Sample records for shown anda detector

  1. Implementation of the P barANDA Planar-GEM tracking detector in Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Divani Veis, Nazila; Ehret, Andre; Firoozabadi, Mohammad M.; Karabowicz, Radoslaw; Maas, Frank; Saito, Nami; Saito, Takehiko R.; Voss, Bernd; PANDA Gem-Tracker Subgroup

    2018-02-01

    The P barANDA experiment at FAIR will be performed to investigate different aspects of hadron physics using anti-proton beams interacting with a fixed nuclear target. The experimental setup consists of a complex series of detector components covering a large solid angle. A detector with a gaseous active media equipped with gas electron multiplier (GEM) technique will be employed to measure tracks of charged particles at forward direction in order to achieve a high momentum resolution. In this work, a full setup of the GEM tracking detector has been implemented in the P barANDA Monte Carlo simulation package (PandaRoot) based on the current technical and conceptual design, and the expected performance of the P barANDA GEM-tracking detector has been investigated. Furthermore, material-budget studies in terms of the radiation length of the P barANDA GEM-tracking detector have been made in order to investigate the effect of the detector materials and its associated structures to particle measurements.

  2. Performance studies of the P barANDA planar GEM-tracking detector in physics simulations

    NASA Astrophysics Data System (ADS)

    Divani Veis, Nazila; Firoozabadi, Mohammad M.; Karabowicz, Radoslaw; Maas, Frank; Saito, Takehiko R.; Voss, Bernd; ̅PANDA Gem-Tracker Subgroup

    2018-03-01

    The P barANDA experiment will be installed at the future facility for antiproton and ion research (FAIR) in Darmstadt, Germany, to study events from the annihilation of protons and antiprotons. The P barANDA detectors can cover a wide physics program about baryon spectroscopy and nucleon structure as well as the study of hadrons and hypernuclear physics including the study of excited hyperon states. One very specific feature of most hyperon ground states is the long decay length of several centimeters in the forward direction. The central tracking detectors of the P barANDA setup are not sufficiently optimized for these long decay lengths. Therefore, using a set of the planar GEM-tracking detectors in the forward region of interest can improve the results in the hyperon physics-benchmark channel. The current conceptual designed P barANDA GEM-tracking stations contribute the measurement of the particles emitted in the polar angles between about 2 to 22 degrees. For this designed detector performance and acceptance, studies have been performed using one of the important hyperonic decay channel p bar p → Λ bar Λ → p bar pπ+π- in physics simulations. The simulations were carried out using the PandaRoot software packages based on the FairRoot framework.

  3. Interface of the general fitting tool GENFIT2 in PandaRoot

    NASA Astrophysics Data System (ADS)

    Prencipe, Elisabetta; Spataro, Stefano; Stockmanns, Tobias; PANDA Collaboration

    2017-10-01

    \\bar{{{P}}}ANDA is a planned experiment at FAIR (Darmstadt) with a cooled antiproton beam in a range [1.5; 15] GeV/c, allowing a wide physics program in nuclear and particle physics. It is the only experiment worldwide, which combines a solenoid field (B=2T) and a dipole field (B=2Tm) in a spectrometer with a fixed target topology, in that energy regime. The tracking system of \\bar{{{P}}}ANDA involves the presence of a high performance silicon vertex detector, a GEM detector, a straw-tubes central tracker, a forward tracking system, and a luminosity monitor. The offline tracking algorithm is developed within the PandaRoot framework, which is a part of the FairRoot project. The tool here presented is based on algorithms containing the Kalman Filter equations and a deterministic annealing filter. This general fitting tool (GENFIT2) offers to users also a Runge-Kutta track representation, and interfaces with Millepede II (useful for alignment) and RAVE (vertex finder). It is independent on the detector geometry and the magnetic field map, and written in C++ object-oriented modular code. Several fitting algorithms are available with GENFIT2, with user-adjustable parameters; therefore the tool is of friendly usage. A check on the fit convergence is done by GENFIT2 as well. The Kalman-Filter-based algorithms have a wide range of applications; among those in particle physics they can perform extrapolations of track parameters and covariance matrices. The adoptions of the PandaRoot framework to connect to Genfit2 are described, and the impact of GENFIT2 on the physics simulations of \\bar{{{P}}}ANDA are shown: significant improvement is reported for those channels where a good low momentum tracking is required (pT < 400 MeV/c).

  4. Technical design report for the overline{P}ANDA (Anti Proton Annihilations at Darmstadt) Straw Tube Tracker. Strong interaction studies with antiprotons

    NASA Astrophysics Data System (ADS)

    Erni, W.; Keshelashvili, I.; Krusche, B.; Steinacher, M.; Heng, Y.; Liu, Z.; Liu, H.; Shen, X.; Wang, Q.; Xu, H.; Aab, A.; Albrecht, M.; Becker, J.; Csapó, A.; Feldbauer, F.; Fink, M.; Friedel, P.; Heinsius, F. H.; Held, T.; Klask, L.; Koch, H.; Kopf, B.; Leiber, S.; Leyhe, M.; Motzko, C.; Pelizäus, M.; Pychy, J.; Roth, B.; Schröder, T.; Schulze, J.; Sowa, C.; Steinke, M.; Trifterer, T.; Wiedner, U.; Zhong, J.; Beck, R.; Bianco, S.; Brinkmann, K. T.; Hammann, C.; Hinterberger, F.; Kaiser, D.; Kliemt, R.; Kube, M.; Pitka, A.; Quagli, T.; Schmidt, C.; Schmitz, R.; Schnell, R.; Thoma, U.; Vlasov, P.; Walther, D.; Wendel, C.; Würschig, T.; Zaunick, H. G.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Pantelica, D.; Pietreanu, D.; Serbina, L.; Tarta, P. D.; Kaplan, D.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Czech, B.; Kistryn, M.; Kliczewski, S.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Siudak, R.; Szczurek, A.; Jowzaee, S.; Kajetanowicz, M.; Kamys, B.; Kistryn, S.; Korcyl, G.; Korcyl, K.; Krzemien, W.; Magiera, A.; Moskal, P.; Palka, M.; Rudy, Z.; Salabura, P.; Smyrski, J.; Wrońska, A.; Augustin, I.; Lehmann, I.; Nimorus, D.; Schepers, G.; Al-Turany, M.; Arora, R.; Deppe, H.; Flemming, H.; Gerhardt, A.; Götzen, K.; Jordi, A. F.; Kalicy, G.; Karabowicz, R.; Lehmann, D.; Lewandowski, B.; Lühning, J.; Maas, F.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V. M.; Alexeev, G.; Arefiev, A.; Astakhov, V. I.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Yu. I.; Dodokhov, V. Kh.; Efremov, A. A.; Fedunov, A. G.; Festchenko, A. A.; Galoyan, A. S.; Grigoryan, S.; Karmokov, A.; Koshurnikov, E. K.; Lobanov, V. I.; Lobanov, Yu. Yu.; Makarov, A. F.; Malinina, L. V.; Malyshev, V. L.; Mustafaev, G. A.; Olshevskiy, A.; Pasyuk, M. A.; Perevalova, E. A.; Piskun, A. A.; Pocheptsov, T. A.; Pontecorvo, G.; Rodionov, V. K.; Rogov, Yu. N.; Salmin, R. A.; Samartsev, A. G.; Sapozhnikov, M. G.; Shabratova, G. S.; Skachkova, A. N.; Skachkov, N. B.; Strokovsky, E. A.; Suleimanov, M. K.; Teshev, R. Sh.; Tokmenin, V. V.; Uzhinsky, V. V.; Vodopyanov, A. S.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Woods, P.; Britting, A.; Eyrich, W.; Lehmann, A.; Uhlig, F.; Dobbs, S.; Metreveli, Z.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savriè, M.; Stancari, G.; Bianchi, N.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Orecchini, D.; Pace, E.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Bremer, D.; Dormenev, V.; Drexler, P.; Düren, M.; Eissner, T.; Föhl, K.; Galuska, M.; Gessler, T.; Hayrapetyan, A.; Hu, J.; Koch, P.; Kröck, B.; Kühn, W.; Lange, S.; Liang, Y.; Merle, O.; Metag, V.; Moritz, M.; Münchow, D.; Nanova, M.; Novotny, R.; Spruck, B.; Stenzel, H.; Ullrich, T.; Werner, M.; Xu, H.; Euan, C.; Hoek, M.; Ireland, D.; Keri, T.; Montgomery, R.; Protopopescu, D.; Rosner, G.; Seitz, B.; Babai, M.; Glazenborg-Kluttig, A.; Kavatsyuk, M.; Lemmens, P.; Lindemulder, M.; Löhner, H.; Messchendorp, J.; Moeini, H.; Schakel, P.; Schreuder, F.; Smit, H.; Tambave, G.; van der Weele, J. C.; Veenstra, R.; Sohlbach, H.; Büscher, M.; Deermann, D.; Dosdall, R.; Esch, S.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Henssler, S.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Kozlov, V.; Lehrach, A.; Maier, R.; Mertens, M.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Randriamalala, T.; Ritman, J.; Röder, M.; Schadmand, S.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Kisiel, J.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Fissum, S.; Hansen, K.; Isaksson, L.; Lundin, M.; Schröder, B.; Achenbach, P.; Bleser, S.; Cahit, U.; Cardinali, M.; Denig, A.; Distler, M.; Fritsch, M.; Jasinski, P.; Kangh, D.; Karavdina, A.; Lauth, W.; Merkel, H.; Michel, M.; Mora Espi, M. C.; Müller, U.; Pochodzalla, J.; Sanchez, S.; Sanchez-Lorente, A.; Schlimme, S.; Sfienti, C.; Thiel, M.; Weber, T.; Dormenev, V. I.; Fedorov, A. A.; Korzhik, M. V.; Missevitch, O. V.; Balanutsa, V.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Varentsov, V.; Boukharov, A.; Malyshev, O.; Marishev, I.; Semenov, A.; Böhmer, F.; Dørheim, S.; Ketzer, B.; Paul, S.; Hergemöller, A. K.; Khoukaz, A.; Köhler, E.; Täschner, A.; Wessels, J.; Varma, R.; Chaterjee, A.; Jha, V.; Kailas, S.; Roy, B. J.; Yan, Y.; Chinorat, K.; Khanchai, K.; Ayut, L.; Pomrad, S.; Baldin, E.; Kotov, K.; Peleganchuk, S.; Tikhonov, Yu.; Boucher, J.; Chambert, V.; Dbeyssi, A.; Gumberidze, M.; Hennino, T.; Imre, M.; Kunne, R.; Le Galliard, C.; Ma, B.; Marchand, D.; Maroni, A.; Ong, S.; Ramstein, B.; Rosier, P.; Tomasi-Gustafsson, E.; Van de Wiele, J.; Boca, G.; Braghieri, A.; Costanza, S.; Genova, P.; Lavezzi, L.; Montagna, P.; Rotondi, A.; Abramov, V.; Belikov, N.; Davidenko, A.; Derevschikov, A.; Goncharenko, Y.; Grishin, V.; Kachanov, V.; Konstantinov, D.; Kormilitsin, V.; Melnik, Y.; Levin, A.; Minaev, N.; Mochalov, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Bäck, T.; Cederwall, B.; Makónyi, K.; Tegnér, P. E.; von Würtemberg, K. M.; Belostotski, S.; Gavrilov, G.; Itzotov, A.; Kashchuk, A.; Kisselev, A.; Kravchenko, P.; Levitskaya, O.; Manaenkov, S.; Miklukho, O.; Naryshkin, Y.; Veretennikov, D.; Vikhrov, V.; Zhadanov, A.; Alberto, D.; Amoroso, A.; Bussa, M. P.; Busso, L.; De Mori, F.; Destefanis, M.; Fava, L.; Ferrero, L.; Greco, M.; Maggiora, M.; Marcello, S.; Sosio, S.; Spataro, S.; Zotti, L.; Calvo, D.; Coli, S.; De Remigis, P.; Filippi, A.; Giraudo, G.; Lusso, S.; Mazza, G.; Morra, O.; Rivetti, A.; Wheadon, R.; Iazzi, F.; Lavagno, A.; Younis, H.; Birsa, R.; Bradamante, F.; Bressan, A.; Martin, A.; Clement, H.; Galander, B.; Caldeira Balkeståhl, L.; Calén, H.; Fransson, K.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Thomé, E.; Wolke, M.; Zlomanczuk, J.; Díaz, J.; Ortiz, A.; Dmowski, K.; Duda, P.; Korzeniewski, R.; Slowinski, B.; Chlopik, A.; Guzik, Z.; Kosinski, K.; Melnychuk, D.; Wasilewski, A.; Wojciechowski, M.; Wronka, S.; Wysocka, A.; Zwieglinski, B.; Bühler, P.; Hartman, O. N.; Kienle, P.; Marton, J.; Suzuki, K.; Widmann, E.; Zmeskal, J.

    2013-02-01

    This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the overline{P}ANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole overline{P}ANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.

  5. FairMQ for Online Reconstruction - An example on \\overline{{\\rm{P}}}ANDA test beam data

    NASA Astrophysics Data System (ADS)

    Stockmanns, Tobias; PANDA Collaboration

    2017-10-01

    One of the large challenges of future particle physics experiments is the trend to run without a first level hardware trigger. The typical data rates exceed easily hundreds of GBytes/s, which is way too much to be stored permanently for an offline analysis. Therefore a strong data reduction has to be done by selection of only those data, which are physically interesting. This implies that all detector data are read out and have to be processed with the same rate as it is produced. Several different hardware approaches from FPGAs, GPUs to multicore CPUs and mixtures of these systems are under study. Common to all of them is the need to process the data in massive parallel systems. One very convenient way to realize parallel systems on heterogeneous systems is the usage of message queue based multiprocessing. One package that allow development of such application is the FairMQ module in the FairRoot simulation framework developed at GSI. FairRoot is used by several different experiments at and outside the GSI including the \\overline{{{P}}}ANDA experiment. FairMQ is an abstract layer for message queue base application, it has up to now two implementations: ZeroMQ and nanomsg. For the \\overline{{{P}}}ANDA experiment, FairMQ is under test in two different ways. On the one hand side for online processing test beam data of prototypes of sub-detectors of \\overline{{{P}}}ANDA and, in a more generalized way, on time-based simulated data of the complete detector system. The first test on test beam data is presented in this paper.

  6. Overview of the Micro Vertex Detector for the P bar ANDA experiment

    NASA Astrophysics Data System (ADS)

    Calvo, Daniela; P¯ANDA MVD Group

    2017-02-01

    The P bar ANDA experiment is devoted to study interactions between cooled antiproton beams and a fixed target (the interaction rate is of about 107 events/s), hydrogen or heavier nuclei. The innermost tracker of P bar ANDA is the Micro Vertex Detector (MVD), specially designed to ensure the secondary vertex resolution for the discrimination of short-lived charmonium states. Hybrid epitaxial silicon pixels and double-sided silicon microstrips will equip four barrels, arranged around the interaction point, and six forward disks. The experiment features a triggerless architecture with a master clock of 160 MHz, therefore the MVD has to run with a continuous data transmission where the hits need precise timestamps. The energy loss of the particles in the sensor will be measured as well. The challenging request of a triggerless readout suggested to develop custom readout chips for both pixel (ToPix) and microstrip (PASTA) devices. To validate components and the triggerless readout architecture, prototypes have been built and tested. After an overview of the MVD, the technological aspects and performances of some prototypes will be reported.

  7. The bar{P}ANDA Experiment at FAIR — Subatomic Physics with Antiprotons

    NASA Astrophysics Data System (ADS)

    Messchendorp, Johan

    The non-perturbative nature of the strong interaction leads to spectacular phenomena, such as the formation of hadronic matter, color confinement, and the generation of the mass of visible matter. To get deeper insight into the underlying mechanisms remains one of the most challenging tasks within the field of subatomic physics. The antiProton ANnihilations at DArmstadt (bar{P}ANDA) collaboration has the ambition to address key questions in this field by exploiting a cooled beam of antiprotons at the High Energy Storage Ring (HESR) at the future Facility for Antiproton and Ion Research (FAIR) combined with a state-of-the-art and versatile detector. This contribution will address some of the unique features of bar{P}ANDA that give rise to a promising physics program together with state-of-the-art technological developments.

  8. Experimental access to Transition Distribution Amplitudes with the P¯ANDA experiment at FAIR

    NASA Astrophysics Data System (ADS)

    Singh, B. P.; Erni, W.; Keshelashvili, I.; Krusche, B.; Steinacher, M.; Liu, B.; Liu, H.; Liu, Z.; Shen, X.; Wang, C.; Zhao, J.; Albrecht, M.; Fink, M.; Heinsius, F. H.; Held, T.; Holtmann, T.; Koch, H.; Kopf, B.; Kümmel, M.; Kuhl, G.; Kuhlmann, M.; Leyhe, M.; Mikirtychyants, M.; Musiol, P.; Mustafa, A.; Pelizäus, M.; Pychy, J.; Richter, M.; Schnier, C.; Schröder, T.; Sowa, C.; Steinke, M.; Triffterer, T.; Wiedner, U.; Beck, R.; Hammann, C.; Kaiser, D.; Ketzer, B.; Kube, M.; Mahlberg, P.; Rossbach, M.; Schmidt, C.; Schmitz, R.; Thoma, U.; Walther, D.; Wendel, C.; Wilson, A.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Pietreanu, D.; Vasile, M. E.; Patel, B.; Kaplan, D.; Brandys, P.; Czyzewski, T.; Czyzycki, W.; Domagala, M.; Hawryluk, M.; Filo, G.; Krawczyk, M.; Kwiatkowski, D.; Lisowski, E.; Lisowski, F.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Czech, B.; Kliczewski, S.; Korcyl, K.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Malgorzata, K.; Pysz, K.; Schäfer, W.; Siudak, R.; Szczurek, A.; Biernat, J.; Jowzaee, S.; Kamys, B.; Kistryn, S.; Korcyl, G.; Krzemien, W.; Magiera, A.; Moskal, P.; Palka, M.; Psyzniak, A.; Rudy, Z.; Salabura, P.; Smyrski, J.; Strzempek, P.; Wrońska, A.; Augustin, I.; Lehmann, I.; Nicmorus, D.; Schepers, G.; Schmitt, L.; Al-Turany, M.; Cahit, U.; Capozza, L.; Dbeyssi, A.; Deppe, H.; Dzhygadlo, R.; Ehret, A.; Flemming, H.; Gerhardt, A.; Götzen, K.; Karabowicz, R.; Kliemt, R.; Kunkel, J.; Kurilla, U.; Lehmann, D.; Lühning, J.; Maas, F.; Morales Morales, C.; Mora Espí, M. C.; Nerling, F.; Orth, H.; Peters, K.; Rodríguez Piñeiro, D.; Saito, N.; Saito, T.; Sánchez Lorente, A.; Schmidt, C. J.; Schwarz, C.; Schwiening, J.; Traxler, M.; Valente, R.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V. M.; Alexeev, G.; Arefiev, A.; Astakhov, V. I.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Yu. I.; Dodokhov, V. Kh.; Efremov, A. A.; Fedunov, A. G.; Festchenko, A. A.; Galoyan, A. S.; Grigoryan, S.; Karmokov, A.; Koshurnikov, E. K.; Lobanov, V. I.; Lobanov, Yu. Yu.; Makarov, A. F.; Malinina, L. V.; Malyshev, V. L.; Mustafaev, G. A.; Olshevskiy, A.; Pasyuk, M. A.; Perevalova, E. A.; Piskun, A. A.; Pocheptsov, T. A.; Pontecorvo, G.; Rodionov, V. K.; Rogov, Yu. N.; Salmin, R. A.; Samartsev, A. G.; Sapozhnikov, M. G.; Shabratova, G. S.; Skachkov, N. B.; Skachkova, A. N.; Strokovsky, E. A.; Suleimanov, M. K.; Teshev, R. Sh.; Tokmenin, V. V.; Uzhinsky, V. V.; Vodopyanov, A. S.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Woods, P.; Britting, A.; Eyrich, W.; Lehmann, A.; Uhlig, F.; Dobbs, S.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savriè, M.; Stancari, G.; Akishina, V.; Kisel, I.; Kulakov, I.; Zyzak, M.; Arora, R.; Bel, T.; Gromliuk, A.; Kalicy, G.; Krebs, M.; Patsyuk, M.; Zuehlsdorf, M.; Bianchi, N.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Pace, E.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Bianco, S.; Bremer, D.; Brinkmann, K. T.; Diehl, S.; Dormenev, V.; Drexler, P.; Düren, M.; Eissner, T.; Etzelmüller, E.; Föhl, K.; Galuska, M.; Gessler, T.; Gutz, E.; Hayrapetyan, A.; Hu, J.; Kröck, B.; Kühn, W.; Kuske, T.; Lange, S.; Liang, Y.; Merle, O.; Metag, V.; Mülhheim, D.; Münchow, D.; Nanova, M.; Novotny, R.; Pitka, A.; Quagli, T.; Rieke, J.; Rosenbaum, C.; Schnell, R.; Spruck, B.; Stenzel, H.; Thöring, U.; Ullrich, M.; Wasem, T.; Werner, M.; Zaunick, H. G.; Ireland, D.; Rosner, G.; Seitz, B.; Deepak, P. N.; Kulkarni, A. V.; Apostolou, A.; Babai, M.; Kavatsyuk, M.; Lemmens, P.; Lindemulder, M.; Löhner, H.; Messchendorp, J.; Schakel, P.; Smit, H.; van der Weele, J. C.; Tiemens, M.; Veenstra, R.; Vejdani, S.; Kalita, K.; Mohanta, D. P.; Kumar, A.; Roy, A.; Sahoo, R.; Sohlbach, H.; Büscher, M.; Cao, L.; Cebulla, A.; Deermann, D.; Dosdall, R.; Esch, S.; Georgadze, I.; Gillitzer, A.; Goerres, A.; Goldenbaum, F.; Grunwald, D.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Kozlov, V.; Lehrach, A.; Leiber, S.; Maier, R.; Nellen, R.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Prencipe, E.; Ritman, J.; Schadmand, S.; Schumann, J.; Sefzick, T.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Fissum, S.; Hansen, K.; Isaksson, L.; Lundin, M.; Schröder, B.; Achenbach, P.; Bleser, S.; Cardinali, M.; Corell, O.; Deiseroth, M.; Denig, A.; Distler, M.; Feldbauer, F.; Fritsch, M.; Jasinski, P.; Hoek, M.; Kangh, D.; Karavdina, A.; Lauth, W.; Leithoff, H.; Merkel, H.; Michel, M.; Motzko, C.; Müller, U.; Noll, O.; Plueger, S.; Pochodzalla, J.; Sanchez, S.; Schlimme, S.; Sfienti, C.; Steinen, M.; Thiel, M.; Weber, T.; Zambrana, M.; Dormenev, V. I.; Fedorov, A. A.; Korzihik, M. V.; Missevitch, O. V.; Balanutsa, P.; Balanutsa, V.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Varentsov, V.; Boukharov, A.; Malyshev, O.; Marishev, I.; Semenov, A.; Konorov, I.; Paul, S.; Grieser, S.; Hergemöller, A. K.; Khoukaz, A.; Köhler, E.; Täschner, A.; Wessels, J.; Dash, S.; Jadhav, M.; Kumar, S.; Sarin, P.; Varma, R.; Chandratre, V. B.; Datar, V.; Dutta, D.; Jha, V.; Kumawat, H.; Mohanty, A. K.; Roy, B.; Yan, Y.; Chinorat, K.; Khanchai, K.; Ayut, L.; Pornrad, S.; Barnyakov, A. Y.; Blinov, A. E.; Blinov, V. E.; Bobrovnikov, V. S.; Kononov, S. A.; Kravchenko, E. A.; Kuyanov, I. A.; Onuchin, A. P.; Sokolov, A. A.; Tikhonov, Y. A.; Atomssa, E.; Hennino, T.; Imre, M.; Kunne, R.; Le Galliard, C.; Ma, B.; Marchand, D.; Ong, S.; Ramstein, B.; Rosier, P.; Tomasi-Gustafsson, E.; Van de Wiele, J.; Boca, G.; Costanza, S.; Genova, P.; Lavezzi, L.; Montagna, P.; Rotondi, A.; Abramov, V.; Belikov, N.; Bukreeva, S.; Davidenko, A.; Derevschikov, A.; Goncharenko, Y.; Grishin, V.; Kachanov, V.; Kormilitsin, V.; Melnik, Y.; Levin, A.; Minaev, N.; Mochalov, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Yabsley, B.; Bäck, T.; Cederwall, B.; Makónyi, K.; Tegnér, P. E.; von Würtemberg, K. M.; Belostotski, S.; Gavrilov, G.; Izotov, A.; Kashchuk, A.; Levitskaya, O.; Manaenkov, S.; Miklukho, O.; Naryshkin, Y.; Suvorov, K.; Veretennikov, D.; Zhadanov, A.; Rai, A. K.; Godre, S. S.; Duchat, R.; Amoroso, A.; Bussa, M. P.; Busso, L.; De Mori, F.; Destefanis, M.; Fava, L.; Ferrero, L.; Greco, M.; Maggiora, M.; Maniscalco, G.; Marcello, S.; Sosio, S.; Spataro, S.; Zotti, L.; Calvo, D.; Coli, S.; De Remigis, P.; Filippi, A.; Giraudo, G.; Lusso, S.; Mazza, G.; Mingnore, M.; Rivetti, A.; Wheadon, R.; Balestra, F.; Iazzi, F.; Introzzi, R.; Lavagno, A.; Younis, H.; Birsa, R.; Bradamante, F.; Bressan, A.; Martin, A.; Clement, H.; Gålnander, B.; Caldeira Balkeståhl, L.; Calén, H.; Fransson, K.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Pettersson, J.; Schönning, K.; Wolke, M.; Zlomanczuk, J.; Díaz, J.; Ortiz, A.; Vinodkumar, P. C.; Parmar, A.; Chlopik, A.; Melnychuk, D.; Slowinski, B.; Trzcinski, A.; Wojciechowski, M.; Wronka, S.; Zwieglinski, B.; Bühler, P.; Marton, J.; Suzuki, K.; Widmann, E.; Zmeskal, J.; Fröhlich, B.; Khaneft, D.; Lin, D.; Zimmermann, I.; Semenov-Tian-Shansky, K.

    2015-08-01

    Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion ( πN) TDAs from reaction with the future P¯ANDA detector at the FAIR facility. At high center-of-mass energy and high invariant mass squared of the lepton pair q 2, the amplitude of the signal channel admits a QCD factorized description in terms of πN TDAs and nucleon Distribution Amplitudes (DAs) in the forward and backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring with the P¯ANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 < q 2 < 4.3 GeV2 and 5 < q 2 GeV2, respectively, with a neutral pion scattered in the forward or backward cone in the proton-antiproton center-of-mass frame. Results of the simulation show that the particle identification capabilities of the P¯ANDA detector will allow to achieve a background rejection factor of 5 · 107 (1 · 107) at low (high) q 2 for s = 5 GeV2, and of 1 · 108 (6 · 106) at low (high) q 2 for s = 10 GeV2, while keeping the signal reconstruction efficiency at around 40%. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 fb-1 of integrated luminosity. The cross sections obtained from the simulations are used to show that a test of QCD collinear factorization can be done at the lowest order by measuring scaling laws and angular distributions. The future measurement of the signal channel cross section with P¯ANDA will provide a new test of the perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing π TDAs.

  9. Online Tracking Algorithms on GPUs for the P̅ANDA Experiment at FAIR

    NASA Astrophysics Data System (ADS)

    Bianchi, L.; Herten, A.; Ritman, J.; Stockmanns, T.; Adinetz, A.; Kraus, J.; Pleiter, D.

    2015-12-01

    P̅ANDA is a future hadron and nuclear physics experiment at the FAIR facility in construction in Darmstadt, Germany. In contrast to the majority of current experiments, PANDA's strategy for data acquisition is based on event reconstruction from free-streaming data, performed in real time entirely by software algorithms using global detector information. This paper reports the status of the development of algorithms for the reconstruction of charged particle tracks, optimized online data processing applications, using General-Purpose Graphic Processing Units (GPU). Two algorithms for trackfinding, the Triplet Finder and the Circle Hough, are described, and details of their GPU implementations are highlighted. Average track reconstruction times of less than 100 ns are obtained running the Triplet Finder on state-of- the-art GPU cards. In addition, a proof-of-concept system for the dispatch of data to tracking algorithms using Message Queues is presented.

  10. Feasibility studies of time-like proton electromagnetic form factors at $$\\overline{\\rm P}$$ANDA at FAIR

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Singh, B.; Erni, W.; Krusche, B.

    Simulation results for future measurements of electromagnetic proton form factors atmore » $$\\overline{\\rm P}$$ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯p → e +e – is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e. p¯p → π +π –, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. Furthermore, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.« less

  11. Feasibility studies of time-like proton electromagnetic form factors at $$\\overline{\\rm P}$$ANDA at FAIR

    DOE PAGES

    Singh, B.; Erni, W.; Krusche, B.; ...

    2016-10-28

    Simulation results for future measurements of electromagnetic proton form factors atmore » $$\\overline{\\rm P}$$ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯p → e +e – is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e. p¯p → π +π –, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. Furthermore, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.« less

  12. Feasibility studies for the Forward Spectrometer

    NASA Astrophysics Data System (ADS)

    Biernat, Jacek; P¯ANDA Collaboration

    2015-04-01

    The Forward Spectrometer designed for the P¯ANDA detector will consist of many different detector systems allowing for precise track reconstruction and particle identification. Feasibility studies for Forward Spectrometer done by means of specific reactions will be presented. In the first part of the paper, results of simulations focussing on rate estimates of the tracking stations based on straw tubes will be presented. Next, the importance of the Forward Tracker will be demonstrated through the reconstruction of the ψ(4040) → DD¯ decay. Finally, results from the analysis of the experimental data collected with a straw tube prototype designed and constructed at the Research Center in Juelich will be discussed.

  13. 76 FR 33310 - Bristol-Myers Squibb Co. et al.; Withdrawal of Approval of 70 New Drug Applications and 97...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ..., Inc. ANDA 074634 Dobutamine Injection Hospira, Inc. USP, 12.5 mg/mL. ANDA 074643 Minoxidil Topical Bausch & Lomb, Inc. Solution, 2%. ANDA 074743 Minoxidil Topical Sight Solution, 2%. Pharmaceuticals, Inc...

  14. PANDA Muon System Prototype

    NASA Astrophysics Data System (ADS)

    Abazov, Victor; Alexeev, Gennady; Alexeev, Maxim; Frolov, Vladimir; Golovanov, Georgy; Kutuzov, Sergey; Piskun, Alexei; Samartsev, Alexander; Tokmenin, Valeri; Verkheev, Alexander; Vertogradov, Leonid; Zhuravlev, Nikolai

    2018-04-01

    The PANDA Experiment will be one of the key experiments at the Facility for Antiproton and Ion Research (FAIR) which is under construction now in the territory of the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. PANDA is aimed to study hadron spectroscopy and various topics of the weak and strong forces. Muon System is chosen as the most suitable technology for detecting the muons. The Prototype of the PANDA Muon System is installed on the test beam line T9 at the Proton Synchrotron (PS) at CERN. Status of the PANDA Muon System prototype is presented with few preliminary results.

  15. Regulatory considerations of pharmaceutical solid polymorphism in Abbreviated New Drug Applications (ANDAs).

    PubMed

    Raw, Andre S; Furness, M Scott; Gill, Devinder S; Adams, Richard C; Holcombe, Frank O; Yu, Lawrence X

    2004-02-23

    A sponsor of an Abbreviated New Drug Application (ANDA) must have information to show that the proposed generic product and the innovator product are both pharmaceutically equivalent and bioequivalent, and therefore, therapeutically equivalent. Many pharmaceutical solids exist in several crystalline forms and thus exhibit polymorphism. Polymorphism may result in differences in the physico-chemical properties of the active ingredient and variations in these properties may render a generic drug product to be bioinequivalent to the innovator brand. For this reason, in ANDAs, careful attention is paid to the effect of polymorphism in the context of generic drug product equivalency. This review discusses the impact of polymorphism on drug product manufacturability, quality, and performance. Conclusions from this analysis demonstrate that pharmaceutical solid polymorphism has no relevance to the determination of drug substance "sameness" in ANDAs. Three decision trees for solid oral dosage forms or liquid suspensions are provided for evaluating when and how polymorphs of drug substances should be monitored and controlled in ANDA submissions. Case studies from ANDAs are provided which demonstrate the irrelevance of polymorphism to the determination of drug substance "sameness". These case studies also illustrate the conceptual framework from these decision trees and illustrate how their general principles are sufficient to assure both the quality and the therapeutic equivalence of marketed generic drug products.

  16. Common Filing Deficiencies in Abbreviated New Drug Applications Containing Clinical Endpoint Studies.

    PubMed

    Fermaglich, Lewis J; Chen, Ru; Kim, Carol Y; Chuh, Eunjung Esther; Thomas, Teena; Shetty, Daiva; Lee, Julia; Young, Johnny; Fan, Ying

    2018-01-01

    The objective of this report is to summarize common deficiencies identified in the filing reviews of abbreviated new drug applications (ANDAs) with clinical endpoint bioequivalence studies and skin irritation, sensitization, and adhesion (I/S/A) studies received by the US Food and Drug Administration (FDA) between 2007 and 2017, to help applicants avoid common deficiencies, minimize "refuse-to-receive" (RTR) actions, "information requests," and ANDA approval delays. Multiple internal FDA databases were searched to evaluate and summarize common deficiencies identified in ANDA submissions containing clinical endpoint studies and skin I/S/A studies that required review by the Division of Clinical Review. A total of 275 ANDA submissions with filing reviews from January 2007 to June 2017 were analyzed in this report. Two hundred eighteen (79.3%) filing reviews contained one or more deficiencies. Seventy-nine (28.7%) ANDAs were issued RTR letters because of major clinical deficiencies, specifically bioequivalence and clinical deficiencies, accounting for 9% of overall identified deficiencies. Twenty-two other categories of deficiencies are summarized into 4 main categories: missing information related to the clinical studies other than data sets (38%), missing data sets (35%), formulation issues (12%), and organization/format issues (6%). The most common deficiency in the "missing information related to the clinical studies other than data sets" category was "missing clarification of information" (22%). We also noted that the Division of Filing Review has identified these same types of deficiencies since assuming responsibility of the filing assessment for ANDAs with clinical endpoint BE studies and skin I/S/A studies. In conclusion, to minimize "refuse-to-receive" actions, "information requests," and approval of ANDA delays for generic drug products, applicants should submit full clinical study reports, including all data sets for drug products recommending clinical studies.

  17. 77 FR 16039 - Abbott Laboratories et al.; Withdrawal of Approval of 35 New Drug Applications and 64 Abbreviated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-19

    ... Do. nitroprusside for Injection USP), 50 mg. ANDA 071015 Haloperidol Oral Teva Pharmaceuticals... 075065 Acyclovir Sodium for Do. Injection. ANDA 075176 Haloperidol Do. Decanoate Injection, 50 mg/mL and...

  18. Targeted Ablation of CML Stem Cells

    DTIC Science & Technology

    2007-01-01

    centuries .12 More recently, PTL has been found to have several other properties, including antitumor activity, inhibition of DNA synthesis, and...as a chemopreventive agent in a UVB-induced skin cancer animal model. 21 PTL is a potent inhibitor of NF-B activation and has been shown to directly...diluted in phosphate buffer saline (PBS). Ara-C was obtained from Sigma ( St Louis, MO). Total cell numbers were determined before and after culture for

  19. 76 FR 82302 - Determination That HYCODAN (Hydrocodone Bitartrate and Homatropine Methylbromide) Tablets, 5...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ... discontinued from marketing for reasons other than safety or effectiveness. ANDAs that refer to HYCODAN... Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug... effectiveness. This determination will allow FDA to approve abbreviated new drug applications (ANDAs) for...

  20. 76 FR 20357 - Determination That KEFLEX (Cephalexin) Capsule, Equivalent to 333 Milligrams Base, Was Not...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

    ... discontinued from marketing for reasons other than safety or effectiveness. ANDAs that refer to KEFLEX... for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice... effectiveness. This determination will allow FDA to approve abbreviated new drug applications (ANDAs) for...

  1. Variability of Hormonal Stress Markers and Stress Responses in a Large Cross-Sectional Sample of Elephant Seals

    DTIC Science & Technology

    2014-09-30

    hormones and function in elephant seals; 3) determine the impact of baseline variation in aldosterone on electrolyte balance in elephant seals; 4...may have broad implications for marine mammal species. Task 3 – Impact of aldosterone variability on osmolality Work on the Parent Project and...a parallel project on bottlenose dolphins has shown the importance of aldosterone as a stress hormone in marine mammals. Aldosterone covaries with

  2. 76 FR 44012 - Determination That NUVIGIL (Armodafinil) Tablets, 100 Milligrams and 200 Milligrams, Were Not...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-22

    ... Milligrams, Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug... effectiveness. This determination will allow FDA to approve abbreviated new drug applications (ANDAs) for... the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA determines that the listed...

  3. Completeness assessment of type II active pharmaceutical ingredient drug master files under generic drug user fee amendment: review metrics and common incomplete items.

    PubMed

    Zhang, Huyi; Li, Haitao; Song, Wei; Shen, Diandian; Skanchy, David; Shen, Kun; Lionberger, Robert A; Rosencrance, Susan M; Yu, Lawrence X

    2014-09-01

    Under the Generic Drug User Fee Amendments (GDUFA) of 2012, Type II active pharmaceutical ingredient (API) drug master files (DMFs) must pay a user fee and pass a Completeness Assessment (CA) before they can be referenced in an Abbreviated New Drug Application (ANDA), ANDA amendment, or ANDA prior approval supplement (PAS). During the first year of GDUFA implementation, from October 1, 2012 to September 30, 2013, approximately 1,500 Type II API DMFs received at least one cycle of CA review and more than 1,100 Type II DMFs were deemed complete and published on FDA's "Available for Reference List". The data from CA reviews were analyzed for factors that influenced the CA review process and metrics, as well as the areas of DMF submissions which most frequently led to an incomplete CA status. The metrics analysis revealed that electronic DMFs appear to improve the completeness of submission and shorten both the review and response times. Utilizing the CA checklist to compile and proactively update the DMFs improves the chance for the DMFs to pass the CA in the first cycle. However, given that the majority of DMFs require at least two cycles of CA before being deemed complete, it is recommended that DMF fees are paid 6 months in advance of the ANDA submissions in order to avoid negatively impacting the filling status of the ANDAs.

  4. Fully transparent, non-volatile bipolar resistive memory based on flexible copolyimide films

    NASA Astrophysics Data System (ADS)

    Yu, Hwan-Chul; Kim, Moon Young; Hong, Minki; Nam, Kiyong; Choi, Ju-Young; Lee, Kwang-Hun; Baeck, Kyoung Koo; Kim, Kyoung-Kook; Cho, Soohaeng; Chung, Chan-Moon

    2017-01-01

    Partially aliphatic homopolyimides and copolyimides were prepared from rel-(1'R,3S,5'S)-spiro[furan-3(2H),6'-[3]oxabicyclo[3.2.1]octane]-2,2',4',5(4H)-tetrone (DAn), 2,6-diaminoanthracene (AnDA), and 4,4'-oxydianiline (ODA) by varying the molar ratio of AnDA and ODA. We utilized these polyimide films as the resistive switching layer in transparent memory devices. While WORM memory behavior was obtained with the PI-A100-O0-based device (molar feed ratio of DAn : AnDA : ODA = 1 : 1 : 0), the PI-A70-O30-based device (molar feed ratio of DAn : AnDA : ODA = 1 : 0.7 : 0.3) exhibited bipolar resistive switching behavior with stable retention for 104 s. This result implies that the memory properties can be controlled by changing the polyimide composition. The two devices prepared from PI-A100-O0 and PI-A70-O30 showed over 90% transmittance in the visible wavelength range from 400 to 800 nm. The behavior of the memory devices is considered to be governed by trap-controlled, space-charge limited conduction (SCLC) and local filament formation. [Figure not available: see fulltext.

  5. Charm Production in Interactions of Antiproton with Proton and Nuclei at \\bar{it{P}}it{ANDA} Energies

    NASA Astrophysics Data System (ADS)

    Shyam, R.; Tsushima, K.

    2018-05-01

    We study the production of charmed baryons in the antiproton-proton and antiproton-nucleus interactions within a fully covariant model that is based on an effective Lagrangian approach. The baryon production proceeds via the t-channel D^0 and D^{*0} meson-exchange diagrams. We have also explored the production of the charm-baryon hypernucleus ^{16}_{Λ_c^+}O in the antiproton-^{16}O collisions. For antiproton beam momenta of interest to the {\\bar{P}}ANDA experiment, the 0° differential cross sections for the formation of ^{16}_{Λ_c^+}O hypernuclear states with simple particle-hole configurations, have magnitudes in the range of a few μ b/sr.

  6. Hypernuclear physics studies of the P̅ANDA experiment at FAIR

    NASA Astrophysics Data System (ADS)

    Sanchez Lorente, Alicia

    2015-05-01

    Hypernuclear research will be one of the main topics addressed by the PANDA experiment at the planned Facility for Antiproton and Ion Research FAIR at Darmstadt (Germany). [1, 2] Thanks to the use of stored p̅ beams, copious production of double Λ hypernuclei is expected at the PANDA experiment, which will enable high precision γ spectroscopy of such nuclei for the first time, and consequently a unique chance to explore the hyperon-hyperon interaction. In particular, ambiguities of past experiments in determining the strength of the ΛΛ interaction will be avoided thanks to the excellent energy precision of a few keV (FWHM) achieved by germanium detectors. Such a resolution capability is particularly needed to resolve the small energy spacing of the order of (10-100) keV, which is characteristic from the spin doublet in hypernuclei the so -called "hypernuclear fine structure". In comparison to previous experiments, PANDA will benefit from a novel technique to assign the various observable γ-transitions in a unique way to specific double hypernuclei by exploring various light targets. Nevertheless, the ability to carry out unique assignments requires a devoted hypernuclear detector setup. This consists of a primary nuclear target for the production of Ξ- + overline Xi pairs, a secondary active target for the hypernuclei formation and the identification of associated decay products and a germanium array detector to perform γ spectroscopy. Moreover, one of the most challenging issues of this project is the fact that all detector systems need to operate in the presence of a high magnetic field and a large hadronic background. Accordingly, the need of an innovative detector concept will require dramatic improvements to fulfil these conditions and that will likely lead to a new generation of detectors. In the present work details concerning the current status of the activities related to the detector developments for this challenging programme will be given. Among these improvements is the new concept for a cooling system for the germanium detector based on a electro-mechanical device. In the present work, the cooling efficiency of such devices has been successfully tested, showing their capability to reach liquid nitrogen temperatures and therefore the possibility to use them as a good alternative to the standard liquid nitrogen dewars. Furthermore, since the momentum resolution of low momentum particles is crucial for the unique identification of hypernuclei, an analysis procedure for improving the momentum resolution in few layer silicon based trackers is presented.

  7. A systematic study of the strong interaction with P-barANDA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Messchendorp, J. G.

    2011-10-21

    The theory of Quantum Chromo Dynamics (QCD) reproduces the strong interaction at distances much shorter than the size of the nucleon. At larger distance scales, the generation of hadron masses and confinement cannot yet be derived from first principles on basis of QCD. The PANDA experiment at FAIR will address the origin of these phenomena in controlled environments. Beams of antiprotons together with a multi-purpose and compact detection system will provide unique tools to perform studies of the strong interaction. This will be achieved via precision spectroscopy of charmonium and open-charm states, an extensive search for exotic objects such asmore » glueballs and hybrids, in-medium and hypernuclei spectroscopy, and more. An overview is given of the physics program of the P-barANDA collaboration.« less

  8. 78 FR 47321 - Determination That CYTOXAN (Cyclophosphamide) for Injection Was Not Withdrawn From Sale for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-05

    ..., Hodgkin's disease, lymphocytic lymphoma, mixed-cell type lymphoma, histiocytic lymphoma, Burkitt's... marketing for reasons other than safety or effectiveness. ANDAs that refer to CYTOXAN (cyclophosphamide) for...

  9. 75 FR 48742 - Renewal of the Regional Resource Stewardship Council Charter

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-11

    ... its natural resource stewardship activities through a balanced and broad range of diverse views and... for public input regarding stewardship issues. Dated: July 26, 2010. Anda A. Ray, Senior Vice...

  10. 78 FR 40484 - Determination That METADATE ER (Methylphenidate Hydrochloride) Extended-Release Tablet, 10...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-05

    ..., educational, social) for a stabilizing effect in children with a behavioral syndrome characterized by the... marketing for reasons other than safety or effectiveness. ANDAs that refer to METADATE ER (methylphenidate...

  11. 75 FR 10865 - Shoreline Management Initiative, Reservoirs in Alabama, Georgia, Kentucky, Mississippi, North...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... shoreline management zones, management of access/ view corridor size, use of best management practices for...: February 25, 2010. Anda Ray, Senior Vice President of Environment and Technology and Environmental...

  12. 76 FR 32258 - Meeting of the Regional Resource Stewardship Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-03

    ... Discussion and Advice. The RRSC will hear opinions and views of citizens by providing a public comment..., Knoxville, Tennessee 37902, (865) 632-6113. Dated: May 25, 2011. Anda A. Ray, Senior Vice President and...

  13. 77 FR 43337 - Drugs for Human Use; Drug Efficacy Study Implementation; Certain Prescription Drugs Offered for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    .... (now part of Kremers-Urban Pharmaceuticals, Inc., 902 Carnegie Center, Suite 360, Princeton, NJ 08540...-687) and Spasmolin (ANDA 86-655); Sandoz, Inc., 506 Carnegie Center, Suite 400, Princeton, NJ 08540...

  14. Solid Layer Thermal-conductivity Measurement Techniques

    DTIC Science & Technology

    1994-03-01

    deposited on the sample, and the absorption of laser radiation. Temperature-measurement tools include thermocouples, infrared (IR) pyrometers , and...A, Nishimura H, and Sawada T (1990), Laser-Induc~d Surface Acoustic Waves and Photothc:rmal Surfitce Gratings Generated by Crossing Two Pulsed

  15. 78 FR 73200 - Draft Guidance for Industry on Bioequivalence Recommendations for Paliperidone Palmitate Extended...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-05

    ... Paliperidone Palmitate Extended-Release Injectable Suspension; Availability AGENCY: Food and Drug...) studies to support abbreviated new drug applications (ANDAs) for paliperidone palmitate extended-release... the availability of revised draft BE recommendations for paliperidone palmitate extended-release...

  16. Economic Impacts of the Generic Drug User Fee Act Fee Structure.

    PubMed

    Dong, Ke; Boehm, Garth; Zheng, Qiang

    2017-06-01

    A Food and Drug Administration (FDA) Generic Drug User system, Generic Drug User Fee Amendment of 2012 (GDUFA), started October 1, 2012, and has been in place for over 3 years. There is controversy about the GDUFA fee structure but no analysis of GDUFA data that we could find. To look at the economic impact of the GDUFA fee structure. We compared the structure of GDUFA with that of other FDA Human Drug User fees. We then, using FDA-published information, analyzed where GDUFA facility and Drug Master File fees are coming from. We used the Orange Book to identify the sponsors of all approved Abbreviated New Drug Applications (ANDAs) and the S&P Capital IQ database to find the ultimate parent companies of sponsors of approved ANDAs. The key differences between the previous structure for Human Drug User fees and the GDUFA are as follows: GDUFA has no approved product fee and no first-time or small business fee exemptions and GDUFA charges facility fees from the time of filing and charges a foreign facility levy. Most GDUFA fees are paid by or on behalf of foreign entities. The top 10 companies hold nearly 50% of all approved ANDAs but pay about 14% of GDUFA facility fees. We conclude that the regressive nature of the GDUFA fee structure penalizes small, new, and foreign firms while benefiting the large established firms. A progressive fee structure in line with other human drug user fees is needed to ensure a healthy generic drug industry. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  17. Validation of the Thematic Mapper radiometric and geometric correction algorithms

    NASA Technical Reports Server (NTRS)

    Fischel, D.

    1984-01-01

    The radiometric and geometric correction algorithms for Thematic Mapper are critical to subsequent successful information extraction. Earlier Landsat scanners, known as Multispectral Scanners, produce imagery which exhibits striping due to mismatching of detector gains and biases. Thematic Mapper exhibits the same phenomenon at three levels: detector-to-detector, scan-to-scan, and multiscan striping. The cause of these variations has been traced to variations in the dark current of the detectors. An alternative formulation has been tested and shown to be very satisfactory. Unfortunately, the Thematic Mapper detectors exhibit saturation effects suffered while viewing extensive cloud areas, and is not easily correctable. The geometric correction algorithm has been shown to be remarkably reliable. Only minor and modest improvements are indicated and shown to be effective.

  18. 78 FR 52777 - Draft Guidance for Industry on Bioequivalence Recommendations for Risperidone Injection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-26

    ...] (Formerly Docket No. 2007D-0168) Draft Guidance for Industry on Bioequivalence Recommendations for... industry entitled ``Draft Guidance on Risperidone.'' The guidance provides specific recommendations on the design of bioequivalence (BE) studies to support abbreviated new drug applications (ANDAs) for...

  19. 77 FR 58399 - Draft Guidance for Industry on Bioequivalence Recommendations for Pentosan Polysulfate Sodium...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... Polysulfate Sodium Capsule; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY... entitled ``Bioequivalence Recommendations for Pentosan Polysulfate Sodium.'' The recommendations provide... (ANDAs) for pentosan polysulfate sodium capsule. DATES: Although you can comment on any guidance at any...

  20. 78 FR 63228 - Determination That Potassium Citrate, 10 Milliequivalents/Packet and 20 Milliequivalents/Packet...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... approved. ANDA applicants do not have to repeat the extensive clinical testing otherwise necessary to gain... mEq/packet and 20 mEq/packet, is the subject of NDA 19-647, held by Nova-K LLC, and initially...

  1. 76 FR 53907 - Determination That TALWIN COMPOUND (Aspirin; Pentazocine Hydrochloride) Tablets, 325 Milligrams...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ...] Determination That TALWIN COMPOUND (Aspirin; Pentazocine Hydrochloride) Tablets, 325 Milligrams; Equivalent to... determined that TALWIN COMPOUND (aspirin; pentazocine hydrochloride (HCl)) tablets, 325 milligrams (mg... determination will allow FDA to approve abbreviated new drug applications (ANDAs) for aspirin; pentazocine HCl...

  2. 78 FR 16685 - Impax Laboratories, Inc.; Withdrawal of Approval of Bupropion Hydrochloride Extended-Release...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-18

    ...] Impax Laboratories, Inc.; Withdrawal of Approval of Bupropion Hydrochloride Extended-Release Tablets... Administration (FDA) is withdrawing approval of Bupropion Hydrochloride (HCl) Extended-Release Tablets, 300 Milligrams (mg) (Bupropion HCl Extended-Release Tablets 300 mg), under Abbreviated New Drug Application (ANDA...

  3. 77 FR 56851 - Draft and Revised Draft Guidances for Industry Describing Product-Specific Bioequivalence...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-14

    ... Bioequivalence Recommendations; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY... draft product-specific bioequivalence (BE) recommendations. The recommendations provide product-specific guidance on the design of BE studies to support abbreviated new drug applications (ANDAs). In the Federal...

  4. 77 FR 18827 - Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose Injection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ...] Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose Injection; Availability... Recommendations for Iron Sucrose.'' The recommendations provide specific guidance on the design of bioequivalence (BE) studies to support abbreviated new drug applications (ANDAs) for iron sucrose injection. DATES...

  5. Probes, Surveys, and the Ontology of the Social

    ERIC Educational Resources Information Center

    Collins, Harry; Evans, Robert

    2017-01-01

    By distinguishing between a survey and--a newly introduced term--a "probe," we recast the relationship between qualitative and quantitative approaches to social science. The difference turns on the "uniformity" of the phenomenon being examined. Uniformity is a fundamental idea underlying all scientific research but is rarely…

  6. High Resolution PET Imaging Probe for the Detection, Molecular Characterization and Treatment Monitoring of Prostate Cancer

    DTIC Science & Technology

    2012-07-01

    number of high resolution PET experiments including the dual-ring small field- of-view configuration shown at left in Figure 5 . The benchtop system...detectors having 26 x 40 arrays of 1mm x 1mm x 1mm detector elements is shown at right in Figure 5 . Detectors used for probe experiments shown in...Figure 13). In the series of experiments geared towards PET application, but with the results applicable to the present single gamma case, we have

  7. RNAi mediated, stable resistance to Triticum mosaic virus in wheat

    USDA-ARS?s Scientific Manuscript database

    Triticum mosaic virus (TriMV), discovered in 2006, affects wheat production systems in the Great Plains of the United States. There are no available TriMV resistant commercial varieties. RNA interference (RNAi) was evaluated as an alternative strategy to generate resistance to TriMV. An RNAi pANDA...

  8. 76 FR 19997 - Determination That FENTORA (Fentanyl Citrate) Buccal Tablet, 300 Micrograms, Was Not Withdrawn...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-11

    ...] Determination That FENTORA (Fentanyl Citrate) Buccal Tablet, 300 Micrograms, Was Not Withdrawn From Sale for... Food and Drug Administration (FDA) has determined that FENTORA (fentanyl citrate) buccal tablet, 300... allow FDA to approve abbreviated new drug applications (ANDAs) for fentanyl citrate buccal tablet, 300...

  9. Dynamic Information Networks: Geometry, Topology and Statistical Learning for the Articulation of Structure

    DTIC Science & Technology

    2015-06-23

    T. Bates, S. Brocklebank, S. Pauls, and D.Rockmore, A spectral clustering approach to the structure of personality: contrasting the FFM and...A spectral clustering approach to the structure of personality: contrasting the FFM and HEXACO models, Journal of Research in Personality, Volume 57

  10. MOAtox: A Comprehensive Mode of Action and Acute Aquatic Toxicity Database for Predictive Model Development

    EPA Science Inventory

    tThe mode of toxic action (MOA) has been recognized as a key determinant of chemical toxicity andas an alternative to chemical class-based predictive toxicity modeling. However, the development ofquantitative structure activity relationship (QSAR) and other models has been limite...

  11. 77 FR 7585 - Draft Guidance for Industry on Bioequivalence Recommendations for Rifaximin Tablets; Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-13

    ... (rifaximin-550). The recommendations provide specific guidance on the design of bioequivalence (BE) studies... studies to support ANDAs for rifaximin-200 (Draft Rifaximin-200 BE Recommendations). FDA is now issuing a...] Draft Guidance for Industry on Bioequivalence Recommendations for Rifaximin Tablets; Availability AGENCY...

  12. 75 FR 33311 - Guidance for Industry on Bioequivalence Recommendations for Specific Products; Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ... available recommendations on how to design product- specific bioequivalence (BE) studies to support... meaningful opportunity for the public to consider and comment on product-specific BE study recommendations... available recommendations on how to design product-specific BE studies to support ANDAs. Under this process...

  13. 78 FR 20925 - Draft and Revised Draft Guidances for Industry Describing Product-Specific Bioequivalence...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ... Recommendations; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and...-specific bioequivalence (BE) recommendations. The recommendations provide product-specific guidance on the design of BE studies to support abbreviated new drug applications (ANDAs). In the Federal Register of...

  14. 77 FR 35688 - Draft and Revised Draft Guidances for Industry Describing Product-Specific Bioequivalence...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-14

    ... Recommendations; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and...-specific bioequivalence (BE) recommendations. The recommendations provide product-specific guidance on the design of BE studies to support abbreviated new drug applications (ANDAs). In the Federal Register of...

  15. 77 FR 16842 - Draft and Revised Draft Guidances for Industry Describing Product-Specific Bioequivalence...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-22

    ... Recommendations; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and...-specific bioequivalence (BE) recommendations. The recommendations provide product-specific guidance on the design of BE studies to support abbreviated new drug applications (ANDAs). In the Federal Register of...

  16. A Randomized Clinical Trial of Allopregnanolone for the Treatment of Severe Traumatic Brain Injury

    DTIC Science & Technology

    2012-10-01

    product, including assay, impurity/degradant levels, sterility results, pyrogenicity results, pH, 6 osmolality and particulates; stability data and...as a function of Glasgow Outcome Score. J Clin Exp Neuropsychol 20:270-279. Rogawski MA, Reddy DS (2004) Neurosteroids: Endogenous modulators of

  17. 77 FR 23269 - Determination That FUNDUSCEIN-25 (fluorescein sodium injection), 25%, and AK-FLUOR (fluorescein...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-18

    ...] Determination That FUNDUSCEIN-25 (fluorescein sodium injection), 25%, and AK-FLUOR (fluorescein sodium injection... FUNDUSCEIN-25 (fluorescein sodium injection), 25%, and AK-FLUOR (fluorescein sodium injection), 25%, were not... abbreviated new drug applications (ANDAs) for fluorescein sodium injection, 25%, if all other legal and...

  18. 78 FR 63227 - Determination That INTAL (cromolyn sodium) Inhalation Capsule, 20 Milligrams, Was Not Withdrawn...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ...] Determination That INTAL (cromolyn sodium) Inhalation Capsule, 20 Milligrams, Was Not Withdrawn From Sale for... Food and Drug Administration (FDA) has determined that INTAL (cromolyn sodium) Inhalation Capsule, 20... allow FDA to approve abbreviated new drug applications (ANDAs) for cromolyn sodium inhalation capsule...

  19. Doctrine Development Process in the Kenya Army: Bridging the Gap

    DTIC Science & Technology

    2014-06-13

    concepts, and principles . It must broadly follow three doctrine development phases: the collection/information gathering phase; the formulation and...a capable lead organization. The organization must eliminate terminological and utility confusion among doctrine, concepts, and principles . It must...15 The relationship Between Military Doctrine, Concept and Principle

  20. Mechanoelectrically Activated Synthesis of Dense, Bulk Nanostructured, Complex Crystalline and Glassy Hard Materials

    DTIC Science & Technology

    2005-04-01

    Facultad de Quimica , Universidad Autonoma de Queretaro, Queretaro, Mexico, May 7, 2002. (Invited Seminar) "* Recent Advances in the Synthesis and...A. Munir, 14o Congresso Brasileiro de Engenharia e Ciencias dos Materiais (14th Brazilian Congress on Materials Science and Engineering), Sao Pedro

  1. Identification of Risk Factors for Exertional Heat Illness: A Brief Commentary on Genetic Testing

    DTIC Science & Technology

    2007-01-01

    RYR1) gene and other genes related to disorders of skeletal muscle. Data Synthesis : EHI is a complex disorder wherein physiological, environmental, and...a life-threatening, hypermetabolic syndrome, known as a fulminant MH episode; similar (rare) events can be induced by high environmental temperatures

  2. "Not Censorship but Selection": Censorship and/as Prizing

    ERIC Educational Resources Information Center

    Kidd, Kenneth

    2009-01-01

    This essay calls for a fresh critical approach to the topic of censorship, suggesting that anticensorship efforts, while important and necessary, function much like literary prizing. The analysis draws especially on James English's recent study "The Economy of Prestige." There are two central arguments: first, that the librarian ethic of…

  3. Earth's magnetic field as a radiator to detect cosmic ray electrons of energy greater than 10 to the 12th power eV

    NASA Technical Reports Server (NTRS)

    Stephens, S. A.; Balasubrahmanyan, V. K.

    1983-01-01

    The synchrotron emission by electrons of energy greater than a few TeV in Earth's magnetic field was examined. An omnidirectional detector, it is shown, can be satisfactorily used to estimate the energy. The collecting power of the detector, it is also shown, is a sensitive function of the area of the detector, the energy of electron, and the number of photons required to identify an electron. The event rate expected was calculated using an ideal balloon-borne detector.

  4. 76 FR 3144 - Draft Guidance for Industry on Size of Beads in Drug Products Labeled for Sprinkle; Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... can be sprinkled on soft foods and swallowed without chewing as an alternative administration... parameters are considered in this draft guidance as they relate to drug products labeled for sprinkle: (1... size differences between reference listed drugs and ANDAs and meet bioavailability (BA) or...

  5. 75 FR 55796 - Determination That VESANOID (Tretinoin) Capsules, 10 Milligrams, Were Not Withdrawn From Sale for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-14

    ...] Determination That VESANOID (Tretinoin) Capsules, 10 Milligrams, Were Not Withdrawn From Sale for Reasons of... Drug Administration (FDA) has determined that VESANOID (tretinoin) Capsules, 10 milligrams (mg), were... approved. FDA may not approve an ANDA that does not refer to a listed drug. VESANOID (tretinoin) Capsules...

  6. 76 FR 54473 - Guidance on Positron Emission Tomography Drug Applications-Content and Format for New Drug...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... (formerly Docket No. 00D-0892)] Guidance on Positron Emission Tomography Drug Applications-- Content and... the availability of a guidance for industry entitled ``PET Drug Applications--Content and Format for... guidance for industry entitled ``PET Drug Applications--Content and Format for NDAs and ANDAs.'' The...

  7. Performance Models of Testability.

    DTIC Science & Technology

    1984-08-01

    4.1.17 Cost of Isolating Component/Part (CPI) 5J Cost of isolating components or parts at the depot is at CPI - n1 (HDC)(TPI)(NPI) where TPI = average...testing component N Deec N a aiur Yes(PFD D)S Cos ofi oaig op nn -- Cost ofcmpnn rmva n relaemn Exece Cost of omponn reatmovae anda

  8. 78 FR 52931 - Draft Guidance for Industry on Abbreviated New Drug Applications: Stability Testing of Drug...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-27

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-D-0938] Draft Guidance for Industry on Abbreviated New Drug Applications: Stability Testing of Drug Substances... Products, Questions and Answers.'' Because of increases in the number and complexity of ANDAs and FDA's...

  9. 78 FR 37231 - Guidance for Industry; Guidance on Abbreviated New Drug Applications: Stability Testing of Drug...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-20

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-D-0938] Guidance for Industry; Guidance on Abbreviated New Drug Applications: Stability Testing of Drug Substances....'' Because of increases in the number and complexity of ANDAs and FDA's desire to standardize generic drug...

  10. Writing Center Administration and/as Emotional Labor

    ERIC Educational Resources Information Center

    Jackson, Rebecca; McKinney, Jackie Grutsch; Caswell, Nicole I.

    2016-01-01

    Scholars have offered research and theory about emotional labor and the feeling of emotion in rhetoric and composition, but we have little if any such research on writing center work specifically. Drawing on data from a year-long qualitative study of writing center directors' labor, this article examines writing center directors' emotional labor…

  11. 76 FR 12916 - Benzocaine; Weight Control Drug Products for Over-the-Counter Human Use

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-09

    ... endpoint. Reports purporting to be two studies by Collipp (one published and one unpublished) were..., OTC weight control drug products containing benzocaine will require an approved NDA or ANDA. Studies...., a manufacturer of OTC weight control drug products, submitted two citizen petitions, one in 1990 and...

  12. 78 FR 35038 - Determination That CORDRAN (Flurandrenolide) Ointment USP, 0.025% and 0.05%, Were Not Withdrawn...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... been discontinued from marketing for reasons other than safety or effectiveness. ANDAs that refer to... Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The...% and 0.05%, were not withdrawn from sale for reasons of safety or effectiveness. This determination...

  13. 75 FR 69088 - Determination That Amphetamine Sulfate, 5 and 10 Milligram Tablets, Was Not Withdrawn From Sale...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-10

    ... products that have been discontinued from marketing for reasons other than safety or effectiveness. ANDAs... Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and... not withdrawn from sale for reasons of safety or effectiveness. This determination will allow FDA to...

  14. 77 FR 7583 - Determination That WILPO (phentermine hydrochloride) Tablets, 8 Milligrams, Was Not Withdrawn...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-13

    ... discontinued from marketing for reasons other than safety or effectiveness. ANDAs that refer to WILPO... Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The... Milligrams (mg), was not withdrawn from sale for reasons of safety or effectiveness. This determination will...

  15. 75 FR 51080 - Determination That DIASTAT (Diazepam Rectal Gel), 5 Milligrams/Milliliter, 10 Milligrams/2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug... effectiveness. This determination will allow FDA to approve abbreviated new drug applications (ANDAs) for... effectiveness, or if FDA determines that the listed drug was withdrawn from sale for reasons of safety or...

  16. 77 FR 25720 - Determination That GRIFULVIN V (Griseofulvin Microcrystalline) Tablets, 250 Milligrams, Was Not...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-01

    ... been discontinued from marketing for reasons other than safety or effectiveness. ANDAs that refer to... Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice... microcrystalline) tablets, 250 milligrams (mg), was not withdrawn from sale for reasons of safety or effectiveness...

  17. 76 FR 75886 - Determination That DEMULEN 1/50-28 (Ethinyl Estradiol; Ethynodiol Diacetate) Tablet and Four...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ... marketing for reasons other than safety or effectiveness. Approved ANDAs that refer to the NDAs listed in... Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug... effectiveness. This determination means that FDA will not begin procedures to withdraw approval of abbreviated...

  18. 76 FR 28045 - Determination That XIBROM (Bromfenac Ophthalmic Solution) 0.09% Was Not Withdrawn From Sale for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-13

    ... marketing for reasons other than safety or effectiveness. ANDAs that refer to XIBROM (bromfenac ophthalmic... Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and... withdrawn from sale for reasons of safety or effectiveness. This determination will allow FDA to approve...

  19. 78 FR 63228 - Determination That PARAFLEX (Chlorzoxazone) Tablets, 250 Milligrams, Was Not Withdrawn From Sale...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... products that have been discontinued from marketing for reasons other than safety or effectiveness. ANDAs... Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and...), was not withdrawn from sale for reasons of safety or effectiveness. This determination will allow FDA...

  20. 75 FR 11549 - Determination That PRO-BANTHINE (Propantheline Bromide) Tablets and 14 Other Drug Products Were...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-11

    ... marketing for reasons other than safety or effectiveness. Approved ANDAs that refer to the NDAs listed in... From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION... in this document were not withdrawn from sale for reasons of safety or effectiveness. This...

  1. 77 FR 29665 - Determination That PITRESSIN TANNATE IN OIL (Vasopressin Tannate) Injection, 5 Pressor Units...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-18

    ... Withdrawn From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION... safety or effectiveness. This determination will allow FDA to approve abbreviated new drug applications... suspends approval of the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA determines...

  2. 77 FR 53892 - Determination That ALOXI (Palonosetron Hydrochloride) Capsules, 0.5 Milligram (Base), Were Not...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-04

    ... discontinued from marketing for reasons other than safety or effectiveness. ANDAs that refer to ALOXI... Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice...)) Capsules, 0.5 milligram (mg) (base), were not withdrawn from sale for reasons of safety or effectiveness...

  3. 77 FR 35985 - Determination That PARAPLATIN (Carboplatin) Injection and SUSTIVA (Efavirenz) Capsules Were Not...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice... document were not withdrawn from sale for reasons of safety or effectiveness. This determination means that... the drug's NDA or ANDA for reasons of safety or effectiveness, or if FDA determines that the listed...

  4. 75 FR 10805 - Determination That DOVONEX (Calcipotriene) Ointment, 0.005%, Was Not Withdrawn From Sale for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... marketing for reasons other than safety or effectiveness. ANDAs that refer to DOVONEX (calcipotriene... From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION... (calcipotriene) Ointment, 0.005%, was not withdrawn from sale for reasons of safety or effectiveness. This...

  5. 76 FR 11487 - Determination That NILSTAT (Nystatin Powder (Oral, 100%)) Was Not Withdrawn From Sale for Reasons...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-02

    ... that have been discontinued from marketing for reasons other than safety or effectiveness. ANDAs that... Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug... reasons of safety or effectiveness. This determination will allow FDA to approve abbreviated new drug...

  6. 77 FR 16036 - Determination That CITANEST (Prilocaine Hydrochloride) Injection, 1%, 2%, and 3%, and CITANEST...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-19

    ... marketing for reasons other than safety or effectiveness. ANDAs that refer to CITANEST (prilocaine HCl... Hydrochloride) Injection, 4%, Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness AGENCY: Food... (prilocaine HCl) Injection, 4%, were not withdrawn from sale for reasons of safety or effectiveness. This...

  7. 77 FR 14810 - Determination That DURANEST (Etidocaine Hydrochloride) Injection, 0.5%, and Five Other DURANEST...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-13

    ... marketing for reasons other than safety or effectiveness. ANDAs that refer to any of the DURANEST drug... Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug... reasons of safety or effectiveness. This determination will allow FDA to approve abbreviated new drug...

  8. 75 FR 14444 - Determination That DIDREX (Benzphetamine Hydrochloride) Tablets, 25 Milligrams, Were Not...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-25

    ... Milligrams, Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug... safety or effectiveness. This determination will allow FDA to approve abbreviated new drug applications... or suspends approval of the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA...

  9. 78 FR 6823 - Determination That DIFFERIN (Adapalene) Solution, 0.1%, Was Not Withdrawn From Sale for Reasons...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-31

    ... discontinued from marketing for reasons other than safety or effectiveness. ANDAs that refer to DIFFERIN... Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug... sale for reasons of safety or effectiveness. This determination will allow FDA to approve abbreviated...

  10. 77 FR 7586 - Draft Guidance for Industry on Bioequivalence Recommendation for Nitroglycerin Metered Spray...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-13

    ... though we have not requested comparative in vitro studies, in vitro studies outlined in the 2002 guidance.... The recommendations provide specific guidance on the design of bioequivalence (BE) studies to support... draft guidance for industry on the Agency's recommendations for BE studies to support ANDAs for...

  11. 76 FR 32366 - Determination That ORLAAM (Levomethadyl Acetate Hydrochloride) Oral Solution, 10 Milligrams...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-06

    ...) Oral Solution, 10 Milligrams/Milliliter, Was Not Withdrawn From Sale for Reasons of Safety or... milligrams (mg)/milliliter (mL), was not withdrawn from sale for reasons of safety or effectiveness. This... the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA determines that the listed...

  12. 78 FR 38053 - Determination That OPANA ER (Oxymorphone Hydrochloride) Drug Products Covered by New Drug...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-25

    ...] Determination That OPANA ER (Oxymorphone Hydrochloride) Drug Products Covered by New Drug Application 21-610... (oxymorphone hydrochloride (HCl)) Extended-Release Tablet products approved under new drug application (NDA) 21... refer to these drug products, and it will allow FDA to continue to approve ANDAs for oxymorphone HCl...

  13. The Future of Dance and/as Work: Performing Precarity

    ERIC Educational Resources Information Center

    Van Assche, Annelies

    2017-01-01

    This article explores how and to what extent precarity is intertwined with a contemporary dance artist's labour, life and art in the neoliberal society. Throughout this investigation my arguments are supported by insights from an on-going qualitative study that uses in-depth interviews and observations of working processes within the Brussels…

  14. 75 FR 61503 - Determination That AZDONE (Hydrocodone Bitartrate and Aspirin) Tablet, 5 Milligrams/500...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ...] Determination That AZDONE (Hydrocodone Bitartrate and Aspirin) Tablet, 5 Milligrams/500 Milligrams, Was Not... bitartrate and aspirin) Tablet, 5 milligrams (mg)/ 500 mg, was not withdrawn from sale for reasons of safety... (ANDAs) for hydrocodone bitartrate and aspirin tablet, 5 mg/500 mg, if all other legal and regulatory...

  15. Absolute linearity measurements on a gold-black-coated deuterated L-alanine-doped triglycine sulfate pyroelectric detector.

    PubMed

    Theocharous, E

    2008-07-20

    The nonlinearity characteristics of a commercially available deuterated L-alanine-doped triglycine sulfate (DLATGS) pyroelectric detector were experimentally investigated at high levels of illumination using the National Physical Laboratory detector linearity characterization facility. The detector was shown to exhibit a superlinear response at high levels of illumination. Moreover, the linearity factor was shown to depend on the area of the spot on the detector active area being illuminated, i.e., the incident irradiance. Possible reasons for the observed behavior are proposed and discussed. The temperature coefficient of the response of the DLATGS pyroelectric detector was measured and found to be higher than +2.5% degrees C(-1). This large and positive temperature coefficient of response is the most likely cause of the superlinear behavior of the DLATGS pyroelectric detector.

  16. Multiple Frequency Parametric Sonar

    DTIC Science & Technology

    2015-09-28

    300003 1 MULTIPLE FREQUENCY PARAMETRIC SONAR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and...a method for increasing the bandwidth of a parametric sonar system by using multiple primary frequencies rather than only two primary frequencies...2) Description of Prior Art [0004] Parametric sonar generates narrow beams at low frequencies by projecting sound at two distinct primary

  17. 78 FR 27971 - Determination That REV-EYES (Dapiprazole Hydrochloride Ophthalmic Solution), 0.5%, Was Not...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-13

    ...] Determination That REV-EYES (Dapiprazole Hydrochloride Ophthalmic Solution), 0.5%, Was Not Withdrawn From Sale.... SUMMARY: The Food and Drug Administration (FDA) has determined that REV-EYES (dapiprazole hydrochloride... CFR 314.161)). FDA may not approve an ANDA that does not refer to a listed drug. REV-EYES (dapiprazole...

  18. Bands and/as Music Education: Antinomies and the Struggle for Legitimacy

    ERIC Educational Resources Information Center

    Mantie, Roger

    2012-01-01

    This article serves to extend a critique initiated by Allsup and Benedict in their 2008 PMER article, "The Problems of Band." Using the work of Michael Foucault as a theoretical and methodological basis, I consider ways in which today's large ensemble paradigm, particularly that of the wind band, has resulted in an ongoing antinomy in…

  19. Dumbing down and the Politics of Neoliberalism in Film and/as Media Studies

    ERIC Educational Resources Information Center

    Ginsberg, Terri

    2003-01-01

    Film scholars are facing widespread pressures to desist from teaching modes of analytic and theoretical discourse that were once considered important to fostering critical understandings of moving-image culture, but which have since been denigrated as either too difficult (i.e., "elitist") or too controlling (i.e., "totalizing")--or both--in the…

  20. 76 FR 53908 - Determination That OPANA ER (Oxymorphone Hydrochloride) Extended-Release Tablets, 7.5 Milligrams...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug... milligrams (mg) and 15 mg, were not withdrawn from sale for reasons of safety or effectiveness. This... approval of the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA determines that the...

  1. 77 FR 12309 - Determination That PHENURONE (Phenacemide) Tablet, 500 Milligrams, Was Not Withdrawn From Sale...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    ... Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and... not withdrawn from sale for reasons of safety or effectiveness. This determination will allow FDA to... withdraws or suspends approval of the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA...

  2. 75 FR 64310 - Determination That BUSPAR (Buspirone Hydrochloride) Tablets, 10 Milligrams, 15 Milligrams, and 30...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ..., Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug... reasons of safety or effectiveness. This determination means that FDA will not begin procedures to... withdraws or suspends approval of the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA...

  3. 76 FR 59141 - Determination That LOXITANE (Loxapine Succinate) Capsules and Three Other Drug Products Were Not...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-23

    ... Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice... document were not withdrawn from sale for reasons of safety or effectiveness. This determination means that... approval of the drug's NDA or ANDA for reasons of safety or effectiveness, or if FDA determines that the...

  4. 78 FR 17933 - Determination That BENADRYL (diphenhydramine hydrochloride) Injection and Two Other Drug Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ... Withdrawn From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION... effectiveness. This determination means that FDA will not begin procedures to withdraw approval of abbreviated... withdraws or suspends approval of the drug's NDA or ANDA for reasons of safety or effectiveness, or if FDA...

  5. 75 FR 48352 - Determination That MOTRIN (Ibuprofen) Tablets and Four Other Drug Products Were Not Withdrawn...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-10

    ... Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The... were not withdrawn from sale for reasons of safety or effectiveness. This determination means that FDA... approval of the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA determines that the...

  6. 75 FR 81617 - Determination That TRANDATE (Labetalol Hydrochloride) Tablets, 300 Milligrams and 400 Milligrams...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ... Withdrawn From Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION... effectiveness. This determination means that FDA will not begin procedures to withdraw approval of abbreviated... withdraws or suspends approval of the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA...

  7. 76 FR 9789 - Determination That Theophylline Oral Solution, 80 Milligrams/15 Milliliters, Was Not Withdrawn...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-22

    ... Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The...)/15 milliliters (mL), was not withdrawn from sale for reasons of safety or effectiveness. This... the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA determines that the listed...

  8. Investigation of the Progressive Bi-Level Coding Technique for the High- Resolution Bi-Level Data Compression Standard

    DTIC Science & Technology

    1990-07-01

    DOEdistribution categories from the Standard Distribution for Block 5. Funding Numbers. To include contract Unclassified Scientific and Technical and...a de -,sgee,-cnW iga danim -mihikihnct i "Erglit a n dr -. hviilchkan mi nu deike saitudwniesc rdn i u unLklvvrc mie rdrermlhe mSneahofc g~inttn ere

  9. 78 FR 67365 - Determination That Adderall (Amphetamine Aspartate; Amphetamine Sulfate; Dextroamphetamine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-12

    ...; Dextroamphetamine Sulfate) Tablet and 13 Other Drug Products Were Not Withdrawn From Sale for Reasons of Safety or... withdrawn from sale for reasons of safety or effectiveness. This determination means that FDA will not begin... suspends approval of the drug's NDA or ANDA for reasons of safety or effectiveness, or if FDA determines...

  10. Superconducting Detectors for Study of Infant Universe

    NASA Image and Video Library

    2014-03-17

    The BICEP2 telescope at the South Pole used a specialized array of superconducting detectors to capture polarized light from billions of years ago. The detector array is shown here, under a microscope.

  11. Monitoring Technology Proliferation: An Open Source Methodology For Generating Proliferation Intelligence

    DTIC Science & Technology

    1993-12-01

    72 D. MINES AND THE MILITARY-TECHNOLOGICAL REVOLUTION ...................................... 74 E. CUSTOMIZING THE TDD PROLIFERATION MARKET M...Data Storage & Peripherals - Systems Managmnt Technologies 4. Passive Sensors - Sensors and Signal Processing 5. Photonics - Electronic and...a reproducible procedure to allow customization of the model, provides the "guts" of the method. 18 Third, because they are not optimized for

  12. Affect and/as Collective Resistance in a Post-Truth Moment

    ERIC Educational Resources Information Center

    Castro Samayoa, Andrés; Nicolazzo, Z

    2017-01-01

    In this piece, we call upon the value of coalitional politics as a strategy of resistance in the face of an increasingly powerful post-truth regime. Reflecting on the insidious effects of fact-denying discourses are echoed in our classrooms and in our roles as educators, we openly wonder: What might it mean for educators to use feelings as a guide…

  13. 77 FR 9944 - Determination That REQUIP XL (Ropinerole Hydrochloride) Extended-Release Tablets, 3 Milligrams...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... Parkinson's disease. REQUIP XL (ropinerole hydrochloride) extended-release tablets, 3 mg, are currently... amendments include what is now section 505(j)(7) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 355(j... suspends approval of the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA determines...

  14. A Diet, Physical Activity, and Meditation Intervention in Men With Rising Prostate-Specific Antigen (PSA)

    DTIC Science & Technology

    2006-05-01

    AD_________________ Award Number: DAMD17-03-1-0139 TITLE: A Diet , Physical Activity, and...A Diet , Physical Activity, and Meditation Intervention in Men With Rising Prostate- 5a. CONTRACT NUMBER Specific Antigen (PSA...favorably affected by an intensive, vegetable-based diet , plus physical activity and mindfulness-based stress reduction. This randomized trial will

  15. Harmonizable Processes: Structure.

    DTIC Science & Technology

    1980-11-05

    Grothendieck and Pietsch , for * the work below. Definition 5.2 Let 1,4 be a pair of Banach spaces andas usual, B(1,4) be the space of bounded linear...IP)P P i=l I - (58) xi E 1, 1 i < n , n where x* E 1* , the adjoint space of I The following result of Grothendieck- Pietsch with a short proof may

  16. Microsoft PowerPoint - ANDA-Webinar-Nov-2016-v4-CN yic. ...

    Center for Drug Evaluation (CDER)

    ... Julia Lee 药学博士 美国食品药品管理局（ FDA） ... 点击可看到相关信息 : ... 点击此链接进行评估和获得证书 了解 CDER 小型企业和行业协助处的其他资源 : ...

  17. Asbestos Workshop: Sampling, Analysis, and Risk Assessment

    DTIC Science & Technology

    2012-03-01

    coatings Vinyl/asbestos floor tile Automatic transmission components Clutch facings Disc brake pads Drum brake linings Brake blocks Commercial and...A naturally-occurring pliant and fibrous mineral with heat-resistant properties • Serpentine Class: joint compound,‘popcorn’ceilings, brake pads...fabrics, and is used in fire-resistant and insulating materials such as brake linings. The asbestos minerals include chrysotile (white asbestos) and

  18. Grounding Vision through Experimental Manipulation

    DTIC Science & Technology

    2002-01-01

    Speculatrix" by their creator to emphasise their exploratory behaviour , described as: "it explores its environment actively, persistently, systematically...as most animals do" (Walter, 1950). These robots had very simple control circuitry, and their behaviour depended greatly on the morphology and...a long developing process. More studies are needed though to ascertain how the dorsal pathway (action) influences the ventral (perception) both in

  19. The Ethics of Science and/as Research: Deconstruction and the Orientations of a New Academic Responsibility

    ERIC Educational Resources Information Center

    Trifonas, Peter

    2003-01-01

    The principle of reason "as principle of grounding, foundation or institution" has tended to guide the science of research toward techno-practical ends. From this epistemic superintendence of the terms of knowledge and inquiry, there has arisen the traditional notion of academic responsibility that is tied to the pursuit of truth via a conception…

  20. 2007 Kneller Lecture, AESA Getting Lost: Social Science and/as Philosophy

    ERIC Educational Resources Information Center

    Lather, Patti

    2009-01-01

    This article probes how philosophical structures are immanent in empirical work and how philosophy might be understood when it is within the precincts of science. My interest is in both opening philosophy to disruption by a science that knows itself as inside history and opening science to the costs of its inability to tolerate the necessary lack…

  1. Sanofi Pharmaceuticals, Inc., et al.; withdrawal of approval of 21 new drug applications and 62 abbreviated new drug applications--FDA. Notice.

    PubMed

    1998-05-12

    The Food and Drug Administration (FDA) is withdrawing approval of 21 new drug applications (NDA's) and 62 abbreviated new drug applications (ANDA's). The holders of the applications notified the agency in writing that the drug products were no longer marketed and requested that the approval of the applications be withdrawn.

  2. Russia’s Reactions to the Color Revolutions

    DTIC Science & Technology

    2017-03-01

    Democratic Institute NGO non -governmental organization ODIHR Office for Democratic Institutions and Human Rights OSCE Organization for Security and...as the United States and other Western partners continue their tradition of promoting democracy and encouraging non -governmental organization (NGO...Ukraine as genuinely popular and indigenous upheavals, largely ignoring the role of U.S. funding and U.S. non -governmental organisations in

  3. 77 FR 51816 - Notice of Opportunity To Withdraw Abbreviated New Drug Applications To Avoid Backlog Fee Obligations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-27

    ...] Notice of Opportunity To Withdraw Abbreviated New Drug Applications To Avoid Backlog Fee Obligations... to avoid paying a fee. The fee in question is a one-time backlog fee that was established through enactment of the Generic Drug User Fee Amendments of 2012 (GDUFA). It will apply to any original ANDA that...

  4. Applications for approval to market a new drug; complete response letter; amendments to unapproved applications. Final rule.

    PubMed

    2008-07-10

    The Food and Drug Administration (FDA) is amending its regulations on new drug applications (NDAs) and abbreviated new drug applications (ANDAs) for approval to market new drugs and generic drugs (drugs for which approval is sought in an ANDA). The final rule discontinues FDA's use of approvable letters and not approvable letters when taking action on marketing applications. Instead, we will send applicants a complete response letter to indicate that the review cycle for an application is complete and that the application is not ready for approval. We are also revising the regulations on extending the review cycle due to the submission of an amendment to an unapproved application and starting a new review cycle after the resubmission of an application following receipt of a complete response letter. In addition, we are adding to the regulations on biologics license applications (BLAs) provisions on the issuance of complete response letters to BLA applicants. We are taking these actions to implement the user fee performance goals referenced in the Prescription Drug User Fee Amendments of 2002 (PDUFA III) that address procedures and establish target timeframes for reviewing human drug applications.

  5. Measuring partial fluorescence yield using filtered detectors.

    PubMed

    Boyko, T D; Green, R J; Moewes, A; Regier, T Z

    2014-07-01

    Typically, X-ray absorption near-edge structure measurements aim to probe the linear attenuation coefficient. These measurements are often carried out using partial fluorescence yield techniques that rely on detectors having photon energy discrimination improving the sensitivity and the signal-to-background ratio of the measured spectra. However, measuring the partial fluorescence yield in the soft X-ray regime with reasonable efficiency requires solid-state detectors, which have limitations due to the inherent dead-time while measuring. Alternatively, many of the available detectors that are not energy dispersive do not suffer from photon count rate limitations. A filter placed in front of one of these detectors will make the energy-dependent efficiency non-linear, thereby changing the responsivity of the detector. It is shown that using an array of filtered X-ray detectors is a viable method for measuring soft X-ray partial fluorescence yield spectra without dead-time. The feasibility of this technique is further demonstrated using α-Fe2O3 as an example and it is shown that this detector technology could vastly improve the photon collection efficiency at synchrotrons and that these detectors will allow experiments to be completed with a much lower photon flux reducing X-ray-induced damage.

  6. Infrared responsivity of a pyroelectric detector with a single-wall carbon nanotube coating.

    PubMed

    Theocharous, E; Engtrakul, C; Dillon, A C; Lehman, J

    2008-08-01

    The performance of a 10 mm diameter pyroelectric detector coated with a single-wall carbon nanotube (SWCNT) was evaluated in the 0.8 to 20 microm wavelength range. The relative spectral responsivity of this detector exhibits significant fluctuations over the wavelength range examined. This is consistent with independent absorbance measurements, which show that SWCNTs exhibit selective absorption bands in the visible and near-infrared. The performance of the detector in terms of noise equivalent power and detectivity in wavelength regions of high coating absorptivity was comparable with gold-black-coated pyroelectric detectors based on 50 microm thick LiTaO(3) crystals. The response of this detector was shown to be nonlinear for DC equivalent photocurrents >10(-9) A, and its spatial uniformity of response was comparable with other pyroelectric detectors utilizing gold-black coatings. The nonuniform spectral responsivity exhibited by the SWCNT-coated detector is expected to severely restrict the use of SWCNTs as black coatings for thermal detectors. However, the deposition of SWCNT coatings on a pyroelectric crystal followed by the study of the prominence of the spectral features in the relative spectral responsivity of the resultant pyroelectric detectors is shown to provide an effective method for quantifying the impurity content in SWCNT samples.

  7. IUE detector saturation and the new 2800 A absorption feature 'discovered' by Karim, Hoyle, and Wickramasinghe

    NASA Astrophysics Data System (ADS)

    Savage, B. D.; Sitko, M. L.

    1984-03-01

    The 2800 A feature of Karim et al. (1983) is shown to be the result of IUE detector saturation effects in overexposed spectra. A properly exposed spectrum and an overexposed one are shown. The latter shows a broad absorption peak at 2800 A while the former does not.

  8. Wigs, laughter, and subversion: Charles Busch and strategies of drag performance.

    PubMed

    Niles, Richard

    2004-01-01

    This paper examines the strategies of drag performer/ playwright Charles Busch. His performance aesthetic is explored and shown to be subversive even though its initial impulse is to entertain. Basing my arguments on the work of Judith Butler, Elin Diamond, and others, I argue that drag queens like Busch can not only entertain but also make audiences question and criticize through drag's power to create a Brechtian alienation effect and historicize the subject. After showing how he can be viewed as a drag queen, I give a brief biography and discuss such contested terms as "camp" and "gay sensibility." I then focus on Busch's staged reading of Ibsen's Hedda Gahler andA Doll's House, both done in one afternoon at Theatre for The New City (6 May 2000). By examining the performance of Busch and his fellow actors, I demonstrate how a contemporary relevancy is achieved by having the roles played by a female impersonator whose acting choices are filtered through a gay sensibility. The ongoing dialectic between spectator and performer creates a historicized moment in performance that underscores the gender dynamics in unexpected and stimulating ways.

  9. Naval Medical Research and Development News. Volume 7, Issue 11, November 2015

    DTIC Science & Technology

    2015-11-01

    enteric diseases such as shigellosis and typhoid fever . The goal of the laboratory is to research, understand, and develop protective strategies...military or public health significance in the region, including malaria and dengue fever , yellow fever , viral encephalitis, leishmaniasis, and...a food and waterborne disease, is characterized by fever , cramps and sometimes severe bloody diarrhea,” said Cmdr. Christopher Duplessis, lead

  10. Identification of Microbial Gene Biomarkers for in situ RDX Biodegradation

    DTIC Science & Technology

    2012-12-01

    Additional research is required to determine reliable guidelines to inform site managers of specific field concentrations of ammonium and nitrate...Mrs. Cynthia L. Price, Research Biologist, EPED, EL, ERDC; Dr. Rick Arnseth, Project Manager / Geochemist, Tetra Tech Inc., Oak Ridge, TN; and...a biomarker of RDX degradation, as it will also be necessary for bioremediation site managers to measure soil and groundwater concentra- tions for

  11. A Comparative Analysis of Unit Cohesion in Vietnam

    DTIC Science & Technology

    2014-06-13

    the political process, and result in a communist government; this became known as the Domino Theory . The United States replaced the French and...a theory of linkage; leveraging the political ties of Communist countries, namely the USSR and China, to influence North Vietnam, and deterrence; a...and Henderson provide some of the more popular theories about cohesion. Winkler points out that the relationship between stability, cohesion and

  12. Combinatorial and Algorithmic Rigidity: Beyond Two Dimensions

    DTIC Science & Technology

    2012-12-01

    problem. Manuscript, 2010. [35] G. Panina and I. Streinu. Flattening single-vertex origami : the non- expansive case. Computational Geometry : Theory and...in 2008, under the DARPA solicitation “Mathemat- ical Challenges, BAA 07-68”. It addressed Mathematical Challenge Ten: Al- gorithmic Origami and...a number of optimal algorithms and provided critical complexity analysis. The topic of algorithmic origami was successfully engaged from the same

  13. Analysis of Non-Pivotal Bioequivalence Studies Submitted in Abbreviated New Drug Submissions for Delayed-Release Drug Products.

    PubMed

    Kaur, Paramjeet; Jiang, Xiaojian; Stier, Ethan

    2017-01-01

    The US FDA's rule on "Requirements for Submission of Bioequivalence Data" requiring submission of all bioequivalence (BE) studies conducted on the same formulation of the drug product submitted for approval was published in Federal Register in January 2009. With the publication of this rule, we evaluated the impact of data from non-pivotal BE studies in assessing BE and identified the reasons for failed in vivo BE studies for generic oral delayed-release (DR) drug products only. We searched the Agency databases from January 2009 toDecember 2016 to identify Abbreviated New Drug Applications (ANDAs) submitted for DR drug products containing non-pivotal BE studies. Out of 202 ANDAs, 43 ANDAs contained 102 non-pivotal BE studies. Forty-nine non-pivotal BE studies were conducted on the to-be-marketed (TBM) formulation and 53 were conducted on formulations different from the TBM formulation. These experimental formulations primarily differed in the ratio of components of the enteric coating layer and/or amount (i.e., %w/w) of enteric coating layer. Of the 49 non-pivotal BE studies conducted on the TBM formulation, 41 failed to meet the BE acceptance criteria. The majority of failed non-pivotal BE studies on the TBM DR generic products had insufficient power, which was expected as these studies are exploratory in nature and not designed to have adequate power to pass the BE statistical criteria. In addition, among the failed non-pivotal BE studies on the TBM DR generic products, the most commonly failing pharmacokinetic parameter was Cmax. The data from these non-pivotal BE studies indicate that inadequate BE study design can lead to failure of the BE on the same formulation. Also, the non-pivotal BE studies on formulations different from the TBM formulation help us link the formulation design to the product performance in vivo. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

  14. DQE as detection probability of the radiation detectors

    NASA Astrophysics Data System (ADS)

    Zanella, Giovanni

    2008-02-01

    In this paper it is shown that quantum efficiency (DQE), as commonly defined for imaging detectors, can be extended to all radiation detectors with the meaning of detection probability, if Poisson statistics applies. This unified approach is possible in time-domain at zero spatial-frequency.

  15. Energy straggling eliminated as a limitation to charge resolution of transmission detectors. [used for particle identification

    NASA Technical Reports Server (NTRS)

    Tarle, G.; Ahlen, S. P.; Price, P. B.

    1981-01-01

    It is pointed out that detectors of the energy loss of penetrating charged particles are widely used for particle identification. These measurements are hampered, however, by fluctuations in the amount of energy deposited within the detector. It is shown that this limitation can be overcome with a new nuclear track detector, CR-39(DOP), and that the charge resolution of this detector exceeds that of any other, including semiconductor diodes.

  16. Integrated detector array technology for infrared astronomy

    NASA Technical Reports Server (NTRS)

    Mccreight, c. R.; Goebel, J. H.; Mckelvey, M. E.; Stafford, P. S.; Lee, J. H.

    1984-01-01

    The status of laboratory and telescope tests of integrated infrared detector array technology for astronomical applications is described. The devices tested represent a number of extrinsic and intrinsic detector materials and various multiplexer designs. Infrared arrays have now been used in successful astronomical applications. These have shown that device sensitivities can be comparable to those of discrete detector systems and excellent astronomical imagery can be produced.

  17. AutoMap User’s Guide 2011

    DTIC Science & Technology

    2011-06-13

    important links. Dave likes milk and cookies but John likes cauliflower 107 The example sentence above contains nine concepts. Manually reviewing this...sentence reveals that milk and cookies are associated with Dave and cauliflower is associated with John. But using a direction of unidirectional and...a window size of 9 results in cauliflower also being associated with Dave. 18 JAN 10 GUI Section The AutoMap GUI is a graphic interface for

  18. The China-Africa Connection: Implications for United States Foreign Policy

    DTIC Science & Technology

    1992-06-01

    a Independencia total de Angola(UNITA) UNITA Governo Revolucionhrio de Angola _.. ... no Exillo LGRAE) GRAE Mozambique Frente de Liberta;&o de ...Moqambique (FRELIMO) FRELIMO Comite Revolucionhrio de ,, Mocambigue (COREMO) COREMO Portuguese Partido Africano da Independencia Guinea da Guind e Cabo Verde...Postgraduate School Naval Postgraduate School NS _-. ’E_ ADURESSb (UIly, MStae, anda 2P c- de ) 71). ADDRESS (GiIy, SMate, and/-JP Code) Monterey, CA 93943

  19. Quantifying Stellar Mass Loss with High Angular Resolution Imaging

    DTIC Science & Technology

    2009-02-19

    material – via massive winds, planetary nebulae and supernova explosions – seeding the interstellar medium with heavier elements. Subsequent...of Planetary Nebulae (Harpaz, ApJ, 498,293, (1998)), impacts the pre-explosion characteristic of SNII (Taylor, “The Stars”, Cambridge (1994)), and...A 464, 119) or may have an important role, such as Be Stars, W-R stars, and planetary nebulae . The Future of Interferometric O/IR Imaging. The

  20. Animal Models of Jet Lag

    DTIC Science & Technology

    2012-01-20

    surgically inserted into the pineal gland and connected to a peristaltic pump that delivers saline solution at low rate and to a outlet tubing that delivers...Journal of Pineal Research. 48(3):290- 6,2010. 2. "Orcadian Regulation of Pineal Gland Rhythmicity", Jimo Borjigin, L. Samantha Zhang, Anda-Alexandra...specializes in the longitudinal monitoring of pineal melatonin secretion for weeks at a time to decipher mechanisms of circadian pacemaker entrainment

  1. New Cathode Material for High Energy-Density Batteries

    DTIC Science & Technology

    1974-07-31

    Lithium Anodes LINK A ROLK LINK B LINK C INSTRUCTIONS I. ORIGINATING ACTIVITY: Enter the name and oddM-ss of the contractor...theoretical energy density of 399 whr/lb when paired with a lithium anode. Results of related, but less extensive, work on zinc fluoride and...a) The semiconductor was cathodically passi- vated in the presence of lithium ions, which would normally exist in lithium battery electrolytes

  2. A Development Model for Foreign Police

    DTIC Science & Technology

    2014-06-13

    automated fingerprint identification system. And lastly, it sought to provide training to Malian and other regional police on countering money laundering and...A DEVELOPMENT MODEL FOR FOREIGN POLICE A thesis presented to the Faculty of the U.S. Army Command and General Staff College in...13-06-2014 2. REPORT TYPE Master’s Thesis 3. DATES COVERED (From - To) AUG 2013 – JUNE 2014 4. TITLE AND SUBTITLE A DEVELOPMENT MODEL FOR

  3. Outsourcing Information Technology and the Insider Threat

    DTIC Science & Technology

    2003-03-01

    the insider threat. However, “are of little value for examining complex social relationships or intricate patterns of interaction ” (Marshall and...As the previous section indicated, U.S. relations with the rest of the world will have some bearing over the social interactions , trends, and psyches...advances that bring economic and social issues into focus in a media rich environment. Technology trends have given organizations the ability to

  4. Perspectives on Defense Futures: National Developments in Europe

    DTIC Science & Technology

    1986-04-01

    little danger of coming apart at the seam in the next 10 years, fiscal constraints on improving defenses will be a dominant environmental factor and...a source of further intra- Alliance frictions. European maritime forces, in particular, will feel the effects of a fiscally corseted planning...EXECUTIVE SUMMARY EUROPE IN THE LATE 198Qs sets the context with a brief survey of the political, fiscal , and force modernization challenges

  5. Calibration of Attenuation Structure in Eurasia to Improve Discrimination and Yield

    DTIC Science & Technology

    2010-09-01

    and travel-times over large and tectonically complicated regions. As a result regional discrimination methods (e.g., high-frequency P/S, Ms:mb) and...a poor job of predicting both regional amplitudes and travel-times over large and tectonically complicated regions. As a result regional...regions. Earthquake-explosion discrimination using high-frequency regional P/S amplitude ratios over large and tectonically complicated regions can only

  6. 76 FR 37129 - Determination That SODIUM FLUORIDE F 18 (Sodium Fluoride F-18) Injection, 10 to 200 Millicuries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-24

    ...] Determination That SODIUM FLUORIDE F 18 (Sodium Fluoride F-18) Injection, 10 to 200 Millicuries per Milliliter... FLUORIDE F 18 (sodium fluoride F-18) injection, 10 to 200 millicuries per milliliter (mCi/mL), was not... abbreviated new drug applications (ANDAs) for SODIUM FLUORIDE F 18 injection, 10 to 200 mCi/mL, if all other...

  7. Short-Sighted Probabilistic Planning

    DTIC Science & Technology

    2013-08-01

    2005). The 1st Probabilistic Track of the International Planning Competition. Journal of Artificial Intelli - gence Research, 24(1):851–887. [Zhou and...A short-sighted problem is a relaxed problem in which the state space of the original problem is pruned and artificial goals are added to...A short-sighted problem is a relaxed problem in which the state space of the original problem is pruned and artificial goals are added to heuris

  8. High-throughput SANS experiment on two-detector system of YuMO spectrometer

    NASA Astrophysics Data System (ADS)

    Kuklin, A. I.; Ivankov, A. I.; Soloviov, D. V.; Rogachev, A. V.; Kovalev, Yu S.; Soloviev, A. G.; Islamov, A. Kh; Balasoiu, M.; Vlasov, A. V.; Kutuzov, S. A.; Sirotin, A. P.; Kirilov, A. S.; Skoi, V. V.; Rulev, M. I.; Gordeliy, V. I.

    2018-03-01

    Using a multidetector system on the YuMO spectrometer allows shortening the time of measurements. The quantitative comparison of the measurement time using one and two-detector mode is done. The time range for experiments was from several minutes up to 12 hours. It was shown that two-detector system shortens more than twice the time of the measurement. While making a structural investigation using advanced software the two-detector system allows to treat the data at a qualitatively new level. An example illustrating the features of the channels choice and measurement time on the spectrometer was shown. The results of this paper could be used when planning the experiments on the YuMO spectrometer, for modernization of the installation and for equipment using time-of-flight method.

  9. Identification of stopping ions in a silicon Timepix detector

    NASA Astrophysics Data System (ADS)

    Stoffle, Nicholas; Pinsky, Lawrence

    2018-02-01

    Timepix detectors are increasingly used in space-based applications. Such detectors are low power, low mass, and provide a wealth of information necessary for characterizing the ionizing radiation environment in space for both humans and hardware. Stopping ions are shown to contribute to the energy loss spectrum in a thin, pixelated, Timepix detector, and this energy loss is shown to contribute to the LET spectrum near 14 keV/micron. Bulk data also indicates the presence of Hydrogen isotopes in the energy loss spectra. Individual track analysis can be used to identify the stopping ions and the related energy and isotope through comparison with theoretical energy loss curves. While this calculation is specific to the Timepix, the impact of stopping ions on other instruments can be estimated using the insight gained from this approach.

  10. An ultra-thin Schottky diode as a transmission particle detector for biological microbeams.

    PubMed

    Grad, Michael; Harken, Andrew; Randers-Pehrson, Gerhard; Attinger, Daniel; Brenner, David J

    2012-12-01

    We fabricated ultrathin metal-semiconductor Schottky diodes for use as transmission particle detectors in the biological microbeam at Columbia University's Radiological Research Accelerator Facility (RARAF). The RARAF microbeam can deliver a precise dose of ionizing radiation in cell nuclei with sub-micron precision. To ensure an accurate delivery of charged particles, the facility currently uses a commercial charged-particle detector placed after the sample. We present here a transmission detector that will be placed between the particle accelerator and the biological specimen, allowing the irradiation of samples that would otherwise block radiation from reaching a detector behind the sample. Four detectors were fabricated with co-planar gold and aluminum electrodes thermally evaporated onto etched n-type crystalline silicon substrates, with device thicknesses ranging from 8.5 μm - 13.5 μm. We show coincident detections and pulse-height distributions of charged particles in both the transmission detector and the commercial detector above it. Detections are demonstrated at a range of operating conditions, including incoming particle type, count rate, and beam location on the detectors. The 13.5 μm detector is shown to work best to detect 2.7 MeV protons (H + ), and the 8.5 μm detector is shown to work best to detect 5.4 MeV alpha particles ( 4 He ++ ). The development of a transmission detector enables a range of new experiments to take place at RARAF on radiation-stopping samples such as thick tissues, targets that need immersion microscopy, and integrated microfluidic devices for handling larger quantities of cells and small organisms.

  11. An ultra-thin Schottky diode as a transmission particle detector for biological microbeams

    PubMed Central

    Harken, Andrew; Randers-Pehrson, Gerhard; Attinger, Daniel; Brenner, David J.

    2013-01-01

    We fabricated ultrathin metal-semiconductor Schottky diodes for use as transmission particle detectors in the biological microbeam at Columbia University’s Radiological Research Accelerator Facility (RARAF). The RARAF microbeam can deliver a precise dose of ionizing radiation in cell nuclei with sub-micron precision. To ensure an accurate delivery of charged particles, the facility currently uses a commercial charged-particle detector placed after the sample. We present here a transmission detector that will be placed between the particle accelerator and the biological specimen, allowing the irradiation of samples that would otherwise block radiation from reaching a detector behind the sample. Four detectors were fabricated with co-planar gold and aluminum electrodes thermally evaporated onto etched n-type crystalline silicon substrates, with device thicknesses ranging from 8.5 μm – 13.5 μm. We show coincident detections and pulse-height distributions of charged particles in both the transmission detector and the commercial detector above it. Detections are demonstrated at a range of operating conditions, including incoming particle type, count rate, and beam location on the detectors. The 13.5 μm detector is shown to work best to detect 2.7 MeV protons (H+), and the 8.5 μm detector is shown to work best to detect 5.4 MeV alpha particles (4He++). The development of a transmission detector enables a range of new experiments to take place at RARAF on radiation-stopping samples such as thick tissues, targets that need immersion microscopy, and integrated microfluidic devices for handling larger quantities of cells and small organisms. PMID:24058378

  12. An investigation of noise performance in optical lock-in thermography

    NASA Astrophysics Data System (ADS)

    Rajic, Nik; Antolis, Cedric

    2017-12-01

    An investigation into the noise performance of optical lock-in thermography (OLT) is described. The study aims to clarify the influence of infrared detector type and key inspection parameters such as illumination strength and lock-in duration on the quality of OLT amplitude and phase imagery. The study compares the performance of a state-of-the-art cooled photon detector with several lower-cost microbolometers. The results reveal a significant noise performance advantage to the photon detector. Under certain inspection regimes the advantage with respect to phase image quality is disproportionately high relative to detector sensitivities. This is shown to result from an explicit dependence in the phase signal variance on the ratio between the signal amplitude and the detector sensitivity. While this finding supports the preferred use of photon detectors for OLT inspections, it does not exclude microbolometers from a useful role. In cases where the significantly lower capital cost and improved practicality of microbolometers provide an advantage it is shown that performance shortfalls can be overcome with a relatively small factorial increase in optical illumination intensity.

  13. High-sensitivity fast neutron detector KNK-2-7M

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Koshelev, A. S., E-mail: alexsander.coshelev@yandex.ru; Dovbysh, L. Ye.; Ovchinnikov, M. A.

    2015-12-15

    The construction of the fast neutron detector KNK-2-7M is briefly described. The results of the study of the detector in the pulse-counting mode are given for the fissions of {sup 237}Np nuclei in the radiator of the neutron-sensitive section and in the current mode with the separation of sectional currents of functional sections. The possibilities of determining the effective number of {sup 237}Np nuclei in the radiator of the neutronsensitive section are considered. The diagnostic possibilities of the detector in the counting mode are shown by example of the analysis of the reference data from the neutron-field characteristics in themore » working hall of the BR-K1 reactor. The diagnostic possibilities of the detector in the current operating mode are shown by example of the results of measuring the {sup 237}Np-fission intensity in the BR-K1 reactor power start-ups implemented in the mode of fission-pulse generation on delayed neutrons at the detector arrangement inside the reactor core cavity under conditions of a wide variation of the reactor radiation field.« less

  14. Low dark current InGaAs detector arrays for night vision and astronomy

    NASA Astrophysics Data System (ADS)

    MacDougal, Michael; Geske, Jon; Wang, Chad; Liao, Shirong; Getty, Jonathan; Holmes, Alan

    2009-05-01

    Aerius Photonics has developed large InGaAs arrays (1K x 1K and greater) with low dark currents for use in night vision applications in the SWIR regime. Aerius will present results of experiments to reduce the dark current density of their InGaAs detector arrays. By varying device designs and passivations, Aerius has achieved a dark current density below 1.0 nA/cm2 at 280K on small-pixel, detector arrays. Data is shown for both test structures and focal plane arrays. In addition, data from cryogenically cooled InGaAs arrays will be shown for astronomy applications.

  15. Validation of Harris Detector and Eigen Features Detector

    NASA Astrophysics Data System (ADS)

    Kok, K. Y.; Rajendran, P.

    2018-05-01

    Harris detector is one of the most common features detection for applications such as object recognition, stereo matching and target tracking. In this paper, a similar Harris detector algorithm is written using MATLAB and the performance is compared with MATLAB built in Harris detector for validation. This is to ensure that rewritten version of Harris detector can be used for Unmanned Aerial Vehicle (UAV) application research purpose yet can be further improvised. Another corner detector close to Harris detector, which is Eigen features detector is rewritten and compared as well using same procedures with same purpose. The simulation results have shown that rewritten version for both Harris and Eigen features detectors have the same performance with MATLAB built in detectors with not more than 0.4% coordination deviation, less than 4% & 5% response deviation respectively, and maximum 3% computational cost error.

  16. Composition Studies with the Telescope Array Surface Detector

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Mikhail; Piskunov, Maxim; Rubtsov, Grigory; Troitsky, Sergey; Zhezher, Yana

    The results on ultra-high-energy cosmic-ray chemical composition based on the data from the Telescope Array surface-detector are presented. The method is based on the multivariate boosted decision tree (BDT) analysis which uses surface-detector observables. The results on average atomic mass in the energy range 1018.0-1020.0 eV are presented. A comparison with the Telescope Array hybrid results and the Pierre Auger Observatory surface detector results is shown.

  17. Problems on the Theory of Heat Resistance of Alloys

    DTIC Science & Technology

    1960-07-26

    same material under real service conditions is conceded; in this case, the shapes and dimensions of the product, the vibrations, the sharp and...as the load duration factor). The introduction of a newly created material some- times proves unsuccessful due to the fact that, though meeting all...structural nonuniformity of real solids on the mechanism of the development of deformation in them and on their mechanical properties*; (d) the influence of

  18. The Future of Military Graduate Medical Education

    DTIC Science & Technology

    1992-01-08

    Army alone is the country’s largest comprehensive Health Maintenance Organization(HMO). Over the past 45 years, this work force, balancing the competing...that have to be balanced to protect national priorities. As always, costs and budgets will play a major role in determining what is maintained and...a slightly different way. For instance, the Navy generally requires all its medical officers to do some general medical officer work before going on

  19. Risk Propensity and Health Risk Behaviors in U.S. Army Soldiers with and without Psychological Disturbances across the Deployment Cycle

    DTIC Science & Technology

    2012-02-09

    screening instruments, participants were categorized with respect to PTSD and probable TBI. Results suggest that Soldiers engage in more alcohol use and...a longitudinal study will provide stronger evidence to our understanding of the relationships between deployment and adverse health outcomes...and alcohol use, and cost-benefit analysis tasks. The results of this study showed that cognitive regulation was predictive of rational decision

  20. (YIP-09) Improving Synthesis and Recognition of Crowded Scenes using Statistical Models of Group Behavior

    DTIC Science & Technology

    2013-05-01

    prisoner’s dilemma. In Proceedings of Florida Artifical Intelligence Research Society, pages 2–7, Day- tona Beach, FL, May 2010. [6] M. Maghami* and...A. Shah*, P. Bell*, and G. Sukthankar. A destination recommendation system for virtual worlds. In Proceedings of Florida Artifical Intelligence ...question convey? Leveraging help-seeking behavior for improved modeling in a simulation- based intelligent tutor. In Proceedings of SpringSim Military

  1. Market Survey and Analysis in Support of ASAS Computer-Based Training System Design

    DTIC Science & Technology

    1988-11-01

    development nf a recommended strategy for incorporating CBT in the ASAS/ENSCE training system. Approach - In order to establish the state of the art and...a training system which will meet ASAS training requirements. Eleven subsystems are described in terms of their functional input to the overall...keyboard and displays used in actual operation are also used in training, maximizing the transfer effect from practice situations to actual system

  2. Commerce Raiding: Historical Case Studies, 1755-2009

    DTIC Science & Technology

    2013-10-01

    Ariel proceed under bond.26 On 23 December, Alabama met Agrippina at the Arcas Islands off Yucatan and spent a week there taking on supplies and...as the population on the home islands. In particular, the U.S. unrestricted campaign dra- matically reduced the nutritional intake of most Japanese...See Jeune École Yucatan 80 Yusuf, Abdullahi 260, 262–63 Z Z, Operation 182 Zanzibar 128 Zeebrugge 140 Zhili Province 105, 108 The Newport

  3. Joint Information Environment: DOD Needs to Strengthen Governance and Management

    DTIC Science & Technology

    2016-10-25

    while JIE should not result in a net increase in required manpower , the types of skill sets and collocation of those skill sets into regional and...As a result , DOD risks having a deficient security posture and not being able to ensure that it will have the appropriate workforce knowledge and...initiative to consolidate IT infrastructure to achieve savings in acquisition, sustainment, and manpower costs and improve the department’s ability

  4. Natural Gas Propulsion Options for Short Sea Shipping Routes

    DTIC Science & Technology

    2010-08-01

    that are involved with gas and the relevant systems, along with personal protection issues that come into effect when handling both compressed and...a compressed air system for engine starting, which is stored in compressed air storage cylinders . The system leads compressed air through a valve...directly into the cylinder heads at 30bar to begin the rotation of the engine. After this rotation occurs, the engine is supplied with diesel fuel

  5. Faked headaches becoming real.

    PubMed

    Haan, Joost

    2013-06-01

    In the gangster movie White Heat, the main character, Cody (played by James Cagney), suffers from 2 headache attacks. Here, I analyze these attacks by using the International Headache Society criteria, but an unequivocal diagnosis is not possible. Nevertheless, the attacks play an important role in the narrative and--as representation of something between "real" (mimesis) and not real--provide a ground for reflection on how to think of headache in general. © 2013 American Headache Society.

  6. An Investigation of the Pareto Distribution as a Model for High Grazing Angle Clutter

    DTIC Science & Technology

    2011-03-01

    radar detection schemes under controlled conditions. Complicated clutter models result in mathematical difficulties in the determination of optimal and...a population [7]. It has been used in the modelling of actuarial data; an example is in excess of loss quotations in insurance [8]. Its usefulness as...UNCLASSIFIED modified Bessel functions, making it difficult to employ in radar detection schemes. The Pareto Distribution is amenable to mathematical

  7. Comprehensive Nuclear-Test-Ban Treaty: Updated ’Safeguards’ and Net Assessments

    DTIC Science & Technology

    2009-06-03

    measures that this nation can take unilaterally within the treaty to protect its nuclear security. To compensate for “disadvantages and risk” they...and strategic forces, and could be augmented with implementation measures . While Safeguards may be part of a future CTBT debate, both supporters and...A second path involves efforts to alter the net assessment through measures intended to mitigate perceived risks of the treaty. This path has been

  8. Natural Gas as an Instrument of Russian State Power (Letort Paper)

    DTIC Science & Technology

    2011-10-01

    effects the price increase had on the Ukrainian industry as a whole; and does not account for the costs to the Ukrainian economy of the 2006 and...a political consideration); and the differential cost of sanctions among the senders (largely an economic factor). First, allies hardly ever agree...sanctions is extremely hard to realize. 5 Second, the cost of imposing sanctions is sim- ply greater for some sender states than the potential

  9. Buying ’Green’: Implementation of Environmentally-Sound Purchasing Requirements in Department of Defense Procurements

    DTIC Science & Technology

    1993-09-30

    contract for the removal, transportation and disposal of miscellaneous hazardous items located at installations in and around the Naval Air Station at...tary weapons designed for combat use, certain National keronautics and Space Administration (NASA) rockets, and Covernment experimental machinery and...as such terms are defined in Section 101 of the Federal Aviation Act of 1958; or (ii)(a) Any military weapons or equipment which are designed for

  10. Fracture Characteristics of Structural Steels: Reference Manual

    DTIC Science & Technology

    1979-04-01

    materials were fractured undcr tensile, fatigue, and impact loading con- ditions. The effects of hydrogen embrittlement on the steels ’ behavior when...years after paint failure. The composition and the heat treatment of 4160 steel results in a steel extremely susceptible to stress corrosion cracking and...A35 Fracture Surface of Tensile Specimen No. 3 322 22 IL TABLES Number Page 1 Chemical Composition of Steels and Weld Metal 32 2 Welding Parameters 33

  11. Command detector SNR estimator and lock status monitor circuitry

    NASA Technical Reports Server (NTRS)

    Emerson, R. F.

    1976-01-01

    A breadboard of the command detector signal-to-noise-ratio estimator and lock status monitor was built on a wire-wrap card. The breadboard was integrated with the standard command detector, and its performance was measured. The design, design constraints, and construction of the breadboard are described. The performance is shown to agree with the theoretical model.

  12. Cherenkov neutron detector for fusion reaction and runaway electron diagnostics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cheon, MunSeong, E-mail: munseong@nfri.re.kr; Kim, Junghee

    2015-08-15

    A Cherenkov-type neutron detector was newly developed and neutron measurement experiments were performed at Korea Superconducting Tokamak Advanced Research. It was shown that the Cherenkov neutron detector can monitor the time-resolved neutron flux from deuterium-fueled fusion plasmas. Owing to the high temporal resolution of the detector, fast behaviors of runaway electrons, such as the neutron spikes, could be observed clearly. It is expected that the Cherenkov neutron detector could be utilized to provide useful information on runaway electrons as well as fusion reaction rate in fusion plasmas.

  13. Optics Research: 1975:2

    DTIC Science & Technology

    1975-12-31

    9. The detectors were numbered as shown. Detector 2 of the HgCdTe array was turned off due to noise considerations. The array traces show an...The probe beam diagnostics were composed of a large area Au:Ge detector to measure the total probe beam transmission, and a five-element HgCdTe array...laser. ...^-J-..:..^il iitiiinnii" --- "-’ ^Ul.ü^^j .. r ■:, >iUj<&k focal spot size. Other shots show larger signals on the outside detectors

  14. Gamma-ray Irradiation Effects on InAs/GaSb-based nBn IR Detector

    DTIC Science & Technology

    2011-01-01

    very low noise performance. When properly passivated, conventional mercury cadmium telluride ( MCT )?based infrared detectors have been shown to...Gamma-ray Irradiation Effects on InAs/GaSb-based nBn IR Detector Vincent M. Cowan*1, Christian P. Morath1, Seth M. Swift1, Stephen Myers2...2Center for High Technology Materials, University of New Mexico, Albuquerque, NM 87106, USA ABSTRACT IR detectors operated in a space environment are

  15. Modeling of clover detector in addback mode

    NASA Astrophysics Data System (ADS)

    Kshetri, R.

    2012-07-01

    Based on absorption and scattering of gamma-rays, a formalism has been presented for modeling the clover germanium detector in addback mode and to predict its response for high energy γ-rays. In the present formalism, the operation of a bare clover detector could be described in terms of three quantities only. Considering an additional parameter, the formalism could be extended for suppressed clover. Using experimental data on relative single crystal efficiency and addback factor as input, the peak-to-total ratio has been calculated for three energies (Eγ = 3.401, 5.324 and 10.430 MeV) where direct measurement of peak-to-total ratio is impossible due to absence of a radioactive source having single monoenergetic gamma-ray of that energy. The experimental validation and consistency of the formalism have been shown considering data for TIGRESS clover detector. In a recent work (R. Kshetri, JINST 2012 7 P04008), we showed that for a given γ-ray energy, the formalism could be used to predict the peak-to-total ratio as a function of number of detector modules. In the present paper, we have shown that for a given composite detector (clover detector is considered here), the formalism could be used to predict the peak-to-total ratio as a function of γ-ray energy.

  16. The utilisation of two detectors for the determination of water in honey using headspace gas chromatography.

    PubMed

    Frink, Lillian A; Armstrong, Daniel W

    2016-08-15

    A headspace gas chromatography (HSGC) method was developed for the determination of water content in honey. This method was shown to work with five different honey varieties which had a range of water from 14-16%. It also utilised two different detectors, the thermal conductivity detector (TCD) and the barrier discharge ionisation detector (BID). This method needs no heating pretreatment step as in the current leading method, (i.e. the measurement of refractive index). The solvent-free procedure negates the possibility of solvent-compound interactions as well as solubility limitations, as is common with Karl Fischer titrations. It was also apparent that the classic loss on drying method consistently and substantially produced results that were lower than the correct values. This approach is shown to be rapid, with an analysis time of 4 min when using the TCD detector and under 3 min when utilising the BID detector. HSGC is feasible for the determination of water due to the new PEG-linked geminal dicationic ionic-liquid-coated GC capillary column. In addition it provides accurate and precise determinations of the water content in honey. When using the sensitive BID detector, other trace volatile compounds are observed as well. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Generation-recombination noise in extrinsic photoconductive detectors

    NASA Technical Reports Server (NTRS)

    Brukilacchio, T. J.; Skeldon, M. D.; Boyd, R. W.

    1984-01-01

    A theory of generation-recombination noise is presented and applied to the analysis of the performance limitations of extrinsic photoconductive detectors. The theory takes account both of the photoinduced generation of carriers and of thermal generation that is due to the finite temperature of the detector. Explicit formulas are derived that relate the detector response time, responsivity, and noise equivalent power to the material properties of the photoconductor (such as the presence of compensating impurities) and to the detector's operating conditions, such as its temperature and the presence of background radiation. The detector's performance is shown to degrade at high background levels because of saturation effects.

  18. Radiation Assessment Detector for Mars Science Laboratory

    NASA Image and Video Library

    2010-11-09

    The Radiation Assessment Detector, shown prior to its September 2010 installation onto NASA Mars rover Curiosity, will aid future human missions to Mars by providing information about the radiation environment on Mars and on the way to Mars.

  19. Computational Methods for Complex Flowfields

    DTIC Science & Technology

    1989-07-05

    This treatment is easily every ohrgi ie(i.9.Telclyfns el a extedd fo a-D knds pinerfces. Ths reuatemen rost e belong to either an unembedded or an...leading edge region is embedded in both directions. The downstream region between the two shear layers remains unembedded . Comparison of the grid and...A2 are unembedded coarse cells with vertical dimensions twice those of cells As, A4. It is clear that an evaluation for example, of the viscous

  20. Evaluation of the Safety and Efficacy of the FAAH Inhibitor URB597

    DTIC Science & Technology

    2016-01-01

    contracts!and!business!was!initiated.!As! requested!by!USAMRAA!the!1.5kg!of!URB597!that!had!produced!by!vendor!STA! Pharmaceutical! Hong ! Kong !Limited...Pharmaceutical! Hong ! Kong !Limited,!and!New!York! University!School!of!Medicine,!a!contract!was!executed!on!September!26,!2014,!and!a! Purchase!Order!was!issued...instructed by USAMRMC, August 2015. 15.2SUBJECT2TERMS post traumatic stress disorder, OEF/OIF clinical trial, FAAH, CB1 receptor, brain imaging

  1. Operational Cybersecurity Risks and Their Effect on Adoption of Additive Manufacturing in the Naval Domain

    DTIC Science & Technology

    2017-12-01

    material and limiting overproduction issues experienced in traditional manufacturing . Figure 2 shows how AM may also speed productivity by reducing time...schematic from a file and have a computer printer create that item in real life layer by layer 30. Geek method of manufacture at low rate of production and...a three dimensional form. 46. Additive production technique utilizing material extruded onto a bed, usually in 3-axes. 47. Additive manufacturing

  2. Providing Technical Expertise for Effective Contract Management

    DTIC Science & Technology

    2011-04-12

    back to both the finance leg and the contracting leg . In order to avoid a conflict of interest or give the impression of 4 any improprieties...each leg of this triad is separate. It is this reason and those already mentioned that the COR is the responsibility of the requiring activity and...A. Fulghum, DoD Logistician Optimistic About Afghanistan (Aviation Week’s DTI , January 27, 2010) as reported on military.com, accessed on 15 February

  3. A Pulse Code Modulated Fiber Optic Link Design for Quinault Under-Water Tracking Range.

    DTIC Science & Technology

    1980-09-01

    invented and patented a light-wave communications device, the Photophone . The light beam was acoustically modulated, transmitted through the atmosphere and...a load resistor or feedback resistor. This voltage can be cal- culated by multiplying the received power, the respcnsiv ity and the effective load...frequency is not real critical since the clock, in effect , is synchronized after every eight bits by the timing pulse. The more interesting part of the

  4. Microbiologically Influenced Corrosion in Copper and Nickel Seawater Piping Systems

    DTIC Science & Technology

    1990-09-01

    Influenced Tipton, D. G. and Kain, R. M. 1980. Effect of temperature onCorosiope in Nuclear Power Plants atudy a Mical Gnuide the resistance to pitting of...Monel alloy 400 in seawater. In:Corrosion in Nuclear Power Plants anda Practical ie fr Proceedings of Corrosion 󈨔. Chicago, Illinois: National...Sons Ltd. 441 pp. Quimica . Verink, E.D. and Pourbaix, M. 1971. Use of electrochemical Pope, D. H., Duquette, D. J., Johannes, A. H., and Wayner

  5. Friction in U.S. Foreign Policy: Cultural Difficulties with the World

    DTIC Science & Technology

    2006-03-15

    the intrusive and high-handed behaviour of the West. We see examples of this kind of attitude all around the world from Latin America to Africa and...a distracting rhetoric to conceal the root causes of Latin American poverty—a culture of outright corruption and exploitation of the people and land...and organized crime are now distinct from each other, rising anti-Americanism could cause Latin American organized crime figures to be more willing

  6. Electro-Optic Modulator.

    DTIC Science & Technology

    An electro - optic modulator is used to modulate coherent light beams by the application of an electric potential. It combines a Fabry-Perot etalon and...a diffraction grating in a single unit. An etalon is constructed with an electro - optic material between reflecting surfaces. A voltage applied...between alternate, spaced-apart electrodes of a metal grid attached to one reflecting surface induces a diffraction grating in the electro optic material. Light entering the etalon is diffracted, reflected and efficiently coupled out.

  7. 26 CFR 301.9100-7T - Time and manner of making certain elections under the Tax Reform Act of 1986.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...(p)(1) of the Act. [See paragraph (a)(2)(vii) and(a)(3)(x) of this section.] 1882(c) 3121(w)(2... absence from the United States during the election year that are deemed to be days of presence. (x... the election described in H.R. Rep. No. 99-841 at II-320, 811(a) 453C(b)(2)(B)(i), 453C(e)(4) 905(a...

  8. 26 CFR 301.9100-7T - Time and manner of making certain elections under the Tax Reform Act of 1986.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...(p)(1) of the Act. [See paragraph (a)(2)(vii) and(a)(3)(x) of this section.] 1882(c) 3121(w)(2... absence from the United States during the election year that are deemed to be days of presence. (x... the election described in H.R. Rep. No. 99-841 at II-320, 811(a) 453C(b)(2)(B)(i), 453C(e)(4) 905(a...

  9. 26 CFR 301.9100-7T - Time and manner of making certain elections under the Tax Reform Act of 1986.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...(p)(1) of the Act. [See paragraph (a)(2)(vii) and(a)(3)(x) of this section.] 1882(c) 3121(w)(2... absence from the United States during the election year that are deemed to be days of presence. (x... the election described in H.R. Rep. No. 99-841 at II-320, 811(a) 453C(b)(2)(B)(i), 453C(e)(4) 905(a...

  10. Quality Control Review of the Defense Intelligence Agency, Office of Inspector General, Audit Division

    DTIC Science & Technology

    2015-02-26

    mission is to support the overall DIA OIG role of providing oversight of and reporting upon matters, which pertain to the performance of mission and...as discussed throughout this report. In the two IPERA audits, the DIA OIG Audit Division auditors found that DIA did not comply with the IPERA. For...Independence Not Followed For two of the three audits reviewed, the auditors did not follow the GAGAS conceptual framework for independence. GAGAS

  11. Rethinking Third-Party Intervention into Insurgencies: The Logic of Commitment

    DTIC Science & Technology

    2010-04-14

    Isaiah Wilson III, “Rage Against the Machines: Explaining Outcomes in Counterinsurgency Wars,” International Organization 63, no. 1 (2009): 67-106 and...a chosen goal and it drives people to act consistently because it would be morally wrong, practically inexpedient, or both to do otherwise.49 Thomas ...prospects for future activity by the intervener. 50 Thomas C. Schelling, Arms and Influence (New Haven, CT: Yale University Press, 2009), 49. 51 Ibid., 65-6

  12. Investigations of Reactive Processes at Temperatures Relevant to the Hypersonic Flight Regime

    DTIC Science & Technology

    2014-10-31

    molecule is constructed based on high- level ab-initio calculations and interpolated using the reproducible kernel Hilbert space (RKHS) method and...a potential energy surface (PES) for the ground state of the NO2 molecule is constructed based on high- level ab initio calculations and interpolated...between O(3P) and NO(2Π) at higher temperatures relevant to the hypersonic flight regime of reentering space- crafts. At a more fundamental level , we

  13. Attacking the Lion: A Study of Cohesion in Naval Special Warfare Operational Units

    DTIC Science & Technology

    2011-06-01

    of Existential Courage.‖ Journal of Humanistic Psychology 44, no. 3 (Summer 2004): 279–298. ———. ―Relevance of Hardiness Assessment and Training to...stealth, teamwork, and violence of action to survive and succeed in missions against larger opponents. Developing bonds of trust between individuals and...a force that conducts kinetic action missions with an emphasis on speed, surprise, and violence of action. For the most part, this mentality

  14. United States Air Force Graduate Student Research Program. Program Technical rept. Volume 3

    DTIC Science & Technology

    1988-12-01

    placing scalp electrodes in a bipolar arrangement. An additional problem we faced in the F4 study was time- loc ::ing the ERP to the eliciting...and Leo Jehl of OEHL for their help with halide and metal analysis that was invalubae to this project. John Barnaby, Will Robinson, Chris Ritter, and...a patient teacher of statistical methods. Dr Eric D. Grassman and Dr Leo Spaccavento explained many technical cardiological points and were generally

  15. Calibration of time of flight detectors using laser-driven neutron source

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mirfayzi, S. R.; Kar, S., E-mail: s.kar@qub.ac.uk; Ahmed, H.

    2015-07-15

    Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

  16. Calibration of time of flight detectors using laser-driven neutron source.

    PubMed

    Mirfayzi, S R; Kar, S; Ahmed, H; Krygier, A G; Green, A; Alejo, A; Clarke, R; Freeman, R R; Fuchs, J; Jung, D; Kleinschmidt, A; Morrison, J T; Najmudin, Z; Nakamura, H; Norreys, P; Oliver, M; Roth, M; Vassura, L; Zepf, M; Borghesi, M

    2015-07-01

    Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

  17. Calibration of time of flight detectors using laser-driven neutron source

    NASA Astrophysics Data System (ADS)

    Mirfayzi, S. R.; Kar, S.; Ahmed, H.; Krygier, A. G.; Green, A.; Alejo, A.; Clarke, R.; Freeman, R. R.; Fuchs, J.; Jung, D.; Kleinschmidt, A.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.

    2015-07-01

    Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

  18. Effect of Detector Dead Time on the Performance of Optical Direct-Detection Communication Links

    NASA Technical Reports Server (NTRS)

    Chen, C.-C.

    1988-01-01

    Avalanche photodiodes (APDs) operating in the Geiger mode can provide a significantly improved single-photon detect ion sensitivity over conventional photodiodes. However, the quenching circuit required to remove the excess charge carriers after each photon event can introduce an undesirable dead time into the detection process. The effect of this detector dead time on the performance of a binary pulse-position-modulted (PPM) channel is studied by analyzing the error probability. It is shown that, when back- ground noise is negligible, the performance of the detector with dead time is similar to that o f a quantum-limited receiver. For systems with increasing background intensities, the error rate of the receiver starts to degrade rapidly with increasing dead time. The power penalty due to detector dead time is also evaluated and shown to depend critically on background intensity as well as dead time. Given the expected background strength in an optical channel, therefore, a constraint must be placed on the bandwidth of the receiver to limit the amount of power penalty due to detector dead time.

  19. Effect of detector dead time on the performance of optical direct-detection communication links

    NASA Astrophysics Data System (ADS)

    Chen, C.-C.

    1988-05-01

    Avalanche photodiodes (APDs) operating in the Geiger mode can provide a significantly improved single-photon detection sensitivity over conventional photodiodes. However, the quenching circuit required to remove the excess charge carriers after each photon event can introduce an undesirable dead time into the detection process. The effect of this detector dead time on the performance of a binary pulse-position-modulated (PPM) channel is studied by analyzing the error probability. It is shown that, when background noise is negligible, the performance of the detector with dead time is similar to that of a quantum-limited receiver. For systems with increasing background intensities, the error rate of the receiver starts to degrade rapidly with increasing dead time. The power penalty due to detector dead time is also evaluated and shown to depend critically on badkground intensity as well as dead time. Given the expected background strength in an optical channel, therefore, a constraint must be placed on the bandwidth of the receiver to limit the amount of power penalty due to detector dead time.

  20. Resistive-strips micromegas detectors with two-dimensional readout

    NASA Astrophysics Data System (ADS)

    Byszewski, M.; Wotschack, J.

    2012-02-01

    Micromegas detectors show very good performance for charged particle tracking in high rate environments as for example at the LHC. It is shown that two coordinates can be extracted from a single gas gap in these detectors. Several micromegas chambers with spark protection by resistive strips and two-dimensional readout have been tested in the context of the R&D work for the ATLAS Muon System upgrade.

  1. A novel small-angle neutron scattering detector geometry

    PubMed Central

    Kanaki, Kalliopi; Jackson, Andrew; Hall-Wilton, Richard; Piscitelli, Francesco; Kirstein, Oliver; Andersen, Ken H.

    2013-01-01

    A novel 2π detector geometry for small-angle neutron scattering (SANS) applications is presented and its theoretical performance evaluated. Such a novel geometry is ideally suited for a SANS instrument at the European Spallation Source (ESS). Motivated by the low availability and high price of 3He, the new concept utilizes gaseous detectors with 10B as the neutron converter. The shape of the detector is inspired by an optimization process based on the properties of the conversion material. Advantages over the detector geometry traditionally used on SANS instruments are discussed. The angular and time resolutions of the proposed detector concept are shown to satisfy the requirements of the particular SANS instrument. PMID:24046504

  2. The 12th International Conference on Computer Safety, Reliability and Security

    DTIC Science & Technology

    1993-10-29

    then used [10]. The adequacy of the proposed methodology is shown through the design and the validation of a simple control system: a train set example...satisfying the safety condition. 4 Conclusions In this paper we have presented a methodology which can be used for the design of safety-critical systems...has a Burner but no Detector (or the Detector is permanently non -active). The PA: G1 for this design is shown in Fig 3a. The probability matrices are

  3. Operational performance characteristics of the WISH detector array on the ISIS spallation neutron source

    NASA Astrophysics Data System (ADS)

    Duxbury, D.; Khalyavin, D.; Manuel, P.; Raspino, D.; Rhodes, N.; Schooneveld, E.; Spill, E.

    2014-12-01

    The performance of the position sensitive neutron detector array of the WISH diffractometer is discussed. WISH (Wide angle In a Single Histogram) is one of the seven instruments currently available for users on the second target station (TS2) of the ISIS spallation neutron source, and is used mainly for magnetic studies of materials. WISH is instrumented with an array of 10 detector panels, covering an angular range of 320o, orientated in two semi-cylindrical annuli around a central sample position at a radius of 2.2m. In total the 10 detector panels are composed of 1520 3He based position sensitive detector tubes. Each tube has an active length of one metre, a diameter of 8mm and is filled with 3He at 15 bar. The specification for the WISH detectors included a neutron detection efficiency of 50% at a neutron wavelength of 1Å with good gamma rejection. A position resolution better than 8 mm FWHM along the length of the tubes was also required which has been met experimentally. Results obtained from the detector arrays showing pulse height and positional information both prior to and post installation are shown. The first 5 of the 10 detector panels have been operational since 2009, and comparable diffraction data from powder and single crystal samples taken from the remaining 5 panels (installation completed in 2013) shows that we have a detector array with a highly stable performance which is easily assembled and maintained. Finally some real user data is shown, highlighting the excellent quality of data attainable with this instrument.

  4. Plutonium Bioassay Testing of U.S. Atmospheric Nuclear Test Participants and U.S. Occupation Forces of Hiroshima and Nagasaki, Japan

    DTIC Science & Technology

    2015-10-30

    with nuclear weapons testing or plutonium work. The results for the 100 atomic veterans were compared to those of the unexposed population, and...as a marker for significant internal intakes of other associated radionuclides in nuclear weapons debris due to its low natural background. However...isotope in weapons grade plutonium, is important from a health perspective, its presence within a given urine sample being analyzed by FTA can only

  5. Army Logistician. Volume 33, Issue 5, September-October 2001

    DTIC Science & Technology

    2001-10-01

    vehicle, and a first- strike ration that pro- vides an eat-out-of-hand capability for use during the initial stages of deployment, providing increased carbo...battle. On 9 September, a portion of the German 8th Army, striking though the Masurian Lakes region, severed the already anemic Rus- sian supply and...as the ability to “ strike the enemy at a time or place or in a manner for which he is unprepared.” Surprise can decisively shift the bal- ance of

  6. Affective Intensity and its Effects

    DTIC Science & Technology

    2010-11-29

    pp174-193. Matsumoto D, Wilson J (2008). Culture , emotion, and motivation. In R. Sorrentino and S. Yamaguchi (eds.), Handbook of Motivation and...a skill which enables successful task completion. 15. SUBJECT TERMS Behavioural Science, Psychology 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...integral aspect of a person’s response to increased task  demands. Traditionally,  psychological  models have been based on verbal descriptions of the

  7. U.S. Army Corps of Engineers Manpower Information System: An Integrated Approach to Manpower Management

    DTIC Science & Technology

    1994-04-01

    engineering and con- struction management services for both military and civil works programs. In FY93, the cost of those programs exceeded $10 billion and...A related issue was to explore the USACE costs , benefits, and barriers to implementing a single Class VI system software package for both the military...provide information in useful ways, track utilization information, I A Class HI system is defined in AR 25-3. It is a system whose total program costs are

  8. Detailed Project Report on Emergency Shoreline Protection, Section 14 Boggy Bayou, Valparaiso, Florida

    DTIC Science & Technology

    1989-08-01

    adjacent to Bayshore Drive. Along the shoreline within the current study area, (see Plate 4) private residents have constructed three wood piers and...a wood boat shed. The construction of piers and boat sheds is no longer permitted by the city. However, the piers and boat shed were allowed to remain...located in the project site. Removal and 6 replacement of the 3 wood piers and the boat shed and the steps that lead to them will be a responsibility of

  9. Observations of Near-Bottom Flow in a Wave-Dominated Nearshore Environment.

    DTIC Science & Technology

    1994-02-01

    E 0 0 0 ~- X : (- 1.. pI m~ ffm ~o .pcr onf> ..... X • -- E X/• x,. "£ "*.. . .. . 0o 0 0 a c c ,(s0wO) (S/PH w) (SlUwo) . 7109 I 3 I Mean of LDV...1 I 8250 ASM X,ANDA #&HBF :REM 0000 OXXX ACCA 8260 ASM X,ANDB #&HBF :REM 0000 1XXX ACCB 8270 ASM X,STAB &H17 :REM /CS=0 3 8280 ASM X,STAA &H17 :REM

  10. An Investigation Concerning the Potential for use of Polylactic/Polyglycolic Acid Confluent Sheets in the Treatment of Osseous Defects,

    DTIC Science & Technology

    1992-01-01

    Periodontics and Oral Biology, University of Missouri-Kansas City, School of Dentistry, Kansas City, MO 64108. •* Departments of Hospital Dentistry and...as a matrix for osseous grafting, for the occlusion of large bony defects, for soft tissue contour defects, and also as a bone plating system. All of...Hunsck EE: Tissue reaction to biodegradable polylactide acid suture. Oral Surg, 31:134, 1971. 5. Kulkurni RK, Pani KC, Neuman C, et al.: Polylactic acid

  11. The Average Change in Facial Height Following Bilateral Sagittal Split Osteotomy Advancement in Class II Patients

    DTIC Science & Technology

    2017-04-21

    The S9 CRD/Publications and Presentations Section will route the request form to clinical investigations. 502 ISG/JAC ( Ethics Review) and Public...information. 11 . The Joint Ethics Regulation (JER) DoD S500.07-R. Standards of Conduct. provides standards of ethical conduct for all DoD personnel and...a legal ethics review to address any potential conflicts related to DoD personnel participating in non-DoD sponsored conferences, professional

  12. Integrated Spatial Models of Non Native Plant Invasion, Fire Risk, and Wildlife Habitat to Support Conservation of Military and Adjacent Lands in the Arid Southwest

    DTIC Science & Technology

    2015-12-01

    FINAL REPORT Integrated spatial models of non-native plant invasion, fire risk, and wildlife habitat to support conservation of military and...as reflecting the official policy or position of the Department of Defense. Reference herein to any specific commercial product, process, or service...2. REPORT TYPE Final 3. DATES COVERED (From - To) 26/4/2010 – 25/10/2015 4. TITLE AND SUBTITLE Integrated Spatial Models of Non-Native Plant

  13. Archeological Investigations in Cochiti Reservoir, New Mexico. Volume 3. 1976-1977 Field Seasons.

    DTIC Science & Technology

    1979-01-01

    or methods are in a constant state of flux, and will undoubtedly continue so. The present In 1959, Baumhoff and Heizer suggested that the sys- paper...marrow extraction and when as estimates rather than counts were insect bodies and rendering bone grease. parts (10-25%), cocoons/larvae/eggs (1-10%), and...A yielded rendering bone grease or making soup. The association of 40 burned bone fragments. A 500 ml sample from grid the unidentified fragments and

  14. Effects of Transient Power Extraction on an Integrated Hardware-in-the-Loop Aircraft/Propulsion/Power System

    DTIC Science & Technology

    2008-11-01

    Simulations of an engine and its Full Authority Digital Engine Control ( FADEC ), along with a 6 degree-of-freedom (6DoF) airframe dynamics model and...as needed. In its current configuration, the generic turbine engine model’s FADEC is included in the same simulation and runs primarily on 2 a...back to the engine. As mentioned previously, the FADEC and engine are combined into one simulation and are collectively referred to as “the engine

  15. Quantal Response: Estimation and Inference

    DTIC Science & Technology

    2014-09-01

    considered. The CI-based test is just another way of looking at the Wald test. A small-sample simulation illustrates aberrant behavior of the Wald/CI...asymptotic power computation (Eq. 36) exhibits this behavior but not to such an extent as the simulated small-sample power. Sample size is n = 11 and...as |m1−m0| increases, but the power of the Wald test actually decreases for large |m1−m0| and eventually π → α . This type of behavior was reported as

  16. Environmental Inventory Report. East St. Louis and Vicinity, Cahokia Canal Drainage Area, Madison and St. Clair Counties, Illinois. Volume 4.

    DTIC Science & Technology

    1981-05-01

    successive waves of Indian, French , British, and Americans to what is now Madison and St. Clair Counties. This section of the Cahokia Canal...by the French . In 1673 the Jesuit missionary, Marquette, anda fur-trader, Jol iet, descended the Mississippi by canoe to a point somewhere south of...it. French Settlements The French were also the first to attempt permanent settlements in Illinois. In 1675, at a site near present day Utica in La

  17. Global 󈧌, U.S. Navy Title X War Game: Implementing the Maritime Strategy, 4-8 August 2008. Game Report

    DTIC Science & Technology

    2009-03-01

    flying in formation over the beach as an aggressive or hostile act. Similarly, for political reasons the U.S. may need to allow the host nation to put a...levels will result in migration flows and could cause instability, especially in smaller, coastal states. Aging populations, pollution -related and...a broad spectrum of experience from the DoD, U.S. Government, NGOs, academia, and representatives from Argentina, Brazil, Chile, Columbia, and Peru

  18. From a single encapsulated detector to the spectrometer for INTEGRAL satellite: predicting the peak-to-total ratio at high γ-energies

    NASA Astrophysics Data System (ADS)

    Kshetri, R.

    2012-12-01

    In two recent papers (R. Kshetri, JINST 2012 7 P04008; ibid., P07006), a probabilistic formalism was introduced to predict the response of encapsulated type composite germanium detectors like the SPI (spectrometer for INTEGRAL satellite). Predictions for the peak-to-total and peak-to-background ratios are given at 1.3 MeV for the addback mode of operation. The application of the formalism to clover germanium detector is discussed in two separate papers (R. Kshetri, JINST 2012 7 P07008; ibid., P08015). Using the basic approach developed in those papers, for the first time we present a procedure for calculating the peak-to-total ratio of the cluster detector for γ-energies up to 8 MeV. Results are shown for both bare and suppressed detectors as well as for the single crystal and addback modes of operation. We have considered the experimental data of (i) peak-to-total ratio at 1.3 MeV, and (ii) single detector efficiency and addback factor for other energies up to 8 MeV. Using this data, an approximate method of calculating the peak-to-total ratio of other composite detectors, is shown. Experimental validation of our approach (for energies up to 8 MeV) has been confirmed considering the data of the SPI spectrometer. We have discussed about comparisons between various modes of operation and suppression cases. The present paper is the fifth in the series of papers on composite germanium detectors and for the first time discusses about the change in fold distribution and peak-to-total ratio for sophisticated detectors consisting of several modules of miniball, cluster and SPI detectors. Our work could provide a guidance in designing new composite detectors and in performing experimental studies with the existing detectors for high energy gamma-rays.

  19. Direct conversion semiconductor detectors in positron emission tomography

    NASA Astrophysics Data System (ADS)

    Cates, Joshua W.; Gu, Yi; Levin, Craig S.

    2015-05-01

    Semiconductor detectors are playing an increasing role in ongoing research to improve image resolution, contrast, and quantitative accuracy in preclinical applications of positron emission tomography (PET). These detectors serve as a medium for direct detection of annihilation photons. Early clinical translation of this technology has shown improvements in image quality and tumor delineation for head and neck cancers, relative to conventional scintillator-based systems. After a brief outline of the basics of PET imaging and the physical detection mechanisms for semiconductor detectors, an overview of ongoing detector development work is presented. The capabilities of semiconductor-based PET systems and the current state of these devices are discussed.

  20. NEMO: Status of the Project

    NASA Astrophysics Data System (ADS)

    Migneco, E.; Aiello, S.; Amato, E.; Ambriola, M.; Ameli, F.; Andronico, G.; Anghinolfi, M.; Battaglieri, M.; Bellotti, R.; Bersani, A.; Boldrin, A.; Bonori, M.; Cafagna, F.; Capone, A.; Caponnetto, L.; Chiarusi, T.; Circella, M.; Cocimano, R.; Coniglione, R.; Cordelli, M.; Costa, M.; Cuneo, S.; D'Amico, A.; D'Amico, V.; De Marzo, C.; De Vita, R.; Distefano, C.; Gabrielli, A.; Gandolfi, E.; Grimaldi, A.; Habel, R.; Italiano, A.; Leonardi, M.; Lo Nigro, L.; Lo Presti, D.; Margiotta, A.; Martini, A.; Masetti, M.; Masullo, R.; Montaruli, T.; Mosetti, R.; Musumeci, M.; Nicolau, C. A.; Occhipinti, R.; Papaleo, R.; Petta, C.; Piattelli, P.; Raia, G.; Randazzo, N.; Reito, S.; Ricco, G.; Riccobene, G.; Ripani, M.; Romita, M.; Rovelli, A.; Ruppi, M.; Russo, G. V.; Russo, M.; Sapienza, P.; Schuller, J. P.; Sedita, M.; Sokalski, I.; Spurio, M.; Taiuti, M.; Trasatti, L.; Ursella, L.; Valente, V.; Vicini, P.; Zanarini, G.

    2004-11-01

    The activities towards the realisation of a km3 Cherenkov neutrino detector, carried out by the NEMO Collaboration are described. Long term exploration of a 3500 m deep site close to the Sicilian coast has shown that it is optimal for the installation of the detector. A complete feasibility study, that has considered all the components of the detector as well as its deployment, has been carried out demonstrating that technological solutions exist for the realization of an underwater km3 detector. The realization of a technological demonstrator (the NEMO Phase 1 project) is under way.

  1. X-ray fluorescence analysis of alloy and stainless steels using a mercuric iodide detector

    NASA Technical Reports Server (NTRS)

    Kelliher, Warren C.; Maddox, W. Gene

    1988-01-01

    A mercuric iodide detector was used for the XRF analysis of a number of NBS standard steels, applying a specially developed correction method for interelemental effects. It is shown that, using this method and a good peak-deconvolution technique, the HgI2 detector is capable of achieving resolutions and count rates needed in the XRF anlysis of multielement samples. The freedom from cryogenic cooling and from power supplies necessary for an electrically cooled device makes this detector a very good candidate for a portable instrument.

  2. Study of prototypes of LFoundry active CMOS pixels sensors for the ATLAS detector

    NASA Astrophysics Data System (ADS)

    Vigani, L.; Bortoletto, D.; Ambroz, L.; Plackett, R.; Hemperek, T.; Rymaszewski, P.; Wang, T.; Krueger, H.; Hirono, T.; Caicedo Sierra, I.; Wermes, N.; Barbero, M.; Bhat, S.; Breugnon, P.; Chen, Z.; Godiot, S.; Pangaud, P.; Rozanov, A.

    2018-02-01

    Current high energy particle physics experiments at the LHC use hybrid silicon detectors, in both pixel and strip configurations, for their inner trackers. These detectors have proven to be very reliable and performant. Nevertheless, there is great interest in depleted CMOS silicon detectors, which could achieve a similar performance at lower cost of production. We present recent developments of this technology in the framework of the ATLAS CMOS demonstrator project. In particular, studies of two active sensors from LFoundry, CCPD_LF and LFCPIX, are shown.

  3. Digital pulse-shape analysis with a TRACE early silicon prototype

    NASA Astrophysics Data System (ADS)

    Mengoni, D.; Dueñas, J. A.; Assié, M.; Boiano, C.; John, P. R.; Aliaga, R. J.; Beaumel, D.; Capra, S.; Gadea, A.; Gonzáles, V.; Gottardo, A.; Grassi, L.; Herrero-Bosch, V.; Houdy, T.; Martel, I.; Parkar, V. V.; Perez-Vidal, R.; Pullia, A.; Sanchis, E.; Triossi, A.; Valiente Dobón, J. J.

    2014-11-01

    A highly segmented silicon-pad detector prototype has been tested to explore the performance of the digital pulse shape analysis in the discrimination of the particles reaching the silicon detector. For the first time a 200 μm thin silicon detector, grown using an ordinary floating zone technique, has been shown to exhibit a level discrimination thanks to the fine segmentation. Light-charged particles down to few MeV have been separated, including their punch-through. A coaxial HPGe detector in time coincidence has further confirmed the quality of the particle discrimination.

  4. Advance in multi-hit detection and quantization in atom probe tomography.

    PubMed

    Da Costa, G; Wang, H; Duguay, S; Bostel, A; Blavette, D; Deconihout, B

    2012-12-01

    The preferential retention of high evaporation field chemical species at the sample surface in atom-probe tomography (e.g., boron in silicon or in metallic alloys) leads to correlated field evaporation and pronounced pile-up effects on the detector. The latter severely affects the reliability of concentration measurements of current 3D atom probes leading to an under-estimation of the concentrations of the high-field species. The multi-hit capabilities of the position-sensitive time-resolved detector is shown to play a key role. An innovative method based on Fourier space signal processing of signals supplied by an advance delay-line position-sensitive detector is shown to drastically improve the time resolving power of the detector and consequently its capability to detect multiple events. Results show that up to 30 ions on the same evaporation pulse can be detected and properly positioned. The major impact of this new method on the quantization of chemical composition in materials, particularly in highly-doped Si(B) samples is highlighted.

  5. Accurate electromagnetic modeling of terahertz detectors

    NASA Technical Reports Server (NTRS)

    Focardi, Paolo; McGrath, William R.

    2004-01-01

    Twin slot antennas coupled to superconducting devices have been developed over the years as single pixel detectors in the terahertz (THz) frequency range for space-based and astronomy applications. Used either for mixing or direct detection, they have been object of several investigations, and are currently being developed for several missions funded or co-funded by NASA. Although they have shown promising performance in terms of noise and sensitivity, so far they have usually also shown a considerable disagreement in terms of performance between calculations and measurements, especially when considering center frequency and bandwidth. In this paper we present a thorough and accurate electromagnetic model of complete detector and we compare the results of calculations with measurements. Starting from a model of the embedding circuit, the effect of all the other elements in the detector in the coupled power have been analyzed. An extensive variety of measured and calculated data, as presented in this paper, demonstrates the effectiveness and reliability of the electromagnetic model at frequencies between 600 GHz and 2.5THz.

  6. DAMPE prototype and its beam test results at CERN

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Hu, Yiming; Chang, Jin

    The first Chinese high energy cosmic particle detector(DAMPE) aims to detect electron/gamma at the range between 5GeV and 10TeV in space. A prototype of this detector is made and tested using both cosmic muons and test beam at CERN. Energy and space resolution as well as strong separation power for electron and proton are shown in the results. The detector structure is illustrated as well.

  7. High Resolution PET Imaging Probe for the Detection, Molecular Characterization and Treatment Monitoring of Prostate Cancer

    DTIC Science & Technology

    2012-07-01

    Jitter results from electronic noise and from the fact that the shape of the detector signal used for timing can vary considerably depending on the...photomultiplier technology, several “probe” detectors were developed. It was predicted, and subsequently shown, that probes having good position...high spatial resolution for prostate imaging. Practical proof-of-concept detectors with good depth-of-interactions resolution have been developed and

  8. The Influence of Gantry Geometry on Aliasing and Other Geometry Dependent Errors

    NASA Astrophysics Data System (ADS)

    Joseph, Peter M.

    1980-06-01

    At least three gantry geometries are widely used in medical CT scanners: (1) rotate-translate, (2) rotating detectors, (3) stationary detectors. There are significant geometrical differences between these designs, especially regarding (a) the region of space scanned by any given detector and (b) the sample density of rays which scan the patient. It is imperative to distinguish between "views" and "rays" in analyzing this situation. In particular, views are defined by the x-ray source in type 2 and by the detector in type 3 gantries. It is known that ray dependent errors are generally much more important than view dependent errors. It is shown that spatial resolution is primarily limited by the spacing between rays in any view, while the number of ray samples per beam width determines the extent of aliasing artifacts. Rotating detector gantries are especially susceptible to aliasing effects. It is shown that aliasing effects can distort the point spread function in a way that is highly dependent on the position of the point in the scanned field. Such effects can cause anomalies in the MTF functions as derived from points in machines with significant aliasing problems.

  9. Cross-Talk Limits of Highly Segmented Semiconductor Detectors

    NASA Astrophysics Data System (ADS)

    Pullia, Alberto; Weisshaar, Dirk; Zocca, Francesca; Bazzacco, Dino

    2011-06-01

    Cross-talk limits of monolithic highly-segmented semiconductor detectors for high-resolution X-gamma spectrometry are investigated. Cross-talk causes false signal components yielding amplitude losses and fold-dependent shifts of the spectral lines, which partially spoil the spectroscopic performance of the detector. Two complementary electrical models are developed, which describe quantitatively the inter-channel cross-talk of monolithic segmented detectors whose electrodes are read out by charge-sensitive preamplifiers. The first is here designated as Cross-Capacitance (CC) model, the second as Split-Charge (SC) model. The CC model builds around the parasitic capacitances Cij linking the preamplifier outputs and the neighbor channel inputs. The SC model builds around the finite-value of the decoupling capacitance CC used to read out the high-voltage detector electrode. The key parameters of the models are individuated and ideas are shown to minimize their impact. Using a quasi-coaxial germanium segmented detector it is found that the SC cross-talk becomes negligible for decoupling capacitances larger than 1 nF, where instead the CC cross-talk tends to dominate. The residual cross-talk may be reduced by minimization of stray capacitances Cij, through a careful design of the layout of the Printed Circuit Board (PCB) where the input transistors are mounted. Cij can be made as low as 5 fF, but it is shown that even in such case the impact of the CC cross-talk on the detector performance is not negligible. Finally, an algorithm for cross-talk correction is presented and elaborated.

  10. Status of NEMO

    NASA Astrophysics Data System (ADS)

    Migneco, E.; Aiello, S.; Ambriola, M.; Ameli, F.; Amore, I.; Anghinolfi, M.; Anzalone, A.; Barbarino, G.; Barbarito, E.; Battaglieri, M.; Bellotti, R.; Beverini, N.; Bonori, M.; Bouhdaef, B.; Brescia, M.; Cacopardo, G.; Cafagna, F.; Capone, A.; Caponetto, L.; Castorina, E.; Ceres, A.; Chiarusi, T.; Circella, M.; Cocimano, R.; Coniglione, R.; Cordelli, M.; Costa, M.; Cuneo, S.; D'Amico, A.; De Bonis, G.; De Marzo, C.; De Rosa, G.; De Vita, R.; Distefano, C.; Falchini, E.; Fiorello, C.; Flaminio, V.; Fratini, K.; Galeotti, S.; Gabrielli, A.; Gandolfi, E.; Giacomelli, G.; Grimaldi, A.; Habel, R.; Leonora, E.; Lonardo, A.; Longo, G.; Lo Presti, D.; Lucarelli, F.; Maccione, L.; Margiotta, A.; Martini, A.; Masullo, R.; Megna, R.; Mongelli, M.; Morganti, M.; Montaruli, T.; Musumeci, M.; Nicolau, C. A.; Orlando, A.; Osipenko, M.; Osteria, G.; Papaleo, R.; Pappalardo, V.; Petta, C.; Piattelli, P.; Raffaelli, F.; Raia, G.; Randazzo, N.; Reito, S.; Ricco, G.; Riccobene, G.; Ripani, M.; Rovelli, A.; Ruppi, M.; Russo, G. V.; Russo, S.; Sapienza, P.; Sedita, M.; Schuller, J.-P.; Shirokov, E.; Simeone, F.; Sipala, V.; Spurio, M.; Taiuti, M.; Terreni, G.; Trasatti, L.; Urso, S.; Valente, V.; Vicini, P.

    2006-11-01

    The activities towards the realization of a km3 Cherenkov neutrino detector carried out by the NEMO Collaboration are described. Long-term exploration of a 3500 m deep-sea site close to the Sicilian coast has shown that it is optimal for the installation of the detector. The realization of a Phase-1 project, which is under way, will validate the proposed technologies for the realization of the km3 detector on a Test Site at 2000 m depth. The realization of a new infrastructure on the candidate site (Phase-2 project) will provide the possibility to test detector components at 3500 m depth.

  11. An investigation of the operating characteristics of two PTW diamond detectors in photon and electron beams.

    PubMed

    De Angelis, C; Onori, S; Pacilio, M; Cirrone, G A P; Cuttone, G; Raffaele, L; Bucciolini, M; Mazzocchi, S

    2002-02-01

    The dosimetric properties of two PTW Riga diamond detectors type 60003 were studied in high-energy photon and electron therapy beam. Properties under study were current-voltage characteristic, polarization effect, time stability of response, dose response, dose-rate dependence, temperature stability, and beam quality dependence of the sensitivity factor. Differences were shown between the two detectors for most of the previous properties. Also, the observed behavior was, to some extent, different from what was reported in the PTW technical specifications. The necessity to characterize each diamond detector individually was addressed.

  12. Einstein Observations of Galactic supernova remnants

    NASA Technical Reports Server (NTRS)

    Seward, Frederick D.

    1990-01-01

    This paper summarizes the observations of Galactic supernova remnants with the imaging detectors of the Einstein Observatory. X-ray surface brightness contours of 47 remnants are shown together with gray-scale pictures. Count rates for these remnants have been derived and are listed for the HRI, IPC, and MPC detectors.

  13. Characterization and Selection of Polymer Materials for Binary Munitions Storage. Part 3. Branch Content Determination.

    DTIC Science & Technology

    1987-09-01

    accuracy. The data aquisition system combines a position- sensitive X-ray detector with a 65 kilobyte microcomputer capable of operating as a...The rapid X-ray diffraction system measures intensity versus 20 patterns by placing the detector with its sensitivity axis positioned parallel to the...plane of the diffractometer (see Figure 2). As shown in Figure 2, the detector sensitivity axis z is coplanar with both the incident beam and the

  14. Capacitor-type micrometeoroid detectors

    NASA Technical Reports Server (NTRS)

    Wortman, J. J.; Griffis, D. P.; Bryan, S. R.; Kinard, W.

    1986-01-01

    The metal oxide semiconductor (MOS) capacitor micrometeroid detector consists of a thin dielectric capacitor fabricated on a silicon wafer. In operation, the device is charged to a voltage level sufficiently near breakdown that micrometeoroid impacts will cause dielectric deformation or heating and subsequent arc-over at the point of impact. Each detector is capable of recording multiple impacts because of the self-healing characteristics of the device. Support instrumentation requirements consist of a voltage source and pulse counters that monitor the pulse of recharging current following every impact. An investigation has been conducted in which 0.5 to 5 micron diameter carbonized iron spheres traveling at velocities of 4 to 10 Km/sec were impacted on to detectors with either a dielectric thickness of 0.4 or 1.0 micron. This study demonstrated that an ion microprobe tuned to sufficiently high resolution can detect Fe remaining on the detector after the impact. Furthermore, it is also possible to resolve Fe ion images free of mass interferences from Si, for example, giving its spatial distribution after impact. Specifically this technique has shown that significant amounts of impacting particles remain in the crater and near it which can be analyzed for isotopic content. Further testing and calibration could lead to quantitive analysis. This study has shown that the capacitor type micrometeroid detector is capable of not only time and flux measurements but can also be used for isotopic analysis.

  15. A Prototype Silicon Compiler in Prolog

    DTIC Science & Technology

    1988-12-01

    A Prototype Silicon Compiler in Prolog 04 William Bush Gino Cheng Partrick C. McGeer Alvin M. Despain DTIC ELECTV JUL 281989 B Report No. UCB/CSD 88...the same register to variables in the same positions in invo- cation and head. Thus in ... g(A, B ),.. and g(X, Y) A and X share one register, and B ...example for a one-bit adder is given below. x = compl(or(and(c,or(a, b )),and(a, b ))). y = compl(or(and(x,or(a, b ,c)),and(a2b,c))). sum = compl(y). carry

  16. A Phase Field Model of Deformation Twinning: Nonlinear Theory and Numerical Simulations

    DTIC Science & Technology

    2011-03-01

    the system. Concepts for mod- eling multiphase systems were advanced by Steinbach et al. [3] and Steinbach and Apel [4]. Fried and Gurtin [5] and...a3b3 in a three- dimensional vector space. The outer product is (a ⊗ b) AB = aAbB. Juxtaposition implies summation over one set of adjacent indices...e.g., ( AB ) AB = AACBCB. The colon denotes summation over two sets of indices; e.g., A : B = AABBAB and (C : E) AB = CABCDECD. The transpose of amatrix is

  17. Thermal Conductivity of Metals and Alloys at Low Temperatures. A Review of the Literature

    DTIC Science & Technology

    1954-09-01

    between OnF and Ag , Ni. anda .. er.ta.. ducovruml s f (96) .. J m Sa . Oye-rveehg odciiy.. W.1 Powe28). sample .. &...... - .3a. IM. C.. Dp..... .Je...R. KikuchiBERYLIUM (932). Cominrl See figure 2, under "Metallic Elements".. E.J. Lewi 6.0 Ag ............. k= 1.16at27WC...9 Al 2 Zn, 0.1 .71 1.32 ........................ Aged . Mo. U ~5.Cu, 0.5 Si, 0.8 Fe, 0.5 Mn, 1.23 ......................... Quenched. MIA.B

  18. Increased Economic Relations Between China and Zambia in the Last Decade: Implications on Zambia’s Existing Bilateral Relations with the United States

    DTIC Science & Technology

    2013-12-13

    Pacific region, but also the world at large. China and the U.S. have agreed to a new model of relations, based on practical cooperation and...as a significant model to determine whether the increase in China and Zambia relations lead to a change in the nature of bilateral relations between...a model in countries with similar features and given the circumstances. The last decade has seen China step up its economic activities on the

  19. Smile detectors correlation

    NASA Astrophysics Data System (ADS)

    Yuksel, Kivanc; Chang, Xin; Skarbek, Władysław

    2017-08-01

    The novel smile recognition algorithm is presented based on extraction of 68 facial salient points (fp68) using the ensemble of regression trees. The smile detector exploits the Support Vector Machine linear model. It is trained with few hundreds exemplar images by SVM algorithm working in 136 dimensional space. It is shown by the strict statistical data analysis that such geometric detector strongly depends on the geometry of mouth opening area, measured by triangulation of outer lip contour. To this goal two Bayesian detectors were developed and compared with SVM detector. The first uses the mouth area in 2D image, while the second refers to the mouth area in 3D animated face model. The 3D modeling is based on Candide-3 model and it is performed in real time along with three smile detectors and statistics estimators. The mouth area/Bayesian detectors exhibit high correlation with fp68/SVM detector in a range [0:8; 1:0], depending mainly on light conditions and individual features with advantage of 3D technique, especially in hard light conditions.

  20. Energy resolution improvement of CdTe detectors by using the principal component analysis technique

    NASA Astrophysics Data System (ADS)

    Alharbi, T.

    2018-02-01

    In this paper, we report on the application of the Principal Component Analysis (PCA) technique for the improvement of the γ-ray energy resolution of CdTe detectors. The PCA technique is used to estimate the amount of charge-trapping effect which is reflected in the shape of each detector pulse, thereby correcting for the charge-trapping effect. The details of the method are described and the results obtained with a CdTe detector are shown. We have achieved an energy resolution of 1.8 % (FWHM) at 662 keV with full detection efficiency from a 1 mm thick CdTe detector which gives an energy resolution of 4.5 % (FWHM) by using the standard pulse processing method.

  1. [The use of a detector of the extremely weak radiation as a variometer of gravitation field].

    PubMed

    Gorshkov, E S; Bondarenko, E G; Shapovalov, S N; Sokolovskiĭ, V V; Troshichev, O A

    2001-01-01

    It was shown that the detector of extremely weak radiation with selectively increased sensitivity to the nonelectromagnetic, including the gravitational component of the spectrum of active physical fields can be used as the basis for constructing a variometer of gravitational field of a new type.

  2. Gear Tooth Wear Detection Algorithm

    NASA Technical Reports Server (NTRS)

    Delgado, Irebert R.

    2015-01-01

    Vibration-based condition indicators continue to be developed for Health Usage Monitoring of rotorcraft gearboxes. Testing performed at NASA Glenn Research Center have shown correlations between specific condition indicators and specific types of gear wear. To speed up the detection and analysis of gear teeth, an image detection program based on the Viola-Jones algorithm was trained to automatically detect spiral bevel gear wear pitting. The detector was tested using a training set of gear wear pictures and a blind set of gear wear pictures. The detector accuracy for the training set was 75 percent while the accuracy for the blind set was 15 percent. Further improvements on the accuracy of the detector are required but preliminary results have shown its ability to automatically detect gear tooth wear. The trained detector would be used to quickly evaluate a set of gear or pinion pictures for pits, spalls, or abrasive wear. The results could then be used to correlate with vibration or oil debris data. In general, the program could be retrained to detect features of interest from pictures of a component taken over a period of time.

  3. A novel x-ray detector design with higher DQE and reduced aliasing: Theoretical analysis of x-ray reabsoprtion in detector converter material

    NASA Astrophysics Data System (ADS)

    Nano, Tomi; Escartin, Terenz; Karim, Karim S.; Cunningham, Ian A.

    2016-03-01

    The ability to improve visualization of structural information in digital radiography without increasing radiation exposures requires improved image quality across all spatial frequencies, especially at high frequencies. The detective quantum efficiency (DQE) as a function of spatial frequency quantifies image quality given by an x-ray detector. We present a method of increasing DQE at high spatial frequencies by improving the modulation transfer function (MTF) and reducing noise aliasing. The Apodized Aperature Pixel (AAP) design uses a detector with micro-elements to synthesize desired pixels and provide higher DQE than conventional detector designs. A cascaded system analysis (CSA) that incorporates x-ray interactions is used for comparison of the theoretical MTF, noise power spectrum (NPS), and DQE. Signal and noise transfer through the converter material is shown to consist of correlated an uncorrelated terms. The AAP design was shown to improve the DQE of both material types that have predominantly correlated transfer (such as CsI) and predominantly uncorrelated transfer (such as Se). Improvement in the MTF by 50% and the DQE by 100% at the sampling cut-off frequency is obtained when uncorrelated transfer is prevalent through the converter material. Optimizing high-frequency DQE results in improved image contrast and visualization of small structures and fine-detail.

  4. Home Camera-Based Fall Detection System for the Elderly.

    PubMed

    de Miguel, Koldo; Brunete, Alberto; Hernando, Miguel; Gambao, Ernesto

    2017-12-09

    Falls are the leading cause of injury and death in elderly individuals. Unfortunately, fall detectors are typically based on wearable devices, and the elderly often forget to wear them. In addition, fall detectors based on artificial vision are not yet available on the market. In this paper, we present a new low-cost fall detector for smart homes based on artificial vision algorithms. Our detector combines several algorithms (background subtraction, Kalman filtering and optical flow) as input to a machine learning algorithm with high detection accuracy. Tests conducted on over 50 different fall videos have shown a detection ratio of greater than 96%.

  5. A T0/Trigger detector for the External Target Experiment at CSR

    NASA Astrophysics Data System (ADS)

    Hu, D.; Shao, M.; Sun, Y.; Li, C.; Chen, H.; Tang, Z.; Zhang, Y.; Zhou, J.; Zeng, H.; Zhao, X.; You, W.; Song, G.; Deng, P.; Lu, J.; Zhao, L.

    2017-06-01

    A new T0/Trigger detector based on multi-gap resistive plate chamber (MRPC) technology has been constructed and tested for the external target experiment (ETE) at HIRFL-CSR. It measures the multiplicity and timing information of particles produced in heavy-ion collisions at the target region, providing necessary event collision time (T0) and collision centrality with high precision. Monte-Carlo simulation shows a time resolution of several tens of picosecond can be achieved at central collisions. The experimental tests have been performed for this prototype detector at the CSR-ETE. The preliminary results are shown to demonstrate the performance of the T0/Trigger detector.

  6. Development and Prototyping of the PROSPECT Antineutrino Detector

    NASA Astrophysics Data System (ADS)

    Commeford, Kelley; Prospect Collaboration

    2017-01-01

    The PROSPECT experiment will make the most precise measurement of the 235U reactor antineutrino spectrum as well as search for sterile neutrinos using a segmented Li-loaded liquid scintillator neutrino detector. Several prototype detectors of increasing size, complexity, and fidelity have been constructed and tested as part of the PROSPECT detector development program. The challenges to overcome include the efficient rejection of cosmogenic background and collection of optical photons in a compact volume. Design choices regarding segment structure and layout, calibration source deployment, and optical collection methods are discussed. Results from the most recent multi-segment prototype, PROSPECT-50, will also be shown.

  7. Home Camera-Based Fall Detection System for the Elderly

    PubMed Central

    de Miguel, Koldo

    2017-01-01

    Falls are the leading cause of injury and death in elderly individuals. Unfortunately, fall detectors are typically based on wearable devices, and the elderly often forget to wear them. In addition, fall detectors based on artificial vision are not yet available on the market. In this paper, we present a new low-cost fall detector for smart homes based on artificial vision algorithms. Our detector combines several algorithms (background subtraction, Kalman filtering and optical flow) as input to a machine learning algorithm with high detection accuracy. Tests conducted on over 50 different fall videos have shown a detection ratio of greater than 96%. PMID:29232846

  8. Design and optimization of a novel 3D detector: The 3D-open-shell-electrode detector

    NASA Astrophysics Data System (ADS)

    Liu, Manwen; Tan, Jian; Li, Zheng

    2018-04-01

    A new type of three-dimensional (3D) detector, namely 3D-Open-Shell-Electrode Detector (3DOSED), is proposed in this study. In a 3DOSED, the trench electrode can be etched all the way through the detector thickness, totally eliminating the low electric field region existed in the conventional 3D-Trench-Electrode detector. Full 3D technology computer-aided design (TCAD) simulations have been done on this novel silicon detector structure. Through comparing of the simulation results of the detector, we can obtain the best design of the 3SOSED. In addition, simulation results show that, as compared to the conventional 3D detector, the proposed 3DOSED can improve not only detector charge collection efficiency but also its radiation hardness with regard to solving the trapping problem in the detector bulk. What is more, it has been shown that detector full depletion voltage is also slightly reduced, which can improve the utility aspects of the detector. When compared to the conventional 3D detector, we find that the proposed novel 3DOSED structure has better electric potential and electric field distributions, and better electrical properties such as detector full depletion voltage. In 3DOSED array, each pixel cell is isolated from each other by highly doped trenches, but also electrically and physically connected with each other through the remaining silicon bulk between broken electrodes.

  9. Characterization of silicon carbide and diamond detectors for neutron applications

    NASA Astrophysics Data System (ADS)

    Hodgson, M.; Lohstroh, A.; Sellin, P.; Thomas, D.

    2017-10-01

    The presence of carbon atoms in silicon carbide and diamond makes these materials ideal candidates for direct fast neutron detectors. Furthermore the low atomic number, strong covalent bonds, high displacement energies, wide bandgap and low intrinsic carrier concentrations make these semiconductor detectors potentially suitable for applications where rugged, high-temperature, low-gamma-sensitivity detectors are required, such as active interrogation, electronic personal neutron dosimetry and harsh environment detectors. A thorough direct performance comparison of the detection capabilities of semi-insulating silicon carbide (SiC-SI), single crystal diamond (D-SC), polycrystalline diamond (D-PC) and a self-biased epitaxial silicon carbide (SiC-EP) detector has been conducted and benchmarked against a commercial silicon PIN (Si-PIN) diode, in a wide range of alpha (Am-241), beta (Sr/Y-90), ionizing photon (65 keV to 1332 keV) and neutron radiation fields (including 1.2 MeV to 16.5 MeV mono-energetic neutrons, as well as neutrons from AmBe and Cf-252 sources). All detectors were shown to be able to directly detect and distinguish both the different radiation types and energies by using a simple energy threshold discrimination method. The SiC devices demonstrated the best neutron energy discrimination ratio (E\\max (n=5 MeV)/E\\max (n=1 MeV)  ≈5), whereas a superior neutron/photon cross-sensitivity ratio was observed in the D-PC detector (E\\max (AmBe)/E\\max (Co-60)  ≈16). Further work also demonstrated that the cross-sensitivity ratios can be improved through use of a simple proton-recoil conversion layer. Stability issues were also observed in the D-SC, D-PC and SiC-SI detectors while under irradiation, namely a change of energy peak position and/or count rate with time (often referred to as the polarization effect). This phenomenon within the detectors was non-debilitating over the time period tested (> 5 h) and, as such, stable operation was possible. Furthermore, the D-SC, self-biased SiC-EP and semi-insulating SiC detectors were shown to operate over the temperature range -60 °C to +100 °C.

  10. Demodulation Algorithms for the Ofdm Signals in the Time- and Frequency-Scattering Channels

    NASA Astrophysics Data System (ADS)

    Bochkov, G. N.; Gorokhov, K. V.; Kolobkov, A. V.

    2016-06-01

    We consider a method based on the generalized maximum-likelihood rule for solving the problem of reception of the signals with orthogonal frequency division multiplexing of their harmonic components (OFDM signals) in the time- and frequency-scattering channels. The coherent and incoherent demodulators effectively using the time scattering due to the fast fading of the signal are developed. Using computer simulation, we performed comparative analysis of the proposed algorithms and well-known signal-reception algorithms with equalizers. The proposed symbolby-symbol detector with decision feedback and restriction of the number of searched variants is shown to have the best bit-error-rate performance. It is shown that under conditions of the limited accuracy of estimating the communication-channel parameters, the incoherent OFDMsignal detectors with differential phase-shift keying can ensure a better bit-error-rate performance compared with the coherent OFDM-signal detectors with absolute phase-shift keying.

  11. Modelling of MWIR HgCdTe complementary barrier HOT detector

    NASA Astrophysics Data System (ADS)

    Martyniuk, Piotr; Rogalski, Antoni

    2013-02-01

    The paper reports on the photoelectrical performance of medium wavelength infrared (MWIR) HgCdTe complementary barrier infrared detector (CBIRD) with n-type barriers. CBIRD nB1nB2 HgCdTe/B1,2-n type detector is modelled with commercially available software APSYS by Crosslight Software Inc. The detailed analysis of the detector's performance such as dark current, photocurrent, responsivity, detectivity versus applied bias, operating temperature, and structural parameters (cap, barriers and absorber doping; and absorber and barriers compositions) are performed pointing out optimal working conditions. Both conduction and valence bands' alignment of the HgCdTe CBIRD structure are calculated stressing their importance on detectors performance. It is shown that higher operation temperature (HOT) conditions achieved by commonly used thermoelectric (TE) coolers allows to obtain detectivities D∗ ≈ 2 × 1010 cm Hz1/2/W at T = 200 K and reverse polarisation V = 400 mV, and differential resistance area product RA = 0.9 Ωcm2 at T = 230 K for V = 50 mV, respectively. Finally, CBIRD nB1nB2 HgCdTe/B1,2-n type state of the art is compared to unipolar barrier HgCdTe nBn/B-n type detector, InAs/GaSb/B-Al0.2Ga0.8Sb type-II superlattice (T2SL) nBn detectors, InAs/GaSb T2SLs PIN and the HOT HgCdTe bulk photodiodes' performance operated at near-room temperature (T = 230 K). It was shown that the RA product of the MWIR CBIRD HgCdTe detector is either comparable or higher (depending on structural parameters) to the state of the art of HgCdTe HOT bulk photodiodes and both AIIIBV 6.1 Å family T2SLs nBn and PIN detectors.

  12. Radiation hardness of thin Low Gain Avalanche Detectors

    NASA Astrophysics Data System (ADS)

    Kramberger, G.; Carulla, M.; Cavallaro, E.; Cindro, V.; Flores, D.; Galloway, Z.; Grinstein, S.; Hidalgo, S.; Fadeyev, V.; Lange, J.; Mandić, I.; Medin, G.; Merlos, A.; McKinney-Martinez, F.; Mikuž, M.; Quirion, D.; Pellegrini, G.; Petek, M.; Sadrozinski, H. F.-W.; Seiden, A.; Zavrtanik, M.

    2018-05-01

    Low Gain Avalanche Detectors (LGAD) are based on a n++-p+-p-p++ structure where an appropriate doping of the multiplication layer (p+) leads to high enough electric fields for impact ionization. Gain factors of few tens in charge significantly improve the resolution of timing measurements, particularly for thin detectors, where the timing performance was shown to be limited by Landau fluctuations. The main obstacle for their operation is the decrease of gain with irradiation, attributed to effective acceptor removal in the gain layer. Sets of thin sensors were produced by two different producers on different substrates, with different gain layer doping profiles and thicknesses (45, 50 and 80 μm). Their performance in terms of gain/collected charge and leakage current was compared before and after irradiation with neutrons and pions up to the equivalent fluences of 5 ṡ 1015 cm-2. Transient Current Technique and charge collection measurements with LHC speed electronics were employed to characterize the detectors. The thin LGAD sensors were shown to perform much better than sensors of standard thickness (∼300 μm) and offer larger charge collection with respect to detectors without gain layer for fluences < 2 ṡ 1015 cm-2. Larger initial gain prolongs the beneficial performance of LGADs. Pions were found to be more damaging than neutrons at the same equivalent fluence, while no significant difference was found between different producers. At very high fluences and bias voltages the gain appears due to deep acceptors in the bulk, hence also in thin standard detectors.

  13. Heat Transfer Issues in Thin-Film Thermal Radiation Detectors

    NASA Technical Reports Server (NTRS)

    Barry, Mamadou Y.

    1999-01-01

    The Thermal Radiation Group at Virginia Polytechnic Institute and State University has been working closely with scientists and engineers at NASA's Langley Research Center to develop accurate analytical and numerical models suitable for designing next generation thin-film thermal radiation detectors for earth radiation budget measurement applications. The current study provides an analytical model of the notional thermal radiation detector that takes into account thermal transport phenomena, such as the contact resistance between the layers of the detector, and is suitable for use in parameter estimation. It was found that the responsivity of the detector can increase significantly due to the presence of contact resistance between the layers of the detector. Also presented is the effect of doping the thermal impedance layer of the detector with conducting particles in order to electrically link the two junctions of the detector. It was found that the responsivity and the time response of the doped detector decrease significantly in this case. The corresponding decrease of the electrical resistance of the doped thermal impedance layer is not sufficient to significantly improve the electrical performance of the detector. Finally, the "roughness effect" is shown to be unable to explain the decrease in the thermal conductivity often reported for thin-film layers.

  14. Matching Condition of Direct THz-Signal Detection from On-Chip Resonating Antennas with CMOS Transistors in Non-resonant Plasma Wave Mode

    NASA Astrophysics Data System (ADS)

    Chai, S.; Lim, S.; Kim, C.-Y.; Hong, S.

    2018-06-01

    This paper presents matching condition for detector at THz frequencies, which directly read signals from an integrated antenna. We use direct THz-signal detections with CMOS transistors in non-resonant plasma wave mode, which are embedded in on-chip resonating antennas. The detector detects THz envelope signals directly from the side edges of the on-chip patch antennas. The signal detection mechanism is studied in the view of the impedance conditions of the antenna and the detector. The detectors are implemented with stacked transistors structures to achieve high responsivity. The measured responsivities of the detectors with antenna impedances that were simulated to be 599.7, 912.3, 1565, and 3190.6 Ω agree well with the calculated values. Moreover, the responsivity dependence on the detector impedance is shown with two different input impedances of the detectors. Since CMOS circuit models from foundry are not accurate at frequencies higher than f t , the matching guideline between the antenna and the detector is very useful in designing high responsivity detectors. This study found that a detector has to have a large input impedance conjugately matched to the antenna's impedance to have high responsivity.

  15. Matching Condition of Direct THz-Signal Detection from On-Chip Resonating Antennas with CMOS Transistors in Non-resonant Plasma Wave Mode

    NASA Astrophysics Data System (ADS)

    Chai, S.; Lim, S.; Kim, C.-Y.; Hong, S.

    2018-04-01

    This paper presents matching condition for detector at THz frequencies, which directly read signals from an integrated antenna. We use direct THz-signal detections with CMOS transistors in non-resonant plasma wave mode, which are embedded in on-chip resonating antennas. The detector detects THz envelope signals directly from the side edges of the on-chip patch antennas. The signal detection mechanism is studied in the view of the impedance conditions of the antenna and the detector. The detectors are implemented with stacked transistors structures to achieve high responsivity. The measured responsivities of the detectors with antenna impedances that were simulated to be 599.7, 912.3, 1565, and 3190.6 Ω agree well with the calculated values. Moreover, the responsivity dependence on the detector impedance is shown with two different input impedances of the detectors. Since CMOS circuit models from foundry are not accurate at frequencies higher than f t , the matching guideline between the antenna and the detector is very useful in designing high responsivity detectors. This study found that a detector has to have a large input impedance conjugately matched to the antenna's impedance to have high responsivity.

  16. Centroid measurement error of CMOS detector in the presence of detector noise for inter-satellite optical communications

    NASA Astrophysics Data System (ADS)

    Li, Xin; Zhou, Shihong; Ma, Jing; Tan, Liying; Shen, Tao

    2013-08-01

    CMOS is a good candidate tracking detector for satellite optical communications systems with outstanding feature of sub-window for the development of APS (Active Pixel Sensor) technology. For inter-satellite optical communications it is critical to estimate the direction of incident laser beam precisely by measuring the centroid position of incident beam spot. The presence of detector noise results in measurement error, which degrades the tracking performance of systems. In this research, the measurement error of CMOS is derived taking consideration of detector noise. It is shown that the measurement error depends on pixel noise, size of the tracking sub-window (pixels number), intensity of incident laser beam, relative size of beam spot. The influences of these factors are analyzed by numerical simulation. We hope the results obtained in this research will be helpful in the design of CMOS detector satellite optical communications systems.

  17. Low pressure ion chromatography with a low cost paired emitter-detector diode based detector for the determination of alkaline earth metals in water samples.

    PubMed

    Barron, Leon; Nesterenko, Pavel N; Diamond, Dermot; O'Toole, Martina; Lau, King Tong; Paull, Brett

    2006-09-01

    The use of a low pressure ion chromatograph based upon short (25 mm x 4.6 mm) surfactant coated monolithic columns and a low cost paired emitter-detector diode (PEDD) based detector, for the determination of alkaline earth metals in aqueous matrices is presented. The system was applied to the separation of magnesium, calcium, strontium and barium in less than 7min using a 0.15M KCl mobile phase at pH 3, with post-column reaction detection at 570 nm using o-cresolphthalein complexone. A comparison of the performance of the PEDD detector with a standard laboratory absorbance detector is shown, with limits of detection for magnesium and calcium using the low cost PEDD detector equal to 0.16 and 0.23 mg L(-1), respectively. Finally, the developed system was used for the determination of calcium and magnesium in a commercial spring water sample.

  18. In-core flux sensor evaluations at the ATR critical facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Troy Unruh; Benjamin Chase; Joy Rempe

    2014-09-01

    Flux detector evaluations were completed as part of a joint Idaho State University (ISU) / Idaho National Laboratory (INL) / French Atomic Energy commission (CEA) ATR National Scientific User Facility (ATR NSUF) project to compare the accuracy, response time, and long duration performance of several flux detectors. Special fixturing developed by INL allows real-time flux detectors to be inserted into various ATRC core positions and perform lobe power measurements, axial flux profile measurements, and detector cross-calibrations. Detectors initially evaluated in this program include the French Atomic Energy Commission (CEA)-developed miniature fission chambers; specialized self-powered neutron detectors (SPNDs) developed by themore » Argentinean National Energy Commission (CNEA); specially developed commercial SPNDs from Argonne National Laboratory. As shown in this article, data obtained from this program provides important insights related to flux detector accuracy and resolution for subsequent ATR and CEA experiments and flux data required for bench-marking models in the ATR V&V Upgrade Initiative.« less

  19. Spatiotemporal Monte Carlo transport methods in x-ray semiconductor detectors: application to pulse-height spectroscopy in a-Se.

    PubMed

    Fang, Yuan; Badal, Andreu; Allec, Nicholas; Karim, Karim S; Badano, Aldo

    2012-01-01

    The authors describe a detailed Monte Carlo (MC) method for the coupled transport of ionizing particles and charge carriers in amorphous selenium (a-Se) semiconductor x-ray detectors, and model the effect of statistical variations on the detected signal. A detailed transport code was developed for modeling the signal formation process in semiconductor x-ray detectors. The charge transport routines include three-dimensional spatial and temporal models of electron-hole pair transport taking into account recombination and trapping. Many electron-hole pairs are created simultaneously in bursts from energy deposition events. Carrier transport processes include drift due to external field and Coulombic interactions, and diffusion due to Brownian motion. Pulse-height spectra (PHS) have been simulated with different transport conditions for a range of monoenergetic incident x-ray energies and mammography radiation beam qualities. Two methods for calculating Swank factors from simulated PHS are shown, one using the entire PHS distribution, and the other using the photopeak. The latter ignores contributions from Compton scattering and K-fluorescence. Comparisons differ by approximately 2% between experimental measurements and simulations. The a-Se x-ray detector PHS responses simulated in this work include three-dimensional spatial and temporal transport of electron-hole pairs. These PHS were used to calculate the Swank factor and compare it with experimental measurements. The Swank factor was shown to be a function of x-ray energy and applied electric field. Trapping and recombination models are all shown to affect the Swank factor.

  20. Blocking Losses With a Photon Counter

    NASA Technical Reports Server (NTRS)

    Moision, Burce E.; Piazzolla, Sabino

    2012-01-01

    It was not known how to assess accurately losses in a communications link due to photodetector blocking, a phenomenon wherein a detector is rendered inactive for a short time after the detection of a photon. When used to detect a communications signal, blocking leads to losses relative to an ideal detector, which may be measured as a reduction in the communications rate for a given received signal power, or an increase in the signal power required to support the same communications rate. This work involved characterizing blocking losses for single detectors and arrays of detectors. Blocking may be mitigated by spreading the signal intensity over an array of detectors, reducing the count rate on any one detector. A simple approximation was made to the blocking loss as a function of the probability that a detector is unblocked at a given time, essentially treating the blocking probability as a scaling of the detection efficiency. An exact statistical characterization was derived for a single detector, and an approximation for multiple detectors. This allowed derivation of several accurate approximations to the loss. Methods were also derived to account for a rise time in recovery, and non-uniform illumination due to diffraction and atmospheric distortion of the phase front. It was assumed that the communications signal is intensity modulated and received by an array of photon-counting photodetectors. For the purpose of this analysis, it was assumed that the detectors are ideal, in that they produce a signal that allows one to reproduce the arrival times of electrons, produced either as photoelectrons or from dark noise, exactly. For single detectors, the performance of the maximum-likelihood (ML) receiver in blocking is illustrated, as well as a maximum-count (MC) receiver, that, when receiving a pulse-position-modulated (PPM) signal, selects the symbol corresponding to the slot with the largest electron count. Whereas the MC receiver saturates at high count rates, the ML receiver may not. The loss in capacity, symbol-error-rate (SER), and count-rate were numerically computed. It was shown that the capacity and symbol-error-rate losses track, whereas the count-rate loss does not generally reflect the SER or capacity loss, as the slot-statistics at the detector output are no longer Poisson. It is also shown that the MC receiver loss may be accurately predicted for dead times on the order of a slot.

  1. Preliminary design report, Large Space Telescope OTA/SI Phase B study: High speed area photometer. [systems analysis

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A photometer is examined which combines several features from separate instruments into a single package. The design presented has both point and area photometry capability with provision for inserting filters to provide spectral discrimination. The electronics provide for photon counting mode for the point detectors and both photon counting and analog modes for the area detector. The area detector also serves as a target locating device for the point detectors. Topics discussed include: (1) electronic equipment requirements, (2) optical properties, (3) structural housing for the instrument, (4) motors and other mechanical components, (5) ground support equipment, and (6) environment control for the instrument. Engineering drawings and block diagrams are shown.

  2. 35t Prototype Detector for Experiment at Long Base Line Neutrino Facility (ELBNF) Far Detector

    NASA Astrophysics Data System (ADS)

    Santucci, Gabriel; Elbnf Collaboration

    2015-04-01

    The 35ton prototype detector is a Liquid Argon Time Projection Chamber (LAr TPC) utilizing a membrane cryostat. It serves as a prototype for testing technology proposed for the ELBNF far detector. The construction of the prototype is an essential part of the ELBNF project due to the large amount of new technologies introduced for the far detector. In early 2014, it was shown that the membrane cryostat technology was able to reach and maintain the required LAr purity and an electron lifetime of 2.5 ms was achieved. The goals for the next phase include the installation of a fully functional TPC using the novel designs for the ELBNF far detector as much as possible. This includes the installation of the cold electronics, scintillation photon detectors and multiple Anode Plane Arrays with wrapped wires. In this talk I will review the status of the 35t prototype detector and describe what has been accomplished during 2014 and early 2015, including the commissioning phase and the early stages of data taking from cosmic-rays.

  3. Analysis and Quantification of Coupling Mechanisms of External Signal Perturbations on Silicon Detectors for Particle Physics Experiments

    NASA Astrophysics Data System (ADS)

    Arteche, F.; Rivetta, C.; Iglesias, M.; Echeverria, I.

    2016-05-01

    Silicon detectors have been used in astrophysics satellites and particle detectors for high energy physics (HEP) experiments. For HEP applications, EMC studies have been conducted in silicon detectors to characterize the impact of external noise on the system. They have shown that problems associated with the new generation of silicon detectors are related with interferences generated by the power supplies and auxiliary equipment connected to the device. Characterization of these interferences along with the coupling and their propagation into the susceptible front-end circuits is required for a successful integration of these systems. This paper presents the analysis of the sensitivity curves and coupling mechanisms between the noise and the front-end electronics that have been observed during the characterization of two silicon detector prototypes: the CMS-Silicon tracker detector (CMS-ST) and Silicon Vertex Detector (Belle II-SVD). As a result of these studies, it is possible to identify critical elements in prototypes to take corrective actions in the design and improve the front-end electronics performance.

  4. Neutron response characterization for an EJ299-33 plastic scintillation detector

    DOE PAGES

    Lawrence, Chris C.; Febbraro, Michael; Massey, Thomas N.; ...

    2014-05-10

    Organic scintillation detectors have shown promise as neutron detectors for characterizing special nuclear materials in various arms-control and homeland security applications. Recent advances have yielded a new plastic scintillator - EJ299-33 - with pulse-shape-discrimination (PSD) capability. Plastic scintillators would have a much expanded range of deployment relative to liquids and crystals. Here in this paper, we present a full characterization of pulse height response to fission-energy neutrons for an EJ299-33 detector with 7.62-by-7.62-cm cylindrical active volume, and compare with an EJ309 liquid scintillator in the same assembly. Scintillation light output relations, energy resolutions, and response matrices are presented for bothmore » detectors. A Continuous spectrum neutron source, obtained via the bombardment of 27Al with 7.44-MeV deuterons at the Edwards Accelerator Facility at Ohio University, was used for the measurement. A new procedure for evaluating and comparing PSD performance is presented which accounts for the effect of the light output relation on the ability to detect low energy neutrons. The EJ299-33 is shown to have considerable deficit in matrix condition, and in PSD figure of merit when compared to EJ309, especially when neutron energy is taken into account. Furthermore the EJ299 is likely to bring a modest PSD capability into a array of held applications that are not accessible to liquids or crystals.« less

  5. Optomechanical Design of Ten Modular Cameras for the Mars Exploration Rovers

    NASA Technical Reports Server (NTRS)

    Ford, Virginia G.; Karlmann, Paul; Hagerott, Ed; Scherr, Larry

    2003-01-01

    This viewgraph presentation reviews the design and fabrication of the modular cameras for the Mars Exploration Rovers. In the 2003 mission there were to be 2 landers and 2 rovers, each were to have 10 cameras each. Views of the camera design, the lens design, the lens interface with the detector assembly, the detector assembly, the electronics assembly are shown.

  6. Shake, Rattle and Roll: James Webb Telescope Components Pass Tests

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image shows a model of one of three detectors for the Mid-Infrared Instrument on NASA's upcoming James Webb Space Telescope. The detector, which looks green in this picture, and is similar to the charge-coupled devices, or 'CCDs,' in digital cameras, is housed in the brick-like unit shown here, called a focal plane module.

  7. Polyethylene Naphthalate Scintillator: A Novel Detector for the Dosimetry of Radioactive Ophthalmic Applicators.

    PubMed

    Flühs, Dirk; Flühs, Andrea; Ebenau, Melanie; Eichmann, Marion

    2015-09-01

    Dosimetric measurements in small radiation fields with large gradients, such as eye plaque dosimetry with β or low-energy photon emitters, require dosimetrically almost water-equivalent detectors with volumes of <1 mm(3) and linear responses over several orders of magnitude. Polyvinyltoluene-based scintillators fulfil these conditions. Hence, they are a standard for such applications. However, they show disadvantages with regard to certain material properties and their dosimetric behaviour towards low-energy photons. Polyethylene naphthalate, recently recognized as a scintillator, offers chemical, physical and basic dosimetric properties superior to polyvinyltoluene. Its general applicability as a clinical dosimeter, however, has not been shown yet. To prove this applicability, extensive measurements at several clinical photon and electron radiation sources, ranging from ophthalmic plaques to a linear accelerator, were performed. For all radiation qualities under investigation, covering a wide range of dose rates, a linearity of the detector response to the dose was shown. Polyethylene naphthalate proved to be a suitable detector material for the dosimetry of ophthalmic plaques, including low-energy photon emitters and other small radiation fields. Due to superior properties, it has the potential to replace polyvinyltoluene as the standard scintillator for such applications.

  8. Further developments of series-connected superconducting tunnel junction to radiation detection

    NASA Astrophysics Data System (ADS)

    Kurakado, Masahiko; Ohsawa, Daisuke; Katano, Rintaro; Ito, Shin; Isozumi, Yasuhito

    1997-10-01

    One of the promising radiation detection devices for various practical applications is the series-connected superconducting tunnel junction (STJ) detector. In this article, interesting topics of the detectors are described since our previous work: e.g., more than two order higher detection efficiency compared with single STJ detectors, high count rate detection, and position resolution. Detectors were cooled to 0.35-0.4 K by means of a convenient 3He cryostat. The 5.9 and 6.5 keV x rays from 55Fe are separated by a detector specially designed for x-ray detection. The possible count rate of the series-junction detector estimated from the shaping-time constant applied in the measurements is high, e.g., over 104 counts per second. A series-junction detector equipped with a position sensing mechanism has shown a position resolution of about 35 μm in a sensing area with a radius of 1.1 mm. The position resolution of series junctions improves the energy resolution. A new type series-connected STJ detector is also proposed, i.e., the dispersed multitrap series-junction detector, for further improvement of detection efficiency and energy resolution.

  9. Automatic detection of echolocation clicks based on a Gabor model of their waveform.

    PubMed

    Madhusudhana, Shyam; Gavrilov, Alexander; Erbe, Christine

    2015-06-01

    Prior research has shown that echolocation clicks of several species of terrestrial and marine fauna can be modelled as Gabor-like functions. Here, a system is proposed for the automatic detection of a variety of such signals. By means of mathematical formulation, it is shown that the output of the Teager-Kaiser Energy Operator (TKEO) applied to Gabor-like signals can be approximated by a Gaussian function. Based on the inferences, a detection algorithm involving the post-processing of the TKEO outputs is presented. The ratio of the outputs of two moving-average filters, a Gaussian and a rectangular filter, is shown to be an effective detection parameter. Detector performance is assessed using synthetic and real (taken from MobySound database) recordings. The detection method is shown to work readily with a variety of echolocation clicks and in various recording scenarios. The system exhibits low computational complexity and operates several times faster than real-time. Performance comparisons are made to other publicly available detectors including pamguard.

  10. Using Purpose-Built Functions and Block Hashes to Enable Small Block and Sub-file Forensics

    DTIC Science & Technology

    2010-01-01

    JPEGs. We tested precarve using the nps-2009-canon2-gen6 (Garfinkel et al., 2009) disk image. The disk image was created with a 32 MB SD card and a...analysis of n-grams in the fragment. Fig. 1 e Usage of a 160 GB iPod reported by iTunes 8.2.1 (6) (top), as reported by the file system (bottom center), and...as computing with random sampling (bottom right). Note that iTunes usage actually in GiB, even though the program displays the “GB” label. Fig. 2 e

  11. Calibration methods and tools for KM3NeT

    NASA Astrophysics Data System (ADS)

    Kulikovskiy, Vladimir

    2016-04-01

    The KM3NeT detectors, ARCA and ORCA, composed of several thousands digital optical modules, are in the process of their realization in the Mediterranean Sea. Each optical module contains 31 3-inch photomultipliers. Readout of the optical modules and other detector components is synchronized at the level of sub-nanoseconds. The position of the module is measured by acoustic piezo detectors inside the module and external acoustic emitters installed on the bottom of the sea. The orientation of the module is obtained with an internal attitude and heading reference system chip. Detector calibration, i.e. timing, positioning and sea-water properties, is overviewed in this talk and discussed in detail in this conference. Results of the procedure applied to the first detector unit ready for installation in the deep sea will be shown.

  12. Gamma-gamma coincidence performance of LaBr 3:Ce scintillation detectors vs HPGe detectors in high count-rate scenarios

    DOE PAGES

    Drescher, A.; Yoho, M.; Landsberger, S.; ...

    2017-01-15

    In this study, a radiation detection system consisting of two cerium doped lanthanum bromide (LaBr 3:Ce) scintillation detectors in a gamma-gamma coincidence configuration has been used to demonstrate the advantages that coincident detection provides relative to a single detector, and the advantages that LaBr 3:Ce detectors provide relative to high purity germanium (HPGe) detectors. Signal to noise ratios of select photopeak pairs for these detectors have been compared to high-purity germanium (HPGe) detectors in both single and coincident detector configurations in order to quantify the performance of each detector configuration. The efficiency and energy resolution of LaBr 3:Ce detectors havemore » been determined and compared to HPGe detectors. Coincident gamma-ray pairs from the radionuclides 152Eu and 133Ba have been identified in a sample that is dominated by 137Cs. Gamma-gamma coincidence successfully reduced the Compton continuum from the large 137Cs peak, revealed several coincident gamma energies characteristic of these nuclides, and improved the signal-to-noise ratio relative to single detector measurements. LaBr 3:Ce detectors performed at count rates multiple times higher than can be achieved with HPGe detectors. The standard background spectrum consisting of peaks associated with transitions within the LaBr 3:Ce crystal has also been significantly reduced. Finally, it is shown that LaBr 3:Ce detectors have the unique capability to perform gamma-gamma coincidence measurements in very high count rate scenarios, which can potentially benefit nuclear safeguards in situ measurements of spent nuclear fuel.« less

  13. Gamma-gamma coincidence performance of LaBr 3:Ce scintillation detectors vs HPGe detectors in high count-rate scenarios

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Drescher, A.; Yoho, M.; Landsberger, S.

    In this study, a radiation detection system consisting of two cerium doped lanthanum bromide (LaBr 3:Ce) scintillation detectors in a gamma-gamma coincidence configuration has been used to demonstrate the advantages that coincident detection provides relative to a single detector, and the advantages that LaBr 3:Ce detectors provide relative to high purity germanium (HPGe) detectors. Signal to noise ratios of select photopeak pairs for these detectors have been compared to high-purity germanium (HPGe) detectors in both single and coincident detector configurations in order to quantify the performance of each detector configuration. The efficiency and energy resolution of LaBr 3:Ce detectors havemore » been determined and compared to HPGe detectors. Coincident gamma-ray pairs from the radionuclides 152Eu and 133Ba have been identified in a sample that is dominated by 137Cs. Gamma-gamma coincidence successfully reduced the Compton continuum from the large 137Cs peak, revealed several coincident gamma energies characteristic of these nuclides, and improved the signal-to-noise ratio relative to single detector measurements. LaBr 3:Ce detectors performed at count rates multiple times higher than can be achieved with HPGe detectors. The standard background spectrum consisting of peaks associated with transitions within the LaBr 3:Ce crystal has also been significantly reduced. Finally, it is shown that LaBr 3:Ce detectors have the unique capability to perform gamma-gamma coincidence measurements in very high count rate scenarios, which can potentially benefit nuclear safeguards in situ measurements of spent nuclear fuel.« less

  14. A variable resolution x-ray detector for computed tomography: I. Theoretical basis and experimental verification.

    PubMed

    DiBianca, F A; Gupta, V; Zeman, H D

    2000-08-01

    A computed tomography imaging technique called variable resolution x-ray (VRX) detection provides detector resolution ranging from that of clinical body scanning to that of microscopy (1 cy/mm to 100 cy/mm). The VRX detection technique is based on a new principle denoted as "projective compression" that allows the detector resolution element to scale proportionally to the image field size. Two classes of VRX detector geometry are considered. Theoretical aspects related to x-ray physics and data sampling are presented. Measured resolution parameters (line-spread function and modulation-transfer function) are presented and discussed. A VRX image that resolves a pair of 50 micron tungsten hairs spaced 30 microns apart is shown.

  15. Spectrum sensing based on cumulative power spectral density

    NASA Astrophysics Data System (ADS)

    Nasser, A.; Mansour, A.; Yao, K. C.; Abdallah, H.; Charara, H.

    2017-12-01

    This paper presents new spectrum sensing algorithms based on the cumulative power spectral density (CPSD). The proposed detectors examine the CPSD of the received signal to make a decision on the absence/presence of the primary user (PU) signal. Those detectors require the whiteness of the noise in the band of interest. The false alarm and detection probabilities are derived analytically and simulated under Gaussian and Rayleigh fading channels. Our proposed detectors present better performance than the energy (ED) or the cyclostationary detectors (CSD). Moreover, in the presence of noise uncertainty (NU), they are shown to provide more robustness than ED, with less performance loss. In order to neglect the NU, we modified our algorithms to be independent from the noise variance.

  16. Surface Passivation of CdZnTe Detector by Hydrogen Peroxide Solution Etching

    NASA Technical Reports Server (NTRS)

    Hayes, M.; Chen, H.; Chattopadhyay, K.; Burger, A.; James, R. B.

    1998-01-01

    The spectral resolution of room temperature nuclear radiation detectors such as CdZnTe is usually limited by the presence of conducting surface species that increase the surface leakage current. Studies have shown that the leakage current can be reduced by proper surface preparation. In this study, we try to optimize the performance of CdZnTe detector by etching the detector with hydrogen peroxide solution as function of concentration and etching time. The passivation effect that hydrogen peroxide introduces have been investigated by current-voltage (I-V) measurement on both parallel strips and metal-semiconductor-metal configurations. The improvements on the spectral response of Fe-55 and 241Am due to hydrogen peroxide treatment are presented and discussed.

  17. BESST: A Miniature, Modular Radiometer

    NASA Technical Reports Server (NTRS)

    Warden, Robert; Good, William; Baldwin-Stevens, Erik

    2010-01-01

    A new radiometer assembly has been developed that incorporates modular design principles in order to provide flexibility and versatility. The assembly, shown in Figure 1, is made up of six modules plus a central cubical frame. A small thermal imaging detector is used to determine the temperature of remote objects. To improve the accuracy of the temperature reading, frequent calibration is required. The detector must view known temperature targets before viewing the remote object. Calibration is achieved by using a motorized fold mirror to select the desired scene the detector views. The motor steps the fold mirror through several positions, which allows the detector to view the calibration targets or the remote object. The details, features, and benefits of the radiometer are described in this paper.

  18. Quantum DOT IR Photodetectors

    DTIC Science & Technology

    2012-07-01

    transimpedance amplifier (CTIA), an output sample and hold, and a switched output buffer. Polaris Sensor Technology designed the unit cell that has this...hold, a dual gain, capacitive transimpedance amplifier (CTIA), an output sample and hold, and a switched output buffer. 6 The detector bias... transimpedance amplifier (CTIA) is used to integrate the detector’s photocurrent. It is built around a differential amplifier , X3, shown in Figure 3. The

  19. A history of hybrid pixel detectors, from high energy physics to medical imaging

    NASA Astrophysics Data System (ADS)

    Delpierre, P.

    2014-05-01

    The aim of this paper is to describe the development of hybrid pixel detectors from the origin to the application on medical imaging. We are going to recall the need for fast 2D detectors in the high energy physics experiments and to follow the different pixel electronic circuits created to satisfy this demand. The adaptation of these circuits for X-rays will be presented as well as their industrialization. Today, a number of applications are open for these cameras, particularly for biomedical imaging applications. Some developments for clinical CT will also be shown.

  20. Electron-Muon Identification by Atmospheric Shower and Electron Beam in a New EAS Detector Concept

    NASA Astrophysics Data System (ADS)

    Iori, M.; Denizli, H.; Yilmaz, A.; Ferrarotto, F.; Russ, J.

    2015-03-01

    We present results demonstrating the time resolution and μ/e separation capabilities of a new concept for an EAS detector capable of measuring cosmic rays arriving with large zenith angles. This kind of detector has been designed to be part of a large area (several square kilometer) surface array designed to measure ultra high energy (10-200 PeV) τ neutrinos using the Earth-skimming technique. A criterion to identify electron-gammas is also shown and the particle identification capability is tested by measurements in coincidence with the KASKADE-GRANDE experiment in Karlsruhe, Germany.

  1. Cosmic dosimetry using TLD aboard spacecrafts of the "Cosmos" series

    NASA Astrophysics Data System (ADS)

    Hübner, K.; Schmidt, P.; Fellinger, J.

    Thermoluminescent (TL) detectors were used for dosimetric investigations on the outer surface as well as inside Soviet spacecrafts of the "Cosmos" series. At the outer surface, ultrathin TL detectors, based on CaF 2-PTFE and LiF, were arranged in special stacks and exposed to unshielded cosmic radiation. The strong decrease of dose within a few mg/cm 2 demonstrates that weakly penetrating radiation is dominating in the radiation field under investigation. On the basis of glow curve analysis of LiF thermoluminescent detectors it could be shown, that the high doses are caused by electrons.

  2. Cosmic dosimetry using TLD aboard spacecrafts of the "Cosmos" series.

    PubMed

    Hubner, K; Schmidt, P; Fellinger, J

    1994-11-01

    Thermoluminescent (TL) detectors were used for dosimetric investigations on the outer surface as well as inside Soviet spacecrafts of the "Cosmos" series. At the outer surface, ultrathin TL detectors, based on CaF2-PTFE and LiF, were arranged in special stacks and exposed to unshielded cosmic radiation. The strong decrease of dose within a few mg/cm2 demonstrates that weakly penetrating radiation is dominating in the radiation field under investigation. On the basis of glow curve analysis of LiF thermoluminescent detectors it could be shown, that the high doses are caused by electrons.

  3. Enhancement of the resolution of full-field optical coherence tomography by using a colour image sensor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kalyanov, A L; Lychagov, V V; Smirnov, I V

    2013-08-31

    The influence of white balance in a colour image detector on the resolution of a full-field optical coherence tomograph (FFOCT) is studied. The change in the interference pulse width depending on the white balance tuning is estimated in the cases of a thermal radiation source (incandescent lamp) and a white light emitting diode. It is shown that by tuning white balance of the detector in a certain range, the FFOCT resolution can be increased by 20 % as compared to the resolution, attained with the use of a monochrome detector. (optical coherence tomography)

  4. Improvement of the energy resolution of pixelated CdTe detectors for applications in 0νββ searches

    NASA Astrophysics Data System (ADS)

    Gleixner, T.; Anton, G.; Filipenko, M.; Seller, P.; Veale, M. C.; Wilson, M. D.; Zang, A.; Michel, T.

    2015-07-01

    Experiments trying to detect 0νββ are very challenging. Their requirements include a good energy resolution and a good detection efficiency. With current fine pixelated CdTe detectors there is a trade off between the energy resolution and the detection efficiency, which limits their performance. It will be shown with simulations that this problem can be mostly negated by analysing the cathode signal which increases the optimal sensor thickness. We will compare different types of fine pixelated CdTe detectors (Timepix, Dosepix, HEXITEC) from this point of view.

  5. Doppler electron velocimetry : notes on creating a practical tool.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reu, Phillip L.; Milster, Tom

    2008-11-01

    The Doppler electron velocimeter (DEV) has been shown to be theoretically possible. This report attempts to answer the next logical question: Is it a practical instrument? The answer hinges upon whether enough electrons are available to create a time-varying Doppler current to be measured by a detector with enough sensitivity and bandwidth. The answer to both of these questions is a qualified yes. A target Doppler frequency of 1 MHz was set as a minimum rate of interest. At this target a theoretical beam current signal-to-noise ratio of 25-to-1 is shown for existing electron holography equipment. A detector is alsomore » demonstrated with a bandwidth of 1-MHz at a current of 10 pA. Additionally, a Linnik-type interferometer that would increase the available beam current is shown that would offer a more flexible arrangement for Doppler electron measurements over the traditional biprism.« less

  6. Quantification of the Conditioning Phase in Cooled Pixelated TlBr Detectors

    NASA Astrophysics Data System (ADS)

    Koehler, Will; He, Zhong; O'Neal, Sean; Yang, Hao; Kim, Hadong; Cirignano, Leonard; Shah, Kanai

    2015-08-01

    Thallium-bromide (TlBr) is currently under investigation as an alternative room-temperature semiconductor gamma-ray spectrometer due to its favorable material properties (large bandgap, high atomic numbers, and high density). Previous work has shown that 5 mm thick pixelated TlBr detectors can achieve sub-1% FWHM energy resolution at 662 keV for single-pixel events. These results are limited to - 20° C operation where detector performance is stable. During the first one to five days of applied bias at - 20° C, many TlBr detectors undergo a conditioning phase, where the energy resolution improves and the depth-dependent electron drift velocity stabilizes. In this work, the spectroscopic performance, drift velocity, and freed electron concentrations of multiple 5 mm thick pixelated TlBr detectors are monitored throughout the conditioning phase. Additionally, conditioning is performed twice on the same detector at different times to show that improvement mechanisms relax when the detector is stored without bias. We conclude that the improved spectroscopy results from internal electric field stabilization and uniformity caused by fewer trapped electrons.

  7. Design Improvements and X-Ray Performance of a Time Projection Chamber Polarimeter for Persistent Astronomical Sources

    NASA Technical Reports Server (NTRS)

    Hill, Joanne E.; Black, J. Kevin; Emmett, Thomas J.; Enoto, Teruaki; Jahoda, Keith M.; Kaaret, Philip; Nolan, David S.; Tamagawa, Toru

    2014-01-01

    The design of the Time-Projection Chamber (TPC) Polarimeter for the Gravity and Extreme Magnetism Small Explorer (GEMS) was demonstrated to Technology Readiness Level 6 (TRL-6)3 and the flight detectors fabricated, assembled and performance tested. A single flight detector was characterized at the Brookhaven National Laboratory Synchrotron Light Source with polarized X-rays at 10 energies from 2.3-8.0 keV at five detector positions. The detector met all of the GEMS performance requirements. Lifetime measurements have shown that the existing flight design has 23 years of lifetime4, opening up the possibility of relaxing material requirements, in particular the consideration of the use of epoxy, to reduce risk elsewhere. We report on design improvements to the GEMS detector to enable a narrower transfer gap that, when operated with a lower transfer field, reduces asymmetries in the detector response. In addition, the new design reduces cost and risk by simplifying the assembly and reducing production time. Finally, we report on the performance of the narrow-gap detector in response to polarized and unpolarized X-rays.

  8. Use of cylindrical diffusing fibers as detectors for interstitial tissue spectroscopy

    NASA Astrophysics Data System (ADS)

    Baran, Timothy M.; Foster, Thomas H.

    2015-03-01

    Interstitial photodynamic therapy (iPDT) describes the use of implanted optical fibers for delivery of treatment light to activate photosensitizer in regions that can be located deep within the body. Since sensitive healthy structures are often located nearby, this requires careful treatment planning that is dependent on tissue optical properties. Determination of these values usually involves the insertion of additional fibers into the volume, or the use of flat-cleaved optical fibers as both treatment sources and detectors. The insertion of additional fibers is undesirable, and cylindrical diffusers have been shown to offer superior treatment characteristics compared to flat-cleaved fibers. Using cylindrical diffusers as detectors for spectroscopic measurement is therefore attractive. We describe the determination of the detection profile for a particular cylindrical diffuser design and derive the scatterer concentration gradient within the diffuser core. This detection profile is compared to previously characterized diffusers, and is shown to be dependent on the diffuser design. For diffusers with a constant scatterer concentration and distal mirror, the detection profile is localized to the proximal end of the diffusing region. For diffusers with variable scattering concentration along their length and no distal mirror, the detection profile is shown to be more uniform along the diffusing region. We also present preliminary results showing the recovery of optical properties using arrays of cylindrical diffusing fibers as sources and detectors, with a mean error of 4.4% in the determination of μeff. The accuracy of these results is comparable to those obtained with other methods of optical property recovery.

  9. Hard x-ray response of a CdZnTe ring-drift detector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Owens, A.; Hartog, R. den; Quarati, F.

    We present the results of an experimental study of a special type of CdZnTe detector of hard x and {gamma} rays--A-drift detector. The device consists of a double ring electrode structure surrounding a central point anode with a guard plane surrounding the outer anode ring. The detector can be operated in two distinctively different modes of charge collection--pseudohemispherical and pseudodrift. We study the detector response profiles obtained by scanning the focused x-ray beam over the whole detector area, specifically the variations in count rate, peak position, and energy resolution for x rays from 10 to 100 keV. In addition, atmore » 662 keV the energy resolution was shown to be 4.8 keV, more than a factor of 2 better than for CdZnTe coplanar grid detectors. To interpret the experimental data, we derive an analytical expression for the spatial distribution of the electric field inside the detector and neglecting carrier diffusion, and identify carrier collection patterns for both modes of operation within the drift model approximation. We show that this model provides a good understanding of measured profiles.« less

  10. Thermal blinding of gated detectors in quantum cryptography.

    PubMed

    Lydersen, Lars; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes; Makarov, Vadim

    2010-12-20

    It has previously been shown that the gated detectors of two commercially available quantum key distribution (QKD) systems are blindable and controllable by an eavesdropper using continuous-wave illumination and short bright trigger pulses, manipulating voltages in the circuit [Nat. Photonics 4, 686 (2010)]. This allows for an attack eavesdropping the full raw and secret key without increasing the quantum bit error rate (QBER). Here we show how thermal effects in detectors under bright illumination can lead to the same outcome. We demonstrate that the detectors in a commercial QKD system Clavis2 can be blinded by heating the avalanche photo diodes (APDs) using bright illumination, so-called thermal blinding. Further, the detectors can be triggered using short bright pulses once they are blind. For systems with pauses between packet transmission such as the plug-and-play systems, thermal inertia enables Eve to apply the bright blinding illumination before eavesdropping, making her more difficult to catch.

  11. A sensitive gas chromatography detector based on atmospheric pressure chemical ionization by a dielectric barrier discharge.

    PubMed

    Kirk, Ansgar T; Last, Torben; Zimmermann, Stefan

    2017-02-03

    In this work, we present a novel concept for a gas chromatography detector utilizing an atmospheric pressure chemical ionization which is initialized by a dielectric barrier discharge. In general, such a detector can be simple and low-cost, while achieving extremely good limits of detection. However, it is non-selective apart from the use of chemical dopants. Here, a demonstrator manufactured entirely from fused silica capillaries and printed circuit boards is shown. It has a size of 75×60×25mm 3 and utilizes only 2W of power in total. Unlike other known discharge detectors, which require high-purity helium, this detector can theoretically be operated using any gas able to form stable ion species. Here, purified air is used. With this setup, limits of detection in the low parts-per-billion range have been obtained for acetone. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. High-energy X-ray diffraction using the Pixium 4700 flat-panel detector.

    PubMed

    Daniels, J E; Drakopoulos, M

    2009-07-01

    The Pixium 4700 detector represents a significant step forward in detector technology for high-energy X-ray diffraction. The detector design is based on digital flat-panel technology, combining an amorphous Si panel with a CsI scintillator. The detector has a useful pixel array of 1910 x 2480 pixels with a pixel size of 154 microm x 154 microm, and thus it covers an effective area of 294 mm x 379 mm. Designed for medical imaging, the detector has good efficiency at high X-ray energies. Furthermore, it is capable of acquiring sequences of images at 7.5 frames per second in full image mode, and up to 60 frames per second in binned region of interest modes. Here, the basic properties of this detector applied to high-energy X-ray diffraction are presented. Quantitative comparisons with a widespread high-energy detector, the MAR345 image plate scanner, are shown. Other properties of the Pixium 4700 detector, including a narrow point-spread function and distortion-free image, allows for the acquisition of high-quality diffraction data at high X-ray energies. In addition, high frame rates and shutterless operation open new experimental possibilities. Also provided are the necessary data for the correction of images collected using the Pixium 4700 for diffraction purposes.

  13. Possible explanation of the correlations between events recorded by underground detectors during the Supernova 1987A explosion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Alexeyev, E. N., E-mail: alexeyev@ms2.inr.ac.r

    A possible explanation of the time correlations between the data from underground detectors (Baksan telescope, LSD, IMB, Kamiokande II) and from the Rome and Maryland gravitational-wave antennas obtained during the Supernova 1987A explosion is proposed. It is shown that the synchronization of the events recorded by various underground facilities could be produced by gravitational radiation from the Supernova.

  14. Fast polarimetry of the colliding proton beams based on the elastic pp analyzer using the NICA detectors

    NASA Astrophysics Data System (ADS)

    Sharov, V. I.

    2017-12-01

    It is shown that the existing data on analyzing power An of the elastic pp scattering could be successfully applied for polarimetry of the colliding proton beams using the NICA detectors. Performed calculations of the count rates of the elastic events have revealed that the polarimeter based on using An for elastic pp will have a high polarization measurement velocity.

  15. Lead sulfide - Silicon MOSFET infrared focal plane development

    NASA Technical Reports Server (NTRS)

    Barrett, J. R.; Jhabvala, M. D.

    1983-01-01

    A process for directly integrating photoconductive lead sulfide (PbS) infrared detector material with silicon MOS integrated circuits has been developed primarily for application in long (greater than 10,000 detector elements) linear arrays for pushbroom scanning applications. The processing technology is based on the conventional PMOS and CMOS technologies with a variation in the metallization. Results and measurements on a fully integrated eight-element multiplexer are shown.

  16. Noncoherent detection of periodic signals

    NASA Technical Reports Server (NTRS)

    Gagliardi, R. M.

    1974-01-01

    The optimal Bayes detector for a general periodic waveform having uniform delay and additive white Gaussian noise is examined. It is shown that the detector is much more complex than that for the well known cases of pure sine waves (i.e. classical noncoherent detection) and narrowband signals. An interpretation of the optimal processing is presented, and several implementations are discussed. The results have application to the noncoherent detection of optical square waves.

  17. Color properties of the motion detectors projecting to the goldfish tectum: I. A color matching study.

    PubMed

    Maximov, Vadim; Maximova, Elena; Damjanović, Ilija; Maximov, Paul

    2014-09-01

    Responses of direction-selective and orientation-selective motion detectors were recorded extracellularly from the axon terminals of ganglion cells in the superficial layers of the tectum opticum of immobilized goldfish, Carassius gibelio (Bloch, 1782). Color stripes or edges moving on some color background (presented on the CRT monitor with known emission spectra of its phosphors) served as stimuli. It was shown that stimuli of any color can be more or less matched with the background by varying their intensities what is indicative of color blindness of the motion detectors. Sets of stimuli which matched the background proved to represent planes in the three-dimensional color space of the goldfish. A relative contribution of different types of cones to the spectral sensitivity was estimated according to orientation of the plane of color matches. The spectral sensitivity of any motion detector was shown to be determined mainly by long-wave cones with a weak negative (opponent) contributions of middle-wave and/or short-wave ones. This resulted in reduced sensitivity in the blue-green end of the spectrum, what may be considered as an adaptation to the aquatic environment where, because of the substantial light scattering of a blue-green light, acute vision is possible only in a red region of the spectrum.

  18. Polyethylene Naphthalate Scintillator: A Novel Detector for the Dosimetry of Radioactive Ophthalmic Applicators

    PubMed Central

    Flühs, Dirk; Flühs, Andrea; Ebenau, Melanie; Eichmann, Marion

    2015-01-01

    Background Dosimetric measurements in small radiation fields with large gradients, such as eye plaque dosimetry with β or low-energy photon emitters, require dosimetrically almost water-equivalent detectors with volumes of <1 mm3 and linear responses over several orders of magnitude. Polyvinyltoluene-based scintillators fulfil these conditions. Hence, they are a standard for such applications. However, they show disadvantages with regard to certain material properties and their dosimetric behaviour towards low-energy photons. Purpose, Materials and Methods Polyethylene naphthalate, recently recognized as a scintillator, offers chemical, physical and basic dosimetric properties superior to polyvinyltoluene. Its general applicability as a clinical dosimeter, however, has not been shown yet. To prove this applicability, extensive measurements at several clinical photon and electron radiation sources, ranging from ophthalmic plaques to a linear accelerator, were performed. Results For all radiation qualities under investigation, covering a wide range of dose rates, a linearity of the detector response to the dose was shown. Conclusion Polyethylene naphthalate proved to be a suitable detector material for the dosimetry of ophthalmic plaques, including low-energy photon emitters and other small radiation fields. Due to superior properties, it has the potential to replace polyvinyltoluene as the standard scintillator for such applications. PMID:27171681

  19. Real-time edge-enhanced optical correlator

    NASA Astrophysics Data System (ADS)

    Shihabi, Mazen M.; Hinedi, Sami M.; Shah, Biren N.

    1992-08-01

    The performance of five symbol lock detectors are compared. They are the square-law detector with overlapping (SQOD) and non-overlapping (SQNOD) integrators, the absolute value detectors with overlapping and non-overlapping (AVNOD) integrators and the signal power estimator detector (SPED). The analysis considers various scenarios when the observation interval is much larger or equal to the symbol synchronizer loop bandwidth, which has not been considered in previous analyses. Also, the case of threshold setting in the absence of signal is considered. It is shown that the SQOD outperforms all others when the threshold is set in the presence of signal, independent of the relationship between loop bandwidth and observation period. On the other hand, the SPED outperforms all others when the threshold is set in the presence of noise only.

  20. Real-time edge-enhanced optical correlator

    NASA Technical Reports Server (NTRS)

    Shihabi, Mazen M. (Inventor); Hinedi, Sami M. (Inventor); Shah, Biren N. (Inventor)

    1992-01-01

    The performance of five symbol lock detectors are compared. They are the square-law detector with overlapping (SQOD) and non-overlapping (SQNOD) integrators, the absolute value detectors with overlapping and non-overlapping (AVNOD) integrators and the signal power estimator detector (SPED). The analysis considers various scenarios when the observation interval is much larger or equal to the symbol synchronizer loop bandwidth, which has not been considered in previous analyses. Also, the case of threshold setting in the absence of signal is considered. It is shown that the SQOD outperforms all others when the threshold is set in the presence of signal, independent of the relationship between loop bandwidth and observation period. On the other hand, the SPED outperforms all others when the threshold is set in the presence of noise only.

  1. The Litho-Density tool calibration

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ellis, D.; Flaum, C.; Marienbach, E.

    1983-10-01

    The Litho-Density tool (LDT) uses a gamma ray source and two NaI scintillator detectors for borehole measurement of electron density, p/SUB e/, and a quantity, P/SUB e/, which is related to the photoelectric cross section at 60 keV and therefore to the lithology of the formation. An active stabilization system controls the gains of the two detectors which permits selective gamma-ray detection. Spectral analysis is performed in the near detector (2 energy windows) and in the detector farther away from the source (3 energy windows). This paper describes the results of laboratory measurements undertaken to define the basic tool response.more » The tool is shown to provide reliable measurements of formation density and lithology under a variety of environmental conditions.« less

  2. Development of multi-layer crystal detector and related front end electronics

    NASA Astrophysics Data System (ADS)

    Cardarelli, R.; Di Ciaccio, A.; Paolozzi, L.

    2014-05-01

    A crystal (diamond) particle detector has been developed and tested, whose constitute elements are a multi-layer polycrystalline diamond and a pick-up system capable of collecting in parallel the charge produced in the layers. The charge is read with a charge-to-voltage amplifier (5-6 mV/fC) realized with bipolar junction transistors in order to minimize the effect of the detector capacitance. The tests performed with cosmic rays and at the beam test facility of Frascati with 500 MeV electrons in single electron mode operation have shown that a detector with 4-5 layers of 250 μm thickness each and 9 mm2 active area exhibits an upper limit of 150 ps time resolution for minimum ionizing particles at an operating voltage of about 350 V.

  3. Resonant dampers for parametric instabilities in gravitational wave detectors

    NASA Astrophysics Data System (ADS)

    Gras, S.; Fritschel, P.; Barsotti, L.; Evans, M.

    2015-10-01

    Advanced gravitational wave interferometric detectors will operate at their design sensitivity with nearly ˜1 MW of laser power stored in the arm cavities. Such large power may lead to the uncontrolled growth of acoustic modes in the test masses due to the transfer of optical energy to the mechanical modes of the arm cavity mirrors. These parametric instabilities have the potential to significantly compromise the detector performance and control. Here we present the design of "acoustic mode dampers" that use the piezoelectric effect to reduce the coupling of optical to mechanical energy. Experimental measurements carried on an Advanced LIGO-like test mass have shown a tenfold reduction in the amplitude of several mechanical modes, thus suggesting that this technique can greatly mitigate the impact of parametric instabilities in advanced detectors.

  4. Background in X-ray astronomy proportional counters

    NASA Technical Reports Server (NTRS)

    Bower, C. R.; Dietz, K. L.; Ramsey, B. D.; Weisskopf, M. C.

    1991-01-01

    The authors report the results of an investigation into the nature of background events in proportional counters sensitive to X-ray photons having energy of less than 150 keV. Even with the use of thick shields composed of high-atomic-number material, a significant flux background in the detector's energy region can result from multiple Compton scattering in the mass surrounding the active region of the detector. The importance of the selection of detector components in the reduction of the background by more than an order of magnitude is emphasized. Experimental results are shown to agree qualitatively with Monte Carlo simulations. It is concluded that escape gating is a powerful means of determining the nature of background in flight detectors: the single/pair ratios reveal whether the detected events are charged particles or photons.

  5. SU-F-BRE-01: A Rapid Method to Determine An Upper Limit On a Radiation Detector's Correction Factor During the QA of IMRT Plans

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kamio, Y; Bouchard, H

    2014-06-15

    Purpose: Discrepancies in the verification of the absorbed dose to water from an IMRT plan using a radiation dosimeter can be wither caused by 1) detector specific nonstandard field correction factors as described by the formalism of Alfonso et al. 2) inaccurate delivery of the DQA plan. The aim of this work is to develop a simple/fast method to determine an upper limit on the contribution of composite field correction factors to these discrepancies. Methods: Indices that characterize the non-flatness of the symmetrised collapsed delivery (VSC) of IMRT fields over detector-specific regions of interest were shown to be correlated withmore » IMRT field correction factors. The indices introduced are the uniformity index (UI) and the mean fluctuation index (MF). Each one of these correlation plots have 10 000 fields generated with a stochastic model. A total of eight radiation detectors were investigated in the radial orientation. An upper bound on the correction factors was evaluated by fitting values of high correction factors for a given index value. Results: These fitted curves can be used to compare the performance of radiation dosimeters in composite IMRT fields. Highly water-equivalent dosimeters like the scintillating detector (Exradin W1) and a generic alanine detector have been found to have corrections under 1% over a broad range of field modulations (0 – 0.12 for MF and 0 – 0.5 for UI). Other detectors have been shown to have corrections of a few percent over this range. Finally, a full Monte Carlo simulations of 18 clinical and nonclinical IMRT field showed good agreement with the fitted curve for the A12 ionization chamber. Conclusion: This work proposes a rapid method to evaluate an upper bound on the contribution of correction factors to discrepancies found in the verification of DQA plans.« less

  6. Signal to noise ratio of energy selective x-ray photon counting systems with pileup.

    PubMed

    Alvarez, Robert E

    2014-11-01

    To derive fundamental limits on the effect of pulse pileup and quantum noise in photon counting detectors on the signal to noise ratio (SNR) and noise variance of energy selective x-ray imaging systems. An idealized model of the response of counting detectors to pulse pileup is used. The model assumes a nonparalyzable response and delta function pulse shape. The model is used to derive analytical formulas for the noise and energy spectrum of the recorded photons with pulse pileup. These formulas are first verified with a Monte Carlo simulation. They are then used with a method introduced in a previous paper [R. E. Alvarez, "Near optimal energy selective x-ray imaging system performance with simple detectors," Med. Phys. 37, 822-841 (2010)] to compare the signal to noise ratio with pileup to the ideal SNR with perfect energy resolution. Detectors studied include photon counting detectors with pulse height analysis (PHA), detectors that simultaneously measure the number of photons and the integrated energy (NQ detector), and conventional energy integrating and photon counting detectors. The increase in the A-vector variance with dead time is also computed and compared to the Monte Carlo results. A formula for the covariance of the NQ detector is developed. The validity of the constant covariance approximation to the Cramèr-Rao lower bound (CRLB) for larger counts is tested. The SNR becomes smaller than the conventional energy integrating detector (Q) SNR for 0.52, 0.65, and 0.78 expected number photons per dead time for counting (N), two, and four bin PHA detectors, respectively. The NQ detector SNR is always larger than the N and Q SNR but only marginally so for larger dead times. Its noise variance increases by a factor of approximately 3 and 5 for the A1 and A2 components as the dead time parameter increases from 0 to 0.8 photons per dead time. With four bin PHA data, the increase in variance is approximately 2 and 4 times. The constant covariance approximation to the CRLB is valid for larger counts such as those used in medical imaging. The SNR decreases rapidly as dead time increases. This decrease places stringent limits on allowable dead times with the high count rates required for medical imaging systems. The probability distribution of the idealized data with pileup is shown to be accurately described as a multivariate normal for expected counts greater than those typically utilized in medical imaging systems. The constant covariance approximation to the CRLB is also shown to be valid in this case. A new formula for the covariance of the NQ detector with pileup is derived and validated.

  7. Signal to noise ratio of energy selective x-ray photon counting systems with pileup

    PubMed Central

    Alvarez, Robert E.

    2014-01-01

    Purpose: To derive fundamental limits on the effect of pulse pileup and quantum noise in photon counting detectors on the signal to noise ratio (SNR) and noise variance of energy selective x-ray imaging systems. Methods: An idealized model of the response of counting detectors to pulse pileup is used. The model assumes a nonparalyzable response and delta function pulse shape. The model is used to derive analytical formulas for the noise and energy spectrum of the recorded photons with pulse pileup. These formulas are first verified with a Monte Carlo simulation. They are then used with a method introduced in a previous paper [R. E. Alvarez, “Near optimal energy selective x-ray imaging system performance with simple detectors,” Med. Phys. 37, 822–841 (2010)] to compare the signal to noise ratio with pileup to the ideal SNR with perfect energy resolution. Detectors studied include photon counting detectors with pulse height analysis (PHA), detectors that simultaneously measure the number of photons and the integrated energy (NQ detector), and conventional energy integrating and photon counting detectors. The increase in the A-vector variance with dead time is also computed and compared to the Monte Carlo results. A formula for the covariance of the NQ detector is developed. The validity of the constant covariance approximation to the Cramèr–Rao lower bound (CRLB) for larger counts is tested. Results: The SNR becomes smaller than the conventional energy integrating detector (Q) SNR for 0.52, 0.65, and 0.78 expected number photons per dead time for counting (N), two, and four bin PHA detectors, respectively. The NQ detector SNR is always larger than the N and Q SNR but only marginally so for larger dead times. Its noise variance increases by a factor of approximately 3 and 5 for the A1 and A2 components as the dead time parameter increases from 0 to 0.8 photons per dead time. With four bin PHA data, the increase in variance is approximately 2 and 4 times. The constant covariance approximation to the CRLB is valid for larger counts such as those used in medical imaging. Conclusions: The SNR decreases rapidly as dead time increases. This decrease places stringent limits on allowable dead times with the high count rates required for medical imaging systems. The probability distribution of the idealized data with pileup is shown to be accurately described as a multivariate normal for expected counts greater than those typically utilized in medical imaging systems. The constant covariance approximation to the CRLB is also shown to be valid in this case. A new formula for the covariance of the NQ detector with pileup is derived and validated. PMID:25370642

  8. NbN single-photon detectors with saturated dependence of quantum efficiency

    NASA Astrophysics Data System (ADS)

    Smirnov, Konstantin; Divochiy, Alexander; Vakhtomin, Yury; Morozov, Pavel; Zolotov, Philipp; Antipov, Andrey; Seleznev, Vitaliy

    2018-07-01

    The possibility of creating NbN superconducting single-photon detectors with saturated dependence of quantum efficiency (QE) versus normalized bias current was investigated. It was shown that the saturation increases for the detectors based on finer films with a lower value of R s300/R s20. The decreasing of R s300/R s20 was related to the increasing influence of quantum corrections to conductivity of superconductors and, in turn, to the decrease of the electron diffusion coefficient. The best samples have a constant value of system QE 94% at I b /I c ∼ 0.8 and wavelength 1310 nm.

  9. Foil cycling technique for the VESUVIO spectrometer operating in the resonance detector configuration

    NASA Astrophysics Data System (ADS)

    Schooneveld, E. M.; Mayers, J.; Rhodes, N. J.; Pietropaolo, A.; Andreani, C.; Senesi, R.; Gorini, G.; Perelli-Cippo, E.; Tardocchi, M.

    2006-09-01

    This article reports a novel experimental technique, namely, the foil cycling technique, developed on the VESUVIO spectrometer (ISIS spallation source) operating in the resonance detector configuration. It is shown that with a proper use of two foils of the same neutron absorbing material it is possible, in a double energy analysis process, to narrow the width of the instrumental resolution of a spectrometer operating in the resonance detector configuration and to achieve an effective subtraction of the neutron and gamma backgrounds. Preliminary experimental results, obtained from deep inelastic neutron scattering measurements on lead, zirconium hydride, and deuterium chloride samples, are presented.

  10. Microchannel plate EUV detectors for the Extreme Ultraviolet Explorer

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Malina, R. F.; Coburn, K.; Werthimer, D.

    1984-01-01

    The design and operating characteristics of the prototype imaging microchannel plate (MCP) detector for the Extreme Ultraviolet Explorer (EUVE) Satellite are discussed. It is shown that this detector has achieved high position resolution performance (greater than 512 x 512 pixels) and has low (less than one percent) image distortion. In addition, the channel plate scheme used has tight pulse height distributions (less than 40 percent FWHM) for UV radiation and displays low (less than 0.2 cnt/sq cm-s) dark background counting rates. Work that has been done on EUV filters in relation to the envisaged filter and photocathode complement is also described.

  11. Detector response function of an energy-resolved CdTe single photon counting detector.

    PubMed

    Liu, Xin; Lee, Hyoung Koo

    2014-01-01

    While spectral CT using single photon counting detector has shown a number of advantages in diagnostic imaging, knowledge of the detector response function of an energy-resolved detector is needed to correct the signal bias and reconstruct the image more accurately. The objective of this paper is to study the photo counting detector response function using laboratory sources, and investigate the signal bias correction method. Our approach is to model the detector response function over the entire diagnostic energy range (20 keV

  12. Measurements of output factors with different detector types and Monte Carlo calculations of stopping-power ratios for degraded electron beams.

    PubMed

    Björk, Peter; Knöös, Tommy; Nilsson, Per

    2004-10-07

    The aim of the present study was to investigate three different detector types (a parallel-plate ionization chamber, a p-type silicon diode and a diamond detector) with regard to output factor measurements in degraded electron beams, such as those encountered in small-electron-field radiotherapy and intraoperative radiation therapy (IORT). The Monte Carlo method was used to calculate mass collision stopping-power ratios between water and the different detector materials for these complex electron beams (nominal energies of 6, 12 and 20 MeV). The diamond detector was shown to exhibit excellent properties for output factor measurements in degraded beams and was therefore used as a reference. The diode detector was found to be well suited for practical measurements of output factors, although the water-to-silicon stopping-power ratio was shown to vary slightly with treatment set-up and irradiation depth (especially for lower electron energies). Application of ionization-chamber-based dosimetry, according to international dosimetry protocols, will introduce uncertainties smaller than 0.3% into the output factor determination for conventional IORT beams if the variation of the water-to-air stopping-power ratio is not taken into account. The IORT system at our department includes a 0.3 cm thin plastic scatterer inside the therapeutic beam, which furthermore increases the energy degradation of the electrons. By ignoring the change in the water-to-air stopping-power ratio due to this scatterer, the output factor could be underestimated by up to 1.3%. This was verified by the measurements. In small-electron-beam dosimetry, the water-to-air stopping-power ratio variation with field size could mostly be ignored. For fields with flat lateral dose profiles (>3 x 3 cm2), output factors determined with the ionization chamber were found to be in close agreement with the results of the diamond detector. For smaller field sizes the lateral extension of the ionization chamber hampers its use. We therefore recommend that the readily available silicon diode detector should be used for output factor measurements in complex electron fields.

  13. A New Sensor Based Upon a Rotating-Coil Electromagnetic Induction Concept

    DTIC Science & Technology

    2006-12-01

    of determining the transmitter coil position. The position must be known to produce a reference signal for the synchronous detector described in...schematically shown in Figure 14.3 Figure 14. Block diagram of the lock-in amplifier. This AC to DC conversion is performed by a phase- sensitive ... detector (PSD). It rectifies only the signal of interest while suppressing the noise or interfering signal components that may accompany the signal. To

  14. Signal-to-noise limitations in white light holography

    NASA Technical Reports Server (NTRS)

    Ribak, Erez; Breckinridge, James B.; Roddier, Claude; Roddier, Francois

    1988-01-01

    A simple derivation is given for the SNR in images reconstructed from incoherent holograms. Dependence is shown to be on the hologram SNR, object complexity, and the number of pixels in the detector. Reconstruction of involved objects becomes possible with high-dynamic-range detectors such as CCDs. White-light holograms have been produced by means of a rotational shear interferometer combined with a chromatic corrector. A digital inverse transform recreated the object.

  15. Long-term room temperature stability of TlBr gamma detectors

    NASA Astrophysics Data System (ADS)

    Conway, A. M.; Voss, L. F.; Nelson, A. J.; Beck, P. R.; Graff, R. T.; Nikolic, R. J.; Payne, S. A.; Kim, H.; Cirignano, L. J.; Shah, K.

    2011-09-01

    TlBr is a material of interest for use in room temperature gamma ray detector applications due to is wide bandgap 2.7 eV and high average atomic number (Tl 81, Br 35). Researchers have achieved energy resolutions of 1.3 % at 662 keV, demonstrating the potential of this material system. However, these detectors are known to polarize using conventional configurations, limiting their use. Continued improvement of room temperature, high-resolution gamma ray detectors based on TlBr requires further understanding of the degradation mechanisms. While high quality material is a critical starting point for excellent detector performance, we show that the room temperature stability of planar TlBr gamma spectrometers can be significantly enhanced by treatment with both hydrofluoric and hydrochloric acid. By incorporating F or Cl into the surface of TlBr, current instabilities are eliminated and the longer term current of the detectors remains unchanged. 241Am spectra are also shown to be more stable for extended periods; detectors have been held at 2000 V/cm for 52 days with less than 10% degradation in peak centroid position. In addition, evidence for the long term degradation mechanism being related to the contact metal is presented.

  16. New target and detection methods: active detectors

    NASA Astrophysics Data System (ADS)

    Mittig, W.; Savajols, H.; Demonchy, C. E.; Giot, L.; Roussel-Chomaz, P.; Wang, H.; Ter-Akopian, G.; Fomichev, A.; Golovkov, M. S.; Stepansov, S.; Wolski, R.; Alamanos, N.; Drouart, A.; Gillibert, A.; Lapoux, V.; Pollacco, E.

    2003-07-01

    The study of nuclei far from stability interacting with simple target nuclei, such as protons, deuterons, 3He and 4He implies the use of inverse kinematics. The very special kinematics, together with the low intensities of the beams calls for special techniques. In july 2002 we tested a new detector, in which the detector gas is the target. This allows in principle a 4π solid angle of the detection, and a big effective target thickness without loss of resolution. The detector developped, called Maya, used isobuthane C4H10 as gas in present tests, and other gases are possible. The multiplexed electronics of more than 1000channels allows the reconstruction of the events occuring between the incoming particle and the detector gas atoms in 3D. Here we were interested in the elastic scattering of 8He on protons for the study of the isobaric analogue states (IAS) of 9He. The beam, in this case, is stopped in the detector. The resonance energy is determined by the place of interaction and the energy of the recoiling proton. The design of the detector is shown, together with some preliminary results are discussed.

  17. Development of a high-resolution liquid xenon detector for gamma-ray astrophysics

    NASA Astrophysics Data System (ADS)

    Mukherjee, Reshmi

    It has been shown here that liquid xenon is one of the most promising detector media for future gamma-ray detectors, owing to an excellent combination of physical properties. The feasibility of the construction of a high resolution liquid xenon detector as a gamma-ray detector for astrophysics has been demonstrated. Up to 3.5 liters of liquid xenon has been successfully purified and using both small and large volume prototypes, the charge and the energy resolution response of such detectors to gamma-rays, internal conversion electrons and alpha particles have been measured. The best energy resolution measured was 4.5 percent FWHM at 1 MeV. Cosmic ray tracks have been imaged using a 2-dimensional liquid xenon multiwire imaging chamber. The spatial resolution along the direction of the drifting electrons was 180 microns rms. Experiments have been performed to study the scintillation light in liquid xenon, as the prompt scintillation signal in the liquid is an electron-ion pair in liquid krypton was measured for the first time with a pulsed ionization chamber to be 18.4 plus or minus 0.3 eV.

  18. Enhanced numerical analysis of three-color HgCdTe detectors

    NASA Astrophysics Data System (ADS)

    Jóźwikowski, K.; Rogalski, A.

    2007-04-01

    The performance of three-color HgCdTe photovoltaic heterostructure detector is examined theoretically. In comparison with two-color detectors with two back-to-back junctions, three-color structure contain an absorber of intermediate wavelength placed between two junctions, and electronic barriers are used to isolate this intermediate region. This structure was first proposed by British workers. Enhanced original computer programs are applied to solve the system of non-linear continuity equations for carriers and Poisson equations. In addition, the numerical analysis includes the dependence of absorption coefficient on Burstein effect as well as interference effects in heterostructure with metallic electrical contacts. Three detector structures with different localizations of separating barriers are analyzed. The calculations results are presented in the form of spatial distributions of bandgap energy and quantum efficiency. It is shown that the performance of the detector is critically dependent on the barrier's doping level and position in relation to the junction. This behavior is serious disadvantage of the considered three color detector. A small shift of the barrier location and doping level causes serious changes in spectral responsivity.

  19. Numerical analysis of three-colour HgCdTe detectors

    NASA Astrophysics Data System (ADS)

    Jóźwikowski, K.; Rogalski, A.

    2007-12-01

    The performance of three-colour HgCdTe photovoltaic heterostructure detector is examined theoretically. In comparison with two-colour detectors with two back-to-back junctions, three-colour structure contains an absorber of intermediate wavelength placed between two junctions and electronic barriers are used to isolate this intermediate region. This structure was first proposed by British workers. Three-detector structures with different localizations of separating barriers are analyzed. The calculation results are presented in the form of spatial distributions of bandgap energy and quantum efficiency. Enhanced original computer programs are applied to solve the system of non-linear continuity equations for carriers and Poisson equations. In addition, the numerical analysis includes the dependence of absorption coefficient on Burstein effect as well as interference effects in heterostructure with metallic electrical contacts. It is shown that the performance of the detector is critically dependent on the barrier’s doping level and position in relation to the junction. This behaviour is serious disadvantage of the considered three-colour detector. A small shift of the barrier location and doping level causes serious changes in spectral responsivity.

  20. Simulation study of a geometric shape factor technique for estimating earth-emitted radiant flux densities from wide-field-of-view radiation measurements

    NASA Technical Reports Server (NTRS)

    Weaver, W. L.; Green, R. N.

    1980-01-01

    Geometric shape factors were computed and applied to satellite simulated irradiance measurements to estimate Earth emitted flux densities for global and zonal scales and for areas smaller than the detector field of view (FOV). Wide field of view flat plate detectors were emphasized, but spherical detectors were also studied. The radiation field was modeled after data from the Nimbus 2 and 3 satellites. At a satellite altitude of 600 km, zonal estimates were in error 1.0 to 1.2 percent and global estimates were in error less than 0.2 percent. Estimates with unrestricted field of view (UFOV) detectors were about the same for Lambertian and limb darkening radiation models. The opposite was found for restricted field of view detectors. The UFOV detectors are found to be poor estimators of flux density from the total FOV and are shown to be much better as estimators of flux density from a circle centered at the FOV with an area significantly smaller than that for the total FOV.

  1. Design and Construction of Detector and Data Acquisition Elements for Proton Computed Tomography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fermi Research Alliance; Northern Illinois University

    2015-07-15

    Proton computed tomography (pCT) offers an alternative to x-ray imaging with potential for three-dimensional imaging, reduced radiation exposure, and in-situ imaging. Northern Illinois University (NIU) is developing a second-generation proton computed tomography system with a goal of demonstrating the feasibility of three-dimensional imaging within clinically realistic imaging times. The second-generation pCT system is comprised of a tracking system, a calorimeter, data acquisition, a computing farm, and software algorithms. The proton beam encounters the upstream tracking detectors, the patient or phantom, the downstream tracking detectors, and a calorimeter. The schematic layout of the PCT system is shown. The data acquisition sendsmore » the proton scattering information to an offline computing farm. Major innovations of the second generation pCT project involve an increased data acquisition rate ( MHz range) and development of three-dimensional imaging algorithms. The Fermilab Particle Physics Division and Northern Illinois Center for Accelerator and Detector Development at Northern Illinois University worked together to design and construct the tracking detectors, calorimeter, readout electronics and detector mounting system.« less

  2. Reversible rigid coupling apparatus and method for borehole seismic transducers

    DOEpatents

    Owen, Thomas E.; Parra, Jorge O.

    1992-01-01

    An apparatus and method of high resolution reverse vertical seismic profile (VSP) measurements is shown. By encapsulating the seismic detector and heaters in a meltable substance (such as wax), the seismic detector can be removably secured in a borehole in a manner capable of measuring high resolution signals in the 100 to 1000 hertz range and higher. The meltable substance is selected to match the overall density of the detector package with the underground formation, yet still have relatively low melting point and rigid enough to transmit vibrations to accelerometers in the seismic detector. To minimize voids in the meltable substance upon solidification, the meltable substance is selected for minimum shrinkage, yet still having the other desirable characteristics. Heaters are arranged in the meltable substance in such a manner to allow the lowermost portion of the meltable substance to cool and solidify first. Solidification continues upwards from bottom-to-top until the top of the meltable substance is solidified and the seismic detector is ready for use. To remove, the heaters melt the meltable substance and the detector package is pulled from the borehole.

  3. Polycrystalline CdTe detectors: A luminosity monitor for the LHC

    NASA Astrophysics Data System (ADS)

    Gschwendtner, E.; Placidia, M.; Schmicklera, H.

    2003-09-01

    The luminosity at the four interaction points of the Large Hadron Collider must be continuously monitored in order to provide an adequate tool for the control and optimization of the collision parameters and the beam optics. At both sides of the interaction points absorbers are installed to protect the super-conducting accelerator elements from quenches caused by the deposited energy of collision products. The luminosity detectors will be installed in the copper core of these absorbers to measure the electromagnetic and hadronic showers caused by neutral particles that are produced at the proton-proton collision in the interaction points. The detectors have to withstand extreme radiation levels (108 Gy/yr at the design luminosity) and their long-term operation has to be assured without requiring human intervention. In addition the demand for bunch-by-bunch luminosity measurements, i.e. 40 MHz detection speed, puts severe constraints on the detectors. Polycrystalline CdTe detectors have a high potential to fulfill the requirements and are considered as LHC luminosity monitors. In this paper the interaction region is shown and the characteristics of the CdTe detectors are presented.

  4. Qualification and calibration tests of detector modules for the CMS Pixel Phase 1 upgrade

    NASA Astrophysics Data System (ADS)

    Zhu, D.; Backhaus, M.; Berger, P.; Meinhard, M.; Starodumov, A.; Tavolaro, V.

    2018-01-01

    In high energy particle physics, accelerator- and detector-upgrades always go hand in hand. The instantaneous luminosity of the Large Hadron Collider will increase to up to L = 2×1034cm-2s-1 during Run 2 until 2023. In order to cope with such luminosities, the pixel detector of the CMS experiment has been replaced early 2017. The so-called CMS Pixel phase 1 upgrade detector consists of 1184 modules with new design. An important production step is the module qualification and calibration, ensuring their proper functionality within the detector. This paper summarizes the qualification and calibration tests and results of modules used in the innermost two detector layers with focus on methods using module-internal calibration signals. Extended characterizations on pixel level such as electronic noise and bump bond connectivity, optimization of operational parameters, sensor quality and thermal stress resistance were performed using a customized setup with controlled environment. It could be shown that the selected modules have on average 0.55‰ ± 0.01‰ defective pixels and that all performance parameters stay within their specifications.

  5. Topological detector: measuring continuous dosimetric quantities with few-element detector array.

    PubMed

    Han, Zhaohui; Brivio, Davide; Sajo, Erno; Zygmanski, Piotr

    2016-08-21

    A prototype topological detector was fabricated and investigated for quality assurance of radiation producing medical devices. Unlike a typical array or flat panel detector, a topological detector, while capable of achieving a very high spatial resolution, consists of only a few elements and therefore is much simpler in construction and more cost effective. The key feature allowing this advancement is a geometry-driven design that is customized for a specific dosimetric application. In the current work, a topological detector of two elements was examined for the positioning verification of the radiation collimating devices (jaws, MLCs, and blades etc). The detector was diagonally segmented from a rectangular thin film strip (2.5 cm  ×  15 cm), giving two contiguous but independent detector elements. The segmented area was the central portion of the strip measuring 5 cm in length. Under irradiation, signals from each detector element were separately digitized using a commercial multichannel data acquisition system. The center and size of an x-ray field, which were uniquely determined by the collimator positions, were shown mathematically to relate to the difference and sum of the two signals. As a proof of concept, experiments were carried out using slit x-ray fields ranging from 2 mm to 20 mm in size. It was demonstrated that, the collimator positions can be accurately measured with sub-millimeter precisions.

  6. Advances in Neutron Spectroscopy with Deuterated Organic Scintillators

    NASA Astrophysics Data System (ADS)

    Febbraro, Michael; Pain, Steve; Becchetti, Frederick

    2015-10-01

    Deuterated organic scintillators have shown promise as neutron detectors for nuclear science as well as applications in nuclear non-proliferation and safeguards. In particular, they can extract neutron spectra without the use of neutron time-of-flight measurement (n-ToF) utilizing spectrum unfolding techniques. This permits the measure of cross sections of bound and unbound states with high efficiency and angular coverage. In the case of measurements with radioactive ion beams where low beam intensities limit long path n-ToF, short path n-ToF can be used to discriminate neutrons of interest from room return and background neutrons. This presentation will provide recent advances with these types of detectors. Digital pulse-shape discrimination using fast waveform digitizers, spectrum unfolding methods for extraction of neutron spectra, and a new safer deuterated-xylene formulation EJ-301D will be discussed. In addition, experimental results from measurements of discrete and continuous neutron spectra which illustrate the advantage of these detectors for certain applications in nuclear physics research and nuclear security will be shown. This work is supported by NSF and DOE.

  7. Silicon Drift Detectors - A Novel Technology for Vertex Detectors

    NASA Astrophysics Data System (ADS)

    Lynn, D.

    1996-10-01

    Silicon Drift Detectors (SDD) are novel position sensing silicon detectors which operate in a manner analogous to gas drift detectors. Single SDD's were shown in the CERN NA45 experiment to permit excellent spatial resolution (< 10 μm), to handle large particle occupancy, and to require a small fraction of the number of electronic channels of an equivalent pixel detector. The Silicon Vertex Tracker (SVT) for the STAR experiment at RHIC is based on this new technology. The SVT will consist of 216 SDD's, each 6.3 cm by 6.3 cm, arranged in a three layer barrel design, covering 2 π in azimuth and ±1 in pseudo-rapidity. Over the last three years we undertook a concentrated R+D effort to optimize the performance of the detector by minimizing the inactive area, the operating voltage and the data volume. We will present test results from several wafer prototypes. The charge produced by the passage of ionizing particles through the bulk of the detectors is collected on segmented anodes, with a pitch of 250 μm, on the far edges of the detector. The anodes are wire-bonded to a thick film multi-chip module which contains preamplifier/shaper chips and CMOS based switched capacitor arrays used as an analog memory pipeline. The ADC is located off-detector. The complete readout chain from the wafer to the DAQ will be presented. Finally we will show physics performance simulations based on the resolution achieved by the SVT prototypes.

  8. Using MASHA+TIMEPIX Setup for Registration Beta Decay Isotopes Produced in Heavy Ion Induced Reactions

    NASA Astrophysics Data System (ADS)

    Rodin, A. M.; Belozerov, A. V.; Chernysheva, E. V.; Dmitriev, S. N.; Gulyaev, A. V.; Gulyaeva, A. V.; Itkis, M. G.; Novoselov, A. S.; Oganessian, Yu. Ts.; Salamatin, V. S.; Stepantsov, S. V.; Vedeneev, V. Yu.; Yukhimchuk, S. A.; Krupa, L.; Granja, C.; Pospisil, S.; Kliman, J.; Motycak, S.; Sivacek, I.

    2015-06-01

    Radon and mercury isotopes were produced in multi nucleon transfer (48Ca + 232Th) and complete fusion (48Ca + naturalNd) reactions, respectively. The isotopes with given masses were detected using two detectors: a multi-strip detector of the well-type (made in CANBERRA) and a position-sensitive quantum counting hybrid pixel detector of the TIMEPIX type. The isotopes implanted into the detectors then emit alpha- and betaparticles until reaching the long lived isotopes. The position of the isotopes, the tracks, the time and energy of beta-particles were measured and analyzed. A new software for the particle recognition and data analysis of experimental results was developed and used. It was shown that MASHA+ TIMEPIX setup is a powerful instrument for investigation of neutron-rich isotopes far from stability limits.

  9. Understanding the detector behavior through Montecarlo and calibration studies in view of the SOX measurement

    NASA Astrophysics Data System (ADS)

    Caminata, A.; Agostini, M.; Altenmüller, K.; Appel, S.; Bellini, G.; Benziger, J.; Berton, N.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Cavalcante, P.; Chepurnov, A.; Choi, K.; Cribier, M.; D'Angelo, D.; Davini, S.; Derbin, A.; Di Noto, L.; Drachnev, I.; Durero, M.; Empl, A.; Etenko, A.; Farinon, S.; Fischer, V.; Fomenko, K.; Franco, D.; Gabriele, F.; Gaffiot, J.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Houdy, T.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jonquères, N.; Jedrzejczak, K.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kornoukhov, V.; Kryn, D.; Lachenmaier, T.; Lasserre, T.; Laubenstein, M.; Lehnert, B.; Link, J.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Maricic, J.; Mention, G.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Musenich, R.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, N.; Schönert, S.; Scola, L.; Semenov, D.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Unzhakov, E.; Veyssiere, C.; Vishneva, A.; Vivier, M.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2016-02-01

    Borexino is an unsegmented neutrino detector operating at LNGS in central Italy. The experiment has shown its performances through its unprecedented accomplishments in the solar and geoneutrino detection. These performances make it an ideal tool to accomplish a state- of-the-art experiment able to test the existence of sterile neutrinos (SOX experiment). For both the solar and the SOX analysis, a good understanding of the detector response is fundamental. Consequently, calibration campaigns with radioactive sources have been performed over the years. The calibration data are of extreme importance to develop an accurate Monte Carlo code. This code is used in all the neutrino analyses. The Borexino-SOX calibration techniques and program and the advances on the detector simulation code in view of the start of the SOX data taking are presented. 1

  10. Cryogenic Microcalorimeter System for Ultra-High Resolution Alpha-Particle Spectrometry

    NASA Astrophysics Data System (ADS)

    Croce, M. P.; Bacrania, M. K.; Hoover, A. S.; Rabin, M. W.; Hoteling, N. J.; LaMont, S. P.; Plionis, A. A.; Dry, D. E.; Ullom, J. N.; Bennett, D. A.; Horansky, R. D.; Kotsubo, V.; Cantor, R.

    2009-12-01

    Microcalorimeters have been shown to yield unsurpassed energy resolution for alpha spectrometry, up to 1.06 keV FWHM at 5.3 MeV. These detectors use a superconducting transition-edge sensor (TES) to measure the temperature change in an absorber from energy deposited by an interacting alpha particle. Our system has four independent detectors mounted inside a liquid nitrogen/liquid helium cryostat. An adiabatic demagnetization refrigerator (ADR) cools the detector stage to its operating temperature of 80 mK. Temperature regulation with ˜15-μK peak-to-peak variation is achieved by PID control of the ADR. The detectors are voltage-biased, and the current signal is amplified by a commercial SQUID readout system and digitized for further analysis. This paper will discuss design and operation of our microcalorimeter alpha-particle spectrometer, and will show recent results.

  11. Early distinction system of mine fire in underground by using a neural-network system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ohga, Kotaro; Higuchi, Kiyoshi

    1996-12-31

    In our laboratory, a new detection system using smell detectors was developed to detect the spontaneous combustion of coal and the combustion of other materials used underground. The results of experiments clearly the combustion of materials can be detected earlier by this detection system than by conventional detectors for gas and smoke, and there were significant differences between output data from each smell detector for coal, rubber, oil and wood. In order to discern the source of combustion gases, we have been developing a distinction system using a neural-network system. It has shown successful results in laboratory tests. This papermore » describes our detection system using smell detectors and our distinction system which uses a neural-network system, and presents results of experiments using both systems.« less

  12. Amplification of the signal in triode structures of ion detectors based on 6H-SIC epitaxial films

    NASA Astrophysics Data System (ADS)

    Lebedev, A. A.; Strokan, N. B.; Ivanov, A. M.; Davydov, D. V.; Savkina, N. S.; Bogdanova, E. V.; Kuznetsov, A. N.; Yakimova, R.

    2001-12-01

    The possibility of about 50 times the inneramplification of signals in SiC-based detectors of short-range ions is shown. The detector has an n-p-n+-like structure, where the p-type base was grown epitaxially on a 6H n+-SiC substrate. To complete the structure a Schottky barrier was made on top. Detector parameters were investigated in a "floating base" regime. Alpha particles from 244Cm were used and the augmentation of signal (E) with increasing applied voltage (U) was investigated. A superlinear increase of E was observed with a significant (tens of times) amplification of the introduced by the alpha particle nonequilibrium charge. It was also found that the nonuniformity of the diffusion-drift carrier transport parameters in the films does not exceed 10%.

  13. Prototyping of Silicon Strip Detectors for the Inner Tracker of the ALICE Experiment

    NASA Astrophysics Data System (ADS)

    Sokolov, Oleksiy

    2006-04-01

    The ALICE experiment at CERN will study heavy ion collisions at a center-of-mass energy 5.5˜TeV per nucleon. Particle tracking around the interaction region at radii r<45 cm is done by the Inner Tracking System (ITS), consisting of six cylindrical layers of silicon detectors. The outer two layers of the ITS use double-sided silicon strip detectors. This thesis focuses on testing of these detectors and performance studies of the detector module prototypes at the beam test. Silicon strip detector layers will require about 20 thousand HAL25 front-end readout chips and about 3.5 thousand hybrids each containing 6 HAL25 chips. During the assembly procedure, chips are bonded on a patterned TAB aluminium microcables which connect to all the chip input and output pads, and then the chips are assembled on the hybrids. Bonding failures at the chip or hybrid level may either render the component non-functional or deteriorate its the performance such that it can not be used for the module production. After each bonding operation, the component testing is done to reject the non-functional or poorly performing chips and hybrids. The LabView-controlled test station for this operation has been built at Utrecht University and was successfully used for mass production acceptance tests of chips and hybrids at three production labs. The functionality of the chip registers, bonding quality and analogue functionality of the chips and hybrids are addressed in the test. The test routines were optimized to minimize the testing time to make sure that testing is not a bottleneck of the mass production. For testing of complete modules the laser scanning station with 1060 nm diode laser has been assembled at Utrecht University. The testing method relies of the fact that a response of the detector module to a short collimated laser beam pulse resembles a response to a minimum ionizing particle. A small beam spot size (˜7 μm ) allows to deposit the charge in a narrow region and measure the response of individual detector channels. First several module prototypes have been studied with this setup, the strip gain and charge sharing function have been measured, the later is compared with the model predictions. It was also shown that for a laser beam of a high monochromaticity, interference in the sensor bulk significantly modulates the deposited charge and introduces a systematic error of the gain measurement. Signatures of disconnected strips and pinholes defects have been observed, the response of the disconnected strips to the laser beam has been correlated with the noise measurements. Beam test of four prototype modules have been carried out at PS accelerator at CERN using 7 GeV/c pions. It was demonstrated that the modules provide an excellent signal-to-noise ratio in the range 40-75. The estimated spatial resolution for the normally incident tracks is about 18 μm using the center-of-gravity cluster reconstruction method. A non-iterative method for spatial resolution determination was developed, it was shown that in order to determine the resolution of each individual detector in the telescope, the telescope should consist of at least 5 detectors. The detectors showed high detection efficiency, in the order 99%. It was shown that the particle loss occurs mostly in the defected regions near the noisy strips or strips with a very low gain. The efficiency of the sensor area with nominal characteristics is consistent with 100%.

  14. Dynamic range considerations for EUV MAMA detectors. [Extreme UV Multianode Microchannel Array

    NASA Technical Reports Server (NTRS)

    Illing, Rainer M. E.; Bybee, Richard L.; Timothy, J. G.

    1990-01-01

    The multianode microchannel array (MAMA) has been chosen as the detector for two instruments on the ESA/NASA Solar Heliospheric Observatory. The response of the MAMA to the two extreme types of solar spectra, disk and corona, have been modeled with a view toward evaluating dynamic range effects present. The method of MAMA operation is discussed, with emphasis given to modeling the effect of electron cloud charge spreading to several detector anodes and amplifiers (n-fold events). Representative synthetic EUV spectra have been created. The detector response to these spectra is modeled by dissecting the input photon radiation field across the detector array into contributions to the various amplifier channels. The results of this dissection are shown for spectral regions across the entire wavelength region of interest. These results are used to identify regions in which total array photon counting rate or individual amplifier rate may exceed the design limits. This allows the design or operational modes to be tailored to eliminate the problem areas.

  15. Performance revaluation of a N-type coaxial HPGe detector with front edges crystal using MCNPX.

    PubMed

    Azli, Tarek; Chaoui, Zine-El-Abidine

    2015-03-01

    The MCNPX code was used to determine the efficiency of a N-type HPGe detector after two decades of operation. Accounting for the roundedness of the crystal`s front edges and an inhomogeneous description of the detector's dead layers were shown to achieve better agreement between measurements and simulation efficiency determination. The calculations were experimentally verified using point sources in the energy range from 50keV to 1400keV, and an overall uncertainty less than 2% was achieved. In order to use the detector for different matrices and geometries in radioactivity, the suggested model was validated by changing the counting geometry and by using multi-gamma disc sources. The introduced simulation approach permitted the revaluation of the performance of an HPGe detector in comparison of its initial condition, which is a useful tool for precise determination of the thickness of the inhomogeneous dead layer. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. The hybrid energy spectrum of Telescope Array's Middle Drum Detector and surface array

    NASA Astrophysics Data System (ADS)

    Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M. G.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, K.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shin, H. S.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

    2015-08-01

    The Telescope Array experiment studies ultra high energy cosmic rays using a hybrid detector. Fluorescence telescopes measure the longitudinal development of the extensive air shower generated when a primary cosmic ray particle interacts with the atmosphere. Meanwhile, scintillator detectors measure the lateral distribution of secondary shower particles that hit the ground. The Middle Drum (MD) fluorescence telescope station consists of 14 telescopes from the High Resolution Fly's Eye (HiRes) experiment, providing a direct link back to the HiRes measurements. Using the scintillator detector data in conjunction with the telescope data improves the geometrical reconstruction of the showers significantly, and hence, provides a more accurate reconstruction of the energy of the primary particle. The Middle Drum hybrid spectrum is presented and compared to that measured by the Middle Drum station in monocular mode. Further, the hybrid data establishes a link between the Middle Drum data and the surface array. A comparison between the Middle Drum hybrid energy spectrum and scintillator Surface Detector (SD) spectrum is also shown.

  17. Induced Charge Fluctuations in Semiconductor Detectors with a Cylindrical Geometry

    NASA Astrophysics Data System (ADS)

    Samedov, Victor V.

    2018-01-01

    Now, compound semiconductors are very appealing for hard X-ray room-temperature detectors for medical and astrophysical applications. Despite the attractive properties of compound semiconductors, such as high atomic number, high density, wide band gap, low chemical reactivity and long-term stability, poor hole and electron mobility-lifetime products degrade the energy resolution of these detectors. The main objective of the present study is in development of a mathematical model of the process of the charge induction in a cylindrical geometry with accounting for the charge carrier trapping. The formulae for the moments of the distribution function of the induced charge and the formulae for the mean amplitude and the variance of the signal at the output of the semiconductor detector with a cylindrical geometry were derived. It was shown that the power series expansions of the detector amplitude and the variance in terms of the inverse bias voltage allow determining the Fano factor, electron mobility lifetime product, and the nonuniformity level of the trap density of the semiconductor material.

  18. Adaptive Detector Arrays for Optical Communications Receivers

    NASA Technical Reports Server (NTRS)

    Vilnrotter, V.; Srinivasan, M.

    2000-01-01

    The structure of an optimal adaptive array receiver for ground-based optical communications is described and its performance investigated. Kolmogorov phase screen simulations are used to model the sample functions of the focal-plane signal distribution due to turbulence and to generate realistic spatial distributions of the received optical field. This novel array detector concept reduces interference from background radiation by effectively assigning higher confidence levels at each instant of time to those detector elements that contain significant signal energy and suppressing those that do not. A simpler suboptimum structure that replaces the continuous weighting function of the optimal receiver by a hard decision on the selection of the signal detector elements also is described and evaluated. Approximations and bounds to the error probability are derived and compared with the exact calculations and receiver simulation results. It is shown that, for photon-counting receivers observing Poisson-distributed signals, performance improvements of approximately 5 dB can be obtained over conventional single-detector photon-counting receivers, when operating in high background environments.

  19. Performance comparison of NE213 detectors for their application in moisture measurement

    PubMed

    Naqvi; Nagadi; Rehman; Kidwai

    2000-10-01

    The pulse shape discrimination (PSD) characteristic and neutron detection efficiency of NE213 detectors have been measured for their application in moisture measurements using 252Cf and 241Am-Be sources. In PSD studies, neutron peak to valley (Pn/V) ratio and figure of merit M were measured at four different bias values for cylindrical 50, 125 and 250 mm diameter NE213 detectors. The result of this study has shown that better PSD performance with the NE213 detector can be achieved with a smaller volume detector in conjunction with a neutron source with smaller gamma-ray/neutron ratio. The neutron detection efficiency of the 125 mm diameter NE213 detector for 241Am-Be and 252Cf source spectra was determined at 0.85, 1.25 and 1.75 MeV bias energies using the experimental neutron detection efficiency data of the same detector over 0.1-10 MeV energy range. Due to different energy spectra of the 241Am-Be and 252Cf sources, integrated efficiency of the 125 mm diameter NE213 detector for the two sources shows bias dependence. At smaller bias, 252Cf source has larger efficiency but as the bias is increased, the detector has larger efficiency for 241Am-Be source. This study has revealed that NE213 detector has better performance (such as PSD and neutron detection efficiency) in simultaneous detection of neutron and gamma-rays in moisture measurements, if it is used in conjunction with 241Am-Be source at higher detector bias.

  20. A decision directed detector for the phase incoherent Gaussian channel

    NASA Technical Reports Server (NTRS)

    Kazakos, D.

    1975-01-01

    A vector digital signalling scheme is proposed for simultaneous adaptive data transmission and phase estimation. The use of maximum likelihood estimation methods predicts a better performance than the phase-locked loop. The phase estimate is shown to converge to the true value, so that the adaptive nature of the detector effectively achieves phase acquisition and improvement in performance. No separate synchronization interval is required and phase fluctuations can be tracked simultaneously with the transmission of information.

  1. Systems and methods for data quality control and cleansing

    DOEpatents

    Wenzel, Michael; Boettcher, Andrew; Drees, Kirk; Kummer, James

    2016-05-31

    A method for detecting and cleansing suspect building automation system data is shown and described. The method includes using processing electronics to automatically determine which of a plurality of error detectors and which of a plurality of data cleansers to use with building automation system data. The method further includes using processing electronics to automatically detect errors in the data and cleanse the data using a subset of the error detectors and a subset of the cleansers.

  2. Signal-to-noise limitations in white light holography.

    PubMed

    Ribak, E; Roddier, C; Roddier, F; Breckinridge, J B

    1988-03-15

    A simple derivation is given for the signal-to-noise ratio (SNR) in images reconstructed from incoherent holograms. Dependence is shown to be on the hologram SNR, object complexity, and the number of pixels in the detector. Reconstruction of involved objects becomes possible with high dynamic range detectors such as charge coupled devices. We have produced such white light holograms by means of a rotational shear interferometer combined with a chromatic corrector. A digital inverse transform recreated the object.

  3. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lawrence, Chris C.; Febbraro, Michael; Massey, Thomas N.

    Organic scintillation detectors have shown promise as neutron detectors for characterizing special nuclear materials in various arms-control and homeland security applications. Recent advances have yielded a new plastic scintillator - EJ299-33 - with pulse-shape-discrimination (PSD) capability. Plastic scintillators would have a much expanded range of deployment relative to liquids and crystals. Here in this paper, we present a full characterization of pulse height response to fission-energy neutrons for an EJ299-33 detector with 7.62-by-7.62-cm cylindrical active volume, and compare with an EJ309 liquid scintillator in the same assembly. Scintillation light output relations, energy resolutions, and response matrices are presented for bothmore » detectors. A Continuous spectrum neutron source, obtained via the bombardment of 27Al with 7.44-MeV deuterons at the Edwards Accelerator Facility at Ohio University, was used for the measurement. A new procedure for evaluating and comparing PSD performance is presented which accounts for the effect of the light output relation on the ability to detect low energy neutrons. The EJ299-33 is shown to have considerable deficit in matrix condition, and in PSD figure of merit when compared to EJ309, especially when neutron energy is taken into account. Furthermore the EJ299 is likely to bring a modest PSD capability into a array of held applications that are not accessible to liquids or crystals.« less

  4. Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics

    NASA Astrophysics Data System (ADS)

    Rinderknecht, H. G.; Rojas-Herrera, J.; Zylstra, A. B.; Frenje, J. A.; Gatu Johnson, M.; Sio, H.; Sinenian, N.; Rosenberg, M. J.; Li, C. K.; Séguin, F. H.; Petrasso, R. D.; Filkins, T.; Steidle, Jeffrey A.; Steidle, Jessica A.; Traynor, N.; Freeman, C.

    2015-12-01

    The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1-100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protons with energies in the range 0.5-9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. The impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.

  5. Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rinderknecht, H. G.; Rojas-Herrera, J.; Zylstra, A. B.

    The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1–100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protonsmore » with energies in the range 0.5–9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. Furthermore, the impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.« less

  6. Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rinderknecht, H. G., E-mail: rinderknecht1@llnl.gov; Rojas-Herrera, J.; Zylstra, A. B.

    The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1–100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protonsmore » with energies in the range 0.5–9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. The impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.« less

  7. Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics

    DOE PAGES

    Rinderknecht, H. G.; Rojas-Herrera, J.; Zylstra, A. B.; ...

    2015-12-23

    The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1–100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protonsmore » with energies in the range 0.5–9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. Furthermore, the impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.« less

  8. Atomically Precise Surface Engineering for Producing Imagers

    NASA Technical Reports Server (NTRS)

    Nikzad, Shouleh (Inventor); Hoenk, Michael E. (Inventor); Greer, Frank (Inventor); Jones, Todd J. (Inventor)

    2015-01-01

    High-quality surface coatings, and techniques combining the atomic precision of molecular beam epitaxy and atomic layer deposition, to fabricate such high-quality surface coatings are provided. The coatings made in accordance with the techniques set forth by the invention are shown to be capable of forming silicon CCD detectors that demonstrate world record detector quantum efficiency (>50%) in the near and far ultraviolet (155 nm-300 nm). The surface engineering approaches used demonstrate the robustness of detector performance that is obtained by achieving atomic level precision at all steps in the coating fabrication process. As proof of concept, the characterization, materials, and exemplary devices produced are presented along with a comparison to other approaches.

  9. Semiconductor detector with smoothly tunable effective thickness for the study of ionization loss by moderately relativistic electrons

    NASA Astrophysics Data System (ADS)

    Shchagin, A. V.; Shul'ga, N. F.; Trofymenko, S. V.; Nazhmudinov, R. M.; Kubankin, A. S.

    2016-11-01

    The possibility of measurement of electrons ionization loss in Si layer of smoothly tunable thickness is shown in the proof-of-principle experiment. The Si surface-barrier detector with the depleted layer thickness controlled by the value of high voltage power supply has been used. Ionization loss spectra for electrons emitted by radioactive source 207Bi are presented and discussed. Experimental results for the most probable ionization loss in the Landau spectral peak are compared with theoretical calculations. The possibility of research of evolution of electromagnetic field of ultra-relativistic particles traversing media interface with the use of detectors with smoothly tunable thickness is proposed.

  10. Search for cosmic gamma rays with the Carpet-2 extensive air shower array

    NASA Astrophysics Data System (ADS)

    Dzhappuev, D. D.; Petkov, V. B.; Kudzhaev, A. U.; Klimenko, N. F.; Lidvansky, A. S.; Troitsky, S. V.

    2016-06-01

    The present-day status of the problem of searching for primary cosmic gamma rays at energies above 100 TeV is discussed, as well as a proposal for a new experiment in this field. It is shown that an increase of the area of the muon detector of the Carpet-2 air shower array up to 410 square meters, to be realized in 2016, will make this array quite competitive with past and existing experiments, especially at modest energies. Some preliminary results of measurements made with smaller area of the muon detector are presented together with estimates of expected results to be obtained with a coming large-area muon detector.

  11. Recent Results on Gridpix Detectors:. AN Integrated Micromegas Grid and a Micromegas Ageing Test

    NASA Astrophysics Data System (ADS)

    Chefdeville, M.; Aarts, A.; van der Graaf, H.; van der Putten, S.

    2006-04-01

    A new gas-filled detector combining a Micromegas with a CMOS pixel chip has been recently tested. A procedure to integrate the Micromegas grid onto silicon wafers (‘wafer post processing’) has been developed. We aim to eventually integrate the grid on top of wafers of CMOS pixel chips. The first part of this contribution describes an application in vertex detection (GOSSIP). Then tests of the first detector prototype of a grid integrated on a bare silicon wafer are shown. Finally an ageing test of a Micromegas chamber is presented. After verifying the chambers' proportionality at a very high dose rates, the device was irradiated until ageing became apparent.

  12. A Weak Value Based QKD Protocol Robust Against Detector Attacks

    NASA Astrophysics Data System (ADS)

    Troupe, James

    2015-03-01

    We propose a variation of the BB84 quantum key distribution protocol that utilizes the properties of weak values to insure the validity of the quantum bit error rate estimates used to detect an eavesdropper. The protocol is shown theoretically to be secure against recently demonstrated attacks utilizing detector blinding and control and should also be robust against all detector based hacking. Importantly, the new protocol promises to achieve this additional security without negatively impacting the secure key generation rate as compared to that originally promised by the standard BB84 scheme. Implementation of the weak measurements needed by the protocol should be very feasible using standard quantum optical techniques.

  13. Bulk and surface event identification in p-type germanium detectors

    NASA Astrophysics Data System (ADS)

    Yang, L. T.; Li, H. B.; Wong, H. T.; Agartioglu, M.; Chen, J. H.; Jia, L. P.; Jiang, H.; Li, J.; Lin, F. K.; Lin, S. T.; Liu, S. K.; Ma, J. L.; Sevda, B.; Sharma, V.; Singh, L.; Singh, M. K.; Singh, M. K.; Soma, A. K.; Sonay, A.; Yang, S. W.; Wang, L.; Wang, Q.; Yue, Q.; Zhao, W.

    2018-04-01

    The p-type point-contact germanium detectors have been adopted for light dark matter WIMP searches and the studies of low energy neutrino physics. These detectors exhibit anomalous behavior to events located at the surface layer. The previous spectral shape method to identify these surface events from the bulk signals relies on spectral shape assumptions and the use of external calibration sources. We report an improved method in separating them by taking the ratios among different categories of in situ event samples as calibration sources. Data from CDEX-1 and TEXONO experiments are re-examined using the ratio method. Results are shown to be consistent with the spectral shape method.

  14. An evaluation of a carbon monoxide poisoning education program.

    PubMed

    Schwartz, Lauren; Martinez, Luz; Louie, Jean; Mercurio-Zappala, Maria; Howland, Mary Ann; Nokes, Kathleen; Hoffman, Robert S

    2010-05-01

    Carbon monoxide (CO) is the leading cause of poisoning death in the United States. Research has shown that proper use of a CO detector in the home can reduce morbidity and mortality related to unintentional CO exposure. The authors evaluated three CO education workshops that included distribution of free CO detectors for home use, and their intervention reached 133 participants. Pretest surveys and follow-up calls evaluated change in knowledge and behavior factors. Results showed that statistically significant increases were found on three out of five knowledge-based items and 91% of respondents (N = 80) reported installing CO detectors in their home. Follow-up calls provided an opportunity to clarify information and provide tailored information to participants.

  15. Development problem analysis of correlation leak detector’s software

    NASA Astrophysics Data System (ADS)

    Faerman, V. A.; Avramchuk, V. S.; Marukyan, V. M.

    2018-05-01

    In the article, the practical application and the structure of the correlation leak detectors’ software is studied and the task of its designing is analyzed. In the first part of the research paper, the expediency of the facilities development of correlation leak detectors for the following operating efficiency of public utilities exploitation is shown. The analysis of the functional structure of correlation leak detectors is conducted and its program software tasks are defined. In the second part of the research paper some development steps of the software package – requirement forming, program structure definition and software concept creation – are examined in the context of the usage experience of the hardware-software prototype of correlation leak detector.

  16. Lasercom system architecture with reduced complexity

    NASA Technical Reports Server (NTRS)

    Lesh, James R. (Inventor); Chen, Chien-Chung (Inventor); Ansari, Homayoon (Inventor)

    1994-01-01

    Spatial acquisition and precision beam pointing functions are critical to spaceborne laser communication systems. In the present invention, a single high bandwidth CCD detector is used to perform both spatial acquisition and tracking functions. Compared to previous lasercom hardware design, the array tracking concept offers reduced system complexity by reducing the number of optical elements in the design. Specifically, the design requires only one detector and one beam steering mechanism. It also provides the means to optically close the point-ahead control loop. The technology required for high bandwidth array tracking was examined and shown to be consistent with current state of the art. The single detector design can lead to a significantly reduced system complexity and a lower system cost.

  17. LaserCom System Architecture With Reduced Complexity

    NASA Technical Reports Server (NTRS)

    Lesh, James R. (Inventor); Chen, Chien-Chung (Inventor); Ansari, Homa-Yoon (Inventor)

    1996-01-01

    Spatial acquisition and precision beam pointing functions are critical to spaceborne laser communication systems. In the present invention a single high bandwidth CCD detector is used to perform both spatial acquisition and tracking functions. Compared to previous lasercom hardware design, the array tracking concept offers reduced system complexity by reducing the number of optical elements in the design. Specifically, the design requires only one detector and one beam steering mechanism. It also provides means to optically close the point-ahead control loop. The technology required for high bandwidth array tracking was examined and shown to be consistent with current state of the art. The single detector design can lead to a significantly reduced system complexity and a lower system cost.

  18. Focal Plane Alignment Utilizing Optical CMM

    NASA Technical Reports Server (NTRS)

    Liebe, Carl Christian; Meras, Patrick L.; Clark, Gerald J.; Sedaka, Jack J.; Kaluzny, Joel V.; Hirsch, Brian; Decker, Todd A.; Scholtz, Christopher R.

    2012-01-01

    In many applications, an optical detector has to be located relative to mechanical reference points. One solution is to specify stringent requirements on (1) mounting the optical detector relative to the chip carrier, (2) soldering the chip carrier onto the printed circuit board (PCB), and (3) installing the PCB to the mechanical structure of the subsystem. Figure 1 shows a sketch of an optical detector mounted relative to mechanical reference with high positional accuracy. The optical detector is typically a fragile wafer that cannot be physically touched by any measurement tool. An optical coordinate measuring machine (CMM) can be used to position optical detectors relative to mechanical reference points. This approach will eliminate all requirements on positional tolerances. The only requirement is that the PCB is manufactured with oversized holes. An exaggerated sketch of this situation is shown in Figure 2. The sketch shows very loose tolerances on mounting the optical detector in the chip carrier, loose tolerance on soldering the chip carrier to the PCB, and finally large tolerance on where the mounting screws are located. The PCB is held with large screws and oversized holes. The PCB is mounted loosely so it can move freely around. The optical CMM measures the mechanical reference points. Based on these measurements, the required positions of the optical detector corners can be calculated. The optical CMM is commanded to go to the position where one detector corner is supposed to be. This is indicated with the cross-hairs in Figure 2(a). This figure is representative of the image of the optical CMM monitor. Using a suitable tapping tool, the PCB is manually tapped around until the corner of the optical detector is at the crosshairs of the optical CMM. The CMM is commanded to another corner, and the process is repeated a number of times until all corners of the optical detector are within a distance of 10 to 30 microns of the required position. The situation is sketched in Figure 2(b) (the figure also shows the tapping tool and where to tap). At this point the fasteners for the PCB are torqued slightly so the PCB can still move. The PCB location is adjusted again with the tapping tool. This process is repeated 3 to 4 times until the final torque is achieved. The oversized mounting holes are then filled with a liquid bonding agent to secure the board in position (not shown in the sketch). A 10- to 30-micron mounting accuracy has been achieved utilizing this method..

  19. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kolbasin, V. A.; Ivanov, A. I.; Pedash, V. Y.

    The two pulse shape discrimination methods were implemented in real-time. The pulse gradient analysis method was implemented programmatically on PC. The method based on artificial neural network was programmatically implemented using CUDA platform. It is shown that both implementations can provide up to 10{sup 6} pulses per second processing performance. The results for pulse shape discrimination using polycrystalline stilbene and LiF detectors were shown. (authors)

  20. Design Study of the Absorber Detector of a Compton Camera for On-Line Control in Ion Beam Therapy

    NASA Astrophysics Data System (ADS)

    Richard, M.-H.; Dahoumane, M.; Dauvergne, D.; De Rydt, M.; Dedes, G.; Freud, N.; Krimmer, J.; Letang, J. M.; Lojacono, X.; Maxim, V.; Montarou, G.; Ray, C.; Roellinghoff, F.; Testa, E.; Walenta, A. H.

    2012-10-01

    The goal of this study is to tune the design of the absorber detector of a Compton camera for prompt γ-ray imaging during ion beam therapy. The response of the Compton camera to a photon point source with a realistic energy spectrum (corresponding to the prompt γ-ray spectrum emitted during the carbon irradiation of a water phantom) is studied by means of Geant4 simulations. Our Compton camera consists of a stack of 2 mm thick silicon strip detectors as a scatter detector and of a scintillator plate as an absorber detector. Four scintillators are considered: LYSO, NaI, LaBr3 and BGO. LYSO and BGO appear as the most suitable materials, due to their high photo-electric cross-sections, which leads to a high percentage of fully absorbed photons. Depth-of-interaction measurements are shown to have limited influence on the spatial resolution of the camera. In our case, the thickness which gives the best compromise between a high percentage of photons that are fully absorbed and a low parallax error is about 4 cm for the LYSO detector and 4.5 cm for the BGO detector. The influence of the width of the absorber detector on the spatial resolution is not very pronounced as long as it is lower than 30 cm.

  1. Distributions-per-level: a means of testing level detectors and models of patch-clamp data.

    PubMed

    Schröder, I; Huth, T; Suitchmezian, V; Jarosik, J; Schnell, S; Hansen, U P

    2004-01-01

    Level or jump detectors generate the reconstructed time series from a noisy record of patch-clamp current. The reconstructed time series is used to create dwell-time histograms for the kinetic analysis of the Markov model of the investigated ion channel. It is shown here that some additional lines in the software of such a detector can provide a powerful new means of patch-clamp analysis. For each current level that can be recognized by the detector, an array is declared. The new software assigns every data point of the original time series to the array that belongs to the actual state of the detector. From the data sets in these arrays distributions-per-level are generated. Simulated and experimental time series analyzed by Hinkley detectors are used to demonstrate the benefits of these distributions-per-level. First, they can serve as a test of the reliability of jump and level detectors. Second, they can reveal beta distributions as resulting from fast gating that would usually be hidden in the overall amplitude histogram. Probably the most valuable feature is that the malfunctions of the Hinkley detectors turn out to depend on the Markov model of the ion channel. Thus, the errors revealed by the distributions-per-level can be used to distinguish between different putative Markov models of the measured time series.

  2. A miniature Joule-Thomson cooler for optical detectors in space.

    PubMed

    Derking, J H; Holland, H J; Tirolien, T; ter Brake, H J M

    2012-04-01

    The utilization of single-stage micromachined Joule-Thomson (JT) coolers for cooling small optical detectors is investigated. A design of a micromachined JT cold stage-detector system is made that focuses on the interface between a JT cold stage and detector, and on the wiring of the detector. Among various techniques, adhesive bonding is selected as most suitable technique for integrating the detector with the JT cold stage. Also, the optimum wiring of the detector is discussed. In this respect, it is important to minimize the heat conduction through the wiring. Therefore, each wire should be optimized in terms of acceptable impedance and thermal heat load. It is shown that, given a certain impedance, the conductive heat load of electrically bad conducting materials is about twice as high as that of electrically good conducting materials. A micromachined JT cold stage is designed and integrated with a dummy detector. The JT cold stage is operated at 100 K with nitrogen as the working fluid and at 140 K with methane. Net cooling powers of 143 mW and 117 mW are measured, respectively. Taking into account a radiative heat load of 40 mW, these measured values make the JT cold stage suitable for cooling a photon detector with a power dissipation up to 50 mW, allowing for another 27 to 53 mW heat load arising from the electrical leads. © 2012 American Institute of Physics

  3. Predictive modeling of infrared detectors and material systems

    NASA Astrophysics Data System (ADS)

    Pinkie, Benjamin

    Detectors sensitive to thermal and reflected infrared radiation are widely used for night-vision, communications, thermography, and object tracking among other military, industrial, and commercial applications. System requirements for the next generation of ultra-high-performance infrared detectors call for increased functionality such as large formats (> 4K HD) with wide field-of-view, multispectral sensitivity, and on-chip processing. Due to the low yield of infrared material processing, the development of these next-generation technologies has become prohibitively costly and time consuming. In this work, it will be shown that physics-based numerical models can be applied to predictively simulate infrared detector arrays of current technological interest. The models can be used to a priori estimate detector characteristics, intelligently design detector architectures, and assist in the analysis and interpretation of existing systems. This dissertation develops a multi-scale simulation model which evaluates the physics of infrared systems from the atomic (material properties and electronic structure) to systems level (modulation transfer function, dense array effects). The framework is used to determine the electronic structure of several infrared materials, optimize the design of a two-color back-to-back HgCdTe photodiode, investigate a predicted failure mechanism for next-generation arrays, and predict the systems-level measurables of a number of detector architectures.

  4. MCNP-REN - A Monte Carlo Tool for Neutron Detector Design Without Using the Point Model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Abhold, M.E.; Baker, M.C.

    1999-07-25

    The development of neutron detectors makes extensive use of the predictions of detector response through the use of Monte Carlo techniques in conjunction with the point reactor model. Unfortunately, the point reactor model fails to accurately predict detector response in common applications. For this reason, the general Monte Carlo N-Particle code (MCNP) was modified to simulate the pulse streams that would be generated by a neutron detector and normally analyzed by a shift register. This modified code, MCNP - Random Exponentially Distributed Neutron Source (MCNP-REN), along with the Time Analysis Program (TAP) predict neutron detector response without using the pointmore » reactor model, making it unnecessary for the user to decide whether or not the assumptions of the point model are met for their application. MCNP-REN is capable of simulating standard neutron coincidence counting as well as neutron multiplicity counting. Measurements of MOX fresh fuel made using the Underwater Coincidence Counter (UWCC) as well as measurements of HEU reactor fuel using the active neutron Research Reactor Fuel Counter (RRFC) are compared with calculations. The method used in MCNP-REN is demonstrated to be fundamentally sound and shown to eliminate the need to use the point model for detector performance predictions.« less

  5. A comparative study of silicon detector degradation under irradiation by heavy ions and relativistic protons

    NASA Astrophysics Data System (ADS)

    Eremin, V.; Mitina, D.; Fomichev, A.; Kiselev, O.; Egorov, N.; Eremin, I.; Shepelev, A.; Verbitskaya, E.

    2018-01-01

    Silicon detectors irradiated by 40Ar ions with the energy of 1.62 GeV were studied with the goal to find the parameters of radiation damage induced by ions. The measurements of the I-V characteristics, temperature dependences of the detector bulk current, deep level spectra and current pulse response were carried out for detectors irradiated within the fluence range 5×1010-2.3×1013 ion/cm2 and the obtained results were compared with the corresponding data for detectors irradiated by 23 GeV protons. It is shown that the processes of defect introduction by ions and overall radiation damage are similar to those induced by 23 GeV protons, while the introduction rates of radiation defects and current generation centers are about ten times higher for irradiation by 40Ar ions. The fact that these processes have much in common gives grounds to use the physical models and characteristic parametrization such as those developed earlier for detectors irradiated by protons and neutrons to build the long-term scenario of Si detector operation in the Time-Of-Flight diagnostic system of Super FRagment Separator designed at GSI for the future Facility for Antiproton and Ion Research, FAIR.

  6. FPGA-based gating and logic for multichannel single photon counting

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pooser, Raphael C; Earl, Dennis Duncan; Evans, Philip G

    2012-01-01

    We present results characterizing multichannel InGaAs single photon detectors utilizing gated passive quenching circuits (GPQC), self-differencing techniques, and field programmable gate array (FPGA)-based logic for both diode gating and coincidence counting. Utilizing FPGAs for the diode gating frontend and the logic counting backend has the advantage of low cost compared to custom built logic circuits and current off-the-shelf detector technology. Further, FPGA logic counters have been shown to work well in quantum key distribution (QKD) test beds. Our setup combines multiple independent detector channels in a reconfigurable manner via an FPGA backend and post processing in order to perform coincidencemore » measurements between any two or more detector channels simultaneously. Using this method, states from a multi-photon polarization entangled source are detected and characterized via coincidence counting on the FPGA. Photons detection events are also processed by the quantum information toolkit for application testing (QITKAT)« less

  7. X-ray analog pixel array detector for single synchrotron bunch time-resolved imaging.

    PubMed

    Koerner, Lucas J; Gruner, Sol M

    2011-03-01

    Dynamic X-ray studies can reach temporal resolutions limited by only the X-ray pulse duration if the detector is fast enough to segregate synchrotron pulses. An analog integrating pixel array detector with in-pixel storage and temporal resolution of around 150 ns, sufficient to isolate pulses, is presented. Analog integration minimizes count-rate limitations and in-pixel storage captures successive pulses. Fundamental tests of noise and linearity as well as high-speed laser measurements are shown. The detector resolved individual bunch trains at the Cornell High Energy Synchrotron Source at levels of up to 3.7 × 10(3) X-rays per pixel per train. When applied to turn-by-turn X-ray beam characterization, single-shot intensity measurements were made with a repeatability of 0.4% and horizontal oscillations of the positron cloud were detected.

  8. X-ray analog pixel array detector for single synchrotron bunch time-resolved imaging

    PubMed Central

    Koerner, Lucas J.; Gruner, Sol M.

    2011-01-01

    Dynamic X-ray studies can reach temporal resolutions limited by only the X-ray pulse duration if the detector is fast enough to segregate synchrotron pulses. An analog integrating pixel array detector with in-pixel storage and temporal resolution of around 150 ns, sufficient to isolate pulses, is presented. Analog integration minimizes count-rate limitations and in-pixel storage captures successive pulses. Fundamental tests of noise and linearity as well as high-speed laser measurements are shown. The detector resolved individual bunch trains at the Cornell High Energy Synchrotron Source at levels of up to 3.7 × 103 X-rays per pixel per train. When applied to turn-by-turn X-ray beam characterization, single-shot intensity measurements were made with a repeatability of 0.4% and horizontal oscillations of the positron cloud were detected. PMID:21335901

  9. Precision Neutron Time-of-Flight Detectors Provide Insight into NIF Implosion Dynamics

    NASA Astrophysics Data System (ADS)

    Schlossberg, David; Eckart, M. J.; Grim, G. P.; Hartouni, E. P.; Hatarik, R.; Moore, A. S.; Waltz, C. S.

    2017-10-01

    During inertial confinement fusion, higher-order moments of neutron time-of-flight (nToF) spectra can provide essential information for optimizing implosions. The nToF diagnostic suite at the National Ignition Facility (NIF) was recently upgraded to include novel, quartz Cherenkov detectors. These detectors exploit the rapid Cherenkov radiation process, in contrast with conventional scintillator decay times, to provide high temporal-precision measurements that support higher-order moment analyses. Preliminary measurements have been made on the NIF during several implosions and initial results are presented here. Measured line-of-sight asymmetries, for example in ion temperatures, will be discussed. Finally, advanced detector optimization is shown to advance accessible physics, with possibilities for energy discrimination, gamma source identification, and further reduction in quartz response times. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  10. Cryogenic microcalorimeter system for ultra-high resolution alpha-particle spectrometry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rabin, Michael W; Hoover, Andrew S; Bacrania, Mnesh K

    2009-01-01

    Microcalorimeters have been shown to yield unsurpassed energy resolution for alpha spectrometry, up to 1.06 keV FWHM at 5.3 MeV. These detectors use a superconducting transition-edge sensor (TES) to measure the temperature change in an absorber from energy deposited by an interacting alpha particle. Our system has four independent detectors mounted inside a liquid nitrogen/liquid helium cryostat. An adiabatic demagnetization refrigerator (ADR) cools the detector stage to its operating temperature of 80 mK. Temperature regulation with {approx}15 uK peak-to-peak variation is achieved by PID control of the ADR. The detectors are voltage-biased, and the current signal is amplified by amore » commercial SQUID readout system and digitized for further analysis, This paper will discuss design and operation of our microcalorimeter alpha spectrometer, and will show recent results.« less

  11. Printable sensors for explosive detonation

    NASA Astrophysics Data System (ADS)

    Griffith, Matthew J.; Cooling, Nathan A.; Elkington, Daniel C.; Muller, Elmar; Belcher, Warwick J.; Dastoor, Paul C.

    2014-10-01

    Here, we report the development of an organic thin film transistor (OTFT) based on printable solution processed polymers and employing a quantum tunnelling composite material as a sensor to convert the pressure wave output from detonation transmission tubing (shock tube) into an inherently amplified electronic signal for explosives initiation. The organic electronic detector allows detection of the signal in a low voltage operating range, an essential feature for sites employing live ordinances that is not provided by conventional electronic devices. We show that a 30-fold change in detector response is possible using the presented detector assembly. Degradation of the OTFT response with both time and repeated voltage scans was characterised, and device lifetime is shown to be consistent with the requirements for on-site printing and usage. The integration of a low cost organic electronic detector with inexpensive shock tube transmission fuse presents attractive avenues for the development of cheap and simple assemblies for precisely timed initiation of explosive chains.

  12. Background Equatorial Astronomical Measurements Focal Plane Assembly (Refurbished HI STAR SOUTH)

    DTIC Science & Technology

    1984-09-01

    Subassembly RPT41412 MOSFETs during assembly and test. The old and new designs are shown in Fig- ure 7. The copper webs between the first and second and...machined in the remaining webs be- tween the detector recesses and through a small hole drilled through the frame to connect the traces of all four...gold wirebond routed through a notch machined in the frame web between one of the detector recesses and the board recess. The sap- phire support

  13. New methods of subcooled water recognition in dew point hygrometers

    NASA Astrophysics Data System (ADS)

    Weremczuk, Jerzy; Jachowicz, Ryszard

    2001-08-01

    Two new methods of sub-cooled water recognition in dew point hygrometers are presented in this paper. The first one- impedance method use a new semiconductor mirror in which the dew point detector, the thermometer and the heaters were integrated all together. The second one an optical method based on a multi-section optical detector is discussed in the report. Experimental results of both methods are shown. New types of dew pont hydrometers of ability to recognized sub-cooled water were proposed.

  14. Linewidth Narrowing and Purcell Enhancement in Photonic Crystal Cavities on an Er-Doped Silicon Nitride Platform

    DTIC Science & Technology

    2010-02-01

    Low noise superconducting single photon detectors on silicon,” Appl. Phys. Lett. 93, 131101 (2008). 20. M. T. Tanner, C. M. Natarajan, V. K... wavelength sensitivity in NbTiN superconducting nanowire single-photon detectors fabricated on oxidized silicon substrates,” Proceedings of Single...cavity resonance wavelength and Q-factor for the PC cavity are shown in Figure 3. The data are taken both at low (0.050 mW) pump power and high (30 mW

  15. Proceedings of the Special Meeting on the Physics of Detectors Held at U.S. Naval Training Device Center, Orlando, Florida, on 15 March 1972

    DTIC Science & Technology

    1972-08-01

    manufacture. The bias is well within the power rating of the device. -le havo also seer. similar noise in lead- sulphide detectors. The noiie shown xeseibles...University Syracuse, New York ABSTRACT (Unclassified) The recombination cross section for mercury -doped germanium has been measured between 4-40 K, irt...in the mercury -doped samples was accounted for by quantitatively determining the density of these centers from carrier concentration and mobility

  16. Dependence of the Energy Resolution of a Hemispherical Semiconductor Detector on the Bias Voltage

    NASA Astrophysics Data System (ADS)

    Samedov, V. V.

    2017-12-01

    It is shown that the series expansion of the amplitude and variance of the hemispherical semiconductor detector signal in inverse bias voltage allows finding the Fano factor, the product of electron lifetime and mobility, the degree of inhomogeneity of the trap density in the semiconductor material, and the relative variance of the electronic channel gain. An important advantage of the proposed method is that it is independent of the electronic channel gain and noise.

  17. Development of a new type of germanium detector for dark matter searches

    NASA Astrophysics Data System (ADS)

    Wei, Wenzhao

    Monte Carlo simulation is an important tool used to develop a better understanding of important physical processes. This thesis describes three Monte Carlo simulations used to understand germanium detector response to low energy nuclear recoils and radiogenic backgrounds for direct dark matter searches. The first simulation is the verification of Barker-Mei model, a theoretical model for calculating the ionization efficiency for germanium detector for the energy range of 1 - 100 keV. Utilizing the shape analysis, a bin-to-bin comparison between simulation and experimental data was performed for verifying the accuracy of the Barker-Mei model. A percentage difference within 4% was achieved between data and simulation, which showed the validity of the Barker-Mei model. The second simulation is the study of a new type of germanium detector for n/gamma discrimination at 77 K with plasma time difference in pulse shape. Due to the poor time resolution, conventional P-type Point Contact (PPC) and coaxial germanium detectors are not capable of discriminating nuclear recoils from electron recoils. In this thesis, a new idea of using great detector granularity and plasma time difference in pulse shape to discriminate nuclear recoils from electron recoils with planar germanium detectors in strings was discussed. The anticipated sensitivity of this new detector array is shown for detecting dark matter. The last simulation is a study of a new type of germanium-detector array serving as a PMT screening facility for ultra-low background dark matter experiments using noble liquid xenon as detector material such LUX/LZ and XENON100/XENON1T. A well-shaped germanium detector array and a PMT were simulated to study the detector response to the signal and background for a better understanding of the radiogenic gamma rays from PMTs. The detector efficiency and other detector performance were presented in this work.

  18. Costing Future Complex and Novel Projects

    DTIC Science & Technology

    2016-04-30

    qÜáêíÉÉåíÜ=^ååì~ä= ^Åèìáëáíáçå=oÉëÉ~êÅÜ= póãéçëáìã= qÜìêëÇ~ó=pÉëëáçåë= sçäìãÉ=ff= = Costing Future Complex & Novel Projects Michael Pryce, Centre for Defence ...Novel Projects Michael Pryce, Centre for Defence Acquisition, Cranfield University Controlling Costs: The 6-3-5 Method—Case Studies at NAVSEA and...a Lecturer in defence acquisition at Cranfield University. He teaches across a range of subjects, including the use of costing in acquisition and

  19. Low Gain Avalanche Detectors (LGAD) for particle physics and synchrotron applications

    NASA Astrophysics Data System (ADS)

    Moffat, N.; Bates, R.; Bullough, M.; Flores, L.; Maneuski, D.; Simon, L.; Tartoni, N.; Doherty, F.; Ashby, J.

    2018-03-01

    A new avalanche silicon detector concept is introduced with a low gain in the region of ten, known as a Low Gain Avalanche Detector, LGAD. The detector's characteristics are simulated via a full process simulation to obtain the required doping profiles which demonstrate the desired operational characteristics of high breakdown voltage (500 V) and a gain of 10 at 200 V reverse bias for X-ray detection. The first low gain avalanche detectors fabricated by Micron Semiconductor Ltd are presented. The doping profiles of the multiplication junctions were measured with SIMS and reproduced by simulating the full fabrication process which enabled further development of the manufacturing process. The detectors are 300 μm thick p-type silicon with a resistivity of 8.5 kΩcm, which fully depletes at 116 V. The current characteristics are presented and demonstrate breakdown voltages in excess of 500 V and a current density of 40 to 100 nAcm‑2 before breakdown measured at 20oC. The gain of the LGAD has been measured with a red laser (660 nm) and shown to be between 9 and 12 for an external bias voltage range from 150 V to 300 V.

  20. Spin-dependent limits from the DRIFT-IId directional dark matter detector

    NASA Astrophysics Data System (ADS)

    Daw, E.; Fox, J. R.; Gauvreau, J.-L.; Ghag, C.; Harmon, L. J.; Gold, M.; Lee, E. R.; Loomba, D.; Miller, E. H.; Murphy, A. Stj.; Paling, S. M.; Landers, J. M.; Pipe, M.; Pushkin, K.; Robinson, M.; Snowden-Ifft, D. P.; Spooner, N. J. C.; Walker, D.

    2012-02-01

    Data are presented from the DRIFT-IId detector operated in the Boulby Underground Science Facility in England. A 0.8 m3 fiducial volume, containing partial pressures of 30 Torr CS2 and 10 Torr CF4, was exposed for a duration of 47.4 live-time days with sufficient passive shielding to provide a neutron free environment within the detector. The nuclear recoil events seen are consistent with a remaining low-level background from the decay of radon daughters attached to the central cathode of the detector. However, charge from such events must drift across the entire width of the detector, and thus display large diffusion upon reaching the readout planes of the device. Exploiting this feature, it is shown to be possible to reject energy depositions from these Radon Progeny Recoil events while still retaining sensitivity to fiducial-volume nuclear recoil events. The response of the detector is then interpreted, using the F nuclei content of the gas, in terms of sensitivity to proton spin-dependent WIMP-nucleon interactions, displaying a minimum in sensitivity cross section at 1.8 pb for a WIMP mass of 100 GeV/c2. This sensitivity was achieved without compromising the direction sensitivity of DRIFT.

  1. SiC-based Photo-detectors for UV, VUV, EUV and Soft X-ray Detection

    NASA Technical Reports Server (NTRS)

    Yan, Feng

    2006-01-01

    A viewgraph presentation describing an ideal Silicon Carbide detector for ultraviolet, vacuum ultraviolet, extreme ultraviolet and soft x-ray detection is shown. The topics include: 1) An ideal photo-detector; 2) Dark current density of SiC photodiodes at room temperature; 3) Dark current in SiC detectors; 4) Resistive and capacitive feedback trans-impedance amplifier; 5) Avalanche gain; 6) Excess noise; 7) SNR in single photon counting mode; 8) Structure of SiC single photon counting APD and testing structure; 9) Single photon counting waveform and testing circuit; 10) Amplitude of SiC single photon counter; 11) Dark count of SiC APD photon counters; 12) Temperature-dependence of dark count rate; 13) Reduce the dark count rate by reducing the breakdown electric field; 14) Spectrum range for SiC detectors; 15) QE curves of Pt/4H-SiC photodiodes; 16) QE curve of SiC; 17) QE curves of SiC photodiode vs. penetration depth; 18) Visible rejection of SiC photodiodes; 19) Advantages of SiC photodiodes; 20) Competitors of SiC detectors; 21) Extraterrestrial solar spectra; 22) Visible-blind EUV detection; 23) Terrestrial solar spectra; and 24) Less than 1KeV soft x-ray detection.

  2. CdZnTe γ detector for deep inelastic neutron scattering on the VESUVIO spectrometer

    NASA Astrophysics Data System (ADS)

    Andreani, C.; D'Angelo, A.; Gorini, G.; Imberti, S.; Pietropaolo, A.; Rhodes, N. J.; Schooneveld, E. M.; Senesi, R.; Tardocchi, M.

    In this paper it is shown that solid-state cadmium-zinc-telluride (CZT) is a promising photon detector for neutron spectroscopy in a wide energy interval, ranging from thermal ( 25 meV) to epithermal ( 70 eV) neutron energies. In the present study two CZT detectors were tested as part of the inverse-geometry neutron spectrometer VESUVIO operating at the ISIS pulsed neutron source. The response of the CZT detector to photon emission from radiative neutron capture in 238U was determined by biparametric measurements of neutron time of flight and photon energy. The scattering response function F(y) from a Pb sample has been derived using both CZT and conventional 6Li-glass scintillator detectors. The former showed both an improved signal to background ratio and higher efficiency as compared to 6Li glass, allowing us to measure F(y) up to the fourth 238U absorption energy (Er=66.02 eV). Due to the small size of CZT detectors, their use is envisaged in arrays, with high spatial resolution, for neutron-scattering studies at high energy (ω>1 eV) and low wavevector (q <10 Å-1) transfers.

  3. The trajectories of secondary electrons in the scanning electron microscope.

    PubMed

    Konvalina, Ivo; Müllerová, Ilona

    2006-01-01

    Three-dimensional simulations of the trajectories of secondary electrons (SE) in the scanning electron microscope have been performed for plenty of real configurations of the specimen chamber, including all its basic components. The primary purpose was to evaluate the collection efficiency of the Everhart-Thornley detector of SE and to reveal fundamental rules for tailoring the set-ups in which efficient signal acquisition can be expected. Intuitive realizations about the easiness of attracting the SEs towards the biased front grid of the detector have shown themselves likely as false, and all grounded objects in the chamber have been proven to influence the spatial distribution of the signal-extracting field. The role of the magnetic field penetrating from inside the objective lens is shown to play an ambiguous role regarding possible support for the signal collection.

  4. A recursive linear predictive vocoder

    NASA Astrophysics Data System (ADS)

    Janssen, W. A.

    1983-12-01

    A non-real time 10 pole recursive autocorrelation linear predictive coding vocoder was created for use in studying effects of recursive autocorrelation on speech. The vocoder is composed of two interchangeable pitch detectors, a speech analyzer, and speech synthesizer. The time between updating filter coefficients is allowed to vary from .125 msec to 20 msec. The best quality was found using .125 msec between each update. The greatest change in quality was noted when changing from 20 msec/update to 10 msec/update. Pitch period plots for the center clipping autocorrelation pitch detector and simplified inverse filtering technique are provided. Plots of speech into and out of the vocoder are given. Formant versus time three dimensional plots are shown. Effects of noise on pitch detection and formants are shown. Noise effects the voiced/unvoiced decision process causing voiced speech to be re-constructed as unvoiced.

  5. Decision-theoretic saliency: computational principles, biological plausibility, and implications for neurophysiology and psychophysics.

    PubMed

    Gao, Dashan; Vasconcelos, Nuno

    2009-01-01

    A decision-theoretic formulation of visual saliency, first proposed for top-down processing (object recognition) (Gao & Vasconcelos, 2005a), is extended to the problem of bottom-up saliency. Under this formulation, optimality is defined in the minimum probability of error sense, under a constraint of computational parsimony. The saliency of the visual features at a given location of the visual field is defined as the power of those features to discriminate between the stimulus at the location and a null hypothesis. For bottom-up saliency, this is the set of visual features that surround the location under consideration. Discrimination is defined in an information-theoretic sense and the optimal saliency detector derived for a class of stimuli that complies with known statistical properties of natural images. It is shown that under the assumption that saliency is driven by linear filtering, the optimal detector consists of what is usually referred to as the standard architecture of V1: a cascade of linear filtering, divisive normalization, rectification, and spatial pooling. The optimal detector is also shown to replicate the fundamental properties of the psychophysics of saliency: stimulus pop-out, saliency asymmetries for stimulus presence versus absence, disregard of feature conjunctions, and Weber's law. Finally, it is shown that the optimal saliency architecture can be applied to the solution of generic inference problems. In particular, for the class of stimuli studied, it performs the three fundamental operations of statistical inference: assessment of probabilities, implementation of Bayes decision rule, and feature selection.

  6. Calculated effects of backscattering on skin dosimetry for nuclear fuel fragments.

    PubMed

    Aydarous, A Sh

    2008-01-01

    The size of hot particles contained in nuclear fallout ranges from 10 nm to 20 microm for the worldwide weapons fallout. Hot particles from nuclear power reactors can be significantly bigger (100 microm to several millimetres). Electron backscattering from such particles is a prominent secondary effect in beta dosimetry for radiological protection purposes, such as skin dosimetry. In this study, the effect of electron backscattering due to hot particles contamination on skin dose is investigated. These include parameters such as detector area, source radius, source energy, scattering material and source density. The Monte-Carlo Neutron Particle code (MCNP4C) was used to calculate the depth dose distribution for 10 different beta sources and various materials. The backscattering dose factors (BSDF) were then calculated. A significant dependence is shown for the BSDF magnitude upon detector area, source radius and scatterers. It is clearly shown that the BSDF increases with increasing detector area. For high Z scatterers, the BSDF can reach as high as 40 and 100% for sources with radii 0.1 and 0.0001 cm, respectively. The variation of BSDF with source radius, source energy and source density is discussed.

  7. Polyion selective polymeric membrane-based pulstrode as a detector in flow-injection analysis.

    PubMed

    Bell-Vlasov, Andrea K; Zajda, Joanna; Eldourghamy, Ayman; Malinowska, Elzbieta; Meyerhoff, Mark E

    2014-04-15

    A method for the detection of polyions using fully reversible polyion selective polymeric membrane type pulstrodes as detectors in a flow-injection analysis (FIA) system is examined. The detection electrode consists of a plasticized polymeric membrane doped with 10 wt % of tridodecylmethylammonium-dinonylnaphthalene sulfonate (TDMA/DNNS) ion-exchanger salt. The pulse sequence used involves a short (1 s) galvanostatic pulse, an open-circuit pulse (0.5 s) during which the EMF of the cell is measured, and a longer (15 s) potentiostatic pulse to return the membrane to its original chemical composition. It is shown that total pulse sequence times can be optimized to yield reproducible real-time detection of injected samples of protamine and heparin at up to 20 samples/h. Further, it is shown that the same membrane detector can be employed for FIA detection of both polycations at levels ≥10 μg/mL and polyanions at levels of ≥40 μg/mL by changing the direction of the galvanostatic pulse. The methodology described may also be applicable in the detection of polyionic species at low levels in other flowing configurations, such as in liquid chromatography and capillary electrophoresis.

  8. A compact and modular x- and gamma-ray detector with a CsI scintillator and double-readout Silicon Drift Detectors

    NASA Astrophysics Data System (ADS)

    Campana, R.; Fuschino, F.; Labanti, C.; Marisaldi, M.; Amati, L.; Fiorini, M.; Uslenghi, M.; Baldazzi, G.; Bellutti, P.; Evangelista, Y.; Elmi, I.; Feroci, M.; Ficorella, F.; Frontera, F.; Picciotto, A.; Piemonte, C.; Rachevski, A.; Rashevskaya, I.; Rignanese, L. P.; Vacchi, A.; Zampa, G.; Zampa, N.; Zorzi, N.

    2016-07-01

    A future compact and modular X and gamma-ray spectrometer (XGS) has been designed and a series of proto- types have been developed and tested. The experiment envisages the use of CsI scintillator bars read out at both ends by single-cell 25 mm2 Silicon Drift Detectors. Digital algorithms are used to discriminate between events absorbed in the Silicon layer (lower energy X rays) and events absorbed in the scintillator crystal (higher energy X rays and -rays). The prototype characterization is shown and the modular design for future experiments with possible astrophysical applications (e.g. for the THESEUS mission proposed for the ESA M5 call) are discussed.

  9. The effect of guard ring on leakage current and spectroscopic performance of TlBr planar detectors

    NASA Astrophysics Data System (ADS)

    Kargar, Alireza; Kim, Hadong; Cirignano, Leonard; Shah, Kanai

    2014-09-01

    Four thallium bromide planar detectors were fabricated from materials grown at RMD Inc. The TlBr samples were prepared to investigate the effect of guard ring on device gamma-ray spectroscopy performance, and to investigate the leakage current through surface and bulk. The devices' active area in planar configuration were 4.4 × 4.4 × 1.0 mm3. In this report, the detector fabrication process is described and the resulting energy spectra are discussed. It is shown that the guard ring improves device spectroscopic performance by shielding the sensing electrode from the surface leakage current, and by making the electric filed more uniform in the active region of the device.

  10. Curved position-sensitive detector for X-ray crystallography

    NASA Astrophysics Data System (ADS)

    Izumi, T.

    1980-11-01

    A new curved position-sensitive proportional detector has been constructed for X-ray crystallography. A very hard steel wire 0.2 mm in diameter was used as a single anode wire. It was bent to a radius of 6.5 cm and was suspended elastically in a wide 160° 2θ angular aperture. An amplifier and ADC-per-cathode strip system was made in order to encode the position. The spatial resolution is better than 0.37 mm (fwhm) along the curved anode wire, and this value corresponds to an angular resolution of 0.28° in 2θ. It is shown that a thick hard anode wire is quite suitable for use as a curved position-sensitive detector.

  11. Strong mechanical adhesion of gold electroless contacts on CdZnTe deposited by alcoholic solutions

    NASA Astrophysics Data System (ADS)

    Benassi, G.; Nasi, L.; Bettelli, M.; Zambelli, N.; Calestani, D.; Zappettini, A.

    2017-02-01

    CdZnTe crystals are nowadays employed as X-ray detectors for a number of applications, such as medical imaging, security, and environmental monitoring. One of the main difficulties connected with CdZnTe-based detector processing is the poor contact adhesion that affect bonding procedures and device long term stability. We have shown that it is possible to obtain mechanically stable contacts by common electroless deposition using alcoholic solutions instead of water solutions. The contacts show blocking current-voltage characteristic that is required for obtaining spectroscopic detectors. Nanoscale-resolved chemical analysis indicated that the improved mechanical adhesion is due to a better control of the stoichiometry of the CdZnTe layer below the contact.

  12. Electronic transport in a long wavelength infrared quantum cascade detector under dark condition

    NASA Astrophysics Data System (ADS)

    Li, L.; Zhou, X. H.; Lin, T.; Li, N.; Zhu, Z. Q.; Liu, F. Q.

    2016-09-01

    We present a joint experimental and theoretical investigation on a long wavelength infrared quantum cascade detector to reveal its dark current paths. The temperature dependence of the dark current is measured. It is shown that there are two different transport mechanisms, namely resonant tunneling at low temperatures and thermal excitation at higher temperature, dominate the carrier flow, respectively. Moreover, the experimental intersubband transition energies obtained by the magneto-transport measurements matches the theoretical predictions well. With the aid of the calculated band structures, we can explain the observed oscillation phenomena of the dark current under the magnetic field very well. The obtained results provide insight into the transport properties of quantum cascade detectors thus providing a useful tool for device optimization.

  13. Diamond detectors for high energy physics experiments

    NASA Astrophysics Data System (ADS)

    Bäni, L.; Alexopoulos, A.; Artuso, M.; Bachmair, F.; Bartosik, M.; Beacham, J.; Beck, H.; Bellini, V.; Belyaev, V.; Bentele, B.; Berdermann, E.; Bergonzo, P.; Bes, A.; Brom, J.-M.; Bruzzi, M.; Cerv, M.; Chiodini, G.; Chren, D.; Cindro, V.; Claus, G.; Collot, J.; Cumalat, J.; Dabrowski, A.; D'Alessandro, R.; Dauvergne, D.; de Boer, W.; Dorfer, C.; Dünser, M.; Eremin, V.; Eusebi, R.; Forcolin, G.; Forneris, J.; Frais-Kölbl, H.; Gallin-Martel, L.; Gallin-Martel, M. L.; Gan, K. K.; Gastal, M.; Giroletti, C.; Goffe, M.; Goldstein, J.; Golubev, A.; Gorišek, A.; Grigoriev, E.; Grosse-Knetter, J.; Grummer, A.; Gui, B.; Guthoff, M.; Haughton, I.; Hiti, B.; Hits, D.; Hoeferkamp, M.; Hofmann, T.; Hosslet, J.; Hostachy, J.-Y.; Hügging, F.; Hutton, C.; Jansen, H.; Janssen, J.; Kagan, H.; Kanxheri, K.; Kasieczka, G.; Kass, R.; Kassel, F.; Kis, M.; Konovalov, V.; Kramberger, G.; Kuleshov, S.; Lacoste, A.; Lagomarsino, S.; Lo Giudice, A.; Lukosi, E.; Maazouzi, C.; Mandic, I.; Mathieu, C.; Menichelli, M.; Mikuž, M.; Morozzi, A.; Moss, J.; Mountain, R.; Murphy, S.; Muškinja, M.; Oh, A.; Oliviero, P.; Passeri, D.; Pernegger, H.; Perrino, R.; Picollo, F.; Pomorski, M.; Potenza, R.; Quadt, A.; Re, A.; Reichmann, M.; Riley, G.; Roe, S.; Sanz, D.; Scaringella, M.; Schaefer, D.; Schmidt, C. J.; Schnetzer, S.; Sciortino, S.; Scorzoni, A.; Seidel, S.; Servoli, L.; Smith, S.; Sopko, B.; Sopko, V.; Spagnolo, S.; Spanier, S.; Stenson, K.; Stone, R.; Sutera, C.; Tannenwald, B.; Taylor, A.; Traeger, M.; Tromson, D.; Trischuk, W.; Tuve, C.; Uplegger, L.; Velthuis, J.; Venturi, N.; Vittone, E.; Wagner, S.; Wallny, R.; Wang, J. C.; Weingarten, J.; Weiss, C.; Wengler, T.; Wermes, N.; Yamouni, M.; Zavrtanik, M.

    2018-01-01

    Beam test results of the radiation tolerance study of chemical vapour deposition (CVD) diamond against different particle species and energies is presented. We also present beam test results on the independence of signal size on incident particle rate in charged particle detectors based on un-irradiated and irradiated poly-crystalline CVD diamond over a range of particle fluxes from 2 kHz/cm2 to 10 MHz/cm2. The pulse height of the sensors was measured with readout electronics with a peaking time of 6 ns. In addition functionality of poly-crystalline CVD diamond 3D devices was demonstrated in beam tests and 3D diamond detectors are shown to be a promising technology for applications in future high luminosity experiments.

  14. Large Cleaner Detectors for the UCN τ Neutron Lifetime Experiment

    NASA Astrophysics Data System (ADS)

    Gonzalez, Francisco; UCNtau Collaboration

    2017-09-01

    The UCN τ experiment at Los Alamos National Laboratory measures the neutron β-decay lifetime by storing ultracold neutrons (UCNs) in a magneto-gravitational trap for holding times longer than the neutron's lifetime. Neutrons with energies above the trapping potential can escape the trap, giving rise to a systematic error. To mitigate this effect, a large polyethylene sheet is lowered into the trap to remove the high energy unbound neutrons. High energy UCN upscatter in the polyethylene sheet and leave the trap. Such a ``UCN spectrum cleaner,'' covering half the trap top, was shown to be effective in removing high-energy neutrons in previous run cycles. During this run cycle, the UCN τ collaboration has added two thermal neutron detectors on the spectrum cleaner. The new thermal neutron detectors will monitor high-energy neutrons throughout upcoming run cycles, providing important information on the neutron normalization, spectral cleaning, and heating during storage. These detectors use LiF-ZnS sheets coupled to a wavelength-shifting plastic slab, with silicon photomultipliers attached to the edges. We will present results of the light detection simulation and performance tests of these detectors.

  15. Superlattice infrared photodetector research at the Jet Propulsion Laboratory

    NASA Astrophysics Data System (ADS)

    Gunapala, S. D.; Ting, D. Z.; Rafol, S. B.; Soibel, A.; Khoshakhlagh, A.; Hill, C. J.; Höglund, L.; Keo, S. A.; Liu, J. K.; Mumolo, J. M.; Luong, E. M.; Fisher, A.

    2015-08-01

    III-V semiconductors offer a highly effective platform for the development of sophisticated heterostructure-based MWIR and LWIR detectors, as exemplified by the high-performance double heterstructure (DH) nBn, XBn, and type- II superlattice infrared detectors. A key enabling design element is the unipolar barrier, which is used to implement the complementary barrier infra-red detector (CBIRD) design for increasing the collection efficiency of photogenerated carriers, and reducing dark current generation without impeding photocurrent flow. Heterostructure superlattice detectors that make effective use of unipolar barriers have demonstrated strong reduction of generationrecombination (G-R) dark current due to Shockley-Read-Hall (SRH) processes. In the last several years we solely focused on the development of antimonide based IR detectors. Recently, we demonstrated RoA values over 14,000 Ohm cm2 for a 9.9 μm cutoff device by incorporating electron-blocking and hole-blocking unipolar barriers. This device has shown 300K BLIP operation with f/2 optics at 87 K with blackbody * of 1.1x1011 cm Hz1/2/W.

  16. Fundamental Limits on the Imaging and Polarisation Properties of Far-Infrared Detectors

    NASA Technical Reports Server (NTRS)

    Thomas, Christopher N.; Withington, Stafford; Chuss, David T.; Wollack, Edward J.; Moseley, S. Harvey

    2009-01-01

    Far-infrared bolometric detectors are used extensively in ground-based and space-borne astronomy, and thus it is important to understand their optical behaviour precisely. We have studied the intensity and polarisation response of free-space bolometers, and shown that when the size of the absorber is reduced below a wavelength, the response changes from being that of a classical optical detector to that of a few-mode antenna. We have calculated the modal content of the reception patterns, and found that for any volumetric detector having a side length of less than a wavelength, three magnetic and three electric dipoles characterize the behaviour. The size of the absorber merely determines the relative strengths of the contributions. The same formalism can be applied to thin-film absorbers, where the induced current is forced to flow in a plane. In this case, one magnetic and two electric dipoles characterize the behaviour. The ability to model easily the intensity, polarisation, and straylight characteristics of electrically-small detectors will be of great value when designing high-performance polarimetric imaging arrays.

  17. Status of HgCdTe Barrier Infrared Detectors Grown by MOCVD in Military University of Technology

    NASA Astrophysics Data System (ADS)

    Kopytko, M.; Jóźwikowski, K.; Martyniuk, P.; Gawron, W.; Madejczyk, P.; Kowalewski, A.; Markowska, O.; Rogalski, A.; Rutkowski, J.

    2016-09-01

    In this paper we present the status of HgCdTe barrier detectors with an emphasis on technological progress in metalorganic chemical vapor deposition (MOCVD) growth achieved recently at the Institute of Applied Physics, Military University of Technology. It is shown that MOCVD technology is an excellent tool for HgCdTe barrier architecture growth with a wide range of composition, donor /acceptor doping, and without post-grown annealing. The device concept of a specific barrier bandgap architecture integrated with Auger-suppression is as a good solution for high-operating temperature infrared detectors. Analyzed devices show a high performance comparable with the state-of-the-art of HgCdTe photodiodes. Dark current densities are close to the values given by "Rule 07" and detectivities of non-immersed detectors are close to the value marked for HgCdTe photodiodes. Experimental data of long-wavelength infrared detector structures were confirmed by numerical simulations obtained by a commercially available software APSYS platform. A detailed analysis applied to explain dark current plots was made, taking into account Shockley-Read-Hall, Auger, and tunneling currents.

  18. Test of the Equivalence Principle in an Einstein Elevator

    NASA Technical Reports Server (NTRS)

    Shapiro, Irwin I.; Glashow, S.; Lorenzini, E. C.; Cosmo, M. L.; Cheimets, P. N.; Finkelstein, N.; Schneps, M.

    2005-01-01

    This Annual Report illustrates the work carried out during the last grant-year activity on the Test of the Equivalence Principle in an Einstein Elevator. The activity focused on the following main topics: (1) analysis and conceptual design of a detector configuration suitable for the flight tests; (2) development of techniques for extracting a small signal from data strings with colored and white noise; (3) design of the mechanism that spins and releases the instrument package inside the cryostat; and (4) experimental activity carried out by our non-US partners (a summary is shown in this report). The analysis and conceptual design of the flight-detector (point 1) was focused on studying the response of the differential accelerometer during free fall, in the presence of errors and precession dynamics, for various detector's configurations. The goal was to devise a detector configuration in which an Equivalence Principle violation (EPV) signal at the sensitivity threshold level can be successfully measured and resolved out of a much stronger dynamics-related noise and gravity gradient. A detailed analysis and comprehensive simulation effort led us to a detector's design that can accomplish that goal successfully.

  19. Design and Fabrication of TES Detector Modules for the TIME-Pilot [CII] Intensity Mapping Experiment

    NASA Astrophysics Data System (ADS)

    Hunacek, J.; Bock, J.; Bradford, C. M.; Bumble, B.; Chang, T.-C.; Cheng, Y.-T.; Cooray, A.; Crites, A.; Hailey-Dunsheath, S.; Gong, Y.; Kenyon, M.; Koch, P.; Li, C.-T.; O'Brient, R.; Shirokoff, E.; Shiu, C.; Staniszewski, Z.; Uzgil, B.; Zemcov, M.

    2016-08-01

    We are developing a series of close-packed modular detector arrays for TIME-Pilot, a new mm-wavelength grating spectrometer array that will map the intensity fluctuations of the redshifted 157.7 \\upmu m emission line of singly ionized carbon ([CII]) from redshift z ˜ 5 to 9. TIME-Pilot's two banks of 16 parallel-plate waveguide spectrometers (one bank per polarization) will have a spectral range of 183-326 GHz and a resolving power of R ˜ 100. The spectrometers use a curved diffraction grating to disperse and focus the light on a series of output arcs, each sampled by 60 transition edge sensor (TES) bolometers with gold micro-mesh absorbers. These low-noise detectors will be operated from a 250 mK base temperature and are designed to have a background-limited NEP of {˜ }10^{-17} mathrm {W}/mathrm {Hz}^{1/2}. This proceeding presents an overview of the detector design in the context of the TIME-Pilot instrument. Additionally, a prototype detector module produced at the Microdevices Laboratory at JPL is shown.

  20. Application of CORSIKA Simulation Code to Study Lateral and Longitudinal Distribution of Fluorescence Light in Cosmic Ray Extensive Air Showers

    NASA Astrophysics Data System (ADS)

    Bagheri, Zahra; Davoudifar, Pantea; Rastegarzadeh, Gohar; Shayan, Milad

    2017-03-01

    In this paper, we used CORSIKA code to understand the characteristics of cosmic ray induced showers at extremely high energy as a function of energy, detector distance to shower axis, number, and density of secondary charged particles and the nature particle producing the shower. Based on the standard properties of the atmosphere, lateral and longitudinal development of the shower for photons and electrons has been investigated. Fluorescent light has been collected by the detector for protons, helium, oxygen, silicon, calcium and iron primary cosmic rays in different energies. So we have obtained a number of electrons per unit area, distance to the shower axis, shape function of particles density, percentage of fluorescent light, lateral distribution of energy dissipated in the atmosphere and visual field angle of detector as well as size of the shower image. We have also shown that location of highest percentage of fluorescence light is directly proportional to atomic number of elements. Also we have shown when the distance from shower axis increases and the shape function of particles density decreases severely. At the first stages of development, shower axis distance from detector is high and visual field angle is small; then with shower moving toward the Earth, angle increases. Overall, in higher energies, the fluorescent light method has more efficiency. The paper provides standard calibration lines for high energy showers which can be used to determine the nature of the particles.

  1. Passive decoy-state quantum key distribution with practical light sources

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Curty, Marcos; Ma, Xiongfeng; Qi, Bing

    2010-02-15

    Decoy states have been proven to be a very useful method for significantly enhancing the performance of quantum key distribution systems with practical light sources. Although active modulation of the intensity of the laser pulses is an effective way of preparing decoy states in principle, in practice passive preparation might be desirable in some scenarios. Typical passive schemes involve parametric down-conversion. More recently, it has been shown that phase-randomized weak coherent pulses (WCP) can also be used for the same purpose [M. Curty et al., Opt. Lett. 34, 3238 (2009).] This proposal requires only linear optics together with a simplemore » threshold photon detector, which shows the practical feasibility of the method. Most importantly, the resulting secret key rate is comparable to the one delivered by an active decoy-state setup with an infinite number of decoy settings. In this article we extend these results, now showing specifically the analysis for other practical scenarios with different light sources and photodetectors. In particular, we consider sources emitting thermal states, phase-randomized WCP, and strong coherent light in combination with several types of photodetectors, like, for instance, threshold photon detectors, photon number resolving detectors, and classical photodetectors. Our analysis includes as well the effect that detection inefficiencies and noise in the form of dark counts shown by current threshold detectors might have on the final secret key rate. Moreover, we provide estimations on the effects that statistical fluctuations due to a finite data size can have in practical implementations.« less

  2. Characterization of a hybrid energy-resolving photon-counting detector

    NASA Astrophysics Data System (ADS)

    Zang, A.; Pelzer, G.; Anton, G.; Ballabriga Sune, R.; Bisello, F.; Campbell, M.; Fauler, A.; Fiederle, M.; Llopart Cudie, X.; Ritter, I.; Tennert, F.; Wölfel, S.; Wong, W. S.; Michel, T.

    2014-03-01

    Photon-counting detectors in medical x-ray imaging provide a higher dose efficiency than integrating detectors. Even further possibilities for imaging applications arise, if the energy of each photon counted is measured, as for example K-edge-imaging or optimizing image quality by applying energy weighting factors. In this contribution, we show results of the characterization of the Dosepix detector. This hybrid photon- counting pixel detector allows energy resolved measurements with a novel concept of energy binning included in the pixel electronics. Based on ideas of the Medipix detector family, it provides three different modes of operation: An integration mode, a photon-counting mode, and an energy-binning mode. In energy-binning mode, it is possible to set 16 energy thresholds in each pixel individually to derive a binned energy spectrum in every pixel in one acquisition. The hybrid setup allows using different sensor materials. For the measurements 300 μm Si and 1 mm CdTe were used. The detector matrix consists of 16 x 16 square pixels for CdTe (16 x 12 for Si) with a pixel pitch of 220 μm. The Dosepix was originally intended for applications in the field of radiation measurement. Therefore it is not optimized towards medical imaging. The detector concept itself still promises potential as an imaging detector. We present spectra measured in one single pixel as well as in the whole pixel matrix in energy-binning mode with a conventional x-ray tube. In addition, results concerning the count rate linearity for the different sensor materials are shown as well as measurements regarding energy resolution.

  3. Optimized "detectors" for dynamics analysis in solid-state NMR

    NASA Astrophysics Data System (ADS)

    Smith, Albert A.; Ernst, Matthias; Meier, Beat H.

    2018-01-01

    Relaxation in nuclear magnetic resonance (NMR) results from stochastic motions that modulate anisotropic NMR interactions. Therefore, measurement of relaxation-rate constants can be used to characterize molecular-dynamic processes. The motion is often characterized by Markov processes using an auto-correlation function, which is assumed to be a sum of multiple decaying exponentials. We have recently shown that such a model can lead to severe misrepresentation of the real motion, when the real correlation function is more complex than the model. Furthermore, multiple distributions of motion may yield the same set of dynamics data. Therefore, we introduce optimized dynamics "detectors" to characterize motions which are linear combinations of relaxation-rate constants. A detector estimates the average or total amplitude of motion for a range of motional correlation times. The information obtained through the detectors is less specific than information obtained using an explicit model, but this is necessary because the information contained in the relaxation data is ambiguous, if one does not know the correct motional model. On the other hand, if one has a molecular dynamics trajectory, one may calculate the corresponding detector responses, allowing direct comparison to experimental NMR dynamics analysis. We describe how to construct a set of optimized detectors for a given set of relaxation measurements. We then investigate the properties of detectors for a number of different data sets, thus gaining an insight into the actual information content of the NMR data. Finally, we show an example analysis of ubiquitin dynamics data using detectors, using the DIFRATE software.

  4. High resolution micro-CT of low attenuating organic materials using large area photon-counting detector

    NASA Astrophysics Data System (ADS)

    Kumpová, I.; Vavřík, D.; Fíla, T.; Koudelka, P.; Jandejsek, I.; Jakůbek, J.; Kytýř, D.; Zlámal, P.; Vopálenský, M.; Gantar, A.

    2016-02-01

    To overcome certain limitations of contemporary materials used for bone tissue engineering, such as inflammatory response after implantation, a whole new class of materials based on polysaccharide compounds is being developed. Here, nanoparticulate bioactive glass reinforced gelan-gum (GG-BAG) has recently been proposed for the production of bone scaffolds. This material offers promising biocompatibility properties, including bioactivity and biodegradability, with the possibility of producing scaffolds with directly controlled microgeometry. However, to utilize such a scaffold with application-optimized properties, large sets of complex numerical simulations using the real microgeometry of the material have to be carried out during the development process. Because the GG-BAG is a material with intrinsically very low attenuation to X-rays, its radiographical imaging, including tomographical scanning and reconstructions, with resolution required by numerical simulations might be a very challenging task. In this paper, we present a study on X-ray imaging of GG-BAG samples. High-resolution volumetric images of investigated specimens were generated on the basis of micro-CT measurements using a large area flat-panel detector and a large area photon-counting detector. The photon-counting detector was composed of a 010× 1 matrix of Timepix edgeless silicon pixelated detectors with tiling based on overlaying rows (i.e. assembled so that no gap is present between individual rows of detectors). We compare the results from both detectors with the scanning electron microscopy on selected slices in transversal plane. It has been shown that the photon counting detector can provide approx. 3× better resolution of the details in low-attenuating materials than the integrating flat panel detectors. We demonstrate that employment of a large area photon counting detector is a good choice for imaging of low attenuating materials with the resolution sufficient for numerical simulations.

  5. Reconstruction-free sensitive wavefront sensor based on continuous position sensitive detectors.

    PubMed

    Godin, Thomas; Fromager, Michael; Cagniot, Emmanuel; Brunel, Marc; Aït-Ameur, Kamel

    2013-12-01

    We propose a new device that is able to perform highly sensitive wavefront measurements based on the use of continuous position sensitive detectors and without resorting to any reconstruction process. We demonstrate experimentally its ability to measure small wavefront distortions through the characterization of pump-induced refractive index changes in laser material. In addition, it is shown using computer-generated holograms that this device can detect phase discontinuities as well as improve the quality of sharp phase variations measurements. Results are compared to reference Shack-Hartmann measurements, and dramatic enhancements are obtained.

  6. Nonclassical light in interferometric measurements

    NASA Technical Reports Server (NTRS)

    Ansari, N. A.; Difiore, L.; Romano, R.; Solimeno, S.; Zaccaria, F.; Manko, Margarita A.; Manko, Vladimir I.

    1995-01-01

    It is shown that the even and odd coherent light and other nonclassical states of light like superposition of coherent states with different phases may replace the squeezed light in an interferometric gravitational wave detector to increase its sensitivity.

  7. Improved insulator layer for MIS devices

    NASA Technical Reports Server (NTRS)

    Miller, W. E.

    1980-01-01

    Insulating layer of supersonic conductor such as LaF sub 3 has been shown able to impart improved electrical properties to photoconductive detectors and promises to improve other metal/insulator/semiconductor (MIS) devices, e.g., MOSFET and integrated circuits.

  8. Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64.

    PubMed

    Miller, Julie M; Dewey, Marc; Vavere, Andrea L; Rochitte, Carlos E; Niinuma, Hiroyuki; Arbab-Zadeh, Armin; Paul, Narinder; Hoe, John; de Roos, Albert; Yoshioka, Kunihiro; Lemos, Pedro A; Bush, David E; Lardo, Albert C; Texter, John; Brinker, Jeffery; Cox, Christopher; Clouse, Melvin E; Lima, João A C

    2009-04-01

    Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its non-invasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective "CORE-64" trial ("Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors"). This multi-centre trial was unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows.

  9. Prototyping of petalets for the Phase-II upgrade of the silicon strip tracking detector of the ATLAS experiment

    NASA Astrophysics Data System (ADS)

    Kuehn, S.; Benítez, V.; Fernández-Tejero, J.; Fleta, C.; Lozano, M.; Ullán, M.; Lacker, H.; Rehnisch, L.; Sperlich, D.; Ariza, D.; Bloch, I.; Díez, S.; Gregor, I.; Keller, J.; Lohwasser, K.; Poley, L.; Prahl, V.; Zakharchuk, N.; Hauser, M.; Jakobs, K.; Mahboubi, K.; Mori, R.; Parzefall, U.; Bernabéu, J.; Lacasta, C.; Marco-Hernandez, R.; Rodriguez Rodriguez, D.; Santoyo, D.; Solaz Contell, C.; Soldevila Serrano, U.; Affolder, T.; Greenall, A.; Gallop, B.; Phillips, P. W.; Cindro, V.

    2018-03-01

    In the high luminosity era of the Large Hadron Collider, the instantaneous luminosity is expected to reach unprecedented values, resulting in about 200 proton-proton interactions in a typical bunch crossing. To cope with the resultant increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The ITk consists of a silicon pixel and a strip detector and exploits the concept of modularity. Prototyping and testing of various strip detector components has been carried out. This paper presents the developments and results obtained with reduced-size structures equivalent to those foreseen to be used in the forward region of the silicon strip detector. Referred to as petalets, these structures are built around a composite sandwich with embedded cooling pipes and electrical tapes for routing the signals and power. Detector modules built using electronic flex boards and silicon strip sensors are glued on both the front and back side surfaces of the carbon structure. Details are given on the assembly, testing and evaluation of several petalets. Measurement results of both mechanical and electrical quantities are shown. Moreover, an outlook is given for improved prototyping plans for large structures.

  10. 135Xe measurements with a two-element CZT-based radioxenon detector for nuclear explosion monitoring.

    PubMed

    Ranjbar, Lily; Farsoni, Abi T; Becker, Eric M

    2017-04-01

    Measurement of elevated concentrations of xenon radioisotopes ( 131m Xe, 133m Xe, 133 Xe and 135 Xe) in the atmosphere has been shown to be a very powerful method for verifying whether or not a detected explosion is nuclear in nature. These isotopes are among the few with enough mobility and with half-lives long enough to make their detection at long distances realistic. Existing radioxenon detection systems used by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) suffer from problems such as complexity, need for high maintenance and memory effect. To study the response of CdZnTe (CZT) detectors to xenon radioisotopes and investigate whether it is capable of mitigating the aforementioned issues with the current radioxenon detection systems, a prototype detector utilizing two coplanar CZT detectors was built and tested at Oregon State University. The detection system measures xenon radioisotopes through beta-gamma coincidence technique by detecting coincidence events between the two detectors. In this paper, we introduce the detector design and report our measurement results with radioactive lab sources and 135 Xe produced in the OSU TRIGA reactor. Minimum Detectable Concentration (MDC) for 135 Xe was calculated to be 1.47 ± 0.05 mBq/m 3 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. A High-Granularity Timing Detector for the Phase-II upgrade of the ATLAS calorimeter system: detector concept description and first beam test results

    NASA Astrophysics Data System (ADS)

    Lacour, D.

    2018-02-01

    The expected increase of the particle flux at the high luminosity phase of the LHC (HL-LHC) with instantaneous luminosities up to 7.5ṡ1034 cm-2s-1 will have a severe impact on the ATLAS detector performance. The pile-up is expected to increase on average to 200 interactions per bunch crossing. The reconstruction performance for electrons, photons as well as jets and transverse missing energy will be severely degraded in the end-cap and forward region. A High Granularity Timing Detector (HGTD) is proposed in front of the liquid Argon end-cap and forward calorimeters for pile-up mitigation. This device should cover the pseudo-rapidity range of 2.4 to about 4.0. Low Gain Avalanche Detectors (LGAD) technology has been chosen as it provides an internal gain good enough to reach large signal over noise ratio needed for excellent time resolution. The requirements and overall specifications of the High Granular Timing Detector at the HL-LHC will be presented as well as the conceptual design of its mechanics and electronics. Beam test results and measurements of irradiated LGAD silicon sensors, such as gain and timing resolution, will be shown.

  12. Angular oversampling with temporally offset layers on multilayer detectors in computed tomography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sjölin, Martin, E-mail: martin.sjolin@mi.physics.kth.se; Danielsson, Mats

    2016-06-15

    Purpose: Today’s computed tomography (CT) scanners operate at an increasingly high rotation speed in order to reduce motion artifacts and to fulfill the requirements of dynamic acquisition, e.g., perfusion and cardiac imaging, with lower angular sampling rate as a consequence. In this paper, a simple method for obtaining angular oversampling when using multilayer detectors in continuous rotation CT is presented. Methods: By introducing temporal offsets between the measurement periods of the different layers on a multilayer detector, the angular sampling rate can be increased by a factor equal to the number of layers on the detector. The increased angular samplingmore » rate reduces the risk of producing aliasing artifacts in the image. A simulation of a detector with two layers is performed to prove the concept. Results: The simulation study shows that aliasing artifacts from insufficient angular sampling are reduced by the proposed method. Specifically, when imaging a single point blurred by a 2D Gaussian kernel, the method is shown to reduce the strength of the aliasing artifacts by approximately an order of magnitude. Conclusions: The presented oversampling method is easy to implement in today’s multilayer detectors and has the potential to reduce aliasing artifacts in the reconstructed images.« less

  13. Study of a new design of p-N semiconductor detector array for nuclear medicine imaging by monte carlo simulation codes.

    PubMed

    Hajizadeh-Safar, M; Ghorbani, M; Khoshkharam, S; Ashrafi, Z

    2014-07-01

    Gamma camera is an important apparatus in nuclear medicine imaging. Its detection part is consists of a scintillation detector with a heavy collimator. Substitution of semiconductor detectors instead of scintillator in these cameras has been effectively studied. In this study, it is aimed to introduce a new design of P-N semiconductor detector array for nuclear medicine imaging. A P-N semiconductor detector composed of N-SnO2 :F, and P-NiO:Li, has been introduced through simulating with MCNPX monte carlo codes. Its sensitivity with different factors such as thickness, dimension, and direction of emission photons were investigated. It is then used to configure a new design of an array in one-dimension and study its spatial resolution for nuclear medicine imaging. One-dimension array with 39 detectors was simulated to measure a predefined linear distribution of Tc(99_m) activity and its spatial resolution. The activity distribution was calculated from detector responses through mathematical linear optimization using LINPROG code on MATLAB software. Three different configurations of one-dimension detector array, horizontal, vertical one sided, and vertical double-sided were simulated. In all of these configurations, the energy windows of the photopeak were ± 1%. The results show that the detector response increases with an increase of dimension and thickness of the detector with the highest sensitivity for emission photons 15-30° above the surface. Horizontal configuration array of detectors is not suitable for imaging of line activity sources. The measured activity distribution with vertical configuration array, double-side detectors, has no similarity with emission sources and hence is not suitable for imaging purposes. Measured activity distribution using vertical configuration array, single side detectors has a good similarity with sources. Therefore, it could be introduced as a suitable configuration for nuclear medicine imaging. It has been shown that using semiconductor P-N detectors such as P-NiO:Li, N-SnO2 :F for gamma detection could be possibly applicable for design of a one dimension array configuration with suitable spatial resolution of 2.7 mm for nuclear medicine imaging.

  14. High efficiency FET microwave detector design

    NASA Astrophysics Data System (ADS)

    Luglio, Juan; Ishii, Thomas Koryu

    1990-12-01

    The work is based on an assumption that very little microwave power would be consumed at a negatively biased gate of a microwave FET, yet significant detected signals would be obtained at the drain if the bias is given. By analyzing a Taylor-series expansion of the drain-current equation in the vicinity of a fixed gate-bias voltage, the bias voltage is found to maximize the second derivative of the drain current, the gate-bias voltage characteristic curve for the maximum detected drain current under a given fixed drain-bias voltage. Based on these findings, a high-efficiency microwave detector is designed, fabricated, and tested at 8.6 GHz, and it is shown that the audio power over absorbed microwave power ratio of the detector is 135 percent due to the positive gain.

  15. Characteristics of signals originating near the lithium-diffused N+ contact of high purity germanium p-type point contact detectors

    DOE PAGES

    Aguayo, E.; Amman, M.; Avignone, F. T.; ...

    2012-11-09

    A study of signals originating near the lithium-diffused n+ contact of p-type point contact (PPC) high purity germanium detectors (HPGe) is presented. The transition region between the active germanium and the fully dead layer of the n+ contact is examined. Energy depositions in this transition region are shown to result in partial charge collection. This provides a mechanism for events with a well defined energy to contribute to the continuum of the energy spectrum at lower energies. A novel technique to quantify the contribution from this source of background is introduced. Furthermore, experiments that operate germanium detectors with a verymore » low energy threshold may benefit from the methods presented herein.« less

  16. Prospects of In/CdTe X- and γ-ray detectors with MoO Ohmic contacts

    NASA Astrophysics Data System (ADS)

    Maslyanchuk, Olena L.; Solovan, Mykhailo M.; Maistruk, Eduard V.; Brus, Viktor V.; Maryanchuk, Pavlo D.; Gnatyuk, Volodymyr A.; Aoki, Toru

    2018-01-01

    The present paper analyzes the charge transport mechanisms and spectrometric properties of In/CdTe/MoOx heterojunctions prepared by magnetron sputtering of indium and molybdenum oxide thin films onto semi-insulating p-type single-crystal CdTe semiconductor, produced by Acrorad Co. Ltd. Current-voltage characteristics of the detectors at different temperatures were investigated. The charge transport mechanisms in the heterostructures under investigation were determined: the generation-recombination in the space charge region (SCR) at relatively low voltages and the space charge limited currents at high voltages. The spectra of 137Cs and 241Am isotopes taken at different applied bias voltages are presented. It is shown that the In/CdTe/MoOx structures can be used as X/γ-ray detectors in the spectrometric mode.

  17. The response of covered silicon detectors to monoenergetic gamma rays

    NASA Technical Reports Server (NTRS)

    Reier, M.

    1972-01-01

    Measurements were made of the efficiency in detecting gamma rays of a 0.3-mm, a 3-mm, and a 5-mm silicon detector covered with different absorbers. Calibrated sources covering the range from 279 KeV to 2.75 MeV were used. The need for the absorbers in order to obtain meaningful results, and their contribution to detector response at electron biases from 50 to 200 KeV, are discussed in detail. It is shown that the results are independent of the atomic number of the absorber. In addition, the role of the absorber in increasing the efficiency with increasing photon energy for low bias setting is demonstrated for the 0.3-mm crystal. Qualitative explanations are given for the shapes of all curves of efficiency versus energy at each bias.

  18. Dictionary Indexing of Electron Channeling Patterns.

    PubMed

    Singh, Saransh; De Graef, Marc

    2017-02-01

    The dictionary-based approach to the indexing of diffraction patterns is applied to electron channeling patterns (ECPs). The main ingredients of the dictionary method are introduced, including the generalized forward projector (GFP), the relevant detector model, and a scheme to uniformly sample orientation space using the "cubochoric" representation. The GFP is used to compute an ECP "master" pattern. Derivative free optimization algorithms, including the Nelder-Mead simplex and the bound optimization by quadratic approximation are used to determine the correct detector parameters and to refine the orientation obtained from the dictionary approach. The indexing method is applied to poly-silicon and shows excellent agreement with the calibrated values. Finally, it is shown that the method results in a mean disorientation error of 1.0° with 0.5° SD for a range of detector parameters.

  19. On the spatial coordinate measurement of two identical particles

    NASA Astrophysics Data System (ADS)

    Marchewka, Avi; Granot, Er'el; Schuss, Zeev

    2016-04-01

    Theoretically, the coordinate measurement of two identical particles at a point by two narrowly separated narrow detectors, is interpreted in the limit of shrinking width and separation, as the detection of two particles by a single narrow detector. Ordinarily, the ratio between probabilities of point measurements is independent of the width of the narrow detectors. We show here that not only this is not the case, but that in some scenarios the results depend on the way the dimensions shrink to zero. The ratio between the width and the separation determines the detection result. In particular, it is shown that the bunching parameter of bosons is not a well-defined physical property. Moreover, it may suggests that there is a difficulty in quantum measurement theory in the interpretation of coordinate measurement of two particles.

  20. Dual-energy micro-CT with a dual-layer, dual-color, single-crystal scintillator.

    PubMed

    Maier, Daniel Simon; Schock, Jonathan; Pfeiffer, Franz

    2017-03-20

    A wide range of X-ray imaging applications demand micrometer spatial resolution. In material science and biology especially, there is a great interest in material determination and material separation methods. Here we present a new detector design that allows the recording of a low- and a high-energy radiography image simultaneously with micrometer spatial resolution. The detector system is composed of a layered scintillator stack, two CCDs and an optical system to image the scintillator responses onto the CCDs. We used the detector system with a standard laboratory microfocus X-ray tube to prove the working principle of the system and derive important design characteristics. With the recorded and registered dual-energy data set, the material separation and determination could be shown at an X-ray tube peak energy of up to 160 keV with a spatial resolution of 12 μm. The detector design shows a great potential for further development and a wide range of possible applications.

  1. Pulse-height loss in the signal readout circuit of compound semiconductor detectors

    NASA Astrophysics Data System (ADS)

    Nakhostin, M.; Hitomi, K.

    2018-06-01

    Compound semiconductor detectors such as CdTe, CdZnTe, HgI2 and TlBr are known to exhibit large variations in their charge collection times. This paper considers the effect of such variations on the measurement of induced charge pulses by using resistive feedback charge-sensitive preamplifiers. It is shown that, due to the finite decay-time constant of the preamplifiers, the capacitive decay during the signal readout leads to a variable deficit in the measurement of ballistic signals and a digital pulse processing method is employed to correct for it. The method is experimentally examined by using sampled pulses from a TlBr detector coupled to a charge-sensitive preamplifier with 150 μs of decay-time constant and 20 % improvement in the energy resolution of the detector at 662 keV is achieved. The implications of the capacitive decay on the correction of charge-trapping effect by using depth-sensing technique are also considered.

  2. Simulation results of Pulse Shape Discrimination (PSD) for background reduction in INTEGRAL Spectrometer (SPI) germanium detectors

    NASA Technical Reports Server (NTRS)

    Slassi-Sennou, S. A.; Boggs, S. E.; Feffer, P. T.; Lin, R. P.

    1997-01-01

    Pulse Shape Discrimination (PSD) for background reduction will be used in the INTErnational Gamma Ray Astrophysics Laboratory (INTEGRAL) imaging spectrometer (SPI) to improve the sensitivity from 200 keV to 2 MeV. The observation of significant astrophysical gamma ray lines in this energy range is expected, where the dominant component of the background is the beta(sup -) decay in the Ge detectors due to the activation of Ge nuclei by cosmic rays. The sensitivity of the SPI will be improved by rejecting beta(sup -) decay events while retaining photon events. The PSD technique will distinguish between single and multiple site events. Simulation results of PSD for INTEGRAL-type Ge detectors using a numerical model for pulse shape generation are presented. The model was shown to agree with the experimental results for a narrow inner bore closed end cylindrical detector. Using PSD, a sensitivity improvement factor of the order of 2.4 at 0.8 MeV is expected.

  3. Evaluation of a Traffic Sign Detector by Synthetic Image Data for Advanced Driver Assistance Systems

    NASA Astrophysics Data System (ADS)

    Hanel, A.; Kreuzpaintner, D.; Stilla, U.

    2018-05-01

    Recently, several synthetic image datasets of street scenes have been published. These datasets contain various traffic signs and can therefore be used to train and test machine learning-based traffic sign detectors. In this contribution, selected datasets are compared regarding ther applicability for traffic sign detection. The comparison covers the process to produce the synthetic images and addresses the virtual worlds, needed to produce the synthetic images, and their environmental conditions. The comparison covers variations in the appearance of traffic signs and the labeling strategies used for the datasets, as well. A deep learning traffic sign detector is trained with multiple training datasets with different ratios between synthetic and real training samples to evaluate the synthetic SYNTHIA dataset. A test of the detector on real samples only has shown that an overall accuracy and ROC AUC of more than 95 % can be achieved for both a small rate of synthetic samples and a large rate of synthetic samples in the training dataset.

  4. Detector optimization for hand-held CsI(Tl)/HgI{sub 2} gamma-ray scintillation spectrometer applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Y.J.; Patt, B.E.; Iwanczyk, J.S.

    Gamma-ray spectrometers using mercuric iodide (HgI{sub 2}) photodetectors (PDs) coupled with CsI(Tl) scintillators have shown excellent energy resolutions and high detection efficiency at room temperature. Additionally HgI{sub 2} semiconductor PDs allow for extreme miniaturization of the detector packaging compared with photomultiplier tube (PMT) based detectors. These advantages make possible the construction of a new generation of hand-held gamma-ray spectrometers. Studies of detector optimization for this application have been undertaken. Several contact materials including hydrogen and semi-transparent metal films have been evaluated and compared for their performances and long term stability. In order to provide higher gamma-ray detection efficiency (i.e., largermore » scintillator volume), but without causing significant degradation of the excellent response achieved with the matched scintillator/PD interface, the scintillator/PD configuration has been studied. A Monte Carlo simulation model has been developed so that the spectral shape can be predicted for various scintillator shapes and surface treatments.« less

  5. Performance of the STAR Event Plane Detector

    NASA Astrophysics Data System (ADS)

    Ewigleben, Justin; Justin Ewigleben Collaboration

    2017-09-01

    The Beam Energy Scan (BES) program at the Relativistic Heavy-Ion Collider has shown hints of a critical point and first order phase transition at the BES energies. Key measurements for locating the critical point and determining the first order phase transition are limited by poor event plane resolution, limited statistics and a TPC-only centrality determination. A new event plane and collision centrality detector (EPD) is planned to replace the existing detector, the Beam-Beam Counter (BBC), with higher granularity and acceptance. The design of the EPD consists of two scintillator discs at z = +/- 3.75m from the center of STAR, covering 2.2 < η < 5.1. One quarter of a single disc was installed in STAR for the 2017 run for commissioning. In this talk we will discuss the detector performance during this commissioning run in both proton-proton collisions at √{ s = 510 } GeV and Au-Au collisions at √{sNN = 54.4 } GeV. NSF Grant 1614474.

  6. Modeling of InGaAsSb-Based Avalanche Photodetectors for 2-Micron Wavelengths

    NASA Technical Reports Server (NTRS)

    Joshi, Ravindra P.; Abedin, M. Nurul (Technical Monitor)

    2002-01-01

    The main focus of this research is to study and evaluate the potential of InGaAsSb-AlGaAsSb based 2 micron avalanche photo-detectors. The photodetector contains a separate absorption and multiplication region (SAM) structure. The analysis has mainly been done to understand the electrical response characteristics of the devices existing at NASA, and to evaluate alternate structures proposed. Calculating the current flow for the existing detector structure, on the basis of its energy band diagram, is important. This analysis also helps to find shortcomings in the existing detector structure. It is shown that, unfortunately, the existing structure cannot lead to strong multiplication or voltage dependent gain. Two alternate structures are suggested, that could overcome the inherent flaws, and help achieve improved performance. These devices are obtained through modifications of the original structure, which include varying the doping levels, and changing the thicknesses of detector sub-regions. The results of our study are presented and discussed.

  7. Host galaxy identification for binary black hole mergers with long baseline gravitational wave detectors

    NASA Astrophysics Data System (ADS)

    Howell, E. J.; Chan, M. L.; Chu, Q.; Jones, D. H.; Heng, I. S.; Lee, H.-M.; Blair, D.; Degallaix, J.; Regimbau, T.; Miao, H.; Zhao, C.; Hendry, M.; Coward, D.; Messenger, C.; Ju, L.; Zhu, Z.-H.

    2018-03-01

    The detection of black hole binary coalescence events by Advanced LIGO allows the science benefits of future detectors to be evaluated. In this paper, we report the science benefits of one or two 8 km arm length detectors based on the doubling of key parameters in an Advanced LIGO-type detector, combined with realizable enhancements. It is shown that the total detection rate for sources similar to those already detected would increase to ˜ 103-105 per year. Within 0.4 Gpc, we find that around 10 of these events would be localizable to within ˜10-1 deg2. This is sufficient to make unique associations or to rule out a direct association with the brightest galaxies in optical surveys (at r-band magnitudes of 17 or above) or for deeper limits (down to r-band magnitudes of 20) yield statistically significant associations. The combination of angular resolution and event rate would benefit precision testing of formation models, cosmic evolution, and cosmological studies.

  8. A direct reading exposure monitor for radiation processing

    NASA Astrophysics Data System (ADS)

    Kantz, A. D.; Humpherys, K. C.

    Various plastic films have been utilized to measure radiation fields. In general such films are rugged, easily handled, small enough to cause neligible perturbation on the radiation fields, and relatively inexpensive. The radiachromic materials have been shown to have advantages over other plastic fabrications in stability, reproducibility, equivalent response to electron and gamma ray processing fields, dose rate independence, and ready availability of calibration standards. Using a nylon matrix radiachromic detector, a system of direct read-out of absorbed dose has been developed to facilitate monitoring in the megarad region. When an exposed detector is inserted into the reader, the optical transmission signal is processed through an analog to digital converter. The digitized signal addresses a memory bank where the standard response curve is stored. The corresponding absorbed dose is displayed on a digital panel meter. The variation of relative sensitivity of detectors, the background of unirradiated detectors, environmental parameters, and the capacity of the memory bank are contributing factors to the total precision of the read-out system.

  9. Environmental radionuclides as contaminants of HPGe gamma-ray spectrometers: Monte Carlo simulations for Modane underground laboratory.

    PubMed

    Breier, R; Brudanin, V B; Loaiza, P; Piquemal, F; Povinec, P P; Rukhadze, E; Rukhadze, N; Štekl, I

    2018-05-21

    The main limitation in the high-sensitive HPGe gamma-ray spectrometry has been the detector background, even for detectors placed deep underground. Environmental radionuclides such as 40 K and decay products in the 238 U and 232 Th chains have been identified as the most important radioactive contaminants of construction parts of HPGe gamma-ray spectrometers. Monte Carlo simulations have shown that the massive inner and outer lead shields have been the main contributors to the HPGe-detector background, followed by aluminum cryostat, copper cold finger, detector holder and the lead ring with FET. The Monte Carlo simulated cosmic-ray background gamma-ray spectrum has been by about three orders of magnitude lower than the experimental spectrum measured in the Modane underground laboratory (4800 m w.e.), underlying the importance of using radiopure materials for the construction of ultra-low-level HPGe gamma-ray spectrometers. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Resistive Plate Chambers as thermal neutron detectors

    NASA Astrophysics Data System (ADS)

    Abbrescia, M.; Mongelli, T.; Paticchio, V.; Ranieri, A.; Trentadue, R.

    2003-09-01

    We present a construction procedure suitable to make Resistive Plate Chambers detectors sensitive also to thermal neutrons. This procedure, consisting in coating the inner surface of one of the RPC Bakelite electrodes with a mixture of linseed oil and Gd203, is very simple, cheap, and suitable to be employed for industrial, medical or de-mining applications. Here the results of extensive tests aimed to asset the performance of two prototypes of Gd-RPCs are shown. While the detection efficiency to thermal neutrons for a standard not Gd-coated RPC results to be about 0.1%, Gd-RPCs reach, in stand-alone, absolute efficiencies of about 10%, and, when two of these detectors are coupled together, more than 15%. In addition RPCs have excellent time resolution and good imaging performance. This new type, position sensitive gas detector can be operated at atmospheric pressure, is light-weighted, has low γ-ray sensitivity, and is easy to build and handle even when large areas are to be covered.

  11. Development of Ultra-Fast Silicon Detectors for 4D tracking

    NASA Astrophysics Data System (ADS)

    Staiano, A.; Arcidiacono, R.; Boscardin, M.; Dalla Betta, G. F.; Cartiglia, N.; Cenna, F.; Ferrero, M.; Ficorella, F.; Mandurrino, M.; Obertino, M.; Pancheri, L.; Paternoster, G.; Sola, V.

    2017-12-01

    In this contribution we review the progress towards the development of a novel type of silicon detectors suited for tracking with a picosecond timing resolution, the so called Ultra-Fast Silicon Detectors. The goal is to create a new family of particle detectors merging excellent position and timing resolution with GHz counting capabilities, very low material budget, radiation resistance, fine granularity, low power, insensitivity to magnetic field, and affordability. We aim to achieve concurrent precisions of ~ 10 ps and ~ 10 μm with a 50 μm thick sensor. Ultra-Fast Silicon Detectors are based on the concept of Low-Gain Avalanche Detectors, which are silicon detectors with an internal multiplication mechanism so that they generate a signal which is factor ~10 larger than standard silicon detectors. The basic design of UFSD consists of a thin silicon sensor with moderate internal gain and pixelated electrodes coupled to full custom VLSI chip. An overview of test beam data on time resolution and the impact on this measurement of radiation doses at the level of those expected at HL-LHC is presented. First I-V and C-V measurements on a new FBK sensor production of UFSD, 50 μm thick, with B and Ga, activated at two diffusion temperatures, with and without C co-implantation (in Low and High concentrations), and with different effective doping concentrations in the Gain layer, are shown. Perspectives on current use of UFSD in HEP experiments (UFSD detectors have been installed in the CMS-TOTEM Precision Protons Spectrometer for the forward physics tracking, and are currently taking data) and proposed applications for a MIP timing layer in the HL-LHC upgrade are briefly discussed.

  12. Influence of high altitude on the burning behaviour of typical combustibles and the related responses of smoke detectors in compartments

    PubMed Central

    Zeng, Yi; Fang, Jun; Zhang, Yong-Ming

    2018-01-01

    The effect of altitude on typical combustible burning and related smoke detector response signals was investigated by comparison experiments at altitudes of 40 m and 3650 m based on EN54 standard tests. Point-type light scattering photoelectric smoke detectors and ionization smoke detectors were used for four kinds of EN54 fire tests, including two kinds of smouldering fires with wood (test fire no. 2 in EN54 standard or TF2) and cotton (TF3), and two kinds of flaming fires with polyurethane (TF4) and n-heptane (TF5). First, the influence of altitude or ambient pressure on mass loss for smouldering combustion (TF2 or TF3) was insignificant, while a significant decrease in the mass burning rate was found for flaming tests (TF4 and TF5) as reported in our previous studies. Second, for photoelectric smoke detectors in flaming fire tests, the effect of altitude was similar to that of the burning rate, whereas for the ionization smoke detectors, the response signal at high altitudes was shown to be ‘enhanced’ by the detection principle of the ionization chamber, leading to an even larger value than at normal altitude for smouldering conditions. Third, to provide a reference for smoke detector design in high-altitude areas, the differences between signal speed in rising and peak values at two locations are discussed. Also, relationship between ion chamber signals and smoke optical densities are presented by utilization of an ionization smoke detector and smoke concentration meter. Moreover, a hierarchical diagram is illustrated to provide a better understanding of the effects of altitude on combustible burning behaviour and the mechanisms of detector response. PMID:29765695

  13. Influence of high altitude on the burning behaviour of typical combustibles and the related responses of smoke detectors in compartments.

    PubMed

    Tu, Ran; Zeng, Yi; Fang, Jun; Zhang, Yong-Ming

    2018-04-01

    The effect of altitude on typical combustible burning and related smoke detector response signals was investigated by comparison experiments at altitudes of 40 m and 3650 m based on EN54 standard tests. Point-type light scattering photoelectric smoke detectors and ionization smoke detectors were used for four kinds of EN54 fire tests, including two kinds of smouldering fires with wood (test fire no. 2 in EN54 standard or TF2) and cotton (TF3), and two kinds of flaming fires with polyurethane (TF4) and n -heptane (TF5). First, the influence of altitude or ambient pressure on mass loss for smouldering combustion (TF2 or TF3) was insignificant, while a significant decrease in the mass burning rate was found for flaming tests (TF4 and TF5) as reported in our previous studies. Second, for photoelectric smoke detectors in flaming fire tests, the effect of altitude was similar to that of the burning rate, whereas for the ionization smoke detectors, the response signal at high altitudes was shown to be 'enhanced' by the detection principle of the ionization chamber, leading to an even larger value than at normal altitude for smouldering conditions. Third, to provide a reference for smoke detector design in high-altitude areas, the differences between signal speed in rising and peak values at two locations are discussed. Also, relationship between ion chamber signals and smoke optical densities are presented by utilization of an ionization smoke detector and smoke concentration meter. Moreover, a hierarchical diagram is illustrated to provide a better understanding of the effects of altitude on combustible burning behaviour and the mechanisms of detector response.

  14. Performance tests of a large volume cerium tribromide (CeBr3) scintillation detector.

    PubMed

    Naqvi, A A; Khiari, F Z; Liadi, F A; Khateeb-Ur-Rehman; Isab, A A

    2016-08-01

    The response of a large cylindrical 76mm×76mm (height×diameter) cerium tribromide (CeBr3) detector was measured for prompt gamma rays. The total intrinsic activity of the CeBr3 detector, which was measured over 0.33-3.33MeV range, was found to be 0.022±0.001 counts/s/cm(3). The partial intrinsic activity ( due to (227)Ac contamination), was measured over a energy range of 1.22-2.20MeV energy, was found to be 0.007±0.001 counts/s/cm(3). Compared to intrinsic activities of LaBr3:Ce and LaCl3:Ce detectors of equivalent volume, the CeBr3 detector has 7-8 times less total intrinsic activity. The detector response for low energy prompt gamma rays was measured over 0.3-0.6MeVgamma energy range using a portable neutron generator-based Prompt Gamma Neutron Activation Analysis (PGNAA) setup. The experimental yield of boron, cadmium and mercury prompt gamma-rays was measured from water samples contaminated with 0.75-2.5wt% mercury, 0.31-2.50wt% boron, and 0.0625-0.500wt% cadmium, respectively. An excellent agreement has been observed between the calculated and experimental yields of the gamma rays. Also minimum detection limit (MDC) of the CeBr3 detector was measured for boron, cadmium and mercury samples. The CeBr3 detector has 23% smaller value of MDCB and 18% larger value of MDCCd than those of a LaBr3:Ce detector of equivalent size. This study has shown that CeBr3 detector has an excellent response for the low energy prompt gamma-rays with almost an order of magnitude low intrinsic activity as compared to LaCl3:Ce and LaBr3:Ce detectors of equivalent volume. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. A new method to detect and correct sample tilt in scanning transmission electron microscopy bright-field imaging.

    PubMed

    Brown, H G; Ishikawa, R; Sánchez-Santolino, G; Lugg, N R; Ikuhara, Y; Allen, L J; Shibata, N

    2017-02-01

    Important properties of functional materials, such as ferroelectric shifts and octahedral distortions, are associated with displacements of the positions of lighter atoms in the unit cell. Annular bright-field scanning transmission electron microscopy is a good experimental method for investigating such phenomena due to its ability to image light and heavy atoms simultaneously. To map atomic positions at the required accuracy precise angular alignment of the sample with the microscope optical axis is necessary, since misalignment (tilt) of the specimen contributes to errors in position measurements of lighter elements in annular bright-field imaging. In this paper it is shown that it is possible to detect tilt with the aid of images recorded using a central bright-field detector placed within the inner radius of the annular bright-field detector. For a probe focus near the middle of the specimen the central bright-field image becomes especially sensitive to tilt and we demonstrate experimentally that misalignment can be detected with a precision of less than a milliradian, as we also confirm in simulation. Coma in the probe, an aberration that can be misidentified as tilt of the specimen, is also investigated and it is shown how the effects of coma and tilt can be differentiated. The effects of tilt may be offset to a large extent by shifting the diffraction plane detector an amount equivalent to the specimen tilt and we provide an experimental proof of principle of this using a segmented detector system. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Review—hexagonal boron nitride epilayers: Growth, optical properties and device applications

    DOE PAGES

    Jiang, H. X.; Lin, Jing Yu

    2016-09-07

    This paper provides a brief overview on recent advances made in authors’ laboratory in epitaxial growth and optical studies of hexagonal boron nitride (h-BN) epilayers and heterostructures. Photoluminescence spectroscopy has been employed to probe the optical properties of h-BN. It was observed that the near band edge emission of h-BN is unusually high and is more than two orders of magnitude higher than that of high quality AlN epilayers. It was shown that the unique quasi-2D nature induced by the layered structure of h-BN results in high optical absorption and emission. The impurity related and near band-edge transitions in h-BNmore » epilayers were probed for materials synthesized under varying ammonia flow rates. Our results have identified that the most dominant impurities and deep level defects in h-BN epilayers are related to nitrogen vacancies. By growing h-BN under high ammonia flow rates, nitrogen vacancy related defects can be eliminated and epilayers exhibiting pure free exciton emission have been obtained. Deep UV and thermal neutron detectors based on h-BN epilayers were shown to possess unique features. Lastly, it is our belief that h-BN will lead to many potential applications from deep UV emitters and detectors, radiation detectors, to novel 2D photonic and electronic devices.« less

  17. Review—hexagonal boron nitride epilayers: Growth, optical properties and device applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jiang, H. X.; Lin, Jing Yu

    This paper provides a brief overview on recent advances made in authors’ laboratory in epitaxial growth and optical studies of hexagonal boron nitride (h-BN) epilayers and heterostructures. Photoluminescence spectroscopy has been employed to probe the optical properties of h-BN. It was observed that the near band edge emission of h-BN is unusually high and is more than two orders of magnitude higher than that of high quality AlN epilayers. It was shown that the unique quasi-2D nature induced by the layered structure of h-BN results in high optical absorption and emission. The impurity related and near band-edge transitions in h-BNmore » epilayers were probed for materials synthesized under varying ammonia flow rates. Our results have identified that the most dominant impurities and deep level defects in h-BN epilayers are related to nitrogen vacancies. By growing h-BN under high ammonia flow rates, nitrogen vacancy related defects can be eliminated and epilayers exhibiting pure free exciton emission have been obtained. Deep UV and thermal neutron detectors based on h-BN epilayers were shown to possess unique features. Lastly, it is our belief that h-BN will lead to many potential applications from deep UV emitters and detectors, radiation detectors, to novel 2D photonic and electronic devices.« less

  18. Quality assurance and quality control methodologies used within the Austrian UV monitoring network.

    PubMed

    Mario, Blumthaler

    2004-01-01

    The Austrian UVB monitoring network is operational since 1997. Nine detectors for measuring erythemally weighted solar UV irradiance are distributed over Austria in order to cover the main populated areas as well as different levels of altitude. The detectors are calibrated to indicate the UV-Index, the internationally agreed unit for erythemally weighted solar UV irradiance. Calibration is carried out in the laboratory for determination of spectral sensitivity of each detector, and under the sun for absolute comparison with a well-calibrated, double-monochromator spectroradiometer. For the conversion from detector-weighted units to erythemally weighted units a lookup table is used, which is calculated using a radiative transfer model and which reflects the dependence of the conversion on the solar zenith angle and total ozone content of the atmosphere. The uncertainty of the calibration is about +/-7%, dominated by the uncertainty of the calibration lamp for the spectroradiometer (+/-4%). The long-term stability of this type of detectors has been found to be not satisfactory. Therefore, routinely every year all detectors are completely recalibrated. Variations of the calibration factors up to +/-10% are found. Thus, during routine operation, several measures take place for quality control. The measured data are compared to results of model calculations with a radiative transfer model, where clear sky and an aerosol-free atmosphere are assumed. At each site, the UV data are also compared with data from a co-located pyranometer measuring total solar irradiance. These two radiation quantities are well correlated, especially on clear days and when the ozone content is taken into account. If suspicious measurements are found for one detector in the network, a well-calibrated travelling reference detector of the same type is set up side-by-side, allowing the identification of relative differences of approximately 3%. If necessary, a recalibration is carried out. As the main aim for the Austrian UV monitoring network is the information of the public about the actual levels of UVB irradiance, the measurement results are published on-line in the Internet (http://www.uibk.ac.at/projects/uv-index). For the previous day and backwards approximately 2 years, the distribution of maximal UVB levels over Austria is shown on a regional map. Additionally, near real-time data of most of the measurement stations are presented with a delay of usually less than half-an-hour. Together with these actually measured data there is also shown the diurnal variation of the maximal expected value of the UV-Index under ideal clear conditions.

  19. Characterization of a cable-free system based on p-type MOSFET detectors for "in vivo" entrance skin dose measurements in interventional radiology.

    PubMed

    Falco, Maria Daniela; D'Andrea, Marco; Strigari, Lidia; D'Alessio, Daniela; Quagliani, Francesco; Santoni, Riccardo; Bosco, Alessia Lo

    2012-08-01

    During radiological interventional procedures (RIP) the skin of a patient under examination may undergo a prolonged x-ray exposure, receiving a dose as high as 5 Gy in a single session. This paper describes the use of the OneDose(TM) cable-free system based on p-type MOSFET detectors to determine the entrance skin dose (ESD) at selected points during RIP. At first, some dosimetric characteristics of the detector, such as reproducibility, linearity, and fading, have been investigated using a C-arc as a source of radiation. The reference setting (RS) was: 80 kV energy, 40 cm × 40 cm field of view (FOV), current-time product of 50 mAs and source to skin distance (SSD) of 50 cm. A calibrated PMX III solid state detector was used as the reference detector and Gafchromic(®) films have been used as an independent dosimetric system to test the entire procedure. A calibration factor for the RS and correction factors as functions of tube voltage and FOV size have been determined. Reproducibility ranged from 4% at low doses (around 10 cGy as measured by the reference detector) to about 1% for high doses (around 2 Gy). The system response was found to be linear with respect to both dose measured with the PMX III and tube voltage. The fading test has shown that the maximum deviation from the optimal reading conditions (3 min after a single irradiation) was 9.1% corresponding to four irradiations in one hour read 3 min after the last exposure. The calibration factor in the RS has shown that the system response at the kV energy range is about four times larger than in the MV energy range. A fifth order and fourth order polynomial functions were found to provide correction factors for tube voltage and FOV size, respectively, in measurement settings different than the RS. ESDs measured with the system after applying the proper correction factors agreed within one standard deviation (SD) with the corresponding ESDs measured with the reference detector. The ESDs measured with Gafchromic(®) films were in agreement within one SD compared to the ESDs measured using the OneDose(TM) system, as well. The global uncertainty associated to the OneDose(TM) system established in our experiments, ranged from 7% to 10%, depending on the duration of the RIP due to fading. These values are much lower than the uncertainty commonly accepted for general diagnostic practices (20%) and of about the same size of the uncertainty recommended for practices with high risk of deterministic side effects (7%). The OneDose(TM) system has shown a high sensitivity in the kV energy range and has been found capable of measuring the entrance skin dose in RIP.

  20. First principles pulse pile-up balance equation and fast deterministic solution

    NASA Astrophysics Data System (ADS)

    Sabbatucci, Lorenzo; Fernández, Jorge E.

    2017-08-01

    Pulse pile-up (PPU) is an always present effect which introduces a distortion into the spectrum measured with radiation detectors and that worsen with the increasing emission rate of the radiation source. It is fully ascribable to the pulse handling circuitry of the detector and it is not comprised in the detector response function which is well explained by a physical model. The PPU changes both the number and the height of the recorded pulses, which are related, respectively, with the number of detected particles and their energy. In the present work, it is derived a first principles balance equation for second order PPU to obtain a post-processing correction to apply to X-ray measurements. The balance equation is solved for the particular case of rectangular pulse shape using a deterministic iterative procedure for which it will be shown the convergence. The proposed method, deterministic rectangular PPU (DRPPU), requires minimum amount of information and, as example, it is applied to a solid state Si detector with active or off-line PPU suppression circuitry. A comparison shows that the results obtained with this fast and simple approach are comparable to those from the more sophisticated procedure using precise detector pulse shapes.

  1. Output factor determination for dose measurements in axial and perpendicular planes using a silicon strip detector

    NASA Astrophysics Data System (ADS)

    Abou-Haïdar, Z.; Bocci, A.; Alvarez, M. A. G.; Espino, J. M.; Gallardo, M. I.; Cortés-Giraldo, M. A.; Ovejero, M. C.; Quesada, J. M.; Arráns, R.; Prieto, M. Ruiz; Vega-Leal, A. Pérez; Nieto, F. J. Pérez

    2012-04-01

    In this work we present the output factor measurements of a clinical linear accelerator using a silicon strip detector coupled to a new system for complex radiation therapy treatment verification. The objective of these measurements is to validate the system we built for treatment verification. The measurements were performed at the Virgin Macarena University Hospital in Seville. Irradiations were carried out with a Siemens ONCOR™ linac used to deliver radiotherapy treatment for cancer patients. The linac was operating in 6 MV photon mode; the different sizes of the fields were defined with the collimation system provided within the accelerator head. The output factor was measured with the silicon strip detector in two different layouts using two phantoms. In the first, the active area of the detector was placed perpendicular to the beam axis. In the second, the innovation consisted of a cylindrical phantom where the detector was placed in an axial plane with respect to the beam. The measured data were compared with data given by a commercial treatment planning system. Results were shown to be in a very good agreement between the compared set of data.

  2. Measurement and effects of MOSKIN detectors on skin dose during high energy radiotherapy treatment.

    PubMed

    Alnawaf, Hani; Butson, Martin; Yu, Peter K N

    2012-09-01

    During in vivo dosimetry for megavoltage X-ray beams, detectors such as diodes, Thermo luminescent dosimeters (TLD's) and MOSFET devices are placed on the patient's skin. This of course will affect the skin dose delivered during that fraction of the treatment. Whilst the overall impact on increasing skin dose would be minimal, little has been quantified concerning the level of increase in absorbed dose, in vivo dosimeters produce when placed in the beams path. To this extent, measurements have been made and analysis performed on dose changes caused by MOSKIN, MOSFET, skin dose detectors. Maximum increases in skin dose were measured as 15 % for 6 MV X-rays and 10 % for 10 MV X-rays at the active crystal of the MOSKIN device which is the thickest part of the detector. This is compared to 32 and 26 % for a standard 1 mm thick LiF TLD at 10 × 10 cm(2) field size for 6 and 10 MV X-rays respectively. Radiochromic film, EBT2 has been shown to provide a high resolution 2 dimensional map of skin dose from these detectors and measures the effects of in vivo dosimeters used for radiotherapy dose assessment.

  3. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Spagliardi, Fabio

    Liquid argon Time Projection Chambers (LArTPCs) are becoming widely used as neutrino detectors because of their image-like event reconstruction which enables precision neutrino measurements. They primarily use ionisation charge to reconstruct neutrino events. It has been shown, however, that the scintillation light emitted by liquid argon could be exploited to improve their performance. As the neutrino measurements planned in the near future require large-scale experiments, their construction presents challenges in terms of both charge and light collection. In this dissertation we present solutions developed to improve the performance in both aspects of these detectors. We present a new wire tensioningmore » measurement method that allows a remote measurement of the tension of the large number wires that constitute the TPC anode. We also discuss the development and installation of WLS-compound covered foils for the SBND neutrino detector at Fermilab, which is a technique proposed t o augment light collection in LArTPCs. This included preparing a SBND-like mesh cathode and testing it in the Run III of LArIAT, a test beam detector also located at Fermilab. Finally, we present a study aimed at understanding late scintillation light emitted by recombining positive argon ions using LArIAT data, which could affect large scale surface detectors.« less

  4. New estimates of extensive-air-shower energies on the basis of signals in scintillation detectors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Anyutin, N. V.; Dedenko, L. G., E-mail: ddn@dec1.sinp.msu.ru; Roganova, T. M.

    New formulas for estimating the energy of inclined extensive air showers (EASs) on the basis of signals in detectors by means of an original method and detailed tables of signals induced in scintillation detectors by photons, electrons, positrons, and muons and calculated with the aid of the GEANT4 code package were proposed in terms of the QGSJETII-04, EPOS LHC, and GHEISHA models. The parameters appearing in the proposed formulas were calculated by employing the CORSIKA code package. It is shown that, for showers of zenith angles in the range of 20◦–45◦, the standard constant-intensity-cut method, which is used to interpretmore » data from the Yakutsk EAS array, overestimates the shower energy by a factor of 1.2 to 1.5. It is proposed to employ the calculated VEM (Vertical Equivalent Muon) signal units of 10.8 and 11.4 MeV for, respectively, ground-based and underground scintillation detectors and to take into account the dependence of signals on the azimuthal angle of the detector position and fluctuations in the development of showers.« less

  5. In situ radiation test of silicon and diamond detectors operating in superfluid helium and developed for beam loss monitoring

    NASA Astrophysics Data System (ADS)

    Kurfürst, C.; Dehning, B.; Sapinski, M.; Bartosik, M. R.; Eisel, T.; Fabjan, C.; Rementeria, C. A.; Griesmayer, E.; Eremin, V.; Verbitskaya, E.; Zabrodskii, A.; Fadeeva, N.; Tuboltsev, Y.; Eremin, I.; Egorov, N.; Härkönen, J.; Luukka, P.; Tuominen, E.

    2015-05-01

    As a result of the foreseen increase in the luminosity of the Large Hadron Collider, the discrimination between the collision products and possible magnet quench-provoking beam losses of the primary proton beams is becoming more critical for safe accelerator operation. We report the results of ongoing research efforts targeting the upgrading of the monitoring system by exploiting Beam Loss Monitor detectors based on semiconductors located as close as possible to the superconducting coils of the triplet magnets. In practice, this means that the detectors will have to be immersed in superfluid helium inside the cold mass and operate at 1.9 K. Additionally, the monitoring system is expected to survive 20 years of LHC operation, resulting in an estimated radiation fluence of 1×1016 proton/cm2, which corresponds to a dose of about 2 MGy. In this study, we monitored the signal degradation during the in situ irradiation when silicon and single-crystal diamond detectors were situated in the liquid/superfluid helium and the dependences of the collected charge on fluence and bias voltage were obtained. It is shown that diamond and silicon detectors can operate at 1.9 K after 1×1016 p/cm2 irradiation required for application as BLMs, while the rate of the signal degradation was larger in silicon detectors than in the diamond ones. For Si detectors this rate was controlled mainly by the operational mode, being larger at forward bias voltage.

  6. What are the assets and weaknesses of HFO detectors? A benchmark framework based on realistic simulations

    PubMed Central

    Pizzo, Francesca; Bartolomei, Fabrice; Wendling, Fabrice; Bénar, Christian-George

    2017-01-01

    High-frequency oscillations (HFO) have been suggested as biomarkers of epileptic tissues. While visual marking of these short and small oscillations is tedious and time-consuming, automatic HFO detectors have not yet met a large consensus. Even though detectors have been shown to perform well when validated against visual marking, the large number of false detections due to their lack of robustness hinder their clinical application. In this study, we developed a validation framework based on realistic and controlled simulations to quantify precisely the assets and weaknesses of current detectors. We constructed a dictionary of synthesized elements—HFOs and epileptic spikes—from different patients and brain areas by extracting these elements from the original data using discrete wavelet transform coefficients. These elements were then added to their corresponding simulated background activity (preserving patient- and region- specific spectra). We tested five existing detectors against this benchmark. Compared to other studies confronting detectors, we did not only ranked them according their performance but we investigated the reasons leading to these results. Our simulations, thanks to their realism and their variability, enabled us to highlight unreported issues of current detectors: (1) the lack of robust estimation of the background activity, (2) the underestimated impact of the 1/f spectrum, and (3) the inadequate criteria defining an HFO. We believe that our benchmark framework could be a valuable tool to translate HFOs into a clinical environment. PMID:28406919

  7. The EIGER detector for low-energy electron microscopy and photoemission electron microscopy.

    PubMed

    Tinti, G; Marchetto, H; Vaz, C A F; Kleibert, A; Andrä, M; Barten, R; Bergamaschi, A; Brückner, M; Cartier, S; Dinapoli, R; Franz, T; Fröjdh, E; Greiffenberg, D; Lopez-Cuenca, C; Mezza, D; Mozzanica, A; Nolting, F; Ramilli, M; Redford, S; Ruat, M; Ruder, Ch; Schädler, L; Schmidt, Th; Schmitt, B; Schütz, F; Shi, X; Thattil, D; Vetter, S; Zhang, J

    2017-09-01

    EIGER is a single-photon-counting hybrid pixel detector developed at the Paul Scherrer Institut, Switzerland. It is designed for applications at synchrotron light sources with photon energies above 5 keV. Features of EIGER include a small pixel size (75 µm × 75 µm), a high frame rate (up to 23 kHz), a small dead-time between frames (down to 3 µs) and a dynamic range up to 32-bit. In this article, the use of EIGER as a detector for electrons in low-energy electron microscopy (LEEM) and photoemission electron microscopy (PEEM) is reported. It is demonstrated that, with only a minimal modification to the sensitive part of the detector, EIGER is able to detect electrons emitted or reflected by the sample and accelerated to 8-20 keV. The imaging capabilities are shown to be superior to the standard microchannel plate detector for these types of applications. This is due to the much higher signal-to-noise ratio, better homogeneity and improved dynamic range. In addition, the operation of the EIGER detector is not affected by radiation damage from electrons in the present energy range and guarantees more stable performance over time. To benchmark the detector capabilities, LEEM experiments are performed on selected surfaces and the magnetic and electronic properties of individual iron nanoparticles with sizes ranging from 8 to 22 nm are detected using the PEEM endstation at the Surface/Interface Microscopy (SIM) beamline of the Swiss Light Source.

  8. Fundamental x-ray interaction limits in diagnostic imaging detectors: frequency-dependent Swank noise.

    PubMed

    Hajdok, G; Battista, J J; Cunningham, I A

    2008-07-01

    A frequency-dependent x-ray Swank factor based on the "x-ray interaction" modulation transfer function and normalized noise power spectrum is determined from a Monte Carlo analysis. This factor was calculated in four converter materials: amorphous silicon (a-Si), amorphous selenium (a-Se), cesium iodide (CsI), and lead iodide (PbI2) for incident photon energies between 10 and 150 keV and various converter thicknesses. When scaled by the quantum efficiency, the x-ray Swank factor describes the best possible detective quantum efficiency (DQE) a detector can have. As such, this x-ray interaction DQE provides a target performance benchmark. It is expressed as a function of (Fourier-based) spatial frequency and takes into consideration signal and noise correlations introduced by reabsorption of Compton scatter and photoelectric characteristic emissions. It is shown that the x-ray Swank factor is largely insensitive to converter thickness for quantum efficiency values greater than 0.5. Thus, while most of the tabulated values correspond to thick converters with a quantum efficiency of 0.99, they are appropriate to use for many detectors in current use. A simple expression for the x-ray interaction DQE of digital detectors (including noise aliasing) is derived in terms of the quantum efficiency, x-ray Swank factor, detector element size, and fill factor. Good agreement is shown with DQE curves published by other investigators for each converter material, and the conditions required to achieve this ideal performance are discussed. For high-resolution imaging applications, the x-ray Swank factor indicates: (i) a-Si should only be used at low-energy (e.g., mammography); (ii) a-Se has the most promise for any application below 100 keV; and (iii) while quantum efficiency may be increased at energies just above the K edge in CsI and PbI2, this benefit is offset by a substantial drop in the x-ray Swank factor, particularly at high spatial frequencies.

  9. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nakahira, S.; Yamaoka, K.; Yoshida, A.

    We propose to provide a gamma-ray burst monitor (GBM) for the CALET mission to monitor gamma-ray bursts (GRBs) together with the CALET Imaging Calorimeter detector. The major purpose is to derive a wide-band energy spectrum of GRBs over an unprecedented 9 decades of energy (from a few keV to a few TeV) in combination with the CALET tower detector. Hence it is desirable to have the CALET-GBM covering an energy range from a few keV to about 20 MeV to avoid a gap in the observational energy bands. The design of GBM is underway to fulfill this requirement. The currentmore » detector candidate is BGO, and a LaBr (Ce) scintillator which has a superior energy resolution to that of NaI(Tl). In this paper, design and expected performance of the CALET-GBM is shown.« less

  10. Optimum testing of multiple hypotheses in quantum detection theory

    NASA Technical Reports Server (NTRS)

    Yuen, H. P.; Kennedy, R. S.; Lax, M.

    1975-01-01

    The problem of specifying the optimum quantum detector in multiple hypotheses testing is considered for application to optical communications. The quantum digital detection problem is formulated as a linear programming problem on an infinite-dimensional space. A necessary and sufficient condition is derived by the application of a general duality theorem specifying the optimum detector in terms of a set of linear operator equations and inequalities. Existence of the optimum quantum detector is also established. The optimality of commuting detection operators is discussed in some examples. The structure and performance of the optimal receiver are derived for the quantum detection of narrow-band coherent orthogonal and simplex signals. It is shown that modal photon counting is asymptotically optimum in the limit of a large signaling alphabet and that the capacity goes to infinity in the absence of a bandwidth limitation.

  11. Cargo Container Imaging with Gaseous Detectors

    NASA Astrophysics Data System (ADS)

    Forest, Tony

    2006-10-01

    The gas electron multiplier (GEM) , developed at CERN by Fabio Sauli, represents the latest innovation in micropattern gaseous detectors and has been utilized as a preamplification stage in applications ranging from fundamental physics experiments to medical imaging. Although cargo container inspection systems are currently in place using gamma-rays or X-rays, they are predominantly designed with a resolution to detect contraband. Current imaging systems also suffer from false alarms due to naturally radioactive cargo when radiation portal monitors are used for passive detection of nuclear materials. Detection of small shielded radioactive elements is even more problematic. Idaho State University has been developing a system to image cargo containers in order to detect small shielded radioactive cargo. The possible application of an imaging system with gas electron multiplication will be shown along with preliminary images using gaseous detectors instead of the scintillators currently in use.

  12. The response of covered silicon detectors to monoenergetic gamma rays.

    NASA Technical Reports Server (NTRS)

    Reier, M.

    1972-01-01

    Measurements have been made of the efficiency in detecting gamma rays of a 0.3-mm-, 3-mm-, and 5-mm-thick silicon detector covered with different absorbers. Calibrated sources over the range from 279 keV to 2.75 MeV were used. The need for the absorbers to obtain meaningful results and their contribution to the response of the detectors at electron biases from 50 to 200 keV are discussed in detail. It is shown that the results are virtually independent of the atomic number of the absorber. In addition, the role of the absorber in increasing the efficiency with increasing photon energy for low bias settings is demonstrated for the 0.3-mm crystal. Qualitative explanations are given for the shapes of all curves of efficiency versus energy at each bias.

  13. Gas mixture studies for streamer operated Resistive Plate Chambers

    NASA Astrophysics Data System (ADS)

    Paoloni, A.; Longhin, A.; Mengucci, A.; Pupilli, F.; Ventura, M.

    2016-06-01

    Resistive Plate Chambers operated in streamer mode are interesting detectors in neutrino and astro-particle physics applications (like OPERA and ARGO experiments). Such experiments are typically characterized by large area apparatuses with no stringent requirements on detector aging and rate capabilities. In this paper, results of cosmic ray tests performed on a RPC prototype using different gas mixtures are presented, the principal aim being the optimization of the TetraFluoroPropene concentration in Argon-based mixtures. The introduction of TetraFluoroPropene, besides its low Global Warming Power, is helpful because it simplifies safety requirements allowing to remove also isobutane from the mixture. Results obtained with mixtures containing SF6, CF4, CO2, N2 and He are also shown, presented both in terms of detectors properties (efficiency, multiple-streamer probability and time resolution) and in terms of streamer characteristics.

  14. Microdosimetry and Katz's track structure theory. I. One-hit detectors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zaider, M.

    1990-10-01

    A microdosimetric treatment of the response of one-hit detectors to radiation is formulated and compared with the model proposed by R. Katz, S. C. Sharma, and M. Homayoonfar within the framework of their track-structure theory. It is shown that radial dose distributions (on which the track structure theory is based) are generally poor substitutes for the exact microdosimetric distributions except when (a) the target is much larger than the radial extent of the track or (b) the effective specific energy in the target (alpha z) is negligibly small. Since neither one of these conditions is generally satisfied, it is suggestedmore » that a meaningful search for one-hit detectors be based on a microdosimetric description of the stochastics of energy deposition. An analysis of the phi x-174 bacteriophage inactivation data is presented.« less

  15. DS/LPI autocorrelation detection in noise plus random-tone interference. [Direct Sequence Low-Probabilty of Intercept

    NASA Technical Reports Server (NTRS)

    Hinedi, S.; Polydoros, A.

    1988-01-01

    The authors present and analyze a frequency-noncoherent two-lag autocorrelation statistic for the wideband detection of random BPSK signals in noise-plus-random-multitone interference. It is shown that this detector is quite robust to the presence or absence of interference and its specific parameter values, contrary to the case of an energy detector. The rule assumes knowledge of the data rate and the active scenario under H0. It is concluded that the real-time autocorrelation domain and its samples (lags) are a viable approach for detecting random signals in dense environments.

  16. On the prospects of application and development of solid-state photomultipliers for the task of analog detecting of pulsed optical signals

    NASA Astrophysics Data System (ADS)

    Bogdanov, S. V.; Kolobov, N. A.; Levin, E. V.; Pozdnyakov, Y. I.; Shubin, V. E.; Shushakov, D. A.; Sitarsky, K. Yu.; Torgovnikov, R. A.

    2018-02-01

    In this paper, we analyze the influence of the crosstalk level and the dynamic range on the basic characteristics of a silicon solid-state photomultiplier and demonstrate their importance for detecting of optical signals with backlight illumination, in particular, for LIDAR application. Experimental results obtained in the study of threshold and fluctuation parameters of detectors with different levels of crosstalk and dynamic range are presented. It is shown that the detector design combining a high dynamic range with a small crosstalk gives a noticeable advantage in such applications.

  17. Preliminary On-Orbit Neutron Dose Equivalent and Energy Spectrum Results from the ISS-RAD Fast Neutron Detector (FND)

    NASA Technical Reports Server (NTRS)

    Semones, Edward; Leitgab, Martin

    2016-01-01

    The ISS-RAD instrument was activated on ISS on February 1st, 2016. Integrated in ISS-RAD, the Fast Neutron Detector (FND) performs, for the first time on ISS, routine and precise direct neutron measurements between 0.5 and 8 MeV. Preliminary results for neutron dose equivalent and neutron flux energy distributions from online/on-board algorithms and offline ground analyses will be shown, along with comparisons to simulated data and previously measured neutron spectral data. On-orbit data quality and pre-launch analysis validation results will be discussed as well.

  18. Fast gas spectroscopy using pulsed quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Beyer, T.; Braun, M.; Lambrecht, A.

    2003-03-01

    Laser spectroscopy has found many industrial applications, e.g., control of automotive exhaust and process monitoring. The midinfrared region is of special interest because it has stronger absorption lines compared to the near infrared (NIR). However, in the NIR high quality reliable laser sources, detectors, and passive optical components are available. A quantum cascade laser could change this situation if fundamental advantages can be exploited with compact and reliable systems. It will be shown that, using pulsed lasers and available fast detectors, lower residual sensitivity levels than in corresponding NIR systems can be achieved. The stability is sufficient for industrial applications.

  19. Vehicle and cargo container inspection system for drugs

    NASA Astrophysics Data System (ADS)

    Verbinski, Victor V.; Orphan, Victor J.

    1999-06-01

    A vehicle and cargo container inspection system has been developed which uses gamma-ray radiography to produce digital images useful for detection of drugs and other contraband. The system is comprised of a 1 Ci Cs137 gamma-ray source collimated into a fan beam which is aligned with a linear array of NaI gamma-ray detectors located on the opposite side of the container. The NaI detectors are operated in the pulse-counting mode. A digital image of the vehicle or container is obtained by moving the aligned source and detector array relative to the object. Systems have been demonstrated in which the object is stationary (source and detector array move on parallel tracks) and in which the object moves past a stationary source and detector array. Scanning speeds of ˜30 cm/s with a pixel size (at the object) of ˜1 cm have been achieved. Faster scanning speeds of ˜2 m/s have been demonstrated on railcars with more modest spatial resolution (4 cm pixels). Digital radiographic images are generated from the detector count rates. These images, recorded on a PC-based data acquisition and display system, are shown from several applications: 1) inspection of trucks and containers at a border crossing, 2) inspection of railcars at a border crossing, 3) inspection of outbound cargo containers for stolen automobiles, and 4) inspection of trucks and cars for terrorist bombs.

  20. Detection of orthopaedic implants by airport metal detectors.

    PubMed

    Obremskey, William T; Austin, Tom; Crosby, Colin; Driver, Robin; Kurtz, Will; Shuler, Franklin; Kregor, Philip

    2007-02-01

    To report the effect of patient's body mass index (BMI), implant type, size, location, number, and material on detection by certified Transportation Security Administration (TSA) and Federal Aviation Administration (FAA) airport metal detectors set to today's standard sensitivity. Retrospective clinical study. Level 1 university trauma center. Ninety-six regularly scheduled trauma clinic patients with a wide variety of orthopaedic implants were enrolled in the study from August 2004 through December 2004. Patients walked through an airport arch metal detector and were also wanded with a handheld metal detector. Detection of implants by arch detector or wand was recorded. We also gathered information regarding BMI, location of implants, type, metal composition, and size. All unilateral prostheses (8/8) and bilateral prostheses (1/1) were detected. Subjects with 4 or fewer screws and no other implants were never detected by the arch metal detector (0/7). For the remaining 78 subjects, the 2 best predictors of detection by the arch were having plates of length >10 holes and having titanium nails (P < 0.001 for each predictor, Wald's test for effects in a logistic model). Prostheses, plates of length >10 holes, and titanium nails were the best predictors of detection by the arch. These 3 factors accounted for 42 of the 43 detections by the arch. Body mass index was not shown to affect detectability of orthopaedic implants.

  1. Using convolutional neural networks to estimate time-of-flight from PET detector waveforms

    NASA Astrophysics Data System (ADS)

    Berg, Eric; Cherry, Simon R.

    2018-01-01

    Although there have been impressive strides in detector development for time-of-flight positron emission tomography, most detectors still make use of simple signal processing methods to extract the time-of-flight information from the detector signals. In most cases, the timing pick-off for each waveform is computed using leading edge discrimination or constant fraction discrimination, as these were historically easily implemented with analog pulse processing electronics. However, now with the availability of fast waveform digitizers, there is opportunity to make use of more of the timing information contained in the coincident detector waveforms with advanced signal processing techniques. Here we describe the application of deep convolutional neural networks (CNNs), a type of machine learning, to estimate time-of-flight directly from the pair of digitized detector waveforms for a coincident event. One of the key features of this approach is the simplicity in obtaining ground-truth-labeled data needed to train the CNN: the true time-of-flight is determined from the difference in path length between the positron emission and each of the coincident detectors, which can be easily controlled experimentally. The experimental setup used here made use of two photomultiplier tube-based scintillation detectors, and a point source, stepped in 5 mm increments over a 15 cm range between the two detectors. The detector waveforms were digitized at 10 GS s-1 using a bench-top oscilloscope. The results shown here demonstrate that CNN-based time-of-flight estimation improves timing resolution by 20% compared to leading edge discrimination (231 ps versus 185 ps), and 23% compared to constant fraction discrimination (242 ps versus 185 ps). By comparing several different CNN architectures, we also showed that CNN depth (number of convolutional and fully connected layers) had the largest impact on timing resolution, while the exact network parameters, such as convolutional filter size and number of feature maps, had only a minor influence.

  2. Magnetic field influences on the lateral dose response functions of photon-beam detectors: MC study of wall-less water-filled detectors with various densities.

    PubMed

    Looe, Hui Khee; Delfs, Björn; Poppinga, Daniela; Harder, Dietrich; Poppe, Björn

    2017-06-21

    The distortion of detector reading profiles across photon beams in the presence of magnetic fields is a developing subject of clinical photon-beam dosimetry. The underlying modification by the Lorentz force of a detector's lateral dose response function-the convolution kernel transforming the true cross-beam dose profile in water into the detector reading profile-is here studied for the first time. The three basic convolution kernels, the photon fluence response function, the dose deposition kernel, and the lateral dose response function, of wall-less cylindrical detectors filled with water of low, normal and enhanced density are shown by Monte Carlo simulation to be distorted in the prevailing direction of the Lorentz force. The asymmetric shape changes of these convolution kernels in a water medium and in magnetic fields of up to 1.5 T are confined to the lower millimetre range, and they depend on the photon beam quality, the magnetic flux density and the detector's density. The impact of this distortion on detector reading profiles is demonstrated using a narrow photon beam profile. For clinical applications it appears as favourable that the magnetic flux density dependent distortion of the lateral dose response function, as far as secondary electron transport is concerned, vanishes in the case of water-equivalent detectors of normal water density. By means of secondary electron history backtracing, the spatial distribution of the photon interactions giving rise either directly to secondary electrons or to scattered photons further downstream producing secondary electrons which contribute to the detector's signal, and their lateral shift due to the Lorentz force is elucidated. Electron history backtracing also serves to illustrate the correct treatment of the influences of the Lorentz force in the EGSnrc Monte Carlo code applied in this study.

  3. Bringing SARA to School.

    ERIC Educational Resources Information Center

    Gavin, Thomas A.

    2000-01-01

    Well-designed problem-solving plans have something metal detectors and security cameras lack: proof of success. SARA, an acronym for Scanning, Analysis, Response, and Assessment, was shown to increase school safety in districts in Charlotte, North Carolina, and St. Petersburg, Florida. Program workings are explained. (MLH)

  4. Hydrodynamics and long range correlations

    NASA Astrophysics Data System (ADS)

    Bialas, A.; Zalewski, K.

    2011-04-01

    It is shown that the recently proposed method of studying the long-range correlations in multiparticle production can be effectively used to verify the hydrodynamic nature of the longitudinal expansion of the partonic system created in the collision. The case of ALICE detector is explicitly considered.

  5. Hexagonal boron nitride neutron detectors with high detection efficiencies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Maity, A.; Grenadier, S. J.; Li, J.

    Here, neutron detectors fabricated from 10B enriched hexagonal boron nitride (h- 10BN or h-BN) epilayers have demonstrated the highest thermal neutron detection efficiency among solid-state neutron detectors to date at about 53%. In this work, photoconductive-like vertical detectors with a detection area of 1 × 1 mm 2 were fabricated from 50 μm thick free-standing h-BN epilayers using Ni/Au and Ti/Al bilayers as ohmic contacts. Leakage currents, mobility-lifetime (μτ) products under UV photoexcitation, and neutron detection efficiencies have been measured for a total of 16 different device configurations. The results have unambiguously identified that detectors incorporating the Ni/Au bilayer onmore » both surfaces as ohmic contacts and using the negatively biased top surface for neutron irradiation are the most desired device configurations. It was noted that high growth temperatures of h- 10BN epilayers on sapphire substrates tend to yield a higher concentration of oxygen impurities near the bottom surface, leading to a better device performance by the chosen top surface for irradiation than by the bottom. Preferential scattering of oxygen donors tends to reduce the mobility of holes more than that of electrons, making the biasing scheme with the ability of rapidly extracting holes at the irradiated surface while leaving the electrons to travel a large average distance inside the detector at a preferred choice. When measured against a calibrated 6LiF filled micro-structured semiconductor neutron detector, it was shown that the optimized configuration has pushed the detection efficiency of h-BN neutron detectors to 58%. These detailed studies also provided a better understanding of growth-mediated impurities in h-BN epilayers and their effects on the charge collection and neutron detection efficiencies.« less

  6. Hexagonal boron nitride neutron detectors with high detection efficiencies

    NASA Astrophysics Data System (ADS)

    Maity, A.; Grenadier, S. J.; Li, J.; Lin, J. Y.; Jiang, H. X.

    2018-01-01

    Neutron detectors fabricated from 10B enriched hexagonal boron nitride (h-10BN or h-BN) epilayers have demonstrated the highest thermal neutron detection efficiency among solid-state neutron detectors to date at about 53%. In this work, photoconductive-like vertical detectors with a detection area of 1 × 1 mm2 were fabricated from 50 μm thick free-standing h-BN epilayers using Ni/Au and Ti/Al bilayers as ohmic contacts. Leakage currents, mobility-lifetime (μτ) products under UV photoexcitation, and neutron detection efficiencies have been measured for a total of 16 different device configurations. The results have unambiguously identified that detectors incorporating the Ni/Au bilayer on both surfaces as ohmic contacts and using the negatively biased top surface for neutron irradiation are the most desired device configurations. It was noted that high growth temperatures of h-10BN epilayers on sapphire substrates tend to yield a higher concentration of oxygen impurities near the bottom surface, leading to a better device performance by the chosen top surface for irradiation than by the bottom. Preferential scattering of oxygen donors tends to reduce the mobility of holes more than that of electrons, making the biasing scheme with the ability of rapidly extracting holes at the irradiated surface while leaving the electrons to travel a large average distance inside the detector at a preferred choice. When measured against a calibrated 6LiF filled micro-structured semiconductor neutron detector, it was shown that the optimized configuration has pushed the detection efficiency of h-BN neutron detectors to 58%. These detailed studies also provided a better understanding of growth-mediated impurities in h-BN epilayers and their effects on the charge collection and neutron detection efficiencies.

  7. Redesigned β γ radioxenon detector

    NASA Astrophysics Data System (ADS)

    Cooper, Matthew W.; McIntyre, Justin I.; Bowyer, Ted W.; Carman, April J.; Hayes, James C.; Heimbigner, Tom R.; Hubbard, Charles W.; Lidey, Lance; Litke, Kevin E.; Morris, Scott J.; Ripplinger, Michael D.; Suarez, Reynold; Thompson, Robert

    2007-08-01

    The Automated Radio-xenon Sampler/Analyzer (ARSA), designed by Pacific Northwest National Laboratory (PNNL) collects and detects several radioxenon isotopes, and is used to monitor underground nuclear explosions. The ARSA is very sensitive to 133Xe, 131mXe, 133mXe, and 135Xe (<1 mBq/SCM) [M. Auera et al., Wernspergera, Appl. Radiat. 6 (2004) 60] through use of its compact high efficiency β-γ coincidence detector. For this reason, it is an excellent treaty monitoring system and it can be used as an environmental sampling device as well. Field testing of the ARSA has shown it to be both robust and reliable, but the nuclear detector requires a detailed photomultiplier tube (PMT) gain matching regime difficult to implement in a field environment. Complexity is a problem from a maintenance and quality assurance/quality control (QA/QC) standpoint, and efforts to reduce these issues have led to development of a simplified β-γ coincident detector. The new design reduces the number of PMT's and the complexity of the calibration needed in comparison to the old design. New scintillation materials (NaI(Tl), CsI(Na), and CsI(Tl)) were investigated and a comparison of three different gamma sensitive well detectors has been completed. A new plastic-scintillator gas cell was constructed and a new method of forming the scintillator gas cell was developed. The simplified detector system compares favorably with the original ARSA design in spectral resolution and efficiency and is significantly easier to set up and calibrate. The new materials and configuration allow the resulting β-γ coincidence detector to maintain the overall performance of the ARSA type β-γ detector while simplifying the design.

  8. Hexagonal boron nitride neutron detectors with high detection efficiencies

    DOE PAGES

    Maity, A.; Grenadier, S. J.; Li, J.; ...

    2018-01-23

    Here, neutron detectors fabricated from 10B enriched hexagonal boron nitride (h- 10BN or h-BN) epilayers have demonstrated the highest thermal neutron detection efficiency among solid-state neutron detectors to date at about 53%. In this work, photoconductive-like vertical detectors with a detection area of 1 × 1 mm 2 were fabricated from 50 μm thick free-standing h-BN epilayers using Ni/Au and Ti/Al bilayers as ohmic contacts. Leakage currents, mobility-lifetime (μτ) products under UV photoexcitation, and neutron detection efficiencies have been measured for a total of 16 different device configurations. The results have unambiguously identified that detectors incorporating the Ni/Au bilayer onmore » both surfaces as ohmic contacts and using the negatively biased top surface for neutron irradiation are the most desired device configurations. It was noted that high growth temperatures of h- 10BN epilayers on sapphire substrates tend to yield a higher concentration of oxygen impurities near the bottom surface, leading to a better device performance by the chosen top surface for irradiation than by the bottom. Preferential scattering of oxygen donors tends to reduce the mobility of holes more than that of electrons, making the biasing scheme with the ability of rapidly extracting holes at the irradiated surface while leaving the electrons to travel a large average distance inside the detector at a preferred choice. When measured against a calibrated 6LiF filled micro-structured semiconductor neutron detector, it was shown that the optimized configuration has pushed the detection efficiency of h-BN neutron detectors to 58%. These detailed studies also provided a better understanding of growth-mediated impurities in h-BN epilayers and their effects on the charge collection and neutron detection efficiencies.« less

  9. Recent advances in targeted endoscopic imaging: Early detection of gastrointestinal neoplasms

    PubMed Central

    Kwon, Yong-Soo; Cho, Young-Seok; Yoon, Tae-Jong; Kim, Ho-Shik; Choi, Myung-Gyu

    2012-01-01

    Molecular imaging has emerged as a new discipline in gastrointestinal endoscopy. This technology encompasses modalities that can visualize disease-specific morphological or functional tissue changes based on the molecular signature of individual cells. Molecular imaging has several advantages including minimal damage to tissues, repetitive visualization, and utility for conducting quantitative analyses. Advancements in basic science coupled with endoscopy have made early detection of gastrointestinal cancer possible. Molecular imaging during gastrointestinal endoscopy requires the development of safe biomarkers and exogenous probes to detect molecular changes in cells with high specificity anda high signal-to-background ratio. Additionally, a high-resolution endoscope with an accurate wide-field viewing capability must be developed. Targeted endoscopic imaging is expected to improve early diagnosis and individual therapy of gastrointestinal cancer. PMID:22442742

  10. Multivariate evoked response detection based on the spectral F-test.

    PubMed

    Rocha, Paulo Fábio F; Felix, Leonardo B; Miranda de Sá, Antonio Mauricio F L; Mendes, Eduardo M A M

    2016-05-01

    Objective response detection techniques, such as magnitude square coherence, component synchrony measure, and the spectral F-test, have been used to automate the detection of evoked responses. The performance of these detectors depends on both the signal-to-noise ratio (SNR) and the length of the electroencephalogram (EEG) signal. Recently, multivariate detectors were developed to increase the detection rate even in the case of a low signal-to-noise ratio or of short data records originated from EEG signals. In this context, an extension to the multivariate case of the spectral F-test detector is proposed. The performance of this technique is assessed using Monte Carlo. As an example, EEG data from 12 subjects during photic stimulation is used to demonstrate the usefulness of the proposed detector. The multivariate method showed detection rates consistently higher than those ones when only one signal was used. It is shown that the response detection in EEG signals with the multivariate technique was statistically significant if two or more EEG derivations were used. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. A full range detector for the HIRRBS high resolution RBS magnetic spectrometer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Skala, Wayne G.; Haberl, Arthur W.; Bakhru, Hassaram

    2013-04-19

    The UAlbany HIRRBS (High Resolution RBS) system has been updated for better use in rapid analysis. The focal plane detector now covers the full range from U down to O using a linear stepper motor to translate the 1-cm detector across the 30-cm range. Input is implemented with zero-back-angle operation in all cases. The chamber has been modified to allow for quick swapping of sample holders, including a channeling goniometer. A fixed standard surface-barrier detector allows for normal RBS simultaneously with use of the magnetic spectrometer. The user can select a region on the standard spectrum or can select anmore » element edge or an energy point for collection of the expanded spectrum portion. The best resolution currently obtained is about 2-to-3 keV, probably representing the energy width of the incoming beam. Calibration is maintained automatically for any spectrum portion and any beam energy from 1.0 to 3.5 MeV. Element resolving power, sensitivity and depth resolution are shown using several examples. Examples also show the value of simultaneous conventional RBS.« less

  12. Progress in MOCVD growth of HgCdTe epilayers for HOT infrared detectors

    NASA Astrophysics Data System (ADS)

    Kebłowski, A.; Gawron, W.; Martyniuk, P.; Stepień, D.; Kolwas, K.; Piotrowski, J.; Madejczyk, P.; Kopytko, M.; Piotrowski, A.; Rogalski, A.

    2016-05-01

    In this paper we present progress in MOCVD growth of (100) HgCdTe epilayers achieved recently at the Institute of Applied Physics, Military University of Technology and Vigo System S.A. It is shown that MOCVD technology is an excellent tool in fabrication of different HgCdTe detector structures with a wide range of composition, donor/acceptor doping and without post grown annealing. Particular progress has been achieved in the growth of (100) HgCdTe epilayers for long wavelength infrared photoconductors operated in HOT conditions. The (100) HgCdTe photoconductor optimized for 13-μm attain detectivity equal to 6.5x109 Jones and therefore outperform its (111) counterpart. The paper also presents technological progress in fabrication of MOCVD-grown (111) HgCdTe barrier detectors. The barrier device performance is comparable with state-of-the-art of HgCdTe photodiodes. The detectivity of HgCdTe detectors is close to the value marked HgCdTe photodiodes. Dark current densities are close to the values given by "Rule 07".

  13. Recent Results of the Telescope Array Experiment

    NASA Astrophysics Data System (ADS)

    Ivanov, Dmitri

    2015-04-01

    The Telescope Array (TA) is the largest cosmic ray experiment in the northern hemisphere and covers 10 PeV to 100 EeV range. TA is a hybrid detector that uses air fluorescence detectors combined with a ground array. TA consists of 507 plastic scintillation counters on a 1.2km square grid, overlooked by 3 fluorescence detector stations, and measures cosmic rays above 1 EeV. TA has collected 6.5 years of data. Results from the TA low energy extension (TALE), which sees cosmic rays down to 10 PeV, will also be shown. This contribution will consist of three parts. First, we will present the cosmic ray energy spectrum measured over 4 decades in energy. Next, we will discuss the latest results of the measurements of cosmic ray mass composition by the TA fluorescence detectors. Finally, we will show the latest results of the TA anisotropy measurements at the highest energies, where we have seen a concentration of events, called the ``hotspot,'' centered in the Ursa Major. For the Telescope Array Collaboration. Done...processed 1261 records...10:46:59 Beginning APS data extraction...10:47:48

  14. G-index: A new metric to describe dynamic refractive index effects in HPLC absorbance detection.

    PubMed

    Kraiczek, Karsten G; Rozing, Gerard P; Zengerle, Roland

    2018-09-01

    High performance liquid chromatography (HPLC) with a solvent gradient and absorbance detection is one of the most widely used methods in analytical chemistry. The observed absorbance baseline is affected by the changes in the refractive index (RI) of the mobile phase. Near the limited of detection, this complicates peak quantitation. The general aspects of these RI-induced apparent absorbance effects are discussed. Two different detectors with fundamentally different optics and flow cell concepts, a variable-wavelength detector equipped with a conventional flow cell and a diode-array detector equipped with a liquid core waveguide flow cell, are compared with respect to their RI behavior. A simple method to separate static - partly unavoidable - RI effects from dynamic RI effects is presented. It is shown that the dynamic RI behavior of an absorbance detector can be well described using a single, relatively easy-to-determine metric called the G-index. The G-index is typically in the order of a few seconds and its sign depends on the optical flow cell concept. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Degree of Response to Homeopathic Potencies Correlates with Dipole Moment Size in Molecular Detectors: Implications for Understanding the Fundamental Nature of Serially Diluted and Succussed Solutions.

    PubMed

    Cartwright, Steven J

    2018-02-01

     The use of solvatochromic dyes to investigate homeopathic potencies holds out the promise of understanding the nature of serially succussed and diluted solutions at a fundamental physicochemical level. Recent studies have shown that a range of different dyes interact with potencies and, moreover, the nature of the interaction is beginning to allow certain specific characteristics of potencies to be delineated.  The study reported in this article takes previous investigations further and aims to understand more about the nature of the interaction between potencies and solvatochromic dyes. To this end, the UV-visible spectra of a wide range of potential detectors of potencies have been examined using methodologies previously described.  Results presented demonstrate that solvatochromic dyes are a sub-group of a larger class of compounds capable of demonstrating interactions with potencies. In particular, amino acids containing an aromatic bridge also show marked optical changes in the presence of potencies. Several specific features of molecular detectors can now be shown to be necessary for significant interactions with homeopathic potencies. These include systems with a large dipole moment, electron delocalisation, polarizability and molecular rigidity.  Analysis of the optical changes occurring on interaction with potencies suggests that in all cases potencies increase the polarity of molecular detectors to a degree that correlates with the size of the compound's permanent or ground dipole moment. These results can be explained by inferring that potencies themselves have polarity. Possible candidates for the identity of potencies, based on these and previously reported results, are discussed. The Faculty of Homeopathy.

  16. Removal of Long-Lived Radon Daughters by Electropolishing Thin Layers of Stainless Steel

    NASA Astrophysics Data System (ADS)

    White, James; Schnee, Richard; Bunker, Raymond; Bowles, Michael; Cushman, Priscilla; Epland, Matthew; Pepin, Mark; Guiseppe, Vince

    2012-10-01

    Long-lived alpha and beta emitters in the Radon decay chain on detector surfaces may be limiting background in many experiments attempting to detect dark matter or neutrinoless double beta decay. To screen detector surfaces for this radioactive contamination, a low-radiation, multi-wire proportional chamber (the BetaCage) is under construction. Removal of Pb-210 implanted on its 25-micron stainless steel wires without causing significant variation in the diameter of the wires is critical to the BetaCage's ultimate sensitivity. An apparatus to perform electropolishing trials to remove roughly a micron of material has been assembled. These trials have shown promising results. Stainless steel square samples implanted with Pb-210 have shown counts with a reduction factor greater than 10 after electropolishing according to gamma assay. Furthermore, alpha counting has produced similar results, with a reduction factor greater than 100. Lastly, the diameters of wires after electropolishing have remained sufficiently uniform, with reduction in thickness consistent with expectations.

  17. The Unruh effect for eccentric uniformly rotating observers

    NASA Astrophysics Data System (ADS)

    Ramezani-Aval, H.

    It is common to use Galilean rotational transformation (GRT) to investigate the Unruh effect for uniformly rotating observers. However, the rotating observer in this subject is an eccentric observer while GRT is only valid for centrally rotating observers. Thus, the reliability of the results of applying GRT to the study of the Unruh effect might be considered as questionable. In this work, the rotational analog of the Unruh effect is investigated by employing two relativistic rotational transformations corresponding to the eccentric rotating observer, and it is shown that in both cases, the detector response function is nonzero. It is also shown that although consecutive Lorentz transformations cannot give a frame within which the canonical construction can be carried out, the expectation value of particle number operator in canonical approach will be zero if we use modified Franklin transformation. These conclusions reinforce the claim that correspondence between vacuum states defined via canonical field theory and a detector is broken for rotating observers. Some previous conclusions are commented on and some controversies are also discussed.

  18. Self powered neutron detectors as in-core detectors for Sodium-cooled Fast Reactors

    NASA Astrophysics Data System (ADS)

    Verma, V.; Barbot, L.; Filliatre, P.; Hellesen, C.; Jammes, C.; Svärd, S. Jacobsson

    2017-07-01

    Neutron flux monitoring system forms an integral part of the design of a Generation IV sodium cooled fast reactor. Diverse possibilities of detector system installation must be studied for various locations in the reactor vessel in order to detect any perturbations in the core. Results from a previous paper indicated that it is possible to detect changes in neutron source distribution initiated by an inadvertent withdrawal of outer control rod with in-vessel fission chambers located azimuthally around the core. It is, however, not possible to follow inner control rod withdrawal and precisely know the location of the perturbation in the core. Hence the use of complimentary in-core detectors coupled with the peripheral fission chambers is proposed to enable robust core monitoring across the radial direction. In this paper, we assess the feasibility of using self-powered neutron detectors (SPNDs) as in-core detectors in fast reactors for detecting local changes in the power distribution when the reactor is operated at nominal power. We study the neutron and gamma contributions to the total output current of the detector modelled with Platinum as the emitter material. It is shown that this SPND placed in an SFR-like environment would give a sufficiently measurable prompt neutron induced current of the order of 600 nA/m. The corresponding induced current in the connecting cable is two orders of magnitude lower and can be neglected. This means that the SPND can follow in-core power fluctuations. This validates the operability of an SPND in an SFR-like environment.

  19. ZnO:Zn/6LiF scintillator-A low afterglow alternative to ZnS:Ag/6LiF for thermal neutron detection

    NASA Astrophysics Data System (ADS)

    Sykora, G. Jeff; Schooneveld, Erik M.; Rhodes, Nigel J.

    2018-03-01

    Current ZnS:Ag/6LiF based scintillation detectors are often count rate limited by the long lifetime afterglow in the scintillator. Despite this drawback, new instruments at neutron scattering facilities, like ISIS in the UK, would still like to use ZnS:Ag/6LiF detectors due to their low gamma sensitivity, high light output, simplicity of detector design and relatively inexpensive production. One particular advantage of ZnS:Ag/6LiF detectors is their ability to provide strong pulse shape discrimination between neutrons and gammas. Despite the advantages of these detectors, it is becoming clear that new and upgraded instruments will be limited by the count rate capability of ZnS:Ag/6LiF, so an alternative scintillator technology with equivalent simplicity is being sought. ZnO:Zn/6LiF is investigated here as a low afterglow alternative to ZnS:Ag/6LiF. Basic scintillation properties of ZnO:Zn are studied and are discussed. Pulse shape discrimination between neutrons and gammas is explored and taken advantage of through simple single photon counting methods. A further step toward a realistic detector for neutron scattering is also taken by fiber coupling the ZnO:Zn/6LiF to a PMT. In an initial study of this fiber coupled configuration, 60Co gamma sensitivity of ∼ 7 × 10-6 is shown and improvements in count rate capability of at least a factor of 6 over ZnS:Ag/6LiF based neutron detectors are demonstrated.

  20. Multiband Gravitational-Wave Astronomy: Parameter Estimation and Tests of General Relativity with Space- and Ground-Based Detectors.

    PubMed

    Vitale, Salvatore

    2016-07-29

    With the discovery of the binary-black-hole (BBH) coalescence GW150914 the era of gravitational-wave (GW) astronomy has started. It has recently been shown that BBH with masses comparable to or higher than GW150914 would be visible in the Evolved Laser Interferometer Space Antenna (eLISA) band a few years before they finally merge in the band of ground-based detectors. This would allow for premerger electromagnetic alerts, dramatically increasing the chances of a joint detection, if BBHs are indeed luminous in the electromagnetic band. In this Letter we explore a quite different aspect of multiband GW astronomy, and verify if, and to what extent, measurement of masses and sky position with eLISA could improve parameter estimation and tests of general relativity with ground-based detectors. We generate a catalog of 200 BBHs and find that having prior information from eLISA can reduce the uncertainty in the measurement of source distance and primary black hole spin by up to factor of 2 in ground-based GW detectors. The component masses estimate from eLISA will not be refined by the ground based detectors, whereas joint analysis will yield precise characterization of the newly formed black hole and improve consistency tests of general relativity.

  1. Effect of chlorination on the TlBr band edges for improved room temperature radiation detectors: Effect of chlorination on the TlBr band edges for radiation detectors

    DOE PAGES

    Varley, J. B.; Conway, A. M.; Voss, L. F.; ...

    2015-02-09

    Thallium bromide (TlBr) crystals subjected to hydrochloric acid (HCl) chemical treatments have been shown to advantageously affect device performance and longevity in TlBr-based room temperature radiation detectors, yet the exact mechanisms of the improvements remain poorly understood. Here in this paper, we investigate the influence of several HCl chemical treatments on device-grade TlBr and describe the changes in the composition and electronic structure of the surface. Composition analysis and depth profiles obtained from secondary ion mass spectrometry (SIMS) identify the extent to which each HCl etch condition affects the detector surface region and forms of a graded TlBr/TlBr 1-xCL xmore » surface heterojunction. Using a combination of X-ray photoemission spectroscopy (XPS) and hybrid density functional calculations, we are able to determine the valence band offsets, band gaps, and conduction band offsets as a function of Cl content over the entire composition range of TIBr 1-xC1 X. This study establishes a strong correlation between device process conditions, surface chemistry, and electronic structure with the goal of further optimizing the long-term stability and radiation response of TlBr-based detectors.« less

  2. Determination of calibration parameters of a VRX CT system using an “Amoeba” algorithm

    PubMed Central

    Jordan, Lawrence M.; DiBianca, Frank A.; Melnyk, Roman; Choudhary, Apoorva; Shukla, Hemant; Laughter, Joseph; Gaber, M. Waleed

    2008-01-01

    Efforts to improve the spatial resolution of CT scanners have focused mainly on reducing the source and detector element sizes, ignoring losses from the size of the secondary-ionization charge “clouds” created by the detected x-ray photons, i.e., the “physics limit.” This paper focuses on implementing a technique called “projective compression.” which allows further reduction in effective cell size while overcoming the physics limit as well. Projective compression signifies detector geometries in which the apparent cell size is smaller than the physical cell size, allowing large resolution boosts. A realization of this technique has been developed with a dual-arm “variable-resolution x-ray” (VRX) detector. Accurate values of the geometrical parameters are needed to convert VRX outputs to formats ready for optimal image reconstruction by standard CT techniques. The required calibrating data are obtained by scanning a rotating pin and fitting a theoretical parametric curve (using a multi-parameter minimization algorithm) to the resulting pin sinogram. Excellent fits are obtained for both detector-arm sections with an average (maximum) fit deviation of ~0.05 (0.1) detector cell width. Fit convergence and sensitivity to starting conditions are considered. Pre- and post-optimization reconstructions of the alignment pin and a biological subject reconstruction after calibration are shown. PMID:19430581

  3. Determination of calibration parameters of a VRX CT system using an "Amoeba" algorithm.

    PubMed

    Jordan, Lawrence M; Dibianca, Frank A; Melnyk, Roman; Choudhary, Apoorva; Shukla, Hemant; Laughter, Joseph; Gaber, M Waleed

    2004-01-01

    Efforts to improve the spatial resolution of CT scanners have focused mainly on reducing the source and detector element sizes, ignoring losses from the size of the secondary-ionization charge "clouds" created by the detected x-ray photons, i.e., the "physics limit." This paper focuses on implementing a technique called "projective compression." which allows further reduction in effective cell size while overcoming the physics limit as well. Projective compression signifies detector geometries in which the apparent cell size is smaller than the physical cell size, allowing large resolution boosts. A realization of this technique has been developed with a dual-arm "variable-resolution x-ray" (VRX) detector. Accurate values of the geometrical parameters are needed to convert VRX outputs to formats ready for optimal image reconstruction by standard CT techniques. The required calibrating data are obtained by scanning a rotating pin and fitting a theoretical parametric curve (using a multi-parameter minimization algorithm) to the resulting pin sinogram. Excellent fits are obtained for both detector-arm sections with an average (maximum) fit deviation of ~0.05 (0.1) detector cell width. Fit convergence and sensitivity to starting conditions are considered. Pre- and post-optimization reconstructions of the alignment pin and a biological subject reconstruction after calibration are shown.

  4. MEXnICA, Mexican group in the MPD-NICA experiment at JINR

    NASA Astrophysics Data System (ADS)

    Rodríguez Cahuantzi, M.; MEXnICA Group

    2017-10-01

    The Nuclotron Ion Collider fAcility (NICA) accelerator complex is currently under construction at the Joint Institute for Nuclear Research (JINR) laboratory located in the city of Dubna in the Russian Federation. The main goal of NICA is to collide heavy ion nuclei to study the properties of the phase diagram of strongly interacting matter at high baryon density. In this accelerator complex, two big particle detectors are planned to be installed: Spin Physics Detector (SPD) and Multi-Purpose Detector (MPD). At the design luminosity, the event rate in the MPD interaction region is about 6 kHz; the total charged particle multiplicity would exceeds 1000 in the most central Au+Au collisions at \\sqrt{{sNN}} = 11 {{GeV}}. Since the middle of 2016 a group of researchers and students from Mexican institutions was formed (MEXnICA). The main goal of the MEXnICA group is to collaborate in the experimental efforts of MPD-NICA proposing a BEam-BEam counter detector which we called BEBE. In this written general aspects of MPD-NICA detector and BEBE are discussed. This material was shown in a contributed talk given at the XXXI Annual Meeting of the Mexican Division of Particles and Fields held in the Physics Department of CINVESTAV located in Mexico City during the last week of May 2017.

  5. First full dynamic range calibration of the JUNGFRAU photon detector

    NASA Astrophysics Data System (ADS)

    Redford, S.; Andrä, M.; Barten, R.; Bergamaschi, A.; Brückner, M.; Dinapoli, R.; Fröjdh, E.; Greiffenberg, D.; Lopez-Cuenca, C.; Mezza, D.; Mozzanica, A.; Ramilli, M.; Ruat, M.; Ruder, C.; Schmitt, B.; Shi, X.; Thattil, D.; Tinti, G.; Vetter, S.; Zhang, J.

    2018-01-01

    The JUNGFRAU detector is a charge integrating hybrid silicon pixel detector developed at the Paul Scherrer Institut for photon science applications, in particular for the upcoming free electron laser SwissFEL. With a high dynamic range, analogue readout, low noise and three automatically switching gains, JUNGFRAU promises excellent performance not only at XFELs but also at synchrotrons in areas such as protein crystallography, ptychography, pump-probe and time resolved measurements. To achieve its full potential, the detector must be calibrated on a pixel-by-pixel basis. This contribution presents the current status of the JUNGFRAU calibration project, in which a variety of input charge sources are used to parametrise the energy response of the detector across four orders of magnitude of dynamic range. Building on preliminary studies, the first full calibration procedure of a JUNGFRAU 0.5 Mpixel module is described. The calibration is validated using alternative sources of charge deposition, including laboratory experiments and measurements at ESRF and LCLS. The findings from these measurements are presented. Calibrated modules have already been used in proof-of-principle style protein crystallography experiments at the SLS. A first look at selected results is shown. Aspects such as the conversion of charge to number of photons, treatment of multi-size pixels and the origin of non-linear response are also discussed.

  6. Optimising in situ gamma measurements to identify the presence of radioactive particles in land areas.

    PubMed

    Rostron, Peter D; Heathcote, John A; Ramsey, Michael H

    2014-12-01

    High-coverage in situ surveys with gamma detectors are the best means of identifying small hotspots of activity, such as radioactive particles, in land areas. Scanning surveys can produce rapid results, but the probabilities of obtaining false positive or false negative errors are often unknown, and they may not satisfy other criteria such as estimation of mass activity concentrations. An alternative is to use portable gamma-detectors that are set up at a series of locations in a systematic sampling pattern, where any positive measurements are subsequently followed up in order to determine the exact location, extent and nature of the target source. The preliminary survey is typically designed using settings of detector height, measurement spacing and counting time that are based on convenience, rather than using settings that have been calculated to meet requirements. This paper introduces the basis of a repeatable method of setting these parameters at the outset of a survey, for pre-defined probabilities of false positive and false negative errors in locating spatially small radioactive particles in land areas. It is shown that an un-collimated detector is more effective than a collimated detector that might typically be used in the field. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Measurements of charge distributions of the fragments in the low energy fission reaction

    NASA Astrophysics Data System (ADS)

    Wang, Taofeng; Han, Hongyin; Meng, Qinghua; Wang, Liming; Zhu, Liping; Xia, Haihong

    2013-01-01

    The measurement for charge distributions of fragments in spontaneous fission 252Cf has been performed by using a unique style of detector setup consisting of a typical grid ionization chamber and a ΔΕ-Ε particle telescope, in which a thin grid ionization chamber served as the ΔΕ-section and the E-section was an Au-Si surface barrier detector. The typical physical quantities of fragments, such as mass number and kinetic energies as well as the deposition in the gas ΔΕ detector and E detector were derived from the coincident measurement data. The charge distributions of the light fragments for the fixed mass number A2* and total kinetic energy (TKE) were obtained by the least-squares fits for the response functions of the ΔΕ detector with multi-Gaussian functions representing the different elements. The results of the charge distributions for some typical fragments are shown in this article which indicates that this detection setup has the charge distribution capability of Ζ:ΔΖ>40:1. The experimental method developed in this work for determining the charge distributions of fragments is expected to be employed in the neutron induced fissions of 232Th and 238U or other low energy fission reactions.

  8. Development of Metallic Magnetic Calorimeters for High Precision Measurements of Calorimetric Re-187 and Ho-163 Spectra

    NASA Technical Reports Server (NTRS)

    Ranitzsch, P. C.-O.; Porst, J.-P.; Kempf, S.; Pies, C.; Schafer, S.; Hengstler, D.; Fleischmann, A.; Enss, C.; Gastaldo, L.

    2012-01-01

    The measurement of calorimetric spectra following atomic weak decays, beta (b) and electron capture (EC), of nuclides having a very low Q-value, can provide an impressively high sensitivity to a non-vanishing neutrino mass. The achievable sensitivity in this kind of experiments is directly connected to the performance of the used detectors. In particular an energy resolution of a few eV and a pulse formation time well below 1 microsecond are required. Low temperature Metallic Magnetic Calorimeters (MMCs) for soft X-rays have already shown an energy resolution of 2.0 eV FWHM and a pulse rise-time of about 90 ns for fully micro-fabricated detectors. We present the use of MMCs for high precision measurements of calorimetric spectra following the beta-decay of Re-187 and the EC of Ho-163. We show results obtained with detectors optimized for Re-187 and for Ho-163 experiments respectively. While the detectors equipped with superconducting Re absorbers have not yet reached the aimed performance, a first detector prototype with a Au absorber having implanted Ho-163 ions already shows excellent results. An energy resolution of 12 eV FWHM and a rise time of 90 ns were measured.

  9. Toroidal magnetized iron neutrino detector for a neutrino factory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bross, A.; Wands, R.; Bayes, R.

    2013-08-01

    A neutrino factory has unparalleled physics reach for the discovery and measurement of CP violation in the neutrino sector. A far detector for a neutrino factory must have good charge identification with excellent background rejection and a large mass. An elegant solution is to construct a magnetized iron neutrino detector (MIND) along the lines of MINOS, where iron plates provide a toroidal magnetic field and scintillator planes provide 3D space points. In this report, the current status of a simulation of a toroidal MIND for a neutrino factory is discussed in light of the recent measurements of largemore » $$\\theta_{13}$$. The response and performance using the 10 GeV neutrino factory configuration are presented. It is shown that this setup has equivalent $$\\delta_{CP}$$ reach to a MIND with a dipole field and is sensitive to the discovery of CP violation over 85% of the values of $$\\delta_{CP}$$.« less

  10. Spin Seebeck devices using local on-chip heating

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, Stephen M.; Fradin, Frank Y.; Hoffman, Jason

    2015-05-07

    A micro-patterned spin Seebeck device is fabricated using an on-chip heater. Current is driven through a Au heater layer electrically isolated from a bilayer consisting of Fe3O4 (insulating ferrimagnet) and a spin detector layer. It is shown that through this method it is possible to measure the longitudinal spin Seebeck effect (SSE) for small area magnetic devices, equivalent to traditional macroscopic SSE experiments. Using a lock-in detection technique, it is possible to more sensitively characterize both the SSE and the anomalous Nernst effect (ANE), as well as the inverse spin Hall effect in various spin detector materials. By using themore » spin detector layer as a thermometer, we can obtain a value for the temperature gradient across the device. These results are well matched to values obtained through electromagnetic/thermal modeling of the device structure and with large area spin Seebeck measurements.« less

  11. Spin Seebeck devices using local on-chip heating

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, Stephen M., E-mail: swu@anl.gov; Fradin, Frank Y.; Hoffman, Jason

    2015-05-07

    A micro-patterned spin Seebeck device is fabricated using an on-chip heater. Current is driven through a Au heater layer electrically isolated from a bilayer consisting of Fe{sub 3}O{sub 4} (insulating ferrimagnet) and a spin detector layer. It is shown that through this method it is possible to measure the longitudinal spin Seebeck effect (SSE) for small area magnetic devices, equivalent to traditional macroscopic SSE experiments. Using a lock-in detection technique, it is possible to more sensitively characterize both the SSE and the anomalous Nernst effect (ANE), as well as the inverse spin Hall effect in various spin detector materials. Bymore » using the spin detector layer as a thermometer, we can obtain a value for the temperature gradient across the device. These results are well matched to values obtained through electromagnetic/thermal modeling of the device structure and with large area spin Seebeck measurements.« less

  12. Temperature dependence of the response of ultra fast silicon detectors

    NASA Astrophysics Data System (ADS)

    Mulargia, R.; Arcidiacono, R.; Bellora, A.; Boscardin, M.; Cartiglia, N.; Cenna, F.; Cirio, R.; Dalla Betta, G. F.; Durando, S.; Fadavi, A.; Ferrero, M.; Galloway, Z.; Gruey, B.; Freeman, P.; Kramberger, G.; Mandic, I.; Monaco, V.; Obertino, M.; Pancheri, L.; Paternoster, G.; Ravera, F.; Sacchi, R.; Sadrozinski, H. F. W.; Seiden, A.; Sola, V.; Spencer, N.; Staiano, A.; Wilder, M.; Woods, N.; Zatserklyaniy, A.

    2016-12-01

    The Ultra Fast Silicon Detectors (UFSD) are a novel concept of silicon detectors based on the Low Gain Avalanche Diode (LGAD) technology, which are able to obtain time resolution of the order of few tens of picoseconds. First prototypes with different geometries (pads/pixels/strips), thickness (300 and 50 μm) and gain (between 5 and 20) have been recently designed and manufactured by CNM (Centro Nacional de Microelectrónica, Barcelona) and FBK (Fondazione Bruno Kessler, Trento). Several measurements on these devices have been performed in laboratory and in beam test and a dependence of the gain on the temperature has been observed. Some of the first measurements will be shown (leakage current, breakdown voltage, gain and time resolution on the 300 μm from FBK and gain on the 50 μm-thick sensor from CNM) and a comparison with the theoretically predicted trend will be discussed.

  13. Microwave SQUID Multiplexer for the Readout of Metallic Magnetic Calorimeters

    NASA Astrophysics Data System (ADS)

    Kempf, S.; Gastaldo, L.; Fleischmann, A.; Enss, C.

    2014-06-01

    We have realized a frequency-domain multiplexing technique for the readout of large metallic magnetic calorimeter detector arrays. It is based on non-hysteretic single-junction SQUIDs and allows for a simultaneous readout of hundreds or thousands of detectors by using a single cryogenic high electron mobility transistor amplifier and two coaxial cables that are routed from room-temperature to the detector array. We discuss the working principle of the multiplexer and present details about our prototype multiplexer design. We show that fabricated devices are fully operational and that characteristic SQUID parameters such as the input sensitivity of the SQUID or the resonance frequency of the readout circuit can be predicted with confidence. Our best device so far has shown a magnetic flux white noise level of 1.4 m which can in future be reduced by an optimization of the fabrication processes as well as an improved microwave readout system.

  14. Temperature-sensitive junction transformations for mid-wavelength HgCdTe photovoltaic infrared detector arrays by laser beam induced current microscope

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Qiu, Weicheng; National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083; Hu, Weida, E-mail: wdhu@mail.sitp.ac.cn

    2014-11-10

    In this paper, we report on the disappearance of the photosensitive area extension effect and the unusual temperature dependence of junction transformation for mid-wavelength, n-on-p HgCdTe photovoltaic infrared detector arrays. The n-type region is formed by B{sup +} ion implantation on Hg-vacancy-doped p-type HgCdTe. Junction transformations under different temperatures are visually captured by a laser beam induced current microscope. A physical model of temperature dependence on junction transformation is proposed and demonstrated by using numerical simulations. It is shown that Hg-interstitial diffusion and temperature activated defects jointly lead to the p-n junction transformation dependence on temperature, and the weaker mixedmore » conduction compared with long-wavelength HgCdTe photodiode contributes to the disappearance of the photosensitive area extension effect in mid-wavelength HgCdTe infrared detector arrays.« less

  15. Measurement of the noise power spectrum in digital x-ray detectors

    NASA Astrophysics Data System (ADS)

    Aufrichtig, Richard; Su, Yu; Cheng, Yu; Granfors, Paul R.

    2001-06-01

    The noise power spectrum, NPS, is a key imaging property of a detector and one of the principle quantities needed to compute the detective quantum efficiency. NPS is measured by computing the Fourier transform of flat field images. Different measurement methods are investigated and evaluated with images obtained from an amorphous silicon flat panel x-ray imaging detector. First, the influence of fixed pattern structures is minimized by appropriate background corrections. For a given data set the effect of using different types of windowing functions is studied. Also different window sizes and amounts of overlap between windows are evaluated and compared to theoretical predictions. Results indicate that measurement error is minimized when applying overlapping Hanning windows on the raw data. Finally it is shown that radial averaging is a useful method of reducing the two-dimensional noise power spectrum to one dimension.

  16. Calculation of background effects on the VESUVIO eV neutron spectrometer

    NASA Astrophysics Data System (ADS)

    Mayers, J.

    2011-01-01

    The VESUVIO spectrometer at the ISIS pulsed neutron source measures the momentum distribution n(p) of atoms by 'neutron Compton scattering' (NCS). Measurements of n(p) provide a unique window into the quantum behaviour of atomic nuclei in condensed matter systems. The VESUVIO 6Li-doped neutron detectors at forward scattering angles were replaced in February 2008 by yttrium aluminium perovskite (YAP)-doped γ-ray detectors. This paper compares the performance of the two detection systems. It is shown that the YAP detectors provide a much superior resolution and general performance, but suffer from a sample-dependent gamma background. This report details how this background can be calculated and data corrected. Calculation is compared with data for two different instrument geometries. Corrected and uncorrected data are also compared for the current instrument geometry. Some indications of how the gamma background can be reduced are also given.

  17. Charged-particle distributions in pp interactions at √s=8TeV measured with the ATLAS detector

    DOE PAGES

    Aad, G.; Abbott, B.; Abdallah, J.; ...

    2016-07-15

    This study presents measurements of distributions of charged particles which are produced in proton–proton collisions at a centre-of-mass energy of √s=8TeV and recorded by the ATLAS detector at the LHC. A special dataset recorded in 2012 with a small number of interactions per beam crossing (below 0.004) and corresponding to an integrated luminosity of 160 μb -1 was used. A minimum-bias trigger was utilised to select a data sample of more than 9 million collision events. The multiplicity, pseudorapidity, and transverse momentum distributions of charged particles are shown in different regions of kinematics and charged-particle multiplicity, including measurements of finalmore » states at high multiplicity. Finally, the results are corrected for detector effects and are compared to the predictions of various Monte Carlo event generator models which simulate the full hadronic final state.« less

  18. Performance of a multistep fluorescence-gated proportional counter for hard X-ray astronomy

    NASA Technical Reports Server (NTRS)

    Dietz, K. L.; Ramsey, B. D.; Weisskopf, M. C.

    1992-01-01

    Results from the first flight of our proportional counter in an imaging telescope led us to rebuild the detector. We have used a Penning gas mixture (xenon + 1 percent isobutylene) and introduced a preamplification region to improve the energy resolution. We have rebuilt the pressure vessel making novel use of molybdenum as the housing material in order to reduce the residual instrument background, particularly in the fluorescence-gated mode for which the detector design has been optimized. We have also increased the sensitive gas depth from 9 to 14 cm to further increase the sensitivity to both fluorescent pairs and conventional singles. Our calibrations have shown that the overall energy resolution of the detector has been enhanced by a factor of 2, and we predict that the sensitivity at float will increase by a factor of 3 in the 50-70 keV energy band.

  19. Quantum key distribution without detector vulnerabilities using optically seeded lasers

    NASA Astrophysics Data System (ADS)

    Comandar, L. C.; Lucamarini, M.; Fröhlich, B.; Dynes, J. F.; Sharpe, A. W.; Tam, S. W.-B.; Yuan, Z. L.; Penty, R. V.; Shields, A. J.

    2016-05-01

    Security in quantum cryptography is continuously challenged by inventive attacks targeting the real components of a cryptographic set-up, and duly restored by new countermeasures to foil them. Owing to their high sensitivity and complex design, detectors are the most frequently attacked components. It was recently shown that two-photon interference from independent light sources can be used to remove any vulnerability from detectors. This new form of detection-safe quantum key distribution (QKD), termed measurement-device-independent (MDI), has been experimentally demonstrated but with modest key rates. Here, we introduce a new pulsed laser seeding technique to obtain high-visibility interference from gain-switched lasers and thereby perform MDI-QKD with unprecedented key rates in excess of 1 megabit per second in the finite-size regime. This represents a two to six orders of magnitude improvement over existing implementations and supports the new scheme as a practical resource for secure quantum communications.

  20. Capabilities of CdTe-Based Detectors With {mathrm {MoO}}_{x} Contacts for Detection of X- and gamma -Radiation

    NASA Astrophysics Data System (ADS)

    Maslyanchuk, O. L.; Solovan, M. M.; Brus, V. V.; Kulchynsky, V. V.; Maryanchuk, P. D.; Fodchuk, I. M.; Gnatyuk, V. A.; Aoki, T.; Potiriadis, C.; Kaissas, Y.

    2017-05-01

    The charge transport mechanism and spectrometric properties of the X-ray and γ-ray detectors, fabricated by the deposition of molybdenum oxide thin films onto semi-insulating p-CdTe crystals were studied. The current transport processes in the Mo-MoOx/p-CdTe/MoOx-Mo structure are well described in the scope of the carrier's generation in the space-charge region and the space-charge-limited current models. The lifetime of charge carriers, the energy of hole traps, and the density of discrete trapping centers were determined from the comparison of the experimental data and calculations. Spectrometric properties of Mo-MoOx/p-CdTe/MoOx-Mo structures were also investigated. It is shown that the investigated heterojunctions have demonstrated promising characteristics for practical application in X-ray and γ-ray detector fabrication.

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