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Sample records for beta-gamma coincidence measurements

  1. 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

  2. 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.

  3. Study of a 4{pi}{beta}-{gamma} coincidence system for absolute radionuclide activity measurement using plastic scintillators; Estudo de um sistema de coincidencias 4{pi}{beta}-{gamma} para a medida absoluta de atividade de radionuclideos empregando cintiladores plasticos

    Energy Technology Data Exchange (ETDEWEB)

    Piuvezam Filho, Helio

    2007-07-01

    The present work was intended to study a coincidence system 4{pi}(PS){beta}-{gamma} for absolute activity measurement using plastic scintillators in 4{pi} 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 4{pi}(PS){beta}-{gamma} 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)

  4. 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.

  5. 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

  6. An Optimized Design of Single-Channel Beta-Gamma Coincidence Phoswich Detector by Geant4 Monte Carlo Simulations

    Directory of Open Access Journals (Sweden)

    Weihua Zhang

    2011-01-01

    Full Text Available An optimized single-channel phoswich well detector design has been proposed and assessed in order to improve beta-gamma coincidence measurement sensitivity of xenon radioisotopes. This newly designed phoswich well detector consists of a plastic beta counting cell (BC404 embedded in a CsI(Tl crystal coupled to a photomultiplier tube. The BC404 is configured in a cylindrical pipe shape to minimise light collection deterioration. The CsI(Tl crystal consists of a rectangular part and a semicylindrical scintillation part as a light reflector to increase light gathering. Compared with a PhosWatch detector, the final optimized detector geometry showed 15% improvement in the energy resolution of a 131mXe 129.4 keV conversion electron peak. The predicted beta-gamma coincidence efficiencies of xenon radioisotopes have also been improved accordingly.

  7. Monte Carlo simulation to positron emitter standardized by means of 4{pi}{beta}-{gamma} coincidence system-Application to {sup 22}Na

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Mauro S., E-mail: msdias@ipen.b [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Centro do Reator de Pesquisas - CRPq, C.P. 11049, Pinheiros, 05422-970 Sao Paulo, SP (Brazil); Tongu, Margareth L.O.; Takeda, Mauro N.; Koskinas, Marina F. [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Centro do Reator de Pesquisas - CRPq, C.P. 11049, Pinheiros, 05422-970 Sao Paulo, SP (Brazil)

    2010-07-15

    The present work describes the methodology for predicting the behavior of extrapolation curves obtained in radionuclide standardization by 4{pi}{beta}-{gamma} coincidence measurements, applied to {sup 22}Na, developed at the Laboratorio de Metrologia Nuclear of IPEN-CNEN/SP (LMN-Nuclear Metrology Laboratory). The LMN system consists of a proportional counter (PC) in 4{pi} geometry coupled to a single or a pair of NaI(Tl) scintillation crystals. Two standardization techniques were used: the Sum-Peak and the Nuclear-Peak methods. The theoretical response functions of each detector have been calculated using the MCNPX Monte Carlo code. The code ESQUEMA, developed at LMN, has been used for calculating the extrapolation curve in the 4{pi}{beta}-{gamma} coincidence experiment. Modifications were performed in order to include response tables for positrons and coincidences with annihilation photons. From the calibration results it was possible to extract both the activity value and the positron emission probability per decay. The latter was compared with results from the literature.

  8. 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

  9. Primary 4{pi}{beta}-{gamma} coincidence system for standardization of radionuclides by means of plastic scintillators; Sistema primario por coincidencias 4{pi}{beta}-{gamma} para a padronizacao de radionuclideos empregando cintiladores plasticos

    Energy Technology Data Exchange (ETDEWEB)

    Baccarelli, Aida Maria

    2003-07-01

    The present work describes a 4{pi}({alpha},{beta})-{gamma} coincidence system for absolute measurement of radionuclide activity using a plastic scintillator in 4{pi} 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, {beta}{sup -}, {beta}{sup +} and electron capture have been standardized. The results showed excellent agreement with other conventional primary system which makes use of a 4{pi} 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)

  10. A new approach to beta-gamma coincidence counting. Advance report on the Samar electronic system; Informe preliminar del sistema Samar sistema automatico de medidas absolutas de Radionucleidos

    Energy Technology Data Exchange (ETDEWEB)

    Carlos, J. E. de; Granados, C. E.

    1972-07-01

    In 4{pi} {beta}-{gamma} coincidence measurements, precision on the evaluation of coincidence counting losses is made difficult because of complex overlapping effects between the{beta}--and {gamma}-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.

  11. Sub-millimeter nuclear medical imaging with reduced dose application in positron emission tomography using beta-gamma coincidences

    CERN Document Server

    Lang, C; Parodi, K; Thirolf, P G

    2013-01-01

    Positron emission tomography (PET) permits a functional understanding of the underlying causes of many diseases. Modern whole-body PET systems reach a spatial resolution of 2-6 mm (FWHM). A limitation of this technique occurs from the thermalization and diffusion of the positron before its annihilation, typically within the mm range. We present a nuclear medical imaging technique, able to reach sub-millimeter spatial resolution in 3 dimensions with a reduced effective dose application compared to conventional PET. This 'gamma-PET' technique draws on specific medical isotopes, simultaneously emitting an additional photon accompanying the beta^+ decay. Exploiting the triple coincidence between the positron annihilation and the third photon, it is possible to separate the reconstructed 'true' events from background. In order to characterize the potential of this technique, MC simulations and image reconstructions have been performed. The achievable spatial resolution has been found to reach ca. 0.4 mm (FWHM) in ...

  12. Application of Monte Carlo method in study of the padronization for radionuclides with complex disintegration scheme in 4{pi}{beta}-{gamma} coincidence System; Aplicacao do metodo de Monte Carlo no estudo da padronizacao de radionuclideos com esquema de desintegracao complexos em sistema de coincidencias 4{pi}{beta}-{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Mauro Noriaki

    2006-07-01

    The present work described a new methodology for modelling the behaviour of the activity in a 4{pi}{beta}-{gamma} coincidence system. The detection efficiency for electrons in the proportional counter and gamma radiation in the NaI(Tl) detector was calculated using the Monte Carlo program MCNP4C. Another Monte Carlo code was developed which follows the path in the disintegration scheme from the initial state of the precursor radionuclide, until the ground state of the daughter nucleus. Every step of the disintegration scheme is sorted by random numbers taking into account the probabilities of all {beta}{sup -} branches, electronic capture branches, transitions probabilities and internal conversion coefficients. Once the final state was reached beta, electronic capture events and gamma transitions are accounted for the three spectra: beta, gamma and coincidence variation in the beta efficiency was performed simulating energy cut off or use of absorbers (Collodion). The selected radionuclides for simulation were: {sup 134}Cs, {sup 72}Ga which disintegrate by {beta}{sup -} transition, {sup 133}Ba which disintegrates by electronic capture and {sup 35}S which is a beta pure emitter. For the latter, the Efficiency Tracing technique was simulated. The extrapolation curves obtained by Monte Carlo were filled by the Least Square Method with the experimental points and the results were compared to the Linear Extrapolation method. (author)

  13. Measurement of Time-Dependent CP Asymmetries and Constraints on sin(2 beta+gamma) with Partial Reconstruction of B0->D*-+ pi+- Decays

    CERN Document Server

    Aubert, B; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, Roy; Allison, J; Allmendinger, T; Altenburg, D; Andreotti, M; Angelini, C; Anulli, F; Aston, D; Azzolini, V; Baak, M; Back, J J; Bailey, S; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Barate, R; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Bauer, J M; Beck, T W; Behera, P K; Bellini, F; Benayoun, M; Berger, N; Bernard, D; Berryhill, J W; Best, D; Bettarini, S; Bettoni, D; Bevan, A J; Bhimji, W; Bianchi, F; Biasini, M; Blanc, F; Blaylock, G; Blinov, A E; Blinov, V E; Bloom, P; Bóna, M; Bondioli, M; Bonneaud, G R; Borgland, A W; Bosisio, L; Boutigny, D; Bowerman, D A; Boyarski, A M; Boyd, J T; Bozzi, C; Brandenburg, G; Brandt, T; Brau, J E; Breon, A B; Briand, H; Brochard, F; Brose, J; Brown, C L; Brown, C M; Brown, D; Brown, D N; Bruinsma, M; Brunet, S; Bucci, F; Buchanan, C; Buchmüller, O L; Bugg, W; Bulten, H; Burchat, Patricia R; Button-Shafer, J; Buzzo, A; Côté, D; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Capra, R; Carpinelli, M; Cartaro, C; Cavallo, N; Cavoto, G; Chaisanguanthum, K S; Chao, M; Charles, E; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, E; Chen, J C; Chen, S; Cheng, B; Cheng, C H; Chevalier, N; Christ, S; Cibinetto, G; Clark, P J; Claus, R; Cochran, J; Colecchia, F; Coleman, J P; Contri, R; Convery, M R; Cormack, C M; Cossutti, F; Cottingham, W N; Couderc, F; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L M; Cristinziani, M; Crosetti, G; Çuhadar-Dönszelmann, T; Dahmes, B; Dallapiccola, C; Danielson, N; Dasu, S; Datta, M; Dauncey, P D; David, P; Davier, M; Davis, C L; Day, C T; De Groot, N; De Nardo, Gallieno; Del Buono, L; Della Ricca, G; Di Lodovico, F; Dickopp, M; Dittongo, S; Dong, D; Dorfan, J; Dorigo, A; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Dvoretskii, A; Eckmann, R; Edwards, A J; Egede, U; Eichenbaum, A M; Eigen, G; Eisner, A M; Elmer, P; Elsen, E E; Emery, S; Ernst, J A; Eschenburg, V; Eschrich, I; Fabozzi, F; Faccini, R; Fan, S; Farbin, A; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flack, R L; Flächer, H U; Flood, K T; Ford, K E; Ford, W T; Forster, I J; Forti, F; Fortin, D; Foulkes, S D; Franek, B J; Frey, R; Fritsch, M; Fry, J R; Gabathuler, Erwin; Gaidot, A; Gaillard, J M; Gaillard, J R; Galeazzi, F; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gary, J W; Gaspero, M; Gatto, C; Geddes, N I; Gill, M S; Giorgi, M A; Giraud, P F; Giroux, X; Gladney, L; Glanzman, T; Godang, R; Goetzen, K; Golubev, V B; Gopal, G P; Gowdy, S J; Graham, M; Grancagnolo, S; Green, M G; Greene, M G; Grenier, G J; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Guo, Q H; Hadavand, H K; Hadig, T; Haire, M; Halyo, V; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hart, P A; Hartfiel, B L; Harton, J L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hicheur, A; Hill, E J; Hitlin, D G; Höcker, A; Hodgkinson, M C; Hollar, J J; Honscheid, K; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Igonkina, O; Innes, W R; Ivanchenko, V N; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jawahery, A; Jayatilleke, S M; Jessop, C P; John, M J J; Johnson, J R; Judd, D; Kadel, R W; Kadyk, J; Kagan, H; Karyotakis, Yu; Kass, R; Kelly, M P; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Kitayama, I; Knecht, N S; Koch, H; Kocian, M L; Kofler, R; Kolomensky, Yu G; Koptchev, V B; Kovalskyi, D; Kowalewski, R V; Kozanecki, Witold; Kravchenko, E A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; Lacker, H M; Lae, C K; Lafferty, G D; Lamsa, J; Lanceri, L; Lange, D J; Langenegger, U; Lankford, A J; Laplace, S; Latham, T E; Lau, Y P; Lavin, D; Lazzaro, A; Le Diberder, F R; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, H; Libby, J; Lillard, V; Lista, L; Liu, R; LoSecco, J M; Lo Vetere, M; Lockman, W S; Lombardo, V; London, G W; Long, O; Lou, X C; Lu, A; Lü, C; Luitz, S; Luppi, E; Lusiani, A; Lüth, V; Lutz, A M; Lynch, G; Lynch, H L; Lyon, A J; MacFarlane, D B; Macri, M; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Manfredi, P F; Mangeol, D J J; Marchiori, G; Margoni, M; Marsiske, H; Martínez-Vidal, F; Mattison, T S; Mayer, B; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Meadows, B T; Messner, R; Meyer, T I; Meyer, W T; Miftakov, V; Mihályi, A; Mir, L M; Mohanty, G B; Mohapatra, A K; Mommsen, R K; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morgan, S E; Morganti, M; Morganti, S; Morii, M; Morton, G W; Muheim, F; Müller, D R; Müller-Pfefferkorn, R; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nesom, G; Nicholson, H; Nikolich, M B; Nogowski, R; O'Grady, C P; Ocariz, J; Oddone, P J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Otto, S; Ozcan, V E; Paar, H P; Paick, K; Palano, A; Palombo, F; Pan, Y; Panetta, J; Panvini, R S; Paoloni, E; Paolucci, P; Parry, R J; Passaggio, S; Patel, P M; Patrignani, C; Patteri, P; Payne, D J; Pelizaeus, M; Perazzo, A; Perl, M; Peruzzi, I M; Petersen, B A; Petersen, T C; Petrak, S; Petzold, A; Piatenko, T; Piccolo, D; Piccolo, M; Piemontese, L; Pierini, M; Pioppi, M; Piredda, G; Pivk, M; Plaszczynski, S; Playfer, S; Pompili, A; Poropat, P; Porter, F C; Posocco, M; Potter, C T; Prell, S; Prepost, R; Pripstein, M; Pulliam, T; Purohit, M V; Qi, N D; Rahatlou, S; Rahimi, A M; Rama, M; Rankin, P; Ratcliff, B N; Raven, G; Re, V; Reidy, J; Ricciardi, S; Richman, J D; Ritchie, J L; Rizzo, G; Roat, C; Roberts, D A; Robertson, S H; Robutti, E; Roe, N A; Röthel, W; Ronan, Michael T; Roney, J M; Rong, G; Roodman, A; Roos, L; Rosenberg, E I; Rotondo, M; Rubin, A E; Ryd, A; Saeed, M A; Safai-Tehrani, F; Saleem, M; Salnikov, A A; Salvatore, F; Samuel, A; Sanders, D A; Sandrelli, F; Santroni, A; Saremi, S; Sarti, A; Satpathy, A; Schalk, T; Schindler, R H; Schott, G; Schrenk, S; Schubert, J; Schubert, Klaus R; Schumm, B A; Schune, M H; Schwiening, J; Schwierz, R; Schwitters, R F; Sciacca, C; Sciolla, G; Seiden, A; Sekula, S J; Serednyakov, S I; Sharma, V; Shelkov, V G; Shen, B C; Simani, M C; Simi, G; Simonetto, F; Sinev, N B; Skovpen, Yu I; Sloane, R J; Smith, A J S; Smith, J G; Snoek, H L; Snyder, A; Sobie, R J; Soffer, A; Soha, A; Sokoloff, M D; Solodov, E P; Spaan, B; Spanier, S M; Spradlin, P; Stängle, H; Steinke, M; Stelzer, J; Stoker, D P; Stroili, R; Strom, D; Stugu, B; Su, D; Sullivan, M K; Summers, D J; Sundermann, J E; T'Jampens, S; Tan, P; Tantot, L; Taras, P; Taylor, F; Taylor, G P; Telnov, A V; Teodorescu, L; Ter-Antonian, R; Therin, G; Thiebaux, C; Thiessen, D; Tiozzo, G; Tisserand, V; Toki, W H; Torrence, E; Tosi, S; Touramanis, C; Treadwell, E; Vasileiadis, G; Vasseur, G; Vavra, J; Verderi, M; Verkerke, W; Vitale, L; Voci, C; Voena, C; Vuagnin, G; Wagner, G; Wagner, S R; Wagoner, D E; Waldi, R; Walsh, J; Wang, K; Wang, P; Wappler, F R; Watson, A T; Weaver, M; Weidemann, A W; Weinstein, A J R; Wenzel, W A; Wilden, L; Williams, D C; Williams, J C; Willocq, S; Wilson, F F; Wilson, J R; Wilson, M G; Wilson, R J; Winter, M A; Wisniewski, W J; Wittgen, M; Won, E; Wong, Q K; Wormser, G; Wright, D H; Wright, D M; Wu, J; Wu, S L; Xie, Y; Yamamoto, R K; Yang, S; Yarritu, A K; Ye, S; Yéche, C; Yi, J; Young, C C; Yu, Z; Yumiceva, F X; Yushkov, A N; Zallo, A; Zeng, Q L; Zghiche, A; Zhang, J; Zhang, L; Zhao, H W; Zhu, Y S; Zito, M; De Sangro, R; Del Re, D; La Vaissière, C de

    2004-01-01

    We present a preliminary measurement of the time-dependent CP-violating asymmetry in decays of neutral B mesons to the final states D*-+ pi+- using approximately 178 million BB events recorded by the BaBar experiment at the PEP-II e+e- storage ring. Events containing these decays are selected with a partial reconstruction technique, in which only the high-momentum pi+- from the B decay and the low-momentum pi-+ from the D*-+ decay are used. % We measure the amplitude of the asymmetry to be $-0.041 \\pm 0.016 (stat.) \\pm 0.010 (syst.)$ and determine bounds on $|\\sin(2 \\beta + \\gamma)|$.

  14. 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

  15. Beowulf - Beta-Gamma Detector Calibration Graphical User Interface

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, Justin I.; Schrom, Brian T.; Cooper, Matthew W.; Haas, Derek A.; Hayes, James C.

    2009-09-21

    Pacific Northwest National Laboratory (PNNL) has demonstrated significant advancement in using beta-gamma coincidence detectors to detect a wide range of radioxenon isotopes. To obtain accurate activities with the detector it must be properly calibrated by measuring a series of calibration gas samples. The data is analyzed to create the calibration block used in the International Monitoring System file format. Doing the calibration manually has proven to be tedious and prone to errors, requiring a high degree of expertise. The Beowulf graphical user interface (GUI) is a software application that encompasses several components of the calibration task and generates a calibration block, as well as, a detailed report describing the specific calibration process used. This additional document can be used as a Quality assurance certificate to assist in auditing the calibration. This paper consists of two sections. Section 1 will describe the capabilities of Beowulf and section 2 will be a representative report generated or the 137Cs calibration and quality assurance source.

  16. Beta/gamma test problems for ITS

    International Nuclear Information System (INIS)

    The Integrated Tiger Series of Coupled Electron/Photon Monte Carlo Transport Codes (ITS 3.0, PC Version) was used at Oak Ridge National Laboratory (ORNL) to compare with and extend the experimental findings of the beta/gamma response of selected health physics instruments. In order to assure that ITS gives correct results, several beta/gamma problems have been tested. ITS was used to simulate these problems numerically, and results for each were compared to the problem's experimental or analytical results. ITS successfully predicted the experimental or analytical results of all tested problems within the statistical uncertainty inherent in the Monte Carlo method

  17. 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)

  18. Beta-gamma discriminator circuit

    International Nuclear Information System (INIS)

    The major difficulty encountered in the determination of beta-ray dose in field conditions is generally the presence of a relatively high gamma-ray component. Conventional dosimetry instruments use a shield on the detector to estimate the gamma-ray component in comparison with the beta-ray component. More accurate dosimetry information can be obtained from the measured beta spectrum itself. At Los Alamos, a detector and discriminator circuit suitable for use in a portable spectrometer have been developed. This instrument will discriminate between gammas and betas in a mixed field. The portable package includes a 256-channel MCA which can be programmed to give a variety of outputs, including a spectral display, and may be programmed to read dose directly

  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. 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)

  1. Simultaneous beta/gamma digital spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.

    A state-of-the-art radiation detection system for simultaneous spectroscopy of beta-particles and gamma-rays has been developed. The system utilizes a triple-layer phoswich detector and a customized Digital Pulse Processor (DPP) built in our laboratory. The DPP board was designed to digitally capture the analog signal pulses and, following several digital preprocessing steps, transfer valid pulses to the host computer for further digital processing. A MATLAB algorithm was developed to digitally discriminate beta and gamma events and reconstruct separate beta and gamma-ray energy spectra with minimum crosstalk. The spectrometer proved to be an effective tool for recording separate beta and gamma-ray spectra from mixed radiation fields. The system as a beta-gamma spectrometer will have broad-ranging applications in nuclear non-proliferation, radioactive waste management, worker safety, systems reliability, dose assessment, and risk analysis.

  2. 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

  3. 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.

  4. 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.)

  5. Microstructures of duplex (beta + gamma) silver-tin alloys.

    Science.gov (United States)

    Abbott, J R; Miller, D R; Netherway, D J

    1985-05-01

    The microstructures of (beta + gamma) silver-tin alloys are especially influenced by both homogenization temperature and subsequent heat treatment. When the alloy is cooled from homogenization temperatures above approximately 200 degrees C, lenticular regions of the ordered orthorhombic gamma phase precipitate from within the disordered h.c.p. beta phase on three structurally equivalent planes, (1210), (1120), and (2110), to form a Widmanstatten structure. When the duplex alloys were homogenized at temperatures below approximately 200 degrees C, where the beta/(beta + gamma) phase boundary is vertical, these structures were not observed. PMID:3858310

  6. 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.

  7. 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.

  8. Evidence for the virtual beta-gamma transition in 59Ni

    CERN Document Server

    Pfützner, M; Żylicz, J

    2015-01-01

    A novel theory of radiative electron capture in second forbidden non-unique transition, is applied to reanalyze experimental data obtained previously for the decay of 59Ni. The measured gamma spectrum is shown to be distorted at the high-energy end, presenting the first direct evidence for the virtual beta-gamma transition through the excited state in 59Co. The complete theoretical predictions, including both the direct and the virtual decay channels, as well as the interference between them, reproduce very well the experimental spectrum. The virtual nuclear component amounts to about 4% of the total gamma intensity.

  9. 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.)

  10. 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).

  11. 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.

  12. Effects of beta/gamma radiation on nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-07-01

    A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted {beta}-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of {beta}/{gamma} radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author)

  13. 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

  14. Decontamination Experiments on Intact Pig Skin Contaminated with Beta-Gamma- Emitting Nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Edvardsson, K.A.; Hagsgaard, S. [AB Atomenergi, Nykoeping (Sweden); Swensson, A. [Dept. of Occupational Medicine, Karolinska Sjukhuset, Stockholm (Sweden)

    1966-11-15

    A number of decontamination experiments have been performed on intact pig skin. In most of the experiments NaI-131 in water solution has been utilized because this nuclide is widely used within the Studsvik research establishment, is easy to detect and relatively harmless, and is practical to use in these experiments. Among the {beta} {gamma}-nuclides studied 1-131 has furthermore proved to be the one most difficult to remove from the skin. The following conclusions and recommendations regarding the decontamination of skin are therefore valid primarily for iodine in the form of Nal, but are probably also applicable to many other {beta} {gamma}-nuclides. a) A prolonged interval between contamination and decontamination has a negative effect on the result of the decontamination. Therefore start decontamination as soon as possible after the contamination. b) Soap and water has proved to be the most suitable decontamination agent. A number of other agents have appeared to be harmful to the skin. Therefore, first of all use only soap and water in connection with gentle rubbing. c) No clear connection between the temperature of the water for washing and the result of the decontamination has been demonstrated. d) Skin not degreased before the contamination seems to be somewhat easier to decontaminate than degreased skin, particularly if the activity has been on the skin for a long time. Therefore do not remove the sebum of the skin when engaged on radioactive work involving contamination risks. e) Irrigation of the contaminated surface with a solution containing the corresponding inactive ions or ordinary water in large quantities may considerably decrease the skin contamination. f) In radioactive work of long duration involving high risks of contamination prophylactic measures in the form of a protective substance ('invisible glove'), type Kerodex, may make decontamination easier.

  15. 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)

  16. 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.

  17. Beta-gamma system, pure spinors and Hilbert series of arc spaces

    OpenAIRE

    Bhamidipati, Chandrasekhar; Ray, Koushik

    2014-01-01

    Algorithms are presented for calculating the partition function of constrained beta-gamma systems in terms of the generating functions of the individual fields of the theory, the latter obtained as the Hilbert series of the arc space of the algebraic variety defined by the constraint. Examples of a beta-gamma system on a complex surface with an $A_1$ singularity and pure spinors are worked out and compared with existing results.

  18. The assay of encapsulated beta-gamma emitting waste: feasibility study

    International Nuclear Information System (INIS)

    This report contains a discussion of the techniques and instrumentation available for the determination of Beta-Gamma emitting radionuclides in encapsulated radioactive waste. Where applicable, consideration has been given to the practical difficulties associated with the assay of certain waste forms. The levels of detection have been estimated but further work is required in this and other areas. A suggestion is made for incorporating the beta-gamma assay in the same facility as an alpha assay. (author)

  19. Low-level multicounter {beta}/{gamma} systems with external guards in surface and shallow underground laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Theodorsson, P. [Iceland Univ. (Iceland). Science Inst.

    1997-03-01

    When weak samples are measured it is important that they can be given ample counting time in order to obtain satisfactory accuracy and that the background count rate can be checked well. This calls for a high counting capacity, which multidetectors can bring us. I will discuss development possibilities of low-level {beta}/{gamma} multidetector systems with an external anticosmic shield that will in many cases be operated in underground laboratories. These simple and low-cost system can frequently help us in increasing the number of detectors. Three concepts are combined in these systems: (1) multidetectors, (2) an external anticosmic (or guard) detector arrangement and (3) overburden shielding. (orig.)

  20. 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)

  1. 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

  2. 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)

  3. 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.

  4. 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.

  5. 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)

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. Gram-scale Plutonium Samples Measured by Experimental Device of Four Detectors Well-type Fast Neutron Coincidence Measurement

    Institute of Scientific and Technical Information of China (English)

    LIU; Guo-rong; LIANG; Qing-lei; LI; Jing-huai; LI; An-li

    2013-01-01

    Experimental device of four detectors well-type fast neutron coincidence measurement(see Fig.1)consists of four?127 mm×50.8 mm BC501A liquid scintillation detectors,DC271A digitizer and other circuits.Application program simultaneously acquires the waveform of each pulse output from each detector,and identifies each pulse from neutron or?particle by offline model,and gets their arrival timing.

  12. 75 FR 4877 - In the Matter of Beta Gamma Nuclear Radiology; Confirmatory Order Modifying License (Effective...

    Science.gov (United States)

    2010-01-29

    ... rule (72 FR 49139, August 28, 2007). The E-Filing process requires participants to submit and serve all... Gamma Nuclear Radiology; Confirmatory Order Modifying License (Effective Immediately) I Beta Gamma Nuclear Radiology (BGNR) (Licensee) is the holder of medical License No. 52-25542-01, issued by the...

  13. Weighted $\\beta\\gamma$-summability of fuzzy functions of order $\\theta$

    OpenAIRE

    Ojha, Sarita; Srivastava, P. D.

    2016-01-01

    The concept of weighted $\\beta\\gamma$ - summability of order $\\theta$ in case of fuzzy functions is introduced and classified into ordinary and absolute sense. Several inclusion relations among the sets are investigated. Also we have found some suitable conditions to get its relation with the generalized statistical convergence. Finally we have proved a generalized version of Tauberian theorem.

  14. Generalized Bessel transform of $(\\beta, \\gamma)$-generalized Bessel Lipschitz functions

    OpenAIRE

    DAHER, Radouan; El Hamma, Mohamed

    2015-01-01

    In this paper, we prove an analog of Younis’s theorem 5.2 in~[4] for the generalized Fourier-Bessel transform on the Half line for functions satisfying the $(\\beta, \\gamma)$-generalized Bessel Lipschitz condition in the space $\\mathrm{L}^{2}_{\\alpha,n}$.

  15. 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.

  16. 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.)

  17. 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.

  18. 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.

  19. Retrieval of ozone column content from airborne Sun photometer measurements during SOLVE II: comparison with coincident satellite and aircraft measurements

    Directory of Open Access Journals (Sweden)

    J. M. Livingston

    2005-01-01

    Full Text Available During the 2003 SAGE (Stratospheric Aerosol and Gas Experiment III Ozone Loss and Validation Experiment (SOLVE II, the fourteen-channel NASA Ames Airborne Tracking Sunphotometer (AATS-14 was mounted on the NASA DC-8 aircraft and measured spectra of total and aerosol optical depth (TOD and AOD during the sunlit portions of eight science flights. Values of ozone column content above the aircraft have been derived from the AATS-14 measurements by using a linear least squares method that exploits the differential ozone absorption in the seven AATS-14 channels located within the Chappuis band. We compare AATS-14 columnar ozone retrievals with temporally and spatially near-coincident measurements acquired by the SAGE III and the Polar Ozone and Aerosol Measurement (POAM III satellite sensors during four solar occultation events observed by each satellite. RMS differences are 19 DU (6% of the AATS value for AATS-SAGE and 10 DU (3% of the AATS value for AATS-POAM. In these checks of consistency between AATS-14 and SAGE III or POAM III ozone results, the AATS-14 analyses use airmass factors derived from the relative vertical profiles of ozone and aerosol extinction obtained by SAGE III or POAM III.

    We also compare AATS-14 ozone retrievals for measurements obtained during three DC-8 flights that included extended horizontal transects with total column ozone data acquired by the Total Ozone Mapping Spectrometer (TOMS and the Global Ozone Monitoring Experiment (GOME satellite sensors. To enable these comparisons, the amount of ozone in the column below the aircraft is estimated either by assuming a climatological model or by combining SAGE and/or POAM data with high resolution in-situ ozone measurements acquired by the NASA Langley Research Center chemiluminescent ozone sensor, FASTOZ, during the aircraft vertical profile at the start or end of each flight. Resultant total column ozone values agree with corresponding TOMS and GOME measurements to

  20. 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

  1. Portable alpha, beta, gamma, x and neutron radiation monitor

    International Nuclear Information System (INIS)

    Full text: Here below there is short information about new instrument developed in SPE ATOMTEX, which will be produced at the close of the year. The instrument consists of the main unit, including built-in detector Nal (Tl) of diameter 25x40 mm and photomultiplier tube, analog devices (amplifier, multichannel pulse-height analyzer of 256 channels, high-voltage power supply, LED stabilization scheme of measuring path) and digital devices (microprocessor for data processing, control and storage, liquid crystal display, interface). The main unit operates also as processing and indication device of connected external detection units: α, β-radiation contamination scintillator detection unit; x, γ-radiation detection unit with silicon detector to measure equivalent dose and equivalent dose rate and n-radiation detection unit with proportional 3He-counters. Because of scintillator detector Nal (Tl), the main unit, operating in counting mode, searches and detects effectively x- and gamma-radiation sources with the energy from 30 keV to 3 MeV. The point source of 137Cs of 50 kBq is detected at the distance of 10 cm for 2s. Ambient equivalent dose and equivalent dose rate are measured with this detector using the method of instrumental spectrum transformation into dose. In this case the energy range is from 40 keV to 3 meV. Energy relationship of readings do not exceed ± 15% with respect to the energy of 0,662 MeV. The range of ambient equivalent dose rate measurement is from 0,05 μSv/h to 0,05 mSv/h, with response time of 20 s at background change from 0,05 μSv/h to 0,1 μSv/h. The main unit operates also as selective express-radiometer, which could evaluate sample activity by single gamma-line. Measurement geometry is Marinelly's vessel of 0,5 l. The lower limit of measuring activity is 300 Bq/l without lead shield and 20 Bq/l with it with measurement time of 10 min. The unit weighs not more than 0,9 kg. External detection units connect to interface socket by turns

  2. 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.

  3. Alpha and Conversion Electron Spectroscopy of 238, 239Pu and 241Am and Alpha-Conversion Electron Coincidence Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Dion, Michael P.; Miller, Brian W.; Warren, Glen A.

    2016-05-17

    A technique to determine the isotopics of a mixed actinide sample has been proposed by measuring the coincidence of the alpha particle during radioactive decay with the conversion electron (or Auger) emitted during the relaxation of the daughter isotope. This presents a unique signature to allow the deconvolution of isotopes that possess overlapping alpha particle energy. The work presented here are results of conversion electron spectroscopy of 241Am, 238Pu and 239Pu using a dual-stage peltier-cooled 25 mm2 silicon drift detector. A passivated ion implanted planar silicon detector provided measurements of alpha spectroscopy. The conversion electron spectra were evaluated from 20–55 keV based on fits to the dominant conversion electron emissions, which allowed the relative conversion electron emission intensities to be determined. These measurements provide crucial singles spectral information to aid in the coincident measurement approach.

  4. Error-control and processes optimization of (223/224)Ra measurement using Delayed Coincidence Counter (RaDeCC).

    Science.gov (United States)

    Xiaoqing, Cheng; Lixin, Yi; Lingling, Liu; Guoqiang, Tang; Zhidong, Wang

    2015-11-01

    RaDeCC has proved to be a precise and standard way to measure (224)Ra and (223)Ra in water samples and successfully made radium a tracer of several environmental processes. In this paper, the relative errors of (224)Ra and (223)Ra measurement in water samples via a Radium Delayed Coincidence Count system are analyzed through performing coincidence correction calculations and error propagation. The calculated relative errors range of 2.6% ∼ 10.6% for (224)Ra and 9.6% ∼ 14.2% for (223)Ra. For different radium activities, effects of decay days and counting time on final radium relative errors are evaluated and the results show that these relative errors can decrease by adjusting the two measurement factors. Finally, to minimize propagated errors in Radium activity, a set of optimized RaDeCC measurement parameters are proposed. PMID:26233651

  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. 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)

  7. 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.

  8. A new method of time difference measurement: The time difference method by dual phase coincidence points detection

    Science.gov (United States)

    Zhou, Wei

    1993-01-01

    In the high accurate measurement of periodic signals, the greatest common factor frequency and its characteristics have special functions. A method of time difference measurement - the time difference method by dual 'phase coincidence points' detection is described. This method utilizes the characteristics of the greatest common factor frequency to measure time or phase difference between periodic signals. It can suit a very wide frequency range. Measurement precision and potential accuracy of several picoseconds were demonstrated with this new method. The instrument based on this method is very simple, and the demand for the common oscillator is low. This method and instrument can be used widely.

  9. Alpha and conversion electron spectroscopy of 238,239Pu and 241Am and alpha-conversion electron coincidence measurements

    Science.gov (United States)

    Dion, Michael P.; Miller, Brian W.; Warren, Glen A.

    2016-09-01

    A technique to determine the isotopic constituents of a mixed actinide sample has been proposed by a coincident alpha-conversion electron measurement. This presents a unique signature to allow the unfolding of isotopes that possess overlapping alpha particle energy and reduce backgrounds of an unseparated sample. The work presented here are results of conversion electron spectroscopy of 241Am, 238Pu and 239Pu using a dual-stage peltier-cooled 25 mm2 silicon drift detector and alpha spectroscopy with a passivated ion implanted planar silicon detector. The conversion electron spectra were evaluated from 20-55 keV based on fits to the dominant conversion electron emissions, which allowed the relative conversion electron emission intensities to be determined. These measurements provide crucial singles spectral information and calibration to aid in the coincident measurement approach. Furthermore, an alpha-conversion electron spectrometer was assembled using the silicon based detectors described and results of a coincident spectrum analysis is reported for 241Am.

  10. 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})

  11. Behaviour of {alpha}-, {beta}-, {gamma}-, and {delta}-hexachlorocyclohexane in the soil-plant system of a contaminated site

    Energy Technology Data Exchange (ETDEWEB)

    Calvelo Pereira, R. [Departamento de Edafoloxia e Quimica Agricola, Facultade de Bioloxia, Universidade de Santiago de Compostela, 15782-Santiago de Compostela (Spain)]. E-mail: edrobert@usc.es; Camps-Arbestain, M. [Departamento de Edafoloxia e Quimica Agricola, Facultade de Bioloxia, Universidade de Santiago de Compostela, 15782-Santiago de Compostela (Spain); Rodriguez Garrido, B. [Departamento de Edafoloxia e Quimica Agricola, Facultade de Bioloxia, Universidade de Santiago de Compostela, 15782-Santiago de Compostela (Spain); Macias, F. [Departamento de Edafoloxia e Quimica Agricola, Facultade de Bioloxia, Universidade de Santiago de Compostela, 15782-Santiago de Compostela (Spain); Monterroso, C. [Departamento de Edafoloxia e Quimica Agricola, Facultade de Bioloxia, Universidade de Santiago de Compostela, 15782-Santiago de Compostela (Spain)

    2006-11-15

    The behaviour of the organochlorine pesticide hexachlorocyclohexane (HCH) is investigated. The concentrations of {alpha}-, {beta}-, {gamma}-, and {delta}-HCH isomers were measured in soils, rhizosphere and vegetation in a contaminated area in Galicia (NW Spain). The total concentration of HCH in soils reached values close to 20 000 mg kg{sup -1}. The plants analysed (Avena sativa L., Chenopodium spp., Solanum nigrum L., Cytisus striatus (Hill) Roth, and Vicia sativa L.) accumulated HCH, especially the {beta}-HCH isomer, in their tissues. The most likely mechanisms of HCH accumulation in plants were sorption of soil HCH on roots and sorption of volatilized HCH on aerial plant tissues. The concentrations of HCH obtained from the bulk and rhizosphere soils of selected plant species suggest that roots tend to reduce levels of the HCH isomers in the rhizosphere. The results reflect the importance of vegetation in the distribution of organochlorine compounds in the soil-plant system. - This paper describes the soil-plant relationship of hexachlorocyclohexane isomers in a contaminated site, with special focus on the rhizosphere effect.

  12. Response-surface models for deterministic effects of localized irradiation of the skin by discrete {beta}/{gamma} -emitting sources

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.

    1995-12-01

    Individuals who work at nuclear reactor facilities can be at risk for deterministic effects in the skin from exposure to discrete {Beta}- and {gamma}-emitting ({Beta}{gamma}E) sources (e.g., {Beta}{gamma}E hot particles) on the skin or clothing. Deterministic effects are non-cancer effects that have a threshold and increase in severity as dose increases (e.g., ulcer in skin). Hot {Beta}{gamma}E particles are {sup 60}Co- or nuclear fuel-derived particles with diameters > 10 {mu}m and < 3 mm and contain at least 3.7 kBq (0.1 {mu}Ci) of radioactivity. For such {Beta}{gamma}E sources on the skin, it is the beta component of the dose that is most important. To develop exposure limitation systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for evaluating the risk of deterministic effects of localized {Beta} irradiation of the skin. The purpose of this study was to develop dose-rate and irradiated-area dependent, response-surface models for evaluating risks of significant deterministic effects of localized irradiation of the skin by discrete {Beta}{gamma}E sources and to use modeling results to recommend approaches to limiting occupational exposure to such sources. The significance of the research results as follows: (1) response-surface models are now available for evaluating the risk of specific deterministic effects of localized irradiation of the skin; (2) modeling results have been used to recommend approaches to limiting occupational exposure of workers to {Beta} radiation from {Beta}{gamma}E sources on the skin or on clothing; and (3) the generic irradiated-volume, weighting-factor approach to limiting exposure can be applied to other organs including the eye, the ear, and organs of the respiratory or gastrointestinal tract and can be used for both deterministic and stochastic effects.

  13. Validation of ACE-FTS satellite data in the upper troposphere/lower stratosphere (UTLS using non-coincident measurements

    Directory of Open Access Journals (Sweden)

    M. I. Hegglin

    2007-09-01

    Full Text Available CO, O3, and H2O data in the upper troposphere/lower stratosphere (UTLS measured by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS on Canada's SCISAT-1 satellite are validated using aircraft measurements. In the UTLS, validation of chemical trace gas measurements is a challenging task due to small-scale variability in the tracer fields, strong gradients of the tracers across the tropopause, and scarcity of measurements suitable for validation purposes. Two alternative methods for the validation of the satellite data are introduced, which avoid the usual need for coincident measurements: tracer-tracer correlations, and vertical profiles relative to the tropopause height. Both largely reduce geophysical variability and thereby provide an "instantaneous climatology", allowing measurement comparison with non-coincident data which yields information about the precision, and a statistically meaningful error-assessment of the ACE-FTS satellite data. We found that the ACE-FTS CO and lower stratospheric O3 agree with the aircraft measurements within ±10% and ±5%, respectively. The ACE-FTS O3 in the UT exhibits a high bias of up to 40%. H2O indicates a low bias with relative differences of around 20% in the LS and 40% in the UT, respectively. When taking into account the smearing effect of the vertically limited spacing between measurements of the ACE-FTS instrument, the errors decrease by 5–15% around the tropopause. The ACE-FTS instrument hence offers unprecedented precision and vertical resolution in the UTLS, that will allow a new global perspective on UTLS tracer distributions.

  14. 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)

  15. Time-Dependent Coincidence Method to Measure Plutonium Mass and Multiplication

    International Nuclear Information System (INIS)

    Future nuclear disarmament agreements between nations may require technical measures to ascertain each participating nation's adherence to the agreement. Almost certainly, measurement technologies and analytical methods will have to be developed by the participating nations jointly. In this way each participant has both confidence in the technology's efficacy and trust in its implementation. With the support of the National Nuclear Security Administration's Office of Nonproliferation Policy (NNSA NA-241), the Oak Ridge National Laboratory (ORNL) and the All-Russian Scientific Research Institute of Experimental Physics (VNIIEF) have taken first steps to jointly develop and implement a radiation measurement technique to inspect plutonium. In June and July 2000, personnel from ORNL and VNIIEF performed joint experiments on unclassified plutonium metal ((delta)-phase, 1.77%-(sup 240)Pu) spherical shells at VNIIEF facilities in Sarov, Russia[1,2]. The measurements were performed using the Nuclear Materials Identification System (NMIS). The subsequent analysis demonstrates how NMIS can be applied to passively measure the mass and multiplication of plutonium spherical shells

  16. Coincident measurements of prompt fission γ rays and fission fragments at DANCE

    Science.gov (United States)

    Walker, C. L.; Baramsai, B.; Jandel, M.; Rusev, G.; Couture, A.; Mosby, S.; Ullmann, J.; Kawano, T.; Stetcu, I.; Talou, P.

    2015-10-01

    Modern statistical approaches to modeling fission involve the calculation of not only average quantities but also fully correlated distributions of all fission products. Applications such as those involving the detection of special nuclear materials also rely on fully correlated data of fission products. Experimental measurements of correlated data are thus critical to the validation of theory and the development of important applications. The goal of this experiment was to measure properties of prompt fission gamma-ray emission as a function of fission fragments' total kinetic energy in the spontaneous fission of 252Cf. The measurement was carried out at the Detector for Advanced Neutron Capture Experiments (DANCE), a 4 π γ-ray calorimeter. A prototype design consisting of two silicon detectors was installed in the center of DANCE, allowing simultaneous measurement of fission fragments and γ rays. Effort has been taken to simulate fragment kinetic energy losses as well as γ-ray attenuation in DANCE using such tools as GEANT4 and SRIM. Theoretical predictions generated by the code CGMF were also incorporated as input for these simulations. Results from the experiment and simulations will be presented, along with plans for future measurements.

  17. The Coincidence Tracker: Electronic Equipment for a Time-of-Flight Wind-Speed Measurement System

    DEFF Research Database (Denmark)

    Fog, Christian

    1982-01-01

    The electronic part of a laser-beam measuring system for wind velocity is described. Pulses of light scattered from aerosols are treated, first in a pair of adaptive filters, then in a tracker that calculates the wind velocity on-line while applying some knowledge about the velocity to be expected...

  18. Peculiarities of the clinical course of radiation sickness and organizational decisions for radiation accidents with beta-gamma sources

    International Nuclear Information System (INIS)

    The analysis of a number of recent large scale accidents involving beta-gamma sources in the last 40 years, such as those of the Marshall Islands (1954); Windscale, UK (1957); Chernobyl, USSR (1986) and Goiania, Brazil (1987) demonstrates the predominance and importance of health and social impacts. (author)

  19. Random coincidences during in-beam PET measurements at microbunched therapeutic ion beams

    Science.gov (United States)

    Parodi, K.; Crespo, P.; Eickhoff, H.; Haberer, T.; Pawelke, J.; Schardt, D.; Enghardt, W.

    2005-06-01

    At the experimental carbon ion tumour therapy facility at GSI Darmstadt, in-beam positron emission tomography (PET) is used to monitor the dose delivery precision. A dual head positron camera has been assembled from commercial detector components in order to measure the β+-activity, induced by the irradiation, simultaneously to the dose application. Despite the positive clinical impact, the image quality is limited by the low counting statistics, orders of magnitude below that in standard PET applications to nuclear medicine. This paper investigates the origin for the noisy acquisition during particle extraction from the synchrotron of GSI. The results demonstrate the failure of standard random correction techniques due to a γ-ray background correlated in time with the carbon ion beam microstructure. This prevents the use of data acquired during beam extraction for imaging. The loss of counting statistics is expected to rise further at the future hospital-based facility at Heidelberg, due to a more efficient utilisation of the accelerator resulting in shorter beam pauses and a reduced treatment time. In this respect, this paper provides the basis for a new data acquisition concept tailored to the unconventional application of in-beam PET imaging to therapy monitoring at radiofrequency pulsed radiation sources.

  20. Study of Rare B-Meson Decays Related to the CPObservable sin(2beta+gamma) at the BABAR Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Orimoto, Toyoko Jennifer

    2007-08-21

    This study reports the observation of the decays B{sup 0}{yields}D{sup (*)+}{sub S}{pi}{sup -} and B{sup 0}{yields}D{sup (*)-}K{sup +} in a sample of 230 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring, located at the Stanford Linear Accelerator Center. The branching fractions {beta}(B{sup 0} {yields} D{sup +}{sub S}{pi}{sup -}) = (1.3 {+-} 0.3 (stat) {+-} 0.2 (syst)) x 10{sup -5}, {beta}(B{sup 0} {yields} D{sup +}{sub S}K{sup +}) = (2.5 {+-} 0.4 (stat) {+-} 0.4 (syst)) x 10{sup -5}, {beta}(B{sup 0}{yields}D{sup (*)+}{sub S}{pi}{sup -}) = (2.8 {+-} 0.6 (stat) {+-} 0.5 (syst)) x 10{sup -5}, and {beta}(B{sup 0}{yields}D{sup (*)-}K{sup +}) = (2.0 {+-} 0.5 (stat) {+-} 0.4 (syst)) x 10{sup -5} are measured. The significance of the measurements to differ from zero are 5, 9, 6, and 5 standard deviations, respectively. This is a first observation of the decaysB{sup 0}{yields}D{sup (*)+}{sub S}{pi}{sup -} and B{sup 0}{yields}D{sup (*)-}K{sup +}. These results may potentially be useful in determining the CP asymmetry parameter sin(2{beta} + {gamma}) in the decays B{sup 0}{yields}D{sup (*)+}{sub S}{pi}{sup -}.

  1. 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.

  2. Line C17: alpha and medium-level beta-gamma laboratory pilot facility

    Energy Technology Data Exchange (ETDEWEB)

    Calor, J.N.; Mauborgne, B.; Montuir, M. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification (DRRV), 30 - Marcoule (France)

    2000-07-01

    The Process Development Laboratory (LDP) uses the ATALANTE C17 line for integral testing in order to develop and validate spent fuel reprocessing methods and for overall qualification of calculation codes. Line C 17 comprises shielded cells and glove boxes, equipped with centrifugal extractors and laboratory-scale mixer-settlers to test liquid-liquid extraction processes in an alpha and medium-level beta-gamma environment. The high reliability and precision of the process instrumentation and control system allow full control of operating parameters and comprehensive operating data recording, meeting the experimentation quality requirements necessary for qualifying calculation codes. Direct online spectrophotometric analysis at various points in the process provides real-time concentration data for vital elements, some of which are difficult to analyze offline because of their poor chemical stability. Online analyses, supplemented when necessary by gamma spectrometry, provide valuable process control input for reaching stabilized operating conditions. Fifteen radioactive test campaigns have been successfully completed since line C 17 was commissioned in June 1995. (authors)

  3. 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

  4. Data-model comparison search analysis of coincident PBO Balmer α, EURD Lyman β geocoronal measurements from March 2000

    Science.gov (United States)

    Bishop, J.; Mierkiewicz, E. J.; Roesler, F. L.; Gómez, J. F.; Morales, C.

    2004-05-01

    Recent Lyman series and Balmer series airglow measurements provide a fresh opportunity to investigate the density distribution and variability of atomic hydrogen in the upper atmosphere. Dedicated nightside Balmer α Fabry-Perot spectrometer measurements at the Pine Bluff Observatory (PBO), University of Wisconsin-Madison, have been acquired since late 1999 taking advantage of several technological advances. Extreme ultraviolet spectral radiance measurements by the Espectrógrafo Ultravioleta extremo para la Radiación Difusa (EURD) instrument on the Spanish MINISAT-1 satellite from October 1997 to December 2001 provide extensive sets of geocoronal Lyman β, Lyman γ and He 584 Å emission intensities. In this paper, coincident EURD Lyman β and PBO Balmer α radiance measurements from the early March 2000 new moon period are presented. In addition to serving as examples of the data sets now available, the data volume poses an analysis challenge not faced in prior geocoronal studies. A data-model comparison search procedure employing resonance radiation transport results for extensive sets of parametric density distribution models is being developed for use in analyses of multiple large data sets; this is described, and example results for the PBO and EURD March 2000 data sets are presented. The tightness of the constraints obtained for the solar line-center Lyman β irradiance and the atomic hydrogen column abundance is somewhat surprising, given the crudeness of the parameter binning in the search procedure and the fact that a small number of recognized corrections remain to be made to each data set.

  5. Cyclic oxidation behavior of beta+gamma overlay coatings on gamma and gamma+gamma-prime alloys

    Science.gov (United States)

    Nesbitt, J. A.; Pilsner, B. H.; Carol, L. A.; Heckel, R. W.

    1984-01-01

    Detailed experimental studies of the cyclic oxidation behavior of low-pressure plasma sprayed beta+gamma coasting on gamma-phase Ni-Cr-Al alloys have shown the correlation of weight change, oxide type, and Cr and Al concentration-distance profiles as a function of oxidation time. Of special interest was the transition to breakway oxidation due to the loss of the Al flux to the oxide and the failure of the coated alloy to form an Al2O3-rich oxide scale. The experimental results on beta+gamma/gamma coating systems were used as the basis of a numerical model (ternary, semi-infinite, finite-difference analysis) which accurately predicted changes in Cr and Al concentration-distance profiles. The model was used to study parameters critical to enhancing the life of coatings which fail by a combination of Al loss in forming the oxide scale and Al loss via interdiffusion with the substrate alloy. Comparisons of beta+gamma/gamma coating behavior are made to the oxidation of coated gamma+gamma-prime substrates, both ternary Ni-Cr-Al alloys and Mar-M 247-type alloys.

  6. The Generalized Centroid Difference method for lifetime measurements via γ-γ coincidences using large fast-timing arrays

    Directory of Open Access Journals (Sweden)

    Régis J.-M.

    2015-01-01

    Full Text Available A novel method for direct electronic “fast-timing” lifetime measurements of nuclear excited states via γ-γ coincidences using an array equipped with N very fast high-resolution LaBr3(Ce scintillator detectors is presented. The generalized centroid difference method provides two independent “start” and “stop” time spectra obtained without any correction by a superposition of the N(N – 1/2 calibrated γ-γ time difference spectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forward and reverse gating of a specific γ-γ cascade and the centroid difference as the time shift between the centroids of the two time spectra provides a picosecond-sensitive mirror-symmetric observable of the set-up. The energydependent mean prompt response difference between the start and stop events is calibrated and used as a single correction for lifetime determination. These combined fast-timing array mean γ-γ zero-time responses can be determined for 40 keV < Eγ < 1.4 MeV with a precision better than 10 ps using a 152Eu γ-ray source. The new method is described with examples of (n,γ and (n,f,γ experiments performed at the intense cold-neutron beam facility PF1B of the Institut Laue-Langevin in Grenoble, France, using 16 LaBr3(Ce detectors within the EXILL&FATIMA campaign in 2013. The results are discussed with respect to possible systematic errors induced by background contributions.

  7. Assessing spaceborne lidar detection and characterization of aerosols near clouds using coincident airborne lidar and other measurements

    Science.gov (United States)

    Kacenelenbogen, M. S.; Redemann, J.; Russell, P. B.; Vaughan, M.; Omar, A. H.; Burton, S. P.; Rogers, R.; Ferrare, R. A.; Hostetler, C. A.; Hair, J. W.

    2011-12-01

    The objectives are to 1) evaluate potential shortcomings in the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) aerosol height detection concerning specific biomass burning smoke events informed by airborne High Spectral Resolution Lidar (HSRL) in different cloud environments and 2) study the lidar-derived atmospheric parameters in the vicinity of clouds for the cases where smoke is within or above clouds. In the case of light absorbing aerosols like biomass burning smoke, studies show that the greater the cloud cover below the aerosols, the more likely the aerosols are to heat the planet. An accurate aerosol height assumption is also crucial to a correct retrieval of aerosol chemical composition from passive space-based measurements (through the Single Scattering Albedo (SSA) and aerosol absorption coefficient, as exemplified by aerosol retrievals using the passive Ozone Monitoring Instrument (OMI)). Strong smoke events are recognized as very difficult to quantify from space using passive (MODIS, OMI etc...) or active (CALIOP) satellite sensors for different reasons. This study is performed through (i) the selection of smoke events with coincident CALIOP and airborne HSRL aerosol observations, with smoke presence determined according to the HSRL aerosol classification data, (ii) the order of such events by range of HSRL aerosol optical depth, total color ratio and depolarization ratio (the latter two informing on the size and shape of the particles) and the evaluation of CALIOP's detection, classification and retrieval performance for each event, (iii) the study of the HSRL (or CALIOP when available) atmospheric parameters (total color ratio, volume depolarization ratio, mean attenuated backscatter) in the vicinity of clouds for each smoke event.

  8. Elaboration of Co-60 sources on gilding vyns, with beta efficiencies 80 % or better and its activity measure by the coincidences method

    International Nuclear Information System (INIS)

    The measuring technique of radioactive activity by the coincidences method 4 π β- γ it requires of the elaboration of radioactive sources on thin supports in order to flows the biggest percentage of beta particles, those of the order of the 80 % or but. In this work a procedure for the elaboration of this type of sources, with gilding Vyns is reported. (Author)

  9. Pure phase-locking of beta/gamma oscillation contributes to the N30 frontal component of somatosensory evoked potentials

    Directory of Open Access Journals (Sweden)

    Leroy Axelle

    2007-09-01

    Full Text Available Abstract Background Evoked potentials have been proposed to result from phase-locking of electroencephalographic (EEG activities within specific frequency bands. However, the respective contribution of phasic activity and phase resetting of ongoing EEG oscillation remains largely debated. We here applied the EEGlab procedure in order to quantify the contribution of electroencephalographic oscillation in the generation of the frontal N30 component of the somatosensory evoked potentials (SEP triggered by median nerve electrical stimulation at the wrist. Power spectrum and intertrial coherence analysis were performed on EEG recordings in relation to median nerve stimulation. Results The frontal N30 component was accompanied by a significant phase-locking of beta/gamma oscillation (25–35 Hz and to a lesser extent of 80 Hz oscillation. After the selection in each subject of the trials for which the power spectrum amplitude remained unchanged, we found pure phase-locking of beta/gamma oscillation (25–35 Hz peaking about 30 ms after the stimulation. Transition across trials from uniform to normal phase distribution revealed temporal phase reorganization of ongoing 30 Hz EEG oscillations in relation to stimulation. In a proportion of trials, this phase-locking was accompanied by a spectral power increase peaking in the 30 Hz frequency band. This corresponds to the complex situation of 'phase-locking with enhancement' in which the distinction between the contribution of phasic neural event versus EEG phase resetting is hazardous. Conclusion The identification of a pure phase-locking in a large proportion of the SEP trials reinforces the contribution of the oscillatory model for the physiological correlates of the frontal N30. This may imply that ongoing EEG rhythms, such as beta/gamma oscillation, are involved in somatosensory information processing.

  10. Sensorimotor and cognitive involvement of the beta-gamma oscillation in the frontal N30 component of somatosensory evoked potentials.

    Science.gov (United States)

    Cebolla, A M; Cheron, G

    2015-12-01

    The most consistent negative cortical component of somatosensory evoked potentials (SEPs), namely the frontal N30, can be considered more multidimensional than a strict item of standard somatosensory investigation, dedicated to tracking the afferent volley from the peripheral sensory nerve potentials to the primary somatosensory cortex. In this review, we revisited its classical sensorimotor implication within the framework of the recent oscillatory model of ongoing electroencephalogram (EEG) rhythms. Recently, the N30 component was demonstrated to be related to an increase in the power of beta-gamma EEG oscillation and a phase reorganization of the ongoing EEG oscillations (phase locking) in this frequency band. Thanks to high density EEG recordings and the inverse modeling method (swLORETA), it was shown that different overlapping areas of the motor and premotor cortex are specifically involved in generating the N30 in the form of a beta gamma oscillatory phase locking and power increase. This oscillatory approach has allowed a re-investigation of the movement gating behavior of the N30. It was demonstrated that the concomitant execution of finger movements by a stimulated hand impinges the temporal concentration of the ongoing beta/gamma EEG oscillations and abolished the N30 component. It was hypothesized that the involvement of neuronal populations in both the sensorimotor cortex and other related areas were unable to respond to the phasic sensory activation so could not phase-lock their oscillatory signals to the external sensory input during the movement. In this case, the actual movement has primacy over the artificial somatosensory input. The contribution of the ongoing oscillatory activity in the N30 emergence calls for a reappraisal of fundamental and clinical interpretations of the frontal N30 component. An absent or reduced amplitude of the N30 can now be viewed not only as a deficit in the activation of the somatosensory synaptic network in response

  11. Development of an in-situ structure/photo-absorption coincident measurement system for precise structure-optical property relationship research at SPring-8

    Science.gov (United States)

    Kim, Jungeun; Kato, Kenichi; Moritomo, Yutaka; Takata, Masaki

    2010-06-01

    We have developed the structure and optical property coincident measurement system equipped with the photo-absorption system to the Large Debye-Scherrer Camera at BL44B2 of the SPring-8. Both photo-absorption detecting systems, the Si pin-photo diode for a 532 nm CW laser and the absorption spectrum covered the range of UV-IR (200˜1400 nm) for a white beam, are adopted. In order to verify the coincident measurement system, the X-ray powder diffraction and photo-absorption with the cyanide complex were performed individually and simultaneously under the temperature changes. As a result, the coincident measurement system performed successfully the one-to-one corresponding measurement between X-ray diffraction and photo-absorption. In addition, the monitoring of the photo-absorption informed us the property change of the material for the measurement condition and the sample transformation by temperature, laser etc. as well as damage by high-brilliance synchrotron radiation X-ray beam.

  12. The su-bar(2){sub -1/2} WZW model and the {beta}{gamma} system

    Energy Technology Data Exchange (ETDEWEB)

    Lesage, F. E-mail: lesage@crm.umontreal.ca; Mathieu, P. E-mail: pmathieu@phy.ulaval.ca; Rasmussen, J. E-mail: rasmusse@crm.umontreal.ca; Saleur, H. E-mail: saleur@usc.edu

    2002-12-30

    The bosonic {beta}{gamma} ghost system has long been used in formal constructions of conformal field theory. It has become important in its own right in the last few years, as a building block of field theory approaches to disordered systems, and as a simple representative--due in part to its underlying su-bar(2){sub -1/2} structure--of non-unitary conformal field theories. We provide in this paper the first complete, physical, analysis of this {beta}{gamma} system, and uncover a number of striking features. We show, in particular, that the spectrum involves an infinite number of fields with arbitrarily large negative dimensions. These fields have their origin in a twisted sector of the theory, and have a direct relationship with spectrally flowed representations in the underlying su-bar(2){sub -1/2} theory. We discuss the spectral flow in the context of the operator algebra and fusion rules, and provide a re-interpretation of the modular invariant consistent with the spectrum.

  13. INGAS: Iranian Noble Gas Analyzing System for radioxenon measurement

    Science.gov (United States)

    Doost-Mohammadi, V.; Afarideh, H.; Etaati, G. R.; Safari, M. J.; Rouhi, H.

    2016-03-01

    In this article, Iranian Noble Gas Analyzing System (INGAS) will be introduced. This system is based on beta-gamma coincidence technique and consists of a well-type NaI(Tl) as gamma or X radiation detector and a cylindrical plastic scintillator to detect beta or conversion electron. Standard NIM modules were utilized to detect coincidence events of detectors. Both the beta and gamma detectors were appropriately calibrated. The efficiency curve of gamma detector for volume geometry was obtained by comparing the results of gamma point sources measurements and simulations of GATE V7.0 Monte Carlo code. The performance of detection system was checked by injection of 222Rn and 131mXe gaseous source in the detection cell. The minimum detectable activity of the system for 133Xe is 1.240±0.024 mBq for 24 h measurement time.

  14. Advanced Time-Delayed Coincidence Studies of $^{31,32}$Mg from the $\\beta$-decays of $^{31,32}$Na

    CERN Multimedia

    Marechal, F; Plociennik, W A

    2002-01-01

    It is proposed to study the lifetime of the 2$_{1}^{+}$ 885.4 keV state in $^{32}$Mg by means of Advanced Time-Delayed $\\beta \\gamma \\gamma$(t) method with the precision in the half-life value of about $\\pm$ 1.5 ps. This would be an independent verification of the B(E2; 0$_{1}^{+} \\rightarrow$ 2$_{1}^{+}$) values obtained so far in a few studies using Coulomb excitations at intermediate beam energies. The advantage of time-delayed coincidence measurements is that they are free of corrections used in the Coulex studies, which strongly affect the deduced B(E2) results. In addition, we propose to study the lifetimes or lifetime limits of other states in nuclei populated in the decays of $^{31}$Na and $^{32}$Na, specifically focusing on the intruder negative parity band in $^{31}$Mg. As a side benefit to this investigation we expect high-quality $\\gamma \\gamma$ coincidences to reveal new excited states in both $^{31}$Mg and $^{32}$Mg. Our results from a brief test-measurement yield a lifetime of T$_{1/2}$ = 10.5(...

  15. 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

  16. Microcalorimetric and spectrographic studies on host-guest interactions of {alpha}-, {beta}-, {gamma}- and M{beta}-cyclodextrin with resveratrol

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui; Xu, Xiangyu; Liu, Min [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Sun, Dezhi, E-mail: sundezhisdz@163.com [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Li, Linwei, E-mail: lilinwei@lcu.edu.cn [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China)

    2010-10-20

    Thermal effects of inclusion processes of {alpha}-, {beta}-, {gamma}- and M{beta}-cyclodextrin with resveratrol (RES) in aqueous solutions were determined by isothermal titration calorimetry (ITC) with nanowatt sensitivity at the temperature of 298.15 K. Standard enthalpy changes, stoichiometry and equilibrium constants of the inclusion complexes were derived from the direct calorimetric data utilizing nonlinear simulation. The thermodynamic parameters were discussed in the light of weak interactions between the host and the guest molecules combining with UV spectral message. The results indicate that all of the complexes formed in the aqueous solutions are in 1:1 stoichiometry. The binding processes of {alpha}-, {beta}- and M{beta}-cyclodextrin with the guest are mainly driven by enthalpy, while that of {gamma}-cyclodextrin with the drug is driven by both enthalpy and entropy.

  17. 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...

  18. A beta-alpha coincidence counting system for measurement of trace quantities of 238U and 232Th in aqueous samples at the Sudbury Neutrino Observatory.

    Science.gov (United States)

    Dawson, M.; Doucas, G.; Fergani, H.; Jelley, N. A.; Majerus, S.; O'Keeffe, H. M.; Peeters, S. J. M.; Perry, C.

    2016-08-01

    The Sudbury Neutrino Observatory experiment was built to measure the total flux of 8B solar neutrinos via the neutral current disintegration deuterium nuclei. This process can be mimiced by daughter isotopes of 232Th and 238U which can photodisintegrate the deuterium nucleus. Measurement of the concentration of such radioisotopes in the heavy water was critical to the success of the experiment. A radium assay technique using Hydrous Titanium Oxide coated filters was developed for this purpose and it was used in conjunction with a delayed beta-alpha coincidence counting system. The design, calibration and operation of this counting system are described in this paper. The counting efficiency for 232Th (224Ra) and 238U (226Ra) were measured to be 50 ± 5% and 62 ± 7%

  19. Observations of Bathymetry-Induced Ocean Roughness Modulation in In-situ Surface Slope Measurements and Coincident Airborne SAR Images

    NARCIS (Netherlands)

    Gommenginger, C.P.; Robinson, I.S.; Willoughby, J.; Greidanus, H.S.F.; Taylor, V.

    1999-01-01

    Empirical results from a field experiment in the southern North Sea have demonstrated the possibility to detect bathymetry-induced sea surface roughness modulation in the coastal zone using high frequency in-situ slope measurements provided by the Towed Laser Slopemeter. A strong correlation between

  20. Performance of a compact multi-crystal high-purity germanium detector array for measuring coincident gamma-ray emissions

    Energy Technology Data Exchange (ETDEWEB)

    Howard, Chris; Daigle, Stephen; Buckner, Matt [University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Erikson, Luke E.; Runkle, Robert C. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Stave, Sean C., E-mail: Sean.Stave@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Champagne, Arthur E.; Cooper, Andrew; Downen, Lori [University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Glasgow, Brian D. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Kelly, Keegan; Sallaska, Anne [University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States)

    2015-05-21

    The Multi-sensor Airborne Radiation Survey (MARS) detector is a 14-crystal array of high-purity germanium (HPGe) detectors housed in a single cryostat. The array was used to measure the astrophysical S-factor for the {sup 14}N(p,γ){sup 15}O{sup ⁎} reaction for several transition energies at an effective center-of-mass energy of 163 keV. Owing to the granular nature of the MARS detector, the effect of gamma-ray summing was greatly reduced in comparison to past experiments which utilized large, single-crystal detectors. The new S-factor values agree within their uncertainties with the past measurements. Details of the analysis and detector performance are presented.

  1. Effect of double false pulses in calibrated neutron coincidence collar during measuring time-correlated neutrons from PuBe neutron sources

    International Nuclear Information System (INIS)

    Effect of double false pulses of preamplifiers in neutron coincidence collar was investigated to explain non-parallel shape of calibrated D/S–MPu curves of two commercial neutron coincidence collars, JCC-31 and JCC-13. Two curves, which were constructed from D/S ratio (doubles and singles count rate), and Pu content MPu, of the same set of secondary standard PuBe neutron sources, should be parallel. Non-parallelism rises doubt about usability of the method based on this curve for determination of Pu content in PuBe neutron sources. We have shown in three steps that the problem originates from double false pulses of preamplifiers in JCC-13. First we used a pulse train diagram for analyzing the non-parallel shape, second we used Rossi-Alpha distribution measured by pulse train recorder developed in our institute and finally, we investigated the effect of inserted noise pulses. This implies a new type of QA test option in traditional multiplicity shift registers for excluding presence of double false pulses

  2. 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

  3. Inclusion phenomena of clove oil with alpha-, beta-, gamma- and heptakis (2,6-di-O-methyl)-beta-cyclodextrin.

    Science.gov (United States)

    Song, L X; Xu, P; Wang, H M; Yang, Y

    2009-01-01

    Inclusion interactions of alpha-, beta-, gamma- and heptakis (2,6-di-O-methyl)-beta-cyclodextrin (DMbeta-CD) as hosts with clove oil (an impure eugenol, I-Eug) as guest in aqueous solution were investigated by fluorescence emission spectra. The binding constants of different hosts to I-Eug in aqueous solution decreased in the order: gamma- > beta- > DMbeta- > alpha-CD. Two solid supramolecular inclusion complexes, I-Eug-beta-CD and I-Eug-gamma-CD, were prepared and characterised by nuclear magnetic resonance, powder X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis. All the results proved the formation of I-Eug-CD. The inclusion differences between I-Eug and pure eugenol were discussed. The relative contents of the main component eugenol (Eug), second component (eugenol acetate, Eua) and others in I-Eug were found to be fairly different before and after being included by beta-CD, according to the data obtained from high performance liquid chromatography. This could be a practical method to extract the effective components (Eug and Eua) from I-Eug.

  4. Coincident measurements of PMSE and NLC above ALOMAR (69° N, 16° E by radar and lidar from 1999–2008

    Directory of Open Access Journals (Sweden)

    N. Kaifler

    2010-10-01

    Full Text Available Polar Mesosphere Summer Echoes (PMSE and Noctilucent Clouds (NLC have been routinely measured at the ALOMAR research facility in Northern Norway (69° N, 16° E by lidar and radar, respectively. 2900 h of lidar measurements by the ALOMAR Rayleigh/Mie/Raman lidar were combined with almost 18 000 h of radar measurements by the ALWIN VHF radar, all taken during the years 1999 to 2008, to study simultaneous and common-volume observations of both phenomena. PMSE and NLC are known from both theory and observations to be positively linked. We quantify the occurrences of PMSE and/or NLC and relations in altitude, especially with respect to the lower layer boundaries. The PMSE occurrence rate is with 75.3% considerably higher than the NLC occurrence rate of 19.5%. For overlapping PMSE and NLC observations, we confirm the coincidence of the lower boundaries and find a standard deviation of 1.26 km, hinting at very fast sublimation rates. However, 10.1% of all NLC measurements occur without accompanying PMSE. Comparison of occurrence rates with solar zenith angle reveals that NLC without PMSE mostly occur around midnight indicating that the ice particles were invisible to the radar due to the reduced electron density.

  5. 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.

  6. Coincident linkage of type 2 diabetes, metabolic syndrome, and measures of cardiovascular disease in a genome scan of the diabetes heart study.

    Science.gov (United States)

    Bowden, Donald W; Rudock, Megan; Ziegler, Julie; Lehtinen, Allison B; Xu, Jianzhao; Wagenknecht, Lynne E; Herrington, David; Rich, Stephen S; Freedman, Barry I; Carr, J Jeffrey; Langefeld, Carl D

    2006-07-01

    Cardiovascular disease (CVD) is a major contributor to morbidity and mortality in type 2 diabetes, but the relationship between CVD and type 2 diabetes is not well understood. The Diabetes Heart Study is a study of type 2 diabetes-enriched families extensively phenotyped for measures of CVD, type 2 diabetes, and metabolic syndrome. A total of 977 Caucasian subjects from 358 pedigrees (575 type 2 diabetic relative pairs) with at least two individuals with type 2 diabetes and, where possible, unaffected siblings were included in a genome scan. Qualitative traits evaluated in this analysis are with or without the presence of coronary calcified plaque (CCP) and with or without carotid calcified plaque (CarCP) measured by electrocardiogram-gated helical computed tomography. In addition, prevalent CVD was measured using two definitions: CVD1, based on self-reported history of clinical CVD (393 subjects), and CVD2, defined as CVD1 and/or CCP >400 (606 subjects). These discrete traits (type 2 diabetes, metabolic syndrome, CVD1, CVD2, CCP, and CarCP) frequently coincide in the same individuals with concordance ranging from 42.9 to 99%. Multipoint nonparametric linkage analysis revealed evidence for coincident mapping of each trait (type 2 diabetes, metabolic syndrome, CVD1, CVD2, CCP, and CarCP) to three different genomic regions: a broad region on chromosome 3 (70-160 cM; logarithm of odds [LOD] scores ranging between 1.15 and 2.71), chromosome 4q31 (peak LOD 146 cM; LOD scores ranging between 0.90 and 2.41), and on chromosome 14p (peak LOD 23 cM; LOD scores ranging between 1.43 and 2.31). Ordered subset analysis (OSA) suggests that the linked chromosome 3 region consists of at least two separate loci on 3p and 3q. In addition, OSA based on lipid measures and other traits identify family subsets with significantly stronger evidence of linkage (e.g., CVD2 on chromosome 3 at 87 cM subsetting on low HDL with an initial LOD of 2.19 is maximized to an LOD of 7.04 in a subset of

  7. 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

  8. One year of CNR-IMAA multi-wavelength Raman lidar measurements in coincidence with CALIPSO overpasses: Level 1 products comparison

    Directory of Open Access Journals (Sweden)

    L. Mona

    2009-09-01

    Full Text Available At CNR-IMAA, an aerosol lidar system has operated since May 2000 in the framework of EARLINET (European Aerosol Research Lidar Network, the first lidar network for tropospheric aerosol study on a continental scale. High quality multi-wavelength measurements make this system a reference point for the validation of data products provided by CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations, the first satellite-borne lidar specifically designed for aerosol and cloud study. Since 14 June 2006, dedicated measurements have been performed at CNR-IMAA in coincidence with CALIPSO overpasses. For the first time, results on 1-year comparisons between ground-based multi-wavelength Raman lidar measurements and corresponding CALIPSO lidar Level 1 profiles are presented. A methodology for the comparison is presented and discussed in detail. Night-time cases are considered to take advantage from Raman capability of the ground based lidar. Cases with the detection of cirrus clouds in CALIPSO data are separately analysed for taking into account multiple scattering effects. For cirrus cloud cases, few cases are available to draw any conclusions. For clear sky conditions, the comparison shows good performances of the CALIPSO on-board lidar: the mean relative difference between the ground-based and CALIPSO Level 1 measurements is always within its standard deviation at all altitudes, with a mean difference in the 3–8 km altitude range of (−2±12%. At altitude ranges corresponding to the typical PBL height observed at CNR-IMAA, a mean difference of (−24±20% is observed in CALIPSO data, probably due to the difference in the aerosol content at the location of PEARL and CALIPSO ground-track location. Finally, the mean differences are on average lower at all altitude ranges for the closest overpasses (at about 40 km respect to the 80-km overpasses.

  9. Measurement of the activity of the radiopharmaceuticals used in therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sahagia, M.; Razdolescu, A.C.; Grigorescu, E.L.; Luca, A.; Ivan, C. [National Institute of R and D for Physics and Nuclear Engineering ' Horia Hulubei' IFIN-HH, POB MG-6, Bucharest (Romania)

    2006-07-01

    The paper presents the results obtained in the assurance of the whole traceability chain in the measurement of the activity for a particular group of radionuclides used as therapeutic pharmaceuticals: strong beta - weak gamma emitters, such as: 153 Sm, 177 Lu, 186 Re, 188 Re. The regulations regarding the uncertainty of the activity of therapy radiopharmaceuticals impose a maximum limit of 5%. All the above mentioned radionuclides belong to the group of triangular decay scheme and consequently they were standardized absolutely by the 4{pi}{beta}-{gamma} coincidence method. The solutions were then used for the calibration of the secondary standard, consisting from a 'Centronic I.G.12/20 A' ionization chamber. The calibration was transferred to the commercial radioisotope calibrators, as initial calibration figures. Some of these results are presented in the paper. (author)

  10. Analysis of beta, gamma, and delta T-cell receptor genes in mycosis fungoides and Sezary syndrome.

    Science.gov (United States)

    Whittaker, S J; Smith, N P; Jones, R R; Luzzatto, L

    1991-10-01

    The authors have analyzed the configuration of immunoglobulin (Ig) and beta, gamma and delta T-cell receptor (TCR) genes in DNA extracted from skin, lymph nodes, and peripheral blood mononuclear cells obtained from 41 patients with mycosis fungoides (MF), 14 patients with Sezary syndrome, and 13 patients with benign inflammatory dermatoses. No discrete rearranged bands (DRB) were detected in patients with inflammatory dermatoses. In tissue DNA from 19 patients with MF DRB were detected with beta and gamma, but not delta TCR probes. Only one patient with MF had a rearrangement of gamma and delta with germ line beta TCR genes. In 13 patients multiple biopsies were analyzed and DRB, when present, were identical in different lesions from individual patients. In three patients analysis of DNA from dermatopathic lymph nodes did not reveal DRB. Analysis of peripheral blood DNA from 24 patients revealed a discrete rearrangement of the gamma TCR gene in four patients and both beta and gamma genes in four additional patients. In MF DRB were detected more frequently with advancing stage of disease in tissues (P less than 0.01) but not in peripheral blood (P equals 0.36). Of 14 patients with Sezary syndrome, eight had DRB in peripheral blood DNA with both beta and gamma probes and in three of these patients identical DRB were also detected in DNA from skin biopsy samples. In contrast, DRB were not detected in the peripheral blood of the other six patients. In both MF and Sezary syndrome there was no restricted usage of particular V gamma genes. These results indicate that in MF (1) T-cell clones can be detected in skin biopsy specimens from the majority of patients with early stage disease, (2) gamma delta T-cell clones are only rarely found, and (3) TCR gene analysis can detect T-cell clones in the peripheral blood with a greater degree of specificity than conventional light microscopic study. In Sezary syndrome these studies also suggest that a subset of patients have a

  11. 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.

  12. Precision measurement of the half-life and the decay branches of Ga-62

    NARCIS (Netherlands)

    Canchel, G; Blank, B; Chartier, N; Delalee, F; Dendooven, P; Dossat, C; Giovinazzo, J; Huikari, J; Lalleman, AS; Jimenez, MJL; Madec, [No Value; Pedroza, JL; Penttila, H

    2005-01-01

    In an experiment performed at the Accelerator Laboratory of the University of Jyvaskyla, the beta-decay half-life of Ga-62 has been studied with high precision rising the IGISOL technique. A half-life of T-1/2 = 116.09(17) ms was nieasured. Using beta-gamma coincidences, the gamma intensity of the 9

  13. 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.

  14. Influence of nonstatistical variations on low-level measurements of 131I in milk

    International Nuclear Information System (INIS)

    The procedure described in the U. S. Atomic Energy Commission Regulatory Guide 4.3, which is intended to keep 131I levels in milk ''as low as practicable,'' does not properly account for all sources of analytical error that can occur in a low-level radiochemical procedure. Inaccurate chemical recovery factors due to large amounts of stable iodine in milk and incomplete evaluation of detector background fluctuations are the sources of largest error. Significant errors are also contributed in incorrect application of factors for protein-bound iodine and counting efficiency. Ambient levels of 131I contribute to difficulties in evaluating the local impact of any reactor. Use of a beta/gamma coincidence system for counting 131I, measurement of the stable iodine in milk samples and collection of control samples remote from any site are among the recommendations provided to ensure compliance with the Regulatory Guides

  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. A practical method for determining γ-ray full-energy peak efficiency considering coincidence-summing and self-absorption corrections for the measurement of environmental samples after the Fukushima reactor accident

    Science.gov (United States)

    Shizuma, Kiyoshi; Oba, Yurika; Takada, Momo

    2016-09-01

    A method for determining the γ-ray full-energy peak efficiency at positions close to three Ge detectors and at the well port of a well-type detector was developed for measuring environmental volume samples containing 137Cs, 134Cs and 40K. The efficiency was estimated by considering two correction factors: coincidence-summing and self-absorption corrections. The coincidence-summing correction for a cascade transition nuclide was estimated by an experimental method involving measuring a sample at the far and close positions of a detector. The derived coincidence-summing correction factors were compared with those of analytical and Monte Carlo simulation methods and good agreements were obtained. Differences in the matrix of the calibration source and the environmental sample resulted in an increase or decrease of the full-energy peak counts due to the self-absorption of γ-rays in the sample. The correction factor was derived as a function of the densities of several matrix materials. The present method was applied to the measurement of environmental samples and also low-level radioactivity measurements of water samples using the well-type detector.

  17. 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.)

  18. Special Analysis for the Disposal of the Lawrence Livermore National Laboratory Low Activity Beta/Gamma Sources Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Shott, Gregory J. [National Security Technologies, LLC

    2015-06-01

    This special analysis (SA) evaluates whether the Lawrence Livermore National Laboratory (LLNL) Low Activity Beta/Gamma Sources waste stream (BCLALADOEOSRP, Revision 0) is suitable for disposal by shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site (NNSS). The LLNL Low Activity Beta/Gamma Sources waste stream consists of sealed sources that are no longer needed. The LLNL Low Activity Beta/Gamma Sources waste stream required a special analysis because cobalt-60 (60Co), strontium-90 (90Sr), cesium-137 (137Cs), and radium-226 (226Ra) exceeded the NNSS Waste Acceptance Criteria (WAC) Action Levels (U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office [NNSA/NFO] 2015). The results indicate that all performance objectives can be met with disposal of the LLNL Low Activity Beta/Gamma Sources in a SLB trench. The LLNL Low Activity Beta/Gamma Sources waste stream is suitable for disposal by SLB at the Area 5 RWMS. However, the activity concentration of 226Ra listed on the waste profile sheet significantly exceeds the action level. Approval of the waste profile sheet could potentially allow the disposal of high activity 226Ra sources. To ensure that the generator does not include large 226Ra sources in this waste stream without additional evaluation, a control is need on the maximum 226Ra inventory. A limit based on the generator’s estimate of the total 226Ra inventory is recommended. The waste stream is recommended for approval with the control that the total 226Ra inventory disposed shall not exceed 5.5E10 Bq (1.5 Ci).

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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)

  5. 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...

  6. Experimental and theoretical studies on the inclusion complexation of syringic acid with alpha-, beta-, gamma- and heptakis(2,6-di-O-methyl)-beta-cyclodextrin.

    Science.gov (United States)

    Song, Le Xin; Wang, Hai Ming; Xu, Peng; Yang, Yan; Zhang, Zi Qiang

    2008-04-01

    Intermolecular interactions of alpha-, beta-, gamma- and heptakis(2,6-di-O-methyl)-beta-cyclodextrin (CD) with syringic acid (Syr) in aqueous solution are investigated by fluorescence spectroscopy. The fluorescence intensity of Syr gradually increases with the addition of the CDs. The formation constants (K) of the host-guest inclusion complexes are determined using a nonlinear analysis. The association abilities of Syr with the CDs decrease in the order gamma->beta->alpha- approximately DMbeta-CD. Both the intrinsic binding abilities of the CDs and the structural effect of Syr are taken into consideration when comparing the K values. Based on the results of NMR experimental and theoretical PM3 calculations both in vacuo and in water, it is found that Syr stays near the wider rim of alpha-CD cavity. Both the number of substituted groups (NSG) in a guest and the molar volume ratio of the guest to host cavity (MVR) play an important role in forming the CD supramolecular complexes of a homologous series of phenol derivatives, such as 2-methoxylphenol (2-Mop), eugenol (Eug) and Syr, i.e., an appropriate NSG or MVR in an inclusion system, such as in 2-Mop-alpha-CD, Eug-beta-CD and Syr-gamma-CD systems, can maximize the intermolecular interaction between host and guest.

  7. Precise measurement of gamma-ray emission probabilities for 187W by using a two-dimensional 4πβ-γ coincidence system

    International Nuclear Information System (INIS)

    Gamma-ray emission probabilities for 187W have been determined with uncertainties less than 1% from measurement of absolute γ-ray intensities and disintegration rate. The measured emission probabilities are larger than those previously reported by about 20% and hence the β-ray branching ratio to the ground state has to be smaller than about 40%. The decay scheme of 187W calculated by using the present results is given as a final result. (author)

  8. Absolute activity measurement and gamma-ray emission probability for decay of I-126; Medida absoluta da atividade e determinacao da taxa de emissao gama por decaimento do {sup 126} I

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Katia Aparecida

    1997-07-01

    The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of {sup 126} I, its importance lies mainly in fast neutron dosimetry as well as in the production of {sup 125} I where {sup 126} I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of {sup 126} I have been measured. This radionuclide was obtained by means of the {sup 127} I(n, 2n){sup 126} I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of {sup 126} I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The {beta}branch measurement was carried out in a 4 {pi}(PC){beta}-{gamma} coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch was measured in a X-{gamma} coincidence system using two NaI(Tl) crystals. The gamma-ray measurements were performed in a HPGe system, previously calibrated by means of standard sources supplied by the International Atomic Energy Agency. All the uncertainties evolved were treated rigorously, by means of covariance analysis. (author)

  9. 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....

  10. 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)

  11. Spectral shapes and a beta-gamma directional correlation in the beta decay of 172Tm (Jpi = 2-)

    DEFF Research Database (Denmark)

    Gregers Hansen, P.; Loft Nielsen, H.; Wilsky, K.;

    1966-01-01

    shape factor plots are taken relative to the 90Y shape factor measured in the same circumstances, and it is concluded that on this basis the shapes of all three 172Tm beta groups agree with the theoretical shape for a first-forbidden unique transition. The directional correlation for the 2-(beta)2......+(gamma)0+ cascade has been measured at six energies from 1010 to 1550 keV and these results too are consistent with the assumption that the 2- rarr 2+ beta transition is purely of tensor rank 2. The data for the 2- rarr 2+ transition are analysed on the basis of the modified Bij approximation, which...... defines parameters X and Y corresponding to the relative contributions of tensor ranks 0 and 1 respectively. The shape measurement provides the limit X2 + Y2 les 0.10, whereas the angular correlation measurement gives Y = 1.64X + (0.02 plusmn0.03). The reduced transition probabilities (f1t)-1 can...

  12. β-Arrestin interacts with the beta/gamma subunits of trimeric G-proteins and dishevelled in the Wnt/Ca(2+ pathway in xenopus gastrulation.

    Directory of Open Access Journals (Sweden)

    Katharina Seitz

    Full Text Available β-Catenin independent, non-canonical Wnt signaling pathways play a major role in the regulation of morphogenetic movements in vertebrates. The term non-canonical Wnt signaling comprises multiple, intracellularly divergent, Wnt-activated and β-Catenin independent signaling cascades including the Wnt/Planar Cell Polarity and the Wnt/Ca(2+ cascades. Wnt/Planar Cell Polarity and Wnt/Ca(2+ pathways share common effector proteins, including the Wnt ligand, Frizzled receptors and Dishevelled, with each other and with additional branches of Wnt signaling. Along with the aforementioned proteins, β-Arrestin has been identified as an essential effector protein in the Wnt/β-Catenin and the Wnt/Planar Cell Polarity pathway. Our results demonstrate that β-Arrestin is required in the Wnt/Ca(2+ signaling cascade upstream of Protein Kinase C (PKC and Ca(2+/Calmodulin-dependent Protein Kinase II (CamKII. We have further characterized the role of β-Arrestin in this branch of non-canonical Wnt signaling by knock-down and rescue experiments in Xenopus embryo explants and analyzed protein-protein interactions in 293T cells. Functional interaction of β-Arrestin, the β subunit of trimeric G-proteins and Dishevelled is required to induce PKC activation and membrane translocation. In Xenopus gastrulation, β-Arrestin function in Wnt/Ca(2+ signaling is essential for convergent extension movements. We further show that β-Arrestin physically interacts with the β subunit of trimeric G-proteins and Dishevelled, and that the interaction between β-Arrestin and Dishevelled is promoted by the beta/gamma subunits of trimeric G-proteins, indicating the formation of a multiprotein signaling complex.

  13. Isozyme-specific enzyme inhibitors. 14. 5'(R)-C-[(L-homocystein-S-yl)methyl]adenosine 5'-(beta,gamma-imidotriphosphate), a potent inhibitor of rat methionine adenosyltransferases.

    Science.gov (United States)

    Kappler, F; Vrudhula, V M; Hampton, A

    1987-09-01

    The title compound is a covalent adduct of L-methionine (Met) and beta,gamma-imido-ATP. In its synthesis the N-Boc derivative of 5'(R)-C-(aminomethyl)-N6-benzoyl-5'-O-tosyl-2',3'-O- isopropylidenadenosine was converted by the successive actions of CF3CO2H and HNO2 into the corresponding 5'(R)-C-hydroxymethyl derivative. Treatment of this with disodium L-homocysteinate led to attack of sulfur at C6', apparently via a 5',6'-epoxide, and to total stereoselective inversion at C5' to furnish, after debenzoylation, 5'(R)-C-(L-homocystein-S-ylmethyl)-2',3'-O-isopropylidene ade nosine. The 5' configuration was established by conversion of this into the known 5'(S)-C-methyl-2',3'-O-isopropylidene adenosine with Raney nickel. The alpha-amino acid residue was protected as an N-Boc methyl ester, after which the 5'-hydroxyl was phosphorylated with benzyl phosphate and dicyclohexylcarbodiimide. The phosphoanhydride bond with inorganic imidodiphosphate was then created by established methods. Finally, blocking groups were removed under conditions that gave the desired adduct with no racemization of its L-methionine residue. It was a potent inhibitor [KM(ATP)/Ki = 1080; KM(Met)/Ki = 7.7] of the M-2 (normal tissue) form of rat methionine adenosyltransferase and of the M-T (hepatoma tissue) form [KM(ATP)/Ki = 670; KM(Met)/Ki = 22]. Inhibitions were competitive with respect to ATP or to L-methionine, indicating a dual substrate site mode of binding to the enzyme forms.

  14. 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...

  15. Absolute activity measurement and gamma-ray emission probability for decay of I-126

    CERN Document Server

    Fonseca, K A

    1997-01-01

    The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of sup 1 sup 2 sup 6 I, its importance lies mainly in fast neutron dosimetry as well as in the production of sup 1 sup 2 sup 5 I where sup 1 sup 2 sup 6 I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of sup 1 sup 2 sup 6 I have been measured. This radionuclide was obtained by means of the sup 1 sup 2 sup 7 I(n, 2n) sup 1 sup 2 sup 6 I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of sup 1 sup 2 sup 6 I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The beta branch measurement was carried out in a 4 pi(PC)beta-gamma coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch ...

  16. 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.

  17. Measurement of the sp ectral prop erties of the coincident-frequency entangled biphoton state at optical communication wavelength%通信波长频率一致纠缠光源的频谱测量

    Institute of Scientific and Technical Information of China (English)

    王盟盟; 权润爱; 邰朝阳; 侯飞雁; 刘涛; 张首刚; 董瑞芳

    2014-01-01

    The frequency entangled biphoton source generated via spontaneous parametric down-conversion (SPDC) process has found important applications in the fields of quantum clock synchronization, quantum communication, quantum information processing, etc. As quantum technologies evolve, quantitative characterization of the frequency entanglement becomes necessary and has been implemented by measuring the spectral properties of the biphoton state. However, due to the high dark rate and low quantum efficiency of the InGaAs single-photon detectors, direct measurement of the spectral properties of the biphoton state at optical communication wavelength is hard to implement. In this paper, we report the measurement of the spectral properties of a biphoton state at optical communication wavelength which is generated from periodically poled potassium titanyl phosphate (PPKTP) pumped by an ultra-short pulsed optical source at 787 nm. Based on the coincidence measurement setup together with two infrared spectrometers, the spectra of the signal and idler photons are obtained with their center wavelengths being 1574.4 nm and 1574.9 nm, while their 3-dB bandwidths being 35.3 nm and 37.6 nm respectively. The joint spectrum of the photon pair is observed as well and shows a coincident-frequency entanglement and a joint spectrum bandwidth of 3 nm. According to the ratio of the single-photon spectral bandwidth to the joint spectral bandwidth of the photon pairs, the degree of frequency entanglement is quantified to be 12, denoting a relatively high quality of the entanglement.%本文利用光栅单色仪实现了对超短脉冲抽运周期极化磷酸氧钛钾晶体产生的通信波长频率一致纠缠光子源的频谱特性分析.测量到双光子的联合频谱呈正关联分布,为频率一致纠缠光源.信号光、闲置光中心波长分别为1574.4 nm和1574.9 nm,频谱宽度分别为35.3 nm和37.6 nm,双光子符合包络宽度约为3 nm.根据单光子频谱宽度与双光

  18. Detection limit for activation measurements in ultralow background sites

    Science.gov (United States)

    Trache, Livius; Chesneanu, D.; Margineanu, R.; Pantelica, A.; Ghita, D. G.; Burducea, I.; Straticiuc, M.; Tang, X. D.

    2014-09-01

    We used 12C +13C fusion at the beam energies E = 6, 7 and 8 MeV to determine the sensitivity and the limits of activation method measurements in ultralow background sites. A 13C beam of 0.5 μA from the 3 MV Tandem accelerator of the Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH impinged on thick graphite targets. After about 24 hrs of irradiation targets were measured in two different laboratories: one with a heavy shielded Ge detector in the institute (at the surface) and one located underground in the microBequerel laboratory, in the salt mine of Slanic-Prahova, Romania. The 1369- and 2754 keV peaks from 24Na deactivation were clearly observed in the γ-ray spectra obtained for acquisitions lasting a few hours, or a few days. Determination of the detection limit in evaluating the cross sections for the target irradiated at Ec . m = 3 MeV indicates the fact that it is possible to measure gamma spectrum in underground laboratory down to Ec . m = 2 . 6 MeV. Cleaning the spectra with beta-gamma coincidences and increasing beam intensity 20 times will take as further down. The measurements are motivated by the study of the 12 C +12 C reaction at astrophysical energies.

  19. 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

  20. Miniature proportional counter for compression measurements of laser-fusion targets

    International Nuclear Information System (INIS)

    Direct drive laser fusion targets consisting of DT gas encapsulated in glass microshells produce 14.1 MeV neutrons that can interact with silicon-28 nuclei in the glass to produce a 2.2 minute aluminum-28 activity. From the number of 28Al nuclei created and the neutron yield, the compressed glass areal density can be found. To determine the number of activated atoms created, we collect approximately one-half of the target debris on a thin metal foil which is transferred to our beta-gamma coincidence detector. This detector consists of a 25 cm x 25 cm NaI(Tl) crystal having a 5 cm x 15 cm well. We have recently built a miniature proportional counter that fits into this well and is used to detect beta particles. It is constructed of .025 cm thick copper and has nine separate chambers through which methane flows. The coincidence background is 0.14 cpm and the measured beta efficiency is 45%. We are now building a .0125 cm thick counter made of aluminum having a predicted efficiency of > 90%

  1. Analysis of Coincidence Effect on Natural Radionuclides Radium-226 Measuring by γ Spectrometry%级联符合对天然放射性核素镭-226γ能谱测量的影响分析

    Institute of Scientific and Technical Information of China (English)

    周程; 刘晓平

    2012-01-01

    介绍了226Ra的γ能谱测量方法,通过对标准样品和环境样品的测量,分析说明了利用214 Pb的特征γ射线全能峰(351.93和295.22 keV)来测定母体226Ra的活度是准确可靠的,214Bi的特征γ射线全能峰609.32 keV存在严重的级联符合相加,也说明了在利用存在级联跃迁的特征γ射线进行活度计算时应对测量结果进行校正.%It introduces the γ-ray spectrometry method for Ra measurement. By measuring standard samples and environmental samples , analysis shows that the use of the γ characteristics peak (351.93 keV and 295. 22 keV) of 214Pb to determine the activity of the parent 226Ra is reliable, cascade coincidence summing is seriously around γ - ray characteristics peak (609.32 keV) of 214Bi , also illustrates results of activity should be corrected once using γ characteristics peaks exist cascade.

  2. 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

  3. Spectra of radioactive nuclides radiation, measured with semiconductor detectors. 2

    International Nuclear Information System (INIS)

    The second part of the atlas 'Radiation spectra of radionuclides measured with semiconductor detectors' is presented including 259 spectra of 126 alpha, beta, gamma, and X ray emitters. Some spectra of the first part of the atlas are given at another scale and sometimes for other energy ranges. The total number of investigated radionuclides amounts to 261 of which 69 are new ones

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. RADIOXENON MEASUREMENTS WITH THE PHOSWATCH DETECTOR SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Hennig, Wolfgang; Warburton, William K.; Fallu-Labruyere, A.; Sabourov, K.; Cooper, Matthew W.; McIntyre, Justin I.; Gleyzer, A.; Bean, Marc; Korpach, E.; Ungar, R. Kurt; Zhang, W.; Mekarski, P.; Ward, Rebecca; Biegalski, S.; Haas, Derek A.

    2009-09-22

    Many of the radioxenon detector systems used in the International Monitoring System and in other applications employ beta/gamma coincidence detection to achieve high sensitivity. In these systems, the coincidence detection is implemented by requiring simultaneous signals from separate beta and gamma detectors. While very sensitive to small amounts of radioxenon, this approach requires careful calibration and gain matching of several detectors and photomultiplier tubes. An alternative approach is the use of a phoswich detector in which beta-gamma coincidences are detected by pulse shape analysis. The phoswich requires only a single photomultiplier tube and thus is easier to set up and calibrate, and can be assembled into a more compact and robust system. In the past, we have developed a COTS detector system, named PhosWatch, which consists of a CsI(Tl)/BC-404 phoswich detector, digital readout electronics, and on-board software to perform the pulse shape analysis. Several units of this system have been manufactured and are now evaluated at several radioxenon research laboratories. In this paper, we will report results from production tests and some of the evaluations, including a side-by-side comparison of a SAUNA detector and a PhosWatch system using atmospheric radioxenon samples. In addition, we will show initial results obtained with a higher speed version of the readout electronics, digitizing at 500 MHz and thus able to better resolve the fast pulses from the BC-404.

  9. Spectroscopy and lifetime measurements of states in $^{76}$Kr populated in $^{76}$Rb decay

    CERN Document Server

    Giannatiempo, A; Perego, A; Sona, P; Mach, H; Fogelberg, B; García-Borge, M J; Tengblad, O; Fraile-Prieto, L M; Aas, A J; Gulda, K; CERN. Geneva

    2005-01-01

    The properties of the excited states of $^{76}$Kr, populated in the decay of $^{76}$Rb produced at ISOLDE isotopic separator, have been investigated by using K-conversion electron, $\\gamma$-ray, and $\\gamma\\gamma$ coincidence measurements. The lifetimes of several levels have been measured by means of the Advanced Time-Delayed $\\beta\\gamma\\gamma (t)$ method. The identification of 19 new levels and 55 transitions and the information deduced on spin and/or parity of the observed states from K-conversion coefficients, log ft values and decay properties have led to an improved knowledge of the level scheme. In particular, six 1$^-$ states have been definitely identified and $J^{\\pi} =2^{-}$ has been assigned to the 2227 keV level, on which a band proposed to have negative-parity and even-spin had been previously observed. The strengths of the $E$0 and $E$2 transitions de-exciting the 0$^{+}_{2}$ and 0$^{+}_{3}$ states (the latter is here identified with the state at 1598 keV) have been measured. The experimental ...

  10. 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.

  11. Exploitation of the FLK-60 slagging incinerator for different alpha waste streams and study of the feasibility of medium-level alpha-beta-gamma waste incineration in FLK-60

    International Nuclear Information System (INIS)

    The FLK-60 high temperature slagging incinerator and its peripherals were developed by SCK/CEN with the help of the Commission of the European Communities in the framework of contract no. EUR-017-76-7 WAS-B. This second contract, which covered the period between October 1980 and December 1982, aimed at gaining exploitation experience by running the FLK-60 installation with beta-gamma radioactive waste in semi-industrial conditions. At the end of those 27 months, the system was ready for exploitation in alpha-conditions with plutonium-containing materials. This report describes the various plant parameters during the 25 runs carried out in the framework of this contract and the results of characterization tests carried out on the final product and the secondary waste streams. In the meantime, typical operation balances are computed

  12. 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.

  13. Artifacts in Digital Coincidence Timing

    OpenAIRE

    Moses, W. W.; Peng, Q.

    2014-01-01

    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 diff...

  14. 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).

  15. 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

  16. 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 ...

  17. Application of Monte Carlo method in study of the padronization for radionuclides with complex disintegration scheme in 4πβ-γ coincidence System

    International Nuclear Information System (INIS)

    The present work described a new methodology for modelling the behaviour of the activity in a 4πβ-γ coincidence system. The detection efficiency for electrons in the proportional counter and gamma radiation in the NaI(Tl) detector was calculated using the Monte Carlo program MCNP4C. Another Monte Carlo code was developed which follows the path in the disintegration scheme from the initial state of the precursor radionuclide, until the ground state of the daughter nucleus. Every step of the disintegration scheme is sorted by random numbers taking into account the probabilities of all β- branches, electronic capture branches, transitions probabilities and internal conversion coefficients. Once the final state was reached beta, electronic capture events and gamma transitions are accounted for the three spectra: beta, gamma and coincidence variation in the beta efficiency was performed simulating energy cut off or use of absorbers (Collodion). The selected radionuclides for simulation were: 134Cs, 72Ga which disintegrate by β- transition, 133Ba which disintegrates by electronic capture and 35S which is a beta pure emitter. For the latter, the Efficiency Tracing technique was simulated. The extrapolation curves obtained by Monte Carlo were filled by the Least Square Method with the experimental points and the results were compared to the Linear Extrapolation method. (author)

  18. 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

  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. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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

  7. Protective measures for personnel

    Energy Technology Data Exchange (ETDEWEB)

    Nickson, J.J.

    1946-12-13

    This document addresses radiation protection concerns for workers in the experimental laboratories and production plants where nuclear fission piles are being used. A broad in-depth discussion is provided based with the experiences gained in the Manhattan Project and being applied to contemporary activities. Discussion is thorough and encompasses control of external irradiations including alpha, beta, gamma, and neutron radiations; and control of radioactivity within the body by control of inhalation, ingestion, and entrance through skin or wounds. General measures for the control of radiation hazards is addressed by provision of clothing and waste disposal. An Appendix 1 is entitled General Rules and Procedures Concerning Activity Hazards.

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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

  13. Natural radioactivity measurements at the proposed nuclear power plant site

    International Nuclear Information System (INIS)

    Natural radioactivity measurement in the Philippines aims to establish baseline radioactivity levels in the environment of items essential to man. In this article, results of the environmental surveillance conducted in Bagac, Bataan from 1973 to 1974 are presented. Analyses were made on air parti-culates, sea and fresh water, grass, and soil samples for gross beta-gamma activities. Results obtained showed activity levels below the maximum permissible concentration recommended by the International Committee on Radiation Protection (ICRP)

  14. 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.

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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

  1. 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

  2. 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) ...

  3. 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

  4. 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

  5. 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...

  6. 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.

  7. 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.

  8. 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)

  9. Derivation of decay heat benchmarks for U235 and Pu239 by a least squares fit to measured data

    International Nuclear Information System (INIS)

    A least squares technique used by previous authors has been applied to an extended set of available decay heat measurements for both U235 and Pu239 to yield simultaneous fits to the corresponding beta, gamma and total decay heat. The analysis takes account of both systematic and statistical uncertainties, including correlations, via calculations which use covariance matrices constructed for the measured data. The results of the analysis are given in the form of beta, gamma and total decay heat estimates following fission pulses and a range of irradiation times in both U235 and Pu239. These decay heat estimates are considered to form a consistent set of benchmarks for use in the assessment of summation calculations. (author)

  10. 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.

  11. 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

  12. Environmental radiation measurement in CTBT verification system

    International Nuclear Information System (INIS)

    This paper introduces the technical requirements of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) Radionuclide Stations, the CTBT-related activities carried out by the Japan Atomic Energy Research Institute (JAERI), and the ripple effects of such acquired radionuclide data on general researches. The International Monitoring System (IMS), which is one of the CTBT verification regime. Consists of 80 radionuclide air monitoring stations (of those, 40 stations monitor noble gas as well) and 16 certified laboratories that support these stations throughout the world. For radionuclide air monitoring under the CTBT, the stations collect particulates in the atmosphere on a filter and determine by gamma-ray spectrometry the presence or absence of any radionuclides (e.g. 140Ba, 131I, 99Mo, 132Te, 103Ru, 141Ce, 147Nd, 95Zr, etc.) that offer clear evidence of possible nuclear explosion. Minimum technical requirements are stringently set for the radionuclide air monitoring stations: 500 m3/h air flow rate, 24-hour acquisition time, 10 to 30 Bq/m3 of detection sensitivity for 140Ba, and less than 7 consecutive days, or total of 15 days, a year of shutdown at the stations. For noble gas monitoring, on the other hand, the stations separate Xe from gas elements in the atmosphere and, after purifying and concentrating it, measure 4 nuclides, 131mXe, 133Xe, 133mXe, and 135Xe, by gamma-ray spectrometry or beta-gamma coincidence method. Minimum technical requirements are also set for the noble gas measurement: 0.4 m3/h air flow rate, a full capacity of 10 m3, and 1 Bq/m3 of detection sensitivity for 133Xe, etc. On the request of the Ministry of Education, Culture, Sports and Technology, the JAERI is currently undertaking the establishment of the CTBT radionuclide monitoring stations at both Takasaki (both particle and noble gas) and Okinawa (particle), the certified laboratory at JAERI Tokai, and the National Data Center (NDC 2) at JAERI Tokai, which handles radionuclide data, as

  13. Results of the measurement survey of elevation and environmental media in surface impoundments 3513 (B) and 3524 (A) at Oak Ridge National Laboratory, Oak Ridge, TN

    Energy Technology Data Exchange (ETDEWEB)

    Murray, M.E.; Rose, D.A.; Brown, K.S.; Coe, R.H.C. III; Lawrence, J.D.; Winton, W.

    1998-07-01

    A measurement survey of the elevation and environmental media in impoundments 3513 (B) and 3524 (A) at the Oak Ridge National Laboratory (ORNL) was conducted during April 1998. The investigation was performed by the Measurement Applications and Development Group of the Life Sciences Division of ORNL at the request of Bechtel Jacobs Company. Measurement activities were conducted at selected locations in order to determine the depth and appearance of the sediment and describe the clay underlying the impoundments prior to remediation. The survey was a follow-up to a previous elevation survey. The survey included the following: collection of sediment/clay cores from selected locations in each impoundment; measurement and documentation of the elevation at the water surface, at the top of sediment, at the top of clay, and at the bottom of each core; visual inspection of each core by a soil scientist to confirm the presence of clay and not material such as fly ash and soda lime compacted over the last 50 years; measurement and documentation of the background beta-gamma radiation level at the time and location of collection of each core, the highest beta-gamma level along the sediment portion of each core, and the highest beta-gamma level along the clay portion of each core; measurement and documentation of the length of the clay and of the sediment portion of each core; photographic documentation of each core; and replacement of each core in the impoundment.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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 $A_4$.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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)

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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)

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.).

  20. 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.

  1. 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 …?

  2. 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

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. 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)

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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...

  16. 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

  17. 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...

  18. 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.

  19. 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^{-...

  20. 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.

  1. 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

  2. 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.

  3. 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)

  4. 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.)

  5. 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.

  6. 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.

  7. Study and construction of a β-spectrometer of uniform axial magnetic field fitted with a β-γ coincidence selector. Study of the β spectra of 32P, 203Hg, 198Au. Measurement of the conversion coefficients of 203Ti and of 198Hg

    International Nuclear Information System (INIS)

    In the first part is given the principle of the beta spectrometer with uniform axial field using systematically the idea of caustics. The apparatus is described and its properties compared to those deduced from trajectory calculations. The β-ray and γ-ray detectors and the device for selecting coincidences with a 2 τ resolution of 5 nanoseconds are also presented. In the second part, the spectrometer is used for studying reference elements and the most accurate results are confirmed. The β spectrum of 60Co has a statistical form with an accuracy of 1 per cent; the maximum energy E0 is 316.5 ± 1.5 keV. That of the 7/2 + → 11/2 transition for 137Cs has a unique form, once forbidden. E0= 522 ± 3 keV. Conversion coefficients αk = 96 ± 1 X 10-3 αL + M + N = 20.9 ± 0.5 X 10-3. The two β spectra of 59Fe, separated by coincidence with the gamma, have the statistical form E0 = 462 ± 2 keV (55.1 + 0,3 per cent) and E1 = 275 ± 4 keV (44.9 ± 0.3 per cent). It is then verified whether the l selection rule is apparent in the shape of the phosphorus 32 beta spectrum. It is found in fact that it is not of statistical shape and its shape coefficient is determined. For a theoretical interpretation it is necessary to have better approximations than those generally used and this interpretation will not be unique. This work has also made it possible to show that the source contains a small proportion of 33P. The study of the 203Hg β spectrum followed by the 279 keV gamma spectrum is designed to determine the conversion coefficients. The interior spectrum of gold 198 is not of statistical shape either. The form coefficient is determined together with the conversion coefficients which are in slight disagreement with those calculated by Rose or Sliv. An interpretation of the spectrum is put forward which proposes an imperfect compensation for the various elements of the matrix. (author)

  8. 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.

  9. 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.

  10. 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

  11. Standardization of 64Cu and 68Ga by the 4π(PC)β-γ coincidence method and calibration of the ionization chamber.

    Science.gov (United States)

    Sahagia, M; Luca, A; Antohe, A; Ivan, C

    2012-09-01

    The paper treats the application of the 4π(PC)β-γ coincidence method for the standardization of the radionuclides (64)Cu and (68)Ga. The general coincidence equations are written. Two types of extrapolation were described and used in measurement: the positron-annihilation coincidence, and the counting of all emitted radiations; both methods are compared with respect to results, advantages and drawbacks. The impurities' content correction was applied. The standardized solutions were used to calibrate the ionization chamber CENTRONIC IG12/20A and to determine the gamma-rays emission intensities.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. Excitation and decay at Stark-mixed n = 2 states of hydrogen observed in an electron-photon coincidence experiment

    International Nuclear Information System (INIS)

    Measurements have been made of the Lyman-α intensity from Stark-mixed n = 2 states of hydrogen, using the electron-photon coincidence technique at an incident electron energy of 350 eV. The data are related to a combination of excitation amplitudes, including a term which depends on the relative phase of S and P amplitudes. Field-free measurements of lambda and R have also been made at this energy. Comparison is made with several theoretical results. (author)

  17. 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...

  18. 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, ...

  19. 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.

  20. 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.

  1. 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.

  2. Effects of beta/gamma radiation on nuclear waste glasses

    International Nuclear Information System (INIS)

    A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted β-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of β/γ radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author)

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Activity determination of a {sup 201}Tl solution by 4πβ-γ and sum-peak coincidence methods

    Energy Technology Data Exchange (ETDEWEB)

    Ruzzarin, Anelise; Lopes, Ricardo Tadeu, E-mail: aruzzarin@nuclear.ufrj.br [Coordenacao dos Cursos de Pos-Graduacao em Engenharia (LIN/PEN/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear. Lab. de Instrumentacao Nuclear; Silva, Monica A. L. da [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Iwahara, Akira; Silva, Ronaldo L. da; Filho, Octavio L.T.; Poledna, Roberto [Instituto de Radioprotecao e Dosimetria (LNMRI/IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes

    2015-07-01

    {sup 201}Tl is used in nuclear medicine in cardiac imaging for evaluating the injury level in cardiac muscle at rest and exercise. In this work the activity concentration of a {sup 201}Tl radioactive solution has been absolutely determined using the 4πβ-γ coincidence and sum-peak coincidence methods. The presence of {sup 202}Tl radioactive impurity that imposes some difficult in the activity measurements was taken into account in the measurements. In the sum-peak method a planar germanium detector was used. The half-lives were evaluated by the reference source method and the results obtained were (3.033 ± 0.004) d and (12.320 ± 0.163) d, respectively, for {sup 201}Tl and {sup 202}Tl. (author)

  13. Activity determination of a 201Tl solution by 4πβ-γ and sum-peak coincidence methods

    International Nuclear Information System (INIS)

    201Tl is used in nuclear medicine in cardiac imaging for evaluating the injury level in cardiac muscle at rest and exercise. In this work the activity concentration of a 201Tl radioactive solution has been absolutely determined using the 4πβ-γ coincidence and sum-peak coincidence methods. The presence of 202Tl radioactive impurity that imposes some difficult in the activity measurements was taken into account in the measurements. In the sum-peak method a planar germanium detector was used. The half-lives were evaluated by the reference source method and the results obtained were (3.033 ± 0.004) d and (12.320 ± 0.163) d, respectively, for 201Tl and 202Tl. (author)

  14. 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

  15. 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

  16. 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

  17. 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.

  18. Realistic PET Monte Carlo Simulation With Pixelated Block Detectors, Light Sharing, Random Coincidences and Dead-Time Modeling

    OpenAIRE

    Guérin, Bastein; Fakhri, Georges El

    2008-01-01

    We have developed and validated a realistic simulation of random coincidences, pixelated block detectors, light sharing among crystal elements and dead-time in 2D and 3D positron emission tomography (PET) imaging based on the SimSET Monte Carlo simulation software. Our simulation was validated by comparison to a Monte Carlo transport code widely used for PET modeling, GATE, and to measurements made on a PET scanner.

  19. Absolute Radiometric Calibration of Narrow-Swath Imaging Sensors with Reference to Non-Coincident Wide-Swath Sensors

    Science.gov (United States)

    McCorkel, Joel; Thome, Kurtis; Lockwood, Ronald

    2012-01-01

    An inter-calibration method is developed to provide absolute radiometric calibration of narrow-swath imaging sensors with reference to non-coincident wide-swath sensors. The method predicts at-sensor radiance using non-coincident imagery from the reference sensor and knowledge of spectral reflectance of the test site. The imagery of the reference sensor is restricted to acquisitions that provide similar view and solar illumination geometry to reduce uncertainties due to directional reflectance effects. Spectral reflectance of the test site is found with a simple iterative radiative transfer method using radiance values of a well-understood wide-swath sensor and spectral shape information based on historical ground-based measurements. At-sensor radiance is calculated for the narrow-swath sensor using this spectral reflectance and atmospheric parameters that are also based on historical in situ measurements. Results of the inter-calibration method show agreement on the 2 5 percent level in most spectral regions with the vicarious calibration technique relying on coincident ground-based measurements referred to as the reflectance-based approach. While the variability of the inter-calibration method based on non-coincident image pairs is significantly larger, results are consistent with techniques relying on in situ measurements. The method is also insensitive to spectral differences between the sensors by transferring to surface spectral reflectance prior to prediction of at-sensor radiance. The utility of this inter-calibration method is made clear by its flexibility to utilize image pairings with acquisition dates differing in excess of 30 days allowing frequent absolute calibration comparisons between wide- and narrow-swath sensors.

  20. 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.

  1. 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.

  2. 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

  3. 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)

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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)

  9. 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.

  10. 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.

  11. 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

  12. Using anisotropies in prompt fission neutron coincidences to assess the neutron multiplication of highly multiplying subcritical plutonium assemblies

    Science.gov (United States)

    Mueller, J. M.; Mattingly, J.

    2016-07-01

    There is a significant and well-known anisotropy between the prompt neutrons emitted from a single fission event; these neutrons are most likely to be observed at angles near 0° or 180° relative to each other. However, the propagation of this anisotropy through different generations of a fission chain reaction has not been previously studied. We have measured this anisotropy in neutron-neutron coincidences from a subcritical highly-multiplying assembly of plutonium metal. The assembly was a 4.5 kg α-phase plutonium metal sphere composed of 94% 239Pu and 6% 240Pu by mass. Data were collected using two EJ-309 liquid scintillators and two EJ-299 plastic scintillators. The angular distribution of neutron-neutron coincidences was measured at 90° and 180° and found to be largely isotropic. Simulations were performed using MCNPX-PoliMi of similar plutonium metal spheres of varying sizes and a correlation between the neutron multiplication of the assembly and the anisotropy of neutron-neutron coincidences was observed. In principle, this correlation could be used to assess the neutron multiplication of an unknown assembly.

  13. The influence of radiation and light on Ps formation in PMMA and PE studied by coincidence Doppler-broadening spectroscopy

    CERN Document Server

    Suzuki, T; Shantarovich, V; Kondo, K; Hamada, E; Matso, M; Ma Li; Ito, Y

    2003-01-01

    Using two Ge detectors, the high-resolution Doppler-broadening energy spectra of positron annihilation gamma rays has been obtained by measuring the coincidences of the two photons. Light bleaching and oxygen effects on positron annihilation were investigated in this way. A large enhancement of the high-momentum part of the coincidence Doppler spectra was observed in poly(methylmethacrylate) (PMMA), which contains oxygen atoms in the polymer structure. Bleaching experiments in PMMA and in copolymer ethylene-methylmethacrylate EMMA (LDPE+MMA 3 mol%) have demonstrated that the enhancement effect may be due to the trapping of positrons by the polar -C sup + 6-O sup - groups, followed by positron annihilation with the electrons belonging to oxygen.

  14. A search for double-electron capture in 74Se using coincidence/anticoincidence gamma-ray spectrometry

    CERN Document Server

    Jeskovsky, M; Kovacik, A; Povinec, P P; Puppe, P; Stanicek, J; Sykora, I; Simkovic, F; Thies, J H

    2015-01-01

    Evaluation of single, coincidence and anticoincidence gamma-ray spectrometry methods has been carried out with the aim to search for double-electron capture in 74Se. This process is unique, because there is probability for transition to the 2+ excited state in 74Ge (1204 keV), and de-excitation through two gamma-quanta cascade with energies of 595.9 keV and 608.4 keV. Long-term measurements with anticosmic shielded HPGe spectrometer and the coincidence HPGe-NaI(Tl) spectrometer did not show any evidence for the double-electron capture in 74Se. The best limit for the half-life of the double electron capture in 74Se (both for the neutrinoless and two neutrino processes) was estimated to be >1.5x10E19 years.

  15. Synchrotron-based double imaging photoelectron/photoion coincidence spectroscopy of radicals produced in a flow tube: OH and OD

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Gustavo A.; Tang, Xiaofeng; Gil, Jean-François; Nahon, Laurent [Synchrotron SOLEIL, L’Orme des Merisiers, St. Aubin, BP 48, 91192 Gif sur Yvette (France); Ward, Michael; Batut, Sebastien; Fittschen, Christa [PC2A, Université de Lille 1, UMR CNRS-USTL 8522, Cité Scientifique Bât. C11, F-59655 Villeneuve d’Ascq (France); Taatjes, Craig A.; Osborn, David L. [Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969 (United States); Loison, Jean-Christophe [ISM, Université Bordeaux 1, CNRS, 351 cours de la Libération, 33405 Talence Cedex (France)

    2015-04-28

    We present a microwave discharge flow tube coupled with a double imaging electron/ion coincidence device and vacuum ultraviolet (VUV) synchrotron radiation. The system has been applied to the study of the photoelectron spectroscopy of the well-known radicals OH and OD. The coincidence imaging scheme provides a high selectivity and yields the spectra of the pure radicals, removing the ever-present contributions from excess reactants, background, or secondary products, and therefore obviating the need for a prior knowledge of all possible byproducts. The photoelectron spectra encompassing the X{sup 3}Σ{sup −} ground state of the OH{sup +} and OD{sup +} cations have been extracted and the vibrational constants compared satisfactorily to existing literature values. Future advantages of this approach include measurement of high resolution VUV spectroscopy of radicals, their absolute photoionization cross section, and species/isomer identification in chemical reactions as a function of time.

  16. Participation of the ARN in the program of the EML-US DOE for the evaluation of quality of the radiochemistry measurements; Participacion de la ARN en el programa del EML-USDOE para la evaluacion de calidad de las mediciones radioquimicas

    Energy Technology Data Exchange (ETDEWEB)

    Equillor, Hugo; Grinman, Ana; Serdeiro, Nelida; Fernandez, Jorge; Gavini, Ricardo; Bonino, Nestor; Lewis, Cecilia; Palacios, Miguel; Diodati, Jorge; Medici, Marcela [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina)

    2001-07-01

    The Autoridad Regulatoria Nuclear (ARN), Republica Argentina participates since 1995 in the Quality Assessment Program carried out by the Environmental Measurements Laboratory, United States Department Of Energy (US DOE). The aim of this participation is to assess the quality of the measurements that ARN realises routinely. The program involves alpha, beta, gamma emitters radionuclides determinations in four kinds of matrixes: water, filter, vegetation and soil. In the present work the results of the ARN participations respect to 1998-2000 period, are detailed and analyzed statistically. The results are compared with the total of the laboratories. (author)

  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. Measurement of time-dependent CP asymmetries in B0->D(*)+-pi-+ and B0->D+-rho-+ decays

    CERN Document Server

    Aubert, B; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Pappagallo, M; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Best, D S; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yu, K; Todyshev; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Del Re, D; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Andreassen, R; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Nogowski, R; Petzold, A; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Grenier, P; Latour, E; Thiebaux, C; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Gaillard, J R; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Chai, X; Charles, M J; Mader, W F; Mallik, U; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Oyanguren, A; Petersen, T C; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Brown, C L; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Kelly, M P; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Stängle, H; Willocq, S Y; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Potter, C T; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, Gallieno; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Galeazzi, F; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Chauveau, J; David, P; Del Buono, L; La Vaissière, C de; Hamon, O; Hartfiel, B L; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Walsh, J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; Mayer, B; Vasseur, G; Yéche, C; Zito, M; Park, W; Purohit, M V; Weidemann, A W; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Boyarski, A M; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Field, R C; Glanzman, T; Gowdy, S J; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Vitale, L; Azzolini, V; Martínez-Vidal, F; Panvini, R S; Banerjee, S; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R V; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Graham, M T; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mellado, B; Mihályi, A; Mohapatra, A K; Pan, Y; Pierini, M; Prepost, R; Tan, P; Wu, S L; Yu, Z; Neal, H

    2006-01-01

    We present updated results on time-dependent CP asymmetries in fully reconstructed B0->D(*)+-pi-+ and B0->D+-rho-+ decays in approximately 232 million Y(4S)->BBbar events collected with the BaBar detector at the PEP-II asymmetric-energy B factory at SLAC. From a time-dependent maximum likelihood fit we obtain for the parameters related to the CP violation angle 2beta+gamma: a^{D\\pi} = -0.010 +/- 0.023 +/- 0.007, c_{\\rm lep}^{D\\pi} = -0.033 +/- 0.042 +/- 0.012, a^{D^*\\pi} = -0.040 +/- 0.023 +/- 0.010, c_{\\rm lep}^{D^*\\pi} = 0.049 +/- 0.042 +/- 0.015, a^{D\\rho} = -0.024 +/- 0.031 +/- 0.009, c_{\\rm lep}^{D\\rho} = -0.098 +/- 0.055 +/- 0.018, where the first error is statistical and the second is systematic. Using other measurements and theoretical assumptions, we interpret the results in terms of the angles of the Cabibbo-Kobayashi-Maskawa unitarity triangle and find |sin(2beta+gamma)| > 0.64 (0.40) at 68% (90%) confidence level.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. Variance estimation in neutron coincidence counting using the bootstrap method

    Energy Technology Data Exchange (ETDEWEB)

    Dubi, C., E-mail: chendb331@gmail.com [Physics Department, Nuclear Research Center of the Negev, P.O.B. 9001 Beer Sheva (Israel); Ocherashvilli, A.; Ettegui, H. [Physics Department, Nuclear Research Center of the Negev, P.O.B. 9001 Beer Sheva (Israel); Pedersen, B. [Nuclear Security Unit, Institute for Transuranium Elements, Via E. Fermi, 2749 JRC, Ispra (Italy)

    2015-09-11

    In the study, we demonstrate the implementation of the “bootstrap” method for a reliable estimation of the statistical error in Neutron Multiplicity Counting (NMC) on plutonium samples. The “bootstrap” method estimates the variance of a measurement through a re-sampling process, in which a large number of pseudo-samples are generated, from which the so-called bootstrap distribution is generated. The outline of the present study is to give a full description of the bootstrapping procedure, and to validate, through experimental results, the reliability of the estimated variance. Results indicate both a very good agreement between the measured variance and the variance obtained through the bootstrap method, and a robustness of the method with respect to the duration of the measurement and the bootstrap parameters.

  7. Intrinsic coincident linear polarimetry using stacked organic photovoltaics.

    Science.gov (United States)

    Roy, S Gupta; Awartani, O M; Sen, P; O'Connor, B T; Kudenov, M W

    2016-06-27

    Polarimetry has widespread applications within atmospheric sensing, telecommunications, biomedical imaging, and target detection. Several existing methods of imaging polarimetry trade off the sensor's spatial resolution for polarimetric resolution, and often have some form of spatial registration error. To mitigate these issues, we have developed a system using oriented polymer-based organic photovoltaics (OPVs) that can preferentially absorb linearly polarized light. Additionally, the OPV cells can be made semitransparent, enabling multiple detectors to be cascaded along the same optical axis. Since each device performs a partial polarization measurement of the same incident beam, high temporal resolution is maintained with the potential for inherent spatial registration. In this paper, a Mueller matrix model of the stacked OPV design is provided. Based on this model, a calibration technique is developed and presented. This calibration technique and model are validated with experimental data, taken with a cascaded three cell OPV Stokes polarimeter, capable of measuring incident linear polarization states. Our results indicate polarization measurement error of 1.2% RMS and an average absolute radiometric accuracy of 2.2% for the demonstrated polarimeter. PMID:27410627

  8. Intrinsic coincident linear polarimetry using stacked organic photovoltaics.

    Science.gov (United States)

    Roy, S Gupta; Awartani, O M; Sen, P; O'Connor, B T; Kudenov, M W

    2016-06-27

    Polarimetry has widespread applications within atmospheric sensing, telecommunications, biomedical imaging, and target detection. Several existing methods of imaging polarimetry trade off the sensor's spatial resolution for polarimetric resolution, and often have some form of spatial registration error. To mitigate these issues, we have developed a system using oriented polymer-based organic photovoltaics (OPVs) that can preferentially absorb linearly polarized light. Additionally, the OPV cells can be made semitransparent, enabling multiple detectors to be cascaded along the same optical axis. Since each device performs a partial polarization measurement of the same incident beam, high temporal resolution is maintained with the potential for inherent spatial registration. In this paper, a Mueller matrix model of the stacked OPV design is provided. Based on this model, a calibration technique is developed and presented. This calibration technique and model are validated with experimental data, taken with a cascaded three cell OPV Stokes polarimeter, capable of measuring incident linear polarization states. Our results indicate polarization measurement error of 1.2% RMS and an average absolute radiometric accuracy of 2.2% for the demonstrated polarimeter.

  9. 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.

  10. Calculation of extrapolation curves in the 4π(LS)β-γ coincidence technique with the Monte Carlo code Geant4.

    Science.gov (United States)

    Bobin, C; Thiam, C; Bouchard, J

    2016-03-01

    At LNE-LNHB, a liquid scintillation (LS) detection setup designed for Triple to Double Coincidence Ratio (TDCR) measurements is also used in the β-channel of a 4π(LS)β-γ coincidence system. This LS counter based on 3 photomultipliers was first modeled using the Monte Carlo code Geant4 to enable the simulation of optical photons produced by scintillation and Cerenkov effects. This stochastic modeling was especially designed for the calculation of double and triple coincidences between photomultipliers in TDCR measurements. In the present paper, this TDCR-Geant4 model is extended to 4π(LS)β-γ coincidence counting to enable the simulation of the efficiency-extrapolation technique by the addition of a γ-channel. This simulation tool aims at the prediction of systematic biases in activity determination due to eventual non-linearity of efficiency-extrapolation curves. First results are described in the case of the standardization (59)Fe. The variation of the γ-efficiency in the β-channel due to the Cerenkov emission is investigated in the case of the activity measurements of (54)Mn. The problem of the non-linearity between β-efficiencies is featured in the case of the efficiency tracing technique for the activity measurements of (14)C using (60)Co as a tracer.

  11. A coincidence method for the simultaneous measurement of the photoionization of several masses

    International Nuclear Information System (INIS)

    This study was made in the working team Ding (Hahn-Meitner Institute Berlin) in the framework of photoionization experiments on Van-der-Waals clusters. The experiments were performed at the Berlin electron storage ring (BESSY). In a molecular-beam source clusters are produced and ionized by monochromatic light. The mass of the ions arising hereby is determined with a time-of-flight mass spectrometer. Within this thesis a method and an electronic device was developed, by which it is made possible to gather simultaneously the wave-length dependence of several masses. (orig.) With 27 refs

  12. STUDY OF THE CONTINUUM IN HEAVY-ION INELASTIC SPECTRA BY LIGHT PARTICLE COINCIDENCE MEASUREMENTS

    NARCIS (Netherlands)

    SCARPACI, JA; BLUMENFELD, Y; CHOMAZ, P; FRASCARIA, N; GARRON, JP; ROYNETTE, JC; SUOMIJARVI, T; ALAMANOS, N; GILLIBERT, A; VANDERWOUDE, A

    1991-01-01

    The continuum in heavy ion inelastic spectra contains, in addition to the excitation of target nucleus states, contributions from pick-up break-up and knock out reactions. In the case of the Ca-40 + Ca-40 collision at 50 MeV/N these contributions are separated and their relative importance assessed

  13. Signature of pre-equilibrium-emission: yield-ratio measurement in particle-γ coincidence

    International Nuclear Information System (INIS)

    In the present work, forward peaked angular distribution characteristics of pre-equilibrium-particles have been used to probe the pre-equilibrium process. In such a case, the probability of light nuclear particles emitted in forward cone may be relatively large as compared to that emitted in backward cone

  14. Radioxenon detector calibration spike production and delivery systems

    Energy Technology Data Exchange (ETDEWEB)

    Foxe, Michael P.; Cameron, Ian M.; Cooper, Matthew W.; Haas, Derek A.; Hayes, James C.; Kriss, Aaron A.; Lidey, Lance S.; Mendez, Jennifer M.; Prinke, Amanda M.; Riedmann, Robin A.

    2016-03-01

    Abstract Beta-Gamma coincidence radioxenon detectors must be calibrated for each of the four-radioxenon isotopes (135Xe, 133Xe, 133mXe, and 131mXe). Without a proper calibration, there is potential for the misidentification of the amount of each isotope detected. It is important to accurately determine the amount of each radioxenon isotope, as the ratios can be used to distinguish between an anthropogenic source and a nuclear explosion. We have developed a xenon calibration system (XeCalS) that produces calibration spikes of known activity and pressure for field calibration of detectors. The activity concentrations of these calibration spikes are measured using a beta-gamma coincidence detector and a high purity germanium (HPGe) detector. We will present the results from the development and commissioning of XeCalS, along with the future plans for a portable spike implementation system.

  15. 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...

  16. A geometric solution to the coincidence problem, and the size of the landscape as the origin of hierarchy.

    Science.gov (United States)

    Bousso, Raphael; Freivogel, Ben; Leichenauer, Stefan; Rosenhaus, Vladimir

    2011-03-11

    Weinberg's seminal prediction of the cosmological constant relied on a provisional method for regulating eternal inflation which has since been put aside. We show that a modern regulator, the causal patch, improves agreement with observation, removes many limiting assumptions, and yields additional powerful results. Without assuming necessary conditions for observers such as galaxies or entropy production, the causal patch measure predicts the coincidence of vacuum energy and present matter density. Their common scale, and thus the enormous size of the visible Universe, originates in the number of metastable vacua in the landscape.

  17. Contested spatial coincidence of conservation and mining efforts in Madagascar

    Directory of Open Access Journals (Sweden)

    Anjara Andriamanalina

    2007-12-01

    Full Text Available Mining appears to represent an important threat to conservation efforts in Madagascar. Expanding mining activities on the island have the potential to provide revenue for development and conservation efforts, but also pose a potential threat to conservation efforts on the island due to the spatial distribution and extent of mining concessions and the environmental impacts that mines often cause. By measuring the extent of overlap of permitted mining concessions with protected areas, potential protected areas, and mining - exclusion zones on the island, we assessed potential effects of mining on terrestrial conservation and evaluated the success of the governing institutions in limiting that impact. Permitted mining areas in 2006 overlapped with protected areas, potential protected areas, and mining - exclusion zones on the island. Mining concession areas overlapped with 33 % of surface area planned for protection in 2005, 21 % of surface area planned for protection in 2006, and 12 % of the surface area from which mining was to be legally excluded. Total permitted area and area of overlap with conservation areas increased between 2005 and 2006 despite efforts in 2004 to limit such overlap. Changes in the mining permitting and regulation could improve prospects for limiting the impact of mining on biodiversity conservation on the island.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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....

  3. 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

  4. A spectrometer for lifetime determination by β-γ-γ delayed coincidence technique at KUR-ISOL

    Science.gov (United States)

    Kojima, Y.; Hayashi, H.; Shibata, M.; Endo, S.; Shizuma, K.; Taniguchi, A.

    2011-12-01

    A new spectrometer for measuring nuclear level lifetimes has been installed at the on-line isotope separator of the Kyoto University Reactor. The spectrometer consists of a LaBr3(Ce), Ge and a thin plastic scintillation detector, and the lifetimes are determined using a β-γ-γ delayed coincidence technique. In this study, the LaBr3 detector was used to obtain time spectra, whereas the Ge detector was used to select a desired γ branch. The energy dependence of the time resolutions was measured down to a photon energy of 100 keV. The lifetimes measured for the excited levels in 93Sr and 148Ce agree well with their evaluated values. The lifetime of 8.5(5) ns was obtained for the first time for the 98.2 keV level in 148Pr.

  5. 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

  6. Elaboration of supports for beta emitting sources (with vyns); Elaboracion de soportes para fuentes emisoras beta (con vyns)

    Energy Technology Data Exchange (ETDEWEB)

    Cortes P, A.; Torre O, J. De la; Tejera R, A.; Becerril V, A.; Bribiesca S, L

    1990-04-15

    The Laboratory of Radioactive patterns account with a 4 {pi}{beta}-{gamma} coincidence system of recent acquisition with which absolute measures of radioactive activity with uncertainties of the order of 0.1% can be made. Since the coincidence method for the activity measure consists on detecting to the particle and the photon corresponding to oneself nuclear disintegration, it is necessary to elaborate special radioactive sources on thin supports, in order to allowing the maximum possible fluence of {beta} particles ({approx} 100%). This work a technique for the elaboration of these sources and for the measure of the thickness of the walls of the support is presented. (Author)

  7. 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

  8. Determination iodine in biological materials using instrumental neutron activation and anti-coincidence gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.H.; Chatt, A. [Dalhousie University, Halifax, Nova Scotia (Canada). Radiochemistry Research Laboratory

    1997-10-01

    Iodine is an element of interest in nutritional research. Its lower limit of safe and adequate daily dietary intake for adults varies between 150 and 200 micrograms per day. In the present study, an epithermal instrumental neutron activation analysis (EINAA) method in conjunction with anti-coincidence counting has been developed for the determination of ppb levels of iodine in individual food items. Typically 200-300 mg of a sample are irradiated for 10 or 20 minutes at the Dalhousie University SLOWPOKE-2 reactor in an epithermal flux of 1x10{sup 11} n cm{sup -2} s{sup -1}, followed by 1 min decay and then counting for 30 min. The 443-keV gamma-ray of {sup 128}I is used for measuring iodine content by anti-coincidence counting. The anti-coincidence spectrometer consists of a 25% HPGe detector surrounded by a 10``x10`` NaI(TI) annulus and a 3``x3`` NaI(TI) plug. This system has a peak-to-Compton ratio of about 650 to 1 for the 661.6-keV photopeak of {sup 137}Cs. The Compton background resulting from the scattering of many gamma-rays of energies higher than 443 keV can be reduced by a factor of about 4 using anti-coincidence counting compared to conventional counting. The detection limit for iodine can be improved by a factor of 2 to 5 depending on the sample matrix, dead time, position of the annulus and counting geometry among several other factors.The lowest detection limit of 5 ppb can be achieved for low-salt foods. This limit is comparable to that obtained by a preconcentration NAA (PNAA) method. However, a detection limit of 20 ppb is more realistic for samples containing high amounts of Na, Cl and Al. The results obtained for many reference materials are in good agreement with the certified values and those reported by the PNAA method. Details of the methods and results will be reported 6 refs., 2 tabs.

  9. Determination iodine in biological materials using instrumental neutron activation and anti-coincidence gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Iodine is an element of interest in nutritional research. Its lower limit of safe and adequate daily dietary intake for adults varies between 150 and 200 micrograms per day. In the present study, an epithermal instrumental neutron activation analysis (EINAA) method in conjunction with anti-coincidence counting has been developed for the determination of ppb levels of iodine in individual food items. Typically 200-300 mg of a sample are irradiated for 10 or 20 minutes at the Dalhousie University SLOWPOKE-2 reactor in an epithermal flux of 1x1011 n cm-2 s-1, followed by 1 min decay and then counting for 30 min. The 443-keV gamma-ray of 128I is used for measuring iodine content by anti-coincidence counting. The anti-coincidence spectrometer consists of a 25% HPGe detector surrounded by a 10''x10'' NaI(TI) annulus and a 3''x3'' NaI(TI) plug. This system has a peak-to-Compton ratio of about 650 to 1 for the 661.6-keV photopeak of 137Cs. The Compton background resulting from the scattering of many gamma-rays of energies higher than 443 keV can be reduced by a factor of about 4 using anti-coincidence counting compared to conventional counting. The detection limit for iodine can be improved by a factor of 2 to 5 depending on the sample matrix, dead time, position of the annulus and counting geometry among several other factors.The lowest detection limit of 5 ppb can be achieved for low-salt foods. This limit is comparable to that obtained by a preconcentration NAA (PNAA) method. However, a detection limit of 20 ppb is more realistic for samples containing high amounts of Na, Cl and Al. The results obtained for many reference materials are in good agreement with the certified values and those reported by the PNAA method. Details of the methods and results will be reported

  10. Monte Carlo calculation of the efficiency calibration curve and coincidence-summing corrections in low-level gamma-ray spectrometry using well-type HPGe detectors

    International Nuclear Information System (INIS)

    Well-type high-purity germanium (HPGe) detectors are well suited to the analysis of small amounts of environmental samples, as they can combine both low background and high detection efficiency. A low-background well-type detector is installed in the Modane underground Laboratory. In the well geometry, coincidence-summing effects are high and make the construction of the full energy peak efficiency curve a difficult task with an usual calibration standard, especially in the high energy range. Using the GEANT code and taking into account a detailed description of the detector and the source, efficiency curves have been modelled for several filling heights of the vial. With a special routine taking into account the decay schemes of the radionuclides, corrections for coincidence-summing effects that occur when measuring samples containing 238U, 232Th or 134Cs have been computed. The results are found to be in good agreement with the experimental data. It is shown that triple coincidences effect on counting losses accounts for 7-15% of pair coincidences effect in the case of 604 and 796 keV lines of 134Cs

  11. Efficiency calibration and coincidence summing correction for large arrays of NaI(Tl) detectors in soccer-ball and castle geometries

    Energy Technology Data Exchange (ETDEWEB)

    Anil Kumar, G., E-mail: anilg@tifr.res.i [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India); Mazumdar, I.; Gothe, D.A. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)

    2009-11-21

    Efficiency calibration and coincidence summing correction have been performed for two large arrays of NaI(Tl) detectors in two different configurations. They are, a compact array of 32 conical detectors of pentagonal and hexagonal shapes in soccer-ball geometry and an array of 14 straight hexagonal NaI(Tl) detectors in castle geometry. Both of these arrays provide a large solid angle of detection, leading to considerable coincidence summing of gamma rays. The present work aims to understand the effect of coincidence summing of gamma rays while determining the energy dependence of efficiencies of these two arrays. We have carried out extensive GEANT4 simulations with radio-nuclides that decay with a two-step cascade, considering both arrays in their realistic geometries. The absolute efficiencies have been simulated for gamma energies from 700 to 2800 keV using four different double-photon emitters, namely, {sup 60}Co, {sup 46}Sc, {sup 94}Nb and {sup 24}Na. The efficiencies so obtained have been corrected for coincidence summing using the method proposed by Vidmar et al. . The simulations have also been carried out for the same energies assuming mono-energetic point sources, for comparison. Experimental measurements have also been carried out using calibrated point sources of {sup 137}Cs and {sup 60}Co. The simulated and the experimental results are found to be in good agreement. This demonstrates the reliability of the correction method for efficiency calibration of two large arrays in very different configurations.

  12. Remote preparation of complex spatial states of single photons and verification by two-photon coincidence experiment.

    Science.gov (United States)

    Kang, Yoonshik; Cho, Kiyoung; Noh, Jaewoo; Vitullo, Dashiell L P; Leary, Cody; Raymer, M G

    2010-01-18

    We propose and provide experimental evidence in support of a theory for the remote preparation of a complex spatial state of a single photon. An entangled two-photon source was obtained by spontaneous parametric down-conversion, and a double slit was placed in the path of the signal photon as a scattering object. The signal photon was detected after proper spatial filtering so that the idler photon was prepared in the corresponding single-photon state. By using a two-photon coincidence measurement, we obtained the Radon transform, at several longitudinal distances, of the single-photon Wigner distribution function modified by the double slit. The experimental results are consistent with the idler photon being in a pure state. An inverse Radon transformation can, in principle, be applied to the measured data to reconstruct the modified single-photon Wigner function, which is a complete representation of the amplitude and phase structure of the scattering object.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Non-proportionality study of CaMoO4 and GAGG:Ce scintillation crystals using Compton coincidence technique.

    Science.gov (United States)

    Kaewkhao, J; Limkitjaroenporn, P; Chaiphaksa, W; Kim, H J

    2016-09-01

    In this study, the CCT technique and nuclear instrument module (NIM) setup for the measurements of coincidence electron energy spectra of calcium molybdate (CaMoO4) and cerium doped gadolinium aluminium gallium garnet (Gd3Al2Ga3O12:Ce or GAGG:Ce) scintillation crystals were carried out. The (137)Cs irradiated gamma rays with an energy (Eγ) of 662keV was used as a radioactive source. The coincidence electron energy spectra were recorded at seven scattering angles of 30°-120°. It was found that seven corresponding electron energies were in the range of 100.5-435.4keV. The results show that, for all electron energies, the electron energy peaks of CaMoO4 crystal yielded higher number of counts than those of GAGG:Ce crystal. The electron energy resolution, the light yield and non-proportionality were also determined. It was found that the energy resolutions are inverse proportional to the square root of electron energy for both crystals. Furthermore, the results show that the light yield of GAGG:Ce crystal is much higher than that of CaMoO4 crystal. It was also found that both CaMoO4 and GAGG:Ce crystals demonstrated good proportional property in the electron energy range of 260-435.4keV. PMID:27423926

  20. Study of rare neutron induced processes and coincidence analyses to identify and reduce background contributions in the COBRA experiment

    International Nuclear Information System (INIS)

    The aim of the COBRA experiment is the observation of neutrinoless double-beta decay, primarily of the isotope 116Cd. The applied semiconductor detectors of cadmium zinc telluride that are 90% to be enriched enable both the detection and the source of this decay. The half-lives of decays of this kind are expected in the range of more than 1026 years. Therefore, the reduction of contributions to the background is of decisive importance. The main subjects of this work are, on the one hand, the time synchronization of the data, which provides the basis for coincidence analysis. This analysis method has access not only to identification of contributions to the background, but also to observe decays involving positron annihilation and decays into excited states. In this study, the intrinsic detector contamination of some decay products of 238U and 232Th was measured and sensitivities to the half-lives of the decays like 120Te and 128Te in each case to the first excited state of daughter products are given. On the other hand, qualitative studies on the importance of neutrons in the COBRA experiment were conducted. These have shown that fast neutrons, thus with energies greater than 10 keV, only result in an insignificant contribution to the background for the detection of neutrinoless double-beta decay of the 116Cd. Previous studies have also shown that the thermal neutron flux can be in situ determined by coincidence analysis.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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)

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Solid-phase radioimmunoassay for measurement of circulating antibody titres to wheat gliadin and its subfractions in patients with adult coeliac disease

    Energy Technology Data Exchange (ETDEWEB)

    Ciclitira, P.J.; Ellis, H.J. (Guy' s Hospital, London (UK)); Evans, D.J. (Hammersmith Hospital, London (UK))

    1983-08-26

    A solid-phase radioimmunoassay for the measurement of circulating antibody titres to wheat gliadin is described. Using this assay, the authors have measured antibody titres to unfractionated gliadin in normal healthy controls, in coeliac patients on a gluten-free or a normal diet, and in patients with ulcerative colitis and Crohn's disease. High titres of antibodies to unfractionated gliadin were observed only in the patients with untreated coeliac disease. Antibody titres to ..cap alpha.., ..beta.., ..gamma.. and ..omega.. gliadin subfractions were measured in patients with untreated coeliac disease and compared with titres in normal controls. Patients with untreated coeliac disease had higher antibody titres to the gliadin subfractions. No specific pattern of circulating antibody titres to gliadin subfractions was observed in the untreated coeliac patients which would provide a diagnostic profile. These results suggest shared antigenicity between the gliadin subfractions.

  20. International comparison CCRI(II)-S7 on the analysis of uncertainty budgets for 4πβγ coincidence counting

    International Nuclear Information System (INIS)

    Detailed uncertainty reporting is imperative for proficiency tests and comparison exercises because uncertainties need to be comparable and trusted by all the participants. Even though participants do their best to follow the Guide to the Expression of Uncertainty in Measurement, ambiguities and divergences about uncertainty evaluation remain. Consequently, to analyze the situation, the CCRI(II) Uncertainties Working Group proposed a comparison exercise (CCRI(II)-S7) about the uncertainty evaluation of a relatively simple primary activity measurement: the standardization of a 60Co source by coincidence counting. To be able to understand how various NMIs calculate coincidence counting uncertainties, our study focused on two of the dominant uncertainty components commonly quoted for 4πβγ coincidence counting in the International Reference System (SIR) submissions and Key Comparison exercises: efficiency-extrapolation and weighing. Participants from twelve different laboratories were sent the same set of measurement data from the analysis of a 60Co solution standardized at the National Physical Laboratory (NPL). Our study demonstrated the extent of the different interpretations of the uncertainty components. Some factors causing large discrepancies were isolated and are discussed. Further studies of other techniques using a similar approach would be beneficial for the metrology community. (authors)

  1. A search for double-electron capture of {sup 74}Se to excited levels using coincidence/anticoincidence gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ješkovský, M. [Comenius University, Faculty of Mathematics, Physics and Informatics, Department of Nuclear Physics and Biophysics, 84248 Bratislava (Slovakia); Frekers, D. [Institut für Kernphysik, Westfälische Wilhelms Universität, Münster (Germany); Kováčik, A. [Comenius University, Faculty of Mathematics, Physics and Informatics, Department of Nuclear Physics and Biophysics, 84248 Bratislava (Slovakia); Povinec, P.P., E-mail: povinec@fmph.uniba.sk [Comenius University, Faculty of Mathematics, Physics and Informatics, Department of Nuclear Physics and Biophysics, 84248 Bratislava (Slovakia); Puppe, P. [Institut für Kernphysik, Westfälische Wilhelms Universität, Münster (Germany); Staníček, J.; Sýkora, I. [Comenius University, Faculty of Mathematics, Physics and Informatics, Department of Nuclear Physics and Biophysics, 84248 Bratislava (Slovakia); Šimkovic, F. [Comenius University, Faculty of Mathematics, Physics and Informatics, Department of Nuclear Physics and Biophysics, 84248 Bratislava (Slovakia); Joint Institute for Nuclear Research, Dubna, Moscow Region (Russian Federation); Thies, J.H. [Institut für Kernphysik, Westfälische Wilhelms Universität, Münster (Germany)

    2015-09-21

    Evaluation of single, coincidence and anticoincidence gamma-ray spectrometry methods has been carried out with the aim to search for double-electron capture of {sup 74}Se to excited states. This process is unique, because there is probability for transition to the 2{sup +} excited state in {sup 74}Ge (1204 keV), and de-excitation through two gamma-quanta cascade with energies of 595.9 keV and 608.4 keV. Long-term measurements with an anticosmic shielded HPGe (high purity Ge) spectrometer and a coincidence HPGe–NaI(Tl) spectrometer did not show any evidence for the double-electron capture in {sup 74}Se. The best limit for the half-life of the double electron capture in {sup 74}Se (both for the neutrinoless and two neutrino processes) was estimated to be >1.5×10{sup 19} yr.

  2. 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.

  3. 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.

  4. 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)

  5. 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...

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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...

  15. '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)

  16. 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.

  17. 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...

  18. 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...

  19. 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...

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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)

  7. 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...

  8. A scattered-electron-cascaded-photon coincidence experiment on the electron impact excitation of the 32Dsub(j) states of atomic hydrogen

    International Nuclear Information System (INIS)

    Out of the scattering plane angular correlation measurements have been made of the Lsub(α) radiation arising from the cascade of the 32Dsub(j) states of atomic hydrogen to 22Psub(j) detected in coincidence with electrons with n = 3 energy loss. The experimental results, together with previous measurements in this laboratory, constitute a complete determination of all the second-order state multipoles characterizing the excitation. Data are presented at incident energies of 54.4 and 100 eV and at electron scattering angles θsub(c) of 20 and 25 degrees. (author)

  9. Scattered-electron-cascaded-photon coincidence experiment on the electron impact excitation of the 3/sup 2/Dsub(j) states of atomic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Chwirot, S.; Slevin, J.

    1987-08-14

    Out of the scattering plane angular correlation measurements have been made of the Lsub(..cap alpha..) radiation arising from the cascade of the 3/sup 2/Dsub(j) states of atomic hydrogen to 2/sup 2/Psub(j) detected in coincidence with electrons with n = 3 energy loss. The experimental results, together with previous measurements in this laboratory, constitute a complete determination of all the second-order state multipoles characterizing the excitation. Data are presented at incident energies of 54.4 and 100 eV and at electron scattering angles thetasub(c) of 20 and 25 degrees.

  10. Time change, jumping measure and Feller measure

    OpenAIRE

    He, Ping

    2007-01-01

    In this paper, we shall investigate some potential theory for time change of Markov processes. Under weak duality, it is proved that the jumping measure and Feller measure are actually independent of time change, and the jumping measure of a time changed process induced by a PCAF supported on $V$ coincides with the sum of the Feller measure on $V$ and the trace of the original jumping measure on $V$.

  11. Measuring $\

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Jessica Sarah [Univ. of Cambridge (United Kingdom)

    2011-01-01

    The MINOS Experiment consists of two steel-scintillator calorimeters, sampling the long baseline NuMI muon neutrino beam. It was designed to make a precise measurement of the ‘atmospheric’ neutrino mixing parameters, Δm2 atm. and sin2 (2 atm.). The Near Detector measures the initial spectrum of the neutrino beam 1km from the production target, and the Far Detector, at a distance of 735 km, measures the impact of oscillations in the neutrino energy spectrum. Work performed to validate the quality of the data collected by the Near Detector is presented as part of this thesis. This thesis primarily details the results of a vμ disappearance analysis, and presents a new sophisticated fitting software framework, which employs a maximum likelihood method to extract the best fit oscillation parameters. The software is entirely decoupled from the extrapolation procedure between the detectors, and is capable of fitting multiple event samples (defined by the selections applied) in parallel, and any combination of energy dependent and independent sources of systematic error. Two techniques to improve the sensitivity of the oscillation measurement were also developed. The inclusion of information on the energy resolution of the neutrino events results in a significant improvement in the allowed region for the oscillation parameters. The degree to which sin2 (2θ )= 1.0 could be disfavoured with the exposure of the current dataset if the true mixing angle was non-maximal, was also investigated, with an improved neutrino energy reconstruction for very low energy events. The best fit oscillation parameters, obtained by the fitting software and incorporating resolution information were: | Δm2| = 2.32+0.12 -0.08×10-3 eV2 and sin2 (2θ ) > 0.90(90% C.L.). The analysis provides the current world best measurement of the atmospheric neutrino mass

  12. Realistic PET Monte Carlo Simulation With Pixelated Block Detectors, Light Sharing, Random Coincidences and Dead-Time Modeling

    Science.gov (United States)

    Guérin, Bastein; Fakhri, Georges El

    2008-01-01

    We have developed and validated a realistic simulation of random coincidences, pixelated block detectors, light sharing among crystal elements and dead-time in 2D and 3D positron emission tomography (PET) imaging based on the SimSET Monte Carlo simulation software. Our simulation was validated by comparison to a Monte Carlo transport code widely used for PET modeling, GATE, and to measurements made on a PET scanner. Methods We have modified the SimSET software to allow independent tracking of single photons in the object and septa while taking advantage of existing voxel based attenuation and activity distributions and validated importance sampling techniques implemented in SimSET. For each single photon interacting in the detector, the energy-weighted average of interaction points was computed, a blurring model applied to account for light sharing and the associated crystal identified. Detector dead-time was modeled in every block as a function of the local single rate using a variance reduction technique. Electronic dead-time was modeled for the whole scanner as a function of the prompt coincidences rate. Energy spectra predicted by our simulation were compared to GATE. NEMA NU-2 2001 performance tests were simulated with the new simulation as well as with SimSET and compared to measurements made on a Discovery ST (DST) camera. Results Errors in simulated spatial resolution (full width at half maximum, FWHM) were 5.5% (6.1%) in 2D (3D) with the new simulation, compared with 42.5% (38.2%) with SimSET. Simulated (measured) scatter fractions were 17.8% (21.3%) in 2D and 45.8% (45.2%) in 3D. Simulated and measured sensitivities agreed within 2.3 % in 2D and 3D for all planes and simulated and acquired count rate curves (including NEC) were within 12.7% in 2D in the [0: 80 kBq/cc] range and in 3D in the [0: 35 kBq/cc] range. The new simulation yielded significantly more realistic singles’ and coincidences’ spectra, spatial resolution, global sensitivity and lesion

  13. Monte Carlo simulation to positron emitter standardized by means of 4pibeta-gamma coincidence system--application to 22Na.

    Science.gov (United States)

    Dias, Mauro S; Tongu, Margareth L O; Takeda, Mauro N; Koskinas, Marina F

    2010-01-01

    The present work describes the methodology for predicting the behavior of extrapolation curves obtained in radionuclide standardization by 4pibeta-gamma coincidence measurements, applied to (22)Na, developed at the Laboratório de Metrologia Nuclear of IPEN-CNEN/SP (LMN-Nuclear Metrology Laboratory). The LMN system consists of a proportional counter (PC) in 4pi geometry coupled to a single or a pair of NaI(Tl) scintillation crystals. Two standardization techniques were used: the Sum-Peak and the Nuclear-Peak methods. The theoretical response functions of each detector have been calculated using the MCNPX Monte Carlo code. The code ESQUEMA, developed at LMN, has been used for calculating the extrapolation curve in the 4pibeta-gamma coincidence experiment. Modifications were performed in order to include response tables for positrons and coincidences with annihilation photons. From the calibration results it was possible to extract both the activity value and the positron emission probability per decay. The latter was compared with results from the literature.

  14. Measuring and Modeling Xenon Uptake in Plastic Beta-Cells

    Science.gov (United States)

    Suarez, R.; Hayes, J. C.; Harper, W. W.; Humble, P.; Ripplinger, M. D.; Stephenson, D. E.; Williams, R. M.

    2013-12-01

    The precision of the stable xenon volume measurement in atmospheric monitoring radio-xenon systems is a critical parameter used to determine the activity concentration of a radio-xenon sample. Typically these types of systems use a plastic scintillating beta-cell as part of a beta-gamma detection scheme to measure the radioactivity present in the gas sample. Challenges arise when performing the stable xenon calculation during or after radioactive counting of the sample due to xenon uptake into the plastic beta-cells. Plastic beta cells can adsorb as much as 5% of the sample during counting. If quantification is performed after counting, the uptake of xenon into the plastic results in an underestimation of the xenon volume measurement. This behavior also causes what is typically known as 'memory effect' in the cell. Experiments were conducted using a small volume low pressure range thermal conductivity sensor to quantify the amount of xenon uptake into the cell over a given period of time. Understanding the xenon uptake in the cell provides a better estimate of the stable volume which improves the overall measurement capability of the system. The results from these experiments along with modeling will be presented.

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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)

  20. Application of the coincidence counting technique to DD neutron spectrometry data at the NIF, OMEGA, and Z

    Science.gov (United States)

    Lahmann, B.; Milanese, L. M.; Han, W.; Gatu Johnson, M.; Séguin, F. H.; Frenje, J. A.; Petrasso, R. D.; Hahn, K. D.; Jones, B.

    2016-11-01

    A compact neutron spectrometer, based on a CH foil for the production of recoil protons and CR-39 detection, is being developed for the measurements of the DD-neutron spectrum at the NIF, OMEGA, and Z facilities. As a CR-39 detector will be used in the spectrometer, the principal sources of background are neutron-induced tracks and intrinsic tracks (defects in the CR-39). To reject the background to the required level for measurements of the down-scattered and primary DD-neutron components in the spectrum, the Coincidence Counting Technique (CCT) must be applied to the data. Using a piece of CR-39 exposed to 2.5-MeV protons at the MIT HEDP accelerator facility and DD-neutrons at Z, a significant improvement of a DD-neutron signal-to-background level has been demonstrated for the first time using the CCT. These results are in excellent agreement with previous work applied to DT neutrons.

  1. Sub-100 ps coincidence time resolution for positron emission tomography with LSO:Ce codoped with Ca

    CERN Document Server

    Nemallapudi, Mythra Varun; Lecoq, Paul; Auffray, Etiennette; Ferri, Alessandro; Gola, Alberto; Piemonte, Claudio

    2015-01-01

    The coincidence time resolution (CTR) becomes a key parameter of 511keV gamma detection in time of flight positron emission tomography (TOF-PET). This is because additional information obtained through timing leads to a better noise suppression and therefore a better signal to noise ratio in the reconstructed image. In this paper we present the results of CTR measurements on two different SiPM technologies from FBK coupled to LSO:Ce codoped 0.4%Ca crystals. We compare the measurements performed at two separate test setups, i.e. at CERN and at FBK, showing that the obtained results agree within a few percent. We achieve a best CTR value of 85  ±  4 ps FWHM for 2  ×  2  ×  3 mm3 LSO:Ce codoped 0.4%Ca crystals, thus breaking the 100 ps barrier with scintillators similar to LSO:Ce or LYSO:Ce. We also demonstrate that a CTR of 140  ±  5 ps can be achieved for longer 2  ×  2  ×  20 mm3 crystals, which can readily be implemented in the current generation PET syst...

  2. Comparison of Coincident Terrestrial and Airborne Lidar Datasets with Respect to Detection of Ground Metrics and Topographic Change

    Science.gov (United States)

    Kayen, R. E.; Stewart, J. P.; Lembo, A. J.; Hu, J.; Davis, C. A.; Hogue, T.; Collins, B. D.; Minasian, D.; Louis-Kayen, N. M.; O'Rourke, T. D.

    2008-12-01

    The Multidisciplinary Center for Earthquake Engineering Research and National Science Foundation, in collaboration with the City of Los Angeles Department of Water and Power (LADWP), coordinated a controlled study of the use of pulse-based terrestrial lidar and phase-based airborne lidar systems to detect topographic changes and ground deformations in areas of buried pipelines subject to earthquakes and storm-induced landslides. Terrestrial and airborne lidar scans were performed at three LADWP sites in the Los Angeles region and their accuracy was evaluated using coincident high-precision total station survey measurements as a control. Horizontal accuracy was evaluated through the measurement of latitude Northing and longitude Easting (standardized to WGS84) residuals for distances separating well defined objects in the lidar scans, such as buildings and tanks. The bias and dispersion of lidar elevation measurements (standardized to NGVD88) was assessed at a flat un-vegetated site near the Los Angeles Reservoir before and after carefully measured trenching, and at a heavily vegetated and steeply sloping site at Power Plant 2 in San Francisquito Canyon. At the trench site, airborne lidar showed minimal bias and standard deviation (6-20 cm), whereas terrestrial lidar was nearly unbiased with very low dispersion (4-6 cm). Pre- and post-trench bias-adjusted normalized residuals are essentially randomly scattered, but elevation change was affected by relative bias within epochs. At the PP2 site, airborne lidar showed minimal elevation bias and a standard deviation of approximately 50 cm, whereas terrestrial lidar demonstrated large bias and dispersion (on order of meters) due the inability of side-looking ground-based lidar to penetrate heavy vegetation. With careful calibration, both terrestrial and airborne lidar are capable of measuring centimeter-to decimeter level ground displacements for large features in areas of minimal vegetation, whereas their application is

  3. 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.

  4. 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)

  5. 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...

  6. 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.

  7. 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

  8. 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 £ ...

  9. 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.

  10. 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

  11. 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.

  12. 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}.

  13. 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)

  14. 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

  15. 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 (...

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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 ...

  1. 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.)

  2. 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)

  3. 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

  4. Continuous monitoring α-activity on aerosol filters by the pseudo-coincidence-technique. Explicitly taking into account the short lived Po-218 activity

    International Nuclear Information System (INIS)

    Pseudo-coincidence-technique is applied to continuous monitoring of α-activity on aerosolfilters by proportional counters. Filter activity can markedly increase or decrease by changing air conditions especially by the amount of short lived Po-218 activity. Conditions of constant proportions of activity concentrations for the short lived species for operating this technique are seldom fulfilled. The dynamic behavior of artificial (long lived) and natural (short lived) activity is mathematically modelled and the measured moving count rates are analyzed under this model by a multivariate regression analysis for activity concentrations of artificial resp. short lived activity. Results are compared to standard recommendations of DIN ISO 11929.

  5. 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.

  6. 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

  7. 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)

  8. Poster — Thur Eve — 07: Simultaneous reconstruction of both true and scattered coincidences using a Generalized Scatter reconstruction algorithm in PET

    International Nuclear Information System (INIS)

    Introduction: Scattered coincidences in PET are generally taken as noise, which reduces image contrast and compromises quantification. We have developed a method, with promising results, to reconstruct activity distribution from scattered PET events instead of simply correcting for them. The implementation of this method on clinical PET scanners is however limited by the currently available detector energy resolution. With low energy resolution we lose the ability to distinguish scattered coincidences from true events based on the measured photon energy. In addition the two circular arcs used to confine the source position for a scattered event cannot be accurately defined. Method: This paper presents a modification to this approach which accounts for limited energy resolution. A measured event is split into a true and a scattered component each with different probabilities based on the position of the pair of photon energies in the energy spectrum. For the scattered component, we model the photon energy with a Gaussian distribution and the upper and lower energy limits can be estimated and used to define inner and outer circular arcs to confine the source position. The true and scattered components for each measured event were reconstructed using our Generalized Scatter reconstruction algorithm. Results and Conclusion: The results show that the contrast and noise properties were improved by 6–9% and 2–4% respectively. This demonstrates that the performance of the algorithm is less sensitive to the energy resolution and that incorporating scattered photons into reconstruction brings more benefits than simply rejecting them

  9. {sup 18F}-FDG PET imaging with dual head gamma camera and co-incidence detection

    Energy Technology Data Exchange (ETDEWEB)

    Quach, T.; Camden, B.M.; Chu, J.M.G. [Liverpool Health Services, Liverpool, NSW (Australia). Department of Nuclear Medicine and Clinical Ultrasound

    1998-06-01

    Full text: {sup 18F}-Fluorodeoxyglucose (FDG) positron tomography is based on the detection of two 511 keV photons which are produced 180 deg apart as a result of an annihilation of a positron and an electron. Apart from the dedicated PET scanner, dual head gamma camera designed for Co-incidence Detection (CD) can now perform `{sup 18}F-FDG PET studies. CD imaging involves using a dual head gamma camera to detect those photons which are 180 deg apart and fall within a timing window of 15 nsec. No collimators are required as a timing gate of 15 nsec is used. {sup 18}F-FDG studies are performed using an ADAC Solus Molecular Co-incidence Detection (MCD) dual head gamma camera. The patients are fasted from midnight but well hydrated before the scan. Prior to injection, the blood sugar levels (BSL) are measured. For optimal {sup 18}F-FDG uptake, the BSL should be less than 8.9 mmol/L. A dose of 200MBq of {sup 18}F-FDG is intravenously injected via a cannula. Scanning commences at 1 hour post injection. To perform a wholebody tomography of the torso, the patient must void before scanning to reduce bladder activity. Excessive bladder activity leads to significant image degradation, therefore the wholebody tomography is started from the pelvis. Depending on the patient torso length, either 2 or 3 tomographies are collected with a 50% overlap. Each tomography is collected for 40 seconds per step for 32 steps. To avoid attenuation from the upper limbs, the patient is positioned supine with the arms above the head. If a patient cannot tolerate this position, scanning with the arms by the side may be necessary since the scanning time may take up to 50 minutes. If the area of interest is the neck, scanning with the patient`s arms down by their sides is preferred, although attenuation will occur. To scan the brain, a circular tomography is performed using 32 steps at 80 seconds per step. For processing purposes, the Singles count rate for each detector must be between 800K and

  10. The Contribution of and Uncertainty Associated with Self-Multiplication when Assaying Plutonium in Waste by Passive Neutron Coincidence Counting

    International Nuclear Information System (INIS)

    When Pu is present in waste items as lumps, the Reals neutron coincidence signal may be bolstered by virtue of self induced fission events. This gives rise to a positive bias to the assay result and leads to a one sided contribution to the total measurement uncertainty. In the general it is not feasible to determine to magnitude of this effect experimentally and allowance for it must therefore be estimated using separate ad hoc rules. In this paper we to develop a simple model for the self-multiplication enhancement in small lumps allowing the importance of the effect in waste assay to be quantified. In addition, an approach is suggested for how to propagate an uncertainty contribution in to the final result. In conclusion: By introducing a generic scheme we have taken the first pragmatic steps to accounting for multiplication effects in the TMU in the determination of Pu-240 eff-mass by PNCC in waste. We have used a simple physical model to derive the underlying relationships needed. A first order expression suitable for small, dense lumps was set out, primarily for instructive reasons, but this is not a restriction of the method. The method is readily scaleable to material of different isotopic composition, density and a. Numerical parameters suitable for practical applications have been established and we feel the approach is fit for the intended purpose reflecting operational experiences and the general state of knowledge of waste items. (authors)

  11. The Design, Implementation, and Performance of the Astro-H SXS Calorimeter Array and Anti-Coincidence Detector

    Science.gov (United States)

    Kilbourne, Caroline A.; Adams, Joseph S.; Brekosky, Regis P.; Chiao, Meng P.; Chervenak, James A.; Eckart, Megan E.; Figueroa-Feliciano, Enectali; Galeazzi, Masimilliano; Grein, Christoph; Jhabvala, Christine A.; Kelley, Richard L.; Leutenegger, Maurice A.; McCammon, Dan; Porter, F. Scott; Szymkowiak, Andrew E.; Watanabe, Tomomi; Zhao, Jun

    2016-01-01

    The calorimeter array of the JAXA Astro-H (renamed Hitomi) Soft X-ray Spectrometer (SXS) was designed to provide unprecedented spectral resolution of spatially extended cosmic x-ray sources and of all cosmic x-ray sources in the Fe-K band around 6 keV, enabling essential plasma diagnostics. The SXS has a square array of 36 microcalorimeters at the focal plane. These calorimeters consist of ion-implanted silicon thermistors and HgTe thermalizing x-ray absorbers. These devices have demonstrated a resolution of better than 4.5 eV at 6 keV when operated at a heat-sink temperature of 50 mK. We will discuss the basic physical parameters of this array, including the array layout, thermal conductance of the link to the heat sink, resistance function, absorber details, and means of attaching the absorber to the thermistor-bearing element. We will also present the thermal characterization of the whole array, including thermal conductance and crosstalk measurements and the results of pulsing the frame temperature via alpha particles, heat pulses, and the environmental background. A silicon ionization detector is located behind the calorimeter array and serves to reject events due to cosmic rays. We will briefly describe this anti-coincidence detector and its performance.

  12. Grain boundary character distributions of coincidence site lattice boundaries in WC-Co composites with different WC grain sizes

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Xiaokun, E-mail: yuanxiaokun@bjut.edu.cn

    2013-12-05

    Highlights: •GBCDs of two kinds of CSL boundaries in cemented carbides are examined. •Carbide mean grain size is determinant in controlling the populations of CSL boundaries. •Rapid decrease of sigma2 boundaries occurs at higher speed than the coarsening of carbide grains. -- Abstract: The grain boundary character distributions of sigma2 and sigma13 boundaries were investigated in cemented carbide samples with different carbide grain sizes. Samples were prepared with average carbide grain sizes of about 0.5 μm, 1 μm and 2 μm, respectively. The electron backscattered diffraction measurements show that with the increase of the carbide grain size, populations of both sigma2 and sigma13 boundaries decrease; in the meantime, the sigma2 twist and sigma13 twist boundaries keep as the most common boundary types. The results suggest that the carbide grain size could be determinant in controlling the populations of coincidence site lattice boundaries in WC-Co composites.

  13. Grain boundary character distributions of coincidence site lattice boundaries in WC-Co composites with different WC grain sizes

    International Nuclear Information System (INIS)

    Highlights: •GBCDs of two kinds of CSL boundaries in cemented carbides are examined. •Carbide mean grain size is determinant in controlling the populations of CSL boundaries. •Rapid decrease of sigma2 boundaries occurs at higher speed than the coarsening of carbide grains. -- Abstract: The grain boundary character distributions of sigma2 and sigma13 boundaries were investigated in cemented carbide samples with different carbide grain sizes. Samples were prepared with average carbide grain sizes of about 0.5 μm, 1 μm and 2 μm, respectively. The electron backscattered diffraction measurements show that with the increase of the carbide grain size, populations of both sigma2 and sigma13 boundaries decrease; in the meantime, the sigma2 twist and sigma13 twist boundaries keep as the most common boundary types. The results suggest that the carbide grain size could be determinant in controlling the populations of coincidence site lattice boundaries in WC-Co composites

  14. Characterization of a Prototype TES-Based Anti-coincidence Detector for Use with Future X-ray Calorimeter Arrays

    Science.gov (United States)

    Busch, S. E.; Yoon, W. S.; Adams, J. S.; Bailey, C. N.; Bandler, S. R.; Chervenak, J. A.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Lee, S.-J.; Porst, J.-P.; Porter, F. S.; Sadleir, J. E.; Smith, S. J.; Sultana, M.

    2016-07-01

    For future X-ray observatories utilizing transition-edge sensor (TES) microcalorimeters, an anti-coincidence detector (anti-co) is required to discriminate X-ray (˜ 0.1-10 keV) signals from non-X-ray background events, such as ionizing particles. We have developed a prototype anti-co that utilizes TESs, which will be compatible with the TES focal-plane arrays planned for future X-ray observatories. This anti-co is based upon the cryogenic dark matter search II detector design. It is a silicon wafer covered with superconducting collection fins and TES microcalorimeters. Minimum ionizing particles deposit energy while passing through the silicon. The athermal phonons produced by these events are absorbed in the superconducting fins, breaking Cooper pairs. The resulting quasiparticles diffuse along the superconducting fin, producing a signal when they reach the TES. By determining a correlation between detections in the anti-co and the X-ray detector one can identify and flag these background events. We have fabricated and tested a single-channel prototype anti-co device on a 1.5 × 1.9 cm^2 chip. We have measured the signals in this device from photons of several energies between 1.5 and 60 keV, as well as laboratory background events, demonstrating a threshold ˜ 100 times lower than is needed to detect minimum ionizing particles.

  15. Coincidence Anticipation Timing Performance during an Acute Bout of Brisk Walking in Older Adults: Effect of Stimulus Speed.

    Science.gov (United States)

    Duncan, Michael J; Stanley, Michelle; Smith, Mike; Price, Michael J; Wright, Sheila Leddington

    2015-01-01

    This study examined coincidence anticipation timing (CAT) performance at slow and fast stimulus speeds before, during, and after an acute bout of walking in adults aged 60-76 years. Results from a series of repeated measures ANOVAs indicated significant rest versus exercise × stimulus speed × time interactions for absolute and variable errors (both P = 0.0001) whereby absolute and variable error scores, when stimulus speed was slow, improved as the duration of exercise increased. When stimulus speed was fast there were significantly greater absolute and variable errors at 18 minutes of the walking bout. There was also greater error at 18 minutes during walking compared to rest. These results suggest that, in a task involving walking and CAT, stimulus speeds plays an important role; specifically walking (exercise) enhances CAT performance at slow stimulus speeds but reduces CAT performance at fast stimulus speeds. The implications are that in everyday situations, where events require dual-task responses to be made at different speeds, for example, walking on the pavement whilst avoiding a crowd, compared to crossing a busy road, an understanding of how different stimulus speeds influence dual-task performance is extremely important, particularly in the older adult population.

  16. Coincidence Anticipation Timing Performance during an Acute Bout of Brisk Walking in Older Adults: Effect of Stimulus Speed

    Directory of Open Access Journals (Sweden)

    Michael J. Duncan

    2015-01-01

    Full Text Available This study examined coincidence anticipation timing (CAT performance at slow and fast stimulus speeds before, during, and after an acute bout of walking in adults aged 60–76 years. Results from a series of repeated measures ANOVAs indicated significant rest versus exercise × stimulus speed × time interactions for absolute and variable errors (both P=0.0001 whereby absolute and variable error scores, when stimulus speed was slow, improved as the duration of exercise increased. When stimulus speed was fast there were significantly greater absolute and variable errors at 18 minutes of the walking bout. There was also greater error at 18 minutes during walking compared to rest. These results suggest that, in a task involving walking and CAT, stimulus speeds plays an important role; specifically walking (exercise enhances CAT performance at slow stimulus speeds but reduces CAT performance at fast stimulus speeds. The implications are that in everyday situations, where events require dual-task responses to be made at different speeds, for example, walking on the pavement whilst avoiding a crowd, compared to crossing a busy road, an understanding of how different stimulus speeds influence dual-task performance is extremely important, particularly in the older adult population.

  17. 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)

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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)

  6. 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.

  7. 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)

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  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. F-18-FDG positron imaging in oncological patients: gamma camera coincidence detection versus dedicated PET

    Energy Technology Data Exchange (ETDEWEB)

    Zimny, M.; Kaiser, H.J.; Cremerius, U.; Sabri, O.; Schreckenberger, M.; Reinartz, P.; Buell, U. [Technische Hochschule Aachen (Germany). Klinik fuer Nuklearmedizin

    1999-08-01

    Aim of the present study was to investigate the feasibility of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) imaging in oncological patients with a dual head gamma camera modified for coincidence detection (MCD). Methods: Phantom studies were done to determine lesion detection at various lesion-to-background ratios, system sensitivity and spatial resolution. Thirty-two patients with suspected or known malignant disease were first studied with a dedicated full-ring PET system (DPET) applying measured attenuation correction and subsequently with an MCD system without attenuation correction. MCD images were first interpreted without knowledge of the DPET findings. In a second reading, MCD and DPET were evaluated simultaneously. Results: The phantom studies revealed a comparable spatial resolution for DPET and MCD (5.9 x 6.3 x 4.2 mm vs. 5.9 x 6.5 x 6.0 mm). System sensitivity of MCD was less compared to DPET (91 cps/Bq/ml/cm{sub FOV} vs. 231 cps/Bq/ml/cm{sub FOV}). At a lesion-to-background ratio of 4:1, DPET depicted a minimal phantom lesion of 1.0 cm in diameter, MCD a minimal lesion of 1.6 cm. With DPET, a total of 91 lesions in 27 patients were classified as malignant. MCD without knowledge of DPET results revealed increased FDG uptake in all patients with positive DPET findings. MCD detected 72 out of 91 DPET lesions (79.1%). With knowledge of the DPET findings, 11 additional lesions were detected (+12%). MCD missed lesions in six patients with relevance for staging in two patients. All lesions with a diameter above 18 mm were detected. Conclusion: MCD FDG imaging yielded results comparable to dedicated PET in most patients. However, a considerable number of small lesions clearly detectable with DPET were not detected by MCD alone. Therefore, MCD cannot yet replace dedicated PET in all oncological FDG studies. Further technical refinement of this new method is needed to improve imaging quality (e.g. attenuation correction). (orig.) [Deutsch] Ziel dieser Studie

  18. The coincidence counting technique for orders of magnitude background reduction in data obtained with the magnetic recoil spectrometer at OMEGA and the NIF.

    Science.gov (United States)

    Casey, D T; Frenje, J A; Séguin, F H; Li, C K; Rosenberg, M J; Rinderknecht, H; Manuel, M J-E; Gatu Johnson, M; Schaeffer, J C; Frankel, R; Sinenian, N; Childs, R A; Petrasso, R D; Glebov, V Yu; Sangster, T C; Burke, M; Roberts, S

    2011-07-01

    A magnetic recoil spectrometer (MRS) has been built and successfully used at OMEGA for measurements of down-scattered neutrons (DS-n), from which an areal density in both warm-capsule and cryogenic-DT implosions have been inferred. Another MRS is currently being commissioned on the National Ignition Facility (NIF) for diagnosing low-yield tritium-hydrogen-deuterium implosions and high-yield DT implosions. As CR-39 detectors are used in the MRS, the principal sources of background are neutron-induced tracks and intrinsic tracks (defects in the CR-39). The coincidence counting technique was developed to reduce these types of background tracks to the required level for the DS-n measurements at OMEGA and the NIF. Using this technique, it has been demonstrated that the number of background tracks is reduced by a couple of orders of magnitude, which exceeds the requirement for the DS-n measurements at both facilities.

  19. VUV photoionization of acetamide studied by electron/ion coincidence spectroscopy in the 8-24 eV photon energy range

    KAUST Repository

    Schwell, Martin

    2012-01-01

    A VUV photoionization study of acetamide was carried out over the 8-24 eV photon energy range using synchrotron radiation and photoelectron/photoion coincidence (PEPICO) spectroscopy. Threshold photoelectron photoion coincidence (TPEPICO) measurements were also made. Photoion yield curves and branching ratios were measured for the parent ion and six fragment ions. The adiabatic ionization energy of acetamide was determined as I.E. (1 2A′) = (9.71 ± 0.02) eV, in agreement with an earlier reported photoionization mass spectrometry (PIMS) value. The adiabatic energy of the first excited state of the ion, 1 2A″, was determined to be ≈10.1 eV. Assignments of the fragment ions and the pathways of their formation by dissociative photoionization were made. The neutral species lost in the principal dissociative photoionization processes are CH 3, NH 2, NH 3, CO, HCCO and NH 2CO. Heats of formation are derived for all ions detected and are compared with literature values. Some astrophysical implications of these results are discussed. © 2011 Elsevier B.V. All rights reserved.

  20. Analysis of minor elements in steel by coincidence method in deuteron-induced prompt gamma-ray emission (D-PIGE)

    International Nuclear Information System (INIS)

    Among the factors affecting the sensitivity of PIGE method (particle-induced prompt gamma-ray emission) frequently discussed in the literature, the background in the γ-ray spectrum holds a prominent place. In this work the limits of detection of minor elements in a standard steel sample (Euronorm rm No. 085/1) irradiated with 5 MeV deuterons have been determined by the regular d-PIGE method and with the selection of the (d,n) reaction channel by measuring γ--n coincidences following the reaction steel + deuterons. This approach has resulted in a significant improvement of the sensitivity of the analysis, reducing the background in prompt gamma ray spectrum by eliminating the γ--rays observed in the singular spectrum which arises from the reaction channels (d, d'), (d, γ), (d, p), (d, 3 He), (d, α) and (d, t). From the singular spectrum we could establish the presence of the elements S, Pb, Mo, Co, V, P, O, Si, Zn, Mn, Cu, Sb, C, Al, N, As, Ti and Fe. The γ--n coincidence spectrum, obtained as a result of the selection of the γ- transitions via the reaction channel (d, n), is substantially different from the singular γ--spectrum, exhibiting γ- lines of rather high intensity to be used in the analyses on a reduced background. The coincidence spectrum shows lines from S, Mo, Co, Zn, Si, Mn, V, Sb, Ti, As, Ni, Cr, P, O, Al, Cu and Fe. We also made a comparative study with the published results using 5.5 MeV protons as projectiles. While for a given energy of the protons not all the elements of interest lead to a (p, n) reaction (C, O, P, S, Si etc.), most of the (d, n) reactions are exoergic. On the other side, the identification of the elements is more difficult in the case of deuterons. (authors)

  1. Coincidence measurements on detectors for microPET II: A 1 mm3 resolution PET scanner for small animal imaging

    CERN Document Server

    Chatziioannou, A; Shao, Y; Doshi, N K; Silverman, B; Meadors, K; Cherry, SR

    2000-01-01

    We are currently developing a small animal PET scanner with a design goal of 1 mm3 image resolution. We have built three pairs of detectors and tested performance in terms of crystal identification, spatial, energy and timing resolution. The detectors consisted of 12 multiplied by 12 arrays of 1 multiplied by 1 multiplied by 10mm LSO crystals (1.15 mm pitch) coupled to Hamamatsu H7546 64 channel PMTs via 5cm long coherent glass fiber bundles. Optical fiber connection is necessary to allow high packing fraction in a ring geometry scanner. Fiber bundles with and without extramural absorber (EMA) were tested. The results demonstrated an intrinsic spatial resolution of 1.12 mm (direct coupled LSO array), 1.23 mm (bundle without EMA) and 1.27 mm (bundle with EMA) using a similar to 500 micron diameter Na-22 source. Using a 330 micron line source filled with F-18, intrinsic resolution for the EMA bundle improved to 1.05 mm. The respective timing and energy resolution values were 1.96 ns, 21% (direct coupled), 2.20 ...

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Excited state dynamics in SO2. I. Bound state relaxation studied by time-resolved photoelectron-photoion coincidence spectroscopy.

    Science.gov (United States)

    Wilkinson, Iain; Boguslavskiy, Andrey E; Mikosch, Jochen; Bertrand, Julien B; Wörner, Hans Jakob; Villeneuve, David M; Spanner, Michael; Patchkovskii, Serguei; Stolow, Albert

    2014-05-28

    The excited state dynamics of isolated sulfur dioxide molecules have been investigated using the time-resolved photoelectron spectroscopy and time-resolved photoelectron-photoion coincidence techniques. Excited state wavepackets were prepared in the spectroscopically complex, electronically mixed (B̃)(1)B1/(Ã)(1)A2, Clements manifold following broadband excitation at a range of photon energies between 4.03 eV and 4.28 eV (308 nm and 290 nm, respectively). The resulting wavepacket dynamics were monitored using a multiphoton ionisation probe. The extensive literature associated with the Clements bands has been summarised and a detailed time domain description of the ultrafast relaxation pathways occurring from the optically bright (B̃)(1)B1 diabatic state is presented. Signatures of the oscillatory motion on the (B̃)(1)B1/(Ã)(1)A2 lower adiabatic surface responsible for the Clements band structure were observed. The recorded spectra also indicate that a component of the excited state wavepacket undergoes intersystem crossing from the Clements manifold to the underlying triplet states on a sub-picosecond time scale. Photoelectron signal growth time constants have been predominantly associated with intersystem crossing to the (c̃)(3)B2 state and were measured to vary between 750 and 150 fs over the implemented pump photon energy range. Additionally, pump beam intensity studies were performed. These experiments highlighted parallel relaxation processes that occurred at the one- and two-pump-photon levels of excitation on similar time scales, obscuring the Clements band dynamics when high pump beam intensities were implemented. Hence, the Clements band dynamics may be difficult to disentangle from higher order processes when ultrashort laser pulses and less-differential probe techniques are implemented.

  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. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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).

  14. 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

  15. 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.

  16. 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.)

  17. 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.

  18. 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...

  19. 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.

  20. 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.