robust geometric phase provides a promising approach for quantum state manipulation.

  7. Application of optical single-sideband laser in Raman atom interferometry

    Science.gov (United States)

    Zhu, Lingxiao; Lien, Yu-Hung; Hinton, Andrew; Niggebaum, Alexander; Rammeloo, Clemens; Bongs, Kai; Holynski, Michael

    2018-03-01

    A frequency doubled I/Q modulator based optical single-sideband (OSSB) laser system is demonstrated for atomic physics research, specifically for atom interferometry where the presence of additional sidebands causes parasitic transitions. The performance of the OSSB technique and the spectrum after second harmonic generation are measured and analyzed. The additional sidebands are removed with better than 20 dB suppression, and the influence of parasitic transitions upon stimulated Raman transitions at varying spatial positions is shown to be removed beneath experimental noise. This technique will facilitate the development of compact atom interferometry based sensors with improved accuracy and reduced complexity.

  8. Precise signal amplitude retrieval for a non-homogeneous diagnostic beam using complex interferometry approach

    Czech Academy of Sciences Publication Activity Database

    Krupka, Michal; Kálal, Milan; Dostál, Jan; Dudžák, Roman; Juha, Libor

    2017-01-01

    Roč. 12, August (2017), č. článku C08012. ISSN 1748-0221. [European Conference on Plasma Diagnostics (ECPD2017)/2./. Bordeaux, 18.04.2017-21.04.2017] R&D Projects: GA MŠk(CZ) LM2015083 Institutional support: RVO:61389021 Keywords : Image processing * Interferometry * Plasma diagnostics - interferometry * Spectroscopy and imaging Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: 2.11 Other engineering and technologies Impact factor: 1.220, year: 2016

  9. Generation of interferogram for D-InSAR based on contoured correlation interferometry

    Science.gov (United States)

    Long, Xuejun; Fu, Sihua; Yu, Qifeng; Yang, Xia

    2009-10-01

    Synthetic Aperture Radar interferometry (InSAR) is a rapidly developing technique for earth observation. Differential InSAR (D-InSAR) technique, based on InSAR, is a new method for earthquake deformation detection and land subsidence monitoring. In this paper, an innovative method of generation of interferogram for D-InSAR based on contoured correlation interferometry (CCI) is presented, which may directly generate interferogram with almost no speckle noise or blurring. The data processing results of the Mani earthquake indicate that D-InSAR CCI method can effectively reduce or even remove the decorrelation noise, even in the area with serious decorrelation.

  10. 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

  11. 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

  12. Refractive Index Measurement of Fibers Through Fizeau Interferometry

    Science.gov (United States)

    2013-08-01

    Aperture Edmund Optics, Inc. (Barrington, NJ) NT53-915 Collimating lens CVI Melles Griot (Albuquerque, NM) LPX-75.0-96.0-C-SLMF-400-700 Polarizer CVI...Melles Griot FPG-50.8-5.3 Mirror CVI Melles Griot PAV-MPG-5010M-LEBG Optical flats CVI Melles Griot PR1-589-70-2037 CCD camera Lumenera Corp

  13. 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.

  14. 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

  15. 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

  16. Polarization-free Cubic Phase GaN Ultraviolet Laser Diodes for Space-based Light Interferometry

    Data.gov (United States)

    National Aeronautics and Space Administration — Laser diodes have many advantages over other forms of lasers: extremely compact (<1cm in length), inexpensive and simple designs that can achieve high power, high...

  17. 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

  18. 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

  19. 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...

  20. Nuclear medicine image registration by spatially noncoherent interferometry.

    Science.gov (United States)

    Scheiber, C; Malet, Y; Sirat, G; Grucker, D

    2000-02-01

    This article introduces a technique for obtaining high-resolution body contour data in the same coordinate frame as that of a rotating gamma camera, using a miniature range finder, the conoscope, mounted on the camera gantry. One potential application of the technique is accurate coregistration in longitudinal brain SPECT studies, using the face of the patient (or "mask"), instead of SPECT slices, to coregister subsequent acquisitions involving the brain. Conoscopic holography is an interferometry technique that relies on spatially incoherent light interference in birefringent crystals. In this study, the conoscope was used to measure the absolute distance (Z) between a light source reflected from the skin and its observation plane. This light was emitted by a 0.2-mW laser diode. A scanning system was used to image the face during SPECT acquisition. The system consisted of a motor-driven mirror (Y axis) and the gamma-camera gantry (1 profile was obtained for each rotation step, X axis). The system was calibrated to place the conoscopic measurements and SPECT slices in the same coordinate frame. Through a simple and robust calibration of the system, the SE for measurements performed on geometric shapes was less than 2 mm, i.e., less than the actual pixel size of the SPECT data. Biometric measurements of an anthropomorphic brain phantom were within 3%-5% of actual values. The mask data were used to register images of a brain phantom and of a volunteer's brain, respectively. The rigid transformation that allowed the merging of masks by visual inspection was applied to the 2 sets of SPECT slices to perform the fusion of the data. At the cost of an additional low-cost setup integrated into the gamma-camera gantry, real-time data about the surface of the head were obtained. As in all other surface-based techniques (as opposed to volume-based techniques), this method allows the match of data independently from the dataset of interest and facilitates further registration

  1. Analysis of error functions in speckle shearing interferometry

    International Nuclear Information System (INIS)

    Wan Saffiey Wan Abdullah

    2001-01-01

    Electronic Speckle Pattern Shearing Interferometry (ESPSI) or shearography has successfully been used in NDT for slope (∂w/ (∂x and / or (∂w/ (∂y) measurement while strain measurement (∂u/ ∂x, ∂v/ ∂y, ∂u/ ∂y and (∂v/ (∂x) is still under investigation. This method is well accepted in industrial applications especially in the aerospace industry. Demand of this method is increasing due to complexity of the test materials and objects. ESPSI has successfully performed in NDT only for qualitative measurement whilst quantitative measurement is the current aim of many manufacturers. Industrial use of such equipment is being completed without considering the errors arising from numerous sources, including wavefront divergence. The majority of commercial systems are operated with diverging object illumination wave fronts without considering the curvature of the object illumination wavefront or the object geometry, when calculating the interferometer fringe function and quantifying data. This thesis reports the novel approach in quantified maximum phase change difference analysis for derivative out-of-plane (OOP) and in-plane (IP) cases that propagate from the divergent illumination wavefront compared to collimated illumination. The theoretical of maximum phase difference is formulated by means of three dependent variables, these being the object distance, illuminated diameter, center of illuminated area and camera distance and illumination angle. The relative maximum phase change difference that may contributed to the error in the measurement analysis in this scope of research is defined by the difference of maximum phase difference value measured by divergent illumination wavefront relative to the maximum phase difference value of collimated illumination wavefront, taken at the edge of illuminated area. Experimental validation using test objects for derivative out-of-plane and derivative in-plane deformation, using a single illumination wavefront

  2. Looking inside the microseismic cloud using seismic interferometry

    Science.gov (United States)

    Matzel, E.; Rhode, A.; Morency, C.; Templeton, D. C.; Pyle, M. L.

    2015-12-01

    Microseismicity provides a direct means of measuring the physical characteristics of active tectonic features such as fault zones. Thousands of microquakes are often associated with an active site. This cloud of microseismicity helps define the tectonically active region. When processed using novel geophysical techniques, we can isolate the energy sensitive to the faulting region, itself. The virtual seismometer method (VSM) is a technique of seismic interferometry that provides precise estimates of the GF between earthquakes. In many ways the converse of ambient noise correlation, it is very sensitive to the source parameters (location, mechanism and magnitude) and to the Earth structure in the source region. In a region with 1000 microseisms, we can calculate roughly 500,000 waveforms sampling the active zone. At the same time, VSM collapses the computation domain down to the size of the cloud of microseismicity, often by 2-3 orders of magnitude. In simple terms VSM involves correlating the waveforms from a pair of events recorded at an individual station and then stacking the results over all stations to obtain the final result. In the far-field, when most of the stations in a network fall along a line between the two events, the result is an estimate of the GF between the two, modified by the source terms. In this geometry each earthquake is effectively a virtual seismometer recording all the others. When applied to microquakes, this alignment is often not met, and we also need to address the effects of the geometry between the two microquakes relative to each seismometer. Nonetheless, the technique is quite robust, and highly sensitive to the microseismic cloud. Using data from the Salton Sea geothermal region, we demonstrate the power of the technique, illustrating our ability to scale the technique from the far-field, where sources are well separated, to the near field where their locations fall within each other's uncertainty ellipse. VSM provides better

  3. 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...

  4. 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...

  5. 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...

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. Azimuthally sensitive Hanbury Brown-Twiss interferometry measured with the ALICE experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gramling, Johanna Lena

    2011-07-01

    Bose-Einstein correlations of identical pions emitted in high-energy particle collisions provide information about the size of the source region in space-time. If analyzed via HBT Interferometry in several directions with respect to the reaction plane, the shape of the source can be extracted. Hence, HBT Interferometry provides an excellent tool to probe the characteristics of the quark-gluon plasma possibly created in high-energy heavy-ion collisions. This thesis introduces the main theoretical concepts of particle physics, the quark gluon plasma and the technique of HBT interferometry. The ALICE experiment at the CERN Large Hadron Collider (LHC) is explained and the first azimuthallyintegrated results measured in Pb-Pb collisions at √(s{sub NN})=2.76 TeV with ALICE are presented. A detailed two-track resolution study leading to a global pair cut for HBT analyses has been performed, and a framework for the event plane determination has been developed. The results from azimuthally sensitive HBT interferometry are compared to theoretical models and previous measurements at lower energies. Oscillations of the transverse radii in dependence on the pair emission angle are observed, consistent with a source that is extended out-of-plane.

  15. A new method of electron density measurement by Fabry-Perot interferometry

    International Nuclear Information System (INIS)

    Hojo, Hitoshi; Mase, Atsushi

    2004-01-01

    A new method for determining the electron density of a thin plasma by means of Fabry-Perot interferometry is proposed. The interferometer consists of two plasma layers and dielectric material surrounded by two plasma layers. The transmittance of electromagnetic waves across the interferometer is calculated, and Fabry-Perot resonances are frequency when the width of a plasma layer is known. (author)

  16. Optical interferometry methods used to study stress wave propagetion in a human skull

    Czech Academy of Sciences Publication Activity Database

    Trnka, Jan; Dvořáková, Pavla; Veselý, Eduard

    2004-01-01

    Roč. 2, č. 3 (2004), s. 29-34 ISSN 0732-8818 R&D Projects: GA AV ČR IAA2076904 Institutional research plan: CEZ:AV0Z2076919 Keywords : double-pulse * holo-interferometry * stress waves Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.322, year: 2004

  17. Evaluation of back scatter interferometry, a method for detecting protein binding in solution

    DEFF Research Database (Denmark)

    Jepsen, S. T.; Jørgensen, Thomas Martini; Zong, Weiyong

    2015-01-01

    Back Scatter Interferometry (BSI) has been proposed to be a highly sensitive and versatile refractive index sensor usable for analytical detection of biomarker and protein interactions in solution. However the existing literature on BSI lacks a physical explanation of why protein interactions...

  18. Analysis of capillary interferometry for measuring refractive indices of minute samples.

    Science.gov (United States)

    Qi, Shengwen; Yang, Xiuqin; Zhang, Chunping; Zhang, Lianshun; Wang, Xinyu; Xu, Tang; Tian, Jianguo; Zhang, Guangyin

    2004-01-20

    A method of measuring the refractive indices of minute samples by analyzing capillary interferometry is introduced. With the interference theory of light, the intensity distribution of an interference fringe pattern formed by a cylindrical tube of a capillary is obtained, and the influence of some parameters on the fringes are discussed. The measurement accuracy and its relative problems are analyzed.

  19. Novel implementation of an ISO standard method for primary vibration calibration by laser interferometry

    CSIR Research Space (South Africa)

    Veldman, CS

    2003-01-01

    Full Text Available An implementation of the sine-approximation method of ISO 16063-11 (primary vibration calibration by laser interferometry) is described. The quadrature interference signals are generated using an interferometer as described in method 3 of ISO 16063...

  20. Thermal and electrical properties of porphyrin derivatives and their relevance for molecule interferometry

    NARCIS (Netherlands)

    Deachapunya, S.; Stefanov, A.; Berninger, M.; Ulbricht, H.; Reiger, E.; Doltsinis, N.L.; Arndt, M.

    2007-01-01

    The authors present new measurements of thermal and electrical properties for two porphyrin derivatives. They determine their sublimation enthalpy from the temperature dependence of the effusive beam intensity. The authors study H2TPP and Fe(TPP)Cl in matter-wave interferometry. Both molecules have

  1. Speckle Interferometry with the McMath-Pierce East Auxiliary Telescope

    Science.gov (United States)

    Harshaw, Richard; Ray, Jimmy; Douglass, David; Prause, Lori; Genet, Russell

    2015-09-01

    Engineering runs and tests on the McMath-Pierce 0.8 meter East Auxiliary telescope successfully configured the telescope for speckle interferometry observations of close visual double stars. This paper reports the procedure and results of the speckle analysis of four double stars.

  2. Decoherence dynamics in interferometry with one-dimensional bose-einstein condensates

    DEFF Research Database (Denmark)

    Schumm, Thorsten; Hofferberth, Sebastian; Schmiedmayer, Jörg

    2007-01-01

    We perform interferometry with one-dimensional Bose-Einstein condensates in a double well potential. Using dressed adiabatic potentials on an atomchip, we dynamically split BECs, imposing a macroscopic coherence on the system. Fluctuations of the order parameter are revealed as local shifts in th...

  3. Influence of error sources in speckle interferometry using only two speckle patterns

    Science.gov (United States)

    Arai, Yasuhiko

    2016-12-01

    Speckle interferometry is an important deformation measurement method for objects with rough surfaces. Recently, a fringe analysis method that uses only one speckle pattern before deformation and one after deformation was proposed. The measurement accuracy of this method is known to depend on experimental conditions. In this paper, the improvement of the measurement accuracy of this method is discussed in comparison with the advanced technologies of off-axis digital holography. It is highly effective to introduce the experiences of the advanced technologies of digital holography to speckle interferometry. However, it should also be considered that both technologies have different purposes. Because digital holography is basically a technology which records images, the influence of the quantity of deformation has never been discussed in digital holography in detail. In this study, the measurement accuracy of speckle interferometry is investigated through a precise comparison of the experimental results from both technologies. It was confirmed that the conditions for digital holography are not always suitable for improving the measurement accuracy of speckle interferometry.

  4. Laboratoř interferometrie a vysoce koherentních laserů

    Czech Academy of Sciences Publication Activity Database

    Lazar, Josef; Číp, Ondřej; Petrů, František; Jedlička, Petr; Mikel, Břetislav; Růžička, Bohdan; Buchta, Zdeněk; Matoušek, Vít

    2006-01-01

    Roč. 51, č. 1 (2006), s. 4-6 ISSN 0447-6441 R&D Projects: GA ČR GA102/04/2109; GA AV ČR IAA200650504; GA AV ČR KJB200650503 Institutional research plan: CEZ:AV0Z20650511 Keywords : stabilized lasers * interferometry * refractometry Subject RIV: BH - Optics, Masers, Lasers

  5. Preliminary interferometry measurements of a flow field around fluttering NACA0015 profile

    Czech Academy of Sciences Publication Activity Database

    Vlček, Václav; Kozánek, Jan

    2011-01-01

    Roč. 56, č. 4 (2011), s. 379-387 ISSN 0001-7043 R&D Projects: GA ČR GA101/09/1522 Institutional research plan: CEZ:AV0Z20760514 Keywords : self-excited vibration * airfoil * aerodynamic tunnel * interferometry Subject RIV: BI - Acoustics http://journal.it.cas.cz

  6. Using Airborne SAR Interferometry to Measure the Elevation of a Greenland Ice Cap

    DEFF Research Database (Denmark)

    Dall, Jørgen; Keller, K.; Madsen, S.N.

    2000-01-01

    A digital elevation model (DEM) of an ice cap in Greenland has been generated from airborne SAR interferometry data, calibrated with a new algorithm, and compared with airborne laser altimetry profiles and carrier-phase differential GPS measurements of radar reflectors deployed on the ice cap...

  7. Use of seismic interferometry to improve the imaging of a heterogeneous landfill

    NARCIS (Netherlands)

    Konstantaki, L.A.; Draganov, D.S.; Ghose, R.; Heimovaara, T.J.

    2015-01-01

    In this study we investigate the application of seismic interferometry (SI) to seismic reflection data recorded over a landfill. Landfills represent strongly heterogeneous subsurfaces making the seismic reflection imaging challenging. We show that SI improves the imaging of high-density areas, which

  8. Radar Interferometry Detection of Hinge Line Migration on Rutford Ice Stream and Carlson Inlet, Antarctica

    Science.gov (United States)

    Rignot, Eric

    1997-01-01

    Satellite synthetic-aperture radar (SAR) Interferometry is employed to map the hinge line, or limit of tidal flexing, of Rutford Ice Stream and Carlson Inlet, Antarctica, and detect its migration between 1992 and 1996. The hinge line is mapped using a model fit from an elastic beam theory.

  9. Quantification of the neutron dark-field imaging signal in grating interferometry

    Czech Academy of Sciences Publication Activity Database

    Grünzweig, C.; Kopeček, Jaromír; Betz, B.; Kaestner, A.; Jefimovs, K.; Kohlbrecher, J.; Gasser, U.; Bunk, O.; David, C.; Lehmann, E.; Donath, T.; Pfeiffer, F.

    2012-01-01

    Roč. 88, č. 12 (2012), "125104-1"-"125104-6" ISSN 1098-0121 Institutional support: RVO:68378271 Keywords : neutron scattering (including small - angle scattering ) * atom and neutron interferometry Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.767, year: 2012

  10. Modeling surface deformation observed with synthetic aperture radar interferometry at Campi Flegrei caldera

    NARCIS (Netherlands)

    Lundgren, P.; Usai, S.; Sansosti, E.; Lanari, R.; Tesauro, M.; Fornaro, G.; Berardino, P.

    2001-01-01

    Satellite radar interferometry of Campi Flegrei caldera, Italy, reveals a pattern of subsidence during the period 1993–1998. Interferograms spanning the first half of the observation period (1993–1995) have a lower amplitude and average rate of subsidence than those spanning either the second half

  11. Measurement of the influence of dispersion on white-light interferometry

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, Pavel; Soubusta, Jan

    2004-01-01

    Roč. 43, č. 4 (2004), s. 766-770 ISSN 0003-6935 R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010921 Keywords : white-light interferometry * height profile * smooth surface Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.799, year: 2004

  12. First Beam Test of Nanometer Spot Size Monitor Using Laser Interferometry

    CERN Document Server

    Walz, D

    2003-01-01

    The nanometer spot size monitor based on the laser interferometry (Laser-Compton Spot Size Monitor) has been tested in FFTB beam line at SLAC. A low emittance beam of 46 GeV electrons, provided by the two-mile linear accelerator, was focused into nanometer spot in the FFTB line, and its transverse dimensions were precisely measured by the spot size monitor.

  13. Reflection imaging of the Moon's interior using deep-moonquake seismic interferometry

    NARCIS (Netherlands)

    Nishitsuji, Y.; Rowe, CA; Wapenaar, C.P.A.; Draganov, D.S.

    2016-01-01

    The internal structure of the Moon has been investigated over many years using a variety of seismic methods, such as travel time analysis, receiver functions, and tomography. Here we propose to apply body-wave seismic interferometry to deep moonquakes in order to retrieve zero-offset reflection

  14. A Study of Wave Propagation in a Human Skull Using Laser Interferometry

    Czech Academy of Sciences Publication Activity Database

    Trnka, Jan; Veselý, Eduard; Dvořáková, Pavla

    vol.2, č. 1 (2004), s. 27-30 ISSN 0732-8818 R&D Projects: GA AV ČR IAA2076904 Institutional research plan: CEZ:AV0Z2076919 Keywords : laser interferometry * human skull * guided waves Subject RIV: BH - Optics, Masers, Laser s Impact factor: 0.322, year: 2004

  15. Methods of direct measurement of the refraction index of air using high-resolution laser interferometry

    Czech Academy of Sciences Publication Activity Database

    Číp, Ondřej; Petrů, František; Matoušek, V.; Buchta, Z.; Lazar, Josef

    2004-01-01

    Roč. 49, č. 3 (2004), s. 88-90 ISSN 0447-6441 R&D Projects: GA AV ČR IBS2065009 Keywords : laser interferometry * refraction index * Fabry-Perot interferometer Subject RIV: BH - Optics, Masers, Lasers

  16. Soft-X-Ray Laser Interferometry of a Dense Plasma using a Lloyd mirror.

    Science.gov (United States)

    Moreno, C. H.; Marconi, M. C.; Kanizay, K.; Rocca, J. J.

    1998-11-01

    X-Ray lasers can significantly expand the maximum plasma size and electron densities accessible to laser interferometry. Recently, a soft-x-ray laser pumped by the NOVA laser at LLNL was used in combination with a Mach-Zehnder interferometer to study large-scale laser-created plasmas(L.B. Da Silva et al), Phys. Rev. Lett. 74, 3991, (1995). The recent demonstration of saturated discharge-pumped soft x-ray laser(J.J. Rocca et al), Phys. Rev. Lett. 77, 1476, (1996) opened the possibility of conducting soft x-ray laser interferometry of dense plasmas with a table-top laser. The subsequent measurement of the spatial coherence of this laser(M. Marconi et al), Phys. Rev. Lett., 79, 2799, (1997) gave additional support to this possibility. In this communication we report the first demonstration of soft x-ray plasma interferometry experiment performed with a table-top laser. A capillary discharge-pumped 46.9 nm laser was used in combination with a Lloyd mirror to perform time resolved interferometry in a pinch discharge. Analysis of the interferograms allowed to quantify the spatial distribution of the electron density in the region adjacent to the cathode. This work was supported by DOE grant DE-FG03-98DP00208. We also acknowledge the support of NSF for the development of the laser.

  17. Iceland rising : Solid Earth response to ice retreat inferred from satellite radar interferometry and visocelastic modeling

    NARCIS (Netherlands)

    Auriac, A.; Spaans, K.H.; Sigmundsson, F.; Hooper, A.; Schmidt, P.; Lund, B.

    2013-01-01

    A broad uplift occurs in Iceland in response to the retreat of ice caps, which began circa 1890. Until now, this deformation signal has been measured primarily using GPS at points some distance away from the ice caps. Here, for the first time we use satellite radar interferometry (interferometric

  18. Anthropogenic impact signatures revealed in the travelling ionospheric disturbances by regional GPS interferometry

    Science.gov (United States)

    Zakharov, V. I.; Ilyushin, Ya A.

    2018-01-01

    With the technique of the radio interferometry of the navigational satellite signals, we investigate the travelling ionospheric disturbances generated by large urban agglomeration. We resolve detailed structure of the ionospheric disturbances field and attribute disturbances to particular atmospheric wave sources in the agglomeration. Wave generation efficiency revealed from the observational data well agrees with the theoretical prediction derived from energetic considerations.

  19. Bayesian Analysis of Systematic Effects in Interferometric Observations of the Cosmic Microwave Background Polarization

    Science.gov (United States)

    Karakci, Ata; Zhang, L.; Sutter, P. M.; Bunn, E. F.; Korotkov, A.; Timbie, P. T.; Tucker, G. S.; Wandelt, B.

    2013-06-01

    The detection of the primordial B-mode spectrum of the polarized cosmic microwave background (CMB) signal may provide a probe of inflation. However, observation of such a faint signal requires excellent control of systematic errors. Interferometry proves to be a promising approach for overcoming such a challenge. In this thesis we present a complete simulation pipeline of interferometric observations of CMB polarization, including systematic errors. We employ a method for Bayesian inference of power spectra and signal reconstruction from interferometric data of the CMB polarization signal by using the technique of Gibbs sampling. Several categories of systematic errors are considered: instrumental errors, consisting of antenna gain and antenna coupling errors, and beam errors, consisting of antenna pointing errors, beam cross-polarization and beam shape (and size) errors. In order to recover the tensor-to-scalar ratio, r, within a 10% tolerance level, which ensures the experiment is sensitive enough to detect the B-signal at r=0.01 in the multipole range 28 QUBIC-like experiment, Gaussian-distributed systematic errors must be controlled with precisions of |g_rms| = 0.1 for antenna gain, |e_rms| = 5e-4 for antenna coupling, d_rms ~ 0.7 degrees for pointing, z_rms ~ 0.7 degrees for beam shape, and m_rms = 5e-4 for beam cross-polarization.

  20. An improved method for polarimetric image restoration in interferometry

    Science.gov (United States)

    Pratley, Luke; Johnston-Hollitt, Melanie

    2016-11-01

    Interferometric radio astronomy data require the effects of limited coverage in the Fourier plane to be accounted for via a deconvolution process. For the last 40 years this process, known as `cleaning', has been performed almost exclusively on all Stokes parameters individually as if they were independent scalar images. However, here we demonstrate for the case of the linear polarization P, this approach fails to properly account for the complex vector nature resulting in a process which is dependent on the axes under which the deconvolution is performed. We present here an improved method, `Generalized Complex CLEAN', which properly accounts for the complex vector nature of polarized emission and is invariant under rotations of the deconvolution axes. We use two Australia Telescope Compact Array data sets to test standard and complex CLEAN versions of the Högbom and SDI (Steer-Dwedney-Ito) CLEAN algorithms. We show that in general the complex CLEAN version of each algorithm produces more accurate clean components with fewer spurious detections and lower computation cost due to reduced iterations than the current methods. In particular, we find that the complex SDI CLEAN produces the best results for diffuse polarized sources as compared with standard CLEAN algorithms and other complex CLEAN algorithms. Given the move to wide-field, high-resolution polarimetric imaging with future telescopes such as the Square Kilometre Array, we suggest that Generalized Complex CLEAN should be adopted as the deconvolution method for all future polarimetric surveys and in particular that the complex version of an SDI CLEAN should be used.

  1. 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

  2. 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...

  3. Study on a multi-delay spectral interferometry for stellar radial velocity measurement

    Science.gov (United States)

    Zhang, Kai; Jiang, Haijiao; Tang, Jin; Ji, Hangxin; Zhu, Yongtian; Wang, Liang

    2014-08-01

    High accuracy radial velocity measurement isn't only one of the most important methods for detecting earth-like Exoplanets, but also one of the main developing fields of astronomical observation technologies in future. Externally dispersed interferometry (EDI) generates a kind of particular interference spectrum through combining a fixed-delay interferometer with a medium-resolution spectrograph. It effectively enhances radial velocity measuring accuracy by several times. Another further study on multi-delay interferometry was gradually developed after observation success with only a fixed-delay, and its relative instrumentation makes more impressive performance in near Infrared band. Multi-delay is capable of giving wider coverage from low to high frequency in Fourier field so that gives a higher accuracy in radial velocity measurement. To study on this new technology and verify its feasibility at Guo Shoujing telescope (LAMOST), an experimental instrumentation with single fixed-delay named MESSI has been built and tested at our lab. Another experimental study on multi-delay spectral interferometry given here is being done as well. Basically, this multi-delay experimental system is designed in according to the similar instrument named TEDI at Palomar observatory and the preliminary test result of MESSI. Due to existence of LAMOST spectrograph at lab, a multi-delay interferometer design actually dominates our work. It's generally composed of three parts, respectively science optics, phase-stabilizing optics and delay-calibrating optics. To switch different fixed delays smoothly during observation, the delay-calibrating optics is possibly useful to get high repeatability during switching motion through polychromatic interferometry. Although this metrology is based on white light interferometry in theory, it's different that integrates all of interference signals independently obtained by different monochromatic light in order to avoid dispersion error caused by

  4. 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.

  5. 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 ...

  6. 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

  7. 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

  8. 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.

  9. 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)

  10. 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.

  11. Investigation of intracavity phase interferometry applied to nano-metrology

    Science.gov (United States)

    Luo, Xuan

    Intracavity phase interferometry is sensing technique developed at UNM, in which a physical quantity to be measured is put as integral part of a mode-locked laser. It relies on the fact that any intracavity phase shift of an intracavity pulse will result in a frequency change of the whole pulse train. The implementations of IPI requires the operation of a mode-locked laser in which two pulses circulate independently, i.e. with no phase coupling between them. IPI has been demonstrated with a variety of laser systems, to detect either non-reciprocal effects (such as rotation, magnetic field), or phase changes that can be made periodic at the repetition rate of the laser cavity. The purpose of this work is to study the feasibility of applying this technique to the measurement of non-periodic (i.e. slow) changes in optical path. The new concept to measure sub-nanometer displacement uses an optoelectronic modulator (EOM) inside the cavity. The operation of the mode-locked laser after insertion of such an element in its cavity is analyzed. Several laser systems have been tried for the implementation of IPI. Two of them are presented in this thesis. The first one is a Nd:YVO4 laser, mode-locked by a multiple quantum wells (MQW) saturable absorber. The presence of a solid state saturable absorber introduced a dead band in the beat note response of the system. A new coupling between group and phase velocity was discovered experimentally, and explained through simulation. This coupling affects negatively the operation of the system, since the repetition rate is no longer a reliable fixed quantity. The coupling could be eliminated by replacing the MQW with a dye jet absorber. A first demonstration of a slow optical path change (in the nm range) was made. The system that appeared at first the most promising is the intracavity optical parametric oscillator (OPO) synchronously pumped by a mode-locked Ti:Sapphire lasers. Bringing the unstable behavior of that laser under control

  12. A new laser cooling method for lithium atom interferometry

    Science.gov (United States)

    Kim, Geena

    An atom interferometer offers means to measure physical constants and physical quantities with a high precision, with relatively low cost and convenience as a table-top experiment. A precision measurement of a gravitational acceleration can test fundamental physics concepts such as Einstein equivalence principle (EEP). We identified that the two lithium isotopes (7Li and 6Li) have an advantage for the test of EEP, according to the standard model extension (SME). We aim to build the world's first lithium atom interferometer and test the Einstein equivalence principle. We demonstrate a new laser cooling method suitable for a lithium atom interferometer. Although lithium is often used in ultra-cold atom experiments for its interesting physical properties and measurement feasibility, it is more difficult to laser cool lithium than other alkali atoms due to its unresolved hyperfine states, light mass (large recoil velocity) and high temperature from the oven. Typically, standard laser cooling techniques such as Zeeman slowers and magneto-optical traps are used to cool lithium atoms to about 1 mK, and the evaporative cooling method is used to cool lithium atoms to a few muK for Bose-Einstein condensate (BEC) experiments. However, for the atom interferometry purpose, the evaporative cooling method is not ideal for several reasons: First, its cooling efficiency is so low (0.01 % or less) that typically only 104-105 atoms are left after cooling when one begins with 10. 9 atoms. More atoms in anatom interferometer are needed to have a better signal to noise ratio. Second, an evaporative cooling is used to make a BEC, but we do not need a BEC to make an atom interferometer. In an atom interferometer, a high density of atoms as in a BEC should be avoided since it causes a phase shift due to atom interactions. Third, a setup for an evaporative cooling requires intricate RF generating coils or a high power laser. With a simple optical lattice and a moderate laser power (100 m

  13. Assessing natural hazards in NE Colombia using Sentinel-1 interferometry

    Science.gov (United States)

    Olen, Stephanie; Bookhagen, Bodo

    2017-04-01

    The DIGENTI project (Digitaler Entscheidertisch für das Naturgefahrenmanagement auf Basis von Satellitendaten und VGI (Volunteered Geographic Information)) aims to assess the natural hazard threat to the Cesar and La Guajira departments of northeast Colombia as guidance for decision makers and disaster relief workers. As members of the DIGENTI project, we use Sentinel-1 synthetic aperture radar (SAR) interferometry to detect hillslope movements, delineate settlements, and monitor damage to urban areas. Our study area, located in the remote Serranía del Perijá mountain range on the border of Colombia and Venezuela, is mountainous, highly vegetated, and experiences high and spatially variable rainfall (between 1 and 4 m a-1). The remote nature of the region, coupled with the favorable conditions for mass movements and other hillslope instabilities, make it an ideal location to employ remote sensing techniques to monitor potential natural hazards. In the highly vegetated Serranía del Perijá mountain range, traditional damage proxy mapping is complicated by vegetation-related coherence loss between SAR scenes. Cross-referencing existing maps, we define regions of consistently high coherence as settled or urban areas. Using the spatial extent of settled or urban areas as a mask, we establish an algorithm to use coherence loss only in these regions as a damage proxy in urban areas where the local population will be most affected. Outside of settlements, hillslope instabilities and movements are quantified and mapped using a two-prong approach: (1) Horizontal ground displacement is be calculated by dense amplitude cross-correlation using the topsOffsetApp in the InSAR Scientific Computing Environment (ISCE). This allows the location, direction, and magnitude of mass movements and hillslope instabilities to be identified and mapped; (2) We use a timeseries of interferograms to quantify vertical ground deformation (e.g., as caused by landsliding) during the Sentinel-1

  14. Water induced geohazards measured with spaceborne interferometry techniques

    Science.gov (United States)

    Poncos, V.; Serban, F.; Teleaga, D.; Ciocan, V.; Sorin, M.; Caranda, D.; Zamfirescu, F.; Andrei, M.; Copaescu, S.; Radu, M.; Raduca, V.

    2012-04-01

    Natural and anthropogenic occurrence of groundwater is inducing surficial crustal deformation processes that can be accurately measured with high spatial density from space, regardless of the ground access conditions. The detection of the surface deformation allows uncovering spatial and temporal patterns of subsurface processes such as land subsidence, cave-ins and differential ground settlement related to water content. InSAR measurements combined with ground truth data permit estimation of the mechanical properties of the rocks and the development of models and scenarios to predict disaster events such as cave-ins, landslides and soil liquefaction in the case of an Earthquake. A number of three sites in Romania that suffer of ground instability because of the water component will be presented. The DInSAR, Interferograms Stacking and Persistent Scatterers Interferometry techniques were applied to retrieve as accurate as possible the displacement information. The first studied site is the city of Bucharest; using 7 years of ERS data ground instability was detected on a large area that represents the historical watershed of the Dambovita river. A network of water wells shows that the ground instability is directly proportional to the groundwater depth. The second site is the Ocnele Mari brine extraction area. The exploitation of the Ocnele Mari salt deposit started from the Roman Empire time using the mining technology and from 1954 the salt dissolution technology which involves injecting water into the ground using a well and extracting the brine (water and salt) through another well. The extraction of salt through dissolution led to slow ground subsidence but the flooding and dissolution of the Roman caves led to catastrophic cave-ins and the relocation of an entire village. The water injection technique is still applied and the Roman cave system is an unknown, therefore further catastrophic events are expected. The existing theoretical simulations of the

  15. To the question on accuracy of forest heights’ measurements by the TanDEM-X radar interferometry data

    Directory of Open Access Journals (Sweden)

    T. N. Chimitdorzhiev

    2016-08-01

    Full Text Available The paper presents the validation results of the InSAR method for determining the forest canopy height, based on TanDEM-X and ALOS PALSAR data. The research conducted on the territory of the Baikal-Kudara forest area of the Republic of Buryatia (52°10'N, 106°48'E. Forest vegetation is represented mainly by conifers – pine, and spruce, with a small admixture of deciduous trees – aspen, birch, etc. The forest vegetation height was determined by subtracting the digital elevation model (DEM of the digital terrain model (DTM. DEM is built according to the L-band (wavelength of 23.5 cm ALOS PALSAR satellite with horizontal co-polarization mode. In the investigation it was assumed that a radar signal of ALOS PALSAR passes all forest thickness and reflected from the underlying surface, made it possible to recover terrain under forest canopy. DTM has been built using the TanDEM-X data (wavelength 3 cm. In this case, it was assumed that the radar echoes scattered from a some virtual phase centers of scattering surface, which characterizes the upper limit of the continuous forest canopy. To check the accuracy of satellite definitions of forest height in study area were made high-precision geodetic measurement of trees heights using electronic total station and the coordinates of geographic control points using differential GPS receivers. The discrepancy between the satellite and ground-based measurements at 11 test sites did not exceed 2 m, which is mainly due to the difference in measurement techniques: height of individual trees by ground methods and continuous forest canopy height using radar interferometry.

  16. Short non-coding RNAs as bacteria species identifiers detected by surface plasmon resonance enhanced common path interferometry

    Science.gov (United States)

    Greef, Charles; Petropavlovskikh, Viatcheslav; Nilsen, Oyvind; Khattatov, Boris; Plam, Mikhail; Gardner, Patrick; Hall, John

    2008-04-01

    Small non-coding RNA sequences have recently been discovered as unique identifiers of certain bacterial species, raising the possibility that they can be used as highly specific Biowarfare Agent detection markers in automated field deployable integrated detection systems. Because they are present in high abundance they could allow genomic based bacterial species identification without the need for pre-assay amplification. Further, a direct detection method would obviate the need for chemical labeling, enabling a rapid, efficient, high sensitivity mechanism for bacterial detection. Surface Plasmon Resonance enhanced Common Path Interferometry (SPR-CPI) is a potentially market disruptive, high sensitivity dual technology that allows real-time direct multiplex measurement of biomolecule interactions, including small molecules, nucleic acids, proteins, and microbes. SPR-CPI measures differences in phase shift of reflected S and P polarized light under Total Internal Reflection (TIR) conditions at a surface, caused by changes in refractive index induced by biomolecular interactions within the evanescent field at the TIR interface. The measurement is performed on a microarray of discrete 2-dimensional areas functionalized with biomolecule capture reagents, allowing simultaneous measurement of up to 100 separate analytes. The optical beam encompasses the entire microarray, allowing a solid state detector system with no scanning requirement. Output consists of simultaneous voltage measurements proportional to the phase differences resulting from the refractive index changes from each microarray feature, and is automatically processed and displayed graphically or delivered to a decision making algorithm, enabling a fully automatic detection system capable of rapid detection and quantification of small nucleic acids at extremely sensitive levels. Proof-of-concept experiments on model systems and cell culture samples have demonstrated utility of the system, and efforts are in

  17. 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

  18. 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,

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. Mach-Zehnder interferometry with interacting Bose-Einstein condensates in a double-well potential

    International Nuclear Information System (INIS)

    Berrada, T.

    2014-01-01

    Mach-Zehnder interferometry with interacting Bose-Einstein condensates in a double-well potential Particle-wave duality has enabled the construction of interferometers for massive particles such as electrons, neutrons, atoms or molecules. Implementing atom interferometry has required the development of analogues to the optical beam-splitters, phase shifters or recombiners to enable the coherent, i.e. phase-preserving manipulation of quantum superpositions. While initially demonstrating the wave nature of particles, atom interferometers have evolved into some of the most advanced devices for precision measurement, both for technological applications and tests of the fundamental laws of nature. Bose- Einstein condensates (BEC) of ultracold atoms are particular matter waves: they exhibit a collective many-body wave function and macroscopic coherence properties. As such, they have often been considered as an analogue to optical laser elds and it is natural to wonder whether BECs can provide to atom interferometry a similar boost as the laser brought to optical interferometry. One fundamental dierence between atomic BECs and lasers elds is the presence of atomic interactions, yielding an intrinsic non-linearity. On one hand, interactions can lead to eects destroying the phase coherence and limiting the interrogation time of trapped BEC interferometers. On the other hand, they can be used to generate nonclassical (e.g. squeezed) states to improve the sensitivity of interferometric measurements beyond the standard quantum limit (SQL). In this thesis, we present the realization of a full Mach-Zehnder interferometric sequence with trapped, interacting BECs con ned on an atom chip. Our interferometer relies on the coherent manipulation of a BEC in a magnetic double-well potential. For this purpose, we developed a novel type of matter-wave recombiner, an element which so far was missing in BEC atom optics. We have been able to exploit interactions to generate a squeezed

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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....

  10. 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.

  11. 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.

  12. Nonlinear control system for optical interferometry based on variable structure control and sliding modes.

    Science.gov (United States)

    Martin, Roberta I; Sakamoto, João M S; Teixeira, Marcelo C M; Martinez, Guilherme A; Pereira, Fernando C; Kitano, Cláudio

    2017-03-20

    This work presents a novel nonlinear control system designed for interferometry based on variable structure control and sliding modes. This approach can fully compensate the nonlinear behavior of the interferometer and lead to high accuracy control for large disturbances, featuring low cost, ease of implementation and high robustness, without a reset circuit (when compared with a linear control system). A deep stability analysis was accomplished and the global asymptotic stability of the system was proved. The results showed that the nonlinear control is able to keep the interferometer in the quadrature point and suppress signal fading for arbitrary signals, sinusoidal signals, or zero input signal, even under strong external disturbances. The system showed itself suitable to characterize a multi-axis piezoelectric flextentional actuator, which displacements that are much smaller than half wavelength. The high robustness allows the system to be embedded and to operate in harsh environments as factories, bringing the interferometry outside the laboratory.

  13. High-precision absolute distance measurement using dual-laser frequency scanned interferometry under realistic conditions

    International Nuclear Information System (INIS)

    Yang, H.-J.; Nyberg, Sven; Riles, Keith

    2007-01-01

    In this paper, we report on new high-precision absolute distance measurements performed with frequency scanned interferometry using a pair of single-mode optical fibers. Absolute distances were determined by counting the interference fringes produced while scanning the frequencies of the two chopped lasers. High-finesse Fabry-Perot interferometers were used to determine frequency changes during scanning. Dual lasers with oppositely scanning directions, combined with a multi-distance-measurement technique previously reported, were used to cancel drift errors and to suppress vibration effects and interference fringe uncertainties. Under realistic conditions, a precision about 0.2μm was achieved for a distance of 0.41m. With a precision that exceeds requirements, the frequency scanned interferometry is a promising high-precision optical alignment technique for International Linear Collider silicon tracker detector

  14. Phase extraction in dynamic speckle interferometry: proposal of a road map

    Directory of Open Access Journals (Sweden)

    Jacquot P.

    2010-06-01

    Full Text Available Of all the two-beam interference patterns, the ones obtained in speckle interferometry (SI are the most difficult to be phase-demodulated. Many solutions exist in classical smooth-wave interferometry and alike techniques, both in static and dynamic regimes. In SI, the three constituents of the signals – the background, the modulation and the phase – are all basically random variables. There is no way to make a prediction of the evolution of these variables outside the small size of the correlation volumes – the volumes defined by the average speckle grain. To some extent, the classical methods can be adapted to SI. Here, we prefer to develop a series of new processing tools tailored to the specificities of the dynamic SI signals: the cooperative use of the empirical mode decomposition (EMD, the Hilbert transform (HT, and the three dimensional piecewise processing (3DPP for recovering efficiently the phase of these signals.

  15. Digital Moiré based transient interferometry and its application in optical surface measurement

    Science.gov (United States)

    Hao, Qun; Tan, Yifeng; Wang, Shaopu; Hu, Yao

    2017-10-01

    Digital Moiré based transient interferometry (DMTI) is an effective non-contact testing methods for optical surfaces. In DMTI system, only one frame of real interferogram is experimentally captured for the transient measurement of the surface under test (SUT). When combined with partial compensation interferometry (PCI), DMTI is especially appropriate for the measurement of aspheres with large apertures, large asphericity or different surface parameters. Residual wavefront is allowed in PCI, so the same partial compensator can be applied to the detection of multiple SUTs. Excessive residual wavefront aberration results in spectrum aliasing, and the dynamic range of DMTI is limited. In order to solve this problem, a method based on wavelet transform is proposed to extract phase from the fringe pattern with spectrum aliasing. Results of simulation demonstrate the validity of this method. The dynamic range of Digital Moiré technology is effectively expanded, which makes DMTI prospective in surface figure error measurement for intelligent fabrication of aspheric surfaces.

  16. Operational Monitoring of Mines by COSMO-SkyMed PSP SAR Interferometry

    Science.gov (United States)

    Costantini, Mario; Malvarosa, Fabio; Miniati, Federico; de Assis, Luciano Mozer

    2016-08-01

    Synthetic aperture radar (SAR) interferometry is a powerful technology for detection and monitoring of slow ground surface movements. Monitoring of ground deformations in mining structures is an important application, particularly difficult because the scene changes with time. The persistent scatterer pair (PSP) approach, recently proposed to overcome some limitations of standard persistent scatter interferometry, proved to be effective also for mine monitoring. In this work, after resuming the main ideas of the PSP method, we describe the PSP measurements obtained from high- resolution X-band COSMO-SkyMed data over a large mining area in Minas Gerais state, Brazil. The outcomes demonstrate that dense and accurate ground deformation measurements can be obtained on the mining area and its structures (such as open pits, waste dumps, conveyor belts, water and tailings dams, etc.), achieving a consistent global view including also areas where field instruments are not installed.

  17. Multi-chord fiber-coupled interferometry of supersonic plasma jets (invited)

    International Nuclear Information System (INIS)

    Merritt, Elizabeth C.; Lynn, Alan G.; Gilmore, Mark A.; Thoma, Carsten; Loverich, John; Hsu, Scott C.

    2012-01-01

    A multi-chord fiber-coupled interferometer is being used to make time-resolved density measurements of supersonic argon plasma jets on the Plasma Liner Experiment. The long coherence length of the laser (>10 m) allows signal and reference path lengths to be mismatched by many meters without signal degradation, making for a greatly simplified optical layout. Measured interferometry phase shifts are consistent with a partially ionized plasma in which both positive and negative phase shift values are observed depending on the ionization fraction. In this case, both free electrons and bound electrons in ions and neutral atoms contribute to the index of refraction. This paper illustrates how the interferometry data, aided by numerical modeling, are used to derive total jet density, jet propagation velocity (∼15–50 km/s), jet length (∼20–100 cm), and 3D expansion.

  18. Application of SAR interferometry to low-rate crustal deformation fields

    Science.gov (United States)

    Vincent, Paul

    Differential SAR interferometry is applied to the study of low-rate interseismic crustal deformation fields along three regions of the San Adreas fault system: Salton Sea (southernmost region), Pinto Mountain fault (south-central region), and San Francisco Bay (northern region). New techniques are developed to analyze and model these low-rate deformation fields including constrained horizontal-vertical component deconvolution, deformation phase pattern analysis and strain field evolution modeling. Several new active faults were discovered as well as unmeasured activity on existing faults in the process of this SAR interferometry study. The feasibility and limitations of InSAR as a tool to study low-rate deformation fields is also addressed.

  19. Temperature measurement of an axisymmetric flame using phase shift holographic interferometry with fast Fourier transform

    Science.gov (United States)

    Tieng, S. M.; Lai, W. Z.

    Because of the importance of the temperature scalar measurements in combination diagonostics, application of phase shift holographic interferometry to temperature measurement of an axisymmetrically premixed flame was experimentally investigated. The test apparatus is an axisymmetric Bunsen burner. Propane of 99 percent purity is used as the gaseous fuel. A fast Fourier transform, a more efficient and accurate approach for Abel inversion, is used for reconstructed the axisymmetric temperature field from the interferometric data. The temperature distribution is compared with the thermocouple-measured values. The comparison shows that the proposed technique is satisfactory. The result errors are analyzed in detail. It is shown that this technique overcomes most of the earlier problems and limitations detrimental to the conventional holographic interferometry.

  20. Multi-boson effects in Bose-Einstein interferometry and the multiplicity distribution

    CERN Document Server

    Heinz, Ulrich W; Zhang, Q H; Heinz, Ulrich; Scotto, Pierre; Zhang, Qing-Hui

    2001-01-01

    Multi-boson symmetrization effects on two-particle Bose-Einstein interferometry are studied for ensembles with arbitrary multiplicity distributions. This generalizes the previously studied case of a Poissonian input multiplicity distribution. In the general case we find interesting residual correlations which require a modified framework for extracting information on the source geometry from two-particle correlation measurements. In sources with high phase-space densities, multi-boson effects modify the Hanbury Brown-Twiss (HBT) radius parameters and simultaneously generate strong residual correlations. We clarify their effect on the correlation strength (intercept parameter) and thus explain a variety of previously reported puzzling multi-boson symmetrization phenomena. Using a class of analytically solvable Gaussian source models, with and without space-momentum correlations, we present a comprehensive overview of multi-boson symmetrization effects on particle interferometry. For event ensembles of (approxi...

  1. Contribution of the Refractive Index Fluctuations to the Length Noise in Displacement Interferometry

    Czech Academy of Sciences Publication Activity Database

    Holá, Miroslava; Hrabina, Jan; Šarbort, Martin; Oulehla, Jindřich; Číp, Ondřej; Lazar, Josef

    2015-01-01

    Roč. 15, č. 5 (2015), s. 263-267 ISSN 1335-8871 R&D Projects: GA ČR GB14-36681G; GA TA ČR TA02010711; GA TA ČR TE01020233; GA MŠk(CZ) LO1212; GA MŠk EE2.3.30.0054 Institutional support: RVO:68081731 Keywords : nanometrology * interferometry * refractive index of air Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.969, year: 2015

  2. Tone-assisted time delay interferometry on GRACE Follow-On

    Science.gov (United States)

    Francis, Samuel P.; Shaddock, Daniel A.; Sutton, Andrew J.; de Vine, Glenn; Ware, Brent; Spero, Robert E.; Klipstein, William M.; McKenzie, Kirk

    2015-07-01

    We have demonstrated the viability of using the Laser Ranging Interferometer on the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) space mission to test key aspects of the interspacecraft interferometry proposed for detecting gravitational waves. The Laser Ranging Interferometer on GRACE-FO will be the first demonstration of interspacecraft interferometry. GRACE-FO shares many similarities with proposed space-based gravitational wave detectors based on the Laser Interferometer Space Antenna (LISA) concept. Given these similarities, GRACE-FO provides a unique opportunity to test novel interspacecraft interferometry techniques that a LISA-like mission will use. The LISA Experience from GRACE-FO Optical Payload (LEGOP) is a project developing tests of arm locking and time delay interferometry (TDI), two frequency stabilization techniques, that could be performed on GRACE-FO. In the proposed LEGOP TDI demonstration one GRACE-FO spacecraft will have a free-running laser while the laser on the other spacecraft will be locked to a cavity. It is proposed that two one-way interspacecraft phase measurements will be combined with an appropriate delay in order to produce a round-trip, dual one-way ranging (DOWR) measurement independent of the frequency noise of the free-running laser. This paper describes simulated and experimental tests of a tone-assisted TDI ranging (TDIR) technique that uses a least-squares fitting algorithm and fractional-delay interpolation to find and implement the delays needed to form the DOWR TDI combination. The simulation verifies tone-assisted TDIR works under GRACE-FO conditions. Using simulated GRACE-FO signals the tone-assisted TDIR algorithm estimates the time-varying interspacecraft range with a rms error of ±0.2 m , suppressing the free-running laser frequency noise by 8 orders of magnitude. The experimental results demonstrate the practicability of the technique, measuring the delay at the 6 ns level in the presence of a

  3. Potential of balloon payloads for in flight validation of direct and nulling interferometry concepts

    Science.gov (United States)

    Demangeon, Olivier; Ollivier, Marc; Le Duigou, Jean-Michel; Cassaing, Frédéric; Coudé du Foresto, Vincent; Mourard, Denis; Kern, Pierre; Lam Trong, Tien; Evrard, Jean; Absil, Olivier; Defrere, Denis; Lopez, Bruno

    2010-07-01

    While the question of low cost / low science precursors is raised to validate the concepts of direct and nulling interferometry space missions, balloon payloads offer a real opportunity thanks to their relatively low cost and reduced development plan. Taking into account the flight capabilities of various balloon types, we propose in this paper, several concepts of payloads associated to their flight plan. We also discuss the pros and cons of each concepts in terms of technological and science demonstration power.

  4. Know the Star, Know the Planet. 2. Speckle Interferometry of Exoplanet Host Stars

    Science.gov (United States)

    2011-11-01

    DVA ” is background subtracted through boxcar subtraction and the sharp central peak, which corresponds to the zeroth-order speckles correlating with...them- selves, is clipped. Companions in the resulting DVA are then readily apparent as peaks several sigma above the background. Of the 118 exoplanet...USNO with an ICCD and reduced with the DVA method. Asterisks (N = 11) are those observed by other interferometry groups, and an “X” (N = 292) are

  5. Suppression of Air Refractive Index Variations in High-Resolution Interferometry

    Czech Academy of Sciences Publication Activity Database

    Lazar, Josef; Číp, Ondřej; Čížek, Martin; Hrabina, Jan; Buchta, Zdeněk

    2011-01-01

    Roč. 11, č. 8 (2011), s. 7644-7655 ISSN 1424-8220 R&D Projects: GA ČR GA102/09/1276; GA ČR GPP102/11/P820; GA AV ČR KAN311610701; GA MŠk(CZ) LC06007 Institutional research plan: CEZ:AV0Z20650511 Keywords : refractometry * nanopositioning * interferometry * nanometrology Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.739, year: 2011

  6. The Convection of Close Red Supergiant Stars Observed With Near-Infrared Interferometry

    Science.gov (United States)

    Montargès, M.; Kervella, P.; Perrin, G.; Chiavassa, A.; Aurière, M.

    2015-12-01

    Our team has obtained observations of the photosphere of the two closest red supergiant stars Betelgeuse (α Ori) and Antares (α Sco) using near infrared interferometry. We have been monitoring the photosphere of Betelgeuse with the VLTI/PIONIER instrument for three years. On Antares, we obtained an unprecedented sampling of the visibility function. These data allow us to probe the convective photosphere of massive evolved stars.

  7. Detection techniques in low-coherence interferometry and their impact on overall measurement accuracy

    Czech Academy of Sciences Publication Activity Database

    Pikálek, Tomáš; Fořt, Tomáš; Buchta, Zdeněk

    2014-01-01

    Roč. 53, č. 36 (2014), s. 8463-8470 ISSN 1559-128X R&D Projects: GA ČR GB14-36681G; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : interferometry * fringe analysis * surface measurements, figure * optical data processing Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.784, year: 2014

  8. Recovery of the Earth's Gravity Field Based on Spaceborne Atom-interferometry and Its Accuracy Estimation

    Directory of Open Access Journals (Sweden)

    ZHU Zhu

    2017-09-01

    Full Text Available The electrostatic gravity gradiometer has been successfully applied as a core sensor in satellite gravity gradiometric mission GOCE, and its observations are used to recover the Earth's static gravity field with a degree and order above 200. The lifetime of GOCE has been over, and the next generation satellite gravity gradiometry with higher resolution is urgently required in order to recover the global steady-state gravity field with a degree and order of 200~360. High potential precision can be obtained in space by atom-interferometry gravity gradiometer due to its long interference time, and thus the atom-interferometry-based satellite gravity gradiometry has been proposed as one of the candidate techniques for the next satellite gravity gradiometric mission. In order to achieve the science goal for high resolution gravity field measurement in the future, a feasible scheme of atom-interferometry gravity gradiometry in micro-gravity environment is given in this paper, and the gravity gradient measurement can be achieved with a noise of 0.85mE/Hz1/2. Comparison and estimation of the Earth's gravity field recovery precision for different types of satellite gravity gradiometry is discussed, and the results show that the satellite gravity gradiometry based on atom-interferometry is expected to provide the global gravity field model with an improved accuracy of 7~8cm in terms of geoid height and 3×10-5 m/s2 in terms of gravity anomaly respectively at a degree and order of 252~290.

  9. Single particle measurements and two particle interferometry results from CERN experiment NA44

    International Nuclear Information System (INIS)

    Simon-Gillo, J.

    1994-01-01

    CERN experiment NA44 is optimized for the study of identified single and multiple particle distributions to p T = 0 near mid-rapidity. We measure π +- , K +- , p, bar p, d and bar d, in p + A and A + A collisions at 450 and 20OGeV/u, respectively. Two-particle intensity interferometry results from π + π + , K + K + , and K - K - measurements and single particle distributions are presented

  10. Finite-time Stückelberg interferometry with nanomechanical modes

    Science.gov (United States)

    Seitner, Maximilian J.; Ribeiro, Hugo; Kölbl, Johannes; Faust, Thomas; Weig, Eva M.

    2017-03-01

    Stückelberg interferometry describes the interference of two strongly coupled modes during a double passage through an avoided energy level crossing. In this work, we investigate finite-time effects in Stückelberg interferometry and discuss the exact analytical solution of the double passage Stückelberg problem by expanding the finite-time solution of the Landau-Zener problem. Approximating the return probability amplitudes of the double passage in distinct limits reveals uncharted parameter regimes of Stückelberg interferometry where finite-time effects affect the coherent exchange of energy. We find the long-time limit of the exact solution to formally coincide with the well-established adiabatic impulse model which is, to the best of our knowledge, the only regime of Stückelberg interferometry reported so far. Experimentally, we study all predicted regimes using a purely classical, strongly coupled nanomechanical two-mode system of high quality factor. The classical two-mode system consists of the in-plane and out-of-plane fundamental flexural mode of a high stress silicon nitride string resonator, coupled via electric gradient fields. We exploit our experimental and theoretical findings by studying the onset of Stückelberg interference in dependence of the characteristic system control parameters and obtain characteristic excitation oscillations between the two modes even without the explicit need of traversing the avoided crossing. The presented findings are not limited to classical mechanical two-mode systems but can be applied to every strongly coupled (quantum) two-level system, for example a spin-1/2 system or superconducting qubit.

  11. The radius and mass of the close solar twin 18 Scorpii derived from asteroseismology and interferometry

    DEFF Research Database (Denmark)

    Bazot, M.; Ireland, M.J.; Huber, D.

    2011-01-01

    Sco. We observed the star during 12 nights with HARPS for seismology and used the PAVO beam-combiner at CHARA for interferometry. An average large frequency separation 134.4 ± 0.3 μHz and angular and linear radiuses of 0.6759 ± 0.0062 mas and 1.010 ± 0.009 Rsun were estimated. We used these values...

  12. Application Of Holographic Interferometry For Investigation Of Microroughness Of Engineering Surfaces

    Science.gov (United States)

    Lech, Marek; Mruk, Irena; Stupnicki, Jacek

    1985-01-01

    The paper describes an improved immersion method of holographic interferometry /IMHI/ adjusted for studies of roughness of engineering surfaces. Special optical arrangement, with two types of immersion cells and adequate technique of preparing transparent replicas reproducting with high fidelity details of differently machined surfaces was elaborated. It permits to obtain the contour maps of the surface asperities with intervals between the planes of succesive contour lines within a range of 1 μm. The results obtained for some engineering surfaces are given.

  13. Holographic interferometry - a nondestructive inspection technique for early detection of construction element damages

    International Nuclear Information System (INIS)

    Wachutka, H.; Fritzsch, W.; Gruenewald, K.

    1977-01-01

    After a short introduction into the fundamentals of holographic interferometry, the application of this process to non-destructive material testing is explained. Practical examples of qualitative and quantitative deformation measurements carried out on building elements of different materials as well as on metallic and nonmetallic combinations show the possibilities of early recognition of manufacturing flaws and weak points due to the construction and also the determination of construction material characteristic coefficients. (orig.) [de

  14. Many-body interferometry of magnetic polaron dynamics

    Science.gov (United States)

    Ashida, Yuto; Schmidt, Richard; Tarruell, Leticia; Demler, Eugene

    2018-02-01

    The physics of quantum impurities coupled to a many-body environment is among the most important paradigms of condensed-matter physics. In particular, the formation of polarons, quasiparticles dressed by the polarization cloud, is key to the understanding of transport, optical response, and induced interactions in a variety of materials. Despite recent remarkable developments in ultracold atoms and solid-state materials, the direct measurement of their ultimate building block, the polaron cloud, has remained a fundamental challenge. We propose and analyze a platform to probe time-resolved dynamics of polaron-cloud formation with an interferometric protocol. We consider an impurity atom immersed in a two-component Bose-Einstein condensate where the impurity generates spin-wave excitations that can be directly measured by the Ramsey interference of surrounding atoms. The dressing by spin waves leads to the formation of magnetic polarons and reveals a unique interplay between few- and many-body physics that is signified by single- and multi-frequency oscillatory dynamics corresponding to the formation of many-body bound states. Finally, we discuss concrete experimental implementations in ultracold atoms.

  15. Utilization of InSAR differential interferometry for surface deformation detection caused by mining

    Energy Technology Data Exchange (ETDEWEB)

    Yang, F. [Liaoning Technical Univ., Fuxin (China). School of Geomatics; Shao, Y. [Liaoning Technical Univ., Fuxin (China). Dept. of Foreign Language; Guichen, M. [Gifu Univ., Yanagido, Gifu (Japan). Dept. of Civil Engineering

    2010-07-01

    In China, the surface deformation of ground has been a significant geotechnical problem as a result of cracks in the ground surface, collapsing of house, and subsidence of roads. A powerful technology for detecting surface deformation in the ground is differential interferometry using synthetic aperture radar (INSAR). The technology enables the analysis from different phase of micro-wave between two observed data by synthetic aperture radar (SAR) of surface deformation of ground such as ground subsidence, land slide, and slope failure. In January 2006, the advanced land observing satellite was launched by the Japan Aerospace Exploration Agency. This paper presented an analytical investigation to detect ground subsidence or change caused by mining, overuse of ground water, and disaster. Specifically, the paper discussed the INSAR monitoring technology of the mine slope, including INSAR data sources and processing software; the principle of synthetic aperture radar interferometry; principles of differential SAR interferometry; and INSAR technology to slope monitoring of the Haizhou open pit mine. The paper also discussed the Haizhou strip mine side slope INSAR monitoring results and tests. It was concluded that the use of synthetic aperture radar interferometer technique was the optimal technique to provide three-dimensional spatial information and minimal change from ground surface by spatial remote sensing device. 18 refs., 5 figs.

  16. Azimuthally Sensitive Hanbury Brown–Twiss Interferometry measured with the ALICE Experiment

    CERN Document Server

    Gramling, Johanna

    Bose–Einstein correlations of identical pions emitted in high-energy particle collisions provide information about the size of the source region in space-time. If analyzed via HBT Interferometry in several directions with respect to the reaction plane, the shape of the source can be extracted. Hence, HBT Interferometry provides an excellent tool to probe the characteristics of the quark-gluon plasma possibly created in high-energy heavy-ion collisions. This thesis introduces the main theoretical concepts of particle physics, the quark-gluon plasma and the technique of HBT interferometry. The ALICE experiment at the CERN Large Hadron Collider (LHC) is explained and the first azimuthally integrated results measured in Pb–Pb collisions at sqrt(s_NN) = 2.76TeV with ALICE are presented. A detailed two-track resolution study leading to a global pair cut for HBT analyses has been performed, and a framework for the event plane determination has been developed. The results from azimuthally sensitive HBT interferom...

  17. The application of satellite differential SAR interferometry-derived ground displacements in hydrogeology

    Science.gov (United States)

    Galloway, D.L.; Hoffmann, J.

    2007-01-01

    The application of satellite differential synthetic aperture radar (SAR) interferometry, principally coherent (InSAR) and to a lesser extent, persistent-scatterer (PSI) techniques to hydrogeologic studies has improved capabilities to map, monitor, analyze, and simulate groundwater flow, aquifer-system compaction and land subsidence. A number of investigations over the previous decade show how the spatially detailed images of ground displacements measured with InSAR have advanced hydrogeologic understanding, especially when a time series of images is used in conjunction with histories of changes in water levels and management practices. Important advances include: (1) identifying structural or lithostratigraphic boundaries (e.g. faults or transitional facies) of groundwater flow and deformation; (2) defining the material and hydraulic heterogeneity of deforming aquifer-systems; (3) estimating system properties (e.g. storage coefficients and hydraulic conductivities); and (4) constraining numerical models of groundwater flow, aquifer-system compaction, and land subsidence. As a component of an integrated approach to hydrogeologic monitoring and characterization of unconsolidated alluvial groundwater basins differential SAR interferometry contributes unique information that can facilitate improved management of groundwater resources. Future satellite SAR missions specifically designed for differential interferometry will enhance these contributions. ?? Springer-Verlag 2006.

  18. X-ray phase radiography and tomography with grating interferometry and the reverse projection technique

    International Nuclear Information System (INIS)

    Wang, Zhili; Gao, Kun; Ge, Xin; Wu, Zhao; Chen, Heng; Wang, Shenghao; Wu, Ziyu; Zhu, Peiping; Yuan, Qingxi; Huang, Wanxia; Zhang, Kai

    2013-01-01

    X-ray grating interferometry provides substantially increased contrast over conventional absorption-based imaging methods, and therefore new and complementary information. Compared with other phase-contrast imaging techniques, x-ray grating interferometry can overcome some of the problems that have impaired the applications of x-ray phase-contrast radiography and phase tomography. Recently, special attention has been paid to the development of quantitative phase retrieval methods, which is mandatory to perform x-ray phase tomography, to achieve material identification, to differentiate distinct tissues, etc. Typically, the phase-stepping approach has been utilized for phase retrieval in grating interferometry. This method requires a grating scanning and acquisition of multiple radiographic projections, and therefore is disadvantageous in terms of imaging speed and radiation damage. Here we present an innovative, highly sensitive approach, dubbed ‘reverse projection’ (RP), for quantitative phase retrieval. Compared with the phase-stepping approach, the present RP method abandons grating scanning completely, and thus is advantageous due to its much higher efficiency and the reduced radiation dose, without the degradation of reconstruction quality. This review presents a detailed explanation of the principle of the RP method. Both radiography and phase tomography experiments are performed to validate the RP method. We believe that this new technique will find widespread applications in biomedical imaging and in vivo studies. (paper)

  19. A portable magneto-optical trap with prospects for atom interferometry in civil engineering.

    Science.gov (United States)

    Hinton, A; Perea-Ortiz, M; Winch, J; Briggs, J; Freer, S; Moustoukas, D; Powell-Gill, S; Squire, C; Lamb, A; Rammeloo, C; Stray, B; Voulazeris, G; Zhu, L; Kaushik, A; Lien, Y-H; Niggebaum, A; Rodgers, A; Stabrawa, A; Boddice, D; Plant, S R; Tuckwell, G W; Bongs, K; Metje, N; Holynski, M

    2017-08-06

    The high precision and scalable technology offered by atom interferometry has the opportunity to profoundly affect gravity surveys, enabling the detection of features of either smaller size or greater depth. While such systems are already starting to enter into the commercial market, significant reductions are required in order to reach the size, weight and power of conventional devices. In this article, the potential for atom interferometry based gravimetry is assessed, suggesting that the key opportunity resides within the development of gravity gradiometry sensors to enable drastic improvements in measurement time. To push forward in realizing more compact systems, techniques have been pursued to realize a highly portable magneto-optical trap system, which represents the core package of an atom interferometry system. This can create clouds of 10 7 atoms within a system package of 20 l and 10 kg, consuming 80 W of power.This article is part of the themed issue 'Quantum technology for the 21st century'. © 2017 The Author(s).

  20. Analysis of the performance of interferometry, surface plasmon resonance and luminescence as biosensors and chemosensors

    International Nuclear Information System (INIS)

    Ince, R.; Narayanaswamy, R.

    2006-01-01

    Sensitivity, dynamic range and resolution have been calculated and compared from a range of analytes sensed in the literature using the techniques of interferometry, surface plasmon resonance (SPR) and luminescence. A detailed explanation of the physical and chemical/biological properties required of optical sensors is included along with the principle of operation of the sensors. Theoretical sensitivities of interferometry and SPR are also detailed along with parameters affecting these sensitivities. In the literature discussed in this review paper, the technique of luminescence, which relies intrinsically on 'labelling', offers the best resolutions for sensing of biomolecules (protein and DNA). Interference techniques offer the best resolutions for low molecular weight chemical liquids/vapours. Techniques which are 'label-free' are often desirable and it is demonstrated here that by combining the techniques of SPR with interferometry, it is possible to sense proteins with a resolution similar to that of luminescence. The future of chemo- and bio-sensing is discussed in terms of potential for multi-channel analysis, their continuous miniaturisation and their impending nanotechnology revolution

  1. Development of a Hybrid Atomic Force Microscopic Measurement System Combined with White Light Scanning Interferometry

    Directory of Open Access Journals (Sweden)

    Xiaotang Hu

    2011-12-01

    Full Text Available A hybrid atomic force microscopic (AFM measurement system combined with white light scanning interferometry for micro/nanometer dimensional measurement is developed. The system is based on a high precision large-range positioning platform with nanometer accuracy on which a white light scanning interferometric module and an AFM head are built. A compact AFM head is developed using a self-sensing tuning fork probe. The head need no external optical sensors to detect the deflection of the cantilever, which saves room on the head, and it can be directly fixed under an optical microscopic interferometric system. To enhance the system’s dynamic response, the frequency modulation (FM mode is adopted for the AFM head. The measuring data can be traceable through three laser interferometers in the system. The lateral scanning range can reach 25 mm × 25 mm by using a large-range positioning platform. A hybrid method combining AFM and white light scanning interferometry is proposed to improve the AFM measurement efficiency. In this method, the sample is measured firstly by white light scanning interferometry to get an overall coarse morphology, and then, further measured with higher resolution by AFM. Several measuring experiments on standard samples demonstrate the system’s good measurement performance and feasibility of the hybrid measurement method.

  2. Partial compensation interferometry for measurement of surface parameter error of high-order aspheric surfaces

    Science.gov (United States)

    Hao, Qun; Li, Tengfei; Hu, Yao

    2018-01-01

    Surface parameters are the properties to describe the shape characters of aspheric surface, which mainly include vertex radius of curvature (VROC) and conic constant (CC). The VROC affects the basic properties, such as focal length of an aspheric surface, while the CC is the basis of classification for aspheric surface. The deviations of the two parameters are defined as surface parameter error (SPE). Precisely measuring SPE is critical for manufacturing and aligning aspheric surface. Generally, SPE of aspheric surface is measured directly by curvature fitting on the absolute profile measurement data from contact or non-contact testing. And most interferometry-based methods adopt null compensators or null computer-generated holograms to measure SPE. To our knowledge, there is no effective way to measure SPE of highorder aspheric surface with non-null interferometry. In this paper, based on the theory of slope asphericity and the best compensation distance (BCD) established in our previous work, we propose a SPE measurement method for high-order aspheric surface in partial compensation interferometry (PCI) system. In the procedure, firstly, we establish the system of two element equations by utilizing the SPE-caused BCD change and surface shape change. Then, we can simultaneously obtain the VROC error and CC error in PCI system by solving the equations. Simulations are made to verify the method, and the results show a high relative accuracy.

  3. Surface resistivity/conductivity of oxide–hydroxide compounds in inhibited seawater by optical interferometry

    Directory of Open Access Journals (Sweden)

    Khaled Habib

    2016-09-01

    Full Text Available Optical interferometry techniques were used to measure the surface resistivity/conductivity of carbon steel samples in blank seawater and in seawater with different concentrations of a corrosion inhibitor, without any physical contact. The measurement of the surface resistivity/conductivity of carbon steel samples was carried out in blank seawater and in seawater with a concentration range of 5–20 ppm of RA-41 corrosion inhibitor, at room temperature. In this investigation, the real-time holographic interferometry was carried out to measure the thickness of anodic dissolved layer or the total thickness, Utotal, of the formed oxide layer of carbon steel samples during the alternating current (AC impedance of the samples in blank seawater and in 5–20 ppm RA-41 inhibited seawater, respectively. In other words, the surface resistivity/conductivity of carbon steel samples was determined simultaneously by holographic interferometry, an electromagnetic method, and by the Electrochemical Impedance (E.I spectroscopy, an electronic method. In addition, a mathematical model was derived in order to correlate between the AC impedance (resistance and to the surface (orthogonal displacement of the surface of the samples in solutions.

  4. Dynamic Deformation of ETNA Volcano Observed by GPS and SAR Interferometry

    Science.gov (United States)

    Lundgren, P.; Rosen, P.; Webb, F.; Tesauro, M.; Lanari, R.; Sansosi, E.; Puglisi, G.; Bonforte, A.; Coltelli, M.

    1999-01-01

    Synthetic aperture radar (SAR) interferometry and GPS have shown that during the quiescent period from 1993-1995 Mt. Etna volcano, Italy, inflated. Since the initiation of eruptive activity since late 1995 the deformation has been more contentious. We will explore the detailed deformation during the period from 1995-1996 spanning the late stages of inflation and the beginning of eruptive activity. We use SAR interferometry and GPS data to measure the volcano deformation. We invert the observed deformation for both simple point source. le crack elastic sources or if warranted for a spheroidal pressure So In particular, we will examine the evolution of the inflation and the transition to a lesser deflation observed at the end of 1995. We use ERS-1/2 SAR data from both ascending and descending passes to allow for dense temporal 'sampling of the deformation and to allow us to critically assess atmospheric noise. Preliminary results from interferometry suggest that the inflation rate accelerated prior to resumption of activity in 1995, while GPS data suggest a more steady inflation with some fluctuation following the start of activity. This study will compare and contrast the interferometric SAR and GPS results and will address the strengths and weaknesses of each technique towards volcano deformation studies.

  5. Development of Phase Detection Schemes Based on Surface Plasmon Resonance Using Interferometry

    Directory of Open Access Journals (Sweden)

    Muhammad Kashif

    2014-08-01

    Full Text Available Surface plasmon resonance (SPR is a novel optical sensing technique with a unique ability to monitor molecular binding in real-time for biological and chemical sensor applications. Interferometry is an excellent tool for accurate measurement of SPR changes, the measurement and comparison is made for the sensitivity, dynamic range and resolution of the different analytes using interferometry techniques. SPR interferometry can also employ phase detection in addition to the amplitude of the reflected light wave, and the phase changes more rapidly compared with other approaches, i.e., intensity, angle and wavelength. Therefore, the SPR phase interferometer offers the advantages of spatial phase resolution and high sensitivity. This work discusses the advancements in interferometric SPR methods to measure the phase shifts due to refractive index changes. The main application areas of SPR sensors are demonstrated, i.e., the Fabry-Perot interferometer, Michelson interferometer and Mach-Zehnder interferometer, with different configurations. The three interferometers are discussed in detail, and solutions are suggested to enhance the performance parameters that will aid in future biological and chemical sensors.

  6. Physically-Based Interactive Flow Visualization Based on Schlieren and Interferometry Experimental Techniques

    KAUST Repository

    Brownlee, C.

    2011-11-01

    Understanding fluid flow is a difficult problem and of increasing importance as computational fluid dynamics (CFD) produces an abundance of simulation data. Experimental flow analysis has employed techniques such as shadowgraph, interferometry, and schlieren imaging for centuries, which allow empirical observation of inhomogeneous flows. Shadowgraphs provide an intuitive way of looking at small changes in flow dynamics through caustic effects while schlieren cutoffs introduce an intensity gradation for observing large scale directional changes in the flow. Interferometry tracks changes in phase-shift resulting in bands appearing. The combination of these shading effects provides an informative global analysis of overall fluid flow. Computational solutions for these methods have proven too complex until recently due to the fundamental physical interaction of light refracting through the flow field. In this paper, we introduce a novel method to simulate the refraction of light to generate synthetic shadowgraph, schlieren and interferometry images of time-varying scalar fields derived from computational fluid dynamics data. Our method computes physically accurate schlieren and shadowgraph images at interactive rates by utilizing a combination of GPGPU programming, acceleration methods, and data-dependent probabilistic schlieren cutoffs. Applications of our method to multifield data and custom application-dependent color filter creation are explored. Results comparing this method to previous schlieren approximations are finally presented. © 2011 IEEE.

  7. 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

  8. 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.

  9. 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

  10. A birefringent polarization modulator: Application to phase measurement in conoscopic interference patterns

    Science.gov (United States)

    Veiras, F. E.; Garea, M. T.; Perez, L. I.

    2016-04-01

    Conoscopic interferometry for crystal characterization is a very well-known technique with increasing applications in different fields of technology. The advantage of the scheme proposed here is the introduction of a polarization modulator that allows the recovery of the phase information contained in conoscopic interferograms. This represents a real advantage since the most relevant physical information of the sample under study is usually contained in the phase of the fringe pattern. Moreover, this technique works successfully even when there are no visible fringes. The setup employed is a simple conoscopic interferometer where the elements under study correspond to two birefringent crystal slabs and a commercial mica wave plate. It allows the crystals to be characterized and the wave plate retardance to be measured as a function of the angle of incidence. The modulator itself consists of a single tiltable crystal plate which, by means of phase shifting techniques, permits the recovery of a phase map for each sample. It is inexpensive and it can be easily calibrated, so it works with a wide range of phase shifting interferometry algorithms. We show that our scheme is easily adaptable to algorithms that require either a low or high amount of interferograms.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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...

  16. 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

  17. 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

  18. Direct Evidence of Conformational Changes Associated with Voltage Gating in a Voltage Sensor Protein by Time-Resolved X-ray/Neutron Interferometry

    Science.gov (United States)

    2015-01-01

    The voltage sensor domain (VSD) of voltage-gated cation (e.g., Na+, K+) channels central to neurological signal transmission can function as a distinct module. When linked to an otherwise voltage-insensitive, ion-selective membrane pore, the VSD imparts voltage sensitivity to the channel. Proteins homologous with the VSD have recently been found to function themselves as voltage-gated proton channels or to impart voltage sensitivity to enzymes. Determining the conformational changes associated with voltage gating in the VSD itself in the absence of a pore domain thereby gains importance. We report the direct measurement of changes in the scattering-length density (SLD) profile of the VSD protein, vectorially oriented within a reconstituted phospholipid bilayer membrane, as a function of the transmembrane electric potential by time-resolved X-ray and neutron interferometry. The changes in the experimental SLD profiles for both polarizing and depolarizing potentials with respect to zero potential were found to extend over the entire length of the isolated VSD’s profile structure. The characteristics of the changes observed were in qualitative agreement with molecular dynamics simulations of a related membrane system, suggesting an initial interpretation of these changes in terms of the VSD’s atomic-level 3-D structure. PMID:24697545

  19. Comparison of Enzyme-Linked Immunosorbent Assay, Surface Plasmon Resonance and Biolayer Interferometry for Screening of Deoxynivalenol in Wheat and Wheat Dust

    Directory of Open Access Journals (Sweden)

    Melanie Sanders

    2016-04-01

    Full Text Available A sample preparation method was developed for the screening of deoxynivalenol (DON in wheat and wheat dust. Extraction was carried out with water and was successful due to the polar character of DON. For detection, an enzyme-linked immunosorbent assay (ELISA was compared to the sensor-based techniques of surface plasmon resonance (SPR and biolayer interferometry (BLI in terms of sensitivity, affinity and matrix effect. The matrix effects from wheat and wheat dust using SPR were too high to further use this screenings method. The preferred ELISA and BLI methods were validated according to the criteria established in Commission Regulation 519/2014/EC and Commission Decision 2002/657/EC. A small survey was executed on 16 wheat lots and their corresponding dust samples using the validated ELISA method. A linear correlation (r = 0.889 was found for the DON concentration in dust versus the DON concentration in wheat (LOD wheat: 233 μg/kg, LOD wheat dust: 458 μg/kg.

  20. Horizontal and vertical crustal movements from three-dimensional very long baseline interferometry kinematic reference frame: Implication for the reversal timescale revision

    Science.gov (United States)

    Heki, Kosuke

    Three-dimensional kinematic reference frame of geodetic very long baseline interferometry (VLBI) stations, tied to a geologic plate motion model, was established using the GLB907 solution by first selecting globally distributed stable plate interior stations and then applying a small translation and a rotation for the entire network in a three-dimensional space so that the differences in the ``horizontal'' velocities between the VLBI observations and the model predictions are minimized. Since the VLBI network is global, we only assume that the horizontal movements of tectonically stable stations obey a plate motion model; we need not introduce any unwarranted constraints to the vertical velocities of specific stations to realize the frame. A suggestive correlation was found between the estimated vertical velocities of North American stations and those predicted by a postglacial rebound model. The revision of the magnetic polarity timescale (MPTS) causes a uniform increase or decrease of the predicted velocities, which could be detected as the small difference between the measured and the predicted relative plate velocities. Direct estimation of the correction suggests that the VLBI data fit best to the model when the NUVEL1 model is corrected by +3.4% (+/-1.2%), which differs significantly from the -4.5% deduced from the astronomical MPTS calibration. This was further confirmed by estimating the rotation rates for individual plate pairs.