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Sample records for he-3 proportional counters

  1. Independent Measurement of the Total Active B8 Solar Neutrino Flux Using an Array of He3 Proportional Counters at the Sudbury Neutrino Observatory

    Science.gov (United States)

    Aharmim, B.; Ahmed, S. N.; Amsbaugh, J. F.; Anthony, A. E.; Banar, J.; Barros, N.; Beier, E. W.; Bellerive, A.; Beltran, B.; Bergevin, M.; Biller, S. D.; Boudjemline, K.; Boulay, M. G.; Bowles, T. J.; Browne, M. C.; Bullard, T. V.; Burritt, T. H.; Cai, B.; Chan, Y. D.; Chauhan, D.; Chen, M.; Cleveland, B. T.; Cox-Mobrand, G. A.; Currat, C. A.; Dai, X.; Deng, H.; Detwiler, J.; Dimarco, M.; Doe, P. J.; Doucas, G.; Drouin, P.-L.; Duba, C. A.; Duncan, F. A.; Dunford, M.; Earle, E. D.; Elliott, S. R.; Evans, H. C.; Ewan, G. T.; Farine, J.; Fergani, H.; Fleurot, F.; Ford, R. J.; Formaggio, J. A.; Fowler, M. M.; Gagnon, N.; Germani, J. V.; Goldschmidt, A.; Goon, J. T. M.; Graham, K.; Guillian, E.; Habib, S.; Hahn, R. L.; Hallin, A. L.; Hallman, E. D.; Hamian, A. A.; Harper, G. C.; Harvey, P. J.; Hazama, R.; Heeger, K. M.; Heintzelman, W. J.; Heise, J.; Helmer, R. L.; Henning, R.; Hime, A.; Howard, C.; Howe, M. A.; Huang, M.; Jagam, P.; Jamieson, B.; Jelley, N. A.; Keeter, K. J.; Klein, J. R.; Kormos, L. L.; Kos, M.; Krüger, A.; Kraus, C.; Krauss, C. B.; Kutter, T.; Kyba, C. C. M.; Lange, R.; Law, J.; Lawson, I. T.; Lesko, K. T.; Leslie, J. R.; Loach, J. C.; MacLellan, R.; Majerus, S.; Mak, H. B.; Maneira, J.; Martin, R.; McBryde, K.; McCauley, N.; McDonald, A. B.; McGee, S.; Mifflin, C.; Miller, G. G.; Miller, M. L.; Monreal, B.; Monroe, J.; Morissette, B.; Myers, A.; Nickel, B. G.; Noble, A. J.; Oblath, N. S.; O'Keeffe, H. M.; Ollerhead, R. W.; Gann, G. D. Orebi; Oser, S. M.; Ott, R. A.; Peeters, S. J. M.; Poon, A. W. P.; Prior, G.; Reitzner, S. D.; Rielage, K.; Robertson, B. C.; Robertson, R. G. H.; Rollin, E.; Schwendener, M. H.; Secrest, J. A.; Seibert, S. R.; Simard, O.; Simpson, J. J.; Sinclair, L.; Skensved, P.; Smith, M. W. E.; Steiger, T. D.; Stonehill, L. C.; Tešić, G.; Thornewell, P. M.; Tolich, N.; Tsui, T.; Tunnell, C. D.; van Wechel, T.; van Berg, R.; Vandevender, B. A.; Virtue, C. J.; Walker, T. J.; Wall, B. L.; Waller, D.; Tseung, H. Wan Chan; Wendland, J.; West, N.; Wilhelmy, J. B.; Wilkerson, J. F.; Wilson, J. R.; Wouters, J. M.; Wright, A.; Yeh, M.; Zhang, F.; Zuber, K.

    2008-09-01

    The Sudbury Neutrino Observatory (SNO) used an array of He3 proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (νx) B8 solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54-0.31+0.33(stat)-0.34+0.36(syst)×106cm-2s-1, in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Δm2=7.59-0.21+0.19×10-5eV2 and θ=34.4-1.2+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO’s previous results.

  2. Proportional counter radiation camera

    Science.gov (United States)

    Borkowski, C.J.; Kopp, M.K.

    1974-01-15

    A gas-filled proportional counter camera that images photon emitting sources is described. A two-dimensional, positionsensitive proportional multiwire counter is provided as the detector. The counter consists of a high- voltage anode screen sandwiched between orthogonally disposed planar arrays of multiple parallel strung, resistively coupled cathode wires. Two terminals from each of the cathode arrays are connected to separate timing circuitry to obtain separate X and Y coordinate signal values from pulse shape measurements to define the position of an event within the counter arrays which may be recorded by various means for data display. The counter is further provided with a linear drift field which effectively enlarges the active gas volume of the counter and constrains the recoil electrons produced from ionizing radiation entering the counter to drift perpendicularly toward the planar detection arrays. A collimator is interposed between a subject to be imaged and the counter to transmit only the radiation from the subject which has a perpendicular trajectory with respect to the planar cathode arrays of the detector. (Official Gazette)

  3. The microstrip proportional counter

    Science.gov (United States)

    Ramsey, B. D.

    1992-01-01

    Microstrip detectors in which the usual discrete anode and cathode wires are replaced by conducting strips on an insulating or partially insulating substrate are fabricated using integrated circuit-type photolithographic techniques and hence offer very high spatial accuracy and uniformity, together with the capability of producing extremely fine electrode structures. Microstrip proportional counters have now been variously reported having an energy resolution of better than 11 percent FWHM at 5.9 keV. They have been fabricated with anode bars down to 2 microns and on a variety of substrate materials including thin films which can be molded to different shapes. This review will examine the development of the microstrip detector with emphasis on the qualities which make this detector particularly interesting for use in astronomy.

  4. Measuring Cherenkov Backgrounds from Proportional Counters in SNO

    Science.gov (United States)

    Seibert, Stanley

    2006-04-01

    In the current phase of operation of the Sudbury Neutrino Observatory, He-3 proportional counters have been deployed in the center of the detector to measure neutron production from neutral-current interactions between neutrinos and deuterons in the heavy water. Radioactive decays of Bi-214 and Tl-208 in the counters produce gammas of sufficient energy to photodisintegrate deuterons, which become a background to the neutral current measurement. We have measured the background rate in-situ using Cherenkov light detected with SNO's 9456 inward-looking photomultiplier tubes. A maximum likelihood method is used to separate backgrounds in the heavy water from backgrounds in the proportional counters based upon the spatial distribution of low energy Cherenkov event vertices. Uncertainties on the backgrounds have been estimated using calibration data taken with both a distributed Na-24 source, and a contained Th source deployed at various points in the detector.

  5. Neutron spectroscopy with the Spherical Proportional Counter

    CERN Document Server

    Bougamont, E; Derre, J; Galan, J; Gerbier, G; Giomataris, I; Gros, M; Katsioulas, I; Jourde, D; Magnier, P; Navick, X F; Papaevangelou, T; Savvidis, I; Tsiledakis, G

    2015-01-01

    A novel large volume spherical proportional counter, recently developed, is used for neutron measurements. Gas mixtures of $N_{2}$ with $C_{2}H_{6}$ and pure $N_{2}$ are studied for thermal and fast neutron detection, providing a new way for the neutron spectroscopy. The neutrons are detected via the ${}^{14}N(n, p)C^{14}$ and ${}^{14}N(n, \\alpha)B^{11}$ reactions. Here we provide studies of the optimum gas mixture, the gas pressure and the most appropriate high voltage supply on the sensor of the detector in order to achieve the maximum amplification and better resolution. The detector is tested for thermal and fast neutrons detection with a ${}^{252}Cf$ and a ${}^{241}Am-{}^{9}Be$ neutron source. The atmospheric neutrons are successfully measured from thermal up to several MeV, well separated from the cosmic ray background. A comparison of the spherical proportional counter with the current available neutron counters is also given.

  6. Absolute calibration of TFTR helium proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, J.D.; Diesso, M.; Jassby, D.; Johnson, L.; McCauley, S.; Munsat, T.; Roquemore, A.L. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Barnes, C.W. [Princeton Univ., NJ (United States). Plasma Physics Lab.]|[Los Alamos National Lab., NM (United States); Loughlin, M. [Princeton Univ., NJ (United States). Plasma Physics Lab.]|[JET Joint Undertaking, Abingdon (United Kingdom)

    1995-06-01

    The TFTR helium proportional counters are located in the central five (5) channels of the TFTR multichannel neutron collimator. These detectors were absolutely calibrated using a 14 MeV neutron generator positioned at the horizontal midplane of the TFTR vacuum vessel. The neutron generator position was scanned in centimeter steps to determine the collimator aperture width to 14 MeV neutrons and the absolute sensitivity of each channel. Neutron profiles were measured for TFTR plasmas with time resolution between 5 msec and 50 msec depending upon count rates. The He detectors were used to measure the burnup of 1 MeV tritons in deuterium plasmas, the transport of tritium in trace tritium experiments, and the residual tritium levels in plasmas following 50:50 DT experiments.

  7. Microstrip proportional counter development at MSFC

    Science.gov (United States)

    Fulton, M. A.; Kolodziejczak, J. J.; Ramsey, B. D.

    1992-01-01

    Microstrip detectors are an exciting new development in proportional counter design fabricated using integrated circuit-type photolithography techniques; they therefore offer very high spatial accuracy and uniformity. A development program is underway at NASA-Marshall to produce large-area microstrips for use in an X-ray detector balloon flight program and to investigate the general performance limits of these new devices. Microstrips tested so far have been fabricated both in-house using standard photolithographic techniques and by an outside contractor using electron beam technology. Various substrate materials have been tested along with different electrode configurations. The distributions of pickup on subdivided cathodes on both top and bottom surfaces of the microstrips are also being investigated for use as two-dimensional imaging detectors. Data from these tests in the development of a large-area device will be presented.

  8. A Gas Proportional Scintillation Counter with krypton filling

    Science.gov (United States)

    Monteiro, C. M. B.; Mano, R. D. P.; Barata, E. C. G. M.; Fernandes, L. M. P.; Freitas, E. D. C.

    2016-12-01

    A Gas Proportional Scintillation Counter filled with pure krypton was studied. Energy resolution below 10% for 5.9-keV X-rays was obtained with this prototype. This value is much better than the energy resolution obtained with proportional counters or other MPGDs with krypton filling. The krypton electroluminescence scintillation and ionisation thresholds were found to be about 0.5 and 3.5 kV cm-1bar-1, respectively.

  9. Full simulation of the Sudbury Neutrino Observatory proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Beltran, B; Habib, S; Hallin, A L [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); Bichsel, H; Cox, G A; Formaggio, J A; McGee, S; Miller, M L; Oblath, N S [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Cai, B; Kraus, C; Leslie, H R; Martin, R [Department of Physics, Queen' s University, Kingston, Ontario K7L 3N6 (Canada); Deng, H [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104-6396 (United States); Detwiler, J; Loach, J C [Institute for Nuclear and Particle Astrophysics and Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Hime, A [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Huang, M [Department of Physics, University of Texas at Austin, Austin, TX 78712-0264 (United States); Monreal, B; Monroe, J, E-mail: nsoblath@mit.edu [Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2011-07-15

    The third phase of the Sudbury Neutrino Observatory (SNO) experiment added an array of {sup 3}He proportional counters to the detector. The purpose of this neutral-current detection (NCD) array was to observe neutrons resulting from neutral-current solar-neutrino-deuteron interactions. We have developed a detailed simulation of current pulses from NCD array proportional counters, from the primary neutron capture on {sup 3}He through NCD array signal-processing electronics. This NCD array MC simulation was used to model the alpha-decay background in SNO's third-phase {sup 8}B solar-neutrino measurement.

  10. Full simulation of the Sudbury Neutrino Observatory proportional counters

    CERN Document Server

    Beltran, B; Cai, B.; Cox, G.A.; Deng, H.; Detwiler, J.; Formaggio, J.A.; Habib, S.; Hallin, A.L.; Hime, A.; Huang, M.; Kraus, C.; Leslie, H.R.; Loach, J.C.; Martin, R.; McGee, S.; Miller, M.L.; Monreal, B.; Monroe, J.; Oblath, N.S.; Peeters, S.J.M.; Poon, A.W.P.; Prior, G.; Rielage, K.; Robertson, R.G.H.; Smith, M.W.E.; Stonehill, L.C.; Tolich, N.; Van Wechel, T.; Wan Chan Tseung, H.; Wendland, J.; Wilkerson, J.F.; Wright, A.

    2011-01-01

    The third phase of the Sudbury Neutrino Observatory (SNO) experiment added an array of 3He proportional counters to the detector. The purpose of this Neutral Current Detection (NCD) array was to observe neutrons resulting from neutral-current solar neutrino-deuteron interactions. We have developed a detailed simulation of the current pulses from the NCD array proportional counters, from the primary neutron capture on 3He through the NCD array signal-processing electronics. This NCD array Monte Carlo simulation was used to model the alpha-decay background in SNO's third-phase 8B solar-neutrino measurement.

  11. Event identification in 3He proportional counters using risetime discrimination

    Science.gov (United States)

    Langford, T. J.; Bass, C. D.; Beise, E. J.; Breuer, H.; Erwin, D. K.; Heimbach, C. R.; Nico, J. S.

    2013-07-01

    We present a straightforward method for particle identification and background rejection in 3He proportional counters for use in neutron detection. By measuring the risetime and pulse height of the preamplifier signals, one may define a region in the risetime versus pulse height space where the events are predominately from neutron interactions. For six proportional counters surveyed in a low-background environment, we demonstrate the ability to reject alpha-particle events with an efficiency of 99%. By applying the same method, we also show an effective rejection of microdischarge noise events that, when passed through a shaping amplifier, are indistinguishable from physical events in the counters. The primary application of this method is in measurements where the signal-to-background for counting neutrons is very low, such as in underground laboratories.

  12. Event Identification in $^3$He Proportional Counters Using Risetime Discrimination

    CERN Document Server

    Langford, T J; Beise, E J; Breuer, H; Erwin, D K; Heimbach, C R; Nico, J S

    2012-01-01

    We present a straightforward method for particle identification and background rejection in $^3$He proportional counters for use in neutron detection. By measuring the risetime and pulse height of the preamplifier signals, one may define a region in the risetime versus pulse height space where the events are predominately from neutron interactions. For six proportional counters surveyed in a low-background environment, we demonstrate the ability to reject alpha-particle events with an efficiency of 99%. By applying the same method, we also show an effective rejection of microdischarge noise events that, when passed through a shaping amplifier, are indistinguishable from physical events in the counters. The primary application of this method is in measurements where the signal-to-background for counting neutrons is very low, such as in underground laboratories.

  13. Development of proportional counters using photosensitive gases and liquids

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, D.F.

    1984-10-01

    An introduction to the history and to the principle of operation of wire chambers using photosensitive gases and liquids is presented. Their use as light sensors coupled to Gas Scintillation Proportional Counters and BaF/sub 2/, as well as their use in Cherenkov Ring imaging, is discussed in some detail. 42 references, 21 figures.

  14. Measurements of electron attachment by oxygen molecule in proportional counter

    Science.gov (United States)

    Tosaki, M.; Kawano, T.; Isozumi, Y.

    2013-11-01

    We present pulse height measurements for 5-keV Auger electrons from a radioactive 55Fe source mounted at the inner cathode surface of cylindrical proportional counter, which is operated with CH4 admixed dry air or N2. A clear shift of the pulse height has been observed by varying the amount of the admixtures; the number of electrons, created in the primary ionization by Auger electrons, is decreased by the electron attachment of the admixtures during their drift from the place near the source to the anode wire. The large gas amplification (typically 104) in the secondary ionization of proportional counter makes it possible to investigate a small change in the number of primary electrons. The electron attenuation cross-section of O2 has been evaluated by analyzing the shifts of the pulse height caused by the electron attachment to dry air and N2.

  15. Measurements of electron attachment by oxygen molecule in proportional counter

    Energy Technology Data Exchange (ETDEWEB)

    Tosaki, M., E-mail: tosaki.mitsuo.3v@kyoto-u.ac.jp [Radioisotope Research Center, Kyoto University, Kyoto 606-8501 (Japan); Kawano, T. [National Institute for Fusion Science, 322-6 Oroshi, Toki 509-5292 (Japan); Isozumi, Y. [Radioisotope Research Center, Kyoto University, Kyoto 606-8501 (Japan)

    2013-11-15

    We present pulse height measurements for 5-keV Auger electrons from a radioactive {sup 55}Fe source mounted at the inner cathode surface of cylindrical proportional counter, which is operated with CH{sub 4} admixed dry air or N{sub 2}. A clear shift of the pulse height has been observed by varying the amount of the admixtures; the number of electrons, created in the primary ionization by Auger electrons, is decreased by the electron attachment of the admixtures during their drift from the place near the source to the anode wire. The large gas amplification (typically 10{sup 4}) in the secondary ionization of proportional counter makes it possible to investigate a small change in the number of primary electrons. The electron attenuation cross-section of O{sub 2} has been evaluated by analyzing the shifts of the pulse height caused by the electron attachment to dry air and N{sub 2}.

  16. Proportional counter for X-ray analysis of lunar and planetary surfaces. [a position sensitive scintillating imaging proportional counter

    Science.gov (United States)

    1979-01-01

    A position sensitive proportional scintillation detector was developed and evaluated for use in applications involving X-ray imaging as well as spectroscopy. Topics covered include limitations of the proportional scintillation counter for use in space; purification of the xenon gas in the detector, and the operation of the detector system. Results show that the light signal in a proportional scintillation detector remains well localized. With modest electric fields in xenon, the primary electrons from a photoelectric absorption of an X-ray can be brought a distance of a few millimeters to a higher field region without spreading more than a millimeter or so. Therefore, it is possible to make a proportional scintillation detector with good position sensitivity that could be used to calibrate out the difference in light collection over its sensitive volume.

  17. Compact multiwire proportional counters for the detection of fission fragments.

    Science.gov (United States)

    Jhingan, Akhil; Sugathan, P; Golda, K S; Singh, R P; Varughese, T; Singh, Hardev; Behera, B R; Mandal, S K

    2009-12-01

    Two large area multistep position sensitive (two dimensional) multiwire proportional counters have been developed for experiments involving study of fission dynamics using general purpose scattering chamber facility at IUAC. Both detectors have an active area of 20x10 cm(2) and provide position signals in horizontal (X) and vertical (Y) planes, timing signal for time of flight measurements and energy signal giving the differential energy loss in the active volume. The design features are optimized for the detection of low energy heavy ions at very low gas pressures. Special care was taken in setting up the readout electronics, constant fraction discriminators for position signals in particular, to get optimum position and timing resolutions along with high count rate handling capability of low energy heavy ions. A custom made charge sensitive preamplifier, having lower gain and shorter decay time, has been developed for extracting the differential energy loss signal. The position and time resolutions of the detectors were determined to be 1.1 mm full width at half maximum (FWHM) and 1.7 ns FWHM, respectively. The detector could handle heavy ion count rates exceeding 20 kHz without any breakdown. Time of flight signal in combination with differential energy loss signal gives a clean separation of fission fragments from projectile and target like particles. The timing and position signals of the detectors are used for fission coincidence measurements and subsequent extraction of their mass, angular, and total kinetic energy distributions. This article describes systematic study of these fission counters in terms of efficiency, time resolution, count rate handling capability, position resolution, and the readout electronics. The detector has been operated with both five electrode geometry and four electrode geometry, and a comparison has been made in their performances.

  18. Large-area proportional counter for in situ transuranic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Miller, K.M.

    1994-12-31

    Improved methods for site characterization are desired for environmental restoration at nuclear facilities. Measurements of transuranics, in particular several isotopes of plutonium, are especially difficult due to the low penetrating nature of the radiations involved, namely, alpha particles and X rays. The effects of attenuation by soil and vegetation generally render direct alpha survey methods useless. For this reason, thin scintillators, such as the FIDLER (field instrument for detection of low-energy radiation) or its more sophisticated successor, the VIOLINIST, that rely on the detection of the L shell X rays (13 to 21 keV) are used for survey work. Semiconductor detectors (germanium and silicon), used singly or in arrays, can be effective, especially for situations where {sup 241}Am (60 keV) is present in the isotropic mix. In principle, in situ spectrometric techniques that have been successfully applied at higher photon energies for the measurement of gamma-emitting radionuclides in the environment can be extended to the X-ray region as well. For situations where {sup 241}Am is not present or its ratio to plutonium is unknown, an alternative detector that we have explored for in situ X-ray spectrometry is a large-area proportional counter (LAPC). These instruments were developed for X-ray astronomical measurements in space and offer the combination of large window area and medium energy resolution. Smaller versions have also been used for lung counting.

  19. Low energy recoil detection with a spherical proportional counter

    CERN Document Server

    Savvidis, I; Eleftheriadis, C; Giomataris, I; Papaevangellou, T

    2016-01-01

    We present low energy recoil detection results in the keV energy region, from measurements performed with the Spherical Proportional Counter (SPC). An ${}^{241}Am-{}^{9}{Be}$ fast neutron source is used in order to obtain neutron-nucleus elastic scattering events inside the gaseous volume of the detector. The detector performance in the $keV$ energy region was resolved by observing the $5.9\\ keV$ line of a ${}^{55}Fe$ X-ray source, with energy resolution of $9\\%$ ($\\sigma$). The toolkit GEANT4 was used to simulate the irradiation of the detector by an ${}^{241}Am-{}^{9}{Be}$ source, while SRIM was used to calculate the Ionization Quenching Factor (IQF). The GEANT4 simulated energy deposition spectrum in addition with the SRIM calculated quenching factor provide valuable insight to the experimental results. The performance of the SPC in low energy recoil detection makes the detector a good candidate for a wide range of applications, including Supernova or reactor neutrino detection and Dark Matter (WIMP) searc...

  20. GAMMA PROPORTIONAL COUNTER CONTAINING HIGH Z GAS AND LOW Z MODERATOR

    Science.gov (United States)

    Fox, R.

    1963-07-23

    A gamma radiation counter employing a gas proportional counter is described. The radiation counter comprises a cylindrical gas proportional counter which contains a high atomic number gas and is surrounded by a low atomic number gamma radiation moderator material. At least one slit is provided in the moderator to allow accident gamma radiation to enter the moderator in the most favorable manner for moderation, and also to allow low energy gamma radiation to enter the counter without the necessity of passing through the moderator. This radiation counter is capable of detecting and measuring gamma radiation in the energy range of 0.5-5 Mev. (AEC)

  1. Calibration and background measurements with a tissue equivalent proportional counter.

    Science.gov (United States)

    Autischer, M; Beck, P; Kindl, P; Latocha, M; Rollet, S

    2007-01-01

    A tissue-equivalent-proportional counter (TEPC) instrument has been used as the reference instrument for cosmic radiation measurement at flight altitudes by several institutes. For purposes of characterisation the response of the instrument has been investigated under different standard radiation conditions, in terms of radiation particle, energy and angle of incidence. Photon sources and photon beams of energies up to 6.6 MeV and neutron beams up to 200 MeV were used. To have a better understanding of the shielding influence of the instrument assembly, the angle dependence of response was analysed for several radiation conditions. Specific measurement conditions were simulated with the Monte Carlo transport code, FLUKA. The measured instrument response was compared with simulation results. It was demonstrated, that simulations were very helpful to understand the instrument's response. The TEPC instrument used by the Austrian Research Centre Seibersdorf (ARCS) research simulates the energy deposition in a unit density tissue volume of 2 microm diameter, of similar size to a cell nucleus. Pure propane at low pressure is used as measurement gas. To characterise the instrument at low dose rates background measurements were done 800 m below ground and at the ultra low level laboratory in Gran Sasso, 1380 m below ground. These results were compared with measurements on the Earth's surface at different altitudes on mountains up to 3480 m above sea level. The significant increase of the expected dose rate is well reproduced by the experiments at mountain altitudes. As a result of this study a full characterisation and a thorough understanding of the performance and reliability of the detector was achieved.

  2. Development of High Pressure Xe Scintillation Proportional Counter for Experiments in "Low-Background" Physics

    OpenAIRE

    Akimov, D.Yu.; Burenkov, A. A; Churakov, D. L.; Kuzichev, V. F.; Morgunov, V. L.; Smirnov, G. N.; Solovov, V.N.

    1997-01-01

    Characteristics of a scintillation proportional counter with WLS fiber optics readout is described. The possibility of detection of the proportional scintillation signal produced by the single electron of primary ionization is shown. The counter can be applied for the experiments in "low--background" physics which require a low energy threshold.

  3. Performance of microstrip proportional counters for x-ray astronomy on spectrum-roentgen-gamma

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Carl; BAHNSEN, A; Christensen, Finn Erland

    1991-01-01

    DSRI will provide a set of four imaging proportional counters for the Danish-Soviet X-ray telescopes XSPECT/SODART. The sensor principle is based on the novel micro-strip proportional counter (MSPC), where the strip electrodes are deposited by photolithography onto a rigid substrate. The MSPC off...

  4. Shielding concepts for low-background proportional counter arrays in surface laboratories

    CERN Document Server

    Aalseth, Craig E; Mace, Emily K; Orrell, John L; Seifert, Allen; Williams, Richard M

    2015-01-01

    Development of ultra low background gas proportional counters has made the contribution from naturally occurring radioactive isotopes -- primarily $\\alpha$ and $\\beta$ activity in the uranium and thorium decay chains -- inconsequential to instrumental sensitivity levels when measurements are performed in above ground surface laboratories. Simple lead shielding is enough to mitigate against gamma rays as gas proportional counters are already relatively insensitive to naturally occurring gamma radiation. The dominant background in these surface laboratory measurements using ultra low background gas proportional counters is due to cosmic ray generated muons, neutrons, and protons. Studies of measurements with ultra low background gas proportional counters in surface and underground laboratories as well as radiation transport Monte Carlo simulations suggest a preferred conceptual design to achieve the highest possible sensitivity from an array of low background gas proportional counters when operated in a surface...

  5. Shielding concepts for low-background proportional counter arrays in surface laboratories

    OpenAIRE

    Aalseth, Craig E.; Humble, Paul H.; Mace, Emily K.; Orrell, John L.; Seifert, Allen; Williams, Richard M.

    2015-01-01

    Development of ultra low background gas proportional counters has made the contribution from naturally occurring radioactive isotopes -- primarily $\\alpha$ and $\\beta$ activity in the uranium and thorium decay chains -- inconsequential to instrumental sensitivity levels when measurements are performed in above ground surface laboratories. Simple lead shielding is enough to mitigate against gamma rays as gas proportional counters are already relatively insensitive to naturally occurring gamma ...

  6. Underground low flux neutron background measurements in LSM using a large volume (1m3) spherical proportional counter

    Science.gov (United States)

    Savvidis, I.; Giomataris, I.; Bougamont, E.; Irastorza, I.; Aune, S.; Chapelier, M.; Charvin, P. H.; Colas, P.; Derre, J.; Ferrer, E.; Gerbier, G.; Gros, M.; Mangier, P.; Navick, X. F.; Salin, P.; Vergados, J. D.; Zampalo, M.

    2010-01-01

    A large volume (1m3) spherical proportional counter has been developed at CEA/Saclay, for low flux neutron measurements. The high voltage is applied to a small sphere 15mm in diameter, located in the center of the counter and the wall of the counter is grounded. Neutrons can be measured successfully, with high sensitivity, using 3He gas in the detector. The proton and tritium energy deposition in the drift gaseous volume, from the reaction 3He(n,p)3H, can provide the neutron spectra from thermal neutrons up to several MeV. The detector has been installed in the underground laboratory in Modane (LSM) to measure the neutron background. The sphere has been has been filled with gas mixture of Ar + 2% CH4 +3gr He-3, at 275 mbar. The thermal neutron peak is well separated from the cosmic ray and gamma background, permitting of neutron flux calculation. Other potential applications requiring large volume of about 10 m in radius are described in detail in reference

  7. Shielding concepts for low-background proportional counter arrays in surface laboratories.

    Science.gov (United States)

    Aalseth, C E; Humble, P H; Mace, E K; Orrell, J L; Seifert, A; Williams, R M

    2016-02-01

    Development of ultra low background gas proportional counters has made the contribution from naturally occurring radioactive isotopes - primarily α and β activity in the uranium and thorium decay chains - inconsequential to instrumental sensitivity levels when measurements are performed in above ground surface laboratories. Simple lead shielding is enough to mitigate against gamma rays as gas proportional counters are already relatively insensitive to naturally occurring gamma radiation. The dominant background in these surface laboratory measurements using ultra low background gas proportional counters is due to cosmic ray generated muons, neutrons, and protons. Studies of measurements with ultra low background gas proportional counters in surface and underground laboratories as well as radiation transport Monte Carlo simulations suggest a preferred conceptual design to achieve the highest possible sensitivity from an array of low background gas proportional counters when operated in a surface laboratory. The basis for a low background gas proportional counter array and the preferred shielding configuration is reported, especially in relation to measurements of radioactive gases having low energy decays such as (37)Ar.

  8. Shielding concepts for low-background proportional counter arrays in surface laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Aalseth, Craig E.; Humble, Paul H.; Mace, Emily K.; Orrell, John L.; Seifert, Allen; Williams, Richard M.

    2016-02-01

    Development of ultra low background gas proportional counters has made the contribution from naturally occurring radioactive isotopes – primarily and activity in the uranium and thorium decay chains – inconsequential to instrumental sensitivity levels when measurements are performed in above ground surface laboratories. Simple lead shielding is enough to mitigate against gamma rays as gas proportional counters are already relatively insensitive to naturally occurring gamma radiation. The dominant background in these surface laboratory measurements using ultra low background gas proportional counters is due to cosmic ray generated muons, neutrons, and protons. Studies of measurements with ultra low background gas proportional counters in surface and underground laboratories as well as radiation transport Monte Carlo simulations suggest a preferred conceptual design to achieve the highest possible sensitivity from an array of low background gas proportional counters when operated in a surface laboratory. The basis for a low background gas proportional counter array and the preferred shielding configuration is reported, especially in relation to measurements of radioactive gases having low energy decays such as 37Ar.

  9. Neutron spectroscopy with the Spherical Proportional Counter based on nitrogen gas

    Science.gov (United States)

    Bougamont, E.; Dastgheibi, A.; Derre, J.; Galan, J.; Gerbier, G.; Giomataris, I.; Gros, M.; Katsioulas, I.; Jourde, D.; Magnier, P.; Navick, X. F.; Papaevangelou, T.; Savvidis, I.; Tsiledakis, G.

    2017-03-01

    A novel large volume spherical proportional counter, recently developed, is used for neutron measurements. The pure N2 gas is studied for thermal and fast neutron detection, providing a new way for neutron spectroscopy. The neutrons are detected via the 14N (n , p)C14 and 14N (n , α)B11 reactions. The detector is tested for thermal and fast neutrons detection with 252Cf and 241Am -9Be neutron sources. The atmospheric neutrons are successfully measured from thermal up to several MeV, well separated from the cosmic ray background. A comparison of the spherical proportional counter with the current available neutron counters is also presented.

  10. Calibration methodology for proportional counters applied to yield measurements of a neutron burst

    Energy Technology Data Exchange (ETDEWEB)

    Tarifeño-Saldivia, Ariel, E-mail: atarifeno@cchen.cl, E-mail: atarisal@gmail.com; Pavez, Cristian; Soto, Leopoldo [Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Center for Research and Applications in Plasma Physics and Pulsed Power, P4, Santiago (Chile); Departamento de Ciencias Fisicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Republica 220, Santiago (Chile); Mayer, Roberto E. [Instituto Balseiro and Centro Atómico Bariloche, Comisión Nacional de Energía Atómica and Universidad Nacional de Cuyo, San Carlos de Bariloche R8402AGP (Argentina)

    2014-01-15

    This paper introduces a methodology for the yield measurement of a neutron burst using neutron proportional counters. This methodology is to be applied when single neutron events cannot be resolved in time by nuclear standard electronics, or when a continuous current cannot be measured at the output of the counter. The methodology is based on the calibration of the counter in pulse mode, and the use of a statistical model to estimate the number of detected events from the accumulated charge resulting from the detection of the burst of neutrons. The model is developed and presented in full detail. For the measurement of fast neutron yields generated from plasma focus experiments using a moderated proportional counter, the implementation of the methodology is herein discussed. An experimental verification of the accuracy of the methodology is presented. An improvement of more than one order of magnitude in the accuracy of the detection system is obtained by using this methodology with respect to previous calibration methods.

  11. Calibration methodology for proportional counters applied to yield measurements of a neutron burst.

    Science.gov (United States)

    Tarifeño-Saldivia, Ariel; Mayer, Roberto E; Pavez, Cristian; Soto, Leopoldo

    2014-01-01

    This paper introduces a methodology for the yield measurement of a neutron burst using neutron proportional counters. This methodology is to be applied when single neutron events cannot be resolved in time by nuclear standard electronics, or when a continuous current cannot be measured at the output of the counter. The methodology is based on the calibration of the counter in pulse mode, and the use of a statistical model to estimate the number of detected events from the accumulated charge resulting from the detection of the burst of neutrons. The model is developed and presented in full detail. For the measurement of fast neutron yields generated from plasma focus experiments using a moderated proportional counter, the implementation of the methodology is herein discussed. An experimental verification of the accuracy of the methodology is presented. An improvement of more than one order of magnitude in the accuracy of the detection system is obtained by using this methodology with respect to previous calibration methods.

  12. A novel method to measure low flux ambient thermal neutrons with 3He proportional counters

    Science.gov (United States)

    Zeng, Z. M.; Gong, H.; Yue, Q.; Li, J. M.

    2017-09-01

    A pulse shape discrimination method to discriminate neutron events from backgrounds based on the double-pulse effect of 3He proportional counters is proposed and detailed in this paper. We made an ambient thermal neutron measurement system composed of a commercial 3He proportional counter tube and the corresponding readout electronics. The background of the system has been measured and the minimum detectable amount of the 3He proportional counter tube will be reduced by an order of magnitude with this method. The system was applied to measure the ambient thermal neutron flux inside a large neutron shielding structure at a deep underground laboratory and the pulse shape discrimination method proves to be effective.

  13. X-ray Polarimetry with an Active-Matrix Pixel Proportional Counter

    Science.gov (United States)

    Black, J. K.; Deines-Jones, P.; Ready, S. E.; Street, R. A.

    2003-01-01

    We report the first results from an X-ray polarimeter with a micropattern gas proportional counter using an amorphous silicon active matrix readout. With 100% polarized X-rays at 4.5 keV, we obtain a modulation factor of 0.33+/- 0.03, confirming previous reports of the high polarization sensitivity of a finely segmented pixel proportional counter. The detector described here has a geometry suitable for the focal plane of an astronomical X-ray telescope. Amorphous silicon readout technology will enable additional extensions and improvements.

  14. Novel concept for neutron detection: proportional counter filled with 10B nanoparticle aerosol

    Science.gov (United States)

    Amaro, F. D.; Monteiro, C. M. B.; dos Santos, J. M. F.; Antognini, A.

    2017-01-01

    The high neutron detection efficiency, good gamma-ray discrimination and non-toxicity of 3He made of proportional counters filled with this gas the obvious choice for neutron detection, particularly in radiation portal monitors (RPM), used to control the illicit transport of nuclear material, of which neutron detectors are key components. 3He is very rare and during the last decade this gas has become increasingly difficult to acquire. With the exception of BF3, which is toxic, no other gas can be used for neutron detection in proportional counters. We present an alternative where the 3He atoms are replaced by nanoparticles made of another neutron sensitive material, 10B. The particles are dispersed in a gaseous volume, forming an aerosol with neutron sensitive properties. A proportional counter filled with such aerosol was exposed to a thermal neutron beam and the recorded response indicates that the neutrons have interacted with the particles in the aerosol. This original technique, which transforms a standard proportional gas mixture into a neutron sensitive aerosol, is a breakthrough in the field of radiation detection and has the potential to become an alternative to the use of 3He in proportional counters. PMID:28181520

  15. Novel concept for neutron detection: proportional counter filled with 10B nanoparticle aerosol

    Science.gov (United States)

    Amaro, F. D.; Monteiro, C. M. B.; Dos Santos, J. M. F.; Antognini, A.

    2017-02-01

    The high neutron detection efficiency, good gamma-ray discrimination and non-toxicity of 3He made of proportional counters filled with this gas the obvious choice for neutron detection, particularly in radiation portal monitors (RPM), used to control the illicit transport of nuclear material, of which neutron detectors are key components. 3He is very rare and during the last decade this gas has become increasingly difficult to acquire. With the exception of BF3, which is toxic, no other gas can be used for neutron detection in proportional counters. We present an alternative where the 3He atoms are replaced by nanoparticles made of another neutron sensitive material, 10B. The particles are dispersed in a gaseous volume, forming an aerosol with neutron sensitive properties. A proportional counter filled with such aerosol was exposed to a thermal neutron beam and the recorded response indicates that the neutrons have interacted with the particles in the aerosol. This original technique, which transforms a standard proportional gas mixture into a neutron sensitive aerosol, is a breakthrough in the field of radiation detection and has the potential to become an alternative to the use of 3He in proportional counters.

  16. Design of Charge Sensitive Pre-amplifier for Tissue-equivalent Proportional Counter

    Institute of Scientific and Technical Information of China (English)

    NI; Ning; ZHANG; Wei-hua; XIAO; Xue-fu; GAO; Fei; SONG; Ming-zhe; HOU; Jin-bing; WANG; Hong-yu

    2015-01-01

    Tissue equivalent proportional counter(TEPC)can differentiate the dose equivalent contributed from neutron and gamma ray in a mixture field and measure absorb dose and dose equivalent in the cell of human,and it is more suitable than other measurement methods to evaluate the radiation effect.It is providing a reference

  17. Response of low-noise miniaturized proportional counters in the keV region

    Science.gov (United States)

    Belli, P.; Cattadori, C.; Cerulli, R.; d'Angelo, S.; Ferrari, N.; Pandola, L.

    2005-04-01

    Miniaturized low-noise low-background proportional counters, used in the GNO experiment, have been calibrated in the keV energy region along their longitudinal axis by means of a new z- scanning system working deep underground at the Gran Sasso National Laboratory of the I.N.F.N.. Some of the obtained experimental features are reported.

  18. Optimization of the electric field distribution in a large volume tissue-equivalent proportional counter

    Energy Technology Data Exchange (ETDEWEB)

    Verma, P.K.; Waker, A.J. (Leeds Univ. (United Kingdom). Dept. of Medical Physics)

    1992-10-01

    Large volume tissue-equivalent proportional counters are of interest in radiation protection metrology, as the sensitivity in terms of counts per unit absorbed dose in these devices increases as the square of the counter diameter. Conventional solutions to the problem of maintaining a uniform electric field within a counter result in sensitive volume to total volume ratios which are unacceptably low when counter dimensions of the order of 15 cm diameter are considered and when overall compactness is an important design criterion. This work describes the design and optimization of an arrangement of field discs set at different potentials which enable sensitive volume to total volume ratios to approach unity. The method has been used to construct a 12.7 cm diameter right-cylindrical tissue-equivalent proportional counter in which the sensitive volume accounts for over 95% of the total device volume and the gas gain uniformity is maintained to within 3% along the entire length of the anode wire. (author).

  19. The Proportional Counter Source For The Low Energy Calibration Of The Sudbury Neutrino Observatory

    CERN Document Server

    Dalnoki-Veress, F J

    2003-01-01

    It is imperative that if a clean measurement is to be made of the Charged Current (CC) to Neutral Current (NC) ratio and the CC spectral distortion in the Sudbury Neutrino Observatory, the low energy background must be very well understood. For this reason a technique has been developed, so that each isotope of the background in the D2O can be measured. The technique relies on a proportional counter (PCS), which acts both as a detector as well as a source. If various sources such as 228Th are placed on the anode of the proportional counter, the beta-decay is tagged by the PCS and the Čerenkov radiation that is produced is detected by SNO. The method aims to make a background and distortion free measurement of the SNO detector response to a 228Th source. This thesis discusses the construction, development, testing, quality control and assurance, deployment and analysis of the PCS.

  20. Proportional counters aged anode wire recovering using an 80%CF4 + 20%CO2 gas mixture

    CERN Document Server

    Gavrilov, Gennady; Conti, Richard; Fetisov, Andrey; Maysuzenko, Dmitry; Shvecova, Natalia; Vakhtel, Victor

    2011-01-01

    A technique to recover a gas proportional counter having an aged anode wire using a glow discharge in an 80%CF4 + 20%CO2 gas mixture has been developed and tested. Studies of aging effects were carried out under sustained irradiation by an intense 90Sr -source of the straw proportional counters operated with a 60%Ar + 30%CO2 + 10%CF4 gas mixture. Special attention was paid to the aging mechanism of the anode wires. Our experience showed that using a given gas mixture the swelling of the anode wires is a typical mode of aging that leads to degradation of the gas gain. The proposed method of recovery provided a complete restoration of the gas gain and the signal amplitude in the damaged zone of the wire. SEM/XEM analysis confirmed successful cleaning WOx deposits from the wire surface. The application of this method to recover the aged gaseous detectors in real experimental conditions is discussed.

  1. Demand-type gas supply system for rocket borne thin-window proportional counters

    Science.gov (United States)

    Acton, L. W.; Caravalho, R.; Catura, R. C.; Joki, E. G.

    1977-01-01

    A simple closed loop control system has been developed to maintain the gas pressure in thin-window proportional counters during rocket flights. This system permits convenient external control of detector pressure and system flushing rate. The control system is activated at launch with the sealing of a reference volume at the existing system pressure. Inflight control to plus or minus 2 torr at a working pressure of 760 torr has been achieved on six rocket flights.

  2. Methodology for the use of proportional counters in pulsed fast neutron yield measurements

    OpenAIRE

    Tarifeño-Saldivia, Ariel; Mayer, Roberto E.; Pavez, Cristian; Soto, Leopoldo

    2011-01-01

    This paper introduces in full detail a methodology for the measurement of neutron yield and the necessary efficiency calibration, to be applied to the intensity measurement of neutron bursts where individual neutrons are not resolved in time, for any given moderated neutron proportional counter array. The method allows efficiency calibration employing the detection neutrons arising from an isotopic neutron source. Full statistical study of the procedure is descripted, taking into account cont...

  3. An array of low-background 3He proportional counters for the Sudbury Neutrino Observatory

    Science.gov (United States)

    Amsbaugh, J. F.; Anaya, J. M.; Banar, J.; Bowles, T. J.; Browne, M. C.; Bullard, T. V.; Burritt, T. H.; Cox-Mobrand, G. A.; Dai, X.; Deng, H.; Di Marco, M.; Doe, P. J.; Dragowsky, M. R.; Duba, C. A.; Duncan, F. A.; Earle, E. D.; Elliott, S. R.; Esch, E.-I.; Fergani, H.; Formaggio, J. A.; Fowler, M. M.; Franklin, J. E.; Geissbühler, P.; Germani, J. V.; Goldschmidt, A.; Guillian, E.; Hallin, A. L.; Harper, G.; Harvey, P. J.; Hazama, R.; Heeger, K. M.; Heise, J.; Hime, A.; Howe, M. A.; Huang, M.; Kormos, L. L.; Kraus, C.; Krauss, C. B.; Law, J.; Lawson, I. T.; Lesko, K. T.; Loach, J. C.; Majerus, S.; Manor, J.; McGee, S.; Miknaitis, K. K. S.; Miller, G. G.; Morissette, B.; Myers, A.; Oblath, N. S.; O'Keeffe, H. M.; Ollerhead, R. W.; Peeters, S. J. M.; Poon, A. W. P.; Prior, G.; Reitzner, S. D.; Rielage, K.; Robertson, R. G. H.; Skensved, P.; Smith, A. R.; Smith, M. W. E.; Steiger, T. D.; Stonehill, L. C.; Thornewell, P. M.; Tolich, N.; VanDevender, B. A.; Van Wechel, T. D.; Wall, B. L.; Wan Chan Tseung, H.; Wendland, J.; West, N.; Wilhelmy, J. B.; Wilkerson, J. F.; Wouters, J. M.

    2007-09-01

    An array of Neutral-Current Detectors (NCDs) has been built in order to make a unique measurement of the total active flux of solar neutrinos in the Sudbury Neutrino Observatory (SNO). Data in the third phase of the SNO experiment were collected between November 2004 and 2006, after the NCD array was added to improve the neutral-current sensitivity of the SNO detector. This array consisted of 36 strings of proportional counters filled with a mixture of 3He and CF 4 gas capable of detecting the neutrons liberated by the neutrino-deuteron neutral-current reaction in the D 2O, and four strings filled with a mixture of 4He and CF 4 gas for background measurements. The proportional counter diameter is 5 cm. The total deployed array length was 398 m. The SNO NCD array is the lowest-radioactivity large array of proportional counters ever produced. This article describes the design, construction, deployment, and characterization of the NCD array, discusses the electronics and data acquisition system, and considers event signatures and backgrounds.

  4. An array of low-background $^3$He proportional counters for the Sudbury Neutrino Observatory

    CERN Document Server

    Amsbaugh, J F; Banar, J C; Bowles, T J; Browne, M C; Bullard, T V; Burritt, T H; Cox-Mobrand, G A; Dai, X; Deng, H; Di Marco, M; Doe, P J; Dragowsky, M R; Duba, C A; Duncan, F A; Earle, E D; Elliott, S R; Esch, E -I; Fergani, H; Formaggio, J A; Fowler, M M; Franklin, J E; Geissbühler, P; Germani, J V; Goldschmidt, A; Guillian, E; Hallin, A L; Harper, G; Harvey, P J; Hazama, R; Heeger, K M; Heise, J; Hime, A; Howe, M A; Huang, M; Kormos, L L; Kraus, C V; Krauss, C B; Law, J; Lawson, I T; Lesko, K T; Loach, J C; Majerus, S; Manor, J; McGee, S; Miknaitis, K K S; Miller, G G; Morissette, B; Myers, A; Oblath, N S; O'Keeffe, H M; Ollerhead, R W; Peeters, S J M; Poon, A W P; Prior, G; Reitzner, S D; Rielage, K; Robertson, R G H; Skensved, P; Smith, A R; Smith, M W E; Steiger, T D; Stonehill, L C; Thornewell, P M; Tolich, N; VanDevender, B A; Van Wechel, T D; Wall, B L; Tseung, H Wan Chan; Wendland, J; West, N; Wilhelmy, J B; Wilkerson, J F; Wouters, J M

    2007-01-01

    An array of Neutral-Current Detectors (NCDs) has been built in order to make a unique measurement of the total active flux of solar neutrinos in the Sudbury Neutrino Observatory (SNO). Data in the third phase of the SNO experiment were collected between November 2004 and November 2006, after the NCD array was added to improve the neutral-current sensitivity of the SNO detector. This array consisted of 36 strings of proportional counters filled with a mixture of $^3$He and CF$_4$ gas capable of detecting the neutrons liberated by the neutrino-deuteron neutral current reaction in the D$_2$O, and four strings filled with a mixture of $^4$He and CF$_4$ gas for background measurements. The proportional counter diameter is 5 cm. The total deployed array length was 398 m. The SNO NCD array is the lowest-radioactivity large array of proportional counters ever produced. This article describes the design, construction, deployment, and characterization of the NCD array, discusses the electronics and data acquisition sys...

  5. A 10B-based neutron detector with stacked Multiwire Proportional Counters and macrostructured cathodes

    CERN Document Server

    Stefanescu, I; Birch, J; Defendi, I; Hall-Wilton, R; Hoglund, C; Hultman, L; Zee, M; Zeitelhack, K

    2013-01-01

    We present the results of the measurements of the detection efficiency for a 4.7 \\r{A} neutron beam incident upon a detector incorporating a stack of up to five MultiWire Proportional Counters (MWPC) with Boron-coated cathodes. The cathodes were made of Aluminum and had a surface exhibiting millimeter-deep V-shaped grooves of 45{\\deg}, upon which the thin Boron film was deposited by DC magnetron sputtering. The incident neutrons interacting with the converter layer deposited on the sidewalls of the grooves have a higher capture probability, owing to the larger effective absorption film thickness. This leads to a higher overall detection efficiency for the grooved cathode when compared to a cathode with a flat surface. Both the experimental results and the predictions of the GEANT4 model suggests that a 5-counter detector stack with coated grooved cathodes has the same efficiency as a 7-counter stack with flat cathodes. The reduction in the number of counters in the stack without altering the detection efficie...

  6. Characterisation of spherical recoil proton proportional counters used for neutron spectrometry

    CERN Document Server

    Pichenot, G; Gressier, V; Guldbakke, S; Itie, C; Klein, H; Knauf, K; Lebreton, L; Loeb, S; Pochon-Guerin, L; Schlegel, D J; Sosaat, W

    2002-01-01

    The Institute for Protection and Nuclear Safety (IPSN) standard neutron detector in the energy range 60-800 keV is a spherical proportional counter of HARWELL type SP2 nominally filled with 300 kPa hydrogen. It was characterised in the monoenergetic neutron fields of PTB at the energies of 144, 250 and 565 keV, where the neutron energy and fluence were determined with the PTB reference instruments. The neutron fields produced at the same energies with the accelerator facility of Bruyeres-le-Chatel were then investigated with the calibrated SP2 counter and various PTB instruments in order to determine the mean energy and the neutron fluence. The energy scale and a neutron fluence monitor were calibrated.

  7. A demonstration of one-atom detection. [Proportional counter with laser photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, G.S.; Nayfeh, M.H.; Young, J.P.

    1977-03-01

    Resonance ionization spectroscopy, a photoionization method in which all of a given quantum selected species are converted to ion pairs, has been used to develop a detector for a single atom. We have demonstrated the detection of one atom by using a pulsed dye laser to photoionize Cs to saturation and a proportional counter for the detection of single electrons. Some current applications, e.g., the slow transport and chemical reactions of atoms, are briefly discussed. Future applications may include the detection of rare events such as quarks, solar neutrinos, and superheavy elements. (AIP)

  8. Investigating the background of a 1-cm(3) quartz gas proportional counter.

    Science.gov (United States)

    Klouda, George A

    2008-01-01

    The background count rate of a 1-cm(3) quartz gas proportional counter (GPC) was investigated for measuring natural radioactivity levels of small samples. Using a new multiparameter digital counting system, spurious or afterpulses that contribute to background were identified by their pulse waveform and by a special event indicator defined by the time (low-background NaI(Tl) scintillation guard detector, the weighted mean and standard uncertainty anticoincidence counts per day (d(-1)) was 6.2+/-0.4d(-1).

  9. Simulations of electron avalanches in an ultra-low-background proportional counter

    Science.gov (United States)

    Robinson, John W.; Aalseth, Craig; Dion, Michael P.; Overman, Cory; Seifert, Allen; VanDevender, Brent

    2016-02-01

    New classes have been added to the simulation package Garfield++ to import the potential and electric field solutions generated by ANSYS ® MaxwellTM v.16. Using these tools we report results on the simulation of electron avalanches and induced signal waveforms in comparison to experimental data of the ultra-low-background gas proportional counters being developed at Pacific Northwest National Laboratory. Furthermore, an improved mesh search algorithm based on Delaunay triangulation was implemented and provided at least a three order of magnitude time savings when compared to the built-in point-location search class of Garfield++.

  10. Simulations of Electron Avalanches in an Ultra-Low-Background Proportional Counter

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, John W.; Aalseth, Craig E.; Dion, Michael P.; Overman, Cory T.; Seifert, Allen; VanDevender, Brent A.

    2016-02-21

    New classes have been added to the simulation package Garfield++ to import the potential and electric field solutions generated by ANSYS R MaxwellTM v.16. Using these tools we report results on the simulation of electron avalanches and induced signal waveforms in comparison to experimental data of the ultra-lowbackground gas proportional counters being developed at Pacific Northwest National Laboratory. Furthermore, an improved mesh search algorithm based on Delaunay triangulation was implemented and provided at least a three order of magnitude time savings when compared to the built-in point-location search class of Garfield++.

  11. Chemical abundances of cosmic rays greater than 4.5 GV measured with a large area proportional counter-scintillation counter stack

    Science.gov (United States)

    Lheureux, J.; Fan, C. Y.; Mainardi, R.; Gloeckler, G.

    1974-01-01

    A 6500 sq cm-ster cosmic-ray detector consisting of 12 gas counter trays sandwiched between two large-area circular scintillation counters was flown from Palestine, Texas in November 1972 to study the composition of primary particles greater than 1.5 GeV/nucleon in the charge range from 3 to 30. For each analyzed event, the particle trajectory was recorded, using four 20-wire proportional counter trays. Also recorded were the energy loss in each of the solid counters and the dE/dx losses in each of the 12 gas counters. The large dynamic range of the detector is established by operating six of the gas counters in the ionization mode. A description of the instrument and some preliminary results are given.

  12. A gaseous proportional counter built from a conventional aluminium beverage can

    CERN Document Server

    Winkler, Alexander; Hildén, Timo; Garcia, Francisco; Fedi, Giacomo; Devoto, Francesco; Brücken, Erik J

    2015-01-01

    The gaseous proportional counter is a device that can be used to detect ionizing radiation. These devices can be as simple as a cylindrical cathode and a very thin anode wire centered along its axis. By applying a high voltage, a strong electric field is generated close to the anode wire. Ion-pairs, generated by passing ionizing radiation, create avalanches once they drift into the strong electric field region near the anode. The electrical charges created by the avalanche generate an observable signal which is proportional to the energy loss of the incoming radiation. We discuss the construction of such a device. Our detector was built from an ordinary aluminium beverage can and uses a common electric wire strand as the anode. The construction of this detector offers students at universities or technically oriented high schools a detailed understanding of the design and operation of gaseous radiation detectors. The equipment required to complete the project should be available at most institutions.

  13. Annular shape silver lined proportional counter for on-line pulsed neutron yield measurement

    Science.gov (United States)

    Dighe, P. M.; Das, D.

    2015-04-01

    An annular shape silver lined proportional counter is developed to measure pulsed neutron radiation. The detector has 314 mm overall length and 235 mm overall diameter. The central cavity of 150 mm diameter and 200 mm length is used for placing the neutron source. Because of annular shape the detector covers >3π solid angle of the source. The detector has all welded construction. The detector is developed in two halves for easy mounting and demounting. Each half is an independent detector. Both the halves together give single neutron pulse calibration constant of 4.5×104 neutrons/shot count. The detector operates in proportional mode which gives enhanced working conditions in terms of dead time and operating range compared to Geiger Muller based neutron detectors.

  14. Calibration of an ultra-low-background proportional counter for measuring 37Ar

    Science.gov (United States)

    Seifert, A.; Aalseth, C. E.; Bonicalzi, R. M.; Bowyer, T. W.; Day, A. R.; Fuller, E. S.; Haas, D. A.; Hayes, J. C.; Hoppe, E. W.; Humble, P. H.; Keillor, M. E.; LaFerriere, B. D.; Mace, E. K.; McIntyre, J. I.; Merriman, J. H.; Miley, H. S.; Myers, A. W.; Orrell, J. L.; Overman, C. T.; Panisko, M. E.; Williams, R. M.

    2013-08-01

    An ultra-low-background proportional counter design has been developed at Pacific Northwest National Laboratory (PNNL) using clean materials, primarily electro-chemically-purified copper. This detector, along with an ultra-low-background counting system (ULBCS), was developed to complement a new shallow underground laboratory (30 meters water-equivalent) at PNNL. The ULBCS design includes passive neutron and gamma shielding, along with an active cosmic-veto system. This system provides a capability for making ultra-sensitive measurements to support applications like age-dating soil hydrocarbons with 14C/3H, age-dating of groundwater with 39Ar, and soil-gas assay for 37Ar to support On-Site Inspection (OSI). On-Site Inspection is a key component of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Measurements of radionuclides created by an underground nuclear explosion are valuable signatures of a Treaty violation. For OSI, the 35-day half-life of 37Ar, produced from neutron interactions with calcium in soil, provides both high specific activity and sufficient time for inspection before decay limits sensitivity. This work describes the calibration techniques and analysis methods developed to enable quantitative measurements of 37Ar samples over a broad range of proportional counter operating pressures. These efforts, along with parallel work in progress on gas chemistry separation, are expected to provide a significant new capability for 37Ar soil gas background studies.

  15. Performance of Large Area X-ray Proportional Counters in a Balloon Experiment

    CERN Document Server

    Roy, J; Dedhia, D K; Manchanda, R K; Shah, P B; Chitnis, V R; Gujar, V M; Parmar, J V; Pawar, D M; Kurhade, V B

    2016-01-01

    ASTROSAT is India's first satellite fully devoted to astronomical observations covering a wide spectral band from optical to hard X-rays by a complement of 4 co-aligned instruments and a Scanning Sky X-ray Monitor. One of the instruments is Large Area X-ray Proportional Counter with 3 identical detectors. In order to assess the performance of this instrument, a balloon experiment with two prototype Large Area X-ray Proportional Counters (LAXPC) was carried out on 2008 April 14. The design of these LAXPCs was similar to those on the ASTROSAT except that their field of view (FOV) was 3$^{\\circ}$ $\\times$ 3$^{\\circ}$ versus FOV of 1$^{\\circ}$ $\\times$ 1$^{\\circ}$ for the LAXPCs on the ASTROSAT. The LAXPCs are aimed at the timing and spectral studies of X-ray sources in 3-80 keV region. In the balloon experiment, the LAXPC, associated electronics and support systems were mounted on an oriented platform which could be pre-programmed to track any source in the sky. A brief description of the LAXPC design, laborator...

  16. Noise reduction for proportional counter signals in the GNO solar neutrino experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kiko, J. E-mail: kiko@mpi-hd.mpg.de

    2002-04-11

    The GALLEX solar neutrino experiment as well as the follow-up experiment GNO are low-level, low-statistics experiments with a mean production rate of 0.7 {sup 71}Ge atoms per day by neutrino capture on 30.3 t of natural gallium. This is a challenge with respect to the long time stability of the whole equipment, especially the stability of the electronic components which acquire the signals of the {sup 71}Ge decay events in proportional counters. Approximately, every month a sample of about ten {sup 71}Ge atoms (half-life 11.4 d) is typically measured in the GALLEX and GNO experiments for a period of half a year. The background is minimized by low-level techniques. In addition, {sup 71}Ge decays are distinguished from background events by pulse shape analyses. The background rejection efficiency is directly correlated with the signal to noise ratio of the recorded events. A method is described which increases the signal to noise ratio of the acquired ionization events and allows to distinguish between detector signals and noise picked up from the detector environment. This method can be applied not only for proportional counters but also for many other detectors.

  17. An array of low-background 3He proportional counters for theSudbury Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Amsbaugh, J.F.; Anaya, J.M.; Banar, J.; Bowles, T.J.; Browne,M.C.; Bullard, T.V.; Burritt, T.H.; Cox-Mobrand, G.A.; Dai, X.; H.Deng,X.; Di Marco, M.; Doe, P.J.; Dragowsky, M.R.; Duba, C.A.; Duncan, F.A.; Earle, E.D.; Elliott, S.R.; Esch, E.-I.; Fergani, H.; Formaggio, J.A.; Fowler, M.M.; Franklin, J.E.; Geissbuehler, P.; Germani, J.V.; Goldschmidt, A.; Guillian, E.; Hallin, A.L.; Harper, G.; Harvey, P.J.; Hazama, R.; Heeger, K.M.; Heise, J.; Hime, A.; Howe, M.A.; Huang, M.; Kormos, L.L.; Kraus, C.; Krauss, C.B.; Law, J.; Lawson, I.T.; Lesko,K.T.; Loach, J.C.; Majerus, S.; Manor, J.; McGee, S.; Miknaitis, K.K.S.; Miller, G.G.; Morissette, B.; Myers, A.; Oblath, N.S.; O' Kee, H.M.; Ollerhead, R.W.; Peeters, S.J.M.; Poon, A.W.P.; Prior, G.; Reitzner,S.D.; Rielage, K.; Robertson, R.G.H.; Skensved, P.; Smith, A.R.; Smith,M.W.E.; Steiger, T.D.; Stonehill,L.C.; Thornewell, P.M.; Tolich, N.; VanDevender, B.A.; VanWechel, T.D.; Wall, B.L.; Tseung, H.W.C.; Wendland,J.; West, N.; Wilhelmy, J.B.; Wilkerson, J.F.; Wouters, J.M.

    2007-02-01

    An array of Neutral-Current Detectors (NCDs) has been builtin order to make a unique measurement of the total active ux of solarneutrinos in the Sudbury Neutrino Observatory (SNO). Data in the thirdphase of the SNO experiment were collected between November 2004 andNovember 2006, after the NCD array was added to improve theneutral-current sensitivity of the SNO detector. This array consisted of36 strings of proportional counters lled with a mixture of 3He and CF4gas capable of detecting the neutrons liberated by the neutrino-deuteronneutral current reaction in the D2O, and four strings lled with a mixtureof 4He and CF4 gas for background measurements. The proportional counterdiameter is 5 cm. The total deployed array length was 398 m. The SNO NCDarray is the lowest-radioactivity large array of proportional countersever produced. This article describes the design, construction,deployment, and characterization of the NCD array, discusses theelectronics and data acquisition system, and considers event signaturesand backgrounds.

  18. BNCT dosimetry performed with a mini twin tissue-equivalent proportional counters (TEPC).

    Science.gov (United States)

    Moro, D; Colautti, P; Lollo, M; Esposito, J; Conte, V; De Nardo, L; Ferretti, A; Ceballos, C

    2009-07-01

    The BNCT radiation field is complex because different beam components are mixed, each one having different relative biological effectiveness (RBE). Microdosimetry with tissue-equivalent proportional counters (TEPC) has proven to be an ideal dosimetric technique for mixed radiation fields, because it is able both to measure the absorbed dose and to assess the radiation field relative biological effectiveness with good accuracy. An ideal detector for BNCT should contain two TEPCs, one detector loaded with, while the other one without (10)B in order to record all beam components with a unique measurement. Moreover, such a detector should be of tiny size in order to be able to measure in the intense BNCT radiation fields without significant pile-up effects. TEPCs have been shown to be pretty good dosimeters for mixed radiation fields. In this paper the first mini twin TEPC counter for BNCT is presented, as well as first measurement at the new HYTHOR thermal irradiation facility at TAPIRO nuclear reactor and comparison with related Monte Carlo calculations.

  19. The particle background of the Rosat PSPC. [Position Sensitive Proportional Counter

    Science.gov (United States)

    Snowden, S. L.; Plucinsky, P. P.; Briel, U.; Hasinger, G.; Pfeffermann, E.

    1992-01-01

    In order to permit quantitative studies of the diffuse cosmic X-ray background and of extended X-ray sources, the particle induced background of the Roentgen Satellite, Rosat, Position Sensitive Proportional Counter (PSPC) is parameterized. Data collected during 210,000 s of PSPC operation have been analyzed and the temporal, spectral, and spatial distributions investigated. About 77 percent of the residual events originate within the detector while the remainder enter through the counter window. During typical conditions, the count rate of the residual events is well correlated with the Master Veto (MV) count rate. The spectrum of these events is well described by a flat component plus a soft power law and an Al K-alpha line at 1.5 keV. Also during typical conditions, the ratio between the power law and flat components remains constant to +/- 4 while the relative Al K-alpha contribution increases with increasing MV count rate. The distribution of the counts over the field of view is uniform except for a slight radial dependence and shadowing caused by blockage of the externally produced component by the window support structure.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lane, S.M.; Dellis, J.H.; Bennett, C.K.; Campbell, E.M.

    1981-10-01

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

  1. Background simulation for the Spherical Proportional Counter and its use for the detection of optical photons

    Science.gov (United States)

    Bougamont, E.; Colas, P.; Dastgheibi-Fard, A.; Derre, J.; Giomataris, I.; Gerbier, G.; Gros, M.; Magnier, P.; Navick, X. F.; Salin, P.; Savvidis, I.; Tsiledakis, G.; Vergados, J. D.

    2013-10-01

    The recently developed Spherical Proportional Counter [1] allows to instrument large target masses with good energy resolution and sub-keV energy threshold. The moderate cost of this detector, its simplicity and robustness, makes this technology a promising approach for many domains of physics and applications, like dark matter detection and low energy neutrino searches. Detailed Monte Carlo simulations are essential to evaluate the background level expected at the sub-keV energy regime. The simulated background here, it refers to the contribution of the construction material of the detector and the effect of the environmental gamma radiation. This detector due to its spherical shape could be also served as an optical photon detector provided it is equipped with PMTs, for Double Beta decay and Dark Matter searches. All calculations shown here are obtained using the FLUKA Monte Carlo code.

  2. High-Sensitivity X-ray Polarimetry with Amorphous Silicon Active-Matrix Pixel Proportional Counters

    Science.gov (United States)

    Black, J. K.; Deines-Jones, P.; Jahoda, K.; Ready, S. E.; Street, R. A.

    2003-01-01

    Photoelectric X-ray polarimeters based on pixel micropattern gas detectors (MPGDs) offer order-of-magnitude improvement in sensitivity over more traditional techniques based on X-ray scattering. This new technique places some of the most interesting astronomical observations within reach of even a small, dedicated mission. The most sensitive instrument would be a photoelectric polarimeter at the focus of 2 a very large mirror, such as the planned XEUS. Our efforts are focused on a smaller pathfinder mission, which would achieve its greatest sensitivity with large-area, low-background, collimated polarimeters. We have recently demonstrated a MPGD polarimeter using amorphous silicon thin-film transistor (TFT) readout suitable for the focal plane of an X-ray telescope. All the technologies used in the demonstration polarimeter are scalable to the areas required for a high-sensitivity collimated polarimeter. Leywords: X-ray polarimetry, particle tracking, proportional counter, GEM, pixel readout

  3. Alpha-beta monitoring system based on pair of simultaneous Multi-Wire Proportional Counters

    Science.gov (United States)

    Wengrowicz, U.; Amidan, D.; Orion, I.

    2016-08-01

    A new approach for a simultaneous alpha-beta Multi-wire Proportional Counter (MWPC) is presented. The popular approach for alpha-beta monitoring systems consists of a large area MWPC using noble gas flow such as Argon Methane. This method of measurement is effective but requires large-scale and expensive maintenance due to the needs of gas flow control and periodic replacements. In this work, a pair of simultaneous MWPCs for alpha-beta measuring is presented. The developed detector consists of a sealed gas MWPC sensor for beta particles, behind a free air alpha sensor. This approach allows effective simultaneous detection and discrimination of both alpha and beta radiation without the maintenance cost noble gas flow required for unsealed detectors.

  4. A Model for the Secondary Scintillation Pulse Shape from a Gas Proportional Scintillation Counter

    CERN Document Server

    Kazkaz, Kareem

    2015-01-01

    Proportional scintillation counters (PSCs), both single- and dual-phase, can measure the scintillation (S1) and ionization (S2) channels from particle interactions within the detector volume. The signal obtained from these detectors depends first on the physics of the medium (the initial scintillation and ionization), and second how the physics of the detector manipulates the resulting photons and liberated electrons. In this paper we develop a model of the detector physics that incorporates event topology, detector geometry, electric field configuration, purity, optical properties of components, and wavelength shifters. We present an analytic form of the model, which allows for general study of detector design and operation, and a Monte Carlo model which enables a more detailed exploration of S2 events. This model may be used to study systematic effects in currents detectors such as energy and position reconstruction, pulse shape discrimination, event topology, dead time calculations, purity, and electric fi...

  5. Development of a spherical tissue equivalent proportional counter for neutron monitoring

    Institute of Scientific and Technical Information of China (English)

    姜志刚; 袁永刚; 王和义; 陈华

    2015-01-01

    A spherical tissue equivalent proportional counter (TEPC) for neutron monitoring has been developed. It was properly designed to produce a uniform electric field intensity around the anode wire. An internal 241Am alpha source was adopted for lineal energy calibration. The TEPC was characterized in terms of dose equivalent response in a standard 252Cf neutron field, and was tested with 2.45 MeV neutrons. Microdosimetric spec-tra, frequency mean lineal energy and dose-average mean lineal energy of 2.45 MeV neutrons were obtained and compared with FLUKA Monte Carlo simulation results. The measurement and simulation results agreed well. The mean quality factor and dose equivalent values evaluated from the 2.45 MeV neutron measurement were in good agreement with the recommended effective quality factor and ambient dose equivalent H∗(10), respectively. Preliminary results have proved the availability of the developed TEPC for neutron monitoring.

  6. Shielding experiment of heavy-ion produced neutrons using a tissue-equivalent proportional counter.

    Science.gov (United States)

    Nunomiya, T; Yonai, S; Takada, M; Fukumura, A; Nakamura, T

    2003-01-01

    A shielding experiment was performed at the HIMAC (Heavy Ion Medical Accelerator in Chiba), of National Institute of Radiological Sciences (NIRS), to measure neutron dose using a spherical TEPC (tissue-equivalent proportional counter) of 12.55 cm inner diameter. Neutrons are produced from a 5 cm thick stopping length Cu target bombarded by 400 MeV/nucleon C6+ ions and penetrate concrete or iron shields of various thicknesses at 0 degree to the beam direction. From this shielding experiment. y-distribution, mean lineal energy, absorbed dose, dose equivalent and mean-quality factor were obtained behind the shield as a function of shield thickness. The neutron dose attenuation lengths were also obtained as 126 g cm(-2) for concrete and 211 g cm(-2) for iron. The measured results were compared with the calculated results using the MARS Monte Carlo code.

  7. Methodology for the use of proportional counters in pulsed fast neutron yield measurements

    CERN Document Server

    Tarifeño-Saldivia, Ariel; Pavez, Cristian; Soto, Leopoldo

    2011-01-01

    This paper introduces in full detail a methodology for the measurement of neutron yield and the necessary efficiency calibration, to be applied to the intensity measurement of neutron bursts where individual neutrons are not resolved in time, for any given moderated neutron proportional counter array. The method allows efficiency calibration employing the detection neutrons arising from an isotopic neutron source. Full statistical study of the procedure is descripted, taking into account contributions arising from counting statistics, piling-up statistics of real detector pulse-height spectra and background fluctuations. The useful information is extracted from the net waveform area of the signal arising from the electric charge accumulated inside the detector tube. Improvement of detection limit is gained, therefore this detection system can be used in detection of low emission neutron pulsed sources with pulses of duration from nanoseconds to up. The application of the methodology to detection systems to be...

  8. Radiation effects on the proportional counter X-ray detectors on board the NEAR spacecraft

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, S.R. [NASA' s Goddard Space Flight Center, Laboratory for Extraterrestrial Physics, Greenbelt, MD 20771 (United States); Trombka, J.I. [NASA' s Goddard Space Flight Center, Laboratory for Extraterrestrial Physics, Greenbelt, MD 20771 (United States); Leidecker, H.W. [NASA' s Goddard Space Flight Center, Laboratory for Extraterrestrial Physics, Greenbelt, MD 20771 (United States); Clark, P.E. [The Catholic University of America, Washington, DC 20064 (United States); Starr, R. [The Catholic University of America, Washington, DC 20064 (United States); Goldsten, J.O. [Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723 (United States); Roth, D.R. [Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723 (United States)

    1999-02-11

    The X-ray proportional counters on board the Near Earth Asteroid Rendezvous (NEAR) spacecraft have exhibited a resolution degradation and recovery phenomenon several times during the long cruise phase of the mission. The resolution is checked periodically by commanding an {sup 55}Fe source into the window area. The degradation is seen as a low energy tailing of the 5.9 keV photopeak. Two events have occurred which provided good spectral data for better understanding the degradation phenomenon. In November 1997 a large solar particle event occurred that degraded the resolution and excited copper in the collimator. Eventually the detectors returned to normal. In January 1998 the spacecraft performed an Earth swingby gravity assist maneuver. The near Earth environment excited the magnesium and aluminum in the filter elements. The copper line was also produced. The NEAR spacecraft was launched in February 1996 and will rendezvous and orbit the asteroid 433 Eros in early 1999.

  9. Alpha–beta monitoring system based on pair of simultaneous Multi-Wire Proportional Counters

    Energy Technology Data Exchange (ETDEWEB)

    Wengrowicz, U.; Amidan, D. [Department of Nuclear Engineering, Ben Gurion University of the Negev, Beer-Sheva 84105 (Israel); NRC-Negev, P.O. Box 9001, Beer-Sheva 84190 (Israel); Orion, I. [Department of Nuclear Engineering, Ben Gurion University of the Negev, Beer-Sheva 84105 (Israel)

    2016-08-11

    A new approach for a simultaneous alpha–beta Multi-wire Proportional Counter (MWPC) is presented. The popular approach for alpha–beta monitoring systems consists of a large area MWPC using noble gas flow such as Argon Methane. This method of measurement is effective but requires large-scale and expensive maintenance due to the needs of gas flow control and periodic replacements. In this work, a pair of simultaneous MWPCs for alpha–beta measuring is presented. The developed detector consists of a sealed gas MWPC sensor for beta particles, behind a free air alpha sensor. This approach allows effective simultaneous detection and discrimination of both alpha and beta radiation without the maintenance cost noble gas flow required for unsealed detectors.

  10. Performance of large area x-ray proportional counters in a balloon experiment

    Science.gov (United States)

    Roy, J.; Agrawal, P. C.; Dedhia, D. K.; Manchanda, R. K.; Shah, P. B.; Chitnis, V. R.; Gujar, V. M.; Parmar, J. V.; Pawar, D. M.; Kurhade, V. B.

    2016-10-01

    ASTROSAT is India's first satellite fully devoted to astronomical observations covering a wide spectral band from optical to hard X-rays by a complement of 4 co-aligned instruments and a Scanning Sky X-ray Monitor. One of the instruments is Large Area X-ray Proportional Counter with 3 identical detectors. In order to assess the performance of this instrument, a balloon experiment with two prototype Large Area X-ray Proportional Counters (LAXPC) was carried out on 2008 April 14. The design of these LAXPCs was similar to those on the ASTROSAT except that their field of view (FOV) was 3 ∘ × 3 ∘ versus FOV of 1 ∘ × 1 ∘ for the LAXPCs on the ASTROSAT. The LAXPCs are aimed at the timing and spectral studies of X-ray sources in 3-80 keV region. In the balloon experiment, the LAXPC, associated electronics and support systems were mounted on an oriented platform which could be pre-programmed to track any source in the sky. A brief description of the LAXPC design, laboratory tests, calibration and the detector characteristics is presented here. The details of the experiment and background counting rates of the 2 LAXPCs at the float altitude of about 41 km are presented in different energy bands. The bright black hole X-ray binary Cygnus X-1 (Cyg X-1) was observed in the experiment for ˜ 3 hours. Details of Cyg X-1 observations, count rates measured from it in different energy intervals and the intensity variations of Cyg X-1 detected during the observations are presented and briefly discussed.

  11. Imaging micro-well proportional counters fabricated with masked UV laser ablation

    CERN Document Server

    Deines-Jones, P; Crawford, H; Hunter, S D

    2002-01-01

    The micro-well detector is a gas-proportional counter similar to the CAT (Bartol et al., J. Phys. III 6 (1996) 337) and WELL detectors (Bellazzini et al., Nucl. Instr. and Meth. A 423 (1999) 125). The micro-well is a cylindrical hole formed in the polymer substrate of commercially fabricated copper-clad flexible printed circuit board by UV laser ablation. The micro-wells are drilled at GSFC's UV laser-ablation facility. The cathode is a metal annulus that surrounds the opening of the well. The anode is a metal pad that fills the bottom of the well. Advantages of this topology include intrinsic two-dimensional sensing, thick robust electrodes, and large localized image charge on the cathodes. We have fabricated 5 cmx5 cm micro-well detectors with segmented anodes (1-d) and with both anodes and cathodes segmented (2-d), and have demonstrated: - stable, proportional operation at gas gains in excess of 30,000 in Ar- and Xe-based gases; - FWHM energy resolution of 20% at 6 keV in P-10; - preliminary 1-d spatial re...

  12. Characterization of a mid-sized Li foil multi-wire proportional counter neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A., E-mail: knelson1@ksu.edu [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Kusner, Michael R. [Saint-Gobain Crystals, Hiram, OH 44234 (United States); Montag, Benjamin W. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Mayhugh, Michael R. [Saint-Gobain Crystals, Hiram, OH 44234 (United States); Schmidt, Aaron J.; Wayant, Clayton D.; Shultis, J. Kenneth; Ugorowski, Philip B.; McGregor, Douglas S. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)

    2014-10-21

    A 550 cm{sup 2} thermal neutron detector was constructed with five parallel sheets of 75 µm thick {sup 6}Li foil (95% enrichment) spaced 1.63 cm apart. Anode wire banks containing a plurality of anode wires were strung on both sides of each foil, six banks in total. The chamber was backfilled with P-10 proportional gas and over-pressured to 1.1, 1.5, 2.0, and 2.8 atm (111, 151, 202, and 284 kPa). The design was tailored to allow the products from the {sup 6}Li(n,t){sup 4}He reaction to escape both sides of the Li foil simultaneously, thereby, allowing for concurrent measurement in the proportional gas. The measured intrinsic thermal neutron detection efficiency of the detector with normal incident thermal neutrons to the foil sheets was 53.8±0.20%. When the detector was angled (55° from normal) such that a 0.5 cm diameter thermal neutron beam intersected all of the foil layers, the intrinsic thermal neutron detection efficiency increased to 58.6±0.21%. A {sup 252}Cf neutron source positioned at a distance of 2.0 m yielded an absolute neutron detection efficiency of 0.73 cps ng{sup −1}. The gamma-ray rejection ratio (GRR) was 7.67×10{sup –9} as measured from a {sup 60}Co source for an exposure rate of 40 mR hr{sup −1}. Theoretical pulse-height spectra obtained with MCNP6 agreed well with experimental data and allowed pulse-height spectra and discriminator settings to be energy-calibrated. These results demonstrate the potential for the Li foil multi-wire proportional counter (MWPC) as a viable {sup 3}He neutron detector replacement.

  13. Radiation quality evaluation in heavy water field using tissue equivalent-proportional counter with wall containing boron

    Energy Technology Data Exchange (ETDEWEB)

    Onizuka, Y. [Kyushu Univ., Faculty of Medicine, Fukuoka (Japan); Endo, S.; Ishikawa, M. [Hiroshima Univ., Research Inst. for Radiation Biology and Medicine, Hiroshima (JP)] [and others

    2003-01-01

    A heavy water installation at the Kyoto University Reactor (KUR) is used for the boron neutron capture therapy. The contributions of boron neutron capture reaction to the dose are required for the evaluation of the boron neutron capture therapy in relation to the biological effectiveness. The radiation therapy fields are measured by a technique of micro-dosimetry. Three types of tissue equivalent-proportional counter are used for measurement of the radiation therapy fields; a LET counter with wall containing boron for thermal neutrons, a LET counter with wall containing no boron for epithermal neutrons, and a helical wire proportional counter with carbon wall for gamma rays. Irradiations of the counters are carried out in the neutron capture therapy fields with two modes, a thermal neutron mode and an epithermal neutron mode. An acrylic plate is used for human body phantom. Each energy spectrum in the counters is measured at depth 6.7 mm in the phantom by multi-channel analyzer. The energy spectra in three types of the counters show that most of neutron energy transfers to the effects of {sup 4}He(1.49 MeV) and {sup 7}Li(0.85 MeV) following to thermal neutron capture reactions of {sup 10}B in the wall. (M. Suetake)

  14. Design of a hybrid gas proportional counter with CdTe guard counters for sup 1 sup 4 C dating system

    CERN Document Server

    Zhang, L; Hinamoto, N; Nakazawa, M; Yoshida, K

    2002-01-01

    Nowadays uniform, low-cost and large-size compound semiconductor detectors are available up to several square centimeters. We are trying to combine this technology with conventional gas detectors to upgrade an anticoincidence type proportional counter, Oeschger-type thin wall counter of 2.2 l, used for a sup 1 sup 4 C dating facility at the University of Tokyo. In order to increase the ratio of the signal to the background for smaller quantity of samples less than 1 g, an effective approach is to minimize the detector volume at higher gas pressure. However, the anticoincidence function suffers from such a small volume. Therefore we designed a new active wall gas counter of 0.13 l counting volume using CdTe compound semiconductor detectors as the wall of the gas proportional counter to perform anticoincidence. Simulation study showed that at noise thresholds less than 70 keV, the wall counters can reject above 99.8% of events arising from outer gamma rays. Measured noise levels of CdTe detectors were smaller t...

  15. Replacement of monochromator and proportional gas counter by mercuric iodide detector in X-ray powder diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Nissenbaum, J.; Levi, A.; Burger, A.; Schieber, M. (Hebrew Univ., Jerusalem (Israel). School of Applied Science and Technology)

    1983-02-01

    Low resolution and therefore low-cost mercuric iodide detectors have successfully been applied to replace the combination of a graphite monochromator and a proportional gas radiation counter used in X-ray diffractometers. The mercuric iodide detector requires a lower DC bias of only 200 V rather than the 1500 V bias needed for the proportional gas counter. The much better stopping power of HgI/sub 2/ allows higher counting efficiency and therefore a better signal-to-noise ratio. Results are shown for X-ray powder diffractions of polycrystalline cubic silicon and tetragonal HgI/sub 2/.

  16. Absolute determination of radiation bursts and of proportional counters space charge effect through the influence method

    Science.gov (United States)

    Rios, I. J.; Mayer, R. E.

    2016-11-01

    When proportional counters are employed in charge integration mode to determine the magnitude of a radiation pulse, so intense that individual detection events take place in a time too short to produce individual output pulses, mostly in pulsed neutron sources, the strong build-up of positive space charge reduces the electric multiplication factor of the proportional detector. Under such conditions the ensuing measurement underestimates the amount of radiation that interacted with the detector. If the geometric characteristics, the filling gas pressure and the voltage applied to that detector are known, it becomes possible to apply an analytical correction method to the measurement. In this article we present a method that allows to determine the absolute value of the detected radiation burst without the need to know the characteristics of the employed detectors. It is necessary to employ more than one detector, taking advantage of the Influence Method. The "Influence Method" is conceived for the absolute determination of a nuclear particle flux in the absence of known detector efficiency and without the need to register coincidences of any kind. This method exploits the influence of the presence of one detector in the count rate of another detector, when they are placed one behind the other and define statistical estimators for the absolute number of incident particles and for the efficiency (Rios and Mayer, 2015 [1,2]). Its practical implementation in the measurement of a moderated neutron flux arising from an isotopic neutron source was exemplified in (Rios and Mayer, 2016 [3]) and the extension for multiple detectors in (Rios and Mayer 2016 [4]).

  17. HILT - A heavy ion large area proportional counter telescope for solar and anomalous cosmic rays

    Science.gov (United States)

    Klecker, Berndt; Hovestadt, Dietrich; Scholer, M.; Arbinger, H.; Ertl, M.; Kaestle, H.; Kuenneth, E.; Laeverenz, P.; Seidenschwang, E.; Blake, J. B.

    1993-01-01

    The HILT sensor has been designed to measure heavy ion elemental abundances, energy spectra, and direction of incidence in the mass range from He to Fe and in the energy range 4 to 250 MeV/nucleon. With its large geometric factor of 60 sq cm sr the sensor is optimized to provide compositional and spectral measurements for low intensity cosmic rays (i.e. for small solar energetic particle events and for the anomalous component of cosmic rays). The instrument combines a large area ion drift chamber-proportional counter system with two arrays of 16 Li-drift solid state detectors and 16 CsI crystals. The multi dE/dx-E technique provides a low background mass and energy determination. The sensor also measures particle direction. Combining these measurements with the information on the spacecraft position and attitude in the low-altitude polar orbit, it will be possible to infer the ionic charge of the ions from the local cutoff of the Earth's magnetic field. The ionic charge in this energy range is of particular interest because it provides unique clues to the origin of these particles and has not been investigated systematically so far. Together with the other instruments on board SAMPEX (LEICA, MAST, and PET), a comprehensive measurement of the entire solar and anomalous particle population will be achieved.

  18. Characterization of a Spherical Proportional Counter in argon-based mixtures

    CERN Document Server

    Iguaz, F J; Castel, J F; Irastorza, I G

    2014-01-01

    The Spherical Proportional Counter is a novel type of radiation detector, with a low energy threshold (typically below 100 eV) and good energy resolution. This detector is being developed by the network NEWS, which includes several applications. We can name between many others Dark Matter searches, low level radon and neutron counting or low energy neutrino detection from supernovas or nuclear reactors via neutrino-nucleus elastic scattering. In this context, this works will present the characterization of a spherical detector of 1 meter diameter using two argon-based mixtures (with methane and isobutane) and for gas pressures between 50 and 1250 mbar. In each case, the energy resolution shows its best value in a wide range of gains, limited by the ballistic effect at low gains and by ion-backflow at high gains. Moreover, the best energy resolution shows a degradation with pressure. These effects will be discussed in terms of gas avalanche properties. Finally, the effect of an electrical field corrector in th...

  19. Advances in the RXTE Proportional Counter Array Calibration: Nearing the Statistical Limit

    CERN Document Server

    Shaposhnikov, Nikolai; Markwardt, Craig; Swank, Jean; Strohmayer, Tod

    2012-01-01

    During its 16 years of service the Rossi X-ray Timing Explorer (RXTE) mission has provided an extensive archive of data, which will serve as a primary source of high cadence observations of variable X-ray sources for fast timing studies. It is, therefore, very important to have the most reliable calibration of RXTE instruments. The Proportional Counter Array (PCA) is the primary instrument on-board RXTE which provides data in 3-50 keV energy range with sub-millisecond time resolution in up to 256 energy channels. In 2009 the RXTE team revised the response residual minimization method used to derive the parameters of the PCA physical model. The procedure is based on the residual minimization between the model spectrum for Crab nebula emission and a calibration data set consisting of a number of spectra from the Crab and the on-board Am241 calibration source, uniformly covering the whole RXTE mission operation period. The new method led to a much more effective model convergence and allowed for better understan...

  20. Helium-filled proportional counter and its operation mechanism at low temperatures

    CERN Document Server

    Isozumi, Y; Kishimoto, S

    2002-01-01

    The operation mechanism of helium-filled proportional counter (HFPC) at about 4.2 K is explained. Unstable behavior of HFPC is caused by releasing secondary-electron from the cathode by four kinds of active particles such as He sub n sup + , non-resonance photon from excited helium atom, non-resonance photon from He sub 2 sup * (A sup 1 Su sup +) and He sub 2 sup m (a sup 3 Su sup +). On experiments of HFPC behavior at low temperature, the following facts were observed; 1) main charge formation process in the electron avalanche is direct ionization by electron without Hornbeck-Molnar process. Accordingly, the gas amplification factor becomes small at low temperature. 2) Stable helium cation is He sub 2 sup + at room temperature, but cluster at low temperature. Large after-pulse is observed in output signal depends on cluster ion. The probability of secondary-electron emission decreased. The gas gain increased with increasing anode voltage. 3) By decreasing reaction rate of atom and molecule collision at low t...

  1. Calibration of tissue-equivalent proportional counters with the PTB neutron reference fields

    Energy Technology Data Exchange (ETDEWEB)

    Rahm, Johannes [Institut fuer medizinische Physik und Strahlenschutz, Fachhochschule Giessen-Friedberg, Wiesenstrasse 14, 35390 Giessen (Germany); Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany); Breckow, Joachim [Institut fuer medizinische Physik und Strahlenschutz, Fachhochschule Giessen-Friedberg, Wiesenstrasse 14, 35390 Giessen (Germany); Burda, Oleksiy; Klages, Thorsten; Langner, Frank; Wissmann, Frank [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany)

    2011-07-01

    Dose determination in microdosimetric dimensions is essential for radiation protection, as well as for radiation biology and radiation therapy. Especially in mixed radiation fields with a large neutron component a tissue-equivalent proportional counter (TEPC) is an excellent instrument for dose measurement. The TEPC response to neutrons was measured using the PTB neutron reference fields at energies of 0.606 MeV, 1.2 MeV, 8 MeV and 19 MeV. To determine dose and dose-equivalent microdosimetric spectra, a system with three gain stages was set up to cover a linear energy range from 10{sup -2} keV/{mu}m up to 10{sup 4} keV/{mu}m. Two spherical TEPCs with a diameter of 2.24 were filled with a propane based tissue-equivalent gas mixture to simulate a tissue diameter of 2 {mu}m and 4 {mu}m, respectively. The aim of this work is to investigate the influence of different gas fillings and to obtain the response function of the TEPC with regard to monoenergetic neutron reference fields.

  2. A suspended boron foil multi-wire proportional counter neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A.; Edwards, Nathaniel S.; Hinson, Niklas J.; Wayant, Clayton D.; McGregor, Douglas S.

    2014-12-11

    Three natural boron foils, approximately 1.0 cm in diameter and 1.0 µm thick, were obtained from The Lebow Company and suspended in a multi-wire proportional counter. Suspending the B foils allowed the alpha particle and Li ion reaction products to escape simultaneously, one on each side of the foil, and be measured concurrently in the gas volume. The thermal neutron response pulse-height spectrum was obtained and two obvious peaks appear from the 94% and 6% branches of the {sup 10}B(n,α){sup 7}Li neutron reaction. Scanning electron microscope images were collected to obtain the exact B foil thicknesses and MCNP6 simulations were completed for those same B thicknesses. Pulse-height spectra obtained from the simulations were compared to experimental data and matched well. The theoretical intrinsic thermal–neutron detection efficiency for enriched {sup 10}B foils was calculated and is presented. Additionally, the intrinsic thermal neutron detection efficiency of the three natural B foils was calculated to be 3.2±0.2%.

  3. Simulation and experimental results for the detection of conversion electrons with gas proportional scintillation counters

    CERN Document Server

    Rachinhas, P J B M; Lopes, J A M; Dias, T; Morgado, R E; Santos, J M; Stauffer, A D; Conde, C A N

    2000-01-01

    The application of gas proportional scintillation counters (GPSC) to the detection and identification of conversion electrons in the medium energy range is investigated. Experimental and Monte Carlo results are presented for the response of a xenon GPSC, filled at atmospheric pressure, to the decay of a sup 1 sup 0 sup 9 Cd source. This source emits 88.0 keV gamma-rays, e sub L =84.6 keV and e sub K =62.5 keV conversion electrons, as well as fluorescence X-rays and Auger electrons. Good agreement is found between the measured and the calculated energy spectra. The response to higher-energy electrons is investigated by Monte Carlo simulation, by considering a hypothetical GPSC filled with xenon at 10 atm and doped with the sup 1 sup 3 sup 3 sup m Xe metastable isotope. The calculated energy spectra for the absorption of the sup 1 sup 3 sup 3 sup m Xe 233.2 keV gamma-rays, e sub K =198.6 keV and e sub L =228.4 keV conversion electrons, as well as fluorescence X-rays and Auger electrons, are presented and discus...

  4. Noise reduction for proportional counter signals in the GNO solar neutrino experiment

    CERN Document Server

    Kiko, J

    2002-01-01

    The GALLEX solar neutrino experiment as well as the follow-up experiment GNO are low-level, low-statistics experiments with a mean production rate of 0.7 sup 7 sup 1 Ge atoms per day by neutrino capture on 30.3 t of natural gallium. This is a challenge with respect to the long time stability of the whole equipment, especially the stability of the electronic components which acquire the signals of the sup 7 sup 1 Ge decay events in proportional counters. Approximately, every month a sample of about ten sup 7 sup 1 Ge atoms (half-life 11.4 d) is typically measured in the GALLEX and GNO experiments for a period of half a year. The background is minimized by low-level techniques. In addition, sup 7 sup 1 Ge decays are distinguished from background events by pulse shape analyses. The background rejection efficiency is directly correlated with the signal to noise ratio of the recorded events. A method is described which increases the signal to noise ratio of the acquired ionization events and allows to distinguish ...

  5. Primary and secondary scintillation measurements in a Xenon Gas Proportional Scintillation Counter

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, L M P; Freitas, E D C; Monteiro, C M B; Santos, J M F dos [Instrumentation Centre, Physics Department, University of Coimbra, P-3004-516 Coimbra (Portugal); Ball, M; Gomez-Cadenas, J J; Yahlali, N [Instituto de Fisica Corpuscular, E-46071, Valencia (Spain); Nygren, D, E-mail: pancho@gian.fis.uc.p [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2010-09-15

    NEXT is a new experiment to search for neutrinoless double beta decay using a 100 kg radio-pure high-pressure gaseous xenon TPC. The detector requires excellent energy resolution, which can be achieved in a Xe TPC with electroluminescence readout. Hamamatsu R8520-06SEL photomultipliers are good candidates for the scintillation readout. The performance of this photomultiplier, used as VUV photosensor in a gas proportional scintillation counter, was investigated. Initial results for the detection of primary and secondary scintillation produced as a result of the interaction of 5.9 keV X-rays in gaseous xenon, at room temperature and at pressures up to 3 bar, are presented. An energy resolution of 8.0% was obtained for secondary scintillation produced by 5.9 keV X-rays. No significant variation of the primary scintillation was observed for different pressures (1, 2 and 3 bar) and for electric fields up to 0.8 V cm{sup -1} torr{sup -1} in the drift region, demonstrating negligible recombination luminescence. A primary scintillation yield of 81 {+-} 7 photons was obtained for 5.9 keV X-rays, corresponding to a mean energy of 72 {+-} 6 eV to produce a primary scintillation photon in xenon.

  6. Primary and secondary scintillation measurements in a xenon Gas Proportional Scintillation Counter

    CERN Document Server

    Fernandes, L M P; Ball, M; Gómez-Cadenas, J J; Monteiro, C M B; Yahlali, N; Nygren, D; Santos, J M F dos

    2010-01-01

    NEXT is a new experiment to search for neutrinoless double beta decay using a 100 kg radio-pure high-pressure gaseous xenon TPC. The detector requires excellent energy resolution, which can be achieved in a Xe TPC with electroluminescence readout. Hamamatsu R8520-06SEL photomultipliers are good candidates for the scintillation readout. The performance of this photomultiplier, used as VUV photosensor in a gas proportional scintillation counter, was investigated. Initial results for the detection of primary and secondary scintillation produced as a result of the interaction of 5.9 keV X-rays in gaseous xenon, at room temperature and at pressures up to 3 bar, are presented. An energy resolution of 8.0% was obtained for secondary scintillation produced by 5.9 keV X-rays. No significant variation of the primary scintillation was observed for different pressures (1, 2 and 3 bar) and for electric fields up to 0.8 V cm-1 torr-1 in the drift region, demonstrating negligible recombination luminescence. A primary scinti...

  7. Compact Tissue-equivalent Proportional Counter for Deep Space Human Missions.

    Science.gov (United States)

    Straume, T; Braby, L A; Borak, T B; Lusby, T; Warner, D W; Perez-Nunez, D

    2015-10-01

    Effects on human health from the complex radiation environment in deep space have not been measured and can only be simulated here on Earth using experimental systems and beams of radiations produced by accelerators, usually one beam at a time. This makes it particularly important to develop instruments that can be used on deep-space missions to measure quantities that are known to be relatable to the biological effectiveness of space radiation. Tissue-equivalent proportional counters (TEPCs) are such instruments. Unfortunately, present TEPCs are too large and power intensive to be used beyond low Earth orbit (LEO). Here, the authors describe a prototype of a compact TEPC designed for deep space applications with the capability to detect both ambient galactic cosmic rays and intense solar particle event radiation. The device employs an approach that permits real-time determination of yD (and thus quality factor) using a single detector. This was accomplished by assigning sequential sampling intervals as detectors “1” and “2” and requiring the intervals to be brief compared to the change in dose rate. Tests with g rays show that the prototype instrument maintains linear response over the wide dose-rate range expected in space with an accuracy of better than 5% for dose rates above 3 mGy h(-1). Measurements of yD for 200 MeV n(-1) carbon ions were better than 10%. Limited tests with fission spectrum neutrons show absorbed dose-rate accuracy better than 15%.

  8. SINGLE ANODE TRIPLE GEM TISSUE EQUIVALENT PROPORTIONAL COUNTER AS THE BASIS FOR A PERSONAL NEUTRON DOSIMETER.

    Science.gov (United States)

    Seydaliev, M; Dubeau, J; Ali, F

    2017-04-28

    This paper reports on a tissue-equivalent proportional counter (TEPC) based on a triple gas electron multiplier structure, with a single pad readout, as a basis for a personal neutron dosimeter. Its dosimetric response was studied using the 252Cf neutron source at the Health Physics Generator Facility of the Canadian Nuclear Laboratories. Measured lineal energy spectra were found to be in agreement with numerical simulations performed with Monte Carlo N-Particle eXtended (MCNPX). Both simulations and measurements showed that the mean pathlength of secondary charged particles in the TEPC gas was best represented by the thickness of the drift region of the device. It was determined that the Cauchy Theorem, used to calculate the mean chord length in spherical and cylindrical TEPCs, overestimated the simulated mean chord length by nearly a factor of two. Important operational characteristics of the device were investigated, including gas gain, sensitivity and dosimetric response, as functions of tissue-equivalent gas pressure. This work demonstrates that the proposed design can serve as the basis for a personal neutron dosimeter device, which would satisfy the angular dosimetric response criteria of the personal dosimeter standard IEC61526. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Absolute measurement of the activity of sup 2 sup 2 sup 2 Rn using a proportional counter

    CERN Document Server

    Busch, I; Keyser, U

    2002-01-01

    A measuring set-up comprising a proportional counter of calculable sup 2 sup 2 sup 2 Rn efficiency and quantifiable active volume (delta sub V <0.1%) is described. On account of the special design of the end caps, the counter is suitable for absolute activity measurements on gaseous radiation sources. The sup 2 sup 2 sup 2 Rn efficiency is determined by computer simulation of the measured alpha-spectra. The procedures necessary for absolute measurements by means of the counter are described, and the suitability of the counter for absolute measurements of the sup 2 sup 2 sup 2 Rn activity is proved by experiments. Thus, a new method for the realization of the unit of activity of sup 2 sup 2 sup 2 Rn is obtained, which is independent of the unit of activity of sup 2 sup 2 sup 6 Ra.

  10. Initial characterization of unequal-length, low-background proportional counters for absolute gas-counting applications

    Science.gov (United States)

    Mace, E. K.; Aalseth, C. E.; Bonicalzi, R.; Day, A. R.; Fuller, E. S.; Hayes, J. C.; Hoppe, E. W.; LaFerriere, B. D.; Merriman, J. H.; Overman, C. T.; Seifert, A.; Williams, R. M.

    2013-08-01

    Characterization of two sets of custom unequal length proportional counters is underway at Pacific Northwest National Laboratory (PNNL). These detectors will be used in measurements to determine the absolute activity concentration of gaseous radionuclides (e.g., 37Ar). A set of three detectors has been fabricated based on previous PNNL ultra-low-background proportional counter designs and now operate in PNNL's shallow underground counting laboratory. A second set of four counters has also been fabricated using clean assembly of Oxygen-Free High-Conductivity copper components for use in a shielded above-ground counting laboratory. Characterization of both sets of detectors is underway with measurements of background rates, gas gain, and energy resolution. These results will be presented along with a shielding study for the above-ground cave.

  11. Methods of calculus for neutron spectrometry in proportional counters; Metodos de calculo para espectrometria de neutrones en contadores proporcionales

    Energy Technology Data Exchange (ETDEWEB)

    Butragueno, J. L.; Blazquez, J. B.; Barrado, J. M.

    1976-07-01

    Response functions for cylindrical proportional counters with hydrogenated gases have been determined, taking in account only wall effect, by means of two independent calculus methods. One of them is a Monte Carlo application and the other one analytica at all. Results of both methods have been compared. (Author)

  12. Tissue Equivalent Proportional Counter Microdosimetry Measurements Utilized Aboard Aircraft and in Accelerator Based Space Radiation Shielding Studies

    Science.gov (United States)

    Gersey, Brad B.; Wilkins, Richard T.

    2010-01-01

    This slide presentation reviews the Tissue Equivalent Proportional Counter (TEPC), a description of the spatially restricted LET Model, high energy proton TEPC and the results of modeling, the study of shielding and the results from the flight exposures with the TEPC.

  13. ADVANCES IN THE RXTE PROPORTIONAL COUNTER ARRAY CALIBRATION: NEARING THE STATISTICAL LIMIT

    Energy Technology Data Exchange (ETDEWEB)

    Shaposhnikov, Nikolai [CRESST and Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Jahoda, Keith; Markwardt, Craig; Swank, Jean; Strohmayer, Tod, E-mail: nikolai.v.shaposhnikov@nasa.gov [Astrophysics Science Division, Goddard Space Flight Center, NASA, Greenbelt, MD 20771 (United States)

    2012-10-01

    During its 16 years of service, the Rossi X-Ray Timing Explorer (RXTE) mission has provided an extensive archive of data, which will serve as a primary source of high cadence observations of variable X-ray sources for fast timing studies. It is, therefore, very important to have the most reliable calibration of RXTE instruments. The Proportional Counter Array (PCA) is the primary instrument on board RXTE which provides data in 3-50 keV energy range with submillisecond time resolution in up to 256 energy channels. In 2009, the RXTE team revised the response residual minimization method used to derive the parameters of the PCA physical model. The procedure is based on the residual minimization between the model spectrum for Crab Nebula emission and a calibration data set consisting of a number of spectra from the Crab and the on-board Am{sub 241} calibration source, uniformly covering the whole RXTE mission operation period. The new method led to a much more effective model convergence and allowed for better understanding of the PCA energy-to-channel relationship. It greatly improved the response matrix performance. We describe the new version of the RXTE/PCA response generator PCARMF v11.7 (HEASOFT Release 6.7) along with the corresponding energy-to-channel conversion table (version e05v04) and their difference from the previous releases of PCA calibration. The new PCA response adequately represents the spectrum of the calibration sources and successfully predicts the energy of the narrow iron emission line in Cas-A throughout the RXTE mission.

  14. A modular large-area lithium foil multi-wire proportional counter neutron detector

    Science.gov (United States)

    Nelson, Kyle A.; Edwards, Nathaniel S.; Kusner, Michael R.; Mayhugh, Michael R.; Montag, Benjamin W.; Schmidt, Aaron J.; Wayant, Clayton D.; McGregor, Douglas S.

    2015-11-01

    Several Li foil multi-wire proportional counters were constructed with five layers of 75 μm thick 6Li foils spaced 1.63 cm apart. Each detector had 1250 cm2 of active area and was backfilled with 1.0 atm of P-10 gas. Two of these detectors were positioned back-to-front with 5.0 cm of high-density polyethylene (HDPE) positioned between the two detectors and on the front and back. Additional 2.54 cm thick HDPE sheets were added to the remaining sides. The detectors were operated with a single electronics unit and were delivered to a test facility where multiple neutron and gamma-ray sensitivity experiments were completed. First, a 252Cf neutron source was positioned at various distances from the front of the detector and the absolute detection efficiency (cps ng-1) was recorded at each distance. Second, a transient test was completed by moving the neutron source in front of the detector at a constant rate while recording the change in count rate (cps). Third, the lateral sensitivity and symmetry of the detection system was investigated by positioning a 252Cf source up to 5.0 m away from the centerline of the arrayed detectors in 1.0 m increments in both outward directions. The angular response was investigated by positioning the 252Cf source 2.0 m from the center of the device and recording the count rate at each stationary position in 15° increments from 0° to 360°. The count rate varied 15% from minimum to maximum during the angular response test. Additionally, the arrayed system was modeled in MCNP6 and had an intrinsic neutron detection efficiency of 12.6% for a bare 252Cf source, less than the experimentally determined efficiency of 13.9±0.03%, as expected. The gamma-ray sensitivity of the detection system was also investigated and pulse-height spectra were collected and plotted against a neutron response spectrum for comparison.

  15. A technique for searching for the 2 K capture in 124Xe with a copper proportional counter

    Science.gov (United States)

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

    2015-12-01

    An experimental technique for searching for the 2 K capture in 124Xe with a large low-background copper proportional counter is described. Such an experiment is conducted at the Baksan Neutrino Observatory of the Institute for Nuclear Research of the Russian Academy of Sciences. The experimental setup is located in the Low-Background Deep-Level Laboratory at a depth of 4900 m.w.e., where the flux of muons of cosmic rays is suppressed by a factor of 107 relative to that at the Earth's surface. The setup incorporates a proportional counter and low-background shielding (18 cm of copper, 15 cm of lead, and 8 cm of borated polyethylene). The results of processing the data obtained in 5 months of live measurement time are presented. A new limit on the half-life of 124Xe with respect to the 2 K capture is set at the level of 2.5 × 1021 years.

  16. Absolute Calibration of Proportional Counter Based Fast Pulsed Neutron Detectors with Resolution Below 105 neutron/pulse

    Science.gov (United States)

    Tarifeño-Saldivia, A.; Mayer, R. E.; Pavez, C.; Soto, L.

    2014-05-01

    A method for absolute calibration of proportional counters for pulsed fast neutrons is presented. The method is based on the use of an isotopic standard source and development of a model for counting detected events from area of a signal compounded by single piled up neutron pulses. Effects of detection counting statistics and electrical background noise are also considered. The method is applied in detectors used for D-D neutron yield measurements in low emission plasma focus devices.

  17. Calibration of a low background gas-flow proportional counter to estimate (234)Th activity in coastal waters.

    Science.gov (United States)

    Cuesta, E; Lozano, R L; Miguel, E G San; Casas-Ruiz, M; Bolívar, J P

    2016-12-01

    This paper relates the calibration of a low background gas-flow proportional counter. This calibration has been used to determine low activity of (234)Th in coastal water samples. Two methods were used to prepare calibration samples: Evaporation and Electrodeposition. First method was rejected due to the lack of reproducibility because the different geometry adopted by the drops of tracer once dried on the disk. On the contrary, through the second method, similar efficiencies were obtained in all detectors with an average of 0.401±0.004. In this paper, the whole procedure to obtain (234)Th activity in dissolution as well as in particulate matter has been detailed, and all the algorithms needed to calculate activities and efficiencies are shown. Finally, two experiments have been designed in order to validate the calibration of the beta counter and the method to determine (234)Th in coastal waters with high concentration of particulate matter.

  18. A curved-grid gas proportional scintillation counter instrumented with a 25-mm active-diameter photosensor

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, C.M.B.; Morgado, R.E.; Santos, J.M.F. dos E-mail: jmf@gian.fis.uc.pt; Conde, C.A.N

    2004-04-21

    The curved-grid technique provides a simple method to compensate for the variation in solid angle viewed by the PMT in large-area gas proportional scintillation counters (GPSC), improving their performance. The scintillation region is delimited by a planar grid and a curved one, whose shape is calculated to produce a radially increasing scintillation yield, compensating for the decrease in the solid angle. In this work, we applied this technique to a GPSC instrumented with a PMT having a 25-mm diameter photocathode. The maximum ratio of the detector entrance window to the photocathode diameter thus far achieved, without significant performance degradation, is 1.

  19. Gas-multiplication factor of a proportional counter operated at low temperature described with the Diethorn, Rose-Korff and townsend expressions

    Energy Technology Data Exchange (ETDEWEB)

    Fukumura, Kazuko; Nakanishi, Akio; Kobayashi, Takayuki [Shiga Univ. of Medical Science, Otsu (Japan)

    1996-07-01

    In the present work, the gas-multiplication factor is expressed with the Rose-Korff and Townsend methods as well as with the Diethorn method. A proportional counter with helium or neon works only at low temperature. This is discussed in terms of the number of electrons emitted when an ion is neutralized at the cathode of the counter. (J.P.N.)

  20. Precision measurement of thermal neutron beam densities using a 3He proportional counter

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Bahnsen, A.; Brown, W.K.

    1967-01-01

    A new method, based on the 3He(n, p)T reaction, has been developed for the accurate determination of thermal neutron beam densities. Several comparisons were made with the conventional Au-foil activation method, and agreement was obtained between the two methods within an experimental uncertainty...... of ±0.4%. Fundamental advantages of the method include the 1ν dependence of the 3He(n, p)T cross section up to 1 keV, and the assurance of homogeneity even for very small macroscopic cross sections, because of the gaseous detector material. Although the method requires a relatively clean neutron beam......, it can be used over a wide range of neutron densities and, in particular, is capable of measuring extremely weak beams. A detector has been constructed with a well-defined efficiency and which is able to accept beams of diameters up to 10 cm. The 3He counter method is proposed as a precision standard...

  1. Basic design of a multi wire proportional counter using Garfield++ for ILSF

    Science.gov (United States)

    Ghahremani Gol, M.; Ashrafi, S.; Rahighi, J.

    2016-12-01

    The Iranian Light Source Facility (ILSF) is a new 3 GeV third generation synchrotron radiation facility in Middle East, which at the time being is in its design stage. An important aspect for the scientific success of this new source will be the availability of well adapted detectors. Position-sensitive X-ray detectors have played an important role in synchrotron radiation X-ray experiments for many years and are still in use. An operational one-dimensional multiwire position sensitive detector with delay line readout produced by ILSF showed a position resolution of 230 μm. In this paper, we introduce a 2-D position sensitive gas detector based on a multiwire proportional chamber which will be used in small/wide angle scattering and diffraction experiments with synchrotron radiation at the ILSF. The parameters of its components, including the gas filling, gas pressure, temperature, the geometry of anode and cathodes planes as well as the expected performance of the designed system will be described in the following. For the design and the simulation of MWPC the Elmer and Garfield++ codes have been employed. We have built and tested a MWPC as a prototype at ILSF. The results obtained so far show a good position sensing. After primary test the detector has been optimized and is now ready for test at Elettra.

  2. A new integrated photosensor for gas proportional scintillation counters based on the gas electron multiplier (GEM)

    CERN Document Server

    Lopes, J A M; Conde, C A N; Morgado, R E

    1999-01-01

    The performance of a novel integrated photosensor for use in a xenon gas proportional scintillation detector is described. Earlier integrated photo-sensor designs were limited in charge gains due to the onset of electrical breakdown, which was ascribed to optical positive feedback from scintillation photons produced in the charge amplification stage. The present design uses a gas electron multiplier (GEM) composed of a 50 mu m thick Kapton film with copper-plated electrode surfaces on both sides and perforated with 200 mu m holes at a 300 mu m pitch. The front surface is made photosensitive with a 150-nm-thick CsI film. When an appropriate voltage is applied between the copper electrodes, the resulting electric field directs photoelectrons produced on the front surface through the holes in the GEM and onto a wire chamber where charge amplification occurs. Optical positive feedback is essentially eliminated since the charge amplification stage is optically de-coupled from the photocathode. The GEM also provide...

  3. Response of a proportional counter to $^{37}$Ar and $^{71}$Ge: real spectra versus GEANT4 simulation

    CERN Document Server

    Abdurashitov, D; Matushko, V; Suerfu, B

    2015-01-01

    The energy deposition spectra of $^{37}$Ar and $^{71}$Ge in a miniature proportional counter are measured and compared in detail to the model response simulated with Geant4. The spectrum of $^{71}$Ge is measured with total statistics of 1.7$\\cdot$10$^8$ events and is presented for the first time. A certain modification of the Geant4 code, making it possible to trace the deexcitation of atomic shells properly, is suggested. After the modification Geant4 is able to reproduce a response of particle detectors in detail in a keV energy range. This feature is very important in the laboratory experiments that search for massive sterile neutrinos as well as for dark matter directly by detection of recoil nuclei. We expect this work to convince physicists to trust Geant4 simulations at low energies.

  4. Comparative analysis of spectra of the background of the proportional counter filled with Kr, enriched in Kr-78, and with Kr of natural content

    OpenAIRE

    Gavriljuk, Yu. M.; Gavrin, V. N.; Gangapshev, A. M.; Kazalov, V. V.; Kuzminov, V. V.; Panasenko, S. I.; Ratkevich, S. S.

    2007-01-01

    The results of the experiment searching for 2K-capture with large low-background proportional counter are presented. The comparison of spectra of the background of the proportional counter filled with Kr enriched in $^{78}$Kr (8400 hr) and with natural Kr (3039 hr) is given. A new limit on the half-life of $^{78}$Kr with regard to 2K-capture, T$_{1/2}\\geq2.0\\cdot10^{21}$ yrs (95% C.L.) has been obtained.

  5. Measurement and analysis of neutron flux distribution of STACY heterogeneous core by position sensitive proportional counter. Contract research

    CERN Document Server

    Murazaki, M; Uno, Y

    2003-01-01

    We have measured neutron flux distribution around the core tank of STACY heterogeneous core by position sensitive proportional counter (PSPC) to develop the method to measure reactivity for subcritical systems. The neutron flux distribution data in the position accuracy of +-13 mm have been obtained in the range of uranium concentration of 50g/L to 210g/L both in critical and in subcritical state. The prompt neutron decay constant, alpha, was evaluated from the measurement data of pulsed neutron source experiments. We also calculated distribution of neutron flux and sup 3 He reaction rates at the location of PSPC by using continuous energy Monte Carlo code MCNP. The measurement data was compared with the calculation results. As results of comparison, calculated values agreed generally with measurement data of PSPC with Cd cover in the region above half of solution height, but the difference between calculated value and measurement data was large in the region below half of solution height. On the other hand, ...

  6. Measurement and analysis of neutron flux distribution of STACY heterogeneous core by position sensitive proportional counter. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Murazaki, Minoru; Uno, Yuichi; Miyoshi, Yoshinori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    We have measured neutron flux distribution around the core tank of STACY heterogeneous core by position sensitive proportional counter (PSPC) to develop the method to measure reactivity for subcritical systems. The neutron flux distribution data in the position accuracy of {+-}13 mm have been obtained in the range of uranium concentration of 50g/L to 210g/L both in critical and in subcritical state. The prompt neutron decay constant, {alpha}, was evaluated from the measurement data of pulsed neutron source experiments. We also calculated distribution of neutron flux and {sup 3}He reaction rates at the location of PSPC by using continuous energy Monte Carlo code MCNP. The measurement data was compared with the calculation results. As results of comparison, calculated values agreed generally with measurement data of PSPC with Cd cover in the region above half of solution height, but the difference between calculated value and measurement data was large in the region below half of solution height. On the other hand, calculated value agreed well with measurement data of PSPC without Cd cover. (author)

  7. Measurement and simulation of lineal energy distribution at the CERN high energy facility with a tissue equivalent proportional counter.

    Science.gov (United States)

    Rollet, S; Autischer, M; Beck, P; Latocha, M

    2007-01-01

    The response of a tissue equivalent proportional counter (TEPC) in a mixed radiation field with a neutron energy distribution similar to the radiation field at commercial flight altitudes has been studied. The measurements have been done at the CERN-EU High-Energy Reference Field (CERF) facility where a well-characterised radiation field is available for intercomparison. The TEPC instrument used by the ARC Seibersdorf Research is filled with pure propane gas at low pressure and can be used to determine the lineal energy distribution of the energy deposition in a mass of gas equivalent to a 2 microm diameter volume of unit density tissue, of similar size to the nuclei of biological cells. The linearity of the detector response was checked both in term of dose and dose rate. The effect of dead-time has been corrected. The influence of the detector exposure location and orientation in the radiation field on the dose distribution was also studied as a function of the total dose. The microdosimetric distribution of the absorbed dose as a function of the lineal energy has been obtained and compared with the same distribution simulated with the FLUKA Monte Carlo transport code. The dose equivalent was calculated by folding this distribution with the quality factor as a function of linear energy transfer. The comparison between the measured and simulated distributions show that they are in good agreement. As a result of this study the detector is well characterised, thanks also to the numerical simulations the instrument response is well understood, and it's currently being used onboard the aircrafts to evaluate the dose to aircraft crew caused by cosmic radiation.

  8. Tissue equivalent proportional counter microdosimetry measurements utililzed aboard aircraft and in accelerator based space radiation shielding studies

    Science.gov (United States)

    Gersey, Brad; Wilkins, Richard

    The space radiation environment presents a potential hazard to the humans, electronics and materials that are exposed to it. Particle accelerator facilities such as the NASA Space Ra-diation Laboratory (NSRL) and Loma Linda University Medical Center (LLUMC) provide particle radiation of specie and energy within the range of that found in the space radiation environment. Experiments performed at these facilities determine various endpoints for bio-logical, electronic and materials exposures. A critical factor in the performance of rigorous scientific studies of this type is accurate dosimetric measurements of the exposures. A Tissue Equivalent Proportional Counter (TEPC) is a microdosimeter that may be used to measure absorbed dose, average quality factor (Q) and dose equivalent of the particle beam utilized in these experiments. In this work, results from a variety of space radiation shielding studies where a TEPC was used to perform dosimetry in the particle beam will be presented. These results compare the absorbed dose and dose equivalent measured downstream of equal density thicknesses of stan-dard and multifunctional shielding materials. The standard materials chosen for these shielding studies included High-Density Polyethylene (HDPE) and aluminum alloy, while the multifunc-tional materials included carbon composite infused with single walled carbon nanotubes. High energy particles including proton, silicon and iron nuclei were chosen as the incident radia-tion for these studies. Further, TEPC results from measurements taken during flights aboard ER-2 and KC-135 aircraft will also be discussed. Results from these flight studies include TEPC measurements for shielded and unshielded conditions as well as the effect of vibration and electromagnetic exposures on the TEPC operation. The data selected for presentation will highlight the utility of the TEPC in space radiation studies, and in shielding studies in particular. The lineal energy response function of the

  9. First results of a simultaneous measurement of tritium and 14C in an ultra-low-background proportional counter for environmental sources of methane

    Energy Technology Data Exchange (ETDEWEB)

    Mace, Emily K.; Aalseth, Craig E.; Day, Anthony R.; Hoppe, Eric W.; Keillor, Martin E.; Moran, James J.; Panisko, Mark E.; Seifert, Allen; Tatishvili, Gocha; Williams, Richard M.

    2016-02-01

    Abstract Simultaneous measurement of tritium and 14C would provide an added tool for tracing organic compounds through environmental systems and is possible via beta energy spectroscopy of sample-derived methane in internal-source gas proportional counters. Since the mid-1960’s atmospheric tritium and 14C have fallen dramatically as the isotopic injections from above-ground nuclear testing have been diluted into the ocean and biosphere. In this work, the feasibility of simultaneous tritium and 14C measurements via proportional counters is revisited in light of significant changes in both the atmospheric and biosphere isotopics and the development of new ultra-low-background gas proportional counting capabilities for small samples (roughly 50 cc methane). A Geant4 Monte Carlo model of a Pacific Northwest National Laboratory (PNNL) proportional counter response to tritium and 14C is used to analyze small samples of two different methane sources to illustrate the range of applicability of contemporary simultaneous measurements and their limitations. Because the two methane sources examined were not sample size limited, we could compare the small-sample measurements performed at PNNL with analysis of larger samples performed at a commercial laboratory. The dual-isotope simultaneous measurement is well matched for methane samples that are atmospheric or have an elevated source of tritium (i.e. landfill gas). For samples with low/modern tritium isotopics (rainwater), commercial separation and counting is a better fit.

  10. First results of a simultaneous measurement of tritium and (14)C in an ultra-low-background proportional counter for environmental sources of methane.

    Science.gov (United States)

    Mace, E K; Aalseth, C E; Day, A R; Hoppe, E W; Keillor, M E; Moran, J J; Panisko, M E; Seifert, A; Tatishvili, G; Williams, R M

    2016-05-01

    Simultaneous measurement of tritium and (14)C would provide an added tool for tracing organic compounds through environmental systems and is possible via beta energy spectroscopy of sample-derived methane in internal-source gas proportional counters. Since the mid-1960's atmospheric tritium and (14)C have fallen dramatically as the isotopic injections from aboveground nuclear testing have been diluted into the ocean and biosphere. In this work, the feasibility of simultaneous tritium and (14)C measurements via proportional counters is revisited in light of significant changes in both the atmospheric and biosphere isotopics and the development of new ultra-low-background gas proportional counting capabilities for small samples (roughly 50 cc methane). A Geant4 Monte Carlo model of a Pacific Northwest National Laboratory (PNNL) proportional counter response to tritium and (14)C is used to analyze small samples of two different methane sources to illustrate the range of applicability of contemporary simultaneous measurements and their limitations. Because the two methane sources examined were not sample size limited, we could compare the small-sample measurements performed at PNNL with analysis of larger samples performed at a commercial laboratory. These first results show that the dual-isotope simultaneous measurement is well matched for methane samples that are atmospheric or have an elevated source of tritium (i.e. landfill gas). However, for samples with low/modern tritium isotopics (rainwater), commercial separation and counting is a better fit.

  11. He-3 in diamonds - The cosmogenic component

    Science.gov (United States)

    Lal, D.; Craig, H.; Wacker, J. F.; Poreda, R.

    1989-02-01

    Results are presented of measurements of He-3 and He-4 concentrations in diamonds received directly from mines, as well as in industrual samples. None of the diamonds recovered from underground mining was found to have a He-3/He-4 ratio, R, exceeding three times the atmospheric He-3/He-4 ratio R(A), while one of the industrial diamonds was found to have an R value of 142 R(A). It is concluded that the hypothesis of Ozima et al. (1983) of high primordial He-3/He-4 ratios in diamonds exceeding MORB ratios is not required. The present findings on the He-3/He-4 ratios are explained as the result of cosmogenic and nucleogenic production of He-3 within the diamonds.

  12. Neutron dosimetry using proportional counters with tissue equivalent walls; Dosimetrie des neutrons au moyen de compteurs proportionnels a paroi equivalente aux tissus

    Energy Technology Data Exchange (ETDEWEB)

    Kerviller, H. de [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    The author reminds the calculation method of the neutron absorbed dose in a material and deduce of it the conditions what this material have to fill to be equivalent to biological tissues. Various proportional counters are mode with walls in new tissue equivalent material and filled with various gases. The multiplication factor and neutron energy response of these counters are investigated and compared with those obtained with ethylene lined polyethylene counters. The conditions of working of such proportional counters for neutron dosimetry in energy range 10{sup -2} to 15 MeV are specified. (author) [French] L'auteur rappelle la methode de calcul de la dose absorbee due aux neutrons dans un materiau et en deduit les conditions que dolt remplir ce materiau pour titre equivalent aux tissus biologiques. Divers compteurs proportionnels sont realises avec des parois en nouveau materiau equivalent aux tissus et remplis de divers gaz. Les coefficients de multiplication et la reponse en fonction de l'energie des neutrons sont etudies et compares avec ceux de compteurs a paroi de polyethylene et remplis d'ethylene, Les conditions de fonctionnement de tels compteurs proportionnels pour la dosimetrie des neutrons d'energie 10{sup -2} a 15 MeV sont precisees. (auteur)

  13. He-3 in galactic cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Mewaldt, R.A.

    1986-12-01

    Cosmic-ray He-3/He-4 observations, including a new measurement around 65 MeV per nucleon from ISEE-3, are compared with interstellar propagation and solar modulation calculations in an effort to understand the origin of cosmic-ray He nuclei. A survey of spacecraft and balloon observations of the He-3/He-4 ratio shows improved consistency among measurements in the 50-300 MeV per nucleon energy range when a previously neglected contribution from atmospheric secondary He-3 is taken into account. These low-energy observations imply a mean escape length of 6-8 g/sq cm in the standard leaky box model for cosmic-ray propagation in the Galaxy, a value consistent with that derived from studies of heavier nuclei. No evidence is found for an excess of low-energy He-3 such as that reported at high energies. 42 references.

  14. The generalized GDH sum for He-3

    Energy Technology Data Exchange (ETDEWEB)

    Karl Slifer

    2004-06-02

    The Burkhardt-Cottingham, Bjorken and generalized GDH sum rules are all consequences of the Q^2-dependent dispersion relations for the virtual photon Compton amplitudes. These integrals are investigated for a He-3 target at low Q^2.

  15. First result of the experimental search for the 9.4 keV solar axion reactions with Kr-83 in the copper proportional counter

    OpenAIRE

    Gavrilyuk, Yu. M.; Gangapshev, A. M.; Derbin, A. V.; Kazalov, V. V.; Kim, H. J.; Kim, Y.D.(Center for Underground Physics, Institute for Basic Science (IBS), Daejon, 305-811, Korea); Kobychev, V. V.; Kuzminov, V. V.; Ali, Luqman; Muratova, V. N.; Panasenko, S. I.; Ratkevich, S. S.; Semenov, D. A.; Tekueva, D. A.; Yakimenko, S. P.

    2014-01-01

    The experimental search for solar hadronic axions is started at the Baksan Neutrino Observatory of the Institute for Nuclear Researches Russian Academy of Science. It is assumed that axions are created in the Sun during M1-transition between the first thermally excited level at 9.4 keV and the ground state in Kr-83. The experiment is based on axion detection via resonant absorption process by the same nucleus in the detector. The big copper proportional counter filled with krypton is used to ...

  16. Measurement of the differential neutron-deuteron scattering cross section in the energy range from 100 keV to 600 keV using a proportional counter

    CERN Document Server

    Nolte, R; Plompen, A; Röttger, S

    2014-01-01

    The angular distribution of neutron-deuteron scattering was investigated using the proportional counter P2 simultaneously as scattering target and detector for the recoil deuterons. The measurements were carried out using monoenergetic neutrons in the energy range from 150 keV to 500 keV. Various techniques were employed to reduce distortions of the experimental pulse-height distribution by photon-induced events. The experimental data were compared with realistic simulations which were carried out using different evaluated data sets. This comparison allows to conclude on inconsistencies in the evaluations.

  17. TECHNICAL DESIGN NOTE: System for measurement of low yield neutron pulses from D D fusion reactions based upon a 3He proportional counter

    Science.gov (United States)

    Moreno, José; Birstein, Lipo; Mayer, Roberto E.; Silva, Patricio; Soto, Leopoldo

    2008-08-01

    A conventional neutron detection technique was adapted to measure low neutron yields from D-D fusion pulses. This method uses a 3He proportional counter surrounded by a paraffin moderator. Electric signals generated in the 3He tube are fed into a preamplifier. The output of the preamplifier is directly connected to a digital oscilloscope. The time-integrated signals represent the charge generated in the 3He tube which is proportional to the total neutron yield. The integration time is determined by the preamplifier and moderator characteristics within some hundreds of microseconds. No meaningful neutron background was detected during this time window. The system, previously calibrated, was used to measure the neutron yield (low as 103 neutrons per pulse were measured.

  18. Monte Carlo calculations and experimental results of Bonner spheres systems with a new cylindrical Helium-3 proportional counter

    CERN Document Server

    Müller, H; Bouassoule, T; Fernández, F; Pochat, J L; Tomas, M; Van Ryckeghem, L

    2002-01-01

    The experimental results on neutron energy spectra, integral fluences and equivalent dose measurements performed by means of a Bonner sphere system placed inside the containment building of the Vandellos II Nuclear Power Plant (Tarragona, Spain) are presented. The equivalent dose results obtained with this system are compared to those measured with different neutron area detectors (Berthold, Dineutron, Harwell). A realistic geometry model of the Bonner sphere system with a new cylindrical counter type 'F' (0,5NH1/1KI--Eurisys Mesures) and with a set of eight polyethylene moderating spheres is described in detail. The response function in fluence of this new device, to mono-energetic neutrons from thermal energy to 20 MeV, is calculated by the MCNP-4B code for each moderator sphere. The system has been calibrated at IPSN Cadarache facility for ISO Am-Be calibrated source and thermal neutron field, then the response functions were confirmed by measurements at PTB (Germany) for ISO recommended energies of mono-e...

  19. Monte Carlo calculations and experimental results of Bonner spheres systems with a new cylindrical Helium-3 proportional counter

    Science.gov (United States)

    Muller, H.; Fernández, F.; Van Ryckeghem, L.; Alexandre, P.; Bouassoule, T.; Pochat, J.-L.; Tomas, M.

    2002-01-01

    The experimental results on neutron energy spectra, integral fluences and equivalent dose measurements performed by means of a Bonner sphere system placed inside the containment building of the Vandellòs II Nuclear Power Plant (Tarragona, Spain) are presented. The equivalent dose results obtained with this system are compared to those measured with different neutron area detectors (Berthold, Dineutron, Harwell). A realistic geometry model of the Bonner sphere system with a new cylindrical counter type "F" (0,5NH1/1KI—Eurisys Mesures) and with a set of eight polyethylene moderating spheres is described in detail. The response function in fluence of this new device, to mono-energetic neutrons from thermal energy to 20 MeV, is calculated by the MCNP-4B code for each moderator sphere. The system has been calibrated at IPSN Cadarache facility for ISO Am-Be calibrated source and thermal neutron field, then the response functions were confirmed by measurements at PTB (Germany) for ISO recommended energies of mono-energetic neutrons and with the CANEL IPSN facility which simulates realistic fields.

  20. A rocket-borne He-3 refrigerator

    Science.gov (United States)

    Duband, L.; Alsop, D.; Lange, A.; Kittel, P.

    A self-contained, recyclable He-3 refrigerator suitable for use in space has been developed. The refrigerator is compact, has no moving parts, and requires only electrical connections and thermal contact in order to operate from a 2 K cold stage. A charcoal adsorption pump is used to efficiently condense and cool the He-3. Sintered copper confines the He-3 to the evaporator in zero-gravity and, in fact, allows the refrigerator to operate upside-down in the laboratory. Mounted on a 2 K cold stage, the refrigerator provides 100 microwatts of cooling power at 346 mK, with a 7 hour hold time. On a 1.5 K cold stage, the lowest temperature achieved is 277 mK. The refrigerator has been vibration tested at 7.5 G amplitude from 30 to 400 Hz and 15 G amplitude from 400 to 2000 Hz.

  1. Nuclear-pumped lasing of /He-3/-Xe and /He-3/-Kr

    Science.gov (United States)

    De Young, R. J.; Jalufka, N. W.; Hohl, F.

    1977-01-01

    The letter reports direct nuclear pumping of (He-3)-Xe and (He-3)-Kr using the volumetric He-3(n,p)H-3 nuclear reaction. Lasing in (He-3)-Xe was achieved at the 2.027-micron transition of Xe I; lasing in (He-3)-Kr is assumed to have occurred at the 2.52-micron transition of Kr I. Experimental results show that laser output in (He-3)-Xe increases and tends to saturate with increasing pressure, the lasing neutron-flux threshold decreases with decreasing neutron pulse, and maximum output occurs between 0.1% and 0.5% Xe with the total pressure held constant at 400 torr and with an average neutron flux of 6 by 10 to the 15th power per sq cm/sec. It is noted that the (He-3)-Xe laser has the lowest lasing-threshold neutron flux of any He-3 nuclear-pumped laser to date, but the (He-3)-Kr laser has a very high threshold flux. The primary lasing mechanism is believed to be Penning ionization of Xe and Kr followed by collisional radiative recombination and cascading into the upper laser level.

  2. Novel and efficient {sup 10}B lined tubelet detector as a replacement for {sup 3}He neutron proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Tsorbatzoglou, Kyriakos [Centronic LLC, 16203 Park Row, Houston, TX 77084 (United States); McKeag, Robert D., E-mail: info@centronic.us [Centronic Limited, Centronic House, King Henry' s Drive, Croydon CR9 0BG (United Kingdom)

    2011-10-01

    This paper presents a novel and robust proportional detector which addresses the well publicized shortage of {sup 3}He gas by using a {sup 10}B lining applied to a tubelet configuration. The advantage of the tubelet structure is that it yields a detector maintaining the form factor of a conventional {sup 3}He tube whilst achieving a sensitivity of up to 75% of a 3 atm {sup 3}He device. The design and fabrication of the tubelet detector is presented and discussed with test data comparing the new detector to existing {sup 3}He and BF{sub 3} tubes. The application of the tubelet design to security and industrial applications including retro-fitting to existing portals and suitability for high integrity oil and gas installations is addressed.

  3. Neutron Beam Effects on Spin Exchange Polarized He-3

    CERN Document Server

    Sharma, M; Andersen, K H; Barron-Palos, L; Becker, M; Boag, S; Chen, W C; Chupp, T E; Danagoulian, A; Gentile, T R; Klein, A; Penttila, S; Petoukhov, A; Soldner, T; Tardiff, E R; Walker, T G; Wilburn, W S

    2008-01-01

    We have observed depolarization effects when high intensity cold neutron beams are incident on alkali-metal-spin-exchange polarized He-3 cells used as neutron spin filters. This was first observed as a reduction of the maximum attainable He-3 polarization and was attributed to a decrease of alkali-metal polarization, which led us to directly measure alkali-metal polarization and spin relaxation over a range of neutron fluxes at LANSCE and ILL. The data reveal a new alkali-metal spin-relaxation mechanism that approximately scales as the square root of the neutron capture-flux density incident on the cell. This is consistent with an effect proportional to the recombination-limited ion concentration, but is much larger than expected from earlier work.

  4. 一种改善闭气式正比计数器换气周期的方法%A Method for Optimising the Gas Replacing Period of Sealed Proportional Counter

    Institute of Scientific and Technical Information of China (English)

    张勇; 杨勇

    2011-01-01

    Proportional counter can be used as low - energy particles detector because of its gas gain. According to charging manner, proportional counter can be divided into sealed and gas -flow proportional counters. Compared with gas - flow counter, although sealed proportional counter can be operated simply but it is short -lived, needs to replace the sealed gas periodically. It introduces the aging phenomenon of sealed proportional counter and a method for optimising the gas replacing period.%正比计数器具有气体放大作用,很适合用于低能粒子探测.用于低能X射线和α/β污染监测时,正比计数器按充气方式可以划分为两大类:流气式和闭气式.与流气式相比,闭气式正比计数器使用方便;但是其寿命比较短,需要周期性更换工作气体.介绍了闭气式正比计数器性能老化问题,以及一种改善其换气周期的方法.

  5. First result of the experimental search for the 9.4 keV solar axion reactions with Kr-83 in the copper proportional counter

    CERN Document Server

    Gavrilyuk, Yu M; Derbin, A V; Kazalov, V V; Kim, H J; Kim, Y D; Kobychev, V V; Kuzminov, V V; Ali, Luqman; Muratova, V N; Panasenko, S I; Ratkevich, S S; Semenov, D A; Tekueva, D A; Yakimenko, S P; Unzhakov, E V

    2014-01-01

    The experimental search for solar hadronic axions is started at the Baksan Neutrino Observatory of the Institute for Nuclear Researches Russian Academy of Science. It is assumed that axions are created in the Sun during M1-transition between the first thermally excited level at 9.4 keV and the ground state in Kr-83. The experiment is based on axion detection via resonant absorption process by the same nucleus in the detector. The big copper proportional counter filled with krypton is used to detect signals from axions. The experimental setup is situated in the deep underground low background laboratory. No evidence of axion detection were found after the 26.5 days data collection. Resulting new upper limit on axion mass is m_{A} < 130 eV at 95% C.L.

  6. First result of the experimental search for the 9.4 keV solar axion reactions with 83Kr in the copper proportional counter

    Science.gov (United States)

    Gavrilyuk, Yu. M.; Gangapshev, A. M.; Derbin, A. V.; Kazalov, V. V.; Kim, H. J.; Kim, Y. D.; Kobychev, V. V.; Kuzminov, V. V.; Ali, Luqman; Muratova, V. N.; Panasenko, S. I.; Ratkevich, S. S.; Semenov, D. A.; Tekueva, D. A.; Yakimenko, S. P.; Unzhakov, E. V.

    2015-03-01

    The experimental search for solar hadronic axions is started at the Baksan Neutrino Observatory of the Institute for Nuclear Researches of Russian Academy of Science (BNO INR RAS). It is assumed that axions are created in the Sun during M1 transition between the first thermally excited level at 9.4 keV and the ground state in 83Kr. The experiment is based on axion detection via resonant absorption process by the same nucleus in the detector. The big copper proportional counter filled with krypton is used to detect signals from axions. The experimental setup is situated in the deep underground low background laboratory. No evidence of axion detection were found after the 26.5 days data collection. Resulting new upper limit on axion mass is m A ≤ 130 eV at 95% C.L.

  7. An Independent Measurement of the Total Active 8B Solar Neutrino Flux Using an Array of 3He Proportional Counters at the Sudbury Neutrino Observatory

    CERN Document Server

    Aharmim, B; Amsbaugh, J F; Anthony, A E; Banar, J; Barros, N; Beier, E W; Bellerive, A; Beltran, B; Bergevin, M; Biller, S D; Boudjemline, K; Boulay, M G; Bowles, T J; Browne, M C; Bullard, T V; Burritt, T H; Cai, B; Chan, Y D; Chauhan, D; Chen, M; Cleveland, B T; Cox-Mobrand, G A; Currat, C A; Dai, X; Deng, H; Detwiler, J; Di Marco, M; Doe, P J; Doucas, G; Drouin, P L; Duba, C A; Duncan, F A; Dunford, M; Earle, E D; Elliott, S R; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Ford, R J; Formaggio, J A; Fowler, M M; Gagnon, N; Germani, J V; Goldschmidt, A; Goon, J T M; Graham, K; Guillian, E; Habib, S; Hahn, R L; Hallin, A L; Hallman, E D; Hamian, A A; Harper, G C; Harvey, P J; Hazama, R; Heeger, K M; Heintzelman, W J; Heise, J; Helmer, R L; Henning, R; Hime, A; Howard, C; Howe, M A; Huang, M; Jagam, P; Jamieson, B; Jelley, N A; Keeter, K J; Klein, J R; Kormos, L L; Kos, M; Krüger, A; Kraus, C; Krauss, C B; Kutter, T; Kyba, C C M; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Loach, J C; MacLellan, R; Majerus, S; Mak, H B; Maneira, J; Martin, R; McBryde, K; McCauley, N; McDonald, A B; McGee, S; Miin, C; Miller, G G; Miller, M L; Monreal, B; Monroe, J; Morissette, B; Myers, A; Nickel, B G; Noble, A J; Oblath, N S; O'Keeffe, H M; Ollerhead, R W; Orebi Gann, G D; Oser, S M; Ott, R A; Peeters, S J M; Poon, A W P; Prior, G; Reitzner, S D; Rielage, K; Robertson, B C; Robertson, R G H; Rollin, E; Schwendener, M H; Secrest, J A; Seibert, S R; Simard, O; Simpson, J J; Sinclair, L; Skensved, P; Smith, M W E; Steiger, T D; Stonehill, L C; Tesic, G; Thornewell, P M; Tolich, N; Tsui, T; Tunnell, C D; Van Wechel, T; Van Berg, R; Van Devender, B A; Virtue, C J; Walker, T J; Wall, B L; Waller, D; Wan Chan Tseung, H; Wendland, J; West, N; Wilhelmy, J B; Wilkerson, J F; Wilson, J R; Wouters, J M; Wright, A; Yeh, M; Zhang, F; Zuber, K

    2008-01-01

    The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54(+0.33/-0.31 stat, +0.36/-0.34 syst) x 10^6 cm^-2 s^-1, in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Delta m^2 = 7.94(+0.42/-0.26) x 10^-5 eV^2 and theta = 33.8(+1.4/-1.3) degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.

  8. Comparisons of LET distributions measured in low-earth orbit using tissue-equivalent proportional counters and the position-sensitive silicon-detector telescope (RRMD-III).

    Science.gov (United States)

    Doke, T; Hayashi, T; Borak, T B

    2001-09-01

    Determinations of the LET distribution, phi(L), of charged particles within a spacecraft in low-Earth orbit have been made. One method used a cylindrical tissue-equivalent proportional counter (TEPC), with the assumption that for each measured event, lineal energy, y, is equal to LET and thus phi(L) = phi(y). The other was based on the direct measurement of LETs for individual particles using a charged-particle telescope consisting of position-sensitive silicon detectors called RRMD-III. There were differences of up to a factor of 10 between estimates of phi(L) using the two methods on the same mission. This caused estimates of quality factor to vary by a factor of two between the two methods.

  9. Independent measurement of the total active 8B solar neutrino flux using an array of 3He proportional counters at the Sudbury Neutrino Observatory.

    Science.gov (United States)

    Aharmim, B; Ahmed, S N; Amsbaugh, J F; Anthony, A E; Banar, J; Barros, N; Beier, E W; Bellerive, A; Beltran, B; Bergevin, M; Biller, S D; Boudjemline, K; Boulay, M G; Bowles, T J; Browne, M C; Bullard, T V; Burritt, T H; Cai, B; Chan, Y D; Chauhan, D; Chen, M; Cleveland, B T; Cox-Mobrand, G A; Currat, C A; Dai, X; Deng, H; Detwiler, J; DiMarco, M; Doe, P J; Doucas, G; Drouin, P-L; Duba, C A; Duncan, F A; Dunford, M; Earle, E D; Elliott, S R; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Ford, R J; Formaggio, J A; Fowler, M M; Gagnon, N; Germani, J V; Goldschmidt, A; Goon, J T M; Graham, K; Guillian, E; Habib, S; Hahn, R L; Hallin, A L; Hallman, E D; Hamian, A A; Harper, G C; Harvey, P J; Hazama, R; Heeger, K M; Heintzelman, W J; Heise, J; Helmer, R L; Henning, R; Hime, A; Howard, C; Howe, M A; Huang, M; Jagam, P; Jamieson, B; Jelley, N A; Keeter, K J; Klein, J R; Kormos, L L; Kos, M; Krüger, A; Kraus, C; Krauss, C B; Kutter, T; Kyba, C C M; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Loach, J C; MacLellan, R; Majerus, S; Mak, H B; Maneira, J; Martin, R; McBryde, K; McCauley, N; McDonald, A B; McGee, S; Mifflin, C; Miller, G G; Miller, M L; Monreal, B; Monroe, J; Morissette, B; Myers, A; Nickel, B G; Noble, A J; Oblath, N S; O'Keeffe, H M; Ollerhead, R W; Gann, G D Orebi; Oser, S M; Ott, R A; Peeters, S J M; Poon, A W P; Prior, G; Reitzner, S D; Rielage, K; Robertson, B C; Robertson, R G H; Rollin, E; Schwendener, M H; Secrest, J A; Seibert, S R; Simard, O; Simpson, J J; Sinclair, L; Skensved, P; Smith, M W E; Steiger, T D; Stonehill, L C; Tesić, G; Thornewell, P M; Tolich, N; Tsui, T; Tunnell, C D; Van Wechel, T; Van Berg, R; VanDevender, B A; Virtue, C J; Walker, T J; Wall, B L; Waller, D; Tseung, H Wan Chan; Wendland, J; West, N; Wilhelmy, J B; Wilkerson, J F; Wilson, J R; Wouters, J M; Wright, A; Yeh, M; Zhang, F; Zuber, K

    2008-09-12

    The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54_-0.31;+0.33(stat)-0.34+0.36(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Deltam2=7.59_-0.21;+0.19x10(-5) eV2 and theta=34.4_-1.2;+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.

  10. MIMAC-He3 : MIcro-tpc MAtrix of Chambers of He3

    CERN Document Server

    Santos, D; Lamy, T; Mayet, F; Moulin, E

    2016-01-01

    The project of a micro-TPC matrix of chambers of He3 for direct detection of non-baryonic dark matter is outlined. The privileged properties of He3 are highlighted. The double detection (ionization - projection of tracks) will assure the electron-recoil discrimination. The complementarity of MIMAC-He3 for supersymmetric dark matter search with respect to other experiments is illustrated. The modular character of the detector allows to have different gases to get A-dependence. The pressure degreee of freedom gives the possibility to work at high and low pressure. The low pressure regime gives the possibility to get the directionality of the tracks. The first measurements of ionization at very few keVs for He3 in He4 gas are described.

  11. Development of a tissue equivalent proportional counter for separation of neutron-gamma mixed field; Desenvolvimento de um contador proporcional equivalente-tecido para separacao de campos mistos neutron-gama

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Abel Antonio da

    1991-01-01

    The construction and development of a proportional counter sensitive to neutrons and gamma rays, which permits to simulate a microscopic region of tissue in order of some microns, is proposed. A spectral distribution in energy from the radiations is obtained from this counter, which treated adequately permits the computation of the absorved dose, dose equivalent and quality factor in a alarge range of energy. (author). 18 refs., 31 figs., 18 tabs.

  12. Commissioning of the proportional counter MPC-9604 for measurement of solid samples originating in the PIMIC project; Puesta punto del contador proporcional MPC-9604 para la medida de muestras solidas originadas en el proyecto PIMIC

    Energy Technology Data Exchange (ETDEWEB)

    Marijuan, M. J.; Suarez-Navarro, J. A.; Quinones, J.

    2012-07-01

    The objective of this work is the development of the proportional counter of continuous gas flow MPC-9604 of PROTEAN, which has recently been acquired by the LPM. Through this proportional counter will determine you Alpha activity and the total beta indices. These indexes will be used for the initial classification of the samples according to its radiological contents and decide if it is necessary further more in-depth analysis. For this we have determined the funds and efficiencies to different potentials and simultaneous measurement mode.

  13. A comparison between the measurements of Kr-85 in environmental samples by liquid scintillation and proportional counters; Comparacion de resultados de la medida radiactiva del Kr-85 ambiental por centelleo liquido y contadores proporcionales

    Energy Technology Data Exchange (ETDEWEB)

    Heras, M. C.; Perez, M. M.

    1983-07-01

    The most used methods for the measurement of Kr-81 beta-activity after their concentration and aisolation are the liquid scintillation counting and the proportional counter. In this work the beta activity of concentrated and aisolated Kr-85 samples measured in collaboration with the Max-Planck Institut fur Kernphyslk, Aussenstelle Freiburg. Samples taken both In Madrid and Frelburg are measured by proportional counters in the Max-Planck lnstitut, Freibury and by liquid scintillation counting in JEN, Madrid. The comparison of both measurements do not show appreciable discrepancy between the results obtained to both techniques. (Author)

  14. Investigations of a recombination chamber as a mixed field dosimeter in comparison with a tissue-equivalent proportional counter at CERF

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Sabine E-mail: sabine.mayer@cern.ch; Otto, Thomas

    2003-06-01

    A comparison of two types of dose equivalent meters, a recombination chamber REM-2 and a tissue-equivalent proportional counter (TEPC) Homburg Area Neutron DosImeter (HANDI), were carried out at the CERN-EC high-energy reference field facility, CERF, in October 2001. Here, the mixed high-energy radiation field in commercial flight altitudes can be simulated with dose rates up to 2 orders of magnitude higher. The total absorbed dose and the dose equivalent have been measured at different radiation field intensities. Of particular interest for measuring in the CERF field is the assessment of the low LET-component, i.e. the {gamma} and muon components of the field, which are not taken into account by existing Monte Carlo simulations modeling the radiation field. The new results for the estimation of the low LET-component are compared with previous ones delivered by REM-2 at CERF. The results show good agreement between the REM-2 chamber and the HANDI.

  15. Investigations of a recombination chamber as a mixed field dosimeter in comparison with a tissue-equivalent proportional counter at CERF

    CERN Document Server

    Mayer, Sabine

    2003-01-01

    A comparison of two types of dose equivalent meters, a recombination chamber REM-2 and a tissue-equivalent proportional counter (TEPC) Homburg Area Neutron DosImeter (HANDI), were carried out at the CERN- EC high-energy reference field facility, CERF, in October 2001. Here, the mixed high-energy radiation field in commercial flight altitudes can be simulated with dose rates up to 2 orders of magnitude higher. The total absorbed dose and the dose equivalent have been measured at different radiation field intensities. Of particular interest for measuring in the CERF field is the assessment of the low LET- component, i.e. the gamma and muon components of the field, which are not taken into account by existing Monte Carlo simulations modeling the radiation field. The new results for the estimation of the low LET-component are compared with previous ones delivered by REM-2 at CERF. The results show good agreement between the REM-2 chamber and the HANDI.

  16. FLUKA simulations of the response of tissue-equivalent proportional counters to ion beams for applications in hadron therapy and space.

    Science.gov (United States)

    Böhlen, T T; Dosanjh, M; Ferrari, A; Gudowska, I; Mairani, A

    2011-10-21

    For both cancer therapy with protons and ions (hadron therapy) and space radiation environments, the spatial energy deposition patterns of the radiation fields are of importance for quantifying the resulting radiation damage in biological structures. Tissue-equivalent proportional counters (TEPC) are the principal instruments for measuring imparted energy on a microscopic scale and for characterizing energy deposition patterns of radiation. Moreover, the distribution of imparted energy can serve as a complementary quantity to particle fluences of the primary beam and secondary fragments for characterizing a radiation field on a physical basis for radiobiological models. In this work, the Monte Carlo particle transport code FLUKA is used for simulating energy depositions in TEPC by ion beams. The capability of FLUKA in predicting imparted energy and derived quantities, such as lineal energy, for microscopic volumes is evaluated by comparing it with a large set of TEPC measurements for different ion beams with atomic numbers ranging from 1 to 26 and energies from 80 up to 1000 MeV/n. The influence of different physics configurations in the simulation is also discussed. It is demonstrated that FLUKA can simulate energy deposition patterns of ions in TEPC cavities accurately and that it provides an adequate description of the main features of the spectra.

  17. Study of the effect of high dose rate on tissue equivalent proportional counter microdosimetric measurements in mixed photon and neutron fields

    Science.gov (United States)

    Aslam; Qashua, N.; Waker, A. J.

    2011-10-01

    This study describes the measurement of lineal energy spectra carried out with a 5.1 cm (2 in.) diameter spherical tissue equivalent proportional counter (TEPC) simulating 2 μm tissue equivalent (TE) site diameter in low energy mixed photon-neutron fields with varying dose rates generated by employing the McMaster University 1.25 MV double stage Tandetron accelerator. The 7Li (p, n) 7Be reaction was employed to generate a variety of mixed fields of photons and low energy neutrons using proton beam energy ranging 1.89-2.56 MeV. The dose rate at a given beam energy was varied by changing the beam current. Dose rates that resulted in dead times as high as 75% were employed to study the effect of dose rate on quality, microdosimetric averages ( y¯F and y¯D), absorbed dose and dose equivalent. We have observed that high dose rates due to both photons and neutrons in a mixed field of radiation result in pile up of pulses and distort the lineal energy spectrum measured under these conditions. The pile up effect and hence the distortion in the lineal energy spectrum becomes prominent with dose rates, which result in dead times larger than 25% for the high linear energy transfer (LET) radiation component. Intense neutron fields, which may amount to 75% dead time, could result in a 50% or even larger increase in the values of the microsdosimetric averages and the neutron quality factor. This study demonstrates moderate dose rates that do not result in dead times of more than 20-25% due to either of the component radiation or due to both components of mixed field radiation generate results that are acceptable for radiation monitoring.

  18. Broad Energy Range Neutron Spectroscopy using a Liquid Scintillator and a Proportional Counter: Application to a Neutron Spectrum Similar to that from an Improvised Nuclear Device.

    Science.gov (United States)

    Xu, Yanping; Randers-Pehrson, Gerhard; Marino, Stephen A; Garty, Guy; Harken, Andrew; Brenner, David J

    2015-09-11

    A novel neutron irradiation facility at the Radiological Research Accelerator Facility (RARAF) has been developed to mimic the neutron radiation from an Improvised Nuclear Device (IND) at relevant distances (e.g. 1.5 km) from the epicenter. The neutron spectrum of this IND-like neutron irradiator was designed according to estimations of the Hiroshima neutron spectrum at 1.5 km. It is significantly different from a standard reactor fission spectrum, because the spectrum changes as the neutrons are transported through air, and it is dominated by neutron energies from 100 keV up to 9 MeV. To verify such wide energy range neutron spectrum, detailed here is the development of a combined spectroscopy system. Both a liquid scintillator detector and a gas proportional counter were used for the recoil spectra measurements, with the individual response functions estimated from a series of Monte Carlo simulations. These normalized individual response functions were formed into a single response matrix for the unfolding process. Several accelerator-based quasi-monoenergetic neutron source spectra were measured and unfolded to test this spectroscopy system. These reference neutrons were produced from two reactions: T(p,n)(3)He and D(d,n)(3)He, generating neutron energies in the range between 0.2 and 8 MeV. The unfolded quasi-monoenergetic neutron spectra indicated that the detection system can provide good neutron spectroscopy results in this energy range. A broad-energy neutron spectrum from the (9)Be(d,n) reaction using a 5 MeV deuteron beam, measured at 60 degrees to the incident beam was measured and unfolded with the evaluated response matrix. The unfolded broad neutron spectrum is comparable with published time-of-flight results. Finally, the pair of detectors were used to measure the neutron spectrum generated at the RARAF IND-like neutron facility and a comparison is made to the neutron spectrum of Hiroshima.

  19. Opportunities for Polarized He-3 in RHIC and EIC

    Energy Technology Data Exchange (ETDEWEB)

    Aschenauer E.; Deshpande, A.; Fischer, W.; Derbenev, S.; Milner, R.; Roser, T.; Zelenski, A.

    2011-10-01

    The workshop on opportunities for polarized He-3 in RHIC and EIC was targeted at finding practical ways of implementing and using polarized He-3 beams. Polarized He-3 beams will provide the unique opportunity for first measurements, i.e, to a full quark flavor separation measuring single spin asymmetries for p{sup +}, p{sup -} and p{sup 0} in hadron-hadron collisions. In electron ion collisions the combination of data recorded with polarized electron proton/He-3 beams allows to determine the quark flavor separated helicity and transverse momentum distributions. The workshop had sessions on polarized He-3 sources, the physics of colliding polarized He-3 beams, polarimetry, and beam acceleration in the AGS Booster, AGS, RHIC, and ELIC. The material presented at the workshop will allow making plans for the implementation of polarized He-3 beams in RHIC.

  20. Development of NRESP98 Monte Carlo codes for the calculation of neutron response functions of neutron detectors. Calculation of the response function of spherical BF{sub 3} proportional counter

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, M.; Saito, K.; Ando, H. [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1998-05-01

    The method to calculate the response function of spherical BF{sub 3} proportional counter, which is commonly used as neutron dose rate meter and neutron spectrometer with multi moderator system, is developed. As the calculation code for evaluating the response function, the existing code series NRESP, the Monte Carlo code for the calculation of response function of neutron detectors, is selected. However, the application scope of the existing NRESP is restricted, the NRESP98 is tuned as generally applicable code, with expansion of the geometrical condition, the applicable element, etc. The NRESP98 is tested with the response function of the spherical BF{sub 3} proportional counter. Including the effect of the distribution of amplification factor, the detailed evaluation of the charged particle transportation and the effect of the statistical distribution, the result of NRESP98 calculation fit the experience within {+-}10%. (author)

  1. Strategy for D/He-3 fusion development

    Science.gov (United States)

    Santarius, John F.

    1988-01-01

    It is concluded that Deuterium/Helium-3 fusion faces a more difficult physics development path but an easier technology development path than does Deuterium/Tritium. Early D/He-3 tests in next generation D/T fusion experiments might provide a valuable D/He-3 proof-of-principle at modest cost. At least one high leverage alternate concept should be vigorously pursued. Space applications of D/He-3 fusion are critically important to large scale development.

  2. Synergism of He-3 acquisition with lunar base evolution

    Science.gov (United States)

    Crabb, Thomas M.; Jacobs, Mark K.

    1988-09-01

    It is shown how acquisition of He-3 affects Lunar Base development and operation. A four phase evolutionary Lunar Base scenario is summarized with initial equipment mass and resupply requirements. Requirements for various He-3 mining operations are shown and available by-products are identified. Impacts of mining He-3 on Lunar Base development include increases in equipment masses to be delivered to the lunar surface and a reduction of Lunar Base resupply based on availability of He-3 acquisition by-products. It is concluded that the acquisition of this valuable fusion fuel element greatly enhances the commercial potential of a Lunar Base.

  3. The cosmic-ray He-3/He-4 ratio from 200 MeV per nucleon(-1) to 3.7 GeV per nucleon(-1)

    DEFF Research Database (Denmark)

    Reimer, O.; Menn, W.; Hof, M.

    1998-01-01

    of the charge, the velocity, and the rigidity of cosmic rays using plastic scintillators, a high-resolution time-of-flight system, and two silica-aerogel Cerenkov counters in conjunction with a drift chamber/multiwire proportional chamber tracking system. About 75,000 helium isotopes are identified......The abundances of cosmic-ray helium isotopes between 0.2 and 3.7 GeV nucleon(-1) were measured by the Isotope Matter Antimatter Experiment (IMAX) during a flight from Lynn Lake, Manitoba, Canada on 1992 July 16-17. The IMAX balloon-borne magnetic spectrometer realized a direct measurement...... by their mass using the velocity versus magnetic rigidity technique. The measured He-3/He-4 ratios are corrected to the top of the atmosphere, and a comparison with previous data is given. The observed isotopic composition is found to be generally consistent with the predictions of a standard leaky box model...

  4. A dual-detector extended range rem-counter

    CERN Document Server

    Ferrarini, M; Silari, M; Agosteo, S

    2010-01-01

    The design and characterization of a dual-detector spherical rem counter is discussed in this paper. The rem counter is based on a polythene sphere with lead and cadmium insets, designed to host at its centre either an active (He-3 SP9 proportional counter) or a passive (CR39 + B-10 radiator) thermal neutron detector. Its sensitivity ranges from thermal energies up to 1 GeV. A Monte Carlo characterization of this dual-detector rem counter has shown no significant change in the shape of the response curve obtained with the two detectors. The rem counter has been calibrated with a Pu-Be source. An intercomparison in a high-energy neutron field has been carried out at the CERF facility at CERN among the rem counter in the two configurations, two commercial units and the original version of the active LINUS in use at CERN. Both the active and passive versions of the rem counter agree, within the statistical uncertainties, with the CERN LINUS and with the facility reference values. Both versions of the instrument ...

  5. Large Area X-Ray Proportional Counter (LAXPC) Instrument on AstroSat and Some Preliminary Results from its Performance in the Orbit

    Indian Academy of Sciences (India)

    P. C. Agrawal; J. S. Yadav; H. M. Antia; Dhiraj Dedhia; P. Shah; Jai Verdhan Chauhan; R. K. Manchanda; V. R. Chitnis; V. M. Gujar; Tilak Katoch; V. N. Kurhade; P. Madhwani; T. K. Manojkumar; V. A. Nikam; A. S. Pandya; J. V. Parmar; D. M. Pawar; Jayashree Roy; B. Paul; Mayukh Pahari; Ranjeev Misra; M. H. Ravichandran; K. Anilkumar; C. C. Joseph; K. H. Navalgund; R. Pandiyan; K. S. Sarma; K. Subbarao

    2017-06-01

    Large area X-ray propositional counter (LAXPC) instrument on AstroSat is aimed at providing high time resolution X-ray observations in 3–80 keV energy band with moderate energy resolution. To achieve large collecting area, a cluster of three co-aligned identical LAXPC detectors, is used to realize an effective area in access of ∼6000cm2 at 15 keV. The large detection volume of the LAXPC detectors, filled with xenon gas at ∼2 atmosphere pressure, results in detection efficiency greater than 50%, above 30 keV. In this article, we present salient features of the LAXPC detectors, their testing and characterization in the laboratory prior to launch and calibration in the orbit. Some preliminary results on timing and spectral characteristics of a few X-ray binaries and other type of sources, are briefly discussed to demonstrate that the LAXPC instrument is performing as planned in the orbit.

  6. K-He3 and K+K- interactions in the pd→ He3 K+K- reaction

    Science.gov (United States)

    Grishina, V. Yu.; Büscher, M.; Kondratyuk, L. A.

    2007-01-01

    We investigate the K- He3 and K+K- interactions in the reaction pd→ He3 K+K- near threshold and compare our model calculations with data from the MOMO experiment at COSY-Jülich. A large attractive effective K-p amplitude would give a significant K- He3 final-state interaction effect, which is not supported by the experimental data. We also estimate upper limits for the a0(980) and f0(980) contributions to the produced K+K- pairs.

  7. Proportionality lost - proportionality regained?

    DEFF Research Database (Denmark)

    Werlauff, Erik

    2010-01-01

    In recent years, the European Court of Justice (the ECJ) seems to have accepted restrictions on the freedom of establishment and other basic freedoms, despite the fact that a more thorough proportionality test would have revealed that the restriction in question did not pass the 'rule of reason' ...

  8. Ion cyclotron range of frequency mode conversion flow drive in D(He-3) plasmas on JET

    NARCIS (Netherlands)

    Lin, Y.; Mantica, P.; Hellsten, T.; Kiptily, V.; Lerche, E.; Nave, M. F. F.; Rice, J. E.; Van Eester, D.; de Vries, P. C.; Felton, R.; Giroud, C.; Tala, T.

    2012-01-01

    Ion cyclotron range of frequency (ICRF) mode conversion has been shown to drive toroidal flow in JET D(He-3) L-mode plasmas: B-t0 = 3.45 T, n(e0) similar to 3x10(19) m(-3), I-p = 2.8 and 1.8 MA, P-RF <= 3MW at 33MHz and -90 degrees phasing. Central toroidal rotation in the counter-I-p directi

  9. Comparisons of LET Distributions for Protons with Energies between50 and 200 MeV Determined Using a Spherical Tissue-EquivalentProportional Counter (TEPC) and a Position-Sensitive Silicon Spectrometer(RRMD-III)

    Energy Technology Data Exchange (ETDEWEB)

    Borak, Thomas B.; Doke, Tadayoshi; Fuse, T.; Guetersloh, StephenB.; Heilbronn, Lawrence H.; Hara, K.; Moyers, Michael; Suzuki, S.; Taddei, Phillip; Terasawa, K.; Zeitlin, Cary J.

    2004-12-01

    Experiments have been performed to measure the response of a spherical tissue-equivalent proportional counter (TEPC) and a silicon-based LET spectrometer (RRMD-III) to protons with energies ranging from 50 200 MeV. This represents a large portion of the energy distribution for trapped protons encountered by astronauts in low-Earth orbit. The beam energies were obtained using plastic polycarbonate degraders with a monoenergetic beam that was extracted from a proton synchrotron. The LET spectrometer provided excellent agreement with the expected LET distribution emerging from the energy degraders. The TEPC cannot measure the LET distribution directly. However, the frequency mean value of lineal energy, y bar f, provided a good approximation to LET. This is in contrast to previous results for high-energy heavy ions wherey barf underestimated LET, whereas the dose-averaged lineal energy, y barD, provided a good approximation to LET.

  10. Energy requirements for HE-3 mining operations on the Moon

    Science.gov (United States)

    Kulcinski, Gerald L.

    At the present rate of world energy consumption (10 TW-y/y) and allowing for an equilibrium consumption of 20 to 30 TW-y/y in mid 21st century, we will exhaust economically recoverable fossil fuels in the next 50 to 60 years. We will then have to rely on nuclear (fission and fusion) and renewable energy to feed, warm, and protect the world's population. Fusion energy is expected to play an important role in the 21st century and there a 2 billion dollar per year research program to commercialize that energy resource. A serious problem with this is its reliance on the D-T fuel cycle which releases 80 percent of its energy in the form of neutrons. These neutrons cause significant radiation damage and induce large amounts of radioactivity. There is another fusion fuel cycle involving the isotopes of Deuterium and Helium-3 which, if configured properly, releases 1 percent or less of its energy in neutrons. Obviously, such a fuel would be preferred, but there is no large source of He-3 known to satisfy world energy needs. Fortunately, a very large source of He-3 was found on the Moon, implanted over the past 4 billion years by the solar wind. Recent analysis of Apollo and Luna data reveals that over a million tons of He-3 sit on the Moon's surface. The potential energy in this He-3 fuel is 10 times that contained in all the coal, oil, and natural gas on the Earth. The purpose of this paper is to examine the energy required to extract the He-3 from the lunar regolith.

  11. Microscopic Description of Diffractive Deuteron Breakup by He-3 Nuclei

    CERN Document Server

    Kovalchuk, Valery

    2016-01-01

    A microscopic formalism for describing observed cross sections for deuteron breakup by three-nucleon nuclei was developed on the basis of the diffraction nuclear model. A general formula that describes the amplitude for the reaction d+3He->3He+p+n and which involves only one adjustable parameter was obtained by using expansions of the integrands involved in terms of a Gaussian basis. This formula was used to analyze experimental data on the exclusive cross sections for deuteron breakup by He-3 nuclei at the projectile energy of 89.4 MeV. The importance of employing, in calculations, a deuteron wave function that has a correct asymptotic behavior at large nucleon-nucleon distances was demonstrated.

  12. Single shot demountable self-contained He-3 refrigerator

    Science.gov (United States)

    Kittel, P.; Brooks, W. F.

    1982-01-01

    The present investigation is concerned with the development of a self-contained demountable He-3 refrigerator which greatly increases the versatility of a cold-plate-style helium Dewar. The refrigerator is controlled by a single heater. The considered design makes it possible to achieve a temperature of 0.27 K without costly or time-consuming modifications to the Dewar. An example for an employment of a temperature of less than 1 K in space is related to the study of the critical behavior of He-3/He-4 mixtures in the absence of gravitational mixing. This requires a temperature of 0.87 K. Such low temperatures can also be utilized in the space operation of infrared telescopes. Attention is given to details of system design, the operating principles, and aspects of performance.

  13. Hard Two-Body Photodisintegration of He3

    Science.gov (United States)

    Pomerantz, I.; Ilieva, Y.; Gilman, R.; Higinbotham, D. W.; Piasetzky, E.; Strauch, S.; Adhikari, K. P.; Aghasyan, M.; Allada, K.; Amaryan, M. J.; Anefalos Pereira, S.; Anghinolfi, M.; Baghdasaryan, H.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Batourine, V.; Beck, A.; Beck, S.; Bedlinskiy, I.; Berman, B. L.; Biselli, A. S.; Boeglin, W.; Bono, J.; Bookwalter, C.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Bubis, N.; Burkert, V.; Camsonne, A.; Canan, M.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Chirapatpimol, K.; Cisbani, E.; Cole, P. L.; Contalbrigo, M.; Crede, V.; Cusanno, F.; D'Angelo, A.; Daniel, A.; Dashyan, N.; de Jager, C. W.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G. E.; Doughty, D.; Dupre, R.; Dutta, C.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fleming, J. A.; Fradi, A.; Garibaldi, F.; Geagla, O.; Gevorgyan, N.; Giovanetti, K. L.; Girod, F. X.; Glister, J.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Harrison, N.; Heddle, D.; Hicks, K.; Ho, D.; Holtrop, M.; Hyde, C. E.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jiang, X.; Jo, H. S.; Joo, K.; Katramatou, A. T.; Keller, D.; Khandaker, M.; Khetarpal, P.; Khrosinkova, E.; Kim, A.; Kim, W.; Klein, F. J.; Koirala, S.; Kubarovsky, A.; Kubarovsky, V.; Kuleshov, S. V.; Kvaltine, N. D.; Lee, B.; LeRose, J. J.; Lewis, S.; Lindgren, R.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Mao, Y.; Martinez, D.; Mayer, M.; McCullough, E.; McKinnon, B.; Meekins, D.; Meyer, C. A.; Michaels, R.; Mineeva, T.; Mirazita, M.; Moffit, B.; Mokeev, V.; Montgomery, R. A.; Moutarde, H.; Munevar, E.; Munoz Camacho, C.; Nadel-Turonski, P.; Nasseripour, R.; Nepali, C. S.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Pappalardo, L. L.; Paremuzyan, R.; Park, K.; Park, S.; Petratos, G. G.; Phelps, E.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Procureur, S.; Protopopescu, D.; Puckett, A. J. R.; Qian, X.; Qiang, Y.; Ricco, G.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rodriguez, I.; Ron, G.; Rosner, G.; Rossi, P.; Sabatié, F.; Saha, A.; Saini, M. S.; Sarty, A. J.; Sawatzky, B.; Saylor, N. A.; Schott, D.; Schulte, E.; Schumacher, R. A.; Seder, E.; Seraydaryan, H.; Shneor, R.; Smith, G. D.; Sokhan, D.; Sparveris, N.; Stepanyan, S. S.; Stepanyan, S.; Stoler, P.; Subedi, R.; Sulkosky, V.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tkachenko, S.; Ungaro, M.; Vernarsky, B.; Vineyard, M. F.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Wang, Y.; Watts, D. P.; Weinstein, L. B.; Weygand, D. P.; Wojtsekhowski, B.; Wood, M. H.; Yan, X.; Yao, H.; Zachariou, N.; Zhan, X.; Zhang, J.; Zhao, Z. W.; Zheng, X.; Zonta, I.

    2013-06-01

    We have measured cross sections for the γHe3→pd reaction at photon energies of 0.4-1.4 GeV and a center-of-mass angle of 90°. We observe dimensional scaling above 0.7 GeV at this center-of-mass angle. This is the first observation of dimensional scaling in the photodisintegration of a nucleus heavier than the deuteron.

  14. Portable He-3 detector cryostat for the far infrared

    Science.gov (United States)

    Radostitz, J. V.; Nolt, I. G.; Kittel, P.; Donnelly, R. J.

    1978-01-01

    The design of a portable He-3 cryostat for far infrared detection applications is described, with a cutaway drawing of the cryostat, including bolometer and cooled optics, provided. Consideration is given to the selection and testing of various bolometer materials, including Ge:Ga and Ge:InSb; the resistance-temperature coefficients of the materials examined are presented. The absolute flux calibration of the detector system using a new temperature-modulated cold source method is described.

  15. Results of experiments devoted to searches for 2 K capture on 78Kr and for the double-beta decay of 136Xe with the aid of proportional counters

    Science.gov (United States)

    Gavrilyuk, Yu. M.; Gangapshev, A. M.; Zhantudueva, Dj. A.; Kazalov, V. V.; Kuz'minov, V. V.; Panasenko, S. I.; Ratkevich, S. S.; Efendiev, K. V.; Yakimenko, S. P.

    2013-09-01

    A brief description of two low-background setups deployed at the Baksan Neutrino Observatory (Institute for Nuclear Research, Russian Academy of Sciences) and intended for searches for two types of double-beta decay of inert-gas isotopes—2 K capture on 78Kr and the double-beta decay of 136Xe—is given. The two setups in question have similar structures and employ identical large high-pressure copper proportional counters as detectors. Upon a treatment of data from measurements with krypton samples differing in the content of the isotope 78Kr, the spectrum for an enriched sample revealed an excess of events at a statistical-significance level of about two standard deviations (2 σ). If one attributes this excess to 2 K(2 ν) capture on 78Kr, the respective half-life is T 1/2 = 1.4{-0.7/+2.3} × 1022 yr at a 90% C.L. A treatment of data from measurements with xenon samples differing in content of the isotope 136Xe led to the appearance of an excess of events in the spectrum for an enriched sample at a statistical-significance level of about 2.2 σ. If one assumes that this excess is due to the two-neutrino double-beta decay of 136Xe, then the respective half-life is T 1/2 = 5.8{-1.8/+4.7} × 1021 yr.

  16. The n,{gamma} discrimination in recoil-proton proportional counters. Application to the measurement of fast neutron spectra; Discrimination n,{gamma} dans les compteurs proportionnels a protons de recul. Application a la mesure des spectres de neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

    Jeandidier, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    A description is given of a spectrometry chain working in the energy range of a few keV to 1 MeV, and designed for measurement of fast neutron spectra. It consists of detectors, recoil proton proportional counters built especially for this work by R. COMTE (DEG/SER) and which make it possible to cover the energy range and also associated electronic equipment. A brief description is first given of the physical processes involved: (n,p) collisions in the gas, influence of {gamma} radiation; the method of discrimination is then presented. It is based on the difference in the rise-times of the pulses. In the experiments described here the use of a bi-parametric system made it possible to employ the most simple discrimination device, based on the fact that the high frequency gamma pulse components are, at a given energy, weaker than those of the neutron pulses. Results are given of measurements carried out on the Van der Graaff (mono-energetic neutrons for testing the linearity of the chain and the resolving power of the counters), and of those made in a sub-critical system Hug at Cadarache. (author) [French] On decrit une chaine de spectrometrie travaillant dans le domaine d'energie de quelques keV a 1 MeV destinee a la mesure des spectres de neutrons rapides. Elle comprend les detecteurs, compteurs proportionnels a protons de recul, realises specialement pour cette etude par M. R. COMTE (DEG/SER), permettant de couvrir la gamme d'energie et l'electronique associee. Apres un rappel des processus physiques mis en jeu: chocs (n,p) dans les gaz, influence des rayonnements {gamma}, on expose la methode de discrimination utilisee. Celle-ci est basee sur la difference des temps de montee des impulsions. Au cours des experiences rapportees ici, la mise en oeuvre d'un ensemble bi-parametrique a permis d'utiliser le dispositif de discrimination le plus simple, base sur la remarque que les composantes a haute frequence des impulsions {gamma} sont, a

  17. 大面积气体闪烁正比计数器的研制及性能测试%Developement and Performance Testing of Large Surface Gas Scintillation Proportional Counter

    Institute of Scientific and Technical Information of China (English)

    骆志平; 庞洪超; 刘阳; 黄金峰; 王莹; 熊文俊

    2016-01-01

    本工作建立了一套有效探测面积大于300 cm2的气体闪烁正比计数器系统,并利用波长转换材料实现了普通光电倍增管对光信号的收集。对该系统进行了系列性能测试,测试结果表明,探测器对109 Cd 22.6 keV X射线具有7.5%的能量分辨率,点源距探测器3.2 cm时达到12.4%的探测效率。本工作的研究成果将为核污染场所低能X、γ放射性样品测量及超铀核素人体内照射污染测量等提供一种有力手段。%In this work ,a gas scintillation proportional counter (GSPC) with effective detection area of 300 cm2 was built .The wavelength shifting material was used to couple the photomultiplier and scintillator to achieve the light collection . The performance testing was done to test the detector .The result shows that the energy resolution for 109Cd 22.6 keV X ray is 7.5% ,and the total detection efficiency is 12.4% when the source‐detector separation distance is 3.2 cm .The detector studied in this work could be used to measure the low energy X and γ radioactive sample in radiation contaminated facilities ,and to measure the internal intake activity of transuranium elements .

  18. Proportional reasoning

    DEFF Research Database (Denmark)

    Dole, Shelley; Hilton, Annette; Hilton, Geoff

    2015-01-01

    Proportional reasoning is widely acknowledged as a key to success in school mathematics, yet students’ continual difficulties with proportion-related tasks are well documented. This paper draws on a large research study that aimed to support 4th to 9th grade teachers to design and implement tasks...... to foster students’ proportional reasoning. Classroom data revealed limited initial teacher knowledge and awareness of the pervasive nature of proportional reasoning required in the mathematics curriculum. Teacher capacity to seize teachable moments for building students’ proportional reasoning skills...... increased throughout the project. From this background, this paper presents an analysis of the proportional reasoning demands and opportunities of topics within the school mathematics curriculum in Australia. Implications for the study of whole number arithmetic (WNA) and other topics to promote...

  19. Proportional reasoning

    DEFF Research Database (Denmark)

    Dole, Shelley; Hilton, Annette; Hilton, Geoff

    2015-01-01

    to foster students’ proportional reasoning. Classroom data revealed limited initial teacher knowledge and awareness of the pervasive nature of proportional reasoning required in the mathematics curriculum. Teacher capacity to seize teachable moments for building students’ proportional reasoning skills......Proportional reasoning is widely acknowledged as a key to success in school mathematics, yet students’ continual difficulties with proportion-related tasks are well documented. This paper draws on a large research study that aimed to support 4th to 9th grade teachers to design and implement tasks...... increased throughout the project. From this background, this paper presents an analysis of the proportional reasoning demands and opportunities of topics within the school mathematics curriculum in Australia. Implications for the study of whole number arithmetic (WNA) and other topics to promote...

  20. Collimated Outflows in the Stingray Nebula (He 3-1357)

    Science.gov (United States)

    Bobrowsky, M.; Sahu, K. C.; Parthasarathy, M.; Garcia-Lario, P.

    1997-12-01

    Observations over the past four decades have revealed significant changes in the spectrum of the Stingray Nebula (He 3-1357). Here we present HST images and spectra showing the most recent developments. In 1950, Henize saw only Hα in emission; but more recent observations by Parthasarathy et al. in 1992 showed strong forbidden lines consistent with a young planetary nebula. The spherically aberrated 1992 HST images, in which Bobrowsky first optically resolved the nebula, showed a compact nebula surrounding the central star. Nebular gas appeared most strongly concentrated in an ellipse with its major axis subtending 1.('') 6 from NE to SW. If this ellipse is actually a circular ring viewed obliquely, then our line of sight is inclined from the symmetry axis by 56deg . Above and below the ring of gas are two bubbles containing lower-density gas. At the tip of each bubble, there is a hole where the gas inside the bubbles has broken through and is now escaping. While images of focused jets have been obtained previously (Borkowski et al.), this is the first case where the nebular structure responsible for the focusing of an outflow can be clearly seen. The windblown appearance of the nebula is consistent with the blueshifted Si IV (1394-1403 Angstroms) and Al III (1855-1863 Angstroms) doublets observed by Parthasarathy et al. that indicated the presence of a strong stellar wind. The N V (1239-1243 Angstroms) to C IV (1548-1551 Angstroms) ratio has increased in recent years, consistent with a young nebula becoming increasingly ionized. Our new spectra reveal additional developments that show the real-time development of this young nebula. Finally, the new HST Planetary Camera images of the nebula show detailed structure indicating a much more complex object than previously known, including the presence of a companion star 0.('') from the central star.

  1. 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.

  2. Abundance of He-3 and other solar-wind-derived volatiles in lunar soil

    Science.gov (United States)

    Swindle, Timothy D.

    Volatiles implanted into the lunar regolith by the solar wind are potentially important lunar resources. Wittenberg et al. (1986) have proposed that lunar He-3 could be used as a fuel for terrestrial nuclear fusion reactors. They argue that a fusion scheme involving D and He-3 would be cleaner and more efficient than currently-proposed schemes involving D and T. However, since the terrestrial inventory of He-3 is so small, they suggest that the lunar regolith, with concentrations of the order of parts per billion (by mass) would be an economical source of He-3. Solar-wind implantation is also the primary source of H, C, and N in lunar soil. These elements could also be important, particularly for life support and for propellant production. In a SERC study of the feasibility of obtaining the necessary amount of He-3, Swindle et al. (1990) concluded that the available amount is sufficient for early reactors, at least, but that the mining problems, while not necessarily insurmountable, are prodigious. The volatiles H, C, and N, on the other hand, come in parts per million level abundances. The differences in abundances mean that (1) a comparable amount of H, C, and/or N could be extracted with orders of magnitude smaller operations than required for He-3, and (2) if He-3 extraction ever becomes important, huge quantities of H, C, and N will be produced as by-products.

  3. Discoloration and mineralization of Reactive Red HE-3B by heterogeneous photo-Fenton reaction.

    Science.gov (United States)

    Feng, Jiyun; Hu, Xijun; Yue, Po Lock; Zhu, Huai Yong; Lu, Gao Qing

    2003-09-01

    Discoloration and mineralization of Reactive Red HE-3B were studied by using a laponite clay-based Fe nanocomposite (Fe-Lap-RD) as a heterogeneous catalyst in the presence of H2O2 and UV light. Our experimental results clearly indicate that Fe-Lap-RD mainly consists of Fe2O3 (meghemite) and Fe2Si4O10(OH)2 (iron silicate hydroxide) which have tetragonal and monoclinic structures, respectively, and has a high specific surface area (472 m2/g) as well as a high total pore volume (0.547 cm3/g). It was observed that discoloration of HE-3B undergoes a much faster kinetics than mineralization of HE-3B. It was also found that initial HE-3B concentration, H2O2 concentration, UV light wavelength and power, and Fe-Lap-RD catalyst loading are the four main factors that can significantly influence the mineralization of HE-3B. At optimal conditions, complete discoloration of 100 mg/L HE-3B can be achieved in 30 min and the total organic carbon removal ratio can attain 76% in 120 min, illustrating that Fe-Lap-RD has a high photo-catalytic activity in the photo-assisted discoloration and mineralization of HE-3B in the presence of UV light (254 nm) and H2O2.

  4. Assessment of lunar sources of He-3 for use on earth

    Science.gov (United States)

    English, Robert E.

    1988-09-01

    As a gross measure of the economics of mining lunar sources of He-3, the energy densities (GJ/ton) of lunar soils were compared with the energy densities of various existing and future terrestrial sources of energy. On this basis, only the very richest lunar ores appear competitive with coal. Future lunar exploration might emphasize identification of lunar soils having higher concentrations of He-3.

  5. Accretion of Interplanetary Dust: A New Record from He-3 In Polar Ice Cores

    Science.gov (United States)

    Brook, Edward

    2002-01-01

    This grant funded measurements of extraterrestrial He-3 in particles extracted from polar ice samples. The overall objective was to develop measurements of He-3 as tracers of the flux of interplanetary dust particles (IDP's) to the earth. To our knowledge these are the first such measurements, apart from our earlier work. The project also funded an EPO activity - a climate and global change workshop for high school science teachers.

  6. Solar energetic particle event with He-3/He-4 greater than 1

    Science.gov (United States)

    Balasubrahmanyan, V. K.; Serlemitsos, A. T.

    1974-01-01

    An unusual solar event involving the detection of a He-3/He-4 ratio of about 1.5 was observed with the aid of the cosmic-ray telescopes of OGO-V on May 28, 1969. A theory dealing with the production of H-2, H-3, and He-3 in solar events is considered together with the conditions which would have to be satisfied in order to explain the observed very high helium isotope ratio in terms of the theory.

  7. Solar neon abundances from gamma-ray spectroscopy and He-3-rich particle events

    Science.gov (United States)

    Reames, D. V.; Ramaty, R.; Von Rosenvinge, T. T.

    1988-01-01

    Ambient solar atmospheric abundances derived from gamma-ray spectroscopy are compared with observations of solar energetic particles. Agreement is found between the gamma-ray-derived Ne/O ratio and the corresponding mean ratio for He-3-rich flares. Both of these values are significantly higher than inferred coronal Ne/O ratios. It is suggested that the mean Ne/O ratio in He-3-rich flares reflects the composition of the flare plasma rather than the acceleration process.

  8. Explore the possibility of accelerating polarized He-3 beam in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Bai M.; Courant, E.; Fischer, W.; Ptitsyn, V.; Roser, T.

    2012-05-20

    As the world's first high energy polarized proton collider, RHIC has made significant progresses in measuring the proton spin structure in the past decade. In order to have better understanding of the contribution of up quarks and down quarks to the proton spin structure, collisions of high energy polarized neutron beams are required. Polarized He-3 beams offer an effectiveway to provide polarized neutron beams. In this paper, we present studies of accelerating polarized He-3 in RHIC with the current dual snake configuration. Possibilities of adding two more pairs of snakes for accelerating polarized He-3 were explored. Results of six snake configuration in RHIC are also reported in the paper.

  9. SPIN-ISOSPIN EXCITATIONS IN NUCLEI VIA (HE-3,T) REACTIONS AT 450 MEV

    NARCIS (Netherlands)

    FUJIWARA, M; AKIMUNE, H; DAITO, [No Value; EJIRI, H; FUJITA, Y; GREENFIELD, MB; HARAKEH, MN; HAZAMA, R; INOMATA, T; JANECKE, J; KUDOMI, N; KUME, K; NAKAYAMA, S; SHINMYO, K; TAMII, A; TANAKA, M; TOYOKAWA, H; YOSOI, M

    1994-01-01

    Spin-isospin excitations in nuclei havee been studied by means of the (He-3, t) reactions at 450 MeV. The Gamow-Teller (GT) resonances are found to be strongly excited. A fine structure of the giant Gamow Teller resonances in medium-heavy nuclei is observed with an energy resolution of 130 keV. The

  10. Apatite 4He/3He and (U-Th)/He evidence for an ancient Grand Canyon.

    Science.gov (United States)

    Flowers, R M; Farley, K A

    2012-12-21

    The Grand Canyon is one of the most dramatic features on Earth, yet when and why it was carved have been controversial topics for more than 150 years. Here, we present apatite (4)He/(3)He thermochronometry data from the Grand Canyon basement that tightly constrain the near-surface cooling history associated with canyon incision. (4)He/(3)He spectra for eastern Grand Canyon apatites of differing He date, radiation damage, and U-Th zonation yield a self-consistent cooling history that substantially validates the He diffusion kinetic model applied here. Similar data for the western Grand Canyon provide evidence that it was excavated to within a few hundred meters of modern depths by ~70 million years ago (Ma), in contrast to the conventional model in which the entire canyon was carved since 5 to 6 Ma.

  11. Acquisition of He3 Cryostat Insert for Experiments on Topological Insulators

    Science.gov (United States)

    2016-02-03

    facilitated transport experiments on topological insulators and Dirac and Weyl semimetals. These experiments resulted in several notable achievements and...Approved for Public Release; Distribution Unlimited Final Report: Acquisition of He3 Cryostat Insert for Experiments on Topological Insulators. The views...P.O. Box 12211 Research Triangle Park , NC 27709-2211 Cryogenic equipment with 9 Tesla magnet, low temperature experiments REPORT DOCUMENTATION PAGE

  12. Population inversion mechanisms producing nuclear lasing in He-3-Ar, Xe, Kr, Cl, and UF6

    Science.gov (United States)

    Deyoung, R. J.; Wilson, J. W.

    1979-01-01

    The paper examines the lasing excitation mechanisms of present nuclear lasers, with a view to developing more efficient, higher power nuclear lasers. Particular attention is given to volumetric nuclear discharges pumped by either the He-3(n, p)H-3 reaction or the U-235F6(n, ff)FF reaction. Insight gained from these laser systems will make it possible to determine the major excitation mechanisms and then to look for new gaseous laser systems where these excitation mechanisms dominate.

  13. The Ga-71(He-3, t) reaction and the low-energy neutrino response

    NARCIS (Netherlands)

    Frekers, D.; Ejiri, H.; Akimune, H.; Adachi, T.; Bilgier, B.; Brown, B. A.; Cleveland, B. T.; Fujita, H.; Fujita, Y.; Fujiwara, M.; Ganioglu, E.; Gavrin, V. N.; Grewe, E. -W.; Guess, C. J.; Harakeh, M. N.; Hatanaka, K.; Hodak, R.; Holl, M.; Iwamoto, C.; Khai, N. T.; Kozer, H. C.; Lennarz, A.; Okamoto, A.; Okamura, H.; Povinec, P. P.; Puppe, P.; Simkovic, F.; Susoy, G.; Suzuki, T.; Tamii, A.; Thies, J. H.; Van de Walle, J.; Zegers, R. G. T.

    2011-01-01

    A Ga-71(He-3,t)Ge-71 charge-exchange experiment was performed to extract with high precision the Gamow-Teller (GT) transition strengths to the three lowest-lying states in Ge-71, i.e., the ground state (1/2(-)), the 175 keV (5/2(-)) and the 500 key (3/2(-)) excited states. These are the relevant sta

  14. Distributed performance counters

    Science.gov (United States)

    Davis, Kristan D; Evans, Kahn C; Gara, Alan; Satterfield, David L

    2013-11-26

    A plurality of first performance counter modules is coupled to a plurality of processing cores. The plurality of first performance counter modules is operable to collect performance data associated with the plurality of processing cores respectively. A plurality of second performance counter modules are coupled to a plurality of L2 cache units, and the plurality of second performance counter modules are operable to collect performance data associated with the plurality of L2 cache units respectively. A central performance counter module may be operable to coordinate counter data from the plurality of first performance counter modules and the plurality of second performance modules, the a central performance counter module, the plurality of first performance counter modules, and the plurality of second performance counter modules connected by a daisy chain connection.

  15. Barshay-Temmer test for the 4He( overlined, 3He) 3H reaction

    Science.gov (United States)

    Bruno, M.; Cannata, F.; D'agostino, M.; Fiandri, M. L.; Herman, M.; Hofmann, H. M.; Vuaridel, B.; Grüebler, W.; König, V.; Schmelzbach, P. A.; Elsener, K.

    1989-09-01

    The mechanisms of isospin violation in the reaction 4He( overlined, 3He) 3H is studied, in the framework of a microscopic model. To describe realistically the intermediate 6Li nucleus and the fragment states we use the refined resonating group model (RRGM). A detailed analysis of the matrix elements responsible for the asymmetry of cross sections and vector analyzing powers is presented. The isospin violation is found typically of the order of 5-10% and arises mainly from coupling to intermediate "5 + 1" structures in a two-step mechanism. The agreement with the experimental data is fair.

  16. Nuclear structure corrections to the Lamb shift in μHe3+ and μ3H

    Science.gov (United States)

    Nevo Dinur, N.; Ji, C.; Bacca, S.; Barnea, N.

    2016-04-01

    Measuring the 2S-2P Lamb shift in a hydrogen-like muonic atom allows one to extract its nuclear charge radius with a high precision that is limited by the uncertainty in the nuclear structure corrections. The charge radius of the proton thus extracted was found to be 7σ away from the CODATA value, in what has become the yet unsolved "proton radius puzzle". Further experiments currently aim at the isotopes of hydrogen and helium: the precise extraction of their radii may provide a hint at the solution of the puzzle. We present the first ab initio calculation of nuclear structure corrections, including the nuclear polarization correction, to the 2S-2P transition in μHe3+ and μ3H, and assess solid theoretical error bars. Our predictions reduce the uncertainty in the nuclear structure corrections to the level of a few percent and will be instrumental to the on-going μHe3+ experiment. We also support the mirror μ3H system as a candidate for further probing of the nucleon polarizabilities and shedding more light on the puzzle.

  17. Communal action of microbial cultures for Red HE3B degradation.

    Science.gov (United States)

    Patil, P S; Phugare, S S; Jadhav, S B; Jadhav, J P

    2010-09-15

    The consortium PMB11 consisting of three bacterial species, originally isolated from dye contaminated soil was identified as Bacillus odysseyi SUK3, Morganella morganii SUK5 and Proteus sp. SUK7. The consortium possessed the ability to decolorize various textile dyes as well as mixtures of dyes. PMB11 could decolorize Red HE3B (50 mg l(-1)) with 99% of decolorization within 12 h in nutrient broth, while in mineral medium it could decolorize up to 97% within 24h. Induction in the activities of various oxidative and reductive enzymes indicates the involvement of these enzymes in decolorization. Biodegradation of the dye was monitored using UV-vis spectroscopy, HPLC and FTIR analysis. The Red HE3B degradation pathway was proposed by GC-MS analysis. Various metabolites formed after the degradation were identified as 2,5-diaminobenzene 6-aminotriazine, aniline 2-sulfate, aniline 3-sulfate, 2-amino 5-chlorotriazine and naphthalene. Phytotoxicity studies revealed that metabolites formed after degradation were significantly less toxic in nature.

  18. Exploiting Intrinsic Triangular Geometry in Relativistic He3+Au Collisions to Disentangle Medium Properties

    CERN Document Server

    Nagle, J L; Beckman, S; Koblesky, T; Koop, J Orjuela; McGlinchey, D; Romatschke, P; Carlson, J; Lynn, J; McCumber, M

    2013-01-01

    Recent results in d+Au and p+Pb collisions at RHIC and the LHC provide evidence for collective expansion and flow of the created medium. We propose a control set of experiments to directly compare particle emission patterns from p+Au, d+Au, and He3+Au or t+Au collisions at the same sqrt(sNN). Using Monte Carlo Glauber we find that a He3 or triton projectile, with a realistic wavefunction description, induces a significant intrinsic triangular shape to the initial medium and that, even with viscous damping, this survives into a significant third order flow moment v3. By comparing systems with one, two, and three initial hot spots, one can disentangle the effects from the initial spatial distribution of the deposited energy and viscous damping. These are key tools to answering the question of how small a droplet of matter is necessary to form a quark-gluon plasma described by nearly inviscid hydrodynamics.

  19. Counter-cryptanalysis

    NARCIS (Netherlands)

    Stevens, M.M.J.; Canetti, R.; Garay, J.A.

    2013-01-01

    We introduce \\emph{counter-cryptanalysis} as a new paradigm for strengthening weak cryptographic primitives against cryptanalytic attacks. Redesigning a weak primitive to more strongly resist cryptanalytic techniques will unavoidably break backwards compatibility. Instead, counter-cryptanalysis expl

  20. CEDAR counter (internal part)

    CERN Multimedia

    1976-01-01

    Here on the mounting bench. The counter is a differential Cerenkov, corrected for chromaticity, able to differentiate pions from kaons up to 350 GeV. Counters of this type were used in all SPS hadron beams.

  1. Statistical mechanics of dilute liquid mixtures of He3 in He4

    Science.gov (United States)

    Jackson, H. W.

    1982-01-01

    The Woo-Tan-Massey quantum-mechanical theory of dilute mixtures of He-3 in liquid He-4 is extended to incorporate superfluid flow. Then statistical-mechanical principles are employed to find explicit formulas for thermodyanmic and hydrodynamic properties of mixtures, such as internal energy, free energy, entropy, pressure, chemical potential, and normal-fluid and superfluid densities. This paper is the first in a planned series that applies methods originally developed for pure liquid He-4 to dilute mixtures as a means of establishing a comprehensive theory that includes a theoretical bridge between a microscopic description of the mixtures and a hydrodynamic two-fluid model. Ultimately effects of applied electric and magnetic fields on dilute solutions are also planned to be treated.

  2. Kinematics of 1200 km/s Jets in He 3-1475

    CERN Document Server

    Borkowski, K J

    2000-01-01

    Spectroscopic observations of a proto-planetary nebula He 3-1475 with the Space Telescope Imaging Spectrograph (STIS) reveal the kinematics of its high (1200 km/s) velocity jets. The jets are formed at a large (0.15 pc) distance from its central star by collimation of an asymmetric stellar wind in a pair of conical shocks seen in Wide Field Planetary Camera (WFPC2) images. The jets consist of several pairs of knots symmetrically distributed with respect to the central star, with most knots exhibiting a head-tail morphology. Large (up to 650 km/s) radial velocity gradients are seen within the knots on subarcsec scales, with velocities decreasing from the knot heads toward their trailing tails. These large velocity gradients are a sign of efficient deceleration of jets by a much slower bipolar outflow. The inclination angle of the bipolar outflow is equal to 50 degrees, based on Doppler shifts of the scattered stellar Halpha line. Its velocity is equal to 140 km/s at a distance of 0.23 pc from the star, and inc...

  3. Susceptibility Measurements Near the He-3 Liquid-Gas Critical Point

    Science.gov (United States)

    Barmatz, Martin; Zhong, Fang; Hahn, Inseob

    2000-01-01

    An experiment is now being developed to measure both the linear susceptibility and specific heat at constant volume near the liquid-gas critical point of He-3 in a microgravity environment. An electrostriction technique for measuring susceptibility will be described. Initial electrostriction measurements were performed on the ground along the critical isochore in a 0.5 mm high measurement cell filled to within 0.1 % of the critical density. These measurements agreed with the susceptibility determined from pressure-density measurements along isotherms. The critical temperature, T(sub c), determined separately from specific heat and susceptibility measurements was self-consistent. Susceptibility measurements in the range t = T/T(sub c) - 1 > 10(exp -4)were fit to Chi(sup *)(sub T) = Gamma(sup +)t(exp -lambda)(1 + Gamma(sup +)(sub 1)t(sup delta). Best fit parameters for the asymptotic amplitude Gamma(sup +) and the first Wegner amplitude Gamma(sup +)(sub 1) will be presented and compared to previous measurements.

  4. Small-angle electron-impact excitation of He 3^1D.

    Science.gov (United States)

    Bartschat, Klaus; Andersen, Nils

    2002-05-01

    With few exceptions, the angular momentum transfer L_⊥ in small-angle electron-impact excitation of atoms is found to be positive, independent of the collision energy, the transition, and even the target of interest. The origin of this strong propensity and its range of validity has been subject of many discussions (see [1] for details). A major violation was found in recent experimental work [2] on electron-impact excitation of the He 3^1D state. We further investigated this problem by analyzing results from various numerical models that differ in the number of coupled states included in a close-coupling expansion. We found that only the most sophisticated ``convergent close-coupling'' (CCC) and ``R-matrix with pseudo-states'' (RMPS) models could reproduce the experimental data. Surprising results were also obtained for the charge cloud representing the excited 3d-electron, e.g., cases where this cloud extends predominantly in a direction perpendicular (rather than parallel) to the collision plane. [1] N. Andersen and K. Bartschat, Polarization, Alignment, and Orientation in Atomic Collisions, Springer (New York, 2000). [2] D. Cvejanović, D.T. McLaughlin, and A. Crowe (2000), J. Phys. B 33, 3013.

  5. The transparent microstrip gas counter

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hiroyuki, E-mail: leo@q.t.u-tokyo.ac.j [University of Tokyo, Tokyo 113-8656 (Japan); Fujita, Kaoru; Fujiwara, Takeshi [University of Tokyo, Tokyo 113-8656 (Japan); Niko, Hisako; Guerard, Bruno [Institute of Max von Laue and Paul Langevin, BP 156, 38042 Grenoble, Cedex 9 (France); Fraga, Francisco [Departamento de Fisica, LIP-Coimbra, Universidade de Coimbra, 3000 Coimbra (Portugal); Iyomoto, Naoko [University of Tokyo, Tokyo 113-8656 (Japan)

    2010-11-01

    Conventional MSGCs are made of metal electrodes that might absorb or reflect optical photons. If the electrodes are made of transparent material like ITO, we could take advantage of optical readout. A gas scintillation proportional counter made of ITO MSGC is fabricated and tested where both optical and charge signals are obtained. We have selected a multi-grid structure that can avoid charge-up problem with normal transparent glass substrate. Test results with Ar and CF{sub 4} gas mixture showed a stable gas gain of {approx}2800 and {approx}110 optical photons for 6 keV X-rays. Position sensing with PSPMT has successfully been demonstrated.

  6. FLEXIBLE GEIGER COUNTER

    Science.gov (United States)

    Richter, H.G.; Gillespie, A.S. Jr.

    1963-11-12

    A flexible Geiger counter constructed from materials composed of vinyl chloride polymerized with plasticizers or co-polymers is presented. The counter can be made either by attaching short segments of corrugated plastic sleeving together, or by starting with a length of vacuum cleaner hose composed of the above materials. The anode is maintained substantially axial Within the sleeving or hose during tube flexing by means of polystyrene spacer disks or an easily assembled polyethylene flexible cage assembly. The cathode is a wire spiraled on the outside of the counter. The sleeving or hose is fitted with glass end-pieces or any other good insulator to maintain the anode wire taut and to admit a counting gas mixture into the counter. Having the cathode wire on the outside of the counter substantially eliminates the objectional sheath effect of prior counters and permits counting rates up to 300,000 counts per minute. (AEC)

  7. Countering Internet Extremism

    Science.gov (United States)

    2009-01-01

    literally examine hundreds of books and speeches. Since the purpose of this work is examining ways to counter an extremist’s Internet use of the...provide differing perspectives on how to counter extremist Internet use . A 2008 New York Times article indirectly offers some methods. Writers Eric...or scholars have the most potential to effectively counter extremist Internet use . Such efforts could help to stifle some of the issues that

  8. The Principle of Proportionality

    DEFF Research Database (Denmark)

    Bennedsen, Morten; Meisner Nielsen, Kasper

    2005-01-01

    Recent policy initiatives within the harmonization of European company laws have promoted a so-called "principle of proportionality" through proposals that regulate mechanisms opposing a proportional distribution of ownership and control. We scrutinize the foundation for these initiatives...... in relationship to the process of harmonization of the European capital markets.JEL classifications: G30, G32, G34 and G38Keywords: Ownership Structure, Dual Class Shares, Pyramids, EU companylaws....

  9. The Principle of Proportionality

    DEFF Research Database (Denmark)

    Bennedsen, Morten; Meisner Nielsen, Kasper

    2005-01-01

    Recent policy initiatives within the harmonization of European company laws have promoted a so-called "principle of proportionality" through proposals that regulate mechanisms opposing a proportional distribution of ownership and control. We scrutinize the foundation for these initiatives...... in relationship to the process of harmonization of the European capital markets.JEL classifications: G30, G32, G34 and G38Keywords: Ownership Structure, Dual Class Shares, Pyramids, EU companylaws....

  10. Adaptation through proportion

    Science.gov (United States)

    Xiong, Liyang; Shi, Wenjia; Tang, Chao

    2016-08-01

    Adaptation is a ubiquitous feature in biological sensory and signaling networks. It has been suggested that adaptive systems may follow certain simple design principles across diverse organisms, cells and pathways. One class of networks that can achieve adaptation utilizes an incoherent feedforward control, in which two parallel signaling branches exert opposite but proportional effects on the output at steady state. In this paper, we generalize this adaptation mechanism by establishing a steady-state proportionality relationship among a subset of nodes in a network. Adaptation can be achieved by using any two nodes in the sub-network to respectively regulate the output node positively and negatively. We focus on enzyme networks and first identify basic regulation motifs consisting of two and three nodes that can be used to build small networks with proportional relationships. Larger proportional networks can then be constructed modularly similar to LEGOs. Our method provides a general framework to construct and analyze a class of proportional and/or adaptation networks with arbitrary size, flexibility and versatile functional features.

  11. MRI of the lung using hyperpolarized He-3 at very low magnetic field (3 mT)

    CERN Document Server

    Bidinosti, C P; Tastevin, G; Vignaud, A; Nacher, P J

    2004-01-01

    Optical pumping of He-3 produces large (hyper) nuclear-spin polarizations independent of the magnetic resonance imaging (MRI) field strength. This allows lung MRI to be performed at reduced fields with many associated benefits, such as lower tissue susceptibility gradients and decreased power absorption rates. Here we present results of 2D imaging as well as accurate 1D gas diffusion mapping of the human lung using He-3 at very low field (3 mT). Furthermore, measurements of transverse relaxation in zero applied gradient are shown to accurately track pulmonary oxygen partial pressure, opening the way for novel imaging sequences.

  12. Anticoincidence scintillation counter

    CERN Multimedia

    1966-01-01

    This anticoincidence scintillation counter will be mounted in a hydrogen target vessel to be used in a measurement of the .beta. parameter in the .LAMBDA0. decay. The geometry of the counter optimizes light collection in the central part where a scintillation disk of variable thickness can be fitted.

  13. The first CEDAR counter

    CERN Multimedia

    1976-01-01

    The first differential Cerenkov counter with chromatic corrections (called CEDAR) successfully tested at the PS in July 75. These counters were used in the SPS hadronic beams for particle identification. Some of the eight photomultipliers can be seen: they receive the light reflected back through the annular diaphragm. René Maleyran stands on the left.

  14. Proportional Borda allocations.

    Science.gov (United States)

    Darmann, Andreas; Klamler, Christian

    2016-01-01

    In this paper we study the allocation of indivisible items among a group of agents, a problem which has received increased attention in recent years, especially in areas such as computer science and economics. A major fairness property in the fair division literature is proportionality, which is satisfied whenever each of the n agents receives at least [Formula: see text] of the value attached to the whole set of items. To simplify the determination of values of (sets of) items from ordinal rankings of the items, we use the Borda rule, a concept used extensively and well-known in voting theory. Although, in general, proportionality cannot be guaranteed, we show that, under certain assumptions, proportional allocations of indivisible items are possible and finding such allocations is computationally easy.

  15. Hulth$\\grave{e}$n potential models for $\\alpha−\\alpha$ and $\\alpha−He^3$ elastic scattering

    Indian Academy of Sciences (India)

    J BHOI; U LAHA

    2017-03-01

    Simple Hulth$\\grave{e}$n-type potential models are proposed to treat the $\\alpha−\\alpha$ and $\\alpha−He^3$ elastic scattering. The merit of our approach is examined by computing elastic scattering phases through the judicious use of the phase function method. Reasonable agreements in scattering phase shifts are obtained with the standard data.

  16. Hulthén potential models for α-α and α-He 3 elastic scattering

    Science.gov (United States)

    BHOI, J.; LAHA, U.

    2017-03-01

    Simple Hulthén-type potential models are proposed to treat the α- α and α {-} {He}3 elastic scattering. The merit of our approach is examined by computing elastic scattering phases through the judicious use of the phase function method. Reasonable agreements in scattering phase shifts are obtained with the standard data.

  17. Numerical simulations of heavy fermion systems. From He-3 bilayers to topological Kondo insulators

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Jan

    2015-03-27

    In this thesis the results of model calculations based on an extended Periodic Anderson Model are presented. The three particle ring exchange, which is the dominant magnetic exchange process in layered He-3, is included in the model. In addition, the model incorporates the constraint of no double occupancy by taking the limit of large local Coulomb repulsion. By means of Cellular DMFT, the model is investigated for a range of values of the chemical potential μ and inverse temperature β=1/T. The method is a cluster extension to the Dynamical Mean-Field Theory (DMFT), and allows to systematically include non-local correlations beyond the DMFT. The auxiliary cluster model is solved by a hybridization expansion CTQMC cluster solver, which provides unbiased, numerically exact results for the Green's function and other observables of interest. As a first step, the onset of Fermi liquid coherence is studied. At low enough temperature, the self-energy is found to exhibit a linear dependence on Matsubara frequency. Meanwhile, the spin susceptibility crossed over from a Curie-Weiss law to a Pauli law. The heavy fermion state appears at a characteristic coherence scale T{sub coh}. While the density is rather high for small filling, for larger filling T{sub coh} is increasingly suppressed. This involves a decreasing quasiparticle residue Z∝T{sub coh} and an enhanced mass renormalization m{sup *}/m∝T{sub coh}{sup -1}. Extrapolation leads to a critical filling, where the coherence scale is expected to vanish at a quantum critical point. At the same time, the effective mass diverges. This corresponds to a breakdown of the Kondo effect, which is responsible for the formation of quasiparticles, due to a vanishing of the effective hybridization between the layers. Cellular DMFT simulations are conducted for small clusters of size N{sub c}=2 and 3. Furthermore a simple two-band model for two-dimensional topological Kondo insulators is devised, which is based on a single

  18. A large Cerenkov counter

    CERN Multimedia

    1981-01-01

    The photo shows the vertex Cerenkov counter C0 back side (with 12 mirrors) of the NA9 experiment. On foreground are members of the team (CERN and Wuppertal Uni), Salvo .., Manfred Poetsch, ..., Jocelyn Thadome, Helmut Braun, Heiner Brueck.

  19. Counter-cryptanalysis

    NARCIS (Netherlands)

    M.M.J. Stevens (Marc); R. Canetti; J.A. Garay

    2013-01-01

    textabstractWe introduce \\emph{counter-cryptanalysis} as a new paradigm for strengthening weak cryptographic primitives against cryptanalytic attacks. Redesigning a weak primitive to more strongly resist cryptanalytic techniques will unavoidably break backwards compatibility. Instead,

  20. Comparison of a designed virtual counter with a real counter

    Science.gov (United States)

    Tektas, G.; Celiktas, C.

    2017-02-01

    A counter is a device which counts the incident pulses within a fixed time. In this work, a virtual counter was designed by developing a code by LabVIEW software. Generator signals were sent to the virtual counter via a National Instruments multifunction data acquisition device. Analog and PFI (Programmable Function Interface) inputs of the device was used for the process. A real counter was also used for comparison. Counts acquired from both counters in different time intervals were compared with each other. It was concluded from the obtained results that the developed virtual counter could be used as a real counter.

  1. The divine proportion

    CERN Document Server

    Huntley, H E

    1970-01-01

    Using simple mathematical formulas, most as basic as Pythagoras's theorem and requiring only a very limited knowledge of mathematics, Professor Huntley explores the fascinating relationship between geometry and aesthetics. Poetry, patterns like Pascal's triangle, philosophy, psychology, music, and dozens of simple mathematical figures are enlisted to show that the ""divine proportion"" or ""golden ratio"" is a feature of geometry and analysis which awakes answering echoes in the human psyche. When we judge a work of art aesthetically satisfying, according to his formulation, we are making it c

  2. Magnetic hysteresis of p(+) and He-3(2+) irradiated melt-textured YBa2Cu3O(7-delta)

    Science.gov (United States)

    Song, S. N.; Liu, J.; Chen, I. G.; Weinstein, Roy

    1992-01-01

    We have measured the magnetic hysteresis loops and temperature dependent trapped fields in melt-textured YBa2Cu3O(7-delta) samples before and after p(+) and He-3(2+) irradiation using a Hall effect magnetometer (HEM) as well as a commercial vibrating sample magnetometer (VSM). For proper He-3(2+) fluence, the critical current density may be enhanced by a factor of 10. Calculations based on various critical state models show that before the irradiation, the hysteresis loops can be well accounted for by a critical current density of a modified power law field dependence. After the irradiation, the best fit has been achieved by using an exponential form. Jc and its field dependence deduced from HEM hysteresis loops are in good agreement with those deduced from the VSM loops, suggesting that the Hall effect magnetometer can be conveniently used to characterize bulk high Tc oxide superconductors.

  3. Constant Proportion Portfolio Insurance

    DEFF Research Database (Denmark)

    Jessen, Cathrine

    2014-01-01

    Portfolio insurance, as practiced in 1987, consisted of trading between an underlying stock portfolio and cash, using option theory to place a floor on the value of the position, as if it included a protective put. Constant Proportion Portfolio Insurance (CPPI) is an option-free variation...... on the theme, originally proposed by Fischer Black. In CPPI, a financial institution guarantees a floor value for the “insured” portfolio and adjusts the stock/bond mix to produce a leveraged exposure to the risky assets, which depends on how far the portfolio value is above the floor. Plain-vanilla portfolio...... insurance largely died with the crash of 1987, but CPPI is still going strong. In the frictionless markets of finance theory, the issuer’s strategy to hedge its liability under the contract is clear, but in the real world with transactions costs and stochastic jump risk, the optimal strategy is less obvious...

  4. Treatment versus proportionality

    DEFF Research Database (Denmark)

    Sorensen, David Woodrow Mattson

    2010-01-01

    Persons suffering from mental illness, retardation or other disturbances who commit crimes in Denmark cannot be punished, but are instead sentenced to treatment. In the past, these sentences were always indeterminate, meaning that treatment regimens were only terminated when psychiatrists judged...... these persons no longer a danger to themselves or others. This practice was, however, severely criticized by advocates for the mentally ill in the late 1990s, since many of these treatment sentences lasted far longer than penal sentences given to mentally competent persons found guilty of similar crimes....... This critique, which hinges on proportionality, led to a change in the law on July 1, 2000, after which the length of treatment for non-serious-violent crimes was limited to a maximum of five years. This change was itself criticized by the Council of Medical Forensic Specialists, who argued that time of release...

  5. Treatment versus proportionality

    DEFF Research Database (Denmark)

    Sorensen, David Woodrow Mattson

    2010-01-01

    Persons suffering from mental illness, retardation or other disturbances who commit crimes in Denmark cannot be punished, but are instead sentenced to treatment. In the past, these sentences were always indeterminate, meaning that treatment regimens were only terminated when psychiatrists judged...... these persons no longer a danger to themselves or others. This practice was, however, severely criticized by advocates for the mentally ill in the late 1990s, since many of these treatment sentences lasted far longer than penal sentences given to mentally competent persons found guilty of similar crimes....... This critique, which hinges on proportionality, led to a change in the law on July 1, 2000, after which the length of treatment for non-serious-violent crimes was limited to a maximum of five years. This change was itself criticized by the Council of Medical Forensic Specialists, who argued that time of release...

  6. An efficient anticoincidence counter

    CERN Multimedia

    1977-01-01

    This scintillation counter (about 25 cm diameter) was prepared at CERN for an experiment at the Saclay 600 MeV electron linac studying molecular processes originated in liquid hydrogen by muons. The counter is meant to surround the target and detect charged particles emerging from the hydrogen. The experiment was a CERN-Saclay collaboration which used the linac so as to take advantage of the time structure of the electron beam(see CERN Courier Sep 1977 and J. Bardin et al. Phys. Lett. B104 (1981) 320)

  7. Is Helium-3 hype, hyperbole or a hopeful fuel for the future. [Lunar He-3 extraction/production for earth fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Mackowski, M.J.

    1989-08-01

    Sixty kilowatts of thermal power have been reached with deuterium/He-3 reaction on the JET reactor, and full scale study of the environmental impact of a tokamak D/He-3 reactor is now underway for NASA. He-3 is obtained from the decaying process undergone by tritium, but in nature, the source of He-3 is the sun. It is found in abundance in the lunar regolith. He-3 combines with deuterium in a fusion reaction generating very high amounts of energy, He-4 and protons. He-3 is economical; it could be moon mined and sold at a price comparable to oil. The energy released is roughly 70 percent efficient, and can be directly converted to electricity with solid-state converters. Also, reactors can be built cheaper, placed closer to cities, and maintained and decomissioned more easily than any other type of fission or fusion reactor, thus allowing faster commercialization and lower energy costs. He-3 is not very radioactive; however, the physics of its nuclear structure presents barriers to getting it to fuse. Other advantages of producing He-3 on the moon include obtaining gases necessary in moon colonies, and fuel for hydrogen rockets. Water, nickel and carbon-oxygen compounds can also be obtained that way.

  8. Production of plutonium tracers in Np-237 nuclear reactions with He-3-ions in the energy range from 26 to 60 MeV

    NARCIS (Netherlands)

    Aaltonen, J; Dendooven, P; Gromova, EA; Jakovlev, VA; Trzaska, WH

    1998-01-01

    Cross-sections for the reaction Np-237 + He-3 --> Pu-236,Pu-237,Pu-238 at He-3 bombarding energies from 26 to 60 MeV were measured. Thick-target yields, based on the measured and previously known cross-sections were constructed. The results are discussed and compared with Ether reactions leading to

  9. Geiger Counter Technique

    Science.gov (United States)

    1942-01-01

    is a Genco HIyvac and is backed by a single stage oil diffusion punp. The mercury well is emnloyed as a pump and mixing chamber, providing a means of...system, after first being puaped down, is filled to ovar-priees-e with Argan . re counter is then pullet off the ribber tubing a few dorps of ether are

  10. Neutron counter based on beryllium activation

    Energy Technology Data Exchange (ETDEWEB)

    Bienkowska, B.; Prokopowicz, R.; Kaczmarczyk, J.; Paducha, M. [Institute of Plasma Physics and Laser Microfusion (IPPLM), Hery 23, 01-497 Warsaw (Poland); Scholz, M.; Igielski, A. [Institute of Nuclear Physics PAS (IFJPAN), Radzikowskiego 152, 31-342 Krakow (Poland); Karpinski, L. [Faculty of Electrical Engineering, Rzeszow University of Technology, Pola 2, 35-959 Rzeszow (Poland); Pytel, K. [National Centre for Nuclear Research (NCBJ), Soltana 7, 05-400 Otwock - Swierk (Poland)

    2014-08-21

    The fusion reaction occurring in DD plasma is followed by emission of 2.45 MeV neutrons, which carry out information about fusion reaction rate and plasma parameters and properties as well. Neutron activation of beryllium has been chosen for detection of DD fusion neutrons. The cross-section for reaction {sup 9}Be(n, α){sup 6}He has a useful threshold near 1 MeV, which means that undesirable multiple-scattered neutrons do not undergo that reaction and therefore are not recorded. The product of the reaction, {sup 6}He, decays with half-life T{sub 1/2} = 0.807 s emitting β{sup −} particles which are easy to detect. Large area gas sealed proportional detector has been chosen as a counter of β–particles leaving activated beryllium plate. The plate with optimized dimensions adjoins the proportional counter entrance window. Such set-up is also equipped with appropriate electronic components and forms beryllium neutron activation counter. The neutron flux density on beryllium plate can be determined from the number of counts. The proper calibration procedure needs to be performed, therefore, to establish such relation. The measurements with the use of known β–source have been done. In order to determine the detector response function such experiment have been modeled by means of MCNP5–the Monte Carlo transport code. It allowed proper application of the results of transport calculations of β{sup −} particles emitted from radioactive {sup 6}He and reaching proportional detector active volume. In order to test the counter system and measuring procedure a number of experiments have been performed on PF devices. The experimental conditions have been simulated by means of MCNP5. The correctness of simulation outcome have been proved by measurements with known radioactive neutron source. The results of the DD fusion neutron measurements have been compared with other neutron diagnostics.

  11. Neutron counter based on beryllium activation

    Science.gov (United States)

    Bienkowska, B.; Prokopowicz, R.; Scholz, M.; Kaczmarczyk, J.; Igielski, A.; Karpinski, L.; Paducha, M.; Pytel, K.

    2014-08-01

    The fusion reaction occurring in DD plasma is followed by emission of 2.45 MeV neutrons, which carry out information about fusion reaction rate and plasma parameters and properties as well. Neutron activation of beryllium has been chosen for detection of DD fusion neutrons. The cross-section for reaction 9Be(n, α)6He has a useful threshold near 1 MeV, which means that undesirable multiple-scattered neutrons do not undergo that reaction and therefore are not recorded. The product of the reaction, 6He, decays with half-life T1/2 = 0.807 s emitting β- particles which are easy to detect. Large area gas sealed proportional detector has been chosen as a counter of β-particles leaving activated beryllium plate. The plate with optimized dimensions adjoins the proportional counter entrance window. Such set-up is also equipped with appropriate electronic components and forms beryllium neutron activation counter. The neutron flux density on beryllium plate can be determined from the number of counts. The proper calibration procedure needs to be performed, therefore, to establish such relation. The measurements with the use of known β-source have been done. In order to determine the detector response function such experiment have been modeled by means of MCNP5-the Monte Carlo transport code. It allowed proper application of the results of transport calculations of β- particles emitted from radioactive 6He and reaching proportional detector active volume. In order to test the counter system and measuring procedure a number of experiments have been performed on PF devices. The experimental conditions have been simulated by means of MCNP5. The correctness of simulation outcome have been proved by measurements with known radioactive neutron source. The results of the DD fusion neutron measurements have been compared with other neutron diagnostics.

  12. Observation of Scattering Resonances in the Penning Ionization of NH$_3$ by He($^3$S$_1$) at Low Collision Energies

    CERN Document Server

    Jankunas, Justin; Hapka, Michal; Osterwalder, Andreas

    2014-01-01

    A merged-beam study of the gas phase He($^3$S$_1$) + NH$_3$ Penning ionization reaction dynamics in the collision energy range 3.3 $\\mu$eV $<$ E $<$ 10 meV is presented. In this energy range the reaction rate is governed by long-range attraction. Shape resonances are observed at collision energies of 1.8 meV and 7.3 meV and are assigned to $\\ell$=15,16 and $\\ell$=20,21 partial waves, respectively. The experimental results are well reproduced by theoretical calculations with the short-range reaction probability $P_{sr}=0.035$.

  13. Measurement of Integrated Stokes Parameters for He 3 3p State Excited by Spin-Polarized Electrons

    Institute of Scientific and Technical Information of China (English)

    DING Hai-Bing; PANG Wen-Ning; LIU Yi-Bao; SHANG Ren-Cheng

    2005-01-01

    @@ Integrated Stokes parameters Pi (i = 1, 2, 3) for the He 3 3p → 2 3S1 (388.9nm) transition after excitation from the ground state to the 3 3 P state by a transversely spin-polarized electron beam are measured in near threshold energy region. The experimental results are presented. The linear-polarization P2 are consistent with zero over the incident energy range, providing evidence for the LS coupling mechanism of the 3 3P state. The measured circular polarization P3 are non-zero, indicating strong electron-electron exchange effects in the spin-polarized electron-atom collision process.

  14. Cosmic ray exposure dating with in situ produced cosmogenic He-3 - Results from young Hawaiian lava flows

    Science.gov (United States)

    Kurz, Mark D.; Colodner, Debra; Trull, Thomas W.; Moore, Richard B.; O'Brien, Keran

    1990-01-01

    Cosmogenic helium contents in a suite of Hawaiian radiocarbon-dated lava flows were measured to study the use of the production rate of spallation-produced cosmogenic He-3 as a surface exposure chronometer. Basalt samples from the Mauna Loa and Hualalai volcanoes were analyzed, showing that exposure-age dating is feasible in the 600-13000 year age range. The data suggest a present-day sea-level production rate in olivine of 125 + or - 30 atoms/g yr.

  15. Investigation on phase shifting for a 4 K Stirling pulse tube cryocooler with He-3 as working fluid

    Science.gov (United States)

    Qiu, L. M.; Han, L.; Zhi, X. Q.; Dietrich, M.; Gan, Z. H.; Thummes, G.

    2015-07-01

    He-3 is generally recognized for its ability to provide more excellent thermophysical performance than He-4, especially in the 4 K temperature range. However, this was not always the case in our preliminary experiments on a three-stage Stirling-type pulse tube cryocooler (SPTC). Our ongoing studies, as reported in this paper, demonstrate that the different working fluids also affect the performance through their phase shifting capability. This feature has been passed over in large part by researchers considering refrigerant substitution. Unlike previous theoretical analyses that focus primarily on regenerator losses, this report investigates the effects of the working fluid on the phase angle at the cold end in order to quantitatively reveal the relationship between the lowest attainable temperature and the cooling capacity. The analysis agrees well with our experimental results on a three-stage SPTC. While running with the operating parameters optimized for He-3, the lowest temperature of the SPTC decreased from 5.4 K down to 4.03 K. This is the lowest refrigeration temperature ever achieved with a three-stage SPTC.

  16. Countering rumors about contraceptives.

    Science.gov (United States)

    Del Rosario, M L

    1976-01-01

    Rumors are among the serious problems of the National Population Program today. The principles related to the origin of rumors, who starts rumors pertaining to family planning, and how they spread are outlined. The basic approach in countering rumors for the pill and IUD is diagrammed so that each potential rumor is countered by a medical or nonmedical/technical explanation. Strategies used by information-education-communication programs to prevent rumors such as the small group discussion, selection and training of motivators, and use of mass media are discussed. Rumors about family planning are counteracted not with the use of elaborate techniques but with clear and fairly simple reassurances supported by medical evidence and case histories.

  17. Electromagnetic shower counter

    CERN Multimedia

    1974-01-01

    The octogonal block of lead glass is observed by eight photomultiplier tubes. Four or five such counters, arranged in succession, are used on each arm of the bispectrometer in order to detect heavy particles of the same family as those recently observed at Brookhaven and SLAC. They provide a means of identifying electrons. The arrangement of eight lateral photomultiplier tubes offers an efficient means of collecting the photons produced in the showers and determining, with a high resolution, the energy of the incident electrons. The total width at half-height is less than 6.9% for electrons having an energy of 1 GeV.

  18. Introduction: Two Kinds of Proportion

    Directory of Open Access Journals (Sweden)

    Matthew A Cohen

    2014-06-01

    Full Text Available The subject of architectural proportional systems in the history of architecture, the topic of this special collection of essays in 'Architectural Histories', has long been characterized by a fundamental ambiguity: the word and concept of proportion simultaneously signify two unrelated and in some ways opposite meanings. Proportion can refer to ratios, or it can refer to architectural beauty. In this introduction to the papers that follow, Matthew A. Cohen proposes a simple clarification of this ambiguity as a framework for continued discussion of this subject: that whenever scholars use the word proportion, they specify whether they intend ‘proportion-as-ratio’ or ‘proportion-as-beauty’. The frequent blending of these meanings today, Cohen argues, is a survival of attitudes toward proportional systems in architecture that were prevalent as long ago as the early Renaissance. Cohen proposes an alternative to Rudolf Wittkower's paradigmatic ‘break-away’ theory of the history of proportional systems, according to which virtually everyone accepted proportional systems as sources of universal beauty in architecture until the mid-eighteenth century, and after that time virtually everyone believed that beauty and proportional systems were matters of individual preference. Rather than a long period respectful of tradition followed by a long period skeptical of it, Cohen argues, based in part on a new interpretation of Claude Perrault’s 1683 codification of the notion of positive beauty, that architects and others have always had access to two parallel strands of thought pertaining to proportional systems: a skeptical-pragmatic strand and a respectful-metaphysical strand. This new historical and historiographical interpretation of the problem of architectural proportional systems, and the new vocabulary with which to discuss it critically presented herein, helps to separate aesthetic from historical considerations.

  19. Quantum counter automata

    CERN Document Server

    Say, A C Cem

    2011-01-01

    The question of whether quantum real-time one-counter automata (rtQ1CAs) can outperform their probabilistic counterparts has been open for more than a decade. We provide an affirmative answer to this question, by demonstrating a non-context-free language that can be recognized with perfect soundness by a rtQ1CA. This is the first demonstration of the superiority of a quantum model to the corresponding classical one in the real-time case with an error bound less than 1. We also introduce a generalization of the rtQ1CA, the quantum one-way one-counter automaton (1Q1CA), and show that they too are superior to the corresponding family of probabilistic machines. For this purpose, we provide general definitions of these models that reflect the modern approach to the definition of quantum finite automata, and point out some problems with previous results. We identify several remaining open problems.

  20. Counter-Rotating Accretion Discs

    OpenAIRE

    Dyda, Sergei; Lovelace, Richard V. E.; Ustyugova, Galina V.; Romanova, Marina M.; Koldoba, Alexander V.

    2014-01-01

    Counter-rotating discs can arise from the accretion of a counter-rotating gas cloud onto the surface of an existing co-rotating disc or from the counter-rotating gas moving radially inward to the outer edge of an existing disc. At the interface, the two components mix to produce gas or plasma with zero net angular momentum which tends to free-fall towards the disc center. We discuss high-resolution axisymmetric hydrodynamic simulations of a viscous counter-rotating disc for cases where the tw...

  1. Proportioning of light weight concrete

    DEFF Research Database (Denmark)

    Palmus, Lars

    1996-01-01

    Development of a method to determine the proportions of the raw materials in light weight concrete made with leight expanded clay aggregate. The method is based on composite theory......Development of a method to determine the proportions of the raw materials in light weight concrete made with leight expanded clay aggregate. The method is based on composite theory...

  2. Proportioning of light weight concrete

    DEFF Research Database (Denmark)

    Palmus, Lars

    1996-01-01

    Development of a method to determine the proportions of the raw materials in light weight concrete made with leight expanded clay aggregate. The method is based on composite theory......Development of a method to determine the proportions of the raw materials in light weight concrete made with leight expanded clay aggregate. The method is based on composite theory...

  3. Proportional Reasoning as Essential Numeracy

    Science.gov (United States)

    Dole, Shelley; Hilton, Annette; Hilton, Geoff

    2015-01-01

    This paper reports an aspect of a large research and development project that aimed to promote middle years school teachers' understanding and awareness of the pervasiveness of proportional reasoning as integral to numeracy. Teacher survey data of proportional reasoning across the curriculum were mapped on to a rich model of numeracy. Results…

  4. Space and power efficient hybrid counters array

    Science.gov (United States)

    Gara, Alan G.; Salapura, Valentina

    2009-05-12

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  5. Counter-Learning under Oppression

    Science.gov (United States)

    Kucukaydin, Ilhan

    2010-01-01

    This qualitative study utilized the method of narrative analysis to explore the counter-learning process of an oppressed Kurdish woman from Turkey. Critical constructivism was utilized to analyze counter-learning; Frankfurt School-based Marcusian critical theory was used to analyze the sociopolitical context and its impact on the oppressed. Key…

  6. Proportional smile design using the recurring esthetic dental (red) proportion.

    Science.gov (United States)

    Ward, D H

    2001-01-01

    Dentists have needed an objective way in which to evaluate a smile. A method for determining the ideal size and position of the anterior teeth has been presented here. Use of the FIVE to evaluate the RED proportion and the width-to-height ratio, tempered with sound clinical judgment, gives pleasing and consistent results. With the diversity that exists in nature, rarely does the final result follow all the mathematical rules of proportional smile design. This approach may serve as a foundation on which to base initial smile design, however. When one begins to understand the relationship between beauty, mathematics, and the surrounding world, one begins to appreciate their interdependence.

  7. Introduction to Neutron Coincidence Counter Design Based on Boron-10

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2012-01-22

    The Department of Energy Office of Nonproliferation Policy (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is ultimately to design, build and demonstrate a boron-lined proportional tube based alternative system in the configuration of a coincidence counter. This report, providing background information for this project, is the deliverable under Task 1 of the project.

  8. Bayesian inference on proportional elections.

    Directory of Open Access Journals (Sweden)

    Gabriel Hideki Vatanabe Brunello

    Full Text Available Polls for majoritarian voting systems usually show estimates of the percentage of votes for each candidate. However, proportional vote systems do not necessarily guarantee the candidate with the most percentage of votes will be elected. Thus, traditional methods used in majoritarian elections cannot be applied on proportional elections. In this context, the purpose of this paper was to perform a Bayesian inference on proportional elections considering the Brazilian system of seats distribution. More specifically, a methodology to answer the probability that a given party will have representation on the chamber of deputies was developed. Inferences were made on a Bayesian scenario using the Monte Carlo simulation technique, and the developed methodology was applied on data from the Brazilian elections for Members of the Legislative Assembly and Federal Chamber of Deputies in 2010. A performance rate was also presented to evaluate the efficiency of the methodology. Calculations and simulations were carried out using the free R statistical software.

  9. Counter-driver shock tube

    Science.gov (United States)

    Tamba, T.; Nguyen, T. M.; Takeya, K.; Harasaki, T.; Iwakawa, A.; Sasoh, A.

    2015-11-01

    A "counter-driver" shock tube was developed. In this device, two counter drivers are actuated with an appropriate delay time to generate the interaction between a shock wave and a flow in the opposite direction which is induced by another shock wave. The conditions for the counter drivers can be set independently. Each driver is activated by a separate electrically controlled diaphragm rupture device, in which a pneumatic piston drives a rupture needle with a temporal jitter of better than 1.1 ms. Operation demonstrations were conducted to evaluate the practical performance.

  10. Simultaneous measurement of tritium and radiocarbon by ultra-low-background proportional counting.

    Science.gov (United States)

    Mace, Emily; Aalseth, Craig; Alexander, Tom; Back, Henning; Day, Anthony; Hoppe, Eric; Keillor, Martin; Moran, Jim; Overman, Cory; Panisko, Mark; Seifert, Allen

    2016-12-21

    Use of ultra-low-background capabilities at Pacific Northwest National Laboratory provide enhanced sensitivity for measurement of low-activity sources of tritium and radiocarbon using proportional counters. Tritium levels are nearly back to pre-nuclear test backgrounds (~2-8 TU in rainwater), which can complicate their dual measurement with radiocarbon due to overlap in the beta decay spectra. We present results of single-isotope proportional counter measurements used to analyze a dual-isotope methane sample synthesized from ~120mg of H2O and present sensitivity results.

  11. Social Justice and Proportional Reasoning

    Science.gov (United States)

    Simic-Muller, Ksenija

    2015-01-01

    Ratio and proportional reasoning tasks abound that have connections to real-world situations. Examples in this article demonstrate how textbook tasks can easily be transformed into authentic real-world problems that shed light on issues of equity and fairness, such as population growth and crime rates. A few ideas are presented on how teachers can…

  12. Proportional Reasoning with a Pyramid

    Science.gov (United States)

    Mamolo, Ami; Sinclair, Margaret; Whiteley, Walter J.

    2011-01-01

    Proportional reasoning pops up in math class in a variety of places, such as while making scaled drawings; finding equivalent fractions; converting units of measurement; comparing speeds, prices, and rates; and comparing lengths, areas, and volume. Students need to be exposed to a variety of representations to develop a sound understanding of this…

  13. Over-the-Counter Medicines

    Science.gov (United States)

    Over-the-counter (OTC) medicines are drugs you can buy without a prescription. Some OTC medicines relieve aches, pains ... Others help manage recurring problems, like migraines. In the United States, the Food and Drug Administration decides ...

  14. The cosmic-ray He-3/He-4 ratio from 200 MeV per nucleon(-1) to 3.7 GeV per nucleon(-1)

    DEFF Research Database (Denmark)

    Reimer, O.; Menn, W.; Hof, M.;

    1998-01-01

    by their mass using the velocity versus magnetic rigidity technique. The measured He-3/He-4 ratios are corrected to the top of the atmosphere, and a comparison with previous data is given. The observed isotopic composition is found to be generally consistent with the predictions of a standard leaky box model...

  15. Neutron decay of deep hole states and isobaric analog states in Sn-115 populated by the (He-3,alpha) reaction at 102 MeV

    NARCIS (Netherlands)

    Soderman, PO; Ringbom, A; Blomgren, J; Olsson, N; Nilsson, L; Bordewijk, JA; van't Hof, G; Hofstee, MA; van der Ploeg, H; van der Werf, SY; Krasznahorkay, A; Balanda, A; Chmielewska, D; Laurent, H

    2001-01-01

    Neutron decay of excited hole states and isobaric analog states (IAS) populated by the Sn-116(He-3,alpha) reaction at an energy of 102 MeV has been investigated. The alpha -particles were analysed in a magnetic spectrograph positioned at 1.4 degrees and detected with a multiwire drift chamber. Excit

  16. Precision evaluation of the Ga-71(nu(e),e(-)) solar neutrino capture rate from the (He-3,t) charge-exchange reaction

    NARCIS (Netherlands)

    Frekers, D.; Adachi, T.; Akimune, H.; Alanssari, M.; Brown, B. A.; Cleveland, B. T.; Ejiri, H.; Fujita, H.; Fujita, Y.; Fujiwara, M.; Gavrin, V. N.; Harakeh, M. N.; Hatanaka, K.; Holl, M.; Iwamoto, C.; Lennarz, A.; Okamoto, A.; Okamura, H.; Suzuki, T.; Tamii, A.

    2015-01-01

    A precision measurement of the Ga-71(He-3,t)Ge-71 charge-exchange reaction was performed. By using a rather complete set of theoretical form factors to describe the cross-section angular distributions over a large angular range, the Gamow-Teller strength distribution up to the effective neutron-sepa

  17. Discrimination of non-radiation backgrounds in the proportional counter of MARDS

    Science.gov (United States)

    Na, Liang; Xiaofeng, Guo; Fei, Luo; Fanhua, Hao; RenDe, Ze; Qingpei, Xiang; Chengsheng, Chu; Yongchun, Xiang; Zhaotong, Yan; Wei, Li

    2017-03-01

    The Movable 37Ar Rapid Detection System (MARDS) was developed by the Institute of Nuclear Physics and Chemistry of the China Academy of Engineering Physics in 2006 for on-site inspections under the Comprehensive Test Ban Treaty. It is a small and portable system that can quickly acquire data at suspected nuclear test sites. In this work, digital pulse shape discrimination (PSD) was used to process data from test samples to reduce electronic noise. The experimental results demonstrate that PSD combined with principal component analysis can classify and reject many noise sources. Thus, the threshold for the signal can be set low, expanding MARDS valid data acquisition capability, especially in very low-level and low-energy counting situations.

  18. A semi-microscopic derivation of gas gain formula for proportional counters

    Science.gov (United States)

    Mazed, D.; Baaliouamer, M.

    1999-11-01

    Using the microscopic definition of the Townsend coefficient and based on theoretical considerations related to the physical behaviour of electrons in gases in conjunction with a set of empirical results, a semi-microscopic formula of α/ N, the first Townsend coefficient to gas density ratio, is developed in the form α/N=KS exp[-(S 0/S) 1+m] , where S= E/ N is the electric field strength to gas density ratio, and K, S 0 and m (0≤m≤1) characterize the gaseous medium. It is shown that when m=0 the α/ N formula reduces to the product of the analytical forms suggested by Diethorn as well as Williams and Sara. Moreover, it is shown that Diethorn and Zastawny formulae are simply deduced, respectively, as the first- and the second-order expansions of the combined formula. Applicability of the obtained gas gain formula for different sets of experimental gas gain data bring out a good consistency of the proposed gas amplification model.

  19. Performance of microstrip proportional counters for x-ray astronomy on spectrum-roentgen-gamma

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Carl; BAHNSEN, A; Christensen, Finn Erland

    1991-01-01

    electrode material. The low energy detectors will be equipped with polyimide windows of 0.5 pm thickness, providing a high quantum efficiency even at 200 eV with an energy resolution comparable to that of solid state detectors. The MSPC is capable of operating at high counting rates (iO ph s1...

  20. Development of a honeycomb gas proportional counter array for photon multiplicity measurements in high multiplicity environment

    Indian Academy of Sciences (India)

    M S Ganti; M M Aggarwal; S K Badyal; V S Bhatia; S Chattopadhyay; A K Dubey; M R Majumdar; M S Ganti; A Kumar; T K Nayak; S Mahajan; D P Mahapatra; L K Mangotra; B Mohanty; S Pal; S C Phatak; B V K Potukuchi; R Raniwala; S Raniwala; N K Rao; R N Singaraju; Bikash Sinha; M D Trivedi; R J Veenhof; Y P Viyogi

    2003-05-01

    A novel gas-based detector using large arrays of honeycomb cells has been developed and tested for use as a pre-shower photon multiplicity detector (PMD) for STAR and ALICE experiments. The appropriate cell design was arrived at using GARFIELD simulations. Prototype chambers with cell dimensions corresponding to STAR and ALICE were fabricated and tested at CERN PS and SPS. The charged particle detection efficiency and the pre-shower characteristics have been studied using pion and electron beams.

  1. Investigation of a lithium foil multi-wire proportional counter for potential {sup 3}He replacement

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A., E-mail: knelson1@ksu.edu [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Bellinger, Steven L.; Montag, Benjamin W.; Neihart, James L.; Riedel, Todd A.; Schmidt, Aaron J.; McGregor, Douglas S. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)

    2012-03-21

    The recent shortage in the supply of {sup 3}He for neutron detection has caused a large surge in research for a viable replacement. {sup 6}Li has a large cross section for the absorption of thermal neutrons and emits two relatively short-ranged interaction products. Li foil can now be manufactured thin enough to allow both reaction products to escape the foil. Ten layers of natural Li foil were placed in a multi-wire continuous flow gas chamber with a single anode wire between each foil. Four different thicknesses, 30, 50, 75 and 120 {mu}m, were tested in a thermalized neutron beam. The intrinsic thermal neutron detection efficiencies of 10 layers of 30, 50, and 75 {mu}m thick Li foil were measured to be 8.1, 11.1, and 15.7 percent. The n/{gamma} ratio was found to be 1.25 Multiplication-Sign 10{sup 7} using a {sup 137}Cs gamma-ray source. Additionally, neutron response pulse-height spectra of the four foil thicknesses are presented and compare well to simulated response spectra. Theoretical calculations show that thermal neutron detection efficiencies above 70 percent are achievable using enriched {sup 6}Li foils for the same detector geometries.

  2. Disease proportions attributable to environment

    Directory of Open Access Journals (Sweden)

    Vineis Paolo

    2007-11-01

    Full Text Available Abstract Population disease proportions attributable to various causal agents are popular as they present a simplified view of the contribution of each agent to the disease load. However they are only summary figures that may be easily misinterpreted or over-interpreted even when the causal link between an exposure and an effect is well established. This commentary discusses several issues surrounding the estimation of attributable proportions, particularly with reference to environmental causes of cancers, and critically examines two recently published papers. These issues encompass potential biases as well as the very definition of environment and of environmental agent. The latter aspect is not just a semantic question but carries implications for the focus of preventive actions, whether centred on the material and social environment or on single individuals.

  3. Neutron pileup algorithms for multiplicity counters

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Sean M.; Stave, Sean; Lintereur, Azaree; Siciliano, Edward; Kouzes, Richard; Bliss, Mary

    2015-06-01

    Abstract The shortage of helium-3 (3He) has created a need to identify alternative neutron detection options for a variety of nuclear nonproliferation applications. One application that may be affected by 3He replacement technology is that of mass accountancy for safeguards, which utilizes coincidence and multiplicity counters to verify special nuclear material declarations. The use of neutron scintillation materials, such as LiF-ZnS sheets, as an alternative to 3He proportional tubes in multiplicity counters requires novel techniques for Pulse Shape Discrimination to distinguish between neutrons and gamma rays. These techniques must work under high count rates, as the maximum momentary rate for incoming neutrons from multiplicity events can be quite large. We have created a fast and accurate neutron discrimination algorithm based on time window filtering and signature comparison that can operate quickly on data with high degrees of gamma ray and neutron pileup. This algorithm is evaluated for its capability to separate signals as the pileup rate increases, and the possibility for implementation on fast hardware (e.g., FPGA hardware) for real-time operation is explored.

  4. Neutron pileup algorithms for multiplicity counters

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Sean M., E-mail: sean.robinson@pnnl.gov [Pacific Northwest National Laboratory, Seattle, WA 98109 (United States); Stave, Sean; Lintereur, Azaree; Siciliano, Edward; Kouzes, Richard; Bliss, Mary [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

    2015-06-01

    The shortage of helium-3 ({sup 3}He) has created a need to identify alternative neutron detection options for a variety of nuclear nonproliferation applications. One application that may be affected by {sup 3}He replacement technology is that of mass accountancy for safeguards, which utilizes coincidence and multiplicity counters to verify special nuclear material declarations. The use of neutron scintillation materials, such as LiF–ZnS sheets, as an alternative to {sup 3}He proportional tubes in multiplicity counters requires novel techniques for Pulse Shape Discrimination to distinguish between neutrons and gamma rays. These techniques must work under high count rates, as the maximum momentary rate for incoming neutrons from multiplicity events can be quite large. We have created a fast and accurate neutron discrimination algorithm based on time window filtering and signature comparison that can operate quickly on data with high degrees of gamma ray and neutron pileup. This algorithm is evaluated for its capability to separate signals as the pileup rate increases, and the possibility for implementation on fast hardware (e.g., FPGA hardware) for real-time operation is explored.

  5. Modelling of an IR scintillation counter

    CERN Document Server

    Fraga, M M F; Policarpo, Armando

    2000-01-01

    A systematic study of the excitation and de-excitation mechanisms in ternary gas mixtures Ar+CO sub 2 +N sub 2 is presented regarding the possibility of developing a proportional scintillation counter based on the detection of the infrared molecular emissions associated with the lowest vibrational states of molecules. The use of visible or near-infrared photons (lambda<1 mu m) for applications like imaging and quality control of microstructure detectors has been reported. In view of these applications we analyse the processes leading to near-infrared emissions in pure argon and give an estimation of the number of photons emitted per electron, at several pressures, as a function of the charge gain.

  6. The consequences of Israel's counter terrorism policy

    OpenAIRE

    Jansen, Pia Therese

    2008-01-01

    The main focus of this thesis is to examine Israel's counter terrorism methods and their consequences and to debate the effectiveness of Israel's counter terrorism policy. By stimulating a debate on these issues it is possible to identify a more effective counter terrorism policy. In order to examine Israel's counter terrorism methods, their consequences and effectiveness, it is necessary to first explore the overall concepts of terrorism and counter terrorism. Then, because...

  7. Photodetectors for scintillator proportionality measurement

    Energy Technology Data Exchange (ETDEWEB)

    Moses, William W. [Lawrence Berkeley National Laboratory (United States)], E-mail: wwmoses@lbl.gov; Choong, Woon-Seng [Lawrence Berkeley National Laboratory (United States); Hull, Giulia; Payne, Steve; Cherepy, Nerine; Valentine, John D. [Lawrence Livermore National Laboratory (United States)

    2009-10-21

    We evaluate photodetectors for use in a Compton Coincidence apparatus designed for measuring scintillator proportionality. There are many requirements placed on the photodetector in these systems, including active area, linearity, and the ability to accurately measure low light levels (which implies high quantum efficiency and high signal-to-noise ratio). Through a combination of measurement and Monte Carlo simulation, we evaluate a number of potential photodetectors, especially photomultiplier tubes and hybrid photodetectors. Of these, we find that the most promising devices available are photomultiplier tubes with high ({approx}50%) quantum efficiency, although hybrid photodetectors with high quantum efficiency would be preferable.

  8. Photodetectors for Scintillator Proportionality Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Moses, William W.; Choong, Woon-Seng; Hull, Giulia; Payne, Steve; Cherepy, Nerine; Valentine, J.D.

    2010-10-18

    We evaluate photodetectors for use in a Compton Coincidence apparatus designed for measuring scintillator proportionality. There are many requirements placed on the photodetector in these systems, including active area, linearity, and the ability to accurately measure low light levels (which implies high quantum efficiency and high signal-to-noise ratio). Through a combination of measurement and Monte Carlo simulation, we evaluate a number of potential photodetectors, especially photomultiplier tubes and hybrid photodetectors. Of these, we find that the most promising devices available are photomultiplier tubes with high ({approx}50%) quantum efficiency, although hybrid photodetectors with high quantum efficiency would be preferable.

  9. Statistical inference on mixing proportion

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper, the interval estimation and hypothesis testing of the mixing proportion in mixture distributions are considered. A statistical inferential method is proposed which is inspired by the generalized p-values and generalized pivotal quantity. In some situations, the true levels of the tests given in the paper are equal to nominal levels, and the true coverage of the interval estimation or confidence bounds is also equal to nominal one. In other situations, under mild conditions, the tests are consistent and the coverage of the interval estimations or the confidence bounds is asymptotically equal to nominal coverage. Meanwhile, some simulations are performed which show that our method is satisfactory.

  10. Low-Background Experiments with High Pressure Gas Scintillation Proportional Detector

    OpenAIRE

    Akimov, D.Yu.; Burenkov, A. A; Kuzichev, V. F.; Morgunov, V. L.; Solovov, V.N.

    1997-01-01

    A scintillation proportional counter with wavelength shifting fiber readout filled with Xe or Kr under a pressure of up to 20 atm is proposed for the low-background experiments on search for dark matter of the Universe and 2K-decay of 78 Kr.

  11. Evaluation of B10Plus+* proportional detectors for neutron coincidence counting

    Energy Technology Data Exchange (ETDEWEB)

    Beddingfield, David H.; Yoon, Seokryung [International Atomic Energy Agency, Vienna International Centre, PO Box 100, 1400 Vienna, (Austria)

    2015-07-01

    GE-Reuter-Stokes (GERS) has developed a new line of neutron proportional counters, the B10Plus+* proportional counter. The detector design is intended to serve as a cost-effective alternative to traditional {sup 3}He proportional counters in a variety of applications. The detector is a hybrid design 10B-lined tube optimized with the addition of a small quantity of 3He gas to improve the detector performance and efficiency. As a demonstration of the B10Plus+* detector, GERS has constructed a Uranium Neutron Collar (UNCL) system consisting of B-10Plus+* proportional counters. GERS has designed and built a demonstration UNCL system intended to match the performance of a Type-I UNCL design in Pressurized Water Reactor (PWR) geometry operating in thermal mode. GERS offered their system on loan to the International Atomic Energy Agency (IAEA) Safeguards Division of Technical and Scientific Services for an assessment of the detector technology and the demonstration system. We have characterized the demonstration UNCL system and compared its performance with a traditional Type-I UNCL design in regular use by the IAEA. This paper summarizes our findings and observations during the characterization and testing activity. (authors)

  12. First Measurement of the $^{3}He(^{3}He,2p) ^{4}He$ Cross Section down to the Lower Edge of the Solar Gamow Peak

    CERN Document Server

    Bonetti, R; Campajola, L; Corvisiero, P; D'Alessandro, A; Dessalvi, M; D'Onofrio, A; Fubini, A; Gervino, G; Gialanella, L; Greife, U; Guglielmetti, A; Gustavino, C; Imbriani, G; Junker, M; Prati, P; Roca, V; Rolfs, C; Romano, M; Schuemann, F; Strieder, F; Terrasi, F; Trautvetter, H P; Zavatarelli, S

    1999-01-01

    We give the LUNA results on the cross section measurement of a key reaction of the proton-proton chain strongly affecting the calculated neutrino luminosity from the Sun: He3+He3-->He4+2p. Due to the cosmic ray suppression provided by the Gran Sasso underground laboratory it has been possible to measure the cross section down to the lower edge of the solar Gamow peak, i.e. as low as 16.5 keV centre of mass energy. The data clearly show the cross section increase due to the electron screening effect but they do not exhibit any evidence for a narrow resonance suggested to explain the observed solar neutrino flux.

  13. Turbulent mixing condensation nucleus counter

    Science.gov (United States)

    Mavliev, Rashid

    The construction and operating principles of the Turbulent Mixing Condensation Nucleus Counter (TM CNC) are described. Estimations based on the semiempirical theory of turbulent jets and the classical theory of nucleation and growth show the possibility of detecting particles as small as 2.5 nm without the interference of homogeneous nucleation. This conclusion was confirmed experimentally during the International Workshop on Intercomparison of Condensation Nuclei and Aerosol Particle Counters (Vienna, Austria). Number concentration, measured by the Turbulent Mixing CNC and other participating instruments, is found to be essentially equal.

  14. Countering 21st Century Threats

    DEFF Research Database (Denmark)

    Scharling Pedersen, Peter; Pillai, Chad M.; Hun, Lee Jae

    2015-01-01

    ), Counter-Terrorism (CT), and Security and Stability Operations (SSO). • Establishing a construct that allows a strategic Whole-of-Government capacity for operations coordinated by joint interagency task forces. • Continue to developing the Global SOF network. • Increased intelligence sharing in areas...... to be addressed in order to successfully conduct IW. As result of researching the issues associated with developing a JIIM approach to IW, the paper makes the following recommendations: • Establishing universally accepted concepts and doctrines for IW, UW, Foreign Internal Defense (FID), Counter Insurgency (COIN...

  15. Constant Proportion Debt Obligations (CPDOs)

    DEFF Research Database (Denmark)

    Cont, Rama; Jessen, Cathrine

    2012-01-01

    be made arbitrarily small—and thus the credit rating arbitrarily high—by increasing leverage, but the ratings obtained strongly depend on assumptions on the credit environment (high spread or low spread). More importantly, CPDO loss distributions are found to exhibit a wide range of tail risk measures......Constant Proportion Debt Obligations (CPDOs) are structured credit derivatives that generate high coupon payments by dynamically leveraging a position in an underlying portfolio of investment-grade index default swaps. CPDO coupons and principal notes received high initial credit ratings from...... the major rating agencies, based on complex models for the joint transition of ratings and spreads for all names in the underlying portfolio. We propose a parsimonious model for analysing the performance of CPDO strategies using a top-down approach that captures the essential risk factors of the CPDO. Our...

  16. Statistical inference on mixing proportion

    Institute of Scientific and Technical Information of China (English)

    XU XingZhong; LIU Fang

    2008-01-01

    In this paper,the interval estimation and hypothesis testing of the mixing proportion in mixture distributions are considered.A statistical inferential method is proposed which is inspired by the generalized p-values and generalized pivotal quantity.In some situations,the true levels of the tests given in the paper are equal to nominal levels,and the true coverage of the interval estimation or confidence bounds is also equal to nominal one.In other situations,under mild conditions,the tests are consistent and the coverage of the interval estimations or the confidence bounds is asymptotically equal to nominal coverage.Meanwhile,some simulations axe performed which show that our method is satisfactory.

  17. Counter-Rotating Accretion Discs

    CERN Document Server

    Dyda, Sergei; Ustyugova, Galina V; Romanova, Marina M; Koldoba, Alexander V

    2014-01-01

    Counter-rotating discs can arise from the accretion of a counter-rotating gas cloud onto the surface of an existing co-rotating disc or from the counter-rotating gas moving radially inward to the outer edge of an existing disc. At the interface, the two components mix to produce gas or plasma with zero net angular momentum which tends to free-fall towards the disc center. We discuss high-resolution axisymmetric hydrodynamic simulations of a viscous counter-rotating disc for cases where the two components are vertically separated and radially separated. The viscosity is described by an isotropic $\\alpha-$viscosity including all terms in the viscous stress tensor. For the vertically separated components a shear layer forms between them. The middle of this layer free-falls to the disk center. The accretion rates are increased by factors $\\sim 10^2-10^4$ over that of a conventional disc rotating in one direction with the same viscosity. The vertical width of the shear layer and the accretion rate are strongly dep...

  18. The Eros of Counter Education

    Science.gov (United States)

    Luzon, Pinhas

    2016-01-01

    Erotic Counter Education (ECE) is the educational position of the late Ilan Gur-Ze'ev. In ECE Gur-Ze'ev combines two opposing positions in the philosophy of education, one teleological and anti-utopian, the other teleological and utopian. In light of this unique combination, I ask what mediates between these two poles and suggest that the answer…

  19. Proportional Reasoning: A Review of the Literature.

    Science.gov (United States)

    Tourniaire, Francoise; Pulos, Steven

    1985-01-01

    The literature on proportional reasoning is reviewed. After methodology is discussed, strategies used to solve proportion problems, variables that influence performance, and training studies are each considered. (MNS)

  20. Basic Research Needs for Countering Terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; Franz, D.; Resnick, G.; Jacobson, S.; Valdez, J.; Gourley, P.; Tadros, M.; Sigman, M.; Sailor, M.; Ramsey, M.; Smith, B.; Shea, K.; Hrbek, J.; Rodacy, P.; Tevault, D.; Edelstein, N.; Beitz, J.; Burns, C.; Choppin, G.; Clark, S.; Dietz, M.; Rogers, R.; Traina, S.; Baldwin, D.; Thurnauer, M.; Hall, G.; Newman, L.; Miller, D.; Kung, H.; Parkin, D.; Shuh, D.; Shaw, H.; Terminello, L.; Meisel, D.; Blake, D.; Buchanan, M.; Roberto, J.; Colson, S.; Carling, R.; Samara, G.; Sasaki, D.; Pianetta, P.; Faison, B.; Thomassen, D.; Fryberger, T.; Kiernan, G.; Kreisler, M.; Morgan, L.; Hicks, J.; Dehmer, J.; Kerr, L.; Smith, B.; Mays, J.; Clark, S.

    2002-03-01

    To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism.

  1. Counter-discourse in Zimbabwean literature

    NARCIS (Netherlands)

    Mangena, Tendai

    2015-01-01

    Counter-Discourse in Zimbabwean Literature is a study of specific aspects of counter-discursive Zimbabwean narratives in English. In discussing the selected texts, my thesis is based on Terdiman’s (1989) the postcolonial concept of counter-discourse. In Zimbabwean literature challenges to a dominant

  2. Lossy Counter Machines Decidability Cheat Sheet

    Science.gov (United States)

    Schnoebelen, Philippe

    Lossy counter machines (LCM's) are a variant of Minsky counter machines based on weak (or unreliable) counters in the sense that they can decrease nondeterministically and without notification. This model, introduced by R. Mayr [TCS 297:337-354 (2003)], is not yet very well known, even though it has already proven useful for establishing hardness results.

  3. Science Experimenter: Experimenting with a Geiger Counter.

    Science.gov (United States)

    Mims, Forrest M., III

    1992-01-01

    Describes the use of geiger counters for scientific investigations and experiments. Presents information about background radiation, its sources and detection. Describes how geiger counters work and other methods of radiation detection. Provides purchasing information for geiger counters, related computer software and equipment. (MCO)

  4. Counter-discourse in Zimbabwean literature

    NARCIS (Netherlands)

    Mangena, Tendai

    2015-01-01

    Counter-Discourse in Zimbabwean Literature is a study of specific aspects of counter-discursive Zimbabwean narratives in English. In discussing the selected texts, my thesis is based on Terdiman’s (1989) the postcolonial concept of counter-discourse. In Zimbabwean literature challenges to a dominant

  5. Counter-Rotation in Disk Galaxies

    CERN Document Server

    Corsini, E M

    2014-01-01

    Counter-rotating galaxies host two components rotating in opposite directions with respect to each other. The kinematic and morphological properties of lenticulars and spirals hosting counter-rotating components are reviewed. Statistics of the counter-rotating galaxies and analysis of their stellar populations provide constraints on the formation scenarios which include both environmental and internal processes.

  6. Counter support for WA35

    CERN Multimedia

    1977-01-01

    This assembly was equipped with 78 counters, each consisting of a lucite cone, to produce Cerenkov light, and a CsI scintillator plate of 3 mm thickness glued on the face of the cone. The experiment WA35 was set-up in the s1 beam (West Hall) by the Darmstadt-Heidelberg-Virginia-Warsaw Collaboration to measure angular distributions and multiplicities of pions and recoil protons produced by hadrons interacting in nuclei. (See Annual Report 1976 p. 39)

  7. Science role in countering terrorism

    Science.gov (United States)

    Showstack, Randy

    Geoscience expertise figures as a component of a new report on harnessing the U.S. science and technology community in the fight against terrorism.The National Research Council report, "Making the Nation Safer: The Role of Science and Technology in Countering Terrorism," proposes research agendas in a number of areas perceived to be vulnerable to terrorism. These areas include nuclear and radiological threats, toxic chemicals and explosive materials, information technology, energy systems, and cities and fixed infrastructure.

  8. Optimization of simultaneous tritium-radiocarbon internal gas proportional counting

    Science.gov (United States)

    Bonicalzi, R. M.; Aalseth, C. E.; Day, A. R.; Hoppe, E. W.; Mace, E. K.; Moran, J. J.; Overman, C. T.; Panisko, M. E.; Seifert, A.

    2016-03-01

    Specific environmental applications can benefit from dual tritium and radiocarbon measurements in a single compound. Assuming typical environmental levels, it is often the low tritium activity relative to the higher radiocarbon activity that limits the dual measurement. In this paper, we explore the parameter space for a combined tritium and radiocarbon measurement using a natural methane sample mixed with an argon fill gas in low-background proportional counters of a specific design. We present an optimized methane percentage, detector fill pressure, and analysis energy windows to maximize measurement sensitivity while minimizing count time. The final optimized method uses a 9-atm fill of P35 (35% methane, 65% argon), and a tritium analysis window from 1.5 to 10.3 keV, which stops short of the tritium beta decay endpoint energy of 18.6 keV. This method optimizes tritium-counting efficiency while minimizing radiocarbon beta-decay interference.

  9. Study of Interaction of Low-Energy Antiprotons with H$^{2}$,He$^{3}$,He$^{4}$,Ne-Nuclei Using a Streamer Chamber in Magnetic Field

    CERN Multimedia

    2002-01-01

    The aim of this experiment is the systematic study of the interaction between low-energy antiprotons and the H|2,~He|3,~He|4,~Ne-nuclei using a self shunted streamer chamber in a magnetic field exposed to the antiproton beam of the LEAR facility. The properties of the self shunted streamer chamber, which allows the use of the filling gas (hydrogen, helium, neon at a pressure of l~atm) as a target, permit to carry out experiments also in the very low-energy region. \\\\ \\\\ The experimental apparatus is suitable for a large programme of measurements. We plan to measure the @*H|2 cross section and the spectator momentum distributions at @* momenta lower than 250~MeV/c, where data are lacking. It is interesting to study for the first time the @*He|3 and @*He|4 interactions measuring the cross sections and the emitted particle distributions. Among other things the knowledge of the branching ratio of the @*He|4 annihilation channels clarifies some open cosmological questions. The study of the process of nuclear absor...

  10. Application of a He3Ne infrared laser source for detection of geometrical dimensions of cracks and scratches on finished surfaces of metals

    Science.gov (United States)

    Nazaryan, Nikolay; Campana, Claudio; Moslehpour, Saeid; Shetty, Devdas

    2013-12-01

    In this study, the authors addressed a new method of measurement for microscratches and cracks on finished metallic surfaces. The technology proposed here can be used in aviation, automobile, machine-tools, bearings, electrical and thermal devices (detection of electrical and thermal contact resistance), and many other industrial fields where finished surfaces have to be inspected for quality before use. The technology is based on the application of He3Ne laser optics. This measurement method allows for the inspection of geometrical parameters such as depth and width of scratches and cracks and consists of a low-energy He3Ne red laser beam (wavelength 633 nm) with a cross-section of 0.48 mm, beam expander with special designed slit, multi-axis stage with sample holder and CCD (charge-coupled device) visual detection system. Using experimental data, a mathematical algorithm was created in order to calculate the depths and widths of the scratches and cracks where the method of center of gravity (centroid) of the imaged area was used. The results showed a good correlation between the experimental and calculated values of the dimensions of the scratches. Future work will deal with the determination of the geometrical dimensions of microcracks.

  11. Solar-flare implanted He-4/He-3 and solar-proton-produced Ne and Ar concentration profiles preserved in lunar rock 61016

    Science.gov (United States)

    Rao, M. N.; Garrison, D. H.; Bogard, D. D.; Reedy, R. C.

    1993-01-01

    Depth profiles for Ne-21, Ne-22, and Ar-38 isotopes from oriented lunar rock 61016 are reported. Concentration profiles of cosmogenic GCR+SCR (Galactic cosmic ray and solar cosmic ray-produced) isotopes are determined, quantitatively resolving neon and argon produced by energetic solar flares from that produced by Galactic cosmic rays. The SCR component is resolved from the GCR component as a function of shielding, and excellent agreement is found between experimental SCR production profiles for the isotopes and theoretically calculated values. A characteristic SW He-4/He-3 ratio of 3450 +/- 81, representing energies down to as few keV/amu. In slightly deeper samples an SRF He-4/He-3 ratio of 3450 +/- 725 is found for He particles with E larger than about 1 MeV/amu. These results indicate that the isotopic composition of SF He, averaged over the long term, is energy-dependent. An implanted Ne-20/Ne-22 ratio of 12.4 is measured in unetched samples, representing E greater than 1 MeV/amu, and a ratio of 11.6 is inferred in the samples, representing E larger than about 5 MeV/amu.

  12. Pulse-Shape Discrimination for Low-Background Proportional Counting

    Science.gov (United States)

    Aalseth, Craig

    2011-10-01

    Digital pulse-shape discrimination (PSD) is used to improve measurement sensitivity for internal-source gas proportional counters. Because the design of these detectors can be physically simple, they are well-suited for low-background applications where the radiopurity of detector materials must be stringently controlled. After mitigating dominant backgrounds (cosmic rays, external gamma-rays, radioactivity in materials), remaining background events frequently do not arise from ionization of the proportional counter gas. Various PSD methods have exploited the resulting pulse-shape differences. More sophisticated methods can offer better discrimination but may lead to more difficult calibration between model and detector. Variations between modeled and experimental shapes can limit the discriminating power achieved. This work addresses this difficulty by generating a template shape from each individual sample measurement of interest, a ``self-calibrating'' template. Differences in event topology can also cause differences in pulse shape. In this work the temporal region analyzed is limited to maximize background discrimination while avoiding unwanted sensitivity to event topology. Low-background measurements of tritium, carbon-14, argon-37, and argon-39 are currently being developed at the Pacific Northwest National Laboratory with detectors employing radiopure materials developed for neutrinoless double-beta decay and dark matter searches. The application of self-calibrating template PSD to measurement of these radioisotopes, along with initial measurement results, is described. Applications such as nuclear treaty verification, elucidating the environmental carbon cycle, and the assay of low-background materials for next-generation nuclear physics experiments are presented.

  13. Cognitive and Metacognitive Aspects of Proportional Reasoning

    Science.gov (United States)

    Modestou, Modestina; Gagatsis, Athanasios

    2010-01-01

    In this study we attempt to propose a new model of proportional reasoning based both on bibliographical and research data. This is impelled with the help of three written tests involving analogical, proportional, and non-proportional situations that were administered to pupils from grade 7 to 9. The results suggest the existence of a…

  14. COUNTER-TERRORISM IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Jordan Sebastian Meliala

    2015-04-01

    Full Text Available Since the incident of World Trade Center (WTC in USA, Indonesia has become an easy target for the next terrorism. Counterterrorist campaigns can be undertaken by military and paramilitary forces. Counterterrorism refers to proactive policies that specifically seek to eliminate terrorist environments and groups, Regardless of which policy is selected, the ultimate goal of counterterrorism is clear: to save lives by proactively preventing or decreasing the number of terrorist attacks. But, so far the Government of Indonesia is only able to capture the terrorists but is unable to eradicate terrorism. Therefore, the government of Indonesia still needs a comprehensive ways to counter terrorism in Indonesia

  15. Condensation Particle Counter Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-01

    The Model 3772 CPC is a compact, rugged, and full-featured instrument that detects airborne particles down to 10 nm in diameter, at an aerosol flow rate of 1.0 lpm, over a concentration range from 0 to 1x104 #/cc. This CPC is ideally suited for applications without high concentration measurements, such as basic aerosol research, filter and air-cleaner testing, particle counter calibrations, environmental monitoring, mobile aerosol studies, particle shedding and component testing, and atmospheric and climate studies.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-04-21

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

  17. Simultaneous measurement of tritium and radiocarbon by ultra-low-background proportional counting

    Energy Technology Data Exchange (ETDEWEB)

    Mace, Emily; Aalseth, Craig; Alexander, Tom; Back, Henning; Day, Anthony; Hoppe, Eric; Keillor, Martin; Moran, Jim; Overman, Cory; Panisko, Mark; Seifert, Allen

    2017-08-01

    Use of ultra-low-background capabilities at Pacific Northwest National Laboratory provide enhanced sensitivity for measurement of low-activity sources of tritium and radiocarbon using proportional counters. Tritium levels are nearly back to pre-nuclear test backgrounds (~2-8 TU in rainwater), which can complicate their dual measurement with radiocarbon due to overlap in the isotope’s respective energy spectra. This activity makes direct dual-isotope measurements challenging without additional chemistry to concentrate the tritium in a sample. We present results of single-isotope proportional counter measurements used to analyze a dual-isotope methane sample synthesized from ~120 mg of H2O and present sensitivity results.

  18. Proportional valve with a piezoelectric actuator

    Science.gov (United States)

    Laski, Pawel Andrzej

    2016-11-01

    The article concerns a slotted proportional valve for use in pneumatic and hydraulic systems. There is a growing demand for both hydraulic and pneumatic ultrafast proportional valves. The conducted analysis of literature confirms the lack of such solutions for proportional valves. The currently used pneumatic systems for selection and segregation of parts and objects require ultrafast valves. The presented solution for the proportional valve can significantly improve and accelerate this type of technological processes. Furthermore, fast proportional valves can be successfully used for positional control of pneumatic and hydraulic drives. The article presents the design of a slotted divide valve and sets the maximum mass flow rate for service roads.

  19. Proportional valve with a piezoelectric actuator

    Directory of Open Access Journals (Sweden)

    Laski Pawel Andrzej

    2017-01-01

    Full Text Available The article concerns a slotted proportional valve for use in pneumatic and hydraulic systems. There is a growing demand for both hydraulic and pneumatic ultrafast proportional valves. The conducted analysis of literature confirms the lack of such solutions for proportional valves. The currently used pneumatic systems for selection and segregation of parts and objects require ultrafast valves. The presented solution for the proportional valve can significantly improve and accelerate this type of technological processes. Furthermore, fast proportional valves can be successfully used for positional control of pneumatic and hydraulic drives. The article presents the design of a slotted divide valve and sets the maximum mass flow rate for service roads.

  20. Optimal crossover designs for the proportional model

    OpenAIRE

    Zheng, Wei

    2013-01-01

    In crossover design experiments, the proportional model, where the carryover effects are proportional to their direct treatment effects, has draw attentions in recent years. We discover that the universally optimal design under the traditional model is E-optimal design under the proportional model. Moreover, we establish equivalence theorems of Kiefer-Wolfowitz's type for four popular optimality criteria, namely A, D, E and T (trace).

  1. On generating counter-rotating streamwise vortices

    KAUST Repository

    Winoto, S H

    2015-09-23

    Counter-rotating streamwise vortices are known to enhance the heat transfer rate from a surface and also to improve the aerodynamic performance of an aerofoil. In this paper, some methods to generate such counter-rotating vortices using different methods or physical conditions will be briefly considered and discussed.

  2. Proportional Reasoning and the Visually Impaired

    Science.gov (United States)

    Hilton, Geoff; Hilton, Annette; Dole, Shelley L.; Goos, Merrilyn; O'Brien, Mia

    2012-01-01

    Proportional reasoning is an important aspect of formal thinking that is acquired during the developmental years that approximate the middle years of schooling. Students who fail to acquire sound proportional reasoning often experience difficulties in subjects that require quantitative thinking, such as science, technology, engineering, and…

  3. Regulatory scrutiny of subsidiarity and proportionality

    NARCIS (Netherlands)

    Meuwese, Anne; Gomtsyan, Suren

    2015-01-01

    As the monitoring of the principles of subsidiarity and proportionality is mostly left up to the EU institutions, internal quality control bodies could play an important role in developing tests and standards which represent part of ‘subsidiarity and proportionality in action’. In this context, the

  4. CCSSM Challenge: Graphing Ratio and Proportion

    Science.gov (United States)

    Kastberg, Signe E.; D'Ambrosio, Beatriz S.; Lynch-Davis, Kathleen; Mintos, Alexia; Krawczyk, Kathryn

    2013-01-01

    A renewed emphasis was placed on ratio and proportional reasoning in the middle grades in the Common Core State Standards for Mathematics (CCSSM). The expectation for students includes the ability to not only compute and then compare and interpret the results of computations in context but also interpret ratios and proportions as they are…

  5. Relating arithmetical techniques of proportion to geometry

    DEFF Research Database (Denmark)

    Wijayanti, Dyana

    2015-01-01

    . Considering 6 common Indonesian textbooks in use, we describe how proportion is explained and appears in examples and exercises, using an explicit reference model of the mathematical organizations of both themes. We also identify how the proportion themes of the geometry and arithmetic domains are linked. Our...... results show that the explanation in two domains has different approach, but basically they are mathematically related....

  6. Counter traction makes endoscopic submucosal dissection easier.

    Science.gov (United States)

    Oyama, Tsuneo

    2012-11-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable counter traction thereby making ESD more efficient and safe. The author published this method in 2002. The name ESD was not established in those days; the name cutting endoscopic mucosal resection (EMR) or EMR with hook knife was used. The other traction methods such as external grasping forceps, internal traction, double channel scope, and double scopes method are introduced in this paper. A good strategy for creating counter traction makes ESD easier.

  7. Numerical Proportion Representation: A Neurocomputational Account.

    Science.gov (United States)

    Chen, Qi; Verguts, Tom

    2017-01-01

    Proportion representation is an emerging subdomain in numerical cognition. However, its nature and its correlation with simple number representation remain elusive, especially at the theoretical level. To fill this gap, we propose a gain-field model of proportion representation to shed light on the neural and computational basis of proportion representation. The model is based on two well-supported neuroscientific findings. The first, gain modulation, is a general mechanism for information integration in the brain; the second relevant finding is how simple quantity is neurally represented. Based on these principles, the model accounts for recent relevant proportion representation data at both behavioral and neural levels. The model further addresses two key computational problems for the cognitive processing of proportions: invariance and generalization. Finally, the model provides pointers for future empirical testing.

  8. The Omega Counter, a Frequency Counter Based on the Linear Regression

    CERN Document Server

    Rubiola, E; Bourgeois, P -Y; Vernotte, F

    2015-01-01

    This article introduces the {\\Omega} counter, a frequency counter -- or a frequency-to-digital converter, in a different jargon -- based on the Linear Regression (LR) algorithm on time stamps. We discuss the noise of the electronics. We derive the statistical properties of the {\\Omega} counter on rigorous mathematical basis, including the weighted measure and the frequency response. We describe an implementation based on a SoC, under test in our laboratory, and we compare the {\\Omega} counter to the traditional {\\Pi} and {\\Lambda} counters. The LR exhibits optimum rejection of white phase noise, superior to that of the {\\Pi} and {\\Lambda} counters. White noise is the major practical problem of wideband digital electronics, both in the instrument internal circuits and in the fast processes which we may want to measure. The {\\Omega} counter finds a natural application in the measurement of the Parabolic Variance, described in the companion article arXiv:1506.00687 [physics.data-an].

  9. Human skeleton proportions from monocular data

    Institute of Scientific and Technical Information of China (English)

    PENG En; LI Ling

    2006-01-01

    This paper introduces a novel method for estimating the skeleton proportions ofa human figure from monocular data.The proposed system will first automatically extract the key frames and recover the perspective camera model from the 2D data.The human skeleton proportions are then estimated from the key frames using the recovered camera model without posture reconstruction. The proposed method is tested to be simple, fast and produce satisfactory results for the input data. The human model with estimated proportions can be used in future research involving human body modeling or human motion reconstruction.

  10. Instability of counter-rotating stellar disks

    Science.gov (United States)

    Hohlfeld, R. G.; Lovelace, R. V. E.

    2015-09-01

    We use an N-body simulation, constructed using GADGET-2, to investigate an accretion flow onto an astrophysical disk that is in the opposite sense to the disk's rotation. In order to separate dynamics intrinsic to the counter-rotating flow from the impact of the flow onto the disk, we consider an initial condition in which the counter-rotating flow is in an annular region immediately exterior the main portion of the astrophysical disk. Such counter-rotating flows are seen in systems such as NGC 4826 (known as the "Evil Eye Galaxy"). Interaction between the rotating and counter-rotating components is due to two-stream instability in the boundary region. A multi-armed spiral density wave is excited in the astrophysical disk and a density distribution with high azimuthal mode number is excited in the counter-rotating flow. Density fluctuations in the counter-rotating flow aggregate into larger clumps and some of the material in the counter-rotating flow is scattered to large radii. Accretion flow processes such as this are increasingly seen to be of importance in the evolution of multi-component galactic disks.

  11. 21 CFR 866.2170 - Automated colony counter.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2170 Automated colony counter. (a) Identification. An automated colony counter is a mechanical device intended for...

  12. Proportionality, just war theory and weapons innovation.

    Science.gov (United States)

    Forge, John

    2009-03-01

    Just wars are supposed to be proportional responses to aggression: the costs of war must not greatly exceed the benefits. This proportionality principle raises a corresponding 'interpretation problem': what are the costs and benefits of war, how are they to be determined, and a 'measurement problem': how are costs and benefits to be balanced? And it raises a problem about scope: how far into the future do the states of affairs to be measured stretch? It is argued here that weapons innovation always introduces costs, and that these costs cannot be determined in advance of going to war. Three examples, the atomic bomb, the AK-47 and the ancient Greek catapult, are given as examples. It is therefore argued that the proportionality principle is inapplicable prospectively. Some replies to the argument are discussed and rejected. Some more general defences of the proportionality principle are considered and also rejected. Finally, the significance of the argument for Just War Theory as a whole is discussed.

  13. Taming Past LTL and Flat Counter Systems

    CERN Document Server

    Demri, Stéphane; sangnier, Arnaud

    2012-01-01

    Reachability and LTL model-checking problems for flat counter systems are known to be decidable but whereas the reachability problem can be shown in NP, the best known complexity upper bound for the latter problem is made of a tower of several exponentials. Herein, we show that the problem is only NP-complete even if LTL admits past-time operators and arithmetical constraints on counters. Actually, the NP upper bound is shown by adequately combining a new stuttering theorem for Past LTL and the property of small integer solutions for quantifier-free Presburger formulae. Other complexity results are proved, for instance for restricted classes of flat counter systems.

  14. GEIGER-MULLER TYPE COUNTER TUBE

    Science.gov (United States)

    Fowler, I.L.; Watt, L.A.K.

    1959-12-15

    A single counter tube capable of responding to a wide range of intensities is described. The counter tube comprises a tubular cathode and an anode extending centrally of the cathode. The spacing between the outer surface of the anode and the inner surface of the cathode is varied along the length of the tube to provide different counting volumes in adjacent portions of the tube. A large counting volume in one portion adjacent to a low-energy absorption window gives adequate sensitivity for measuring lowintensity radiation, while a smaller volume with close electrode spacing is provided in the counter to make possible measurement of intense garnma radiation fields.

  15. Time interleaved counter analog to digital converters

    OpenAIRE

    Danesh, Seyed Amir Ali

    2011-01-01

    The work explores extending time interleaving in A/D converters, by applying a high-level of parallelism to one of the slowest and simplest types of data-converters, the counter ADC. The motivation for the work is to realise high-performance re-configurable A/D converters for use in multi-standard and multi-PHY communication receivers with signal bandwidths in the 10s to 100s of MHz. The counter ADC requires only a comparator, a ramp signal, and a digital counter, where the ...

  16. A passive rem counter based on CR39 SSNTD coupled with a boron converter

    CERN Document Server

    Agosteo, S; Ferrarini, c, M; Silari, M

    2009-01-01

    A passive neutron rem counter using a CR39 SSNTD coupled with a boron converter has been developed. The rem counter is a polythene sphere with cadmium and lead insets, designed to have a response function proportional to the fluence to ambient dose equivalent conversion coefficients, H*(10)/Φ, for energies ranging from thermal up to 1 GeV. At its centre is a thermal neutron detector made of a CR39 SSNTD coupled with an enriched boron neutron converter. The rem counter was first calibrated at CERN and at the Politecnico di Milano, and then tested in high-energy neutron fields at GSI, Darmstadt, Germany and at the CERF facility at CERN. Its most important features are a very high neutron sensitivity and conversely a complete insensitivity to gamma radiation.

  17. 2$\\pi$ proportional counting chamber for large-area-coated $\\beta$ sources

    Indian Academy of Sciences (India)

    DESAI SHRADDHA S

    2016-06-01

    Detection system for measuring absolute emission rate from large-area-coated $\\beta$ sources has been indigenously developed. The system consists of a multiwire-based proportional counter with gas flow and a source mounted within the sensitive volume of the detector. Design of the counter enables efficient counting of emissions in $2\\pi$ solid angle.A provision is made for change ofthe source and immediate measurement of source activity. These sources are used to calibrate the efficiency of contamination monitors at radiological facilities. Sensitive area of the detector covers 165◦ solid angle nearing $2\\pi$ of emission from the source of size $100 \\times 150$ mm. Performance of the chamber is tested using collimated $^{55}$Fe X-ray source and $^{90}$Sr / $^{90}$Y coated $\\beta$ sources of various activities. The activity measurement system is established as a national primary standard for calibration of coated $\\beta$ sources at Radiological Laboratory at BARC. Design and performanceof the chamber are presented.

  18. Isovector excitations in 100Nb and their decays by neutron emission studied via the Mo100(t,He3+n reaction at 115 MeV/u

    Directory of Open Access Journals (Sweden)

    K. Miki

    2017-06-01

    Full Text Available Spin–isospin excitations in Nb100 were studied via the Mo100(t,He3 charge-exchange reaction at 115 MeV/u with the goal to constrain theoretical models used to describe the isovector spin response of nuclei. The experiment was performed with a secondary beam of tritons, and 3He particles were analyzed in the S800 magnetic spectrometer. Decay by neutron emission from excited states in Nb100 was observed by using plastic and liquid scintillator arrays. Differential cross sections were analyzed and monopole excitations were revealed by using a multipole decomposition analysis. The Gamow–Teller transition strength observed at low excitation energies, which is important for estimating the electron-capture rate in astrophysical scenarios, was strongly fragmented and reduced compared to single-particle and spherical mean-field models. The consideration of deformation in the theoretical estimates was found to be important to better describe the fragmentation and strengths. A strong excitation of the isovector spin giant monopole resonance was observed, and well reproduced by the mean-field models. Its presence makes the extraction of Gamow–Teller strengths at high excitation energies difficult. The branches for statistical and direct decay by neutron emission were identified in the spectra. The upper limit for the branching ratio by direct decay (integrated over all observed excitations was determined to be 20±6%. Even though the statistical uncertainties in the neutron-coincident data were too large to perform detailed studies of the decay by neutron emission from individual states and resonances, the experiment demonstrates the feasibility of the method.

  19. Permanent traffic counters maintained by the NMDOT

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — A point dataset representing the permanent traffic counters maintained by the NMDOT. Event mapped dataset by LRS info provided by Traffic group.

  20. Development of a Mobile Ice Nucleus Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kok, Gregory [Droplet Measurement Technologies, Boulder, CO (United States); Kulkarni, Gourihar [Droplet Measurement Technologies, Boulder, CO (United States)

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70°C, and a single stage system can operate the warm wall at -45C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  1. Development of a Mobile Ice Nucleus Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kok, Gregory; Kulkarni, Gourihar

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70 deg C, and a single stage system can operate the warm wall at -45 deg C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  2. Lifetime characteristics of Gaiger-Muller counters

    Directory of Open Access Journals (Sweden)

    Kartalović Nenad M.

    2016-01-01

    Full Text Available This paper discusses the process of functional aging of Geiger-Muller counters. Two types of Geiger-Muller counter chambers were characterized in an experiment using a combined constant voltage. Chamber A had a coaxial geometry and chamber B had a plan-parallel geometry. The experimental results indicate that the aging process was faster in the case of chambers with a coaxial geometry. The results are explained based on the process of electrical discharges in gasses.

  3. Progress in studying scintillator proportionality: Phenomenological model

    Energy Technology Data Exchange (ETDEWEB)

    Bizarri, Gregory; Cherepy, Nerine; Choong, Woon-Seng; Hull, Giulia; Moses, William; Payne, Sephen; Singh, Jai; Valentine, John; Vasilev, Andrey; Williams, Richard

    2009-04-30

    We present a model to describe the origin of non-proportional dependence of scintillator light yield on the energy of an ionizing particle. The non-proportionality is discussed in terms of energy relaxation channels and their linear and non-linear dependences on the deposited energy. In this approach, the scintillation response is described as a function of the deposited energy deposition and the kinetic rates of each relaxation channel. This mathematical framework allows both a qualitative interpretation and a quantitative fitting representation of scintillation non-proportionality response as function of kinetic rates. This method was successfully applied to thallium doped sodium iodide measured with SLYNCI, a new facility using the Compton coincidence technique. Finally, attention is given to the physical meaning of the dominant relaxation channels, and to the potential causes responsible for the scintillation non-proportionality. We find that thallium doped sodium iodide behaves as if non-proportionality is due to competition between radiative recombinations and non-radiative Auger processes.

  4. Novel Designs of Quantum Reversible Counters

    Science.gov (United States)

    Qi, Xuemei; Zhu, Haihong; Chen, Fulong; Zhu, Junru; Zhang, Ziyang

    2016-11-01

    Reversible logic, as an interesting and important issue, has been widely used in designing combinational and sequential circuits for low-power and high-speed computation. Though a significant number of works have been done on reversible combinational logic, the realization of reversible sequential circuit is still at premature stage. Reversible counter is not only an important part of the sequential circuit but also an essential part of the quantum circuit system. In this paper, we designed two kinds of novel reversible counters. In order to construct counter, the innovative reversible T Flip-flop Gate (TFG), T Flip-flop block (T_FF) and JK flip-flop block (JK_FF) are proposed. Based on the above blocks and some existing reversible gates, the 4-bit binary-coded decimal (BCD) counter and controlled Up/Down synchronous counter are designed. With the help of Verilog hardware description language (Verilog HDL), these counters above have been modeled and confirmed. According to the simulation results, our circuits' logic structures are validated. Compared to the existing ones in terms of quantum cost (QC), delay (DL) and garbage outputs (GBO), it can be concluded that our designs perform better than the others. There is no doubt that they can be used as a kind of important storage components to be applied in future low-power computing systems.

  5. Proportional loss functions for debris flow events

    Directory of Open Access Journals (Sweden)

    C. M. Rheinberger

    2013-08-01

    Full Text Available Quantitative risk assessments of debris flows and other hydrogeological hazards require the analyst to predict damage potentials. A common way to do so is by use of proportional loss functions. In this paper, we analyze a uniquely rich dataset of 132 buildings that were damaged in one of five large debris flow events in Switzerland. Using the double generalized linear model, we estimate proportional loss functions that may be used for various prediction purposes including hazard mapping, landscape planning, and insurance pricing. Unlike earlier analyses, we control for confounding effects of building characteristics, site specifics, and process intensities as well as for overdispersion in the data. Our results suggest that process intensity parameters are the most meaningful predictors of proportional loss sizes. Cross-validation tests suggest that the mean absolute prediction errors of our models are in the range of 11%, underpinning the accurateness of the approach.

  6. Proportional loss functions for debris flow events

    Science.gov (United States)

    Rheinberger, C. M.; Romang, H. E.; Bründl, M.

    2013-08-01

    Quantitative risk assessments of debris flows and other hydrogeological hazards require the analyst to predict damage potentials. A common way to do so is by use of proportional loss functions. In this paper, we analyze a uniquely rich dataset of 132 buildings that were damaged in one of five large debris flow events in Switzerland. Using the double generalized linear model, we estimate proportional loss functions that may be used for various prediction purposes including hazard mapping, landscape planning, and insurance pricing. Unlike earlier analyses, we control for confounding effects of building characteristics, site specifics, and process intensities as well as for overdispersion in the data. Our results suggest that process intensity parameters are the most meaningful predictors of proportional loss sizes. Cross-validation tests suggest that the mean absolute prediction errors of our models are in the range of 11%, underpinning the accurateness of the approach.

  7. Large-Scale Analysis of Art Proportions

    DEFF Research Database (Denmark)

    Jensen, Karl Kristoffer

    2014-01-01

    While literature often tries to impute mathematical constants into art, this large-scale study (11 databases of paintings and photos, around 200.000 items) shows a different truth. The analysis, consisting of the width/height proportions, shows a value of rarely if ever one (square) and with majo......While literature often tries to impute mathematical constants into art, this large-scale study (11 databases of paintings and photos, around 200.000 items) shows a different truth. The analysis, consisting of the width/height proportions, shows a value of rarely if ever one (square...

  8. LTR design of proportional-integral observers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob; Shafai, B.;

    1995-01-01

    This paper applies the proportional-integral (PI) observer in connection with loop transfer recovery (LTR) design for continuous-time systems. We show that a PI observer makes it possible to obtain time recovery, i.e., exact recovery for t -+ -, under mild conditions. Based on an extension...... of the LQG/LTR method of proportional (P) observers, a systematic LTR design method is derived for the PI observer. Our recovery design method allows time recovery and frequency (normal) recovery to be done independently. Furthermore, we give explicit expressions for the recovery error when asymptotic...

  9. Proportional hazards models with discrete frailty.

    Science.gov (United States)

    Caroni, Chrys; Crowder, Martin; Kimber, Alan

    2010-07-01

    We extend proportional hazards frailty models for lifetime data to allow a negative binomial, Poisson, Geometric or other discrete distribution of the frailty variable. This might represent, for example, the unknown number of flaws in an item under test. Zero frailty corresponds to a limited failure model containing a proportion of units that never fail (long-term survivors). Ways of modifying the model to avoid this are discussed. The models are illustrated on a previously published set of data on failures of printed circuit boards and on new data on breaking strengths of samples of cord.

  10. Divining Proportions in the Information Age

    Directory of Open Access Journals (Sweden)

    Andrew Tallon

    2014-06-01

    Full Text Available The process of reverse engineering proportional systems of historic buildings has long been fraught with problems. One cannot assume, without knowing the specific conditions of acquisition, that existing plans are accurate enough to sustain the scrutiny necessary to resolve differences among potential proportional schemes. Yet producing a new survey with conventional measurement instruments could take weeks, if not months, and only in the best of situations would it be possible to acquire data in the upper reaches of the building—information required to avoid arbitrary dimensional rectification. With the advent of high-speed and high-precision laser scanning, however, the situation has changed dramatically.

  11. Design of reduced size long counter with flat response function from few keV to 20 MeV

    Directory of Open Access Journals (Sweden)

    Mazunga Mohamed

    2016-01-01

    Full Text Available In this study, a reduced size neutron long counter with improved response function was designed using SuperMC simulation code. The main parts of the reduced size long counter are 3He proportional counter, cylindrical moderators made of polyethylene, chromium metal converter, neutron absorber material and outer aluminum cover. A 1.5 cm thick layer of chromium metal was embedded into the hydrogen-rich moderator to enhance response of the long counter at high neutron energies. The radius and length of the long counter was reduced to 15 cm and 35 cm, respectively. In this design we managed to obtain a flat response function from a few keV to 20 MeV energy range. The angular response function, determined at 0.5 MeV and 14 MeV neutron energies, confirmed that the reduced size long counter designed in this study is not significantly affected by in-scattered neutrons. The reduced size long counter is suitable for use as a standard transfer instrument for monitoring neutron fluence in mono-energetic neutron fields.

  12. Counter-diffusion and -permeation of deuterium and hydrogen through metals

    Energy Technology Data Exchange (ETDEWEB)

    Kizu, Kaname; Tanabe; Tetsuo [Nagoya Univ. (Japan)

    1998-03-01

    The first experiments for counter-diffusion and -permeation of deuterium and hydrogen through palladium were performed. Deuterium permeation rates against D{sub 2} pressure were measured under the condition where hydrogen permeated to opposite direction by supplying H{sub 2} gas at the permeated side of D{sub 2}. It was found that not a small amount of deuterium was clearly permeated even if the deuterium pressure was much smaller than the hydrogen pressure. Deuterium permeation rate was gradually reduced by increasing the counter H permeation. The deuterium permeation rate under the counter H permeation is well represented by a simple model in which the ratio of the deuterium permeation rates with and without the counter H permeation was proportional to the fractional concentration of deuterium in the bulk. As increasing the hydrogen counter flow, however, the deuterium permeation rate deviates from the model. This means that adsorption (absorption) of D{sub 2} from gas phase is inhibited and surface recombination of deuterium is blocked by hydrogen. (author)

  13. Kitchen Gardens: Contexts for Developing Proportional Reasoning

    Science.gov (United States)

    Hilton, Annette; Hilton, Geoff; Dole, Shelley; Goos, Merrilyn; O'Brien, Mia

    2013-01-01

    It is great to see how the sharing of ideas sparks new ideas. In 2011 Lyon and Bragg wrote an "Australian Primary Mathematics Classroom" (APMC) article on the mathematics of kitchen gardens. In this article the authors show how the kitchen garden may be used as a starting point for proportional reasoning. The authors highlight different…

  14. Golden Proportions for the Generalized Tribonacci Numbers

    Science.gov (United States)

    Shah, Devbhadra V.; Mehta, Darshana A.

    2009-01-01

    It is known that the ratios of consecutive terms of Fibonacci and Tribonacci sequences converge to the fixed ratio. In this article, we consider the generalized form of Tribonacci numbers and derive the "golden proportion" for the whole family of this generalized sequence. (Contains 2 tables.)

  15. Adaptive bayesian analysis for binomial proportions

    CSIR Research Space (South Africa)

    Das, Sonali

    2008-10-01

    Full Text Available The authors consider the problem of statistical inference of binomial proportions for non-matched, correlated samples, under the Bayesian framework. Such inference can arise when the same group is observed at a different number of times with the aim...

  16. Quantitative basis for component factors of gas flow proportional counting efficiencies

    Science.gov (United States)

    Nichols, Michael C.

    This dissertation investigates the counting efficiency calibration of a gas flow proportional counter with beta-particle emitters in order to (1) determine by measurements and simulation the values of the component factors of beta-particle counting efficiency for a proportional counter, (2) compare the simulation results and measured counting efficiencies, and (3) determine the uncertainty of the simulation and measurements. Monte Carlo simulation results by the MCNP5 code were compared with measured counting efficiencies as a function of sample thickness for 14C, 89Sr, 90Sr, and 90Y. The Monte Carlo model simulated strontium carbonate with areal thicknesses from 0.1 to 35 mg cm-2. The samples were precipitated as strontium carbonate with areal thicknesses from 3 to 33 mg cm-2 , mounted on membrane filters, and counted on a low background gas flow proportional counter. The estimated fractional standard deviation was 2--4% (except 6% for 14C) for efficiency measurements of the radionuclides. The Monte Carlo simulations have uncertainties estimated to be 5 to 6 percent for carbon-14 and 2.4 percent for strontium-89, strontium-90, and yttrium-90. The curves of simulated counting efficiency vs. sample areal thickness agreed within 3% of the curves of best fit drawn through the 25--49 measured points for each of the four radionuclides. Contributions from this research include development of uncertainty budgets for the analytical processes; evaluation of alternative methods for determining chemical yield critical to the measurement process; correcting a bias found in the MCNP normalization of beta spectra histogram; clarifying the interpretation of the commonly used ICRU beta-particle spectra for use by MCNP; and evaluation of instrument parameters as applied to the simulation model to obtain estimates of the counting efficiency from simulated pulse height tallies.

  17. Design and Characterization of Next-Generation Tissue Equivalent Proportional Counters for use in Low Energy Neutron Fields

    Science.gov (United States)

    Ashmeg, Sarah

    Since the publication of TG119 in 2009, new techniques have emerged in the field of radiation therapy including VMAT (Volumetric Arc Therapy) and the FFF (Flattening Filter Free) mode in Varian linear accelerators. Our goal in this work is to verify the feasibility of using TG119 to test the commissioning of VMAT and FFF systems and to set a benchmark for other institutions to use. We created 48 plans of the five sites given in TG119 in addition to a "real" HN case. For each site, we planned IMRT and VMAT using 6MV and 10MV, FF and FFF modes (6x2x2x2 = 48 plans). All our plans were created on the Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA) and delivered on three beam-matched TrueBeam linear accelerators (Varian) at Duke University Medical Center. Measurements were taken using ion chamber, film, and a pseudo-3D diode array (Delta4), and compared to the planned doses. Confidence limits were determined using the approach of TG119 (CL = average mean deviation + 1.96 x standard deviation). We used the student's paired t-test to determine any statistically significant differences between IMRT and VMAT, FF and FFF for 6MV and 10MV. The majority of the ion chamber measurements (94%) agreed with the planned doses within 3%. The majority of errors > 3% involved the HN IMRT plans, either TG119 or "real". For film measurements, we used gamma parameters of 3%/3mm with a 20% threshold. All films met Duke's acceptability criteria of <= 10% of pixels failing gamma. As for Delta4, gamma parameters of 3%/3mm with a 5% threshold were used. All plans met Duke's acceptability criteria of 90% of pixels passing (average 99.7% +/- 0.8%). A second analysis was performed using 2%/2mm gamma parameters, where almost all plans met the 90% passing rate criteria (average 98.9% +/- 2.5%). Confidence limits were established for ion chamber (3.1%), film (6%), and Delta4 (3.1%) measurements. All the confidence limits were comparable to TG119 institutions. We recommend that non-clinical plans (e.g. 10MV HN plans) not be included in TG119 evaluations. We also recommend that film continue to be used as the gold standard of multi-dimensional measurements, rather than be replaced by diode-based technology.

  18. A new shallow underground gas-proportional counting lab--first results and Ar-37 sensitivity.

    Science.gov (United States)

    Aalseth, C E; Day, A R; Fuller, E S; Hoppe, E W; Keillor, M E; Leferriere, B; Mace, E K; Merriman, J; Myers, A W; Overman, C T; Panisko, M E; Seifert, A; Warren, G A; Williams, R M

    2013-11-01

    A new ultra-low-background proportional counter was recently developed with an internal volume of 100 cm(3) and has been characterized at pressures from 1-10 atm with P-10 (90% Ar, 10% methane) gas. This design, along with a counting system providing event digitization and passive and active shielding, has been developed to complement a new shallow underground laboratory (30 m water-equivalent). Backgrounds and low-level reference materials have been measured, and system sensitivity for (37)Ar has been calculated.

  19. Study of Proportional Counting System With Detective Area Larger Than 1000 cm~2

    Institute of Scientific and Technical Information of China (English)

    LIN; Min; CHEN; Ke-sheng; XU; Li-jun; XIA; Wen; YE; Hong-sheng; ZHANG; Wei-dong; CHEN; Yi-zhen; YAO; Yan-ling; WANG; Jian-qing; YAO; Shun-he; LI; Ming

    2013-01-01

    In order to determine the emission rate of the large-area source that active area is up to 1 000 cm2,a suit of non-window type large-area 2πmulti-wire proportional counter was established.Thecharacteristics of the whole system were tested using both point source with active diameter of 8 mm and large-area source with active size of 10 cm×15 cm.The results show that the effective detective area is up

  20. A gas scintillation counter with imaging optics and large area UV-detector

    Energy Technology Data Exchange (ETDEWEB)

    Nickles, J. E-mail: nickles@hsb.uni-frankfurt.de; Braeuning, H.; Braeuning-Demian, A.; Dangendorf, V.; Breskin, A.; Chechik, R.; Rauschnabel, K.; Schmidt-Boecking, H

    2002-01-21

    We report on the improvements in the position sensitive readout of a xenon-filled gas scintillation proportional counter. Using an imaging optic for UV-light in the region of 170 nm, the position resolution could be improved by more than 30%. In addition, we have obtained first encouraging results for the use of the recently developed gas electron multiplier together with a CsI-photocathode as a large area UV-detector system.

  1. A gas scintillation counter with imaging optics and large area UV-detector

    CERN Document Server

    Nickles, J; Bräuning-Demian, A; Breskin, Amos; Chechik, R; Dangendorf, V; Rauschnabel, K; Schmidt-Böcking, H

    2002-01-01

    We report on the improvements in the position sensitive readout of a xenon-filled gas scintillation proportional counter. Using an imaging optic for UV-light in the region of 170 nm, the position resolution could be improved by more than 30%. In addition, we have obtained first encouraging results for the use of the recently developed gas electron multiplier together with a CsI-photocathode as a large area UV-detector system.

  2. Detecting the Elusive Blazar Counter-Jets

    CERN Document Server

    Liodakis, I; Angelakis, E

    2016-01-01

    Detection of blazar pc scale counter-jets is difficult, but it can provide invaluable insight into the relativistic effects, radiative processes and the complex mechanisms of jet production, collimation and accelation in blazars. We build on recent populations models (optimized using the MOJAVE apparent velocity and redshift distributions) in order to derive the distribution of jet-to-counter-jet ratios and the flux densities of the counter-jet at different frequencies, in an effort to set minimum sensitivity limits required for existing and future telescope arrays in order to detect these elusive counter-jets. We find that: for the BL Lacs $5\\%$ of their counter-jets have a flux-density higher than 100mJy, $15\\%$ are higher than 10 mJy, and $32\\%$ have higher flux-density than 1 mJy, whereas for the FSRQs $8\\%$ have a flux-density higher than 10mJy, $17\\%$ are higher than 1 mJy, and $32\\%$ are higher than 0.1 mJy (at 15 GHz). Future telescopes like the SKA and newly operating like e-MERLIN and JVLA may detec...

  3. Efficacy paradox and proportional contextual effect (PCE).

    Science.gov (United States)

    Zhang, Weiya; Doherty, Michael

    2017-07-20

    The "efficacy paradox" is when the effect of a treatment tested in an RCT, or evidence-based guideline advice, differs markedly from treatment benefits observed in clinical practice. This arises because in RCT reporting and guideline development treatment efficacy is judged by the separation of the treatment group from the placebo group (the specific treatment effect) whereas in clinical practice it is the overall treatment effect, which includes both specific and contextual responses, that patients experience. This paradox causes a disconnect between guidelines and clinical practice and ignores the importance of contextual response in clinical care. This article fully explains and discusses these issues and presents a possible way to reduce the paradox through an alteration in RCT reporting that shifts the focus to overall treatment benefit and the proportion ("proportional contextual effect") that is explained by placebo and contextual effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Proportional Fair Coding for Wireless Mesh Networks

    CERN Document Server

    Karumbu, Premkumar; Leith, Douglas

    2012-01-01

    We consider multi--hop wireless networks carrying unicast flows for multiple users. Each flow has a specified delay deadline, and the lossy wireless links are modelled as binary symmetric channels (BSCs). Since transmission time, also called airtime, on the links is shared amongst flows, increasing the airtime for one flow comes at the cost of reducing the airtime available to other flows sharing the same link. We derive the joint allocation of flow airtimes and coding rates that achieves the proportionally fair throughput allocation. This utility optimisation problem is non--convex, and one of the technical contributions of this paper is to show that the proportional fair utility optimisation can nevertheless be decomposed into a sequence of convex optimisation problems. The solution to this sequence of convex problems is the unique solution to the original non--convex optimisation. Surprisingly, this solution can be written in an explicit form that yields considerable insight into the nature of the proporti...

  5. Developing Essential Understanding of Ratios, Proportions, and Proportional Reasoning for Teaching Mathematics: Grades 6-8

    Science.gov (United States)

    Lobato, Joanne; Ellis, Amy; Zbiek, Rose Mary

    2010-01-01

    How do you refute the erroneous claim that all ratios are fractions? This book goes beyond a simple introduction to ratios, proportions, and proportional reasoning. It will help broaden and deepen your mathematical understanding of one of the most challenging topics for students--and teachers--to grasp. It will help you engage your students,…

  6. Proportional Reasoning of Preservice Elementary Education Majors: An Epistemic Model of the Proportional Reasoning Construct.

    Science.gov (United States)

    Fleener, M. Jayne

    Current research and learning theory suggest that a hierarchy of proportional reasoning exists that can be tested. Using G. Vergnaud's four complexity variables (structure, content, numerical characteristics, and presentation) and T. E. Kieren's model of rational number knowledge building, an epistemic model of proportional reasoning was…

  7. Ideal proportional navigation for exoatmospheric interception

    Institute of Scientific and Technical Information of China (English)

    Li Kebo; Zhang Taotao; Chen Lei

    2013-01-01

    Ideal proportional navigation (IPN) is a natural choice for exoatmospheric interception for its mighty capture capability and ease of implementation.The closed-form solution of two-dimensional ideal proportional navigation was conducted in previous public literature,whereas the practical interception happens in the three-dimensional space.A novel set of relative dynamic equations is adopted in this paper,which is with the advantage of decoupling relative motion in the instantaneous rotation plane of the line of sight from the rotation of this plane.The dimension-reduced IPN is constructed in this instantaneous plane,which functions as a three-dimensional guidance law.The trajectory features of dimension-reduced IPN are explored,and the capture regions of dimension-reduced IPN with limited acceleration against nonmaneuvering and maneuvering targets are analyzed by using phase plane method.It is proved that the capture capability of IPN is much stronger than true proportional navigation (TPN),no matter the target maneuvers or not.Finally,simulation results indicate that IPN is more effective than TPN in exoatmospheric interception scenarios.

  8. Band Control of Mutual Proportional Reinsurance

    CERN Document Server

    Liu, John; Yuan, Jiguang

    2011-01-01

    In this paper, we investigate the optimization of mutual proportional reinsurance --- a mutual reserve system that is intended for the collective reinsurance needs of homogeneous mutual members, such as P&I Clubs in marine mutual insurance and reserve banks in the U.S. Federal Reserve. Compared to general (non-mutual) insurance models, which involve one-sided impulse control (i.e., either downside or upside impulse) of the underlying insurance reserve process that is required to be positive, a mutual insurance differs in allowing two-sided impulse control (i.e., both downside and upside impulse), coupled with the classical proportional control of reinsurance. We prove that a special band-type impulse control $(a,A,B,b)$ with $a=0$ and $aproportional reinsurance policy (classical control), is optimal when the objective is to minimize the total maintenance cost. That is, when the reserve position reaches a lower boundary of $a=0$, the reserve should immediately be raised to ...

  9. Evaluation of Facial Beauty Using Anthropometric Proportions

    Directory of Open Access Journals (Sweden)

    Jovana Milutinovic

    2014-01-01

    Full Text Available The improvement of a patient’s facial appearance is one of the main goals of contemporary orthodontic treatment. The aim of this investigation was to evaluate the difference in facial proportions between attractive and anonymous females in order to establish objective facial features which are widely considered as beautiful. The study included two groups: first group consisted of 83 Caucasian female subjects between 22 and 28 years of age who were selected from the population of students at the University of Belgrade, and the second group included 24 attractive celebrity Caucasian females. The en face facial photographs were taken in natural head position (NHP. Numerous parameters were recorded on these photographs, in order to establish facial symmetry and correlation with the ideal set of proportions. This study showed significant difference between anonymous and attractive females. Attractive females showed smaller face in general and uniformity of the facial thirds and fifths, and most of the facial parameters meet the criteria of the ideal proportions.

  10. The Proportion of Stars with Planets

    Science.gov (United States)

    Woolfson, M. M.

    2016-04-01

    Estimates of the proportion of Sun-like stars with accompanying planets vary widely; the best present estimate is that it is about 0.34. The capture theory of planet formation involves an interaction between a condensed star and either a diffuse protostar or a high-density region in a dense embedded cluster. The protostar, or dense region, is tidally stretched into a filament that is gravitationally unstable and breaks up into a string of protoplanetary blobs, which subsequently collapse to form planets, some of which are captured by the star. A computational model, in which the passage of collapsing protostars, with initial radii 1000, 1500 and 2000 au, through a dense embedded cluster are followed, is used to estimate the proportion of protostars that would be disrupted to give planets, in environments with star number-densities in the range 5000-25,000 pc-3. It is concluded from the results that the capture theory might explain the presently-estimated proportion of stars with exoplanet companions, although other possible ways of producing exoplanets are not excluded.

  11. The AMS-01 Aerogel Threshold Cherenkov counter

    Energy Technology Data Exchange (ETDEWEB)

    Barancourt, D.; Barao, F.; Barbier, G.; Barreira, G.; Buenerd, M.; Castellini, G.; Choumilov, E.; Favier, J.; Fouque, N.; Gougas, A.; Hermel, V.; Kossakowski, R.; Laborie, G.; Laurenti, G.; Lee, S.-C.; Mayet, F. E-mail: frederic.mayet@isn.in2p3.fr; Meillon, B.; Oyang, Y.-T.; Plyaskin, V.; Pojidaev, V.; Rossin, C.; Santos, D.; Vezzu, F.; Vialle, J.P

    2001-06-11

    The Alpha Magnetic Spectrometer in a precursor version (AMS-01), was flown in June 1998 on a 51.6 deg. orbit and at altitudes ranging between 320 and 390 km, on board of the space shuttle Discovery (flight STS-91). AMS-01 included an Aerogel Threshold Cherenkov counter (ATC) to separate p-bar from e{sup -} and e{sup +} from p, for momenta below 3.5 GeV/c. This paper presents a description of the ATC counter and reports on its performances during the flight STS-91.

  12. The AMS-01 Aerogel Threshold Cherenkov counter

    CERN Document Server

    Barancourt, D; Barbier, G; Barreira, G; Buénerd, M; Castellini, G; Choumilov, E; Favier, Jean; Fouque, N; Gougas, Andreas; Hermel, V; Kossakowski, R; Laborie, G; Laurenti, G; Lee, S C; Mayet, F; Meillon, B; Oyang, J Y T; Plyaskin, V; Pozhidaev, V; Rossin, C; Santos, D; Vezzu, F; Vialle, J P

    2001-01-01

    The Alpha Magnetic Spectrometer in a precursor version (AMS-01), was flown in June 1998 on a 51.6 degrees orbit and at altitudes ranging between 320 and 390 km, on board of the space shuttle Discovery (flight STS-91). AMS-01 included an Aerogel Threshold Cherenkov counter (ATC) to separate antiprotons from electrons and positrons from protons, for momenta below 3.5 GeV/c. This paper presents a description of the ATC counter and reports on its performances during the flight STS-91.

  13. Analysis of counter-rotating wind turbines

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Zakkam, Vinod Arun Kumar; Sørensen, Jens Nørkær

    2007-01-01

    This paper presents a study on the performance of a wind turbine with two counter-rotating (CRWT) rotors. The characteristics of the two counter-rotating rotors are on a 3-bladed Nordtank 500 kW rotor. The analysis has been carried out by using an Actuator Line technique implemented in the Navier......-Stokes code EllipSys3D. The analysis shows that the Annual Energy Production can be increased to about 43.5 %, as compared to a wind turbine with a single rotor. In order to determine the optimal settings of the CRWT turbine, parameters such as distance between two rotors and rotational speed have been...

  14. Development of DUPIC safeguards neutron counter

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Gil; Cha, Hong Ryul; Kim, Ho Dong; Hong, Jong Sook; Kang, Hee Young

    1999-08-01

    KAERI, in cooperation with LANL, developed DSNC (DUPIC Safeguards Neutron Counter) for safeguards implementing on DUPIC process which is under development by KAERI for direct use of spent PWR fuel in CANDU reactors. DSNC is a well-type neutron coincidence counter with substantial shielding to protect system from high gamma radiation of spent fuel. General development procedures in terms of design, manufacturing, fabrication, cold and hot test, performance test for DSNC authentication by KAERI-IAEA-LANL are described in this report. It is expected that the techniques related DSNC development and associated neutron detection and evaluation method could be applied for safeguards improvement. (Author). 20 refs., 16 tabs. 98 figs.

  15. Development of DUPIC safeguards neutron counter

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Gil; Cha, Hong Ryul; Kim, Ho Dong; Hong, Jong Sook; Kang, Hee Young

    1999-08-01

    KAERI, in cooperation with LANL, developed DSNC (DUPIC Safeguards Neutron Counter) for safeguards implementing on DUPIC process which is under development by KAERI for direct use of spent PWR fuel in CANDU reactors. DSNC is a well-type neutron coincidence counter with substantial shielding to protect system from high gamma radiation of spent fuel. General development procedures in terms of design, manufacturing, fabrication, cold and hot test, performance test for DSNC authentication by KAERI-IAEA-LANL are described in this report. It is expected that the techniques related DSNC development and associated neutron detection and evaluation method could be applied for safeguards improvement. (Author). 20 refs., 16 tabs. 98 figs.

  16. [Application of the BACspreader™ Microbe Dispersion Counter in drug susceptibility test on Mycobacterium tuberculosis].

    Science.gov (United States)

    Jiang, Y; Li, J; Zhang, Y Y; Wu, J; Wang, L L; Yu, C L; Shen, X; Zhu, G F

    2017-04-12

    Objective: To evaluate the application of the BACspreader™ Microbe Dispersion Counter in drug susceptibility test (DST) on Mycobacterium tuberculosis (MTB). Methods: The MTB strains were dispersed and diluted to 1.0 McFarland standard turbidity, by means of BACspreader™ Microbe Dispersion Counter and manual grinding method, respectively. The bacterial dispersion effect and bacterial activity were tested by microscope and colony counting method. During Jan. 2015 to June 2015, a total of 726 isolates of MTB were collected in all district tuberculosis hospitals of Shanghai. The bacterial suspension dispersed by instrument and manual grinding, were inoculated in slant medium for DST (Proportion Method), and then incubated in 37 ℃ incubator for 28 days and the DST results were reported. The effects of the 2 different bacterial dispersion methods were compared by comparing DST results and counting the bacterial colony which grew in high and low concentration control media. Paired chi-square test was used for statistical analysis, and the significance level was 0.05. Results: Compared to the manual grinding method, the MTB colony could be better dispersed by BACspreader™ Microbe Dispersion Counter, without reducing the bacterial activity. The DST results of 726 mycobacterial isolates were the same by different bacterial dispersion methods. The count of bacterial colony growing in high concentration control medium was significantly different between of the 2 dispersion methods (χ(2)=8.0, PDispersion Counter, and 4.3% by manual grinding method; the difference being significant between the 2 dispersion methods (χ(2)=674, PDispersion Counter had better countability in low concentration control slants, and had more significant contrast between high and low concentration control slants, which was useful to determine the DST results. Introducing the BACspreader™ Microbe Dispersion Counter to MTB DST could automate the DST process, make the testing results objective

  17. Upaya Perumusan Prinsip Counter Accounting Melalui Filosofi Punk Sebagai Counter Culture

    Directory of Open Access Journals (Sweden)

    Dayno Utama

    2015-12-01

    Full Text Available The aim of this research is to demonstrate that resistance to mainstream research contained in top/elite accounting journals for sparking creativity and innovation unconsciously has utilized the philosophy of punk. The research method of this research is argumentation technique. The result of this research shows that the philosophy of punk as counter culture can be utilized for accounting research through formulation the accounting principles namely counter accounting. Creative and innovative accounting as forms of counter accounting towards mainstream accounting tradition especially in elite journals, will not pervade in a short time.

  18. Experimental design of laminar proportional amplifiers

    Science.gov (United States)

    Hellbaum, R. F.

    1976-01-01

    An experimental program was initiated at Langley Research Center to study the effects of various parameters on the design of laminar proportional beam deflection amplifiers. Matching and staging of amplifiers to obtain high-pressure gain was also studied. Variable parameters were aspect ratio, setback, control length, receiver distance, receiver width, width of center vent, and bias pressure levels. Usable pressure gains from 4 to 19 per stage can now be achieved, and five amplifiers were staged together to yield pressure gains up to 2,000,000.

  19. Designing an optimally proportional inorganic scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai, E-mail: jai.singh@cdu.edu.au [School of Engineering and IT, B-Purple-12, Faculty of EHSE, Charles Darwin University, NT 0909 (Australia); Koblov, Alexander [School of Engineering and IT, B-Purple-12, Faculty of EHSE, Charles Darwin University, NT 0909 (Australia)

    2012-09-01

    The nonproportionality observed in the light yield of inorganic scintillators is studied theoretically as a function of the rates of bimolecular and Auger quenching processes occurring within the electron track initiated by a gamma- or X-ray photon incident on a scintillator. Assuming a cylindrical track, the influence of the track radius and concentration of excitations created within the track on the scintillator light yield is also studied. Analysing the calculated light yield a guideline for inventing an optimally proportional scintillator with optimal energy resolution is presented.

  20. 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.

  1. COUNTER-ROTATION IN RELATIVISTIC MAGNETOHYDRODYNAMIC JETS

    Energy Technology Data Exchange (ETDEWEB)

    Cayatte, V.; Sauty, C. [Laboratoire Univers et Théories, Observatoire de Paris, UMR 8102 du CNRS, Université Paris Diderot, F-92190 Meudon (France); Vlahakis, N.; Tsinganos, K. [Department of Astrophysics, Astronomy and Mechanics, Faculty of Physics, University of Athens, 15784 Zografos, Athens (Greece); Matsakos, T. [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States); Lima, J. J. G., E-mail: veronique.cayatte@obspm.fr [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

    2014-06-10

    Young stellar object observations suggest that some jets rotate in the opposite direction with respect to their disk. In a recent study, Sauty et al. showed that this does not contradict the magnetocentrifugal mechanism that is believed to launch such outflows. Motion signatures that are transverse to the jet axis, in two opposite directions, have recently been measured in M87. One possible interpretation of this motion is that of counter-rotating knots. Here, we extend our previous analytical derivation of counter-rotation to relativistic jets, demonstrating that counter-rotation can indeed take place under rather general conditions. We show that both the magnetic field and a non-negligible enthalpy are necessary at the origin of counter-rotating outflows, and that the effect is associated with a transfer of energy flux from the matter to the electromagnetic field. This can be realized in three cases: if a decreasing enthalpy causes an increase of the Poynting flux, if the flow decelerates, or if strong gradients of the magnetic field are present. An illustration of the involved mechanism is given by an example of a relativistic magnetohydrodynamic jet simulation.

  2. Can counter-stereotypes boost flexible thinking?

    NARCIS (Netherlands)

    M.A. Goclowska; R.J. Crisp; K. Labuschagne

    2012-01-01

    To reduce prejudice psychologists design interventions requiring people to think of counter-stereotypes (i.e., people who defy stereotypic expectations—a strong woman, a Black President). Grounded in the idea that stereotypes constrain the ability to think flexibly, we propose that thinking of count

  3. International perspectives on countering school segregation

    NARCIS (Netherlands)

    Bakker, J.T.A.; Denessen, E.J.P.G.; Peters, T.J.M.; Walraven, G.

    2010-01-01

    School segregation is perceived as an unyielding problem worldwide, which is manifest along both ethnic and socio-economic lines. With this edited volume we aim to share information about school segregation and policies focused on countering school segregation from an international perspective. Many

  4. Counter Trafficking System Development "Analysis Training Program"

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Dennis C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-12-01

    This document will detail the training curriculum for the Counter-Trafficking System Development (CTSD) Analysis Modules and Lesson Plans are derived from the United States Military, Department of Energy doctrine and Lawrence Livermore National Laboratory (LLNL), Global Security (GS) S Program.

  5. Can counter-stereotypes boost flexible thinking?

    NARCIS (Netherlands)

    Goclowska, M.A.; Crisp, R.J.; Labuschagne, K.

    2013-01-01

    To reduce prejudice psychologists design interventions requiring people to think of counter-stereotypes (i.e., people who defy stereotypic expectations—a strong woman, a Black President). Grounded in the idea that stereotypes constrain the ability to think flexibly, we propose that thinking of count

  6. Cerenkov counters at the Omega Facility

    CERN Multimedia

    1975-01-01

    P. Petroff on the left. Here one sees both the gas Cerenkov counters sitting in front of the magnet to select forward emitted particles. The smaller one, working at high pressure, sits nearest to the Omega magnet (see photo 7505073X), the other (see photo 7505071X) works at atmospheric pressure.

  7. One-Counter Markov Decision Processes

    NARCIS (Netherlands)

    Brazdil, T.; Brozek, V.; Etessami, K.; Kucera, A.; Wojtczak, D.K.; Charikar, M.

    2010-01-01

    We study the computational complexity of central analysis problems for One-Counter Markov Decision Processes (OC-MDPs), a class of finitely-presented, countable-state MDPs. OC-MDPs are equivalent to a controlled extension of (discrete-time) Quasi-Birth-Death processes (QBDs), a stochastic model stud

  8. Ultrafine Condensation Particle Counter Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-01

    The Model 3776 Ultrafine Condensation Particle Counter (UCPC; pictured in Appendix A) is designed for researchers interested in airborne particles smaller than 20 nm. With sensitivity to particles down to 2.5 nm in diameter, this UCPC is ideally suited for atmospheric and climate research, particle formation and growth studies, combustion and engine exhaust research, and nanotechnology research.

  9. Energy Proportionality for Disk Storage Using Replication

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinoh; Rotem, Doron

    2010-09-09

    Energy saving has become a crucial concern in datacenters as several reports predict that the anticipated energy costs over a three year period will exceed hardware acquisition. In particular, saving energy for storage is of major importance as storage devices (and cooling them off) may contribute over 25 percent of the total energy consumed in a datacenter. Recent work introduced the concept of energy proportionality and argued that it is a more relevant metric than just energy saving as it takes into account the tradeoff between energy consumption and performance. In this paper, we present a novel approach, called FREP (Fractional Replication for Energy Proportionality), for energy management in large datacenters. FREP includes areplication strategy and basic functions to enable flexible energy management. Specifically, our method provides performance guarantees by adaptively controlling the power states of a group of disks based on observed and predicted workloads. Our experiments, using a set of real and synthetic traces, show that FREP dramatically reduces energy requirements with a minimal response time penalty.

  10. Viking-Age Sails: Form and Proportion

    Science.gov (United States)

    Bischoff, Vibeke

    2017-04-01

    Archaeological ship-finds have shed much light on the design and construction of vessels from the Viking Age. However, the exact proportions of their sails remain unknown due to the lack of fully preserved sails, or other definite indicators of their proportions. Key Viking-Age ship-finds from Scandinavia—the Oseberg Ship, the Gokstad Ship and Skuldelev 3—have all revealed traces of rigging. In all three finds, the keelson—with the mast position—is preserved, together with fastenings for the sheets and the tack, indicating the breadth of the sail. The sail area can then be estimated based on practical experience of how large a sail the specific ship can carry, in conjunction with hull form and displacement. This article presents reconstructions of the form and dimensions of rigging and sail based on the archaeological finds, evidence from iconographic and written sources, and ethnographic parallels with traditional Nordic boats. When these sources are analysed, not only do the similarities become apparent, but so too does the relative disparity between the archaeological record and the other sources. Preferential selection in terms of which source is given the greatest merit is therefore required, as it is not possible to afford them all equal value.

  11. Counter-Narratives and the Unrehearsed Stories Counter-Terrorists Unwittingly Produce.

    OpenAIRE

    Beatrice de Graaf

    2009-01-01

    Governments produce both deliberate and involuntary (and less conscious) narratives when countering terrorism. The thesis of this article is that such unintended messages can be much more powerful and consequential than is realized; in fact, they can completely contradict the intended official 'counter-narrative'. To substantiate this hypothesis, the author looks at the experience of the German Federal Republic in the 1970s and beyond when state and society were confronted with the Red Army F...

  12. The 10B based Jalousie neutron detector - An alternative for 3He filled position sensitive counter tubes

    Science.gov (United States)

    Henske, M.; Klein, M.; Köhli, M.; Lennert, P.; Modzel, G.; Schmidt, C. J.; Schmidt, U.

    2012-09-01

    Over the last decades 3He filled proportional counter tubes were the working horse employed to serve as neutron counters especially in cases where large area coverage was required. Today the lack of 3He demands the development of an alternative technology. Here we present a prototype neutron detector that is based on a concept with solid 10B as neutron converter and aims for large area neutron detection applications. We report on first experimental results obtained with this prototype to demonstrate the feasibility and operational readiness of our concept.

  13. The {sup 10}B based Jalousie neutron detector - An alternative for {sup 3}He filled position sensitive counter tubes

    Energy Technology Data Exchange (ETDEWEB)

    Henske, M. [CDT CASCADE Detector Technologies GmbH, Hans-Bunte-Str. 8-10, 69123 Heidelberg (Germany); Klein, M., E-mail: martin.klein@physi.uni-heidelberg.de [Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg (Germany); CDT CASCADE Detector Technologies GmbH, Hans-Bunte-Str. 8-10, 69123 Heidelberg (Germany); Koehli, M.; Lennert, P.; Modzel, G. [Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg (Germany); Schmidt, C.J. [CDT CASCADE Detector Technologies GmbH, Hans-Bunte-Str. 8-10, 69123 Heidelberg (Germany); GSI Detector Laboratory, Planckstrasse 1, 64291 Darmstadt (Germany); Schmidt, U. [Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg (Germany)

    2012-09-11

    Over the last decades {sup 3}He filled proportional counter tubes were the working horse employed to serve as neutron counters especially in cases where large area coverage was required. Today the lack of {sup 3}He demands the development of an alternative technology. Here we present a prototype neutron detector that is based on a concept with solid {sup 10}B as neutron converter and aims for large area neutron detection applications. We report on first experimental results obtained with this prototype to demonstrate the feasibility and operational readiness of our concept.

  14. Active vibration isolation by adaptive proportional control

    Science.gov (United States)

    Liu, Yun-Hui; Wu, Wei-Hao; Chu, Chih-Liang

    2013-01-01

    An active vibration isolation system that applies proportional controller incorporated with an adaptive filter to reduce the transmission of base excitations to a precision instrument is proposed in this work. The absolute vibration velocity signal acquired from an accelerator and being processed through an integrator is input to the controller as a feedback signal, and the controller output signal drives the voice coil actuator to produce a sky-hook damper force. In practice, the phase response of integrator at low frequency such as 2~5 Hz deviate from the 90 degree which is the exact phase difference between the vibration velocity and acceleration. Therefore, an adaptive filter is used to compensate the phase error in this paper. An analysis of this active vibration isolation system is presented, and model predictions are compared to experimental results. The results show that the proposed method significantly reduces transmissibility at resonance without the penalty of increased transmissibility at higher frequencies.

  15. Scaling and universality in proportional elections.

    Science.gov (United States)

    Fortunato, Santo; Castellano, Claudio

    2007-09-28

    A most debated topic of the last years is whether simple statistical physics models can explain collective features of social dynamics. A necessary step in this line of endeavor is to find regularities in data referring to large-scale social phenomena, such as scaling and universality. We show that, in proportional elections, the distribution of the number of votes received by candidates is a universal scaling function, identical in different countries and years. This finding reveals the existence in the voting process of a general microscopic dynamics that does not depend on the historical, political, and/or economical context where voters operate. A simple dynamical model for the behavior of voters, similar to a branching process, reproduces the universal distribution.

  16. TRIAC/SCR proportional control circuit

    Science.gov (United States)

    Hughes, W.J.

    1999-04-06

    A power controller device is disclosed which uses a voltage-to-frequency converter in conjunction with a zero crossing detector to linearly and proportionally control AC power being supplied to a load. The output of the voltage-to frequency converter controls the ``reset`` input of a R-S flip flop, while an ``0`` crossing detector controls the ``set`` input. The output of the flip flop triggers a monostable multivibrator controlling the SCR or TRIAC firing circuit connected to the load. Logic gates prevent the direct triggering of the multivibrator in the rare instance where the ``reset`` and ``set`` inputs of the flip flop are in coincidence. The control circuit can be supplemented with a control loop, providing compensation for line voltage variations. 9 figs.

  17. 21 CFR 866.2180 - Manual colony counter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual colony counter. 866.2180 Section 866.2180...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2180 Manual colony counter. (a) Identification. A manual colony counter is a device intended for medical purposes that...

  18. Track reconstruction in the BESⅢ muon counter

    Institute of Scientific and Technical Information of China (English)

    LIANG Yu-Tie; LIU Kun; YOU Zheng-Yun; MAO Ya-Jun; LI Wei-Dong; BIAN Jian-Ming; CAO Guo-Fu; CAO Xue-Xiang; CHEN Shen-Jian; DENG Zi-Yan; FU Cheng-Dong; GAO Yuan-Ning; HAN Lei; HAN Shao-Qing; HE Kang-Lin; HE Miao; HU Ji-Feng; HU Xiao-Wei; HUANG Bin; HUANG Xing-Tao; JIA Lu-Kui; JI Xiao-Bin; LI Hai-Bo; LIU Bei-Jiang; LIU Chun-Xiu; LIU Huai-Min; LIU Ying; LIU Yong; LUO Tao; Lü Qi-Wen; MA Qiu-Mei; MA Xiang; MAO Ze-Pu; MO Xiao-Hu; NING Fei-Peng; PING Rong-Gang; QIU Jin-Fa; SONG Wen-Bo; SUN Sheng-Sen; SUN Xiao-Dong; SUN Yong-Zhao; TIAN Hao-Lai; WANG Ji-Ke; WANG Liang-Liang; WEN Shuo-Pin; WU Ling-Hui; WU Zhi; XIE Yu-Guang; XU Min; YAN Jie; YAN Liang; YAO Jian; YUAN Chang-Zheng; YUAN Ye; ZHANG Chang-Chun; ZHANG Jian-Yong; ZHANG Lei; ZHANG Xue-Yao; ZHANG Yao; ZHENG Yang-Heng; ZHU Yong-Sheng; ZOU Jia-Heng

    2009-01-01

    The reconstruction algorithm for BESⅢ Muon Counter, MucRecAlg, is developed with the object-oriented language C++ in BESⅢ offline software environment. MucRecAlg consists of the following functions: to find track seeds either from extrapolation of tracks in the main drift chamber or from the fired strips in muon counter, to select fired strips associated to the candidate tracks, to fit the candidate tracks with a linear or quadratic function and to calculate other parameters of the tracks for muon identification. Monte Carlo samples are generated to check the performance of the reconstruction package, such as reconstruction efficiency, muon remaining rate and pion rejection rate, etc. The preliminary results show that the pion rejection rate is around 3%-4% while the muon remaining rate is better than 90% in 0.4-1.6 GeV/c momentum region, which meets the requirement as shown in the design report.

  19. Exact tests for Hardy-Weinberg proportions.

    Science.gov (United States)

    Engels, William R

    2009-12-01

    Exact conditional tests are often required to evaluate statistically whether a sample of diploids comes from a population with Hardy-Weinberg proportions or to confirm the accuracy of genotype assignments. This requirement is especially common when the sample includes multiple alleles and sparse data, thus rendering asymptotic methods, such as the common chi(2)-test, unreliable. Such an exact test can be performed using the likelihood ratio as its test statistic rather than the more commonly used probability test. Conceptual advantages in using the likelihood ratio are discussed. A substantially improved algorithm is described to permit the performance of a full-enumeration exact test on sample sizes that are too large for previous methods. An improved Monte Carlo algorithm is also proposed for samples that preclude full enumeration. These algorithms are about two orders of magnitude faster than those currently in use. Finally, methods are derived to compute the number of possible samples with a given set of allele counts, a useful quantity for evaluating the feasibility of the full enumeration procedure. Software implementing these methods, ExactoHW, is provided.

  20. Prevent: A Fragmented Counter-Terrorism Strategy

    Science.gov (United States)

    2015-05-21

    of the Prevent strategy. The British counter-insurgency experiences in Malaysia provide an invaluable insight into the historical lessons of...cultural diversity , and language are recognized, it becomes easier to appreciate why a separation from the rest of the United Kingdom’s society is...autonomy in Malaysia reflect a similar dichotomy that the OSCT and DCLG face today. The Prevent strategy of decentralized control and emphasis on local

  1. Light Obscuration Particle Counter Fuel Contamination Limits

    Science.gov (United States)

    2015-10-08

    4) (5). The Army utilizes ASTM D4176 – Standard Test Method for Free Water and Particulate Contamination in Distillate Fuels (Visual Inspection ...where high in the 4µm (c) channel only. 78 samples where aviation fuels (JP-8 and F-24) that where high in the 6µm (c),14µm (c), and/or 30µm (c...AND USE OF LIQUID FUELS Charleston, South Carolina USA 4-8 October 2015 LIGHT OBSCURATION PARTICLE COUNTER FUEL CONTAMINATION LIMITS Joel

  2. Infection Counter: Automated Quantification of in Vitro Virus Replication by Fluorescence Microscopy

    Directory of Open Access Journals (Sweden)

    Siân Culley

    2016-07-01

    Full Text Available The ability to accurately and reliably quantify viral infection is essential to basic and translational virology research. Here, we describe a simple and robust automated method for using fluorescence microscopy to estimate the proportion of virally infected cells in a monolayer. We provide details of the automated analysis workflow along with a freely available open-source ImageJ plugin, Infection Counter, for performing image quantification. Using hepatitis C virus (HCV as an example, we have experimentally verified our method, demonstrating that it is equivalent, if not better, than the established focus-forming assay. Finally, we used Infection Counter to assess the anti-HCV activity of SMBz-CsA, a non-immunosuppressive cyclosporine analogue.

  3. Rapid method for determining Sr-89 and Sr-90 using Cherenkov and proportional counting; Schnellmethode zur Bestimmung von SR-89 und SR-90 durch Cerenkov- und Proportionalzaehlermessungen

    Energy Technology Data Exchange (ETDEWEB)

    Lange, S.; Wende, C.; Schwokowski, R.; Alisch-Mark, M.; Abraham, A.; Heinrich, T. [Staatliche Betriebsgesellschaft fuer Umwelt und Landwirtschaft, Radebeul (Germany)

    2016-07-01

    A rapid method for determining Sr-89 and Sr-90 in water, milk and biological samples has been developed and tested. After sample preparation strontium is separated by extraction chromatography using Sr resin. Eluate is divided and transfered to LSC vial and filter paper by SrCO{sub 3} precipitation. A Hidex 300 SL TDCR liquid scintillation counter and Thermo Fisher low level proportional counter have been used. Chemical yield of Sr-85 tracer is determined by Gamma spectroscopy. Uncertainty budget, decision threshold and detection limit are calculated in accordance with GUM and ISO 11929.

  4. Hardware support for software controlled fast multiplexing of performance counters

    Science.gov (United States)

    Salapura, Valentina; Wisniewski, Robert W.

    2013-01-01

    Performance counters may be operable to collect one or more counts of one or more selected activities, and registers may be operable to store a set of performance counter configurations. A state machine may be operable to automatically select a register from the registers for reconfiguring the one or more performance counters in response to receiving a first signal. The state machine may be further operable to reconfigure the one or more performance counters based on a configuration specified in the selected register. The state machine yet further may be operable to copy data in selected one or more of the performance counters to a memory location, or to copy data from the memory location to the counters, in response to receiving a second signal. The state machine may be operable to store or restore the counter values and state machine configuration in response to a context switch event.

  5. Consumer Preferences for High Welfare Meat in Germany: Self-service Counter or Service Counter?

    Directory of Open Access Journals (Sweden)

    Ramona Weinrich

    2015-01-01

    Full Text Available Many people view animal welfare standards in the agricultural industry as critical and some consumers would prefer to buy high welfare meat. In order to successfully introduce high welfare meat products onto the market, some important marketing decisions must be made. Due to limited shelf space in retail outlets, niche products like high welfare meat cannot be placed both at the self-service counter and at the service counter. In order to analyze where to place it best an online survey of 642 German consumers was conducted. By means of factor and cluster analyses, consumers’ animal welfare attitudes and their preference for a point of purchase were combined. The different target groups were joint using cross tabulation analysis. The results reveal that consumers in the target group show a more positive attitude to the service counter.

  6. Counter-Narratives and the Unrehearsed Stories Counter-Terrorists Unwittingly Produce

    Directory of Open Access Journals (Sweden)

    Beatrice de Graaf

    2010-11-01

    Full Text Available Governments produce both deliberate and involuntary (and less conscious narratives when countering terrorism. The thesis of this article is that such unintended messages can be much more powerful and consequential than is realized; in fact, they can completely contradict the intended official 'counter-narrative'. To substantiate this hypothesis, the author looks at the experience of the German Federal Republic in the 1970s and beyond when state and society were confronted with the Red Army Faction (RAF and similar left-wing "revolutionaries" like those of the 2nd of June Movement or the Red Zora.

  7. A study of dentists' preferred maxillary anterior tooth width proportions: comparing the recurring esthetic dental proportion to other mathematical and naturally occurring proportions.

    Science.gov (United States)

    Ward, Daniel H

    2007-01-01

    Presently, there are no generally accepted standards for designing smiles using tooth proportion relationships. The purpose of this study was to determine whether North American dentists prefer smile designs created using the recurring esthetic dental (RED) proportion, other mathematically defined tooth proportion relationships, or naturally occurring tooth-to-tooth width proportions previously reported to occur in the North American population. Three hundred and one North American dentists were surveyed to determine their preferences of imaged smiles exhibiting different anterior tooth width proportions and the primary proportion influencing their decision. One-sample t-tests were used to compare preferences of constructed smiles. Pearson's Chi-square test was used to assess the independence of the relationship between the subjects' demographic attributes and the factors reported as being instrumental in their decision processes. Fifty-seven percent of dentists surveyed preferred the smiles with the 70% RED proportion over the smiles with the naturally occurring maxillary anterior tooth width proportions in normal-length teeth. Dentists preferred the smiles of the naturally occurring maxillary tooth proportions (70%) and the 70% RED proportion (75%) over the golden proportion. In smiles with tall teeth, the golden proportion was preferred by 58% of the surveyed dentists over the naturally occurring tooth-to-tooth width proportions as previously defined by Preston. Sixty-two percent of dentists cited the overall balance as the primary factor affecting their selection. Twenty-three percent made their selection based on the size of the maxillary central incisors, whereas 15% used other teeth or factors. Smiles created using the principles of the RED proportion were preferred by a majority of dentists surveyed. The majority of dentists reported that overall balance was the primary factor affecting their selection. The RED proportion may be useful in creating smiles

  8. PRELIMINARY PROGRAMMED WHOLE—BODY COUNTER

    Institute of Scientific and Technical Information of China (English)

    张少东; 郑文忠; 等

    1995-01-01

    It is capable of giving the initial intakes of radionuclides and the assessment quantitites used in radiation protection according to its measured results of radionuclides in vivo.It is accomplished by providing the software of controlling,interface and internal dose estimation programs to the original iron cabin shielding whole-body counter.The preliminary application shows that its data processing is rapid and correct,and can meet the requirement of rapid internal radioactive contamination monitoring and diagnosing in case of lots of internal contamination subjects happened in nuclear accident.

  9. Taxing junk food to counter obesity.

    Science.gov (United States)

    Franck, Caroline; Grandi, Sonia M; Eisenberg, Mark J

    2013-11-01

    We examined the advantages and disadvantages of implementing a junk food tax as an intervention to counter increasing obesity in North America. Small excise taxes are likely to yield substantial revenue but are unlikely to affect obesity rates. High excise taxes are likely to have a direct impact on weight in at-risk populations but are less likely to be politically palatable or sustainable. Ultimately, the effectiveness of earmarked health programs and subsidies is likely to be a key determinant of tax success in the fight against obesity.

  10. Shared address collectives using counter mechanisms

    Science.gov (United States)

    Blocksome, Michael; Dozsa, Gabor; Gooding, Thomas M; Heidelberger, Philip; Kumar, Sameer; Mamidala, Amith R; Miller, Douglas

    2014-02-18

    A shared address space on a compute node stores data received from a network and data to transmit to the network. The shared address space includes an application buffer that can be directly operated upon by a plurality of processes, for instance, running on different cores on the compute node. A shared counter is used for one or more of signaling arrival of the data across the plurality of processes running on the compute node, signaling completion of an operation performed by one or more of the plurality of processes, obtaining reservation slots by one or more of the plurality of processes, or combinations thereof.

  11. Cerenkov counter for the experiment NA3

    CERN Multimedia

    1978-01-01

    The program of the NA3 experiment included the study of hadronic interactions with a large transverse momentum pT, thus the inclusion in the set-up of three gas threshold Cerenkov counters of large acceptance. The photo shows the downstream part of the second Cerenkov (located at the output of the magnet). The yellow membrane is a temporary protection for the optics (shown in photo 7810540X) to be taken away when fixing this part to the gas tank (entering the magnet and not shown). The photomultipliers all around are heavily shielded.

  12. The multimodal argumentation of persuasive counter discourses

    DEFF Research Database (Denmark)

    Maier, Carmen Daniela

    are given prominence in the argumentation by examining their complex interplay and functional differentiation. The ways in which speech, writing and images articulate the counter discourse occupy a central position in the analysis. A special focus is put on the multimodal configuration of specific...... and new multimodal ways of discussing them. References Kress, G. 2010. Multimodality. A Social Semiotic Approach to Contemporary Communication. London: Routledge. Van Leeuwen, Theo. 2008. Discourse and Practice. New Tools for Critical Discourse Analysis. Oxford: Oxford University Press. Chouliaraki, L...

  13. Industrial espionage and technical surveillance counter measurers

    CERN Document Server

    Androulidakis, Iosif

    2016-01-01

    This book examines technical aspects of industrial espionage and its impact in modern companies, organizations, and individuals while emphasizing the importance of intellectual property in the information era. The authors discuss the problem itself and then provide statistics and real world cases. The main contribution provides a detailed discussion of the actual equipment, tools and techniques concerning technical surveillance in the framework of espionage. Moreover, they present the best practices and methods of detection (technical surveillance counter measures) as well as means of intellectual property protection.

  14. Use of miniature C-14 counters in dating and authentication in the museum

    Energy Technology Data Exchange (ETDEWEB)

    Harbottle, G.; Sayre, E.V.; Stoenner, R.W.

    1983-01-01

    Curators often do not understand the basis for the C-14 method of age determination and its limitations. Purpose of this paper is to describe the underlying principles, and how these must influence the interpretation of the radiocarbon measurement of a museum specimen in terms of age. Several techniques for that measurement are described briefly, focussing on the miniature proportional counters that were developed for the Smithsonian Institution, and three museum problems are described which were attacked, and some interesting further research on museum objects that has been proposed. Finally some projections on the future applications of the different methods are made, in the context of museum work.

  15. A new TDCR-LS counter using Channel photomultiplier tubes.

    Science.gov (United States)

    Ivan, C; Cassette, P; Sahagia, Maria

    2008-01-01

    A new Triple to Double Coincidence Ratio (TDCR) liquid scintillation (LS) counter using recently available photodetectors, the Channel photomultiplier (CPM) tubes, was constructed and tested in the framework of a scientific cooperation between IFIN-HH and LNHB. The prototype LS counter uses 3CPM tubes arranged symmetrically in an optical chamber around a standard LS vial. The behavior of the prototype was first evaluated with a light emitting diode (LED) light pulser. The counter was then compared against a TDCR counter using conventional photomultiplier tubes, by measuring (55)Fe, (3)H, (63)Ni and (90)Sr/(90)Y LS sources prepared in commercial liquid scintillation cocktails. Although the observed detection efficiency was significantly lower than the one achieved with the traditional counter, we found a remarkable agreement on the activity determination using the two counters. Details on the prototype and the measurement results obtained are discussed in this paper.

  16. Instability patterns between counter-rotating disks

    Directory of Open Access Journals (Sweden)

    F. Moisy

    2003-01-01

    Full Text Available The instability patterns in the flow between counter-rotating disks (radius to height ratio R/h from 3.8 to 20.9 are investigated experimentally by means of visualization and Particle Image Velocimetry. We restrict ourselves to the situation where the boundary layers remain stable, focusing on the shear layer instability that occurs only in the counter-rotating regime. The associated pattern is a combination of a circular chain of vortices, as observed by Lopez et al. (2002 at low aspect ratio, surrounded by a set of spiral arms, first described by Gauthier et al. (2002 in the case of high aspect ratio. Stability curve and critical modes are measured for the whole range of aspect ratios. From the measurement of a local Reynolds number based on the shear layer thickness, evidence is given that a free shear layer instability, with only weak curvature effect, is responsible for the observed patterns. Accordingly, the number of vortices is shown to scale as the shear layer radius, which results from the competition between the centrifugal effects of each disk.

  17. Silicon photomultipliers in AMIGA muon counters

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  18. The Brazilian military: its role in counter-drug activities.

    OpenAIRE

    Kitchener, Roy I.

    1992-01-01

    Approved for public release; distribution is unlimited This thesis examines the role of Brazil's military in counter-drug operations. Drug trafficking in Brazil poses a growing threat to the country's national security, but Brazil's physical size and limited resources have hindered the government's counter-drug efforts. The Brazilian military has been reluctant to assume a more significant role in counter-drug operations. The thesis argues that external, internal, and ...

  19. Hardware support for software controlled fast reconfiguration of performance counters

    Science.gov (United States)

    Salapura, Valentina; Wisniewski, Robert W.

    2013-06-18

    Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

  20. Hardware support for software controlled fast reconfiguration of performance counters

    Science.gov (United States)

    Salapura, Valentina; Wisniewski, Robert W

    2013-09-24

    Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

  1. A new highly segmented start counter for the CLAS detector

    Energy Technology Data Exchange (ETDEWEB)

    Sharabian, Y.G. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Battaglieri, M. [INFN Sezione di Genova, 16146 Genova (Italy); Burkert, V.D. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); DeVita, R. [INFN Sezione di Genova, 16146 Genova (Italy); Elouadrhiri, L. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Guo, L. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Kashy, D. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Kubarovsky, V. [Rensselaer Polytechnic Institute, Troy, NY 12180 and Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Mutchler, G.S. [T.W. Bonner Nuclear Laboratory, Rice University, Houton, TX 77251-1892 (United States)]. E-mail: mutchler@rice.edu; Ostrick, M. [Physikalisches Institut, Universitaet Bonn, Bonn (Germany); Ripani, M. [INFN Sezione di Genova, 16146 Genova (Italy); Rossi, P. [INFN Laboratori Nazionali di Frascati, 00044 Frascati (Italy); Rottura, A. [INFN Sezione di Genova, 16146 Genova (Italy); Pasyuk, E. [Arizona State University, Tempe, AZ, 85287-1504 (United States); Weygand, D. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)

    2006-01-01

    The design, construction and performance of a highly segmented Start Counter are described. The Start Counter is an integral part of the trigger used in photon beam running with CLAS in Hall B at the Thomas Jefferson National Accelerator Facility (TJNAF). The Start Counter is constructed of 24 2.2-mm-thick single-ended scintillation paddles, forming a hermetic hexagon around the target region. This device measures the interaction time of the incoming photon in the target by detecting the outgoing particles. The counter provides complex trigger topologies, shows good efficiency and achieved a time resolution of 350 ps.

  2. A critique to the significance of Gettier counter-examples

    Institute of Scientific and Technical Information of China (English)

    Cao Jianbo

    2006-01-01

    Usually,people think that Gettier counter-examples challenged the traditional tripartite definition of knowledge and fundamentally changed the characteristic of the contemporary epistemology.This paper argues that regard for Gettier counter-examples is exaggerated,because(i)the JTB definition is neither an important nor a comprehensive one that covers all knowledge.Moreover,the significance of Gettier counter-examples is limited.(ii)The source of Gettier counter-examples lies in one arbitrary judgment,two mix-ups,three false assumptions,and a misunderstanding about the JTB definition.

  3. The 12B counter: an active dosemeter for high-energy neutrons.

    Science.gov (United States)

    Leuschner, A

    2005-01-01

    High-energy accelerators can produce strong time-structured radiation fields. Such dose shots are generated at linear machines with low duty cycles as well as at circular machines when complete fills are instantaneously lost. The main dose component behind thick shielding is due to high-energy neutrons occurring at that time structure. Dosemeters based on Geiger-Mueller tubes or proportional counters fail here completely. The 12B counter, a novel dosemeter made of a plastic scintillator using carbon activation for event-like exposure, has been introduced. High-energy neutrons activate the carbon nuclei by three inelastic reactions. The decay patterns with half-lives between 20 ms and 20 min can be exploited depending on the time structure of the radiation field. The response of the 12B counter was measured along with some other dosemeters, both active and passive, in the radiation field behind the lateral concrete shielding of a 7.5 GeV proton transfer line.

  4. Mathematically modelling proportions of Japanese populations by industry

    Science.gov (United States)

    Hirata, Yoshito

    2016-10-01

    I propose a mathematical model for temporal changes of proportions for industrial sectors. I prove that the model keeps the proportions for the primary, the secondary, and the tertiary sectors between 0 and 100% and preserves their total as 100%. The model fits the Japanese historical data between 1950 and 2005 for the population proportions by industry very well. The model also predicts that the proportion for the secondary industry becomes negligible and becomes less than 1% at least around 2080.

  5. Evaluation of natural smile: Golden proportion, RED or Golden percentage

    OpenAIRE

    Murthy, B. V. Sreenivasan; Ramani, Niketa

    2008-01-01

    Creating geometric or mathematical proportion to relate the successive width of maxillary anterior teeth is a critical aspect in Esthetic dentistry. Golden proportion, recurring esthetic dental (RED) proportion and golden percentage are new theories in this field. Aim: To investigate the existence and suitability of Golden proportion, Recurring Esthetic Dental, and Golden percentage between the widths of maxillary anterior teeth in individuals with natural dentition, with the aid of digital p...

  6. Spatial Proportional Reasoning Is Associated with Formal Knowledge about Fractions

    Science.gov (United States)

    Möhring, Wenke; Newcombe, Nora S.; Levine, Susan C.; Frick, Andrea

    2016-01-01

    Proportional reasoning involves thinking about parts and wholes (i.e., about fractional quantities). Yet, research on proportional reasoning and fraction learning has proceeded separately. This study assessed proportional reasoning and formal fraction knowledge in 8- to 10-year-olds. Participants (N = 52) saw combinations of cherry juice and water…

  7. Theoretical Investigation of a Proportional-Plus-Flicker Automatic Pilot

    Science.gov (United States)

    Seaberg, Ernest C.

    1950-01-01

    The proportional-plus-flicker automatic pilot operates by a nonlinear principle whereby a fast-acting flicker servomotor response is combined with a low-speed proportional servomotor response for the purpose of obtaining supersonic stability and control. Essentially, the autopilot maintains a zero reference about which the output is proportional to the input. However, a flicker response overrides this proportional response at a fixed angle of gimbal displacement on either side of the zero gyroscope reference. Therefore, in contrast to other high speed control systems, the design requirements are simplified because the two components of the proportional-flicker control system are easy to build separately and they can be combined in a relatively simple manner. By application of the proportional-flicker principle, satisfactory stability can be obtained by the proper adjustment of the variable factors in the autopilot mechanism; namely, the proportional gain, the amplitude of flicker control deflection, the autopilot time-lag factor (the time-lag between flicker and proportional operation), and the point in the range that the autopilot switches from a flicker to a proportional system. There is a possibility that these factors can be adjusted so that a more rapid response time (the time to reach steady state) is obtained with the non-linear proportional-flicker autopilot than with a purely linear proportional autopilot. For the main part of this analysis, the proportional part of the system is approximated by a zero-phase-lag proportional autopilot with the assumption that the control surface moves instantaneously at the point where the system switches from flicker to proportional. Good correlation is shown between the results obtained by this method and results obtained by using a close approximation of an actual autopilot transfer function for proportional autopilot operation.

  8. Fiber-Optic Monitoring System of Particle Counters

    Directory of Open Access Journals (Sweden)

    A. A. Titov

    2016-01-01

    Full Text Available The article considers development of a fiber-optic system to monitor the counters of particles. Presently, optical counters of particles, which are often arranged at considerable distance from each other, are used to study the saltation phenomenon. For monitoring the counters, can be used electric communication lines.However, it complicates and raises the price of system Therefore, we offered a fiber-optic system and the counter of particles, free from these shortcomings. The difference between the offered counter of particles and the known one is that the input of radiation to the counter and the output of radiation scattering on particles are made by the optical fibers, and direct radiation is entered the optical fiber rather than is delayed by a light trap and can be used for lighting the other counters thereby allowing to use their connection in series.The work involved a choice of the quartz multimode optical fiber for communication, defining the optical fiber and lenses parameters of the counter of particles, and a selection of the radiation source and the photo-detector.Using the theory of light diffraction on a particle, a measuring range of the particle sizes has been determined. The system speed has been estimated, and it has been shown that a range of communication can reach 200km.It should be noted that modulation noise of counters of particles connected in series have the impact on the useful signal. To assess the extent of this influence we have developed a calculation procedure to illustrate that with ten counters connected in series this influence on the signal-to-noise ratio will be insignificant.Thus, it has been shown that the offered fiber-optic system can be used for monitoring the counters of particles across the desertified territories. 

  9. Modeling a Cryogenic HE3 Nuclear Gyro.

    Science.gov (United States)

    1980-12-01

    OBSOLETE UNCLASSIFIED .2 SECURITY CLASSIFICATION OF: THIS PAGE (9When Deta Entered) UNCLASSIFILD SECURIT ) CLASSIFICATION OF THIS PAGE(147 n Date Fnt...is - 4G -I theoretically possible to determine all three components of W0 with a single device. To do this three magnetometers are required, one to -*G...as to maintain a constant angle between the 3G and 31 axes as the k axis cones around the 3I axis at a frequency w rad/sec.z Then - 4G -I . G (4.1) W

  10. Over-the-Counter Medication Use, Perceived Safety, and Decision-Making Behaviors in Pregnant Women

    Directory of Open Access Journals (Sweden)

    Katie L. Kline, Pharm.D. Candidate 2011

    2011-01-01

    Full Text Available The purpose of this study was to determine which over-the-counter (OTC medications women are using during pregnancy, and to assess patients’ perceived safety of these medications. In addition, the decision-making process utilized by pregnant women when choosing OTC drug therapy was explored, including sources of information and recommendation. The subjects included pregnant women 18 years and older. Subjects were solicited as a convenience sample by providing surveys in two urban women’s clinic waiting rooms. Of the 61 respondents, 96.3% had used an OTC medication, herbal, or vitamin during their current pregnancy. The most common products included prenatal vitamins, acetaminophen, cough drops, antacids, calcium, vitamin D, and DHA. The majority of women surveyed regarded over-the-counter medications, vitamins, and herbals as “safe, but would talk to a healthcare professional before using.” The most utilized sources of drug information during pregnancy were a physician (68.9%, midwife (55.7%, and the Internet (44.3%. There were an equal number of respondents obtaining general OTC information from apharmacist as from their family and friends (26.2%. Almost all subjects had used an over-the-counter medication during their pregnancy and the majority considered OTCs safe after first consulting a healthcare professional. Although a high percentage of subjects have obtained their information and recommendations from healthcare professionals, a very small proportion of subjects had utilized a pharmacist as a resource. Being drug experts and easily accessible members of the healthcare team, pharmacists have a responsibility to aid the obstetric population in the appropriate and safe use of over-the-counter drugs, vitamins, and herbals during pregnancy.

  11. EFFECT OF COUNTERS IN PERFORMANCE OF HADOOP

    Directory of Open Access Journals (Sweden)

    Preeti Jain

    2015-10-01

    Full Text Available Recent technological advancements have led to an overflow of data from distinctive domains (e.g., health care and scientific sensors, user-generated data, Internet and financial companies, and supply chain systems over the past two decades [1]. Big data is commonly unstructured, huge in volume and require more real-time analysis. This paper discusses a Big Data problem from NCDC for huge volume of weather data collected from various parts of world. We had generated map ( and reduce ( function for solving this problem and experimental results of these applications on a Hadoop cluster are being discussed. In this paper, performance of above application has been shown with respect to some counters available.

  12. Actively suspended counter-rotating machine

    Science.gov (United States)

    Studer, Philip A. (Inventor)

    1983-01-01

    A counter-rotating machine, such as a positive displacement pump having a pair of meshed, non-contacting helical screws (10,12), subjects its rotating members to axial and radial thrust forces when used for such purposes as compression of liquid or gaseous phase fluids while transporting them through a pump cavity (11,13). Each helical screw (10,12) has a shaft (17,17') which is actively suspended at opposite ends (11a,11b) of the pump cavity by a servo-controlled magnetic bearing assembly (19) and a servo-controlled rotary drive motor (20). Both bearing assemblies and drive motors are mounted on the outside of the pump cavity (11,13). Opto-electric angular position sensors (250) provide synchronization between radial orientation of the drive motors. The bearing assemblies and drive motors conjugately provide axial stabilization and radial centering of the helical screws during volumetric compression of aspirated liquid or gaseous phase fluids.

  13. Over-the-counter analgesic use.

    Science.gov (United States)

    De Broe, Marc E; Elseviers, Monique M

    2009-10-01

    Chronic analgesic nephropathy, particularly chronic interstitial nephritis and renal papillary necrosis, results from daily use for many years of mixtures containing at least two analgesics and caffeine or dependence-inducing drugs. Computed tomography scan can accurately diagnose this disease even in the absence of reliable information on previous analgesic use. The occasion to moderate regular use of aspirin and nonsteroidal anti-inflammatory drugs is without renal risk when renal function is normal. Paracetamol use is less clear although the risk is not great. The continued use of non-phenacetin-combined analgesics with or without nonsteroidal anti-inflammatory drugs is associated with faster progression toward renal impairment. As long as high-risk analgesic mixtures are available over the counter, analgesic nephropathy will continue to be a problem.

  14. The multimodal argumentation of persuasive counter discourses

    DEFF Research Database (Denmark)

    Maier, Carmen Daniela

    with the characteristics and potential fallacies of the advertising discourse of commercials. The original advertising discourse is deconstructed and reconstructed with additional visual material in front of the viewers’ eyes who are instructed by a voiceover narrator what to look at and how to identify and decode...... and critical participants in the process of message understanding. In this paper, I explore the Media Bites videos that identify and discuss problematic gender issues in commercials advertising various products. I adopt a multimodal approach in my discourse analysis and I establish which semiotic modes...... are given prominence in the argumentation by examining their complex interplay and functional differentiation. The ways in which speech, writing and images articulate the counter discourse occupy a central position in the analysis. A special focus is put on the multimodal configuration of specific...

  15. 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.

  16. The Counter Terrorist Classroom: Religion, Education, and Security

    Science.gov (United States)

    Gearon, Liam

    2013-01-01

    The article identifies international cases--from the United States, Europe, and the United Nations--of an emergent interface of religion, education, and security. This is manifest in the uses of religion in education to counter religious extremism, the notional "counter terrorist classroom." To avoid an over-association of extremism with religion,…

  17. Majorizational Choosing of SeveralDifferent Fuzzy Counter Operator

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Different fuzzy reasoning methods were made by choosing different fuzzy operater. This article generally introduced the basic structure of fuzzy controller ,and gave several different fuzzy controllers ,and compared and analyzed different fuzzy counters in theory and computer simulating control and realized majorizational choosing of several fuzzy counters.

  18. Counter-terrorism strategies in Indonesia, Algeria and Saudi Arabia

    NARCIS (Netherlands)

    Meijer, R.; Hasan, Noorhaidi; Hendriks, B.; Janssen, F.

    2012-01-01

    This report is the result of a year-long study, conducted from March 2010 to March 2011, of the counter-terrorist strategies of three countries: Indonesia, Algeria and Saudi Arabia. The aim of this study was to acquire insight into the counter-terrorist strategies of these countries, to analyse them

  19. VLSI Architecture Of A Binary Up/Down Counter

    Science.gov (United States)

    Hsu, In-Shek; Truong, Trieu-Kie; Reed, I. S.

    1988-01-01

    Identical stages contain relatively-few logic gates. New algorithm simplifies design of binary up/down counter. Design suitable for very-large-scale integrated circuits. Contains simple "pipeline" array of identical cells. Programmable logic unit converts increment and decrement input signals to "U" and "D" signals required by algorithm of counter.

  20. The Counter Terrorist Classroom: Religion, Education, and Security

    Science.gov (United States)

    Gearon, Liam

    2013-01-01

    The article identifies international cases--from the United States, Europe, and the United Nations--of an emergent interface of religion, education, and security. This is manifest in the uses of religion in education to counter religious extremism, the notional "counter terrorist classroom." To avoid an over-association of extremism with…

  1. Dirty Fighting: How to Counter Total Warfare Mentality

    Science.gov (United States)

    2015-06-12

    DIRTY FIGHTING: HOW TO COUNTER TOTAL WARFARE MENTALITY A thesis presented to the Faculty of the U.S. Army Command and...to Counter Total Warfare Mentality Approved by: , Thesis Committee Chair LTC Sandra J. Sanchez, MBA , Member Marlyn R. Pierce...

  2. Lessons from History for Counter- Terrorism Strategic Communications

    NARCIS (Netherlands)

    Ingram, H.J.; Reed, A.G.

    2016-01-01

    Drawing on the Counter-terrorism Strategic Communication (CTSC) Project’s research paper “A Brief History of Propaganda during Conflict“, this Policy Brief lays out the key policy-relevant lessons for developing effective counter-terrorism strategic communications. It presents a framework of

  3. The Counter Terrorist Classroom: Religion, Education, and Security

    Science.gov (United States)

    Gearon, Liam

    2013-01-01

    The article identifies international cases--from the United States, Europe, and the United Nations--of an emergent interface of religion, education, and security. This is manifest in the uses of religion in education to counter religious extremism, the notional "counter terrorist classroom." To avoid an over-association of extremism with…

  4. Recent results on aerogel development for use in Cherenkov counters

    Energy Technology Data Exchange (ETDEWEB)

    Danilyuk, A.F. E-mail: danilyuk@catalysis.nsk.su; Kirillov, V.L.; Savelieva, M.D.; Bobrovnikov, V.S.; Buzykaev, A.R.; Kravchenko, E.A.; Lavrov, A.V.; Onuchin, A.P

    2002-11-21

    Synthesis of silica aerogel for Cherenkov counters is being studied for more than 10 years at the Boreskov Institute of Catalysis in collaboration with the Budker Institute of Nuclear Physics. Index of refraction, light scattering length and light absorption length are optical characteristics which determine the quality of aerogel Cherenkov counter. These parameters were measured for the aerogel produced. The results are presented.

  5. Recent results on aerogel development for use in Cherenkov counters

    CERN Document Server

    Danilyuk, A F; Savelieva, M D; Bobrovnikov, V S; Buzykaev, A R; Kravchenko, E A; Lavrov, A V; Onuchin, A P

    2002-01-01

    Synthesis of silica aerogel for Cherenkov counters is being studied for more than 10 years at the Boreskov Institute of Catalysis in collaboration with the Budker Institute of Nuclear Physics. Index of refraction, light scattering length and light absorption length are optical characteristics which determine the quality of aerogel Cherenkov counter. These parameters were measured for the aerogel produced. The results are presented.

  6. Counter-Buffing: A Visual Criticism of Guerrilla Advertising

    Science.gov (United States)

    Lauzon, Robb Conrad; Cooke, Laquana

    2017-01-01

    This article addresses and explores hip-hop's reclamation of space using transit as a public bulletin. It is situated within counter-publics discourse and couched in the theoretical frameworks offered by visual rhetorical theory. This article also discusses hip-hop counter-publics through guerrilla advertising by former graffiti artists, SKI and…

  7. Counter-terrorism strategies in Indonesia, Algeria and Saudi Arabia

    NARCIS (Netherlands)

    Meijer, R.; Hasan, Noorhaidi; Hendriks, B.; Janssen, F.

    2012-01-01

    This report is the result of a year-long study, conducted from March 2010 to March 2011, of the counter-terrorist strategies of three countries: Indonesia, Algeria and Saudi Arabia. The aim of this study was to acquire insight into the counter-terrorist strategies of these countries, to analyse

  8. Counter design influences the privacy of patients in health care

    NARCIS (Netherlands)

    Mobach, Mark P.

    2009-01-01

    A re-furnishing of counter areas in primary health care was used to assess patient privacy and its influences on the nature of conversations in a controlled experiment. Patients in two community-based pharmacies in the Netherlands were assigned to enclosed counters and a queue at distance, or to cou

  9. The IFIN-HH triple coincidence liquid scintillation counter

    CSIR Research Space (South Africa)

    Razdolescu, AC

    2006-10-01

    Full Text Available at IFIN-HH using a 3 H standard. The performances of the IFIN-HH TDCR counter was checked against the measurement results of the TDCR counters of CSIR NML (South Africa), RC (Poland) and LNHB (France). A set of ready-to-measure Ni-63 sources in liquid...

  10. Dosimetric Response to Gamma-rays and Neutrons of a Tissue-equivalent Microstrip Gas Counter

    Energy Technology Data Exchange (ETDEWEB)

    Dubeau, J.; Waker, A.J.; Biggar, M.; Rayner, M.D.; Sommerville, E.W.; Welch, S.E

    2000-07-01

    In recent years a new generation of tracking particle detectors has been developed for particle physics experiments. One such detector, the microstrip gas counter (MSGC) is similar to the multiwire proportional chamber but consists of fine strips of metal on a substrate rather than suspended wires. The main feature of this device is the sub-millimetre readout spacing. When filled with tissue-equivalent (TE) gas at low pressure and constructed of TE materials, such a device may easily be configured to simulate submicron tissue site sizes. In this work, the microdosimetric response of this 'TE-MSGC' to photons and neutron in the range of 100 keV to 14.8 MeV is investigated. It is demonstrated through measurements and Monte Carlo simulations that, despite having a sampling region of unusual shape for a tissue-equivalent proportional counter (TEPC) based dose equivalent meter, the TE-MSGC provides very good estimates of the ICRU-57 quantities of interest, i.e. H*(10) and (Q). (author)

  11. Measurements of the Electric Form Factor of the Neutron up to Q2=3.4 GeV2 using the Reaction He3(e,e'n)pp

    CERN Document Server

    Riordan, S; Craver, B; Kelleher, A; Kolarkar, A; Miller, J; Cates, G D; Liyanage, N; Wojtsekhowski, B; Acha, A; Allada, K; Anderson, B; Aniol, K A; Annand, J R M; Arrington, J; Averett, T; Beck, A; Bellis, M; Boeglin, W; Breuer, H; Calarco, J R; Camsonne, A; Chen, J P; Chudakov, E; Coman, L; Crowe, B; Cusanno, F; Day, D; Degtyarenko, P; Dolph, P A M; Dutta, C; Ferdi, C; Fernandez-Ramirez, C; Feuerbach, R; Fraile, L M; Franklin, G; Frullani, S; Fuchs, S; Garibaldi, F; Gevorgyan, N; Gilman, R; Glamazdin, A; Gomez, J; Grimm, K; Hansen, J O; Herraiz, J L; Higinbotham, D W; Holmes, R; Holmstrom, T; Howell, D; deJager, C W; Jiang, X; Jones, M K; Katich, J; Kaufman, L J; Khandaker, M; Kelly, J J; Kiselev, D; Korsch, W; LeRose, J; Lindgren, R; Markowitz, P; Margaziotis, D J; Beck, S May-Tal; Mayilyan, S; McCormick, K; Meziani, Z E; Michaels, R; Moffit, B; Nanda, S; Nelyubin, V; Ngo, T; Nikolenko, D M; Norum, B; Pentchev, L; Perdrisat, C F; Piasetzky, E; Pomatsalyuk, R; Protopopescu, D; Puckett, A J R; Punjabi, V A; Qian, X; Qiang, Y; Quinn, B; Rachek, I; Ransome, R D; Reimer, P E; Reitz, B; Roche, J; Ron, G; Rondon, O; Rosner, G; Saha, A; Sargsian, M; Sawatzky, B; Segal, J; Shabestari, M; Shahinyan, A; Shestakov, Yu; Singh, J; Sirca, S; Souder, P; Stepanyan, S; Stibunov, V; Sulkosky, V; Tajima, S; Tobias, W A; Udias, J M; Urciuoli, G M; Vlahovic, B; Voskanyan, H; Wang, K; Wesselmann, F R; Vignote, J R; Wood, S A; Wright, J; Yao, H; Zhu, X

    2010-01-01

    The electric form factor of the neutron was determined from studies of the reaction He3(e,e'n)pp in quasi-elastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the Q2-range over which it is known, we find GEn = 0.0225 +/- 0.0017 (stat) +/- 0.0024 (syst), 0.0200 +/- 0.0023 +/- 0.0018, and 0.0142 +/- 0.0019 +/- 0.0013 for Q2 = 1.72, 2.48, and 3.41 GeV2, respectively.

  12. Determination of solar flare accelerated ion angular distributions from SMM gamma ray and neutron measurements and determination of the He-3/H ratio in the solar photosphere from SMM gamma ray measurements

    Science.gov (United States)

    Lingenfelter, Richard E.

    1989-01-01

    Comparisons of Solar Maximum Mission (SMM) observations of gamma-ray line and neutron emission with theoretical calculation of their expected production by flare accelerated ion interactions in the solar atmosphere have led to significant advances in the understanding of solar flare particle acceleration and interaction, as well as the flare process itself. These comparisons have enabled the determination of, not only the total number and energy spectrum of accelerated ions trapped at the sun, but also the ion angular distribution as they interact in the solar atmosphere. The Monte Carlo program was modified to include in the calculations of ion trajectories the effects of both mirroring in converging magnetic fields and of pitch angle scattering. Comparing the results of these calculations with the SMM observations, not only the angular distribution of the interacting ions can be determined, but also the initial angular distribution of the ions at acceleration. The reliable determination of the solar photospheric He-3 abundance is of great importance for understanding nucleosynthesis in the early universe and its implications for cosmology, as well as for the study of the evolution of the sun. It is also essential for the determinations of the spectrum and total number of flare accelerated ions from the SMM/GRS gamma-ray line measurements. Systematic Monte Carlo calculations of the time dependence were made as a function of the He-3 abundance and other variables. A new series of calculations were compared for the time-dependent flux of 2.223 MeV neutron capture line emission and the ratio of the time-integrated flux in the 2.223 MeV line to that in the 4.1 to 6.4 MeV nuclear deexcitation band.

  13. Design of a novel quantum reversible ternary up-counter

    Science.gov (United States)

    Houshmand, Pouran; Haghparast, Majid

    2015-08-01

    Reversible logic has been recently considered as an interesting and important issue in designing combinational and sequential circuits. The combination of reversible logic and multi-valued logic can improve power dissipation, time and space utilization rate of designed circuits. Only few works have been reported about sequential reversible circuits and almost there are no paper exhibited about quantum ternary reversible counter. In this paper, first we designed 2-qutrit and 3-qutrit quantum reversible ternary up-counters using quantum ternary reversible T-flip-flop and quantum reversible ternary gates. Then we proposed generalized quantum reversible ternary n-qutrit up-counter. We also introduced a new approach for designing any type of n-qutrit ternary and reversible counter. According to the results, we can conclude that applying second approach quantum reversible ternary up-counter is better than the others.

  14. Electrovacuum Static Counter-Rotating Relativistic Dust Disks

    CERN Document Server

    González, G A

    2002-01-01

    A detailed study of the Counter-Rotating Model (CRM) for generic electrostatic (magnetostatic) axially symmetric thin disks without radial pressure is presented. We find a general constraint over the counter-rotating tangential velocities needed to cast the surface energy-momentum tensor of the disk as the superposition of two counter-rotating charged dust fluids. We then show that this constraint is satisfied if we take the two counter-rotating streams as circulating along electrogeodesics with equal and opposite tangential velocities. We also find explicit expressions for the energy densities, electrostatic (magnetostatic) charge densities and velocities of the counter-rotating fluids. Three specific examples are considered where we obtain some CRM well behaved based in simple solutions to the Einstein-Maxwell equations. The considered solutions are Reissner-Nordstrom in the electrostatic case, its magnetostatic counterpart and two solutions obtained from Taub-NUT and Kerr solutions.

  15. DESIGN OF TERNARY COUNTER BASED ON ADIABATIC DOMINO CIRCUIT

    Institute of Scientific and Technical Information of China (English)

    Yang Qiankun; Wang Pengjun; Zheng Xuesong

    2013-01-01

    By researching the ternary counter and low power circuit design method,a novel design of low power ternary Domino counter on switch-level is proposed.Firstly,the switch-level structure expression of ternary loop operation circuit with enable pin is derived according to the switch-signal theory,and the one bit ternary counter is obtained combining the ternary adiabatic Domino literal operation circuit and buffer.Then the switch-level structure expression of enable signal circuit is derived,and the four bits ternary counter is obtained by cascade connection.Finally,the circuit is simulated by Spice tool and the output waveforms transform in proper order indicating that the logic function is correct.The energy consumption of the four bits ternary adiabatic Domino counter is 63% less than the conventional Domino counterpart.

  16. Investigation of Adding Proportion of RAP in Recycled Asphalt Mixture

    Directory of Open Access Journals (Sweden)

    Cao He

    2016-01-01

    Full Text Available According to the relationship between gradation and proportion of Reclaimed Asphalt Pavement (RAP and design gradation of recycled mixture, the authors discussed the influence of proportion of RAP on gradation adjustment of recycled mixture. And then, recycled mixture with 0%, 30%, 50%, 70% of RAP were made, and Influence of proportion of RAP on high and low temperature performance, water stability and anti-aging performance of recycled mixture were discussed. The results and analysis indicate that gradation of recycled mixture would not be adjusted to aiming gradation if proportion of RAP was too big. With the increase of proportion of RAP, high temperature performance and anti-aging performance of recycled mixture enhanced, but low temperature performance and water stability decayed sharply. In practical application, reasonable proportion of RAP should be determined according to gradation, performance demand and economy of recycled mixture.

  17. Pressure control valve using proportional electro-magnetic solenoid actuator

    Energy Technology Data Exchange (ETDEWEB)

    Yun, So Nam; Ham, Young Bog; Park, Pyoung Won [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2006-10-15

    This paper presents an experimental characteristics of electro-hydraulic proportional pressure control valve. In this study, poppet and valve body which are assembled into the proportional solenoid were designed and manufactured. The constant force characteristics of proportional solenoid actuator in the control region should be independent of the plunger position in order to be used to control the valve position in the fluid flow control system. The stroke-force characteristics of the proportional solenoid actuator is determined by the shape (or parameters) of the control cone. In this paper, steady state and transient characteristics of the solenoid actuator for electro-hydraulic proportional valve are analyzed using finite element method and it is confirmed that the proportional solenoid actuator has a constant attraction force in the control region independently on the stroke position. The effects of the parameters such as control cone length, thickness and taper length are also discussed.

  18. Measurements of proportional scintillation in liquid xenon using thin wires

    CERN Document Server

    Aprile, E; Goetzke, L W; Fernandez, A J Melgarejo; Messina, M; Naganoma, J; Plante, G; Rizzo, A; Shagin, P; Wall, R

    2014-01-01

    Proportional scintillation in liquid xenon has a promising application in the field of direct dark matter detection, potentially allowing for simpler, more sensitive detectors. However, knowledge of the basic properties of the phenomenon as well as guidelines for its practical use are currently limited. We report here on measurements of proportional scintillation light emitted in liquid xenon around thin wires. The maximum proportional scintillation gain of $287^{+97}_{-75}$ photons per drift electron was obtained using 10 $\\mu$m diameter gold plated tungsten wire. The thresholds for electron multiplication and proportional scintillation are measured as $725^{+48}_{-139}$ and $412^{+10}_{-133}$ kV/cm, respectively. The threshold for proportional scintillation is in good agreement with a previously published result, while the electron multiplication threshold represents a novel measurement. A complete set of parameters for the practical use of the electron multiplication and proportional scintillation processe...

  19. The proportionality as legal limit the right negotiating

    Directory of Open Access Journals (Sweden)

    Lucas Augusto da Silva Zolet

    2015-06-01

    Full Text Available This paper proposes a maximum of proportionality study and its maximum partial, especially of the Negotiating law perspective and in the sphere of legal limitation for proportionality in the practice of commercial freedoms. The constant use of the maximum of proportionality, as the basis of judicial decisions without proper methodological rigor, triggers a debate about the use of the Theory of Fundamental Rights as a mere rhetorical reference, including criticism of an incomplete legal basis of the principle of proportionality, which by means of judicial decisions can take on a different character or subverted that provided in the doctrine of Robert Alexy.     

  20. Evaluation of natural smile: Golden proportion, RED or Golden percentage.

    Science.gov (United States)

    Murthy, B V Sreenivasan; Ramani, Niketa

    2008-01-01

    Creating geometric or mathematical proportion to relate the successive width of maxillary anterior teeth is a critical aspect in Esthetic dentistry. Golden proportion, recurring esthetic dental (RED) proportion and golden percentage are new theories in this field. To investigate the existence and suitability of Golden proportion, Recurring Esthetic Dental, and Golden percentage between the widths of maxillary anterior teeth in individuals with natural dentition, with the aid of digital photographs and computer analysis. Standardized frontal images of 56 dental students, 20 male and 36 female, were captured. Each maxillary anterior tooth was digitally measured. Once the measurements were recorded, the three theories were applied and the data was analyzed statistically. The golden proportion was found to exist only in 14-25% of the subjects, between perceived maxillary anterior teeth in natural dentition. The value of RED proportion was not constant, and as one moved distally, this proportion gradually increased. Furthermore, the results revealed that golden percentage was rather constant in terms of relative tooth width. Central incisor represented 22%, lateral incisor 15% and canine 13% of the width of six maxillary anterior teeth, as viewed from the front. Both golden proportion and RED proportion are unsuitable methods to relate the successive width of the maxillary anterior teeth in natural dentition. However, the golden percentage theory can be applied if percentages are adjusted, taking into consideration the ethnicity of the population.

  1. Counter-Rotating Tandem Motor Drilling System

    Energy Technology Data Exchange (ETDEWEB)

    Kent Perry

    2009-04-30

    Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger

  2. Counter-terrorism threat prediction architecture

    Science.gov (United States)

    Lehman, Lynn A.; Krause, Lee S.

    2004-09-01

    This paper will evaluate the feasibility of constructing a system to support intelligence analysts engaged in counter-terrorism. It will discuss the use of emerging techniques to evaluate a large-scale threat data repository (or Infosphere) and comparing analyst developed models to identify and discover potential threat-related activity with a uncertainty metric used to evaluate the threat. This system will also employ the use of psychological (or intent) modeling to incorporate combatant (i.e. terrorist) beliefs and intent. The paper will explore the feasibility of constructing a hetero-hierarchical (a hierarchy of more than one kind or type characterized by loose connection/feedback among elements of the hierarchy) agent based framework or "family of agents" to support "evidence retrieval" defined as combing, or searching the threat data repository and returning information with an uncertainty metric. The counter-terrorism threat prediction architecture will be guided by a series of models, constructed to represent threat operational objectives, potential targets, or terrorist objectives. The approach would compare model representations against information retrieved by the agent family to isolate or identify patterns that match within reasonable measures of proximity. The central areas of discussion will be the construction of an agent framework to search the available threat related information repository, evaluation of results against models that will represent the cultural foundations, mindset, sociology and emotional drive of typical threat combatants (i.e. the mind and objectives of a terrorist), and the development of evaluation techniques to compare result sets with the models representing threat behavior and threat targets. The applicability of concepts surrounding Modeling Field Theory (MFT) will be discussed as the basis of this research into development of proximity measures between the models and result sets and to provide feedback in support of model

  3. COUNTER-PUNISHMENT, COMMUNICATION AND COOPERATION AMONG PARTNERS

    Directory of Open Access Journals (Sweden)

    Giulia eAndrighetto

    2016-04-01

    Full Text Available We study how communication affects cooperation in an experimental public goods environment with punishment and counter-punishment opportunities. Participants interacted over thirty rounds in fixed groups with fixed identifiers that allowed them to trace other group members’ behavior over time. The two dimensions of communication we study are asking for a specific contribution level and having to express oneself when choosing to counter-punish. We conduct four experimental treatments, all involving a contribution stage, a punishment stage and a counter-punishment stage in each round. In the first treatment communication is not possible at any of the stages. The second treatment allows participants to ask for a contribution level at the punishment stage and in the third treatment participants are required to send a message if they decide to counter-punishment. The fourth combines the two communication channels of the second and third treatments. We find that the three treatments involving communication at any of the two relevant stages lead to significantly higher contributions than the baseline treatment. We find no difference between the three treatments with communication. We also relate our results to previous results from treatments without counter-punishment opportunities and do not find that the presence of counter-punishment leads to lower cooperation level. The overall pattern of results shows that given fixed identifiers the key factor is the presence of communication. Whenever communication is possible contributions and earnings are higher than when it is not, regardless of counter-punishment opportunities.

  4. Effect of Counter Electrode in Electroformation of Giant Vesicles

    Directory of Open Access Journals (Sweden)

    Shuuhei Oana

    2011-11-01

    Full Text Available Electroformation of cell-sized lipid membrane vesicles (giant vesicles, GVs, from egg yolk phosphatidylcholine, was examined varying the shape of the counter electrode. Instead of a planar ITO (indium tin oxide electrode commonly used, platinum wire mesh was employed as a counter electrode facing lipid deposit on a planar formation electrode. The modification did not significantly alter GV formation, and many GVs of 30–50 µm, some as large as 100 µm, formed as with the standard setup, indicating that a counter electrode does not have to be a complete plane. When the counter electrode was reduced to a set of two parallel platinum wires, GV formation deteriorated. Some GVs formed, but only in close proximity to the counter electrode. Lower electric voltage with this setup no longer yielded GVs. Instead, a large onion-like multilamellar structure was observed. The deteriorated GV formation and the formation of a multilamellar structure seemed to indicate the weakened effect of the electric field on lipid deposit due to insufficient coverage with a small counter electrode. Irregular membranous objects formed by spontaneous swelling of lipid without electric voltage gradually turned into multilamellar structure upon following application of voltage. No particular enhancement of GV formation was observed when lipid deposit on a wire formation electrode was used in combination with a large planar counter electrode.

  5. Particle size dependent response of aerosol counters

    Science.gov (United States)

    Ankilov, A.; Baklanov, A.; Colhoun, M.; Enderle, K.-H.; Gras, J.; Julanov, Yu.; Kaller, D.; Lindner, A.; Lushnikov, A. A.; Mavliev, R.; McGovern, F.; O'Connor, T. C.; Podzimek, J.; Preining, O.; Reischl, G. P.; Rudolf, R.; Sem, G. J.; Szymanski, W. W.; Vrtala, A. E.; Wagner, P. E.; Winklmayr, W.; Zagaynov, V.

    During an international workshop at the Institute for Experimental Physics of the University of Vienna, Austria, which was coordinated within the Committee on Nucleation and Atmospheric Aerosols (IAMAS-IUGG), 10 instruments for aerosol number concentration measurement were studied, covering a wide range of methods based on various different measuring principles. In order to investigate the detection limits of the instruments considered with respect to particle size, simultaneous number concentration measurements were performed for monodispersed aerosols with particle sizes ranging from 1.5 to 50 nm diameter and various compositions. The instruments considered show quite different response characteristics, apparently related to the different vapors used in the various counters to enlarge the particles to an optically detectable size. A strong dependence of the 50% cutoff diameter on the particle composition in correlation with the type of vapor used in the specific instrument was found. An enhanced detection efficiency for ultrafine hygroscopic sodium chloride aerosols was observed with water operated systems, an analogous trend was found for n-butanol operated systems with nonhygroscopic silver and tungsten oxide particles.

  6. Training options for countering nuclear smuggling

    Energy Technology Data Exchange (ETDEWEB)

    Ball, D Y; Erickson, S A

    1999-07-01

    The burden of stopping a nuclear smuggling attempt at the border rests most heavily on the front-line customs inspector. He needs to know how to use the technological tools at his disposal, how to discern tell-tale anomalies in export documents and manifests, how to notice psychological signs of a smuggler's tension, and how to search anything that might hide nuclear material. This means that assistance in the counter-nuclear smuggling training of customs officers is one of the most critical areas of help that the United States can provide. This paper discusses the various modes of specialized training, both in the field and in courses, as well as the types of assistance that can be provided. Training for nuclear customs specialists, and supervisors and managers of nuclear smuggling detection systems is also important, and differs from front-line inspector training in several aspects. The limitations of training and technological tools such as expert centers that will overcome these limitations are also discussed. Training assistance planned by DOE/NN-43 to Russia within the Second Line of Defense program is discussed in the light of these options, and future possibilities for such training are projected.

  7. Over-the-Counter Medications in Pregnancy.

    Science.gov (United States)

    Servey, Jessica; Chang, Jennifer

    2014-10-15

    Many pregnant women take over-the-counter (OTC) medications despite the absence of randomized controlled trials to guide their use during pregnancy. Most data come from case-control and cohort studies. In 1979, the U.S. Food and Drug Administration began reviewing all prescription and OTC medications to develop risk categories for use in pregnancy. Most OTC medications taken during pregnancy are for allergy, respiratory, gastrointestinal, or skin conditions, as well as for general analgesia. Acetaminophen, which is used by about 65% of pregnant women, is generally considered safe during any trimester. Cold medications are also commonly used and are considered safe for short-term use outside of the first trimester. Many gastrointestinal medications are now available OTC. Histamine H2 blockers and proton pump inhibitors have not demonstrated significant fetal effects. Nonsteroidal anti-inflammatory drugs are generally not recommended in pregnancy, especially during organogenesis and in the third trimester. There are even fewer data regarding use of individual herbal supplements. Ginger is considered safe and effective for treating nausea in pregnancy. Topical creams are considered safe based on small studies and previous practice. All OTC medication use should be discussed with patients, and the effects of the symptoms should be balanced with the risks and benefits of each medication. Because of the expanding OTC market, formalized studies are warranted for patients to make a safe and informed decision about OTC medication use during pregnancy.

  8. A Multiaxial Low Cycle Fatigue Life Prediction Model for Both Proportional and Non-proportional Loading Conditions

    Science.gov (United States)

    Paul, Surajit Kumar

    2014-09-01

    This paper has presented a life prediction model in the field of multiaxial low-cycle fatigue. The proposed model is generally applied for constant amplitude multiaxial proportional and non-proportional loading. Depending upon applied strain path the equivalent strain varies within a cycle. Equivalent average strain amplitude is considered as fatigue damage parameter in the proposed model. The model has requirement of only two material constants and no other tuning parameters. The model is examined by the proportional and non-proportional low-cycle fatigue life experimental data for eight different types of materials. The model is successfully correlated with multiaxial fatigue lives of eight different materials.

  9. The principle of proportionality and European contract law

    NARCIS (Netherlands)

    Cauffman, C.; Rutgers, J.; Sirena, P.

    2015-01-01

    The paper investigates the role of the principle of proportionality within contract law, in balancing the rights and obligations of the contracting parties. It illustrates that the principle of proportionality is one of the general principles which govern contractual relations, and as such it is an

  10. The principle of proportionality and European contract law

    NARCIS (Netherlands)

    Cauffman, C.; Rutgers, J.; Sirena, P.

    2015-01-01

    The paper investigates the role of the principle of proportionality within contract law, in balancing the rights and obligations of the contracting parties. It illustrates that the principle of proportionality is one of the general principles which govern contractual relations, and as such it is an

  11. Putative golden proportions as predictors of facial esthetics in adolescents.

    Science.gov (United States)

    Kiekens, Rosemie M A; Kuijpers-Jagtman, Anne Marie; van 't Hof, Martin A; van 't Hof, Bep E; Maltha, Jaap C

    2008-10-01

    In orthodontics, facial esthetics is assumed to be related to golden proportions apparent in the ideal human face. The aim of the study was to analyze the putative relationship between facial esthetics and golden proportions in white adolescents. Seventy-six adult laypeople evaluated sets of photographs of 64 adolescents on a visual analog scale (VAS) from 0 to 100. The facial esthetic value of each subject was calculated as a mean VAS score. Three observers recorded the position of 13 facial landmarks included in 19 putative golden proportions, based on the golden proportions as defined by Ricketts. The proportions and each proportion's deviation from the golden target (1.618) were calculated. This deviation was then related to the VAS scores. Only 4 of the 19 proportions had a significant negative correlation with the VAS scores, indicating that beautiful faces showed less deviation from the golden standard than less beautiful faces. Together, these variables explained only 16% of the variance. Few golden proportions have a significant relationship with facial esthetics in adolescents. The explained variance of these variables is too small to be of clinical importance.

  12. Visualizing Proportions and Dissimilarities by Space-filling Maps

    DEFF Research Database (Denmark)

    Carrizosa, Emilio; Guerrero, Vanesa; Morales, Dolores Romero

    2017-01-01

    In this paper we address the problem of visualizing a set of individuals, which have attached a statistical value given as a proportion, and a dissimilarity measure. Each individual is represented as a region within the unit square, in such a way that the area of the regions represent the proport...

  13. Store-Forward and its implications for Proportional Scheduling

    NARCIS (Netherlands)

    Walton, N.S.

    2014-01-01

    The Proportional Scheduler was recently proposed as a scheduling algorithm for multi-hop switch networks. For these networks, the BackPressure scheduler is the classical benchmark. For networks with fixed routing, the Proportional Scheduler is maximum stable, myopic and, furthermore, will alleviate

  14. 16 CFR 240.9 - Proportionally equal terms.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Proportionally equal terms. 240.9 Section 240.9 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES FOR ADVERTISING ALLOWANCES AND OTHER MERCHANDISING PAYMENTS AND SERVICES § 240.9 Proportionally equal terms. (a...

  15. The Fibonacci Sequence: Proportional Semantic Bases of Children's Aesthetic Preferences.

    Science.gov (United States)

    Neperud, Ronald W.; Serlin, Ronald C.

    1984-01-01

    Only at the third- and seventh-grade levels did proportional preferences for Fibonacci figures differ significantly from preferences for other kinds of proportional spatial divisions. Semantic patterns were similar among third and fifth graders, with a change occurring between fifth and seventh grades in keeping with the development of formal…

  16. Putative golden proportions as predictors of facial esthetics in adolescents.

    NARCIS (Netherlands)

    Kiekens, R.M.A.; Kuijpers-Jagtman, A.M.; Hof, M.A. van 't; Hof, BE van 't; Maltha, J.C.

    2008-01-01

    INTRODUCTION: In orthodontics, facial esthetics is assumed to be related to golden proportions apparent in the ideal human face. The aim of the study was to analyze the putative relationship between facial esthetics and golden proportions in white adolescents. METHODS: Seventy-six adult laypeople

  17. Hardware support for collecting performance counters directly to memory

    Science.gov (United States)

    Gara, Alan; Salapura, Valentina; Wisniewski, Robert W.

    2012-09-25

    Hardware support for collecting performance counters directly to memory, in one aspect, may include a plurality of performance counters operable to collect one or more counts of one or more selected activities. A first storage element may be operable to store an address of a memory location. A second storage element may be operable to store a value indicating whether the hardware should begin copying. A state machine may be operable to detect the value in the second storage element and trigger hardware copying of data in selected one or more of the plurality of performance counters to the memory location whose address is stored in the first storage element.

  18. The Application of Counter-Rotating Turbine in Rocket Turbopump

    Directory of Open Access Journals (Sweden)

    Tang Fei

    2008-01-01

    Full Text Available Counter rotating turbine offers advantages on weight, volume, efficiency, and maneuverability relative to the conventional turbine because of its special architecture. Nowadays, it has been a worldwide research emphasis and has been used widely in the aeronautic field, while its application in the astronautic field is seldom investigated. Researches of counter rotating turbine for rocket turbopump are reviewed in this paper. A primary analysis of a vaneless counter rotating-turbine configuration with rotors of different diameters and rotational speeds is presented. This unconventional configuration meets the requirements of turbopump and may benefit the performance and reliability of rocket engines.

  19. Countering the ‘Natural’ Organizational Self on Social Media

    DEFF Research Database (Denmark)

    Johansen, Trine Susanne

    2017-01-01

    Using narrative as a theoretical and methodological lens, this study explores digital processes of organizational identity construction in the intersection between organization and market.The purpose is to understand the ways in which online interactions produce counter-narratives that contrast......, challenge and contradict organizational self-narration in light of market place skepticism and cynicism. The study identifies three strategies of counter-narrativizing (authenticity, legitimacy and irony) based on juxtaposing pairs of opposites. Moreover, it suggests counter-narration to be a natural...

  20. Development of Laser-Based Handheld Aerosol Particle Counter

    Institute of Scientific and Technical Information of China (English)

    CHEN Chang; LI Hui

    2005-01-01

    The JC-CA300 handheld Aerosol particle counter is designed and developed based on light scattering principle. The JC-CA300 counter is composed of optical sensor, DSP component and microprocessor unit. The hardware architecture is designed in compact style by SMT IC chips. The whole counter weight is less than 2 pounds. With 32K RAM space, the JC-CA300 can store 500 sampling records and support standard printer and communicate with a computer through RS232 interface. Based on experimental results, the main performance of JC-CA300 is better than that of the ARTI'S HHPC-6 instrument.

  1. To evaluate the validity of Recurring Esthetic Dental proportion in natural dentition

    National Research Council Canada - National Science Library

    Shetty, Shilpa; Pitti, Varun; Satish Babu, Cl; Surendra Kumar, Gp; Jnanadev, Kr

    2011-01-01

    Different proportions are described in the literature for smile designing, such as Golden proportion, Golden percentage, Preston's proportion, and recently, Recurring Esthetic Dental (RED) proportion...

  2. Proportional reasoning as a key to numeracy across the curriculum

    DEFF Research Database (Denmark)

    Hilton, Annette; Hilton, Geoff

    2013-01-01

    . Proportional reasoning is the ability to understand, interpret, and solve problems related to situations of proportion, using comparison and relative and multiplicative thinking. It relies on numerous foundational skills including fractional thinking and an understanding of ratio, scale, decimals......Numeracy (mathematical literacy) is an essential skill in life and work. Lack of numeracy has been linked to poor health and work outcomes, and diminished social and civic participation. A key aspect of numeracy, which is not often explicitly mentioned in school curricula, is proportional reasoning...... internationally. Research has also shown that while proportional reasoning develops in students from Years 5 to 9, this development does not always happen naturally. Further, research suggests that targeted teaching can assist students to develop better proportional reasoning skills. This multi-state Australian...

  3. Dynamic adjustment: an electoral method for relaxed double proportionality

    CERN Document Server

    Linusson, Svante

    2013-01-01

    We describe an electoral system for distributing seats in a parliament. It gives proportionality for the political parties and close to proportionality for constituencies. The system suggested here is a version of the system used in Sweden and other Nordic countries with permanent seats in each constituency and adjustment seats to give proportionality on the national level. In the national election of 2010 the current Swedish system failed to give proportionality between parties. We examine here one possible cure for this unwanted behavior. The main difference compared to the current Swedish system is that the number of adjustment seats is not fixed, but rather dynamically determined to be as low as possible and still insure proportionality between parties.

  4. Which Mixed-Member Proportional Electoral Formula Fits You Best? Assessing the Proportionality Principle of Positive Vote Transfer Systems

    DEFF Research Database (Denmark)

    Bochsler, Daniel

    2014-01-01

    Mixed-member proportional systems (MMP) are a family of electoral systems which combine district-based elections with a proportional seat allocation. Positive vote transfer systems belong to this family. This article explains why they might be better than their siblings, and examines under which ...

  5. Current Over-the-Counter Medicine Label: Take a Look

    Science.gov (United States)

    ... This is to help protect consumers against possible criminal tampering. Drug products with tamper-evident packaging have ... Medicines Medicines in My Home (MIMH) Choosing the right over-the-counter medicine (OTCs) The Over-the- ...

  6. Calibration and Monte Carlo modelling of neutron long counters

    CERN Document Server

    Tagziria, H

    2000-01-01

    The Monte Carlo technique has become a very powerful tool in radiation transport as full advantage is taken of enhanced cross-section data, more powerful computers and statistical techniques, together with better characterisation of neutron and photon source spectra. At the National Physical Laboratory, calculations using the Monte Carlo radiation transport code MCNP-4B have been combined with accurate measurements to characterise two long counters routinely used to standardise monoenergetic neutron fields. New and more accurate response function curves have been produced for both long counters. A novel approach using Monte Carlo methods has been developed, validated and used to model the response function of the counters and determine more accurately their effective centres, which have always been difficult to establish experimentally. Calculations and measurements agree well, especially for the De Pangher long counter for which details of the design and constructional material are well known. The sensitivit...

  7. leaves extracts as counter stain in gram staining reaction 56

    African Journals Online (AJOL)

    DR. AMINU

    Keywords: Aqueous Extract, Dyes, Henna, Counter-Staining. INTRODUCTION ... is a stain with color contrasting to the principal stain, making the .... different solutions of ethanol extracts were prepared .... this plant a true natural dye. Saponins ...

  8. Sinus Pain: Can Over-the-Counter Medications Help?

    Science.gov (United States)

    ... requests or policy questions to our media and public relations staff at newsroom@entnet.org . Why Do We ... over-the-counter (OTC) medications. What Is The Role Of OTC Medication For Sinus Pain? There are ...

  9. Over the Counter Laxatives for Constipation: Use with Caution

    Science.gov (United States)

    ... may be best for you. Type of laxative (brand examples) How they work Side effects Oral osmotics ( ... the-counter laxatives. Journal of the American Medical Association. 2014;312:1167. Constipation. National Institute of Diabetes ...

  10. Over-the-counter codeine use in Iceland

    DEFF Research Database (Denmark)

    Almarsdóttir, Anna Birna; Grimsson, A

    2000-01-01

    The objective of this study was to test the assumption that liberalizing community pharmacy ownership in Iceland would lead to increased irrational use of over-the-counter pain relievers containing codeine....

  11. Study Counters Link Between Excess Pregnancy Weight and Overweight Kids

    Science.gov (United States)

    ... Study Counters Link Between Excess Pregnancy Weight and Overweight Kids Connection is likely in the genes, researchers ... 24, 2017 (HealthDay News) -- Kids whose moms were overweight during pregnancy have increased odds of being overweight ...

  12. Investigating Proportional Reasoning in a University Quantitative Literacy Course

    Directory of Open Access Journals (Sweden)

    Vera Frith

    2016-01-01

    Full Text Available The ability to reason with proportions is known to take a long time to develop and to be difficult to learn. We regard proportional reasoning (the ability to reason about quantities in relative terms as a threshold concept for academic quantitative literacy. Our study of the teaching and learning of proportional reasoning in a university quantitative literacy course for law students consisted of iterative action research, in which we introduced various teaching interventions and analysed students’ written responses to assessment questions requiring students to explain their reasoning in situations that call for proportional reasoning. For this analysis we used a modified phenomenographic method to develop and refine a framework to code the responses. This enabled us to broadly describe the responses in terms of the concept of the liminal space that a student must traverse in coming to a full understanding of a threshold concept, and to further define the liminal space to facilitate finer description of students’ responses. Our latest analysis confirmed that many university students cannot reason with proportions, that this kind of thinking is difficult to learn, and that it takes more time than is available in a one-semester course. The context and structure of the questions have a marked effect on students’ ability to apply proportional reasoning successfully. The fraction of students who were classified as ‘at or over the threshold’ (i.e., fairly competent at proportional reasoning after instruction ranged between 8% for the most difficult question and 48% for the easiest.

  13. Bathroom Buddies: Countering your Clockwise Rotation

    Science.gov (United States)

    Cooper, C. M.; Stegman, D. R.

    2006-12-01

    Which way does your bathtub, toilet, sink, or other favorite plumbing basin drain? Popular television shows perpetuate the fact that water spins the opposite direction in the southern hemisphere, and sometimes even explicitly point to the Coriolis effect (or Earth's rotation) as the cause. Skeptics disagree: "No way. Water doesn't obey your rules: it goes where it wants...like me, babe." [1]. Fact: Cyclones rotate clockwise in the southern hemisphere and hurricanes counter-clockwise in the northern hemisphere. But does your hemisphere also determine the direction water spirals down your toilet? In the ideal scenario of water draining out a sink (i.e. a defect-free, perfectly-leveled basin in which water has remained undisturbed for sufficient enough time to quiet any background motions or eddies) --- then yes, maybe it is possible. However, in everyday life, not even the most decadent of bathtubs provide us a large enough lengthscale to observe the Coriolis effect on the direction which water spirals towards the drain. Thus, we are left confronting the possibility that something heard on television isn't true. But is just "telling" students, friends, or strangers in bars enough to debunk this urban myth? Rather, we offer a practical demonstration involving a friend from the opposite hemisphere (if not one in existence, then find one on the internet!), a bathroom, a funnel, a bucket, some food coloring, a camera, a pitcher and some equations and scalings for extra credit and fun. 1) Simpson, B., "Bart vs. Australia", Season 6, Episode 119, 1995.

  14. Evaluation of dual flow counter-current chromatography and intermittent counter-current extraction.

    Science.gov (United States)

    Ignatova, Svetlana; Hewitson, Peter; Mathews, Ben; Sutherland, Ian

    2011-09-09

    The aim of this research is to compare two continuous extraction technologies, intermittent counter-current extraction (ICcE) and dual flow counter-current chromatography (DFCCC), in terms of loading and throughput using the GUESSmix, and show the advantages and disadvantages of the two methods. A model sample containing caffeine, vanillin, naringenin and carvone, with a total load of 11.2 g, was employed with a hexane-ethyl acetate-methanol-water (2:3:2:3) phase system to evaluate an ICcE method on a preparative (912 ml coil volume) DE-Midi instrument. While DFCCC was carried out on a specially designed preparative (561 ml coil volume) bobbin installed in a similar Midi instrument case. While similar throughputs of 7.8 g/h and 6.9 g/h were achieved for the ICcE and DFCCC methods respectively, ICcE was demonstrated to have a number of advantages over DFCCC.

  15. Over-the-counter codeine use in Iceland

    DEFF Research Database (Denmark)

    Almarsdóttir, Anna Birna; Grimsson, A

    2000-01-01

    The objective of this study was to test the assumption that liberalizing community pharmacy ownership in Iceland would lead to increased irrational use of over-the-counter pain relievers containing codeine.......The objective of this study was to test the assumption that liberalizing community pharmacy ownership in Iceland would lead to increased irrational use of over-the-counter pain relievers containing codeine....

  16. Using DMA for copying performance counter data to memory

    Science.gov (United States)

    Gara, Alan; Salapura, Valentina; Wisniewski, Robert W

    2013-12-31

    A device for copying performance counter data includes hardware path that connects a direct memory access (DMA) unit to a plurality of hardware performance counters and a memory device. Software prepares an injection packet for the DMA unit to perform copying, while the software can perform other tasks. In one aspect, the software that prepares the injection packet runs on a processing core other than the core that gathers the hardware performance data.

  17. Over-the-counter treatments for acne and rosacea.

    Science.gov (United States)

    Rosamilia, Lorraine Larsen

    2016-06-01

    Acne and rosacea are common inflammatory processes historically classified in the same disease category, but evolving understanding of their disparate pathophysiology and exacerbating factors have generated an enormous armamentarium of therapeutic possibilities. Patients seek over-the-counter therapies first when managing cutaneous disease; therefore, this review defines ingredients considered to be effective over-the-counter acne and rosacea products, their mechanisms, and safe formulations, including botanical components, oral supplements, and other anecdotal options in this vast skin care domain.

  18. CounterPoint: Zeeman-split absorption lines

    Science.gov (United States)

    Deen, Casey

    2015-12-01

    CounterPoint works in concert with MoogStokes (ascl:1308.018). It applies the Zeeman effect to the atomic lines in the region of study, splitting them into the correct number of Zeeman components and adjusting their relative intensities according to the predictions of Quantum Mechanics, and finally creates a Moog-readable line list for use with MoogStokes. CounterPoint has the ability to use VALD and HITRAN line databases for both atomic and molecular lines.

  19. Liberty and Order: Reintegration as Counter-Insurgency in Colombia

    Science.gov (United States)

    2003-01-01

    experienced the same fits and starts as others in the region. There have been successes , including the reintegration of the M-19 (Movimiento del 19... REINTEGRATION AS COUNTER-INSURGENCY IN COLOMBIA Mr. GREGORY E. PHILLIPS, DOS COURSE 5601 and 5602 FUNDAMENTALS OF STRATEGIC LOGIC and THE NATURE OF...COVERED 00-00-2003 to 00-00-2003 4. TITLE AND SUBTITLE Liberty and Order: Reintegration as Counter-Insurgency in Colombia 5a. CONTRACT NUMBER 5b

  20. Counter-terrorism judicial review by a traditionally weak judiciary

    DEFF Research Database (Denmark)

    Rytter, Jens Elo

    2014-01-01

    The article analyses recent Danish case law on counter-terrorism measures to ascertain the extent to which a tradiitonally weak judiciary like the Danish one performs a real review. The conclusion is that the review is real, but measured.......The article analyses recent Danish case law on counter-terrorism measures to ascertain the extent to which a tradiitonally weak judiciary like the Danish one performs a real review. The conclusion is that the review is real, but measured....

  1. MODELS FOR THE COUNTER-GRADIENT TRANSPORT PHENOMENA

    Institute of Scientific and Technical Information of China (English)

    蒋剑波; 卢志明; 刘晓明; 刘宇陆

    2001-01-01

    The counter gradient transport phenomena on momentum, energy and passive scalar in turbulent flows were studied by use of the single response function for TSDIA. As a result, models that can describe qualitatively the phenomena are obtained. Then the results are simplified by use of the inertial range theory, and the results for lower degrees agree with results of predecessor. Finally the counter gradient-transport phenomena in channel flow and circular wake flow are analyzed.

  2. Transformation of equations in analysis of proportionality through referent models

    CERN Document Server

    Romay, E O

    2006-01-01

    In proportionality of objects, samples or populations, usually we work with Z score of proportionality calculated through referent models, instead directly with the variables of the objects in itself. In these studies we have the necessity to transform, the equations that use the variables of the object, in equations that directly use like variables Z score. In the present work a method is developed to transform the parametric equations, in equations in variables Z using like example the studies of human proportionality from the Phantom stratagem of Ross and Wilson.

  3. Development and testing of a deuterium gas target assembly for neutron production via the H-2(d,n)He-3 reaction at a low-energy accelerator facility

    Energy Technology Data Exchange (ETDEWEB)

    Feautrier, D.; Smith, D.L.

    1992-03-01

    This report describes the development and testing of a deuterium gas target intended for use at a low-energy accelerator facility to produce neutrons for basic research and various nuclear applications. The principle source reaction is H-2(d,n)He-3. It produces a nearly mono-energetic group of neutrons. However, a lower-energy continuum neutron spectrum is produced by the H-2(d;n,p)H-2 reaction and also by deuterons which strike various components in the target assembly. The present target is designed to achieve the following objectives: (1) minimize unwanted background neutron production from the target assembly, (2) provide a relatively low level of residual long-term activity within the target components, (3) have the capacity to dissipate up to 150 watts of beam power with good target longevity, and (4) possess a relatively modest target mass in order to minimize neutron scattering from the target components. The basic physical principles that have to be considered in designing an accelerator target are discussed and the major engineering features of this particular target design are outlined. The results of initial performance tests on this target are documented and some conclusions concerning the viability of the target design are presented.

  4. Advertising health: the case for counter-ads.

    Science.gov (United States)

    Dorfman, L; Wallack, L

    1993-01-01

    Public service advertisements have been used by many in hopes of "selling" good health behaviors. But selling good behavior--even if it could be done more effectively--is not the best goal for using mass media to prevent health problems. Personal behavior is only part of what determines health status. Social conditions and the physical environment are important determinants of health that are usually ignored by health promotion advertising. Public service advertising may be doing more harm than good if it is diverting attention from more effective socially based health promotion strategies. Counter-ads are one communications strategy that could be used to promote a broader responsibility for rectifying health problems. In the tradition of advocacy advertising directly promoting policy rather than products, counter-ads promote views consistent with a public health perspective. Counter-ads set the agenda for health issues, conferring status on policy-oriented strategies for addressing health problems. The primary purpose of counter-ads is to challenge the dominant view that public health problems reflect personal health habits. They are controversial because they place health issues in a social and political context. Advertising strategies for health promotion range over a spectrum from individually oriented public service advertising to socially oriented counter-advertising. The recent anti-tobacco campaign from the California Department of Health Services represents advertisements across the spectrum. Counter-ads that focus on a politically controversial definition for health problems are an appropriate and necessary alternative to public service advertising.

  5. Message passing with a limited number of DMA byte counters

    Energy Technology Data Exchange (ETDEWEB)

    Blocksome, Michael (Rochester, MN); Chen, Dong (Croton on Hudson, NY); Giampapa, Mark E. (Irvington, NY); Heidelberger, Philip (Cortlandt Manor, NY); Kumar, Sameer (White Plains, NY); Parker, Jeffrey J. (Rochester, MN)

    2011-10-04

    A method for passing messages in a parallel computer system constructed as a plurality of compute nodes interconnected as a network where each compute node includes a DMA engine but includes only a limited number of byte counters for tracking a number of bytes that are sent or received by the DMA engine, where the byte counters may be used in shared counter or exclusive counter modes of operation. The method includes using rendezvous protocol, a source compute node deterministically sending a request to send (RTS) message with a single RTS descriptor using an exclusive injection counter to track both the RTS message and message data to be sent in association with the RTS message, to a destination compute node such that the RTS descriptor indicates to the destination compute node that the message data will be adaptively routed to the destination node. Using one DMA FIFO at the source compute node, the RTS descriptors are maintained for rendezvous messages destined for the destination compute node to ensure proper message data ordering thereat. Using a reception counter at a DMA engine, the destination compute node tracks reception of the RTS and associated message data and sends a clear to send (CTS) message to the source node in a rendezvous protocol form of a remote get to accept the RTS message and message data and processing the remote get (CTS) by the source compute node DMA engine to provide the message data to be sent.

  6. Over the counter ophthalmic drug misuse, are we aware?

    Directory of Open Access Journals (Sweden)

    Rajani Kadri

    2010-07-01

    Full Text Available Aim: To investigate the misuse of ‘over the counter’ ophthalmic medications in our city. Method: Responses of a structured questionnaire covering various aspects of over the counter drug use was obtained from pharmacy workers in and around our city. Results: Eighty nine pharmacy workers took part in this cross–sectional study. An average number of seven patients per day with ophthalmic complaints were seen by the pharmacy workers. Dispensing over the counter was practiced by 89.9% of the pharmacists. The most common complaint of the patients visiting the pharmacy, was redness and itching (86.5%. Antibiotics (96.6% were the most common eye drops dispensed over the counter, followed by steroids (55.1%, decongestants (54.1%, antibiotic-steroid combination eye drops (29.2% and lubricants (16.8%. Awareness regarding complications of steroid use was seen in 40.6% of pharmacists. 6.7% pharmacists had seen patients with complications following use of over the counter medications. In our study, majority of the eye drops dispensed were prescription drugs. Conclusion: Availability of prescription eye drops over the counter is an immense public threat. Educating the pharmacist and the population can decrease ocular morbidity. Research into methods to effectively deal with over-the-counter drug misuse is required and law can be enforced based on the findings.

  7. Proportion and factors associated with low fifth minute Apgar score ...

    African Journals Online (AJOL)

    Proportion and factors associated with low fifth minute Apgar score among ... with low Apgar scores are at an increased risk of perinatal morbidity and mortality. ... of meconium stained liquor, induced/ augmented labor and low birth weight.

  8. Proportionality: a valid alternative to correlation for relative data.

    Directory of Open Access Journals (Sweden)

    David Lovell

    2015-03-01

    Full Text Available In the life sciences, many measurement methods yield only the relative abundances of different components in a sample. With such relative-or compositional-data, differential expression needs careful interpretation, and correlation-a statistical workhorse for analyzing pairwise relationships-is an inappropriate measure of association. Using yeast gene expression data we show how correlation can be misleading and present proportionality as a valid alternative for relative data. We show how the strength of proportionality between two variables can be meaningfully and interpretably described by a new statistic ϕ which can be used instead of correlation as the basis of familiar analyses and visualisation methods, including co-expression networks and clustered heatmaps. While the main aim of this study is to present proportionality as a means to analyse relative data, it also raises intriguing questions about the molecular mechanisms underlying the proportional regulation of a range of yeast genes.

  9. The proportional fairness scheduling algorithm on multi-classes

    Institute of Scientific and Technical Information of China (English)

    江勇; 吴建平

    2003-01-01

    In this paper, we study resource management models and algorithms that satisfy multiple performance objects simultaneously. We realize the proportional fairness principle based QoS model, which defines both delay and loss rate requirements of a class, to include fairness, which is important for the integration of multiple service classes. The resulting Proportional Fairness Scheduling model formalizes the goals of the network performance, user's QoS requirement and system fairness and exposes the fundamental tradeoffs between these goals. In particular, it is difficult to simultaneously provide these objects. We propose a novel scheduling algorithm called Proportional Fairness Scheduling (PFS) that approximates the model closely and efficiently. We have implemented the PFS scheduling in Linux. By performing simulation and measurement experiments, we evaluate the delay and loss rate proportional fairness of PFS, and determine the computation overhead.

  10. Estimating the Proportion of True Null Hypotheses for Multiple Comparisons

    National Research Council Canada - National Science Library

    Hongmei Jiang; RW Doerge

    2008-01-01

    ...) controlling procedures are too conservative. Although false discovery rate (FDR) procedures have been suggested as having greater power, the control itself is not exact and depends on the proportion of true null hypotheses...

  11. DC motor proportional control system for orthotic devices

    Science.gov (United States)

    Blaise, H. T.; Allen, J. R.

    1972-01-01

    Multi-channel proportional control system for operation of dc motors for use with externally-powered orthotic arm braces is described. Components of circuitry and principles of operation are described. Schematic diagram of control circuit is provided.

  12. Empirical study of alginate impression materials by customized proportioning system

    Science.gov (United States)

    2016-01-01

    PURPOSE Alginate mixers available in the market do not have the automatic proportioning unit. In this study, an automatic proportioning unit for the alginate mixer and controller software were designed and produced for a new automatic proportioning unit. With this device, it was ensured that proportioning operation could arrange weight-based alginate impression materials. MATERIALS AND METHODS The variation of coefficient in the tested groups was compared with the manual proportioning. Compression tension and tear tests were conducted to determine the mechanical properties of alginate impression materials. The experimental data were statistically analyzed using one way ANOVA and Tukey test at the 0.05 level of significance. RESULTS No statistically significant differences in modulus of elastisity (P>0.3), tensional/compresional strength (P>0.3), resilience (P>0.2), strain in failure (P>0.4), and tear energy (P>0.7) of alginate impression materials were seen. However, a decrease in the standard deviation of tested groups was observed when the customized machine was used. To verify the efficiency of the system, powder and powder/water mixing were weighed and significant decrease was observed. CONCLUSION It was possible to obtain more mechanically stable alginate impression materials by using the custom-made proportioning unit. PMID:27826387

  13. Empirical study of alginate impression materials by customized proportioning system.

    Science.gov (United States)

    Kurtulus, Karani; Tüfekci, Kenan

    2016-10-01

    Alginate mixers available in the market do not have the automatic proportioning unit. In this study, an automatic proportioning unit for the alginate mixer and controller software were designed and produced for a new automatic proportioning unit. With this device, it was ensured that proportioning operation could arrange weight-based alginate impression materials. The variation of coefficient in the tested groups was compared with the manual proportioning. Compression tension and tear tests were conducted to determine the mechanical properties of alginate impression materials. The experimental data were statistically analyzed using one way ANOVA and Tukey test at the 0.05 level of significance. No statistically significant differences in modulus of elastisity (P>0.3), tensional/compresional strength (P>0.3), resilience (P>0.2), strain in failure (P>0.4), and tear energy (P>0.7) of alginate impression materials were seen. However, a decrease in the standard deviation of tested groups was observed when the customized machine was used. To verify the efficiency of the system, powder and powder/water mixing were weighed and significant decrease was observed. It was possible to obtain more mechanically stable alginate impression materials by using the custom-made proportioning unit.

  14. ["Golden proportion" and its application to calculate dentition].

    Science.gov (United States)

    Vadachkoriia, N R; Gumberidze, N Sh; Mandzhavidze, N A

    2007-01-01

    Within an evolutionary process, the nature has created the standard of aesthetics - a "gold proportion" on the basis of which, the parts of human body, to be more exact, teeth and denture correspond to each other and to own parts by the size, which is the ideal precondition for ideal appearance. The charming smile serves as the proof, that teeth in denture are located by a principle of "gold proportion". A "gold proportion" is the corner stone of beauty and it can be applied with success in stomatology. Proportion is the certain ratio between parts, and proportional means a proper correlation of parts among themselves. It is reputed, that knowledge about "gold proportion" Pythagor has got from products of the Egyptian and Babylon scientists. And this is true, proportions of cult constructions, bas-relieves, pyramids in Giza, home appliances and ornaments from Tutanhamon tomb testify, that under their creation the Egyptian masters were guided by a principle of "gold proportion". The facade of ancient Greek temple Parthenon is built by a principle of "gold proportion". During archeological digs of this temple the compasses which sculptors and architects of an ancient world used has been found. The "gold proportion" is mentioned in the work which has reached us "Beginning" the author is the scientist of antique epoch Euclid. In 1509, in Venice the book of Luka Pacholi the "Divine proportion" has been published, its illustration is attributed to Leonardo de Vinci. This work has been recognized as a "Hymn of a gold proportion". In 1885 the German researcher professor Zeising published his work - "Aesthetic researches". When Zeising has received numerical values of piece length, he saw that they coincided with figures of some numerical sequence, which was offered by the great Italian mathematician of Middle Ages Fibonacci (or Leonardo Pisano). In his composition the "Abacus Book" Leonardo Fibonacci showed aforesaid sequence of numbers, by means of which he has explained

  15. Assessment of facial golden proportions among central Indian population

    Science.gov (United States)

    Saurabh, Rathore; Piyush, Bolya; Sourabh, Bhatt; Preeti, Ojha; Trivedi, Rutvik; Vishnoi, Pradeep

    2016-01-01

    Aim: This study aimed to identify and establish the facial and smile proportions in young adults and to compare the results with ideal or divine proportions, compare the proportions of males and females included in our study population and compare them with those established for Caucasian and Japanese populations. Materials and Methods: Two hundred participants (164 females, 36 males) with Angle's class I malocclusion (M.O). and well-balanced faces were selected and photographed in the frontal repose position. Analysis was done in Adobe Photoshop software. Statistical analysis was done using the Statistical Package for the Social Sciences version 17.0. (IBM Corporation Armonk, New York, United States). Results: Results suggested that females are more near to ideal ratios and males are more deviated from the ideal ratios. The proportions of males and females were not considerably different from each other. In Indian population, upper 3rd facial height (TR-LC) was increased and mid-face height (LC-LN) was decreased; in lower 3rd of the face, LN-CH was slightly increased in comparison to CH-ME. In facial widths, outer canthal width (LC-LC) was greater in the Indian population and mouth width (CH-CH) was normal. When compared with Indian population, Japanese participants had wider noses, outer canthal distance, and bitemporal width. Conclusion: It was concluded that significant difference was found between the proportions of the Indian population and ideal ratio. When Indian population was compared with Japanese and Caucasian populations, some parameters of facial proportions showed significant difference, which leads to the need for establishing standardized norms for various facial proportions in Indian population. PMID:28217534

  16. Photons co- and counter-propagating through $N$ cross-Kerr sites

    CERN Document Server

    Brod, Daniel J

    2016-01-01

    A cross-Kerr interaction produces a phase shift on two modes of light proportional to the number of photons in both modes, and is sometimes called cross-phase modulation. Cross-Kerr nonlinearities have many applications in classical and quantum nonlinear optics, including the possibility of a deterministic and all-optical controlled-phase gate. We calculate the one- and two-photon S-matrix for fields propagating in a medium where the cross-Kerr interaction is spatially distributed at discrete interaction sites comprised of atoms. For the interactions considered, we analyze the cases where the photons co-propagate and counter-propagate through the medium and give a physical interpretation to the differences between the two cases.

  17. Limb proportions show developmental plasticity in response to embryo movement

    Science.gov (United States)

    Pollard, A. S.; Charlton, B. G.; Hutchinson, J. R.; Gustafsson, T.; McGonnell, I. M.; Timmons, J. A.; Pitsillides, A. A.

    2017-01-01

    Animals have evolved limb proportions adapted to different environments, but it is not yet clear to what extent these proportions are directly influenced by the environment during prenatal development. The developing skeleton experiences mechanical loading resulting from embryo movement. We tested the hypothesis that environmentally-induced changes in prenatal movement influence embryonic limb growth to alter proportions. We show that incubation temperature influences motility and limb bone growth in West African Dwarf crocodiles, producing altered limb proportions which may, influence post-hatching performance. Pharmacological immobilisation of embryonic chickens revealed that altered motility, independent of temperature, may underpin this growth regulation. Use of the chick also allowed us to merge histological, immunochemical and cell proliferation labelling studies to evaluate changes in growth plate organisation, and unbiased array profiling to identify specific cellular and transcriptional targets of embryo movement. This disclosed that movement alters limb proportions and regulates chondrocyte proliferation in only specific growth plates. This selective targeting is related to intrinsic mTOR (mechanistic target of rapamycin) pathway activity in individual growth plates. Our findings provide new insights into how environmental factors can be integrated to influence cellular activity in growing bones and ultimately gross limb morphology, to generate phenotypic variation during prenatal development. PMID:28165010

  18. Detailed Network Measurements Using Sparse Graph Counters: The Theory

    CERN Document Server

    Lu, Yi; Prabhakar, Balaji

    2007-01-01

    Measuring network flow sizes is important for tasks like accounting/billing, network forensics and security. Per-flow accounting is considered hard because it requires that many counters be updated at a very high speed; however, the large fast memories needed for storing the counters are prohibitively expensive. Therefore, current approaches aim to obtain approximate flow counts; that is, to detect large elephant flows and then measure their sizes. Recently the authors and their collaborators have developed [1] a novel method for per-flow traffic measurement that is fast, highly memory efficient and accurate. At the core of this method is a novel counter architecture called "counter braids.'' In this paper, we analyze the performance of the counter braid architecture under a Maximum Likelihood (ML) flow size estimation algorithm and show that it is optimal; that is, the number of bits needed to store the size of a flow matches the entropy lower bound. While the ML algorithm is optimal, it is too complex to im...

  19. A reduced feedback proportional fair multiuser scheduling scheme

    KAUST Repository

    Shaqfeh, Mohammad

    2011-12-01

    Multiuser switched-diversity scheduling schemes were recently proposed in order to overcome the heavy feedback requirements of conventional opportunistic scheduling schemes by applying a threshold-based, distributed and ordered scheduling mechanism. A slight reduction in the prospected multiuser diversity gains is an acceptable trade-off for great savings in terms of required channel-state-information feedback messages. In this work, we propose a novel proportional fair multiuser switched-diversity scheduling scheme and we demonstrate that it can be optimized using a practical and distributed method to obtain the per-user feedback thresholds. We demonstrate by numerical examples that our reduced feedback proportional fair scheduler operates within 0.3 bits/sec/Hz from the achievable rates by the conventional full feedback proportional fair scheduler in Rayleigh fading conditions. © 2011 IEEE.

  20. Biofuel proportions in fuels by AMS radiocarbon method

    Energy Technology Data Exchange (ETDEWEB)

    Oinonen, M., E-mail: markku.j.oinonen@helsinki.f [Dating Laboratory, Finnish Museum of Natural History, University of Helsinki, P.O. Box 64, FIN-00014 (Finland); Hakanpaeae-Laitinen, H. [Neste Oil Oyj, Research and Technology, Porvoo (Finland); Haemaelaeinen, K.; Kaskela, A.; Jungner, H. [Dating Laboratory, Finnish Museum of Natural History, University of Helsinki, P.O. Box 64, FIN-00014 (Finland)

    2010-04-15

    Within the context of expanding use of biofuels in transport worldwide, a need has emerged to accurately determine biofuel proportions of fuels. In this study, the radiocarbon method by AMS has been used to study the fuel mixtures containing 2%, 5% and 30% of the NExBTL renewable diesel, particularly. Special effort has been put to develop reproducible pretreatment and combustion methods and to verify the reliable determination of the low biofuel proportions - corresponding to the present status of the European-wide biofuel usage. The developed procedures are ready to meet the requirements set in the ASTM D 6866-06a standard and demonstrate our ability to perform reliable measurements on biofuel proportions in fuels.

  1. Prospective Teachers Proportional Reasoning and Presumption of Student Work

    Directory of Open Access Journals (Sweden)

    Mujiyem Sapti

    2015-08-01

    Full Text Available This study aimed to describe the proportional reasoning of prospective teachers and their predictions about students' answers. Subjects were 4 prospective teacher  7th semester Department of Mathematics Education, Muhammadiyah University of Purworejo. Proportional reasoning task used to obtain research data. Subjects were asked to explain their reasoning and write predictions of student completion. Data was taken on October 15th, 2014. Interviews were conducted after the subjects completed the task and recorded with audio media. The research data were subject written work and interview transcripts. Data were analyzed using qualitative analysis techniques. In solving the proportional reasoning task, subjects using the cross product. However, they understand the meaning of the cross product. Subject also could predict students' reasoning on the matter.

  2. In vivo measurement of actinides in the human lung. [Calibration and comparison of Phoswich, large-area proportional counter, and intrinsic germanium planar array detector systems

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, A.L.; Campbell, G.W.; Griffith, R.V.

    1979-11-06

    The problems associated with the in vivo detection and measurement of actinides in the human lung are discussed together with various measurement systems currently in use. In particular, the methods and calibration procedures employed at the Lawrence Livermore Laboratory, namely, the use of twin Phoswich detectors and a new, more realistic, tissue-equivalent phantom, are described. Methods for the measurement of chest-wall thickness, fat content, and normal human background counts are also discussed. Detection-efficiency values and minimum detectable activity estimates are given for three common actinides, /sup 238/Pu, /sup 239/Pu, and /sup 241/Am.

  3. Proportional Motor Recovery After Stroke: Implications for Trial Design.

    Science.gov (United States)

    Stinear, Cathy M; Byblow, Winston D; Ackerley, Suzanne J; Smith, Marie-Claire; Borges, Victor M; Barber, P Alan

    2017-03-01

    Recovery of upper-limb motor impairment after first-ever ischemic stroke is proportional to the degree of initial impairment in patients with a functional corticospinal tract (CST). This study aimed to investigate whether proportional recovery occurs in a more clinically relevant sample including patients with intracerebral hemorrhage and previous stroke. Patients with upper-limb weakness were assessed 3 days and 3 months poststroke with the Fugl-Meyer scale. Transcranial magnetic stimulation was used to test CST function, and patients were dichotomized according to the presence of motor evoked potentials in the paretic wrist extensors. Linear regression modeling of Δ Fugl-Meyer score between 3 days and 3 months was performed, with predictors including initial impairment (66 - baseline Fugl-Meyer score), age, sex, stroke type, previous stroke, comorbidities, and upper-limb therapy dose. One hundred ninety-two patients were recruited, and 157 completed 3-month follow-up. Patients with a functional CST made a proportional recovery of 63% (95% confidence interval, 55%-70%) of initial motor impairment. The recovery of patients without a functional CST was not proportional to initial impairment and was reduced by greater CST damage. Recovery of motor impairment in patients with intact CST is proportional to initial impairment and unaffected by previous stroke, type of stroke, or upper-limb therapy dose. Novel interventions that interact with the neurobiological mechanisms of recovery are needed. The generalizability of proportional recovery is such that patients with intracerebral hemorrhage and previous stroke may usefully be included in interventional rehabilitation trials. URL: http://www.anzctr.org.au. Unique identifier: ANZCTR12611000755932. © 2017 American Heart Association, Inc.

  4. Leg length, proportion, health and beauty: a review.

    Science.gov (United States)

    Bogin, Barry; Varela-Silva, Maria Inês

    2009-12-01

    Decomposing stature into its major components is proving to be a useful strategy to assess the antecedents of disease, morbidity and death in adulthood. Human leg length (foot + tibia + femur), sitting height (trunk length + head length) and their proportions (for example the relative leg length in proportion to stature, and the sitting height ratio [sitting height/stature x 100], among others) are used as epidemiological markers of risk for overweight (fatness), coronary heart disease, diabetes and certain cancers. There is also wide support for the use of relative leg length as an indicator of the quality of the environment for growth during infancy, childhood and the juvenile years of development. Human beings follow a cephalo-caudal gradient of growth, the pattern of growth common to all mammals. A special feature of the human pattern is that between birth and puberty the legs grow relatively faster than other post-cranial body segments. For groups of children and youth, short stature due to relatively short legs (i.e. a high sitting height ratio) is generally a marker of an adverse environment. The development of human body proportions is the product of environmental x genomic interactions, although few if any specific genes are known. The short stature homeobox-containing gene (SHOX) is the first genomic region that may be relevant to human body proportions. For example, one of the SHOX related disorders is Turner syndrome. However, in most cases research has been showing that environment is a more powerful force to shape leg length and body proportions than genes. Leg length and proportion are important in the perception of human beauty, which is often considered a sign of health and fertility. There are a variety of cosmetic, fashion, and surgical interventions to enhance perceived or actual leg length.

  5. Student reasoning about ratio and proportion in introductory physics

    Science.gov (United States)

    Boudreaux, Andrew

    2012-02-01

    To many students, introductory physics must seem a fast-moving parade of abstract and somewhat mysterious quantities. Most such quantities are rooted in proportional reasoning. Using ratio, physicists construct the force experienced by a unit charge, and attach the name electric field, or characterize a motion with the velocity change that occurs in a unit time. While physicists reason about these ratios without conscious effort, students tend to resort to memorized algorithms, and at times struggle to match the appropriate algorithm to the situation encountered. Although the term ``proportional reasoning'' is prevalent, skill in reasoning with these ratio quantities is neither acquired nor applied as a single cognitive entity. Expert ability seems to be characterized by the intentional use of a variety of components, or elements of proportional reasoning, by a fluency in shifting from one component to another, and by a skill in selecting from among these components. Based on this perspective, it is natural to expect students to develop proportional reasoning ability in fits and starts as various facets are acquired and integrated into existing understandings. In an ongoing collaboration between Western Washington University, New Mexico State University, and Rutgers, we are attempting to map the rich cognitive terrain of proportional reasoning, and to use our findings to guide the design of instruction that develops fluency. This talk will present a provisional set of proportional reasoning components, along with research tasks that have been developed to measure student ability along these components. Student responses will be presented as evidence of specific modes of thinking. The talk will conclude with a brief outline of our approach to improving student understanding.

  6. Absolute measurement of {beta} emitters with a 4 {pi} counter; Mesure absolue des emetteurs {beta} au compteur 4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Le Gallic, Y. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-06-15

    The object of this work is to investigate the conditions under which the activity of {beta}-emitting radionuclides may be measured with a maximum of precision, and as a result to study the relevant corrections. The various problems relating to activity measurements with a 4 {pi} counter have been examined successively: - comparison of 4 {pi}, GM and proportional counters; - study of the preparation of sources; - corrections on the counting of sources; - self-absorption; - correction for absorption. The precision obtained on these measurements varies from 1.2 to 3 per cent, with the result that the 4 {pi} counter can be considered a very satisfactory calibration instrument. (author) [French] Le but de ce travail est de rechercher les conditions permettant d'obtenir avec le maximum de precision, la mesure de l'activite des radionuclides se desintegrant par emission et par consequent d'etudier les corrections qui s'y rapportent. Nous avons examine successivement les differents problemes se rapportant aux mesures d'activite au compteur 4 {pi}: - Comparaison des compteurs 4 {pi}, GM et proportionnel; - etude de la preparation des sources; - corrections sur la numeration des sources; - auto-absorption; - correction d'absorption. La precision obtenue dans ces mesures, variant de 1,2 a 3 pour cent, on peut donc considerer le compteur 4 {pi} comme un instrument d'etalonnage tres satisfaisant. (auteur)

  7. DMA shared byte counters in a parallel computer

    Science.gov (United States)

    Chen, Dong; Gara, Alan G.; Heidelberger, Philip; Vranas, Pavlos

    2010-04-06

    A parallel computer system is constructed as a network of interconnected compute nodes. Each of the compute nodes includes at least one processor, a memory and a DMA engine. The DMA engine includes a processor interface for interfacing with the at least one processor, DMA logic, a memory interface for interfacing with the memory, a DMA network interface for interfacing with the network, injection and reception byte counters, injection and reception FIFO metadata, and status registers and control registers. The injection FIFOs maintain memory locations of the injection FIFO metadata memory locations including its current head and tail, and the reception FIFOs maintain the reception FIFO metadata memory locations including its current head and tail. The injection byte counters and reception byte counters may be shared between messages.

  8. Wind tunnel tests of stratospheric airship counter rotating propellers

    Directory of Open Access Journals (Sweden)

    Yaxi Chen

    2015-01-01

    Full Text Available Aerodynamic performance of the high-altitude propeller, especially the counter rotation effects, is experimentally studied. Influences of different configurations on a stratospheric airship, included 2-blade counter-rotating propeller (CRP, dual 2-blade single rotation propellers (SRPs and 4-blade SRP, are also indicated. This research indicates that the effect of counter rotation can greatly improve the efficiency. It shows that the CRP configuration results in a higher efficiency than the dual 2-blade SRPs configuration or 4-blade SRP configuration under the same advance ratio, and the CRP configuration also gains the highest efficiency whether under the situation of providing the same trust or absorbing the same power. It concludes that, for a stratospheric airship, the CRP configuration is better than the multiple SRPs configuration or a multi-blade SRP one.

  9. Emergent information technologies and enabling policies for counter-terrorism

    CERN Document Server

    Popp, R

    2006-01-01

    Explores both counter-terrorism and enabling policy dimensions of emerging information technologies in national security After the September 11th attacks, "connecting the dots" has become the watchword for using information and intelligence to protect the United States from future terrorist attacks. Advanced and emerging information technologies offer key assets in confronting a secretive, asymmetric, and networked enemy. Yet, in a free and open society, policies must ensure that these powerful technologies are used responsibly, and that privacy and civil liberties remain protected. Emergent Information Technologies and Enabling Policies for Counter-Terrorism provides a unique, integrated treatment of cutting-edge counter-terrorism technologies and their corresponding policy options. Featuring contributions from nationally recognized authorities and experts, this book brings together a diverse knowledge base for those charged with protecting our nation from terrorist attacks while preserving our civil liberti...

  10. Fast scintillation counters for the D0 muon system upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Baldin, B. [Fermi National Accelerator Lab., Batavia, IL (United States); Abramov, V.; Babintsev, V. [and others

    1999-08-01

    The design and main parameters of the completely redesigned D0 Forward Angle Muon System (FAMUS: 1.0 < {vert_bar}{eta}{vert_bar} < 2.0) for the next high luminosity Tevatron Collider run are reported. Results of the studies of trigger scintillation counters based on fast scintillator Bicron 404A and WLS bars SOFZ-105 are presented. The authors report about results of test beam studies of prototype counters including minimum ionizing particles detection efficiency, time resolution and amplitude response. Radiation ageing of scintillating materials for the doses up to 1 Mrad, phototubes magnetic shielding in the fields of up to 700 G and ageing of phototubes are presented. All tests show robustness of scintillation counters as triggering detector of the new muon system for a long period.

  11. Forensic Speaker Recognition Law Enforcement and Counter-Terrorism

    CERN Document Server

    Patil, Hemant

    2012-01-01

    Forensic Speaker Recognition: Law Enforcement and Counter-Terrorism is an anthology of the research findings of 35 speaker recognition experts from around the world. The volume provides a multidimensional view of the complex science involved in determining whether a suspect’s voice truly matches forensic speech samples, collected by law enforcement and counter-terrorism agencies, that are associated with the commission of a terrorist act or other crimes. While addressing such topics as the challenges of forensic case work, handling speech signal degradation, analyzing features of speaker recognition to optimize voice verification system performance, and designing voice applications that meet the practical needs of law enforcement and counter-terrorism agencies, this material all sounds a common theme: how the rigors of forensic utility are demanding new levels of excellence in all aspects of speaker recognition. The contributors are among the most eminent scientists in speech engineering and signal process...

  12. Radiosonde aerosol counter for vertical profiling of atmospheric dust layers

    Science.gov (United States)

    Ulanowski, Z.; Hirst, E.; Kaye, P. H.; Harrison, R. G.; Nicoll, K. A.; Rogers, G.

    2010-05-01

    A low-cost, miniature aerosol particle counter has been developed, intended for use with balloon-borne meteorological radiosondes. It is particularly suitable for airborne mineral dust measurements. Ambient air is drawn into the counter using a diaphragm pump at a rate of 0.5 litre per minute. The counter detects particles in the airstream using a diode laser and a photodiode. Output from the photodiode is digitised into 5 size bins, with minimum particle diameters equivalent to 0.6, 1.4, 2.6, 5.4 and 10.6 micrometers. The counter is interfaced to a Vaisala RS92 radiosonde, which transmits data from the counter together with meteorological parameters and GPS-derived position to a ground based receiver at 1 Hz rate. Statistically significant particle size distributions can be obtained once a second for number concentrations down to about 100,000 particle per litre (within the measured size range), or correspondingly less at lower temporal resolutions. At the same time, the counter is capable of measuring dust number concentrations exceeding a million per litre without incurring significant errors. Soundings during the DREAME campaign in Kuwait (Ulanowski et al. EGU 2010, AS4.7) and on Cape Verde Islands (Nicoll et al. EGU 2010, AS4.7) provided dust concentration profiles with a typical vertical resolution of 4 m. Comparisons with integrated dust column size distribution measurements from AERONET sun photometers showed good agreement in two out of three cases where near-simultaneous retrievals were available. Optical thickness calculations based on the size distributions measured in Kuwait, with the assumption that the dust particles were prolate spheroids, agreed with the AERONET optical thickness at 675 nm to within 15%.

  13. Proportional Reasoning in the Learning of Chemistry: Levels of Complexity

    Science.gov (United States)

    Ramful, Ajay; Narod, Fawzia Bibi

    2014-01-01

    This interdisciplinary study sketches the ways in which proportional reasoning is involved in the solution of chemistry problems, more specifically, problems involving quantities in chemical reactions (commonly referred to as stoichiometry problems). By building on the expertise of both mathematics and chemistry education research, the present…

  14. Modelling long term survival with non-proportional hazards

    NARCIS (Netherlands)

    Perperoglou, Aristidis

    2006-01-01

    In this work I consider models for survival data when the assumption of proportionality does not hold. The thesis consists of an Introduction, five papers, a Discussion and an Appendix. The Introduction presents technical information about the Cox model and introduces the ideas behind the extensions

  15. System proportions fluid-flow in response to demand signals

    Science.gov (United States)

    1966-01-01

    Control system provides proportioned fluid flow rates in response to demand signals. It compares a digital signal, representing a flow demand, with a reference signal to yield a control voltage to one or more solenoid valves connected to orifices of a predetermined size.

  16. Macroevolutionary diversity of amniote limb proportions predicted by developmental interactions.

    Science.gov (United States)

    Young, Nathan M

    2013-11-01

    Mammals, birds, and reptiles exhibit a remarkable diversity of limb proportions. These evolved differences are thought to reflect selection for biomechanical, postural, and locomotor requirements primarily acting on independent variation in later fetal and postnatal segmental growth. However, earlier conserved developmental events also have the potential to impact the evolvability of limb proportions by limiting or biasing initial variation among segments. Notably, proximo-distal patterning of the amniote limb through activation-inhibition dynamics predicts that initial proportions of segments should exhibit both tradeoffs between stylopod and autopod and a diagnostic reduction in variance of the zeugopod. Here it is demonstrated that this developmental "design rule" predicts patterns of macroevolutionary diversity despite the effects of variation in segmental growth over ontogeny, lineage-specific differences in phylogenetic history, or functional adaptation. These results provide critical comparative evidence of a conserved Turing-like mechanism in proximo-distal limb segmentation, and suggest that development has played a previously unrecognized role in the evolvability of limb proportions in a wide range of amniote taxa.

  17. The proportional odds cumulative incidence model for competing risks

    DEFF Research Database (Denmark)

    Eriksson, Frank; Li, Jianing; Scheike, Thomas

    2015-01-01

    We suggest an estimator for the proportional odds cumulative incidence model for competing risks data. The key advantage of this model is that the regression parameters have the simple and useful odds ratio interpretation. The model has been considered by many authors, but it is rarely used in pr...

  18. The relation between spatial thinking and proportional reasoning in preschoolers.

    Science.gov (United States)

    Möhring, Wenke; Newcombe, Nora S; Frick, Andrea

    2015-04-01

    Previous research has indicated a close link between spatial and mathematical thinking. However, what shared processes account for this link? In this study, we focused on the spatial skill of map reading and the mathematical skill of proportional reasoning and investigated whether scaling, or the ability to relate information in different-sized representations, is a shared process. Scaling was experimentally manipulated in both tasks. In the map task, 4- and 5-year-olds (N=50) were asked to point to the same position shown on a map in a larger referent space on a touch screen. The sizes of the maps were varied systematically, such that some trials required scaling and some did not (i.e., the map had the same size as the referent space). In the proportional reasoning task, children were presented with different relative amounts of juice and water and were asked to estimate each mixture on a rating scale. Again, some trials required scaling, but others could be solved by directly mapping the proportional components onto the rating scale. Children's absolute errors in locating targets in the map task were closely related to their performance in the proportional reasoning task even after controlling for age and verbal intelligence. Crucially, this was only true for trials that required scaling, whereas performance on nonscaled trials was not related. These results shed light on the mechanisms involved in the close connection between spatial and mathematical thinking early in life.

  19. Proportional control valves integrated in silicon nitride surface channel technology

    NARCIS (Netherlands)

    Groen, Maarten S.; Groenesteijn, Jarno; Meutstege, Esken; Brookhuis, Robert A.; Brouwer, Dannis M.; Lötters, Joost C.; Wiegerink, Remco J.

    2015-01-01

    We have designed and realized two types of proportional microcontrol valves in a silicon nitride surface channel technology process. This enables on-die integration of flow controllers with other surface channel devices, such as pressure sensors or thermal or Coriolis-based (mass) flow sensors, to o

  20. Map Scale, Proportion, and Google[TM] Earth

    Science.gov (United States)

    Roberge, Martin C.; Cooper, Linda L.

    2010-01-01

    Aerial imagery has a great capacity to engage and maintain student interest while providing a contextual setting to strengthen their ability to reason proportionally. Free, on-demand, high-resolution, large-scale aerial photography provides both a bird's eye view of the world and a new perspective on one's own community. This article presents an…