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Sample records for charged photofragment coincidence

  1. Molecular ion photofragment spectroscopy

    International Nuclear Information System (INIS)

    A new molecular ion photofragment spectrometer is described which features a supersonic molecular beam ion source and a radio frequency octapole ion trap interaction region. This unique combination allows several techniques to be applied to the problem of detecting a photon absorption event of a molecular ion. In particular, it may be possible to obtain low resolution survey spectra of exotic molecular ions by using a direct vibrational predissociation process, or by using other more indirect detection methods. The use of the spectrometer is demonstrated by measuring the lifetime of the O2+(4π/sub u/) metastable state which is found to consist of two main components: the 4π/sub 5/2/ and 4π/sub -1/2/ spin components having a long lifetime (approx. 129 ms) and the 4π/sub 3/2/ and 4π/sub 1/2/ spin components having a short lifetime (approx. 6 ms)

  2. Molecular ion photofragment spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bustamente, S.W.

    1983-11-01

    A new molecular ion photofragment spectrometer is described which features a supersonic molecular beam ion source and a radio frequency octapole ion trap interaction region. This unique combination allows several techniques to be applied to the problem of detecting a photon absorption event of a molecular ion. In particular, it may be possible to obtain low resolution survey spectra of exotic molecular ions by using a direct vibrational predissociation process, or by using other more indirect detection methods. The use of the spectrometer is demonstrated by measuring the lifetime of the O/sub 2//sup +/(/sup 4/..pi../sub u/) metastable state which is found to consist of two main components: the /sup 4/..pi../sub 5/2/ and /sup 4/..pi../sub -1/2/ spin components having a long lifetime (approx. 129 ms) and the /sup 4/..pi../sub 3/2/ and /sup 4/..pi../sub 1/2/ spin components having a short lifetime (approx. 6 ms).

  3. Fast Beam Investigations of Two- and Three-Body Photodissociation by Time- and Position-Coincidence Imaging

    OpenAIRE

    Crider, Paul

    2010-01-01

    Fast beam photofragment translational spectroscopy has been used to elucidate the photodissociation dynamics of small radicals and closed-shell anions. Imaging of photofragments in time- and position-coincidence allows the determination of mass distributions, translational energy distributions [P(ET) distributions], and in the case of three-body fragmentation channels, ternary Dalitz plots depicting the momentum disposal among the fragments. These data yield information about the potential en...

  4. Light charged particles emitted in coincidence with deeply inelastic collisions in the 280MeV 40Ar+58Ni reaction

    International Nuclear Information System (INIS)

    A detailed study of the light charged particles (mainly protons and alpha particles) has been undertaken in coincidence with the main fragments from DIC in the reaction 280 MeV 40Ar + 58Ni. This study is divided in three sections. The first one is a quick survey of the preexisting data on the 40Ar + 58Ni that are relevant to this particular experiment. The second one deals mainly with the origin of the light charged particles as it can be deduced from the p, α-fragments coincidence experiment. Finally, the third section is devoted to the tangential friction aspects. The results of the out-of-plane distributions of the α-particles are presented and they are discussed in term of the extreme sticking limit

  5. Photofragment Translational Spectroscopy of Propargyl Radicals at 248 nm

    Energy Technology Data Exchange (ETDEWEB)

    Goncher, S.J.; Moore, D.T.; Sveum, N.E.; Neumark, D.M.

    2007-12-21

    The photodissociation of propargyl radical, C{sub 3}H{sub 3}, and its perdeuterated isotopolog was investigated using photofragment translational spectroscopy. Propargyl radicals were produced by 193 nm photolysis of allene entrained in a molecular beam expansion, and then photodissociated at 248 nm. photofragment time-of-flight spectra were measured at a series of laboratory angles using electron impact ionization coupled to a mass spectrometer. Data for ion masses corresponding to C{sub 3}H{sub 2}{sup +}, C{sub 3}H{sup +}, C{sub 3}{sup +}, and the analogous deuterated species show that both H and H{sub 2} loss occur. The translational energy distributions for these processes have average values = 5.7 and 15.9 kcal/mol, respectively, and are consistent with dissociation on the ground state following internal conversion, with no exit barrier for H loss but a tight transition state for H{sub 2} loss. The translational energy distribution for H atom loss is similar to that in previous work on propargyl in which the H atom, rather than the heavy fragment, was detected. The branching ratio for H loss/H{sub 2} loss was determined to be 97.6/2.4 {+-} 1.2, in good agreement with RRKM results.

  6. Evidence of a two-source emission fo light charged particles in coincidence with pions produced in sup 16 O+ sup 27 Al collisions at 94 MeV/nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Barbera, R.; Badala, A.; Adorno, A.; Bonasera, A.; Di Toro, M.; Palmeri, A.; Pappalardo, G.S. (Istituto Nazionale di Fisica Nucleare, Catania (Italy)); Bizard, G.; Bougault, R.; Durand, D.; Genoux-Lubain, A.; Laville, J.L.; Lefebvres, F.; Patry, J.P. (Caen Univ., 14 (France). Lab. de Physique Corpusculaire); Jin, G.M. (Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)); Rosato, E. (Naples Univ. (Italy). Dipt. di Scienze Fisiche Istituto Nazionale di Fisica Nucleare, Naples (Italy))

    1990-11-26

    H and He ions have been detected in coincidence with charged pions in the reaction induced by {sup 16}O on {sup 27}Al target at 94 MeV/u incident energy. We analyse velocity spectra and cross sections of He ions emitted in the angular range 4deg-150deg in coincidence with charged pions detected at 90deg. A two-source emission mechanism of the helium particles and a pion statistical production from an equilibrated participant zone is stressed. The absolute yields at different angles are compared with results of a theoretical model for medium energy heavy-ion reactions in the framework of a participant-spectator picture. (orig.).

  7. An investigation of polarized atomic photofragments using the ion imaging technique

    Energy Technology Data Exchange (ETDEWEB)

    Bracker, A.S.

    1997-12-01

    This thesis describes measurement and analysis of the recoil angle dependence of atomic photofragment polarization (atomic v-J correlation). This property provides information on the electronic rearrangement which occurs during molecular photodissociation. Chapter 1 introduces concepts of photofragment vector correlations and reviews experimental and theoretical progress in this area. Chapter 2 described the photofragment ion imaging technique, which the author has used to study the atomic v-J correlation in chlorine and ozone dissociation. Chapter 3 outlines a method for isolating and describing the contribution to the image signal which is due exclusively to angular momentum alignment. Ion imaging results are presented and discussed in Chapter 4. Chapter 5 discusses a different set of experiments on the three-fragment dissociation of azomethane. 122 refs.

  8. Photodestruction of NO2- using time resolved multicoincidence detection photofragment spectroscopy

    NARCIS (Netherlands)

    Dinu, L.; Zande, W.J. van der

    2004-01-01

    We present an experiment on the photodestruction of the NO2- anion at 266 nm. We have quantified the competition between photodetachment and photodissociation and have identified the nature of the photodissociation process from the photofragment angular distribution. This study involves a novel tech

  9. Photodissociation dynamics of the methyl perthiyl radical at 248 and 193 nm using fast-beam photofragment translational spectroscopy

    Science.gov (United States)

    Harrison, Aaron W.; Ryazanov, Mikhail; Sullivan, Erin N.; Neumark, Daniel M.

    2016-07-01

    The photodissociation dynamics of the methyl perthiyl radical (CH3SS) have been investigated using fast-beam coincidence translational spectroscopy. Methyl perthiyl radicals were produced by photodetachment of the CH3SS- anion followed by photodissociation at 248 nm (5.0 eV) and 193 nm (6.4 eV). Photofragment mass distributions and translational energy distributions were measured at each dissociation wavelength. Experimental results show S atom loss as the dominant (96%) dissociation channel at 248 nm with a near parallel, anisotropic angular distribution and translational energy peaking near the maximal energy available to ground state CH3S and S fragments, indicating that the dissociation occurs along a repulsive excited state. At 193 nm, S atom loss remains the major fragmentation channel, although S2 loss becomes more competitive and constitutes 32% of the fragmentation. The translational energy distributions for both channels are very broad at this wavelength, suggesting the formation of the S2 and S atom products in several excited electronic states.

  10. Double coincidence matrix

    International Nuclear Information System (INIS)

    To increase the accuracy of discrimination of true coincidences against the background of accidental ones, circuit has been developed which operates on the principle of dynamic equalization of resolution times of two coincidence circuits. The flowsheet of a 4x6 double-coincidence matrix is given. The principal elements of the matrix are commutators and output signal shapers. The matrix uses 138-series microcircuits. The resolution time of coincidence circuits is 10 ns, the dead time is 25 ns. The results of testing the matrix during experiments under conditions of a high background of accidental coincidences (70-90%) have shown that the accuracy of discrimination of true coincidences with the help of the double-coincidence matrix approximates the accuracy of time-to-digital converters within the limits of the statistical accuracy

  11. Coincidence and modality

    OpenAIRE

    Kang, Li

    2011-01-01

    How should we understand de re modal features of objects, if there are such features? Any answer to the question is connected to how we should think about coincident objects, objects which occupy the same spatio-temporal region and share the same underlying matter. This thesis is mainly about the connections between de re modality and coincidence. My interest in the connections is twofold: First, how do theories of de re modality interact with theories about coincidence? Details of interactio...

  12. Enhanced sensitivity in H photofragment detection by two-color reduced-Doppler ion imaging

    Science.gov (United States)

    Epshtein, Michael; Portnov, Alexander; Kupfer, Rotem; Rosenwaks, Salman; Bar, Ilana

    2013-11-01

    Two-color reduced-Doppler (TCRD) and one-color velocity map imaging (VMI) were used for probing H atom photofragments resulting from the ˜243.1 nm photodissociation of pyrrole. The velocity components of the H photofragments were probed by employing two counterpropagating beams at close and fixed wavelengths of 243.15 and 243.12 nm in TCRD and a single beam at ˜243.1 nm, scanned across the Doppler profile in VMI. The TCRD imaging enabled probing of the entire velocity distribution in a single pulse, resulting in enhanced ionization efficiency, as well as improved sensitivity and signal-to-noise ratio. These advantages were utilized for studying the pyrrole photodissociation at ˜243.1 and 225 nm, where the latter wavelength provided only a slight increase in the H yield over the self-signal from the probe beams. The TCRD imaging enabled obtaining high quality H+ images, even for the low H photofragment yields formed in the 225 nm photolysis process, and allowed determining the velocity distributions and anisotropy parameters and getting insight into pyrrole photodissociation.

  13. Enhanced sensitivity in H photofragment detection by two-color reduced-Doppler ion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Epshtein, Michael; Portnov, Alexander; Kupfer, Rotem; Rosenwaks, Salman; Bar, Ilana, E-mail: ibar@bgu.ac.il [Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)

    2013-11-14

    Two-color reduced-Doppler (TCRD) and one-color velocity map imaging (VMI) were used for probing H atom photofragments resulting from the ∼243.1 nm photodissociation of pyrrole. The velocity components of the H photofragments were probed by employing two counterpropagating beams at close and fixed wavelengths of 243.15 and 243.12 nm in TCRD and a single beam at ∼243.1 nm, scanned across the Doppler profile in VMI. The TCRD imaging enabled probing of the entire velocity distribution in a single pulse, resulting in enhanced ionization efficiency, as well as improved sensitivity and signal-to-noise ratio. These advantages were utilized for studying the pyrrole photodissociation at ∼243.1 and 225 nm, where the latter wavelength provided only a slight increase in the H yield over the self-signal from the probe beams. The TCRD imaging enabled obtaining high quality H{sup +} images, even for the low H photofragment yields formed in the 225 nm photolysis process, and allowed determining the velocity distributions and anisotropy parameters and getting insight into pyrrole photodissociation.

  14. Imaging with coincidence detectors

    International Nuclear Information System (INIS)

    The development of a dual-detector, single photon emission computed tomography (SPECT) system that could be modified to perform coincidence imaging of positron-emitting radiotracers has resulted in a renaissance in the nuclear medicine community. In 1996, ADAC Laboratories introduced their Molecula Coincidence Detection (MCD) system at the Society of Nuclear Medicine Annual General Meeting in Denver. This ushered in a new era in nuclear medicine imaging. The ability of these coincidence systems to image 18FDG promises to make this type of imaging 'just another nuclear medicine procedure', possible within the next decade. This advancement is arguably the biggest news in nuclear medicine since the development of SPECT. In August 1997, Lion's Gate Hospital in North Vancouver acquired the MCD upgrade to their ADAC Vertex camera - the first and only to date in Canada. This article introduces coincidence imaging and describes the experiences of those pioneering the use of this new modality in Canada

  15. Mass-analyzed velocity map imaging of doubly charged photofragments from C70

    Science.gov (United States)

    Katayanagi, Hideki; Mitsuke, Koichiro

    2011-10-01

    The velocity distributions of the fragments produced by dissociative photoionization of C70 have been measured at several photon energies in the extreme UV region, by using a flight-time resolved velocity map imaging (VMI) technique combined with a high-temperature molecular beam and synchrotron radiation. Average kinetic energy release was estimated for the six reaction steps of consecutive C2 emission, starting from C702+ → C682+ + C2 to C602+→ C582+ + C2. The total kinetic energy generated in each step shows a general tendency to increase with increasing hν, except for the first and fifth steps. This propensity reflects statistical redistributions of the excess energy in the transition states for the above fragmentation mechanism. Analysis based on the finite-heat-bath theory predicts the detectable minimum cluster sizes at the end of the C2-emission decay chain. They accord well with the minimum sizes of the observed ions, if the excess energy in the primary C702+ is assumed to be smaller by ˜15 eV than the maximum available energy. The present VMI experiments reveal remarkably small kinetic energy release in the fifth step, in contradiction to theoretical predictions, which suggests involvement of other fragmentation mechanisms in the formation of C602+.

  16. A new tandem mass spectrometer for photofragment spectroscopy of cold, gas-phase molecular ions

    International Nuclear Information System (INIS)

    We present here the design of a new tandem mass spectrometer that combines an electrospray ion source with a cryogenically cooled ion trap for spectroscopic studies of cold, gas-phase ions. The ability to generate large ions in the gas phase without fragmentation, cool them to ∼10 K in an ion trap, and perform photofragment spectroscopy opens up new possibilities for spectroscopic characterization of large biomolecular ions. The incorporation of an ion funnel, together with a number of small enhancements, significantly improves the sensitivity, signal stability, and ease of use compared with the previous instrument built in our laboratory.

  17. Coincidence Auger spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Penent, F. [LCPMR, Universite Pierre et Marie Curie, 75231 Paris 5 (France) and DIAM, Universite Pierre et Marie Curie, 75252 Paris 5 (France)]. E-mail: penent@ccr.jussieu.fr; Lablanquie, P. [LURE, Universite Paris Sud, 91898 Orsay (France); Hall, R.I. [DIAM, Universite Pierre et Marie Curie, 75252 Paris 5 (France); Palaudoux, J. [LCPMR, Universite Pierre et Marie Curie, 75231 Paris 5 (France); Ito, K. [Photon Factory, IMSS, KEK, Tsukuba 305-0801 (Japan); Hikosaka, Y. [Photon Factory, IMSS, KEK, Tsukuba 305-0801 (Japan); IMS, Okazaki 444-8585 (Japan); Aoto, T. [Photon Factory, IMSS, KEK, Tsukuba 305-0801 (Japan); Eland, J.H.D. [Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3DW (United Kingdom)

    2005-06-15

    Auger electron spectroscopy (AES) and photoelectron spectroscopy (PES) are (with X-ray emission spectroscopy, XES) powerful analytical tools for material science and gas phase studies. However, the interpretation of Auger spectra can be very difficult due to the number and complexity of the involved processes. A deeper analysis, that allows a better understanding of relaxation processes following inner shell ionization, is possible with coincidence Auger spectroscopy. This method gives a new insight into electron correlation and allows disentangling of complex Auger electron spectra. In this paper, we present some examples related to gas phase coincidence Auger electron spectroscopy using synchrotron radiation. The detection in coincidence of an Auger electron with a threshold photoelectron presents two main advantages which are good energy resolution and high coincidence count rates. This technique has also provided new results on double Auger decay processes. A further qualitative breakthrough has been made with the development of a new experimental set-up based on a magnetic bottle time-of-flight electron spectrometer. This opens up the field of multi-electron coincidence spectroscopy and allows a most detailed analysis with characterization of all possible decay pathways following inner shell ionization.

  18. Ultraviolet photodissociation of C2F5I with a small and simple photofragment translational spectrometer.

    Science.gov (United States)

    Yu, Zijun; Xu, Xiling; Cheng, Min; Yu, Dan; Du, Yikui; Zhu, Qihe

    2009-07-28

    Photodissociation dynamics of C(2)F(5)I near 280 and 304 nm has been investigated on a small and simple time-of-flight photofragment translational spectrometer (PTS). On this new PTS, the photolyzed and ionized fragments, not accelerated by electric field, travel freely for a short flight path (CF(2) wag mode (nu(11)=366 cm(-1)) of C(2)F(5) photofragment. The fraction of the available energy disposed into the internal energy is higher than 50% for both I(*) channel and I channel, showing the high excitation of vibration in the C(2)F(5) fragments. The fragment recoil anisotropy parameter beta(I(*)), determined to be 1.70 at 281.73 nm and 1.64 at 304.02 nm, reveals that I(*) atoms are produced predominantly from the parallel (3)Q(0) bending" mode on alpha-carbon of alkyl iodides is the preferential vibrational excitation mode, which can be explained by the classic impulsive model. PMID:19655883

  19. Coincidence studies with antiprotons

    Energy Technology Data Exchange (ETDEWEB)

    McGovern, M; Walters, H R J [Department of Applied Mathematics and Theoretical Physics, Queen' s University, Belfast BT7 1NN (United Kingdom); Assafrao, D; Mohallem, J R [Laboratorio de Atomos e Moleculas Especiais, Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, P.O Box 702, 30123-970 Belo Horizonte, MG (Brazil); Whelan, Colm T, E-mail: mmcgovern06@qub.ac.u [Department of Physics, Old Dominion University, Norfolk, VA 23529-0116 (United States)

    2010-02-01

    We present a short overview of a new method for calculating fully differential cross sections that is able to describe any aspect of coincidence measurements involving heavy projectiles. The method is based upon impact parameter close coupling with pseudostates. Examples from antiproton impact ionization are shown.

  20. A β - γ coincidence

    International Nuclear Information System (INIS)

    A β - γ coincidence method for absolute counting is given. The fundamental principles are revised and the experimental part is detailed. The results from 198 Au irradiated in the JEN 1 Swimming pool reactor are given. The maximal accuracy is 1 per cent. (Author) 11 refs

  1. Unravelling the role of quantum interference in the weak-field laser phase modulation control of photofragment distributions

    DEFF Research Database (Denmark)

    García-Vela, Alberto; Henriksen, Niels Engholm

    2016-01-01

    The role played by quantum interference in the laser phase modulation coherent control of photofragment distributions in the weak-field regime is investigated in detail in this work. The specific application involves realistic wave packet calculations of the transient vibrational populations of t...

  2. Off-resonant vibrational excitation: Orientational dependence and spatial control of photofragments

    DEFF Research Database (Denmark)

    Machholm, Mette; Henriksen, Niels Engholm

    2000-01-01

    randomly oriented heteronuclear diatomic molecules can be obtained under simultaneous irradiation by a resonant and an off-resonant intense IR laser pulse: Molecules with one initial orientation will be vibrationally excited, while those with the opposite orientation will be at rest. The orientation......Off-resonant and resonant vibrational excitation with short intense infrared (IR) laser pulses creates localized oscillating wave packets, but differs by the efficiency of the excitation and surprisingly by the orientational dependence. Orientational selectivity of the vibrational excitation of......-dependent response to the IR fields is due to the anharmonicity of the potential. A subsequent ultraviolet laser pulse in resonance at the outer turning point of the vibrational motion can then dissociate the oscillating molecules, all with the same orientation, leading to spatial control of the photofragment...

  3. Light charged particle and neutron velocity spectra in coincidence with projectile fragments in the reaction sup 4 sup 0 Ar(44 A MeV)+ sup 2 sup 7 Al

    CERN Document Server

    Lanzanò, G; Geraci, M; Pagano, A; Aiello, S; Cunsolo, A; Fonte, R; Foti, A; Sperduto, M L; Volant, C; Charvet, J L; Dayras, R; Legrain, R

    2001-01-01

    We present a three source analysis of velocity spectra of light charged particles (LCP) and neutrons emitted in the reaction sup 4 sup 0 Ar+ sup 2 sup 7 Al at 44 A MeV. The light particle (LP) velocity spectra are studied as a function of the detection angle (1.5 deg. charge of the forward detected projectile-like fragment (PLF). The temperature parameter, the velocity and the intensity of each source are extracted as a function of the PLF charge. While the temperature parameters for PLF and target-like fragments (TLF) are very similar and show a dependence on the PLF charge, the temperature parameter for the intermediate source is approximately 15 MeV, independent of the PLF charge. Comparison with temperature values extracted from double isotopic ratios, shows an agreement only between the temperature values extracted from formula involving sup 3 He, sup 4 He, d, t ratios and the PLF proton temperature parameter. The characteristics of the PLF sources are derived. Present ...

  4. COINCIDENCE PROBLEMS FOR GENERALIZED CONTRACTIONS

    Directory of Open Access Journals (Sweden)

    Jesús Garcia Falset

    2014-03-01

    Full Text Available In this paper, we establish some new existence, uniqueness and Ulam-Hyers stability theorems for coincidence problems for two single-valued mappings. The main results of this paper extend the results presented in {\\sc O. Mle\\c sni\\c te:} \\emph{Existence and Ulam-Hyers stability results for coincidence problems}, J. Nonlinear Sci.\\ Appl., \\textbf{6} (2013, 108--116. In the last section two examples of application of these results are also given.

  5. The parity-adapted basis set in the formulation of the photofragment angular momentum polarization problem: the role of the Coriolis interaction.

    Science.gov (United States)

    Shternin, Peter S; Vasyutinskii, Oleg S

    2008-05-21

    We present a theoretical framework for calculating the recoil-angle dependence of the photofragment angular momentum polarization taking into account both radial and Coriolis nonadiabatic interactions in the diatomic/linear photodissociating molecules. The parity-adapted representation of the total molecular wave function has been used throughout the paper. The obtained full quantum-mechanical expressions for the photofragment state multipoles have been simplified by using the semiclassical approximation in the high-J limit and then analyzed for the cases of direct photodissociation and slow predissociation in terms of the anisotropy parameters. In both cases, each anisotropy parameter can be presented as a linear combination of the generalized dynamical functions fK(q,q',q,q') of the rank K representing contribution from different dissociation mechanisms including possible radial and Coriolis nonadiabatic transitions, coherent effects, and the rotation of the recoil axis. In the absence of the Coriolis interactions, the obtained results are equivalent to the earlier published ones. The angle-recoil dependence of the photofragment state multipoles for an arbitrary photolysis reaction is derived. As shown, the polarization of the photofragments in the photolysis of a diatomic or a polyatomic molecule can be described in terms of the anisotropy parameters irrespective of the photodissociation mechanism.

  6. Video Histories, Memories, and Coincidences

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    2012-01-01

    Looping images allows us to notice things that we have never noticed before. Looping a small but exquisite selection of the video tapes of Marcel Odenbach, Dieter Kiessling and Matthias Neuenhofer may allow the discovering of Histories, Coincidences, and Infinitesimal Aesthetics inscribed...... into the Video medium as its unsurpassed topicality....

  7. Unravelling the role of quantum interference in the weak-field laser phase modulation control of photofragment distributions.

    Science.gov (United States)

    García-Vela, Alberto; Henriksen, Niels E

    2016-02-14

    The role played by quantum interference in the laser phase modulation coherent control of photofragment distributions in the weak-field regime is investigated in detail in this work. The specific application involves realistic wave packet calculations of the transient vibrational populations of the Br2(B,vf) fragment produced upon predissociation of the Ne-Br2(B) complex, which is excited to a superposition of overlapping resonance states using different fixed bandwidth pulses where the linear chirps are varied. The postpulse transient phase modulation effects observed on fragment populations for a long time window are explained in terms of the mechanism of interference between overlapping resonances. A detailed description of how the interference mechanism affects the magnitude and the time window of the phase control effects is also provided. In the light of the results, the conditions to maximize phase modulation control on fragment distributions are discussed. PMID:26799495

  8. Unravelling the role of quantum interference in the weak-field laser phase modulation control of photofragment distributions.

    Science.gov (United States)

    García-Vela, Alberto; Henriksen, Niels E

    2016-02-14

    The role played by quantum interference in the laser phase modulation coherent control of photofragment distributions in the weak-field regime is investigated in detail in this work. The specific application involves realistic wave packet calculations of the transient vibrational populations of the Br2(B,vf) fragment produced upon predissociation of the Ne-Br2(B) complex, which is excited to a superposition of overlapping resonance states using different fixed bandwidth pulses where the linear chirps are varied. The postpulse transient phase modulation effects observed on fragment populations for a long time window are explained in terms of the mechanism of interference between overlapping resonances. A detailed description of how the interference mechanism affects the magnitude and the time window of the phase control effects is also provided. In the light of the results, the conditions to maximize phase modulation control on fragment distributions are discussed.

  9. Coincident Indicators of Capital Flows

    OpenAIRE

    Malika Pant; Yanliang Miao

    2012-01-01

    Capital flows data from Balance of Payments statistics often lag 3-6 months, which renders timely surveillance and policy deliberation difficult. To address the tension, we propose two coincident composite indicators for capital flows that improve upon existing proxies. We find that the most widely used proxy, the capital tracker, often overpredicts net flows by 30 percent. We augment the tracker into a composite indicator by assigning to it a lesser but optimally estimated weight while incor...

  10. Dissociation dynamics of highly excited molecules produced by charge exchange: Two-body dynamics of CH5 and three-body dynamics of sym-triazine

    International Nuclear Information System (INIS)

    Translational spectroscopy and coincidence detection of the neutral photofragments have been used to observe the dissociation dynamics of highly excited neutrals produced by charge exchange between keV cation beams with Cs, and the results from two novel systems are presented. CH5 is formed slightly above the 3s Rydberg level and dissociates into two possible fragmentation channels, H loss and H2 loss. The kinetic energy release distributions of the two products are presented and the branching ratio between the two is found to be 11.4 ± 1.5 : 1 with the H loss being the dominant channel. Production of the highly symmetric azabenzene sym-triazine in its 3s Rydberg state has been shown to induce dissociation to 3 HCN(Σ+). Examination of momentum correlation in the dissociation products shows that this dissociation occurs by two distinct mechanisms. Evidence from Monte Carlo simulations suggest a sequential mechanism occurs creating products accompanied by a kinetic energy release of ∼1.5-5 eV. A symmetric concerted mechanism is also observed and is associated with products receiving a 2-4 eV kinetic energy release.

  11. Subthreshold production of pions in coincidence with light particles

    Energy Technology Data Exchange (ETDEWEB)

    Barbera, R.; Badala, A.; Adorno, A.; Bonasera, A.; Di Toro, M.; Palmeri, A.; Pappalardo, G.S.; Riggi, F.; Russo, G. (Istituto Nazionale di Fisica Nucleare, Catania (Italy)); Bizard, G.; Durand, D.; Laville, J.L. (Caen Univ., 14 (France). Lab. de Physique Corpusculaire); Jin, G.M. (Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)); Rosato, E. (Naples Univ. (Italy). Dipt. di Scienze Fisiche Istituto Nazionale di Fisica Nucleare, Naples (Italy))

    1990-12-03

    He ions have been detected in coincidence with charged pions in the reaction {sup 16}O on {sup 27}Al at E{sub lab}=94 MeV/u. We analyse velocity spectra and cross-sections of He ions emitted in the angular range 4deg/150deg in coincidence with charged pions detected at 90deg. A two source emission mechanism of the helium particles and a pion statistical production from an equilibrated participant zone is stressed. The absolute yields at different angles are compared with results of a theoretical model for medium energy heavy ion reactions in the frame of a participant-spectator picture. A comparison of the pion energy spectra with Boltzmann-Nordheim-Vlasov calculations and a discussion on the time scale for pion emission is also presented. (orig.).

  12. Intermediate photofragment distributions as probes of non-adiabatic dynamics at conical intersections: application to the Hartley band of ozone.

    Science.gov (United States)

    Picconi, David; Grebenshchikov, Sergy Yu

    2015-11-21

    Quantum dynamics at a reactive two-state conical intersection lying outside the Franck-Condon zone is studied for a prototypical reaction of ultraviolet photodissociation of ozone in the Hartley band. The focus is on the vibrational distributions in the two electronic states at intermediate interfragment distances near the intersection. Such intermediate distributions of strongly interacting photofragments contain unique information on the location and shape of the conical intersection. Multidimensional Landau-Zener modeling provides a framework to reverse engineer the molecular geometry-dependent Massey parameter of the intersection from the intermediate distributions. The conceptual approach is demonstrated for the intermediate O-O bond stretch distributions which become strongly inverted on adiabatic passage through the intersection. It is further demonstrated that intermediate distributions can be reconstructed from the photoemission spectrum of the dissociating molecule. The illustration, given using quantum mechanical calculations of resonance Raman profiles for ozone, completes a practicable cycle of conversion of intermediate distributions into topographic features of the conical intersection.

  13. Artifacts in digital coincidence timing.

    Science.gov (United States)

    Moses, W W; Peng, Q

    2014-11-01

    Digital methods are becoming increasingly popular for measuring time differences, and are the de facto standard in PET cameras. These methods usually include a master system clock and a (digital) arrival time estimate for each detector that is obtained by comparing the detector output signal to some reference portion of this clock (such as the rising edge). Time differences between detector signals are then obtained by subtracting the digitized estimates from a detector pair. A number of different methods can be used to generate the digitized arrival time of the detector output, such as sending a discriminator output into a time to digital converter (TDC) or digitizing the waveform and applying a more sophisticated algorithm to extract a timing estimator.All measurement methods are subject to error, and one generally wants to minimize these errors and so optimize the timing resolution. A common method for optimizing timing methods is to measure the coincidence timing resolution between two timing signals whose time difference should be constant (such as detecting gammas from positron annihilation) and selecting the method that minimizes the width of the distribution (i.e. the timing resolution). Unfortunately, a common form of error (a nonlinear transfer function) leads to artifacts that artificially narrow this resolution, which can lead to erroneous selection of the 'optimal' method. The purpose of this note is to demonstrate the origin of this artifact and suggest that caution should be used when optimizing time digitization systems solely on timing resolution minimization. PMID:25321885

  14. Artifacts in digital coincidence timing

    Science.gov (United States)

    Moses, W. W.; Peng, Q.

    2014-11-01

    Digital methods are becoming increasingly popular for measuring time differences, and are the de facto standard in PET cameras. These methods usually include a master system clock and a (digital) arrival time estimate for each detector that is obtained by comparing the detector output signal to some reference portion of this clock (such as the rising edge). Time differences between detector signals are then obtained by subtracting the digitized estimates from a detector pair. A number of different methods can be used to generate the digitized arrival time of the detector output, such as sending a discriminator output into a time to digital converter (TDC) or digitizing the waveform and applying a more sophisticated algorithm to extract a timing estimator. All measurement methods are subject to error, and one generally wants to minimize these errors and so optimize the timing resolution. A common method for optimizing timing methods is to measure the coincidence timing resolution between two timing signals whose time difference should be constant (such as detecting gammas from positron annihilation) and selecting the method that minimizes the width of the distribution (i.e. the timing resolution). Unfortunately, a common form of error (a nonlinear transfer function) leads to artifacts that artificially narrow this resolution, which can lead to erroneous selection of the ‘optimal’ method. The purpose of this note is to demonstrate the origin of this artifact and suggest that caution should be used when optimizing time digitization systems solely on timing resolution minimization.

  15. Using CHIMERA detector at LNS for gamma-particle coincidences

    Directory of Open Access Journals (Sweden)

    Cardella G.

    2016-01-01

    Full Text Available We have recently evaluated the quality of γ-ray angular distributions that can be extracted in particle-gamma coincidence measurements using the CHIMERA detector at LNS. γ-rays have been detected using the CsI(Tl detectors of the spherical part of the CHIMERA array. Very clean γ-rays angular distributions were extracted in reactions induced by different stable beams impinging on 12C thin targets. The results evidenced an effect of projectile spin flip on the γ-rays angular distributions. γ-particle coincidence measurements were also performed in reactions induced by neutron rich exotic beams produced through in-flight fragmentation at LNS. In recent experiments also the Farcos array was used to improve energy and angular resolution measurements of the detected charged particles. Results obtained with both stable and radioactive beams are reported.

  16. Using CHIMERA detector at LNS for gamma-particle coincidences

    Science.gov (United States)

    Cardella, G.; Acosta, L.; Auditore, L.; Chatterjiee, M. B.; Castoldi, A.; De Filippo, E.; Dell'Aquila, D.; De Luca, S.; Gnoffo, B.; Guazzoni, C.; Francalanza, L.; Lanzalone, G.; Lombardo, I.; Martorana, N.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Pirrone, S.; Politi, G.; Quattrocchi, L.; Rizzo, F.; Russotto, P.; Trifirò, A.; Trimarchi, M.; Verde, G.; Vigilante, M.

    2016-05-01

    We have recently evaluated the quality of γ-ray angular distributions that can be extracted in particle-gamma coincidence measurements using the CHIMERA detector at LNS. γ-rays have been detected using the CsI(Tl) detectors of the spherical part of the CHIMERA array. Very clean γ-rays angular distributions were extracted in reactions induced by different stable beams impinging on 12C thin targets. The results evidenced an effect of projectile spin flip on the γ-rays angular distributions. γ-particle coincidence measurements were also performed in reactions induced by neutron rich exotic beams produced through in-flight fragmentation at LNS. In recent experiments also the Farcos array was used to improve energy and angular resolution measurements of the detected charged particles. Results obtained with both stable and radioactive beams are reported.

  17. Redesign of the GATE PET coincidence sorter

    Science.gov (United States)

    Strydhorst, Jared; Buvat, Irène

    2016-09-01

    The GATE software platform, based on the Geant4 toolkit for simulating particle interactions with matter, enables simulation of, among other medical imaging and treatment systems, positron emission tomography. However, at least one publication (Moraes et al 2015 Phys. Med. 31 43–8) has reported discrepancies between the expected results and those obtained using GATE simulations, specifically with respect to the coincidence sorter which processes single events detected by the scanner to find coincidence pairs. In particular, the current software appears to overestimate the number of ‘true’ coincidence pairs when in multi-window mode, while the delayed coincidence window, used to estimate the randoms present in the prompt coincidence window, underestimates the randoms. Both effects are particularly evident at high count rates. We have investigated this discrepancy and reproduced the reported problems. We have also rewritten the relevant portion of the GATE code to correct the issue. In this note we describe the modifications to the coincidence sorter and repeat the simulations which previously showed unexpected results. Some discrepancies remain in the estimation of the randoms with the single-window mode which are a consequence of the algorithm itself. In multi-window mode however, the simulation agrees exactly with the expected results. The modifications to the coincidence sorter code will be incorporated into the next release of GATE (> version 7.2).

  18. Light particle coincidences with gross structure in energy spectra from the 40Ca+40Ca collision

    International Nuclear Information System (INIS)

    Angular correlations between light charged particles and heavy ion fragments from the 40Ca + 40Ca collision have been investigated. The high excitation energy structure previously observed in inclusive experiments is strongly populated in coincidence with protons for calcium and potassium fragments, with alphas for argon fragments. Particles emitted in coincidence with the structure are strongly focused and have a velocity close to the velocity of the beam, whereas the yield of evaporation decay is very small

  19. Perturbative corrections to photon coincidence spectroscopy

    OpenAIRE

    Horvath, L.; Sanders, B. C.

    2000-01-01

    Photon coincidence spectroscopy is a promising technique for probing the nonlinear regime of cavity quantum electrodynamics in the optical domain, however its accuracy is mitigated by two factors: higher-order photon correlations, which contribute to an enhanced pair count rate, and non-simultaneity of emitted photon pairs from the optical cavity. We show that the technique of photon coincidence spectroscopy is effective in the presence of these effects if the quantitative predictions are adj...

  20. Grain-boundary structures in hexagonal materials: Coincident and near coincident grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, D. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Materials Science and Engineering)

    1994-07-01

    Embedded atom method (EAM) simulations of the structure of grain boundaries in hexagonal metal, are presented. The simulations use recently developed interatomic potentials for Ti and Co. Structures were calculated for various symmetrical tilt boundaries with the [1,100] tilt axis. The structures obtained for both metals are very similar. The energies for the Co boundaries are higher than those for Ti by a factor of 2. The structural unit model was applied to the computed grain-boundary structures in these hexagonal materials. As in cubic materials, the structural unit model can describe a series of symmetrical tilt coincident boundaries. In addition, when the coincidence ratio in the grain-boundary plane varies with the c/a ratio, a structural unit-type model can describe the variation of grain-boundary structure with c/a ratio. This model is adequate for describing series of symmetrical tilt boundaries with the grain-boundary plane oriented perpendicular to a fixed crystallographic direction and varying c/a ratios. For the structures of the so-called near coincident boundaries that appear in these materials, it was concluded that near coincident boundaries behave similarly to exact coincidence boundaries if there is a coincident periodic structure in the grain-boundary plane. This may occur even without a three-dimensional (3-D) coincident site lattice.

  1. Mass spectrometric analysis with cluster projectiles and coincidence counting

    Energy Technology Data Exchange (ETDEWEB)

    Cox, B.D.

    1992-01-01

    Methods for maximizing the amount of secondary ion information, per primary projectile, are described. The method is based on time-of-flight mass spectrometry and event-by-event coincidence counting. The information obtained from coincidence counting time-of-flight mass spectrometry includes: (a) surface composition, (b) relative concentrations, and (c) degree of intermolecular mixing. The technique was applied to the study of an important new class of polymers: polymer blends. Secondary ion mass spectrometry, when applied to the analysis of synthetic polymers, induces backbone fragmentation which is characteristic of the homopolymer. The characteristic fingerprint peaks from polystyrene and poly(vinyl methyl ether) were used to identify the presence of these two polymers in a polymer blend. The percent coincidence between the characteristic secondary ions from each component of the blend were used to determine both the relative concentration and the degree of molecular mixing. Results indicate molecular segregation of the two polymers on the film surface. The largest degree of segregation was determined for the phase separated blends. The performance of this technique depends on the desorption efficiency of the primary projectiles. In practice one seeks primary ions which are surface sensitive, have controllable parameters such as size, velocity, and charge state, and generate high secondary ion yields. Focus was placed on the use of keV organic cluster projectiles to meet these criteria. Of interest to this study were C[sub 18] (chrysene), C[sub 24] (coronene), and C[sub 60] (buckminster-fulleren). Results indicate enhanced secondary ion yields for C[sub 60]. For example, when CsI is bombarded with 30 keV C[sub 60], the yields for I[sup [minus

  2. Wardowski conditions to the coincidence problem

    Directory of Open Access Journals (Sweden)

    David eAriza-Ruiz

    2015-08-01

    Full Text Available In this article we □rst discuss the existence and uniqueness of a solution for the coincidence problem:Find $p in X$ such that Tp = Sp; where X is a nonempty set, Y is a complete metric space, and$T; S : X to Y$ are two mappings satisfying a Wardowski type condition of contractivity. Later on, wewill state the convergence of the Picard-Juncgk iteration process to the above coincidence problemas well as a rate of convergence for this iteration scheme. Finally, we shall apply our results to studythe existence and uniqueness of a solution as well as the convergence of the Picard-Juncgk iterationprocess towards the solution of a second order di□erential equation.

  3. Cosmic Coincidences: Investigations for Neutron Background Suppression

    OpenAIRE

    Heimbach, Craig R.

    2007-01-01

    Two experimental investigations were made in order to reduce background counts in neutron detectors. Each investigation relied upon the fact that neutron background is largely due to cosmic ray interactions with the air and ground. The first attempt was to look at neutron arrival times. Neutron events close in time were taken to have been of a common origin due to cosmic rays. The second investigation was similar, but based on coincident neutron/muon events. The investigations showed only a s...

  4. Kinematical coincidence method in transfer reactions

    Energy Technology Data Exchange (ETDEWEB)

    Acosta, L.; Amorini, F. [INFN—Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Auditore, L. [INFN Gruppo Collegato di Messina and Dipartimento di Fisica, Università di Messina (Italy); Berceanu, I. [Institute for Physics and Nuclear Engineering, Bucharest (Romania); Cardella, G., E-mail: cardella@ct.infn.it [INFN—Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); Chatterjiee, M.B. [Saha Institute for Nuclear Physics, Kolkata (India); De Filippo, E. [INFN—Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); Francalanza, L.; Gianì, R. [INFN—Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia, Catania (Italy); Grassi, L. [INFN—Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); Rudjer Boskovic Institute, Zagreb (Croatia); Grzeszczuk, A. [Institut of Physics, University of Silesia, Katowice (Poland); La Guidara, E. [INFN—Sezione di Catania, Via S. Sofia, 95123 Catania (Italy); Centro Siciliano di Fisica Nucleare e Struttura della Materia, Catania (Italy); Lanzalone, G. [INFN—Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Facoltà di Ingegneria e Architettura, Università Kore, Enna (Italy); Lombardo, I. [INFN—Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Dipartimento di Scienze Fisiche, Università Federico II and INFN Sezione di Napoli (Italy); Loria, D.; Minniti, T. [INFN Gruppo Collegato di Messina and Dipartimento di Fisica, Università di Messina (Italy); Pagano, E.V. [INFN—Laboratori Nazionali del Sud, Via S. Sofia, Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia, Catania (Italy); and others

    2013-07-01

    A new method to extract high resolution angular distributions from kinematical coincidence measurements in binary reactions is presented. Kinematics is used to extract the center of mass angular distribution from the measured energy spectrum of light particles. Results obtained in the case of {sup 10}Be+p→{sup 9}Be+d reaction measured with the CHIMERA detector are shown. An angular resolution of few degrees in the center of mass is obtained. The range of applicability of the method is discussed.

  5. Kinematical coincidence method in transfer reactions

    CERN Document Server

    Acosta, L; Auditore, L; Berceanu, I; Cardella, G; Chatterjiee, M B; De Filippo, E; FrancalanzA, L; Gianì, R; Grassi, L; Grzeszczuk, A; La Guidara, E; Lanzalone, G; Lombardo, I; Loria, D; Minniti, T; Pagano, E V; Papa, M; Pirrone, S; Politi, G; Pop, A; Porto, F; Rizzo, F; Rosato, E; Russotto, P; Santoro, S; Trifirò, A; Trimarchi, M; Verde, G; Vigilante, M

    2012-01-01

    A new method to extract high resolution angular distributions from kinematical coincidence measurements in binary reactions is presented. Kinematic is used to extract the center of mass angular distribution from the measured energy spectrum of light particles. Results obtained in the case of 10Be+p-->9Be+d reaction measured with the CHIMERA detector are shown. An angular resolution of few degrees in the center of mass is obtained.

  6. Coincidence measurements of FFTF breeder fuel subassemblies

    International Nuclear Information System (INIS)

    A prototype coincidence counter developed to assay fast breeder reactor fuel was used to measure four fast-flux test facility subassemblies at the Hanford Engineering Development Laboratory in Richland, Washington. Plutonium contents in the four subassemblies ranged between 7.4 and 9.7 kg with corresponding 240Pu-effective contents between 0.9 and 1.2 kg. Large count rates were observed from the measurements, and plots of the data showed significant multiplication in the fuel. The measured data were corrected for deadtime and multiplication effects using established formulas. These corrections require accurate knowledge of the plutonium isotopics and 241Am content in the fuel. Multiplication-corrected coincidence count rates agreed with the expected count rates based on spontaneous fission-neutron emission rates. These measurements indicate that breeder fuel subassemblies with 240Pu-effective contents up to 1.2 kg can be nondestructively assayed using the shift-register electronics with the prototype counters. Measurements using the standard Los Alamos National Laboratory shift-register coincidence electronics unit can produce an assay value accurate to +-1% in 1000 s. The uncertainty results from counting statistics and deadtime-correction errors. 3 references, 8 figures, 8 tables

  7. Coincidence corrections for a multi-detector gamma spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Britton, R., E-mail: r.britton@surrey.ac.uk [University of Surrey, Guildford GU2 7XH (United Kingdom); AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); Burnett, J.L.; Davies, A.V. [AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); Regan, P.H. [University of Surrey, Guildford GU2 7XH (United Kingdom)

    2015-01-01

    List-mode data acquisition has been utilised in conjunction with a high-efficiency γ–γ coincidence system, allowing both the energetic and temporal information to be retained for each recorded event. Collected data is re-processed multiple times to extract any coincidence information from the γ-spectroscopy system, correct for the time-walk of low-energy events, and remove accidental coincidences from the projected coincidence spectra. The time-walk correction has resulted in a reduction in the width of the coincidence delay gate of 18.4±0.4%, and thus an equivalent removal of ‘background’ coincidences. The correction factors applied to ∼5.6% of events up to ∼500 keV for a combined {sup 137}Cs and {sup 60}Co source, and are crucial for accurate coincidence measurements of low-energy events that may otherwise be missed by a standard delay gate. By extracting both the delay gate and a representative ‘background’ region for the coincidences, a coincidence background subtracted spectrum is projected from the coincidence matrix, which effectively removes ∼100% of the accidental coincidences (up to 16.6±0.7% of the total coincidence events seen during this work). This accidental-coincidence removal is crucial for accurate characterisation of the events seen in coincidence systems, as without this correction false coincidence signatures may be incorrectly interpreted.

  8. A method for coincidence timing resolution enhancement

    Science.gov (United States)

    Ermis, E. E.; Celiktas, C.; Pilicer, E.

    2016-05-01

    A method including the coincidence time resolution improvement for a TOF/positron emission tomography system was suggested. The spectrometer for this aim was composed of two NaI(Tl) and two plastic scintillation detectors. Experimental results were supported by FLUKA Monte Carlo simulation program by constructing the detector setup in software medium. Present experimental results verified our previous results and conclusions obtained from the suggested method. It was concluded that better resolutions would help the improvement not only on the TOF gain but also on the spatial resolution, leading to better images and helping the Physician in his/her diagnosis and treatment.

  9. A coincidence detection system based on real-time software

    Science.gov (United States)

    Ayuso, Sindulfo; José Blanco, Juan; Medina, José; Gómez-Herrero, Raúl; García-Población, Oscar; García Tejedor, Ignacio

    2016-09-01

    Conventional real-time coincidence systems use electronic circuitry to detect coincident pulses (hardware coincidence). In this work, a new concept of coincidence system based on real-time software (software coincidence) is presented. This system is based on the recurrent supervision of the analogue-to-digital converters status, which is described in detail. A prototype has been designed and built using a low-cost development platform. It has been applied to two different experimental sets for cosmic ray muon detection. Experimental muon measurements recorded simultaneously using conventional hardware coincidence and our software coincidence system have been compared, yielding identical results. These measurements have also been validated using simultaneous neutron monitor observations. This new software coincidence system provides remarkable advantages such as higher simplicity of interconnection and adjusting. Thus, our system replaces, at least, three Nuclear Instrument Modules (NIMs) required by conventional coincidence systems, reducing its cost by a factor of 40 and eliminating pulse delay adjustments.

  10. Monte Carlo calculations of the neutron coincidence gate utilisation factor for passive neutron coincidence counting

    CERN Document Server

    Bourva, L C A

    1999-01-01

    The general purpose neutron-photon-electron Monte Carlo N-Particle code, MCNP sup T sup M , has been used to simulate the neutronic characteristics of the on-site laboratory passive neutron coincidence counter to be installed, under Euratom Safeguards Directorate supervision, at the Sellafield reprocessing plant in Cumbria, UK. This detector is part of a series of nondestructive assay instruments to be installed for the accurate determination of the plutonium content of nuclear materials. The present work focuses on one aspect of this task, namely, the accurate calculation of the coincidence gate utilisation factor. This parameter is an important term in the interpretative model used to analyse the passive neutron coincidence count data acquired using pulse train deconvolution electronics based on the shift register technique. It accounts for the limited proportion of neutrons detected within the time interval for which the electronics gate is open. The Monte Carlo code MCF, presented in this work, represents...

  11. UV photodesorption of methanol in pure and CO-rich ices: desorption rates of the intact molecule and of the photofragments

    CERN Document Server

    Bertin, Mathieu; Doronin, Mikhail; Philippe, Laurent; Jeseck, Pascal; Litgerink, Niels; Linnartz, Harold; Michaut, Xavier; Fillion, Jean-Hugues

    2016-01-01

    Wavelength dependent photodesorption rates have been determined using synchrotron radiation, for condensed pure and mixed methanol ice in the 7 -- 14 eV range. The VUV photodesorption of intact methanol molecules from pure methanol ices is found to be of the order of 10$^{-5}$ molecules/photon, that is two orders of magnitude below what is generally used in astrochemical models. This rate gets even lower ($<$ 10$^{-6}$ molecules/photon) when the methanol is mixed with CO molecules in the ices. This is consistent with a picture in which photodissociation and recombination processes are at the origin of intact methanol desorption from pure CH$_3$OH ices. Such low rates are explained by the fact that the overall photodesorption process is dominated by the desorption of the photofragments CO, CH$_3$, OH, H$_2$CO and CH$_3$O/CH$_2$OH, whose photodesorption rates are given in this study. Our results suggest that the role of the photodesorption as a mechanism to explain the observed gas phase abundances of methan...

  12. UV PHOTODESORPTION OF METHANOL IN PURE AND CO-RICH ICES: DESORPTION RATES OF THE INTACT MOLECULE AND OF THE PHOTOFRAGMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Bertin, Mathieu; Doronin, Mikhail; Philippe, Laurent; Jeseck, Pascal; Michaut, Xavier; Fillion, Jean-Hugues [LERMA, Sorbonne Universités, UPMC Univ. Paris 06, Observatoire de Paris, PSL Research University, CNRS, F-75252, Paris (France); Romanzin, Claire [LCP (UMR 8000), CNRS, Université Paris-Sud, F-91405 Orsay (France); Ligterink, Niels; Linnartz, Harold [Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands)

    2016-02-01

    Wavelength-dependent photodesorption rates have been determined using synchrotron radiation for condensed pure and mixed methanol ice in the 7–14 eV range. The VUV photodesorption of intact methanol molecules from pure methanol ices is found to be of the order of 10{sup −5} molecules/photon, that is two orders of magnitude below what is generally used in astrochemical models. This rate gets even lower (<10{sup −6} molecules/photon) when the methanol is mixed with CO molecules in the ices. This is consistent with a picture in which photodissociation and recombination processes are at the origin of intact methanol desorption from pure CH{sub 3}OH ices. Such low rates are explained by the fact that the overall photodesorption process is dominated by the desorption of the photofragments CO, CH{sub 3}, OH, H{sub 2}CO, and CH{sub 3}O/CH{sub 2}OH, whose photodesorption rates are given in this study. Our results suggest that the role of the photodesorption as a mechanism to explain the observed gas phase abundances of methanol in cold media is probably overestimated. Nevertheless, the photodesorption of radicals from methanol-rich ices may stand at the origin of the gas phase presence of radicals such as CH{sub 3}O, therefore, opening new gas phase chemical routes for the formation of complex molecules.

  13. Fluorescence Excitation Spectra of Photo-Fragmented Nitrobenzene Using a Picosecond Laser: Potential Evidence for no Produced by Two Distinct Channels.

    Science.gov (United States)

    Lue, Christopher J.; Tanjaroon, Chakree; Johnson, J. Bruce; Reeve, Scott W.; Allen, Susan D.

    2013-06-01

    Upon absorption of a UV photon, nitrobenzene can dissociate into C_6H_5O and NO through two different mechanisms. Evidence for these mechanisms was obtained from velocity map imaging (VMI) studies and theoretical calculations. VMI experiments showed NO produced with two distinct rotational distributions, which the calculations explained as a fast and a slow channel for NO production. We have recorded high resolution fluorescence excitation spectra of the NO resulting from photo-fragmented nitrobenzene using a pulsed picosecond tunable laser (pulse width ≈ 15 ps) by means of a two-color process. In the two-color process, photons of a particular energy dissociated the nitrobenzene while photons of a different energy probed the A^2Σ^+← X^2Π_{(1/2,3/2)} NO band system between 225-260 nm. This laser system allowed us to vary the delay between the photolysis and excitation pulses. At longer delays (>1 ns), we observed an increase in the population of NO, which may be evidence that at least two photolysis channels produce NO. We present the spectra we recorded at various photolysis/probe delays ranging from 0.025 to 1.5 ns. The spectral subtraction method we used to observe the production increase is introduced. Hause, M. L.; Herath, N.; Zhu, R.; Lin, M. C. and Suits, A. G. Nat Chem, Nature Publishing Group, 2011, 3, 932-937

  14. The significance of numerical coincidences in nature

    CERN Document Server

    Carter, Brandon

    2007-01-01

    This is the first part of a survey whose ultimate purpose is to clarify the significance of the famous coincidence between the Hubble age of the universe and a certain combination of microphysical parameters. In this part the way is prepared by a discussion of the manner in which familiar local phenomena depend qualitatively, and in order of magnitude, quantitatively on the fundamental parameters of microphysics. In order to keep the account concise while remaining self contained, only the barest essentials of the standard nuclear physical and astrophysical calculations involved are given. Only six of the fundamental parameters play a dominant part, namely the coupling constants of the strong, electromagnetic, and gravitational forces, and the mass ratios of the proton, neutron, electron and pi-meson. Attention is drawn to the important consequences of three coincidental relationships between these parameters. It is shown that most of the principle limiting masses of astrophysics arise (in fundamental units) ...

  15. Maximum information with minimum complexity from a coincidence assay system

    International Nuclear Information System (INIS)

    There are nuclear based assay situations where measurement of coincident radiation is possible and also appropriate because the coincidence requirement serves to decrease background and moreover may be particularly characteristic of the material being assayed. In these cases, besides the basic coincidence response, the coincidence system can be made to furnish additional useful information, to reduce the sensitivity of the measurement to detection efficiency, provide a continuous test of system performance, and in some instances, signal the presence of environmental noise or nuclear interferences. This paper discusses this coincidence system further. 3 refs., 1 fig

  16. Near Threshold Coincident Electrofission of Uranium -238.

    Science.gov (United States)

    Dowell, David Harry

    Using the 100% duty cycle electron beam from the University of Illinois MUSL-2 accelerator, inelastic electron scattering form factors have been measured in coincidence with the fission decay of ('238)U. Data was taken at effective elastic momentum transfers of .36, .41 .45 and .59 fm(' -1) and electron-fission fragment angular correlations were measured perpendicular to and along the momentum transfer axis. The beam energies used were 67.11, 56.91 and 46.49 MeV, with the outgoing electron detected at 60(DEGREES) and 80(DEGREES), relative to the beam direction. The electron energy resolution was .1% and the form factors were measured for excitation energies from 2 to 12 MeV. Thin films of scintillator plastic (.5 mg/cm('2)) were used to detect the fission fragments from a 1 mg/cm('2) UF(,4) target evaporated onto a .240 mg/cm('2) aluminum backing. A prominent, anisotropic threshold peak is seen in the coincident form factors. An analysis of the q-dependence of the data and of the angular correlation indicates the observed strength is E2. Fission threshold for this E2 strength is about 5.7 MeV as compared with 6 MeV for E1 decays. The peak itself is due to the onset of neutron competition at 6.15 MeV. The threshold region, when analyzed using a Gaussian K-distribution to describe the statistical density of K -states near the fission barrier, exhibits a step-like change in the value of K(,0)('2) at .7 MeV above threshold. This indicates a possible energy gap in the E2 transition states. The decay is isotropic above 7.5 MeV excitation energy. From 7 to 11.7 MeV, the distribution of E2/EO strength is relatively flat with the total strength in this region exhausting approximately 10% of an energy weighted sum rule. A comparison with hadron scattering experiments suggests that some of the strength near 11.5 MeV is due to the fission decay of the giant monopole resonance with a fission probability similar to that of E2 transitions.

  17. The model JSR-12 neutron coincidence analyzer

    International Nuclear Information System (INIS)

    This paper reports that one of the ways in which non-destructive assays for nuclear materials is made involved counting the neutron signatures which result from spontaneous or induced fissions in fissile materials. A major problem in determining the number of fission neutrons is trying to separate them from the background of neutrons arising from alpha particle interactions with lighter nuclei in the matrix materials of the samples being assayed. The JSR-12 neutron coincidence analyzer operates on the principle that fission neutrons occur in multiples of two or more, whereas background neutrons occur randomly as single events. By exploiting this time correlation difference, the JSR-12 can determine the fission neutron signal. This instrument represents a considerable upgrade from the industry standard JSR-11, by doubling the response speed and adding complete computer control of all functions, as well as employing non-volatile memory for data storage. Operation has been simplified for field use by using an LCD display to guide the operator in setting up assay parameters, and by time-date tagging all assays for later retrieval

  18. Complex Action Support from Coincidences of Couplings

    CERN Document Server

    Nielsen, Holger Bech

    2011-01-01

    The model of Ninomiya and myself of complex action in a functional integral formulation interpreted by means of path integrals extending over all times, both past and future, is reviewed. A few numerical relations between coupling constants and masses are taken as supporting evidences. The new one such supporting ev- idence among the mentioned "coincidences" is that our model is able to explain (suggestively) that a) the Higgs field expectation value is very small ("scale problem") compared to say some fundamental scale that might be the Planck scale, b) This Higgs VEV scale need not be just zero, but rather is predicted to be so that the running top-quark Yukawa coupling just is about unity at this scale. In this way it is easily becoming an "exponentially" small scale. Instead of the top-Yukawa we should rather here say the highest flavour Yukawa coupling. These predictions are only achieved by allowing the principle of minimization of the imaginary part of the action SI(history) to to a certain extent adju...

  19. New insight into dissociative photoionization of N2O at ∼20 eV using threshold photoelectron–photoion coincidence velocity imaging

    International Nuclear Information System (INIS)

    Highlights: • The unknown D2Π state was confessedly identified in threshold photoelectron spectrum of N2O at ∼20 eV. • Kinetic energy distributions of NO+ fragments dissociated from D2Π and C2Σ+ states were observed very similar. • Dissociation mechanisms of N2O+ in D2Π(v2+) and C2Σ+(0,0,0) states were proposed respectively. - Abstract: Dissociative photoionization (DPI) of N2O at ∼20 eV has been reinvestigated with threshold photoelectron–photoion coincidence (TPEPICO) velocity imaging. In threshold photoelectron spectrum, a shoulder peak at 20.045 eV is observed close to the ground vibrational level of C2Σ+ state at 20.100 eV. Through comparing the coincident mass spectra recorded at 20.045 and 20.100 eV, the assignment of the shoulder band is corrected to a vibrational excited D2Π ionic state from the previous conclusions of the vibrationless level of b4Π or hot band of C2Σ+ state. For the dominant photofragment of NO+ at 20.045 eV, TPEPICO time-sliced velocity image is measured to obtain the corresponding total kinetic energy and angular distributions. Interestingly, both the bimodal vibrational population and angular distribution of NO+ fragment from dissociation of N2O+(D2Π) are very similar to those of N2O+(C2Σ+) ions. With the aid of potential energy curves, the DPI mechanisms of N2O via D2Π ionic state at 20.045 eV along the NO+(X1Σ+) + N(2D) and NO+(X1Σ+) + N(2P) dissociation channels are clarified, in which the internal conversion from D2Π to B2Π state is the rate-determined step

  20. Neutron coincidence counting with digital signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Bagi, Janos [Institute of Isotopes (IKI)-Budapest (Hungary); Dechamp, Luc; Dransart, Pascal; Dzbikowicz, Zdzislaw [European Commission, Joint Research Centre, IPSC-Ispra, VA (Italy); Dufour, Jean-Luc [Institut de Radioprotection et Surete Nucleaire-Fontenay-aux-Roses (France); Holzleitner, Ludwig [European Commission, Joint Research Centre, IPSC-Ispra (Italy); Huszti, Joseph [Institute of Isotopes (IKI)-Budapest (Hungary); Looman, Marc [Consulenze Tecniche-Cocquio Trevisago (Italy); Marin Ferrer, Montserrat [European Commission, Joint Research Centre, IPSC-Ispra (Italy); Lambert, Thierry [Institut de Radioprotection et Surete Nucleaire-Fontenay-aux-Roses (France); Peerani, Paolo [European Commission, Joint Research Centre, IPSC-Ispra (Italy)], E-mail: paolo.peerani@jrc.it; Rackham, Jamie [VT Nuclear Services-Sellafield, Seascale (United Kingdom); Swinhoe, Martyn; Tobin, Steve [N-1, Safeguards Science and Technology Group, LANL-Los Alamos, NM (United States); Weber, Anne-Laure [Institut de Radioprotection et Surete Nucleaire-Fontenay-aux-Roses (France); Wilson, Mark [VT Nuclear Services-Sellafield, Seascale (United Kingdom)

    2009-09-11

    Neutron coincidence counting is a widely adopted nondestructive assay (NDA) technique used in nuclear safeguards to measure the mass of nuclear material in samples. Nowadays, most neutron-counting systems are based on the original-shift-register technology, like the (ordinary or multiplicity) Shift-Register Analyser. The analogue signal from the He-3 tubes is processed by an amplifier/single channel analyser (SCA) producing a train of TTL pulses that are fed into an electronic unit that performs the time- correlation analysis. Following the suggestion of the main inspection authorities (IAEA, Euratom and the French Ministry of Industry), several research laboratories have started to study and develop prototypes of neutron-counting systems with PC-based processing. Collaboration in this field among JRC, IRSN and LANL has been established within the framework of the ESARDA-NDA working group. Joint testing campaigns have been performed in the JRC PERLA laboratory, using different equipment provided by the three partners. One area of development is the use of high-speed PCs and pulse acquisition electronics that provide a time stamp (LIST-Mode Acquisition) for every digital pulse. The time stamp data can be processed directly during acquisition or saved on a hard disk. The latter method has the advantage that measurement data can be analysed with different values for parameters like predelay and gate width, without repeating the acquisition. Other useful diagnostic information, such as die-away time and dead time, can also be extracted from this stored data. A second area is the development of 'virtual instruments.' These devices, in which the pulse-processing system can be embedded in the neutron counter itself and sends counting data to a PC, can give increased data-acquisition speeds. Either or both of these developments could give rise to the next generation of instrumentation for improved practical neutron-correlation measurements. The paper will

  1. Bell's inequality and the coincidence-time loophole

    OpenAIRE

    Larssons, JA; Gill, RD Richard

    2003-01-01

    This paper analyzes effects of time-dependence in the Bell inequality. A generalized inequality is derived for the case when coincidence and non-coincidence [and hence whether or not a pair contributes to the actual data] is controlled by timing that depends on the detector settings. Needless to say, this inequality is violated by quantum mechanics and could be violated by experimental data provided that the loss of measurement pairs through failure of coincidence is small enough, but the qua...

  2. Absolute standardization of 106Ru by anti-coincidence method

    International Nuclear Information System (INIS)

    The system of absolute standardization activity of radionuclide by anti-coincidence counting and live-time techniques was implemented at LNMRI in 2008 to reduce the impacts of some influence factors in the determination of the activity with coincidence counting technique used for decades in the lab, for example, the measurement time. With the anti-coincidence system, the variety of radionuclides that can be calibrated by LNMRI was increased, in relation to the type of decay. The objective of this work is the standardization of 106Ru by the method of counting anti-coincidence and estimate its measurement uncertainties. (author)

  3. Maximum information with minimum complexity from a coincidence assay system

    International Nuclear Information System (INIS)

    Nuclear assays based on coincidence measurements can yield more useful information than is usually derived from them. The additional information can be used to improve assay accuracy and reliability with only a modest increase in the complexity of the electronics. A particular three-channel coincidence system that has had practical application is analyzed as an example. (author)

  4. Novel Beta-Gamma Coincidence Measurements Using Phoswich Detectors

    International Nuclear Information System (INIS)

    The PNNL has developed an Automated Radio-xenon Sampler/Analyzer (ARSA) for the CTBT to measure four radio-xenon isotopes using a beta-gamma coincidence counting detector. A novel method to measure beta-gamma coincidences using a phoswich detector with state-of-the-art pulse shape discrimination techniques has been investigated

  5. Coincidence Prompt Gamma-Ray Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    R.P. gandner; C.W. Mayo; W.A. Metwally; W. Zhang; W. Guo; A. Shehata

    2002-11-10

    The normal prompt gamma-ray neutron activation analysis for either bulk or small beam samples inherently has a small signal-to-noise (S/N) ratio due primarily to the neutron source being present while the sample signal is being obtained. Coincidence counting offers the possibility of greatly reducing or eliminating the noise generated by the neutron source. The present report presents our results to date on implementing the coincidence counting PGNAA approach. We conclude that coincidence PGNAA yields: (1) a larger signal-to-noise (S/N) ratio, (2) more information (and therefore better accuracy) from essentially the same experiment when sophisticated coincidence electronics are used that can yield singles and coincidences simultaneously, and (3) a reduced (one or two orders of magnitude) signal from essentially the same experiment. In future work we will concentrate on: (1) modifying the existing CEARPGS Monte Carlo code to incorporate coincidence counting, (2) obtaining coincidence schemes for 18 or 20 of the common elements in coal and cement, and (3) optimizing the design of a PGNAA coincidence system for the bulk analysis of coal.

  6. Recovery and normalization of triple coincidences in PET

    Energy Technology Data Exchange (ETDEWEB)

    Lage, Eduardo, E-mail: elage@mit.edu; Parot, Vicente; Dave, Shivang R.; Herraiz, Joaquin L. [Madrid-MIT M+Visión Consortium, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Moore, Stephen C.; Sitek, Arkadiusz; Park, Mi-Ae [Division of Nuclear Medicine, Department of Radiology, Harvard Medical School and Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Udías, Jose M. [Grupo de Física Nuclear, Departamento de Física Atómica Molecular y Nuclear, Universidad Complutense de Madrid, CEI Moncloa, Madrid 28040 (Spain); Vaquero, Juan J. [Departamento de Ingeniería Biomédica e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Leganés 28911 (Spain)

    2015-03-15

    Purpose: Triple coincidences in positron emission tomography (PET) are events in which three γ-rays are detected simultaneously. These events, though potentially useful for enhancing the sensitivity of PET scanners, are discarded or processed without special consideration in current systems, because there is not a clear criterion for assigning them to a unique line-of-response (LOR). Methods proposed for recovering such events usually rely on the use of highly specialized detection systems, hampering general adoption, and/or are based on Compton-scatter kinematics and, consequently, are limited in accuracy by the energy resolution of standard PET detectors. In this work, the authors propose a simple and general solution for recovering triple coincidences, which does not require specialized detectors or additional energy resolution requirements. Methods: To recover triple coincidences, the authors’ method distributes such events among their possible LORs using the relative proportions of double coincidences in these LORs. The authors show analytically that this assignment scheme represents the maximum-likelihood solution for the triple-coincidence distribution problem. The PET component of a preclinical PET/CT scanner was adapted to enable the acquisition and processing of triple coincidences. Since the efficiencies for detecting double and triple events were found to be different throughout the scanner field-of-view, a normalization procedure specific for triple coincidences was also developed. The effect of including triple coincidences using their method was compared against the cases of equally weighting the triples among their possible LORs and discarding all the triple events. The authors used as figures of merit for this comparison sensitivity, noise-equivalent count (NEC) rates and image quality calculated as described in the NEMA NU-4 protocol for the assessment of preclinical PET scanners. Results: The addition of triple-coincidence events with the

  7. Recovery and normalization of triple coincidences in PET

    International Nuclear Information System (INIS)

    Purpose: Triple coincidences in positron emission tomography (PET) are events in which three γ-rays are detected simultaneously. These events, though potentially useful for enhancing the sensitivity of PET scanners, are discarded or processed without special consideration in current systems, because there is not a clear criterion for assigning them to a unique line-of-response (LOR). Methods proposed for recovering such events usually rely on the use of highly specialized detection systems, hampering general adoption, and/or are based on Compton-scatter kinematics and, consequently, are limited in accuracy by the energy resolution of standard PET detectors. In this work, the authors propose a simple and general solution for recovering triple coincidences, which does not require specialized detectors or additional energy resolution requirements. Methods: To recover triple coincidences, the authors’ method distributes such events among their possible LORs using the relative proportions of double coincidences in these LORs. The authors show analytically that this assignment scheme represents the maximum-likelihood solution for the triple-coincidence distribution problem. The PET component of a preclinical PET/CT scanner was adapted to enable the acquisition and processing of triple coincidences. Since the efficiencies for detecting double and triple events were found to be different throughout the scanner field-of-view, a normalization procedure specific for triple coincidences was also developed. The effect of including triple coincidences using their method was compared against the cases of equally weighting the triples among their possible LORs and discarding all the triple events. The authors used as figures of merit for this comparison sensitivity, noise-equivalent count (NEC) rates and image quality calculated as described in the NEMA NU-4 protocol for the assessment of preclinical PET scanners. Results: The addition of triple-coincidence events with the

  8. High rate 4. pi. beta. -. gamma. coincidence counting system

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L.O.; Gehrke, R.J.

    1978-01-01

    A high count rate 4..pi.. ..beta..-..gamma.. coincidence counting system for the determination of absolute disintegration rates of short half-life radionuclides is described. With this system the dead time per pulse is minimized by not stretching any pulses beyond the width necessary to satisfy overlap coincidence requirements. The equations used to correct for the ..beta.., ..gamma.., and coincidence channel dead times and for accidental coincidences are presented but not rigorously developed. Experimental results are presented for a decaying source of /sup 56/Mn initially at 2 x 10/sup 6/ d/s and a set of /sup 60/Co sources of accurately known source strengths varying from 10/sup 3/ to 2 x 10/sup 6/ d/s. A check of the accidental coincidence equation for the case of two independent sources with varying source strengths is presented.

  9. Roles for Coincidence Detection in Coding Amplitude-Modulated Sounds

    Science.gov (United States)

    Ashida, Go; Kretzberg, Jutta; Tollin, Daniel J.

    2016-01-01

    Many sensory neurons encode temporal information by detecting coincident arrivals of synaptic inputs. In the mammalian auditory brainstem, binaural neurons of the medial superior olive (MSO) are known to act as coincidence detectors, whereas in the lateral superior olive (LSO) roles of coincidence detection have remained unclear. LSO neurons receive excitatory and inhibitory inputs driven by ipsilateral and contralateral acoustic stimuli, respectively, and vary their output spike rates according to interaural level differences. In addition, LSO neurons are also sensitive to binaural phase differences of low-frequency tones and envelopes of amplitude-modulated (AM) sounds. Previous physiological recordings in vivo found considerable variations in monaural AM-tuning across neurons. To investigate the underlying mechanisms of the observed temporal tuning properties of LSO and their sources of variability, we used a simple coincidence counting model and examined how specific parameters of coincidence detection affect monaural and binaural AM coding. Spike rates and phase-locking of evoked excitatory and spontaneous inhibitory inputs had only minor effects on LSO output to monaural AM inputs. In contrast, the coincidence threshold of the model neuron affected both the overall spike rates and the half-peak positions of the AM-tuning curve, whereas the width of the coincidence window merely influenced the output spike rates. The duration of the refractory period affected only the low-frequency portion of the monaural AM-tuning curve. Unlike monaural AM coding, temporal factors, such as the coincidence window and the effective duration of inhibition, played a major role in determining the trough positions of simulated binaural phase-response curves. In addition, empirically-observed level-dependence of binaural phase-coding was reproduced in the framework of our minimalistic coincidence counting model. These modeling results suggest that coincidence detection of excitatory

  10. Light particles emitted in coincidence with evaporation residues in {sup 79}Br(930 MeV) + {sup 27}Al collisions

    Energy Technology Data Exchange (ETDEWEB)

    Chavez Lomeli, E.; Dacal, A.; Ortiz, M.E. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica; D`Onofrio, A. [Istituto Nazionale di Fisica Nucleare, Naples (Italy); Gomez del Campo, J.; Kim, H.; Korolija, M.; Shapira, D. [Oak Ridge National Lab., TN (United States)

    1993-10-01

    Exclusive measurements of light particles, deuterons, tritons and alphas, in coincidence with Evaporation Residues (ER), were performed at the Holified Heavy Ion Research Facility of the Oak Ridge National Laboratory using the large detector array HILI (Heavy Ion Light Ion). Heavy fragments produced in the reaction (Z 35), were stopped in the Ionisation Chamber, where their energy, atomic number (Z) and position were measured. Coincident light particles, were detected in the 192 element hodoscope placed behind the chamber, where its charge (Z) and energy were measured. Also the time of flight relative to the radio frequency of the cyclotron, allowed identification of protons deuterons and tritons.

  11. Why Do Deconfinement and Chiral Restoration Coincide at High Temperature?

    Institute of Scientific and Technical Information of China (English)

    杨树; 郭华; 赵恩广; 吕晓夫

    2004-01-01

    The global colour model in free space is extended to finite temperature to study the deconfinement and chiral phase transitions at high temperature T and zero chemical potential in the mean field approximation. Both possibilities of coincidence and non-coincidence of the two distinct phase transitions are found when the model parameters are varied in a certain range. The underlying mechanisms of the coincidence and noncoincidence are analysed and discussed. The validity of the T-dependent model propagator as the input is also discussed.

  12. A coincidence counting system for detection of low level activities

    International Nuclear Information System (INIS)

    A system based on coincidence counting for measuring the absolute activity of isotopes in which a gamma ray is emitted by the nucleus following the capture of the orbital electron with a known half-life is described. If the half-life of the excited state is small compared to the resolving time of the coincidence circuit, the absolute activity of the source can be determined. The system consists of two NaI(Th) crystals, a high voltage supply, 2 preamplifiers, 2 amplifiers, two single channel analyzers, one coincident unit, and three sealers

  13. Low-resource synchronous coincidence processor for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sportelli, Giancarlo, E-mail: gsportelli@die.upm.es [Biomedical Image Technologies, E.T.S.I.T., Universidad Politecnica de Madrid, 28040 Madrid (Spain); Research Center in Bioengineering, Biomaterials and Nanomedicine, 50018 Zaragoza (Spain); Belcari, Nicola [Department of Physics ' E. Fermi' , Universita di Pisa, 56127 Pisa (Italy); Guerra, Pedro [Research Center in Bioengineering, Biomaterials and Nanomedicine, 50018 Zaragoza (Spain); Santos, Andres [Biomedical Image Technologies, E.T.S.I.T., Universidad Politecnica de Madrid, 28040 Madrid (Spain); Research Center in Bioengineering, Biomaterials and Nanomedicine, 50018 Zaragoza (Spain)

    2011-08-21

    We developed a new FPGA-based method for coincidence detection in positron emission tomography. The method requires low device resources and no specific peripherals in order to resolve coincident digital pulses within a time window of a few nanoseconds. This method has been validated with a low-end Xilinx Spartan-3E and provided coincidence resolutions lower than 6 ns. This resolution depends directly on the signal propagation properties of the target device and the maximum available clock frequency, therefore it is expected to improve considerably on higher-end FPGAs.

  14. Fluorescent atom coincidence spectroscopy of extremely neutron-deficient barium isotopes

    International Nuclear Information System (INIS)

    Fluorescent atom coincidence spectroscopy (FACS) has been used to measure the nuclear mean square radii and moments of the extremely neutron-deficient isotopes 120-124Ba. At N=65 an abrupt change in nuclear mean square charge radii is observed which can be understood in terms of the occupation of the spin-orbit partner g7/2 5/2[413] neutron and g9/2 9/2[404] proton orbitals and the consequent enhancement of the n-p interaction. (orig.)

  15. Standardization of 18F by digital coincidence counting

    International Nuclear Information System (INIS)

    The radioactivity of 18F has been measured by a digital coincidence counting (DCC) system. The main advantages of the digital coincidence counting technique are a shortening of the measurement time as compared with conventional coincidence counting and an ability to obtain activities with various experimental parameters through off-line analysis. The measurement results of radioactivity for 18F solution were compared with those of a conventional coincidence counting technique and a reference ion chamber method. - Highlights: ► Radioactivity of F-18 is measured by a DCC technique. ► DCC technique has an advantage for the radionuclide with short half-life. ► Activity results show a good agreement with those of other methods.

  16. Mass measurement of depleted uranium components with coincidence neutron count

    International Nuclear Information System (INIS)

    The technique of the mass measurement of depleted uranium components was studied with active and passive coincidence neutron count. A well neutron coincidence counter was used to measure the coincidence neutron counts of the depleted uranium components with various mass. Am-Be source was selected as the external neutron source for induced fission in the active measurement, and a shield was optimized to reduce the accidental coincidence counts. In the active measurement, the maximum relative deviation of the linear fit mass from the nominal mass of the depleted uranium components is 11.71%, compared to 4.05% in the passive measurement. It is proved that because of the weakening of the shape influence, the passive method is more accurate and reliable to measure the mass of depleted uranium components than the active method. (authors)

  17. Computed neutron coincidence counting applied to passive waste assay

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, M.; Baeten, P.; De Boeck, W.; Carchon, R. [Nuclear Research Centre, Mol (Belgium)

    1997-11-01

    Neutron coincidence counting applied for the passive assay of fissile material is generally realised with dedicated electronic circuits. This paper presents a software based neutron coincidence counting method with data acquisition via a commercial PC-based Time Interval Analyser (TIA). The TIA is used to measure and record all time intervals between successive pulses in the pulse train up to count-rates of 2 Mpulses/s. Software modules are then used to compute the coincidence count-rates and multiplicity related data. This computed neutron coincidence counting (CNCC) offers full access to all the time information contained in the pulse train. This paper will mainly concentrate on the application and advantages of CNCC for the non-destructive assay of waste. An advanced multiplicity selective Rossi-alpha method is presented and its implementation via CNCC demonstrated. 13 refs., 4 figs., 2 tabs.

  18. Computed neutron coincidence counting applied to passive waste assay

    International Nuclear Information System (INIS)

    Neutron coincidence counting applied for the passive assay of fissile material is generally realised with dedicated electronic circuits. This paper presents a software based neutron coincidence counting method with data acquisition via a commercial PC-based Time Interval Analyser (TIA). The TIA is used to measure and record all time intervals between successive pulses in the pulse train up to count-rates of 2 Mpulses/s. Software modules are then used to compute the coincidence count-rates and multiplicity related data. This computed neutron coincidence counting (CNCC) offers full access to all the time information contained in the pulse train. This paper will mainly concentrate on the application and advantages of CNCC for the non-destructive assay of waste. An advanced multiplicity selective Rossi-alpha method is presented and its implementation via CNCC demonstrated. 13 refs., 4 figs., 2 tabs

  19. Coincidence of Schur Multipliers of the Drury-Arveson Space

    CERN Document Server

    Bhattacharya, Angshuman

    2009-01-01

    In a purely multi-variable setting (i.e., the issues discussed in this note are not interesting in the single variable operator theory setting), we show that the coincidence of two operator valued Schur class multipliers of a certain kind on the Drury-Arveson space is characterized by the fact that the associated colligations (or a variant, obtained canonically) are `unitarily coincident' in a sense to be made precise in the last section of this article.

  20. Configuration-like spaces and coincidences of maps on orbits

    CERN Document Server

    Karasev, R N

    2009-01-01

    In this paper the spaces of $q$-tuples of points in a Euclidean space, without $k$-wise coincidences are studied (configuration-like spaces). A transitive group action by permuting these points is considered, and some new upper bounds on the genus (in the sense of Krasnosel'skii-Schwarz and Clapp-Puppe) for this action are given. Some theorems of Cohen-Lusk type for coincidence points of continuous maps to Euclidean spaces are deduced.

  1. Coincidence rotations of the root lattice $A_4$

    CERN Document Server

    Baake, Michael; Heuer, Manuela; Zeiner, Peter

    2007-01-01

    The coincidence site lattices of the root lattice $A_4$ are considered, and the statistics of the corresponding coincidence rotations according to their indices is expressed in terms of a Dirichlet series generating function. This is possible via an embedding of $A_4$ into the icosian ring with its rich arithmetic structure, which recently (arXiv:math.MG/0702448) led to the classification of the similar sublattices of $A_4$.

  2. The Anti-Coincidence Detector for the GLAST Large Area Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Moiseev, A.A.; Hartman, R.C.; Ormes, J.F.; Thompson, D.J.; Amato, M.J.; Johnson, T.E.; Segal, K.N.; Sheppard, D.A.

    2007-03-23

    This paper describes the design, fabrication and testing of the Anti-Coincidence Detector (ACD) for the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT). The ACD is LAT's first-level defense against the charged cosmic ray background that outnumbers the gamma rays by 3-5 orders of magnitude. The ACD covers the top and 4 sides of the LAT tracking detector, requiring a total active area of {approx}8.3 square meters. The ACD detector utilizes plastic scintillator tiles with wave-length shifting fiber readout. In order to suppress self-veto by shower particles at high gamma-ray energies, the ACD is segmented into 89 tiles of different sizes. The overall ACD efficiency for detection of singly charged relativistic particles entering the tracking detector from the top or sides of the LAT exceeds the required 0.9997.

  3. Performance of the Anti-Coincidence Detector on the GLAST Large Area Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, D.J.; /NASA, Goddard; Charles, E.; /SLAC; Hartman, R.C.; /NASA, Goddard; Moiseev, A.A.; /NASA, Goddard; Ormes, J.F.; /NASA, Goddard /Denver U.

    2007-10-22

    The Anti-Coincidence Detector (ACD), the outermost detector layer in the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT), is designed to detect and veto incident cosmic ray charged particles, which outnumber cosmic gamma rays by 3-4 orders of magnitude. The challenge in ACD design is that it must have high (0.9997) detection efficiency for singly-charged relativistic particles, but must also have a low probability for self-veto of high-energy gammas by backsplash radiation from interactions in the LAT calorimeter. Simulations and tests demonstrate that the ACD meets its design requirements. The performance of the ACD has remained stable through stand-alone environmental testing, shipment across the U.S., installation onto the LAT, shipment back across the U.S., LAT environmental testing, and shipment to Arizona. As part of the fully-assembled GLAST observatory, the ACD is being readied for final testing before launch.

  4. Multiple-Coincidence Active Neutron Interrogation of Fissionable Materials

    Energy Technology Data Exchange (ETDEWEB)

    Tinsley, J.R., Hurley, J.P., Trainham, R., Keegan, R.P.

    2008-11-14

    In an extension of the Associated Particle Imaging technique that is used for the detection and imaging of hidden explosives, the present measurements use a beam of tagged 14.1 MeV neutrons in coincidence with two or more gammas to probe for the presence of fissionable materials. We have measured neutron-gamma-gamma coincidences with targets of depleted uranium, tungsten, lead, iron, and carbon and will present results that show the multiple-coincidence counting rate for the depleted uranium is substantially higher than any of the non-fissionable materials. In addition, the presence of coincidences involving delayed particle spectra provides a signature for fissionable materials that is distinct from that for non-fissionable ones. Information from the tagged neutron involved in the coincidence event is used to compute the position of the fissionable material in all three dimensions. The result is an imaging probe for fissionable materials that is compact and portable, and produces relatively low levels of background radiation. Simultaneous measurements on packages of interest for both explosives and fissionable materials are now feasible.

  5. Simultaneous, coincident 2-D ACAR and DBAR using segmented HPGe detectors incorporating sub-pixel interpolation

    Science.gov (United States)

    Williams, Christopher S.; Burggraf, Larry W.; Adamson, Paul E.; Petrosky, James C.; Oxley, Mark E.

    2010-04-01

    A three-dimensional Positron Annihilation Spectrometry System (3D PASS) for determination of 3D electron-positron (e--e+) momentum densities by measuring coincident annihilation photons was designed, constructed and characterized. 3D PASS collects a single data set including correlated photon energies and coincident photon positions which are typically collected separately by two-dimensional angular correlation of annihilation radiation (2D ACAR) and two-detector coincident Doppler broadening of annihilation radiation (CDBAR) spectrometry. 3D PASS is composed of two position-sensitive, high-purity germanium (HPGe) double-sided strip detectors (DSSD(s)) linked together by a 32-channel, 50 MHz digital electronics suite. The DSSDs data were analyzed to determine location of photon detection events using an interpolation method to achieve a spatial resolution less than the 5-mm width of the DSSDs' charge collection strips. The interpolation method relies on measuring a figure-of-merit proportional to the area of the transient charges observed on both strips directly adjacent to the charge collection strip detecting the full charge deposited by the annihilation photon. This sub-pixel resolution, corresponding to the error associated with event location within a sub-pixel was measured for both DSSDs using the approach outlined in Williams et al [1] and was on the order of ± 0.20 mm (± one-standard deviation). As a result of the sub-pixel resolution, the distance between the DSSDs and material sample was reduced by a factor of five compared to what is typically required in 2D ACAR systems was necessary to achieve 0.5-mrad angular resolution. This reduction in the system's footprint decreases attenuation of the annihilation photons in the air between the material sample and the DSSDs and increases the solid angle between the sample and the DSSDs, ultimately resulting in higher system detection efficiency. 3D PASS was characterized in the same manner comparable to state

  6. Simultaneous, coincident 2-D ACAR and DBAR using segmented HPGe detectors incorporating sub-pixel interpolation

    International Nuclear Information System (INIS)

    A three-dimensional Positron Annihilation Spectrometry System (3D PASS) for determination of 3D electron-positron (e--e+) momentum densities by measuring coincident annihilation photons was designed, constructed and characterized. 3D PASS collects a single data set including correlated photon energies and coincident photon positions which are typically collected separately by two-dimensional angular correlation of annihilation radiation (2D ACAR) and two-detector coincident Doppler broadening of annihilation radiation (CDBAR) spectrometry. 3D PASS is composed of two position-sensitive, high-purity germanium (HPGe) double-sided strip detectors (DSSD(s)) linked together by a 32-channel, 50 MHz digital electronics suite. The DSSDs data were analyzed to determine location of photon detection events using an interpolation method to achieve a spatial resolution less than the 5-mm width of the DSSDs' charge collection strips. The interpolation method relies on measuring a figure-of-merit proportional to the area of the transient charges observed on both strips directly adjacent to the charge collection strip detecting the full charge deposited by the annihilation photon. This sub-pixel resolution, corresponding to the error associated with event location within a sub-pixel was measured for both DSSDs using the approach outlined in Williams et al [1] and was on the order of ± 0.20 mm (± one-standard deviation). As a result of the sub-pixel resolution, the distance between the DSSDs and material sample was reduced by a factor of five compared to what is typically required in 2D ACAR systems was necessary to achieve 0.5-mrad angular resolution. This reduction in the system's footprint decreases attenuation of the annihilation photons in the air between the material sample and the DSSDs and increases the solid angle between the sample and the DSSDs, ultimately resulting in higher system detection efficiency. 3D PASS was characterized in the same manner comparable to state

  7. Simultaneous, coincident 2-D ACAR and DBAR using segmented HPGe detectors incorporating sub-pixel interpolation

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Christopher S; Burggraf, Larry W; Petrosky, James C; Oxley, Mark E [Air Force Institute of Technology, AFIT/ENP, 2950 Hobson Way, Wright-Patterson Air Force Base, OH 45433 (United States); Adamson, Paul E, E-mail: christopher.williams@afit.ed [High Power Microwave (HPM) Technologies Branch, HPM Division, Directed Energy Directorate, Air Force Research Laboratory, Kirtland AFB, NM 87117 (United States)

    2010-04-01

    A three-dimensional Positron Annihilation Spectrometry System (3D PASS) for determination of 3D electron-positron (e{sup -}-e{sup +}) momentum densities by measuring coincident annihilation photons was designed, constructed and characterized. 3D PASS collects a single data set including correlated photon energies and coincident photon positions which are typically collected separately by two-dimensional angular correlation of annihilation radiation (2D ACAR) and two-detector coincident Doppler broadening of annihilation radiation (CDBAR) spectrometry. 3D PASS is composed of two position-sensitive, high-purity germanium (HPGe) double-sided strip detectors (DSSD(s)) linked together by a 32-channel, 50 MHz digital electronics suite. The DSSDs data were analyzed to determine location of photon detection events using an interpolation method to achieve a spatial resolution less than the 5-mm width of the DSSDs' charge collection strips. The interpolation method relies on measuring a figure-of-merit proportional to the area of the transient charges observed on both strips directly adjacent to the charge collection strip detecting the full charge deposited by the annihilation photon. This sub-pixel resolution, corresponding to the error associated with event location within a sub-pixel was measured for both DSSDs using the approach outlined in Williams et al [1] and was on the order of {+-} 0.20 mm ({+-} one-standard deviation). As a result of the sub-pixel resolution, the distance between the DSSDs and material sample was reduced by a factor of five compared to what is typically required in 2D ACAR systems was necessary to achieve 0.5-mrad angular resolution. This reduction in the system's footprint decreases attenuation of the annihilation photons in the air between the material sample and the DSSDs and increases the solid angle between the sample and the DSSDs, ultimately resulting in higher system detection efficiency. 3D PASS was characterized in the same

  8. Control of time stability of scintillation spectrometer of delayed coincidences

    CERN Document Server

    Morozov, V A

    2002-01-01

    Paper describes a system to control time stability of a two-detector plastic scintillation spectrometer of three-dimensional coincides. A two-reference control system incorporates a light guide base delay optical line, two light diodes and a two-channel generator of nanosecond pulses. A distinguishing feature of the design system is application of one delay line to form both advance and delay time signal as to the real coincidences in the studied radioactive source. The designed system of control enables to measure periods of half-decay of nuclei excited states within 40-100 ns range ensuring control of position of coincidence curve gravity centers within 4 ps limits

  9. Performance of Boron-10 based Neutron Coincidence Counters

    International Nuclear Information System (INIS)

    Helium-3 gas-filled detectors have been used in neutron coincidence counting for non-destructive assay for over 30 years. With the current shortage of 3He gas, GE's Reuter-Stokes business developed a 10B lined proportional counter and a 10B hybrid coincidence counter, in which a small amount of 3He is added to a 10B detector to enhance the neutron sensitivity. GE's Reuter-Stokes business modelled, designed, built and tested prototype coincidence counters using the 10B lined detectors and the 10B hybrid detectors. We will present these systems and their applications for non-destructive assay. (author)

  10. Implications on the cosmic coincidence by a dynamical extrinsic curvature

    CERN Document Server

    Capistrano, A J S

    2015-01-01

    In this work, we apply the smooth deformation concept in order to obtain a modification of Friedmann equations. It is shown that the cosmic coincidence can be at least alleviated using the dynamical properties of the extrinsic curvature. We investigate the transition from nucleosynthesis to the coincidence era obtaining a very small variation of the ratio $r=\\frac{\\rho_{m}}{\\rho_{ext}}$, that compares the matter energy density to extrinsic energy density, compatible with the known behavior of the deceleration parameter. We also show that the calculated "equivalence" redshift matches the transition redshift from a deceleration to accelerated phase and the coincidence ceases to be. The dynamics on $r$ is also studied based on Hubble parameter observations as the latest Baryons Acoustic Oscillations/Cosmic Microwave Background Radiation (BAO/CMBR) + SNIa.

  11. The ZEPLIN-III Anti-Coincidence Veto Detector

    CERN Document Server

    Akimov, D Yu; Barnes, E J; Belov, V A; Burenkov, A A; Chepel, V; Currie, A; Edwards, B; Francis, V; Ghag, C; Hollingsworth, A; Horn, M; Kalmus, G E; Kobyakin, A S; Kovalenko, A G; Lebedenko, V N; Lindote, A; Lopes, M I; Lüscher, R; Lyons, K; Majewski, P; Murphy, A St J; Neves, F; Paling, S M; da Cunha, J Pinto; Preece, R; Quenby, J J; Reichhart, L; Scovell, P R; Solovov, V N; Smith, N J T; Smith, P F; Stekhanov, V N; Sumner, T J; Taylor, R; Thorne, C; Walker, R J

    2010-01-01

    The design, optimisation and construction of an anti-coincidence veto detector to complement the ZEPLIN-III direct dark matter search instrument is described. One tonne of plastic scintillator is arranged into 52 bars individually read out by photomultipliers and coupled to a gadolinium-loaded passive polypropylene shield. Particular attention has been paid to radiological content. The overall aim has been to achieve a veto detector of low threshold and high efficiency without the creation of additional background in ZEPLIN-III, all at a reasonable cost. Extensive experimental measurements of the components have been made, including radioactivity levels and performance characteristics. These have been used to inform a complete end-to-end Monte Carlo simulation that has then been used to calculate the expected performance of the new instrument, both operating alone and as an anti-coincidence detector for ZEPLIN-III. The veto device will be capable of rejecting over 65% of coincident nuclear recoil events from ...

  12. CDL, a Precise, Low-Cost Coincidence Detector Latch

    Directory of Open Access Journals (Sweden)

    Ralf Joost

    2015-12-01

    Full Text Available The electronic detection of the coincidence of two events is still a key ingredient for high-performance applications, such as Positron Emission Tomography and Quantum Optics. Such applications are demanding, since the precision of their calculations and thus their conclusions directly depend on the duration of the interval in which two events are considered coincidental. This paper proposes a new circuitry, called coincidence detector latch (CDL, which is derived from standard RS latches. The CDL has the following advantages: low complexity, fully synthesizable, and high scalability. Even in its simple implementation, it achieves a coincidence window width as short as 115 ps, which is more than 10 times better than that reported by recent research.

  13. A training and educational tool for neutron coincidence measurements

    International Nuclear Information System (INIS)

    Neutron coincidence counting techniques are widely used for nuclear safeguards inspection. They are based on the detection of time correlated neutrons created from spontaneous or induced fission of plutonium and some other actinides. IAEA inspectors are trained to know and to use this technique, but it is not easy to illustrate and explain the basics of the neutron coincidence counting. The traditional shift registers or multiplicity counters give only multiplicity distributions and the singles, doubles and triples count rates. Using the list mode method for the recording and evaluation of neutron coincidence data makes it easier to teach this technique. List mode acquisition is a relatively new way to collect data in neutron coincidence counting. It is based on the recording of the follow-up times of neutron pulses originating from a neutron detector into a file. The recorded pulse train can be evaluated with special software after the measurement. Hardware and software for list mode neutron coincidence acquisition have been developed in the Institute of Isotopes and is called a Pulse Train Reader. A system called Virtual Source for replaying pulse trains registered with the list mode device has also been developed. The list mode device and the pulse train 're-player' together build a good educational tool for teaching the basics of neutron coincidence counting. Some features of the follow-up time, multiplicity and Rossi-alpha distributions can be well demonstrated by replaying artificially generated or pre-recorded pulse trains. The choice of real sources is stored on DVD. There is no need to transport and maintain real sources for the training. Virtual sources also give the possibility of investigating rare sources that trainees would not have access to otherwise. (authors)

  14. Non-coincident multi-wavelength emission absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, L.E.

    1995-02-01

    An analysis is presented of the effect of noncoincident sampling on the measurement of atomic number density and temperature by multiwavelength emission absorption. The assumption is made that the two signals, emission and transmitted lamp, are time resolved but not coincident. The analysis demonstrates the validity of averages of such measurements despite fluctuations in temperature and optical depth. At potassium-seeded MHD conditions, the fluctuations introduce additional uncertainty into measurements of potassium atom number density and temperature but do not significantly bias the average results. Experimental measurements in the CFFF aerodynamic duct with coincident and noncoincident sampling support the analysis.

  15. Standardization of portable assay instrumentation: the neutron-coincidence tree

    International Nuclear Information System (INIS)

    Standardization of portable neutron assay instrumentation has been achieved by using the neutron coincidence technique as a common basis for a wide range of instruments and applications. The electronics originally developed for the High-Level Neutron Coincidence Counter has been adapted to both passive- and active-assay instrumentation for field verification of bulk plutonium, inventory samples, pellets, powders, nitrates, high-enriched uranium, and materials-testing-reactor, light-water-reactor, and mixed-oxide fuel assemblies. The family of detectors developed at Los Alamos National Laboratory and their performance under in-field conditions are described. 16 figures, 3 tables

  16. Determination of the time resolution for neutron scintillation detectors by multi-coincidence measurement

    Institute of Scientific and Technical Information of China (English)

    LI Yong-Ming; RUAN Xi-Chao; ZHOU Bin; MA Zhong-Yuan

    2011-01-01

    Based on the multi-coincidence measurement, the time resolution of three liquid scintillation detectors (BC501A) were determined strictly by solving the coincidence equations, where the influence from electronics estimated by self coincidence measurement

  17. AdS/CFT correspondence and coincident D-6-branes

    OpenAIRE

    Ketov, Sergei V.

    1998-01-01

    A relation between confinement and Maldacena conjecture is briefly discussed. The gauge symmetry enhancement for two coincident D-6-branes is analyzed from the viewpoint of the hypermultiplet low-energy effective action given by the N=2 supersymmetric non-linear sigma-model with the Eguchi-Hanson (ALE) target space.

  18. 4. pi beta. -. gamma. coincidence system with minimally broadened pulses

    Energy Technology Data Exchange (ETDEWEB)

    Gehrke, R.J.; Johnson, L.O. (Idaho National Engineering Lab., Idaho Falls (USA))

    1982-12-15

    The performance characteristics of a new type 4..pi.. ..beta..-..gamma.. coincidence system have been measured. In contrast with the conventional 4..pi.. ..beta..-..gamma.. circuitry, which is based on a fixed pulse width (approx.= 2 ..mu..s) and a non-extendable dead time, the pulse processing circuitry in this new system is based on a minimally broadened pulse (i.e., as narrow as 0.25 ..mu..s). In this system each pulse has a different pulse width, so that the dead times for the ..beta..- and ..gamma..-ray detectors are determined by summing the measured dead time attributed by each pulse in each channel. The ..beta..-..gamma.. coincidences are defined with an overlap coincidence circuit. This system is shown to be much less sensitive to mismatch in the coincidence timing than is the conventional system. In spite of the narrower pulse widths, no spurious ..beta.. pulses are observed when the 4..pi.. proportional counter is operated near the center of its plateau. Disintegration rates were measured for calibrated sources with strength up to approx.= 10/sup 6/ Bq. These data indicate that with this new system the disintegration rates of very intense sources (approx.= 10/sup 6/ Bq) and moderately intense sources (< 10/sup 5/ Bq) can be determined with accuracies of approx.= 4% and <= 0.1%, respectively.

  19. Application of coincidence techniques to fusion product measurements

    International Nuclear Information System (INIS)

    Measurement of two products of a fusion reaction in coincidence is proposed. Possible detector arrays and sample count rates have been evaluated for reactions in the TFR and TEXT tokamaks and in the TFTR neutral beamlines. The count rates indicate that this method is feasible on existing devices

  20. Reduction of geometry and matrix effects by fast coincidence NDA

    International Nuclear Information System (INIS)

    Fast coincidence techniques based on detection of fissions are often used to passively or actively assay SNM. Several commercial instruments based on these techniques have been available since the early Seventies: ISAS, ISAF, and Random Driver. These techniques offer high sensitivities to SMM. They are applicable to small, as well as large size containers, e.g., 55 gallon drums. Like other NDA techniques, geometrical and matrix effects can have large contributions to the measurement error. However, algebraic combinations of coincidence multiplicities can be formed which are relatively independent of detection efficiency, yet proportional to the amount of nuclear material being assayed. Considering these combinations, in addition to the coincidence rates alone as fission signatures, has the demonstrable advantage that the assay results are comparatively independent of sample geometry or even matrix. Systematic measurements to assess the degree of reduction of matrix and geometrical effects and its limitation were recently completed. The measurement results show that coincidence ratios, and most specifically, twoto three-fold ratio, reduce matrix and geometrical effects. The effect of polyethylene and sand on the standard signal was reduced by a factor of two to three. Spatial effects were reduced by 50-80%. Non-linearity, i.e., variation in signal per gram U, for a soft neutron spectrum was reduced by 20-30%, with small loss of sensitivity

  1. Decay pathways after Xe 3d inner shell ionization using a multi-electron coincidence technique

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, I H; Nakano, M; Ito, K [Photon Factory, IMSS, KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Hikosaka, Y; Soejima, K [Department of Environmental Science, Niigata University, Niigata 950-2181 (Japan); Shigemasa, E [UVSOR Facility, Institute for Molecular Science, Okazaki, 444-8585 (Japan); Lablanquie, P; Penent, F [UPMC, Universite Paris 06, LCPMR, 11 rue de Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Kouchi, N, E-mail: suzukii@post.kek.jp [Department of Chemistry, Tokyo Institute of Technology, O-okayama, Tokyo 152-8551 (Japan)

    2011-04-14

    Cascade Auger electron emission following Xe 3d photoionization has been investigated using a multi-electron coincidence technique, which utilizes an electron spectrometer of magnetic bottle type. It has been found that the Xe{sup 2+} states of the 4p{sup -1}4d{sup -1} configuration, formed by the Auger decay of the Xe{sup +} 3d{sub 3/2,5/2}{sup -1} states, dominantly turn into triply charged states of the 4d{sup -2}5p{sup -1}/4d{sup -2}5s{sup -1} configurations. The Xe{sup 2+} 4s{sup -1}4d{sup -1} states, formed by the 3d Auger decay, yield the 4p{sup -1}4d{sup -1}5p{sup -1} states as well as the 4d{sup -3} states. From the coincidence spectrum among three Auger electrons, it is suggested that the Xe{sup 2+} 4p{sup -1}4d{sup -1} states give rise to the following cascade processes: 4p{sup -1}4d{sup -1} {yields} 4d{sup -2}5p{sup -1} {yields} 4d{sup -1}5p{sup -3}.

  2. Design of a coincidence processing board for a dual-head PET scanner for breast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, J.D. [Departamento de Ingenieria Electronica, University Politecnica de Valencia, Camino de Vera s/n 46022, Valencia (Spain)]. E-mail: jormarp1@doctor.upv.es; Toledo, J. [Departamento de Ingenieria Electronica, University Politecnica de Valencia, Camino de Vera s/n 46022, Valencia (Spain); Esteve, R. [Departamento de Ingenieria Electronica, University Politecnica de Valencia, Camino de Vera s/n 46022, Valencia (Spain); Sebastia, A. [Departamento de Ingenieria Electronica, University Politecnica de Valencia, Camino de Vera s/n 46022, Valencia (Spain); Mora, F.J. [Departamento de Ingenieria Electronica, University Politecnica de Valencia, Camino de Vera s/n 46022, Valencia (Spain); Benlloch, J.M. [Instituto de Fisica Corpuscular, CSIC-UV, Valencia (Spain); Fernandez, M.M. [Instituto de Fisica Corpuscular, CSIC-UV, Valencia (Spain); Gimenez, M. [Instituto de Fisica Corpuscular, CSIC-UV, Valencia (Spain); Gimenez, E.N. [Instituto de Fisica Corpuscular, CSIC-UV, Valencia (Spain); Lerche, Ch.W. [Instituto de Fisica Corpuscular, CSIC-UV, Valencia (Spain); Pavon, N. [Instituto de Fisica Corpuscular, CSIC-UV, Valencia (Spain); Sanchez, F. [Instituto de Fisica Corpuscular, CSIC-UV, Valencia (Spain)

    2005-07-01

    This paper describes the design of a coincidence processing board for a dual-head Positron Emission Tomography (PET) scanner for breast imaging. The proposed block-oriented data acquisition system relies on a high-speed DSP processor for fully digital trigger and on-line event processing that surpasses the performance of traditional analog coincidence detection systems. A mixed-signal board has been designed and manufactured. The analog section comprises 12 coaxial inputs (six per head) which are digitized by means of two 8-channel 12-bit 40-MHz ADCs in order to acquire the scintillation pulse, the charge division signals and the depth of interaction within the scintillator. At the digital section, a state-of-the-art FPGA is used as deserializer and also implements the DMA interface to the DSP processor by storing each digitized channel into a fast embedded FIFO memory. The system incorporates a high-speed USB 2.0 interface to the host computer.

  3. Search for Sub-TeV Gamma Rays Coincident with BATSE Gamma Ray Bursts

    CERN Document Server

    Poirier, J; Gress, J; Race, D

    2003-01-01

    Project GRAND is a 100m x 100m air shower array of proportional wire chambers (PWCs). There are 64 stations each with eight 1.29 m^2 PWC planes arranged in four orthogonal pairs placed vertically above one another to geometrically measure the angles of charged secondaries. A steel plate above the bottom pair of PWCs differentiates muons (which pass undeflected through the steel) from non-penetrating particles. FLUKA Monte Carlo studies show that a TeV gamma ray striking the atmosphere at normal incidence produces 0.23 muons which reach ground level where their angles and identities are measured. Thus, paradoxically, secondary muons are used as a signature for gamma ray primaries. The data are examined for possible angular and time coincidences with eight gamma ray bursts (GRBs) detected by BATSE. Seven of the GRBs were selected because of their good acceptance by GRAND and high BATSE Fluence. The eighth GRB was added due to its possible coincident detection by Milagrito. For each of the eight candidate GRBs, ...

  4. Coincidence detection of spatially correlated photon pairs with a monolithic time-resolving detector array

    CERN Document Server

    Unternährer, Manuel; Gasparini, Leonardo; Stoppa, David; Stefanov, André

    2016-01-01

    We demonstrate coincidence measurements of spatially entangled photons by means of a novel type of multi-pixel based detection array. The adopted sensor is a fully digital 8$\\times$16 silicon photomultiplier array allowing not only photon counting but also per-pixel time stamping of the arrived photons with a resolution of 65 ps. Together with a frame rate of 500 kfps, this property exceeds the capabilities of conventional charge-coupled device cameras which have become of growing interest for the detection of transversely correlated photon pairs. The sensor is used to measure a second-order correlation function for various non-collinear configurations of entangled photons generated by spontaneous parametric down-conversion. The experimental results are compared to theory.

  5. Momentum spectrometer for electron-electron coincidence studies on superconductors.

    Science.gov (United States)

    Wallauer, Robert; Voss, Stefan; Foucar, Lutz; Bauer, Tobias; Schneider, Deborah; Titze, Jasmin; Ulrich, Birte; Kreidi, Katharina; Neumann, Nadine; Havermeier, Tilo; Schöffler, Markus; Jahnke, Till; Czasch, Achim; Schmidt, Lothar; Kanigel, Amit; Campuzano, Juan Carlos; Jeschke, Harald; Valenti, Roser; Müller, Andreas; Berner, Götz; Sing, Michael; Claessen, Ralph; Schmidt-Böcking, Horst; Dörner, Reinhard

    2012-10-01

    We present a new experimental setup to study electron-electron coincidences from superconducting surfaces. In our approach, electrons emitted from a surface are projected onto a time- and position-sensitive microchannel plate detector with delayline position readout. Electrons that are emitted within 2 π solid angle with respect to the surface are detected in coincidence. The detector used is a hexagonal delayline detector with enhanced multiple hit capabilities. It is read out with a Flash analog-to-digital converter. The three-dimensional momentum vector is obtained for each electron. The intrinsic dead time of the detector has been greatly reduced by implementing a new algorithm for pulse analysis. The sample holder has been matched to fit the spectrometer while being capable of cooling down the sample to 4.5 K during the measurement and heating it up to 420 K for the cleaning procedure. PMID:23126780

  6. Electron--photon coincidence technique for electron impact on atoms

    International Nuclear Information System (INIS)

    A brief introduction is given to the general theory of the electron photon coincidence technique, and the specific application to 1P and 3P excitations in helium is described. The relation between the complex excitation amplitudes which characterize the collision process and the alignment and orientation of the excited atoms is emphasized. The data from the first electron photon angular correlation measurements are presented. These data yield values for the ratio of differential cross sections for exciting the degenerate sublevels and the relative phase of the corresponding amplitudes, or, equivalently, the alignment and orientation parameters. The results are obtained in dimensionless form and are free from absolute calibration or normalization difficulties. They are compared with various theoretical approximations. The application of the coincidence technique to a measurement of threshold polarization is described and results for 31P excitations are discussed

  7. Data Acquisition System for Electron Energy Loss Coincident Spectrometers

    Institute of Scientific and Technical Information of China (English)

    Zhang Chi; Yu Xiaoqi; Yang Tao

    2005-01-01

    A Data Acquisition System (DAQ) for electron energy loss coincident spectrometers (EELCS) has been developed. The system is composed of a Multiplex Time-Digital Converter (TDC) that measures the flying time of positive and negative ions and a one-dimension positionsensitive detector that records the energy loss of scattering electrons. The experimental data are buffered in a first-in-first-out(FIFO) memory module, then transferred from the FIFO memory to PC by the USB interface. The DAQ system can record the flying time of several ions in one collision, and allows of different data collection modes. The system has been demonstrated at the Electron Energy Loss Coincident Spectrometers at the Laboratory of Atomic and Molecular Physics, USTC. A detail description of the whole system is given and experimental results shown.

  8. Coincidence Doppler Broadening of Positron Annihilation Radiation in Fe

    Science.gov (United States)

    do Nascimento, E.; Vanin, V. R.; Maidana, N. L.; Helene, O.

    2013-06-01

    We measured the Doppler broadening annihilation radiation spectrum in Fe, using 22NaCl as a positron source, and two Ge detectors in coincidence arrangement. The two-dimensional coincidence energy spectrum was fitted using a model function that included positron annihilation with the conduction band and 3d electrons, 3s and 3p electrons, and in-flight positron annihilation. Detectors response functions included backscattering and a combination of Compton and pulse pileup, ballistic deficit and shaping effects. The core electrons annihilation intensity was measured as 16.4(3) %, with almost all the remainder assigned to the less bound electrons. The obtained results are in agreement with published theoretical values.

  9. Simplified slow anti-coincidence circuit for Compton suppression systems

    International Nuclear Information System (INIS)

    Slow coincidence circuits for the anti-coincidence measurements have been considered for use in Compton suppression technique. The simplified version of the slow circuit has been found to be fast enough, satisfactory and allows an easy system setup, particularly with the advantage of the automatic threshold setting of the low-level discrimination. A well-type NaI detector as the main detector surrounded by plastic guard detector has been arranged to investigate the performance of the Compton suppression spectrometer using the simplified slow circuit. The system has been tested to observe the improvement in the energy spectra for medium to high-energy gamma-ray photons from terrestrial and environmental samples

  10. Safeguards Technology Factsheet 3He-free Neutron Coincidence Counter

    International Nuclear Information System (INIS)

    A full scale thermal neutron coincidence counter (High Level Neutron Counter - Boron: HLNB) based on 3He alternative detection technology was designed and built at LANL and field tested at Plutonium Conversion Development Facility (PCDF) of Japan Atomic Energy Agency (JAEA) during FY15. HLNB is based on boron-lined proportional plates that replace the traditional 3He proportional tubes and was designed as a direct alternative to 3He-based High Level Neutron Coincidence Counter (HLNC-II). During the JAEA field trial the HLNB demonstrated comparable performance to HLNC-II, which represents a key development in the area of 3He alternative technologies and provides a complete demonstration of the technology for nuclear safeguards applications including high mass MOX samples.

  11. Simplified slow anti-coincidence circuit for Compton suppression systems.

    Science.gov (United States)

    Al-Azmi, Darwish

    2008-08-01

    Slow coincidence circuits for the anti-coincidence measurements have been considered for use in Compton suppression technique. The simplified version of the slow circuit has been found to be fast enough, satisfactory and allows an easy system setup, particularly with the advantage of the automatic threshold setting of the low-level discrimination. A well-type NaI detector as the main detector surrounded by plastic guard detector has been arranged to investigate the performance of the Compton suppression spectrometer using the simplified slow circuit. The system has been tested to observe the improvement in the energy spectra for medium to high-energy gamma-ray photons from terrestrial and environmental samples. PMID:18222698

  12. High-level neutron coincidence counter (HLNCC): users' manual

    International Nuclear Information System (INIS)

    This manual describes the portable High-Level Neutron Coincidence Counter (HLNCC) developed at the Los Alamos Scientific Laboratory (LASL) for the assay of plutonium, particularly by inspectors of the International Atomic Energy Agency (IAEA). The counter is designed for the measurement of the effective 240Pu mass in plutonium samples which may have a high plutonium content. The following topics are discussed: principle of operation, description of the system, operating procedures, and applications

  13. ECOLOGIC CRISIS AND ECONOMIC CRISIS. IS IT A COINCIDENCE?

    OpenAIRE

    Ştefania-Diana Ioniţă-Burda; Cristian Giuseppe Zaharie; Oana-Elena Mitran-Costache

    2011-01-01

    We constantly speak about the crisis, a phenomenon which characterizes both the individual and the society. The individual is always in a crisis of time,inspiration etc. In turn, society undergoes periods of ecologic, economic, financial,social, political crisis. From among crisis forms, two of them are particularly worth noticing: the ecologic crisis and the economic crisis. Could their coexistence be a mere coincidence or maybe …?

  14. Photon–photon coincidence apparatus with position sensitive detectors

    International Nuclear Information System (INIS)

    An apparatus for the coincident detection of two photons in the visible and VUV spectral range is presented equipped with two position- and time resolving detectors. The equipment enables angular resolution for the detected photons and thus allows an angular correlation between the two detected photons without changing the target cell geometry. Two different configurations of this apparatus are presented and compared in terms of solid angle coverage, imaging properties and suitability for their use in gas phase experiments at synchrotron radiation facilities

  15. Coincidence Detection Using Spiking Neurons with Application to Face Recognition

    OpenAIRE

    Fadhlan Kamaruzaman; Amir Akramin Shafie; Yasir M. Mustafah

    2015-01-01

    We elucidate the practical implementation of Spiking Neural Network (SNN) as local ensembles of classifiers. Synaptic time constant τs is used as learning parameter in representing the variations learned from a set of training data at classifier level. This classifier uses coincidence detection (CD) strategy trained in supervised manner using a novel supervised learning method called τs Prediction which adjusts the precise timing of output spikes towards the desired spike timing through itera...

  16. Non-minimal quintessence: Dynamics and coincidence problem

    Indian Academy of Sciences (India)

    Fatimah Shojai; Ali Shojai

    2011-12-01

    Brans–Dicke scalar–tensor theory provides a conformal coupling of the scalar field with gravity in Einstein’s frame. This model is equivalent to an interacting quintessence in which dark matter is coupled to dark energy. This provides a natural mechanism to alleviate the coincidence problem. We investigate the dynamics of this model and show that it leads to comparable dark energy and dark matter densities today.

  17. Non-minimal Quintessence: Dynamics and coincidence problem

    OpenAIRE

    Shojai, Fatimah; Shojai, Ali

    2011-01-01

    Brans--Dicke scalar--tensor theory provides a conformally coupling of the scalar field with gravity in Einstein's frame. This model is equivalent to an interacting quintessence in which dark matter is coupled to dark energy. This provides a natural mechanism to alleviate the coincidence problem. We investigate the dynamics of this model and show that it leads to comparable dark energy and dark matter densities today.

  18. Detector system for the study of low energy heavy ion reactions using kinematic coincidence technique

    Energy Technology Data Exchange (ETDEWEB)

    Jhingan, Akhil, E-mail: akhil@iuac.res.in [Inter University Accelerator Centre, P. O. Box 10502, New Delhi 110067 (India); Kalkal, S. [Deptartment of Physics and Astrophysics, Delhi University, Delhi 110007 (India); Sugathan, P.; Golda, K.S.; Ahuja, R.; Gehlot, J.; Madhavan, N. [Inter University Accelerator Centre, P. O. Box 10502, New Delhi 110067 (India); Behera, B.R. [Deptartment of Physics, Panjab University, Chandigarh 160014 (India); Mandal, S.K. [Deptartment of Physics and Astrophysics, Delhi University, Delhi 110007 (India)

    2014-05-01

    The characteristics and performance of a new detector system developed for the study of low energy heavy ion binary reactions using the kinematic coincidence technique are presented. The detector system has been developed to carry out experiments such as multi-nucleon transfer reactions using the General Purpose Scattering Chamber (GPSC) facility at IUAC [1,2]. The detector system consists of a pair of two-dimensional position sensitive multi wire proportional counter (MWPC) and a ΔE−E gas ionization chamber. Both MWPC have an active area of 5×5 cm{sup 2}, and provide position signals in horizontal (X) and vertical (Y) plane, and timing signal for time of flight measurements. The main design feature of MWPC is the reduced wire pitch of 0.025 in. (0.635 mm) in all electrodes, giving uniform field and faster charge collection, and usage of 10μm diameter in anode frame which gives higher gains. The position resolution of the detectors was determined to be 0.45 mm FWHM and time resolution was estimated to be 400 ps FWHM. The detector could handle heavy ion count rates exceeding 100 kHz without any break down. The timing and position signals of the detectors are used for kinematic coincidence measurements and subsequent extraction of their mass and angular distributions. The ionization chamber has a conventional transverse field geometry with segmented anode providing multiple ΔE signals for nuclear charge (Z) identification. This article describes systematic study of these detectors in terms of efficiency, count rate handling capability, time, position and energy resolution.

  19. Glyphosate applications on arable fields considerably coincide with migrating amphibians.

    Science.gov (United States)

    Berger, Gert; Graef, Frieder; Pfeffer, Holger

    2013-01-01

    Glyphosate usage is increasing worldwide and the application schemes of this herbicide are currently changing. Amphibians migrating through arable fields may be harmed by Glyphosate applied to field crops. We investigated the population-based temporal coincidence of four amphibian species with Glyphosate from 2006 to 2008. Depending on a) age- and species-specific main migration periods, b) crop species, c) Glyphosate application mode for crops, and d) the presumed DT50 value (12 days or 47 days) of Glyphosate, we calculated up to 100% coincidence with Glyphosate. The amphibians regularly co-occur with pre-sowing/pre-emerging Glyphosate applications to maize in spring and with stubble management prior to crop sowing in late summer and autumn. Siccation treatment in summer coincides only with early pond-leaving juveniles. We suggest in-depth investigations of both acute and long-term effects of Glyphosate applications on amphibian populations not only focussed on exposure during aquatic periods but also terrestrial life stages.

  20. Charge independence and charge symmetry

    CERN Document Server

    Miller, G A; Miller, Gerald A; van Oers, Willem T H

    1994-01-01

    Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry breaking effects in nuclear and particle physics and the implications of those effects are reviewed.

  1. Charged Leptons

    CERN Document Server

    Albrecht, J; Babu, K; Bernstein, R H; Blum, T; Brown, D N; Casey, B C K; Cheng, C -h; Cirigliano, V; Cohen, A; Deshpande, A; Dukes, E C; Echenard, B; Gaponenko, A; Glenzinski, D; Gonzalez-Alonso, M; Grancagnolo, F; Grossman, Y; Harnik, R; Hitlin, D G; Kiburg, B; Knoepfe, K; Kumar, K; Lim, G; Lu, Z -T; McKeen, D; Miller, J P; Ramsey-Musolf, M; Ray, R; Roberts, B L; Rominsky, M; Semertzidis, Y; Stoeckinger, D; Talman, R; Van De Water, R; Winter, P

    2013-01-01

    This is the report of the Intensity Frontier Charged Lepton Working Group of the 2013 Community Summer Study "Snowmass on the Mississippi", summarizing the current status and future experimental opportunities in muon and tau lepton studies and their sensitivity to new physics. These include searches for charged lepton flavor violation, measurements of magnetic and electric dipole moments, and precision measurements of the decay spectrum and parity-violating asymmetries.

  2. Electron coincidence spectroscopy - an introduction to momentum space chemistry

    International Nuclear Information System (INIS)

    The application of electron coincidence spectroscopy or (e,2e) to obtaining detailed information on the dynamic structure of atoms and molecules is discussed. The technique obtains separation energy spectra and spherically averaged electron momentum distributions for each molecular orbital in the valence region. A brief discussion of molecular orbital density functions in momentum space is given. The results using Hartree-Fock wave functions for atomic orbitals and LCAO-MO-SCF wave functions for molecular orbitals are compared with (e,2e) data. The sensitivity of the data to electron correlations in either the initial or final ion many body states is discussed and examples given

  3. Coincidence corrected efficiency calibration of Compton-suppressed HPGe detectors

    Energy Technology Data Exchange (ETDEWEB)

    Aucott, T.

    2015-04-20

    The authors present a reliable method to calibrate the full-energy efficiency and the coincidence correction factors using a commonly-available mixed source gamma standard. This is accomplished by measuring the peak areas from both summing and non-summing decay schemes and simultaneously fitting both the full-energy efficiency, as well as the total efficiency, as functions of energy. By using known decay schemes, these functions can then be used to provide correction factors for other nuclides not included in the calibration standard.

  4. Ulcerative colitis six years after colon cancer: only a coincidence?

    Science.gov (United States)

    Sakellakis, Minas; Makatsoris, Thomas; Gkermpesi, Maria; Peroukidis, Stavros; Kalofonos, Haralabos

    2014-01-01

    The association between inflammatory bowel disease and colorectal cancer is well known. Ulcerative colitis is a risk factor for the development of colorectal cancer, and this risk increases with the activity and duration of bowel inflammation. Here we describe the case of a 52-year-old man who developed ulcerative colitis 6 years after the diagnosis and treatment of colon cancer. Although this could be a coincidence, there could be additional possibilities, like pre-existence of quiescent colitis, late effect of therapy, or maybe the existence of common pathogenetic factors contributing to the development of ulcerative colitis and colorectal cancer. PMID:24855393

  5. Enhanced PET resolution by combining pinhole collimation and coincidence detection.

    Science.gov (United States)

    DiFilippo, Frank P

    2015-10-21

    Spatial resolution of clinical PET scanners is limited by detector design and photon non-colinearity. Although dedicated small animal PET scanners using specialized high-resolution detectors have been developed, enhancing the spatial resolution of clinical PET scanners is of interest as a more available alternative. Multi-pinhole 511 keV SPECT is capable of high spatial resolution but requires heavily shielded collimators to avoid significant background counts. A practical approach with clinical PET detectors is to combine multi-pinhole collimation with coincidence detection. In this new hybrid modality, there are three locations associated with each event, namely those of the two detected photons and the pinhole aperture. These three locations over-determine the line of response and provide redundant information that is superior to coincidence detection or pinhole collimation alone. Multi-pinhole collimation provides high resolution and avoids non-colinearity error but is subject to collimator penetration and artifacts from overlapping projections. However the coincidence information, though at lower resolution, is valuable for determining whether the photon passed near a pinhole within the cone acceptance angle and for identifying through which pinhole the photon passed. This information allows most photons penetrating through the collimator to be rejected and avoids overlapping projections. With much improved event rejection, a collimator with minimal shielding may be used, and a lightweight add-on collimator for high resolution imaging is feasible for use with a clinical PET scanner. Monte Carlo simulations were performed of a (18)F hot rods phantom and a 54-pinhole unfocused whole-body mouse collimator with a clinical PET scanner. Based on coincidence information and pinhole geometry, events were accepted or rejected, and pinhole-specific crystal-map projections were generated. Tomographic images then were reconstructed using a conventional pinhole SPECT

  6. Spectroscopy of fission fragments using prompt-delayed coincidence technique

    Indian Academy of Sciences (India)

    R Palit; S Biswas

    2015-09-01

    The time-stamp structure of the digital data acquisition system of the Indian National Gamma Array (INGA) has been utilized to carry out prompt-delayed coincidence technique for the spectroscopic study of fission fragments. This technique was found to be useful to determine the states above the long-lived isomer (with half-life up to ∼5 s), present in the fission fragments. The angular correlation of -rays, emitted by the fission fragments, has also been used in the present INGA geometry to determine the spins of the de-exciting states.

  7. Violation of Bell inequalities through the coincidence-time loophole

    OpenAIRE

    Morgan, Peter

    2008-01-01

    The coincidence-time loophole was identified by Larsson & Gill (Europhys. Lett. 67, 707 (2004)); a concrete model that exploits this loophole has recently been described by De Raedt et al. (Found. Phys., to appear). It is emphasized here that De Raedt et al.'s model is experimentally testable. De Raedt et al.'s model also introduces contextuality in a novel and classically more natural way than the use of contextual particle properties, by introducing a probabilistic model of a limited set of...

  8. High-level neutron coincidence counter maintenance manual

    International Nuclear Information System (INIS)

    High-level neutron coincidence counter operational (field) calibration and usage is well known. This manual makes explicit basic (shop) check-out, calibration, and testing of new units and is a guide for repair of failed in-service units. Operational criteria for the major electronic functions are detailed, as are adjustments and calibration procedures, and recurrent mechanical/electromechanical problems are addressed. Some system tests are included for quality assurance. Data on nonstandard large-scale integrated (circuit) components and a schematic set are also included

  9. Coincidence of Vietoris and Wijsman Topologies: A New Proof

    OpenAIRE

    Holá, L’.

    1997-01-01

    Let (X, d) be a metric space and CL(X) the family of all nonempty closed subsets of X. We provide a new proof of the fact that the coincidence of the Vietoris and Wijsman topologies induced by the metric d forces X to be a compact space. In the literature only a more involved and indirect proof using the proximal topology is known. Here we do not need this intermediate step. Moreover we prove that (X, d) is boundedly compact if and only if the bounded Vietoris and Wijsman to...

  10. Coincident systemic lupus erythematosus and psoriasis vulgaris: a case report.

    Science.gov (United States)

    Wang, Y; Da, G; Yu, Y; Han, J; Li, H

    2015-12-01

    Psoriasis vulgaris is an autoimmune chronic inflammatory skin disease, but its association with other typical autoimmune disease such as systemic lupus erythematosus has only occasionally been reported. We presented a 25-year-old female who developed systemic lupus erythematosus associated with psoriasis vulgaris. Her conditions were in good control after she got administration of prednisolone (5 mg/day) and Tripterygium Wilfordii Hook (20 mg/day). It is necessary to integrate past history and physical examination to diagnose coincident SLE and psoriasis, and combined treatment with prednisolone and Tripterygium Wilfordii Hook proves effective.

  11. Photoelectron-Auger electron coincidence study for condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    Stefani, G. [Department of Physics and Unita' INFM, University Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy)]. E-mail: stefani@fis.uniroma3.it; Gotter, R. [National Laboratory TASC-INFM, Area Science Park, SS 14 Km 163.5, Basovizza, I-34012 Trieste (Italy); Ruocco, A. [Department of Physics and Unita INFM, University Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy); Offi, F. [Department of Physics and Unita INFM, University Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy); Pieve, F. Da [Department of Physics and Unita INFM, University Roma Tre, Via della Vasca Navale 84, I-00146 Rome (Italy); Iacobucci, S. [IMIP-CNR Area della Ricerca di Roma, via Salaria Km 29, 3 Montelibretti (Italy); Morgante, A. [National Laboratory TASC-INFM, Area Science Park, SS 14 Km 163.5, Basovizza, I-34012 Trieste (Italy); Verdini, A. [National Laboratory TASC-INFM, Area Science Park, SS 14 Km 163.5, Basovizza, I-34012 Trieste (Italy); Liscio, A. [IMIP-CNR Area della Ricerca di Roma, via Salaria Km 29, 3 Montelibretti (Italy); Yao, H. [Department of Physics and Astronomy and Laboratory of Surface Modification, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08855 (United States); Bartynski, R.A. [Department of Physics and Astronomy and Laboratory of Surface Modification, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08855 (United States)

    2004-12-01

    Advances in materials science have produced a wide array of new solid-state systems with tunable properties and previously unattainable combinations of phenomena that hold the promise of entirely new approaches to technological applications. Invariably, these new materials are increasingly complex and include a large number of constituents in a variety of chemical states. Entirely new theoretical and experimental approaches are needed to gain the insights necessary for intelligent engineering of these materials. In the past 20 years, a steadily increasing number of electron-electron coincidence experiments on atoms and molecules have demonstrated the capability of investigating complicated systems with sensitivity and specificity well beyond the limits imposed by conventional electron spectroscopies. Over the past decade or so, Auger-photoelectron coincidence spectroscopy (APECS) has emerged as a powerful technique for obtaining detailed information about complex materials systems. Moreover, the recent advent of angle-resolved (AR)-APECS has introduced a new level of discrimination in studying the distribution of electrons photoemitted from complex systems. In this review, we describe the basic ideas behind APECS and discuss a study of the SiO{sub 2} system as an example of the unique information this technique can provide. We then introduce the concept of AR-APECS, explain its novel state and angular momentum selectivity that can be used to disentangle information about complex systems that is hidden to conventional spectroscopies. Examples of AR-APECS measurements from Cu, Ge, and graphite that exemplify the capabilities of this technique are presented.

  12. Radio transient following FRB 150418: afterglow or coincident AGN flare?

    CERN Document Server

    Li, Ye

    2016-01-01

    Recently, Keane et al. reported the discovery of a fading radio transient following FRB 150418, and interpreted it as the afterglow of the FRB. Williams \\& Berger, on the other hand, suggested that the radio transient is analogous to a group of variable radio sources, so that it could be a coincident AGN flare in the observational beam of the FRB. A new observation with VLA showed a re-brightening, which is consistent with the AGN picture. Here, using the radio survey data of Ofek et al., we statistically examine the chance coincidence probability to produce an event like the FRB 150418 transient. We find that the probabilities to produce a variable radio transient with at least the same variability amplitude and signal-to-noise ratio as the FRB 150415 transient, without and with the VLA point, are $P_1 \\sim 6 \\times 10^{-4}$ and $P_1 \\sim 2 \\times 10^{-3}$, respectively. In addition, the chance probability to have a fading transient detected following a random time (FRB time) is less than $P_2 \\sim 10^{-...

  13. Coincidence-anticipation timing requirements are different in racket sports.

    Science.gov (United States)

    Akpinar, Selçuk; Devrilmez, Erhan; Kirazci, Sadettin

    2012-10-01

    The aim of this study was to compare the coincidence-anticipation timing accuracy of athletes of different racket sports with various stimulus velocity requirements. Ninety players (15 girls, 15 boys for each sport) from tennis (M age = 12.4 yr., SD = 1.4), badminton (M age = 12.5 yr., SD = 1.4), and table tennis (M age = 12.4 yr., SD = 1.2) participated in this study. Three different stimulus velocities, low, moderate, and high, were used to simulate the velocity requirements of these racket sports. Tennis players had higher accuracy when they performed under the low stimulus velocity compared to badminton and table tennis players. Badminton players performed better under the moderate speed comparing to tennis and table tennis players. Table tennis players had better performance than tennis and badminton players under the high stimulus velocity. Therefore, visual and motor systems of players from different racket sports may adapt to a stimulus velocity in coincidence-anticipation timing, which is specific to each type of racket sports.

  14. Coincidence of lung cancer and silicosis in Czechoslovak uranium miners

    International Nuclear Information System (INIS)

    27 patients with established coincidence of lung cancer and silicosis from a group of 1607 cases of lung cancer from radioactive compounds, and 166 cases of pneumoconiosis were reported by the Occupational Diseases Ward of the works Institute of National Health in Uranium Industry in the 1962 to 1986 years. Lung cancer was found in 16% of reported silicosis patients, in 81% it was simple silicosis, in 50% of cases in was an epidermoid type of cancer. In two cases the malignant process originated in the silicotic node, in one case from a tuberculoma. Lung cancer occurred most frequently in the right lower lung region. The mean age of the silicosis group was 48.6 years and 56.0 years for the lung cancer group. No difference was thus seen from the mean age of patients with lung cancer from radioactive compounds diagnosed in the years 1976 to 1980 but it was significantly lower that the reported average age of patients with coincidence of lung cancer and pneumoconiosis in the population not exposed to ionizing radiation. (author). 2 figs., 1 tab., 18 refs

  15. CSF biomarkers cutoffs: the importance of coincident neuropathological diseases.

    Science.gov (United States)

    Toledo, Jon B; Brettschneider, Johannes; Grossman, Murray; Arnold, Steven E; Hu, William T; Xie, Sharon X; Lee, Virginia M-Y; Shaw, Leslie M; Trojanowski, John Q

    2012-07-01

    The effects of applying clinical versus neuropathological diagnosis and the inclusion of cases with coincident neuropathological diagnoses have not been assessed specifically when studying cerebrospinal fluid (CSF) biomarker classification cutoffs for patients with neurodegenerative diseases that cause dementia. Thus, 142 neuropathologically diagnosed neurodegenerative dementia patients [71 Alzheimer's disease (AD), 29 frontotemporal lobar degeneration (FTLD), 3 amyotrophic lateral sclerosis, 7 dementia with Lewy bodies, 32 of which cases also had coincident diagnoses] were studied. 96 % had enzyme-linked immunosorbant assay (ELISA) CSF data and 77 % had Luminex CSF data, with 43 and 46 controls for comparison, respectively. Aβ(42), total, and phosphorylated tau(181) were measured. Clinical and neuropathological diagnoses showed an 81.4 % overall agreement. Both assays showed high sensitivity and specificity to classify AD subjects against FTLD subjects and controls, and moderate sensitivity and specificity for classifying FTLD subjects against controls. However, among the cases with neuropathological diagnoses of AD plus another pathology (26.8 % of the sample), 69.4 % (ELISA) and 96.4 % (Luminex) were classified as AD according to their biomarker profiles. Use of clinical diagnosis instead of neuropathological diagnosis led to a 14-17 % underestimation of the biomarker accuracy. These results show that while CSF Aβ and tau assays are useful for diagnosis of AD and neurodegenerative diseases even at MCI stages, CSF diagnostic analyte panels that establish a positive diagnosis of Lewy body disease and FTLD are also needed, and must be established based on neuropathological rather than clinical diagnoses.

  16. Coincidence Detection Using Spiking Neurons with Application to Face Recognition

    Directory of Open Access Journals (Sweden)

    Fadhlan Kamaruzaman

    2015-01-01

    Full Text Available We elucidate the practical implementation of Spiking Neural Network (SNN as local ensembles of classifiers. Synaptic time constant τs is used as learning parameter in representing the variations learned from a set of training data at classifier level. This classifier uses coincidence detection (CD strategy trained in supervised manner using a novel supervised learning method called τs Prediction which adjusts the precise timing of output spikes towards the desired spike timing through iterative adaptation of τs. This paper also discusses the approximation of spike timing in Spike Response Model (SRM for the purpose of coincidence detection. This process significantly speeds up the whole process of learning and classification. Performance evaluations with face datasets such as AR, FERET, JAFFE, and CK+ datasets show that the proposed method delivers better face classification performance than the network trained with Supervised Synaptic-Time Dependent Plasticity (STDP. We also found that the proposed method delivers better classification accuracy than k nearest neighbor, ensembles of kNN, and Support Vector Machines. Evaluation on several types of spike codings also reveals that latency coding delivers the best result for face classification as well as for classification of other multivariate datasets.

  17. First principle active neutron coincidence counting measurements of uranium oxide

    Science.gov (United States)

    Goddard, Braden; Charlton, William; Peerani, Paolo

    2014-03-01

    Uranium is present in most nuclear fuel cycle facilities ranging from uranium mines, enrichment plants, fuel fabrication facilities, nuclear reactors, and reprocessing plants. The isotopic, chemical, and geometric composition of uranium can vary significantly between these facilities, depending on the application and type of facility. Examples of this variation are: enrichments varying from depleted (~0.2 wt% 235U) to high enriched (>20 wt% 235U); compositions consisting of U3O8, UO2, UF6, metallic, and ceramic forms; geometries ranging from plates, cans, and rods; and masses which can range from a 500 kg fuel assembly down to a few grams fuel pellet. Since 235U is a fissile material, it is routinely safeguarded in these facilities. Current techniques for quantifying the 235U mass in a sample include neutron coincidence counting. One of the main disadvantages of this technique is that it requires a known standard of representative geometry and composition for calibration, which opens up a pathway for potential erroneous declarations by the State and reduces the effectiveness of safeguards. In order to address this weakness, the authors have developed a neutron coincidence counting technique which uses the first principle point-model developed by Boehnel instead of the "known standard" method. This technique was primarily tested through simulations of 1000 g U3O8 samples using the Monte Carlo N-Particle eXtended (MCNPX) code. The results of these simulations showed good agreement between the simulated and exact 235U sample masses.

  18. Performance of a coincidence based blood activity monitor

    International Nuclear Information System (INIS)

    A new device has been constructed that measures the positron emitting radio-tracer concentration in arterial blood by extracting blood with a peristaltic pump, then measuring the activity concentration by detecting coincident pairs of 511 keV photons with a pair of heavy inorganic scintillators attached to photomultiplier tubes. The sensitivity of this device is experimentally determined to be 610 counts/second per μCi/ml, and has a paralyzing dead time of 1.2 μs, so is capable of measuring blood activity concentration as high as 1 mCi/ml. Its performance is compared to two other blood monitoring methods: discrete blood samples counted with a well counter and device that uses a plastic scintillator to directly detect positrons. The positron detection efficiency of this device for 18F is greater than the plastic scintillation counter, and also eliminates the radioisotope dependent correction factors necessary to convert count rate to absolute concentration. Coincident photon detection also has the potential of reducing the background compared to direct positron detection, thereby increasing the minimum detectable isotope concentration. 10 refs., 6 figs

  19. VUV state-selected photoionization of thermally-desorbed biomolecules by coupling an aerosol source to an imaging photoelectron/photoion coincidence spectrometer: case of the amino acids tryptophan and phenylalanine.

    Science.gov (United States)

    Gaie-Levrel, François; Garcia, Gustavo A; Schwell, Martin; Nahon, Laurent

    2011-04-21

    Gas phase studies of biological molecules provide structural and dynamical information on isolated systems. The lack of inter- or intra-molecular interactions facilitates the interpretation of the experimental results through theoretical calculations, and constitutes an informative complement to the condensed phase. However advances in the field are partially hindered by the difficulty of vaporising these systems, most of which are thermally unstable. In this work we present a newly developed aerosol mass thermodesorption setup, which has been coupled to a Velocity Map Imaging (VMI) analyzer operated in coincidence with a Wiley-McLaren Time of Flight spectrometer, using synchrotron radiation as a single photon ionization source. Although it has been previously demonstrated that thermolabile molecules such as amino acids can be produced intact by the aerosol vaporisation technique, we show how its non-trivial coupling to a VMI analyzer plus the use of electron/ion coincidences greatly improves the concept in terms of the amount of spectroscopic and dynamic information that can be extracted. In this manner, we report on the valence shell ionization of two amino acids, tryptophan and phenylalanine, for which threshold photoelectron spectra have been recorded within the first 3 eV above the first ionization energy using synchrotron radiation emitted from the DESIRS beamline located at SOLEIL in France. Their adiabatic ionization energies (IEs) have been measured at 7.40 ± 0.05 and 8.65 ± 0.02 eV, respectively, and their spectra analyzed using existing theoretical data from the literature. The IE values agree well with previously published ones, but are given here with a considerably reduced uncertainty by up to a factor of 5. The photostability of both amino acids is also described in detail, through the measurement of the state-selected fragmentation pathways via the use of threshold electron/ion coincidences (TPEPICO), with appearance energies for the different

  20. IXO-XMS LVSID Anti-Coincidence Detector

    Science.gov (United States)

    Porter, Scott F.; Kilbourne, Caroline

    2010-01-01

    This document describes a high-TRL backup implementation of the anti-coincidence detector for the IXO/XMS instrument. The backup detector, hereafter referred to as the low-voltage silicon ionization detector (LVSID), has been successfully flown on Astro-E2 (Suzaku)/XRS and is currently being implemented, without significant changes, on the Astro-H/SXS instrument. The LVSID anti-coincidence detector on Astro-E2/XRS operated successfully for almost 2 years, and was not affected by the loss of liquid helium in that instrument. The LVSID continues to operate after almost 5 years on-orbit (LEO, 550 km) but with slightly increased noise following the expected depletion of solid Neon after 22 months. The noise of the device is increased after the loss of sNe due to thermally induced bias and readout noise. No radiation damage, or off-nominal affects have been observed with the LVSID on-orbit during the Astro-E2/XRS program. A detector die from the same fabrication run will be used on the Astro-H/SXS mission. The LVSID technology and cryogenic JFET readout system is thus TRL 9. The technology is described in detail in section 2. The IXO/XMS "backup-up" anti-coincidence detector is a small array of LVSID detectors that are almost identical to those employed for Astro -E2/XRS as described in this document. The readout system is identical and, infact would use the same design as the Astro -E2/XRS JFET amplifier module (19 channels) essentially without changes except for its mechanical mount. The changes required for the IXO/XMS LVSID array are limited to the mounting of the LVSID detectors, and the mechanical mounting of the JFET amplifier sub-assembly. There is no technical development needed for the IXO/XMS implementation and the technology is ready for detailed design-work leading to PDR. The TRL level is thus at least 6, and possibly higher. Characteristics of an IXO/XMS LVSID anti-co detector are given in Table 1 and described in detail in section 3.

  1. Sub-wavelength bubble in photon coincidence detection

    CERN Document Server

    Liu, Ruifeng; Zhou, Yu; Gao, Hong; Li, Fuli

    2013-01-01

    Sub-wavelength interference has a potential application in lithography to beat the classical Rayleigh limit of resolution. We carefully study the second-order correlation theory and find there is a bubble of sub-wavelength interference in photon coincidence detection. A Young's double-slit experiment with thermal light is carried out to test the second-order correlation pattern. The result shows that when different scanning ways of two point detectors are chosen, we can get arbitrary-wavelength interference patterns. We then give a theoretical explanation to this surprising result, and find this explanation is also suitable for the result by using entangled light. Furthermore, the question of whether this kind of arbitrary-wavelength interference patterns can be used in quantum lithography is also analyzed.

  2. Ulcerative colitis six years after colon cancer: only a coincidence?

    Directory of Open Access Journals (Sweden)

    Sakellakis M

    2014-04-01

    Full Text Available Minas Sakellakis,1 Thomas Makatsoris,1 Maria Gkermpesi,2 Stavros Peroukidis,1 Haralabos Kalofonos11Division of Oncology, Department of Medicine, 2Department of Pathology, University, Hospital of Patras, Patras, GreeceAbstract: The association between inflammatory bowel disease and colorectal cancer is well known. Ulcerative colitis is a risk factor for the development of colorectal cancer, and this risk increases with the activity and duration of bowel inflammation. Here we describe the case of a 52-year-old man who developed ulcerative colitis 6 years after the diagnosis and treatment of colon cancer. Although this could be a coincidence, there could be additional possibilities, like pre-existence of quiescent colitis, late effect of therapy, or maybe the existence of common pathogenetic factors contributing to the development of ulcerative colitis and colorectal cancer.Keywords: ulcerative, colitis, colorectal, cancer, inflammation

  3. The spallation in reverse kinematics: what for a coincidence measurement?

    International Nuclear Information System (INIS)

    The Spaladin installation has been designed to study spallation reactions in reverse kinematics. Furthermore, the heavy and light fragments are detected by coincidence which allows us to get an instantaneous picture of the reaction at a level of accuracy better than that obtained through inclusive measurement. The first part is dedicated to the theoretical description of the different mechanisms involved in the spallation reactions. In the second part we describe the Spaladin installation and report some results on the reaction: Fe56 + p at an energy of 1 GeV/nucleon. In the third part we expose the performance of the installation through its simulation with the Geant-IV model. We present a study about the sensitivity of the Spaladin installation to theoretical predictions. The fourth part is dedicated to the future experiments that will be performed with the Spaladin installation. (A.C.)

  4. Commentary on Bayesian coincidence assessment (cross-matching)

    CERN Document Server

    Loredo, Thomas J

    2012-01-01

    This paper is an invited commentary on Tamas Budavari's presentation, "On statistical cross-identification in astronomy," for the Statistical Challenges in Modern Astronomy V conference held at Pennsylvania State University in June 2011. I begin with a brief review of previous work on probabilistic (Bayesian) assessment of directional and spatio-temporal coincidences in astronomy (e.g., cross-matching or cross-identification of objects across multiple catalogs). Then I discuss an open issue in the recent innovative work of Budavari and his colleagues on large-scale probabilistic cross-identification: how to assign prior probabilities that play an important role in the analysis. With a simple toy problem, I show how Bayesian multilevel modeling (hierarchical Bayes) provides a principled framework that justifies and generalizes pragmatic rules of thumb that have been successfully used by Budavari's team to assign priors.

  5. First principle active neutron coincidence counting measurements of uranium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, Braden, E-mail: goddard.braden@gmail.com [Nuclear Security Science and Policy Institute, Texas A and M University, College Station, Texas 77843 (United States); Charlton, William [Nuclear Security Science and Policy Institute, Texas A and M University, College Station, Texas 77843 (United States); Peerani, Paolo [European Commission, EC-JRC-ITU, Ispra (Italy)

    2014-03-01

    Uranium is present in most nuclear fuel cycle facilities ranging from uranium mines, enrichment plants, fuel fabrication facilities, nuclear reactors, and reprocessing plants. The isotopic, chemical, and geometric composition of uranium can vary significantly between these facilities, depending on the application and type of facility. Examples of this variation are: enrichments varying from depleted (∼0.2 wt% {sup 235}U) to high enriched (>20 wt% {sup 235}U); compositions consisting of U{sub 3}O{sub 8}, UO{sub 2}, UF{sub 6}, metallic, and ceramic forms; geometries ranging from plates, cans, and rods; and masses which can range from a 500 kg fuel assembly down to a few grams fuel pellet. Since {sup 235}U is a fissile material, it is routinely safeguarded in these facilities. Current techniques for quantifying the {sup 235}U mass in a sample include neutron coincidence counting. One of the main disadvantages of this technique is that it requires a known standard of representative geometry and composition for calibration, which opens up a pathway for potential erroneous declarations by the State and reduces the effectiveness of safeguards. In order to address this weakness, the authors have developed a neutron coincidence counting technique which uses the first principle point-model developed by Boehnel instead of the “known standard” method. This technique was primarily tested through simulations of 1000 g U{sub 3}O{sub 8} samples using the Monte Carlo N-Particle eXtended (MCNPX) code. The results of these simulations showed good agreement between the simulated and exact {sup 235}U sample masses.

  6. Coincident photoelectron spectroscopy on superconductors; Koinzidente Photoelektronenspektroskopie an Supraleitern

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Stefan

    2011-07-01

    Aim of the performed experiments of this thesis was to attempt to detect Cooper pairs as carriers of the superconducting current directly by means of the photoelectric effect. The method of the coincident photoelectron spectroscopy aims thereby at the detection of two coherently emitted electrons by the interaction with a photon. Because electrostatic analyzers typically cover only a very small spatial angle, which goes along with very low coincidence rates, in connection with this thesis a time-of-flight projection system has been developed, which maps nearly the whole spatial angle on a position-resolving detector. The pulsed light source in form of special synchrotron radiation necessary for the measurement has been adjusted so weak, that only single photons could arrive at the sample. Spectroscoped were beside test measurements on silver layers both a lead monocrystal as representative of the classical BCS superconductors and monocrystalline Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} from the family of the high-temperature superconductors. With excitation energies up to 40 eV could be shown that sufficiently smooth and clean surfaces in the superconducting phase exhibit within the resolving power of about 0.5 eV no recognizable differences in comparison to the normally conducting phase. Beside these studies furthermore the simple photoemission at the different samples and especially in the case of the lead crystal is treated, because here no comparable results are known. Thereby the whole momentum space is discussed and the Fermi surface established as three-dimensional model, by means of which the measurement results are discussed. in the theoretical descriptions different models for the Cooper-pair production are presented, whereby to the momentum exchange with the crystal a special role is attributed, because this can only occur in direct excitations via discrete lattice vectors.

  7. Theoretical Bounds and Practical Constructions for Families of One—Coincidence Sequences in FHMA

    Institute of Scientific and Technical Information of China (English)

    MeiWenhua; YangYixian

    1995-01-01

    Theoretical bounds are given for the number of one-coincidence sequences in syn-chronous FHMA systems,and for the number and period of one-coincidence sequences in asyn-chronous FHMA systems.Several practical constructions for families of one-coincidencesequences are surveyed,and a new model for families of one-coincidence sequences is presented.

  8. Charge transport by holographic Fermi surfaces

    CERN Document Server

    Faulkner, Thomas; Liu, Hong; McGreevy, John; Vegh, David

    2013-01-01

    We compute the contribution to the conductivity from holographic Fermi surfaces obtained from probe fermions in an AdS charged black hole. This requires calculating a certain part of the one-loop correction to a vector propagator on the charged black hole geometry. We find that the current dissipation is as efficient as possible and the transport lifetime coincides with the single-particle lifetime. In particular, in the case where the spectral density is that of a marginal Fermi liquid, the resistivity is linear in temperature.

  9. Black diholes with unbalanced magnetic charges

    CERN Document Server

    Liang, Y C; Teo, Edward

    2001-01-01

    We present a technique that can be used to generate a static, axisymmetric solution of the Einstein-Maxwell-Dilaton equations from a stationary, axisymmetric solution of the vacuum Einstein equations. Starting from the Kerr solution, Davidson and Gedalin have previously made use of this technique to obtain a pair of oppositely charged, extremal dilatonic black holes, known as a black dihole. In this paper, we shall instead start from the Kerr-NUT solution. It will be shown that the new solution can also be interpreted as a dihole, but with the black holes carrying unbalanced magnetic charges. The effect of the NUT-parameter is to introduce a net magnetic charge into the system. Finally, we uplift our solution to ten dimensions to describe a system consisting of D6 and anti-D6-branes with unbalanced charges. The limit in which they coincide agrees with a solution recently derived by Brax et al..

  10. Sustaining IAEA Neutron Coincidence Counting: Past, Present and Future

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory's IAEA Neutron Coincidence Counting (INCC) code is the standard tool for neutron coincidence counting measurements. INCC software and its' predecessors were originally implemented in the 1970s. The measurement and analysis techniques perfected in the code arise from many years of laboratory and field experience by nuclear engineers and physicists. Covering the full arc of INCC's lifecycle, we discuss the engineering approaches used for conception, original development, worldwide deployment of the stand-alone Windows application, more than a decade of sustained maintenance support, and our recent work to carry INCC successfully into future applications. We delve into the recent re-architecture of the INCC code base, an effort to create a maintainable and extensible architecture designed to preserve the existing INCC code base while adding support for new analyzes and instruments (e.g., List Mode PTR-32 and the List Mode Multiplicity Module). INCC now consists of separate modules implementing attended instrumentation control, data file processing, statistical and Pu mass calculation and analyzes, list mode counting and analyzes, reporting functions, and a database support library. Separating functional capabilities in this architecture enables better testing, isolates development risk and enables the use of INCC features in other software systems. We discuss our approach to handling divergent data and protocol support as a result of this re-architecture. INCC has complex testing requirements; we show how the testing effort was reduced by breaking the software into separate modules. This new architecture enables integration of INCC analysis into the IAEA's new Integrated Review and Analysis Programme (iRAP) data review system. iRAP is based on the respected Euratom Comprehensive Review Inspector Software Package (CRISP) software framework, and is expected to be the future data review system for IAEA and Euratom

  11. Super sub-wavelength patterns in photon coincidence detection

    Science.gov (United States)

    Liu, Ruifeng; Zhang, Pei; Zhou, Yu; Gao, Hong; Li, Fuli

    2014-02-01

    High-precision measurements implemented with light are desired in all fields of science. However, light acts as a wave, and the Rayleigh criterion in classical optics yields a diffraction limit that prevents obtaining a resolution smaller than the wavelength. Sub-wavelength interference has potential application in lithography because it beats the classical Rayleigh resolution limit. Here, we carefully study second-order correlation theory to establish the physics behind sub-wavelength interference in photon coincidence detection. A Young's double slit experiment with pseudo-thermal light is performed to test the second-order correlation pattern. The results show that when two point detectors are scanned in different ways, super sub-wavelength interference patterns can be obtained. We then provide a theoretical explanation for this surprising result, and demonstrate that this explanation is also suitable for the results found for entangled light. Furthermore, we discuss the limitations of these types of super sub-wavelength interference patterns in quantum lithography.

  12. Methodology for assessing probability of extreme hydrologic events coincidence

    Directory of Open Access Journals (Sweden)

    Prohaska Stevan

    2010-01-01

    Full Text Available The aim of the presented research is improvement of methodology for probability calculation of coinciding occurrence of historic floods and droughts in the same year. The original procedure was developed in order to determine the occurrence probability of such an extreme historic event. There are two phases in calculation procedure for assessment of both extreme drought and flood occurrence probability in the same year. In the first phase outliers are detected as indicators of extreme events, their return periods are calculated and series' statistics adjusted. In the second phase conditional probabilities are calculated: empirical points are plotted, and both extreme drought and flood occurrence probability in the same year is assessed based on the plot. Outlier detection is performed for the territory of Serbia. Results are shown as maps of regions (basins prone to floods, hydrologic drought, or both. Step-by-step numeric example is given for assessing conditional probability of occurrence of flood and drought for GS Raska on the river Raska. Results of assessment of conditional probability in two more cases are given for combination of extreme flood and 30 day minimum flow.

  13. The Structure of the Cubic Coincident Site Lattice Rotation Group

    Energy Technology Data Exchange (ETDEWEB)

    Reed, B W; Minich, R W; Rudd, R E; Kumar, M

    2004-01-13

    This work is intended to be a mathematical underpinning for the field of grain boundary engineering and its relatives. The interrelationships within the set of rotations producing coincident site lattices in cubic crystals are examined in detail. Besides combining previously established but widely scattered results into a unified context, the present work details newly developed representations of the group structure in terms of strings of generators (based on quaternionic number theory, and including uniqueness proofs and rules for algebraic manipulation) as well as an easily visualized topological network model. Important results that were previously obscure or not universally understood (e.g. the {Sigma} combination rule governing triple junctions) are clarified in these frameworks. The methods also facilitate several general observations, including the very different natures of twin-limited structures in two and three dimensions, the inadequacy of the {Sigma} combination rule to determine valid quadruple nodes, and a curious link between allowable grain boundary assignments and the four-color map theorem. This kind of understanding is essential to the generation of realistic statistical models of grain boundary networks (particularly in twin-dominated systems) and is especially applicable to the field of grain boundary engineering.

  14. Coincident Phosphatidic Acid Interaction Restrains Drp1 in Mitochondrial Division.

    Science.gov (United States)

    Adachi, Yoshihiro; Itoh, Kie; Yamada, Tatsuya; Cerveny, Kara L; Suzuki, Takamichi L; Macdonald, Patrick; Frohman, Michael A; Ramachandran, Rajesh; Iijima, Miho; Sesaki, Hiromi

    2016-09-15

    Mitochondria divide to control their size, distribution, turnover, and function. Dynamin-related protein 1 (Drp1) is a critical mechanochemical GTPase that drives constriction during mitochondrial division. It is generally believed that mitochondrial division is regulated during recruitment of Drp1 to mitochondria and its oligomerization into a division apparatus. Here, we report an unforeseen mechanism that regulates mitochondrial division by coincident interactions of Drp1 with the head group and acyl chains of phospholipids. Drp1 recognizes the head group of phosphatidic acid (PA) and two saturated acyl chains of another phospholipid by penetrating into the hydrophobic core of the membrane. The dual phospholipid interactions restrain Drp1 via inhibition of oligomerization-stimulated GTP hydrolysis that promotes membrane constriction. Moreover, a PA-producing phospholipase, MitoPLD, binds Drp1, creating a PA-rich microenvironment in the vicinity of a division apparatus. Thus, PA controls the activation of Drp1 after the formation of the division apparatus.

  15. Potential Mars 2001 Sites Coincident with Magnetic Anomalies

    Science.gov (United States)

    Gilmore, M. S.

    1999-01-01

    Of the areas that meet the engineering criteria for MSP 01, only two are coincident with magnetic anomalies measured by the MAG/ER instrument on MGS. Area A is centered on about 10 deg S, 202 deg W and extends from about 7.5 deg S to 15 S. This area is associated with three bands of magnetic anomalies, two with positive values surrounding an area with negative values. Area B corresponds with a circular high positive magnetic anomaly and is centered at 13.5 deg S, 166 deg W. In addition to magnetic anomalies, the proposed sites have other attributes that make then attractive from of standpoint of meeting the objectives of the Mars Program. The landing site candidates meet the engineering requirements outlined on the Mars '01 landing site page htip://mars.jpl.nasa.gov/2001/landingsite. These are (source of data in parentheses): latitude between 3 deg N and 12 deg S, rock abundance between 5-10% (IRTM), fine-component thermal inertia > 4 cgs units (IRTM), topography < 2.5 km (MOLA). There are three exceptions: 1) Area B contains sites that lie up to about 15 deg S, 2) some sites are considered that have rock abundance values of 3-13%. 3) High resolution Viking coverage may not be available. These exceptions will be noted.

  16. A Testable Solution of the Cosmological Constant and Coincidence Problems

    CERN Document Server

    Shaw, Douglas J

    2010-01-01

    We present a new solution to the cosmological constant (CC) and coincidence problems in which the observed value of the CC, Lambda, is linked to other observable properties of the universe. This is achieved by promoting the CC from a parameter which must to specified, to a field which can take many possible values. The observed value of Lambda = 1/(9.3 Gyrs)^2 (~ 10^(-120) in Planck units) is determined by a new constraint equation which follows from the application of a causally restricted variation principle. When applied to our visible universe, the model makes a testable prediction for the dimensionless spatial curvature of Omega_K0 = -0.0056 (s_b/0.5); where s_b ~ 1/2 is a QCD parameter. Requiring that a classical history exist, our model determines the probability of observing a given Lambda. The observed CC value, which we successfully predict, is typical within our model even before the effects of anthropic selection are included. When anthropic selection effects are accounted for, we find that the ob...

  17. Coincidence of Trisomy 18 and Robertsonian (13; 14

    Directory of Open Access Journals (Sweden)

    A Alavi

    2012-07-01

    Full Text Available This case report presents a coincidence of trisomy 18 and balanced Robertsonian translocation (13;14. Aneuploidy was suspected based on anomalies detected in ultrasound scan and confirmed with karyotype. In a 31 years-old healthy woman with a history of one miscarriage, second trimester ultrasound scan reported IUGR (<3rd percentile with normal amniotic fluid, bilateral choroid plexus cysts, suspicious agenesis of corpus callosum and clenched hands. Amniocentesis was performed and karyotype was 46xx,der(13;14 (q10;q10,+18. Maternal karyotype was 45xx,der(13;14(q10;q10. Pregnancy was continued due to legal limitation for termination after 20 weeks gestation. Delivery was done at 36 weeks gestation. A female newborn was borned and a physical feature was hypotonia, small mouth, prominent occiput, low-set and posteriorly rotated ears, clenched hands with overlapping fingers and rocker bottom feet. Ultrasound scan and echocardiography detected agenesis of corpus callosum and VSD, ASD, PDA and cardiomegaly. These features are typical of trisomy 18. Balanced Robertsonian translocation usually has no phenotypic expression. Genetic counseling and prenatal diagnosis for future pregnancy was recommended.

  18. Analytical model of coincidence resolving time in TOF-PET

    Science.gov (United States)

    Wieczorek, H.; Thon, A.; Dey, T.; Khanin, V.; Rodnyi, P.

    2016-06-01

    The coincidence resolving time (CRT) of scintillation detectors is the parameter determining noise reduction in time-of-flight PET. We derive an analytical CRT model based on the statistical distribution of photons for two different prototype scintillators. For the first one, characterized by single exponential decay, CRT is proportional to the decay time and inversely proportional to the number of photons, with a square root dependence on the trigger level. For the second scintillator prototype, characterized by exponential rise and decay, CRT is proportional to the square root of the product of rise time and decay time divided by the doubled number of photons, and it is nearly independent of the trigger level. This theory is verified by measurements of scintillation time constants, light yield and CRT on scintillator sticks. Trapping effects are taken into account by defining an effective decay time. We show that in terms of signal-to-noise ratio, CRT is as important as patient dose, imaging time or PET system sensitivity. The noise reduction effect of better timing resolution is verified and visualized by Monte Carlo simulation of a NEMA image quality phantom.

  19. Strings, boundary fermions and coincident D-branes

    CERN Document Server

    Wulff, L

    2007-01-01

    This thesis describes an attempt to write down covariant actions for coincident D-branes using so-called boundary fermions instead of matrices to describe the non-abelian fields. These fermions can be thought of as Chan-Paton degrees of freedom for the open string. It is shown that by gauge-fixing and by suitably quantizing these boundary fermions the non-abelian action that is known, the Myers action, can be reproduced. Furthermore it is shown that under natural assumptions, unlike the Myers action, the action formulated using boundary fermions also posseses kappa-symmetry when formulated on superspace. Another aspect of string theory discussed in this thesis is that of tensionless strings. These are of great interest for example because of their possible relation to higher spin gauge theories via the AdS/CFT-correspondence. The tensionless superstring in a plane wave background, a Penrose limit of the near-horizon geometry of a stack of D3-branes, is considered and compared to the tensile case.

  20. Coincidence symptomatic gall stone and helicobacter pylori: a brief report

    Directory of Open Access Journals (Sweden)

    Seyed Kazem Nezam

    2013-10-01

    Full Text Available Background: On of the most common gasterointrestinal disease is gallstone disease and it`s prevalence is 11%-36%in autopsies. If gallstone leads to symptoms and side effect cholecystectomy will be inevitable. Gastric infection due to H.P will cause several symptoms of which dyspepsia and epigastric pain are outstanding .Gall stones also usually causes epigastric and/or right upper quadrant pain. Pain in other abdominal quadrant is less common. In this study we investigated the coincidence of gall stone and gastro intestinal H.P regarding the common symptom, between these two conditions to prevent unnecessary operation.Methods: The cases were adopted from cholecystectomy candidates due to gall stone disease (proved by ultrasonography. The control group were normal people who proved to be gall stone free ultrasonographicly. Serum IgG anti H.P was checked and compared between the two groups.Results: Seventy percent of patients entered into the study which consisted of 35 case and 35 controls. The two groups were not significantly different in age and gender. There were 22 (68.8% and 10 (31.2% H.P positive cases in case and control groups respectively. Thirteen (34.2% and 25 (65.8% cases were H.P negative in case and control groups respectively. Comparing these results will reveal a statistically significant difference (P=0.004.Conclusion: The relationship between gastric H.P and gall stone in this study supports the role of H.P in gall stone formation. According to our results and the common symptoms of two conditions specially in atypic biliary colic, it seems that in many cases gastrointestinal H.P causes the pain. Prospective studies are recommended.

  1. The optimum choice of gate width for neutron coincidence counting

    Energy Technology Data Exchange (ETDEWEB)

    Croft, S., E-mail: crofts@ornl.gov [Safeguards and Security Technology (SST), Global Nuclear Security Technology Divisions, PO Box 2008, Building 5700, MS-6166, Oak Ridge, TN 37831-6166 (United States); Henzlova, D.; Favalli, A.; Hauck, D.K.; Santi, P.A. [Safeguards Science and Technology Group (NEN-1), Nuclear Engineering and Nonproliferation Division, MS-E540, Los Alamos, NM 87545 (United States)

    2014-11-11

    In the measurement field of international nuclear safeguards, passive neutron coincidence counting is used to quantify the spontaneous fission rate of certain special nuclear materials. The shift register autocorrelation analysis method is the most commonly used approach. However, the Feynman-Y technique, which is more commonly applied in reactor noise analysis, provides an alternative means to extract the correlation information from a pulse train. In this work we consider how to select the optimum gate width for each of these two time-correlation analysis techniques. The optimum is considered to be that which gives the lowest fractional precision on the net doublets rate. Our theoretical approach is approximate but is instructional in terms of revealing the key functional dependence. We show that in both cases the same performance figure of merit applies so that common design criteria apply to the neutron detector head. Our prediction is that near optimal results, suitable for most practical applications, can be obtained from both techniques using a common gate width setting. The estimated precision is also comparable in the two cases. The theoretical expressions are tested experimentally using {sup 252}Cf spontaneous fission sources measured in two thermal well counters representative of the type in common use by international inspectorates. Fast accidental sampling was the favored method of acquiring the Feynman-Y data. Our experimental study confirmed the basic functional dependences predicted although experimental results when available are preferred. With an appropriate gate setting Feynman-Y analysis provides an alternative to shift register analysis for safeguards applications which is opening up new avenues of data collection and data reduction to explore.

  2. The optimum choice of gate width for neutron coincidence counting

    Science.gov (United States)

    Croft, S.; Henzlova, D.; Favalli, A.; Hauck, D. K.; Santi, P. A.

    2014-11-01

    In the measurement field of international nuclear safeguards, passive neutron coincidence counting is used to quantify the spontaneous fission rate of certain special nuclear materials. The shift register autocorrelation analysis method is the most commonly used approach. However, the Feynman-Y technique, which is more commonly applied in reactor noise analysis, provides an alternative means to extract the correlation information from a pulse train. In this work we consider how to select the optimum gate width for each of these two time-correlation analysis techniques. The optimum is considered to be that which gives the lowest fractional precision on the net doublets rate. Our theoretical approach is approximate but is instructional in terms of revealing the key functional dependence. We show that in both cases the same performance figure of merit applies so that common design criteria apply to the neutron detector head. Our prediction is that near optimal results, suitable for most practical applications, can be obtained from both techniques using a common gate width setting. The estimated precision is also comparable in the two cases. The theoretical expressions are tested experimentally using 252Cf spontaneous fission sources measured in two thermal well counters representative of the type in common use by international inspectorates. Fast accidental sampling was the favored method of acquiring the Feynman-Y data. Our experimental study confirmed the basic functional dependences predicted although experimental results when available are preferred. With an appropriate gate setting Feynman-Y analysis provides an alternative to shift register analysis for safeguards applications which is opening up new avenues of data collection and data reduction to explore.

  3. Coincident Observations of Surface Ozone and NMVOCs over Abu Dhabi

    Science.gov (United States)

    Abbasi, Naveed; Majeed, Tariq; Iqbal, Mazhar; Tarasick, David; Davies, Jonathan; Riemer, Daniel; Apel, Eric

    2016-07-01

    The vertical profiles of ozone are measured coincidently with non-methane volatile organic compounds (NMVOCs) at the meteorological site located at the Abu Dhabi international airport (latitude 24.45N; longitude 54.22E) during the years 2012 - 2014. Some of the profiles show elevated surface ozone >95 ppbv during the winter months (December, January and February). The ground-level NMVOCs obtained from the gas chromatography-flame ionization detection/mass spectrometry system also show elevated values of acetylene, ethane, propane, butane, pentane, benzene, and toluene. NMVOCs and ozone abundances in other seasons are much lower than the values in winter season. NMVOCs are emitted from an extensive number of sources in urban environments including fuel production, distribution, and consumption, and serve as precursor of ozone. Transport sources contribute a substantial portion of the NMVOC burden to the urban atmosphere in developed regions. Abu Dhabi is located at the edge of the Arabian Gulf and is highly affected by emissions from petrochemical industries in the neighboring Gulf region. The preliminary results indicate that wintertime enhancement in ozone is associated with large values of NMVOCs at Abu Dhabi. The domestic production of surface ozone is estimated from the combination of oxygen recombination and NMVOCs and compared with the data. It is estimated that about 40-50% of ozone in Abu Dhabi is transported from the neighbouring petrochemical industries. We will present ozone sounding and NMVOCs data and our model estimates of surface ozone, including a discussion on the high levels of the tropospheric ozone responsible for contaminating the air quality in the UAE. This work is supported by National Research Foundation, UAE.

  4. Coincidence and covariance data acquisition in photoelectron and -ion spectroscopy. II. Analysis and applications

    Science.gov (United States)

    Mikosch, Jochen; Patchkovskii, Serguei

    2013-10-01

    We use an analytical theory of noisy Poisson processes, developed in the preceding companion publication, to compare coincidence and covariance measurement approaches in photoelectron and -ion spectroscopy. For non-unit detection efficiencies, coincidence data acquisition (DAQ) suffers from false coincidences. The rate of false coincidences grows quadratically with the rate of elementary ionization events. To minimize false coincidences for rare event outcomes, very low event rates may hence be required. Coincidence measurements exhibit high tolerance to noise introduced by unstable experimental conditions. Covariance DAQ on the other hand is free of systematic errors as long as stable experimental conditions are maintained. In the presence of noise, all channels in a covariance measurement become correlated. Under favourable conditions, covariance DAQ may allow orders of magnitude reduction in measurement times. Finally, we use experimental data for strong-field ionization of 1,3-butadiene to illustrate how fluctuations in experimental conditions can contaminate a covariance measurement, and how such contamination can be detected.

  5. The basis for design and manufacture of a dsp-based coincidence spectrometer

    CERN Document Server

    Hai, N X; Dien, N N; Lanh, D; Huong, T T T; Khang, P D

    2013-01-01

    The coincidence technique and the coincidence spectroscopy have been developed and applied for over 40 years. Most of popular coincidence measurement systems were based on analog electronics techniques such as time to amplitude conversion (TAC) or logic selecting coincidence unit. The above-mentioned systems are relatively cumbersome and complicated to use. With the strong growth of digital electronics techniques and computational science, the coincidence measurement systems will be constructed simpler but more efficient with the sake of application. This article presents the design principle and signal processing of a simple two-channel coincidence system by a technique of Digital Signal Processing (DSP) using Field Programmable Gate Arrays (FPGA) devices at Nuclear Research Institute (NRI), Dalat.

  6. Elemental PGNAA analysis using gamma-gamma coincidence counting with the library least-squares approach

    Science.gov (United States)

    Metwally, Walid A.; Gardner, Robin P.; Mayo, Charles W.

    2004-01-01

    An accurate method for determining elemental analysis using gamma-gamma coincidence counting is presented. To demonstrate the feasibility of this method for PGNAA, a system of three radioisotopes (Na-24, Co-60 and Cs-134) that emit coincident gamma rays was used. Two HPGe detectors were connected to a system that allowed both singles and coincidences to be collected simultaneously. A known mixture of the three radioisotopes was used and data was deliberately collected at relatively high counting rates to determine the effect of pulse pile-up distortion. The results obtained, with the library least-squares analysis, of both the normal and coincidence counting are presented and compared to the known amounts. The coincidence results are shown to give much better accuracy. It appears that in addition to the expected advantage of reduced background, the coincidence approach is considerably more resistant to pulse pile-up distortion.

  7. The coincidence of IgA nephropathy and Fabry disease

    Directory of Open Access Journals (Sweden)

    Maixnerová Dita

    2013-01-01

    Full Text Available Abstract Background IgA nephropathy (IgAN is the most common glomerulonephritis, which may also coexist with other diseases. We present two patients with an unusual coincidence of IgAN and Fabry disease (FD. Case presentation A 26 year-old man underwent a renal biopsy in February 2001. Histopathology showed very advanced IgAN and vascular changes as a result of hypertension. Because of his progressive renal insufficiency the patient began hemodialysis in August 2001. By means of the blood spot test screening method the diagnosis of FD was suspected. Low activity of alpha-galactosidase A in the patient’s plasma and leukocytes and DNA analysis confirmed the diagnosis of FD. Enzyme replacement therapy started in July 2004. Then the patient underwent kidney transplantation in November 2005. Currently, his actual serum creatinine level is 250 μmol/l. Other organ damages included hypertrophic cardiomyopathy, neuropathic pain and febrile crisis. After enzyme replacement therapy, myocardial hypertrophy has stabilized and other symptoms have disappeared. No further progression of the disease has been noted. The other patient, a 30 year-old woman, suffered from long-term hematuria with a good renal function. Recently, proteinuria (2.6 g/day appeared and a renal biopsy was performed. Histopathology showed IgAN with remarkably enlarged podocytes. A combination of IgAN and a high suspicion of FD was diagnosed. Electron microscopy revealed dense deposits in paramesangial areas typical for IgAN and podocytes with inclusive zebra bodies and myelin figures characteristic of FD. FD was confirmed by the decreased alpha-galactosidase A activity in plasma and leukocytes and by DNA and RNA analysis. Enzyme replacement therapy and family screening were initiated. Conclusions Our results emphasize the role of complexity in the process of diagnostic evaluation of kidney biopsy samples. Electron microscopy represents an integral part of histopathology, and genetic

  8. CHARGE Association

    Directory of Open Access Journals (Sweden)

    Semanti Chakraborty

    2012-01-01

    Full Text Available We present here a case of 17-year-old boy from Kolkata presenting with obesity, bilateral gynecomastia, mental retardation, and hypogonadotrophic hypogonadism. The patient weighed 70 kg and was of 153 cm height. Facial asymmetry (unilateral facial palsy, gynecomastia, decreased pubic and axillary hair, small penis, decreased right testicular volume, non-palpable left testis, and right-sided congenital inguinal hernia was present. The patient also had disc coloboma, convergent squint, microcornea, microphthalmia, pseudohypertelorism, low set ears, short neck, and choanalatresia. He had h/o VSD repaired with patch. Laboratory examination revealed haemoglobin 9.9 mg/dl, urea 24 mg/dl, creatinine 0.68 mg/dl. IGF1 77.80 ng/ml (decreased for age, GH <0.05 ng/ml, testosterone 0.25 ng/ml, FSH-0.95 ΅IU/ml, LH 0.60 ΅IU/ml. ACTH, 8:00 A.M cortisol, FT3, FT4, TSH, estradiol, DHEA-S, lipid profile, and LFT was within normal limits. Prolactin was elevated at 38.50 ng/ml. The patient′s karyotype was 46XY. Echocardiography revealed ventricularseptal defect closed with patch, grade 1 aortic regurgitation, and ejection fraction 67%. Ultrasound testis showed small right testis within scrotal sac and undescended left testis within left inguinal canal. CT scan paranasal sinuses revealed choanalatresia and deviation of nasal septum to the right. Sonomammography revealed bilateral proliferation of fibroglandular elements predominantly in subareoalar region of breasts. MRI of brain and pituitary region revealed markedly atrophic pituitary gland parenchyma with preserved infundibulum and hypothalamus and widened suprasellar cistern. The CHARGE association is an increasingly recognized non-random pattern of congenital anomalies comprising of coloboma, heart defect, choanal atresia, retarded growth and development, genital hypoplasia, ear abnormalities, and/or deafness. [1] These anomalies have a higher probability of occurring together. In this report, we have

  9. Coincidences and fixed points of reciprocally continuous and compatible hybrid maps

    Directory of Open Access Journals (Sweden)

    S. L. Singh

    2002-01-01

    Full Text Available It is proved that a pair of reciprocally continuous and nonvacuously compatible single-valued and multivalued maps on a metric space possesses a coincidence. Besides addressing two historical problems in fixed point theory, this result is applied to obtain new general coincidence and fixed point theorems for single-valued and multivalued maps on metric spaces under tight minimal conditions.

  10. Workplace Charging. Charging Up University Campuses

    Energy Technology Data Exchange (ETDEWEB)

    Giles, Carrie [ICF International, Fairfax, VA (United States); Ryder, Carrie [ICF International, Fairfax, VA (United States); Lommele, Stephen [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-01

    This case study features the experiences of university partners in the U.S. Department of Energy's (DOE) Workplace Charging Challenge with the installation and management of plug-in electric vehicle (PEV) charging stations.

  11. Search milli-charged particles at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Langeveld, W.G.J. [Stanford Univ., CA (United States)

    1997-01-01

    Particles with electric charge q {triple_bond} Qe {le} 10{sup -3} e and masses in the range 1-1000 MeV/c{sup 2} are not excluded by present experiments or by astrophysical or cosmological arguments. A beam dump experiment uniquely suited to the detection of such {open_quotes}milli-charged{close_quotes} particles has been carried out at SLAC, utilizing the short-duration pulses of the SLC electron beam to establish a tight coincidence window for the signal. The detector, a large scintillation counter sensitive to very small energy depositions, provided much greater sensitivity than previous searches. Analysis of the data leads to the exclusion of a substantial portion of the charge-mass plane. In this report, a preliminary mass-dependent upper limit is presented for the charge of milli-charged particles, ranging from Q = 1.7 x 10{sup -5} at milli-charged particle mass 0.1 MeV/c{sup 2} to Q = 9.5 x 10{sup -4} at 100 MeV/c{sup 2}.

  12. Experimental evidence for extreme surface sensitivity in Auger-Photoelectron Coincidence Spectroscopy (APECS) from solids

    Energy Technology Data Exchange (ETDEWEB)

    Liscio, A.; Gotter, R.; Ruocco, A.; Iacobucci, S.; Danese, A.G.; Bartynski, R.A.; Stefani, G

    2004-07-01

    Core hole creation and subsequent Auger decay processes are studied with unprecedented discrimination by Auger-Photoelectron Coincidence Spectroscopy (APECS). Early works in this field have already pointed out the intrinsic surface sensitivity of these experiments. However, it was not until recently that a model calculation was developed to quantitatively evaluate it. Here we present the first attempt to experimentally establish an effective target thickness for such experiments. The angular distribution of 3p{sub 3/2} photoelectron with kinetic energy of 160 eV is measured in coincidence with the M{sub 3}VV Auger electron with kinetic energy of 55 eV on a Cu (1 1 1) surface. Coincidence and non-coincidence photoelectron angular distributions display differences that, to large extent, are explained by confining the source of the coincident signal within the first two layers of Cu target, thus establishing an experimental upper limit for the effective target thickness of the APECS experiment.

  13. Multiple-coincidence of flood waves on the main river and its tributaries

    Science.gov (United States)

    Prohaska, S.; Ilic, A.; Majkic, B.

    2008-11-01

    This paper addresses the definition of multiple coincidences of flood waves on the main river and its tributaries. Contrary to previous studies of partial coincidences of various flood parameters (Prohaska 1999) for the main river and one of its tributaries, this procedure allows for the definition of complex (multiple) coincidences of a single parameter for the main river and several of its tributaries. In particular, coincidence is defined for the major parameter which characterizes a flood (i.e., the flood wave volume). The paper gives a practical example of the analysis of simultaneous flood waves on the Danube and its main tributaries in Serbia: the Tisa and the Sava rivers. The procedure for potential use of the established coincidence functions in applied water management and forecasting is also described in the paper.

  14. Primary 4πβ-γ coincidence system for standardization of radionuclides by means of plastic scintillators

    International Nuclear Information System (INIS)

    The present work describes a 4π(α,β)-γ coincidence system for absolute measurement of radionuclide activity using a plastic scintillator in 4π geometry for charged particles detection and a Nal (Tl) crystal for gamma-ray detection. Several shapes and dimensions of the plastic scintillator have been tried in order to obtain the best system configuration. Radionuclides which decay by alpha emission, β-, β+ and electron capture have been standardized. The results showed excellent agreement with other conventional primary system which makes use of a 4π proportional counter for X-ray and charged particle detection. The system developed in the present work have some advantages when compared with the conventional systems, namely; it does not need metal coating on the films used as radioactive source holders. When compared to liquid scintillators, is showed the advantage of not needing to be kept in dark for more than 24 h to allow phosphorescence decay of ambient light. Therefore it can be set to count immediately after the sources are placed inside of it. (author)

  15. Three-dimensional infinite order sudden quantum theory for indirect photodissociation processes. Application to the photofragment yield spectrum of NOCl in the region of the T1(13A″) ←S0(11A') transition. Fragment rotational distributions and thermal averages

    Science.gov (United States)

    Grinberg, Horacio; Freed, Karl F.; Williams, Carl J.

    1997-08-01

    The analytical infinite order sudden (IOS) quantum theory of triatomic photodissociation, developed in paper I, is applied to study the indirect photodissociation of NOCl through a real or virtual intermediate state. The theory uses the IOS approximation for the dynamics in the final dissociative channels and an Airy function approximation for the continuum functions. The transition is taken as polarized in the plane of the molecule; symmetric top wave functions are used for both the initial and intermediate bound states; and simple semiempirical model potentials are employed for each state. The theory provides analytical expressions for the photofragment yield spectrum for producing particular final fragment ro-vibrational states as a function of the photon excitation energy. Computations are made of the photofragment excitation spectrum of NOCl in the region of the T1(13A″)←S0(11A') transition for producing the NO fragment in the vibrational states nNO=0, 1, and 2. The computed spectra for the unexcited nNO==0 and excited nNO=2 states are in reasonable agreement with experiment. However, some discrepancies are observed for the singly excited nNO=1 vibrational state, indicating deficiencies in the semiempirical potential energy surface. Computations for two different orientations of the in-plane transition dipole moment produce very similar excitation spectra. Calculations of fragment rotational distributions are performed for high values of the total angular momentum J, a feature that would be very difficult to perform with close-coupled methods. Computations are also made of the thermally averaged rotational energy distributions to simulate the conditions in actual supersonic jet experiments.

  16. The IAEA neutron coincidence counting (INCC) and the DEMING least-squares fitting programs

    International Nuclear Information System (INIS)

    Two computer programs are described: (1) the INCC (IAEA or International Neutron Coincidence Counting) program and (2) the DEMING curve-fitting program. The INCC program is an IAEA version of the Los Alamos NCC (Neutron Coincidence Counting) code. The DEMING program is an upgrade of earlier Windows reg-sign and DOS codes with the same name. The versions described are INCC 3.00 and DEMING 1.11. The INCC and DEMING codes provide inspectors with the software support needed to perform calibration and verification measurements with all of the neutron coincidence counting systems used in IAEA inspections for the nondestructive assay of plutonium and uranium

  17. Determination of the time resolution for neutron scintillation detectors by multi-coincidence measurement

    Institute of Scientific and Technical Information of China (English)

    LI Yong-Ming; RUAN Xi-Chao; ZHOU Sin; MA Zhong-Yuan

    2011-01-01

    Based on the multi-coincidence measurement, the time resolution of three liquid scintillation detectors (BC501A) were determined strictly by solving the coincidence equations, where the influence from electronics estimated by self coincidence measurement as well as the background had been considered. The result of this work agreed well with the result that was deduced from the traditional method, and it will be helpful to analyze the energy resolution of neutron time of flight spectra measured by using such detectors at CIAE (China Institute of Atomic Energy).

  18. MULTIPLE IONIZATION PROCESS STUDIED WITH COINCIDENCE TECHNIQUE BETWEEN SLOW RECOIL ION AND PROJECTILE ION IN 42 MeV Arq+—Ar COLLISIONS

    Institute of Scientific and Technical Information of China (English)

    T.Tonuma; T.Matsuo; 等

    1990-01-01

    Slow Ar recoil ion Production cross sections by 42 MeV Ar1+(q=4-14) projectiles were measured using a projectile ion-recoilion coincidence technique in order to provide information on mechanisms of multiple ionization of target atome through pure ionization as well as of that accompaied simultaneously with multiple electron loss or capture of projectiles.The present results suggest that inner-shell electron processes caused through electron transfer into projectiles and also electron ionization by projectiles play a key role in the production of multiply charged recoil ions.

  19. Comparison of satellite reflectance algorithms for estimating chlorophyll-a in a temperate reservoir using coincident hyperspectral aircraft imagery and dense coincident surface observations

    Science.gov (United States)

    We analyzed 10 established and 4 new satellite reflectance algorithms for estimating chlorophyll-a (Chl-a) in a temperate reservoir in southwest Ohio using coincident hyperspectral aircraft imagery and dense water truth collected within one hour of image acquisition to develop si...

  20. Capability of analysis arsenic in geology sample by gamma-gamma coincidence method

    International Nuclear Information System (INIS)

    Gamma-gamma coincidence method has been successfully applied to the study of nuclear data and structure. Due to good abilities of background reduction, gamma-gamma coincidence method has been widely applied in neutron activation analysis. The experimental studies on geological and environmental samples have been conducted in several laboratories in the world. This report presents the results of Arsenic (As) analysis of geological sample by neutron activation analysis with coincidence method. The results show that the linearity between concentration in sample and count rate of peak in coincidence measurements and the influence of isotopes was eliminated and the background was reduced by application of this method in comparison with the conventional method that uses a detector. The results also found out that detection limits for analysis of As in geological samples were improved. (author)

  1. Calibration of nuclides by gamma-gamma sum peak coincidence counting

    International Nuclear Information System (INIS)

    The feasibility of extending sum peak coincidence counting to the direct calibration of gamma-ray emitters having particular decay schemes was investigated, also checkings of the measurement accuracy, by comparing with more precise beta-gamma coincidence counting have been performed. New theoretical studies and experiments were developed, demonstrating the reliability of the procedure. Uncertainties of less than one percent were obtained when certain radioactive sources were measured. The application of the procedure to 60Co, 22Na, 47Ca and 148Pm was studied. Theoretical bases of sum peak coincidence counting were set in order to extend it as an alternative method for absolute activity determination. In this respect, theoretical studies were performed for positive and negative beta decay, and electron capture, either accompanied or unaccompanied by coincident gamma rays. They include decay schemes containing up to three daughter nuclide excited levels, for different geometrical configurations. Equations are proposed for a possible generalization of the procedure. (M.E.L.)

  2. Shift Register Clock Rate Effects on Coincidence Collection 50MHz versus 4MHz Comparison Tests

    Energy Technology Data Exchange (ETDEWEB)

    Newell, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bourret, Steven C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Swinhoe, Martyn Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-03

    The following report identifies and quantifies the timing differences between the older slower Shift Register Coincidence/Multiplicity modules and today’s modern higher speed devices. Modern high speed Shift Register Coincidence/Multiplicity instruments employ high speed internal clocks that run at frequencies more than ten times the older units, typically 50MHz. These higher speed clocks allow for a finer time resolution when recording input pulses.

  3. Coincidence and covariance data acquisition in photoelectron and -ion spectroscopy. I. Formal theory

    Science.gov (United States)

    Mikosch, Jochen; Patchkovskii, Serguei

    2013-10-01

    We derive a formal theory of noisy Poisson processes with multiple outcomes. We obtain simple, compact expressions for the probability distribution function of arbitrarily complex composite events and its moments. We illustrate the utility of the theory by analyzing properties of coincidence and covariance photoelectron-photoion detection involving single-ionization events. The results and techniques introduced in this work are directly applicable to more general coincidence and covariance experiments, including multiple ionization and multiple-ion fragmentation pathways.

  4. Direction of an approaching stimulus on coincident timing performance of a ballistic striking task.

    Science.gov (United States)

    Coker, Cheryl A

    2005-06-01

    The purpose of this study was to explore the influence of stimulus direction and velocity on the coincident timing performance of a ballistic striking task. 26 subjects randomly performed 20 trials at each of two stimulus velocities (4 and 8 mph) and two striking variations (moving with an approaching stimulus or in opposition to it). Analysis indicated the direction of an approaching stimulus does not appear to influence the coincident timing of a ballistic striking action.

  5. The coincidence-summing correction of the Compton-suppression spectrometer.

    Science.gov (United States)

    Fan, Yuan-qing; Wang, Jun; Wang, Shi-lian; Zhang, Xin-jun; Li, Qi

    2012-09-01

    The compton-suppression Spectrometer can suppress the Compton baseline and make weak full energy peaks prominent in low-level activity gamma spectra, so it is used to measure environmental radioactive samples. In order to quantify the activities of the radionuclides in the sample coincidence-summing corrections should be applied. In this article the expressions of coincidence-summing correction of Compton-Suppression Spectrometer were deduced and the validity of the expressions was verified. PMID:22405959

  6. Magnetic charge quantisation and fractionally charged quarks

    NARCIS (Netherlands)

    Hooft, G. 't

    1976-01-01

    If magnetic monopoles with Schwinger's value of the magnetic charge would exist then that would pose serious restrictions on theories with fractionally charged quarks, even if they are confined. Weak and electromagnetic interactions must be unified with color, leading to a Weinberg angle w close to

  7. Multistep Charge Method by Charge Arrays

    Science.gov (United States)

    Segami, Go; Kusawake, Hiroaki; Shimizu, Yasuhiro; Iwasa, Minoru; Kibe, Koichi

    2008-09-01

    We studied reduction of the size and weight of the Power Control Unit (PCU). In this study, we specifically examined the weight of the Battery Charge Regulator (BCR), which accounts for half of the PCU weight for a low earth orbit (LEO) satellite. We found a multistep charge method by charge arrays and adopted a similar method for GEO satellites, thereby enabling the BCR reduction. We found the possibility of reducing the size and weight of PCU through more detailed design than that for a conventional PCU.BCRC1R1batterySAPower Control UnitBCRC1R1batterySAPower UnitHowever, this method decreases the state of charge (SOC) of the battery. Battery tests, a battery simulator test, and numerical analysis were used to evaluate the SOC decrease. We also studied effects of this method on the battery lifetime. The multistep charge method by charge arrays enabled charging to the same level of SOC as the conventional constant current/ constant voltage (CC/CV) charge method for a LEO satellite.

  8. On Dust Charging Equation

    OpenAIRE

    Tsintsadze, Nodar L.; Tsintsadze, Levan N.

    2008-01-01

    A general derivation of the charging equation of a dust grain is presented, and indicated where and when it can be used. A problem of linear fluctuations of charges on the surface of the dust grain is discussed.

  9. Induced Charge Capacitive Deionization

    OpenAIRE

    Rubin, S.; Suss, M. E.; Biesheuvel, P. M.; Bercovici, M.

    2016-01-01

    We demonstrate the phenomenon of induced-charge capacitive deionization (ICCDI) that occurs around a porous and conducting particle immersed in an electrolyte, under the action of an external electrostatic field. The external electric field induces an electric dipole in the porous particle, leading to capacitive charging of its volume by both cations and anions at opposite poles. This regime is characterized both by a large RC charging time and a small electrochemical charge relaxation time, ...

  10. New insight into the Auger decay process in O{sub 2}: The coincidence perspective

    Energy Technology Data Exchange (ETDEWEB)

    Arion, Tiberiu, E-mail: tiberiu.arion@cfel.de [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Institut fuer Experimentalphysik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Puettner, Ralph [Institut fuer Experimentalphysik, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin (Germany); Lupulescu, Cosmin [Technische Universitaet Berlin, Institut fuer Optik und atomare Physik, Hardenbergstr. 36, 10623 Berlin (Germany); Ovsyannikov, Ruslan [Helmholtz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Foerstel, Marko [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Oehrwall, Gunnar [MAX-lab, Lund University, P.O. Box 118, SE-22100 Lund (Sweden); Lindblad, Andreas [Uppsala University, Department of Physics and Astronomy, Box 516, SE-751 20 Uppsala (Sweden); Ueda, Kiyoshi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Svensson, Svante [Uppsala University, Department of Physics and Astronomy, Box 516, SE-751 20 Uppsala (Sweden); Bradshaw, Alex M. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany); Eberhardt, Wolfgang [Technische Universitaet Berlin, Institut fuer Optik und atomare Physik, Hardenbergstr. 36, 10623 Berlin (Germany); Center for Free-Electron Laser Science, Notkestrasse 85, 22607 Hamburg (Germany); and others

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We developed a new experimental set-up for e,e-coincidence experiments. Black-Right-Pointing-Pointer New information on the potential curves of the final states in O{sub 2} has been extracted. Black-Right-Pointing-Pointer We observed new features, assigned to autoionization of neutral doubly excited states. -- Abstract: Photoelectron-Auger electron coincidence spectroscopy is a powerful tool for the investigation of Auger decay processes with different core-ionized intermediate states. In this paper we describe an investigation into the Auger decay of the O{sub 2} molecule, with the purpose of bringing new insight into the dynamics of the core hole decay mechanism. Using a novel experimental approach to measuring such coincidence spectra we report the highest resolution Auger spectrum of O{sub 2} recorded hitherto. In our approach, we have combined the advantages of these coincidence spectra with the high resolution and excellent signal-to-noise ratios of non-coincident Auger spectra and a state-of-the-art fit analysis. In this way we have derived information about the potential energy curves of the final states W {sup 3}{Delta}{sub u}, B {sup 3}{Pi}{sub g}, and B Prime {sup 3}{Sigma}{sub u}{sup -} and concluded that the corresponding Auger transitions are formed to a large part by strongly overlapping vibrational progressions. The present findings are compared to earlier results reported in the literature confirming some theoretical predictions.

  11. The effect of deadtime and electronic transients on the predelay bias in neutron coincidence counting

    Science.gov (United States)

    Croft, Stephen; Favalli, Andrea; Swinhoe, Martyn T.; Goddard, Braden; Stewart, Scott

    2016-04-01

    In neutron coincidence counting using the shift register autocorrelation technique, a predelay is inserted before the opening of the (R+A)-gate. Operationally the purpose of the predelay is to ensure that the (R+A)- and A-gates have matched effectiveness, otherwise a bias will result when the difference between the gates is used to calculate the accidentals corrected net reals coincidence rate. The necessity for the predelay was established experimentally in the early practical development and deployment of the coincidence counting method. The choice of predelay for a given detection system is usually made experimentally, but even today long standing traditional values (e.g., 4.5 μs) are often used. This, at least in part, reflects the fact that a deep understanding of why a finite predelay setting is needed and how to control the underlying influences has not been fully worked out. In this paper we attempt to gain some insight into the problem. One aspect we consider is the slowing down, thermalization, and diffusion of neutrons in the detector moderator. The other is the influence of deadtime and electronic transients. These may be classified as non-ideal detector behaviors because they are not included in the conventional model used to interpret measurement data. From improved understanding of the effect of deadtime and electronic transients on the predelay bias in neutron coincidence counting, the performance of both future and current coincidence counters may be improved.

  12. Charge exchange system

    Science.gov (United States)

    Anderson, Oscar A.

    1978-01-01

    An improved charge exchange system for substantially reducing pumping requirements of excess gas in a controlled thermonuclear reactor high energy neutral beam injector. The charge exchange system utilizes a jet-type blanket which acts simultaneously as the charge exchange medium and as a shield for reflecting excess gas.

  13. High-level neutron-coincidence-counter (HLNCC) implementation: assay of the plutonium content of mixed-oxide fuel assemblies

    International Nuclear Information System (INIS)

    The portable High-Level Neutron Coincidence Counter is used to assay the 240Pu-effective loading of a reference mixed-oxide fuel assembly by neutron coincidence counting. We have investigated the effects on the coincidence count rate of the total fuel loading (UO2 + PuO2), the fissile loading, the fuel rod diameter, and the fuel rod pattern. The coincidence count rate per gram of 240Pu-effective per centimeter is primarily dependent on the total fuel loading of the assembly; the higher the loading, the higher the coincidence count rate. Detailed procedures for the assay of mixed-oxide fuel assemblies are developed

  14. Application of a simple asynchronous mechanical light chopper to multielectron coincidence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kenji; Suzuki, Isao H. [Photon Factory, IMSS, KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Penent, Francis; Lablanquie, Pascal [Universite Pierre et Marie Curie (UPMC), 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); CNRS, LCPMR(UMR 7614), 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Hikosaka, Yasumasa; Shigemasa, Eiji [UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan); Eland, John H. D. [PTCL, Oxford University, South Parks Road, Oxford OX1 3QZ (United Kingdom)

    2009-12-15

    A simple asynchronous mechanical light chopper, based on modification of a turbo-molecular pump, has been developed to extend the interval between light pulses in single bunch operation at the Photon Factory storage ring. A pulse repetition rate of 80 kHz was achieved using a cylinder rotating at 48000 rpm, with 100 slits of 80 {mu}m width. This allows absolute timing of particles up to 12.48 {mu}s instead of the single-bunch period of 624 ns. We have applied the chopper together with a light pulse monitor to measure multielectron coincidence spectra using a magnetic bottle time-of-flight electron spectrometer. With such a system, the electron energies are determined without any ambiguity, the folding of coincidence spectra disappears and the effect of false coincidences is drastically reduced.

  15. Search for transient gravitational waves in coincidence with short duration radio transients during 2007-2013

    CERN Document Server

    others,; Abbott, B P; Abbott, R; Abbott, T D; Abernathy, M R; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Adya, V B; Affeldt, C; Agathos, M; Agatsuma, K; Aggarwal, N; Aguiar, O D; Aiello, L; Ain, A; Ajith, P; Allen, B; Allocca, A; Altin, P A; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C C; Areeda, J S; Arnaud, N; Arun, K G; Ascenzi, S; Ashton, G; Ast, M; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Babak, S; Bacon, P; Bader, M K M; Baker, P T; Baldaccini, F; Ballardin, G; Ballmer, S W; Barayoga, J C; Barclay, S E; Barish, B C; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barta, D; Bartlett, J; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Baune, C; Bavigadda, V; Bazzan, M; Behnke, B; Bejger, M; Bell, A S; Bell, C J; Berger, B K; Bergman, J; Bergmann, G; Berry, C P L; Bersanetti, D; Bertolini, A; Betzwieser, J; Bhagwat, S; Bhandare, R; Bilenko, I A; Billingsley, G; Birch, J; Birney, R; Biscans, S; Bisht, A; Bitossi, M; Biwer, C; Bizouard, M A; Blackburn, J K; Blair, C D; Blair, D G; Blair, R M; Bloemen, S; Bock, O; Bodiya, T P; Boer, M; Bogaert, G; Bogan, C; Bohe, A; Bojtos, P; Bond, C; Bondu, F; Bonnand, R; Boom, B A; Bork, R; Boschi, V; Bose, S; Bouffanais, Y; Bozzi, A; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Brillet, A; Brinkmann, M; Brisson, V; Brockill, P; Brooks, A F; Brown, D A; Brown, D D; Brown, N M; Buchanan, C C; Buikema, A; Bulik, T; Bulten, H J; Buonanno, A; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Cahillane, C; Bustillo, J Calderón; Callister, T; Calloni, E; Camp, J B; Cannon, K C; Cao, J; Capano, C D; Capocasa, E; Carbognani, F; Caride, S; Diaz, J Casanueva; Casentini, C; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C B; Baiardi, L Cerboni; Cerretani, G; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chamberlin, S J; Chan, M; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, H Y; Chen, Y; Cheng, C; Chincarini, A; Chiummo, A; Cho, H S; Cho, M; Chow, J H; Christensen, N; Chu, Q; Chua, S; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Collette, C G; Cominsky, L; Constancio, M; Conte, A; Conti, L; Cook, D; Corbitt, T R; Cornish, N; Corsi, A; Cortese, S; Costa, C A; Coughlin, M W; Coughlin, S B; Coulon, J -P; Countryman, S T; Couvares, P; Coward, D M; Cowart, M J; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Cripe, J; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Canton, T Dal; Danilishin, S L; D'Antonio, S; Danzmann, K; Darman, N S; Dattilo, V; Dave, I; Daveloza, H P; Davier, M; Davies, G S; Daw, E J; Day, R; DeBra, D; Debreczeni, G; Degallaix, J; De Laurentis, M; Deléglise, S; Del Pozzo, W; Denker, T; Dent, T; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Dhurandhar, S; Díaz, M C; Di Fiore, L; Di Giovanni, M; Di Girolamo, T; Di Lieto, A; Di Pace, S; Di Palma, I; Di Virgilio, A; Dojcinoski, G; Dolique, V; Donovan, F; Dooley, K L; Doravari, S; Douglas, R; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Ducrot, M; Dwyer, S E; Edo, T B; Edwards, M C; Effler, A; Eggenstein, H -B; Ehrens, P; Eichholz, J; Eikenberry, S S; Engels, W; Essick, R C; Etzel, T; Evans, M; Evans, T M; Everett, R; Factourovich, M; Fafone, V; Fair, H; Fairhurst, S; Fan, X; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fays, M; Fehrmann, H; Fejer, M M; Ferrante, I; Ferreira, E C; Ferrini, F; Fidecaro, F; Fiori, I; Fiorucci, D; Fisher, R P; Flaminio, R; Fletcher, M; Fournier, J -D; Frasca, S; Frasconi, F; Frei, Z; Freise, A; Frey, R; Frey, V; Fricke, T T; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Gabbard, H A G; Gair, J R; Gammaitoni, L; Gaonkar, S G; Garufi, F; Gaur, G; Gehrels, N; Gemme, G; Genin, E; Gennai, A; George, J; Gergely, L; Germain, V; Ghosh, Archisman; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gill, K; Glaefke, A; Goetz, E; Goetz, R; Gondan, L; González, G; Castro, J M Gonzalez; Gopakumar, A; Gordon, N A; Gorodetsky, M L; Gossan, S E; Gosselin, M; Gouaty, R; Grado, A; Graef, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greco, G; Green, A C; Groot, P; Grote, H; Grunewald, S; Guidi, G M; Guo, X; Gupta, A; Gupta, M K; Gushwa, K E; Gustafson, E K; Gustafson, R; Hacker, J J; Hall, B R; Hall, E D; Hammond, G; Haney, M; Hanke, M M; Hanks, J; Hanna, C; Hannam, M D; Hanson, J; Hardwick, T; Harms, J; Harry, G M; Harry, I W; Hart, M J; Hartman, M T; Haster, C -J; Haughian, K; Heidmann, A; Heintze, M C; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Hennig, J; Heptonstall, A W; Heurs, M; Hild, S; Hoak, D; Hodge, K A; Hofman, D; Hollitt, S E; Holt, K; Holz, D E; Hopkins, P; Hosken, D J; Hough, J; Houston, E A; Howell, E J; Hu, Y M; Huang, S; Huerta, E A; Huet, D; Hughey, B; Husa, S; Huttner, S H; Huynh-Dinh, T; Idrisy, A; Indik, N; Ingram, D R; Inta, R; Isa, H N; Isac, J -M; Isi, M; Islas, G; Isogai, T; Iyer, B R; Izumi, K; Jacqmin, T; Jang, H; Jani, K; Jaranowski, P; Jawahar, S; Jiménez-Forteza, F; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalaghatgi, C V; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Karki, S; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, S; Kaur, T; Kawabe, K; Kawazoe, F; Kéfélian, F; Kehl, M S; Keitel, D; Kelley, D B; Kells, W; Kennedy, R; Key, J S; Khalaidovski, A; Khalili, F Y; Khan, I; Khan, S; Khan, Z; Khazanov, E A; Kijbunchoo, N; Kim, Chunglee; Kim, J; Kim, K; Kim, Nam-Gyu; Kim, Namjun; Kim, Y -M; King, E J; King, P J; Kinzel, D L; Kissel, J S; Kleybolte, L; Klimenko, S; Koehlenbeck, S M; Kokeyama, K; Koley, S; Kondrashov, V; Kontos, A; Korobko, M; Korth, W Z; Kowalska, I; Kozak, D B; Kringel, V; Królak, A; Krueger, C; Kuehn, G; Kumar, P; Kuo, L; Kutynia, A; Lackey, B D; Landry, M; Lange, J; Lantz, B; Lasky, P D; Lazzarini, A; Lazzaro, C; Leaci, P; Leavey, S; Lebigot, E O; Lee, C H; Lee, H K; Lee, H M; Lee, K; Lenon, A; Leonardi, M; Leong, J R; Leroy, N; Letendre, N; Levin, Y; Levine, B M; Li, T G F; Libson, A; Littenberg, T B; Lockerbie, N A; Logue, J; Lombardi, A L; Lord, J E; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J D; Lück, H; Lundgren, A P; Luo, J; Lynch, R; Ma, Y; MacDonald, T; Machenschalk, B; MacInnis, M; Macleod, D M; Magaña-Sandoval, F; Magee, R M; Mageswaran, M; Majorana, E; Maksimovic, I; Malvezzi, V; Man, N; Mandic, V; Mangano, V; Mansell, G L; Manske, M; Mantovani, M; Marchesoni, F; Marion, F; Márka, S; Márka, Z; Markosyan, A S; Maros, E; Martelli, F; Martellini, L; Martin, I W; Martin, R M; Martynov, D V; Marx, J N; Mason, K; Masserot, A; Massinger, T J; Masso-Reid, M; Mastrogiovanni, S; Matichard, F; Matone, L; Mavalvala, N; Mazumder, N; Mazzolo, G; McCarthy, R; McClelland, D E; McCormick, S; McGuire, S C; McIntyre, G; McIver, J; McManus, D J; McWilliams, S T; Meacher, D; Meadors, G D; Meidam, J; Melatos, A; Mendell, G; Mendoza-Gandara, D; Mercer, R A; Merilh, E L; Merzougui, M; Meshkov, S; Messenger, C; Messick, C; Metzdorff, R; Meyers, P M; Mezzani, F; Miao, H; Michel, C; Middleton, H; Mikhailov, E E; Milano, L; Miller, A L; Miller, J; Millhouse, M; Minenkov, Y; Ming, J; Mirshekari, S; Mishra, C; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Moggi, A; Mohan, M; Mohapatra, S R P; Montani, M; Moore, B C; Moore, C J; Moraru, D; Moreno, G; Morriss, S R; Mossavi, K; Mours, B; Mow-Lowry, C M; Mueller, C L; Mueller, G; Muir, A W; Mukherjee, Arunava; Mukherjee, D; Mukherjee, S; Mukund, K N; Mullavey, A; Munch, J; Murphy, D J; Murray, P G; Mytidis, A; Nardecchia, I; Naticchioni, L; Nayak, R K; Necula, V; Nedkova, K; Nelemans, G; Neri, M; Neunzert, A; Newton, G; Nguyen, T T; Nielsen, A B; Nissanke, S; Nitz, A; Nocera, F; Nolting, D; Normandin, M E N; Nuttall, L K; Oberling, J; Ochsner, E; O'Dell, J; Oelker, E; Ogin, G H; Oh, J J; Oh, S H; Ohme, F; Oliver, M; Oppermann, P; Oram, Richard J; O'Reilly, B; O'Shaughnessy, R; Ott, C D; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Pai, A; Pai, S A; Palamos, J R; Palashov, O; Palomba, C; Pal-Singh, A; Pan, H; Pankow, C; Pannarale, F; Pant, B C; Paoletti, F; Paoli, A; Papa, M A; Paris, H R; Parker, W; Pascucci, D; Pasqualetti, A; Passaquieti, R; Passuello, D; Patricelli, B; Patrick, Z; Pearlstone, B L; Pedraza, M; Pedurand, R; Pekowsky, L; Pele, A; Penn, S; Pereira, R; Perreca, A; Phelps, M; Piccinni, O J; Pichot, M; Piergiovanni, F; Pierro, V; Pillant, G; Pinard, L; Pinto, I M; Pitkin, M; Pletsch, H J; Poggiani, R; Popolizio, P; Post, A; Powell, J; Prasad, J; Predoi, V; Premachandra, S S; Prestegard, T; Price, L R; Prijatelj, M; Principe, M; Privitera, S; Prodi, G A; Prokhorov, L; Puncken, O; Punturo, M; Puppo, P; Pürrer, M; Qi, H; Qin, J; Quetschke, V; Quintero, E A; Quitzow-James, R; Raab, F J; Rabeling, D S; Radkins, H; Raffai, P; Raja, S; Rakhmanov, M; Rapagnani, P; Raymond, V; Razzano, M; Re, V; Read, J; Reed, C M; Regimbau, T; Rei, L; Reid, S; Reitze, D H; Rew, H; Ricci, F; Riles, K; Robertson, N A; Robie, R; Robinet, F; Rocchi, A; Rolland, L; Rollins, J G; Roma, V J; Romano, J D; Romano, R; Romanov, G; Romie, J H; Rosińska, D; Rowan, S; Rüdiger, A; Ruggi, P; Ryan, K; Sachdev, S; Sadecki, T; Sadeghian, L; Salconi, L; Saleem, M; Salemi, F; Samajdar, A; Sammut, L; Sanchez, E J; Sandberg, V; Sandeen, B; Sanders, J R; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Sauter, O E S; Savage, R L; Sawadsky, A; Schale, P; Schilling, R; Schmidt, J; Schmidt, P; Schnabel, R; Schofield, R M S; Schönbeck, A; Schreiber, E; Schuette, D; Schutz, B F; Scott, J; Scott, S M; Sellers, D; Sentenac, D; Sequino, V; Sergeev, A; Serna, G; Setyawati, Y; Sevigny, A; Shaddock, D A; Shahriar, M S; Shaltev, M; Shao, Z; Shapiro, B; Shawhan, P; Sheperd, A; Shoemaker, D H; Shoemaker, D M; Siellez, K; Siemens, X; Sieniawska, M; Sigg, D; Silva, A D; Simakov, D; Singer, A; Singer, L P; Singh, A; Singh, R; Singhal, A; Sintes, A M; Slagmolen, B J J; Smith, J R; Smith, N D; Smith, R J E; Son, E J; Sorazu, B; Sorrentino, F; Souradeep, T; Srivastava, A K; Staley, A; Steinke, M; Steinlechner, J; Steinlechner, S; Steinmeyer, D; Stephens, B C; Stiles, D; Stone, R; Strain, K A; Straniero, N; Stratta, G; Strauss, N A; Strigin, S; Sturani, R; Stuver, A L; Summerscales, T Z; Sun, L; Sutton, P J; Swinkels, B L; Szczepańczyk, M J; Tacca, M; Talukder, D; Tanner, D B; Tápai, M; Tarabrin, S P; Taracchini, A; Taylor, R; Theeg, T; Thirugnanasambandam, M P; Thomas, E G; Thomas, M; Thomas, P; Thorne, K A; Thrane, E; Tiwari, S; Tiwari, V; Tokmakov, K V; Tomlinson, C; Tonelli, M; Torres, C V; Torrie, C I; Töyrä, D; Travasso, F; Traylor, G; Trifirò, D; Tringali, M C; Trozzo, L; Tse, M; Turconi, M; Tuyenbayev, D; Ugolini, D; Unnikrishnan, C S; Urban, A L; Usman, S A; Vahlbruch, H; Vajente, G; Valdes, G; van Bakel, N; van Beuzekom, M; Brand, J F J van den; Broeck, C Van Den; Vander-Hyde, D C; van der Schaaf, L; van Heijningen, J V; van Veggel, A A; Vardaro, M; Vass, S; Vasúth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Vetrano, F; Viceré, A; Vinciguerra, S; Vine, D J; Vinet, J -Y; Vitale, S; Vo, T; Vocca, H; Vorvick, C; Voss, D V; Vousden, W D; Vyatchanin, S P; Wade, A R; Wade, L E; Wade, M; Walker, M; Wallace, L; Walsh, S; Wang, G; Wang, H; Wang, M; Wang, X; Wang, Y; Ward, R L; Warner, J; Was, M; Weaver, B; Wei, L -W; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Wessels, P; Westphal, T; Wette, K; Whelan, J T; Whitcomb, S E; White, D J; Whiting, B F; Williams, R D; Williamson, A R; Willis, J L; Willke, B; Wimmer, M H; Winkler, W; Wipf, C C; Wittel, H; Woan, G; Worden, J; Wright, J L; Wu, G; Yablon, J; Yam, W; Yamamoto, H; Yancey, C C; Yap, M J; Yu, H; Yvert, M; zny, A Zadro; Zangrando, L; Zanolin, M; Zendri, J -P; Zevin, M; Zhang, F; Zhang, L; Zhang, M; Zhang, Y; Zhao, C; Zhou, M; Zhou, Z; Zhu, X J; Zucker, M E; Zuraw, S E; Zweizig, J; Archibald, A M; Banaszak, S; Berndsen, A; Boyles, J; Cardoso, R F; Chawla, P; Cherry, A; Dartez, L P; Day, D; Epstein, C R; Ford, A J; Flanigan, J; Garcia, A; Hessels, J W T; Hinojosa, J; Jenet, F A; Karako-Argaman, C; Kaspi, V M; Keane, E F; Kondratiev, V I; Kramer, M; Leake, S; Lorimer, D; Lunsford, G; Lynch, R S; Martinez, J G; Mata, A; McLaughlin, M A; McPhee, C A; Penucci, T; Ransom, S; Roberts, M S E; Rohr, M D W; Stairs, I H; Stovall, K; van Leeuwen, J; Walker, A N; Wells, B L

    2016-01-01

    We present an archival search for transient gravitational wave bursts in coincidence with 27 single pulse triggers from Green Bank Telescope pulsar surveys, using the LIGO, Virgo and GEO interferometer network. We also discuss a check for gravitational wave signals in coincidence with Parkes Fast Radio Bursts using similar methods. Data analyzed in these searches were collected between 2007 and 2013. Possible sources of emission of both short duration radio signals andtransient gravitational wave emission include starquakes on neutron stars, binary coalescence of neutron stars, and cosmic string cusps. While no evidence for gravitational wave emission in coincidence with these radio transients was found, the current analysis serves as a prototype for similar future searches using more sensitive second generation interferometers.

  16. Simulations of Lithium-Based Neutron Coincidence Counter for Gd-Loaded Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Cowles, Christian C.; Kouzes, Richard T.; Siciliano, Edward R.

    2014-10-31

    The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Lithium-Based Alternative Neutron Detection Technology Coincidence Counting for Gd-loaded Fuels at Pacific Northwest National Laboratory for the development of a lithium-based neutron coincidence counter for nondestructively assaying Gd loaded nuclear fuel. This report provides results from MCNP simulations of a lithium-based coincidence counter for the possible measurement of Gd-loaded nuclear fuel. A comparison of lithium-based simulations and UNCL-II simulations with and without Gd loaded fuel is provided. A lithium-based model, referred to as PLNS3A-R1, showed strong promise for assaying Gd loaded fuel.

  17. Moisture corrections in neutron coincidence counting of PuO2

    International Nuclear Information System (INIS)

    Passive neutron coincidence counting is capable of 1% assay accuracy for pure, well-characterized PuO2 samples that contain plutonium masses from a few tens of grams to several kilograms. Moisture in the sample can significantly bias the assay high by changing the (α,n) neutron production, the sample multiplication, and the detection efficiency. Monte Carlo calculations and an analytical model of coincidence counting have been used to quantify the individual and cumulative effects of moisture biases for two PuO2 sample sizes and a range of moisture levels from 0 to 9 wt %. Results of the calculations suggest a simple correction procedure for moisture bias that is effective from 0 to 3 wt % H2O. The procedure requires that the moisture level in the sample be known before the coincidence measurement

  18. Two-dimensional diagonal summing of coincidence spectra for bulk PGNAA applications

    Energy Technology Data Exchange (ETDEWEB)

    Metwally, W.A.; Gardner, R.P. E-mail: gardner@ncsu.edu; Mayo, C.W

    2004-06-11

    In the past 10 years, new electronic devices have been developed that allow fast coincidence measurements to be performed that are capable of simultaneously recording the individual spectra as well as the coincidence spectra of multiple detectors. Utilizing these devices with computer software allows multiparameter data acquisition which adds much more flexibility in data analysis. One of the capabilities that is enabled is that of obtaining two-dimensional spectra. In this work, the use of this equipment and the two-dimensional spectra obtained with it are used to allow two-dimensional diagonal summing. The main advantages of this approach are improved peak resolution and very low background (Compton continuum). Possible uses of the two-dimensional diagonal summing are identifying coincidence schemes, performing elemental analysis, and identifying trace elements in bulk samples. The spectra obtained are very promising for these applications.

  19. Two-dimensional diagonal summing of coincidence spectra for bulk PGNAA applications

    Science.gov (United States)

    Metwally, W. A.; Gardner, R. P.; Mayo, C. W.

    2004-06-01

    In the past 10 years, new electronic devices have been developed that allow fast coincidence measurements to be performed that are capable of simultaneously recording the individual spectra as well as the coincidence spectra of multiple detectors. Utilizing these devices with computer software allows multiparameter data acquisition which adds much more flexibility in data analysis. One of the capabilities that is enabled is that of obtaining two-dimensional spectra. In this work, the use of this equipment and the two-dimensional spectra obtained with it are used to allow two-dimensional diagonal summing. The main advantages of this approach are improved peak resolution and very low background (Compton continuum). Possible uses of the two-dimensional diagonal summing are identifying coincidence schemes, performing elemental analysis, and identifying trace elements in bulk samples. The spectra obtained are very promising for these applications.

  20. Application of multiparameter coincidence spectrometry using a Ge detectors array to neutron activation analysis

    CERN Document Server

    Hatsukawa, Y; Hayakawa, T; Toh, Y; Shinohara, N

    2002-01-01

    The method of multiparameter coincidence spectrometry based on gamma-gamma coincidence is widely used for the nuclear structure studies, because of its high sensitivity to gamma-rays. In this study, feasibility of the method of multiparameter coincidence spectrometry for analytical chemistry was examined. Two reference igneous rock samples (JP-1, JB-1a) issued by the Geological Survey of Japan were irradiated at a research reactor, and the gamma-rays from the radioisotopes produced via neutron capture reactions were measured using an array of 12 Ge detectors with BGO Compton suppressors, GEMINI. Simultaneously 24 elements were analyzed without chemical separation. The observed smallest component was Eu contained in JP-1 with abundance of 4 ppb.

  1. Performance demonstration of 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme.

    Science.gov (United States)

    Kulkarni, D B; Anuradha, R; Joseph, Leena; Kulkarni, M S; Tomar, B S

    2016-02-01

    A standardization of (134)Cs and (131)I was carried out in order to demonstrate the performance and applicability of the 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme. The coincidence analyzer, capable of analyzing coincidence between beta and two gamma windows simultaneously, was developed and used for the standardization. The use of this dual coincidence analyzer has reduced the total experimental time by half. The activity concentrations obtained using the 4πβ(LS)-γ coincidence counting system, a 4πβ(PC)-γ coincidence counting system, and the CIEMAT/NIST method are in excellent agreement with each other within uncertainty limits and hence demonstrates its performance for standardization of radionuclides decaying with complex decay scheme. Hence use of this 4πβ(LS)-γ coincidence counting system can be an alternative method suitable to standardize radionuclides with complex decay scheme with acceptable precision.

  2. Space Charge Effects

    CERN Document Server

    Ferrario, M; Palumbo, L

    2014-01-01

    The space charge forces are those generated directly by the charge distribution, with the inclusion of the image charges and currents due to the interaction of the beam with a perfectly conducting smooth pipe. Space charge forces are responsible for several unwanted phenomena related to beam dynamics, such as energy loss, shift of the synchronous phase and frequency , shift of the betatron frequencies, and instabilities. We will discuss in this lecture the main feature of space charge effects in high-energy storage rings as well as in low-energy linacs and transport lines.

  3. Distinct coincidence detectors govern the corticostriatal spike timing-dependent plasticity.

    Science.gov (United States)

    Fino, Elodie; Paille, Vincent; Cui, Yihui; Morera-Herreras, Teresa; Deniau, Jean-Michel; Venance, Laurent

    2010-08-15

    Corticostriatal projections constitute the main input to the basal ganglia, an ensemble of interconnected subcortical nuclei involved in procedural learning. Thus, long-term plasticity at corticostriatal synapses would provide a basic mechanism for the function of basal ganglia in learning and memory. We had previously reported the existence of a corticostriatal anti-Hebbian spike timing-dependent plasticity (STDP) at synapses onto striatal output neurons, the medium-sized spiny neurons. Here, we show that the blockade of GABAergic transmission reversed the time dependence of corticostriatal STDP. We explored the receptors and signalling mechanisms involved in the corticostriatal STDP. Although classical models for STDP propose NMDA receptors as the unique coincidence detector, the involvement of multiple coincidence detectors has also been demonstrated. Here, we show that corticostriatal STDP depends on distinct coincidence detectors. Specifically, long-term potentiation is dependent on NMDA receptor activation, while long-term depression requires distinct coincidence detectors: the phospholipase Cbeta (PLCbeta) and the inositol-trisphosphate receptor (IP3R)-gated calcium stores. Furthermore, we found that PLCbeta activation is controlled by group-I metabotropic glutamate receptors, type-1 muscarinic receptors and voltage-sensitive calcium channel activities. Activation of PLCbeta and IP3Rs leads to robust retrograde endocannabinoid signalling mediated by 2-arachidonoyl-glycerol and cannabinoid CB1 receptors. Interestingly, the same coincidence detectors govern the corticostriatal anti-Hebbian STDP and the Hebbian STDP reported at cortical synapses. Therefore, LTP and LTD induced by STDP at corticostriatal synapses are mediated by independent signalling mechanisms, each one being controlled by distinct coincidence detectors. PMID:20603333

  4. Development of Monte Carlo code for coincidence prompt gamma-ray neutron activation analysis

    Science.gov (United States)

    Han, Xiaogang

    Prompt Gamma-Ray Neutron Activation Analysis (PGNAA) offers a non-destructive, relatively rapid on-line method for determination of elemental composition of bulk and other samples. However, PGNAA has an inherently large background. These backgrounds are primarily due to the presence of the neutron excitation source. It also includes neutron activation of the detector and the prompt gamma rays from the structure materials of PGNAA devices. These large backgrounds limit the sensitivity and accuracy of PGNAA. Since most of the prompt gamma rays from the same element are emitted in coincidence, a possible approach for further improvement is to change the traditional PGNAA measurement technique and introduce the gamma-gamma coincidence technique. It is well known that the coincidence techniques can eliminate most of the interference backgrounds and improve the signal-to-noise ratio. A new Monte Carlo code, CEARCPG has been developed at CEAR to simulate gamma-gamma coincidence spectra in PGNAA experiment. Compared to the other existing Monte Carlo code CEARPGA I and CEARPGA II, a new algorithm of sampling the prompt gamma rays produced from neutron capture reaction and neutron inelastic scattering reaction, is developed in this work. All the prompt gamma rays are taken into account by using this new algorithm. Before this work, the commonly used method is to interpolate the prompt gamma rays from the pre-calculated gamma-ray table. This technique works fine for the single spectrum. However it limits the capability to simulate the coincidence spectrum. The new algorithm samples the prompt gamma rays from the nucleus excitation scheme. The primary nuclear data library used to sample the prompt gamma rays comes from ENSDF library. Three cases are simulated and the simulated results are benchmarked with experiments. The first case is the prototype for ETI PGNAA application. This case is designed to check the capability of CEARCPG for single spectrum simulation. The second

  5. Probability for chance coincidence of a gamma-ray burst with a galaxy on the sky

    OpenAIRE

    Campisi, Maria Angela; Li, Li-Xin

    2008-01-01

    The nearby long GRB 060614 was not accompanied by a supernova, challenging the collapsar model for long-duration GRBs and the traditional classification scheme for GRBs. However, Cobb et al. have argued that the association of GRB 060614 and its host galaxy could be chance coincidence. In this work we calculate the probability for a GRB to be randomly coincident with a galaxy on the sky, using a galaxy luminosity function obtained from current galaxy surveys. We find that, with a magnitude li...

  6. LIGO Triggered Search for Coincidence with High Energy Photon Survey Missions

    Science.gov (United States)

    Camp, Jordan

    2009-01-01

    LIGO is about to begin a new, higher sensitivity science run, where gravitational detection is plausible. A possible candidate for detection is a compact binary merger, which would also be likely to emit a high energy electromagnetic signal. Coincident observation of the gw signal from a compact merger with an x-ray or gamma-ray signal would add considerable weight to the claim for gw detection. In this talk I will consider the possibility of using LIGO triggers with time and sky position to perform a coincident analysis of EM signals from the RXTE, SWIFT, and FERMI missions.

  7. Standardization of (99m)Tc by means of a software coincidence system.

    Science.gov (United States)

    Brito, A B; Koskinas, M F; Litvak, F; Toledo, F; Dias, M S

    2012-09-01

    The procedure followed by the Nuclear Metrology Laboratory, at IPEN, for the primary standardization of (99m)Tc is described. The primary standardization has been accomplished by the coincidence method. The beta channel efficiency was varied by electronic discrimination using a software coincidence counting system. Two windows were selected for the gamma channel: one at 140 keV gamma-ray and the other at 20 keV X-ray total absorption peaks. The experimental extrapolation curves were compared with Monte Carlo simulations by means of code ESQUEMA.

  8. Revolution of S-stars and oscillation of solar and terrestrial observables: nonrandom coincidence of periods

    CERN Document Server

    Rusov, V D; Eingorn, M V

    2015-01-01

    A striking coincidence of revolution periods of S-stars orbiting a supermassive black hole at the Galactic Center of the Milky Way and oscillation periods of such solar and terrestrial observables as the sunspot number, the geomagnetic field Y-component and the global temperature is established on basis of the corresponding experimental data. Rejecting randomness of this discovered coincidence, we put forward a hypothesis that modulation of dark matter flows in the Milky Way by the S-stars is responsible for such a frequency transfer from the Galactic Center to the Solar System.

  9. Coincidence techniques (time correlation) alpha-gamma particles associated experiments on PGFNAA

    International Nuclear Information System (INIS)

    PGFNAA (Prompt Gamma Fast Neutron Alpha Associated) techniques offers capabilities far beyond those of the conventional inspection system to detect hazardous materials such as explosives or drugs. This technique uses the time coincidence between alpha and gamma particles to reduce the background produced by fast neutron interactions not only with the objects but also with the surrounding material. This paper reports the experimental setup that have been conducted to capture coincident events between alpha and gamma particles. Although not perfect, but the reduction of the background almost 100 % had been obtained on the outside area of the spectrum energy interest for water and graphite samples. (author)

  10. Evaluation of a fast neutron coincidence counter for the measurements of uranium samples

    International Nuclear Information System (INIS)

    A fast neutron coincidence counter using BC454/BGO phoswich detectors has been evaluated for the purpose of rapid verification measurements of uranium items. This counter uses custom electronics to identify and count coincidence neutrons in the presence of background radiation. Measurements of uranium standards were performed to evaluate the counter. This counter is successful in measuring uranium items but has a low efficiency that results in minimal improvement over current technology. An optimized counter can be built with better performance capabilities, but it is recommended that newer technologies be used instead

  11. n-Tupled Coincidence Point Theorems for Probabilistic ψ-Contractions in Menger Spaces

    Directory of Open Access Journals (Sweden)

    Penumarthy Parvateesam Murthy

    2016-01-01

    Full Text Available We introduced n-tupled coincidence point for a pair of maps T:Xn→X and A:X→X in Menger space. Utilizing the properties of the pseudometric and the triangular norm, we will establish n-tupled coincidence point theorems under weak compatibility as well as n-tupled fixed point theorems for hybrid probabilistic ψ-contractions with a gauge function. Our main results do not require the conditions of continuity and monotonicity of ψ. At the end of this paper, an example is given to support our main theorem.

  12. Ion-coincidence momentum imaging of three-body Coulomb explosion of formaldehyde in ultrashort intense laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Fushitani, M.; Matsuda, A.; Hishikawa, A., E-mail: hishi@chem.nagoya-u.ac.jp [Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602 (Japan); Tseng, C.-M. [Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585 (Japan)

    2015-12-31

    Three-body Coulomb explosion of formaldehyde (H{sub 2}CO) in intense 7- and 35-fs laser fields (1.3 × 10{sup 15} W/cm{sup 2}) has been investigated by using ion-coincidence momentum imaging technique. Two types of explosion pathways from the triply charged state, H{sub 2}CO{sup 3+} → (i) H{sup +} + H{sup +} + CO{sup +} and (ii) H{sup +} + CH{sup +} + O{sup +}, have been identified. It is shown from the momentum correlation of the fragment ions of pathway (i), that the geometrical structure of the molecule is essentially frozen along the H-C-H bending coordinate for the 7-fs case. On the other hand, for a longer pulse duration (35 fs), structural deformation along the C-H stretching and H-C-H bending coordinates is identified, which is ascribed to the nuclear dynamics in the dication states populated within the laser pulse duration.

  13. Light charged particle emission in heavy-ion reactions – What have we learnt?

    Indian Academy of Sciences (India)

    S Kailas

    2001-07-01

    Light charged particles emitted in heavy-ion induced reactions, their spectra and angular distributions measured over a range of energies, carry the signature of the underlying reaction mechanisms. Analysis of data of light charged particles, both inclusive and exclusive measured in coincidence with gamma rays, fission products, evaporation residues have yielded interesting results which bring out the influence of nuclear structure, nuclear mean field and dynamics on the emission of these particles.

  14. Multiple scattering and accidental coincidences in the J-PET detector simulated using GATE package

    CERN Document Server

    Kowalski, P; Wiślicki, W; Raczyński, L; Bednarski, T; Białas, P; Bułka, J; Czerwiński, E; Gajos, A; Gruntowski, A; Kamińska, D; Kapłon, Ł; Kochanowski, A; Korcyl, G; Kowal, J; Kozik, T; Krzemień, W; Kubicz, E; Niedźwiecki, Sz; Pałka, M; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Słomski, A; Smyrski, J; Strzelecki, A; Wieczorek, A; Wochlik, I; Zieliński, M; Zoń, N

    2015-01-01

    Novel Positron Emission Tomography system, based on plastic scintillators, is developed by the J-PET collaboration. In order to optimize geometrical configuration of built device, advanced computer simulations are performed. Detailed study is presented of background given by accidental coincidences and multiple scattering of gamma quanta.

  15. Coincidence of the Universe Description Stemming from D-branes Theory and ENU Model

    OpenAIRE

    Sima, Jozef; Sukenik, Miroslav

    2001-01-01

    The contribution provides a comparison of consequences stemming from D-brane theories and Expansive Nondecelerative Universe model, and calls attention to coincidence of the results arising from the mentioned approaches to a description of the Universe. It follows from the comparison that the effects of quantum gravitation should appear at the energy near to 2 TeV.

  16. ALGEBRAICALLY CONSTRUCTED COSTAS ARRAYS WITH SMALL NUMBER OF CROSS-COINCIDENCES

    Institute of Scientific and Technical Information of China (English)

    YANG Yixian

    2000-01-01

    Eight families of Costas arrays with ideal cross-coincidence are algebraically constructed under the assumption that the vertical shifts are appropriately bounded. These Costas arrays are useful for designing multiple Costas waveforms with small crossambiguities, if the potential Doppler shifts are restricted to a small portion of the waveform bandwidth.

  17. Calculation of coincidence summing corrections for a specific small soil sample geometry

    Energy Technology Data Exchange (ETDEWEB)

    Helmer, R.G.; Gehrke, R.J.

    1996-10-01

    Previously, a system was developed at the INEL for measuring the {gamma}-ray emitting nuclides in small soil samples for the purpose of environmental monitoring. These samples were counted close to a {approx}20% Ge detector and, therefore, it was necessary to take into account the coincidence summing that occurs for some nuclides. In order to improve the technical basis for the coincidence summing corrections, the authors have carried out a study of the variation in the coincidence summing probability with position within the sample volume. A Monte Carlo electron and photon transport code (CYLTRAN) was used to compute peak and total efficiencies for various photon energies from 30 to 2,000 keV at 30 points throughout the sample volume. The geometry for these calculations included the various components of the detector and source along with the shielding. The associated coincidence summing corrections were computed at these 30 positions in the sample volume and then averaged for the whole source. The influence of the soil and the detector shielding on the efficiencies was investigated.

  18. Constructing coincident indices of economic activity for the Latin American economy

    Directory of Open Access Journals (Sweden)

    João Victor Issler

    2013-03-01

    Full Text Available This paper has three main contributions. The first is to propose an individual coincident indicator for the following Latin American countries: Argentina, Brazil, Chile, Colombia and Mexico. In order to obtain similar series to those traditionally used in business-cycle research in constructing coincident indices (output, sales, income and employment we were forced to back-cast several individual country series which were not available in a long time-series span. The second contribution is to establish a chronology of recessions for these countries, covering the period from 1980 to 2012 on a monthly basis. Based on this chronology, the countries are compared in several respects. The final contribution is to propose an aggregate coincident indicator for the Latin American economy, which weights individual-country composite indices. Finally, this indicator is compared with the coincident indicator (The Conference Board - TCB of the U.S. economy. We find that the U.S. indicator Granger-causes the Latin American indicator in statistical tests

  19. Internal Bremsstrahlung spectrum from 57Co in coincidence with K-X rays

    International Nuclear Information System (INIS)

    In the present study, the IB photons from 57Co are measured in coincidence with 6.4 keV x rays emitted due to the EC process. The IB photons are measured using a (1.75 x 2.0 ) NaI(Tl) scintillation detector and k-x rays are detected using a proportional counter

  20. Increased coincidence detection for quantum versus pseudo-generated random numbers

    NARCIS (Netherlands)

    Boshoff, Lieze; Jolij, Jacob

    2015-01-01

    People often see meaning in stimuli that are typically considered meaningless. According to Von Lucadou’s idea of Generalized Quantum Teory (GQT), such perceived coincidences, or examples of synchronicity, may be the result of entanglement between a conscious observer and the physical world. Here we

  1. Use of sum-peak and coincidence counting methods for activity standardization of {sup 22}Na

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, E.M. de, E-mail: estela@ird.gov.br [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes (LNMRI/IRD/CNEN), Av. Salvador Allende, s/n, Recreio, CEP 22780-160 Rio de Janeiro (Brazil); Iwahara, A.; Poledna, R. [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes (LNMRI/IRD/CNEN), Av. Salvador Allende, s/n, Recreio, CEP 22780-160 Rio de Janeiro (Brazil); Silva, M.A.L. da [Coordenacao Geral de Instalacoes Nucleares/Comissao Nacional de Energia Nuclear, R. Gal. Severiano, 90 - Botafogo, CEP 22290-901 Rio de Janeiro (Brazil); Tauhata, L. [Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ), Av. Erasmo Braga, 118-6 Degree-Sign andar, CEP 20020-000 Centro, Rio de Janeiro (Brazil); Delgado, J.U. [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes (LNMRI/IRD/CNEN), Av. Salvador Allende, s/n, Recreio, CEP 22780-160 Rio de Janeiro (Brazil); Lopes, R.T. [Laboratorio de Instrumentacao Nuclear (LIN/PEN/COPPE/UFRJ), Caixa Postal 68509, CEP 21945-970 Rio de Janeiro (Brazil)

    2012-09-21

    A solution containing the positron emitter {sup 22}Na has been absolutely standardized using the 4{pi}{beta}-{gamma} coincidence counting method and the sum-peak spectrometry counting method. In the 4{pi}{beta}-{gamma} coincidence method two ways for the activity concentration measurements were used: gating on the 1275 keV photopeak and on the 1786 keV sum-peak where the knowledge of the {beta}{sup +}-branching ratio is required. In the sum-peak method the measurements were carried out using three experimental arrangements: the first composed by a well type 5 in. Multiplication-Sign 5 in. NaI(Tl) scintillation crystal, the second by a 3 in. Multiplication-Sign 3 in. NaI(Tl) scintillation crystal placed on the top of the first, resulting in a 4{pi} counting geometry and the third arrangement is a high purity coaxial germanium detector. The results that are obtained by these two methods are compatible within the standard uncertainty values with a coverage factor of k=2 ({approx}95% of the confidence level). This means that the sum-peak counting with its more simple experimental setup than the complex coincidence 4{pi}{beta}-{gamma} counting system gives consistent results for the activity standardization of {sup 22}Na with smaller uncertainties. Besides, the time period involved to attain the result of the standardization was quite shorter than the coincidence measurements used in this work.

  2. Continuous Selection, Collectively Fixed Points and System of Coincidence Theorems in Product Topological Spaces

    Institute of Scientific and Technical Information of China (English)

    Xie Ping DING

    2006-01-01

    Some new continuous selection theorems are first proved in noncompact topological spaces.As applications, some new collectively fixed point theorems and coincidence theorems for two families of set-valued mappings defined on product space of noncompact topological spaces are obtained under very weak assumptions. These results generalize many known results in recent literature.

  3. SYSTEM OF COINCIDENCE THEOREMS IN PRODUCT TOPOLOGICAL SPACES AND APPLICATIONS (Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    DING Xie-ping

    2005-01-01

    By applying coincidence theorems in part ( Ⅰ ) for two families of setvalued mappings defined on product space of noncompact FC-spaces in preceding paper, some new existence theorems for system of vector equilibrium problems, system ofinequalities and system of minimax theorems were established in FC-spaces. These results generalize some known results in recent literature.

  4. Metformin and lactic acidosis : cause or coincidence? A review of case reports

    NARCIS (Netherlands)

    Stades, AME; Heikens, JT; Erkelens, DW; Holleman, F; Hoekstra, JBL

    2004-01-01

    Objective. Metformin has been associated with the serious side-effect lactic acidosis. However, it remains unclear whether the use of metformin was a cause or a coincidence in lactic acidosis. Design. A literature search of the Index Medicus (1959-66) and of the databases Embase, Medline, Medline Ex

  5. Some New Coincidence Theorems in Product GFC-Spaces with Applications

    Directory of Open Access Journals (Sweden)

    Jianrong Zhao

    2014-01-01

    Full Text Available We first propose a new concept of GFC-subspace. Using this notion, we obtain a new continuous selection theorem. As a consequence, we establish some new collective fixed point theorems and coincidence theorems in product GFC-spaces. Finally, we give some applications of our theorems.

  6. Some New Coincidence Theorems in Product GFC-Spaces with Applications

    OpenAIRE

    Jianrong Zhao

    2014-01-01

    We first propose a new concept of GFC-subspace. Using this notion, we obtain a new continuous selection theorem. As a consequence, we establish some new collective fixed point theorems and coincidence theorems in product GFC-spaces. Finally, we give some applications of our theorems.

  7. Design of a liquid scintillator-based prototype neutron coincidence counter for Nuclear Safeguards

    International Nuclear Information System (INIS)

    A liquid scintillator-based neutron coincidence counting system designed to address a number of safeguards applications is under development by the IAEA in collaboration with the Joint Research Centre-ITU and Hybrid Instruments LTD. Liquid scintillators are a promising technology due to their good fast-neutron detection capabilities. The characteristic fast response of scintillators is particularly beneficial for coincidence counting applications, for which a performance level higher than that associated with moderated thermal detectors might be expected. Fast neutron detection requires no thermalization process and therefore, does not incur the resulting neutron detection delays. These features reduce the length of the coincidence gate by three orders of magnitude, reducing practically to negligible values the accidental coincidence rate which dominates the uncertainty in thermal neutron detectors. Recent progress in fast electronic digitizers offers the possibility to perform on-line, real-time pulse shape discrimination (PSD) between gamma and neutron radiation detection, making this technology suitable for nuclear safeguards and security applications. This paper will describe the experiments and Monte Carlo modelling activities engaged to design a prototype liquid scintillator-based neutron coincidence collar for fresh fuel assembly verification. The characterization of the system response required accurate calibration measurements in order to determine the operational parameters of the liquid scintillator cell, including gain, pulse shape discrimination and energy thresholds. Extensive Monte Carlo simulations which are essential for the understanding and characterization of the system’s response were also carried out using the MCNPX-PoliMi Monte Carlo code to simulate the radiation transport within the system and to optimize the detector design. The evolution from the different detector configurations we investigated to the characteristic features of the

  8. The spallation in reverse kinematics: what for a coincidence measurement?; La spallation en cinematique inverse: pourquoi faire une mesure en coincidence?

    Energy Technology Data Exchange (ETDEWEB)

    Ducret, J.E

    2006-07-15

    The Spaladin installation has been designed to study spallation reactions in reverse kinematics. Furthermore, the heavy and light fragments are detected by coincidence which allows us to get an instantaneous picture of the reaction at a level of accuracy better than that obtained through inclusive measurement. The first part is dedicated to the theoretical description of the different mechanisms involved in the spallation reactions. In the second part we describe the Spaladin installation and report some results on the reaction: Fe{sup 56} + p at an energy of 1 GeV/nucleon. In the third part we expose the performance of the installation through its simulation with the Geant-IV model. We present a study about the sensitivity of the Spaladin installation to theoretical predictions. The fourth part is dedicated to the future experiments that will be performed with the Spaladin installation. (A.C.)

  9. Highly charged ion based time of flight emission microscope

    Science.gov (United States)

    Barnes, Alan V.; Schenkel, Thomas; Hamza, Alex V.; Schneider, Dieter H.; Doyle, Barney

    2001-01-01

    A highly charged ion based time-of-flight emission microscope has been designed, which improves the surface sensitivity of static SIMS measurements because of the higher ionization probability of highly charged ions. Slow, highly charged ions are produced in an electron beam ion trap and are directed to the sample surface. The sputtered secondary ions and electrons pass through a specially designed objective lens to a microchannel plate detector. This new instrument permits high surface sensitivity (10.sup.10 atoms/cm.sup.2), high spatial resolution (100 nm), and chemical structural information due to the high molecular ion yields. The high secondary ion yield permits coincidence counting, which can be used to enhance determination of chemical and topological structure and to correlate specific molecular species.

  10. Induced Charge Capacitive Deionization

    CERN Document Server

    Rubin, S; Biesheuvel, P M; Bercovici, M

    2016-01-01

    We demonstrate the phenomenon of induced-charge capacitive deionization (ICCDI) that occurs around a porous and conducting particle immersed in an electrolyte, under the action of an external electrostatic field. The external electric field induces an electric dipole in the porous particle, leading to capacitive charging of its volume by both cations and anions at opposite poles. This regime is characterized both by a large RC charging time and a small electrochemical charge relaxation time, which leads to rapid and significant deionization of ionic species from a volume which is on the scale of the particle. We show by theory and experiment that the transient response around a cylindrical particle results in spatially non-uniform charging and non-steady growth of depletion regions which emerge around the particle's poles. Potentially, ICCDI can be useful in applications where fast concentration changes of ionic species are required over large volumes.

  11. A remark on the asymptotic form of BPS multi-dyon solutions and their conserved charges

    Science.gov (United States)

    Constantinidis, C. P.; Ferreira, L. A.; Luchini, G.

    2015-12-01

    We evaluate the gauge invariant, dynamically conserved charges, recently obtained from the integral form of the Yang-Mills equations, for the BPS multi-dyon solutions of a Yang-Mills-Higgs theory associated to any compact semi-simple gauge group G. Those charges are shown to correspond to the eigenvalues of the next-to-leading term of the asymptotic form of the Higgs field at spatial infinity, and so coinciding with the usual topological charges of those solutions. Such results show that many of the topological charges considered in the literature are in fact dynamical charges, which conservation follows from the global properties of classical Yang-Mills theories encoded into their integral dynamical equations. The conservation of those charges can not be obtained from the differential form of Yang-Mills equations.

  12. A remark on the asymptotic form of BPS multi-dyon solutions and their conserved charges

    CERN Document Server

    Constantinidis, C P; Luchini, G

    2015-01-01

    We evaluate the gauge invariant, dynamically conserved charges, recently obtained from the integral form of the Yang-Mills equations, for the BPS multi-dyon solutions of a Yang-Mills-Higgs theory associated to any compact semi-simple gauge group G. Those charges are shown to correspond to the eigenvalues of the next-to-leading term of the asymptotic form of the Higgs field at spatial infinity, and so coinciding with the usual topological charges of those solutions. Such results show that many of the topological charges considered in the literature are in fact dynamical charges, which conservation follows from the global properties of classical Yang-Mills theories encoded into their integral dynamical equations. The conservation of those charges can not be obtained from the differential form of Yang-Mills equations.

  13. A thin 4πβ-counter operating by negative high voltage for the 4πβ-γ coincidence measurement

    International Nuclear Information System (INIS)

    A thin 4πβ-multiwire proportional counter was constructed to increase the γ-ray counting efficiency in the 4πβ-γ coincidence method. This counter with a counting volume of 70 x 60 x 11 mm and 5 wires in one half was made of an insulator and negative high voltage was supplied to the inner wall being possessed of conductivity. Then the anodes were operated at the earth potential and compact preamplifiers with no coupling condenser were fixed at the side of each half to miniaturize a shielding system for background. From the experimental results in various conditions, good characteristics were obtained in the case that signals were taken out from the center anode and the others were used only for cleaning up excess charges. (auth.)

  14. Safeguards Technology Factsheet 3He-free Neutron Coincidence Counter

    Energy Technology Data Exchange (ETDEWEB)

    Henzlova, Daniela [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Menlove, Howard Olsen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-21

    A full scale thermal neutron coincidence counter (High Level Neutron Counter – Boron: HLNB) based on 3He alternative detection technology was designed and built at LANL and field tested at Plutonium Conversion Development Facility (PCDF) of Japan Atomic Energy Agency (JAEA) during FY15. HLNB is based on boron-lined proportional plates that replace the traditional 3He proportional tubes and was designed as a direct alternative to 3He-based High Level Neutron Coincidence Counter (HLNC-II). During the JAEA field trial the HLNB demonstrated comparable performance to HLNC-II, which represents a key development in the area of 3He alternative technologies and provides a complete demonstration of the technology for nuclear safeguards applications including high mass MOX samples.

  15. A comparison of cloud motion winds from ATS 6 images with coinciding SMS 1 winds

    Science.gov (United States)

    Kuhlow, W. W.; Chatters, G. C.

    1978-01-01

    A methodology is developed for accurate measurement of cloud motion winds from the geosynchronous ATS 6 image data. Attitude changes between consecutive images (as a function of scan-line number) are accounted for in wind computations through measurement of the earth-edge displacements between the successive infrared images. Also, an image matching procedure is used to remove obvious and distracting image distortions. The availability of SMS imagery coinciding with ATS 6 imagery makes SMS an excellent reference against which the quality of ATS 6 winds can be tested. The resulting winds inferred from cloud displacement measurements taken from a sequence of the corrected images are found to agree better than 2 m/sec rms with winds measured from coincident SMS 1 imagery.

  16. Coincident site lattice-matched InGaN on (111) spinel substrates

    International Nuclear Information System (INIS)

    Coincident site lattice-matched wurtzite (0001) In0.31Ga0.69N, emitting in the important green wavelength region, is demonstrated by molecular beam epitaxy on a cubic (111) MgAl2O4 spinel substrate. The coincident site lattice matching condition involves a 30 deg. rotation between the lattice of the InGaN epitaxial layer and the lattice of the spinel. This work describes an alternative approach towards realizing more compositionally homogenous InGaN films with low dislocation density emitting in the ''green gap'' of low efficiency currently observed for semiconductor light emitting diodes (LEDs). This approach could lead to higher efficiency green LEDs presently of great interest for solid-state lighting applications.

  17. Angular distribution measurements in particle-γ coincidences using SONIC and HORUS

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelmy, Julius; Derya, Vera; Hennig, Andreas; Pickstone, Simon G.; Spieker, Mark; Zilges, Andreas [Institute for Nuclear Physics, University of Cologne (Germany)

    2014-07-01

    The combined setup SONIC and HORUS consists of the γ-ray spectrometer HORUS with 14 HPGe detectors and the recently commissioned particle spectrometer SONIC with up to 8 ΔE-E silicon detectors. This setup is used to measure the ejectile of a nuclear reaction (p, d, t, or α) in coincidence with the deexciting γ rays emitted by the recoil nucleus. By requiring a certain ejectile energy (e.g. the excitation of a level), a very clean γ spectrum is obtained, in which only physically related events remain. Measuring the angular correlations between the coincident ejectiles and γ-rays allows spin assignments to excited nuclear levels by comparison to theoretical particle-γ angular correlations. An overview of the experimental setup is given, and preliminary p-γ angular correlations measured in a recent {sup 92}Mo(p,p'γ) experiment are shown.

  18. Digital coincidence acquisition applied to portable β liquid scintillation counting device

    International Nuclear Information System (INIS)

    A digital coincidence acquisition system applied to a portable liquid scintillation counting device is developed. The system which simplifies the device design consists of a digitizer card of Agilent U1066A DC438, a discriminator and a host computer. The anode analog pulses from two photomultiplier tubes are captured by the system, which adopts the sequence acquisition storage mode. By choosing proper threshold for each channel, coincidence time window of ±30 ns, and comparing the pulse amplitudes from two channels, the portable scintillation counting device can be used to detect β particles. For the unquenched standard 3H sample, the results show that the detection efficiency is (58.5±0.1)% and the background is (86.7±0.7) cpm. Meanwhile, 3H β spectrum is obtained. (authors)

  19. Coincidence and coherent data analysis methods for gravitational wave bursts in a network of interferometric detectors

    CERN Document Server

    Arnaud, N; Bizouard, M A; Brisson, V; Cavalier, F; Davier, M; Hello, P; Kreckelberg, S; Porter, E K; Arnaud, Nicolas; Barsuglia, Matteo; Bizouard, Marie-Anne; Brisson, Violette; Cavalier, Fabien; Davier, Michel; Hello, Patrice; Kreckelberg, Stephane; Porter, Edward K.

    2003-01-01

    Network data analysis methods are the only way to properly separate real gravitational wave (GW) transient events from detector noise. They can be divided into two generic classes: the coincidence method and the coherent analysis. The former uses lists of selected events provided by each interferometer belonging to the network and tries to correlate them in time to identify a physical signal. Instead of this binary treatment of detector outputs (signal present or absent), the latter method involves first the merging of the interferometer data and looks for a common pattern, consistent with an assumed GW waveform and a given source location in the sky. The thresholds are only applied later, to validate or not the hypothesis made. As coherent algorithms use a more complete information than coincidence methods, they are expected to provide better detection performances, but at a higher computational cost. An efficient filter must yield a good compromise between a low false alarm rate (hence triggering on data at...

  20. SPADnet: Embedded coincidence in a smart sensor network for PET applications

    Energy Technology Data Exchange (ETDEWEB)

    Bruschini, C., E-mail: claudio.bruschini@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Charbon, E. [Delft University of Technology, Delft (Netherlands); Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Veerappan, C. [Delft University of Technology, Delft (Netherlands); Braga, L.H.C.; Massari, N.; Perenzoni, M.; Gasparini, L.; Stoppa, D. [Fondazione Bruno Kessler (FBK), Trento (Italy); Walker, R.; Erdogan, A.; Henderson, R.K. [University of Edinburgh, Edinburgh (United Kingdom); East, S.; Grant, L. [STMicroelectronics (R and D) Ltd, Edinburgh (United Kingdom); Jatekos, B.; Ujhelyi, F.; Erdei, G.; Lörincz, E. [Budapest University of Technology and Economics (BME), Budapest (Hungary); André, L.; Maingault, L.; Reboud, V. [CEA-LETI, Grenoble (France); and others

    2014-01-11

    In this paper we illustrate the core technologies at the basis of the European SPADnet project ( (www.spadnet.eu)), and present the corresponding first results. SPADnet is aimed at a new generation of MRI-compatible, scalable large area image sensors, based on CMOS technology, that are networked to perform gamma-ray detection and coincidence to be used primarily in (Time-of-Flight) Positron Emission Tomography (PET). The project innovates in several areas of PET systems, from optical coupling to single-photon sensor architectures, from intelligent ring networks to reconstruction algorithms. In addition, SPADnet introduced the first computational model enabling study of the full chain from gamma photons to network coincidence detection through scintillation events, optical coupling, etc.

  1. Measurement of uranium mass and enrichment by time correlation coincidence method

    International Nuclear Information System (INIS)

    Background: Nuclear materials especially highly enriched uranium materials attract more and more attentions, and increasing methods and technical means are used to detect its information of mass and enrichment. Purpose: In order to solve the key technique problem of measuring the mass and enrichment of highly enriched uranium materials in the heavy shielded containers, a novel trial method was proposed in the paper: Methods: Time correlation coincidence method was implemented by using 14-MeV neutrons and continuous spectrum neutrons obtained by moderating 14-MeV neutrons to interrogate uranium materials inside of lead container with different mass and enrichment. Results: Within the certain range of low enrichment, the relation of different uranium samples mass of same enrichment was linear, and so was the relation of different uranium samples enrichment of same mass. Conclusion: Time correlation coincidence method might be an effective solution to measure the mass and enrichment of uranium materials in the heavy shielded container in the future. (authors)

  2. A Bayesian coincidence test for noise rejection in a gravitational-wave burst search

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, Kipp C [LIGO Laboratory 18-34, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125 (United States)], E-mail: kcannon@ligo.caltech.edu

    2008-05-21

    In searches for gravitational-wave bursts, a standard technique used to reject noise is to discard burst event candidates that are not seen in coincidence in multiple detectors. A coincidence test in which Bayesian inference is used to measure how noise-like a tuple of events appears is presented here. This technique is shown to yield higher detection efficiencies for a given false alarm rate than do techniques based on per-parameter thresholds when applied to a toy model covering a broad class of event candidate populations. Also presented is the real-world example of a use of the technique for noise rejection in a time-frequency burst search conducted on simulated gravitational-wave detector data. Besides achieving a higher detection efficiency, the technique is significantly less challenging to implement well than is a per-parameter threshold method.

  3. Control of the mass of a plutonium sample by neutron coincidences with correction of induced fissions

    International Nuclear Information System (INIS)

    When the isotopic composition of nuclear materials to control is known, it is possible to determine the amount of plutonium by measuring the rate of spontaneous fissions. The induced fissions alter significantly the measures. Therefore we must evaluate the multiplicative factor. For a not very multiplicative sample, the observed neutron coincidences of multiplicity 0 to n agree with spontaneous emissions given by nuclear tables. This is not true in the opposite case (large amounts). Multiplicities are given by eighteen counting-scales associated with a shift-register coincidence system (SCRD) and compared with theoretical spontaneous emissions of the sample. A calculator leads all equipment and compares theoretical and experimental results about the controlled amount of Pu

  4. Chiral asymmetry in the multiphoton ionization of methyloxirane using femtosecond electron-ion coincidence imaging.

    Science.gov (United States)

    Rafiee Fanood, Mohammad M; Powis, Ivan; Janssen, Maurice H M

    2014-12-11

    Multiphoton photoelectron circular dichroism (MP-PECD) has been observed as an asymmetry in the angular distribution of photoelectrons emitted in the ionization of pure enantiomers of the small chiral molecule methyloxirane using a femtosecond laser operated at 420 nm. Energetically, this requires the uptake of four photons. By switching the laser between left- and right-circular polarization, and observing the differences in the full three-dimensional electron momentum distribution recorded in an electron-ion coincidence technique, the chiral (odd) terms in the angular distribution expression can be isolated. Electron events can additionally be filtered by coincident ion mass, providing mass-tagged electron distributions and quantitative measures of the MP-PECD asymmetry that help characterize the different ionization channels. For the production of ground state parent cation, the magnitude of the mean chiral asymmetry is measured to be 4.7%, with a peak magnitude exceeding 10% PMID:25402546

  5. A feasibility study of a coincidence counting approach for PGNAA applications

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, R.P. E-mail: gardner@ncsu.edu; Mayo, C.W.; El-Sayyed, E.S.; Metwally, W.A.; Zheng, Y.; Poezart, M

    2000-11-15

    Prompt gamma-ray neutron activation analysis (PGNAA) has an inherently low signal-to-noise (S/N) ratio primarily because of the large background (noise) associated with it. Most elements emit a significant fraction of their prompt gamma rays in coincidence with one or more other prompt gamma rays. This paper reports on initial efforts to use coincidence counting in PGNAA to significantly reduce the several sources of background and thereby increase the S/N ratio. An added benefit is the elimination of the often dominant hydrogen prompt gamma-ray spectrum which emits only a single prompt gamma ray with an energy of 2.223 MeV. Preliminary results are given for both in situ bulk analysis applications with a {sup 252}Cf neutron source and for nuclear reactor thermal neutron beam applications for small laboratory samples.

  6. A feasibility study of a coincidence counting approach for PGNAA applications

    Science.gov (United States)

    Gardner; Mayo; El-Sayyed; Metwally; Zheng; Poezart

    2000-10-01

    Prompt gamma-ray nutron activation analysis (PGNAA) has an inherently low signal-to-noise (S/N) ratio primarily because of the large background (noise) associated with it. Most elements emit a significant fraction of their prompt gamma rays in coincidence with one or more other prompt gamma rays. This paper reports on initial efforts to use coincidence counting in PGNAA to significantly reduce the several sources of background and thereby increase the S/N ratio. An added benefit is the elimination of the often dominant hydrogen prompt gamma-ray spectrum which emits only a single prompt gamma ray with an energy of 2.223 MeV. Preliminary results are given for both in situ bulk analysis applications with a 252Cf neutron source and for nuclear reactor thermal neutron beam applications for small laboratory samples. PMID:11003486

  7. A feasibility study of a coincidence counting approach for PGNAA applications

    International Nuclear Information System (INIS)

    Prompt gamma-ray neutron activation analysis (PGNAA) has an inherently low signal-to-noise (S/N) ratio primarily because of the large background (noise) associated with it. Most elements emit a significant fraction of their prompt gamma rays in coincidence with one or more other prompt gamma rays. This paper reports on initial efforts to use coincidence counting in PGNAA to significantly reduce the several sources of background and thereby increase the S/N ratio. An added benefit is the elimination of the often dominant hydrogen prompt gamma-ray spectrum which emits only a single prompt gamma ray with an energy of 2.223 MeV. Preliminary results are given for both in situ bulk analysis applications with a 252Cf neutron source and for nuclear reactor thermal neutron beam applications for small laboratory samples

  8. Development of a coincidence system for the measurement of X-ray emission atomic parameters

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Filiberto; Miranda, Javier [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, 01000 Mexico, D.F (Mexico)

    2013-07-03

    Preliminary results obtained in experiments carried out with an x-ray spectrometer built at the Instituto de Fisica for Atomic Physics and environmental sciences studies are presented. The experiments are based on a coincidence method for signals produced by LEGe and Si(Li) detectors. The x-ray fluorescence yields ({omega}{sub Li}) and Coster-Kronig transition probabilities (f{sub ij}) for elements with 55 {<=} Z {<=} 60 are among the quantities of interest. The method is based on the simultaneous detection of K x-rays with the LEGe detector and the L x-rays with the Si(Li) detector. The primary radiation source is an x-ray tube with Rh anode. The system was tested with the coincidence of the L x-rays from Ce with its K line, demonstrating the feasibility of the experiments.

  9. Standardization of 56Co had been carried out using 4 pi beta-gamma coincidence methods

    International Nuclear Information System (INIS)

    Standardization of exp.56 Co had been carried out using 4 pi beta-gamma coincidence methods. The radionuclide use for calibration of nuclear instruments on range of energy over 1500 keV. The exp.56 Co had been produced by irradiation of proton by using a cyclotron with 15 MeV of energy and 300 mb of cross-section to natural iron target (99,5% of purity) at the Institute for Nuclear Study, University of Tokyo. Source preparation had been done by gravimetry method after the irradiated source was dissolved in 8N HCI solution. The disintegration rate had been measured using 4 pi beta-gamma coincidence apparatus, where the gamm gets sets on 511 and 847 keV gamma-rays. The result measurement is fairly good with the specific activity is 3078 n 15 Bq/mg

  10. Standardization of 18F by Digital beta(LS)-gamma Coincidence Counting

    CERN Document Server

    D., Rodrigues; P., Cassette; P., Arenillas; E., Capoulat M; G., Ceruti; E, García-Toraño

    2010-01-01

    The nuclide 18F disintegrates to 18O by beta+ emission (96.86%) and electron capture (3.14%) with a half-life of 1.8288 h. It is widely used in nuclear medicine for positron emission tomography (PET). Because of its short half-life this nuclide requires the development of fast measuring methods to be standardized. The combination of LSC methods with digital techniques proves to be a good alternative to get low uncertainties for this, and other, short lived nuclides. A radioactive solution of 18F has been standardized by coincidence counting with a LSC, using the logical sum of double coincidences in a TDCR array and a NaI scintillation detector. The results show good consistency with other techniques like 4Pi gamma and LSC.

  11. LINEAR BUNDLES WITHIN THE FRAMEWORK OF COINCIDENCE OF CIRCLE AND ELLIPSE

    Directory of Open Access Journals (Sweden)

    Polezhaev Yuriy Olegovich

    2012-10-01

    Full Text Available Compositions represented by geometrical graphic models of circular and elliptical shapes enjoy wide application in architectural and interior design. The research of variations of coincidences of circles and ellipses is a relevant subject of exploration. In the paper, the authors analyze some of the multiplicity of coincidences, and an example of their practical implementation (a church dome model. The section of an object is "amalgamated" into the architectural concept of the structure, the relief and theological ideas. Geometric interlinks, compositions and figurations of interconnected diameters, circular and elliptical arcs, their tangency, incidences and interspaces have always been of interest to researchers; they have triggered the search for harmonious and rational solutions in civil engineering and architecture. Advancements in theoretical geometrography and its software applications facilitate new solutions.

  12. Coincident site lattice-matched growth of semiconductors on substrates using compliant buffer layers

    Energy Technology Data Exchange (ETDEWEB)

    Norman, Andrew

    2016-08-23

    A method of producing semiconductor materials and devices that incorporate the semiconductor materials are provided. In particular, a method is provided of producing a semiconductor material, such as a III-V semiconductor, on a silicon substrate using a compliant buffer layer, and devices such as photovoltaic cells that incorporate the semiconductor materials. The compliant buffer material and semiconductor materials may be deposited using coincident site lattice-matching epitaxy, resulting in a close degree of lattice matching between the substrate material and deposited material for a wide variety of material compositions. The coincident site lattice matching epitaxial process, as well as the use of a ductile buffer material, reduce the internal stresses and associated crystal defects within the deposited semiconductor materials fabricated using the disclosed method. As a result, the semiconductor devices provided herein possess enhanced performance characteristics due to a relatively low density of crystal defects.

  13. Application of Triple Coincidence for the Detection of Small Amounts of Special Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    DIOSZEGI, I.; Salwen, C.; and Forman, L.

    2011-06-12

    We constructed a device that measures two {gamma}-rays and one neutron from spontaneous fission and any resulting multiplication chains. It extends the associated particle technique based upon correlated counting of the multiplicity of gamma-rays and neutrons released in spontaneous- or neutron-induced fission. There are two advantages in incorporating a third detector in the design over the standard two-detector version. First, we found that random uncorrelated events dominate the background of coincident counting with a gamma-ray- and neutron-detector. These might be suppressed by requiring an additional coincidence. Second, the time history of gamma-ray emission between the two gamma-ray detectors is related to multiplication in the target media. Multiplication in highly enriched uranium is much greater than in depleted uranium.

  14. Non-coincident inter-instrument comparisons of ozone measurements using quasi-conservative coordinates

    Directory of Open Access Journals (Sweden)

    L. R. Lait

    2004-01-01

    Full Text Available Ozone measurements from ozonesondes, AROTAL, DIAL, and POAM III instruments during the SOLVE-2/VINTERSOL period are composited in a time-varying, flow-following quasi-conservative (PV-θ coordinate space; the resulting composites from each instrument are mapped onto the other instruments' locations and times. The mapped data are then used to intercompare data from the different instruments. Overall, the four ozone data sets are found to be in good agreement. AROTAL shows somewhat lower values below 16 km, and DIAL has a positive bias at the upper limits of its altitude range. These intercomparisons are consistent with those obtained from more conventional near-coincident profiles, where available. Although the PV-θ mapping technique entails larger uncertainties of individual profile differences compared to direct near-coincident comparisons, the ability to include much larger numbers of comparisons can make this technique advantageous.

  15. Non-coincident inter-instrument comparisons of ozone measurements using quasi-conservative coordinates

    Directory of Open Access Journals (Sweden)

    L. R. Lait

    2004-08-01

    Full Text Available Ozone measurements from ozonesondes, AROTAL, DIAL, and POAM III instruments during the SOLVE-2/VINTERSOL period are composited in a time-varying, flow-following quasi-conservative (PV-θ coordinate space; the resulting composites from each instrument are mapped onto the other instruments' locations and times. The mapped data are then used to intercompare data from the different instruments. Overall, the four ozone data sets are found to be in good agreement. AROTAL shows somewhat lower values below 16 km, and DIAL has a positive bias at the upper limits of its altitude range. These intercomparisons are consistent with those obtained from more conventional near-coincident profiles, where available. Although the PV-θ mapping technique entails larger uncertainties of individual profile differences compared to direct near-coincident comparisons, the ability to include much larger numbers of comparisons can make this technique advantageous.

  16. Coincidence spectroscopy of high-lying Rydberg states produced in strong laser fields

    Science.gov (United States)

    Larimian, Seyedreza; Erattupuzha, Sonia; Lemell, Christoph; Yoshida, Shuhei; Nagele, Stefan; Maurer, Raffael; Baltuška, Andrius; Burgdörfer, Joachim; Kitzler, Markus; Xie, Xinhua

    2016-09-01

    We demonstrate the detection of high-lying Rydberg states produced in strong laser fields with coincidence spectroscopy. Electron emission after the interaction of strong laser pulses with atoms and molecules is measured together with the parent ions in coincidence measurements. These electrons originate from high-lying Rydberg states with quantum numbers from n ˜20 up to n ≲120 formed by frustrated field ionization. Ionization rates are retrieved from the measured ionization signal of these Rydberg states. Simulations show that both tunneling ionization by a weak dc field and photoionization by blackbody radiation contribute to delayed electron emission on the nano- to microsecond scale. Furthermore, the dependence of the Rydberg-state production on the ellipticity of the driving laser field indicates that such high-lying Rydberg states are populated through electron recapture. The present experiment provides detailed quantitative information on Rydberg production in strong-field interaction.

  17. Coincidence system for the absolute measurement of radionuclides activity using a liquid scintillator

    International Nuclear Information System (INIS)

    A system for the standartization of radioisotopes activity using liquid scintillator detector was developed. The system was set up at Nuclear Metrology Laboratory - L.M.N. (Nuclear Physics Division - IEA). The system performance was checked by absolute activity measurements for two radioisotopes, 60Co and 241Am. The activities were determined by the 4π(α, β-γ) coincidence method. An accuracy of the order of 99,8% was obtained. The results for 60Co were compared with those obtained by 4πβ-γ coincidence method using a proportional counter at L.M.N., while the results for 241Am were compared with those obtained through the linear extrapolation method using the same liquid scintillator. Compared to other systems, the advantages of this one are the simplicity and the short time spent in the sample preparation, and the negligible self-absorption. (Author)

  18. Disentangling Multichannel Photodissociation Dynamics in Acetone by Time-Resolved Photoelectron-Photoion Coincidence Spectroscopy.

    Science.gov (United States)

    Maierhofer, Paul; Bainschab, Markus; Thaler, Bernhard; Heim, Pascal; Ernst, Wolfgang E; Koch, Markus

    2016-08-18

    For the investigation of photoinduced dynamics in molecules with time-resolved pump-probe photoionization spectroscopy, it is essential to obtain unequivocal information about the fragmentation behavior induced by the laser pulses. We present time-resolved photoelectron-photoion coincidence (PEPICO) experiments to investigate the excited-state dynamics of isolated acetone molecules triggered by two-photon (269 nm) excitation. In the complex situation of different relaxation pathways, we unambiguously identify three distinct pump-probe ionization channels. The high selectivity of PEPICO detection allows us to observe the fragmentation behavior and to follow the time evolution of each channel separately. For channels leading to fragment ions, we quantitatively obtain the fragment-to-parent branching ratio and are able to determine experimentally whether dissociation occurs in the neutral molecule or in the parent ion. These results highlight the importance of coincidence detection for the interpretation of time-resolved photochemical relaxation and dissociation studies if multiple pathways are present.

  19. Low-level gamma spectrometry using beta coincidence and Compton suppression.

    Science.gov (United States)

    Grigorescu, E L; De Felice, P; Razdolescu, Anamaria-Cristina; Luca, A

    2004-01-01

    A low-level gamma-ray spectrometry system was developed using a Ge(Li) detector with 6% relative efficiency coupled to a 2pi beta plastic detector for coincidence selection and a massive NaI(Tl) detector for Compton suppression. The integral background count rate for (50-1500)keV was 0.5 s(-1)kg(-1) (Ge), using only beta coincidences. With Compton suppression, a value of 0.25 s(-1)kg(-1) (Ge) was obtained. Spectra with and without Compton suppression were studied for 60Co, 137Cs and 152Eu point sources. Considerations are made concerning the Compton suppression advantages in different situations. PMID:15177343

  20. Interaction between Dark Matter and Dark Energy and the Cosmological Coincidence Problem

    OpenAIRE

    Kourosh Nozari; Noushin Behrouz; Narges Rashidi

    2014-01-01

    We consider a quintessence model of dark energy inspired by scalar-tensor theories of gravity where the scalar field is nonminimally coupled to gravity and dark matter. By considering exponential potential as self-interaction potential, the stability and existence of the critical points are discussed in details. With nonminimally coupled dark sector with gravity, we obtain scaling solutions to address the coincidence problem by considering complex velocity for dark matter. The statefinder dia...

  1. 'TrueCoinc' software utility for calculation of the true coincidence correction

    International Nuclear Information System (INIS)

    The true coincidence correction plays an important role in the overall accuracy of the γ ray spectrometry especially in the case of present-day high volume detectors. The calculation of true coincidence corrections needs detailed nuclear structure information. Recently these data are available in computerized form from the Nuclear Data Centers through the Internet or on a CD-ROM of the Table of Isotopes. The aim has been to develop software for this calculation, using available databases for the levels data. The user has to supply only the parameters of the detector to be used. The new computer program runs under the Windows 95/98 operating system. In the framework of the project a new formula was prepared for calculating the summing out correction and calculation of the intensity of alias lines (sum peaks). The file converter for reading the ENDSF-2 type files was completed. Reading and converting the original ENDSF was added to the program. A computer accessible database of the X rays energies and intensities was created. The X ray emissions were taken in account in the 'summing out' calculation. Calculation of the true coincidence 'summing in' correction was done. The output was arranged to show independently two types of corrections and to calculate the final correction as multiplication of the two. A minimal intensity threshold can be set to show the final list only for the strongest lines. The calculation takes into account all the transitions, independently of the threshold. The program calculates the intensity of X rays (K, L lines). The true coincidence corrections for X rays were calculated. The intensities of the alias γ lines were calculated. (author)

  2. The efficiency variation method for 4pibeta-gamma coincidence counting by ink-jet printing.

    Science.gov (United States)

    Sato, Y; Yamada, T; Hata, T; Moriyama, K; Yunoki, A; Hino, Y

    2008-01-01

    In order to vary the counting efficiencies in the 4pibeta-gamma coincidence extrapolation technique, a radioactive source was coated directly with varying amounts of an electrical conducting pigment using an ink-jet printer. This method can be used to efficiently prepare the multiple sources needed to generate efficiency extrapolation curves, and was successfully applied to the standardization of a (54)Mn source.

  3. A method to estimate the significance of coincident gravitational-wave observations from compact binary coalescence

    OpenAIRE

    Cannon, K; Hanna, C.; Keppel, D.

    2013-01-01

    Coalescing compact binary systems consisting of neutron stars and/or black holes should be detectable with upcoming advanced gravitational-wave detectors such as LIGO, Virgo, GEO and {KAGRA}. Gravitational-wave experiments to date have been riddled with non-Gaussian, non-stationary noise that makes it challenging to ascertain the significance of an event. A popular method to estimate significance is to time shift the events collected between detectors in order to establish a false coincidence...

  4. Gut microflora of abalone Haliotis discus hannai in culture changes coincident with a change in diet

    OpenAIRE

    Tanaka, Reiji; Sugimura, Itsuro; SAWABE, Tomoo; Yoshimizu, Mamoru; Ezura, Yoshio

    2003-01-01

    Development of gut microflora in abalone Haliotis discus hannai cultured at two abalone farms in Japan was similar: (i) gut microflora of juvenile abalones fed on microalgae matched microflora cultured from seawater; and (ii) gut microflora changed coincident with the abalone switching food sources from microalgae to algal pellets. After abalone reached 4 months of age, the gut microflora was replaced by algal polysaccharide-degrading bacteria, which were almost entirely characterized as facu...

  5. Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park

    OpenAIRE

    Dorcas, Michael E.; Willson, John D.; Reed, Robert N.; Snow, Ray W.; Rochford, Michael R.; Miller, Melissa A.; Meshaka, Walter E.; Andreadis, Paul T.; Mazzotti, Frank J.; Christina M. Romagosa; Hart, Kristen M.

    2012-01-01

    Invasive species represent a significant threat to global biodiversity and a substantial economic burden. Burmese pythons, giant constricting snakes native to Asia, now are found throughout much of southern Florida, including all of Everglades National Park (ENP). Pythons have increased dramatically in both abundance and geographic range since 2000 and consume a wide variety of mammals and birds. Here we report severe apparent declines in mammal populations that coincide temporally and spatia...

  6. Two-photon coincident-frequency-entanglement via extended phase matching

    OpenAIRE

    Kuzucu, Onur; Fiorentino, Marco; Albota, Marius A.; Wong, Franco N. C.; Kaertner, Franz X.

    2004-01-01

    We demonstrate a new class of frequency-entangled states generated via spontaneous parametric down-conversion under extended phase matching conditions. Biphoton entanglement with coincident signal and idler frequencies is observed over a broad bandwidth in periodically poled KTiOPO$_4$. We demonstrate high visibility in Hong-Ou-Mandel interferometric measurements under pulsed pumping without spectral filtering, which indicates excellent frequency indistinguishability between the down-converte...

  7. Peak Doubling in SPDC Coincidence Spectra with a Short-Pulse Pump

    OpenAIRE

    Fedorov, Mikhail V.; Mikhailova, Julia M.; Volkov, Peter A.

    2011-01-01

    We describe a double-peak structure of the coincidence spectrum of biphoton states in the process of spontaneous parametric down-conversion with a pump having the form of short pulses. The effect is shown to arise owing to the obligatory symmetry of bihoton wave functions, as wave functions describing states of two bozons obeying the Bose-Einstein statistics. Parameters of the peaks are found and conditions necessary for experimental observation of the effect are determined.

  8. Assay of plutonium oxide in different unknown MOX samples by neutron well coincidence counting

    International Nuclear Information System (INIS)

    During fabrication process of Plutonium based Mixed Oxide (MOX) fuel a few number of equipment/machines are involved to entail the desirable quality product as MOX pellets. It is inherently observed that an ample quantity UO2, PuO2 MOX powder remains deposited or entrapped in high load press used for making pellets. Since plutonium is an important fissile component in MOX, it is to be reutilized for fabrication of pellets. These MOX are collected during refurbishing or maintenance of the equipments from the floor of glove boxes. The estimation of PuO2 in these floor scraps are initiated using Neutron Well Coincidence Counting (NWCC). NWCC is a Non-Destructive technique for determination of amount of PuO2 in MOX sample. The technique monitors neutrons emitting from spontaneous fission of 238Pu, 240Pu and 242Pu are counted by proportional counter filled with 3He gas. To separate fission neutron emitted by even-even Isotope of Pu from background (α,n) neutrons, coincidence logic has been used in this technique. To correlate amount of PuO2 with coincidence count rate, the specific activity of 238Pu, 240Pu, 242Pu and their weight percent are prerequisite. NWCC was used for the determination of PuO2 in MOX floor scrap. The NWCC system was calibrated with series of known Pure PuO2 working standards. Each standard was counted for 100 sec. for five times and the average values were recorded. A calibration was drawn between average coincidence counts and wt of the standard PuO2 samples. This calibration plot was used to determine amount of PuO2 in MOX floor scrap. Precision and accuracy of the system was found to be 3.0 percent for 3.0 g PuO2

  9. Systematic measurements of doppler-coincidence spectra for positron annihilation in pure metals and semiconductors

    International Nuclear Information System (INIS)

    Doppler-broadening measurements of the electron-positron annihilation line in twenty six elements are presented. The adopted coincidence technique allows to reduce the background and point out the contribution of positron annihilation with core electrons. The changes of high momentum contribution is presented for selected examples and a semiempirical analysis of the dependence on electronic structure is performed. Measured data are in good agreement with recent theoretical calculations and can be used to identification of impurities surrounding open volume defects. (author)

  10. SYSTEM OF COINCIDENCE THEOREMS IN PRODUCT TOPOLOGICAL SPACES AND APPLICATIONS (Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    DING Xie-ping

    2005-01-01

    A new notion of finite continuous topological space (in short, FC-space)with out convexity structure was introduced. A new continuous selection theorem was established in FC-spaces. By applying the continuous selection theorem, some new coincidence theorems for two families of set-valued mappings defined on product space of noncompact FC-spaces are proved under much weak assumptions. These results generalize many known results in recent literature. Some applications will be given in a follow-up paper.

  11. New approach to calculate the true-coincidence effect of HpGe detector

    Energy Technology Data Exchange (ETDEWEB)

    Alnour, I. A., E-mail: aaibrahim3@live.utm.my, E-mail: ibrahim.elnour@yahoo.com [Department of Physics, Faculty of Pure and Applied Science, International University of Africa, 12223 Khartoum (Sudan); Wagiran, H. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Skudai,Johor (Malaysia); Ibrahim, N. [Faculty of Defence Science and Technology, National Defence University of Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur (Malaysia); Hamzah, S.; Elias, M. S. [Malaysia Nuclear Agency (MNA), Bangi, 43000 Kajang, Selangor D.E. (Malaysia); Siong, W. B. [Chemistry Department, Faculty of Resource Science & Technology, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak (Malaysia)

    2016-01-22

    The corrections for true-coincidence effects in HpGe detector are important, especially at low source-to-detector distances. This work established an approach to calculate the true-coincidence effects experimentally for HpGe detectors of type Canberra GC3018 and Ortec GEM25-76-XLB-C, which are in operation at neutron activation analysis lab in Malaysian Nuclear Agency (NM). The correction for true-coincidence effects was performed close to detector at distances 2 and 5 cm using {sup 57}Co, {sup 60}Co, {sup 133}Ba and {sup 137}Cs as standard point sources. The correction factors were ranged between 0.93-1.10 at 2 cm and 0.97-1.00 at 5 cm for Canberra HpGe detector; whereas for Ortec HpGe detector ranged between 0.92-1.13 and 0.95-100 at 2 and 5 cm respectively. The change in efficiency calibration curve of the detector at 2 and 5 cm after correction was found to be less than 1%. Moreover, the polynomial parameters functions were simulated through a computer program, MATLAB in order to find an accurate fit to the experimental data points.

  12. A model of spike-timing dependent plasticity: one or two coincidence detectors?

    Science.gov (United States)

    Karmarkar, Uma R; Buonomano, Dean V

    2002-07-01

    In spike-timing dependent plasticity (STDP), synapses exhibit LTD or LTP depending on the order of activity in the presynaptic and postsynaptic cells. LTP occurs when a single presynaptic spike precedes a postsynaptic one (a positive interspike interval, or ISI), while the reverse order of activity (a negative ISI) produces LTD. A fundamental question is whether the "standard model" of plasticity in which moderate increases in Ca(2+) influx through the N-methyl-D-aspartate (NMDA) channels induce LTD and large increases induce LTP, can account for the order and interval sensitivity of STDP. To examine this issue we developed a model that captures postsynaptic Ca(2+) influx dynamics and the associativity of the NMDA receptors. While this model can generate both LTD and LTP, it predicts that LTD will be observed at both negative and positive ISIs. This is because longer and longer positive ISIs induce monotonically decreasing levels of Ca(2+), which eventually fall into the same range that produced LTD at negative ISIs. A second model that incorporated a second coincidence detector in addition to the NMDA receptor generated LTP at positive intervals and LTD only at negative ones. Our findings suggest that a single coincidence detector model based on the standard model of plasticity cannot account for order-specific STDP, and we predict that STDP requires two coincidence detectors. PMID:12091572

  13. Development of a TES-Based Anti-Coincidence Detector for Future X-Ray Observations

    Science.gov (United States)

    Bailey, Catherine N.; Adams, J. S.; Bandler, S. R.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Sadleir, J. E.; Smith, S. J.; Sultana, M.

    2012-01-01

    Microcalorimeters onboard future x-ray observatories require an anticoincidence detector to remove environmental backgrounds. In order to most effectively integrate this anti-coincidence detector with the main microcalorimeter array, both instruments should use similar read-out technology. The detectors used in the Cryogenic Dark Matter Search (CDMS) use a phonon measurement technique that is well suited for an anti-coincidence detector with a microcalorimeter array using SQUID readout. This technique works by using a transition-edge sensor (TES) connected to superconducting collection fins to measure the athermal phonon signal produced when an event occurs in the substrate crystal. Energy from the event propagates through the crystal to the superconducting collection fins, creating quasiparticles, which are then trapped as they enter the TES where they produce a signal. We are currently developing a prototype anti-coincidence detector for future x-ray missions and have recently fabricated test devices with Mo/Au TESs and Al collection fins. We present results from the first tests of these devices which indicate a proof of concept that quasiparticle trapping is occurring in these materials.

  14. Modelling Random Coincidences in Positron Emission Tomography by Using Singles and Prompts: A Comparison Study

    Science.gov (United States)

    2016-01-01

    Random coincidences degrade the image in Positron Emission Tomography, PET. To compensate for their degradation effects, the rate of random coincidences should be estimated. Under certain circumstances, current estimation methods fail to provide accurate results. We propose a novel method, “Singles–Prompts” (SP), that includes the information conveyed by prompt coincidences and models the pile–up. The SP method has the same structure than the well-known “Singles Rate” (SR) approach. Hence, SP can straightforwardly replace SR. In this work, the SP method has been extensively assessed and compared to two conventional methods, SR and the delayed window (DW) method, in a preclinical PET scenario using Monte–Carlo simulations. SP offers accurate estimates for the randoms rates, while SR and DW tend to overestimate the rates (∼10%, and 5%, respectively). With pile-up, the SP method is more robust than SR (but less than DW). At the image level, the contrast is overestimated in SR-corrected images, +16%, while SP produces the correct value. Spill–over is slightly reduced using SP instead of SR. The DW images values are similar to those of SP except for low-statistic scenarios, where DW behaves as if randoms were not compensated for. In particular, the contrast is reduced, −16%. In general, the better estimations of SP translate into better image quality. PMID:27603143

  15. Frequencies of mutagen-induced coincident mitotic recombination at unlinked loci in Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Kathryn M. [Department of Biology, College of the Holy Cross, One College Street, Worcester, MA 01610-2395 (United States); Hoffmann, George R. [Department of Biology, College of the Holy Cross, One College Street, Worcester, MA 01610-2395 (United States)]. E-mail: ghoffmann@holycross.edu

    2007-03-01

    Frequencies of coincident genetic events were measured in strain D7 of Saccharomyces cerevisiae. This diploid strain permits the detection of mitotic gene conversion involving the trp5-12 and trp5-27 alleles, mitotic crossing-over and gene conversion leading to the expression of the ade2-40 and ade2-119 alleles as red and pink colonies, and reversion of the ilv1-92 allele. The three genes are on different chromosomes, and one might expect that coincident (simultaneous) genetic alterations at two loci would occur at frequencies predicted by those of the single alterations acting as independent events. Contrary to this expectation, we observed that ade2 recombinants induced by bleomycin, {beta}-propiolactone, and ultraviolet radiation occur more frequently among trp5 convertants than among total colonies. This excess among trp5 recombinants indicates that double recombinants are more common than expected for independent events. No similar enrichment was found among Ilv{sup +} revertants. The possibility of an artifact in which haploid yeasts that mimic mitotic recombinants are generated by a low frequency of cryptic meiosis has been excluded. Several hypotheses that can explain the elevated incidence of coincident mitotic recombination have been evaluated, but the cause remains uncertain. Most evidence suggests that the excess is ascribable to a subset of the population being in a recombination-prone state.

  16. Three-head positron coincidence detection (γ PET) by PRISM-IRIX gamma camera system

    International Nuclear Information System (INIS)

    The Shimadzu PRISM-IRIX is a three-headed variable-angle gamma camera system that also ensures the highest performances in single photon emission computed tomography (SPECT). It provides not only single photon imaging, but also positron coincidence imaging, by using two of the three heads. We have successfully improved the hardware and software of this system, so that the system fully utilizes all of the three heads in order to perform more reliable positron coincidence imaging. Also, we utilized the method of computer simulation to find out the head configuration that ensures the highest performances. Our investigations have shown that the triangular head configuration ensures the highest performances and stability of results in examinations of small organs where the rotation angle is set to 15 cm and that the C-mode head configuration gives the highest stability in examinations of larger organs where the rotation angle is set to 30 cm. We have further improved the electronic circuitry of the head to establish a system called AZTec (adaptive zone technology system). This system ensures even higher coincidence efficiency and higher performances in general. (author)

  17. Detecting gravitational waves from inspiraling binaries with a network of detectors coherent versus coincident strategies

    CERN Document Server

    Mukhopadhyay, H; Kanda, H T N; Sago, N; Tagoshi, H; Dhurandhar, Sanjeev; Kanda, Hirotaka Takahashi & Nobuyuki; Mukhopadhyay, Himan; Sago, Norichica; Tagoshi, Hideyuki

    2006-01-01

    We compare two strategies of multi-detector detection of compact binary inspiral signals, namely, the coincidence and the coherent. For simplicity we consider here two identical detectors having the same power spectral density of noise, that of initial LIGO, located in the same place and having the same orientation. We consider the cases of independent noise as well as that of correlated noise. The coincident strategy involves separately making two candidate event lists, one for each detector, and from these choosing those pairs of events from the two lists which lie within a suitable parameter window, which then are called as coincidence detections. The coherent strategy on the other hand involves combining the data phase coherently, so as to obtain a single network statistic which is then compared with a single threshold. Here we attempt to shed light on the question as to which strategy is better. We compare the performances of the two methods by plotting the Receiver Operating Characteristics (ROC) for th...

  18. Decay of electric charge on corona charged polyethylene

    International Nuclear Information System (INIS)

    This paper describes a study on the surface potential decay of corona charged low density polyethylene (LDPE) films. A conventional corona charging process is used to deposit charge on the surface of film and surface potential is measured by a compact JCI 140 static monitor. The results from corona charged multilayer sample reveal that the bulk process dominates charge decay. In addition, the pulsed-electro-acoustic (PEA) technique has been employed to monitor charge profiles in corona charged LDPE films. By using the PEA technique, we are able to monitor charge migration through the bulk. Charge profiles in corona charged multilayer sample are consistent with surface potential results. Of further significance, the charge profiles clearly demonstrate that double injection has taken place in corona charged LDPE films

  19. Imaging photoelectron circular dichroism of chiral molecules by femtosecond multiphoton coincidence detection

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, C. Stefan; Ram, N. Bhargava; Janssen, Maurice H. M., E-mail: m.h.m.janssen@vu.nl [LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Powis, Ivan [School of Chemistry, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2013-12-21

    Here, we provide a detailed account of novel experiments employing electron-ion coincidence imaging to discriminate chiral molecules. The full three-dimensional angular scattering distribution of electrons is measured after photoexcitation with either left or right circular polarized light. The experiment is performed using a simplified photoelectron-photoion coincidence imaging setup employing only a single particle imaging detector. Results are reported applying this technique to enantiomers of the chiral molecule camphor after three-photon ionization by circularly polarized femtosecond laser pulses at 400 nm and 380 nm. The electron-ion coincidence imaging provides the photoelectron spectrum of mass-selected ions that are observed in the time-of-flight mass spectra. The coincident photoelectron spectra of the parent camphor ion and the various fragment ions are the same, so it can be concluded that fragmentation of camphor happens after ionization. We discuss the forward-backward asymmetry in the photoelectron angular distribution which is expressed in Legendre polynomials with moments up to order six. Furthermore, we present a method, similar to one-photon electron circular dichroism, to quantify the strength of the chiral electron asymmetry in a single parameter. The circular dichroism in the photoelectron angular distribution of camphor is measured to be 8% at 400 nm. The electron circular dichroism using femtosecond multiphoton excitation is of opposite sign and about 60% larger than the electron dichroism observed before in near-threshold one-photon ionization with synchrotron excitation. We interpret our multiphoton ionization as being resonant at the two-photon level with the 3s and 3p Rydberg states of camphor. Theoretical calculations are presented that model the photoelectron angular distribution from a prealigned camphor molecule using density functional theory and continuum multiple scattering X alpha photoelectron scattering calculations

  20. An improved charge pump with suppressed charge sharing effect

    Directory of Open Access Journals (Sweden)

    Na Bai

    2013-09-01

    Full Text Available A differential charge pump with reduced charge sharing effect is presented. The current-steering topology is adopted for fast switching. A replica charge pump is added to provide a current path for the complementary branch of the master charge pump in the current switching. Through the replica charge pump, the voltage at the complementary node of the master charge pump keeps stable during switching, and the dynamic charge sharing effect is avoided. Apply the charge pump to a 4.8 GHz band integer-N PLL, the measured reference spur is -49.7dBc with a 4-MHz reference frequency.

  1. Space-Charge Effect

    CERN Document Server

    Chauvin, N

    2013-01-01

    First, this chapter introduces the expressions for the electric and magnetic space-charge internal fields and forces induced by high-intensity beams. Then, the root-mean-square equation with space charge is derived and discussed. In the third section, the one-dimensional Child-Langmuir law, which gives the maximum current density that can be extracted from an ion source, is exposed. Space-charge compensation can occur in the low-energy beam transport lines (located after the ion source). This phenomenon, which counteracts the spacecharge defocusing effect, is explained and its main parameters are presented. The fifth section presents an overview of the principal methods to perform beam dynamics numerical simulations. An example of a particles-in-cells code, SolMaxP, which takes into account space-charge compensation, is given. Finally, beam dynamics simulation results obtained with this code in the case of the IFMIF injector are presented.

  2. Primitive Virtual Negative Charge

    CERN Document Server

    Kim, Kiyoung

    2008-01-01

    Physical fields, such as gravity and electromagnetic field, are interpreted as results from rearrangement of vacuum particles to get the equilibrium of net charge density and net mass density in 4-dimensional complex space. Then, both fields should interact to each other in that physical interaction is considered as a field-to-field interaction. Hence, Mass-Charge interaction is introduced with primitive-virtual negative charge defined for the mass. With the concept of Mass-Charge interaction electric equilibrium of the earth is discussed, especially about the electric field and magnetic field of the earth. For unsettled phenomena related with the earth's gravity, such as antigravity phenomenon, gravity anomalies during the solar eclipses, the connection between geomagnetic storms and earthquakes, etc., possible explanations are discussed.

  3. Electrically charged targets

    Science.gov (United States)

    Goodman, Ronald K.; Hunt, Angus L.

    1984-01-01

    Electrically chargeable laser targets and method for forming such charged targets in order to improve their guidance along a predetermined desired trajectory. This is accomplished by the incorporation of a small amount of an additive to the target material which will increase the electrical conductivity thereof, and thereby enhance the charge placed upon the target material for guidance thereof by electrostatic or magnetic steering mechanisms, without adversely affecting the target when illuminated by laser energy.

  4. MOSFET Electric-Charge Sensor

    Science.gov (United States)

    Robinson, Paul A., Jr.

    1988-01-01

    Charged-particle probe compact and consumes little power. Proposed modification enables metal oxide/semiconductor field-effect transistor (MOSFET) to act as detector of static electric charges or energetic charged particles. Thickened gate insulation acts as control structure. During measurements metal gate allowed to "float" to potential of charge accumulated in insulation. Stack of modified MOSFET'S constitutes detector of energetic charged particles. Each gate "floats" to potential induced by charged-particle beam penetrating its layer.

  5. Effect of the charge localization in the C+-H+ fragmentation pathway of the ethyne dication

    International Nuclear Information System (INIS)

    The C+-H+ channel in the fragmentation of the ethyne dication following inner-shell ionization has been studied by Auger electron-ion-ion coincidence spectroscopy. The ion-ion coincidence map shows a peculiar feature which corresponds to the emission of both the H+ and C+ ions in the same direction. The analysis of the data, complemented by ab initio calculations, suggests an interpretation in terms of a two-step, asynchronous concerted reaction, in which the charge of the ethynyl intermediate ion localizes on the terminal carbon atom.

  6. Marrow Adipose Tissue Expansion Coincides with Insulin Resistance in MAGP1-Deficient Mice.

    Science.gov (United States)

    Walji, Tezin A; Turecamo, Sarah E; Sanchez, Alejandro Coca; Anthony, Bryan A; Abou-Ezzi, Grazia; Scheller, Erica L; Link, Daniel C; Mecham, Robert P; Craft, Clarissa S

    2016-01-01

    Marrow adipose tissue (MAT) is an endocrine organ with the potential to influence skeletal remodeling and hematopoiesis. Pathologic MAT expansion has been studied in the context of severe metabolic challenge, including caloric restriction, high fat diet feeding, and leptin deficiency. However, the rapid change in peripheral fat and glucose metabolism associated with these models impedes our ability to examine which metabolic parameters precede or coincide with MAT expansion. Microfibril-associated glycoprotein-1 (MAGP1) is a matricellular protein that influences cellular processes by tethering signaling molecules to extracellular matrix structures. MAGP1-deficient (Mfap2 (-/-)) mice display a progressive excess adiposity phenotype, which precedes insulin resistance and occurs without changes in caloric intake or ambulation. Mfap2 (-/-) mice were, therefore, used as a model to associate parameters of metabolic disease, bone remodeling, and hematopoiesis with MAT expansion. Marrow adiposity was normal in Mfap2 (-/-) mice until 6 months of age; however, by 10 months, marrow fat volume had increased fivefold relative to wild-type control at the same age. Increased gonadal fat pad mass and hyperglycemia were detectable in Mfap2 (-/-) mice by 2 months, but peaked by 6 months. The development of insulin resistance coincided with MAT expansion. Longitudinal characterization of bone mass demonstrated a disconnection in MAT volume and bone volume. Specifically, Mfap2 (-/-) mice had reduced trabecular bone volume by 2 months, but this phenotype did not progress with age or MAT expansion. Interestingly, MAT expansion in the 10-month-old Mfap2 (-/-) mice was associated with modest alterations in basal hematopoiesis, including a shift from granulopoiesis to B lymphopoiesis. Together, these findings indicate MAT expansion is coincident with insulin resistance, but not excess peripheral adiposity or hyperglycemia in Mfap2 (-/-) mice; and substantial MAT accumulation does

  7. Utilization of coincidence criteria in absolute length measurements by optical interferometry in vacuum and air

    International Nuclear Information System (INIS)

    Traceability of length measurements to the international system of units (SI) can be realized by using optical interferometry making use of well-known frequencies of monochromatic light sources mentioned in the Mise en Pratique for the realization of the metre. At some national metrology institutes, such as Physikalisch-Technische Bundesanstalt (PTB) in Germany, the absolute length of prismatic bodies (e.g. gauge blocks) is realized by so-called gauge-block interference comparators. At PTB, a number of such imaging phase-stepping interference comparators exist, including specialized vacuum interference comparators, each equipped with three highly stabilized laser light sources. The length of a material measure is expressed as a multiple of each wavelength. The large number of integer interference orders can be extracted by the method of exact fractions in which the coincidence of the lengths resulting from the different wavelengths is utilized as a criterion. The unambiguous extraction of the integer interference orders is an essential prerequisite for correct length measurements. This paper critically discusses coincidence criteria and their validity for three modes of absolute length measurements: 1) measurements under vacuum in which the wavelengths can be identified with the vacuum wavelengths, 2) measurements under air in which the air refractive index is obtained from environmental parameters using an empirical equation, and 3) measurements under air in which the air refractive index is obtained interferometrically by utilizing a vacuum cell placed along the measurement pathway. For case 3), which corresponds to PTB’s Kösters-Comparator for long gauge blocks, the unambiguous determination of integer interference orders related to the air refractive index could be improved by about a factor of ten when an ‘overall dispersion value,’ suggested in this paper, is used as coincidence criterion. (paper)

  8. Pathological α-synuclein distribution in subjects with coincident Alzheimer's and Lewy body pathology.

    Science.gov (United States)

    Toledo, Jon B; Gopal, Pallavi; Raible, Kevin; Irwin, David J; Brettschneider, Johannes; Sedor, Samantha; Waits, Kayla; Boluda, Susana; Grossman, Murray; Van Deerlin, Vivianna M; Lee, Edward B; Arnold, Steven E; Duda, John E; Hurtig, Howard; Lee, Virginia M-Y; Adler, Charles H; Beach, Thomas G; Trojanowski, John Q

    2016-03-01

    We investigated the distribution patterns of Lewy body-related pathology (LRP) and the effect of coincident Alzheimer disease (AD) pathology using a data-driven clustering approach that identified groups with different LRP pathology distributions without any diagnostic or researcher's input in two cohorts including: Parkinson disease patients without (PD, n = 141) and with AD (PD-AD, n = 80), dementia with Lewy bodies subjects without AD (DLB, n = 13) and demented subjects with AD and LRP pathology (Dem-AD-LB, n = 308). The Dem-AD-LB group presented two LRP patterns, olfactory-amygdala and limbic LRP with negligible brainstem pathology, that were absent in the PD groups, which are not currently included in the DLB staging system and lacked extracranial LRP as opposed to the PD group. The Dem-AD-LB individuals showed relative preservation of substantia nigra cells and dopamine active transporter in putamen. PD cases with AD pathology showed increased LRP. The cluster with occipital LRP was associated with non-AD type dementia clinical diagnosis in the Dem-AD-LB group and a faster progression to dementia in the PD groups. We found that (1) LRP pathology in Dem-AD-LB shows a distribution that differs from PD, without significant brainstem or extracranial LRP in initial phases; (2) coincident AD pathology is associated with increased LRP in PD indicating an interaction; (3) LRP and coincident AD pathology independently predict progression to dementia in PD, and (4) evaluation of LRP needs to acknowledge different LRP spreading patterns and evaluate substantia nigra integrity in the neuropathological assessment and consider the implications of neuropathological heterogeneity for clinical and biomarker characterization. PMID:26721587

  9. A simultaneous beta and coincidence-gamma imaging system for plant leaves

    Science.gov (United States)

    Ranjbar, Homayoon; Wen, Jie; Mathews, Aswin J.; Komarov, Sergey; Wang, Qiang; Li, Ke; O’Sullivan, Joseph A.; Tai, Yuan-Chuan

    2016-05-01

    Positron emitting isotopes, such as 11C, 13N, and 18F, can be used to label molecules. The tracers, such as 11CO2, are delivered to plants to study their biological processes, particularly metabolism and photosynthesis, which may contribute to the development of plants that have a higher yield of crops and biomass. Measurements and resulting images from PET scanners are not quantitative in young plant structures or in plant leaves due to poor positron annihilation in thin objects. To address this problem we have designed, assembled, modeled, and tested a nuclear imaging system (simultaneous beta–gamma imager). The imager can simultaneously detect positrons ({β+} ) and coincidence-gamma rays (γ). The imaging system employs two planar detectors; one is a regular gamma detector which has a LYSO crystal array, and the other is a phoswich detector which has an additional BC-404 plastic scintillator for beta detection. A forward model for positrons is proposed along with a joint image reconstruction formulation to utilize the beta and coincidence-gamma measurements for estimating radioactivity distribution in plant leaves. The joint reconstruction algorithm first reconstructs beta and gamma images independently to estimate the thickness component of the beta forward model and afterward jointly estimates the radioactivity distribution in the object. We have validated the physics model and reconstruction framework through a phantom imaging study and imaging a tomato leaf that has absorbed 11CO2. The results demonstrate that the simultaneously acquired beta and coincidence-gamma data, combined with our proposed joint reconstruction algorithm, improved the quantitative accuracy of estimating radioactivity distribution in thin objects such as leaves. We used the structural similarity (SSIM) index for comparing the leaf images from the simultaneous beta–gamma imager with the ground truth image. The jointly reconstructed images yield SSIM indices of 0.69 and 0.63, whereas

  10. Marrow Adipose Tissue Expansion Coincides with Insulin Resistance in MAGP1-Deficient Mice.

    Science.gov (United States)

    Walji, Tezin A; Turecamo, Sarah E; Sanchez, Alejandro Coca; Anthony, Bryan A; Abou-Ezzi, Grazia; Scheller, Erica L; Link, Daniel C; Mecham, Robert P; Craft, Clarissa S

    2016-01-01

    Marrow adipose tissue (MAT) is an endocrine organ with the potential to influence skeletal remodeling and hematopoiesis. Pathologic MAT expansion has been studied in the context of severe metabolic challenge, including caloric restriction, high fat diet feeding, and leptin deficiency. However, the rapid change in peripheral fat and glucose metabolism associated with these models impedes our ability to examine which metabolic parameters precede or coincide with MAT expansion. Microfibril-associated glycoprotein-1 (MAGP1) is a matricellular protein that influences cellular processes by tethering signaling molecules to extracellular matrix structures. MAGP1-deficient (Mfap2 (-/-)) mice display a progressive excess adiposity phenotype, which precedes insulin resistance and occurs without changes in caloric intake or ambulation. Mfap2 (-/-) mice were, therefore, used as a model to associate parameters of metabolic disease, bone remodeling, and hematopoiesis with MAT expansion. Marrow adiposity was normal in Mfap2 (-/-) mice until 6 months of age; however, by 10 months, marrow fat volume had increased fivefold relative to wild-type control at the same age. Increased gonadal fat pad mass and hyperglycemia were detectable in Mfap2 (-/-) mice by 2 months, but peaked by 6 months. The development of insulin resistance coincided with MAT expansion. Longitudinal characterization of bone mass demonstrated a disconnection in MAT volume and bone volume. Specifically, Mfap2 (-/-) mice had reduced trabecular bone volume by 2 months, but this phenotype did not progress with age or MAT expansion. Interestingly, MAT expansion in the 10-month-old Mfap2 (-/-) mice was associated with modest alterations in basal hematopoiesis, including a shift from granulopoiesis to B lymphopoiesis. Together, these findings indicate MAT expansion is coincident with insulin resistance, but not excess peripheral adiposity or hyperglycemia in Mfap2 (-/-) mice; and substantial MAT accumulation does

  11. Coincidence detection of convergent perforant path and mossy fibre inputs by CA3 interneurons.

    Science.gov (United States)

    Calixto, Eduardo; Galván, Emilio J; Card, J Patrick; Barrionuevo, Germán

    2008-06-01

    We performed whole-cell recordings from CA3 s. radiatum (R) and s. lacunosum-moleculare (L-M) interneurons in hippocampal slices to examine the temporal aspects of summation of converging perforant path (PP) and mossy fibre (MF) inputs. PP EPSPs were evoked from the s. lacunosum-moleculare in area CA1. MF EPSPs were evoked from the medial extent of the suprapyramidal blade of the dentate gyrus. Summation was strongly supralinear when examining PP EPSP with MF EPSP in a heterosynaptic pair at the 10 ms ISI, and linear to sublinear at longer ISIs. This pattern of nonlinearities suggests that R and L-M interneurons act as coincidence detectors for input from PP and MF. Summation at all ISIs was linear in voltage clamp mode demonstrating that nonlinearities were generated by postsynaptic voltage-dependent conductances. Supralinearity was not detected when the first EPSP in the pair was replaced by a simulated EPSP injected into the soma, suggesting that the conductances underlying the EPSP boosting were located in distal dendrites. Supralinearity was selectively eliminated with either Ni2+ (30 microm), mibefradil (10 microm) or nimodipine (15 microm), but was unaffected by QX-314. This pharmacological profile indicates that supralinearity is due to recruitment of dendritic T-type Ca2+channels by the first subthreshold EPSP in the pair. Results with the hyperpolarization-activated (Ih) channel blocker ZD 7288 (50 microm) revealed that Ih restricted the time course of supralinearity for coincidently summed EPSPs, and promoted linear to sublinear summation for asynchronous EPSPs. We conclude that coincidence detection results from the counterbalanced activation of T-type Ca2+ channels and inactivation of Ih. PMID:18388134

  12. Disintegration rate of Tc -99m and In -111 radioactive solutions in coincidence systems

    International Nuclear Information System (INIS)

    The 111In and 99mTc standardization in a 4πβ-γ coincidence system is described. The 111In was produced by the reaction of 111Cd (p, n) 111In in the cyclotron. The 111In decays with a half life of 2.8 days by electron capture process, populating the excited levels of 111Cd, emitting two main gamma rays with energies of 171 keV and 245 keV. The 99mTc decay with a half life of 6.007 h for isomeric transition, from the radioactive decay of 99Mo. 111In standardization was carried out in a 4πβ-γ system, consisted of a gas flow proportional counter with 4π geometry coupled to a pair of NaI(Tl) scintillation counter with conventional electronics. The gamma window was set comprising the (171 keV + 245 keV) total absorption energy peaks. The choice of the window was based on the analysis of the extrapolation curves prediction, obtained by Monte Carlo simulation. The 99mTc standardization has been accomplished by the 4πβ-γ coincidence method using a thin window proportional counter in a 4π geometry coupled to a single NaI(Tl) scintillation counter. The beta efficiency was varied by electronic discrimination using a software coincidence counting system (SCS). Two windows were selected for the gamma channel: one at 140 keV gamma ray and the other at 20 keV X ray total absorption peaks. The result of the experimental activity of 111In two solutions agree with the results obtained by Monte Carlo simulation. The experimental activities of 99mTc for the two gamma windows are in agreement within the experimental uncertainty, indicating that the adopted methodology is adequate. (author)

  13. A note on the local cosmological constant and the dark energy coincidence problem

    International Nuclear Information System (INIS)

    It has been suggested that the dark energy coincidence problem could be interpreted as a possible link between the cosmological constant and a massive graviton. We show that by using this link and models for the graviton mass, a dark energy density can be obtained that is indeed very close to measurements by WMAP. As a consequence of the models, the cosmological constant was found to depend on the density of matter. A brief outline of the cosmological consequences such as the effect on the black hole solution is given. (comments, replies and notes)

  14. Dynamic spike threshold and nonlinear dendritic computation for coincidence detection in neuromorphic circuits.

    Science.gov (United States)

    Hsu, Chih-Chieh; Parker, Alice C

    2014-01-01

    We present an electronic cortical neuron incorporating dynamic spike threshold and active dendritic properties. The circuit is simulated using a carbon nanotube field-effect transistor SPICE model. We demonstrate that our neuron has lower spike threshold for coincident synaptic inputs; however when the synaptic inputs are not in synchrony, it requires larger depolarization to evoke the neuron to fire. We also demonstrate that a dendritic spike is key to precisely-timed input-output transformation, produces reliable firing and results in more resilience to input jitter within an individual neuron.

  15. Absolute measurements of the alpha-gamma emitters activities by a sum-coincidence method

    International Nuclear Information System (INIS)

    The absolute activity of U-235 contained in a UO2 sample, using a sum-coincidence circuit which selected only the alpha particles which were simultaneous with the well known 184 Kev gamma radiation from Th-231. The alpha particles were detected by ZnS(Ag) scintillator specially designed to show its maximun efficiency for U-235 alpha particles, whereas the gamma radiation was detected by NaI(Tl) scintillation detector. The values obtained for the half-life of U-235 was compared with data from various observers using different experimental techniques. (Author)

  16. Application of neutron well coincidence counting for plutonium determination in mixed oxide fuel fabrication plant

    International Nuclear Information System (INIS)

    Mixed oxide (MOX) fuel is an alternative to conventional enriched uranium oxide fuel in thermal reactors. Indian interest in plutonium recycle in thermal reactors is primarily due to the need to develop alternative indigenous fuel for two boiling water reactors (BWR) at Tarapur, which are designed to use imported light enriched uranium fuel. A few MOX assemblies have been fabricated and loaded into the reactors. Neutron well coincidence counting (NWCC) system has been successfully employed to check the enrichments of PuO2 in MOX blends. NWCC has also been successfully applied in developing dry recycling process of clean rejected oxide (CRO) and dirty rejected oxide (DRO). (author)

  17. Evaluation Of The Coincidence Of Male Pattern Baldness And Pityrosporum Group Of Fungus In Iran

    OpenAIRE

    Javanbakht Arash; Famili Sorour; Amirmajdi Monireh Mokhtari

    2002-01-01

    The aetilogy of male pattern baldness (MPB) is not clearly found yet. The present study has been designed to determine if three is a significant statistical coincidence between MPB and pityrosporm group of fungal infection. This cross-sectional study covers 50 men with the diagnosis of MPB who visited the dermatology clinic of Qaem hospital of Mashhad Medical University as the case group and 43 men with no evidence of MPB as the control group. A questionnaire was filled out for each person of...

  18. An application of the coincidence Doppler spectroscopy for substances of chemical interest: phthalocyanine and acetylacetonate complexes

    CERN Document Server

    Ito, Y

    2000-01-01

    Coincidence Doppler spectroscopy, which is particularly powerful when one is concerned with high momentum components of positron annihilation gamma-rays, has been applied to two different kinds of organo-metallic ligands: metal phthalocyanines and metal acetylacetonates. The energy (momentum) profiles of the annihilation gamma-rays were the same for metal phthalocyanines indicating that positron and/or positronium are not interacting with the metal ions. However, the profiles for the metal acetylacetonates evidently showed a dependence on the kind of metal ions. Discussion is made on the features of positron interaction which are different for phthalocyanines and acetylacetonates.

  19. Optimization of a coincidence system using plastic scintillators in 4pi geometry.

    Science.gov (United States)

    Dias, M S; Piuvezam-Filho, H; Koskinas, M F

    2008-01-01

    Improvements recently developed at the Nuclear Metrology Laboratory of IPEN-CNEN/SP in São Paulo were performed in order to increase the detector efficiency of a 4pibeta-gamma coincidence primary system using plastic scintillators in 4pi geometry. Measurements were undertaken and compared to the original system and Monte Carlo simulations of the extrapolation curves were calculated for this new system and compared to experimental results. For this purpose, the code Penelope was applied for calculating response functions for each detector and the code Esquema, developed at LMN, was used for simulating the decay scheme processes.

  20. Constructing coincident indices of economic activity for the Latin American economy

    Directory of Open Access Journals (Sweden)

    João Victor Issler

    2013-03-01

    Full Text Available This paper has three main contributions. The first is to propose an individual coincident indicator for the following Latin American countries: Argentina, Brazil, Chile, Colombia and Mexico. In order to obtain similar series to those traditionally used in business-cycle research in constructing coincident indices (output, sales, income and employment we were forced to back-cast several individual country series which were not available in a long time-series span. The second contribution is to establish a chronology of recessions for these countries, covering the period from 1980 to 2012 on a monthly basis. Based on this chronology, the countries are compared in several respects. The final contribution is to propose an aggregate coincident indicator for the Latin American economy, which weights individual-country composite indices. Finally, this indicator is compared with the coincident indicator (The Conference Board - TCB of the U.S. economy. We find that the U.S. indicator Granger-causes the Latin American indicator in statistical testsEsse artigo tem 3 contribuições à literatura de ciclos de negócios. A primeira é a de construir indicadores coincidentes de atividade econômica para Argentina, Brasil, Chile, Colômbia e México, usando pesos idênticos para as séries de Emprego, Produção, Renda, e Vendas. Para tal, tivemos que fazer o back-cast de algumas séries chave para poder construir esses indicadores. A segunda é a de estabelecer uma cronologia de recessões para esses países no período 1980-2012 em bases mensais. Com base na última, fazemos comparações em várias dimensões. Finalmente, nossa última contribuição é propor um índice coincidente agregado para a América Latina, que é comparado ao índice agregado dos EUA. Esta comparação indica que o índice coincidente dos EUA Granger-causa o da América Latina, mas a recíproca não é verdadeira

  1. Flow structure from a horizontal cylinder coincident with a free surface in shallow water flow

    OpenAIRE

    Kahraman Ali; Özgören Muammer; Şahin Beşir

    2012-01-01

    Vortex formation from a horizontal cylinder coincident with a free surface of a shallow water flow having a depth of 25.4 [mm] was experimentally investigated using the PIV technique. Instantaneous and time-averaged flow patterns in the wake region of the cylinder were examined for three different cylinder diameter values under the fully developed turbulent boundary layer condition. Reynolds numbers were in the range of 1124£ Re£ 3374 and Froude numbers were in the range of 0.41 £ Fr £ ...

  2. MISR BRF measurements for various surface types: Intercomparison with coincident airborne and ground measurements.

    Science.gov (United States)

    Abdou, W. A.; Helmlinger, M.; Jovanovic, V. M.; Martonchik, J. V.; Diner, D. J.; Gatebe, C. K.; King, M. D.

    2005-05-01

    The BRF retrieved by the multiangle Imaging spectroRadimeter (MISR) are compared with those coincidently measured from aircraft, by the Cloud Absorption Radiometer (CAR) and MISR airborne simulator (AirMISR), and on the ground, by the Portable Apparatus for Rabid Acquisition of Bidirectional Observations of Land and Atmosphere (PARABOLA III). The intercomparisons are made for five types of surfaces: bright desert, salt pans, dark grassland, forests and dismal swamps. The results show that MISR BRF values are within +/- 10% in agreement with the corresponding airborne and ground measurements, independent of the surface type. This study is part of an effort to validate MISR surface products.

  3. Detector Description and Performance for the First Coincidence Observations between LIGO and GEO

    CERN Document Server

    Abbott, B; Adhikari, R; Allen, B; Amin, R; Anderson, S B; Anderson, W G; Araya, M; Armandula, H; Asiri, F; Aufmuth, P; Aulbert, C; Babak, S V; Balasubramanian, R; Ballmer, S; Barish, B C; Barker, D; Barker-Patton, C; Barnes, M; Barr, B; Barton, M A; Bayer, K; Beausoleil, R; Belczynski, K; Bennett, R; Berukoff, S J; Betzwieser, J; Bhawal, B; Billingsley, G; Black, E; Blackburn, K; Bland-Weaver, B; Bochner, B; Bogue, L; Bork, R G; Bose, S; Brady, P R; Brau, J E; Brown, D A; Brozek, S; Bullington, A; Buonanno, A; Burgess, R; Busby, D; Butler, W E; Byer, R L; Cadonati, L; Cagnoli, G; Camp, J B; Cantley, C A; Cardenas, L; Carter, K; Casey, M M; Castiglione, J; Chandler, A; Chapsky, J; Charlton, P; Chatterji, S; Chen, Y; Chickarmane, V; Chin, D; Christensen, N; Churches, D; Colacino, C N; Coldwell, R; Coles, M; Cook, D; Corbitt, T; Coyne, D; Creighton, J D E; Creighton, T D; Crooks, D R M; Csatorday, P; Cusack, B J; Cutler, C; D'Ambrosio, E; Danzmann, K; Davies, R; Daw, E; De Bra, D; Delker, T; DeSalvo, R; Dhurandhar, S V; Ding, H; Drever, R W P; Dupuis, R J; Ebeling, C; Edlund, J; Ehrens, P; Elliffe, E J; Etzel, T; Evans, M; Evans, T; Fallnich, C; Farnham, D; Fejer, M M; Fine, M; Finn, L S; Flanagan, E; Freise, A; Frey, R; Fritschel, P; Frolov, V; Fyffe, M; Ganezer, K S; Giaime, J A; Gillespie, A; Goda, K; González, G; Gossler, S; Grandclément, P; Grant, A; Gray, C; Gretarsson, A M; Grimmett, D; Grote, H; Grünewald, S; Günther, M; Gustafson, E; Gustafson, R; Hamilton, W O; Hammond, M; Hanson, J; Hardham, C; Harry, G; Hartunian, A; Heefner, J; Hefetz, Y; Heinzel, G; Heng, I S; Hennessy, M; Hepler, N; Heptonstall, A; Heurs, M; Hewitson, M; Hindman, N; Hoang, P; Hough, J; Hrynevych, M; Hua, W; Ingley, R; Ito, M; Itoh, Y; Ivanov, A; Jennrich, O; Johnson, W W; Johnston, W; Jones, L; Jungwirth, D; Kalogera, V; Katsavounidis, E; Kawabe, K; Kawamura, S; Kells, W; Kern, J; Khan, A; Killbourn, S; Killow, C J; Kim, C; King, C; King, P; Klimenko, S; Kloevekorn, P; Koranda, S; Kotter, K; Kovalik, Yu; Kozak, D; Krishnan, B; Landry, M; Langdale, J; Lantz, B; Lawrence, R; Lazzarini, A; Lei, M; Leonhardt, V; Leonor, I; Libbrecht, K; Lindquist, P; Liu, S; Logan, J; Lormand, M; Lubinski, M; Lück, H B; Lyons, T T; Machenschalk, B; MacInnis, M; Mageswaran, M; Mailand, K; Majid, W A; Malec, M; Mann, F; Marin, A; Marka, S; Maros, E; Mason, J; Mason, K; Matherny, O; Matone, L; Mavalvala, N; McCarthy, R; McClelland, D E; McHugh, M; McNamara, P; Mendell, G; Meshkov, S; Messenger, C; Mitselmakher, G; Mittleman, R; Miyakawa, O; Miyoki, S; Mohanty, S; Moreno, G; Mossavi, K; Mours, B; Müller, G; Mukherjee, S; Myers, J; Nagano, S; Nash, T; Naundorf, H; Nayak, R; Newton, G; Nocera, F; Nutzman, P; Olson, T; O'Reilly, B; Ottaway, D J; Ottewill, A; Ouimette, D A; Overmier, H; Owen, B J; Papa, M A; Parameswariah, C; Parameshwaraiah, V; Pedraza, M; Penn, S; Pitkin, M; Plissi, M; Pratt, M; Quetschke, V; Raab, F; Radkins, H; Rahkola, R; Rakhmanov, M; Rao, S R; Redding, D; Regehr, M W; Regimbau, T; Reilly, K T; Reithmaier, K; Reitze, D H; Richman, S; Riesen, R; Riles, K; Rizzi, A; Robertson, D I; Robertson, N A; Robison, L; Roddy, S; Rollins, J; Romano, J D; Romie, J; Rong, H; Rose, D; Rotthoff, E; Rowan, S; Rüdiger, A; Russell, P; Ryan, K; Salzman, I; Sanders, G H; Sannibale, V; Sathyaprakash, B; Saulson, P R; Savage, R; Sazonov, A; Schilling, R; Schlaufman, K; Schmidt, V; Schofield, R; Schrempel, M; Schutz, B F; Schwinberg, P; Scott, S M; Searle, A C; Sears, B; Seel, S; Sengupta, A S; Shapiro, C A; Shawhan, P S; Shoemaker, D H; Shu, Q Z; Sibley, A; Siemens, X; Sievers, L; Sigg, D; Sintes, A M; Skeldon, K D; Smith, J R; Smith, M; Smith, M R; Sneddon, P; Spero, R; Stapfer, G; Strain, K A; Strom, D; Stuver, A; Summerscales, T; Sumner, M C; Sutton, P J; Sylvestre, J; Takamori, A; Tanner, D B; Tariq, H; Taylor, I; Taylor, R; Thorne, K S; Tibbits, M; Tilav, S; Tinto, M; Torres, C; Torrie, C; Traeger, S; Traylor, G; Tyler, W; Ugolini, D W; Vallisneri, M; Van Putten, M H P M; Vass, S; Vecchio, A; Vorvick, C; Wallace, L; Walther, H; Ward, H; Ware, B; Watts, K; Webber, D; Weidner, A; Weiland, U; Weinstein, A; Weiss, R; Welling, H; Wen, L; Wen, S; Whelan, J T; Whitcomb, S E; Whiting, B F; Willems, P A; Williams, P R; Williams, R; Willke, B; Wilson, A; Winjum, B J; Winkler, W; Wise, S; Wiseman, A G; Woan, G; Wooley, R; Worden, J; Yakushin, I; Yamamoto, H; Yoshida, S; Zawischa, I; Zhang, L; Zotov, N P; Zucker, M; Zweizig, J

    2004-01-01

    For 17 days in August and September 2002, the LIGO and GEO interferometer gravitational wave detectors were operated in coincidence to produce their first data for scientific analysis. Although the detectors were still far from their design sensitivity levels, the data can be used to place better upper limits on the flux of gravitational waves incident on the earth than previous direct measurements. This paper describes the instruments and the data in some detail, as a companion to analysis papers based on the first data.

  4. Interaction between Dark Matter and Dark Energy and the Cosmological Coincidence Problem

    Directory of Open Access Journals (Sweden)

    Kourosh Nozari

    2014-01-01

    Full Text Available We consider a quintessence model of dark energy inspired by scalar-tensor theories of gravity where the scalar field is nonminimally coupled to gravity and dark matter. By considering exponential potential as self-interaction potential, the stability and existence of the critical points are discussed in details. With nonminimally coupled dark sector with gravity, we obtain scaling solutions to address the coincidence problem by considering complex velocity for dark matter. The statefinder diagnostic shows that the equation of state reaches ΛCDM model in the future.

  5. Analysis of time correlation measurements with the Active Well Coincidence Counter

    International Nuclear Information System (INIS)

    Active well coincidence counters are widely used for nondestructive assay applications in nuclear safeguards and nuclear waste characterization. The method is based on the detection of correlated neutrons from fission by He-3 detectors embedded in a polyethylene moderator. In the assay of uranium, an active measurement must be performed to induce fission in the material, and typically Am/Li neutron sources are used as the active source. Monte Carlo studies of the measurement setup are useful in the design, optimization, and analysis of the entire measurement system. The simulation must take into account many factors, for example the Am/Li neutron spectrum, the multiplicity of neutron emission in induced fission events, and the detection of thermalized neutrons by the He-3 counters. In this study, we address these issues and present a detailed analysis of the measurement system that includes parameters such as the length of fission chains generated in the fissile material by the source neutrons, the time of neutron detection in the He-3 counters, and the generation number of the detected neutrons. The simulations are performed with the MCNP-PoliMi code. The simulation results are compared with measurements performed on uranium oxide standards with an active well coincidence counter that is in use at the Y-12 National Security Complex. The geometry of the MCNP-PoliMi simulation for the active well coincidence counter is shown. In addition to the simulation of traditional multiplicity parameters given by the shift register (singles, doubles and triples), MCNP-PoliMi allows the user to simulate the entire distribution of time correlations between detectors and detector autocorrelations. We show that this approach, also known as time interval analysis and first proposed by Bruggeman and colleagues in 1996, has the potential to lead to a more robust and complete analysis compared to the measurement of multiplicity alone. The results of this study serve as a preliminary

  6. Note: An improved 3D imaging system for electron-electron coincidence measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yun Fei; Lee, Suk Kyoung; Adhikari, Pradip; Herath, Thushani; Lingenfelter, Steven; Winney, Alexander H.; Li, Wen, E-mail: wli@chem.wayne.edu [Department of Chemistry, Wayne State University, Detroit, Michigan 48202 (United States)

    2015-09-15

    We demonstrate an improved imaging system that can achieve highly efficient 3D detection of two electrons in coincidence. The imaging system is based on a fast frame complementary metal-oxide semiconductor camera and a high-speed waveform digitizer. We have shown previously that this detection system is capable of 3D detection of ions and electrons with good temporal and spatial resolution. Here, we show that with a new timing analysis algorithm, this system can achieve an unprecedented dead-time (<0.7 ns) and dead-space (<1 mm) when detecting two electrons. A true zero dead-time detection is also demonstrated.

  7. Measurement of decay time constant of a plastic scintillator by a delayed coincidence method

    International Nuclear Information System (INIS)

    This report presents a novel method of measuring the decay time constant by a simple delayed coincidence circuit using Field Programmable Gate Arrays (FPGA) based electronics. The basic principle of single photon method involves measuring of average real photoelectron pulse of scintillation without distorting the signal by signal shaping effects of PMT. In general terms, this method for determining the timing dependence of the scintillation intensity consists of measuring the distribution of the difference in time obtained between 'Formation' of scintillation light pulse by detecting scintillations in one PMT and the 'Arrival' of individual single photoelectron at the cathode of another PMT

  8. Experimental comparison of the active well coincidence counter with the random driver

    International Nuclear Information System (INIS)

    A direct comparison has been made between the IAEA Active Well Coincidence Counter (AWCC) and the LASL Random Driver at CMB-8. The comparison included an experimental evaluation of precision, counting rate, accuracy, penetrability, stability, and the effect of sample inhomogeneity. Samples used in the evaluation included highly enriched U3O8, U3O8 mixed with graphite, highly enriched uranium metal discs, and depleted uranium metal. These materials are typical of the samples of interest to the IAEA inspectors. It is concluded that the two instruments had very similar performance characteristics with the Random Driver giving better penetrability and the AWCC giving better stability

  9. Hypohidrotic ectodermal dysplasia and immunodeficiency with coincident NEMO and EDA Mutations

    Directory of Open Access Journals (Sweden)

    Michael D. Keller

    2011-11-01

    Full Text Available Ectodermal dysplasias (ED are uncommon genetic disorders resulting in abnormalities in ectodermally-derived structures. Though many ED-associated genes have been described, the NF-κB Essential Modulator (NEMO encoded by the IKBKG gene is unique in that mutations also result in severe humoral and cellular immunologic defects. We describe three unrelated kindreds with defects in both EDA and IKBKG resulting from an X-chromosome crossover. This demonstrates the importance of thorough immunologic consideration of patients with ED even when an EDA etiology is confirmed, and raises the possibility of a specific phenotype arising from coincident mutations in EDA and IKBKB.

  10. Energy loss of charged particles colliding with an oscillator

    Science.gov (United States)

    Makarov, D. N.

    2015-04-01

    Energy loss of fast charged particles colliding with an oscillator is considered in the dipole approximation. In this approximation, the problem is solved exactly and the energy loss of the oscillator from the initial state | m> = |0> is found in the form of the sum of single integrals. It is shown that passing to the limit, the Bethe theory for an atom with small perturbations can be obtained, and in the case of strong fields, the correction to the Bethe theory, analogous to the Bloch correction, can be calculated; in addition, a classical limit coinciding with the Bohr formula is possible.

  11. Fragmentation of CF3Br induced by fluroine is core excitation: Energy resolved auger electron multiple-ion coincidence measurements

    International Nuclear Information System (INIS)

    Fragmentation processes in CF3Br near the F K edge were investigated using synchrotron radiation and Energy Resolved Auger Electron Multiple Ion Coincidence (ERAEMICO). Time-of flight mass spectra were collected in coincidence with either selected F 1s Auger or resonant-Auger electrons which were energy analyzed with a hemispherical detector. In addition, a more inclusive mass spectrum was taken near the F 1s ionization potential in coincidence with low energy electrons. Preliminary spectra the Br2+ ion intensity is negligible and the relative CF+ abundance is higher. These differences confirm the notion that the electronic state prior to bond breakage governs the resulting fragmentation pattern

  12. Development of a method for activity measurements of {sup 232}Th daughters with a multidetector gamma-ray coincidence spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Antovic, N. [Faculty of Natural Sciences and Mathematics, University of Montenegro, Cetinjski put b.b., 81000 Podgorica (Montenegro)], E-mail: antovicn@yahoo.com; Svrkota, N. [Center for Ecotoxicological Research, Put Radomira Ivanovica 2, 81000 Podgorica (Montenegro)

    2009-06-15

    The method for activity measurements of the {sup 232}Th daughters, developed at the six-crystal gamma-ray coincidence spectrometer PRIPYAT-2M and based on coincidence counting of the 583 and 2615 keV photons from cascade transitions which follow {beta}{sup -}-decay of {sup 208}Tl, as well as on counting the 911 keV photons which follow {beta}{sup -}-decay of {sup 228}Ac in the integral and non-coincidence mode of counting, is presented.

  13. A new 4π(LS)-γ coincidence counter at NCBJ RC POLATOM with TDCR detector in the beta channel.

    Science.gov (United States)

    Ziemek, T; Jęczmieniowski, A; Cacko, D; Broda, R; Lech, E

    2016-03-01

    A new 4π(LS)-γ coincidence system (TDCRG) was built at the NCBJ RC POLATOM. The counter consists of a TDCR detector in the beta channel and scintillation detector with NaI(Tl) crystal in the gamma channel. The system is equipped with a digital board with FPGA, which records and analyses coincidences in the TDCR detector and coincidences between the beta and gamma channels. The characteristics of the system and a scheme of the FPGA implementation with behavioral simulation are given. The TDCRG counter was validated by activity measurements on (14)C and (60)Co solutions standardized in RC POLATOM using previously validated methods.

  14. Highly Charged Ion Sources

    International Nuclear Information System (INIS)

    In this work a study is made for the factors affecting the production and extraction of highly charged ion beams. Discussion is made for the production of highly charged ions from: the conventional vacuum are ion sources (Pinning PIG and Duoplasmatron DP) and the recent trends type which are (Electron Beam Ion Sources EBIS, Electron Cyclotron Resonance Ion Sources ECRIS and Laser Ion source LIS). The highly charged ions with charge state +7 , O+8 ,Ne+10 , Ar+18 have been extracted from the ECRIS while fully stripped Xe+54 has been extracted from EBIS. Improving the capabilities of the conventional RF ion source to produce multiply charged ions is achieved through the use of electron injection into the plasma or with the use of RF driven ion source. The later is based on coupling the RF power to the discharge through an internal antenna in vacuum are ion source. The argon ion species extracted from these upgraded RF ion sources could reach Ar+5

  15. Determination of the 242Pu Branching Ratio via Alpha-Gamma Coincidence

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T F

    2012-05-24

    When the burn-up is high, the {sup 242}Pu isotopic content becomes more important. The traditional correlation method will fail. The {sup 242}Pu isotopic content in the sample plays an essential role if the neutron coincidence method is used to quantify the total amount of plutonium. In one of the earlier measurements we had a chance to measure an isotopic pure (> 99.95 %) {sup 242}Pu thick sample and realized that the difference in the branching ratio (BR) value among current nuclear data3) for the two important gamma-rays at 103.5-keV and 158.8-keV. In this study, the thick sample was counted on a 15% ORTEC safeguards type HPGe to further improve BR determination of the 159-keV gamma-ray. Furthermore, we have made a thin {sup 242}Pu sample from the thick sample and performed alpha-gamma coincidence measurements. Our preliminary gamma-ray BR results are 4.37(6) E-4, 2.79(8) E-5, and 2.25(8) E-6 for 44.9-keV, 103.5-keV, and 158.9-keV, respectively.

  16. Algorithms for Identification of Nearly-Coincident Events in Calorimetric Sensors

    CERN Document Server

    Alpert, B; Bennett, D; Faverzani, M; Fowler, J; Giachero, A; Hays-Wehle, J; Maino, M; Nucciotti, A; Puiu, A; Swetz, D; Ullom, J

    2015-01-01

    For experiments with high arrival rates, reliable identification of nearly-coincident events can be crucial. For calorimetric measurements to directly measure the neutrino mass such as HOLMES, unidentified pulse pile-ups are expected to be a leading source of experimental error. Although Wiener filtering can be used to recognize pile-up, it suffers errors due to pulse-shape variation from detector nonlinearity, readout dependence on sub-sample arrival times, and stability issues from the ill-posed deconvolution problem of recovering Dirac delta-functions from smooth data. Due to these factors, we have developed a processing method that exploits singular value decomposition to (1) separate single-pulse records from piled-up records in training data and (2) construct a model of single-pulse records that accounts for varying pulse shape with amplitude, arrival time, and baseline level, suitable for detecting nearly-coincident events. We show that the resulting processing advances can reduce the required performa...

  17. Development of Simultaneous Beta-and-Coincidence-Gamma Imager for Plant Imaging Research

    Energy Technology Data Exchange (ETDEWEB)

    Tai, Yuan-Chuan [Washington Univ., St. Louis, MO (United States). School of Medicine

    2016-09-30

    The goal of this project is to develop a novel imaging system that can simultaneously acquire beta and coincidence gamma images of positron sources in thin objects such as leaves of plants. This hybrid imager can be used to measure carbon assimilation in plants quantitatively and in real-time after C-11 labeled carbon-dioxide is administered. A better understanding of carbon assimilation, particularly under the increasingly elevated atmospheric CO2 level, is extremely critical for plant scientists who study food crop and biofuel production. Phase 1 of this project is focused on the technology development with 3 specific aims: (1) develop a hybrid detector that can detect beta and gamma rays simultaneously; (2) develop an imaging system that can differentiate these two types of radiation and acquire beta and coincidence gamma images in real-time; (3) develop techniques to quantify radiotracer distribution using beta and gamma images. Phase 2 of this project is to apply technologies developed in phase 1 to study plants using positron-emitting radionuclide such as 11C to study carbon assimilation in biofuel plants.

  18. Fragment ion-photon coincidence investigation of carbon tetrafluoride by controlled electron impact

    International Nuclear Information System (INIS)

    Fragment ion-photon coincidence (FIPCO) spectra by 120 eV electron impact on carbon tetrafluoride (CF4) have been observed, in which optical emission in the 200-600 nm region has been detected. Only the CF3+ fragment has been found in the FIPCO spectra, demonstrating that the dissociative double-ionization process producing a pair of CF3+ and F+ is negligible in the correlation with the optical emission. This finding was already known from photon-impact experiments, but such a process was expected to play an important role in the ultraviolet-visible emission by electron impact on CF4. The translational energy distribution of CF3+ has also been estimated on the basis of the high-resolution FIPCO spectra and their Monte Carlo simulation. The magnitude of the mean translational energy of CF3+ has been explained together with earlier results obtained through threshold photoelectron-photoion coincidence experiments by considering the Franck-Condon region in the transition among the neutral ground state of CF4 and its ionic A, C and D states. (author)

  19. Triple coincidence beam spin asymmetry measurements in Deeply Virtual Compton Scattering

    Science.gov (United States)

    Canan, Mustafa

    2011-12-01

    The Generalized Parton Distributions (GPDs) provides hitherto the most complete information about the quark structure of hadron. GPDs are accessible through hard-exclusive reactions, among which Deeply Virtual Compton Scattering (DVCS) is the cleanest reaction. A dedicated DVCS experiment on Hydrogen (E00-110) ran in the Hall A at Jefferson Laboratory in Fall 2004. I present here Beam Spin Asymmetry (BSA) results for the ep → epgamma reaction studied in the E00-110 experiment with fully exclusive triple coincidence H(e, e'gammap ) detection. I present a re-calibration of the electromagnetic calorimeter used to detect the high energy photon. This calibration is necessary to account for the effects of pile-up. The results show a 1-sigma disagreement with the double coincidence H(e, e'gamma )p results, I also presents a feasibility study for measurements of neutron GPDs via the 3He ? (e, e'gamma)ppn reaction on a polarized 3He target with JLab at 12 GeV. These measurements offer the prospect of a determination of all four GPDs.

  20. Allergic Sensitization Underlies Hyperreactive Antigen-Specific CD4+ T Cell Responses in Coincident Filarial Infection.

    Science.gov (United States)

    Gazzinelli-Guimarães, Pedro H; Bonne-Année, Sandra; Fujiwara, Ricardo T; Santiago, Helton C; Nutman, Thomas B

    2016-10-01

    Among the various hypotheses put forward to explain the modulatory influence of helminth infection on allergic effector responses in humans, the IL-10-induced suppression of Th2-associated responses has been the leading candidate. To explore this helminth/allergy interaction more fully, parasite- and allergen-specific CD4(+) T cell responses in 12 subjects with filarial infections, and coincident allergic sensitization (filarial [Fil](+)allergy [A](+)) were compared with the responses to three appropriate control groups (Fil(-)A(-) [n = 13], Fil(-)A(+) [n = 12], Fil(+)A(-) [n = 11]). The most important findings revealed that Fil(+)A(+) had marked (p eosinophils (p eosinophil-derived neurotoxin [p < 0.01, r = 0.7059]). CD4(+) responses to allergen were not different (to a large extent) among the groups. Taken together, our data suggest that allergic sensitization coincident with filarial infection drives parasite Ag-specific T cell hyperresponsiveness, which is characterized largely by an augmented Th2-dominated immune response. PMID:27566825

  1. A new approach to beta-gamma coincidence counting. Advance report on the Samar electronic system

    International Nuclear Information System (INIS)

    In 4π β-γ coincidence measurements, precision on the evaluation of coincidence counting losses is made difficult because of complex overlapping effects between theβ--and γ-side dead times due to pre cursive counted events. In this context the SAMAR electronic system is aimed to give a precise way of automatic counting and reduce the need for calculated corrections. This report describes its configuration and basic features. The SAMAR has been conceived in such a manner that both beta and gamma chains are sharing a common and non extending dead-time which is simultaneously applied to both channels. The shared dead time is made to be the only one inserted throughout the chains. Overlapping effects vanish and the three counting channels have identical transmission ratios. A new dead-time circuit based on fast linear gates as blocking elements has been developed. Application of the two-oscillator Muller's method evidences a fully non-extending character. Automatism is implemented by using a live timer corrective channel controlling the counting scalers. (Author) 21 refs

  2. The coincidence matrix ASIC of the level-1 muon barrel trigger of the ATLAS experiment

    CERN Document Server

    Bocci, V; Salamon, A; Vari, R; Veneziano, Stefano

    2003-01-01

    The ATLAS barrel level-1 muon trigger processes hit information from the resistive plate chamber detector, identifying candidate muon tracks and assigning them to a programmable p/sub T/ range and to a unique bunch crossing number. The trigger system uses up to seven detector layers and seeks hit patterns compatible with muon tracks in the bending and nonbending projection. The basic principle of the algorithm is to demand a coincidence of hits in the different chamber layers within a path. The width of the road is related to the p/sub T / threshold to be applied. The system is split into an on-detector and an off-detector part. The on-detector electronics reduces the information from about 350 k channels to about 400 32-bit data words sent via optical fiber to the so-called sector logic (SL). The off- detector SL electronics collects muon candidates and associates them to detector regions-of-interest of Delta eta * Delta Phi of 0.1*0.1. The core of the on-detector electronics is the coincidence matrix ASIC (...

  3. Beyond contact-based transmission networks: the role of spatial coincidence.

    Science.gov (United States)

    Richardson, Thomas O; Gorochowski, Thomas E

    2015-10-01

    Animal societies rely on interactions between group members to effectively communicate and coordinate their actions. To date, the transmission properties of interaction networks formed by direct physical contacts have been extensively studied for many animal societies and in all cases found to inhibit spreading. Such direct interactions do not, however, represent the only viable pathways. When spreading agents can persist in the environment, indirect transmission via 'same-place, different-time' spatial coincidences becomes possible. Previous studies have neglected these indirect pathways and their role in transmission. Here, we use rock ant colonies, a model social species whose flat nest geometry, coupled with individually tagged workers, allowed us to build temporally and spatially explicit interaction networks in which edges represent either direct physical contacts or indirect spatial coincidences. We show how the addition of indirect pathways allows the network to enhance or inhibit the spreading of different types of agent. This dual-functionality arises from an interplay between the interaction-strength distribution generated by the ants' movement and environmental decay characteristics of the spreading agent. These findings offer a general mechanism for understanding how interaction patterns might be tuned in animal societies to control the simultaneous transmission of harmful and beneficial agents. PMID:26400200

  4. Ionospheric disturbances observed coincident with the 2006 and 2009 North Korean underground nuclear tests

    Science.gov (United States)

    Yang, Yu-Ming; Garrison, James L.; Lee, See-Chen

    2012-01-01

    Acoustic-Gravity Waves (AGWs) in the neutral atmosphere can induce disturbances in the ionosphere that are subsequently observable in trans-ionospheric Global Navigation Satellite System (GNSS) measurements. Disruptive events on the Earth's surface, such as earthquakes, tsunamis and large explosions are one source of these disturbances. In this study, we apply wavelet analysis to enhance a cross-correlation technique for detecting the presence of ionospheric disturbances in dual frequency GNSS time series collected from the GEONET (Japan) during the North Korean Underground Nuclear Tests (UGTs) conducted on 9 October 2006 and 25 May 2009. Through use of the wavelet coherence analysis, we are able to find significant wave trains in the Integrated Electron Content (IEC) data collected from the network. Low frequency disturbances, with periods between 3 and 12 min and horizontal propagation speeds between 75 and 453 m/s were found coincident with both the 2006 and 2009 events. High frequency disturbances, with periods between 2 and 5 min and horizontal speeds between 297 and 1322 m/s were found only after the 2009 event. The disturbances extracted from these signals showed propagation speeds, directions, and times of arrival coincident with the reported geographic location and times of the UGTs.

  5. Determination of the 242Pu Branching Ratio via Alpha-Gamma Coincidence

    International Nuclear Information System (INIS)

    When the burn-up is high, the 242Pu isotopic content becomes more important. The traditional correlation method will fail. The 242Pu isotopic content in the sample plays an essential role if the neutron coincidence method is used to quantify the total amount of plutonium. In one of the earlier measurements we had a chance to measure an isotopic pure (> 99.95 %) 242Pu thick sample and realized that the difference in the branching ratio (BR) value among current nuclear data3) for the two important gamma-rays at 103.5-keV and 158.8-keV. In this study, the thick sample was counted on a 15% ORTEC safeguards type HPGe to further improve BR determination of the 159-keV gamma-ray. Furthermore, we have made a thin 242Pu sample from the thick sample and performed alpha-gamma coincidence measurements. Our preliminary gamma-ray BR results are 4.37(6) E-4, 2.79(8) E-5, and 2.25(8) E-6 for 44.9-keV, 103.5-keV, and 158.9-keV, respectively.

  6. Coincidences in analysis: Sigmund Freud and the strange case of Dr Forsyth and Herr von Vorsicht.

    Science.gov (United States)

    Pierri, Maria

    2010-08-01

    Freud's interest in thought transference opens the possibility for psychoanalytic research on the primary preverbal language and the maternal function, which the emphasis on verbal and paternal communication had hidden in the background of the setting. The author advances a new interpretation of coincidences in analysis and of the psychopathology of everyday life of the setting. Starting from a strange coincidence, new hypotheses are submitted following additional readings of the unpublished manuscript of the 'Forsyth case', recovered by the author, in regard to a significant moment of transformation, both in Freud and in psychoanalysis, at the end of the war. This phase corresponds first to a change of language, from German to English, as well as to the foundation of the International Journal of Psychoanalysis by Ernest Jones. In particular, the roots of the metapsychological turn of the 1920s are explored, together with the opening of private and productive thoughts in the area of 'telepathy' that joined Freud, Ferenczi, and Anna Freud in a true 'dialogue of unconsciouses'. The free association between A Child Is Being Beaten, Beyond the Pleasure Principle, and the clinical experience with 'Herr B.' is outlined in order to understand Freud's heroic self-analysis at the time when he was treating his daughter Anna and grieving the death of his beloved Sophie.

  7. Coincidence of calcified carotid atheromatous plaque, osteoporosis, and periodontal bone loss in dental panoramic radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh, Aruna; Ganguly, Rumpa [Dept. of Diagnosis and Health Promotion, Division of Oral and Maxillofacial Radiology, Tufts University School of Dental Medicine, Boston (United States); Soroushian, Sheila [Dept. of Orthodontics, Howard University College of Dentistry, Washington, DC(United States)

    2013-12-15

    This study was performed to assess the correlation of calcified carotid atheromatous plaque (CCAP), the mandibular cortical index, and periodontal bone loss in panoramic radiographs. One hundred eighty-five panoramic radiographs with CCAP and 234 without this finding were evaluated by 3 observers for the presence of osseous changes related to osteoporosis and periodontal bone loss. Chi-squared and Mann-Whitney U tests were used to compare the two groups for an association of CCAP with the mandibular cortical index and periodontal bone loss, respectively. There was a statistically significant coincidence of CCAP and osseous changes related to osteopenia/osteoporosis, with a p-value <0.001. There was no statistically significant coincidence of CCAP and periodontal bone loss. When comparing the 2 groups, 'With CCAP' and 'Without CCAP', there was a statistically significant association with the mean body mass index (BMI), number of remaining teeth, positive history of diabetes mellitus, and vascular accidents. There was no statistically significant association with gender or a history of smoking. This study identified a possible concurrence of CCAP and mandibular cortical changes secondary to osteopenia/osteoporosis in panoramic radiographs. This could demonstrate the important role of dental professionals in screening for these systemic conditions, leading to timely and appropriate referrals resulting in early interventions and thus improving overall health.

  8. Rejection of randomly coinciding events in ZnMoO$_4$ scintillating bolometers

    CERN Document Server

    Chernyak, D M; Giuliani, A; Mancuso, M; Nones, C; Olivieri, E; Tenconi, M; Tretyak, V I

    2014-01-01

    Random coincidence of events (particularly from two neutrino double beta decay) could be one of the main sources of background in the search for neutrinoless double beta decay with cryogenic bolometers due to their poor time resolution. Pulse-shape discrimination by using front edge analysis, mean-time and $\\chi^2$ methods was applied to discriminate randomly coinciding events in ZnMoO$_4$ cryogenic scintillating bolometers. These events can be effectively rejected at the level of 99% by the analysis of the heat signals with rise-time of about 14 ms and signal-to-noise ratio of 900, and at the level of 92% by the analysis of the light signals with rise-time of about 3 ms and signal-to-noise ratio of 30, under the requirement to detect 95% of single events. These rejection efficiencies are compatible with extremely low background levels in the region of interest of neutrinoless double beta decay of $^{100}$Mo for enriched ZnMoO$_4$ detectors, of the order of $10^{-4}$ counts/(y keV kg). Pulse-shape parameters ...

  9. Determination of the absolute activity by the coincidences 4πβ-γ method

    International Nuclear Information System (INIS)

    The 4π beta-gamma coincidence method for absolute determination of activities is extremely important in the production of high-precision radioactive sources. By means of this method it is possible to obtain absolute measurements of decay to within 0.1%. Thanks to the high efficiency of the 4π counter, most of the corrections required - background, random coincidences, dead time, decay scheme and detector efficiency - are small. The paper describes the experimental set-up showing the pulses in the two branches of the system, together with the conditions under which the 4πbeta flux detector functions. To determine whether the system was functioning satisfactorily, the activity of four cobalt-60 standards (supplied by the International Bureau of Weights and Measures based at Sevres in France) was determined and the differences obtained were less than 0.5% with respect to the certificates accompanying the sources. Alterations to the flux detector are suggested so that higher accuracy may be obtained. (author)

  10. Rejection of randomly coinciding events in ZnMoO{sub 4} scintillating bolometers

    Energy Technology Data Exchange (ETDEWEB)

    Chernyak, D.M. [Institute for Nuclear Research, Kyiv (Ukraine); Centre de Sciences Nucleaires et de Sciences de la Matiere, Orsay (France); Danevich, F.A.; Tretyak, V.I. [Institute for Nuclear Research, Kyiv (Ukraine); Giuliani, A.; Mancuso, M. [Centre de Sciences Nucleaires et de Sciences de la Matiere, Orsay (France); Dipartimento di Scienza e Alta Tecnologia dell' Universita dell' Insubria, Como (Italy); Nones, C. [Service de Physique des Particules, CEA-Saclay, Gif sur Yvette (France); Olivieri, E.; Tenconi, M. [Centre de Sciences Nucleaires et de Sciences de la Matiere, Orsay (France)

    2014-06-15

    Random coincidence of events (particularly from two neutrino double beta decay) could be one of the main sources of background in the search for neutrinoless double beta decay with cryogenic bolometers due to their poor time resolution. Pulse-shape discrimination by using front edge analysis, mean-time and χ{sup 2} methods were applied to discriminate randomly coinciding events in ZnMoO{sub 4} cryogenic scintillating bolometers. These events can be effectively rejected at the level of 99 % by the analysis of the heat signals with rise-time of about 14 ms and signal-to-noise ratio of 900, and at the level of 92 % by the analysis of the light signals with rise-time of about 3 ms and signal-to-noise ratio of 30, under the requirement to detect 95 % of single events. These rejection efficiencies are compatible with extremely low background levels in the region of interest of neutrinoless double beta decay of {sup 100}Mo for enriched ZnMoO{sub 4} detectors, of the order of 10{sup -4} counts/(y keV kg). Pulse-shape parameters have been chosen on the basis of the performance of a real massive ZnMoO{sub 4} scintillating bolometer. Importance of the signal-to-noise ratio, correct finding of the signal start and choice of an appropriate sampling frequency are discussed. (orig.)

  11. Clinical value of 18F-FDG coincidence imaging for patients with fever of unknown origin

    International Nuclear Information System (INIS)

    Objective: The aim of this study was to assess the clinical value of 18F-fluorodeoxyglucose (FDG) coincidence imaging in the diagnosis of fever of unknown origin (FUO). Methods: Fifty-eight patients with FUO (temperature>38.3 degree C, fever more than 3 weeks) underwent SPECT imaging with 18F-FDG. Region of interest (ROI) was drawn over the lesions (L) and contralateral or adjacent normal tissue (B). The radioactivity ratio L/B was calculated for both benign and malignant pathologies and compared by t test. Results In 48 patients(83%), at least one site of abnormal 18F-FDG accumulation on SPECT was found, which led to the final diagnosis of malignant disease in 20 patients, and infectious or other benign disease in 23 patients. Five patients remained unknown.Four in 10 (17%) cases with negative 18F-FDG SPECT were later proven as infectious disease (2 with urinary tract infection, 2 with lymphadenitis); 3 were found to have connective tissue and collagen disease (1 with rheumatism, 1 with adult onset still's disease. 1 with systemic lupus erythematosus); while the last 3 remained unknown. The L/B ratio of benign foci was 1.93 ± 0.39, and that of malignant foci was 3.58 ± 1.01 (statistically significant difference with t=6.955. P18F-FDG coincidence imaging is valuable in the diagnosis for FUO. (authors)

  12. Cerebellar Dysfunction and Ataxia in Patients with Epilepsy: Coincidence, Consequence, or Cause?

    Science.gov (United States)

    Filip, Pavel; Bareš, Martin; Brázdil, Milan

    2016-01-01

    Basic epilepsy teachings assert that seizures arise from the cerebral cortex, glossing over infratentorial structures such as the cerebellum that are believed to modulate rather than generate seizures. Nonetheless, ataxia and other clinical findings in epileptic patients are slowly but inevitably drawing attention to this neural node. Tracing the evolution of this line of inquiry from the observed coincidence of cerebellar atrophy and cerebellar dysfunction (most apparently manifested as ataxia) in epilepsy to their close association, this review considers converging clinical, physiological, histological, and neuroimaging evidence that support incorporating the cerebellum into epilepsy pathology. We examine reports of still controversial cerebellar epilepsy, studies of cerebellar stimulation alleviating paroxysmal epileptic activity, studies and case reports of cerebellar lesions directly associated with seizures, and conditions in which ataxia is accompanied by epileptic seizures. Finally, the review substantiates the role of this complex brain structure in epilepsy whether by coincidence, as a consequence of deleterious cortical epileptic activity or antiepileptic drugs, or the very cause of the disease. PMID:27375960

  13. Space charge dominated beams

    International Nuclear Information System (INIS)

    After an introductory section on the relationship between emittance and beam Coulomb energy we discuss the properties of space charge dominated beams in progressive steps: from uniformly charged bunched beams to non-uniformly charged beams to correlation effects between particles (simulation beams or 'crystalline' beams). A practical application can be found in the beam dynamics of a high-current injector. The concept of correlation energy is of practical interest in computer simulation of high-brilliance beams, where one deals with an artificially enhanced two-particle Coulomb energy, if many real particles are combined into one simulation super-particle. This can be a source of non-physical emittance growth. (orig./HSI)

  14. Charge gradient microscopy

    Science.gov (United States)

    Hong, Seungbum; Tong, Sheng; Park, Woon Ik; Hiranaga, Yoshiomi; Cho, Yasuo; Roelofs, Andreas

    2014-01-01

    Here we present a simple and fast method to reliably image polarization charges using charge gradient microscopy (CGM). We collected the current from the grounded CGM probe while scanning a periodically poled lithium niobate single crystal and single-crystal LiTaO3 thin film on the Cr electrode. We observed current signals at the domains and domain walls originating from the displacement current and the relocation or removal of surface charges, which enabled us to visualize the ferroelectric domains at a scan frequency above 78 Hz over 10 μm. We envision that CGM can be used in high-speed ferroelectric domain imaging and piezoelectric energy-harvesting devices. PMID:24760831

  15. Interacting dark energy models as an approach for solving Cosmic Coincidence Problem

    Science.gov (United States)

    Shojaei, Hamed

    Understanding the dark side of the Universe is one of the main tasks of physicists. As there is no thorough understanding of nature of the dark energy, this area is full of new ideas and there may be several discoveries, theoretical or experimental, in the near future. We know that dark energy, though not detected directly, exists and it is not just an exotic idea. The presence of dark energy is required by the observation of the acceleration of the universe. There are several questions regarding dark energy. What is the nature of dark energy? How does it interact with matter, baryonic or dark? Why is the density of dark energy so tiny, i.e. why rhoΛ ≈ 10--120 M4Pl ? And finally why does its density have the same order of magnitude as the density of matter does at the present time? The last question is one form of what is known as the "Cosmic Coincidence Problem" and in this work, I have been investigating one way to resolve this issue. Observations of Type Ia supernovae indicate that we are in an accelerating universe. A matter-dominated universe cannot be accelerating. A good fit is obtained if we assume that energy density parameters are O Λ = 0.7 and Om = 0.3. Here O Λ is related to dark energy, or cosmological constant in ΛCDM model. At the same time data from Wilkinson Microwave Anisotropy Probe (WMAP) satellite and supernova surveys have placed a constraint on w, the equation of state for dark energy, which is actually the ratio of pressure and energy density. Any good theory needs to explain this coincidence problem and yields a value for w between -1.1 and -0.9. I have employed an interesting approach to solve this problem by assuming that there exists an interaction between dark energy and matter in the context of holographic dark energy. This interaction converts dark energy to matter or vice versa without violating the local conservation of energy in the universe. Holographic dark energy by itself indicates that the value of dark energy is related

  16. Sources for charged particles

    International Nuclear Information System (INIS)

    This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.)

  17. Charged conformal Killing spinors

    Energy Technology Data Exchange (ETDEWEB)

    Lischewski, Andree, E-mail: lischews@mathematik.hu-berlin.de [Humboldt-Universität zu Berlin, Institut für Mathematik, Rudower Chaussee 25, Room 1.310, D12489 Berlin (Germany)

    2015-01-15

    We study the twistor equation on pseudo-Riemannian Spin{sup c}-manifolds whose solutions we call charged conformal Killing spinors (CCKSs). We derive several integrability conditions for the existence of CCKS and study their relations to spinor bilinears. A construction principle for Lorentzian manifolds admitting CCKS with nontrivial charge starting from CR-geometry is presented. We obtain a partial classification result in the Lorentzian case under the additional assumption that the associated Dirac current is normal conformal and complete the classification of manifolds admitting CCKS in all dimensions and signatures ≤5 which has recently been initiated in the study of supersymmetric field theories on curved space.

  18. Gross Motor Coincidence Timing by Children with Learning Difficulties and Children Matched on Mean Chronological and Mental Age.

    Science.gov (United States)

    Jacklin, Susan M.

    1987-01-01

    This study examines the learning of a gross motor coincidence timing task by children with learning difficulties, compared with that by children of average intelligence of an equivalent chronological age and mental age. Results are discussed. (Author/MT)

  19. Charge configurations in viral proteins.

    OpenAIRE

    Karlin, S; Brendel, V

    1988-01-01

    The spatial distribution of the charged residues of a protein is of interest with respect to potential electrostatic interactions. We have examined the proteins of a large number of representative eukaryotic and prokaryotic viruses for the occurrence of significant clusters, runs, and periodic patterns of charge. Clusters and runs of positive charge are prominent in many capsid and core proteins, whereas surface (glyco)proteins frequently contain a negative charge cluster. Significant charge ...

  20. Phase space localization of a scalar charged particle

    CERN Document Server

    Semenov, A A

    2002-01-01

    The thesis is devoted to the phase space representation of relativistic quantum mechanics. For a class of observables with matrix-valued Weyl symbols proportional to the identity matrix, the Weyl-Wigner-Moyal formalism is proposed. The evolution equations are found to coincide with their counterparts in relativistic quantum mechanics with non-local Hamiltonian. The difference between the theories is connected with peculiarities of the constraints on the initial conditions. Effective increase in coherence between eigenstates of the Hamiltonian is found. Relativistic coherent states that take into account a non-trivial charge structure of the position and momentum operators and satisfy the charge superselection rule are considered. On this basis, the entangled coherent states are developed.

  1. Polarisation-based coincidence event discrimination: an in silico study towards a feasible scheme for Compton-PET

    Science.gov (United States)

    Toghyani, M.; Gillam, J. E.; McNamara, A. L.; Kuncic, Z.

    2016-08-01

    Current positron emission tomography (PET) systems use temporally localised coincidence events discriminated by energy and time-of-flight information. The two annihilation photons are in an entangled polarisation state and, in principle, additional information from the polarisation correlation of photon pairs could be used to improve the accuracy of coincidence classification. In a previous study, we demonstrated that in principle, the polarisation correlation information could be transferred to an angular correlation in the distribution of scattered photon pairs in a planar Compton camera system. In the present study, we model a source-phantom-detector system using Geant4 and we develop a coincidence classification scheme that exploits the angular correlation of scattered annihilation quanta to improve the accuracy of coincidence detection. We find a 22% image quality improvement in terms of the peak signal-to-noise ratio when scattered coincidence events are discriminated solely by their angular correlation, thus demonstrating the feasibility of this novel classification scheme. By integrating scatter events (both single-single and single-only) with unscattered coincidence events discriminated using conventional methods, our results suggest that Compton-PET may be a promising candidate for optimal emission tomographic imaging.

  2. Standardization of {sup 59}Fe 4πβ(LS)-γcoincidence counting with digital sampling method

    Energy Technology Data Exchange (ETDEWEB)

    Agusbudiman, A.; Lee, K. B.; Lee, J. M.; Park, T. S. [Korea University of Science and Technology (UST), Daejeon (Korea, Republic of)

    2014-11-15

    The radionuclide 59Fe decays with a half-life of 44.494(12) days, by several beta minus emission to the ground state and to four excited states of {sup 59}Co, mainly to the 1099 keV and 1291 keV (Bé et al., 2004). The activity of {sup 59}Fe was measured by 4 πβ(LS)-γ coincidence counting method with digital sampling technique. A gamma spectrometry analysis was also conducted to check the impurities of the source. As comparison, the activity were also measured by using the 4πβ(PC)-γ coincidence counting system and 4πβ (LS)-γ anti-coincidence method. The radionuclide 59Fe has been standardized using the 4πβ(LS)-γcoincidence counting with digital sampling method. The result was in a good agreement with the result from 4πβ(PC)-γ coincidence counting and the 4πβ(LS)-γ anti-coincidence method.

  3. Charged particle beams

    CERN Document Server

    Humphries, Stanley

    2013-01-01

    Detailed enough for a text and sufficiently comprehensive for a reference, this volume addresses topics vital to understanding high-power accelerators and high-brightness-charged particle beams. Subjects include stochastic cooling, high-brightness injectors, and the free electron laser. Humphries provides students with the critical skills necessary for the problem-solving insights unique to collective physics problems. 1990 edition.

  4. Stability of charged membranes

    OpenAIRE

    Bensimon, D; David, F.; Leibler, S.; Pumir, A.

    1990-01-01

    The electrostatic contribution to the bending elastic modulus of charged phospholipid bilayers in an ionic solution is computed. It is found to be the same for conducting and non-conducting membranes and is always stabilizing. This stability for free membranes is shown to be a simple consequence of the vanishing of the physical surface tension.

  5. Coincidence and coherent data analysis methods for gravitational wave bursts in a network of interferometric detectors

    International Nuclear Information System (INIS)

    Network data analysis methods are the only way to properly separate real gravitational wave (GW) transient events from detector noise. They can be divided into two generic classes: the coincidence method and the coherent analysis. The former uses lists of selected events provided by each interferometer belonging to the network and tries to correlate them in time to identify a physical signal. Instead of this binary treatment of detector outputs (signal present or absent), the latter method involves first the merging of the interferometer data and looks for a common pattern, consistent with an assumed GW waveform and a given source location in the sky. The thresholds are only applied later, to validate or not the hypothesis made. As coherent algorithms use more complete information than coincidence methods, they are expected to provide better detection performances, but at a higher computational cost. An efficient filter must yield a good compromise between a low false alarm rate (hence triggering on data at a manageable rate) and a high detection efficiency. Therefore, the comparison of the two approaches is achieved using so-called receiving operating characteristics (ROC), giving the relationship between the false alarm rate and the detection efficiency for a given method. This paper investigates this question via Monte Carlo simulations, using the network model developed in a previous article. Its main conclusions are the following. First, a three-interferometer network such as Virgo-LIGO is found to be too small to reach good detection efficiencies at low false alarm rates: larger configurations are suitable to reach a confidence level high enough to validate as true GW a detected event. In addition, an efficient network must contain interferometers with comparable sensitivities: studying the three-interferometer LIGO network shows that the 2-km interferometer with half sensitivity leads to a strong reduction of performances as compared to a network of three

  6. Analysis of the effect of true coincidence summing on efficiency calibration for an HP GE detector

    Energy Technology Data Exchange (ETDEWEB)

    Rodenas, J.; Gallardo, S.; Ballester, S.; Primault, V. [Valencia Univ. Politecnica, Dept. de Ingenieria Quimica y Nuclear (Spain); Ortiz, J. [Valencia Univ. Politecnica, Lab. de Radiactividad Ambiental (Spain)

    2006-07-01

    The H.P. (High Purity) Germanium detector is commonly used for gamma spectrometry in environmental radioactivity laboratories. The efficiency of the detector must be calibrated for each geometry considered. This calibration is performed using a standard solution containing gamma emitter sources. The usual goal is the obtaining of an efficiency curve to be used in the determination of the activity of samples with the same geometry. It is evident the importance of the detector calibration. However, the procedure presents some problems as it depends on the source geometry (shape, volume, distance to detector, etc.) and shall be repeated when these factors change. That means an increasing use of standard solutions and consequently an increasing generation of radioactive wastes. Simulation of the calibration procedure with a validated computer program is clearly an important auxiliary tool for environmental radioactivity laboratories. This simulation is useful for both optimising calibration procedures and reducing the amount of radioactivity wastes produced. The M.C.N.P. code, based on the Monte Carlo method, has been used in this work for the simulation of detector calibration. A model has been developed for the detector as well as for the source contained in a Petri box. The source is a standard solution that contains the following radionuclides: {sup 241}Am, {sup 109}Cd, {sup 57}Co, {sup 139}Ce, {sup 203}Hg, {sup 113}Sn, {sup 85}Sr, {sup 137}Cs, {sup 88}Y and {sup 60}Co; covering a wide energy range (50 to 2000 keV). However, there are two radionuclides in the solution ({sup 60}Co and {sup 88}Y) that emit gamma rays in true coincidence. The effect of the true coincidence summing produces a distortion of the calibration curve at higher energies. To decrease this effect some measurements have been performed at increasing distances between the source and the detector. As the true coincidence effect is observed in experimental measurements but not in the Monte Carlo

  7. Effects of Calcium Spikes in the Layer 5 Pyramidal Neuron on Coincidence Detection and Activity Propagation

    Science.gov (United States)

    Chua, Yansong; Morrison, Abigail

    2016-01-01

    The role of dendritic spiking mechanisms in neural processing is so far poorly understood. To investigate the role of calcium spikes in the functional properties of the single neuron and recurrent networks, we investigated a three compartment neuron model of the layer 5 pyramidal neuron with calcium dynamics in the distal compartment. By performing single neuron simulations with noisy synaptic input and occasional large coincident input at either just the distal compartment or at both somatic and distal compartments, we show that the presence of calcium spikes confers a substantial advantage for coincidence detection in the former case and a lesser advantage in the latter. We further show that the experimentally observed critical frequency phenomenon, in which action potentials triggered by stimuli near the soma above a certain frequency trigger a calcium spike at distal dendrites, leading to further somatic depolarization, is not exhibited by a neuron receiving realistically noisy synaptic input, and so is unlikely to be a necessary component of coincidence detection. We next investigate the effect of calcium spikes in propagation of spiking activities in a feed-forward network (FFN) embedded in a balanced recurrent network. The excitatory neurons in the network are again connected to either just the distal, or both somatic and distal compartments. With purely distal connectivity, activity propagation is stable and distinguishable for a large range of recurrent synaptic strengths if the feed-forward connections are sufficiently strong, but propagation does not occur in the absence of calcium spikes. When connections are made to both the somatic and the distal compartments, activity propagation is achieved for neurons with active calcium dynamics at a much smaller number of neurons per pool, compared to a network of passive neurons, but quickly becomes unstable as the strength of recurrent synapses increases. Activity propagation at higher scaling factors can be

  8. Spontaneous Emission of Charged Bosons from Supercritical Point Charges

    CERN Document Server

    Kim, Sang Pyo

    2013-01-01

    We study the spontaneous emission of charged bosons from supercritical Coulomb potentials and charged black holes. We find the exact emission rate from the Bogoliubov transformation by applying the tunneling boundary condition on the Jost functions at the asymptotic boundaries. The emission rate for charged bosons in the supercritical Coulomb potential increases as the charge $Z\\alpha > 1/2$ of the superatom and the energy of the bosons increase but is suppressed for large angular momenta. We discuss physical implications of the emission of charged bosons from superatoms and charged black holes.

  9. Decay of electric charge on corona charged polyethylene

    International Nuclear Information System (INIS)

    In this paper, the surface potential decay of corona-charged low density polyethylene (LDPE) films has been investigated. It has been found that for the same sample thickness the faster decay occurs in the sample with a higher charging voltage. For the same charging voltage, the surface potential in the thinner sample shows rapid decay. Our new evidence from both the surface potential measurement on multilayer samples and space charge measurement suggests the surface potential decay is a bulk limited process. More importantly, space charge measurement indicates double injection has taken place during corona charging process.

  10. Characterizations of double pulsing in neutron multiplicity and coincidence counting systems

    Science.gov (United States)

    Koehler, Katrina E.; Henzl, Vladimir; Croft, Stephen S.; Henzlova, Daniela; Santi, Peter A.

    2016-10-01

    Passive neutron coincidence/multiplicity counters are subject to non-ideal behavior, such as double pulsing and dead time. It has been shown in the past that double-pulsing exhibits a distinct signature in a Rossi-alpha distribution, which is not readily noticed using traditional Multiplicity Shift Register analysis. However, it has been assumed that the use of a pre-delay in shift register analysis removes any effects of double pulsing. In this work, we use high-fidelity simulations accompanied by experimental measurements to study the effects of double pulsing on multiplicity rates. By exploiting the information from the double pulsing signature peak observable in the Rossi-alpha distribution, the double pulsing fraction can be determined. Algebraic correction factors for the multiplicity rates in terms of the double pulsing fraction have been developed. We discuss the role of these corrections across a range of scenarios.

  11. Time-and-frequency gated photon coincidence counting; a novel multidimensional spectroscopy tool

    CERN Document Server

    Dorfman, Konstantin E

    2016-01-01

    Coherent multidimensional optical spectroscopy techniques are broadly applied across the electromagnetic spectrum ranging from NMR to the UV. These reveal properties of matter through correlation plots of signal fields generated in response to sequences of short pulses with variable delays. Here we discuss a new class of multidimensional techniques obtained by time-and-frequency resolved photon coincidence counting measurements of N photons which constitutes a 2N dimensional spectrum. A compact description of these signals is developed based on time ordered superoperators rather than the normally ordered ordinary operators used in Glauber's photon counting formalism. The independent control of the time and frequency gate parameters reveals details of matter dynamics not available otherwise. Application to an anharmonic oscillator model with fluctuating energy and anharmonicity demonstrates the power of these signals.

  12. Do climate extreme events foster violent civil conflicts? A coincidence analysis

    Science.gov (United States)

    Schleussner, Carl-Friedrich; Donges, Jonathan F.; Donner, Reik V.

    2014-05-01

    Civil conflicts promoted by adverse environmental conditions represent one of the most important potential feedbacks in the global socio-environmental nexus. While the role of climate extremes as a triggering factor is often discussed, no consensus is yet reached about the cause-and-effect relation in the observed data record. Here we present results of a rigorous statistical coincidence analysis based on the Munich Re Inc. extreme events database and the Uppsala conflict data program. We report evidence for statistically significant synchronicity between climate extremes with high economic impact and violent conflicts for various regions, although no coherent global signal emerges from our analysis. Our results indicate the importance of regional vulnerability and might aid to identify hot-spot regions for potential climate-triggered violent social conflicts.

  13. High mass-resolution electron-ion-ion coincidence measurements on core-excited organic molecules

    CERN Document Server

    Tokushima, T; Senba, Y; Yoshida, H; Hiraya, A

    2001-01-01

    Total electron-ion-ion coincidence measurements on core excited organic molecules have been carried out with high mass resolution by using multimode (reflectron/linear) time-of-flight mass analyzer. From the ion correlation spectra of core excited CH sub 3 OH and CD sub 3 OH, the reaction pathway to form H sub 3 sup + (D sub 3 sup +) is identified as the elimination of three H (D) atoms from the methyl group, not as the inter-group (-CH sub 3 and -OH) interactions. In a PEPIPICO spectrum of acetylacetone (CH sub 3 COCH sub 2 COCH sub 3) measured by using a reflectron TOF, correlations between ions up to mass number 70 with one-mass resolution was recorded.

  14. Calibration and experimental comparison of the active well coincidence counter and PHONID-II

    International Nuclear Information System (INIS)

    A team from EURATOM-Luxembourg, JRC-Ispra, Los Alamos, and International Atomic Energy Agency (IAEA) has performed measurements to directly compare the Active Well Coincidence Counter (AWCC) with the PHONID-II for the assay of highly enriched uranium (HEU). The comparison included an evaluation of counting rates, sensitivity, accuracy, linearity, stability, and matrix effects. Samples used in the evaluation included highly enriched uranium metal, U3O8 U-Al alloy plates, UF4, and (uranium/thorium) coated particles covering the mass range from a few grams up to about 5 kg of 235U. These materials are typical of the HEU samples under inspector verification. This report gives the results of the intercomparison as well as calibration information for the above material categories

  15. Detection of the Cerenkov effect of β particles in a liquid by rapid photomultipliers in coincidence

    International Nuclear Information System (INIS)

    An electronic assembly in the nanosecond region was studied for the detection of weak light pulses due to the Cerenkov effect, which an ordinary photomultiplier represents by pulses of a level comparable to that of the thermal noise at ambient temperature. The elimination of these extraneous counts was effected by rapid coincidence between two photomultipliers viewing the same source of light. This arrangement, eliminating the cooling normally used in this type of detection, permits a significant reduction of the volume and weight of the apparatus used with the Cerenkov detector proper. The apparatus described has been applied to the detection of β-emitters in solution; it has permitted the measurement of Sr-Y activity in water, in concentrations at the MCP level. (author)

  16. Design and performance of the Savannah River Site Billet Active Well Coincidence Counter

    International Nuclear Information System (INIS)

    The Savannah River Site (SRS) has acquired, installed, and tested a custom-built Billet Active Well (neutron) Coincidence Counter (BAWCC). The BAWCC is used to make accountability measurements of the 235U content of U-Al coextrusion billets in the SRS fuel fabrication facility. The instrument design incorporates a unique center-source configuration, with two moderated americium-lithium (AmLi) neutron sources located in a central spindle that inserts through the center hole of the U-Al billets. This configuration, a result of earlier experimental studies at SRS, yields improved response and precision for billet assay when compared to the standard AWCC source arrangement. Initial tests of the BAWCC at SRS have yielded one-sigma uncertainties of 0.8--1.0% for a fifteen-minute assay. This paper will describe the design, testing program and performance characteristics of the BAWCC

  17. Reduction of elevated IGF-1 levels in coincident amyotrophic lateral sclerosis and acromegaly.

    Science.gov (United States)

    Pereira, Erlick A C; Turner, Martin R; Wass, John A H; Talbot, Kevin

    2010-01-01

    We report a patient presenting with ALS in whom acromegaly was later confirmed. Insulin-like growth factor-1 (IGF-1) has been tried in the treatment of ALS and despite equivocal results from clinical trials, efforts have continued to try to harness the significant positive effects on motor neuron growth observed in vitro and in survival of mouse models of the disease. One subsequent study has reported an association between higher circulating serum IGF-1 levels and longer disease duration in ALS patients. Concern therefore arose in our case that treatment of the acromegaly with a somatostatin analogue might adversely affect the natural course of his ALS through lowering of potentially beneficial IGF-1 levels. Through clinical observation and prognostic modelling we suggest that this concern was unfounded. The potential interaction of these two rarely coincident disorders in our patient is discussed.

  18. γ-Particle coincidence technique for the study of nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Zagatto, V.A.B., E-mail: vinicius.zagatto@gmail.com [Instituto de Física da Universidade de São Paulo (Brazil); Oliveira, J.R.B.; Allegro, P.R.P.; Chamon, L.C.; Cybulska, E.W.; Medina, N.H.; Ribas, R.V.; Seale, W.A.; Silva, C.P.; Gasques, L.R. [Instituto de Física da Universidade de São Paulo (Brazil); Zahn, G.S.; Genezini, F.A.; Shorto, J.M.B. [Instituto de Pesquisas Energéticas e Nucleares (Brazil); Lubian, J.; Linares, R. [Instituto de Física da Universidade Federal Fluminense (Brazil); Toufen, D.L. [Instituto Federal de Educação, Ciência e Tecnologia (Brazil); Silveira, M.A.G. [Centro Universitário da FEI (Brazil); Rossi, E.S. [Centro Universitário FIEO – UNIFIEO (Brazil); Nobre, G.P. [Lawrence Livermore National Laboratory (United States)

    2014-06-01

    The Saci-Perere γ ray spectrometer (located at the Pelletron AcceleratorLaboratory – IFUSP) was employed to implement the γ-particle coincidence technique for the study of nuclear reaction mechanisms. For this, the {sup 18}O+{sup 110}Pd reaction has been studied in the beam energy range of 45–54 MeV. Several corrections to the data due to various effects (energy and angle integrations, beam spot size, γ detector finite size and the vacuum de-alignment) are small and well controlled. The aim of this work was to establish a proper method to analyze the data and identify the reaction mechanisms involved. To achieve this goal the inelastic scattering to the first excited state of {sup 110}Pd has been extracted and compared to coupled channel calculations using the São Paulo Potential (PSP), being reasonably well described by it.

  19. Time-and-frequency-gated photon coincidence counting; a novel multidimensional spectroscopy tool

    Science.gov (United States)

    Dorfman, Konstantin E.; Mukamel, Shaul

    2016-08-01

    Coherent multidimensional optical spectroscopy is broadly applied across the electromagnetic spectrum ranging from NMR to UV. These techniques reveal the properties of matter through the correlation plots of signal fields generated in response to sequences of short pulses with variable delays. Here we discuss a new class of multidimensional techniques obtained by the time-and-frequency-resolved photon coincidence counting measurements of N photons, which constitute a 2N dimensional spectrum. A compact description of these signals is developed based on time-ordered superoperators rather than the normally ordered ordinary operators used in Glauber's photon counting formalism. The independent control of the time and frequency gate parameters reveals fine details of matter dynamics not available otherwise. These signal are illustrated for application to an anharmonic oscillator model with fluctuating energy and anharmonicity.

  20. New approach to the kinematic coincidence method in heavy ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Casini, G.; Maurenzig, P.R.; Olmi, A.; Stefanini, A.A.

    1989-05-01

    A new approach to the kinematic coincidence method (KCM) is proposed, which makes use of the whole kinematic information of heavy ion experiments in a self-consistent way. It takes advantage of the overdetermination of the measurement yielding not only solutions for the primary masses of the fragments, but also 'improved values' for their velocity vectors. A statistical variable, ..delta../sub v/, indicates to what extent the secondary quantities violate the kinematics of the reaction. The ability of the present approach to reproduce the primary quantities of a binary or ternary reaction is compared with that of older approaches on the basis of realistic Monte Carlo simulations. The background of incompletely detected events of higher multiplicity can be effectively subtracted using the results of the present analysis.

  1. A new approach to the kinematic coincidence method in heavy ion reactions

    Science.gov (United States)

    Casini, G.; Maurenzig, P. R.; Olmi, A.; Stefanini, A. A.

    1989-05-01

    A new approach to the kinematic coincidence method (KCM) is proposed, which makes use of the whole kinematic information of heavy ion experiments in a self-consistent way. It takes advantage of the overdetermination of the measurement yielding not only solutions for the primary masses of the fragments, but also "improved values" for their velocity vectors. A statistical variable, Δν, indicates to what extent the secondary quantities violate the kinematics of the reaction. The ability of the present approach to reproduce the primary quantities of a binary or ternary reaction is compared with that of older approaches on the basis of realistic Monte Carlo simulations. The background of incompletely detected events of higher multiplicity can be effectively subtracted using the results of the present analysis.

  2. Digital data recording system for the 4 πβ-γ coincidence apparatus

    International Nuclear Information System (INIS)

    The data recording system for the 4πβ-γ coincidence apparatus consists of three scalers, a timer, a day-clock, a print control unit and a Hewlett-Packard printer. The print control unit serves as an interface unit as well as generates necessary electronic commands for starting, scanning, recycling and actuating the printer. It also generates the run number and identification number. It has made the data recording and recycling completely automatic. The report describes the data recording system which has been in continuous use since March 1973. Brief description of the scalers, the timer, the day-clock and the printer is given. The print control unit is described and the working of the data handling, scanning and cycle counting sections is explained. (author)

  3. Coincidence spectroscopy of high-lying Rydberg states produced in strong laser fields

    CERN Document Server

    Larimian, Seyedreza; Lemell, Christoph; Yoshida, Shuhei; Nagele, Stefan; Maurer, Raffael; Baltuška, Andrius; Burgdörfer, Joachim; Kitzler, Markus; Xie, Xinhua

    2016-01-01

    We report on the measurement of electron emission after the interaction of strong laser pulses with atoms and molecules. These electrons originate from high-lying Rydberg states with quantum numbers up to $n \\lesssim 120$ formed by frustrated field ionization. Simulations show that both tunneling ionization by a weak dc field and photoionization by the black-body radiation contribute to delayed electron emission on the nano- to microsecond scale. We measured ionization rates from these Rydberg states by coincidence spectroscopy. Further, the dependence of the Rydberg-state production on the ellipticity of the driving laser field proves that such high-lying Rydberg states are populated through electron recapture. The present experiment provides detailed quantitative information on Rydberg production by frustrated field ionization.

  4. Multi-coincidence measurements in gas-phase amino acid alanine after valence level ionization

    International Nuclear Information System (INIS)

    Full text: The first chiral amino acids having distinct enantiomeric structures is the alanine. Therefore the study of such molecules is important for developing our understanding of this class of molecule. In this work, we report coincidence measurements between photoelectron and photoion, and total ion yield (TIY) measurements after valence level ionization of D,L-alanine in gas phase. The experiments were performed at the Brazilian Synchrotron Light Source (LNLS) at the Toroidal Grating Monochromator beamline (D0-5A TGM) in the 12-35 eV energy range. The end-station of the beamline is composed by a time-of-flight (TOF) spectrometer specially build for the photoelectron-photoion-photoion (PEPIPICO) measurements. The TIY have been compared with valence photoelectron spectra recorded with synchrotron radiation reported in the literature and have been discussed in a comparative form. The results will be presented during the conference

  5. Estimation of residual plutonium oxide in empty containers using neutron well coincidence counting

    International Nuclear Information System (INIS)

    Neutron well coincidence counting (NWCC) technique is a relatively fast and non-destructive technique for plutonium analysis. This technique has been used for the analysis of residual plutonium oxide in empty containers. Estimation of plutonium oxide left in the empty container is very difficult by using other techniques such as potentiometry, coulometry etc. as all these techniques need tedious and time taking sample preparation processes involving separation, dissolution, accurate weighing etc. NWCC was found to be very useful technique is this analysis as no sample preparation was needed and sample can be counted directly in double sealed packet. Over 180 empty containers have been analyzed by this technique with 5% accuracy and precision. (author)

  6. Coincidence, historical repetition, and self-knowledge: Jung, Vico, and Joyce.

    Science.gov (United States)

    Verene, Donald Phillip

    2002-07-01

    Jung develops synchronicity as an a causal principle of connection by recounting various examples of meaningful coincidence from experience and by analysing various systems of divination, notably the I Ching. Philosophical theory of causality has given no significant attention to synchronicity; the events of synchronicity are regarded as chance. The Neapolitan philosopher Giambattista Vico (1668-1744) developed a doctrine of historical experience and of self-knowledge that grounds the phenomenon of synchronicity in a metaphysics. James Joyce employed Vico's conception of language and historical cycles as the basis of Joyce's final literary work, Finnegans Wake. Vico's metaphysical sense of synchronicity and Joyce's literary formulation offer a grounding of this principle in non-divinatory sources in modern Western thought, something which Jung's discussion does not provide. These philosophical and literary perspectives complement Jung's to offer an expanded context in which to recognize synchronicity and to make sense of it. PMID:12174547

  7. True coincidence summing corrections for an extended energy range HPGe detector

    Energy Technology Data Exchange (ETDEWEB)

    Venegas-Argumedo, Y. [Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Chihuahua, Chih 31109 (Mexico); M.S. Student at CIMAV (Mexico); Montero-Cabrera, M. E., E-mail: elena.montero@cimav.edu.mx [Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Chihuahua, Chih 31109 (Mexico)

    2015-07-23

    True coincidence summing (TCS) effect for natural radioactive families of U-238 and Th-232 represents a problem when an environmental sample with a close source-detector geometry measurement is performed. By using a certified multi-nuclide standard source to calibrate an energy extended range (XtRa) HPGe detector, it is possible to obtain an intensity spectrum slightly affected by the TCS effect with energies from 46 to 1836 keV. In this work, the equations and some other considerations required to calculate the TCS correction factor for isotopes of natural radioactive chains are described. It is projected a validation of the calibration, performed with the IAEA-CU-2006-03 samples (soil and water)

  8. 3D Coincidence Imaging Disentangles Intense Field Double Detachment of SF6(–).

    Science.gov (United States)

    Kandhasamy, Durai Murugan; Albeck, Yishai; Jagtap, Krishna; Strasser, Daniel

    2015-07-23

    The efficient intense field double detachment of molecular anions observed in SF6(–) is studied by 3D coincidence imaging of the dissociation products. The dissociation anisotropy and kinetic energy release distributions are determined for the energetically lowest double detachment channel by virtue of disentangling the SF5(+) + F fragmentation products. The observed nearly isotropic dissociation with respect to the linear laser polarization and surprisingly high kinetic energy release events suggest that the dissociation occurs on a highly excited state. Rydberg (SF6(+))* states composed of a highly repulsive dication core and a Rydberg electron are proposed to explain the observed kinetic energy release, accounting also for the efficient production of all possible cationic fragments at equivalent laser intensities. PMID:26098224

  9. Coincidence Doppler broadening study of Eurofer 97 irradiated in spallation environment

    Energy Technology Data Exchange (ETDEWEB)

    Sabelová, V., E-mail: veronika.sabelova@stuba.sk [Institute of Nuclear and Physical Engineering, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology in Bratislava, Ilkovičova 3, 81219 Bratislava (Slovakia); Laboratory for Nuclear Materials, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Kršjak, V. [Laboratory for Nuclear Materials, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Kuriplach, J. [Department of Low Temperature Physics, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, 18000 Prague 8 (Czech Republic); Dai, Y. [Laboratory for Nuclear Materials, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Slugeň, V. [Institute of Nuclear and Physical Engineering, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology in Bratislava, Ilkovičova 3, 81219 Bratislava (Slovakia)

    2015-03-15

    The behavior of transmutation helium during isochronal annealing of irradiated Eurofer 97 was investigated using coincidence Doppler broadening spectroscopy (CDBS). The investigated ferritic martensitic steel was irradiated in 2000 and 2001 in the frame of the STIP-II project at the Swiss neutron spallation source (SINQ) (irradiation with neutrons and protons) at the Paul Scherrer Institute (PSI). During isochronal annealing experiment, coarsening of vacancy clusters and/or growth of helium bubbles was observed at T ⩾ 500 °C. This process causes an increase of low-momentum annihilation events and related increase of the S parameter during thermal treatment of material. On the other hand, the maximum concentration of helium in small vacancy clusters (V{sub n}) was observed after annealing at 400 °C, where an excellent correlation with the calculated CDBS profiles of V{sub n} + He{sub m} clusters was found.

  10. Coincidence Doppler broadening study of Eurofer 97 irradiated in spallation environment

    Science.gov (United States)

    Sabelová, V.; Kršjak, V.; Kuriplach, J.; Dai, Y.; Slugeň, V.

    2015-03-01

    The behavior of transmutation helium during isochronal annealing of irradiated Eurofer 97 was investigated using coincidence Doppler broadening spectroscopy (CDBS). The investigated ferritic martensitic steel was irradiated in 2000 and 2001 in the frame of the STIP-II project at the Swiss neutron spallation source (SINQ) (irradiation with neutrons and protons) at the Paul Scherrer Institute (PSI). During isochronal annealing experiment, coarsening of vacancy clusters and/or growth of helium bubbles was observed at T ⩾ 500 °C. This process causes an increase of low-momentum annihilation events and related increase of the S parameter during thermal treatment of material. On the other hand, the maximum concentration of helium in small vacancy clusters (Vn) was observed after annealing at 400 °C, where an excellent correlation with the calculated CDBS profiles of Vn + Hem clusters was found.

  11. Observation of autoionization in O 2 by an electron-electron coincidence method

    Science.gov (United States)

    Doering, J. P.; Yang, J.; Cooper, J. W.

    1995-01-01

    A strong transition to an autoionizing stata has been observed in O 2 at 16.83 ± 0.11 eV by means of a new electron-electron conincidence method. The method uses the fact that electrons arising from autoionizing states appear at a constant energy loss corresponding to the excitation energy of the autoionizing state rather than at a constant ionization potential as do electrons produced by direct ionization. Comparison of the present data with previous photoionization studies suggests that the autoionizing O 2 state is the same state deduced to be responsible for abnormal vibrational intensities in the O 2+X 2Πg ground state when 16.85 eV Ne(I) photons are used. These electron-electron coincidence experiments provide a direct new method for the study of autoionization produced by electron impact.

  12. Growth of coincident site lattice matched semiconductor layers and devices on crystalline substrates

    Science.gov (United States)

    Norman, Andrew G; Ptak, Aaron J

    2013-08-13

    Methods of fabricating a semiconductor layer or device and said devices are disclosed. The methods include but are not limited to providing a substrate having a crystalline surface with a known lattice parameter (a). The method further includes growing a crystalline semiconductor layer on the crystalline substrate surface by coincident site lattice matched epitaxy, without any buffer layer between the crystalline semiconductor layer and the crystalline surface of the substrate. The crystalline semiconductor layer will be prepared to have a lattice parameter (a') that is related to the substrate lattice parameter (a). The lattice parameter (a') maybe related to the lattice parameter (a) by a scaling factor derived from a geometric relationship between the respective crystal lattices.

  13. The underwater coincidence counter for plutonium measurements in mixed-oxide fuel assemblies manual

    Energy Technology Data Exchange (ETDEWEB)

    G. W. Eccleston; H. O. Menlove; M. Abhold; M. Baker; J. Pecos

    1999-05-01

    This manual describes the Underwater Coincidence Counter (UWCC) that has been designed for the measurement of plutonium in mixed-oxide (MOX) fuel assemblies prior to irradiation. The UWCC uses high-efficiency {sup 3}He neutron detectors to measure the spontaneous-fission and induced-fission rates in the fuel assembly. Measurements can be made on MOX fuel assemblies in air or underwater. The neutron counting rate is analyzed for singles, doubles, and triples time correlations to determine the {sup 240}Pu effective mass per unit length of the fuel assembly. The system can verify the plutonium loading per unit length to a precision of less than 1% in a measurement time of 2 to 3 minutes. System design, components, performance tests, and operational characteristics are described in this manual.

  14. Molecular photoionisation using synchrotron radiation. Photoelectron photoion coincidence and circular dichroism

    CERN Document Server

    Garcia-Macias, G A

    2002-01-01

    The first ionisation potential of the CF sub 3 radical has been determined in this work from the appearance potential of the CF sub 3 sup + fragment, formed in the photofragmentation of CF sub 3 Br. In obtaining this value special care has been taken in removing the contributions from second order light and internal energy of the fragmenting parent ion. The resulting ionisation potential was found to be in very good agreement with a number of recent theoretical calculations. The valence photoelectron spectra of three monoterpenes such as limonene, carvone and camphor have been recorded along with their mass spectra taken in coincidence with energy selected photoelectrons, providing information about state selected parent ion fragmentation channels. A new photoelectron spectrometer based on the Alien box design has been studied by ray-tracing simulations. It will include a two dimensional position sensitive detector system consisting in two micro channel plates in a chevron stack and a delay-line anode to enco...

  15. Hypohidrotic ectodermal dysplasia and immunodeficiency with coincident NEMO and EDA mutations.

    Science.gov (United States)

    Keller, Michael D; Petersen, Maureen; Ong, Peck; Church, Joseph; Risma, Kimberly; Burham, Jon; Jain, Ashish; Stiehm, E Richard; Hanson, Eric P; Uzel, Gulbu; Deardorff, Matthew A; Orange, Jordan S

    2011-01-01

    Ectodermal dysplasias (ED) are uncommon genetic disorders resulting in abnormalities in ectodermally derived structures. Many ED-associated genes have been described, of which ectodysplasin-A (EDA) is one of the more common. The NF-κB essential modulator (NEMO encoded by the IKBKG gene) is unique in that mutations result in severe humoral and cellular immunologic defects in addition to ED. We describe three unrelated kindreds with defects in both EDA and IKBKG resulting from X-chromosome crossover. This demonstrates the importance of thorough immunologic consideration of patients with ED even when an EDA etiology is confirmed, and raises the possibility of a specific phenotype arising from coincident mutations in EDA and IKBKG. PMID:22566850

  16. Evaluation Of The Coincidence Of Male Pattern Baldness And Pityrosporum Group Of Fungus In Iran

    Directory of Open Access Journals (Sweden)

    Javanbakht Arash

    2002-01-01

    Full Text Available The aetilogy of male pattern baldness (MPB is not clearly found yet. The present study has been designed to determine if three is a significant statistical coincidence between MPB and pityrosporm group of fungal infection. This cross-sectional study covers 50 men with the diagnosis of MPB who visited the dermatology clinic of Qaem hospital of Mashhad Medical University as the case group and 43 men with no evidence of MPB as the control group. A questionnaire was filled out for each person of the two groups and mycological sampling was done from three parts of the case group scalp (bald, balding, intact areas and two parts of the control group scalp (vertex and parietal. All the data were analysed using the software SPSS 10.00 and Chi-square, Pearson Chi-square and Friedman tests. Results showed that there was no difference between different degrees of infection in the intact area (p>0.05. Among the three parts of the case group scalp, bald area had the highest degree of infection (p<0.001. The degree of infection in the bald area of the case group scalp was higher than that of the vertex area of the control group scalp (p<0.001, while there was no difference between the degrees of infection in the intact area of the case group scalp and the parietal area of the control group scalp (p>0.05. This study supports some previous studies that claimed that there might be coincidence between MPB and pityrosporum fungal infection.

  17. Alpha particle spectra in coincidence with normal and superdeformed states in {sup 150}Tb

    Energy Technology Data Exchange (ETDEWEB)

    Viesti, G.; Lunardon, M.; Bazzacco, D. [dell`Universita, Padova (Italy)]|[INFN, Padova (Italy)] [and others

    1996-12-31

    The study of correlations between particle evaporation from highly excited compound nuclei at large angular momenta and the states in the final evaporation residues (ER) is a field of investigation which has been opened, in the last years, with the advent of the new large {gamma}-ray arrays. It is now possible to correlate the evaporation spectra to various bands with shapes ranging from spherical to superdeformed (SD) in the same final nucleus. It is generally accepted that the particle evaporation from the compound nucleus is chaotic and that only in the near-yrast {gamma} cascade, where the feeding of different classes of states takes place, the ordered motion is restored. The sensitivity of the particle spectra on the feeding of specific states in the residual nuclei can be taken as an indication that additional degrees of freedom might be important in the evaporation process or that particular regions of the phase space open to the decay populate preferentially some selected structures in the final cold nucleus. This latter point is important for the understanding of the feeding mechanism of SD states. Several experiments performed so far did not find a clear dependence of the shapes of the particle spectra on the excited states having different deformations in the ER. For example, the proton spectra in coincidence with transitions in the SD bands of {sup 133}Nd and {sup 152}Dy nuclei were found to be similar to those in coincidence with transitions in the normal deformed (ND) bands. Alpha particles have been proposed since long as a sensitive probe of the deformation of the emitting nucleus. Results are presented here of an experiment in which the authors have measured the energy spectra of alpha particles associated with different classes of states (ND and SD) in the {sup 150}Tb nucleus populated in the reaction {sup 37}Cl({sup 120}Sn, {alpha}3n{gamma}){sup 150}Tb.

  18. High Voltage Charge Pump

    KAUST Repository

    Emira, Ahmed A.

    2014-10-09

    Various embodiments of a high voltage charge pump are described. One embodiment is a charge pump circuit that comprises a plurality of switching stages each including a clock input, a clock input inverse, a clock output, and a clock output inverse. The circuit further comprises a plurality of pumping capacitors, wherein one or more pumping capacitors are coupled to a corresponding switching stage. The circuit also comprises a maximum selection circuit coupled to a last switching stage among the plurality of switching stages, the maximum selection circuit configured to filter noise on the output clock and the output clock inverse of the last switching stage, the maximum selection circuit further configured to generate a DC output voltage based on the output clock and the output clock inverse of the last switching stage.

  19. Electrically charged curvaton

    CERN Document Server

    D'Onofrio, Michela; Rajantie, Arttu

    2012-01-01

    We consider the possibility that the primordial curvature perturbation was generated through the curvaton mechanism from a scalar field with an electric charge, or precisely the Standard Model U(1) weak hypercharge. This links the dynamics of the very early universe concretely to the Standard Model of particle physics, and because the coupling strength is known, it reduces the number of free parameters in the curvaton model. We show that the model is compatible with CMB observations for Hubble rate $H_* > 10^8 GeV$ and curvaton mass $m > 10^{-2}H_*$. Charge fluctuations generated during inflation are screened by electron-positron pairs, and therefore do not violate observational constraints. The interaction with the gauge field leads to interesting dynamics after inflation, including resonant preheating, with potentially highly non-trivial observational consequences, which should be studied more carefully using numerical field theory simulations.

  20. Hidden Charged Dark Matter

    CERN Document Server

    Feng, Jonathan L; Tu, Huitzu; Yu, Hai-Bo

    2009-01-01

    We examine the possibility that dark matter is hidden, that is, neutral under all standard model gauge interactions, but charged under an exact U(1) gauge symmetry of the hidden sector. Such candidates are predicted in simple WIMPless models, supersymmetric models in which hidden dark matter has the desired thermal relic density for a wide range of masses. Hidden charged dark matter has many potentially disastrous implications for astrophysics: (1) bound state formation and Sommerfeld-enhanced annihilation after chemical freeze out may destroy its relic density, (2) similar effects greatly enhance dark matter annihilation in protohalos at redshifts of z ~ 30, (3) Compton scattering off hidden photons delays kinetic decoupling, suppressing small scale structure, and (4) Rutherford scattering makes such dark matter self-interacting and collisional, potentially violating constraints from the Bullet Cluster and the observed morphology of galactic halos. We show that all of these constraints are satisfied and are ...

  1. Controlling charge on levitating drops.

    Science.gov (United States)

    Hilger, Ryan T; Westphall, Michael S; Smith, Lloyd M

    2007-08-01

    Levitation technologies are used in containerless processing of materials, as microscale manipulators and reactors, and in the study of single drops and particles. Presented here is a method for controlling the amount and polarity of charge on a levitating drop. The method uses single-axis acoustic levitation to trap and levitate a single, initially neutral drop with a diameter between 400 microm and 2 mm. This drop is then charged in a controllable manner using discrete packets of charge in the form of charged drops produced by a piezoelectric drop-on-demand dispenser equipped with a charging electrode. The magnitude of the charge on the dispensed drops can be adjusted by varying the voltage applied to the charging electrode. The polarity of the charge on the added drops can be changed allowing removal of charge from the trapped drop (by neutralization) and polarity reversal. The maximum amount of added charge is limited by repulsion of like charges between the drops in the trap. This charging scheme can aid in micromanipulation and the study of charged drops and particles using levitation. PMID:17580951

  2. General 2 charge geometries

    CERN Document Server

    Taylor, M

    2006-01-01

    Two charge BPS horizon free supergravity geometries are important in proposals for understanding black hole microstates. In this paper we construct a new class of geometries in the NS1-P system, corresponding to solitonic strings carrying fermionic as well as bosonic condensates. Such geometries are required to account for the full microscopic entropy of the NS1-P system. We then briefly discuss the properties of the corresponding geometries in the dual D1-D5 system.

  3. Transfer ionization cross-sections measured in collisions of highly charged argon ions with neon target

    Institute of Scientific and Technical Information of China (English)

    MA; Xinwen(马新文); LIU; Huiping; (刘惠萍); CHEN; Ximeng; (陈熙萌); YANG; Zhihu; (杨治虎); SHEN; Ziyong; (申自勇); WANG; Youde; (王友德); YU; Deyang; (于得洋); CAI; Xiaohong; (蔡晓红); LIU; Zhaoyuan; (刘兆远)

    2003-01-01

    Multiple electron transfer processes are studied for Arq+ + Ne (q = 8, 9, 11, 12) collisions by using multi-parameter coincidence techniques. Various electron transfer processes are identified experimentally and the related cross-sections are measured. The dependence of transfer ionization cross-sections on the recoil charge states is compared with the results from the modified molecular classical overbarrier model. It is found that the modified model described the experimental results reasonably.

  4. K-Vacancy Production in the Collision of Highly Charged Relativistic Ions With Heavy Atoms

    OpenAIRE

    Khabibullaev, P. K.

    2000-01-01

    A general expression for the cross section of the inelastic collision of relativistic highly charged ion with heavy (relativistic) atoms is obtained using the generalized eikonal approximation. In the ultrarelativistic limit, the obtained formula coincides with a known exact one. As an application of the obtained result, probability and cross section of the K-vacany production in the U92+ - U91+ collision are calculated.

  5. P-V criticality of charged AdS black holes

    OpenAIRE

    Kubiznak, David; Robert B. Mann

    2012-01-01

    Treating the cosmological constant as a thermodynamic pressure and its conjugate quantity as a thermodynamic volume, we reconsider the critical behaviour of charged AdS black holes. We complete the analogy of this system with the liquid-gas system and study its critical point, which occurs at the point of divergence of specific heat at constant pressure. We calculate the critical exponents and show that they coincide with those of the Van der Waals system.

  6. Distributed charging of electrical assets

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Soumyadip; Phan, Dung; Sharma, Mayank; Wu, Chai Wah; Xiong, Jinjun

    2016-02-16

    The present disclosure relates generally to the field of distributed charging of electrical assets. In various examples, distributed charging of electrical assets may be implemented in the form of systems, methods and/or algorithms.

  7. Study of Deformation Effects in the Charged Particle Emission from 46Ti*

    Science.gov (United States)

    Brekiesz, M.; Papka, P.; Maj, A.; Kmiecik, M.; Beck, C.; Bednarczyk, P.; Grebosz, J.; Haas, F.; Meczynski, W.; Rauch, V.; Rousseau, M.; Zafra, A. Sanchez I.; Styczen, J.; Thummerer, S.; Zieblinski, M.; Zuber, K.

    2005-04-01

    The 46Ti* compound nucleus, as populated by the fusion--evaporation reaction 27Al + 19F at the bombarding energy of 144MeV, has been investigated by charged particle spectroscopy using the multidetector array ICARE at the VIVITRON tandem facility of the IReS (Strasbourg). The light charged particles have been measured in coincidence with evaporation residues. The CACARIZO} code, a Monte Carlo implementation of the statistical model code CASCADE, has been used to calculate the spectral shapes of evaporated α -particles which are compared with the experimental spectra. This comparison indicates the possible signature of large deformations of the compound nucleus.

  8. Study of Deformation Effects in the Charged Particle Emission from 46Ti

    CERN Document Server

    Brekiesz, M; Maj, A; Kmiecik, M; Beck, C; Bednarczyk, P; Grebosz, J; Haas, F; Meczynski, W; Rauch, V; Rousseau, M; Zafra, A S; Styczen, J; Thummerer, S; Zieblinski, M; Zuber, K

    2004-01-01

    The 46Ti compound nucleus, as populated by the fusion-evaporation reaction 27Al + 19F at the bombarding energy of 144 MeV, has been investigated by charged particle spectroscopy using the multidetector array ICARE at the VIVITRON tandem facility of the IReS (Strasbourg). The light charged particles have been measured in coincidence with evaporation residues. The CACARIZO code, a Monte Carlo implementation of the statistical-model code CASCADE, has been used to calculate the spectral shapes of evaporated alpha-particles which are compared with the experimental spectra. This comparison indicates the possible signature of large deformations of the compound nucleus.

  9. Submerged AUV Charging Station

    Science.gov (United States)

    Jones, Jack A.; Chao, Yi; Curtin, Thomas

    2014-01-01

    Autonomous Underwater Vehicles (AUVs) are becoming increasingly important for military surveillance and mine detection. Most AUVs are battery powered and have limited lifetimes of a few days to a few weeks. This greatly limits the distance that AUVs can travel underwater. Using a series of submerged AUV charging stations, AUVs could travel a limited distance to the next charging station, recharge its batteries, and continue to the next charging station, thus traveling great distances in a relatively short time, similar to the Old West “Pony Express.” One solution is to use temperature differences at various depths in the ocean to produce electricity, which is then stored in a submerged battery. It is preferred to have the upper buoy submerged a reasonable distance below the surface, so as not to be seen from above and not to be inadvertently destroyed by storms or ocean going vessels. In a previous invention, a phase change material (PCM) is melted (expanded) at warm temperatures, for example, 15 °C, and frozen (contracted) at cooler temperatures, for example, 8 °C. Tubes containing the PCM, which could be paraffin such as pentadecane, would be inserted into a container filled with hydraulic oil. When the PCM is melted (expanded), it pushes the oil out into a container that is pressurized to about 3,000 psi (approx equals 20.7 MPa). When a valve is opened, the high-pressure oil passes through a hydraulic motor, which turns a generator and charges a battery. The low-pressure oil is finally reabsorbed into the PCM canister when the PCM tubes are frozen (contracted). Some of the electricity produced could be used to control an external bladder or a motor to the tether line, such that depth cycling is continued for a very long period of time. Alternatively, after the electricity is generated by the hydraulic motor, the exiting low-pressure oil from the hydraulic motor could be vented directly to an external bladder on the AUV, such that filling of the bladder

  10. Interaction of low-energy highly charged ions with matter

    International Nuclear Information System (INIS)

    The thesis presented herein deals with experimental studies of the interaction between highly charged ions and neutral matter at low collision energies. The energy range investigated is of great interest for the understanding of both charge exchange reactions between ions comprising the solar wind and various astrophysical gases, as well as the creation of near-surface nanostructures. Over the course of this thesis an experimental setup was constructed, capable of reducing the kinetic energy of incoming ions by two orders of magnitude and finally focussing the decelerated ion beam onto a solid or gaseous target. A coincidence method was employed for the simultaneous detection of photons emitted during the charge exchange process together with the corresponding projectile ions. In this manner, it was possible to separate reaction channels, whose superposition presumably propagated large uncertainties and systematic errors in previous measurements. This work has unveiled unexpectedly strong contributions of slow radiative decay channels and clear evidence of previously only postulated decay processes in charge exchange-induced X-ray spectra. (orig.)

  11. A digital Compton suppression spectroscopy without gamma-ray coincidence-summing loss using list-mode multispectral data acquisition

    International Nuclear Information System (INIS)

    The study demonstrates the advantages of an innovative list-mode multispectral data acquisition system that allows simultaneous creation of several different single, summed, coincident and anticoincident spectra with a single measurement. One of the consequences of list-mode data file offline processing is a reconstructed spectrum with Compton continuum suppression and without any full-energy peak efficiency deduction owing to true coincidence summing. The spectrometer is designed to read out analogue signal from preamplifier of gamma-ray detectors and to digitalize it using DGF/Pixie-4 software and card package (XIA LLC). This is realized by converting an Ortec Compton suppression data acquisition system into an all-digital spectrometer. Instead of using its timing electronic chain to determine the coincidence event, the analog signals from primary and guard detectors were connected directly into the Pixie-4 card for pulse height and time coincident measurement by individually logging and time stamping each electronic pulse. The data acquired in list-mode included coincidence and anticoincidence events consisting of records of energy and timestamp from primary and guard detectors. Every event was stored in a text file for offline processing and spectral reconstruction. A sophisticated computer simulation was also created with the goals of obtaining a better understanding of the experimental results and calculating efficiency. (author)

  12. Space charge effects of CSR

    International Nuclear Information System (INIS)

    Cooler Storage Ring (CSR), and upgrading program planned at the Heavy Ion Research Facility in Lanzhou (HIRFL), will supply beams with higher quality and intensity. Space charge effects should be considered due to this magnitude of intensity in CSR. The concept and some phenomena of space charge effects are discussed. Space charge intensity limit and space charge tune shift of normal CSR operation are given. It is of significance for the construction and operation of the future facility

  13. Banking Bank Charge Debates Continue

    Institute of Scientific and Technical Information of China (English)

    WANG PEI

    2006-01-01

    @@ The saying, "There's no such thing as a free lunch" is one that can be applied to the charges increasingly being imposed on savers by Chinese banks.Ranging from managementfees for small deposit accounts to charges for withdrawals of large amounts of cash, from ATM cross-bank withdrawal charges to annual fees for bank payment cards, charges by banks are becoming a unstoppable trend. But it is not a trend the general public is so keen to accept.

  14. Modular Battery Charge Controller

    Science.gov (United States)

    Button, Robert; Gonzalez, Marcelo

    2009-01-01

    A new approach to masterless, distributed, digital-charge control for batteries requiring charge control has been developed and implemented. This approach is required in battery chemistries that need cell-level charge control for safety and is characterized by the use of one controller per cell, resulting in redundant sensors for critical components, such as voltage, temperature, and current. The charge controllers in a given battery interact in a masterless fashion for the purpose of cell balancing, charge control, and state-of-charge estimation. This makes the battery system invariably fault-tolerant. The solution to the single-fault failure, due to the use of a single charge controller (CC), was solved by implementing one CC per cell and linking them via an isolated communication bus [e.g., controller area network (CAN)] in a masterless fashion so that the failure of one or more CCs will not impact the remaining functional CCs. Each micro-controller-based CC digitizes the cell voltage (V(sub cell)), two cell temperatures, and the voltage across the switch (V); the latter variable is used in conjunction with V(sub cell) to estimate the bypass current for a given bypass resistor. Furthermore, CC1 digitizes the battery current (I1) and battery voltage (V(sub batt) and CC5 digitizes a second battery current (I2). As a result, redundant readings are taken for temperature, battery current, and battery voltage through the summation of the individual cell voltages given that each CC knows the voltage of the other cells. For the purpose of cell balancing, each CC periodically and independently transmits its cell voltage and stores the received cell voltage of the other cells in an array. The position in the array depends on the identifier (ID) of the transmitting CC. After eight cell voltage receptions, the array is checked to see if one or more cells did not transmit. If one or more transmissions are missing, the missing cell(s) is (are) eliminated from cell

  15. Photoionization of endohedral fullerenes using soft x-ray coincidence spectroscopy

    Science.gov (United States)

    Obaid, Razib; Xiong, Hui; Ablikim, Utuq; Augustin, Sven; Schnorr, Kirsten; Battistoni, Andrea; Wolf, Thomas; Carroll, Ann Marie; Bilodeau, Rene; Osipov, Timur; Rolles, Daniel; Berrah, Nora

    2016-05-01

    Endohedral fullerenes are a model system to understand the reorganization dynamics of highly charged molecular systems with delocalized electronic clouds in the multiphoton excitation regime. Previous experiments at the Linac Coherent Light Source (LCLS) using free-electron laser (FEL) and ultrafast IR laser pulses studied this feature in Ho3N@C80. The question remains whether these dynamics can be studied in the site-specific single photo-ionization regime. Ho3N@C80 is particularly interesting since the inner molecule, Ho3N, is unstable in its natural form. The presence of the encapsulating cage, with the charge exchange characteristics of Holmium, stabilizes the whole molecule. In this study, we will present the charge fragmentation dynamics of this species in the single photoionization process of inner shell electrons (4d) of Holmium using the Advanced Light Source (ALS) at LBNL. Photoion-photoion correlation data, alongside with qualitative electron data will be presented. Funded by the DoE-BES, Grant No. DE-SC0012376.

  16. A Web-based Google-Earth Coincident Imaging Tool for Satellite Calibration and Validation

    Science.gov (United States)

    Killough, B. D.; Chander, G.; Gowda, S.

    2009-12-01

    The Group on Earth Observations (GEO) is coordinating international efforts to build a Global Earth Observation System of Systems (GEOSS) to meet the needs of its nine “Societal Benefit Areas”, of which the most demanding, in terms of accuracy, is climate. To accomplish this vision, satellite on-orbit and ground-based data calibration and validation (Cal/Val) of Earth observation measurements are critical to our scientific understanding of the Earth system. Existing tools supporting space mission Cal/Val are often developed for specific campaigns or events with little desire for broad application. This paper describes a web-based Google-Earth based tool for the calculation of coincident satellite observations with the intention to support a diverse international group of satellite missions to improve data continuity, interoperability and data fusion. The Committee on Earth Observing Satellites (CEOS), which includes 28 space agencies and 20 other national and international organizations, are currently operating and planning over 240 Earth observation satellites in the next 15 years. The technology described here will better enable the use of multiple sensors to promote increased coordination toward a GEOSS. The CEOS Systems Engineering Office (SEO) and the Working Group on Calibration and Validation (WGCV) support the development of the CEOS Visualization Environment (COVE) tool to enhance international coordination of data exchange, mission planning and Cal/Val events. The objective is to develop a simple and intuitive application tool that leverages the capabilities of Google-Earth web to display satellite sensor coverage areas and for the identification of coincident scene locations along with dynamic menus for flexibility and content display. Key features and capabilities include user-defined evaluation periods (start and end dates) and regions of interest (rectangular areas) and multi-user collaboration. Users can select two or more CEOS missions from a

  17. Measuring Charge Transport in an Amorphous Semiconductor Using Charge Sensing

    OpenAIRE

    Maclean, K; Mentzel, T. S.; Kastner, M. A.

    2009-01-01

    We measure charge transport in hydrogenated amorphous silicon (a-Si:H) using a nanometer scale silicon MOSFET as a charge sensor. This charge detection technique makes possible the measurement of extremely large resistances. At high temperatures, where the a-Si:H resistance is not too large, the charge detection measurement agrees with a direct measurement of current. The device geometry allows us to probe both the field effect and dispersive transport in the a-Si:H using charge sensing and t...

  18. Adsorption of highly charged Gaussian polyelectrolytes onto oppositely charged surfaces

    Science.gov (United States)

    Dutta, Sandipan; Jho, Y. S.

    2016-03-01

    In many biological processes highly charged biopolymers are adsorbed onto oppositely charged surfaces of macroions and membranes. They form strongly correlated structures close to the surface which cannot be explained by the conventional Poisson-Boltzmann theory. In this work strong coupling theory is used to study the adsorption of highly charged Gaussian polyelectrolytes. Two cases of adsorptions are considered, when the Gaussian polyelectrolytes are confined (a) by one charged wall, and (b) between two charged walls. The effects of salt and the geometry of the polymers on their adsorption-depletion transitions in the strong coupling regime are discussed.

  19. Fragmentation of molecules under charge-changing collisions of a few MeV heavy ions

    International Nuclear Information System (INIS)

    We investigated molecular fragmentation of CO and C2H2 molecules by impact of various fast heavy ions. Fragment ions produced in electron capture and loss collisions of projectile ions were measured in coincidence with final projectile charge states. Data acquisition using position sensitive detection system allows us to obtain 3D momentum imaging of fragment ions and kinetic energy release (KER) in various charge-changing collisions. It was found that the KER spectra show strong dependence on the type of charge-changing collisions. This may be caused by the difference of impact parameters associated with individual charge-changing collisions. Moreover we revealed the different fragmentation pathway between ion impacts and photoionization

  20. Tools for charged Higgs bosons

    Energy Technology Data Exchange (ETDEWEB)

    Staal, Oscar

    2010-12-15

    We review the status of publicly available software tools applicable to charged Higgs physics. A selection of codes are highlighted in more detail, focusing on new developments that have taken place since the previous charged Higgs workshop in 2008. We conclude that phenomenologists now have the tools ready to face the LHC data. A new web page collecting charged Higgs resources is presented. (orig.)

  1. Charging Users for Library Service.

    Science.gov (United States)

    Cooper, Michael D.

    1978-01-01

    Examines the question of instituting direct charges for library service, using on-line bibliographic searching as an example, and contrasts this with the current indirect charging system where services are paid for by taxes. Information, as a merit good, should be supplied with or without direct charges, depending upon user status. (CWM)

  2. Transient analysis of charging system with centrifugal charging pumps

    International Nuclear Information System (INIS)

    The CARD (CVCS Analysis for Design) code has been developed for the transient analysis of the letdown and charging system of Korea Standard Nuclear Power Plant. The computer code has been already verified and validated by comparing with actual test results. Analyzed in this paper are the flow and pressure transients in the charging line. The sensitivity studies are performed to select the acceptable control parameters of charging line backpressure controller and seal injection flow controller. In addition, the seal injection system transient is evaluated for the pressurizer auxiliary spray operation. It is shown that the charging line backpressure controller control parameters yield a significant effect on the charging system stability. The results obtained from this study will be used to verify the system design and to select the optimum control parameters for the charging system with centrifugal charging pumps

  3. A First Search for Coincident Gravitational Waves and High Energy Neutrinos Using LIGO, Virgo and ANTARES Data from 2007

    Science.gov (United States)

    Adrian-Martinez, S.; Samarai, Al; Albert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M; Astraatmadja, T.; Aubert, J.-J.; Baret, B.; Basa, S.; Bertin, V.; Biagi, S.; Bigongiari, C.; Bogazzi, C; Bou-Cabo, M.; Bouhou, B.; Bowhuis, M. C.; Bertin, V.; Brunner, J.; Busto, J.; Blackburn, L.; Camp, J. B.; Kanner, J. B.

    2013-01-01

    We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.

  4. A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

    CERN Document Server

    Adrián-Martínez, S; Samarai, I Al; Albert, A; André, M; Anghinolfi, M; Anton, G; Anvar, S; Ardid, M; Jesus, A C Assis; Astraatmadja, T; Aubert, J-J; Baret, B; Basa, S; Bertin, V; Biagi, S; Bigi, A; Bigongiari, C; Bogazzi, C; Bou-Cabo, M; Bouhou, B; Bouwhuis, M C; Brunner, J; Busto, J; Camarena, F; Capone, A; Cârloganu, C; Carr, J; Cecchini, S; Charif, Z; Charvis, Ph; Chiarusi, T; Circella, M; Coniglione, R; Costantini, H; Coyle, P; Curtil, C; Decowski, M P; Dekeyser, I; Deschamps, A; Distefano, C; Donzaud, C; Dornic, D; Dorosti, Q; Drouhin, D; Eberl, T; Emanuele, U; Enzenhöfer, A; Ernenwein, J-P; Escoffier, S; Fermani, P; Ferri, M; Flaminio, V; Folger, F; Fritsch, U; Fuda, J-L; Galatà, S; Gay, P; Giacomelli, G; Giordano, V; Gómez-González, J P; Graf, K; Guillard, G; Halladjian, G; Hallewell, G; van Haren, H; Hartman, J; Heijboer, A J; Hello, Y; Hernández-Rey, J J; Herold, B; Hößl, J; Hsu, C C; de Jong, M; Kadler, M; Kalekin, O; Kappes, A; Katz, U; Kavatsyuk, O; Kooijman, P; Kopper, C; Kouchner, A; Kreykenbohm, I; Kulikovskiy, V; Lahmann, R; Lamare, P; Larosa, G; Lattuada, D; Lefèvre, D; Lim, G; Presti, D Lo; Loehner, H; Loucatos, S; Mangano, S; Marcelin, M; Margiotta, A; Martínez-Mora, J A; Meli, A; Montaruli, T; Morganti, M; Moscoso, L; Motz, H; Neff, M; Nezri, E; Palioselitis, D; Păvălaş, G E; Payet, K; Payre, P; Petrovic, J; Piattelli, P; Picot-Clemente, N; Popa, V; Pradier, T; Presani, E; Racca, C; Reed, C; Richardt, C; Richter, R; Rivière, C; Robert, A; Roensch, K; Rostovtsev, A; Ruiz-Rivas, J; Rujoiu, M; Russo, G V; Salesa, F; Samtleben, D F E; Sapienza, P; Schöck, F; Schuller, J-P; Schüssler, F; Seitz, T; Shanidze, R; Simeone, F; Spies, A; Spurio, M; Steijger, J J M; Stolarczyk, Th; Sánchez-Losa, A; Taiuti, M; Tamburini, C; Toscano, S; Vallage, B; Van Elewyck, V; Vannoni, G; Vecchi, M; Vernin, P; Wagner, S; Wijnker, G; Wilms, J; de Wolf, E; Yepes, H; Zaborov, D; Zornoza, J D; Zúñiga, J; Aasi, J; Abadie, J; Abbott, B P; Abbott, R; Abbott, T D; Abernathy, M; Accadia, T; Acernese, F; Adams, C; Adams, T; Addesso, P; Adhikari, R; Affeldt, C; Agathos, M; Agatsuma, K; Ajith, P; Allen, B; Allocca, A; Ceron, E Amador; Amariutei, D; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Ast, S; Aston, S M; Astone, P; Atkinson, D; Aufmuth, P; Aulbert, C; Aylott, B E; Babak, S; Baker, P; Ballardin, G; Ballmer, S; Bao, Y; Barayoga, J C B; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Bastarrika, M; Basti, A; Batch, J; Bauchrowitz, J; Bauer, Th S; Bebronne, M; Beck, D; Behnke, B; Bejger, M; Beker, M G; Bell, A S; Bell, C; Belopolski, I; Benacquista, M; Berliner, J M; Bertolini, A; Betzwieser, J; Beveridge, N; Beyersdorf, P T; Bhadbade, T; Bilenko, I A; Billingsley, G; Birch, J; Biswas, R; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Bland, B; Blom, M; Bock, O; Bodiya, T P; Bogan, C; Bond, C; Bondarescu, R; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, S; Bosi, L; Braccini, S; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Breyer, J; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Britzger, M; Brooks, A F; Brown, D A; Bulik, T; Bulten, H J; Buonanno, A; Burguet--Castell, J; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Calloni, E; Camp, J B; Campsie, P; Cannon, K; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C; Cesarini, E; Chalermsongsak, T; Charlton, P; Chassande-Mottin, E; Chen, W; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Chow, J; Christensen, N; Chua, S S Y; Chung, C T Y; Chung, S; Ciani, G; Clara, F; Clark, D E; Clark, J A; Clayton, J H; Cleva, F; Coccia, E; Cohadon, P -F; Colacino, C N; Colla, A; Colombini, M; Conte, A; Conte, R; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corsi, A; Costa, C A; Coughlin, M; Coulon, J -P; Couvares, P; Coward, D M; Cowart, M; Coyne, D C; Creighton, J D E; Creighton, T D; Cruise, A M; Cumming, A; Cunningham, L; Cuoco, E; Cutler, R M; Dahl, K; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daudert, B; Daveloza, H; Davier, M; Daw, E J; Day, R; Dayanga, T; De Rosa, R; DeBra, D; Debreczeni, G; Degallaix, J; Del Pozzo, W; Dent, T; Dergachev, V; DeRosa, R; Dhurandhar, S; Di Fiore, L; Di Lieto, A; Di Palma, I; Emilio, M Di Paolo; Di Virgilio, A; Díaz, M; Dietz, A; Donovan, F; Dooley, K L; Doravari, S; Dorsher, S; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dumas, J -C; Dwyer, S; Eberle, T; Edgar, M; Edwards, M; Effler, A; Ehrens, P; Endrőczi, G; Engel, R; Etzel, T; Evans, K; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Farr, B F; Favata, M; Fazi, D; Fehrmann, H; Feldbaum, D; Ferrante, I; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R P; Flaminio, R; Foley, S; Forsi, E; Forte, L A; Fotopoulos, N; Fournier, J -D; Franc, J; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, M A; Frei, Z; Freise, A; Frey, R; Fricke, T T; Friedrich, D; Fritschel, P; Frolov, V V; Fujimoto, M -K; Fulda, P J; Fyffe, M; Gair, J; Galimberti, M; Gammaitoni, L; Garcia, J; Garufi, F; Gáspár, M E; Gelencser, G; Gemme, G; Genin, E; Gennai, A; Gergely, L Á; Ghosh, S; Giaime, J A; Giampanis, S; Giardina, K D; Giazotto, A; Gil-Casanova, S; Gill, C; Gleason, J; Goetz, E; González, G; Gorodetsky, M L; Goßler, S; Gouaty, R; Graef, C; Graff, P B; Granata, M; Grant, A; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Griffo, C; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C; Gupta, R; Gustafson, E K; Gustafson, R; Hallam, J M; Hammer, D; Hammond, G; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hartman, M T; Haughian, K; Hayama, K; Hayau, J -F; Heefner, J; Heidmann, A; Heintze, M C; Heitmann, H; Hello, P; Hemming, G; Hendry, M A; Heng, I S; Heptonstall, A W; Herrera, V; Heurs, M; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Holtrop, M; Hong, T; Hooper, S; Hough, J; Howell, E J; Hughey, B; Husa, S; Huttner, S H; Huynh-Dinh, T; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Izumi, K; Jacobson, M; James, E; Jang, Y J; Jaranowski, P; Jesse, E; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Kasprzack, M; Kasturi, R; Katsavounidis, E; Katzman, W; Kaufer, H; Kaufman, K; Kawabe, K; Kawamura, S; Kawazoe, F; Keitel, D; Kelley, D; Kells, W; Keppel, D G; Keresztes, Z; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, B K; Kim, C; Kim, H; Kim, K; Kim, N; Kim, Y M; King, P J; Kinzel, D L; Kissel, J S; Klimenko, S; Kline, J; Kokeyama, K; Kondrashov, V; Koranda, S; Korth, W Z; Kowalska, I; Kozak, D; Kringel, V; Krishnan, B; Królak, A; Kuehn, G; Kumar, P; Kumar, R; Kurdyumov, R; Kwee, P; Lam, P K; Landry, M; Langley, A; Lantz, B; Lastzka, N; Lawrie, C; Lazzarini, A; Roux, A Le; Leaci, P; Lee, C H; Lee, H K; Lee, H M; Leong, J R; Leonor, I; Leroy, N; Letendre, N; Lhuillier, V; Li, J; Li, T G F; Lindquist, P E; Litvine, V; Liu, Y; Liu, Z; Lockerbie, N A; Lodhia, D; Logue, J; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J; Lubinski, M; Lück, H; Lundgren, A P; Macarthur, J; Macdonald, E; Machenschalk, B; MacInnis, M; Macleod, D M; Mageswaran, M; Mailand, K; Majorana, E; Maksimovic, I; Malvezzi, V; Man, N; Mandel, I; Mandic, V; Mantovani, M; Marchesoni, F; Marion, F; Márka, S; Márka, Z; Markosyan, A; Maros, E; Marque, J; Martelli, F; Martin, I W; Martin, R M; Marx, J N; Mason, K; Masserot, A; Matichard, F; Matone, L; Matzner, R A; Mavalvala, N; Mazzolo, G; McCarthy, R; McClelland, D E; McGuire, S C; McIntyre, G; McIver, J; Meadors, G D; Mehmet, M; Meier, T; Melatos, A; Melissinos, A C; Mendell, G; Menéndez, D F; Mercer, R A; Meshkov, S; Messenger, C; Meyer, M S; Miao, H; Michel, C; Milano, L; Miller, J; Minenkov, Y; Mingarelli, C M F; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Moe, B; Mohan, M; Mohapatra, S R P; Moraru, D; Moreno, G; Morgado, N; Morgia, A; Mori, T; Morriss, S R; Mosca, S; Mossavi, K; Mours, B; Mow--Lowry, C M; Mueller, C L; Mueller, G; Mukherjee, S; Mullavey, A; Müller-Ebhardt, H; Munch, J; Murphy, D; Murray, P G; Mytidis, A; Nash, T; Naticchioni, L; Necula, V; Nelson, J; Neri, I; Newton, G; Nguyen, T; Nishizawa, A; Nitz, A; Nocera, F; Nolting, D; Normandin, M E; Nuttall, L; Ochsner, E; O'Dell, J; Oelker, E; Ogin, G H; Oh, J J; Oh, S H; Oldenberg, R G; O'Reilly, B; O'Shaughnessy, R; Osthelder, C; Ott, C D; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Page, A; Palladino, L; Palomba, C; Pan, Y; Pankow, C; Paoletti, F; Paoletti, R; Papa, M A; Parisi, M; Pasqualetti, A; Passaquieti, R; Passuello, D; Pedraza, M; Penn, S; Perreca, A; Persichetti, G; Phelps, M; Pichot, M; Pickenpack, M; Piergiovanni, F; Pierro, V; Pihlaja, M; Pinard, L; Pinto, I M; Pitkin, M; Pletsch, H J; Plissi, M V; Poggiani, R; Pöld, J; Postiglione, F; Poux, C; Prato, M; Predoi, V; Prestegard, T; Price, L R; Prijatelj, M; Principe, M; Privitera, S; Prix, R; Prodi, G A; Prokhorov, L G; Puncken, O; Punturo, M; Puppo, P; Quetschke, V; Quitzow-James, R; Raab, F J; Rabeling, D S; Rácz, I; Radkins, H; Raffai, P; Rakhmanov, M; Ramet, C; Rankins, B; Rapagnani, P; Raymond, V; Re, V; Reed, C M; Reed, T; Regimbau, T; Reid, S; Reitze, D H; Ricci, F; Riesen, R; Riles, K; Roberts, M; Robertson, N A; Robinet, F; Robinson, C; Robinson, E L; Rocchi, A; Roddy, S; Rodriguez, C; Rodruck, M; Rolland, L; Rollins, J G; Romano, J D; Romano, R; Romie, J H; Rosińska, D; Röver, C; Rowan, S; Rüdiger, A; Ruggi, P; Ryan, K; Salemi, F; Sammut, L; Sandberg, V; Sankar, S; Sannibale, V; Santamaría, L; Santiago-Prieto, I; Santostasi, G; Saracco, E; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Savage, R L; Schilling, R; Schnabel, R; Schofield, R M S; Schulz, B; Schutz, B F; Schwinberg, P; Scott, J; Scott, S M; Seifert, F; Sellers, D; Sentenac, D; Sergeev, A; Shaddock, D A; Shaltev, M; Shapiro, B; Shawhan, P; Shoemaker, D H; Sidery, T L; Siemens, X; Sigg, D; Simakov, D; Singer, A; Singer, L; Sintes, A M; Skelton, G R; Slagmolen, B J J; Slutsky, J; Smith, J R; Smith, M R; Smith, R J E; Smith-Lefebvre, N D; Somiya, K; Sorazu, B; Speirits, F C; Sperandio, L; Stefszky, M; Steinert, E; Steinlechner, J; Steinlechner, S; Steplewski, S; Stochino, A; Stone, R; Strain, K A; Strigin, S E; Stroeer, A S; Sturani, R; Stuver, A L; Summerscales, T Z; Sung, M; Susmithan, S; Sutton, P J; Swinkels, B; Szeifert, G; Tacca, M; Taffarello, L; Talukder, D; Tanner, D B; Tarabrin, S P; Taylor, R; ter Braack, A P M; Thomas, P; Thorne, K A; Thorne, K S; Thrane, E; Thüring, A; Titsler, C; Tokmakov, K V; Tomlinson, C; Toncelli, A; Tonelli, M; Torre, O; Torres, C V; Torrie, C I; Tournefier, E; Travasso, F; Traylor, G; Tse, M; Ugolini, D; Vahlbruch, H; Vajente, G; Brand, J F J van den; Broeck, C Van Den; van der Putten, S; van Veggel, A A; Vass, S; Vasuth, M; Vaulin, R; Vavoulidis, M; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Vetrano, F; Viceré, A; Villar, A E; Vinet, J -Y; Vitale, S; Vocca, H; Vorvick, C; Vyatchanin, S P; Wade, A; Wade, L; Wade, M; Waldman, S J; Wallace, L; Wan, Y; Wang, M; Wang, X; Wanner, A; Ward, R L; Was, M; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Wessels, P; West, M; Westphal, T; Wette, K; Whelan, J T; Whitcomb, S E; White, D J; Whiting, B F; Wiesner, K; Wilkinson, C; Willems, P A; Williams, L; Williams, R; Willke, B; Wimmer, M; Winkelmann, L; Winkler, W; Wipf, C C; Wiseman, A G; Wittel, H; Woan, G; Wooley, R; Worden, J; Yablon, J; Yakushin, I; Yamamoto, H; Yamamoto, K; Yancey, C C; Yang, H; Yeaton-Massey, D; Yoshida, S; Yvert, M; Zadrożny, A; Zanolin, M; Zendri, J -P; Zhang, F; Zhang, L; Zhao, C; Zotov, N; Zucker, M E; Zweizig, J

    2012-01-01

    We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.

  5. A first search for coincident gravitational waves and high energy neutrinos using LIGO, Virgo and ANTARES data from 2007

    Energy Technology Data Exchange (ETDEWEB)

    Adrián-Martínez, S.; Ardid, M.; Bou-Cabo, M. [Institut d' Investigació per a la Gestió Integrada de les Zones Costaneres (IGIC) - Universitat Politècnica de València. C/ Paranimf 1 , 46730 Gandia, Spain. (Spain); Samarai, I. Al; Aubert, J-J.; Bertin, V.; Brunner, J. [CPPM, Aix-Marseille Université, CNRS/IN2P3, Marseille (France); Albert, A. [GRPHE - Institut universitaire de technologie de Colmar, 34 rue du Grillenbreit BP 50568 - 68008 Colmar (France); André, M. [Technical University of Catalonia, Laboratory of Applied Bioacoustics, Rambla Exposició, 08800 Vilanova i la Geltrú, Barcelona (Spain); Anghinolfi, M. [INFN - Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Anton, G. [Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Anvar, S. [Direction des Sciences de la Matière - Institut de recherche sur les lois fondamentales de l' Univers - Service d' Electronique des Détecteurs et d' Informatique, CEA Saclay, 91191 Gif-sur-Yvette Cedex (France); Astraatmadja, T.; Bogazzi, C.; Bouwhuis, M.C. [Nikhef, Science Park, Amsterdam (Netherlands); Baret, B.; Bouhou, B. [APC, Université Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cité, 75205 Paris (France); Basa, S. [LAM - Laboratoire d' Astrophysique de Marseille, Pôle de l' Étoile Site de Château-Gombert, rue Frédéric Joliot-Curie 38, 13388 Marseille Cedex 13 (France); Biagi, S. [INFN - Sezione di Bologna, Viale C. Berti-Pichat 6/2, 40127 Bologna (Italy); Bigongiari, C., E-mail: antares.spokesperson@in2p3.fr, E-mail: lsc-spokesperson@ligo.org, E-mail: virgo-spokesperson@ego-gw.it, E-mail: Irene.DiPalma@aei.mpg.de, E-mail: thierry.pradier@iphc.cnrs.fr [IFIC - Instituto de Física Corpuscular, Edificios Investigación de Paterna, CSIC - Universitat de València, Apdo. de Correos 22085, 46071 Valencia (Spain); and others

    2013-06-01

    We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.

  6. A first search for coincident gravitational waves and high energy neutrinos using LIGO, Virgo and ANTARES data from 2007

    International Nuclear Information System (INIS)

    We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events

  7. Search for transient gravitational waves in coincidence with short-duration radio transients during 2007-2013

    Science.gov (United States)

    Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Behnke, B.; Bejger, M.; Bell, A. S.; Bell, C. J.; Berger, B. K.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birney, R.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bojtos, P.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerboni Baiardi, L.; Cerretani, G.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, H. Y.; Chen, Y.; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C. G.; Cominsky, L.; Constancio, M.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dattilo, V.; Dave, I.; Daveloza, H. P.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dojcinoski, G.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gaur, G.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.

    2016-06-01

    We present an archival search for transient gravitational-wave bursts in coincidence with 27 single-pulse triggers from Green Bank Telescope pulsar surveys, using the LIGO, Virgo, and GEO interferometer network. We also discuss a check for gravitational-wave signals in coincidence with Parkes fast radio bursts using similar methods. Data analyzed in these searches were collected between 2007 and 2013. Possible sources of emission of both short-duration radio signals and transient gravitational-wave emission include starquakes on neutron stars, binary coalescence of neutron stars, and cosmic string cusps. While no evidence for gravitational-wave emission in coincidence with these radio transients was found, the current analysis serves as a prototype for similar future searches using more sensitive second-generation interferometers.

  8. Explaining the Dark Energy, Baryon and Dark Matter Coincidence via Domain-Dependent Random Densities

    CERN Document Server

    McDonald, John

    2013-01-01

    The dark energy, dark matter and baryon densities in the Universe are observed to be similar, with a factor of no more than 20 between the largest and smallest densities. We show that this coincidence can be understood via superhorizon domains of randomly varying densities when the baryon density at initial collapse of galaxy-forming perturbations is determined by anthropic selection. The baryon and dark matter densities are assumed to be dependent on random variables \\theta_{d} and \\theta_{b} according to \\rho_{dm} ~ \\theta_{d}^{\\alpha} and \\rho_{b} ~ \\theta_{b}^{\\beta}, while the effectively constant dark energy density is dependent upon a random variable \\phi_{Q} according to \\rho_{Q} ~ \\phi_{Q}^{n}. The ratio of the baryon density to the dark energy density at initial collapse, r_{Q}, and the baryon-to-dark matter ratio, r, are then determined purely statistically, with no dependence on the anthropically-preferred baryon density. We compute the probability distribution for r_{Q} and r and show that the ob...

  9. Coincident helminth infection modulates systemic inflammation and immune activation in active pulmonary tuberculosis.

    Directory of Open Access Journals (Sweden)

    Parakkal Jovvian George

    Full Text Available Helminth infections are known to modulate innate and adaptive immune responses in active and latent tuberculosis (TB. However, the role of helminth infections in modulating responses associated with inflammation and immune activation (reflecting disease activity and/or severity in TB is not known.We measured markers of inflammation and immune activation in active pulmonary TB individuals (ATB with co-incidental Strongyloides stercoralis (Ss infection. These included systemic levels of acute phase proteins, matrix metalloproteinases and their endogenous inhibitors and immune activation markers. As a control, we measured the systemic levels of the same molecules in TB-uninfected individuals (NTB with or without Ss infection.Our data confirm that ATB is associated with elevated levels of the various measured molecules when compared to those seen in NTB. Our data also reveal that co-incident Ss infection in ATB individuals is associated with significantly decreased circulating levels of acute phase proteins, matrix metalloproteinases, tissue inhibitors of matrix metalloproteinases as well as the systemic immune activation markers, sCD14 and sCD163. These changes are specific to ATB since they are absent in NTB individuals with Ss infection.Our data therefore reveal a profound effect of Ss infection on the markers associated with TB disease activity and severity and indicate that co-incidental helminth infections might dampen the severity of TB disease.

  10. Low-SWaP coincidence processing for Geiger-mode LIDAR video

    Science.gov (United States)

    Schultz, Steven E.; Cervino, Noel P.; Kurtz, Zachary D.; Brown, Myron Z.

    2015-05-01

    Photon-counting Geiger-mode lidar detector arrays provide a promising approach for producing three-dimensional (3D) video at full motion video (FMV) data rates, resolution, and image size from long ranges. However, coincidence processing required to filter raw photon counts is computationally expensive, generally requiring significant size, weight, and power (SWaP) and also time. In this paper, we describe a laboratory test-bed developed to assess the feasibility of low-SWaP, real-time processing for 3D FMV based on Geiger-mode lidar. First, we examine a design based on field programmable gate arrays (FPGA) and demonstrate proof-of-concept results. Then we examine a design based on a first-of-its-kind embedded graphical processing unit (GPU) and compare performance with the FPGA. Results indicate feasibility of real-time Geiger-mode lidar processing for 3D FMV and also suggest utility for real-time onboard processing for mapping lidar systems.

  11. Putting beta-diversity on the map: broad-scale congruence and coincidence in the extremes.

    Directory of Open Access Journals (Sweden)

    Meghan W McKnight

    2007-10-01

    Full Text Available Beta-diversity, the change in species composition between places, is a critical but poorly understood component of biological diversity. Patterns of beta-diversity provide information central to many ecological and evolutionary questions, as well as to conservation planning. Yet beta-diversity is rarely studied across large extents, and the degree of similarity of patterns among taxa at such scales remains untested. To our knowledge, this is the first broad-scale analysis of cross-taxon congruence in beta-diversity, and introduces a new method to map beta-diversity continuously across regions. Congruence between amphibian, bird, and mammal beta-diversity in the Western Hemisphere varies with both geographic location and spatial extent. We demonstrate that areas of high beta-diversity for the three taxa largely coincide, but areas of low beta-diversity exhibit little overlap. These findings suggest that similar processes lead to high levels of differentiation in amphibian, bird, and mammal assemblages, while the ecological and biogeographic factors influencing homogeneity in vertebrate assemblages vary. Knowledge of beta-diversity congruence can help formulate hypotheses about the mechanisms governing regional diversity patterns and should inform conservation, especially as threat from global climate change increases.

  12. Radar Coincidence Imaging for Off-Grid Target Using Frequency-Hopping Waveforms

    Directory of Open Access Journals (Sweden)

    Xiaoli Zhou

    2016-01-01

    Full Text Available Radar coincidence imaging (RCI is a high-resolution staring imaging technique without the limitation of the target relative motion. To achieve better imaging performance, sparse reconstruction is commonly used. While its performance is based on the assumption that the scatterers are located at the prediscretized grid-cell centers, otherwise, off-grid emerges and the performance of RCI degrades significantly. In this paper, RCI using frequency-hopping (FH waveforms is considered. The off-grid effects are analyzed, and the corresponding constrained Cramér-Rao bound (CCRB is derived based on the mean square error (MSE of the “oracle” estimator. For off-grid RCI, the process is composed of two stages: grid matching and off-grid error (OGE calibration, where two-dimension (2D band-excluded locally optimized orthogonal matching pursuit (BLOOMP and alternating iteration minimization (AIM algorithms are proposed, respectively. Unlike traditional sparse recovery methods, BLOOMP realizes the recovery in the refinement grids by overwhelming the shortages of coherent dictionary and is robust to noise and OGE. AIM calibration algorithm adaptively adjusts the OGE and, meanwhile, seeks the optimal target reconstruction result.

  13. Sensitive neutron detection method using delayed coincidence transitions in existing iodine-containing detectors

    CERN Document Server

    Yakushev, E; Drokhlyansky, A; Filosofov, D; Kalaninova, Z; Timkin, V; Ponomarev, D

    2016-01-01

    This letter explains a new, highly sensitive method for the detection of neutrons, which uses the T$_{1/2}=845$ ns delay in the decay of $^{128}$I at the 137.8 keV energy level, resulting from the capture of thermal neutrons by iodine nuclei in NaI and CsI scintillation detectors. The use of delayed coincidence techniques with a several $\\mu {\\rm s}$ time frame for delayed events allows for the highly effective discrimination of neutron events from any existing background signals. A comparison of ambient neutron measurements between those identified through the suggested method from a cylindrical, \\o$\\, 63 \\, {\\rm mm}\\times 63\\, {\\rm mm}$ NaI(Tl) scintillator and those from a low-background proportional $^3$He counter experimentally demonstrates the efficacy of this neutron detection method. For an isotropic, $4\\pi$, thermal neutron flux of 1 ${\\rm n}\\, {\\rm cm}^{-2}\\, {\\rm s}^{-1}$, the absolute sensitivity of the NaI detector was found to be $6.5 \\pm 1\\, {\\rm counts}\\, {\\rm s}^{-1}$ with a background of $0....

  14. Co-incident insertion enables high efficiency genome engineering in mouse embryonic stem cells

    Science.gov (United States)

    Shy, Brian R.; MacDougall, Matthew S.; Clarke, Ryan; Merrill, Bradley J.

    2016-01-01

    CRISPR/Cas9 nucleases have enabled powerful, new genome editing capabilities; however, the preponderance of non-homologous end joining (NHEJ) mediated repair events over homology directed repair (HDR) in most cell types limits the ability to engineer precise changes in mammalian genomes. Here, we increase the efficiency of isolating precise HDR-mediated events in mouse embryonic stem (ES) cells by more than 20-fold through the use of co-incidental insertion (COIN) of independent donor DNA sequences. Analysis of on:off-target frequencies at the Lef1 gene revealed that bi-allelic insertion of a PGK-Neo cassette occurred more frequently than expected. Using various selection cassettes targeting multiple loci, we show that the insertion of a selectable marker at one control site frequently coincided with an insertion at an unlinked, independently targeted site, suggesting enrichment of a sub-population of HDR-proficient cells. When individual cell events were tracked using flow cytometry and fluorescent protein markers, individual cells frequently performed either a homology-dependent insertion event or a homology-independent event, but rarely both types of insertions in a single cell. Thus, when HDR-dependent selection donors are used, COIN enriches for HDR-proficient cells among heterogeneous cell populations. When combined with a self-excising selection cassette, COIN provides highly efficient and scarless genome editing. PMID:27484482

  15. Assessment of the co-incidence between non alcoholic fatty liver disease and carotid atherosclerosis.

    Science.gov (United States)

    El-Sayed, Sohair Abd El-Kader; El-Folly, Runia Fouad; Ahmed, Amr Mahmmoud

    2014-04-01

    Non-alcoholic fatty liver disease (NAFLD) is currently the most common cause of abnormal liver biochemistry and cryptogenic cirrhosis. Those with NAFLD have a higher prevalence of atherosclerosis, as shown by increased carotid artery intimal media thickness (CIMT). The aim of this study is to assess the co-incidence and prevalence between NAFLD and carotid atherosclerosis. In this study seventy-two subjects were categorized into 2 groups. GI: 52 patients diagnosed as NAFLD with diabetes mellitus type 2 or obesity or hyperlipedemia. GII: 20 diseased controls diagnosed as NAFLD without other predisposing factor. CIMT and plaque prevalence were estimated by carotid ultrasonography as a single trained operator who was blind to clinical characteristics of participants. The results showed that CIMT by carotid duplex ultrasonography was significantly higher in group A than group B but CIMT did not reveal any significant difference as regards to the etiology of NAFLD. CIMT was significantly higher in cases with bright liver than those with homogenous liver (by abdominal US) in group I and II. CIMT was significantly higher in those with moderate steatosis than those with mild steatosis (in GI & GII).

  16. Purifying selection shapes the coincident SNP distribution of primate coding sequences

    Science.gov (United States)

    Chen, Chia-Ying; Hung, Li-Yuan; Wu, Chan-Shuo; Chuang, Trees-Juen

    2016-01-01

    Genome-wide analysis has observed an excess of coincident single nucleotide polymorphisms (coSNPs) at human-chimpanzee orthologous positions, and suggested that this is due to cryptic variation in the mutation rate. While this phenomenon primarily corresponds with non-coding coSNPs, the situation in coding sequences remains unclear. Here we calculate the observed-to-expected ratio of coSNPs (coSNPO/E) to estimate the prevalence of human-chimpanzee coSNPs, and show that the excess of coSNPs is also present in coding regions. Intriguingly, coSNPO/E is much higher at zero-fold than at nonzero-fold degenerate sites; such a difference is due to an elevation of coSNPO/E at zero-fold degenerate sites, rather than a reduction at nonzero-fold degenerate ones. These trends are independent of chimpanzee subpopulation, population size, or sequencing techniques; and hold in broad generality across primates. We find that this discrepancy cannot fully explained by sequence contexts, shared ancestral polymorphisms, SNP density, and recombination rate, and that coSNPO/E in coding sequences is significantly influenced by purifying selection. We also show that selection and mutation rate affect coSNPO/E independently, and coSNPs tend to be less damaging and more correlated with human diseases than non-coSNPs. These suggest that coSNPs may represent a “signature” during primate protein evolution. PMID:27255481

  17. A huge 6.2 kilogram uterine myoma coinciding with omental leiomyosarcoma: case report.

    Science.gov (United States)

    Ruan, C W; Lee, C L; Yen, C F; Wang, C J; Soong, Y K

    1999-12-01

    Surgery for massive abdominal tumors is both interesting and challenging. We present a case involving a multiple uterine myoma weighing 6.2 Kg which coincided with omental leiomyosarcoma. To our knowledge, this is the first report of this type of condition in the English literature. A 44-year-old nulliparous woman had suffered from abdominal pain for a long time. A huge abdominal mass was palpated on physical examination. Computed tomography scanning revealed a huge pelvic-abdominal mass with the possibility of small bowel loops invaded by the mass. A 6-cm omental mass was incidentally found during the subsequent hysterectomy procedure. Perforation of the urinary bladder occurred during the dissection of adhesion. Resection of the omental mass, wide wedge resection of the invaded small bowel, primary repair of the bladder, and hysterectomy were performed. The final pathologic diagnosis was uterine leiomyomata with omental leiomyosarcoma. The patient returned home on postoperative day 14 and was well at the 18-month follow-up examination. The challenge of these tumors lies in their proper diagnosis and surgical management. More case reports and follow-up studies are needed to confirm the efficacy of their management.

  18. Coincidence FDG-PET in the evaluation of Langerhans' cell histiocytosis: preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

    Binkovitz, Larry A.; Adler, Brent H. [Department of Radiology, Columbus Children' s Hospital, OH (United States); Olshefski, Randal S. [Department of Hematology and Oncology, Columbus Children' s Hospital, OH (United States)

    2003-09-01

    Bone involvement in Langerhans' cell histiocytosis (LCH) is common. Both bone scintigraphy and plain films are used to identify osseous lesions, but lack specificity for disease activity and response to therapy. FDG-PET is a sensitive technique for identifying bone lesions when histiocytes are present. To describe the potential of coincidence FDG-PET (cFDG-PET) for identification of active bone lesions in LCH and to determine whether it can provide more specific information regarding lesional response to therapy than bone scintigraphy or radiography. The clinical data and imaging findings of three patients with osseous lesions of LCH were retrospectively reviewed. cFDG-PET identified all active LCH osseous lesions in these patients, differentiated active from healed lesions, and demonstrated normalization of uptake in a treated lesion earlier than bone scintigraphy and radiography. cFDG-PET appears to have greater specificity than bone scintigraphy and radiography for the identification of active osseous lesions in LCH. It also may predict response to treatment earlier than conventional techniques. Its use in the evaluation of LCH warrants further study. (orig.)

  19. Coincidence of Varicella-Zoster Virus Anterior Uveitis in a Patient with Chandler's Syndrome

    Directory of Open Access Journals (Sweden)

    Takeshi Joko

    2013-11-01

    Full Text Available Purpose: We report a patient who, based on the clinical manifestations, was originally diagnosed as having Chandler's syndrome and later developed varicella-zoster virus (VZV DNA-positive anterior uveitis. Methods: The patient with Chandler's syndrome who manifested anterior uveitis underwent a complete ophthalmologic examination. Polymerase chain reaction (PCR was used to amplify the viral DNA in the aqueous humor to determine the cause of the intraocular inflammation. Results: Slit-lamp biomicroscopy showed focal iris atrophy and peripheral anterior synechiae (PAS; specular microscopy of the corneal endothelium disclosed the hammered-silver appearance. Based on these clinical findings, we diagnosed this patient as having Chandler's syndrome. During the follow-up period, however, the inflammatory cells suddenly appeared in the anterior chamber with formation of keratic precipitates and an increased intraocular pressure (IOP. VZV DNA was displayed in the aqueous humor by PCR. Based upon the diagnosis of VZV anterior uveitis, corticosteroids and acyclovir were given topically and systemically. The inflammation subsided with these medications; however, trabeculectomy was finally needed to control the IOP due to PAS progression. Conclusion: The coincidence of VZV anterior uveitis with Chandler's syndrome may constitute an implication for the possible viral etiology of iridocorneal endothelial syndrome.

  20. Discovery of a VHE gamma-ray source coincident with the supernova remnant CTB 37A

    CERN Document Server

    Aharonian, F; Barresde Almeida, U; Bazer-Bachi, A R; Behera, B; Beilicke, M; Benbow, W; Bernlöhr, K; Boisson, C; Borrel, V; Braun, I; Brion, E; Brucker, J; Buhler, R; Bulik, T; Büsching, I; Boutelier, T; Carrigan, S; Chadwick, P M; Chaves, R; Chounet, L M; Clapson, A C; Coignet, G; Cornils, R; Costamante, L; Dalton, M; Degrange, B; Dickinson, H J; Djannati-Ata, A; Domainko, W; O'Connor-Drury, L; Dubois, F; Dubus, G; Dyks, J; Egberts, K; Emmanoulopoulos, D; Espigat, P; Farnier, C; Feinstein, F; Fiasson, A; Förster, A; Fontaine, G; Funk, S; Fuling, M; Gabici, S; Gallant, Y A; Giebels, B; Glicenstein, J F; Glück, B; Goret, P; Hadjichristidis, C; Hauser, D; Hauser, M; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Holleran, M; Hoppe, S; Horns, D; Jacholkowska, A; De Jager, O C; Jung, I; Katarzynski, K; Kaufmann, S; Kendziorra, E; Kerschhaggl, M; Khangulyan, D; Khelifi, B; Keogh, D; Komin, Nu; Kosack, K; Lamanna, G; Latham, I J; Lemoine-Goumard, M; Lenain, J P; Lohse, T; Martin, J M; Martineau-Huynh, O; Marcowith, A; Masterson, C; Maurin, D; McComb, T J L; Moderski, R; Moulin, E; Nakajima, H; Naumann-Godo, M; De Naurois, Mathieu; Nedbal, D; Nekrassov, D; Nolan, S J; Ohm, S; Olive, J P; de Ona Wilhelmi, E; Orford, K J; Osborne, J L; Ostrowski, M; Panter, M; Pedaletti, G; Pelletier, G; Petrucci, P O; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, Andreas G; Raubenheimer, B C; Raue, M; Rayner, S M; Reimer, O; Renaud, M; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Ruppel, J; Sahakian, V V; Santangelo, A; Schlickeiser, R; Schock, F M; Schroder, R; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Skilton, J L; Sol, H; Spangler, D; Stawarz, L; Steenkamp, R; Stegmann, C; Superina, G; Tam, P H; Tavernet, J P; Terrier, R; Tibolla, O; Van Eldik, C; Vasileiadis, G; Venter, C; Vialle, J P; Vincent, P; Vivier, M; Völk, H J; Volpe, F; Wagner, S J; Ward, M; Zdziarski, A A; Zech, A

    2008-01-01

    The supernova remnant (SNR) complex CTB 37 is an interesting candidate for observations with Very High Energy (VHE) gamma-ray telescopes such as H.E.S.S. In this region, three SNRs are seen. One of them is potentially associated with several molecular clouds, a circumstance that can be used to probe the acceleration of hadronic cosmic rays. This region was observed with the H.E.S.S. Cherenkov telescopes and the data were analyzed with standard H.E.S.S. procedures. Recent X-ray observations with Chandra and XMM-Newton were used to search for X-ray counterparts. The discovery of a new VHE gamma-ray source HESS J1714-385 coincident with the remnant CTB 37A is reported. The energy spectrum is well described by a power-law with a photon index of Gamma =2.30pm0.13 and a differential flux at 1 TeV of Phi_0 = (8.7 pm 1.0_{stat} pm 1.8_{sys})x10^{-13}cm^{-2}s^{-1}TeV^{-1}. The integrated flux above 1 TeV is equivalent to 3% of the flux of the Crab nebula above the same energy. This VHE gamma-ray source is a counterpar...

  1. An algorithm for identifying symmetric variables in the canonical OR-coincidence algebra system

    Institute of Scientific and Technical Information of China (English)

    Xiao-hua LI; Ji-zhong SHEN

    2014-01-01

    To simplify the process for identifying 12 types of symmetric variables in the canonical OR-coincidence (COC) algebra system, we propose a new symmetry detection algorithm based on OR-NXOR expansion. By analyzing the relationships between the coefficient matrices of sub-functions and the order coefficient subset matrices based on OR-NXOR expansion around two arbitrary logical variables, the constraint conditions of the order coefficient subset matrices are revealed for 12 types of symmetric variables. Based on the proposed constraints, the algorithm is realized by judging the order characteristic square value matrices. The proposed method avoids the transformation process from OR-NXOR expansion to AND-OR-NOT expansion, or to AND-XOR expansion, and solves the problem of completeness in the dj-map method. The application results show that, compared with traditional methods, the new algorithm is an optimal detection method in terms of applicability of the number of logical variables, detection type, and complexity of the identification process. The algorithm has been implemented in C language and tested on MCNC91 benchmarks. Experimental results show that the proposed algorithm is convenient and efficient.

  2. Spectroscopy of {sup 189,187}Pb from gamma-FMA coincidences

    Energy Technology Data Exchange (ETDEWEB)

    Janssens, R.V.F.; Davids, C.N.; Blumenthal, D. [and others

    1995-08-01

    The very neutron-deficient Pb isotopes are of much current interest because they exhibit shape coexistence between a spherical groundstate and a deformed prolate excited configuration located very low in excitation energy. Last year the nucleus {sup 186}Pb was studied at the FMA in an FMA-{gamma}-{gamma} coincidence experiment. The purpose of the present measurement was to delineate, for the first time, the groundstate and near groundstate excitations in the odd Pb isotopes {sup 189,187}Pb in order to identify the orbitals which have an important role in driving the nuclear shape. The experiment was performed only very recently at the FMA with 10 Compton-suppressed Ge detectors from the Argonne Notre Dame BGO Gamma-Ray facility. {sup 187}Pb was studied with the {sup 155}Gd({sup 36}Ar,4n) reaction at 179 MeV, while {sup 189}Pb was reached with the {sup 158}Gd({sup 36}Ar,5n) reaction at the same beam energy. The analysis just began. It can already be stated that transitions in both Pb isotopes were identified and that it should be possible to establish level schemes. The presence of possible isomeric states in {sup 189}Pb will be checked in a follow-up experiment planned in Canberra. A similar measurement on {sup 187}Pb appears very difficult because of the very small cross section involved.

  3. Instruction in learning a temporal pattern on an anticipation-coincidence task.

    Science.gov (United States)

    Albinet, C; Fezzani, K

    2003-08-01

    Using a computer-simulated anticipation-coincidence task, the main aim of the study was to examine the effect of the type of instruction on learning a temporal pattern. For this task, participants must learn to anticipate the appropriate time to launch a projectile to hit a moving target. The experiment involved three instructional conditions. In the Explicit-rule Discover Instruction Condition participants were informed that target speed could change from trial to trial and that change is controlled by a regular pattern. Their task was then to search, to identify, and to use such pattern to enhance their anticipation. In the Explicit-Informative Instruction Condition, participants were, however, allowed before practice to examine attentively the regular pattern. Participants were also explicitly urged to use the pattern they observed to ensure a better interception of the target. Finally, in the Implicit Instruction Condition, participants were only informed that their task was to hit, or at least, to place the projectile as near as possible to the target. No additional information was provied about the target's behaviour. Analysis indicated that learning the temporal pattern was more important in Implicit than in Explicit-rule Discover Instruction Condion. However, the Explicit-Informative Instruction Condition produced unambiguouslly the highest learning. Overall, the study highlights the role of information over guidance in the understanding of the effect of the instructions on learning. Finally, we discussed the implications of these results on the comprehension of the variability of the effects of the instruction on learning.

  4. Coincident In Vitro Analysis of DNA-PK-Dependent and -Independent Nonhomologous End Joining

    Directory of Open Access Journals (Sweden)

    Cynthia L. Hendrickson

    2010-01-01

    Full Text Available In mammalian cells, DNA double-strand breaks (DSBs are primarily repaired by nonhomologous end joining (NHEJ. The current model suggests that the Ku 70/80 heterodimer binds to DSB ends and recruits DNA-PKcs to form the active DNA-dependent protein kinase, DNA-PK. Subsequently, XRCC4, DNA ligase IV, XLF and most likely, other unidentified components participate in the final DSB ligation step. Therefore, DNA-PK plays a key role in NHEJ due to its structural and regulatory functions that mediate DSB end joining. However, recent studies show that additional DNA-PK-independent NHEJ pathways also exist. Unfortunately, the presence of DNA-PKcs appears to inhibit DNA-PK-independent NHEJ, and in vitro analysis of DNA-PK-independent NHEJ in the presence of the DNA-PKcs protein remains problematic. We have developed an in vitro assay that is preferentially active for DNA-PK-independent DSB repair based solely on its reaction conditions, facilitating coincident differential biochemical analysis of the two pathways. The results indicate the biochemically distinct nature of the end-joining mechanisms represented by the DNA-PK-dependent and -independent NHEJ assays as well as functional differences between the two pathways.

  5. Coincidence FDG-PET in the evaluation of Langerhans' cell histiocytosis: preliminary findings

    International Nuclear Information System (INIS)

    Bone involvement in Langerhans' cell histiocytosis (LCH) is common. Both bone scintigraphy and plain films are used to identify osseous lesions, but lack specificity for disease activity and response to therapy. FDG-PET is a sensitive technique for identifying bone lesions when histiocytes are present. To describe the potential of coincidence FDG-PET (cFDG-PET) for identification of active bone lesions in LCH and to determine whether it can provide more specific information regarding lesional response to therapy than bone scintigraphy or radiography. The clinical data and imaging findings of three patients with osseous lesions of LCH were retrospectively reviewed. cFDG-PET identified all active LCH osseous lesions in these patients, differentiated active from healed lesions, and demonstrated normalization of uptake in a treated lesion earlier than bone scintigraphy and radiography. cFDG-PET appears to have greater specificity than bone scintigraphy and radiography for the identification of active osseous lesions in LCH. It also may predict response to treatment earlier than conventional techniques. Its use in the evaluation of LCH warrants further study. (orig.)

  6. First satellite measurements of chemical changes in coincidence with sprite activity

    Science.gov (United States)

    Arnone, Enrico; São Sabbas, Fernanda; Kero, Antti; Soula, Serge; Carlotti, Massimo; Chanrion, Olivier; Dinelli, Bianca Maria; Papandrea, Enzo; Castelli, Elisa; Neubert, Torsten

    2010-05-01

    The last twenty years have seen the discovery of electric discharges in the Earth's atmosphere above thunderstorms, the so-called sprites and jets. It has been suggested that they impact the atmospheric chemistry and possibly affect the ozone layer through their repeated occurrence. Whereas theoretical studies and laboratory experiments suggest enhancement of such gasses as nitrogen oxides by up to hundreds of percent within sprites, a definitive detection of their chemical effects have to date been unsuccessful. In this paper, we report on the first measurements of atmospheric chemical perturbations recorded in coincidence with sprite activity. A striking event occurred on 25 August 2003 when the MIPAS spectrometer onboard the Envisat satellite recorded spectroscopic measurements soon after a sequence of 11 sprites observed above Corsica (France) by Eurosprite ground facilities (details of the convective system are discussed in a companion paper by São Sabbas et al.). The measurements show an enhancement of ambient nitrous oxide by 80% at 52 km altitude in the region above the parent thunderstorm. The recorded chemical changes imply sprites can exert significant modification of the atmospheric chemistry at a regional scale, confirming model and laboratory predictions of sprite-chemistry, and requiring a new estimate of their global impact. The results of the analysis and their implications are discussed.

  7. A Rapid Coordinate Transformation Method Applied in Industrial Robot Calibration Based on Characteristic Line Coincidence

    Directory of Open Access Journals (Sweden)

    Bailing Liu

    2016-02-01

    Full Text Available Coordinate transformation plays an indispensable role in industrial measurements, including photogrammetry, geodesy, laser 3-D measurement and robotics. The widely applied methods of coordinate transformation are generally based on solving the equations of point clouds. Despite the high accuracy, this might result in no solution due to the use of ill conditioned matrices. In this paper, a novel coordinate transformation method is proposed, not based on the equation solution but based on the geometric transformation. We construct characteristic lines to represent the coordinate systems. According to the space geometry relation, the characteristic line scan is made to coincide by a series of rotations and translations. The transformation matrix can be obtained using matrix transformation theory. Experiments are designed to compare the proposed method with other methods. The results show that the proposed method has the same high accuracy, but the operation is more convenient and flexible. A multi-sensor combined measurement system is also presented to improve the position accuracy of a robot with the calibration of the robot kinematic parameters. Experimental verification shows that the position accuracy of robot manipulator is improved by 45.8% with the proposed method and robot calibration.

  8. A Rapid Coordinate Transformation Method Applied in Industrial Robot Calibration Based on Characteristic Line Coincidence.

    Science.gov (United States)

    Liu, Bailing; Zhang, Fumin; Qu, Xinghua; Shi, Xiaojia

    2016-01-01

    Coordinate transformation plays an indispensable role in industrial measurements, including photogrammetry, geodesy, laser 3-D measurement and robotics. The widely applied methods of coordinate transformation are generally based on solving the equations of point clouds. Despite the high accuracy, this might result in no solution due to the use of ill conditioned matrices. In this paper, a novel coordinate transformation method is proposed, not based on the equation solution but based on the geometric transformation. We construct characteristic lines to represent the coordinate systems. According to the space geometry relation, the characteristic line scan is made to coincide by a series of rotations and translations. The transformation matrix can be obtained using matrix transformation theory. Experiments are designed to compare the proposed method with other methods. The results show that the proposed method has the same high accuracy, but the operation is more convenient and flexible. A multi-sensor combined measurement system is also presented to improve the position accuracy of a robot with the calibration of the robot kinematic parameters. Experimental verification shows that the position accuracy of robot manipulator is improved by 45.8% with the proposed method and robot calibration. PMID:26901203

  9. Modular data acquisition system based on transputer technology for bi-dimensional time coincidence counting

    International Nuclear Information System (INIS)

    We describe the rationale and the test of a modular Data AcQuisition system (DAQ) for bi-dimensional (X-Y) digital imaging, based on a 16 channel Time-to-Digital Converter (TDC) NIM module connected to a specially designed TRAnsputer Module (TRAM). TDC time resolution is 12.5 ns (LSB) with a 40 MHz clock, time range is 3.3 s (28 bits), for a maximum rate of 500 kHz/channel guaranteed. The TDC+TRAM pair is the basic unit that can be scaled in modules of 8X+8Y channels to meet the user's requirement for a larger number of X-Y channels to be considered simultaneously. TDC directly accesses the large RAM memory (32 Mbytes) of the INMOS T805 (20 MHz) transputer on the TRAM board. Each transputer in the modular system is a node of a ring network, whose root transputer node is hosted in a i386-based personal computer. After real-time data acquisition, a parallel reconstruction algorithm resolves time coincidences. Laboratory tests give a reconstruction time of 6.2 s for 1.28 105 events on 16 X+16 Y channels (2 TDC+2 TRAM), obtained in 1 s with a fluence of 5x104 events/mm2 (typically used in radiological imaging) on an area of 1.6x1.6 mm2. ((orig.))

  10. Flow structure from a horizontal cylinder coincident with a free surface in shallow water flow

    Directory of Open Access Journals (Sweden)

    Kahraman Ali

    2012-01-01

    Full Text Available Vortex formation from a horizontal cylinder coincident with a free surface of a shallow water flow having a depth of 25.4 [mm] was experimentally investigated using the PIV technique. Instantaneous and time-averaged flow patterns in the wake region of the cylinder were examined for three different cylinder diameter values under the fully developed turbulent boundary layer condition. Reynolds numbers were in the range of 1124£ Re£ 3374 and Froude numbers were in the range of 0.41 £ Fr £ 0.71 based on the cylinder diameter. It was found that a jet-like flow giving rise to increasing the flow entrainment between the core and wake regions depending on the cylinder diameter was formed between the lower surface of the cylinder and bottom surface of the channel. Vorticity intensity, Reynolds stress correlations and the primary recirculating bubble lengths were grown to higher values with increasing the cylinder diameter. On the other hand, in the case of the lowest level of the jet-like flow emanating from the beneath of the smallest cylinder, the variation of flow characteristics were attenuated significantly in a shorter distance. The variation of the reattachment location of the separated flow to the free-surface is a strong function of the cylinder diameter and the Froude number.

  11. A Rapid Coordinate Transformation Method Applied in Industrial Robot Calibration Based on Characteristic Line Coincidence.

    Science.gov (United States)

    Liu, Bailing; Zhang, Fumin; Qu, Xinghua; Shi, Xiaojia

    2016-02-18

    Coordinate transformation plays an indispensable role in industrial measurements, including photogrammetry, geodesy, laser 3-D measurement and robotics. The widely applied methods of coordinate transformation are generally based on solving the equations of point clouds. Despite the high accuracy, this might result in no solution due to the use of ill conditioned matrices. In this paper, a novel coordinate transformation method is proposed, not based on the equation solution but based on the geometric transformation. We construct characteristic lines to represent the coordinate systems. According to the space geometry relation, the characteristic line scan is made to coincide by a series of rotations and translations. The transformation matrix can be obtained using matrix transformation theory. Experiments are designed to compare the proposed method with other methods. The results show that the proposed method has the same high accuracy, but the operation is more convenient and flexible. A multi-sensor combined measurement system is also presented to improve the position accuracy of a robot with the calibration of the robot kinematic parameters. Experimental verification shows that the position accuracy of robot manipulator is improved by 45.8% with the proposed method and robot calibration.

  12. Transfer positive hemicontinuity and zeros, coincidences, and fixed points of maps in topological vector spaces

    Directory of Open Access Journals (Sweden)

    Włodarczyk K

    2005-01-01

    Full Text Available Let be a real Hausdorff topological vector space. In the present paper, the concepts of the transfer positive hemicontinuity and strictly transfer positive hemicontinuity of set-valued maps in are introduced (condition of strictly transfer positive hemicontinuity is stronger than that of transfer positive hemicontinuity and for maps and defined on a nonempty compact convex subset of , we describe how some ideas of K. Fan have been used to prove several new, and rather general, conditions (in which transfer positive hemicontinuity plays an important role that a single-valued map has a zero, and, at the same time, we give various characterizations of the class of those pairs and maps that possess coincidences and fixed points, respectively. Transfer positive hemicontinuity and strictly transfer positive hemicontinuity generalize the famous Fan upper demicontinuity which generalizes upper semicontinuity. Furthermore, a new type of continuity defined here essentially generalizes upper hemicontinuity (the condition of upper demicontinuity is stronger than the upper hemicontinuity. Comparison of transfer positive hemicontinuity and strictly transfer positive hemicontinuity with upper demicontinuity and upper hemicontinuity and relevant connections of the results presented in this paper with those given in earlier works are also considered. Examples and remarks show a fundamental difference between our results and the well-known ones.

  13. Unbiased estimators of coincidence and correlation in non-analogous Monte Carlo particle transport

    International Nuclear Information System (INIS)

    Highlights: • The history splitting method was developed for non-Boltzmann Monte Carlo estimators. • The method allows variance reduction for pulse-height and higher moment estimators. • It works in highly multiplicative problems but Russian roulette has to be replaced. • Estimation of higher moments allows the simulation of neutron noise measurements. • Biased sampling of fission helps the effective simulation of neutron noise methods. - Abstract: The conventional non-analogous Monte Carlo methods are optimized to preserve the mean value of the distributions. Therefore, they are not suited to non-Boltzmann problems such as the estimation of coincidences or correlations. This paper presents a general method called history splitting for the non-analogous estimation of such quantities. The basic principle of the method is that a non-analogous particle history can be interpreted as a collection of analogous histories with different weights according to the probability of their realization. Calculations with a simple Monte Carlo program for a pulse-height-type estimator prove that the method is feasible and provides unbiased estimation. Different variance reduction techniques have been tried with the method and Russian roulette turned out to be ineffective in high multiplicity systems. An alternative history control method is applied instead. Simulation results of an auto-correlation (Rossi-α) measurement show that even the reconstruction of the higher moments is possible with the history splitting method, which makes the simulation of neutron noise measurements feasible

  14. Adsorption of Phosphate on Variable Charge Soils

    Institute of Scientific and Technical Information of China (English)

    HUGUO-SONG; ZHUZU-XIANG; 等

    1992-01-01

    The study about the adsorption of phosphate on four variable charge soils and some minerals revealed that two stage adsorption appeared in the adsorption isothems of phosphate on 4 soils and there was a maximum adsorption on Al-oxide-typed surfaces between pH 3.5 to pH 5.5 as suspension pH changed from 2 to 9,but the adsorption amount of phosphate decreased continually as pH rose on Fe-oxide typed surfaces.The adsorption amount of phosphate and the maximum phosphate adsorption pH decreased in the order of yellow-red soil> lateritic red soil> red soil> paddy soil,which was coincided with the content order of amorphous Al oxide.The removement of organic matter and Fe oxide made the maximum phosphate adsorption pH rise from 4.0 to 5.0 and 4.5,respectively.The desorption curves with pH of four soils showed that phosphate desorbed least at pH 5.Generally the desorption was contrary to the adsorption with pH changing.There was a good accordance between adsorption or desorption and the concentration of Al in the suspension.The possible mechanisms of phosphate adsorption are discussed.

  15. A high-resolution, multi-parameter, β-γ coincidence, μ-γ anticoincidence system for radioxenon measurement

    International Nuclear Information System (INIS)

    A high-resolution β-γ coincidence measurement system has been developed by combining a high-purity broad energy germanium and a silicon surface barrier detector. The system is intended for calibration of reference spikes and re-measurement of CTBT samples, by detection of coincident β-γ or conversion electron and X-ray radiation of the four radioxenon isotopes 131mXe, 133mXe, 133Xe and 135Xe. The use of a high-resolution, list-mode, multi-parameter data acquisition system allows off-line setup and optimization of the (anti)coincidence. A 166mHo β-γ source has been produced and validated for energy calibration and system check. The β-γ coincidence has been further enhanced by a cosmic muon veto based on six plastic scintillation detectors. The μ-γ anticoincidence has been implemented using a 50 ns resolution real-time clock for time spectroscopy. This method has been verified by running conventional TAC-ADC (combined time-amplitude and analog-digital converter) based time spectroscopy in parallel. The whole measurement system has been characterized, by measuring various radioxenon spikes and backgrounds with and without (anti)coincidence. Peak efficiencies and minimum detectable activities (MDA) for the main radioxenon isotopes have been determined. Application of μ-γ anticoincidence reduced the MDA by about a factor of two for all four radioxenon isotopes. Complementary adoption of β-γ coincidence further reduced the MDA for the metastable isotopes by more than an order of magnitude. The MDA for 135Xe reaches about 6 mBq after 1 day of measurement. For 131mXe, 133Xe and 133mXe a MDA of about 2 mBq is obtained after one week measurement.

  16. Effects of laser pulse duration and intensity on Coulomb explosion of CO2: Signatures of charge-resonance enhanced ionization

    Science.gov (United States)

    Litvinyuk, Igor V.; Bocharova, Irina; Sanderson, Joseph; Kieffer, Jean-Claude; Légaré, François

    2009-11-01

    We studied laser-induced Coulomb explosion of CO2 by full triple-coincidence momentum resolved detection of resulting ion fragments. From the coincidence momentum data we can reconstruct molecular geometry immediately before explosion. We observe the dynamics of Coulomb explosion by comparing reconstructed CO2 geometries for different Ti:Sapphire laser pulse durations (at the same intensity) ranging from few cycles (7 fs) to 200 fs. We conclude that for longer pulse durations (>=100 fs) Coulomb explosion proceeds through the enhanced ionization mechanism taking place at the critical O-O distance of 8 a.u., similarly to well known charge-resonance enhanced ionization (CREI) in H2.

  17. Branes, Charge and Intersections

    CERN Document Server

    Marolf, D M

    2001-01-01

    This is a brief summary of lectures given at the Fourth Mexican School on Gravitation and Mathematical Physics. The lectures gave an introduction to branes in eleven-dimensional supergravity and in type IIA supergravities in ten-dimensions. Charge conservation and the role of the so-called `Chern-Simons terms' were emphasized. Known exact solutions were discussed and used to provide insight into the question `Why don't fundamental strings fall off of D-branes,' which is often asked by relativists. The following is a brief overview of the lectures with an associated guide to the literature.

  18. Isotopic Distributions of the l8N Fragmentation Products in Coincidence with Neutrons on Targets 197Au and 9Be

    Institute of Scientific and Technical Information of China (English)

    李湘庆; 江栋兴; 叶沿林; 华辉; 陈陶; 李智焕; 葛愉成; 王全进; 吴和宇; 靳根明; 段利敏; 肖志刚; 王宏伟; 李祖玉; 王素芳

    2002-01-01

    We present the experimental isotopic distributions of the 18 N projectile fragmentation products Li, Be,B and Cin coincidence with neutrons, as well as the inclusive ones on 197 Au and 9Be targets. In the framework of theabrasion-ablation model, these distributions are calculated for various nucleon density distributions of the projec-tile. The comparison with experimental isotopic distributions of the projectile-like fragments in coincidence withneutrons shows that the information on the nucleon density distribution of the 18N projectile can be extracted.

  19. Automatic classification of gammas-gamma coincidence matrices; Clasificacion automatizada de matrices de coincidencias Gamma-Gamma

    Energy Technology Data Exchange (ETDEWEB)

    Los Arcos Merino, J. M.; Gonzalez, J. A.

    1978-07-01

    The information obtained during a coincidence experiment, recorded on magnetic tape by a MULTI-8 minicomputer, is transferred to a new tape in 36 bit words, using the program LEC0M8. The classification in two dimensional matrix form is carried out off-line, on a magnetic disk file, by the program CLAFI. On finishing classification one obtains a copy of the coincidence matrix on the second magnetic tape. Both programs are written to be processed in that order with the UNIVAC 1106 computer of J.E.N. (Author) 4 refs.

  20. The neutrino velocity anomaly as an explanation of the missing observation of neutrinos in coincidence with GRB

    International Nuclear Information System (INIS)

    The search for neutrinos emitted in coincidence with Gamma-Bay Burst has been so far unsuccessfully. In this paper we show that the recent result reported by the OPERA Collaboration on an early arrival time of muon neutrinos with respect to the one computed assuming the speed of light in vacuum could explain the null search for neutrinos in coincidence with Gamma-Ray Burst. Conversely, the detection of neutrino would falsify (or severely constraint) the interpretation of the OPERA anomaly in terms of super-luminal neutrinos

  1. Charged Galileon black holes

    Science.gov (United States)

    Babichev, Eugeny; Charmousis, Christos; Hassaine, Mokhtar

    2015-05-01

    We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematically compatible with the field equations. This opens up the possibility for novel searches of hairy black holes in a far more general setting of Horndeski theory.

  2. Charged Galileon black holes

    CERN Document Server

    Babichev, Eugeny; Hassaine, Mokhtar

    2015-01-01

    We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematic...

  3. Battery charging control methods, electric vehicle charging methods, battery charging apparatuses and rechargeable battery systems

    Science.gov (United States)

    Tuffner, Francis K.; Kintner-Meyer, Michael C. W.; Hammerstrom, Donald J.; Pratt, Richard M.

    2012-05-22

    Battery charging control methods, electric vehicle charging methods, battery charging apparatuses and rechargeable battery systems. According to one aspect, a battery charging control method includes accessing information regarding a presence of at least one of a surplus and a deficiency of electrical energy upon an electrical power distribution system at a plurality of different moments in time, and using the information, controlling an adjustment of an amount of the electrical energy provided from the electrical power distribution system to a rechargeable battery to charge the rechargeable battery.

  4. Charge Breeding of Radioactive Ions

    CERN Document Server

    Wenander, F J C

    2013-01-01

    Charge breeding is a technique to increase the charge state of ions, in many cases radioactive ions. The singly charged radioactive ions, produced in an isotope separator on-line facility, and extracted with a low kinetic energy of some tens of keV, are injected into a charge breeder, where the charge state is increased to Q. The transformed ions are either directed towards a dedicated experiment requiring highly charged ions, or post-accelerated to higher beam energies. In this paper the physics processes involved in the production of highly charged ions will be introduced, and the injection and extraction beam parameters of the charge breeder defined. A description of the three main charge-breeding methods is given, namely: electron stripping in gas jet or foil; external ion injection into an electron-beam ion source/trap (EBIS/T); and external ion injection into an electron cyclotron resonance ion source (ECRIS). In addition, some preparatory devices for charge breeding and practical beam delivery aspects ...

  5. Semiconductor nanocrystals in photoconductive polymers: Charge generation and charge transport

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ying; Herron, Norman; Suna, A. [Du Pont Co., Wilmington, DE (United States)

    1996-10-01

    A new class of photoconductive polymer composites, based on semiconductor nanocrystals (clusters) and carder-transporting polymers, have been developed. These materials are interesting for their potentials in laser printing, imaging, and photorefractives. We will describe material synthesis, charge transport and charge generation mechanisms. In particular, a model of field-dependent charge generation and separation in nonpolar media (e.g. polymers) will be discussed.

  6. Adsorption of highly charged Gaussian polyelectrolytes to oppositely charged surfaces

    OpenAIRE

    Dutta, Sandipan; Jho, Y. S.

    2015-01-01

    In many biological processes highly charged biomolecules are adsorbed into oppositely charged surfaces of macroions and membranes. They form strongly correlated structures close to the surface which can not be explained by the conventional Poisson-Boltzmann theory. Many of the flexible biomolecules can be described by Gaussian polymers. In this work strong coupling theory is used to study the adsorption of highly charged Gaussian polyelectrolytes. Two cases of adsorptions are considered, when...

  7. Charge Transfer and Charge Transport on the Double Helix

    OpenAIRE

    N. P. Armitage; Briman, M.; Gruner, G.

    2003-01-01

    We present a short review of various experiments that measure charge transfer and charge transport in DNA. Some general comments are made on the possible connection between 'chemistry-style' charge transfer experiments that probe fluorescence quenching and remote oxidative damage and 'physics-style' measurements that measure transport properties as defined typically in the solid-state. We then describe measurements performed by our group on the millimeter wave response of DNA. By measuring ov...

  8. Electron irradiation effect of polyurethane using coincidence doppler-broadening spectroscopy

    International Nuclear Information System (INIS)

    Full text: To understand the electron irradiation effects on polymer, polyether-urethane (ETPU) samples of 2mm in thickness and 10mm in diameter were irradiated by a 1.8MeV electron beam with beam current of 3 ma at room temperature. The irradiated doses are 5 kGy, 10 kGy, 15 kGy, 30 kGy, 100 kGy and 150 kGy. ETPU was manufactured by mixing PTMG-100, TDI-100 and MOCA. The momentum density distributions (MMDs) of electrons taking part in the annihilation processes of positron-electron pairs in ETPU have been measured by coincidence Doppler-broadening spectroscopy (CDBS). By presenting the ratio of the counts in every channel of the measured CDB spectrum to the corresponding counts from a reference spectrum (pristine ETPU), we observed that the change in MMDs is not significant for doses lower than 10 kGy. However, high momentum part of MMDs exhibit an obvious decrease for dose exceeding 15 kGy and then slowly down to steady with doses until 150 kGy. This valley occurs at around 15x103mοc and is well known as oxygen-specific, indicative of a less positron trapping by oxygen atoms in some samples of higher dose radiation. It is postulated that the radiation will break the crosslinkings, allowing the trace water and oxygen molecules to be released from the sample surface. Excess NCO groups in ETPU would crosslink with urethane and urea groups to produce allophanate and biuret groups. After receiving a certain amount of electron irradiation, crosslinked allophanate and biuret groups would produce degradation. Thus, residual water and oxygen trapped in ETPU by the crosslinking would diffuse out. However, the irradiation doses up to 150 kGy in this experiment are still not large enough to induce strong degradation of urethane and urea groups

  9. The findings of F-18 FDG camera-based coincidence PET in acute leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, S. N.; Joh, C. W.; Lee, M. H. [Ajou University School of Medicine, Suwon (Korea, Republic of)

    2002-07-01

    We evaluated the usefulness of F-18 FDG coincidence PET (CoDe-PET) using a dual-head gamma camera in the assessment of patients with acute leukemia. F-18 FDG CoDE-PET studies were performed in 5 patients with acute leukemia (6 ALL and 2 AML) before or after treatment. CoDe-PET was performed utilizing a dual-head gamma camera equipped with 5/8 inch NaI(Tl) crystal. Image acquisition began 60 minutes after the injection of F-18 FDG in the fasting state. A whole trunk from cervical to inguinal regions or selected region were scanned. No attenuation correction was made and image reconstruction was done using filtered back-projection. CoDe-PET studies were evaluated visually. F-18 FDG image performed in 5 patients with ALL before therapy depicted multiple lymph node involvement and diffuse increased uptake involving axial skeleton, pelvis and femurs. F-18 FDG image done in 2 AML after chemotherapy showed only diffuse increased uptake in sternum, ribs, spine, pelvis and proximal femur and these may be due to G-CSF stimulation effect in view of drug history. But bone marrow histology showed scattered blast cell suggesting incomplete remission in one and completer remission in another. F-18 image done in 1 ALL after therapy showed no abnormal uptake. CoDe-PET with F-18 FDG in acute lymphoblastic lymphoma showed multiple lymphnode and bone marrow involvement in whole body. Therefore we conclude that CoDe-PET with F-18 FDG usefulness for evaluation of extent in acute lymphoblastic leukemia. But there was a limitation to assess therapy effectiveness during therapy due to reactive bone marrow.

  10. Imaging breakdown diagrams for bromobutyne isomers with photoelectron-photoion coincidence.

    Science.gov (United States)

    Bodi, Andras; Hemberger, Patrick

    2014-01-14

    Internal energy selected C4H5Br(+) ions were prepared by vacuum ultraviolet photoionization from the bromobutyne constitutional isomers 4-bromo-1-butyne, 1-bromo-2-butyne, and 3-bromo-1-butyne. The lowest energy dissociative photoionization channel is Br-loss. 1-Bromo-2-butyne and 3-bromo-1-butyne cations are not metastable, and based on the threshold photoionization breakdown diagrams and neutral internal energy distributions, 0 K appearance energies of E0 = 10.375 ± 0.010 and 10.284 ± 0.010 eV are obtained, respectively. A kinetic shift has been observed in the Br loss of the 4-bromo-1-butyne cation, and the experimental dissociation rates were also modeled to obtain E0 = 10.616 ± 0.030 eV. The energetics of the samples and nine C4H5 and C4H5(+) structures are explored using G4 theory, which suggests that only the staggered 4-bromo-1-butyne rotamer cation loses Br to form a high-energy cyclic C4H5(+) isomer, while the relative appearance energies indicate that 1-bromo-2-butyne and 3-bromo-1-butyne form the linear CH2CCCH3(+) ion. The subtraction scheme for hot electron suppression in threshold photoelectron-photoion coincidence (TPEPICO) is discussed, and is used to introduce velocity map imaging (VMI-)PEPICO and data analysis. The derived onsets and the dissociation rate curve show that modeling VMI-PEPICO data taken close above or below the disappearance energy of the parent ion to obtain imaging breakdown diagrams is a feasible approach also in the presence of a kinetic shift. Imaging breakdown diagrams are advantageous when signal levels are low or short acquisition times necessary, such as in the case of reactive intermediates or in time resolved experiments, and can also be used as a fast molecular thermometer. PMID:24108175

  11. Coincident mass extirpation of neotropical amphibians with the emergence of the infectious fungal pathogen Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Cheng, Tina L; Rovito, Sean M; Wake, David B; Vredenburg, Vance T

    2011-06-01

    Amphibians highlight the global biodiversity crisis because ∼40% of all amphibian species are currently in decline. Species have disappeared even in protected habitats (e.g., the enigmatic extinction of the golden toad, Bufo periglenes, from Costa Rica). The emergence of a fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been implicated in a number of declines that have occurred in the last decade, but few studies have been able to test retroactively whether Bd emergence was linked to earlier declines and extinctions. We describe a noninvasive PCR sampling technique that detects Bd in formalin-preserved museum specimens. We detected Bd by PCR in 83-90% (n = 38) of samples that were identified as positive by histology. We examined specimens collected before, during, and after major amphibian decline events at established study sites in southern Mexico, Guatemala, and Costa Rica. A pattern of Bd emergence coincident with decline at these localities is revealed-the absence of Bd over multiple years at all localities followed by the concurrent emergence of Bd in various species at each locality during a period of population decline. The geographical and chronological emergence of Bd at these localities also indicates a southbound spread from southern Mexico in the early 1970s to western Guatemala in the 1980s/1990s and to Monteverde, Costa Rica by 1987. We find evidence of a historical "Bd epidemic wave" that began in Mexico and subsequently spread to Central America. We describe a technique that can be used to screen museum specimens from other amphibian decline sites around the world.

  12. Coincidence of a high-fluence blazar outburst with a PeV-energy neutrino event

    Science.gov (United States)

    Kadler, M.; Krauß, F.; Mannheim, K.; Ojha, R.; Müller, C.; Schulz, R.; Anton, G.; Baumgartner, W.; Beuchert, T.; Buson, S.; Carpenter, B.; Eberl, T.; Edwards, P. G.; Eisenacher Glawion, D.; Elsässer, D.; Gehrels, N.; Gräfe, C.; Gulyaev, S.; Hase, H.; Horiuchi, S.; James, C. W.; Kappes, A.; Kappes, A.; Katz, U.; Kreikenbohm, A.; Kreter, M.; Kreykenbohm, I.; Langejahn, M.; Leiter, K.; Litzinger, E.; Longo, F.; Lovell, J. E. J.; McEnery, J.; Natusch, T.; Phillips, C.; Plötz, C.; Quick, J.; Ros, E.; Stecker, F. W.; Steinbring, T.; Stevens, J.; Thompson, D. J.; Trüstedt, J.; Tzioumis, A. K.; Weston, S.; Wilms, J.; Zensus, J. A.

    2016-08-01

    The astrophysical sources of the extraterrestrial, very high-energy neutrinos detected by the IceCube collaboration remain to be identified. Gamma-ray (γ-ray) blazars have been predicted to yield a cumulative neutrino signal exceeding the atmospheric background above energies of 100 TeV, assuming that both the neutrinos and the γ-ray photons are produced by accelerated protons in relativistic jets. As the background spectrum falls steeply with increasing energy, the individual events with the clearest signature of being of extraterrestrial origin are those at petaelectronvolt energies. Inside the large positional-uncertainty fields of the first two petaelectronvolt neutrinos detected by IceCube, the integrated emission of the blazar population has a sufficiently high electromagnetic flux to explain the detected IceCube events, but fluences of individual objects are too low to make an unambiguous source association. Here, we report that a major outburst of the blazar PKS B1424-418 occurred in temporal and positional coincidence with a third petaelectronvolt-energy neutrino event (HESE-35) detected by IceCube. On the basis of an analysis of the full sample of γ-ray blazars in the HESE-35 field, we show that the long-term average γ-ray emission of blazars as a class is in agreement with both the measured all-sky flux of petaelectronvolt neutrinos and the spectral slope of the IceCube signal. The outburst of PKS B1424-418 provides an energy output high enough to explain the observed petaelectronvolt event, suggestive of a direct physical association.

  13. True coincidence summing correction and mathematical efficiency modeling of a well detector

    Energy Technology Data Exchange (ETDEWEB)

    Jäderström, H., E-mail: henrik.jaderstrom@canberra.com [CANBERRA Industries Inc., 800 Research Parkway, Meriden, CT 06450 (United States); Mueller, W.F. [CANBERRA Industries Inc., 800 Research Parkway, Meriden, CT 06450 (United States); Atrashkevich, V. [Stroitely St 4-4-52, Moscow (Russian Federation); Adekola, A.S. [CANBERRA Industries Inc., 800 Research Parkway, Meriden, CT 06450 (United States)

    2015-06-01

    True coincidence summing (TCS) occurs when two or more photons are emitted from the same decay of a radioactive nuclide and are detected within the resolving time of the gamma ray detector. TCS changes the net peak areas of the affected full energy peaks in the spectrum and the nuclide activity is rendered inaccurate if no correction is performed. TCS is independent of the count rate, but it is strongly dependent on the peak and total efficiency, as well as the characteristics of a given nuclear decay. The TCS effects are very prominent for well detectors because of the high efficiencies, and make accounting for TCS a necessity. For CANBERRA's recently released Small Anode Germanium (SAGe) well detector, an extension to CANBERRA's mathematical efficiency calibration method (In Situ Object Calibration Software or ISOCS, and Laboratory SOurceless Calibration Software or LabSOCS) has been developed that allows for calculation of peak and total efficiencies for SAGe well detectors. The extension also makes it possible to calculate TCS corrections for well detectors using the standard algorithm provided with CANBERRAS's Spectroscopy software Genie 2000. The peak and total efficiencies from ISOCS/LabSOCS have been compared to MCNP with agreements within 3% for peak efficiencies and 10% for total efficiencies for energies above 30 keV. A sample containing Ra-226 daughters has been measured within the well and analyzed with and without TCS correction and applying the correction factor shows significant improvement of the activity determination for the energy range 46–2447 keV. The implementation of ISOCS/LabSOCS for well detectors offers a powerful tool for efficiency calibration for these detectors. The automated algorithm to correct for TCS effects in well detectors makes nuclide specific calibration unnecessary and offers flexibility in carrying out gamma spectral analysis.

  14. True coincidence summing correction and mathematical efficiency modeling of a well detector

    Science.gov (United States)

    Jäderström, H.; Mueller, W. F.; Atrashkevich, V.; Adekola, A. S.

    2015-06-01

    True coincidence summing (TCS) occurs when two or more photons are emitted from the same decay of a radioactive nuclide and are detected within the resolving time of the gamma ray detector. TCS changes the net peak areas of the affected full energy peaks in the spectrum and the nuclide activity is rendered inaccurate if no correction is performed. TCS is independent of the count rate, but it is strongly dependent on the peak and total efficiency, as well as the characteristics of a given nuclear decay. The TCS effects are very prominent for well detectors because of the high efficiencies, and make accounting for TCS a necessity. For CANBERRA's recently released Small Anode Germanium (SAGe) well detector, an extension to CANBERRA's mathematical efficiency calibration method (In Situ Object Calibration Software or ISOCS, and Laboratory SOurceless Calibration Software or LabSOCS) has been developed that allows for calculation of peak and total efficiencies for SAGe well detectors. The extension also makes it possible to calculate TCS corrections for well detectors using the standard algorithm provided with CANBERRAS's Spectroscopy software Genie 2000. The peak and total efficiencies from ISOCS/LabSOCS have been compared to MCNP with agreements within 3% for peak efficiencies and 10% for total efficiencies for energies above 30 keV. A sample containing Ra-226 daughters has been measured within the well and analyzed with and without TCS correction and applying the correction factor shows significant improvement of the activity determination for the energy range 46-2447 keV. The implementation of ISOCS/LabSOCS for well detectors offers a powerful tool for efficiency calibration for these detectors. The automated algorithm to correct for TCS effects in well detectors makes nuclide specific calibration unnecessary and offers flexibility in carrying out gamma spectral analysis.

  15. Clearance of an immunosuppressive virus from the CNS coincides with immune reanimation and diversification

    Directory of Open Access Journals (Sweden)

    McGavern Dorian B

    2007-06-01

    Full Text Available Abstract Once a virus infection establishes persistence in the central nervous system (CNS, it is especially difficult to eliminate from this specialized compartment. Therefore, it is of the utmost importance to fully understand scenarios during which a persisting virus is ultimately purged from the CNS by the adaptive immune system. Such a scenario can be found following infection of adult mice with an immunosuppressive variant of lymphocytic choriomeningitis virus (LCMV referred to as clone 13. In this study we demonstrate that following intravenous inoculation, clone 13 rapidly infected peripheral tissues within one week, but more slowly inundated the entire brain parenchyma over the course of a month. During the establishment of persistence, we observed that genetically tagged LCMV-specific cytotoxic T lymphocytes (CTL progressively lost function; however, the severity of this loss in the CNS was never as substantial as that observed in the periphery. One of the most impressive features of this model system is that the peripheral T cell response eventually regains functionality at ~60–80 days post-infection, and this was associated with a rapid decline in virus from the periphery. Coincident with this "reanimation phase" was a massive influx of CD4 T and B cells into the CNS and a dramatic reduction in viral distribution. In fact, olfactory bulb neurons served as the last refuge for the persisting virus, which was ultimately purged from the CNS within 200 days post-infection. These data indicate that a functionally revived immune response can prevail over a virus that establishes widespread presence both in the periphery and brain parenchyma, and that therapeutic enhancement of an existing response could serve as an effective means to thwart long term CNS persistence.

  16. A First Look at the Impact of Electric Vehicle Charging on the Electric Grid in the EV Project

    Energy Technology Data Exchange (ETDEWEB)

    Stephen L. Schey; John G. Smart; Don R. Scoffield

    2012-05-01

    ECOtality was awarded a grant from the U.S. Department of Energy to lead a large-scale electric vehicle charging infrastructure demonstration, called The EV Project. ECOtality has partnered with Nissan North America, General Motors, the Idaho National Laboratory, and others to deploy and collect data from over 5,000 Nissan LEAFsTM and Chevrolet Volts and over 10,000 charging systems in 18 regions across the United States. This paper summarizes usage of residential charging units in The EV Project, based on data collected through the end of 2011. This information is provided to help analysts assess the impact on the electric grid of early adopter charging of grid-connected electric drive vehicles. A method of data aggregation was developed to summarize charging unit usage by the means of two metrics: charging availability and charging demand. Charging availability is plotted to show the percentage of charging units connected to a vehicle over time. Charging demand is plotted to show charging demand on the electric gird over time. Charging availability for residential charging units is similar in each EV Project region. It is low during the day, steadily increases in evening, and remains high at night. Charging demand, however, varies by region. Two EV Project regions were examined to identify regional differences. In Nashville, where EV Project participants do not have time-of-use electricity rates, demand increases each evening as charging availability increases, starting at about 16:00. Demand peaks in the 20:00 hour on weekdays. In San Francisco, where the majority of EV Project participants have the option of choosing a time-of-use rate plan from their electric utility, demand spikes at 00:00. This coincides with the beginning of the off-peak electricity rate period. Demand peaks at 01:00.

  17. Understanding the Linkage between Charging Network Coverage and Charging Opportunity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Changzheng [ORNL; Lin, Zhenhong [ORNL; Kontou, Eleftheria [University of Florida, Gainesville; Wu, Xing [Lamar University

    2016-01-01

    Using GPS-based travel survey data, this paper estimates the relationship between public charging network coverage and charging opportunity, defined as the probability of being able to access public charging for a driver at one of his/her stops or at one travel day. Understanding this relationship is of important interests to the electric vehicle industry and government in determining appropriate charging infrastructure deployment level and estimating the impact of public charging on market adoption of electric vehicles. The analysis finds that drivers trip destinations concentrate on a few popular places. If top 1% of most popular places are installed with public chargers, on average, drivers will be able to access public charging at 20% of all their stops and 1/3 of their travel days; If 20% of most popular places are installed with public chargers, drivers will be able to access public charging at 89% of all their stops and 94% of their travel days. These findings are encouraging, implying charging network can be efficiently designed by concentrating at a few popular places while still providing a high level of charging opportunity.

  18. An integrated CMOS time-to-digital converter for coincidence detection in a liquid xenon PET prototype

    OpenAIRE

    Bourrion, O.; Gallin-Martel, L.

    2005-01-01

    A Time to Digital Converter was designed (CMOS 0.35 μm) to perform coincidence detection in a Liquid Xenon PET prototype. This circuit proved to be able to operate at 150 K, while showing a resolution better than 250 ps. The circuit enables a low readout dead time (

  19. On coincidence of Alday-Maldacena-regularized $\\sigma$-model and Nambu-Goto areas of minimal surfaces

    OpenAIRE

    Popolitov, A.

    2007-01-01

    For the $\\sigma$-model and Nambu-Goto actions, values of the Alday-Maldacena-regularized actions are calculated on solutions of the equations of motion with constant non-regularized Lagrangian. It turns out that these values coincide up to a factor, independent of boundary conditions.

  20. Walther Bothe and Bruno Rossi: the birth and development of coincidence methods in cosmic-ray physics

    CERN Document Server

    Bonolis, Luisa

    2011-01-01

    Theoretical and experimental developments in the 1920s that accompanied the birth of coincidence methods, as well as later crucial applications during the 1930s and 1940s are presented. First, in 1924 Walther Bothe and Hans Geiger applied a coincidence method to the study of Compton scattering with Geiger needle counters. Their historical experiment confirmed the physical reality of radiation quanta and established beyond doubt the strict validity of conservation principles in elementary processes. Then, at the end of the 1920s, Bothe and Werner Kolh\\"orster coupled the coincidence technique with the brand-new Geiger-M\\"uller counter to study cosmic rays, and marked the start of cosmic-ray research as truly a branch of physics. In this framework the coincidence method was further refined by Bruno Rossi, who developed a vacuum-tube electronic device, capable of registering the simultaneous occurrence of electrical pulses from any number of counters with a tenfold improvement in time resolution. The electronic ...

  1. Coincidence grain boundary and role of primary recrystallized grain growth on secondary recrystallization texture evolution in Fe-3%Si alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yoshitomi, Y.; Takahashi, N. (Nippon Steel Corp., Kitakyushu (Japan). Yawata R D Lab.); Ushigami, Y.; Harase, J.; Nakayama, T.; Masui, H. (Nippon Steel Corp., Chiba (Japan). Steel Research Lab.)

    1994-08-01

    Secondary recrystallization behavior in the presence of AlN in Fe-3%Si alloy was investigated with special reference to the influence of primary recrystallized grain growth on secondary recrystallization texture. The more dominant grain growth was marked by the evolution of [110]<001> secondary recrystallized grains in the higher temperature range. In the case of smaller primary recrystallized grains, the [110]<227> secondary recrystallized grains were mainly evolved on annealing at the lower temperature range. The frequency of [Sigma]9 coincidence boundaries in relation to the [110]<001> texture component was higher than that of [Sigma]5 coincidence boundaries in relation to [110]<227> component. The mechanism of these evolutions of secondary recrystallization texture can be explained by the assumption that the [Sigma]5 coincidence boundaries are more mobile than the [Sigma]9 coincidence boundaries in the lower temperature range. The primary recrystallized grain growth is considered to have a role in determining what should be the secondary recrystallization temperature.

  2. Recruitment failure of coastal predatory fish in the Baltic Sea coincident with an offshore ecosystem regime shift

    NARCIS (Netherlands)

    Ljunggren, Lars; Sandstrom, Alfred; Bergstrom, Ulf; Mattila, Johanna; Lappalainen, Antti; Johansson, Gustav; Sundblad, Goran; Casini, Michele; Kaljuste, Olavi; Eriksson, Britas Klemens

    2010-01-01

    Ljunggren, L., Sandstrom, A., Bergstrom, U., Mattila, J., Lappalainen, A., Johansson, G., Sundblad, G., Casini, M., Kaljuste, O., and Eriksson, B. K. 2010. Recruitment failure of coastal predatory fish in the Baltic Sea coincident with an offshore ecosystem regime shift. - ICES Journal of Marine Sci

  3. About Compact and Sequentially Compact Coincide in Topological Groups with the Axiom (A1)

    Institute of Scientific and Technical Information of China (English)

    Lina

    2004-01-01

    This paper is concerned with the relation between the compactness and sequential compactness in a topological space or a topological group, and show that the compactness and sequential compactness coincide in a topol.ogical group with the axiom (A1).

  4. Coincidence Theorems with Applications to Minimax Inequalities, Section Theorem, Best Approximation and Multiobjective Games in Topological Spaces

    Institute of Scientific and Technical Information of China (English)

    Lei DENG; Ming Ge YANG

    2006-01-01

    Some new coincidence theorems involving admissible set-valued mappings are proved in general noncompact topological spaces. As applications, some new minimax inequalities, section theorem, best approximation theorem, existence theorems of weighted Nash equilibria and Pareto equilibria for multiobjective games are given in general topological spaces.

  5. Study of a 4πβ-γ coincidence system for absolute radionuclide activity measurement using plastic scintillators

    International Nuclear Information System (INIS)

    The present work was intended to study a coincidence system 4π(PS)β-γ for absolute activity measurement using plastic scintillators in 4π geometry. Along with experiments on the coincidence system, simulations were also performed applying the Monte Carlo Method, by means of codes PENELOPE and ESQUEMA. These simulations were performed in order to calculate the extrapolation curve of the coincidence system 4π(PS)β-γ and compare it to experimental data. A new geometry was proposed to the coincidence system adding up a second photomultiplier tube to the previous system for improving light collection from the plastic scintillator, as this system presented limitations in the minimum detected energy due to the presence of electronic noise and low gain. The results show that an improvement in the signal-to-noise ratio was obtained, as well as in the minimum detected energy. Moreover, there was an increase in the detection efficiency. With these modifications, it is now possible to calibrate radionuclides which emit low energy electrons or X-rays, increasing the number of radionuclides that can be standardized with this type of system.(author)

  6. A Compton-suppression spectrometer for γ-γ coincidence measurements: Large solid angle and excellent suppression

    NARCIS (Netherlands)

    Aarts, H.J.M.; Poel, C.J. van der; Scherpenzeel, D.E.C.; Arciszewski, H.F.R.; Engelbertink, G.A.P.

    1980-01-01

    For γ-γ coincidence measurements a Compton-suppression spectrometer with a large solid angle of 120 msr and excellent suppression has been designed. The dimensions of the NaI anticoincidence shield have been optimized by means of Monte Carlo calculations. The NaI shield has a length of 35 cm and a d

  7. Battery charging stations

    Energy Technology Data Exchange (ETDEWEB)

    Bergey, M.

    1997-12-01

    This paper discusses the concept of battery charging stations (BCSs), designed to service rural owners of battery power sources. Many such power sources now are transported to urban areas for recharging. A BCS provides the opportunity to locate these facilities closer to the user, is often powered by renewable sources, or hybrid systems, takes advantage of economies of scale, and has the potential to provide lower cost of service, better service, and better cost recovery than other rural electrification programs. Typical systems discussed can service 200 to 1200 people, and consist of stations powered by photovoltaics, wind/PV, wind/diesel, or diesel only. Examples of installed systems are presented, followed by cost figures, economic analysis, and typical system design and performance numbers.

  8. Ac Hybrid Charge Controller

    Directory of Open Access Journals (Sweden)

    Shalini S. Durgam

    2015-03-01

    Full Text Available One of the primary needs for socio-economic development in any nation in the world is the provision of reliable electricity supply systems with lower carbon footprint levels. The purpose of this work is the development of a hybrid Power system that harnesses the renewable energy in sun and electricity to generate electricity. The working model can able to run on dual mode- solar and electricity. It can also be driven independently either by solar or electricity. The battery can be charge from solar panel (40W or by power supply. The household single phase A.C. power supply of 230V is converted into 12V D.C. using step down transformer and rectifying circuit. The working model can achieve energy saving, low carbon emission, environmental protection for the upcoming future of human life.

  9. 12 CFR 226.4 - Finance charge.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Finance charge. 226.4 Section 226.4 Banks and... LENDING (REGULATION Z) General § 226.4 Finance charge. (a) Definition. The finance charge is the cost of...) Charges by third parties. The finance charge includes fees and amounts charged by someone other than...

  10. Charge contribution to patch-charged microparticle adhesion

    Science.gov (United States)

    Vallabh, Chaitanya Krishna Prasad; Vahdat, Armin Saeedi; Cetinkaya, Cetin

    2014-11-01

    Microparticle adhesion influenced by electrostatic charge has been a significant research interest for over past three decades or so in a wide spectrum of areas of interest from manufacturing (electrophotography, powder technology, metallurgy, and semi-conductor manufacturing) to natural phenomena (desert sandstorms and northern lights (auroras)). However, over the years, as a result of the strong discrepancies between the experimental adhesion measurements data and theoretical predictions, some key issues regarding the contributors of adhesion forces in charged microparticles and the nature of surface charge distribution still remain unresolved. In the current work, a non-contact ultrasonic approach is presented and employed for understanding the nature of charge distribution on a single microparticle and determining the effect of electrostatic charge on its adhesion in a non-invasive manner. From the vibrational spectra of the charged particle response to the ultrasonic substrate oscillations under various electrostatic loading conditions, three distinct shifting patterns of vibrational (rocking) resonance frequencies are observed for each level of applied substrate surface voltage, implying an un-symmetric force field on the particle, thus depicting non-uniform non-symmetric surface charge distribution on its surface. Also, a simple mathematical model was presented and employed for predicting the equivalent bulk charge on a single microparticle (toner) from resonance frequency shifts. In summary, it is found that the charge levels reported here are consistent with the previously published data, and it is demonstrated that, in a non-invasive manner, non-uniform charge distribution on a single microparticle can be observed and its total charge can be predicted.

  11. Exact solutions of charged wormhole

    OpenAIRE

    Kim, Sung-Won; Lee, Hyunjoo

    2001-01-01

    In this paper, the backreaction to the traversable Lorentzian wormhole spacetime by the scalar field or electric charge is considered to find the exact solutions. The charges play the role of the additional matter to the static wormhole which is already constructed by the exotic matter. The stability conditions for the wormhole with scalar field and electric charge are found from the positiveness and flareness for the wormhole shape function.

  12. Charged Polaritons with Spin 1

    Directory of Open Access Journals (Sweden)

    Minasyan V.

    2011-04-01

    Full Text Available We present a new model for metal which is based on the stimulated vibration of in- dependent charged Fermi-ions, representing as independent harmonic oscillators with natural frequencies, under action of longitudinal and transverse elastic waves. Due to application of the elastic wave-particle principle and ion-wave dualities, we predict the existence of two types of charged Polaritons with spin 1 which are induced by longitu- dinal and transverse elastic fields. As result of presented theory, at small wavenumbers, these charged polaritons represent charged phonons.

  13. Charged Polaritons with Spin 1

    Directory of Open Access Journals (Sweden)

    Samoilov V.

    2011-04-01

    Full Text Available We present a new model for metal which is based on the stimulated vibration of independent charged Fermi-ions, representing as independent harmonic oscillators with natural frequencies, under action of longitudinal and transverse elastic waves. Due to application of the elastic wave-particle principle and ion-wave dualities, we predict the existence of two types of charged Polaritons with spin 1 which are induced by longitudinal and transverse elastic fields. As result of presented theory, at small wavenumbers, these charged polaritons represent charged phonons.

  14. Charge transport in polymeric transistors

    Directory of Open Access Journals (Sweden)

    Alberto Salleo

    2007-03-01

    Full Text Available Polymeric semiconductors have attracted much attention because of their possible use as active materials in printed electronics. Thin-film transistors (TFTs are a convenient tool for studying charge-transport physics in conjugated polymers. Two families of materials are reviewed here: fluorene copolymers and polythiophenes. Because charge transport is highly anisotropic in molecular conductors, the electrical properties of conjugated polymers are strongly dependent on microstructure. Molecular weight, polydispersity, and regioregularity all affect morphology and charge-transport in these materials. Charge transport models based on microstructure are instrumental in identifying the electrical bottlenecks in these materials.

  15. Butterflies with rotation and charge

    CERN Document Server

    Reynolds, Alan P

    2016-01-01

    We explore the butterfly effect for black holes with rotation or charge. We perturb rotating BTZ and charged black holes in 2+1 dimensions by adding a small perturbation on one asymptotic region, described by a shock wave in the spacetime, and explore the effect of this shock wave on the length of geodesics through the wormhole and hence on correlation functions. We find the effect of the perturbation grows exponentially at a rate controlled by the temperature; dependence on the angular momentum or charge does not appear explicitly. We comment on issues affecting the extension to higher-dimensional charged black holes.

  16. Scalar clouds in charged stringy black hole-mirror system

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ran; Zhao, Junkun; Wu, Xinghua; Zhang, Yanming [Henan Normal University, Department of Physics, Xinxiang (China)

    2015-04-15

    It was reported that massive scalar fields can form bound states around Kerr black holes (Herdeiro and Radu, Phys. Rev. Lett. 112:221101, 2014). These bound states are called scalar clouds; they have a real frequency ω = mΩ{sub H}, where m is the azimuthal index and Ω{sub H} is the horizon angular velocity of Kerr black hole. In this paper, we study scalar clouds in a spherically symmetric background, i.e. charged stringy black holes, with the mirror-like boundary condition. These bound states satisfy the superradiant critical frequency condition ω = qΦ{sub H} for a charged scalar field, where q is the charge of the scalar field, and Φ{sub H} is the horizon's electrostatic potential. We show that, for the specific set of black hole and scalar field parameters, the clouds are only possible for specific mirror locations r{sub m}. It is shown that analytical results of the mirror location r{sub m} for the clouds perfectly coincide with numerical results in the qQ << 1 regime. We also show that the scalar clouds are also possible when the mirror locations are close to the horizon. Finally, we provide an analytical calculation of the specific mirror locations rm for the scalar clouds in the qQ >> 1 regime. (orig.)

  17. Solar Wind Compression Generation of Coincident EMIC and Whistler Mode Chorus and Hiss Waves

    Science.gov (United States)

    Halford, Alexa; Mann, Ian

    2016-07-01

    Electron radiation belt dynamics are controlled by the competition of multiple acceleration and loss mechanisms. Electromagnetic ion cyclotron (EMIC), chorus, and hiss waves have all been implicated as potential loss mechanisms of radiation belt electrons along with Chorus waves proposed as a mechanism for accelerating the lower energy source population to MeV energies. Understanding the relative importance of these waves as well as where and under what conditions they are generated is vital to predicting radiation belt dynamics. Although the size of the solar wind compression on 9 January 2014 event discussed here was modest, it has given us an opportunity to observe clearly how a magnetospheric compression can lead to the generation of EMIC, chorus, and hiss waves. The ICME generated shock encountered the Earth's magnetosphere on 9 January 2014 at ~20:11 UT, and the Van Allen Probes observe the coincident excitation of EMIC and Chorus waves outside the plasmasphere, and hiss weaves inside the plasmasphere. As the shock encountered the magnetosphere, an electric field impulse was observed to generate an increase in temperature anisotropy for both ions and electrons. This increased temperature anisotropy led to increased wave growth on both the ion and electron cyclotron branches. The simultaneous generation of multiple types of waves may lead to significant impacts on the acceleration and loss of radiation belt electrons, especially during geomagnetic compressions observed during the substorms, and the storm sudden commencement and main phases of geomagnetic storms, as well as during quiet time sudden impulse events. For example, the excitation of both EMIC and chorus waves at the same place, and at the same time, may complicate studies seeking a causal connection between specific individual plasma wave bursts and observations of particle precipitation into the atmosphere. During this relatively small event BARREL had three payloads in conjunction with the Van

  18. A first search for coincident gravitational waves and high energy neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Di Palma, Irene

    2012-08-14

    We present the results of the first search for gravitational wave (GW) bursts associated with high energy neutrinos (HEN), detected by the underwater neutrino telescope ANTARES in its 5 lines configuration, during the fifth LIGO science run and first Virgo science run. The data used in this analysis were collected from February 9 to September 30 2007. Cataclysmic cosmic events with burst activity can be plausible sources of concomitant GW and HEN. Such messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, in particular at high energy. In a first stage of the analysis, HEN candidates, detected during the operation of the ANTARES Telescope were selected. In a second stage, GW candidates in time and space correlation with the HEN events were searched for in LIGO and Virgo data. During this first joint GW+HEN search, no coincident event was observed. We set limits on the population density of different types of concurrent GW-HEN sources. For short GRB-like sources, related to the merger of two compact objects, the density upper limit is {rho}{sub GW-HEN}{sup SGRB}

  19. Perfect/complete scattering experiments. Probing quantum mechanics on atomic and molecular collisions and coincidences

    Energy Technology Data Exchange (ETDEWEB)

    Lohmann, Bernd [Muenster Univ. (Germany). Inst. fuer Theoretische Physik 1; Grum-Grzhimailo, Alexei N. [Moscow State Univ. (Russian Federation). Skobeltsyn Inst. of Nuclear Physics; Kleinpoppen, Hans

    2013-07-01

    Derives parameters for electrons, photons, atoms, ions, molecules calculated from theory. Delivers the quantum mechanical knowledge of atomic and molecular physics. Presents state-of-the-art experiments in atomic and molecular physics and related theoretical approaches. The main goal of this book is to elucidate what kind of experiment must be performed in order to determine the full set of independent parameters which can be extracted and calculated from theory, where electrons, photons, atoms, ions, molecules, or molecular ions may serve as the interacting constituents of matter. The feasibility of such perfect' and-or 'complete' experiments, providing the complete quantum mechanical knowledge of the process, is associated with the enormous potential of modern research techniques, both, in experiment and theory. It is even difficult to overestimate the role of theory in setting of the complete experiment, starting with the fact that an experiment can be complete only within a certain theoretical framework, and ending with the direct prescription of what, and in what conditions should be measured to make the experiment 'complete'. The language of the related theory is the language of quantum mechanical amplitudes and their relative phases. This book captures the spirit of research in the direction of the complete experiment in atomic and molecular physics, considering some of the basic quantum processes: scattering, Auger decay and photo-ionization. It includes a description of the experimental methods used to realize, step by step, the complete experiment up to the level of the amplitudes and phases. The corresponding arsenal includes, beyond determining the total cross section, the observation of angle and spin resolved quantities, photon polarization and correlation parameters, measurements applying coincidence techniques, preparing initially polarized targets, and even more sophisticated methods. The 'complete' experiment is

  20. Perfect/complete scattering experiments. Probing quantum mechanics on atomic and molecular collisions and coincidences

    International Nuclear Information System (INIS)

    Derives parameters for electrons, photons, atoms, ions, molecules calculated from theory. Delivers the quantum mechanical knowledge of atomic and molecular physics. Presents state-of-the-art experiments in atomic and molecular physics and related theoretical approaches. The main goal of this book is to elucidate what kind of experiment must be performed in order to determine the full set of independent parameters which can be extracted and calculated from theory, where electrons, photons, atoms, ions, molecules, or molecular ions may serve as the interacting constituents of matter. The feasibility of such perfect' and-or 'complete' experiments, providing the complete quantum mechanical knowledge of the process, is associated with the enormous potential of modern research techniques, both, in experiment and theory. It is even difficult to overestimate the role of theory in setting of the complete experiment, starting with the fact that an experiment can be complete only within a certain theoretical framework, and ending with the direct prescription of what, and in what conditions should be measured to make the experiment 'complete'. The language of the related theory is the language of quantum mechanical amplitudes and their relative phases. This book captures the spirit of research in the direction of the complete experiment in atomic and molecular physics, considering some of the basic quantum processes: scattering, Auger decay and photo-ionization. It includes a description of the experimental methods used to realize, step by step, the complete experiment up to the level of the amplitudes and phases. The corresponding arsenal includes, beyond determining the total cross section, the observation of angle and spin resolved quantities, photon polarization and correlation parameters, measurements applying coincidence techniques, preparing initially polarized targets, and even more sophisticated methods. The 'complete' experiment is, until today, hardly to perform

  1. Unexpected decline in tuberculosis cases coincident with economic recession -- United States, 2009

    Directory of Open Access Journals (Sweden)

    Winston Carla A

    2011-11-01

    Full Text Available Abstract Background Since 1953, through the cooperation of state and local health departments, the U.S. Centers for Disease Control and Prevention (CDC has collected information on incident cases of tuberculosis (TB disease in the United States. In 2009, TB case rates declined -11.4%, compared to an average annual -3.8% decline since 2000. The unexpectedly large decline raised concerns that TB cases may have gone unreported. To address the unexpected decline, we examined trends from multiple sources on TB treatment initiation, medication sales, and laboratory and genotyping data on culture-positive TB. Methods We analyzed 142,174 incident TB cases reported to the U. S. National Tuberculosis Surveillance System (NTSS during January 1, 2000-December 31, 2009; TB control program data from 59 public health reporting areas; self-reported data from 50 CDC-funded public health laboratories; monthly electronic prescription claims for new TB therapy prescriptions; and complete genotyping results available for NTSS cases. Accounting for prior trends using regression and time-series analyses, we calculated the deviation between observed and expected TB cases in 2009 according to patient and clinical characteristics, and assessed at what point in time the deviation occurred. Results The overall deviation in TB cases in 2009 was -7.9%, with -994 fewer cases reported than expected (P Conclusions Our assessments show that the decline in reported TB was not an artifact of changes in surveillance methods; rather, similar declines were found through multiple data sources. While the steady decline of TB cases before 2009 suggests ongoing improvement in TB control, we were not able to identify any substantial change in TB control activities or TB transmission that would account for the abrupt decline in 2009. It is possible that other multiple causes coincident with economic recession in the United States, including decreased immigration and delayed access to

  2. A curious coincidence: mosquito biodiversity and the limits of the Japanese encephalitis virus in Australasia

    Directory of Open Access Journals (Sweden)

    Russell Richard C

    2007-06-01

    existence of divergent mitochondrial lineages within Cx. annulirostris and Cx. palpalis helps explain the difficulty of using adult morphology to identify Cx. annulirostris and its ecological diversity. Notably, the southern limit of the PNG lineages of Cx. annulirostris coincides exactly with the current southern limit of JEV activity in Australasia suggesting that variation in these COI lineages may be the key to why JEV has not yet established yet on mainland Australia.

  3. A first search for coincident gravitational waves and high energy neutrinos

    International Nuclear Information System (INIS)

    We present the results of the first search for gravitational wave (GW) bursts associated with high energy neutrinos (HEN), detected by the underwater neutrino telescope ANTARES in its 5 lines configuration, during the fifth LIGO science run and first Virgo science run. The data used in this analysis were collected from February 9 to September 30 2007. Cataclysmic cosmic events with burst activity can be plausible sources of concomitant GW and HEN. Such messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, in particular at high energy. In a first stage of the analysis, HEN candidates, detected during the operation of the ANTARES Telescope were selected. In a second stage, GW candidates in time and space correlation with the HEN events were searched for in LIGO and Virgo data. During this first joint GW+HEN search, no coincident event was observed. We set limits on the population density of different types of concurrent GW-HEN sources. For short GRB-like sources, related to the merger of two compact objects, the density upper limit is ρGW-HENSGRB -2Mpc-3 yr-1. This limit is several orders of magnitude higher than theoretical predictions. For long GRB-like sources, related to the collapse of massive stars, the limit is ρGW-HENLGRB -3Mpc-3yr-1. This limit is within a factor of ten of the optimistic predictions and shows that future searches at improved sensitivities may yield detections or constraining upper limits. We also place a lower limit on the distance to GW sources associated with every HEN trigger. We are able to rule out the existence of coalescing binary neutron star systems of (1.35-1.35)Msun and black hole- neutron star systems of (5-1.35)Msun up to distances that are typically of 5 Mpc and 10 Mpc respectively. For generic waveform limits in the low frequency band typical distance limits can be as high as 17 Mpc.

  4. The Rationale of Crisis Management – On the Handling of Coincidence in Economic Situation

    Directory of Open Access Journals (Sweden)

    Peter Bendixen

    2010-07-01

    Full Text Available The subject of this essay is too complex a problem as to cover all details in depth and, thus, draws its attention only to core aspects of the handling of coincidence leaving out sophisticated studies and analytic findings as well as detailed reference to economic literature though there is not very much. On the other hand, for a lot of actual as well as general reasons, the subject is too important a matter as to ignore the serious methodological problems of crisis management, which are rooted in some politically still active bias hidden in orthodox neo-classical economics (Stiglitz 2010. If crisis management continues to follow traditional rationales, it will fail realizing the increasing dynamic of crises within the globalising economies of the world. No existing economy can be considered as an isolated system of its own embedded in a stable composition of societal surroundings. Obviously, many a critical situation has its origin in the sphere of civilization, of political discrepancies, and of administrative inflexibilities. On the other hand, any grave amplitude of markets would touch the entire social surrounding. The belief in the markets’ strength of self-regulation is a dangerous construction of orthodox economics (Bendixen 2009b, 2010. The view on crises suggested here is that of a holistic approach to understand a critical situation. Any interpretation of a situation includes empirical dates and figures based on analytic research, but solving a problem is not an act of logical derivation from findings, as if a solution can be excavated in the mud of reality by empirical studies only. Empirical figures report events of the past; the future does not reveal any empiricism. This would be a contradiction in itself. The end of a crisis as well as the search for solutions to fight the problems revealed is unavoidably a view into the future. Therefore, the rationale of crisis management cannot be made of pure empiricism but should include a

  5. Dispersion of charged tracers in charged porous media

    NARCIS (Netherlands)

    B. Rotenberg; I. Pagonabarraga; D. Frenkel

    2008-01-01

    We report a lattice-Boltzmann scheme to compute the dispersion of charged tracers in charged porous media under the combined effect of advection, diffusion and electro-migration. To this end, we extend the moment propagation approach, introduced to study the dispersion of neutral tracers (Lowe C. an

  6. A tandem time–of–flight spectrometer for negative–ion/positive–ion coincidence measurements with soft x-ray excitation

    Energy Technology Data Exchange (ETDEWEB)

    Stråhlman, Christian, E-mail: Christian.Strahlman@maxlab.lu.se; Sankari, Rami; Nyholm, Ralf [MAX IV Laboratory, Lund University, P.O. Box 118, 22100 Lund (Sweden); Kivimäki, Antti [Consiglio Nazionale delle Ricerche—Istituto Officina dei Materiali, Laboratorio TASC, 34149 Trieste (Italy); Richter, Robert [Elettra–Sincrotrone Trieste, Area Science Park, 34149 Trieste (Italy); Coreno, Marcello [Consiglio Nazionale delle Ricerche—Istituto di Struttura della Materia, 34149 Trieste (Italy)

    2016-01-15

    We present a newly constructed spectrometer for negative–ion/positive–ion coincidence spectroscopy of gaseous samples. The instrument consists of two time–of–flight ion spectrometers and a magnetic momentum filter for deflection of electrons. The instrument can measure double and triple coincidences between mass–resolved negative and positive ions with high detection efficiency. First results include identification of several negative–ion/positive–ion coincidence channels following inner-shell photoexcitation of sulfur hexafluoride (SF{sub 6})

  7. Charge transfer in multicomponent oxides

    Science.gov (United States)

    Kohan, A. F.; Ceder, G.

    1998-02-01

    The transfer of charge between different ions in an oxide plays an essential role in the stability of these compounds. Since small variations in charge can introduce large changes in the total energy, a correct description of this phenomenon is critical. In this work, we show that the ionic charge in oxides can strongly depend on its atomic environment. A model to assign point charges to atoms as a function of their atomic environment has recently been proposed for binary alloys [C. Wolverton, A. Zunger, S. Froyen, and S.-H. Wei, Phys. Rev. B 54, 7843 (1996)] and proven to be very successful in screened solids such as semiconductors and metals. Here, we extend this formalism to multicomponent oxides and we assess its applicability. The simple point-charge model predicts a linear relation between the charge on an atom and the number of unlike neighbors, and between the net value of the charge and the Coulomb field at a given site. The applicability of this approach is tested in a large-supercell self-consistent tight-binding calculation for a random Zr-Ca-O alloy. The observed fluctuations of the ionic charge about the average linear behavior (as a function of the number of unlike neighbors) was larger than 0.25 electrons even when many shells of atomic neighbors were considered in the fit. This variation is significant since it can introduce large errors in the electrostatic energy. On the other hand, for small absolute values of the charge, the ionic charge varied linearly with the Coulomb field, in agreement with previous findings. However, for large Coulomb fields, this function saturates at the formal chemical charge.

  8. Absolute standardization of {sup 106}Ru by anti-coincidence method; Padronizacao absoluta do {sup 106}Ru pelo metodo de anticoincidencia

    Energy Technology Data Exchange (ETDEWEB)

    Silva, C.J. da; Poledna, R.; Tahuata, L., E-mail: eduarda.rezende@ifrj.edu.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ/LNMRI), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes; Rezende, E.A.; Lopes, R.T. [Coordenacao dos Programas de Pos-Graducacao em Engenharia (LIN/PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The system of absolute standardization activity of radionuclide by anti-coincidence counting and live-time techniques was implemented at LNMRI in 2008 to reduce the impacts of some influence factors in the determination of the activity with coincidence counting technique used for decades in the lab, for example, the measurement time. With the anti-coincidence system, the variety of radionuclides that can be calibrated by LNMRI was increased, in relation to the type of decay. The objective of this work is the standardization of {sup 106}Ru by the method of counting anti-coincidence and estimate its measurement uncertainties. (author)

  9. Realisation of a {beta} spectrometer solenoidal and a double {beta} spectrometer at coincidence; Realisation d'un spectrometre {beta} solenoidal et d'un double spectrometre {beta} a coincidence

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-06-15

    The two spectrometers have been achieved to tackle numerous problems of nuclear spectrometry. They possess different fields of application that complete themselves. The solenoidal spectrometer permits the determination of the energy limits of {beta} spectra and of their shape; it also permits the determination of the coefficients of internal conversion and reports {alpha}{sub K} / {alpha}{sub L} and it is especially efficient for the accurate energy levels of the {gamma} rays by photoelectric effect. The double coincidence spectrometer has been conceived to get a good efficiency in coincidence: indeed, the sum of the solid angles used for the {beta} and {gamma} emission is rather little lower to 4{pi} steradians. To get this efficiency, one should have sacrificed a little the resolution that is lower to the one obtained with the solenoidal spectrometer for a same brightness. Each of the elements of the double spectrometer can also be adapted to the study of angular correlations {beta}{gamma} and e{sup -}{gamma}. In this use, it is superior to the thin magnetic lens used up to here. The double spectrometer also permits the survey of the coincidences e{sup -}e{sup -}, e{sup -}{beta} of a equivalent way to a double lens; it can also be consider some adaptation for the survey of the angular correlations e{sup -}e{sup -}, e{sup -}{beta}. Finally, we applied the methods by simple spectrometry and by coincidence spectrometry, to the study of the radiances of the following radioelements: {sup 76}As (26 h), {sup 122}Sb (2,8 j), {sup 124}Sb (60 j), {sup 125}Sb (2,7 years). (M.B.) [French] Les deux spectrometres qui ont ete realises permettent d'aborder un grand nombre de problemes de spectrometrie nucleaire. Ils possedent des champs d'application tres differents qui se completent. Le spectrometre solenoidal permet la determination des energies limites des spectres {beta} et de leur forme; il permet aussi la determination des coefficients de conversion interne et

  10. Coincidence of flowering time and the productivity and quality of cauliflower hybrid seeds Coincidência de florescimento entre linhagens de couve-flor na produtividade e qualidade de sementes híbridas

    Directory of Open Access Journals (Sweden)

    Marcelo Fontanetti Verdial

    2001-09-01

    Full Text Available The missing of flowering synchronization between the self-incompatible lines in a crop field of cauliflower hybrid seeds besides making the seed production smaller can compromise the genetic purity of them. The coincidence of the flowering time between two cauliflower lines was examined to study its effect on the productivity and quality of hybrid seeds. The treatments consisted of six different sowing dates, every fifteen days, using a self-incompatible tropical line pollinated by a winter line which does not present self-incompatibility. The following characteristics were evaluated: leaf average area and number of flowers per plant, number of siliques per plant, number and weight of seeds per plant, weight of thousand seeds and average number of seeds per silique. The germination standard test and genetic seed purity were determined for each treatment. The coincident flowering season between cauliflower lines affects directly the productivity and the genetic quality of the produced hybrid seeds. The closer the flowering time coincidence between the lines, the greater the number of seeds per silique and the smaller the percentage of non-hybrid seedlings. However, the coincidence of the flowering season between lines was found to influence physiological seed quality.A falta de sincronismo de florescimento entre as linhagens auto incompatíveis em um campo de produção de sementes híbridas de couve flor pode além de reduzir a produção de sementes comprometer a pureza genética das mesmas. Com o objetivo de estudar o efeito da coincidência de florescimento entre linhagens de couve-flor na produtividade e qualidade de sementes híbridas, foi realizado o presente experimento. Os tratamentos consistiram em seis diferentes épocas de semeadura, espaçadas a cada quinze dias, de uma linhagem de verão auto-incompatível que foi polinizada por uma linhagem de inverno que não apresenta auto-incompatibilidade. Observou-se a coincidência do

  11. Studies of the AgM5N45N4.5 spectrum of disordered Ag0.5Pd0.5 alloy by Auger photoelectron coincidence spectroscopy (APECS)

    International Nuclear Information System (INIS)

    Full text: The Auger electron emission process from solids is very complex, with a range of intrinsic processes producing intensity in final spectra. These processes can include the basic Auger process, initial- and final-states, shake-up/off and Coster-Kronig (CK) processes. Auger Photoelectron Coincidence Spectroscopy (APECS) is a technique to detect the Auger electron only when the 'initial' photoelectron also is detected. By counting those Auger electrons that arrive in coincidence with a photoelectron of certain binding energy, the initial state is uniquely determined, thus controlling the magnitude of various satellites of the Auger spectrum. AxPd1-x is a disordered alloy. XPS spectra indicated that the FWHM of Ag 3d5/2 increases from 0.56 eV in pure Ag to 0.77 eV in Ag0.5Pd0.5. The disorder broadening of the Ag 3d core line in AgPd is due to the spread of local potentials in the atomic cores arising from the effects of charge transfer. In this study, an effect of disorder broadening of the core level photoelectron line on the Ag MVV Auger spectra in random substituted Ag0.5Pd0.5 alloy has been investigated by APECS. Data were collected for the AgM5V45V45 Auger line in coincidence with Ag 3d photoelectron lines. It is shown that the broadening of the AgM5V45V45 line is directly associated with the presence of disorder broadening of the Ag 3d5/2 photoelectron line

  12. Dissociation of OCS by high energy highly charged ion impact

    International Nuclear Information System (INIS)

    OCS is an important molecule with immense biological, chemical and astrophysical significance. Various dissociation channels of OCSq+ (where q = 2 to 4), formed in the interaction of 5 MeV u-1 Si12+ ion beam with neutral OCS, have been studied using recoil-ion momentum spectroscopy. The concerted and/or sequential nature of dissociation is inferred from the shape and slope of the coincidence islands in the 2D coincidence map. It is observed that the C+ + S+ + O channel results from concerted as well as sequential decay of OCS2+. However the other channels originate purely from the concerted process in which the two terminal fragments (oxygen and sulphur) fly back to back and the central carbon fragment is left with negligible momentum. The kinetic energy release (KER) distributions for all the fragmentation channels arising from the dissociation of OCSq+ (where q = 2 to 4) have been measured and compared with the available data in the literature. It is observed that the KER values for complete Coulomb fragmentation channels are much smaller than those of incomplete Coulomb fragmentation cases and the KER increases with the increasing charge states of the parent molecular ions. From the momentum correlation map, we estimated the geometry of the precursor molecular ion undergoing three-body dissociation and inferred that bent dissociative states are involved in most of the fragmentation channels of OCSq+. (authors)

  13. Quantum charged rigid membrane

    Energy Technology Data Exchange (ETDEWEB)

    Cordero, Ruben [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del I.P.N., Unidad Adolfo Lopez Mateos, Edificio 9, 07738 Mexico, D.F. (Mexico); Molgado, Alberto [Unidad Academica de Fisica, Universidad Autonoma de Zacatecas, Zacatecas Zac. (Mexico); Rojas, Efrain, E-mail: cordero@esfm.ipn.mx, E-mail: amolgado@fisica.uaz.edu.mx, E-mail: efrojas@uv.mx [Departamento de Fisica, Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico)

    2011-03-21

    The early Dirac proposal to model the electron as a charged membrane is reviewed. A rigidity term, instead of the natural membrane tension, involving linearly the extrinsic curvature of the worldvolume swept out by the membrane is considered in the action modeling the bubble in the presence of an electromagnetic field. We set up this model as a genuine second-order derivative theory by considering a non-trivial boundary term which plays a relevant part in our formulation. The Lagrangian in question is linear in the bubble acceleration and by means of the Ostrogradski-Hamiltonian approach, we observed that the theory comprises the management of both first- and second-class constraints. We thus show that our second-order approach is robust allowing for a proper quantization. We found an effective quantum potential which permits us to compute bounded states for the system. We comment on the possibility of describing brane world universes by invoking this kind of second-order correction terms.

  14. Quantum charged rigid membrane

    CERN Document Server

    Cordero, Ruben; Rojas, Efrain

    2010-01-01

    The early Dirac proposal to model the electron as a charged membrane is reviewed. A rigidity term, instead of the natural membrane tension, involving linearly the extrinsic curvature of the worldvolume swept out by the membrane is considered in the action modeling the bubble in the presence of an electromagnetic field. We set up this model as a genuine second-order derivative theory by considering a non-trivial boundary term which plays a relevant part in our formulation. The Lagrangian in question is linear in the bubble acceleration and by means of the Ostrogradski-Hamiltonian approach we observed that the theory comprises the management of both first- and second-class constraints. We show thus that our second-order approach is robust allowing for a proper quantization. We found an effective quantum potential which permits to compute bounded states for the system. We comment on the possibility of describing brane world universes by invoking this kind of second-order correction terms.

  15. Space charge dominated beam transport

    International Nuclear Information System (INIS)

    We consider beam transport systems where space charge forces are comparable in strength with the external focusing force. Space charge then plays an important role for beam transmission and emittance growth. We use the envelope model for matching and the generalized field energy equations to study emittance growth. Analytic results are compared with numerical simulation. (orig.)

  16. Looking for milli-charged particles with a new experiment at the LHC

    Science.gov (United States)

    Haas, Andrew; Hill, Christopher S.; Izaguirre, Eder; Yavin, Itay

    2015-06-01

    We propose a new experiment at the Large Hadron Collider (LHC) that offers a powerful and model-independent probe for milli-charged particles. This experiment could be sensitive to charges in the range 10-3 e-10-1 e for masses in the range 0.1-100 GeV, which is the least constrained part of the parameter space for milli-charged particles. This is a new window of opportunity for exploring physics beyond the Standard Model at the LHC. The key new ingredients of the proposal are the identification of an optimal location for the detector and a telescopic/coincidence design that greatly reduces the background.

  17. Holography, charge and baryon asymmetry

    CERN Document Server

    Mongan, T R

    2009-01-01

    The holographic principle indicates the finite number of bits of information available on the particle horizon describes all physics within the horizon. Linking information on the horizon with Standard Model particles requires a holographic model describing constituents (preons) of Standard Model particles in terms of bits of information on the horizon. Standard Model particles have charges 0, 1/3, 2/3 or 1 in units of the electron charge e, so bits in a preon model must be identified with fractional charge. Energy must be transferred to change the state of a bit, and labeling the low energy state of a bit e/3n and the high energy state -e/3n amounts to defining electric charge. Any such charged preon model will produce more protons than anti-protons at the time of baryogenesis and require baryon asymmetry. It will also produce more positrons than electrons, as suggested by astrophysical measurements.

  18. Piston-assisted charge pumping

    CERN Document Server

    Kaur, D; Mourokh, L

    2015-01-01

    We examine charge transport through a system of three sites connected in series in the situation when an oscillating charged piston modulates the energy of the middle site. We show that with an appropriate set of parameters, charge can be transferred against an applied voltage. In this scenario, when the oscillating piston shifts away from the middle site, the energy of the site decreases and it is populated by a charge transferred from the lower energy site. On the other hand, when the piston returns to close proximity, the energy of the middle site increases and it is depopulated by the higher energy site. Thus through this process, the charge is pumped against the potential gradient. Our results can explain the process of proton pumping in one of the mitochondrial enzymes, Complex I. Moreover, this mechanism can be used for electron pumping in semiconductor nanostructures.

  19. Collaborative Mobile Charging and Coverage

    Institute of Scientific and Technical Information of China (English)

    吴杰

    2014-01-01

    Wireless energy charging using mobile vehicles has been a viable research topic recently in the area of wireless networks and mobile computing. This paper gives a short survey of recent research conducted in our research group in the area of collaborative mobile charging. In collaborative mobile charging, multiple mobile chargers work together to accomplish a given set of ob jectives. These ob jectives include charging sensors at different frequencies with a minimum number of mobile chargers and reaching the farthest sensor for a given set of mobile chargers, subject to various constraints, including speed and energy limits of mobile chargers. Through the process of problem formulation, solution construction, and future work extension for problems related to collaborative mobile charging and coverage, we present three principles for good practice in conducting research. These principles can potentially be used for assisting graduate students in selecting a research problem for a term project, which can eventually be expanded to a thesis/dissertation topic.

  20. Shielding of moving line charges

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Youmei; He, Bingyu [Department of Physics, School of Science, Hangzhou Dianzi University, Hangzhou 310018 (China); Yu, Wei [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Yu, M.Y., E-mail: myyu@zju.edu.cn [Institute for Fusion Theory and Simulation and Department of Physics, Zhejiang University, Hangzhou 310027 (China); Institute for Theoretical Physics I, Ruhr University, D-44780 Bochum (Germany)

    2015-07-03

    A charged object moving in plasma can excite plasma waves that inevitably modify its Debye shielding characteristics. When the excited waves propagate sufficiently fast, the shielding can even break down. Here the properties of finite amplitude plasma waves excited by a moving line charge are investigated. It is found that when the speed of the latter is close to but less than the thermal speed of the background plasma electrons, only a localized disturbance in the form of a soliton that moves together with the line charge is excited. That is, the line charge is well shielded even though it is moving at a high speed and has generated a large local electrostatic field. However, for a pair of line charges moving together, such complete shielding behavior could not be found.