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Sample records for single photomultiplier tube

  1. photomultiplier tubes

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  2. photomultiplier tube

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  3. photomultiplier tube

    CERN Multimedia

    A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  4. photomultiplier tube

    CERN Multimedia

    Philips. 150AVP. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  5. Model independent approach to the single photoelectron calibration of photomultiplier tubes

    Energy Technology Data Exchange (ETDEWEB)

    Saldanha, R.; Grandi, L.; Guardincerri, Y.; Wester, T.

    2017-08-01

    The accurate calibration of photomultiplier tubes is critical in a wide variety of applications in which it is necessary to know the absolute number of detected photons or precisely determine the resolution of the signal. Conventional calibration methods rely on fitting the photomultiplier response to a low intensity light source with analytical approximations to the single photoelectron distribution, often leading to biased estimates due to the inability to accurately model the full distribution, especially at low charge values. In this paper we present a simple statistical method to extract the relevant single photoelectron calibration parameters without making any assumptions about the underlying single photoelectron distribution. We illustrate the use of this method through the calibration of a Hamamatsu R11410 photomultiplier tube and study the accuracy and precision of the method using Monte Carlo simulations. The method is found to have significantly reduced bias compared to conventional methods and works under a wide range of light intensities, making it suitable for simultaneously calibrating large arrays of photomultiplier tubes.

  6. Scintillation counter: photomultiplier tube alignment

    International Nuclear Information System (INIS)

    Olson, R.E.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into the sample receiving zone. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (auth)

  7. An anti-Cherenkov photomultiplier tube

    International Nuclear Information System (INIS)

    Selove, W.; Cormell, L.R.; Dris, M.; Kononenko, W.; Robinson, B.; Yost, B.T.

    1982-01-01

    We have designed a special photomultiplier tube (PMT), with very much reduced sensitivity to Cherenkov light produced in the end window. These PMTs have been produced for us by EMI, and have been used in a modular calorimeter array. The design eliminates a 'hot-spot' problem which was of intolerable magnitude in our application. (orig.)

  8. Performance of the hybrid photomultiplier tube (HPMT)

    Energy Technology Data Exchange (ETDEWEB)

    Schomaker, R.J. [B.V. Delft Electronische Producten, Roden (Netherlands)

    1995-12-31

    The HPMT, which may be an alternative for PhotoMultiplier Tubes (PMT`s) in many applications, is a vacuum tube in which the latest technologies of photocathodes and photodiodes are combined. Photo-electrons are accelerated and bombarding a reversely biased PIN diode, where they create many electron-hole-pairs. The resulting charge pulse can be amplified and further processed. The HPMT shows many superior characteristics compared to regular PMT`s, because it does not suffer the statistical fluctuations common for electron multiplication processes. An energy resolution of up to 14 photo-electrons will be presented, together with striking figures for dynamic range and timing behavior.

  9. Improving the performance of photomultiplier tubes

    Energy Technology Data Exchange (ETDEWEB)

    Harmer, S W [Department of Engineering and Technology, Manchester Metropolitan University, Manchester M1 5GD (United Kingdom); Townsend, P D, E-mail: pdtownsend@googlemail.co [Science and Technology, University of Sussex, Brighton BN1 9QH (United Kingdom)

    2010-10-20

    Photomultipliers are ubiquitous detectors of low level light signals, but their performance is limited by the complexity of photocathode technology. Two contributory problems are that light is lost both by surface reflection and by transmission through the photocathode layer. Knowledge of the dielectric constants has allowed predictive modelling of the reflectivity and absorption of the light as a function of angle of incidence, cathode thickness and polarization. The predictions have stimulated designs of extremely simple and very low cost retrofit approaches to improve the overall effectiveness of photomultipliers. One simple design presented here exploits signal that is normally lost by the surface reflection. A simple external conical torch reflector is clipped over the photomultiplier end face. The reflector raised the efficiency of an S20 multialkali photocathode by between 20% and 10% across the blue to red spectral range. An alternative semi-cylindrical glass coupler has improved the absorption efficiency by allowing the input signal to arrive at 60{sup 0} incidence to the photocathode surface, rather than normal incidence as in the standard head-on geometry. Enhancements are from 30% to 500% across the spectral range. The greater gains are at long wavelengths, and so are particularly valuable as this is the region of lowest quantum efficiency. The latter high-incidence angle approach, when applied to a low-efficiency C grade tube, has raised the performance to greater than the best of the A grade tubes, as used in the normal head-on operation. Both methods are equally applicable to other cathode compositions.

  10. Cathode uniformity of new square photomultiplier tubes

    International Nuclear Information System (INIS)

    Brenner, R.; Chou, H.P.; Strauss, M.G.; Winiecki, A.L.

    1981-01-01

    Square photomultiplier tubes (PMTs) should have better light collection than round PMTs when used in square or rectangular Anger-type #betta#-ray or neutron position detectors. Photocathode response uniformity of new RCA square PMTs type S83003E (51.5 x 51.5 mm 2 ) was measured and compared with conventional round PMTs. The PMTs were scanned with a small scintillation source while the anode signal amplitudes were processed in a computer-based multichannel analyzer. The analyzer was programmed in a mode which virtually eliminates effects due to statistical fluctuations in source rate and output amplitude. Pulse heights as a function of source position on the PMT face are shown for typical tubes. The response uniformity of 64 square PMTs and 21 round ones was evaluated. It is shown that the center region of the square PMTs is as uniform as that of the round ones and that the response in the corners is comparable to that in the center. Thus square PMTs appear to have an advantage for use in square or rectangular position detectors

  11. A Cockcroft-Walton base for R329 photomultiplier tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kato, S.; Shiino, K.; Terada, S.; Kobayashi, N.; Takahashi, K.

    1995-06-01

    A Cockcroft-Walton photomultiplier tube base was constructed for the SDC muon scintillation counters which use a R329 photomultiplier tube (Hamamatsu). We present test results of linearity, load characteristics and power dissipation. The base was verified to be reliable, robust against magnetic field and easily computer controlled. The voltage distribution ratio of the cathode was adopted to be a value of 4:1:1:1:1:1:1:1:1:1:1:1:1. (author).

  12. Light Production in the Double Chooz Photomultiplier Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, E.; Cerrada, M.; Crespo, J. I.; Gil-Botella, I.; Jimenez, S.; Lopez, M.; Novella, P.; Palomares, C.; Santorelli, R.; Verdugo, A.

    2012-09-13

    In this document we present a study of the phenomenon of light emission (called glowing) in the bases of the Hamamatsu R7081MOD-ASSY photomultiplier tubes (PMTs) used in the Double Chooz experiment. The tests have been carried out at the CIEMAT laboratories over a photomultiplier tube of the same model. We have studied the phenomenon making first a characterization of it, and then focusing on the dependence of the rate and the amount of emitted light versus voltage and temperature. In addition, we have looked for the possible existence of an ultraviolet component in the light which would be harmful for the experiment because it could be able to excite the scintillator liquid. Finally, we propose and test a method to reduce the light emission using a cover on the base of the photomultiplier tube.. (Author)

  13. A superconducting supercollider calorimeter photomultiplier tube preamplifier circuit

    International Nuclear Information System (INIS)

    Panescu, D.; Lackey, J.; Robl, P.; Smith, W.H.

    1992-01-01

    This study presents the design of the front end amplifier for a scintillator calorimeter with photomultiplier tube (PMT) readout. The design is based on analytical computations and SPICE simulations, and is checked against tests performed on a prototyped circuit. We were looking to achieve 1) a very low droop within the 4 ns after the integration of the photomultiplier tube (PMT) signal was completed, 2) a very low noise figure for the whole amplifier in a 100 MHz bandwidth, 3) an input impedance optimized for the PMT which is actually used, 4) baseline restoration as quick as possible at the output of the clip amps, 5) no loss of information due to the saturation at intermediary stages (e.g. integrator), and 6) an output driving 100 Ω twisted pair cables, or 50 Ω coaxial cables, in order to transmit the signal to switched capacitor arrays for analog storage. (orig.)

  14. Actively-stabilized photomultiplier tube base for vacuum operation

    International Nuclear Information System (INIS)

    Bryan, M.A; Morris, C.L.; Idzorek, G.C.

    1992-01-01

    An actively stabilized photomultiplier tube (PMT) base design for an Amperex XP-2262B PMT is described. Positive-negative-positive transistors are used as low-impedance current sources to maintain constant voltages on the last three dynodes. This technique results in a highly stable, low-power tube base ideal for use with low-duty-factor beams, such as those found at the Clinton P. Anderson Meson Physics Facility. Furthermore, because of the low power usage of this large design, these bases can be sealed in a heat-conductive, electrically insulating material and used in a vacuum

  15. Precise analysis of the metal package photomultiplier single photoelectron spectra

    International Nuclear Information System (INIS)

    Chirikov-Zorin, I.E.; Fedorko, I.; Sykora, I.; Tokar, S.; Menzione, A.

    2000-01-01

    A deconvolution method based on a sophisticated photomultiplier response function was used to analyse the compact metal package photomultiplier spectra taken in single photoelectron mode. The spectra taken by Hamamtsu R5600 and R5900 photomultipliers have been analysed. The detailed analysis shows that the method appropriately describes the process of charge multiplication in these photomultipliers in a wide range of working regimes and the deconvoluted parameters are established with about 1% accuracy. The method can be used for a detailed analysis of photomultiplier noise and for calibration purposes

  16. An overview of current developments in position-sensitive hybrid photon detectors and photo-multiplier tubes

    CERN Document Server

    Gys, Thierry

    1999-01-01

    Current developments in position-sensitive hybrid photon detectors and photo-multiplier tubes have stimulated increased interest from a variety of fields such as astronomy, biomedical imaging and high- energy physics. These devices are sensitive to single photons over a photon energy spectrum defined by the transmission of the optical entrance window and the photo-cathode type. Their spatial resolution ranges from a few millimeters for pad hybrid photon detectors and multi-anode photo-multiplier tubes down to a few tens of microns for pixel hybrid photon detectors and electron-bombarded charge-coupled devices. Basic technological and design aspects are assessed in this paper. (21 refs).

  17. Characterization of a multi-anode photo-multiplier tube for array detectors

    CERN Document Server

    Xu Li Bo; Li Yu Lan; Wang Shao Feng

    2002-01-01

    Two types of Haematomas R5900 series photomultiplier tubes (PMTs) have been evaluated for reading out arrays of small scintillator elements. Both PMTs have metal-channel dynode structures and compact dimensions. H6568 and H6568-10 have the same dimensions of 30 mm x 30 mm x 45 mm and different voltage distribution ratio. The authors report measurements that include gain, single photoelectron spectrum, linearity of anode output signal, cross-talk and gain variation. The characteristics of the MAPMT make it well suited for detection of light from scintillator array

  18. Upgrading PhotoMultiplier Tube bases for FNAL E1039

    Science.gov (United States)

    Salinas, Roy; SeaQuest Collaboration

    2017-09-01

    Experiment 1039 at Fermilab National Laboratory is designed to study the spin structure within the nucleon. To effectively work towards a better understanding of the ``spin crisis'' concerning the quarks and gluons within the nucleon, E1039 will employ a polarized target and a 120 GeV proton beam. The E906/SeaQuest spectrometer will be reused for E1039 since it was designed to measure Drell-Yan events from interactions with quarks in the nucleon sea. The spectrometer consists of several detectors with multiple planes of scintillating hodoscopes, tracking chambers, and two large dipole magnets. An issue arose in the later stages of Experiment 906 regarding the scintillating PhotoMultiplier Tubes(PMTs) high current bases for the first two hodoscope stations. Heat produced in the PMT bases created damage to components on the primary circuit board resulting in failures after years of running. Multiple solutions focused on thermally connecting the daughter cards to the metal shielding pipe while also providing electrical isolation of the high voltages present. Comparisons of thermally conductive adhesive and epoxy were studied with several heat spreaders. This poster will cover the options considered and the chosen solution to the upgrade to the hodoscope PMT bases. Supported by U.S. D.O.E. Medium Energy Nuclear Physics under Grant DE-FG02-03ER41243.

  19. Characterization of Multianode Photomultiplier Tubes for a Cherenkov Detector

    Science.gov (United States)

    Benninghoff, Morgen; Turisini, Matteo; Kim, Andrey; Benmokhtar, Fatiha; Kubarovsky, Valery; Duquesne University Collaboration; Jefferson Lab Collaboration

    2017-09-01

    In the Fall of 2017, Jefferson Lab's CLAS12 (CEBAF Large Acceptance Spectrometer) detector is expecting the addition of a RICH (ring imaging Cherenkov) detector which will allow enhanced particle identification in the momentum range of 3 to 8 GeV/c. RICH detectors measure the velocity of charged particles through the detection of produced Cherenkov radiation and the reconstruction of the angle of emission. The emitted Cherenkov photons are detected by a triangular-shaped grid of 391 multianode photomultiplier tubes (MAPMTs) made by Hamamatsu. The custom readout electronics consist of MAROC (multianode read out chip) boards controlled by FPGA (Field Programmable Gate Array) boards, and adapters used to connect the MAROC boards and MAPMTs. The focus of this project is the characterization of the MAPMTs with the new front end electronics. To perform these tests, a black box setup with a picosecond diode laser was constructed with low and high voltage supplies. A highly automated procedure was developed to acquire data at different combinations of high voltage values, light intensities and readout electronics settings. Future work involves using the collected data in calibration procedures and analyzing that data to resolve the best location for each MAPMT. SULI, NSF.

  20. Study of large hemispherical photomultiplier tubes for the ANTARES neutrino telescope

    Science.gov (United States)

    Aguilar, J. A.; Albert, A.; Ameli, F.; Amram, P.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardellier-Desages, F. E.; Aslanides, E.; Aubert, J.-J.; Bailey, D.; Basa, S.; Battaglieri, M.; Becherini, Y.; Bellotti, R.; Beltramelli, J.; Bertin, V.; Billault, M.; Blaes, R.; Blanc, F.; de Botton, N.; Boulesteix, J.; Bouwhuis, M. C.; Brooks, C. B.; Bradbury, S. M.; Bruijn, R.; Brunner, J.; Burgio, G. F.; Cafagna, F.; Calzas, A.; Capone, A.; Caponetto, L.; Carmona, E.; Carr, J.; Cartwright, S. L.; Castorina, E.; Cavasinni, V.; Cecchini, S.; Charvis, P.; Circella, M.; Colnard, C.; Compère, C.; Coniglione, R.; Cooper, S.; Coyle, P.; Cuneo, S.; Damy, G.; van Dantzig, R.; Deschamps, A.; de Marzo, C.; Denans, D.; Destelle, J.-J.; de Vita, R.; Dinkelspiler, B.; Distefano, C.; Drogou, J.-F.; Druillole, F.; Engelen, J.; Ernenwein, J.-P.; Falchini, E.; Favard, S.; Feinstein, F.; Ferry, S.; Festy, D.; Flaminio, V.; Fopma, J.; Fuda, J.-L.; Gallone, J.-M.; Giacomelli, G.; Girard, N.; Goret, P.; Graf, K.; Hallewell, G.; Hartmann, B.; Heijboer, A.; Hello, Y.; Hernández-Rey, J. J.; Herrouin, G.; Hößl, J.; Hoffmann, C.; Hubbard, J. R.; Jaquet, M.; de Jong, M.; Jouvenot, F.; Kappes, A.; Karg, T.; Karkar, S.; Karolak, M.; Katz, U.; Keller, P.; Kooijman, P.; Korolkova, E. V.; Kouchner, A.; Kretschmer, W.; Kuch, S.; Kudryavtsev, V. A.; Lafoux, H.; Lagier, P.; Lahmann, R.; Lamare, P.; Languillat, J.-C.; Laschinsky, H.; Laubier, L.; Legou, T.; Le Guen, Y.; Le Provost, H.; Le van Suu, A.; Lo Nigro, L.; Lo Presti, D.; Loucatos, S.; Louis, F.; Lyashuk, V.; Marcelin, M.; Margiotta, A.; Maron, C.; Massol, A.; Masullo, R.; Mazéas, F.; Mazure, A.; McMillan, J. E.; Migneco, E.; Millot, C.; Milovanovic, A.; Montanet, F.; Montaruli, T.; Morel, J.-P.; Morganti, M.; Moscoso, L.; Musumeci, M.; Naumann, C.; Naumann-Godo, M.; Nezri, E.; Niess, V.; Nooren, G. J.; Ogden, P.; Olivetto, C.; Palanque-Delabrouille, N.; Papaleo, R.; Payre, P.; Petta, C.; Piattelli, P.; Pineau, J.-P.; Poinsignon, J.; Popa, V.; Potheau, R.; Pradier, T.; Racca, C.; Raia, G.; Randazzo, N.; Real, D.; van Rens, B. A. P.; Réthoré, F.; Riccobene, G.; Rigaud, V.; Ripani, M.; Roca-Blay, V.; Rolin, J.-F.; Romita, M.; Rose, H. J.; Rostovtsev, A.; Ruppi, M.; Russo, G. V.; Sacquin, Y.; Salesa, F.; Salomon, K.; Saouter, S.; Sapienza, P.; Shanidze, R.; Schuller, J.-P.; Schuster, W.; Sokalski, I.; Spurio, M.; Stolarczyk, T.; Stubert, D.; Taiuti, M.; Thompson, L. F.; Tilav, S.; Valdy, P.; Valente, V.; Vallage, B.; Vernin, P.; Virieux, J.; de Vries, G.; de Witt Huberts, P.; de Wolf, E.; Zaborov, D.; Zaccone, H.; Zakharov, V.; Zornoza, J. D.; Zúñiga, J.

    2005-12-01

    The ANTARES neutrino telescope, to be immersed depth in the Mediterranean Sea, will consist of a three-dimensional matrix of 900 large area photomultiplier tubes housed in pressure-resistant glass spheres. The selection of the optimal photomultiplier was a critical step for the project and required an intensive phase of tests and developments carried out in close collaboration with the main manufacturers worldwide. This paper provides an overview of the tests performed by the collaboration and describes in detail the features of the photomultiplier tube chosen for ANTARES.

  1. Accuracy of single photoelectron time spread measurement of fast photomultipliers

    International Nuclear Information System (INIS)

    Leskovar, B.

    1975-01-01

    The accuracy of time spread measurements of fast photomultipliers was investigated, using single photoelectrons. The effect of the finite light pulse width on the measurement accuracy was determined and discussed. Experimental data were obtained on a special measuring system for light pulse widths ranging from 200 psec to 10 nsec, using fast photomultipliers 8850 and C31024 with optimized operating conditions for minimum transit time spread. A modified exponential function expression and curve-fitting parameters are given, which fit closely the experimentally obtained data over a wide dynamic range of light pulse widths. (U.S.)

  2. The photomultiplier tube testing facility for the Borexino experiment at LNGS

    Energy Technology Data Exchange (ETDEWEB)

    Brigatti, A. [INFN sez. di Milano, Via Celoria, 16, I-20133 Milan (Italy); Ianni, A. [INFN - Laboratori Nazionali del Gran Sasso, S.S. 17bis Km 18-910, I-67010 Assergi, Aquila (Italy); Lombardi, P. [Dipartimento di Fisica Universita and INFN. sez. di Milano, Via Celoria, 16, I-20133 Milan (Italy); Ranucci, G. [Dipartimento di Fisica Universita and INFN. sez. di Milano, Via Celoria, 16, I-20133 Milan (Italy); Smirnov, O.Ju. [Joint Institute for Nuclear Research, Joliot-Curie, 6, 141980 Dubna (Russian Federation)]. E-mail: smirnov@lngs.infn.it

    2005-02-01

    A facility to test the photomultiplier tubes (PMTs) for the solar neutrino detector Borexino was built at the Gran Sasso laboratory. Using the facility 2200 PMTs with optimal characteristics were selected from the 2350 delivered from the manufacturer. The details of the hardware used are presented.

  3. An efficient high-voltage power supply for a photomultiplier tube

    NARCIS (Netherlands)

    Ainutdinov, VM; Vonsovskii, NN; Kompaniets, KG; Kozyr, AI; Mikhailov, YV

    2003-01-01

    An adjustable power supply for a photomultiplier tube operating in the pulsed spectrometric mode with a wide range of linearity is described. The power consumed by the source is 50 mW. The output voltage is varied from 800 to 2000 V. The maximum ripple amplitude is 2.5 mV.

  4. Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

    NARCIS (Netherlands)

    Aprile, E.; et al., [Unknown; Alfonsi, M.; Colijn, A.P.; Decowski, M.P.; Tiseni, A.; Tunnell, C.

    2015-01-01

    The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company

  5. Evaluation of magnetic defocusing for a photomultiplier tube with large area semitransparent photocathode.

    Science.gov (United States)

    Knight, W; Kohanzadeh, Y; Lengyel, G

    1968-06-01

    Reduction of the effective cathode area of photomultiplier tubes is known to yield lower dark currents and an improved signal-to-noise ratio. This can be accomplished either by electrostatic or magnetic defocusing of the electron beam between the cathode and the first dynode. Three magnetic lenses with different field geometries were tried with an EMI 9558B photomultiplier tube, and a noise reduction of more than an order of magnitude was observed. Magnetic defocusing changes the pulse height characteristies of the tube as well and improves the discrimination between signal pulses and dark pulses when using simple pulse height discrimination techniques. If the tube is operated as a photon counter, the light-to-dark count ratio may be improved by nearly two orders of magnitude with the application of a suitable magnetic lens.

  6. Time fluctuations in the response of photomultiplier tubes Dario 56 AVP, XP 1021, XP 1210

    International Nuclear Information System (INIS)

    Breuze, G.; Sawine, P.

    1969-01-01

    The authors have studied experimentally the intrinsic time resolving power of 3 photomultiplier tubes, Dario 56 AVP, XP 1021, XP 1210 at various excitation levels produced by a source of short light pulses. They show, in agreement with present theories, that there exists an optimal resolving power for a certain trigger threshold, and they check the law governing the variations of this resolving power with the average number of photo-electrons emitted by light pulse, up to the limiting case of a single photo-electron. The results obtained show the progress which has been made by the constructor between the 56 AVP and the XP 1210 models: for 100 photo-electrons per pulse, for example, the times of resolution are 260 x 10 -12 s and 75 x 10 -12 s respectively; whereas the rise time for the anode pulses decreases from 2,3 to 1,2 x 10 -9 s. The intermediate tube XP 1021 has also a particularly good performance with respect to the 56 AVP, which it resembles very much both in its price and by its outer aspect. The authors stress finally the difficulties encountered in measuring with accuracy the time characteristics of PM as fast as the XP 1210, and in particular the limitation imposed by the light source. (author) [fr

  7. Dynamic magnetic shield for the CLAS12 central TOF detector photomultiplier tubes

    International Nuclear Information System (INIS)

    The Central Time-of-Flight detector for the Jefferson Laboratory 12-GeV upgrade is being designed with linear-focused photomultiplier tubes that require a robust magnetic shield against the CLAS12 main 5-T solenoid fringe fields of 100 mT (1 kG). Theoretical consideration of a ferromagnetic cylinder in an axial field has demonstrated that its shielding capability decreases with increasing length. This observation has been confirmed with finite element analysis using POISSON model software. Several shields composed of coaxial ferromagnetic cylinders have been studied. All difficulties caused by saturation effects were overcome with a novel dynamical shield, which utilizes a demagnetizing solenoid between the shielding cylinders. Basic dynamical shields for ordinary linear-focused 2-in. photomultiplier tubes were designed and tested both with models and experimental prototypes at different external field and demagnetizing current values. Our shield design reduces the 1 kG external axial field by a factor of 5000.

  8. Multi Anode Photomultiplier Tube Reliability Assessment for the JEM-EUSO Space Mission

    OpenAIRE

    Prieto-Alfonso, H.; del Peral, L.; Casolino, M.; Tsuno, K.; Ebisuzaki, T.; Frías, M. D. Rodríguez; Collaboration, JEM-EUSO

    2015-01-01

    Reliability assessment in concerned with the analysis of devices and systems whose individual components are prone to fail. This reliability analysis documents the process and results of reliability determination of the JEM-EUSO photomultiplier tube component using the methods 217 Plus. Quantum efficiency degradation and radiation hardness assurance. In conclussion, the levels of damage suffered by the PMTs which comprise the focal surface of JEM-EUSO Space Telescope, are acceptable. The resu...

  9. Test of multi-anode photomultiplier tubes for the LHCb scintillator pad detector

    CERN Document Server

    Aguiló, Ernest; Comerma-Montells, A; Garrido, Lluis; Gascon, David; Graciani, Ricardo; Grauges, Eugeni; Vilasis Cardona, Xavier; Xirgu, Xavier; Bohner, Gerard; Bonnefoy, Romeo; Borras, David; Cornat, Remi; Crouau, Michel; Deschamps, Olivier; Jacquet, Philippe; Lecoq, Jacques; Monteil, Stephane; Perret, Pascal; Reinmuth, Guy

    2005-01-01

    The LHCb experiment (The LHCb Technical Proposal, CERN/LHCC 98-4) is designed to study B meson physics in the LHC proton-proton collider at CERN. The Scintillator Pad Detector (SPD) has been designed to complete the calorimeter information performing an e/gamma identification for the experiment level-0 trigger system. The detection technology consists in transmitting scintillation light by means of both Wavelength Shifting and clear fibers to fast multi- anode photomultiplier tubes. In this paper, it is described the instrumentation and setup used to characterize the baseline photomultiplier solution (Hamamatsu R5900-00-M64) together with the scintillators and optical fibers for the SPD at LHCb.

  10. Effects of 1- and 2-MeV electrons on photomultiplier tubes

    Science.gov (United States)

    Beatty, M. E., III; Debnam, W. J., Jr.; Meredith, B. D.

    1976-01-01

    Various types of photomultiplier tubes useful for space applications were irradiated with 1- and 2-MeV electrons at Van Allen radiation belt fluxes of 100,000 to 10 millions electrons/sq cm-sec. The increase in the dark current due to electron irradiation was observed at various bias voltages under worst-case conditions (no shielding). Results were presented in the form of dark current plotted against electron flux. All the tubes tested showed extremely large increases in dark current. Tube types 541A, 6217, 6199, and 6903 exhibited the largest increases under irradiation, whereas type 1P22 was affected the least. All the damage observed was transient. The luminescence produced in the optical window probably accounts for a large part of the dark-current increases, but there were some effects possibly due to direct irradiation of the photocathode and dynode chain.

  11. Development of 2D-ACAR apparatus using position-sensitive photomultiplier tubes

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Yasuyoshi; Saito, Haruo; Iwata, Tetsuya; Nagashima, Yasuyuki; Hyodo, Toshio [Tokyo Univ. (Japan). Coll. of Arts and Sciences; Uchida, Hiroshi; Omura, Tomohide

    1997-03-01

    A new two-dimensional angular correlation of annihilation radiation apparatus is described. Position-sensitive photomultiplier tubes coupled with two-dimensional arrays of small BGO scintillator blocks make simple and compact position-sensitive {gamma}-ray detectors. With a sample-detector distance of 5m, an angular resolution of 1.1 mrad FWHM and a coincidence count rate of {approx}2.4 c.p.s. per mCi are obtained. Its performance is demonstrated by the result of a test measurement for KI crystal in which non-localized positronium exists at low temperatures. (author)

  12. Radionuclide mapping using a position sensitive photomultiplier tube and a germanium detector

    International Nuclear Information System (INIS)

    Dewaraja, Y.K.; He, Z.; Fleming, R.F.; Wehe, D.K.; Fleming, R.H.

    1995-01-01

    This paper demonstrates simultaneous two-dimensional mapping of multiple radionuclides which are present in a sample. The technique, which is based on position sensitive beta-gamma coincidence measurement, is applicable to most radionuclides that decay by beta emission followed by the emission of a coincident gamma-ray. In the present works, a Position Sensitive Photomultiplier Tube [PSPMT] is used for imaging the beta particles while a Ge detector is used to identify the radionuclides by detecting the coincident gamma-rays

  13. Test of digital neutron–gamma discrimination with four different photomultiplier tubes for the NEutron Detector Array (NEDA)

    Energy Technology Data Exchange (ETDEWEB)

    Luo, X.L., E-mail: luo.xiaoliang@physics.uu.se [Department of Instrument Science and Technology, College of Mechatronics and Automation, National University of Defense Technology, Changsha (China); Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden); Modamio, V. [INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Padova (Italy); Nyberg, J. [Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden); Valiente-Dobón, J.J. [INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Padova (Italy); Nishada, Q. [Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden); Angelis, G. de [INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Padova (Italy); Agramunt, J. [IFIC-CSIC, University of Valencia, Valencia (Spain); Egea, F.J. [IFIC-CSIC, University of Valencia, Valencia (Spain); Faculty of Engineering and Natural Sciences, Istanbul Sabahattin Zaim University, Istanbul (Turkey); Erduran, M.N.; Ertürk, S. [Nigde Universitesi, Fen-Edebiyat Falkültesi, Fizik Bölümü, Nigde (Turkey); France, G. de [GANIL, CEA/DSAM and CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 05 (France); Gadea, A. [IFIC-CSIC, University of Valencia, Valencia (Spain); González, V. [Department of Electronic Engineering, University of Valencia, E-46071 Valencia (Spain); Hüyük, T. [IFIC-CSIC, University of Valencia, Valencia (Spain); Jaworski, G. [Faculty of Physics, Warsaw University of Technology, ul. Koszykowa 75, 00-662 Warszawa (Poland); Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5A, 02-093 Warszawa (Poland); Moszyński, M. [Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5A, 02-093 Warszawa (Poland); National Centre for Nuclear Research, A. Soltana 7, PL 05-400 Otwock-Swierk (Poland); and others

    2014-12-11

    A comparative study of the neutron–γ discrimination performance of a liquid scintillator detector BC501A coupled to four different 5 in. photomultiplier tubes (ET9390kb, R11833-100, XP4512 and R4144) was carried out. Both the Charge Comparison method and the Integrated Rise-Time method were implemented digitally to discriminate between neutrons and γ rays emitted by a {sup 252}Cf source. In both methods, the neutron–γ discrimination capabilities of the four photomultiplier tubes were quantitatively compared by evaluating their figure-of-merit values at different energy regions between 50 keVee and 1000 keVee. Additionally, the results were further verified qualitatively using time-of-flight to distinguish γ rays and neutrons. The results consistently show that photomultiplier tubes R11833-100 and ET9390kb generally perform best regarding neutron–γ discrimination with only slight differences in figure-of-merit values. This superiority can be explained by their relatively higher photoelectron yield, which indicates that a scintillator detector coupled to a photomultiplier tube with higher photoelectron yield tends to result in better neutron–γ discrimination performance. The results of this work will provide reference for the choice of photomultiplier tubes for future neutron detector arrays like NEDA.

  14. CLARO: an ASIC for high rate single photon counting with multi-anode photomultipliers

    Science.gov (United States)

    Baszczyk, M.; Carniti, P.; Cassina, L.; Cotta Ramusino, A.; Dorosz, P.; Fiorini, M.; Gotti, C.; Kucewicz, W.; Malaguti, R.; Pessina, G.

    2017-08-01

    The CLARO is a radiation-hard 8-channel ASIC designed for single photon counting with multi-anode photomultiplier tubes. Each channel outputs a digital pulse when the input signal from the photomultiplier crosses a configurable threshold. The fast return to baseline, typically within 25 ns, and below 50 ns in all conditions, allows to count up to 107 hits/s on each channel, with a power consumption of about 1 mW per channel. The ASIC presented here is a much improved version of the first 4-channel prototype. The threshold can be precisely set in a wide range, between 30 ke- (5 fC) and 16 Me- (2.6 pC). The noise of the amplifier with a 10 pF input capacitance is 3.5 ke- (0.6 fC) RMS. All settings are stored in a 128-bit configuration and status register, protected against soft errors with triple modular redundancy. The paper describes the design of the ASIC at transistor-level, and demonstrates its performance on the test bench.

  15. X-ray detection with a scintillating YAP-window hybrid photomultiplier tube

    CERN Document Server

    D'Ambrosio, C; Leutz, H; Puertolas, D; Rosso, E

    2000-01-01

    A YAP(YAlO/sub 3/:Ce)-scintillating window, coated on its inner surface with an S20-photocathode, seals a cross-focusing hybrid photomultiplier tube (HPMT) equipped with a small p-i-n anode of 2-mm diameter. This new radiation detector separates X-ray lines down to about 2-keV peak energy from the HPMT noise. Its detection efficiency for high gamma energies depends on the YAP-window thickness and amounts to about 18% attenuation at 400-keV energy in the present version. Competitive radiation detectors like Si photodiodes and Si drift chambers are discussed and compared to our prototype, with particular attention given to their energy resolution and noise performance, which limits their active area considerably. (19 refs).

  16. Characterization of photomultiplier tubes with a realistic model through GPU-boosted simulation

    Science.gov (United States)

    Anthony, M.; Aprile, E.; Grandi, L.; Lin, Q.; Saldanha, R.

    2018-02-01

    The accurate characterization of a photomultiplier tube (PMT) is crucial in a wide-variety of applications. However, current methods do not give fully accurate representations of the response of a PMT, especially at very low light levels. In this work, we present a new and more realistic model of the response of a PMT, called the cascade model, and use it to characterize two different PMTs at various voltages and light levels. The cascade model is shown to outperform the more common Gaussian model in almost all circumstances and to agree well with a newly introduced model independent approach. The technical and computational challenges of this model are also presented along with the employed solution of developing a robust GPU-based analysis framework for this and other non-analytical models.

  17. High Voltage Power Supply With High Output Current and Low Power Consumption for Photomultiplier Tubes

    Science.gov (United States)

    Cunha, José Paulo V. S.; Begalli, Marcia; Bellar, Maria Dias

    2012-04-01

    In some applications, photomultiplier tubes (PMTs) are powered by battery based circuits, where the available energy is severely limited. The most simple approach to design high voltage power supplies (HVPS) for PMTs has considered resistive voltage dividers in order to bias the dynodes. However, this approach usually results in high power losses and, consequently, this undermines the PMT performance. In this work, the proposed solution is the use of a power circuit based on the forward converter connected to a transformer built with several secondary windings. Each secondary voltage is rectified and filtered to eliminate voltage ripple. Each dynode voltage is supplied by a rectified secondary voltage. The proposed topology provides low power consumption as well as low sensitivity of the PMT gain with respect to the dynode currents. Taking into account the Waste Electrical and Electronic Equipment Directive (WEEE), this HVPS has been designed to allow the recycling of old PMTs.

  18. A Near-Infrared Optical Tomography System Based on Photomultiplier Tube

    Directory of Open Access Journals (Sweden)

    Huacheng Feng

    2007-01-01

    Full Text Available Diffuse optical tomography (DOT is a rapidly growing discipline in recent years. It plays an important role in many fields, such as detecting breast cancer and monitoring the cerebra oxygenation. In this paper, a relatively simple, inexpensive, and conveniently used DOT system is presented in detail, in which only one photomultiplier tube is employed as the detector and an optical multiplexer is used to alter the detector channels. The 32-channel imager is consisted of 16-launch fibers and 16-detector fibers bundles, which works in the near-infrared (NIR spectral range under continuous-wave (CW model. The entire imaging system can work highly automatically and harmoniously. Experiments based on the proposed imaging system were performed, and the desired results can be obtained. The experimental results suggested that the proposed imaging instrumentation is effective.

  19. Characterization of photo-multiplier tube as ex-vessel radiation detector in tokamak

    Science.gov (United States)

    Jo, Jungmin; Cheon, MunSeong; Kim, Junghee; An, YoungHwa; Park, Seungil; Chung, Kyoung-Jae; Hwang, Y. S.

    2017-09-01

    Feasibility of using conventional photo-multiplier tubes (PMTs) without a scintillator as an ex-vessel radiation detector in a tokamak environment is studied. Basic irradiation tests using standard gamma ray sources and a d-d neutron generator showed that the PMT is responding both to gamma photons and neutrons, possibly due to the direct generation of secondary electrons inside the PMT by the impingement of high energy photons. Because of the selective sensitivity of the PMT to hard x-ray and neutrons in ohmic and neutral beam injected plasmas, respectively, it is shown that the PMT with certain configuration can be utilized either to monitor the fluctuation in the fusion neutron generation rate or to study the behavior of runaway electrons in tokamaks.

  20. Evaluation of candidate photomultiplier tubes for the upgrade of the CDF end plug calorimeter

    International Nuclear Information System (INIS)

    Koska, W.; Delchamps, S.W.; Freeman, J.; Kinney, W.; Lewis, D.; Limon, P.; Strait, J.; Fiori, I.; Gallinaro, M.; Shen, Q.

    1994-01-01

    The Collider Detector at Fermilab is upgrading its end plug calorimeter from a gas detector system to one using scintillating tiles and wavelength shifting fibers. This tile-fiber calorimeter will be read out through 1,824 photomultiplier tubes. The performance requirements of the calorimeter require that the PMTs have good response to light in the 500 nm region, provide adequate amplification for signals from minimum ionizing particles yet provide linear response for peak anode currents up to 25 mA at a gain of 50,000, and fit into the restricted space at the rear of the plugs. This paper will describe the evaluation process used to determine the adequacy of the commercially available PMTs which appeared to meet these performance requirements

  1. Monte Carlo calculations of the optical coupling between bismuth germanate crystals and photomultiplier tubes

    International Nuclear Information System (INIS)

    Derenzo, S.E.; Riles, J.K.

    1981-10-01

    The high density and atomic number of bismuth germanate (Bi 4 Ge 3 O 12 or BGO) make it a very useful detector for positron emission tomography. Modern tomograph designs use large numbers of small, closely-packed crystals for high spatial resolution and high sensitivity. However, the low light output, the high refractive index (n=2.15), and the need for accurate timing make it important to optimize the transfer of light to the photomultiplier tube (PMT). We describe the results of a Monte Carlo computer program developed to study the effect of crystal shape, reflector type, and the refractive index of the PMT window on coupling efficiency. The program simulates total internal, external, and Fresnel reflection as well as internal absorption and scattering by bubbles

  2. LHCb: Characterisation and magnetic field properties of Multianode Photomultiplier tubes for the use in LHCb Upgrade RICH detectors

    CERN Multimedia

    Eisenhardt, S; Morris, A; Needham, M; Neill, J

    2013-01-01

    A key feature of the LHCb upgrade, scheduled for 2019, is to remove the first level trigger and its data reduction from 40MHz to 1MHz, which is implemented in the on-detector readout electronics. The consequence for the LHCb Ring Imaging Cherenkov (RICH) detectors is that the Hybrid Photon Detectors need to be replaced as the readout chip is embedded in the tubes. Baseline for replacement are Multianode Photomultiplier tubes (MaPMT) and new readout electronics. Here we report about characterisation studies of the model Hamamatsu R11265 in the effort to qualify them for use in the LHCb RICH upgrade. Comparisons to the known model R7600 are also made. Two types of readout electronics are used. Most measurements to characterise the properties of the MaPMTs are taken with a VME based reference readout, using a x100 linear amplification and the CAEN V792 12-bit charge integrating digitiser. This allows to derive the signal properties from fits to the single photon spectra. In addition a prototype readout using the...

  3. A useful method to monitor outputs from a pulsed light source and its application to rate effect studies in a photomultiplier tube

    CERN Document Server

    Takeuchi, Y; Kurashige, H; Matono, Y; Murakami, K; Nomura, T; Sakamoto, H; Sasao, N; Suehiro, M; Fukushima, Y; Ikegami, Y; Nakamura, T T; Taniguchi, T; Asai, M

    1999-01-01

    In order to study short-term gain stability in a photomultiplier tube at high counting rate, we constructed an LED pulsed light source and its output monitoring system. For the monitoring system, we employed a photon counting method using a photomultiplier as a monitor photon detector. It is found that the method offers a simple way to monitor outputs from a pulsed light source and that, together with an LED light source, it provides a useful method to investigate photomultiplier's rate effects.

  4. Replacement of a photomultiplier tube in a 2-inch thallium-doped sodium iodide gamma spectrometer with silicon photomultipliers and a light guide

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Kyu; Kim, Hyoung Taek; Kim, Jong Yul [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); and others

    2015-06-15

    The thallium-doped sodium iodide [NaI(Tl)] scintillation detector is preferred as a gamma spectrometer in many fields because of its general advantages. A silicon photomultiplier (SiPM) has recently been developed and its application area has been expanded as an alternative to photomultiplier tubes (PMTs). It has merits such as a low operating voltage, compact size, cheap production cost, and magnetic resonance compatibility. In this study, an array of SiPMs is used to develop an NaI(Tl) gamma spectrometer. To maintain detection efficiency, a commercial NaI(Tl) 2′ X 2′ scintillator is used, and a light guide is used for the transport and collection of generated photons from the scintillator to the SiPMs without loss. The test light guides were fabricated with polymethyl methacrylate and reflective materials. The gamma spectrometer systems were set up and included light guides. Through a series of measurements, the characteristics of the light guides and the proposed gamma spectrometer were evaluated. Simulation of the light collection was accomplished using the DETECT 97 code (A. Levin, E. Hoskinson, and C. Moison, University of Michigan, USA) to analyze the measurement results. The system, which included SiPMs and the light guide, achieved 14.11% full width at half maximum energy resolution at 662 keV.

  5. Replacement of a photomultiplier tube in a 2-inch thallium-doped sodium iodide gamma spectrometer with silicon photomultipliers and a light guide

    Directory of Open Access Journals (Sweden)

    Chankyu Kim

    2015-06-01

    Full Text Available The thallium-doped sodium iodide [NaI(Tl] scintillation detector is preferred as a gamma spectrometer in many fields because of its general advantages. A silicon photomultiplier (SiPM has recently been developed and its application area has been expanded as an alternative to photomultiplier tubes (PMTs. It has merits such as a low operating voltage, compact size, cheap production cost, and magnetic resonance compatibility. In this study, an array of SiPMs is used to develop an NaI(Tl gamma spectrometer. To maintain detection efficiency, a commercial NaI(Tl 2′ × 2′ scintillator is used, and a light guide is used for the transport and collection of generated photons from the scintillator to the SiPMs without loss. The test light guides were fabricated with polymethyl methacrylate and reflective materials. The gamma spectrometer systems were set up and included light guides. Through a series of measurements, the characteristics of the light guides and the proposed gamma spectrometer were evaluated. Simulation of the light collection was accomplished using the DETECT 97 code (A. Levin, E. Hoskinson, and C. Moison, University of Michigan, USA to analyze the measurement results. The system, which included SiPMs and the light guide, achieved 14.11% full width at half maximum energy resolution at 662 keV.

  6. The characterisation of the multianode photomultiplier tubes for the RICH-1 upgrade project at COMPASS

    Science.gov (United States)

    Abbon, P.; Alexeev, M.; Angerer, H.; Birsa, R.; Bordalo, P.; Bradamante, F.; Bressan, A.; Chiosso, M.; Ciliberti, P.; Colantoni, M. L.; Dafni, T.; Dalla Torre, S.; Delagnes, E.; Denisov, O.; Deschamps, H.; Diaz, V.; Dibiase, N.; Duic, V.; Eyrich, W.; Ferrero, A.; Finger, M.; Finger, M.; Fischer, H.; Gerassimov, S.; Giorgi, M.; Gobbo, B.; Hagemann, R.; von Harrach, D.; Heinsius, F. H.; Joosten, R.; Ketzer, B.; Kolosov, V. N.; Königsmann, K.; Konorov, I.; Kramer, D.; Kunne, F.; Lehmann, A.; Levorato, S.; Maggiora, A.; Magnon, A.; Mann, A.; Martin, A.; Menon, G.; Mutter, A.; Nähle, O.; Nerling, F.; Neyret, D.; Panzieri, D.; Paul, S.; Pesaro, G.; Pizzolotto, C.; Polak, J.; Rebourgeard, P.; Robinet, F.; Rocco, E.; Schiavon, P.; Schill, C.; Schoenmeier, P.; Schroeder, W.; Silva, L.; Slunecka, M.; Sozzi, F.; Steiger, L.; Sulc, M.; Svec, M.; Takekawa, S.; Tessarotto, F.; Teufel, A.; Wollny, H.

    2008-09-01

    A major upgrade of the Cherenkov photon detection system of COMPASS RICH-1 has been performed and it has been in operation since the 2006 physics run. The inner part of the photon detector has been replaced by a different technology in order to measure Cherenkov photons at high photoelectron rates, up to several times 10 6 per second and per channel. Cherenkov photons from 200 to 750 nm are detected by 576 multianode photomultiplier tubes (MAPMTs) with 16 channels each, coupled to individual fused silica lens telescopes and fast, high sensitivity and high time resolution electronics read-out. To guarantee an optimal performance of the complete system, parameters like dark current, gain, uniformity, relative quantum efficiency have been measured for a totality of more than 600 MAPMTs (about 10 000 channels) in a fully automated test-stand, developed for this purpose. The ideal working point for each individual pixel could be ascertained by these measurements. In 2006 the newly equipped detector exhibited an excellent performance: about 56 detected photons per ring at saturation and a time resolution of better than 1 ns. We report about the MAPMT characterisation and the quality control set-up, protocol and results.

  7. A novel ZVS high voltage power supply for micro-channel plate photomultiplier tubes

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Chengquan [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi’an 710049 (China); Tian, Jinshou [Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119 (China); Liu, Zhen [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi’an 710049 (China); Qin, Hong [School of Computer Science and Technology, Xi' an University of Science and Technology, Xi' an 710054 (China); Wu, Shengli, E-mail: slwu@mail.xjtu.edu.cn [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi’an 710049 (China)

    2017-04-11

    A novel resonant high voltage power supply (HVPS) with zero voltage switching (ZVS), to reduce the voltage stress on switching devices and improve conversion efficiency, is proposed. The proposed HVPS includes a drive circuit, a transformer, several voltage multiplying circuits, and a regulator circuit. The HVPS contains several secondary windings that can be precisely regulated. The proposed HVPS performed better than the traditional resistor voltage divider, which requires replacing matching resistors resulting in resistor dispersibility in the Micro-Channel Plate (MCP). The equivalent circuit of the proposed HVPS was established and the operational principle analyzed. The entire switching element can achieve ZVS, which was validated by a simulation and experiments. The properties of this HVPS were tested including minimum power loss (240 mW), maximum power loss (1 W) and conversion efficiency (85%). The results of this research are that the proposed HVPS was suitable for driving the micro-channel plate photomultiplier tube (MCP-PMT). It was therefore adopted to test the MCP-PMT, which will be used in Daya Bay reactor neutrino experiment II in China.

  8. Extension of photomultiplier tube dynamic range for the LHAASO-KM2A electromagnetic particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Hongkui, E-mail: lvhk@ihep.ac.cn [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Sheng, Xiangdong; He, Huihai; Liu, Jia [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Zhongquan [Shandong University, Jinan 250100 (China); Hou, Chao; Zhao, Jing [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2015-05-01

    In the Large High Altitude Air Shower Observatory (LHAASO), the 1 km{sup 2} array (KM2A) requires linear measurement of optical intensity with a wide dynamic range. Over 5000 photomultiplier tubes (PMTs) are employed in this experiment and developed as “two outputs” device (anode and dynode) to meet the relevant requirements. In this study, the linearity of the anode and the eighth dynode (DY8), which is limited by space charge effects and mainly related to the relative dynode voltage ratios of the PMT divider, is examined. A voltage divider for the Hamamatsu R11102 PMT is designed and a dramatically enhanced linearity is demonstrated. Test results show that this design can cover a wide dynamic range from 20 to 2×10{sup 5} photoelectrons and achieve a peak anode current of 380 mA at a PMT gain of 10{sup 5}, which satisfies the requirements of KM2A electromagnetic particle detectors. The circuit design has been successfully simulated using the simulation software Multisim. The details of PMT performance tests and simulations are described.

  9. Extension of photomultiplier tube dynamic range for the LHAASO-KM2A electromagnetic particle detectors

    Science.gov (United States)

    Lv, Hongkui; Sheng, Xiangdong; He, Huihai; Liu, Jia; Zhang, Zhongquan; Hou, Chao; Zhao, Jing

    2015-05-01

    In the Large High Altitude Air Shower Observatory (LHAASO), the 1 km2 array (KM2A) requires linear measurement of optical intensity with a wide dynamic range. Over 5000 photomultiplier tubes (PMTs) are employed in this experiment and developed as "two outputs" device (anode and dynode) to meet the relevant requirements. In this study, the linearity of the anode and the eighth dynode (DY8), which is limited by space charge effects and mainly related to the relative dynode voltage ratios of the PMT divider, is examined. A voltage divider for the Hamamatsu R11102 PMT is designed and a dramatically enhanced linearity is demonstrated. Test results show that this design can cover a wide dynamic range from 20 to 2×105 photoelectrons and achieve a peak anode current of 380 mA at a PMT gain of 105, which satisfies the requirements of KM2A electromagnetic particle detectors. The circuit design has been successfully simulated using the simulation software Multisim. The details of PMT performance tests and simulations are described.

  10. Extension of photomultiplier tube dynamic range for the LHAASO-KM2A electromagnetic particle detectors

    International Nuclear Information System (INIS)

    Lv, Hongkui; Sheng, Xiangdong; He, Huihai; Liu, Jia; Zhang, Zhongquan; Hou, Chao; Zhao, Jing

    2015-01-01

    In the Large High Altitude Air Shower Observatory (LHAASO), the 1 km 2 array (KM2A) requires linear measurement of optical intensity with a wide dynamic range. Over 5000 photomultiplier tubes (PMTs) are employed in this experiment and developed as “two outputs” device (anode and dynode) to meet the relevant requirements. In this study, the linearity of the anode and the eighth dynode (DY8), which is limited by space charge effects and mainly related to the relative dynode voltage ratios of the PMT divider, is examined. A voltage divider for the Hamamatsu R11102 PMT is designed and a dramatically enhanced linearity is demonstrated. Test results show that this design can cover a wide dynamic range from 20 to 2×10 5 photoelectrons and achieve a peak anode current of 380 mA at a PMT gain of 10 5 , which satisfies the requirements of KM2A electromagnetic particle detectors. The circuit design has been successfully simulated using the simulation software Multisim. The details of PMT performance tests and simulations are described

  11. Properties of 8-inch photomultiplier tubes for a large volume imaging water Cerenkov detector

    International Nuclear Information System (INIS)

    Oehler, Ch.

    1996-01-01

    In the Institut fuer Kernphysik I conceptional studies for a possible succession project for the KARMEN-ν-detector are performed. This design studies propose to build a large volume 1300 t imaging water Cerenkov detector. The main goal of this experiment will be the investigation of ν-e - -scattering in the medium energy range up to 50 MeV. The sensitive surface of this detector will be instrumented with about 3000 8-inch photomultiplier tubes (PMT) providing a coverage of 20%. In the framework of this detector design, studies of the properties of hemispherical 8-inch phototubes have been investigated in this work. The topic was to optimise the quality of the important PMT properties like time- and energy-resolution which are crucial to achieve the required spatial and angular resolutions. A second task of this work was to construct a test facility for the PMT, with the possibility to test large quantities. Monte Carlo calculations show that the required detector resolutions of σ E /E(E e ≤50 MeV)=5.2%+47%/√E, σ t (E e ∼30 MeV)=0.6 ns, σ x (E e ∼30 MeV)=13 cm, σ Θ (E e ∼30 MeV)=20 , can be achieved if the phototubes have a transit-time spread less than 1 ns. Up to now, two different 8-inch tubes are available and have been tested, the HAMAMATSU R5912 and the EMI 9353. (orig.)

  12. Performance of a C4F8O gas radiator ring imaging Cherenkov detector using multi-anode photomultiplier tubes

    International Nuclear Information System (INIS)

    Artuso, M.; Boulahouache, C.; Blusk, S.; Butt, J.; Dorjkhaidav, O.; Menaa, N.; Mountain, R.; Muramatsu, H.; Nandakumar, R.; Randrianarivony, K.; Sia, R.; Skwarnicki, T.; Stone, S.; Wang, J.C.; Zhang, K.

    2006-01-01

    We report on tests of a novel ring imaging Cherenkov (RICH) detection system consisting of a 3-m-long gaseous C 4 F 8 O radiator, a focusing mirror, and a photon detector array based on Hamamatsu multi-anode photomultiplier tubes. This system was developed to identify charged particles in the momentum range from 3 to 70GeV/c for the BTeV experiment

  13. Analysis of single-photon time resolution of FBK silicon photomultipliers

    International Nuclear Information System (INIS)

    Acerbi, Fabio; Ferri, Alessandro; Gola, Alberto; Zorzi, Nicola; Piemonte, Claudio

    2015-01-01

    We characterized and analyzed an important feature of silicon photomultipliers: the single-photon time resolution (SPTR). We characterized the SPTR of new RGB (Red–Green–Blue) type Silicon Photomultipliers and SPADs produced at FBK (Trento, Italy), studying its main limiting factors. We compared time resolution of 1×1 mm 2 and 3×3 mm 2 SiPMs and a single SiPM cell (i.e. a SPAD with integrated passive-quenching), employing a mode-locked pulsed laser with 2-ps wide pulses. We estimated the contribution of front-end electronic-noise, of cell-to-cell uniformity, and intrinsic cell time-resolution. At a single-cell level, we compared the results obtained with different layouts. With a circular cell with a top metallization covering part of the edge and enhancing the signal extraction, we reached ~20 ps FWHM of time resolution

  14. Analysis of single-photon time resolution of FBK silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Acerbi, Fabio, E-mail: acerbi@fbk.eu; Ferri, Alessandro; Gola, Alberto; Zorzi, Nicola; Piemonte, Claudio

    2015-07-01

    We characterized and analyzed an important feature of silicon photomultipliers: the single-photon time resolution (SPTR). We characterized the SPTR of new RGB (Red–Green–Blue) type Silicon Photomultipliers and SPADs produced at FBK (Trento, Italy), studying its main limiting factors. We compared time resolution of 1×1 mm{sup 2} and 3×3 mm{sup 2} SiPMs and a single SiPM cell (i.e. a SPAD with integrated passive-quenching), employing a mode-locked pulsed laser with 2-ps wide pulses. We estimated the contribution of front-end electronic-noise, of cell-to-cell uniformity, and intrinsic cell time-resolution. At a single-cell level, we compared the results obtained with different layouts. With a circular cell with a top metallization covering part of the edge and enhancing the signal extraction, we reached ~20 ps FWHM of time resolution.

  15. Studies of relative gain and timing response of fine-mesh photomultiplier tubes in high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Sulkosky, V.; Allison, L.; Barber, C.; Cao, T.; Ilieva, Y.; Jin, K.; Kalicy, G.; Park, K.; Ton, N.; Zheng, X.

    2016-08-01

    We investigated the use of Hamamatsu fine-mesh photomultiplier tube assemblies H6152-70 and H6614-70 with regards to their gain and timing resolution in magnetic fields up to 1.9 T. Our results show that the H6614-70 assembly can operate reliably in magnetic fields exceeding 1.5 T, while preserving a reasonable timing resolution even with a gain reduction of a factor of ~100. The reduction of the relative gain of the H6152-70 is similar to the H6614-70's near 1.5 T, but its timing resolution worsens considerably at this high field.

  16. Design and testing of a magnetic shield for the Thomson scattering photomultiplier tubes in the stray fields of the ERASMUS tokamak

    International Nuclear Information System (INIS)

    Desoppere, E.; Van Oost, G.

    1983-01-01

    A multiple coaxial shield system has been designed for the photomultiplier tubes of the ERASMUS tokamak Thomson scattering diagnostic. A stray field of 75 x 10 -4 T was reduced to 0.01 x 10 -4 T for a field parallel to the tube axis, and to 0.03 x 10 -4 T for a perpendicular field

  17. Single photon timing resolution and detection efficiency of the IRST silicon photo-multipliers

    International Nuclear Information System (INIS)

    Collazuol, G.; Ambrosi, G.; Boscardin, M.; Corsi, F.; Dalla Betta, G.F.; Del Guerra, A.; Dinu, N.; Galimberti, M.; Giulietti, D.; Gizzi, L.A.; Labate, L.; Llosa, G.; Marcatili, S.; Morsani, F.; Piemonte, C.; Pozza, A.; Zaccarelli, L.; Zorzi, N.

    2007-01-01

    Silicon photo-multipliers (SiPM) consist in matrices of tiny, passive quenched avalanche photo-diode cells connected in parallel via integrated resistors and operated in Geiger mode. Novel types of SiPM are being developed at FBK-IRST (Trento, Italy). Despite their classical shallow junction n-on-p structure the devices are unique in their enhanced photo-detection efficiency (PDE) for short-wavelengths and in their low level of dark rate and excess noise factor. After a summary of the extensive SiPM characterization we will focus on the study of PDE and the single photon timing resolution

  18. Light yield of an undoped CsI crystal coupled directly to a photomultiplier tube at 77 Kelvin

    International Nuclear Information System (INIS)

    Liu, J.; Soma, A.K.; Yamashita, M.

    2016-01-01

    A light yield of 20.4 ± 0.8 photoelectrons/keV was achieved with an undoped CsI crystal coupled directly to a photomultiplier tube at 77 Kelvin. This is by far the largest yield in the world achieved with CsI crystals. An energy threshold that is several times lower than the current dark matter experiments utilizing CsI(Tl) crystals may be achievable using this technique. Together with novel CsI crystal purification methods, the technique may be used to improve the sensitivities of dark matter and coherent elastic neutrino-nucleus scattering experiments. Also measured were the scintillation light decay constants of the undoped CsI crystal at both room temperature and 77 Kelvin. The results are consistent with those in the literature.

  19. A novel compensation method for the anode gain non-uniformity of multi-anode photomultiplier tubes.

    Science.gov (United States)

    Lee, Chan Mi; Il Kwon, Sun; Ko, Guen Bae; Ito, Mikiko; Yoon, Hyun Suk; Lee, Dong Soo; Hong, Seong Jong; Lee, Jae Sung

    2012-01-07

    The position-sensitive multi-anode photomultiplier tube (MA-PMT) is widely used in high-resolution scintillation detectors. However, the anode gain nonuniformity of this device is a limiting factor that degrades the intrinsic performance of the detector module. The aim of this work was to develop a gain compensation method for the MA-PMT and evaluate the resulting enhancement in the performance of the detector. The method employs a circuit that is composed only of resistors and is placed between the MA-PMT and a resistive charge division network (RCN) used for position encoding. The goal of the circuit is to divide the output current from each anode, so the same current flows into the RCN regardless of the anode gain. The current division is controlled by the combination of a fixed-value series resistor with an output impedance that is much larger than the input impedance of the RCN, and a parallel resistor, which detours part of the current to ground. PSpice simulations of the compensation circuit and the RCN were performed to determine optimal values for the compensation resistors when used with Hamamatsu H8500 MAPMTs. The intrinsic characteristics of a detector module consisting of this MA-PMT and a lutetium-gadolinium-oxyorthosilicate (LGSO) crystal array were tested with and without the gain compensation method. In simulation, the average coefficient of variation and max/min ratio decreased from 15.7% to 2.7% and 2.0 to 1.2, respectively. In the flood map of the LGSO-H8500 detector, the uniformity of the photopeak position for individual crystals and the energy resolution were much improved. The feasibility of the method was shown by applying it to an octagonal prototype positron emission tomography scanner.

  20. Time-resolved single-photon detection module based on silicon photomultiplier: A novel building block for time-correlated measurement systems

    Energy Technology Data Exchange (ETDEWEB)

    Martinenghi, E., E-mail: edoardo.martinenghi@polimi.it; Di Sieno, L.; Contini, D.; Dalla Mora, A. [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Sanzaro, M. [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Pifferi, A. [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2016-07-15

    We present the design and preliminary characterization of the first detection module based on Silicon Photomultiplier (SiPM) tailored for single-photon timing applications. The aim of this work is to demonstrate, thanks to the design of a suitable module, the possibility to easily exploit SiPM in many applications as an interesting detector featuring large active area, similarly to photomultipliers tubes, but keeping the advantages of solid state detectors (high quantum efficiency, low cost, compactness, robustness, low bias voltage, and insensitiveness to magnetic field). The module integrates a cooled SiPM with a total photosensitive area of 1 mm{sup 2} together with the suitable avalanche signal read-out circuit, the signal conditioning, the biasing electronics, and a Peltier cooler driver for thermal stabilization. It is able to extract the single-photon timing information with resolution better than 100 ps full-width at half maximum. We verified the effective stabilization in response to external thermal perturbations, thus proving the complete insensitivity of the module to environment temperature variations, which represents a fundamental parameter to profitably use the instrument for real-field applications. We also characterized the single-photon timing resolution, the background noise due to both primary dark count generation and afterpulsing, the single-photon detection efficiency, and the instrument response function shape. The proposed module can become a reliable and cost-effective building block for time-correlated single-photon counting instruments in applications requiring high collection capability of isotropic light and detection efficiency (e.g., fluorescence decay measurements or time-domain diffuse optics systems).

  1. The photomultiplier handbook

    CERN Document Server

    Wright, A G

    2017-01-01

    Photomultipliers are extremely sensitive light detectors that can detect single photons. In multiplying the charge produced by incident light by up to 100 million times, these devices are essential to a wide range of functions, from medical instrumentation to astronomical observations. This complete and authoritative guide will provide students, practitioners, and researchers with a deeper understanding of the operating principles of these devices. Authored by an experienced user and manufacturer of photomultipliers, this handbook gives the reader insights into photomultiplier behaviour as a means to optimize performance. Diffuse and low level light sources are best served with a photomultiplier for the detection of single photon emissions. Light detection and electron multiplication are statistical in nature and the mathematics of these processes is derived from first principles. The book covers other related topics such as scintillation counting, light guides, and large area detectors. The usually complicat...

  2. A position-sensitive scintillation detector for two-dimensional angular correlation of annihilation radiation using metal-package position-sensitive photomultiplier tubes

    International Nuclear Information System (INIS)

    Inoue, Koji; Nagai, Yasuyoshi; Saito, Haruo; Nagashima, Yasuyuki; Hyodo, Toshio; Muramatsu, Shinichi; Nagai, Shota

    1999-01-01

    We have constructed and tested a prototype of a new position sensitive γ-ray detector which consists of an array of 2.6x2.6x18 mm 3 BGO scintillator blocks, a light guide, and four metal-package position-sensitive photomultiplier tubes (R5900-00-C8) recently developed by Hamamatsu Photonics Co. Ltd. Scalability of the detector of this type makes it possible to construct a larger detector using many PS-PMTs, which will be useful for the two-dimensional angular correlation of annihilation radiation apparatus

  3. Progress in CsI-wire chamber imaging photomultipliers and single electron counters

    International Nuclear Information System (INIS)

    Breskin, A.; Chechik, R.; Dagendorf, V.; Pansky, A.; Vartsky, D.

    1990-10-01

    Electrons photoproduced by UV-photons on a CsI photocathode, or deposited by ionizing particles and ultrasoft x- rays in low-pressure gas media, are efficiently detected in low pressure multistep avalanche electron multipliers. A solid photocathode avalanche chamber (SPAC) imaging photomultiplier was coupled to a Xe-filled gas scintillation detector. Its performance when exposed to 60 KeV x rays is presented. The stability of the CsI photocathode is discussed in detail. The latest experimental results from primary ionization cluster counting of charged particles and ultrasoft x-rays are presented. UV laser-induced ionization and Monte-Carlo simulations are used to study the processes involved. (author)

  4. A model for the Global Quantum Efficiency for a TPB-based wavelength-shifting system used with photomultiplier tubes in liquid argon in MicroBooNE

    Energy Technology Data Exchange (ETDEWEB)

    Pate, S. F. [New Mexico State U.; Wester, T. [MIT, Cambridge, Dept. Phys.; Bugel, L. [MIT, Cambridge, Dept. Phys.; Conrad, J. [MIT, Cambridge, Dept. Phys.; Henderson, E. [New Mexico State U.; Jones, B. J.P. [Texas U., Arlington; McLean, A. I.L. [New Mexico State U.; Moon, J. S. [MIT, Cambridge, Dept. Phys.; Toups, M. [Fermilab; Wongjirad, T. [MIT, Cambridge, Dept. Phys.

    2018-02-28

    We present a model for the Global Quantum Efficiency (GQE) of the MicroBooNE optical units. An optical unit consists of a flat, circular acrylic plate, coated with tetraphenyl butadiene (TPB), positioned near the photocathode of a 20.2-cm diameter photomultiplier tube. The plate converts the ultra-violet scintillation photons from liquid argon into visible-spectrum photons to which the cryogenic phototubes are sensitive. The GQE is the convolution of the efficiency of the plates that convert the 128 nm scintillation light from liquid argon to visible light, the efficiency of the shifted light to reach the photocathode, and the efficiency of the cryogenic photomultiplier tube. We develop a GEANT4-based model of the optical unit, based on first principles, and obtain the range of probable values for the expected number of detected photoelectrons ($N_{\\rm PE}$) given the known systematic errors on the simulation parameters. We compare results from four measurements of the $N_{\\rm PE}$ determined using alpha-particle sources placed at two distances from a TPB-coated plate in a liquid argon cryostat test stand. We also directly measured the radial dependence of the quantum efficiency, and find that this has the same shape as predicted by our model. Our model results in a GQE of $0.0055\\pm0.0009$ for the MicroBooNE optical units. While the information shown here is MicroBooNE specific, the approach to the model and the collection of simulation parameters will be widely applicable to many liquid-argon-based light collection systems.

  5. A model for the Global Quantum Efficiency for a TPB-based wavelength-shifting system used with photomultiplier tubes in liquid argon in MicroBooNE

    Science.gov (United States)

    Pate, S. F.; Wester, T.; Bugel, L.; Conrad, J.; Henderson, E.; Jones, B. J. P.; McLean, A. I. L.; Moon, J. S.; Toups, M.; Wongjirad, T.

    2018-02-01

    We present a model for the Global Quantum Efficiency (GQE) of the MicroBooNE optical units. An optical unit consists of a flat, circular acrylic plate, coated with tetraphenyl butadiene (TPB), positioned near the photocathode of a 20.2-cm diameter photomultiplier tube. The plate converts the ultra-violet scintillation photons from liquid argon into visible-spectrum photons to which the cryogenic phototubes are sensitive. The GQE is the convolution of the efficiency of the plates that convert the 128 nm scintillation light from liquid argon to visible light, the efficiency of the shifted light to reach the photocathode, and the efficiency of the cryogenic photomultiplier tube. We develop a GEANT4-based model of the optical unit, based on first principles, and obtain the range of probable values for the expected number of detected photoelectrons (NPE) given the known systematic errors on the simulation parameters. We compare results from four measurements of the NPE determined using alpha-particle sources placed at two distances from a TPB-coated plate in a liquid argon cryostat test stand. We also directly measured the radial dependence of the quantum efficiency, and find that this has the same shape as predicted by our model. Our model results in a GQE of 0.0055±0.0009 for the MicroBooNE optical units. While the information shown here is MicroBooNE specific, the approach to the model and the collection of simulation parameters will be widely applicable to many liquid-argon-based light collection systems.

  6. Geneva University - Silicon photomultiplier : features and applications

    CERN Multimedia

    Université de Genève

    2012-01-01

    GENEVA UNIVERSITY École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92   Wednesday 7 March 2012 SEMINAIRE DE PHYSIQUE CORPUSCULAIRE 11.15 a.m. - Science II, Auditoire 1S081, 30, quai Ernest-Ansermet, 1211 Genève 4 SILICON PHOTOMULTIPLIER : FEATURES AND APPLICATIONS Dr Giulio SARACINO   University of Naples, Federico II   Silicon photomultipliers were developed about ten years ago and their use, unlike traditional photomultiplier tubes, is increasing more and more. They are an evolution of the avalanche photodiode working in Geiger mode regime. Hundreds of such diodes are connected in parallel, allowing single photon response, high detection efficiency, high gain at low bias voltage and very good timing performance. In spite of their Geiger regime, they can be considered linear devices, until the number of photon...

  7. A depth-encoding PET detector that uses light sharing and single-ended readout with silicon photomultipliers.

    Science.gov (United States)

    Kuang, Zhonghua; Yang, Qian; Wang, Xiaohui; Fu, Xin; Ren, Ning; Sang, Ziru; Wu, San; Zheng, Yunfei; Zhang, Xianming; Hu, Zhanli; Du, Junwei; Liang, Dong; Liu, Xin; Zheng, Hairong; Yang, Yongfeng

    2018-02-13

    Detectors with depth-encoding capability and good timing resolution are required to develop high-performance whole-body or total-body PET scanners. In this work, depth-encoding PET detectors that use light sharing between two discrete crystals and single-ended readout with silicon photomultipliers (SiPMs) were manufactured and evaluated. The detectors consisted of two unpolished 3  ×  3  ×  20 mm 3 LYSO crystals with different coupling materials between them and were read out by Hamamatsu 3  ×  3 mm 2 SiPMs with one-to-one coupling. The ratio of the energy of one SiPM to the total energy of two SiPMs was used to measure the depth of interaction (DOI). Detectors with different coupling materials in-between the crystals were measured in the singles mode in an effort to obtain detectors that can provide good DOI resolution. The DOI resolution and energy resolution of three types of detector were measured and the timing resolution was measured for the detector with the best DOI and energy resolution. The optimum detector, with 5 mm optical glue, a 9 mm triangular ESR and a 6 mm rectangular ESR in-between the unpolished crystals, provides a DOI resolution of 2.65 mm, an energy resolution of 10.0% and a timing resolution of 427 ps for events of E  >  400 keV. The detectors simultaneously provide good DOI and timing resolution, and show great promise for the development of high-performance whole-body and total-body PET scanners.

  8. A depth-encoding PET detector that uses light sharing and single-ended readout with silicon photomultipliers

    Science.gov (United States)

    Kuang, Zhonghua; Yang, Qian; Wang, Xiaohui; Fu, Xin; Ren, Ning; Sang, Ziru; Wu, San; Zheng, Yunfei; Zhang, Xianming; Hu, Zhanli; Du, Junwei; Liang, Dong; Liu, Xin; Zheng, Hairong; Yang, Yongfeng

    2018-02-01

    Detectors with depth-encoding capability and good timing resolution are required to develop high-performance whole-body or total-body PET scanners. In this work, depth-encoding PET detectors that use light sharing between two discrete crystals and single-ended readout with silicon photomultipliers (SiPMs) were manufactured and evaluated. The detectors consisted of two unpolished 3  ×  3  ×  20 mm3 LYSO crystals with different coupling materials between them and were read out by Hamamatsu 3  ×  3 mm2 SiPMs with one-to-one coupling. The ratio of the energy of one SiPM to the total energy of two SiPMs was used to measure the depth of interaction (DOI). Detectors with different coupling materials in-between the crystals were measured in the singles mode in an effort to obtain detectors that can provide good DOI resolution. The DOI resolution and energy resolution of three types of detector were measured and the timing resolution was measured for the detector with the best DOI and energy resolution. The optimum detector, with 5 mm optical glue, a 9 mm triangular ESR and a 6 mm rectangular ESR in-between the unpolished crystals, provides a DOI resolution of 2.65 mm, an energy resolution of 10.0% and a timing resolution of 427 ps for events of E  >  400 keV. The detectors simultaneously provide good DOI and timing resolution, and show great promise for the development of high-performance whole-body and total-body PET scanners.

  9. Development of gaseous photomultiplier

    International Nuclear Information System (INIS)

    Tokanai, F.; Sumiyoshi, T.; Sugiyama, H.; Okada, T.

    2014-01-01

    We have been developing gaseous photomultiplier tubes (PMTs) with alkali photocathode combined with micropattern gas detectors (MPGDs). The potential advantage of the gaseous PMT is that it can achieve a very large effective area with adequate position and timing resolutions. In addition, it will be easily operated under a very high magnetic field, compared with the conventional vacuum-based PMT. To evaluate the gaseous PMTs filled with Ne and Ar based gas mixture, we have developed gaseous PMTs with an alkali photocathode combined with MPGDs such as a glass capillary plate, GEM, and Micromegas detector. We describe the recent development of the gaseous PMTs, particularly the production of the photocathode, gas gain, ion and photon feedbacks, quantum efficiency, and the characteristics in the magnetic field environment. (author)

  10. Timing coincidence studies with fast photomultipliers

    International Nuclear Information System (INIS)

    Raoof, M.A.; Raoof, S.A.

    1981-01-01

    The time response of RCA C70045D photomultipliers was studied using a subnanosecond light flasher. The tubes, which have an output rise time of approximately 0.5 ns, were used in coincidence to study the variations in the fwhm of the time spectrum over a certain dynamic range of pulse amplitudes for both leading edge and constant fraction discrimination. A comparison has also been made for the measured time resolutions with some of the other fast photomultipliers. (orig.)

  11. The dynamic single-tube concept; Le mono-tube dynamique

    Energy Technology Data Exchange (ETDEWEB)

    Rivet, P. [Ste MC International (France)

    1997-12-31

    In the framework of greenhouse gas emission reduction and the utilization of cooling intermediate fluids with indirect refrigerating systems, a new concept of dynamical single-tube has been developed, which allows for the simultaneous cold distribution from a centralized plant towards various required temperature systems (as for example in a supermarket refrigerating system) with optimized efficiency, fluid flow and defrosting conditions; moreover, the dynamic single-tube concept is very well adapted to two-phase flows

  12. Behaviour of an irradiated photomultiplier

    International Nuclear Information System (INIS)

    Verdant, R.

    1967-04-01

    With the aim of using scintillation detectors for the starting-up, the study of transient phenomena, the control or the safety of a nuclear reactor or of a critical assembly, the behaviour of 8 photomultipliers (Radiotechnique 51 AVP and UVP, and EMI 9524 B) has been studied in the gamma flux of 1 to 10 3 Rh -1 in a storage well, and in an EL 2 reactor channel where the exposures varied between 1 to 2 x 10 3 Rh -1 and 6 x 10 5 to 5 x 10 7 n.cm -2 .s -1 . Spurious pulses are produced by this radiation at the photomultiplier anode. By comparing the amplitudes of these pulses to those produced by a NaI scintillator, it was observed that their maximum energy level was about 100 keV at 10 3 Rh -1 in the gamma flow of the storage well and from 200 to 400 keV at 10 3 Rh -1 and 10 7 n.cm -2 .s -1 in the reactor channel. Furthermore, the detection of a luminous reference pulse corresponding to 200 keV (NaI) is only perturbed at values Of above a few hundred Rh -1 the γ radiation alone, and above 5 x 10 6 n.cm -2 .s -1 and ∼ 500 Rh -1 in the reactor channel. The dispersion of these results is of the order of 2 for the 8 tubes tested. The main part of the γ radiation effect is attributed to the Cerenkov effect in the window of the photomultiplier. The possibility of separating the respective effects of neutrons and of γ radiation is considered. No marked evolution in the photomultiplier parameters during exposure was noticed. Their characteristics were not modified by the doses received, the largest of which attained 4 x 10 12 neutrons.cm -2 and ≅ 3 x 10 4 roentgens. The advantages of using photomultipliers and fast circuits for widening the field of use of photomultipliers under irradiation is stressed. (author) [fr

  13. Single-site neural tube closure in human embryos revisited.

    Science.gov (United States)

    de Bakker, Bernadette S; Driessen, Stan; Boukens, Bastiaan J D; van den Hoff, Maurice J B; Oostra, Roelof-Jan

    2017-10-01

    Since the multi-site closure theory was first proposed in 1991 as explanation for the preferential localizations of neural tube defects, the closure of the neural tube has been debated. Although the multi-site closure theory is much cited in clinical literature, single-site closure is most apparent in literature concerning embryology. Inspired by Victor Hamburgers (1900-2001) statement that "our real teacher has been and still is the embryo, who is, incidentally, the only teacher who is always right", we decided to critically review both theories of neural tube closure. To verify the theories of closure, we studied serial histological sections of 10 mouse embryos between 8.5 and 9.5 days of gestation and 18 human embryos of the Carnegie collection between Carnegie stage 9 (19-21 days) and 13 (28-32 days). Neural tube closure was histologically defined by the neuroepithelial remodeling of the two adjoining neural fold tips in the midline. We did not observe multiple fusion sites in neither mouse nor human embryos. A meta-analysis of case reports on neural tube defects showed that defects can occur at any level of the neural axis. Our data indicate that the human neural tube fuses at a single site and, therefore, we propose to reinstate the single-site closure theory for neural tube closure. We showed that neural tube defects are not restricted to a specific location, thereby refuting the reasoning underlying the multi-site closure theory. Clin. Anat. 30:988-999, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Optimization of the Single Staggered Wire and Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Arsana I Made

    2016-01-01

    Full Text Available Wire and tube heat exchanger consists of a coiled tube, and wire is welded on the two sides of it in normal direction of the tube. Generally,wire and tube heat exchanger uses inline wire arrangement between the two sides, whereas in this study, it used staggered wire arrangement that reduces the restriction of convection heat transfer. This study performed the optimization of single staggered wire and tube heat exchanger to increase the capacity and reduce the mass of the heat exchanger. Optimization was conducted with the Hooke-Jeeves method, which aims to optimize the geometry of the heat exchanger, especially on the diameter (dw and the distance between wires (pw. The model developed to present heat transfer correlations on single staggered wire and tube heat exchanger was valid. The maximum optimization factor obtained when the diameter wire was 0.9 mm and the distance between wires (pw was 11 mm with the fref value = 1.5837. It means that the optimized design only using mass of 59,10 % and could transfer heat about 98,5 % from the basis design.

  15. Characterization of New-Generation Silicon Photomultipliers for Nuclear Security Applications

    Directory of Open Access Journals (Sweden)

    Wonders Marc A.

    2018-01-01

    Full Text Available Silicon photomultipliers have received a great deal of interest recently for use in applications spanning a wide variety of fields, including nuclear safeguards and nonproliferation. For nuclear-related applications, the ability of silicon photomultipliers to discriminate neutrons from gamma rays using pulse shape discrimination when coupled with certain organic scintillators is a characteristic of utmost importance. This work reports on progress characterizing the performance of twenty different silicon photomultipliers from five manufacturers with an emphasis on pulse shape discrimination performance and timing. Results are presented on pulse shape discrimination performance as a function of overvoltage for 6-mm x 6-mm silicon photomultipliers, and the time response to stilbene is characterized for silicon photomultipliers of three different sizes. Finally, comparison with a photomultiplier tube shows that some new-generation silicon photomultipliers can perform as well as photomultiplier tubes in neutron-gamma ray discrimination.

  16. Characterization of New-Generation Silicon Photomultipliers for Nuclear Security Applications

    Science.gov (United States)

    Wonders, Marc A.; Chichester, David L.; Flaska, Marek

    2018-01-01

    Silicon photomultipliers have received a great deal of interest recently for use in applications spanning a wide variety of fields, including nuclear safeguards and nonproliferation. For nuclear-related applications, the ability of silicon photomultipliers to discriminate neutrons from gamma rays using pulse shape discrimination when coupled with certain organic scintillators is a characteristic of utmost importance. This work reports on progress characterizing the performance of twenty different silicon photomultipliers from five manufacturers with an emphasis on pulse shape discrimination performance and timing. Results are presented on pulse shape discrimination performance as a function of overvoltage for 6-mm x 6-mm silicon photomultipliers, and the time response to stilbene is characterized for silicon photomultipliers of three different sizes. Finally, comparison with a photomultiplier tube shows that some new-generation silicon photomultipliers can perform as well as photomultiplier tubes in neutron-gamma ray discrimination.

  17. Single file diffusion into a semi-infinite tube.

    Science.gov (United States)

    Farrell, Spencer G; Brown, Aidan I; Rutenberg, Andrew D

    2015-11-23

    We investigate single file diffusion (SFD) of large particles entering a semi-infinite tube, such as luminal diffusion of proteins into microtubules or flagella. While single-file effects have no impact on the evolution of particle density, we report significant single-file effects for individually tracked tracer particle motion. Both exact and approximate ordering statistics of particles entering semi-infinite tubes agree well with our stochastic simulations. Considering initially empty semi-infinite tubes, with particles entering at one end starting from an initial time t = 0, tracked particles are initially super-diffusive after entering the system, but asymptotically diffusive at later times. For finite time intervals, the ratio of the net displacement of individual single-file particles to the average displacement of untracked particles is reduced at early times and enhanced at later times. When each particle is numbered, from the first to enter (n = 1) to the most recent (n = N), we find good scaling collapse of this distance ratio for all n. Experimental techniques that track individual particles, or local groups of particles, such as photo-activation or photobleaching of fluorescently tagged proteins, should be able to observe these single-file effects. However, biological phenomena that depend on local concentration, such as flagellar extension or luminal enzymatic activity, should not exhibit single-file effects.

  18. The single chest tube versus double chest tube application after pulmonary lobectomy: A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Xuefei Zhang

    2016-01-01

    Conclusion: Compared with the double chest tube, the single chest tube significantly decreases amount of drainage, duration of chest tube drainage, pain score, the number of patients who need thoracentesis, and cost. Although there is convincing evidence to confirm the results mentioned herein, they still need to be confirmed by large-sample, multicenter, randomized, controlled trials.

  19. Silicon Photomultiplier Performance in High ELectric Field

    Science.gov (United States)

    Montoya, J.; Morad, J.

    2016-12-01

    Roughly 27% of the universe is thought to be composed of dark matter. The Large Underground Xenon (LUX) relies on the emission of light from xenon atoms after a collision with a dark matter particle. After a particle interaction in the detector, two things can happen: the xenon will emit light and charge. The charge (electrons), in the liquid xenon needs to be pulled into the gas section so that it can interact with gas and emit light. This allows LUX to convert a single electron into many photons. This is done by applying a high voltage across the liquid and gas regions, effectively ripping electrons out of the liquid xenon and into the gas. The current device used to detect photons is the photomultiplier tube (PMT). These devices are large and costly. In recent years, a new technology that is capable of detecting single photons has emerged, the silicon photomultiplier (SiPM). These devices are cheaper and smaller than PMTs. Their performance in a high electric fields, such as those found in LUX, are unknown. It is possible that a large electric field could introduce noise on the SiPM signal, drowning the single photon detection capability. My hypothesis is that SiPMs will not observe a significant increase is noise at an electric field of roughly 10kV/cm (an electric field within the range used in detectors like LUX). I plan to test this hypothesis by first rotating the SiPMs with no applied electric field between two metal plates roughly 2 cm apart, providing a control data set. Then using the same angles test the dark counts with the constant electric field applied. Possibly the most important aspect of LUX, is the photon detector because it's what detects the signals. Dark matter is detected in the experiment by looking at the ratio of photons to electrons emitted for a given interaction in the detector. Interactions with a low electron to photon ratio are more like to be dark matter events than those with a high electron to photon ratio. The ability to

  20. Practical acoustic thermometry with twin-tube and single-tube sensors

    International Nuclear Information System (INIS)

    De Podesta, M.; Sutton, G.; Edwards, G.; Stanger, L.; Preece, H.

    2015-01-01

    Accurate measurement of high temperatures in a nuclear environment presents unique challenges. All secondary techniques inevitably drift because the thermometric materials in thermocouples and resistance sensors are sensitive not just to temperature, but also their own chemical and physical composition. The solution is to use primary methods that rely on fundamental links between measurable physical properties and temperature. In the nuclear field the best known technique is the measurement of Johnson Noise in a resistor (See Paper 80 at this conference). In this paper we describe the measurement of temperature in terms of the speed of sound in a gas confined in a tube - an acoustic waveguide. Acoustic thermometry is the most accurate technique of primary thermometry ever devised with the best uncertainty of measurement below 0.001 C. In contrast, the acoustic technique described in this work has a much larger uncertainty, approximately 1 deg. C. But the cost and ease of use are improved by several orders of magnitude, making implementation eminently practical. We first describe the basic construction and method of operation of thermometers using twin-tubes and single tubes. We then present results using a twin-tube design showing that showing long term stability (i.e. no detectable drift) at 700 deg. C over periods of several weeks. We then outline how the technique may be developed for different nuclear applications. (authors)

  1. Modeling Photo-multiplier Gain and Regenerating Pulse Height Data for Application Development

    Science.gov (United States)

    Aspinall, Michael D.; Jones, Ashley R.

    2018-01-01

    Systems that adopt organic scintillation detector arrays often require a calibration process prior to the intended measurement campaign to correct for significant performance variances between detectors within the array. These differences exist because of low tolerances associated with photo-multiplier tube technology and environmental influences. Differences in detector response can be corrected for by adjusting the supplied photo-multiplier tube voltage to control its gain and the effect that this has on the pulse height spectra from a gamma-only calibration source with a defined photo-peak. Automated methods that analyze these spectra and adjust the photo-multiplier tube bias accordingly are emerging for hardware that integrate acquisition electronics and high voltage control. However, development of such algorithms require access to the hardware, multiple detectors and calibration source for prolonged periods, all with associated constraints and risks. In this work, we report on a software function and related models developed to rescale and regenerate pulse height data acquired from a single scintillation detector. Such a function could be used to generate significant and varied pulse height data that can be used to integration-test algorithms that are capable of automatically response matching multiple detectors using pulse height spectra analysis. Furthermore, a function of this sort removes the dependence on multiple detectors, digital analyzers and calibration source. Results show a good match between the real and regenerated pulse height data. The function has also been used successfully to develop auto-calibration algorithms.

  2. Photomultiplier tube artifacts on 67Ga-citrate imaging caused by loss of correction floods due to an off-peak status of one head of a dual-head γ-camera.

    Science.gov (United States)

    Glaser, Joseph E; Song, Na; Jaini, Sridivya; Lorenzo, Ruth; Love, Charito

    2012-12-01

    γ-cameras use flood-field corrections to ensure image uniformity during clinical imaging. A loss or corruption of the correction data of one head of a dual-head camera can result in an off-peak artifactual appearance. We present our experience with the occurrence of such an incident on a (67)Ga scan. A patient was referred for a whole-body (67)Ga scan to evaluate for causes of neutropenic fever. Whole-body planar and static images of the head, chest, abdomen, pelvis, and lower extremities in multiple projections were obtained. Whole-body images showed decreased image quality on the anterior view obtained with detector 1 and an unremarkable posterior image obtained with detector 2. A problem with detector 2 was suspected, and additional static images were obtained after rotation of the detector heads. The posterior images taken with detector 1 showed photomultiplier tube outlines. The anterior images taken with detector 2 showed improved count and image quality. It was later found that the uniformity map for detector 2 had been lost and that this software malfunction led to the resulting imaging problem. When artifacts with an off-peak appearance are seen on scintigraphic images, evaluation of possible causes should include not only isotope window settings but also an incorrect or corrupted uniformity map.

  3. Position sensitive gaseous photomultipliers

    CERN Document Server

    Biteman, V; Peskov, Vladimir; Sakuraï, H; Silin, E; Sokolova, T; Radionov, I

    2001-01-01

    In this paper a simple design of a gaseous photomultiplier, sensitive up to visible light, is described. It consists of a parallel plate chamber combined with a solid photocathode through a capillary plate, which works in a transmission mode and serves to suppress photon feedback. Ion feedback was minimized through the optimization of the gas mixture. A gain >10 sup 3 was achieved.

  4. Condensation heat transfer of steam on a single horizontal tube

    Science.gov (United States)

    Graber, K. A.

    1983-06-01

    An experimental apparatus was designed, constructed and instrumented in an effort to systematically and carefully study the condensation heat-transfer coefficient on a single, horizontal tube. A smooth, thick-walled copper tube of length 133.5 mm, with an outside diameter of 15.9 mm and an inside diameter of 12.7 mm was instrumented with six wall thermocouples. The temperature rise across the test section was measured accurately using quartz crystal thermometers. The inside heat-transfer coefficient was determined using the Sieder-Tate correlation with leading coefficient of 0.029. Initial steam side data were taken at atmospheric pressure to test the data acquisition/reduction computer programs.

  5. Photomultiplier pulse Read Out system for the preshower detector of the LHCb experiment

    International Nuclear Information System (INIS)

    Ajaltouni, Z.; Bohner, G.; Cornat, R.; Deschamps, O.; Lecoq, J.; Monteil, S.; Perret, P.

    2003-01-01

    The second generation experiment for CP violation studies in B decays, LHCb, is a 20-m-long single-arm spectrometer to be installed on the future Large Hadron Collider at CERN. For its precision measurement purpose, it combines precise vertex location and particle identification, in addition to a performance trigger system able to cope with high flux. The first level of trigger is mainly based on the fast response of the calorimetric subsystem. Of major importance is the 6000 channels preshower detector that aims to validate the electromagnetic nature of calorimetric showers. It consists of two-radiation-length lead sheet in front of a scintillator plane. Scintillator signals are extracted from plastic cells using wavelength-shifting fibres coupled to multi-anode photomultiplier tubes. The preshower Read Out system has to cope with fluctuating photomultiplier pulses caused by small amounts of photoelectrons, in addition to strong constraints imposed by the 40 MHz LHC bunch-crossing frequency. A special Read Out electronics including perfect 40 MHz integrators able to shape fluctuating photomultiplier pulses has been designed, and successfully realized. The temporal shape of photomultiplier pulse and the upstream Read Out system for preshower are described in this document

  6. Charge reconstruction in large-area photomultipliers

    Science.gov (United States)

    Grassi, M.; Montuschi, M.; Baldoncini, M.; Mantovani, F.; Ricci, B.; Andronico, G.; Antonelli, V.; Bellato, M.; Bernieri, E.; Brigatti, A.; Brugnera, R.; Budano, A.; Buscemi, M.; Bussino, S.; Caruso, R.; Chiesa, D.; Corti, D.; Dal Corso, F.; Ding, X. F.; Dusini, S.; Fabbri, A.; Fiorentini, G.; Ford, R.; Formozov, A.; Galet, G.; Garfagnini, A.; Giammarchi, M.; Giaz, A.; Insolia, A.; Isocrate, R.; Lippi, I.; Longhitano, F.; Lo Presti, D.; Lombardi, P.; Marini, F.; Mari, S. M.; Martellini, C.; Meroni, E.; Mezzetto, M.; Miramonti, L.; Monforte, S.; Nastasi, M.; Ortica, F.; Paoloni, A.; Parmeggiano, S.; Pedretti, D.; Pelliccia, N.; Pompilio, R.; Previtali, E.; Ranucci, G.; Re, A. C.; Romani, A.; Saggese, P.; Salamanna, G.; Sawy, F. H.; Settanta, G.; Sisti, M.; Sirignano, C.; Spinetti, M.; Stanco, L.; Strati, V.; Verde, G.; Votano, L.

    2018-02-01

    Large-area PhotoMultiplier Tubes (PMT) allow to efficiently instrument Liquid Scintillator (LS) neutrino detectors, where large target masses are pivotal to compensate for neutrinos' extremely elusive nature. Depending on the detector light yield, several scintillation photons stemming from the same neutrino interaction are likely to hit a single PMT in a few tens/hundreds of nanoseconds, resulting in several photoelectrons (PEs) to pile-up at the PMT anode. In such scenario, the signal generated by each PE is entangled to the others, and an accurate PMT charge reconstruction becomes challenging. This manuscript describes an experimental method able to address the PMT charge reconstruction in the case of large PE pile-up, providing an unbiased charge estimator at the permille level up to 15 detected PEs. The method is based on a signal filtering technique (Wiener filter) which suppresses the noise due to both PMT and readout electronics, and on a Fourier-based deconvolution able to minimize the influence of signal distortions—such as an overshoot. The analysis of simulated PMT waveforms shows that the slope of a linear regression modeling the relation between reconstructed and true charge values improves from 0.769 ± 0.001 (without deconvolution) to 0.989 ± 0.001 (with deconvolution), where unitary slope implies perfect reconstruction. A C++ implementation of the charge reconstruction algorithm is available online at [1].

  7. Single-tube library preparation for degraded DNA

    DEFF Research Database (Denmark)

    Carøe, Christian; Gopalakrishnan, Shyam; Vinner, Lasse

    2018-01-01

    of chemically damaged and highly fragmented DNA molecules. In particular, the enzymatic reactions and DNA purification steps during library preparation can result in DNA template loss and sequencing biases, affecting downstream analyses. The development of library preparation methods that circumvent...... these obstacles and enable higher throughput are therefore of interest to researchers working with degraded DNA. 2.In this study, we compare four Illumina library preparation protocols, including two “single-tube” methods developed for this study with the explicit aim of improving data quality and reducing...... preparation time and expenses. The methods are tested on grey wolf (Canis lupus) museum specimens. 3.We found single-tube protocols increase library complexity, yield more reads that map uniquely to the reference genome, reduce processing time, and may decrease laboratory costs by 90%. 4.Given the advantages...

  8. Photomultiplier pulse Read Out system for the preshower detector of the LHCb experiment

    CERN Document Server

    Ajaltouni, Ziad J; Cornat, R; Deschamps, O; Lecoq, J; Monteil, S; Perret, P

    2003-01-01

    The second generation experiment for CP violation studies in B decays, LHCb, is a 20-m-long single-arm spectrometer to be installed on the future Large Hadron Collider at CERN. For its precision measurement purpose, it combines precise vertex location and particle identification, in addition to a performance trigger system able to cope with high flux. The first level of trigger is mainly based on the fast response of the calorimetric subsystem. Of major importance is the 6000 channels preshower detector that aims to validate the electromagnetic nature of calorimetric showers. It consists of two- radiation-length lead sheet in front of a scintillator plane. Scintillator signals are extracted from plastic cells using wavelength-shifting fibres coupled to multi-anode photomultiplier tubes. The preshower Read Out system has to cope with fluctuating photomultiplier pulses caused by small amounts of photoelectrons, in addition to strong constraints imposed by the 40 MHz LHC bunch- crossing frequency. A special Read...

  9. A new VME-based high voltage power supply for large photomultiplier systems

    International Nuclear Information System (INIS)

    Neumaier, S.; Hubbeling, T.; Kolb, B.W.; Purschke, M.L.; Ippolitov, M.; Blume, C.; Bohne, E.M.; Bucher, D.; Claussen, A.; Peitzmann, T.; Schepers, G.; Schlagheck, H.

    1995-01-01

    We describe a new high voltage power supply, developed for the leadglass calorimeter of the WA98 experiment at CERN. The high voltage is produced for each of the 10,080 photomultiplier tubes of the detector individually, by the same number of active bases with on-board Greinacher voltage multipliers. The full VME-based HV controller system, which addresses each base via bus cables once per second, is miniaturized and fits into a single VME crate. The main advantages of this approach are the low heat dissipation, the considerably reduced amount of cabling and cost, as well as the high stability and low noise of the system. (orig.)

  10. Brachytherapy dosimeter with silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Moutinho, L.M., E-mail: moutinho@ua.pt [i3N, Physics Department, University of Aveiro (Portugal); Castro, I.F.C. [i3N, Physics Department, University of Aveiro (Portugal); Peralta, L. [Faculdade de Ciências da Universidade de Lisboa (Portugal); Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Lisboa (Portugal); Abreu, M.C. [Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Lisboa (Portugal); Veloso, J.F.C.A. [i3N, Physics Department, University of Aveiro (Portugal)

    2015-07-01

    In-vivo and in-situ measurement of the radiation dose administered during brachytherapy faces several technical challenges, requiring a very compact, tissue-equivalent, linear and highly sensitive dosimeter, particularly in low-dose rate brachytherapy procedures, which use radioactive seeds with low energy and low dose deposition rate. In this work we present a scintillating optical fiber dosimeter composed of a flexible sensitive probe and a dedicated electronic readout system based on silicon photomultiplier photodetection, capable of operating both in pulse and current modes. The performance of the scintillating fiber optic dosimeter was evaluated in low energy regimes, using an X-ray tube operating at voltages of 40–50 kV and currents below 1 mA, to assess minimum dose response of the scintillating fiber. The dosimeter shows a linear response with dose and is capable of detecting mGy dose variations like an ionization chamber. Besides fulfilling all the requirements for a dosimeter in brachytherapy, the high sensitivity of this device makes it a suitable candidate for application in low-dose rate brachytherapy. According to Peralta and Rego [1], the BCF-10 and BCF-60 scintillating optical fibers used in dosimetry exhibit high variations in their sensitivity for photon beams in the 25–100 kVp energy range. Energy linearity for energies below 50 keV needs to be further investigated, using monochromatic X-ray photons.

  11. Time resolution performance studies of contemporary high speed photomultipliers

    International Nuclear Information System (INIS)

    Leskovar, B.; Lo, C.C.

    1977-01-01

    The time resolution capabilities of prototype microchannel plate and static crossed-field photomultipliers have been investigated. Measurements were made of electron transit time, rise time, time response, single photoelectron time spread and multiphotoelectron time spread for LEP HR350 proximity focused high gain curved microchannel plate and VPM-154A/1.6L static crossed-field photomultipliers. The experimental data have been compared with results obtained with conventionally designed RCS 8850 and C31024 high speed photomultipliers. Descriptions are given of both the measuring techniques and the measuring systems

  12. GEM photomultiplier operation in CF sub 4

    CERN Document Server

    Breskin, Amos; Chechik, R

    2002-01-01

    The properties of a 3-GEM (Gas Electron Multiplier) element photomultiplier, with a semitransparent CsI photocathode and CF sub 4 gas filling, are presented. Compared to other gas mixtures, such as CH sub 4 , Ar/CH sub 4 , Ar/N sub 2 and He/Ar/N sub 2 , CF sub 4 has superior performance: the highest gain, approaching 10 sup 7 , the fastest, 8 ns wide signal and the lowest photoelectron backscattering; the latter allows to reach photocathode quantum efficiency values approaching that in vacuum. The time resolution of the multi-GEM photomultiplier for single photoelectrons was measured to be 2 ns. These properties are of high relevance for applications in Cherenkov detectors and in tracking devices.

  13. Simulation of Silicon Photomultiplier Signals

    Science.gov (United States)

    Seifert, Stefan; van Dam, Herman T.; Huizenga, Jan; Vinke, Ruud; Dendooven, Peter; Lohner, Herbert; Schaart, Dennis R.

    2009-12-01

    In a silicon photomultiplier (SiPM), also referred to as multi-pixel photon counter (MPPC), many Geiger-mode avalanche photodiodes (GM-APDs) are connected in parallel so as to combine the photon counting capabilities of each of these so-called microcells into a proportional light sensor. The discharge of a single microcell is relatively well understood and electronic models exist to simulate this process. In this paper we introduce an extended model that is able to simulate the simultaneous discharge of multiple cells. This model is used to predict the SiPM signal in response to fast light pulses as a function of the number of fired cells, taking into account the influence of the input impedance of the SiPM preamplifier. The model predicts that the electronic signal is not proportional to the number of fired cells if the preamplifier input impedance is not zero. This effect becomes more important for SiPMs with lower parasitic capacitance (which otherwise is a favorable property). The model is validated by comparing its predictions to experimental data obtained with two different SiPMs (Hamamatsu S10362-11-25u and Hamamatsu S10362-33-25c) illuminated with ps laser pulses. The experimental results are in good agreement with the model predictions.

  14. Single-frequency reflection characterisation of shock tube excited plasma

    Directory of Open Access Journals (Sweden)

    Jing Tian

    2017-08-01

    Full Text Available Plasma has been of great interest to engineers and scientists during the past few decades due to its wide applications. Besides, the plasma-sheath-caused lose of communication (i.e. re-entry blackout that happens when a spacecraft re-enters the earth atmosphere is still a problem to be solved. The microwave characterisation of shock tube excited plasma has been an important method for exploring the transmission and reflection of microwave signals in plasma. The existing frequency sweep or multi-frequency technologies are not desirable for the characterisation of high-speed time-varying plasma generated in shock tubes. Hence, in this paper a novel signal-frequency approach is proposed to measure both electron density and collision frequency of plasma in shock tube. As frequency sweep is not required in this method, it is extremely suitable for characterising the shock tube excited high-speed time-varying plasma. The genetic algorithm is applied to extract electron density and collision frequency from the reflection coefficient. Simulation results demonstrate excellent accuracy for electron density within 1 0 10 ∼ 1 0 12   c m − 3 and collision frequency within 5 × 1 0 10 ∼ 1 0 12   H z . This work paves the way for a fast and compact microwave reflection measurement of shock tube generated plasma.

  15. Strength and Stability Analysis of a Single Walled Black Phosphorus Tube under Axial Compression

    OpenAIRE

    Cai, Kun; Wan, Jing; Wei, Ning; Qin, Qinghua

    2016-01-01

    Few-layered black phosphorus materials recently attract much attention due to its special electronic properties. As a Consequence, the nano-tube from a single-layer black phosphorus has been theoretically built. The corresponding electronic properties of such black phosphorus nano-tube were also evaluated numerically.

  16. Development of a Modern Cosmic Ray Telescope based on Silicon Photomultipliers for use in High Schools

    Science.gov (United States)

    Ruiz Castruita, Daniel; Niduaza, Rommel; Hernandez, Victor; Knox, Adrian; Ramos, Daniel; Fan, Sewan; Fatuzzo, Laura

    2015-04-01

    Lately, a new light sensor technology based on the breakdown phenomenon in the reverse biased silicon diode has found many applications that span from particle physics to medical imaging science. The silicon photomultiplier (SiPM) has several notable advantages compared to conventional photomultiplier tubes which include: lower cost, lower operating voltage and the ability to measure very weak light signals at the single photon level. At this conference meeting, we describe our efforts to implement SiPMs as read out light detectors for plastic scintillators in a cosmic ray telescope for use in high schools. In particular, we describe our work in designing, testing and assembling the cosmic ray telescope. We include a high gain preamplifier, a custom coincidence circuit using fast comparators to discriminate the SiPM signal amplitudes and a monovibrator IC for lengthening the singles and coincidence logic pulses. An Arduino micro-controller and program sketches are used for processing and storing the singles and coincidence counts data. Results from our measurements would be illustrated and presented. US Department of Education Title V Grant Award PO31S090007.

  17. Position-sensitive gaseous photomultipliers research and applications

    CERN Document Server

    Francke, Tom; Peskov, Vladimir

    2016-01-01

    Gaseous photomultipliers are defined as gas-filled devices capable of recording single ultraviolet (UV) and visible photons with high position resolution. Used in a variety of research areas, these detectors can be paired with computers to treat and store imaging information of UV-light. Position-Sensitive Gaseous Photomultipliers: Research and Applications explores the advancement of gaseous detectors as applied for single photon detection. Emphasizing emerging perspectives and new ways to apply gaseous detectors across research fields, this research-based publication is an essential reference source for engineers, physicists, graduate-level students, and researchers.

  18. An amplifier for VUV photomultiplier operating in cryogenic environment

    Energy Technology Data Exchange (ETDEWEB)

    Arneodo, F.; Benabderrahmane, M.L.; Dahal, S. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Di Giovanni, A., E-mail: adriano.digiovanni@nyu.edu [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); D' Inzeo, M.; Franchi, G. [Age Scientific srl – Capezzano Pianore (Italy); Pazos Clemens, L. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates)

    2016-07-11

    We present the characterisation of an amplifier potentially interesting for noble liquid detectors. The design has been conceived considering the requirements of low power consumption (less than 30 mW), low noise, amplification factor of 10 at 100 MHz and use of commercial components. The amplifier has been integrated onto an electronic board with a voltage divider to operate an Hamamatsu R11410 photomultiplier tube (used in XENON1T, Aprile et al. (2014) [1] dark matter experiment).

  19. Batch production of microchannel plate photo-multipliers

    Energy Technology Data Exchange (ETDEWEB)

    Frisch, Henry J.; Wetstein, Matthew; Elagin, Andrey

    2018-03-06

    In-situ methods for the batch fabrication of flat-panel micro-channel plate (MCP) photomultiplier tube (PMT) detectors (MCP-PMTs), without transporting either the window or the detector assembly inside a vacuum vessel are provided. The method allows for the synthesis of a reflection-mode photocathode on the entrance to the pores of a first MCP or the synthesis of a transmission-mode photocathode on the vacuum side of a photodetector entrance window.

  20. Development of a scintillating optical fiber dosimeter with silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Moutinho, L.M., E-mail: moutinho@ua.pt [I3N, Physics Department, University of Aveiro (Portugal); Castro, I.F. [I3N, Physics Department, University of Aveiro (Portugal); Peralta, L. [Faculdade de Ciências da Universidade de Lisboa (Portugal); Laboratório de Instrumentação e Física Experimental de Partículas, LIP-Lisboa (Portugal); Abreu, M.C. [Laboratório de Instrumentação e Física Experimental de Partículas, LIP-Lisboa (Portugal); Veloso, J.F.C.A. [I3N, Physics Department, University of Aveiro (Portugal)

    2014-01-21

    A radiation dosimeter for low dose rates based on a scintillating optical fiber coupled to a high gain photon-counting silicon photomultiplier (SiPM) for light readout was developed. The dosimeter satisfies most of the requirements for in-vivo, low dose-rate and real-time dosimetry. The device uses a small scintillator, is flexible and reasonably water-equivalent for photon energies above 100 keV [1,2]. Promising results were obtained when operating the device in current mode, detecting radiation from an X-ray tube in the 15–40 kV range and for anode currents as low as a few μA. As single-photon detectors, the major drawback of SiPMs is their high dark count rate (noise), which is a problem for low dose rate measurements in single photon counting mode. This drawback can be reduced by cooling the SiPMs or by using a much more efficient proposed solution in which two SiPMs operate in coincidence mode reading out the same optical fiber, thus allowing the rejection of false events triggered by dark noise. We have implemented a simple low-cost system, with dedicated front-end electronics operating in pulse mode for coincidence detection. Performance studies of the dosimeter operating in current mode, as a function of the X-ray tube current and voltage, show good sensitivity even for low radiation dose. When operating in pulse mode under low activity gamma irradiation, the coincidence system was able to reduce the dark noise to a residual value. -- Highlights: • Development of a plastic scintillation detector for low dose and low energy dosimetry. • Possibility of SiPMs as photosensor for a real-time dosimetry. • Operation in coincidence mode minimizes the effect of dark noise of the SiPM.

  1. Theoretical Investigation on the Solubilization in Water of Functionalized Single-Wall Carbon Nano tubes

    International Nuclear Information System (INIS)

    Mananghaya, M.; Rodulfo, E.; Santos, G.N.; Villagracia, A.; Mananghaya, M.

    2012-01-01

    An important technique to increase the solubility and reactivity of carbon nano tube is through functionalization. In this study, the effects of functionalization of some single-walled carbon nano tubes (SWCNTs) were investigated with the aid of density functional theory. The SWCNT model used in the study consists of a finite, (5, 0) zigzag nano tube segment containing 60 C atoms with hydrogen atoms added to the dangling bonds of the perimeter carbons. There are three water-dispersible SWCNTs used in this study that were functionalized with (a) formic acid, as a model of carboxylic acid, (b) isophthalic acid, as a model aromatic dicarboxylic acid, and (c) benzenesulfonic acid, as a model aromatic sulfonic acid. Binding energies of the organic radicals to the nano tubes are calculated, as well as the HOMO-LUMO gaps and dipole moments of both nano tubes and functionalized nano tubes. Binding was found out to be thermodynamically favorable. The functionalization increases the electrical dipole moments and results in an enhancement in the solubility of the nano tubes in water manifested through favorable changes in the free energies of solvation. This should lower the toxicity of nano tubes and improve their biocompatibility.

  2. Small angle neutron scattering study of isolated single wall carbon nano tubes in water

    International Nuclear Information System (INIS)

    Doe, Chang-Woo; Kim, Tae-Hwan; Choi, Sung-Min; Kline, Steven R.

    2007-01-01

    As an effort to provide more practical approaches to a wide range of potential applications of carbon nano tubes, we report a new type of noncovalently functionalized isolated single-walled carbon nano tube(SWNT) which is easily dispersible in water by only ten minutes of mild vortex mixing. The structure and quality of dispersion have been investigated using small angle neutron scattering (SANS) technique

  3. Hydrogen storage in single-wall carbon nano-tubes by means of laser excitation

    International Nuclear Information System (INIS)

    Oksengorn, B.

    2010-01-01

    A new mode for hydrogen adsorption and storage in single-wall carbon nano-tubes is used, on the basis of laser excitation. Remember that this method has been useful to obtain, in the case of the fullerene C 60 , many complex C 60 -atoms or C 60 -molecules, where atoms or molecular particles are trapped inside the C 60 -molecules. We think this method might be important to store many hydrogen molecules inside carbon nano-tubes. (author)

  4. Silicon Photomultipliers (SiPM) as novel photodetectors for PET

    International Nuclear Information System (INIS)

    Del Guerra, Alberto; Belcari, Nicola; Giuseppina Bisogni, Maria; Corsi, Francesco; Foresta, Maurizio; Guerra, Pedro; Marcatili, Sara; Santos, Andres; Sportelli, Giancarlo

    2011-01-01

    Next generation PET scanners should fulfill very high requirements in terms of spatial, energy and timing resolution. Modern scanner performances are inherently limited by the use of standard photomultiplier tubes. The use of Silicon Photomultipliers (SiPMs) is proposed for the construction of a 4D-PET module of 4.8x4.8 cm 2 aimed to replace the standard PMT based PET block detector. The module will be based on a LYSO continuous crystal read on two faces by Silicon Photomultipliers. A high granularity detection surface made by SiPM matrices of 1.5 mm pitch will be used for the x-y photon hit position determination with submillimetric accuracy, while a low granularity surface constituted by 16 mm 2 SiPM pixels will provide the fast timing information (t) that will be used to implement the Time of Flight technique (TOF). The spatial information collected by the two detector layers will be combined in order to measure the Depth of Interaction (DOI) of each event (z). The use of large area multi-pixel Silicon Photomultiplier (SiPM) detectors requires the development of a multichannel Data Acquisition system (DAQ) as well as of a dedicated front-end in order not to degrade the intrinsic detector capabilities and to manage many channels. The paper describes the progress made on the development of the proof of principle module under construction at the University of Pisa.

  5. Position Sensitive Gaseous Photomultipliers

    CERN Document Server

    Martinengo, P; Peskov, V

    2010-01-01

    Advances in the technologies associated with position sensitive gaseous detectors especially featuring CsI as reflective photoconverters will be reviewed. These photodetectors represent the most effective solution for what concerns cost and performance in the case of large area Cherenkov imaging applications in relatively low rate (or low occupancy) high energy physics and astrophysics experiments. Moreover, they are the only choice when the Cherenkov detector is embedded in a magnetic field. Recently proposed single photon MPGDs (Micropattern Gaseous Detectors) will be also discussed in view of the successful efforts so far made to extend their sensitivity to visible light. With some modifications, photosensitive gaseous detectors can also be used in the imaging of X-rays and particles.

  6. Antimicrobial Activity of Single-Walled Carbon Nano tubes Suspended in Different Surfactants

    International Nuclear Information System (INIS)

    Dong, L.; Alex Henderson, A.; Field, Ch.

    2012-01-01

    We investigated the antibacterial activity of single-walled carbon nano tubes (SWCNTs) dispersed in surfactant solutions of sodium cholate, sodium dodecylbenzene sulfonate, and sodium dodecyl sulfate. Among the three surfactants, sodium cholate demonstrated the weakest antibacterial activity against Salmonella enterica, Escherichia coli, and Enterococcus faecium and thereby was used to disperse bundled SWCNTs in order to study nano tube antibiotic activity. SWCNTs exhibited antibacterial characteristics for both S. enterica and E. coli. With the increase of nano tube concentrations from 0.3 mg/mL to 1.5 mg/mL, the growth curves had plateaus at lower absorbance values whereas the absorbance value was not obviously affected by the incubation ranging from 5?min to 2 h. Our findings indicate that carbon nano tubes could become an effective alternative to antibiotics in dealing with drug-resistant and multidrug-resistant bacterial strains because of the physical mode of bactericidal action that SWCNTs display

  7. Experimental and numerical determination of temperature gradients for a single tube alkali metal thermal-to-electric converter cell

    Science.gov (United States)

    Wright, S.

    2001-01-01

    This paper presents the results from the experimental and numerical determination of shell temperature gradients for a single tube AMTEC cell evaluated under simulated deep space operating conditions.

  8. Single-tube linear DNA amplification (LinDA) for robust ChIP-seq

    NARCIS (Netherlands)

    Shankaranarayanan, P.; Mendoza-Parra, M.A.; Walia, M.; Wang, L.; Li, N.; Trindade, L.M.; Gronemeyer, H.

    2011-01-01

    Genome-wide profiling of transcription factors based on massive parallel sequencing of immunoprecipitated chromatin (ChIP-seq) requires nanogram amounts of DNA. Here we describe a high-fidelity, single-tube linear DNA amplification method (LinDA) for ChIP-seq and reChIP-seq with picogram DNA amounts

  9. Single-sided sheet-to-tube spot welding investigated by 3D numerical simulations

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Chergui, Azeddine; Zhang, Wenqi

    The single-sided resistance spot welding process is analyzed by a 3D numerical study of sheet-to-tube joining. Finite element simulations are carried out in SORPAS® 3D. Two levels of electrode force and five levels of welding current are simulated. The overall effects of changing current and force...

  10. Pressure Drop Correlations of Single-Phase and Two-Phase Flow in Rolling Tubes

    International Nuclear Information System (INIS)

    Xia-xin Cao; Chang-qi Yan; Pu-zhen Gao; Zhong-ning Sun

    2006-01-01

    A series of experimental studies of frictional pressure drop for single phase and two-phase bubble flow in smooth rolling tubes were carried out. The tube inside diameters were 15 mm, 25 mm and 34.5 mm respectively, the rolling angles of tubes could be set as 10 deg. and 20 deg., and the rolling periods could be set as 5 s, 10 s and 15 s. Combining with the analysis of single-phase water motion, it was found that the traditional correlations for calculating single-phase frictional coefficient were not suitable for the rolling condition. Based on the experimental data, a new correlation for calculating single-phase frictional coefficient under rolling condition was presented, and the calculations not only agreed well with the experimental data, but also could display the periodically dynamic characteristics of frictional coefficients. Applying the new correlation to homogeneous flow model, two-phase frictional pressure drop of bubble flow in rolling tubes could be calculated, the results showed that the relative error between calculation and experimental data was less than ± 25%. (authors)

  11. An experimental study on single basin solar still augmented with evacuated tubes

    Directory of Open Access Journals (Sweden)

    Sampathkumar K.

    2012-01-01

    Full Text Available The productivity of the solar still is determined by the temperature of water in the basin and the glass temperature. Various active methods have been adopted to increase the temperature of the basin, so as to improve the productivity of solar still. Most of the previous research works have been focusing on flat plate collector and concentrating collector. In this experimental study, a single slope solar still directly augmented with evacuated tubes was used to increase the daily productivity by reducing heat losses. Evacuated tubes were directly coupled to the lower side of the single slope solar still with an area of 1m2. Black gravel is used to increase the productivity by means of reducing quantity of water in the basin. Extensive experiments were conducted to explore the performance of solar still in several modes namely still alone, still with black stones, still with evacuated tubes, and still with evacuated tubes and black gravel. The experimental setup was designed and installed at Solar Energy Park, Tamilnadu College of Engineering, Coimbatore (77˚E, 11˚N, Tamilnadu, India. These experiments were conducted using tap water as feed. It was found that, after augmentation of the evacuated tubes, the daily production rate has increased by 49.7 % and it increased by 59.48% with black stones. Economic analysis was also done and payback period of this experimental setup is 235 days.

  12. Investigations of single-electron avalanches in a proportional drift tube

    International Nuclear Information System (INIS)

    Anderson, W.S.; Armitage, J.C.; Chevreau, P.; Heinrich, J.G.; Lu, C.; McDonald, I.; McDonald, K.T.; Miller, B.; Secrest, D.; Weckel, J.

    1990-01-01

    Detailed information on single-electron drift and avalanche behavior has a basic interest in an investigation of gas-chamber performance. Its timing, avalanche distribution, attachment by the working gas mixtures, etc., provide various criteria for choosing the best suitable gas mixture under a specific experimental circumstance. Investigations of single-electron avalanches in a proportional drift tube have been carried out with a pulsed N 2 laser. The study consists of two aspects: timing properties, and fluctuations in the gas avalanche

  13. Tests of timing properties of silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Ronzhin, A.; Albrow, M.; /Fermilab; Byrum, K.; /Argonne; Demarteau, M.; Los, S.; /Fermilab; May, E.; /Argonne; Ramberg, A.; /Fermilab; Va' vra, J.; /SLAC; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez

    2010-03-01

    Timing measurements of Silicon Photomultipliers (SiPM) [1] and [2] at the picosecond level were performed at Fermilab. The core timing resolution of the electronic measurement technique is approximately 2 ps. The single photoelectron time resolution (SPTR) was measured for the signals coming from the SiPM's. A SPTR of about one hundred picoseconds was obtained for SiPM's illuminated by laser pulses. The dependence of the SPTR on applied bias voltage and on the wavelength of the light was measured. A simple model is proposed to explain the difference in the SPTR for blue and red light. A time of flight system based on the SiPM's, with quartz Cherenkov radiators, was tested in a proton beam at Fermilab. The time resolution obtained is 35 ps per SiPM. Finally, requirements for the SiPM's temperature and bias voltage stability to maintain the time resolution are discussed.

  14. LYSO crystal calorimeter readout with silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Berra, A., E-mail: alessandro.berra@gmail.com [Università degli Studi dell' Insubria (Italy); INFN sezione di Milano Bicocca (Italy); Bonvicini, V. [INFN sezione di Trieste (Italy); Cecchi, C.; Germani, S. [INFN sezione di Perugia (Italy); Guffanti, D. [Università degli Studi dell' Insubria (Italy); Lietti, D. [Università degli Studi dell' Insubria (Italy); INFN sezione di Milano Bicocca (Italy); Lubrano, P.; Manoni, E. [INFN sezione di Perugia (Italy); Prest, M. [Università degli Studi dell' Insubria (Italy); INFN sezione di Milano Bicocca (Italy); Rossi, A. [INFN sezione di Perugia (Italy); Vallazza, E. [INFN sezione di Trieste (Italy)

    2014-11-01

    Large area Silicon PhotoMultipliers (SiPMs) are the new frontier of the development of readout systems for scintillating detectors. A SiPM consists of a matrix of parallel-connected silicon micropixels operating in limited Geiger–Muller avalanche mode, and thus working as independent photon counters with a very high gain (∼10{sup 6}). This contribution presents the performance in terms of linearity and energy resolution of an electromagnetic homogeneous calorimeter composed of 9∼18X{sub 0} LYSO crystals. The crystals were readout by 36 4×4 mm{sup 2} SiPMs (4 for each crystal) produced by FBK-irst. This calorimeter was tested at the Beam Test Facility at the INFN laboratories in Frascati with a single- and multi-particle electron beam in the 100–500 MeV energy range.

  15. Single port laparoscopic long-term tube gastrostomy in Göttingen minipigs

    DEFF Research Database (Denmark)

    Birck, Malene Muusfeldt; Vegge, Andreas; Moesgaard, S G

    2015-01-01

    Oral dosing by gavage is often used to test compounds in minipigs. This method is also used for certain nutritional studies that require exact dosing. This procedure may be stressful for the animal and requires the assistance of more than one technician. We investigated whether a gastrostomy tube...... it was evident that the catheter had entered the stomach in the fundus region in 11/12 of the animals. In one animal the catheter had entered the antrum region. None of the animals developed leakage or clinically detectable reactions to the gastrostomy tube. Histopathologically, only discrete changes were...... observed. Single port laparoscopic tube gastrostomy with a locking pigtail catheter is safe, simple and reliable and is an appropriate alternative to, for example, percutaneous endoscopic gastrostomy, when long-term enteral delivery of pharmacological or nutritional compounds is needed. The use...

  16. Single-crystal sapphire tubes as economical probes for optical pyrometry in harsh environments.

    Science.gov (United States)

    Růžička, Jakub; Houžvička, Jindřich; Bok, Jiří; Praus, Petr; Mojzeš, Peter

    2011-12-20

    One-end-sealed single-crystal sapphire tubes are presented as a simple, robust, and economical alternative for bulky lightpipe probes. Thermal radiation from a blackbody cavity created at the inner surface of the sealed end is gathered by a simple lens-based collecting system and transmitted via optical fiber to the remote detection unit. Simplicity and applicability of the concept are demonstrated by the combination of commercially available sapphire tubes with a common optical pyrometer. Radiation thermometers with sapphire tubes as invasive probes can be useful for applications requiring immunity to electromagnetic interference, resistance to harsh environments, simple replacement in the case of failure, and enhanced mechanical firmness, enabling wider range probe positioning inside the medium of interest.

  17. Numeric Simulation of Heat Transfer from a Single Round Tube Shielded with Wire Mesh

    Directory of Open Access Journals (Sweden)

    Dymo B.V.

    2015-08-01

    Full Text Available This paper presents the results of development and investigation of heat transfer at transverse flow of round tube with wire screen using the software ANSYS Fluent 3D-model. Selection of optimal parameters of the finite element model, in particular, transition shear stress transport model as well and boundary conditions are realized. Instructed and combined net is used at numerical calculations. This net is built with the help of generators grid-torus ANSYS CFX Mesh 14.0. The problem of verification of conformity of the numerical model of the heat transfer of a single screen-covered round tubes according to physical experiment for the same tubes in the range of Reynolds numbers Re = (5000...35000 was studied. We established that discrepancy between physical experiments and numerical simulation results not exceeds 5% with respect to the data of physical experiment.

  18. Experimental study of single taylor bubbles rising in stagnant liquid mixtures inside of vertical tubes

    International Nuclear Information System (INIS)

    Azevedo, Marcos B. de; Faccini, Jose L.H.; Su, Jian

    2015-01-01

    The present work reports an experimental study of single Taylor bubbles rising in vertical tubes filled with water-glycerin mixtures by using the pulse-echo ultrasonic technique. A 2m long acrylic tube with inner diameter of 24 mm was used in the experiments. Initially, the tube was sealed at the ends and filled partially with the liquid mixtures to leave an air pocket of length L 0 at the top end. A Taylor bubble was formed by the inversion of the tube. The rising bubbles were detected by ultrasonic transducers located at the upper part of the tube. The velocity, the length and the pro le of the bubbles and the thickness of the liquid lm around them were obtained from the ultrasonic signals processing. The liquid lm thickness in the vertical tube was also determined by a graphic method that relates the bubble length L b with the initial length of the air pocket L 0 . It was observed that the bubble velocity decreased with increasing viscosity, while the lm thickness increased. It was shown that the liquid lm thickness determined by the graphic method fitted well the higher viscosities data, but overestimated the lower viscosities data. Additionally, the results indicated that some correlations developed to estimate the thickness of liquid films falling down inside/outside of tubes and down a plane surface could be applied to estimate the thickness of liquid films falling around Taylor bubbles in an Inverse Viscosity Number (N f ) range different to those considered in the literature. (author)

  19. Silicon photomultipliers and their bio-medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Eugene [Institute for Theoretical and Experimental Physics (ITEP), B.Cheremushkinskaya 25, Moscow 117218 (Russian Federation) and Forimtech S.A., Route de Malagnou 32, Geneva 1208 (Switzerland)]. E-mail: grigoriev@forimtech.ch; Akindinov, Alexander [Institute for Theoretical and Experimental Physics (ITEP), B.Cheremushkinskaya 25, Moscow 117218 (Russian Federation); Breitenmoser, Marco [Forimtech S.A., Route de Malagnou 32, Geneva 1208 (Switzerland); Buono, Stefano [Advanced Accelerator Applications S.A (AAA), 20 rue Diesel, 01630 St. Genis Pouilly (France); Charbon, Edoardo [Ecole Politechnique Federale de Lausanne (EPFL), AQUA Group, Lausanne 1015 (Switzerland); Niclass, Cristiano [Ecole Politechnique Federale de Lausanne (EPFL), AQUA Group, Lausanne 1015 (Switzerland); Desforges, Iris [Forimtech S.A., Route de Malagnou 32, Geneva 1208 (Switzerland); Rocca, Roberto [Advanced Accelerator Applications S.A (AAA), 20 rue Diesel, 01630 St. Genis Pouilly (France)

    2007-02-01

    Single Photon Avalanche Diodes (SPADs) have been used for photon counting since the 1960s, but only in the recent decade multi-pixel structures based on SPAD-arrays and silicon photomultipliers have been developed. These devices are finding more and more applications in many fields, where detection of light at the level of a single photon is needed. Due to their exclusive properties (fast response, low operating voltage, single photon sensitivity at room temperature, extremely high gain, stability, compactness, robustness and low price), such sensors are successfully replacing traditional vacuum photomultipliers in many devices. The paper briefly describes the state of the art and suggests some new applications in biology and medicine.

  20. Investigating the temperature dependence of photomultiplier quantum efficiency when operating in the visible spectrum

    CERN Document Server

    Clawson, Savannah Ellen

    2017-01-01

    The quantum efficiency of a Burle 8850 photomultiplier tube with a potassium-caesium-antimony (bialkali) photocathode was determined by attenuating a 1 mW HeNe laser emitting at 633 nm and measuring the signal frequency when the laser was incident on the photomultiplier. A temperature range of 5 $^{\\circ}$C $-$ 20 $^{\\circ}$C was investigated and it was found that the quantum efficiency decreases with temperature, with the signal frequency decreasing at a faster rate than the dark current frequency. Therefore, it was concluded that it would not be beneficial to cool photomultiplier tubes operating in the visible spectrum for use in collinear laser spectroscopy due to a decreasing signal-to-noise ratio. The signal pulse height distribution was also analysed and found to be independent of temperature within the range investigated.

  1. Silicon photomultipliers in AMIGA muon counters

    Energy Technology Data Exchange (ETDEWEB)

    Botti, Ana Martina [Institut fuer Kernphysik, Karlsruher Institut fuer Technologie (Germany); Instituto de Tecnologias en Deteccion y Astroparticulas (ITeDA) (Argentina); Collaboration: Pierre-Auger-Collaboration

    2016-07-01

    The project AMIGA (Auger Muons and Infill for the Ground Array) aims to extend the energy range at the Pierre Auger Observatory to observe cosmic rays of lower energies (down to ∝10{sup 17} eV) and to study the transition from extragalactic to galactic cosmic rays. AMIGA is compounded by an infill of surface detectors (employing Cherenkov radiation detection in water) and muon counters. The AMIGA muon counters consist of an array of buried modules composed of 64 scintillator bars, a multi-pixel Photo Multiplier Tube (PMT) and the corresponding electronic of acquisition which works along with the surface detector. Currently, ITeDA is evaluating the feasibility of replacing PMTs with silicon photomultipliers (SiPM) without performing any substantial modification in the digital readout nor in the mechanical design. I present calibration results of a prototype module associated to the surface detector Toune of the Pierre Auger Observatory using a SiPM Hamamatsu S1257-100C plugged to the standard AMIGA front-end electronics. In addition, a study concerning gain stability and temperature variation has also been performed and is reported. I finally discuss a comparison between traces measured by both photodetectors (PMT and SiPM) for modules associated to the surface detector Toune.

  2. Procedures and results of the measurements on large area photomultipliers for the NEMO project

    Science.gov (United States)

    Aiello, S.; Leonora, E.; Aloisio, A.; Ameli, F.; Amore, I.; Anghinolfi, M.; Anzalone, A.; Barbarino, G.; Barbarito, E.; Battaglieri, M.; Bazzotti, M.; Bellotti, R.; Bersani, A.; Beverini, N.; Biagi, S.; Bonori, M.; Bouhdaef, B.; Cacopardo, G.; Calı, C.; Capone, A.; Caponetto, L.; Carminati, G.; Cassano, B.; Ceres, A.; Chiarusi, T.; Circella, M.; Cocimano, R.; Coniglione, R.; Cordelli, M.; Costa, M.; D'Amico, A.; DeBonis, G.; DeRosa, G.; DeRuvo, G.; DeVita, R.; Distefano, C.; Flaminio, V.; Fratini, K.; Gabrielli, A.; Galeotti, S.; Gandolfi, E.; Giacomelli, G.; Giorgi, F.; Giovanetti, G.; Grimaldi, A.; Grmek, A.; Habel, R.; Imbesi, M.; Lonardo, A.; LoPresti, D.; Lucarelli, F.; Margiotta, A.; Marinelli, A.; Martini, A.; Masullo, R.; Maugeri, F.; Migneco, E.; Minutoli, S.; Mongelli, M.; Morganti, M.; Musico, P.; Musumeci, M.; Orlando, A.; Osipenko, M.; Papaleo, R.; Pappalardo, V.; Piattelli, P.; Piombo, D.; 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.; Shirokov, E.; Simeone, F.; Sciliberto, D.; Sipala, V.; Sollima, C.; Spurio, M.; Stefani, F.; Taiuti, M.; Terreni, G.; Trasatti, L.; Urso, S.; Vecchi, M.; Vicini, P.; Wischnewski, R.

    2010-03-01

    The selection of the photomultiplier plays a crucial role in the R&D activity related to a large-scale underwater neutrino telescope. This paper illustrates the main procedures and facilities used to characterize the performances of 72 large area photomultipliers, Hamamatsu model R7081 sel. The voltage to achieve a gain of 5×10 7, dark count rate and single photoelectron time and charge properties of the overall response were measured with a properly attenuated 410 nm pulsed laser. A dedicated study of the spurious pulses was also performed. The results prove that the photomultipliers comply with the general requirements imposed by the project.

  3. Silicon Photomultipliers for Compact Neutron Scatter Cameras

    Science.gov (United States)

    Ruch, Marc L.

    The ability to locate and identify special nuclear material (SNM) is critical for treaty verification and emergency response applications. SNM is used as the nuclear explosive in a nuclear weapon. This material emits neutrons, either spontaneously or when interrogated. The ability to form an image of the neutron source can be used for characterization and/or to confirm that the item is a weapon by determining whether its shape is consistent with that of a weapon. Additionally, treaty verification and emergency response applications might not be conducive to non-portable instruments. In future weapons treaties, for example, it is unlikely that host countries will make great efforts to facilitate large, bulky, and/or fragile inspection equipment. Furthermore, inspectors and especially emergency responders may need to access locations not easily approachable by vehicles. Therefore, there is a considerable need for a compact, human-portable neutron imaging system. Of the currently available neutron imaging technologies, only neutron scatter cameras (NSCs) can be made truly compact because aperture-based imagers, and time-encoded imagers, rely on large amounts of materials to modulate the neutron signal. NSCs, in contrast, can be made very small because most of the volume of the imager can be filled with active detector material. Also, unlike other neutron imaging technologies, NSCs have the inherent ability to act as neutron spectrometers which gives them an additional means of identifying a neutron source. Until recently, NSCs have relied on photomultiplier tubes (PMT) readouts, which are bulky and fragile, require high voltage, and are very sensitive to magnetic fields. Silicon photomultipliers (SiPMs) do not suffer from these drawbacks and are comparable to PMTs in many respects such as gain, and cost with better time resolution. Historically, SiPMs have been too noisy for these applications; however, recent advancements have greatly reduced this issue and they have

  4. Silicon photomultiplier timing performance study

    Science.gov (United States)

    Gamal, Ahmed; Paul, Bühler; Johann, Marton; Ken, Suzuki

    2011-10-01

    Many characteristics of Silicon Photomultipliers can be tuned with temperature and operation voltage. We present preliminary results of a study of the effect of these two operation parameters on the time resolution of large active area Multi-Pixel Photon Counters (MPPCs) manufactured by Hamamatsu. Measurements at -10, 0, and 10 °C at different bias voltages were performed. The time resolution is best at low temperature and high over-voltage. Most significant improvements can be achieved in cases with low number of fired pixels (40 pixels) the effect of temperature and operation voltage becomes smaller. The timing performance still improves with decreasing temperature ( ≈factor of 2) but it hardly depends on the operation voltage. The study shows that especially in applications where only few photons are available for detection a careful optimization of temperature and operation voltage are advisable to obtain optimum timing results with the MPPC.

  5. Evaluation of single and double centrifugation tube methods for concentrating equine platelets.

    Science.gov (United States)

    Argüelles, D; Carmona, J U; Pastor, J; Iborra, A; Viñals, L; Martínez, P; Bach, E; Prades, M

    2006-10-01

    The aim of this study was to evaluate single and double centrifugation tube methods for concentrating equine platelets. Whole blood samples were collected from clinically normal horses and processed by use of single and double centrifugation tube methods to obtain four platelet concentrates (PCs): PC-A, PC-B, PC-C, and PC-D, which were analyzed using a flow cytometry hematology system for hemogram and additional platelet parameters (mean platelet volume, platelet distribution width, mean platelet component concentration, mean platelet component distribution width). Concentrations of transforming growth factor beta 1 (TGF-beta(1)) were determined in all the samples. Platelet concentrations for PC-A, PC-B, PC-C, and PC-D were 45%, 44%, 71%, and 21% higher, respectively, compared to the same values for citrated whole blood samples. TGF-beta(1) concentrations for PC-A, PC-B, PC-C, and PC-D were 38%, 44%, 44%, and 37% higher, respectively, compared to citrated whole blood sample values. In conclusion, the single and double centrifugation tube methods are reliable methods for concentrating equine platelets and for obtaining potentially therapeutic TGF-beta(1) levels.

  6. The Megapixel EBCCD a high-resolution imaging tube sensitive to single photons

    CERN Document Server

    Buontempo, S; Dalinenko, I N; Ereditato, A; Ekimov, A V; Fabre, Jean-Paul; Fedorov, V Yu; Frenkel, A; Galeazzi, F; Garufi, F; Golovkin, S V; Govorun, V N; Kalashnikova, N N; Kosov, V G; Kozarenko, E N; Kreslo, I E; Lasovsky, L Y; Liberti, B; Malyarov, A V; Martellotti, G; Medvedkov, A M; Penso, G; Vishnevski, G I; Wolff, T; Zhuk, A

    1998-01-01

    A hybrid image-intensifier tube, suitable for extremely low-light imaging, has been tested. This device is based on an Electron-Bombarded CCD chip (EBCCD) with $1024 \\times 1024$ sensitive pixe ls. The tube, which has a photocathode diameter of 40 mm, is gateable and zoomable, with an image magnification varying from 0.62 to 1.3. The high gain (about 4000 collected electrons per photo electron at the operational voltage of 15 kV) and the relatively low noise (180 electrons per pixel at 10 MHz pixel-readout frequency), allows single-photoelectron signals to be separated from n oise with a signal-to-noise ratio greater than 10. By applying an appropriate threshold on the signal amplitude, the background can almost be eliminated, with a loss of few percent in single-ph otoelectron counting. High inner gain, low noise, single-photoelectron sensitivity, and high spatial resolution make the EBCCD imaging tube a unique device, attractive for many applications in h igh-energy physics, astrophysics, biomedical diagnos...

  7. An Educational Kit Based On a Modular Silicon Photomultiplier System

    International Nuclear Information System (INIS)

    Caccia, Massimo; Chmill, Valery; Ebolese, Amedeo; Martemyanov, Alexander; Risigo, Fabio; Santoro, Romualdo; Locatelli, Marco; Pieracci, Maura; Tintori, Carlo

    2013-06-01

    Silicon Photo-Multipliers (SiPM) are state of the art light detectors with unprecedented single photon sensitivity and photon number resolving capability, representing a breakthrough in several fundamental and applied Science domains. An educational experiment based on a SiPM set-up is proposed in this article, guiding the student towards a comprehensive knowledge of this sensor technology while experiencing the quantum nature of light and exploring the statistical properties of the light pulses emitted by a LED. (authors)

  8. High resolution scintillation hodoscope using a position sensitive photomultiplier

    International Nuclear Information System (INIS)

    Ditta, J.; Sillou, D.; Michalowicz, A.; Azaiez, H.; Kuroda, K.

    1983-09-01

    Using a position sensitive photomultiplier we have realized and tested a prototype of high resolution scintillation hodoscope. A space resolution of approximately 1 mm (FWHM) has been obtained by a single block of NE102A scintillator, 10 mm thick, with 10 GeV/c π - particles. An off-line analysis based on the moment method has confirmed the fact that suitable cuts in the second-order moments provides a powerful criterion for improving the image quality

  9. YouTube and the single-rod contraceptive implant: a content analysis.

    Science.gov (United States)

    Paul, Jennifer; Boraas, Christy M; Duvet, Mildred; Chang, Judy C

    2017-07-01

    Since the internet has become an important source of contraceptive information with YouTube.com as the second most visited site, we analysed contraceptive implant YouTube videos for content and clinical accuracy. Using the terms 'contraceptive implant', 'Nexplanon' and 'Implanon', the top 20 results on YouTube by relevance and view count were identified. After excluding duplicates, single-rod implant videos in English were included. Videos were classified as providing a professional or patient perspective. Views, duration and comments were noted. Videos were rated for reliability, global quality scale and whether they were positive or negative about the implant. Inter-rater agreement was measured. A total of 120 videos were retrieved; 52 were eligible for review. Less than 23% were professional videos; the majority reported patient experience (46% testimonials, 27% real-time procedure videos, 4% other). Patient videos had been posted a significantly longer duration of time than professional videos (364 vs 188 days, p =0.02), were less reliable ( p ≤0.0001) and were of lower global quality ( p YouTube pertaining to contraceptive implants is accurate, is presented from the patient's perspective, and promotes the method's use. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  10. A single-tube approach for in vitro diagnostics using diatomaceous earth and optical sensor.

    Science.gov (United States)

    Zhao, Fei; Koo, Bonhan; Liu, Huifang; Eun Jin, Choong; Shin, Yong

    2018-01-15

    Versatile, simple and efficient sample preparation is desirable for point-of-care testing of emerging diseases such as zoonoses, but current sample preparation assays are insensitive, labour-intensive and time-consuming and require multiple instruments. We developed a single-tube sample preparation approach involving direct pathogen enrichment and extraction from human specimens using diatomaceous earth (DE). Amine-modified DE was used to directly enrich a zoonotic pathogen, Brucella, in a large sample volume. Next, a complex of amine-modified DE and dimethyl suberimidate was used for nucleic acid extraction from the enriched pathogen. Using our single-tube approach, the pathogen can be enriched and extracted within 60min at a level of 1 colony formation unit (CFU) from a 1ml sample volume in the same tube. The performance of this approach is 10-100 times better than that of a commercial kit (10 2 to 10 3 CFU/ml) but does not require a large centrifuge. Finally, we combined the single-tube approach with a bio-optical sensor for rapid and accurate zoonotic pathogen detection in human urine samples. Using the combination system, Brucella in human urine can be efficiently enriched (~ 8-fold) and the detection limit is enhanced by up to 100 times (1CFU/ml bacteria in urine) compared with the commercial kit. This combined system is fast and highly sensitive and thus represents a promising approach for disease diagnosis in the clinical setting. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. High efficiency 40 K single-stage Stirling-type pulse tube cryocooler

    Science.gov (United States)

    Wu, X. L.; Chen, L. B.; Pan, C. Z.; Cui, C.; Wang, J. J.; Zhou, Y.

    2017-12-01

    A high efficiency single-stage Stirling-type coaxial pulse tube cryocooler (SPTC) operating at around 40 K has been designed, built and tested. The double-inlet and the inertance tubes together with the gas reservoir were adopted as the phase shifters. Under the conditions of 2.5 MPa charging pressure and 30 Hz operating frequency, the prototype has achieved a no-load temperature of 23.8 K with 330 W of electric input power at a rejection temperature of 279 K. When the input power increases to 400 W, it can achieve a cooling capacity of 4.7 W/40 K while rejecting heat at 279 K yielding an efficiency of 7.02% relative to Carnot. It achieves a cooling capacity of 5 W/40 K with an input power of 450 W. It takes 10 minutes for the SPTC to cool to its no-load temperature of 40 K from 295 K.

  12. Modeling crosstalk in silicon photomultipliers

    International Nuclear Information System (INIS)

    Gallego, L; Rosado, J; Blanco, F; Arqueros, F

    2013-01-01

    Optical crosstalk seriously limits the photon-counting resolution of silicon photomultipliers. In this work, realistic analytical models to describe the crosstalk effects on the response of these photodetectors are presented and compared with experimental data. The proposed models are based on the hypothesis that each pixel of the array has a finite number of available neighboring pixels to excite via crosstalk. Dead-time effects and geometrical aspects of the propagation of crosstalk between neighbors are taken into account in the models for different neighborhood configurations. Simple expressions to account for crosstalk effects on the pulse-height spectrum as well as to evaluate the excess noise factor due to crosstalk are also given. Dedicated measurements were carried out under both dark-count conditions and pulsed illumination. Moreover, the influence of afterpulsing on the measured pulse-height spectrum was studied, and a measurement of the recovery time of pixels was reported. High-resolution pulse-height spectra were obtained by means of a detailed waveform analysis, and the results have been used to validate our crosstalk models.

  13. Silicon photomultiplier timing performance study

    Energy Technology Data Exchange (ETDEWEB)

    Gamal, Ahmed, E-mail: gamal.ahmed@assoc.oeaw.ac.at [Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, Vienna (Austria); Al-Azhar University, Faculty of Science, Physics Department, Cairo (Egypt); Paul, Buehler; Johann, Marton; Ken, Suzuki [Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, Vienna (Austria)

    2011-10-01

    Many characteristics of Silicon Photomultipliers can be tuned with temperature and operation voltage. We present preliminary results of a study of the effect of these two operation parameters on the time resolution of large active area Multi-Pixel Photon Counters (MPPCs) manufactured by Hamamatsu. Measurements at -10, 0, and 10 deg. C at different bias voltages were performed. The time resolution is best at low temperature and high over-voltage. Most significant improvements can be achieved in cases with low number of fired pixels (<10pixels). Between the worst and best case among the considered conditions a factor of five improvement was observed. In cases with large number of fired pixels (>40pixels) the effect of temperature and operation voltage becomes smaller. The timing performance still improves with decreasing temperature ({approx}factor of 2) but it hardly depends on the operation voltage. The study shows that especially in applications where only few photons are available for detection a careful optimization of temperature and operation voltage are advisable to obtain optimum timing results with the MPPC.

  14. A Robust Single Primate Neuroepithelial Cell Clonal Expansion System for Neural Tube Development and Disease Studies

    Directory of Open Access Journals (Sweden)

    Xiaoqing Zhu

    2016-02-01

    Full Text Available Developing a model of primate neural tube (NT development is important to promote many NT disorder studies in model organisms. Here, we report a robust and stable system to allow for clonal expansion of single monkey neuroepithelial stem cells (NESCs to develop into miniature NT-like structures. Single NESCs can produce functional neurons in vitro, survive, and extensively regenerate neuron axons in monkey brain. NT formation and NESC maintenance depend on high metabolism activity and Wnt signaling. NESCs are regionally restricted to a telencephalic fate. Moreover, single NESCs can turn into radial glial progenitors (RGPCs. The transition is accurately regulated by Wnt signaling through regulation of Notch signaling and adhesion molecules. Finally, using the “NESC-TO-NTs” system, we model the functions of folic acid (FA on NT closure and demonstrate that FA can regulate multiple mechanisms to prevent NT defects. Our system is ideal for studying NT development and diseases.

  15. Single-tube nested PCR for detection of tritrichomonas foetus in feline feces.

    Science.gov (United States)

    Gookin, Jody L; Birkenheuer, Adam J; Breitschwerdt, Edward B; Levy, Michael G

    2002-11-01

    Tritrichomonas foetus, a venereal pathogen of cattle, was recently identified as an inhabitant of the large intestine in young domestic cats with chronic diarrhea. Recognition of the infection in cats has been mired by unfamiliarity with T. foetus in cats as well as misdiagnosis of the organisms as Pentatrichomonas hominis or Giardia sp. when visualized by light microscopy. The diagnosis of T. foetus presently depends on the demonstration of live organisms by direct microscopic examination of fresh feces or by fecal culturing. As T. foetus organisms are fastidious and fragile, routine flotation techniques and delayed examination and refrigeration of feces are anticipated to preclude the diagnosis in numerous cases. The objective of this study was to develop a sensitive and specific PCR test for the diagnosis of feline T. foetus infection. A single-tube nested PCR was designed and optimized for the detection of T. foetus in feline feces by using a combination of novel (TFITS-F and TFITS-R) and previously described (TFR3 and TFR4) primers. The PCR is based on the amplification of a conserved portion of the T. foetus internal transcribed spacer (ITS) region (ITS1 and ITS2) and the 5.8S rRNA gene. The absolute detection limit of the single-tube nested PCR was 1 organism, while the practical detection limit was 10 organisms per 200 mg of feces. Specificity was examined by using P. hominis, Giardia lamblia, and feline genomic DNA. Our results demonstrate that the single-tube nested PCR is ideally suited for (i) diagnostic testing of feline fecal samples that are found negative by direct microscopy and culturing and (ii) definitive identification of microscopically observable or cultivated organisms.

  16. Single-tube linear DNA amplification (LinDA) for robust ChIP-seq.

    Science.gov (United States)

    Shankaranarayanan, Pattabhiraman; Mendoza-Parra, Marco-Antonio; Walia, Mannu; Wang, Li; Li, Ning; Trindade, Luisa M; Gronemeyer, Hinrich

    2011-06-05

    Genome-wide profiling of transcription factors based on massive parallel sequencing of immunoprecipitated chromatin (ChIP-seq) requires nanogram amounts of DNA. Here we describe a high-fidelity, single-tube linear DNA amplification method (LinDA) for ChIP-seq and reChIP-seq with picogram DNA amounts obtained from a few thousand cells. This amplification technology will facilitate global analyses of transcription-factor binding and chromatin with very small cell populations, such as stem or cancer-initiating cells.

  17. Large-area CMOS solid-state photomultipliers and recent developments

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Erik B., E-mail: ejohnson@rmdinc.com [Radiation Monitoring Devices, Inc., 44 Hunt Street, Watertown, MA 02472 (United States); Stapels, Christopher J.; Xiao Jiechen [Radiation Monitoring Devices, Inc., 44 Hunt Street, Watertown, MA 02472 (United States); Augustine, Frank L. [Augustine Engineering, 2115 Park Dale Lane, Encinitas, CA 92024 (United States); Christian, James F. [Radiation Monitoring Devices, Inc., 44 Hunt Street, Watertown, MA 02472 (United States)

    2011-10-01

    The CMOS solid-state photomultiplier (SSPM) is an array of Geiger avalanche photodiodes (GPD) read out in parallel. These devices are not susceptible to magnetic fields, less expensive to fabricate than many other photodetector technologies, compact, and allow for on-chip integration of signal processing circuits. A number of nuclear detection applications require detector sizes on the order of 1 cm. Standard silicon fabrication technology limits the size of the SSPM die, and tiling of the silicon die can result in large-area devices but results in dead space between die for bonding purposes. Radiation Monitoring Devices (RMD) has fabricated 1x1 cm SSPM arrays on a single die. The size of these devices is large enough to provide an alternative detector for scintillation detector applications compared to photomultiplier tubes. Although the size increases the dark noise, we will demonstrate that the large-area SSPM can provide a PMT-like response for {sup 22}Na gamma rays using an LYSO crystal. Each of the noise terms associated with the large-area SSPM is discussed, quantifying the cross talk and after pulse multipliers, which are scaling factors to the gain to account for the additional output charge from the SSPM. The excess noise factor associated with cross talk and after pulsing has a linear dependence on the multiplier term. The signal and noise terms have been compiled to provide the best operating voltage of roughly 6 V above breakdown for a 1x1 cm CMOS SSPM to be operated with a short integration time (<10 ns) and at 0 deg. C.

  18. Experimental research on single-phase heat transfer characteristics in a vertical circular tube under marine conditions

    International Nuclear Information System (INIS)

    Du Sijia; Zhang Hong; Jia Baoshan

    2011-01-01

    Experiments have been conducted to study the heat transfer characteristics of single-phase forced circulation when the test tube was under different marine conditions. The experiments measured the wall temperature of test tube to calculate the heat transfer coefficients at different circumferential places. When the test tube was under inclined conditions, the heat transfer coefficient increased at downside and decreased at upside of test tube because of buoyancy effect. When the test tube was under rolling conditions, the heat transfer coefficients fluctuated with the rolling motions, and the Coriolis force dominated the heat transfer fluctuation during the rolling motion. CFD method was used to simulate the heat transfer phenomena under marine conditions, and the results were accord to the experimental phenomena. (authors)

  19. Accuracy of Motor Axon Regeneration Across Autograft, Single Lumen, and Multichannel Poly(lactic-co-glycolic Acid) (PLGA) Nerve Tubes

    Science.gov (United States)

    de Ruiter, Godard C.; Spinner, Robert J.; Malessy, Martijn J. A.; Moore, Michael J.; Sorenson, Eric J.; Currier, Bradford L.; Yaszemski, Michael J.; Windebank, Anthony J.

    2012-01-01

    Objective Accuracy of motor axon regeneration becomes an important issue in the development of a nerve tube for motor nerve repair. Dispersion of regeneration across the nerve tube may lead to misdirection and polyinnervation. In this study, we present a series of methods to investigate the accuracy of regeneration, which we used to compare regeneration across autografts and single lumen poly(lactic-co-glycolic acid) (PLGA) nerve tubes. We also present the concept of the multichannel nerve tube that may limit dispersion by separately guiding groups of regenerating axons. Methods Simultaneous tracing of the tibial and peroneal nerves with fast blue (FB) and diamidino yellow (DY), 8 weeks after repair of a 1-cm nerve gap in the rat sciatic nerve, was performed to determine the percentage of double-projecting motoneurons. Sequential tracing of the peroneal nerve with DY 1 week before and FB 8 weeks after repair was performed to determine the percentage of correctly directed peroneal motoneurons. Results In the cases in which there was successful regeneration across single lumen nerve tubes, more motoneurons had double projections to both the tibial and peroneal nerve branches after single lumen nerve tube repair (21.4%) than after autograft repair (5.9%). After multichannel nerve tube repair, this percentage was slightly reduced (16.9%), although not significantly. The direction of regeneration was nonspecific after all types of repair. Conclusion Retrograde tracing techniques provide new insights into the process of regeneration across nerve tubes. The methods and data presented in this study can be used as a basis in the development of a nerve tube for motor nerve repair. PMID:18728579

  20. Single cells for forensic DNA analysis--from evidence material to test tube.

    Science.gov (United States)

    Brück, Simon; Evers, Heidrun; Heidorn, Frank; Müller, Ute; Kilper, Roland; Verhoff, Marcel A

    2011-01-01

    The purpose of this project was to develop a method that, while providing morphological quality control, allows single cells to be obtained from the surfaces of various evidence materials and be made available for DNA analysis in cases where only small amounts of cell material are present or where only mixed traces are found. With the SteREO Lumar.V12 stereomicroscope and UV unit from Zeiss, it was possible to detect and assess single epithelial cells on the surfaces of various objects (e.g., glass, plastic, metal). A digitally operated micromanipulator developed by aura optik was used to lift a single cell from the surface of evidence material and to transfer it to a conventional PCR tube or to an AmpliGrid(®) from Advalytix. The actual lifting of the cells was performed with microglobes that acted as carriers. The microglobes were held with microtweezers and were transferred to the DNA analysis receptacles along with the adhering cells. In a next step, the PCR can be carried out in this receptacle without removing the microglobe. Our method allows a single cell to be isolated directly from evidence material and be made available for forensic DNA analysis. © 2010 American Academy of Forensic Sciences.

  1. Towards Optical Partial Discharge Detection with Micro Silicon Photomultipliers

    Science.gov (United States)

    Ren, Ming; Song, Bo; Dong, Ming

    2017-01-01

    Optical detection is reliable in intrinsically characterizing partial discharges (PDs). Because of the great volume and high-level power supply of the optical devices that can satisfy the requirements in photosensitivity, optical PD detection can merely be used in laboratory studies. To promote the practical application of the optical approach in an actual power apparatus, a silicon photomultiplier (SiPM)-based PD sensor is introduced in this paper, and its basic properties, which include the sensitivity, pulse resolution, correlation with PD severity, and electromagnetic (EM) interference immunity, are experimentally evaluated. The stochastic phase-resolved PD pattern (PRPD) for three typical insulation defects are obtained by SiPM PD detector and are compared with those obtained using a high-frequency current transformer (HFCT) and a vacuum photomultiplier tube (PMT). Because of its good performances in the above aspects and its additional advantages, such as the small size, low power supply, and low cost, SiPM offers great potential in practical optical PD monitoring. PMID:29125544

  2. Integrated Planar Solid Oxide Fuel Cell: Steady-State Model of a Bundle and Validation through Single Tube Experimental Data

    Directory of Open Access Journals (Sweden)

    Paola Costamagna

    2015-11-01

    Full Text Available This work focuses on a steady-state model developed for an integrated planar solid oxide fuel cell (IP-SOFC bundle. In this geometry, several single IP-SOFCs are deposited on a tube and electrically connected in series through interconnections. Then, several tubes are coupled to one another to form a full-sized bundle. A previously-developed and validated electrochemical model is the basis for the development of the tube model, taking into account in detail the presence of active cells, interconnections and dead areas. Mass and energy balance equations are written for the IP-SOFC tube, in the classical form adopted for chemical reactors. Based on the single tube model, a bundle model is developed. Model validation is presented based on single tube current-voltage (I-V experimental data obtained in a wide range of experimental conditions, i.e., at different temperatures and for different H2/CO/CO2/CH4/H2O/N2 mixtures as the fuel feedstock. The error of the simulation results versus I-V experimental data is less than 1% in most cases, and it grows to a value of 8% only in one case, which is discussed in detail. Finally, we report model predictions of the current density distribution and temperature distribution in a bundle, the latter being a key aspect in view of the mechanical integrity of the IP-SOFC structure.

  3. A deep-sea agglutinated foraminifer tube constructed with planktonic foraminifer shells of a single species

    Science.gov (United States)

    Pearson, Paul N.; Expedition 363 Shipboard Scientific Party, IODP

    2018-01-01

    Agglutinated foraminifera are marine protists that show apparently complex behaviour in constructing their shells, involving selecting suitable sedimentary grains from their environment, manipulating them in three dimensions, and cementing them precisely into position. Here we illustrate a striking and previously undescribed example of complex organisation in fragments of a tube-like foraminifer (questionably assigned to Rhabdammina) from 1466 m water depth on the northwest Australian margin. The tube is constructed from well-cemented siliciclastic grains which form a matrix into which hundreds of planktonic foraminifer shells are regularly spaced in apparently helical bands. These shells are of a single species, Turborotalita clarkei, which has been selected to the exclusion of all other bioclasts. The majority of shells are set horizontally in the matrix with the umbilical side upward. This mode of construction, as is the case with other agglutinated tests, seems to require either an extraordinarily selective trial-and-error process at the site of cementation or an active sensory and decision-making system within the cell.

  4. UNCONTROLLED PHOTOMULTIPLIER CURRENT IN PHOTOEMISSION ANALYSIS

    Directory of Open Access Journals (Sweden)

    K. A. Viazava

    2016-01-01

    Full Text Available The dependence of photon energy from energy of photoelectron is base of photoemission radiation analysis. In such photoemission measurements except current of photocathode is always exist a reverse current from the collector of electrons to the photocathode in two-electrode sensors. There are various ways of reverse and uncontrolled current eliminating or reducing their influence. The constructive method is based on creating an electron-optical system of photoelectronic device, which would be a photoelectron energy analyzer. The second method – technological. However, it requires the manufacture of the photocathode and the dynode system in different vacuum chamber with subsequent connection to a single device in vacuum environment without exposure to the atmosphere. The purpose of this article is to determinate the effect of photoemission from photocathode chamber and the first dynode of photomultiplier on energy distribution of the photoelectrons from photocathode. To solve this problem authors obtained calibration curves for measuring pyrometer module ПИФ 4/2 with ФЭУ-114 as a sensor at supply voltage 1350 V and different decelerating voltages. The effect of illumination on the value of modulation coefficient on temperature k(T and wavelength k(λ is shown. In temperature measurements, this effect is evident in fact that at temperatures below 1400 K linear dependence ln k – T-1 is broken. Still this linear dependence is a necessary consequence of the fact that the measured temperature is color temperature. However, this calibration curve can be used to measure low temperature if the target measurements condition and calibration conditions are identical. In wavelength calibration, curve k(λ at λ > 760 nm is two-valued, that doesn’t allow to identify monochromatic radiation by this method and bring in errors in temperature measurements. 

  5. New device and method for capture, reverse transcription and nested PCR in a single closed-tube.

    Science.gov (United States)

    Olmos, A; Cambra, M; Esteban, O; Gorris, M T; Terrada, E

    1999-01-01

    A device and improved method based on the use of a compartmentalized Eppendorf tube that allows capture, reverse transcription and nested-PCR in a single closed-tube has been developed and patented. The main advantages of the system are the high sensitivity obtained, the simplicity, the low risk of contamination and the easy establishment of adequate conditions for nested-PCR. The method has been successfully applied to the detection and characterization of citrus tristeza closterovirus and plum pox potyvirus isolates in plant tissues and single aphids squashed on paper. This device and methodology could be easily adapted to the detection of other targets. PMID:10037824

  6. Single-stage micro-scale solvent extraction in parallel microbore tubes using MDIMJ

    International Nuclear Information System (INIS)

    Darekar, Mayur; Singh, K.K.; Joshi, J.M.; Mukhopadhyay, S.; Shenoy, K.T.

    2016-01-01

    Single-stage micro-scale solvent extraction of U(VI) from simulated lean streams is explored using micro-scale contactor comprising of a MDIMJ (Monoblock Distributor with Integrated Microfluidic Junction) and PTFE microbore tubes. 30% (v/v) TBP in dodecane has been used as the extracting phase. The objective of the study is to demonstrate numbering up approach for scale-up of micro-scale extraction using indigenously conceptualized and fabricated MDIMJ. First the performance of MIDIMJ for equal flow distribution is tested. Then the effects of inlet flow rate and O/A ratio on stage efficiency and percentage extraction are studied. The experiments show that it is easy to scale-up single-stage micro-scale solvent extraction by using MDIMJ for numbering up approach. Maximum capacity tested is 4.8 LPH. With O/A = 2/1, more than 90% extraction is achieved in a very short contact time of less than 3s. The study thus demonstrates possibility of process intensification and easy scale-up of micro-scale solvent extraction

  7. Single-tube hydroponics as a novel idea for small-scale production of crop seed in a plant incubator.

    Science.gov (United States)

    Kuroda, Masaharu; Ikenaga, Sachiko

    2015-01-01

    We present a novel protocol for small-scale production of crop seed in a plant incubator termed "Single-tube hydroponics." Our protocol minimizes the materials and methods for cultivation whereby a large number of independent plants can be cultured in a limited space. This study may aid in the improvement of crop seed components, especially in the cultivation of transgenic plants.

  8. Copper hexacyanoferrate functionalized single-walled carbon nano-tubes for selective cesium extraction

    International Nuclear Information System (INIS)

    Draouil, H.; Alvarez, L.; Bantignies, J.L.; Causse, J.; Cambedouzou, J.; Flaud, V.; Zaibi, M.A.; Oueslati, M.

    2017-01-01

    Single-walled carbon nano-tubes (SWCNTs) are functionalized with copper hexacyanoferrate (CuHCF) nanoparticles to prepare solid substrates for sorption of cesium ions (Cs + ) from liquid outflows. The high mechanical resistance and large electrical conductivity of SWCNTs are associated with the ability of CuHCF nanoparticles to selectively complex Cs + ions in order to achieve membrane-like buckypapers presenting high loading capacity of cesium. The materials are thoroughly characterized using electron microscopy, Raman scattering, X-ray photoelectron spectroscopy and thermogravimetric analyses. Cs sorption isotherms are plotted after having measured the Cs + concentration by liquid phase ionic chromatography in the solution before and after exposure to the materials. It is found that the total sorption capacity of the material reaches 230 mg.g -1 , and that about one third of the sorbed Cs (80 mg.g -1 ) is selectively complexed in the CuHCF nanoparticles grafted on SWCNTs. The quantification of Cs + ions on different sorption sites is made for the first time, and the high sorption rates open interesting outlooks in the integration of such materials in devices for the controlled sorption and desorption of these ions. (authors)

  9. Void fraction and pressure drop measurement in a reflooded single tube

    International Nuclear Information System (INIS)

    Deruaz, R.; Freitas, R.L.

    1983-01-01

    Void fraction is a key parameter both to interpret emergency cooling experiments and to predict the clad temperature transient during a loss of coolant accident of PWR. However classical techniques to measure void fraction ask some problems, expecially in the case of large breaks for which both flooding rate and pressure are low and characterized by a wide range of void fraction associated with different two-phase flow regimes. A series of axial void fraction and pressure profiles was performed, respectively on a direct heated and an indirect heated reflooded single tube which inner diameter is very close to the hydraulic diameter of a 17 x 17 PWR assembly. This paper mainly deals with the neutron scattering technique used to investigate void fraction. Various aspects are discussed, such as radial distribution effect, energy of neutrons, measurements of scattered or transmitted neutron flux, counting technique, water temperature and axial void gradient effects. Typical results are presented as well as a comparison between experimental data and predictions of various void fraction models

  10. Enhancement of PCR Detection Limit by Single-Tube Restriction Endonuclease-PCR (RE-PCR).

    Science.gov (United States)

    Datta, Sibnarayan; Budhauliya, Raghvendra; Chatterjee, Soumya; Vanlalhmuaka; Veer, Vijay; Chakravarty, Runu

    2016-06-01

    Polymerase chain reaction (PCR) is widely used in biological research and diagnostics because of its high sensitivity and specificity. However, the sensitivity of PCR is strongly influenced by topological characteristics of the template. Supercoiled templates are known to inhibit PCR, whereas linearized forms of the same supercoiled templates facilitate PCR. This study was conducted to compare the PCR efficiency of circular supercoiled DNA templates to their restriction endonuclease (RE)-mediated linearized forms. Additionally, we also evaluated the possibility of RE digestion of the circular supercoiled templates within the complete PCR buffer. Following a systematic approach, we demonstrated that circular supercoiled templates could be efficiently linearized by RE in the complete PCR buffer itself. This allowed linearization of circular supercoiled templates and their subsequent amplification in the PCR buffer in a single-tube format. Using this extremely simple RE-PCR approach, we documented up to tenfold increases in detection efficiency of PCR with two different circular supercoiled templates of clinical origin, including an international calibration standard. This inexpensive and easy approach to increasing PCR sensitivity can be easily adapted to any standard PCR protocol aimed at amplifying circular supercoiled genomes. Apart from its application in the development of sensitive clinical diagnostic PCR assays for a large number of organisms, this method could also prove to be very useful in simplifying the existing protocols for other applications where pre-PCR restriction digestion is required, such as mutation detection, genotyping, and selective template amplification.

  11. Single-Tube Flow Cytometry Assay for the Detection of Mature Lymphoid Neoplasms in Paucicellular Samples.

    Science.gov (United States)

    Stacchini, Alessandra; Demurtas, Anna; Aliberti, Sabrina; Barreca, Antonella; Novero, Domenico; Pacchioni, Donatella

    2016-01-01

    Flow cytometry (FC) has become a useful support for cytomorphologic evaluation (CM) of fine-needle aspirates (FNA) and serous cavity effusions (SCE) in cases of suspected non-Hodgkin lymphoma (NHL). FC results may be hampered by the scarce viability and low cellularity of the specimens. We developed a single-tube FC assay (STA) that included 10 antibodies cocktailed in 8-color labeling, a cell viability dye, and a logical gating strategy to detect NHL in hypocellular samples. The results were correlated with CM and confirmed by histologic or molecular data when available. Using the STA, we detected B-type NHL in 31 out of 103 hypocellular samples (81 FNA and 22 SCE). Of these, 8 were not confirmed by CM and 2 were considered to be only suspicious. The FC-negative samples had a final diagnosis of benign/reactive process (42/72), carcinoma (27/72), or Hodgkin lymphoma (3/72). The STA approach allowed obtainment of maximum immunophenotyping data in specimens containing a low number of cells and a large amount of debris. The information obtained by STA can help cytomorphologists not only to recognize but also to exclude malignant lymphomas. © 2016 S. Karger AG, Basel.

  12. Isolation of Microarray-Grade Total RNA, MicroRNA, and DNA from a Single PAXgene Blood RNA Tube

    DEFF Research Database (Denmark)

    Kruhøffer, Mogens; Andersen, Lars Dyrskjøt; Voss, Thorsten

    2007-01-01

    We have developed a procedure for isolation of microRNA and genomic DNA in addition to total RNA from whole blood stabilized in PAXgene Blood RNA tubes. The procedure is based on automatic extraction on a BioRobot MDx and includes isolation of DNA from a fraction of the stabilized blood......RNA was tested using spotted locked nucleic acid-based microarrays. We conclude that the yield and quality of total RNA, microRNA, and DNA from a single PAXgene blood RNA tube is sufficient for downstream microarray analysis....

  13. Single-Phase Crossflow Mixing in a Vertical Tube Bundle Geometry : An Experimental Study

    NARCIS (Netherlands)

    Mahmood, A.

    2011-01-01

    The vertical rod/tube bundle geometry has a wide variety of industrial applications. Typical examples are the core of light water nuclear reactors (LWR) and vertical tube steam generators. In the core of a LWR, primarily coolant flows upward but their also exist a flow in lateral direction, called

  14. Precision analysis of the photomultiplier response to ultra low signals

    Science.gov (United States)

    Degtiarenko, Pavel

    2017-11-01

    A new computational model for the description of the photon detector response functions measured in conditions of low light is presented, together with examples of the observed photomultiplier signal amplitude distributions, successfully described using the parameterized model equation. In extension to the previously known approximations, the new model describes the underlying discrete statistical behavior of the photoelectron cascade multiplication processes in photon detectors with complex non-uniform gain structure of the first dynode. Important features of the model include the ability to represent the true single-photoelectron spectra from different photomultipliers with a variety of parameterized shapes, reflecting the variability in the design and in the individual parameters of the detectors. The new software tool is available for evaluation of the detectors' performance, response, and efficiency parameters that may be used in various applications including the ultra low background experiments such as the searches for Dark Matter and rare decays, underground neutrino studies, optimizing operations of the Cherenkov light detectors, help in the detector selection procedures, and in the experiment simulations.

  15. Fast light pulse measurements and temporal fluctuations in photomultipliers

    International Nuclear Information System (INIS)

    Miehe, J.A.; Sipp, B.

    1975-01-01

    This paper reviews the results on time fluctuations in high gain first dynode photomultipliers used in single photon timing experiments; the theoretical analysis of the measurement of the shape of light pulses is recalled and the previously obtained results concerning time dispersion in the photocathode, first dynode space are discussed. In addition, the influence of the variations of the electron transit time in the multiplier on the time resolution curves of the detector is examined: the curves obtained by leading-edge triggering of the anodic pulse show a strong dependence on the threshold level of the discriminator. A single-photoelectron timing resolution of 270ps is measured using a low leading edge discrimination [fr

  16. Stability and lifetime testing of photomultiplier detectors for the Earth observing system SOLSTICE program

    Science.gov (United States)

    Hadler, Joshua A.; van de Kop, Toni; Drake, Virginia A.; McClintock, William E.; Murphy, John; Rodgers, Paul

    1998-10-01

    The primary objective of the Earth Observing System (EOS) Solar Stellar Irradiance Comparison Experiment (SOLSTICE) is to accurately measure the absolute value of the solar UV irradiance at the top of the earth's atmosphere for a minimum mission lifetime of 5 years. To meet this objective, SOLSTICE employs a unique design to determine changes in instrument performance by routinely observing a series of early-type stars and comparing the irradiances directly with the solar value. Although the comparison techniques allows us to track instrument performance, the success of the SOLSTICE experiment depends upon photomultiplier detectors which have graceful degradation properties. Therefore, we have established a laboratory program to evaluate the characteristics of photomultiplier tubes which are exposed to long term fluxes similar to those we expected to encounter in flight. Three types of Hamamatsu photomultiplier tubes were tested as candidates for use in the EOS-SOLSTICE project. The results of these studies: pulse height distribution; quantum efficiency; surface maps,; and lifetime analysis are presented in this paper.

  17. Reaction-time-resolved measurements of laser-induced fluorescence in a shock tube with a single laser pulse

    Science.gov (United States)

    Zabeti, S.; Fikri, M.; Schulz, C.

    2017-11-01

    Shock tubes allow for the study of ultra-fast gas-phase reactions on the microsecond time scale. Because the repetition rate of the experiments is low, it is crucial to gain as much information as possible from each individual measurement. While reaction-time-resolved species concentration and temperature measurements with fast absorption methods are established, conventional laser-induced fluorescence (LIF) measurements with pulsed lasers provide data only at a single reaction time. Therefore, fluorescence methods have rarely been used in shock-tube diagnostics. In this paper, a novel experimental concept is presented that allows reaction-time-resolved LIF measurements with one single laser pulse using a test section that is equipped with several optical ports. After the passage of the shock wave, the reactive mixture is excited along the center of the tube with a 266-nm laser beam directed through a window in the end wall of the shock tube. The emitted LIF signal is collected through elongated sidewall windows and focused onto the entrance slit of an imaging spectrometer coupled to an intensified CCD camera. The one-dimensional spatial resolution of the measurement translates into a reaction-time-resolved measurement while the species information can be gained from the spectral axis of the detected two-dimensional image. Anisole pyrolysis was selected as the benchmark reaction to demonstrate the new apparatus.

  18. An asymmetric PCR-based, reliable and rapid single-tube native DNA engineering strategy

    Science.gov (United States)

    2012-01-01

    Background Widely used restriction-dependent cloning methods are labour-intensive and time-consuming, while several types of ligase-independent cloning approaches have inherent limitations. A rapid and reliable method of cloning native DNA sequences into desired plasmids are highly desired. Results This paper introduces ABI-REC, a novel strategy combining asymmetric bridge PCR with intramolecular homologous recombination in bacteria for native DNA cloning. ABI-REC was developed to precisely clone inserts into defined location in a directional manner within recipient plasmids. It featured an asymmetric 3-primer PCR performed in a single tube that could robustly amplify a chimeric insert-plasmid DNA sequence with homologous arms at both ends. Intramolecular homologous recombination occurred to the chimera when it was transformed into E.coli and produced the desired recombinant plasmids with high efficiency and fidelity. It is rapid, and does not involve any operational nucleotides. We proved the reliability of ABI-REC using a double-resistance reporter assay, and investigated the effects of homology and insert length upon its efficiency. We found that 15 bp homology was sufficient to initiate recombination, while 25 bp homology had the highest cloning efficiency. Inserts up to 4 kb in size could be cloned by this method. The utility and advantages of ABI-REC were demonstrated through a series of pig myostatin (MSTN) promoter and terminator reporter plasmids, whose transcriptional activity was assessed in mammalian cells. We finally used ABI-REC to construct a pig MSTN promoter-terminator cassette reporter and showed that it could work coordinately to express EGFP. Conclusions ABI-REC has the following advantages: (i) rapid and highly efficient; (ii) native DNA cloning without introduction of extra bases; (iii) restriction-free; (iv) easy positioning of directional and site-specific recombination owing to formulated primer design. ABI-REC is a novel approach to

  19. An asymmetric PCR-based, reliable and rapid single-tube native DNA engineering strategy

    Directory of Open Access Journals (Sweden)

    Bi Yanzhen

    2012-07-01

    Full Text Available Abstract Background Widely used restriction-dependent cloning methods are labour-intensive and time-consuming, while several types of ligase-independent cloning approaches have inherent limitations. A rapid and reliable method of cloning native DNA sequences into desired plasmids are highly desired. Results This paper introduces ABI-REC, a novel strategy combining asymmetric bridge PCR with intramolecular homologous recombination in bacteria for native DNA cloning. ABI-REC was developed to precisely clone inserts into defined location in a directional manner within recipient plasmids. It featured an asymmetric 3-primer PCR performed in a single tube that could robustly amplify a chimeric insert-plasmid DNA sequence with homologous arms at both ends. Intramolecular homologous recombination occurred to the chimera when it was transformed into E.coli and produced the desired recombinant plasmids with high efficiency and fidelity. It is rapid, and does not involve any operational nucleotides. We proved the reliability of ABI-REC using a double-resistance reporter assay, and investigated the effects of homology and insert length upon its efficiency. We found that 15 bp homology was sufficient to initiate recombination, while 25 bp homology had the highest cloning efficiency. Inserts up to 4 kb in size could be cloned by this method. The utility and advantages of ABI-REC were demonstrated through a series of pig myostatin (MSTN promoter and terminator reporter plasmids, whose transcriptional activity was assessed in mammalian cells. We finally used ABI-REC to construct a pig MSTN promoter-terminator cassette reporter and showed that it could work coordinately to express EGFP. Conclusions ABI-REC has the following advantages: (i rapid and highly efficient; (ii native DNA cloning without introduction of extra bases; (iii restriction-free; (iv easy positioning of directional and site-specific recombination owing to formulated primer design. ABI

  20. Calculations following voltage breakdown in a single-ended Van de Graaff with an accelerator tube

    International Nuclear Information System (INIS)

    Staniforth, J.A.

    1979-01-01

    Calculation of voltages and voltage gradients in the terminal, along the insulating column and the accelerating tube are described for various breakdown positions. The method uses a number of inverted-L network sections to represent the machine assuming that the tube is coupled to the column. Various forms of coupling are examined. The calculations use an iterative computer program which calculates the voltages and currents in the networks at successive small time intervals. (author)

  1. Development of gamma spectrometer using silicon photomultiplier (SiPM)

    International Nuclear Information System (INIS)

    Kim, Chan Kyu

    2011-02-01

    Gamma spectroscopy is used to determine the identity and quantity of gamma-emitters in nuclear physics, geochemistry and astrophysics. The scintillation detectors are being used as a gamma spectrometer generally, because of their higher gamma-ray detection efficiency and cheaper price than germanium semi-conductor detectors. A typical scintillation detector is composed of a scintillator, a window, and a photodetector. The photomultiplier (PM) tube has been the most widely used as a photodetector because of its advantages like high sensitivity, high signal-to-noise ratio, and wide dynamic range. Recently, the Silicon Photomultiplier (SiPM) is being studied as a substitute of PM tube. The SiPM has almost same performance compared to PM tube but it has additional advantages; low operating voltage, small volume, and cheap production cost. In this research, the gamma spectrometer using SiPM instead of PM tube is developed. The use of SiPM as a photodetector makes the gamma spectrometer smaller, cheaper, easier to use. For photon transport and collection from the large area scintillator to the small area SiPM, a light guide is applied in this gamma spectrometer system. Before fabrication of light guide, DETECT simulation is performed to study and prospect characteristics of light guide structure. And actual light guides are fabricated on the basis of this simulation result. Poly(methyl methacrylate) (PMMA) is chosen as material of light guide, 5 sample light guides are fabricated in different lengths and coatings. As a scintillator crystal, same NaI(Tl) crystal is chosen. For measurement and analysis of gamma spectrometer system, 3 gamma spectrometer systems are composed: PM tube-based system, PM tube-based system with the light guide, SiPM-based system with the light guide. Through comparison between the results of each gamma spectrometer, the performances of gamma spectrometer system are analyzed by each component. Measurement results of the second system is well

  2. Columbia University flow instability experimental program: Volume 2. Single tube uniformly heated tests -- Part 2: Uncertainty analysis and data

    International Nuclear Information System (INIS)

    Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.

    1990-05-01

    In June 1988, Savannah River Laboratory requested that the Heat Transfer Research Facility modify the flow excursion program, which had been in progress since November 1987, to include testing of single tubes in vertical down-flow over a range of length to diameter (L/D) ratios of 100 to 500. The impetus for the request was the desire to obtain experimental data as quickly as possible for code development work. In July 1988, HTRF submitted a proposal to SRL indicating that by modifying a facility already under construction the data could be obtained within three to four months. In January 1990, HTFR issued report CU-HTRF-T4, part 1. This report contained the technical discussion of the results from the single tube uniformly heated tests. The present report is part 2 of CU-HTRF-T4 which contains further discussion of the uncertainty analysis and the complete set of data

  3. Development and evaluation of one step single tube multiplex RT-PCR for rapid detection and typing of dengue viruses

    OpenAIRE

    Parida Manmohan; Shrivastava Ambuj; Santhosh SR; Dash Paban; Saxena Parag; Rao PV

    2008-01-01

    Abstract Background Dengue is emerging as a major public health concern in many parts of the world. The development of a one-step, single tube, rapid, and multiplex reverse transcription polymerase chain reaction (M-RT-PCR) for simultaneous detection and typing of dengue virus using serotype specific primers during acute phase of illness is reported. Results An optimal assay condition with zero background was established having no cross-reaction with closely related members of flavivirus (Jap...

  4. Silicon photomultiplier arrays for the LHCb scintillating fibre tracker

    CERN Multimedia

    Girard, Olivier Goran; Kuonen, Axel Kevin; Stramaglia, Maria Elena

    2017-01-01

    For the LHCb detector upgrade in 2019, a large scale scintillating fibre tracker read out with silicon photomultipliers is under construction. The harsh radiation environment (neutron and ionising radiation), the 40MHz read-out rate of the trigger less system and the large detector surface of 320m2 impose many challenges. We present the results from lab tests with 1MeV electrons and from the SPS test facility at CERN for the mulitchannel SiPM array that combines peak photo-detection efficiency of 48% and extremely low correlated noise. The measurements were performed with detectors irradiated with neutrons up to a fluence of 12*1011 neq/cm2 and single photon detection was maintained. First results of the characterization of the pre-series of 500 detectors delivered by Hamamatsu and irradiation studies on a large sample will be included.

  5. Analysis of transit time spread on FBK silicon photomultipliers

    International Nuclear Information System (INIS)

    Acerbi, F.; Gola, A.; Ferri, A.; Zorzi, N.; Paternoster, G.; Piemonte, C.

    2015-01-01

    In this paper we studied one of the aspects potentially limiting the single-photon time-resolution (SPTR) of the silicon photomultiplier (SiPM): the transit time spread (TTS). We illuminated the SiPM in different positions with a fast-pulsed laser collimated to a circular spot of 0.2 mm-diameter and acquired bi-dimensional maps of the avalanche-signal arrival time of RGB and RGB-HD SiPMs, produced at FBK. We studied the effect of both the number of bonding wires connecting the device to the package and the layout of the top-metal connection (on the device). We found that the TTS does not simply depend on the trace length between the cell and the bonding pad and it could vary in the range between tens of picoseconds (with 3 bonding connections) to more than one hundred of picoseconds (with one connection)

  6. The Fabrication and Test of 64-Channel Silicon Photomultipliers

    Science.gov (United States)

    Lee, H. Y.; Jeon, Jin-A.; Park, Il H.; Lee, Jik

    2017-11-01

    A silicon photomultiplier (SiPM) is a highly sensitive photo sensor, and it consists of many micropixels that operated in Geiger mode. The SiPM has various preferable characteristics, such as low voltage operation compactness and lightweight. Additionally, the SiPM is robust and insensitive to magnetic fields, and it is capable of the counting of single photons due to the high gain of 105 ∼ 106. The developments of UV enhanced SiPMs and large area matrices of SiPMs have been actively pursued in the world. The technology can be utilized for applications such as radiation detection, medical science, cameras, and telescopes. In this study, we present the design, fabrication, and test result of the 64-channel SiPM sensor as the first step toward the development of a large matrix of SiPMs.

  7. Thermoregulation of silicon photomultipliers for space

    Energy Technology Data Exchange (ETDEWEB)

    Baldazzi, G.; Foschi, E. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Laurenti, G. [INFN of Bologna, Viale B.Pichat 4/2, 40127 Bologna (Italy); Levi, G. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Guandalini, C. [INFN of Bologna, Viale B.Pichat 4/2, 40127 Bologna (Italy); Lanconelli, N. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Quadrani, L. [INFN of Bologna, Viale B.Pichat 4/2, 40127 Bologna (Italy); Rossi, P. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Sbarra, C. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Enrico Fermi Research Center, Via Panisperna 89, 06100 Roma (Italy)], E-mail: cristina.sbarra@bo.infn.it; Zuffa, M. [INFN of Bologna, Viale B.Pichat 4/2, 40127 Bologna (Italy)

    2009-10-21

    The silicon photomultiplier (SiPM) has been recently studied in the INFN laboratories of Bologna for Time of Flight (TOF) detectors in space missions. Low consumption, low cost, low weight, resistance to radiation damage and insensitivity to magnetic fields are the advantages that lead to the choice of the SiPM to be used in conjunction with optical fibres for detecting the scintillation light of a space counter. The SiPM response to various light intensities has been studied in laboratory and it was compared to the PM response in order to use it for scintillation light instead of a photomultiplier. The results were confirmed by a Monte Carlo. Nevertheless the SiPM gain depends on temperature and thermal stabilization of the device turns out to be necessary. A hybrid front-end circuit that amplifies the signal while controlling and stabilizing the device temperature has been developed and some tests are shown. A thermal electric cooler (TEC) module based on Peltier cell has been modeled. The TEC module operating in atmosphere showed it can stabilize the temperature of the SiPM to the chosen set-point (9{+-}3 K) in a few seconds.

  8. Camera Embedded Single Lumen Tube as a Rescue Device for Airway Handling during Lung Separation

    DEFF Research Database (Denmark)

    Højberg Holm, Jimmy; Andersen, Claus

    2016-01-01

    endotracheal tube (SLT, ID 7.0 mm, OD 10.0 mm) with embedded camera (VivaSight-SLTM, ET-View Ltd, Misgav, Israel) (Figure 1), and with this secured in the trachea, lung isolation was obtained with the use of an bronchial blocker (VivaSight-EB, 9 Fr) on the left side, resulting in total lung collapse, allowing...

  9. Cherenkov luminescence measurements with digital silicon photomultipliers: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Ciarrocchi, Esther; Belcari, Nicola; Guerra, Alberto Del [Department of Physics, University of Pisa, Pisa (Italy); INFN, section of Pisa, Pisa (Italy); Cherry, Simon R. [Department of Biomedical Engineering, University of California, Davis, CA (United States); Lehnert, Adrienne; Hunter, William C. J.; McDougald, Wendy; Miyaoka, Robert S.; Kinahan, Paul E. [Department of Radiology, University of Washington, Seattle, WA (United States)

    2015-11-16

    A feasibility study was done to assess the capability of digital silicon photomultipliers to measure the Cherenkov luminescence emitted by a β source. Cherenkov luminescence imaging (CLI) is possible with a charge coupled device (CCD) based technology, but a stand-alone technique for quantitative activity measurements based on Cherenkov luminescence has not yet been developed. Silicon photomultipliers (SiPMs) are photon counting devices with a fast impulse response and can potentially be used to quantify β-emitting radiotracer distributions by CLI. In this study, a Philips digital photon counting (PDPC) silicon photomultiplier detector was evaluated for measuring Cherenkov luminescence. The PDPC detector is a matrix of avalanche photodiodes, which were read one at a time in a dark count map (DCM) measurement mode (much like a CCD). This reduces the device active area but allows the information from a single avalanche photodiode to be preserved, which is not possible with analog SiPMs. An algorithm to reject the noisiest photodiodes and to correct the measured count rate for the dark current was developed. The results show that, in DCM mode and at (10–13) °C, the PDPC has a dynamic response to different levels of Cherenkov luminescence emitted by a β source and transmitted through an opaque medium. This suggests the potential for this approach to provide quantitative activity measurements. Interestingly, the potential use of the PDPC in DCM mode for direct imaging of Cherenkov luminescence, as a opposed to a scalar measurement device, was also apparent. We showed that a PDPC tile in DCM mode is able to detect and image a β source through its Cherenkov radiation emission. The detector’s dynamic response to different levels of radiation suggests its potential quantitative capabilities, and the DCM mode allows imaging with a better spatial resolution than the conventional event-triggered mode. Finally, the same acquisition procedure and data processing could

  10. Solid-State Photomultiplier Development for Radiation Detection

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Stuart [NSTec; Brown, Kristina [NSTec; Curtis, Alden [NSTec; Young, Jason [NSTec; Guise, Ronald [NSTec

    2012-06-12

    We are pursuing the sensitivity of back-thinned silicon (BT Si) with the gain of an SSPM (Baker 2011). Working in collaboration with Radiation Monitoring Devices, Inc., we are designing and fabricating prototype devices. Our original idea spurred from hybrid designs of advanced image sensors that use the sensitivity of BT Si that is then bump bonded to a CMOS readout device. As shown in the graph below (right), the BT Si has a far superior quantum efficiency (QE) than the standard photocathode response available in photomultiplier tubes (PMTs). Collecting as many scintillation photons as possible is the first objective. There has been major concern that the prototype could not deliver the ~105 electronic gain of a PMT. However, recently developed SSPMs do provide the electronic gain needed. We are now pursuing the design of a BTSSPM. With a smaller footprint, the SSPM can potentially lead to a simple, compact deployment package. Because the SSPM can be pixelated and tiled, we foresee developing an imaging detector. Pinhole imaging of radiation sources is a well-exercised technology. Our implementation of the coded aperture (Marks 2010) imager provides a high throughput pinhole imager. We intend to apply miniature coded apertures to minimal pixel count SSPMs to evaluate image quality.

  11. Pressure drop-flow rate curves for single-phase steam in Combustion Engineering type steam generator U-tubes during severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Fynan, Douglas A.; Ahn, Kwang-Il, E-mail: kiahn@kaeri.re.kr

    2016-12-15

    Highlights: • Pressure drop-flow rate curves for superheated steam in U-tubes were generated. • Forward flow of hot steam is favored in the longer and taller U-tubes. • Reverse flow of cold steam is favored in short U-tubes. • Steam generator U-tube bundle geometry and tube diameter are important. • Need for correlation development for natural convention heat transfer coefficient. - Abstract: Characteristic pressure drop-flow rate curves are generated for all row numbers of the OPR1000 steam generators (SGs), representative of Combustion Engineering (CE) type SGs featuring square bend U-tubes. The pressure drop-flow rate curves are applicable to severe accident natural circulations of single-phase superheated steam during high pressure station blackout sequences with failed auxiliary feedwater and dry secondary side which are closely related to the thermally induced steam generator tube rupture event. The pressure drop-flow rate curves which determine the recirculation rate through the SG tubes are dependent on the tube bundle geometry and hydraulic diameter of the tubes. The larger CE type SGs have greater variation of tube length and height as a function of row number with forward flow of steam favored in the longer and taller high row number tubes and reverse flow favored in the short low row number tubes. Friction loss, natural convection heat transfer coefficients, and temperature differentials from the primary to secondary side are dominant parameters affecting the recirculation rate. The need for correlation development for natural convection heat transfer coefficients for external flow over tube bundles currently not modeled in system codes is discussed.

  12. Silicon photomultipliers for positron emission tomography detectors with depth of interaction encoding capability

    Energy Technology Data Exchange (ETDEWEB)

    Taghibakhsh, Farhad, E-mail: farhadt@sri.utoronto.ca [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Thunder Bay Regional Health Science Centre, Thunder Bay, ON (Canada); Reznik, Alla [Thunder Bay Regional Health Science Centre, Thunder Bay, ON (Canada); Department of Physics, Lake Head University, Thunder Bay, ON (Canada); Rowlands, John A. [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Thunder Bay Regional Health Science Centre, Thunder Bay, ON (Canada); Department of Physics, Lake Head University, Thunder Bay, ON (Canada)

    2011-05-15

    Silicon photomultipliers (SiPMs) are receiving increasing attention in the field of positron emission tomography (PET) detectors. Compared to photomultiplier tubes, they offer novel detector configurations for the extraction of depth of interaction (DOI) information, or enable emerging medical imaging modalities such as simultaneous PET-magnetic resonant imaging (MRI). In this article, we used 2x2x20 mm{sup 3} LYSO scintillator crystals coupled to SiPMs on both ends (dual-ended readout configuration) to evaluate the detector performance for DOI-PET applications. We investigated the effect of scintillator crystal surface finishing on sensitivity and resolution of DOI, as well as on energy and timing resolution. Measurements indicate DOI sensitivity and resolution of 7.1% mm{sup -1} and 2.1{+-}0.6 mm for saw-cut, and 1.3% mm{sup -1} and 9.0{+-}1.5 mm, for polished scintillator crystals, respectively. Energy resolution varies from 19% when DOI is in the center, to 15% with DOI at either end of the saw-cut crystal, while it remains constant at {approx}14% for polished scintillators. Based on our results we conclude that 2x2x20 mm{sup 3} saw-cut (without any special side wall polishing) LYSO crystals coupled to 2x2 mm{sup 2} silicon photomultipliers are optimal for isotropic 2 mm resolution DOI-PET applications.

  13. The long-term stability and reliability of photomultipliers used in Anger scintillation cameras

    International Nuclear Information System (INIS)

    Persyk, D.E.

    1991-01-01

    A test instrument has been designed to measure the stability of PMT's (photomultiplier tubes) used in Anger scintillation cameras. The instrument is comprised of a number of glass capsules containing beta-emitting tritium with a blue phosphor to provide very stable light sources along with a data logger to monitor anode current. Three hundred sixty PMT's are simultaneously tested for anode luminous sensitivity, dark current, long-term drift rate, erratic gain instabilities and rms noise. In this paper results in the use of the instrument to test over 300 000 PMTs are discussed and the impact upon Auger camera reliability is assessed

  14. The long-term stability and reliability of photomultipliers used in Anger scintillation cameras

    International Nuclear Information System (INIS)

    Persyk, D. E.

    1990-01-01

    A test instrument has been designed to measure the stability of PMT's (photomultiplier tubes) used in Anger scintillation cameras. The instrument is comprised of a number of glass capsules containing beta-emitting tritium with a blue phosphor to provide very stable light sources along with a data logger to monitor anode current. Three hundred sixty PMT's are simultaneously tested for anode luminous sensitivity, dark current, long-term drift rate, erratic gain instabilities and rms noise. This paper discusses results in the use of the instrument to test over 300 000 PMT's and the impact upon Anger camera reliability is assessed

  15. General correlations for pressure drop and heat transfer for single-phase turbulent flow in internally ribbed tubes

    International Nuclear Information System (INIS)

    Ravigururajan, T.S.; Bergles, A.E.

    1985-01-01

    General correlations for friction factors and heat transfer coefficients for single-phase turbulent flow in internally ribbed tubes are presented. Data from previous investigations are gathered for a wide range of tube parameters with e/d: 0.01 to 0.2; p/d: 0.1 to 7.0; α/90: 0.3 to 1.0, and flow parameters Re: 5000 to 250,000 and Pr: 0.66 to 37.6. The data were applied to a linear model to get normalized correlations that were then modified to fit tubes with extremely small parametric values. A shape function was included in the friction correlation to account for different rib profiles. The friction correlation predicts 96% of the data base to within +. 50% and 77% of the data base to within +. 20%. Corresponding figures for the heat transfer correlation are 99% and 69%. The present correlations are superior, for this extensive data base, to those presented by other investigators

  16. Muon tracking system with Silicon Photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Arneodo, F.; Benabderrahmane, M.L.; Dahal, S. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Di Giovanni, A., E-mail: adriano.digiovanni@nyu.edu [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Pazos Clemens, L. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Candela, A.; D' Incecco, M.; Sablone, D. [Gran Sasso National Laboratory of INFN, Assergi (Italy); Franchi, G. [AGE Scientific Srl, Capezzano Pianore (Italy)

    2015-11-01

    We report the characterisation and performance of a low cost muon tracking system consisting of plastic scintillator bars and Silicon Photomultipliers equipped with a customised front-end electronics based on a fast preamplifier network. This system can be used as a detector test bench for astroparticle physics and for educational and outreach purposes. We investigated the device behaviour in self-trigger and coincidence mode, without using LED and pulse generators, showing that with a relatively simple set up a complete characterisation work can be carried out. A high definition oscilloscope, which can easily be found in many university physics or engineering departments, has been used for triggering and data acquisition. Its capabilities have been exploited to discriminate real particles from the background.

  17. Thermal and structural performance of a single tube support post for the Superconducting Super Collider dipole magnet cryostat

    International Nuclear Information System (INIS)

    Boroski, W.N.; Nicol, T.H.; Ruschman, M.K.; Schoo, C.J.

    1993-07-01

    The reentrant support post currently incorporated in the Superconducting Super Collider (SSC) dipole cryostat has been shown to meet the structural and thermal requirements of the cryostat, both in prototype magnet assemblies and through component testing. However, the reentrant post design has two major drawbacks: tight dimensional control on all components, and cost driven by these tolerance constraints and a complex assembly procedure. A single tube support post has been developed as an alternative to the reentrant post design. Several prototype assemblies have been fabricated and subjected to structural testing. Compressive, tensile, and bending forces were applied to each assembly with deflection measured at several locations. A prototype support post has also been thermally evaluated in a heat leak measurement facility. Heat load to 4.2 K was measured with the intermediate post intercept operating at various temperatures while thermometers positioned along the conductive path of the post mapped thermal gradients. Results from these measurements indicate the single tube support post meets the design criteria for the SSC dipole magnet cryostat support system

  18. Optimization of the Divergent method for genotyping single nucleotide variations using SYBR Green-based single-tube real-time PCR.

    Science.gov (United States)

    Gentilini, Fabio; Turba, Maria E

    2014-01-01

    A novel technique, called Divergent, for single-tube real-time PCR genotyping of point mutations without the use of fluorescently labeled probes has recently been reported. This novel PCR technique utilizes a set of four primers and a particular denaturation temperature for simultaneously amplifying two different amplicons which extend in opposite directions from the point mutation. The two amplicons can readily be detected using the melt curve analysis downstream to a closed-tube real-time PCR. In the present study, some critical aspects of the original method were specifically addressed to further implement the technique for genotyping the DNM1 c.G767T mutation responsible for exercise-induced collapse in Labrador retriever dogs. The improved Divergent assay was easily set up using a standard two-step real-time PCR protocol. The melting temperature difference between the mutated and the wild-type amplicons was approximately 5°C which could be promptly detected by all the thermal cyclers. The upgraded assay yielded accurate results with 157pg of genomic DNA per reaction. This optimized technique represents a flexible and inexpensive alternative to the minor grove binder fluorescently labeled method and to high resolution melt analysis for high-throughput, robust and cheap genotyping of single nucleotide variations. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. In situ Raman spectroelectrochemistry as a tool for the differentiation of inner tubes of double-wall carbon nanotubes and thin single-wall carbon nanotubes.

    Science.gov (United States)

    Kalbác, Martin; Kavan, Ladislav; Dunsch, Lothar

    2007-12-01

    In situ Raman spectroelectrochemistry has been used to distinguish between thin single-wall carbon nanotubes (SWCNT) and the inner tubes of double-wall carbon nanotubes (DWCNT). The spectroelectrochemical method is based on the different change of the electronic structure of the inner tube in DWCNT and that of SWCNT during electrochemical charging, which is reflected in the Raman spectra. During electrochemical charging the inner tubes of DWCNT exhibit a delayed attenuation of the intensities of their Raman modes as referred to the behavior of SWCNT of similar diameter. The changes are pronounced for the radial breathing mode (RBM), and thus, these modes are diagnostic for the distinction of inner tubes of DWCNT from the thin SWCNT. The different sensitivities of inner and outer tubes to the applied electrochemical charging is a simple analytical tool for differentiation of SWCNT and DWCNT in a mixture. The significance of the proposed method is demonstrated on a commercial DWCNT sample.

  20. High-efficiency 3 W/40 K single-stage pulse tube cryocooler for space application

    Science.gov (United States)

    Zhang, Ankuo; Wu, Yinong; Liu, Shaoshuai; Liu, Biqiang; Yang, Baoyu

    2018-03-01

    Temperature is an extremely important parameter for space-borne infrared detectors. To develop a quantum-well infrared photodetector (QWIP), a high-efficiency Stirling-type pulse tube cryocooler (PTC) has been designed, manufactured and experimentally investigated for providing a large cooling power at 40 K cold temperature. Simulated and experimental studies were carried out to analyse the effects of low temperature on different energy flows and losses, and the performance of the PTC was improved by optimizing components and parameters such as regenerator and operating frequency. A no-load lowest temperature of 26.2 K could be reached at a frequency of 51 Hz, and the PTC could efficiently offer cooling power of 3 W at 40 K cold temperature when the input power was 225 W. The efficiency relative to the Carnot efficiency was approximately 8.4%.

  1. SSC 50 MM collider dipole cryostat single tube support post conceptual design and analysis

    International Nuclear Information System (INIS)

    Nicol, T.H.

    1992-01-01

    Superconducting Super Collider (SSC) dipole magnet cold masses are connected to the cryostat vacuum vessel at five places equally spaced along their length. Five supports limit sag of the cold assembly due to its own weight to a level consistent with the final magnet alignment specifications. The design essentially consists of two composite tubes nested within each other as a means of maximizing the thermal path length. In addition it provides an ideal way to utilize materials best suited for the temperature range over which they must operate. Filament wound S-glass is used between 300K and 80K. Filament wound graphite fiber is used between 80K and 20K and between 20K and 4.5K. S-glass is a better thermal performer above approximately 40K. Graphite composites are ideally suited for operation below 40K. The designs for the 50 mm reentrant supports are well documented in the literature. The current design of the reentrant support has two major drawbacks. First, it requires very tight dimensional control on all components; composite tubes and metal attachment parts. Second, it is expensive, with cost being driven by both the tolerance constraints and by a complex assembly procedure. It seems clear that production magnets will require a support structure which is considerably less expensive than that which is currently used. It seems clear that a design alternate for reentrant support posts will be required for production dipoles primarily due to their cost. It seems less clear that injection molded composite materials are the ideal choice. This report describes the conceptual design for a support post whose function is identical to that of the current reentrant design, which requires very few modifications to surrounding cryostat components, is thermally equivalent to the current 50 mm support post, and is nearly equivalent structurally

  2. COMPARISON OF DOUBLE AND SINGLE PIERCING PROCESS IN SEAMLESS STEEL TUBE MANUFACTURE

    OpenAIRE

    Chihiro, HAYASHI; Tomio, YAMAKAWA; Corporate Research and Development Laboratories, Sumitomo Metal Industries, Ltd.; Corporate Research and Development Laboratories, Sumitomo Metal Industries, Ltd.

    1997-01-01

    An investigation work was made on the influence of the piercing process on the rotary forging effects, redundant shear deformations and power consumption. In this work, a study was made to compare the double and single piercing process with reference to the Mannesmann piercing mill and the cone-type piercing mill developed by the authors. If the conventional double piercing process employing the Mannesmann piercing mill is replaced by the single piercing process employing the cone-type pierci...

  3. Development of a large area microstructure photomultiplier assembly (LAMPA)

    Science.gov (United States)

    Clifford, E. T. H.; Dick, M.; Facina, M.; Wakeford, D.; Andrews, H. R.; Ing, H.; Best, D.; Baginski, M. J.

    2017-05-01

    Large area (> m2) position-sensitive readout of scintillators is important for passive/active gamma and neutron imaging for counter-terrorism applications. The goal of the LAMPA project is to provide a novel, affordable, large-area photodetector (8" x 8") by replacing the conventional dynodes of photomultiplier tubes (PMTs) with electron multiplier microstructure boards (MSBs) that can be produced using industrial manufacturing techniques. The square, planar format of the LAMPA assemblies enables tiling of multiple units to support large area applications. The LAMPA performance objectives include comparable gain, noise, timing, and energy resolution relative to conventional PMTs, as well as spatial resolution in the few mm range. The current LAMPA prototype is a stack of 8" x 8" MSBs made commercially by chemical etching of a molybdenum substrate and coated with hydrogen-terminated boron-doped diamond for high secondary emission yield (SEY). The layers of MSBs are electrically isolated using ceramic standoffs. Field-shaping grids are located between adjacent boards to achieve good transmission of electrons from one board to the next. The spacing between layers and the design of the microstructure pattern and grids were guided by simulations performed using an electro-optics code. A position sensitive anode board at the back of the stack of MSBs provides 2-D readout. This presentation discusses the trade studies performed in the design of the MSBs, the measurements of SEY from various electro-emissive materials, the electro-optics simulations conducted, the design of the 2-D readout, and the mechanical aspects of the LAMPA design, in order to achieve a gain of > 104 in an 8-stage stack of MSBs, suitable for use with various scintillators when coupled to an appropriate photocathode.

  4. Syndromes and Disorders Associated with Omphalocele (III: Single Gene Disorders, Neural Tube Defects, Diaphragmatic Defects and Others

    Directory of Open Access Journals (Sweden)

    Chih-Ping Chen

    2007-06-01

    Full Text Available Omphalocele can be associated with single gene disorders, neural tube defects, diaphragmatic defects, fetal valproate syndrome, and syndromes of unknown etiology. This article provides a comprehensive review of omphalocele-related disorders: otopalatodigital syndrome type II; Melnick–Needles syndrome; Rieger syndrome; neural tube defects; Meckel syndrome; Shprintzen–Goldberg omphalocele syndrome; lethal omphalocele-cleft palate syndrome; cerebro-costo-mandibular syndrome; fetal valproate syndrome; Marshall–Smith syndrome; fibrochondrogenesis; hydrolethalus syndrome; Fryns syndrome; omphalocele, diaphragmatic defects, radial anomalies and various internal malformations; diaphragmatic defects, limb deficiencies and ossification defects of skull; Donnai–Barrow syndrome; CHARGE syndrome; Goltz syndrome; Carpenter syndrome; Toriello–Carey syndrome; familial omphalocele; Cornelia de Lange syndrome; C syndrome; Elejalde syndrome; Malpuech syndrome; cervical ribs, Sprengel anomaly, anal atresia and urethral obstruction; hydrocephalus with associated malformations; Kennerknecht syndrome; lymphedema, atrial septal defect and facial changes; and craniosynostosis- mental retardation syndrome of Lin and Gettig. Perinatal identification of omphalocele should alert one to the possibility of omphalocele-related disorders and familial inheritance and prompt a thorough genetic counseling for these disorders.

  5. Supplemental tube feeding does not mitigate weight loss in infants with shunt-dependent single-ventricle physiology.

    Science.gov (United States)

    Di Maria, Michael V; Glatz, Andrew C; Ravishankar, Chitra; Quartermain, Michael D; Rush, Christina Hayden; Nance, Michael; William Gaynor, J; Goldberg, David J

    2013-08-01

    Infants with shunt-dependent single-ventricle (SV) physiology are at risk for poor weight gain before superior cavopulmonary connection (SCPC). Lower weight-for-age z-score is a risk factor for prolonged length of stay (LOS) after SCPC. We sought to characterize infant growth and feeding and determine the effect of method of feeding on outcomes. Chart review of infants with shunt-dependent SV physiology born between October 2007 and September 2010 was performed. The cohort was divided into three groups based on feeding method at discharge after initial palliation; 53 in the oral feeding (PO) group, 56 in the nasogastric (NG) tube group, and 26 in the gastrostomy tube (GT) group. Birth weight z-score did not differ among groups (p = 0.39), but infants fed by NG or GT were smaller than PO-fed infants at hospital discharge (p = 0.0001), a difference that persisted through SCPC (p SCPC did not differ among groups. Risk factors for longer LOS at SCPC included longer LOS and need for supplemental feeds at discharge from initial palliation as well as lower weight at SCPC. Poor growth is common among infants with shunt-dependent SV physiology. Infants who require GT have lower weight-for-age z-scores at hospital discharge and remain smaller at SCPC than those fed PO. Although GT after initial palliation is associated with longer LOS after SCPC, it is not associated with an increase in interstage morbidity or mortality.

  6. Statistical analysis of entropy generation in longitudinally finned tube heat exchanger with shell side nanofluid by a single phase approach

    Directory of Open Access Journals (Sweden)

    Konchada Pavan Kumar

    2016-06-01

    Full Text Available The presence of nanoparticles in heat exchangers ascertained increment in heat transfer. The present work focuses on heat transfer in a longitudinal finned tube heat exchanger. Experimentation is done on longitudinal finned tube heat exchanger with pure water as working fluid and the outcome is compared numerically using computational fluid dynamics (CFD package based on finite volume method for different flow rates. Further 0.8% volume fraction of aluminum oxide (Al2O3 nanofluid is considered on shell side. The simulated nanofluid analysis has been carried out using single phase approach in CFD by updating the user-defined functions and expressions with thermophysical properties of the selected nanofluid. These results are thereafter compared against the results obtained for pure water as shell side fluid. Entropy generated due to heat transfer and fluid flow is calculated for the nanofluid. Analysis of entropy generation is carried out using the Taguchi technique. Analysis of variance (ANOVA results show that the inlet temperature on shell side has more pronounced effect on entropy generation.

  7. Stress in closed thin-walled tubes of single box subjected by shear forces and application to airfoils

    Directory of Open Access Journals (Sweden)

    Zebbiche Toufik

    2014-09-01

    Full Text Available The presented work is to develop a numerical computation program to determine the distribution of the shear stress to shear in closed tubes with asymmetric single thin wall section with a constant thickness and applications to airfoils and therefore determining the position and value of the maximum stress. In the literature, there are exact analytical solutions only for some sections of simple geometries such as circular section. Hence our interest is focused on the search of approximate numerical solutions for more complex sections used in aeronautics. In the second stage the position of the shear center is determined so that the section does not undergo torsion. The analytic function of the boundary of the airfoil is obtained by using the cubic spline interpolation since it is given in the form of tabulated points.

  8. Ultrananocrystalline diamond decoration on to the single wall carbon nano tubes

    Science.gov (United States)

    Sinha, Bhavesh; Late, Datta; Jejurikar, Suhas M.

    2017-10-01

    We have demonstrated the decoration of the ultrananocrystalline diamonds on single walled carbon nanotubes using a hot filament assisted chemical vapor deposition. Study reveals the critical influence of the filament to substrate distance on the formation of ultrananocrystalline diamonds on to the single walled carbon nanotubes. It is also observed that etching of carbon nanotubes, due to the presence of unavoidable atomic hydrogen throughout the chemical vapor deposition processes, can be significantly reduced by adjusting the filament to substrate distance. Morphological and structural investigations performed using high resolution transmission electron microscope suggests the growth of ultrananocrystalline diamond is subsequent to the formation of crystalline sp2 carbon layer on the nanotube wall, enabling us to suggest a growth model. The composite synthesized can be thought not only to use as a fuel cell catalyst support but also as chemical sensors, bio-sensors and micro electromechanical systems (MEMS).

  9. Influence of incident light wavelength on time jitter of fast photomultipliers

    International Nuclear Information System (INIS)

    Moszynski, M.; Vacher, J.

    1977-01-01

    The study of the single photoelectron time resolution as a function of the wavelength of the incident light was performed for a 56 CVP photomultiplier having an S-1 photocathode. The light flash from the XP22 light emitting diode generator was passed through passband filters and illuminated the 5 mm diameter central part of the photocathode. A significant increase of the time resolution above 30% was observed when the wavelength of the incident light was changed from 790 nm to 580 nm. This gives experimental evidence that the time jitter resulting from the spread of the initial velocity of photoelectrons is proportional to the square root of the maximal initial energy of photoelectrons. Based on this conclusion the measured time jitter of C31024, RCA8850 and XP2020 photomultipliers with the use of the XP22 light emitting diode at 560 nm light wavelength was recalculated to estimate the time jitter at 400 nm near the maximum of the photocathode sensitivity. It shows an almost twice larger time spread at 400 nm for the C31024 and RCA8850 with a high gain first dynode and an about 1.5 times larger time spread for the XP2020 photomultiplier, than those measured at 560 nm. (Auth.)

  10. Replacing a double-lumen tube with a single-lumen tube or a laryngeal mask airway device to reduce coughing at emergence after thoracic surgery: a randomized controlled single-blind trial.

    Science.gov (United States)

    Tanoubi, Issam; Sun, Joanna Ng Man; Drolet, Pierre; Fortier, Louis-Philippe; Donati, François

    2015-09-01

    Coughing episodes occur frequently at extubation after thoracic surgery, and this may be due in part to the double-lumen tube (DLT). In this study, the DLT was replaced with either a single-lumen endotracheal tube (ETT) or a laryngeal mask airway (LMA) device or left in place, and the incidence of coughing at emergence was compared between the three groups. Fifty-eight adults scheduled for thoracic surgery with a DLT were included. Exclusion criteria were an anticipated difficult airway, obesity, and contraindication to the use of an LMA ProSeal™ (LMA-P). After surgery but before emergence, patients were randomized to having the DLT (1) removed and replaced by an LMA-P (LMA-P Group), (2) removed and replaced by an ETT (ETT Group), or (3) left in place (DLT Group). The primary outcome was the number of coughing episodes at extubation. Among 184 patients screened, 124 did not meet inclusion criteria, and two patients, both in the ETT Group, were excluded after randomization, leaving 20, 18, and 20 patients in the LMA-P, ETT, and DLT Groups, respectively. There were fewer coughing episodes (median [quartiles]) in the LMA-P Group than in the DLT Group (0[0-1] vs 2[1-3], respectively; P = 0.01). In the DLT Group, 90% of patients coughed at least once. This incidence was not significantly different in the ETT Group (83%; P = 0.222) but was significantly reduced in the LMA-P Group (35%; P replaced by an LMA-P before emergence. The number of patients in this trial was too small to evaluate the risks associated with exchanging the airway device. This trial was registered at ClinicalTrials.gov: NCT00925613.

  11. Tube Current Modulation Between Single- and Dual-Energy CT With a Second-Generation Dual-Source Scanner: Radiation Dose and Image Quality.

    Science.gov (United States)

    Matsubara, Kosuke; Takata, Tadanori; Kobayashi, Masanao; Kobayashi, Satoshi; Koshida, Kichiro; Gabata, Toshifumi

    2016-08-01

    The purpose of this study was to compare the effects of tube current modulation between single- and dual-energy CT with a second-generation dual-source scanner. Custom-made elliptic polymethylmethacrylate phantoms for slim and large patients were used. Absorbed radiation dose at the central point of the phantoms was measured with a solid-state detector while the phantoms were scanned in single-energy (120 kV) and dual-energy (100/Sn140, 80/Sn140, and 140/80 kV) modes with a second-generation dual-source CT scanner. Tube current modulation was activated in both modes, and quality reference tube current-time settings of 150, 300, 450, and 600 mAs were selected. Scanning was performed three times under the same conditions, and image noise was evaluated by measuring the SD of CT numbers in four separate regions of three adjacent images of the phantoms. Absorbed dose increased and image noise decreased with an increase in quality reference tube current-time setting when the slim phantom was scanned. For the large phantom, the radiation dose and noise level reached a plateau above quality reference tube current-time settings of 300 mAs for 100/Sn140 kV and 450 mAs for 120 kV. The radiation dose was small and the noise level was large with 80/Sn140 kV compared with that obtained with 120 and 100/Sn140 kV at all quality reference tube current-time settings. When a large phantom is scanned with 100/Sn140 kV, exposure demand for tube current modulation exceeds system limits at a lower quality reference tube current-time setting than for scanning 120 kV.

  12. Pulse shape discrimination performance of stilbene coupled to low-noise silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Ruch, Marc Lavi, E-mail: mruch@umich.edu; Flaska, Marek; Pozzi, Sara A

    2015-09-01

    Pulse shape discrimination (PSD) techniques can be used to discern between neutron and gamma-ray interactions in certain organic scintillators. Traditionally, photomultiplier tubes (PMTs) have been used in organic-scintillator assemblies. However, silicon photomultipliers (SiPMs) have great potential to be used in many applications in which PMTs have been predominantly used, including those utilizing PSD techniques. To evaluate the current state of the art of the SiPM technology, SensL's 6-mm B-Series and C-Series SiPMs were compared to a fast Hamamatsu PMT in conjunction with a 6×6×6-mm{sup 3} stilbene organic scintillator to assess the PSD performance of the detector assemblies. Measurements with a Cf-252 source were performed and a figure of merit (FOM) for discriminating between neutron and gamma-ray pulses between 100 keVee and 200 keVee was calculated for each assembly. A digital charge-integration PSD technique was used to process all measured data. The FOM for the B-Series SiPM, PMT, and C-Series SiPM was 1.37, 1.93, and 2.13, respectively. The C-Series SiPM was shown to perform as well as the PMT in the experiments. - Highlights: • Silicon photomultipliers show potential for use in applications that employ PMTs. • SensL C-Series SiPMs have 21% reduction in RMS noise compared to B-Series. • PSD using stilbene coupled to SiPM has improved significantly with low-noise SiPMs. • Such SiPMs can be used to perform PSD as well as PMTs using simple PSD algorithms.

  13. Association between maternal single nucleotide polymorphisms in genes regulating glucose metabolism and risk for neural tube defects in offspring.

    Science.gov (United States)

    Fu, Yunting; Wang, Lin-lin; Yi, Deqing; Jin, Lei; Liu, Jufen; Zhang, Yali; Ren, Aiguo

    2015-06-01

    Maternal pregestational hyperglycemia, diabetes, and obesity are well-established risk factors for neural tube defects (NTDs). As a common underlying mechanism, the imbalance of glucose homeostasis is directly related to the development of NTDs. Polymorphisms in genes regulating glucose metabolism in women may impact their chance of having an NTD-affected pregnancy. We conducted a two-stage case-control study to investigate the association between maternal genetic variants in genes regulating glucose metabolism and risk for NTDs. The cases were 547 women who gave birth to a child with an NTD (anencephaly, spina bifida, or encephalocele); the controls were 543 women who gave birth to a full-term healthy infant. In the first stage, 12 single nucleotide polymorphisms were genotyped in 160 cases and 162 controls. In the second stage, five single nucleotide polymorphisms found in the first stage and potentially associated with NTD risk were genotyped for validation, in an additional 387 cases and 381 controls. Combined analysis of data from the two stages showed an association between maternal AA genotype of GCKR rs780094 and increased risk for total NTDs [odds ratio, 1.73; 95% confidence interval, 1.16-2.59) and spina bifida subtype [odds ratio, 1.83; 95% confidence interval, 1.16-2.88). No association was found between the other four single nucleotide polymorphisms (LEPR rs1137100, HK1 rs748235, HHEX rs5015480, KCNQ1 rs2237892) and NTD risk. The AA genotype in maternal GCKR rs780094 is associated with an increased risk for NTDs and spina bifida in the Chinese population. © 2014 Wiley Periodicals, Inc.

  14. Studies on a silicon-photomultiplier-based camera for Imaging Atmospheric Cherenkov Telescopes

    Science.gov (United States)

    Arcaro, C.; Corti, D.; De Angelis, A.; Doro, M.; Manea, C.; Mariotti, M.; Rando, R.; Reichardt, I.; Tescaro, D.

    2017-12-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) represent a class of instruments which are dedicated to the ground-based observation of cosmic VHE gamma ray emission based on the detection of the Cherenkov radiation produced in the interaction of gamma rays with the Earth atmosphere. One of the key elements of such instruments is a pixelized focal-plane camera consisting of photodetectors. To date, photomultiplier tubes (PMTs) have been the common choice given their high photon detection efficiency (PDE) and fast time response. Recently, silicon photomultipliers (SiPMs) are emerging as an alternative. This rapidly evolving technology has strong potential to become superior to that based on PMTs in terms of PDE, which would further improve the sensitivity of IACTs, and see a price reduction per square millimeter of detector area. We are working to develop a SiPM-based module for the focal-plane cameras of the MAGIC telescopes to probe this technology for IACTs with large focal plane cameras of an area of few square meters. We will describe the solutions we are exploring in order to balance a competitive performance with a minimal impact on the overall MAGIC camera design using ray tracing simulations. We further present a comparative study of the overall light throughput based on Monte Carlo simulations and considering the properties of the major hardware elements of an IACT.

  15. Neutron detection with plastic scintillators coupled to solid state photomultiplier detectors

    Science.gov (United States)

    Christian, James F.; Johnson, Erik B.; Fernandez, Daniel E.; Vogel, Samuel; Frank, Rebecca; Stoddard, Graham; Stapels, Christopher; Pereira, Jorge; Zegers, Remco

    2017-09-01

    The recent reduction of dark current in Silicon Solid-state photomultipliers (SiSSPMs) makes them an attractive alternative to conventional photomultiplier tubes (PMTs) for scintillation detection applications. Nuclear Physics experiments often require large detector volumes made using scintillation materials, which require sensitive photodetectors, such as a PMTs. PMTs add to the size, fragility, and high-voltage requirements as well as distance requirements for experiments using magnetic fields. This work compares RMD's latest detector modules, denoted as the "year 2 prototype", of plastic scintillators that discriminate gamma and high-energy particle events from neutron events using pulse shape discrimination (PSD) coupled to a SiSSPM to the following two detector modules: a similar "year 1 prototype" and a scintillator coupled to a PMT module. It characterizes the noise floor, relative signal-to-noise ratio (SNR), the timing performance, the PSD figure-of-merit (FOM) and the neutron detection efficiency of RMD's detectors. This work also evaluates the scaling of SiSSPM detector modules to accommodate the volumes needed for many Nuclear Physics experiments. The Si SSPM detector module provides a clear advantage in Nuclear Physics experiments that require the following attributes: discrimination of neutron and gamma-ray events, operation in or near strong magnetic fields, and segmentation of the detector.

  16. Experimental study of non-linear effects on photomultiplier gain

    International Nuclear Information System (INIS)

    De Vincenzi, M.; Penso, G.; Sciubba, A.; Sposito, A.

    1984-01-01

    The experimental apparatus and the results of a study on the gain variation of photomultipliers at high average anode current are described. This gain variation was found to depend on the secondary emission process on dynodes; the last dynode gives the largest contribution to the overall photomultiplier effect. This contribution has been isolated and measured. The phenomenon may be due to more than one physical effect. The dominant one turns out to depend on the power released on the dynode by the incident electrons. A physical model is discussed which can take into account the observed phenomena. (orig.)

  17. Inner tube growth and electronic properties of metallicity-sorted nickelocene-filled semiconducting single-walled carbon nanotubes

    Science.gov (United States)

    Kharlamova, M. V.; Kramberger, C.; Sauer, M.; Yanagi, K.; Saito, T.; Pichler, T.

    2018-03-01

    In the present work, we have obtained metallicity-sorted nickelocene-filled semiconducting single-walled carbon nanotubes (SWCNTs) by density gradient separation of metallicity mixed filled nanotubes. Double-walled carbon nanotubes (DWCNTs) were obtained by annealing of filled SWCNTs in vacuum. The diameter distribution of inner tubes was analyzed by multifrequency Raman spectroscopy. The chemical transformation of nickelocene upon annealing was studied by X-ray photoelectron spectroscopy (XPS) at the Ni 2 p core level. The thermally-induced transformation of nickelocene to nickel carbides and metallic nickel was revealed. The electronic properties of the filled SWCNTs and DWCNTs were investigated by XPS at the C 1 s core level. By tracing the C 1 s binding energy, it was shown that the annealing of nickelocene-filled SWCNTs at low temperatures (360-600 °C) led to electron doping of SWCNTs, whereas annealing at high temperatures and formation of DWCNTs (680-1200 °C) resulted in hole doping of nanotubes.

  18. Determination of a cross-sectional void fraction in a tube bundle using a single beam gamma densitometer

    International Nuclear Information System (INIS)

    Guichard, J.; Mezoul, B.; Peturaud, P.; Thomas, B.

    1991-06-01

    In order to qualify 3-dimensional two-phase flow computer codes modelling average flows in tube bundles, cross-section average void fractions must be measured over sub-channels. On the VATICAN mockup, such void fractions(integrated on the mockup thickness) are determined using a single (narrow) beam gamma densitometer. But to avoid a refined exploration of each measurement mesh, for each test, empirical calibration curves have been developed in a regular mesh of the mockup, in axial flow conditions. These calibration curves, which evaluate the sought cross-sectional value as a function of a chordal void fraction (right in the inter-rod gap) depend only on heat flux density and pressure. The data are consistent with the ARMAND-MASSENA and LELLOUCHE-ZOLOTAR slip correlations, and they are fitted by 3rd degree polynomials, for each heat flux density investigated, with a good accuracy. Unfortunately, preliminary testing and analysis indicate that the use of these calibration curves in subcooled boiling and transverse mixing zones might result in significant uncertainties and errors

  19. Development and validation of a single-tube multiple-locus variable number tandem repeat analysis for Klebsiella pneumoniae.

    Directory of Open Access Journals (Sweden)

    Antoinette A T P Brink

    Full Text Available Genotyping of Klebsiella pneumoniae is indispensable for management of nosocomial infections, monitoring of emerging strains--including extended-spectrum beta-lactamase (ESBL producers-, and general epidemiology. Such objectives require a high-resolution genotyping method with a fixed scheme that allows (1 long-term retrospective and prospective assessment, (2 objective result readout and (3 library storage for database development and exchangeable results. We have developed a multiple-locus variable number tandem repeat analysis (MLVA using a single-tube fluorescently primed multiplex PCR for 8 Variable Number Tandem Repeats (VNTRs and automated fragment size analysis. The type allocation scheme was optimized using 224 K. pneumoniae clinical isolates, which yielded 101 MLVA types. The method was compared to the gold standard multilocus sequence typing (MLST using a subset of these clinical isolates (n = 95 and found to be highly concordant, with at least as high a resolution but with considerably less hands-on time. Our results position this MLVA scheme as an appropriate, high-throughput and relatively low-cost tool for K. pneumoniae epidemiology.

  20. Evaluation of a new single-tube multiprobe real-time PCR for diagnosis of Entamoeba histolytica and Entamoeba dispar.

    Science.gov (United States)

    Liang, Shih-Yu; Hsia, Kan-Tai; Chan, Yun-Hsien; Fan, Chia-Kwung; Jiang, Donald Dah-Shyong; Landt, Olfert; Ji, Dar-Der

    2010-08-01

    A single-tube multiprobe real-time PCR assay for simultaneous detection of Entamoeba histolytica and Entamoeba dispar was developed. One primer pair with 2 species-specific probes was designed based on new SSU RNA regions of the ribosomal DNA-containing episome. The sensitivity is 1 parasite per milliliter of feces and thus superior to the conventional nested PCR and comparable to other published real-time PCR protocols. The applicability for clinical diagnosis was validated with 218 stool specimens from patients. A total of 51 E. histolytica and 39 E. dispar positive samples was detected by the multiprobe real-time PCR compared to 39 and 22 by routine nested PCR diagnosis. The detection rate of Entamoeba species for the multiprobe real-time PCR assays was significantly higher than the nested PCR (40.8% vs. 28.0%, P Entamoeba moshkovskii, Giardia lamblia , Cryptosporidium sp., Escherichia coli , or other nonpathogenic enteric parasites. The multiprobe real-time PCR assay is simple and rapid and has high specificity and sensitivity. The assay could streamline the laboratory diagnosis procedure and facilitate epidemiological investigation.

  1. Development and evaluation of one step single tube multiplex RT-PCR for rapid detection and typing of dengue viruses

    Directory of Open Access Journals (Sweden)

    Parida Manmohan

    2008-01-01

    Full Text Available Abstract Background Dengue is emerging as a major public health concern in many parts of the world. The development of a one-step, single tube, rapid, and multiplex reverse transcription polymerase chain reaction (M-RT-PCR for simultaneous detection and typing of dengue virus using serotype specific primers during acute phase of illness is reported. Results An optimal assay condition with zero background was established having no cross-reaction with closely related members of flavivirus (Japanese encephalitis, West Nile, Yellow fever and alphavirus (Chikungunya. The feasibility of M-RT-PCR assay for clinical diagnosis was validated with 620 acute phase dengue patient sera samples of recent epidemics in India. The comparative evaluation vis a vis conventional virus isolation revealed higher sensitivity. None of the forty healthy serum samples screened in the present study revealed any amplification, thereby establishing specificity of the reported assay for dengue virus only. Conclusion These findings clearly suggested that M-RT-PCR assay reported in the present study is the rapid and cost-effective method for simultaneous detection as well as typing of the dengue virus in acute phase patient serum samples. Thus, the M-RT-PCR assay developed in this study will serve as a very useful tool for rapid diagnosis and typing of dengue infections in endemic areas.

  2. A single-tube 27-plex SNP assay for estimating individual ancestry and admixture from three continents.

    Science.gov (United States)

    Wei, Yi-Liang; Wei, Li; Zhao, Lei; Sun, Qi-Fan; Jiang, Li; Zhang, Tao; Liu, Hai-Bo; Chen, Jian-Gang; Ye, Jian; Hu, Lan; Li, Cai-Xia

    2016-01-01

    A single-tube multiplex assay of a small set of ancestry-informative markers (AIMs) for effectively estimating individual ancestry and admixture is an ideal forensic tool to trace the population origin of an unknown DNA sample. We present a newly developed 27-plex single nucleotide polymorphism (SNP) panel with highly robust and balanced differential power to perfectly assign individuals to African, European, and East Asian ancestries. Evaluating 968 previously described intercontinental AIMs from three HapMap population genotyping datasets (Yoruban in Ibadan, Nigeria (YRI); Utah residents with Northern and Western European ancestry from the Centre de'Etude du Polymorphism Humain (CEPH) collection (CEU); and Han Chinese in Beijing, China (CHB)), the best set of markers was selected on the basis of Hardy-Weinberg equilibrium (p > 0.00001), population-specific allele frequency (two of three δ values >0.5), according to linkage disequilibrium (r (2) ancestry of the 11 populations in the HapMap project. Then, we tested the 27-plex SNP assay with 1164 individuals from 17 additional populations. The results demonstrated that the SNP panel was successful for ancestry inference of individuals with African, European, and East Asian ancestry. Furthermore, the system performed well when inferring the admixture of Eurasians (EUR/EAS) after analyzing admixed populations from Xinjiang (Central Asian) as follows: Tajik (68:27), Uyghur (49:46), Kirgiz (40:57), and Kazak (36:60). For individual analyses, we interpreted each sample with a three-ancestry component percentage and a population match probability sequence. This multiplex assay is a convenient and cost-effective tool to assist in criminal investigations, as well as to correct for the effects of population stratification for case-control studies.

  3. Two types of photomultiplier voltage dividers for high and changing count rates

    International Nuclear Information System (INIS)

    Reiter, W.L.; Stengl, G.

    1980-01-01

    We report on the design of two types of voltage distribution circuits for high stability photomultiplier operation. 'Type A' voltage divider is an ohmic voltage divider with high bleeder current (up to 10 mA) and the resistor chain split at one of the last dynodes, usually the dynode where the analog signal is derived from. This simple constructive measure improves the stability of the dynode voltage by a factor of 5 compared with an unsplit conventional resistor chain. 'Type B' is a novel active voltage divider using cold cathode tubes ar regulating elements. This voltage divider exhibits excellent temperature stability (about 10 -4 / 0 C). With 'type B' an equal stability compared with conventional ohmic dividers can be achieved at a bleeder current smaller by one order of magnitude. Of course both concepts, 'type A' and 'type B', can be combined. (orig.)

  4. APPLICATION OF MULTILAYER FILM CONFIGURATION TO PROTECT PHOTOMULTIPLIER AGAINST EXTERNAL STATIC MAGNETIC FIELDS

    Directory of Open Access Journals (Sweden)

    A. G. Batische

    2012-01-01

    Full Text Available The effectiveness of the screening constant magnetic field is multi-layered film screens system of NiFe/Cu, formed on the cylindrical housing of photomultiplier tubes, and compared with screen-based steel material – brand 80NHS permalloy. It is shown that the most effective is the screen on the basis of the multilayered film screens, which provide shielding effectiveness value 8–10 in magnetic fields with induction of 0,1–1 mT, and 80–100 – in magnetic fields with induction of 2–4 mT , which is 4–5 times higher than for the screen of the material 80NHS.

  5. Counting efficiency formulae for two, three or four photomultiplier systems

    International Nuclear Information System (INIS)

    Grau Malonda, A.

    1993-01-01

    Counting efficiency formulae as a function of the non-detection probability and the electron distributions for systems with two, three or dour photomultipliers are obtained in this paper. It is assumed that the photocathode electron emission follows the Poisson distribution. The obtained formulae are basic to compute the counting efficiency in liquid scintillation spectrometers

  6. Timing optimization utilizing order statistics and multichannel digital silicon photomultipliers

    NARCIS (Netherlands)

    Mandai, S.; Venialgo, E.; Charbon, E.

    2014-01-01

    We present an optimization technique utilizing order statistics with a multichannel digital silicon photomultiplier (MD-SiPM) for timing measurements. Accurate timing measurements are required by 3D rangefinding and time-of-flight positron emission tomography, to name a few applications. We have

  7. Hybrid photomultipliers - their properties and application in scintillation studies

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jiří A.; D'Ambrosio, C.

    2007-01-01

    Roč. 30, - (2007), s. 22-25 ISSN 0925-3467 Institutional research plan: CEZ:AV0Z10100521 Keywords : hybrid photodetection and photomultiplier * PIN silicon * pulse- height spectra Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.519, year: 2007

  8. Optimizing and accelerating the assignation of lineages in Mycobacterium tuberculosis using novel alternative single-tube assays.

    Directory of Open Access Journals (Sweden)

    María Carcelén

    Full Text Available The assignation of lineages in Mycobacterium tuberculosis (MTB provides valuable information for evolutionary and phylogeographic studies and makes for more accurate knowledge of the distribution of this pathogen worldwide. Differences in virulence have also been found for certain lineages. MTB isolates were initially assigned to lineages based on data obtained from genotyping techniques, such as spoligotyping or MIRU-VNTR analysis, some of which are more suitable for molecular epidemiology studies. However, since these methods are subject to a certain degree of homoplasy, other criteria have been chosen to assign lineages. These are based on targeting robust and specific SNPs for each lineage. Here, we propose two newly designed multiplex targeting methods-both of which are single-tube tests-to optimize the assignation of the six main lineages in MTB. The first method is based on ASO-PCR and offers an inexpensive and easy-to-implement assay for laboratories with limited resources. The other, which is based on SNaPshot, enables more refined standardized assignation of lineages for laboratories with better resources. Both methods performed well when assigning lineages from cultured isolates from a control panel, a test panel, and a problem panel from an unrelated population, Mexico, which included isolates in which standard genotyping was not able to classify lineages. Both tests were also able to assign lineages from stored isolates, without the need for subculture or purification of DNA, and even directly from clinical specimens with a medium-high bacilli burden. Our assays could broaden the contexts where information on lineages can be acquired, thus enabling us to quickly update data from retrospective collections and to merge data with those obtained at the time of diagnosis of a new TB case.

  9. Time-Domain Functional Diffuse Optical Tomography System Based on Fiber-Free Silicon Photomultipliers

    Directory of Open Access Journals (Sweden)

    Andrea Farina

    2017-11-01

    Full Text Available Based on recent developments in both single-photon detectors and timing electronic circuits, we designed a compact and cost effective time-domain diffuse optical tomography system operated at 1 Hz acquisition rate, based on eight silicon photomultipliers and an 8-channel time-to-digital converter. The compact detectors are directly hosted on the probe in a circular arrangement around a single light injection fiber, so to maximize light harvesting. Tomography is achieved exploiting the depth sensitivity that is encoded in the arrival time of detected photons. The system performances were evaluated on simulations to assess possible the limitations arising from the use of a single injection point, and then on phantoms and in vivo to prove the eligibility of these technologies for diffuse optical tomography.

  10. The development of a high-resolution scintillating fiber tracker with silicon photomultiplier readout

    International Nuclear Information System (INIS)

    Roper Yearwood, Gregorio

    2013-01-01

    In this work I present the design and test results for a novel, modular tracking detector from scintillating fibers which are read out by silicon photomultiplier (SiPM) arrays. The detector modules consist of 0.25 mm thin scintillating fibers which are closely packed in five-layer ribbons. Two ribbons are fixed to both sides of a carbon-fiber composite structure. Custom made SiPM arrays with a photo-detection efficiency of about 50% read out the fibers. Several 860 mm long and 32 mm wide tracker modules were tested in a secondary 12 GeV/c beam at the PS facilities, CERN in November of 2009. During this test a spatial resolution better than 0.05 mm at an average light yield of about 20 photons for a minimum ionizing particle was determined. This work details the characterization of scintillating fibers and silicon photomultipliers of different make and model. It gives an overview of the production of scintillating fiber modules. The behavior of detector modules during the test-beam is analyzed in detail and different options for the front-end electronics are compared. Furthermore, the implementation of the proposed tracking detector from scintillating fibers within the scope of the PERDaix experiment is discussed. The PERDaix detector is a permanent magnet spectrometer with a weight of 40 kg. It consists of 8 tracking detector layers from scintillating fibers, a time-of-flight detector from plastic scintillator bars with silicon photomultiplier readout and a transition radiation detector from an irregular fleece radiator and Xe/CO 2 filled proportional counting tubes. The PERDaix detector was launched with a helium balloon within the scope of the ''Balloon-Experiments for University Students'' (BEXUS) program from Kiruna, Sweden in November 2010. For a few hours PERDaix reached an altitude of 33 km and measured cosmic rays. In May 2011, the PERDaix detector was characterized during a test-beam at the PS-facilities at CERN. This work introduces methods for event

  11. Characterization of a prototype matrix of Silicon PhotoMultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Dinu, N. [Laboratory of Linear Accelerator (LAL), IN2P3-CNRS, 91898 Orsay (France)], E-mail: dinu@lal.in2p3.fr; Barrillon, P.; Bazin, C. [Laboratory of Linear Accelerator (LAL), IN2P3-CNRS, 91898 Orsay (France); Belcari, N.; Bisogni, M.G. [Universita di Pisa, Dipartimento di Fisica ' E. Fermi' , 56127 Pisa (Italy); INFN, Sezione di Pisa, 56127 Pisa (Italy); Bondil-Blin, S. [Laboratory of Linear Accelerator (LAL), IN2P3-CNRS, 91898 Orsay (France); Boscardin, M. [Fondazione Bruno Kessler (FBK-irst), 38050 Trento (Italy); Chaumat, V. [Laboratory of Linear Accelerator (LAL), IN2P3-CNRS, 91898 Orsay (France); Collazuol, G. [Scuola Normale Superiore (SNS), 56127 Pisa (Italy); INFN, Sezione di Pisa, 56127 Pisa (Italy); De La Taille, C. [Laboratory of Linear Accelerator (LAL), IN2P3-CNRS, 91898 Orsay (France); Del Guerra, A. [Universita di Pisa, Dipartimento di Fisica ' E. Fermi' , 56127 Pisa (Italy); INFN, Sezione di Pisa, 56127 Pisa (Italy); Llosa, G. [Universita di Pisa, Dipartimento di Fisica ' E. Fermi' , 56127 Pisa (Italy); Marcatili, S. [Universita di Pisa, Dipartimento di Fisica ' E. Fermi' , 56127 Pisa (Italy); INFN, Sezione di Pisa, 56127 Pisa (Italy); Melchiorri, M.; Piemonte, C. [Fondazione Bruno Kessler (FBK-irst), 38050 Trento (Italy); Puill, V. [Laboratory of Linear Accelerator (LAL), IN2P3-CNRS, 91898 Orsay (France); Tarolli, A. [Fondazione Bruno Kessler (FBK-irst), 38050 Trento (Italy); Vagnucci, J.F. [Laboratory of Linear Accelerator (LAL), IN2P3-CNRS, 91898 Orsay (France); Zorzi, N. [Fondazione Bruno Kessler (FBK-irst), 38050 Trento (Italy)

    2009-10-21

    This work reports on the electrical as well as the optical characterizations of a prototype matrix of Silicon PhotoMultipliers (SiPM). The electrical test consists of the measurement of the static (breakdown voltage, quenching resistance, post-breakdown dark current) as well as the dynamic characteristics (gain, dark count rate). The optical test consists of the estimation of the photon detection efficiency as a function of wavelength as well as operation voltage.

  12. Characterization of a prototype matrix of Silicon PhotoMultipliers

    International Nuclear Information System (INIS)

    Dinu, N.; Barrillon, P.; Bazin, C.; Belcari, N.; Bisogni, M.G.; Bondil-Blin, S.; Boscardin, M.; Chaumat, V.; Collazuol, G.; De La Taille, C.; Del Guerra, A.; Llosa, G.; Marcatili, S.; Melchiorri, M.; Piemonte, C.; Puill, V.; Tarolli, A.; Vagnucci, J.F.; Zorzi, N.

    2009-01-01

    This work reports on the electrical as well as the optical characterizations of a prototype matrix of Silicon PhotoMultipliers (SiPM). The electrical test consists of the measurement of the static (breakdown voltage, quenching resistance, post-breakdown dark current) as well as the dynamic characteristics (gain, dark count rate). The optical test consists of the estimation of the photon detection efficiency as a function of wavelength as well as operation voltage.

  13. Dynamic range broadening for photomultipliers in kinetic spectrophotometry

    International Nuclear Information System (INIS)

    Rumas, V.K.

    1983-01-01

    The circuit of switching on a photomultiplier with prestage modulation developed for kinetic spectrophotometry purposes is described. Distinguishing features of the scheme are wide range of control pulse duration (40 nc - 2.5 mc) and direct transistor photostart by laser light pulse. In the case of PM prestage modulation for the second dynode modulation depth attains 400 while PM opening time constitutes 40 nc

  14. Photocopia-A Unibody Mono-material Compact and Scalable Photomultiplier

    Energy Technology Data Exchange (ETDEWEB)

    Mulhollan, Gregory [Saxet Surface Science

    2014-12-01

    The Photocopia photomultiplier tube (PMT) takes advantage of two of the many unique properties of the hydrogenated amorphous silicon-germanium (a-SiGe) photoemitter material: its mechanical flexibility and mostly substrate-independent properties. The a-SiGe photoemitter has high secondary electron (SE) yield. It can be used both as the photocathode and as the gain medium. The active material can be grown on a flat, thin unibody substrate, formed and then “rolled up” ex situ. The completed structure would then be activated and sealed within a tube. The Ge component can be increased to enhance red-sensitivity. Compact sizes are possible, minimizing magnetic field effects. The Photocopia PMT will be a low cost alternative to MCPs for TOF detectors and provide better timing discrimination for Cherenkov detectors. Retention of the ability to activate to a normal photoyield state upon flexing (bending) the substrate of the a-SiGe material after growth, but prior to activation has been shown. The SE coefficient of the activated material has been characterized over the voltage range suitable for utilization as the gain material. The time response of the material is suited to PMT use.

  15. Single-Tube Reaction Using Perfluorocarbons: A Prerequisite Step Leading to the Whole-Slide In Situ Technique on Histopathological Slides.

    Directory of Open Access Journals (Sweden)

    Yi-Chang Chen

    Full Text Available Developing a robust, novel method for performing multiple reactions in a single tube is not only time- and cost-saving but also critical for future high-throughput whole-slide in situ techniques on diseased tissues. In this study, we introduce the use of perfluorocarbons and compound-coated magnetic particles to create pseudochambers in a single tube, allowing different reactions to be performed in different phases. Perfluorocarbons also serve as cell lysis buffer and polymerase chain reaction (PCR buffer owing to their highly penetrating, repellent and emulsifiable properties. Using this method, nucleic acids can be isolated and purified from various sample types and sizes, followed by PCR, real-time PCR, or multiplex PCR in the same tube. No incubation or enzyme digesting time is needed and the risk of cross-contamination is reduced. Tests can be performed in microemulsions (water-in-oil droplets containing sequence-specific captures and probes for further high-throughput detection. We present a simple, quick, and robust procedure as a prerequisite step to future high-throughput in situ techniques.

  16. Single atom imaging with an sCMOS camera

    Science.gov (United States)

    Picken, C. J.; Legaie, R.; Pritchard, J. D.

    2017-10-01

    Single atom imaging requires discrimination of weak photon count events above the background and has typically been performed using electron-multiplying charge-coupled device cameras, photomultiplier tubes, or single photon counting modules. A scientific complementary metal-oxide semiconductor (sCMOS) provides a cost effective and highly scalable alternative to other single atom imaging technologies, offering fast readout and larger sensor dimensions. We demonstrate single atom resolved imaging of two site-addressable optical traps separated by 10 μm using an sCMOS camera, offering a competitive signal-to-noise ratio at intermediate count rates to allow high fidelity readout discrimination (error <10-6) and sub-μm spatial resolution for applications in quantum technologies.

  17. Analytical models of probability distribution and excess noise factor of solid state photomultiplier signals with crosstalk

    International Nuclear Information System (INIS)

    Vinogradov, S.

    2012-01-01

    Silicon Photomultipliers (SiPM), also called Solid State Photomultipliers (SSPM), are based on Geiger mode avalanche breakdown that is limited by a strong negative feedback. An SSPM can detect and resolve single photons due to the high gain and ultra-low excess noise of avalanche multiplication in this mode. Crosstalk and afterpulsing processes associated with the high gain introduce specific excess noise and deteriorate the photon number resolution of the SSPM. The probabilistic features of these processes are widely studied because of its significance for the SSPM design, characterization, optimization and application, but the process modeling is mostly based on Monte Carlo simulations and numerical methods. In this study, crosstalk is considered to be a branching Poisson process, and analytical models of probability distribution and excess noise factor (ENF) of SSPM signals based on the Borel distribution as an advance on the geometric distribution models are presented and discussed. The models are found to be in a good agreement with the experimental probability distributions for dark counts and a few photon spectrums in a wide range of fired pixels number as well as with observed super-linear behavior of crosstalk ENF.

  18. Performance of CATIROC: ASIC for smart readout of large photomultiplier arrays

    Science.gov (United States)

    Blin, S.; Callier, S.; Conforti Di Lorenzo, S.; Dulucq, F.; De La Taille, C.; Martin-Chassard, G.; Seguin-Moreau, N.

    2017-03-01

    CATIROC (Charge And Time Integrated Read Out Chip) is a complete read-out chip manufactured in AustriaMicroSystem (AMS) SiGe 0.35 μm technology, designed to read arrays of 16 photomultipliers (PMTs). It is an upgraded version of PARISROC2 [1] designed in 2010 in the context of the PMm2 (square meter PhotoMultiplier) project [2]. CATIROC is a SoC (System on Chip) that processes analog signals up to the digitization and sparsification to reduce the cost and cable number. The ASIC is composed of 16 independent channels that work in triggerless mode, auto-triggering on the single photo-electron. It provides a charge measurement up to 400 photoelectrons (70 pC) on two scales of 10 bits and a timing information with an accuracy of 200 ps rms. The ASIC was sent for fabrication in February 2015 and then received in September 2015. It is a good candidate for two Chinese projects (LHAASO and JUNO). The architecture and the measurements will be detailed in the paper.

  19. Effect of Oil on the Onset of Nucleate Pool Boiling of R-124 from a Single Horizontal Tube

    Science.gov (United States)

    1993-06-01

    et al [Ref. 7] investigated the onset of nucleate boiling of R-113 under atmospheric conditions using an electrically heated 0.13 mm diameter chromel...brushing the porous surface with a soft bristle brush (i.e. toothbrush ) using ethyl alcohol and then with acetone. The tube was then allowed to air-dry

  20. Study of the photo-detection efficiency of FBK High-Density silicon photomultipliers

    International Nuclear Information System (INIS)

    Zappalà, G.; Regazzoni, V.; Acerbi, F.; Ferri, A.; Gola, A.; Paternoster, G.; Zorzi, N.; Piemonte, C.

    2016-01-01

    This work presents a study of the factors contributing to the Photo-Detection Efficiency of Silicon Photomultipliers (SiPMs): Quantum Efficiency, Triggering Probability and Fill Factor. Two different SiPM High-Density technologies are tested, NUV-HD, based on n-on-p junction, and RGB-HD, based on p-on-n junction, developed at FBK, Trento. The quantum efficiency was measured on photodiodes produced along with the SiPMs. The triggering probability, as a function of wavelength and bias voltage, was measured on circular Single Photon Avalanche Diodes (SPADs) with 100% fill factor. Square SPADs, having the same layout of single SiPM cells, were studied to measure the effective fill factor and compare it to the nominal value. The comparison of the circular and square SPADs allows to get the transition region size between the effective active area of the cell and the one defined by the layout.

  1. The new versatile general purpose surface-muon instrument (GPS) based on silicon photomultipliers for μSR measurements on a continuous-wave beam.

    Science.gov (United States)

    Amato, A; Luetkens, H; Sedlak, K; Stoykov, A; Scheuermann, R; Elender, M; Raselli, A; Graf, D

    2017-09-01

    We report on the design and commissioning of a new spectrometer for muon-spin relaxation/rotation studies installed at the Swiss Muon Source (SμS) of the Paul Scherrer Institute (PSI, Switzerland). This new instrument is essentially a new design and replaces the old general-purpose surface-muon (GPS) instrument that has been for long the workhorse of the μSR user facility at PSI. By making use of muon and positron detectors made of plastic scintillators read out by silicon photomultipliers, a time resolution of the complete instrument of about 160 ps (standard deviation) could be achieved. In addition, the absence of light guides, which are needed in traditionally built μSR instrument to deliver the scintillation light to photomultiplier tubes located outside magnetic fields applied, allowed us to design a compact instrument with a detector set covering an increased solid angle compared with the old GPS.

  2. Development and assessment of multiplex high resolution melting assay as a tool for rapid single-tube identification of five Brucella species.

    Science.gov (United States)

    Gopaul, Krishna K; Sells, Jessica; Lee, Robin; Beckstrom-Sternberg, Stephen M; Foster, Jeffrey T; Whatmore, Adrian M

    2014-12-11

    The zoonosis brucellosis causes economically significant reproductive problems in livestock and potentially debilitating disease of humans. Although the causative agent, organisms from the genus Brucella, can be differentiated into a number of species based on phenotypic characteristics, there are also significant differences in genotype that are concordant with individual species. This paper describes the development of a five target multiplex assay to identify five terrestrial Brucella species using real-time polymerase chain reaction (PCR) and subsequent high resolution melt curve analysis. This technology offers a robust and cost effective alternative to previously described hydrolysis-probe Single Nucleotide Polymorphism (SNP)-based species defining assays. Through the use of Brucella whole genome sequencing five species defining SNPs were identified. Individual HRM assays were developed to these target these changes and, following optimisation of primer concentrations, it was possible to multiplex all five assays in a single tube. In a validation exercise using a panel of 135 Brucella strains of terrestrial and marine origin, it was possible to distinguish the five target species from the other species within this panel. The HRM multiplex offers a number of diagnostic advantages over previously described SNP-based typing approaches. Further, and uniquely for HRM, the successful multiplexing of five assays in a single tube allowing differentiation of five Brucella species in the diagnostic laboratory in a cost-effective and timely manner is described. However there are possible limitations to using this platform on DNA extractions direct from clinical material.

  3. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Science.gov (United States)

    2010-04-01

    ... intubation, feeding tube, gastroenterostomy tube, Levine tube, nasogastric tube, single lumen tube with... § 876.9. (2) Class I (general controls) for the dissolvable nasogastric feed tube guide for the nasogastric tube. The class I device is exempt from the premarket notification procedures in subpart E of part...

  4. Characterization and optimization of Silicon Photomultipliers and small size scintillator tiles for future calorimeter applications

    CERN Document Server

    AUTHOR|(CDS)2095312; Horváth, Ákos

    For the active layers of highly granular sampling calorimeters, small scintillator tiles read out by Silicon Photomultipliers (SiPM) can be an interesting and cost effective alternative to silicon sensors. At CERN a test setup was realized for the development of new generations of calorimeters to characterize new types of Silicon Photomultipliers in terms of gain, noise, afterpulses and crosstalk and to study the impact of scintillator wrappings and the tile size on the measured light yield and uniformity. In this thesis work, the experimental setup is described and the steps for commissioning the equipment are discussed. Then, the temperature dependence of the Silicon Photomultiplier response will be investigated, including the dependence of bare Silicon Photomultipliers as well as Silicon Photomultipliers coupled to scintillator tiles. Finally, the tile-photomultiplier response for different tile sizes and coating options will be evaluated. The experimental setup will be extended to allow for the characteri...

  5. Study of a high gain microchannel plate photomultiplier having low statistical gain fluctuations

    International Nuclear Information System (INIS)

    Audier, M.

    1980-12-01

    A new photomultiplier configuration which synthesizes the performances of several models is proposed. The principles of microchannel plate photomultipliers are reviewed. The physical phenomena which limit the electron multiplication process in a microchannel and the detection efficiency of the microchannel plates are investigated. The operation of a herring-bone pattern device and of a system of two microchannel plate photomultipliers are described and characterized [fr

  6. Feeding Tubes

    Science.gov (United States)

    ... the TPN. Tubes Used for Enteral Feeds NG (Nasogastric Tube) A flexible tube is placed via the nose, ... portion of the small intestine Naso – nose NG – Nasogastric Tube -ostomy – new opening Percutaneous – through the skin PEJ – ...

  7. A gas proportional scintillation counter for use in large area detector systems without photomultipliers

    International Nuclear Information System (INIS)

    Baruch, J.E.F.; Brooke, G.; Kellermann, E.W.; Bateman, J.E.; Connolly, J.F.

    1978-03-01

    The properties of a prototype gas proportional scintillation detector, for use in large numbers, are examined. The detector is designed to focus a light signal, which is proportional to ionisation loss, into a fibre optic lightguide. It is shown that a single charged particle traversing the detector produces enough light out of the lightguide to be seen by a TV camera. Problems of lifetime and large scale detector production are discussed. Properties of saturation, linearity, position sensitivity, and operating limits are examined. It is shown that an array of gas proportional scintillation detectors when used with fibre optic lightguides and TV camera readout could offer significant improvements in cost per area and reliability over a scintillator plus photomultiplier or a wire proportional chamber array. (author)

  8. Study of timing performance of silicon photomultiplier and application for a Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, G.S.M., E-mail: gamal.ahmed@assoc.oeaw.ac.a [Stefan Meyer Institute, Austrian Academy of Sciences, Vienna (Austria); Al-Azhar University, Faculty of Science, Physics Department, Cairo (Egypt); Buehler, P.; Marton, J.; Suzuki, K. [Stefan Meyer Institute, Austrian Academy of Sciences, Vienna (Austria)

    2011-02-01

    Silicon photomultipliers are very versatile photo-detectors due to their high photon detection efficiency, fast response, single photon counting capability, high amplification, and their insensitivity to magnetic fields. At our institute we are studying the performance of these photo-detectors at various operating conditions. On the basis of the experience in the laboratory we built a prototype of a timing Cherenkov detector consisting of a quartz radiator with two 3x3 mm{sup 2} MPPCs S10362-33-100C from Hamamatsu Photonics as photo-detectors. The MPPC sensors were operated with Peltier cooling to minimize thermal noise and to avoid gain drifts. The test measurements at the DA {Phi} NE Beam-Test Facility (BTF) at the Laboratori Nazionali di Frascati (LNF) with pulsed 490 MeV electrons and the results on timing performance with Cherenkov photons are presented.

  9. Hybrid photomultipliers – their properties and application in scintillation studies

    CERN Document Server

    Mares, J A

    2007-01-01

    A principle of a hybrid photodetection and of a hybrid photomultiplier (HPMT) will be described. HPMT consists of a photocathode and an anode which is the silicon PIN diode. About 280 electron–hole pairs per 1 kV and up to 15 kV accelerating voltage can be used. From beginning of nineties of the last century the HPMTs are used in scintillation response studies. They show high sensitivity in the measurements of Nphels photoelectron yield starting from 20 ph/MeV (at PbWO4) without an upper limit.

  10. Digital assistance of nasogastric tube insertion in intubated patients under general anesthesia: A single-blinded prospective randomized study

    Science.gov (United States)

    Kandeel, Alrefaey; Elmorhedi, Mohammed; Abdalla, Usama

    2017-01-01

    Background: Nasogastric tube (NGT) insertion may pose a special problem in patients under general anesthesia with first attempt failure rates up to 50%. To increase insertion success rate and decreases related complications, several techniques have been developed. In this study, digital assistance technique is compared to the classic insertion technique in neck flexion. Materials and Methods: In this prospective randomized study, 160 patients were randomly allocated into two groups; control group (Group C, n = 80) where NGT tube will be inserted with the neck in flexion position and digital facilitation group (Group D, n = 80). Results: Overall success rate and first attempt success were statistically higher in Group D compared to Group C (94% vs. 81%, P = 0.02, 80% vs. 62%, P = 0.01 respectively) with significantly lower insertion time in Group D (13 ± 5 s. vs. 10 ± 3 s., P = 0.00). Conclusions: Digital assistance of NGT insertion in the anesthetized or unconscious patient is an effective, fast, and safe method that can be either used as a routine technique or as a rescue in case of failed other methods. PMID:28757827

  11. Investigating the baselines of Bismuth, Optical Fiber and LED calibrated photomultiplier tubes

    CERN Document Server

    Evans, Hywel Turner

    2016-01-01

    LUCID is a detector that is the luminosity monitor for the ATLAS experiment, and its aim is to determine luminosity with an uncertainty of a few percent. The main purpose of this work is the study of the baseline stability of the LUCID readout channels during calibration runs. This study represents the first systematic approach of this problem performed by the LUCID group. By replacing the mean baseline with the minimum baseline of each event, an upper limit of 2.85% was placed upon possible improvement in determining the LED amplitude. It is therefore better to use a fixed baseline for LED, as pollution has been observed when calculating event by event. For Bismuth and Fiber, the improvement cannot be more than the gain stability of 1%, therefore the existing method is verified as optimal.

  12. A high speed digitizing photomultiplier tube base for the KTeV CsI calorimeter

    International Nuclear Information System (INIS)

    Whitmore, J.

    1994-11-01

    A circuit has been designed to digitize PMT signals over an 18-bit dynamic range with 8-bits of resolution. The crucial element of the circuit is the custom charge integrating and encoding (QIE) ASIC. This chip is designed to operate at rates up to 53 MHz, and, in conjunction with an 8-bit FADC, generates 12-bit floating point output. Bench tests of a 17-bit version of the digital base demonstrated excellent noise performance, linearity and pedestal and gain stability. Twenty-five channels of digitizing PMT bases have been built and used for readout of a CsI array in a test beam at CERN. Performance of these devices in a beam environment is discussed

  13. Imaging technique of whole-body scintigram in the event of breakdown of the photomultiplier tube

    International Nuclear Information System (INIS)

    Inagaki, Syoichi; Tonami, Syuichi; Yasui, Masakazu; Sugishita, Kouki; Nakamura, Mamoru; Kuranishi, Makoto

    1997-01-01

    When the PMT and preamplifier are out of order, it is impossible to make a correct diagnosis because of defects on the scintigram. However, repair of the equipment may take a long time. In order to perform emergent whole-body scintigrams in the event of such breakdowns, we have developed a new approach named the lead-shield method. The major principles of this method involve placing a lead shield on the gamma camera such that it corresponds to the area of the abnormal PMT and making use of the normal area of the detector. The lead shield, 2 mm thick and 1.5 times as wide as the defect on a planar image, was situated perpendicular to the scan plane of the whole-body scintigram. The results showed that whole-body scintigrams obtained by the lead-shield method had the same quality as those obtained by the conventional method, and the spatial resolution and uniformity showed nearly no change despite some disadvantages such as lower sensitivity and shorter scan length. The lead-shield method can be a useful tool for the performance of whole-body scintigrams in cases of emergency when the PMT and preamplifier are out of order. (author)

  14. Study of various photomultiplier tubes with muon beams and Cerenkov light produced in electron showers

    International Nuclear Information System (INIS)

    2010-01-01

    The PMTs of the CMS Hadron Forward calorimeter were found to generate a large size signal when their windows were traversed by energetic charged particles. This signal, which is due to Cerenkov light production at the PMT window, could interfere with the calorimeter signal and mislead the measurements. In order to find a viable solution to this problem, the response of four different types of PMTs to muons traversing their windows at different orientations is measured at the H2 beam-line at CERN. Certain kinds of PMTs with thinner windows show significantly lower response to direct muon incidence. For the four anode PMT, a simple and powerful algorithm to identify such events and recover the PMT signal using the signals of the quadrants without window hits is also presented. For the measurement of PMT responses to Cerenkov light, the Hadron Forward calorimeter signal was mimicked by two different setups in electron beams and the PMT performances were compared with each other. Superior performance of particular PMTs was observed.

  15. Imaging technique of whole-body scintigram in the event of breakdown of the photomultiplier tube

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, Syoichi; Tonami, Syuichi; Yasui, Masakazu; Sugishita, Kouki; Nakamura, Mamoru; Kuranishi, Makoto [Toyama Medical and Pharmaceutical Univ. (Japan). Hospital

    1997-10-01

    When the PMT and preamplifier are out of order, it is impossible to make a correct diagnosis because of defects on the scintigram. However, repair of the equipment may take a long time. In order to perform emergent whole-body scintigrams in the event of such breakdowns, we have developed a new approach named the lead-shield method. The major principles of this method involve placing a lead shield on the gamma camera such that it corresponds to the area of the abnormal PMT and making use of the normal area of the detector. The lead shield, 2 mm thick and 1.5 times as wide as the defect on a planar image, was situated perpendicular to the scan plane of the whole-body scintigram. The results showed that whole-body scintigrams obtained by the lead-shield method had the same quality as those obtained by the conventional method, and the spatial resolution and uniformity showed nearly no change despite some disadvantages such as lower sensitivity and shorter scan length. The lead-shield method can be a useful tool for the performance of whole-body scintigrams in cases of emergency when the PMT and preamplifier are out of order. (author)

  16. A fast position estimation method for a control rod guide tube inspection robot with a single camera

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae C.; Seop, Jun H.; Choi, Yu R.; Kim, Jae H. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    One of the problems in the inspection of control rod guide tubes using a mobile robot is accurate estimation of the robot's position. The problem is usually explained by the question 'Where am I?'. We can solve this question by a method called dead reckoning using odometers. But it has some inherent drawbacks such that the position error grows without bound unless an independent reference is used periodically to reduce the errors. In this paper, we presented one method to overcome this drawback by using a vision sensor. Our method is based on the classical Lucas Kanade algorithm for on image tracking. In this algorithm, an optical flow must be calculated at every image frame, thus it has intensive computing load. In order to handle large motions, it is preferable to use a large integration window. But a small integration window is more preferable to keep the details contained in the images. We used the robot's movement information obtained from the dead reckoning as an input parameter for the feature tracking algorithm in order to restrict the position of an integration window. By means of this method, we could reduce the size of an integration window without any loss of its ability to handle large motions and could avoid the trade off in the accuracy. And we could estimate the position of our robot relatively fast without on intensive computing time and the inherent drawbacks mentioned above. We studied this algorithm for applying it to the control rod guide tubes inspection robot and tried an inspection without on operator's intervention.

  17. LHCb : Behaviour of Multi-anode Photomultipliers in Magnetic Fields for the LHCb RICH Upgrde

    CERN Multimedia

    Gambetta, Silvia

    2015-01-01

    A key feature of the LHCb upgrade, scheduled for 2019, is to remove the first level trigger and its data reduction from 40MHz to 1MHz, which is implemented in the on-detector readout electronics. The consequence for the LHCb Ring Imaging Cherenkov (RICH) detectors is that the Hybrid Photon Detectors need to be replaced as the readout chip is inside the detector vacuum. The baseline for replacement are Multianode Photomultiplier tubes (MaPMT) and new readout electronics. The MaPMTs will be located in the fringe field of the LHCb dipole magnet with residual fields up to 25 G. Therefore, their behaviour in magnetic fields is critical. Here we report about studies of the Hamamatsu models R11265 and H12700 in a magnetic field in an effort to qualify them for use in the LHCb RICH upgrade. Comparisons to the known model R7600 are also made. Measurements of the collection efficiency and gain were performed for all three space directions as a function of the magnetic field strength. In addition to measurements with ba...

  18. Development and characterisation of silicon photomultipliers with bulk-integrated quench resistors for future applications in particle and astroparticle physics

    International Nuclear Information System (INIS)

    Jendrysik, Christian

    2014-01-01

    This thesis deals with the development and characterisation of a novel silicon photomultiplier concept with bulk-integrated quench resistors. The approach allows the realisation of a free entrance window and high fill factors, which leads to an improvement of the detection efficiency. With first prototype productions a proof of concept was possible. A full characterisation provided promising results, in particular with respect to the photon detection efficiency. By customising the simulation tools, a reliable description of the devices was achieved. In addition, conceptual studies of the next device generation demonstrated the possibility of single cell readout, expanding the application range of those detectors to particle tracking.

  19. Time resolution of the plastic scintillator strips with matrix photomultiplier readout for J-PET tomograph

    Science.gov (United States)

    Moskal, P.; Rundel, O.; Alfs, D.; Bednarski, T.; Białas, P.; Czerwiński, E.; Gajos, A.; Giergiel, K.; Gorgol, M.; Jasińska, B.; Kamińska, D.; Kapłon, Ł.; Korcyl, G.; Kowalski, P.; Kozik, T.; Krzemień, W.; Kubicz, E.; Niedźwiecki, Sz; Pałka, M.; Raczyński, L.; Rudy, Z.; Sharma, N. G.; Słomski, A.; Silarski, M.; Strzelecki, A.; Wieczorek, A.; Wiślicki, W.; Witkowski, P.; Zieliński, M.; Zoń, N.

    2016-03-01

    Recent tests of a single module of the Jagiellonian Positron Emission Tomography system (J-PET) consisting of 30 cm long plastic scintillator strips have proven its applicability for the detection of annihilation quanta (0.511 MeV) with a coincidence resolving time (CRT) of 0.266 ns. The achieved resolution is almost by a factor of two better with respect to the current TOF-PET detectors and it can still be improved since, as it is shown in this article, the intrinsic limit of time resolution for the determination of time of the interaction of 0.511 MeV gamma quanta in plastic scintillators is much lower. As the major point of the article, a method allowing to record timestamps of several photons, at two ends of the scintillator strip, by means of matrix of silicon photomultipliers (SiPM) is introduced. As a result of simulations, conducted with the number of SiPM varying from 4 to 42, it is shown that the improvement of timing resolution saturates with the growing number of photomultipliers, and that the 2× 5 configuration at two ends allowing to read twenty timestamps, constitutes an optimal solution. The conducted simulations accounted for the emission time distribution, photon transport and absorption inside the scintillator, as well as quantum efficiency and transit time spread of photosensors, and were checked based on the experimental results. Application of the 2× 5 matrix of SiPM allows for achieving the coincidence resolving time in positron emission tomography of ≈ 0.170 ns for 15 cm axial field-of-view (AFOV) and ≈ 0.365 ns for 100 cm AFOV. The results open perspectives for construction of a cost-effective TOF-PET scanner with significantly better TOF resolution and larger AFOV with respect to the current TOF-PET modalities.

  20. Sub-aquatic response of a scintillator, fibre optic and silicon photomultiplier based radiation sensor

    International Nuclear Information System (INIS)

    Jackson, Sarah-F.; Monk, Stephen D.; Lennox, Kathryn; Stanley, Steven-J.

    2013-06-01

    We describe here, the sub-aquatic response of the RadLine R detector (a small, novel, remotely operated radiation detection instrument) when irradiated with gamma doses between 6 and 400 Svhr -1 . The National Nuclear Laboratory's (NNL, UK) RadLine R consists of an inorganic scintillating crystal coupled to a fibre optic cable which transports scintillation photons to a detector at the other end. A CCD camera is normally used for photon collection, however in this paper we trial a newer technology; the silicon photomultiplier (SiPM), namely SensL's MiniSL. SiPMs have performance characteristics similar to photomultiplier tubes (PMT), whilst benefiting from the practical advantages of solid-state technology which include; low operating voltage, robustness, compactness, insensitivity to magnetic fields and over-exposure to light. The MiniSL was chosen as its peak photon wavelength is well matched to the output from the scintillation crystal, as well as its fast recovery time (within the nano-second range). We use a clinical radiotherapy linear accelerator (linac) machine which produces x-rays by accelerating elections onto a target which then emits x-rays by Bremsstrahlung. The linac is rated at 6 MeV in energy, with a peak of approximately 2 MeV. The machine is capable of generating a highly precise dose at known distances between treatment head and scintillation crystal. Analysing the data gathered we were also able consider how the RadLine R might perform in larger aquatic environments for example First Generation Magnox Storage Ponds (FGMSP). Built in the 1950's they were originally intended to hold spent nuclear fuel for reprocessing, however now parts of the spent fuel have corroded; some of which are buried under a layer of sediment. Removal is not a trivial task due to elevated radiation levels, and the complexity of the environment. RadLine R has the potential to be of significant use for this and in other similar situations. (authors)

  1. Study of silicon photomultipliers fast amplifier and thermoregulation

    International Nuclear Information System (INIS)

    D'antone, I.; Fabbri, L.; Foschi, E.; Guandalini, C.; Laurenti, G.; Lax, I.; Levi, G.; Quadrani, L.; Sbarra, Ca.; Sbarra, Cr.; Villa, M.; Zoccoli, A.; Zuffa, M.

    2011-01-01

    The silicon photomultipliers (SiPM) are adopted in various physical applications, from medical physics to astrophysics, for their advantages in terms of cost and weight with respect to traditional photo detectors. Their low bias voltage supply (about 30 V), hardiness and resistance to magnetic field are ideal characteristics for space application. In the frame of INFN-Irst collaboration, some of them have been developed and produced at FBK (Trento-Italy), and have been characterized in the INFN laboratories of Bologna (DaSiPM2 collaboration). The SiPM can be used in conjunction with fibres and counters in high energy physics experiments. To exploit the SiPM time resolution, a fast amplifier has been studied. The SiPM gain depends critically on temperature and a thermal stabilization is also necessary. The use of a thermoelectric cooler module based on a Peltier cell has been investigated, and the results are shown.

  2. Silicon Photomultipliers in High Energy and Space Applications

    CERN Document Server

    Berra, Alessandro; Vallazza, Erik

    In recent years Silicon Photomultipliers (SiPMs) have been proposed as a new type of readout system for scintillating detectors in many experiments. SiPMs consist of a matrix of parallel-connected silicon micro-pixels, which are independent photon counters working in limited Geiger mode with very high gain. The goal of this thesis work is to describe the use of SiPMs as a readout system for plastic scintillators, both for tracking and calorimetry purposes. Different prototypes of scintillating bar tracker and shashlik calorimeters have been tested at CERN on the PS and SPS extracted beamlines. All the tests have been performed in the framework of the FACTOR (Fiber Apparatus for Calorimetry and Tracking with Optoelectronic Read-out) collaboration, a three year R&D project started in 2007 and funded by the Italian Institute of Nuclear Physics (INFN).

  3. A study of timing properties of Silicon Photomultipliers

    Science.gov (United States)

    Avella, Paola; De Santo, Antonella; Lohstroh, Annika; Sajjad, Muhammad T.; Sellin, Paul J.

    2012-12-01

    Silicon Photomultipliers (SiPMs) are solid-state pixelated photodetectors. Lately these sensors have been investigated for Time of Flight Positron Emission Tomography (ToF-PET) applications, where very good coincidence time resolution of the order of hundreds of picoseconds imply spatial resolution of the order of cm in the image reconstruction. The very fast rise time typical of the avalanche discharge improves the time resolution, but can be limited by the readout electronics and the technology used to construct the device. In this work the parameters of the equivalent circuit of the device that directly affect the pulse shape, namely the quenching resistance and capacitance and the diode and parasitic capacitances, were calculated. The mean rise time obtained with different preamplifiers was also measured.

  4. Characterization of silicon photomultipliers and validation of the electrical model

    Science.gov (United States)

    Peng, Peng; Qiang, Yi; Ross, Steve; Burr, Kent

    2018-04-01

    This paper introduces a systematic way to measure most features of the silicon photomultipliers (SiPM). We implement an efficient two-laser procedure to measure the recovery time. Avalanche probability was found to play an important role in explaining the right behavior of the SiPM recovery process. Also, we demonstrate how equivalent circuit parameters measured by optical tests can be used in SPICE modeling to predict details of the time constants relevant to the pulse shape. The SiPM properties measured include breakdown voltage, gain, diode capacitor, quench resistor, quench capacitor, dark count rate, photodetection efficiency, cross-talk and after-pulsing probability, and recovery time. We apply these techniques on the SiPMs from two companies: Hamamatsu and SensL.

  5. Study of silicon photomultipliers fast amplifier and thermoregulation

    Energy Technology Data Exchange (ETDEWEB)

    D' antone, I. [INFN of Bologna, Viale B.Pichat 4/2, 40127 Bologna (Italy); Fabbri, L.; Foschi, E. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Guandalini, C.; Laurenti, G.; Lax, I. [INFN of Bologna, Viale B.Pichat 4/2, 40127 Bologna (Italy); Levi, G.; Quadrani, L.; Sbarra, Ca. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Sbarra, Cr., E-mail: cristina.sbarra@bo.infn.i [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Villa, M.; Zoccoli, A. [Department of Physics and INFN, Viale B.Pichat 4/2, 40127 Bologna (Italy); Zuffa, M. [INFN of Bologna, Viale B.Pichat 4/2, 40127 Bologna (Italy)

    2011-02-21

    The silicon photomultipliers (SiPM) are adopted in various physical applications, from medical physics to astrophysics, for their advantages in terms of cost and weight with respect to traditional photo detectors. Their low bias voltage supply (about 30 V), hardiness and resistance to magnetic field are ideal characteristics for space application. In the frame of INFN-Irst collaboration, some of them have been developed and produced at FBK (Trento-Italy), and have been characterized in the INFN laboratories of Bologna (DaSiPM2 collaboration). The SiPM can be used in conjunction with fibres and counters in high energy physics experiments. To exploit the SiPM time resolution, a fast amplifier has been studied. The SiPM gain depends critically on temperature and a thermal stabilization is also necessary. The use of a thermoelectric cooler module based on a Peltier cell has been investigated, and the results are shown.

  6. Precise method for determining avalanche breakdown voltage of silicon photomultipliers

    Science.gov (United States)

    Chirikov-Zorin, I.

    2017-07-01

    A physically motivated method is proposed for determining the avalanche breakdown voltage of silicon photomultipliers (SiPM). The method is based on measuring the dependence of the relative photon detection efficiency (PDErel) on the bias voltage when one type of carriers (electron or hole) is injected into the avalanche multiplication zone of the p-n junction. The injection of electrons or holes from the base region of the SiPM semiconductor structure is performed using short-wave or long-wave light. At a low overvoltage (1-2 V) the detection efficiency is linearly dependent on the bias voltage; therefore, extrapolation to zero PDErel value determines the SiPM avalanche breakdown voltage with an accuracy within a few millivolts.

  7. Electronic setup for fluorescence emission measurements and long-time constant-temperature maintenance of Single-Walled Carbon Nano-Tubes in water solutions

    Directory of Open Access Journals (Sweden)

    De Rosa Matteo

    2017-03-01

    Full Text Available In our previous research we have observed that the fluorescence emission from water solutions of Single-Walled Carbon Nano-Tubes (SWCNT, excited by a laser with a wavelength of 830nm, diminishes with the time. We have already proved that such a fading is a function of the storage time and the storage temperature. In order to study the emission of the SWCNT as a function of these two parameters we have designed and realized a special measurement compartment with a cuvette holder where the SWCNT solutions can be measured and stored at a fixed constant temperature for periods of time as long as several weeks. To maintain the measurement setup under a constant temperature we have designed special experimental setup based on two Peltier cells with electronic temperature control.

  8. Multi-anode wire straw tube tracker

    International Nuclear Information System (INIS)

    Oh, S.H.; Ebenstein, W.L.; Wang, C.W.

    2011-01-01

    We report on a test of a straw tube detector design having several anode (sense) wires inside a straw tube. The anode wires form a circle inside the tube and are read out independently. This design could solve several shortcomings of the traditional single wire straw tube design such as double hit capability and stereo configuration.

  9. 21 CFR 872.6570 - Impression tube.

    Science.gov (United States)

    2010-04-01

    ... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6570 Impression tube. (a) Identification. An impression tube is a device consisting of a hollow copper tube intended to take an impression of a single tooth... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Impression tube. 872.6570 Section 872.6570 Food...

  10. Advances in single- and multi-stage Stirling-type pulse tube cryocoolers for space applications in NLIP/SITP/CAS

    Science.gov (United States)

    Dang, Haizheng; Tan, Jun; Zha, Rui; Li, Jiaqi; Zhang, Lei; Zhao, Yibo; Gao, Zhiqian; Bao, Dingli; Li, Ning; Zhang, Tao; Zhao, Yongjiang; Zhao, Bangjian

    2017-12-01

    This paper presents a review of recent advances in single- and multi-stage Stirling-type pulse tube cryocoolers (SPTCs) for space applications developed at the National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences (NLIP/SITP/CAS). A variety of single-stage SPTCs operating at 25-150 K have been developed, including several mid-sized ones operating at 80-110 K. Significant progress has been achieved in coolers operating at 30-40 K which use common stainless steel meshes as regenerator matrices. Another important advance is the micro SPTCs with an overall mass of 300-800 g operating at high frequencies varying from 100 Hz to 400 Hz. The main purpose of developing two-stage SPTCs is to simultaneously acquire cooling capacities at both stages, obviating the need for auxiliary precooling in various applications. The three-stage SPTCs are developed mainly for applications at around 10 K, which are also used for precooling the J-T coolers to achieve further lower temperatures. The four-stage SPTCs are developed to directly achieve the liquid helium temperature for cooling space low-Tc superconducting devices and for the deep space exploration as well. Several typical development programs are described and an overview of the cooler performances is presented.

  11. Evaluation of single crystal LaB6 cathodes for use in a high frequency backward wave oscillator tube

    Science.gov (United States)

    Swanson, L. W.; Davis, P. R.; Schwind, G. A.

    1984-01-01

    The results of thermionic emission and evaporation studies of single crystal LaB6 cathodes are given. A comparison between the (100), (210) and (310) crystal planes shows the (310) and (210) planes to possess a work function approx 0.2 eV lower than (100). This translates into a significant increase in current density, J, at a specified temperature. Comparison with a state-of-the-art impregnated dispenser cathode shows that LaB6 (310) is a superior cathode in nearly all respects except operating temperature at j 10 A/sq cm. The 1600 K thermionic and room temperature retarding potential work functions for LaB6 (310) are 2.42 and 2.50 respectively.

  12. A robust and semi-automatic procedure for Silicon Photomultipliers characterisation

    Science.gov (United States)

    Arosio, V.; Beretta, M.; Caccia, M.; Santoro, R.

    2017-03-01

    Silicon Photomultipliers are state-of-the-art solid state sensors of light with single photon sensitivity, unprecedented photon number resolving capability and high photon detection efficiency. SiPM are cost effective, compact, magnetic field insensitive and with an extreme flexibility in the design to cope with different applications in fundamental and applied science and industry. As a rapidly evolving technology, new generation of sensors are being continuously proposed by different producers, requiring the development of reliable and efficient SiPM characterisation methods to perform a quick assessment and comparison. The procedure presented here is based on post-processing of digitised SiPM waveforms recording the response of the sensor to an ultra-fast light pulse. For every pulse, the signal is synchronously sampled, digitised and recorded on the timescale of a few microseconds with the objective of extracting from a single set of waveforms a full picture of the sensor characteristics in terms of Gain, Breakdown Voltage, Dark Count Rate , Optical Cross-Talk and After Pulse probability. The need of a unique and consistent data-set guarantees a fast and robust characterisation, stable against environmental condition changes, notably temperature.

  13. Radiation-resistant camera tube

    International Nuclear Information System (INIS)

    Kuwahata, Takao; Manabe, Sohei; Makishima, Yasuhiro

    1982-01-01

    It was a long time ago that Toshiba launched on manufacturing black-and-white radiation-resistant camera tubes employing nonbrowning face-plate glass for ITV cameras used in nuclear power plants. Now in compliance with the increasing demand in nuclear power field, the Company is at grips with the development of radiation-resistant single color-camera tubes incorporating a color-stripe filter for color ITV cameras used under radiation environment. Herein represented are the results of experiments on characteristics of materials for single color-camera tubes and prospects for commercialization of the tubes. (author)

  14. Simultaneous detection of five notifiable viral diseases of cattle by single-tube multiplex real-time RT-PCR.

    Science.gov (United States)

    Wernike, Kerstin; Hoffmann, Bernd; Beer, Martin

    2015-06-01

    Multiplexed real-time PCR (qPCR) assays enable the detection of several target genes in a single reaction, which is applicable for simultaneous testing for the most important viral diseases in samples obtained from ruminants with unspecific clinical symptoms. Here, reverse transcription qPCR (RT-qPCR) systems for the detection of bovine viral diarrhoea virus (BVDV) and bluetongue virus (BTV) were combined with an internal control system based on the beta-actin gene. Additionally, a background screening for three further major pathogens of cloven-hoofed animals reportable to the World Organisation for Animal Health, namely foot-and-mouth disease virus, epizootic haemorrhagic disease virus, and Rift Valley fever virus, was integrated using the identical fluorophore for the respective RT-qPCR assays. Every pathogen-specific assay had an analytical sensitivity of at least 100 genome copies per reaction within the multiplex approach, and a series of reference samples and clinical specimens obtained from cattle, but also from small ruminants, were detected reliably. The qPCR systems integrated in the background screening were even not influenced by the simultaneous amplification of very high BVDV and BTV genome copy numbers. The newly developed multiplex qPCR allows the specific and sensitive detection of five of the most important diseases of ruminants and could be used in the context of monitoring programs or for differential diagnostics. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. PENGARUH SUHU DAN LAMA PROSES SULFONASI DALAM PROSES PRODUKSI METHYL ESTER SULFONIC ACID (MESA MENGGUNAKAN SINGLE TUBE FALLING FILM REACTOR (STFR

    Directory of Open Access Journals (Sweden)

    Siti Mujdalipah

    2013-03-01

    Full Text Available Effects of Temperature and Sulfonation Time on Methyl Ester Sulfonic Acid (MESA Production Process usingSingle Tube Falling Film Reactor (STFR Siti Mujdalipah, Erliza Hambali, Ani Suryani, Edi Zulchaidir ABSTRAK Methyl Ester Sulfonic Acid (MESA merupakan produk antara dari surfaktan Metil Ester Sulfonat (MES. MESmemiliki beragam aplikasi dalam produk personal care, pencuci dan pembersih, dan untuk Enhanced Oil Recovery(EOR. Proses produksi MESA menggunakan gas SO3 dalam Single Tube Falling Film Reactor (STFR merupakanteknologi yang umum digunakan. Kajian ini bertujuan untuk mendapatkan kondisi proses sulfonasi metil ester oleinterbaik menggunakan gas SO3 dalam STFR. Kajian dilakukan dalam tiga tahap, yaitu tahap penelitian, tahap analisis,dan tahap pengolahan data. Tahap produksi MESA terdiri dari pembuatan metil ester (ME dari olein minyak sawit dankajian pengaruh suhu dan lama proses sulfonasi. Tahap analisis meliputi analisis sifat Þ siko kimia olein minyak sawit,analisa sifat Þ siko kimia ME olein sawit, dan analisis sifat Þ siko kimia MESA olein sawit. Kajian pengaruh suhu danlama proses sulfonasi terhadap proses sulfonasi metil ester olein terdiri dari suhu 70, 90, dan 110 oC dan lama prosessulfonasi 30, 60, dan 90 menit. Analisis varian pada !=0,01 menunjukan bahwa lama proses sulfonasi berpengaruh nyataterhadap kadar bahan aktif. Analisis varian pada !=0,01 juga menunjukan bahwa lama proses sulfonasi berpengaruhnyata terhadap nilai pH, bilangan asam, bilangan iod, dan kemampuan MESA dalam menurunkan tegangan antarmuka(IFT, Interfacial Tension antara air formasi dan minyak bumi. Proses sulfonasi terbaik dicapai pada suhu sulfonasi 90oCdan lama proses sulfonasi 90 menit. Kondisi proses sulfonasi terbaik dapat menghasilkan MESA dengan karakteristikkadar bahan aktif 31,44%, pH 2,66, bilangan asam 24,88 ml NaOH/g sampel, bilangan iod 11,95 mg I/g sampel, danmemiliki kemampuan menurunkan IFT antara air formasi dan minyak bumi dari 30 dyne

  16. Single-Tube Dodecaplex PCR Panel of Polymorphic Microsatellite Markers Closely Linked to theDMPKCTG Repeat for Preimplantation Genetic Diagnosis of Myotonic Dystrophy Type 1.

    Science.gov (United States)

    Lian, Mulias; Zhao, Mingjue; Lee, Caroline G; Chong, Samuel S

    2017-06-01

    Preimplantation genetic diagnosis (PGD) of myotonic dystrophy type 1 (DM1) currently uses conventional PCR to detect nonexpanded dystrophia myotonica protein kinase ( DMPK ) alleles or triplet-primed PCR to detect the CTG-expanded alleles, coupled with analysis of linked microsatellite markers to increase diagnostic accuracy. We aimed to simplify the process of identification and selection of informative linked markers for application to DM1 PGD. An in silico search was performed to identify all markers within 1-1.5 Mb flanking the DMPK gene. Five previously known (D19S559, APOC2, D19S543, D19S112, and BV209569) and 7 novel (DM45050, DM45178, DM45209, DM45958, DM46513, DM46892, and DM47004.1) markers with potentially high heterozygosity values and polymorphism information content were selected and optimized in a single-tube multiplex PCR panel. Analysis of 184 DNA samples of Chinese and Caucasian individuals (91 from unrelated, anonymized cord blood of Chinese babies born at the National University Hospital, Singapore, and 93 Caucasian DNA samples from the Human Variation Panel HD100CAU) confirmed the high polymorphism indices of all markers (polymorphism information content >0.5), with observed heterozygosity values ranging from 0.62-0.93. All individuals were heterozygous for at least 6 markers, with 99.5% of individuals heterozygous for at least 2 markers on either side of the DMPK CTG repeat. The dodecaplex marker assay was successfully validated on 42 single cells and 12 whole genome amplified single cells. The DM1 multiplex PCR panel is suitable for use in DM1 PGD either as a standalone linkage-based assay or as a complement to DMPK CTG repeat expansion-mutation detection. © 2017 American Association for Clinical Chemistry.

  17. Study of the radiation damage of silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Nitschke, Michael; Chmill, Valery; Garutti, Erika; Klanner, Robert; Schwandt, Joern [Institute for Experimental Physics, Hamburg University, Luruper Chaussee 149, D-22761 Hamburg (Germany)

    2016-07-01

    Radiation damage significantly changes the performance of silicon photomultipliers (SiPM). In this work, we first have characterized KETEK SiPMs with a pixel size of 15 x 15 μm{sup 2} using I-V (current-voltage), C/G-V/f (capacitance/impedance-voltage/frequency) and Q-V (charge-voltage) measurements with and without illumination with blue light of 470 nm from an LED. The SiPM parameters determined are DCR (dark count rate), relative PDE (photon detection efficiency), G (Gain), XT (cross-talk), Geiger breakdown characteristics, C{sub pix} (pixel capacitance) and R{sub q} (quenching resistance). Following this first characterization, the SiPMs were irradiated using reactor neutrons with fluences of 10{sup 9}, 10{sup 10}, 10{sup 11}, 5 . 10{sup 11}, and 10{sup 12} n/cm{sup 2}. Afterwards, the same measurements were repeated, and the dependence of the SiPM parameters on neutron fluence was determined. The results are used to optimize the radiation tolerance of SiPMs.

  18. Silicon photomultipliers. Properties and applications in a highly granular calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Feege, Nils

    2008-12-15

    Silicon Photomultipliers (SiPMs) are novel semiconductor-based photodetectors operated in Geiger mode. Their response is not linear, and both their gain and their photon detection efficiency depend on the applied bias voltage and on temperature. The CALICE collaboration investigates several technology options for highly granular calorimeters for the future ILC. The prototype of a scintillator-steel sampling calorimeter with analogue readout for hadrons constructed at DESY and successfully operated in testbeam experiments at DESY, CERN and FNAL by this collaboration is the first large scale application for 7608 SiPMs developed by MEPhI. This thesis deals with properties of the SiPMs used in the calorimeter prototype. The effective numer of pixels of the SiPMs, which influences their saturation behaviour, is extracted from in situ measurements and compared to results obtained for the bare SiPMs. In addition, the effects of temperature and voltage changes on the parameters necessary for the calibration of the SiPMs and the detector are determined. Methods which allow for correcting or compensating these effects are evaluated. An approach to improve the absolute calibration of the temperature sensors in the prototype is described and temperature profiles are studied. Finally, a procedure to adjust the light yield of the cells of the prototype is presented. The results of the application of this procedure during the commissioning of the detector at FNAL are discussed. (orig.)

  19. Kinetics of the Thermal Decomposition of Tetramethylsilane behind the Reflected Shock Waves in a Single Pulse Shock Tube (SPST) and Modeling Study

    Science.gov (United States)

    Parandaman, A.; Sudhakar, G.; Rajakumar, B.

    Thermal reactions of Tetramethylsilane (TMS) diluted in argon were studied behind the reflected shock waves in a single-pulse shock tube (SPST) over the temperature range of 1085-1221 K and pressures varied between 10.6 and 22.8 atm. The stable products resulting from the decomposition of TMS were identified and quantified using gas chromatography and also verified with Fourier Transform Infrared (FTIR) spectrometer. The major reaction products are methane (CH4) and ethylene (C2H4). The minor reaction products are ethane (C2H6) and propylene (C3H6). The initiation of mechanism in the decomposition of TMS takes plays via the Si-C bond scission by ejecting the methyl radicals (CH3) and trimethylsilyl radicals ((CH3)3Si). The measured temperature dependent rate coefficient for the total decomposition of TMS was to be ktotal = 1.66 ×1015 exp (-64.46/RT) s-1 and for the formation of CH4 reaction channel was to be k = 2.20 × 1014 exp (-60.15/RT) s-1, where the activation energies are given in kcal mol-1. A kinetic scheme containing 17 species and 28 elementary reactions was used for the simulation using chemical kinetic simulator over the temperature range of 1085-1221 K. The agreement between the experimental and simulated results was satisfactory.

  20. A novel and highly sensitive real-time nested RT-PCR assay in a single closed tube for detection of enterovirus.

    Science.gov (United States)

    Shen, Xin-Xin; Qiu, Fang-Zhou; Zhao, Huai-Long; Yang, Meng-Jie; Hong, Liu; Xu, Song-Tao; Zhou, Shuai-Feng; Li, Gui-Xia; Feng, Zhi-Shan; Ma, Xue-Jun

    2018-03-01

    The sensitivity of qRT-PCR assay is not adequate for the detection of the samples with lower viral load, particularly in the cerebrospinal fluid (CSF) of patients. Here, we present the development of a highly sensitive real-time nested RT-PCR (RTN RT-PCR) assay in a single closed tube for detection of human enterovirus (HEV). The clinical performance of both RTN RT-PCR and qRT-PCR was also tested and compared using 140 CSF and fecal specimens. The sensitivities of RTN RT-PCR assay for EV71, Coxsackievirus A (CVA)16, CVA6 and CVA10 achieved 10 -8 dilution with a corresponding Ct value of 38.20, 36.45, 36.75, and 36.45, respectively, which is equal to traditional two-step nested RT-PCR assay and approximately 2-10-fold lower than that of qRT-PCR assay. The specificity of RTN RT-PCR assay was extensively analyzed insilico and subsequently verified using the reference isolates and clinical samples. Sixteen qRT-PCR-negative samples were detected by RTN RT-PCR and a variety of enterovirus serotypes was identified by sequencing of inner PCR products. We conclude RTN RT-PCR is more sensitive than qRT-PCR for the detection of HEV in clinical samples. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Effect of using a laryngeal tube on the no-flow time in a simulated, single-rescuer, basic life support setting with inexperienced users.

    Science.gov (United States)

    Meyer, O; Bucher, M; Schröder, J

    2016-03-01

    The laryngeal tube (LT) is a recommended alternative to endotracheal intubation during advanced life support (ALS). Its insertion is relatively simple; therefore, it may also serve as an alternative to bag mask ventilation (BMV) for untrained personnel performing basic life support (BLS). Data support the influence of LT on the no-flow time (NFT) compared with BMV during ALS in manikin studies. We performed a manikin study to investigate the effect of using the LT for ventilation instead of BMV on the NFT during BLS in a prospective, randomized, single-rescuer study. All 209 participants were trained in BMV, but were inexperienced in using LT; each participant performed BLS during a 4-min time period. No significant difference in total NFT (LT: mean 81.1 ± 22.7 s; BMV: mean 83.2 ± 13.1 s, p = 0.414) was found; however, significant differences in the later periods of the scenario were identified. While ventilating with the LT, the proportion of chest compressions increased significantly from 67.2 to 73.2%, whereas the proportion of chest compressions increased only marginally when performing BMV. The quality of the chest compressions and the associated ventilation rate did not differ significantly. The mean tidal volume and mean minute volume were significantly lower when performing BMV. The NFT was significantly shorter in the later periods in a single-rescuer, cardiac arrest scenario when using an LT without previous training compared with BMV with previous training. A possible explanation for this result may be the complexity and workload of alternating tasks (e.g., time loss when reclining the head and positioning the mask for each ventilation during BMV).

  2. A design of a valid signal selecting and position decoding ASIC for PET using silicon photomultipliers

    Science.gov (United States)

    Cho, M.; Lim, K.-t.; Kim, H.; Yeom, J.-y.; Kim, J.; Lee, C.; Choi, H.; Cho, G.

    2017-01-01

    In most cases, a PET system has numerous electrical components and channel circuits and thus it would rather be a bulky product. Also, most existing systems receive analog signals from detectors which make them vulnerable to signal distortions. For these reasons, channel reduction techniques are important. In this work, an ASIC for PET module is being proposed. An ASIC chip for 16 PET detector channels, VSSPDC, has been designed and simulated. The main function of the chip is 16-to-1 channel reduction, i.e., finding the position of only the valid signals, signal timing, and magnitudes in all 16 channels at every recorded event. The ASIC comprises four of 4-channel modules and a 2nd 4-to-1 router. A single channel module comprises a transimpedance amplifier for the silicon photomultipliers, dual comparators with high and low level references, and a logic circuitry. While the high level reference was used to test the validity of the signal, the low level reference was used for the timing. The 1-channel module of the ASIC produced an energy pulse by time-over-threshold method and it also produced a time pulse with a fixed delayed time. Since the ASIC chip outputs only a few digital pulses and does not require an external clock, it has an advantage over noise properties. The cadence simulation showed the good performance of the chip as designed.

  3. An innovative silicon photomultiplier digitizing camera for gamma-ray astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Heller, M. [DPNC-Universite de Geneve, Geneva (Switzerland); Schioppa, E. Jr; Porcelli, A.; Pujadas, I.T.; Della Volpe, D.; Montaruli, T.; Cadoux, F.; Favre, Y.; Christov, A.; Rameez, M.; Miranda, L.D.M. [DPNC-Universite de Geneve, Geneva (Switzerland); Zietara, K.; Idzkowski, B.; Jamrozy, M.; Ostrowski, M.; Stawarz, L.; Zagdanski, A. [Jagellonian University, Astronomical Observatory, Krakow (Poland); Aguilar, J.A. [DPNC-Universite de Geneve, Geneva (Switzerland); Universite Libre Bruxelles, Faculte des Sciences, Brussels (Belgium); Prandini, E.; Lyard, E.; Neronov, A.; Walter, R. [Universite de Geneve, Department of Astronomy, Geneva (Switzerland); Rajda, P.; Bilnik, W.; Kasperek, J.; Lalik, K.; Wiecek, M. [AGH University of Science and Technology, Krakow (Poland); Blocki, J.; Mach, E.; Michalowski, J.; Niemiec, J.; Skowron, K.; Stodulski, M. [Instytut Fizyki Jadrowej im. H. Niewodniczanskiego Polskiej Akademii Nauk, Krakow (Poland); Bogacz, L. [Jagiellonian University, Department of Information Technologies, Krakow (Poland); Borkowski, J.; Frankowski, A.; Janiak, M.; Moderski, R. [Polish Academy of Science, Nicolaus Copernicus Astronomical Center, Warsaw (Poland); Bulik, T.; Grudzinska, M. [University of Warsaw, Astronomical Observatory, Warsaw (Poland); Mandat, D.; Pech, M.; Schovanek, P. [Institute of Physics of the Czech Academy of Sciences, Prague (Czech Republic); Marszalek, A.; Stodulska, M. [Instytut Fizyki Jadrowej im. H. Niewodniczanskiego Polskiej Akademii Nauk, Krakow (Poland); Jagellonian University, Astronomical Observatory, Krakow (Poland); Pasko, P.; Seweryn, K. [Centrum Badan Kosmicznych Polskiej Akademii Nauk, Warsaw (Poland); Sliusar, V. [Universite de Geneve, Department of Astronomy, Geneva (Switzerland); Taras Shevchenko National University of Kyiv, Astronomical Observatory, Kyiv (Ukraine)

    2017-01-15

    The single-mirror small-size telescope (SST-1M) is one of the three proposed designs for the small-size telescopes (SSTs) of the Cherenkov Telescope Array (CTA) project. The SST-1M will be equipped with a 4 m-diameter segmented reflector dish and an innovative fully digital camera based on silicon photo-multipliers. Since the SST sub-array will consist of up to 70 telescopes, the challenge is not only to build telescopes with excellent performance, but also to design them so that their components can be commissioned, assembled and tested by industry. In this paper we review the basic steps that led to the design concepts for the SST-1M camera and the ongoing realization of the first prototype, with focus on the innovative solutions adopted for the photodetector plane and the readout and trigger parts of the camera. In addition, we report on results of laboratory measurements on real scale elements that validate the camera design and show that it is capable of matching the CTA requirements of operating up to high moonlight background conditions. (orig.)

  4. Performance study of Philips digital silicon photomultiplier coupled to scintillating crystals

    CERN Document Server

    Liu, Z.; Auffray, E.; Lecoq, P.; Paganoni, M.

    2016-01-01

    Silicon photomultipliers (SiPMs) and scintillators are often arranged in the shape of arrays in Positron Emission Tomography (PET) systems. Digital SiPMs provide signal readout in single photon avalanche diode (SPAD) level. From the photon count rate measurement of each SPAD cell of digital SiPM, we found that the output scintillating photons distribute in an area larger than the scintillator physical coupling area. Taking advantage of the possibility to enable/disable individual cells of the digital SiPM, a group of Lutetium-yttrium oxyorthosilicate (LYSO) crystals with different dimensions coupled to a digital SiPM was used to study the influence of using different SiPM active area on the number of photons detected, energy resolution and coincidence time resolution (CTR). For the same crystal coupled to the digital SiPM, the larger the active area of digital SiPM, the higher the number of photons detected. The larger active area of the digital SiPM also results in a better energy resolution after saturation...

  5. A design of a valid signal selecting and position decoding ASIC for PET using silicon photomultipliers

    International Nuclear Information System (INIS)

    Cho, M.; Lim, K.-T.; Kim, J.; Lee, C.; Cho, G.; Kim, H.; Yeom, J.-Y.; Choi, H.

    2017-01-01

    In most cases, a PET system has numerous electrical components and channel circuits and thus it would rather be a bulky product. Also, most existing systems receive analog signals from detectors which make them vulnerable to signal distortions. For these reasons, channel reduction techniques are important. In this work, an ASIC for PET module is being proposed. An ASIC chip for 16 PET detector channels, VSSPDC, has been designed and simulated. The main function of the chip is 16-to-1 channel reduction, i.e., finding the position of only the valid signals, signal timing, and magnitudes in all 16 channels at every recorded event. The ASIC comprises four of 4-channel modules and a 2 nd 4-to-1 router. A single channel module comprises a transimpedance amplifier for the silicon photomultipliers, dual comparators with high and low level references, and a logic circuitry. While the high level reference was used to test the validity of the signal, the low level reference was used for the timing. The 1-channel module of the ASIC produced an energy pulse by time-over-threshold method and it also produced a time pulse with a fixed delayed time. Since the ASIC chip outputs only a few digital pulses and does not require an external clock, it has an advantage over noise properties. The cadence simulation showed the good performance of the chip as designed.

  6. Performance evaluation of neuro-PET using silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jiwoong; Choi, Yong, E-mail: ychoi@sogang.ac.kr; Jung, Jin Ho, E-mail: jinho1115@gmail.com; Kim, Sangsu; Im, Ki Chun

    2016-05-21

    Recently, we have developed the second prototype Silicon photomultiplier (SiPM) based positron emission tomography (PET) scanner for human brain imaging. The PET system was comprised of detector block which consisted of 4×4 SiPMs and 4×4 Lutetium Yttrium Orthosilicate arrays, charge signal transmission method, high density position decoder circuit and FPGA-embedded ADC boards. The purpose of this study was to evaluate the performance of the newly developed neuro-PET system. The energy resolution, timing resolution, spatial resolution, sensitivity, stability of the photo-peak position and count rate performance were measured. Tomographic image of 3D Hoffman brain phantom was also acquired to evaluate imaging capability of the neuro-PET. The average energy and timing resolutions measured for 511 keV gamma rays were 17±0.1% and 3±0.3 ns, respectively. Spatial resolution and sensitivity at the center of field of view (FOV) were 3.1 mm and 0.8%, respectively. The average scatter fraction was 0.4 with an energy window of 350–650 keV. The maximum true count rate and maximum NECR were measured as 43.3 kcps and 6.5 kcps at an activity concentration of 16.7 kBq/ml and 5.5 kBq/ml, respectively. Long-term stability results show that there was no significant change in the photo-peak position, energy resolution and count rate for 60 days. Phantom imaging studies were performed and they demonstrated the feasibility for high quality brain imaging. The performance tests and imaging results indicate that the newly developed PET is useful for brain imaging studies, if the axial FOV is extended to improve the system sensitivity.

  7. Silicon photomultiplier modules for MRI-compatible PET

    Science.gov (United States)

    Sul, Woo-Suk; Kim, Hyoungtaek; Cho, Gyuseong

    2015-04-01

    Silicon photomultiplier (SiPM) modules were developed for use in positron emission tomography-magnetic resonance imaging (PET-MRI), which is a hybrid medical imaging technology. A PET-MRI is very efficient in the early diagnosis of representative senile diseases, including cancer, Alzheimer's disease, and Parkinson's disease. SiPMs comprise the core image sensor for MR-compatible PET applications since they have a low operational voltage, high gain, good timing resolution, ruggedness, insensitivity to magnetic fields, compactness, and low cost. In PET systems, SiPM microcells can be optimized by making a trade-off between photon detection efficiency (PDE) and dynamic range. The SiPM modules used in this study were fabricated at the National NanoFab Center (NNFC) of South Korea by using a customized CMOS processes. The SiPM modules were evaluated by first packaging them with a cost-effective PCB package instead of with a conventional ceramic package. Measurements on 1,400 SiPMs indicated a uniform breakdown voltage of 20.54 V with a standard deviation of 0.07 V. Moreover, the SiPM modules present a high and uniform energy resolution of 13.6% with a standard deviation of 0.5% at 511 keV with 3 × 3 × 20 mm3 cerium-doped lutetium-yttrium oxyorthosilicate (Lu2(1-x)Y2xSiO5:Ce, LYSO) crystal coupling. These results indicated that the proposed devices offer adequate performance to form the foundation of an image sensor technology for MRI-compatible PET.

  8. Building lab-scale x-ray tube based irradiators

    Science.gov (United States)

    The construction of economical x-ray tube based irradiators in a variety of configurations is described using 1000 Watt x-ray tubes. Single tube, double tube, and four tube designs are described, as well as various cabinet construction techniques. Relatively high dose rates were achieved for small s...

  9. Scintillation of lead tungstate crystal studied with single-electron beam from KUFEL

    Energy Technology Data Exchange (ETDEWEB)

    Rizwan, Mohamad, E-mail: rizwan@nucl.kyushu-u.ac.jp; Uozumi, Yusuke; Matsuo, Kazuki [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka (Japan); Ohgaki, Hideaki; Kii, Toshiteru; Zen, Heishun [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto (Japan); Tsamalaidze, Zviadi; Evtoukhovitch, Petr; Valentin, Samoilov [Joint Institute for Nuclear Research, JINR, Joliot-Curie Str.6, Dubna (Russian Federation)

    2015-04-29

    Lead tungstate (PWO) crystal has a very fast response, high atomic density and high radiation hardness. Therefore, they are suitable to be used for high-energy nuclear data measurements under high-background circumstances. Although a good electron-ion separation with a pulse shape analysis technique is essential, scintillation pulse shapes have not been observed with electron beams of a wide energy range. A single-electron beam technique has been developed at Kyoto University Free Electron Laser (KUFEL), and electron beams of 4-38 MeV are available. During the experiments, single electron beams bombarded a PWO crystal. By using oscilloscope we observed scintillation pulses of a PWO crystal coupled with a photomultiplier tube. Measured spectra were compared with the simulation code of EGS5 to analyze scattering effects. As the result, the pulse amplitudes show good linearity and the pulse shapes are almost constant in the observed energy range.

  10. Development of the first prototypes of Silicon PhotoMultiplier (SiPM) at ITC-irst

    Energy Technology Data Exchange (ETDEWEB)

    Dinu, N. [INFN Sezione di Padova (Gruppo Collegato di Trento), Trento 38050 (Italy)]. E-mail: dinu@itc.it; Battiston, R. [Universita di Perugia and INFN Sezione di Perugia, Perugia 06123 (Italy); Boscardin, M. [ITC-irst, Divisione Microsistemi, Trento 38050 (Italy); Collazuol, G. [Scuola Normale Superiore and INFN Sezione di Pisa, Pisa 56127 (Italy); Corsi, F. [DEE-Politecnico di Bari and INFN Sezione di Bari, Bari I-70125 (Italy); Dalla Betta, G.F. [INFN Sezione di Padova (Gruppo Collegato di Trento), Trento 38050 (Italy); Dipartimento di Informatica e Telecomunicazioni, Universita di Trento, Trento 38050 (Italy); Del Guerra, A. [Dipartimento di Fisica ' E. Fermi' and INFN Sezione di Pisa, Pisa 56127 (Italy); Llosa, G. [Dipartimento di Fisica ' E. Fermi' and INFN Sezione di Pisa, Pisa 56127 (Italy); Ionica, M. [Universita di Perugia and INFN Sezione di Perugia, Perugia 06123 (Italy); Levi, G. [Dipartimento di Fisica and INFN Sezione di Bologna, Bologna 40127 (Italy); Marcatili, S. [Dipartimento di Fisica ' E. Fermi' and INFN Sezione di Pisa, Pisa 56127 (Italy); Marzocca, C. [DEE-Politecnico di Bari and INFN Sezione di Bari, Bari I-70125 (Italy); Piemonte, C. [ITC-irst, Divisione Microsistemi, Trento 38050 (Italy); Pignatel, G. [Universita di Perugia and INFN Sezione di Perugia, Perugia 06123 (Italy); Pozza, A. [ITC-irst, Divisione Microsistemi, Trento 38050 (Italy); Quadrani, L. [Dipartimento di Fisica and INFN Sezione di Bologna, Bologna 40127 (Italy); Sbarra, C. [Centro Studi e Ricerche ' E. Fermi' , Compendio Viminale, 00184 Rome (Italy); Zorzi, N. [ITC-irst, Divisione Microsistemi, Trento 38050 (Italy)

    2007-03-01

    In the frame of INFN-ITC-irst collaboration new Silicon PhotoMultiplier (SiPM) prototypes have been produced at ITC-irst (Trento, Italy). Each SiPM covers an area of 1 mm{sup 2} and brings together 625 micro-cells of 40x40 {mu}m{sup 2} size connected in parallel as to form a single read-out element. Each micro-cell consists of a Geiger Mode Avalanche Photodiode (GM-APD) in series with its quenching resistance. This article reports the main characteristics of these prototypes as well as the ongoing activity of our collaboration on the development of SiPM devices for medical and space physics applications.

  11. Detecting Intracranial Hemorrhage Using Automatic Tube Current Modulation With Advanced Modeled Iterative Reconstruction in Unenhanced Head Single- and Dual-Energy Dual-Source CT.

    Science.gov (United States)

    Scholtz, Jan-Erik; Wichmann, Julian L; Bennett, Dennis W; Leithner, Doris; Bauer, Ralf W; Vogl, Thomas J; Bodelle, Boris

    2017-05-01

    The purpose of our study was to determine diagnostic accuracy, image quality, and radiation dose of low-dose single- and dual-energy unenhanced third-generation dual-source head CT for detection of intracranial hemorrhage (ICH). A total of 123 patients with suspected ICH were examined using a dual-source 192-MDCT scanner. Standard-dose 120-kVp single-energy CT (SECT; n = 36) and 80-kVp and 150-kVp dual-energy CT (DECT; n = 30) images were compared with low-dose SECT (n = 32) and DECT (n = 25) images obtained using automated tube current modulation (ATCM). Advanced modeled iterative reconstruction (ADMIRE) was used for all protocols. Detection of ICH was performed by three readers who were blinded to the image acquisition parameters of each image series. Image quality was assessed both quantitatively and qualitatively. Interobserver agreement was calculated using the Fleiss kappa. Radiation dose was measured as dose-length product (DLP). Detection of ICH was excellent (sensitivity, 94.9-100%; specificity, 94.7-100%) in all protocols (p = 1.00) with perfect interobserver agreement (0.83-0.96). Qualitative ratings showed significantly better ratings for both standard-dose protocols regarding gray matter-to-white matter contrast (p ≤ 0.014), whereas highest gray matter-to-white matter contrast-to-noise ratio was observed with low-dose DECT images (p ≥ 0.057). The lowest posterior fossa artifact index was measured for standard-dose DECT, which showed significantly lower values compared with low-dose protocols (p ≤ 0.034). Delineation of ventricular margins and sharpness of subarachnoidal spaces were rated excellent in all protocols (p ≥ 0.096). Low-dose techniques lowered radiation dose by 26% for SECT images (DLP, 575.0 ± 72.3 mGy · cm vs 771.5 ± 146.8 mGy · cm; p dual-source CT while allowing significant radiation dose reduction.

  12. Silicon photomultiplier (SPM) detection of low-level bioluminescence for the development of deployable whole-cell biosensors: possibilities and limitations.

    Science.gov (United States)

    Li, Huaqing; Lopes, Nicholas; Moser, Scott; Sayler, Gary; Ripp, Steven

    2012-03-15

    Whole-cell bacterial bioreporters await miniaturized photon counting modules with high sensitivity and robust compatible hardware to fulfill their promise of versatile, on-site biosensor functionality. In this study, we explore the photon counting readout properties of the silicon photomultiplier (SPM) with a thermoelectric cooler and the possibilities of detecting low-level bioluminescent signals. Detection performance was evaluated through a simulated LED light source and the bioluminescence produced by the genetically engineered Pseudomonas fluorescens bacterial bioreporter 5RL. Compared with the conventional photomultiplier tube (PMT), the results revealed that the cooled SPM exhibits a wider linear response to inducible substrate concentrations (salicylate) ranging from 250 to 5000 ppb. Although cooling of the SPM lowered dark count rates and improved the minimum detectable signal, and the application of a digital filter enhanced the signal-to-noise ratio, the detection of very low light signals is still limited and remains a challenge in the design of compact photon counting systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Application of the silicon photomultipliers for detectors in the GlueX experiment

    Energy Technology Data Exchange (ETDEWEB)

    Somov, Sergey V. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe shosse 31, Moscow, 115409, Russia; Tolstukhin, Ivan [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe shosse 31, Moscow, 115409, Russia; Somov, Alexander S. [Jefferson Lab, Newport News, VA

    2015-11-01

    The GlueX detector in Hall D at Jefferson Lab is instrumented with about 5000 Silicon Photomultipliers (SiPM) manufactured by Hamamatsu Corporation [2]. These photo sensors have properties similar to conventional photomultipliers but can be operated at high magnetic fields. Silicon photomultipliers with a sensitive area of 3x3 mm2 are used to detect light from the following GlueX scintillator detectors: the tagger microscope, pair spectrometer, and start counter. Arrays of 4x4 SiPMs sensors were chosen for the instrumentation of the barrel electromagnetic calorimeter. The tagger microscope must operate at high rates (up to 2.5 MHz) and provide time measurements with a resolution better than 0.3 ns. The paper will describe some results of the characterization of SiPMs for various GlueX sub-detectors.

  14. Segmented scintillation detectors with silicon photomultiplier readout for measuring antiproton annihilations

    CERN Document Server

    Sótér, A.; Kobayashi, T.; Barna, D.; Horváth, D.; Hori, M.

    2014-01-01

    The Atomic Spectroscopy and Collisions Using Slow Antiprotons (ASACUSA) experiment at the Antiproton Decelerator (AD) facility of CERN constructed segmented scintillators to detect and track the charged pions which emerge from antiproton annihilations in a future superconducting radiofrequency Paul trap for antiprotons. A system of 541 cast and extruded scintillator bars were arranged in 11 detector modules which provided a spatial resolution of 17 mm. Green wavelength-shifting fibers were embedded in the scintillators, and read out by silicon photomultipliers which had a sensitive area of 1 x 1 mm^2. The photoelectron yields of various scintillator configurations were measured using a negative pion beam of momentum p ~ 1 GeV/c. Various fibers and silicon photomultipliers, fiber end terminations, and couplings between the fibers and scintillators were compared. The detectors were also tested using the antiproton beam of the AD. Nonlinear effects due to the saturation of the silicon photomultiplier were seen a...

  15. Pressure drop and heat transfer of a mercury single-phase flow and an air-mercury two-phase flow in a helical tube under a strong magnetic field

    International Nuclear Information System (INIS)

    Takahashi, Minoru; Momozaki, Yoichi

    2000-01-01

    For the reduction of a large magneto-hydrodynamic (MHD) pressure drop of a liquid metal single-phase flow, a liquid metal two-phase flow cooling system has been proposed. As a fundamental study, MHD pressure drops and heat transfer characteristics of a mercury single-phase flow and an air-mercury two-phase flow were experimentally investigated. A strong transverse magnetic field relevant to the fusion reactor conditions was applied to the mercury single-phase flow and the air-mercury two-phase flow in a helically coiled tube that was inserted in the vertical bore of a solenoidal superconducting magnet. It was found that MHD pressure drops of a mercury single-phase flow in the helically coiled tube were nearly equal to those in a straight tube. The Nusselt number at an outside wall was higher than that at an inside wall both in the mercury single-phase flow in the absence and presence of a magnetic field. The Nusselt number of the mercury single-phase flow decreased, increased and again decreased with an increase in the magnetic flux density. MHD pressure drops did not decrease appreciably by injecting air into a mercury flow and changing the mercury flow into the air-mercury two-phase flow. Remarkable heat transfer enhancement did not appear by the air injection. The injection of air into the mercury flow enhanced heat transfer in the ranges of high mercury flow rate and low magnetic flux density, possibly due to the agitation effect of air bubbles. The air injection deteriorated heat transfer in the range of low mercury flow rates possibly because of the occupation of air near heating wall

  16. Ear Tubes

    Science.gov (United States)

    ... of the ear drum or eustachian tube, Down Syndrome, cleft palate, and barotrauma (injury to the middle ear caused by a reduction of air pressure, ... specialist) may be warranted if you or your child has experienced repeated ... fluid in the middle ear, barotrauma, or have an anatomic abnormality that ...

  17. Multi-time-over-threshold technique for photomultiplier signal processing: Description and characterization of the SCOTT ASIC

    International Nuclear Information System (INIS)

    Ferry, S.; Guilloux, F.; Anvar, S.; Chateau, F.; Delagnes, E.; Gautard, V.; Louis, F.; Monmarthe, E.; Le Provost, H.; Russo, S.; Schuller, J.-P.; Stolarczyk, Th.; Vallage, B.; Zonca, E.

    2012-01-01

    KM3NeT aims to build a cubic-kilometer scale neutrino telescope in the Mediterranean Sea based on a 3D array of photomultiplier tubes. A dedicated ASIC, named SCOTT, has been developed for the readout electronics of the PMTs: it uses up to 16 adjustable thresholds to digitize the signals with the multi-time-over-threshold technique. Digital outputs of discriminators feed a circular sampling memory and a “first in first out” digital memory for derandomization. At the end of the data processing, the ASIC produces a digital waveform sampled at 800 MHz. A specific study was carried out to process PMT data and has showed that five specifically chosen thresholds are suited to reach the required timing precision. A dedicated method based on the duration of the signal over a given threshold allows an equivalent timing precision at any charge. A charge estimator using the information from the thresholds allows a charge determination within less than 20% up to 60 pe.

  18. Multi-time-over-threshold technique for photomultiplier signal processing: Description and characterization of the SCOTT ASIC

    Science.gov (United States)

    Ferry, S.; Guilloux, F.; Anvar, S.; Chateau, F.; Delagnes, E.; Gautard, V.; Louis, F.; Monmarthe, E.; Le Provost, H.; Russo, S.; Schuller, J.-P.; Stolarczyk, Th.; Vallage, B.; Zonca, E.; Representing the KM3NeT Consortium

    2012-12-01

    KM3NeT aims to build a cubic-kilometer scale neutrino telescope in the Mediterranean Sea based on a 3D array of photomultiplier tubes. A dedicated ASIC, named SCOTT, has been developed for the readout electronics of the PMTs: it uses up to 16 adjustable thresholds to digitize the signals with the multi-time-over-threshold technique. Digital outputs of discriminators feed a circular sampling memory and a “first in first out” digital memory for derandomization. At the end of the data processing, the ASIC produces a digital waveform sampled at 800 MHz. A specific study was carried out to process PMT data and has showed that five specifically chosen thresholds are suited to reach the required timing precision. A dedicated method based on the duration of the signal over a given threshold allows an equivalent timing precision at any charge. A charge estimator using the information from the thresholds allows a charge determination within less than 20% up to 60 pe.

  19. Photomultipliers gain monitoring at the one percent level with a blue light pulser

    International Nuclear Information System (INIS)

    Berger, J.; Bermond, M.; Besson, P.; Favier, J.; Pessard, H.; Poulet, M.

    1988-07-01

    We describe a method and an experimental layout allowing the monitoring of photomultipliers gain. We use artificial blue light (Spark-gap with filter: 436 ± 20 nm) and three reference detectors. Short term and long term measurements are presented. The results indicate a precision better than 0.5% for the short term and 1.4% for the long term determinations. This gain monitoring system has been developed for a new neutrino oscillation reactor experiment (600 photomultipliers) starting at the Bugey nuclear plant

  20. Study of the Light Emission Process from the Double Chooz Photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, E.; Cerrada, M.; Crespo, J. I.; Gil-Botella, I.; Jimenez, S.; Lopez, M.; Novella, P.; Palomares, C.; Santorelli, R.; Verdugo, A.

    2012-09-13

    In this document we present a study of the light emitted by the base of a Hamamatsu R7081MOD-ASSY photomultiplier (PMT) of the same type used in the Double Chooz experiment. Several characteristic features of the light signal have been found in terms of amplitude, length and pulse shape. Additional investigations on the properties of the epoxy used to cover the photomultiplier base have been carried out. A possible explanation of the light emission process is discussed at the end of the study. (Author) 1 ref.

  1. Characterization of 1600 Hamamatsu 16-anode photomultipliers for the MINOS Far detector

    International Nuclear Information System (INIS)

    Lang, K.; Day, J.; Eilerts, S.; Fuqua, S.; Guillen, A.; Kordosky, M.; Lang, M.; Liu, J.; Opaska, W.; Proga, M.; Vahle, P.; Winbow, A.; Drake, G.; Thomas, J.; Andreopoulos, C.; Saoulidou, N.; Stamoulis, P.; Tzanakos, G.; Zois, M.; Weber, A.; Michael, D.

    2005-01-01

    We are reporting results of the characterization of over 1600 multi-anode R5900-00-M16 photomultipliers manufactured by Hamamatsu Photonics K.K., and installed in the MINOS Far detector. We have conducted extensive tests of the uniformity of gain and collection efficiency of individual anodes, the cross-talk among all 16 channels, the dark noise, and the linearity of response. In our studies we used a blue light-emitting diode to illuminate phototubes through 1.2 mm diameter optical fibers. In this paper, we present summaries of the main characteristics of the tested photomultipliers

  2. Pulse Shape Analysis and Discrimination for Silicon-Photomultipliers in Helium-4 Gas Scintillation Neutron Detector

    Science.gov (United States)

    Barker, Cathleen; Zhu, Ting; Rolison, Lucas; Kiff, Scott; Jordan, Kelly; Enqvist, Andreas

    2018-01-01

    Using natural helium (helium-4), the Arktis 180-bar pressurized gas scintillator is capable of detecting and distinguishing fast neutrons and gammas. The detector has a unique design of three optically separated segments in which 12 silicon-photomultiplier (SiPM) pairs are positioned equilaterally across the detector to allow for them to be fully immersed in the helium-4 gas volume; consequently, no additional optical interfaces are necessary. The SiPM signals were amplified, shaped, and readout by an analog board; a 250 MHz, 14-bit digitizer was used to examine the output pulses from each SiPMpair channel. The SiPM over-voltage had to be adjusted in order to reduce pulse clipping and negative overshoot, which was observed for events with high scintillation production. Pulse shaped discrimination (PSD) was conducted by evaluating three different parameters: time over threshold (TOT), pulse amplitude, and pulse integral. In order to differentiate high and low energy events, a 30ns gate window was implemented to group pulses from two SiPM channels or more for the calculation of TOT. It was demonstrated that pulses from a single SiPM channel within the 30ns window corresponded to low-energy gamma events while groups of pulses from two-channels or more were most likely neutron events. Due to gamma pulses having lower pulse amplitude, the percentage of measured gamma also depends on the threshold value in TOT calculations. Similarly, the threshold values were varied for the optimal PSD methods of using pulse amplitude and pulse area parameters. Helium-4 detectors equipped with SiPMs are excellent for in-the-field radiation measurement of nuclear spent fuel casks. With optimized PSD methods, the goal of developing a fuel cask content monitoring and inspection system based on these helium-4 detectors will be achieved.

  3. Neutron tubes

    Science.gov (United States)

    Leung, Ka-Ngo [Hercules, CA; Lou, Tak Pui [Berkeley, CA; Reijonen, Jani [Oakland, CA

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  4. Testing and simulation of silicon photomultiplier readouts for scintillators in high-energy astronomy and solar physics

    Science.gov (United States)

    Bloser, P. F.; Legere, J. S.; Bancroft, C. M.; Jablonski, L. F.; Wurtz, J. R.; Ertley, C. D.; McConnell, M. L.; Ryan, J. M.

    2014-11-01

    Space-based gamma-ray detectors for high-energy astronomy and solar physics face severe constraints on mass, volume, and power, and must endure harsh launch conditions and operating environments. Historically, such instruments have usually been based on scintillator materials due to their relatively low cost, inherent ruggedness, high stopping power, and radiation hardness. New scintillator materials, such as LaBr3:Ce, feature improved energy and timing performance, making them attractive for future astronomy and solar physics space missions in an era of tightly constrained budgets. Despite this promise, the use of scintillators in space remains constrained by the volume, mass, power, and fragility of the associated light readout device, typically a vacuum photomultiplier tube (PMT). In recent years, silicon photomultipliers (SiPMs) have emerged as promising alternative light readout devices that offer gains and quantum efficiencies similar to those of PMTs, but with greatly reduced mass and volume, high ruggedness, low voltage requirements, and no sensitivity to magnetic fields. In order for SiPMs to replace PMTs in space-based instruments, however, it must be shown that they can provide comparable performance, and that their inherent temperature sensitivity can be corrected for. To this end, we have performed extensive testing and modeling of a small gamma-ray spectrometer composed of a 6 mm×6 mm SiPM coupled to a 6 mm×6 mm ×10 mm LaBr3:Ce crystal. A custom readout board monitors the temperature and adjusts the bias voltage to compensate for gain variations. We record an energy resolution of 5.7% (FWHM) at 662 keV at room temperature. We have also performed simulations of the scintillation process and optical light collection using Geant4, and of the SiPM response using the GosSiP package. The simulated energy resolution is in good agreement with the data from 22 keV to 662 keV. Above ~1 MeV, however, the measured energy resolution is systematically worse than

  5. An ASIC for fast single photon counting in the LHCb RICH upgrade

    Science.gov (United States)

    Gotti, C.

    2017-03-01

    The LHCb experiment will be upgraded during the second LHC long shutdown (years 2019-2020) to operate at higher luminosity. The new triggerless architecture of LHCb requires data from the entire detector to be read out at 40 MHz. The basic element of the front-end electronics of the Ring Imaging Cherenkov (RICH) detector upgrade is the "Elementary Cell" (EC), a readout system for multianode photomultiplier tubes designed to minimise parasitic capacitance at the anodes, to obtain a fast readout with low noise and low crosstalk. At the heart of the EC is the CLARO, an 8 channel, low power and radiation hard front-end ASIC designed in 0.35 μm CMOS technology. Each channel compares the charge signals from the photomultiplier anodes with a programmable threshold, and gives a digital pulse at the output when the threshold is exceeded. Baseline recovery occurs in less than 25 ns for typical single photon signals. In the LHCb RICH upgrade environment, the chips will have to withstand radiation up to a total ionising dose of 2 kGy (200 krad) and neutron and hadron fluences up to 03×112 cm-2 and following irradiation, the chips have been shown to tolerate such doses with a margin of safety.

  6. Numerical and experimental study of an annular pulse tube used in the pulse tube cooler

    Science.gov (United States)

    Pang, Xiaomin; Chen, Yanyan; Wang, Xiaotao; Dai, Wei; Luo, Ercang

    2017-12-01

    Multi-stage pulse tube coolers normally use a U-type configuration. For compactness, it is attractive to build a completely co-axial multi-stage pulse tube cooler. In this way, an annular shape pulse tube is inevitable. Although there are a few reports about previous annular pulse tubes, a detailed study and comparison with a circular pulse tube is lacking. In this paper, a numeric model based on CFD software is carried out to compare the annular pulse tube and circular pulse tube used in a single stage in-line type pulse tube cooler with about 10 W of cooling power at 77 K. The length and cross sectional area of the two pulse tubes are kept the same. Simulation results show that the enthalpy flow in the annular pulse tube is lower by 1.6 W (about 11% of the enthalpy flow) compared to that in circular pulse tube. Flow and temperature distribution characteristics are also analyzed in detail. Experiments are then conducted for comparison with an in-line type pulse tube cooler. With the same acoustic power input, the pulse tube cooler with a circular pulse tube obtains 7.88 W of cooling power at 77 K, while using an annular pulse tube leads to a cooling power of 7.01 W, a decrease of 0.9 W (11.4%) on the cooling performance. The study sets the basis for building a completely co-axial two-stage pulse tube cooler.

  7. Characterization of the 10-stages R5900 Hamamatsu photomultipliers for the hadronic ATLAS calorimeter

    International Nuclear Information System (INIS)

    Montarou, G.; Bouhemaid, N.; Grenier, Ph.; Crouau, M.; Muanza, G.S.; Poirot, S.; Vazeille, F.; Gil Botella, I.; Hoz, S.G. de la

    1997-01-01

    The measurements carried out, at Clermont on the R5900 Hamamatsu photomultipliers for the ATLAS hadronic calorimeter are summarised. The TILECAL specifications are given. Amplification measurements, dark current measurements, linearity, magnetic sensitivity and the voltage divider optimisation are presented. (K.A.)

  8. Fast tracking detector with fiber scintillators and a position sensitive photomultiplier

    International Nuclear Information System (INIS)

    Salomon, M.; Li, V.; Smith, G.; Wu, Y.S.

    1988-11-01

    We have studied the properties of a tracking detector composed of 32 fiber scintillators coupled to a multianode photomultiplier placed in a pion beam at TRIUMF. We measured the efficiency of the detector, as well as its tracking capabilities and double hit resolution

  9. A method to stabilise the performance of negatively fed KM3NeT photomultipliers

    NARCIS (Netherlands)

    Adrián-Martínez, S.; van Haren, H.; KM3NeT Collaboration

    2016-01-01

    The KM3NeT research infrastructure, currently under construction in the Mediterranean Sea, will host neutrino telescopes for the identification of neutrino sources in the Universe and for studies of the neutrino mass hierarchy. These telescopes will house hundreds of thousands of photomultiplier

  10. Silicon photomultiplier's gain stabilization by bias correction for compensation of the temperature fluctuations

    International Nuclear Information System (INIS)

    Dorosz, P.; Baszczyk, M.; Glab, S.; Kucewicz, W.; Mik, L.; Sapor, M.

    2013-01-01

    Gain of the silicon photomultiplier is strongly dependent on the value of bias voltage and temperature. This paper proposes a method for gain stabilization just by compensation of temperature fluctuations by bias correction. It has been confirmed that this approach gives good results and the gain can be kept very stable

  11. Electronics of the data acquisition system of the DANSS detector based on silicon photomultipliers

    Science.gov (United States)

    Svirida, D.

    2018-01-01

    The electronics of the data acquisition system based on silicon photomultipliers is briefly described. The elements and modules of the system were designed and constructed at ITEP especially for the DANSS detector. Examples of digitized signals obtained with the presented electronic modules and selected results on processing of the DANSS engineering data-taking run in spring 2016 are given.

  12. Characterization of the 10-stages R5900 Hamamatsu photomultipliers for the hadronic ATLAS calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Montarou, G.; Bouhemaid, N.; Grenier, Ph.; Crouau, M.; Muanza, G.S.; Poirot, S.; Vazeille, F. [Clermont-Ferrand-2 Univ., 63 - Aubiere (France). Lab. de Physique Corpusculaire; Gil Botella, I.; Hoz, S.G. de la [Valencia Univ., Burjassot (Spain) Inst. de Fisica Corpuscular

    1997-12-31

    The measurements carried out, at Clermont on the R5900 Hamamatsu photomultipliers for the ATLAS hadronic calorimeter are summarised. The TILECAL specifications are given. Amplification measurements, dark current measurements, linearity, magnetic sensitivity and the voltage divider optimisation are presented. (K.A.).

  13. High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ronzhin, A.; Los, S.; Martens, M.; Ramberg, E.; /Fermilab; Kim, H.; Chen, C.; Kao, C.; /Chicago U.; Niessen, K.; /SUNY, Buffalo; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez; Mazzillo, M.; Carbone, B.; /SGS Thomson, Catania

    2011-02-01

    We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomography (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile

  14. Study of the silicon photomultipliers and their applications in positron emission tomography

    International Nuclear Information System (INIS)

    Xu, Chen

    2014-05-01

    This thesis deals with silicon photomultipliers (SiPM) used in scintillation detectors and their applications in positron emission tomography (PET). The study of the SiPM is mainly focused on the application to the proposed EndoTOFPET-US detector, which is a multi-modality PET detector facilitating the development of new biomarkers for pancreas and prostate cancers. A Monte Carlo simulation tool is developed for the optimization of the detector's single channel design. In order to obtain a 200 ps system coincidence time resolution and maximize the detector sensitivity, the requirements for the crystal geometry, light yield and SiPM photon detection efficiency are specified based on the simulation study. In addition, the nonlinear response of the SiPM can be corrected by the simulation tool and the energy resolution of the detector is extracted. A series of measurements are established to characterize SiPMs in a fast and reliable way with high precision. The static characterization measures the value of different components in the derived electrical model of the SiPM, whereas the dynamic characterization extracts parameters that is crucial for the operation of the SiPM. Several SiPM samples are tested and their characteristics are compared. The developed setup and the precision of the measurement fulfill the requirements of the quality assurance test for the commissioning of the EndoTOFPET-US detector. The test foresees large quantities of SiPMs to be characterized. In addition, the developed measuring procedure has contributed to the study of X-ray induced surface damage of a SiPM from Hamamatsu. Characteristics of the device are measured before and after irradiating the SiPM with different X-ray doses, the results are compared and discussed. A comparative study of a digital and an analog SiPM in gamma spectroscopy with the inorganic scintillator is presented. The characteristics of a prototype digital SiPM that is developed for the EndoTOFPETUS detector is

  15. Energy resolution measurements of LaBr3:Ce scintillating crystals with an ultra-high quantum efficiency photomultiplier tube

    International Nuclear Information System (INIS)

    Pani, R.; Cinti, M.N.; Scafe, R.; Pellegrini, R.; Vittorini, F.; Bennati, P.; Ridolfi, S.; Lo Meo, S.; Mattioli, M.; Baldazzi, G.; Pisacane, F.; Navarria, F.; Moschini, G.; Boccaccio, P.; Orsolini Cencelli, V.; Sacco, D.

    2009-01-01

    The performance of the new prototype of high quantum efficiency PMT (43% at 380 nm), Hamamatsu R7600U-200, was studied coupled to a LaBr 3 :Ce crystal with the size of o12.5 mmx12.5 mm. The energy resolution results were compared with ones from two PMTs, Hamamatsu R7600U and R6231MOD, with 22% and 30% quantum efficiency (QE), respectively. Moreover, the photodetectors were equipped with tapered and un-tapered voltage dividers to study the non-linearity effects on pulse height distribution, due to very high peak currents induced in the PMT by the fast and intense light pulse of LaBr 3 :Ce. The results show an energy resolution improvement with UBA PMT of about 20%, in the energy range of 80-662 keV, with respect to the BA one.

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

    Directory of Open Access Journals (Sweden)

    Weihua Zhang

    2011-01-01

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

  17. Study of multianode photomultipliers for the electromagnetic calorimeter preshower read out of the LHCb experiment

    CERN Document Server

    Aguiló, Ernest; Gascon, David; Ajaltouni, Ziad J; Böhner, G; Cârloganu, C; Cornat, R; Crouau, M; Deschamps, O; Henrard, P; Lecoq, J; Lefèvre, R; Monteil, S; Perret, P; Rimbault, C

    2003-01-01

    The LHCb experiment will study the CP symmetry violation in the system of the beauty particles. The detector is a 20-m-long spectrometer, to be installed on the proton-proton collider LHC. Of major importance for the level 0 trigger is the preshower of the electromagnetic calorimeter designed to discriminate between electrons, hadrons and photons. The preshower cells consist of a two- radiation-length lead sheet located between two plastic scintillator planes. The scintillation light is extracted with wavelength-shifting fibres. The best candidates to read out the light of the 6000 detector cells are multianode photomultipliers. The HAMAMATSU photomultiplier R5900-00-M64 has been studied and its responses in terms of gain, linearity, uniformity within and between the anodes and cross-talk between the channels are addressed in this document.

  18. Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array

    International Nuclear Information System (INIS)

    Álvarez, V; Cárcel, S; Cervera, A; Díaz, J; Ferrario, P; Gil, A; Borges, F I G; Conde, C A N; Dias, T H V T; Fernandes, L M P; Freitas, E D C; Castel, J; Cebrián, S; Dafni, T; Egorov, M; Gehman, V M; Goldschmidt, A; Esteve, R; Evtoukhovitch, P; Ferreira, A L

    2013-01-01

    NEXT-DEMO is a high-pressure xenon gas TPC which acts as a technological test-bed and demonstrator for the NEXT-100 neutrinoless double beta decay experiment. In its current configuration the apparatus fully implements the NEXT-100 design concept. This is an asymmetric TPC, with an energy plane made of photomultipliers and a tracking plane made of silicon photomultipliers (SiPM) coated with TPB. The detector in this new configuration has been used to reconstruct the characteristic signature of electrons in dense gas, demonstrating the ability to identify the MIP and ''blob'' regions. Moreover, the SiPM tracking plane allows for the definition of a large fiducial region in which an excellent energy resolution of 1.82% FWHM at 511 keV has been measured (a value which extrapolates to 0.83% at the xenon Q ββ )

  19. Development of Silicon Photomultipliers and their Applications to GlueX Calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Elton S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-07-01

    The GlueX experiment is a photoproduction experiment in Hall D at Jefferson Lab that is being commissioned for use with the new 12 GeV accelerator. The purpose of the experiment is to search for Hybrid mesons, which are mesons with quark and gluon degrees of freedom. The barrel calorimeter of GlueX is instrumented with 4000 large-area (1.2 x1.2 cm2) silicon photomultipliers (SiPMs). These photon sensors have properties similar to vacuum photomultipliers, but are unaffected by high magnetic fields. In our experiment they operate in magnetic fields exceeding 1T. After extensive tests with a variety of sensors, we chose the S12045(X) custom SiPM arrays manufactured by Hamamatsu Corporation, also known as multi-pixel photon counters (MPPCs). We will give an overview of this new technology as well as the experience gained during two commissioning periods with beam.

  20. SHEATHED TUBE AND APPARATUS AND METHOD OF PRODUCTION THEREOF

    Science.gov (United States)

    Ohlinger, L.A.

    1959-08-18

    A tubular fuel element covered inside and out by a unitary covering tube originally about twice its length and of small enough diameter to fit snugly inside the fuel tube is described. The covering tube is then reentrantly folded back by a pressure-die mechanism over both ends of the fuel tube and againsts outside until the folded back ends of the covering tube meet where they are welded in a single seam running circumferentially around the middle of the resulting assembly.

  1. Time-domain diffuse optical tomography using silicon photomultipliers: feasibility study

    OpenAIRE

    Di Sieno, Laura; Zouaoui, Judy; Hervé, Lionel; Pifferi, Antonio; Farina, Andrea; Martinenghi, Edoardo; Derouard, Jacques; Dinten, Jean-Marc; Dalla Mora, Alberto

    2016-01-01

    International audience; Silicon photomultipliers (SiPMs) have been very recently introduced as the most promising detectors in the field of diffuse optics, in particular due to the inherent low cost and large active area. We also demonstrate the suitability of SiPMs for time-domain diffuse optical tomography (DOT). The study is based on both simulations and experimental measurements. Results clearly show excellent performances in terms of spatial localization of an absorbing perturbation, thu...

  2. An innovative silicon photomultiplier digitizing camera for gamma-ray astronomy

    Czech Academy of Sciences Publication Activity Database

    Heller, M.; Schioppa, E.jr.; Porcelli, A.; Pujadas, I.T.; Zietara, K.; della Volpe, D.; Montaruli, T.; Cadoux, F.; Favre, Y.; Aguilar, J.A.; Christov, A.; Prandini, E.; Rajda, P.; Rameez, M.; Bilnik, W.; Blocki, J.; Bogacz, L.; Borkowski, J.; Bulik, T.; Frankowski, A.; Grudzinska, M.; Idzkowski, B.; Jamrozy, M.; Janiak, M.; Kasperek, J.; Lalik, K.; Lyard, E.; Mach, E.; Mandát, Dušan; Marszalek, A.; Medina Miranda, L. D.; Michałowski, J.; Moderski, R.; Neronov, A.; Niemiec, J.; Ostrowski, M.; Pasko, P.; Pech, Miroslav; Schovánek, Petr; Seweryn, K.; Sliusar, V.; Skowron, K.; Stawarz, L.; Stodulska, M.; Stodulski, M.; Walter, R.; Wiecek, M.; Zagdanski, A.

    2017-01-01

    Roč. 77, č. 1 (2017), s. 1-31, č. článku 47. ISSN 1434-6044 R&D Projects: GA MŠk LE13012; GA MŠk LG14019 Institutional support: RVO:68378271 Keywords : silicon photomultiplier * digitizing camera * gamma-ray astronomy Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 5.331, year: 2016

  3. Single-portal-phase low-tube-voltage dual-energy CT for short-term follow-up of acute pancreatitis: evaluation of CT severity index, interobserver agreement and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Wichmann, Julian L. [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Universitaetsklinikum Frankfurt, Institut fuer Diagnostische und Interventionelle Radiologie, Frankfurt am Main (Germany); Majenka, Pawel; Beeres, Martin; Kromen, Wolfgang; Schulz, Boris; Bauer, Ralf W.; Kerl, J.M.; Gruber-Rouh, Tatjana; Hammerstingl, Renate; Vogl, Thomas J.; Lehnert, Thomas [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Wesarg, Stefan [Fraunhofer IGD, Cognitive Computing and Medical Imaging, Darmstadt (Germany)

    2014-11-15

    To intra-individually compare single-portal-phase low-tube-voltage (100-kVp) computed tomography (CT) with 120-kVp images for short-term follow-up assessment of CT severity index (CTSI) of acute pancreatitis, interobserver agreement and radiation dose. We retrospectively analysed 66 patients with acute pancreatitis who underwent initial dual-contrast-phase CT (unenhanced, arterial, portal phase) at admission and short-term (mean interval 11.4 days) follow-up dual-contrast-phase dual-energy CT. The 100-kVp and linearly blended images representing 120-kVp acquisition follow-up CT images were independently evaluated by three radiologists using a modified CTSI assessing pancreatic inflammation, necrosis and extrapancreatic complications. Scores were compared with paired t test and interobserver agreement was evaluated using intraclass correlation coefficients (ICC). Mean CTSI scores on unenhanced, portal- and dual-contrast-phase images were 4.9, 6.1 and 6.2 (120 kVp) and 5.0, 6.0 and 6.1 (100 kVp), respectively. Contrast-enhanced series showed a higher CTSI compared to unenhanced images (P < 0.05) but no significant differences between single- and dual-contrast-phase series (P > 0.7). CTSI scores were comparable for 100-kVp and 120-kVp images (P > 0.05). Interobserver agreement was substantial for all evaluated series and subcategories (ICC 0.67-0.93). DLP of single-portal-phase 100-kVp images was reduced by 41 % compared to 120-kVp images (363.8 versus 615.9 mGy cm). Low-tube-voltage single-phase 100-kVp CT provides sufficient information for follow-up evaluation of acute pancreatitis and significantly reduces radiation exposure. (orig.)

  4. Vibrations of tube arrays in transversal flow

    International Nuclear Information System (INIS)

    Gibert, R.J.; Doyen, R.

    1981-08-01

    In this study the local forces per unit length acting in a tube in a single row and in bundle have been measured. Their modification by a given harmonic motion of the tube itself or of an adjacent tube has been particularly studied. Some complementary experiments have been performed to extend the whirling coefficient tabulation and also to precise the effect of the upstream velocity profile on the whirling critical velocities [fr

  5. Tracheostomy tube - eating

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000464.htm Tracheostomy tube - eating To use the sharing features on ... when you swallow foods or liquids. Eating and Tracheostomy Tubes When you get your tracheostomy tube, or ...

  6. Eustachian tube patency

    Science.gov (United States)

    Eustachian tube patency refers to how much the eustachian tube is open. The eustachian tube runs between the middle ear and the throat. It controls the pressure behind the eardrum and middle ear space. This helps keep ...

  7. Heat exchanger tube mounts

    Science.gov (United States)

    Wolowodiuk, W.; Anelli, J.; Dawson, B.E.

    1974-01-01

    A heat exchanger in which tubes are secured to a tube sheet by internal bore welding is described. The tubes may be moved into place in preparation for welding with comparatively little trouble. A number of segmented tube support plates are provided which allow a considerable portion of each of the tubes to be moved laterally after the end thereof has been positioned in preparation for internal bore welding to the tube sheet. (auth)

  8. Photoelectron backscattering from silicon anodes of hybrid photodetector tubes

    CERN Document Server

    D'Ambrosio, C

    2000-01-01

    The impact of photoelectron backscattering on spectral distributions measured with hybrid photodetector tubes has been calculated. The calculations are based on the backscattering coefficient mu , the average number of photoelectrons N/sub phel/ emitted from the photocathode, and on the distribution of the fractional photoelectron energy q absorbed in silicon during the backscattering process. We obtained the following results: the average number of absorbed (measured) photoelectrons N/sub meas/ in the silicon anode amounts to ~88% of the incident N/sub phel/. Photoelectron- and gamma-absorption peaks are broadened by a factor 1.043 due to backscattering. As an example, for photomultiplier tubes, this broadening can amount to an average factor of 1.18 due to statistic and gain fluctuations on the dynode chain. (15 refs).

  9. Tube holding system

    International Nuclear Information System (INIS)

    Cunningham, R.C.

    1978-01-01

    A tube holding rig is described for the lateral support of tubes arranged in tight parcels in a heat exchanger. This tube holding rig includes not less than two tube supporting assemblies, with a space between them, located crosswise with respect to the tubes, each supporting assembly comprising a first set of parallel components in contact with the tubes, whilst a second set of components is also in contact with the tubes. These two sets of parts together define apertures through which the tubes pass [fr

  10. STiC — a mixed mode silicon photomultiplier readout ASIC for time-of-flight applications

    International Nuclear Information System (INIS)

    Harion, T; Briggl, K; Chen, H; Gil, A; Kiworra, V; Schultz-Coulon, H-C; Shen, W; Stankova, V; Fischer, P; Ritzert, M

    2014-01-01

    STiC is an application specific integrated circuit (ASIC) for the readout of silicon photomultipliers. The chip has been designed to provide a very high timing resolution for time-of-flight applications in medical imaging and particle physics. It is dedicated in particular to the EndoToFPET-US project, which is developing an endoscopic PET detector combined with ultrasound imaging for early pancreas and prostate cancer detection. This PET system aims to provide a spatial resolution of 1 mm and a time-of-flight resolution of 200 ps FWHM. The analog frontend of STiC can use either a differential or single ended connection to the SiPM. The time and energy information of the detector signal is encoded into two time stamps. A special linearized time-over-threshold method is used to obtain a linear relation between the signal charge and the measured signal width, improving the energy resolution. The trigger signals are digitized by an integrated TDC module with a resolution of less than 20 ps. The TDC data is stored in an internal memory and transfered over a 160 MBit/s serial link using 8/10 bit encoding. First coincidence measurements using a 3.1 × 3.1 × 15 mm 3 LYSO crystal and a S10362-33-50 Hamamtsu MPPC show a coincidence time resolution of less than 285 ps. We present details on the chip design as well as first characterization measurements

  11. Sound absorption and reflection with coupled tubes

    NARCIS (Netherlands)

    van der Eerden, F.J.M.

    2000-01-01

    This paper describes a special sound absorbing technique with an accompanying efficient numerical design tool. As a basis pressure waves in a single narrow tube or pore are considered. In such a tube the viscosity and the thermal conductivity of the air, or any other fluid, can have a significant

  12. Laser-induced down-conversion parameters of singly and doubly ...

    Indian Academy of Sciences (India)

    emission from the sample at an angle of 90◦ to the incident beam was collected by a fast photomultiplier tube (PMT) through an assembly of monochromator and glass slab used as a UV filter (figure 1). The decay signals from the phosphors were recorded by digital storage oscilloscope coupled with computer assembly. The.

  13. Experimental analysis of solar thermal integrated MD system for cogeneration of drinking water and hot water for single family villa in dubai using flat plate and evacuated tube solar collectors

    DEFF Research Database (Denmark)

    Asim, Muhammad; Imran, Muhammad; Leung, Michael K.H.

    2017-01-01

    This paper presents the experimental analysis performed on solar thermal integrated membrane distillation (MD) system using flat plate and evacuated tube collectors. The system will be utilized for cogeneration of drinking water and domestic hot water for single family in Dubai comprising of four...... on MD setup at optimized flow rates of 6 L/min on hot side and 3 L/min on cold side for producing the desired distillate. The hot side and cold side MD temperature has been maintained between 60°C and 70°C, and 20°C and 30°C. The total annual energy demand comes out to be 8,223 kWh (6,000 k......Wh is for pure water and 2,223 kWh for hot water). The optimum aperture areas for flat plate and evacuated tube collector field have been identified as 8.5 and 7.5 m2, respectively. Annual energy consumption per liter for pure water production is 1, 0.85 and 0.7 kWh/L for different MD hot and cold inlet...

  14. Mitigating radiation damage of single photon detectors for space applications

    Energy Technology Data Exchange (ETDEWEB)

    Anisimova, Elena; Higgins, Brendon L.; Bourgoin, Jean-Philippe [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Cranmer, Miles [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); Choi, Eric [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); Magellan Aerospace, Ottawa, ON (Canada); Hudson, Danya; Piche, Louis P.; Scott, Alan [Honeywell Aerospace (formerly COM DEV Ltd.), Ottawa, ON (Canada); Makarov, Vadim [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); University of Waterloo, Department of Electrical and Computer Engineering, Waterloo, ON (Canada); Jennewein, Thomas [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Canadian Institute for Advanced Research, Quantum Information Science Program, Toronto, ON (Canada)

    2017-12-15

    Single-photon detectors in space must retain useful performance characteristics despite being bombarded with sub-atomic particles. Mitigating the effects of this space radiation is vital to enabling new space applications which require high-fidelity single-photon detection. To this end, we conducted proton radiation tests of various models of avalanche photodiodes (APDs) and one model of photomultiplier tube potentially suitable for satellite-based quantum communications. The samples were irradiated with 106 MeV protons at doses approximately equivalent to lifetimes of 0.6, 6, 12 and 24 months in a low-Earth polar orbit. Although most detection properties were preserved, including efficiency, timing jitter and afterpulsing probability, all APD samples demonstrated significant increases in dark count rate (DCR) due to radiation-induced damage, many orders of magnitude higher than the 200 counts per second (cps) required for ground-to-satellite quantum communications. We then successfully demonstrated the mitigation of this DCR degradation through the use of deep cooling, to as low as -86 C. This achieved DCR below the required 200 cps over the 24 months orbit duration. DCR was further reduced by thermal annealing at temperatures of +50 to +100 C. (orig.)

  15. A sampling ultra-high-speed streak camera based on the use of a unique photomultiplier

    International Nuclear Information System (INIS)

    Marode, Emmanuel

    An apparatus reproducing the ''streak'' mode of a high-speed camera is proposed for the case of a slit AB whose variations in luminosity are repetitive. A photomultiplier, analysing the object AB point by point, and a still camera, photographing a slit fixed on the oscilloscope screen parallel to the sweep direction are placed on a mobile platform P. The movement of P assures a time-resolved analysis of AB. The resolution is of the order of 2.10 -9 s, and can be improved [fr

  16. Tine-of-flight characteristics of the scintillation counters with microgrid photomultipliers

    International Nuclear Information System (INIS)

    Akindinov, A.V.; Kiselev, Yu.T.; Martem'yanov, A.N.; Ushakov, V.I.

    2003-01-01

    The time-of-flight characteristics of the scintillation counters with the microgrid dynodes magnetically stable photomultipliers are measured. The scintillation counters with thin plastic scintillators 1.3 and 5 mm thick were intended for operation in the relatively strong scattered magnetic fields up to several kilogauss. The measurements were accomplished in the proton synchrotron beams with the protons and π + -mesons pulses of 0.63 and 1.03 GeV/s and with the π - -mesons pulses of 1.28 GeV/s. The time resolutions in the interval of 45-180 ps are obtained [ru

  17. Time-domain diffuse optical tomography using silicon photomultipliers: feasibility study.

    Science.gov (United States)

    Di Sieno, Laura; Zouaoui, Judy; Hervé, Lionel; Pifferi, Antonio; Farina, Andrea; Martinenghi, Edoardo; Derouard, Jacques; Dinten, Jean-Marc; Mora, Alberto Dalla

    2016-11-01

    Silicon photomultipliers (SiPMs) have been very recently introduced as the most promising detectors in the field of diffuse optics, in particular due to the inherent low cost and large active area. We also demonstrate the suitability of SiPMs for time-domain diffuse optical tomography (DOT). The study is based on both simulations and experimental measurements. Results clearly show excellent performances in terms of spatial localization of an absorbing perturbation, thus opening the way to the use of SiPMs for DOT, with the possibility to conceive a new generation of low-cost and reliable multichannel tomographic systems.

  18. Characterization and Optimization of silicon photomultipliers for the development of intraoperative beta probes

    Energy Technology Data Exchange (ETDEWEB)

    Hudin, N.; Pinot, L. [Laboratoire Imagerie et Modelisation en Neurobiologie et Cancerologie (UMR 8165), Campus d' Orsay, IN2P3-CNRS, 91406 Orsay Cedex (France); Dinu, N. [Laboratoire de l' Accelerateur Lineaire, IN2P3-CNRS, 91898 Orsay (France); Charon, Y. [Laboratoire Imagerie et Modelisation en Neurobiologie et Cancerologie (UMR 8165), Campus d' Orsay, IN2P3-CNRS, 91406 Orsay Cedex (France); Puill, V. [Laboratoire de l' Accelerateur Lineaire, IN2P3-CNRS, 91898 Orsay (France); Janvier, B. [Laboratoire Imagerie et Modelisation en Neurobiologie et Cancerologie (UMR 8165), Campus d' Orsay, IN2P3-CNRS, 91406 Orsay Cedex (France); Chaumat, V. [Laboratoire de l' Accelerateur Lineaire, IN2P3-CNRS, 91898 Orsay (France); Duval, M.-A.; Abi Haidar, D.; Siebert, R. [Laboratoire Imagerie et Modelisation en Neurobiologie et Cancerologie (UMR 8165), Campus d' Orsay, IN2P3-CNRS, 91406 Orsay Cedex (France); Menard, L., E-mail: menard@imnc.in2p3.fr [Laboratoire Imagerie et Modelisation en Neurobiologie et Cancerologie (UMR 8165), Campus d' Orsay, IN2P3-CNRS, 91406 Orsay Cedex (France)

    2012-12-11

    This work reports the results of a comprehensive study aiming to characterize and optimize the performances of Silicon Photomultipliers (SiPM) as photodetectors for intraoperative beta detection of radiolabeled tumor tissues. In that purpose, we focused our measurements on the influence of temperature and operating voltage on dark noise (count rate and amplitude distribution), absolute photon detection efficiency and total gain of different SiPM devices from Hamamatsu. The impact of these parameters on the overall beta sensitivity of SiPM-based scintillation detectors was quantified as a function of the intensity of the incident light following a simple physical model that is shown to correspond well with measurements.

  19. Reconstruction of scintillations coordinates in cylindrical large detector with radial arrangement of photomultipliers

    CERN Document Server

    Alekseev, V M; Verbitskij, V S; Verbitskij, S S; Lapik, M A; Tselebrovskij, A N; Lapik, A M; Rusakov, A V; Savopulo, M L; Smirnov, V V; Chubarov, M N

    2002-01-01

    Paper describes algorithm to calculate scintillation coordinates elaborated for a coordinate-sensitive large detector based on liquid scintillator with radial arrangement of nine FEU-174 photomultipliers. Paper contains the simulation results of coordinate resolution dependence in detector centre on energy of gamma-quanta within 0.2-8 MeV range. Using this algorithm one processed the experimental data obtained with application of sup 6 sup 0 Co gamma-radiation source and the results of determination of scintillation coordinates for gamma-quanta beam. The accuracy of coordinate determination in detector centre when applying the descried algorithm constitutes approx 10 mm

  20. Photoelectron yields of scintillation counters with embedded wavelength-shifting fibers read out with silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Artikov, Akram; Baranov, Vladimir; Blazey, Gerald C.; Chen, Ningshun; Chokheli, Davit; Davydov, Yuri; Dukes, E. Craig; Dychkant, Alexsander; Ehrlich, Ralf; Francis, Kurt; Frank, M. J.; Glagolev, Vladimir; Group, Craig; Hansen, Sten; Magill, Stephen; Oksuzian, Yuri; Pla-Dalmau, Anna; Rubinov, Paul; Simonenko, Aleksandr; Song, Enhao; Stetzler, Steven; Wu, Yongyi; Uzunyan, Sergey; Zutshi, Vishnu

    2018-05-01

    Photoelectron yields of extruded scintillation counters with titanium dioxide coating and embedded wavelength shifting fibers read out by silicon photomultipliers have been measured at the Fermilab Test Beam Facility using 120\\,GeV protons. The yields were measured as a function of transverse, longitudinal, and angular positions for a variety of scintillator compositions and reflective coating mixtures, fiber diameters, and photosensor sizes. Timing performance was also studied. These studies were carried out by the Cosmic Ray Veto Group of the Mu2e collaboration as part of their R\\&D program.

  1. GEM-based gaseous photomultipliers for UV and visible photon imaging

    International Nuclear Information System (INIS)

    Moermann, D.; Balcerzyk, M.; Breskin, A.; Chechik, R.; Singh, B.K.; Buzulutskov, A.

    2003-01-01

    We present the current status of our research on GEM-based gaseous photomultipliers. Detectors combining multi-GEM electron multipliers with semi-transparent and reflective photocathodes are discussed. We present recent progress in extending the sensitivity of these detectors into the visible range. We demonstrate the long-term stability of an argon-sealed bi-alkali photo-diode and provide preliminary results of a gas-sealed Kapton-GEM detector with a bi-alkali photocathode. The problem of ion-induced secondary electron emission is addressed

  2. Ultrafast readout of scintillating fibers using upgraded position-sensitive photomultipliers

    International Nuclear Information System (INIS)

    Onel, Y.

    1994-01-01

    Experimental results obtained with commercially available position-sensitive photomultipliers (PSPM) coupled with 0.5 mm diameter scintillating fiber arrays show some promising performances such as space resolution better than 200 μm and time resolution ∼ 1.5 ns with a detection efficiency higher than 90%. Major progress has also been recently achieved with an upgrade of a PSPM based on new grid dynode structures. Two-track spatial resolution has been studied using the upgraded PSPM. Initial studies demonstrate that two tracks separated by a minimum distance of 3 mm are resolved

  3. Probing DNA interactions with proteins using a single-molecule toolbox: inside the cell, in a test tube and in a computer.

    Science.gov (United States)

    Wollman, Adam J M; Miller, Helen; Zhou, Zhaokun; Leake, Mark C

    2015-04-01

    DNA-interacting proteins have roles in multiple processes, many operating as molecular machines which undergo dynamic meta-stable transitions to bring about their biological function. To fully understand this molecular heterogeneity, DNA and the proteins that bind to it must ideally be interrogated at a single molecule level in their native in vivo environments, in a time-resolved manner, fast enough to sample the molecular transitions across the free-energy landscape. Progress has been made over the past decade in utilizing cutting-edge tools of the physical sciences to address challenging biological questions concerning the function and modes of action of several different proteins which bind to DNA. These physiologically relevant assays are technically challenging but can be complemented by powerful and often more tractable in vitro experiments which confer advantages of the chemical environment with enhanced detection signal-to-noise of molecular signatures and transition events. In the present paper, we discuss a range of techniques we have developed to monitor DNA-protein interactions in vivo, in vitro and in silico. These include bespoke single-molecule fluorescence microscopy techniques to elucidate the architecture and dynamics of the bacterial replisome and the structural maintenance of bacterial chromosomes, as well as new computational tools to extract single-molecule molecular signatures from live cells to monitor stoichiometry, spatial localization and mobility in living cells. We also discuss recent developments from our laboratory made in vitro, complementing these in vivo studies, which combine optical and magnetic tweezers to manipulate and image single molecules of DNA, with and without bound protein, in a new super-resolution fluorescence microscope.

  4. Development of high performance readout ASICs for silicon photomultipliers (SiPMs)

    International Nuclear Information System (INIS)

    Shen, Wei

    2012-01-01

    Silicon Photomultipliers (SiPMs) are novel kind of solid state photon detectors with extremely high photon detection resolution. They are composed of hundreds or thousands of avalanche photon diode pixels connected in parallel. These avalanche photon diodes are operated in Geiger Mode. SiPMs have the same magnitude of multiplication gain compared to the conventional photomultipliers (PMTs). Moreover, they have a lot of advantages such as compactness, relatively low bias voltage and magnetic field immunity etc. Special readout electronics are required to preserve the high performance of the detector. KLauS and STiC are two CMOS ASIC chips designed in particular for SiPMs. KLauS is used for SiPM charge readout applications. Since SiPMs have a much larger detector capacitance compared to other solid state photon detectors such as PIN diodes and APDs, a few special techniques are used inside the chip to make sure a descent signal to noise ratio for pixel charge signal can be obtained. STiC is a chip dedicated to SiPM time-of-flight applications. High bandwidth and low jitter design schemes are mandatory for such applications where time jitter less than tens of picoseconds is required. Design schemes and error analysis as well as measurement results are presented in the thesis.

  5. Characterization studies of Silicon Photomultipliers and crystals matrices for a novel time of flight PET detector

    CERN Document Server

    Auffray, Etiennette; Cortinovis, Daniele; Doroud, Katayoun; Garutti, Erika; Lecoq, Paul; Liu, Zheng; Martinez, Rosana; Paganoni, Marco; Pizzichemi, Marco; Silenzi, Alessandro; Xu, Chen; Zvolský, Milan

    2015-01-01

    This paper describes the characterization of crystal matrices and silicon photomultiplier arrays for a novel Positron Emission Tomography (PET) detector, namely the external plate of the EndoTOFPET-US system. The EndoTOFPET-US collaboration aims to integrate Time-Of-Flight PET with ultrasound endoscopy in a novel multimodal device, capable to support the development of new biomarkers for prostate and pancreatic tumors. The detector consists in two parts: a PET head mounted on an ultrasound probe and an external PET plate. The challenging goal of 1 mm spatial resolution for the PET image requires a detector with small crystal size, and therefore high channel density: 4096 LYSO crystals individually readout by Silicon Photomultipliers (SiPM) make up the external plate. The quality and properties of these components must be assessed before the assembly. The dark count rate, gain, breakdown voltage and correlated noise of the SiPMs are measured, while the LYSO crystals are evaluated in terms of light yield and en...

  6. Relative bioavailability of single doses of prolonged-release tacrolimus administered as a suspension, orally or via a nasogastric tube, compared with intact capsules: a phase 1 study in healthy participants.

    Science.gov (United States)

    Undre, Nasrullah; Dickinson, James

    2017-04-04

    Tacrolimus, an immunosuppressant widely used in solid organ transplantation, is available as a prolonged-release capsule for once-daily oral administration. In the immediate postsurgical period, if patients cannot take intact capsules orally, tacrolimus therapy is often initiated as a suspension of the capsule contents, delivered orally or via a nasogastric tube. This study evaluated the relative bioavailability of prolonged-release tacrolimus suspension versus intact capsules in healthy participants. A phase 1, open-label, single-dose, cross-over study. A single clinical research unit. In total, 20 male participants, 18-55 years old, entered and completed the study. All participants received nasogastric administration of tacrolimus 10 mg suspension in treatment period 1, with randomisation to oral administration of suspension or intact capsules in periods 2 and 3. Blood concentration-time profile over 144 hours was used to estimate pharmacokinetic parameters. Primary end point: relative bioavailability of prolonged-release intact capsule versus oral or nasogastric administration of prolonged-release tacrolimus suspension (area under the concentration-time curve (AUC) from time 0 to infinity post-tacrolimus dose (AUC 0-∞ ); AUC measured until the last quantifiable concentration (AUC 0-tz ); maximum observed concentration (C max ); time to C max (T max )). Tolerability was assessed throughout the study. Relative bioavailability of prolonged-release tacrolimus suspension administered orally was similar to intact capsules, with a ratio of least-square means for AUC 0-tz and AUC 0-∞ of 1.05 (90% CI 0.96 to 1.14). Bioavailability was lower with suspension administered via a nasogastric tube versus intact capsules (17%; ratio 0.83; CI 0.76 to 0.92). C max was higher for oral and nasogastric suspension (30% and 28%, respectively), and median T max was shorter (difference 1.0 and 1.5 hours postdose, respectively) versus intact capsules (2.0 hours). Single 10

  7. Single-tube genotyping using a solid-phase method that combines alpha-phosphorothioate-mediated primer extension and ExoIII: proof of concept with the F508del cystic fibrosis diagnosis.

    Science.gov (United States)

    Brugère, Jean-François; Gobron, Stéphane; Baud, Eric; Cailloux, Fabrice

    2008-01-01

    Detection of single nucleotide polymorphisms (SNPs) and of mutations is of importance in the field of genetics, biomedical research and in vitro diagnosis. We report here a genotyping procedure that can be virtually applied to any locus within a genome: it uses alpha-phosphorothioate deoxynucleotides in a primer-extension step followed by an ExoIII treatment. Non-extended primers are hydrolyzed whereas extended primers resist this treatment, indicating which nucleotide has been incorporated, i.e. the genotype of the locus. A 3-bp deletion in the CFTR gene (F508del, the most prevalent mutation involved in cystic fibrosis) was used as a model, in a single-tube procedure for each nucleotide to be tested. Human genomic DNA samples were correctly genotyped in less than 3h by a solid-phase PCR followed by primer extension, ExoIII treatment and an ELISA-like detection method. The same principle (primer extension with alpha-phosphorothioate deoxynucleotide, ExoIII treatment) should also be combined with other detection systems such as gel or capillary electrophoresis, mass spectrometry or DNA chips.

  8. Multiplex Nested Reverse Transcription-Polymerase Chain Reaction in a Single Tube for Sensitive and Simultaneous Detection of Four RNA Viruses and Pseudomonas savastanoi pv. savastanoi in Olive Trees.

    Science.gov (United States)

    Bertolini, Edson; Olmos, Antonio; López, María M; Cambra, Mariano

    2003-03-01

    ABSTRACT A multiplex nested reverse transcription-polymerase chain reaction (RT-PCR) in a single closed tube was developed for the simultaneous detection of four RNA viruses: Cucumber mosaic virus, Cherry leaf roll virus, Strawberry latent ringspot virus, and Arabis mosaic virus, and the bacterium Pseudomonas savastanoi pv. savastanoi. The method enabled, for the first time, the sensitive and simultaneous detection of RNA and DNA targets from plant viruses and a bacterium, saving time, decreasing risks of contamination, and reducing costs compared with conventional monospecific nested amplifications. The method was successfully coupled with colorimetric detection of amplicons using specific oligoprobes to simplify routine detection. Two hundred forty-five olive trees from 15 different cultivars were analyzed by multiplex RT-nested PCR coupled with colorimetric detection. Multiplex nested RT-PCR for viral detection increased the identification of positive trees by 8.1%. An uneven distribution of the viruses was observed in the infected trees. The bacterium was detected in 28.7% of the analyzed trees by the developed multiplex nested method and by a nested PCR previously developed. This powerful methodology could be applied to other models for the detection of several pathogens in a single assay.

  9. Tracheostomy tube - speaking

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000465.htm Tracheostomy tube - speaking To use the sharing features on ... are even speaking devices that can help you. Tracheostomy Tubes and Speaking Air passing through vocal cords ( ...

  10. X-ray tubes

    International Nuclear Information System (INIS)

    Young, R.W.

    1979-01-01

    A form of x-ray tube is described which provides satisfactory focussing of the electron beam when the beam extends for several feet from gun to target. Such a tube can be used for computerised tomographic scanning. (UK)

  11. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

  12. Jejunostomy feeding tube

    Science.gov (United States)

    ... may replace the tube every now and then. Cleaning the Skin Around the J-tube To clean ... this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial ...

  13. Impact of long-pass interferential filters on dark current and background light rejection in Silicon Photomultipliers

    Science.gov (United States)

    Mazzillo, M.; Sciuto, A.; Libertino, S.; Lombardo, S.; Fallica, G.

    2018-02-01

    There is an increasing interest in using Silicon Photomultipliers (SiPMs) in emerging applications where the detectors have to operate in ambient environment with high sensitivity and fast timing response in combination with narrow bandwidth light emitting sources like LEDs or VCSELs. The need to use large area detectors for optimizing the light collection efficiency, due to the low optical fluxes to be usually detected, imposes the optimization of the SiPM performance in specific wavelength ranges (usually visible or near infrared), to fully exploit the single photon sensitivity of these detectors and not to reduce at the same time their dynamic range. The use of proper optical long-pass filters on the detector's package can represent a suitable way to reach both these targets, through the reduction of environmental light absorption. Here we present the preliminary results obtained from the characterization of n+-p SiPMs with commercial long-pass filters with increasing cut-on wavelength in the range 500 nm-900 nm glued on the top side of the detector's package. The performance of the detectors has been evaluated in terms of dark current variation induced by the use of the filters and background light rejection under the illumination of white fluorescent lamps. The relevant reduction observed in the dark current (up to 90% at 13 V overvoltage) and the consistent reduction of stray light absorption (up to 90% at 3 V overvoltage with a 900 nm cut-on wavelength long-pass filter) are the main characterization results obtained and shown in this paper.

  14. Nasogastric and feeding tubes.

    Science.gov (United States)

    Gharib, Ahmed M; Stern, Eric J; Sherbin, Vandy L; Rohrmann, Charles A

    1996-05-01

    Preview The authors' experience in a radiology department suggested to them that there is a wide range of beliefs among practitioners regarding proper placement of nasogastric and feeding tubes. Improper positioning can cause serious problems, as they explain. Indications for different tube positions, complications of incorrect tube placement, and directions for proper positioning are discussed and illustrated.

  15. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into a...

  16. Short and long range gain monitoring of photomultipliers by means of a light pulser and an optical fibers bunch

    International Nuclear Information System (INIS)

    Besson, P.

    1989-01-01

    The gain monitoring of 8 XP3462 photomultipliers has been studied during a period of 3 months with a spark gap as a light pulser, an optical fibres bunch and 3 reference detectors. One of the reference PM is monitored thanks to a cristal of NaI irradiated by an 241 Am radioactive source, whereas the photodiode and its associated electronic is monitored thanks to a 57 Co source directly coupled to the junction. Two experimental methods have been tested. First the short term method consists in estimating several means of charge distributions and supposes the stability of different optical parameters like quantum efficiency or photoelectrons collection efficiency. The long term method consists in estimating several variances of charge distributions and supposes the validity, at first order, of photomultipliers' equations. In spite of unpropitious experimental conditions (tension switch off, no climatisation..), our results indicate that the short term method provides a precision of about 0.5% for the relative gain value but only during a short period which has been of 20 days. The long term method provides a precision of about 1.5% but is remained available during the 3 months of our experiment. This study has been developed for the new Neutrino oscillation program taking place near the Bugey nuclear plant and using 600 photomultipliers. The conclusions mentioned above are nevertheless valid for any particle detectors using photomultipliers [fr

  17. The Strip Silicon Photo-Multiplier: An innovation for enhanced time and position measurement

    Energy Technology Data Exchange (ETDEWEB)

    Doroud, K., E-mail: Katayoun.Doroud@cern.ch [CERN, Geneva (Switzerland); Williams, M.C.S. [CERN, Geneva (Switzerland); INFN, Bologna (Italy); Yamamoto, K. [Solid State Division, Hamamatsu Photonics K.K., Hamamatsu (Japan)

    2017-05-01

    There is considerable R&D concerning precise time measurement from a variety of detectors, and in particular for the Silicon PhotoMultiplier (SiPM). In this paper we discuss a new geometry for the SiPM in the form of a strip. A strip can be read out at both end, with each end coupled to an individual TDC (time to digital converter). The time difference is related to the position of the firing SPAD along the length of the strip, while the average of the two times gives the time of the hit. Results from the testing of the first prototype Strip SiPMs are presented in this paper.

  18. Compact Quantum Random Number Generator with Silicon Nanocrystals Light Emitting Device Coupled to a Silicon Photomultiplier

    Science.gov (United States)

    Bisadi, Zahra; Acerbi, Fabio; Fontana, Giorgio; Zorzi, Nicola; Piemonte, Claudio; Pucker, Georg; Pavesi, Lorenzo

    2018-02-01

    A small-sized photonic quantum random number generator, easy to be implemented in small electronic devices for secure data encryption and other applications, is highly demanding nowadays. Here, we propose a compact configuration with Silicon nanocrystals large area light emitting device (LED) coupled to a Silicon photomultiplier to generate random numbers. The random number generation methodology is based on the photon arrival time and is robust against the non-idealities of the detector and the source of quantum entropy. The raw data show high quality of randomness and pass all the statistical tests in national institute of standards and technology tests (NIST) suite without a post-processing algorithm. The highest bit rate is 0.5 Mbps with the efficiency of 4 bits per detected photon.

  19. Characteristics of a prototype matrix of Silicon PhotoMultipliers (SiPM)

    Energy Technology Data Exchange (ETDEWEB)

    Dinu, N; Barrillon, P; Bazin, C; Bondil-Blin, S; Chaumat, V; Taille, C De La; Puill, V; Vagnucci, J F [Laboratory of Linear Accelerator (LAL), IN2P3-CNRS, 91898 Orsay (France); Belcari, N; Bisogni, M G; Guerra, A Del; Llosa, G; Marcatili, S [Universita di Pisa, Dipartimento di Fisica ' E. Fermi' , 56127 Pisa (Italy); Boscardin, M; Melchiorri, M; Piemonte, C; Tarolli, A; Zorzi, N [Fondazione Bruno Kessler (FBK-irst), 38050 Trento (Italy); Collazuol, G [Scuola Normale Superiore (SNS), 56127 Pisa (Italy)], E-mail: dinu@lal.in2p3.fr

    2009-03-15

    This work reports on the electrical (static and dynamic) as well as on the optical characteristics of a prototype matrix of Silicon Photomultipliers (SiPM). The prototype matrix consists of 4 x 4 SiPM's on the same substrat fabricated at FBK-irst (Trento, Italy). Each SiPM of the matrix has an area of 1 x 1mm{sup 2} and it is composed of 625 microcells connected in parallel. Each microcell of the SiPM is a GM-APD (n{sup +}/p junction on P+ substrate) with an area of 40 x 40 {mu}m{sup 2} connected in series with its integrated polysilicon quenching resistance. The static characteristics as breakdown voltage, quenching resistance, post-breakdown dark current as well as the dynamic characteristics as gain and dark count rate have been analysed. The photon detection efficiency as a function of wavelength and operation voltage has been also estimated.

  20. First results in the application of silicon photomultiplier matrices to small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Llosa, G. [University of Pisa, Department of Physics, Pisa (Italy)], E-mail: gabriela.llosa@pi.infn.it; Belcari, N.; Bisogni, M.G. [University of Pisa, Department of Physics, Pisa (Italy); INFN Pisa (Italy); Collazuol, G. [University of Pisa, Department of Physics, Pisa (Italy); Scuola Normale Superiore, Pisa (Italy); Marcatili, S. [University of Pisa, Department of Physics, Pisa (Italy); INFN Pisa (Italy); Boscardin, M.; Melchiorri, M.; Tarolli, A.; Piemonte, C.; Zorzi, N. [FBK irst, Trento (Italy); Barrillon, P.; Bondil-Blin, S.; Chaumat, V.; La Taille, C. de; Dinu, N.; Puill, V.; Vagnucci, J-F. [Laboratoire de l' Accelerateur Lineaire, IN2P3-CNRS, Orsay (France); Del Guerra, A. [University of Pisa, Department of Physics, Pisa (Italy); INFN Pisa (Italy)

    2009-10-21

    A very high resolution small animal PET scanner that employs matrices of silicon photomultipliers as photodetectors is under development at the University of Pisa and INFN Pisa. The first SiPM matrices composed of 16 (4x4)1mmx1mm pixel elements on a common substrate have been produced at FBK-irst, and are being evaluated for this application. The MAROC2 ASIC developed at LAL-Orsay has been employed for the readout of the SiPM matrices. The devices have been tested with pixelated and continuous LYSO crystals. The results show the good performance of the matrices and lead to the fabrication of matrices with 64 SiPM elements.

  1. Development of large-area silicon photomultiplier detectors for PET applications at FBK

    Energy Technology Data Exchange (ETDEWEB)

    Zorzi, Nicola, E-mail: zorzi@fbk.eu [Fondazione Bruno Kessler (FBK), Via Sommarive 18, I-38123 Trento Povo (Italy); Melchiorri, Mirko; Piazza, Alessandro; Piemonte, Claudio; Tarolli, Alessandro [Fondazione Bruno Kessler (FBK), Via Sommarive 18, I-38123 Trento Povo (Italy)

    2011-04-21

    This paper reports on the development of large-area silicon photomultiplier (SiPM) detectors specifically designed for positron emission tomography (PET) instruments. The sensors under study are monolithic arrays of two different types: a 2x2 array of {approx}4x4 mm{sup 2} elements and an 8x8 array of 1.5x1.5 mm{sup 2} pixels. These devices are characterized at wafer level by means of an automatic test procedure, consisting of current-voltage curves in forward and reverse bias. The tests allowed selection of functioning devices and evaluation of the uniformity of basic parameters. Results of the electrical characterization are reported showing that acceptable values of yield together with rather uniform distribution of parameters have been obtained. Reliability of produced SiPMs has been proved by long-term accelerated stress tests.

  2. First results in the application of silicon photomultiplier matrices to small animal PET

    International Nuclear Information System (INIS)

    Llosa, G.; Belcari, N.; Bisogni, M.G.; Collazuol, G.; Marcatili, S.; Boscardin, M.; Melchiorri, M.; Tarolli, A.; Piemonte, C.; Zorzi, N.; Barrillon, P.; Bondil-Blin, S.; Chaumat, V.; La Taille, C. de; Dinu, N.; Puill, V.; Vagnucci, J-F.; Del Guerra, A.

    2009-01-01

    A very high resolution small animal PET scanner that employs matrices of silicon photomultipliers as photodetectors is under development at the University of Pisa and INFN Pisa. The first SiPM matrices composed of 16 (4x4)1mmx1mm pixel elements on a common substrate have been produced at FBK-irst, and are being evaluated for this application. The MAROC2 ASIC developed at LAL-Orsay has been employed for the readout of the SiPM matrices. The devices have been tested with pixelated and continuous LYSO crystals. The results show the good performance of the matrices and lead to the fabrication of matrices with 64 SiPM elements.

  3. Compact Quantum Random Number Generator with Silicon Nanocrystals Light Emitting Device Coupled to a Silicon Photomultiplier

    Directory of Open Access Journals (Sweden)

    Zahra Bisadi

    2018-02-01

    Full Text Available A small-sized photonic quantum random number generator, easy to be implemented in small electronic devices for secure data encryption and other applications, is highly demanding nowadays. Here, we propose a compact configuration with Silicon nanocrystals large area light emitting device (LED coupled to a Silicon photomultiplier to generate random numbers. The random number generation methodology is based on the photon arrival time and is robust against the non-idealities of the detector and the source of quantum entropy. The raw data show high quality of randomness and pass all the statistical tests in national institute of standards and technology tests (NIST suite without a post-processing algorithm. The highest bit rate is 0.5 Mbps with the efficiency of 4 bits per detected photon.

  4. Development of large-area silicon photomultiplier detectors for PET applications at FBK

    International Nuclear Information System (INIS)

    Zorzi, Nicola; Melchiorri, Mirko; Piazza, Alessandro; Piemonte, Claudio; Tarolli, Alessandro

    2011-01-01

    This paper reports on the development of large-area silicon photomultiplier (SiPM) detectors specifically designed for positron emission tomography (PET) instruments. The sensors under study are monolithic arrays of two different types: a 2x2 array of ∼4x4 mm 2 elements and an 8x8 array of 1.5x1.5 mm 2 pixels. These devices are characterized at wafer level by means of an automatic test procedure, consisting of current-voltage curves in forward and reverse bias. The tests allowed selection of functioning devices and evaluation of the uniformity of basic parameters. Results of the electrical characterization are reported showing that acceptable values of yield together with rather uniform distribution of parameters have been obtained. Reliability of produced SiPMs has been proved by long-term accelerated stress tests.

  5. Time characteristics of detectors based on silicon photomultipliers for the GlueX experiment

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, F. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Somov, A. S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Somov, S. V. [National Research Nuclear Univ., Moscow (Russia); Tolstukhin, I. A. [National Research Nuclear Univ., Moscow (Russia); Indiana Univ., Bloomington, IN (United States)

    2017-06-16

    Here, silicon photomultipliers (SiPMs) are used in detectors of the GlueX experiment devoted to studying the nature of confinement. These detectors are operable at counting rates as high as 2 MHz with a time resolution (FWHM) of approximately 0.3 ns and a number of excited pixels of up to 104. For SiPMs that operate under these conditions, the measured dependences of the recovery time and the time resolution are presented as functions of the number of excited pixels and the excitation frequency. Using a picosecond laser, the time resolution has been measured for an array of 4 × 4 SiPMs, which was specially developed for the experiment.

  6. Gain monitoring of telescope array photomultiplier cameras for the first 4 years of operation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, B.K., E-mail: bkshin@hanyang.ac.kr [Hanyang University, Seongdong-gu, Seoul (Korea, Republic of); Tokuno, H.; Tsunesada, Y. [Tokyo Institute of Technology, Meguro, Tokyo (Japan); Abu-Zayyad, T. [University of Utah, High Energy Astrophysics Institute, Salt Lake City, UT (United States); Aida, R. [University of Yamanashi, Interdisciplinary Graduate School of Medicine and Engineering, Kofu, Yamanashi (Japan); Allen, M.; Anderson, R. [University of Utah, High Energy Astrophysics Institute, Salt Lake City, UT (United States); Azuma, R. [Tokyo Institute of Technology, Meguro, Tokyo (Japan); Barcikowski, E.; Belz, J.W.; Bergman, D.R.; Blake, S.A.; Cady, R. [University of Utah, High Energy Astrophysics Institute, Salt Lake City, UT (United States); Cheon, B.G., E-mail: bgcheon@hanyang.ac.kr [Hanyang University, Seongdong-gu, Seoul (Korea, Republic of); Chiba, J. [Tokyo University of Science, Noda, Chiba (Japan); Chikawa, M. [Kinki University, Higashi Osaka, Osaka (Japan); Cho, E.J. [Hanyang University, Seongdong-gu, Seoul (Korea, Republic of); Cho, W.R. [Yonsei University, Seodaemun-gu, Seoul (Korea, Republic of); Fujii, H. [Institute of Particle and Nuclear Studies, KEK, Tsukuba, Ibaraki (Japan); Fujii, T. [Osaka City University, Osaka, Osaka (Japan); and others

    2014-12-21

    The stability of the gain of the photomultiplier (PMT) camera for the Fluorescence Detector (FD) of the Telescope Array experiment was monitored using an {sup 241}Am loaded scintillator pulsers (YAP) and a diffused xenon flasher (TXF) for a selected set of 35 PMT-readout channels. From the monitoring of YAP pulses over four years of FD operation, we found slow monotonic drifts of PMT gains at a rate of −1.7∼+1.7%/year. An average of the PMT gains over the 35 channels stayed nearly constant with a rate of change measured at −0.01±0.31(stat)±0.21(sys)%/year. No systematic decrease of the PMT gain caused by the night sky background was observed. Monitoring by the TXF also tracked the PMT gain drift of the YAP at 0.88±0.14(stat)%/year.

  7. Ultrafast Readout of Scintillating Fibres Using Upgraded Position-Sensitive Photomultipliers

    CERN Multimedia

    2002-01-01

    % RD-17 \\\\ \\\\To design a high rate topological trigger device for the future DIRAC Experiment at CERN an extensive work is in progress on a scintillating-fibre detector using a position-sensitive photomultiplier. Several detector prototypes with different lengths ($<$~50~cm) of sensitive area have been tested at T7S~PS beam. \\\\ \\\\With 0.5~mm diameter fibres a spatial resolution of $\\sim$125~$\\mu$m was obtained with a detection efficiency higher than 95\\%. The time resolution is $\\sim$600~ps, and the track position is properly digitized in real time (about 10~ns) by multi-channel peak sensing circuit. Based on experimental data simulations were also performed a comparison of different types of front-end electronics for multi-channel readout.

  8. The STiC ASIC. High precision timing with silicon photomultipliers

    International Nuclear Information System (INIS)

    Harion, Tobias

    2015-01-01

    In recent years, Silicon Photomultipliers are being increasingly used for Time of Flight measurements in particle detectors. To utilize the high intrinsic time resolution of these sensors in detector systems, the development of specialized, highly integrated readout electronics is required. In this thesis, a mixed-signal application specific integrated circuit, named STiC, has been developed, characterized and integrated in a detector system. STiC has been specifically designed for high precision timing measurements with SiPMs, and is in particular dedicated to the EndoTOFPET-US project, which aims to achieve a coincidence time resolution of 200 ps FWHM and an energy resolution of less than 20% in an endoscopic positron emission tomography system. The chip integrates 64 high precision readout channels for SiPMs together with a digital core logic to process, store and transfer the recorded events to a data acquisition system. The performance of the chip has been validated in coincidence measurements using detector modules consisting of 3.1 x 3.1 x 15 mm 3 LYSO crystals coupled to Silicon Photomultipliers from Hamamatsu. The measurements show an energy resolution of 15% FWHM for the detection of 511 keV photons. A coincidence time resolution of 213 ps FWHM has been measured, which is among the best resolution values achieved to date with this detector topology. STiC has been integrated in the EndoTOFPET-US detector system and has been chosen as the baseline design for the readout of SiPM sensors in the Mu3e experiment.

  9. Performance of single mechanoluminescent particle as ubiquitous light source.

    Science.gov (United States)

    Terasaki, Nao; Xu, Chao-Nan

    2014-08-01

    In this study, we have investigated mechanoluminescent (ML) performance of single ML particle as ubiquitous light source. When using high-speed CCD camera with image intensifier and microscopic equipment, mechanoluminescence from single particle was observed. As to the quantitative ML evaluation of the single ML particle was carried out using photomultiplier, and successfully estimated the performance of the single ML particle as an intensity controllable light source in nW order. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos >> NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: ...

  11. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia ... of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia ...

  12. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: ...

  13. Effect of Blood Collection Tube Type and Time to Processing on the Enumeration and High-Content Characterization of Circulating Tumor Cells Using the High-Definition Single-Cell Assay.

    Science.gov (United States)

    Rodríguez-Lee, Mariam; Kolatkar, Anand; McCormick, Madelyn; Dago, Angel D; Kendall, Jude; Carlsson, Nils Anders; Bethel, Kelly; Greenspan, Emily J; Hwang, Shelley E; Waitman, Kathryn R; Nieva, Jorge J; Hicks, James; Kuhn, Peter

    2018-02-01

    - As circulating tumor cell (CTC) assays gain clinical relevance, it is essential to address preanalytic variability and to develop standard operating procedures for sample handling in order to successfully implement genomically informed, precision health care. - To evaluate the effects of blood collection tube (BCT) type and time-to-assay (TTA) on the enumeration and high-content characterization of CTCs by using the high-definition single-cell assay (HD-SCA). - Blood samples of patients with early- and advanced-stage breast cancer were collected into cell-free DNA (CfDNA), EDTA, acid-citrate-dextrose solution, and heparin BCTs. Time-to-assay was evaluated at 24 and 72 hours, representing the fastest possible and more routine domestic shipping intervals, respectively. - We detected the highest CTC levels and the lowest levels of negative events in CfDNA BCT at 24 hours. At 72 hours in this BCT, all CTC subpopulations were decreased with the larger effect observed in high-definition CTCs and cytokeratin-positive cells smaller than white blood cells. Overall cell retention was also optimal in CfDNA BCT at 24 hours. Whole-genome copy number variation profiles were generated from single cells isolated from all BCT types and TTAs. Cells from CfDNA BCT at 24-hour TTA exhibited the least noise. - Circulating tumor cells can be identified and characterized under a variety of collection, handling, and processing conditions, but the highest quality can be achieved with optimized conditions. We quantified performance differences of the HD-SCA for specific preanalytic variables that may be used as a guide to develop best practices for implementation into patient care and/or research biorepository processes.

  14. Curvature and position of nested tubes in hollow-core anti-resonant fibers

    DEFF Research Database (Denmark)

    Habib, Md Selim; Markos, Christos; Bang, Ole

    2017-01-01

    ], especially when smaller tubes are “nested” inside the larger tubes [2, 3]. Here we investigate the role of curvature and position of the nested tube and we show that the position of the nested tube has a much more pronounced effect compared to the curvature on the overall performance and single...

  15. Tube vibration in industrial size test heat exchanger

    International Nuclear Information System (INIS)

    Halle, H.; Wambsganss, M.W.

    1980-03-01

    Tube vibration data from tests of a specially built and instrumented, industrial-type, shell-and-tube heat exchanger are reported. The heat exchanger is nominally 0.6 m (2 ft) in dia and 3.7 m (12 ft) long. Both full tube and no-tubes-in-window bundles were tested for inlet/outlet nozzles of different sizes and with the tubes supported by seven, equally-spaced, single-segmental baffles. Prior to water flow testing, natural frequencies and damping of representative tubes were measured in air and water. Flow testing was accomplished by increasing the flow rates in stepwise fashion and also by sweeping through a selected range of flow rates. The primary variables measured and reported are tube accelerations and/or displacements and pressure drop through the bundle. Tests of the full tube bundle configuration revealed tube rattling to occur at intermediate flow rates, and fluidelastic instability, with resultant tube impacting, to occur when the flow rate exceeded a threshold level; principally, the four-span tubes were involved in the regions immediately adjacent to the baffle cut. For the range of flow rates tested, fluidelastic instability was not achieved in the no-tubes-in-window bundle; in this configuration the tubes are supported by all seven baffles and are, therefore, stiffer

  16. Statistics of multi-tube detecting systems

    International Nuclear Information System (INIS)

    Grau Carles, P.; Grau Malonda, A.

    1994-01-01

    In this paper three new statistical theorems are demonstrated and applied. These theorems simplify very much the obtention of the formulae to compute the counting efficiency when the detection system is formed by several photomultipliers associated in coincidence and sume. These theorems are applied to several photomultiplier arrangements in order to show their potential and the application. way

  17. Statistics of multi-tube detecting systems

    International Nuclear Information System (INIS)

    Grau Carles, P.; Grau Malonda, A.

    1994-01-01

    In this paper three new statistical theorems are demonstrated and applied. These theorems simplify very much the obtention of the formulae to compute the counting efficiency when the detection system is formed by several photomultipliers associated in coincidence and sum. These theorems are applied to several photomultiplier arrangements in order to show their potential and the application way. (Author) 6 refs

  18. Hydrogen isotope exchange in a metal hydride tube

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, David B. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2014-09-01

    This report describes a model of the displacement of one hydrogen isotope within a metal hydride tube by a different isotope in the gas phase that is blown through the tube. The model incorporates only the most basic parameters to make a clear connection to the theory of open-tube gas chromatography, and to provide a simple description of how the behavior of the system scales with controllable parameters such as gas velocity and tube radius. A single tube can be seen as a building block for more complex architectures that provide higher molar flow rates or other advanced design goals.

  19. Lunar Lava Tube Sensing

    Science.gov (United States)

    York, Cheryl Lynn; Walden, Bryce; Billings, Thomas L.; Reeder, P. Douglas

    1992-01-01

    Large (greater than 300 m diameter) lava tube caverns appear to exist on the Moon and could provide substantial safety and cost benefits for lunar bases. Over 40 m of basalt and regolith constitute the lava tube roof and would protect both construction and operations. Constant temperatures of -20 C reduce thermal stress on structures and machines. Base designs need not incorporate heavy shielding, so lightweight materials can be used and construction can be expedited. Identification and characterization of lava tube caverns can be incorporated into current precursor lunar mission plans. Some searches can even be done from Earth. Specific recommendations for lunar lava tube search and exploration are (1) an Earth-based radar interferometer, (2) an Earth-penetrating radar (EPR) orbiter, (3) kinetic penetrators for lunar lava tube confirmation, (4) a 'Moon Bat' hovering rocket vehicle, and (5) the use of other proposed landers and orbiters to help find lunar lava tubes.

  20. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1983-08-01

    A review of the performance of steam generator tubes in 110 water-cooled nuclear power reactors showed that tubes were plugged at 46 (42 percent) of the reactors. The number of tubes removed from service increased from 1900 (0.14 percent) in 1980 to 4692 (0.30 percent) in 1981. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that used all-volatile treatment since start-up. At one reactor a large number of degraded tubes were repaired by sleeving which is expected to become an important method of tube repair in the future

  1. Manual tube welding torch

    International Nuclear Information System (INIS)

    Kiefer, J.H.; Smith, D.J.

    1981-01-01

    In a welding torch which fits over a tube intermediate the ends thereof for welding the juncture between the tube and a boss on the back side of a tube plate, a split housing encloses a tungsten electrode, a filler wire duct and a fiber optic bundle arranged to observe the welding process. A shielding gas duct is provided in the housing. A screw is provided for setting electrode/work distance. Difficult remote tube welding operations can be performed with the apparatus. (author)

  2. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1984-10-01

    A review of the performance of steam generator tubes in 116 water-cooled nuclear power reactors showed that tubes were plugged at 54 (46 percent) of the reactors. The number of tubes removed from service decreased from 4 692 (0.30 percent) in 1981 to 3 222 (0.20 percent) in 1982. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that have used only volatile treatment, with or without condensate demineralization

  3. Wound tube heat exchanger

    Science.gov (United States)

    Ecker, Amir L.

    1983-01-01

    What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

  4. Sapphire tube pressure vessel

    Science.gov (United States)

    Outwater, John O.

    2000-01-01

    A pressure vessel is provided for observing corrosive fluids at high temperatures and pressures. A transparent Teflon bag contains the corrosive fluid and provides an inert barrier. The Teflon bag is placed within a sapphire tube, which forms a pressure boundary. The tube is received within a pipe including a viewing window. The combination of the Teflon bag, sapphire tube and pipe provides a strong and inert pressure vessel. In an alternative embodiment, tie rods connect together compression fittings at opposite ends of the sapphire tube.

  5. Fuel nozzle tube retention

    Energy Technology Data Exchange (ETDEWEB)

    Cihlar, David William; Melton, Patrick Benedict

    2017-02-28

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  6. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  7. Steam generator tube failures

    International Nuclear Information System (INIS)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

  8. A one-step, triplex, real-time RT-PCR assay for the simultaneous detection of enterovirus 71, coxsackie A16 and pan-enterovirus in a single tube.

    Science.gov (United States)

    Zhang, Shiyin; Wang, Jin; Yan, Qiang; He, Shuizhen; Zhou, Wenbin; Ge, Shengxiang; Xia, Ningshao

    2014-01-01

    The recent, ongoing epidemic of hand, foot, and mouth disease (HFMD), which is caused by enterovirus infection, has affected millions of children and resulted in thousands of deaths in China. Enterovirus 71 (EV71) and coxsackie A16 (CA16) are the two major distinct pathogens for HFMD. However, EV71 is more commonly associated with neurologic complications and even fatalities. Therefore, simultaneously detecting and differentiating EV71 and CA16 specifically from other enteroviruses for diagnosing HFMD is important. Here, we developed a one-step, triplex, real-time RT-PCR assay for the simultaneous detection of EV71, CA16, and pan-enterovirus (EVs) in a single tube with an internal amplification control. The detection results for the serially diluted viruses indicate that the lower limit of detection for this assay is 0.001-0.04 TCID50/ml, 0.02 TCID50/ml, and 0.001 TCID50/ml for EVs, EV71, and CA16, respectively. After evaluating known HFMD virus stocks of 17 strains of 16 different serotypes, this assay showed a favorable detection spectrum and no obvious cross-reactivity. The results for 141 clinical throat swabs from HFMD-suspected patients demonstrated sensitivities of 98.4%, 98.7%, and 100% for EVs, EV71, and CA16, respectively, and 100% specificity for each virus. The application of this one-step, triplex, real-time RT-PCR assay in clinical units will contribute to HFMD surveillance and help to identify causative pathogen in patients with suspected HFMD.

  9. A one-step, triplex, real-time RT-PCR assay for the simultaneous detection of enterovirus 71, coxsackie A16 and pan-enterovirus in a single tube.

    Directory of Open Access Journals (Sweden)

    Shiyin Zhang

    Full Text Available The recent, ongoing epidemic of hand, foot, and mouth disease (HFMD, which is caused by enterovirus infection, has affected millions of children and resulted in thousands of deaths in China. Enterovirus 71 (EV71 and coxsackie A16 (CA16 are the two major distinct pathogens for HFMD. However, EV71 is more commonly associated with neurologic complications and even fatalities. Therefore, simultaneously detecting and differentiating EV71 and CA16 specifically from other enteroviruses for diagnosing HFMD is important. Here, we developed a one-step, triplex, real-time RT-PCR assay for the simultaneous detection of EV71, CA16, and pan-enterovirus (EVs in a single tube with an internal amplification control. The detection results for the serially diluted viruses indicate that the lower limit of detection for this assay is 0.001-0.04 TCID50/ml, 0.02 TCID50/ml, and 0.001 TCID50/ml for EVs, EV71, and CA16, respectively. After evaluating known HFMD virus stocks of 17 strains of 16 different serotypes, this assay showed a favorable detection spectrum and no obvious cross-reactivity. The results for 141 clinical throat swabs from HFMD-suspected patients demonstrated sensitivities of 98.4%, 98.7%, and 100% for EVs, EV71, and CA16, respectively, and 100% specificity for each virus. The application of this one-step, triplex, real-time RT-PCR assay in clinical units will contribute to HFMD surveillance and help to identify causative pathogen in patients with suspected HFMD.

  10. Longitudinally excited CO2 laser with multiple laser tubes

    Science.gov (United States)

    Uno, Kazuyuki; Akitsu, Tetsuya; Jitsuno, Takahisa

    2016-11-01

    We developed a longitudinally excited CO2 laser system that was constituted of two or three laser tubes and a single driving circuit. The multiple laser tubes simultaneously produced almost the same short laser pulses with a spike pulse width of about 164 ns and a pulse tail length of about 74 μs with a single driving circuit. The double-tube system was constituted of two 30 cm-long laser tubes with inner diameters of 13 mm and 16 mm and a single driving circuit with an input energy of 2.18 J. The output energy of the 13 mm-tube was 23.3 mJ, and that of the 16 mm-tube was 21.9 mJ at a gas pressure of 4.2 kPa (CO2:N2:He = 1:1:2). The triple-tube system was constituted of three 30 cm-long laser tubes with inner diameters of 9 mm, 13 mm, and 16 mm and a single driving circuit with an input energy of 2.18 J. The output energy of the 9 mm tube was 15.9 mJ, that of the 13 mm tube was 24.1 mJ, and that of the 16 mm tube was 19.2 mJ at a gas pressure of 4.2 kPa. With the same driving circuit and the same input energy, the total output energies of the multitube laser systems were higher than the output energy of a single-tube system.

  11. Early Experience with the StopLoss Jones Tube.

    Science.gov (United States)

    Bagdonaite, Laura; Pearson, Andrew R

    2015-06-01

    Extrusion is the most common reason for failure after Jones tube placement. The StopLoss Jones tube (SLJT) is a new innovation in Jones tubes that incorporates a flexible silicone internal flange to resist extrusion. We present our early experience of using this new tube and associated introducer system. We retrospectively analysed the case notes of a single surgeon consecutive series of patients having SLJT placement from November 2011 to November 2013. 29 SLJTs were placed in 25 eyes of 19 patients. Tube follow-up ranged from 1-25 months (mean 10 months) with a total of 291 tube-months. The indications for SLJT placement were: previous LJT complications (52%), failed canalicular-DCR surgery (31%), primary placement for inoperable canalicular occlusion (14%) and patent non-functioning DCR (3%). Tube length ranged from 10-16 mm. The tube introducer system was simple and effective and there were no intra-operative complications. The tube extrusion rate was 0%. Complications occurred in 5 tubes: 1 was too long, and 4 others (14%) developed conjunctival overgrowth/medial tube migration. Patient satisfaction with the tube was: 86% fully satisfied, 10% was moderately satisfied, 3% not satisfied. The overall final surgical success rate at last follow-up was 92%. In this short follow-up initial study the SLJT is simple to use and has a high rate of success and patient satisfaction. The addition of the internal silicone flange appears to prevent the previously common problem of extrusion.

  12. Chest Tube Thoracostomy

    Science.gov (United States)

    ... in the space around the lungs (called a pleural effusion) . A chest tube may also be needed when a patient has ... or chest CT are also done to evaluate pleural fluid. If the X-ray shows a need for a chest tube to drain fluid or air, the procedure is ...

  13. Ventricular tachycardia following tube thoracotomy.

    Science.gov (United States)

    Hibbert, Benjamin; Lim, Toon Wei; Hibbert, Rebecca; Green, Martin; Gollob, Michael H; Davis, Darryl R

    2010-10-01

    Arrhythmias provoked by tube thoracotomy are a rare complication. We report a ventricular tachycardia after chest tube insertion for a device-related pneumothorax. Sinus rhythm was restored only by removal of the chest tube and insertion of a pliable pleural drain. Identification of the chest tube as an arrhythmic trigger following tube thoracotomy is essential in definitive management of refractory arrhythmias.

  14. Pulsed Drift Tube Accelerator

    International Nuclear Information System (INIS)

    Faltens, A.

    2004-01-01

    The pulsed drift-tube accelerator (DTA) concept was revived by Joe Kwan and John Staples and is being considered for the HEDP/WDM application. It could be used to reach the full energy or as an intermediate accelerator between the diode and a high gradient accelerator such as multi-beam r.f. In the earliest LBNL HIF proposals and conceptual drivers it was used as an extended injector to reach energies where an induction linac with magnetic quadrupoles is the best choice. For HEDP, because of the very short pulse duration, the DTA could provide an acceleration rate of about 1MV/m. This note is divided into two parts: the first, a design based on existing experience; the second, an optimistic extrapolation. The first accelerates 16 parallel K + beams at a constant line charge density of 0.25(micro) C/m per beam to 10 MeV; the second uses a stripper and charge selector at around 4MeV followed by further acceleration to reach 40 MeV. Both benefit from more compact sources than the present 2MV injector source, although that beam is the basis of the first design and is a viable option. A pulsed drift-tube accelerator was the first major HIF experiment at LBNL. It was designed to produce a 2(micro)s rectangular 1 Ampere C s + beam at 2MeV. It ran comfortably at 1.6MeV for several years, then at lower voltages and currents for other experiments, and remnants of that experiment are in use in present experiments, still running 25 years later. The 1A current, completely equivalent to 1.8A K + , was chosen to be intermediate between the beamlets appropriate for a multi-beam accelerator, and a single beam of, say, 10A, at injection energies. The original driver scenarios using one large beam on each side of the reactor rapidly fell out of favor because of the very high transverse and longitudinal fields from the beam space charge, circa 1MV/cm and 250 kV/cm respectively, near the chamber and because of aberrations in focusing a large diameter beam down to a 1mm radius spot at a

  15. Remote Raman spectra of benzene obtained from 217 meters using a single 532 nm laser pulse.

    Science.gov (United States)

    Chen, Teng; Madey, John M J; Price, Frank M; Sharma, Shiv K; Lienert, Barry

    2007-06-01

    This report describes a mobile Raman lidar system that has been developed for spectral measurements of samples located remotely at ranges of hundreds of meters. The performance of this system has been quantitatively verified in a lidar calibration experiment using a hard target of standardized reflectance. A new record in detection range was achieved for remote Raman systems using 532 nm laser excitation. Specifically, Raman spectra of liquid benzene were measured with an integration time corresponding to a single 532 nm laser pulse at a distance of 217 meters. The single-shot Raman spectra at 217 meters demonstrated high signal-to-noise ratio and good resolution sufficient for the unambiguous identification of the samples of interest. The transmitter consists of a 20 Hz Nd:YAG laser emitting at 532 nm and 1064 nm and a 178 mm telescope through the use of which allows the system to produce a focused beam at the target location. The receiver consists of a large custom telescope (609 mm aperture) and a Czerny-Turner monochromator equipped with two fast photomultiplier tubes.

  16. Molybdenum Tube Characterization report

    Energy Technology Data Exchange (ETDEWEB)

    Beaux II, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-07

    Chemical vapor deposition (CVD) techniques have been utilized to produce free-standing molybdenum tubes with the end goal of nuclear fuel clad applications. In order to produce tubes with properties desirable for this application, deposition rates were lowered requiring long deposition durations on the order of 50 hours. Standard CVD methods as well as fluidized-bed CVD (FBCVD) methods were applied towards these objectives. Characterization of the tubes produced in this manner revealed material suitable for fuel clad applications, but lacking necessary uniformity across the length of the tubes. The production of freestanding Mo tubes that possess the desired properties across their entire length represents an engineering challenge that can be overcome in a next iteration of the deposition system.

  17. Categorising YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo

    2011-01-01

    This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC) of YouTube. The article investigates the construction of navigation processes on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s...... technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition...... and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within...

  18. Scalable gamma-ray camera for wide-area search based on silicon photomultipliers array

    Science.gov (United States)

    Jeong, Manhee; Van, Benjamin; Wells, Byron T.; D'Aries, Lawrence J.; Hammig, Mark D.

    2018-03-01

    Portable coded-aperture imaging systems based on scintillators and semiconductors have found use in a variety of radiological applications. For stand-off detection of weakly emitting materials, large volume detectors can facilitate the rapid localization of emitting materials. We describe a scalable coded-aperture imaging system based on 5.02 × 5.02 cm2 CsI(Tl) scintillator modules, each partitioned into 4 × 4 × 20 mm3 pixels that are optically coupled to 12 × 12 pixel silicon photo-multiplier (SiPM) arrays. The 144 pixels per module are read-out with a resistor-based charge-division circuit that reduces the readout outputs from 144 to four signals per module, from which the interaction position and total deposited energy can be extracted. All 144 CsI(Tl) pixels are readily distinguishable with an average energy resolution, at 662 keV, of 13.7% FWHM, a peak-to-valley ratio of 8.2, and a peak-to-Compton ratio of 2.9. The detector module is composed of a SiPM array coupled with a 2 cm thick scintillator and modified uniformly redundant array mask. For the image reconstruction, cross correlation and maximum likelihood expectation maximization methods are used. The system shows a field of view of 45° and an angular resolution of 4.7° FWHM.

  19. SENTIRAD—An innovative personal radiation detector based on a scintillation detector and a silicon photomultiplier

    Science.gov (United States)

    Osovizky, A.; Ginzburg, D.; Manor, A.; Seif, R.; Ghelman, M.; Cohen-Zada, I.; Ellenbogen, M.; Bronfenmakher, V.; Pushkarsky, V.; Gonen, E.; Mazor, T.; Cohen, Y.

    2011-10-01

    The alarming personal radiation detector (PRD) is a device intended for Homeland Security (HLS) applications. This portable device is designed to be worn or carried by security personnel to detect photon-emitting radioactive materials for the purpose of crime prevention. PRD is required to meet the scope of specifications defined by various HLS standards for radiation detection. It is mandatory that the device be sensitive and simultaneously small, pocket-sized, of robust mechanical design and carriable on the user's body. To serve these specialized purposes and requirements, we developed the SENTIRAD, a new radiation detector designed to meet the performance criteria established for counterterrorist applications. SENTIRAD is the first commercially available PRD based on a CsI(Tl) scintillation crystal that is optically coupled with a silicon photomultiplier (SiPM) serving as a light sensor. The rapidly developing technology of SiPM, a multipixel semiconductor photodiode that operates in Geiger mode, has been thoroughly investigated in previous studies. This paper presents the design considerations, constraints and radiological performance relating to the SENTIRAD radiation sensor.

  20. Immersion cooling of silicon photomultipliers (SiPM) for nuclear medicine imaging applications

    International Nuclear Information System (INIS)

    Raylman, R.R.; Stolin, A.V.

    2016-01-01

    Silicon photomultipliers (SiPM) are compact, high amplification light detection devices that have recently been incorporated into magnetic field-compatible positron emission tomography (PET) scanners. To take full advantage of these devices, it is preferable to cool them below room temperature. Most current methods are limited to the cooling of individual detector modules, increasing complexity and cost of scanners made-up of a large number of modules. In this work we investigated a new method of cooling, immersion of the detector modules in non-electrically conductive, cooled liquid. A small-scale prototype system was constructed to cool a relatively large area SiPM-based, scintillator detector module by immersing it in a circulating bath of mineral oil. Testing demonstrated that the system rapidly decreased and stabilized the temperature of the device. Operation of the detector illustrated the expected benefits of cooling, with no apparent degradation of performance attributable to immersion in fluid. - Highlights: • Immersion cooling is new, simple and inexpensive method to cool solid state based nuclear medicine scanner. • Method successfully tested on a scaled version of an SiPM-based PET detector module. • Can be scaled up to cool a complete PET scanner.

  1. Silicon photomultipliers as readout elements for a Compton effect polarimeter: the COMPASS project

    CERN Document Server

    Del Monte, E; Brandonisio, A; Muleri, F; Soffitta, P; Costa, E; di Persio, G; Cosimo, S Di; Massaro, E; Morbidini, A; Morelli, E; Pacciani, L; Fabiani, S; Michilli, D; Giarrusso, S; Catalano, O; Impiombato, D; Mineo, T; Sottile, G; Billotta, S

    2016-01-01

    COMpton Polarimeter with Avalanche Silicon readout (COMPASS) is a research and development project that aims to measure the polarization of X-ray photons through Compton Scattering. The measurement is obtained by using a set of small rods of fast scintillation materials with both low-Z (as active scatterer) and high-Z (as absorber), all read-out with Silicon Photomultipliers. By this method we can operate scattering and absorbing elements in coincidence, in order to reduce the background. In the laboratory we are characterising the SiPMs using different types of scintillators and we are optimising the performances in terms of energy resolution, energy threshold and photon tagging efficiency. We aim to study the design of two types of satellite-borne instruments: a focal plane polarimeter to be coupled with multilayer optics for hard X-rays and a large area and wide field of view polarimeter for transients and Gamma Ray Bursts. In this paper we describe the status of the COMPASS project, we report about the la...

  2. Characterization of scintillating plastic fibers and silicon photomultipliers for their usage in a particle telescope

    Energy Technology Data Exchange (ETDEWEB)

    Pruefer, Lea; Losekamm, Martin; Poeschl, Thomas; Greenwald, Daniel; Paul, Stephan [Technische Universitaet Muenchen, 85748 Garching (Germany)

    2016-07-01

    The Multi-purpose Active-target Particle Telescope (MAPT) is a newly developed compact charged-particle detector. It can be used for space applications, such as radiation monitoring on spacecraft or for stratospheric research balloons. Its core consists of scintillating plastic fibers coupled to silicon photomultiplier (SiPMs). The energy reconstruction of the incoming particles is based on an extended Bragg curve spectroscopy technique, requiring a good measurement of the energy deposition. Therefore, non-linearities of the measured light output -such as quenching effects of the scintillating material or saturation of the SiPMs at high light yields- have to be known quantitatively. To investigate these effects, two scaled-down prototypes were built, consisting of 128 and 16 channels. The first one was tested at a stationary proton beam at Paul Scherrer Institute. We determine Birk's coefficient describing the ionization quenching of the scintillator and calculate the characteristic photon detection efficiency of the SiPMs. We explain the results of the first prototype tests and the characterization of the SiPMs.

  3. Integrating printed microfluidics with silicon photomultipliers for miniaturised and highly sensitive ATP bioluminescence detection.

    Science.gov (United States)

    Santangelo, M F; Libertino, S; Turner, A P F; Filippini, D; Mak, W C

    2018-01-15

    Bioluminescence has been widely used for important biosensing applications such as the measurement of adenosine triphosphate (ATP), the energy unit in biological systems and an indicator of vital processes. The current technology for detection is mainly based on large equipment such as readers and imaging systems, which require intensive and time-consuming procedures. A miniaturised bioluminescence sensing system, which would allow sensitive and continuous monitoring of ATP, with an integrated and low-cost disposable microfluidic chamber for handling of biological samples, is highly desirable. Here, we report the design, fabrication and testing of 3D printed microfluidics chips coupled with silicon photomultipliers (SiPMs) for high sensitive real-time ATP detection. The 3D microfluidic chip reduces reactant consumption and facilitates solution delivery close to the SiPM to increase the detection efficiency. Our system detects ATP with a limit of detection (LoD) of 8nM and an analytical dynamic range between 15nM and 1µM, showing a stability error of 3%, and a reproducibility error below of 20%. We demonstrate the dynamic monitoring of ATP in a continuous-flow system exhibiting a fast response time, ~4s, and a full recovery to the baseline level within 17s. Moreover, the SiPM-based bioluminescence sensing system shows a similar analytical dynamic range for ATP detection to that of a full-size PerkinElmer laboratory luminescence reader. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. A Compact Cosmic Ray Telescope using Silicon Photomultipliers for use in High Schools

    Science.gov (United States)

    Castro, Luis; Elizondo, Leonardo; Shelor, Mark; Cervantes, Omar; Fan, Sewan; Ritt, Stefan

    2016-03-01

    Over the years, the QuarkNet and the LBL Cosmic Ray Project have helped trained thousands of high school students and teachers to explore cosmic ray physics. To get high school students in the Salinas, CA area also excited about cosmic rays, we constructed a cosmic ray telescope as a physics outreach apparatus. Our apparatus includes a pair of plastic scintillators coupled to silicon photomultipliers (SiPM) and a coincidence circuit board. We designed and constructed custom circuit boards for mounting the SiPM detectors, the high voltage power supplies and coincidence AND circuit. The AND logic signals can be used for triggering data acquisition devices including an oscilloscope, a waveform digitizer or an Arduino microcontroller. To properly route the circuit wire traces, the circuit boards were layout in Eagle and fabricated in-house using a circuit board maker from LPKF LASER, model Protomat E33. We used a Raspberry Pi computer to control a fast waveform sampler, the DRS4 to digitize the SiPM signal waveforms. The CERN PAW software package was used to analyze the amplitude and time distributions of SiPM detector signals. At this conference, we present our SiPM experimental setup, circuit board fabrication procedures and the data analysis work flow. AIP Megger's Award, Dept. of Ed. Title V Grant PO31S090007.

  5. Reaching 200-ps timing resolution in a time-of-flight and depth-of-interaction positron emission tomography detector using phosphor-coated crystals and high-density silicon photomultipliers

    Science.gov (United States)

    Kwon, Sun Il; Ferri, Alessandro; Gola, Alberto; Berg, Eric; Piemonte, Claudio; Cherry, Simon R.; Roncali, Emilie

    2016-01-01

    Abstract. Current research in the field of positron emission tomography (PET) focuses on improving the sensitivity of the scanner with thicker detectors, extended axial field-of-view, and time-of-flight (TOF) capability. These create the need for depth-of-interaction (DOI) encoding to correct parallax errors. We have proposed a method to encode DOI using phosphor-coated crystals. Our initial work using photomultiplier tubes (PMTs) demonstrated the possibilities of the proposed method, however, a major limitation of PMTs for this application is poor quantum efficiency in yellow light, corresponding to the wavelengths of the converted light by the phosphor coating. In contrast, the red-green-blue-high-density (RGB-HD) silicon photomultipliers (SiPMs) have a high photon detection efficiency across the visible spectrum. Excellent coincidence resolving time (CRT; <210  ps) was obtained by coupling RGB-HD SiPMs and  3 × 3 × 20  mm3 lutetium fine silicate crystals coated on a third of one of their lateral sides. Events were classified in three DOI bins (∼6.7-mm width) with an average sensitivity of 83.1%. A CRT of ∼200  ps combined with robust DOI encoding is a marked improvement in the phosphor-coated approach that we pioneered. For the first time, we read out these crystals with SiPMs and clearly demonstrated the potential of the RGB-HD SiPMs for this TOF-DOI PET detector. PMID:27921069

  6. Manipulation and functionalization of nano-tubes: application to boron nitride nano-tubes

    International Nuclear Information System (INIS)

    Maguer, A.

    2007-01-01

    This PhD work is divided into two parts dealing with boron nitride (BNNT) and carbon nano-tubes. The first part is about synthesis, purification and chemical functionalization of BNNT. Single-walled BNNT are synthesized by LASER ablation of a hBN target. Improving the synthesis parameters first allowed us to limit the byproducts (hBN, boric acid). A specific purification process was then developed in order to enrich the samples in nano-tubes. Purified samples were then used to develop two new chemical functionalization methods. They both involve chemical molecules that present a high affinity towards the BN network. The use of long chain-substituted quinuclidines and borazines actually allowed the solubilization of BNNT in organic media. Purification and functionalization were developed for single-walled BNNT and were successfully applied to multi-walled BNNT. Sensibility of boron to thermic neutrons finally gave birth to a study about covalent functionalization possibilities of the network. The second part of the PhD work deals with separation of carbon nano-tubes depending on their properties. Microwave irradiation of carbon nano-tubes first allowed the enrichment of initially polydisperse samples in large diameter nano-tubes. A second strategy involving selective interaction between one type of tubes and fullerene micelles was finally envisaged to selectively solubilize carbon nano-tubes with specific electronic properties. (author) [fr

  7. Isolated Fallopian Tube Torsion

    Directory of Open Access Journals (Sweden)

    S. Kardakis

    2013-01-01

    Full Text Available Isolated torsion of the Fallopian tube is a rare gynecological cause of acute lower abdominal pain, and diagnosis is difficult. There are no pathognomonic symptoms; clinical, imaging, or laboratory findings. A preoperative ultrasound showing tubular adnexal masses of heterogeneous echogenicity with cystic component is often present. Diagnosis can rarely be made before operation, and laparoscopy is necessary to establish the diagnosis. Unfortunately, surgery often is performed too late for tube conservation. Isolated Fallopian tube torsion should be suspected in case of acute pelvic pain, and prompt intervention is necessary.

  8. Automation in tube finishing bay

    International Nuclear Information System (INIS)

    Bhatnagar, Prateek; Satyadev, B.; Raghuraman, S.; Syama Sundara Rao, B.

    1997-01-01

    Automation concept in tube finishing bay, introduced after the final pass annealing of PHWR tubes resulted in integration of number of sub-systems in synchronisation with each other to produce final cut fuel tubes of specified length, tube finish etc. The tube finishing bay which was physically segregated into four distinct areas: 1. tube spreader and stacking area, 2. I.D. sand blasting area, 3. end conditioning, wad blowing, end capping and O.D. wet grinding area, 4. tube inspection, tube cutting and stacking area has been studied

  9. Ultrasonography for confirmation of gastric tube placement.

    Science.gov (United States)

    Tsujimoto, Hiraku; Tsujimoto, Yasushi; Nakata, Yukihiko; Akazawa, Mai; Kataoka, Yuki

    2017-04-17

    %) studies to have low risk of bias in the participant selection domain because they performed ultrasound after they confirmed correct position by other methods.Few data (43 participants) were available for misplacement detection (specificity) due to the low incidence of misplacement. We did not perform a meta-analysis because of considerable heterogeneity of the index test such as the difference of echo window, the combination of ultrasound with other confirmation methods (e.g. saline flush visualization by ultrasound) and ultrasound during the insertion of the tube. For all settings, sensitivity estimates for individual studies ranged from 0.50 to 1.00 and specificity estimates from 0.17 to 1.00. For settings where X-ray was not readily available and participants underwent gastric tube insertion for drainage (four studies, 305 participants), sensitivity estimates of ultrasound in combination with other confirmatory tests ranged from 0.86 to 0.98 and specificity estimates of 1.00 with wide confidence intervals.For the studies using ultrasound alone (four studies, 314 participants), sensitivity estimates ranged from 0.91 to 0.98 and specificity estimates from 0.67 to 1.00. Of 10 studies that assessed the diagnostic accuracy of gastric tube placement, few studies had a low risk of bias. Based on limited evidence, ultrasound does not have sufficient accuracy as a single test to confirm gastric tube placement. However, in settings where X-ray is not readily available, ultrasound may be useful to detect misplaced gastric tubes. Larger studies are needed to determine the possibility of adverse events when ultrasound is used to confirm tube placement.

  10. X-ray tube

    International Nuclear Information System (INIS)

    Webley, R.S.

    1975-01-01

    The object of the invention described is to provide an X-ray tube providing a scanned X-ray output which does not require a scanned electron beam. This is obtained by an X-ray tube including an anode which is rotatable about an axis, and a source of a beam of energy, for example an electron beam, arranged to impinge on a surface of the anode to generate X-radiation substantially at the region of incidence on the anode surface. The anode is rotatable about the axis to move the region of incidence over the surface. The anode is so shaped that the rotation causes the region of incidence to move in a predetermined manner relative to fixed parts of the tube so that the generated X-radiation is scanned in a predetermined manner relative to the tube. (UK)

  11. Tube Alinement for Machining

    Science.gov (United States)

    Garcia, J.

    1984-01-01

    Tool with stepped shoulders alines tubes for machining in preparation for welding. Alinement with machine tool axis accurate to within 5 mils (0.13mm) and completed much faster than visual setup by machinist.

  12. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1982-04-01

    The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1980. Tube defects occurred at 38% of the 97 reactors surveyed. This is a marginal improvement over 1979 when defects occurred at 41% of the reactors. The number of failed tubes was also lower, 0.14% of the tubes in service in 1980 compared with 0.20% of those in service in 1979. Analysis of the causes of these failures indicates that stress corrosion cracking was the leading failure mechanism. Reactors that used all-volatile treatment of secondary water, with or without full-flow condensate demineralization since start-up showed the lowest incidence of corrosion-related defects

  13. Ear tube insertion

    Science.gov (United States)

    ... mastoiditis) or the brain, or that damages nearby nerves Injury to the ear after sudden changes in ... does not heal after the tube falls out. Most of the time, these problems DO NOT last long. They also ...

  14. Tube Feeding Troubleshooting Guide

    Science.gov (United States)

    ... the diameter is measured in units known as French sizes, or “Fr”; a low profile tube also ... your quality of life. You are encouraged to speak with your physician, dietitian, home care company, or ...

  15. Magnesium tube hydroforming

    Energy Technology Data Exchange (ETDEWEB)

    Liewald, M.; Pop, R. [Institute for Metal Forming Technology (IFU), Stuttgart (Germany)

    2008-04-15

    Magnesium alloys reveal a good strength-to-weight ratio in the family of lightweight metals and gains potential to provide up to 30% mass savings compared to aluminium and up to 75 % compared to steel. The use of sheet magnesium alloys for auto body applications is however limited due to the relatively low formability at room temperature. Within the scope of this paper, extruded magnesium tubes, which are suitable for hydroforming applications, have been investigated. Results obtained at room temperature using magnesium AZ31 tubes show that circumferential strains are limited to a maximal value of 4%. In order to examine the influence of the forming temperature on tube formability, investigations have been carried out with a new die set for hot internal high pressure (IHP) forming at temperatures up to 400 C. Earlier investigations with magnesium AZ31 tubes have shown that fractures occur along the welding line at tubes extruded over a spider die, whereby a non-uniform expansion at bursting with an elongation value of 24% can be observed. A maximum circumferential strain of approx. 60% could be attained when seamless, mechanically pre-expanded and annealed tubes of the same alloy have been used. The effect of annealing time on materials forming properties shows a fine grained structure for sufficient annealing times as well as deterioration with a large increase at same time. Hence, seamless ZM21 tubes have been used in the current investigations. With these tubes, an increased tensile fracture strain of 116% at 350 C is observed as against 19% at 20 C, obtained by tensile testing of milled specimens from the extruded tubes. This behaviour is also seen under the condition of tool contact during the IHP forming process. To determine the maximum circumferential strain at different forming temperatures and strain rates, the tubes are initially bulged in a die with square cross-section under plane stress conditions. Thereafter, the tubes are calibrated by using an

  16. Power vacuum tubes handbook

    CERN Document Server

    Whitaker, Jerry

    2012-01-01

    Providing examples of applications, Power Vacuum Tubes Handbook, Third Edition examines the underlying technology of each type of power vacuum tube device in common use today. The author presents basic principles, reports on new development efforts, and discusses implementation and maintenance considerations. Supporting mathematical equations and extensive technical illustrations and schematic diagrams help readers understand the material. Translate Principles into Specific Applications This one-stop reference is a hands-on guide for engineering personnel involved in the design, specification,

  17. Dynamics of tubes in fluid with tube-baffle interaction

    International Nuclear Information System (INIS)

    Chen, S.S.; Jendrzejczyk, J.A.; Wambsganss, M.W.

    1983-09-01

    Three series of tests are performed to evaluate the effects of tube to tube-support-plate (TSP) clearance on tube dynamic characteristics and instability phenomena for tube arrays in crossflow. Test results show that, for relatively large clearances, tubes may possess TSP-inactive modes in which the tubes rattle inside some of the tube-support-plate holes, and that the natural frequencies of TSP-inactive modes are lower than those of TSP-active modes, in which the support plates provide knife-edge type support. Tube response characteristics associated with TSP-inactive modes are sensitive to tube-to-TSP clearance, TSP thickness, excitation amplitude, tube alignment, and the fluid inside the clearance. In addition, tube response is intrinsically nonlinear, with the dominance of TSP-inactive or TSP-active modes depending on the magnitudes of different system parameters. In general, such a system is difficult to model; only a full-scale test can provide all the necessary characteristics. A tube array supported by TSPs with relatively large clearances may be subjected to dynamic instability in some of the TSP-inactive modes; tube response characteristics and impact forces on TSPs for a tube row are studied in detail in this report. Tube displacements associated with the instability of a TSP-inactive mode are small; however, impacts of the tube against TSPs may result in significant damage in a relatively short time. 52 figures

  18. Low-cost, compact, cooled photomultiplier assembly for use in magnetic fields up to 1400 Gauss

    Science.gov (United States)

    Patch, R. W.; Tashjian, R. A.; Jentner, T. A.

    1975-01-01

    Use of vortex tube for cooling and concentric shielding have produced smaller and more compact unit than was previously available. Future uses of device could include installation in gas chromatographs and mass spectrometers. Additional uses would include measurements and controls in magnetohydrodynamic power generators and fusion reactors.

  19. Evaluation of a silicon photomultiplier PET insert for simultaneous PET and MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Guen Bae; Kim, Kyeong Yun; Yoon, Hyun Suk; Son, Jeong-Whan [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Lee, Min Sun [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Im, Hyung-Jun [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Lee, Jae Sung, E-mail: jaes@snu.ac.kr [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of)

    2016-01-15

    Purpose: In this study, the authors present a silicon photomultiplier (SiPM)-based positron emission tomography (PET) insert dedicated to small animal imaging with high system performance and robustness to temperature change. Methods: The insert consists of 64 LYSO-SiPM detector blocks arranged in 4 rings of 16 detector blocks to yield a ring diameter of 64 mm and axial field of view of 55 mm. Each detector block consists of a 9 × 9 array of LYSO crystals (1.2 × 1.2 × 10 mm{sup 3}) and a monolithic 4 × 4 SiPM array. The temperature of each monolithic SiPM is monitored, and the proper bias voltage is applied according to the temperature reading in real time to maintain uniform performance. The performance of this PET insert was characterized using National Electrical Manufacturers Association NU 4-2008 standards, and its feasibility was evaluated through in vivo mouse imaging studies. Results: The PET insert had a peak sensitivity of 3.4% and volumetric spatial resolutions of 1.92 (filtered back projection) and 0.53 (ordered subset expectation maximization) mm{sup 3} at center. The peak noise equivalent count rate and scatter fraction were 42.4 kcps at 15.08 MBq and 16.5%, respectively. By applying the real-time bias voltage adjustment, an energy resolution of 14.2% ± 0.3% was maintained and the count rate varied ≤1.2%, despite severe temperature changes (10–30 °C). The mouse imaging studies demonstrate that this PET insert can produce high-quality images useful for imaging studies on the small animals. Conclusions: The developed MR-compatible PET insert is designed for insertion into a narrow-bore magnetic resonance imaging scanner, and it provides excellent imaging performance for PET/MR preclinical studies.

  20. Gastrostomy feeding tube - pump - child

    Science.gov (United States)

    ... tube feeding; PEG tube care; Feeding - gastrostomy tube - pump; G-tube - pump; Gastrostomy button - pump; Bard Button - pump; MIC-KEY - pump ... Gather supplies: Feeding pump (electronic or battery powered) Feeding ... pump (includes a feeding bag, drip chamber, roller clamp, ...

  1. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... search for current job openings visit HHS USAJobs Home >> NEI YouTube Videos >> NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract ...

  2. Self-assembling segmented coiled tubing

    Science.gov (United States)

    Raymond, David W.

    2016-09-27

    Self-assembling segmented coiled tubing is a concept that allows the strength of thick-wall rigid pipe, and the flexibility of thin-wall tubing, to be realized in a single design. The primary use is for a drillstring tubular, but it has potential for other applications requiring transmission of mechanical loads (forces and torques) through an initially coiled tubular. The concept uses a spring-loaded spherical `ball-and-socket` type joint to interconnect two or more short, rigid segments of pipe. Use of an optional snap ring allows the joint to be permanently made, in a `self-assembling` manner.

  3. Effect of impurity on electronic properties of carbon nano tubes

    International Nuclear Information System (INIS)

    Jalili, S.; Jafari, M.; Habibian, J.

    2008-01-01

    We have studied the effect of impurity on electronic properties of single-walled carbon nano tubes using Density Functional Theory. Electronic band structures and density of states of (4, 4) and (7, 0) carbon nano tubes in the presence of different amount of B and N impurities were calculated. It was found that these impurities have significant effect on the conductivity of carbon nano tubes. The metallic (4, 4) nano tube remains to be metallic after doping with B and N. The electronic properties of small gap semiconducting (7, 0) tube can extensively change in the presence of impurity. Our results indicate that B-doped and N-doped (7, 0) carbon nano tubes can be p-type and n-type semiconductors, respectively

  4. Circumferential buckling instability of a growing cylindrical tube

    KAUST Repository

    Moulton, D.E.

    2011-03-01

    A cylindrical elastic tube under uniform radial external pressure will buckle circumferentially to a non-circular cross-section at a critical pressure. The buckling represents an instability of the inner or outer edge of the tube. This is a common phenomenon in biological tissues, where it is referred to as mucosal folding. Here, we investigate this buckling instability in a growing elastic tube. A change in thickness due to growth can have a dramatic impact on circumferential buckling, both in the critical pressure and the buckling pattern. We consider both single- and bi-layer tubes and multiple boundary conditions. We highlight the competition between geometric effects, i.e. the change in tube dimensions, and mechanical effects, i.e. the effect of residual stress, due to differential growth. This competition can lead to non-intuitive results, such as a tube growing to be thinner and yet buckle at a higher pressure. © 2011 Elsevier Ltd. All rights reserved.

  5. Categorising YouTube

    Directory of Open Access Journals (Sweden)

    Thomas Mosebo Simonsen

    2011-09-01

    Full Text Available This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC of YouTube. The article investigates the construction of navigationprocesses on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within the interacting relationship of new and old genres are discussed. It is argued that the utility of a conventional categorical system is primarily of analytical and theoretical interest rather than as a practical instrument.

  6. Single atom image observation by means of scanning transmission electron microscope

    International Nuclear Information System (INIS)

    Komoda, Tsutomu; Todokoro, Hideo; Nomura, Setsuo

    1977-01-01

    In a scanning transmission electron microscope, electrons emitted from the ion source are finely focused to a spot on a specimen, and scanned with the deflection coil. The electrons transmitted through the specimen are detected by the scintillate, and converted to image signals with the photomultiplier, and the image is obtained on the cathode ray tube. The Hitachi scanning transmission electron microscope employs a field emission type electron gun, thus it can focus the electron beam to 0.3 nm diameter. In the microscope, elastically scattered electrons are captured by a doughnut shaped detector, while the electrons transmitted through the specimen without colliding with atoms and the non-elastically scattered electrons which has lost a part of their energy due to the ionization or excitation of atoms are detected by the energy analyzer installed at the bottom of the microscope. Though single atom image observation requires the fixation of the atoms to be marked on a support, the problem is how to discriminate the aimed atoms from the atoms of the support. The most sensitive method is the dark-field method which uses the difference of elastically scattered electron intensity as the signal. Thorium and iodine atom images have been successfully observed as the trials to prove the feasibility of observation of heavy atoms with the scanning transmission electron microscope. (Wakatsuki, Y.)

  7. Notes on the design of experiments and beam diagnostics with synchrotron light detected by a gated photomultiplier for the Fermilab superconducting electron linac and for the Integrable Optics Test Accelerator (IOTA)

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Romanov, Aleksandr [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Ruan, Jinhao [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Santucci, James [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Thurman-Keup, Randy [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Valishev, Alexander [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2017-11-08

    We outline the design of beam experiments for the electron linac at the Fermilab Accelerator Science and Technology (FAST) facility and for the Integrable Optics Test Accelerator (IOTA), based on synchrotron light emitted by the electrons in bend dipoles, detected with gated microchannel-plate photomultipliers (MCP-PMTs). The system can be used both for beam diagnostics (e.g., beam intensity with full dynamic range, turn-by-turn beam vibrations, etc.) and for scientific experiments, such as the direct observation of the time structure of the radiation emitted by single electrons in a storage ring. The similarity between photon pulses and spectrum at the downstream end of the electron linac and in the IOTA ring allows one to test the apparatus during commissioning of the linac.

  8. Simulations of the breakdown characteristics of n-on-p backside-illumination Silicon Photomultipliers by TCAD

    Science.gov (United States)

    He, Ran; Yan, Guangqing; Liu, Jian; Cheng, Wenxuan; Liu, Rongdan; Liang, Kun; Yang, Ru; Han, Dejun

    2018-03-01

    This paper investigates, using Synopsys Sentaurus TCAD simulation, the dependence of the breakdown voltage of n-on-p backside-illumination Silicon Photomultipliers (BSI-SiPM) on the implantation dose, the implantation energy and the screening SiO2 thickness for implantation in p-enrichment region. The simulation results indicate that the breakdown voltage decreases linearly with the implantation dose and a high implantation energy can minimize the impact of the screening SiO2 thickness on the breakdown voltage. Additionally, some key process parameters implemented in coming fabrication have been obtained.

  9. Tests of the new STIC scintillator ring prototype, the photomultipliers and optic fibers cables of the 40 deg C counters

    International Nuclear Information System (INIS)

    Silva, Tatiana da

    1997-01-01

    This paper reports the tests performed on the semicircular prototype of the new scintillator ring with readings obtained by WLS optic fibers. The prototype intends to verify the light collecting and investigate a method for fiber gluing in a circular surface, without the appearing of air bubbles which may restrain the light transmission. Also the optic fiber cables and the photomultipliers used in the 40 deg C counters have been tested in order to verify the electromagnetic energy which may leak from failures in the barrel, aiming the hermeticity enhancement, and also the existence of any damaged cable

  10. Silicon photomultipliers: On ground characterizations and modelling for use in front-end electronics aimed to space-borne experiments

    Energy Technology Data Exchange (ETDEWEB)

    Badoni, Davide [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy)]. E-mail: davide.badoni@roma2.infn.it; Altamura, Francesco [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Basili, Alessandro [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Bencardino, Raffaele [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Bidoli, Vittorio [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Casolino, Marco [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); De Carli, Anna [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Froysland, Tom [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Marchetti, Marcello [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Messi, Roberto [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Minori, Mauro [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Picozza, Piergiorgio [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Salina, Gaetano [Phy. Dep. Univ. ' Tor Vergata' , Tor Vergata Sect. INFN (Italy); Galper, Arkady [Moscow Engineering and Physics Institute (Russian Federation); Korotkov, Mikhail [Moscow Engineering and Physics Institute (Russian Federation); Popov, Alexander [Moscow Engineering and Physics Institute (Russian Federation)

    2007-03-01

    Silicon Photomultipliers (Si-PM) consist of an array of semiconductor photodiodes joint on the common substrate and operating in limited geiger mode. A new generation of Si-PM is currently under test in INFN Rome Tor Vergata facilities: they consist of a 5625 element, 3*3mm{sup 2} array with an improved light response. These elements have been characterized. Furthermore, a functional model of the Si-PM has been developed to be used in a VLSI development of front-end electronics.

  11. Balloon flight test of a Compton telescope based on scintillators with silicon photomultiplier readouts

    Science.gov (United States)

    Bloser, P. F.; Legere, J. S.; Bancroft, C. M.; Ryan, J. M.; McConnell, M. L.

    2016-03-01

    We present the results of the first high-altitude balloon flight test of a concept for an advanced Compton telescope making use of modern scintillator materials with silicon photomultiplier (SiPM) readouts. There is a need in the fields of high-energy astronomy and solar physics for new medium-energy gamma-ray ( 0.4-10 MeV) detectors capable of making sensitive observations of both line and continuum sources over a wide dynamic range. A fast scintillator-based Compton telescope with SiPM readouts is a promising solution to this instrumentation challenge, since the fast response of the scintillators permits both the rejection of background via time-of-flight (ToF) discrimination and the ability to operate at high count rates. The Solar Compton Telescope (SolCompT) prototype presented here was designed to demonstrate stable performance of this technology under balloon-flight conditions. The SolCompT instrument was a simple two-element Compton telescope, consisting of an approximately one-inch cylindrical stilbene crystal for a scattering detector and a one-inch cubic LaBr3:Ce crystal for a calorimeter detector. Both scintillator detectors were read out by 2×2 arrays of Hamamatsu S11828-3344 MPPC devices. Custom front-end electronics provided optimum signal rise time and linearity, and custom power supplies automatically adjusted the SiPM bias voltage to compensate for temperature-induced gain variations. A tagged calibration source, consisting of 240 nCi of 60Co embedded in plastic scintillator, was placed in the field of view and provided a known source of gamma rays to measure in flight. The SolCompT balloon payload was launched on 24 August 2014 from Fort Sumner, NM, and spent 3.75 h at a float altitude of 123,000 ft. The instrument performed well throughout the flight. After correcting for small ( 10%) residual gain variations, we measured an in-flight ToF resolution of 760 ps (FWHM). Advanced scintillators with SiPM readouts continue to show great promise for

  12. Balloon flight test of a Compton telescope based on scintillators with silicon photomultiplier readouts

    International Nuclear Information System (INIS)

    Bloser, P.F.; Legere, J.S.; Bancroft, C.M.; Ryan, J.M.; McConnell, M.L.

    2016-01-01

    We present the results of the first high-altitude balloon flight test of a concept for an advanced Compton telescope making use of modern scintillator materials with silicon photomultiplier (SiPM) readouts. There is a need in the fields of high-energy astronomy and solar physics for new medium-energy gamma-ray (~0.4–10 MeV) detectors capable of making sensitive observations of both line and continuum sources over a wide dynamic range. A fast scintillator-based Compton telescope with SiPM readouts is a promising solution to this instrumentation challenge, since the fast response of the scintillators permits both the rejection of background via time-of-flight (ToF) discrimination and the ability to operate at high count rates. The Solar Compton Telescope (SolCompT) prototype presented here was designed to demonstrate stable performance of this technology under balloon-flight conditions. The SolCompT instrument was a simple two-element Compton telescope, consisting of an approximately one-inch cylindrical stilbene crystal for a scattering detector and a one-inch cubic LaBr 3 :Ce crystal for a calorimeter detector. Both scintillator detectors were read out by 2×2 arrays of Hamamatsu S11828-3344 MPPC devices. Custom front-end electronics provided optimum signal rise time and linearity, and custom power supplies automatically adjusted the SiPM bias voltage to compensate for temperature-induced gain variations. A tagged calibration source, consisting of ~240 nCi of 60 Co embedded in plastic scintillator, was placed in the field of view and provided a known source of gamma rays to measure in flight. The SolCompT balloon payload was launched on 24 August 2014 from Fort Sumner, NM, and spent ~3.75 h at a float altitude of ~123,000 ft. The instrument performed well throughout the flight. After correcting for small (~10%) residual gain variations, we measured an in-flight ToF resolution of ~760 ps (FWHM). Advanced scintillators with SiPM readouts continue to show great

  13. Balloon flight test of a Compton telescope based on scintillators with silicon photomultiplier readouts

    Energy Technology Data Exchange (ETDEWEB)

    Bloser, P.F., E-mail: Peter.Bloser@unh.edu; Legere, J.S.; Bancroft, C.M.; Ryan, J.M.; McConnell, M.L.

    2016-03-11

    We present the results of the first high-altitude balloon flight test of a concept for an advanced Compton telescope making use of modern scintillator materials with silicon photomultiplier (SiPM) readouts. There is a need in the fields of high-energy astronomy and solar physics for new medium-energy gamma-ray (~0.4–10 MeV) detectors capable of making sensitive observations of both line and continuum sources over a wide dynamic range. A fast scintillator-based Compton telescope with SiPM readouts is a promising solution to this instrumentation challenge, since the fast response of the scintillators permits both the rejection of background via time-of-flight (ToF) discrimination and the ability to operate at high count rates. The Solar Compton Telescope (SolCompT) prototype presented here was designed to demonstrate stable performance of this technology under balloon-flight conditions. The SolCompT instrument was a simple two-element Compton telescope, consisting of an approximately one-inch cylindrical stilbene crystal for a scattering detector and a one-inch cubic LaBr{sub 3}:Ce crystal for a calorimeter detector. Both scintillator detectors were read out by 2×2 arrays of Hamamatsu S11828-3344 MPPC devices. Custom front-end electronics provided optimum signal rise time and linearity, and custom power supplies automatically adjusted the SiPM bias voltage to compensate for temperature-induced gain variations. A tagged calibration source, consisting of ~240 nCi of {sup 60}Co embedded in plastic scintillator, was placed in the field of view and provided a known source of gamma rays to measure in flight. The SolCompT balloon payload was launched on 24 August 2014 from Fort Sumner, NM, and spent ~3.75 h at a float altitude of ~123,000 ft. The instrument performed well throughout the flight. After correcting for small (~10%) residual gain variations, we measured an in-flight ToF resolution of ~760 ps (FWHM). Advanced scintillators with SiPM readouts continue to show

  14. Bismuth germanate coupled to near ultraviolet silicon photomultipliers for time-of-flight PET

    Science.gov (United States)

    Kwon, Sun Il; Gola, Alberto; Ferri, Alessandro; Piemonte, Claudio; Cherry, Simon R.

    2016-09-01

    Bismuth germanate (BGO) was a very attractive scintillator in early-generation positron emission tomography (PET) scanners. However, the major disadvantages of BGO are lower light yield and longer rise and decay time compared to currently popular scintillators such as LSO and LYSO. This results in poorer coincidence timing resolution and it has generally been assumed that BGO is not a suitable scintillator for time-of-flight (TOF) PET applications. However, when a 511 keV photon interacts in a scintillator, a number of Cerenkov photons are produced promptly by energetic electrons released by photoelectric or Compton interactions. If these prompt photons can be captured, they could provide a better timing trigger for PET. Since BGO has a high refractive index (increasing the Cerenkov light yield) and excellent optical transparency down to 320 nm (Cerenkov light yield is higher at shorter wavelengths), we hypothesized that the coincidence timing resolution of BGO can be significantly improved by efficient detection of the Cerenkov photons. However, since the number of Cerenkov photons is far less than the number of scintillation photons, and they are more abundant in the UV and blue part of the spectrum, photosensors need to have high UV/blue sensitivity, fast temporal response, and very low noise in order to trigger on the faint Cerenkov signal. In this respect, NUV-HD silicon photomultipliers (SiPMs) (FBK, Trento, Italy) are an excellent fit for our approach. In this study, coincidence events were measured using BGO crystals coupled with NUV-HD SiPMs. The existence and influence of Cerenkov photons on the timing measurements were studied using different configurations to exploit the directionality of the Cerenkov emissions. Coincidence resolving time values (FWHM) of ~270 ps from 2  ×  3  ×  2 mm3 BGO crystals and ~560 ps from 3  ×  3  ×  20 mm3 BGO crystals were obtained. To our knowledge, these are the best

  15. Bismuth germanate coupled to near ultraviolet silicon photomultipliers for time-of-flight PET

    Science.gov (United States)

    Kwon, Sun Il; Gola, Alberto; Ferri, Alessandro; Piemonte, Claudio; Cherry, Simon R.

    2016-01-01

    Bismuth germanate (BGO) was a very attractive scintillator in early-generation positron emission tomography (PET) scanners. However, the major disadvantages of BGO are lower light yield and longer rise and decay time compared to currently popular scintillators such as LSO and LYSO. This results in poorer coincidence timing resolution and it has generally been assumed that BGO is not a suitable scintillator for time-of-flight (TOF) PET applications. However, when a 511-keV photon interacts in a scintillator, a number of Cerenkov photons are produced promptly by energetic electrons released by photoelectric or Compton interactions. If these prompt photons can be captured, they could provide a better timing trigger for PET. Since BGO has a high refractive index (increasing the Cerenkov light yield) and excellent optical transparency down to 320 nm (Cerenkov light yield is higher at shorter wavelengths), we hypothesized that the coincidence timing resolution of BGO can be significantly improved by efficient detection of the Cerenkov photons. However, since the number of Cerenkov photons is far less than the number of scintillation photons, and they are more abundant in the UV and blue part of the spectrum, photosensors need to have high UV/blue sensitivity, fast temporal response, and very low noise in order to trigger on the faint Cerenkov signal. In this respect, NUV-HD silicon photomultipliers (SiPMs) (FBK, Trento, Italy) are an excellent fit for our approach. In this study, coincidence events were measured using BGO crystals coupled with NUV-HD SiPMs. The existence and influence of Cerenkov photons on the timing measurements were studied using different configurations to exploit the directionality of the Cerenkov emissions. Coincidence resolving time values (FWHM) of ~270 ps from 2 × 3 × 2 mm3 BGO crystals and ~560 ps from 3 × 3 × 20 mm3 BGO crystals were obtained. To our knowledge, these are the best coincidence resolving time values reported for BGO to date

  16. Fill tube fitted spheres

    International Nuclear Information System (INIS)

    Ives, B.H.

    1981-01-01

    The high temperature diffusion technique for fuel filling of some future direct drive cryogenic ICF targets may be unacceptable. The following describes a technique of fitting a 1 mm diameter x 6 μm thick glass microsphere with an approx. 50 μm O.D. glass fill tube. The process of laser drilling a 50 μm diameter hole in the microsphere wall, technique for making the epoxy joint between the sphere and fill tube, as well as the assembly procedure are also discussed

  17. Steam generator tube vibration study

    International Nuclear Information System (INIS)

    Enderlin, W.I.

    1986-01-01

    Chemical cleaning has been proposed to remove magnetite buildup in some pressurized water reactor steam generators. The US Nuclear Regulatory Commission (NRC) has expressed concern that such cleaning would combine with the tube denting caused by magnetite formation to enlarge tube/tube support plate clearances, increasing the level of flow-induced vibrations that could lead to unacceptably high tube wear and failure rates. In support of NRC, the Pacific Northwest Laboratory investigated whether such increased clearances would exacerbate tube fretting wear. Using a full-length scale model of a steam generator tube bundle, flow tests were conducted at an instrumented location through clearances representing as-built and post-cleaned tube conditions. Test results indicated little potential for increased tube wear as a result of chemical cleaning, under normal operating conditions at tube support locations similar to that tested

  18. Construction of preheaters with horizontal tubes

    Energy Technology Data Exchange (ETDEWEB)

    Goetze

    1944-09-27

    This report involved construction of preheaters for distillation and cracking plants in the oil industry, particularly in America. The use of heat transmission by radiation was also a consideration here. The recycling of waste gases occurred, but was not the rule. A convection section was often built next to the radiation section, in which the discharge gases were used for heating the incoming product. The general arrangement of the preheaters was discussed. The first form was a rectangular box with fireproof lining with tubes arranged in a single row along the outer walls and sometimes in a double row on the ceiling. It consisted of smooth and finned tubes. From the simple form a double preheater was developed that allowed one or two common discharge flues to provide as large a heating surface as possible within a reasonable space. Other items discussed were recycling of waste gases, reasons for the choice of horizontal preheaters with radiation heating, the use of vertical tubes in the U.S.A. and elsewhere in the oil industry, details of horizontal preheater tubes, end closures, material, suspension, protection against overloading by radiation, circulation heating, burners, use of horizontal radiation preheaters in hydrogenation in the U.S.A., rebuilding I. G. preheaters, construction, tube supports, and masonry. A list of references on cracking, preheaters, heat transmission, and alloyed steels was given.

  19. Pressure loss characteristics of LSTF steam generator heat-transfer tubes. Pressure loss increase due to tube internal instruments

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro

    1994-11-01

    The steam generator of the Large-Scale Test Facility (LSTF) includes 141 heat-transfer U-tubes with different lengths. Six U-tubes among them are furnished with 15 or 17 probe-type instruments (conduction probe with a thermocouple; CPT) protuberant into the primary side of the U-tubes. Other 135 U-tubes are not instrumented. This results in different hydraulic conditions between the instrumented and non-instrumented U-tubes with the same length. A series of pressure loss characteristics tests was conducted at a test apparatus simulating both types of U-tube. The following pressure loss coefficient (K CPT ) was reduced as a function of Reynolds number (Re) from these tests under single-phase water flow conditions. K CPT =0.16 5600≤Re≤52820, K CPT =60.66xRe -0.688 2420≤Re≤5600, K CPT =2.664x10 6 Re -2.06 1371≤Re≤2420. The maximum uncertainty is 22%. By using these results, the total pressure loss coefficients of full length U-tubes were estimated. It is clarified that the total pressure loss of the shortest instrumented U-tube is equivalent to that of the middle-length non-instrumented U-tube and also that a middle-length instrumented U-tube is equivalent to the longest non-instrumented U-tube. Concludingly. it is important to take account of the CPT pressure loss mentioned above in estimation of fluid behavior at the non-instrumented U-tubes either by using the LSTF experiment data from the CPT-installed U-tubes or by using any analytical codes. (author)

  20. Misdirected minitracheostomy tube

    Directory of Open Access Journals (Sweden)

    Ajmer Singh

    2017-01-01

    Full Text Available We report a patient who after an uneventful coronary artery bypass graft surgery and left ventricular aneurysmorrhaphy developed intracerebral hemorrhage and subsequently required minitracheostomy. Chest X-ray showed misdirected minitracheostomy tube facing upward toward the laryngeal opening which was repositioned using bronchoscope.

  1. A New Resonance Tube

    Science.gov (United States)

    Bates, Alan

    2017-01-01

    The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at…

  2. Thoughts of accelerator tubes

    International Nuclear Information System (INIS)

    Larson, J.D.

    1977-01-01

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators

  3. Thoughts of accelerator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Larson, J D

    1977-01-01

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators.

  4. Eustachian Tube Dysfunction

    Science.gov (United States)

    ... When it is inflated, the balloon opens a pathway for mucus and air to flow through the tube. This can help it function properly. FDA warning The U.S. Food and Drug Administration (FDA) advises against the use of ear candles. ...

  5. Tube-dwelling invertebrates

    NARCIS (Netherlands)

    Hölker, Franz; Vanni, Michael J.; Kuiper, Jan J.; Meile, Christof; Grossart, Hans Peter; Stief, Peter; Adrian, Rita; Lorke, Andreas; Dellwig, Olaf; Brand, Andreas; Hupfer, Michael; Mooij, Wolf M.; Nützmann, Gunnar; Lewandowski, Jörg

    2015-01-01

    There is ample evidence that tube-dwelling invertebrates such as chironomids significantly alter multiple important ecosystem functions, particularly in shallow lakes. Chironomids pump large water volumes, and associated suspended and dissolved substances, through the sediment and thereby compete

  6. Chest tube insertion

    Science.gov (United States)

    ... of your chest cavity. This is called the pleural space. It is done to allow your lungs to fully expand. ... pneumothorax ) Fluid buildup in the chest (called a pleural ... in the esophagus (the tube that allows food to go from the mouth ...

  7. In-service examination of IHX tubing with eddy current NDT equipment

    International Nuclear Information System (INIS)

    Brown, R.L.

    1972-01-01

    Single and multiple frequency eddy current (ET) nondestructive testing (NDT) techniques and equipment were investigated for in-service inspection of sodium-contaminated intermediate heat exchanger (IHX) tubing. A four frequency technique, demonstrated in the laboratory, was relatively insensitive to signals caused by probe motion, tube support plates, and residual sodium on the outer surface of the tubes. No method was found to avoid the signals from residual sodium on the inside surfaces of the tube. (U.S.)

  8. Time resolution of Burle 85001 micro-channel plate photo-multipliers in comparison with Hamamatsu R2083

    Energy Technology Data Exchange (ETDEWEB)

    V. Baturin; V. Burkert; W. Kim; S. Majewsky; D. Nekrasov; K. Park; V. Popov; E. S. Smith; D. Son; S. S. Stepanyan; C. Zorn

    2005-06-01

    The CLAS detector will require improvements in its particle identification system to take advantage of the higher energies provided by the Jefferson Laboratory accelerator upgrade to 12 GeV. To this end, we have studied the timing characteristics of the micro-channel plate photo-multiplier 85001 from Burle, which can be operated in a high magnetic field environment. For reference and comparison, measurements were also made using the standard PMT R2083 from Hamamatsu using two timing methods. The cosmic ray method, which utilizes three identical scintillating counters 2cm x 3cm x 50cm with PMs at the ends, yields 59.1(0.7)ps. The location method of particles from radiative source with known coordinates has been used to compare timing resolutions of R2083 and Burle-85001. This ''coordinate method'' requires only one counter instrumented with two PMs and it yields 59.5(0.7)ps. For the micro-channel plate photomultiplier from Burle with an external amplification of 10 to the signals, the co ordinate method yields 130(4)ps. This method also makes it possible to estimate the number of primary photo-electrons.

  9. Drift tubes of Linac 2

    CERN Multimedia

    Photographic Service

    1977-01-01

    Being redied for installation, those at the right are for tank 1, those on the left for tank 2. Contrary to Linac 1, which had drift-tubes supported on stems, here the tubes are suspended, for better mechanical stability.

  10. Rubens Flame-Tube Demonstration.

    Science.gov (United States)

    Ficken, George W.; Stephenson, Francis C.

    1979-01-01

    Investigates and explains the phenomenon associated with Rubens flame-tube demonstration, specifically the persistance of flames at regular intervals along the tube for few minutes after the gas is turned off. (GA)

  11. Prospects for stronger calandria tubes

    International Nuclear Information System (INIS)

    Ells, C.E.; Coleman, C.E.; Hosbons, R.R.; Ibrahim, E.F.; Doubt, G.L.

    1990-12-01

    The CANDU calandria tubes, made of seam welded and annealed Zircaloy-2, have given exemplary service in-reactor. Although not designed as a system pressure containment, calandria tubes may remain intact even in the face of pressure tube rupture. One such incident at Pickering Unit 2 demonstrated the economic advantage of such an outcome, and a case can be made for increasing the probability that other calandria tubes would perform in a similar fashion. Various methods of obtaining stronger calandria tubes are available, and reviewed here. When the tubes are internally pressurized, the weld is the weak section of the tube. Increasing the oxygen concentration in the starting sheet, and thickening the weld, are promising routes to a stronger tube

  12. Expansion lyre-shaped tube

    International Nuclear Information System (INIS)

    Andro, Jean.

    1973-01-01

    The invention relates the expansion lyre-shaped tube portions formed in dudgeoned tubular bundles between two bottom plates. An expansion lyre comprises at least two sets of tubes of unequal lengths coplanar and symmetrical with respect to the main tube axis, with connecting portions between the tubes forming said sets. The invention applies to apparatus such as heat exchangers, heaters, superheaters or breeders [fr

  13. NEI You Tube Videos: Amblyopia

    Science.gov (United States)

    ... NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract Convergence Insufficiency Diabetic Eye Disease Dilated Eye Exam Dry Eye For Kids Glaucoma Healthy Vision Tips Leber Congenital Amaurosis Low ...

  14. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract Convergence Insufficiency Diabetic Eye Disease Dilated Eye Exam Dry Eye For Kids Glaucoma Healthy Vision Tips Leber Congenital Amaurosis Low ...

  15. Development of well logging neutron tube with diameter 22 mm

    International Nuclear Information System (INIS)

    Xiao Kunxiang; Xiang Wei; Mei Lin; Liang Chuan

    2014-01-01

    The structure design and performance of well logging neutron tube with diameter 22 mm are introduced. The ion source of neutron tube is penning ion source, the alnico is placed in the elicitation cathode which make the ion densely and concentration in elicitation hole. The single electrode is used in ion optics and the resistor is used in target electrode, which increase the stably performances of neutron tube. The discharge current is over 200 microampere when pressure is 10 -2 Pa in ion source and the neutron output is over l.5 × lO 8 neutron per second. The well logging neutron tube has good characteristics, such as small volume, enduring high temperature, high neutron yield etc. The development neutron tube can be used in well logging in oil field. (authors)

  16. Status of pulse tube development at CEA/SBT

    International Nuclear Information System (INIS)

    Ravex, A.; Rolland, P.

    1994-01-01

    Interest in the pulse tube comes from its potential for high reliability and low level of induced vibration. A numerical model has been developed to provide a tool for practical design. It has been successfully validated against the experimental results obtained with a single stage double inlet pulse tube which has achieved a temperature of 28 K at a frequency of a few Hz. Further developments have demonstrated the capability of operating a pulse tube at higher frequencies in association with a Stirling pressure oscillator. Current projects include coaxial geometry for miniature pulse tubes with linear resonant pressure oscillators. A 4 K multistaged pulse tube is also in development. (authors). 5 figs., 12 refs

  17. Neutron image intensifier tubes

    International Nuclear Information System (INIS)

    Verat, M.; Rougeot, H.; Driard, B.

    1983-01-01

    The most frequently used techniques in neutron radiography employ a neutron converter consisting of either a scintillator or a thin metal sheet. The radiation created by the neutrons exposes a photographic film that is in contact with the converter: in the direct method, the film is exposed during the time that the object is irradiated with neutrons; in the transfer method, the film is exposed after the irradiation of the object with neutrons. In industrial non-destructive testing, when many identical objects have to be checked, these techniques have several disadvantages. Non-destructive testing systems without these disadvantages can be constructed around neutron-image intensifier tubes. A description and the operating characteristics of neutron-image intensifier tubes are given. (Auth.)

  18. Neural tube defects

    Directory of Open Access Journals (Sweden)

    M.E. Marshall

    1981-09-01

    Full Text Available Neural tube defects refer to any defect in the morphogenesis of the neural tube, the most common types being spina bifida and anencephaly. Spina bifida has been recognised in skeletons found in north-eastern Morocco and estimated to have an age of almost 12 000 years. It was also known to the ancient Greek and Arabian physicians who thought that the bony defect was due to the tumour. The term spina bifida was first used by Professor Nicolai Tulp of Amsterdam in 1652. Many other terms have been used to describe this defect, but spina bifida remains the most useful general term, as it describes the separation of the vertebral elements in the midline.

  19. Simulating the fluid-structure interaction of a flexible tube in an array of rigid tubes

    International Nuclear Information System (INIS)

    Warnica, D.; Maleki, M.; Hariri, A.; Feldman, H.

    2011-01-01

    Two important single-phase mechanisms for flow-induced vibration of heat-exchanger tube bundles were used to demonstrate the capabilities of commercial software to simulate unsteady fluid-structure interactions (FSI). Reasonable agreement was obtained between the FSI simulations and experimental data for the onset of fluid elastic instability. There was also reasonable agreement between the FSI simulations and empirical correlations for the dynamic tube response to random turbulence excitation. Additional benefits of performing FSI simulations were the ability to characterize important features of the unsteady flow fields and hydrodynamic parameters such as viscous damping coefficients, which would otherwise require elaborate experimental measurements. (author)

  20. CRL X-ray tube

    International Nuclear Information System (INIS)

    Kolchevsky, N.N.; Petrov, P.V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed. (authors)

  1. CRL X-RAY TUBE

    OpenAIRE

    Kolchevsky, N. N.; Petrov, P. V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed.

  2. Tachyon tube on non BPS D-branes

    International Nuclear Information System (INIS)

    Huang Wunghong

    2004-01-01

    We report our searches for a single tubular tachyonic solution of regular profile on unstable non BPS D3-branes. We first show that some extended Dirac-Born-Infeld tachyon actions in which new contributions are added to avoid the Derrick's no-go theorem still could not have a single regular tube solution. Next we use the Minahan-Zwiebach tachyon action to find the regular tube solutions with circular or elliptic cross section. With a critical electric field, the energy of the tube comes entirely from the D0 and strings, while the energy associated to the tubular D2-brane tension is vanishing. We also show that fluctuation spectrum around the tube solution does not contain tachyonic mode. The results are consistent with the identification of the tubular configuration as a BPS D2-brane. (author)

  3. Some Observations on Carbon Nano tubes Susceptibility to Cell Phagocytosis

    International Nuclear Information System (INIS)

    Fraczek-Szczypta, A.; Menaszek, E.; Blazewicz, S.; Menaszek, E.

    2011-01-01

    The aim of this study was to assess the influence of different types of carbon nano tubes (CNTs) on cell phagocytosis. Three kinds of carbon nano tubes: single-walled carbon nano horns (SWCNHs), multi walled carbon nano tubes (MWCNTs), and ultra-long single-walled carbon nano tubes (ULSWCNTs) before and after additional chemical functionalization were seeded with macrophage cell culture. Prior to biological testing, the CNTs were subjected to dispersion process with the use of phosphate buffered solution (PBS) and PBS containing surfactant (Tween 20) or dimethyl sulfoxide (DMSO). The results indicate that the cells interaction with an individual nano tube is entirely different as compared to CNTs in the form of aggregate. The presence of the surfactant favors the CNTs dispersion in culture media and facilitates phagocytosis process, while it has disadvantageous influence on cells morphology. The cells phagocytosis is a more effective for MWCNTs and SWCNHs after their chemical functionalization. Moreover, these nano tubes were well dispersed in culture media without using DMSO or surfactant. The functionalized carbon nano tubes were easily dispersed in pure PBS and seeded with cells

  4. Damping in heat exchanger tube bundles. A review

    International Nuclear Information System (INIS)

    Iqbal, Qamar; Khushnood, Shahab; Ghalban, Ali Roheim El; Sheikh, Nadeem Ahmed; Malik, Muhammad Afzaal; Arastu, Asif

    2007-01-01

    Damping is a major concern in the design and operation of tube bundles with loosely supported tubes in baffles for process shell and tube heat exchangers and steam generators which are used in nuclear, process and power generation industries. System damping has a strong influence on the amplitude of vibration. Damping depends upon the mechanical properties of the tube material, geometry of intermediate supports and the physical properties of shell-side fluid. Type of tube motion, number of supports, tube frequency, vibration amplitude, tube mass or diameter, side loads, support thickness, higher modes, shell-side temperature etc., affect damping in tube bundles. The importance of damping is further highlighted due to current trend of larger exchangers with increased shell-side velocities in modern units. Various damping mechanisms have been identified (Friction damping, Viscous damping, Squeeze film damping, Support damping. Two-Phase damping, and very recent-Thermal damping), which affect the performance of process exchangers and steam generators with respect to flow induced vibration design, including standard design guidelines. Damping in two-phase flow is very complex and highly void fraction, and flow-regime dependent. The current paper focuses on the various known damping mechanisms subjected to both single and two-phase cross-flow in process heat exchangers and steam generators and formulates the design guidelines for safer design. (author)

  5. Device for the selective positioning of a component on a tube plate

    International Nuclear Information System (INIS)

    1974-01-01

    The invention relates to a device for the selective positioning of a component on a tube plate. It particularly applies to the positioning of a guide tube head successively opposite all the tubes of the tube bundle of a nuclear reactor steam generator. The large number of tubes in the tube bundle of the steam generator in a pressure water nuclear power station must be checked periodically for any likely corrosion. This check is effected with a Foucault current probe which is inserted in each tube in turn and is connected to a probe signal processing unit. The probe is placed in a flexible guide tube brought in turn in front of each tube of the bundle to be checked. The invention concerns a device to move the opening of a tube guide for a Foucault current detector over the entire surface of the tube plate, thereby providing access to all the tubes whilst limiting the interventions to a single positioning and a single withdrawal of the apparatus for testing all the bundle. Between the two interventions at the beginning and end of the operation, all displacements are remote controlled from outside the dangerous radioacive area [fr

  6. Stress-Assisted Corrosion in Boiler Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Preet M Singh; Steven J Pawel

    2006-05-27

    A number of industrial boilers, including in the pulp and paper industry, needed to replace their lower furnace tubes or decommission many recovery boilers due to stress-assisted corrosion (SAC) on the waterside of boiler tubes. More than half of the power and recovery boilers that have been inspected reveal SAC damage, which portends significant energy and economic impacts. The goal of this project was to clarify the mechanism of stress-assisted corrosion (SAC) of boiler tubes for the purpose of determining key parameters in its mitigation and control. To accomplish this in-situ strain measurements on boiler tubes were made. Boiler water environment was simulated in the laboratory and effects of water chemistry on SAC initiation and growth were evaluated in terms of industrial operations. Results from this project have shown that the dissolved oxygen is single most important factor in SAC initiation on carbon steel samples. Control of dissolved oxygen can be used to mitigate SAC in industrial boilers. Results have also shown that sharp corrosion fatigue and bulbous SAC cracks have similar mechanism but the morphology is different due to availability of oxygen during boiler shutdown conditions. Results are described in the final technical report.

  7. Silicon photomultiplier arrays - a novel photon detector for a high resolution tracker produced at FBK-irst, Italy

    International Nuclear Information System (INIS)

    Greim, R.; Gast, H.; Kirn, T.; Olzem, J.; Yearwood, G. Roper; Schael, S.; Zimmermann, N.; Ambrosi, G.; Azzarello, P.; Battiston, R.; Piemonte, C.

    2009-01-01

    A silicon photomultiplier (SiPM) array has been developed at FBK-irst [Piemonte C., Nucl. Instrum. Methods A, 568 (2006) 224; Piemonte C. et al., IEEE Trans. Nucl. Sci., 54 (2007) 236] having 32 channels and a dimension of 8.0x1.1mm 2 . Each 250 μm wide channel is subdivided into 5x22 rectangularly arranged pixels. These sensors are developed to read out a modular high resolution scintillating fiber tracker. Key properties like breakdown voltage, gain and photon detection efficiency (PDE) are found to be homogeneous over all 32 channels of an SiPM array. This could make scintillating fiber trackers with SiPM array readout a promising alternative to available tracker technologies, if noise properties and the PDE are improved.

  8. Silicon photomultiplier arrays - a novel photon detector for a high resolution tracker produced at FBK-irst, Italy

    Energy Technology Data Exchange (ETDEWEB)

    Greim, R.; Gast, H.; Kirn, T.; Olzem, J.; Yearwood, G. Roper; Schael, S.; Zimmermann, N. [I. Physikalisches Institut B, RWTH Aachen University, 52074 Aachen (Germany); Ambrosi, G.; Azzarello, P. [Dipartimento di Fisica, Universita di Perugia, 06123 Perugia (Italy); Battiston, R. [Dipartimento di Fisica, Universita di Perugia, 06123 Perugia (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, 06123 Perugia (Italy); Piemonte, C. [Fondazione Bruno Kessler - Istituto per la Ricerca Scientifica e tecnologica, 38050 Trento (Italy)

    2009-12-15

    A silicon photomultiplier (SiPM) array has been developed at FBK-irst [Piemonte C., Nucl. Instrum. Methods A, 568 (2006) 224; Piemonte C. et al., IEEE Trans. Nucl. Sci., 54 (2007) 236] having 32 channels and a dimension of 8.0x1.1mm{sup 2}. Each 250 mum wide channel is subdivided into 5x22 rectangularly arranged pixels. These sensors are developed to read out a modular high resolution scintillating fiber tracker. Key properties like breakdown voltage, gain and photon detection efficiency (PDE) are found to be homogeneous over all 32 channels of an SiPM array. This could make scintillating fiber trackers with SiPM array readout a promising alternative to available tracker technologies, if noise properties and the PDE are improved.

  9. Possible application of silicon photomultiplier technology to detect the presence of spirit and intention: three proof-of-concept experiments.

    Science.gov (United States)

    Schwartz, Gary E

    2010-01-01

    Research investigating the survival of consciousness hypothesis has been hampered by the lack of an independent measure of the purported presence of spirit (POS). Although numerous anecdotes involving electronic devices (including tape recorders, answering machines, and computers) claim that POS can be detected with sensitive electromagnetic sensors, little systematic laboratory research has investigated this possibility. The purpose of this exploratory laboratory research was to test the feasibility of using a state-of-the-art silicon photomultiplier system to detect low photon levels potentially associated with POS. A PCDMini photon counting device manufactured by sensL provided a sensitive measure of sums of photons over time. Three proof-of-concept experiments were conducted. Each included multiple five-minute trials of "invited spirit" conditions as well as baseline controls. One experiment included a set of 10 noninvited control trials as well as controls for experimenter intention per se. Data were collected as part of a university laboratory devoted to researching advances in consciousness and health. The participants were purported spirits presumably motivated to participate in the research. The primary intervention was the experimenter's intention for purported spirits to enter the light-tight chamber on specified trials. In a light-tight chamber, the PCDMini device software counted and displayed individual sums of typically 13 to 25 photon detections per approximately 90-milliseconds time periods (in complete darkness, most time periods contained zero photons detected); the number of photon sums could be counted precisely in five-minute periods. The average number of photon sums was found to be significantly higher in purported POS trials compared with noninvited trials. Matched control trials as well as explicit experimenter intention trials showed no effects. Silicon photomultiplier devices may be sufficiently sensitive to investigate the POS and

  10. Silicon photomultipliers in scintillation detectors used for gamma ray energies up to 6.1 MeV

    Science.gov (United States)

    Grodzicka-Kobylka, M.; Szczesniak, T.; Moszyński, M.; Swiderski, L.; Szawłowski, M.

    2017-12-01

    Majority of papers concerning scintillation detectors with light readout by means of silicon photomultipliers refer to nuclear medicine or radiation monitoring devices where energy of detected gamma rays do not exceed 2 MeV. Detection of gamma radiation with higher energies is of interest to e.g. high energy physics and plasma diagnostics. The aim of this paper is to study applicability (usefulness) of SiPM light readout in detection of gamma rays up to 6.1 MeV in combination with various scintillators. The reported measurements were made with 3 samples of one type of Hamamatsu TSV (Through-Silicon Via technology) MPPC arrays. These 4x4 channel arrays have a 50 × 50 μm2 cell size and 12 × 12 mm2 effective active area. The following scintillators were used: CeBr3, NaI:Tl, CsI:Tl. During all the tests detectors were located in a climatic chamber. The studies are focused on optimization of the MPPC performance for practical use in detection of high energy gamma rays. The optimization includes selection of the optimum operating voltage in respect to the required energy resolution, dynamic range, linearity and pulse amplitude. The presented temperature tests show breakdown voltage dependence on the temperature change and define requirements for a power supply and gain stabilization method. The energy spectra for energies between 511 keV and 6.1 MeV are also presented and compared with data acquired with a classic photomultiplier XP5212B readout. Such a comparison allowed study of nonlinearity of the tested MPPCs, correction of the energy spectra and proper analysis of the energy resolution.

  11. Free compression tube. Applications

    Science.gov (United States)

    Rusu, Ioan

    2012-11-01

    During the flight of vehicles, their propulsion energy must overcome gravity, to ensure the displacement of air masses on vehicle trajectory, to cover both energy losses from the friction between a solid surface and the air and also the kinetic energy of reflected air masses due to the impact with the flying vehicle. The flight optimization by increasing speed and reducing fuel consumption has directed research in the aerodynamics field. The flying vehicles shapes obtained through studies in the wind tunnel provide the optimization of the impact with the air masses and the airflow along the vehicle. By energy balance studies for vehicles in flight, the author Ioan Rusu directed his research in reducing the energy lost at vehicle impact with air masses. In this respect as compared to classical solutions for building flight vehicles aerodynamic surfaces which reduce the impact and friction with air masses, Ioan Rusu has invented a device which he named free compression tube for rockets, registered with the State Office for Inventions and Trademarks of Romania, OSIM, deposit f 2011 0352. Mounted in front of flight vehicles it eliminates significantly the impact and friction of air masses with the vehicle solid. The air masses come into contact with the air inside the free compression tube and the air-solid friction is eliminated and replaced by air to air friction.

  12. Shock tube Multiphase Experiments

    Science.gov (United States)

    Middlebrooks, John; Allen, Roy; Paudel, Manoj; Young, Calvin; Musick, Ben; McFarland, Jacob

    2017-11-01

    Shock driven multiphase instabilities (SDMI) are unique physical phenomena that have far-reaching practical applications in engineering and science. The instability is present in high energy explosions, scramjet combustors, and supernovae events. The SDMI arises when a multiphase interface is impulsively accelerated by the passage of a shockwave. It is similar in development to the Richtmyer-Meshkov (RM) instability however, particle-to-gas coupling is the driving mechanism of the SDMI. As particle effects such as lag and phase change become more prominent, the SDMI's development begins to significantly deviate from the RM instability. We have developed an experiment for studying the SDMI in our shock tube facility. In our experiments, a multiphase interface is created using a laminar jet and flowed into the shock tube where it is accelerated by the passage of a planar shockwave. The interface development is captured using CCD cameras synchronized with planar laser illumination. This talk will give an overview of new experiments conducted to examine the development of a shocked cylindrical multiphase interface. The effects of Atwood number, particle size, and a second acceleration (reshock) of the interface will be discussed.

  13. Bacterial Biofilms in Jones Tubes.

    Science.gov (United States)

    Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

    To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

  14. Failure analysis of boiler tube

    International Nuclear Information System (INIS)

    Mehmood, K.; Siddiqui, A.R.

    2007-01-01

    Boiler tubes are energy conversion components where heat energy is used to convert water into high pressure superheated steam, which is then delivered to a turbine for electric power generation in thermal power plants or to run plant and machineries in a process or manufacturing industry. It was reported that one of the tubes of a fire-tube boiler used in a local industry had leakage after the formation of pits at the external surface of the tube. The inner side of the fire tube was working with hot flue gasses with a pressure of 10 Kg/cm/sup 2/ and temperature 225 degree C. The outside of the tube was surrounded by feed water. The purpose of this study was to determine the cause of pits developed at the external surface of the failed boiler tube sample. In the present work boiler tube samples of steel grade ASTM AI61/ASTM A192 were analyzed using metallographic analysis, chemical analysis, and mechanical testing. It was concluded that the appearance of defects on the boiler tube sample indicates cavitation type corrosion failure. Cavitation damage superficially resembled pitting, but surface appeared considerably rougher and had many closely spaced pits. (author)

  15. YouTube and 'psychiatry'.

    Science.gov (United States)

    Gordon, Robert; Miller, John; Collins, Noel

    2015-12-01

    YouTube is a video-sharing website that is increasingly used to share and disseminate health-related information, particularly among younger people. There are reports that social media sites, such as YouTube, are being used to communicate an anti-psychiatry message but this has never been confirmed in any published analysis of YouTube clip content. This descriptive study revealed that the representation of 'psychiatry' during summer 2012 was predominantly negative. A subsequent smaller re-analysis suggests that the negative portrayal of 'psychiatry' on YouTube is a stable phenomenon. The significance of this and how it could be addressed are discussed.

  16. Learning from YouTube [Video Book

    Science.gov (United States)

    Juhasz, Alexandra

    2011-01-01

    YouTube is a mess. YouTube is for amateurs. YouTube dissolves the real. YouTube is host to inconceivable combos. YouTube is best for corporate-made community. YouTube is badly baked. These are a few of the things Media Studies professor Alexandra Juhasz (and her class) learned about YouTube when she set out to investigate what actually happens…

  17. Flow-induced decentering and tube support interaction for steam generator tubes: experiment and physical interpretation

    International Nuclear Information System (INIS)

    Gay, N.; Granger, S.

    1992-11-01

    Maintaining PWR components under reliable operating conditions requires a complex design to prevent various damaging processes including flow-induced vibration and wear mechanisms. To improve the prediction of tube/support interaction and wear in PWR components, EDF has undertaken a comprehensive program oriented to both experimental and computational studies. The present paper illustrates one aspect of this program, related to the determination of contact forces between steam generator tubes and anti-vibration bars (AVBs). The dynamic, nonlinear behavior of a U-tube excited by an air cross-flow is investigated on the CLAVECIN experiment. Interesting and rather unexpected results have been obtained, by varying clearances and flow velocities. The paper is focused on four main points: (i) the originality of the experiment with a force measurement device located in flow; (ii) the importance of a refined data processing for accurately measuring contact forces; (iii) the presentation of the unexpected phenomena revealed in the CLAVECIN experiment, i.e. a flow-induced decentering of the tube which changed the initial tube/AVB clearance, and the consequences on tube/support interaction; (iv) the influence of the actual tube/support clearance in flow on wear mechanisms. The work, presented in the second part of this paper, concentrates exclusively on the physical interpretation of the flow-induced decentering phenomenon and on the theoretical analysis of its consequences on dynamic tube/support interaction. We show that the flow-induced decentering phenomenon can be generated by an unstable quasi-static coupling between the flexible tube and the confined flow, in the vicinity of the support system. This phenomenon is not specific to the CLAVECIN tests and it can be expected every time that a movable obstacle is subjected to confined flow. Moreover, in single-sided impacting conditions, the theoretical analysis confirms the linear relation, found in the CLAVECIN tests

  18. Confirming nasogastric tube position with electromagnetic tracking versus pH or X-ray and tube radio-opacity.

    Science.gov (United States)

    Taylor, Stephen; Allan, Kaylee; McWilliam, Helen; Manara, Alex; Brown, Jules; Toher, Deirdre; Rayner, Wendy

    Recent evidence suggests official statistics greatly underestimate the occurrence of complications from misplaced nasogastric (NG) tubes, even when detected. Current methods of confirming tube position do not provide adequate protection from misplacement. In addition, some tubes are inadequately radio-opaque. We prospectively audited placement of Cortrak polyurethane tubes (PUTs) to determine: accuracy of the electromagnetic (EM) trace in confirming tube position, radio-opacity of PUTs compared with previously placed polyvinylchloride (PVC) Ryles tubes and whether 12 French PUTs can be used to aspirate gastric residual volumes (GRVs). A total of 127 PUTs were placed in 113 patients. EM traces accurately confirmed tube position compared with X-ray (100% agreement). A 'gastric' EM trace has been defined for future use by other operators. PUTs were adequately radio-opaque with good agreement between interpreters (>98%) whereas PVC Ryles tubes were insufficiently radio-opaque (57-73%), invisible in 23% of cases and with poor agreement between interpreters leaving risk of error. The alternative of using pH confirmation was not possible in 44%. In these cases subsequent X-ray incurred a 2-hour delay to feed and medicines. In addition, neither post-placement pH testing nor X-ray warn of lung placement and potential trauma, whereas the EM trace warned of lung placement prior to damage in 7% of placements. 12 French, single-port PUTs appear adequate to aspirate large GRVs. EM tracing may be considered a standalone method of confirming NG tube position. Corflo (Cortrak) PUTs are adequately radio-opaque. Use of PVC Ryles and other inadequately radio-opaque tubes should stop.

  19. Tube to tube excursive instability - sensitivities and transients

    International Nuclear Information System (INIS)

    Brown, M.; Layland, M.W.

    1980-01-01

    A simple basic analysis of excursive instability in a boiler tube shows how it depends upon operating conditions and physical properties. A detailed mathematical model of an AGR boiler is used to conduct a steady state parameter sensitivity survey. It is possible from this basis to anticipate the effects of changes in operating conditions and changes in design parameters upon tube to tube stability. Dynamic responses of tubes operating near the stability threshold are examined using a mathematical model. Simulated excursions are triggered by imparting small abrupt pressure changes on the boiler inlet pressure. The influences of the magnitude of the pressure change, waterside friction factor and gas side coupling between tubes are examined. (author)

  20. Nasogastric tube syndrome induced by an indwelling long intestinal tube.

    Science.gov (United States)

    Sano, Naoki; Yamamoto, Masayoshi; Nagai, Kentaro; Yamada, Keiichi; Ohkohchi, Nobuhiro

    2016-04-21

    The nasogastric tube (NGT) has become a frequently used device to alleviate gastrointestinal symptoms. Nasogastric tube syndrome (NTS) is an uncommon but potentially life-threatening complication of an indwelling NGT. NTS is characterized by acute upper airway obstruction due to bilateral vocal cord paralysis. We report a case of a 76-year-old man with NTS, induced by an indwelling long intestinal tube. He was admitted to our hospital for treatment of sigmoid colon cancer. He underwent sigmoidectomy to release a bowel obstruction, and had a long intestinal tube inserted to decompress the intestinal tract. He presented acute dyspnea following prolonged intestinal intubation, and bronchoscopy showed bilateral vocal cord paralysis. The NGT was removed immediately, and tracheotomy was performed. The patient was finally discharged in a fully recovered state. NTS be considered in patients complaining of acute upper airway obstruction, not only with a NGT inserted but also with a long intestinal tube.

  1. A New Resonance Tube

    Science.gov (United States)

    Bates, Alan

    2017-12-01

    The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at the point where sound is perceived to have maximum loudness, or at the point where the amplitude of the standing wave has maximum value, namely an antinode. An antinode coincides with the position of the tuning fork, beyond the end of the air column, which consequently introduces an end correction. One way to minimize this end correction is to measure the distance between consecutive antinodes.

  2. Piezoelectric Rotary Tube Motor

    Science.gov (United States)

    Fisher, Charles D.; Badescu, Mircea; Braun, David F.; Culhane, Robert

    2011-01-01

    A custom rotary SQUIGGLE(Registered TradeMark) motor has been developed that sets new benchmarks for small motor size, high position resolution, and high torque without gear reduction. Its capabilities cannot be achieved with conventional electromagnetic motors. It consists of piezoelectric plates mounted on a square flexible tube. The plates are actuated via voltage waveforms 90 out of phase at the resonant frequency of the device to create rotary motion. The motors were incorporated into a two-axis postioner that was designed for fiber-fed spectroscopy for ground-based and space-based projects. The positioner enables large-scale celestial object surveys to take place in a practical amount of time.

  3. Pressure tube reactor

    International Nuclear Information System (INIS)

    Matsumoto, Tomoyuki; Fujino, Michihira.

    1980-01-01

    Purpose: To equalize heavy water flow distribution by providing a nozzle for externally injecting heavy water from a vibration preventive plate to the upper portion to feed the heavy water in a pressure tube reactor and swallowing up heavy water in a calandria tank to supply the heavy water to the reactor core above the vibration preventive plate. Constitution: A moderator injection nozzle is mounted on the inner wall of a calandria tank. Heavy water is externally injected above the vibration preventive plate, and heavy water in the calandria tank is swallowed up to supply the heavy water to the core reactor above the vibration preventive plate. Therefore, the heavy water flow distribution can be equalized over the entire reactor core, and the distribution of neutron absorber dissolved in the heavy water is equalized. (Yoshihara, H.)

  4. Primary Fallopian Tube Carcinoma

    Directory of Open Access Journals (Sweden)

    Prasad K Shetty

    2011-01-01

    Full Text Available Primary Fallopian Tube Carcinoma (PFTC is rare and accounts for about 0.3% of all gynecologic cancers. Less than 1500 cases have been reported in the literature. It arises in postmenopausal women and typically presents with abdominal pelvic pain, vaginal bleeding and watery discharge. However, a correct diagnosis is rarely achieved preoperative, and in many cases, the diagnosis is made after incidental surgery for unrelated conditions commonly being ovarian carcinoma . Compared with ovarian carcinoma, PFTC more often presents at early stages, but it has a worse prognosis. PFTC is usually managed in the same manner as ovarian cancer. We report a case of Left PFTC that presented as Left ovarian mass, and we briefly review the literature.

  5. Advances in Valveless Piezoelectric Pump with Cone-shaped Tubes

    Science.gov (United States)

    Zhang, Jian-Hui; Wang, Ying; Huang, Jun

    2017-07-01

    This paper reviews the development of valveless piezoelectric pump with cone-shaped tube chronologically, which have widely potential application in biomedicine and micro-electro-mechanical systems because of its novel principles and deduces the research direction in the future. Firstly, the history of valveless piezoelectric pumps with cone-shaped tubes is reviewed and these pumps are classified into the following types: single pump with solid structure or plane structure, and combined pump with parallel structure or series structure. Furthermore, the function of each type of cone-shaped tubes and pump structures are analyzed, and new directions of potential expansion of valveless piezoelectric pumps with cone-shaped tubes are summarized and deduced. The historical argument, which is provided by the literatures, that for a valveless piezoelectric pump with cone-shaped tubes, cone angle determines the flow resistance and the flow resistance determines the flow direction. The argument is discussed in the reviewed pumps one by one, and proved to be convincing. Finally, it is deduced that bionics is pivotal in the development of valveless piezoelectric pump with cone-shaped tubes from the perspective of evolution of biological structure. This paper summarizes the current valveless piezoelectric pumps with cone-shaped tubes and points out the future development, which may provide guidance for the research of piezoelectric actuators.

  6. Carbon nano tubes embedded in polymer nano fibers

    International Nuclear Information System (INIS)

    Dror, Y.; Kedem, S.; Khalfin, R.L.; Paz, Y.; Cohenl, Y.; Salalha, Y.; Yarin, A.L.; Zussman, A.

    2004-01-01

    Full Text: The electro spinning process was used successfully to embed Multi-walled carbon nano tubes (MWCNTs) and single-walled carbon nano tubes (SWCNTs) in a matrix of poly(ethylene oxide) (PEO) forming composite nano fibers. Initial dispersion of SWCNTs in water was achieved by the use of an amphphilic alternating copolymer of styrene and sodium maleate. MWNT dispersion was achieved by ionic and nonionic surfactants. The distribution and conformation of the nano tubes in the nano fibers were studied by transmission electron microscopy (TEM). Oxygen plasma etching was used to expose the nano tubes within the nano fibers to facilitate direct observation. Nano tube alignment within the nano fibers was shown to depend strongly on the quality of the initial dispersions. Well-dispersed and separated nano tubes were embedded in a straight and aligned form while entangled non-separated nano tubes were incorporated as dense aggregates. X-ray diffraction demonstrated a high degree of orientation of the PEO crystals in the electro spun nano fibers with embedded SWCNTs, whereas incorporation of MVCNTs had a detrimental effect on the polymer orientation. Composite polymer nano fibers containing dispersed phases of nanometric TiO 2 particles and MWCNTs were also prepared electro spinning. In this case, the polymer matrix was poly(acrylonitrile) (PAN). The morphology and possible applications of these composite nano fibers will be discussed

  7. Studies of a Next-Generation Silicon-Photomultiplier-Based Time-of-Flight PET/CT System.

    Science.gov (United States)

    Hsu, David F C; Ilan, Ezgi; Peterson, William T; Uribe, Jorge; Lubberink, Mark; Levin, Craig S

    2017-09-01

    This article presents system performance studies for the Discovery MI PET/CT system, a new time-of-flight system based on silicon photomultipliers. System performance and clinical imaging were compared between this next-generation system and other commercially available PET/CT and PET/MR systems, as well as between different reconstruction algorithms. Methods: Spatial resolution, sensitivity, noise-equivalent counting rate, scatter fraction, counting rate accuracy, and image quality were characterized with the National Electrical Manufacturers Association NU-2 2012 standards. Energy resolution and coincidence time resolution were measured. Tests were conducted independently on two Discovery MI scanners installed at Stanford University and Uppsala University, and the results were averaged. Back-to-back patient scans were also performed between the Discovery MI, Discovery 690 PET/CT, and SIGNA PET/MR systems. Clinical images were reconstructed using both ordered-subset expectation maximization and Q.Clear (block-sequential regularized expectation maximization with point-spread function modeling) and were examined qualitatively. Results: The averaged full widths at half maximum (FWHMs) of the radial/tangential/axial spatial resolution reconstructed with filtered backprojection at 1, 10, and 20 cm from the system center were, respectively, 4.10/4.19/4.48 mm, 5.47/4.49/6.01 mm, and 7.53/4.90/6.10 mm. The averaged sensitivity was 13.7 cps/kBq at the center of the field of view. The averaged peak noise-equivalent counting rate was 193.4 kcps at 21.9 kBq/mL, with a scatter fraction of 40.6%. The averaged contrast recovery coefficients for the image-quality phantom were 53.7, 64.0, 73.1, 82.7, 86.8, and 90.7 for the 10-, 13-, 17-, 22-, 28-, and 37-mm-diameter spheres, respectively. The average photopeak energy resolution was 9.40% FWHM, and the average coincidence time resolution was 375.4 ps FWHM. Clinical image comparisons between the PET/CT systems demonstrated the high

  8. UCD-SPI: Un-Collimated Detector Single-Photon Imaging System for Small Animal and Plant Imaging

    Science.gov (United States)

    Walker, Katherine Leigh

    Medical imaging systems using single gamma-ray emitting radioisotopes implement collimators in order to form images. However, a tradeoff in sensitivity is inherent in the use of collimators, and modern preclinical single-photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma-rays (imaging, while still producing images of sufficient spatial resolution for certain applications in "thin" objects such as mice, small plants, and well plates used for in vitro experiments. This flexible geometry un-collimated detector single-photon imaging (UCD-SPI) system consists of two large (5 cm x 10 cm), thin (3 mm and 5 mm), closely spaced, pixelated scintillation detectors of either NaI(Tl), CsI(Na), or BGO. The detectors are read out by two adjacent Hamamatsu H8500 multichannel photomultiplier tubes. The detector heads enable the interchange of scintillation detectors of different materials and thicknesses to optimize performance for a wide range of gamma-ray energies and imaging subjects. The detectors are horizontally oriented for animal imaging, and for plant imaging the system is rotated on its side to orient the detectors vertically. While this un-collimated detector system is unable to approach the sub-mm spatial resolution obtained by the most advanced preclinical pinhole SPECT systems, the high sensitivity could enable significant and new use in molecular imaging applications which do not require good spatial resolution- for example, screening applications for drug development (small animals), for material transport and sequestration studies for phytoremediation (plants), or for counting radiolabeled cells in vitro (well plates).

  9. Characterization of tube support alloys

    International Nuclear Information System (INIS)

    Vaia, A.R.

    1985-01-01

    The involvement and relationship of carbon steel corrosion products in the tube denting phenomenon promoted an intensive research effort to: 1) understand, reproduce, and arrest the denting process, and 2) evaluate alternative tube support materials to provide additional corrosion resistance. The paper summarizes a corrosion testing program for the verification of type 405 stainless steel under acid or all volatile treatment conditions

  10. Flaming on YouTube

    NARCIS (Netherlands)

    Moor, Peter J.; Heuvelman, A.; Verleur, R.

    2010-01-01

    In this explorative study, flaming on YouTube was studied using surveys of YouTube users. Flaming is defined as displaying hostility by insulting, swearing or using otherwise offensive language. Three general conclusions were drawn. First, although many users said that they themselves do not flame,

  11. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia NEI Home Contact Us A-Z Site Map NEI on Social Media Information in Spanish (Información en español) Website, ...

  12. Basic study of single crystal fibers of Pr:Lu{sub 3}Al{sub 5}O{sub 12} scintillator for gamma-ray imaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Yanagida, Takayuki, E-mail: t_yanagi@tagen.tohoku.ac.jp [IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Kamada, Kei [Materials Research Laboratory, Furukawa Co., Ltd., 1-25-13 Kannondai, Tukuba Ibaragi 305-0856 (Japan); Kawaguchi, Noriaki [IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Tokuyama Corporation, Shibuya 3-chome, Shibuya-ku, Tokyo 150-8383 (Japan); Fujimoto, Yutaka [IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Fukuda, Kentaro [IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Tokuyama Corporation, Shibuya 3-chome, Shibuya-ku, Tokyo 150-8383 (Japan); Yokota, Yuui; Chani, Valery; Yoshikawa, Akira [IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

    2011-10-01

    Single-crystalline fibers were grown from 0.25, 0.70, and 1.50 mol% Pr-doped Lu{sub 3}Al{sub 5}O{sub 12} (LuAG) melts by the micro-pulling down ({mu}-PD) method with a diameter of 0.3-0.5 mm and a length of about 200 mm. They were cut to 10 mm long specimens, and their scintillation properties, including light yield and decay time profile, were examined. These results were compared with corresponding properties of the specimens (0.8x0.8x10 mm{sup 3}) cut from the bulk crystals produced by conventional Czochralski (CZ) growth. The {mu}-PD-grown fibers demonstrated relatively low light yield and had the same decay time constant when compared with those of the samples cut from the CZ-grown crystals. The fiber crystals were used to assemble scintillating arrays with dimensions of O 0.5x10 mm{sup 2}x20 pixels and O 0.3x10 mm{sup 2}x30 pixels coated by a BaSO{sub 4} reflector. After optical coupling with a position sensitive photomultiplier tube, the fiber-based arrays demonstrated acceptable imaging capability with a spatial resolution of about 0.5 mm.

  13. Basic study of single crystal fibers of Pr:Lu3Al5O12 scintillator for gamma-ray imaging applications

    International Nuclear Information System (INIS)

    Yanagida, Takayuki; Kamada, Kei; Kawaguchi, Noriaki; Fujimoto, Yutaka; Fukuda, Kentaro; Yokota, Yuui; Chani, Valery; Yoshikawa, Akira

    2011-01-01

    Single-crystalline fibers were grown from 0.25, 0.70, and 1.50 mol% Pr-doped Lu 3 Al 5 O 12 (LuAG) melts by the micro-pulling down (μ-PD) method with a diameter of 0.3-0.5 mm and a length of about 200 mm. They were cut to 10 mm long specimens, and their scintillation properties, including light yield and decay time profile, were examined. These results were compared with corresponding properties of the specimens (0.8x0.8x10 mm 3 ) cut from the bulk crystals produced by conventional Czochralski (CZ) growth. The μ-PD-grown fibers demonstrated relatively low light yield and had the same decay time constant when compared with those of the samples cut from the CZ-grown crystals. The fiber crystals were used to assemble scintillating arrays with dimensions of O 0.5x10 mm 2 x20 pixels and O 0.3x10 mm 2 x30 pixels coated by a BaSO 4 reflector. After optical coupling with a position sensitive photomultiplier tube, the fiber-based arrays demonstrated acceptable imaging capability with a spatial resolution of about 0.5 mm.

  14. 27 CFR 40.352 - Cigarette tubes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 40.352... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Manufacture of Cigarette Papers and Tubes Taxes § 40.352 Cigarette tubes. Cigarette tubes...

  15. Numerical simulation of tubes-in-tube heat exchanger in a mixed refrigerant Joule-Thomson cryocooler

    Science.gov (United States)

    Damle, R. M.; Ardhapurkar, P. M.; Atrey, M. D.

    2017-02-01

    Mixed refrigerant Joule-Thomson (MRJT) cryocoolers can produce cryogenic temperatures with high efficiency and low operating pressures. As compared to the high system pressures of around 150-200 bar with nitrogen, the operational pressures with non-azeotropic mixtures (e.g., nitrogen-hydrocarbons) come down to 10-25 bar. With mixtures, the heat transfer in the recuperative heat exchanger takes place in the two-phase region. The simultaneous boiling and condensation of the cold and hot gas streams lead to higher heat transfer coefficients as compared to single phase heat exchange. The two-phase heat transfer in the recuperative heat exchanger drastically affects the performance of a MRJT cryocooler. In this work, a previously reported numerical model for a simple tube-in-tube heat exchanger is extended to a multi tubes-in-tube heat exchanger with a transient formulation. Additionally, the J-T expansion process is also considered to simulate the cooling process of the heat exchanger from ambient temperature conditions. A tubes-in-tube heat exchanger offers more heat transfer area per unit volume resulting in a compact design. Also, the division of flow in multiple tubes reduces the pressure drop in the heat exchanger. Simulations with different mixtures of nitrogen-hydrocarbons are carried out and the numerical results are compared with the experimental data.

  16. HF electronic tubes. Technologies, grid tubes and klystrons

    International Nuclear Information System (INIS)

    Lemoine, Th.

    2009-01-01

    This article gives an overview of the basic technologies of electronic tubes: cathodes, electronic optics, vacuum and high voltage. Then the grid tubes, klystrons and inductive output tubes (IOT) are introduced. Content: 1 - context and classification; 2 - electronic tube technologies: cathodes, electronic optics, magnetic confinement (linear tubes), periodic permanent magnet (PPM) focussing, collectors, depressed collectors; 3 - vacuum technologies: vacuum quality, surface effects and interaction with electrostatic and RF fields, secondary emission, multipactor effect, thermo-electronic emission; 4 - grid tubes: operation of a triode, tetrodes, dynamic operation and classes of use, 'common grid' and 'common cathode' operation, ranges of utilisation and limitations, operation of a tetrode on unadjusted load, lifetime of a tetrode, uses of grid tubes; 5 - klystrons: operation, impact of space charge, multi-cavity klystrons, interaction efficiency, extended interaction klystrons, relation between interaction efficiency, perveance and efficiency, ranges of utilization and power limitations, multi-beam klystrons and sheet beam klystrons, operation on unadjusted load, klystron band pass and lifetime, uses; 6 - IOT: principle of operation, ranges of utilisation and limitations, interaction efficiency and depressed collector IOT, IOT lifetime and uses. (J.S.)

  17. Morphological and functional MR imaging of the pharyngotympanic tube

    International Nuclear Information System (INIS)

    Krombach, G.A.; Nolte-Ernsting, C.; Schmitz-Rode, T.; Guenther, R.W.; Di Martino, E.; Westhofen, M.; Prescher, A.

    2000-01-01

    Purpose: To develop and evaluate a protocol for the anatomic depiction and functional testing of the auditory tube with the use of MR imaging. Methods: Eleven volunteers were included into this study. For the morphological assessment, the imaging protocol included axial and coronal T 2 -weighted turbo-spin echo sequences (T R /T E =3194/100 ms) and a T 1 -weighted gradient echo sequence (T R /T E =42/4.6 ms). For the functional test a dynamic turbo-gradient echo sequence (TFE) with spectral fat suppression (T R /T E =15/6,2 ms; 4 sec) was obtained using the single slice technique before and during the Valsalva manoeuvre. Results: With multi-slice sequences, the osseous part of the auditory tube, the tubal cartilage (middle and lateral lamina), the ciliated epithelium, Ostmann's adipose body and the levator and tensor veli palatini muscles were delineated in all cases. During the Valsalva test, opening of the auditory tube was demonstrated in 20 of the 22 investigated sides using the dynamic TFE single slice sequence. Conclusions: The introduced MRI protocol allow visualization of the opening of the auditory tube and provides detailed anatomical information of the nasopharynx. Comprehensive morphological and functional evaluation of the auditory tube becomes possible within a single examination. (orig.) [de

  18. Falling film evaporation on a tube bundle with plain and enhanced tubes

    International Nuclear Information System (INIS)

    Habert, M.

    2009-04-01

    The complexities of two-phase flow and evaporation on a tube bundle present important problems in the design of heat exchangers and the understanding of the physical phenomena taking place. The development of structured surfaces to enhance boiling heat transfer and thus reduce the size of evaporators adds another level of complexity to the modeling of such heat exchangers. Horizontal falling film evaporators have the potential to be widely used in large refrigeration systems and heat pumps, in the petrochemical industry and for sea water desalination units, but there is a need to improve the understanding of falling film evaporation mechanisms to provide accurate thermal design methods. The characterization of the effect of enhanced surfaces on the boiling phenomena occurring in falling film evaporators is thus expected to increase and optimize the performance of a tube bundle. In this work, the existing LTCM falling film facility was modified and instrumented to perform falling film evaporation measurements on single tube row and a small tube bundle. Four types of tubes were tested including: a plain tube, an enhanced condensing tube (Gewa-C+LW) and two enhanced boiling tubes (Turbo-EDE2 and Gewa-B4) to extend the existing database. The current investigation includes results for two refrigerants, R134a and R236fa, at a saturation temperature of T sat = 5 °C, liquid film Reynolds numbers ranging from 0 to 3000, at heat fluxes between 20 and 60 kW/m² in pool boiling and falling film configurations. Measurements of the local heat transfer coefficient were obtained and utilized to improve the current prediction methods. Finally, the understanding of the physical phenomena governing the falling film evaporation of liquid refrigerants has been improved. Furthermore, a method for predicting the onset of dry patch formation has been developed and a local heat transfer prediction method for falling film evaporation based on a large experimental database has been proposed

  19. Water-storage-tube systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hemker, P.

    1981-12-24

    Passive solar collection/storage/distribution systems were surveyed, designed, fabricated, and mechanically and thermally tested. The types studied were clear and opaque fiberglass tubes, metal tubes with plastic liners, and thermosyphoning tubes. (MHR)

  20. Conditioning and breakdown phenomena in accelerator tubes

    International Nuclear Information System (INIS)

    Skorka, S.J.

    1979-01-01

    Important breakdown mechanisms in accelerator tubes are reviewed, and discharge phenomena in NEC tubes are deduced from the surface appearance of the electrodes and insulators of a used tube. Microphotos of these surfaces are shown

  1. Eddy current signal comparison for tube identification

    Science.gov (United States)

    Glass, S. W.; Vojvodic, R.

    2015-03-01

    Inspection of nuclear power plant steam generator tubes is required to justify continued safe plant operation. The steam generators consist of thousands of tubes with nominal diameters of 15 to 22mm, approximately 1mm wall thickness, and 20 to 30m in length. The tubes are inspected by passing an eddy current probe through the tubes from tube end to tube end. It is critical to know exactly which tube identification (row and column) is associated with each tube's data. This is controlled by a precision manipulator that provides the tube ID to the eddy current system. Historically there have been some instances where the manipulator incorrectly reported the tube ID. This can have serious consequences including lack of inspection of a tube, or if a pluggable indication is detected, the tube is likely to be mis-plugged thereby risking a primary to secondary leak.

  2. [Correlation of fine structures of distributions of amplitudes of a photomultiplier dark current fluctuations with the Earth rotations about its axis].

    Science.gov (United States)

    Fedorov, M V; Belousov, L V; Voeĭkov, V L; Zenchenko, K I; Zenchenko, T A; Konradov, A A; Shnol', S E

    2001-01-01

    The fine structures of distributions of photomultiplier dark current fluctuations measured in two laboratories 2000 km distant from other: in the international Institute of Biophysics (Neuss, Germany) and in the Moscow State University (Moscow, Russia) were compared. It is shown that similar forms of appropriate histograms are apparently more often realized at both locations at the same local time. This confirms the previous conclusion that the fine structure of distributions correlates with rotation of the Earth about its axis.

  3. Time-of-flight resolution of scintillating counters with Burle 85001 microchannel plate photomultipliers in comparison with Hamamatsu R2083

    Energy Technology Data Exchange (ETDEWEB)

    Baturin, V. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Burkert, V. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Kim, W. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of)]. E-mail: wooyoung@jlab.org; Majewsky, S. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Park, K. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Popov, V. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Smith, E.S. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Son, D. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Stepanyan, S.S. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Zorn, C. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

    2006-06-15

    Improvements in the time resolution of the CEBAF Large Acceptance Spectrometer (CLAS) below {approx}50ps will be required for experiments using the planned upgraded accelerator facility at Jefferson Lab. The improved time resolution will allow particle identification using time-of-flight techniques to be used effectively up to the proposed operating energy of 12GeV. The challenge of achieving this time resolution over a relatively large area is compounded because the photomultipliers (PM) in the CLAS 'time-zero' scintillating counters must operate in very high magnetic fields. Therefore, we have studied the resolution of 'time-zero' prototypes with microchannel plate PMs 85001-501 from Burle. For reference and comparison, measurements were also made using the standard PMs R2083 from Hamamatsu using two timing methods. The cosmic ray method, which utilizes three identical scintillating counters (Bicron BC-408, 2x3x50cm{sup 3}) with PMs at the ends, yields {sigma}{sub R2083}=59.1+/-0.7ps. The location method of particles from a radiative source with known coordinates has been used to compare timing resolutions of R2083 and 85001-501. This method yields {sigma}{sub R2083}=59.5+/-0.7ps and it also provides an estimate of the number of primary photoelectrons. For the microchannel plate PM from Burle the method yields {sigma}{sub 85001}=130+/-4ps due to lower number of primary photoelectrons.

  4. Fast-neutron and gamma-ray imaging with a capillary liquid xenon converter coupled to a gaseous photomultiplier

    Science.gov (United States)

    Israelashvili, I.; Coimbra, A. E. C.; Vartsky, D.; Arazi, L.; Shchemelinin, S.; Caspi, E. N.; Breskin, A.

    2017-09-01

    Gamma-ray and fast-neutron imaging was performed with a novel liquid xenon (LXe) scintillation detector read out by a Gaseous Photomultiplier (GPM). The 100 mm diameter detector prototype comprised a capillary-filled LXe converter/scintillator, coupled to a triple-THGEM imaging-GPM, with its first electrode coated by a CsI UV-photocathode, operated in Ne/5%CH4 at cryogenic temperatures. Radiation localization in 2D was derived from scintillation-induced photoelectron avalanches, measured on the GPM's segmented anode. The localization properties of 60Co gamma-rays and a mixed fast-neutron/gamma-ray field from an AmBe neutron source were derived from irradiation of a Pb edge absorber. Spatial resolutions of 12± 2 mm and 10± 2 mm (FWHM) were reached with 60Co and AmBe sources, respectively. The experimental results are in good agreement with GEANT4 simulations. The calculated ultimate expected resolutions for our application-relevant 4.4 and 15.1 MeV gamma-rays and 1-15 MeV neutrons are 2-4 mm and ~ 2 mm (FWHM), respectively. These results indicate the potential applicability of the new detector concept to Fast-Neutron Resonance Radiography (FNRR) and Dual-Discrete-Energy Gamma Radiography (DDEGR) of large objects.

  5. Study of sampling rate influence on neutron-gamma discrimination with stilbene coupled to a silicon photomultiplier.

    Science.gov (United States)

    Zhang, Jinglong; Moore, Michael E; Wang, Zhonghai; Rong, Zhou; Yang, Chaowen; Hayward, Jason P

    2017-10-01

    Choosing a digitizer with an appropriate sampling rate is often a trade-off between performance and economy. The influence of sampling rates on the neutron-gamma Pulse Shape Discrimination (PSD) with a solid stilbene scintillator coupled to a Silicon Photomultiplier was investigated in this work. Sampling rates from 125MSPS to 2GSPS from a 10-bit digitizer were used to collect detector pulses produced by the interactions of a Cf-252 source. Due to the decreased signal-to-noise ratio (SNR), the PSD performance degraded with reduced sampling rates. The reason of PSD performance degradation was discussed. Then, an efficient combination of filtering and digital signal processing (DSP) was then applied to suppress the timing noise and electronic background noise. The results demonstrate an improved PSD performance especially at low sampling rates, down to 125MSPS. Using filtering and DSP, the ascribed Figure of Merit (FOM) at 125keV ee (± 10keV ee ) increased from 0.95 to 1.02 at 125MSPS. At 300keV ee and above, all the FOMs are better than 2.00. Our study suggests that 250MSPS is a good enough sampling rate for neutron-gamma discrimination in this system in order to be sensitive to neutrons at and above ~ 125keV ee . Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Challenges of arbitrary waveform signal detection by Silicon Photomultipliers as readout for Cherenkov fibre based beam loss monitoring systems

    CERN Document Server

    Vinogradov, Sergey; Nebot del Busto, Eduardo; Kastriotou, Maria; Welsch, Carsten P

    2016-01-01

    Silicon Photomultipliers (SiPMs) are well recognised as very competitive photodetectors due to their exceptional photon number and time resolution, room-temperature low-voltage operation, insensitivity to magnetic fields, compactness, and robustness. Detection of weak light pulses of nanosecond time scale appears to be the best area for SiPM applications because in this case most of the SiPM drawbacks have a rather limited effect on its performance. In contrast to the more typical scintillation and Cherenkov detection applications, which demand information on the number of photons and/or the arrival time of the light pulse only, beam loss monitoring (BLM) systems utilising Cherenkov fibres with photodetector readout have to precisely reconstruct the temporal profile of the light pulse. This is a rather challenging task for any photon detector especially taking into account the high dynamic range of incident signals (100K – 1M) from a few photons to a few percents of destructive losses in a beam line and pre...

  7. mouseTube

    Science.gov (United States)

    Torquet, Nicolas; de Chaumont, Fabrice; Faure, Philippe; Bourgeron, Thomas; Ey, Elodie

    2016-01-01

    Ultrasonic vocalisation is a broadly used proxy to evaluate social communication in mouse models of neuropsychiatric disorders. The efficacy and robustness of testing these models suffer from limited knowledge of the structure and functions of these vocalisations as well as of the way to analyse the data. We created mouseTube , an open database with a web interface, to facilitate sharing and comparison of ultrasonic vocalisations data and metadata attached to a recording file. Metadata describe 1) the acquisition procedure, e.g ., hardware, software, sampling frequency, bit depth; 2) the biological protocol used to elicit ultrasonic vocalisations; 3) the characteristics of the individual emitting ultrasonic vocalisations ( e.g. , strain, sex, age). To promote open science and enable reproducibility, data are made freely available. The website provides searching functions to facilitate the retrieval of recording files of interest. It is designed to enable comparisons of ultrasonic vocalisation emission between strains, protocols or laboratories, as well as to test different analysis algorithms and to search for protocols established to elicit mouse ultrasonic vocalisations. Over the long term, users will be able to download and compare different analysis results for each data file. Such application will boost the knowledge on mouse ultrasonic communication and stimulate sharing and comparison of automatic analysis methods to refine phenotyping techniques in mouse models of neuropsychiatric disorders.

  8. X-ray tube

    International Nuclear Information System (INIS)

    Mayo, B.J.

    1980-01-01

    An x-ray tube in which the x-ray origin is scanned on a circle around the patient, comprises a ring-shaped anode, an electron beam travelling along a circular path being deflected onto the anode at the desired positions. The electron beam path may be in a plane parallel to the anode and perhaps at the same radius. It may be in the same plane as a transmission target/anode and at a greater radius. The anode should extend over at least 180 0 although it may extend to 360 0 . Electrostatic means may be provided to constrain the beam to the circular path and further electrostatic means deflect it to the anode of the beam and ensure it is focused at the point of incidence. Collimators provide a planar fan-shaped beam and the anode may be shaped to attenuate side lobes of the radiation. Electrode collects electrons not deflected. The focal regions may be adjacent or otherwise. Coils may provide periodic focusing to overcome space charge dispersion and dynamic adjustment of the focusing before deflection ensures focusing at target incidence. Focusing may be absent near the deflection region, and current in the coil section near the focal region should be zero. (author)

  9. Flux tubes at finite temperature

    Energy Technology Data Exchange (ETDEWEB)

    Cea, Paolo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Dipartimento di Fisica dell’Università di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cosmai, Leonardo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cuteri, Francesca; Papa, Alessandro [Dipartimento di Fisica, Università della Calabria & INFN-Cosenza,Ponte Bucci, cubo 31C, I-87036 Rende (Cosenza) (Italy)

    2016-06-07

    The chromoelectric field generated by a static quark-antiquark pair, with its peculiar tube-like shape, can be nicely described, at zero temperature, within the dual superconductor scenario for the QCD confining vacuum. In this work we investigate, by lattice Monte Carlo simulations of the SU(3) pure gauge theory, the fate of chromoelectric flux tubes across the deconfinement transition. We find that, if the distance between the static sources is kept fixed at about 0.76 fm ≃1.6/√σ and the temperature is increased towards and above the deconfinement temperature T{sub c}, the amplitude of the field inside the flux tube gets smaller, while the shape of the flux tube does not vary appreciably across deconfinement. This scenario with flux-tube “evaporation” above T{sub c} has no correspondence in ordinary (type-II) superconductivity, where instead the transition to the phase with normal conductivity is characterized by a divergent fattening of flux tubes as the transition temperature is approached from below. We present also some evidence about the existence of flux-tube structures in the magnetic sector of the theory in the deconfined phase.

  10. Very low power, high voltage base for a Photo Multiplier Tube for the KM3NeT deep sea neutrino telescope

    International Nuclear Information System (INIS)

    Timmer, P; Heine, E; Peek, H

    2010-01-01

    The described system is developed in the framework of a deep-sea submerged Very Large Volume neutrino Telescope where photons are detected by a large number of Photo Multiplier Tubes. These PMTs are placed in optical modules (OM). A basic Cockcroft-Walton (CW) voltage multiplier circuit design is used to generate multiple voltages to drive the dynodes of the photomultiplier tube. To achieve a long lifetime and a high reliability the dissipation in the OM must be kept to the minimum. The design is also constrained by size restrictions, load current, voltage range, and the maximum allowable ripple in the output voltage. A surface mount PMT-base PCB prototype is designed and successfully tested. The system draws less than 1.5 mA of supply current at a voltage of 3.3 V with outputs up to -1400 Vdc cathode voltage, a factor 10 less than the commercially available state of the art.

  11. Very low power, high voltage base for a Photo Multiplier Tube for the KM3NeT deep sea neutrino telescope

    CERN Document Server

    Timmer, P; Peek, H

    2010-01-01

    The described system is developed in the framework of a deep-sea submerged Very Large Volume neutrino Telescope where photons are detected by a large number of Photo Multiplier Tubes. These PMTs are placed in optical modules (OM). A basic Cockcroft-Walton (CW) voltage multiplier circuit design is used to generate multiple voltages to drive the dynodes of the photomultiplier tube. To achieve a long lifetime and a high reliability the dissipation in the OM must be kept to the minimum. The design is also constrained by size restrictions, load current, voltage range, and the maximum allowable ripple in the output voltage. A surface mount PMT-base PCB prototype is designed and successfully tested. The system draws less than 1.5 mA of supply current at a voltage of 3.3 V with outputs up to -1400 Vdc cathode voltage, a factor 10 less than the commercially available state of the art

  12. Measurement of Work Generation and Improvement in Performance of a Pulse Tube Engine

    Science.gov (United States)

    Hamaguchi, Kazuhiro; Futagi, Hiroaki; Yazaki, Taichi; Hiratsuka, Yoshikatsu

    Apart from double acting type engines, Stirling engines have either 2 pistons in 2 cylinders or 2 pistons in a single cylinder. Typically, the heater, regenerator and cooler are installed between the 2 pistons. The pulse tube engine, on the other hand, consists of a single piston in a single cylinder, a pulse tube, a heater, a regenerator, a cooler and a second cooler. For this paper, a simple prototype engine that uses air at normal atmospheric pressure as the working gas was fabricated. The oscillating velocity of the working gas in the pulse tube was measured using LDV, and the work flow emitting out of the pulse tube was observed. In addition, the effect of inserting heat storage material in the pulse tube on shaft power and indicated power was examined experimentally. A dramatic increase in the shaft power was achieved.

  13. PEG tubes: dealing with complications.

    Science.gov (United States)

    Malhi, Hardip; Thompson, Rosie

    A percutaneous endoscopic gastronomy tube can be used to deliver nutrition, hydration and medicines directly into the patient's stomach. Patients will require a tube if they are unable to swallow safely, putting them at risk of aspiration of food, drink and medicines into their lungs. It is vital that nurses are aware of the complications that may arise when caring for a patient with a PEG tube. It is equally important that nurses know how to deal with these complications or from where tc seek advice. This article provides a quick troubleshooting guide to help nurses deal with complications that can arise with PEG feeding.

  14. Rigid inflatable gastrostomy tube malposition

    Directory of Open Access Journals (Sweden)

    Timothy E. Murray, MB, MCh, MRCS, FFR

    2017-12-01

    Full Text Available Rigid inflatable gastrostomy (RIG tubes are widely used in contemporary clinical practice for a variety of indications. Insertion of RIG tubes is associated with a high technical success rate and low incidence of mortality. In this case report, a procedural pitfall associated with intraperitoneal-extragastric malposition is described. Rigorous assessment of abdominal radiographs, as well as awareness of the expected appearance of the RIG tube and gastropexy T-fasteners, allows the abdominal radiologist to detect early RIG position in the early postprocedural period. Abdominal radiography is a widely available and inexpensive technique. The high spatial resolution it provides makes it a valuable tool in determining hardware position.

  15. Expansion tube test time predictions

    Science.gov (United States)

    Gourlay, Christopher M.

    1988-01-01

    The interaction of an interface between two gases and strong expansion is investigated and the effect on flow in an expansion tube is examined. Two mechanisms for the unsteady Pitot-pressure fluctuations found in the test section of an expansion tube are proposed. The first mechanism depends on the Rayleigh-Taylor instability of the driver-test gas interface in the presence of a strong expansion. The second mechanism depends on the reflection of the strong expansion from the interface. Predictions compare favorably with experimental results. The theory is expected to be independent of the absolute values of the initial expansion tube filling pressures.

  16. A Study on the Development of Nonglass Solar Vacuum Tube Collector

    International Nuclear Information System (INIS)

    Oh, Seung Jin

    2008-02-01

    Nature has been providing us energy from the beginning of the world. However human has hardly used it wisely. Solar energy is a kind of renewable energy from the nature. This study has been carried out to study the use of solar energy as it is harnessed in the form of thermal energy. Solar energy is one of the most promising energy resources such as hydrogen, biomass, wind and geothermal energy, because it is clean and inexhaustible. Space heating in buildings can be provided from solar energy by systems that are similar in many respects to water heater systems. By tapping into solar energy, we can not only solve the problem of energy shortage, but also can protect the environment and benefit the human beings. There are currently two types of evacuated tube; a single glass tube and a double glass tube. The former consists of a single glass tube which contains a flat or curved aluminium plate attached to a copper heat pipe or water flow pipe. The latter consists of rows of parallel transparent glass tubes, each of which contains an absorber tube. Evacuated tube collectors introduced above, however, pose some problems as they break rather easily under mechanical stresses. This paper introduces some preliminary results in design and fabrication of a non-glass solar vacuum tube collector in which the thermosyphon(heat pipe)made of copper is used as a heat transfer device. A series of tests have been performed to assess the ability of a non-glass solar vacuum tube collector. The series of experiments are as follows: 1)Vacuum level inside a vacuum tube. 2)Effects of the air remaining inside a vacuum tube on the temperature on the absorber plate. 3)Comparison of a non-glass vacuum solar collector with a single glass evacuated tube(SEIDO 5). Different vacuum levels inside non-glass vacuum tubes were applied to check any leakage or unexpected physical or chemical developments with time. The vacuum level changed from 10 -2 torr to 5torr in 5 days due to air infiltration from

  17. Flow and oscillations in collapsible tubes: Physiological applications ...

    Indian Academy of Sciences (India)

    pressure changes associated with fluid flow in the tube may be enough to generate large area changes. Collapsible ... As a very simple model, consider a single, uniform pipe containing viscous fluid flowing steadily at volume ..... (1986). For each mode the instability occurs through a Hopf bifurcation, which is supercritical.

  18. Development and test evaluation of duplex steam reformer tube

    International Nuclear Information System (INIS)

    Allen, D.C.; Meyer, D.J.; Pflasterer, G.R.

    1980-01-01

    For HTR applications involving a steam reformer (SR), it is uncertain whether an intermediate heat exchanger (IHX) is required. There are several system configurations that could be developed for the application of nuclear heat using the steam reformer reaction. The considerations (advantages vs. disadvantages) for each of the system configurations are summarized. The approach that technically and economically appears to be the most attractive, in studies conducted by General Electric, combines the SR process heat exchanger and the IHX in a single component using a duplex tube. A central question concerning the duplex tube concept is whether the design would provide adequate leak monitoring capability and significant reduction in tritium and hydrogen diffusion, while introducing only a small increase in overall temperature difference from the helium to the process gas. A cooperative GE-KFA effort was undertaken to develop, fabricate, test, and evaluate a duplex steam reformer tube. GE was responsible for the development and fabrication of the tube, and KFA was responsible for testing the tube in the EVA I facility at Juelich. Both GE and KFA are evaluating the thermochemical and metallurgical test data. Actual fabrication of the tube was performed by Foster-Wheeler in accordance with the GE design. This paper reviews the highlights of the fabrication development and preliminary evaluation of the test data

  19. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... and Aging Program African American Program Training and Jobs Fellowships NEI Summer Intern Program Diversity In Vision ... DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home >> NEI YouTube Videos >> ...

  20. Tube-wave seismic imaging

    Science.gov (United States)

    Korneev, Valeri A [LaFayette, CA

    2009-05-05

    The detailed analysis of cross well seismic data for a gas reservoir in Texas revealed two newly detected seismic wave effects, recorded approximately 2000 feet above the reservoir. A tube-wave (150) is initiated in a source well (110) by a source (111), travels in the source well (110), is coupled to a geological feature (140), propagates (151) through the geological feature (140), is coupled back to a tube-wave (152) at a receiver well (120), and is and received by receiver(s) (121) in either the same (110) or a different receiving well (120). The tube-wave has been shown to be extremely sensitive to changes in reservoir characteristics. Tube-waves appear to couple most effectively to reservoirs where the well casing is perforated, allowing direct fluid contact from the interior of a well case to the reservoir.