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Sample records for filled wire chambers

  1. The aging of wire chambers filled with dimethyl ether: Wire and construction materials and freon impurities

    Energy Technology Data Exchange (ETDEWEB)

    Jibaly, M.; Majewski, S.; Chrusch, P. Jr.; Wojcik, R. (Florida Univ., Gainesville (USA). Dept. of Physics (USA)); Sauli, F.; Gaudaen, J. (European Organization for Nuclear Research, Geneva (Switzerland). EP-Div. (Switzerland))

    1989-11-10

    This is a complete summary of our study of the aging of different types of wire chambers, with a variety of construction materials and wires, filled with dimethyl ether (DME) of varying degrees of purity. The resistive Nicotin and Stablohm wires were corroded by DME, producing fast aging. The moderately resistive stainless steel wires were able to withstand extended irradiation (up to 1 C/cm) in high-purity DME without any apparent damage; and gold-plated tungsten and molybdenum wires exhibited a comparable behavior. Many construction materials were tested and recommendations are thus reached as to what kinds of materials are safe in building DME-operated wire chambers. Among many different Freon and hydrocarbon impurities detected in DME by means of gas chromatography (GC), Freon-11 was found to be mostly responsible for the aging, even with noncorrosive stainless steel or gold-plated wires. The availability and feasibility of obtaining Freon-free DME is reported as well. (orig.).

  2. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  3. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  4. wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  5. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  6. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  7. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  8. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  9. Wire Chamber

    CERN Multimedia

    1986-01-01

    Two wire chambers made originally for the R807 Experiment at CERN's Intersecting Storage Rings. In 1986 they were used for the PS 201 experiment (Obelix Experiment) at LEAR, the Low Energy Antiproton Ring. The group of researchers from Turin, using the chambers at that time, changed the acquisition system using for the first time 8 bit (10 bit non linear) analog to digital conversion for incoming signals from the chambers. The acquisition system was controlled by 54 CPU and 80 digital signal processors. The power required for all the electronics was 40 kW. For the period, this system was one of the most powerful on-line apparatus in the world. The Obelix Experiment was closed in 1996. To find more about how a wire chamber works, see the description for object CERN-OBJ-DE-038.

  10. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  11. Charpak hemispherical wire chamber

    CERN Multimedia

    1970-01-01

    pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  12. Plasma chemistry in wire chambers

    Energy Technology Data Exchange (ETDEWEB)

    Wise, J.

    1990-05-01

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an {sup 55}Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed.

  13. An aging study of wire chambers with dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Jibaly, M.; Chrusch, P. Jr.; Hilgenberg, G.; Majewski, S.; Wojcik, R.; Sauli, F.; Gaudaen, J.

    1989-02-01

    The authors report results on the aging of different types of resistive and non-resistive wires in wire chambers filled with dimethyl ether (DME) of varying degrees of purity. Among the Freon impurities detected in our DME batches, only Freon-11 was found to contribute to the aging process. Of the resistive wires, Nicotin and Stablohm produced fast aging, whereas stainless steel withstood extended irradiation in purified DME (up to 1 C/cm) without any apparent damage. Gold-plated tungsten and molybdenum wires produced results comparable to those of the stainless steel.

  14. Wire chamber degradation at the Argonne ZGS

    Energy Technology Data Exchange (ETDEWEB)

    Haberichter, W.; Spinka, H.

    1986-01-01

    Experience with multiwire proportional chambers at high rates at the Argonne Zero Gradient Synchrotron is described. A buildup of silicon on the sense wires was observed where the beam passed through the chamber. Analysis of the chamber gas indicated that the density of silicon was probably less than 10 ppM.

  15. Tracking with wire chambers at high luminosities

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, G.G. (Indiana Univ., Bloomington, IN (USA) Stanford Linear Accelerator Center, Menlo Park, CA (USA))

    1989-12-01

    Radiation damage and rate limitations impose severe constraints on wire chambers at the SSC. Possible conceptual designs for wire chamber tracking systems that satisfy these constraints are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 11 refs., 10 figs.

  16. Chemistry of radiation damage to wire chambers

    Energy Technology Data Exchange (ETDEWEB)

    Wise, J.

    1992-08-01

    Proportional counters are used to study aspects of radiation damage to wire chambers (wire aging). Principles of low-pressure, rf plasma chemistry are used to predict the plasma chemistry in electron avalanches (1 atm, dc). (1) Aging is studied in CF{sub 4}/iC{sub 4}H{sub 10} gas mixtures. Wire deposits are analyzed by Auger electron spectroscopy. An apparent cathode aging process resulting in loss of gain rather than in a self-sustained current is observed in CF{sub 4}-rich gases. A four-part model considering plasma polymerization of the hydrocarbon, etching of wire deposits by CF{sub 4}, acceleration of deposition processes in strongly etching environments, and reactivity of the wire surface is developed to understand anode wire aging in CF{sub 4}/iC{sub 4}H{sub 10} gases. Practical guidelines suggested by the model are discussed. (2) Data are presented to suggest that trace amounts of Freons do not affect aging rates in either dimethyl ether or Ar/C{sub 2}H{sub 6}. Apparent loss of gain is explained by attachment of primary electrons to a continuously increasing concentration of Freon 11 (CCl{sub 3}F) in the counter gas. An increase in the concentration of Freon 11 in dimethyl ether is caused by a distillation process in the gas supply bottle and is a natural consequence of the unequal volatilities of the two compounds.

  17. Wire chambers with their magnetostrictive readout

    CERN Multimedia

    1974-01-01

    This set of wire chamber planes shaped as a cylinder sector was installed inside the magnet of a polarized spin target modified to allow as well momentum analysis of the produced particles. The experiment (S126) was set up by the CERN-Trieste Collaboration in the PS beam m9 to measure spin effects in the associated production of of a positive kaon and a positive Sigma by interaction of a positive pion with polarized protons.

  18. Large aluminium wire spark chambers with magnetostrictive read-out

    CERN Document Server

    Bradamante, Franco; Daum, C; Dechelette, Paul; Fidecaro, Giuseppe; Fidecaro, Maria; Giorgi, M; Penzo, Aldo L; Piemontese, L; Renevey, Max; Schiavon, Paolo; Vascotto, Alessandro

    1974-01-01

    A set of 1 cm gap wire spark chambers with a sensitive surface of 300 * 100 cm/sup 2/ was constructed for an experiment at the CERN proton synchrotron. The Coulomb scattering was limited by using aluminium wires and by adopting a crossed-wire configuration, which allowed us to minimize the number of chambers for a given number of pairs of coordinates. The wire planes were pulsed by feeding the high voltage from strip-lines along the whole boundary of the chambers. (7 refs).

  19. Design, simulation and construction of a Wire Chamber electronics

    Science.gov (United States)

    Istemihan, Zehra

    2017-02-01

    Tracking charged particles has a wide spectrum of applications in scientific and industrial projects. The Delay Wire Chamber (DWC) is a kind of gaseous detector which is a simpler form of the Multi Wire Proportional Chamber, and was developed by the Beam Instrumentation Group at CERN. It is preferred in accelerator and particle physics experiments because of its ease of use, affordability and durability, and it also provides decent position precision. In this work, we describe the working principles of the readout electronics of a new DWC that is being designed and constructed at our laboratory. Results from the simulation of the circuit and the constructed prototype will be presented.

  20. Performance parameters of a liquid filled ionization chamber array.

    Science.gov (United States)

    Poppe, B; Stelljes, T S; Looe, H K; Chofor, N; Harder, D; Willborn, K

    2013-08-01

    In this work, the properties of the two-dimensional liquid filled ionization chamber array Octavius 1000SRS (PTW-Freiburg, Germany) for use in clinical photon-beam dosimetry are investigated. Measurements were carried out at an Elekta Synergy and Siemens Primus accelerator. For measurements of stability, linearity, and saturation effects of the 1000SRS array a Semiflex 31013 ionization chamber (PTW-Freiburg, Germany) was used as a reference. The effective point of measurement was determined by TPR measurements of the array in comparison with a Roos chamber (type 31004, PTW-Freiburg, Germany). The response of the array with varying field size and depth of measurement was evaluated using a Semiflex 31010 ionization chamber as a reference. Output factor measurements were carried out with a Semiflex 31010 ionization chamber, a diode (type 60012, PTW-Freiburg, Germany), and the detector array under investigation. The dose response function for a single detector of the array was determined by measuring 1 cm wide slit-beam dose profiles and comparing them against diode-measured profiles. Theoretical aspects of the low pass properties and of the sampling frequency of the detector array were evaluated. Dose profiles measured with the array and the diode detector were compared, and an intensity modulated radiation therapy (IMRT) field was verified using the Gamma-Index method and the visualization of line dose profiles. The array showed a short and long term stability better than 0.1% and 0.2%, respectively. Fluctuations in linearity were found to be within ±0.2% for the vendor specified dose range. Saturation effects were found to be similar to those reported in other studies for liquid-filled ionization chambers. The detector's relative response varied with field size and depth of measurement, showing a small energy dependence accounting for maximum signal deviations of ±2.6% from the reference condition for the setup used. The σ-values of the Gaussian dose response

  1. Performance parameters of a liquid filled ionization chamber array

    Energy Technology Data Exchange (ETDEWEB)

    Poppe, B.; Stelljes, T. S.; Looe, H. K.; Chofor, N. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg 26121 (Germany); Harder, D. [Prof. em., Medical Physics and Biophysics, Georg August University, Göttingen 37073 (Germany); Willborn, K. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121 (Germany)

    2013-08-15

    Purpose: In this work, the properties of the two-dimensional liquid filled ionization chamber array Octavius 1000SRS (PTW-Freiburg, Germany) for use in clinical photon-beam dosimetry are investigated.Methods: Measurements were carried out at an Elekta Synergy and Siemens Primus accelerator. For measurements of stability, linearity, and saturation effects of the 1000SRS array a Semiflex 31013 ionization chamber (PTW-Freiburg, Germany) was used as a reference. The effective point of measurement was determined by TPR measurements of the array in comparison with a Roos chamber (type 31004, PTW-Freiburg, Germany). The response of the array with varying field size and depth of measurement was evaluated using a Semiflex 31010 ionization chamber as a reference. Output factor measurements were carried out with a Semiflex 31010 ionization chamber, a diode (type 60012, PTW-Freiburg, Germany), and the detector array under investigation. The dose response function for a single detector of the array was determined by measuring 1 cm wide slit-beam dose profiles and comparing them against diode-measured profiles. Theoretical aspects of the low pass properties and of the sampling frequency of the detector array were evaluated. Dose profiles measured with the array and the diode detector were compared, and an intensity modulated radiation therapy (IMRT) field was verified using the Gamma-Index method and the visualization of line dose profiles.Results: The array showed a short and long term stability better than 0.1% and 0.2%, respectively. Fluctuations in linearity were found to be within ±0.2% for the vendor specified dose range. Saturation effects were found to be similar to those reported in other studies for liquid-filled ionization chambers. The detector's relative response varied with field size and depth of measurement, showing a small energy dependence accounting for maximum signal deviations of ±2.6% from the reference condition for the setup used. The σ-values of

  2. Development of a portable gas-filled ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Chae, K. Y.; Cha, S. M.; Gwak, M. S. [Sungkyunkwan University, Suwon (Korea, Republic of)

    2014-02-15

    A new portable gas-filled ionization chamber has been designed and constructed at the Physics Department of Sung Kyun Kwan University. To overcome the maximum count rate of ∼ 10{sup 5} particles per second of a conventional ionization chamber, which utilizes a Frisch grid, and to enhance the portability of a detector, we adopted the design of multiple electrodes and modified it from the original designs by Kimura et al. and Chae et al. The new design utilizes a stack of multiple electrodes installed perpendicular to the optical beam axis. This configuration provides a fast response time for the detector, which is essential for high-rate counting. The device has been tested with a {sup 241}Am (t{sub 1/2} = 432.2 years) radioactive α source, which mainly emits 5.486-MeV (branching ratio of 85%) and 5.443-MeV (branching ratio of 13%) α particles. An energy resolution of 6.3% was achieved.

  3. Construction and Assembly of the Wire Planes for the MicroBooNE Time Projection Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Acciarri, R. [Fermilab; Adams, C. [Yale U.; Asaadi, J. [Texas A-M; Danaher, J. [Fermilab; Fleming, B. T. [Yale U.; Gardner, R. [Fermilab; Gollapinni, S. [Kansas State U.; Grosso, R. [Cincinnati U.; Guenette, R. [Oxford U.; Littlejohn, B. R. [IIT, Chicago; Lockwitz, S. [Fermilab; Raaf, J. L. [Fermilab; Soderberg, M. [Syracuse U.; St. John, J. [Cincinnati U.; Strauss, T. [Fermilab; Szelc, A. M. [Manchester U.; Yu, B. [Brookhaven

    2017-03-09

    In this paper we describe how the readout planes for the MicroBooNE Time Projection Chamber were constructed, assembled and installed. We present the individual wire preparation using semi-automatic winding machines and the assembly of wire carrier boards. The details of the wire installation on the detector frame and the tensioning of the wires are given. A strict quality assurance plan ensured the integrity of the readout planes. The different tests performed at all stages of construction and installation provided crucial information to achieve the successful realization of the MicroBooNE wire planes.

  4. Construction and Assembly of the Wire Planes for the MicroBooNE Time Projection Chamber

    CERN Document Server

    Acciarri, R; Asaadi, J; Danaher, J; Fleming, B T; Gardner, R; Gollapinni, S; Grosso, R; Guenette, R; Littlejohn, B R; Lockwitz, S; Raaf, J L; Soderberg, M; John, J St; Strauss, T; Szelc, A M; Yu, B

    2016-01-01

    In this paper we describe how the readout planes for the MicroBooNE Time Projection Chamber were constructed, assembled and installed. We present the individual wire preparation using semi-automatic winding machines and the assembly of wire carrier boards. The details of the wire installation on the detector frame and the tensioning of the wires are given. A strict quality assurance plan ensured the integrity of the readout planes. The different tests performed at all stages of construction and installation provided crucial information to achieve the successful realisation of the MicroBooNE wire planes.

  5. Multi-wire proportional chambers with a central hole and high counting-rate capability

    NARCIS (Netherlands)

    Volkerts, M; Bakker, A; Kalantar-Nayestanaki, N; Fraiquin, H; Eads, A; Rinckel, T; Solberg, K

    1999-01-01

    A set of two multi-wire proportional chambers with a central hole has been designed and built in a KVI-IUCF collaboration. These chambers, used for detecting charged particles with atomic masses up to A = 4 and energies up to 200 MeV, are highly efficient with efficiencies of 97-98% per plane at a c

  6. Influence of the non-homogeneity of Ir-192 wires in calibration of well chambers

    Science.gov (United States)

    Pérez-Calatayud, J.; Ballester, F.; Granero, D.; Brosed, A.

    2003-12-01

    All international recommendations point out as necessary the calibration or verification of the reference air kerma rate (RAKR) for brachytherapy sources (independent of manufacturer established value) prior to their clinical use. The most common procedure for RAKR measurement in iridium wires is based on the use of well chambers with specific inserts that set the wire in a fixed position; previously, the electrometer plus well chamber with insert (EWI) was calibrated by using a source obtained from an accredited laboratory for which the RKAR was established precisely, called the 'reference' source. The distribution of Ir-192 material in the wire could be not perfectly homogeneous all along its length, and in this case the influence of these inhomogeneities in the calibration process should be studied. This paper focuses on the evaluation of this topic and an analytical and experimental study is presented taking into account the non-homogeneity of Ir-192 material along the wire for both the reference source (of length 14 cm) and a wire of unknown RAKR. This study is based on measurements with a 1 cm iridium wire on a rectilinear insert considering either of the two available reference sources (1 or 14 cm length), and has been experimentally evaluated using two typical well chambers. The main conclusion of the study is that if the non-homogeneity of the wires is lower than 5% the effect of non-homogeneity on RAKR measurements is negligible for rectilinear inserts even for short well chambers.

  7. Influence of the non-homogeneity of Ir-192 wires in calibration of well chambers

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Calatayud, J [Radiation Oncology Department, ' La Fe' University Hospital, Valencia (Spain); Ballester, F [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, and Instituto de FIsica Corpuscular (IFIC), Burjassot (Spain); Granero, D [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, and Instituto de FIsica Corpuscular (IFIC), Burjassot (Spain); Brosed, A [CIEMAT, Ministerio de Ciencia y TecnologIa, Madrid (Spain)

    2003-12-07

    All international recommendations point out as necessary the calibration or verification of the reference air kerma rate (RAKR) for brachytherapy sources (independent of manufacturer established value) prior to their clinical use. The most common procedure for RAKR measurement in iridium wires is based on the use of well chambers with specific inserts that set the wire in a fixed position; previously, the electrometer plus well chamber with insert (EWI) was calibrated by using a source obtained from an accredited laboratory for which the RKAR was established precisely, called the 'reference' source. The distribution of Ir-192 material in the wire could be not perfectly homogeneous all along its length, and in this case the influence of these inhomogeneities in the calibration process should be studied. This paper focuses on the evaluation of this topic and an analytical and experimental study is presented taking into account the non-homogeneity of Ir-192 material along the wire for both the reference source (of length 14 cm) and a wire of unknown RAKR. This study is based on measurements with a 1 cm iridium wire on a rectilinear insert considering either of the two available reference sources (1 or 14 cm length), and has been experimentally evaluated using two typical well chambers. The main conclusion of the study is that if the non-homogeneity of the wires is lower than 5% the effect of non-homogeneity on RAKR measurements is negligible for rectilinear inserts even for short well chambers.

  8. Construction and performance of large wire spark chambers with magnetostrictive read-out

    CERN Document Server

    Grayer, G; Dietl, H; Hyams, Bernard David; Jones, C; Koch, W; Lorenz, E; Lütjens, G; Männer, W; Meissburger, J; Stierlin, U; Weilhammer, P

    1972-01-01

    Describes the construction and performance of wire spark chambers having an active area of 3.60*0.90 m/sup 2/, a gap of 10 mm, and a wire spacing of 1 mm. Magnetostrictive read-out from both planes gives two coordinate values per chamber. Chambers of this type, together with smaller ones of similar construction, have been part of a magnet spectrometer which performed reliably between May 1970 and May 1971; during this time they were pulsed approximately 10/sup 7/ times. (9 refs).

  9. Some results on the ageing of wire chambers with dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Jibaly, M.; Chrusch, P. Jr.; Hilgenberg, G.; Majewski, S.; Wojcik, R.; Weintraub, R.; Sauli, F.

    1988-12-01

    Ageing results of three test wire detectors when filled with dimethyl ether (DME) are presented. DME gas was analyzed before and during the tests for the presence of electronegative impurities, such as Freons. A strong dependence of the rate of ageing on the wire composition was observed. The resistive wires, such as Stablohm and Nicotin, produced fast ageing. Also, even the best available purified DME, as of today, used with gold-plated wires, produced some slow ageing. The rate of amplitude decrease depended on the Freon impurity level.

  10. Charge production in thin gap multi-wire chambers

    CERN Document Server

    Mincer, A I; Goldberg, J J; Gernitzky, Y; Lazic, D; Lupu, N Z; Robins, S; Rozen, Y; Tarem, S

    2000-01-01

    Resistive cathode thin gap chambers (TGCs) have been used as particle detectors in high-energy physics experiments for more than a decade. A quantitative understanding of charge production mechanisms in TGCs has been developed and a simulation program produced to accurately describe the expected response from a chamber as a function of its design and operating parameters. This simulation is based upon a description of the processes of electron cluster production, drift and avalanche effects and space charge contributions from residual ions. Improved measurements of chamber performance are presented, and the parameters of the simulation have been fitted to these data yielding values consistent with estimates based on the physical mechanisms involved. Sensitivity of chamber timing and amplification properties to operating parameters is discussed.

  11. Neutron decay measurements with a helium-filled time projection chamber

    Energy Technology Data Exchange (ETDEWEB)

    Schreckenbach, K. (Institut Max von Laue - Paul Langevin, 38 - Grenoble (France)); Azuelos, G. (British Columbia Univ., Vancouver (Canada). TRIUMF Facility); Grivot, P. (Grenoble-1 Univ., 38 (France). Inst. des Sciences Nucleaires); Kossakowski, R.; Liaud, P. (Universite de Savoie, 73 - Chambery (France) Grenoble-1 Univ., 74 - Annecy (France). Lab. de Physique des Particules)

    1989-11-20

    A helium-filled time projection chamber was developed for in-beam detection of electrons from the free neutron decay. In a first experiment the neutron lifetime was determined as {tau}{sub n}=878(31) s. (orig.).

  12. Developments in plastic wire chambers operated in the limited streamer mode (LSM detectors)

    Science.gov (United States)

    Laakso, Mikko; Kurvinen, Kari; Orava, Risto

    1988-12-01

    We have calculated the photon detection efficiency of a wire chamber constructed with conductive nylon-66 plastic as cathode material in the photon energy range of 100 keV-1 MeV. The calculated results are compared with the results obtained with a Monte Carlo simulation using the FLUKA [1] transport code and with experimental results. We have also calculated the efficiency for copper and compared these two cathode materials. The comparison shows that wire chambers with nylon and copper cathodes are equally efficient in detecting the 100 keV-1 MeV photons. Furthermore, we have studied the different physical processes contributing to photon detection as well as the detection efficiency as a function of cathode thickness. Finally, we report some results from the first LSM detector operational tests performed with our new wire chamber testing device.

  13. Polymer Growth Rate in a Wire Chamber with Oxygen,Water, or Alcohol Gas Additives

    Energy Technology Data Exchange (ETDEWEB)

    Boyarski, Adam; /SLAC

    2008-07-02

    The rate of polymer growth on wires was measured in a wire chamber while the chamber was aged initially with helium-isobutane (80:20) gas, and then with either oxygen, water, or alcohol added to the gas. At the completion of the aging process for each gas mixture, the carbon content on the wires was measured in a SEM/EDX instrument. The same physical wires were used in all the gas mixtures, allowing measurement of polymer build up or polymer depletion by each gas additive. It is found that the rate of polymer growth is not changed by the presence of oxygen, water or alcohol. Conjecture that oxygen reduces breakdown by removing polymer deposits on field wires is negated by these measurements. Instead, it appears that the reduced breakdown is due to lower resistance in the polymer from oxygen ions being transported into the polymer. It is also observed that field wires bombarded by the electrons in the SEM and then placed back into the chamber show an abundance of single electrons being emitted, indicating that electron charge is stored in the polymer layer and that a high electric field is necessary to remove the charge.

  14. A new wire chamber front-end system, based on the ASD-8 B chip

    CERN Document Server

    Kruesemann, B A M; Ellinghaus, F; Frekers, D; Hagemann, M; Hannen, V M; Heynitz, H V; Heyse, J; Rakers, S; Sohlbach, H; Wörtche, H J

    1999-01-01

    The Focal-Plane Polarimeter (FPP) for the Big-Bite Spectrometer van den Berg (Nucl. Instr. and Meth. B 99 (1995) 637ff) at the KVI requires the read-out of four large-area MWPCs and two VDCs with 3872 wires in total. The EUROSUPERNOVA collaboration (SNOVA) developed a digital 16 channel preamplifier front-end board, housing two amplifier-shaper-discriminatorchips ASD-8 B. The main features of this board are a fast single-wire readout, a high integration density, a low power consumption and compatibility to common instrumentation standards. The board represents the first successfully running application of the ASD-8 for wire chamber readout. (author)

  15. X-ray detector for automatic exposure control using ionization chamber filled with xenon gas

    CERN Document Server

    Nakagawa, A; Yoshida, T

    2003-01-01

    This report refers to our newly developed X-ray detector for reliable automatic X-ray exposure control, which is to be widely used for X-ray diagnoses in various clinical fields. This new detector utilizes an ionization chamber filled with xenon gas, in contrast to conventional X-ray detectors which use ionization chambers filled with air. Use of xenon gas ensures higher sensitivity and thinner design of the detector. The xenon gas is completely sealed in the chamber, so that the influence of the changes in ambient environments is minimized. (author)

  16. A micro-gap, air-filled ionisation chamber as a detector for criticality accident dosimetry.

    Science.gov (United States)

    Murawski, Ł; Zielczyński, M; Golnik, N; Gryziński, M A

    2014-10-01

    A micro-gap air-filled ionisation chamber was designed for criticality dosimetry. The special feature of the chamber is its very small gap between electrodes of only 0.3 mm. This prevents ion recombination at high dose rates and minimises the influence of gas on secondary particles spectrum. The electrodes are made of polypropylene because of higher content of hydrogen in this material, when compared with soft tissue. The difference between neutron and gamma sensitivity in such chamber becomes practically negligible. The chamber's envelope contains two specially connected capacitors, one for polarising the electrodes and the other for collecting the ionisation charge.

  17. Particle tracking in kaon electroproduction with cathode-charge sampling in multi-wire proportional chambers

    CERN Document Server

    Achenbach, P; Bernauer, J C; Böhm, R; Bosnar, D; Bösz, M; Debenjak, L; Distler, M O; Esser, A; Friščić, I; de la Paz, M Gómez Rodríguez; Makek, M; Merkel, H; Müller, U; Nungesser, L; Pochodzalla, J; Potokar, M; Majos, S Sánchez; Schlimme, B S; Širca, S; Weinriefer, M; 10.1016/j.nima.2011.03.039

    2011-01-01

    Wire chambers are routinely operated as tracking detectors in magnetic spectrometers at high-intensity continuous electron beams. Especially in experiments studying reactions with small cross-sections the reaction yield is limited by the background rate in the chambers. One way to determine the track of a charged particle through a multi-wire proportional chamber (MWPC) is the measurement of the charge distribution induced on its cathodes. In practical applications of this read-out method, the algorithm to relate the measured charge distribution to the avalanche position is an important factor for the achievable position resolution and for the track reconstruction efficiency. An algorithm was developed for operating two large-sized MWPCs in a strong background environment with multiple-particle tracks. Resulting efficiencies were determined as a function of the electron beam current and on the signal amplitudes. Because of the different energy-losses of pions, kaons, and protons in the momentum range of the s...

  18. Restoring contaminated wires, removing gas contaminants, and aging studies of drift tube chambers

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Thomas E-mail: marshall@fnal.gov

    2003-12-01

    The original muon detection system of the Fermilab D0 colliding beam experiment contained 12,000 drift cells 10 cmx5 cm in cross-section and up to 580 cm in length. The gas mixture used was Ar/CF{sub 4}/CO{sub 2} (90:6:4). There was one recycling gas system for all the chambers. During the first year of operation, it was discovered that inefficient cells, all in regions of high radiation, had a contaminating shell of crud coating their wires. The source of the contaminant was outgassing of the cathode pads, which were made from a laminate of fiberglass and epoxy/polyester resin, with a copper cladding on one surface. The vapor formed a brittle sheath on the wires, but only in regions of high current discharge due to radiation from the accelerator and colliding beams. A method for cleaning wires in place was devised. By heating the wire quickly to a temperature close to the melting temperature of gold, the sheath was ripped to shreds and blown away. The procedure for 'zapping' wires and for removing the contaminating vapor is presented. The upgraded D0 experiment now uses Iarocci-type mini-drift tubes for the forward muon system. The results of aging tests for these chambers are also presented.

  19. Electron attachment of oxygen in a drift chamber filled with xenon + 10% methane

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, Y.; Hayashibara, I.; Ohsugi, T.; Sakanoue, T.; Taketani, A.; Terunuma, N.; Suzuki, Y.; Tsukamoto, A.; Yamamoto, H.; Fukushima, Y.

    1988-06-01

    The existence of O/sub 2/ contamination attenuates the pulse height and degrades its resolution in a drift chamber filled with xenon-methane (90/10) gas. The first measurement of the electron attachment coefficient due to oxygen in such a mixture is reported.

  20. Electron attachment of oxygen in a drift chamber filled with xenon + 10% methane

    Science.gov (United States)

    Chiba, Y.; Hayashibara, I.; Ohsugi, T.; Sakanoue, T.; Taketani, A.; Terunuma, N.; Suzuki, Y.; Tsukamoto, A.; Yamamoto, H.; Fukushima, Y.; Kohriki, T.; Nakamura, S.; Sakuda, M.; Watase, Y.

    1988-06-01

    The existence of O 2 contamination attenuates the pulse height and degrades its resolution in a drift chamber filled with xenon-methane (90/10) gas. The first measurement of the electron attachment coefficient due to oxygen in such a mixture is reported.

  1. Front-end Electronics Test for the LHCb Muon Wire Chambers

    CERN Document Server

    Nobrega, R; Carboni, G; Massafferri, A; Santovetti, E

    2007-01-01

    This document describes the apparatus and procedures implemented to test Multi Wire Proportional Chambers (MWPC) after front-end assembly for the LHCb Muon Detector. Results of measurements of key noise parameters are also described. Given a fully equipped chamber, this system is able to diagnose every channel performing an analysis of front-end output drivers’ response and noise rate versus threshold. Besides, it allows to assess if the noise rate at the experiment threshold region is within appropriate limits. Aiming at an automatic, fast and user-friendly system for mass production tests of MWPC, the project has foreseen as well electronic identification of every chamber and front-end board, and data archiving in such a way to make it available to the Experiment Control System (ECS) while in operation.

  2. High-resolution ion pulse ionization chamber with air filling for the Rn-222 decays detection

    CERN Document Server

    Gavrilyuk, Yu M; Gezhaev, A M; Etezov, R A; Kazalov, V V; Kuzminov, V V; Panasenko, S I; Ratkevich, S S; Tekueva, D A; Yakimenko, S P

    2015-01-01

    The construction and characteristics of the cylindrical ion pulse ionization chamber (CIPIC) with a working volume of 3.2 L are described. The chamber is intended to register alpha-particles from the $^{222}$Rn and its daughter's decays in the filled air sample. The detector is less sensitive to electromagnetic pick-ups and mechanical noises. The digital pulse processing method is proposed to improve the energy resolution of the ion pulse ionization chamber. An energy resolution of 1.6% has been achieved for the 5.49 MeV alpha-line. The dependence of the energy resolution on high voltage and working media pressure has been investigated and the results are presented.

  3. High-resolution ion pulse ionization chamber with air filling for the 222Rn decays detection

    Science.gov (United States)

    Gavrilyuk, Yu. M.; Gangapshev, A. M.; Gezhaev, A. M.; Etezov, R. A.; Kazalov, V. V.; Kuzminov, V. V.; Panasenko, S. I.; Ratkevich, S. S.; Tekueva, D. A.; Yakimenko, S. P.

    2015-11-01

    The construction and characteristics of the cylindrical ion pulse ionization chamber (CIPIC) with a working volume of 3.2 L are described. The chamber is intended to register α-particles from the 222Rn and its daughter's decays in the filled air sample. The detector is less sensitive to electromagnetic pick-ups and mechanical noises. The digital pulse processing method is proposed to improve the energy resolution of the ion pulse ionization chamber. An energy resolution of 1.6% has been achieved for the 5.49 MeV α-line. The dependence of the energy resolution on high voltage and working media pressure has been investigated and the results are presented.

  4. Modeling Integrated High-Yield IFE Target Explosions in Xenon Filled Chambers

    Science.gov (United States)

    Fatenejad, Milad; Moses, Gregory

    2010-11-01

    We will present the results of several radiation-hydrodynamics simulations which model the aftermath of an exploding high yield (200 MJ) indirect drive target in a xenon filled reactor chamber. The goal is to determine the radial extent to which debris from the target and hohlraum expands into the target chamber. The 1D radiation-hydrodynamics code BUCKY is used to perform integrated simulations of the target explosion beginning from ignition and includes interactions between the chamber gas and tungsten first wall. The 3D radiation-hydrodynamics code Cooper will be used to model the growth of fluid instabilities as the target material expands into the xenon gas. Cooper will also be used to investigate the early-time interaction between the burning target and hohlraum shortly after ignition.

  5. Second coordinate readout in drift chambers by timing of the electromagnetic wave propagating along the anode wire

    Energy Technology Data Exchange (ETDEWEB)

    Boie, R.A.; Radeka, V.; Rehak, P.; Xi, D.M.

    1980-11-01

    The feasibility of using an anode wire and surrounding electrodes in drift chambers as a transmission line for second coordinate readout has been studied. The method is based on propagation of the electromagnetic wave along the anode wire is determined by measurement, in an optimized electronic readout system, of the time difference between the arrivals of the signal to the ends of the wire. The resolution obtained on long wires (approx. 2 meters) is about 2 cm FWHM for minimum ionizing particles at a gas gain of approx. = 10/sup 5/.

  6. A liquid-filled ionization chamber for high precision relative dosimetry.

    Science.gov (United States)

    González-Castaño, D M; Gómez, F; Brualla, L; Roselló, J V; Planes, D; Sánchez, M; Pombar, M

    2011-04-01

    Radiosurgery and intensity modulated radiation therapy (IMRT) treatments are based on the delivery of narrow and/or irregularly shaped megavoltage photon beams. This kind of beams present both lack of charged particle equilibrium and steep dose gradients. Quality assurance (QA) measurements involved in these techniques must therefore be carried out with a dosimeter featuring high small volume. In order to obtain a good signal to noise ratio, a relatively dense material is needed as active medium. Non-polar organic liquids were proposed as active mediums with both good tissue equivalence and showing high signal to noise ratio. In this work, a liquid-filled ionization chamber is presented. Some results acquired with this detector in relative dosimetry are studied and compared with results obtained with unshielded diode. Medium-term stability measurements were also carried out and its results are shown. The liquid-filled ionization chamber presented here shows its ability to perform profile measurements and penumbrae determination with excellent accuracy. The chamber features a proper signal stability over the period studied.

  7. Air filled ionization chambers and their response to high LET radiation

    DEFF Research Database (Denmark)

    Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

    Background Air filled ionization chambers (ICs) are widely used for absolute dosimetry, not only in photon beams but also in beams of heavy charged particles. Within the IC, electron hole pairs are generated by the energy deposition originating from incoming radiation. High-LET particles create...... structure theory. More specifically, we solved the equation for the geometrical setup of the Bragg-peak IC, which is a plane parallel IC with a 2 mm spacing between the electrodes. The sensitive volume of the IC is located in a thermoplastic housing of several mm thickness. Results We compare...

  8. Precision templates for gluing wire holding pieces to chamber frames; Plantillas de precision para la construccion de detectores de muones

    Energy Technology Data Exchange (ETDEWEB)

    Berdugo, J.; Burgos, C; Cerrada, M.

    1995-07-01

    In the present report we describe the procedure which has been used in order to optimize the precision obtained when positioning forward backward muon chamber sensor wire planes of the L3 experiment at CERN. With templates produced at CIEMAT a precision of about 10 microns. In sizes of the order of 3 meters. has been achieved. (Author) 2 refs.

  9. Study of a multi-wire proportional chamber with a cathode strip and delay-line readout

    Institute of Scientific and Technical Information of China (English)

    HAN Li-Ying; LI Qi-Te; Q. Faisal; GE Yu-Cheng; IU Hong-Tao; YE Yan-Lin

    2009-01-01

    The design principle for a multi-wire proportional chamber with a cathode strip and delay-line readout is described. A prototype chamber of a size of 10 cm ~ l0 cm was made together with the readout electronics circuit. A very clean signal with very low background noise was obtained by applying a transformer between the delay-line and the pre-amplifier in order to match the resistance. Along the anode wire direction a position resolution of less than 0.5 mm was achieved with a 55Fe-5.9 keV X ray source. The simple structure, large effective area and high position resolution allow the application of a gas chamber of this kind to many purposes.

  10. Specific features of X-ray generation by plasma focus chambers with deuterium and deuterium-tritium fillings

    Science.gov (United States)

    Dulatov, A. K.; Krapiva, P. S.; Lemeshko, B. D.; Mikhailov, Yu. V.; Moskalenko, I. N.; Prokuratov, I. A.; Selifanov, A. N.

    2016-01-01

    The process of hard X-ray (HXR) generation in plasma focus (PF) chambers was studied experimentally. The radiation was recorded using scintillation detectors with a high time resolution and thermoluminescent detectors in combination with the method of absorbing filters. Time-resolved analysis of the processes of neutron and X-ray generation in PFs is performed. The spectra of HXR emission from PF chambers with deuterium and deuterium-tritium fillings are determined. In experiments with PF chambers filled with a deuterium-tritium mixture, in addition to the HXR pulse with photon energies of up to 200-300 keV, a γ-ray pulse with photon energies of up to 2.5-3.0 MeV is recorded, and a mechanism of its generation is proposed.

  11. Heavy ion beam propagation through a gas-filled chamber for inertial confinement fusion

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, Nigel Oswald [Univ. of California, Berkeley, CA (United States)

    1996-10-01

    The work presented here evaluates the dynamics of a beam of heavy ions propagating through a chamber filled with gas. The motivation for this research stems from the possibility of using heavy ion beams as a driver in inertial confinement fusion reactors for the purpose of generating electricity. Such a study is important in determining the constraints on the beam which limit its focus to the small radius necessary for the ignition of thermonuclear microexplosions which are the source of fusion energy. Nuclear fusion is the process of combining light nuclei to form heavier ones. One possible fusion reaction combines two isotopes of hydrogen, deuterium and tritium, to form an alpha particle and a neutron, with an accompanying release of ~17.6 MeV of energy. Generating electricity from fusion requires that we create such reactions in an efficient and controlled fashion, and harness the resulting energy. In the inertial confinement fusion (ICF) approach to energy production, a small spherical target, a few millimeters in radius, of deuterium and tritium fuel is compressed so that the density and temperature of the fuel are high enough, ~200 g/cm3 and ~20 keV, that a substantial number of fusion reactions occur; the pellet microexplosion typically releases ~350 MJ of energy in optimized power plant scenarios.

  12. Detecting MLC errors in stereotactic radiotherapy plans with a liquid filled ionization chamber array.

    Science.gov (United States)

    O'Connor, Patrick; Seshadri, Venkatakrisnan; Charles, Paul

    2016-03-01

    Quality assurance of stereotactic radiotherapy demands the use of equipment with the highest resolution and sensitivity available. This study examines the sensitivity of a commercially available liquid-filled ionization chamber array--the Octavius 1000 SRS (PTW, Frieburg, Germany) for detecting small (sub-millimetre) multi-leaf collimator (MLC) alignment errors in static square fields (side length 16-40 mm). Furthermore, the effectiveness of detecting small MLC errors in clinical stereotactic radiotherapy patient plans using the device was also evaluated. The commonly used gamma pass rate metric (of the measurements compared with treatment planning system generated results) was used. The gamma pass rates were then evaluated as a function of MLC position error (MLC error size 0.1-2.5 mm). The detector array exhibited a drop in pass rate between plans without error and those which had MLC errors induced. For example a drop in pass rate of 4.5% (gamma criteria 3%, 1 mm) was observed when a 0.8 mm error was introduced into a 16 mm square field. Furthermore the drop in pass rate increased as the MLC position error increased. This study showed that the Octavius 1000 SRS array could be a useful tool for applications requiring the detection of small geometric delivery uncertainties.

  13. Heavy ion beam propagation through a gas-filled chamber for inertial confinement fusion

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, N.O.

    1996-10-01

    The work presented here evaluates the dynamics of a beam of heavy ions propagating through a chamber filled with gas. The motivation for this research stems from the possibility of using heavy ion beams as a driver in inertial confinement fusion reactors for the purpose of generating electricity. Such a study is important in determining the constraints on the beam which limit its focus to the small radius necessary for the ignition of thermonuclear microexplosions which are the source of fusion energy. Nuclear fusion is the process of combining light nuclei to form heavier ones. One possible fusion reaction combines two isotopes of hydrogen, deuterium and tritium, to form an alpha particle and a neutron, with an accompanying release of {approximately}17.6 MeV of energy. Generating electricity from fusion requires that we create such reactions in an efficient and controlled fashion, and harness the resulting energy. In the inertial confinement fusion (ICF) approach to energy production, a small spherical target, a few millimeters in radius, of deuterium and tritium fuel is compressed so that the density and temperature of the fuel are high enough, {approximately}200 g/cm{sup 3} and {approximately}20 keV, that a substantial number of fusion reactions occur; the pellet microexplosion typically releases {approximately}350 MJ of energy in optimized power plant scenarios.

  14. Expansion characteristics of twin combustion gas jets with high pressure in cylindrical filling liquid chamber

    Institute of Scientific and Technical Information of China (English)

    薛晓春; 余永刚; 张琦

    2013-01-01

    To deal with the problem of how to control the interior ballistic stability in the bulk-loaded liquid propellant gun, the expansion and mixing process of the twin combustion-gas jets with high temperature and pressure in a liquid medium is studied in the cylindrical filling liquid chamber. A series of the jet expansion shapes is obtained by using a high-speed photographic system. The influences of the jet pressure on the jet expansion shape are discussed. Based on the experiments, the three-dimensional mathematical model is established. The expansion processes of the twin gas jets in the liquid medium are simulated by means of fluent to get the pressure, density, temperature, velocity contours and evolutionary process of vortices. Results show that the jet external outline and tops are all irregular. The Kelvin-Helmholtz instability is shown in the whole expansion process. The numerical simulation results of the axial displacement of the twin gas jets in liquid agree well with the experiment.

  15. High-resolution ion pulse ionization chamber with air filling for the {sup 222}Rn decays detection

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilyuk, Yu.M.; Gangapshev, A.M.; Gezhaev, A.M.; Etezov, R.A.; Kazalov, V.V.; Kuzminov, V.V. [Baksan Neutrino Observatory,Institute for Nuclear Research RAS, 361609 Neutrino (Russian Federation); Panasenko, S.I. [V.N.Karazin Kharkiv National University, 61022 Kharkiv (Ukraine); Ratkevich, S.S., E-mail: ssratk@gmail.com [V.N.Karazin Kharkiv National University, 61022 Kharkiv (Ukraine); Tekueva, D.A.; Yakimenko, S.P. [Baksan Neutrino Observatory,Institute for Nuclear Research RAS, 361609 Neutrino (Russian Federation)

    2015-11-21

    The construction and characteristics of the cylindrical ion pulse ionization chamber (CIPIC) with a working volume of 3.2 L are described. The chamber is intended to register α-particles from the {sup 222}Rn and its daughter's decays in the filled air sample. The detector is less sensitive to electromagnetic pick-ups and mechanical noises. The digital pulse processing method is proposed to improve the energy resolution of the ion pulse ionization chamber. An energy resolution of 1.6% has been achieved for the 5.49 MeV α-line. The dependence of the energy resolution on high voltage and working media pressure has been investigated and the results are presented. - Highlights: • The construction and characteristics of the cylindrical ion pulse ionization chamber (CIPIC) with a working volume of 3.2 L are described. • The chamber is intended to register alpha-particles from {sup 222}Rn and its daughter's decays in the filled air sample. • The detector is less sensitive to electromagnetic pick-ups and mechanical noises. • An energy resolution of 1.6% has been achieved for the 5.49 MeV alpha-line. The dependence of the energy resolution on high voltage and working media pressure have been investigated and the results are presented.

  16. DAVID--a translucent multi-wire transmission ionization chamber for in vivo verification of IMRT and conformal irradiation techniques.

    Science.gov (United States)

    Poppe, B; Thieke, C; Beyer, D; Kollhoff, R; Djouguela, A; Rühmann, A; Willborn, K C; Harder, D

    2006-03-07

    Permanent in vivo verification of IMRT photon beam profiles by a radiation detector with spatial resolution, positioned on the radiation entrance side of the patient, has not been clinically available so far. In this work we present the DAVID system, which is able to perform this quality assurance measurement while the patient is treated. The DAVID system is a flat, multi-wire transmission-type ionization chamber, placed in the accessory holder of the linear accelerator and constructed from translucent materials in order not to interfere with the light field. Each detection wire of the chamber is positioned exactly in the projection line of a MLC leaf pair, and the signal of each wire is proportional to the line integral of the ionization density along this wire. Thereby, each measurement channel essentially presents the line integral of the ionization density over the opening width of the associated leaf pair. The sum of all wire signals is a measure of the dose-area product of the transmitted photon beam and of the total radiant energy administered to the patient. After the dosimetric verification of an IMRT plan, the values measured by the DAVID system are stored as reference values. During daily treatment the signals are re-measured and compared to the reference values. A warning is output if there is a deviation beyond a threshold. The error detection capability is a leaf position error of less than 1 mm for an isocentric 1 cm x 1 cm field, and of 1 mm for an isocentric 20 cm x 20 cm field.

  17. The stability of liquid-filled matrix ionization chamber electronic portal imaging devices for dosimetry purposes.

    Science.gov (United States)

    Louwe, R J W; Tielenburg, R; van Ingen, K M; Mijnheer, B J; van Herk, M B

    2004-04-01

    This study was performed to determine the stability of liquid-filled matrix ionization chamber (LiFi-type) electronic portal imaging devices (EPID) for dosimetric purposes. The short- and long-term stability of the response was investigated, as well as the importance of factors influencing the response (e.g., temperature fluctuations, radiation damage, and the performance of the electronic hardware). It was shown that testing the performance of the electronic hardware as well as the short-term stability of the imagers may reveal the cause of a poor long-term stability of the imager response. In addition, the short-term stability was measured to verify the validity of the fitted dose-response curve immediately after beam startup. The long-term stability of these imagers could be considerably improved by correcting for room temperature fluctuations and gradual changes in response due to radiation damage. As a result, the reproducibility was better than 1% (1 SD) over a period of two years. The results of this study were used to formulate recommendations for a quality control program for portal dosimetry. The effect of such a program was assessed by comparing the results of portal dosimetry and in vivo dosimetry using diodes during the treatment of 31 prostate patients. The improvement of the results for portal dosimetry was consistent with the deviations observed with the reproducibility tests in that particular period. After a correction for the variation in response of the imager, the average difference between the measured and prescribed dose during the treatment of prostate patients was -0.7%+/-1.5% (1 SD), and -0.6%+/-1.1% (1 SD) for EPID and diode in vivo dosimetry, respectively. It can be concluded that a high stability of the response can be achieved for this type of EPID by applying a rigorous quality control program.

  18. A numerical model of initial recombination for high-LET irradiation: Application to liquid-filled ionization chambers

    Science.gov (United States)

    Aguiar, P.; Pardo-Montero, J.

    2016-02-01

    In this paper we present a numerical model of initial recombination in media irradiated with high linear energy transfer (LET) ions, which relies on an amorphous track model of ionization of high LET particles, and diffusion, drift and recombination of ionized charge carriers. The model has fundamental applications for the study of recombination in non-polar liquids, as well as practical ones, like in modelling hadrontherapy dosimetry with ionization chambers. We have used it to study the response of liquid-filled ionization chambers to hadrontherapy beams: dependence of initial recombination on ion species, energy and applied external electric field.

  19. A Concept for a Low Pressure Noble Gas Fill Intervention in the IFE Fusion Test Facility (FTF) Target Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Gentile, C. A.; Blanchard, W. R.; Kozub, T. A.; Aristova, M.; McGahan, C.; Natta, S.; Pagdon, K.; Zelenty, J.

    2010-01-14

    An engineering evaluation has been initiated to investigate conceptual engineering methods for implementing a viable gas shield strategy in the Fusion Test Facility (FTF) target chamber. The employment of a low pressure noble gas in the target chamber to thermalize energetic helium ions prior to interaction with the wall could dramatically increase the useful life of the first wall in the FTF reactor1. For the purpose of providing flexibility, two target chamber configurations are addressed: a five meter radius sphere and a ten meter radius sphere. Experimental studies at Nike have indicated that a low pressure, ambient gas resident in the target chamber during laser pulsing does not appear to impair the ability of laser light from illuminating targets2. In addition, current investigations into delivering, maintaining, and processing low pressure gas appear to be viable with slight modification to current pumping and plasma exhaust processing technologies3,4. Employment of a gas fill solution for protecting the dry wall target chamber in the FTF may reduce, or possibly eliminate the need for other attenuating technologies designed for keeping He ions from implanting in first wall structures and components. The gas fill concept appears to provide an effective means of extending the life of the first wall while employing mostly commercial off the shelf (COTS) technologies. Although a gas fill configuration may provide a methodology for attenuating damage inflicted on chamber surfaces, issues associated with target injection need to be further analyzed to ensure that the gas fill concept is viable in the integrated FTF design5. In the proposed system, the ambient noble gas is heated via the energetic helium ions produced by target detonation. The gas is subsequently cooled by the chamber wall to approximately 800oC, removed from the chamber, and processed by the chamber gas processing system (CGPS). In an optimized scenario of the above stated concept, the chamber

  20. Pressure-assisted melt-filling and optical characterization of Au nano-wires in microstructured fibers.

    Science.gov (United States)

    Lee, H W; Schmidt, M A; Russell, R F; Joly, N Y; Tyagi, H K; Uebel, P; Russell, P St J

    2011-06-20

    We report a novel splicing-based pressure-assisted melt-filling technique for creating metallic nanowires in hollow channels in microstructured silica fibers. Wires with diameters as small as 120 nm (typical aspect ration 50:1) could be realized at a filling pressure of 300 bar. As an example we investigate a conventional single-mode step-index fiber with a parallel gold nanowire (wire diameter 510 nm) running next to the core. Optical transmission spectra show dips at wavelengths where guided surface plasmon modes on the nanowire phase match to the glass core mode. By monitoring the side-scattered light at narrow breaks in the nanowire, the loss could be estimated. Values as low as 0.7 dB/mm were measured at resonance, corresponding to those of an ultra-long-range eigenmode of the glass-core/nanowire system. By thermal treatment the hollow channel could be collapsed controllably, permitting creation of a conical gold nanowire, the optical properties of which could be monitored by side-scattering. The reproducibility of the technique and the high optical quality of the wires suggest applications in fields such as nonlinear plasmonics, near-field scanning optical microscope tips, cylindrical polarizers, optical sensing and telecommunications.

  1. Initial recombination in the track of heavy charged particles: Numerical solution for air filled ionization chambers

    DEFF Research Database (Denmark)

    Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

    2012-01-01

    Introduction Modern particle therapy facilities enable sub-millimeter precision in dose deposition. Here, also ionization chambers (ICs) are used, which requires knowledge of the recombination effects. Up to now, recombination is corrected using phenomenological approaches for practical reasons...

  2. 7 CFR 1755.860 - RUS specification for filled buried wires.

    Science.gov (United States)

    2010-01-01

    ... (AWG) 22 24 Pairs 2 2 3 3 (3) All wires sold to RUS borrowers for projects involving RUS loan funds... Materials specifications (ASTM) A 505-87, Standard Specification for Steel, Sheet and Strip, Alloy, Hot..., Copper Alloy, and Copper-Clad Stainless Steel Sheet and Strip for Electrical Cable Shielding; ASTM D...

  3. Dark Matter Limits From a 2L C3F8 Filled Bubble Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Alan Edward [Univ. of Chicago, IL (United States)

    2015-12-01

    The PICO-2L C3F8 bubble chamber search forWeakly Interacting Massive Particle (WIMP) dark matter was operated in the SNOLAB underground laboratory at the same location as the previous CF3I lled COUPP-4kg detector. Neutron calibrations using photoneutron sources in C3F8 and CF3I lled calibration bubble chambers were performed to verify the sensitivity of these target uids to dark matter scattering. This data was combined with similar measurements using a low-energy neutron beam at the University of Montreal and in situ calibrations of the PICO-2L and COUPP-4kg detectors. C3F8 provides much greater sensitivity to WIMP-proton scattering than CF3I in bubble chamber detectors. PICO-2L searched for dark matter recoils with energy thresholds below 10 keV. Radiopurity assays of detector materials were performed and the expected neutron recoil background was evaluated to be 1.6+0:3

  4. SCOUT: a small vacuum chamber for nano-wire grid polarizer tests in the ultraviolet band

    Science.gov (United States)

    Landini, F.; Pancrazzi, M.; Totaro, M.; Pennelli, G.; Romoli, M.

    2012-01-01

    Within the Section of Astronomy of the Department of Physics and Astronomy of the University of Firenze, Italy), the XUVLab laboratory is active since 1998 dedicated to technological development, mainly UV oriented. The technological research is focused both on electronics and optics. Our last approach is dedicated to the development of innovative wiregrid polarizers optimized to work in transmission at 121.6 nm. The manufacturing of such optical devices requires advanced technological expertise and suitable experimental structures. First, nanotechnology capability is necessary, in order to build several tiny parallel conductive lines separated by tens of nanometers on wide areas to be macroscopically exploitable in an optical laboratory. Moreover, the characterization of such an advanced optical device has to be performed in vacuum, being air absorptive at 121.6 nm. A dedicated small vacuum chamber, SCOUT (Small Chamber for Optical UV Tests) was developed within our laboratory in order to perform practical and fast measurements. SCOUT hosts an optical bench and is equipped with several opening flanges, in order to be as flexible as possible. The flexibility that has been reached with SCOUT allows us to use the chamber beyond the goals it was thought for. It is exploitable by whatever compact (within 1 m) optical experiment that investigates the UV band of the spectrum.

  5. Monitored Drift Tube (MDT) chambers for precise measurement of muon trajectories in the ATLAS muon spectrometer.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    The basic detection component of the chamber is the cylindrical, aluminium, gas-filled MDT with its central tungsten rhenium wire. Each chamber is an assembly of two parallel multilayers of MDTs separated by a spacer frame. The chambers are pictured here in building 887 on the Prévessin site where they are being tested.

  6. Design and Performance of a Custom ASIC Digitizer for Wire Chamber Readout in 65 nm CMOS Technology

    CERN Document Server

    Lee, MyeongJae; Chang, Jessica K; Ding, Dawei; Gnani, Dario; Grace, Carl R; Jones, John A; Kolomensky, Yury G; von der Lippe, Henrik; Mcvittie, Patrick J; Stettler, Matthew W; Walder, Jean-Pierre

    2015-01-01

    We present the design and performance of a prototype ASIC digitizer for integrated wire chamber readout, implemented in 65 nm commercial CMOS technology. Each channel of the 4-channel prototype is composed of two 16-bit Time-to-Digital Converters (TDCs), one 8-bit Analog-to-Digital Converter (ADC), a front-end preamplifier and shaper, plus digital and analog buffers that support a variety of digitization chains. The prototype has a multiplexed digital backend that executes a state machine, distributes control and timing signals, and buffers data for serial output. Laboratory bench tests measure the absolute TDC resolution between 74 ps and 480 ps, growing with the absolute delay, and a relative time resolution of 19 ps. Resolution outliers due to cross-talk between clock signals and supply or reference voltages are seen. After calibration, the ADC displays good linearity and noise performance, with an effective number of bits of 6.9. Under normal operating conditions the circuit consumes 32 mW per channel. Po...

  7. Design and performance of a custom ASIC digitizer for wire chamber readout in 65 nm CMOS technology

    Science.gov (United States)

    Lee, M. J.; Brown, D. N.; Chang, J. K.; Ding, D.; Gnani, D.; Grace, C. R.; Jones, J. A.; Kolomensky, Y. G.; von der Lippe, H.; Mcvittie, P. J.; Stettler, M. W.; Walder, J.-P.

    2015-06-01

    We present the design and performance of a prototype ASIC digitizer for integrated wire chamber readout, implemented in 65 nm commercial CMOS technology. Each channel of the 4-channel prototype is composed of two 16-bit Time-to-Digital Converters (TDCs), one 8-bit Analog-to-Digital Converter (ADC), a front-end preamplifier and shaper, plus digital and analog buffers that support a variety of digitization chains. The prototype has a multiplexed digital backend that executes a state machine, distributes control and timing signals, and buffers data for serial output. Laboratory bench tests measure the absolute TDC resolution between 74 ps and 480 ps, growing with the absolute delay, and a relative time resolution of 19 ps. Resolution outliers due to cross-talk between clock signals and supply or reference voltages are seen. After calibration, the ADC displays good linearity and noise performance, with an effective number of bits of 6.9. Under normal operating conditions the circuit consumes 32 mW per channel. Potential design improvements to address the resolution drift and tails are discussed.

  8. Investigating ion recombination effects in a liquid-filled ionization chamber array used for IMRT QA measurements.

    Science.gov (United States)

    Knill, Cory; Snyder, Michael; Rakowski, Joseph T; Zhuang, Ling; Matuszak, Martha; Burmeister, Jay

    2016-05-01

    PTW's Octavius 1000 SRS array performs IMRT quality assurance (QA) measurements with liquid-filled ionization chambers (LICs) to allow closer detector spacing and higher resolution, compared to air-filled QA devices. However, reduced ion mobility in LICs relative to air leads to increased ion recombination effects and reduced collection efficiencies that are dependent on Linac pulse frequency and pulse dose. These pulse parameters are variable during an IMRT delivery, which affects QA results. In this study, (1) 1000 SRS collection efficiencies were measured as a function of pulse frequency and pulse dose, (2) two methods were developed to correct changes in collection efficiencies during IMRT QA measurements, and the effects of these corrections on QA pass rates were compared. To obtain collection efficiencies, the OCTAVIUS 1000 SRS was used to measure open fields of varying pulse frequency, pulse dose, and beam energy with results normalized to air-filled chamber measurements. Changes in ratios of 1000 SRS to chamber measured dose were attributed to changing collection efficiencies, which were then correlated to pulse parameters using regression analysis. The usefulness of the derived corrections was then evaluated using 6 MV and 10FFF SBRT RapidArc plans delivered to the OCTAVIUS 4D system using a TrueBeam (Varian Medical Systems) linear accelerator equipped with a high definition multileaf collimator. For the first correction, matlab software was developed that calculates pulse frequency and pulse dose for each detector, using measurement and DICOM RT Plan files. Pulse information is converted to collection efficiency, and measurements are corrected by multiplying detector dose by ratios of calibration to measured collection efficiencies. For the second correction the MU/min in the daily 1000 SRS calibration was chosen to match the average MU/min of the volumetric modulated arc therapy plan. Effects of the two corrections on QA results were examined by

  9. Investigating ion recombination effects in a liquid-filled ionization chamber array used for IMRT QA measurements

    Energy Technology Data Exchange (ETDEWEB)

    Knill, Cory, E-mail: knillcor@gmail.com; Snyder, Michael; Rakowski, Joseph T.; Burmeister, Jay [Department of Radiation Oncology, Karmanos Cancer Institute, Detroit, Michigan 48201 and Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan 48201 (United States); Zhuang, Ling [Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan 48201 (United States); Matuszak, Martha [Department of Radiation Oncology, University of Michigan Health System, Ann Arbor, Michigan 48109 (United States)

    2016-05-15

    Purpose: PTW’s Octavius 1000 SRS array performs IMRT quality assurance (QA) measurements with liquid-filled ionization chambers (LICs) to allow closer detector spacing and higher resolution, compared to air-filled QA devices. However, reduced ion mobility in LICs relative to air leads to increased ion recombination effects and reduced collection efficiencies that are dependent on Linac pulse frequency and pulse dose. These pulse parameters are variable during an IMRT delivery, which affects QA results. In this study, (1) 1000 SRS collection efficiencies were measured as a function of pulse frequency and pulse dose, (2) two methods were developed to correct changes in collection efficiencies during IMRT QA measurements, and the effects of these corrections on QA pass rates were compared. Methods: To obtain collection efficiencies, the OCTAVIUS 1000 SRS was used to measure open fields of varying pulse frequency, pulse dose, and beam energy with results normalized to air-filled chamber measurements. Changes in ratios of 1000 SRS to chamber measured dose were attributed to changing collection efficiencies, which were then correlated to pulse parameters using regression analysis. The usefulness of the derived corrections was then evaluated using 6 MV and 10FFF SBRT RapidArc plans delivered to the OCTAVIUS 4D system using a TrueBeam (Varian Medical Systems) linear accelerator equipped with a high definition multileaf collimator. For the first correction, MATLAB software was developed that calculates pulse frequency and pulse dose for each detector, using measurement and DICOM RT Plan files. Pulse information is converted to collection efficiency, and measurements are corrected by multiplying detector dose by ratios of calibration to measured collection efficiencies. For the second correction the MU/min in the daily 1000 SRS calibration was chosen to match the average MU/min of the volumetric modulated arc therapy plan. Effects of the two corrections on QA results were

  10. Experimental analysis of general ion recombination in a liquid-filled ionization chamber in high-energy photon beams

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Eunah; Seuntjens, Jan [Medical Physics Unit, McGill University, Montreal General Hospital (L5-113), 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada); Davis, Stephen [Department of Medical Physics, McGill University Health Centre, Montreal General Hospital (L5-112), 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada)

    2013-06-15

    Purpose: To study experimentally the general ion recombination effect in a liquid-filled ionization chamber (LIC) in high-energy photon beams. Methods: The general ion recombination effect on the response of a micro liquid ion chamber (microLion) was investigated with a 6 MV photon beam in normal and SRS modes produced from a Varian{sup Registered-Sign} Novalis Tx{sup TM} linear accelerator. Dose rates of the linear accelerator were set to 100, 400, and 1000 MU/min, which correspond to pulse repetition frequencies of 60, 240, and 600 Hz, respectively. Polarization voltages applied to the microLion were +800 and +400 V. The relative collection efficiency of the microLion response as a function of dose per pulse was experimentally measured with changing polarization voltage and pulse repetition frequencies and was compared with the theoretically calculated value. Results: For the 60 Hz pulse repetition frequency, the experimental relative collection efficiency was not different from the theoretical one for a pulsed beam more than 0.3% for both polarization voltages. For a pulsed radiation beam with a higher pulse repetition frequency, the experimental relative collection efficiency converged to the theoretically calculated efficiency for continuous beams. This result indicates that the response of the microLion tends toward the response to a continuous beam with increasing pulse repetition frequency of a pulsed beam because of low ion mobility in the liquid. Conclusions: This work suggests an empirical method to correct for differences in general ion recombination of a LIC between different radiation fields. More work is needed to quantitatively explain the LIC general ion recombination behavior in pulsed beams generated from linear accelerators.

  11. Characterization of a two-dimensional liquid-filled ion chamber detector array used for verification of the treatments in radiotherapy.

    Science.gov (United States)

    Markovic, Miljenko; Stathakis, Sotirios; Mavroidis, Panayiotis; Jurkovic, Ines-Ana; Papanikolaou, Nikos

    2014-05-01

    The purpose of the study is to investigate the characteristics of a two-dimensional (2D) liquid-filled ion chamber detector array, which is used for the verification of radiotherapy treatment plans that use small field sizes of up to 10 × 10 cm. The device used in this study was Octavius 1000 SRS model (PTW, Freiburg, Germany). Its 2D array of detectors consists of 977 liquid-filled ion chambers arranged over an area of 11 × 11 cm. The size of the detectors is 2.3 × 2.3 × 0.5 mm (volume of 0.003 cm(3)) and their spacing in the inner area of 5.5 × 5.5 cm is 2.5 mm center-to-center, whereas in the outer area it is 5 mm center-to-center. The detector reproducibility, dose linearity, and sensitivity to positional changes of the collimator were tested. Also, the output factors of field sizes ranging from 0.5 × 0.5 to 10 × 10 cm(2) both for open and wedged fields have been measured and compared against those measured by a pin-point ionization chamber, liquid filled microchamber, SRS diode, and EDR2 film. Its short-term reproducibility was within 0.2% and its medium and long-term reproducibility was within 0.5% (verified with air ionization chamber absolute dose measurements), which is an excellent result taking into account the daily fluctuation of the linear accelerator and the errors in the device setup reproducibility. The dose linearity and dose rate dependence were measured in the range of 0.5-85 Gy and 0.5-10 Gy min(-1), respectively, and were verified with air ionization chamber absolute dose measurements was within 3%. The measurements of the sensitivity showed that the 2D Array could detect millimetric collimator positional changes. The measured output factors showed an agreement of better than 0.3% with the pinpoint chamber and microliquid filled chamber for the field sizes between 3 × 3 and 10 × 10 cm(2). For field sizes down to 1 × 1 cm(2), the agreement with SRS diode and microliquid filled chamber is better than 2%. The measurements of open and

  12. Characterization of a two-dimensional liquid-filled ion chamber detector array used for verification of the treatments in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, Miljenko, E-mail: markovic@livemail.uthscsa.edu; Stathakis, Sotirios; Mavroidis, Panayiotis; Jurkovic, Ines-Ana; Papanikolaou, Nikos [Department of Radiation Oncology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas 78229 (United States)

    2014-05-15

    Purpose: The purpose of the study is to investigate the characteristics of a two-dimensional (2D) liquid-filled ion chamber detector array, which is used for the verification of radiotherapy treatment plans that use small field sizes of up to 10 × 10 cm. Methods: The device used in this study was Octavius 1000 SRS model (PTW, Freiburg, Germany). Its 2D array of detectors consists of 977 liquid-filled ion chambers arranged over an area of 11 × 11 cm. The size of the detectors is 2.3 × 2.3 × 0.5 mm (volume of 0.003 cm{sup 3}) and their spacing in the inner area of 5.5 × 5.5 cm is 2.5 mm center-to-center, whereas in the outer area it is 5 mm center-to-center. The detector reproducibility, dose linearity, and sensitivity to positional changes of the collimator were tested. Also, the output factors of field sizes ranging from 0.5 × 0.5 to 10 × 10 cm{sup 2} both for open and wedged fields have been measured and compared against those measured by a pin-point ionization chamber, liquid filled microchamber, SRS diode, and EDR2 film. Results: Its short-term reproducibility was within 0.2% and its medium and long-term reproducibility was within 0.5% (verified with air ionization chamber absolute dose measurements), which is an excellent result taking into account the daily fluctuation of the linear accelerator and the errors in the device setup reproducibility. The dose linearity and dose rate dependence were measured in the range of 0.5–85 Gy and 0.5–10 Gy min{sup −1}, respectively, and were verified with air ionization chamber absolute dose measurements was within 3%. The measurements of the sensitivity showed that the 2D Array could detect millimetric collimator positional changes. The measured output factors showed an agreement of better than 0.3% with the pinpoint chamber and microliquid filled chamber for the field sizes between 3 × 3 and 10 × 10 cm{sup 2}. For field sizes down to 1 × 1 cm{sup 2}, the agreement with SRS diode and microliquid filled

  13. SU-E-T-150: Brachytherapy QA Employing a High Resolution Liquid Filled Ionisation Chamber Array: Initial Experience and Limitations

    Energy Technology Data Exchange (ETDEWEB)

    Gainey, M; Kollefrath, M; Bruggmoser, G [University Medical Centre Freiburg, Freiburg Im Breisgau, Baden-Wuerttemberg (Germany)

    2015-06-15

    Purpose: Verifying a complex 3D brachytherapy dose distribution by measurement is non-trivial. Ideally a photon detector array should be independent of energy and angle, have high spatial resolution and be robust for routine clinical use. Methods: An iridium-192 source was used. A PMMA jig was constructed comprising an outer slab and a central insert with eight milled channels for 1.33mm (outer diameter) steel needles, see figure. All calculations were performed using an empty CT study reconstructing eight virtual needles (QA-CT), using the v2 source model (Elekta AG, Sweden). A high resolution liquid filled ionisation chamber array SRS1000, together with Verisoft software v6.0 (PTW Freiburg, Germany), was used to perform measurements of plans of increasing complexity to evaluate its suitability for device- and patient-specific QA. The dimension of backscatter material was investigated. The patient plan dwell time distribution was entered manually into the QA-CT and the dose distribution was calculated. Results: Our measurements indicate that the array is independent of energy and angle. The resulting measured dose values are linearly interpolated to 2025 values. Shifts of 1mm of the entire needle are readily detectable. Individual dwell position shifts (2.5mm) are also readily measurable. Moreover a dwell time increase of 1 second both in the edge and central region are detectable. Conclusion: The high resolution SRS1000 array is a powerful instrument for brachytherapy QA enabling 977 simultaneous measurements to be performed. Our measurements suggest 60mm of RW3 backscatter material upstream and downstream are sufficient. Local percentage difference analysis is useful for device based QA, normalized relative percentage difference is arguably better for patient specific QA. Automated transfer of patient plan dwell time distribution to the QA plan is required to enable a comprehensive patient QA study to be performed. Moreover the described measurement technique

  14. Cosmic ray tests of a 4.6 m-long test drift chamber for JLC

    CERN Document Server

    Kurihara, Y; Sudo, S; Abe, T; Fujii, K; Ishihara, N; Khalatyan, N; Matsui, T; Nitoh, O; Ohama, T; Okuno, H; Sugiyama, A; Takahashi, K; Watanabe, T; Yoshida, T

    2000-01-01

    Performance of a 4.6 m-long drift chamber filled with a CO sub 2 iso-butane (90:10) mixture was studied using cosmic-ray data, in the course of detector R and D for JLC. After correcting the data for wire displacements due to gravitational and electrostatic forces, a spatial resolution of 100 mu m per wire was achieved over the full length of the chamber. The relation between wire efficiency and oxygen remnant in the chamber gas is also discussed.

  15. Efficacy of CM-Wire, M-Wire, and Nickel-Titanium Instruments for Removing Filling Material from Curved Root Canals: A Micro-Computed Tomography Study.

    Science.gov (United States)

    Rodrigues, Clarissa Teles; Duarte, Marco Antonio Hungaro; de Almeida, Marcela Milanezi; de Andrade, Flaviana Bombarda; Bernardineli, Norberti

    2016-11-01

    The aim of this ex vivo study was to evaluate the removal of filling material after using CM-wire, M-wire, and nickel-titanium instruments in both reciprocating and rotary motions in curved canals. Thirty maxillary lateral incisors were divided into 9 groups according to retreatment procedures: Reciproc R25 followed by Mtwo 40/.04 and ProDesign Logic 50/.01 files; ProDesign R 25/.06 followed by ProDesign Logic 40/.05 and ProDesign Logic 50/.01 files; and Gates-Glidden drills, Hedström files, and K-files up to apical size 30 followed by K-file 40 and K-file 50 up to the working length. Micro-computed tomography scans were performed before and after each reinstrumentation procedure to evaluate root canal filling removal. Statistical analysis was performed with Kruskal-Wallis, Friedman, and Wilcoxon tests (P material removal were found in the 3 groups of teeth. The use of Mtwo and ProDesign Logic 40/.05 rotary files did not enhance filling material removal after the use of reciprocating files. The use of ProDesign Logic 50/.01 files significantly reduced the amount of filling material at the apical levels compared with the use of reciprocating files. Association of reciprocating and rotary files was capable of removing a large amount of filling material in the retreatment of curved canals, irrespective of the type of alloy of the instruments. The use of a ProDesign Logic 50/.01 file for apical preparation significantly reduced the amount of remnant material in the apical portion when compared with reciprocating instruments. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. A two-dimensional liquid-filled ionization chamber array prototype for small-field verification: characterization and first clinical tests.

    Science.gov (United States)

    Brualla-González, Luis; Gómez, Faustino; Vicedo, Aurora; González-Castaño, Diego M; Gago-Arias, Araceli; Pazos, Antonio; Zapata, Martín; Roselló, Joan V; Pardo-Montero, Juan

    2012-08-21

    In this work we present the design, characterization and first clinical tests of an in-house developed two-dimensional liquid-filled ionization chamber prototype for the verification of small radiotherapy fields and treatments containing such small fields as in radiosurgery, which consists of 2 mm × 2 mm pixels arranged on a 16×8 rectangular grid. The ionization medium is isooctane. The characterization of the device included the study of depth, field-size and dose-rate dependences, which are sufficiently moderate for a good operation at therapy radiation levels. However, the detector presents an important anisotropic response, up to ≃ 12% for front versus near-lateral incidence, which can impact the verification of full treatments with different incidences. In such a case, an anisotropy correction factor can be applied. Output factors of small square fields measured with the device show a small systematic over-response, less than 1%, when compared to unshielded diode measurements. An IMRT radiosurgery treatment has been acquired with the liquid-filled ionization chamber device and compared with film dosimetry by using the gamma method, showing good agreement: over 99% passing rates for 1.2% and 1.2 mm for an incidence-per-incidence analysis; 100% passing rates for tolerances 1.8% and 1.8 mm when the whole treatment is analysed and the anisotropy correction factor is applied. The point dose verification for each incidence of the treatment performed with the liquid-filled ionization chamber agrees within 1% with a CC01 ionization chamber. This prototype has shown the utility of this kind of technology for the verification of small fields/treatments. Currently, a larger device covering a 5 cm × 5 cm area is under development.

  17. Performance of a position sensitive low-pressure wire chamber (LPWC) having position readout from a separate sense wire plane a critical analysis

    CERN Document Server

    Basu, C; Roy, S; Basu, P; Majumdar, H; Chatterjee, M L

    2002-01-01

    The paper describes the operation of a simple one-dimensional LPWC from a completely different standpoint. The position output is derived from a separate position plane, where discrete resistances are soldered between two adjacent wires. Theoretical formulations for the position extraction are derived where the role of various detector parameters are dealt with. Position spectrum is shown for various choices of resistances varying from 50 OMEGA to 220 k OMEGA. Best position resolution and linearity is obtained for 33 k OMEGA though it violates the existing hypothesis.

  18. spark chamber

    CERN Multimedia

    A few cosmic rays pass through your body every second of every day, no matter where you are. Look at the spark chamber to your right – every flash is the track made by a cosmic ray from outer space. The spark chamber is filled with a special gas mixture. Cosmic rays knock electrons out of the atoms in the gas. These electrons accelerate towards high voltage metal strips layered throughout the chamber, creating sparks like little bolts of lightning.

  19. spark chamber

    CERN Multimedia

    A few cosmic rays pass through your body every second of every day, no matter where you are. Look at the spark chamber to your right – every flash is the track made by a cosmic ray from outer space. The spark chamber is filled with a special gas mixture. Cosmic rays knock electrons out of the atoms in the gas. These electrons accelerate towards high voltage metal strips layered throughout the chamber, creating sparks like little bolts of lightning.

  20. The diastolic function to cyclic variation of myocardial ultrasonic backscatter relation: the influence of parameterized diastolic filling (PDF) formalism determined chamber properties.

    Science.gov (United States)

    Lloyd, Christopher W; Shmuylovich, Leonid; Holland, Mark R; Miller, James G; Kovács, Sándor J

    2011-08-01

    Myocardial tissue characterization represents an extension of currently available echocardiographic imaging. The systematic variation of backscattered energy during the cardiac cycle (the "cyclic variation" of backscatter) has been employed to characterize cardiac function in a wide range of investigations. However, the mechanisms responsible for observed cyclic variation remain incompletely understood. As a step toward determining the features of cardiac structure and function that are responsible for the observed cyclic variation, the present study makes use of a kinematic approach of diastolic function quantitation to identify diastolic function determinants that influence the magnitude and timing of cyclic variation. Echocardiographic measurements of 32 subjects provided data for determination of the cyclic variation of backscatter to diastolic function relation characterized in terms of E-wave determined, kinematic model-based parameters of chamber stiffness, viscosity/relaxation and load. The normalized time delay of cyclic variation appears to be related to the relative viscoelasticity of the chamber and predictive of the kinematic filling dynamics as determined using the parameterized diastolic filling formalism (with r-values ranging from .44 to .59). The magnitude of cyclic variation does not appear to be strongly related to the kinematic parameters.

  1. 硐室式削壁充填采矿法在夹皮沟金矿的应用%Application of resue and fill stoping method with excavating chambers to get filling materials in Jiapigou gold mine

    Institute of Scientific and Technical Information of China (English)

    马杰; 陈国山

    2013-01-01

    上向水平分层削壁充填采矿法以水平分层的形式逐层上采并逐层采削围岩进行充填,工作面可以适应矿体的复杂变化,是回采赋存条件复杂的高价值矿体的有效方法之一.但对于上下盘不稳固的采场,采削围岩会造成片帮冒顶.夹皮沟金矿在应用削壁充填采矿法时,针对不同的矿体赋存条件,特别是上下盘围岩稳固情况,对充填方式和采场采准工程布置参数进行了革新,采用硐室取料的方式进行充填,有效地减小了采幅及采场暴露面积和对两帮围岩的破坏.应用实践取得了较好的技术经济效果.%The upward horizontal slicing resuing-filling method proceeds upwards from one horizontal slice to another and in the mean time back fills with materials cut from wall rocks. The method offers highly adaptable working faces,which makes it an effective way to stope orebodies with high value but complex occurrence conditions. However for the stopes with unstable hanging and lying walls, cutting wall rocks may lead to spalling and roof falling. The application of resuing-filling method in Jiapigou gold mine adapts to different orebody occurrence conditions especially the stability of hanging and lying walls. It updated the fill method and the parameters of pre-mining work, adopted the fill method of excavating chambers to get filling materials and effectively reduced the cutting scale, the exposed area of stopes and damage to wall rocks. The application practice achieved satisfactory technical and economical outcome.

  2. Monitored Drift Chambers in the ATLAS Detector

    CERN Multimedia

    Herten, G

    Monitored Drift Chambers (MDT) are used in the ATLAS Detector to measure the momentum of high energy muons. They consist of drift tubes, which are filled with an Ar-CO2 gas mixture at 3 bar gas pressure. About 1200 drift chambers are required for ATLAS. They are up to 6 m long. Nevertheless the position of every wire needs to be known with a precision of 20 µm within a chamber. In addition, optical alignment sensors are required to measure the relative position of adjacent chambers with a precision of 30µm. This gigantic task seems impossible at first instance. Indeed it took many years of R&D to invent the right tools and methods before the first chamber could be built according to specifications. Today, at the time when 50% of the chambers have been produced, we are confident that the goal for ATLAS can be reached. The mechanical precision of the chambers could be verified with the x-ray tomograph at CERN. This ingenious device, developed for the MDT system, is able to measure the wire position insid...

  3. Detecting management and fertilization effects on the carbon balance of winter oilseed rape with manual closed chamber measurements: Can we outrange gap-filling uncertainty and spatiotemporal variability?

    Science.gov (United States)

    Huth, Vytas; Moffat, Antje Maria; Calmet, Anna; Andres, Monique; Laufer, Judit; Pehle, Natalia; Rach, Bernd; Gundlach, Laura; Augustin, Jürgen

    2017-04-01

    Winter oilseed rape is the dominant biofuel crop in the young moraine landscape in North-Eastern Germany. However, studies on the effect of rapeseed cropping on net ecosystem exchange of CO2 (NEE) and the soil carbon (SC) balance are scarce. SC balance estimates are usually derived from long-term soil sampling field trials where rapeseed is part of different crop rotations. The estimated annual differences linked to rapeseed cropping are rather small (varying between losses of 40 g C m-2 and gains of up to 100 g C m-2). Testing management effects on the NEE and SC balance of cropping systems is best done by comparing plots with different treatments at the same site under the same climate. The soil sampling approach is in the need of field trials that run over decades, which has the disadvantage that management strategies of practical farming may have already changed when the results are derived. Continuous eddy covariance measurements of NEE would require large fields in flat terrain for each of the treatments, which is especially complicated in the heterogeneous landscapes of glacigenic origin of North-Eastern Germany. The common approach of using the chamber technique to derive NEE, however, is subject to the local soil and plant stand heterogeneities due to its tiny footprint. This technique might also disturb the ecosystem, the measurements are usually discontinuous requiring elaborate gap-filling techniques, and it has mostly been used on organic soils where large respiratory C losses occur. Therefore, our aim was to answer, if a combined approach of the eddy covariance and the chamber technique can detect the relatively small NEE and SC differences of rapeseed cropping on mineral soils within a shorter period of time than conventional soil sampling field trials can. We tested the new experimental design taking the advantages of both techniques into account: The eddy covariance tower measuring the NEE dynamics during the year; the chamber measurements to

  4. Contemplation of thermal characteristics by filling ratio of Al2O3 nanofluid in wire mesh heat pipe

    Directory of Open Access Journals (Sweden)

    R. Senthil

    2016-06-01

    Full Text Available An experimental investigation on the thermal efficiency and thermal resistance with respect to the inclined angle using heat pipe was carried out. The working fluids used for this are Al2O3 nanofluid and deionized water. The performance of heat pipe in terms of overall heat transfer coefficient and thermal resistance is quantified by varying the volume of working fluid and the performance parameters are contemplated. For this purpose Al2O3 nanoparticles with a density of 9.8 g/cm3 and a volume concentration of 1% are used as the working fluid in experimental heat pipe. The performance of heat pipe was evaluated by conducting experiments with different thermal loads and different angle of inclinations. Thermocouples are used to record the temperature distribution across the experiment. Volume of nanoparticles in the base fluid and the consequence of filling ratio on the thermal resistance of the nanofluids are investigated. The results provide evidence that the suspension of Al2O3 nanoparticles in the base fluid increases the thermal efficiency of heat pipe and can be used in practical heat exchange applications.

  5. Prototype multiwire proportional chamber

    CERN Multimedia

    1975-01-01

    Chambers of this type were initially developed within the Alpha project (finally not approved). They were designed such to minimize the radiation length with a view to a mass spectrometer of high resolution meant to replace the Omega detector. The chambers were clearly forerunners for the (drift) chambers later built for R606 with the novel technique of crimping the wires. See also photo 7510039X.

  6. Divergent NEE balances from manual-chamber CO2 fluxes linked to different measurement and gap-filling strategies: A source for uncertainty of estimated terrestrial C sources and sinks?

    DEFF Research Database (Denmark)

    Huth, Vytas; Vaidya, Shrijana; Hoffmann, Mathias

    2017-01-01

    Manual closed-chamber measurements are commonly used to quantify annual net CO2 ecosystem exchange (NEE) in a wide range of terrestrial ecosystems. However, differences in both the acquisition and gap filling of manual closed-chamber data are large in the existing literature, complicating inter......-study comparisons and meta analyses. The aim of this study was to compare common approaches for quantifying CO2 exchange at three methodological levels. (1) The first level included two different CO2 flux measurement methods: one via measurements during mid-day applying net coverages (mid-day approach) and one via...... of the agricultural field diverged strongly (–200 to 425 g CO2-C m−2). NEE balances were most similar to previous studies when derived from sunrise measurements and indirect GPP modeling. Overall, the large variation in NEE balances resulting from different data-acquisition or gap-filling strategies indicates...

  7. The GODDESS ionization chamber: developing robust windows

    Science.gov (United States)

    Blanchard, Rose; Baugher, Travis; Cizewski, Jolie; Pain, Steven; Ratkiewicz, Andrew; Goddess Collaboration

    2015-10-01

    Reaction studies of nuclei far from stability require high-efficiency arrays of detectors and the ability to identify beam-like particles, especially when the beam is a cocktail beam. The Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies (GODDESS) is made up of the Oak Ridge-Rutgers University Barrel Array (ORRUBA) of silicon detectors for charged particles inside of the gamma-ray detector array Gammasphere. A high-rate ionization chamber is being developed to identify beam-like particles. Consisting of twenty-one alternating anode and cathode grids, the ionization chamber sits downstream of the target chamber and is used to measure the energy loss of recoiling ions. A critical component of the system is a thin and robust mylar window which serves to separate the gas-filled ionization chamber from the vacuum of the target chamber with minimal energy loss. After construction, windows were tested to assure that they would not break below the required pressure, causing harm to the wire grids. This presentation will summarize the status of the ionization chamber and the results of the first tests with beams. This work is supported in part by the U.S. Department of Energy and National Science Foundation.

  8. Production and test of the LHCb Muon Chamber

    CERN Multimedia

    2005-01-01

    - The Muon System of LHCb - The Multi-Wire Proportional Chambers for LHCb - Wire tension meter - Wire pitch measurement - Gas leakage test - Test with cosmic rays - Production and test summary - Gap gain uniformity - Production and test summary

  9. DELPHI Barrel Muon Chamber Module

    CERN Multimedia

    1989-01-01

    The module was used as part of the muon identification system on the barrel of the DELPHI detector at LEP, and was in active use from 1989 to 2000. The module consists of 7 individual muons chambers arranged in 2 layers. Chambers in the upper layer are staggered by half a chamber width with respect to the lower layer. Each individual chamber is a drift chamber consisting of an anode wire, 47 microns in diameter, and a wrapped copper delay line. Each chamber provided 3 signal for each muon passing through the chamber, from which a 3D space-point could be reconstructed.

  10. Making MUSIC: A multiple sampling ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Shumard, B. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)]. E-mail: shumard@phy.anl.gov; Henderson, D.J. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Rehm, K.E. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Tang, X.D. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)

    2007-08-15

    A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the ({alpha}, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for ({alpha}, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only ({alpha}, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. x 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the ({alpha}, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the ({alpha}, p) reaction to reach the anode segment below the reaction.

  11. Laboratory aging studies for the HERA-B muon chambers

    CERN Document Server

    Danilov, M; Titov, M; Zaitsev, Y

    2002-01-01

    The severe radiation environment of the HERA-B experiment leads to a maximum accumulated charge on a wire, within the muon detector, of 200 mC/cm wire. For operation in this high-intensity environment, the main criteria for the gas choice turned out to be stability against aging. We report recent results of laboratory aging studies performed by irradiating proportional wire chambers filled with Ar/CF sub 4 /CH sub 4 (74:20:6), Ar/CF sub 4 /CH sub 4 (67:30:3), and Ar/CF sub 4 /CO sub 2 (65:30:5) mixtures. The penetration of water and oxygen through the walls of plastic tubes has also been investigated. Water can be introduced indirect to the gas mixture by using polyamide (nylon) pipes for gas supply lines.

  12. The extreme wave interaction with the constructions of the breakwaters including the damping chamber that was filled up with the stones and concrete units

    Science.gov (United States)

    Maximov, Vasily; Nudner, Igor; Revyakin, Alexei

    2010-05-01

    The eight types of the breakwaters constructions including the damping chamber were experimentally studied. The damping chamber has the infilling with the stones, with the concrete units, or with the combinations of the stones and units. The back wall of the damping chamber was impermeable. The construction varies by the volume and by the type of the infilling. The experiments to specify the pressure at the internal walls of the damping chamber, the reflected wave height, and the wave height at the front wall were performed at the hydro flume. This flume has the following dimensions: 43 m length, 0.7 m width, and 1.2 m height. The periodic waves were produced by the shield-type wavemaker. We vary in this research the periods of the waves over the range 0.8 s to 1.64 s, and the wave height over the range 10 cm to 24 cm. The analysis revealed the most improved structure possessing the good wave-protective features.

  13. Simulating thermo-mechanical interaction between a xenon gas-filled chamber and tungsten first-wall armor for the LIFE reactor design using the BUCKY 1-D radiation hydrodynamics code

    Energy Technology Data Exchange (ETDEWEB)

    Heltemes, T A; Prochaska, A E; Moses, G A, E-mail: taheltemes@wisc.ed [Fusion Technology Institute, University of Wisconsin - Madison, 1500 Engineering Dr., Madison WI 53706 (United States)

    2010-08-01

    The BUCKY 1-D radiation hydrodynamics code has been used to simulate the dynamic thermo-mechanical interaction between a xenon gas-filled chamber and tungsten first-wall armor with an indirect-drive laser fusion target for the LIFE reactor design. Two classes of simulations were performed: (1) short-time (0-2 ms) simulations to fully capture the hydrodynamic effects of the introduction of the LIFE indirect-drive target x-ray and ion threat spectra and (2) long-time (2-70 ms) simulations starting with quiescent chamber conditions characteristic of those at 2 ms to estimate xenon plasma cooling between target implosions at 13 Hz. The short-time simulation results reported are: (1) the plasma hydrodynamics of the xenon in the chamber, (2) dynamic overpressure on the tungsten armor, and (3) time-dependent temperatures in the tungsten armor. The ramifications of local thermodynamic equilibrium (LTE) vs. non-LTE opacity models are also addressed.

  14. Study of high-pressure hydrogen-operated wire chambers designed for a precision measurement of the singlet mu p capture rate

    CERN Document Server

    Maev, E M; Case, T A; Crowe, K M; Dick, P U; Dijksman, A; Egger, J; Fetisov, A A; Ganzha, V A; Herold, W D; Hartmann, F J; Kammel, P; Krivchitch, A G; Maev, O E; Petitjean, C; Petrov, G E; Prieels, R; Sadetsky, S M; Schapkin, G N; Schmidt, R; Semenchuk, G G; Soroka, M; Vorobyov, A A; Voropaev, N I

    2002-01-01

    This work was carried out as part of a project aiming at a greatly improved measurement of the muon capture rate from the singlet state of the mu p atom. The experiment will be performed at the intense muon beam of PSI using a new experimental method allowing high precision measurements of the lifetime of muons stopped in ultra-pure deuterium-depleted hydrogen (protium). The basic element of the detector is a time projection chamber operating in hydrogen gas at 10 bar pressure. The arrival times and trajectories of the incoming muons and the outgoing decay electrons are measured with this device providing effective suppression of background. The system of chambers and electronics is designed for the large muon stop rates required for attaining high statistical accuracy. During four beam periods at PSI, data were taken. Also, various studies of the MWPC performance in hydrogen were made including ageing studies of the chambers under irradiation with stopped muons and with alpha and beta sources. It was demonst...

  15. The Design of High Pressure Filling Xe Ionization Chamber and Electric Field Simulation%高气压充 Xe 电离室的设计与电场模拟

    Institute of Scientific and Technical Information of China (English)

    付睿玺; 曾国强; 葛良全

    2015-01-01

    设计了一种阳极为平板型的高压充Xe共栅阳极电离室。根据电离室Xe气的压强与施加电场关系,确定最佳气体密度和电场强度。在理论上推导与分析的基础上,获得电离室输出信号和电场分布的关系,从而对探测器结构进行优化设计。通过ansoftmaxwell 12模拟电场实验,采用加入保护环、施加不同阴极和收集极电压的方法对电场等势线分布进行优化,改善电荷收集区和非电荷收集区分布,提高了电离室的能量分辨率。%This paper presents a high -voltage Xe filling grid anode ionization chamber which the anodes are flat type.The best of the gas density and the electric field strength is determined by comparing the pressure of Xe gas and the applied electric field .Through theoretical derivation and analysis the signal mechanism of the ioni -zation chamber using coplanar grid anode technology is obtained , getting the relationship between electric field distribution and the output signal of ionization chamber , so as to optimize the structure of the detector .Ansoft-maxwell 12 is used to simulate the electric field in the experiments .By adding a guard ring and applying differ-ent anode and cathode voltage to optimizing the equipotential lines , it plays the role of improving charge and non-charge collection region and improves the energy resolution of the Ionization chamber .

  16. Physicist makes muon chamber sing

    CERN Document Server

    2007-01-01

    This Monitored Drift Tube detector, consisting of argon-CO2-filled aluminium tubes with a wire down the centre of each, will track muons in ATLAS; Tiecke used a single tube from one of these detectors to create the pipes in his organ. Particle physicists can make good musicians; but did you know particle detectors can make good music? That's what NIKHEF physicist Henk Tiecke learned when he used pipes cut from the ATLAS Monitored Drift Tube detector (MDT) to build his own working Dutch-style barrel organ in the autumn of 2005. 'I like to work with my hands,' said Tiecke, who worked as a senior physicist at NIKHEF, Amsterdam, on ZEUS until his retirement last summer. Tiecke had already constructed his barrel organ when he visited some colleagues in the ATLAS muon chambers production area at Nikhef in 2005. He noticed that the aluminium tubes they were using to build the chambers were about three centimetres in diameter-just the right size for a pipe in a barrel organ. 'The sound is not as nice as from wooden...

  17. Clinical comparison between HeartMate VE auto-mode and HeartMate XVE auto-mode with Opti-Fill and the effect of stroke volume on blood chamber and inflow valve peak pressures.

    Science.gov (United States)

    Rodermans, Ben F M; Lahpor, Jaap R; van Schelven, Leonard J; Nieuwenhuis, Esther; Sukkel, Eveline Y; van Schouwen-van Kranen, Else

    2007-01-01

    We determined the difference between HeartMate (HM) VE auto mode, average filling 76 mL, and HM XVE Opti-Fill, average filling 79 mL, regarding blood chamber and inflow valve peak pressure pulses (BCPP and IVPP). The relation between stroke volume (SV) and peak pressures was investigated by using a circulatory mock loop. At high SVs, 79 to 83 mL, BCPP and IVPP never exceeded 400 mm Hg. For lower SVs, down to 50 mL, the peak pressures increased to 788 mm Hg for BCPP and 416 mm Hg for IVPP. Distribution of SV was measured in 2 VE and 6 XVE patients during rest and activities of daily living (ADL). For clinical comparison, percentages of SV >78 mL were determined. At rest, 2190 (VE) and 5772 (XVE) pump beats were registered and 4511 (VE) and 8713 (XVE) during ADL. Percentages of "SV >78 mL" at rest, respectively, were 42.5 +/- 3.5 and 78.2 +/- 4.7 (p 78 mL and makes an important contribution to reducing the incidence of high peak pressures in the clinical setting.

  18. Anode wire aging tests with selected gases

    Energy Technology Data Exchange (ETDEWEB)

    Kadyk, J.; Wise, J.; Hess, D.; Williams, M. (Lawrence Berkeley Lab., CA (United States))

    1990-04-01

    As a continuation of earlier wire aging investigations, additional candidates for wire chamber gas and wire have been tested. These include the gases: argon/ethane, HRS gas, dimethyl ether, carbon dioxide/ethane, and carbon tetrafluoride/isobutane. Wires used were: gold- plated tungsten, Stablohm, Nicotin, and Stainless Steel. Measurements were made of the effects upon wire aging of impurities from plumbing materials or contamination from various types of oil. Attempts were made to induce wire aging by adding measured amounts of oxygen and halogen (methyl chloride) with negative results. In this paper, the possible role of electronegativity in the wire aging process is discussed, and measurements of electronegativity are made with several single carbon Freons, using both an electron capture detector and a wire chamber operating with dimethyl ether.

  19. Geology and preliminary dating of the hominid-bearing sedimentary fill of the Sima de los Huesos Chamber, Cueva Mayor of the Sierra de Atapuerca, Burgos, Spain.

    Science.gov (United States)

    Bischoff, J L; Fitzpatrick, J A; León, L; Arsuagà, J L; Falgueres, C; Bahain, J J; Bullen, T

    1997-01-01

    Sediments of the Sima de los Huesos vary greatly over distances of a few meters. This is typical of interior cave facies, and caused by cycles of cut and fill. Mud breccias containing human bones, grading upwards to mud containing bear bones, fill an irregular surface cut into basal marks and sands. The lack of Bedding and the chaotic abundance of fragile speleothem clasts in the fossiliferous muds suggests that the deposit was originally a subterranean pond facies, and that after emplacement of the human remains, underwent vigorous post-depositional rotation and collapse and brecciation, caused by underlying bedrock dissolution and undermining. The fossiliferous deposits are capped by flowstone and guano-bearing muds which lack large-mammal fossils. U-series and radiocarbon dating indicates the capping flowstones formed from about 68 ka to about 25 ka. U-series analyses of speleothem clasts among the human fossils indicate that all are at, or close to, isotopic equilibrium (> 350 ka). The distribution of U-series dates for 25 bear bones (154 +/- 66 ka) and for 16 human bones (148 +/- 34 ka) is similar and rather broad. Because the human bones seem to be stratigraphically older than chose of the bears, the results would indicate that most of the bones have been accumulating uranium irregularly with time. Electron spin resonance (ESR) analyses of six selected bear bones indicates dates of 189 +/- 28 ka, for which each is cordant with their corresponding U-series date (181 +/- 41 ka). Combined ESR and U-series dates for these samples yielded 200 +/- 4 ka. Such agreement is highly suggestive that uranium uptake in these bones was close to the early-uptake (EU) model, and the dates are essentially correct. Another three selected samples yielded combined ESR U-series dates of 320 +/- 4 ka with a modeled intermediate-mode of uranium uptake. The dating results, therefore, seem to provide a firm minimum age of about 200 ka for the human entry: and suggestive evidence of

  20. The CLEO III drift chamber

    CERN Document Server

    Peterson, D; Briere, R A; Chen, G; Cronin-Hennessy, D; Csorna, S; Dickson, M; Dombrowski, S V; Ecklund, K M; Lyon, A; Marka, S; Meyer, T O; Patterson, J R; Sadoff, A; Thies, P; Thorndike, E H; Urner, D

    2002-01-01

    The CLEO group at the Cornell Electron Storage Ring has constructed and commissioned a new central drift chamber. With 9796 cells arranged in 47 layers ranging in radius from 13.2 to 79 cm, the new drift chamber has a smaller outer radius and fewer wires than the drift chamber it replaces, but allows the CLEO tracking system to have improved momentum resolution. Reduced scattering material in the chamber gas and in the inner skin separating the drift chamber from the silicon vertex detector provides a reduction of the multiple scattering component of the momentum resolution and an extension of the usable measurement length into the silicon. Momentum resolution is further improved through quality control in wire positioning and symmetry of the electric fields in the drift cells which have provided a reduction in the spatial resolution to 88 mu m (averaged over the full drift range).

  1. High rate drift chambers

    Energy Technology Data Exchange (ETDEWEB)

    Christian, D.C. (Fermilab, Batavia, IL 60510 (United States)); Berisso, M.C. (Fermilab, Batavia, IL 60510 (United States)); Gutierrez, G. (Fermilab, Batavia, IL 60510 (United States)); Holmes, S.D. (Fermilab, Batavia, IL 60510 (United States)); Wehmann, A. (Fermilab, Batavia, IL 60510 (United States)); Avilez, C. (Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico)); Felix, J. (Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico)); Moreno, G. (Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico)); Romero, M. (Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico)); Sosa, M. (Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato (Mexico)); Forbush, M. (Department of Physics, Texas A and M University, College Station, TX 77843 (United States)); Huson, F.R. (Department of Physics, Texas A and M University, College Station, TX 77843 (United States)); Wightman, J.A. (Department of Physi

    1994-06-01

    Fermilab experiment 690, a study of target dissociation reactions pp[yields]pX using an 800 GeV/c proton beam and a liquid hydrogen target, collected data in late 1991. The incident beam and 600-800 GeV/c scattered protons were measured using a system of six 6 in.x4 in. and two 15 in.x8 in. pressurized drift chambers spaced over 260 m. These chambers provided precise measurements at rates above 10 MHz (2 MHz per cm of sense wire). The measurement resolution of the smaller chambers was 90 [mu]m, and the resolution of the larger chambers was 125 [mu]m. Construction details and performance results, including radiation damage, are presented. ((orig.))

  2. Demonstration/Validation of the TC-60 Controlled Detonation Chamber, Porton Down, UK: Final Demonstration Test Report

    Science.gov (United States)

    2007-06-01

    chamber junction box, was diagnosed the following day (3 March, a scheduled maintenance day). The wire was reattached to the terminal strip, restoring...destroyed in the threshold system: (a) Chemical agents: Blister agent (mustard), Nonpersistent nerve agent (GB) and Industrial chemical (phosgene) (b) In...addition to the munitions fill material listed above; the systems objective capability is to destroy: Chemical agents: Lewisite, Persistent nerve agent

  3. The KLOE drift chamber

    Energy Technology Data Exchange (ETDEWEB)

    Adinolfi, M.; Aloisio, A.; Ambrosino, F.; Andryakov, A.; Antonelli, A.; Antonelli, M.; Anulli, F.; Bacci, C.; Bankamp, A.; Barbiellini, G.; Bellini, F.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocci, V.; Bossi, F.; Branchini, P.; Bulychjov, S.A.; Cabibbo, G.; Calcaterra, A.; Caloi, R.; Campana, P.; Capon, G.; Carboni, G.; Cardini, A.; Casarsa, M.; Cataldi, G.; Ceradini, F.; Cervelli, F.; Cevenini, F.; Chiefari, G.; Ciambrone, P.; Conetti, S.; Conticelli, S.; Lucia, E. De; Robertis, G. De; Sangro, R. De; Simone, P. De; Zorzi, G. De; Dell' Agnello, S.; Denig, A.; Domenico, A. Di; Donato, C. Di; Falco, S. Di; Doria, A.; Drago, E.; Elia, V.; Erriquez, O.; Farilla, A.; Felici, G.; Ferrari, A.; Ferrer, M.L.; Finocchiaro, G.; Forti, C.; Franceschi, A.; Franzini, P.; Gao, M.L.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Golovatyuk, V.; Gorini, E.; Grancagnolo, F.; Grandegger, W.; Graziani, E.; Guarnaccia, P.; Hagel, U.V.; Han, H.G.; Han, S.W.; Huang, X.; Incagli, M.; Ingrosso, L.; Jang, Y.Y.; Kim, W.; Kluge, W.; Kulikov, V.; Lacava, F.; Lanfranchi, G.; Lee-Franzini, J.; Lomtadze, F.; Luisi, C.; Mao, C.S.; Martemianov, M.; Matsyuk, M.; Mei, W.; Merola, L.; Messi, R.; Miscetti, S.; Moalem, A.; Moccia, S.; Moulson, M.; Mueller, S.; Murtas, F.; Napolitano, M.; Nedosekin, A.; Panareo, M.; Pacciani, L.; Pages, P.; Palutan, M.; Paoluzi, L.; Pasqualucci, E.; Passalacqua, L.; Passaseo, M.; Passeri, A.; Patera, V.; Petrolo, E.; Petrucci, G.; Picca, D.; Pirozzi, G.; Pistillo, C.; Pollack, M.; Pontecorvo, L.; Primavera, M.; Ruggieri, F.; Santangelo, P.; Santovetti, E.; Saracino, G.; Schamberger, R.D.; Schwick, C.; Sciascia, B.; Sciubba, A.; Scuri, F.; Sfiligoi, I.; Shan, J.; Silano, P.; Spadaro, T.; Spagnolo, S.; Spiriti, E.; Stanescu, C.; Tong, G.L.; Tortora, L.; Valente, E.; Valente, P. E-mail: paolo.valente@lnf.infn.it; Valeriani, B.; Venanzoni, G.; Veneziano, S.; Wu, Y.; Xie, Y.G.; Zhao, P.P.; Zhou, Y

    2001-04-01

    The tracking detector of the KLOE experiment is 4 m diameter, 3.3 m length drift chamber, designed to contain a large fraction of the decays of low-energy K{sub L} produced at the Frascati DAPHINE phi-factory. The chamber is made by a thin carbon fiber structure and operated with a helium-based gas mixture in order to minimise conversion of low-energy photons and multiple scattering inside the sensitive volume. The tracking information is provided by 58 layers of stereo wires defing 12,582 cells, 2x2 cm{sup 2} in size in the 12 innermost layers and 3x3 cm{sup 2} in the outer ones. Details of the chamber design, calibration procedure and tracking performances are presented.

  4. The KLOE drift chamber

    CERN Document Server

    Adinolfi, M; Ambrosino, F; Andryakov, A; Antonelli, A; Antonelli, M; Anulli, F; Bacci, C; Bankamp, A; Barbiellini, G; Bellini, F; Bencivenni, G; Bertolucci, Sergio; Bini, C; Bloise, C; Bocci, V; Bossi, F; Branchini, P; Bulychjov, S A; Cabibbo, G; Calcaterra, A; Caloi, R; Campana, P; Capon, G; Carboni, G; Cardini, A; Casarsa, M; Cataldi, G; Ceradini, F; Cervelli, F; Cevenini, F; Chiefari, G; Ciambrone, P; Conetti, S; Conticelli, S; Lucia, E D; Robertis, G D; Sangro, R D; Simone, P D; Zorzi, G D; Dell'Agnello, S; Denig, A; Domenico, A D; Donato, C D; Falco, S D; Doria, A; Drago, E; Elia, V; Erriquez, O; Farilla, A; Felici, G; Ferrari, A; Ferrer, M L; Finocchiaro, G; Forti, C; Franceschi, A; Franzini, P; Gao, M L; Gatti, C; Gauzzi, P; Giovannella, S; Golovatyuk, V; Gorini, E; Grancagnolo, F; Grandegger, W; Graziani, E; Guarnaccia, P; Von Hagel, U; Han, H G; Han, S W; Huang, X; Incagli, M; Ingrosso, L; Jang, Y Y; Kim, W; Kluge, W; Kulikov, V; Lacava, F; Lanfranchi, G; Lee-Franzini, J; Lomtadze, F; Luisi, C; Mao Chen Sheng; Martemyanov, M; Matsyuk, M; Mei, W; Merola, L; Messi, R; Miscetti, S; Moalem, A; Moccia, S; Moulson, M; Müller, S; Murtas, F; Napolitano, M; Nedosekin, A; Panareo, M; Pacciani, L; Pagès, P; Palutan, M; Paoluzi, L; Pasqualucci, E; Passalacqua, L; Passaseo, M; Passeri, A; Patera, V; Petrolo, E; Petrucci, Guido; Picca, D; Pirozzi, G; Pistillo, C; Pollack, M; Pontecorvo, L; Primavera, M; Ruggieri, F; Santangelo, P; Santovetti, E; Saracino, G; Schamberger, R D; Schwick, C; Sciascia, B; Sciubba, A; Scuri, F; Sfiligoi, I; Shan, J; Silano, P; Spadaro, T; Spagnolo, S; Spiriti, E; Stanescu, C; Tong, G L; Tortora, L; Valente, E; Valente, P; Valeriani, B; Venanzoni, G; Veneziano, Stefano; Wu, Y; Xie, Y G; Zhao, P P; Zhou, Y

    2001-01-01

    The tracking detector of the KLOE experiment is 4 m diameter, 3.3 m length drift chamber, designed to contain a large fraction of the decays of low-energy K sub L produced at the Frascati DAPHINE phi-factory. The chamber is made by a thin carbon fiber structure and operated with a helium-based gas mixture in order to minimise conversion of low-energy photons and multiple scattering inside the sensitive volume. The tracking information is provided by 58 layers of stereo wires defing 12,582 cells, 2x2 cm sup 2 in size in the 12 innermost layers and 3x3 cm sup 2 in the outer ones. Details of the chamber design, calibration procedure and tracking performances are presented.

  5. Cavitation during wire brushing

    Science.gov (United States)

    Li, Bo; Zou, Jun; Ji, Chen

    2016-11-01

    In our daily life, brush is often used to scrub the surface of objects, for example, teeth, pots, shoes, pool, etc. And cleaning rust and stripping paint are accomplished using wire brush. Wire brushes also can be used to clean the teeth for large animals, such as horses, crocodiles. By observing brushing process in water, we capture the cavitation phenomenon on the track of moving brush wire. It shows that the cavitation also can affect the surface. In order to take clear and entire pictures of cavity, a simplified model of one stainless steel wire brushing a boss is adopted in our experiment. A transparent organic tank filled with deionized water is used as a view box. And a high speed video camera is used to record the sequences. In experiment, ambient pressure is atmospheric pressure and deionized water temperature is kept at home temperature. An obvious beautiful flabellate cavity zone appears behind the moving steel wire. The fluctuation of pressure near cavity is recorded by a hydrophone. More movies and pictures are used to show the behaviors of cavitation bubble following a restoring wire. Beautiful tracking cavitation bubble cluster is captured and recorded to show.

  6. Beam Profiling through Wire Chambing Tracking

    CERN Document Server

    Nash, W

    2013-01-01

    This note describes the calibration of the Delay Wire Chambers (DWCs) used during test runs of CALICE’s Tungsten Digital Hadron Calorimeter (W-DHCAL) prototype in CERN’s SPS beam line (10 – 300 GeV).

  7. Ion chamber based neutron detectors

    Science.gov (United States)

    Derzon, Mark S; Galambos, Paul C; Renzi, Ronald F

    2014-12-16

    A neutron detector with monolithically integrated readout circuitry, including: a bonded semiconductor die; an ion chamber formed in the bonded semiconductor die; a first electrode and a second electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; and the readout circuitry which is electrically coupled to the first and second electrodes. The bonded semiconductor die includes an etched semiconductor substrate bonded to an active semiconductor substrate. The readout circuitry is formed in a portion of the active semiconductor substrate. The ion chamber has a substantially planar first surface on which the first electrode is formed and a substantially planar second surface, parallel to the first surface, on which the second electrode is formed. The distance between the first electrode and the second electrode may be equal to or less than the 50% attenuation length for neutrons in the neutron absorbing material filling the ion chamber.

  8. micro strip gas chamber

    CERN Multimedia

    1998-01-01

    About 16 000 Micro Strip Gas Chambers like this one will be used in the CMS tracking detector. They will measure the tracks of charged particles to a hundredth of a millimetre precision in the region near the collision point where the density of particles is very high. Each chamber is filled with a gas mixture of argon and dimethyl ether. Charged particles passing through ionise the gas, knocking out electrons which are collected on the aluminium strips visible under the microscope. Such detectors are being used in radiography. They give higher resolution imaging and reduce the required dose of radiation.

  9. Laser Non-Uniform Heating of Moving Thin Wires Below the Biot Number Criterion of Uniform Temperature

    Science.gov (United States)

    Wickramasooriya, Thiwanka; Vaidyanathan, Raj; Kar, Aravinda

    2016-06-01

    An analytic solution is obtained for three-dimensional quasi-steady state temperature distribution during laser heating of moving thin wires. The wire moves at a constant speed through a vacuum chamber, which is back-filled with an inert gas such as argon, and a laser beam of rectangular cross-section is incident on the wire. The ambient gas provides a convection heat transfer mechanism, which yields a Biot number, Bi, for the heating process to determine whether the temperature distribution would be uniform or nonuniform in the cross-section of the wire. Generally, the criterion of Bi less than 0.1 is applied to assume spatially uniform temperature distribution in a solid. The temperature distribution is determined for different Bi numbers and the variation of the temperature in the azimuthal direction is analyzed. The method of solution involves the Fourier transform in the azimuthal direction and the Hankel transform in the radial direction for a three-dimensional quasi-steady state heat conduction equation containing an advection term that accounts for the motion of the wire. The thermal and optical properties of the material is assumed to be constant in the temperature range of this study. The heat loss due to radiation heat transfer between the wire surface and the surrounding environment is neglected due to the small laser-heated surface area. Using this model, the temperature profile is studied for different process parameters such as the incident laser power, laser beam profile, Biot number, and wire speed.

  10. Recent developments of multiwire proportional chambers at JINR (DUBNA)

    CERN Document Server

    Filippov, A I

    1980-01-01

    In this report a review of some wire chamber developments at JINR is given. The conception and performance of different detectors will be discussed as well as their application in experiments. For NA-4 (CERN) a special proportional chamber with asymmetric cut for the target was built. The necessary rigidness was achieved by sandwich panels with honeycomb filling. In order to study rare processes with registration of the nuclear fragments a proportional drift chamber was constructed. The resolution for Delta m was 0.2 GeV and 0.2 for Delta Z. In the Laboratory of Nuclear Problems a new mode of gas amplification was investigated. It was shown to have interesting characteristics from the practical point of view; apparently it cannot be interpreted as a transitory mode. On the basis of these investigations two large systems of drift chambers operating in the selfquenching mode have been made. For investigations on the synchrocyclotron a multipurpose magnetic spectrometer ARES (Analyser of Rate Events) was develop...

  11. Physicist makes muon chamber sing

    CERN Multimedia

    2007-01-01

    1. This Monitored Drift Tube detector, consisting of argon-CO2-filled aluminium tubes with a wire down the centre of each, will track muons in ATLAS; Tiecke used a single tube from one of these detectors to create the pipes in his organ.

  12. Plasto-hydrodynamic polymer coating of fine wires

    OpenAIRE

    Lamb, Roger E.

    1989-01-01

    This project outlines the design and commissioning of a multi-purpose drawing bench and pressure die chamber so as to coat fine wires. The pressure chamber was designed along similar lines to the pressure chambers used by previous researchers for Plasto-hydrodynamic die-less drawing of wire. The commissioning and future safe operation of the drawing bench have been described. The experimental proceedures and methods have been outlined. Investigations into a wide ra...

  13. Heat-transfer regularities of the anemometric wire

    Science.gov (United States)

    Mikheev, N. I.; Sakhovsky, A. V.; Khairnasov, K. R.; Kratirov, D. V.

    2010-06-01

    Experimental heat-transfer data for a small-diameter hot wire have been obtained and generalized in a wide range of Reynolds numbers typical of hot-wire anemometry. The experiments were carried out using an IRVIS-TA5 digital hot-wire anemometer and standard critical nozzles used for regulating the flow in the test section of the Eiffel chamber in which the hot-wire sensor was installed. Approaches to carrying out hot-wire anemometric measurements without a labor-consuming calibration procedure for the hot-wire sensor are substantiated.

  14. The Mark II Vertex Drift Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, J.P.; Baggs, R.; Fujino, D.; Hayes, K.; Hoard, C.; Hower, N.; Hutchinson, D.; Jaros, J.A.; Koetke, D.; Kowalski, L.A.

    1989-03-01

    We have completed constructing and begun operating the Mark II Drift Chamber Vertex Detector. The chamber, based on a modified jet cell design, achieves 30 {mu}m spatial resolution and <1000 {mu}m track-pair resolution in pressurized CO{sub 2} gas mixtures. Special emphasis has been placed on controlling systematic errors including the use of novel construction techniques which permit accurate wire placement. Chamber performance has been studied with cosmic ray tracks collected with the chamber located both inside and outside the Mark II. Results on spatial resolution, average pulse shape, and some properties of CO{sub 2} mixtures are presented. 10 refs., 12 figs., 1 tab.

  15. Wireless transmission of biosignals for hyperbaric chamber applications

    OpenAIRE

    Perez-Vidal, Carlos; Gracia, Luis; Carmona, Cristian; Alorda, Bartomeu; Salinas, Antonio

    2017-01-01

    This paper presents a wireless system to send biosignals outside a hyperbaric chamber avoiding wires going through the chamber walls. Hyperbaric chambers are becoming more and more common due to new indications of hyperbaric oxygen treatments. Metallic walls physically isolate patients inside the chamber, where getting a patient?s vital signs turns into a painstaking task. The paper proposes using a ZigBee-based network to wirelessly transmit the patient's biosignals to the outside of the cha...

  16. Large-Scale Production of Monitored Drift Tube Chambers for the ATLAS Muon Spectrometer

    CERN Document Server

    Bauer, F; Kortner, O; Kroha, H; Manz, A; Mohrdieck, S; Richter, R; Zhuravlov, V

    2016-01-01

    Precision drift tube chambers with a sense wire positioning accuracy of better than 20 microns are under construction for the ATLAS muon spectrometer. 70% of the 88 large chambers for the outermost layer of the central part of the spectrometer have been assembled. Measurements during chamber construction of the positions of the sense wires and of the sensors for the optical alignment monitoring system demonstrate that the requirements for the mechanical precision of the chambers are fulfilled.

  17. Ultra-low mass drift chambers

    Energy Technology Data Exchange (ETDEWEB)

    Assiro, R. [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Cappelli, L. [Università di Cassino e del Lazio Meridionale (Italy); Cascella, M. [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Dipartimento Matematica e Fisica, Università del Salento (Italy); De Lorenzis, L. [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Dipartimento di Ingegneria dell' Innovazione, Università del Salento (Italy); Grancagnolo, F. [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Ignatov, F. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); L' Erario, A.; Maffezzoli, A. [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Dipartimento di Ingegneria dell' Innovazione, Università del Salento (Italy); Miccoli, A. [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Onorato, G. [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Università G. Marconi, Roma (Italy); Perillo, M. [EnginSoft S.p.a., Trento (Italy); Piacentino, G. [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Fermilab, Batavia, IL (United States); Università G. Marconi, Roma (Italy); Rella, S. [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Dipartimento di Ingegneria dell' Innovazione, Università del Salento (Italy); Rossetti, F. [EnginSoft S.p.a., Trento (Italy); Spedicato, M. [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Tassielli, G., E-mail: giovanni.tassielli@le.infn.it [Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Università G. Marconi, Roma (Italy); and others

    2013-08-01

    We present a novel low mass drift chamber concept, developed in order to fulfill the stringent requirements imposed by the experiments for extremely rare processes, which require high resolutions (order of 100–200 keV/c) for particle momenta in a range (50–100 MeV/c) totally dominated by the multiple scattering contribution. We describe a geometry optimization procedure and a new wiring strategy with a feed-through-less wire anchoring system developed and tested on a drift chamber prototype under completion at INFN-Lecce.

  18. The Multi-wire Ionization Chamber (DAVID)'s Influence on the Beams of Accelerator%多丝电离室(DAVID)系统对加速器射束的影响

    Institute of Scientific and Technical Information of China (English)

    徐慧军; 李玉; 张素静; 韩萍; 张军华

    2013-01-01

    Abjective: Through measuring the parameters of the accelerator beams under two conditions of uninstalled and installed DAVID system,to analyze DAVID system's influence on the beams. Methods: We chosed the Siemens ARTISTE Linear Accelerator which was allocated with a 160 MLC multi-leaf collimator, and the 6 MV X-ray was used. The model number of the multi-wire ionization chamber was T34084. Utilizing the equipments like 3D water tank and semiconductor detector to measure PDD, profile, TPR2010 and the absorbed dose underwater 5 cm under the conditions of uninstalled and installed DAVID system, we analyzed DAVID system's influence on the PDD, flatness, symmetry and actinogen of accelerator beams, and calculated the attenuation coefficient of DAVID system. Results: Under the two conditions of uninstalled and installed DAVID system, the R100 deviation of the three fields (5 cm×5 cm 、10 cm×10 cm and 20 cm×20 cm) lay between 0.6 mm ~1.3 mm, R80 deviation of them lay between 0.13 mm~0.66 mm, and R50 deviation lay between 0.38 mm~1.12 mm. The R100, R80, and R50 deviation of the fields of 40 cmx40 cm were 3.12 mm, 3.31 mm and 2.04 mm; The QI deviations were 0.0020, 0.0045, 0.0101, and 0.0061; The flatness deviation in the x and y direction was between 0.10%~0.58%; The symmetry deviation lay between 0.04%~0.26%; And the TPR2010 deviation was 0.002. The beams went across DAVID system and attenuated 7.67% of the dose. Conclusions: The comprehensive structure and making materials of DAVID system have little effect on the PDD, symmetry, flatness, and TPR2010 of the 6 MV X-ray beams, but the beams attenuate the dose when going across DAVID system.%目的:通过测量未安装和已安装DAVID系统两种情况下加速器射束的参数,分析DAVID系统对射束的影响.方法:西门子ARTISTE直线加速器,配备160叶多叶光栅,选择6 MV的X线.多丝电离室(DAVID),型号为T34084.利用三维水箱、半导体探测器等仪器测量未安装和已安

  19. The world's largest time projection chamber

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    Peter Glassel, the technical coordinator for the ALICE time projection chamber, is seen sitting inside the detector; the largest in the world at nearly 100 cubic metres. Thousands of wires are connected to read out electronic data produced as particles are created in lead-lead collisions at the centre of the detector. These particles will cause the medium within the time projection chamber to ionise along their tracks allowing the particle paths to be recreated.

  20. Evaluation of Carbon Dioxide Dissipation within a Euthanasia Chamber

    Science.gov (United States)

    Djoufack-Momo, Shelly M; Amparan, Ashlee A; Grunden, Beverly; Boivin, Gregory P

    2014-01-01

    CO2 euthanasia is used widely for small laboratory animals, such as rodents. A common necessity in many animal research facilities is to euthanize mice in sequential batches. We assessed the effects of several variables on the time it took for CO2 to dissipate within a chamber. Using standard euthanasia time, changes in flow rate were compared between a slow 15% fill rate for 7 min, and a slow 15% followed by a rapid 50% filling for a total of 5 min. Additional variables assessed included the effects of opening the lid after the completion of chamber filling, turning the chamber over after completion of filling, and the use and removal of a cage from within the chamber. For all trials, CO2 levels in the chambers peaked between 50% and 80%. After the gas was turned off, the concentration of CO2 dropped to below 10% CO2 within 2 min, except when the lid was left on the chamber, where concentration levels remained above 10% after 20 min. CO2 dissipation was significantly faster when the chamber was turned upside down after filling. Significant interaction effects occurred among the factors of cage presence within the chamber, flow rate, and chamber position. Only leaving the lid on the chamber had any practical implication for delaying CO2 dissipation. We recommend that users allow 2 min for CO2 to clear from the chamber before subsequent euthanasia procedures, unless the chamber is manipulated to increase the dissipation rate. PMID:25199098

  1. Evaluation of carbon dioxide dissipation within a euthanasia chamber.

    Science.gov (United States)

    Djoufack-Momo, Shelly M; Amparan, Ashlee A; Grunden, Beverly; Boivin, Gregory P-

    2014-07-01

    CO₂ euthanasia is used widely for small laboratory animals, such as rodents. A common necessity in many animal research facilities is to euthanize mice in sequential batches. We assessed the effects of several variables on the time it took for CO₂ to dissipate within a chamber. Using standard euthanasia time, changes in flow rate were compared between a slow 15% fill rate for 7 min, and a slow 15% followed by a rapid 50% filling for a total of 5 min. Additional variables assessed included the effects of opening the lid after the completion of chamber filling, turning the chamber over after completion of filling, and the use and removal of a cage from within the chamber. For all trials, CO₂ levels in the chambers peaked between 50% and 80%. After the gas was turned off, the concentration of CO₂ dropped to below 10% COv within 2 min, except when the lid was left on the chamber, where concentration levels remained above 10% after 20 min. CO₂ dissipation was significantly faster when the chamber was turned upside down after filling. Significant interaction effects occurred among the factors of cage presence within the chamber, flow rate, and chamber position. Only leaving the lid on the chamber had any practical implication for delaying CO₂ dissipation. We recommend that users allow 2 min for CO₂ to clear from the chamber before subsequent euthanasia procedures, unless the chamber is manipulated to increase the dissipation rate.

  2. Monte Carlo Simulation Optimizing Design of Grid Ionization Chamber

    Institute of Scientific and Technical Information of China (English)

    ZHENG; Yu-lai; WANG; Qiang; YANG; Lu

    2013-01-01

    The grid ionization chamber detector is often used for measuring charged particles.Based on Monte Carlo simulation method,the energy loss distribution and electron ion pairs of alpha particle with different energy have been calculated to determine suitable filling gas in the ionization chamber filled with

  3. Monte Carlo studies on Cathode Strip/Pad Chambers for the ALICE Di-Muon Arm

    Energy Technology Data Exchange (ETDEWEB)

    Wurzinger, R.; Le Bornec, Y.; Willis, N.

    1996-04-01

    A general overview about the properties of Cathode Strip and Pad Chambers is given. Position finding methods are discussed and compared within Monte Carlo studies. Noise contributions and their minimization are discussed. Pad chambers allow a two-dimensional readout with spatial resolution of {sigma} < 100 {mu}m in direction parallel to the anode wire. The resolution normal to the anode wire depends mainly on the wire spacing. Special attention is paid on the double-hit resolution capability of the pad chamber. An outlook is given on the possible utilisation of Cathode Pad Chambers in the Di-Muon Arm of the ALICE detector at LHC. (author). 44 refs.

  4. Design and operation of a setup with a camera and adjustable mirror to inspect the sense-wire planes of the Time Projection Chamber inside the MicroBooNE cryostat

    CERN Document Server

    Carls, Benjamin; James, Catherine C; Kubinski, Robert M; Pordes, Stephen; Schukraft, Anne; Strauss, Thomas

    2015-01-01

    Detectors in particle physics, particularly when including cryogenic components, are often enclosed in vessels that do not provide any physical or visual access to the detectors themselves after installation. However, it can be desirable for experiments to visually investigate the inside of the vessel. The MicroBooNE cryostat hosts a TPC with sense-wire planes, which had to be inspected for damage such as breakage or sagging. This paper describes an approach to view the inside of the MicroBooNE cryostat with a setup of a camera and a mirror through one of its cryogenic service nozzles. The paper describes the camera and mirror chosen for the operation, the illumination, and the mechanical structure of the setup. It explains how the system was operated and demonstrates its performance.

  5. Wireless transmission of biosignals for hyperbaric chamber applications.

    Science.gov (United States)

    Perez-Vidal, Carlos; Gracia, Luis; Carmona, Cristian; Alorda, Bartomeu; Salinas, Antonio

    2017-01-01

    This paper presents a wireless system to send biosignals outside a hyperbaric chamber avoiding wires going through the chamber walls. Hyperbaric chambers are becoming more and more common due to new indications of hyperbaric oxygen treatments. Metallic walls physically isolate patients inside the chamber, where getting a patient's vital signs turns into a painstaking task. The paper proposes using a ZigBee-based network to wirelessly transmit the patient's biosignals to the outside of the chamber. In particular, a wearable battery supported device has been designed, implemented and tested. Although the implementation has been conducted to transmit the electrocardiography signal, the device can be easily adapted to consider other biosignals.

  6. Soft magnetic wires

    Science.gov (United States)

    Vázquez, M.

    2001-06-01

    An overview of the present state of the art on the preparation techniques, outstanding magnetic properties and applications of soft magnetic micro and nanowires is presented. Rapid solidification techniques (in-rotating-water quenching and drawing methods) to fabricate amorphous microwires with diameter in the range from 100 down to 1 μm are first described. Electrodeposition is also employed to prepare composite microtubes (magnetic coatings) and to fill porous membranes (diameter of the order of 0.1 μm). Magnetic behaviours of interest are related to the different hysteresis loops of samples: square-shaped loops typical of bistable behaviour, and nearly non-hysteretic loop with well-defined transverse anisotropy field. The role played by magnetic dipolar interactions in the magnetic behaviour of arrays of micro and nanowires is described. A particular analysis is done on the giant magnetoimpedance (GMI) effect in the radio and microwave frequency ranges exhibited by ultrasoft microwires. Finally, a few examples of applications are introduced for magnetostrictive and non-magnetostrictive wires, they are: “magnetoelastic pens”, micromotors; DC current-sensors based on GMI, and sharpened amorphous wire tips in spin polarised scanning tunneling microscopy.

  7. Chamber transport

    Energy Technology Data Exchange (ETDEWEB)

    OLSON,CRAIG L.

    2000-05-17

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system.

  8. MEG II drift chamber characterization with the silicon based cosmic ray tracker at INFN Pisa

    Energy Technology Data Exchange (ETDEWEB)

    Venturini, M., E-mail: marco.venturini@pi.infn.it [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); Baldini, A.M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Baracchini, E. [ICEPP, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Cei, F.; D' Onofrio, A. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dipartimento di Fisica, dell' Università di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dussoni, S.; Galli, L.; Grassi, M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Nicolò, D. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Dipartimento di Fisica, dell' Università di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Signorelli, G. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy)

    2016-07-11

    High energy physics experiments at the high intensity frontier place ever greater demands on detectors, and in particular on tracking devices. In order to compare the performance of small size tracking prototypes, a high resolution cosmic ray tracker has been assembled to provide an external track reference. It consists of four spare ladders of the external layers of the Silicon Vertex Tracker of the BaBar experiment. The test facility, operating at INFN Sezione di Pisa, provides the detector under test with an external track with an intrinsic resolution of 15–30 μm. The MEG II tracker is conceived as a unique volume wire drift chamber filled with He–isobutane 85–15%. The ionization density in this gas mixture is about 13 clusters/cm and this results in a non-negligible bias of the impact parameters for tracks crossing the cell close to the anode wire. We present the telescope performance in terms of tracking efficiency and resolution and the results of the characterization of a MEG II drift chamber prototype.

  9. MEG II drift chamber characterization with the silicon based cosmic ray tracker at INFN Pisa

    Science.gov (United States)

    Venturini, M.; Baldini, A. M.; Baracchini, E.; Cei, F.; D`Onofrio, A.; Dussoni, S.; Galli, L.; Grassi, M.; Nicolò, D.; Signorelli, G.

    2016-07-01

    High energy physics experiments at the high intensity frontier place ever greater demands on detectors, and in particular on tracking devices. In order to compare the performance of small size tracking prototypes, a high resolution cosmic ray tracker has been assembled to provide an external track reference. It consists of four spare ladders of the external layers of the Silicon Vertex Tracker of the BaBar experiment. The test facility, operating at INFN Sezione di Pisa, provides the detector under test with an external track with an intrinsic resolution of 15-30 μm. The MEG II tracker is conceived as a unique volume wire drift chamber filled with He-isobutane 85-15%. The ionization density in this gas mixture is about 13 clusters/cm and this results in a non-negligible bias of the impact parameters for tracks crossing the cell close to the anode wire. We present the telescope performance in terms of tracking efficiency and resolution and the results of the characterization of a MEG II drift chamber prototype.

  10. 30 CFR 75.1003 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Science.gov (United States)

    2010-07-01

    ... wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 75.1003 Section 75.1003... Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. Trolley wires, trolley feeder wires, and bare signal wires shall be insulated...

  11. TU-F-BRE-03: Application of a Novel Mass-Density Compensation Optimization Method to Improve the Response of a Liquid-Filled Ionization Chamber in Nonstandard Fields

    Energy Technology Data Exchange (ETDEWEB)

    Kamio, Y [CHUM - Notre Dame, Montreal, QC (Canada); Bouchard, H [National Physical Laboratory, Teddington, Middlesex (United Kingdom)

    2014-06-15

    Purpose: To improve the response of the microLion detector (PTW 31018) in small field conditions by optimizing the density of the detector's non-sensitive components using a novel method based on the detector's dose response function. Methods: The central values h(0,0) of the perturbation functions for the microLion detector and a volume of water equivalent to its sensitive volume were calculated using the Monte Carlo user code egs-chamber by scoring the dose absorbed by a 6 MV photon pencil beam incident on their centroids. Values of h(0,0) were plotted as a function of the density of the microLion's graphite electrode with the detector placed in the axial orientation. The optimized density was found by finding the minimal value of h(0,0). Results: A density of 1.37 g/cm3 was found to minimize the perturbation function of the microLion detector. The modified microLion's response was then evaluated in small square fields with sides in the range of 5 – 40 mm and found to be consistent with highly watere-quivalent detectors such as a scintillating detector (Exradin W1) and a generic alanine detector in both axial and radial orientations. Conclusion: This work illustrates a novel method which can used to optimize the design of radiation detectors in small fields. This method should also work with other optimization parameters (e.g. thickness of electrode). Density-compensated detectors have the potential to eliminate the need to evaluate nonstandard field correction factors as described by the IAEA-AAPM formalism (Alfonso et al.) and simplify future dosimetry protocols for SRS/SBRT modalities. Finally, we also expect an improvement in the response of density-compensated detectors for composite IMRT fields.

  12. Studies with cathode drift chambers for the GlueX experiment at Jefferson Lab

    Science.gov (United States)

    Pentchev, L.; Barbosa, F.; Berdnikov, V.; Butler, D.; Furletov, S.; Robison, L.; Zihlmann, B.

    2017-02-01

    A drift chamber system consisting of 24 1 m-diameter chambers with both cathode and wire readout (total of 12,672 channels) is operational in Hall D at Jefferson Lab (Virginia). Two cathode strip planes and one wire plane in each chamber register the same avalanche allowing the study of avalanche development, charge induction process, and strip resolution. We demonstrate a method for reconstructing the two-dimensional distribution of the avalanche ;center-of-gravity; position around the wire from an 55Fe source with resolutions down to 30 μm. We estimate the azimuthal extent of the avalanche around the wire as a function of the total charge for an Ar/CO2 gas mixture. By means of cluster counting using a modified 3 cm-gap chamber, we observe significant space charge effects within the same track, resulting in an extent of the avalanche along the wire.

  13. Doriot Climatic Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers are two, 60-feet long, 11-feet high, 15-feet wide chambers that are owned and operated by NSRDEC. The Doriot Climatic Chambers are among...

  14. Hydrostatic Hyperbaric Chamber Ventilation System

    Science.gov (United States)

    Sarguisingh, Miriam J.

    2012-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy (HBOT) available in the developing world for the treatment of a variety of medical conditions. Specifically, HBOT is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. HBOT is simply too expensive and too dangerous to implement in the developing world using standard equipment. The HHC technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system to provide controlled pressurization and adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware

  15. Directed Energy Anechoic Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

  16. Cosmic Muon Detector Using Proportional Chambers

    CERN Document Server

    Varga, Dezső; Hamar, Gergő; Molnár, Janka Sára; Oláh, Éva; Pázmándi, Péter

    2015-01-01

    A set of classical multi-wire proportional chambers were designed and constructed with the main purpose of efficient cosmic muon detection. These detectors are relatively simple to construct, and at the same time are low cost, making them ideal for educational purposes. The detector layers have efficiencies above 99% for minimum ionizing cosmic muons, and their position resolution is about 1 cm, that is, particle trajectories are clearly observable. Visualization of straight tracks is possible using an LED array, with the discriminated and latched signal driving the display. Due to the exceptional operating stability of the chambers, the design can also be used for cosmic muon telescopes.

  17. Dielectron analysis in p-p collisions at 3.5 GeV with the HADES spectrometer. {omega}-meson line shape and a new electronics readout for the multi-wire drift chambers

    Energy Technology Data Exchange (ETDEWEB)

    Tarantola Peloni, Attilio

    2011-06-15

    . Conclusions are given in chapter four. The final part of this work is dedicated to the HADES upgrade, whose goal is among others the achievement of a reliable and fast data acquisition of the Multiwire Drift Chambers (MDCs). Chapter five presents my contribution to this successful project during the three years of my stay at GSI. (orig.)

  18. NUMERICLA SIMULATION ON DEFORMATION CHARACTERISTICS OF AS WIRE BY CAWTEX

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Castex(continuous cast and extrusion)is a latest metallurgical technology. Making of AS wire(aluminum-clad steel wire) by Castex is an advanced bonding technology of bimetal. In order to study the deformation character of AS wire the numerical simulation is performed with FE method. From the simulation result the following conclusions are obtained:① The simulation is carried out sequentially in three zones:initial extrusion,cavity-filling and bonding.② In the first zone the shearing deformation governs the whole zone,while in that of cavity-filling, the deformation mainly concentrates on transition arc of the concave mould. In addition, in the last zone, the dominant deformation lies at the boundary of concave mould, surface of steel wire and entry of sizing band. Due to the movement of steel wire, the direction of shear stress on its surface is opposite to that on the boundary of concave die.

  19. The great advance in the technology of particle detectors during the year was the discovery of the properties of multiwire proportional chambers and drift chambers

    CERN Multimedia

    1968-01-01

    In these chambers each wire is an independent proportional counter with its own amplifier and logic circuit. The low cost of the associated electronics makes realistic moderately large systems, with thousands of wires. The resolution time of each wire is of the order of 100 ns, with 3mm spacing. Roger Bouclier is working on an early model tested in a PS beam-line.

  20. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  1. Wire harness twisting aid

    Science.gov (United States)

    Casey, E. J.; Commadore, C. C.; Ingles, M. E.

    1980-01-01

    Long wire bundles twist into uniform spiral harnesses with help of simple apparatus. Wires pass through spacers and through hand-held tool with hole for each wire. Ends are attached to low speed bench motor. As motor turns, operator moves hand tool away forming smooth twists in wires between motor and tool. Technique produces harnesses that generate less radio-frequency interference than do irregularly twisted cables.

  2. Water Desalination with Wires

    NARCIS (Netherlands)

    Porada, S.; Sales, B.B.; Hamelers, H.V.M.; Biesheuvel, P.M.

    2012-01-01

    We show the significant potential of water desalination using a novel capacitive wire-based technology in which anode/cathode wire pairs are constructed from coating a thin porous carbon electrode layer on top of electrically conducting rods (or wires). By alternately dipping an array of electrode

  3. NA48: Wiring up for Change

    CERN Multimedia

    2001-01-01

    The NA48 Collaboration is rebuilding its drift chambers ready for the experiment to start up again this coming July. An intricate task involving the soldering of over 24,000 wires! The future of the NA48 experiment is coming right down to the wire, that is, the wires which the Collaboration is installing in the clean room of Hall 887 on the Prévessin site. Six days a week, technicians are working in shifts to rebuild the experiment's drift chambers. The original chambers were damaged when a section of a vacuum tube imploded at the end of 1999. A year ago, CERN gave the green light for this essential part of the spectrometer to be rebuilt, so the NA48 experiment, which studies CP violation (see box), still has a bright future ahead of it. Three years of data-taking ahead The NA48 experiment aims to penetrate the secrets of CP (Charge Parity) violation. Charge and parity are two parameters which distinguish a particle from an antiparticle. In other words, an electron possesses a negative electric ...

  4. About Dental Amalgam Fillings

    Science.gov (United States)

    ... and Medical Procedures Dental Devices Dental Amalgam About Dental Amalgam Fillings Share Tweet Linkedin Pin it More ... should I have my fillings removed? What is dental amalgam? Dental amalgam is a dental filling material ...

  5. Effect of wire shape on wire array discharge

    Energy Technology Data Exchange (ETDEWEB)

    Shimomura, N.; Tanaka, Y.; Yushita, Y.; Nagata, M. [University of Tokushima, Department of Electrical and Electronic Engineering, Tokushima (Japan); Teramoto, Y.; Katsuki, S.; Akiyama, H. [Kumamoto University, Department of Electrical and Computer Engineering, Kumamoto (Japan)

    2001-09-01

    Although considerable investigations have been reported on z-pinches to achieve nuclear fusion, little attention has been given from the point of view of how a wire array consisting of many parallel wires explodes. Instability existing in the wire array discharge has been shown. In this paper, the effect of wire shape in the wire array on unstable behavior of the wire array discharge is represented by numerical analysis. The claws on the wire formed in installation of wire may cause uniform current distribution on wire array. The effect of error of wire diameter in production is computed by Monte Carlo Method. (author)

  6. The CAST Time Projection Chamber

    CERN Document Server

    Autiero, D; Cébrian, S; Carmona, J M; Chesi, Enrico Guido; Davenport, M; Delattre, M; Di Lella, L; Formenti, F; Gomez, H; Hasinoff, M; Irastorza, I G; Lakic, B; Luzón, G; Morales, J; Musa, L; Ortiz, A; Placci, A; Rodríguez, A; Ruz, J; Villar, J A; Zioutas, K

    2007-01-01

    One of the three X-ray detectors of the CAST experiment searching for solar axions is a Time Projection Chamber (TPC) with a multi-wire proportional counter (MWPC) as a readout structure. Its design has been optimized to provide high sensitivity to the detection of the low intensity X-ray signal expected in the CAST experiment. A low hardware threshold of 0.8 keV is safely set during normal data taking periods, and the overall efficiency for the detection of photons coming from conversion of solar axions is 62 %. Shielding has been installed around the detector, lowering the background level to 4.10 x 10^-5 counts/cm^2/s/keV between 1 and 10 keV. During phase I of the CAST experiment the TPC has provided robust and stable operation, thus contributing with a competitive result to the overall CAST limit on axion-photon coupling and mass.

  7. Polyurethane spray coating of aluminum wire bonds to prevent corrosion and suppress resonant oscillations

    CERN Document Server

    Izen, Joseph; The ATLAS collaboration; Kurth, Matthew Glenn

    2015-01-01

    Unencapsulated aluminum wedge wire bonds are common in particle-physics pixel and strip detectors. Industry-favored bulk encapsulation is eschewed due to the range of operating temperatures and radiation. Wire bond failures are a persistent, source of tracking detector failure Unencapsulated bonds are vulnerable to condensation-induced corrosion, particularly when halides are present. Oscillations from periodic Lorenz forces are documented as another source of wire bond failure. Spray application of polyurethane coatings, performance of polyurethane-coated wire bonds after climate chamber exposure, and resonant properties of PU-coated wire bonds and their resistance to periodic Lorenz forces will be described.

  8. ISR Intersection Vacuum Chamber

    CERN Multimedia

    1975-01-01

    This special vacuum chamber presenting a lateral opening at the beam crossing point is one of the many chambers specifically designed for a particular experiment. Here it is shown during assembly at the ISR mechanical worshop.

  9. 30 CFR 77.1802 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Science.gov (United States)

    2010-07-01

    ... wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 77.1802 Section 77.1802... Wires and Trolley Feeder Wires § 77.1802 Insulation of trolley wires, trolley feeder wires and bare..., and bare signal wires shall be adequately guarded: (a) At all points where men are required to work or...

  10. Aging tests of full-scale CMS muon cathode strip chambers

    CERN Document Server

    Acosta, D; Arisaka, K; Bondar, N; Breedon, R; Bujak, A; Bylsma, B; Chester, N; Clare, R; Cline, D; Cousins, R; Cox, T; Dolinski, S I; Durkin, S; Eartly, D; Ivanov, Yu; Ferguson, T; Gavrilov, G; Gilmore, J; Gu, J; Gutay, L; Hann, F; Hartmut, R; Hauser, J; He, K; Ignatenko, M A; Ilie, S; Jiang, C; Ko, W; Korytov, A; Krivshich, A G; Kuznetsova, K; Layter, J; Lee, R; Levchenko, P M; Ling, T Y; Loveless, D; Lusin, S; Maeshima, K; Madorsky, A; Matthey, C; Matveev, M; Von der Mey, M; Mitselmakher, G; Otwinowski, S; Padley, P; Pal, I; Pischalnikov, Y; Prokofiev, O E; Razmyslovich, B V; Reeder, D; Roberts, J; Schipunov, L; Smirnov, I; Souvorov, V; Stasko, J T; Sun, H; Sytnik, V V; Terentyev, N K; Tripathi, M; Vavilov, S; Volkov, S; Vorobyov, A; Vorobyov, I A; Wang, L; Yarba, V A; Zhou, L; Zhu, Z

    2003-01-01

    Two CMS production Cathode Strip Chambers were tested for aging effects in a high-radiation environment at the Gamma Irradiation Facility at CERN. The chambers were irradiated over a large area: in total, about 2.1m**2 or 700m of wire in each chamber. The 40% Ar+50% CO//2+10% CF//4 gas mixture was provided by an open-loop gas system for one of the chambers and by a closed-loop re-circulating gas system for the other. After an accumulation of 0.3-0.4C/cm of a wire, equivalent to about 30-50 years of operation at peak LHC luminosity, no significant changes in gas gain, chamber efficiency and wire signal noise were observed for either of the two chambers. The only consistent signs of aging were a small increase in dark current from 2 to 10nA per plane of 600 wires and a decrease of strip-to-strip resistance from 1000 to 10-100GOmega. Disassembly of the chambers revealed deposits on the cathode planes, while the anode wires remained fairly clean.

  11. Limits to Drift Chamber Resolution

    CERN Document Server

    Riegler, Werner

    1998-01-01

    ATLAS (A Large Toroidal LHC Apparatus) will be a general-purpose experiment at the Large Hadron Collider that will be operational at CERN in the year 2004. The ATLAS muon spectrometer aims for a momentum resolution of 10% for a transverse momentum of pT=1TeV. The precision tracking devices in the muon system will be high pressure drift tubes (MDTs) with a single wire resolution of 1100 chambers covering an area of ≈ 2500m2. The high counting rates in the spectrometer as well as the aim for excellent spatial resolution and high efficiency put severe constraints on the MDT operating parameters. This work describes a detailed study of all the resolution limiting factors in the ATLAS environment. A ’full chain’ simulation of the MDT response to photons and charged particles as well as quantitative comparisons with measurements was performed. The good agreement between simulation and measurements resulted in a profound understanding of the drift chamber processes and the individual contributions to the spat...

  12. Vibrating wire alignment technique

    CERN Document Server

    Xiao-Long, Wang; lei, Wu; Chun-Hua, Li

    2013-01-01

    Vibrating wire alignment technique is a kind of method which through measuring the spatial distribution of magnetic field to do the alignment and it can achieve very high alignment accuracy. Vibrating wire alignment technique can be applied for magnet fiducialization and accelerator straight section components alignment, it is a necessary supplement for conventional alignment method. This article will systematically expound the international research achievements of vibrating wire alignment technique, including vibrating wire model analysis, system frequency calculation, wire sag calculation and the relation between wire amplitude and magnetic induction intensity. On the basis of model analysis this article will introduce the alignment method which based on magnetic field measurement and the alignment method which based on amplitude and phase measurement. Finally, some basic questions will be discussed and the solutions will be given.

  13. Wire + Arc Additive Manufacturing

    OpenAIRE

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  14. Photovoltaic Wire Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will investigate a new architecture for photovoltaic devices based on nanotechnology: photovoltaic wire. The...

  15. On-Wire Lithography

    National Research Council Canada - National Science Library

    Lidong Qin; Sungho Park; Ling Huang; Chad A. Mirkin

    2005-01-01

    .... This procedure, termed on-wire lithography, combines advances in template-directed synthesis of nanowires with electrochemical deposition and wet-chemical etching and allows routine fabrication...

  16. The experimental and numerical investigation of a grooved vapor chamber

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ming [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China); Liu Zhongliang [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China)], E-mail: liuzhl@bjut.edu.cn; Ma Guoyuan [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Education Commission, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China)

    2009-02-15

    An effective thermal spreader can achieve more uniform heat flux distribution and thus enhance heat dissipation of heat sinks. Vapor chamber is one of highly effective thermal spreaders. In this paper, a novel grooved vapor chamber was designed. The grooved structure of the vapor chamber can improve its axial and radial heat transfer and also can form the capillary loop between condensation and evaporation surfaces. The effect of heat flux, filling amount and gravity to the performance of this vapor chamber is studied by experiment. From experiment, we also obtained the best filling amount of this grooved vapor chamber. By comparing the thermal resistance of a solid copper plate with that of the vapor chamber, it is suggested that the critical heat flux condition should be maintained to use vapor chamber as efficient thermal spreaders for electronics cooling. A two-dimensional heat and mass transfer model for the grooved vapor chamber is developed. The numerical simulation results show the thickness distribution of liquid film in the grooves is not uniform. The temperature and velocity field in vapor chamber are obtained. The thickness of the liquid film in groove is mainly influenced by pressure of vapor and liquid beside liquid-vapor interface. The thin liquid film in heat source region can enhance the performance of vapor chamber, but if the starting point of liquid film is backward beyond the heat source region, the vapor chamber will dry out easily. The optimal filling ratio should maintain steady thin liquid film in heat source region of vapor chamber. The vapor condenses on whole condensation surface, so that the condensation surface achieves great uniform temperature distribution. By comparing the experimental results with numerical simulation results, the reliability of the numerical model can be verified.

  17. 1998 wire development workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development.

  18. Microcrystalline silicon from very high frequency plasma deposition and hot-wire CVD for ``micromorph`` tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Brummack, H.; Brueggemann, R.; Wanka, H.N.; Hierzenberger, A.; Schubert, M.B. [Univ. Stuttgart (Germany). Inst. fuer Physikalische Elektronik

    1997-12-31

    The authors have grown microcrystalline silicon from a glow discharge at very high frequencies of 55 MHz and 170 MHz with high hydrogen dilution, and also, at more than 10 times higher growth rates, similar films by hot-wire chemical vapor deposition. Both kinds of materials have extensively been characterized and compared in terms of structural, optical and electronic properties, which greatly improve by deposition in a multi- instead of a single-chamber system. Incorporation of these different materials into pin solar cells results in open circuit voltages of about 400 mV as long as the doped layers are microcrystalline and rise to more than 870 mV if amorphous p- and n-layers are used. Quantum efficiencies and fill factors are still poor but leave room for further improvement, as clearly demonstrated by a remarkable reverse bias quantum efficiency gain.

  19. PICO Bubble Chambers for Dark Matter Searches: Future Prospects

    Science.gov (United States)

    Neilson, Russell; PICO Collaboration

    2017-01-01

    The PICO collaboration uses bubble chambers to search for WIMP dark matter particles. The bubble chambers are operated in a moderately superheated state, providing superb rejection of the dominant gamma background, and are filled with fluorinated target fluids ideally suited for investigating spin-dependent WIMP-proton interactions. PICO currently operates a 2-liter (PICO-2L) and a 32-liter (PICO-60) bubble chamber at the SNOLAB deep underground laboratory. I will discuss recent activities by the PICO collaboration to understand and mitigate an anomalous background that has impacted previous dark matter searches, plans for the operating experiments, and prospects for a future ton-scale PICO bubble chamber.

  20. Wire Array Photovoltaics

    Science.gov (United States)

    Turner-Evans, Dan

    Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar. Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry. The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires. Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction

  1. Wireless transmission of biosignals for hyperbaric chamber applications

    Science.gov (United States)

    Perez-Vidal, Carlos; Gracia, Luis; Carmona, Cristian; Alorda, Bartomeu; Salinas, Antonio

    2017-01-01

    This paper presents a wireless system to send biosignals outside a hyperbaric chamber avoiding wires going through the chamber walls. Hyperbaric chambers are becoming more and more common due to new indications of hyperbaric oxygen treatments. Metallic walls physically isolate patients inside the chamber, where getting a patient’s vital signs turns into a painstaking task. The paper proposes using a ZigBee-based network to wirelessly transmit the patient's biosignals to the outside of the chamber. In particular, a wearable battery supported device has been designed, implemented and tested. Although the implementation has been conducted to transmit the electrocardiography signal, the device can be easily adapted to consider other biosignals. PMID:28296900

  2. The operation of a track sensitive hydrogen target in a 500 l neon hydrogen bubble chamber

    CERN Document Server

    Ayres, J F; Damerell, A R; Fisher, Colin M; Fitzharris, E W; Foster, J H; Gottfeldt, P; Mack, B; Mortimer, A R; Seager, P; Stokoe, J R; Williams, P R; Leutz, H; Tischhauser, Johann; Wenninger, Horst

    1973-01-01

    A 20 l hydrogen filled track sensitive target has been successfully operated in the 1.5 m cryogenic bubble chamber at The Rutherford High Energy Laboratory. The chamber is filled with a mixture of neon and hydrogen at a concentration of 45 mol eon giving a radiation length of 860 mm. Satisfactory track quality in both target and chamber is achieved and 65000 pictures have been obtained in a 4 GeV/c pi /sup +/ beam. (7 refs).

  3. Getting a prescription filled

    Science.gov (United States)

    ... are located inside of a grocery or large "chain" store. It is best to fill all prescriptions ... be used for long-term medicines and medical supplies. The website should have clear directions for filling ...

  4. High Accuracy, Two-Dimensional Read-Out in Multiwire Proportional Chambers

    Science.gov (United States)

    Charpak, G.; Sauli, F.

    1973-02-14

    In most applications of proportional chambers, especially in high-energy physics, separate chambers are used for measuring different coordinates. In general one coordinate is obtained by recording the pulses from the anode wires around which avalanches have grown. Several methods have been imagined for obtaining the position of an avalanche along a wire. In this article a method is proposed which leads to the same range of accuracies and may be preferred in some cases. The problem of accurate measurements for large-size chamber is also discussed.

  5. Fast and High Accuracy Wire Scanner

    CERN Document Server

    Koujili, M; Koopman, J; Ramos, D; Sapinski, M; De Freitas, J; Ait Amira, Y; Djerdir, A

    2009-01-01

    Scanning of a high intensity particle beam imposes challenging requirements on a Wire Scanner system. It is expected to reach a scanning speed of 20 m.s-1 with a position accuracy of the order of 1 μm. In addition a timing accuracy better than 1 millisecond is needed. The adopted solution consists of a fork holding a wire rotating by a maximum of 200°. Fork, rotor and angular position sensor are mounted on the same axis and located in a chamber connected to the beam vacuum. The requirements imply the design of a system with extremely low vibration, vacuum compatibility, radiation and temperature tolerance. The adopted solution consists of a rotary brushless synchronous motor with the permanent magnet rotor installed inside of the vacuum chamber and the stator installed outside. The accurate position sensor will be mounted on the rotary shaft inside of the vacuum chamber, has to resist a bake-out temperature of 200°C and ionizing radiation up to a dozen of kGy/year. A digital feedback controller allows maxi...

  6. Development of a portable and fast wire tension measurement system for MWPC construction

    Science.gov (United States)

    Pan, Jing-Hui; Ma, Chang-Li; Gong, Xue-Yu; Sun, Zhi-Jia; Wang, Yan-Feng; Yin, Chen-Yan; Gong, Lei

    2016-09-01

    In a multi-wire proportional chamber detector (MWPC), the anode and signal wires must maintain suitable tension, which is very important for the detector’s stable and accurate performance. As a result, wire tension control and measurement is essential in MWPC construction. A high pressure 3He MWPC detector is to be used as the thermal neutron detector of the multi-functional reflectometer at China Spallation Neutron Source, and in the construction of the detector, we have developed a wire tension measurement system. This system is accurate, portable and time-saving. With it, the wire tension on an anode wire plane has been tested. The measurement results show that the wire tension control techniques used in detector manufacture are reliable. Supported by National Natural Science Foundation of China (A050506), State Key Laboratory of Particle Detection and Electronics and Key Laboratory of China Academy of Engineering Physics (Y490KF40HD)

  7. Development of a portable, fast and contactless wire tension measurement system for MWPC's construction

    CERN Document Server

    Pan, Jing-Hui; Gong, Xue-Yu; Sun, Zhi-Jia; Wang, Yan-Feng; Yin, Chen-Yan; Gong, Lei

    2016-01-01

    In a multi-wire proportional chamber detector(MWPC), the anode and signal wires must maintain suitable tensions, which is very important for making the detector have steady and perfect performance. As a result, wire tension control and measurement is essential in MWPC's construction. The thermal neutron detector of multi-functional reflectometer at China Spallation Neutron Source is designed using a hight pressure $^{3}$He MWPC detector, and in the construction of the detector, we developed a wire tension measurement system. This system is accurate, portable and time-saving. And, the wires' tension on a anode wire plane has been tested with it, the measurement results shown the wire tension control techniques used in detector manufacture is reliable.

  8. Radiation damage control in the BNL hypernuclear spectrometer drift chamber system

    Energy Technology Data Exchange (ETDEWEB)

    Pile, P.H.

    1986-01-01

    A high rate drift chamber system has been in use at the BNL hypernuclear spectrometer system for the past three years. Some of the chambers have accumulated charge doses up to about 0.2 C/cm-wire without showing external signs of aging. The system design and performance will be discussed as well as the results of some laboratory drift chamber aging tests. 5 refs., 9 figs.

  9. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  10. Electromagnetic reverberation chambers

    CERN Document Server

    Besnier, Philippe

    2013-01-01

    Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

  11. Refrigeration Test Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The enclosed and environmentally controlled chamber is able to test four units (single-phase) simultaneously at conditions ranging from tundra to desert temperatures...

  12. DORIOT CLIMATIC CHAMBERS

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers reproduce environmental conditions occurring anywhere around the world. They provide an invaluable service by significantly reducing the...

  13. Drift Chamber Alignment using Cosmic Rays

    Energy Technology Data Exchange (ETDEWEB)

    Kotwal, Ashutosh V. [Duke U.; Hays, Christopher P. [Oxford U.

    2014-05-07

    The Collider Detector at Fermilab (CDF) is a general-purpose experimental apparatus with an inner tracking detector for measuring charged particles, surrounded by a calorimeter for measurements of electromagnetic and hadronic showers, and a muon detector system. We present a technique for, and results of, a precise relative alignment of the drift chamber wires of the CDF tracker. This alignment has been an important component of the track momentum calibration, which is the basis for the charged-lepton calibration for the measurement of the W boson mass at CDF.

  14. Drift Chamber Alignment using Cosmic Rays

    CERN Document Server

    Kotwal, Ashutosh V

    2014-01-01

    The Collider Detector at Fermilab (CDF) is a general-purpose experimental apparatus with an inner tracking detector for measuring charged particles, surrounded by a calorimeter for measurements of electromagnetic and hadronic showers, and a muon detector system. We present a technique for, and results of, a precise relative alignment of the drift chamber wires of the CDF tracker. This alignment has been an important component of the track momentum calibration, which is the basis for the charged-lepton calibration for the measurement of the W boson mass at CDF.

  15. The Bern Infinitesimal Bubble Chamber (BIBC)

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    The chamber body was machined from a block of aluminium. The visible volume was cylindrical with 65 mm diameter and 35 mm depth. It was filled with propane or freon. It was meant as vertex detector in the search of short-lived particles. It was also used with in-line holography resulting in 8 µm bubble size and 9 cm depth of the field. See E. Ramseyer, B. Hahn and E. Hugentobler, Nucl. Instrum. Methods 201 (1982) 335.

  16. DELPHI time projection chamber

    CERN Multimedia

    1989-01-01

    The time projection chamber is inserted inside the central detector of the DELPHI experiment. Gas is ionised in the chamber as a charged particle passes through, producing an electric signal from which the path of the particle can be found. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  17. Fluidized bed combustion chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kullendorff, A.; Wikner, J.

    1985-03-25

    The chamber is confined in a pressure vessel. The lower part of the chamber has tilted parallel gutters up to the height of the fluidized bed. The slope of the gutter walls is 5 degrees-15 degrees and the top area of the gutters is 1.3 to 3 times larger than their bottom.

  18. Target chambers for gammashpere

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Falout, J.W.; Nardi, B.G. [and others

    1995-08-01

    One of our responsibilities for Gammasphere, was designing and constructing two target chambers and associated beamlines to be used with the spectrometer. The first chamber was used with the early implementation phase of Gammasphere, and consisted of two spun-Al hemispheres welded together giving a wall thickness of 0.063 inches and a diameter of 12 inches.

  19. Climatic chamber ergometer

    CSIR Research Space (South Africa)

    Atkins, AR

    1968-01-01

    Full Text Available The design and calibration of an ergometer for exercising subjects during calorimetric studies in the climate chamber, are described. The ergometer is built into the climatic chamber and forms an integral part of the whole instrumentation system foe...

  20. BEBC bubble chamber

    CERN Multimedia

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  1. The Mobile Chamber

    Science.gov (United States)

    Scharfstein, Gregory; Cox, Russell

    2012-01-01

    A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

  2. CHAMBER OF COMMERCE INFORMATION

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Experience Japan The Japanese Chamber of Commerce and Industry will further promote its Japan-experience program and seek cooperation with various Chinese institutions.Between early May and June 2007,the chamber organized a Chinese college student delegation to Japan with the support from its members in China.

  3. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  4. Construction and Test of the Precision Drift Chambers for the ATLAS Muon Spectrometer

    CERN Document Server

    Bauer, F; Bratzler, U; Dietl, H; Kotov, S; Kroha, H; Lagouri, Th; Manz, A; Ostapchuk, A; Richter, R; Schael, S; Chouridou, S; Deile, M; Kortner, O; Staude, A; Stroehmer, R; Trefzger, T

    2016-01-01

    The Monitored Drift Tube (MDT) chambers for the muon spectrometer of the ATLAS detector at the Large Hadron Collider (LHC) consist of 3-4 layers of pressurised drift tubes on either side of a space frame carrying an optical deformation monitoring system. The chambers have to provide a track position resolution of 40 microns with a single-tube resolution of at least 80 microns and a sense wire positioning accu- racy of 20 ?microns (rms). The feasibility was demonstrated with the full-scale prototype of one of the largest MDT chambers with 432 drift tubes of 3.8 m length. For the ATLAS muon spectrometer, 88 chambers of this type have to be built. The first chamber has been completed with a wire positioning accuracy of 14 microns (rms).

  5. OPAL Jet Chamber Prototype

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

  6. Tracking chamber made of 15-mm mylar drift tubes

    Science.gov (United States)

    Kozhin, A.; Borisov, A.; Bozhko, N.; Fakhrutdinov, R.; Plotnikov, I.

    2017-05-01

    We are presenting a drift chamber composed from three layers of mylar drift tubes with outer diameter 15 mm. The pipe is made of strip of mylar film 125 micrometers thick covered with aluminium from the both sides. A strip of mylar is wrapped around the mandrel. Pipe is created by ultrasonic welding. A single drift tube is self-supported structure withstanding 350 g wire tension without supports and internal overpressure. About 400 such tubes were assembled. Design, quality control procedures of the drift tubes are described. Seven chambers were glued from these tubes of 560 mm length. Each chamber consists of 3 layers, 16 tubes per layer. Several chambers were tested with cosmic rays. Results of the tests, counting rate plateau and coordinate resolution are presented.

  7. Photonic band gap in thin wire metamaterials.

    Science.gov (United States)

    Hock, Kai Meng

    2008-03-01

    We investigate the band structure of a class of photonic crystals made from only thin wires. Using a different method, we demonstrate that a complete photonic band gap is possible for such materials. Band gap materials normally consist of space filling dielectric or metal, whereas thin wires occupy a very small fraction of the volume. We show that this is related to the large increase in scattering at the Brillouin zone boundary. The method we developed brings together the calculation techniques in three different fields. The first is the calculation of scattering from periodic, tilted antennas, which we improve upon. The second is the standard technique for frequency selective surface design. The third is obtained directly from low energy electron diffraction theory. Good agreements with experiments for left handed materials, negative materials, and frequency selective surfaces are demonstrated.

  8. The CAST time projection chamber

    Science.gov (United States)

    Autiero, D.; Beltrán, B.; Carmona, J. M.; Cebrián, S.; Chesi, E.; Davenport, M.; Delattre, M.; Di Lella, L.; Formenti, F.; Irastorza, I. G.; Gómez, H.; Hasinoff, M.; Lakic, B.; Luzón, G.; Morales, J.; Musa, L.; Ortiz, A.; Placci, A.; Rodrigurez, A.; Ruz, J.; Villar, J. A.; Zioutas, K.

    2007-06-01

    One of the three x-ray detectors of the CERN Axion Solar Telescope (CAST) experiment searching for solar axions is a time projection chamber (TPC) with a multi-wire proportional counter (MWPC) as a readout structure. Its design has been optimized to provide high sensitivity to the detection of the low intensity x-ray signal expected in the CAST experiment. A low hardware threshold of 0.8 keV is set to a safe level during normal data taking periods, and the overall efficiency for the detection of photons coming from conversion of solar axions is 62%. Shielding has been installed around the detector, lowering the background level to 4.10 × 10-5 counts cm-2 s-1 keV-1 between 1 and 10 keV. During phase I of the CAST experiment the TPC has provided robust and stable operation, thus contributing with a competitive result to the overall CAST limit on axion photon coupling and mass.

  9. ALICE Time Projection Chamber

    CERN Multimedia

    Lippmann, C

    2013-01-01

    The Time Projection Chamber (TPC) is the main device in the ALICE 'central barrel' for the tracking and identification (PID) of charged particles. It has to cope with unprecedented densities of charges particles.

  10. Vacuum chamber 'bicone'

    CERN Multimedia

    1977-01-01

    This chamber is now in the National Museum of History and Technology, Smithsonian Institution, Washington, DC, USA, where it was exposed in an exhibit on the History of High Energy Accelerators (1977).

  11. Toxic Test Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — Description/History: Hazardous material test facility Both facilities have 16,000 cubic foot chambers, equipped with 5000 CFM CBR filter systems with an air change...

  12. Bubble chamber: antiproton annihilation

    CERN Multimedia

    1971-01-01

    These images show real particle tracks from the annihilation of an antiproton in the 80 cm Saclay liquid hydrogen bubble chamber. A negative kaon and a neutral kaon are produced in this process, as well as a positive pion. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  13. Water-filled telescopes

    CERN Document Server

    Antonello, E

    2014-01-01

    In this short note we discuss the case of the thought experiments on water-filled telescopes and their realizations during 18th and 19th century. The story of those instruments shows that the scientific progress occurs in a curious way, since there was no stringent reason for the construction of a water-filled telescope.

  14. Central tracking chamber with inflated cathode-strip foils

    Energy Technology Data Exchange (ETDEWEB)

    Blackmore, E.W.; Bryman, D.A.; Kuno, Y.; Lim, C.; Numao, T.; Padley, P.; Redlinger, G.; Soluk, R. [TRIUMF, Vancouver, BC (Canada); McPherson, R.A. [Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States)

    1998-02-21

    A new cylindrical low-mass central drift chamber has been constructed for the K{sup +}{yields}{pi}{sup +}{nu} anti {nu} experiment at BNL (E787). The chamber consists of twelve layers of axial wire cells and six layers of thin cathode-strip foils, four of which are supported by differential gas pressure. The momentum resolution (RMS) for muons and pions in the range 150-250 MeV/c is found to be about 0.9%. (orig.). 16 refs.

  15. Thermal Control Method for High-Current Wire Bundles by Injecting a Thermally Conductive Filler

    Science.gov (United States)

    Rodriguez-Ruiz, Juan; Rowles, Russell; Greer, Greg

    2011-01-01

    A procedure was developed to inject thermal filler material (a paste-like substance) inside the power wire bundle coming from solar arrays. This substance fills in voids between wires, which enhances the heat path and reduces wire temperature. This leads to a reduced amount of heat generated. This technique is especially helpful for current and future generation high-power spacecraft (1 kW or more), because the heat generated by the power wires is significant enough to cause unacceptable overheating to critical components that are in close contact with the bundle.

  16. Study and Application of Sealing Material for Coke Oven Chamber

    Institute of Scientific and Technical Information of China (English)

    GAN Feifang; TAI Li

    2005-01-01

    A kind of dry refractory sealing material has been developed to repair the fine cracks in coke oven chamber. With silica sand as the main raw material, the sealing material is blown into coke oven chamber by compressed air while being applied, and bonded to brick surface or filled in fine cracks of chamber under right pressure. The physical properties of the material are similar to those of silica bricks during its application. So it can be adapted to conditions of coke oven and has good service life. The study and application results of the sealing material are described in this paper.

  17. A ring-shaped recombination chamber for hadron therapy dosimetry.

    Science.gov (United States)

    Jakubowska, E; Zielczyński, M; Golnik, N; Gryziński, M A; Krzemiński, Ł

    2014-10-01

    An innovative recombination chamber has been designed for estimation of stray radiation doses and quality factors in hadron therapy. The chamber allows for determination of absorbed dose and recombination index of radiation quality in phantoms at small distances from simulated organs. The chamber body and electrodes are ring shaped, so the beam may be directed through the empty centre of the ring. The ionisation of the filling gas is caused by secondary or scattered radiation and can be related to the dose absorbed in the tissues close to the irradiated target volume.

  18. Distribution of wire deformation within strands of wire ropes

    Institute of Scientific and Technical Information of China (English)

    MA Jun; GE Shi-rong; ZHANG De-kun

    2008-01-01

    Using ANSYS software, we developed a modeling program for several kinds of wire ropes with metal cores and built a geometric model for the 6x19 IWS wire rope. Through proper grid partitioning, a finite element model for calculating the deformation of wire rope was obtained. Completely constraining one end of the wire rope and applying an axial force to the other end, we established the boundary conditions for solving the model. In addition, we numerically simulated the stress and deformation of the wire, obtaining the deformation distribution of each wire within the wire rope under different laying directions.At the end, a tensile test of the 6x19 IWS wire rope was carried out and the results of simulation and experiment compared.

  19. Electric wiring domestic

    CERN Document Server

    Coker, A J

    1992-01-01

    Electric Wiring: Domestic, Tenth Edition, is a clear and reliable guide to the practical aspects of domestic electric wiring. Intended for electrical contractors, installation engineers, wiremen and students, its aim is to provide essential up to date information on modern methods and materials in a simple, clear, and concise manner. The main changes in this edition are those necessary to bring the work into line with the 16th Edition of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers. The book begins by introducing the basic features of domestic

  20. Wiring and lighting

    CERN Document Server

    Kitcher, Chris

    2013-01-01

    Wiring and Lighting provides a comprehensive guide to DIY wiring around the home. It sets out the regulations and legal requirements surrounding electrical installation work, giving clear guidelines that will enable the reader to understand what electrical work they are able to carry out, and what the testing and certification requirements are once the work is completed. Topics covered include: Different types of circuits; Types of cables and cable installation under floors and through joists; Isolating, earthing and bonding; Accessory boxes and fixings; Voltage bands; Detailed advice on safe

  1. Modern wiring practice

    CERN Document Server

    Steward, W E

    2012-01-01

    Continuously in print since 1952, Modern Wiring Practice has now been fully revised to provide an up-to-date source of reference to building services design and installation in the 21st century. This compact and practical guide addresses wiring systems design and electrical installation together in one volume, creating a comprehensive overview of the whole process for contractors and architects, as well as electricians and other installation engineers. Best practice is incorporated throughout, combining theory and practice with clear and accessible explanation, all

  2. Compact drift-chambers for the OPAL forward detectors

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, B.E.; Attree, D.J.; Charalambous, A.; Cranfield, R.; Cresswell, M.; Crone, G.; Dallavalle, G.M.; Dryburgh, M.; Kennedy, B.W.; Hayes, D.; Marradi, L.; Miller, D.J.; Sherwood, P.; Spreadbury, E.; Wood, N.C.; Young, K.K. (University Coll., London (UK). Dept. of Physics and Astronomy)

    1989-11-10

    Two planes of four chambers are mounted in front of the forward calorimeter at each end of OPAL. Beam tests at CERN show good linearity (within 0.5 mm over 130 mm maximum drift) and good resolution in the drift direction (average 300 {mu}m over the whole range of drift distances). The resolution along the wire is {plus minus}1 mm. (orig.).

  3. Improved Rhenium Thrust Chambers

    Science.gov (United States)

    O'Dell, John Scott

    2015-01-01

    Radiation-cooled bipropellant thrust chambers are being considered for ascent/ descent engines and reaction control systems on various NASA missions and spacecraft, such as the Mars Sample Return and Orion Multi-Purpose Crew Vehicle (MPCV). Currently, iridium (Ir)-lined rhenium (Re) combustion chambers are the state of the art for in-space engines. NASA's Advanced Materials Bipropellant Rocket (AMBR) engine, a 150-lbf Ir-Re chamber produced by Plasma Processes and Aerojet Rocketdyne, recently set a hydrazine specific impulse record of 333.5 seconds. To withstand the high loads during terrestrial launch, Re chambers with improved mechanical properties are needed. Recent electrochemical forming (EL-Form"TM") results have shown considerable promise for improving Re's mechanical properties by producing a multilayered deposit composed of a tailored microstructure (i.e., Engineered Re). The Engineered Re processing techniques were optimized, and detailed characterization and mechanical properties tests were performed. The most promising techniques were selected and used to produce an Engineered Re AMBR-sized combustion chamber for testing at Aerojet Rocketdyne.

  4. Practical wiring in SI units

    CERN Document Server

    Miller, Henry A

    2013-01-01

    Practical Wiring, Volume 1 is a 13-chapter book that first describes some of the common hand tools used in connection with sheathed wiring. Subsequent chapters discuss the safety in wiring, cables, conductor terminations, insulating sheathed wiring, conductor sizes, and consumer's control equipments. Other chapters center on socket outlets, plugs, lighting subcircuits, lighting accessories, bells, and primary and secondary cells. This book will be very valuable to students involved in this field of interest.

  5. Filling a Conical Cavity

    Science.gov (United States)

    Nye, Kyle; Eslam-Panah, Azar

    2016-11-01

    Root canal treatment involves the removal of infected tissue inside the tooth's canal system and filling the space with a dense sealing agent to prevent further infection. A good root canal treatment happens when the canals are filled homogeneously and tightly down to the root apex. Such a tooth is able to provide valuable service for an entire lifetime. However, there are some examples of poorly performed root canals where the anterior and posterior routes are not filled completely. Small packets of air can be trapped in narrow access cavities when restoring with resin composites. Such teeth can cause trouble even after many years and lead the conditions like acute bone infection or abscesses. In this study, the filling of dead-end conical cavities with various liquids is reported. The first case studies included conical cavity models with different angles and lengths to visualize the filling process. In this investigation, the rate and completeness at which a variety of liquids fill the cavity were observed to find ideal conditions for the process. Then, a 3D printed model of the scaled representation of a molar with prepared post spaces was used to simulate the root canal treatment. The results of this study can be used to gain a better understanding of the restoration for endodontically treated teeth.

  6. 3D Wire 2015

    DEFF Research Database (Denmark)

    Jordi, Moréton; F, Escribano; J. L., Farias

    This document is a general report on the implementation of gamification in 3D Wire 2015 event. As the second gamification experience in this event, we have delved deeply in the previous objectives (attracting public areas less frequented exhibition in previous years and enhance networking) and ha......, improves socialization and networking, improves media impact, improves fun factor and improves encouragement of the production team....

  7. One-wire thermocouple

    Science.gov (United States)

    Goodrich, W. D.; Staimach, C. J.

    1977-01-01

    Nickel alloy/constantan device accurately measures surface temperature at precise locations. Device is moderate in cost and simplifies fabrication of highly-instrumented seamless-surface heat-transfer models. Device also applies to metal surfaces if constantan wire has insulative coat.

  8. Detection chamber for search of low Mass WIMP and solar axions

    CERN Document Server

    Ovchinnikov, B M

    2016-01-01

    A chamber for direct detection of WIMPs with masses < 10 GeV/c2 and solar axions is developed. The chamber is filled with a gas mixture of H2 +3ppm TMAE (1,5,10 bar), or D2 + 3ppm TMAE. These gas fillings make it possible to suppress an electron background. For detection of events, the system GEM+pin-anode with a multiplication coefficient of about 10E+05 is constructed.

  9. Determination of the anode wire position by visible light in a new type straw for NA62 experiment tracker

    Science.gov (United States)

    Glonti, L.; Misheva, M.; Potrebenikov, Yu.; Samsonov, V.; Movchan, S.; Enik, T.; Kolesnikov, A.

    2016-07-01

    Microscope investigations of new-type thin-wall tubes (straws) produced for NA62 drift chambers revealed that they are semitransparent and allow anode wires to be observed under illumination by visible light. In this work it is shown that positions of wires in straws and thus the anode spacing in the drift chambers can be directly determined with a high accuracy ( 5-10 μm) using a microscope mounted on a high-precision optical bench. These data are important for decreasing errors during reconstruction of charged particle track coordinates in the drift chambers. The proposed technique is much simpler than the X-ray or radioactive source methods.

  10. Determination of the anode wire position by visible light in a new type straw for NA62 experiment tracker

    Energy Technology Data Exchange (ETDEWEB)

    Glonti, L., E-mail: glonti@sunse.jinr.ru; Misheva, M.; Potrebenikov, Yu.; Samsonov, V.; Movchan, S.; Enik, T.; Kolesnikov, A.

    2016-07-11

    Microscope investigations of new-type thin-wall tubes (straws) produced for NA62 drift chambers revealed that they are semitransparent and allow anode wires to be observed under illumination by visible light. In this work it is shown that positions of wires in straws and thus the anode spacing in the drift chambers can be directly determined with a high accuracy (~5–10 µm) using a microscope mounted on a high-precision optical bench. These data are important for decreasing errors during reconstruction of charged particle track coordinates in the drift chambers. The proposed technique is much simpler than the X-ray or radioactive source methods.

  11. Heavy liquid bubble chamber

    CERN Multimedia

    1965-01-01

    The CERN Heavy liquid bubble chamber being installed in the north experimental hall at the PS. On the left, the 1180 litre body; in the centre the magnet, which can produce a field of 26 800 gauss; on the right the expansion mechanism.

  12. OPAL Muon Chamber

    CERN Multimedia

    OPAL was one of the 4 experiments installed at the LEP particle accelerator from 1989 to 2000. This is a slice of the outermost layer of OPAL : the muon chambers. This outside layer detects particles which are not stopped by the previous layers. These are mostly muons.

  13. LEP Vacuum Chamber

    CERN Multimedia

    1983-01-01

    This is a cut-out of a LEP vacuum chamber for dipole magnets showing the beam channel and the pumping channel with the getter (NEG) strip and its insulating supports. A water pipe connected to the cooling channel can also be seen at the back.The lead radiation shield lining is also shown. See also 8305563X.

  14. Scanning bubble chamber pictures

    CERN Multimedia

    1974-01-01

    These were taken at the 2 m hydrogen bubble chamber. The photo shows an early Shiva system where the pre-measurements needed to qualify the event were done manually (cf photo 7408136X). The scanning tables were located in bld. 12. Gilberte Saulmier sits on foreground, Inge Arents at centre.

  15. Liquid Wall Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  16. LEP vacuum chamber, prototype

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    Final prototype for the LEP vacuum chamber, see 8305170 for more details. Here we see the strips of the NEG pump, providing "distributed pumping". The strips are made from a Zr-Ti-Fe alloy. By passing an electrical current, they were heated to 700 deg C.

  17. Secondary emission gas chamber

    CERN Document Server

    In'shakov, V; Skvortsov, V

    2014-01-01

    For a hadron calorimeter active element there is considered a gaseous secondary emis-sion detector (150 micron gap, 50 kV/cm). Such one-stage parallel plate chamber must be a radiation hard, fast and simple. A model of such detector has been produced, tested and some characteristics are presented.

  18. Mounting an ISR intersection chamber in the Split Field Magnet(SFM)

    CERN Multimedia

    1977-01-01

    The Split Field Magnet (SFM) was the largest spectrometer for particles from beam-beam collisions in the ISR. It could determine particle momenta in a large solid angle, but was designed mainly for the analysis of forward travelling particles.As the magnet was working on the ISR circulating beams, its magnetic field had to be such as to restore the correct proton orbit.The SFM, therefore, produced zero field at the crossing point and fields of opposite signs upstream and downstream of it and was completed by 2 large and 2 small compensator magnets. The gradient effects were corrected by magnetic channels equipped with movable flaps. The useful magnetic field volume was 28 m3, the induction in the median plane 1.14 T, the gap heigth 1.1 m, the length 10.5 m, the weight about 1000 ton.Concerning the detectors, the SFM was the first massive application of multiwire proportional chambers (about 70000 wires) which filled the main and the large compensator magnets. In the course of the years different types of vacu...

  19. Diffractive Photon Dissociation in a High Pressure Hydrogen Time Projection Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Snow, Gregory Roy [Rockefeller Univ., New York, NY (United States)

    1983-11-01

    We have performed an experiment at the Tagged Photon Facility of Fermilab to study the diffraction dissociation of high energy photons on hydrogen y + p -+ x + p in the region 0.02 < $\\mid t \\mid$ < 0.1 $(GeV/c)^2$, $M_x$ $^2/s$ < 0.1. In this process, incident photons whose energies range from 70 to 140 GeV transform coherently to massive hadronic states in the mass range M < 5 GeV/c 2 • x We measure the inclusive differential cross section$\\frac{d^20}{dt dM_x ^2}$) The behavior of this cross section, especially when compared to the corresponding cross sections for the diffraction dissociation of incident hadrons (pions, kaons, and protons), reveals some fundamental characteristics of photon hadronic interactions. We use the Recoil Technique to determine the missing mass, $M_x$, and the square of the 4-momentum transfer, t. The recoil detector, TREAD, is a cylindrical time projection chamber filled with high pressure hydrogen gas which serves both as the target and as the drift medium for the ionization track created by recoil protons. The ionization drifts up to 75 cm in a high axial electric field. Concentric sense wires mounted on endplates sample different parts of the track, yielding the polar angle of the recoil. The energy of the recoil is determined by stopping the proton in scintillation counters located inside the high pressure vessel....

  20. Drift chamber readout with 1 Gsample/s full signal digitization

    CERN Document Server

    Cerrito, L; Imhof, M; Paoluzi, L; Santovetti, E; Weseler, S

    1999-01-01

    This paper describes the performances of a large volume drift chamber with complete digitization of the output pulses. The electronics used in this test include wide-band (700 MHz) amplifiers and fast (1 Gsample/s) digitizers. The gas mixture selected for drift chamber operation (80% He-20% CH sub 4) and the signal processing mentioned above allow the measurement of the primary ionization clusters. The improvement in the (wire) impact parameter evaluation of the primary particle is sizeable.

  1. Sag Compensation System for Assembly of MDT-Chambers for the ATLAS Experiment

    CERN Document Server

    Barashkou, A V; Chepurnov, V F; Evtoukhovitch, P G; Glonti, G L; Gongadze, A L; Ilyushenka, Y N; Kotov, S A; Kruchonak, V G; Tskhadadze, E G

    2005-01-01

    The description of a system of the devices created for compensation of the gravitational deflection of the drift chamber during its assembly is presented. By means of this system during stage-by-stage gluing of layers of tube drift detectors to the chamber the transversal deflection considerably decreases and by that high accuracy of mutual position of separate tubes is provided. The devices were applied at assembly of 74 MDT-chambers of the ATLAS experiment. Design values of deformation of the chambers as well as the results of measurement of transversal deflections obtained during the assembly with the use of the system of sag compensation are given. Testing of chambers on the X-ray tomograph at CERN has shown that the accuracy of the positions of separate signal wires inside the assembled chambers is within the limits of the required 20 $\\mu$m.

  2. Analytical form of current-voltage characteristic of cylindrical and spherical ionization chambers

    CERN Document Server

    Stoyanov, Dimitar G

    2007-01-01

    The basic processes of ionization and recombination of gas-filled ionization chamber are presented in this article. A differential equation describing the distribution of current densities in the volume of the ionization chamber is obtained from the balance of the particles and charges densities. As a result of the differential equation solving an analytical form of the current-voltage characteristic of cylindrical and spherical ionization chambers is got.

  3. Study of the response of low pressure ionization chambers

    CERN Document Server

    Nebot Del Busto, E; Effinger, E; Grishin, V; Herranz Alvarez, J

    2012-01-01

    The Beam Loss Monitoring System (BLM) of the Large Hadron Collider (LHC) is based on parallel plate Ionization Chambers (IC) with active volume 1.5l and a nitrogen filling gas at 0.1 bar overpressure. At the largest loss locations, the ICs generate signals large enough to saturate the read-out electronics. A reduction of the active volume and filling pressure in the ICs would decrease the amount of charge collected in the electrodes, and so provide a higher saturation limit using the same electronics. This makes Little Ionization Chambers (LIC) with both reduced pressure and small active volume a good candidate for these high radiation areas. In this contribution we present measurements performed with several LIC monitors with reduced active volume and various filling pressures. These detectors were tested under various conditions with different beam setups, with standard LHC ICs used for calibration purposes

  4. Structural evolution of a Ta-filament during hot-wire chemical vapour deposition of Silicon investigated by electron backscatter diffraction

    CSIR Research Space (South Africa)

    Oliphant, CJ

    2012-03-01

    Full Text Available In this study we investigate the structural changes of a burnt-out tantalum filament that was operated at typical hydrogenated nanocrystalline silicon synthesis conditions in our hot-wire chemical vapour deposition chamber. Scanning electron...

  5. Tensile test and interface retention forces between wires and composites in lingual fixed retainers.

    Science.gov (United States)

    Paolone, Maria Giacinta; Kaitsas, Roberto; Obach, Patricia; Kaitsas, Vasilios; Benedicenti, Stefano; Sorrenti, Eugenio; Barberi, Fabrizio

    2015-06-01

    In daily orthodontic clinical practice retention is very important, and lingual retainers are part of this challenge. The failure of lingual retainers may be due to many factors. The aim of this study was to assess the retention forces and mechanical behavior of different types of wires matched with different kinds of composites in lingual retainers. A tensile test was performed on cylindrical composite test specimens bonded to orthodontic wires. The specimens were constructed using four different wires: a straight wire (Remanium .016×.022″ Dentaurum), two round twisted wires (Penta One .0215″ Masel, Gold Penta Twisted .0215″ Gold N'braces) and a rectangular braided wire (D-Rect .016×.022″ Ormco); and three composites: two micro-hybrids (Micro-Hybrid Enamel Plus HFO Micerium, and Micro-Hybrid SDR U Dentsply) and a micro-nano-filled composite (Micro-Nano-Filled Transbond LR 3M). The test was performed at a speed of 10mm/min on an Inström device. The wire was fixed with a clamp. The results showed that the bonding between wires and composites in lingual fixed retainers seemed to be lowest for rectangular smooth wires and increased in round twisted and rectangular twisted wires where the bonding was so strong that the maximum tension/bond strength was greater than the ultimate tensile strength of the wire. The highest values were in rectangular twisted wires. Concerning the composites, hybrid composites had the lowest interface bonding values and broke very quickly, while the nano- and micro-composites tolerated stronger forces and displayed higher bonding values. The best results were observed with the golden twisted wire and reached 21.46 MPa with the Transbond composite. With the rectangular braided wire the retention forces were so high that the Enamel Plus composite fractured when the load exceeded 154.6 N/MPa. When the same wire was combined with the Transbond LR either the wire or the composite broke when the force exceeded 240 N. The results of this

  6. Wired to freedom

    DEFF Research Database (Denmark)

    Jepsen, Kim Sune Karrasch; Bertilsson, Margareta

    2017-01-01

    of cochlear implantations among Danish users in order to shed more light on their social and political implications. We situate cochlear implantation in a framework of new life science advances, politics, and user experiences. Analytically, we draw upon the notion of social imaginary and explore the social...... dimension of life science through a notion of public politics adopted from the political theory of John Dewey. We show how cochlear implantation engages different social imaginaries on the collective and individual levels and we suggest that users share an imaginary of being “wired to freedom” that involves...... new access to social life, continuous communicative challenges, common practices, and experiences. In looking at their lives as “wired to freedom,” we hope to promote a wider spectrum of civic participation in the benefit of future life science developments within and beyond the field of Cochlear...

  7. From Wires to Cosmology

    CERN Document Server

    Amin, Mustafa A

    2015-01-01

    We provide a statistical framework for characterizing stochastic particle production in the early universe via a precise correspondence to current conduction in wires with impurities. Our approach is particularly useful when the microphysics is uncertain and the dynamics are complex, but only coarse-grained information is of interest. We study scenarios with multiple interacting fields and derive the evolution of the particle occupation numbers from a Fokker-Planck equation. At late times, the typical occupation numbers grow exponentially which is the analog of Anderson localization for disordered wires. Some statistical features of the occupation numbers show hints of universality in the limit of a large number of interactions and/or a large number of fields. For test cases, excellent agreement is found between our analytic results and numerical simulations.

  8. Construction and cosmic-ray test of the new inner drift chamber for BESIII

    Science.gov (United States)

    Xie, Yong-ji; Qin, Zhong-hua; Ma, Xiao-yan; Zhang, Jian; Wu, Ling-hui; Xie, Wan; Dong, Ming-yi; Dong, Jing; Ji, Xiao-lu; Jiang, Xiao-shan; Ou-yang, Qun; Zhu, Ke-jun; Chen, Yuan-bo

    2016-09-01

    A new inner drift chamber has been built which can replace the aged part of the BESIII drift chamber when needed. The design of the new inner drift chamber can minimize the ineffective area in the very forward and backward region and hence reduce the background event rate. With this design, the new inner drift chamber is expected to have a longer lifetime and improved performance due to the lower occupancy. The endplates and the cylinder were machined with high precision. Wire stringing was performed after the mechanical structure was assembled, and good quality of wire stringing was ensured by measurement of the tension and leakage current of the wires. After completion of the physical construction of the new chamber, a cosmic-ray test was carried out to test its performance. The results of the cosmic-ray test show that the new inner chamber achieves a spatial resolution of 127 μm and a dE/dx resolution of 6.4%, which satisfies the design specifications.

  9. Polyurethane spray coating of aluminum wire bonds to prevent corrosion and suppress resonant oscillations

    CERN Document Server

    INSPIRE-00092738; Kurth, Matthew; Boyd, Rusty

    2016-01-01

    Unencapsulated aluminum wedge wire bonds are common in particle physics pixel and strip detectors. Industry-favored bulk encapsulation is eschewed due to the range of operating temperatures and radiation. Wire bond failures are a persistent source of tracking-detector failure. Unencapsulated bonds are vulnerable to condensation-induced corrosion, particularly when halides are present. Oscillations from periodic Lorentz forces are documented as another source of wire bond failure. Spray application of polyurethane coatings, performance of polyurethane-coated wire bonds after climate chamber exposure, and resonant properties of polyurethane-coated wire bonds and their resistance to periodic Lorentz forces are under study for use in a future High Luminosity Large Hadron Collider detector such as the ATLAS Inner Tracker upgrade.

  10. Twisting wire scanner

    CERN Document Server

    Gharibyan, V; Krouptchenkov, I; Nölle, D; Tiessen, H; Werner, M; Wittenburg, K

    2012-01-01

    A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors is presented.

  11. Magnetoconductance of quantum wires

    Science.gov (United States)

    Ferreira, Gerson J.; Sammarco, Filipe; Egues, Carlos

    2010-03-01

    At low temperatures the conductance of a quantum wires exhibit characteristic plate-aus due to the quantization of the transverse modes [1]. In the presence of high in-plane magnetic fields these spin-split transverse modes cross. Recently, these crossings were observed experimentally [2] via measurements of the differential conductance as a function of the gate voltage and the in-plane magnetic-field. These show structures described as either anti-crossings or magnetic phase transitions. Motivated by our previous works on magnetotransport in 2DEGs via the Spin Density Functional Theory (SDFT) [3], here we propose a similar model to investigate the magnetoconductance of quantum wires. We use (i) the SDFT via the Kohn-Sham self-consistent scheme within the local spin density approximation to obtain the electronic structure and (ii) the Landauer-Buettiker formalism to calculate the conductance of a quantum wire. Our results show qualitative agreement with the data of Ref. [2]. [1] B. J. van Wees et al., Phys. Rev. Lett. 60, 848 (1988). [2] A. C. Graham et al., Phys. Rev. Lett. 100, 226804 (2008). [3] H. J. P. Freire, and J. C. Egues, Phys. Rev. Lett. 99, 026801 (2007); G. J. Ferreira, and J. Carlos Egues, J. Supercond. Nov. Mag., in press; G. J. Ferreira, H. J. P. Freire, J. Carlos Egues, submitted.

  12. Radiation Hydrodynamic Parameter Study of Inertial Fusion Energy Reactor Chambers

    Science.gov (United States)

    Sacks, Ryan; Moses, Gregory

    2014-10-01

    Inertial fusion energy reactors present great promise for the future as they are capable of providing baseline power with no carbon footprint. Simulation work regarding the chamber response and first wall insult is performed with the 1-D radiation hydrodynamics code BUCKY. Simulation with differing chamber parameters are implemented to study the effect of gas fill, gas mixtures and chamber radii. Xenon and argon gases are of particular interest as shielding for the first wall due to their high opacity values and ready availability. Mixing of the two gases is an attempt to engineer a gas cocktail to provide the maximum amount of shielding with the least amount of cost. A parameter study of different chamber radii shows a consistent relationship with that of first wall temperature (~1/r2) and overpressure (~1/r3). This work is performed under collaboration with Lawrence Livermore National Laboratory.

  13. Dual wire welding torch and method

    Science.gov (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  14. Nanopowder production by gas-embedded electrical explosion of wire

    Institute of Scientific and Technical Information of China (English)

    Zou Xiao-Bing; Mao Zhi-Guo; Wang Xin-Xin; Jiang Wei-Hua

    2013-01-01

    A small electrical explosion of wire (EEW) setup for nanopowder production is constructed.It consists of a low inductance capacitor bank of 2 μF--4 μF typically charged to 8 kV-30 kV,a triggered gas switch,and a production chamber housing the exploding wire load and ambient gas.With the EEW device,nanosize powders of titanium oxides,titanium nitrides,copper oxides,and zinc oxides are successfully synthesized.The average particle size of synthesized powders under different experimental conditions is in a range of 20 nm-80 nm.The pressure of ambient gas or wire vapor can strongly affect the average particle size.The lower the pressure,the smaller the particle size is.For wire material with relatively high resistivity,such as titanium,whose deposited energy Wd is often less than sublimation energy Ws due to the flashover breakdown along the wire prematurely ending the Joule heating process,the synthesized particle size of titanium oxides or titanium nitrides increases with overheat coefficient k (k =Wd/Ws) increasing.

  15. Anechoic Radio Frequency Test Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — This chamber is used for characterization test of such systems as communications gear, tanks, radar, missiles, and helicopters. The dimensions of the chamber are 114...

  16. Metering Wheel-Wire Track Wire Boom Deployment Mechanism

    Science.gov (United States)

    Granoff, Mark S.

    2014-01-01

    The NASA MMS Spin Plane Double Probe (SDP) Deployer utilizes a helical path, rotating Metering Wheel and a spring loaded Wire "Holding" Track to pay out a "fixed end" 57 meter x 1.5 mm diameter Wire Boom stored between concentric storage cylinders. Unlike rotating spool type storage devices, the storage cylinders remain stationary, and the boom wire is uncoiled along the length of the cylinder via the rotation of the Metering Wheel. This uncoiling action avoids the need for slip-ring contacts since the ends of the wire can remain stationary. Conventional fixed electrical connectors (Micro-D type) are used to terminate to operational electronics.

  17. A new construction technique of high granularity and high transparency drift chambers for modern high energy physics experiments

    Science.gov (United States)

    Chiarello, G.; Chiri, C.; Corvaglia, A.; Grancagnolo, F.; Miccoli, A.; Panareo, M.; Pepino, A.; Pinto, C.; Primiceri, P.; Spedicato, M.; Tassielli, G. F.

    2016-07-01

    Modern experiments for the search of extremely rare processes require high resolutions (order of 50-200 keV/c) tracking systems for particle momenta in the range of 50-300 MeV/c, dominated by multiple scattering contributions. We will present a newly developed construction technique for ultra-low mass Drift Chambers fulfilling this goal. It consists of (1) a semiautomatic wiring machine with a high degree of control over wire mechanical tensioning (better than 0.2 g) and over wire positioning (of the order of 20 μm) for simultaneous wiring of multi-wire layers; (2) a contact-less IR laser soldering tool designed for a feed-through-less wire anchoring system; (3) an automatic handling system for storing and transporting the multi-wire layers to be placed over the drift chamber end-plates. These techniques have been successfully implemented at INFN-Lecce and University of Salento and are currently being used for the construction of Drift Chamber of the MEG (μ → eγ) upgrade experiment.

  18. THERMAL CONDUCTIVITY OF METALLIC WIRES

    Institute of Scientific and Technical Information of China (English)

    LU XIANG; GU JI-HUA; CHU JUN-HAO

    2001-01-01

    The effect of radial thickness on the thermal conductivity of a free standing wire is investigated. The thermal conductivity is evaluated using the Boltzmann equation. A simple expression for the reduction in conductivity due to the increase of boundary scattering is presented. A comparison is made between the experimental results of indium wires and the theoretical calculations. It is shown that this decrease of conductivity in wires is smaller than that in film where heat flux is perpendicular to the surface.

  19. Position reconstruction in drift chambers operated with Xe, $CO_{2}$ (15\\%)

    CERN Document Server

    Adler, C; Appelshäuser, H; Bielcikova, J; Blume, C; Braun-Munzinger, P; Bucher, D; Busch, O; Catanescu, V; Ciobanu, M; Daues, H W; Emschermann, D; Fateev, O V; Foka, P; Garabatos, C; Gunji, T; Herrmann, N; Inuzuka, M; Ivanov, M; Kislov, E; Lindenstruth, V; Lippmann, C; Ludolphs, W; Mahmoud, T; Petracek, V; Petrovici, M; Radomski, S; Rusanov, I; Sandoval, A; Santo, R; Schicker, R; Schwarz, K; Simon, R S; Smykov, L P; Soltveit, H K; Stachel, J; Stelzer, H; Tsiledakis, G; Vulpescu, B; Wessels, J P; Windelband, B; Yurevich, V; Zanevsky, Yu; Zaudtke, O

    2005-01-01

    We present measurements of position and angular resolution of drift chambers operated with a Xe, CO2 (15%) mixture. The results are compared to Monte Carlo simulations and important systematic effects - in particular the dispersive nature of the absorption of transition radiation and non-linearities - are discussed. The measurements were carried out with prototype drift chambers of the ALICE Transition Radiation Detector, but our findings can be generalized to other drift chambers with similar geometry, where the electron drift is perpendicular to the wire planes.

  20. Vacuum Chambers for LEP sections

    CERN Multimedia

    1983-01-01

    The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

  1. Multi-anode ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, Aleksey E. (South Setauket, NY); Smith, Graham (Port Jefferson, NY); Mahler, George J. (Rocky Point, NY); Vanier, Peter E. (Setauket, NY)

    2010-12-28

    The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

  2. Subminiature Hot-Wire Probes

    Science.gov (United States)

    Westphal, R. V.; Lemos, F. R.; Ligrani, P. M.

    1989-01-01

    Class of improved subminiature hot-wire flow-measuring probes developed. Smaller sizes yield improved resolution in measurements of practical aerodynamic flows. Probe made in one-wire, two-perpendicular-wire, and three-perpendicular-wire version for measurement of one, two, or all three components of flow. Oriented and positioned on micromanipulator stage and viewed under microscope during fabrication. Tested by taking measurements in constant-pressure turbulent boundary layer. New probes give improved measurements of turbulence quantities near surfaces and anisotropies of flows strongly influence relative errors caused by phenomena related to spatial resolution.

  3. Plasma Formation Around Single Wires

    Science.gov (United States)

    Duselis, Peter U.; Kusse, Bruce R.

    2002-12-01

    At Cornell's Laboratory of Plasma Studies, single wires of various metals were exploded using a ˜250 ns pulser with a rise time of ˜20 A/ns. It was found that the wires first experience a resistive heating phase that lasts 50-80 ns before a rapid collapse of voltage. From that point on, the voltage across the wire was negligible while the current through the wire continued to increase. We attribute this voltage collapse to the formation of plasma about the wire. Further confirmation of this explanation will be presented along with new experimental data describing preliminary spectroscopy results, the expansion rate of the plasma, and current flow along the wire as a function of radius. The resistance of the wire-electrode connection will be shown to significantly affect the energy deposition. Various diagnostics were used to obtain these experiments. Ultraviolet sensitive vacuum photodiodes and a framing camera with an 8 ns shutter were used to detect and measure the width of the visible light emitted by the plasma. A special wire holder was constructed that allowed the transfer of current from the wire to the surrounding plasma to be observed.

  4. Texture development in Galfenol wire

    Science.gov (United States)

    Boesenberg, A. J.; Restorff, J. B.; Wun-Fogle, M.; Sailsbury, H.; Summers, E.

    2013-05-01

    Galfenol (Fe-Ga alloy) wire fabrication provides a low cost alternative to directional solidification methods. This work evaluates the compositional dependence of the wire drawing suitability of Fe-Ga and characterizes the microstructural and magnetic properties of these wires. Wire has been produced with Ga contents between 10 at. % and 17 at. % to allow determination of the ductile to brittle transition (DTBT) in wire manufacture. Published results on chill cast bend specimens indicated that a DTBT occurs at roughly 15 at. % Ga. This DTBT was observed under tensile loading with a corresponding change in fracture behavior from transverse fracture to intergranular fracture. For improved magnetostrictive performance, higher Ga contents are desired, closer to the 17 at. % Ga evaluated in this work. Electron backscattered diffraction B-H loop and resonance measurements as a function of magnetic field (to determine modulus and coupling factor) are presented for as-drawn, furnace, and direct current (DC) annealed wire. Galfenol wire produced via traditional drawing methods is found to have a strong (α) texture parallel to the drawing direction. As-drawn wire was observed to have a lower magnetic permeability and larger hysteresis than DC annealed wire. This is attributed to the presence of a large volume of crystalline defects; such as vacancies and dislocations.

  5. Microstructure Filled Hohlraums

    Energy Technology Data Exchange (ETDEWEB)

    Moore, A. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thomas, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reese, T. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-24

    We propose replacing the gas fill in a hohlraum with a low average density, variable uniformity 3D printed structure. This creates a bimodal hohlraum which acts like a vacuum hohlraum initially during the picket, but could protect the capsule from glint or direct illumination, and then once expanded, homogenizes to behave like a variable z gas-fill during peak portion of the drive. This is motivated by a two main aims: 1) reduction of the Au bubble velocity to improve inner beam propagation, and 2) the introduction of a low density, high-Z, x-ray converter to improve x-ray production in the hohlraum and uniformity of the radiation field seen by the capsule.

  6. Wiring regulations in brief

    CERN Document Server

    Tricker, Ray

    2012-01-01

    Tired of trawling through the Wiring Regs?Perplexed by Part P?Confused by cables, conductors and circuits?Then look no further! This handy guide provides an on-the-job reference source for Electricians, Designers, Service Engineers, Inspectors, Builders, Students, DIY enthusiastsTopic-based chapters link areas of working practice - such as cables, installations, testing and inspection, special locations - with the specifics of the Regulations themselves. This allows quick and easy identification of the official requirements relating to the situati

  7. Complications of Dermal Filling

    Directory of Open Access Journals (Sweden)

    Sajad Ahmad Salati

    2011-11-01

    Full Text Available Dermal fillers have globally become sought after drugs due to the desire of aging population to regain the youthful looks without any surgical operations. But like other procedures, dermal filling can become complicated. Besides the profitability have introduced the factor of malpractice which can bring in misery rather than beauty and youthful body contours. This article briefly reviews the common adverse effects of dermal fillers.

  8. Construction and test of new precision drift-tube chambers for the ATLAS muon spectrometer

    Science.gov (United States)

    Kroha, H.; Kortner, O.; Schmidt-Sommerfeld, K.; Takasugi, E.

    2017-02-01

    ATLAS muon detector upgrades aim for increased acceptance for muon triggering and precision tracking and for improved rate capability of the muon chambers in the high-background regions of the detector with increasing LHC luminosity. The small-diameter Muon Drift Tube (sMDT) chambers have been developed for these purposes. With half of the drift-tube diameter of the MDT chambers and otherwise unchanged operating parameters, sMDT chambers share the advantages of the MDTs, but have an order of magnitude higher rate capability and can be installed in detector regions where MDT chambers do not fit in. The chamber assembly methods have been optimized for mass production, minimizing construction time and personnel. Sense wire positioning accuracies of 5 μm have been achieved in serial production for large-size chambers comprising several hundred drift tubes. The construction of new sMDT chambers for installation in the 2016/17 winter shutdown of the LHC and the design of sMDT chambers in combination with new RPC trigger chambers for replacement of the inner layer of the barrel muon spectrometer are in progress.

  9. Influence of counting chamber type on CASA outcomes of equine semen analysis.

    Science.gov (United States)

    Hoogewijs, M K; de Vliegher, S P; Govaere, J L; de Schauwer, C; de Kruif, A; van Soom, A

    2012-09-01

    Sperm motility is considered to be one of the key features of semen analysis. Assessment of motility is frequently performed using computer-assisted sperm analysis (CASA). Nevertheless, no uniform standards are present to analyse a semen sample using CASA. We hypothesised that the type of counting chamber used might influence the results of analysis and aimed to study the effect of chamber type on estimated concentration and motility of an equine semen sample assessed using CASA. Commonly used disposable Leja chambers of different depths were compared with disposable and reusable ISAS chambers, a Makler chamber and a World Health Organization (WHO) motility slide. Motility parameters and concentrations obtained with CASA using these different chambers were analysed. The NucleoCounter was used as gold standard for determining concentration. Concentration and motility parameters were significantly influenced by the chamber type used. Using the NucleoCounter as the gold standard for determining concentration, the correlation coefficients were low for all of the various chambers evaluated, with the exception of the 12 µm deep Leja chamber. Filling a chamber by capillary forces resulted in a lower observed concentration and reduced motility parameters. All chambers evaluated in this study resulted in significant lower progressive motility than the WHO prepared slide, with the exception of the Makler chamber, which resulted in a slight, but statistically significant, increase in progressive motility estimates. Computer-assisted sperm analysis can only provide a rough estimate of sperm concentration and overestimation is likely when drop-filled slides with a coverslip are used. Motility estimates using CASA are highly influenced by the counting chamber; therefore, a complete description of the chamber type used should be provided in semen reports and in scientific articles. © 2011 EVJ Ltd.

  10. The APS ceramic chambers

    Energy Technology Data Exchange (ETDEWEB)

    Milton, S.; Warner, D.

    1994-07-01

    Ceramics chambers are used in the Advanced Photon Source (APS) machines at the locations of the pulsed kicker and bumper magnets. The ceramic will be coated internally with a resistive paste. The resistance is chosen to allow the low frequency pulsed magnet field to penetrate but not the high frequency components of the circulating beam. Another design goal was to keep the power density experienced by the resistive coating to a minimum. These ceramics, their associated hardware, the coating process, and our recent experiences with them are described.

  11. Corrosion of Wires on Wooden Wire-Bound Packaging Crates

    Science.gov (United States)

    Samuel L. Zelinka; Stan Lebow

    2015-01-01

    Wire-bound packaging crates are used by the US Army to transport materials. Because these crates may be exposed to harsh environments, they are dip-treated with a wood preservative (biocide treatment). For many years, zinc-naphthenate was the most commonly used preservative for these packaging crates and few corrosion problems with the wires were observed. Recently,...

  12. Construction and commissioning of a position-sensitive ionization chamber

    Science.gov (United States)

    Kwag, M. S.; Chae, K. Y.; Cha, S. M.; Kim, A.; Kim, M. J.; Lee, E. J.; Lee, J. H.

    2016-05-01

    A position-sensitive ionization chamber has been constructed and commissioned at the Physics Department of Sungkyunkwan University to extract position information on incident charged particles for future nuclear reaction measurements. By utilizing the newly-designed position-sensitive anodes and the previously-commissioned portable gas-filled ionization chamber by Chae et al., position information on incident particles could be obtained. The device was tested with an 241Am α-emitting source, and the standard deviation of the fitted Gaussian distribution was measured to be 1.76 mm when a collimator with a 2 mm hole was used.

  13. Damping insert materials for settling chambers of supersonic wind tunnels

    Science.gov (United States)

    Wu, Jie; Radespiel, Rolf

    2017-03-01

    This study describes the application of a novel damping insert material for reducing the flow fluctuations in a tandem nozzle supersonic wind tunnel. This new damping material is composed of multi-layer stainless steel wired meshes. The influences of the multi-layer mesh, such as the quantity of the mesh layer and the installed location in the settling chamber, to the freestream quality have been investigated. A Pitot probe instrumented with a Kulite pressure sensor and a hot-wire probe are employed to monitor the flow fluctuation in the test section of the wind tunnel. Thereafter, a combined modal analysis is applied for the disturbance qualification. Additionally, the transient Mach number in the test section is measured. The disturbance qualification indicates that the multi-layer mesh performs well in providing reduction of vorticity reduction and acoustic fluctuations. Comparable flow quality of the freestream was also obtained using a combination of flexible damping materials. However, the life-span of the new damping materials is much longer. The time transient of the Mach number measured in the test section indicates that the mean flow is rather constant over run time. Furthermore, the time-averaged pressure along the settling chamber is recorded and it shows the distribution of pressure drop by settling chamber inserts.

  14. A novel carbon fiber bundle microelectrode and modified brain slice chamber for recording long-term multiunit activity from brain slices.

    Science.gov (United States)

    Tcheng, T K; Gillette, M U

    1996-11-01

    The fabrication and characteristics of a novel multiunit recording electrode and modified brain slice chamber suitable for long-term recording from brain slices are described. The electrode consisted of an electrolyte-filled glass micropipette with a 20-50 microns thick wax-coated bundle of 5-micron diameter carbon fibers extending 2.5 cm from the tapered end and an AgCl-coated silver wire inserted into the open end and connected to a preamplifier. Both ends of the electrode were sealed with wax to prevent evaporation of the electrolyte. The brain slice was maintained over this extended period in an interface-type brain slice chamber modified to completely surround the slice with medium. Using this electrode, regular 24-h oscillations of spontaneous multiunit activity were recorded for 3 days from a single location in a 500 microns thick rat suprachiasmatic nucleus brain slice. Preliminary data suggest that this novel carbon fiber bundle electrode will be a favorable alternative to traditional metal electrodes for long-term recording of multiunit activity from brain slices.

  15. Council Chamber exhibition

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    To complete the revamp of CERN’s Council Chamber, a new exhibition is being installed just in time for the June Council meetings.   Panels will showcase highlights of CERN’s history, using some of the content prepared for the exhibitions marking 50 years of the PS, which were displayed in the main building last November. The previous photo exhibition in the Council Chamber stopped at the 1970s. To avoid the new panels becoming quickly out of date, photos are grouped together around specific infrastructures, rather than following a classic time-line. “We have put the focus on the accelerators – the world-class facilities that CERN has been offering researchers over the years, from the well-known large colliders to the lesser-known smaller facilities,” says Emma Sanders, who worked on the content. The new exhibition will be featured in a future issue of the Bulletin with photos and an interview with Fabienne Marcastel, designer of the exhibit...

  16. Study of the Internal Alignment of the CMS Muon Barrel Drift Chambers Using Cosmic Ray Tracks

    CERN Document Server

    Benettoni, Massimo; Conti, Enrico; Dosselli, Umberto; Gasparini, Fabrizio; Gasparini, Ugo; Gonella, Franco; Lacaprara, Stefano; Lippi, Ivano; Meneguzzo, Anna Teresa; Passaseo, Marina; Pegoraro, Matteo; Ronchese, Paolo; Vanini, Sara; Torassa, Ezio; Ventura, Sandro; Zanetti, Marco; Zotto, Pierluigi; Zumerle, Gianni; Gulmini, Michele; Maron, Gaetano; Toniolo, Nicola

    2004-01-01

    This note describes the alignment studies performed on 21 Muon Barrel Drift Tube chambers for the CMS experiment, assembled in the INFN production center at the Legnaro National Laboratories. Data were collected using the cosmic ray test facility which was setup in Legnaro to test the chamber behaviour before being moved to CERN. An alignment procedure using cosmic ray tracks has been developed, allowing a measurement of the internal misalignment of the wire layers inside a chamber "superlayer" (SL) and of the relative misalignment of the 2 SL's in the r-phi bending plane. The analysis shows that the wire layers are positioned with an rms precision of about 45 micron; the relative positioning of the 2 SL's in the r-phi bending plane is meausured to have a distribution with ~ 50 micron average value and 200 micron rms.

  17. BEPC II wire scanner system

    Institute of Scientific and Technical Information of China (English)

    SUI Yan-Feng; WANG Lin; ZHAO Ying; YUE Jun-Hui; LI Xiao-Ping; CAO Jian-She; MA Li

    2010-01-01

    To monitor the beam profile at the end of the linac non-destructively,a wire scanner as a new diagnostic instrument was designed,manufactured and installed in 2007.Since then,several measurements have been carried out using this device.This paper describes the whole system of the wire scanner and the testing results.

  18. Wire and Packing Tape Sandwiches

    Science.gov (United States)

    Rabinowitz, Sandy

    2009-01-01

    In this article, the author describes how students can combine craft wire with clear packing tape to create a two-dimensional design that can be bent and twisted to create a three-dimensional form. Students sandwich wire designs between two layers of tape. (Contains 1 online resource.)

  19. Wire metamaterials: physics and applications.

    Science.gov (United States)

    Simovski, Constantin R; Belov, Pavel A; Atrashchenko, Alexander V; Kivshar, Yuri S

    2012-08-16

    The physics and applications of a broad class of artificial electromagnetic materials composed of lattices of aligned metal rods embedded in a dielectric matrix are reviewed. Such structures are here termed wire metamaterials. They appear in various settings and can operate from microwaves to THz and optical frequencies. An important group of these metamaterials is a wire medium possessing extreme optical anisotropy. The study of wire metamaterials has a long history, however, most of their important and useful properties have been revealed and understood only recently, especially in the THz and optical frequency ranges where the wire media correspond to the lattices of microwires and nanowires, respectively. Another group of wire metamaterials are arrays and lattices of nanorods of noble metals whose unusual properties are driven by plasmonic resonances. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. FIRAS wire grid characterization techniques

    Science.gov (United States)

    Barney, Richard D.; Magner, Thomas J.

    1989-01-01

    Characterization techniques used to verify the quality and spectral performance of the large freestanding wire grid polarizing beamsplitters and input/output polarizers used in the Far Infrared Absolute Spectrophotometer (FIRAS) are presented. The clear aperture of these grids is lined with 20.8 micron diameter gold coated tungsten wire, spaced 33 microns apart. The grid characteristics measured throughout fabrication and space flight qualification are the center to center wire spacing and wire plane flatness. Ideally, the wire grids should produce coherent wavefronts with equal reflectance and transmittance properties. When the spacing is inconsistent, these wavefront intensities are unequal, thus decreasing the efficiency of the grids and reducing the output signal of the FIRAS. The magnitude of the output interferogram is also reduced by incoherence in the interfering wave fronts caused by uneven flatness.

  1. Construction and Test of New Precision Drift-Tube Chambers for Upgrades of the ATLAS Muon Spectrometer in 2016/17

    CERN Document Server

    INSPIRE-00218480; Kortner, O.; Müller, F.; Nowak, S.; Schmidt-Sommerfeld, K.

    2016-01-01

    Small-diameter Muon Drift Tube (sMDT) chambers have been developed for the ATLAS muon detector upgrade. They possess an improved rate capability and a more compact design with respect to the existing chambers, which allows to equip detector regions uninstrument at present. The chamber assembly methods have been optimized for mass production, while the sense wire positioning accuracy is improved to below ten microns. The chambers will be ready for installation in the winter shutdown 2016/17 of the Large Hadron Collider. The design and construction of the new sMDT chambers for ATLAS will be discussed as well as measurements of their precision and performance.

  2. Construction and test of high precision drift-tube (sMDT) chambers for the ATLAS muon spectrometer

    CERN Document Server

    Nowak, Sebastian; Kroha, Hubert; Schwegler, Philipp; Sforza, Federico

    2014-01-01

    For the upgrade of the ATLAS muon spectrometer in March 2014 new muon tracking chambers (sMDT) with drift-tubes of 15 mm diameter, half of the value of the standard ATLAS Monitored Drift-Tubes (MDT) chambers, and 10~$\\mu$m positioning accuracy of the sense wires have been constructed. The new chambers are designed to be fully compatible with the present ATLAS services but, with respect to the previously installed ATLAS MDT chambers, they are assembled in a more compact geometry and they deploy two additional tube layers that provide redundant rack information. The chambers are composed of 8 layers of in total 624 aluminium drift-tubes. The assembly of a chamber is completed within a week. A semi-automatized production line is used for the assembly of the drift-tubes prior to the chamber assembly. The production procedures and the quality control tests of the single components and of the complete chambers will be discussed. The wire position in the completed chambers have been measured by using a coordinate me...

  3. Mush Column Magma Chambers

    Science.gov (United States)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  4. Nano-storage wires.

    Science.gov (United States)

    Lee, Dong Jun; Kim, Eunji; Kim, Daesan; Park, Juhun; Hong, Seunghun

    2013-08-27

    We report the development of "nano-storage wires" (NSWs), which can store chemical species and release them at a desired moment via external electrical stimuli. Here, using the electrodeposition process through an anodized aluminum oxide template, we fabricated multisegmented nanowires composed of a polypyrrole segment containing adenosine triphosphate (ATP) molecules, a ferromagnetic nickel segment, and a conductive gold segment. Upon the application of a negative bias voltage, the NSWs released ATP molecules for the control of motor protein activities. Furthermore, NSWs can be printed onto various substrates including flexible or three-dimensional structured substrates by direct writing or magnetic manipulation strategies to build versatile chemical storage devices. Since our strategy provides a means to store and release chemical species in a controlled manner, it should open up various applications such as drug delivery systems and biochips for the controlled release of chemicals.

  5. The ALICE time projection chamber

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    This time projection chamber is part of the ALICE detector on the new LHC accelerator at CERN. Particles produced in collisions at the core of the detector will follow paths outward through the various sub-detector layers. If these particles carry a charge, they will ionise the gas contained within this chamber producing an electric signal as the ions drift in the chamber's electric field.

  6. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for

  7. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for

  8. Calibration of Direct Velocimetry Using Hot Wire Anemometry

    Science.gov (United States)

    Holland, Michael L.; DeSilva, Upul P.; Johnson, Joseph A., III

    1997-01-01

    We studied the functionality of the IFA300 Hot Wire Anemometry system and its feasibility for the calibration of Direct Estimator Velocimetry (DEV) using Laser Induced Florescence (LIF). The experimental setup consisted of a single-wire hot wire probe measuring one component of velocity, the anemometry computational hardware and software, an HP oscilloscope, and a table fan to produce a simple flow with fluctuations. Measurements were taken at several points in the stream wise and transverse directions in the flow and various parameters recorded such as mean velocities temperature, turbulence intensities, skewness coefficients and flatness coefficients. The IFA300 software also allowed us to perform statistical manipulations such as spectrum analysis on velocities samples and correlation. Utilization of data files, also produced by the anemometry software, and post analysis were performed to produce graphical representations of turbulent intensity versus probe position and a flow field velocity profile. We concluded that the IFA300 Hot Wire Anemometry system is a reliable and functional method for calibration of DEV using LIF. Our future intentions are to set up a test chamber such that both velocity measurement techniques can be applied simultaneously, thus the calibration.

  9. Construction and Test of New Precision Drift-Tube Chambers for the ATLAS Muon Spectrometer

    CERN Document Server

    Kroha, Hubert

    2017-01-01

    ATLAS muon detector upgrades aim for increased acceptance for muon triggering and precision tracking and for improved rate capability of the muon chambers in the high-background regions of the detector with increasing LHC luminosity. The small-diameter Muon Drift Tube (sMDT) chambers have been developed for these purposes. With half of the drift-tube diameter of the MDT chambers and otherwise unchanged operating parameters, sMDT chambers share the advantages of the MDTs, but have an order of magnitude higher rate capability and can be installed in detector regions where MDT chambers do not fit in. The chamber assembly methods have been optimized for mass production, minimizing construction time and personnel. Sense wire positioning accuracies of 5 ?micons have been achieved in serial production for large-size chambers comprising several hundred drift tubes. The construction of new sMDT chambers for installation in the 2016/17 winter shutdown of the LHC and the design of sMDT chambers in combination with new R...

  10. Optimisation of low-mass drift chambers for HADES

    Energy Technology Data Exchange (ETDEWEB)

    Garabatos, C.; Karig, W.; Muentz, C.; Steigerwald, A.; Stroth, J.; Wuestenfeld, J.; Zentek, A.; Bethge, K. [Frankfurt Univ. (Germany); Chernenko, S.; Fateev, O.; Glonti, L.; Smykov, L.; Zanewsky, Yu. [Joint Institute of Nuclear Research (JINR), 141980 Dubna (Russian Federation); Bokemeyer, H.; Koenig, W.; Stelzer, H.; Zumbruch, P. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany)

    1998-07-21

    A set of low-mass drift chambers designed for the tracking of di-electrons in the HADES spectrometer is presented. Short radiation length is ensured by using a Helium-based gas mixture and aluminium cathode wires, whereas the acceptance is maximised by limiting the width of the side frames of the detectors. The measured performance of these devices, which improves with increasing concentration of quencher gas, is shown and discussed. Position resolutions down to 70 {mu}m have been obtained under stable operation. Long-term gain stability is also reported. (orig.)

  11. Optimisation of low-mass drift chambers for HADES

    Science.gov (United States)

    Garabatos, C.; Karig, W.; Müntz, C.; Steigerwald, A.; Stroth, J.; Wüstenfeld, J.; Zentek, A.; Bethge, K.; Chernenko, S.; Fateev, O.; Glonti, L.; Smykov, L.; Zanewsky, Yu; Bokemeyer, H.; Koenig, W.; Stelzer, H.; Zumbruch, P.

    A set of low-mass drift chambers designed for the tracking of di-electrons in the HADES spectrometer is presented. Short radiation length is ensured by using a Helium-based gas mixture and aluminium cathode wires, whereas the acceptance is maximised by limiting the width of the side frames of the detectors. The measured performance of these devices, which improves with increasing concentration of quencher gas, is shown and discussed. Position resolutions down to 70 μm have been obtained under stable operation. Long-term gain stability is also reported.

  12. Ionisation chamber containing boron as a neutron detector in medical accelerator fields.

    Science.gov (United States)

    Zielczynski, M; Gryzinski, M A; Golnik, N; Tulik, P

    2007-01-01

    A combination of the recombination principle of H(10) measurements with the use of the ionisation chambers containing boron has been presented, in order to increase the relative sensitivity of the chamber to neutrons by a factor close to the radiation quality factor of photoneutrons. Three types of the chambers were investigated. Two of them were filled with BF(3) and the third one contained electrodes covered with B(4)C. All the chambers were placed in paraffin moderators. The response of the chambers was investigated, depending on gas pressure and polarising voltage. The results showed that it was possible to obtain nearly the same response of the chamber to H(10) for photons and neutrons in a restricted energy range; however, further investigations are needed to make an optimum design.

  13. Tension-filled Governance?

    DEFF Research Database (Denmark)

    Celik, Tim Holst

    Since the crisis-engrossed 1970s, and especially the 1990s, ‘governance’ has become a dominant concern and concept; notably, within particularly political science, a certain diagnosis explicitly or implicitly focused on a shift ‘from government to governance’ has become increasingly popular....... This study examines the governance phenomenon of the post-1970/1990s period from a state-situated and historically informed perspective. Specifically, taking initial analytical departure in an approach of the early 1970s associated with James O’Connor, Jürgen Habermas and Claus Offe focused...... on the statesituated tension-filled functional relationship between legitimation and accumulation, the study both historically and theoretically reworks this approach and reapplies it for the post-1970s/1990s governance period. It asks whether and to what extent governance has served as a distinctive post- 1970s/1990s...

  14. Preparing for faster filling

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Following the programmed technical stop last week, operators focussed on preparing the machine for faster filling, which includes multibunch injection and a faster pre-cycle phase.   The LHC1 screen shot during the first multibunch injection operation. The LHC operational schedule incorporates a technical stop for preventive maintenance roughly every six weeks of stable operation, during which several interventions on the various machines are carried out. Last week these included the replacement of a faulty magnet in the SPS pre-accelerator, which required the subsequent re-setting of the system of particle extraction and transfer to the LHC. At the end of last week, all the machines were handed back for operation and work could start on accommodating all the changes made into the complex systems in order for normal operation to be resumed. These ‘recovery’ operations continued through the weekend and into this week. At the beginning of this week, operators succeeded in pro...

  15. The effect of the wire design parameters on the stability of MgB{sub 2} superconducting coils

    Energy Technology Data Exchange (ETDEWEB)

    Majkic, G; Salama, K [Department of Mechanical Engineering and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-4006 (United States); Alessandrini, M; Laskaris, E T [General Electric Company, Global Research Center, Niskayuna, NY 12309 (United States)], E-mail: gmajkic@uh.edu

    2009-03-15

    The thermal stability of superconducting wires is one of the important issues for wire applications. We present a numerical study on the effect of the wire design parameters on the quench behavior of superconducting MgB{sub 2} wire employed in coils. The model considers a stack of MgB{sub 2} wires of rectangular cross section separated by insulation layers and subjected to a thermal disturbance. The problem is solved on a two-dimensional domain and employs the current sharing concept in the transition between superconducting and normal states. The effects of three design parameters in wire manufacturing are investigated. Quench behavior is compared for wires having different filling factor of superconducting filaments, different volume of copper stabilizer, and different residual resistivity ratio (RRR) values for copper. The results indicate that the quench propagation velocity (QPV) at 1.5 T is weakly affected by changes in the volume and electrical properties of copper, whereas the minimum quench energy (MQE) is strongly dependent on the RRR value of copper and can increase by a factor of nearly 2 with the RRR varying from 30 to 150. Both the MQE and QPV change remarkably by varying the MgB{sub 2} filling factor. The MQE drops by a factor of 6 and the QPV increases by a factor of 2 with the filling factor varying from 10.5% to 25%.

  16. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  17. Technical Note: Influence of Compton currents on profile measurements in small-volume ion chambers

    Energy Technology Data Exchange (ETDEWEB)

    Tanny, Sean; Sperling, Nicholas; Parsai, E. Ishmael, E-mail: e.parsai@utoledo.edu [Department of Radiation Oncology, University of Toledo Medical Center, 1325 Conference Drive, Toledo, Ohio 43614 (United States); Holmes, Shannon [Standard Imaging, 3120 Deming Way, Middleton, Wisconsin 53562 (United States)

    2015-10-15

    Purpose: This work is to evaluate the effects of Compton current generation in three small-volume ionization chambers on measured beam characteristics for electron fields. Methods: Beam scans were performed using Exradin A16, A26, and PTW 31014 microchambers. Scans with varying chamber components shielded were performed. Static point measurements, output factors, and cable only irradiations were performed to determine the contribution of Compton currents to various components of the chamber. Monte Carlo simulations were performed to evaluate why one microchamber showed a significant reduction in Compton current generation. Results: Beam profiles demonstrated significant distortion for two of the three chambers when scanned parallel to the chamber axis, produced by electron deposition within the wire. Measurements of ionization produced within the cable identified Compton current generation as the cause of these distortions. The size of the central collecting wire was found to have the greatest influence on the magnitude of Compton current generation. Conclusions: Microchambers can demonstrate significant (>5%) deviations from properties as measured with larger volume chambers (0.125 cm{sup 3} and above). These deviations can be substantially reduced by averaging measurements conducted at opposite polarities.

  18. Mechanical Behavior of Carbon Nanotubes Filled With Metal Nanowires By Atomistic Simulations

    Science.gov (United States)

    Danailov, Daniel; Keblinski, Pawel; Pulickel, Ajayan; Nayak, Saroj

    2002-03-01

    Using molecular dynamics simulations we studied mechanical behavior of (10,10) carbon nanotubes filled with a crystalline fcc metal wires. The interatomic interactions were described by a combination of Terfoff’s bond-order potential for carbon, embedded atom method (EAM) potential for metal and pair potential for carbon-metal interactions. The elastic properties, as well as failure mechanism were determined by simulating three point bending test, by pressing the center and the ends of relatively long tube in determined relatively small ring areas. We observed that following elastic response, at larger deformation, the metal wire yields well before the carbon bonding is affected. The behavior of filled tubes was compared with that of hollow tubes. Interesting is thet the hollow carbon (10,10) nanotube is more strong elastically than the same tube filled with Au-metal nanowire. We also simulated indentation of filled tubes residing on a hard flat surface. Similarly as in the bending test, metal wire yields first, is cut in between hard cylinder and hard plane and pushed away from under the indenter. Upon further increase of the indentation force, carbon tube is broken and forms two open ends that are rapidly zipped around the cut metal wire. Remarkably, the shape of the zipped tube ends strong depend of the speed of the punching of the tube. This result imply a possibility of designing tubes with various closed end shapes with applicationusing in the nanoscale manipulation procedures used for production.

  19. Monitoring Liquid Argon Time Projection Chambers With A Raspberry Pi Camera

    Science.gov (United States)

    Patteson, Crystal

    2016-03-01

    The MicroBooNE detector is the first of three liquid argon (LAr) time projection chambers (TPCs) that are central to the short-baseline neutrino program at Fermilab. These chambers consist of thousands of stainless steel or beryllium-copper sense wires that detect ionization electrons produced when neutrinos interact with liquid argon nuclei inside the detector. The wires are several hundred microns in diameter to several meters in length. The construction of such LAr TPCs often takes place in an assembly hall, which is different from the detector hall where the experiment will operate, as was the case with MicroBooNE. Since in situ access to the chamber and its wires in the beamline enclosure can be limited, we investigate the possibility of using a Raspberry Pi single-board computer connected to a low-cost camera installed inside the cryostat as a cost-efficient way to verify the integrity of the wires after transport. We also highlight other benefits of this monitoring device implemented in MicroBooNE, including detector hall surveillance and verification of the status of LED indicators on detector electronics. The author would like to thank Dr. Matthew Toups for his encouragement and guidance on this research project.

  20. The Big European Bubble Chamber

    CERN Multimedia

    1977-01-01

    The 3.70 metre Big European Bubble Chamber (BEBC), dismantled on 9 August 1984. During operation it was one of the biggest detectors in the world, producing direct visual recordings of particle tracks. 6.3 million photos of interactions were taken with the chamber in the course of its existence.

  1. Development of Fission Chamber Assembly

    Institute of Scientific and Technical Information of China (English)

    YANGJinwei; ZHANGWei; SONGXianying; LIXu

    2003-01-01

    The fission chambers which are gas counters with fissile material inside chamber,provide essential information for plasma opcharacteristics. In conjunction with the neutron flux monitor system these provide time-resolved measurements of the global neutron source strength and fusion power from thermal nuclear fusion reactor as ITER for all plasma conditions for which neutrons are produced.

  2. Influence of Flaws of Wire Rod Surface, Inclusions and Voids on Wire Breaks in Superfine Wire Drawing

    Science.gov (United States)

    Yoshida, Kazunari; Norasethasopon, Somchai; Shinohara, Tetsuo; Ido, Ryuta

    By means of the finite element analysis (FEA), this study analyzed wire breaks that occurred in the drawing fine wires containing flaws on the wire surface, inclusion and void. The deformation behavior of an inclusion was examined, in which the inclusion's location is assumed to be on the center axis of the wire, and the cause of wire breaks and their prevention method were clarified. It was found that an inclusion diameter/wire diameter ratio of 0.4 or higher increases the likelihood of wire breaks occurring. When the inclusion is not assumed to be in the center axis of the wire, it was also found that necking and wire breaks appear more frequently. FEA showed that a flaw grows with each processing step, when a small circumferential flaw is placed on the wire rod surface, and eventually becomes a surface defect, which is called a check mark in practice.

  3. National Ignition Facility Target Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Wavrik, R W; Cox, J R; Fleming, P J

    2000-10-05

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This

  4. Accumulation chamber as monitoring system for biogas emission from solid waste land filling: preliminary experimental results and elaborations on italian provincial scale; Camera di accumulo portatile per il monitoraggio di emissioni di biogas da discarica: risultati sperimentali ed elaborazioni preliminari a scala provinciale

    Energy Technology Data Exchange (ETDEWEB)

    Capaccioni, B.; Pirillo, L. [Urbino Univ. Carlo Bo, Urbino (Italy). Istituto di Vulcanologia e Geochimica; Didero, M. [Urbino Univ. Carlo Bo, Urbino (Italy). Istituto di Geologia Applicata; Lucci, P.; Scartoni, P. [Area Territorio e Ambiente Provincia di Arezzo, Arezzo (Italy). Servizio Ecologia; Tatano, F. [Urbino Univ. Carlo Bo, Urbino (Italy). Facolta' di Scienze Ambientali

    2005-04-01

    On site CO{sub 2} flux measurements with the static, not stationary accumulation chamber system were experimentally carried out in no. 5 MSW (active and closed) landfills located in the territory of the Province of Arezzo (Tuscany Region). Corresponding CO{sub 2} emission flux maps were contoured and analysed, revealing a possible, preliminary geometrical classification of biogas dispersion: diffuse dispersion (internal), lateral/angular dispersion (internal), and external dispersion. Also specific (volume and surface) biogas emission parameters were calculated and graphically compared for the monitored inactive facilities. [Italian] La metodologia strumentale portatile della camera di accumulo, statica non stazionaria, e' stata adoperata sperimentalmente per la misura on site di flussi puntuali di emissione di CO{sub 2} in cinque discariche (attive e non) per RSU ed assimilabili localizzate nel territorio della Provincia di Arezzo. Si sono elaborate, ed analizzate criticamente, le corrispondenti mappe areali di flusso, che hanno consentito di delineare una possibile classificazione geometrica - ancorche' preliminare - di dispersioni di biogas generabili da discarica: diffuse interne, laterali/angolari interne, esterne. Con riferimento alle discariche inattive d'indagine, si sono altresi' determinati, e rappresentati graficamente, i valori di possibili parametri specifici (volumetrico, superficiale) di dispersione di biogas.

  5. Cavity Mode Related Wire Breaking of the SPS Wire Scanners and Loss Measurements of Wire Materials

    CERN Document Server

    Caspers, Friedhelm; Jensen, E; Koopman, J; Malo, J F; Roncarolo, F

    2003-01-01

    During the SPS high intensity run 2002 with LHC type beam, the breaking of several of the carbon wires in the wire scanners has been observed in their parking position. The observation of large changes in the wire resistivity and thermionic electron emission clearly indicated strong RF heating that was depending on the bunch length. A subsequent analysis in the laboratory, simulating the beam by two probe antennas or by a powered stretched wire, showed two main problems: i) the housing of the wire scanner acts as a cavity with a mode spectrum starting around 350 MHz and high impedance values around 700 MHz; ii) the carbon wire used so far appears to be an excellent RF absorber and thus dissipates a significant part of the beam-induced power. Different wire materials are compared with the classical cavity mode technique for the determination of the complex permittivity in the range of 2-4 GHz. As a resonator a rectangular TE_01n type device is utilized.

  6. Cavity mode related wire breaking of the SPS Wire Scanners and loss measurements of wire materials

    CERN Document Server

    Roncarolo, Federico

    2003-01-01

    During the SPS high intensity run 2002 with LHC type beam, the breaking of several of the carbon wires in the wire scanners has been observed in their parking position. The observation of large changes in the wire resistivity and thermionic electron emission clearly indicated strong RF heating that was depending on the bunch length. A subsequent analysis in the laboratory, simulating the beam by two probe antennas or by a powered stretched wire, showed two main problems: i) the housing of the wire scanner acts as a cavity with a mode spectrum starting around 350MHz and high impedance values around 700 MHz; ii) the carbon wire used so far appears to be an excellent RF absorber and thus dissipates a significant part of the beam-induced power. Different wire materials are compared with the classical cavity mode technique for the determination of the complex permittivity in the range of 2-4 GHz. As a resonator a rectangular TE01n type device is utilized.

  7. "Cut wires grating – single longitudinal wire" planar metastructure to achieve microwave magnetic resonance in a single wire

    OpenAIRE

    G. Kraftmakher; V. Butylkin

    2012-01-01

    Here we present metastructures containing cut-wire grating and a single longitudinal cut-wire orthogonal to grating’s wires. Experimental investigations at microwaves show these structures can provide strong magnetic resonant response of a single nonmagnetic cut-wire in dependence on configuration and sizes in the case when metastructures are oriented along the direction of wave propagation and cut-wires of grating are parallel to the electric field of a plane electromagnetic wave. It is sugg...

  8. BEBC, the Big European Bubble Chamber

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    The vessel of the Big European Bubble Chamber, BEBC, was installed at the beginning of the 1970s. The large stainless-steel vessel, measuring 3.7 metres in diameter and 4 metres in height, was filled with 35 cubic metres of liquid (hydrogen, deuterium or a neon-hydrogen mixture), whose sensitivity was regulated by means of a huge piston weighing 2 tonnes. During each expansion, the trajectories of the charged particles were marked by a trail of bubbles, where liquid reached boiling point as they passed through it. The first images were recorded in 1973 when BEBC, equipped with the largest superconducting magnet in service at the time, first received beam from the PS. In 1977, the bubble chamber was exposed to neutrino and hadron beams at higher energies of up to 450 GeV after the SPS came into operation. By the end of its active life in 1984, BEBC had delivered a total of 6.3 million photographs to 22 experiments devoted to neutrino or hadron physics. Around 600 scientists from some fifty laboratories through...

  9. Adhesive sealing of the pulp chamber.

    Science.gov (United States)

    Belli, S; Zhang, Y; Pereira, P N; Pashley, D H

    2001-08-01

    The purpose of this in vitro study was to evaluate quantitatively the ability of four different filling materials to seal the orifices of root canals as a secondary seal after root canal therapy. Forty extracted human molar teeth were used. The top of pulp chambers and distal halves of the roots were removed using an Isomet saw. The canal orifices were temporarily sealed with a gutta-percha master cone without sealer. The pulp chambers were then treated with a self-etching primer adhesive system (Clearfil SE Bond), a wet bonding system (One-Step), a 4-methacryloyloxyethyl trimellitate anhydride adhesive system (C&B Metabond), or a reinforced zinc oxide-eugenol (IRM). The specimens were randomly divided into four groups of 10 each. A fluid filtration method was used for quantitative evaluation of leakage. Measurements of fluid movement were made at 2-min intervals for 8 min. The quality of the seal of each specimen was measured by fluid filtration immediately and after 1 day, 1 wk, and 1 month. Even after 1 month the resins showed an excellent seal. Zinc oxide-eugenol had significantly more leakage when compared with the resin systems (p < 0.05). Adhesive resins should be considered as a secondary seal to prevent intraorifice microleakage.

  10. LET measurements with a liquid ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Tegami, Sara

    2013-02-08

    Deep-seated tumors can be efficiently treated with heavy charged particles. The characteristic depth dose profile inside the tissue (Bragg peak) allows to deliver a high dose inside the tumor, while sparing the neighboring healthy tissue. As compared to protons, heavy ions like carbon or oxygen produce a higher amount of ionization events along their track (and in particular at the end of the ion beam path), resulting in an irreparable damage to the DNA of the tumor cells. The density of such ionization events is described in terms of Linear Energy Transfer (LET), an important physical quantity, but difficult to be measured directly. The aim of this work is to determine LET of hadrontherapy beams by using Liquid Ionization Chambers (LIC). The ionization signal in LICs is affected by recombination effects that depend on the LET of the incident radiation. Differences in recombination effects in LICs and air-filled ionization chambers can be exploited to obtain the recombination index, which can be related to the LET, calculated by Monte Carlo methods. We thus developed a method to construct a calibration curve, which relates the recombination index with the LET at each depth in water. The result of this work can be used for online monitoring of the ion beam quality.

  11. Superconducting wires and fractional flux

    Science.gov (United States)

    Sá de Melo, C. A. R.

    1996-05-01

    The quantization of flux quanta in superconductors is revisited and analyzed in a new geometry. The system analyzed is a superconducting wire. The geometry is such that the superconducting wire winds N times around an insulating cylinder and that the wire has its end connected back to its beginning, thus producing an N-loop short circuited solenoid. The winding number N acts as a topological index that controls flux quantization. In this case, fractional flux quanta can be measured through the center of the insulating cylinder, provided that the cylinder radius is small enough. The Little-Parks experiment for an identical geometry is discussed. The period of oscillation of the transition temperature of the wire is found to vary as 1/N in units of flux Φ relative to the flux quantum Φ0. When a SQUID is made in such a geometry the maximal current through the SQUID varies with period Φ0/N.

  12. Wire ropes tension, endurance, reliability

    CERN Document Server

    Feyrer, Klaus

    2015-01-01

    The main goal of this book is to present the methods used to calculate the most important parameters for ropes, and to explain how they are applied on the basis of numerous sample calculations. The book, based on the most important chapters of the German book DRAHTSEILE, has been updated to reflect the latest developments, with the new edition especially focusing on computational methods for wire ropes. Many new calculations and examples have also been added to facilitate the dimensioning and calculation of mechanical characteristics of wire ropes. This book offers a valuable resource for all those working with wire ropes, including construction engineers, operators and supervisors of machines and installations involving wire ropes.

  13. Wire Jewelry/Black History.

    Science.gov (United States)

    Daniel, Robert A.; Robinson, Charles C.

    1984-01-01

    Described is a project which made the study of Black history more real to fifth graders by having them make wire jewelry, smaller versions of the ornate filigreed ironwork produced by slave blacksmiths. (RM)

  14. Dieless wire drawing with lasers

    Science.gov (United States)

    Liedl, G.; Schuöcker, D.

    2007-06-01

    Thin wires are produced by drawing through nozzle-like tools, so called dies, that suffer from strong wear due to friction. In order to avoid the latter disadvantage the dies can be replaced by a laser beam heating the wire to such extend that the yield strength becomes smaller than the tensile strength and thus the wire is elongated and consequently constricted. To avoid rupture, the wire is cooled down again after the desired reduction of the diameter is reached. A further important advantage of this new process is that only one drawing step with a laser can substitute a large number of mechanical drawing actions, thus making the process much more efficient. Theoretical considerations and experimental investigations prove the feasibility of the latter new laser process and are subject to a description in the actual paper.

  15. 49 CFR 236.74 - Protection of insulated wire; splice in underground wire.

    Science.gov (United States)

    2010-10-01

    ... underground wire. 236.74 Section 236.74 Transportation Other Regulations Relating to Transportation (Continued... wire; splice in underground wire. Insulated wire shall be protected from mechanical injury. The insulation shall not be punctured for test purposes. Splice in underground wire shall have insulation...

  16. 49 CFR 234.241 - Protection of insulated wire; splice in underground wire.

    Science.gov (United States)

    2010-10-01

    ... underground wire. 234.241 Section 234.241 Transportation Other Regulations Relating to Transportation... of insulated wire; splice in underground wire. Insulated wire shall be protected from mechanical injury. The insulation shall not be punctured for test purposes. A splice in underground wire shall have...

  17. Composite conductor containing superconductive wires

    Energy Technology Data Exchange (ETDEWEB)

    Larson, W.L.; Wong, J.

    1974-03-26

    A superconductor cable substitute made by coworking multiple rods of superconductive niobium--titanium or niobium--zirconium alloy with a common copper matrix to extend the copper and rods to form a final elongated product which has superconductive wires distributed in a reduced cross-section copper conductor with a complete metallurgical bond between the normal-conductive copper and the superconductor wires contained therein is described. The superconductor cable can be in the form of a tube.

  18. Method of manufacturing superconductor wire

    Science.gov (United States)

    Motowidlo, Leszek

    2014-09-16

    A method for forming Nb.sub.3Sn superconducting wire is provided. The method employs a powder-in-tube process using a high-tin intermetallic compound, such as MnSn.sub.2, for producing the Nb.sub.3Sn. The use of a high-tin intermetallic compound enables the process to perform hot extrusion without melting the high-tin intermetallic compound. Alternatively, the method may entail drawing the wire without hot extrusion.

  19. Topology Optimized Photonic Wire Splitters

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Borel, Peter Ingo; Jensen, Jakob Søndergaard;

    2006-01-01

    Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm.......Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm....

  20. Experimental study of the intraventricular filling vortex in diastolic dysfunction

    Science.gov (United States)

    Santhanakrishnan, Arvind; Samaee, Milad; Nelsen, Nicholas

    2016-11-01

    Heart failure with normal ejection fraction (HFNEF) is a clinical syndrome that is prevalent in over half of heart failure patients. HFNEF patients typically show diastolic dysfunction, caused by a decrease in relaxation capability of the left ventricular (LV) muscle tissue and/or an increase in LV chamber stiffness. Numerous studies using non-invasive medical imaging have shown that an intraventricular filling vortex is formed in the LV during diastole. We conducted 2D particle image velocimetry and hemodynamics measurements on a left heart simulator to investigate diastolic flow under increasing LV wall stiffness, LV wall thickness and heart rate (HR) conditions. Flexible-walled, optically clear LV physical models cast from silicone were fitted within a fluid-filled acrylic chamber. Pulsatile flow within the LV model was generated using a piston pump and 2-component Windkessel elements were used to tune the least stiff (baseline) LV model to physiological conditions. The results show that peak circulation of the intraventricular filling vortex is diminished in conditions of diastolic dysfunction as compared to the baseline case. Increasing HR exacerbated the circulation of the filling vortex across all cases.

  1. 1 mil gold bond wire study.

    Energy Technology Data Exchange (ETDEWEB)

    Huff, Johnathon; McLean, Michael B.; Jenkins, Mark W.; Rutherford, Brian Milne

    2013-05-01

    In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations.

  2. HTS Wire Development Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  3. Wire Scanner Motion Control Card

    CERN Document Server

    Forde, S E

    2006-01-01

    Scientists require a certain beam quality produced by the accelerator rings at CERN. The discovery potential of LHC is given by the reachable luminosity at its interaction points. The luminosity is maximized by minimizing the beam size. Therefore an accurate beam size measurement is required for optimizing the luminosity. The wire scanner performs very accurate profile measurements, but as it can not be used at full intensity in the LHC ring, it is used for calibrating other profile monitors. As the current wire scanner system, which is used in the present CERN accelerators, has not been made for the required specification of the LHC, a new design of a wire scanner motion control card is part of the LHC wire scanner project. The main functions of this card are to control the wire scanner motion and to acquire the position of the wire. In case of further upgrades at a later stage, it is required to allow an easy update of the firmware, hence the programmable features of FPGAs will be used for this purpose. The...

  4. Vibrating wires for beam diagnostics

    CERN Document Server

    Arutunian, S G; Wittenburg, Kay

    2015-01-01

    A new approach to the technique of scanning by wires is developed. Novelty of the method is that the wire heating quantity is used as a source of information about the number of interacting particles. To increase the accuracy and sensitivity of measurements the wire heating measurement is regenerated as a change of wire natural oscillations frequency. By the rigid fixing of the wire ends on the base an unprecedented sensitivity of the frequency to the temperature and to the corresponding flux of colliding particles. The range of used frequencies (tens of kHz) and speed of processes of heat transfer limit the speed characteristics of proposed scanning method, however, the high sensitivity make it a perspective one for investigation of beam halo and weak beam scanning. Traditional beam profile monitors generally focus on the beam core and loose sensitivity in the halo region where a large dynamic range of detection is necessary. The scanning by a vibrating wire can be also successfully used in profiling and det...

  5. Connecting to Thermocouples with Fewer Lead Wires

    Science.gov (United States)

    Goldsby, Jon C.

    2003-01-01

    A simple technique has been devised to reduce the number of lead wires needed to connect an array of thermocouples to the instruments (e.g., voltmeters) used to read their output voltages. Because thermocouple wires are usually made of expensive metal alloys, reducing the number of lead wires can effect a considerable reduction in the cost of such an array. Reducing the number of wires also reduces the number of terminals and the amount of space needed to accommodate the wires.

  6. Improved Gas Filling and Sealing of an HC-PCF

    Science.gov (United States)

    Poberezhskiy, Ilya; Meras, Patrick; Chang, Daniel; Spiers, Gary

    2008-01-01

    An improved packaging approach has been devised for filling a hollow-core photonic-crystal fiber (HC-PCF) with a gas, sealing the HC-PCF to retain the gas, and providing for optical connections and, optionally, a plumbing fitting for changing or augmenting the gas filling. Gas-filled HC-PCFs can be many meters long and have been found to be attractive as relatively compact, lightweight, rugged alternatives to conventional gas-filled glass cells for use as molecular-resonance frequency references for stabilization of lasers in some optical-metrology, lidar, optical-communication, and other advanced applications. Prior approaches to gas filling and sealing of HC-PCFs have involved, variously, omission of any attempt to connectorize the PCF, connectorization inside a vacuum chamber (an awkward and expensive process), or temporary exposure of one end of an HC-PCF to the atmosphere, potentially resulting in contamination of the gas filling. Prior approaches have also involved, variously, fusion splicing of HC-PCFs with other optical fibers or other termination techniques that give rise to Fresnel reflections of about 4 percent, which results in output intensity noise.

  7. High-Accuracy Measurements of the Centre of Gravity of Avalanches in Proportional Chambers

    Science.gov (United States)

    Charpak, G.; Jeavons, A.; Sauli, F.; Stubbs, R.

    1973-09-24

    In a multiwire proportional chamber the avalanches occur close to the anode wires. The motion of the positive ions in the large electric fields at the vicinity of the wires induces fast-rising positive pulses on the surrounding electrodes. Different methods have been developed in order to determine the position of the centre of the avalanches. In the method we describe, the centre of gravity of the pulse distribution is measured directly. It seems to lead to an accuracy which is limited only by the stability of the spatial distribution of the avalanches generated by the process being measured.

  8. Fracture strength of different soldered and welded orthodontic joining configurations with and without filling material.

    Science.gov (United States)

    Bock, Jens Johannes; Bailly, Jacqueline; Gernhardt, Christian Ralf; Fuhrmann, Robert Andreas Werner

    2008-01-01

    The aim of this study was to compare the mechanical strength of different joints made by conventional brazing, TIG and laser welding with and without filling material. Five standardized joining configurations of orthodontic wire in spring hard quality were used: round, cross, 3 mm length, 9 mm length and 7 mm to orthodontic band. The joints were made by five different methods: brazing, tungsten inert gas (TIG) and laser welding with and without filling material. For the original orthodontic wire and for each kind of joint configuration or connecting method 10 specimens were carefully produced, totalizing 240. The fracture strengths were measured with a universal testing machine (Zwick 005). Data were analyzed by ANOVA (p=0.05) and Bonferroni post hoc test (p=0.05). In all cases, brazing joints were ruptured on a low level of fracture strength (186-407 N). Significant differences between brazing and TIG or laser welding (pfracture strength means were observed for laser welding with filling material and 3 mm joint length (998 N). Using filling materials, there was a clear tendency to higher mean values of fracture strength in TIG and laser welding. However, statistically significant differences were found only in the 9-mm long joints (pfracture strength of welded joints was positively influenced by the additional use of filling material. TIG welding was comparable to laser welding except for the impossibility of joining orthodontic wire with orthodontic band.

  9. Comparison of experimental and calculated calibration coefficients for a high sensitivity ionization chamber.

    Science.gov (United States)

    Amiot, M N; Mesradi, M R; Chisté, V; Morin, M; Rigoulay, F

    2012-09-01

    The response of a Vacutec 70129 ionization chamber was calculated using the PENELOPE-2008 Monte Carlo code and compared to experimental data. The filling gas mixture composition and its pressure have been determined using IC simulated response adjustment to experimental results. The Monte Carlo simulation revealed a physical effect in the detector response to photons due to the presence of xenon in the chamber. A very good agreement is found between calculated and experimental calibration coefficients for 17 radionuclides.

  10. Track chambers based on precision drift tubes housed inside 30 mm mylar pipe

    Science.gov (United States)

    Borisov, A.; Bozhko, N.; Fakhrutdinov, R.; Kozhin, A.; Leontiev, B.; Levin, A.

    2014-06-01

    We describe drift chambers consisting of 3 layers of 30 mm (OD) drift tubes made of double sided aluminized mylar film with thickness 0.125 mm. A single drift tube is self-supported structure withstanding 350 g tension of 50 microns sense wire located in the tube center with 10 microns precision with respect to end-plug outer surface. Such tubes allow to create drift chambers with small amount of material, construction of such chambers doesn't require hard frames. Twenty six chambers with working area from 0.8 × 1.0 to 2.5 × 2.0 m2 including 4440 tubes have been manufactured for experiments at 70-GeV proton accelerator at IHEP(Protvino).

  11. Trapping of ultracold polar molecules with a Thin Wire Electrostatic Trap

    CERN Document Server

    Kleinert, J; Zabawa, P J; Bigelow, N P

    2007-01-01

    We describe the realization of a DC electric field trap for ultracold polar molecules, the Thin WIre electroStatic Trap (TWIST). The thin wires that form the electrodes of the TWIST allow us to superimpose the trap onto a magneto-optical trap (MOT). In our experiment, ultracold polar NaCs molecules in their electronic ground state are created in the MOT via photoassociation, achieving a continuous accumulation in the TWIST of molecules in low-field seeking states. Initial measurements show that the TWIST trap lifetime is limited only by the background pressure in the chamber.

  12. The multigap resistive plate chamber

    Energy Technology Data Exchange (ETDEWEB)

    Zeballos, E. Cerron [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Crotty, I. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Hatzifotiadou, D. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Valverde, J. Lamas [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Univ. Louis Pasteur, Strasbourg (France); Neupane, S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Williams, M. C. S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Zichichi, A. [Univ. of Bologna, Bologna (Italy)

    2015-02-03

    The paper describes the multigap resistive plate chamber (RPC). This is a variant of the wide gap RPC. However it has much improved time resolution, while keeping all the other advantages of the wide gap RPC design.

  13. Cyclically controlled welding purge chamber

    Science.gov (United States)

    Gallagher, Robert L. (Inventor)

    1996-01-01

    An arrangement for butt-welding cylindrical sections of large, thin-wall tanks includes a rotatable mandrel with side-by-side sets of radial position adjusters. Each set of adjusters bears on one of the tank sections adjacent the seam, to prevent the sections from sagging out-of-round. The mandrel rotates relative to the welder, so that a continuous seam is formed. A purge chamber is fixed in position behind the seam at the weld head, and is flushed with inert gas. The purge chamber includes a two-sided structure which is contiguous with the cylindrical sections and a circumferential vane to form an open-ended tube-like structure, through which the radial position adjusters pass as the mandrel and cylindrical workpiece sections rotate. The tube-like structure is formed into a chamber by a plurality of movable gates which are controlled to maintain a seal while allowing adjusters to progress through the purge chamber.

  14. The PHENIX Time Expansion Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Rosati, M.; Barish, K.; Botelho, S.; Chang, W.C.; Gogoi, A.L. de; Dietzsch, O.; Ferdousi, T.; Franz, A.; Fung, S.Y.; Gannon, J.; Harder, J.; Kandasamy, A.; Khomutnikov, A.; Kotchekov, D.; Lebedev, A.; Li, X.H.; Mahon, J.; Munirassimann, M.; Negrin, J.; O' Brien, E.; O' Connor, P.; Pisani, R.; Rankowitz, S.; Seto, R.; Takagui, E.M.; Wang, H.Q

    1999-12-27

    The TEC/TRD subsystem will track all charged particles and contribute to the particle identification by the measurement of energy loss. The design, construction and testing of the TEC chambers are described.

  15. The PHENIX Time Expansion Chamber

    CERN Document Server

    Rosati, M; Botelho, S; Chang, W C; Gogoi, A L D; Dietzsch, O; Ferdousi, T; Franz, A; Fung, S Y; Gannon, J; Harder, J; Kandasamy, A; Khomutnikov, A; Kotchekov, D; Lebedev, A; Li, X H; Mahon, J; Munirassimann, M; Negrin, J; O'Brien, E; O'Connor, P; Pisani, R; Rankowitz, S; Seto, R; Takagui, E M; Wang, H Q

    1999-01-01

    The TEC/TRD subsystem will track all charged particles and contribute to the particle identification by the measurement of energy loss. The design, construction and testing of the TEC chambers are described.

  16. Vacuum chambers for LHC LSS

    CERN Document Server

    Costa-Pinto, P

    2004-01-01

    The approximately 6 km total length of the Large Hadron Collider (LHC) warm sections consist of about 1000 chambers. Most of these chambers, of various length and cross sections, are made of copper, but different lengths in stainless steel, mumetal, aluminium and beryllium will also be used. All the chambers will be internally coated with a thin film of TiZrV, to reduce both the secondary electron yield and the photon and electron stimulated desorption, with the further advantage of providing a huge additional pumping speed. In order to cope with the tight production schedule, a new dedicated coating facility was created, which allows four chambers to be coated per working day. This coating facility and its operating mode are described, together with the TiZrV film characteristics (structure, morphology) and performance (pumping speed, ultimate pressure, discharge gas outgassing).

  17. Vaporization chambers and associated methods

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Terry D.; Wilding, Bruce M.; McKellar, Michael G.; Shunn, Lee P.

    2017-02-21

    A vaporization chamber may include at least one conduit and a shell. The at least one conduit may have an inlet at a first end, an outlet at a second end and a flow path therebetween. The shell may surround a portion of each conduit and define a chamber surrounding the portion of each conduit. Additionally, a plurality of discrete apertures may be positioned at longitudinal intervals in a wall of each conduit, each discrete aperture of the plurality of discrete apertures sized and configured to direct a jet of fluid into each conduit from the chamber. A liquid may be vaporized by directing a first fluid comprising a liquid into the inlet at the first end of each conduit, directing jets of a second fluid into each conduit from the chamber through discrete apertures in a wall of each conduit and transferring heat from the second fluid to the first fluid.

  18. BEBC Big European Bubble Chamber

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    A view of the dismantling of the magnet of BEBC, the 3.7 m European Bubble Chamber : iron magnetic shielding ; lower and upper parts of the vacuum enclosure of the magnet; turbo-molecular vacuum pumps for the "fish-eye" windows; the two superconducting coils; a handling platform; the two cryostats suspended from the bar of the travelling crane which has a 170 ton carrying capacity. The chamber proper, not dismantled, is inside the shielding.

  19. Medication safety: Filling your prescription

    Science.gov (United States)

    ... medicines. Also learn what each medicine looks like. Filling Your Prescriptions Your health plan may require you to use certain pharmacies. ... standards. The website should have clear directions for filling or ... seeing you. Make sure your health plan will cover the cost of using the ...

  20. Anterior chamber depth during hemodialysis

    Directory of Open Access Journals (Sweden)

    Gracitelli CPB

    2013-08-01

    Full Text Available Carolina Pelegrini Barbosa Gracitelli,1 Francisco Rosa Stefanini,1 Fernando Penha,1 Miguel Ângelo Góes,2 Sérgio Antonio Draibe,2 Maria Eugênia Canziani,2 Augusto Paranhos Junior1 1Ophthalmology Department, 2Division of Nephrology, Federal University of São Paulo – UNIFESP, São Paulo, Brazil Background: Exacerbation of chronic glaucoma or acute glaucoma is occasionally observed in patients undergoing hemodialysis (HD because of anterior chamber depth changes during this therapy. Purpose: To evaluate anterior chamber depth and axial length in patients during HD sessions. Methods: A total of 67 eyes of 35 patients were prospectively enrolled. Axial length and anterior chamber depth were measured using ultrasonic biometry, and these measures were evaluated at three different times during HD sessions. Body weight and blood pressure pre- and post-HD were also measured. Results: There was no difference in the axial length between the three measurements (P = 0.241. We observed a significantly decreased anterior chamber depth (P = 0.002 during HD sessions. Conclusion: Our results support the idea that there is a change in anterior chamber depth in HD sessions. Keywords: anterior chamber, hemodialysis, axial length, acute angle-closure glaucoma

  1. Californium Recovery from Palladium Wire

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-08-01

    The recovery of 252Cf from palladium-252Cf cermet wires was investigated to determine the feasibility of implementing it into the cermet wire production operation at Oak Ridge National Laboratory’s Radiochemical Engineering Development Center. The dissolution of Pd wire in 8 M HNO3 and trace amounts of HCl was studied at both ambient and elevated temperatures. These studies showed that it took days to dissolve the wire at ambient temperature and only 2 hours at 60°C. Adjusting the ratio of the volume of solvent to the mass of the wire segment showed little change in the kinetics of dissolution, which ranged from 0.176 mL/mg down to 0.019 mL/mg. A successful chromatographic separation of 153Gd, a surrogate for 252Cf, from Pd was demonstrated using AG 50x8 cation exchange resin with a bed volume of 0.5 mL and an internal diameter of 0.8 cm.

  2. Californium Recovery from Palladium Wire

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-08-01

    The recovery of 252Cf from palladium-252Cf cermet wires was investigated to determine the feasibility of implementing it into the cermet wire production operation at Oak Ridge National Laboratory’s Radiochemical Engineering Development Center. The dissolution of Pd wire in 8 M HNO3 and trace amounts of HCl was studied at both ambient and elevated temperatures. These studies showed that it took days to dissolve the wire at ambient temperature and only 2 hours at 60°C. Adjusting the ratio of the volume of solvent to the mass of the wire segment showed little change in the kinetics of dissolution, which ranged from 0.176 mL/mg down to 0.019 mL/mg. A successful chromatographic separation of 153Gd, a surrogate for 252Cf, from Pd was demonstrated using AG 50x8 cation exchange resin with a bed volume of 0.5 mL and an internal diameter of 0.8 cm.

  3. Mechanics of filled carbon nanotubes

    KAUST Repository

    Monteiro, A.O.

    2014-04-01

    The benefits of filling carbon nanotubes (CNTs) with assorted molecular and crystalline substances have been investigated for the past two decades. Amongst the study of new structural phases, defects, chemical reactions and varied types of host-guest interactions, there is one fundamental characterisation aspect of these systems that continues to be overlooked: the mechanical behaviour of filled CNTs. In contrast to their empty counterparts, the mechanics of filled CNTs is a subject where reports appear far and apart, this despite being key to the application of these materials in technological devices. In the following paragraphs, we review the work that has been carried out up to the present on the mechanics of filled CNTs. The studies discussed range from experimental resonant frequency essays performed within electron microscopes to modelling, via molecular dynamics, of three-point bending of nanotubes filled with gases. (C) 2014 Elsevier B.V. All rights reserved.

  4. Development of a Grid Ionization Chamber for a Dram of α Ray

    Directory of Open Access Journals (Sweden)

    YANG Lu;WANG Qiang;ZHENG Yu-lai;WANG Guo-bao

    2016-11-01

    Full Text Available This article introduced the parallel grid ionization chamber that used to measure the α radioactivity, which had a independent vacuum system. The system was composed of main body of the chamber, gas-filled and electronics system. Energy resolution was 26 keV for 239Pu, background was 10 counts for one hour from 4 MeV to 6 MeV energy range, the stability of 24 hours was less than 0.5% . The chamber can measure the energy of nuclide and analyze the energy spectrum structure to identify nuclear.

  5. Chamber for in situ WAXS, SAXS and GISAXS studies: application to plasma induced transformations in steels

    CERN Document Server

    Kellermann, G; Feugeas, J; Craievich, A F

    2001-01-01

    A chamber for in situ WAXS, SAXS and GISAXS studies of polycrystalline and amorphous materials was designed and constructed. It is used under vacuum or filled with a gas mixture to operate as a reactor where a plasma for materials surface treatment is produced. The WAXS intensity is recorded by an external imaging plate moving parallel to the chamber axis, making it possible to obtain successive patterns during in situ studies of structural transformations. The chamber is also used for classical SAXS and GISAXS studies of thin films.

  6. Increasing the isotropic properties of a discharge spark chamber with a large gap

    Science.gov (United States)

    Nurgozhin, N. N.

    1975-01-01

    The recording of particle tracks in the form of sparks or streamers running at different angles toward the electric field of the chamber was studied. The investigations were performed with two discharge spark chambers consisting of boxes filled with neon at 1 atm. The spark chambers were powered by a pulse with an amplitude of 300 kV applied from a pulse generator. The recording of particle tracks in the form of sparks took place at track angles smaller than 30 deg with respect to the electrical field. At angle larger than 40 deg the tracks are recorded in the form of streamers. Particle traces with respect to the angle are given.

  7. Commissioning of a large segmented ion chamber for the FMA

    Energy Technology Data Exchange (ETDEWEB)

    Lister, C.J.; Davids, C.N.; Blumenthal, D.J. [and others

    1995-08-01

    A large-area sectored ion chamber was built by a Yale-Daresbury (U.K.) - ANL collaboration to allow extensions of studies of N = Z (T = 0) nuclei. The ion chamber is a conventional DE-DE-E detector which is 20-cm deep, but each anode is segmented into eight pads to allow high count-rate capability and ray-trace reconstruction. With suitable electronics, the detector can become eight close-packed ion chambers, considerably reducing the count rate in each. A position-wire plane allows further raytracing which should permit the rejection of anomalous trajectories and improve Z-separation. A brief test run was scheduled shortly after delivery. Performance appeared promising, but issues of gain matching and cross talk need further exploration. We will study these features {open_quotes}off line{close_quotes} and hope to perform a full experiment on selenium isotopes in the summer. This detector appears to have many uses and is potentially more useful than previous detectors of its type. Similar detectors are being built for the HHRF at Oak Ridge and for Texas A&M University.

  8. Larger sized wire arrays on 1.5 MA Z-pinch generator

    Energy Technology Data Exchange (ETDEWEB)

    Safronova, A. S., E-mail: alla@unr.edu; Kantsyrev, V. L., E-mail: alla@unr.edu; Weller, M. E., E-mail: alla@unr.edu; Shlyaptseva, V. V., E-mail: alla@unr.edu; Shrestha, I. K., E-mail: alla@unr.edu; Esaulov, A. A., E-mail: alla@unr.edu; Stafford, A., E-mail: alla@unr.edu [Physics Department, University of Nevada, Reno, NV 89557 (United States); Chuvatin, A. S. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, Palaiseau, 91128 (France); Coverdale, C. A.; Jones, B. [Sandia National Laboratories, Albuquerque, NM 87185 (United States)

    2014-12-15

    Experiments on the UNR Zebra generator with Load Current Multiplier (LCM) allow for implosions of larger sized wire array loads than at standard current of 1 MA. Advantages of larger sized planar wire array implosions include enhanced energy coupling to plasmas, better diagnostic access to observable plasma regions, and more complex geometries of the wire loads. The experiments with larger sized wire arrays were performed on 1.5 MA Zebra with LCM (the anode-cathode gap was 1 cm, which is half the gap used in the standard mode). In particular, larger sized multi-planar wire arrays had two outer wire planes from mid-atomic-number wires to create a global magnetic field (gmf) and plasma flow between them. A modified central plane with a few Al wires at the edges was put in the middle between outer planes to influence gmf and to create Al plasma flow in the perpendicular direction (to the outer arrays plasma flow). Such modified plane has different number of empty slots: it was increased from 6 up to 10, hence increasing the gap inside the middle plane from 4.9 to 7.7 mm, respectively. Such load configuration allows for more independent study of the flows of L-shell mid-atomic-number plasma (between the outer planes) and K-shell Al plasma (which first fills the gap between the edge wires along the middle plane) and their radiation in space and time. We demonstrate that such configuration produces higher linear radiation yield and electron temperatures as well as advantages of better diagnostics access to observable plasma regions and how the load geometry (size of the gap in the middle plane) influences K-shell Al radiation. In particular, K-shell Al radiation was delayed compared to L-shell mid-atomic-number radiation when the gap in the middle plane was large enough (when the number of empty slots was increased up to ten)

  9. 30 CFR 57.12047 - Guy wires.

    Science.gov (United States)

    2010-07-01

    ... Underground § 57.12047 Guy wires. Guy wires of poles supporting high-voltage transmission lines shall meet the... “Safety Rules for the Installation and Maintenance of Electric Supply and Communication Lines”...

  10. Evaluation of high temperature stranded hookup wire

    Science.gov (United States)

    Donnelly, J. H.; Moore, H. J., Jr.

    1967-01-01

    Tests are performed on wire and insulation materials to determine selection for electronic space assemblies. Wire characteristics of tensile strength, flexibility, conductivity, and general workability are tested. Knowledge of the advantages and limitations of these materials should prevent overspecification.

  11. TCP/IP Over SpaceWire

    Science.gov (United States)

    Mills, S.; Parkes, S.

    The SpaceWire standard defines a network designed for handling payload data and control information onboard a spacecraft. Among the goals of SpaceWire are re-usability and reliability. The use of network protocols on top of SpaceWire is expected to enhance the already rich re-usability and reliability characteristics of SpaceWire. The Space Systems Research Group at the University of Dundee have developed software to allow data to be sent over SpaceWire using standard network protocols such as TCP/IP, as part of a program of work looking at network protocols for SpaceWire. This paper describes network protocols and their relationship to SpaceWire, introduces software written to allow network protocols to be layered on to SpaceWire, describes the research behind the development of this software, and gives results of some tests and observations made using the software.

  12. Temperature changes of pulp chamber during in vitro laser welding of orthodontic attachments.

    Science.gov (United States)

    Işman, Eren; Okşayan, Rıdvan; Sökücü, Oral; Üşümez, Serdar

    2014-01-01

    The use of lasers has been suggested for orthodontists to fabricate or repair orthodontic appliances by welding metals directly in the mouth. This work aimed to evaluate the temperature changes in the pulp chamber during welding of an orthodontic wire to an orthodontic molar band using Nd : YAG laser in vitro. A freshly extracted human third molar with eliminated pulpal tissues was used. J-type thermocouple wire was positioned in the pulp chamber. A conductor gel was used in the transferring of outside temperature changes to the thermocouple wire. An orthodontic band was applied to the molar tooth and bonded using light cured orthodontic cement. Twenty five mm length of 0.6 mm diameter orthodontic stainless steel wires was welded to the orthodontic band using Nd : YAG laser operated at 9.4 watt. Temperature variation was determined as the change from baseline temperature to the highest temperature was recorded during welding. The recorded temperature changes were between 1.8 and 6.8°C (mean: 3.3±1.1°C). The reported critical 5.5°C level was exceeded in only one sample. The results of this study suggest that intraoral use of lasers holds great potential for the future of orthodontics and does not present a thermal risk. Further studies with larger samples and structural analysis are required.

  13. Temperature Changes of Pulp Chamber during In Vitro Laser Welding of Orthodontic Attachments

    Science.gov (United States)

    İşman, Eren; Okşayan, Rıdvan; Sökücü, Oral; Üşümez, Serdar

    2014-01-01

    The use of lasers has been suggested for orthodontists to fabricate or repair orthodontic appliances by welding metals directly in the mouth. This work aimed to evaluate the temperature changes in the pulp chamber during welding of an orthodontic wire to an orthodontic molar band using Nd : YAG laser in vitro. A freshly extracted human third molar with eliminated pulpal tissues was used. J-type thermocouple wire was positioned in the pulp chamber. A conductor gel was used in the transferring of outside temperature changes to the thermocouple wire. An orthodontic band was applied to the molar tooth and bonded using light cured orthodontic cement. Twenty five mm length of 0.6 mm diameter orthodontic stainless steel wires was welded to the orthodontic band using Nd : YAG laser operated at 9.4 watt. Temperature variation was determined as the change from baseline temperature to the highest temperature was recorded during welding. The recorded temperature changes were between 1.8 and 6.8°C (mean: 3.3 ± 1.1°C). The reported critical 5.5°C level was exceeded in only one sample. The results of this study suggest that intraoral use of lasers holds great potential for the future of orthodontics and does not present a thermal risk. Further studies with larger samples and structural analysis are required. PMID:24550714

  14. Temperature Changes of Pulp Chamber during In Vitro Laser Welding of Orthodontic Attachments

    Directory of Open Access Journals (Sweden)

    Eren İşman

    2014-01-01

    Full Text Available The use of lasers has been suggested for orthodontists to fabricate or repair orthodontic appliances by welding metals directly in the mouth. This work aimed to evaluate the temperature changes in the pulp chamber during welding of an orthodontic wire to an orthodontic molar band using Nd : YAG laser in vitro. A freshly extracted human third molar with eliminated pulpal tissues was used. J-type thermocouple wire was positioned in the pulp chamber. A conductor gel was used in the transferring of outside temperature changes to the thermocouple wire. An orthodontic band was applied to the molar tooth and bonded using light cured orthodontic cement. Twenty five mm length of 0.6 mm diameter orthodontic stainless steel wires was welded to the orthodontic band using Nd : YAG laser operated at 9.4 watt. Temperature variation was determined as the change from baseline temperature to the highest temperature was recorded during welding. The recorded temperature changes were between 1.8 and 6.8°C (mean: 3.3 ± 1.1°C. The reported critical 5.5°C level was exceeded in only one sample. The results of this study suggest that intraoral use of lasers holds great potential for the future of orthodontics and does not present a thermal risk. Further studies with larger samples and structural analysis are required.

  15. Removal of root filling materials.

    LENUS (Irish Health Repository)

    Duncan, H.F. Chong, B.S.

    2011-05-01

    Safe, successful and effective removal of root filling materials is an integral component of non-surgical root canal re-treatment. Access to the root canal system must be achieved in order to negotiate to the canal terminus so that deficiencies in the original treatment can be rectified. Since a range of materials have been advocated for filling root canals, different techniques are required for their removal. The management of commonly encountered root filling materials during non-surgical re-treatment, including the clinical procedures necessary for removal and the associated risks, are reviewed. As gutta-percha is the most widely used and accepted root filling material, there is a greater emphasis on its removal in this review.

  16. Gas-filled double glazing

    Energy Technology Data Exchange (ETDEWEB)

    Goesele, K.; Schuele, W.; Lakatos, B.

    1982-01-01

    On the basis of the results of experiments the sonar and thermal properties of insulated double glazing filled with gas are tested. The sound insulation properties of double glazing can be improved by introducing a gas of a heavy specific weight, such as CO/sub 2/ or SF/sub 6/ into the hollow space. Even gases with a light specific weight produce an improvement in sound insulation; light gases diffuse outwards much more rapidly, however, and can thus be eliminated for practical purposes. The combination of a gas-filled space between the panes and the use of sufficiently heavy compound panes were tested. The thermal properties of insulated double glazing filled with specifically heavy gas gave favourable results with a lower heat transition coefficient. The use of gas to fill double glazing has a particularly favourable effect if the panes are given a heat-reflecting coating in synthetic frames.

  17. Evacuation from smoke filled corridors

    NARCIS (Netherlands)

    Janse, E.W.; Leur, P.H.E. van de; Oerle, N.J. van

    1998-01-01

    underpinning compartmentation requirements in the Dutch regulations is that people can and will go through 30 m of smoke filled space. The hypothesis leads to the requirement that corridors are divided in compartments with a maximum length of 30 meters.

  18. Novel Wiring Technologies for Aerospace Applications

    Science.gov (United States)

    Gibson, Tracy L.; Parrish, Lewis M.

    2014-01-01

    Because wire failure in aerospace vehicles could be catastrophic, smart wiring capabilities have been critical for NASA. Through the years, researchers at Kennedy Space Center (KSC) have developed technologies, expertise, and research facilities to meet this need. In addition to aerospace applications, NASA has applied its knowledge of smart wiring, including self-healing materials, to serve the aviation industry. This webinar will discuss the development efforts of several wiring technologies at KSC and provide insight into both current and future research objectives.

  19. Further Studies Of Hot-Wire Anemometry

    Science.gov (United States)

    Mckenzie, Robert; Logan, Pamela; Bershader, Daniel

    1990-01-01

    Report discusses factors affecting readings of hot-wire anemometer in turbulent supersonic boundary layer. Represents extension of work described in "Hot-Wire Anemometry Versus Laser-Induced Fluorescence" (ARC-11802). Presents theoretical analysis of responses of hot-wire probe to changes in flow; also compares measurements by hot-wire probe with measurements of same flows by laser-induced fluorescence (LIF).

  20. Different mechanical properties in Seldinger guide wires

    Directory of Open Access Journals (Sweden)

    Wolfram Schummer

    2015-01-01

    Full Text Available Background and Aims: Most central venous catheters are placed using Seldinger guide wires. EN ISO 11070 is the guideline for testing guide wire flexing performance and tensile strength, and we can safely assume that guide wires in use meet these requirements. Unfortunately, EN ISO 11070 guidelines do not reflect the clinical requirements and we continue to see mechanical failures and their associated complications. Material and Methods: This in vitro study was performed in an accredited laboratory. With regard to flexing, we: (1 Established the minimum flexing performance needed to meet clinical requirements, (2 developed flexing performance tests which mimic clinical requirement, and (3 evaluated the mechanical properties of various guide wires relative to these requirements. With regard to tensile strength, we used the testing method prescribed in ISO 11070, but did not end the test at 5 Newton (N. We continued until the guide wire was damaged, or we reached maximum tractive force. We then did a wire-to-wire comparison. We examined two basic wire constructions, monofil and core and coil. Results: Tensile strength: All wires tested, except one, met EN ISO 11070 requirements for 5 N tensile strength. The mean of the wire types tested ranged from 15.06 N to 257.76 N. Flexing performance: None of the wires kinked. The monofil had no evidence of bending. Two core/coil wires displayed minor bending (angle 1.5°. All other wires displayed bending angles between 22.5° and 43.0°. Conclusion: We recommend that: (1 Clinicians use guide wires with high-end mechanical properties, (2 EN ISO 11070 incorporate our flexing test into their testing method, raise the flexing requirement to kink-proof, (3 and raise the tensile strength requirement to a minimum of 30 N, and (3 all manufacturers and suppliers be required to display mechanical properties of all guide wire, and guide wire kits sold.

  1. "Flat-Fish" Vacuum Chamber

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The picture shows a "Flat-Fish" vacuum chamber being prepared in the ISR workshop for testing prior to installation in the Split Field Magnet (SFM) at intersection I4. The two shells of each part were hydroformed from 0.15 mm thick inconel 718 sheet (with end parts in inconel 600 for easier manual welding to the arms) and welded toghether with two strips which were attached by means of thin stainless steel sheets to the Split Field Magnet poles in order to take the vertical component of the atmospheric pressure force. This was the thinnest vacuum chamber ever made for the ISR. Inconel material was chosen for its high elastic modulus and strenght at chamber bake-out temperature. In this picture the thin sheets transferring the vertical component of the atmosferic pressure force are attached to a support frame for testing. See also 7712182, 7712179.

  2. Impedances of Laminated Vacuum Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Burov, A.; Lebedev, V.; /Fermilab

    2011-06-22

    First publications on impedance of laminated vacuum chambers are related to early 70s: those are of S. C. Snowdon [1] and of A. G. Ruggiero [2]; fifteen years later, a revision paper of R. Gluckstern appeared [3]. All the publications were presented as Fermilab preprints, and there is no surprise in that: the Fermilab Booster has its laminated magnets open to the beam. Being in a reasonable mutual agreement, these publications were all devoted to the longitudinal impedance of round vacuum chambers. The transverse impedance and the flat geometry case were addressed in more recent paper of K. Y. Ng [4]. The latest calculations of A. Macridin et al. [5] revealed some disagreement with Ref. [4]; this fact stimulated us to get our own results on that matter. Longitudinal and transverse impendances are derived for round and flat laminated vacuum chambers. Results of this paper agree with Ref. [5].

  3. The CLAS drift chamber system

    CERN Document Server

    Mestayer, M D; Asavapibhop, B; Barbosa, F J; Bonneau, P; Christo, S B; Dodge, G E; Dooling, T; Duncan, W S; Dytman, S A; Feuerbach, R; Gilfoyle, G P; Gyurjyan, V; Hicks, K H; Hicks, R S; Hyde-Wright, C E; Jacobs, G; Klein, A; Klein, F J; Kossov, M; Kuhn, S E; Magahiz, R A; Major, R W; Martin, C; McGuckin, T; McNabb, J; Miskimen, R A; Müller, J A; Niczyporuk, B B; O'Meara, J E; Qin, L M; Raue, B A; Robb, J; Roudot, F; Schumacher, R A; Tedeschi, D J; Thompson, R A; Tilles, D; Tuzel, W; Vansyoc, K; Vineyard, M F; Weinstein, L B; Wilkin, G R; Yegneswaran, A; Yun, J

    2000-01-01

    Experimental Hall B at Jefferson Laboratory houses the CEBAF Large Acceptance Spectrometer, the magnetic field of which is produced by a superconducting toroid. The six coils of this toroid divide the detector azimuthally into six sectors, each of which contains three large multi-layer drift chambers for tracking charged particles produced from a fixed target on the toroidal axis. Within the 18 drift chambers are a total of 35,148 individually instrumented hexagonal drift cells. The novel geometry of these chambers provides for good tracking resolution and efficiency, along with large acceptance. The design and construction challenges posed by these large-scale detectors are described, and detailed results are presented from in-beam measurements.

  4. One century of Kirschner wires and Kirschner wire insertion techniques : A historical review

    NARCIS (Netherlands)

    Franssen, Bas B. G. M.; Schuurman, Arnold H.; Van der Molen, Aebele Mink; Kon, Moshe

    2010-01-01

    A century ago, in 1909, Martin Kirschner (1879-942) introduced a smooth pin, presently known as the Kirschner wire (K-wire). The K-wire was initiallly used for skeletal traction and is now currently used for many different goals. The development of the K-wire and its insertion devices were mainly in

  5. Getting "Wired" for McLuhan's Cyberculture.

    Science.gov (United States)

    McMurdo, George

    1995-01-01

    Examines the introduction of the computing magazine, "Wired", into the United Kingdom's (UK) market. Presents conversations with the founder and editorial staff of the UK edition, and discusses the accessibility of "Wired" via the World Wide Web. Describes 10 articles from United States "Wired" back-issues and…

  6. Generalized additional boundary conditions for wire media

    Energy Technology Data Exchange (ETDEWEB)

    Maslovski, Stanislav I; Morgado, Tiago A; Silveirinha, Mario G [Departamento de Engenharia Electrotecnica, Instituto de Telecomunicacoes, Universidade de Coimbra, Polo II, 3030-290 Coimbra (Portugal); Kaipa, Chandra S R; Yakovlev, Alexander B, E-mail: stas@co.it.p [Department of Electrical Engineering, University of Mississippi, University, MS 38677-1848 (United States)

    2010-11-15

    We generalize additional boundary conditions (ABCs) for wire media by including arbitrary wire junctions with impedance loading. Special attention is given to the conditions at the interface of two uniaxial wire media with metallic patches at the junction. The derived ABCs are validated against full-wave numerical simulations.

  7. 75 FR 4584 - Wire Decking From China

    Science.gov (United States)

    2010-01-28

    ... COMMISSION Wire Decking From China AGENCY: United States International Trade Commission. ACTION: Scheduling... retarded, by reason of subsidized and less-than-fair-value imports from China of wire decking, provided for..., producers, or exporters in China of wire decking, and that such ] products are being sold in the...

  8. 49 CFR 393.28 - Wiring systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Wiring systems. 393.28 Section 393.28 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.28 Wiring systems...

  9. Annular-Cross-Section CFE Chamber

    Science.gov (United States)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

  10. Ionization chambers for LET determination

    DEFF Research Database (Denmark)

    Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

    2010-01-01

    resolution and high sensitivity are necessary. For exact dosimetry which is done using ionization chambers (ICs), the recombination taking place in the IC has to be known. Up to now, recombination is corrected phenomenologically and more practical approaches are currently used. Nevertheless, Jaff´e's theory...... of columnar recombination was designed to model the detector efficiency of an ionization chamber. Here, we have shown that despite the approximations and simplification made, the theory is correct for the LETs typically found in clinical radiotherapy employing particles from protons to carbon ions...

  11. Ionization Chamber Measures Extreme Ultraviolet

    Science.gov (United States)

    Carlson, Robert W.

    1987-01-01

    Ionization chamber operates in nearly total photon absorption as stable, self-calibrating detector of ionizing extreme ultraviolet radiation. Working gas of instrument is neon; photoionization properties well known and readily applicable to absolute measurements. Designed for measurements of solar ultraviolet flux aboard sounding rocket, instrument used on Earth to measure ultraviolet radiation in vacuum systems. Ionization chamber collects positive neon ions and electrons produced by irradiation of neon gas by ultraviolet photons. Approximately one ion produced by each photon; consequently, photoionization current nearly proportional to photon flux.

  12. Method of fabricating a rocket engine combustion chamber

    Science.gov (United States)

    Holmes, Richard R. (Inventor); Mckechnie, Timothy N. (Inventor); Power, Christopher A. (Inventor); Daniel, Ronald L., Jr. (Inventor); Saxelby, Robert M. (Inventor)

    1993-01-01

    A process for making a combustion chamber for a rocket engine wherein a copper alloy in particle form is injected into a stream of heated carrier gas in plasma form which is then projected onto the inner surface of a hollow metal jacket having the configuration of a rocket engine combustion chamber is described. The particles are in the plasma stream for a sufficient length of time to heat the particles to a temperature such that the particles will flatten and adhere to previously deposited particles but will not spatter or vaporize. After a layer is formed, cooling channels are cut in the layer, then the channels are filled with a temporary filler and another layer of particles is deposited.

  13. Differences in CASA output according to the chamber type when analyzing frozen-thawed bull sperm.

    Science.gov (United States)

    Ibănescu, Iulian; Leiding, Claus; Ciornei, Ştefan Gregore; Roșca, Petru; Sfartz, Ioana; Drugociu, Dan

    2016-03-01

    As demonstrated by some authors, the type of analyzing chamber can greatly influence the results of computer-assisted sperm analysis (CASA). This study aimed to compare three of the disposable chamber types currently available on the market and to determine whether the CASA output may be significantly different among them. The semen from five Fleckvieh bulls was analyzed by CASA using three different disposable chambers: Leja (20μm), MofA (20μm) and Minitube (20μm), at three different time points: immediately after filling the chamber, at 6min, and also at 12min after filling. Sperm concentration was also determined using the Nucleocounter® NC-100™ device and the hemocytometer as standard methods. The results showed higher values in terms of total and progressive sperm motility for MofA compared to the other two chambers immediately after filling (pCASA only when the other methods are not available. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Practical aspects of MR imaging in the presence of conductive guide wires.

    Science.gov (United States)

    Tong, Natalie; Shmatukha, Andriy; Asmah, Peter; Stainsby, Jeffrey

    2010-01-07

    Various aspects of RF-induced heating of guide wires during their MRI guidance have been investigated in the past. However, the previous works focused on inducing tip heating in either fully immersed or tip-immersed (and otherwise free) wires of impractical lengths in small phantoms. This study simulates real clinical conditions using a product guide wire and a same-length conductive wire partially inserted into a torso-size phantom filled with saline solution. The purpose was to identify potential safety concerns relevant to real clinical applications, as opposed to identifying the worst-case heating scenario. Significant heating occurred at the insertion point, independent of tip heating, with a strong correlation with excitation frequency-dependent imaging parameters. Heat transfer through the wire was also demonstrated to be a safety concern. From these experiments, we have been able to demonstrate additional impacting factors that increase the complexity of safety considerations for the use of conductive guide wires during MR imaging. Safety under a particular set of conditions does not imply safety in all possible conditions that can be encountered during real MRI-guided interventions.

  15. On-chip pressure sensor using single-layer concentric chambers.

    Science.gov (United States)

    Tsai, Chia-Hung Dylan; Kaneko, Makoto

    2016-03-01

    A vision-based on-chip sensor for sensing local pressure inside a microfluidic device is proposed and evaluated in this paper. The local pressure is determined from the change of color intensity in the sensing chamber which is pre-filled with colored fluid. The working principle of the sensor is based on polydimethylsiloxane deformation. The pressure at the point of interest is guided into a deformation chamber, where the structural stiffness is softened by chamber geometry, and thus, the chamber deforms as a result of pressure changes. Such deformation is transmitted to the sensing chamber, a same-layer concentric inside the deformation chamber. The deformation in the sensing chamber causes the colored fluid flowing in or out the chamber and leads to different color intensity from the top view through a microscope. Experimental evaluations on static and dynamic responses by regulated input pressures were conducted. The correlation in static response is 0.97 while the dynamic responses are successfully observed up to 16 Hz. The greatest advantage is that the local pressure can be directly seen without any additional hardware or electricity. The whole sensor is on a single-layer microfluidic design, so that the fabrication is simple, consistent, and low-cost. The single-layer design also provides the convenience of easy integration for existing microfluidic systems.

  16. Energy Deposition in a Septum Wire

    CERN Document Server

    Ferioli, G; Knaus, P; Koopman, J; CERN. Geneva. SPS and LHC Division

    2001-01-01

    The present note describes a machine development (MD) aimed to confirm experimentally the need for protection of the extraction wire septum ZS in SPS long straight section LSS6 during LHC operation. Single wires identical to the ones mounted on the extraction septum were fixed on a fast wire scanner and put into the beam path. The beam heated the wire until it broke after a measured number of turns. The maximum single shot intensity the septum wires could withstand was thus calculated and compared with simulation results.

  17. Directional growth of polypyrrole and polythiophene wires

    Science.gov (United States)

    Thapa, Prem S.; Yu, Deok Jin; Wicksted, James P.; Hadwiger, Jeffrey A.; Barisci, Joseph N.; Baughman, Ray H.; Flanders, Bret N.

    2009-01-01

    This work establishes an innovative electrochemical approach to the template-free growth of conducting polypyrrole and polythiophene wires along predictable interelectrode paths up to 30 μm in length. These wires have knobby structures with diameters as small as 98 nm. The conductivity of the polypyrrole wires is 0.5±0.3 S cm-1; that of the polythiophene wires is 7.6±0.8 S cm-1. Controlling the growth path enables fabrication of electrode-wire-target assemblies where the target is a biological cell in the interelectrode gap. Such assemblies are of potential use in cell stimulation studies.

  18. Clinical bending of nickel titanium wires

    Directory of Open Access Journals (Sweden)

    Stephen Chain

    2015-01-01

    Full Text Available Since the evolution and the involvement of Nickel Titanium wires in the field of Orthodontics. The treatment plan has evolved with the use of low force Nickel Titanium wires. Because of their high springback, low stiffness, they are the key initial wires in leveling and alignment but have poor formability. Since poor formability limits its ability to create variable arch forms thus; limits the form of treatment. We have devised a method to bend the Nickel Titanium wires to help in our inventory but also customized the wire according to the treatment.

  19. DELPHI's Ring Imaging Cherenkov Chamber

    CERN Multimedia

    1989-01-01

    The hundreds of mirrors around this Ring Imaging Cherenkov Chamber reflect cones of light created by fast moving particles to a detector. The velocity of a particle can be measured by the size of the ring produced on the detector. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  20. A dual deformable reverberation chamber

    NARCIS (Netherlands)

    Leferink, Frank

    2010-01-01

    There is disclosed an arrangement for measuring the effectiveness of a shielding material against electromagnetic fields. The arrangement comprises a first and a second reverberation chamber sharing a common wall. The common wall is partly made of the shielding material. A first antenna is arranged

  1. Bubble chamber: colour enhanced tracks

    CERN Multimedia

    1998-01-01

    This artistically-enhanced image of real particle tracks was produced in the Big European Bubble Chamber (BEBC). Liquid hydrogen is used to create bubbles along the paths of the particles as a piston expands the medium. A magnetic field is produced in the detector causing the particles to travel in spirals, allowing charge and momentum to be measured.

  2. Testing an hydrogen streamer chamber

    CERN Multimedia

    1975-01-01

    A 2x10 cm gap streamer chamber, 35x55 cm2 in surface, was built and tested at CERN. Good tracks of cosmic rays were obtained up to atmospheric pressure, see F. Rohrbach et al, CERN-LAL (Orsay) Collaboration, Nucl. Instr. Methods 141 (1977) 229. Michel Cathenoz stand on the center.

  3. Effect of chamber characteristics, loading and analysis time on motility and kinetic variables analysed with the CASA-mot system in goat sperm.

    Science.gov (United States)

    Del Gallego, R; Sadeghi, S; Blasco, E; Soler, C; Yániz, J L; Silvestre, M A

    2017-02-01

    Several factors unrelated to the semen samples could be influencing in the sperm motility analysis. The aim of the present research was to study the effect of four chambers with different characteristics, namely; slide-coverslip, Spermtrack, ISAS D4C10, and ISAS D4C20 on the sperm motility. The filling procedure (drop or capillarity) and analysis time (0, 120 and 240s), depth of chamber (10 or 20μm) and field on motility variables were analysed by use of the CASA-mot system in goat sperm. Use of the drop-filling chambers resulted in greater values than capillarity-filling chambers for all sperm motility and kinetic variables, except for LIN (64.5% compared with 56.3% of motility for drop- and capillarity-filling chambers respectively, PCASA-mot system with a drop-loaded chamber within 2min after filling the chamber. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Composite wire plasma formation and evolution

    Energy Technology Data Exchange (ETDEWEB)

    Spielman, R.B.

    2000-01-01

    The detailed understanding of the formation and evolution of plasma from rapidly heated metallic wires is a long-standing challenge in the field of plasma physics and in exploding wire engineering. This physical process is made even more complicated if the wire material is composed of a number of individual layers. The authors have successfully developed both optical and x-ray backlighting diagnostics. In particular, the x-ray backlighting technique has demonstrated the capability for quantitative determination of the plasma density over a wide range of densities. This diagnostic capability shows that the process of plasma formation is composed of two separate phases: first, current is passed through a cold wire and the wire is heated ohmically, and, second, the heated wire evolves gases that break down and forms a low-density plasma surrounding the wire.

  5. Precision Muon Tracking at Future Hadron Colliders with sMDT Chambers

    CERN Document Server

    INSPIRE-00218368; Kroha, Hubert; Müller, Felix; Nowak, Sebastian; Richter, Robert

    2016-01-01

    Small-diameter muon drift tube (sMDT) chambers are a cost-effective technology for high-precision muon tracking. The rate capability of the sMDT chambers has been extensively tested at the Gamma Irradiation Facility at CERN in view of expected rates at future high-energy hadron colliders. Results show that it fulfills the requirements over most of the acceptance of muon detectors. The optimization of the read-out electronics to further increase the rate capability of the detectors is discussed. Chambers of this type are under construction for upgrades of the muon spectrometer of the ATLAS detector at high LHC luminosities. Design and construction procedures have been optimized for mass production while providing a precision of better than 10 micrometers in the sense wire positions and the mechanical stability required to cover large areas.

  6. A ZigBee-based wireless system for monitoring vital signs in hyperbaric chambers: Technical report.

    Science.gov (United States)

    Carmona, Cristian; Alorda, Bartomeu; Gracia, Luis; Perez-Vidal, Carlos; Salinas, Antonio

    2017-01-01

    This paper presents the replacement of a traditional wired communication link of the hyperbaric chambers with a wireless ZigBee-based system. This move allows a reduction in the costs of seals capable of withstanding the internal pressures and gives rise to a more versatile system. The new system is able to capture and process individual vital signs like the electrocardiography signal, and other analog sources, sending the data to an external computer and allowing analysis, representation and sharing with medical staff. This system solves such problems as the attenuation of the signal produced by the metal walls of the hyperbaric chamber and has a coverage area large enough to manage up to six patients with an effective data rate conversion of 2kHz. Furthermore, a battery-based and multiparameter platform is designed for multipatient hyperbaric chambers. Copyright© Undersea and Hyperbaric Medical Society.

  7. LHCb: Performance of the fourgap LHCb Muon Chambers tested with cosmic rays

    CERN Multimedia

    Pinci, D

    2007-01-01

    The LHCb Muon System is composed of five detection stations (M1M5)mainly equipped with a total of 1368 MultiWire Proportional Chambers (MWPC). MWPCs need to ensure a high detection efficiency, a fast response and a good space resolution. We present here the results of detailed studies of the performance of different fourgap chambers, completely equipped with the final FrontEnd Electronics, measured with cosmic rays. Aspects such as time resolution, hit multiplicity and time and space structure of the crosstalk hits were measured. For the first time, both types of chambers, those with anodewirereadout and those with cathodepadreadout, were tested and the results are compared. Results hereby obtained will be used to individuate the optimal working conditions of the apparatus and to achieve a more realistic detector description in the LHCb Monte Carlo simulation.

  8. Field emission of GaN-filled carbon nanotubes: high and stable emission current.

    Science.gov (United States)

    Liao, L; Li, J C; Liu, C; Xu, Z; Wang, W L; Liu, S; Bai, X D; Wang, E G

    2007-03-01

    Field electron emission of GaN-filled carbon nanotubes, grown by microwave plasma enhanced chemical vapor deposition, was investigated. The detailed structural characterization shows that the filled nanotube has a GaN-core/C-shell structure, in which the GaN wire corresponds to a wurtzite structure. The field emission properties of the GaN-filled carbon nanotubes have been achieved with high and stable emission current. It is attributed to the unique cable-like structure, which makes the GaN-core/C-shell composite mechanically solid and chemically stable. This study suggests the GaN-filled carbon nanotube as an ideal candidate for future high-current and high-power field emitter applications.

  9. Sequential push-pull pumping mechanism for washing and evacuation of an immunoassay reaction chamber on a microfluidic CD platform.

    Directory of Open Access Journals (Sweden)

    Tzer Hwai Gilbert Thio

    Full Text Available A centrifugal compact disc (CD microfluidic platform with reservoirs, micro-channels, and valves can be employed for implementing a complete immunoassay. Detection or biosensor chambers are either coated for immuno-interaction or a biosensor chip is inserted in them. On microfluidic CDs featuring such multi-step chemical/biological processes, the biosensor chamber must be repeatedly filled with fluids such as enzymes solutions, buffers, and washing solutions. After each filling step, the biosensor chamber needs to be evacuated by a passive siphoning process to prepare it for the next step in the assay. However, rotational speed dependency and limited space on a CD are two big obstacles to performing such repetitive filling and siphoning steps. In this work, a unique thermo-pneumatic (TP Push-Pull pumping method is employed to provide a superior alternative biosensor chamber filling and evacuation technique. The proposed technique is demonstrated on two CD designs. The first design features a simple two-step microfluidic process to demonstrate the evacuation technique, while the second design shows the filling and evacuation technique with an example sequence for an actual immunoassay. In addition, the performance of the filling and evacuation technique as a washing step is also evaluated quantitatively and compared to the conventional manual bench top washing method. The two designs and the performance evaluation demonstrate that the technique is simple to implement, reliable, easy to control, and allows for repeated push-pulls and thus filling and emptying of the biosensor chamber. Furthermore, by addressing the issue of rotational speed dependency and limited space concerns in implementing repetitive filling and evacuation steps, this newly introduced technique increases the flexibility of the microfluidic CD platform to perform multi-step biological and chemical processes.

  10. Investigation of Momentum Resolution in Straight vs Bent Large End-Cap Chambers

    CERN Document Server

    Levin, D S

    1999-01-01

    We report on a calculation of momentum resolution for muons incident on the large end-cap chambers. The impact on the resolution of two chamber designs was evaluated: Those constructed with straight drift tubes are compared to the ATLAS baseline design in which chambers are bent such that tube axes conform to the catenary of their respective anode wires. The analysis was performed using the GARFIELD program to calculate drift tube time-to-space functions. ATLAS muon system code packages LHCTOR and MUONBOX were used to generate tracks, hits and momentum reconstruction. We find that, for straight tube chambers compared to bent ones, the overall degradation in momentum resolution, averaged over all of the largest of the so called large end-cap chambers (EML4-5 and EOL3 in the pseudo-rapidity range$1.02 < \\eta <1.49$), is very small for muon transverse momentum $P_t = 500 $ Gev and negligible for $P_t \\le 100 $ Gev. When the intermediate large end-cap chambers (EEL1 and EEL2) are considered no momentum degr...

  11. Preparation of uncladded YBCO wires

    Science.gov (United States)

    Grader, G.; Cadoche, L.; Shter, G.

    1993-04-01

    Wires of YBCO, 1-5 mm in diameter, have been obtained by extrusion of an oxalate derived powder mixed with polyvinyl butyral (PVB) and two phthalate plasticizers. The densification and transport properties of the wires were investigated at various organic loading conditions. For YBCO powder prepared by oxalate coprecipitation and calcined at 930°C, the maximal strength, relative density and Jc were 20MPa, 92% and 400A/cm 2, respectively. Results show that after a 4-hour sintering at 955°C the tensile strength, density, and Jc are all maximized at a binder content of 3-4 wt.%. The loading of up to 10 wt.% dibutyl phthalate (DBP) plasticizer (in the binder) has little effect on the properties. Beyond this loading a drastic drop in Jc is observed. The densification was very poor for sinterings below 950°C, which was reflected by a lower critical current.

  12. Growing and Analyzing Biofilms in Flow Chambers

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Sternberg, Claus

    2011-01-01

    This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic...... conditions, and the environment can be carefully controlled and easily changed. The protocols in this unit include construction of the flow chamber and the bubble trap, assembly and sterilization of the flow chamber system, inoculation of the flow chambers, running of the system, image capture and analysis...

  13. Chamber dynamic research with pulsed power

    Energy Technology Data Exchange (ETDEWEB)

    PETERSON,ROBERT R.; OLSON,CRAIG L.; RENK,TIMOTHY J.; ROCHAU,GARY E.; SWEENEY,MARY ANN

    2000-05-15

    In Inertial Fusion Energy (IFE), Target Chamber Dynamics (TCD) is an integral part of the target chamber design and performance. TCD includes target output deposition of target x-rays, ions and neutrons in target chamber gases and structures, vaporization and melting of target chamber materials, radiation-hydrodynamics in target chamber vapors and gases, and chamber conditions at the time of target and beam injections. Pulsed power provides a unique environment for IFE-TCD validation experiments in two important ways: they do not require the very clean conditions which lasers need and they currently provide large x-ray and ion energies.

  14. Development of a Micro Pixel Chamber for the ATLAS Upgrade

    CERN Document Server

    Ochi, Atsuhiko; Komai, Hidetoshi; Edo, Yuki; Yamaguchi, Takahiro

    2012-01-01

    The Micro Pixel Chamber (μ-PIC) is being developed a sacandidate for the muon system of the ATLAS detector for upgrading in LHC experiments. The μ-PIC is a micro-pattern gaseous detector that doesn’t have floating structure such as wires, mesh, or foil. This detector can be made by printed-circuit-board (PCB) technology, which is commercially available and suited for mass production. Operation tests have been performed under high flux neutrons under similar conditions to the ATLAS cavern. Spark rates are measured using several gas mixtures under 7 MeV neutron irradiation, and good properties were observed using neon, ethane, and CF4 mixture of gases.Using resistive materials as electrodes, we are also developing a new μ-PIC, which is not expected to damage the electrodes in the case of discharge sparks.

  15. Paleovalley fills: Trunk vs. tributary

    Science.gov (United States)

    Kvale, E.P.; Archer, A.W.

    2007-01-01

    A late Mississippian-early Pennsylvanian eustatic sea level drop resulted in a complex lowstand drainage network being eroded across the Illinois Basin in the eastern United States. This drainage system was filled during the early part of the Pennsylvanian. Distinct differences can be recognized between the trunk and tributary paleovalley fills. Fills preserved within the trunk systems tend to be fluvially dominated and consist of bed-load deposits of coarse- to medium-grained sandstone and conglomerate. Conversely, the incised valleys of tributary systems tend to be filled with dark mudstone, thinly interbedded sandstones, and mudstones and siltstones. These finer grained facies exhibit marine influences manifested by tidal rhythmites, certain traces fossils, and macro- and microfauna. Examples of tributary and trunk systems, separated by no more than 7 km (4.3 mi) along strike, exhibit these styles of highly contrasting fills. Useful analogs for understanding this Pennsylvanian system include the Quaternary glacial sluiceways present in the lower Ohio, White, and Wabash river valleys of Indiana (United States) and the modern Amazon River (Brazil). Both the Amazon River and the Quaternary rivers of Indiana have (or had) trunk rivers that are (were) dominated by large quantities of bed load relative to their tributaries. The trunk valley systems of these analogs aggraded much more rapidly than their tributary valleys, which evolved into lakes because depositional rates along the trunk are (were) so high that the mouths of the tributaries have been dammed by bed-load deposits. These Holocene systems illustrate that sediment yields can significantly influence the nature of fill successions within incised valleys independent of rates of sea level changes or proximity to highstand coastlines. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.

  16. Thermoprocessing and wire drawing behaviour of ultra high strength steel wires

    Directory of Open Access Journals (Sweden)

    S.S. Bargujer

    2016-09-01

    Full Text Available The thermo-processing of piano wire rods is carried out in the lead bath. This experimentation is carried out under industrial conditions. The investigation is done to examine the effect of austenitic time, lead bath time and wire diameter on mechanical properties of lead patented wire. The Taguchi technique is adopted for optimization of thermo-processing of hypereutectoid steel wires. The lead patented wire of diameter 7.00 mm is cold drawn in a sequence of conical converging dies. The best pass schedule of lead patented piano wire is obtained by optimizing the ultimate tensile strength and torsion strength of cold drawn wire. The characterization of wire drawing behaviour of lead patented wires is carried out using optical microscopy, scanned electron microscopy and X-ray diffraction analysis techniques.

  17. SpaceWire Satellite Usage

    Science.gov (United States)

    2013-03-01

    Figure 1. SpaceWire Topologies 309 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of...RS422 Hosted Payload data interface Joint  Architeccture  Standards Sandia,  LANL control interface; backplane sRIO, PCIe Common standards for joint

  18. QENS investigation of filled rubbers

    Energy Technology Data Exchange (ETDEWEB)

    Triolo, A.; Lechner, R.E.; Desmedt, A.; Pieper, J. [CNR - Istituto per i Processi Chimico-Fisici, sez. Messina, Via La Farina 237, 98123 Messina (Italy); Lo Celso, F.; Triolo, R. [Dip. Chimica Fisica, V. le delle Scienze, Parco d' Orleans, Padiglione 17, Universita di Palermo, 90128 Palermo (Italy); Negroni, F. [Pirelli Pneumatici S.p.A, V. le Sarca 222, 20126 Milano (Italy); Arrighi, V.; Qian, H. [Chemistry School of Engineering and Physical Sciences, Heriot-Watt University, EH14 4AS Edinburgh (United Kingdom); Frick, B. [Institut Laue-Langevin, 6, rue Jules Horowitz, BP 156, 38042 Grenoble, Cedex 9 (France)

    2002-07-01

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface. (orig.)

  19. QENS investigation of filled rubbers

    CERN Document Server

    Triolo, A; Desmedt, A; Pieper, J K; Lo Celso, F; Triolo, R; Negroni, F; Arrighi, V; Qian, H; Frick, B

    2002-01-01

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface. (orig.)

  20. QENS investigation of filled rubbers

    Science.gov (United States)

    Triolo, A.; Lo Celso, F.; Negroni, F.; Arrighi, V.; Qian, H.; Lechner, R. E.; Desmedt, A.; Pieper, J.; Frick, B.; Triolo, R.

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface.

  1. Gas-Filled Capillary Model

    Science.gov (United States)

    Steinhauer, L. C.; Kimura, W. D.

    2006-11-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration — Laser Wakefield (STELLA-LW) experiment.

  2. Concept of porous wire anemometer

    Energy Technology Data Exchange (ETDEWEB)

    Afgan, N.H.; Pereira, J.C. [Inst. Superior Tecnico, Lisbon (Portugal); Leontiev, A.I.; Puzach, S.V. [Moscow Technical Univ. (Russian Federation)

    1997-05-01

    The paper presents a new scheme of the anemometer sensing element for the gas mean and fluctuation velocity measurement. The sensing element is a porous tube with gas suction through porous tube wall. The outside surface of the porous tube is at the gas temperature. The analysis, based on the heat balance at steady and unsteady state is performed in order to define the sensitivity and time constant of the porous sensing element. Two cases are considered, namely, the constant current and constant temperature anemometer. Comparison is made with the solid wire anemometer and shown that the proposed porous sensing element can have sensitivity four times higher than the standard hot wire anemometer with the same geometrical dimensions. With the respective selection of the physical properties of the sensing element, it could be possible to obtain higher frequency range of the measurement. Particular attention is devoted to the low gas velocity measurement. It is recognized that the minimum gas velocity to be measured with the solid hot wire anemometer is determined by the local heat transfer coefficient. For the low gas velocity, it was proved that the minimum is around .20 cm/sec. The proposed concept of the sensing element can be used for the very low velocity measurement due to the higher sensitivity obtained by the porous sensing element.

  3. Application of the two-dose-rate method for general recombination correction for liquid ionization chambers in continuous beams

    Science.gov (United States)

    Andersson, Jonas; Tölli, Heikki

    2011-01-01

    A method to correct for the general recombination losses for liquid ionization chambers in continuous beams has been developed. The proposed method has been derived from Greening's theory for continuous beams and is based on measuring the signal from a liquid ionization chamber and an air filled monitor ionization chamber at two different dose rates. The method has been tested with two plane parallel liquid ionization chambers in a continuous radiation x-ray beam with a tube voltage of 120 kV and with dose rates between 2 and 13 Gy min-1. The liquids used as sensitive media in the chambers were isooctane (C8H18) and tetramethylsilane (Si(CH3)4). The general recombination effect was studied using chamber polarizing voltages of 100, 300, 500, 700 and 900 V for both liquids. The relative standard deviation of the results for the collection efficiency with respect to general recombination was found to be a maximum of 0.7% for isooctane and 2.4% for tetramethylsilane. The results are in excellent agreement with Greening's theory for collection efficiencies over 90%. The measured and corrected signals from the liquid ionization chambers used in this work are in very good agreement with the air filled monitor chamber with respect to signal to dose linearity.

  4. Application of the two-dose-rate method for general recombination correction for liquid ionization chambers in continuous beams

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Jonas; Toelli, Heikki, E-mail: jonas.andersson@radfys.umu.se [Department of Radiation Sciences, Radiation Physics, Umeaa University, SE-901 85 Umeaa (Sweden)

    2011-01-21

    A method to correct for the general recombination losses for liquid ionization chambers in continuous beams has been developed. The proposed method has been derived from Greening's theory for continuous beams and is based on measuring the signal from a liquid ionization chamber and an air filled monitor ionization chamber at two different dose rates. The method has been tested with two plane parallel liquid ionization chambers in a continuous radiation x-ray beam with a tube voltage of 120 kV and with dose rates between 2 and 13 Gy min{sup -1}. The liquids used as sensitive media in the chambers were isooctane (C{sub 8}H{sub 18}) and tetramethylsilane (Si(CH{sub 3}){sub 4}). The general recombination effect was studied using chamber polarizing voltages of 100, 300, 500, 700 and 900 V for both liquids. The relative standard deviation of the results for the collection efficiency with respect to general recombination was found to be a maximum of 0.7% for isooctane and 2.4% for tetramethylsilane. The results are in excellent agreement with Greening's theory for collection efficiencies over 90%. The measured and corrected signals from the liquid ionization chambers used in this work are in very good agreement with the air filled monitor chamber with respect to signal to dose linearity.

  5. Wire-Cell Tomographic Event Reconstruction for large LArTPCs

    Science.gov (United States)

    Qian, Xin; Viren, Brett; Zhang, Chao; Wire-Cell Team

    2016-03-01

    Event reconstruction is one of the most challenging tasks in analyzing the data from current and future large liquid argon time projection chambers (LArTPCs). The performance of the event reconstruction holds the key to many potential future discoveries with the LArTPC technology including i) searching for new CP violation in the leptonic sector, ii) determining the neutrino mass hierarchy, and iii) searching for additional light (sterile) neutrino species. In this talk, we introduce a new reconstruction method: Wire-Cell. The principle of Wire-Cell strictly follows the principle of LArTPC, that is, the same amount of ionization electrons are observed by all the wire-planes. Using both time and charge information, 3D image of the event topologies are firstly obtained. Further reconstruction steps including the clustering, tracking, and particle identifications (PID) are then directly applied to the 3D image. The principle, current status, and future development plan of Wire-Cell will be described. The results of Wire-Cell event reconstruction will be shown with an innovative web-based ``BEE'' 3D event display. This work is supported by U.S. Department of Energy, Office of Science, Office of High Energy Physics and Early Career Research program under Contract Number DE-SC0012704.

  6. Study of Neutron-Induced Ionization in Helium and Argon Chamber Gases

    CERN Document Server

    Indurthy, D; Harris, D; Kopp, S; Proga, M; Zwaska, R M

    2004-01-01

    Ion chambers used to monitor the secondary hadron and tertiary muon beam in the NuMI neutrino beamline will be exposed to background particles, including low energy neutrons produced in the beam dump. To understand these backgrounds, we have studied Helium- and Argon-filled ionization chambers exposed to intense neutron fluxes from PuBe neutron sources ($E_n=1-10$ MeV). The sources emit about 10$^8$ neutrons per second. The number of ion pairs in the chamber gas volume per incident neutron is derived. While limited in precision because of a large gamma ray background from the PuBe sources, our results are consistent with the expectation that the neutrons interact purely elastically in the chamber gas.

  7. A portable miniature anechoic chamber

    Science.gov (United States)

    Lorthioir, Jack; Gavin, Paul

    The portable miniature anechoic chamber (PMAC), a low-cost alternative to a full-size anechoic chamber, is presented. The PMAC is a miniature, enclosed, RF-tight microwave antenna range, which approximates the performance of an indoor range over the C through Ku (G through J)-band frequencies. The small footprint, four by six feet, allows for ease of movement by one person to a test site, indoors or outdoors. The PMAC can be used at I (intermediate)-level to support the operational readiness (OR) requirements of the U.S. Army, Navy or Air Force. In conjunction with the antenna test equipment (ATE), and under TPS control, it can be used for performance verification, fault detection and fault isolation. A typical application using the PMAC in this operating mode is described.

  8. Development of multiwire proportional chambers

    CERN Multimedia

    Charpak, G

    1969-01-01

    It has happened quite often in the history of science that theoreticians, confronted with some major difficulty, have successfully gone back thirty years to look at ideas that had then been thrown overboard. But it is rare that experimentalists go back thirty years to look again at equipment which had become out-dated. This is what Charpak and his colleagues did to emerge with the 'multiwire proportional chamber' which has several new features making it a very useful addition to the armoury of particle detectors. In the 1930s, ion-chambers, Geiger- Muller counters and proportional counters, were vital pieces of equipment in nuclear physics research. Other types of detectors have since largely replaced them but now the proportional counter, in new array, is making a comeback.

  9. Actuator System with Dual Chambers

    DEFF Research Database (Denmark)

    2015-01-01

    (8), the lid having a shaft opening (17) for a shaft (6) coupled to the magnetic rotor (5), wherein the magnetic rotor (5), when inserted in the translator cylinder (2), is arranged to translate a linear movement of the translator cylinder (2) into a rotational movement of the magnetic rotor by using...... magnetic flux (82) interacting between the magnetic stator and the magnetic rotor, said rotational movements is being transferred through a shaft (6), the lid (8) with a shaft opening (17) arranged for receiving the shaft (6), wherein the shaft is arranged to make both the linear and the rotational...... movement in the shaft opening (17), the lid (8) being arranged for confining the second end (15) of the translator cylinder (2), the translator cylinder confined by the lid (8) forms,when divided by the magnetic rotor (5), a first chamber (TC) with a first volume and a second chamber(BC) with a second...

  10. LEP vacuum chamber, early prototype

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The structure of LEP, with long bending magnets and little access to the vacuum chamber between them, required distributed pumping. This is an early prototype for the LEP vacuum chamber, made from extruded aluminium. The main opening is for the beam. The small channel to the right is for cooling water, to carry away the heat deposited by the synchroton radiation from the beam. The 4 slots in the channel to the left house the strip-shaped ion-getter pumps (see 7810255). The ion-getter pumps depended on the magnetic field of the bending magnets, too low at injection energy for the pumps to function well. Also, a different design was required outside the bending magnets. This design was therefore abandoned, in favour of a thermal getter pump (see 8301153 and 8305170).

  11. Actuator System with Dual Chambers

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to an actuator system with a magnetic lead screw (50), comprises a magnetic rotor (5) and a translator cylinder (2), the translator cylinder (2) comprises a magnetic stator (16), the translator cylinder (2) has a closed first end (14) and a second end confined by a lid...... (8), the lid having a shaft opening (17) for a shaft (6) coupled to the magnetic rotor (5), wherein the magnetic rotor (5), when inserted in the translator cylinder (2), is arranged to translate a linear movement of the translator cylinder (2) into a rotational movement of the magnetic rotor by using...... movement in the shaft opening (17), the lid (8) being arranged for confining the second end (15) of the translator cylinder (2), the translator cylinder confined by the lid (8) forms,when divided by the magnetic rotor (5), a first chamber (TC) with a first volume and a second chamber(BC) with a second...

  12. MPS II drift chamber system

    Energy Technology Data Exchange (ETDEWEB)

    Platner, E.D.

    1982-01-01

    The MPS II detectors are narrow drift space chambers designed for high position resolution in a magnetic field and in a very high particle flux environment. Central to this implementation was the development of 3 multi-channel custom IC's and one multi-channel hybrid. The system is deadtimeless and requires no corrections on an anode-to-anode basis. Operational experience and relevance to ISABELLE detectors is discussed.

  13. Unsteady Capillary Filling By Electrocapillarity

    Science.gov (United States)

    Kang, In Seok; Lee, Jung A.

    2016-11-01

    Unsteady filling of electrolyte solution inside a nanochannel by the electrocapillarity effect is studied. The filling rate is predicted as a function of the bulk concentration of the electrolyte, the surface potential (or surface charge density), and the cross sectional shape of the channel. Since the driving force of the flow is the electrocapillarity, it is first analyzed by using the solution of the Poisson-Boltzmann equation. From the analysis, it is found that the results for many different cross sectional shapes can be unified with good accuracy if the hydraulic radius is adopted as the characteristic length scale of the problem. Especially in the case of constant surface potential, for both limits of κh -> 0 and κh -> ∞ , it can be shown theoretically that the electrocapillarity is independent of the cross sectional shape if the hydraulic radius is the same. In order to analyze the geometric effects more systematically, we consider the regular N-polygons with the same hydraulic radius and the rectangles of different aspect ratios. Washburn's approach is then adopted to predict the filling rate of electrolyte solution inside a nanaochannel. It is found that the average filling velocity decreases as N increases in the case of regular N-polygons with the same hydraulic radius. This is because of that the regular N-polygons of the same hydraulic radius share the same inscribing circle. This work has been supported by BK21+ program.

  14. Filling in the retinal image

    Science.gov (United States)

    Larimer, James; Piantanida, Thomas

    1990-01-01

    The optics of the eye form an image on a surface at the back of the eyeball called the retina. The retina contains the photoreceptors that sample the image and convert it into a neural signal. The spacing of the photoreceptors in the retina is not uniform and varies with retinal locus. The central retinal field, called the macula, is densely packed with photoreceptors. The packing density falls off rapidly as a function of retinal eccentricity with respect to the macular region and there are regions in which there are no photoreceptors at all. The retinal regions without photoreceptors are called blind spots or scotomas. The neural transformations which convert retinal image signals into percepts fills in the gaps and regularizes the inhomogeneities of the retinal photoreceptor sampling mosaic. The filling-in mechamism plays an important role in understanding visual performance. The filling-in mechanism is not well understood. A systematic collaborative research program at the Ames Research Center and SRI in Menlo Park, California, was designed to explore this mechanism. It was shown that the perceived fields which are in fact different from the image on the retina due to filling-in, control some aspects of performance and not others. Researchers have linked these mechanisms to putative mechanisms of color coding and color constancy.

  15. Space-filling polyhedral sorbents

    Science.gov (United States)

    Haaland, Peter

    2016-06-21

    Solid sorbents, systems, and methods for pumping, storage, and purification of gases are disclosed. They derive from the dynamics of porous and free convection for specific gas/sorbent combinations and use space filling polyhedral microliths with facial aplanarities to produce sorbent arrays with interpenetrating interstitial manifolds of voids.

  16. Filling of charged cylindrical capillaries

    NARCIS (Netherlands)

    Das, Siddhartha; Chanda, Sourayon; Eijkel, J.C.T.; Tas, N.R.; Chakraborty, Suman; Mitra, Sushanta K.

    2014-01-01

    We provide an analytical model to describe the filling dynamics of horizontal cylindrical capillaries having charged walls. The presence of surface charge leads to two distinct effects: It leads to a retarding electrical force on the liquid column and also causes a reduced viscous drag force because

  17. GBO RF Anechoic Chamber & Antenna Test Range

    Data.gov (United States)

    Federal Laboratory Consortium — A shielded anechoic chamber measuring 15 by 15 by 37 feet is located in the Jansky Laboratory at Green Bank. This chamber has been outfitted as a far-field antenna...

  18. "Cut wires grating – single longitudinal wire" planar metastructure to achieve microwave magnetic resonance in a single wire

    Directory of Open Access Journals (Sweden)

    G. Kraftmakher

    2012-09-01

    Full Text Available Here we present metastructures containing cut-wire grating and a single longitudinal cut-wire orthogonal to grating’s wires. Experimental investigations at microwaves show these structures can provide strong magnetic resonant response of a single nonmagnetic cut-wire in dependence on configuration and sizes in the case when metastructures are oriented along the direction of wave propagation and cut-wires of grating are parallel to the electric field of a plane electromagnetic wave. It is suggested a concept of magnetic response based on antiparallel resonant currents excited by magnetic field of surface polaritons in many spatial LC-circuits created from cut-wire pairs of a grating and section of longitudinal cut-wire. Three separately observed resonant effects connected with grating, LC-circuits and with longitudinal cut-wire have been identified applying measurements in waveguides, cutoff waveguides and free space. To tune and mark resonance split cut-wires are loaded with varactor diodes.

  19. EFFECTS OF WIRE LAG IN WIRE ELECTRICAL DISCHARGE MACHINING (WEDM

    Directory of Open Access Journals (Sweden)

    S. K. SINHA

    2010-11-01

    Full Text Available WEDM is very useful wherever complex geometry with tight tolerances needs to be generated on hard materials. In view of modern and sophisticated technology readily available these days, the expectation of accuracy in WEDM is ever-increasing, and therefore, techniques for the improvement in WEDM must be developed. The main cause of inaccuracy is wire-lag, the cause and effect of which is described in the present work, along with a technique to obviate the problem in straight cutting. In a subsequent paper, a software approach (since the problem gets too complicated for improvement of accuracy in contour cutting is described.

  20. 21 CFR 868.5470 - Hyperbaric chamber.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hyperbaric chamber. 868.5470 Section 868.5470 Food... DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5470 Hyperbaric chamber. (a) Identification. A hyperbaric chamber is a device that is intended to increase the environmental oxygen pressure to promote...

  1. Growing and analyzing biofilms in flow chambers

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Sternberg, Claus

    2011-01-01

    This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic cond...

  2. Growing and Analyzing Biofilms in Flow Chambers

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Sternberg, Claus

    2011-01-01

    This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic cond...

  3. LEP vacuum chamber cross-section

    CERN Multimedia

    1987-01-01

    This diagram shows the layout of the vacuum chambers used at LEP, which was in operation at CERN between 1989 and 2000. Vacuum chambers are necessary in accelerators to prevent unwanted interactions that can destabilise the beam. The pump on the right sucks air out of the chamber allowing the beam to progress with minimal interactions.

  4. Simple Cloud Chambers Using Gel Ice Packs

    Science.gov (United States)

    Kamata, Masahiro; Kubota, Miki

    2012-01-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

  5. Vacuum chamber at intersection I-6

    CERN Multimedia

    1971-01-01

    The vacuum chamber at intersection region I-6, one of these where experiments in colliding-beam physics will be taking place. The "wheels" prevent the thin wall (1.5 mm) of the chamber from collapsing. The chamber is equipped with heating tapes and its wrapped in thermal insulation. Residual gas pressure at this and other similar regions is around 10_11.

  6. Electromagnetic Behaviour of Metallic Wire Structures

    CERN Document Server

    Chui, S T

    2013-01-01

    Despite the recent development and interest in the photonics of metallic wire structures, the relatively simple concepts and physics often remain obscured or poorly explained to those who do not specialize in the field. Electromagnetic Behaviour of Metallic Wire Structures provides a clear and coherent guide to understanding these phenomena without excessive numerical calculations.   Including both background material and detailed derivations of the various different formulae applied, Electromagnetic Behaviour of Metallic Wire Structures describes how to extend basic circuit theory relating to voltages, currents, and resistances of metallic wire networks to include situations where the currents are no longer spatially uniform along the wire. This lays a foundation for a deeper understanding of the many new phenomena observed in meta-electromagnetic materials.   Examples of applications are included to support this new approach making Electromagnetic Behaviour of Metallic Wire Structures a comprehensive and ...

  7. Tensile deformation of NiTi wires.

    Science.gov (United States)

    Gall, Ken; Tyber, Jeff; Brice, Valerie; Frick, Carl P; Maier, Hans J; Morgan, Neil

    2005-12-15

    We examine the structure and properties of cold drawn Ti-50.1 at % Ni and Ti-50.9 at % Ni shape memory alloy wires. Wires with both compositions possess a strong fiber texture in the wire drawing direction, a grain size on the order of micrometers, and a high dislocation density. The more Ni rich wires contain fine second phase precipitates, while the wires with lower Ni content are relatively free of precipitates. The wire stress-strain response depends strongly on composition through operant deformation mechanisms, and cannot be explained based solely on measured differences in the transformation temperatures. We provide fundamental connections between the material structure, deformation mechanisms, and resulting stress-strain responses. The results help clarify some inconsistencies and common misconceptions in the literature. Ramifications on materials selection and design for emerging biomedical applications of NiTi shape memory alloys are discussed.

  8. Phosphorus in antique iron music wire.

    Science.gov (United States)

    Goodway, M

    1987-05-22

    Harpsichords and other wire-strung musical instruments were made with longer strings about the beginning of the 17th century. This change required stronger music wire. Although these changes coincided with the introduction of the first mass-produced steel (iron alloyed with carbon), carbon was not found in samples of antique iron harpsichord wire. The wire contained an amount of phosphorus sufficient to have impeded its conversion to steel, and may have been drawn from iron rejected for this purpose. The method used to select pig iron for wire drawing ensured the highest possible phosphorus content at a time when its presence in iron was unsuspected. Phosphorus as an alloying element has had the reputation for making steel brittle when worked cold. Nevertheless, in replicating the antique wire, it was found that lowcarbon iron that contained 0.16 percent phosphorus was easily drawn to appropriate gauges and strengths for restringing antique harpsichords.

  9. First Test of the Performance of CMS Muon Chambers inside the Barrel Yoke

    CERN Document Server

    Jacobi, Emanuel

    2008-01-01

    The Compact Muon Solenoid (CMS) is a multi purpose experimental particle detector at the Large Hardon Collider (LHC). The goal of this experiment is to do fundamental research in particle physics and in particular to prove the validity of the Higgs model. The CMS muon barrel system provides a precise measurement of the position and the momentum of high energy muons. It consists of 250 drift tube chambers, with rectangular drift cells filled with a gas mixture of 85% Ar and 15%CO$_{2}$. Each chamber is equipped with on-chamber readout and trigger electronics. The chambers for the innermost station have been produced at the Physics Institute IIIA at the RWTH University. After installing the chambers at their final position inside the barrel return yoke for the CMS solenoid magnet, cosmic muons have been recorded individually for all chambers and used to evaluate the detector performance, as this is the last chance to easily access the chambers for hardware interventions. These data also provide a good opportuni...

  10. Fabrication and superconducting properties of internal Mg diffusion processed MgB2 wires using MgB4 precursors

    Science.gov (United States)

    Xu, Da; Wang, Dongliang; Yao, Chao; Zhang, Xianping; Ma, Yanwei; Oguro, Hidetoshi; Awaji, Satoshi; Watanabe, Kazuo

    2016-10-01

    Monofilament MgB2/Nb/Monel wires were fabricated using three different MgB4 precursors by an internal Mg diffusion (IMD) process. The wire geometry and heat-treatment conditions were optimized in order to improve the critical current density (J c) of the MgB2 wire. The influences of the quality of MgB4 powders, such as the particle size and MgO impurity, on the microstructure and superconducting properties of the wires were discussed. Although there were small amounts of voids, unreacted MgB4 particles and MgO impurity existed in the superconducting layers, and the transport layer J c of the wire with the MgB4 precursor reached 3.0 × 104 A cm-2 at 4.2 K and 10 T, which was comparable to that of IMD-processed wires fabricated using boron precursors. Both the non-barrier J c and engineering J c of MgB2 wire made using a MgB4 precursor were enhanced due to the improved grain connectivity and the enlarged fill factor.

  11. Wire frame to MOVIE. BYU transfer program

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, D.; Byers, L.D.; Benner, M.S.

    1982-12-01

    At SNLA, the primary computer-aided drafting tool is the Applicon Graphics System (AGS). The data base for mechanical parts on the AGS is a wire frame model. This report summarizes a method of adding surface information to the wire frame and passing this information up stream to MOVIE.BYU which is on a VAX computer and is used to produce shaded graphics pictures of the AGS wire frame model on a RAMTEK 9400 display terminal.

  12. Subchannel Analysis of Wire Wrapped SCWR Assembly

    OpenAIRE

    Jianqiang Shan; Henan Wang; Wei Liu; Linxing Song; Xuanxiang Chen; Yang Jiang

    2014-01-01

    Application of wire wrap spacers in SCWR can reduce pressure drop and obtain better mixing capability. As a consequence, the required coolant pumping power is decreased and the coolant temperature profile inside the fuel bundle is flattened which will obviously decrease the peak cladding temperature. The distributed resistance model for wire wrap was developed and implemented in ATHAS subchannel analysis code. The HPLWR wire wrapped assembly was analyzed. The results show that: (1) the assemb...

  13. Development of Intercalated Wire and Cable.

    Science.gov (United States)

    1984-02-01

    size because of longitudinal splitting. Attempts have been made to 2 substitute wire drawing for the swaging (7) but these have been unsuccessful. It...appears that the radial pressure of the swaging may be an essential ingredient to the process and that the longitudinal tension of wire drawing causes...conductivity. It is possible that the high pressures encountered in swaging as opposed to wire drawing , for instance, are a significant factor. High

  14. Nondestructive Evaluation of Aircraft and Spacecraft Wiring

    Science.gov (United States)

    White, John E.; Tucholski, Edward J.; Green, Robert E., Jr.

    2004-01-01

    Spacecraft, and especially aircraft, often fry well past their original design lives and, therefore, the need to develop nondestructive evaluation procedures for inspection of vital structures in these craft is extremely important. One of the more recent problems is the degradation of wiring and wiring insulation. The present paper describes several nondestructive characterization methods which afford the possibility to detect wiring and insulation degradation in-situ prior to major problems with the safety of aircraft and spacecraft.

  15. IEE wiring regulations explained and illustrated

    CERN Document Server

    Scaddan, Brian

    2013-01-01

    The IEE Wiring Regulations Explained and Illustrated, Second Edition discusses the recommendations of the IEE Regulations for the Electrical Equipment of Buildings for the safe selection or erection of wiring installations. The book emphasizes earthing, bonding, protection, and circuit design of electrical wirings. The text reviews the fundamental requirements for safety, earthing systems, the earth fault loop impedance, and supplementary bonding. The book also describes the different types of protection, such as protection against mechanical damage, overcurrent, under voltage (which prevents

  16. Fracture strength of different soldered and welded orthodontic joining configurations with and without filling material

    Directory of Open Access Journals (Sweden)

    Jens Johannes Bock

    2008-10-01

    Full Text Available The aim of this study was to compare the mechanical strength of different joints made by conventional brazing, TIG and laser welding with and without filling material. Five standardized joining configurations of orthodontic wire in spring hard quality were used: round, cross, 3 mm length, 9 mm length and 7 mm to orthodontic band. The joints were made by five different methods: brazing, tungsten inert gas (TIG and laser welding with and without filling material. For the original orthodontic wire and for each kind of joint configuration or connecting method 10 specimens were carefully produced, totalizing 240. The fracture strengths were measured with a universal testing machine (Zwick 005. Data were analyzed by ANOVA (p=0.05 and Bonferroni post hoc test (p=0.05. In all cases, brazing joints were ruptured on a low level of fracture strength (186-407 N. Significant differences between brazing and TIG or laser welding (p<0.05, Bonferroni post hoc test were found in each joint configuration. The highest fracture strength means were observed for laser welding with filling material and 3 mm joint length (998 N. Using filling materials, there was a clear tendency to higher mean values of fracture strength in TIG and laser welding. However, statistically significant differences were found only in the 9-mm long joints (p<0.05, Bonferroni post hoc test. In conclusion, the fracture strength of welded joints was positively influenced by the additional use of filling material. TIG welding was comparable to laser welding except for the impossibility of joining orthodontic wire with orthodontic band.

  17. Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL)

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) provides a variety of research, design engineering and prototype fabrication services...

  18. Uniform wire segmentation algorithm of distributed interconnects

    Institute of Scientific and Technical Information of China (English)

    Yin Guoli; Lin Zhenghui

    2007-01-01

    A uniform wire segmentation algorithm for performance optimization of distributed RLC interconnects was proposed in this paper. The optimal wire length for identical segments and buffer size for buffer insertion are obtained through computation and derivation, based on a 2-pole approximation model of distributed RLC interconnect. For typical inductance value and long wires under 180nm technology, experiments show that the uniform wire segmentation technique proposed in the paper can reduce delay by about 27% ~ 56% , while requires 34%~69% less total buffer usage and thus 29% to 58% less power consumption. It is suitable for long RLC interconnect performance optimization.

  19. submitter Dynamical Models of a Wire Scanner

    CERN Document Server

    Barjau, Ana; Dehning, Bernd

    2016-01-01

    The accuracy of the beam profile measurements achievable by the current wire scanners at CERN is limited by the vibrations of their mechanical parts. In particular, the vibrations of the carbon wire represent the major source of wire position uncertainty which limits the beam profile measurement accuracy. In the coming years, due to the Large Hadron Collider (LHC) luminosity upgrade, a wire traveling speed up to 20 $m s^{−1}$ and a position measurement accuracy of the order of 1 μm will be required. A new wire scanner design based on the understanding of the wire vibration origin is therefore needed. We present the models developed to understand the main causes of the wire vibrations observed in an existing wire scanner. The development and tuning of those models are based on measurements and tests performed on that CERN proton synchrotron (PS) scanner. The final model for the (wire + fork) system has six degrees-of-freedom (DOF). The wire equations contain three different excitation terms: inertia...

  20. Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL)

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose:The Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) provides a variety of research, design engineering and prototype fabrication services...

  1. Gold nanoparticle wire and integrated wire array for electronic detection of chemical and biological molecules

    Directory of Open Access Journals (Sweden)

    J. J. Diao

    2011-03-01

    Full Text Available Nanoparticle wire and integrated nanoparticle wire array have been prepared through a green technique: discontinuous vertical evaporation-driven colloidal deposition. The conducting gold nanoparticle wire made by this technique shows ability for the sensitive electronic detection of chemical and biological molecules due to its high surface to volume ratio. Furthermore, we also demonstrate a potential usage of integrated gold nanoparticle wire array for the localized detection.

  2. FE modeling of Cu wire bond process and reliability

    NARCIS (Netherlands)

    Yuan, C.A.; Weltevreden, E.R.; Akker, P. van den; Kregting, R.; Vreugd, J. de; Zhang, G.Q.

    2011-01-01

    Copper based wire bonding technology is widely accepted by electronic packaging industry due to the world-wide cost reduction actions (compared to gold wire bond). However, the mechanical characterization of copper wire differs from the gold wire; hence the new wire bond process setting and new bond

  3. FE modeling of Cu wire bond process and reliability

    NARCIS (Netherlands)

    Yuan, C.A.; Weltevreden, E.R.; Akker, P. van den; Kregting, R.; Vreugd, J. de; Zhang, G.Q.

    2011-01-01

    Copper based wire bonding technology is widely accepted by electronic packaging industry due to the world-wide cost reduction actions (compared to gold wire bond). However, the mechanical characterization of copper wire differs from the gold wire; hence the new wire bond process setting and new bond

  4. Wired

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    迄今为止,已有45000个项目借助在线捐赠成功完成众筹,金额总计达5亿美元以上。其中绝大部分(据估计为80%)来自Kickstarter网站,这家网站如今几乎成了“众筹”这一术语的代名词。

  5. THERMO-MECHANICALLY PROCESSED ROLLED WIRE FOR HIGH-STRENGTH ON-BOARD WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2011-01-01

    Full Text Available It is shown that at twisting of wire of diameter 1,83 mm, produced by direct wire drawing of thermomechanically processed rolled wire of diameter 5,5 mm of steel 90, metal stratification is completely eliminated at decrease of carbon, manganese and an additional alloying of chrome.

  6. Finite element analysis on the wire breaking rule of 1×7IWS steel wire rope

    Directory of Open Access Journals (Sweden)

    Wenzheng Du

    2017-01-01

    Full Text Available Taking the wire rope of 1×7+IWS structure as the research object, the influences of the number of broken wires on the stress distribution under the same axial load were simulated and analysed, and it also explored the rule of wire breaking of steel wire ropes. Based on the SolidWorks software, the three-dimensional model of the wire rope was established. Importing the model into the ABAQUS, the finite element model of the steel wire rope was established. Firstly 5000 N axial tension was placed on the rope, the stress distribution was simulated and analysed, and the steel wire with the largest stress distribution was found out. Then one steel wire was truncated with the load unchanged, and the finite element simulation was carried out again, and repeated the steps several times. The results show that, with the increase of the number of broken wires, the Von-Mises stress of the wire rope increases sharply, and the stress distribution is concentrated on the rest of the unbroken wires, which brings great challenges to the safety of the wire rope.

  7. Compact Frontend-Electronics and Bidirectional 3.3 Gbps Optical Datalink for Fast Proportional Chamber Readout

    CERN Document Server

    Lüders, S

    2001-01-01

    The 9600 channels of the multi-wire proportional chamber of the H1 experiment at HERA have to be read out within 96 ns and made available to the trigger system. The tight spatial conditions at the rear end flange require a compact bidirectional readout electronics with minimal power consumption and dead material. A solution using 40 identical optical link modules, each transferring the trigger information with a physical rate of 4 x 832 Mbps via optical fibers, has been developed and commisioned. The analog pulses from the chamber can be monitored and the synchronization to the global HERA clock signal is ensured.

  8. Understanding the Relationship Between Filling Pattern and Part Quality in Die Casting

    Energy Technology Data Exchange (ETDEWEB)

    Jerald Brevick; R. Allen Miller

    2004-03-15

    The overall objective of this research project was to investigate phenomena involved in the filling of die cavities with molten alloy in the cold chamber die-casting process. It has long been recognized that the filling pattern of molten metal entering a die cavity influences the quality of die-cast parts. Filling pattern may be described as the progression of molten metal filling the die cavity geometry as a function of time. The location, size and geometric configuration of points of metal entry (gates), as well as the geometry of the casting cavity itself, have great influence on filling patterns. Knowledge of the anticipated filling patterns in die-castings is important for designers. Locating gates to avoid undesirable flow patterns that may entrap air in the casting is critical to casting quality - as locating vents to allow air to escape from the cavity (last places to fill). Casting quality attributes that are commonly flow related are non-fills, poor surface finish, internal porosity due to trapped air, cold shuts, cold laps, flow lines, casting skin delamination (flaking), and blistering during thermal treatment.

  9. Loss of ions in cavity ionization chambers

    Energy Technology Data Exchange (ETDEWEB)

    Takata, N. [Ionizing Radiation Section, NMIJ/AIST, Tsukuba 305-8568 (Japan)]. E-mail: n.takata@aist.go.jp; Tran, N.T. [Institute for Nuclear Science and Technique, VAEC, Hanoi (Viet Nam); Kim, E. [Radiation Safety Section, NIRS, Inageku, Chiba-city 263-8555 (Japan); Marsoem, P. [P3KRBiN-BATAN, JL Cinere-Pasar Jum' at, Jakarta 12070 (Indonesia); Kurosawa, T. [Ionizing Radiation Section, NMIJ/AIST, Tsukuba 305-8568 (Japan); Koyama, Y. [Ionizing Radiation Section, NMIJ/AIST, Tsukuba 305-8568 (Japan)

    2005-12-01

    Ion losses due to initial recombination, volume recombination, and back diffusion were each determined by measurements and calculations for different size cylindrical ionization chambers and spherical ionization chambers. By measuring signal currents from these ionization chambers irradiated with {sup 60}Co gamma rays, two groups of ion losses were obtained. (Group 1) Ion loss due to initial recombination and diffusion, which changes proportionally to the inverse of the voltage applied to the ionization chambers; (and group 2) ion loss due to volume recombination, which changes proportionally to the inverse of the square of the applied voltage. The diffusion loss was obtained separately by computing electric field distributions in the ionization chambers. It was found that diffusion loss is larger than initial recombination loss for the cylindrical ionization chambers and vise versa for the spherical ionization chambers.

  10. Pupillary block glaucoma following implantation of a posterior chamber pseudophakos in the anterior chamber.

    Directory of Open Access Journals (Sweden)

    Mandal Anil

    2002-01-01

    Full Text Available Pupillary block glaucoma is a common complication of cataract surgery, especially following anterior chamber intraocular lens implantation. We report a case of pupillary block glaucoma with a posterior chamber IOL that was implanted in the anterior chamber following a complicated extracapsular cataract extraction. The case was successfully managed by explantation of the posterior chamber lens, anterior vitrectomy, peripheral iridectomy and secondary anterior chamber intraocular lens implantation. The intraocular pressure was controlled with a single topical antiglaucoma medication.

  11. Basic Aerodynamics of Combustion Chambers,

    Science.gov (United States)

    1981-05-20

    8217, tie imnrulse foree eyuilibr-um c’ the bomd’~ leye - is 173 pv-:irJ p~76vJbK 2sO) IL !-. = Zn pT -- a , bV T. z -,,r y.re C era 3oia * ~~I" onc art-=e...heat by combustion all have very large influences on the capabilities of a combustion chamber. A yellow- colored flame represents diffusion combustion in...the wakes of fuel droplets. Blue- colored flames represent gaseous combustion of evaporated vapors which have already left the fuel droplets. The

  12. AMS Measurement of 36Cl With a Gas-filled Time of Flight Detector

    Institute of Scientific and Technical Information of China (English)

    GUANYong-jing; HEMing; RUANXiang-dong; WANGHui-juan; LIGuo-qiang; WUShao-yong; WUWei-ming; JIANGShan

    2003-01-01

    In order to determine 36Cl and 36S with high sensitivity by AMS, the present study has been done.Difference of time flight in the gas dependences to total energy, gas pressure in the chamber, and the flight length for isobars. The time resolution (FWHM) of the detector system is 800 ps without gas-filled when the ion energy is 72 MeV. Time straggling is growth with the increase of gas pressure in the chamber.Time straggling caused by the gas pressure is shown in Fig.1.

  13. Tuning a Tetrahertz Wire Laser

    Science.gov (United States)

    Qin, Qi; Williams, Benjamin S.; Kumar, Sushil; Reno, John L.; Hu, Qing

    2009-01-01

    Tunable terahertz lasers are desirable in applications in sensing and spectroscopy because many biochemical species have strong spectral fingerprints at terahertz frequencies. Conventionally, the frequency of a laser is tuned in a similar manner to a stringed musical instrument, in which pitch is varied by changing the length of the string (the longitudinal component of the wave vector) and/ or its tension (the refractive index). However, such methods are difficult to implement in terahertz semiconductor lasers because of their poor outcoupling efficiencies. Here, we demonstrate a novel tuning mechanism based on a unique 'wire laser' device for which the transverse dimension w is much much less than lambda. Placing a movable object close to the wire laser manipulates a large fraction of the waveguided mode propagating outside the cavity, thereby tuning its resonant frequency. Continuous single-mode redshift and blueshift tuning is demonstrated for the same device by using either a dielectric or metallic movable object. In combination, this enables a frequency tuning of approximately equal to 137 GHz (3.6%) from a single laser device at approximately equal to 3.8 THz.

  14. Bird on a (live) wire

    Energy Technology Data Exchange (ETDEWEB)

    Farr, M.

    2003-09-30

    Bird mortality as a result of contact with power lines is discussed. U. S. statistics are cited, according to which 174 million birds annually die as a result of contact with power lines, specifically when birds touch two phases of current at the same time. Raptors are particularly vulnerable to power-line electrocution due to their habit of perching on the highest vantage point available as they survey the ground for prey. Hydro lines located in agricultural areas, with bodies of water on one side and fields on the other, also obstruct flight of waterfowl as dusk and dawn when visibility is low. Various solutions designed to minimize the danger to birds are discussed. Among these are: changing the configuration of wires and cross arms to make them more visible to birds in flight and less tempting as perches, and adding simple wire markers such as flags, balloons, and coloured luminescent clips that flap and twirl in the wind. There is no evidence of any coordinated effort to deal with this problem in Ontario. However, a report is being prepared for submission to Environment Canada outlining risks to birds associated with the growing number of wind turbine power generators (negligible compared with power lines and communications towers), and offering suggestions on remedial measures. The Fatal Light Awareness Program (FLAP) also plans to lobby the Canadian Wildlife Service to discuss the possibility of coordinating efforts to monitor, educate about and ultimately reduce this form of bird mortality.

  15. Construction of a fast ionization chamber for high-rate particle identification

    Energy Technology Data Exchange (ETDEWEB)

    Chae, K.Y., E-mail: kchae@skku.edu [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Ahn, S. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Bardayan, D.W. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Chipps, K.A. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Department of Physics, Colorado School of Mines, Golden, CO 80401 (United States); Manning, B. [Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854 (United States); Pain, S.D. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Peters, W.A. [Oak Ridge Associated Universities, Oak Ridge, TN 37831 (United States); Schmitt, K.T. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Smith, M.S. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Strauss, S.Y. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854 (United States)

    2014-07-01

    A new gas-filled ionization chamber for high count rate particle identification has been constructed and commissioned at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). To enhance the response time of the ionization chamber, a design utilizing a tilted entrance window and tilted electrodes was adopted, which is modified from an original design by Kimura et al. [1]. A maximum counting rate of ∼700,000 particles per second has been achieved. The detector has been used for several radioactive beam measurements performed at the HRIBF.

  16. Construction of a fast ionization chamber for high-rate particle identification

    Science.gov (United States)

    Chae, K. Y.; Ahn, S.; Bardayan, D. W.; Chipps, K. A.; Manning, B.; Pain, S. D.; Peters, W. A.; Schmitt, K. T.; Smith, M. S.; Strauss, S. Y.

    2014-07-01

    A new gas-filled ionization chamber for high count rate particle identification has been constructed and commissioned at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). To enhance the response time of the ionization chamber, a design utilizing a tilted entrance window and tilted electrodes was adopted, which is modified from an original design by Kimura et al. [1]. A maximum counting rate of ~700,000 particles per second has been achieved. The detector has been used for several radioactive beam measurements performed at the HRIBF.

  17. Design features and test results of the CMS endcap muon chambers

    CERN Document Server

    Acosta, D; Arisaka, K; Blomqvist, J M; Breedon, R; Bondar, N; Bonushkin, Yu; Borissov, E; Bujak, A; Bylsma, B; Chester, N S; Chrisman, D; Clare, R; Cline, D; Cousins, R D

    2002-01-01

    Presented are the main design features and performance results of the Cathode Strip Chambers for the CMS Endcap Muon system. Although the strips are unusually wide (up to 16 mm) for the cathode-to-anode wire distance of 5 mm, the six-plane structure of these chambers yields a spatial resolution of about 80 mum, essentially uniform and independent of the strip width. In addition, the net spatial resolution of about one-tenth of the strip width at the hardware trigger level (300 ns) is obtained using a simple network of comparators. Time resolution achieved at the trigger level is similar to 4 ns (rms) that allows unambiguous tagging of bunch crossings which occur every 25 ns. Aging test results, including those obtained with a recirculating gas system, are discussed; only minor aging affects were observed. The aging studies were performed with large- scale chambers; 700 m of wire were irradiated for a dose up to 0.4 C /cm of the total accumulated charge.

  18. Combustion of Shock-Dispersed Fuels in a Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Neuwald, P; Reichenbach, H; Kuhl, A L

    2003-04-23

    In previous studies we have investigated after-burning effects of a fuel-rich explosive (TNT). In that case the detonation only releases about 30 % of the available energy, but generates a hot cloud of fuel that can burn in the ambient air, thus evoking an additional energy release that is distributed in space and time. The current series of small-scale experiments can be looked upon as a natural generalization of this mechanism: a booster charge disperses a (non-explosive) fuel, provides mixing with air and - by means of the hot detonation products - energy to ignite the fuel. The current version of our miniature Shock-Dispersed-Fuel (SDF) charges consists of a spherical booster charge of 0.5 g PETN, embedded in a paper cylinder of approximately 2.2 cm3, which is filled with powdered fuel compositions. The main compositions studied up to now contain aluminum powder, hydrocarbon powders like polyethylene or sucrose and/or carbon particles. These charges were studied in three different chambers of 4-1, 6.6-1 and 40.5-1 volume. In general, the booster charge was sufficient to initiate burning of the fuel. This modifies the pressure signatures measured with a number of wall gages and increases the quasi-static overpressure level obtained in the chambers. On the one hand the time-scale and the yield of the pressure rise depend on the fuel and its characteristics. On the other hand they also depend on the flow dynamics in the chamber, which is dominated by shock reverberations, and thus on the chamber geometry and volume. The paper gives a survey of the experimental results and discusses the possible influences of some basic parameters.

  19. Thermal Performance Evaluation of Walls with Gas Filled Panel Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Desjarlais, Andre Omer [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-11-01

    Gas filled insulation panels (GFP) are very light weight and compact (when uninflated) advanced insulation products. GFPs consist of multiple layers of thin, low emittance (low-e) metalized aluminum. When expanded, the internal, low-e aluminum layers form a honeycomb structure. These baffled polymer chambers are enveloped by a sealed barrier and filled with either air or a low-conductivity gas. The sealed exterior aluminum foil barrier films provide thermal resistance, flammability protection, and properties to contain air or a low conductivity inert gas. This product was initially developed with a grant from the U.S. Department of Energy. The unexpanded product is nearly flat for easy storage and transport. Therefore, transportation volume and weight of the GFP to fill unit volume of wall cavity is much smaller compared to that of other conventional insulation products. This feature makes this product appealing to use at Army Contingency Basing, when transportation cost is significant compared to the cost of materials. The objective of this study is to evaluate thermal performance of walls, similar to those used at typical Barracks Hut (B-Hut) hard shelters, when GFPs are used in the wall cavities. Oak Ridge National Laboratory (ORNL) tested performance of the wall in the rotatable guarded hotbox (RGHB) according to the ASTM C 1363 standard test method.

  20. Thermoprocessing and wire drawing behaviour of ultra high strength steel wires

    OpenAIRE

    Bargujer, S.S.; Singh, Parvinder; Raizada, Vikas

    2016-01-01

    The thermo-processing of piano wire rods is carried out in the lead bath. This experimentation is carried out under industrial conditions. The investigation is done to examine the effect of austenitic time, lead bath time and wire diameter on mechanical properties of lead patented wire. The Taguchi technique is adopted for optimization of thermo-processing of hypereutectoid steel wires. The lead patented wire of diameter 7.00 mm is cold drawn in a sequence of conical converging dies. The best...

  1. REMEDY OF WIRE LAG IN WIRE ELECTRICAL DISCHARGE MACHINING (WEDM

    Directory of Open Access Journals (Sweden)

    S. K. SINHA

    2010-12-01

    Full Text Available WEDM is extensively used these days for generating complex geometries with tight tolerances on difficult-tomachine materials. Therefore, demand for improvement in precision has been ever increasing. The main source of inaccuracy is wire-lag, the cause and effect of which is well-known. Research has been going on to overcome this drawback. So far, the techniques suggested for improvement in accuracy are, in general, based on monitoring the machining process at hardware-level, which is not only tedious but involves extra expenditure also. In the present paper, a software approach for improvement in accuracy is described, which does not require any additional investment on the machine, and still gives very good results.

  2. Investigation of a wire plate micro heat pipe array

    Energy Technology Data Exchange (ETDEWEB)

    Launay, Stephane; Sartre, Valerie; Lallemand, Monique [CETHIL, UMR CNRS 5008, INSA, 20, av. A. Einstein, 69621 Cedex, Villeurbanne (France); Mantelli, Marcia B.H.; Paiva, Kleber Vieira de [Mechanical Engineering Department, Federal University of Santa Catarina UFSC, P.O. Box 476, 88040-900, SC, Florianopolis (Brazil)

    2004-05-01

    In the present work, experimental and theoretical investigations have been conducted on a copper/water wire plate micro heat pipe (MHP). The experimental results show that its effective thermal conductivity is improved by a factor 1.3 as compared to the empty MHP array. A numerical model is used to predict the fluid distribution along the MHP axis, the temperature field and the maximum heat flux corresponding to the MHP capillary limit. The 1D, steady-state hydrodynamic model is based on the conservation equations for the liquid and vapour phases. The wall temperatures are calculated from the thermal resistance network of the wall and the liquid film. A good agreement between the theoretical and experimental data is achieved. The effect of various parameters - contact angle, fluid type, corner angle, fill charge - is theoretically investigated. (authors)

  3. Hot wire needle probe for thermal conductivity detection

    Energy Technology Data Exchange (ETDEWEB)

    Condie, Keith Glenn; Rempe, Joy Lynn; Knudson, Darrell lee; Daw, Joshua Earl; Wilkins, Steven Curtis; Fox, Brandon S.; Heng, Ban

    2015-11-10

    An apparatus comprising a needle probe comprising a sheath, a heating element, a temperature sensor, and electrical insulation that allows thermal conductivity to be measured in extreme environments, such as in high-temperature irradiation testing. The heating element is contained within the sheath and is electrically conductive. In an embodiment, the heating element is a wire capable of being joule heated when an electrical current is applied. The temperature sensor is contained within the sheath, electrically insulated from the heating element and the sheath. The electrical insulation electrically insulates the sheath, heating element and temperature sensor. The electrical insulation fills the sheath having electrical resistance capable of preventing electrical conduction between the sheath, heating element, and temperature sensor. The control system is connected to the heating element and the temperature sensor.

  4. Topological transition in coated wire medium

    CERN Document Server

    Gorlach, Maxim A; Slobozhanyuk, Alexey P; Bogdanov, Andrey A; Belov, Pavel A

    2016-01-01

    We develop a theory of nonlocal homogenization for metamaterial consisting of parallel metallic wires with dielectric coating. It is demonstrated that manipulation of dielectric contrast between wire dielectric shell and host material results in switching of metamaterial dispersion regime from elliptic to the hyperbolic one, i.e. the topological transition takes place. We confirm our theoretical predictions by full-wave numerical simulations.

  5. Kirschner Wire Breakage during Removal Requiring Retrieval

    Directory of Open Access Journals (Sweden)

    Kai Yuen Wong

    2016-01-01

    Full Text Available Kirschner wires (K-wires are widely used for fixation of fractures and dislocations in the hand as they are readily available, reliable, and cost-effective. Complication rates of up to 18% have been reported. However, K-wire breakage during removal is rare. We present one such case illustrating a simple technique for retrieval. A 35-year-old male presented with a distal phalanx fracture of his right middle finger. This open fracture was treated with K-wire fixation. Postoperatively, he developed a pin site infection with associated finger swelling. The K-wire broke during removal with the proximal piece completely retained in his middle phalanx. To minimise risk of osteomyelitis, the K-wire was removed with a novel surgical technique. He had full return of hand function. Intraoperative K-wire breakage has a reported rate of 0.1%. In our case, there was no obvious cause of breakage and the patient denied postoperative trauma. On the other hand, pin site infections are much more common with reported rates of up to 7% in the hand or wrist. K-wire fixation is a simple method for bony stabilisation but can be a demanding procedure with complications often overlooked. It is important to be aware of the potential sequelae.

  6. Flywheel system using wire-wound rotor

    Energy Technology Data Exchange (ETDEWEB)

    Chiao, Edward Young; Bender, Donald Arthur; Means, Andrew E.; Snyder, Philip K.

    2016-06-07

    A flywheel is described having a rotor constructed of wire wound onto a central form. The wire is prestressed, thus mitigating stresses that occur during operation. In another aspect, the flywheel incorporates a low-loss motor using electrically non-conducting permanent magnets.

  7. Microfabricated wire arrays for Z-pinch.

    Energy Technology Data Exchange (ETDEWEB)

    Spahn, Olga Blum; Rowen, Adam M.; Cich, Michael Joseph; Peake, Gregory Merwin; Arrington, Christian L.; Nash, Thomas J.; Klem, John Frederick; Romero, Dustin Heinz

    2008-10-01

    Microfabrication methods have been applied to the fabrication of wire arrays suitable for use in Z. Self-curling GaAs/AlGaAs supports were fabricated as an initial route to make small wire arrays (4mm diameter). A strain relief structure that could be integrated with the wire was designed to allow displacements of the anode/cathode connections in Z. Electroplated gold wire arrays with integrated anode/cathode bus connections were found to be sufficiently robust to allow direct handling. Platinum and copper plating processes were also investigated. A process to fabricate wire arrays on any substrate with wire thickness up to 35 microns was developed. Methods to handle and mount these arrays were developed. Fabrication of wire arrays of 20mm diameter was demonstrated, and the path to 40mm array fabrication is clear. With some final investment to show array mounting into Z hardware, the entire process to produce a microfabricated wire array will have been demonstrated.

  8. WIRED magazine announces rave awards nominees

    CERN Multimedia

    2002-01-01

    WIRED Magazine has anounced the nominees for its fourth annual WIRED Rave Awards, celebrating innovation and the individuals transforming commerce and culture. Jeffrey Hangst of the University of Aarhus has been nominated in the science category, for his work on the ATHENA Experiment, CERN (1/2 page).

  9. Hot-wire anemometer for spirography.

    Science.gov (United States)

    Plakk, P; Liik, P; Kingisepp, P H

    1998-01-01

    The use of a constant temperature hot-wire anemometer flow sensor for spirography is reported. The construction, operating principles and calibration procedure of the apparatus are described, and temperature compensation method is discussed. Frequency response is studied. It is shown that this hot-wire flow transducer satisfies common demands with respect to accuracy, response time and temperature variations.

  10. Transcolonic Migration of Retained Epicardial Pacing Wires

    Directory of Open Access Journals (Sweden)

    Sara Gonzales

    2015-01-01

    Full Text Available Temporary epicardial pacing wires are associated with rare complications. Most of these occur in the chest. Even rarer are complications that occur within the abdomen. We report a case of migrating epicardial pacing wires entering the abdomen and penetrating the transverse colon found incidentally on colonoscopy in an asymptomatic patient.

  11. A Wire Grid Paraboloid for Large Low Frequency Telescopes

    Science.gov (United States)

    Kuiper, Tom

    2017-05-01

    Planetary magnetic fields are usually studied remotely through their electron cyclotron maser (ECM) emission from electrons trapped in their magnetic fields. Jupiter has been well studied since the 1960's because its strong magnetic field allows emissions up to about 40 MHz to be observed. The emission from Earth and other outer planets is mostly below 1 MHz and can only be observed from space. It is reasonable to assume that most exoplanets with ECM must be observed at low frequencies from space. Even optimistic assumptions about the strength of such emission leads one to conclude that very large filled aperture telescopes, with a diameters of a kilometer or more, will be needed.This paper reports on a study of a copper wire reflector with a diameter of 1 km operating between 100 kHz and 3.75 MHz. It would require 200 kg of 0.5 mm diameter copper wire (AWG 24)) to be lifted to and deployed in space. For aluminum, the mass would be about 100 kg. By optimizing the wire spacing the mass can be reduced to 80% of a simple radial-azimuthal arrangement. A relatively flat reflector (0.6 ≤ f/D ≤ 1.0) needs to be anchored at about 5 points from center to ring along 24 radii. Station-keeping CubeSats could serve as anchors. A total of about 100-120 anchors would be needed for an f/D = 1 reflector, adding 200-300 kg. to the mass of the reflector. It would be possible to carry several such reflectors into space in a single payload.The Deep Space Network is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract to the National Aeronautics and Space Administration.

  12. Transferring calibration coefficients from ionisation chambers used for diagnostic radiology to transmission chambers.

    Science.gov (United States)

    Yoshizumi, Maíra T; Caldas, Linda V E

    2012-07-01

    In this work, the response of a double volume transmission ionisation chamber, developed at the Instituto de Pesquisas Energéticas e Nucleares, was compared to that of a commercial transmission chamber. Both ionisation chambers were tested in different X-ray beam qualities using secondary standard ionisation chambers as reference dosimeters. These standard ionisation chambers were a parallel-plate and a cylindrical ionisation chambers, used for diagnostic radiology and mammography beam qualities, respectively. The response of both transmission chambers was compared to that of the secondary standard chambers to obtain coefficients of equivalence. These coefficients allow the transmission chambers to be used as reference equipment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Wire and Cable Cold Bending Test

    Science.gov (United States)

    Colozza, Anthony

    2010-01-01

    One of the factors in assessing the applicability of wire or cable on the lunar surface is its flexibility under extreme cold conditions. Existing wire specifications did not address their mechanical behavior under cold, cryogenic temperature conditions. Therefore tests were performed to provide this information. To assess this characteristic 35 different insulated wire and cable pieces were cold soaked in liquid nitrogen. The segments were then subjected to bending and the force was recorded. Any failure of the insulation or jacketing was also documented for each sample tested. The bending force tests were performed at room temperature to provide a comparison to the change in force needed to bend the samples due to the low temperature conditions. The results from the bending tests were plotted and showed how various types of insulated wire and cable responded to bending under cold conditions. These results were then used to estimate the torque needed to unroll the wire under these low temperature conditions.

  14. Development and Manufacture of Bi-2223 Wires

    Science.gov (United States)

    Kobayashi, Shin-Ichi

    This chapter reviews Ag-sheathed (Bi, Pb)2Sr2Ca2Cu3Ox (Bi-2223) wire made by the powder-in-tube technique (PIT). The currently leading high-temperature superconductors (HTS) wire technology for practical use is Bi-2223 wire, made by the controlled over-pressure (CT-OP) sintering process. The CT-OP process uses pressures up to 30MPa during heat treatment. The technique densifies the Bi-2223 filaments and enhances the uniformity of the electrical and mechanical performance in the Bi-2223 wire. Today, Bi-2223 wires are used in most HTS applications, such as power cables, many kinds of magnets, and motors for ship propulsion and electric vehicles.

  15. CATS, a low pressure multiwire proportional chamber for secondary beam tracking at GANIL

    CERN Document Server

    Ottini-Hustache, S; Auger, F; Musumarra, A; Alamanos, N; Cahan, B; Gillibert, A; Lagoyannis, A; Maillard, O; Pollacco, E; Sida, J L; Riallot, M

    1999-01-01

    A beam detector system, CATS (Chambre A Trajectoires de Saclay), was designed to provide event-by-event particle tracking in experiments with radioactive beams at GANIL. It consists of two low pressure multiwire proportional chambers with one plane of anode wires placed between two cathode planes (active area: 70x70 mm sup 2), respectively segmented into 28 vertical or horizontal strips (2.54 mm wide). The anode wires deliver a time signal allowing a time of flight measurement with an accuracy between 440 ps and 1.2 ns, depending on the energy loss of incident particles in the detector. The cathode strips are individually read out and the position of incoming particles is reconstructed using a charge centroid finding algorithm. A spatial resolution of 400 mu m (700 mu m) was achieved during in beam experiment, with a counting rate of 1.5x10 sup 5 (10 sup 6) particles per second. (author)

  16. Anodically bonded submicron microfluidic chambers.

    Science.gov (United States)

    Dimov, S; Bennett, R G; Córcoles, A; Levitin, L V; Ilic, B; Verbridge, S S; Saunders, J; Casey, A; Parpia, J M

    2010-01-01

    We demonstrate the use of anodic bonding to fabricate cells with characteristic size as large as 7 x 10 mm(2), with height of approximately 640 nm, and without any internal support structure. The cells were fabricated from Hoya SD-2 glass and silicon wafers, each with 3 mm thickness to maintain dimensional stability under internal pressure. Bonding was carried out at 350 degrees C and 450 V with an electrode structure that excluded the electric field from the open region. We detail fabrication and characterization steps and also discuss the design of the fill line for access to the cavity.

  17. Anodically bonded submicron microfluidic chambers

    Science.gov (United States)

    Dimov, S.; Bennett, R. G.; Córcoles, A.; Levitin, L. V.; Ilic, B.; Verbridge, S. S.; Saunders, J.; Casey, A.; Parpia, J. M.

    2010-01-01

    We demonstrate the use of anodic bonding to fabricate cells with characteristic size as large as 7×10 mm2, with height of ≈640 nm, and without any internal support structure. The cells were fabricated from Hoya SD-2 glass and silicon wafers, each with 3 mm thickness to maintain dimensional stability under internal pressure. Bonding was carried out at 350 °C and 450 V with an electrode structure that excluded the electric field from the open region. We detail fabrication and characterization steps and also discuss the design of the fill line for access to the cavity.

  18. Ion distributions in plane and cylindrical chambers.

    Science.gov (United States)

    Rosen, R; George, E P

    1975-11-01

    The ion chamber equations of Thomson include both ion recombination and space-charge terms. Neglecting the space-charge term, an exact solution is obtained for the ion densities across a plane ionization chamber. The method is extended to the cylindrical chamber, and examples are given of the expected ion distributions in both geometries. Current-voltage relationships are derived for both chambers and compared with those of other workers. If the space-charge term is retained, the ion chamber equations for both geometries are not soluble in closed form. The cylindrical chamber is considered and a computer solution is obtained for the ion distributions and current. Comparison with the nonspace-charge solution shows that while there is only a small difference in the current-voltage relationship, a significant difference can occur in the ion concentrations.

  19. A mathematical model of aerosol holding chambers

    DEFF Research Database (Denmark)

    Zak, M; Madsen, J; Berg, E

    1999-01-01

    A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol...... in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during "breathing" was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London......, Ontario, Canada), NebuChamber (Astra, Södirtälje, Sweden) and Nebuhaler (Astra) adapted for babies. The dose of fluticasone proportionate delivered by the Babyhaler (Glaxco Wellcome, Oxbridge, Middlesex, UK) was 80% of that predicted, probably because of incomplete priming of this spacer. Of the above...

  20. Tests of anechoic chamber for aeroacoustics investigations

    Science.gov (United States)

    Palchikovskiy, V. V.; Bersenev, Yu. V.; Makashov, S. Yu.; Belyaev, I. V.; Korin, I. A.; Sorokin, E. V.; Khramtsov, I. V.; Kustov, O. Yu.

    2016-10-01

    The paper presents the results of qualification tests in the new anechoic chamber of Perm National Research Polytechnic University (PNRPU) built in 2014-2015 and evaluation of the chamber quality in aeroacoustic experiments. It describes design features of the chamber and its sound-absorption lining. The qualification tests were carried out with tonal and broadband noise sources in the frequency range 100 Hz - 20 kHz for two different cases of the source arrangement. In every case, measurements were performed in three directions by traverse microphones. Qualification tests have determined that in the chamber there is a free acoustic field within radius of 2 m for tonal noise and 3 m for broadband noise. There was also evaluated acoustic quality of the chamber by measurements of the jet noise and vortex ring noise. The results of the experiments demonstrate that PNRPU anechoic chamber allows the aeroacoustic measurements to be performed to obtain quantitative results.

  1. Phonon spectra in quantum wires

    Directory of Open Access Journals (Sweden)

    Ilić Dušan

    2007-01-01

    Full Text Available Green's function method, adjusted to bound crystalline structures, was applied to obtain the phonon dispersion law in quantum wires. The condition of the existence of small mechanical atom movements defining phonon spectra can be found by solving the secular equation. This problem was presented graphically for different boundary parameters. The presence of boundaries, as well as the change of boundary parameters, leads to the appearance of new properties of the layered structure. The most important feature is that, beside the allowed energy zones (which are continuous as in the bulk structure, zones of forbidden states appear. Different values of the boundary parameters lead to the appearance of lower and upper energy gaps, or dispersion branches spreading out of the bulk energy zone. The spectra of phonons in corresponding unbound structures were correlated to those in bound structures.

  2. Front-end electronics and data acquisition system for a multi-wire 3D gas tracker

    CERN Document Server

    Lojek, K; Bodek, K; Perkowski, M; Severijns, N

    2015-01-01

    This paper presents the design and implementation of the front-end electronics and the data acquisition (DAQ) system for readout of multi-wire drift chambers (MWDC). Apart of the conventional drift time measurement the system delivers the hit position along the wire utilizing the charge division technique. The system consists of preamplifiers, and analog and digital boards sending data to a back-end computer via an Ethernet interface. The data logging software formats the received data and enables an easy access to the data analysis software. The use of specially designed preamplifiers and peak detectors allows the charge-division readout of the low resistance signal wire. The implication of the charge-division circuitry onto the drift time measurement was studied and the overall performance of the electronic system was evaluated in dedicated off-line tests.

  3. Study of soft X-ray emission during wire array implosion under plasma focus conditions at the PF-3 facility

    Energy Technology Data Exchange (ETDEWEB)

    Dan’ko, S. A. [National Research Centre Kurchatov Institute (Russian Federation); Mitrofanov, K. N., E-mail: mitrofan@triniti.ru [Troitsk Institute for Innovation and Fusion Research (Russian Federation); Krauz, V. I.; Myalton, V. V.; Zhuzhunashvili, A. I.; Vinogradov, V. P.; Kharrasov, A. M.; Anan’ev, S. S.; Vinogradova, Yu. V.; Kalinin, Yu. G. [National Research Centre Kurchatov Institute (Russian Federation)

    2015-11-15

    Results of measurements of soft X-ray emission with photon energies of <1 keV under conditions of a plasma focus (PF) experiment are presented. The experiments were carried out at the world’s largest PF device—the PF-3 Filippov-type facility (I ⩽ 3 MA, T/4 ≈ 15–20 µs, W{sub 0} ⩽ 3 MJ). X-ray emission from both a discharge in pure neon and with a tungsten wire array placed on the axis of the discharge chamber was detected. The wire array imploded under the action of the electric current intercepted from the plasma current sheath of the PF discharge in neon. The measured soft X-ray powers from a conventional PF discharge in gas and a PF discharge in the presence of a wire array were compared for the first time.

  4. The ARGUS microvertex drift chamber

    Science.gov (United States)

    Michel, E.; Schmidt-Parzefall, W.; Appuhn, R. D.; Buchmüller, J.; Kolanoski, H.; Kreimeier, B.; Lange, A.; Siegmund, T.; Walther, A.; Edwards, K. W.; Fernholz, R. C.; Kapitza, H.; MacFarlane, D. B.; O'Neill, M.; Parsons, J. A.; Prentice, J. D.; Seidel, S. C.; Tsipolitis, G.; Ball, S.; Babaev, A.; Danilov, M.; Tichomirov, I.

    1989-11-01

    The ARGUS collaboration is currently building a new microvertex drift chamber (μVDC) as an upgrade of their detector. The μVDC is optimized for B-meson physics at DORIS energies. Important design features are minimal multiple scattering for low-momentum particles and three-dimensional reconstruction of decay vertices with equal resolutions in r- φ and r- z. Vertex resolutions of 15-25 μm are expected. Prototypes of the μVDC have been tested with different gas mixtures at various pressures. Spatial resolutions as small as 20 μm were obtained using CO 2/propane at 4 bar and DME at 1 bar. New readout electronics have been developed for the μVDC aiming at low thresholds for the TDC measurements. Employing a novel idea for noise and cross-talk suppression, which is based on a discrimination against short pulses, very low threshold settings are possible.

  5. Drift chamber tracking with neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey, C.S.; Denby, B.; Haggerty, H.

    1992-10-01

    We discuss drift chamber tracking with a commercial log VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed.

  6. Vacuum Chamber for the Booster Bending Magnets

    CERN Multimedia

    1974-01-01

    To minimize eddy currents, induced by the rising magnetic field, the chamber was made from thin stainless steel of high specific electric resistance. For mechanical stength, it was corrugated in a hydro-forming process. The chamber is curved, to follow the beam's orbital path. Under vacuum, the chamber tends to staighten, the ceramic spacer along half of its length keeps it in place (see also 7402458).

  7. Bubble chamber: Omega production and decay

    CERN Multimedia

    1973-01-01

    This image is taken from one of CERN's bubble chambers and shows the decay of a positive kaon in flight. The decay products of this kaon can be seen spiraling in the magnetic field of the chamber. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that has been heated to boiling point.

  8. Free-Flow Open-Chamber Electrophoresis

    Science.gov (United States)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Free-flow open-chamber electrophoresis variant of free-flow electrophoresis performed in chamber with open ends and in which velocity of electro-osmotic flow adjusted equal to and opposite mean electrophoretic velocity of sample. Particles having electrophoretic mobilities greater than mean mobility of sample particles move toward cathode, those with mobilities less move toward anode. Technique applied to separation of components of mixtures of biologically important substances. Sensitivity enhanced by use of tapered chamber.

  9. Filling of carbon nanotubes and nanofibres

    Directory of Open Access Journals (Sweden)

    Reece D. Gately

    2015-02-01

    Full Text Available The reliable production of carbon nanotubes and nanofibres is a relatively new development, and due to their unique structure, there has been much interest in filling their hollow interiors. In this review, we provide an overview of the most common approaches for filling these carbon nanostructures. We highlight that filled carbon nanostructures are an emerging material for biomedical applications.

  10. Engineering verification of the biomass production chamber

    Science.gov (United States)

    Prince, R. P.; Knott, W. M., III; Sager, J. C.; Jones, J. D.

    1992-01-01

    The requirements for life support systems, both biological and physical-chemical, for long-term human attended space missions are under serious study throughout NASA. The KSC 'breadboard' project has focused on biomass production using higher plants for atmospheric regeneration and food production in a special biomass production chamber. This chamber is designed to provide information on food crop growth rate, contaminants in the chamber that alter plant growth requirements for atmospheric regeneration, carbon dioxide consumption, oxygen production, and water utilization. The shape and size, mass, and energy requirements in relation to the overall integrity of the biomass production chamber are under constant study.

  11. Precision Radio Frequency Anechoic Chamber Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Performs measurements and calibration of antennas for satellites and aircraft or groundbased systems. The chamber is primarily used for optimizing antenna...

  12. Bicone vacuum chamber for ISR intersection

    CERN Document Server

    1975-01-01

    This is one of the bicone chambers made of titanium for experiment R 702. The central corrugated part had a very thin titanium wall (0.28 mm). The first of these chambers collapsed in its central part when baked at 300 C (August 1975). After an intensive effort to develop better quality and reproducible welds for this special material, the ISR workshop was able to build two new chambers of this type. One of them was installed at I 7 for R 702 in 1976 and worked perfectly. It was at that time the most "transparent" intersection vacuum chamber. See also 7609219, 7609221.

  13. Generation and characterization of nano-tungsten carbide particles by wire explosion process

    Energy Technology Data Exchange (ETDEWEB)

    Debalina, B.; Kamaraj, M.; Murthy, B.S. [Dept. of Metallurgical and Materials Engg., IIT Madras, Chennai 600036 (India); Chakravarthi, S.R. [Dept. of Aerospace Engg, IIT Madras, Chennai 600036 (India); Sarathi, R., E-mail: rsarathi@iitm.ac.i [Dept. of Electrical Engineering, IIT Madras, Chennai 600036, Tamilnadu (India)

    2010-04-30

    The nano-tungsten carbide particles were produced by exploding tungsten conductor in different carburizing medium viz. carbon dioxide and methane atmosphere. The influence of gas pressure in explosion chamber on the size of the particles formed was analyzed. Methane gas was found to be a conducive medium to form tungsten carbide particles. Certain physico-chemical diagnostic studies such as wide angle X-ray diffraction (WAXD) and Fourier transform infra-red (FTIR) spectroscopy studies were carried out to characterize the nano-tungsten carbide powder produced by the wire explosion process. The size of the particles was measured by using transmission electron microscope (TEM) and its size distribution was analyzed by adopting log-normal distribution. Thermal conductivity of the gas plays a major role on the size of the particle formed by wire explosion process as observed in the present work.

  14. Consequences of air around an ionization chamber : Are existing solid phantoms suitable for reference dosimetry on an MR-linac?

    NARCIS (Netherlands)

    Hackett, S. L.; Van Asselen, B.; Wolthaus, J. W H; Kok, J. G M; Woodings, S. J.; Lagendijk, J. J W; Raaymakers, B. W.

    2016-01-01

    Purpose: A protocol for reference dosimetry for the MR-linac is under development. The 1.5 T magnetic field changes the mean path length of electrons in an air-filled ionization chamber but has little effect on the electron trajectories in a surrounding phantom. It is therefore necessary to correct

  15. A two-dose-rate method for general recombination correction for liquid ionization chambers in pulsed beams

    Energy Technology Data Exchange (ETDEWEB)

    Toelli, Heikki; Sjoegren, Rickard; Wendelsten, Mikael, E-mail: heikki.tolli@radfys.umu.s [Department of Radiation Sciences, Radiation Physics, Umeaa University, SE-901 85 Umeaa (Sweden)

    2010-08-07

    The correction for general recombination losses in liquid ionization chambers (LICs) is more complex than that in air-filled ionization chambers. The reason for this is that the saturation charge in LICs, i.e. the charge that escapes initial recombination, depends on the applied voltage. This paper presents a method, based on measurements at two different dose rates in a pulsed beam, for general recombination correction in LICs. The Boag theory for pulsed beams is used and the collection efficiency is determined by numerical methods which are equivalent to the two-voltage method used in dosimetry with air-filled ionization chambers. The method has been tested in experiments in water in a 20 MeV electron beam using two LICs filled with isooctane and tetramethylsilane. The dose per pulse in the electron beam was varied between 0.1 mGy/pulse and 8 mGy/pulse. The relative standard deviations of the collection efficiencies determined with the two-dose-rate method ranged between 0.1% and 1.5%. The dose-rate variations of the general recombination corrected charge measured with the LICs are in excellent agreement with the corresponding values obtained with an air-filled plane parallel ionization chamber.

  16. Experimental study of free abrasive wire sawing by using multi-strands wire

    Institute of Scientific and Technical Information of China (English)

    Yao Chunyan; Wang Jinsheng; Peng Wei; Jin Xin; Chen Shijie

    2013-01-01

    Grains in the slurry can be brought into cutting zone by steel wire with a certain speed to achieve the purpose of removing the workpiece material in the free abrasive wire sawing machining. Because its own of multi-strands characteristics,we use it to replace the steel wire to do slicing experiment. In this paper,multi-strands wire is made by seven metal wires and has many grooves on its surface. Compared with steel wire,it can carry more grains into cutting zone which is conducive to improving the slicing efficiency. We do some comparative slic-ing experiments by applying multi-strands wire (ϕ0.25 mm) and steel wire (ϕ0.25 mm) to cut optical glass (K9). The results show that slicing efficiency and the surface roughness of the workpiece sliced by using multi-strands wire are better than that by using steel wire,but the kerf width of the former is wider than that of the latter in the same experimental conditions.

  17. Evaluating the Effect of Dental Filling Material and Filling Depth on the Strength and Deformation of Filled Teeth

    Directory of Open Access Journals (Sweden)

    Seifollah Gholampour

    2016-10-01

    Full Text Available ackground and aim: It is important to evaluate the effect of the type of filling material on deformation and strength of tooth after filling and also the effect of filling depth on quality of restoration of a decayed tooth. Material and Methods: The Orthopantomogram (OPG of the first and second molars of a 28-year-old man was made and the teeth were 3D modeled. The stress-deformation analysis was then performed on the models in the three states of normal tooth, tooth filled with amalgam and tooth filled with composite using finite element method under a distributed load of 400N equivalent to chewing force. Two values (1/2 and 1/3 of the tooth height were considered for filling depth in the analyses. Results: The results showed that the normal first molar was exposed to a 7.2% greater risk of dental injuries compared to the normal second molar and also a greater stress is created in it when it is filled with composite. The first molar filled with a composite material is 13.7% weaker than the normal tooth while it is almost as strong as a normal tooth when it is filled with amalgam. The effect of the type of filling material on the strength and deformation of the second molar was trivial. Conclusion: Amalgam is a more proper dental filling material for the first molar although a 16.7% change in drilling depth is needed for tooth preparation. Dental filling material and filling depth have a small effect on the strength and deformation of filled second molars.

  18. Wire recycling for quantum circuit optimization

    Science.gov (United States)

    Paler, Alexandru; Wille, Robert; Devitt, Simon J.

    2016-10-01

    Quantum information processing is expressed using quantum bits (qubits) and quantum gates which are arranged in terms of quantum circuits. Here, each qubit is associated with a quantum circuit wire which is used to conduct the desired operations. Most of the existing quantum circuits allocate a single quantum circuit wire for each qubit and hence introduce significant overhead. In fact, qubits are usually not needed during the entire computation, only between their initialization and measurement. Before and after that, corresponding wires may be used by other qubits. In this work, we propose a solution which exploits this fact in order to optimize the design of quantum circuits with respect to the required wires. To this end, we introduce a representation of the lifetimes of all qubits which is used to analyze the respective need for wires. Based on this analysis, a method is proposed which "recycles" the available wires and, as a result, reduces the size of the resulting circuit. Numerical tests based on established reversible and fault-tolerant quantum circuits confirm that the proposed solution reduces the number of wires by more than 90% compared to unoptimized quantum circuits.

  19. A Low-Mass Drift Chamber System for the HADES-Spectrometer

    Science.gov (United States)

    Dohrmann, F.; Bethge, K.; Enghardt, W.; Fateev, O.; Garabatos, C.; Grosse, E.; Muentz, C.; Karig, W.; Koenig, W.; Smykov, L.; Sobiella, M.; Steigerwald, A.; Stelzer, H.; Stroth, J.; Wuestenfeld, J.; Zanewsky, Y.; Zentek, A.

    1998-11-01

    A new high resolution (Δ M/M < 1%) and high acceptance (45%) di-electron spectrometer (HADES) has been designed to investigate in-medium properties of hadrons. For tracking of all charged particles (in particular with sufficient resolution for electrons) a system of 24 low-mass drift chambers (Helium based counting gas and Aluminum field and cathode wires), arranged in four tracking planes, is used. Design aspects of the chambers are reported. Results of performance optimization using various prototype detectors are discussed, including results of an ageing test. Stable operation in the high-multiplicity environment of heavy ion collisions, and a spatial resolution of 70 μ m(σ) over 80% of a cell have been demonstrated in two beam experiments.

  20. Drift chamber electronics with multi-hit capability for time and current division measurements

    Energy Technology Data Exchange (ETDEWEB)

    Manarin, A.; Pregernig, L.; Rabany, M.; Saban, R.; Vismara, G.

    1983-11-15

    Drift chambers have been installed for luminosity measurements in intersection 5 of the SPS accelerator working in panti p colliding mode. The required electronics is described. The system is able to process up to 16 hits per wire with a double pulse resolution of 40 ns; drift time and current division, with 1.25 ns and 1.6% resolution respectively, are recorded. Transconductance preamplifiers and discriminators are directly mounted on the chamber; 160 m of twisted-apir cable bring the signals to the digitizer unit. Coarse time is measured using RAM techniques, while fine time is obtained by means of a microstrip delay associated with a 100 K ECL priority encoder. Current division used a single 50 MHz Flash ADC which alows 26 dB dynamic range with 6 bit resolution. First operational results are reported.

  1. Calibration of the borated ion chamber at NIST reactor thermal column.

    Science.gov (United States)

    Wang, Z; Hertel, N E; Lennox, A

    2007-01-01

    In boron neutron capture therapy and boron neutron capture enhanced fast neutron therapy, the absorbed dose of tissue due to the boron neutron capture reaction is difficult to measure directly. This dose can be computed from the measured thermal neutron fluence rate and the (10)B concentration at the site of interest. A borated tissue-equivalent (TE) ion chamber can be used to directly measure the boron dose in a phantom under irradiation by a neutron beam. Fermilab has two Exradin 0.5 cm(3) Spokas thimble TE ion chambers, one loaded with boron, available for such measurements. At the Fermilab Neutron Therapy Facility, these ion chambers are generally used with air as the filling gas. Since alpha particles and lithium ions from the (10)B(n,alpha)(7)Li reactions have very short ranges in air, the Bragg-Gray principle may not be satisfied for the borated TE ion chamber. A calibration method is described in this paper for the determination of boron capture dose using paired ion chambers. The two TE ion chambers were calibrated in the thermal column of the National Institute of Standards and Technology (NIST) research reactor. The borated TE ion chamber is loaded with 1,000 ppm of natural boron (184 ppm of (10)B). The NIST thermal column has a cadmium ratio of greater than 400 as determined by gold activation. The thermal neutron fluence rate during the calibration was determined using a NIST fission chamber to an accuracy of 5.1%. The chambers were calibrated at two different thermal neutron fluence rates: 5.11 x 10(6) and 4.46 x 10(7)n cm(-2) s(-1). The non-borated ion chamber reading was used to subtract collected charge not due to boron neutron capture reactions. An optically thick lithium slab was used to attenuate the thermal neutrons from the neutron beam port so the responses of the chambers could be corrected for fast neutrons and gamma rays in the beam. The calibration factor of the borated ion chamber was determined to be 1.83 x 10(9) +/- 5.5% (+/- 1sigma) n

  2. Space Station Freedom secondary power wiring requirements

    Science.gov (United States)

    Sawyer, C. R.

    1994-09-01

    Secondary power is produced by DDCU's (direct current to direct current converter units) and routed to and through secondary power distribution assemblies (SPDA's) to loads or tertiary distribution assemblies. This presentation outlines requirements of Space Station Freedom (SSF) EEE (electrical, electronic, and electromechanical) parts wire and the approved electrical wire and cable. The SSF PDRD (Program Definition and Requirements Document) language problems and resolution are reviewed. The cable routing to and from the SPDA's is presented as diagrams and the wire recommendations and characteristics are given.

  3. Diastolic filling dynamics in patients with aortic stenosis.

    Science.gov (United States)

    Murakami, T; Hess, O M; Gage, J E; Grimm, J; Krayenbuehl, H P

    1986-06-01

    Left ventricular filling dynamics were investigated in 24 patients with aortic stenosis (AS). Biplane cineangiography was performed with simultaneous micromanometry in these 24 patients and in six control subjects. Twelve of the patients with AS had moderate hypertrophy with a left ventricular muscle mass index of less than 180 g/m2 (ASI group) and 12 had severe hypertrophy with an index of 180 g/m2 or more (AS2 group). Filling dynamics were also evaluated postoperatively in eight patients in the AS1 and six patients in the AS2 group. Preoperatively, end-diastolic and end-systolic volume indexes were larger and ejection fraction was lower in the AS2 compared with the control or AS1 group. Percent volume increase during the first half of diastole (%V1) was smaller in the AS1 than in the AS2 group. Peak filling rate in the first half of diastole (PFR 1) was higher in the AS2 than in the control or in AS1 group, while peak filling rate in the second half of diastole (PFR2) was considerably greater in the AS1 group than in the other two groups. The time constant of left ventricular pressure decline, an index of the rate of relaxation, was prolonged in the AS2 group. In contrast, mitral valve opening pressure (MVOP) was significantly higher in this group than in the other two groups. The constant of left ventricular chamber stiffness was slightly but not significantly greater in both AS groups than in the control subjects. After surgery in patients in the AS1 group, preoperatively reduced %V1 had increased and preoperatively enhanced PFR2 had decreased. In patients in the AS2 group, excluding one with a persistent low ejection fraction after surgery, preoperatively enhanced PFR1 decreased in association with a decrease in MVOP. Thus, left ventricular filling dynamics vary in patients with AS depending on the degree of left ventricular hypertrophy and systolic function. In patients with AS and moderate hypertrophy %V1 is slightly reduced but is compensated for by a

  4. Fluid dynamics of ventricular filling in the embryonic heart.

    Science.gov (United States)

    Miller, Laura A

    2011-09-01

    The vertebrate embryonic heart first forms as a valveless tube that pumps blood using waves of contraction. As the heart develops, the atrium and ventricle bulge out from the heart tube, and valves begin to form through the expansion of the endocardial cushions. As a result of changes in geometry, conduction velocities, and material properties of the heart wall, the fluid dynamics and resulting spatial patterns of shear stress and transmural pressure change dramatically. Recent work suggests that these transitions are significant because fluid forces acting on the cardiac walls, as well as the activity of myocardial cells that drive the flow, are necessary for correct chamber and valve morphogenesis. In this article, computational fluid dynamics was used to explore how spatial distributions of the normal forces acting on the heart wall change as the endocardial cushions grow and as the cardiac wall increases in stiffness. The immersed boundary method was used to simulate the fluid-moving boundary problem of the cardiac wall driving the motion of the blood in a simplified model of a two-dimensional heart. The normal forces acting on the heart walls increased during the period of one atrial contraction because inertial forces are negligible and the ventricular walls must be stretched during filling. Furthermore, the force required to fill the ventricle increased as the stiffness of the ventricular wall was increased. Increased endocardial cushion height also drastically increased the force necessary to contract the ventricle. Finally, flow in the moving boundary model was compared to flow through immobile rigid chambers, and the forces acting normal to the walls were substantially different.

  5. Raymond J. Chambers--A Personal Reflection

    Science.gov (United States)

    Gaffikin, Michael

    2012-01-01

    This paper is presented as a tribute to Raymond J. Chambers. As its title suggests, it is a personal reflection through the eyes of someone who worked closely with him over a period of 10 years during a latter part of his career, and who completed a doctoral thesis with aspects of the work of Chambers as its subject. During this time, author…

  6. Results from the MAC Vertex chamber

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, H.N.

    1987-05-01

    The design, construction, and performance characteristics of a high precision gaseous drift chamber made of thin walled proportional tubes are described. The device achieved an average spatial resolution of 45 ..mu..m in use for physics analysis with the MAC detector. The B-lifetime result obtained with this chamber is discussed.

  7. 21 CFR 866.2120 - Anaerobic chamber.

    Science.gov (United States)

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a device intended for medical purposes to maintain an anaerobic...

  8. Supersonic Jet Interactions in a Plenum Chamber

    Directory of Open Access Journals (Sweden)

    K. M. Venugopal

    2004-07-01

    Full Text Available Understanding thè supersonic jet interactions in a plenum chamber is essential for thè design of hot launch systems. Static tests were conducted in a small-scale rocket motor ioaded with a typical nitramine propellaiit to produce a nozzle exit Mach number of 3. This supersonic jet is made to interact with plenum chambers having both open and closed sides. The distance between thè nozzle exit and thè back piate of plenum chamber are varied from 2. 5 to 7. 0 times thè nozzle exit diameter. The pressure rise in thè plenum chamber was measured using pressure transducers mounted at different locatìons. The pressure-time data were analysed to obtain an insight into thè flow field in thè plenum chamber. The maximum pressure exerted on thè back piate of plenum chamber is about 25-35 per cent. of thè maximum stagnation pressure developed in thè rocket motor. Ten static tests were carried out to obtain thè effect of axial distance between thè nozzle exit and thè plenum chamber back piate, and stagnation pressure in thè rocket motoron thè flow field in thè open-sided and closed-sided plenum chambers configurations.

  9. An ionization chamber with magnetic levitated electrodes

    CERN Document Server

    Kawaguchi, T

    1999-01-01

    A new type of ionization chamber which has magnetically levitated electrodes has been developed. The electrodes are supplied voltages for the repelling of ions by a battery which is also levitated with the electrodes. The characteristics of this ionization chamber are investigated in this paper.

  10. ME1/1 Cathode Strip Chambers

    CERN Document Server

    Erchov, Yu V; Kamenev, Alexey; Karjavin, Vladimir; Khabarov, Serguei; Moissenz, P V; Moissenz, K P; Movchan, Sergey; Perelygin, Victor; Vassiliev, S E; Zarubin, Anatoli; Tchekhovski, V A

    2008-01-01

    The 76 innermost ME1/1 cathode strip chambers (CSC) of the CMS Experiment were designed and produced in Dubna. The chambers have been installed in the detector and commissioning has been completed. This paper describes the design of the CSCs, their main mechanical parameters and read-out electronics, and the results of tests with cosmic-ray muons.

  11. HVAC&R Equipment Environmental Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — Description:Large "Truck" ChamberThe large "truck" chamber provides controlled air conditions from -7 °C (20 °F) to 65 °C (150 °F).Air-Conditioner and Heat Pump Test...

  12. Magma Chambers, Thermal Energy, and the Unsuccessful Search for a Magma Chamber Thermostat

    Science.gov (United States)

    Glazner, A. F.

    2015-12-01

    Although the traditional concept that plutons are the frozen corpses of huge, highly liquid magma chambers ("big red blobs") is losing favor, the related notion that magma bodies can spend long periods of time (~106years) in a mushy, highly crystalline state is widely accepted. However, analysis of the thermal balance of magmatic systems indicates that it is difficult to maintain a significant portion in a simmering, mushy state, whether or not the system is eutectic-like. Magma bodies cool primarily by loss of heat to the Earth's surface. The balance between cooling via energy loss to the surface and heating via magma accretion can be denoted as M = ρLa/q, where ρ is magma density, L is latent heat of crystallization, a is the vertical rate of magma accretion, and q is surface heat flux. If M>1, then magma accretion outpaces cooling and a magma chamber forms. For reasonable values of ρ, L, and q, the rate of accretion amust be > ~15 mm/yr to form a persistent volume above the solidus. This rate is extremely high, an order of magnitude faster than estimated pluton-filling rates, and would produce a body 10 km thick in 700 ka, an order of magnitude faster than geochronology indicates. Regardless of the rate of magma supply, the proportion of crystals in the system must vary dramatically with depth at any given time owing to transfer of heat. Mechanical stirring (e.g., by convection) could serve to homogenize crystal content in a magma body, but this is unachievable in crystal-rich, locked-up magma. Without convection the lower part of the magma body becomes much hotter than the top—a process familiar to anyone who has scorched a pot of oatmeal. Thermal models that succeed in producing persistent, large bodies of magma rely on scenarios that are unrealistic (e.g., omitting heat loss to the planet's surface), self-fulfilling prophecies (e.g., setting unnaturally high temperatures as fixed boundary conditions), or physically unreasonable (e.g., magma is intruded

  13. 7 CFR 1755.506 - Aerial wire services

    Science.gov (United States)

    2010-01-01

    ...), Specifications and Drawings for Service Installations at Customer Access Locations. The wire used for aerial... service wire spans. (d) Aerial service wires shall be run in accordance with the construction drawings... aerial service wires at poles shall be as illustrated in construction drawings 503-2 and 504 contained in...

  14. Diamagnetism in wire medium metamaterials: theory and experiment

    CERN Document Server

    Yagupov, Ilya; Kosulnikov, Sergei; Hasan, Mehedi; Iorsh, Ivan; Belov, Pavel

    2015-01-01

    Strong diamagnetic response of wire medium with finite wire radius is reported. Contrary to the previous works where it was assumed that the wire medium exhibits only the electric response, we show that the non-zero magnetic susceptibility has to be taken into account for proper effective medium description of the wire medium. Analytical and numerical results are supported by the experimental measurements.

  15. Modelling aluminium wire bond reliability in high power OMP devices

    NARCIS (Netherlands)

    Kregting, R.; Yuan, C.A.; Xiao, A.; Bruijn, F. de

    2011-01-01

    In a RF power application such as the OMP, the wires are subjected to high current (because of the high power) and high temperature (because of the heat from IC and joule-heating from the wire itself). Moreover, the wire shape is essential to the RF performance. Hence, the aluminium wire is preferre

  16. 47 CFR 76.804 - Disposition of home run wiring.

    Science.gov (United States)

    2010-10-01

    ... in service to subscribers to the extent possible. (b) Unit-by-unit disposition of home run wiring: (1... 47 Telecommunication 4 2010-10-01 2010-10-01 false Disposition of home run wiring. 76.804 Section... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Inside Wiring § 76.804 Disposition of home run wiring....

  17. 30 CFR 56.12053 - Circuits powered from trolley wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuits powered from trolley wires. 56.12053... § 56.12053 Circuits powered from trolley wires. Ground wires for lighting circuits powered from trolley wires shall be connected securely to the ground-return circuit....

  18. 30 CFR 57.12053 - Circuits powered from trolley wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuits powered from trolley wires. 57.12053... Electricity Surface and Underground § 57.12053 Circuits powered from trolley wires. Ground wires for lighting circuits powered from trolley wires shall be connected securely to the ground return circuit. Surface Only...

  19. The SAMURAI Time Projection Chamber

    Science.gov (United States)

    Dye, Steven

    2011-10-01

    The SAMURAI Time Projection Chamber (TPC) will be used to study particle collisions by colliding a beam of particles with a stationary gas which will be contained in a field cage inside the TPC. When the beam collides with the gas, charged particles are accelerated into the pad plane by an electric field. The paths of these particles will be curved by a magnetic field created by the SAMURAI magnet at the RIKEN facility in Japan. The charged particles will then collide with the pad plane which will be located on the bottom of the TPC. The pad plane will take these collisions and create electrical signals and send them to supporting electronics where the data can be interpreted. The TPC will be used to help determine the Equation of State for asymmetric nuclear matter. Measurements of neutron, proton, 3H and 3He flow will be taken with the NEBULA array which consists of nebula scintillators. The poster will contain information on the laser calibration system and the electronics that will be used for the TPC. The electronics used are the same electronics used in the STAR TPC experiment.

  20. Tunable permeability of magnetic wires at microwaves

    Science.gov (United States)

    Panina, L. V.; Makhnovskiy, D. P.; Morchenko, A. T.; Kostishin, V. G.

    2015-06-01

    This paper presents the analysis into microwave magnetic properties of magnetic microwires and their composites in the context of applications in wireless sensors and tunable microwave materials. It is demonstrated that the intrinsic permeability of wires has a wide frequency dispersion with relatively large values in the GHz band. In the case of a specific magnetic anisotropy this results in a tunable microwave impedance which could be used for distributed wireless sensing networks in functional composites. The other range of applications is related with developing the artificial magnetic dielectrics with large and tunable permeability. The composites with magnetic wires with a circumferential anisotropy have the effective permeability which differs substantially from unity for a relatively low concentration (less than 10%). This can make it possible to design the wire media with a negative and tunable index of refraction utilising natural magnetic properties of wires.