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Polarimetry

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https://www.readbyqxmd.com/read/27910694/mhd-marking-using-the-mse-polarimeter-optics-in-ilw-jet-plasmas
#1
S Reyes Cortes, B Alper, D Alves, M Baruzzo, J Bernardo, P Buratti, R Coelho, C Challis, I Chapman, N Hawkes, T C Hender, J Hobirk, E Joffrin
In this communication we propose a novel diagnostic technique, which uses the collection optics of the JET Motional Stark Effect (MSE) diagnostic, to perform polarimetry marking of observed MHD in high temperature plasma regimes. To introduce the technique, first we will present measurements of the coherence between MSE polarimeter, electron cyclotron emission, and Mirnov coil signals aiming to show the feasibility of the method. The next step consists of measuring the amplitude fluctuation of the raw MSE polarimeter signals, for each MSE channel, following carefully the MHD frequency on Mirnov coil data spectrograms...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910623/an-upgraded-interferometer-polarimeter-system-for-broadband-fluctuation-measurements
#2
E Parke, W X Ding, J Duff, D L Brower
Measuring high-frequency fluctuations (above tearing mode frequencies) is important for diagnosing instabilities and transport phenomena. The Madison Symmetric Torus interferometer-polarimeter system has been upgraded to utilize improved planar-diode mixer technology. The new mixers reduce phase noise and allow more sensitive measurements of fluctuations at high frequency. Typical polarimeter rms phase noise values of 0.05°-0.07° are obtained with 400 kHz bandwidth. The low phase noise enables the resolution of fluctuations up to 250 kHz for polarimetry and 600 kHz for interferometry...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910420/high-sensitivity-far-infrared-laser-diagnostics-for-the-c-2u-advanced-beam-driven-field-reversed-configuration-plasmas
#3
B H Deng, M Beall, J Schroeder, G Settles, P Feng, J S Kinley, H Gota, M C Thompson
A high sensitivity multi-channel far infrared laser diagnostics with switchable interferometry and polarimetry operation modes for the advanced neutral beam-driven C-2U field-reversed configuration (FRC) plasmas is described. The interferometer achieved superior resolution of 1 × 10(16) m(-2) at >1.5 MHz bandwidth, illustrated by measurement of small amplitude high frequency fluctuations. The polarimetry achieved 0.04° instrument resolution and 0.1° actual resolution in the challenging high density gradient environment with >0...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910416/a-new-beam-emission-polarimetry-diagnostic-for-measuring-the-magnetic-field-line-angle-at-the-plasma-edge-of-asdex-upgrade
#4
E Viezzer, R Dux, M G Dunne
A new edge beam emission polarimetry diagnostic dedicated to the measurement of the magnetic field line angle has been installed on the ASDEX Upgrade tokamak. The new diagnostic relies on the motional Stark effect and is based on the simultaneous measurement of the polarization direction of the linearly polarized π (parallel to the electric field) and σ (perpendicular to the electric field) lines of the Balmer line Dα. The technical properties of the system are described. The calibration procedures are discussed and first measurements are presented...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910371/diagnostic-suite-of-the-c-2u-advanced-beam-driven-field-reversed-configuration-plasma-experiment
#5
M C Thompson, H Gota, S Putvinski, M Tuszewski, M Binderbauer
The C-2U experiment at Tri Alpha Energy studies the evolution of field-reversed configuration (FRC) plasmas sustained by neutral beam injection. Data on the FRC plasma performance are provided by a comprehensive suite of diagnostics that includes magnetic sensors, interferometry, Thomson scattering, spectroscopy, bolometry, reflectometry, neutral particle analyzers, and fusion product detectors. While many of these diagnostic systems were inherited from the preceding experiment C-2, C-2U has a variety of new and upgraded diagnostic systems: multi-chord far-infrared polarimetry, multiple fast imaging cameras with selectable atomic line filters, proton detector arrays, and 100 channel bolometer units capable of observing multiple regions of the spectrum simultaneously...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910338/a-streak-camera-based-fiber-optic-pulsed-polarimetry-technique-for-magnetic-sensing-to-sub-mm-resolution
#6
R J Smith, T E Weber
The technique of fiber optic pulsed polarimetry, which provides a distributed (local) measurement of the magnetic field along an optical fiber, has been improved to the point where, for the first time, photocathode based optical detection of backscatter is possible with sub-mm spatial resolutions. This has been realized through the writing of an array of deterministic fiber Bragg gratings along the fiber, a so-called backscatter-tailored optical fiber, producing a 34 000-fold increase in backscatter levels over Rayleigh...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27857375/radiation-correction-method-for-infrared-polarization-imaging-system-with-front-mounted-polarizer
#7
Shuo Li, Weiqi Jin, Runqiu Xia, Li Li, Xia Wang
The architecture of imaging polarimeters with front-mounted polarizer generally used in infrared imaging polarimetry has significant influence on the imaging process of the systems and further calculation of the polarization information of the observed scenario. In this study, the imaging process of infrared polarization imaging system with front-mounted polarizer is analyzed, a radiation correction method based on the modified infrared imaging model of such a system is proposed, and both laboratory and outdoor experiments are performed to verify its effect...
November 14, 2016: Optics Express
https://www.readbyqxmd.com/read/27857282/measurement-of-microfibril-angles-in-bamboo-using-mueller-matrix-imaging
#8
Sayyad Mannan, Mohammad Zaffar, Asima Pradhan, Sumit Basu
The microfibril angle (MFA) giving the orientation of cellulose chains in hard sclerenchymatous bamboo fibers is one of the most important parameters determining the overall strength of the bamboo culm. In this work, Mueller matrix imaging polarimetry is implemented for determining MFA measured over a transverse section of group of fibers and parenchyma cells in bamboo of Dendrocalamus strictus species. The method, based on the Stokes-Mueller formalism, decouples the birefringence exhibited by crystalline cellulose from the clumped polarization parameters using 16 images taken with different polarization states at subcellular resolution...
November 10, 2016: Applied Optics
https://www.readbyqxmd.com/read/27853775/molecular-frame-photoemission-by-a-comb-of-elliptical-high-order-harmonics-a-sensitive-probe-of-both-photodynamics-and-harmonic-complete-polarization-state
#9
K Veyrinas, V Gruson, S J Weber, L Barreau, T Ruchon, J-F Hergott, J-C Houver, R R Lucchese, P Salières, D Dowek
Due to the intimate anisotropic interaction between an XUV light field and a molecule resulting in photoionization (PI), molecular frame photoelectron angular distributions (MFPADs) are most sensitive probes of both electronic/nuclear dynamics and the polarization state of the ionizing light field. Consequently, they encode the complex dipole matrix elements describing the dynamics of the PI transition, as well as the three normalized Stokes parameters s1, s2, s3 characterizing the complete polarization state of the light, operating as molecular polarimetry...
November 17, 2016: Faraday Discussions
https://www.readbyqxmd.com/read/27828381/star-test-image-sampling-polarimeter
#10
Brandon G Zimmerman, Thomas G Brown
We present an analysis and test of an image sampling polarimeter based on the concept of Star Test Polarimetry first introduced by Ramkhalawon. The method makes use of a stress engineered optical element (SEO) placed in the pupil plane of an optical system to induce a polarization dependent point spread function (PSF) at the detector. We describe the calibration requirements of the polarimeter and introduce a new algorithm that can robustly extract the Stokes parameters in a single irradiance measurement. By acquiring statistics on the sampled Stokes parameters of a uniformly illuminated pinhole array, we show that a single frame can provide a root mean square angular error of approximately 10 milliradians on the Poincaré sphere...
October 3, 2016: Optics Express
https://www.readbyqxmd.com/read/27802694/implementation-of-a-new-cryopad-on-the-diffractometer-poli-at-mlz
#11
V Hutanu, W Luberstetter, E Bourgeat-Lami, M Meven, A Sazonov, A Steffen, G Heger, G Roth, E Lelièvre-Berna
A new polarized neutron single crystal diffractometer POLI (Polarization Investigator) has been developed at the Maier-Leibnitz Zentrum, Garching, Germany. After reviewing existing devices, spherical neutron polarimetry has been implemented on POLI as a main experimental technique using a third-generation cryogenic polarization analysis device (Cryopad) built in cooperation between RWTH University and Institut Laue-Langevin. In this report we describe the realization and present the performance of the new Cryopad on POLI...
October 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27801462/calcium-complexation-and-acid-base-properties-of-l-gulonate-a-diastereomer-of-d-gluconate
#12
Bence Kutus, Ákos Buckó, Gábor Peintler, István Pálinkó, Pál Sipos
The Ca(ii)-complexation and acid-base properties of l-gulonic acid (HGul), a diastereomer of d-gluconic acid (HGluc) differing only in the configurations of C2 and C5 have been investigated via(1)H and (13)C NMR spectroscopies, Ca-ISE- and pH-potentiometry, polarimetry and freezing point depression. Data obtained for Gul(-)/HGul have been compared with those of Gluc(-)/HGluc. It was found that some properties (acid dissociation constant, the stoichiometry and formation constants of the Ca(ii)-complexes) were insensitive to the difference in the configuration...
November 1, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/27771797/sex-pheromone-of-the-cotton-mealybug-phenacoccus-solenopsis-with-an-unusual-cyclobutane-structure
#13
Jun Tabata, Ryoko T Ichiki
The cotton mealybug, Phenacoccus solenopsis, the distribution of which was formerly limited to Nearctic and Neotropical regions, recently invaded many countries in various regions including Asia, Africa, and the Pacific. More recently, P. solenopsis was newly recorded in Japan and is currently an emerging pest of agricultural crops. In this study, we determined the structure of a sex pheromone of P. solenopsis in order to develop an effective lure for monitoring this pest. From volatiles emitted by virgin adult females, we isolated a compound attractive to males...
November 2016: Journal of Chemical Ecology
https://www.readbyqxmd.com/read/27734938/rapid-detection-of-necrosis-in-breast-cancer-with-desorption-electrospray-ionization-mass-spectrometry
#14
Alessandra Tata, Michael Woolman, Manuela Ventura, Nicholas Bernards, Milan Ganguly, Adam Gribble, Bindesh Shrestha, Emma Bluemke, Howard J Ginsberg, Alex Vitkin, Jinzi Zheng, Arash Zarrine-Afsar
Identification of necrosis in tumors is of prognostic value in treatment planning, as necrosis is associated with aggressive forms of cancer and unfavourable outcomes. To facilitate rapid detection of necrosis with Mass Spectrometry (MS), we report the lipid MS profile of necrotic breast cancer with Desorption Electrospray Ionization Mass Spectrometry (DESI-MS) imaging validated with statistical analysis and correlating pathology. This MS profile is characterized by (1) the presence of the ion of m/z 572.48 [Cer(d34:1) + Cl](-) which is a ceramide absent from the viable cancer subregions; (2) the absence of the ion of m/z 391...
October 13, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27661884/design-trade-off-and-proof-of-concept-for-loupe-the-lunar-observatory-for-unresolved-polarimetry-of-earth
#15
H J Hoeijmakers, M L J Arts, F Snik, C U Keller, J M Kuiper
We provide a proof of the technical feasibility of LOUPE, the first integral-field snapshot spectropolarimeter, designed to monitor the reflected flux and polarization spectrum of Earth. These are to be used as benchmark data for the retrieval of biomarkers and atmospheric and surface characteristics from future direct observations of exoplanets. We perform a design trade-off for an implementation in which LOUPE performs snapshot integral-field spectropolarimetry at visible wavelengths. We used off-the-shelf optics to construct a polarization modulator, in which polarization information is encoded into the spectrum as a wavelength-dependent modulation, while spatial resolution is maintained using a micro-lens array...
September 19, 2016: Optics Express
https://www.readbyqxmd.com/read/27661878/mueller-imaging-polarimetry-of-holographic-polarization-gratings-inscribed-in-azopolymer-films
#16
Geminiano Martinez-Ponce
Three types of polarization gratings have been recorded in azopolymer films by the symmetrical superposition of different orthogonal pairs of polarized beams. The inscribed holographic elements have been analyzed microscopically in a Mueller polarimeter in order to image the optical anisotropies photoinduced in the film. In the most of cases, the spatial modulation of diattenuation, birefringence, and optical rotation reproduced quite well previous results reported in the literature. Nevertheless, in the particular case of coherent superposition of p- and s-polarized beams, the spatial frequency for optical rotation (related to the Stokes parameter V) was different from the one observed in linear anisotropy (related to the Stokes parameter U)...
September 19, 2016: Optics Express
https://www.readbyqxmd.com/read/27617640/dichroism-in-helicoidal-crystals
#17
Xiaoyan Cui, Shane M Nichols, Oriol Arteaga, John Freudenthal, Froilanny Paula, Alexander G Shtukenberg, Bart Kahr
Accounting for the interactions of light with heterogeneous, anisotropic, absorbing, optically active media is part of the characterization of complex, transparent materials. Stained biological structures in thin tissue sections share many of these features, but systematic optical analyses beyond the employ of the simple petrographic microscopes have not be established. Here, this accounting is made for polycrystalline, spherulitic bundles of twisted d-mannitol lamellae grown from melts containing light-absorbing molecules...
September 21, 2016: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/27607968/general-formalism-for-partial-spatial-coherence-in-reflection-mueller-matrix-polarimetry
#18
Razvigor Ossikovski, Kurt Hingerl
Starting from the first principles, we derive the expressions governing partially coherent Mueller matrix reflection polarimetry on spatially inhomogeneous samples. These are reported both in their general form and in the practically important specific form for two juxtaposed media.
September 1, 2016: Optics Letters
https://www.readbyqxmd.com/read/27531315/synthetic-and-organocatalytic-studies-of-quinidine-analogues-with-ring-size-modifications-in-the-quinuclidine-moiety
#19
Arjen C Breman, Gydo van der Heijden, Jan H van Maarseveen, Steen Ingemann, Henk Hiemstra
Six highly enantiopure analogues of [2.2.2] were synthesized with five- or seven-membered rings in the (original) quinuclidine skeleton. Five of these compounds were prepared through epoxide opening by a secondary cyclic amine, providing the nor- and homoquinuclidine moieties through five- and six-membered ring formation. This method failed in the case of seven-membered ring formation, so for that particular ring size a different synthetic route starting from 3-quinuclidone was applied. The six novel analogues were examined as organocatalysts in four asymmetric conjugate addition reactions and the results compared with those of known cinchona alkaloid catalysts...
September 26, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27530742/reversible-and-irreversible-emergence-of-chiroptical-signals-in-j-aggregates-of-achiral-4-sulfonatophenyl-substituted-porphyrins-intrinsic-chirality-vs-chiral-ordering-in-the-solution
#20
Oriol Arteaga, Zoubir El-Hachemi, Adolf Canillas, Joaquim Crusats, Meritxell Rovira, Josep M Ribó
Mueller matrix polarimetry distinguishes the different origins of the reversible and irreversible chiroptical effects emerging in stirred solutions of J-aggregate nanoparticles: the reversible effect is due to an anisotropic ordering in the solution and the irreversible one is due to a bias from the racemic composition of intrinsically chiral structures.
September 18, 2016: Chemical Communications: Chem Comm
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